Mr. Pauls was my dad. Here in Iowa, the Big Bang refers to days when the temperature is over 105 and the fields of popcorn start to go off. And I already commented Dewey. Get with the program. You can only blame the 2 hour time difference so many times. Doug Pauls From: "Whittaker, Dewey (EHCOE)" <[log in to unmask]> To: <[log in to unmask]> Date: 10/09/2012 09:26 AM Subject: Re: [TN] ION CHROMATOGRAPHY - EXCESS CHLORIDE CONTENT Sent by: TechNet <[log in to unmask]> Just when you think this is another one of his big bang theories; he's spot on. It's probably the printed boards, but I only do class acts so I'll let others do the corn. I hear the rustling of the stalks in Iowa, so you'll likely being hearing from Mr. Pauls soon. Dewey -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Graham Naisbitt Sent: Monday, October 08, 2012 9:54 PM To: [log in to unmask] Subject: Re: [TN] ION CHROMATOGRAPHY - EXCESS CHLORIDE CONTENT Phil and Bev Not necessarily strange. Phil, you say you passed ROSE test "of course". What is your pass/fail criteria <1.54microgrammes NaCl? If yes, then no wonder it fails IC. IC is intended to tell you EXACTLY what is on an assembly surface that might be causing an electro-chemical problem ...that should have been established as a problem from SIR tests. If it passed SIR tests, then is that "pesky result" really an issue? As I have maintained: Use your ROSE test to control your process - not based upon some spurious pass/fail limit. Then run SIR If there's a problem, run IC or FTIR or more to find out what the root cause is. As regards your control coupon failing - Might I presume that there is a solder resist / mask present on the bare board? In most of our test work it is the bare board that harbours the most problems - get that right, and...bazinga! Graham Naisbitt On 9 Oct 2012, at 08:09, Bev Christian wrote: > Phil, > Very strange. > > Has the ROSE tester been calibrated? > Physically what is different between one test sample and the other two? > Were all three test samples ROSE tested together or separately? > Were they shipped together or in separate bags or even in totally separate > packages? > How far away is your manufacturing facility from the lab? Next door? Next > city? Next state? > What are you getting for chloride readings for your blanks? > > Bev > > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]] On Behalf Of Phil Bavaro > Sent: Monday, October 08, 2012 7:30 PM > To: [log in to unmask] > Subject: [TN] ION CHROMATOGRAPHY - EXCESS CHLORIDE CONTENT > > We have some results that have left me puzzled. We are processing the > IPC B-52 test PWAs using water soluble paste/flux and we can pass the > ROSE test (of course) and the SIR test, but fail the IC test for > excessive choride anion content. > > Here is what baffles me.....our control sample is similar and worse than > the test samples. > > There seems to be some documentation that the chloride ion might be > related to mishandling and/or soldermask not being properly cured but I > don't have any experience with this test result so I am not sure how to > respond to that (hopefully Terry will chime in on this). We processed > all the samples using the proper gloves and bags and doubt that we > contaminated them. > > We are trying to meet the requirement of 0.9 micro-gm/cm-cm maximum and > our failing control sample is 3.36, one test sample is 4.67, and the > other two samples are running at .91 and .90. What value for chloride > anion content does a normal WS process yield? Are these numbers way out > of range for normal test results or is chloride always a pesky result? > > I am looking for the answer to the question "is this really a problem?" > > The control sample was washed but did not have any paste applied to it > at all. The test samples were run through the full assembly reflow > process then cleaned and Rose tested before shipment to the lab. > > All the rest of the results for the IC test are passing so I don't know > quite how to proceed from here. > > My current plan is to run another set of tests with more than one > control sample, and then to simulate various phases of clean (IOW barely > cleaned, half cleaned, and then a couple of fully cleaned samples). As > I am not really familiar with IC test results, I want to see the what > the constituents of the "dirt" really look like from an IC test > perspective as well as repeat the previous test results. > > One item I have noted is that we did not have our chosen board supplier > build these boards but instead bought these off the shelf from one of > the dummy component suppliers. But the thought was that as long as they > were cleaned using our normal process, they should be acceptable. > These particular test samples use FR4 and not the high Tg polyimide that > most of our PWBs are built from. > > Any comments on this would be appreciated. > > ---------------------------------------------------------------------------- > -- > This message and any attachments are solely for the use of the addressee and > may contain L-3 proprietary information that may also be defined as USG > export controlled technical data. If you are not the intended recipient, any > disclosure, use or distribution of its content is prohibited. Please notify > the sender by reply e-mail and immediately delete this message and any > attachments. > > > > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ > > > ______________________________________________________________________ > This email has been scanned by the Symantec Email Security.cloud service. > For more information please contact helpdesk at x2960 or [log in to unmask] > ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. 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