Complete machine multi-stress step-down acceleration test method for electronic product

Abstract

The invention discloses an electronic product complete machine multi-stress step-down acceleration test method, which belongs to the technical field of mechanical and electrical product reliability test, and comprises the following steps: preparing a tested object, selecting a sample from each type of single machine as the tested object, placing the selected tested object under a standard or conventional storage condition, and testing the mechanical and electrical product reliability. Periodically measuring and recording performance degradation parameters of each tested object; designing an acceleration factor, and designing an acceleration factor Aw for calculating the time of an acceleration test and an acceleration factor AFc for evaluating the failure rate of the equipment under different stress conditions; carrying out stress comprehensive design; designing a test scheme, and giving out a step-down acceleration test scheme of a final electronic product complete machine; according to the electronic product complete machine multi-stress step-down acceleration test method provided by the invention, the problems of inaccurate acceleration factors, poor environmental stress comprehensiveness, long test period and the like of an existing spaceflight electronic product acceleration test are solved.

Description

Technical Field

[0001] The invention relates to the technical field of reliability testing of electromechanical products, and in particular to a multi-stress step-down accelerated testing method for a complete electronic product. Background Art

[0002] Accelerated testing of electronic products in aerospace systems plays an important role in detecting and verifying product reliability. Reliability design mainly considers reliability distribution and reliability prediction, with the aim of evaluating and verifying reliability indicators. Indicators are mainly divided into three categories: reliability, unreliability and failure rate, as well as life indicators such as various characteristic life and average life related to life. These indicators are the focus and goals of reliability design. There is a close relationship between reliability design methods and accelerated test design, and accelerated life testing is a means to verify these goals. Reliability design ideas can effectively guide stress design, acceleration factor determination, test duration design, etc. in accelerated tests. At this stage, accelerated tests still have the following shortcomings:

[0003] (1) Inaccurate acceleration factor: Accelerated testing usually shortens the test time by increasing stress (such as temperature, voltage, vibration, etc.). However, different stress factors may have different effects on the actual service life of the product, resulting in inaccurate acceleration factors, making it difficult to accurately predict the life of the product under normal conditions;

[0004] (2) Insufficient consideration of comprehensive environmental stress: Accelerated tests are often conducted in laboratories, which makes it difficult to fully simulate the complex and changeable environment of spacecraft storage or actual operation. For example, conditions such as high temperature, high humidity, and vibration are difficult to fully reproduce in accelerated tests, which may lead to test results that are inconsistent with the actual situation;

[0005] (3) Sample quantity limitation: In order to save cost and time, accelerated testing is usually performed on only a limited number of samples, which may not fully capture all possible failure modes;

[0006] (4) Low test efficiency: Due to the complexity of test conditions, equipment debugging and data analysis, the entire test cycle may still be long, especially when conducting comprehensive tests under multiple stress conditions, which consumes more time. At the same time, in order to ensure the reliability and consistency of data, it is often necessary to repeat the test on the same type of product multiple times. This increases the workload and time consumption of the test, further reducing efficiency. Summary of the invention

[0007] The purpose of the present invention is to provide a multi-stress step-down accelerated test method for a complete electronic product, so as to solve the problems existing in the above-mentioned background technology such as inaccurate acceleration factors, poor comprehensiveness of environmental stress, and long test cycle of the existing accelerated test of aerospace electronic products.

[0008] To achieve the above object, the present invention provides a multi-stress step-down accelerated test method for an electronic product, comprising the following steps:

[0009] S1. Prepare the test products. Select one sample from each type of single machine as the test product. Place the selected test products under standard or conventional storage conditions. Regularly measure and record the performance degradation parameters of each test product. The obtained performance degradation parameters will serve as reference and control data for subsequent tests under accelerated conditions.

[0010] S2. Design acceleration factor, designed to calculate the acceleration factor A for the time of the accelerated test w and the acceleration factor AF used to evaluate the failure rate of the device under different stress conditions c ;

[0011] S3. Conduct comprehensive stress design;

[0012] S4. Design a test plan and provide a step-down acceleration test plan for the final electronic product.

[0013] Preferably, the acceleration factor A w The formula is as follows:

[0014]

[0015] Among them, Y is the time of the test under natural conditions, the unit is year, m is the time of the accelerated test, the unit is day, which is set to about 3 months, and t0 is the number of days in a year, 365 days.

[0016] Preferably, the acceleration factor AF c The formula is as follows:

[0017]

[0018] Among them, α is the type of components in the system, n i is the number of components of the ith type, λ ia ,λ iu is the failure rate of the i-th component under accelerated conditions and normal conditions, AF i is the acceleration factor of the ith component. The failure rate of each component under normal operating temperature and accelerated conditions is predicted using the reliability prediction method.

[0019] Preferably, the specific steps of S3 are as follows:

[0020] S31. Determine the temperature stress level. According to the working temperature limit of the test product, experience shows that the working temperature limit of the test product is >85℃ with a large margin. The temperature stress of the accelerated test can be selected to 85℃. Considering the acceleration effect and keeping the failure mechanism unchanged, the maximum value of the temperature acceleration stress is set to 85℃ in a single cycle. Combined with the number of units, the temperature stress of the accelerated test is divided into 3 levels: 85℃, 75℃, and 65℃.

[0021] S32, setting humidity and vibration stress, wherein the humidity and vibration stress are set to be constant stress loading;

[0022] S33, determine the test time and number of cycles, preset the test time to be 3 months, the single cycle time to be 48 hours, and preset 45 cycles;

[0023] S34. Determine the specific stress level and conduct a vibration stress test after each temperature gradient test.

[0024] Preferably, the test scheme of S4 is specifically as follows:

[0025] S41. During the high temperature accelerated test, real-time performance data is collected for each type of single machine;

[0026] S42, periodically collect performance degradation parameters, and collect performance degradation parameters for all single machines once every 48 hours;

[0027] S43, after confirming that the single machine has not failed, vibration loading is performed. After the vibration stress loading is completed, performance degradation parameters of all the single machines are collected again. After confirming that the single machine has not failed, the next cycle is performed;

[0028] S44. Select one unit of each type and place it under standard / conventional storage conditions. Collect the performance degradation parameters of the unit under standard / conventional storage conditions every 48 hours as reference and comparison data for the performance degradation parameters of the unit under accelerated conditions.

[0029] Therefore, the present invention adopts the above-mentioned multi-stress step-down accelerated test method for an electronic product, which has the following beneficial effects:

[0030] (1) Designing two acceleration factors not only shortens the time and improves the test efficiency, but also more accurately predicts the reliability and life of the product in actual use;

[0031] (2) Comprehensively consider various stress factors such as temperature, humidity and vibration, simulate the complex environment in the actual use environment, ensure the comprehensiveness and reliability of the test, and have strong environmental comprehensiveness;

[0032] (3) One sample is selected from each type of single machine. The sample quantity is highly representative, ensuring the scientificity and accuracy of the test;

[0033] (4) By designing the acceleration factor, the test time can be significantly shortened. Due to the shortened test time, more test cycles can be performed in the same time, the test frequency can be increased, and the test equipment and resources can be used more efficiently.

[0034] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is an overall flow chart of a multi-stress step-down accelerated test method for an electronic product of the present invention;

[0036] Figure 2 It is a cross-sectional view of a step-down acceleration test of a multi-stress step-down acceleration test method for an electronic product of the present invention;

[0037] Figure 3 This is a cross-sectional view of an equivalent step-down acceleration test of a multi-stress step-down acceleration test method for an electronic product of the present invention. DETAILED DESCRIPTION

[0038] The following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] like Figure 1 As shown, a multi-stress step-down accelerated test method for an electronic product comprises the following steps:

[0040] S1. Prepare the test products. Select one sample from each type of single machine as the test product. Place the selected test products under standard or conventional storage conditions. Regularly measure and record the performance degradation parameters of each test product. The obtained performance degradation parameters will serve as reference and control data for subsequent tests under accelerated conditions.

[0041] S2. Design acceleration factor, designed to calculate the acceleration factor A for the time of the accelerated test w and the acceleration factor AF used to evaluate the failure rate of the device under different stress conditions c ;

[0042] Assume that the load that the control computer bears after one year of storage is recorded as S0. Assume that the whole machine is required to have a storage life of Y years. If the environmental load S0 is used for the test, the test will go through X sections and take Y years, which obviously does not meet the requirements of the accelerated test. Assume that the accelerated test time is m days (about 3 months), and one year is calculated as t0 = 365 days, then the acceleration factor Aw The formula is as follows:

[0043]

[0044] Similarly, the test cycle of the accelerated test can be obtained from the acceleration factor and the storage life target. accelerate Days are equivalent to Y years of natural conditions testing, accelerated Days are equivalent to one year of natural storage test. The accelerated stress level and stress spectrum are also set according to the acceleration factor.

[0045] The failure rate of the whole machine under accelerated stress and actual environment is calculated by the methods provided in GJB / Z 108A-2006 "Handbook of Reliability Prediction of Electronic Equipment in Non-Working State" and GJB / Z 299D "Handbook of Reliability Prediction of Electronic Equipment". In the storage multi-stress accelerated test of a single machine such as a control computer, the humidity is loaded as normal working stress, the temperature stress is loaded as step-down stress, and the accelerated stress is mainly temperature. The acceleration factor AF is calculated in the following way: c .

[0046] Acceleration Factor AF c The formula is as follows:

[0047]

[0048] Among them, α is the type of components in the system, n i is the number of components of the ith type, λ ia ,λ iu is the failure rate of the i-th component under accelerated conditions and normal conditions, AF i is the acceleration factor of the i-th component.

[0049] The failure rate of each component under normal operating temperature and accelerated conditions is predicted using the reliability prediction method, as shown in Table 1.

[0050] Table 1 Accelerated test time calculation table

[0051]

[0052] Known acceleration factor AF C , then the accelerated test is 100 days, which is equivalent to the actual storage time of the product being 100AF C sky.

[0053] For the three types of test units in this experiment, combined with the failure rates of the unit components and weak links, the product acceleration factor is estimated to be about 73.

[0054] S3. Conduct comprehensive stress design. The specific contents are as follows:

[0055] S31. Determine the temperature stress level. According to the working temperature limit of the test product, experience shows that the working temperature limit of the test product is >85℃ and has a large margin. The temperature stress of the accelerated test can be selected to 85℃. Considering the acceleration effect and keeping the failure mechanism unchanged, the maximum value of the temperature acceleration stress is set to 85℃ in a single cycle. Combined with the number of single machines, the temperature stress of the accelerated test is divided into 3 levels: 85℃, 75℃, and 65℃. The specific stress levels are shown in Table 2 below.

[0056] S32, setting humidity and vibration stress, wherein the humidity and vibration stress are set to be constant stress loading;

[0057] S33, determine the test time and number of cycles, preset the test time to be 3 months, the single cycle time to be 48 hours, and preset 45 cycles;

[0058] S34. Determine the specific stress level, and use vibration stress as the inspection stress. After each step-down temperature ladder test, conduct a vibration stress inspection test.

[0059] Vibration stress refers to "GJB150.16A-2009 Military Equipment Laboratory Environmental Test Method".

[0060] Table 2 Step spectrum reduction settings in a single cycle

[0061]

[0062] The test profile of the product multi-stress step-down accelerated life test is as follows Figure 2 and Figure 3 shown.

[0063] S4. Design a test plan and provide a step-down acceleration test plan for the final electronic product. The specific contents are as follows:

[0064] During the test, a data acquisition system is used to monitor performance indicators and store data in real time to determine whether product performance is in a normal state and whether it meets the technical requirements. The data is compared with performance data measured in other cycles before and during the test to determine the trend of product performance changes.

[0065] Taking each temperature step as an example, the test plan during the test is designed as follows:

[0066] S41. During the high temperature accelerated test, real-time performance data is collected for each type of single machine;

[0067] S42, periodically collect performance degradation parameters, and collect performance degradation parameters for all single machines once every 48 hours (after a single cycle ends);

[0068] S43, after confirming that the single machine has not failed, vibration loading is performed. After the vibration stress loading is completed, performance degradation parameters of all the single machines are collected again. After confirming that the single machine has not failed, the next cycle is performed;

[0069] S44. Select one unit of each type and place it under standard / conventional storage conditions. Collect the performance degradation parameters of the unit under standard / conventional storage conditions every 48 hours as reference and comparison data for the performance degradation parameters of the unit under accelerated conditions.

[0070] Therefore, the present invention adopts the above-mentioned multi-stress step-down acceleration test method for a whole electronic product, and guides the stress selection, multi-stress application method, stress application time and other test spectrum parameters in the step-down acceleration test through design ideas such as electronic product failure mode and reliability analysis, thereby solving the problems of inaccurate acceleration factors, poor comprehensiveness of environmental stress, and long test cycle in the existing aerospace electronic product acceleration test.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A multi-stress step-down accelerated test method for an electronic product, characterized in that: The following steps are involved: S1. Prepare the test products. Select one sample from each type of single machine as the test product. Place the selected test products under standard or conventional storage conditions. Regularly measure and record the performance degradation parameters of each test product. The obtained performance degradation parameters will serve as reference and control data for subsequent tests under accelerated conditions. S2. Design acceleration factor, designed to calculate the acceleration factor A for the time of the accelerated test w and the acceleration factor AF used to evaluate the failure rate of the device under different stress conditions c ; S3. Conduct comprehensive stress design; S4. Design a test plan and provide a step-down acceleration test plan for the final electronic product.

2. The multi-stress step-down accelerated test method for an electronic product according to claim 1, characterized in that: Acceleration factor A w The formula is as follows: Wherein, Y is the time of the test under natural conditions, in years, m is the time of the accelerated test, in days, and t0 is the number of days in a year, 365 days.

3. The multi-stress step-down accelerated test method for an electronic product according to claim 1, characterized in that: Acceleration Factor AF c The formula is as follows: Among them, α is the type of components in the system, n i is the number of components of the ith type, λ ia , iu are the failure rates of the i-th component under accelerated conditions and normal conditions, AF i is the acceleration factor of the i-th component.

4. The multi-stress step-down accelerated test method for an electronic product according to claim 1, characterized in that: The specific steps of S3 are as follows: S31. Determine the temperature stress level. According to the working temperature limit of the test product, the temperature stress of the accelerated test is set to 85°C. Combined with the number of units, the temperature stress of the accelerated test is divided into three levels: 85°C, 75°C, and 65°C. S32, setting humidity and vibration stress, wherein the humidity and vibration stress are set to be constant stress loading; S33, determine the test time and number of cycles, preset the test time to be 3 months, the single cycle time to be 48 hours, and preset 45 cycles; S34. Determine the specific stress level and conduct a vibration stress test after each temperature gradient test.

5. The multi-stress step-down accelerated test method for an electronic product as claimed in claim 4, characterized in that: The S4 test plan is as follows: S41. During the high temperature accelerated test, real-time performance data is collected for each type of single machine; S42, periodically collect performance degradation parameters, and collect performance degradation parameters for all single machines once every 48 hours; S43, after confirming that the single machine has not failed, vibration loading is performed. After the vibration stress loading is completed, performance degradation parameters of all the single machines are collected again. After confirming that the single machine has not failed, the next cycle is performed; S44. Collect the performance degradation parameters of the single machine under standard / conventional storage conditions every 48 hours as reference and control data for the performance degradation parameters of the single machine under accelerated conditions.

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