System for reducing metallic whisker formation

Abstract

Disclosed is a whisker-formation resistant composition that is suitable for use as a lead-free soldering composition. The composition includes a fusible material and a matrix material that is aggregated with the fusible material. Typically the fusible material has a lower melting temperature than the melting temperature of the matrix material and has a coefficient of thermal expansion that is higher than the coefficient of thermal expansion of the matrix material. Also provided is a method of reducing the formation of whiskers adjacent solder that bridges a joint. The method includes the step of melting a fusible material adjacent the joint. A further step is solidifying the fusible material while establishing a static tensile stress tendency in the fusible material.

Dependencies are inferred from the claim text.