Guys,
I got a heat sink look like potato chips after reflow using conduction hot
plate (230-240 C).  The heat sink is 1 cm thick Cu with few position screw
holes on 2 sides.  The size is 13.0x10.0x1.0 cm with 0.45 mm diagonal height
variation at the moment (one corner point to the sky and one down to the
earth).  Any remedy for the "cure"at this stage? ?  (it is Au/Ni plated).
Anything I can do to prevent from happening besides specify the annealed Cu
must be used?  (can't reflow on the other side, it has to bond to fan by
thermal compound).  Never see anything like that.  The internal residual
stress must be extremely high!
Thanks in advance for all your help...;-(
                                                                       jk

---------------------------------------------------------------------------------
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 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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------