X波段GaAs功率芯片共晶焊热应力分析

随着电子封装集成度的不断提高，电子芯片的功率容量和发热量也越来越大，封装体内部温度分布不均以及产生的热应力影响芯片的可靠性.热沉作为电子设备主要的散热方式之一，被广泛使用.利用ANSYS有限元软件针对芯片-共晶层-热沉结构进行建模，通过有限元3D模型模拟该封装结构在热循环温度-55~125℃条件下产生的热应力情况，研究了采用不同热沉材料共晶焊的应力.结果表明，该结构封装的最大应力出现在热沉下表面的4个拐角处.钨铜为热沉结构时应力值最大，AlSi50次之，AlN最小.研究结果对X波段功率模块封装设计提供了设计依据.

Analysis of eutectic soldering thermal stressin X-Band GaAs power chip

With the increasing integration of electronic packaging, electronic chips power capacity and heat power is also growing, encapsulation body internal temperature distribution and thermal stress have the influence on the reliability of the chip. The heat sink is one of the major cooling methodfor electronic equipment. By using ANSYS finite element software, 3D finite element model was founded for chip-eutectic layer-heat sink tosimulate package thermal stressin -55~125℃ in the thermal cycling, and the eutectic welding stresswas studied at different heat sink materials. The results showed that the maximum stressin the encapsulation structure appears in the heat sink on the surface of the four corner. The heat sink materials with the thermal stress from high to low in order are tungsten copper, AlSi50 and AlN. The results of the study provide a design basis fordesignment of X-band power module package.