Auto Assisted Routing: “I ain’t got time for that!”

Recently at the IPC Council Meeting in Orange County, California, two of the top PCB design EDA vendors presented some of their current and upcoming technology for routing automation. The day was geared towards PCB designers and the methods they use for routing their designs.

The day started off with the typical questions that we spoke of in my first blog in this series, The Myth of the Pretty Design, and as usual, the responses about auto routing were the same as always. But I wanted to get to the bottom of why designers prefer not to use auto routers.

One designer I spoke with struck me with a quote that made me laugh. When I asked about auto routing, he just said, “I ain’t got time for that!” We both laughed, and he knew I had seen the famous YouTube video (if you aren’t sure what I’m referring to, search the quote).

As we spoke more about time required to auto route a design, the problem became more evident as to why most designers do not use them. He told me there is no one-button solution; auto routers must be setup properly to get a decent result. Learning which passes to choose and their parameters to choose can be very time consuming. Then once the routing is done, it can be hours, and sometimes days, to cleanup what the router completed. He stated that by the time he has cleaned up all of the extra vias and loops, he might has well have just routed it manually.

I asked, “Is there a situation in which you would choose to use an auto router?” He answered, “Yes, but typically only for a what-if scenario – I need a quick check to see if a board can be completed.” He did speak of other designs, like something purely digital.

We agreed that there are those times when an auto router is needed. He then said what we really need is a router that provides assistance during manual or interactive routing. This auto-assistance would guide the designer and allow for intuitive and quick routing with very high quality.

I then got a huge grin on my face and asked him to take his seat as the show was about to start.

Take a look at these video links to see some auto assisted routing technology. In the next post in this series we will talk about an entirely new paradigm in PCB routing technology.

Video 1: High-speed routing: High-speed PCB routing for tuning high-speed connections

Video 2: Real Trace Plow: Auto-active PCB trace routing mode