Definition

A micro-via is a small-diameter via (typically 75-150 µm) created by laser drilling rather than mechanical drilling. Micro-vias connect adjacent layers in HDI stackups, enabling high-density routing for fine-pitch BGAs. They have lower inductance and capacitance than through-hole vias, improving signal integrity. Micro-vias can be stacked (directly on top of each other) or staggered, with stacked vias requiring copper filling for reliability. Aspect ratio is typically limited to 0.75:1 to 1:1.