Review my Three Terminal 0603 Footprint

[crasic]

I’m looking to implement a footprint for Device:C_Feedthrough based on mfg recomended landing pattern for an 0603 version of this device.

Murata NFM18PC105R0J3D

TDK YFF18PH0J105MT000N

The recomended footprints are similar but Murata is more zealous in specifying the recommended ground vias. I am not too comfortable with the via-in-pad for manufacturing purposes, but have experienced great and lasting pain from MLCC failures due to poor soldering that I would like to avoid that headache for this design.

Regardless my question is about the best way to approach soldermask and paste layers for this.

My current approach

1. Disable all technical layers for pads
2. Explicitly add paste and mask regions per recomendations with 0.1mm line size to keep it square to the pad

I am not sure how well this approach plays with global pullback/clearance specs and if they will be respected by the plotter.

3. For the TH variant, I am placing TH pads with only front copper enabled, I feel this is ok if it is tied to a ground pour or something, but with square pads this means there is no annular ring on the back.

In any case, please take a look at the footprints I came up with and see what you would change or recommend I do differently. Note that the pin numbers are wrong for the symbol in the default library

My preferred approach is in direction of variant 3, cleanest and only uses pads, not to bother with the internal exclusion for soldermask and let the rules take care of it, need to test more though

C_FEEDTHRU_0603_NFM18.kicad_mod (2.5 KB)

C_FEEDTHRU_0603.kicad_mod (2.3 KB)

C_FEEDTHRU_0603_TDK.kicad_mod (1.8 KB)

[Rene_Poschl]

Adding pads that only take care of mask (or paste) means that global rules are ignored. This is done because if you choose to go this way then you design something with stricter requirements than usual and do not want global rules to mess with it. (You already include the clearances in the pads)

For any other usecase you need to use pads with copper.

[crasic]

Is there a trade-off between using a mask-only or paste-only pad instead of a polygon area for those layers?

[Rene_Poschl]

I am not sure what you mean here. I thought i already included the tradeoffs in my last comment.

[crasic]

@Rene_Poschl

Adding pads that only take care of mask (or paste) means that global rules are ignored

I am asking for clarification

Does this applies to pads created as such , with no copper

or with a polygon object

Or both?

[Rene_Poschl]

I clearly state that this applies to pads without copper. No matter which type of pad.

I am however not sure what happens if you set the pad clearance to something different than 0. (I seem to remember that it either is ignored or that global stuff is still not added)