You can ask for a heavier weight of copper on the PCB (but that will be tge same on both sides). Check Finished Outer Layer Copper in: [https://jlcpcb.com/capabilities/pcb-capabilities](https://jlcpcb.com/capabilities/pcb-capabilities)<br> <br> Other PCB houses can do thicker copper. Also ask for the ENIG finish rather than HASL.

@andyfierman Would the copper extend past the solder mask? Basically I'd like the electrodes to be raised bumps to improve skin contact instead of being flush with the board surface.

"Would the copper extend past the solder mask?" That is up to you because it depends on how you create the copper area and control the aperture in the Solder Mask. If you create them as single layer pads then they will be exposed (and therefore plated) copper. How far in or out from the edges of the copper can then be set by a positive or a negative Solder Mask Expansion attribute value. A positive value exposes more, negative exposes less. Play with it and check the Gerbers in gerbvirxwhatever gerber viewer there is for OSX to see how it works. Note of course that the copper thickness is the same for all copper on the board.

@andyfierman I think you misunderstood his question - he is asking if the copper will extend in z axis past silkscreen height. <br> How I would do this is look for a component with a metal case which connects to a pin, and use that for smt assembly, I am sure there are some in easyeda.

e.g a battery connector contact, or smt metal nut.  or if it needs to be rectangular and look solid, some kind of smt metal sheild

@calum22161 Yes, that's what I meant. Thank you for the tip!