Ball Shear

The ball shear test is another test to measure the wire bond strength at the first bond through the horizontal shear force. A bond shear tester is required in performing the test which consists of:

1) A shearing arm with a chisel-shaped tool at the end
2) An instrument for measuring the shear strength of the bond

The procedure consists of positioning the shearing tool just beside the ball bond to be tested and slightly above the surface of the first bond pad, then move the tool horizontally against the ball, in effect pushing the ball off its bond pad. The bond shear force is then measured by the ball shear tester in gram-force. The failure modes for ball shear test are as shown below:

1) Ball lifting
2) Ball shear
3) Pad lifting

Figures below show the illustration for ball shear testing and the result of ball shear.

the shear tool's position

the first bond pad showing normal ball shear

the second bond pad showing ball lift