Altium: Back Drill / Controlled Depth Drilling table?

[toohec]

Does Altium support the creation of a separate drill table for back-drilled vias? If not, I figure I could use a unique via size and specify the controlled depth drilling info in the fab notes, but I was hoping that Altium supported it directly. Anyone have any tips or suggested methods regarding this?

Edit: Just in case, I'm using the latest Altium release. 14.3.15

 

[FvM]

I believe, your back drilled vias will also use an unique padstack, so it may be appropriate to define it as blind vias which also involves separate drill files.

 

[toohec]

I thought about setting them up as blind vias which would generate a separate drill table as intended. However, if I set them up as blind vias, I'll need to add keepout regions to the layers above or below the via that will be back drilled to ensure that there are no clearance issues during the back drill process. Unfortunately you can't setup a DRC check on this to catch missing keepouts so you are forced to rely on manual validation. Depending on the number of back-drilled vias, this may be ok. Is this what you were suggesting?

If I leave them as full via stacks from top to bottom, then it's easy to setup the appropriate DRCs, but I'm back to the original problem of not having a separate drill table for the back-drilled vias. If I leave them as traditional blind vias, then the fab costs go up since I'm introducing multiple lamination stages. I'd like to keep it to a single lamination process and utilize a much cheaper back drilling option.

I guess I could setup a custom multi-layer footprint with integrated keepouts that I could use. I'll think about that.

If anyone else has any suggestions, I'd appreciate it. Thanks.

 

[FvM]

Looks like you are spending considerably more time to find a "perfect" solution than any practical solution needs.

 

[toohec]

I don't consider 20 minutes to be a "considerable amount of time" if it helps me identify a process that will potentially save me significant time in the future. I'm using my original solution for now, but I was just curious if anyone else had a better method. There may not be one.

 

[marce]

Use a separate code for backfilled vias, the drilling info for these vias only can be extracted from the excellon data and a back drilling files created. Make the pad for these vias larger during layout on the back drilling layers to cater for the larger drill bit used, then make them zero before you post process.