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Why this wire wants to go around the pad and connect from behind?

frnhr

I'm wiring a simple PCB by hand. I'm a complete noob, and puzzled by why this wire wants to connect at the back of this pad. The wire and the pads are connected to the same net (there is an airwire between the pad and the already-routed part of the wire).

 

If I start from the pad, then I can create a straight wire.

 

Am I _supposed_ to route this from "behind"? What's going on here?

 

The part is "LED (Version 10)", footprint "SMARTLED-TTW (Version 1)", library "led (Version 5)". But I have seen the same behaviour with an SMD resistor.

 

Screenshot... the intended route path might be a bit difficult to see here, but if you look closely you can see it wants to go over and around the pad and connect to if from the right side.

 

image

  • I can see a small bulge just below the pad. have you already got a small stub of a trace connected there that's hard to see? Maybe that takes priority over direct to the pad.

  • in reply to Fred27

    Well spotted! A leftover from before. But it has no effect on the behaviour, I saw it the first time I was routing a wire to the component. There was definitely no old wires then. (Plus I deleted the bulge and tried again just now, to be really sure.)

  • in reply to frnhr

    Just wondering why you are asking an Eagle PCB question here?  I'm not trying to be rude.  If Eagle has a forum you might get a better answer if the issue is specific to there PCB design.

     

    I don't know Eagle but, perhaps the pad structure is such that the target connection is only at the back and the front of the pad does not actually have a net associated with it.  This sort of thing could happen in CS if you put a footprint or a pad on a PCB that does not have a net list connection back to the schematic.  The routing will try to avoid connecting to copper that is not part of its expected netlist.