EasyEDA does not support Z-axis milling. AFAIK, JLCPCB do not support Z-axis milling or the production of Z-axis milled PCBs but if you change the **Category** of this topic to **JLCPCB** then you may get a faster response from them. [https://jlcpcb.com/capabilities/Capabilities](https://jlcpcb.com/capabilities/Capabilities)

It may be easier to design around a 0.8mm thick PCB (half thickness). That still meets your requirements of 2.0mm total thickness. Nothing in your design would need changed, just when you go to order choose 0.8 for board thickness.

I don't know which EDA and factory can do this, any images? @usersupport

@UserSupport : It is not a standard EDA feature. It was just to ask it it was possible. Here some examples: [Milling - Multi Circuit Boards (multi-circuit-boards.eu)](https://www.multi-circuit-boards.eu/en/pcb-design-aid/mechanics/milling.html)<br> <br> [Milling of PCB - Engineering Technical - PCBway](https://www.pcbway.com/blog/Engineering_Technical/Milling_of_PCB.html)

@tiger54, You may be able to do what [https://www.multi-circuit-boards.eu/en/pcb-design-aid/mechanics/milling.html](https://www.multi-circuit-boards.eu/en/pcb-design-aid/mechanics/milling.html)<br> <br> describes in EasyEDA by putting the required milling information in the Mechanical layer but you would have to talk to [https://www.multi-circuit-boards.eu/en](https://www.multi-circuit-boards.eu/en/pcb-design-aid/mechanics/milling.html)/ or possibly [https://www.pcbway.com](https://www.pcbway.com/) (who seem to have ripped off Multi-Circuit's images!) about that, not JLCPCB. I doubt that they will be able to do what you are asking about in terms of having tracks exposed in the milled out layer however. I think cjohnson's suggestion is a more practical and far less specialised way to explore.

You can get the effect of having a milled PCB by using two 0.8mm boards. The top board would have a center cutout the size of the OLED display and castellated edges to connect the necessary traces to the second board. The second board would have the holes to solder the OLED to it. Note that you can put all the components (except the OLED) on the back side of the bottom board, plus more components on the front side of the top board. As an example, lets say you want to build a hand-help gaming device, you can put surface mount buttons on the top PCB board and connect them electrically to the bottom board using castellated edges, then the bottom board would have all the surface mount electronic components on the backside, and you'd just solder the OLED to the front side. Then you'd sandwish the two boards (with the OLED poking through the opening of the top PCB) and solder the castellated edges.

If this is a hobby buy a CNC1610 and mill it yourself.  Be aware that fiberglass dust/particles are a health risk and must be taken care of (vell ventilated area and milling either in oil or water). Not sure what the smallest bit size is you can use on those but 2 mm shouldn't be an issue on even the cheapest CNCs. Cost? The prototype Z-milling option probably cost as much as the mentioned CNC1610. @andyfireman You can mill down to inner layers but this is a job requiring manual work/oversight. Also, you need at least a decent mill. Copper foil is 35µm so the "tram" must be dialed or you need to use very small bits/stepover which would make it a slow process.

@xenons, "Copper foil is 35µm..." 35um equates to a 1oz copper weight which is most commonly used on the outer layers. Unless it's a specialised stackup, the inner layers (that are being milled down to) are usually 17.5um or 0,5oz copper so it's even more of a tricky task.

Especially for larger areas. like a display. So you would mill out the pocket and only where the contacts go down to the copper layer. In a nutshell: mill, visually check how much further you need to go, add a few µm to the depth and repeat until you get it right. Normally I only do this when I screwed up the inner layer and need to run a mod wire/cut trace. The bigger issue is finding a clear path from the top to the inner layer and having the position accuracy to precisely hit the trace.