Copper pads only

Layout Footprints
1

I need to have a small board that I need two sets of the copper pads (1x4mm, 32 small pads and 32 bigger pads, 1.5x10mm), no other components.
Where should I start?
thanks

2

Itā€™s probably best to create your own footprint in the footprint editor.
You can either create a simple footprint, and then place an array of them on the PCB, or you create a footprint with an array of pads, and then place that on the PCB. Or you create some mix. For example one footprint for the big pads, and another footprint for the small pads.

A lot of people have some sort of aversion against creating or modifying footprints, and I donā€™t really understand this. One of the reasons I started using KiCad (some 10+ years ago) was because both the symbol and footprint editors in KiCad are quite good and have a similar look and feel as the schematic and PCB editors.

3

Thank you for the advice. Before I always with Schematics and board. Without schematics, I can still do footprint and generate the PCB?

Thanks

4

you can place pad on pcb without schematic and make array of pads

5

Unfortunately this is not so.
You can place a pad in the footprint editor as a new footprint as paulvdh states. To do this you first create a personal library in which you name and then create the footprint with the pad.

Alternatively, you place a footprint on the PCB and edit out everything but the pad, then modify the pad to your requirements then create an array or duplicate the pad 'till you have enough pads to make your footprint. This method cannot be saved for future use without a personal global library.

6

Iā€™m sorry, I didnā€™t put it right, donā€™t put a pad, just a filled rectangle and create an array

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7

That way your ā€˜padsā€™ will be covered by solder mask so for me they are not pads.

8

Thatā€™s good point.
How to do filled rectangle? I can draw rectangle, but how to fill it?
Thanks

9

Just change the corresponding property. :grinning:

10

I meant in footprint editor or CB board? Also can you do array this way as well?

11

1 in the same way, you can make polygons in the mask layer
2 if this does not contradict the objectives of the task, then you can simply not order the application of the mask from the manufacturer of the circuit boards.

12

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13

Thank you, I got it.
When I run DRC, it says ā€œtrack has no-connection end?ā€. 9 of them

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14

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15

What are you really trying to do? A breakout board? You can add a footprint to a board without a schematic if you insist. Using graphical rectangles isnā€™t a right way to do this. If you donā€™t find a ready made footprint to modify, you can create a new one with the footprint wizard. With the wizard you get the dimensions and locations right without copying or making an array. Hereā€™s an example (extra items in graphic layers can easily be deleted later:

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QFN and QFP could be good wizard candidates.

The left/right side pads should also be footprints (or even one footprint).

16

Yes, itā€™s possible to just put some footprints on a PCB, and then draw tracks between pads.
But that would not be my approach for:

For a PCB like that, I would start by creating a project, opening the schematic editor, and then:

  1. Put a single row 32 pin connector on the schematic.
  2. Make a copy of the connector, mirror it, and then put it on top of the other.
  3. Move one of the connectors a bit to the side. You can now see & verify that KiCad has created 32 connections between the two connectors.
  4. Assign a footprint of a QFP (I assume that is what is on your PCB) to one of the connectors.
  5. Create a footprint for the other ā€œICā€. and put it in a project specific library (It has to be in some library).
  6. Back to the schematic, and link the ā€œotherā€ connector to the newly created footprint.
  7. Update PCB from Schematic [F8].
  8. Position footprints, draw outline, draw tracks.

This method may seem a bit difficult, but it only uses regular KiCad design paradigms. The advantage of the schematic is that it lets KiCad know what connections should, and which should not be made, and KiCad keeps clearances. And you can use DRC. If the footprints have been placed, and the netlist is present (from the schematic) then selecting one footprint and then pressing [Shift +F] probably draws nearly all the tracks for you.

Without the schematic, you can draw a track between two pads, but evertything is part of the No Net net, and KiCad does not know it should keep clearances from the other pads, and DRC does not work. To fix that, you have to:

  1. Draw a track between pads.
  2. Create a new net name for this (which adds the pads).
  3. Repeat these steps another 31 times.

Manually naming all those nets is a lot of work, and you also have to draw all tracks manually.

17

Thank you for giving me detailed instruction.

I made a 32 pin QFN saved to the project library and made another 16x2 footprint and also saved to the same library. Why every time, I edit one footprint, the other one would disappear from the library?
Also how do you save the footprint in footprint wizard?

18

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this is one

19

when i switch to the other footprint in the library, it give me this warning:

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20

If you open a footprint in the editor and make ANY changes then try an open a different footprint you will get a warning that the change you made has not been saved yet . . . .