In this paper, Printed Circuit Board Assembly Advisor (PCAAD), an object-oriented knowledge-based system is described. The system aims to aid the designer by suggesting design modifications that will lead to a better design for assembly of the Printed Circuit Boards. To account for the new trends in the printed circuit board production, hybrid technology, i.e. combination of both the through-hole mounted technology and surface mounted technology, is taken into consideration in developing the knowledge base. The assembly constraints as well as various limitations of different techniques and processes are considered to formulate the rules and guidelines. Moreover, a hierarchical rule structure has been employed in creating the knowledge base. Smalltalk-80, the object-oriented language and Surface Percept Description Language (SPDL) are used for the creation of knowledge base.
The system provides a high-level user interface and reasoning capability to solve complex problems. It is capable of ranking different designs and suggesting design modifications to the designer during the design stage to eliminate assembly problems in the latter phase of board production.