F.paste and F.Cu layers

Hi all,

I would like to modify the F.paste layer of my PCB without modifying the others but after several attempts without suction I realized that the F.paste and the F.Cu are linked.
My question is how to modify the elements of the F.paste layer without touching those of the F.Cu layer.

Thank you in advance

I guess you have footprints in your design. The copper pads and the paste apertures are in the footprints – naturally you can’t make them independent, because both are defined by the needs of the physical components.

Tell us how and why you would to modify them and maybe there’s some solution for you.

It is a microcontroller, here is its footprint attached. At the moment of welding it puts me short-circuiting


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In Pad Properties dilog box (in footprint editor) you can uncheck the F.Paste checkbox and add your own pads located only at F.Paste (by selecting the Copper: as None.

I’m sure there are like this footprints in KiCad library that have different paste then copper. Just look how they are done.

Piotr, i didn’t find any footprints like that. I use the 5.1.6 version of kicad

Do you have another solution for me please ?

You might find something useful from Tutorial: How to make a footprint in KiCad 5.1.x (From scratch)?.

Mostly you want and need Solder paste clearance. First, there’s the project value.

Most of the times you want some sane value there which is good for most of your components (for example 0402 or 0603).

Then each footprint has its own value in the Properties which overrides the global value. This is probably what you want here.

Finally each copper pad has the same property which overrides both the above mentioned.

And as Piotr mentioned, it’s possible to disable the pad layer for each copper pad and create “aperture” pads which have only paste layer and are independent. But mostly you don’t need them except when the paste hole shape is different than the copper pad shape. For them, see the tutorial and the “Exposed pad” example above.

BTW, I’m not sure if you know the meanings of the layers. If you hand solder with an iron and solder wire you don’t need to care about the paste layer at all, but what you need is the mask layer which has holes which expose the copper. See How does solder mask layer work? for that.

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I would redo the trace connecting pad 36 to the center pad. It currently reduces the distance between neighboring pads (and i assume at least part of it is exposed depending on the soldermask clearance)

En example of what I was thinking about (I switched off visibility of F.Cu to see F.Paste):

If it is not what you are looking for then I don’t understood what you wont.

Yea the default colours of kicad are shitty with regards to checking footprints as copper and paste have basically the same colour. I suggest to change at least the paste colours or you can even look at https://github.com/poeschlr/kicad-color-schemes and use a colour scheme from there.

Ok thank you. I will that

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