Direct preparation of diamond heat dissipation microchannel assemblies by picosecond laser

The trend toward integration and miniaturization in modern chips poses a significant challenge to the thermal management of devices. Traditional thermal interface materials can no longer meet the heat dissipation requirements of high-power devices. Utilizing high-thermal-conductivity diamond for microfluidic cooling appears to be a promising solution. In this study, polycrystalline diamond was processed using an infrared picosecond laser system. We investigated the influence of processing parameters on the degree of diamond graphitization, as well as on the dimensions and taper of the fabricated microchannels. By optimizing these parameters to minimize graphitization, low-sidewall-taper (0.9°) diamond microchannels with an aspect ratio of 4:1 and a depth of 800 μm were successfully fabricated. Furthermore, the effects of different scanning strategies on the bottom surface roughness of the gutter were examined. A gutter with a depth of 800 μm and a bottom surface roughness of Sa 1.13 μm was prepared using a cross-scan strategy, and a through-hole with an inlet diameter of 1.1 mm and an outlet diameter of 1 mm was fabricated using a circular-drilling strategy. Ultimately, this work demonstrates the direct fabrication of a complete diamond microchannel heat sink assembly.