CURTAILING VOIDS IN FINE PITCH BALL GRID ARRAY SOLDER JOINTS
Author: Gary Morrison Company: Texas Instruments Date Published: 9/12/1999
Abstract: Minor voiding in Ball Grid Array (B GA) solder joints is a common phenomenon, so these voids are not often considered to pose a vital threat to solder joint reliability. It has been found, however, that incorrect handling conditions can create open solder joints during reflow. This paper investigates some causes of voiding and open solder joints, and recommends ways to avoid them. Various design and assembly parameters have been studied to understand the phenomena. Several factors that affect the formation of voids are reported. The investigation reveals that the cause of void-induced open solder joints is primarily outgassing of moisture from components where proper handling precautions have not been observed. If proper handling precautions are followed, these components are shown to have none of the excessive voiding described.