Look for a website for sixsigmaservices.  Probably still around.  They made a small business out of this.  I believe they are a subsidiary of Winslow Automation, who sells re-balling kits as well.

Off the top of my head, reliability issues are mostly simple mechanical such as the mask holding up on the BGA, planarity of the new balls, etc.  It does add an extra two reflow cycles to the part, but since at least the second one is significantly below the standard ROHS limit of 260C, that it won't hurt the part.  If you insist on doing it yourself, be real careful of moisture sensistivity of the part.

Wayne Thayer

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of prashant chopra
Sent: Thursday, November 11, 2010 5:52 AM
To: [log in to unmask]
Subject: [TN] BGA reballing -- ROHS to Lead solder balls

Hi,

We are having a ROHS BGA which we want to use in the Non-ROHS (leaded) process. We are looking at option of having the BGA reballed. We would have the ROHS solder balls removed and replaced with the Non-ROHS solder balls.

I need help to know what can be the technical risks in using these BGA? Also, what can be the risk and issues associated with this reballing process?

Also, what are the critical precautions, checks and tests which should be done after the reballing of the BGA before we use them on the PWB?

Thanks to all for the support and advice.

Rgds
prashant


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

This e-mail and any files transmitted with it may be proprietary and are intended solely for the use of the individual or entity to whom they are addressed. If you have received this e-mail in error please notify the sender.
Please note that any views or opinions presented in this e-mail are solely those of the author and do not necessarily represent those of ITT Corporation. The recipient should check this e-mail and any attachments for the presence of viruses. ITT accepts no liability for any damage caused by any virus transmitted by this e-mail.

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