Lead frame bond connections are susceptible to bond shear and peeling stress failure due to high thermomechanical loads resulting from the combined effects of thermal and vibration effects. Solder joint integrity has also been found to be highly dependent on the solder joint configuration, which, in turn, is determined by bond pad size, the alloy material, and the lead frame geometric details. This study considers the complete joint configuration in formulating the expression for bond stress. A new bond stress equation is proposed to predict the solder joint peeling stress at the interface between gullwing lead-frame and the solder layer. The proposed method considers the complete solder joint subjected to combined thermomechanical forces. Prior studies utilized symmetry conditions across the joint.

Issue Section:
Technical Papers
Keywords:
soldering, lead bonding, adhesion, thermomechanical treatment, stress analysis
Topics:
Solder joints, Stress, Thermomechanics, Solders, Shear (Mechanics)
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