Introduction
Control the depth of drilling, so that it only drilled into the board to a certain depth of the location to stop without having to drill into the traditional drill plate as well.
Advantage
A. Back drills can reduce the equivalent of series inductance of the vias to meet the high-speed backplane signal transmission requirements.
B. Avoid the risk of warping caused by blind hole asymmetry design.
C. Simplify the process than the blind hole, reduce costs.
Application scope
High-speed signal transmission products
capacity of ability
Case
In order to improve the signal crosstalk and interference, the second half of the vias (the signal does not need to reach the site) through the deep drill to remove.