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Reply To: | TechNet E-Mail Forum. |
Date: | Wed, 19 Dec 2001 07:57:26 -0600 |
Content-Type: | text/plain |
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Hi All
Here is another residue issue
We have an assembly which has a white residue remaining after wash.
The board is completely SMT (WS609) using a DI-Wash process, the board is
spotless except for one location. The location is a QFP (from CRONTEL),
the white powder is on the leads of the IC only. There is not a spot on
the PCB.
The Powder dry brushes extremly easily. On a few of the leads ( usually
about half way up the lead, nver near the joint)after brushing there is
evidence of flux residue( yellow sort of like Crystal Flux residue) in
spots.
We have put a few boards through the Omega with readings lower then
2.3microgram/sq.inch.
Could this be something the part manufacture has left/put on the leads? I
have noticed that the plating is thin on the leads (exposed copper on the
faces) the leads also look like sheared stock ( exposed copper on the sides)
Thanks
Andre
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