In PCB (Printed Circuit Board) design, a via refers to a hole drilled in the board that electrically connects two or more layers of the board. Vias are used to create a conductive path between layers of a PCB, and they can be plated with metal to ensure a continuous electrical connection between the layers. Vias can be of different types, such as through-hole vias, blind vias, and buried vias, each with a different purpose and function in the PCB design. Vias are essential to modern PCB design, allowing designers to create complex and high-density circuits on a single board

 A computer-generated cross-sectional view of a multi-layered PCB: 1. Blind Vias; 2. Buried Vias; 3. Through-Hole Vias 

What are Blind Vias?

Blind vias are an essential component of modern printed circuit board (PCB) design, specifically multi-layered PCBs. They are small holes that are drilled into the board to connect the different layers of a PCB. Blind vias are called so because they only go partway through the board, stopping at a specific layer rather than running through the entire board. This allows for the creation of more complex and compact board layouts, making them ideal for modern electronics with smaller form factors. Blind vias are used to route signals and power between layers while minimizing the number of layers needed, reducing the overall cost and size of the board.

What are Buried Vias?

Buried vias are an essential component of modern printed circuit board (PCB) design, specifically multi-layered PCBs. They are small holes that are drilled into the board to connect the different layers of a PCB. Buried vias differ from blind and through-hole vias because they are located between two inner layers of the PCB and do not penetrate through the surface of the board. This allows for the creation of more complex and compact board layouts, making them ideal for modern electronics with smaller form factors. Buried vias just like Blind Vias are used to route signals and power between layers while minimizing the number of layers needed, reducing the overall cost and size of the board.

Blind Vias and Buried Vias: The Differences

While both blind and buried vias serve the same purpose, they differ in how they are used and their construction. Let’s have a look at that:

Conclusion

In conclusion, both blind and buried vias are essential for high-density PCB designs. Blind vias are used to connect surface-mounted devices to inner layers of the board, while buried vias are used to create a more compact design and allow for more inner layer routing options. While blind vias are visible from one side of the board, buried vias are entirely hidden between the layers of the board. The choice between the two depends on the specific requirements of the design.

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Click here to learn more about Buried Vias.