- 學位論文
LED陶瓷基板之熱模擬與分析
Thermal Simulation and Analysis of LED Ceramic Substrate
摘要
在LED 燈具逐漸取代傳統照明燈具的現在，不管是室內或是戶外的照明，往高功率的發展為現今的主流趨勢，因此在LED模組中對於散熱能力的要求也越來越高，越來越嚴苛。本文對於在LED模組中，選擇適用於高功率LED的陶瓷基板，以有限元素法的CAE模擬分析軟體ANSYS Workbench的穩態熱模擬，模擬陶瓷基板在使用狀況下時的各項熱性質，並以三種常見的陶瓷基板類型，分別是Al2O3、Si、AlN，以及二種不同的鍍膜Al、Cu與一種高熱傳導係數之類鑽薄膜來探討，在改變不同的基板及鍍膜材質，與鍍膜厚度等的設計參數下，紀錄基板整體的熱傳導係數與熱性質之變化。藉由模擬後所產生之現象，再以紅外線量測儀量測實際鍍銅基板於使用下之溫度場分布，來驗證模擬值是否正確，以縮短將來設計散熱基板產品時的時程，目前可以整理以下幾點結論: 1.鍍膜厚度增加與基板整體的等效熱傳導係數的提升成正比，因為薄膜厚度的增加，加強了熱量於薄膜上的橫向熱量傳遞，使熱能順利往邊緣擴散，分散降低中央熱源之溫度。 2. 當鍍膜厚度持續上升時，整體的等效熱傳導係數會越來越接近鍍膜之熱傳導係數。但當其等效熱傳導係數接近鍍膜熱傳導係數的最大值後，再增加膜厚會使熱阻上升。 4.實際量測130μm鍍銅氧化鋁基板溫度與模擬溫度，溫差最小為0.061℃，最大為1.5℃。
並列摘要
In this time, LED lighting is gradually replace traditional lighting, either indoor or outdoor lighting,are all to development of high power LED. The cooling capacity requirements of LED is higher and higher, and increasing more stringent. This document simulate the ceramic substrate that we use for high-power LED, with the finite element method software ANSYS Workbench. We simulate steady-state thermal simulation with ceramic substrate .And find the thermal properties of it. The ceramic substrate with three common types, namely, Al2O3, Si, AlN, and two different coating Al, Cu and a high thermal conductivity of diamond films, under different substrate and coating materials and coating thickness chang. We record thermal conductivity and other thermal properties change. Compare the temperature by simulation and the actual measure temperature that measured by infrared measurements, to verify the simulation value is correct or not. This document is for shorten the time of design substrate products in the future.After the simulation and analysis, we can order the following conclusions: 1. Coating thickness is proportional to the substrate’s thermal conductivity. When the Coating thickness increase, it also increase the Horizontal heat transfer on the film. It can makes the heat spread to the edge smoothly, and lower the temperature of the central heat source. 2. When coating thickness increase, it allow the overall thermal conductivity of the substrate close to the film’s thermal conductivity. But when the overall thermal conductivity arrive the maximum, additional coating thickness will increase thermal resistance. 3. Difference between temperature that measured by infrared measurement and the the simulated temperature is about minimum 0.061℃ on the central of the substrate and the maximum 1.5℃ on the edge.