What are the criteria for the detection and screening of electronic components?

Date：2023-02-02 16:06:11Views：360

In the formal industrial production, there are special screening and testing workshops for components, which are equipped with many general and special screening and testing equipment and instruments. For example, if they are not screened and tested before installation, once they are welded into the printed circuit board, it is found that the circuit cannot work properly, and then go to check, which not only wastes a lot of time and energy, but also is easy to damage the components and printed circuit board by disassembling.

Appearance quality inspection

After getting an electronic component, check its appearance for obvious damage. For example, for transformers, check whether all leads are broken, whether the appearance is rusted, and whether the wire package and framework are damaged. For example, check whether the appearance of the triode is damaged, whether the pin is broken or rusted, and whether the model on the device is legible. For adjustable elements such as potentiometers and variable capacitors, it is also necessary to check whether the movement is smooth and flexible, whether the tightness is appropriate, whether there is no mechanical noise, good hand feeling, and ensure good contact of all contacts within the adjustment range.

Various electronic components have their own characteristics and requirements. Fans should learn more about the performance, parameters and characteristics of various components and accumulate experience.

Screening of electrical performance

The screening of electronic components is an essential process to ensure that the trial-produced electronic device can work stably and reliably on power for a long time, and can withstand the test of application environment and other possible factors. The so-called screening is to apply one or more stress tests on electronic components to expose the inherent defects of components without damaging their integrity. The screening theory is that if the test and stress level are selected properly, the inferior products will fail, and the superior products will pass. It is found in the long-term production practice that the newly manufactured electronic components have a high failure rate when they are just put into use, which is called early failure. After early failure, the electronic components enter the normal service life stage. Generally speaking, in this stage, the failure rate of electronic components will be greatly reduced. After the normal use stage, the electronic components will enter the wear and aging stage, which will mean the end of life. This law, like a bathtub curve, is called the efficiency curve of electronic components.

The failure of electronic components is caused by improper raw materials or technological measures used in design and production. The early failure of components is very harmful, but inevitable. Therefore, people can only artificially create early working conditions, so as to eliminate the inferior products before making products, so that the components used for product production can enter the normal use stage at the beginning, reduce the failure and increase its reliability.

In a formal electronic factory, the aging screening items used generally include: high temperature storage aging; High and low temperature cycling aging; High and low temperature impact aging and high temperature power aging, etc. High-temperature power aging is to power on the tested electronic components, simulate the actual working conditions, and experience the high temperature of+80 ℃ -+180 ℃ for several hours. It is an effective measure that can check various potential failures of components, and is also the most widely used method at present. For amateurs, it is unlikely to adopt these methods for aging detection in the process of single electronic production. In most cases, natural aging is adopted. For example, store the components for a period of time before use, so that the electronic components can naturally experience the test of high temperature in summer and low temperature in winter, and then test their electrical performance to see whether they meet the use requirements, and save the best and eliminate the worst.

In the screening of electronic components, attention should be paid to quality control, overall consideration, scientific selection, simplified design, reasonable use of performance parameters of components, and play the role of electronic components. The selection of components and parts should be balanced, and the reasonable selection should be made according to the favorable conditions. The circuit design should be simplified to improve the reliability, and the derating use should improve the reliability. Our company has a team of professional engineers and industry elites, and has three standardized laboratories with an area of more than 1800 square meters, which can undertake various test projects such as electronic component testing and verification, IC authenticity identification, product design and material selection, failure analysis, functional testing, factory incoming material inspection and tape weaving.