Components Under Footprint of Other Component

Layout
1

I’m a newbie in circuit-design, so this is probably an odd question:

I’m trying to design a PCB for a control-board, to be mounted on top of an existing PCB using headers. My board therefore has to have pads for male/female header pins in exactly the right places to line up with counterparts on the mainboard.

My initial thought was to create a eeSchema library item for the mainboard, so I could draw up a schematic of the my control board. I thought I could then make a footprint module for the main board, with pins in exactly the right positions.

Does this sound like the right way to go? If so, would I place my custom module on the back of the PCB in PCBNew?

It also occurred to me that I might not be able to place other component on the back of the board, under the footprint of my custom module. Even though there will physically be space to do this, KiCad will not know that the main and control boards will be separated by the male/female headers, with space for components between them. Is this going to be a problem?

Cheers, and sorry for the silly questions.

a|x

2

Whatever works!

Kicad doesn’t care about the z-dimension of parts, you can place as many as you like “on top” of each other, as long as there is no interference of copper. It is up to you to decide what makes sense or not.

3

Ah, I see. I’ll just go ahead and do that, then.

Thanks very much,

a|x

4

I’m not sure if I exactly follow your question.
If you are planning on first drawing something to represent the existing main board that your new module will fit on… then I don’t see the benefit.

I would just draw the schematic of the new module including the connectors with the right number of pins to mate up with the existing “mother” board.

then when you associate components to the schematic elements make sure the connector footprints match the pitch of the mother board.

Then when you lay out the pcb pay very close attention to the placement of those mating connectors with regard to spacing, etc.

You can use the ruler at the bottom of the window to make measurments.
If you place your cursor at a given point then hit the space bar you will then see relative measurement (dx, dy) from the point where your cursor started.

Also get yourself a set of calipers ($15 at harbor freight) to make precise measurements of the motherboard.

Hope this helps
dwight

5

I Have a few PCB designs where I have a daughterBoard that use interconnect headers.

It was just a simple matter of copy&paste the area to new PCB, [this was in DXP2004],
unfortunately PCBnew doesn’t copy/paste between open pcb designs. (hoping this feature will b include in future release)

so you could save as or copy PCB file to new & delete all but your control board elements. Ive done it this way as well. Alignment of interconnect is perfect.

6

I Have a few PCB designs where I have a daughterBoard that use interconnect headers.

It was just a simple matter of copy area of PCB to new PCB, this was in DXP2004,
unfortunately PCBnew doesn’t copy/paste between open pcb designs. (hoping this feature will b include in future release)

so you could save as or copy PCB file to new & delete all but your