Reliable and Automatable Solution for Shingle Bussing

Shingle matrix technology is a way for creating efficient and visually appealing photovoltaic modules resistant to partial shading. The specific technical challenge addressed in this work is connecting metal bus connectors to shingle strings and shingle matrices, given the unequal coefficients of thermal expansion (CTE) between copper and silicon. To counter this, the proposed solution introduces the use of an electrically conductive tape (ECT). Applied post-cell interconnection, the ECT minimizes thermo-mechanical stress due to the absence of a curing step. Adhering the ECT to a large area of the rear sides of shingle cells ensures low ohmic contacts. This study presents experiments evaluating various ECT products and widths in relation to accelerated temperature cycling (aTC). Notably, there is a correlation between the ECT width and degradation during aTC, emphasizing the need to optimize this parameter. The derived module design, enabling an automated bussing, minimizes thermo-mechanical stress during production. Reliability testing of full-format matrix modules demonstrates durability in accordance with the industry standard IEC61215.