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Topic: EAGLE went beyond PCB size limit?! (Read 2713 times) previous topic - next topic

liudr

I was revising a design and used EAGLE auto router. Strangely it has gone beyond my 100mmX80mm limit. I have light version.

Has anyone seen this happening?

Notice the top of the row of circular pads are at 80mm so anything beyond those aren't supposed to be routed but they did get routed. The Gerber files show these traces also.

liudr

I did some testing. They seem to disallow pads from going beyond around 82mm. Maybe there is no limit to routes. One other design I have also has traces beyond 80mm, around 84mm.

CrossRoads

If you have traces running outside the limits, I am guessing you don't have the board dimension drawn using 20dimension lines.
But you do seem to have ground polygon drawn.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

KirAsh4

Looking at that picture, there seems to be a dimension line drawn, but it's well outside of where your ground plane is.  And the traces are well within that dimension line.  I see four holes, two of them within your ground plane, and two of them outside, in the same area that you have the text written.  Eagle WILL route traces within dimension lines, and if they are drawn larger than what you expect the board to be, it will gladly put traces there.

liudr

I guess the size limit is more for pads than for traces. Yes, I drew the ground plains within 80mm limits but I do need some extra board space to put 2 mounting holes and some space for text on silk screen. Thanks.

KirAsh4


I guess the size limit is more for pads than for traces. Yes, I drew the ground plains within 80mm limits but I do need some extra board space to put 2 mounting holes and some space for text on silk screen. Thanks.


Eagle's funny that way.  While it allows you to draw the dimension layer as large as you want, it will not allow components to be placed outside of the limitations of whichever version you have.  So you can create a 80mm x 100mm board but draw the dimension as 100mm x 100mm.  When you tell Eagle to autoroute, it will gladly assume that you can use that additional 20mm, after all, you drew the dimension that way.  Also, the fab house will make your board based on that dimension layer, not based on where your components, traces, or ground layers are.  So again, they will gladly create a 100mm x 100mm board since that's what your dimension layer says ...

Your solution here is to first draw the dimension layer to match your circuit and how big you want it.  Once you're done routing, then redraw the dimension to the actual size of the final board.  Or, you can always hand route everything as opposed to using the autorouter.

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