I am not sure if this helps.
We had complaints that a compliant assembly was having pads lift off at
the customers when their production soldered to the pads.
We did a series of experiments changing the soldering technique and
measuring the peel strength of the pads. Changing the hand soldering
technique, the alloy and the laminate material had very significant
affects upon the peel strength. I would therefore think it difficult to
relate bare material peel strength to the peel strength you would obtain
after your process. Our experience showed that different processes
caused the largest variation in peel strength.
We also sent someone to help the customer improve their soldering
process.
Regards
Rex

-----Original Message-----
From: Leadfree [mailto:[log in to unmask]] On Behalf Of Kane, Amol (349)
Sent: 25 August 2006 12:30
To: [log in to unmask]
Subject: [LF] Copper Pad Peel Strength

Dear Technetters,
We are having instances where copper pads (Under BGAs) are being lifted
off ENIG Boards almost too easily during rework. We use the same thermal
profile on each board (for the same component removal) and only some
show this phenomenon. Is there a test or standard to test the copper
adhesion @ incoming to see whether it's the fab (i.e. are the boards
coming to us with poor copper adhesion strength to being with) or the
process that's doing this. The board is heated upto 120 C when the
component is reflowed for removal. Also, is there data to show the
decrease in Cu adhesion strength with temp?

Thanks,

Amol Kane
M.S (Industrial Eng.)
Process Engineer
Harvard Custom Manufacturing, Inc. 
941 Route 38  Owego, NY 13827
Phone: (607) 687-7669 x349
[log in to unmask]
www.harvardgrp.com




CONFIDENTIALITY NOTICE: 
This e-mail, and any attachments, is for the sole use of the intended
recipient(s) and may contain information that is confidential and
protected from disclosure under the law. Any unauthorized review, use,
disclosure, or distribution is prohibited. If you are not the intended
recipient, please contact the sender by reply e-mail, and delete/destroy
all copies of the original message and attachments. 
Thank you.

------------------------------------------------------------------------
-------Leadfee Mail List provided as a 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 Leadfree To
temporarily stop/(start) delivery of Leadree for vacation breaks send:
SET Leadfree NOMAIL/(MAIL) Search previous postings 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 847-615-7100
ext.2815
------------------------------------------------------------------------
-------



This communication is confidential and its contents may contain opinions that are not representative of Hansatech. 
http://www.hansatech.co.uk/emaildisclaimer.php

-------------------------------------------------------------------------------Leadfee Mail List provided as a 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 Leadfree
To temporarily stop/(start) delivery of Leadree for vacation breaks send: SET Leadfree NOMAIL/(MAIL)
Search previous postings 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 847-615-7100 ext.2815
-------------------------------------------------------------------------------