Thermal resistance modeling of linear motor driven stages for chip mounter applications

Heat transfer in linear motor driven stages for surface mounting device applications was investigated. A simple one-dimensional thermal resistance model was introduced. In order to reduce three-dimensional nature to one-dimensional, a few assumptions and simplifications were employed suitably. A good agreement with a finite element heat transfer analysis in temperature profile was obtained. For validation, the analysis was compared with the measurement with respect to motor driving power. Overall discrepancy was less than 7degreesC. The influences of two high thermal resistance parts, insulation sheet and thermal contact between the coil assembly and the mounting plate, were examined through the analysis. Additionally, the thermal resistance analysis was applied to another stage including an internal cooling-air passage, and was found to be available for this system as well. After validation, cooling effect was surveyed in terms of motor power and cooling-air and -water flow rate.