氮化鋁鎵/氮化鎵高電子移導率電晶體封裝熱分析

Abstract

氮化鋁鎵/氮化鎵高電子移導率電晶體(AlGaN/GaN HEMT)具有寬能隙(約3.4Ev)、高崩潰電壓、高臨界崩潰電場以及高電子飽和漂移速率、高峰值電子速率、高電子飽和速率等優點，因此適用於功率電子方面以及高頻通訊方面的應用。本研究針對AlGaN/GaN HEMT於功率電子元件之應用，因所需的功率及發熱密度較大，所以探討AlGaN/GaN HEMT封裝元件熱分析之重要性。分析在不同的封裝製程下，利用熱阻計算及ANSYS ICEPAK模擬以求得較佳的封裝製程方式。功率元件在電性操作下必定會有功率的損失，其損失的功率大部分會轉化成熱的形式經熱傳導由元件到封裝再以熱對流傳熱至外部環境。本研究先以IR紅外線熱分析、Raman光譜量測與IV Curve溫度曲線來實際量測封裝AlGaN/GaN HEMT在電性測試下之溫度分布及傳熱情形，並計算量測當下元件損失功率及元件效率，再以模擬結果與之驗證。由模擬的誤差、封裝型式的改良、量測方法的準確性，尋求更好的散熱途徑及封裝結構以提升封裝的功率散失及最佳的封裝熱管理。

AlGaN/GaN High electron mobility transistor(AlGaN/GaN HEMT) has many attractive material properties, such as wide bandgap(about 3.4 eV), high breakdown voltage, high critical breakdown field and high saturation electric drift velocity, high peak electron velocity, high electron saturation velocity and good thermal conductivity, which make it suitable for power electronics and Radio frequency (RF) communication applications. This study describes AlGaN/GaN HEMT for power electronic application. Therefore, the thermal analysis technology plays an important role in the high power and high power density packaging. First, use thermal resistance calculation and ANSYS ICEPAK simulation to analysis different packaging processes. Then, calculate the power loss and measure the temperature distribution of packaged AlGaN/GaN HEMT under the DC test by using three temperature measurement such as IR thermography microscope, Micro-Raman spectroscopy and IV-Curve electrical measurement. Finally, the simulation result is verified by compare it with experimental observations. Thermal simulation is used when designing a new device, in the design of the placement of the dissipating elements on the chip and for an efficient thermal management.