The i-module approach: Towards improved performance and reliability of photovoltaic modules

Imec is developing a new concept, referred to as i-module (for interconnect-module), to integrate and interconnect back-contact solar cells into modules, which is based on embedding cells in silicone on top of a glass superstrate. This technology aims at an improved optical performance and reliability (through the use of silicones and low-temperature metallization), offering a module-level interconnection scheme (which implies interconnection only after the cells have first been fixed to the carrying superstrate). First, the paper elaborates the process flow, comparing it with the current standard technology for manufacturing modules. Then, some first mini-modules are discussed, demonstrating proof-of-concept for this kind of packaging technology. Finally, the strategy for assessing the reliability of such modules is indicated and illustrated with first results. This reliability assessment will be key for the viability of the proposed technology, as PV modules typically need to survive over 20 years in harsh outdoor conditions, where it is subjected to a (cyclic) combination of moisture, temperature, mechanical loads, electrical stress and UV bombardment.