Voids and Bond Defects
Flip Chip Underfill Void and Solder Bump Defects - Application Note 1016
Sample & Method
Part of a Flip Chip development project, this package was imaged by C-SAM ® through the substrate side. Gating was on the interface between the cured underfill and the substrate, and includes the bonding of the solder balls to their pads.
Red areas are large voids in the underfill. In addition, the area of bond of the solder balls (white) is in many instances incomplete, indicating that these solder balls are only partially bonded.