Electronics Forum | Thu Apr 24 20:52:03 EDT 2008 | davef
Use of a hot air gun to reflow solder that passes tests [after failing those tests] seems to indicate the standard process reflow was inadequate. To understand this better, we'd want to measure temperatures at various points on the board during reflo
Electronics Forum | Thu Apr 24 21:52:18 EDT 2008 | fowlerchang
We have measured the temperature of CSP solder joint. The peak temperature is 232oC and the wetting time above 217oC is 30s. But we use leaded solder paste instead of lead free solder paste. I doubt why no crack of solder joint was observed after cr
Electronics Forum | Fri Apr 25 12:36:52 EDT 2008 | fsw
All, Does anyone on the forum have experience with underfill? We have a component with QFN pkg on one of the new products. It has a thermal pad in the centre. Customer wants this component to have an underfill. Questions - 1) Does one normally req
Electronics Forum | Fri Apr 25 14:14:48 EDT 2008 | blnorman
We just started having board warpage problems with one of our suppliers. The product has been in production for some time with no design changes, no material changes from the board supplier. Someone told me once that if the PCB cure was not corre
Electronics Forum | Tue Apr 29 11:18:16 EDT 2008 | julienvittu
basically your problems come from the copper balance top and bottom side we are using substrate down to 0.18mm (semiconductor industry/ Bga package / SIp business) you have to respect 5% difference maximum between Top and bottom side otherwise you
Electronics Forum | Wed Apr 30 07:33:12 EDT 2008 | davef
It's not acceptable to us. More importantly, you need to determine if it's acceptable to your customer. Recognize that your little IPA scrub does NOT remove the OA flux residues from the board. It mearly spreads them out across the board and under c
Electronics Forum | Wed Apr 30 07:48:37 EDT 2008 | realchunks
If your pots are open you then just need to dry them. Don't hide them. Are they rated for water clean? If not hand solder after cleaning with no-clean wire. Hand cleaning with IPA is dangerous - you really just push the flux around and don't was
Electronics Forum | Tue Apr 29 09:40:07 EDT 2008 | nitro
It may be a voltage issue. A very slight variance in voltage can cause this. I have seen it before with one of our machines. I think the 5vdc. was dropping out just a little bit. Turned out to be a bad muffin fan. Power supply was getting warm, 5vdc.
Electronics Forum | Tue Apr 29 11:18:16 EDT 2008 | bandjwet
All: I am interested in how process engineers are both removing and adding markings to active devices. We have a job where we have to both remove the markings of and the re-mark SOICs. The markings on the devices look like they are pad or ink jet p
Electronics Forum | Thu May 01 16:41:54 EDT 2008 | chrisawallace
At my last company, we sent specific key components out for remarking to help protect our intellectual property as it is much more difficult to copy a design if you don't know what the components are. (Yes, I understand this is not foolproof but rath
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