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Date: | Tue, 27 May 2014 17:11:48 +0100 |
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Hi Richard
I was going to respond sooner but, being equally interested in the response, thought I would wait to see what was said.
IMHO this is not a suitable test.
My reasoning being that the test is run by washing / “de-ionising” the eluent until it squeaks. Then heating it to 80DegC, and immersing the specimen / sample into the eluent for 1 hour.
Problem? The laminate closely resembles a sponge, it is hydrophilic and contains more ions than you could shake a stick at.
Result? False negatives?
Why? Br could well be leached out through the mask onto the surface….but Br is a requirement…
I have had several board fabricators asking for assistance on this matter as they are struggling to get anything to pass….. my answer has been: Use SIR sir.
It does not discriminate between ionic and non-ionic contamination, it simply examines changes to insulation resistance that might be pre-cursors of unwanted electro-chemical activity.
Use IC when you need to know what is present that is causing the problem….or use FTIR?
Use Process Ionic Contamination Testing (PICT) to control the process. Fast, simple, relatively inexpensive and effective.
Always at your service,
BR Graham Naisbitt
On 23 May 2014, at 14:27, Richard Kraszewski <[log in to unmask]> wrote:
> I actually sent this out on May 16th, but never got a single response. Hoping that was not due to lack of interest, but rather due to the TechNet being down. Hence, I think I'll try this one more time.
>
> I am hoping to run an informal " min straw poll " here.
>
> Questions stated are as follows:
>
>
> 1. "Is your organization testing incoming PCB cleanliness via ion- chromatography? Replies such as "YES" or "NO" will suffice, but more detailed explanations are also acceptable.
>
>
>
> 2. " If testing via IC, do you use IPC -5704 Table 4.1 limits or other? Replies such as " IPC" or "other" will suffice, but more detailed explanations are also acceptable.
>
> What's in it for you? I will summarize and post the results after a few days of replies.
>
> Rich Kraszewski
> Senior Process Engineer
> Plexus
>
>
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