A method, apparatus and equipment for assessing the lifespan of a MEMS accelerometer

Abstract

This specification provides a method, apparatus, and equipment for evaluating the lifespan of MEMS accelerometers, relating to the field of MEMS accelerometers. The method involves applying core stress in steps, monitoring various performance parameters, and obtaining the core stress limit range. Within this limit range, a combined core stress test scheme is constructed to conduct constant-acceleration life tests on the MEMS accelerometer. Based on the constant-acceleration life test data and a performance parameter degradation model, the degradation of performance parameters is analyzed to obtain pseudo-life estimates for multiple performance parameters under different stress levels. Based on these pseudo-life estimates, and according to the core stress of the MEMS accelerometer, a multi-stress accelerated life evaluation model is established between the MEMS accelerometer and temperature, shock, electrical stress, and operating time. This method solves the problem that existing MEMS accelerometer lifespan assessments, typically based on accelerated life tests with a single stress and a single failure mode, cannot accurately assess reliability and lifespan.

Description

Technical Field

[0001] This document relates to the field of MEMS accelerometers, and in particular to a method, apparatus and equipment for assessing the lifespan of a MEMS accelerometer. Background Technology

[0002] The complexity of the working principle and structure of Micro-Electro-Mechanical System (MEMS) accelerometers has limited their industrialization due to reliability issues. MEMS accelerometers measure acceleration and are primarily used in aerospace and military fields. For semiconductor integrated circuits, temperature and electrical stress are significant factors inducing device failure, and these stresses are often used in life testing. However, for MEMS accelerometers, with their complex structure and movable mechanical components, actual use often involves complex stresses such as high temperature, high impact, and overload, leading to microstructure fracture, out-of-tolerance performance parameters (such as zero bias, temperature drift, and bias stability), and electrical stress-induced fracture and engagement problems. Currently, life assessment of MEMS accelerometers is mostly conducted through accelerated life testing based on a single stress and single failure mode, which cannot accurately assess reliability lifespan.

[0003] Therefore, there is an urgent need for a life assessment method to address the problem that existing MEMS accelerometer life assessments are usually based on accelerated life tests with a single stress and a single failure mode, which cannot accurately assess the reliability of the lifespan. Summary of the Invention

[0004] This specification provides a method, apparatus, and equipment for evaluating the lifespan of MEMS accelerometers, which addresses the problem that existing MEMS accelerometer lifespan evaluations are typically based on accelerated life tests with a single stress and a single failure mode, making it impossible to accurately assess reliability and lifespan.

[0005] Firstly, this specification provides a method for evaluating the lifetime of a MEMS accelerometer, including:

[0006] Based on the application environment and working conditions, the core stress is applied in steps, various performance parameters are monitored, the main failure modes and weak points are determined, and the core stress limit range is obtained; wherein the performance parameters include zero bias, scaling factor, nonlinearity, and frequency response;

[0007] Within the core stress limit range, a core stress combination test scheme is constructed, and based on the given reliability and confidence level, the number of test samples and the number of failures for constant accelerated life are determined, and constant accelerated life test is carried out on the MEMS accelerometer.

[0008] Based on constant acceleration life test data, the variation law of performance parameters with time was obtained, and the degradation amount of performance parameters was analyzed according to the performance parameter degradation model. Pseudo-life estimates of the performance parameters of multiple MEMS accelerometers under different stress levels were obtained.

[0009] Based on the pseudo-life estimates of the performance parameters of multiple MEMS accelerometers under different stress levels, and according to the core stress of the MEMS accelerometer, a multi-stress accelerated life evaluation model is established between the MEMS accelerometer and temperature, shock, electrical stress and operating time.

[0010] Optionally, based on a preset reinforcement test scheme, the core stress is applied in steps, and the zero bias, scaling factor, nonlinearity, and frequency response performance parameters are monitored to determine the main failure modes and weak points, thereby obtaining the core stress limit range, including:

[0011] Based on the application environment and working conditions, and based on the enhanced test scheme, stepping high temperature test, stepping electric stress test, and stepping impact test are adopted. After the test, performance testing and comparison and failure analysis are performed.

[0012] Based on the results of the reinforcement test, the core stress affecting the MEMS accelerometer was identified, and the limit range of the core stress and the main failure modes were obtained.

[0013] Optionally, the core stress includes: temperature, impact, and electrical stress.

[0014] Optionally, the core stress combination test scheme includes: constant accelerated test under the same temperature stress and different impact and electrical stress; constant accelerated test under the same impact stress and different temperature and electrical stress; constant accelerated test under the same electrical stress and different temperature and impact stress; and multiple schemes of constant accelerated test under different electrical stress and the same temperature and impact stress.

[0015] Optionally, for the same stress level, the minimum pseudo-lifetime value of the MEMS accelerometer can be taken.

[0016] Optionally, the performance parameter degradation model includes: a linear parametric regression model, specifically:

[0017] f(t)=f(0)+bt+δ (1)

[0018] Where f(t) is the test value of the performance parameter, f(0) is the initial value of the performance parameter, b is the degenerate model parameter, and δ is the model error.

[0019] Optionally, the multi-stress accelerated life evaluation model includes:

[0020]

[0021] Where t is the average lifespan, and f(F) is the relative impact force function. g(I) is the inverse power-law model function, g(I) = C·I -D Where A, B, C, D, E, and G are undetermined constants, k is the Boltzmann constant, parameter T represents temperature stress, F represents impact force, and I represents electrical stress.

[0022] Optionally, the main failure modes include degradation of key parameters such as zero bias, scaling factor, nonlinearity, and frequency response; wire bonding failure; pull-in short circuit; fracture of sensitive structure; and mechanical defects such as cracks and degradation of sealing performance.

[0023] The application environment includes: temperature, humidity, electrical stress, vibration and shock, and magnetic field.

[0024] Secondly, this specification provides a MEMS accelerometer lifetime assessment device, including: a core stress limit range determination module, a constant acceleration lifetime test module, a pseudo-lifetime estimate determination module, and a multi-stress accelerated lifetime evaluation model construction module, wherein:

[0025] The core stress limit range determination module is used to apply core stress in steps according to the application environment and working conditions, monitor various performance parameters, determine the main failure modes and weak points, and obtain the core stress limit range; wherein the performance parameters include zero bias, scaling factor, nonlinearity, and frequency response.

[0026] The constant accelerated life test module is used to construct a core stress combination test scheme within the core stress limit range, and determine the number of test samples and failures for constant accelerated life based on the given reliability and confidence level, and to conduct constant accelerated life test on the MEMS accelerometer.

[0027] The pseudo lifetime estimation module is used to obtain the variation law of performance parameters over time based on constant acceleration lifetime test data, and analyze the degradation amount of performance parameters based on the performance parameter degradation model to obtain pseudo lifetime estimates of the performance parameters of multiple MEMS accelerometers under different stress levels.

[0028] The multi-stress accelerated life evaluation model construction module is used to establish a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and operating time based on the pseudo-life estimates of the performance parameters of multiple MEMS accelerometers under different stress levels and the core stress of the MEMS accelerometer.

[0029] Thirdly, this specification also provides an electronic device, including: a communication interface, a processor, and a memory;

[0030] The processor invokes program instructions from the memory to perform the following actions:

[0031] Based on the application environment and working conditions, the core stress is applied in steps, various performance parameters are monitored, the main failure modes and weak points are determined, and the core stress limit range is obtained; wherein the performance parameters include zero bias, scaling factor, nonlinearity, and frequency response;

[0032] Within the core stress limit range, a core stress combination test scheme is constructed, and based on the given reliability and confidence level, the number of test samples and the number of failures for constant accelerated life are determined, and constant accelerated life test is carried out on the MEMS accelerometer.

[0033] Based on constant acceleration life test data, the variation law of performance parameters with time was obtained, and the degradation amount of performance parameters was analyzed according to the performance parameter degradation model. Pseudo-life estimates of the performance parameters of multiple MEMS accelerometers under different stress levels were obtained.

[0034] Based on the pseudo-life estimates of the performance parameters of multiple MEMS accelerometers under different stress levels, and according to the core stress of the MEMS accelerometer, a multi-stress accelerated life evaluation model is established between the MEMS accelerometer and temperature, shock, electrical stress and operating time.

[0035] The beneficial effects of this invention are as follows:

[0036] This specification provides a method, apparatus, and equipment for evaluating the lifespan of MEMS accelerometers. The method involves applying core stress in steps, monitoring various performance parameters, and obtaining the core stress limit range. Within this limit range, a combined core stress test scheme is constructed to conduct constant-acceleration life tests on the MEMS accelerometer. Based on the constant-acceleration life test data and a performance parameter degradation model, the degradation of performance parameters is analyzed to obtain pseudo-life estimates for multiple performance parameters under different stress levels. Based on these pseudo-life estimates, a multi-stress accelerated life evaluation model is established, considering the core stress of the MEMS accelerometer and its interaction with temperature, shock, electrical stress, and operating time. This method, combined with the actual application environment of the device, proposes coupling multiple stresses such as temperature, vibration, shock, and electrical stress together to conduct accelerated life tests on MEMS accelerometers. Utilizing the principle that the failure mechanism of the accelerometer remains unchanged under normal and accelerated stress levels, the lifespan of the MEMS accelerometer can be evaluated, significantly reducing the time required for normal stress life tests. Attached Figure Description

[0037] The accompanying drawings, which are included to provide a further understanding of this specification and form part of this specification, illustrate exemplary embodiments and are used to explain this specification, but do not constitute an undue limitation thereof. In the drawings:

[0038] Figure 1 This is a schematic diagram of a MEMS accelerometer lifetime assessment method provided in the embodiments of this specification;

[0039] Figure 2 This is a schematic diagram of a MEMS accelerometer life assessment device provided in the embodiments of this specification;

[0040] Figure 3 This is a schematic diagram of an electronic device structure provided in the embodiments of this specification. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of this specification clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments in this specification, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection of this document.

[0042] The technical solutions provided in the various embodiments of this specification are described in detail below with reference to the accompanying drawings. Specific Implementation Example 1:

[0044] This embodiment provides a method for evaluating the lifetime of a MEMS accelerometer. (See also...) Figure 1 Specifically, it includes the following steps:

[0045] Step 102: Apply core stress in steps according to the application environment and working conditions, monitor various performance parameters, determine the main failure modes and weak points, and obtain the core stress limit range; wherein the performance parameters include zero bias, scaling factor, nonlinearity, and frequency response.

[0046] The core stresses mentioned above include: temperature, impact, and electrical stress.

[0047] Specifically, one possible implementation of step 102 is as follows:

[0048] S21. Based on the application environment and working conditions, and based on the enhanced test scheme, step-high temperature test, step-electric stress test, and step-impact test are adopted. After the test, the performance is tested and compared and the failure is analyzed.

[0049] The application environment includes: temperature, humidity, electrical stress, vibration and shock, and magnetic field.

[0050] S22. Based on the results of the reinforcement test, identify the core stress that affects the MEMS accelerometer, and obtain the limit range of the core stress and the main failure modes.

[0051] The main failure modes include degradation of key parameters such as zero bias, scaling factor, nonlinearity, and frequency response; wire bonding failure; pull-in short circuit; fracture of sensitive structures; and mechanical defects such as cracks and degradation of sealing performance.

[0052] Based on this, by determining the limiting range of multiple core stresses, a range basis was provided for subsequent combined tests.

[0053] Step 104: Within the core stress limit range, construct a core stress combination test scheme, and determine the number of test samples and failures for constant accelerated life based on the given reliability and confidence level, and conduct constant accelerated life test on the MEMS accelerometer.

[0054] It should be noted that the core stress combination test scheme includes: constant accelerated test under the same temperature stress and different impact and electrical stress; constant accelerated test under the same impact stress and different temperature and electrical stress; constant accelerated test under the same electrical stress and different temperature and impact stress; and multiple schemes of constant accelerated test under different electrical stress and the same temperature and impact stress.

[0055] Among them, for the same stress level, the minimum pseudo lifetime value of the MEMS accelerometer is taken.

[0056] The method for determining the number of test samples m and the number of failures n for constant accelerated life based on the given reliability R and confidence level φ is as follows:

[0057]

[0058] in, These are probability coefficients;

[0059] It should be further noted that the constant acceleration life test was conducted within the core stress limit range, based on a core stress combination test scheme, providing batch test data under the same stress level for subsequent accelerometer life assessment.

[0060] Step 106: Based on the constant acceleration life test data, obtain the variation law of performance parameters with time, and analyze the degradation amount of performance parameters according to the performance parameter degradation model to obtain the pseudo-life estimate of the performance parameters of multiple MEMS accelerometers under different stress levels.

[0061] The performance parameter degradation model includes: a linear parameter regression model, see formula (1);

[0062] It should be noted that an appropriate mathematical model should be selected based on the variation of accelerometer test parameters over time. The mathematical model includes, but is not limited to, a linear parametric regression model.

[0063] Specifically,

[0064]

[0065] Where, f(t) i，j，k For the j-th accelerometer under the i-th stress at time k t i，j，k The obtained parameter values ​​are: i = 1, 2, ..., p; j = 1, 2, ..., q i k = 1, 2, ..., m ij .

[0066] Then, based on the failure threshold of the performance parameters, and using accelerated life test data combined with the above two equations, pseudo-life estimates of the performance parameters of multiple MEMS accelerometer samples under different stress levels are obtained. For the same stress level, the minimum pseudo-lifetime value of the MEMS accelerometer is taken.

[0067] Step 108: Based on the pseudo-life estimates of the performance parameters of multiple MEMS accelerometers under different stress levels, and according to the core stress of the MEMS accelerometer, establish a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time.

[0068] The multi-stress accelerated life evaluation model is described in formula (2).

[0069] Specifically, the pseudo-lifetime estimates of the performance parameters of multiple MEMS accelerometers under different stress levels obtained in step 106 are... Substituting into formula (2), the specific values ​​of A, B, C, D, E, and G are obtained through approximate estimation, and then the life evaluation model of the MEMS accelerometer under reliability R and confidence φ is determined. The life evaluation model is a function of temperature stress T, impact force F, and electrical stress I.

[0070] Furthermore, using formula (2), the actual application environment of the MEMS accelerometer is input, including temperature stress T, impact stress F, and electrical stress I, to evaluate the lifespan of the MEMS accelerometer under the current application environment.

[0071] The lifetime assessment method provided in this embodiment is applicable to various MEMS accelerometers, including but not limited to MEMS capacitive accelerometers, MEMS piezoresistive accelerometers, and MEMS vacuum-encapsulated accelerometers.

[0072] In summary, this embodiment applies core stress in steps, monitors various performance parameters, and obtains the core stress limit range. Within the core stress limit range, a core stress combination test scheme is constructed to conduct constant accelerated life tests on the MEMS accelerometer. Based on the constant accelerated life test data and performance parameter degradation model, the degradation of performance parameters is analyzed to obtain pseudo-life estimates for multiple performance parameters under different stress levels. Based on the pseudo-life estimates of multiple performance parameters under different stress levels, a multi-stress accelerated life evaluation model is established for the MEMS accelerometer in relation to temperature, shock, electrical stress, and operating time, according to the core stress of the MEMS accelerometer. This embodiment, combined with the actual application environment of the device, proposes to couple multiple stresses such as temperature, vibration, shock, and electrical stress together to conduct accelerated life tests on MEMS accelerometers. Utilizing the principle that the failure mechanism of the accelerometer remains unchanged under normal stress and accelerated stress levels, the life assessment of the MEMS accelerometer can be realized, which can greatly shorten the time required for normal stress life tests. Specific Implementation Example 2:

[0074] This embodiment proposes a method for evaluating the lifetime of a MEMS accelerometer as follows:

[0075] Step 1. MEMS accelerometer performance testing and structural analysis;

[0076] Before the experiment, the performance of all devices was tested, and two devices were selected for structural analysis.

[0077] Step 2. MEMS accelerometer reinforcement test;

[0078] Step 2.1 Based on the application environment and working conditions such as temperature, humidity, electrical stress, vibration, shock and magnetic field, design a strengthening test plan and adopt tests such as step high temperature test, step electrical stress test and step impact test. After the test, perform performance testing and comparison and failure analysis.

[0079] Step 2.2 Based on the results of the reinforcement test, identify the main environmental stresses affecting the MEMS accelerometer, such as temperature, shock, and electrical stress, and obtain the limit range and main failure modes of these stresses.

[0080] Step 3. Accelerated Life Testing

[0081] Step 3.1 Design a stress combination test scheme within the above-mentioned limit range, and determine the number of test samples m and the number of failures n for constant accelerated life based on the given reliability R and confidence level φ, and conduct constant accelerated life test on the MEMS accelerometer.

[0082]

[0083] Step 3.2 Based on the accelerated life test data, analyze the degradation of performance parameters using a mathematical model to obtain pseudo-life values.

[0084] More specifically, a degradation model is established by selecting an appropriate mathematical model (including but not limited to a linear parametric regression model) based on the change law of accelerometer test parameters over time, such as the performance parameter degradation model established based on the linear parametric regression model in this invention, see formula (1);

[0085]

[0086] Where, f(t) i，j，k For the j-th accelerometer under the i-th stress at time k t i，j，k The obtained parameter values ​​are: i = 1, 2, ..., p; j = 1, 2, ..., q i k = 1, 2, ..., m ij .

[0087] Then, based on the failure threshold of the performance parameters, and using accelerated life test data combined with the above two equations, pseudo-life estimates of the performance parameters of multiple MEMS accelerometer samples under different stress levels are obtained. For the same stress level, the minimum pseudo-lifetime value of the MEMS accelerometer is taken.

[0088] Step 4. Establish a multi-stress acceleration model and determine the model parameters.

[0089] A multi-stress accelerated life evaluation model was established for MEMS accelerometers in relation to temperature, shock, electrical stress, and operating time.

[0090] The multi-stress accelerated life evaluation model established in this embodiment is shown in formula (2);

[0091] Where A, B, C, D, E, and G are constants to be determined, and k is the Boltzmann constant.

[0092] Finally, by combining the pseudo-life data obtained in step 3 with formula (2), the accelerated life model of the MEMS accelerometer under reliability R and confidence φ is obtained.

[0093] In summary, this embodiment applies core stress in steps, monitors various performance parameters, and obtains the core stress limit range. Within the core stress limit range, a core stress combination test scheme is constructed to conduct constant accelerated life tests on the MEMS accelerometer. Based on the constant accelerated life test data and performance parameter degradation model, the degradation of performance parameters is analyzed to obtain pseudo-life estimates for multiple performance parameters under different stress levels. Based on the pseudo-life estimates of multiple performance parameters under different stress levels, a multi-stress accelerated life evaluation model is established for the MEMS accelerometer in relation to temperature, shock, electrical stress, and operating time, according to the core stress of the MEMS accelerometer. This embodiment, combined with the actual application environment of the device, proposes to couple multiple stresses such as temperature, vibration, shock, and electrical stress together to conduct accelerated life tests on MEMS accelerometers. Utilizing the principle that the failure mechanism of the accelerometer remains unchanged under normal stress and accelerated stress levels, the life assessment of the MEMS accelerometer can be realized, which can greatly shorten the time required for normal stress life tests. Specific Implementation Example 3:

[0095] This embodiment provides a MEMS accelerometer lifetime assessment device. See [link / reference] Figure 2 It includes: a core stress limit range determination module 201, a constant accelerated life test module 202, a pseudo-life estimation value determination module 203, and a multi-stress accelerated life evaluation model construction module 204, wherein:

[0096] The core stress limit range determination module 201 is used to apply core stress in steps according to the application environment and working conditions, monitor various performance parameters, determine the main failure modes and weak points, and obtain the core stress limit range; wherein the performance parameters include, but are not limited to, zero bias, scaling factor, nonlinearity, and frequency response.

[0097] The constant accelerated life test module 202 is used to construct a core stress combination test scheme within the core stress limit range, and determine the number of test samples and failures for constant accelerated life based on the given reliability and confidence level, and to conduct constant accelerated life test on the MEMS accelerometer.

[0098] The pseudo lifetime estimation module 203 is used to obtain the variation law of performance parameters with time based on constant acceleration lifetime test data, and analyze the degradation amount of performance parameters based on the performance parameter degradation model to obtain pseudo lifetime estimates of the performance parameters of multiple MEMS accelerometers under different stress levels.

[0099] The multi-stress accelerated life evaluation model construction module 204 is used to establish a multi-stress accelerated life evaluation model between the MEMS accelerometer and temperature, shock, electrical stress and working time based on the pseudo-life estimates of the performance parameters of multiple MEMS accelerometers under different stress levels and the core stress of the MEMS accelerometer.

[0100] Optionally, the core stress limit range determination module 201 is specifically used for:

[0101] Based on the application environment and working conditions, and based on the enhanced test scheme, stepping high temperature test, stepping electric stress test, and stepping impact test are adopted. After the test, performance testing and comparison and failure analysis are performed.

[0102] Based on the results of the reinforcement test, the core stress affecting the MEMS accelerometer was identified, and the limit range of the core stress and the main failure modes were obtained.

[0103] Optionally, the core stress includes: temperature, impact, and electrical stress.

[0104] Optionally, the core stress combination test scheme includes: constant accelerated test under the same temperature stress but different impact and electrical stress; constant accelerated test under the same impact stress but different temperature and electrical stress; constant accelerated test under the same electrical stress but different temperature and impact stress; and multiple schemes of constant accelerated test under different electrical stress but the same temperature and impact stress.

[0105] Optionally, for the same stress level, the minimum pseudo-lifetime value of the MEMS accelerometer can be taken.

[0106] Optionally, the performance parameter degradation model includes: a linear parametric regression model, specifically:

[0107] f(t)=f(0)+bt+δ (1)

[0108] Where f(t) is the test value of the performance parameter, f(0) is the initial value of the performance parameter, b is the degenerate model parameter, and δ is the model error.

[0109] Optionally, the multi-stress accelerated life evaluation model includes:

[0110]

[0111] Where t is the average lifespan, and f(F) is the relative impact force function. g(I) is the inverse power-law model function, g(I) = C·I -D Where A, B, C, D, E, and G are undetermined constants, k is the Boltzmann constant, parameter T represents temperature stress, F represents impact force, and I represents electrical stress;

[0112] Optionally, the main failure modes include degradation of key parameters such as zero bias, scaling factor, nonlinearity, and frequency response; wire bonding failure; pull-in short circuit; fracture of sensitive structure; and mechanical defects such as cracks and degradation of sealing performance.

[0113] The application environment includes: temperature, humidity, electrical stress, vibration and shock, and magnetic field.

[0114] In summary, this embodiment applies core stress in steps, monitors various performance parameters, and obtains the core stress limit range. Within the core stress limit range, a core stress combination test scheme is constructed to conduct constant accelerated life tests on the MEMS accelerometer. Based on the constant accelerated life test data and performance parameter degradation model, the degradation of performance parameters is analyzed to obtain pseudo-life estimates for multiple performance parameters under different stress levels. Based on the pseudo-life estimates of multiple performance parameters under different stress levels, a multi-stress accelerated life evaluation model is established for the MEMS accelerometer in relation to temperature, shock, electrical stress, and operating time, according to the core stress of the MEMS accelerometer. This embodiment, combined with the actual application environment of the device, proposes to couple multiple stresses such as temperature, vibration, shock, and electrical stress together to conduct accelerated life tests on MEMS accelerometers. Utilizing the principle that the failure mechanism of the accelerometer remains unchanged under normal stress and accelerated stress levels, the life assessment of the MEMS accelerometer can be realized, which can greatly shorten the time required for normal stress life tests. Specific Implementation Example 4:

[0116] This specification also provides an electronic device, see [link to documentation]. Figure 3 The electronic device is capable of implementing the details of the method described in the above embodiments and achieving the same effect. For example... Figure 3 As shown, the electronic device 300 includes: a processor 301, a transceiver 302, a memory 303, a user interface 304, and a bus interface, wherein:

[0117] In this embodiment of the specification, the electronic device 300 further includes: a computer program stored in the memory 303 and executable by the processor 301, the computer program being executed by the processor 301 to perform the following steps:

[0118] Based on the application environment and working conditions, the core stress is applied in steps, various performance parameters are monitored, the main failure modes and weak points are determined, and the core stress limit range is obtained; wherein the performance parameters include zero bias, scaling factor, nonlinearity, and frequency response;

[0119] Within the core stress limit range, a core stress combination test scheme is constructed, and based on the given reliability and confidence level, the number of test samples and the number of failures for constant accelerated life are determined, and constant accelerated life test is carried out on the MEMS accelerometer.

[0120] Based on constant acceleration life test data, the variation law of performance parameters with time was obtained, and the degradation amount of performance parameters was analyzed according to the performance parameter degradation model. Pseudo-life estimates of the performance parameters of multiple MEMS accelerometers under different stress levels were obtained.

[0121] Based on the pseudo-life estimates of the performance parameters of multiple MEMS accelerometers under different stress levels, and according to the core stress of the MEMS accelerometer, a multi-stress accelerated life evaluation model is established between the MEMS accelerometer and temperature, shock, electrical stress and operating time.

[0122] exist Figure 3 In this document, the bus framework may include any number of interconnected buses and bridges, specifically linking various circuits of one or more processors represented by processor 401 and memory represented by memory 303 together. The bus framework may also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be further described here. The bus interface provides an interface. Transceiver 402 may be multiple elements, including transmitters and receivers, providing a unit for communicating with various other devices over a transmission medium. For different user equipment, the user interface 304 may also be an interface capable of connecting external or internal devices, including but not limited to keypads, displays, speakers, microphones, joysticks, etc.

[0123] The processor 301 has an amplitude management bus architecture and normal processing capabilities. The memory 303 can store data used by the processor 301 during operation. Optionally, when a computer program is executed by the processor 301, it can also perform the following steps:

[0124] Optionally, based on a preset reinforcement test scheme, the core stress is applied in steps, and the zero bias, scaling factor, nonlinearity, and frequency response performance parameters are monitored to determine the main failure modes and weak points, thereby obtaining the core stress limit range, including:

[0125] Based on the application environment and working conditions, and based on the enhanced test scheme, stepping high temperature test, stepping electric stress test, and stepping impact test are adopted. After the test, performance testing and comparison and failure analysis are performed.

[0126] Based on the results of the reinforcement test, the core stress affecting the MEMS accelerometer was identified, and the limit range of the core stress and the main failure modes were obtained.

[0127] Optionally, the core stress includes: temperature, impact, and electrical stress.

[0128] Optionally, the core stress combination test scheme includes: constant accelerated testing under the same temperature stress but with different impact and electrical stresses;

[0129] Multiple schemes for constant accelerated testing under the same impact stress but different temperatures and electrical stresses, constant accelerated testing under the same electrical stress but different temperatures and impact stresses, and constant accelerated testing under different electrical stresses but the same temperature and impact stresses.

[0130] Optionally, for the same stress level, the minimum pseudo-lifetime value of the MEMS accelerometer can be taken.

[0131] Optionally, the performance parameter degradation model includes: a linear parametric regression model, specifically:

[0132] f(t)=f(0)+bt+δ (1)

[0133] Where f(t) is the test value of the performance parameter, f(0) is the initial value of the performance parameter, b is the degenerate model parameter, and δ is the model error.

[0134] Optionally, the multi-stress accelerated life evaluation model includes:

[0135]

[0136] Where t is the average lifespan, and f(F) is the relative impact force function. g(I) is the inverse power-law model function, g(I) = C·I -D Where A, B, C, D, E, and G are constants, and k is the Boltzmann constant.

[0137] Optionally, the main failure modes include degradation of key parameters such as zero bias, scaling factor, nonlinearity, and frequency response; wire bonding failure; pull-in short circuit; fracture of sensitive structure; and mechanical defects such as cracks and degradation of sealing performance.

[0138] The application environment includes: temperature, humidity, electrical stress, vibration and shock, and magnetic field.

[0139] In summary, this embodiment applies core stress in steps, monitors various performance parameters, and obtains the core stress limit range. Within the core stress limit range, a core stress combination test scheme is constructed to conduct constant accelerated life tests on the MEMS accelerometer. Based on the constant accelerated life test data and performance parameter degradation model, the degradation of performance parameters is analyzed to obtain pseudo-life estimates for multiple performance parameters under different stress levels. Based on the pseudo-life estimates of multiple performance parameters under different stress levels, a multi-stress accelerated life evaluation model is established for the MEMS accelerometer in relation to temperature, shock, electrical stress, and operating time, according to the core stress of the MEMS accelerometer. This embodiment, combined with the actual application environment of the device, proposes to couple multiple stresses such as temperature, vibration, shock, and electrical stress together to conduct accelerated life tests on MEMS accelerometers. Utilizing the principle that the failure mechanism of the accelerometer remains unchanged under normal stress and accelerated stress levels, the life assessment of the MEMS accelerometer can be realized, which can greatly shorten the time required for normal stress life tests.

[0140] The above description is merely a preferred embodiment of this specification and is not intended to limit this specification. Various modifications and variations can be made to this specification by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this specification should be included within the scope of protection of this specification.

Claims

1. A MEMS accelerometer lifetime assessment method, characterized by, The application comprises the following steps: According to the application environment and working conditions, the core stress is step by step applied, the performance parameters are monitored, the main failure mode and weak link are determined, and the core stress limit range is obtained; The performance parameters include zero offset, scale factor, nonlinearity, and frequency response; Within the core stress limit range, a core stress combination test scheme is constructed, and the test sample number and failure number of the constant acceleration life test are determined according to the given reliability and confidence, and the MEMS accelerometer is subjected to the constant acceleration life test; According to the constant acceleration life test data, the variation law of the performance parameters with time is obtained, the performance parameter degradation amount is analyzed according to the performance parameter degradation model, and the pseudo-life estimation values of the performance parameters of multiple MEMS accelerometers under different stress levels are obtained; Based on the pseudo-life estimation values of the performance parameters of the multiple MEMS accelerometers under different stress levels, a multi-stress acceleration life evaluation model of the MEMS accelerometer and temperature, impact, electric stress, and working time is established according to the core stress of the MEMS accelerometer.

2. The method of claim 1, wherein, The application comprises the following steps: According to the application environment and working conditions, the core stress is step by step applied, the performance parameters are monitored, the main failure mode and weak link are determined, and the core stress limit range is obtained; According to the application environment and working conditions, the core stress is step by step applied, the performance parameters are monitored, the main failure mode and weak link are determined, and the core stress limit range is obtained; 3. The method according to claim 1 or 2, characterized in that, The core stress comprises temperature, impact, and electric stress.

4. The method of claim 3, wherein, The core stress combination test scheme comprises constant acceleration tests under the same temperature stress, different impacts, and electric stresses; constant acceleration tests under the same impact stress, different temperatures, and electric stresses; constant acceleration tests under the same electric stress, different temperatures, and impact stresses; and constant acceleration tests under different electric stresses, the same temperature, and impact stresses.

5. The method of claim 4, wherein, For the same stress level, the minimum pseudo-life value of the MEMS accelerometer is taken.

6. The method of claim 1, wherein, The multi-stress acceleration life evaluation model comprises: where t is the average lifetime, f(F) is the relative impact force function, g(I) is the inverse power law model function, g(I) = C - I -D ; where A, B, C, D, E, G are undetermined constants, k is the Boltzmann constant, the parameter T represents the temperature stress, F represents the impact force, and I represents the electric stress.

7. The method of claim 6, wherein, The main failure mode comprises zero offset, scale factor, nonlinearity, frequency response key parameter degradation, wire bonding failure, suction short circuit, sensitive structure fracture, and mechanical defects such as cracks and seal performance degradation. The application environment comprises temperature, humidity, electric stress, vibration impact, and magnetic field.

8. A MEMS accelerometer lifetime evaluation apparatus for implementing the method of any one of claims 1 to 7, characterized in that, The application comprises the following steps: The core stress limit range determination module, the constant acceleration life test module, the pseudo-life estimation value determination module, and the multi-stress acceleration life evaluation model construction module are used to perform the following steps: The core stress limit range determination module is used to perform the following steps: according to the application environment and working conditions, the core stress is step by step applied, the performance parameters are monitored, the main failure mode and weak link are determined, and the core stress limit range is obtained; wherein the performance parameters include zero offset, scale factor, nonlinearity, and frequency response. The constant acceleration life test module is used for constructing a core stress combination test scheme within a core stress limit range, determining a test sample number and a failure number of the constant acceleration life test according to a given reliability and confidence, and performing the constant acceleration life test on the MEMS accelerometer. The pseudo-life estimation value determination module is used for obtaining a variation law of the performance parameters with time according to the constant acceleration life test data, analyzing a performance parameter degradation amount according to a performance parameter degradation model, and obtaining pseudo-life estimation values of the multiple performance parameters under different stress levels. The multi-stress acceleration life evaluation model construction module is used for establishing a multi-stress acceleration life evaluation model between the MEMS accelerometer and temperature, impact, electric stress and working time according to the core stress of the MEMS accelerometer based on the pseudo-life estimation values of the multiple performance parameters under different stress levels.

9. An electronic device, comprising: Comprise: a communication interface, a processor and a memory; The processor invokes program instructions in the memory, and is used for performing the following actions: According to an application environment and working conditions, the core stress is step by step applied, each performance parameter is monitored, a main failure mode and a weak link are determined, and a core stress limit range is obtained; wherein the performance parameters include zero offset, scale factor, nonlinearity and frequency response; Within the core stress limit range, a core stress combination test scheme is constructed, and a test sample number and a failure number of the constant acceleration life test are determined according to a given reliability and confidence, and the constant acceleration life test is performed on the MEMS accelerometer; According to the constant acceleration life test data, a variation law of the performance parameters with time is obtained, a performance parameter degradation amount is analyzed according to a performance parameter degradation model, and pseudo-life estimation values of the multiple performance parameters under different stress levels are obtained; Based on the pseudo-life estimation values of the multiple performance parameters under different stress levels, a multi-stress acceleration life evaluation model between the MEMS accelerometer and temperature, impact, electric stress and working time is established according to the core stress of the MEMS accelerometer.

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