Ball Shear Test is a destructive mechanical test that evaluates the bond strength of a ball bond (first bond) — by applying a lateral force to the bonded ball with a chisel-shaped tool until the ball shears off the bond pad.

What Is the Ball Shear Test?

• Standard: JEDEC JESD22-B116.
• Procedure: A shear tool is positioned next to the ball bond at a height of ~25% of ball diameter. Lateral force is applied until failure.
• Failure Modes:
• Ball Lift: Ball separates cleanly from pad (intermetallic failure — bad).
• Ball Shear: Ball deforms and shears through (bulk material failure — good).
• Cratering: Pad/oxide/silicon fractures beneath the bond.

Why It Matters

• Intermetallic Growth: Au-Al or Cu-Al intermetallic quality directly affects shear strength.
• Process Optimization: Monitors bonding parameters (force, ultrasonic energy, temperature, time).
• Cu Wire Adoption: Critical test for validating copper wire bonding on aluminum pads.

Ball Shear Test is the quality check for the first bond — verifying the metallurgical integrity of the connection between wire and chip.