奈米材料應用於高功率發光二極體固晶散熱研究

Applications of Nanomaterials to Die Bonding and Thermal Dissipation of High Power Light Emitting Diodes

洪家偉(Jia-Wei Hong)

指導教授 ： 甘廣宙

共同指導教授 ： 陳耀煌(Yaw-Huang Chen)

崑山科技大學/工程學院/電子工程研究所/碩士(2010年)

摘要

發光二極體(Light Emitting Diode，LED)是一種具有節能減碳機能的綠能產品，跟傳統光源比較具有省電及壽命長等優點，相對於高功率LED而言，高功率LED是一種發熱密度高的元件，其發熱能量遠遠高於低功率LED。另一方面由於LED受到晶粒面積小的影響，因此使高功率LED發熱密度非常高，因高功率LED的熱大部份都集中在P-N接面上，導致LED元件過熱，過熱會影響高功率LED波長漂移與光學特性衰減，且LED元件過熱，也會造成元件的熱膨脹係數不穩，會使元件間負荷過高機械應力而毀損。故本論文透過使用奈米碳管和碳化矽來改善LED元件過熱的問題，由於奈米碳管和碳化矽兩者的熱導率分別約3000~6000 W/m．K和300~380 W/m．K，因此本研究將奈米碳管和碳化矽摻雜並混於環氧樹脂(Epoxy)內改善LED P-N接面的接面溫度。
結果顯示︰利用奈米碳管和碳化矽摻雜混於Epoxy並藉由順向偏壓法量測接面溫度可得知:環氧樹脂(Epoxy 123℃)、Epoxy+ SiC (50wt%, 99℃)、Epoxy+CNT/SiC (30wt%，93℃)，藉由量測得知奈米碳管/碳化矽摻雜混於Epoxy的元件接面溫度能改善30℃。與Epoxy相比能降低溫度24%。

關鍵字

高功率發光二極體 ； 奈米碳管 ； 碳化矽

並列摘要

Light-emitting diode (LED) is a function of energy-saving green energy and carbon reduction products, which can save more power and have longer life than the traditional light source. However, the high power LED is a lighting component of high heat generation, producing much larger heat than the traditional LED under high illumination. On the other hand, the LED by the small size of grains, thus making high-power LED heat density is very high, because of high power LED hot most of the surface are concentrated in the P-N junction, resulting in LED components overheating, overheating will affect the high-power wavelength shift with the optical characteristics of LED degradation, and the LED components overheating, will result in coefficient of thermal expansion of components is not stability, high mechanical loads between components will stress the damage.
Therefore, this thesis is to improve the junction temperature of LED die attaching by using carbon nanotubes and Silicon Carbide. As both carbon nanotubes and silicon carbide thermal conductivity is about 3000 ~ 6000 (W /m•K) and 300 ~ 380 (W /m•K), so this study used carbon nanotubes and silicon carbide doped within the epoxy resin to resolve the thermal conductivity problem of LED for junction temperatures.
In this experiment, measuring the junction temperature using forward bias voltage can see that the Epoxy is about 123℃, epoxy doped silicon carbide is about 99℃ and Epoxy doped COOH-CNT/SiC is about 93oC.From above the data that carbon nanotubes doped in epoxy device that significantly reduces the junction temperature of high power LED is 30℃. Such device improved the thermal dissipation of high power LED by up to 24%.

並列關鍵字

HB-LED ； CNT ； SiC

參考文獻

[35] 林彥文，聚苯胺/奈米碳管導電複合材料之製備與電性研究，2004年。

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