How to tent in-pad vias? (for thermal pads)

[bluewave]

Yes, here is the document I was originally looking at. I hadn’t come across this either (am not experienced), just looking at what the manufacturer was recommending.

https://www.ti.com/lit/slma002

[maui]

@bluewave

Easiest to just have it defined in the mask layer gerber, then there is no need for notes to the fabricator?

it possible with a bit of working, creating a footprint with the right mask zone, using polyline pads (drills 0.3, mask 0.1 annular larger)

[Naib]

or you could do something like this:

– edit –
an example HSOIC8

[eelik]

@bluewave

Easiest to just have it defined in the mask layer gerber, then there is no need for notes to the fabricator?

Unfortunately not, Solder Mask Defined is required to be communicated through notes by some manufacturers, and I have received a set of boards where a couple of them was modified by hand, apparently someone tried to scrape off some mask with a sharp object after manufacturing, but then they gave up and the rest of the boards were intact. Only later I understood that they didn’t understand we wanted the mask just like we had defined it.

[maui]

just for fun I’ve tested this footprint w/ polyline pads… and here the result:

produced without having to communicate any special instruction to the manufacturer and tenting the thermal vias in the thermal pad to reduce solder loss.