Bob what is the circuit, I’m really surprised freerouter could not do a two layer board. I have done 80486 boards where literally finding spaces for the chips became the issue yet freerouter resolved in 2-3 days. The initial placement of chips is most critical. Try and avoid as much as possible the net wires crossing over each other. Another trick is to let it run say 2 or three days. Save the file, and in KiCAD see what is not connected. Start again, but first link up by hand the previously unconnected wires. Most companies these days will do multilayer boards including PCBCart. However > 2 layers are more than 2X more expensive. Have not done > 2 layers John From: n8vem...@googlegroups.com [mailto:n8vem...@googlegroups.com] On Behalf Of Bob Bell I am working on a board design (details to appear later - it's getting close) and I am concerned about component density and the ability to route the board. A previous version of the board pretty much maxed out component count and took several weeks (albeit rare spare time) to hand route (the autorouter I was using at the time just utterly gave up.) This new design, even with all the random logic and some of the higher-level logic crammed into 12 GALs, exceeds the pin count, my measure of board density, of the previous version by nearly 30%. So, it is looking quite likely that I'll need to go to at least a 4-layer board to be sure it can be routed with the chips as close to each other as I believe they will need to be. -- |