THERMOMECHANICAL FATIGUE OF SOLDER JOINT AND INTERCONNECT RIBBON: A COMPARISON BETWEEN GLASS-GLASS AND GLASS-FOIL MODULES

摘要

The purpose of this study was to compare thermomechanical fatigue of glass-glass modules to glass-foil modules, including effects both on the solder bond and the interconnect ribbon. A comparison between glass-glass modules based on POE and EVA as encapsulants were also conducted. A 3D FEM-based model was used to study the fatigue damage to photovoltaic modules exposed to thermal cycling according to the IEC 61215 standard. With respect to thermomechanical fatigue of the interconnect ribbons, model results show that a glass-glass module is more robust than a glass-foil assembly with the same front glass thickness. In the coming years the market share of POE is expected to increase at the cost of EVA, and computed results show that a glass-glass module with POE as encapsulant is more robust with respect to this type of fatigue than EVA. Similar considerations for the solder layer connecting the busbar to the ribbon conclude that there is larger plastic work and damage both for a glass-foil assembly (POE) and a glass-glass module (EVA) than a glass-glass assembly based on POE as encapsulant. We conclude that such studies must account for a full-size PV module including fixation and the initial lamination process.