Global Sourcing Spotlight: How to Evaluate Supplier Capabilities Worldwide
The Knowledge Base: Cultivating Your Brand in the Age of Connection
SMT Perspectives and Prospects: Warren Buffett’s Perpetual Wisdom, Part 2
Why I Finally Embraced Autorouting
July 3, 2025 | Stephen V. Chavez, Siemens EDAEstimated reading time: 1 minute
Here is a common misconception held by those who don’t fully understand the PCB layout process or how to wield today’s high-level EDA tools: "All I need to do is push the autorouter button, let the computer route all the signal traces, and get the layout 100% routed. It’s a no-brainer. Anyone can do it. It should take less than a few hours.”
Well, sure, if you’re in a hurry to check the box indicating you’re finished with the layout. But your results will look like a plate of spaghetti and most likely not function correctly, if at all, while not passing SI/EMC testing. Good luck with that mindset and methodology.
As you can see, there’s a lot of confusion about autorouting. I will discuss routing and autorouting in general terms, my initial distrust of routers, and the “a-ha” moment that changed my mind. Then, for specific autorouting techniques, I will focus primarily on the Siemens router.
Routing vs. Autorouting
Let’s start by setting the baseline for “routing” regarding signal traces. Traditional routing is done by manually connecting (routing) all signal traces from point to point, mouse click by mouse click. Then, we manually make any trace constraint modifications/adjustments as necessary to meet the design requirements. Once 100% routing is achieved, a design rule check (DRC) is performed, and all flagged errors must be addressed—after the fact. This legacy methodology is very labor-intensive and time-consuming, to say the least.
The form of routing most utilized today is “manual interactive routing,” with only a few higher-end tools possessing automation-assisted interactive routing capabilities. This manual interactive routing is a combination of human effort, along with software tool utilization, and some limited automation. The key here is that the user is manually performing and controlling each and every mouse click of the routing process, but with the addition of tool automation assisting/restricting and guiding the user along the way, and according to the constraints that were implemented.
To read the entire article, which originally appeard in the June 2025 Design007 Magazine, click here.
Share on:
Testimonial
"In a year when every marketing dollar mattered, I chose to keep I-Connect007 in our 2025 plan. Their commitment to high-quality, insightful content aligns with Koh Young’s values and helps readers navigate a changing industry. "
Brent Fischthal - Koh YoungSuggested Items
Happy’s Tech Talk #42: Applying Density Equations to UHDI Design
08/19/2025 | Happy Holden -- Column: Happy’s Tech TalkWith the need for faster speeds, more parts on an assembly, and the trend to make things smaller for portability, the printed circuit design and layout process is both creative and challenging. The process involves “applying the density equation” while considering certain boundary conditions, such as electrical and thermal performance. Unfortunately, many designers don’t realize there is a mathematical process to laying out a printed circuit.
Beyond Design: Effective Floor Planning Strategies
08/20/2025 | Barry Olney -- Column: Beyond DesignComponent placement on a printed circuit board is more involved than simply fitting parts into available space. It plays a pivotal role in determining the board’s overall manufacturability, performance, reliability, and cost. Poor placement can compromise even the most meticulously designed PCB. Effective component placement alleviates mechanical stress, promotes efficient thermal management, and helps prevent excessive heat buildup.
Global PCB Connections: Understanding the General Fabrication Process—A Designer’s Hidden Advantage
08/14/2025 | Markus Voeltz -- Column: Global PCB ConnectionsDesigners don’t need to become fabricators, but understanding the basics of PCB fabrication can save you time, money, and frustration. The more you understand what’s happening on the shop floor, the better you’ll be able to prevent downstream issues. As you move into more advanced designs like HDI, flex circuits, stacked vias, and embedded components, this foundational knowledge becomes even more critical. Remember: the fabricator is your partner.
Beyond Design: Refining Design Constraints
07/17/2025 | Barry Olney -- Column: Beyond DesignBefore starting any project, it is crucial to develop a thorough plan that encompasses all essential requirements. This ensures that the final product not only aligns with the design concept but is also manufacturable, reliable, and meets performance expectations. High-speed PCB design requires us to not only push technological boundaries but also consider various factors related to higher frequencies, faster transition times, and increased bandwidths during the design process.
Target Condition: Are Autorouters Friend or Foe?
07/01/2025 | Kelly Dack -- Column: Target ConditionFor PCB designers, just hearing the word “autorouters” can trigger everything from eye rolls to heated debate. We all have stories—some painful, some comical—of boards gone sideways at the hands of an overzealous routing algorithm. But these tools aren’t going away, and frankly, they shouldn’t. Used wisely, they can save some project teams hours or even days. Used blindly, they can cost weeks. So, where do autorouting tools stand today, and is interactive routing the smarter path forward?