A minicomputerized automatic layout system for two-layer printed wiring boards

摘要

The requirement for high density packaging is dominant in the design of electronic systems. In the assembly of such systems multi-layer printed wiring boards are often used to provide the necessary connections among functional modules, and as the wiring density for a board ascends, an automatic scheme to realize 100 percent wiring would be more essential to reduce cost and time incurred in laying out wire pattern. Thus, methods to improve the layout of printed wiring boards are still continually under investigation.

The present paper proposes an automatic layout system for two-layer printed wiring boards, which operates on a PDP 11/40 computer with 24K 16-bit words of core memory and with 1.2M words of disk storage, coupled with a TEKTRONIX 4014 display terminal in conjunction with a 4953 graphics tablet. This system has been at work, and more than 300 wiring boards of manufacturing use have been already processed automatically by this system, almost all with 100 percent routing realized. A part of such implemented results are also shown.