Technetters,

We have identified electromigration as the root cause of some field failures we have been seeing. During the troubleshooting we came across the following NASA paper. All of the details of this paper fits our situation perfectly. We use the same package as described. 

http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/40854/1/08-23.pdf

The executive summary is that the silver in the epoxy used to attach as die attach migrated to create a short. The migration was triggered by humidity.

The paper suggests using underfill or conformal coating to remedy the problem. Currently we do not use either in our process. I have some questions regarding these:

- What are the pros and cons using either of these for this particular purpose? IMO underfill seems the best solution for us.
- Does anyone have any experience as to whether this is a good solution? I am not quite understanding the "chemistry" here. 
- Does anyone have a recommendation as to what type of underfill would work well for this application? 

Thank you for your input.



--
Leif Erik Laerum



CONFIDENTIALITY NOTICE: This email and any attachments are Texas Memory Systems' proprietary material for the exclusive and confidential use of the intended recipient.  If you are not the intended recipient, please do not read, distribute or take action in reliance upon this message. Any unauthorized disclosure is prohibited.  If you have received this in error, please notify us immediately by return email and promptly delete all copies of this message and its attachments from your computer system. 


______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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
-----------------------------------------------------