[HH] one layer deep micro vias

[Tom Metro]

Drew Van Zandt wrote:
>Tom Metro wrote:
>> Seems like another good way to ward off clones, unless this technique is
>> widely known.
>
> Lasers to make one layer deep micro vias is a standard technique. 

Good to know.


> I have used it in board designs at least ten years ago...

I don't know about laser involvement, but I thought blind vias were
common in multi-layer boards dating back to the early 90's. Around that
time there was high volume production of PC clone motherboards that were
multi-layer (and in fact that was a marketing bullet point).

While I suppose all the vias might have been through hole, I had the
impression they were able to do blind ones as well. Shouldn't this be
possible using traditional drilling and plating techniques? The laser
technique gives the impression that the holes are made after the layers
are sandwiched together, but shouldn't it be possible to use traditional
via techniques to join layers that are on directly adjacent sides of a
substrate?

 -Tom