Sketch Routing: A New Paradigm

By vernwnek

In my last post I mentioned my recent conversation about autorouting with several PCB designers at the IPC Council meeting in Irvine, California. Take a look at the previous post, Auto Assisted Routing: “I ain’t got time for that!” You will see that there are mixed feelings about autorouting, and many think we needed something better.

The IPC meeting that I’m referring to happened to be all about routing technology that is currently available and there was more than one vendor in attendance to present their wares. I got to go first, and I proposed a question.

I showed them a design with two FPGAs and 120 twisted netlines connected between them and asked, “How fast could you route these netlines?” The answers around the room ranged from 30 minutes to an hour. I selected the netlines, started the Sketch Router with a click, and said, “What if you could route them in one minute?” As the routes completed, I knew I had their undivided attention.

Before Routing:

FPGA Challenge: Before Routing
After Routing:
FPGA Challenge: After Routing

As a PCB designer, I consider myself an artist as I create beautiful artwork for the products of the future. For the younger PCB designers in the room, I explained that what we output to manufacturing in the past was actually called “artwork.”

As the show continued, I used my cursor like a painter uses a brush to select and route netlines and groups of netlines. First, I showed a DDR3 circuit that I routed in less than four minutes. Then, a PCIe circuit with differential pairs that I easily routed in about two minutes – including the matched length tuning. I moved around the design with the ease of routing with an autorouter while maintaining complete user control. The routing method utilized my intent and direction, but the algorithms gave me the speed and quality of a manually routed design. If I made a mistake, a quick undo allowed me to reroute entire groups of netlines in seconds. Take a look at the links below to see some of the circuitry I routed.


I wowed the room to a point of silence, and then I posed a second question:

“For those of you who said you do not use autorouting, would you use this autoroute method on your designs?” The unanimous response was “YES!”


So, you provide designers with an autorouting method that is easy to use, and uses the designer intent, they will use it.


Sketch Router is a new paradigm in auto assisted routing. I believe it to be the next big step for designers to provide fast, high quality designs – all with the look and feel of a completely hand-routed design.


One more thing about the IPC meeting…


Many thanks to those who came to me after the meeting and made statements like these: “The other guys should have been embarrassed to show their tools; they did not route a single trace, while you routed a huge portion of your design in under 20 minutes!”


It’s great to hear my colleagues say that they truly believe this is a game changer in the PCB Design industry. I agree! What do you think?


Sketch Routing Demo

Routing and Tuning DDR3 in Under Three Minutes


2 thoughts about “Sketch Routing: A New Paradigm
  • Wow, I was one of the skeptics early on concerning autorouting. I remember doing the critical routes manually then locking them, prior to autorouting the rest. Well the results always entailed a lot of cleanup, which even with via constraints, the autorouter would stick ’em ever which way. We did autotest on most of our boards and if a via was under a component, we could not use it as a test point. Eventually the bossed nixed the autorouter as being too time consuming and we manually routed every board. Question: How well does sketch routing do on round multilayer boards?

    • Juan,
      Sketch Router does very good with all types of boards. Round boards, if routed using typical 45 degree routing will be of no issue to the Sketch Router. If you route your round boards using Any Angle routing, then that will need to be completed interactively. The good news there is that in the new Xpedition VX release, there have been many improvements in Any Angle routing and editing of those routes through dynamic move.


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This article first appeared on the Siemens Digital Industries Software blog at