PCB board industry from the 20th century to the beginning of the 21st century, PCB board electronic industry in technology by leaps and bounds, electronic assembly technology has been rapidly improved.As printed PCB board industry, only with its synchronous development, can continue to meet the needs of customers.Along with the small, light and thin volume of electronic products, printed PCB board has developed flexible board, rigid flexible board, embedded/blind hole multilayer board and so on.
When it comes to blind/buried holes, let's start with the traditional laminate.The standard multilayer PCB structure is composed of inner and outer layers, which are then drilled and metallized to achieve the interconnecting function of the layers.But because of the increase in line density, the packaging of parts is constantly updated.In order to make the limited area of PCB board fit more parts with higher performance, in addition to the thinner line width, the aperture is also reduced from 1mm of DIP jack aperture to 0.6mm of SMD, and further reduced to less than 0.4mm.However, it will still occupy the surface area, so there are buried holes and blind holes. The definition of buried holes and blind holes is as follows:
A. Buried Via
The through hole between the inner layer is not visible after pressing, so it does not need to occupy the area of the outer layer. The upper and lower sides of the hole are in the inner layer of the PCB board. In other words, it is buried inside the PCB board.
B. Blind Via
To connect the surface layer with one or more inner layers, one side of the hole is on one side of the PCB board, and then the hole is connected to the inside of the PCB board.
Through the introduction of the above I believe that we must have a more in-depth understanding of the blind buried orifice.