Hi Phil

Whilst this is a later posting, can I just ask you: You measured 3.36 on your control sample - 3.36 what?

Dewey, I hope I am not spot-on with any big bang theory….or it'll be more than the corn rustling or popping! 

Graham 

On 9 Oct 2012, at 23:35, Phil Bavaro wrote:

> Bev,
> 
> Yes, ROSE tester calibration is current.
> 
> Test samples 1, 2, and 3 were "identical", but obviously not.
> 
> ROSE testing was performed one sample at a time but all within the span
> of an hour.
> 
> They were packaged individually and shipped to the lab inside the same
> container.
> 
> The manufacturing facility is in California and the lab is in Tennessee.
> 
> The blanks are the control sample which measured 3.36.
> 
> I think I can see where you might be heading so this next test run, I
> will try to be present for all phases of the packaging.  The devil often
> hides in the details and what seems obvious isn't always so.  Thanks!
> 
> Phil
> 
> -----Original Message-----
> From: Bev Christian [mailto:[log in to unmask]] 
> Sent: Monday, October 08, 2012 5:09 PM
> To: 'TechNet E-Mail Forum'; Bavaro, Phillip @ MWG - TW
> Subject: RE: [TN] ION CHROMATOGRAPHY - EXCESS CHLORIDE CONTENT
> 
> 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.
> 
> 
> 
> 
> 
> 
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