Micro-vias are used in high-density, mixed-signal, and high-speed boards.
To drive high-speed signals through vias, especially micro-vias, the via size, antipads surrounding them, and return-path GND vias must be located very carefully.
Having mentioned the above, an additional critical parameter affects "fine-tuning" via impedance.
This video exposes that parameter.
Keysight ADS SI tools were used for this Test Case.