HDI circuit board is simply made of multilayer circuit board by product layer method and micro-blind hole technology.That is to say, according to the traditional practice to get (no) electroplating through hole (PTH) core plate, and then on the two sides of the outer layer of fine line and microblind hole layer of the multi-layer plate. Definition of microblind holes Microholes usually refer to holes of 150um (6mil) in diameter in the PBC industry.General mechanical drilling holes cannot be completed. Definition of buried holes Buried hole (Buried hole), refers to the hole buried in the inner layer, generally the finished product can not see.The advantage of the buried hole is that it does not occupy the surface area of the PCB, so that more components can be placed on the PCB surface.The buried holes are generally mechanical holes with a diameter of over 0.2mm. Definition of blind holes Blind hole (Blind hole), the blind hole can be seen in the finished product, and the difference from the through hole is that the two sides of the through hole can be reached, and the blind hole can only be seen on one side.Compared with the through hole, the blind hole has the advantage that it can be wired below the corresponding position of the blind hole.Generally, mechanical blind hole is completed by mechanical drill control depth, and laser blind hole is obtained by laser.
