What are the advantages and disadvantages of pcb multilayer board?

The biggest difference between PCB multilayer board and single and double panel is the addition of internal power layer and ground layer. The power and ground networks are routed mainly at the power layer. Each substrate layer on a PCB multilayer board has conductive metal on both sides, and special adhesives are used to connect the boards together, and insulation is present between each board. However, PCB multi-layer routing is mainly based on top and bottom layers, supplemented by intermediate wiring layers.

Therefore, the design method of multi-layer PCB board is basically the same as that of double panel. The key is how to optimize the wiring of the internal electrical layer to make the wiring of the circuit board more reasonable. The inevitable product of multi-function development, large capacity and small volume.

PCB multilayer board compared to PCB single panel, regardless of its intrinsic quality, through the surface, we can see the differences, these differences are crucial for the durability and functionality of the PCB throughout its life, the main advantage of pcb multi-layer board: this circuit board is anti-oxidation. Diversified structure, high-density, surface coating technology, to ensure the quality of the circuit board and safety, you can rest assured that use. The following are the important characteristics of high reliability multi-layer boards, which are the advantages and disadvantages of pcb multi-layer boards:

1. The copper thickness of the hole wall of the PCB multilayer board is 25 microns normally;

Benefits: Enhanced reliability, including improved Z-extension resistance.
Disadvantages: However, there are certain risks: problems with the electrical connectivity during the process of assembly (inner layer separation, hole wall rupture) or the possibility of failure under load conditions in the case of actual use. IPC Class2 (the standard of most factories) requires that PCB layers be coated with less than 20% copper.

2. No welding repair or open repair

Pros: Perfect circuit ensures reliability and safety, no maintenance, no risk.
Cons: PCB multi-layer boards are open if not serviced properly. Even if properly fixed, there may be a risk of failure under load conditions (vibration, etc.), which may lead to failure in practical use.

3. Exceed the cleanliness requirement of IPC specification

Advantages: Improving the cleanliness of PCB can improve reliability.
Risks: Residues on the wiring board, accumulation of solder poses a risk to the solder shield, ionic residues lead to a risk of corrosion and contamination of the soldered surface, which can lead to reliability issues (poor solder spot/electrical failure) and ultimately increase the probability of actual failure.

4. Strictly control the service life of each surface treatment

Advantages: Welding, reliability and reduced risk of moisture intrusion
Risks: Is the surface treatment of the old PCB multilayer board may lead to metallography changes, there may be solderability problems, while water intrusion may cause problems in the assembly process and/or the actual use of delamination, separation of inner and wall walls (open circuit), etc.

Whether in the manufacturing and assembly process or in actual use, PCB multi-layer board must have reliable performance, of course, this is related to the equipment and process technology level of PCB board factory.