Through-silicon-via formation of 3D electronic modules by laser radiation

Abstract

Laser heating is a promising method for through-silicon-via (TSV) formation in assembling highdensity 3D electronic modules due to its high specific energy and local heating ability. Using laser radiation for the formation of TSV makes it possible to reduce its diameter, indirectly increases the density of elements in 3D electrical modules. Laser system selection depends on the physical and mechanical properties of the processed materials and on the technical requirements for laserprocessing. The reflectivity of most materials increases with the laser wavelength. It was found that with an increase in the initial temperature of the substrate, the TSV taper becomes larger. Simulation was performed in COMSOL Multiphysics 5.6 to conduct thermal distribution during TSV laser formation. By modeling thermal fields in the COMSOL Multiphysics 5.6 software for laser processing of silicon substrates and experimental studies, the parameters of laser radiation have been optimized to obtain a minimum hole taper coefficient in the substrates of 3D electronic modules. The optimal duration of exposure to laser radiation with a wavelength of 10.64 microns is less than 2 s with holes taper 0.1–0.2.

Keywords

• laser radiation
• silicon substrate
• hole taper coefficient
• thermal field simulation
• initial temperature