Optimization of plasma surface modification parameter for fabricating a hot embossing mold with high surface finish

摘要

Hot embossing is a low-cost processing approach for polymer-based microfabrication. However, the time and cost are two major problems in the mold industry to produce a precision hot embossing mold with high surface finish for the pilot run in the new product development phase. This study investigates the optimum process parameters of plasma surface modification to fabricate a precision micro-hot-embossing mold without the use of release agent. The first silicone rubber mold with the lowest surface roughness can be utilized for fabricating a precision hot embossing mold using rapid tooling technology. It was found that the dominant factor affecting the surface roughness of the first silicone rubber mold is the plasma-arc distance. The optimum process parameters to fabricate a hot embossing mold with high surface finish are plasma power of 70 W, treatment time of 3 min, gas flow rate of 25 sccm, and plasma-arc distance of 40 mm. The replication rates for depth and width of the fabricated Al-filled epoxy resin mold about 92.4 and 98.1% can be obtained using the optimum process parameters. The improvement rate of the surface roughness of the fabricated Al-filled epoxy resin mold about 39.4% can be reached.