Fabrication of Plastic Micro Features on Microporous Mold by Hot Embossing

Abstract

The method of using ultrasonic heating to aid high precision moulding of micro features has been studies. The study developed a method of using ultrasonic vibration to heat the polymer and hot embossing high precision micro features. A commercial ultrasonic welding machine is converted to provide the heating of polymer and mold then into precision micro features for study of ultrasonic heating and the microflow of polymer under ultrasonic agitation. A stainless steel microporous mold of 200µm thick with through holes of 50µm and 200µm in diameter were used. Using a frequency of 35kHz, the microflow behavior of PC (Polycarbonate) and PE (Polyethylene) in the microchannels were investigated. The differing properties of microflow for these two types of polymer give indication on the theoretical and practical agreement on prediction of microflow under ultrasonic energy.

Design optimization and experimental verification of ultrasonic stack for micro hot embossing of polymers

“…Ultrasonic hot embossing (UMHE) is primarily suitable for thermoplastic polymers due to their responsiveness to heat and pressure. Common thermoplastics can be processed using UMHE include but are not limited to polystyrene (PS), polyethylene (PE) [12], polypropylene (PP), polyvinyl chloride (PVC), polyethylene terephthalate (PET) [13], polycarbonate (PC), and poly methyl methacrylate (PMMA) [14]. These polymers exhibit the necessary properties for successful embossing, such as melt flow behavior and compatibility with ultrasonic energy.…”