Enhanced Thermal Management of a 1.2 kV SiC MOSFET Half-Bridgec Fan-Out Panel-Level Packaging with Nanocopper Sintering Die-Attachment

Abstract

Sintered nano-copper (Cu) improves the thermal performance of SiC MOSFET Fan-Out Panel-Level Packaging (FOPLP), a widely adopted method for miniaturizing electronic systems and modules. This study presented, for the first time, the prototyping and characterization of a 1.2 kV SiC MOSFET FOPLP half-bridge power module using sintered nano-Cu die attachment (FOPLPCu), and compared it with a reference module using conductive Ag adhesive interconnects (FOPLP_Ag). Thermal, mechanical, and electrical co-simulations proved that FOPLPCu exhibited superior performances with lower thermal resistance, power loop parasitic inductance, and thermal deformation, achieving values of 0.14 °C/W (with double-sided cooling), 3.15 nH (@100 kHz), and 9.05e-5 m, respectively. In contrast, FOPLP_Ag showed higher values of 0.24 °C/W, 3.27 nH, and 1.04e-4 m. It is worth noting that due to the higher elastic modulus of sintered nano Cu, FOPLPCu experienced increased thermal stress. The internal structure analysis of the packaged devices, conducted using CSAM, showed that both FOPLPCu and FOPLP_Ag had well-formed interconnections, with no signs of delamination in the EMC, RDL, or interconnect layers. Thermal testing showed that FOPLPCu achieved a single-side thermal resistance of 1.95 °C/W, representing a 22% improvement compared to FOPLP_Ag's 2.5 °C/W. Electrical testing further demonstrated that FOPLPCu had lower on-state resistance compared to FOPLP_Ag, while maintaining comparable breakdown voltage, threshold voltage, and body diode forward voltage drop.