Thermal Resistance Calculation Method of High-power LEDs
Estimation method of thermal resistance of high-power LED to predict junction temperature in the early stage of design is important to make good thermal management. Methods based on infinite series techniques require the summation of a large number of terms with coefficients that depend on boundary conditions leading to lengthy expressions whose relationship with die geometry of system is difficult to establish. Numerical simulation methods based on FEM or FDM are often of little help in early stages of design, because they require a great effort to precisely define the problem. The method present in this paper is based on the constant angle heat spreading model, taking the border effect into account, yields the accurate results over the whole range of chip dimensions and substrate thickness conditions. In this paper we assume the sidewalls and the top of the LED package to be adiabatic with the bottom surface bonded to the heat sink. A special function is used to replace a segmented function to keep the model continuous. The final expression of thermal resistance calculation for circular chip is consistent for all the border parameters. After we derive the model of circular power dissipation element of radius r on a substrate of thickness h, with a heat-spreading angle α audior discussed that under the condition of multilayer structures the spreading angle will change.
Thermal resistance Border Effect Spreading angle Light-emitting diodes (LEDs)
Zhiling Ma Xueren Zheng
School of Physics, South China University of Technology, Guangzhou 510640, China
国际会议
上海
英文
1559-1561
2007-03-12（万方平台首次上网日期，不代表论文的发表时间）