Electrically conductive adhesives as cell interconnection material in shingled module technology

Modules, in which pre-cut crystalline silicon solar cells – or shingles – are assembled into solar modules by placing the pre-cut cells in a shingle-like way on top of each other, have gained a lot of market attention in the last years. Such cell lay-up in the module has as main advantage an increased module output, due to more efficient packing without inactive space between cells. An additional benefit is that no important modifications to the cell production process are needed. The first commercial market-available modules use electrically conductive adhesives (ECAs) to connect the pre- cut cells into strings. This paper will demonstrate that using ECAs with optimized properties will result in reliable solar modules. Adhesive properties such as adhesion strength, Young’s modulus, volume resistivity and contact resistance are shown in combination with the thermocycle reliability data of ECA-assembled modules. Application techniques suitable for high-volume manufacturing are demonstrated.