What Are The Characteristics Of Good Quality Pcb Boards?

The judgment of the quality of the pcb board is generally based on the appearance of the judgment, but depending on the experience, the quality of the pcb board is very important, so what are the characteristics of the good quality pcb board?

1. 25 micron hole wall copper thickness

Benefits: Enhanced reliability, including improved z-axis resistance to expansion.

The risk of not doing this are as follows:

Blowing or degassing, electrical connectivity problems during assembly (inner layer separation, hole wall fracture), or failure under load conditions in actual use. IPCClass2 (the standard used in most plants) requires 20% less copper plating.

2.No welding repair or open circuit repair

Benefits: Perfect circuit ensures reliability and safety, no maintenance, no risk

Risk of not doing so are as follows:

If it is not repaired properly, it will cause the board to open. Even if the repair is 'proper', there is a risk of failure under load conditions (vibration, etc.), which may cause malfunction in actual use.

3. Strictly control the service life of each surface treatment

Benefits: solderability, reliability, and reduced risk of moisture intrusion

Risk of not doing so are as follows:

Due to metallographic changes in the surface treatment of old boards, soldering problems may occur, and moisture intrusion may cause delamination, separation of inner layers and walls (opening) during assembly and/or actual use.

4. Cladding tolerance meets IPC4101 Class B/L requirements

Benefits: Strict control of the dielectric layer thickness can reduce the expected deviation of electrical performance.

Risk of not doing so are as follows:

Electrical performance may not meet the specified requirements, and the output/performance of the same batch of components will vary greatly.

5. Define the solder mask material to ensure compliance with IPC-SM-840 ClassT requirements

Benefits: “Excellent” inks for ink safety and ensuring solder mask inks meet UL standards.

Risk of not doing so are as follows:

Inferior inks can cause adhesion, flux resistance and hardness problems. All of these problems can cause the solder mask to detach from the board and eventually lead to corrosion of the copper circuit. Poor insulation properties can cause short circuits due to unexpected electrical connectivity/arc.

6. Define tolerances for shapes, holes and other mechanical features

Benefits: Strict control of tolerances can improve the dimensional quality of the product – improved fit, shape and function

Risk of not doing so are as follows:

Problems during assembly, such as alignment/mating (the problem of press-fitting the needle is only found when the assembly is complete). In addition, there is a problem in mounting the base due to an increase in dimensional deviation.

7, the thickness of the solder mask, although the IPC has no relevant regulations

Benefits: Improve electrical insulation properties, reduce the risk of flaking or loss of adhesion, and strengthen the ability to withstand mechanical impact – no matter where the mechanical impact occurs!

Risk of not doing so are as follows:

Thin solder masks can cause adhesion, flux resistance and hardness problems. All of these problems can cause the solder mask to detach from the board and eventually lead to corrosion of the copper circuit. Poor insulation properties due to the thin solder mask layer can cause short circuits due to accidental conduction/arc.