Bond Strength Test of Soldering Pads with Various Surface Finishes Performed under Different Thermal Conditions

The goal of this study is to evaluate the bond between the soldering pad and the substrate in dependence on the solder pad finish as well as on ambient temperature. Stated differently, measuring of pulling force necessary for detaching the pad from the substrate is a subject of submitted study. A conventional substrate (laminate) made of woven glass cloth and epoxy resin with glass transition temperature value of 135 °C was available. OSP and HASL were chosen as surface finishes for evaluating the impact on the studied concern. Bond strength test was performed in room temperature and at an elevated temperature around 60 °C. An influence of IMC layers on test performing and results is included. Achieved results suggest a difference in the rate of adhesion of soldering pad to the substrate considering surface finish. However, other testing variables don’t affect the pad adhesion significantly.