Most of the time, RF components need the body (under the component) soldered
to the PWB for proper grounding. I'm no RF engineer, (God forbid) but I
understand that this grounding can be critical for performance. Perhaps
this is a good place to start.
Jim Marsico
Senior Engineer
Production Engineering
AIL/Electronics Systems Group
An EDO Company
[log in to unmask] <mailto:[log in to unmask]>
-----Original Message-----
From: Marty Brooks [SMTP:[log in to unmask]]
Sent: Wednesday, March 28, 2001 4:41 PM
To: [log in to unmask]
Subject: [TN] RF Assembly Issues
We are experiencing a concerning variation from board to board in
the
performance of our RF product. We have investigated several causes
of the
problem and are currently of the opinion that soldering quality of
the
transceiver chip is the most significant contributing factor. As an
example, on the last run of prototypes that was manufactured, the
signal
frequency was at the upper limit of the allowable range. We removed
and
replaced the transceiver chip in-house and decreased the frequency
closer to
what we would expect.
I'm going to be making a visit to our contractor's facility next
week to
investigate this problem and would like some feedback on possible
causes or
process controls that I should look into.
The board is 4 layers, HASL finish, single side smt, solder paste
used is
Alpha's UP78 no-clean. The transceiver chip is a 20-pin device with
terminations flush along the bottom of the component.
Thanks for any advice.
Marty Brooks
Manufacturing Engineer
IDENTEC Solutions, Inc.
102, 1860 Dayton Street
Kelowna, B.C., Canada V1Y 7W6
Ph:(250)860-6567, Fax:(250)860-6541
www.identec.com
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