The effects of cracks on the thermal stress induced by soldering in monocrystalline silicon cells

Abstract

Silicon-based solar applications have tended towards the use of large, thin cells. However, an increased loss of materials occurs due to a high rate of destruction during the soldering and packaging processes. In this study, the effects of the presence of cracks on the thermal stress and stress intensity factor of the cells were explored for different aspect ratios of the soldering rods using an established finite element method. It was found that the residual stress in the cell was concentrated near the ends of the soldering rods, which coincided with the typical positions where breakage tended to occur on the cell. The residual stress on the cell increased with an increasing aspect ratio of the soldering rod. Cell damage due to cracking can be avoided by controlling the magnitude of the soldering rod’s aspect ratio.