A KNOWLEDGE-BASED OBJECT-ORIENTED DFM ADVISER FOR SURFACE-MOUNT PCB ASSEMBLY

The volume and complexity of printed circuit boards (PCBs) that use su rface mount technology has increased tremendously over the past decade . The intricacy of the design and manufacturing functions associated w ith this domain is continuously increasing. Several researchers have d ocumented the significance of the design functions on product life cyc le costs. lit the surface mount PCB assembly area, the integration of the design and manufacturing activity is hampered by the lack of suffi cient, in-depth manufacturing knowledge among the PCB designers. Also, the heuristic nature of manufacturing knowledge coupled with the freq uent advances in the state-of-the-art has resulted in the lack of wide spread in-depth process knowledge. This research focused on the design and development of a knowledge-based methodology which can be used to assist the design engineer in the surface mount PCB assembly domain. The rules relate primarily to the solderability, cleanability and refl ow aspects of the design. An object oriented programming (OOP) methodo logy is used. The OOP framework allows for structured and modular deve lopment and implementation of the knowledge-based design advisor. It a llows for the easy maintenance and update of the software along with t he integration of knowledge bases and databases. The system has been p artitioned into three major components - the user interface, the updat e mechanism along with the inference engine, and the database manageme nt utility. An important feature of this research has been the focus o n updateability of the design advisor with respect to data and knowled ge (rules). The logic or the rules within the system have been develop ed in an updateable format. The calculations required during the firin g of the rules are performed by dynamic linked libraries (dlls). The d esign advisor has been developed in the Windows operating system using the C++ language. The database manipulation functions are handled by Code Base 5.0 libraries.