What specific measures need to be taken to produce high-reliability PCB circuit boards
Jul 18, 2022
It is critical that PCBs have reliable performance, both in the manufacturing assembly process and in actual use.
25 micron hole wall copper thickness
Benefits: Enhanced reliability, including improved z-axis expansion resistance.
Risks of not doing so: blow holes or outgassing, electrical connectivity issues during assembly (separation of inner layers, breakage of hole walls), or possible failure under load conditions in actual use.
2. No welding repair or open circuit repair
Benefit: Perfect circuit ensures reliability and safety, no maintenance, no risk.
Risk of not doing this: If repaired incorrectly, you will create an open circuit on the board.
3. Exceed the cleanliness requirements of IPC specifications
Benefit: Improved PCB cleanliness improves reliability.
Risk of not doing this: Residue, solder buildup on the board can present a risk to the solder mask which can lead to reliability issues (bad solder joints/electrical failure).
4. Strictly control the service life of each surface treatment
Benefits: Solderability, reliability, and reduced risk of moisture intrusion.
Risk of not doing this: Solderability issues may occur due to the surface treatment of older boards, resulting in delamination, separation of inner layers and hole walls (open circuit) during assembly and/or actual use.
5. The tolerance of CCL meets the requirements of IPC4101ClassB/L
Benefit: Strictly control the thickness of the dielectric layer and reduce the deviation from the expected value of the electrical performance.
Risk of not doing so: Electrical performance may not meet specified requirements, and components from the same batch may vary widely in output/performance.
6. Define solder mask materials to ensure compliance with IPC-SM-840ClassT requirements
Benefits: Achieves ink safety and ensures solder mask inks are UL compliant.
Risk of not doing so: Poor quality inks can cause adhesion, flux resistance and hardness problems.
7. Tolerances defining shapes, holes, and other mechanical features
Benefit: Tightly controlled tolerances improve the dimensional quality of the product – improving fit, form and function.
Risk of not doing this: There will be problems during assembly, such as alignment/mating.
8. NCAB specifies the thickness of the solder mask, although IPC has no relevant regulations
Benefits: Improved electrical insulation properties, reduced risk of spalling or loss of adhesion, increased resistance to mechanical shock.
Risk of not doing so: Thin solder mask can cause adhesion, flux resistance and hardness problems.
9. Defines appearance requirements and repair requirements, although IPC does not define them
BENEFITS: Safety is created with care and care in the manufacturing process.
Risks of not doing this: In addition to the problems that can be seen on the surface, what are the unseen risks, and the impact on the assembly, and the risks in actual use are difficult to predict.
10. Requirements for the depth of the plug hole
Benefit: High-quality plug holes will reduce the risk of failure during assembly.
Risk of not doing this: Chemical residues from immersion gold can remain in holes that are not fully plugged, causing problems such as solderability. And there may also be tin beads hidden in the holes, causing short circuits.
