Welcome, Guest
Username: Password: Secret Key Remember me

TOPIC: An Eagle Tip: Routing Traces to Pads

An Eagle Tip: Routing Traces to Pads 5 years 2 months ago #16764

  • Jon Chandler
  • Jon Chandler's Avatar
  • Offline
  • Moderator
  • Posts: 365
  • Thanks received: 352

Figure 1

It's desirable that connections to pads on a circuit board are correctly aligned to the center of the pad.  A few tips follow to aid in doing this.

Difficulties arise when pads are not on the selected grid in Eagle.  This can happen when mixing parts with imperial and metric units or when it's required to position a component to align with a panel or another board.

The illustration to the right shows the ideal case for a DIP package.  The pad pitch is 0.1" and the grid spacing is 0.05" as shown by the faint gray lines.  The traces intersect with the center of the pads.

The figure below shows what happens when pads aren't on the grid.  In this case, there's a DIP package with 0.1" pitch pads and a header with 2mm pitch.  The grid is set to 1mm and the header is aligned to the grid.  The connections to the header align with the center of the pads.

The connections to the DIP package don't align well.  Every other connection is so far off, the trace connects to the edge of the pad.  This can result in clearance problems, particularly when traces are run between pads, and a weak point where the trace and pad intersect.


An Eagle Tip: Routing Traces to Pads 5 years 2 months ago #16789

  • GM_Mike
  • GM_Mike's Avatar
  • Offline
  • Fresh Boarder
  • Posts: 19
  • Thanks received: 4
I just want to say that there is another way to accomplish this effect without having to worry about the grid size or where you are starting from. I usually just left click to start the trace, then select (right click is quick, don't even notice I do it often times) either bend style 0 or 4 and then route from there. When I get one click from destination, cycle to around to get it to snap to destination and done. The grid thing would help also when you are tying to wrangle the auto router into being not retarded, but I have only had luck getting to 1/2 retarded with him :P
Time to create page: 0.252 seconds