The substrate of the multilayer circuit board factory is made of insulating and heat-insulating materials that are not easy to bend. The small circuit material that can be seen on the surface is copper foil. The copper foil was originally covered on the entire circuit board, but part of it was etched away during the manufacturing process, and the remaining part became a net-like small circuit. NS. Multilayer circuit board factories call these lines as wires or wiring, and they are used to provide circuit connections for parts on the circuit board.

Multilayer boards are now used on motherboards and graphics cards, greatly increasing the area that can be wired. The multi-layer circuit board factory uses more single or double-sided wiring boards, and puts an insulating layer between each layer and presses them together. The number of layers of a multi-layer circuit board means that there are several independent wiring layers. Usually, the number of layers is an even number and contains the two outermost layers. The common multi-layer circuit board generally has a structure of 4 to 8 layers. The number of layers designed by many multilayer circuit board factories can be seen by looking at the cut surface of the multilayer circuit board. But in fact, this method is not convenient.

The circuit connection of the multilayer circuit board factory is through buried via and blind via technology. Most motherboards and display cards use 4-layer multilayer circuit boards, and some use 6, 8 or even 10-layer multilayer circuit boards. If you want to see how many layers there are in the PCB, the multi-layer circuit board factory introduced that you can identify it by observing the via holes, because the 4-layer boards used on the motherboard and the graphics card are the first and fourth layers of wiring, and the other layers Another purpose (ground wire and power supply). Therefore, like double-layer boards, the pilot holes of the multilayer circuit board factory will penetrate through the multilayer circuit boards. If some guide holes appear on the front side of the PCB board but cannot be found on the back side, then it must be a 6/8-layer board. If the same via holes can be found on both sides of the multilayer circuit board, it will naturally be a 4-layer board.

The multi-layer circuit board factory will teach you a little trick: point the motherboard or display card to the light source. If the position of the guide hole can transmit light, it means that it is a 6/8-layer board; otherwise, it is a 4-layer board.