Optimised Heat Sink

The Problem

Hand calculations suggested the likelihood of operating temperatures outside of the permitted range in parts of an Antenna Module. By performing a Thermal investigation into the local temperature characteristics within a simplified Antenna Module issues or problem areas in the design were highlighted. This allowed optimisation of the integrated heat sink design.

The Approach

Boundary conditions such as heat transfer coefficients and thermal loads were applied, in particular at the individual component locations. Material properties were obtained from component data sheets. Simulations were carried out for various models with the inclusion of an additional heatsink. Natural convection provided cooling to the exterior of the unit and air circulation within the sealed module.

The Result

The results indicate that the maximum temperatures greatly exceeded the comfortable working temperature. This was due to the fact that the components had undersized thermal paths to the heatsink and were therefore unable to transmit their dissipated power to the environment effectively. The enclosure temperature was also found to exceed the safe working temperature for short heatsinks. A redesign of the thermal paths and a larger heatsink area provided an acceptable solution to the problem.