Hello Mr. Teal,
you told in the past there was a problem with the board by mounting the asics.
What was the problem exactly? I understood the most of the tin-soldering-balls of the asic has to been flooded the holes completly or over the strip-lines?
I've only the photo in my mind which you post here. It looks a little bit there or the mask was not printed to the asic chip area to stop flooding the tin-solder over the whole strip line. In this case there is only a little bit missing of tin-solder.
I want to prevent me from this problem so maybe compensate the situation by a little bit soldering paste filled to the holes ?
Another question, as I understood in this discussions was not only the cooling of the chips is essential, also the cooling of the power chips is very essential. So it looks to me it must not be a big EVE 212 cooler needed only. Maybe a smaller is good, too but I should check that the power chips get there own heatsinks.
I plan to glue a heatsing on top and a big heatsink plate on the back for the power chip area.
I've now ordered two of the most more cheap Scythe Setsugen Rev. 2 Grafikkartenkühler VGA
https://www.google.de/images?output=search&sclient=psy-ab&q=Scythe+Setsugen+Rev.+2+Grafikkartenk%C3%BChler+VGA&gbv=1&sei=fjSHUuX_EMLItQam-oHACg&hl=de&sa=X&oi=image_result_group&ei=gDSHUr5_jcGzBsGUgOgK&ved=0CDIQsAQwhich could be buy in germany from < 22 € and plan to mount them in a way the air flow will be go through the top heatsinks of the power chips.
The heatsink itself is know to handle ~ 200 W which should be enough to cool the asics.
On the back I want to mount a heatsink as bfl did this with the little singles.
I hope it will work ;-)
But in fact, can anybod give me the mechanical dimension from the board and the holes so I can prepare/check my 19 Inch server rack case for mounting some of them? I would like to bring the case in a air conditioned server room which is only possible if I mount them in a server case as I allready did this with my knc miners ;-)
I want to calculate how much asics I can mount in one case. I think 5 should been possible but I need
clarify that.
Cheers...
Well, the pads for the ASICs are that they are what are called solder mask defined pads. The pads are holes in the solder mask, and when they go through the lead-free solder bath that creates the tinned pads. When they did this process the first time, the board house had a couple issues with the flux not getting into the holes in the mask, so the pads didn't tin properly. The staff there fixed it by manually tinning them, but that left the issues with unlevelness.
We sent that back and they fixed the problem, so the boards you get shouldn't have any issues. Even on the ones we had with some mask issues we had no problems with bridging, but the ones you will get had no missing mask.
That cooler looks like it will work, though I can't tell for sure without knowing the dimension of the contact plate. For safety it should be about 35mm square.