Double-sided circuit board, what is the hole ah
Through the hole of metal and non-metal hole, metal hole is like you said above, the hole is hollow, want to be solid to the PCB manufacturers to declare the hole hole. Through the hole is the default coating resistance, so feel like a solid. The difference between the multi-layer pad connection is not coated with solder and is also hollow.
The buried hole refers to the connection hole located in the inner layer of the printed circuit board and does not extend to the surface of the circuit board.
If the process from the process, these holes are generally divided into three categories, namely blind hole (blind via), buried (buried via) and through (through via). The blind holes are located on the top and bottom surfaces of the printed circuit board and have a depth for the connection of the surface lines and the underlying inner lines, which typically do not exceed a certain ratio (aperture).
Simply put, each hole on the PCB can be called a vias. From the point of view, the vias can be divided into two categories: one for the electrical connection between the layers; the second is used as a device fixed or positioning.
The basic concept of vias Throughholding is one of the important components of a multilayer PCB, which typically costs between 30% and 40% of PCB board costs.
