基于微电铸工艺的镍微型惯性开关的研制

Development of Nickle Micro Inertial-switch Based on Micro Electroforming Technology

为满足安全气囊辅助系统对信号识别的可靠性要求,采用UV-LIGA叠层光刻和精密微电铸工艺在不锈钢基底上制作了一款轴向触发的镍微型惯性开关,其利用阿基米德螺旋梁结构来支撑悬空质量块,中心止挡柱作为螺旋梁过载保护结构,开关敏感方向垂直于衬底的方向。在制作过程中,引入了掩膜版线宽误差补偿的方法,降低了因胶膜溶胀与无机酸去胶等工艺带来的尺寸误差,通过煮沸的无机酸去除胶膜得到了结构完整的开关。最终制作出了整体尺寸为3850μm×3850μm×240μm、最小线宽尺寸为40μm的开关,并通过落锤试验对开关进行动态特性测试。

In order to meet the reliability demands for the signal recognition of the airbag restraint systems,an axially-driven metal micro inertial-switch was designed and manufactured on a steel substrate by using UV-LIGA multilayer photolithography and precision micro electroforming. The proof mass of the switch was supported by Archimedean spiral beams,a circular limited post was set as the overload protection structure of the spiral beams,and the direction of switch is perpendicular to the substrate. In the fabrication,the method of size error compensation was introduced to reduce the error caused by photoresist swelling and releasing. The whole structures of switch were obtained by using the method of boiling inorganic acid to remove the photoresist,finally an overall dimension of the switch is 3850 μm×3850 μm×240 μm of which the smallest line width is 40 μm. At last,the the property of switch was tested by dropping hammer experiment.