A proven operational CAD system for P.W.B. design-based on a mini-computer and featuring fully automatic placement and routing.

TLDR: The techniques used within the company are outlined and some of the procedural advancements are indicated, and the reasons for their introduction are indicated.

Abstract: The introduction of electronic processor controlled switching systems has led to a re-appraisal of the methods of designing printed wiring boards to cope with the sheer numbers of designs required and their increasing complexity. The Company's policy is normally to realise the equipment on double sided printed wiring boards (pwb) containing a maximum of 80 integrated circuits per board plus discrete components. (Figs. 1 and 2)PWB requirements are frequently changing as new techniques and processes are introduced and therefore methods of improving pwb layout and artwork preparation are continually under investigation.This paper outlines the techniques used within the company and indicates some of the procedural advancements, and the reasons for their introduction.