What is through hole technology used for?
Via (VIA), this is a common hole used to conduct or connect copper foil lines between conductive patterns in different layers of the buile-up printed board. For example (such as BVH（buried/blind via hole）PCB), but can not insert Electronic components leads or copper-plated holes of other reinforced materials. Because the PCB is formed by the accumulation of many copper foil layers, each layer of copper foil will be covered with an insulating layer, so that the copper foil layers cannot communicate with each other, and the signal link depends on the via hole. (Via), so there is the title of Chinese via.
The characteristic is: in order to meet the needs of customers, the through holes of themulit-wiring printed board must be filled with holes. In this way, in the process of changing the traditional aluminum plug hole process, white mesh is used to complete the solder mask and plug holes on the circuit board to make the production stable. The quality is reliable and the application is more perfect. Vias mainly play the role of interconnection and conduction of circuits. With the rapid development of the electronics PCB Assembly products industry, higher requirements are also placed on the process and Surface-Mount (SMT) &BGA Assembly technology of printed circuit boards. The process of plugging the via hole is applied, and the following requirements should be met at the same time: 1. There is copper in the via hole, and the solder mask can be plugged or not. 2. There must be tin and lead in the through hole, and there must be a certain thickness requirement (4um) that no solder mask ink can enter the hole, resulting in hidden tin beads in the hole. 3. The through holes must have solder mask ink plug holes, opaque, and must not have tin rings, tin beads, and flatness requirements.
