Basic knowledge of reliability testing of electronic products

Date：2021-12-28 13:22:00Views：901

Generally speaking, the test conducted to evaluate and analyze the reliability of electronic products is called reliability test. It is to predict the quality from the delivery of products to the end of their service life. After selecting the environmental stress with high similarity to the market environment, set the degree and application time of environmental stress. The main purpose is to correctly evaluate the reliability of products in a short time as possible.

Reliability test can be divided into environmental test, life test, special test and field service test. The reliability test of electronic products generally includes: high and low temperature, temperature impact, transportation vibration, drop, high accelerated life test, etc. Among them, high accelerated life testing (halt test for short) is a process of revealing design defects and deficiencies by using the vibration system of rapid high and low temperature transformation for electronic and mechanical assemblies. The purpose of halt is to identify the function and failure limit of the product in the early stage of product development, so as to optimize the reliability of the product. The reliability test technology of halt has been widely concerned and recognized in the electronic industry at home and abroad.

Physical property test items

1. Internal water vapor: determine the water vapor content in the gas inside the optoelectronic device encapsulated in metal or ceramic.

2. Tightness: determine the air tightness of optoelectronic device package with inner cavity.

3. ESD value: determine the sensitivity and sensitivity of optoelectronic devices to damage and degradation caused by electrostatic discharge.

4. Flammability: determine the flammability of materials used in optoelectronic devices.

5. Shear force: determine the integrity of materials and processes used by chips and passive components of optoelectronic devices installed on sockets or other substrates.

6. Solderability: determine the solderability of optoelectronic device leads (leads with diameter less than 30175mm and flat leads with equivalent cross-sectional area).

7. Wire bonding strength: determine the wire bonding strength of optoelectronic devices using low temperature welding, hot pressing welding, ultrasonic welding and other technologies.

Significance of reliability test of electronic products

Reliability test is a means to investigate, analyze and evaluate the reliability of products. The test results provide a basis for fault analysis, study the corrective measures taken and judge whether the product meets the index requirements.Specific meanings include:

(1) Find various defects in product design, components, parts, raw materials and processes;

(2) Provide information to improve product integrity, improve task success, and reduce maintenance labor costs and support costs;

(3) Confirm whether it meets the reliability quantitative requirements.

In order to achieve the above purpose, laboratory test or field test can be carried out according to the situation.

The laboratory test is a simulation test in a certain way. The test profile should conform to the environmental profile used as much as possible, but it is not restricted by the site. It can be carried out in each stage of product development, development, production and use. It has the characteristics of typicality of environmental stress, accuracy of data measurement and integrity of records. Through the test, we can continuously deepen the understanding of product reliability, and provide basis and verification for improving product reliability.

Field test is the test of the product on the use site. The test profile is real but uncontrolled, so it is not typical. Therefore, it is necessary to record and analyze the impact of environmental conditions, measurement, failure, maintenance and other factors on the site. Even so, it is still difficult to obtain timely reliability evaluation information from the field test. Unless several equipment are placed on the site for use until they are worn out, it is possible to accurately evaluate their reliability after faithfully recording the fault information. When the system is large and difficult to test in the laboratory, the on-site reliability test of prototype and small batch products is of great significance.