FEDEVEL
Platform forum

Arda , 11-27-2025, 01:14 PM

Hi all,

I’m creating a VPX connector footprint in Altium Designer and ran into a problem: I can’t use blind vias inside the library footprint.

I want to define pad stacks with blind vias (for example L1–L2, L1–L4, etc.), but Altium doesn’t seem to allow blind/buried vias at the library level. Since the actual board stack-up will change per project, I’d like the footprint to stay generic—but I can’t figure out how to do this.

Is there a reason Altium doesn’t allow blind vias in the library?
And what’s the recommended workflow for VPX connectors where blind vias are required?

Thanks!

QDrives , 11-27-2025, 02:45 PM

In a quick test...
Altium allows it, but you cannot define it from the library.
You can:
1) create a board
2) Do the stack-up and via types
3) Place some vias
4) Have the same stack-up in the library
5) Copy the vias and place them in the footprint library

Arda , 11-27-2025, 05:39 PM

In my testing, Altium does allow blind/buried vias—but only at the PCB level, not inside the footprint library. Footprints have to remain stack-up-agnostic, so you can’t define blind/buried via pad stacks in the library itself.

What I’ve been doing (and what seems to work reliably) is:

Create the pads normally in the footprint library
– Just standard through-hole or SMD pads, no blind-via definitions.

In the PCB document, define the real stack-up and the blind/buried via types
– For example L1–L2 microvias, L1–L4 buried vias, etc.

After placing the footprint, add the required blind vias directly in the PCB
– Either by placing “via-in-pad” or converting existing pads to the proper via type, depending on the situation.

This keeps the footprint generic while still letting me implement the correct HDI via structure for each specific board’s stack-up. Since Altium doesn’t currently support defining blind vias at the library level, this seems to be the safest and most flexible workflow.

I’m still open to suggestions if there’s a cleaner way, but so far this is the most practical approach I’ve found.

QDrives , 11-28-2025, 02:24 AM

I just tested that it is possible to have the blind via in the footprint (library).
The problem is, that the layers for the via stay the same even if you place the part on the bottom.
Create an Ideas item at Altium for get it exactly the way you want.