Electronic components are the basic components of electronic systems, and are the basic circuit units that can perform predetermined functions and cannot be further divided. Due to the large number and variety of electronic components, their performance, reliability and other parameters have a great impact on the system performance, reliability, life cycle and other technical indicators of the entire electronic product.
Therefore, the correct and effective selection and use of electronic components is an important task to improve the reliability of electronic products. The reliability of electronic components is divided into inherent reliability and use reliability. The inherent reliability is mainly guaranteed by design and manufacturing work, which is the task of component manufacturers.

However, the failure analysis data at home and abroad show that nearly half of the failures of the components are not due to the inherent reliability of the components, but are caused by the improper selection or use of the components by the user. Therefore, in order to ensure the reliability of electronic products, it is necessary to strictly control the selection and application of electronic components.
1. General rules for material selection
1. The selected devices follow the company's normalization principle, and select as few types of materials as possible without affecting the function and reliability.
2. The material whose "preferred level" is "A" in the material code library is preferentially selected.
3. The devices whose life cycle is growing and mature are preferred.
4. Select the devices that were born and descended to go through the special approval process.
5. Carefully select devices whose life cycle is in decline, and prohibit the selection of discontinued devices.
6. For power devices, the package type with smaller RjA thermal resistance and higher Tj junction temperature is preferred.
7. It is forbidden to select devices with package size smaller than 0402 (inclusive).
8. The anti-ESD capability is at least 100V, and anti-static measures are required to be designed.
9. The MSL (moisture sensitivity level) of the selected components cannot be greater than level 5 (inclusive).
10. The model with sealed vacuum packaging is preferred. If the MSL (moisture sensitivity level) is greater than level 2 (inclusive), sealed vacuum packaging must be used.
11. The tape and reel packaging and tray packaging models are preferred. If it is a device with a moisture sensitivity level of 2 or above, it is required to be packaged with a disc-shaped plastic tape, and the disc-shaped plastic tape must be able to withstand a high temperature of 125 °C.
12. For key devices, there are at least two brands of models that can be substituted for each other, and some should consider solution-level substitution.
13. The materials used should meet the requirements of antistatic, flame retardant, anti-corrosion, anti-oxidation and safety regulations.