Ron,

Can you share what IWT you are using??  I would also be interested in the
results of your
analysis, if you care to share that data as well.

Tks....DT



At 04:13 PM 7/31/00 -0500, you wrote:
>Hello TechNet:
>We performed some experiments on Immersion White Tin boards and found the
>following . . . .  First, we had no problems with solder paste application.
>Second, no problems with vision systems, etc., and part placement.  Third,
>solder joints looked pretty good . . i.e. . no problems.  Here is the
>kicker.  The mounting holes on the top side were white tin.  The mounting
>holes need to be very flat for good contact so we do not apply solder paste
>to these holes.  The white tin, after exposure to humidity of the
>environmental chambers looked very oxidized and a flaky white powdery like
>substance was observed.  Also under some RF type connectors, the white
>powdery like substance was observed.  The powdery like flaky substance did
>not show up under any other components only the gold RF connectors.
>
>What experience have any of you had with the immersion white tin process?
>Any ideas, thoughts, etc., on the powdery white substance??? We are going to
>have our "product assurance forensic lab" analyze it and see what they come
>up with, but we also thought it a good idea to tap the intelligence of the
>TechNet World as well.
>
>Ron Hollandsworth
>ITT
>
>
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