Reliable thermal management of high-power semiconductor lasers based on nano-silver sintering diamonds

Thermal management is a critical challenge in high-power semiconductor lasers. Efforts to improve heat dissipation have led to the exploration of advanced packaging materials with high thermal conductivity, particularly diamond. Despite its promising properties, the integration of diamond into laser systems and the characterization of interfacial thermal transport remain unexplored. In this study, we propose a nano-silver sintered packaging scheme that integrates laser diode chips with cost-effective polycrystalline diamond (PCD) substrates. Comparative analysis of bonding interfaces reveals that pressure-assisted nano-silver sintering demonstrates superior thermal performance, with a measured thermal boundary resistance of 4.5×10-7 m2·K/W and shear strength of 19.24 MPa, significantly surpassing the performance of conventional AuSn eutectic bonding techniques. Experimental validation using wavelength shift analysis and computational simulations confirmed that the cost-effective PCD substrate reduces junction temperatures by 19 °C compared to AlN, thereby highlighting the synergy between high thermal performance, mechanical reliability, and industrial scalability. These findings establish a reliable, cost-effective framework for next-generation high-power lasers, addressing both thermal degradation risks and long-term operational stability in harsh environments.