Simulation analysis and experimental verification of LIGA-like process for Ni-Fe micromold insert with taper angle

Abstract

The LIGA (a German acronym for lithographic, gavanoformung, abformung) (or LIGA-like) process involving lithography, electroforming, and molding is one of the most important microfabrication technologies for fabricating high-aspect-ratio 3-D microstructures. In this study we use CFX software to simulate the flow field in the micromold insert electroforming process and investigate the mass transfer effect, as well as the flow field and mass transfer for different taper angles and aspect ratios for a microtemplate under different flow speeds, in order to understand the effect of the geometrical shape of the template on the electroforming process, thus to obtain the optimum physical electroforming model. In this study, we will also perform a practical electroforming process at different aspect ratios and different taper angles of the microtemplate, in order to verify the results of the simulation. From the results of the simulation, it is found that the taper angle increases the speed of the plating solution at the vent, and a good equilibrium is achieved at a taper angle of 30degrees-45degrees. Since taper angle significantly affects the mass transfer effect, it can be used to increase the mass transfer effect in high-aspect-ratio and small holes. This result has been verified using a practical electroforming Ni-Fe micromold insert.