阳极氧化铝基板的制备及在LED散热领域的应用

Preparation of Anodic Alumina Substrate and Its Application in LED Heat Dissipation

利用阳极氧化技术制备了普通阳极氧化铝基板,并在此基础上结合图形转移的方法制备出了选择性阳极氧化铝基板。借助电镜扫描并通过冷热循环冲击试验对铝材与阳极氧化膜界面处在高低温突变情况下的界面形貌进行了分析。利用结温测试仪、积分球系统、功率计、半导体制冷温控台等仪器设备,通过结温及热阻测试对比研究了两种铝基板与普通MCPCB(Metal Core PCB,金属芯印刷电路板)对LED模组散热效果的影响情况。结果表明,两种基板在经低温-55℃,高温125℃,1000次冷热循环后,氧化膜无裂纹滋生,氧化膜与铝材界面结合完好;对于驱动功率为3 W的LED灯珠,普通MCPCB、普通阳极氧化铝基板与选择性阳极氧化铝基板所对应的芯片结温分别为46.5℃、42.03℃和38.52℃,对应模组的热阻则分别为9.29℃/W、7.49℃/W和5.85℃/W。

The regular anodic alumina substrate was prepared using anodization technique, and the selective anodic alumina substrate was also fabricated in the same way with the application of graphic transfer technique. The microscopic morphology of interface between anodic oxide film and aluminium alloy under the condition of sudden temperature change has been studied by thermal shock test using scanning electron microscope. A comparison of heat dissipation effect between these anodie alumina substrates and MCPCB in LEDs＂ application has also been researched using junction temperature tester, integrating sphere system, power meter and semiconductor refrigeration temperature control platform. As a result, it has been found that when the temperature went from -55 ℃ up to 125 ℃, no crack happened in the Anodie oxide film and the interface between anodic oxide film and aluminium alloy exhibited a sound combination after 1000 cycles, suggesting a good bonding strength on the condition of drastic temperature change. Meanwhile, as for the LED with 3 W driving power, the junction temperatures were 46.5 ℃, 42.03 ℃ and 38.52 ℃, and the thermal resistances were 9.29 ℃/W, 7. 49 ℃/W and 5.85 ℃/W when the traditional MCPCB, regular anodie alumina substrate and selective anodic alumina substrate came into use respectively.