Manufacturing Process Flow Reasoning of Micro Device Based on Ontology

Based on feature modeling technology, a method of manufacturing process flow reasoning of micro device is presented to support the top-down design flow. The knowledge of micro device is hierarchically organized to construct the ontology-based knowledge database that is combined with the expert system by an interface. With the support of process databases, the manufacturing process flow is derived by process reasoning. Introduction Nowadays the micro device is more and more complex. However, the design flow of current design tools is still from the process designing to 3D model constructing. It is unintuitive to designers. As an advanced theory, the Top-down design method starts at the system level and makes designers pay less attention to the fabricating issues [1]. The more reasonable design flow can be characterized briefly as “function-to-shape-to-process”. Therefore, problem-solving in the sector of converting the design model to the manufacturing process flow is the guarantee of good manufacturability. To achieve this goal, some researches have been underway. For a function-oriented modeling process, feature model was presented [2]. Besides the above feature modeling, the “forward” and “inverse” design flow problems were also studied as key issues [3]. Another approach accomplished the mask creation by investigating the vertical topology of the model [4]. Especially in bulk micromachining, the process reasoning technology to support top-down design flow is still need to study further. An essential difficulty lies in the standardization of the processes. Some achievements have been registered like the standard processes about bonding and sacrificial layer technology [5]. Along with the standardization of processes, the expert system is applied to manufacturing flow reasoning. Ontology has a bright future for application in information sharing, system integration and software development based on knowledge, etc. Especially for the hierarchical description of the knowledge in micro device manufacturing, it has advantage. Based on feature modeling technology, this paper concentrates on manufacturing process flow reasoning of micro device with a hierarchically organized knowledge database by ontology. Currently, it is used in bulk micromachining. Feature Modeling Technology in Bulk Micromachining The design model of micro device is constructed with design features. First of all, the manufacturing features are obtained to confirm the necessary processes. On account of the characteristics of the top-down design flow, the information framework of micro device is three levels as shown in Fig. 1. The functional model is constructed with functional features at the first level. The mapping process of function/geometric features can be formalized by adopting the macro script language. The 3D design model is obtained at the second level. It is CSG-represented and made up of geometric features. Applied Mechanics and Materials Vols. 10-12 (2008) pp 248-252 online at http://www.scientific.net © (2008) Trans Tech Publications, Switzerland Online available since 2007/Dec/06 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of the publisher: Trans Tech Publications Ltd, Switzerland, www.ttp.net. (ID: 130.203.133.34-16/04/08,09:00:55) Cuboid Cylinder Extrude