The micro acceleration switch is an important inertial device for measuring itself acceleration and triggering switch in a flight control system. A micro spiral acceleration switch was fabricated in this paper by using UV-LIGA technology combining with SU-8 thick resist process

micro electroforming and sacrificial layer technology. The fabrication processes of the microstructures

such as sacrificial layer technology

SU-8 lithography and the distortion control of spiral spring structures

were studied in detail. The properties of various sacrificial layer materials were analyzed and the Zn film was chosen as a sacrificial layer to avoid the desquamation of microstructures. The flat spiral spring and mass block structures were obtained by optimizing the electroforming parameters to minimize the inner stress of Ni microstructures and controlling the releasing process of sacrificial layer to avoid the impact of chemical reaction on the Ni spiral films. The obtained spiral spring and the mass block show their thicknesses to be 20 μm and 200 μm

respectively. The result indicates that it is reliable to produce micro spiral acceleration switches in batches by using this fabrication process.