Through-hole vias are the most common type and extend from the top layer to the bottom layer of the PCB. They’re typically used in less space-constrained designs or where higher current-carrying capacity is required. THVs are easy to manufacture and cost-effective, making them a go-to for standard multilayer boards.

However, they occupy valuable routing area on all layers and can create signal integrity challenges in high-speed or impedance-sensitive applications. Despite this, they remain widely used in both prototyping and full-scale production.

Blind vias connect an outer layer of the PCB to one or more inner layers without going through the entire board. This makes them ideal for designs where board space is limited and layer density is high.

By reducing via depth, blind vias help preserve routing area on internal layers and minimize parasitic effects that can impact signal quality. They are more complex to fabricate than through-hole vias, requiring precise depth control, but bring clear benefits in compact, high-performance layouts.

Buried vias connect two or more internal layers of a PCB without reaching the outer surfaces. They allow designers to increase layer count and routing density without consuming space on the top or bottom layers. Because they are hidden within the board stack, buried vias can help maintain clean outer-layer layouts for critical components, high-speed signals, or impedance-sensitive traces.

These vias require sequential lamination during fabrication, which increases manufacturing complexity and cost. Still, they’re often necessary in tightly packed, multilayer designs.

Microvias are small, laser-drilled vias typically used in high-density interconnect (HDI) PCBs. They usually connect only adjacent layers and have a much smaller diameter than mechanically drilled vias. This allows for tighter trace routing, improved signal integrity, and more design flexibility in compact devices like medical instruments or aerospace modules.

Microvias are especially valuable in designs requiring fine-pitch components or multiple high-speed signal layers. Though more expensive to produce, their performance advantages often justify the added cost in demanding applications.

Skip vias connect non-adjacent layers while intentionally bypassing the intermediate ones. They are often used in high-density PCBs where space is limited, and design constraints prevent routing through each sequential layer. Skip vias are created using laser drilling and typically appear in advanced HDI stackups. Their main advantage is routing efficiency. They allow connections that avoid congested inner layers.

However, their fabrication requires careful planning and process control, which adds to manufacturing cost. They are best suited for compact, multilayer boards requiring advanced layout strategies.

Via-in-pad places the via directly beneath a surface-mount component pad, saving space and shortening the signal path. This is especially useful for high-speed or high-frequency designs where minimizing inductance and improving thermal performance are priorities. VIPs are common in dense layouts that use fine-pitch BGAs or RF components.

To prevent solder wicking, these vias are usually filled and capped during manufacturing. While they simplify routing in tight areas, VIPs increase fabrication cost and require coordination between layout and assembly teams.

Backdrilled vias are through-hole vias that have unused stub portions mechanically removed after plating. These stubs can act like antennas at high frequencies, causing signal reflections or loss. Removing the unused sections improves signal integrity in high-speed digital designs, particularly those using differential pairs or controlled impedance traces.

This technique is often used in aerospace, networking, or defense systems where clean signal paths are essential. Backdrilling adds processing time and cost but can be critical for meeting strict performance requirements.