Can X-ray detect faulty soldering? Detection method of false soldering of circuit board

Date：2022-04-02 17:26:56Views：1705

At present, most of the electronic components commonly used in integrated circuits are sealed with epoxy resin or other glue and alloy, and there is often the phenomenon of circuit board soldering. Therefore, detecting circuit board soldering is a very important link.

False soldering of circuit board has always been a common problem in the electronic industry. Due to the compact and complex internal structure and miniaturized shape of electronic products, ordinary testing instruments can not detect their internal defects. Therefore, it is difficult to solve the problem of how to effectively detect false soldering of circuit board. To solve this problem, the skilled workers in the factory came up with various methods:

1. Visual inspection method

Generally, first look for heating components, such as power tubes, high-current diodes, high-power resistors, integrated circuits, etc. these components are prone to false soldering due to heating, which can be seen directly in serious cases, and can be viewed with a magnifying glass in slight cases. Generally, the newly welded pins are very smooth. When the edge is affected, it will become rough and dull due to continuous extrusion and stretching, and gray circles will appear around the solder joint. When viewed with a high-power magnifying glass, you can see the small crack group in the shape of crack, and in serious cases, it will form a ring crack, that is, desoldering. There is no hidden danger of ring welding, even if there is no black ring in the future. Large area repair welding of integrated circuits and heating element pins is one of the solutions.

2. Current detection method

Check whether the current setting complies with the process regulations and whether the current setting does not increase accordingly when the product load changes, resulting in poor welding due to insufficient current during welding.

3. Shaking method

It is to shake the low-voltage components one by one with your hand or camera to feel whether the components are loose. This is mainly to shake the larger components. In addition, before using this method, the fault range should be compressed to determine the approximate range of the fault, otherwise it will face many components. It is unrealistic to shake one by one.

4. Vibration method

When the phenomenon of false soldering is encountered, it can be confirmed by knocking. Gently tap the circuit board with a screwdriver to determine the position of the false soldering point. However, when the percussion method is adopted, the personal safety and the safety of the equipment shall be ensured to avoid expanding the fault range.

5. Repair welding method

Repair welding is a maintenance method when the fault can not be found after careful inspection, that is, welding the components within the fault range one by one. In this way, although no real fault point is found, the purpose of maintenance can be achieved.

After many experimental studies, X-ray detection equipment has been recognized by more and more people. The efficiency and effect of its circuit board false soldering detection are both worry-saving and labor-saving.

When the X-ray detection equipment transmits the circuit board, the part of the circuit board with faulty welding, the broken part of the circuit board, or the hollow part of the circuit board will have different X-ray absorption capacity due to the different distribution density of solder metal. Because the ray intensity penetrating the defective part is higher than that of the non defective part, the parts of circuit board faulty welding, circuit board cavity and circuit board fracture can be detected by detecting the difference of ray intensity penetrating the object.

Shenzhen Chuangxin Online Testing Technology Co., Ltd. is a well-known professional testing organization for electronic components in China. It has three standardized laboratories with an area of more than 1000 square meters. The scope of testing services covers: testing and verification of electronic components, identification of IC authenticity, product design, material selection, failure analysis, function testing, factory incoming material inspection, X-ray testing of components, tape braiding and other testing items.