Thanks Brad. After research, we found the design is unbalanced. This is a
special, OEM, BGA where DFM was not taken into consideration. TAKE NOTE
DESIGNERS.
Rick

-----Original Message-----
From: Brad Saunders [mailto:[log in to unmask]]
Sent: Wednesday, August 29, 2001 3:38 PM
To: [log in to unmask]
Subject: Re: [TN] BGA Bow


Rick,

In my opinion; no, there is no way to rid yourself -reliably- of bow and or
twist on an existing PBGA.  It would seem to me it is a standard warpage
issue that is probably rooted in an unbalanced design, not so much material.

A pretty broad statement but I think true.
If you are successful in straightening out the curve, I think it will come
back to haunt you.... more sooner than later.

Coretec Brad