Electronics Forum | Fri Jul 26 17:02:07 EDT 2002 | davef
Never heard of flux residues forming a lense. The first thing that comes mind when thinking about your 'fog test' is: Ionic Contamination While this seems pretty far afield from your interest in optical effects, I'll continue briefly. A reverse
Electronics Forum | Thu Dec 12 13:53:01 EST 2002 | gregoryyork
Considering only Ionic residues is very dangerous, most heat transfer fluids that are extremely hygroscopic are also non ionic especially those used in HASL / Roller Tinning fluids. Also consider if the resist is cured or in fact porous which absorbs
Electronics Forum | Thu Aug 19 15:39:47 EDT 2004 | davef
This may sound dopey, but it may be the answer to your question. ROSE testers from different suppliers produce different results. Look at MIL-STD 2000. Based on Table VII, you find the following upper control limits (micrograms NaCl / sq. in.): * M
Electronics Forum | Tue Aug 31 15:43:41 EDT 2004 | davef
You�re asking the wrong person to give remedial math lessons. Anyhow, here we go: * [1.56 microgram NaCl/cm^2]*[2.54 cm/in]*[2.54 cm/in] = 10.06 microgram NaCl/in^2 * [Omegameter] / [MIL-P-28809 Beckman / Markson] = [10.06 microgram NaCl/in^2] / [GS
Electronics Forum | Sat Sep 25 03:44:38 EDT 2004 | GS
Thanks Davef, unfotunately in order to keep TIC of PBA inside our customer TIC requirements, we have to pre-wash (DI water only)connectors before assembly. Too high level of Br- continuosly get released by connectors molding compound. Our assemb
Electronics Forum | Thu Jan 18 15:28:10 EST 2007 | CK the Flip
If you are, in fact, running a No-Clean solder paste: Different no-clean solder pastes will leave different types of (benign) residues. If your paste has been qualified from a Bellcore/SIR/Electromigration standpoint, any residues remaining will NO
Electronics Forum | Tue Feb 08 04:27:55 EST 2011 | thomas111
hi, I am a Hardware designer . One of my products is undergoing a Reliability test in which a resistor shows a high value on board from its specified value .However it retains the original value when its cooled under room temperature. The resistor
Electronics Forum | Fri Jun 07 11:19:14 EDT 2019 | gregoryyork
If you have soldered with HASL finish then the worrying chemistry will be more like NON IONIC. They sit there and attract moisture like mad and any chlorides they hold ionize in the moisture attracted and cause electromigration or SIR issues. They ca
Electronics Forum | Fri Aug 16 12:32:56 EDT 2019 | edhare
Steve, Yes, in my experience clients send in field failures (so latent failures) that exhibit internal shorts when a secondary fracture propagates from a knit line fracture. These eventually short due to electro-migration from plate-to-plate through
Electronics Forum | Mon Jun 28 10:03:22 EDT 2004 | davef
First, welcome to your new job. Second, IPC-TM-650 2.6.14 is only loosely an �Ionic Contamination (Electromigration) Test�. * Electromigration Test, IPC TM 650 2.6.14, 2.6.14.1 * Ion Chromatography for Ionic Cleanliness, IPC TM 650 2.3.28 Third, I
