With the development of electronic technology, the application number of electronic components in equipment is increasing gradually, and the reliability of electronic components is also put forward higher and higher requirements. Electronic components are the basis of electronic equipment and the basic resources to ensure the high reliability of electronic equipment, whose reliability directly affects the full play of the working efficiency of equipment. In order to help you in-depth understanding, the following content is provided for your reference.
Definition of reliability screening:
Reliability screening is a series of checks and tests to select the products with certain characteristics or eliminate the early failure of the products.
Reliability screening Purpose:
One: Pick out the products that meet the requirements.
Two: eliminate the early failure of products.
Reliability screening significance:
The reliability level of a batch of components can be improved by screening out the early failure products. Under normal conditions, the failure rate can be reduced by half to one order of magnitude, and even two orders of magnitude.
Reliability screening features:
(1) It is a non-destructive test for products without defects but with good performance, while for products with potential defects, it should induce their failure.
(2) Reliability screening is 100% test, not sampling inspection. After screening tests, no new failure modes and mechanisms should be added to the batch.
(3) Reliability screening cannot improve the inherent reliability of products. But it can improve the reliability of the batch.
(4)Reliability screening generally consists of multiple reliability test items.
Classification of reliability screening:
Reliability screening can be divided into routine screening and special environment screening.
Products used under general environmental conditions only need to undergo routine screening, while products used under special environmental conditions need to undergo special environmental screening in addition to routine screening.
The selection of actual screening is mainly determined according to the failure mode and mechanism of the product, according to different quality grades, combined with reliability requirements or actual service conditions and process structure.
Routine screening is classified according to screening properties:
① Examination and screening: microscopic examination and screening; Infrared non-destructive screening; PIND. X – ray non – destructive screening.
② Sealing screening: liquid immersion leak screening; Helium mass spectrometry leak detection screening; Radioactive tracer leak screening; Humidity test screening.
(3) Environmental stress screening: vibration, impact, centrifugal acceleration screening; Temperature shock screening.
(4) Life screening: high temperature storage screening; Power aging screening.
Screening under special use conditions – secondary screening
The screening of components is divided into “primary screening” and “secondary screening”.
The screening conducted by the component manufacturer in accordance with the product specifications (general specifications, detailed specifications) of the components before delivery to the user is called “primary screening”.
The re-screening conducted by the component user according to the usage requirements after procurement is called “secondary screening”.
The purpose of secondary screening is to select the components that meet the requirements of the user through inspection or test.
(secondary screening) scope of application
The component manufacturer does not carry out the “one-time screening”, or the user does not have a specific understanding of the “one-time screening” items and stresses
The component manufacturer has carried out “one-time screening”, but the item or stress of “one-time screening” cannot meet the quality requirements of the user for the component;
There are no specific provisions in the specification of components, and the component manufacturer does not have special screening items with screening conditions
The components that need to be verified as to whether the manufacturer of the components has carried out the “one screening” according to the requirements of the contract or specifications, or if the validity of the contractor’s “one screening” is in doubt
Screening under special use conditions – secondary screening
The “secondary screening” test items can be referenced to the primary screening test items and tailored appropriately.
The principles for determining the sequence of secondary screening items are:
(1) Low cost test items should be listed in the first place. Because this can reduce the number of high-cost testing devices, thus reducing costs.
(2) The screening items arranged in the former shall be conducive to the exposure of defects of components in the latter screening items.
(3) It is necessary to carefully consider which of the two tests, sealing and final electrical test, comes first and which comes second. After passing the electrical test, the device may fail due to electrostatic damage and other reasons after the sealing test. If the electrostatic protection measures during the sealing test are appropriate, the sealing test should generally be put last.
Post time: Jun-16-2023
