Identification of Brittle Solder Joints using High Strain Rate Testing of BGA Solder Joints

With the proliferation of limited life portable electronics the focus of electronics reliability has shifted from long term to short term ruggedness. The probability of a solder joint failing due to mechanical shock is the critical issue. Traditional mechanical reliability testing methods such as three or four point bend tests do not truly recreate the high strain rates experienced in drop shock. New techniques such as high-speed ball pull and high-speed ball shear, impact shear and drop shock are being developed in the industry to test and identify the brittle nature of solder joints and estimate their probability of failure due to mechanical shock. Cookson Electronics has been aggressively developing materials and processes for improved drop shock reliability. In this article we present some of our recent research results on the development of high-speed ball pull testing and success with the technique in differentiating between ductile and brittle solder joints.