Does anyone have any suggestions on creating footprint with thermal pad that requires topside via tenting on the top side?
I tried making shape symbols for solder mask/ paste mask, but due to the void in the shape it requires I am not able to create it.
I can place the shapes manually in package geo/ SM or PM, but I think lot of the data does not have it to display in the default setting for our filmsetting.
Please let me know if there is a way to make the shape symbols or not.
Thanks in advance.
Those FETs have a grounding slug that the manufacturer hopes you will SMT reflow solder.
Vias are suggested by the manufacturer if you want to use the pcb to conduct heat or connect the FET center pin to a different layer.
I actually wonder if you can relocate those vias outside of the slug soldering area, if you need to conduct electricity to another layer.
Slug pads with integral vias are usually found in microwave/RF devices to keep parasitic inductance to a minimum. I believe your design is more focused on DC current.
If the goal is to transfer heat... Not sure what benefit can be had from conducting heat to an internal layer directly under the slug with vias. You could add a solder-down heatsink resting on top of the SMT package to dissapate heat away, or maximize the copper area of the layer you are showing us to improve thermal conduction (Thermalloy?)
I know there is aluminum core construction. But, I don't know if the PCB is a reliable solution for removing heat.