Copper-lined through-holes

I am looking at sending a PCB design to a manufacturer for the first time and I need some help with the practicalities.

My project uses several proprietary breakouts mounted on my PCB. As usual I expect to mount the breakouts on the top side of a two-layer board and solder all the pins to pads on the B.Cu layer. One of the sub-units is an Arduino Pro Mini (the brains of the outfit) which has a footprint like this
ProMiniFootprint-640x480
I have been puzzling over how to connect traces on the F.Cu to pins soldered to B.Cu. I am told that holes in commercially-made boards are copper lined allowing such connection but I still don’t quite get it.

When I use PcbNew to place a footprints such as the above and send the details off to a manufacturer, does the top layer also have on F.Cu pads where shown connected to the pads on B.Cu? When I draw a trace between pads on F.Cu does this connect to the pins on the breakout soldered to B.Cu?

open your pad properties, in the layers setting。 you can see the copper item。 it has three choice
1.F.cu
2. All copper layers---- this is the right choice
3. B.cu

in the pad type, pls select through-hole

If you order plated through boards, then yes, hole are copper lined.
See https://en.wikipedia.org/wiki/Printed_circuit_board

These days, plated-thru is pretty much the default, unless you are etching your own boards.

If you go the files.plot.generate drill files, you will see a counts for Plated Pads and Non-plated pads

If you query any pad properties, you can see pad type. Through hole means plated, and NPTH, mechanical
means Not Plated Through Hole

Kicad can manage both, and creates two drill files to handle all this.
Plated holes are drilled very early in the FAB process, and are then copper-plated through whilst non plated holes are a second pass at drilling, much later in the FAB process and that drill is not plated.

Thanks folks. That clears up a lot of things.
BTW: after first posting here I cam across
https://electronics.stackexchange.com/questions/232595/why-are-through-holes-plated-in-pcbs
which was interesting. Might be of help to others with this issue.

As far as the actual connecting the two boards together (the pro mini to your board), the convention is to use 0.1" header pins. (Make sure the holes in your board are large enough to accept a 25min square pin (remember, hole must be a little larger than the diagonal of a rectangular cross-section pin), this is larger than regular IC pins.

For reference, here is a 3D view rendering of one of my boards that also has a pro mini mounted to it.

Off topic… Does anyone have colorized 3D models of standard Arduino boards? Are you allowed (licensing reasons) to submit them to the official 3D model archive?

@SembazuruCDE Did you mean “mil”?

I almost got bit by this on a board I just had done. Very glad I double checked before sending the files out.

Yes, I meant mil. Sorry for the type-o.

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