Thermal design for high power arrayed LED heat-dissipating system

摘要

In this paper, an improved heat dissipating system for high power arrayed light emitted display (LED) was designed and validated. Heat sink was embedded to reduce the hot spots and improve the reliability of LED lighting system. As the power of LED increases lots of heat will be generated and, in turn raises the temperature. This will greatly deteriorate light efficiency and shift the wavelength. Heat dissipation under different heat sink has been carefully designed by finite element analysis. Various kinds of heat sinks are designed for LED chips and an extensive numerical investigation of the heat sink design performance is conducted by commercial finite element package ANSYS. Concerning a single chip LED and arrayed chips LED, Heat sinks with more fins lead to lower junction temperature because of larger surface. The effects of heat sink structure and material, adhesive and environment temperature are investigated. It can be seen that the higher the thermal conductivity of the adhesive, the thinner the thickness of the adhesive, the higher the thermal conductivity of the heat sink materials, the lower the junction temperature and junction-ambient thermal resistance are. As the ambient temperature increases, the junction temperature increases linearly while the junction ambient thermal resistance changes little.