Via hole (VIA), the copper foil line between the conductive patterns in different layers of the circuit board is conducted or connected with this kind of hole, but the copper plated hole of the component pin or other reinforcement material cannot be inserted. A printed circuit board (PCB) is formed by stacking and accumulating many layers of copper foil. The copper foil layers cannot communicate with each other because each layer of copper foil is covered with an insulating layer, so they need to rely on vias for signal connection, so there are Chinese vias. title.
The through hole of the circuit board must pass through the plug hole to meet the customer's needs. In changing the traditional aluminum sheet plug hole process, the solder mask and plug hole of the circuit board surface are completed with a white mesh to make the production more stable and the quality more reliable. , it is more perfect to use. Via holes help circuits connect and conduct with each other. With the rapid development of the electronics industry, higher requirements are placed on the manufacturing process and surface mount technology of printed circuit boards (PCBs).
The via hole plugging process came into being, and the following requirements must also be met:
1. There only needs to be copper in the hole, and the solder mask can be plugged or not;
2. There must be tin-lead in the hole, and there is a certain thickness requirement (4um), to avoid solder mask ink entering the hole, causing tin beads to be hidden in the hole;
3. The via holes must have solder resist ink plug holes, which are opaque, and must not have rings and silver beads. Must be flat and so on.
Blind holes are the connection between the outermost circuit in the printed circuit board (PCE) and the adjacent inner layer with plated holes. Because they cannot see the opposite side, they are called blind holes. In order to increase the space utilization between board circuit layers, blind holes come in handy. A blind hole is a via hole to the surface of the printed board
Blind holes are located on the top and bottom surfaces of the circuit board and have a certain depth. They are used to connect the surface circuit to the inner circuit below. The depth of the hole generally has a specified ratio (aperture). This production method requires special attention, and the depth of the drilling must be good. If you do not pay attention, it will cause difficulties in electroplating in the hole. Therefore, few factories will adopt this production method. In fact, it is also possible to drill holes for the circuit layers that need to be connected in advance, and then glue them together at the end, but more precise positioning and alignment devices are required.
A buried hole is a connection between any circuit layers inside a printed circuit board (PCB), but it is not connected to the outer layer, that is, there is no via hole extending to the surface of the circuit board.
This manufacturing process cannot be achieved by bonding the circuit boards and then drilling holes. It is necessary to perform drilling operations on individual circuit layers. First, the inner layers are partially bonded and then electroplated, and finally all of them are bonded. Since the operation process is more laborious than the original vias and blind holes, the price is also the most expensive. This fabrication process is usually only used for high-density circuit boards. Increase the space utilization of other circuit layers.
Drilling is very important in the printed circuit board (PCB) production process. The simple understanding of drilling is to drill the required vias on the copper clad laminate, which has the function of providing electrical connections and fixing devices. If the operation is not correct, there will be problems in the via hole process, and the device cannot be fixed on the circuit board, which will affect the use of the circuit board at least, or make the whole board scrapped, so the drilling process is very important.
