热界面材料对LED车灯结温的影响

Study of the Influence of Thermal Interface Materials on the Junction Temperature of LED Lamps

随着LED芯片功率不断提高所导致的热流密度逐渐增大,结温成为影响LED芯片性能稳定性的关键因素。为有效降低结温,研究如何利用高效的热界面材料,提高芯片与热沉之间的传热。以实际LED车灯为研究对象,进行了不同导热系数热界面材料的性能测试和LED车灯结温试验,配比得到了导热系数较优的液态金属热界面材料。同时,利用计算机对所建模型进行了数值模拟仿真,仿真结果与试验结果相吻合,验证了所建模型与仿真方法的准确性。结果表明:混有铜纳米颗粒的液态金属铋基合金形成的热界面材料导热系数能够达到10.42 W/(m·K),通过降低芯片与热沉之间的接触热阻使LED结温降低了7℃。以上结果为今后LED芯片热界面材料的制备与选择提供了新思路。

As the heat flux density of the LED chip increases,the junction temperature becomes a key factor affecting the performance stability of the LED chip.In order to effectively reduce the junction temperature,it is studied how to use high-efficiency thermal interface materials to improve the heat transfer between the chip and the heat sink.Taking the actual LED lamp as the research object,the performance test of the thermal interface material with different thermal conductivity and the junction temperature test of the LED lamp were carried out,and the liquid metal thermal interface material with better thermal conductivity was obtained.At the same time,the numerical simulation of the model was carried out by computer.The simulation results were consistent with the experimental results,and the accuracy of the model and simulation method was verified.The results show that the thermal conductivity of the thermal interface material formed by the liquid metal bismuth alloy mixed with copper nanoparticles can reach 10.42 W/(m·K),and the junction temperature of the LED is lowered 7℃ by through reducing the contact thermal resistance between the chip and the heat sink.The above results provide a new idea for the preparation and selection of LED chip thermal interface materials in the future.