Fabrication of micropattern of plastic film using ultrasonic micro embossing

This study indicates the micropattern of molded plastic film from a mold insert using ultrasonic micro embossing. A mold insert and plastic film are heated above the glass transition temperature of plastic, and the softened plastic is flowed into the micropattern of a mold insert by applying pressure via a conventional technique. A longitudinal ultrasonic wave is added to the ultrasonic micro embossing process. The longitudinal ultrasonic wave generated by an ultrasonic system at a frequency of 35 KHz, has amplitude of 20 μm and output power of 900 W. The micropatterns of the Ni mold insert are groove-shaped and they are 2-μm wide and 200-nm deep. The Polypropylene (PP) is chosen as the replication materials. This study identifies the replication properties of the plastic film using different process parameters (working pressure, ultrasonic pressure, packing pressure, working time, ultrasonic time and packing time). Results of this study demonstrate that ultrasonic time is the most important process parameter for ultrasonic micro embossing.