基于MEMS工艺的高能量密度微电磁驱动器

提出了制作高能量密度电磁驱动器的工艺方法。利用微机械(MEMS)工艺在硅片上得到多匝平面线圈和磁芯的掩模图形,接着沉积种子层铜(Cu),然后对种子层进行整体Cu的电铸;当种子层生长到20μm左右时,剥离硅片表面的镀层并用光刻胶保护磁芯位置的镀层;再用沿线电铸的方法对线圈进行电铸;最后保护制作好的线圈镀层,电铸NiFe合金材料。在10 mm×10 mm×0.38 mm的硅片上,制作出线圈匝数22×2(铜线截面积60μm×60μm、总长度达1 164 mm)、NiFe合金磁芯尺寸为3mm×3 mm×0.2 mm的高能量密度微型电磁驱动器。把这种微型驱动器应用于无阀微泵做驱动实验:通入0.3 A的正弦电流时,微驱动器产生约50 mN的电磁力。实验结果表明:这种型微电磁驱动器在相同的输入功率下,比同类其他微电磁驱动器具有更高的能量密度,能产生更大的电磁驱动力。

Fabricating a Micro Electromagnetic Actuator with High Energy Density

This paper introduces a new technology to fabricate a micro electromagnetic actuator with high energy density without an enclosed magnetic circuit. This technology includes fabricating multi-turns planar micro coils and fabricating the thick magnetic （NiFe） core on the silicon wafer. The multi-turns planar micro coils are fabricated by the electroplating method from the surface along the line and by dynamically controlling the current density of the copper electrolytes. In order to fabricate thick NiFe plating,the adhesion properties between the NiFe plating and the silicon substrates are improved by changing the surface roughness of the silicon substrates and increasing the thickness of the seed layer. Furthermore,the micro electromagnetic actuator is tested and the energy density of the actuator is evaluated by force testing. The experiments show that the microactuator is efficient in producing high magnetic energy density and high magnetic force.