Electronics Forum | Wed Sep 02 02:45:01 EDT 2009 | rocko
Hi All, Let me summarize the key facts and findings: 1) This is not a permanent problem. Only one production batch was affected. The cleaning solution was exchanged and now the cleaning process runs normally. 2) Probably the residues are not ion
Electronics Forum | Tue Sep 01 11:25:19 EDT 2009 | rocko
Hi davef, Thanks for the suggestion. I have inspected the heaters but I think they are OK (no visible coating, deposits, etc.). Unfortunately, I'm not sure that the residues are ionic. It was just preliminary report of the person responsible for the
Electronics Forum | Sat Jan 27 08:45:43 EST 2007 | davef
[clipped] Chemistry of Hard and Soft Water From Anne Marie Helmenstine, Ph.D., Your Guide to Chemistry. Water Works I'm sure you've heard the terms 'hard water' and 'soft water', but do you know what they mean? Is one type of water somehow better th
Electronics Forum | Thu Sep 20 01:13:05 EDT 2001 | Michael Konrad
Hi Dave, It may be. DI water alone will not build up residue. It can attack the finish of electro-polished (mirrored) stainless steel though. I have seen a white / chalky buildup on poly inline cleaners, usually isolated in the wash section. The
Electronics Forum | Thu Dec 20 19:41:27 EST 2001 | ianchan
I called a cuppa of indutrial friends, and they concluded that the flex-PCB in question, was being subject too high a oven-baking temperature of 100deg-C...50~60deg-C oven-baking temperature would be more appropriate for flex-PCB, due to its very pad
Electronics Forum | Thu May 31 21:45:48 EDT 2012 | davef
rsthompson ... if you're talking about bare boards IPC-5701, Users Guide for Cleanliness of Unpopulated PBC, Table 8 ||Bare board final surface finish Ions||Hot air solder level||OSP over copper||Gold over nickel Chloride||0.75 ug/cm^2||0.75 ug/cm^2
Electronics Forum | Thu Sep 27 23:24:22 EDT 2007 | mika
Fe2+(aq) + 2e- "harply, but this is of no consequence since OH- ions are always present, even in pure water.) The cations then react with the OH- or even the H+ ions and dissolved oxygen to form a variety of compounds, which constitute rust: Fe2+(aq
Electronics Forum | Fri May 21 12:24:21 EDT 1999 | KA Stillings
I normally handle the soldering issues for this facility but a question was asked of me -- What the H@## is this stuff and what is causing it? Was wondering of I could get some input from any Guru on plating issues. Need info ASAP!!!!!!!!!!!!!!!!!!!
Electronics Forum | Tue Aug 03 18:11:21 EDT 2004 | davef
Improper washing of water soluable flux residues can be a major contributor to flux residues remaining on the board surface. ;-O That you appear to be only complaining about the pathetic state of the ability of your washer to clean under BGA, it may
Electronics Forum | Thu Feb 10 22:55:50 EST 2000 | Dave F
Fred: I'm tryin' my darndest to be good, because, for whatever stupid reason, I feel that you're making an honest inquiry and not just floating something to find the biggest sucker. If only Earl was still here, he'd always bite on stuff like this.
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