Pad cratering is an important failure mode besides crack of solder joint as it'll pass the regular test but have impact on the longterm reliability of the product. A new pin pull test method with solder ball attached and positioning the test board at an angle of30º is employed to study the strength of pad cratering. This new method clearly reveals the failure mechanism. And a proper wayto interpret the finite element analysis (FEA) result is discussed. Impact of pad dimension, width and angle of copper trace on thestrength is included. Some findings not included in previous research could help to guide the design for better performance [1,2].
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