Current Photovoltaic Research ISSN:2288-3274(Print) 2508-125X(Online)

Output power of photovoltaic (PV) modules installed outdoors decreases every year due to environmental conditions such as temperature, humidity, and ultraviolet irradiations. In order to promote the installation of PV modules, the reliability must be guaranteed. One of the important factors affecting reliability is intermetallic compounds (IMC) layer formed in ribbon solder joint. For this reason, various studies on soldering properties between the ribbon and cell have been performed to solve the reliability deterioration caused by excessive growth of the IMC layer. However, the IMC layer of the PV module interconnected by multi-wires has been studied less than using the ribbon. It is necessary to study soldering characteristics of the multi-wire module for improvement of its reliability. In this study, we analyzed the growth of IMC layer of the PV module with multi-wire and the degradation of output power through damp-heat test. The fabricated modules were exposed to damp-heat conditions (85 ºC and 85 % relative humidity) for 1000 hours and the output powers of the modules before and after the damp-heat test were measured. Then, the process of dissolving ethylene vinyl acetate (EVA) as an encapsulant of the modules was performed to observe the IMC layer. The growth of IMC layer was evaluated using OM and FE-SEM for cross-sectional analysis and EDS for elemental mapping. Based on these results, we investigated the correlation between the IMC layer and output power of modules.