Electronic circuit board is composed of different conductive layers,When you need to make different layers connected together on electric,Usually use a through hole pcb circuit board. So blind hole means through holes in the circuit board. For example, 4 layer, between the first layer and the second layer, secone layer and the third layer. The circuit board with blind hole is called blind vias hole board.
Crossed blind vias hole,only laser drill machine can do it. And we can.
Compact blind vias hole, also need laser drill hole.
Any difficult and high precision pcb board is available here.