What thermal relief spoke-width to use on high current PCB

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1

I am designing a PCB which has a 230 Vac power section that has currents up to 10A.
As there are also fine pitch SMD components present (in a low voltage section of the PCB), I try to stick to the standard 2 x 0.035 mm copper PCBs. I can run the high current tracks on both sides of the PCB, so I have 2 * 0.035 mm of copper thickness. For 10A I then need about 3.5 mm track-width.

Using zone’s I can easily create tracks that are wide enough to carry the 10A

The question is about the thermal reliefs for the pads : (mostly THT, one SMD)

  • for maximum current there should not be thermal reliefs
  • for easy / reliable soldering, I think they are required.

If I have thermal reliefs with spoke width of 0.9mm, then 4 spokes equals the 3.5 mm track-width I need.

What are your recommendations in order to ensure good assembly / manufacturing while still respecting the track-widths ?

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Your approach with the thermal spokes is correct. Dividing your minimal trackwidt by the amount of thermal spokes is how its done.

Solid connections can work for SMD pads if both sides feature the equal amount of copper so they can heat up/cool down at the same rate.

For THT thermal spokes are mandetory otherwise the soldering iron would not be able to heat up the area quick enough as the planes act as heatsink and you would get cold solder joints.

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