DEVELOPMENT AND TESTING OF A LOW-COST RAPID-CYCLE HOT EMBOSSING SYSTEM FOR MANUFACTURING MICROSCALE PARTS

摘要

Hot embossing is an effective technology for replicating micro-scale features in polymeric materials, but large-scale adoption of this method is hindered by high capital costs and longer cycle times relative to other technologies. This paper details a hot embossing machine design strategy motivated by maximum production speed with minimal capital cost. Innovative design aspects include the choice of new ceramic substrate heaters for electrical heating, design of a moveable heat sink to minimize heat load during the heating cycle, and the careful design of the thermal elements to minimize the heating and cooling cycle times. The hot embossing equipment fabricated from this design has a capital cost estimated to be an order of magnitude less than currently available options. The minimum cycle time is two minutes, and microstructures are replicated within a maximum area of 25mm by 75mm. The hot embossing machine has been tested to characterize the process variability. Runs of polymethylmethacrylate (PMMA) parts manufactured using this equipment are measured to have submicron variation under a variety of processing conditions.