【作者】 郑辉；

【导师】 仇中军；

【作者基本信息】 天津大学 ， 仪器科学与技术， 2012， 硕士

【摘要】 随着微机电系统(MEMS)在微型光学、航空航天等领域不断发展,微型元器件的需求与日俱增,目前聚合物材料被认为是替代传统材料进行微型元器件加工的重要材料,而微注塑成型技术(μIM)是聚合物成型的关键技术之一,具有制造工艺简单,生产成本低,易于实现大批量自动化生产等优点。和传统注塑成型技术相比,微注塑成型技术面临的挑战主要是聚合物熔体在微尺度型腔中流动阻力增大,充模比较困难。本文提出将超声振动应用到微注塑成型过程中,利用超声能量降低熔体粘度,以超声场的作用去改善熔体流动行为及聚合物熔体冷却凝固时大分子结构的排列,从而达到在微小型腔顺利充模,提高微注塑成型质量的目的。本文在分析微注塑成型技术及超声波作用机理的基础上,自主开发了将超声波直接作用于聚合物熔体的微注塑成型模具系统,并以微光学系统元件菲涅尔透镜为成型目标,开展了超声波辅助微注塑成型工艺技术的研究。首先,利用正交实验法与仿真相结合的方法,对菲涅尔透镜塑件的微注塑成型参数进行了优化,同时进行了单因素实验模拟,分析了各注塑参数对塑件质量的影响规律;其次,利用自主开发的超声波辅助微注塑模具系统进行菲涅尔透镜的实际微注塑实验,考察了注塑过程中超声波对型腔中聚合物熔体流动性能和充模性能的影响,施加超声振动后透镜充模面积最大增大了17.3%;通过比较菲涅尔透镜表面形状精度,研究了超声微注塑在对菲涅尔透镜成型精度上的作用,结果表明,虽然超声波对于齿深和齿宽的改善程度不明显,但是却能明显改善菲涅尔透镜左右齿形的对称性,即熔体充填均匀性;最后,利用得到的最优微注塑工艺参数进行菲涅尔透镜的实际超声波辅助微注塑实验,验证了正交实验得到的最优工艺参数的准确性,实现了菲涅尔透镜的高质量微注塑加工。更多还原

【Abstract】 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.更多还原