大功率LED灯珠与散热器直焊结构散热效果分析

Heat Dissipation Analysis of High Power LED Connected to Copper Coated Heat Sink by Soldering

散热是制约大功率LED发展的瓶颈,为了更好地解决散热问题,采用新型冷喷涂技术,在铝合金散热器表面喷涂铜层,实现了LED灯珠与散热器的直焊,取代了目前使用导热硅胶等热界面材料压接的方式,有效地消除了压接产生的接触热阻,显著改善了散热效果。通过建立LED灯具的三维模型,采用CAE软件模拟和实验两种方法验证了LED灯具直焊结构的散热效果明显优于压接结构,并且随着LED输入功率的增大,直焊结构的散热优势更加显著。

Heat dissipation of high-power LED is the main bottleneck for its application.In order to better solve the heat dissipation problem,a new cold spray technology is applied to deposit thin copper coating which can make the soldering of LED head with heat sink possible,and this can significantly extend the durability of high-power LED lamp when comparing with current high-power LED lamp using crimped connection with thermal interface material,also can decrease the thermal contact resistance.Better heat dissipation performance of high-power LED has been verified by CAE software simulation and experiments.And with the increase of input power for LED lamps,the temperature difference of the LED chip between soldering and crimping structure also increases,the cooling effect of soldering is more significant.However,at present the thermal conductivity of the copper layer by cold spray is only 160 W/（m·K）,which has a great gap with the conventional copper＇s thermal conductivity 398 W/（m·K）,so the cold spray process needs to be further improved.