Electronic assemblies intermetallic compounds

Many North American companies are concerned that lead-free components and assemblies will not meet the reliability or functionality requirements necessary for high-end equipment supplied to banks, air traffic control systems, web-based businesses, and other mission-critical applications. Accordingly, manufacturers of aerospace and military electronics have no plans to introduce lead-free solders. There are too many reliability concerns to utilize lead-free solder materials in high-reliability equipment related to the mechanical characteristics of the materials themselves and the effects of high temperatures to process them. The effect of new and modified intermetallic compound phases within solder joints and at the interfaces is yet an additional concern, and there are many more. 

UBM) or as conductors, respectively. In all cases, fast diffusers not only diffuse extremely fast compared to other elements, but also form intermetallic compounds (IMC) vrith solder constituents. The values for activation energy for diffusion and the effective change (Z ) for some common materials utilized in electronics assemblies are listed in Table 1. 

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