How to Ensure Component Reliability in PCB Assembly
Component Reliability in PCB Assembly
Printed circuit board (PCB) manufacturers take great care to ensure that their products are of high quality. This includes ensuring that every part is suitable for the circuit’s intended purpose and that all connections are properly soldered. However, problems can occur during the manufacturing process that impact the reliability of the final product in its usage field. These issues can include open and short circuits, as well as improperly soldered components.
Whether the problem is caused by poor PCB design or substandard parts, it’s important to know how to ensure component reliability in a PCB assembly. The best way to achieve this is by understanding the causes of these failure modes and how to correct them.
Incorrect pcb design is the primary cause of many circuit board failures. This can be as simple as leaving too little space between parts, which can lead to shorts that interrupt the flow of electricity. Alternatively, it may be more serious, such as using tin-lead solder balls on a BGA connection that isn’t designed to handle this stress. In either case, the resulting PCBA will fail and be a source of costly repairs.
How to Ensure Component Reliability in PCB Assembly
This can be due to a lack of knowledge, inexperience, or inattention. In some cases, these errors are made intentionally to improve the manufacturing process or to reduce the cost of a component. This is why it’s so important to hire a contract manufacturer that understands and adheres to industry standards. A good CM can also help guide you through the design process, pointing out any areas that need to be changed and explaining how to change them to avoid future failures.
Component selection is another crucial step to ensuring reliable PCBs. Choosing high-quality parts that are rated to meet the circuit’s operating specifications is necessary, but it’s also vital to consider environmental factors such as temperature and voltage that can affect the lifetime of a device. In addition, it’s important to review the track record of the component vendor and supplier to ensure that they can provide long-term reliability.
Thermal simulations are often used to determine if a board will be able to withstand thermal stresses during operation. This is especially important for high-reliability electronics that need to withstand prolonged exposure to heat, such as tin-lead solder. Solder undergoing extended thermal cycling is more likely to crack, which can lead to total bond fragmentation and device failure.
Another common failure mode is poor soldering, which can result in poor conductivity and short circuits. In the worst-case scenario, this can damage other components and lead to a total failure of the entire circuit board. Several tests can be conducted to evaluate soldering, including the dip and look test, wetting balance, and surface mount simulation.
A specialized X-ray machine can also be used to detect solder failures during the manufacturing process. This is particularly effective for examining areas that are difficult to see with an automated optical inspection (AOI) system. The X-rays penetrate the different layers of the circuit board and can reveal solder joints that are hidden from the top-down view of an AOI system.