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