Development of a printed circuit board design for in-circuit test advisory system

Abstract

The complexity of Printed Circuit Boards (PCBs) has increased dramatically with the use of surface-mount technology. The manufacture of double-sided boards densely packed with very fine pitch devices is complex, as is the identification of faults on these boards. Traditional approaches to the test of assembled boards have relied on making physical contact with testpoints on the board surface. In-Circuit Test (ICT) allows the manufacturer to verify the operation and electrical connection of discrete devices soldered on the PCB, allowing faults to be located and rectified quickly. ICT usually requires the manufacture of a test fixture specific to the PCB. If testability guidelines are observed during PCB design, the fixture required will be less complex and more reliable. This paper describes results from research being conducted at the University of Salford aimed at improving and integrating the PCB and ICT fixture design and development processes. The research results are demonstrated in a working prototype DICTA (Design for In-Circuit Test Advisory) system. This is separate from the CAD system and can be invoked to analyse and provide feedback on the PCB layout stored within the CAD database and to generate information required for fixture design. This paper presents some of the main findings of the research to date and the implications for the development of systems to support Concurrent Engineering of Printed Circuit Boards.