Electronics Forum: chromatography (Page 3 of 8)

Board change and solder not adhereing completely

Electronics Forum | Fri Apr 06 08:28:34 EDT 2001 | CAL

From what you are saying................If I hear ya correctly - There is no "Protective" on the Pads (OSP, HASL....) You will be hard pressed soldering to bare copper. This can not be right. My suggestion- go polyamide with electroptical connectio

Why is NC the prefer process for BGA mounting? why not WS?

Electronics Forum | Tue Aug 21 08:44:48 EDT 2001 | caldon

A) The standoff height of some uBGA components does not allow water to penatrate under the component. B)Water soluable may dilute the flux and not remove it all together. This can be tested with Ion Chromatography. C) Water soluable in some cases ne

Steaming boards

Electronics Forum | Thu Apr 24 09:34:37 EDT 2003 | caldon

We autoclave our medical PC boards (Sorry Bad Joke). With the Steam process I am concerned that the water (Solution) is not Clean. So I am curious to the process of steam cleaning: Is It Presure Steam? is the Water DI, ION free, street water...? you

PCB wash chlorine

Electronics Forum | Sat Oct 04 00:21:00 EDT 2003 | Dean

It would help to run a carbon, anion, cation, mixed-bed configuration with pure DI as the final rinse. IF your incomming water is really bad you can run a RO unit to "prepare" the water for ion exchange. Do you run omega meter or ionograph testing

PCB post reflow cleaning

Electronics Forum | Fri Mar 26 10:23:55 EST 2004 | Mike Konrad

Patrick, When you say "no-residue" what exactly do you mean? Is there truely "no-residue" or is it "no visible residue"? What type of ionic contamination results have you experienced? If you take a bare board that measures 0.0 NaCl and reflow it

ionic residues on the surface of printed circuit assemblies

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

Ion Chromatography (IC) qualification

Electronics Forum | Thu Apr 14 09:39:41 EDT 2011 | blnorman

ROSE has the advantage in that it does have a specific acceptance criteria (J-STD-001), whereas the IC does not. ROSE allows the test to be run at ambient or at an elevated temp, IC requires the component/board/assembly to be "cooked" for 1 hour @ 8

Conformal Coating Issues

Electronics Forum | Fri May 18 13:08:19 EDT 2012 | blnorman

I'll chime in here as well. If you have adhesion problems, 90% of the time it's contamination on the substrate (soldermask, flux residues, cleaner residues, etc.). Like Dave said, omega meter is a test for gross cleanliness, and it's OK for process

Acceptance Criteria Ion Chromatography testing?

Electronics Forum | Wed May 23 10:11:43 EDT 2012 | blnorman

Simple answer is no, there is no universally acknowledged acceptance criteria. Some time ago, I started a spreadsheet with the acceptance levels suggested by various labs on the individual ionic species. All are relatively close in their individual

Re: Ionic chromotography test on PCBA

Electronics Forum | Mon Jun 08 20:03:07 EDT 1998 | Dave F

Chiakl Ion Chromatography has been perfectly described by Dave, but here are a couple of extra considerations: Ion Chromatography will tell you precisely what is present on the surface of your board/assembly but it will not tell you whether it


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