Optimization Design and Thermal Characteristics Study of Aerostatic Spindle Permanent Magnet Motor for Wafer Grinding

Wafer grinding is a key process for chip packaging, and the temperature distribution of the aerostatic spindle is an important factor affecting the grinding accuracy of grinding equipment. Traditional aerostatic spindles driven by induction motors will generate a lot of heat, which will seriously affect the wafer grinding accuracy. In this paper, based on the permanent magnet motor technology and heat transfer theory, and according to the working characteristics of the aerostatic spindle, an embedded permanent magnet motor for aerostatic spindle (ASEPM) is designed. The mathematical model of the electromagnetic field of the ASEPM is established, and the transient electromagnetic analysis is carried out using the finite element analysis software. In order to reduce the cogging torque and output torque fluctuation of the ASEPM, a new type of slanted pole segmented permanent magnet structure is designed. The influence of stator structure parameters, rotor segmented slanted pole mode and number of segments on cogging torque and output torque is analyzed, and the motor parameters are optimized. Taking the motor loss and the friction loss of the aerostatic bearing as the heat source, by establishing the thermal field model and structural field model of the aerostatic spindle, the thermal distribution and structural deformation of the aerostatic spindle are analyzed. This paper has a certain reference value for the design optimization of the aerostatic spindle motor and the temperature and structure analysis of the aerostatic spindle.