Study on Carbon Dioxide Laser Cutting Technology for Alumina Green Sheet

Owning to its high photoelectric conversion efficiency and cost-performance ratio, carbon dioxide laser shows great potential as a cutting technique in inorganic-organic composites processing. The cutting process used on alumina green sheet with tungsten steel blade has been reported and widely used in industrial production. But the debris and scraps produced during the cutting process are difficult to be removed, and may induce serious quality issues. These problems can be solved during laser cutting process. Besides, it also has advantages of both maintain high cutting efficiency and low cost. But the application of laser cutting process on alumina green sheet is still restricted, due to the rough edges and dust raised during the process. A new 55w carbon-dioxide laser cutting system with flying light path is reported to processing green sheets of High-Temperature Co-fired Ceramic (HTCC). A prototype based on carbon-dioxide laser is designed and manufactured. Specially designed is the adjustment range of process parameters in the mechanical structure, electric control system and interactive software. In the mechanical part, vacuum cavity structure is optimized, and customized electromagnetic valve for high power vacuum cleaner for alumina green sheet viscous dust is redesigned. The electric control system is realized with IPC-based Hi-precision movement control board and Advantech USB 4751 control card, in order to accurately control the laser parameters, such as laser switching frequency, average power density and laser cutting speed. As for the interactive software, user interface of the program is designed to cover more control parameters, including full manual function and safety control. The effect of laser switching frequency, average power density, laser cutting speed, degree of vacuum at the back of green sheets and coaxial compressed air pressure is analyzed on the surface cleanliness of green sheets, laser cutting efficiency and the cutting quality. The Taguchi method is studied to optimize the experimental design, improving the cutting edge quality and dust quantity on the green sheet cut section.