How to join tab to middle pin in a sot-223 package?

Layout
1

Hello,
I want to join, with copper, the tab of a sot-223 to its middle pin with a triangle like shape.

This is what I have:

618Ă—508 12.1 KB

And this is what I want (made with the gimp):

618Ă—508 18.1 KB

Do I need to edit the footprint or can I do it with pcbnew?

Thank you.

2

You can create a zone for that. Assign it to that net. It is OK if you still left there the track and the zone. Mind that the zone must “surround” the pad in order to be consider included in the net (that grey lines you have in picture)

1 Like
4

Creating one simple zone is not enough. As I see on the picture He need two zones: one for copper and another one for solder mask opening.

@JTechno, could you explain in more details why do You need this kind of connection?

6

As Andy_P suggests it is to improve thermal performance, this board doesn’t really need it because the power will be very low but I want to learn how to do it.

8

I think you are not on the right way if you want to improve thermal performance. Also open the solder mask, that will lead to undesired solder issues. The best way to go is to put more copper around with dissipation vias.

9

As this board don’t need thermal relief I was just experimenting, so I copied the idea from a HDD PCB which had a similar shape.

Now I know how to do it, I’ve used the “add filled zones” tool with “THT thermal” as pad connection and following Andy_P advice I’ve added as much copper as was possible.

Thank you all for your replies.