Research on femtosecond laser micro-hole machining technology of quartz glass

The advent of three-dimensional integration technology has heightened the demand for high-performance integrated circuits, with Through Glass Via (TGV) emerging as a critical component. This study investigates using femtosecond laser technology to micro-machine transparent and brittle materials, specifically focusing on producing high-quality TGV in JGS1 quartz glass. The research compares various scanning methods and identifies the "Top-down" transmission method as particularly effective for creating TGV with high aspect ratios and minimal thermal effects. The experiment evaluates the impact of laser power, spot overlap rate, and scan count per layer on TGV morphology, optimizing these parameters to develop a processing method suitable for JGS1 quartz and other transparent brittle materials. Results indicate that laser power significantly influences micro-hole diameter, with a power level of around 80mW maintaining a low taper, meeting the requirements for advanced packaging applications. The study also demonstrates the importance of scan count in enhancing TGV roundness and controlling surface defects. By optimizing laser parameters, this research provides an efficient and precise process for quartz glass machining, offering valuable insights for fabricating TGV in three-dimensional integration technology. The findings contribute to developing electronic devices with higher integration and performance. Future research directions include the integration of chemical wet etching, light field modulation, and multi-beam parallel processing to further improve the efficiency and quality of TGV fabrication.