The reliability of OLB joints of gold-plated TAB leads

The reliability of outer lead bonding (OLB) joints of gold-plated tape automated bonding (TAB) leads after hot bar soldering is investigated. The consequences of thermal aging at elevated temperatures on the solid-state diffusion reactions are studied. The activation energy for the growth of the ternary CuAuSn intermetallic compound is determined to be 0.47 eV. Both aging and thermoshock treatment cause an embrittlement of the solder joint without substantially weakening the mechanical strength, even at severe test conditions.<
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