Through Hole Via vs Blind Via vs Buried Via in PCB Design: Key Differences

In PCB design, a through hole via passes through all layers of the board, a blind via connects outer layers to one or more inner layers without going through the entire board, and a buried via connects only inner layers and is not visible from the outside. These via types differ mainly in their depth, manufacturing complexity, and cost.

Quick Comparison

Here is a quick table comparing the main features of through hole, blind, and buried vias in PCB design.

Feature	Through Hole Via	Blind Via	Buried Via
Definition	Passes through all PCB layers	Connects outer layer to inner layer(s)	Connects only inner layers
Visibility	Visible on both sides	Visible on one side only	Not visible externally
Manufacturing Complexity	Simple	Moderate	High
Cost	Lowest	Higher than through hole	Highest
Typical Use	General connections, power, ground	High-density boards, space saving	Very high-density inner layer routing
Drilling Required	Full board thickness	Partial depth	Inner layers only

Key Differences

Through hole vias are drilled completely through the PCB, connecting all layers. They are easy to manufacture and cost-effective but take up more space and can limit routing density.

Blind vias connect an outer layer to one or more inner layers but do not go through the entire board. They save space on the PCB surface and allow for higher density but require more precise drilling and increase manufacturing cost.

Buried vias connect only inner layers and are completely hidden inside the PCB. They enable very high routing density and complex multilayer designs but are the most expensive and complex to produce due to precise drilling and layer alignment.

Through Hole Via Example

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PCB Design:
- Drill hole through entire board thickness
- Plate hole with conductive material
- Connect all layers electrically

Result:
- Simple via connecting top to bottom layers and all inner layers

Output

A hole drilled through the entire PCB connecting all layers electrically.

Blind Via Equivalent

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PCB Design:
- Drill hole from outer layer only to a specific inner layer
- Plate hole with conductive material
- Connect outer layer to selected inner layers

Result:
- Via visible on one side only, saves surface space

Output

A hole drilled partially into the PCB connecting outer to inner layers without passing through entire board.

When to Use Which

Choose through hole vias when cost and manufacturing simplicity are priorities and space is not limited, such as in low to medium density boards.

Choose blind vias when you need to save surface space and increase routing density but want to keep costs moderate, common in multilayer PCBs.

Choose buried vias for very complex, high-density multilayer boards where inner layer connections are needed without affecting outer layers, despite higher cost and complexity.

Key Takeaways

Through hole vias go through all PCB layers and are easiest and cheapest to make.

Blind vias connect outer to inner layers, saving surface space but costing more.

Buried vias connect only inner layers, enabling high density but with highest cost.

Use through hole vias for simple designs, blind vias for moderate complexity, and buried vias for advanced multilayer boards.