Eagle Cad question: edge connector problem...

I have created an edge connector package (I used a modified copy of an existing edge connector library) which has a problem: the connection point seems to be in the middle of the connector pads. Auto will connect between the pads and will place vias between the pads. I need the connection point to be on the inner-most edge of the edge connector finger pads, not the middle. Any way to do this?
I can move the vias and wires after Auto routes them, but it's a lot of work and isn't as clean. I have tried adding pads and holes at the back of the finger pads, but auto seems to ignore them and persists on keeping the starting point in the middle of the pad.
Hope someone can help, thanks...

Hi,

your description is somehow confusing to me.

I suggest you post a screenshot of all three: symbol, package and device.

Regards

Boncuk

He's saying that the autorouting is sending the trace out to the side of the pad rather than the way he wants it, out the end furthest from the edge. Like the routing between pins in P1 and P2 in this post:
https://www.electro-tech-online.com/threads/opinions-on-this-pcb-layout.103666/

How you fix that without manual routing, I do not know.

Hi Mark,

even using the autorouter (which routes the shortest connection between two pads) the traces can be split after routing for a clean layout.

I used NewIO (running under AMIGA-DOS) some thirty years ago. That autorouter optimized traces other than Eagle does to hit pads straight in whenever possible.

Moreover the Eagle autorouter ignores design rules by connecting traces at an angle of approximately 30degrees when using a grid size smaller than 0.635mm and sometimes even zigzags around a via, which could be avoided by moving the via.

Boncuk

P.S. My opinion about the PCB you posted to comment: It's crap.

computerexpert said:

I can move the vias and wires after Auto routes them, but it's a lot of work and isn't as clean. I have tried adding pads and holes at the back of the finger pads, but auto seems to ignore them and persists on keeping the starting point in the middle of the pad.
Hope someone can help, thanks...

Click to expand...

I realized from your explanation that you are just trying to move the traces to the correct position afterward. For a clean routing, you should be ripping up the traces that aren't routed the way you like then replacing them. You don't need to rip up the whole trace, just far enough back from the pad to do a proper route. Route starting from the pad in order to have the trace centered on the pads origin.

Boncuk said:

P.S. My opinion about the PCB you posted to comment: It's crap.

Click to expand...

I didn't post it for comments, or at all. I linked to it as an example of what the OP was talking about

DirtyLude said:

I didn't post it for comments, or at all. I linked to it as an example of what the OP was talking about

Click to expand...

The OP did so.

Boncuk said:

The OP did so.

Click to expand...

Sorry, I thought you were saying it's mine. You already posted in that thread, and yes, it's fairly typical of new people that just place everything and hit autoroute.

I have attached an example (two sided board with edge connector). Note the traces and vias between the edge connector fingers. Even if I route manually, it still wants to start the trace at the center of the pad. I have tried playing with the Net Classes Design Rules with out much success.

Hi computerexpert,

when routing a board containing pads (most probably metric pad spacing) you should use a finer grid, e.g. 0.0125inches (presently used 0.05inches).

If that won't suffice reduce grid size to 0.00625inches. Don't use a pure metric grid since you will run into problems with the inch-based IC.

Traces will be straight out of the pad and you can move the vias outside the connector.

It will require quite some time to route satisfactorily, but as already mentioned by Mark you might rip up single traces and reroute manually.

BTW, the autorouter won't do a thing at grid sizes smaller than 1/160inch.

I suggest to start routing from two pads and end the trace temporarily somewhere on the board. Then pick either end of the trace and continue routing until traces meet (on grid).

Regards

Boncuk