Abstract

Electrically conductive adhesive (ECA) interconnections between solar cells are gaining more and more relevance since they provide a solution to realize lead free, elastic bonds, which inflict low mechanical stress on the solar cells. Here we investigate the long term stability of such interconnection joints by accelerated degradation testing in a climate chamber. For that purpose, mini-modules with shingled cells using different ECA formulations and different module materials are assembled and their electrical properties are recorded via IV and EL measurements before and after climatic chamber tests. We found varying power losses for the different ECA´s after damp heat testing (DH2000) and thermal cycling (TC800) testing. Modules of one ECA are stable after both tests, one configuration shows average power degradations around 1.4 to 3 % after both tests and the third one tested revels an average power drop of 25 % after DH2000 testing while it is stable after TC800.