Research Of Grinding Dynamometer For Φ300mm Silicon Wafer

Grinding force is an important parameter to reflect grinding process, which has a direct influence on machining precision, machining quality and grinding wheel wear condition ect. The grinding state can be understood timely by monitoring variation of grinding force. Accurate and reliable measurement of grinding force can control grinding process timely, optimize grinding parameters, maintain optimum grinding process and improve grinding efficiency.Based on the structural characteristics of silicon ultra-precision grinder, the installation plans of grinding dynamometer are discussed. The grinding dynamometer is integrated in the wheel spindle with ring structure. Based on two different spatial arrangements of the sensors, lozenge and square, the mathematical model of dynamometer is built and the formula is derived from theoretical analysis. Furthermore, the stress state of sensors is simulated by finite element software. The analysis results show that four piezoelectric sensors with square arrangement is more suitable for the measurement of grinding force. According to the performance requirements of grinding dynamometer, the piezoelectric dynamometer integrated in wheel spindle with square arrangement is developed. In order to simulate the actual installation state of dynamometer and calibrate in laboratory, the calibration device of grinding dynamometer is developed. Afterwards, the static properties of dynamometer are experimentally tested in a special test rig. The experiment results show that the static performance indicators meet the requirements of grinding dynamometer.In combination with the practical working condition of grinding dynamometer, the static properties of the grinding region is measured and analyzed. Eventually, the on-line static calibration and the actual grinding experiment of dynamometer installed in the silicon wafer grinder are performed. The results indicate that the grinding dynamometer has good properties, which reach the design requirements of grinding force test system. And the dynamometer is very suitable for measurement and monitoring grinding force in silicon wafer grinding process.