Problem designing PCB for SMD part

I’ve created a part for an SMD device (actually a carrier board, an ESP-12), but apparently I’ve done something wrong with my PCB layers.

I added copper pads to both top and bottom layers, under the assumption that Fritzing would supply the copper to connect the top and bottom layer, just as it does for through-hole components.

Nu such luck: when I use the part I get pads on both top and bottom layers of the PCB, but they’re not connected.

I presume things would have worked correctly if I had only added copper to the top layer (would it?), but could I also have instructed Fritzing that I want the top and bottom layer connected?

And why does the autorouter think that the top and bottom pads are connected? Because it’s routing some of my connections on top, and some on the bottom…

Can you post your part so we can look at it for you?

One way to connect the top and bottom copper pads is to run a via through them. Another way is to use this part that already has copper through-holes with copper pads on the top.

You don’t need to use the six pads on the bottom if you don’t need them…

PS. I wouldn’t bother with Autorouter, route them all by hand…

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Aren’t identical pads top and bottom always plated at manufacture so they are connected, or is there a special FZ XML command in the svg.

Is he talking about not connected when you layout a circuit, like you connect a wire to it on the bottom but the top isn’t connected. Sounds like something to do with pin assignment.

I have fixed the practical problem, in the mean time, by (a) removing the bottom copper layer in the SVG and (b) setting the part to SMD in the connection editor. I’m unsure which of these fixed it (or maybe both are needed?).

But in my opinion it’s really a bug that the autorouter thinks the top and bottom layer are connected (without me providing a via), whereas the fab process doesn’t connect them.

It’d be nice to have some real documentation on the file format and the intricacies of the multilayer SVG files and how they’re (presumably) converted into multiple SVG files internally. What exists glosses over details (specifically for niche areas like SMD components).

Aside question: I searched long and hard for an ESP-12F without a 2.54mm carrier board (at least for the PCB) but I couldn’t find it. So in the end I started with Matthijs Westerhof’s part with carrier board and modified that.

How should I have found the parts you’re mentioning? They’re almost exactly what I needed (although my part has the carrier board in the BB view, similar to most SMD parts for adafruit and such).

Download the .fzpz from the link I provided. In FZ, go to the top right corner of the part menu and click on the icon with 4 little lines. Click on Import, navigate to the Download folder (windows) and click on the part you just downloaded. The part will be in My Parts bin. Click on the 4 line icon again and click Save Bin.

The ESP-12 is not attached to a breakout board in the breadboard view, Just attached wires directly to the ESP connectors.