Electronics Forum | Wed May 08 11:07:54 EDT 2002 | Carol Stirling
We have a concern with moisture absorbtion/humidity effects on PWBs specifically used for automated SMT (including BGA). I'm sure there is a IPC spec on this and would appreciate the number - I've searched the IPC web-site -no results. Could you t
Electronics Forum | Thu Jul 14 20:16:33 EDT 2005 | Bman
I know what the COB process is, and I have no intention of getting involved with that end of things. I need to know how to place SMT parts on a board with a COB. It looks like the preferred method is to place the SMT parts first, then go through th
Electronics Forum | Mon Aug 30 16:10:10 EDT 1999 | Dave F
| I have looked through the IPC web page and surfed to frustration. Can somebody give me a lead? | Brian: We don't use an etched board. We use a special stencil, described below and print on bare copper laminate. 3 Solder Wetting Test. Recogniz
Electronics Forum | Wed Jan 12 10:05:20 EST 2005 | Dreamsniper
we are using polyimide boards 6 inches x 7 inches, 2.5mm thick, 12 to 14 layers, for aerospace industries. I am using a long bake of 12 hours at 70'C prior to manufacturing or exposure to elevated reflow and wave soldering temperature. If schedule i
Electronics Forum | Sat Jan 08 08:50:35 EST 2005 | davef
Normally, you should not have to bake boards that are properly packaged and stored. Since you are seeing problems, baking makes sense. Consider 125C for 4 to 6 hours. Additionally, look here for more, while waiting for others: http://www.smtnet.
Electronics Forum | Fri Jan 07 07:36:14 EST 2005 | dansmall
I have a Polyimide board that is showing signs of de-lamination. I was wondering what pre-bake times and temperatures other people would recomend for new boards as well for boards that have been on the shelf for 8 months.
Electronics Forum | Mon Oct 29 18:21:43 EST 2001 | slthomas
We recently have received a lot of warped (bowed and/or twisted behond IPC 600 specs.) bare boards (some our fabricator's fault, some ours by design) and I can't help but figure that long term reliability will suffer when building product with them.
Electronics Forum | Fri Oct 22 11:53:53 EDT 2004 | C Lampron
Hi Christina, What would you be basing the yields off of? Is it solder defect, component placement, etc....? I have worked for a flex house for quite a few years. You are right. The Polyimide is very dimentionally unstable. (even more so on humid da
Electronics Forum | Wed May 28 19:21:09 EDT 2014 | hegemon
Just from the look of things (a picture) I would first guess it is a contamination problem on the PWB. Check over all your handling practices. Make sure the PWBs are NEVER touched by bare hands. I would not rule out the Black Pad phenomena, but i
Electronics Forum | Sun Dec 19 23:27:22 EST 1999 | Mike
Should I manufacture my own boards or outsource them? Any opinions are welcome. I own a company and sell electronic products. Some products we sell have specific ad-on circuit boards which I have designed and had manufactured just for my company. The
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