How to judge the reliability of PCB, 14 important features tell you!

PCBS are almost identical on the outside, regardless of their inner quality. It is beneath the surface that we see the differences that are critical to the durability and function of PCBS throughouttheir life.

Whether in the manufacturing and assembly process or in actual use, PCB to

have reliable performance, this is very important. In addition to the associated costs, defects in the assembly process may be carried by the PCB into the final product, which may break down during actual use, leading to claims. Therefore, from this point of view, it is safe to say that the cost of a good quality PCB is negligible.

In all market segments, especially those producing products in critical application areas, the consequences of such failures are dire.

These aspects should be kept in mind when comparing PCB prices. Although reliable, guaranteed and long-life products have higher initial costs, they are worth it in the long run.

Here are 14 of the most important characteristics of a highly reliable circuit board:

1, 25 micron hole wall copper thickness

benefit

Enhanced reliability, including improved Z-axis expansion resistance.

The risk of not doing so

Problems with hole blowing or degassing, electrical connectivity during assembly (inner separation, hole wall breakage), or possible failure under load conditions in actual use. IPCClass2(the standard adopted by most factories) requires 20% less copper plating.

2. No welding repair or line repair

benefit

Perfect circuits ensure reliability and safety, no maintenance, no risk

The risk of not doing so

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

3. Exceed the cleanliness requirements of IPC specifications

benefit

Improving PCB cleanliness improves reliability.

The risk of not doing so

Residue and solder buildup on the circuit board pose a risk to the solder shield. Ionic residue poses a risk of corrosion and contamination of the weld surface, which can lead to reliability problems (poor solder joints/electrical failures) and ultimately increase the probability of actual failure.

4, strictly control the service life of each kind of surface treatment

benefit

Solderability, reliability, and reduced risk of moisture intrusion

The risk of not doing so

Solderability problems can occur due to metallography changes in the surface treatment of older boards, while moisture intrusion can lead to delamination, inner layer and hole wall separation (break) during assembly and/or actual use.

5. Use internationally known substrates -- no "local" or unknown brands

benefit

Improve reliability and known performance

The risk of not doing so

Poor mechanical properties mean that the board will not perform as expected under assembled conditions. For example, high expansion properties can lead to delamination, circuit breaking and warping problems. Weakening of electrical characteristics can result in poor impedance performance.

6. Copper clad plate tolerance meets the requirements of IPC4101ClassB/L

benefit

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

The risk of not doing so

Electrical performance may not meet the specified requirements, the same batch of components in the output/performance will be very different.

7. Define solder resistance materials to ensure compliance with IPC-SM-840ClassT requirements

benefit

Prinplin recognizes "excellent" inks for ink safety, ensuring that the solder resistance layer inks meet UL standards.

The risk of not doing so

Poor quality ink can lead to adhesion, flux resistance and hardness problems. All of these problems can cause the solder shield to detach from the circuit board and eventually lead to corrosion of the copper circuit. Poor insulation characteristics can cause short circuits due to unexpected electrical connectivity/arcing.

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

benefit

Strict tolerance control can improve the dimensional quality of the product - improve fit, shape and function

The risk of not doing so

Problems during assembly, such as alignment/fit (pin pressing issues only become apparent when assembly is complete). In addition, loading the base can be problematic due to the increased size deviation.

9. Prinplin has specified the thickness of the solder shield, although IPC has no relevant regulations

benefit

Improved electrical insulation to reduce the risk of flaking or loss of adhesion and to increase resistance to mechanical impact wherever it occurs!

The risk of not doing so

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

10. Appearance requirements and repair requirements are defined, although IPC does not

benefit

In the manufacturing process of careful care and careful casting safety.

The risk of not doing so

Multiple scrapes, minor injuries, repairs, and repairs - boards work but don't look good. In addition to the visible problems, what are the hidden risks, the impact on assembly, and the risks in actual use?

11. Requirements for the depth of the plug hole

benefit

High quality plugs will reduce the risk of failure during assembly.

The risk of not doing so

The chemical residue in the gold settling process can be left in the hole where the plug hole is not sufficient, causing problems such as weldability. Moreover, tin beads may be hidden in the hole, which may splash out during assembly or actual use, causing a short circuit.

12. PetersSD2955 specifies the brand and model of peelable blue glue

benefit

The designation of peelable blue glue avoids the use of "local" or cheap brands.

The risk of not doing so

Poor quality or cheap peelable glue may bubble, melt, crack, or set like concrete during assembly, making the peelable glue unpeeled/ineffective.

13. Prinplin performs specific approval and placing procedures for each purchase order

benefit

This procedure is performed to ensure that all specifications have been confirmed.

The risk of not doing so

If product specifications are not carefully confirmed, the resulting deviations may not be discovered until assembly or the final product, when it is too late.

14. Sleeve plate with scrap unit is not accepted

benefit

Not using partial assembly can help customers improve efficiency.

The risk of not doing so

Defective sheeting requires special assembly procedures. If the end-of-life unit board (x-out) is not clearly marked, or it is not isolated from the sheeting, the known defective board may be assembled, wasting parts and time.