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Reply To: | TechNet E-Mail Forum. |
Date: | Wed, 31 Jul 2002 13:27:15 -0700 |
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I have built boards with silkscreen between chip component pads and had
problems with glue adhesion. The smt adhesive would peel the silkscreen off
the soldermask. Now when I see this in design I ask to have it removed.
Brad Vanderhoof
-----Original Message-----
From: Steve Thomas [mailto:[log in to unmask]]
Sent: Wednesday, July 31, 2002 9:16 AM
To: [log in to unmask]
Subject: [TN] silkscreen as solder dam?
Greetings...
Our overseas assembler wants us to add a line of silkscreen between pads on
bottom-side 0603 R's and C's,
apparently as a solder dam to reduce bridging in wave solder. There already
is mask between pads, so this seems
a bit out of the ordinary (we do very little two-sided assembly here but I
have never seen bridging on chips).
Has anyone ever seen this done? Does this sound like a design band-aid to
fix a process problem (talk about the flip side of
a coin!)? How do you attribute a bridge underneath a glued-on part to wave
solder? I don't have the benefit of a thorough
knowledge of their process, but I'm speculating they may be printing their
glue with a squeegee contaminated with solder paste.
Your thoughts?
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