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Date: | Wed, 28 May 2014 10:12:11 +0300 |
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Let me add a couple of eurocents worth.
1. Ion chromatography is useless for incoming board testing. Far too
long and far too expensive. By the time you have the results from a
valid sample of a batch (say 1-5%), your board will be obsolete.
2. SIR or ECM testing is useless for incoming board testing. Far too
long and far too expensive. By the time you have the results from a
valid sample of a batch (say 1-5%), your board will be obsolete.
3. IC, SIR and ECM are qualification tests, unsuitable for incoming
goods testing. Because of the chemical nature of the surface finishes,
it is impossible to extrapolate the results obtained during
qualification to production conditions, because there may be slight
differences in the stoichiometry of the resins and their various
treatments in board manufacture (or even changes of laminate
manufacturer) etc.
4. In my considered opinion, the *ONLY* practical test for incoming
boards in a production environment is ICT (Ionic Contamination Testing),
sometimes incorrectly called the "ROSE" test for historical reasons. It
is fast, if rough and ready, and will detect the presence of most (but
not all) of the harmful contaminants and bad stoichiometry of resins,
without necessarily identifying them (some testers will give indications
of the causes of problems by software analysis). Don't underestimate
this valuable tool.
Brian
On 23.05.2014 16:27, Richard Kraszewski 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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