Forum: SMT Production & Design
Thread: Lead-Free BGA Rework
Date: June 26, 2007 09:36 PM
Author: davef
Subject: Lead-Free BGA Rework
While your peak temperature measurement is probably correct, you probably ripped the pads from the board long before reaching that temperature. By using a steep temperature ramp, you are causing the corners of the BGA to curl away from the board and the center of the BGA. This curling movement of the corners of the BGA could be so strong that it is pulling the solder ball and the pad on the board with it before the solder of the ball becomes molten.
For more on this, search the fine SMTnet Archives on BGA warp*
(http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=50859)