Thermal Modeling of Triple-Junction Solar Cells Fan Out Wafer Level Packaging for Concentrated Photovoltaic

We explore Fan-Out Wafer Level Packaging (FOWLP) as a novel packaging approach, for Concentrated Photovoltaic (CPV) modules. This approach involves using reconstituted wafers containing multijunction solar cells embedded in Epoxy Molding Compound (EMC), with the cells interconnected by heat dissipating, thick interconnexion metal layer. This study proposes a detailed Finite Element Modeling (FEM) analysis to assess the thermal performance of a macro-cell and a micro-cell CPV module configurations. The FEM results indicate maximum solar cell temperatures of 63°C for the macro-cells and 60°C for the micro-cells. Those numbers are comparable to cells packaged using flip-chip, 58°C, or wirebonding, 69°C [1], assembly methods (flip chip and wire bonding, respectively and), demonstrating the potential of FOWLP, and below the maximum temperature recommended for such devices (80oC). The FEM also reveals that the FOWLP module with micro-cells exhibits more efficient heat dissipation compared to the one using macro-cells. A parametric study of heat sink thicknesses shows the viability of this approach for heat sink with thicknesses equal to or greater than 35 μm maintain the maximum solar cell temperature below 80°C, meeting literature-recommended thermal performance criteria. These results highlight the potential of FOWLP for concentrated photovoltaic applications.