Enhancing An Autorouter With A Hexagonal Grid

Despite the current leaps ahead in different types of computer-driven design, the reliability of PCB autorouters stays questionable; on the optimistic aspect, although, the shortage of large coaching information makes them believable for a decided programmer to implement. For anybody considering this endeavor, [James Bowman] recommends a barely uncommon alternative: use a hexagonal layout grid.

[James] constructed his personal autorouter in his CuFlow PCB layout program. It takes a reasonably easy strategy: it represents the board as a grid of cells, and makes use of Lee’s algorithm to seek out the shortest routes between related cells. The program initially used a sq. grid, however a hexagonal grid had a number of benefits: specifically, every cell has six equidistant neighbors, fairly than 4 (or eight, when you settle for diagonal neighbors at a distinct distance), which permits denser routing. Because a hexagon extra carefully approximates a circle than a sq., the identical minimum-distance guidelines permit smaller cells, permitting the autorouter to pack extra traces into the identical area.

While now we have beforehand seen a self-built autorouter, it’s way more frequent to interface with an external tool. If you begin to get into high-speed PCB routing, although, constructing an autorouter turns into a lot tougher.