(Received February 26, 2008; revised April 18, 2008; accepted April 27, 2008; published online August 8, 2008)
A method for estimating the impact strength of a solder ball junction in encapsulated semiconductor packages was developed. This method reveals the impact force in a solder ball unit and the time required for a solder ball to break. The bombardment absorbed energy required for the ball to break is evaluated as impact strength. This method can be used to quantitatively evaluate the impact strength of solder ball junctions, which is difficult to do using conventional shear and tensile strength estimation methods.
KEYWORDS:impact strength, quantitive estimation, drop test, shear test, solder ball