Eagle Autoroute Problem

Discussion in 'General Electronics Chat' started by pilko, Aug 4, 2013.

  1. pilko

    Thread Starter Senior Member

    Dec 8, 2008
    Hi everyone,
    When I autoroute in Eagle, the traces extend into the center of pads and vias. Copper is therefore filling the drill hole locations. I have to manually shorten the traces to the perimeters of the pads and vias.
    Can anyone please explain why it does this and what I can do to prevent it.
  2. MrChips


    Oct 2, 2009
    Why do you want to shorten the traces?
    It should make no difference to the PCB manufacturing process.
  3. pilko

    Thread Starter Senior Member

    Dec 8, 2008
    When I print the board, the trace is printed in the drill hole and the hole will not be etched. The drill will be difficult to position because of copper in the drill location.
  4. JohnInTX


    Jun 26, 2012
    I've always used the Gerber outputs for Eagle but know what you are trying to do, use the drill hole as a center locator for manually drilling the board.

    Poking around on the CAM Processor menu finds the Fill pads box which can be unchecked if your output device (EPS etc.) supports it. The description implies that the holes will be visible on the plot. You may have to add Drills and Holes layers to the layer tabs (Component side, Solder side etc.).

    That said, I didn't have a test file to see if it works but let us know what you eventually come up with.

    Good luck!
  5. DerStrom8

    Well-Known Member

    Feb 20, 2011
    The traces are supposed to go to the center.

    However, you should never use autorouters, except on the rare occasion that you've had to mix grid sizes and the traces do not quite reach the pads properly. But 99.99% of the time, you should NEVER EVER EVER use autorouters!

    Dave Jones, form the EEVblog, has a good explanation of why:


    You should definitely learn to route on your own, by hand.

    Anyway, the traces are placed where they should be. You need to drill through the copper. Make sure you have the right bits though. If you don't, they will slip easily and mess up your board.

  6. joeyd999

    AAC Fanatic!

    Jun 6, 2011
    Agreed! And I've done a ton of layouts in my life.

    Years ago, when there was a drafter who did the layouts for you (the engineers were not allow to touch the *very expensive* workstation -- I guess they were afraid we might take it apart to see what was inside), I'd sit with the drafter and tell him where to place the routes. As the board grew more dense, he'd invariable tell my that what I was trying to do was geometrically impossible. I make him rip out nets and move things around, then re-route over and over again. Eventually, things always worked. I drove him nuts, but he was getting paid regardless.

    An autorouter is just like that drafter, but it doesn't take instruction as well.
    DerStrom8 likes this.
  7. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    I route the important stuff by hand, optimising layout, and let the autorouter finish up the other less critical traces. Then I will often rip up some of it's work, and optimise those.

    The overall result is very close to as good as a complete manual layout, but was faster and less work. ;)
  8. pilko

    Thread Starter Senior Member

    Dec 8, 2008
    Thanks for the replies everyone. I note the comments on auto versus manual routing, but I would still like to solve the autoroute drill hole filling problem.

    @ JohnInTX I tried your suggestions without success (could be my lack of understanding)

    I am going to post the question to the Eagle forum. --- once again thanks everyone.