Bob,

Sorry that I made you look for that info on your own.  Yes, these devices
are lead-free.  We have asked twice now for specifics on the solder used and
on the profile but have yet to receive the requested information.  We have
only been told that the profile has been adjusted accordingly for lead-free.
The assembly house say that approx 80% of their work is Pb-free.

John Parsons
-----Original Message-----
From: Bob Landman [mailto:[log in to unmask]] 
Sent: Friday, November 19, 2010 12:38 PM
To: [log in to unmask]; [log in to unmask]
Subject: RE: [TN] BGA Falling off PCA

These are lead-free BGAs.  Was lead-free solder used and if so, what type?

Bob Landman
H&L Instruments, LLC
www.hlinstruments.com
LDF Coatings, LLC
www.ldfcoatings.com

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of John Parsons
Sent: Friday, November 19, 2010 3:32 PM
To: [log in to unmask]
Subject: [TN] BGA Falling off PCA

I am not seeing a lot of the usual Friday quiz traffic so I know you
guys-n-gals are just itching for some real work :o).

We are a PCB fabricator and one of our customers has returned some
assemblies to us for feedback.  What they noticed when someone accidentally
dropped an assembly is that the BGA (352 pin Cirrus Logic EP9312-CBZ) popped
off the board.  They then proceeded to drop a few more from a height of
about a foot with the same results.  All the other components on this
Pb-free assembly stay fast.  

We have received three PCA's and 5 BGA's.  On one of the BGA's a single ball
has remained on the PCB.  The rest of them all the balls have broken cleanly
from the PCB leaving a very flat (under x10 magnification) dull gray
surface.  I sure wish that I could take photo's but lighting is critical and
I don't think that I have the resources to get photo's that would do justice
to what the naked eye is seeing.

Also of note is that the BGA lands are mask defined with a 31mil circuit pad
and 26mil solder mask relief.

Does anyone have any ideas as to how we can determine the root cause of this
failure.  This part has been built for some time but previously the surface
finish on the PCB was a solder finish.  This is the first run of the boards
that has an ENIG finish.  This doesn't look to me like a raw board issue but
that is where everyone looks first isn't it ;o).

Regards
John Parsons


______________________________________________________________________
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
-----------------------------------------------------