Quasi in-situ observation of Ni-plated solder from various fracture mechanism using EBSD

Abstract

In this study, Electron Backscattered Diffraction (EBSD) was used to investigate the blocking effect of novel electroplated Ni in order to inhibit the growth of IMC layers in high density packaging technology. The diffusion of interfacial elements was analyzed as the main cause for compound growth after high temperature storage. The grain orientation tends to be consistent and the grain size increased with increasing time. And the blocking effect of Ni was calculated from the atomic diffusion level. Moreover, the mechanical properties showed an increasing and then decreasing change with time. In nanopush ball experiments, we observed three fracture modes. The fracture type shifted from Type I to Type II to Type III due to the increase of IMC thickness and the generation of Cu6Sn5.

Keywords

• SnAg solder
• Shear strength
• EBSD
• IMC
• Thermal ageing
• Ni electroplating