功率型LED封装基板材料的温度场和热应力分析

Analysis on the Temperature Field and Thermal Stress of Power Type LED Package Substrate

建立了功率型LED的有限元热学模型,选择Al2O3,AlN,Al-SiC,铜钼合金四种基板材料,采用ANSYS热分析软件仿真不同基板材料的温度场和热应力分布,得出如下结论:AlN基板的结温和热阻最低,结温达到120℃时所加的热载荷值最大;最大热应力主要集中在芯片与基板的界面附近,AlN基板的最大热应力最低。因此,AlN材料是较理想的基板材料。

A finite element thermal model was established for power type LEDs.Four kinds of substrate materials of Al2O3,AlN,Al-SiC and copper-molybdenum alloy were selected.Temperature field and thermal stress distribution of different substrate materials we analyzed with ANSYS software.It is concluded that AlN substrate has the lowest junction temperature and thermal resistance,and the added heat load value reaches the maximum at the junction temperature of 120 ℃;the maximum thermal stress mainly concentrates in the chip and the substrate interface,AlN substrate has the lowest maximum thermal stress.Therefore,AlN is an ideal substrate material.