I have a component that needs to dissipate some heat.For this, the manufacturer recommends inserting lanes, and connecting the lanes to the GND plan.
The vias (made in the footprint) are "GND", the polygon biggest is also called GND (made in board), the small poligon are GND to but are in footprint.
However, it remains with thermal connections.
How can I connect the PADs continuously with the polygon and the GND plane without the "thermal width"?
Hi @Kristey ,
I hope you're doing well. Click on one of the polygon edges and in the inspector you'll see box named thermals is checked . Go ahead and uncheck it. The will allow the polygon to do a solid fill.
Looking at the image there are a couple of things that give me pause for concern. Normally the thermal vias only cover the thermal pad, but in this design they go well past it. The other thing that concerns me is why didn't that polygon outline fill.
If you could provide more details, I might be able to provide better suggestions.
Let me know if there's anything else I can do for you.
Best Regards,
Hi Jorge,
I believe that I also had this issue recently. I needed to edit the footprint of the device so I could manually place GND vias on the exposed thermal pad. I believe the issue may lie in the fact that in the device's footprint, the "vias" were really just PTH pads. Does Fusion 360 treat those differently when a ground pour exists where a PTH pad is?
In the old footprint that caused me the same issues mentioned above, it looked like this:
Then, I just removed them so I could place GND vias manually in the schematic:
Hi @wleismer ,
I hope you're doing well. There's no ideal way to do this, you'll usually get some form of error. With that said here's what I typically recommend.
In the library you add through hole pads to form the thermal vias, but, the key is here is that you use a polygon instead of and SMD pad to enclose them. This is the arbitrary pad shap functionality. As long as all the thermal pads connect to the same pin the polygon will be see as an extension of the those through hole pads. Keep in mind that with this procedure you will need to add the tstop and tcream opening manually.
The upside is that it will generate few if any DRC warnings and the thermal vias are part of the component so you never have to draw them again.
Let me know if you continue to run into problems.
Best Regards,
Hi @jorge_garcia
I tried your suggestion but it didn't work.
My footprint:
(this is a polygon)
Device in use:
Hi @Kristey ,
Thank you for including the pictures. You may have added the polygon, but you still left the large SMD in the middle of the chip. That large SMD needs to be replaced by the polygon not kept in addition to it. Just keep in mind that when you only have the poly enclosing pads you have to add the stop mask and cream mask manually.
Let me know if there's anything else I can do for you.
Best Regards,
