Study On Vacuum Clamping System For Silicon Wafer

With fast developing of IC manufacturing technology, the size of silicon wafer is becoming larger and lager to increase yield of chips, while the thickness of the wafer is required to be thin as possible before packaging to meet the demand of IC packaging. The processing of lager and thinner silicon wafers, which are very fragile and easily deformed, brings many problems to traditional processing technologies. Therefore, it is necessary to develop new equipment and key technologies in processing large size silicon wafers. Positioning and clamping technology of silicon wafers is one of these key technologies, which has serious effects on the accuracy, surface quality and throughput of wafers. So study and design of positioning and clamping system have theory meaning and practical value for development of the ultra-precision grinding machine of silicon wafer.Vacuum clamp technologies are studied thoughtfully on a grinding machine which is based on wafer rotating grinding methods. According to schemes analysis, vacuum chuck with porous ceramic is selected for the vacuum clamping system. Considering of performance of porous ceramic and clamping effect, porous ceramic is adopted for clamping manufacturing. The vacuum chuck is designed as detachable structure, with characters of simple structure, easy manufacturing, low cost and reusable, etc. The vacuum clamping system satisfies the requirement of the wafer grinding processing. Two relays are locked each other to insure the security of vacuum clamping system. According to measurement result, which has been measured on the testing system, the clamping force formula is elicited.The vacuum clamping system works well and can meet the requirement of the wafer grinding processing, and will take pace of foreign products in the near future.