The printed circuit board is a very important part of electronic products, and the quality of the PCB board directly affects the performance and function of the entire product.
In the entire process of PCBA SMT, a lot of problems including processing errors, improper use and aging of components and other factors will appear and affect normal work or even the use of real products.
During the manufacturing, assembly and use of the PCB, due to various reasons, different degrees of failure may occur, and repairs are required. The PCBA repair requires certain skills and experience, and the following is an introduction to some skills about PCBA repair .
Determine the point of failure
In the PCBA repair, we need to determine the point of failure first, to find the components or connections that caused the board failure. The point of failure can be determined by examining the components on the board, observing hot spots on the board, using test instruments, and so on.
Soldering analysis and detection
Basically 80% of the defects of the circuit board are the problems of the solder joint. We can use X-RAY inspection equipment to check whether there are false solder, fake solder, bubble, short circuit, whether the copper is obviously warped and other defects that are not visible to the naked eye.
Use the right tools
PCBA repair require the right tools, including multimeters, soldering irons, heat guns, solder suction devices, and more. Using the right tools can make it easier to detect board faults and make component replacement and soldering easier.
Check electronic components
When performing PCBA repairs, each component needs to be carefully inspected to determine whether it is faulty. Test instruments such as multimeters can be used to detect the resistance, capacitance, voltage, current and other parameters of components to determine whether the components are working normally.
When PCBA repair in the SMT processing, the first thing to determine is that each solder joint components have no error, leakage, reverse problems. Besides, confirming the authenticity of material is also a situation to consider. If the error, omission, reverse and authenticity of the problem is eliminated, we need to check the faulty circuit board that whether it is intact, whether the components are obviously burned out and whether there is no insertion.
If all the naked eyes can not judge whether there is an abnormality, we can use XRAY detection equipment. X-RAY testing equipment is mainly used for SMT, LED, BGA, CSP flip chip detection, semiconductors, packaging components, lithium battery industry, electronic components, auto parts, aluminum die-casting mold castings, molded plastics, ceramic products and other special industries testing.
Replace the faulty component
Replace the faulty component: After determining that the component is faulty, the faulty component needs to be replaced in time. Replacing components requires the use of the right tools and methods, and following the correct soldering process to avoid secondary damage to the board.
Before replacing faulty components in SMT processing and PCBA repair, we need to prepare an electric soldering iron with ground wire and temperature control.
Place the heated soldering iron tip directly on the upper surface of the faulty component, and after the solder on both sides of the faulty component and the adhesive under the component melt at high temperature, the damaged component is taken out directly with tweezers.
After removing the damaged component, the remaining tin on the board needs to be sucked up with a tin strip, and then the adhesive and other stains on the original PCB pad are wiped clean with alcohol.
PCBA cleaning
After PCBA repairing, the board needs to be cleaned with anhydrous alcohol or decontaminated water to remove substances such as solder slag that remains during soldering. At the same time, the circuit board can also be treated with anti-static treatment to ensure the stability and reliability of the circuit board during use.
Conclusion
In summary, PCBA repair requires certain skills and experience, including steps such as identifying the point of failure, using the right tools, checking electronic components, replacing faulty components, and cleaning the board. When carrying out PCBA repair, it is necessary to pay attention to safety, follow the correct operation process and soldering process to ensure the quality and stability of the circuit board, so as to ensure the normal operation of the entire electronic product.
