Blind Vias and Buried Vias

Buried Vias:

Connects two adjacent inner copper layers. They are not visible from the surface and so are 'buried'.

Advantages and disadvantages

Using blind and buried vias in a PCB design has its advantages and disadvantages. The advantage, of course is that this technology offers a viable design technique to help meet the density constraints of lines and pads on a typical design without increasing the layer count or board size. The disadvantage of the technology is that due to the additional operations in manufacturing the board, the cost of a board using blind and/or buried vias is significantly higher than a typical multilayer_ board with the same number of layers.