Arbitrary pad shapes


#1

Hello, people!

I’m trying to create a footprint with a ring shaped pad (ether round or square with rounded corners). With very little luck.

I’m not afraid to edit “.kicad_mod” file by hand if need arises. There just doesn’t appear to be syntax for that.

Is it at all possible to do with kicad?


#2

Hm… not really straight forward to do at all.
Let’s turn the question around: What do you want to achieve? What is your end goal? Why the ring shaped pad?
I ask, as you might not really need a ring shaped pad and something else that does appear similar on the finished pcb will do the job just fine…


#3

Did this for an ultra low profile push switch from Snaptron.
Draw a ring in silkscreen, with a thick trace then edit the properties to the appropriat copper layer. Accept the warning and then place an SMT or through-hole pad in the ring, to allow traces to connect.


#4

Ok, so .tiff doesn’t seem to work.
ring_pad.tiff.pdf (114.7 KB)


#5

Right now I’m trying to create pad for bottom-port MEMS microphone.

Page 20 of the design guide shows the land pattern. Page 16 has info on the the pad itself.

It was suggested in another topic to use ordinary TP pad. No, the hole must be NTP. It is also smaller than the inner diameter of the pad itself.


#6

That seems to “kind of” work. If there’s no better solution, I’ll take it.


#7

Browsers really like GIF, JPG or if it’s vector based SVG.

@partisan
The NPTH in the center is possible with KiCAD, just check the options for the pads… there is one for NPTH.


#8

One of the downsides of OSX: .tiff is the only format produced by the screen grabber. .pdf comes from the print utility. To get anything else, I have to put it through GIMP or a format converter.


#9

I do it all the time… resizing and sharpening inclusive, as otherwise people would end up with 1680x1050 screenshots from me :wink:


#10

Would this also be the best way to create this Snaptron footprint? http://www.snaptron.com/products/pcb-pads/double-sided-contact-pad/ I am trying to create the 8.5mm version and am struggling. Thanks for the help


#11

Look at the photo on the right side of the page “What type of plating”
You can see the outer pad is made of rectangular pads rotated at 0, 45, 90 degrees and so on approximating a circle


#12

I’m looking to solve this kind of problem for a MEMS microphone

I get the workaround using the silk layer to make the ring and then changing the active layer to move it to the copper. But note the stencil apertures. I’m thinking that the only way to do this is to follow the same workaround and make the four arcs for the stencil in the silk layer and then move it to the paste layer. Is that the only way to make this kind of arbitrary pad and stenci?


#13

Also for the solder mask layer. If not, all the tin paste will be mixed up while soldering after the stencil is removed.


#14

Yes @pedro I see that I have to build the entire pad by hand

copper layer
paste layer
solder mask layer

I guess I’m glad that KiCAD allows for this kind of ‘freedom’, and I could also generate designs as bmp files and then import them and move them to the different layers as well.

Cheers


#15

If you run a current nightly (or with kicad 5 which will be released within the next few days if we are lucky) you can use kicad stepup to create such a pad including the paste pads.
(The current Stepup converts circular features to polygon pads)

More details about stepup and footprint creation:


#16

The work around works

And I’m looking forward to KC5!