Analysis of PCB Circuit Board Failure Causes and Repair Solutions

PCB circuit board failures can occur due to various reasons, resulting in the PCB not functioning properly. Since PCBs are used in many electronic products such as wearable devices, aircraft, satellites, and medical equipment, quickly identifying any faults and taking appropriate action is crucial. Any company wishing to keep its electronic devices running smoothly can better address PCB failures, and even prevent them from occurring, by understanding more about the reasons they occur.

Causes of PCB Circuit Board Failures and Repair Solutions:

Plating Voids

Plated through-holes are copper-plated holes on a printed circuit board. These holes allow current to pass from one side of the board to the other. To create these holes, PCB manufacturers drill holes through the material of the circuit board. A layer of copper is then added to the surface of the material and along the walls of these holes through an electroplating process.

The process deposits a thin layer of chemically plated copper on the circuit board during a process called deposition. After this step, additional copper layers are added and etched away to create the circuit image.

While effective, the deposition process is not perfect and can, in some cases, result in plating voids. Plating voids are essentially gaps or holes in the PCB plating, often a result of issues during the deposition process. These plating voids are particularly problematic as defects in the plating of through-holes can prevent current from passing through the holes, resulting in defective products.

The occurrence of these plating voids is due to the uneven coating of the material during the deposition process for some reason. Causes of this include contamination of the material, bubbles entrapped in the material, inadequate cleaning of the holes, insufficient catalysis of copper during the deposition process, or coarse hole drilling. Any of these issues could lead to plating voids along the walls of the circuit holes.

By properly cleaning the material after drilling the holes, defects due to contamination, bubbles, or inadequate cleaning can be avoided. Additionally, following the manufacturer's instructions closely during use, such as recommended drilling frequency, drill feed rate, and drilling speed, can prevent defects caused by incorrect drilling. Hiring a reputable and experienced repair company can avoid both of these problems.

Insufficient Copper Edge Gap

Copper is an incredibly conductive metal used as the active component in PCBs. However, copper is also relatively soft and prone to corrosion. To prevent corrosion and protect the copper from interacting with its environment, this copper is covered with other materials. However, when trimming PCBs, if the copper is too close to the edge, it can also trim part of this coating, exposing the underlying copper layer. This can lead to many problems with the circuit board's functionality.

On one hand, the exposed copper layer may come into contact with other conductive materials simultaneously, causing a short circuit. This exposure also opens the copper to the environment, making it susceptible to corrosion. This exposure also increases the chances of someone coming into contact with the PCB and receiving an electric shock.

This problem can be easily avoided by ensuring that the space between the copper cover edge and the board edge (also known as the copper cover edge or board edge gap) follows acceptable PCB type standards.

Poor Soldering

Improper soldering during the PCB assembly process can lead to significant problems. A common soldering defect occurs when technicians do not adequately heat the solder, resulting in a common defect known as cold solder, which leads to PCB failure. Additionally, moisture during the soldering process can contaminate PCB pads and other components. This contamination can cause PCB components to burn out and create connectivity issues. We often use visual or X-ray inspection to detect soldering defects.

Conclusion

In conclusion, PCB circuit board failures can have various causes, but they can often be prevented or mitigated by following proper manufacturing and assembly processes. Regular inspection and maintenance can also help identify and address potential problems early, ensuring the smooth operation of electronic devices. By understanding the causes of PCB failures and implementing appropriate repair solutions, companies can minimize downtime and maintain the reliability of their electronic products.