All high-tech value-added electronic product designs in the fields of communications, computers, graphics and image processing are pursuing the characteristics of low power consumption, low electromagnetic radiation, high reliability, miniaturization, and light weight. In order to achieve the above goals, high-speed PCB design Among them, the via design is an important factor.
It consists of the hole, the pad area around the hole and the isolation area of the POWER layer, which are usually divided into three types: blind hole, buried hole and through hole. In the PCB design process, through the analysis of the parasitic capacitance and parasitic inductance of the vias, some precautions in the design of high-speed PCB vias are summarized.
High-speed PCB design vias are generally divided into three categories: blind vias, buried vias and through holes.
- 1) Blind holes, which are located on the top and bottom surfaces of the printed circuit board, have a certain depth and are used to connect the surface circuit and the inner circuit below. The depth of the hole and the diameter of the hole usually do not exceed a certain ratio.
- 2) Buried hole refers to the connection hole located in the inner layer of the printed circuit board, which does not extend to the surface of the circuit board. Both blind and buried holes are located in the inner layer of the circuit board, and are completed by a through-hole forming process before lamination, and several inner layers may be overlapped during the formation of the via.
- 3) Through holes, which pass through the entire circuit board and can be used for internal interconnection or as component mounting positioning holes. Since through holes are easier to implement in process and lower cost, generally printed circuit boards use through holes.