Blind and Buried Vias PCB
Blind and buried vias PCBs, also known as HDI boards, are often used for mobile phones, GPS navigation and other high-end product applications. Conventional multilayer circuit board structure contains the internal line and external line, and then use drilling holes, and the hole metallization process to make layers of the line achieve the internal connection function.
With the development of electronic products, boards with high-density and high-precision require the corresponding circuits. The most effective way to improve PCB density is to reduce the number of vias, and put blind and buried vias precisely. To achieve this requirement, HDI boards came into being.
Buried vias are the through-holes in inner layers, whose upper and lower sides are all inside the board inside, which can not be seen after lamination can not see, thus they won’t take up the outer area.
Blind vias, in contrast to through-hole vias, are non-drilled vias. Simply speaking, the surface of blind via can only see one side, while the other side is in the board that can not be seen.
Usually, PCB boards used in mobile phone or navigation equipment are combined blind and buried vias, and such board requires high-tech and excellent accuracy. Thus, requirements for PCB machinery and equipment are much higher than those produced ordinary multilayer boards.