大功率LED的封装及其散热基板研究

Package and MCPCB for High-power LEDs

从解决大功率发光二极管散热和材料热膨胀系数匹配的角度,介绍了几种典型的封装结构及金属芯线路板(MCPCB)的性能,并简要分析了其散热原理。最后介绍了等离子微弧氧化(MAO)工艺制作的铝芯金属线路板,低成本、低热阻、性能稳定、便于加工和进行多样结构的封装是其突出优点。对采用MAO工艺的MCPCB基板封装的瓦级单芯片LED进行了热场的有限元模拟,结果显示其热阻约为10 K/W;当微弧氧化膜热导率由2 W.m-1.K-1升高到5 W.m-1.K-1时,热阻将降至6 K/W。

From the point of view of solving the heat dissipation and the matching between heat expansion coefficients of the materials for high power LEDs,the package structure and the performances of several types of metal core printed circuit board（MCPCB） have been presented in detail as well as a brief analysis on the conception of heat dissipasion.A special MCPCB fabricated by plasma electrolyte oxidation（PEO） is introduced,which is characterized by low cost,good electrical isolation,excellent thermal transfer and its convenience for package processes. And finite element method （FEM） has been used to simulate the temperature distribution in watt-level single-chip LED model. The results show that the thermal impedance of the LED devices reduces from 10 K/W to 6 K/W when the thermal conductivity of the plasma microarc oxidation （MAO） film rises from 2 W·m^-1·K^-1 to 5 W·m^-1·K^-1.