ISBN 9783868539271

978-3-86853-927-1, Reihe Produktentwicklung

Dima Straube
CAD-Features für die Entwicklung von Mikrosystemen

147 Seiten, Dissertation Technische Universität Braunschweig (2010), Softcover, A5

Zusammenfassung / Abstract

While printing caused a considerable increase of spread of knowledge, the introduction of computer technology stands for a strong spread of information. For the engineering design process, this means a strong increase of relevant information and an increased complexity of the design solution. The feature technology can automatically relate information to each other. Information elements with a higher quality are created, which can be used by the engineer to decrease the complexity in the design process. This approach will be used in the presented work for the development of so-called CAD features. A CAD feature is an aggregation of a form feature and an application feature. The application feature contains technical and functional properties which are related to the geometric properties of the form feature. While the feature technology is used in many parts of the design process of the mechanical engineering, this is still not the case in the development process of MEMS.

The results presented in this work are an integral part of a modular computer-aided development environment for active MEMS, which is being developed within the scope of the collaborative research project SFB 516 „Design and Fabrication of Active Microsystems“. The developed software modules focus on the aspects which are important to MEMS, namely the design for manufacturing and the future functionality.

This work extends the development environment by functions for a design for assembly, which is important for hybrid MEMS. Two essential aspects are considered for an assembly-compatible design. On the one hand, the engineer is supported in the choice of suitable gripping and joining technology. CAD features for the knowledge based engineering are used for this. On the other hand, the influence of manufacturing tolerances and positioning accuracy on the assembly is to be considered. To this end, the possibility to simulate assembly processes with tolerances was additionally integrated into the workflow of the development environment. Furthermore, it turned out that the commercial MEMS modelers used in the development environment have serious deficits. To compensate these deficits, CAD features for the MEMS modeling are presented. They are more robust in model generation and more flexible in the implementation of arbitrary fabrication processes.

The combination of the already implemented modules was also improved. Now it is possible to automatically prepare the fine voxel models of the etching simulator SUZANA for stiffness analysis with finite elements. The implementation is exemplarily carried out based on the CAD system NX. In principle, the CAD features are designed for arbitrary CAD systems. The necessary software related aspects were described. Finally, the functionality of the CAD features was demonstrated with different examples. A guidance design for linear actuators is used to present the support of the design for assembly. The CAD features for MEMS modeling are used to design a pressure sensor with piezoresistive principle. An example of an acceleration sensor with capacitive principle demonstrates the application of FE simulations on the basis of etching simulation results.