Free Trials

Download a free trial to find out which Altium software best suits your needs

How to Buy

Contact your local sales office to get started on improving your design environment


Download the latest in PCB design and EDA software

  • Altium Designer

    Complete Environment for Schematic + Layout

  • CircuitStudio

    Entry Level, Professional PCB Design Tool

  • CircuitMaker

    Community Based PCB Design Tool


    Agile PCB Design For Teams

  • Altium 365

    Connecting PCB Design to the Manufacturing Floor

  • Altium Concord Pro

    Complete Solution for Library Management

  • Octopart

    Extensive, Easy-to-Use Component Database

  • PDN Analyzer

    Natural and Effortless Power Distribution Network Analysis

  • See All Extensions

    World-Renowned Technology for Embedded Systems Development

  • Live Courses

    Learn best practices with instructional training available worldwide

  • On-Demand Courses

    Gain comprehensive knowledge without leaving your home or office

  • Altium 365 Viewer

    View & Share electronic designs in your browser

  • Altium Designer 20

    The most powerful, modern and easy-to-use PCB design tool for professional use


    Annual PCB Design Summit

    • Forum

      Where Altium users and enthusiasts can interact with each other

    • Blog

      Our blog about things that interest us and hopefully you too

    • Ideas

      Submit ideas and vote for new features you want in Altium tools

    • Bug Crunch

      Help make the software better by submitting bugs and voting on what's important

    • Wall

      A stream of events on AltiumLive you follow by participating in or subscribing to

    • Beta Program

      Information about participating in our Beta program and getting early access to Altium tools

    All Resources

    Explore the latest content from blog posts to social media and technical white papers gathered together for your convenience


    Take a look at what download options are available to best suit your needs

    How to Buy

    Contact your local sales office to get started improving your design environment

    • Documentation

      The documentation area is where you can find extensive, versioned information about our software online, for free.

    • Training & Events

      View the schedule and register for training events all around the world and online

    • Design Content

      Browse our vast library of free design content including components, templates and reference designs

    • Webinars

      Attend a live webinar online or get instant access to our on demand series of webinars

    • Support

      Get your questions answered with our variety of direct support and self-service options

    • Technical Papers

      Stay up to date with the latest technology and industry trends with our complete collection of technical white papers.

    • Video Library

      Quick and to-the-point video tutorials to get you started with Altium Designer

    The PCB Routing that Benefits the Most from Interactive PCB Auto Routing

    Altium Designer
    |  October 13, 2017

    Worker on roof

    Years ago I helped to re-roof a house, and the first task was to remove the old shingles. Pulling up shingles one at a time, I was very proud of my efforts until a professional roofer came over to me shaking his head. Using a scoop shovel like a snow plow, he removed a couple a hundred shingles in less time than it took me to pull up five by hand. I learned up on the roof that day to always look for better ways to get the job done.

    When routing a PCB design, we also want a more efficient way to get the job done. You as a are probably aware of how much time is takes to manually get the cleanest route possible.  You’re probably also aware of Auto routers, which will do the job faster, but often with undesirable routing results. Now, like how the shovel was a better way to remove shingles, we have a better way to route using an auto-interactive router.

    For those of you who aren't familiar with the term auto-interactive router, this is a relatively new routing technology. It is designed to give you trace routing that has the look and precision of manual routing but at approximately one connection per second. Auto-interactive routing is not a batch auto router and is not designed to route your entire board. Instead, it is interactive PCB auto routing where you have the control and the router does the work.

    While auto-interactive routing can generally speed up your process, there are areas of circuitry that benefit from it. Particularly, single or multiple nets that need to be connected in a specific order without changing layers. More specifically this can be, point-to-point routing, BGA breakout routing, and bus routing.

    Point-to-point trace routing

    As you know, PCBs have many point-to-point connections. These can be short nets that connect component pins in tight circuitry groups, via escape patterns from SMT pads or nets that run the length of the board. These are not difficult to manually route, but they take time. An auto router will route them very fast, but you may be left with undesirable routing on the rest of the board. You could restrict the auto routing to just the short connections, but that requires additional setup time before you can use the auto router.

    An auto-interactive router is incredibly fast when routing these same nets. You will simply select the nets that you want to route and then engage the router. Using the design rules that you have already established in the database, the auto-interactive router will use the shortest possible path to route the traces. It will also do this without the cumbersome setups that an auto router requires.

    Computer motherboard circuitry
    An auto-interactive router works well to connect short point-to-point connections

    BGA trace routing

    Before manually routing traces out of a BGA, you’ll need to take the time to figure out the best connection order of the nets. This ordering is important so that the can route the traces in the most efficient patterns possible to connect the BGAs. Efficient routing patterns not only leave open space on the board for additional routing but will reduce or eliminate the need for vias. Vias take up space that you may need for other routing, and they can introduce undesirable signal characteristics. Using an auto router for BGA routing may actually increase your via count as it typically does not choose the best connection order of the nets.

    This is where using an auto-interactive router can be handy. It can quickly order the BGA connections for you. It will evaluate your selected nets in order to evenly distribute the traces on the board layers that you have enabled for routing. The auto-interactive router will then route the traces to connect the BGAs together in clean and precise routing patterns without using vias. These clean routing patterns will give you the additional board space that you will need for trace tuning or other routing edits later on.

    Computer motherboard trace routing
    Bus routing is another strength of an auto-interactive router

    Bus trace routing

    Often times buses are manually routed to create a clean routing pattern. If the bus is not routed in a clean pattern, it could cause problems with the signal characteristics of the bus. The downside is that manually routing a clean bus pattern takes a lot of time. Buses can have a lot of nets in them, and some boards may have several different buses as well. For example, double data rate (DDR) circuitry is an example of multiple bus routing with high net counts.

    An auto-interactive router will route the nets of a bus for you, but it will do it under your control. First, you will select the nets of the bus that you want to route. Next you will draw a path on the board that you want the bus routing to follow. This path is a template that specifies the direction and width of the bus to the router. The auto-interactive router will then follow the path to route the traces all while obeying the design rules at the same time. The router does this work very quickly, and the results are a very clean bus routing pattern.

    Just as the shovel was a much better way to remove shingles, an auto-interactive router is a much better way to route your PCB design. Knowing the best ways to use this router will be the key to your success, and we’ve talked about three of those ways. Point-to-point, BGA, and buses are all areas of routing that an auto-interactive router can help you to do a better job.

    Routing is part of the PCB design process that Altium can help you to do a better job with. Altium Designer® is PCB design software with powerful resources, including auto-interactive routing with ActiveRoute®. Would you like to find out more about how will be able to help you to route your next PCB design? Talk to an expert at Altium.


    Check out Altium in action...

    Powerful PCB Design

    About Author

    About Author

    PCB Design Tools for Electronics Design and DFM. Information for EDA Leaders.

    most recent articles

    Back to Home