As we all know, electronic components are components of electronic components and small machines and instruments. They are often composed of several parts and can be used in similar products. Often refers to electrical appliances, radio, instrument and other industrial parts, such as capacitors, transistors, springs, clockwork and other sub-devices. Common are diodes and so on. But how to choose and apply in many electronic components?

The selection of electronic components should at least follow the following guidelines:

1. Give priority to components from manufacturers with good technical services, timely delivery and reasonable prices. For the key components to carry out the user to the quality of the manufacturer;

2. Give priority to the standard components with stable quality, high reliability and promising development proved by practice, and do not allow the selection of obsolete and forbidden components;

3. The technical conditions, technical performance and quality level of components should meet the requirements of equipment;

4, should maximize the compression of components specifications and manufacturers;

5, when the performance-price ratio is equal, domestic components should be preferred.

6. Components that have not been designed and finalized cannot be formally used in military products with high reliability requirements;

The following issues should be considered in the application of electronic components, and effective measures should be taken to ensure the application reliability of electronic components:

1. Radiation resistance. The components used in spacecraft are often damaged by various rays from the sun and the Milky Way, which can render the entire electronic system ineffective, so designers must consider the effects of radiation. At present, some radiation hardened semiconductor devices have been developed at home and abroad, and such components should be used when needed.

2. Damage during operation. It is easy to cause mechanical damage to semiconductor devices and integrated circuits during operation, which should be paid attention to in structure design, assembly and installation. Such as lead forming and cutting, printed circuit board installation, welding, cleaning, heat dissipation plate, device layout, printed circuit board coating and other processes, should strictly implement the electrical installation process regulations.

3. Storage and safekeeping problems. Improper storage and storage is an important reason for the reliability reduction or failure of components, which must be paid attention to and corresponding measures should be taken. If the temperature and humidity of the warehouse should be controlled within the specified range, it should not lead to the existence of harmful gases; The container for storing the device should be made of materials that are not easy to carry static electricity and do not cause chemical reactions of the device. Regularly check the components with test requirements, etc.

4, anti-static damage. In the process of manufacturing, storage, transportation and assembly of semiconductor devices, due to the relative movement of equipment, materials and operators, electrostatic voltages of several thousand volts may be generated due to friction. When the device is in contact with these charged bodies, the charged bodies will discharge through the device "lead leg", causing device failure. Not only MOS devices are sensitive to electrostatic discharge damage, but also bipolar devices and hybrid integrated circuits.

5. Thermal design. Thermal failure of electronic components is caused by material deterioration of components caused by high temperature. As the density of electronic components used in modern electronic equipment is getting higher and higher, thermal coupling occurs between components through conduction, radiation and convection, and thermal stress has become one of the important factors affecting the reliability of components. Therefore, in the process of layout and installation of components, thermal factors must be fully considered, and effective thermal design and environmental protection design must be adopted.

6, the use of derating. Experience has shown that an important reason for the failure of a component is due to its operation above the allowable stress level. Therefore, in order to improve the reliability of components and extend their service life, it is necessary to consciously reduce the working stress (electrical, thermal, mechanical stress) imposed on the components so that the actual use stress is lower than the rated stress specified. This is the basic meaning of the use of derating.