Browsing by Author "Fu, MN"

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Simulation analysis and experimental verification of LIGA-like process for Ni-Fe micromold insert with taper angle
(2004-11-01)
Fu, MN
;
Yeh, YM
;
Tu, GC
;
材料科學與工程學系
;
Department of Materials Science and Engineering
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.
Simulation analysis and experimental verification of UV-LIGA process for high-aspect-ratio Ni-Fe micro-mold insert
(2003-10-01)
Yeh, YM
;
Tu, GC
;
Fu, MN
;
材料科學與工程學系
;
Department of Materials Science and Engineering
UV (ultra violet)-LIGA (a German acronym for lithographic, gavanoformung, abformung), a low-cost microcomponent manufacturing technology for micro-electromechanical systems (MEMS), combines the UV patterning of thick photoresist layers with the molding of the resulting patterns by electroforming. It enables mass production of microcomponents using microinjection molding or hot embossing technology. This paper addresses the characteristics of the flow field and the mass transfer effect during micro-electroforming processes. A micro-electroforming experiment is conducted and a simulation is performed to determine optimal conditions for fine surface forming by micro-electroforming. Results show that a smaller diameter of a hole corresponds to poorer plating bath transfer. Plating bath can be replenished by increasing the rotation speed of the electrodes. However, mass transfer is still limited in holes with a high aspect ratio. The theoretical results of simulation analysis were verified by conducting practical electroforming experiments.