Electronics Forum | Thu May 25 18:41:15 EDT 2006 | russ
How accurate is your placement machine? if it is accurate I would eval up to 25% off pad. the problem I might think you will have is errant paste or balls causing shorts if it doesn't coalesce completely. Bottom line is, if the board is good at th
Electronics Forum | Fri May 26 08:16:14 EDT 2006 | Chunks
This could be what we call a "non-problem". If your print is off slightly, yet after reflow there is no solder related defects, it should be considered OK. Move your inspector from the printer to right after the oven. This would enable them to ins
Electronics Forum | Fri May 26 09:49:34 EDT 2006 | pjc
This question cannot really be answered definitively here. There are unknowns such as your board design and solder land finish. I suggest you conduct a DoE (Design of Experiments) to determine paste print deposition X-Y-Theta tolerance for your appli
Electronics Forum | Tue May 30 16:02:04 EDT 2006 | slthomas
Do a dirty DoE...print ten boards with the worst error you think you can accept, build them up, and count print related defects. At the same time, print ten spot-on and proceed the same. If you don't have any more defects on the off-print batch show
Electronics Forum | Tue May 30 07:41:21 EDT 2006 | davef
Aspect ratio: The ratio of a via�s length or depth to its pre-plated diameter. So, in your case, either * 6=0.093/x, calculating x=0.093/6=0.016 as the smallest via hole diameter. ... OR * 6=y/0.01, calculating y=6*0.01=0.06 as the maximum board th
Electronics Forum | Mon May 29 23:39:11 EDT 2006 | Faizal
Can anyone advice me on the effect of SN100C wave solder on SAC305 hasl board? I suppose the silver content on the hasl pcb would leech(contaminate) into solder pot.? Would it affect the surface bonding between copper pad and the solder.?
Electronics Forum | Thu Jun 08 03:40:32 EDT 2006 | aj
Hi, I use convection reflow and both top & bottom settings are the same. Is the part too heavy to rely on surface tension? there is an equation that can determine this (aswell as real test i.e. part falling off) We have some SIM Card holders on bot
Electronics Forum | Tue Jun 27 16:05:33 EDT 2006 | grantp
Hi, Do you mean selective palettes in the wave? We are running those, and it makes the process window tight, but once we got there, it's great. Pre heating the board was a bit difficult, but we got it right, and went for a water based flux. Not sure
Electronics Forum | Fri Jun 09 11:52:59 EDT 2006 | Rob
Yes you can solder on to it - just tried it with some 0603's across some gold fingers with tin lead paste & a heat gun. Don't know how many times you could rework it though. Any chance you could get hold of an aold populated board from your custome
Electronics Forum | Wed Jun 14 11:32:44 EDT 2006 | muse95
There is an IPC test method involving a tape test, which you can try for a start. Look at the IPC TM-650 free on the IPC site. Black pad occurrences are much reduced, but I don't believe you can say they never happen, even to the better board houses
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