Thermo-mechanical modelling of polymer encapsulated electronics

This paper reports on some initial results from a research project investigating a novel technology for the manufacture of recyclable polymeric modules with embedded electronic systems. The aim of this project is to develop a technology that fully encapsulates electronics for use in the demanding automotive environment. A two shot moulding technology protect delicate electronic circuitry mounted outside of the passenger compartment from extremes of temperature, vibration and humidity. The resultant components also be readily recyclable, making it possible to cost-effectively separate electronic components from the polymer at the end of vehicle life, allowing the recovery of high purity recyclate. The encapsulating polymers have low thermal conductivity, so the process of encapsulation introduce a thermally insulating barrier around the electronics, which impact on the dissipation of heat from the components. In addition, the thermal performance of the assembly is further affected by the high temperature environments within which some of these electronic modules have to operate, such as under the bonnet of a vehicle. This paper presents the results of preliminary models developed for investigating the thermal and mechanical issues arising during the operation of such encapsulated electronics. Analytical models and finite element techniques have been employed to simulate the thermo-mechanical behaviour of overmoulded printed circuit boards.