Reliability Research on the Quality of No‐Gap Module Product

ABSTRACT In the photovoltaic industry, high module efficiency products are preferred in the residential market because these products can be used on the rooftop of houses or buildings with limited surface areas. There are two ways to increase the module efficiency: boosting module output for the same input energy or by reducing inactive area in the modules. When reducing the module size, the space between cells in a string can be eliminated by overlapping them. However, this overlapping areas can cause critical reliability issues such as cell crack, which can lead to decreasing module power during its lamination process. We demonstrate that this type of cell crack on the overlapping area can be resolved by applying wire flattening technology and developing encapsulation materials with the dynamic sheer viscosity data at different temperatures. The combination of the flattening technology and precured high melting index of ethylene vinyl acetate (EVA) are the key technologies, which result in less stress on the overlapped area, eliminate the cell cracks, and finally prevent the future potential reliability issue in the field. The cell overlapping technology presented in this article can be implemented to increase the module efficiency by +0.4%. Additionally, this study can contribute to the development of the high module efficiency module products for larger solar cells, such as M10 and M12 size.