Growth of an Ag3Sn Intermetallic Compound Layer Within Photovoltaic Module Ribbon Solder Joints

Abstract

In this study, the characteristics of growing an intermetallic compound(IMC) layer at solder joint in photovoltaic (PV) ribbon solder joint were investigated through the thermal ageing test. Also, the growth rate of IMC in the ribbon solder joint, which depend on the temperature and time, was predicted through the ageing test. That the ageing test were performed under three different conditions: 90 °C, 120 °C and 150 °C. Also, we prepare the two type solder composition(60Sn40Pb, 62Sn2Ag36Pb) to analyze Ag addition effect in solder to forming IMC layer. Following testing, the IMC layer formed Ag3Sn in Ag sintered layer by Sn diffusion phenomena at high temperature. The thickness of Ag3Sn in solder joint was measured by cross-section images during the thermal ageing test. The Ag3Sn IMC layer was filled in sintered Ag layer in 70 h under the harshest conditions of 150 °C and 750 h at 120 °C. The Ag3Sn thicknesses were calculated to activation energies forming IMC layer in solder joints. The results, the Ag3Sn growth rates under the various temperatures were predicted for long-term reliability of PV modules. © 2019, The Author(s).