Effect of shock wave on micromechanical properties of SAC 0307/ENiG Solder joint using nanoindentation approach

Abstract

Reliability and durability of electronic packaging for electronic equipment in military application is beyond commercial applicability. The reliability of a solder joint is a key point in assessing the performance of electronic packaging. Commercial or conventional reliability testing such as JEDEC (Solid State Technology Association) standard is unable to fulfill the electronic packaging requirement for military standards. This study reported the response of SAC 0307 solder joint on printed circuit board (PCB) with ENiG surface finish (electroless nickel immersion gold) towards shock waves resulting from an open-field blast test. Micromechanical properties changes were investigated using nanoindentation approach. The solder joints were exposed to shock wave test using different doses of Emulex, 700 g and 1500 g, respectively. The solder joint’s hardness has decreased 29% from 141 MPa to 100 MPa after subjected to shock wave using 1500 g Emulex. The shock wave has led to the changes in micromechanical properties of the solder joints in terms of softening behaviour i.e. the decreasing of hardness and reduced modulus values. However, no cracks were observed between solder-substrate indicate that the solder joint is not fail and remains strong after subjected to high shock wave, despite the significant reduction in micromechanical properties.