pcb-designpcb-fabrication
We want to design a pcb module that should be soldered directly onto customer pcbs (exactly like ICs ect.)
I found a module which does exactly that, please see pdf.
https://www.dropbox.com/s/ky2u9z83ja6snsh/pcb_pads.pdf
But how are these pads made i the pcb layout tool?
It looks like Plated through holes which has been placed half en pcb edge.
Generic pin headers are in the "pinhead" library. For something like the breakout board with multiple rows of headers, you can just place them in the proper locations on the board layout.
That said, do you even need to create a PCB? Since everything is on .100 inch centers, you could just get a protoboard, and solder your connectors on with point-to-point wiring.
If you want to go to the trouble and expense of making a proper PCB, you may want to consider starting from the Fio design files and integrating the motor driver on-board. The connections will be more secure, and you will save the mass of the extra PCB.
This is not a direct answer to your question, but I think it's quite relevant.
A few years ago, we did the same thing. We made little daughter boards that used edge castellations to solder it onto the mother board.
The difficulty was that we had components on the bottom side of the PCB. These were the vital decoupling capacitors needed by the chip.
So the motherboard had very large vias to accommodate these components.
You can see several large round holes in the PCB. Through the holes you can see the capacitors on the flip side of the daughter boards. Since the holes are just large vias, they end up through-plated (our supplier doesn't offer unplated holes), so you have to be careful that the plating doesn't short any pads on the daughter board.
A few thoughts about using pads under the PCB. I assume you mean something like this Telit HE910 module:
Which reflow solders directly onto a PCB. Notice that in the picture the gap between the module and main PCB is not zero, but certainly less than 1mm. Clearly this technique works. Whatever components are inside the module don't mind undergoing an extra reflow process. This is because components can usually survive at least two reflows (once for each side of the board). Since those modules only have components on one side of the PCB, they have almost certainly experienced only one reflow.
Instead of reflow, you might be tempted to use a hot plate to solder a module like this. This would enable you to solder the module down without getting the components inside the module too hot. However, I would advise against this method. At the moment the solder solidifies, the mother PCB will be much hotter than the daughter PCB. As the mother cools and shrinks, it will generate shear forces in the solder joints, and may warp.
Best Answer
Those are called Castellated Vias, Castellated Holes, or half-holes, depending on what your board-house likes to call them.
Typically to have them in your design, you simply place a pad in the middle of your board outline route path, and then simply let your board-house know that your board has castellated vias.
If you want unusual pad profiles, you may need to draw up a custom pad shape as a special component.
Generally, if you have any questions, you should talk to your board-house to see if they can indeed do castellated vias, and how they want you to indicate them on the PCB layout.
See the electronics.stack-exchange question regarding Castellated Holes here.