Hi Bev! To quote Sir Doug "Mt Dew" Pauls "it depends on the project"! As a
matter of routine we always report the details of wetting characteristics,
solder joint geometry, and any "unusual" microstructure. The "unusual"
microstructure details would include excessive voids, plating defects,
large dendrite structures, nontypical intermetallic phases/layers, and
solder joint cracks. We only measure and report on detailed microstructural
characteristics if the project could potentially cause changes in the
microstructure - such projects like oven profiles of unusual printed wiring
assemblies, the implementation of new solder alloys, the use of new surface
finishes (either on the component or boards), or multiple/excessive reflow
excursions. Good Luck.
Dave Hillman
Rockwell Collins
[log in to unmask]
Bev Christian <[log in to unmask]>@ipc.org> on 03/19/2002 02:04:41 PM
Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond
to Bev Christian <[log in to unmask]>
Sent by: TechNet <[log in to unmask]>
To: [log in to unmask]
cc:
Subject: [TN] Cross-sectioning question
TechNetters,
I have a two fine fellows who work for me who come from different
backgrounds. With regards to cross-sectioning solder joints, one is used
to
providing his customers with a metallurgical description of the metal in
the
joint. He says it is important to describe the number and size of tin and
lead dendrites, grain size, lamellar or otherwise general structure, etc.
The other says this is not necessary. Both of course agree on fillet size,
shape, cracks, voids, presence/absence/thickness of intermetallic.
Now I agree that grain size is not going to give you much, since solid room
temperature solder is close enough to its melting point that the grain size
will change within a few months anyways. But what about the rest?
regards,
Bev Christian
Research in Motion
---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send e-mail to [log in to unmask]:
SET Technet NOMAIL
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search previous postings at: www.ipc.org > On-Line Resources & Databases >
E-mail Archives
Please visit IPC web site http://www.ipc.org/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
---------------------------------------------------------------------------------
---------------------------------------------------------------------------------
Technet Mail List provided as a free service by IPC using LISTSERV 1.8d
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives
Please visit IPC web site http://www.ipc.org/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------
|
