The companies doing the assembly perform the mitigation processes since the
lead frames are processed unplated until the end of the assembly - packaging
flow.  The exception is NiPdAu plated leadframes.  These are plated by the
LF maker, before any assembly processes, but this lead finish is generally
accepted as presenting no whisker risk.  A purist may say that Au can grow
whiskers, but it is essentially a non-issue.  There is some evidence that
whiskering is affected by the type of copper leadframe used but this
material is generally specified by the assembler.


Best regards,
Leo

Leo M. Higgins III, Ph.D.
Vice President, Technical Support Operations
ASAT, Inc.
3755 Capital of Texas Highway, Suite 100
Austin, Texas     78704

office phone   512-383-4593
mobile           512-423-2002
[log in to unmask]
www.asat.com


The information contained in this electronic message is CUSTOMER/SUPPLIER
PRIVILEGED AND CONFIDENTIAL INFORMATION intended only for the use of the
individual or entity named above. If the reader of this message is not the
intended recipient, you are hereby notified that any dissemination,
distribution and copying of this communication is strictly prohibited. If
you have received this communication in error, please immediately notify the
sender by electronic mail. Thank you.



-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Dehoyos, Ramon
Sent: Friday, April 21, 2006 8:34 AM
To: [log in to unmask]
Subject: [TN] Lead Frame Suppliers




        Hi Technetters:
        Does anyone know names of companies that manufacture leads for
components. I am interested in knowing whether those companies are doing
something to mitigate whiskers such as annealed matte tin metal finish.
In a previous life (semiconductor manufacturing FAB), we used to get
sheets of lead frames for the chips (die) that we manufacture. I am sure
those leads were bought from another company.
        TIA
        Ramon

---------------------------------------------------
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
847-615-7100 ext.2815
-----------------------------------------------------

---------------------------------------------------
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 847-615-7100 ext.2815
-----------------------------------------------------