Briefly describe the relevant standards of component product quality grade and military industry screening basis

Date：2021-08-03 10:22:00Views：1561

First, let's learn about component screening. Electronic component testing and screening service is also called secondary screening of electronic components. The secondary screening of electronic components refers to the screening of electronic components by the user or a third party entrusted by the user on the basis of the screening of component manufacturers. Secondary screening is a series of targeted tests based on various failure modes of electronic components, so as to effectively eliminate early failure. In order to ensure the quality of components, China has formulated a series of component standards. The 7905 technical agreement of the "seven specialties" formulated in the late 1970s and the 8406 technical conditions of the "seven specialties" formulated in the early 1980s (hereinafter referred to as the "seven specialties" conditions). The "seven specialties" technical conditions are the basis for establishing the standards of military industrial components. At present, the components controlled according to the "seven specialties" conditions or their stricter conditions are still the main varieties used by aerospace and other departments.

Electronic component testing runs through the "secondary" screening of products in product design, component selection, component receiving and selection in production stage and product delivery stage. Try to eliminate those defective or early failure devices caused by potential adverse factors such as raw materials, equipment, process and human factors from a batch of components, select qualified components with certain characteristics or judge whether the batch of products are qualified for acceptance, so as to improve the service reliability of products, especially for imported components, Through "secondary screening" to ensure controllable product quality and improve the overall reliability of equipment. Due to the current situation of the design, manufacturing and process of electronic components in China, as well as many uncontrollable factors in the procurement of imported components, the secondary screening of electronic components has become an indispensable part to stimulate the potential design and production defects of electronic components, effectively eliminate early failure products and improve the reliability of the whole system.

necessity:The primary screening items and stress conditions carried out by the component manufacturer are difficult to fully meet the needs of equipment development. Imported components are usually industrial grade or medium and low-grade products, and even fake and shoddy products, which is difficult to ensure quality and reliability.

Objectives:Try to eliminate those defective or early failure devices caused by potential adverse factors such as raw materials, equipment, process, environment and human factors from a batch of components, and select qualified components with certain characteristics.

significance:Through the screening of components, the reliability level of batch use of products is significantly improved. When used under standard working conditions, the product failure rate can be reduced by half to two orders of magnitude, resulting in considerable economic benefits.

characteristic:1. Non destructive test without changing the inherent reliability of components; 2. 100% screening of batch products; 3. Eliminate early failure products and improve the reliability of components; 4. The screening level is determined by the expected working conditions and service life of components.

Since the beginning of military industry in 1980, China's military industrial standardization organization has established GJB system with reference to the military industrial standard (MIL) system. The standards of components and parts include specifications, standards and military technical documents:

a.standard- it mainly includes: General specifications and detailed specifications of components, which are collectively referred to as product specifications.

b.standard- mainly include: Test and measurement standards, quality assurance program and production line certification standards, component materials and parts standards, model naming standards, text and graphic symbol standards, etc;

c.Guide military technical documents- mainly include: Guide for correct selection and use of components, manual for reliable military prediction of electronic equipment, component series spectrum, etc.

Important specifications of components:

There are two levels: General specification (General specification) and detailed specification of components. The general specification specifies the requirements for the quality control of a certain type of components. The detailed specification is the specific military capability and quality control requirements for one or a series of models of a certain type of components. The general specification must be used together with the detailed specification. The product specification of components is one of the basis for component production line certification and component identification, and it is also the main basis for users to select and purchase components.

At present, China's competent department of national defense industry has issued a large number of general specifications for components, but the detailed specifications are not fully matched. Therefore, the device manufacturers often formulate detailed specifications (belonging to the enterprise military standard level) and implement them after being confirmed by the standardization organization.

Military standards for components:

Standard is another form of military industry standard system in addition to standardizing and guiding military industry technical documents. It covers a wide range of categories. For the users of components, it is first necessary to understand the standards of relevant test and measurement methods. Because such standards are important technical support for specifications, understanding the contents of such standards in combination with product specifications, on the one hand, helps to better understand the ability of components to withstand various stresses, on the other hand, provides a reference basis for the user of components to correctly formulate standards or regulations for supplementary screening (secondary screening) or failure analysis, and military documents.

In the development and production of military equipment,The secondary screening (supplementary screening) of components is mainly applicable to the following situations:

The component manufacturer did not conduct a screening.

The user of components cannot obtain the information of primary screening, and does not understand the items and stress of primary screening. Most of the imported components are in this situation.

The items or stress screened by the component manufacturer at one time cannot meet the user's requirements for the quality and reliability of components. The screening requirements of component users are generally determined by the overall unit of model.

For some special screening items, there are no specific provisions in the product specifications of components, and the manufacturer of components does not have the screening conditions.

Components that need to be verified if the component manufacturer has conducted a screening according to the requirements of the contract and specifications or has doubts about the effectiveness of the screening.

Formulation basis of secondary screening procedure for components:

In principle, failure analysis shall be carried out on the failed products according to the on-site use or reliability test statistics of components, so as to find out the failure mode and failure mechanism of various components. Different stresses shall be adopted for the internal defects of components, so that the defective products can be exposed in advance and removed without any damage to the good products. The screening stress shall be verified by a large number of tests, and the failure samples shall be analyzed and determined through full demonstration.

According to current standards, such as gjb584, gjb128, gjb360 and other standards

Consider the reliability requirements of the whole system for components

Consider the environmental conditions, funds and development cycle of components

The screening regulations are not always unchanged. They should be changed according to the improvement of component manufacturing technology and the development of test equipment.

The screening requirements of component users are generally determined by the overall unit of model

The secondary screening of components is a supplement to the primary screening. Based on the items and stress of the primary screening, the service conditions and application environment of components shall be comprehensively considered.

Particularity: each unit undertakes different tasks and has different requirements for product reliability, so there is no unified screening standard.

Conclusion: electronic component testing is the application of testing service industry technology in electronic information industry and an important link in the specific industrial chain of electronic components. The level of testing service technology is closely related to the quality of electronic components. Through effective quality control and scientific screening, electronic component testing can effectively control the performance parameters of electronic components in order to give full play to its role and play a great role in ensuring the quality of components.