Mini Blog: IMDES Vapour Phase Purchase - Jumbo.

[KL27x]

Heh. I was criticized before for calling this a fancy vegetable steamer.

You need a metal enclosure with a top that allows hot vapors to recondense and fall back in. And a thermostatic control to keep the thing from pushing too much vapor too fast, to keep most of it in the thing. Not rocket science, at all. The hard part is the construction and figuring out the right order of magnitude for your starting point on the power.

700 Euros sound completely reasonable, simply because the thing is big and heavy, and it's small demand, semi-custom production.

[mrpackethead]

Heh. I was criticized before for calling this a fancy vegetable steamer.

You need a metal enclosure with a top that allows hot vapors to recondense and fall back in. And a thermostatic control to keep the thing from pushing too much vapor too fast, to keep most of it in the thing. Not rocket science, at all.

700 Euros sound completely reasonable, simply because the thing is big and heavy, and it's small demand, semi-custom production.

Only that this was 2000Euro.  and the that did not include the freight, and its not that heavy.     But your not far off the truth. Theres not much to this. 2nd board processed, and i'm totally sold on the process its just amazing.

[KL27x]

2000 euros... nice.

I have a very nice product for small scale electronics manufactures, homebrewers. I will keep that margin in mind, if it ever gets anywhere. Seems like I just don't ever have the time. This one is very inexpensive to make and it's pretty SMALL. So I have high hopes.

[tautech]

Heh. I was criticized before for calling this a fancy vegetable steamer.

You need a metal enclosure with a top that allows hot vapors to recondense and fall back in. And a thermostatic control to keep the thing from pushing too much vapor too fast, to keep most of it in the thing. Not rocket science, at all.

700 Euros sound completely reasonable, simply because the thing is big and heavy, and it's small demand, semi-custom production.

Only that this was 2000Euro.  and the that did not include the freight, and its not that heavy.     But your not far off the truth. Theres not much to this. 2nd board processed, and i'm totally sold on the process its just amazing.

Was Galden supplied or did you have some on hand?

C'mon where's the finished PCB pics. 

[mrpackethead]

..Was Galden supplied or did you have some on hand?

I got 1000ml with it, but will order some more from Hawker Richardson.

[mrpackethead]

So, i've run 12 boards through the System today...   

The quality of the soldering is remarkable. I'm getting exceptionally clean, very well formed, joints. I'm not getting some of the issues i used to get in the Convection oven.   I've been able to do some pretty big chunky inductors next to some 0402 parts and get very consistent joints.  From that perspective this is a wonderful result. 

My galden, clearly needs cleanin now, its looking quite dirty..

However;

(1) the lid microswitch broke.. its extremely delicate.  this part is not intended for this kidn of application.     I've replaced it with something more heavy duty..

(2) the lid itself is not flat and it was not sealign properly.. Galden was escaping...  I've been able to reoslve this with a bit of silicon gasket seal. and i put a couple of blocks of aluminum on the lid to way it down.   That really helped.

(3) The mesh tray , is not that great, its not going to last, i can see its' alrady going to fall apart.

(4) Double sided was interesting, there is no provided way of dign this.. I can see i'm going to have to make somethign with some tooling holes etc to support the boards.

(5) The cooling is just way too slow.  This really lets it down.. blowing room temp air past the tank is not that effective.  And it takes too long.  THis really needs to be thought about a bit more effectively..

So, does VP work well. Yes, its wonderful,    it should bSo simple for most folks to use and its a sensible alternative to toaster ovens.  You'll get really good joints, without overheating.. 

Would i recomend this machien for any commerical process as it sits..    No.     Does it have the framework of somethign that coudl be. Yes. It just needs a bit more refinement.   I think its probalby like the first 3d printers.

[tautech]

From the Vapor phase thread Sean talked of a cooling method in this post:
https://www.eevblog.com/forum/projects/vapour-phase-soldering/msg592042/#msg592042

free_electron too:
https://www.eevblog.com/forum/projects/vapour-phase-soldering/msg592131/#msg592131

Galden contamination was first discussed here:
https://www.eevblog.com/forum/projects/vapour-phase-soldering/msg592189/#msg592189

[mrpackethead]

On the "loss" of galden,

I have processed 25 panels in the machine.. I put 500mL of Galden in it, to start with which put it up to about 3.5m in the tank..    after processing the 25 panels, i've needed to add 100ml of addtional fluid to bring it back to close to that level.

I've been doing some reading, and i suspect that Galden coudl be quite hydroscopic, so some of the "vapour" i saw escaping was not actually galden, but plain old steam.     This is reinforced by the fact that after a couple of cycles on a day, there was no escaping vapour.     However the next day ( after a 12 hour cold state ),  the first run i got, it was steam again..  i suspect it sucks some water vapour in...   

My best bet on the loss is actually that some of the fluid is condencing on the boards them selves, and i'm taking it out of the tank, on the boards themselves.  Much of this i think could be solved by a tented lid, as quite a bit of it, is drops forming on the lid condensing and dropping back on my panels.

The process time is slow.. With two panels running in the machine, my cycle time was between 25 and 29 minutes..   Most of it, with the materials stting under 80C,  so its not damaging them, but its too hot to touch...

After a weeks use, i'm 100% sold on the process,  this implementation is just poor and needs work

[wraper]

After using it for about 8 months, I came to the conclusion. Controller needs to be reprogrammed if possible, or replaced. Otherwise using it happens to be quiet troublesome. All controller does, is switches off the heating once PCBs are reflowed, an all of the time before that, it heats with the max possible power, therefore a huge issue arises. The freaking component tombstoning, the main concern with vapor phase soldering happening because of the too rapid temperature rise, and which wasn't taken into account while designing this oven. On many panels, I need to rework as much as 2-3% of the SMD components, and that after tweaking solder paste amount. Perfect panels are lucky exceptions. I found a workaround, once it reaches around 60^oC on the display, turn it off, wait like 5 minutes, switch it on again (displayed temp will be >100^oC), and turn on the cycle. More likely than not, reflowed panel will be perfect. So by avoiding such rapid rise of the temperature, and ensuring that boards get preheated, the issue is mostly eliminated. So to properly to fix the issue, oven needs to regulate heating speed by itself, not me running circles around it.

[wraper]

Another issue is galden condensating on the lid, and then dropping on the board, making it covered in galden. I wipe the lid before every reflow, but the issue still exists, although reduced. Now every few reflows I'm covering the lid with a silicone release spray, which prevents large drops from forming. Therefore they usually stay on the lid without dropping, but still not perfect. So I think that some descend need to be made, to ensure galden flowing to the side, where it can safely drop, and not staying on the lid waiting to drop in the middle.

[mrpackethead]

Yes, hugely dissapoitning that it works this way.   Its not good that it does work this way.  Though a small amount of work will fix this, and make it work.
Disscussed this with marc, and he is working on somethign. but i dont' have time to do that.

[wraper]

I can officially confirm that a man who designed this oven is a retard. Not only all of the logic is made on 3 relays + 3x 2N930 in TO-18 for some stupid reason, controller basically only shows the temperature, and changes output state once set temperature is reached. But he also put 230V mains voltage between 2 pins of the 2.5 mm pin pitch connector,  with very large annular rings used.

[wraper]

Turns out that temperature controller is a dangerous piece of crap as well. All would be fine and dandy except in one place there is less than 1mm between primary and secondary side  .

[ovnr]

Haha, that's atrocious.

Out of curiosity, how does the vapor phase reflow process deal with flux? I imagine some of the vapor condenses on the boards - does it mix with the liquid flux and cause a mess? Do the boards come out cleaner than after a normal reflow oven cycle?

I wouldn't mind having an unit, but €2000 is so hilariously much more expensive than a €30 toaster oven that I'm not even considering it. Especially when the toaster oven is better made.

[wraper]

Haha, that's atrocious.

Out of curiosity, how does the vapor phase reflow process deal with flux? I imagine some of the vapor condenses on the boards - does it mix with the liquid flux and cause a mess? Do the boards come out cleaner than after a normal reflow oven cycle?

Some flux is left on the board, the rest of it goes away with Galden and condensates on the walls. No mess on the board. My oven is smaller one, so I paid around EUR 700, for EUR 2000 (bigger version) it would be extremely insane. Here is my own bare bones controller I slapped together (based on the board completely not meant for this  ). Spent a lot of time to tune the thing because RTD sensor is located extremely bad so don't represent actual temp on the board reflowed.

[Koen]

I wouldn't mind having an unit, but €2000 is so hilariously much more expensive than a €30 toaster oven that I'm not even considering it. Especially when the toaster oven is better made.

I use vapour phase to avoid problems with thin plastic connectors and only bought a 20€ "asparagus cooking pot", 100ml of Galden and a thermometer. It made my life much easier than the oven.

[wraper]

much more expensive than a €30 toaster oven that I'm not even considering it. Especially when the toaster oven is better made.

Toaster oven does not work well for large boards, and completely sucks for panels. It will have problems to reflow some areas while other areas will be already overheated. And if there are some connectors with high thermal mass and shiny surface, which will reflect IR, like HDMI, it is a guaranteed disaster.

[mrpackethead]

Haha, that's atrocious.

Out of curiosity, how does the vapor phase reflow process deal with flux? I imagine some of the vapor condenses on the boards - does it mix with the liquid flux and cause a mess? Do the boards come out cleaner than after a normal reflow oven cycle?

The boards come out extremely clean.  and you have very well formed solder joints.  Far superior to what you'll get in a toaster oven.   Its easier to get more consistent results...  However this is let down by;

(a) extremely poor build quality - both design and implmentation. theres multiple safety issues.
(b) the lack of adhering to a profile. 
(c) the lack of a 'tented lid.
(d) the lack of proper rails to hold panels..

I wouldn't mind having an unit, but €2000 is so hilariously much more expensive than a €30 toaster oven that I'm not even considering it. Especially when the toaster oven is better made.

Realisitcally  what i have is worth about 300 Euro..

[wraper]

So I reflowed a few panels with my new crappy controller installed and here are results. Tombstoning reduced to minumum, almost none, probably could reduce to zero with finer tuning. Even if solder paste was applied with a big offset, completely no solder bridges on 0.5mm pin pitch components  , unlike before. SMD parts which were not precisely placed better align to the pads, and solder joints look a tad better too. Less Galden escaping while reflowing and condensating on the lid. And that's with just a crappy controller I started making yesterday evening. I don't even have a schematic of what I made, just slapped some parts together and wrote a very simple firmware, $2 worth of parts. Stupid IMDES, could not make such a simple thing.

[tautech]

So I reflowed a few panels with my new crappy controller installed and here are results. Tombstoning reduced to minumum, almost none, probably could reduce to zero with finer tuning. Even if solder paste was applied with a big offset, completely no solder bridges on 0.5mm pin pitch components  , unlike before. SMD parts which were not precisely placed better align to the pads, and solder joints look a tad better too. Less Galden escaping while reflowing and condensating on the lid. And that's with just a crappy controller I started making yesterday evening. I don't even have a schematic of what I made, just slapped some parts together and wrote a very simple firmware, $2 worth of parts. Stupid IMDES, could not make such a simple thing.

Controller schematic by wraper......

[mrpackethead]

So I reflowed a few panels with my new crappy controller installed and here are results. Tombstoning reduced to minumum, almost none, probably could reduce to zero with finer tuning. Even if solder paste was applied with a big offset, completely no solder bridges on 0.5mm pin pitch components  , unlike before. SMD parts which were not precisely placed better align to the pads, and solder joints look a tad better too. Less Galden escaping while reflowing and condensating on the lid. And that's with just a crappy controller I started making yesterday evening. I don't even have a schematic of what I made, just slapped some parts together and wrote a very simple firmware, $2 worth of parts. Stupid IMDES, could not make such a simple thing.

Any chance of sharing the schemactic .. Im curious how you did it for $2.   My solution was more like $30

[wraper]

So I reflowed a few panels with my new crappy controller installed and here are results. Tombstoning reduced to minumum, almost none, probably could reduce to zero with finer tuning. Even if solder paste was applied with a big offset, completely no solder bridges on 0.5mm pin pitch components  , unlike before. SMD parts which were not precisely placed better align to the pads, and solder joints look a tad better too. Less Galden escaping while reflowing and condensating on the lid. And that's with just a crappy controller I started making yesterday evening. I don't even have a schematic of what I made, just slapped some parts together and wrote a very simple firmware, $2 worth of parts. Stupid IMDES, could not make such a simple thing.

Any chance of sharing the schemactic .. Im curious how you did it for $2.   My solution was more like $30

Well, I will need to draw it first, as there is none. If buying everything in single quantities, likely would be more like $3 in parts. Also firmware is not something of release quality  . MCU is Silicon Labs EFM8UB10F16G-C-QFN28 (even has USB, 0.5mm pin pitch), could throw in 4-8KB flash BB series instead of UB, would be cheaper (like $0.5 @ single quantity). I somewhat doubt you have programming tools for it. So I don't know if it's worth to bother to draw the schematic. Except that 2x P-channel mosfets + 2X NPN BJT to make high side 12V driver for Fans and heater relay. 78L05, cheap opamp and some resistors.

[Monkeh]

I somewhat doubt you have programming tools for it.

EFM8UB1x comes with a USB bootloader in rev C or higher, starting beginning of 2016. Most other EFM8s come with UART bootloaders. No special tools required unless you want debugging - IDE and Keil license are free.

[wraper]

I somewhat doubt you have programming tools for it.

EFM8UB1x comes with a USB bootloader in rev C or higher, starting beginning of 2016. Most other EFM8s come with UART bootloaders. No special tools required unless you want debugging - IDE and Keil license are free.

That's true, but yes, you must get 2016 week 1 or newer (mine was not), farnell has new date code (I bought hundreds of them recently, use old chips without bootloader capability for crap like this), RS stocks old B revision. For BB or others with UART bootloader, firmware would need a little bit of modification though.

[mrpackethead]

How are you interfacing the thermocouple to the microcontroller