Ceramic filled thermoplastic encapsulation as a design feature for a BLDC motor in a disk drive

Thermoplastics have made steady gains in use in a wide variety of motor applications. One of the few areas in which thermoplastics have not been effectively utilized are spindle motors. Central to the development of these applications is an understanding of the heat transfer and harmonic damping requirements of the applications and the cost/benefit relationships that exist. A simple model will be presented in which the heat transfer requirements for thermally conductive plastics can be understood and their costs can be estimated. Various filler systems and their performance will be discussed highlighting motor designs where these materials offer a competitive alternative to traditional construction techniques.