electronic components are the basic elements in electronic circuits. They are usually individually packaged and have two or more leads or metal contacts. Electronic components must be interconnected to form an electronic circuit with specific functions, such as amplifiers, radio receivers, oscillators, etc. One of the common ways to connect electronic components is to solder them onto a printed circuit board. Electronic components may be individual packages (resistors, capacitors, inductors, transistors, diodes, etc.) or groups of various complexities, such as integrated circuits (operational amplifiers, transistors, logic gates, etc.).

There are two ways to describe the reliability of electronic components, namely quality protection grade and failure rate grade. Among them, the former is mostly used to evaluate the reliability level of some components and electronic devices accordingly, while the latter is more suitable to explain the reliability level of most electronic components. If GJB/Z299B is used as the basis to predict the reliability of electronic equipment, the parameter "quality grade" is usually required.

At present, failure rate is mainly used to quantitatively describe whether a product is reliable. This characteristic number refers to the probability of a product that has been in a normal operating state until a certain moment experiencing failure problems within a unit of time after reaching that moment. As the main basis for judging the reliability of a product, the failure rate grade is often closely related to the quality and reliability level of components. At present, the expression methods adopted by various versions of the national military standards usually have clear differences. For example, GJB65A-91 divides the corresponding failure rate grades of relays into four levels, from low to high as Y/W/L/Q levels, and points out that capacitors also follow the above regulations. GJB244-87 classifies the failure rate grades of components into four levels: W/L/Q/B. For components such as electrical connectors and mica capacitors that are produced by the national military standard production line, have been certified and are documented in the product catalog but lack reliable indicators, relevant personnel usually describe their warranty grades as J