Analysis of the Effect of UV-LIGA Fabrication Error on the Microspring Elastic Coefficient

The manufacturing process of planar microsprings by the UV-LIGA process was introduced; the mechanism of fabrication error was analyzed from three process stages of exposure, SU-8 swelling, and corrosion; and the corresponding improvement measures were proposed. The line width of two groups of microsprings after the exposure, SU-8 swelling, and debonding was measured, and the elastic coefficients in three coordinate directions were accurately measured. The results show that the factors that affect the line width error are stable. The effects of the exposure diffraction, swelling of SU-8 glue, and debonding corrosion process on the line width size follow the order: corrosion error > swelling error > exposure error. When the line width is small, the aspect ratio of the microspring is large, and the direction of machining error is generally negative. The relative error of the elastic coefficient of microsprings in three coordinate directions is larger. The influence rule of the line width error on the elastic coefficient follows the order: kerrory > kerrorx > kerrorz.