Maintenance of PCB and identification of multilayer PCB layers

Maintenance of PCB and identification of multilayer PCB layers

PCB manufacturers, PCB designers and PCBA manufacturers explain PCB maintenance and how to identify the layers of multilayer PCB

It is believed that many customers of PCB manufacturers will have such problems. How should PCB be maintained? How to make the life of the circuit board longer? Now let the circuit board manufacturer analyze the maintenance of PCB for you.

PCB circuit board uses the method of printing etching inhibitor to make circuit lines and drawings. According to the number of circuit layers, the circuit board factory can be divided into single-sided pcb board, double-sided pcb board and multi-layer pcb board. The common multilayer board is generally 4-layer board or 6-layer board, and the complex multilayer board can reach more than ten layers.

There are both high-speed logic circuits and linear circuits on the circuit board, so they should be separated as far as possible, and the ground wires of the two should not be mixed, and they should be connected to the ground wire of the power supply terminal respectively. The grounding area of linear circuit shall be increased as much as possible. How should PCB be maintained?

1、 Half year maintenance:

Observe whether the electronic components in the circuit produced by the circuit board factory have gone through the traces of high temperature, and whether the electrolytic capacitor bulges and leaks, if any, replace it.

Clean the dust on the PCB circuit board every quarter with special cleaning solution for PCB circuit board. After cleaning the dust on the PCB circuit board, dry the PCB circuit board with a hair dryer.

2、 Annual maintenance:

1. Clean the dust on the PCB.

2. Conduct spot check on the capacity of electrolytic capacitors in PCB circuit board. If it is found that the capacity of electrolytic capacitors is less than 20% of the nominal capacity, they should be replaced. Generally, the service life of electrolytic capacitors should be replaced after about ten years to ensure the working performance of PCB circuit board.

3. For high-power components coated with heat dissipating silicone grease, check whether the heat dissipating silicone grease is dry and solid. For dry and solid components, remove the dry and solid heat dissipating silicone grease and apply new heat dissipating silicone grease to prevent the high-power components in PCB from burning out due to poor heat dissipation.

How to Quickly Identify the Number of Layers of Multilayer PCB

Now the main board of PCB board and the video card both use multi-layer circuit board, which greatly increases the area that can be wired, and quickly separate the number of layers of the main board circuit board! Now let's get to know.

The circuit connection of multilayer circuit boards is through the buried hole and blind hole technology. The motherboard and display card mostly use 4-layer PCB, while some use 6-layer, 8-layer PCB, or even 10 layer PCB.

To see how many layers a PCB has, you can identify them by observing the pilot hole, because the 4-layer circuit boards used on the motherboard and display card are routed at the 1st and 4th layers, and the other layers are used for other purposes (ground wire and power supply).

Therefore, like the double-sided circuit board, the pilot hole will pierce the PCB. If some pilot holes appear on the front of the PCB, but cannot be found on the back, it must be 6/8 layers. If the same pilot holes can be found on both sides of a PCB, it is a 4-layer PCB.

Tip: Clamp the main board or display of the PCB to the light source. If the position of the guide hole can transmit light, it means that it is a 6/8 layer circuit board; On the contrary, it is a 4-layer circuit board.

PCB manufacturers, PCB designers and PCBA manufacturers will explain PCB maintenance and how to identify the layers of multilayer PCB.