PCBA Tech - PCBA repair process

PCBA repair process
At present, the country has higher and higher requirements for environmental protection and greater efforts in link governance. This is a challenge but also an opportunity for PCB factories. If PCB factories are determined to solve the problem of environmental pollution, then FPC flexible circuit board products can be at the forefront of the market, and PCB factories can get opportunities for further development.
In the production and use process of SMT patch processing, due to the problems in the entire PCBA manufacturing process and use process, problems such as processing errors, improper use, and component aging will occur. Because many products do not need to be replaced completely. This requires certain repairs and maintenance of the internal circuit board. Then it comes to the repair of the circuit board!

Under normal circumstances, the maintenance technology of our patch processing plant will perform the following operations.

1. Check the components

When the product needs to be repaired in the SMT chip processing plant, it is first necessary to determine whether the components of each solder joint have errors, leaks and inversions. Confirming the authenticity of no materials is also a situation that needs to be considered. Not all are better than North China. If errors, leakage, upside-down and authenticity are eliminated, a faulty circuit board can be obtained. First, check whether the circuit board is in good condition, whether the components are obviously burned out and inserted correctly.

2. Welding status analysis

Basically 80% of the defects of the circuit board are the defects of the solder joints. Whether the solder joints are comprehensive and abnormal, first of all, please refer to the ISO9001 quality system management standard, and various SMT processing welding quality standards to check whether there are defective welding, false welding, short circuit, whether the copper skin is obviously improved and other visible to the naked eye defect. If so, you need to repair the defect of this product, if not, you can proceed to the next step!

3. Component orientation detection

In this link, we basically ruled out some visual defects. Now we must carefully check diodes, electrolytic capacitors, etc. The most used components on the circuit board, there are other prescribed directions, or is the negative pole of the component needed for the positive pole inserted in the wrong direction?

4. Parts tool inspection

5. If all the naked eyes judge that there is no problem, we need to borrow some auxiliary tools at this time. The most commonly used SMT chip processing factory uses a multimeter to directly measure resistance, capacitance, transistors and other components. The most important thing to check with a multimeter is to check whether the resistance value of these components does not meet the normal value and becomes larger or smaller. Whether the capacitor is open, whether the inductance is open, etc.

5. Power-on test

After the above process is completed, the conventional problems of the parts are basically eliminated. After the power is turned on, the circuit board will not be damaged by ablation due to short circuit or bridging. Turn on the power and check whether the corresponding function of the circuit board is normal

Basically, when all the processes are completed, the customer's BOM and Gerber are removed, and the schematic diagram can be used to judge and repair customer product defects. In the patch processing plant, the technicians in our maintenance department are carefully selected from the professional players in the workshop.