Electronics Forum | Fri Sep 12 09:10:23 EDT 2003 | Norm Morikawa
Around 1989 I had this probelmm with a SMT CCA that would not solder in one area consistently. I had it cross sectioned by the bare board supplier and found that under their metallurgical microscope the thickness of this HASL bare board could not be
Electronics Forum | Wed Oct 01 21:22:37 EDT 2003 | ramanandkini
We have a 1.6 mm thick automotive PCB board of size 35x70mm. One of our vendor has given us a batch with lesser soldermask thickness 5~8 microns. Will this affect the circuit board on a long term. What should be standard for the soldermask thickness?
Electronics Forum | Mon Oct 13 10:30:49 EDT 2003 | markhoch
PCB is 12.25" x 4". There are large MOSFETS on the board. Two large Electrolytic Caps. Two Large Multi-Layer Ceramic Caps. 15 C Size Tantalym Caps. A fair number of IC's, (SO-8's, SO-16's). No BGA's or finepitch of any kind. The board is double sided
Electronics Forum | Tue Oct 28 09:47:50 EST 2003 | woodsmt
It is possible to use a selective wave soldering fixture to "mask" the BGA devices from the wave. Unless you have a very thick board or one that is tough to heat, you should have no problem with BGA. Of course you should run some process experime
Electronics Forum | Wed Dec 10 10:36:42 EST 2003 | russ
I would contact your PCB supplier, they usually have some type of software for panel optimization. Each shop potentially uses different size panels so it is a good idea to ask them what they are using and go from there. Keep in mind that there are
Electronics Forum | Mon Jan 19 09:49:20 EST 2004 | davef
Not as such. Choices are: 1 Cut and epoxy some board foil from your board fabricator. 2 Sacrifice part a pad repair kits from the likes of: * Engineering Lab 905-785-1982 * Circuit Technology Center 978-374-5000 * General assembly suppliers catalog
Electronics Forum | Mon Jan 26 20:17:01 EST 2004 | davef
Some temporary solder masks outgas ammonia as they cure. It's possible that the first side cured and out gassed through the grounding hole. But when the second side cured, it outgassed between the board and the coating and in so doing reacted with
Electronics Forum | Wed Jan 28 08:40:07 EST 2004 | stefwitt
Joe, it does explain and it does not. You are either an University or you do production. If you want to jump on board and teach SMT production, I would go with Dave's recommendation. The machine vendor will happily supply you with sample boards, comp
Electronics Forum | Wed Feb 18 12:32:59 EST 2004 | babe
A hot plate should do it. Since your throwing the board away a good hot plate could get you to just above reflow topside and you could remove them all at one time. To do this however the bottom side of the board would probably be damaged, but you don
Electronics Forum | Mon Mar 29 07:21:51 EST 2004 | jdumont
We are also having the same problem here. I was told earlier that it could be a problem with the solder mask during the raw board manufacturing level but then I noticed that the problem was only surfacing on boards that went through the wave. As far
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