A review of glass thermal reflow: method, device, and applications

Glass thermal reflow has emerged as a versatile technique for fabricating high-aspect-ratio and defect-controlled glass microstructures, offering a compelling alternative to conventional etching or laser-based approaches in MEMS and microsystem technologies. This review systematically summarizes the development of glass thermal reflow, including theoretical formula, simulation model, and key processing parameters that govern flow depth, morphology, and defect evolution. Recent advances in extended methods like double-sided reflow and glass-powder sintering are discussed, along with applications in unconventional microstructures, thermal and electrical insulation, and optical modulation devices. Future research is expected to couple advanced modeling and in situ characterization with material innovations to expand the scope of glass thermal reflow in next-generation MEMS, optical, and bioelectronic devices.