Electronics Forum | Tue May 15 21:57:06 EDT 2001 | davef
Welcome!!! Where the hay ya been??? Sorry bud, were lining-up with your fab [it hurts me to say that, but when yer ] We used to dry pack with desiccants, also. Its probably an old MIL-STD-2073-1C requirement [er something like that]. We qui
Electronics Forum | Fri Jun 18 10:59:37 EDT 1999 | Scott Cook
| A user of one of our components exceeded the floor life of some plastic BGA components. They did do a pre-bake prior to SMT reflow but only 72 hrs at 40C and not the recommended 12 hours at 125C. I've recommended accoustic microscopy to look for po
Electronics Forum | Tue Aug 26 07:44:06 EDT 2008 | davef
Industry-wide, there is no current requirement for baking of bare boards. It adds no value. * IPC-HDBK-001 has guidelines olden times. * IPC-TM-650 has several test methods to determine moisture resistance to both liquid immersion and absorption from
Electronics Forum | Fri Oct 19 09:06:00 EDT 2001 | LW
I was somewhat involved with Kermit Aguayo during his work on the SMA-void problem, as I was with one of the SMA suppliers at the time. I recall the problem being related mainly to absorption of moisture by the uncured adhesive. Some SMA formulatio
Electronics Forum | Tue Aug 13 13:50:57 EDT 2002 | ksfacinelli
A couple of years back we saw the same issue. It was when we were using a water soluble flux on a post wash assemble for a power switch. This was corrected when we switched to a no clean flux product. The appearance of the no clean products is les
Electronics Forum | Thu Jan 14 16:14:18 EST 1999 | Earl Moon
| Does anyone have any data or experience with voids in Glob Top applications? We are working with a RF application and I'm trying to find information on RF performance characteristics and moisture absorption on a glob toped devices. We have determin
Electronics Forum | Thu Oct 18 18:37:49 EDT 2001 | davef
You�re correct. Probably every supplier�s product has slightly different cure characteristics. Let me spin this up a little differently � There was a slight imbroglio in my office this morning involving a couple of stalwarts and the last Krispy Kr
Electronics Forum | Wed Oct 02 20:59:23 EDT 2002 | davef
We�ve been stewing on this and it just dawned on us the part that�s missing. Blow-holing is caused by BOTH of the following: * Moisture absorption by the resin that holds the board together. [Steve is addressing this with his various baking schemes
Electronics Forum | Thu May 26 13:28:12 EDT 2011 | blnorman
I agree with Dave on the processing issues, but there are others: Print speed capability (do you get good deposits at various print speeds), humidity exposure (our plant did get to the high side so moisture absorption on the board/stencil was an issu
Electronics Forum | Tue Jan 23 09:03:00 EST 2001 | fmonette
This guideline is actually in the IPC/JEDEC standard J-STD-033, May 1999 (although it is not spelled out very clearly, thus the current confusion in the industry). The technical reason is that moisture diffusion is a very slow process. Once parts ha
