Testing method for measuring impact strength of BGA solder joints on electronic package

A pendulum-impact testing machine was developed to measure the impact strength of ball-grid-array (BGA) solder joints between an electronic package and a circuit board. Ball solders were connected to daisy-chain between a dummy electronic package and a circuit board. The upper side of the package was directly bonded to a load cell. The rear side of the circuit board was also bonded to an aluminum alloy block fixed on a base. A pendulum made of aluminum alloy was collided into the load cell to apply tensile impact to the solder joints through the load cell. The history of the impact load could be controlled by raising the angle of the pendulum. The fracture of a BGA solder joint was detected by measuring the resistance of the daisy-chain circuit on the board. Therefore, the impact strengths of the solder joints at electrical disconnection and mechanical breaking of all joints could be determined. The experimental results showed that this method is useful for measuring the impact strength of BGA solder joints.