Make a cool case out of PCB only

[electrodacus]

great design!
What software did you use to make the animated gif/3D model/PCB layout?

Thanks,
For the 3D renders I used Blender 3D is a free software tool.
Animated gif is made out of still 3D renders from Blender 3D using GIMP another free software tool. I think both are available for Windows but I use them in Linux.
You should check out this video since that gif animation was done for kickstarter so no real render just viewport snapshots and gif is limited to 256cloors anyway

[gbrettell]

Very innovative ... great work!

[electrodacus]

Very innovative ... great work!

Thanks.

[cdev]

Interesting, out of curiosity is pin that dissipates heat. Are they electrically connected to the aluminum or does it go though some kinda insulator in the pcb..?

Hi the way metal core PCB is build is like this. A 2.5mm Aluminium plate in my case then a 0.1mm layer of Teflon and then your copper layer so no electrical contact between your pads and aluminium plate but a really good thermal transfer do to that thin 100um layer of Teflon.
I hope more people to find about this and work with this.

PFOA is toxic if its heated above certain temperatures. Its also (I think) an endocrine disruptor

http://www.ncbi.nlm.nih.gov/pubmed/?term=pfoa

[electrodacus]

Interesting, out of curiosity is pin that dissipates heat. Are they electrically connected to the aluminum or does it go though some kinda insulator in the pcb..?

Hi the way metal core PCB is build is like this. A 2.5mm Aluminium plate in my case then a 0.1mm layer of Teflon and then your copper layer so no electrical contact between your pads and aluminium plate but a really good thermal transfer do to that thin 100um layer of Teflon.
I hope more people to find about this and work with this.

PFOA is toxic if its heated above certain temperatures. Its also (I think) an endocrine disruptor

http://www.ncbi.nlm.nih.gov/pubmed/?term=pfoa

You will nor get to those temperature in normal operation unless some components decide to exhale magic smoke and Teflon itself is not suspected of causing cancer PFOA is used in the process of making Teflon
FR4 may be even worse above some temperatures so you should not buy any electronics

[Wilksey]

I've just seen this on Julian Iletts YT channel, or a similar model anyways!  Good job!

[electrodacus]

I've just seen this on Julian Iletts YT channel, or a similar model anyways!  Good job!

Yes this is the same model the new model is just 3D render as of now. That one will probably look way better in real life.

[asuperpower]

wow, that is really well executed! 

[electrodacus]

wow, that is really well executed! 

Thanks. I will have posted this here earlier if I knew people find it so interesting.

[Psi]

Anyone got a recommendation for a company that you can send gerbers too and they will produce pretty much the same thing as a PCB with holes, silkscreen and stuff, but no copper tracks and maybe not even FR4.

I'm looking for somewhere cheaper than a PCB house to get boards made that are to be used for cases and front panels. ie, non electronic uses.

[electrodacus]

Anyone got a recommendation for a company that you can send gerbers too and they will project pretty much the same thing as a PCB with holes, silkscreen and stuff, but no copper tracks and maybe not even FR4.

I'm looking for somewhere cheaper than a PCB house to get boards made that are to be used for cases and front panels. ie, non electronic uses.

If you are not interested in the FR4 and temperature resistance there are those that do 2D shapes out of acrylic or similar plastic sheets (I'm sure they can convert Gerber in to SVG or whatever they use).
Like you seen my spacers are just simple FR4 no copper and they where not that expensive but they do not take much material since they are small and L shaped so can be optimised with not much material loss. 

[Mikey]

Genius! Except you made me spend all day thinking about a project where I could do something similar.

[electrodacus]

Genius! Except you made me spend all day thinking about a project where I could do something similar.

[Bexley Talbot]

That's pretty beast 

[3roomlab]

may i pick your brain about that direct-FET i see on the PCB?

[electrodacus]

may i pick your brain about that direct-FET i see on the PCB?

Yes ask your question
I will not be using that in my next design I will be using the one you see next to those direct-FET the IPT007N06N much better value.
The problem with direct-FET is that PCB trace from the Source can not be wide enough so the loss there will make the small RDSon of the FET quite useless.

[senso]

Maybe some via stitching and another trace on the other layer to help lower the resistance of the trace?

[electrodacus]

Maybe some via stitching and another trace on the other layer to help lower the resistance of the trace?

If you look closely I use a single layer metal core PCB so no via are possible. But I can also do 80A with just 35um (1Oz) of copper because of excellent thermal performance of the metal core PCB.
The solder points are also quite small on the direct-FET when you are working with 1.1mohm RDSon FET PCB resistance plays a huge role and can cancel all the advantage of a low RDSon FET.
The IPT007N06N is probably the best in the world at this moment with max 0.75mohm and measured typical of 0.66mohm also do to case construction it works way better on a single layer PCB.
The direct FET just dose not work in my application. I used those at up to 40A in that configuration and that was really the limit and did not liked the performance.
That short trace connecting the Source of both mosfets together doubles the loss.   

[eneuro]

But I can also do 80A with just 35um (1Oz) of copper because of excellent thermal performance of the metal core PCB.
...
The IPT007N06N is probably the best in the world at this moment with max 0.75mohm and measured typical of 0.66mohm also do to case construction it works way better on a single layer PCB.

When looked into its datasheet while I might be interested in using this Datasheet IPT007N06N - Infineon and calculated contact area under dren (~50mm2) and source (~15mm2) it looks like this under dren is ~3.3 times bigger than under source, but on PCB with 35um copper layer when we take contour of IPT007N06N dren (7.5mm x 7mm ) contact area (there is no other way for current to flow if there is no via stitching possible in your smart design) than we find that this contour is ~29 mm long, so multiply by 1oz copper width we get 29mm*0.0347mm= 1mm2 pf cross section copper thin layer for 100A ?
Do you plan use few of those "best in the world" IPT007N06N in parallel on this 1oz PCB?
Else I smell "magic smoke" and IPT007N06N desoldered itself surfing over teflon surface on hot aluminium base 

[electrodacus]

But I can also do 80A with just 35um (1Oz) of copper because of excellent thermal performance of the metal core PCB.
...
The IPT007N06N is probably the best in the world at this moment with max 0.75mohm and measured typical of 0.66mohm also do to case construction it works way better on a single layer PCB.

When looked into its datasheet while I might be interested in using this Datasheet IPT007N06N - Infineon and calculated contact area under dren (~50mm2) and source (~15mm2) it looks like this under dren is ~3.3 times bigger than under source, but on PCB with 35um copper layer when we take contour of IPT007N06N dren (7.5mm x 7mm ) contact area (there is no other way for current to flow if there is no via stitching possible in your smart design) than we find that this contour is ~29 mm long, so multiply by 1oz copper width we get 29mm*0.0347mm= 1mm2 pf cross section copper thin layer for 100A ?
Do you plan use few of those "best in the world" IPT007N06N in parallel on this 1oz PCB?
Else I smell "magic smoke" and IPT007N06N desoldered itself surfing over teflon surface on hot aluminium base 

I have one SBMS4080 powering this computer The SBMS4080 has a single IPT007N06N for the output (max output current 80A) here is a photo with SBMS4080 outputting 77.8A while also having at the input 26A (that is with the direct FET)
This is mounted on a metal core PCB quite different form a normal FR4 the trace will not usually get more than 3 to 4C above aluminium plate since all there is between the two is a 100um of Teflon.
While at above 75A for over 20 minutes the heat sink temperature was under 40C absolutely no problem with the design.
The new SBMS100 will be able to handle 120A (overcurrent protection limit) with two of this IPT007N06N in parallel and 3Oz (100um) copper almost no length to copper trace with the new design at most 5mm distance between power components.
While handling 100A nominal in and 100A out so 200A total with 6 IPT007N06N the entire SBMS TDP will be 22W easy to dissipate with a small passive heat-sink.
I know any PCB trace calculator will be on the red with this values but metal core PCB is quite a different class.
The SBMS4080 has already some months used to power my house and with normally 50 to 60A on Load for one or two hours during the day that 77.8A is not that often I do not like to stress my LiFePO4 batteries. 

[eneuro]

While at above 75A for over 20 minutes the heat sink temperature was under 40C absolutely no problem with the design.

Did you checked temperature  of IPT007N06N itself? For short period of time at low ambient temperature with huge thermal capacity maybe it works.
Anyway 75A for this IPT007N06N is of course nothing and ~4W loses easy to disipate, but  1mm2 of copper in best case scenario for huge currents looks bad and I do not like it at all.
This is not PCB calculator, just raw math and physics  based on physical dimensions of IPT007N06N and copper layer
Probably additional copper plate (1mm) cut on CNC, on top of regular PCB, under  IPT007N06N or a few other low RDSON in parallel will do the job much better.
IPT007N06N is quite expensive, so we can buy many low RDSON's  for the same price.

BTW: 25A fused home grid 230VAC with 2.5mm2 wires we have 10A/mm2 and ~6kW , so for 100A a lot of copper lost for wiring the house with such low voltage high power outputs and very difficult to transfer this energy for longer distances, so such low voltages are good for.... welding   

[tszaboo]

To be honest I find interesting, that you would use such big mosfet in your design. As far as I understand you are not switching it at high frequency, because it works like a chopper, so gate capacitance and switching losses are less significant. In my designs, where I have to do similar tasks, I usually use multiple smaller fet in parallel. For that 6 dollar Infineon, you could get 8-10 Power SO8 FET, which can switch much higher current, you just have to make sure that you know how to parallel FETs. Not to mention, because you use higher quantities, you get a lot better discounts at the suppliers.

[electrodacus]

While at above 75A for over 20 minutes the heat sink temperature was under 40C absolutely no problem with the design.

Did you checked temperature  of IPT007N06N itself? For short period of time at low ambient temperature with huge thermal capacity maybe it works.
Anyway 75A for this IPT007N06N is of course nothing and ~4W loses easy to disipate, but  1mm2 of copper in best case scenario for huge currents looks bad and I do not like it at all.
This is not PCB calculator, just raw math and physics  based on physical dimensions of IPT007N06N and copper layer
Probably additional copper plate (1mm) cut on CNC, on top of regular PCB, under  IPT007N06N or a few other low RDSON in parallel will do the job much better.
IPT007N06N is quite expensive, so we can buy many low RDSON's  for the same price.

BTW: 25A fused home grid 230VAC with 2.5mm2 wires we have 10A/mm2 and ~6kW , so for 100A a lot of copper lost for wiring the house with such low voltage high power outputs and very difficult to transfer this energy for longer distances, so such low voltages are good for.... welding   

The worst case scenario is a few hundred ms for the overcurrent protection to act or a few hundred microseconds in case of short circuit currents.
The entire Load circuit includes the IPT007N06N a 0.25mohm current shunt resistor  (two 0.5mohm in parallel each rated at 3W) the copper trace and connectors. All this together have a 2mohm measured resistance or 2mV/A voltage drop.
At full 80A the total voltage drop is 160mV so 12.8W total that need to be dissipated. All this Load circuit uses a total footprint of about 40x40mm on the metal core PCB but the metal core PCB is 121mm x 87mm and gets mounted on a heat-sink able to dissipate at least the 20 to 22W worst case TDP.
As you already made the calculation out of this 12.8W about 4 to 4.8W will drop on the IPT007N06N then 1.6W on the current shunt resistors (0.8W each) the rest of the loss is on the PCB trace and connectors so about 6.4W and all this uses quite a bit of surface on the metal core PCB that is as I mentioned before made out of 2.5mm Aluminium plate and just 100um of Teflon.
The thermal performance of the metal core PCB is around  0.13°C cm^2/W to  0.5°C cm^2/W  (I took the worst case value since you do not know exactly what you get from a PCB manufacturer in China ) so you can see that the temperature delta between the heatsink and copper trace and components is really small at most a few single digit °C above heatsink temperature.

[electrodacus]

To be honest I find interesting, that you would use such big mosfet in your design. As far as I understand you are not switching it at high frequency, because it works like a chopper, so gate capacitance and switching losses are less significant. In my designs, where I have to do similar tasks, I usually use multiple smaller fet in parallel. For that 6 dollar Infineon, you could get 8-10 Power SO8 FET, which can switch much higher current, you just have to make sure that you know how to parallel FETs. Not to mention, because you use higher quantities, you get a lot better discounts at the suppliers.

What is the RDSon on those 8 or 10 SO8 also there will be longer copper traces to connect them all and if you look at my replay above that is quite significant part of the power loss.
I use the FET as a switch mostly so I'm interested in the smallest loss so small RDSon.
I did had in my initial design (just prototype) 4 smaller FET that cost almost the same while they where just 40V not 60V
Yes that discount for larger number is a good thing but I do this in low volume anyway so saving even 1$ at 100 units will save me 100$ not even worth the manual placement of all those SO8 Not to mention I have no space for more than 4x SO8 in my design.

[electrodacus]

may i pick your brain about that direct-FET i see on the PCB?

Yes ask your question
I will not be using that in my next design I will be using the one you see next to those direct-FET the IPT007N06N much better value.
The problem with direct-FET is that PCB trace from the Source can not be wide enough so the loss there will make the small RDSon of the FET quite useless.

after sleeping ... i forgot what i wanted to ask ... something about thermal dissipation 
ahhh YES ! ... at what Tcase do you approx design those power packages at? 70^oC ?
or at what Tj alternatively if thats the number you go for?

Look at the earlier replay I made to eneuro