Electromagnetic embossing of optical microstructures

电磁压花是一种很有前途的高速复制功能微结构和光学微结构的工艺。对于铝箔的压花，它具有不同的优点，如非接触式工作容积力和省去了像滚动油这样的润滑剂。特别是对于微结构的压花，由于提高了复制精度，增加的可塑性是有益的。由于工艺机制和物理效应的相互作用对材料行为的影响仍部分未知，目前还不可能对光学微结构的电磁压花进行工艺控制。因此，BIME和LFM研究所的这一联合研究项目将侧重于通过电磁压花复制大面积功能和光学微结构，目的是获得有关基本工艺机制的确凿知识。在此背景下，对材料流动与工艺参数的关系进行了实验研究，确定了一组与工艺参数相关的流动曲线。建立了模拟模型，将影响材料流动的物理效应可视化，并将流动曲线与主要机理及其相互作用关联起来。此外，电磁和机械负载的发生都需要定制的压花工具。因此，将开发和研究由选定的基材和涂层组成的不同制造策略。不同的载荷对不同结构类型和表面的压花质量的影响将通过实验来确定。这包括微结构在高冲击载荷下的行为。除了可达到的表面质量外，还将分析工具的轮廓偏差和压花微结构。这些发现的结果将是工具设计的战略。在总体研究成果的基础上，建立了面向应用的系统工艺规划模型和方法，并通过示范压花实验进行了验证。

Electromagnetic embossing is a promising high speed process for the mass reproduction of functional and optical microstructures. For embossing of foils it offers different advantages such as a contactless working volume force and the omission of lubricants like rolling oil. Especially for embossing of microstructures the increased plasticity is beneficial due to an increased replication precision. As the influence of process mechanisms and interactions of physical effects on the material behavior is still partially unknown, a process control of the electromagnetic embossing of optical microstructures is currently not possible. This joint research project of the institutes bime and LFM will therefore focus on the replication of large-area functional and optical microstructures via electromagnetic embossing, with the aim of obtaining a substantiated knowledge of the underlying process mechanics. In this context, the material flow with respect to the process parameters is experimentally investigated and a set of parameter dependent flow curves is determined. A simulation model is set up to visualize the physical effects that influence the material flow and to correlate the flow curves to main mechanisms and its interactions. Furthermore, the occurrence of both electro-magnetic and mechanical loads requires a customized embossing tool. Thus, different manufacturing strategies comprising selected base materials and coatings will be developed and investigated. The influence of varying loads on the embossing quality of different structure types and surfaces will be determined experimentally. This includes the behavior of the microstructures under high impact load. Besides the achievable surface quality, the contour deviations of the tools and the embossed microstructures will be analyzed. A strategy for the tool design will be the outcome of these findings. Based on the overall achievements an application-oriented model and a method for a systematical process layout will be set up and verified against exemplary embossing experiments.