Electronics Forum | Mon Mar 13 04:18:42 EST 2006 | pedestrian
0.2mm gap between parts is small and easy to solder short. I prefer 5mils or 4mils.
Electronics Forum | Thu Mar 09 04:04:48 EST 2006 | dougs
one point to remember is to have a large stencil reduction on the thermal pad, you need to reduce the solder volume by about 35%, if you don't you risk the solder from the thermal pad shorting out the other leads or the solder volume causing the comp
Electronics Forum | Wed Mar 15 13:25:25 EST 2006 | russ
Your profile is definitely off. It could be bad leads but it sounds like your max temp is too low and the TAL is too short. By how much? Don't know.
Electronics Forum | Fri May 19 09:21:16 EDT 2006 | russ
Ken, It is much easier for this thing to leave the forum than back up its BS. I am sure we will get another Dr superstar very shortly. And a Mrs. Superstar to agree with it.
Electronics Forum | Tue May 23 14:24:25 EDT 2006 | stepheniii
Another major consideration is moisture. I saw a batch of BGA's delaminate. With the X-ray it looked like the balls were shorted. (Well they were but I mean that wasn't why the BGAs had failed.)
Electronics Forum | Tue May 30 17:56:27 EDT 2006 | slthomas
It's dust contamination. Most of the boards have loose dry dust on them but a few have what looks like a dried slurry. Either way I'm not impressed. This is the second batch, the first one had obvious *visible* shorts on boards that were alledgedly
Electronics Forum | Thu Jul 20 02:42:34 EDT 2006 | Francis
Short term, taped the gold finger. long term, study the air flow of the reflow section of the oven. It is always being overlook at this part and lookout for the printer. The air flow must be laminar and properly flowed back.
Electronics Forum | Fri Jul 21 13:42:11 EDT 2006 | Chunks
Paste too thick. Paste not aligned on pad. Part not aligned on pads. Part leads not straight. Oven profile. Paste slump from warm board. Operator before oven thinks they can place IC better than placement machine - so plays IC hockey with part. Oven
Electronics Forum | Mon Jul 24 08:30:25 EDT 2006 | nodlac
- Dirty stencil transfering paste from the stencil bottom. - Stencil opening (Pad Hole) to pad ratio incorrect - too large -misaligned stencil
Electronics Forum | Mon Jul 24 08:53:37 EDT 2006 | samir
It could be an over-zealous operator moving the IC with tweezers before reflow oven. Have a splendid day! -Samir
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