7.2 Micro Via and Back-Drilled Via
(Ask a Question)The use of blind and buried vias for signals increases the cost of PCB compared to PTH via, as the micro via needs more precise tolerance control on the PCB for drilling and copper clearance.
In some applications, the PTH via needs to be drilled from one end of the board to get rid of extra via stub on high frequency signals. The back drilling increases the cost of PCB because of the increase in fabrication complexity.