Creating a capacitive sensor

I'm trying to create a capacitive sensor that consists of 3 parts, an inner circle or sensor, an outer circle or shield and a ground plane. The traces should be made on the opposite side of the board to the pads.

I was hoping to create that as a library component so I can simply drop a bunch of these on the PCB. There don't seem to be so many design tools in the library for making pad designs as for making boards.

I've got the answer to how to create the concentric circles from here PatternAgents: Touch Widgets Library for Eagle

The sensors are neither through hole connections or SMD pads so how can I make it so that there's something for the schematic to connect to?

Is it possible to include a via in a package?

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kikoun over 11 years ago in reply to Workshopshed +1

Hi, You simply, in your library, draw each pad with the polygon tool, in the copper layer. Then you put a smd pad ( or TH pad ) inside each polygon. The trick is to draw a circle (or a disk) with the polygon…

0 Workshopshed over 11 years ago

This is the kind of thing I'm aiming for with 2 connections and a ground plane
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0 kikoun over 11 years ago in reply to Workshopshed

Hi,
You simply, in your library, draw each pad with the polygon tool, in the copper layer. Then you put a smd pad ( or TH pad ) inside each polygon.
The trick is to draw a circle (or a disk) with the polygon tool. But It's possible. It's easier for the center pad. For the external pad, you draw an non complete circle (like an arc) at first, then you reduce the distance of the 2 end of the arc until they overlap to complete the circle.... look at the example :

Guillaume.
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