What is Buried Via

What is Buried Via

A buried via is a type of via that connects only the inner layers of a PCB and is not visible from the outside. Unlike a blind via, which extends from an outer layer to one or more inner layers, a buried via remains entirely within the board. This type of via is particularly advantageous in HDI boards as it allows for increased density without the need for additional layers or increased board size.

Buried vias optimize the space and density considerations in PCB manufacturing, which is crucial for applications that require miniaturization and high-speed signal transmission. By connecting only the inner layers, buried vias help to create a more compact and efficient routing solution.

Buried vias are different from stacked vias and microvias. Stacked vias are laminated blind or buried vias that are built together around the same center, offering advantages such as space-saving, increased density, better routing capacity, and reduced parasitic capacitance. On the other hand, microvias are very small vias with diameters less than 0.1mm, which provide more routing space and lower parasitic capacitance. However, microvias require more drilling time and off-center via moves.