Semiconductor Photo Gallery

 

 

Bond Pad Metal Lifting

      

Figure 1. Lifted ball bond due to bond pad metal delamination (left) and the bond pad metal delamination itself (right)

          

Figure 1 shows SEM photos of a lifted ball bond (left) and the bond pad from which it lifted off (right).  This ball bond lifting occurred because the bond pad metal delaminated from its underlying barrier metal layer. A portion of the delaminated bond pad metal was torn off but remained attached to the ball bond, as seen in the left photo.

      

Thus, in this case, the adhesion of the ball bond to the bond pad surface metal is good, which is why it was never detached from the bond pad metal even if it was subjected to a stress that's large enough to tear a portion of the bond pad away from the die.  The problem in this case is the poor adhesion of the bond pad metal to its underlying barrier metal.

   

See Also:  Wirebonding; Bonding Failures

      

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