PCB Technical - What is PCB via design?

1.Vias are part of the printed circuit board(PCB) design. The function of vias is to electrically connect, fix and locate components. A via is composed of three parts: the hole, the pad area around the hole, and the POWER layer isolation area. Production of via holes: a layer of metal is plated on the cylindrical surface of the hole wall of the via hole to connect the copper foils of the middle layers. The upper and lower sides of the via hole are made into pads, and the lines are directly connected (or not connected).

2. Vias are generally divided into three categories: blind holes, buried holes and through holes. Blind holes-located on the top and bottom surfaces of the printed circuit board, have a certain depth (aperture and hole depth are in a certain ratio), and are used to connect the surface circuit and the inner circuit. Buried holes-connection holes in the inner layer of the circuit board (not visible on the surface of the circuit board). Through hole-through the entire circuit board, generally used for positioning and installation of components.

3. In the general PCB design, because the parasitic capacitance and parasitic inductance of the via have little effect on it, the via design of 1 to 4 layers of PCB usually chooses 0.36mm (aperture)/0.61mm (pad) /1.02mm (POWER isolation area) via. For signal wires with special requirements, such as power wires, ground wires, etc., through holes of 0.41mm/0.81mm/1.32mm are generally used.