A high-aspect-ratio copper microchannel cooling device for radar was fabricated on metallic substrate based on the electrochemical deposition technique. In view of the problem of non-uniform thickness in making thick film with high-viscosity SU-8 photoresist, lapping and polishing techniques were applied to the unexposed SU-8 film to improve the thickness uniformity and the dimension error caused by air gap was also reduced. A novel method to measure the thickness of unexposed SU-8 film using refractive index was proposed and the refractive index of SU-8 photoresist at yellow sodium light was obtained by least square method. In order to overcome the failure in making high-aspect-ratio SU-8 film due to inappropriate exposure dose, the effect of exposure dose on the quality of the film was discussed by lithography experiment and the optimal parameter was 640mJ/cm2. SU-8 film with good quality was acquired and a copper microchannel cooling device was fabricated based on the above techniques and experiment. The width is 50μm, the height is over 250μm and the aspect ratio is over 5.%基于电化学沉积技术在金属基底上制作了一种雷达用金属铜微通道散热器.针对使用高黏度SU-8胶制作高厚度胶膜时产生的胶厚不均匀问题,采用研磨抛光工艺处理未曝光的胶膜,提高了胶厚均匀性,成功解决了由于空气间隙大带来的尺寸偏差.提出了一种在曝光显影前利用折射率计算胶厚的方法,并通过最小二乘法确定了SU-8胶对钠黄光的折射率.针对高深宽比SU-8胶膜因曝光剂量选择不合适导致制作失败的问题,通过光刻试验分析了曝光剂量对胶膜质量的影响,确定了最优的曝光剂量为640mJ/cm2.在上述工艺和试验的基础上得到了质量良好的SU-8胶膜,并制作出了一种线宽50μm、高度大于250μm、深宽比大于5的金属铜微通道散热器,验证了该制作工艺的有效性.
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