EEVblog Electronics Community Forum
Electronics => Projects, Designs, and Technical Stuff => Topic started by: Noopy on September 18, 2020, 09:38:12 pm
-
Hi all!
I need a topic for optoelectronic pictures. 8)
You can find the main page here:
https://richis-lab.de/Opto.htm (https://richis-lab.de/Opto.htm)
Today I have uploaded pictures of the 7 segment led display VQB17 built in the "Werk für Fernsehelektronik Berlin":
(https://richis-lab.de/images/led/01x01.jpg)
(https://richis-lab.de/images/led/01x04.jpg)
In a red cap there is a opaque foil above a white light shaper with a black textured surface.
(https://richis-lab.de/images/led/01x06.jpg)
You can see the LEDs through the light shaper.
...In the middle there is a loose bondwire...
(https://richis-lab.de/images/led/01x07.jpg)
To connect the pins to the board they used pressfit technology. Very cool! :-+
(https://richis-lab.de/images/led/01x09.jpg)
(https://richis-lab.de/images/led/01x10.jpg)
The die is 310µm x310µm.
You can spot a MESA structure and a dark square. I assume the dark square is some highly doped contact area.
(https://richis-lab.de/images/led/01x11.jpg)
(https://richis-lab.de/images/led/01x12.jpg)
(https://richis-lab.de/images/led/01x13.jpg)
You can´t really recognize which part of the structure is glowing because the light spreads through the semiconductor and the protective coat all over the die surface.
It start´s glowing at 5µA.
(https://richis-lab.de/images/led/01x17.jpg)
The LED glows also at -12V (2,5mA)... ;D
The light is much less uniform and of course a lot darker.
More pictures here:
https://richis-lab.de/Opto02.htm (https://richis-lab.de/Opto02.htm)
:-/O
-
Let´s look inside a blinking LED:
https://richis-lab.de/Opto03.htm (https://richis-lab.de/Opto03.htm)
(https://richis-lab.de/images/led/02x01.jpg)
You can´t burn the package stuff like epoxy mould. There is always some sticky dirt left. But you can take pictures through the package. The quality is a bit worse but it´s ok...
(https://richis-lab.de/images/led/02x02.jpg)
The "controller" is 0,48mm x 0,46mm the LED is 0,2mm x 0,19mm.
(https://richis-lab.de/images/led/02x04.jpg)
(https://richis-lab.de/images/led/02x06.jpg)
As expected there is a RC oscillator which frequency is divided with the help of 19 flip-flops.
And hey, the die has two outputs. It can be used to drive two LEDs alternating.
Since the outputs a current sources the not used output is connected to ground.
(https://richis-lab.de/images/led/02x07.jpg)
The current flowing into the LED shows that the second stage consumes nearly the same current as the first stage.
The blinking frequency is round about 1,2Hz.
(https://richis-lab.de/images/led/02x08.jpg)
You can see the oscillator frequency between the pins. The frequency is 0,59MHz. Devided by 19 you get 1,1Hz. That´s quite close to the 1,2Hz observed in the current flow. The frequency is not very stable.
:-/O
-
Thanks a lot.
What does Pre mean?
Presumably you don't need a series resistor for that particular LED? I always thought flashing LEDs still needed one.
Another thing which interests me is the maximum operating voltage is seldom mentioned on flashing LED datasheets. In another thread someone ran one off rectified 24VAC, so nearly 34V, via a suitable resistor, with no problems.
-
Looks nice.
Hey, what's your camera/optics/filters/polarization/lighting?
(I can't find any info on your website, auf Englisch oder Deutsch.)
-
I thought the old style blinking LEDs were fabricated as one chip.
-
If you immerse the plastic in an indexing matching liquid such as glycerin (index of refraction 1.47) or corn syrup (index of refraction 1.53), you can make the bulb "disappear." Then place a flat piece of glass like a watch glass or a microscope slide on top of the liquid and you should get a very good picture.
-
What does Pre mean?
Pre stands for Predriver.
Presumably you don't need a series resistor for that particular LED? I always thought flashing LEDs still needed one.
Another thing which interests me is the maximum operating voltage is seldom mentioned on flashing LED datasheets. In another thread someone ran one off rectified 24VAC, so nearly 34V, via a suitable resistor, with no problems.
I wasn´t sure first. This blinking LED also had no datasheet. On the package it says 5V and 20mA and with 5V it works consuming round about 20mA. :-+ ;D But of course it´s possible that there are a lot of blinking LEDs needing a resistor. I have to admit that was the first blinking LED I had on my table.
Looks nice.
Hey, what's your camera/optics/filters/polarization/lighting?
(I can't find any info on your website, auf Englisch oder Deutsch.)
Thanks! :)
I have a HowTo-page: https://www.richis-lab.de/Howto.htm (https://www.richis-lab.de/Howto.htm)
I have to update the pages but basically I still work with this equipment.
Here you can find some discussion regarding the HowTo: https://www.eevblog.com/forum/projects/decapping-and-chip-documentation-howto/msg2663778/#msg2663778 (https://www.eevblog.com/forum/projects/decapping-and-chip-documentation-howto/msg2663778/#msg2663778)
I thought the old style blinking LEDs were fabricated as one chip.
Perhaps I have to take some more pictures... :)
If you immerse the plastic in an indexing matching liquid such as glycerin (index of refraction 1.47) or corn syrup (index of refraction 1.53), you can make the bulb "disappear." Then place a flat piece of glass like a watch glass or a microscope slide on top of the liquid and you should get a very good picture.
Thans for the hint! :-+
-
Let´s look into a infrared camera module: Flir Lepton 2.5
(https://richis-lab.de/images/opticalsensor/01x01.jpg)
(https://richis-lab.de/images/opticalsensor/01x02.jpg)
(https://richis-lab.de/images/opticalsensor/01x07.jpg)
The Lepton 2.5 uses a shutter to calibrate the temperature measured with the microbolometer pixel.
(https://richis-lab.de/images/opticalsensor/01x06.jpg)
A temperature sensor on top of the module measures the temperature of the shutter (near the shutter ;)).
Yes, the module suffered some water damage. ;D
(https://richis-lab.de/images/opticalsensor/01x10.jpg)
On top of the sensor there are two lenses in a "screw". By screwing this optic in and out you can adjust the focus.
The lenses are probably built out of silicon.
(https://richis-lab.de/images/opticalsensor/01x11.jpg)
The housing uses a conductive coating. Here you can see the second lens in the "screw".
(https://richis-lab.de/images/opticalsensor/01x15.jpg)
The sensor module is quite big. Under the die in the middle there is a 0,6mm copper heatspreader. The heatspreader has to guarantee a uniform temperature over the die.
On top of the middle die there is an other die that forms a vacuum chamber. Gases would cool the sensor pixels.
(https://richis-lab.de/images/opticalsensor/01x18.jpg)
The top level die has a coating to reduce infrared reflection.
The lenses had also a coating.
(https://richis-lab.de/images/opticalsensor/01x21.jpg)
The top level die has a coating on the bottom to damp light outside the active area.
(https://richis-lab.de/images/opticalsensor/01x22.jpg)
Some damage... :'(
(https://richis-lab.de/images/opticalsensor/01x26.jpg)
Here you can see the sensor array with the first signal processing.
Under the big metal rectangles there are probably the dark reference pixels.
In the upper left corner you can see a small 4x3 array probably also some reference.
(https://richis-lab.de/images/opticalsensor/01x29.jpg)
One pixel is 17x17µm as Flir states in the datasheet. The diameter of one active area is round about 15µm.
(https://richis-lab.de/images/opticalsensor/01x30.jpg)
Well it´s kind of a MEMS. You can see the height of the pixels. The distance is important to thermaly isolate the pixel from the substrate.
(https://richis-lab.de/images/opticalsensor/01x31.jpg)
Even careful cleaning damages the pixel structures.
But here you can see the structures of the last two pixels seem to be corrupted. For a resolution of 80x60 the die uses 84x64 pixels. As seen with the DLP (https://richis-lab.de/DLP.htm (https://richis-lab.de/DLP.htm)) these MEMS-structures need dummy parts at the edge.
(https://richis-lab.de/images/opticalsensor/01x03.jpg)
(https://richis-lab.de/images/opticalsensor/01x32.jpg)
Can´t say much about the signal processing flip-chip. Damn underfiller. >:(
(https://richis-lab.de/images/opticalsensor/01x33.jpg)
I assume the small one is a voltage regulator.
More pictures here:
https://richis-lab.de/Opto04.htm (https://richis-lab.de/Opto04.htm)
:-/O
-
Thanks, these are very fascinating pictures.
-
Great pictures as always!
(https://richis-lab.de/images/led/01x04.jpg)
In a red cap there is a opaque foil above a white light shaper with a black textured surface.
Well, clearly it’s not opaque — “opaque” means “lichtundurchlässig”. (Same as “opak” in German.) It’d be accurate to call it a translucent film. (“Foil” in English refers exclusively to thin metal, not other materials. Those we call “films”.)
-
Wow, that IR sensors! :o
Very nice pics, thank you.
It looks like there is a small lens above each pixel, and some of the pixels lost their lens. How are those lens made? Are they grown on top of the circuit, or fabricated separately then glued on top later? :-//
-
Thank you all! :)
tooki you are right. I was wrong. "opaque" and "opak" are both wrong.
Also the hint regarding "foil" is interesting. Kind of a false friend.
Thank you! :-+
It looks like there is a small lens above each pixel, and some of the pixels lost their lens. How are those lens made? Are they grown on top of the circuit, or fabricated separately then glued on top later? :-//
That small parts are small plates which are mounted elevated over the substrate so they don´t loose thermal energy. You want to isolate these plates as good as possible to convert every infrared photon into a delta T.
At first most of the pixels looked good but while cleaning the die I damaged a lot of them.
The structures are fabricated like every MEMS. You stack special layers and etch one of the lower layers away.
I have written some words about that here: https://www.eevblog.com/forum/projects/dlp-die-pictures/msg2967068/#msg2967068 (https://www.eevblog.com/forum/projects/dlp-die-pictures/msg2967068/#msg2967068)
-
Thank you all! :)
tooki you are right. I was wrong. "opaque" and "opak" are both wrong.
Also the hint regarding "foil" is interesting. Kind of a false friend.
Thank you! :-+
Indeed! There are lots of false friends, from the classic “actual” vs. “aktuell”, “when” vs “wenn”, “eventually” vs. “eventuell”, to really subtle ones like the difference between the English word “manager” and the German word “Manager”* (which was obviously borrowed from English, but actually means something subtly different, but similar enough that people who aren’t truly bilingual won’t realize the other person means something else), and amusing ones like “body bag”, which means radically different things** in the two languages! 😂
*English “manager” means a person at any level of management, even way down at the bottom with just one layer of subordinates. In German, “Manager” specifically and exclusively refers to executive-level management. (English “manager” is “Leiter” in German, e.g. store manager is “Filialleiter”.)
**In German, a “body bag” is a one-strap backpack. In English, it’s the bag you use to hold a cadaver.
-
(“Foil” in English refers exclusively to thin metal, not other materials. Those we call “films”.)
Except that an overhead projector transparency is often called a "viewfoil" :-//
-
And every so often you see plastics referred to as foils, seems to sometimes show up with polyimide (particularly strong? shiny? golden?), maybe thicker pieces of mylar etc. Not sure why.
Tim
-
(“Foil” in English refers exclusively to thin metal, not other materials. Those we call “films”.)
Except that an overhead projector transparency is often called a "viewfoil" :-//
I never, ever heard them called that when I was in school.
-
And every so often you see plastics referred to as foils, seems to sometimes show up with polyimide (particularly strong? shiny? golden?), maybe thicker pieces of mylar etc. Not sure why.
Tim
Maybe association with the metalized versions of those plastic films.
-
More light! 8)
(https://www.richis-lab.de/images/led/03x01.jpg)
(https://www.richis-lab.de/images/led/03x02.jpg)
VQC10, a Dot-Matrix-Display with four 7x5 segments built by the Werk für Fernsehelektronik Berlin. Usually the VQC10 is potted but this one is a development part.
Interesting point: The VQC10 usually has a continuous pin row at the lower edge, here we see a big gap in the middle. The datasheet states the missing pins are used to transfer the heat out of the module. It seems like they got problems with the temperature while developing the VQC10...
(https://www.richis-lab.de/images/led/03x32.jpg)
There is a application note showing that the huge number of LEDs (140) drives the heat transfer to its limits. With a ambient temperature of 85°C you have to reduce the supply voltage to 2,5V or the pulse width to 1:25.
(https://www.richis-lab.de/images/led/03x05.jpg)
On the lower part of the board there are four 6-Flip-Flop-Dies controlling the columns.
(https://www.richis-lab.de/images/led/03x06.jpg)
It´s a development part. There is no connection to the FlipFlops but they connected the first three columns of all segments together and they connected the last two columns of all segments together.
The boreholes between the lines are interesting. I assume there have been connections so it was easier to test all LEDs in production. After testing you drill the holes and the VQC10 acts as it is designed to act.
(https://www.richis-lab.de/images/led/03x07.jpg)
(https://www.richis-lab.de/images/led/03x09.jpg)
The FlipFlop-Die has seen better days. It´s cracked in the upper right corner...
(https://www.richis-lab.de/images/led/03x33.jpg)
You can clearly see the output transistor with four resistors for adjusting the LED current.
(https://www.richis-lab.de/images/led/03x10.jpg)
A lot of the LED dies are not connected to the bondwire. Back in the days they had quite some problems with the bond quality.
(https://www.richis-lab.de/images/led/03x12.jpg)
(https://www.richis-lab.de/images/led/03x11.jpg)
The LEDs are 0,46mm x 0,46mm.
The datasheet states that GaAsP was used to built the LED.
In the VQB17 (https://www.richis-lab.de/Opto02.htm (https://www.richis-lab.de/Opto02.htm)) they used AlGaAs which is more efficient than GaAsP. I assume they didn´t use AlGaAs in the VQC10 because back in the days these LEDs were less robust. Perhaps that would have been a problem with the high temperatures in the VQC10.
(https://www.richis-lab.de/images/led/03x13.jpg)
With the right display you can see a small glimpse at 5µA.
(https://www.richis-lab.de/images/led/03x14.jpg)
For all others here you see 10µA.
(https://www.richis-lab.de/images/led/03x21.jpg)
2mA
(https://www.richis-lab.de/images/led/03x22.jpg)
Now that is interesting! 8)
GaAsP-LEDs are fabricated on a GaAs substrate. The lower dark area is the GaAs. The bright layer is the GaAsP. GaAs has a smaller bandgap than GaAsP and therefore can absorb the light generated in the upper layer quite efficient. Because of that the lower part is dark.
(https://www.richis-lab.de/images/led/03x31.jpg)
Breakdown occurs first at 22V! :o
Here you see 900µA. The light emission occurs only at the borders of the p-doped region. I assume that is because of the higher electrical field and the higher impurity density.
More pictures here:
https://www.richis-lab.de/Opto05.htm (https://www.richis-lab.de/Opto05.htm)
:-/O
-
A lot of the LED dies are not connected to the bondwire. Back in the days they had quite some problems with the bond quality.
I think that they just got bored bonding on this development device.
-
A lot of the LED dies are not connected to the bondwire. Back in the days they had quite some problems with the bond quality.
I think that they just got bored bonding on this development device.
You are right. In this device they stopped bonding but they had quite some problems with the quality of the bonds. :-+
-
(https://www.richis-lab.de/images/led/04x01.jpg)
Worldsemi WS2812B, an intelligent RGB-LED.
The potting is clear enough to take pictures through it.
(https://www.richis-lab.de/images/led/04x02.jpg)
The WS2812B has four contacts: Vdd, Vss, Data_In and Data-Out.
Interesting: The red LED is connected to Vdd by its substrate while the green and the blue LED needed a second bondwire to contact Vdd.
(https://www.richis-lab.de/images/led/04x03.jpg)
The red LED has an edge length of 0,17mm.
(https://www.richis-lab.de/images/led/04x04.jpg)
The edge length of the green and the blue LED is 0,20mm.
The structures look similar to a small signal transistor. There is a very small patterning on the surface.
(https://www.richis-lab.de/images/led/04x05.jpg)
(https://www.richis-lab.de/images/led/04x06.jpg)
The control die is 0,9mm x 0,7mm.
You can see the lines of the gatearray logic in the lower part of the die. The upper left area probably contains the housekeeping.
(https://www.richis-lab.de/images/led/04x07.jpg)
In the lower left corner there are the three "power stages".
I assume the structures on the left are some protection whatever. I don´t think they have put the power stages at the edge of the die.
The greenish squares are connected quite massive with the bondpads and Vss. It would be logical that these are the current sink transistors.
The following smaller structures... ...perhaps the current regulation circuits?
There is a fourth bonpad. A RGBW-controller? No, I don´t think so. The fourth structure looks different. The connection to the bondpad is smaller, the square looks different and the supposed current regulator is mirrored. In my opinion with this structure you can adjust the LED current.
(https://www.richis-lab.de/images/led/04x08.jpg)
There seems to be a fusible link in the upper left corner of the bondpad. That seems plausible. With the fuse connected you have the normal current, with the fuse cut you can adjust the current with an external resistor. Probably... :-/O
https://www.richis-lab.de/Opto06.htm (https://www.richis-lab.de/Opto06.htm)
:-/O
-
(https://www.richis-lab.de/images/eink/01x03.jpg)
(https://www.richis-lab.de/images/eink/01x01.jpg)
The ED060KC1 is a e-paper display used in the Kindle Paperwhite 3. It supplies you with a 16 greyscale 1072 x 1448 resolution.
I own a fragment of the display. The top glass is already removed. We see the lower glass with the TFT electronics and the active mass.
(https://www.richis-lab.de/images/eink/01x02.jpg)
If we turn the glass we see the undermost metalisation of the upper side.
(https://www.richis-lab.de/images/eink/01x04.jpg)
(https://www.richis-lab.de/images/eink/01x22.jpg)
Here is the controller. Some tracks come from the flex connector and a huge amount of signals travel to the display.
(https://www.richis-lab.de/images/eink/01x05.jpg)
Probably A060KEN01 is the panel name.
We see eight mask revisions.
(https://www.richis-lab.de/images/eink/01x23.jpg)
Is everything aligned properly?
(https://www.richis-lab.de/images/eink/01x07.jpg)
Probably that´s the contact connecting the upper glass that is just the upper electrode for the whole display.
(https://www.richis-lab.de/images/eink/01x08.jpg)
The active mass consists of bubbles with a diameter of up to 60µm containing pigments that travel through the bubble depending on the electrical field. Then the bubble is dark or bright.
(https://www.richis-lab.de/images/eink/01x09.jpg)
Under the thin layer of this active mass we have the TFT circuit.
(https://www.richis-lab.de/images/eink/01x10.jpg)
Datasheet says the dot pitch is 84µm.
The bright area is the upper electrode controlling the electrical field around the active mass.
On the upper electrode we see the contours of a capacitor (the bigger area) and the pixel switch (the smaller square).
You need a capacitor because the pigments in the bubbles are quite slow but you want to switch the pixel fast.
Around the pixel there are supply and control lines. There are two horizontal lines. One line is the reference for the capacitor in the pixel, one is the activation line for the whole row.
There are three vertical lines. One line is controlling the gates of the transistors of the pixel column. The other two lines seem to be connected to every horizontal line. That can´t be true because then it would be impossible to address one single line. It seems like the controller is selecting the pixel rows by these additional vertical lines. In pictures of the complete display you can´t spot a controller on the sides of the panel.
(https://www.richis-lab.de/images/eink/01x11.jpg)
From the bottom of the glass we can take a look at the undermost metal layer. We clearly see the two gate electrodes of every pixel. You need two electrodes because TFT transistors have a high leakage current. With the high voltage (something around +/-10-20V) the current flow would degrade the pixel status.
(https://www.richis-lab.de/images/eink/01x12.jpg)
On the left side of the panel the capacitor reference is connected directly to one big metal line. The row selection line is connected to two transistors probably acting as a pull-up or pull-down.
(https://www.richis-lab.de/images/eink/01x13.jpg)
(https://www.richis-lab.de/images/eink/01x14.jpg)
On the lower part of the panel there are three big lines acting as pull-up or pull-down for the control lines.
Not every line is connected. That is plausible because for 1072 x 1448 dots you need 1,35 row control lines for every column control line.
(https://www.richis-lab.de/images/eink/01x28.jpg)
(https://www.richis-lab.de/images/eink/01x24.jpg)
There seems to be a lack of metal on the lowest pixel row. In one place there is a huge amount of metal. Probably the lowest line is a dummy line like we have seen that in the DLP-Modul DMD1076 (https://www.richis-lab.de/DLP.htm (https://www.richis-lab.de/DLP.htm)) and in the Lepton 2.5 (https://www.richis-lab.de/Opto04.htm (https://www.richis-lab.de/Opto04.htm)).
(https://www.richis-lab.de/images/eink/01x15.jpg)
Fortunately here we can see the two transistors.
(https://www.richis-lab.de/images/eink/01x25.jpg)
(https://www.richis-lab.de/images/eink/01x26.jpg)
A test structure! With the bottom pad you can switch the pixel. The left pad supplies the pixel. The upper pad is the reference for the capacitor and the right pad is connected to the upper electrode.
(https://www.richis-lab.de/images/eink/01x19.jpg)
(https://www.richis-lab.de/images/eink/01x06.jpg)
(https://www.richis-lab.de/images/eink/01x18.jpg)
On the edge of the panel we have some nice test structures showing the construction of the panel.
Here we see M1 and M2 showing us the metal parts of the MOSFETs.
TH probably stands for through hole and gives you 10µm vias. It seems that is a little too much.
I don´t know what BP means.
(https://www.richis-lab.de/images/eink/01x21.jpg)
(https://www.richis-lab.de/images/eink/01x20.jpg)
Here we have AS. That probably stands for amorphous silicon that is located in the MOSFET area.
Vias are smaller here. Looks good now.
It seems M2_10µm stands for a different transistor type. The contacts between the MOSFETs are smaller in this area.
(https://www.richis-lab.de/images/eink/01x17.jpg)
(https://www.richis-lab.de/images/eink/01x16.jpg)
Here we see the uppermost metal layer M3. There is a lower part which increases the capacitance of the capacitor underneath. The capacitance is located between M2 and M1/M3.
The amorphous silicon looks reddish here.
Where the control lines cross each other there are blue dots. Perhaps these dots control whether or not the control lines have contact to each other. :-//
https://www.richis-lab.de/eink01.htm (https://www.richis-lab.de/eink01.htm)
:-/O
-
Looking at all those parallel traces on glass, I wonder if they can be used as a diffraction grate for a laser pointer, to project interference patterns on a wall. ;D
-
Looking at all those parallel traces on glass, I wonder if they can be used as a diffraction grate for a laser pointer, to project interference patterns on a wall. ;D
That would definitely look interesting! ;D
(https://www.richis-lab.de/images/eink/01x17.jpg)
(https://www.richis-lab.de/images/eink/01x16.jpg)
A small update: ITO stands for Indium Tin Oxide and that makes perfectly sense. It seems like there is a layer of ITO all over the area with slots on top of the electrodes. With this shielding the control lines don´t influence the pigment bubbles. :-+
-
VQC10...
https://www.richis-lab.de/Opto05.htm (https://www.richis-lab.de/Opto05.htm)
(https://www.richis-lab.de/images/led/05x01.jpg)
I have a second VQC10 (4x 7x5-Dot-Matrix-Display built by the Werk für Fernsehelektronik Berlin).
It seems like this display is a development part like the first VQC10.
(https://www.richis-lab.de/images/led/05x02.jpg)
This part is already potted and has some more pins to get rid of the power loss.
(https://www.richis-lab.de/images/led/05x03.jpg)
The layout is similar to the first part but here we have four additional wide copper traces conducting heat from the LEDs to the pins at the bottom.
(https://www.richis-lab.de/images/led/05x06.jpg)
WF had problems with the bonding. The magazine Radio Fernsehen Elektronik 2/89 describes that in production they had up to two rework loops to get good parts.
In this VQC10 only the third segment is really bad.
(https://www.richis-lab.de/images/led/05x04.jpg)
(https://www.richis-lab.de/images/led/05x05.jpg)
That doesn´t look good... :o
(https://www.richis-lab.de/images/led/05x07.jpg)
The Flip-Flop dies are newer:
01K710 => 03K710
A1/B1/C1/D1/F1/H1/I1/M1 => A7/B2/C7/D2/F2/H7/I7/M7
(https://www.richis-lab.de/images/led/05x11.jpg)
Here we have no option to adjust the current limitation resistor of the output stages.
(https://www.richis-lab.de/images/led/05x08.jpg)
(https://www.richis-lab.de/images/led/05x09.jpg)
(https://www.richis-lab.de/images/led/05x10.jpg)
They changed the LED type. The die is smaller (0,38mm). The active area also occupies a smaller fraction of the die. But the bondpad and bondwire interfere less with the light.
(https://www.richis-lab.de/images/led/05x12a.jpg)
5µA :-+
(https://www.richis-lab.de/images/led/05x12b.jpg)
10µA
(https://www.richis-lab.de/images/led/05x12c.jpg)
20µA
(https://www.richis-lab.de/images/led/05x13.jpg)
5mA
You can clearly see the two layer construction.
(https://www.richis-lab.de/images/led/05x14.jpg)
20mA 8)
https://www.richis-lab.de/Opto07.htm (https://www.richis-lab.de/Opto07.htm)
:-/O
-
(https://www.richis-lab.de/images/opticalsensor/02x01.jpg)
L133C, a 1x1024 CCD sensor built by "Werk für Fernsehelektronik Berlin".
It´s quite similar to the Fairchild CCD113.
(https://www.richis-lab.de/images/opticalsensor/02x02.jpg)
The package consists of two parts that are glued together.
(https://www.richis-lab.de/images/opticalsensor/02x03.gif)
The datasheet explains the construction of the L133C.
It consists of one optical line and two CCD lines that hold and transport the generated charges.
Around the CCD lines there are two lines that reduce noise. The upper one generates a end of line signal.
(https://www.richis-lab.de/images/opticalsensor/02x04.jpg)
The die is 14,5mm x 1,5mm. The whole circuit is protected with a metal layer so the light doesn´t interfere with it.
(https://www.richis-lab.de/images/opticalsensor/02x05.jpg)
This bondwire connects the frame with the upper metal layer. The frame is connected to the negative supply. It seems like they wanted to have an option to connect the metal layer to a different potential.
It seems there was a first failed bond event.
(https://www.richis-lab.de/images/opticalsensor/02x06.jpg)
(https://www.richis-lab.de/images/opticalsensor/02x07.jpg)
(https://www.richis-lab.de/images/opticalsensor/02x08.jpg)
There are three areas with mask revision but one is different than the other two. :-//
(https://www.richis-lab.de/images/opticalsensor/02x09.jpg)
Some structures to adjust the masks and monitor the process quality.
(https://www.richis-lab.de/images/opticalsensor/02x10.jpg)
I/O protection
(https://www.richis-lab.de/images/opticalsensor/02x14.jpg)
Input stage
(https://www.richis-lab.de/images/opticalsensor/02x15.jpg)
(https://www.richis-lab.de/images/opticalsensor/02x16.jpg)
The CCD lines operate with only one clock (Vgt). Instead of a second clock it uses a mid-level voltage (Vt).
You can spot the transfergate (red) and the four CCD lines (green and blue). The CCD line for the optical data is wider so it is able to store more electrons.
Over each CCD line there are overlapping gate electrodes which makes the structure confusing.
Ve is the input potential of the CCD lines.
There is a covered photogate area that gives the user a dark reference (purple). The dark reference is isolated from the rest of the photogate by four pixel (white). It seems at the beginning of the line there are four more isolation cells (pink).
The circuit gives you a withe reference at the end of the data stream. I´m not sure how that happens.
(https://www.richis-lab.de/images/opticalsensor/02x24.jpg)
This structure modifies the photogate potential nb with respect to the clocks Vgt and Vt. Probably it supports the charge transfer from the photogate to the CCD lines.
(https://www.richis-lab.de/images/opticalsensor/02x21.jpg)
The output stage.
Interesting: SHoutA, VshA, SHoutB and VshB are not connected on the die. :o
(https://www.richis-lab.de/images/opticalsensor/02x22.jpg)
(https://www.richis-lab.de/images/opticalsensor/02x23.jpg)
At the end of the photogate there are four more isolation pixel and four more black reference pixel. It seems like there are 1,5 Pixel covered with metal that normally should not be covered. :-/O
At the end of the CCD lines there are three output stages. The first part in such a stage is a reset transistor that conducts the charge to the positive supply before the next charge is delivered. The second part is a capacitor holding the charge. The third part is the output transistor of the CCD line. This output controls a bigger push-pull-stage driving the output of the L133C.
The uppermost CCD line is equipped with a similar output stage. The charges from the lower CCD line are conducted to the supply directly.
(https://www.richis-lab.de/images/opticalsensor/02x26.jpg)
(https://www.richis-lab.de/images/opticalsensor/02x29.jpg)
(https://www.richis-lab.de/images/opticalsensor/02x30.jpg)
At the upper edge there is a circuit using the transport clock and generating the clocks necessary to control the output stage.
It seems like the bigger circuits are modifying the duty cycle and the smaller parts are adding some delay.
Some more pictures here:
https://www.richis-lab.de/Opto08.htm (https://www.richis-lab.de/Opto08.htm)
:-/O
-
Nice images and circuit/image analysis!!
Way back in the very early 80s we developed our own CCDs for a different use. Back then CCDs were mostly for imaging and some were used as delays, like the audio "reverb" use. Vaguely remember Tektronix using a very fast CCD in a scope to "capture" a high speed "event" then play it back at a slower speed for the ADC to digitize, high speed and resolution ADCs weren't available then.
Our use was different, the CCDs were used as complex R + jX convolvers in the Chirp Z Transform (and other proprietary DTCA transforms). The CZT was another method of Fourier Transforms, and the basis of our Real Time Spectrum Analyzer. CCDs are very tricky to get working properly, however when working they are remarkable devices.
Keep these nice old chip images coming, they are really fun to view and discuss, and bring back memories :-+
Best,
-
Nice images and circuit/image analysis!!
[...]
Keep these nice old chip images coming, they are really fun to view and discuss, and bring back memories :-+
Thanks I still have some really interesting parts in stock. :)
Way back in the very early 80s we developed our own CCDs for a different use. Back then CCDs were mostly for imaging and some were used as delays, like the audio "reverb" use. Vaguely remember Tektronix using a very fast CCD in a scope to "capture" a high speed "event" then play it back at a slower speed for the ADC to digitize, high speed and resolution ADCs weren't available then.
Our use was different, the CCDs were used as complex R + jX convolvers in the Chirp Z Transform (and other proprietary DTCA transforms). The CZT was another method of Fourier Transforms, and the basis of our Real Time Spectrum Analyzer. CCDs are very tricky to get working properly, however when working they are remarkable devices.
I have done quite some (private) research on CCDs. I'm a big fan of the Gould 4074 oscilloscope. 1987 it was the fastest available real time sampling oscilloscope with 400MS/s (8Bit). The HP 54111D was able to do 1GS/s but just with reduced resolution (6Bit). 250MS/s with 8Bit.
The Gould 4074 uses a Plessey MS1007A CCD for each channel. It has eight lines each containing 128 points and working with 50MHz.
Gould integrated quite some magic to get the CCDs and the oscilloscope working as good as possible at 400MS/s. And they used mostly "normal" parts not much unobtanium.
I have heard CCDs were also used for signal processing in radar systems.
-
I have done quite some (private) research on CCDs. I'm a big fan of the Gould 4074 oscilloscope. 1987 it was the fastest available real time sampling oscilloscope with 400MS/s (8Bit). The HP 54111D was able to do 1GS/s but just with reduced resolution (6Bit). 250MS/s with 8Bit.
The Gould 4074 uses a Plessey MS1007A CCD for each channel. It has eight lines each containing 128 points and working with 50MHz.
Gould integrated quite some magic to get the CCDs and the oscilloscope working as good as possible at 400MS/s. And they used mostly "normal" parts not much unobtanium.
I was not aware of the Gould Scopes, thanks for the info :-+
I have heard CCDs were also used for signal processing in radar systems.
Yes, and anti-radar "stealth" applications ::)
Many additional signal processing applications as well.
Best,
-
Up to now I have 16 of the Gould 40xx oscilloscopes in different shapes. ;D
https://www.richis-lab.de/Gould407X.htm (https://www.richis-lab.de/Gould407X.htm)
Sometimes I hopefully will post my complete extreme teardown report. It has round about 400 pages but the proof reading takes soooo long only the first 60 pages are online... ...and it will be available in german only... ...but with a lot of pictures. ::)
-
That's a pretty device.
I guess that they didn't like knobs that much!
Unrelated: Here's my half-baked re-write of Hantek software.
The ranges (voltage, timebase & everything else) can be operated with the mouse scroll.
-
The only real drawback is the old CRT (3kV). The figures aren´t really sharp. :-[
Unrelated: Here's my half-baked re-write of Hantek software.
The ranges (voltage, timebase & everything else) can be operated with the mouse scroll.
A nice update! :-+
-
(https://www.richis-lab.de/images/opticalsensor/03x01.jpg)
L211C, a 190x244 CCD sensor built by the Werk für Fernsehelektronik. It is similar to the Fairchild CCD211 but there are some differences.
M1 stand for January 1980.
(https://www.richis-lab.de/images/opticalsensor/03x16.jpg)
There are quite some testpins! :o
(https://www.richis-lab.de/images/opticalsensor/03x02.jpg)
(https://www.richis-lab.de/images/opticalsensor/03x03.jpg)
(https://www.richis-lab.de/images/opticalsensor/03x04.jpg)
The package consists of two plastic parts that are put together with some chewy glue.
(https://www.richis-lab.de/images/opticalsensor/03x06.jpg)
The die is placed in a shallow pit.
Interesting: The GND pin is connected to the gold plating on the bottom of the pit not to the die itself. (The die is connected to the plating on the left.) I assume that´s better because in the die the light generates free charges. The negative charges are used to get a signal the positive charges probably go through the substrate. If you would connect the die to GND on a single point there would be an uneven current flow and the potential of the substrate wouldn´t be uniform distorting the charge accumulation and in the end giving you bad pictures.
(https://www.richis-lab.de/images/opticalsensor/03x07.jpg)
There are scratches telling you where to place the die. :-+ ;D
(https://www.richis-lab.de/images/opticalsensor/03x08.jpg)
edge length 6,3mm
(https://www.richis-lab.de/images/opticalsensor/03x10.jpg)
(https://www.richis-lab.de/images/opticalsensor/03x13.jpg)
Well that´s not a perfect die. These two lines probably give you corrupted information.
(https://www.richis-lab.de/images/opticalsensor/03x31.jpg)
I don´t know what the C in L211C tells us but the Fairchild CCD211 was binned and the CCD211C was the worst one. It was possible to get a part with up to three defect adjacent columns.
(https://www.richis-lab.de/images/opticalsensor/03x11.jpg)
Eight masks...
(https://www.richis-lab.de/images/opticalsensor/03x05.jpg)
(Picture from Fairchild CCD The Solid State Imaging Technology 1981)
The L211C works similar to the CCD211 for which we have a block diagram. There are photosensitive pixel in which charges are generated. All the charges are transferred to vertical CCDs which transports them to a horizontal CCD which transports them to the output.
This construction is called Frame Interline Transfer CCD and it takes the whole picture in one step.
Under the horizontal CCD there is a anti blooming gate. If you put too much light on one pixel there are too much charges for the one slot and the charges travel to the surrounding pixel (vertical). The same problem occurs in the horizontal CCD. In the first place that gives you bright lines where the overwhelmed pixel is. Later on it generates bright bars in the horizontal CCD. In the CCD211 (and the L221C) there is a horizontal anti blooming gate. It is a path for these charges so they don´t interfere with the other columns. There is still vertical blooming but no horizontal blooming.
At the output there is a floating gate reading the charges in the horizontal CCD and controlling the output stage.
(https://www.richis-lab.de/images/opticalsensor/03x15.jpg)
(https://www.richis-lab.de/images/opticalsensor/03x17.jpg)
(https://www.richis-lab.de/images/opticalsensor/03x18.jpg)
Surprise! At the bottom of the die there is an additional CCD-line probably for testing.
On the left side you see the connection and distribution of the clock lines for the vertical CCDs.
In the matrix you see the elements in which light generates charges. On the right side of every pixel row there are the vertical CCDs.
(https://www.richis-lab.de/images/opticalsensor/03x19.jpg)
The edge length of the active area seems to be something around 15x15µm. I don´t know what the short red lines are. :-// Well there are a lot of structures one above the other...
(https://www.richis-lab.de/images/opticalsensor/03x20.jpg)
(https://www.richis-lab.de/images/opticalsensor/03x22.jpg)
In the upper part of the die there is the horizontal CCD. On the left side of the horizontal CCD there are some buckets covered with metal to give the user a dark reference.
Between the sensor matrix and the horizontal CCD you can spot the anti blooming gate.
(https://www.richis-lab.de/images/opticalsensor/03x23.jpg)
(https://www.richis-lab.de/images/opticalsensor/03x24.jpg)
On the right side of the die the horizontal CCD makes a 180° turn. The first floating gate controls the output stage but the CCD travels further to the left where you can see some more floating gates...
(https://www.richis-lab.de/images/opticalsensor/03x25.jpg)
The output stage is quite simple.
(https://www.richis-lab.de/images/opticalsensor/03x26.jpg)
(https://www.richis-lab.de/images/opticalsensor/03x27.jpg)
There is a big circuit that is connected to the additional floating gates. From outside it is just connected with testpins.
It seems to be a wider CCD that splits into two CCDs at the left end. On the left side there are two output stages which are connected to the two CCDs. One of the CCDs is shorter than the other. It seems like a output stage as we have seen it in the BBDs (https://www.richis-lab.de/bbd01.htm (https://www.richis-lab.de/bbd01.htm)) where just every second bucket contained information. Using the BBDs you have to connect the two outputs.
(https://www.richis-lab.de/images/opticalsensor/03x30.jpg)
(Patent US3806772A)
The wide CCD (and the folded horizontal CCD) seems to be a so called Charge Coupled Amplifier a circuit like a distributed amplifier. You can probably use the amplifier to take pictures in low light.
The datasheet of the Fairchild CCD211 shows a square called "amplifier circuit" but beside that hint you don´t find anything about an additional amplifier in the CCD211 and L211C documents. Perhaps the amplifier was not implemented for the "normal" user?
https://www.richis-lab.de/Opto09.htm (https://www.richis-lab.de/Opto09.htm)
:-/O
-
(https://www.richis-lab.de/images/led/06x01.jpg)
(https://www.richis-lab.de/images/led/06x02.jpg)
DLSF1414, a strange 4* 16 segment display built by Siemens. You can´t find any information regarding the DLSF1414. There was just a DL1414 but Siemens did customer specific displays too. Perhaps the DLSF1414 is such a customer specific display.
(https://www.richis-lab.de/images/led/06x05.jpg)
The DL1414 contains a RAM which is adressed with two adress bits and a write input. Through a 7Bit interface you put the code of the character you want to see into one of the four slots of the RAM.
There is an oscillator that activates one digit after the other. While activating a digit the circuit activates one of the slots in the RAM. The RAM outputs the saved code to the ROM and the ROM outputs 17Bits that activates the segments that show the character we wanted to see.
(https://www.richis-lab.de/images/led/06x04.jpg)
(https://www.richis-lab.de/images/led/06x23.jpg)
There are other displays that provide you with more functions. Perhaps the DLSF1414 is a DL1414 with some of these functions added.
(https://www.richis-lab.de/images/led/06x06.jpg)
In the DLSF1414 there is a board potted in clear potting.
(https://www.richis-lab.de/images/led/06x07.jpg)
On the backside we see the control circuit that is potted with some dark potting. There seems to be a second circuit in the upper left corner. Perhaps that´s a small logic circuit and that is the difference between the DL1414 and the DLSF1414. (This circuit is lost. :-[)
(https://www.richis-lab.de/images/led/06x08.jpg)
9041, probably the datecode.
(https://www.richis-lab.de/images/led/06x09.jpg)
The digits are dies with the dimensions 2,1mm x 1,8mm. There are 16 segments and a dot.
Since there is a dot at the upper edge and at the lower edge you can bond the die rotated 180°.
Thin metal lines distribute the current over the light emitting segments. The substrate is the common anode.
(https://www.richis-lab.de/images/led/06x10.jpg)
The control circuit is 3,1mm x 2,7mm.
(https://www.richis-lab.de/images/led/06x11.jpg)
(https://www.richis-lab.de/images/led/06x12.jpg)
(https://www.richis-lab.de/images/led/06x13.jpg)
Siemens designed the control circuit in 1988. SMC4621 probably is a internal naming.
TONY? BE? ;D
(https://www.richis-lab.de/images/led/06x14.jpg)
We can find five mask revisions: 1C, 2C, 4D, 7C, 8C
(https://www.richis-lab.de/images/led/06x24.jpg)
Some areas are easy to spot. At the upper edge there are 17 driver for 16 segments and a dot (red). At the lower edge there are four driver for the four digits (green).
At the left edge we can find the data interface (blue). There are seven bondpads side by side but D0 is placed at the bottom of the die. There are buffer stages as shown in the block diagram.
The data interface is connected to a 4x7 RAM (yellow). The control lines for the four columns of the RAM are connected to the digit drivers (green). You activate one column and the digit drivers activate the right digit (over a small logic).
The output of the RAM is the input for the ROM with a quite complex signal conditioning (orange). The size of the ROM is best explained with 17x17x2x3. The output of the ROM is connected to the segment drivers.
In the middle of the die we can spot an oscillator with a big capacitor (pink). The clock is fed to a bondpad and from there to something like a clock divider and distribution. It seems like the control circuit can be used for other displays with more functionality. As seen in the block diagrams there are displays with a clock input/output. One bondpad is directly connected to the segment drivers. Perhaps that one was used for dimming the display. There are some more used and unused bondpads eleven of them are equipped with buffer stages as the data interface.
(https://www.richis-lab.de/images/led/06x15.jpg)
Here we see a segment driver. There is a big transistor right of the bondpad and a control circuit right of the transistor. There has to be some current limiting.
(https://www.richis-lab.de/images/led/06x16.jpg)
The power transistor for the small dot is smaller than for the other segments as it has to sink less current for the same brightness.
(https://www.richis-lab.de/images/led/06x18.jpg)
The digit drivers are bigger but less complex.
(https://www.richis-lab.de/images/led/06x17.jpg)
Above and below the input bondpads there are protection circuits.
(https://www.richis-lab.de/images/led/06x19.jpg)
Here we have the 4x7 RAM. Left the input, right the output.
(https://www.richis-lab.de/images/led/06x22.jpg)
(https://www.richis-lab.de/images/led/06x20.jpg)
The ROM has to contain 63 characters. So you need a 17x63 ROM. But that ROM looks quite strange...
(https://www.richis-lab.de/images/led/06x21.jpg)
From left and right there are 8 and 9 control lines (yellow/red). But that would give us just a 17x17 ROM, not enough for the character set.
On the upper edge you can spot three transistors. One transistor (ON) allows us to switch every segment on, probably for a cursor functionality. Two transistors (OUT1/OUT2) switch the segment driver to one of two vertical lines (green). That expands the memory to 17x17x2 or 17x34, still not enough.
There are three more control lines below the memory array (blue). These control lines switch three transistors (C1/C2/C3) that activate three vertical lines around the two green output lines. That expands the memory to 17x17x3 (17x51), still not enough in the first place. There has to be 12 characters which are generated by adding two other characters, i.e. by activating more than two vertical lines.
https://www.richis-lab.de/Opto10.htm (https://www.richis-lab.de/Opto10.htm)
:-/O
-
(https://www.richis-lab.de/images/led/07x01.jpg)
(https://www.richis-lab.de/images/led/07x02.jpg)
The VQB76 is a 7 segment display built by the Werk für Fernsehelektronik. The segments are formed with long LEDs. There was also a variant with a red glass for better contrast (VQB76-1).
(https://www.richis-lab.de/images/led/07x03.jpg)
(https://www.richis-lab.de/images/led/07x04.jpg)
The package is a metal tray with a glass element glued onto it. In the metal tray there is a ceramic plate carrying the circuit.
(https://www.richis-lab.de/images/led/07x18.jpg)
Each segment is built with two LEDs connected in series. You must pay attention that the dot consists of just one LED and so you need a different resistor for this one.
Another important point: There are three independent anode pins.
(https://www.richis-lab.de/images/led/07x06.jpg)
The LEDs are 1,2mm x 0,3mm. They are split in three segments. Here the segment in the middle of the die isn´t formed accurate.
The thin metal line distributes the current over the segments.
The element in the upper right corner is probably for checking the mask alignment.
(https://www.richis-lab.de/images/led/07x05.jpg)
The left LED is damaged. The splintered part is stuck in the solder at the bottom of the die.
(https://www.richis-lab.de/images/led/07x07.jpg)
The dot LED doesn´t look very good.
(https://www.richis-lab.de/images/led/07x08.jpg)
(https://www.richis-lab.de/images/led/07x09.jpg)
It´s Christmas time! Let´s turn on some light. 8)
At 20mA the forward voltage is 3,24V (2x 1,62V).
You can see the incomplete segment in the middle of the die.
The upper epitaxial layer (GaAsP) is translucent while the lower substrate (GaAs) blocks the light.
(https://www.richis-lab.de/images/led/07x11.jpg)
(https://www.richis-lab.de/images/led/07x12.jpg)
At 20mA (1,67V) you can see the higher current density around the metal contact. In this area the light is a little brighter.
(https://www.richis-lab.de/images/led/07x13.jpg)
Let´s drive the LED into reverse breakdown. At 52V (26V for one LED) the current is 0,1mA and you can see the first red dots.
(https://www.richis-lab.de/images/led/07x14.jpg)
1,2mA, more small lights.
(https://www.richis-lab.de/images/led/07x15.jpg)
5mA
(https://www.richis-lab.de/images/led/07x16.jpg)
10mA
(https://www.richis-lab.de/images/led/07x17.jpg)
Switching from 10mA to 20mA there are more light dots but some areas got darker.
I assume the light intensity dropped with the higher temperature of the die. At 10mA the power dissipation is 0,29W. At 20mA the power dissipation is 0,62W.
(https://www.richis-lab.de/images/led/08x01.jpg)
(https://www.richis-lab.de/images/led/08x02.jpg)
I have another VQB76 without a marking.
The layout on the ceramic plate is a little different and in the bond areas there is no gold plating.
(https://www.richis-lab.de/images/led/08x03.jpg)
The big LEDs are the same but the metal layer is a little thicker.
(https://www.richis-lab.de/images/led/08x04.jpg)
For the dot they used a different type of LED. We know this one from the VQC10: https://www.richis-lab.de/Opto05.htm (https://www.richis-lab.de/Opto05.htm)
https://www.richis-lab.de/Opto11.htm (https://www.richis-lab.de/Opto11.htm)
:-/O
-
(https://www.richis-lab.de/images/opto/02x02.jpg)
(https://www.richis-lab.de/images/opto/02x01.jpg)
(https://www.richis-lab.de/images/opto/02x09.jpg)
(https://www.richis-lab.de/images/opto/02x08.jpg)
SP107 is a photodiode built by the Werk für Fernsehelektronik. Combined with the IR emitting diode VQ170 you can built an optical transmission line <1km.
Besides the printed name the green dot marks the SP107. A red dot would show that it is a VQ170.
(https://www.richis-lab.de/images/opto/02x03.jpg)
There is a plastic protection cap for the SP107.
(https://www.richis-lab.de/images/opto/02x04.jpg)
We can already see the photodiode.
(https://www.richis-lab.de/images/opto/02x05.jpg)
(https://www.richis-lab.de/images/opto/02x06.jpg)
The photodiode is placed on a quite big heatspreader. It is protected with some transparent potting. Dirt on this potting obscures the pictures a little.
(https://www.richis-lab.de/images/opto/02x07.jpg)
The edge length of the photodiode is 1mm. It´s a PIN-diode. In the lower right corner there is an alternative bondpad.
https://www.richis-lab.de/Opto12.htm (https://www.richis-lab.de/Opto12.htm)
:-/O
-
(https://richis-lab.de/images/opticalsensor/01x11.jpg)
The housing uses a conductive coating. Here you can see the second lens in the "screw".
Just in case someone is interested in. The technology used is called MID (Molded Interconnect Device). By the looks of it it uses the LPKF-LDS process, which means the non-conductive plastic is injection molded and contains additives that are activated using 3D laser structuring, you can tell by the vertical structure. Afterwards a wet chemical process is used to plate copper on the activated areas, with a final finish of nickel and gold. See also LPKF-LDS (https://www.hahn-schickard.de/forschung-entwicklung/raeumliche-elektronik-mid/lpkf-lds-mid) or 3D-MIDs (https://www.lpkf.com/de/branchen-technologien/elektronikfertigung/laser-direkt-strukturierung-lds-von-3d-mids)
-branadic-
-
I have and update to the L211C CCD sensor.
There is a paper "Konzeption Fertigungseinführung L220C" describing the manufacturing of the bigger L220C in detail. It´s highly probably that the L211C is constructed very similar. Here you see some pictures showing the construction of the CCD sensor. I have added some color.
(https://www.richis-lab.de/images/opticalsensor/03x32.jpg)
The first steps is to integrate a n-doped shift register channel and the highly p-doped channel stopper into the p-doped substrate.
(https://www.richis-lab.de/images/opticalsensor/03x33.jpg)
(https://www.richis-lab.de/images/opticalsensor/03x34.jpg)
Two polysilicon layers represent the electrodes for the CCD shift register. The two supply lines run above each other to the side of the matrix so they don´t shadow the active area too much.
(https://www.richis-lab.de/images/opticalsensor/03x35.jpg)
There is no pictures showing the metal layer so I had to add it. ;) The metal lines on top of the shift register act as a photogate and protect the shift register against light.
(https://www.richis-lab.de/images/opticalsensor/03x19.jpg)
The dark squares are probably the active areas. The short red looking lines could come from the fact that the surface is quite uneven.
https://www.richis-lab.de/Opto09.htm#L220 (https://www.richis-lab.de/Opto09.htm#L220)
:-/O
-
Thing of beauty... Costs like my house...
Came to my hands for 2 days, Gsense 6060 CMOS sensor
Bright field illumination, Nikon 5x BD plan and Nikon 20x ELWD
-
On last picture many test pins looks as being used for testing the chip.
-
Thing of beauty... Costs like my house...
Came to my hands for 2 days, Gsense 6060 CMOS sensor
Bright field illumination, Nikon 5x BD plan and Nikon 20x ELWD
Good stuff :-+
I suppose those blue balls are the microlenses array? How are they even fabricating this stuff :scared:
-
(https://www.richis-lab.de/images/opticalsensor/04x01.jpg)
(https://www.richis-lab.de/images/opticalsensor/04x02.jpg)
The IL-C6 is a CCD image sensor consisting of a single line with 2048 pixels. The device is manufactured by the Canadian company DALSA, which now belongs to Teledyne.
The CCD image sensor is in a special DIL package with dimensions of 42,4mm x 7,5mm. The datasheet highlights the high readout speed, which can be up to 15MHz. The dynamic range is 1:6000.
(https://www.richis-lab.de/images/opticalsensor/04x03.jpg)
Viewed from the side the glass lid on the ceramic case is clearly visible.
(https://www.richis-lab.de/images/opticalsensor/04x05.jpg)
The VBB potential (Substrate Bias Voltage) is fed to the sensor via four pins. Three of the four potentials are connected to the housing with low impedance by two bondwires each. The signal information is located as charge packets in the sensor areas and in the CCD line. These charges are processed and moved by electric fields. Local potential fluctuations in the substrate could accordingly have a negative effect on signal recording and signal transmission. For this reason it is important to keep the substrate potential low impedance at a fixed potential.
(https://www.richis-lab.de/images/opticalsensor/04x04.jpg)
(https://www.richis-lab.de/images/opticalsensor/04x06.jpg)
The black sensor area is clearly visible on the die. The datasheet shows the basic operation of the CCD image sensor. It is 2048 pixels with a width of 13µm and a height of 500µm. At the beginning and at the end of each line two darkened pixels are integrated, which can be used as reference value. Two further pixels each represent a buffer to the active area.
Via the potential PR the sensor areas can be reseted to the potential VPR. After exposure TCK ensures that the charges generated in proportion to the light incidence are transferred to the CCD shift register. The four phase-shifted clock signals CR1, CR2, CR3, and CR4 generate an electric field with potential wells that move from left to right, shifting the charge packets toward the output. This is described in more detail in the L133C (https://www.richis-lab.de/Opto08.htm (https://www.richis-lab.de/Opto08.htm)).
On the far right is a two-stage amplifier circuit that serves the output OS. The electrode VSET causes the charge packets to flow from the CCD array to the amplifier input. The amplifier circuit converts each charge packet of the CCD array into a voltage which is proportional to the light incidence into the respective pixel. The evaluated charge must then be neutralized into the potential VOD via the pin RST.
(https://www.richis-lab.de/images/opticalsensor/04x16.jpg)
In the datasheet there is another blockdiagram that shows the function of the CCD image sensor in yet another way.
(https://www.richis-lab.de/images/opticalsensor/04x07.jpg)
The glass on the ceramic case is clear enough that you can take pictures of the integrated circuit without opening the case.
Apart from the sensor area, the whole die is covered with a metal surface. This ensures that no free charges are generated in the other circuit parts that would lead to unwanted current flows. The metal layer makes it difficult to analyze the circuit, but does not make it impossible.
(https://www.richis-lab.de/images/opticalsensor/04x08.jpg)
In the lower left corner of the die there is a copyright notice of the company DALSA from 1990 and the name of the device.
(https://www.richis-lab.de/images/opticalsensor/04x09.jpg)
The individual elements are clearly visible in the sensor area. The distribution of the potential VPR is clearly visible too. Controlled by the potential PR free charges in the sensor area can be diverted and thus neutralized.
The sensor area is framed with strips of the lower metal layer. It´s not 100% clear whether this frame is connected to the VB or the VBB potential. VB is the "Bias Voltage" which is usually connected to Vdd. VBB is the "Substrate Bias Voltage" to be connected to -3V-0V. The structures indicate that the inner area around the sensor is connected to the positive VB potential.
(https://www.richis-lab.de/images/opticalsensor/04x10.jpg)
(https://www.richis-lab.de/images/opticalsensor/04x11.jpg)
Controlled by the potential TCK the charges of the individual pixels flow into the CCD row below. Below the CCD row there are four wide lines of the lower metal layer, which carry the four phase-shifted transport clocks. Especially for the lower three lines, the contacts and the contours of the lines carrying the clock signals upwards are clearly visible.
Small square elements are connected to the lines carrying the outer potentials to the sensor. Most likely these are diodes that protect the circuit from problematic voltages. Since the gate structures have to be protected against too high circuits, it can be assumed that they are Z-diodes.
(https://www.richis-lab.de/images/opticalsensor/04x12.jpg)
The electrodes on the CCD line can only be guessed at. This is not only due to the small structures, but also because the electrodes overlap and show many contours in the metal layer.
(https://www.richis-lab.de/images/opticalsensor/04x13.jpg)
At the right end of the CCD row is the output amplifier, which receives an exclusive supply there. The VSS potential at the top right seems to serve just as shielding of the output signal.
(https://www.richis-lab.de/images/opticalsensor/04x14.jpg)
(https://www.richis-lab.de/images/opticalsensor/04x15.jpg)
The charge packets of the CCD array control the two-stage output amplifier and are then diverted to the right.
https://www.richis-lab.de/Opto13.htm (https://www.richis-lab.de/Opto13.htm)
:-/O
-
(https://www.richis-lab.de/images/led/09x01.jpg)
(https://www.richis-lab.de/images/led/09x11.jpg)
Kyocera sells the 910-00011-IT, a light source that is described as "LaserLight". The 910-00011-IT already includes a star-shaped metal core PCB. Alternatively, the light source itself can be purchased under the designation 910-00010-TR.
With 9V and 2,5A the LaserLight module delivers a luminous flux of 1000lm. The special feature is the small radiation area, which has a diameter of just 0,5mm. The luminance is 1300Mcd/m² and so is significantly higher than that of a LED or a high pressure gas discharge lamp. A small light source is very helpful when you want to create sharp light cones with small optics. One application are vehicle headlights that are intended to illuminate just certain areas of the road.
The datasheet shows the wavelengths contained in the light. The large, narrow-band blue component is striking. The CRI is accordingly just 70.
(https://www.richis-lab.de/images/led/09x02.jpg)
The small circuit diagram in the datasheet describes a series connection of two LEDs. A zener diode connected in parallel keeps negative voltages at a very low level and limits overvoltages, such as those that occur during ESD events.
(https://www.richis-lab.de/images/led/09x04.jpg)
In fact the 910-00011-IT does not contain normal LEDs, but so-called superluminescent diodes (SLD). The IEEE article "A Stripe-Geometry Double-Heterostructure Amplified-Spontaneous-Emission (Superluminescent) Diode" (IEEE Journal of Quantum Electronics, August 1973) shows a possible construction of an SLD.
The design strongly resembles a semiconductor laser (edge emitter). The light from a pn junction is amplified in a channel and coupled out at the edge of the device. In a semiconductor laser there are semi-transparent mirrors at the edges. Optical resonance sets in between the mirrors.
A superluminescent diode also uses the effect that the light beam is amplified in the channel. In contrast to a laser diode, however, the aim is to prevent reflections at the edges. This goes so far as to make the edges slightly slanted so that reflected components are not directed back into the channel. Even reflections at optical fibers, into which one wants to couple the light, can be problematic. Sometimes the rear area of the channel is designed as an optical termination. The IEEE article describes that this is easier to implement than a surface with very low reflections.
The emitted light beam offers a very high luminance like a laser. At the same time, the bandwidth of the light is wider, similar to a light emitting diode. A higher bandwidth is advantageous if white light is to be generated via a luminescent material. Strictly speaking, the term "laser" is wrong here, because the laser effect is not supposed to start with a superluminescent diode.
(https://www.richis-lab.de/images/led/09x03.jpg)
(https://www.richis-lab.de/images/led/09x05.jpg)
The pictures of the 910-00011-IT are not mine. They were taken by the user "dominic_m833" from the mikrocontroller.net forum. He allowed me to use them.
On the right and on the left side there is a superluminescent diode. The optical axes are slightly offset vertically. The areas above the SLDs have been blackened. In the center is the yellow luminescent material used to generate the white light. The Z-diode is mounted in the upper right corner.
(https://www.richis-lab.de/images/led/09x06.jpg)
Viewed from the side, it can be clearly seen that the SLDs are located on wedge-shaped structures that ensure that the light rays strike the luminescent material from above.
(https://www.richis-lab.de/images/led/09x07.jpg)
The SLDs has very low impedance contacts. The upper metal contacts the channel from above. The potential of the lower metal is conducted to the lower layers just before the channel begins.
(https://www.richis-lab.de/images/led/09x08.jpg)
In normal operation hardly any light from the lasers can be seen.
(https://www.richis-lab.de/images/led/09x09.jpg)
If you adjust the exposure appropriately, you can see where the light rays from the superluminescent diodes hit.
(https://www.richis-lab.de/images/led/09x10.jpg)
You can enhance the light of the superluminescent diodes too. 8)
https://www.richis-lab.de/Opto14.htm (https://www.richis-lab.de/Opto14.htm)
:-/O
-
(https://www.richis-lab.de/images/led/09x12.jpg)
The guy who took the pictures of the Kyocera 910-00011-IT compared it with one of the brightest LEDs, the OSRAM KW CELMM1.TG. :o
https://www.richis-lab.de/Opto14.htm#Vergleich (https://www.richis-lab.de/Opto14.htm#Vergleich)
:-/O
-
It seems I was wrong. The 910-00011-IT uses laser diodes, not superluminescent diodes. :palm:
-
LASER is supposed to produce coherent light.
Fig.1 reads "incoherent output beam".
-
The output light is incoherent but the initial source can be coherent. It is transformed in the phosphor.
-
(https://www.richis-lab.de/images/led/09x04.jpg)
From this image I understand the beam is not coherent, and it looks like that's the beam before entering into the phosphorus. So the SLD (Super Luminiscent Diode) LED is not a L.A.S.E.R. device. Isn't that so?
-
You are right, a SLD gives incoherent light.
But in every datasheet of these Kyocera LaserLights you just find the word laser. There is sometimes the acronym SLD but that doesn't mean Superluminescent Diode but Soraa Laser Diode Inc., a company that was bought by Kyocera (and again "Laser").
I somehow wanted to believe they use Superluminescent Diodes but it looks like that are Laser diodes. There is no hint that they use SLD. :-//
-
LASER is supposed to produce coherent light.
Fig.1 reads "incoherent output beam".
The coherence length of most lasers is very small, so the light is no longer coherent where it gets used. Special steps have to be taken to get a useful coherence length, like special construction and temperature control. For instance you cannot make an interferometer from any common laser source.
Laser diodes routinely have a coherence length of millimeters.
-
(https://www.richis-lab.de/images/led/10x01.jpg)
With the 5082-7300 Hewlett Packard produced a digit display which, due to its larger number of leds, allows a somewhat more natural image than a 7-segment display. The devices were produced at least until 1999, since there is a datasheet from Agilent and Agilent was spun off from Hewlett Packard in 1999.
(https://www.richis-lab.de/images/led/10x03.jpg)
The above block diagram is taken from the datasheet and shows how the display works. The 5082-7300 has a BCD interface and a latch. It provides a decimal point to the right of the number. Parallel to this, the 5082-7302 was available, which displays the decimal point to the left of the number. The third variant 5082-7340 has no decimal point at all. The input freed there makes it possible to switch off the complete display. While the 5082-7300 and the 5082-7302 just shows numbers and a minus sign (and a test pattern), the 5082-7340 is a hexadecimal display.
(https://www.richis-lab.de/images/led/10x02.jpg)
The red colored, but otherwise transparent housing allows a closer look at the circuitry without further processing. The control IC is clearly visible in the lower area. Above it are 20 LEDs, which are grouped into 13 segments. In addition, there is the decimal point.
(https://www.richis-lab.de/images/led/10x04.jpg)
The image quality is almost sufficient to analyze the circuit of the control IC in more detail.
(https://www.richis-lab.de/images/led/10x05.jpg)
The LEDs are easy to recognize too. The continuing bond connection is particularly interesting. According to the optical appearance, the bondwire was pressed onto the die and from there led directly to the next contact.
In this picture, one could think that it is a MESA structure, but it will be shown that this is not the case.
(https://www.richis-lab.de/images/led/10x06.jpg)
A simple way to expose the circuit is to thermally decompose the case. This reveals that the circuit itself is protected by a silicone-like potting and the red plastic is merely a cover.
(https://www.richis-lab.de/images/led/10x07.jpg)
In detail you can see that some bond joints have come loose. Bonded joints are not mechanically overly stable, yet the number of loosened wires is surprising, while otherwise hardly any mechanical impact can be seen.
(https://www.richis-lab.de/images/led/10x08.jpg)
(https://www.richis-lab.de/images/led/10x09.jpg)
The LEDs have an edge length of 0,45mm. The metal layer is designed to cover as little area as possible and thus remain as translucent as possible.
(https://www.richis-lab.de/images/led/10x11.jpg)
(https://www.richis-lab.de/images/led/10x10.jpg)
The dimensions of the control IC are 2,1mm x 2,0mm.
(https://www.richis-lab.de/images/led/10x12.jpg)
There is an hp logo on the lower edge of the die. A173B could be an internal project designation.
(https://www.richis-lab.de/images/led/10x13.jpg)
On the upper edge (image is rotated 180°) are five different squares, which probably served to monitor the manufacturing process. In the right corner are some numbers that look similar to the squares and so probably document the masks used. Clearly visible are the numbers 2, 3, 4 and 5. The remains below the 5 should probably represent a 6 and stand for the metal layer. This is plausible as far as it goes, since the metal layer often cannot be structured as precisely as the other areas. Above the 2, there could still be a 1.
(https://www.richis-lab.de/images/led/10x14.jpg)
:-//
(https://www.richis-lab.de/images/led/10x15.jpg)
The individual circuit parts can be easily identified. The evaluation of the latch enable input is located in the lower area of the die (orange). It controls the five latches (yellow) which store the data of the BCD interface and the decimal point.
Each buffer passes the input signal normally and complementary to the first decoder matrix (blue), which generates control signals for 16 characters. Another decoder matrix (green) takes over the control signals and activates the LEDs representing the desired character. The upper decoder seems to be built in I2L technology, as described in more detail in the CA3161 (https://www.richis-lab.de/logic22.htm (https://www.richis-lab.de/logic22.htm)).
On the outside there are 14 output stages (red), which are controlled by the upper decoder matrix and activate the necessary LEDs. In the lower left corner is a circuit with a relatively large capacitor (purple). Apparently this is used to set the current through the output stages and thus through the LEDs. The left two bondpads in the bottom row are probably used to set this current. One of the bondpads is connected to Vcc in this device, the other one remained open. The potential that controls the current through the output stage transistors is fed to a bondpad in the lower right corner of the die, which most likely can be used for blanking.
It is quite possible that this integrated circuit was also used to drive the 5082-7340. This is supported by the blanking function and the fact that the decoders are designed to display 16 characters, although the 5082-7300 can just display 12 characters (0-9, minus and "all elements"). For the 5082-7340, however, the decoder must then be adapted to the different character set.
https://www.richis-lab.de/Opto15.htm (https://www.richis-lab.de/Opto15.htm)
:-/O
-
I remember seeing those in the selection guides, and I have the HP databook for them somewhere, but they were always too expensive to use.
-
Are there any photos with decapped receiver ICs for consumer IR remotes, the ones with 3 pins V+, GND and digital Output like the TSOP or TFM series? https://www.datasheetarchive.com/pdf/download.php?id=acce405bdd62e21b56baae28844e8f659b2c21&type=P&term=TFM%25201380%2520T%2520infrared%2520receivers (https://www.datasheetarchive.com/pdf/download.php?id=acce405bdd62e21b56baae28844e8f659b2c21&type=P&term=TFM%25201380%2520T%2520infrared%2520receivers)
At a closer look it seems that there were 6 terminals out of which 3 were cut out, as seen in the attached photo.
Asking because I've read some have a PIN fotodiode, and the block diagram shows an integrated transimpedance amplifier. Would be great if the analog signal would be accessible, so the IC could be use as an analog PIN detector.
-
I don´t know such pictures.
We should take a closer look! :-/O
-
(https://www.richis-lab.de/images/led/11x01.jpg)
(https://www.richis-lab.de/images/led/11x02.jpg)
The VQ130 built by the "Werk für Fernsehelektronik Berlin" is an IR-LED designed to transmit data via optical fibers. A typical receiver is the SP104 photodiode. According to the datasheet, the VQ130 can be operated with up to 300mA. A radiation power of up to 130µW is emitted. The emitted wavelengths range between 820nm and 870nm.
(https://www.richis-lab.de/images/led/11x03.jpg)
The datasheet contains a drawing of the complete module. The LED is located in a round housing that can be screwed into a heatsink. Besides the GaAs LED the VQ130 also contains a Si photodiode for monitoring the current beam power. For this reason, the module has four pins. A piece of optical fiber is integrated into the housing, which leads to an optical fiber connector.
(https://www.richis-lab.de/images/led/11x04.jpg)
(https://www.richis-lab.de/images/led/11x05.jpg)
The housing is constructed in two parts. Onto the lower element a cylinder is glued, which resembles a screw, and the optical waveguide is crimped into a thinner cylinder at the end.
The screw-shaped part is hollow and leads the pins to the outside. A potting protects the leads and seals the housing.
(https://www.richis-lab.de/images/led/11x07.jpg)
(https://www.richis-lab.de/images/led/11x06.jpg)
As specified in the datasheet, markings are stamped on the side. The W could stand for the manufacturer, whereas the "Werk für Fernsehelektronik" usually used the letters WF as an abbreviation. The meaning of the numbers 1421 remains unclear.
(https://www.richis-lab.de/images/led/11x08.jpg)
The end of the optical fiber is equipped with a screw connection.
(https://www.richis-lab.de/images/led/11x09.jpg)
There are some characters on the connector whose meaning remains unclear. The department standard TGL55141/01 specifies fiber optic cables and their designations. However, these designations do not seem to match the present character string. The datasheet of the VQ130 refers to the standard TGL55141/02, but this cannot be found.
VD could stand for a December 1987 production.
(https://www.richis-lab.de/images/led/11x10.jpg)
Removing the cylinder reveals that the connection pins lead to a round module that carries the photodiode. The connection to the LED, which is still in the cylinder, is torn off when it is opened.
(https://www.richis-lab.de/images/led/11x11.jpg)
A larger, round metal part that remains in the cylinder carries the LED. The cathode potential of the transmitter is led via two bondwires connected in parallel to a ceramic block and from there to the LED.
The round metal element was apparently connected to the lower part of the VQ130 just by some kind of glue. During assembly, the cylinder was probably put over as a last part, so it was possible to create the bond connections between the lower part and the carrier of the LED beforehand. Although most of the elements were only glued together, the electrical resistance of these connections seems to be low enough to use them as conductors to the LED's anode.
(https://www.richis-lab.de/images/led/11x12.jpg)
The photodiode is located on a ceramic carrier and is thus electrically isolated from the LED. The cathode potential is led to the ceramic carrier by two bondwires.
On the right pin, you can still see the remains of the two bondwires that connected the LED.
(https://www.richis-lab.de/images/led/11x13.jpg)
The edge length of the photodiode is 1,2mm.
(https://www.richis-lab.de/images/led/11x14.jpg)
There is some dirt and damage on the surface of the photodiode.
(https://www.richis-lab.de/images/led/11x15.jpg)
The bondwires that feed the LED's cathode potential from the ceramic block have both come loose from the semiconductor.
(https://www.richis-lab.de/images/led/11x16.jpg)
The detail clearly shows that the bondwires were pressed onto the die, but then came loose again.
(https://www.richis-lab.de/images/led/11x17.jpg)
(https://www.richis-lab.de/images/led/11x18.jpg)
The cylindrical upper part of the VQ130 is only slightly glued to the casing and can be easily removed from it after the optical fiber has been cut off. It can be seen that the carrier structure consists of two parts. The optical waveguide passes through a hole in the larger element and is glued there. The LED is located on a semi-circular disk, which is just glued to the upper element. It could be that this bisection served to align the LED with the optical waveguide.
(https://www.richis-lab.de/images/led/11x19.jpg)
(https://www.richis-lab.de/images/led/11x20.jpg)
(https://www.richis-lab.de/images/led/11x21.jpg)
(https://www.richis-lab.de/images/led/11x22.jpg)
The optical waveguide runs centrally through the cylindrical structure and ends in a trench, where it is fixed with a kind of clear potting. Inside the potting, the contours of the optical waveguide are no longer visible. The diameter of the optical waveguide is approximately 130µm. A standard value would be 125µm. Measurement tolerances could be the reason for this difference. The core of such an optical fiber usually had a diameter of 66µm or 50µm.
(https://www.richis-lab.de/images/led/11x23.jpg)
(https://www.richis-lab.de/images/led/11x24.jpg)
There is a sphere at the end of the optical waveguide. The slightly dark coloration in this area suggests that the sphere was glued on. The geometry probably optimizes the coupling of the light emitted by the semiconductor.
The dimensions of the LED are 0,40mm x 0,19mm. In the lower right corner you can see a crack. In the center, the die is discolored. Maybe the semiconductor was overloaded. It could be that at some point the left bondwire came loose, resulting in a current concentration on the right side that ultimately destroyed the structures.
(https://www.richis-lab.de/images/led/11x25.jpg)
(https://www.richis-lab.de/images/led/11x26.jpg)
The front side, where the light couples into the optical waveguide, is very smooth. The lateral radiation over a very smooth surface would be typical for a laser diode. It could be that diodes were used here whose quality was not sufficient to be able to operate them as laser diodes.
The upper edges at the short sides of the die are beveled. Presumably, this shape resulted from separating or reworking the lateral surfaces. Where the optical waveguide faces the die, one thinks one can detect a disturbance, an impurity or damage.
(https://www.richis-lab.de/images/led/11x27.jpg)
Here, the damage on the die can be seen even more clearly. While the left bondwire has apparently only come loose, the right contact surface is more severely damaged. This supports the theory that the left bondwire came loose first and then the LED was damaged by the local overload, which ultimately caused the right bondwire to come loose as well.
https://www.richis-lab.de/Opto16.htm (https://www.richis-lab.de/Opto16.htm)
:-/O
-
(https://www.richis-lab.de/images/led/12x01.jpg)
The VQ150 is an infrared laser diode that can be used in data transmission links with optical fibres. The manufacturer is the Werk für Fernsehelektronik Berlin. However, experts suspect that only the final assembly took place at the Werk für Fernsehelektronik and that the production of the laser diodes itself took place at the ZIE (Zentralinstitut für Elektronenphysik).
The VQ150 was presented at the Leipzig Spring Fair in 1987, but apparently could not be ordered for a long time. The model in the picture above bears the date 13.05.1991. Fittingly, the former "Volkseigener Betrieb" had already changed into a "GmbH" (limited liability company).
The wavelength of the VQ150 is between 820nm and 860nm, with a bandwidth of 1nm to 4nm. At 190mA, the laser diode emits a power of 2mW (3mW peak). The threshold voltage at which the laser effect starts is between 60mA and 120mA. The switching times are specified with a maximum of 1ns. Typical for laser diodes is the low permissible reverse voltage of just 1V. Laser diodes are also very sensitive to electrostatic discharges.
(https://www.richis-lab.de/images/led/12x02.jpg)
In the following, another VQ150 is analysed. On this model, the designation is not engraved into the casing, but is printed in black.
(https://www.richis-lab.de/images/led/12x03.jpg)
The "Fachbereichstandard" TGL42942, which describes the characteristics of the VQ150, includes the above drawing. A photodiode monitors the light output of the laser diode. A Peltier element keeps the laser diode at an optimal temperature. A thermistor can be used to create a control loop. Temperature fluctuations would influence both the wavelength and the efficiency of the laser diode.
(https://www.richis-lab.de/images/led/12x05.jpg)
(https://www.richis-lab.de/images/led/12x04.jpg)
(https://www.richis-lab.de/images/led/12x08.jpg)
The VQ150 is equipped with a piece of optical fibre that ends in a connector.
(https://www.richis-lab.de/images/led/12x06.jpg)
(https://www.richis-lab.de/images/led/12x07.jpg)
The characters printed on the shrink tubing of the fibre optic connector apparently belong to the designation of the fibre optic cable. According to the "Fachbereichstandard" for the VQ150, the full designation of the fibre optic cable is "LWL-VK NRÜ 131 EBS-GO 3006 4112".
W9 presumably stands for production in September 1988.
(https://www.richis-lab.de/images/led/12x09.jpg)
(https://www.richis-lab.de/images/led/12x12.jpg)
(https://www.richis-lab.de/images/led/12x10.jpg)
The VQ150 has a gold-plated housing. The number 3524 is stamped on the side, a consecutive number according to the "Fachbereichstandard".
(https://www.richis-lab.de/images/led/12x13.jpg)
(https://www.richis-lab.de/images/led/12x11.jpg)
The cover and the sleeve of the fibre optic cable are welded to the housing. However, the welding of the sleeve was not completed.
The sleeve has two holes on the top, which were certainly used to fix the optical fibre and seal the system.
(https://www.richis-lab.de/images/led/12x16.jpg)
(https://www.richis-lab.de/images/led/12x17.jpg)
When the case is opened, a golden layer comes off the surface, which appears silver on the back. It is interesting that the case underneath is gold-coloured again.
[...]
:-/O
-
(https://www.richis-lab.de/images/led/12x14.jpg)
(https://www.richis-lab.de/images/led/12x15.jpg)
(https://www.richis-lab.de/images/led/12x34.jpg)
The wiring shows that the production involved a lot of manual work.
(https://www.richis-lab.de/images/led/12x18.jpg)
In the "Industriesalon Schöneweide" (https://www.industriesalon.de (https://www.industriesalon.de)), a display board shows the manufacturing steps in the production of a VQ150. The individual elements can be easily identified in this module.
(https://www.richis-lab.de/images/led/12x19.jpg)
Even if it does not appear so at first glance, the construction is quite clear. The optical waveguide is fed into the housing from the right through a sleeve. The laser diode is located where the optical waveguide ends. Behind it is the photodiode. On the far left, the Peltier element ensures a constant temperature. To the right of the laser diode is the associated thermistor.
(https://www.richis-lab.de/images/led/12x20.jpg)
There are some splashes of solder in the casing.
(https://www.richis-lab.de/images/led/12x21.jpg)
The optical fibre is guided into the housing through a sleeve. A nickel tube protects the glass fibre.
(https://www.richis-lab.de/images/led/12x22.jpg)
The optical elements are fixed on a module, which is called "Aufnahme" on the WF display board. The "Aufnahme" carries the photodiode and has a notch into which the tube with the optical fibre is inserted and soldered.
In a space between the photodiode and the glass fibre, the so-called "Träger" is inserted, on which the laser diode is located. The "Träger" seems to have been glued. Probably the laser was aligned with the glass fibre.
On the "Träger", next to the WF logo, are the numbers 03377. Presumably, the sequence of numbers serves to trace the laser module.
(https://www.richis-lab.de/images/led/12x23.jpg)
(https://www.richis-lab.de/images/led/12x24.jpg)
Since the laser light emerges from the laser diode on both sides, the photodiode can be arranged opposite the optical waveguide and thus the currently emitted light power can be determined.
With respect to the laser diode, the photodiode is slightly rotated around both the vertical and horizontal axes. This measure ensures that light reflected from the photodiode does not hit the laser diode or the optical waveguide.
(https://www.richis-lab.de/images/led/12x25.jpg)
(https://www.richis-lab.de/images/led/12x26.jpg)
The laser diode is placed on a carrier which, according to the diagram, consists of silicon. While the laser diode is based on GaAs according to the datasheet, the diagram specifies AlGaAs as base material. Usually, laser diodes are produced with both materials. The different bandgaps are used to build the structures necessary for a laser.
(https://www.richis-lab.de/images/led/12x29.jpg)
(https://www.richis-lab.de/images/led/12x27.jpg)
(https://www.richis-lab.de/images/led/12x28.jpg)
The dimensions of the laser diode are 0,40mm x 0,20mm. The current flows through the semiconductor from the bottom to the top. It is a classic edge emitter in which the laser light is emitted via the side surfaces. These side surfaces are correspondingly smooth.
The upper edges on the short sides of the die are bevelled. The bondpads contain notches. The same component seems to have been used as in the IR-LED VQ130, which supports the theory that laser diodes of insufficient quality were used as normal IR-LEDs.
The diameter of the glass fibre can be determined to be approximately 0,13mm. While in the IR-LED VQ130 a kind of sphere was placed at the end of the glass fibre, in the VQ150 it was left pointed. But the end is still rounded. As with the VQ130, the last piece seems a little darker, as if it had been treated with some kind of varnish.
The distance between the laser diode and the glass fibre is just 10µm.
(https://www.richis-lab.de/images/led/12x30.jpg)
(https://www.richis-lab.de/images/led/12x31.jpg)
The photodiode is located on a ceramic carrier on the so-called "Aufnahme". The upper potential is supplied with two bondwires.
(https://www.richis-lab.de/images/led/12x35.jpg)
The Peltier element connects the "Aufnahme" to the area of the enclosure that must be screwed to a heatsink. In this way, the heat generated can be dissipated as efficiently as possible. Since the "Aufnahme" does not otherwise touch the enclosure, it is relatively well insulated thermally. The datasheet specifies 4V and 0,75A as maximum values for the Peltier element.
(https://www.richis-lab.de/images/led/12x32.jpg)
The Peltier element shows the typical structure. There are differently doped semiconductor cuboids between two white ceramic plates. Depending on the doping, the current is allowed to flow through the cuboids from one direction or the other. The different energy levels between the semiconductor and the contacting metal lead to heat emission on one side and heat absorption, i.e. cooling, on the other side.
(https://www.richis-lab.de/images/led/12x33.jpg)
The red thermistor is glued into a large bulge of the "Aufnahme" opposite the Peltier element.
https://www.richis-lab.de/Opto17.htm (https://www.richis-lab.de/Opto17.htm)
:-/O
-
(https://www.richis-lab.de/images/opto/03x01.jpg)
The IR 6 is a passive infrared motion detector from Telenorma. It requires a supply voltage between 10,5V and 15V. In addition to the alarm output, the IR 6 offers tamper protection, where a control loop is interrupted when you open the housing. On the front side there is only an inconspicuous white window transparent to infrared radiation.
(https://www.richis-lab.de/images/opto/03x03.jpg)
The datasheet shows the detection ranges of the sensor. Five areas extend in the horizontal plane over an opening angle of 90°. The range depends on the angle at which the sensor is mounted on the wall and is up to 14m. At close range, the IR 6 has two additional detection zones.
(https://www.richis-lab.de/images/opto/03x02.jpg)
If you remove the cover, you can see the back of a circuit board. The module has been rotated by 180° here. The contact strip is on the left, and a window on the right provides an entry point for infrared radiation. The tamper protection is located in between. A pin fixed in the cover presses there through a hole in the board onto a metal part which closes the loop of the tamper protection.
The orange LED is a so-called walk test indicator. According to the datasheet, it is not visible through the housing, but can also be unplugged. This ensures that no unauthorized person can test the detection range.
(https://www.richis-lab.de/images/opto/03x04.jpg)
Infrared sensors for motion detectors usually offer very few, usually only two elements. The desired resolution over a large area is achieved using Fresnel lenses or concave mirrors. These optical elements ensure that the irradiation on the sensor changes relatively strongly, even if only a small heat source moves through the room.
If the circuit board is removed, the concave mirror becomes visible, which in the case of IR 6 directs the incoming infrared radiation to the sensor and thus defines the detection areas. Areas 1-5 are the more far-reaching zones. Surfaces 6 and 7 collect the infrared radiation from the near range.
(https://www.richis-lab.de/images/opto/03x06.jpg)
Turned by 180° again, the transition from the wide-range to the close-range reflectors can be clearly seen through the cutout in the pcb. The actual sensor is located under the black element.
(https://www.richis-lab.de/images/opto/03x05.jpg)
The circuit is not too complex. Usually the signals of the sensor are actively filtered and amplified. Approximately in the center you can see the metal element of the tamper protection and above it the relay that switches the output of the motion detector.
(https://www.richis-lab.de/images/opto/03x07.jpg)
The sensor is covered with a plastic element on the back. Perhaps this ensures that no infrared radiation falls on the pins and generates inhomogeneous heating. Such sensors are extremely sensitive and it is quite conceivable that an inhomogeneous heating of the pins already generates a problematic interference signal.
The sensor lies directly on the circuit board. However, you must not heat the sensor elements too much. The datasheet recommends to leave the pins at least 6,35mm long. This explains why the pins are bent downwards and soldered further away of the sensor.
(https://www.richis-lab.de/images/opto/03x08.jpg)
On the front side there is a square window with a filter element.
(https://www.richis-lab.de/images/opto/03x09.jpg)
(https://www.richis-lab.de/images/opto/03x10.jpg)
(https://www.richis-lab.de/images/opto/03x11.jpg)
The labeling on the side shows that it is the Dual IR detector 5192 from Eltec. The number 3 behind the designation shows which filter is located in front of the sensor. 3 stands for the silicon filter, which allows wavelengths between 6µm and 25µm to pass. A total of 35 different filters are available. 4784 seems to be a date code.
(https://www.richis-lab.de/images/opto/03x12.jpg)
The datasheet shows that there are two sensor elements in the housing.
(https://www.richis-lab.de/images/opto/03x24.jpg)
In the datasheet, reference is made to patent US4523095, whose illustrations make it easier to understand how the sensor works. If only a single pyroelectric element were used as a sensor, a warm body in the detection range would just cause the output signal to increase (Fig. 5).
In contrast, the arrangement and interconnection of two pyroelectric elements and the evaluation via a differential amplifier results in an oscillating signal when passing through the detection areas (Fig. 6). This signal is easier to evaluate.
(https://www.richis-lab.de/images/opto/03x21.jpg)
If you open the housing, you can take a look at the glued-in filter element.
(https://www.richis-lab.de/images/opto/03x14.jpg)
(https://www.richis-lab.de/images/opto/03x16.jpg)
The two pyroelectric elements are mounted on a ceramic carrier. It can be seen that the right element is broken off. The damage could have occurred when opening the case. However, the module in question was discarded because its functionality was unreliable. This suggests that the element had already broken off before.
(https://www.richis-lab.de/images/opto/03x20.jpg)
So-called security bonds were used on the connecting pins. A ball bond is supposed to secure the wedge bond.
(https://www.richis-lab.de/images/opto/03x13.jpg)
The datasheet shows how the sensor works. The two pyroelectric elements are connected antiparallel and are guided to the gate of a JFET. This interconnection ensures that when an infrared beam changes from one element to the other, the polarity of the signal is reversed. The JFET represents the differential amplifier shown in the patent above. The value of the resistor R_L is extremely high at 105GΩ. Such a high value is necessary because the pyroelectric elements have a very high internal resistance.
(https://www.richis-lab.de/images/opto/03x23.jpg)
It seems that the sensor can be obtained with lower resistance values. Since R_L discharges the capacity of the sensor, a lower value has a positive effect on the bandwidth. At the same time, however, the sensitivity is reduced.
(https://www.richis-lab.de/images/opto/03x15.jpg)
With the background of the operation one can interpret and extrapolate the structures. On the left pyroelectric element, the top is connected to the gate of the JFET. On the right element, the bottom side is directly connected to the gate potential due to the attachment. It can be assumed that the top was connected to the rest of the ball bond on the right of the element (yellow). The extremely high resistance thick film resistor is applied to the ceramic support between the gold contacts.
The significance of the imprint between the thermoelectric elements remains open. It does not appear to be a proper wedge bond. It also lacks the security bond. This suggests that it was not a functional element. Perhaps it is a remnant of the manufacturing process.
(https://www.richis-lab.de/images/opto/03x18.jpg)
Pyroelectric elements can be manufactured from different materials. On Eltec's website, only lithium tantalate is ever mentioned.
(https://www.richis-lab.de/images/opto/03x19.jpg)
Since it was not possible to bond on the pyroelectric material, the bondwire was soldered.
(https://www.richis-lab.de/images/opto/03x17.jpg)
(https://www.richis-lab.de/images/opto/03x22.jpg)
The edge length of the JFET is 0,35mm. The mode of operation can be seen clearly. The two adjacent bondpads contact a wide n-doped strip, which is located in a p-doped area. A thin p-doped strip is deposited on the wide strip, forming an n-doped channel surrounded by p-doped regions over its complete circumference.
Inside the sensor, the gate potential is supplied from below through the substrate. The free bondpad in the lower area offers the possibility to supply the gate potential alternatively via a bondwire.
https://www.richis-lab.de/Opto18.htm (https://www.richis-lab.de/Opto18.htm)
:-/O
-
Thanks, never seen one opened before! :-+
Mythbusters, the TV show, have had an episode about how to defeat IR alarms. IIRC, by putting a sheet of glass in front of the sensor, or by crossing the room while keeping a bed-sheet towards the sensor and hiding behind it, was possible to become IR invisible for the sensor.
-
:-+
I heard it should be possible to defeat these IR sensors with styrofoam too.
Looking through a thermal camera it is suprising for me that such camouflage is able to defeat IR sensors.
All these methods show a uniform temperature. However in a room there are a lot of parts looking very different, in infrared too. So if you put a bed-sheet over these parts the IR picture is changing and the sensor should recognize that. :-//
-
Fascinating images.
How easily a PIR sensor can be beaten depends more on the amplifier and comparator stages than the element itself. Simple gain adjustment changes the sensitivity, with the obvious trade off that you can get false detects. With some processing in place of a simple comparator it's possible to get significant improvement, though getting the lens right is the real key.
-
The weirdest thing is how they atached the wire to the pyroelectric material. ???
The pyroelement looks porous and not solder friendly. Combined with the extra measures required to avoid heat while mounting the entire sensor to the PCB, my best guess is the internal bonding to the pyroelements was made with some sort of conductive glue. Wouldn't be surprised if that would be a glue that soften and melt at small temperatures, and thus the extra care when mounting the sensor. These are only speculations, no idea how it really is.
Anybody knows any details about bonding the wires to the pyroelectric material?
-
Thanks, never seen one opened before! :-+
Mythbusters, the TV show, have had an episode about how to defeat IR alarms. IIRC, by putting a sheet of glass in front of the sensor, or by crossing the room while keeping a bed-sheet towards the sensor and hiding behind it, was possible to become IR invisible for the sensor.
If my memory is right they tested two types of sensors: IR and ultrasound. For the IR it was possible to defeat them by moving very slowly and the bed-sheet was somewhat successful against the ultrasound sensors.
-
A small update to the VQ150:
(https://www.richis-lab.de/images/led/12x36.jpg)
The magazine "Nachrichtentechnik Elektronik" (issue 5, 1989) contains an article about the VQ150. In it, one possible application is the fiber optic transmitter board of the DÜS-LL-34 system. 480 telephone connections can be transmitted simultaneously via the DÜS-LL-34. With 11 repeaters transmission distances up to 120km are possible. The datarates here are 34MBit/s. Theoretically, up to 167MBit/s should be achievable with the VQ150.
(https://www.richis-lab.de/images/led/12x38.jpg)
The above mentioned magazine "Nachrichtentechnik Elektronik" contains a circuit diagram which shows how a circuit around the VQ150 can look like.
In the upper part is the temperature control, which is monitored to the right with a comparator. The current through the laser diode is made up of two parts. The circuit in the lower section provides a certain base current, which always flows through the laser diode. The digital signal on the left passes through a differential amplifier and then causes the current through the laser diode to increase, resulting in a laser pulse. If the input signal fails, which is relatively evenly distributed, then a circuit ensures that the idle current is also switched off. This prevents the laser diode from aging unnecessarily. Another comparator activates the alarm output when the idle current fails.
(https://www.richis-lab.de/images/led/12x37.jpg)
And here we see a side view of the architecture.
https://www.richis-lab.de/Opto17.htm (https://www.richis-lab.de/Opto17.htm)
:-/O
-
(https://www.richis-lab.de/images/opto/04x01.jpg)
The component shown here is from the DT8380 infrared thermometer (https://www.richis-lab.de/DT8380.htm (https://www.richis-lab.de/DT8380.htm)). It is a so-called thermopile. The window on the upper side is transparent for infrared radiation. Inside is a series connection of thermocouples, which generate a voltage proportional to the thermal radiation.
The housing does not bear any labeling. The designation of the component remains unclear, as does the manufacturer.
(https://www.richis-lab.de/images/opto/04x08.jpg)
A cuboid glued into the lid of the housing represents the optical window.
(https://www.richis-lab.de/images/opto/04x02.jpg)
(https://www.richis-lab.de/images/opto/04x03.jpg)
Inside the case is a large die that represents the thermopile. It is connected to two pins via two bondwires.
(https://www.richis-lab.de/images/opto/04x09.jpg)
A thermistor allows to meassure the reference temperature of the thermopile.
(https://www.richis-lab.de/images/opto/04x04.jpg)
The article "Design and Fabrication of a Low-Cost Thermopile Infrared Detector" published in the journal Micromachines shows the structure of such a thermopile. The active part is located above a large cavity. This construction method is the reason why such thermopiles belong to the MEMS family.
The so-called hot junctions are arranged around the inner circle. In this area, the contact points of two different materials form thermocouples. A thermoelectric voltage proportional to the temperature drops across them. The series connection of the thermocouples also results in thermocouples in the outer area, the so-called cold junctions. The outer thermocouples must be kept as close as possible to the reference temperature of the housing. For this reason, one tries to isolate the two areas as good as possible thermally from each other. The cavity ensures that just the thin wires are a relevant heat conductor.
(https://www.richis-lab.de/images/opto/04x07.jpg)
If you choose a slightly different focus, you can see the bottom of the housing through the active area.
(https://www.richis-lab.de/images/opto/04x15.jpg)
The edge length of the die on which the thermopile is integrated is 1,75mm. The character string OTP666C on the lower edge cannot be assigned to any sensor designation or manufacturer. The bonding areas in the lower corners are marked with - and +. The voltage of the thermopile can be tapped at these points.
The bondpads in the upper corners are connected with a long line that extends in many loops over the left, the right and the upper edge. Perhaps this is an option to determine the reference temperature of the thermopile. The integration of a heater seems to make little sense, but could possibly be useful in the context of a special adjustment.
(https://www.richis-lab.de/images/opto/04x10.jpg)
The so-called hot junctions (red) are located in the center under the black coating. If the infrared radiation heats these junctions, a temperature voltage proportional to this temperature is generated. The series connection of 116 thermocouples results in a relatively high output voltage. The cold junctions (cyan) are arranged in a square around the cavity.
(https://www.richis-lab.de/images/opto/04x11.jpg)
(https://www.richis-lab.de/images/opto/04x12.jpg)
A black coating with an rough surface is applied to the inner area. This ensures that as much infrared radiation as possible is absorbed and increases the temperature of the inner area.
The outer optics of the DT8380 infrared thermometer reduces the risk of infrared radiation hitting the outer area of the thermopile and heating the cold junctions there, which would falsify the measurement.
(https://www.richis-lab.de/images/opto/04x05.jpg)
(https://www.richis-lab.de/images/opto/04x06.jpg)
The article mentioned above deals in more detail with the shape of the hot junctions, which are not visible in the present component due to the coating.
(https://www.richis-lab.de/images/opto/04x13.jpg)
(https://www.richis-lab.de/images/opto/04x14.jpg)
For each thermocouple, an on average ~20µm wide polysilicon strip leads to the inner contact. On top of the silicon strip is the corresponding aluminum strip, which is considerably narrower at about 4µm. In the edge area, the metal layer then contacts the next polysilicon line.
In the tilted image showing the coating it can be seen that the lines are much wider than they are high. It can therefore be estimated that the lines are just a few micrometers high.
https://www.richis-lab.de/Opto19.htm (https://www.richis-lab.de/Opto19.htm)
:-/O
-
Wow, thanks! I've become very curious about the inner structure after buying an infrared thermometer, the cheap one without thermal camera. Very nice toy.
It's all fun measuring temperatures around, until you go outside and measure the temperature of the night sky... :o
-
It was a pleassure! :)
That´s one of those things everybody uses and just a few know what exactly is inside and how it works. I wasn´t aware of the structures either until I took these pictures and read some articles about thermopiles.
-
Cool. Saw a design some years ago using thermopiles for flame detection, don't remember the part numbers though. Think they were a rectangular design. Don't think they were cheap...
Tim
-
Yes, there are different geometric shapes. I have seen rectangular designs too.
I assume if you can build MEMS structures than building such a thermopile is no big problem. Nevertheless it´s a MEMS structure and that is a special process with an appropriate price label.
-
I found the manufacturer of the thermopile:
(https://www.richis-lab.de/images/opto/04x16.jpg)
Oriental System Technology, never heard of them... ;D
This is the OTP638D2 but you can see the design is the same as in our thermopile.
https://www.richis-lab.de/Opto19.htm#OTP638D2 (https://www.richis-lab.de/Opto19.htm#OTP638D2)
:-/O
-
(https://www.richis-lab.de/images/led/13x01.jpg)
Here you can see one of the many laser modules that just require a supply voltage and are used for simple marking tasks. The beam power is usually less than 1mW, so no protective measures are necessary when using it. A manufacturer cannot be identified. The present module is taken from the DT8380 infrared thermometer (https://www.richis-lab.de/DT8380.htm (https://www.richis-lab.de/DT8380.htm)).
For a satisfactory and reliable function laser diodes need some electrical and optical auxiliary structures. For this reason, discrete laser diodes are not used for simple marking tasks, but ready to use modules like the one shown here.
(https://www.richis-lab.de/images/led/13x03.jpg)
(https://www.richis-lab.de/images/led/13x04.jpg)
The black shrink tubing at the rear end of the module protects a small pcb that adjusts the current through the laser diode. For this purpose, the current beam power is determined in the laser diode and regulated to a constant value.
Setting a constant current would not be sufficient because the beam power of a laser diode is strongly influenced by production fluctuations, temperature and aging. To make matters worse, if the current is set slightly too low, the laser threshold will not be reached and the laser diode will behave like a weak LED. If the current is set slightly too high, the laser diode will age very quickly and fail prematurely.
The specified beam power must never be exceeded for safety reasons. At the same time, optical power meters are often not at hand. This is another reason for setting the output power during production and and controlling it directly.
(https://www.richis-lab.de/images/led/13x05.jpg)
The circuit for power control is relatively simple. The transistor Q2 adjusts the current through the laser diode. Q2 is controlled by Q1. The photodiode is connected to the base of Q1. If the beam power increases, more current flows through the photodiode, Q1 is conducting more current, the base current of Q2 is reduced and so is the current through the laser diode.
MMBT3904 (https://www.richis-lab.de/BipolarA32.htm (https://www.richis-lab.de/BipolarA32.htm)) were used as transistors. At the input of the circuit there is a 100nF capacitor, which ensures that the circuit works stable. Of course, this module is not suitable for fast modulation.
(https://www.richis-lab.de/images/led/13x02.jpg)
(https://www.richis-lab.de/images/led/13x06.jpg)
A lens can be seen in the hole on the front. On the back, you can already see that a component has been installed in a metal sleeve.
(https://www.richis-lab.de/images/led/13x08.jpg)
(https://www.richis-lab.de/images/led/13x07.jpg)
If you cut open the metal sleeve, the lens becomes visible in the front area. This is the so-called collimator. Laser light is strongly bundled, but it does have a certain divergence. Consequently, a laser beam also fans out with increasing distance. The collimator reduces the divergence so that the laser beam comes even closer to an ideal light beam.
A closer look reveals that the upper sleeve has a thread. One could probably have unscrewed this element, which was secured with adhesive. A spring fixes the lens in place. During manufacture, the optimum distance of the lens can be set by simply turning the sleeve.
(https://www.richis-lab.de/images/led/13x09.jpg)
You can already see the laser diode...
(https://www.richis-lab.de/images/led/13x10.jpg)
The laser diode is located in the lower sleeve. The designation laser diode is common, but does not quite do justice to the assembly, since the photodiode for power measurement is also located in the casing.
The relatively massive bottom allows efficient heat dissipation. This is important in some applications, since temperature fluctuations strongly influence efficiency and wavelength.
(https://www.richis-lab.de/images/led/13x11.jpg)
(https://www.richis-lab.de/images/led/13x12.jpg)
The laser diode is soldered on a thick vertical metal element. The laser is an edge emitter. The laser beam is coupled out at the upper edge. Part of the light also leaves the edge emitter at the bottom and is used to determine the optical power. For this purpose, a photodiode is located below the laser diode. The photodiode is mounted on a slope so that reflected light is not emitted to the outside.
(https://www.richis-lab.de/images/led/13x14.jpg)
(https://www.richis-lab.de/images/led/13x13.jpg)
The bondwire of the photodiode has a ball bond on one side. The corresponding wedge bond is located on the other side. The laser diode was basically connected in the same way, but here an additional ball bond was placed on the wedge bond to secure the connection. Such a measure is called a security bond. Apparently, the bond connection was somewhat more critical with the laser diode, so that the additional security became necessary.
(https://www.richis-lab.de/images/led/13x15.jpg)
The dimensions of the laser diode are 0,29mm x 0,25mm x 0,1mm. The die is located on a relatively thick carrier, which in turn was soldered onto the metal post of the housing.
(https://www.richis-lab.de/images/led/13x16.jpg)
(https://www.richis-lab.de/images/led/13x17.jpg)
The front edge of the die is very smooth so that the laser radiation is disturbed as little as possible. Two things are also noticeable. On the one hand, the die protrudes a bit beyond the carrier and on the other hand, the inactive edges are clearly slanted.
(https://www.richis-lab.de/images/led/13x19.jpg)
(https://www.richis-lab.de/images/led/13x18.jpg)
The surface of the lateral edges is very rough. This is nothing unusual, but material seems to have broken out especially in the center (on both sides).
(https://www.richis-lab.de/images/led/13x20.jpg)
Photodiode - nothing special...
https://www.richis-lab.de/Opto20.htm (https://www.richis-lab.de/Opto20.htm)
:-/O
-
(https://www.richis-lab.de/images/led/13x21.jpg)
A laser diode only provides laser light above a certain current. This so-called laser threshold can be determined by increasing the current through the laser diode and simultaneously observing the current generated in the photodiode. From 11mA, the light output and thus the photocurrent increases sharply. From here on, laser light is generated. Before that, lossy effects dominate, which strongly reduce the efficiency.
(https://www.richis-lab.de/images/led/13x22.jpg)
At a current of 1mA, well below the laser threshold, the laser diode already shines clearly.
(https://www.richis-lab.de/images/led/13x23.jpg)
At a current of 15mA, the laser diode shines much brighter and it becomes increasingly difficult to capture high quality images of it.
(https://www.richis-lab.de/images/led/13x24.jpg)
The active layer is located on the surface facing the carrier / heatspreader. This makes sense because the thermal conductivity of the semiconductor material is relatively poor. The shorter path from the active area to the package enables more efficient heat dissipation.
(https://www.richis-lab.de/images/led/13x25.jpg)
In operation, the partial metallization on the bottom side becomes more clearly visible. In the open areas on the right and left, a brightness level is formed in each case, which results from the beveled edges. The beam diameter is about 20µm. Even with a beam power of just 1mW, a power density of 250W/cm² results on this surface.
https://www.richis-lab.de/Opto20.htm#Laserschwelle (https://www.richis-lab.de/Opto20.htm#Laserschwelle)
:-/O
-
"The photodiode is mounted on a slope so that reflected light is not emitted to the outside"
Not exactly, it is sloped to prevent reflections to the laser which will create amplitude oscillations, wavelength changes and changes in the modes.
-
"The photodiode is mounted on a slope so that reflected light is not emitted to the outside"
Not exactly, it is sloped to prevent reflections to the laser which will create amplitude oscillations, wavelength changes and changes in the modes.
Thanks for the correction! :-+
-
(https://www.richis-lab.de/images/led/14x01.jpg)
Here you can see the transmitter module of the Motorola Optobus system (https://www.richis-lab.de/transceiver03.htm (https://www.richis-lab.de/transceiver03.htm)). It has already been soldered from the pcb and then was reattached with hot glue to keep the optical impression to some extent. The housing is made of a translucent polymer and has six pins on both sides.
(https://www.richis-lab.de/images/led/14x02.jpg)
As the IEEE article "A Low-Cost High-Performance Optical Interconnect" clearly shows, the laser diodes are located outside the housing on the rear surface. The design does not seem optimal for power dissipating. However, the IEEE article describes that this disadvantage is not too great. The semiconductor material conducts heat relatively poorly, which is why the heat dissipation via the contacts is much more relevant.
(https://www.richis-lab.de/images/led/14x06.jpg)
(https://www.richis-lab.de/images/led/14x07.jpg)
In fact, the laser array is not one module, but two elements. The semiconductors are already badly damaged. In case of the receiver module, you can see that this area was originally protected with a silicone gel. Here, only the dirty remains of this gel are still visible.
(https://www.richis-lab.de/images/led/14x08.jpg)
There are two holes on the front. They serve to align the plug-in system. In addition, a fine structure can be seen running through the housing from left to right. This is a different polymer with a different refractive index that serves as a light guide within the housing material. As described in the context of the Optobus transceiver, the interface consists of ten optical fibres. The structures leading to the edge of the housing are probably auxiliary structures that were necessary during manufacture.
(https://www.richis-lab.de/images/led/14x09.jpg)
The light guides are about 40µm high. They are about 50µm wide at the top and widen to 80µm at the bottom. The distance between the light guides is 0,25mm.
(https://www.richis-lab.de/images/led/14x04.jpg)
The lead frame, which provides the electrical connection, shines through the housing material. The ten control lines can be seen there. In the area of the lasers, the ground connection is located a little lower.
(https://www.richis-lab.de/images/led/14x05.jpg)
The IEEE articles about the Optobus sometimes show optically different transmitter modules. In some pictures there are protruding pins instead of holes. There also seem to have been alternatives for the electrical connection. Probably the construction was adapted during the development. On the right you can see a lead frame for the transmitter module.
(Left: "OPTOBUS I: Performance of a 4 Gb/s Optical Interconnect" Middle and right: "OPTOBUS I: A Production Parallel Fiber Optical Interconnect")
(https://www.richis-lab.de/images/led/14x10.jpg)
(https://www.richis-lab.de/images/led/14x11.jpg)
If you remove the laser arrays, you can see that the electrical contacts are above and below the light guides. At the bottom left, one of the contact elements that make the connections between the polymer housing and the die has been left behind.
(https://www.richis-lab.de/images/led/14x12.jpg)
(https://www.richis-lab.de/images/led/14x13.jpg)
The dimensions of the two laser modules are 1,25mm x 0,55mm each. The silicone gel is difficult to remove from the small elements.
(https://www.richis-lab.de/images/led/14x14.jpg)
The lasers are so-called surface emitters, VCSELs. In contrast to the edge emitters, the laser light is emitted upwards from the die. The small hole with a diameter of about 8µm represents the optical window of the laser. The IEEE article "Characteristics of VCSEL Arrays for Parallel Optical Interconnects" describes that the diameter of the laser structure is 10µm and the electrical contacting leads to a slightly smaller optical window.
The laser diodes are designed to emit between 0,6mW and 1,2mW at 30°C ambient temperature. The wavelength of the emitted light is 850nm.
(https://www.richis-lab.de/images/led/14x03.jpg)
The IEEE article "A Low-Cost High-Performance Optical Interconnect" shows the characteristic curve of the lasers. At a current of 0,8mA the laser effect sets in and the light output rises steeply.
https://www.richis-lab.de/Opto21.htm (https://www.richis-lab.de/Opto21.htm)
:-/O
-
(https://www.richis-lab.de/images/opto/05x01.jpg)
Here you can see the receiver module of the Optobus system from Motorola. The housing is constructed in exactly the same way as the associated transmitter module. It consists of a translucent polymer and has six pins on both sides.
(https://www.richis-lab.de/images/opto/05x02.jpg)
The photodiode array itself is located on the back of the housing. It is protected against environmental influences with a silicone gel.
(https://www.richis-lab.de/images/opto/05x03.jpg)
As with the associated transmitter module, there is a second polymer with a different refractive index in the housing material that represents the light guides.
(https://www.richis-lab.de/images/opto/05x04.jpg)
In case of the transmitter module, the light guides were 40µm high, 50µm wide at the top edge and 80µm wide at the bottom edge. Here, the light guides are 90µm high and 90µm to 130µm wide. The IEEE article "Parallel Optical Interconnects Using VCSELs" explains that increasing the cross-section from the transmitting module through the fiber optic line to the receiving module reduces losses.
In contrast to the transmitting module, the receiving module in addition has a round element with a diameter of 10µm inside the light guides. Perhaps this is intended to suppress certain modes.
(https://www.richis-lab.de/images/opto/05x11.jpg)
With a slightly different illumination, it seems like the ends of the light guides are somewhat smoother than the rest of the surface.
(https://www.richis-lab.de/images/opto/05x05.jpg)
The lead frame appears to be of the same design on both the transmitter and receiver. Two times wires lead to the rear surface of the housing. Two pins conduct the reference potential to the rear surface in a second plane.
(https://www.richis-lab.de/images/opto/05x06.jpg)
(https://www.richis-lab.de/images/opto/05x07.jpg)
At the rear end of the housing, the ten light guides terminate between a ground strip and the ten contacts for forwarding the signals of the photodiodes.
(https://www.richis-lab.de/images/opto/05x08.jpg)
The larger cross-section of the light guides compared to the transmitter module is clearly visible.
(https://www.richis-lab.de/images/opto/05x09.jpg)
(https://www.richis-lab.de/images/opto/05x10.jpg)
On the back of the housing, the small round element in the center of the square light guides is no longer visible.
(https://www.richis-lab.de/images/opto/05x12.jpg)
The photodiode array consists of two elements. The dimensions are 1,2mm x 0,6mm each.
(https://www.richis-lab.de/images/opto/05x13.jpg)
(https://www.richis-lab.de/images/opto/05x14.jpg)
The silicone gel is difficult to remove. The photodiodes are shown as square elements. The IEEE article "OPTOBUS I: Performance of a 4 Gb/s Optical Interconnect" describes that the photodiodes are GaAs PIN photodiodes. Their sensitivity is given as 0.45A/W.
https://www.richis-lab.de/Opto22.htm (https://www.richis-lab.de/Opto22.htm)
:-/O
-
(https://www.richis-lab.de/images/opto/06x01.jpg)
(https://www.richis-lab.de/images/opto/06x02.jpg)
(https://www.richis-lab.de/images/opto/06x03.jpg)
The TSL230 is a light to frequency converter from Texas Instruments. The device generates a clock signal whose frequency is proportional to the illumination intensity. A transparent housing material was used so that the light can penetrate to the circuit. It allows a clear view of the lead frame, the integrated circuit and the bondwires. The marking is on the underside of the housing.
(https://www.richis-lab.de/images/opto/06x04.jpg)
The datasheet shows the configurability of the TSL230. The sensitivity can be set via pins S0/S1. In the least sensitive setting, the device outputs a frequency of 1kHz at an illuminance of 100µW/cm². The maximum clock is 1MHz. The sensitivity can be increased by a factor of 100. In addition, the frequency can be divided down via pins S2/S3.
(https://www.richis-lab.de/images/opto/06x05.jpg)
(https://www.richis-lab.de/images/opto/06x06.jpg)
A matrix with 10x10 square photodiodes occupies a large part of the dies' surface. A metal layer protects the surrounding circuit against light, which could lead to unwanted and uncontrollable failure states.
There are five testpads on the left edge. It´s possible that some kind of tuning is done through this pads. If you assign the bondpads to their functions, you can guess the push-pull output stage in the lower left corner. The line-shaped structures on the right edge indicate that standard cell logic is located there.
(https://www.richis-lab.de/images/opto/06x07.jpg)
E0C231B appears to be an internal designation of the component. The copyright refers to the year 1993.
(https://www.richis-lab.de/images/opto/06x08.jpg)
The photodiodes show their maximum sensitivity in the wavelength range between 750nm and 800nm. Towards longer wavelengths the sensitivity drops very sharply. At 1100nm the TSL230 no longer reacts at all. At 400nm the sensitivity is still 40%. This behaviour is typical for silicon-based photodiodes.
https://www.richis-lab.de/Opto23.htm (https://www.richis-lab.de/Opto23.htm)
:-/O
-
I have a damaged DFB laser with 100 mW optical power. The main feature is the ability to tune the laser wavelength by temperature or current.
Photos were taken on a phone :(
-
+
-
+
-
+
-
Most of the elements are installed on a small board. It is most likely ceramic to increase heat dissipation. About 2 W of energy enters the laser and only 0.1 W comes out. The rest goes through the board to the Peltier element located below.
I don’t know what kind of cube is specially marked with a question mark. Most likely this is some kind of focusing system. But I don’t know what kind of material this is and how it works.
-
I don’t know what kind of cube is specially marked with a question mark. Most likely this is some kind of focusing system. But I don’t know what kind of material this is and how it works.
It's an optical isolator that works by faraday rotation, the square in the outside is a magnet.
-
Today was not a good day :(
Here's a new laser.
-
.
-
.
-
(https://www.richis-lab.de/images/led/15x01.jpg)
The American company Intense develops semiconductor lasers. The module shown here with the name 1050 is the most powerful laser from the 1000 product family. At 2V and 6,5A, the module delivers a wavelength of 808nm with an optical power of 5W. The so-called HHL housing has its optical window on the top.
(https://www.richis-lab.de/images/led/15x02.jpg)
Thanks to the relatively large window in the housing, you can already see quite a lot of the internal structure.
(https://www.richis-lab.de/images/led/15x03.jpg)
The cover is welded to the housing. If you grind the edges until the lid is loose, you will see a step on the underside. This step could have served as a positioning aid for the lid.
(https://www.richis-lab.de/images/led/15x04.jpg)
The optical window appears to have been attached to the lid with solder. A round structure can be seen on the inside. This could be a coating that optimizes the optical properties.
(https://www.richis-lab.de/images/led/15x06.jpg)
(https://www.richis-lab.de/images/led/15x05.jpg)
A large part of the housing volume is taken up by a metal block.The metal block represents a large thermal capacity and thus dampens temperature fluctuations. With laser diodes, it is important to keep the temperature as constant as possible. Temperature fluctuations influence the efficiency and the wavelength of the emitted light. The metal cuboid also serves as a heat spreader and thus improves heat dissipation to the backside of the housing.
On closer inspection, you can see that there are two elements. A much flatter carrier is soldered onto a larger cuboid. There is a spacer in the right-hand gap between the cuboid and the housing.
A line is engraved on the surface of the carrier. A circle is engraved on the small metal element that ultimately carries the laser diode. Both structures are most likely used to align the laser correctly.
(https://www.richis-lab.de/images/led/15x07.jpg)
Only three of the nine pins are connected. One pin supplies the laser diode, one pin contacts the metal block and thus serves as a return conductor. The third pin is connected directly to the housing. The other pins are required if active cooling is integrated into the housing, as is the case with the VQ150 (https://www.richis-lab.de/Opto17.htm (https://www.richis-lab.de/Opto17.htm)).
(https://www.richis-lab.de/images/led/15x08.jpg)
The relatively large laser diode and a ceramic plate, which serves as a contact surface, are located on the small metal block. To transmit the maximum current of 6,5A, twelve bondwires connect the two plates.
(https://www.richis-lab.de/images/led/15x09.jpg)
(https://www.richis-lab.de/images/led/15x10.jpg)
The laser diode is 1,00 mm wide and 0,10 mm high. The beam exit is polished bright.
https://www.richis-lab.de/Opto24.htm (https://www.richis-lab.de/Opto24.htm)
:-/O
-
(https://www.richis-lab.de/images/led/16x01.jpg)
Here you can see a laser module manufactured by Siemens. It is designed to couple a light output of up to 10mW with a wavelength of 1330nm into a glass fiber.
(https://www.richis-lab.de/images/led/16x02.jpg)
The optical window allows a view inside the package. The structures that can be seen there appear unusual for a laser diode at first glance.
(https://www.richis-lab.de/images/led/16x04.jpg)
(https://www.richis-lab.de/images/led/16x03.jpg)
(https://www.richis-lab.de/images/led/16x09.jpg)
If you open the package, it becomes clear what the top element is. The strip is a carrier for a lens that improves the coupling of the laser light into the glass fiber. A similar element is connected directly to the glass fiber in the IR-LED VQ130 (https://www.richis-lab.de/Opto16.htm#Linse (https://www.richis-lab.de/Opto16.htm#Linse)). The actual laser diode is located under the lens and a photodiode is placed underneath, which makes it possible to determine the current light output. In contrast to the low-cost laser module (https://www.richis-lab.de/Opto20.htm (https://www.richis-lab.de/Opto20.htm)), the photodiode is insulated from the housing with a ceramic carrier.
(https://www.richis-lab.de/images/led/16x05.jpg)
(https://www.richis-lab.de/images/led/16x06.jpg)
The carrier of the lens appears to be made of silicon. The square through which the laser beam emerges has an edge length of 0,27 mm.
(https://www.richis-lab.de/images/led/16x07.jpg)
The lens carrier is attached to the protruding element of the package with a transparent block, which also carries the laser diode. The distance between the lens and the laser diode is just 30µm.
(https://www.richis-lab.de/images/led/16x08.jpg)
The lens has a diameter of 0,5 mm and was inserted from below into an indentation in the carrier.
(https://www.richis-lab.de/images/led/16x10.jpg)
(https://www.richis-lab.de/images/led/16x11.jpg)
The laser diode is a typical edge emitter. It is located on a carrier and has an edge length of 0,3 mm. The laser diode in the low-cost laser module (https://www.richis-lab.de/Opto20.htm (https://www.richis-lab.de/Opto20.htm)) has a smooth surface and generates the laser beam on the underside. The laser diode shown here is more similar to the laser diodes in the Kyocera 910-00011-IT (https://www.richis-lab.de/Opto14.htm (https://www.richis-lab.de/Opto14.htm)), where the laser channel is visible on the upper side. It is a 40µm wide structure. At higher currents, as in the Kyocera module, the current is usually supplied and drained via the metal layer. In this case, the metal layer only represents one potential of the supply voltage and the circuit is closed via the substrate.
(https://www.richis-lab.de/images/led/16x14.jpg)
(https://www.richis-lab.de/images/led/16x12.jpg)
While the sides of the laser diode have broken edges, the front is polished so that the laser light can escape as efficiently as possible. This is clearly evident when compared to the surface structure of the carrier.
(https://www.richis-lab.de/images/led/16x13.jpg)
The lower side of the laser diode is difficult to image. It appears to be very smooth, which is only logical as it is the second reflective surface of the laser. In the area of the laser structures, a bright layer extends beyond the edge. It remains unclear what the purpose of this layer is.
(https://www.richis-lab.de/images/led/16x15.jpg)
(https://www.richis-lab.de/images/led/16x16.jpg)
A small part of the laser light leaves the laser diode at the rear end and hits the photodiode placed there. The current flow through the photodiode can be used to determine the current output power of the laser.
https://www.richis-lab.de/Opto25.htm (https://www.richis-lab.de/Opto25.htm)
:-/O
-
Its strange that the photodetector is not tilted to prevent (or reduce) backreflections to the laser, which leads me to believe that the extra layer on the back side of the laser is a coated filter (like a mirror) to prevent this backreflection.
-
I think you have a point. I didn't see a tilting of the photodiode either. Perhaps they found a solution to block reflected light. :-+