Single-layer automatic router

We are developing a single-layer automatic router of printed circuit boards.We are focusing on a data structure and search strategy for solving a hard wiring problem.

Motivation

Single-layer printed circuit boards are used in mass-produced consumer electronics products such as TV, radio, video recorder and etc. They can be produced at a very low price using cheap board and low cost printing. PCB is composed of LSIs, ICs, registers, capacitors, etc, and wires connect those components without crossing lines. The main difference from multi-layer PCBs is the usage of jumpers. A jumper is used for the connection of terminals which cannot be connected each other. The wiring design of these boards are done by human experts, while the design of multi-layer boards are done by the auto-router of electrical CADs. The design could usually take two or three days, and electrical structures and/or chip layouts could hardly be changed afterwards.With functions getting more complex and wires getting denser, it becomes increasingly difficult to design manually. The proposed system enables electrical designers to try some prototype, and to design routing layout by himself.

Key features

• Any-angle wirings
  TRL has an any-angle routing technology, which is the key technology in design automation of PCB. The routing enables wiring spaces larger than limited routing widely used in commercial systems whose wiring design is composed of horizontal line, vertical line or 45degree lines.

• Even-spacing technology
  With the even-spacing technology, the router spreads inter-wire distance so as to improve electric characteristics and production yields of generated wiring patterns.
• Net generation technology
  With the net generation technology, the router generates a wiring pattern for LSI packages, simultaneously determining optimal pin assignments to bonding pads.
• High-density wirings
  An any-angle wiring can reduce the extra space toward diagonal directions. Furthermore, our router has the gridless wiring capability and can hold a wire width and clearance correctly.
• High performance any-angle router
  TRL has devised a topological grid structure for representing wiring spaces. We can achieve the search space reduction for finding a route of a wire. We also devised heuristic estimation programs for judging further wiring possibilities.

Wiring examples

Publications

• Path search algorithm
  • Toshiyuki Hama and Hiroaki Etoh, "Topological Routing Path Search Algorithm", ASP-DAC97,1997
  • Toshiyuki Hama and Hiroaki Etoh, "Topological Routing Path Search Algorithm", TR-172,1996

• Routing strategy and routability estimation
  • Hiroaki Etoh and Toshiyuki Hama, "Single-layer Global Router", TR-170,1996

• Wire formatting
  • Toshiyuki Hama and Hiroaki Etoh, "Curvilinear Detailed Routing Algorithm and its Extension to Wire-spreading and Wire-fattening", ASP-DAC98,1998