Electronics Forum | Mon Jul 04 14:21:14 EDT 2011 | davef
The three primary causes for bubble generation in solvent-based coatings are: * Air entrapment * Solvent flash-off * Curing the coating too quickly Tell us more about your process including: * When you first notice the bubbles * Extent of the probl
Electronics Forum | Tue Feb 08 12:39:52 EST 2000 | Ashok Dhawan
I have three questions on moisture sensitive devices: 1. What is general practice on incoming / receiving inspection of moisture sensitive devices- which boils down to mostly FPDs and BGAs ? Traditionally, FPD packs were opened only at time of use
Electronics Forum | Thu May 20 22:42:19 EDT 1999 | Dave F
| hi everybody, | We've been doing some studies on assembly of CSPs. We assembled these packages on micrivia-in-pad patterns. These are 15/13.5/11 mil pads with 6 mil design microvia, using photo/laser/plasma tech. We are seeing voids, as big as the
Electronics Forum | Mon Sep 30 09:26:04 EDT 2002 | itempea
Russ, first step would be to get IPC-7095 on BGAs. A few notes: There can be voids in solder balls, or at the solder joints to the BGA, or at the solder joints to the PCB. Various sources or reasons can be responsible for these voids. Voids can be
Electronics Forum | Fri Jul 13 18:25:09 EDT 2007 | seankim10
It sounds like more has to do with plating. you may also check out the voiding issue especially if you have new FAB or the supplier. I had problems with a RF chip in QFN package due to insufficient grounding that voiding caused. This ground is often
Electronics Forum | Fri Nov 02 12:01:26 EST 2001 | mparker
I have two cases where I must bake after DI wash. The moisture entrapment is specifically within microprocessor sockets. Without air gun blow out and baking, oxidation occurs that causes flaky contacts for the PGA. We will bake for 2-3 hours @ 60C. O
Electronics Forum | Wed Feb 09 21:33:32 EST 2000 | Dave F
Ashok: I have three answers to your questions on moisture sensitive devices: 1. What is general practice on incoming / receiving inspection of moisture sensitive devices- which boils down to mostly FPDs and BGAs ? Traditionally, FPD packs were opene
Electronics Forum | Wed Mar 27 21:20:30 EST 2002 | davef
There is two major BGA coating camps. * Camp #1: "We require the coating to be under low stand-off devices but with no filleting. So we apply a thinned dip coat first, and then top-off with a proper spray coat" * Camp #2: "We want no coating under th
Electronics Forum | Thu Dec 22 21:29:05 EST 2005 | davef
Josh: Room Temperature Vulcanizing (RTV) is Dow Corning's trade name for it's family of silicone cure sealants. RTV is about the worst kind of coating there is. Its chemistry is highly ionic and it requires atmospheric humidity absorbed to "complete
Electronics Forum | Fri May 21 14:22:56 EDT 1999 | Dave F
| Dave, | i tried reflowing bare boards with only solder printed on em and no component placed. we still got voids as same as when components were placed. so atleast one of that theories(voids due to component/component placement)could be considered
