At first glance, PCB boards have the similar surface even with different inner quality. However, just through the small difference in surface we can discuss the quality difference which are critical to the durability and functionality of the PCB lifetime.
Whether it is in the PCB manufacturing and assembly process or in practice using, PCB must have a reliable performance, it is essential. In addition to the relative costs, defected PCB in the assembly process may be brought into the final product, which may result in failure in actual use, resulting in claims. Therefore, from this point of view, we can totally say that the cost of a high-quality PCB is negligible. In all market segments, particularly for those critical applications, the consequences of such failures are unthinkable.
These aspects should be kept in mind when comparing PCB prices. While reliable, assured and long-life products have higher initial costs, they are good value for money in the long run ways to lose weight quickly. Let’s take a look at the 14 most important features of a high-reliability PCB board:
1. The copper wall thickness is 1,25μm
Benefits:
Enhanced reliability, including improved z-axis resistance to expansion.
Risk of not doing so:
Blowhole or degassing, electrical connectivity problems during PCB assembly (internal separation, fracture of the wall), or failure under load conditions in actual use. IPCClass2 (the standard used in most factories) requires less than 20% less copper.
2. Assembly repair or open circuit repair
Benefits:
The perfect circuit ensures reliability and safety, no maintenance, no risk
Risk of not doing so
If not properly fixed, it will cause the open circuit. Even if the repair is ‘right’, there is a risk of failure under load conditions (vibration, etc.), which may cause a malfunction in actual use.
3. Satisfy the IPC specification cleanliness requirements
Benefits
Improve PCB cleanliness can improve reliability.
Risk of not doing so
Residue on the circuit board, solder buildup can pose a risk to the solder mask, which can lead to corrosion and contamination of the solder surface, which can lead to reliability problems (bad solder joints / electrical faults) and eventually to actual failures Probability.
4. strictly control the life of each surface treatment
Benefits
Solder ability, reliability, and reduce the risk of moisture invasion
Risk of not doing so
The problem of solder ability may occur due to metallographic changes in the surface treatment of the old circuit boards, and moisture intrusion may cause problems such as delamination, separation of inner and outer walls (disconnection) during assembly and / or actual use.
5. Using the internationally renowned substrate – do not use “local” or unknown brand
Benefits
Improve reliability and known performance
Risk of not doing so
Poor mechanical properties mean that the board cannot perform as expected under the circuit board assembly conditions. For example, higher expansion performance can result in delamination, breakage, and warping problems. A reduction in electrical characteristics may result in poor impedance performance.
6, CCL tolerance in line with IPC4101ClassB / L requirements
Benefits
Strict control of the thickness of the dielectric layer can reduce the expected deviation of electrical performance.
Risk of not doing so
Electrical performance may not meet the requirements, the same batch of components in the output / performance will be quite different.
7, the definition of solder materials, to ensure compliance with IPC-SM-840ClassT requirements
Benefits
The NCAB Group recognizes “good” inks to achieve ink safety and ensures that solder resist ink meets UL standards.
Risk of not doing so
Poor inks can lead to adhesion, flux resistance and hardness issues. All of these problems can lead to the solder mask layer from the circuit board, and eventually lead to corrosion of copper circuit. Poor insulation properties can be short-circuited by accidental electrical continuity / arc.
8, to define the shape, hole and other mechanical characteristics of the tolerance
Benefits
Strict control of tolerance can improve the quality of the product size – improved coordination, shape and function
Risk of not doing so
Problems during assembly, such as alignment / mating (problems with press fit are only found when assembly is complete). In addition, due to increased size deviation, there will be problems with loading the base.
9, NCAB specifies the thickness of the solder mask, although the IPC is not the relevant provisions
Benefits
Improved electrical insulation properties, reduced risk of peeling or loss of adhesion, and enhanced resistance to mechanical impact – regardless of where the mechanical impact occurs!
Risk of not doing so
Thin solder mask layer can lead to adhesion, flux resistance and hardness issues. All of these problems can lead to the solder mask layer from the circuit board, and eventually lead to corrosion of copper circuit. Due to the thin solder-resist layer, the insulation properties are poor and the short circuit can be caused by accidental on / arc.
10, defining the appearance requirements and repair requirements, although IPC is not defined
Benefits
In the manufacturing process carefully care and careful casting carefully.
Risk of not doing so
A variety of abrasions, minor damage, repair and repair – circuit boards can be used but not good-looking. In addition to the surface can see the problem, there are what can not see the risk, as well as the impact of the assembly, and in actual use of the risk?
11, the depth of the filled vias requirements
Benefits
High quality filled vias reduce the risk of failure during assembly.
Risk of not doing so
Not enough filled vias in the process of residual gold immersion in the chemical residue, resulting in solder ability and other issues. There may also be the tin hidden in the holes, in the assembly or actual use, tin beads may splash out, resulting in short circuit.
12, PetersSD2955 designated branded and special models peelable mask
Benefits
The designation of peelable mask avoids the use of “local” or cheap brands.
Risk of not doing so
Poor or inexpensive peelable mask may foam, melt, rupture or solidify as concrete during assembly, so that the peelable adhesive does not come off / function.
13, NCAB for each purchase order for the implementation of specific recognition and order procedures
Benefits
The execution of the program ensures that all specifications have been confirmed.
Risk of not doing so
If the product specifications are not carefully confirmed, the resulting deviation may be to the assembly or the final product only to be found, but then too late.
14, do not accept the x-outs on the panel
Benefits
Not using local assembly can help customers improve efficiency.
Risk of not doing so
A defective panel PCB requires a special assembly procedure. If it is not clearly marked (x-out) or is not isolated from the plate, it is possible to assemble this known bad board, Waste parts and time.
