Hi Edwin
General assembly: FR-4 boards - we do not bake.
General assembly: Polyimide boards - we do bake before wave soldering,
so as to avoid delamination in wave soldering operation.

Before rework/repair - we bake very thick boards to pre-heat them if we
have to rework through-hole connections (very rare).

We also have to bake to remove moisture if the rework is to a moisture
sensitive IC (or a near neighbor), if the rework procedure will heat the
component body.  So bake the board if the IC is to be removed, but not
for a solder joint touch-up...



regards,

Graham Collins
Process Engineer,
Northrop Grumman Canada Corporation
Halifax
(902) 873-2000 ext 6215

>>> [log in to unmask] 10/16/03 09:50AM >>>
iT HAS BENN OUR PRACTICE IN THE PAST TO BAKE OUT PWAS BEFORE SOLDERING
AT
EITHER 185 DEGREES f 0R 185 DEGREES F DEPENDING
ON WHETHER THE ASSEMBLIES OR BOARDS HAD BEEN PREVIOUSLY BAKED OR NOT.
tODAY
WE ARE DOING SMT AND SELEWCTIVE SOLDERING.
MY QUESTION IS," WHAT DO OTHER PEOPLE DO ABOUT BAKING BARE BOARDS,
ASSEMBLIES ON INITIAL SOLDERING AND BEFORE REPAIR?
aLSO, WHY DO YOU BAKE OR NOT BAKE?

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
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 or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at:
http://listserv.ipc.org/archives
Please visit IPC web site
http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700
ext.5315
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------