Hi Technetters,
Could someone advise me the reasons to following issue.

1.      There are total 25 boards for the evaluation purpose.
2.      Round 1, we assemble d11 units SAC BGA onto board of ENIG. The result
was 10 passed functioonal, 1 piece was not working. There was no signal &
power to the BGA unit.

3.      Round 2,  4 boards were being assembled, 3 passed, 1 was not working

4.      Round 3, 10 boards were biring assembled, 1 was working, 9 not working.

The above-stated boards undergo the same temperature profile.

At the beginning, we were suspecting the board of ENIG. When 1 BGA was
being removed from the failed board, and intend to perform the reballing,
we realise the not all BGA substrate pads were able to solder. Certain pads
were very dull and when solder is applied on it, it seened there was
dewetting issue.

My question is, if the failure of the BGA that was due to BGA's substrate
or otherwise.

By the way, such kind of issue happened only to one customer...
Thanks

KH Poh

---------------------------------------------------
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
-----------------------------------------------------