Eva Cross-linking And The Study Of Crystalline Silicon Solar Cell Module Encapsulation Issue

Peroxide crosslinking EVA is widely used in c-Si solar module lamination process. The peroxide undergoes homolytic cleavage to form alkoxy radicals in heating process, alkoxy radicals abstract hydrogen atom from EVA chains, two radicals on adjacent polymer chains couple to form carbon-carbon bond. The crosslinked EVA performs better UV and thermal stability and mechanical strength. As an encapsulant for solar module bonding and sealing, EVA need to have good adhesive to various materials such as c-Si cell, glass, backsheets, insulation sheets etc.Solar module’s encapsulation needs vacuum laminator to finished EVA melt and crosslink. But sometimes some defects were found in solar modules lamination process and in damping heat aging after lamination, such as wrinkle defact sometimes was found on the backsheet or insulation sheets in lamination process and bubbles on inside module after damping heat aging. The defects analysis and the influence of crosslink reation degree to solar module lamination and stability in aging test have been studied by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) etc.The lamination process parameters including laminate temperature, vacuum time and pressing time is much important for EVA crosslinking. The crosslinking time finding method is studied by differential scanning calorimetry (DSC).