大功率LED的热阻计算方法(英文)

Thermal Resistance Calculation Method of High-power LEDs

在设计的早期,对大功率发光二极管的热阻进行估算对于实行有效的热管理非常重要。提出的热阻计算方法基于热的定角度传播,考虑了边界效应,得到了覆盖芯片尺寸和衬底厚度条件的热阻精确解。假设LED封装的侧壁是绝热的,底部被连接到热沉。为了保持模型连续,使用一个自定义函数来代替原始模型的分段函数。热阻计算公式的最后表述适用于各种边界条件,并对不同材质的界面处传播角度的变化进行了讨论。

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. The method present 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. The sidewalls and the top of the LED package are assumed to be adiabatic with the bottom surface bonded to the heat sink. A special function is used to replace a segmented 4, function to keep the model continuous. The final expression of thermal resistance calculation for circular chip is consistent for all the border parameters. After the model of circular power dissipation element of radius r on a substrate of thickness h is derived, with a heat-spreading angle α , author discussed that under the condition of multilayer structures the spreading angle will change.