A product low-cost reliability test profile design method

Abstract

The application provides a product low-cost reliability test profile design method, which comprises the following steps: analyzing stress factors and total time of a specified single-cycle reliability test profile T and further comprises the following steps: decomposing the single-cycle reliability test profile into stress level combinations of different levels of stress factors; determining stress combination time without vibration, normal temperature and normal humidity stress and stress combination time with abnormal temperature and humidity stress or vibration; designing a low-cost reliability test profile containing test profiles outside and inside a test box; and decomposing stress combinations according to the designed low-cost reliability test profile containing test profiles outside and inside the test box. In the case of meeting the unchanged cumulative test stress experienced by the electromechanical equipment, the reliability test is split into comprehensive stress test bench test and non-comprehensive stress test bench test, and under the condition of meeting the consistent product reliability verification, the reliability test cost is greatly reduced.

Description

Technical Field

[0001] This invention relates to the technical field of product reliability testing, and in particular to a low-cost method for designing product reliability test profiles. Background Technology

[0002] Most newly developed electromechanical products, especially military products, require reliability testing during technical finalization or acceptance to verify whether their trouble-free continuous operation time under specified conditions meets user requirements. Existing reliability testing for electromechanical equipment generally refers to the "Reliability Qualification and Acceptance Testing" standard. However, for the vast majority of electromechanical products, conducting tests on a comprehensive stress testing platform incurs high costs, ranging from approximately 500 to 2000 yuan per hour. Therefore, a more cost-effective reliability testing method is needed to achieve consistent stress application conditions.

[0003] GJB899A-2009, "Reliability Qualification and Acceptance Testing," released on May 25, 2009, employs a comprehensive stress profile composed of vibration, temperature, humidity, and voltage, and conducts tests on a comprehensive stress test bench consisting of a vibration table and a temperature and humidity test chamber. However, the operation of the comprehensive stress test bench requires significant costs for electricity, water, and gas, resulting in high testing costs. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a low-cost reliability test profile design method. Under the condition that the cumulative test stress experienced by the electromechanical equipment remains unchanged, the reliability test is divided into two parts: a test bench test with comprehensive stress and a test bench test without comprehensive stress. This significantly reduces the cost of reliability testing while ensuring consistency in product reliability verification.

[0005] This invention provides a method for designing a low-cost reliability test profile for a product, including analyzing the stress factors and total time T of a specified single-cycle reliability test profile, and further including the following steps:

[0006] Step 1: Decompose a single cyclic reliability test profile into stress level combinations of various stress factors of different magnitudes;

[0007] Step 2: Determine the stress combination time for stresses without vibration, at normal temperature and humidity, and the stress combination time for stresses with abnormal temperature and humidity or vibration;

[0008] Step 3: Design a low-cost reliability test profile that includes both external and internal test profiles within the test chamber;

[0009] Step 4: Perform stress combination decomposition based on the designed low-cost reliability test profile that includes both the external test profile and the internal test profile of the test chamber.

[0010] Preferably, the stress factors include at least one of temperature, humidity, vibration, and voltage.

[0011] In any of the above schemes, the decomposition preferably includes:

[0012] 1) The magnitude of temperature stress is divided using Δa degrees Celsius as the basic interval;

[0013] 2) The magnitude of humidity stress is divided using the basic interval of Δb% relative humidity;

[0014] 3) For voltage stress, it is divided into three levels: high voltage, nominal voltage, and low voltage.

[0015] 4) For vibration stress, two orders of magnitude are used: vibration stress and non-vibration stress.

[0016] Preferably, in any of the above schemes, the formula for calculating the stress level combination S decomposed from a single cyclic reliability test profile is:

[0017]

[0018] Where n is the total number of stress combinations, i is the stress combination number, and t i The test time T for each stress combination j H represents the temperature order of magnitude in the stress combination. k U represents the humidity level in the stress combination. s V represents the voltage magnitude in the stress combination. t This represents the vibration magnitude in the stress combination.

[0019] In any of the above schemes, step 2 preferably includes adding the time of the stress combination at normal temperature and humidity and without vibration in the stress level combination to obtain the total time T* of the stress combination at normal temperature and humidity and without vibration, and calculating the cumulative time of each order of magnitude of voltage stress within the time T*.

[0020] In any of the above schemes, step 3 preferably includes setting the time of a single cycle of the test profile outside the test chamber to T. w Its temperature is between 15℃ and 35℃, humidity stress is between 20% and 80%, and there is no vibration stress.

[0021] In any of the above schemes, step 3 preferably includes step T. wThe cumulative time of voltage stress of various magnitudes within a time period is used to design the voltage stress in the external test profile of the test chamber. The original reliability test profile is then modified by removing the combination of normal temperature and humidity stress without vibration to obtain the test profile inside the test chamber.

[0022] In any of the above schemes, step 3 preferably includes fine-tuning the rate of change of the discontinuous parts of temperature and humidity in the test profile inside the test chamber, thereby achieving continuous change of temperature and humidity stress.

[0023] In any of the above schemes, step 4 preferably includes decomposing the stress combination according to the calculation formula of the stress level combination S, and comparing the stress combination of the low-cost reliability test profile with the stress combination of the original reliability test profile under the condition that 15℃ to 35℃ is set as one temperature level and 20%-80% relative humidity is set as one humidity level, according to the convention of normal temperature and humidity conditions.

[0024] In any of the above schemes, it is preferred that if the stress combination of the low-cost reliability test profile is inconsistent with the stress combination of the original reliability test profile, step 3 is repeated.

[0025] This invention proposes a low-cost reliability test profile design method. While maintaining a constant stress combination, it extracts the ambient temperature and humidity vibration-free test from the profile, forming a separate test profile. This allows for the testing of this portion of the profile to be conducted without relying on a comprehensive stress testing system, thereby significantly reducing the overall reliability testing cost. Compared to accelerated test profile design methods, this method maintains strict consistency between the cumulative stress of multiple stress combinations and the original reliability test profile, resulting in higher reliability of the test results. Attached Figure Description

[0026] Figure 1 This is a flowchart of a preferred embodiment of the product low-cost reliability test profile design method according to the present invention.

[0027] Figure 2 This is a schematic diagram of a preferred embodiment of a typical reliability test profile according to the product low-cost reliability test profile design method of the present invention.

[0028] Figure 3 This is a schematic diagram showing the results of an out-of-box test profile design according to a preferred embodiment of the product low-cost reliability test profile design method of the present invention.

[0029] Figure 4 This is a schematic diagram showing the results of an in-chamber test profile design according to a preferred embodiment of the product low-cost reliability test profile design method of the present invention. Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0031] Example 1

[0032] like Figure 1 As shown, step 100 is performed to analyze the stress factors and total time T of a specified single-cycle reliability test profile. The stress factors include at least one of temperature, humidity, vibration, and voltage.

[0033] 1. Perform step 110 to decompose the single cyclic reliability test profile into stress level combinations of various stress factors of different magnitudes. The decomposition rules include: 1) For temperature stress, the magnitude is divided using Δa degrees Celsius as the basic interval; 2) For humidity stress, the magnitude is divided using Δb% relative humidity as the basic interval; 3) For voltage stress, it is divided into three magnitudes: high voltage, nominal voltage, and low voltage; 4) For vibration stress, it is divided into two magnitudes: vibration-induced stress and vibration-free stress. The formula for calculating the stress level combination S decomposed from the single cyclic reliability test profile is as follows:

[0034]

[0035] Where n is the total number of stress combinations, i is the stress combination number, and t i The test time T for each stress combination j H represents the temperature order of magnitude in the stress combination. k U represents the humidity level in the stress combination. s V represents the voltage magnitude in the stress combination. t This represents the vibration magnitude in the stress combination.

[0036] Execute step 120 to determine the stress combination time with no vibration, normal temperature, and normal humidity stress and the stress combination time with non-normal temperature and normal humidity stress or vibration. Add the time of the stress combination with normal temperature and normal humidity and no vibration in the stress level combination to obtain the total time T* of the stress combination with normal temperature and normal humidity and no vibration, and calculate the cumulative time of each order of magnitude of voltage stress within the time T*.

[0037] Perform step 130 to design a low-cost reliability test profile that includes both external and internal test profiles within the test chamber. Set the time for a single cycle of the external test profile to T. w Its temperature ranges from 15℃ to 35℃, humidity stress ranges from 20% to 80%, and there is no vibration stress. According to T... wThe cumulative time of voltage stress at various levels within a given time is used to design the voltage stress in the external test profile. The original reliability test profile is modified by removing the ambient temperature, humidity, and vibration-free stress combination to obtain the internal test profile. Fine-tuning the rate of change of temperature and humidity discontinuous portions within the internal test profile is then performed to achieve continuous variation of temperature and humidity stress.

[0038] Step 140 involves performing stress combination decomposition based on the designed low-cost reliability test profile, which includes both external and internal test profiles within the test chamber. Step 4 includes performing the stress combination decomposition according to the calculation formula for the stress level combination S.

[0039] Execute step 150. Based on the agreed-upon normal temperature and humidity conditions, and setting 15℃ to 35℃ as one temperature increment and 20% to 80% relative humidity as one humidity increment, compare the stress combination of the low-cost reliability test profile with the stress combination of the original reliability test profile. If the stress combination of the low-cost reliability test profile is inconsistent with the original reliability test profile, repeat step 130. If the stress combination of the low-cost reliability test profile is consistent with the original reliability test profile, proceed to step 160, and the low-cost reliability test profile design process is complete.

[0040] Example 2

[0041] One existing technical solution is the recommended method in GJB899A-2009 "Reliability Qualification and Acceptance Testing", in which the test profile of a certain type of product is as follows: Figure 2 As shown. It can be seen that, Figure 2 This is a comprehensive stress profile composed of temperature, humidity, vibration, and voltage. Even for stress combinations at normal temperature and humidity without vibration, as defined by current reliability test profiles, continuous testing for a specified duration is required on a vibration-temperature-humidity integrated test system, resulting in high testing costs.

[0042] This invention proposes a low-cost reliability testing method. Under the condition that the cumulative test stress experienced by the electromechanical equipment remains unchanged, the reliability test is divided into two parts: a test bench test with comprehensive stress and a test bench test without comprehensive stress. Thus, under the condition of ensuring consistent product reliability verification, the cost of reliability testing is significantly reduced.

[0043] The specific steps of the invented low-cost reliability test profile design method are as follows:

[0044] 1) Analyze the stress factors and total time T of the specified single-cycle reliability test profile. A typical specified single-cycle reliability test profile includes four types of stress: temperature, humidity, vibration, and voltage.

[0045] 2) The single-cycle reliability test profile is decomposed into combinations of stress factors of different magnitudes. For temperature stress, the magnitude is divided using Δa degrees Celsius as the basic interval, with Δa not exceeding 2. For humidity stress, the magnitude is divided using Δb% relative humidity as the basic interval, with Δb not exceeding 5. For voltage stress, three magnitudes are used: high voltage, nominal voltage, and low voltage. For vibration stress, two magnitudes are used: with vibration and without vibration. The stress magnitude combinations decomposed from the single-cycle reliability test profile are shown below:

[0046]

[0047] Where n is the total number of stress combinations, t i The test time T for each stress combination j H represents the temperature order of magnitude in the stress combination. k U represents the humidity level in the stress combination. s V represents the voltage magnitude in the stress combination. t This represents the vibration magnitude in the stress combination.

[0048] 3) Determine the stress combination time for stresses without vibration, at normal temperature and humidity, and the stress combination time for stresses containing non-normal temperature and humidity stress or vibration. Since normal temperature is defined as 15℃ to 35℃ and normal humidity as 20%-80%, add the times of the stress combinations obtained in 2) for stresses with normal temperature and humidity and without vibration to obtain the total time T* for stress combinations with normal temperature and humidity and no vibration. Then calculate the cumulative time of voltage stress at each order of magnitude within time T*. The total time for stress combinations containing non-normal temperature and humidity stress or vibration is TT*.

[0049] 4) Design a low-cost reliability test profile that includes both external and internal test profiles within the test chamber. The time for a single cycle of the external test profile is T. w The temperature ranges from 15℃ to 35℃, the humidity stress ranges from 20% to 80%, and there is no vibration stress. The voltage stress in the external test profile is designed based on the voltage time of various magnitudes within time T0 in section 3). The original reliability test profile is modified by removing the combination of normal temperature, humidity, and vibration stress to obtain the internal test profile. However, considering the requirement for continuous changes in temperature and humidity stress within the test profile, the rate of change of temperature and humidity discontinuous portions in the internal test profile is fine-tuned to achieve continuous changes in temperature and humidity stress. Since stress application in the external test profile does not require a comprehensive stress testing system, the cost of reliability testing can be significantly reduced.

[0050] 5) Based on the designed low-cost reliability test profile, which includes the test profile outside the test chamber and the test profile inside the test chamber, stress combination decomposition is performed according to formula (1) in 2). Under the condition that 15℃ to 35℃ is considered as one temperature level and 20%-80% relative humidity is considered as one humidity level, the stress combination of the low-cost reliability test profile is compared with the stress combination of the original reliability test profile. If the stress combinations are consistent, the low-cost reliability test profile design process ends; if the stress combinations are inconsistent, return to 4) for design modification.

[0051] Example 3

[0052] Compared to the reliability test profile specified in the current GJB899A-2004, this method extracts the ambient temperature and humidity vibration-free test from the profile while maintaining the same stress combination. This creates a separate test profile, allowing the testing specified for this section to be conducted without relying on a comprehensive stress testing system, thus significantly reducing the overall reliability testing cost. Compared to accelerated test profile design methods, this method maintains strict consistency between the cumulative stress of multiple stress combinations and the original reliability test profile, resulting in more reliable test results.

[0053] The low-cost reliability test profile design method of the present invention divides the specified reliability test profile into two parts: an external test profile and an internal test profile, based on the principle that the cumulative amount of combined stress in the test profile remains unchanged. The sum of the test times for the external test profile and the internal test profile is equal to the specified reliability test profile time.

[0054] The specified reliability test profile consists of four elements: vibration, temperature, humidity, and voltage. Within the test profile, these elements change according to certain requirements, and the duration of vibration does not exceed one-quarter of the total duration.

[0055] The principle of constant stress accumulation means that for a specified reliability test profile and a low-cost reliability test profile, the cumulative amount of each stress combination (temperature, humidity, vibration, voltage) is equal in both test profiles.

[0056] The aforementioned external test profile refers to a profile free from vibration, with a temperature variation range not exceeding 15℃ to 35℃ (normal temperature range) and a humidity variation range not exceeding 20% ​​to 80% (normal humidity range). Conducting tests according to the external test profile does not require a comprehensive stress testing system.

[0057] Example 4

[0058] like Figure 2The figure shows a typical reliability test profile. A single test cycle lasts 24 hours and consists of four types of stress: temperature, humidity, vibration, and voltage. The vibration stress is applied in two phases, each lasting 3 hours. According to formula (1), with 5℃ as a basic temperature level and 5% relative humidity as a basic humidity level, and with 15℃ to 35℃ as a temperature level and 20%-80% relative humidity as a humidity level, the following is obtained: Figure 2 The decomposition results of the stress combination magnitudes of the test profile are shown in Table 1. In Table 1, the temperature magnitudes from 15℃ to 35℃ are expressed as T. r The humidity range of 20%-80% is expressed as H. r The vibration magnitude when there is no vibration is represented by R0, and the vibration magnitude when there is vibration is represented by R1. The low voltage magnitude is represented by V. l The nominal voltage level is expressed in V. m High voltage levels are represented by V. h .

[0059]

[0060]

[0061] Table 1: Stress combination decomposition results obtained from typical reliability test profiles

[0062] Table 1 shows that the total test time under normal temperature, humidity, and vibration-free conditions is 9.25 hours, including test numbers 1, 10, 11, 12, and 21. This includes 2.5 hours for the nominal voltage and 6.75 hours for the low voltage. Therefore, the designed external test profile is shown in the figure below. The time for a single test cycle is 9.25 hours. During the test, only the applied voltage is controlled, and the temperature and humidity are set to the natural temperature and humidity conditions of the laboratory.

[0063] According to such Figure 3 and Figure 4 The test profile shown is subjected to stress combination decomposition using Formula 1. The stress combinations of each order of magnitude obtained are basically consistent with those in Table 1. Therefore, it can be considered that... Figure 3 and Figure 4 For appropriate external test profiles and internal test profiles.

[0064] To better understand this invention, specific embodiments have been described in detail above, but these are not intended to limit the invention. Any simple modifications made to the above embodiments based on the technical essence of this invention still fall within the scope of this invention. Each embodiment in this specification focuses on its differences from other embodiments; similar or identical parts between embodiments can be referred to mutually. For system embodiments, since they basically correspond to method embodiments, the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

Claims

1. A method for designing a low-cost reliability test profile for a product, comprising analyzing the stress factors and total time of a specified single-cycle reliability test profile. T Its characteristics are, It also includes the following steps: Step 1: Decompose a single cyclic reliability test profile into stress level combinations of various stress factors of different magnitudes; the stress level combinations decomposed from a single cyclic reliability test profile S The calculation formula is in, n The total number of stress combinations, i This is the stress combination sequence number. t i The test time corresponding to each stress combination, T j The temperature magnitude in the stress combination H k The humidity level is on the order of magnitude in the stress combination. U s The voltage magnitude in the stress combination, V t This represents the magnitude of vibration in the stress combination. Step 2: Determine the stress combination time for stresses without vibration, at normal temperature and humidity, and the stress combination time for stresses with abnormal temperature and humidity or vibration; Step 3: Design a low-cost reliability test profile that includes both external and internal test profiles within the test chamber; Step 4: Perform stress combination decomposition based on the designed low-cost reliability test profile that includes both the external test profile and the internal test profile of the test chamber.

2. The product low-cost reliability test profile design method as described in claim 1, characterized in that, The stress factors include at least one of temperature, humidity, vibration, and voltage.

3. The product low-cost reliability test profile design method as described in claim 2, characterized in that, The decomposition includes: 1) The magnitude of temperature stress is classified using Δa degrees Celsius as the basic interval; 2) The magnitude of humidity stress is divided using the basic interval of Δb% relative humidity; 3) For voltage stress, it is divided into three levels: high voltage, nominal voltage, and low voltage. 4) For vibration stress, two orders of magnitude are used: vibration stress and non-vibration stress.

4. The product low-cost reliability test profile design method as described in claim 3, characterized in that, Step 2 includes summing the times of the stress combinations under normal temperature and humidity and without vibration in the stress level combinations to obtain the total time of the stress combinations under normal temperature and humidity and without vibration. T * and calculate T *The cumulative time of voltage stress at each level within a given time period.

5. The product low-cost reliability test profile design method as described in claim 4, characterized in that, Step 3 includes setting the time for a single cycle of the test profile outside the test chamber as follows: T w Its temperature is between 15ºC and 35ºC, its humidity stress is between 20% and 80%, and it has no vibration stress.

6. The product low-cost reliability test profile design method as described in claim 5, characterized in that, Step 3 also includes according to T w The cumulative time of voltage stress of various magnitudes within a time period is used to design the voltage stress in the external test profile of the test chamber. The original reliability test profile is then modified by removing the combination of normal temperature and humidity stress without vibration to obtain the test profile inside the test chamber.

7. The product low-cost reliability test profile design method as described in claim 6, characterized in that, Step 3 includes fine-tuning the rate of change of temperature and humidity discontinuities in the test profile inside the test chamber, thereby achieving continuous change of temperature and humidity stress.

8. The product low-cost reliability test profile design method as described in claim 7, characterized in that, Step 4 includes the following steps: according to the stress level combination S The stress combination decomposition is performed using the calculation formula. According to the convention of normal temperature and humidity conditions, under the condition that 15ºC to 35ºC is set as one temperature level and 20%-80% relative humidity is set as one humidity level, the stress combination of the low-cost reliability test profile is compared with the stress combination of the original reliability test profile.

9. The product low-cost reliability test profile design method as described in claim 8, characterized in that, If the stress combination of the low-cost reliability test profile is inconsistent with the stress combination of the original reliability test profile, repeat step 3.

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