Determining trace/via/wire current capability

[Demon]

I found these web pages to better design my PCBs.

Traces:

https://www.mclpcb.com/blog/pcb-trac...current-table/


Vias:

https://www.worthingtonassembly.com/...hru-hole-sizes


Wires:

https://www.omnicalculator.com/physics/wire-size


EDIT:

Here's a calculator for traces/current:

https://circuitcalculator.com/wordpress/?p=25/

[Ioannis]

Valuable source of info.

Thanks for sharing,
Ioannis

[Demon]

If you want to increase trace/via capacity without increasing their size (maybe it complicates the rest of your circuit), just make more.




In my case, the 7805 voltage regulator takes the brunt of all components downstream, so that's where I increased their number.

[pedja089]

Put vias under component. Make bottom copeer pad large, and you have much better heatsink capabilites.
Make via also untinted ut botom, so you can fill it with solder. For my taste your trace to via are too small(I know it is only signal, but...).

[Ioannis]

I understand that you use Eagle.

How can you prevent solder mask at the area of the VIAS under the smd component?

Ioannis

[pedja089]

Yes it is eagle...

[Demon]

Put vias under component.

How is this?

[Demon]

I went one further using vias after adding cooling; grounding the VSS pin on the voltage regulator with 3 large vias.

This way it doesn't mess up the smaller vias I have on signal traces and VSS pins on tiny SMD ICs.


CORRECTION:

These are labelled backwards. The 7805 uses the TO-263 package and the Hexfet uses D2Pak (in my project).

[Demon]

... For my taste your trace to via are too small(I know it is only signal, but...).

JLCPCB can support up to 0.15 vias. I'm using 0.3 hole/0.5 pad since I'm using 2 layer PCBs.

https://jlcpcb.com/capabilities/pcb-capabilities


I'm not finding any "ideal dimension" for signal traces on the web...? They seem unanimous to say "however small your PCB fabricator can handle".

I'm using:

- 0.2 traces default,
- 0.3 for USART/USB,
- 0.3 for VDD.

[Ioannis]

I'm not finding any "ideal dimension" for signal traces on the web...? They seem unanimous to say "however small your PCB fabricator can handle".

PCB design is a bit of art. So, rules do apply but you can bend them (within reason of course) using common sense.

Nice touch the cooled grounding. Never thought of that. Though I do not know how much will contribute in cooling if the main tab is big enough.

Ioannis