I have been designing printed circuit boards for a long time. Like most experienced PCB designers, I have my reservations about autorouters. Autorouters have a reputation for being difficult to set up and run, taking a long time to work, and giving questionable results. Often you would put your board into the router in the evening only to find the next morning that the results were not worth saving. I knew designers who would spend hours and hours “cleaning up” the routing that the autorouter had created. Often their cleanup wasn’t done to correct circuitry problems, they just couldn’t stand how it looked. Traces that would circle around the edge of the board, instead of going down a layer for the easy connection, were just one of the problems that those early routers would produce.
As a result, it is not unusual for PCB designers to avoid using automation and to stick with manual hand-routing instead. However, there is a whole new world of opportunity out there with today’s auto-interactive routing technology that you may not even be aware of. Let’s look at some of the reasons why designers opt for hand routing and then balance them with some of the benefits that today’s auto-interactive routing technology can give you.
That’s the way I’ve always done it
Let’s face it, we are all creatures of habit to a certain degree. I myself have often pushed back on using newer board design tool technologies because I had MY way of doing it and was resistant to change. That attitude, though, has only made me late to the PCB design party. The following examples are instances where designers often prefer to manually route their board.
Short connecting traces: I usually route short connecting traces from pin to pin by hand. Let’s face it, hand routing is cathartic. You can turn your brain off and just click-stroke-click-stroke-click-stroke all afternoon. I’ll admit it, there have been several times where I’ve spent a lot of time hand-routing in these short little connections so that I can later say to anyone who would ask that I have been busy working. Yes, it was busy work but it was gratifying to know for certain each connection was 100% accurate.
Complex circuits: Then there are the more complex areas of the board to route, which can be very fulfilling to route. Visualizing the routing in your head as you go, and making it all happen on the screen is not only fulfilling, it’s a lot of fun.
But all of this hand routing takes time, and that time could be spent on other aspects of your design or to help you get ahead. Here’s how the benefits of auto-interactive routing can help you to save time in your design.
Auto-interactive routing - a great change from the same old way
Auto-interactive routing, all the benefits without compromising the fun
One of the big perks of auto-interactive routing is that it will route traces using the design rules that you currently have set up. This saves you time, especially compared to previous experiences when “prepare your design for the autorouter” was as tedious as it was futile. With an auto-interactive router you tell it where to go, along the guide path you would take. It will route in the same manner that you would have.
With those short point-to-point connections, you can select the nets and engage the auto-interactive router. The auto-interactive router will give you manual routing results without you spending the time to actually manually route the traces.
For more complex routing you have the option to select the nets and then draw in a path that you want the routes to take. The auto-interactive router will use the layers that you’ve enabled to route the nets from pin to pin. You will still be directing the routing, but the auto-interactive router will be doing the heavy lifting of putting all the traces in for you.
Put the power of an auto-interactive router to work for you
Putting auto-interactive routers to work for you
Auto-interactive routers are not the solution for every situation. You will still want to exert more manual control over your critical routing, and sometimes you will want to override the decisions that the auto-interactive routing provides. You are still the designer and it ultimately falls on you to make sure that the design is correct.
Auto-interactive routing, however, can save you a lot of time and effort in manually routing a lot of your traces. If you’ve been avoiding auto-interactive routers because you don’t trust the technology or you don’t want to give up that portion of the job, break the habit and give them a try. You probably will end up finding that they are a design aid that you really can’t live without.
Would you like to find out more about auto-interactive routing? Talk to an expert at Altium.
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PCB Design Tools for Electronics Design and DFM. Information for EDA Leaders.More Content by Altium Designer