Advanced CAD System for Electromagnetic MEMS Interactive Analysis

(a) (b) (c)
Figure 3-13: Three different MEMS geometries created using Geodesic. The switch (a)
was created using domain decomposition and process simulation. The micromirror (b)
and comb drive (c) were created using the geometric algorithm. Geometries
exaggerated in the z-direction for clarity.
3.4 A solid modeler independent implementation of the Composite CAD Process Definition
Specification
3.4.1 Introduction
The “Composite CAD Process Definition Specification 1.0” [11] is a proposed standard for
MEMS CAD vendors to specify the process flow used to create geometry (i.e. solid models) for
simulation. The file format is the product of over a year of interaction of numerous vendors
which resulted in a useful format with wide application for microsystems. The standard had
several key design objectives. First, it was designed to be an ASCII text file that was “human
readable.” In addition, the processing steps were to be the most common used in microsystems
(with particular focus on process operations which altered the physical geometry). Finally,
version 1.0 was designed to be a minimal standard so that maximum compliance across vendors
could be achieved.
This section describes the implementation details of the basic standard found in [11]. Here the
overview of a solid modeler independent implementation is given. The actual source code can
be found on the CD-ROM. The CCPDS format consists of eight commands, which are
organized functionally in Table 3-3:
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