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Introduction to via types- buried and blind vias and through-hole and microvias


A multilayer PCB connects its layers via a cross. Multiple layers of the board can be linked together to minimize the size of the PCB since the layers can be stacked. Each Via of the circuit board is covered with copper pieces, and a hole is drilled through them to provide an aperture.

 By using copper cavities in drilled holes or electroplating, holes can be made conductive.The PCB’s layers are connected by a conductive plating on the chamber’s outside, while the interior of the Via is often filled with a non-conductive material.

What is blind via?

Without travelling the length of the board, a blind via links internal and exterior board layers. Without connecting to the external levels, a buried via joins internal layers. All of the strata are connected via a through opening through as well.

What is buried via?

A via that can’t be seen from the outer layers and that is positioned between at least two inner levels is said to be buried. With this advancement, a board’s functionality can be increased while taking up less space (pressing thickness). A layer develop cross-over of buried and blind vias is discouraged due to financial reasons!

What is stacked via and microvia?

Stacked Via
Electroplated copper is injected into stacked vias to link thick layers. Stacking vias are used to minimize subsequent overlay produced by another blind via starting on the same layer as the first buried and blind vias closes if a basic buried and blind vias has a perspective ratio larger than 1:1.

Flags were first routed across neighboring board layers using microvias since the via apertures were too tiny to even consider utilizing a bore. Taking everything into consideration, a laser creates these vias in a single layer of a PCB while the board is built using sequential development (SBU). The whole bundle size, including processor electrical associations, may be reduced by a factor of five by using two-layered network showcase affiliations with the underside of devices thanks to Microvias.


What are the types of PCB vias?

Blind and buried vias are two different types of vias that depend on where they are located on the PCB layers.

On a printed circuit board, there are three types of vias other than blind and buried vias:


All PCB layers as well as the printed circuit boards two exterior surfaces are traversed by Through-Hole Vias. Through via have more features then other vias as they are more strong and less damaging the system


The design technique known as “via-in-Pad” involves embedding a via in a component’s copper arrival cushion. Cushion directing, as opposed to conventional PCB via directing, enables a design to employ more conservative part pitch measurements and reduce the overall PCB size.


High-density interconnect (HDI) substrates and printed circuit sheets use microvias as interconnects across layers to manage the thick information-yield (I/O) bundles of modern electronics. The hardware industry aims to provide cost-effective, lightweight, durable products with increased usefulness due to transportability and remote interchanges.

Importance of vias when designing a PCB

An electrical connection between several printed circuit board layers is referred to as a “via” (or “Blind and buried vias”). A via is simply a very small hole that has been bored through the PCB overlays and connects at least two adjacent layers. 

By creating an electrical connection in the covering that serves as protection between the PCB layers, the aperture is sealed on the inside with copper via galvanic cycling, riveting, or inserting a tiny container of conductive material. Vias link follows, cushions, and polygons on different levels of a PCB.  Copper chambers called vias are framed or inserted into holes in a printed circuit board (PCB).

How to make a via in PCB?

The PCB makers drills a hole in the PCB at the intersection of at least two leads to create a via. The opening then experiences an electroplating contact to become into conductible. The most typical via representation, also known as blind and buried vias, links each layer between the top and bottom of the PCB.

The difference among blind and buried vias, and through-holes

The following illustrates how through-openings, blind and buried vias differ from one another. The board’s outer and inner layers are connected by a blind via, which does not span the whole board. The outer layers are not touched by a hidden path that connects the inside layers. Additionally, a through opening through joins the strata from top to bottom.


What is non-through via technology?

Simple highlights that are processed through or punched through your circuit board but do not get conductive copper plating are known as non-plated through vias. When making mounting holes for your board, NPTH highlights are frequently utilized to provide passages for screws or other latches.

How to design via in high-speed PCB?

Like signs, vias add capacitance and inductance to the circuit. In signals with lower frequency, these features are often irrelevant. Fast followers can lose signal reliability and modify their impedance when vias are added, though. Vias should ideally not be used with high-speed communications. Fast PCB configuration, to put it simply, is any design in which the real qualities of your circuit board, such as your design, bundling, layer stack-up, and interconnections, have an impact on the integrity of your signs.

The difference between via type and via diameter

A via’s outward dimensions are what determine its size. Look at the board in the 3Dviewer and turn off the board and some of the outer layers, such the weld cover, to investigate and have a closer look at everything. The via drill width is used to measure the via externally.

Vias come in three different varieties: through vias, blind and buried vias.
●Blind vias are these link a surface layer to a deeper one.
●Combine two inner layers if there are buried vias.
●Vias are used to join two outer layers is through vias

How to make PCB with blind and buried vias?

By using depth-controlled laser, we do not create blind and buried vias. The plates are drilled at least one centre before being embedded. The stack is created and compacted after that. It is possible to use this technique several times.

This suggests:

1. For a through to pass through, there must always be a significant amount of copper layers.
2. The upper side of a centre cannot be the end of a via.
3. A Via cannot initiate from a center’s base side.
4. Blind or buried vias cannot start, finish, or meet another such via unless they are completely incorporated inside of one another.


Several vias, including blind and buried vias, are available for PCB design, as was mentioned throughout the debate. For cutting-edge scaled-down sheets in machines with few components, blind and buried vias are perfect. PCB vias are important, particularly in various circuit sheets. Without vias, it will be very challenging to build strong, well-layered sheets. 

It is crucial to have a team of experts that can assess your needs for care and treatment to minimize negative consequences. For more information about our circuit board goods and services, get in touch with us right now.



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