Thin Concentrator Photovoltaic Module with Micro-Solar Cells which are Mounted by Self-Align Method Using Surface Tension of Melted Solder

We are developing a thin and lightweight CPV module using small size lens system made from poly methyl methacrylate (PMMA) with a short focal length and micro-solar cells to decrease the transporting and the installing costs of CPV systems. In order to achieve high conversion efficiency in CPV modules using micro-solar cells, the micro-solar cells need to be mounted accurately to the irradiated region of the concentrated sunlight. In this study, we have successfully developed self-align method thanks to the surface tension of the melted solder even utilizing commercially available surface-mounting technology (SMT). Solar cells were self-aligned to the specified positions of the circuit board by this self-align method with accuracy within +/- 10 mu m. We actually fabricated CPV modules using this self-align method and demonstrated high conversion efficiency of our CPV module.