PCB News - How to identify the number of layers of the motherboard PCB circuit board

How to identify the number of layers of the motherboard PCB circuit board

The substrate of the PCB circuit board itself 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 PCB board, but part of it was etched away during the manufacturing process, and the remaining part became a network of small circuits NS. These lines are called wires or wiring, and are used to provide circuit connections for parts on the PCB circuit board.

Usually the color of PCB circuit board is green or brown, which is the color of solder mask. It is an insulating protective layer that can protect the copper wire and prevent parts from being welded to the wrong place. Multilayer boards are now used on motherboards and graphics cards, greatly increasing the area that can be wired.

1.Multi-layer circuit boards use more single or double-sided wiring boards, and put a layer of insulating layer between each layer of boards and press them together.

2. The number of layers of the PCB circuit board means that there are several independent wiring layers. Usually the number of layers is even and contains the outermost two layers. Common PCB circuit boards are generally 4 to 8 layers of structure. The number of layers of many PCB boards can be seen by looking at the cut surface of the PCB circuit board. But in fact, no one can have such good eyesight. Therefore, Yuwei Electronics will teach you some more methods below.

3. The circuit connection of multi-layer circuit boards is through buried via and blind via technology. Most motherboards and display cards use 4-layer PCB circuit boards, and some use 6, 8 or even 10-layer PCB boards.

4. If you want to see how many layers the PCB circuit board has, you can identify it by observing the guide holes, because the 4-layer board used on the motherboard and the display card is the first and fourth layers of wiring, and the other layers are otherwise. Purpose (ground wire and power supply). Therefore, like the double-layer board, the via hole will penetrate the PCB circuit board.

5. If some vias appear on the front of the PCB but cannot be found on the back, then it must be a 6/8-layer board. If the same via holes can be found on both sides of the PCB, it will naturally be a 4-layer board.

Tips: 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.