Complete Guide to Via Selection in PCB Design

July 15, 2026

1. Three Main Types of PCB Vias

PCBs mainly adopt three categories of vias with distinct structures and application scenarios:

Through-via
It runs straight through the board from the topmost layer to the bottommost layer. Its manufacturing process is simple with low cost. However, it penetrates all intermediate wiring layers and may introduce interference to other traces.

Application: Regular PCB projects with tight budgets and low wiring density requirements.

Buried-via
It is entirely embedded inside the inner PCB layers without connecting to surface layers. It significantly reduces signal crosstalk and improves wiring density, yet it features complicated fabrication procedures and higher production costs.

Blind-via

It only connects one surface layer to a single inner layer without piercing the entire PCB. It saves layout space and mitigates signal interference, but its processing difficulty and price are higher than through-vias.
Application: High-performance & high-density boards such as high-end server motherboards and smartphone mainboards.

Quick selection rule: Choose through-vias if you have limited budget and low wiring density demands. Adopt blind and buried vias for products requiring superior circuit performance and dense routing.

2. Select Via Specifications Based on Current Magnitude
For high-current traces like power lines and ground wires, the current-carrying capacity of vias becomes a critical design factor. Larger via hole diameters and thicker copper foils support higher current loads.

For circuits carrying heavy current, vias with a diameter ≥0.5 mm and copper foil thickness ≥35 μm are recommended to prevent overheating or burnout caused by insufficient current capacity.

Current Carrying Capacity Table for Vias (10℃ Allowable Temperature Rise)

3. Design Vias According to Heat Dissipation Requirements
Heat dissipation is a key consideration for vias near power components. Two methods can boost thermal performance:

Expand the diameter of single vias;
Increase the quantity of deployed vias.

Practical solution: Arrange dense through-vias on and around the thermal pads of high-power components, and connect them to ground planes. This rapidly transfers heat from components to the opposite side of the PCB for heat dissipation via heat sinks.

4. Consider PCB Manufacturing Processes

Confirm the production capacity with your PCB supplier before finalizing via selection. Some small manufacturers cannot fabricate fine blind/buried vias, or suffer from low production yield for such processes, making even optimal designs unmanufacturable.

5. Comprehensive Summary of Via Selection

Designers must take five core factors into account when choosing vias for PCB layout: via type, signal operating frequency, circuit current magnitude, component heat dissipation demands, and manufacturer’s processing capability. Balancing all factors enables designers to develop PCBs with reliable performance and reasonable costs.