LED车灯风冷散热器基板与肋片结构的优化设计与性能分析

Optimal Design and Performance Analysis of Air-Cooled Radiator Substrate and Fin Structure for LED Headlights

摘要: 增强LED车灯的散热性能是避免其热失效的关键措施，为提升LED车灯风冷散热器的性能，本文构建了一系列变结构模型，研究了基板厚度、肋片间隙和肋片形状对散热器性能的影响。结果表明，增加基板厚度可以提高散热器散热性能，但基板厚度增至3.5 mm以上时，其对芯片结温的降低效果有限。适当减小肋片间隙可以提升散热性能，但当间隙降至1.3 mm以下时，由于经过肋片区域的强制气流流量明显减少，散热性能反而减弱。同时，本文还设计了包括凸形、凹形、波浪凸形、波浪凹形和倾斜形的五种散热器肋片，它们均有助于芯片结温的降低，其中采用40˚倾斜形肋片的散热器效果较佳，能使芯片结温降低6.3℃。

Abstract: To enhance the heat dissipation performance of LED headlights is the key problem to avoid thermal failure. In order to improve the performance of LED headlights air-cooled radiator, a series of variable structure models are constructed in this paper, and the effects of substrate thickness, fin clearance and fin shape on the performance of the radiator are studied. The results show that increasing the thickness of the substrate can improve the heat dissipation performance of the heat sink, but when the thickness of the substrate increases to more than 3.5 mm, the effect of reducing the junction temperature of the chip is limited. Properly reducing the fin clearance can improve the heat dissipation performance, however, when the clearance is lower than 1.3 mm, the heat dissipation performance is weakened due to the obvious reduction of forced air flow through the fin area. At the same time, five kinds of heat sink fins are designed in this paper, including convex, concave, wavy convex, wavy concave and inclined, which all contribute to the reduction of chip junction temperature. The heat sink with 40˚ inclined fin has the best effect, which can reduce chip junction temperature by 6.3˚C.