Electronic – Thermal vias in Eagle (CAD)


I'm making a part in Eagle (4.15) for a SOIC-8 package. There is a thermal pad in the center and I'm trying to add vias stitching the top and bottom pads together. In the Eagle package editor there are no vias, I can add pads or holes. Is there a standard way to do this? I've found some related questions, and this, but no answers that help me.

I'm using an old version of eagle (4.15)

Best Answer

Use pads.

You can use an array of pads to create these thermal vias. The difference between pads and vias are that pads always go all the way through, vias can be blind or buried. For thermal vias, you want to go all the way through, so use pads.

If you use holes there will not be an electrical connection through the board, thus minimal thermal conduction. So it's rather pointless and will likely only cause DRC errors related to placing metal (for the thermal pad) too near a drill hole.

Here's an example from my library using pads for thermal vias.

thermal vias

Just connect each of the pads to the same pin as the ground pad. This makes them of the same net before being placed in the layout editor, thus avoiding the pad-to-pad or similar possible DRC errors.

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