How to control the quality of pcb

Printed circuit boards are an integral part of electronic devices and are the core component that controls the entire device. pcb is used in a variety of applications including consumer electronics, automotive, aerospace, communications, medical devices and other industries.

Quality is the lifeblood of a product. pcb quality control processes, including visual inspection, functional testing and environmental testing. These processes are critical to detecting defects and ensuring that PCB assemblies function correctly and reliably.

In this article we will focus on the pcb component process, such as any control pcba quality, and emphasize the importance of quality control for the product. The details are as follows:

Basic Principles of Quality Control

IPC Standards
The IPC (Institute of Printed Circuits) sets industry standards for PCB design, assembly, and testing. IPC standards help businesses to maintain consistency and reliability in the final product.

Production Process Control
Production process control involves monitoring and controlling the entire production process to prevent defects and ensure consistency in the final product. This includes maintaining the temperature, humidity, and other environmental factors that may affect the quality of the final product.

Testing and Inspection
Testing and inspection are critical aspects of PCB assembly quality control. They involve using various methods such as automated optical inspection (AOI), X-ray inspection, and functional testing to detect and correct any issues that may arise during the assembly process.

PCB assembly quality control is a vital process that ensures that the final product meets the required performance standards and reliability. By implementing basic principles of quality control such as IPC standards, production process control, testing, and inspection, businesses can prevent defects and ensure consistency in the final product.

The importance of PCB quality control

The importance of PCB quality control is mainly reflected in the following aspects:

1. Ensure product performance: PCB is the core component of electronic equipment, its quality directly affects the performance of the entire product. Through strict quality control, you can ensure the quality of PCB manufacturing process, materials, layers, layout and wiring and other aspects of the quality, so as to ensure stable and reliable product performance.

2. Improve production efficiency: In the PCB production process, if there is a quality problem, it may lead to low production efficiency, or even need to rework or rework. Through quality control, we can find and solve the problem in time, avoid waste and delay in the production process, and improve production efficiency.

3. Reduce costs: PCB quality problems may lead to product damage, return or repair, etc., which will increase the cost of the enterprise. Through quality control, we can reduce the occurrence of these problems, thus reducing the cost of the enterprise.

4. Enhance corporate image: a strict quality control system can enhance the image and reputation of the enterprise, so that customers more trust and recognition of the enterprise’s products and services.

How to control the quality of pcb

First, the design stage: optimize PCB layout and circuitry

In order to improve the performance and quality of the PCB board, the design phase is crucial. Designers need to give full consideration to circuit layout, component selection and thermal management. In circuit design, factors such as electrical performance, signal integrity and electromagnetic compatibility should be given full attention. At the same time, the use of PCB design software, such as Altium Designer, Eagle, etc., can effectively reduce design errors, optimize the layout and improve design efficiency.


Second, the choice of materials: the selection of high-quality substrates and copper foils

The performance and quality of the PCB board depends largely on the materials used. In the manufacturing process, the selection of high-quality substrates and copper foil is critical. High-quality base materials can ensure the thermal performance and mechanical strength of the PCB, thus improving the reliability of the product. In addition, the selection of high-purity copper foil can improve conductivity, reduce resistance and improve circuit performance.


Third, the production process: strict control of process parameters

PCB production process process parameters to ensure the quality and performance of the PCB board is critical. These parameters include: copper sinking, etching, drilling, plating, screen printing, hot air leveling, etc.. Through strict control of these parameters, you can ensure that the size of the PCB board, line width, aperture, etc. to meet the design requirements, improve product reliability and performance.


Fourth, detection and testing: to ensure that products meet quality standards

For PCB board manufacturers, comprehensive inspection and testing of PCB boards produced is the key to ensure quality and performance. This includes visual inspection, automatic optical inspection (AOI), X-ray inspection, electrical testing and so on. Through these inspection and testing methods, problems in the production process can be effectively identified and eliminated to ensure that the product meets the design and quality standards.


Fifth. Quality management system: continuous terminal quality control and continuous improvement

To ensure the quality and performance of PCB boards, manufacturers should establish a comprehensive quality management system. Through the implementation of ISO 9001, ISO 14001, IATF 16949 and other international quality certification, not only to ensure that the company’s production processes and quality control system in line with international standards, but also to continuously improve and optimize the production process to improve product quality and performance. At the same time, regular training of employees to improve their skills and quality awareness is an important part of ensuring the quality and performance of PCB boards.


Sixth, environmental considerations: the implementation of green production strategy

In order to ensure the quality and performance of PCB boards at the same time, manufacturers should also pay attention to environmental protection, the implementation of green production strategies. This includes optimizing the production process, reduce waste and emissions of hazardous substances, the use of environmentally friendly materials, as well as the promotion of lead-free and halogen-free technologies. By implementing green production strategies, manufacturers can improve the environmental performance of their products while enhancing their corporate image and competitiveness.

Nine major quality problems and solutions of the PCB board

n the entire production process of the PCB circuit board, there are many quality control points. If it is not rigorous, the quality problem of the PCB line board is endless. This is also a headache, because there is only one of them, so big, so big, so big Most devices are not available. Next, introduce the 9 major quality problems and solutions of the PCB board.

1. [Layers]

Stratification is the difficulty of the boss of PCB, ranking first in common problems. The cause of it may be roughly as follows:
(1) Improper packaging or preservation, moisture;
(2) The preservation time is too long, exceeding the preservation period, and the PCB board is tide;
(3) Supplier’s materials or process issues;
(4) Design materials and copper surfaces are not well distributed.


2. [Poor weld]
Weldability is also one of the more serious issues, especially batch problems. The possible cause is plate surface pollution, oxidation, black nickel, nickel thick abnormalities, anti -welding SCUM (shadow), too long storage time, moisture absorption, PAD on the anti -welding, too thick (repair). The pollution and hygroscopic problems are relatively easy to solve, and other problems are more troublesome, and there is no way to find it through feeding inspection. At this time, it is necessary to pay attention to the process capacity and quality control plan of the PCB board factory. For anti -welding PAD and poor repairs, you need to understand the standards of PCB suppliers on the formulation of maintenance. Inspectors and inspectors have a good assessment system, and at the same time, it is clear that the dense area of the pads cannot be repaired.


3. [Board bending plates]
The reasons that may cause the plate bending plates are: supplier selection problems, abnormal production processes, poor control of heavy labor, improper transportation or storage, not strong enough design of the broken hole, and the differences in copper area of each layer are too large. In the last 2 points, the design of the design needs to be avoided in the early stage. At the same time, the PCB factory simulation stickers IR conditions can be required to test, so as not to occur in the back of the furnace. For some thin plates, you can need to add a wooden slurry plate to the packets when the packaging is used to avoid subsequent deformation. At the same time, add a fixture to prevent the device from overweighting the curved plate.


4, [scrape, dew copper]
Scratches and bronze are the defects that test the management system and execution of the PCB plant. This problem is not serious, but it will indeed bring quality concerns. Many PCB companies will say that this problem is difficult to improve. The author once promoted the improvement of scratches of many PCB factories, and found that many times it is not that it is not good, but whether to change it or not to change it. All PCB factories that seriously promote the project have improved significantly.


5. [Poor impedance]
Impedance is an important indicator of the radio frequency performance of the mobile phone board. Generally, the common problem is that the impedance differences between the PCB batches are relatively large. Since the current impedance test bar is generally on the side of the PCB, it will not ship with the board, so the supplier can pay the batch of impedance strips and test reports for each time they ship. Comparison data of the edge line diameter and the inner line diameter.


6. [BGA welding empty hole]
BGA welded cavities may cause poor main chip function, and may not be found in the test that hidden risks are high. So many patch factories now have X-Ray for inspection after the part. The cause of this kind of bad may occur is the residual liquid or impurities in the PCB hole, vaporization after high temperature, or poor laser hole type on the BGA pad. Therefore, many HDI boards now require electroplating pores or half -filled holes to avoid this problem.


7. [Foam/Show off for anti -welding]
Such problems are usually abnormal in the control of the PCB welding process, or the use of anti -welding ink is not suitable (cheap goods, non -chemical inks, not suitable for installing welded welds), or may be too high in patch and heavy work. To prevent batch problems, PCB suppliers need to formulate corresponding reliability test requirements and control them at different stages.


8. 【Poor Confucius】
Poor holes are mainly caused by insufficient technical capabilities of the PCB plant or simplified technology. Its manifestations are not full of plug holes. It may cause insufficient welding volume, short circuit with patch or assembly devices, and residual impurities in the hole. This problem can be found in the appearance inspection, so it can be controlled by the feeding inspection and requires the PCB plant to improve.


9. [Poor size]
There are many possible reasons for the poor size. It is easy to shrink in the PCB production process. Suppliers have adjusted the drilling program / graphics ratio / molding CNC program, which may cause problems such as biased bias and poor structural parts. Because it is difficult to check such problems, it can only be controlled by the supplier’s good process, so special attention needs to be paid to it when choosing the supplier.

Emphasizing quality control in PCB assembly is critical to improving product quality, reducing costs and protecting intellectual property. Therefore, we encourage our customers to select suppliers with strong quality control systems to ensure the reliability of their products.

At LST, we understand the importance of quality control in PCB assembly and are committed to providing our customers with high quality products. With our extensive experience in the field and state-of-the-art equipment, we can produce PCBs that meet the highest industry standards.