Methodology And Technology For Ultrasound-assisted Micro Injection Molding

As the rapid development of MEMS technology in micro-optics, aerospace and other fields, the demand of micro devices is increasing. Polymer material is considered as an important material to substitute traditional materials for micro products currently, and micro-injection molding technology (μIM), is one of the key technologies in forming polymer. The advantages ofμIM are simple to manufacture, low cost, easy to implement mass production and automated production and so on.Compared with conventional injection molding techniques, the main challenge ofμIM is polymer melt filling difficultly in small cavity. In order to solve this problem and to improve the quality of micro-products, the technology of ultrasound-assisted in micro-injection molding process is studied. The ultrasonic energy is used to reduce the melt viscosity, and to improve the melt flow behavior in filling as well as the structure after solidification.According to micro injecting molding technology and the action principle of ultrasound, an ultrasound-assisted micro injection mold which the ultrasound is exerted on the polymer directly is designed. First, based on orthogonal experiment and simulation result, the influences of technological parameters on the molding quality were discussed. Second, in order to verify effect of ultrasound-assisted micro-injection molding, an ultrasound-assisted micro-injection molding for Fresnel lens was launched, the experimental results showed that the mould filling capability of micro injection molding had been improved by about17.3% with the same injection parameters, and the structure of Fresnel were more uniformity. Finally, obtained results showed orthogonal experiment was credibility for gaining optimization parameters, and high quality micro-Fresnel lens molding processing was achieved by ultrasound-assisted micro-injection.