Injection Molding Microfeatures

本研究项目的目的是开发一种新的技术，成功的微注塑成型方面的周期时间较短，更好的复制相比，现有的技术。这将通过快速加热模具表面来实现，使得熔体可以等温地填充型腔，并且在正常的注塑成型周期时间内进行处理。 到目前为止，塑料在价值数十亿美元的微系统工业中只扮演了次要角色。 商业上的突破强烈依赖于具有尺寸精度和良好零件质量的低成本大规模制造的手段。然而，广泛使用的涉及聚合物材料的大规模生产方法，如注射成型，需要进行重大修改，以适应微成型应用。 限制微注射成型中的当前技术能力的障碍之一是微小腔中的熔融聚合物在接触相对冷的腔壁时瞬间冻结。当要模制具有较高纵横比的微特征时，问题变得更糟。三个阶段的研究计划包括一个实验部分，致力于创建一个灵活的微成型夹具，第二阶段将进行加工实验与几种热塑性塑料，最后一个阶段将是微尺度流动行为的表征，这种微注塑成型过程。该研究项目还将产生关于微观现象对聚合物材料流动行为的影响的急需的实验数据。预计集成技术的发展将推动目前的微注塑成型技术进一步进入那些迄今为止由蚀刻和光刻为基础的制造占主导地位的领域。这可以导致结构设计部件的3D微制造。

The objective of this research project is to develop a novel technology for successful micro injection molding with respect to lower cycle time and better replication as compared to the existing technology. This will be accomplished by rapidly heating the mold surface so that the melt can fill the cavity isothermally and yet be processed within the normal injection molding cycle time. Plastics have so far played only a subordinate role in the multibillion-dollar microsystem industry. A commercial breakthrough strongly depends on means of low cost mass fabrication with dimensional accuracy and good part quality. Widely used mass-production methods involving polymeric materials such as injection molding, however, require significant modification to adapt to micro molding applications. One of the hurdles limiting the current technical capability in micro injection molding is that the molten polymer in a tiny cavity instantaneously freezes upon contacting the relatively cold cavity wall. The problem gets worse when micro features with higher aspect ratio are to be molded. The three phase research plan includes an experimental component devoted to creating a flexible micro molding fixture, the second phase will be to conduct processing experiments with several thermoplastics, and the final phase will be the characterization of micro scale flow behaviors for this micro injection molding process. This research project will also yield much needed experimental data regarding the effect of microscale phenomena on the flow behavior of polymeric materials. It is expected that development of the integrated technology will push the current technical envelope of micro injection molding further into those areas that have so far been predominated by etching- and lithography- based fabrications. This can lead to 3-D microfabrication of structurally designed parts.