hi,
did you remove the transceiver chip then resolder that chip to the pwb? if so, case closed; soldering would seem to be the problem. you should have your vendor solder them the way you do.
if you replaced the poorly performing transceiver with a 'new' one, did you compare the performance of the removed part with the one you are replacing it with?
sounds like a candidate for a designed experiment.
phil
-----Original Message-----
From: Marty Brooks [mailto:[log in to unmask]]
Sent: Wednesday, March 28, 2001 1:41 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
This email contains confidential information and is intended for the sole
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