Electrically Conductive Adhesives for Photovoltaic Modules

Electrically conductive adhesives (ECAs) are used for the interconnection of crystalline silicon solar cells during the photovoltaic module integration as an alternative to soldering. These materials are lead-free, are processed at a temperature below 200 °C and are particularly suited to intercon-nect sensitive solar cells due to their mechanical elasticity. In this work ECAs are characterized and assessed with regard to their appropriateness for PV module integration. Electrical characteristics such as volume and contact resistivity are analyzed as well as mechanical properties (e.g. Young's modulus) or thermal stability. Besides characterization of the materials the effect of their proper-ties is studied by simulation. The relation to characteristics of the PV module such as maximum power and fill factor is obtained. Significant results of this work are the definition of assessment criteria for ECAs, the demonstration of a 60-cell photovoltaic module based on a new solar cell metallization pattern and ECA interconnection technology.