On 19 Jun 2008 at 13:39, Rick Collins wrote:

> I think I see where you are headed with this and I don't think it is a
> good idea.  You want to add vias to act as pads for the jumper
> resistors, right?  That may get you pads on the board, but you won't
> have an entry in the XYRS file for the jumper!  
> 
> I would suggest that you first try to lay out the board without
> jumpers and see how far you can get.  If you are not using fine pitch
> parts and can route signals between pins, you should be able to get a
> pretty high percentage of nets routed without jumpers.  Then adding
> jumpers to the schematic should only take one or two iterations.  If
> your board is crowded or your parts are fine pitch, this won't work so
> well. 
> 
> But I don't think using vias as pads is a good idea at all.  
> 
> If you really must use vias as pads, you can pick a unique drill size
> and then just remove all references to that drill size from the drill
> list.  This will be "manual" editing of the drill list, but it can be
> semi-automated using search features in any editor.  
> 
> Rick
> 
  I use testpoints for pads for jumpers.  On your schematic you can place a 
test point 
component and draw a line(not a wire) between.  Then on the PCB, the TP pads 
will appear 
since it is a component.  I then draw lines on the silkscreen layer showing the 
jumper 
connections.
  You could also make up a special schematic library component that has the 2 
pads.  Then 
make up a special pcb module with the pads and a line on the silkscreen layer 
showing the 
jumper location.  The disadvantage to this is you would have to know ahead of 
time the 
distance between the 2 pins(that's why I use singe test points - they can be 
moved at will 
when doing the layout.)

Dave - WB6DHW
<http://wb6dhw.com>

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