Fabrication of low-cost capacitive accelerometers by 3D microforming

A capacitive accelerometer has been manufactured by combining the 3D Microforming process with a sacrificial layer technique. The entire structure of the sensor element was first grown electrochemically within the patterned resist on an electroplating base composed of rigid and sacrificial metal layers. Its movable parts were then obtained by removing the sacrificial layer using wet etching. This fabrication process employs no expensive equipment and avoids high processing temperatures. Sensors of a structural height of up to 40 /spl mu/m with an aspect ratio of 6 can be easily realised with this simple, economical, yet highly reliable method. This paper describes this low-cost microstructure technology which could be also applied to economically realise other micro elements with oscillating structures.