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Reply To: | TechNet E-Mail Forum. |
Date: | Tue, 25 Jun 2002 16:03:08 -0700 |
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hi,
assuming that your base material was not cte matched to the ceramic j-leaded device, it's got to be that ole delta cte killer.
did you qualify this assembly by exposing it to a (at least what you thought to be) meaningful temperature cycling and vibration (since this assembly was mounted on springs) environmental life test environment?
phil
-----Original Message-----
From: Patricia Volkman [mailto:[log in to unmask]]
Sent: Tuesday, June 25, 2002 2:18 PM
To: [log in to unmask]
Subject: [TN] fractured solder joints
Fractured Solder Joints
My company has been doing hand assembly/soldering on a driver IC board for a
display that is used on a military airplane. The board uses 8 Holt ICs -
HI-8010SM-32 - http://www.holtic.com/ProPDFs/8010.C.pdf
The boards we provide have been in use for between 1 year and 8 years, the
actual time is unknown, but it is likely that they have been in place for a
long period of time.
The IC is a 44 pin QFP J-lead with 0.050 center spacing on the leads.
Our customer has recently found fractured solder joints associated with
these ICs (identical to those in photo - IPC-A-610C page 12-85 )
It is assumed that the fractured solder joints occured after leaving our
facilities, caused by airplace stress cycles or ???
I am looking for any information on why these fractures would occur, the
boards are spring mounted on the plane, the boards measure about 1.5" x 5".
Most importantly, I am looking for a solution to this problem, I am
currently looking for a more ductile solder...the solder used in the past
was Kester SN60PB40. I can also change the assembly process if that is
determined to be the root cause (all hand soldered)
thanks for any information you can provide.
Patti Volkman
(1-800-823-5588)
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