This standard applies to constant stress life test and accelerated life test of electronic device products (hereinafter referred to as products). It is used to quantitatively analyze the reliability of products. When formulating product technical standards with reliability index requirements, it provides a unified method for identifying product failure rate level, life characteristics, product failure distribution, acceleration equation and acceleration coefficient. GB 2689.1-1981 General principles for constant stress life test and accelerated life test methods GB2689.1-1981 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of Chinawww.bzxz.net
General Rules for Constant Stress Life Test and Accelerated Life Test Methods
GB 2689-1—81
1 Scope of Application
This standard applies to constant stress life test and accelerated life test of electronic component products (hereinafter referred to as products). It is used to quantitatively analyze the reliability of products. When formulating product technical standards with reliability index requirements, it provides a unified method for identifying the failure rate level, life characteristics, product failure distribution, acceleration equation and acceleration coefficient of products. 2 Test Classification
2.1 Life test is divided into working life test and storage life test. 2.2 Accelerated life test is divided into working accelerated life test and storage accelerated life test. 3. Samples
3.1 Sampling The samples participating in the test must be selected from the representative specifications of this product model. In short, the test samples should be essentially the same design, and the reliability quality management and continuous production products should be randomly selected once. 3.2 Number of samples The number of samples for each stress level shall be no less than 10, and for special products no less than 5. 4 Test stress
4.1 Life test In general, the test stress level shall be the rated value specified in the technical standard of the component. 4.2 Accelerated life test In the case of no acceleration factor, a complete accelerated life test shall have no less than four stress levels. To ensure the accuracy of the test, there should be a large interval between the highest stress and the lowest stress. One of the stress levels should be close to or equal to the rated value specified in the technical standard of the product. The highest stress level shall not be greater than the limit stress that the structural material and manufacturing process of the product can withstand, so as not to introduce new failure mechanisms. 4.3 Interval of stress levels To improve the accuracy of the test, the interval of stress levels should be appropriately selected. For example, when temperature stress is used, the interval is:
1/T=1/T4,1/T3=1/T-24
Where: (1/T1/T)/(-1)
1 is the number of stress levels.
T1, T2, T3, T are the absolute temperatures (K) of the 1st, 2nd, 3rd, and 4th stress levels respectively. When electrical stress is used, the interval is:
IgV2-IgV,+4; IgV,= IgV1+ 24
Where: 4=（lgVlgV）（1 1）
1 is the number of stress levels;
Vi, V2, V.., Vi are the voltage values ​​of the 1st, 2nd, 3rd, and 4th stress levels respectively. 5 Failure criteria
5.1 The failure criteria can be the complete failure of the component or the deterioration of the selected parameters to a certain extent. 5.2--If there are more than one failure that meets the failure criteria on a sample, it can only be considered as a failure. 5.3 The failure criteria should be specified in the product standards with reliability indicators. 6 Determination of failure time
6.1 If there is an automatic failure recording device, the time automatically recorded shall be used for calculation. Issued by the State Administration
Proposed by the Fourth Ministry of Machine Building Industry of the People's Republic of China
(1)
(2)
October 1, 1981
Drafted by the Standardization Research Institute of the Fourth Ministry of Machine Building
GB2689.1-81
6.2 When testing by the timing method, if the number of failures measured in a test interval (t-1, t) is r, then in the th test level, the failure time t. of the th product in the th test interval shall be determined as: tk-tk-1 j=1, 2, ...rk
ti.j-th-i+ j
Where: , -1 are two adjacent test moments. 6.3 Failures caused by reasons other than the product itself (such as equipment reasons, human factors, accidents, etc.) during the test should not be counted in the number of failures.
7 Parameter test
7.1 Test cycle The choice of test cycle directly affects the estimation accuracy of product reliability indicators. The length of the test cycle is related to the failure distribution of the product and the magnitude of the applied stress. The principle of determining the test cycle is to be able to understand the failure distribution of the product more clearly without increasing the inspection and testing workload too much, and not to make the failure too concentrated in one or two test cycles. Each stress level group generally has more than five test points (referring to the test points that can detect failed products), and the number of failures at each test point should be as roughly the same as possible.
Note: The selection of the test cycle for a specific product can be determined by referring to previous test experience or with the help of probability paper. 7.1.1 If the number of failures in a certain test cycle is zero, the cumulative failure probability F(t) does not need to be calculated for this cycle. 7.1.2 If the number of failures in the same test cycle r ≥ 2, the cumulative failure probabilities corresponding to these r failure times should be calculated separately. 7.2 Before testing Preparation
7.2.1 Before testing the sample, it should be restored for 2 to 4 hours under the normal atmospheric conditions specified below, or carried out in accordance with the provisions of the relevant product technical standards.
Ambient temperature: +15 to +35℃
Relative humidity: 45 to 75%
Atmospheric pressure: 860 to 1060 mbar
7.2.2 The requirements for the test environment, test instruments and test equipment shall comply with the relevant provisions of the product technical standards. 7.2.3 The test truncation number shall be determined in accordance with the requirements of the relevant data processing method standards. 8 Test records
8.1 The production situation records are provided by the workshop (mainly the main process, main raw materials, production situation, defective product rate and quality management records of the production of this batch of products). 8.2 Failure record Record the failure time, number and failure form in sequence. 8.3 Test record Record the changes in test conditions (such as temperature, relative humidity, voltage, etc.) at the prescribed number of times every day, record abnormal conditions, accidents and analysis conclusions that occur during the test. 9 Preservation of failed samples Failure samples of each stress level group in the test should be preserved separately according to their failure form, and failed samples should have clear numbers.
10 Failure analysis Failure analysis and statistics should be carried out on failed samples: a. Failure form
b. Failure mechanism.
11 Judgment of test effectiveness Judgment of effectiveness is carried out in accordance with relevant standards, and its main contents are: a. Whether the rejection of failure data is appropriate;
b. Whether the life distribution conforms to Assumptions;
c. Accelerated model verification.
12 Test precautions
12.1 Failed samples that do not affect the continuation of the test can continue to participate in the test. 12.2 During the test, care must be taken to prevent failure or degradation of sample parameters caused by sudden changes in stress. 12.3 The time from taking out the sample for testing to putting the sample back for continued testing should generally not exceed 24 hours. 12.4 During the test, the same test instrument and tools should be used for each test. If they must be replaced, they must be measured to ensure the test accuracy.
13 Data processing
14 Test report
a. Test report,
b. Failure standard*
GB 2689.1-81
The data processing of the test shall be carried out in accordance with the standards for data processing methods for life tests and accelerated life tests. The test report should include the following contents:
c. Selection of test samples and stress and test description; d. Model and accuracy of test and testing equipment; e. Arrangement of test data and calculation of reliability index; f. Analysis of the test;
g. Test conclusion.
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