A PCB trace that carries considerable current (~5 Amps) needs to be wide, on the order of 4mm. I am concerned that this wide and thick (70mil) trace may cause problems during hand soldering, but can not figure out a way to make thermal relief for the pads in Kicad. It is easy for copper fills, but that would mean drawing by hand outline for each trace. Is there a less laborious way?

  • \$\begingroup\$ A half decent iron won't have any trouble with a trace like that. Simply observing good soldering technique using appropriate methods (clean tip, flux, good quality solder and a bit of experience) will suffice. \$\endgroup\$ – user98663 Oct 8 '16 at 15:18
  • \$\begingroup\$ Thank you for your input. I don't have much experience with PCB design. Do you think that soldering will not present problems even if I connect with duplicate traces on both sides of the board? \$\endgroup\$ – Mikhail Kagalenko Oct 8 '16 at 15:20
  • \$\begingroup\$ I think you need more practical soldering experience before getting involved with the more unusual aspects of PCB design. You can't beat experience. :) A good way to learn is to take apart old broken junk from ebay and attempt to desolder/reattach parts by hand. It doesn't matter if the parts work afterwards, but just learn how thermal mass can affect your iron's ability to get heat into a PCB. It's also great fun and you can harvest parts this way to re-stock your workbench. \$\endgroup\$ – user98663 Oct 8 '16 at 15:23
  • \$\begingroup\$ I have no time for that, that's why I am asking for help on stackexchange from those who do have the experience. \$\endgroup\$ – Mikhail Kagalenko Oct 8 '16 at 15:24
  • \$\begingroup\$ Okay, then see my first comment. \$\endgroup\$ – user98663 Oct 8 '16 at 15:25

There are two cases:

  • the current needs to run through the pad: you don't want thermal relief
  • the current doesn't need to run through the pad: there is no need to connect the pad directly on top of the trace
  • \$\begingroup\$ The current does need to flow from the pad into the trace, but I think thermal relief is acceptable because the gap is very thin and there may be many spokes \$\endgroup\$ – Mikhail Kagalenko Oct 8 '16 at 15:22

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