CC BY 4.0Kaiser, ElisaElisaKaiserWiesenfarth, MaikeMaikeWiesenfarthVareilles, VictorVictorVareillesSchneider-Ramelow, MartinMartinSchneider-RamelowGlunz, StefanStefanGlunzHelmers, HenningHenningHelmers2024-02-062024-03-112024-02-062024Note-ID: 00008AAAhttps://doi.org/10.24406/publica-2580https://publica.fraunhofer.de/handle/publica/45968610.1109/JPHOTOV.2024.335540310.24406/publica-2580In micro-concentrating photovoltaics (micro-CPV), the size of solar cells is reduced (<1x1 mm 2 ) compared to conventional CPV. However, the quantity and requirement for placement accuracy of solar cells is increased. To be economically competitive, a promising possibility for the die assembly is a high throughput and relatively unprecise pick and place process combined with surface tension-driven self-alignment of the liquid solder. In this article, this approach is experimentally investigated, with a focus on the influences of solder volume, receiving pad layouts, and initial displacements of the cells on the self-alignment accuracy. Here, we show that an induced motion due to the initial displacement of the cells or due to solder flow along tracks leads to a more robust and accurate process. We found that less solder and rather smaller pads than cells (here by 92 μm or 10.4% of the cell length) are beneficial for self-alignment accuracy. However, for micro-CPV, conductor tracks connected to the pad are required for electrical interconnection and heat dissipation. Here, all cells are self-aligned and reach an accuracy between -15 and +15 μm, which is mainly due to the cell-to-pad size difference. Optical simulations show that this displacement would lead to an optical loss of 0.1% abs instead of 12.1% abs when displacing the cell by 150 μm. Thus, the self-alignment using the surface tension of the liquid solder leads to sufficient accuracy.enIII-Vmicro-concentrating photovoltaic (micro-CPV)module manufacturingpad layoutself-alignmentsolar cell alignmentsolder volumesurface tensionjournal article