|And what would via hole diameter be, and how are they made. How are the layers aligned and stacked, are they done like laminated pcb, or is the entire structure built up layer by layer by deposition and etch more like an IC?|
All good questions. None of which I have real answers for. Now I suspect that the vias are probably small enough that they have to be laser drilled. And for small volumes, that can be horrifyingly expensive. That isn't a NRE, though. And I suspect that if it is done more routinely, there is no reason why it can't be cheaper.
Regardless, it would be interesting to know what the costs are. And what effect volume has. If this is something that can be justified in a production run that numbers in the thousands, it can be a real game changer.