The Study On The Fabrication Of The Polymer Microsructure By The UV Curable Method

Since the polymer material has the advantages of low price and excellent physical and chemical properties, which shows a huge commercial prospect in the micro machining field especially in microfluidic chip, micro-reaction device and micro-optics lighting device. However, the light curing method of stamping technology enables to rapid prototyping of micro-nano structure under the low pressure of the products, owning the incomparable advantage over other methods. So the photo-curable embossing technology becomes a research hot spot in micro machining in recent years. In this paper, for the purpose of making micro and nanoscale polymer array components, a rather systematically study of the photo-curable micro or nano-stamping process has been made.This paper calculated that the UV glue droplets in the compression process mainly spreads in laminar flow state and the speed of the micro or nanostructure forming is mainly determined by curable time of the UV resin rather than the extremely short filling time.The fluid flow analysis model of gas-liquid mixing multiphase called VOF has been established and an effective contact angle zone benefit to filling of the UV resin has been summarized and concluded.The UV glue liquid and the mold to keep smaller acute angle, with an obtuse angle to the substrate, can help the UV liquid fill ing. Increasing the supply of liquid and the surface tension coefficient are beneficial to the improvement of the fill rate, while increasing the high aspect ratio (HAR) of microstructure has an opposite effect on the liquid filling rate.A cohesion zone model on the basis of elastic fracture mechanics has been firstly made. From the simulation results, we can divide demolding process into two stages:energy accumulation on the top of the microstructure until it was divided and the friction and shear of the mold wall during the release. An obviously tress concentration was found in the sharp corner of the contact area between the microstructure wall and mold, one of which on the bottom was most easily damaged.The strong shear effect caused by the friction possesses larger proportion of the increasing local stress and cannot be ignored.Subtle sidewall angle and high elastic modulus is conducive to guarantee the success of demolding.Finally the "Roll-to-Plate" (RTP) of imprinting method,also called "Roller Press Scan", was used to successfully prepare the large area film about 200mm2 containing nano moth-eye structures, which has good anti-reflective (AR) effect. The reflectivity of AR product was only 1% between the wavelength 450-600 nm, and the transmission rate of thin film covered with nano structure on double-side can reach 98.3%. The background covered with AR film has excellent color reducibility and improves the resolution of display, which can be comparable to the commercial antireflective coating products.At the same time, the influence of different process conditions on nano structure size has been studied. Keeping the "high pressure and medium speed" parameter settings window of the UV embossing device can get better products with rather uniformity dimension.This paper firstly puts forward concept called consecutive dispensing process by point and point using the RTP stamping process, which can simplify the UV glue coating process and improve the efficiency of the microstructure forming. It will provide new thought for achieving scale production of the polymer devices with micro-nano structure.