A full-parameter integrated test method for high-g value passive MEMS impact switch

Abstract

The application discloses a full-parameter integrated test method of a high-g-value passive MEMS impact switch, and comprises the following steps: appearance and electrical pretreatment are performed on a MEMS impact switch to be tested; the clamped sample is placed on a high-precision centrifuge; the sample is installed on a high-g-value impact table with a tool; a standard half-sine impact pulse is applied along the sensitive axis direction; an acceleration signal of the impact table and a conduction voltage signal of the switch are synchronously collected through a high-speed synchronous collection system; an overload impact pulse with an output of 30000g is set for the impact table; the sample is subjected to continuous cycle impact; data is arranged and analyzed; the eligibility of a single sample and batch samples is determined according to preset qualified indexes; and a complete test report is generated. The application realizes high-precision, standardized and one-stop test of the acceleration threshold, dynamic triggering characteristics, response time, holding time, anti-overload capacity and cycle life of the switch, and is suitable for actual application working conditions of high-g-value and narrow pulse width.

Description

Technical Field

[0001] This invention relates to the field of inertial device testing technology, specifically to a comprehensive integrated testing method for high-g passive MEMS impact switches. Background Technology

[0002] MEMS impact switches are passive inertial sensing devices fabricated using microelectromechanical systems (MEMS) technology. They rely on external impact acceleration to drive an internal movable structure, enabling acceleration sensing and on / off state transitions. These switches feature low standby power consumption, small size, and strong resistance to harsh environments, and are widely used in aerospace telemetry and control, weaponry, automotive safety, and industrial equipment condition monitoring. In practical engineering applications, the inertial characteristics of MEMS impact switches, such as acceleration threshold, response time, hold time, trigger consistency, overload resistance, and cycle life, directly determine the safety and reliability of the system.

[0003] In existing technologies, testing methods for MEMS switches mostly focus on radio frequency (RF) MEMS switches. For example, the "Self-Correcting RF MEMS Switch Reliability Testing System and Method" published in Chinese Invention Patent Publication No. CN118011199A on May 10, 2024, is designed for RF MEMS switches. It provides a mixed drive waveform and RF signal through a signal input module, and combines a signal monitoring and acquisition feedback module to monitor the pull-in voltage, contact resistance, and RF signal transmission characteristics of the RF MEMS switch. It also corrects the charging effect by adjusting the duty cycle of the drive waveform. Its core solution is to address the RF performance and charging effect issues of RF-type active drive MEMS switches. The test parameters focus on electrical performance and RF characteristics, and the test environment is a static environment with controllable room temperature. It cannot be adapted to the high g-value and narrow pulse width impact triggering characteristics of passive inertial MEMS impact switches, nor can it test core inertial parameters such as acceleration threshold, impact response time, and overload resistance.

[0004] Therefore, it is necessary to develop a dedicated testing method for MEMS impact switches that is adapted to high g-values, narrow pulse widths, and passive triggering characteristics. This method would solve the incompatibility issues of existing MEMS switch testing technologies and the problems of low accuracy, fragmented processes, and poor efficiency of traditional inertial impact switch testing methods, thereby achieving integrated, high-precision, and standardized testing of the core parameters of inertial impact switches. Summary of the Invention

[0005] The present invention proposes a fully integrated testing method for high-g passive MEMS impact switches, which can at least solve one of the technical problems in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A comprehensive, integrated testing method for high-g passive MEMS impact switches includes the following steps: S1: Perform appearance and electrical pretreatment on the MEMS impact switch to be tested, rigidly fix the sample to a special test fixture, and complete the electrical connection between the switch and the continuity monitoring circuit and the high-speed synchronous acquisition system to complete the preparation before testing; S2: Place the clamped sample in a high-precision centrifuge, apply a continuously adjustable centrifugal acceleration along the sensitive axis, and monitor the on / off status of the switch in real time; S3: Install the sample with the tooling onto the high g-value impact stage, apply a standard half-sine impact pulse along the sensitive axis, set the peak acceleration and pulse width according to the switch nominal parameters, apply 3 impacts, collect the switch on / off signal in real time, and statistically analyze the trigger success rate, false trigger rate and non-trigger rate. S4: The acceleration signal of the impact table and the conduction voltage signal of the switch are synchronously acquired through the high-speed synchronous acquisition system, and the contact resistance and conduction holding time after the switch is turned on are recorded at the same time. S5: Based on the nominal trigger threshold of the switch, set the impact table to output an overload impact pulse of 30000g, and apply 3 overload impacts in each of the three axes and six directions; after the impact is completed, check whether the switch has abnormalities such as false triggering, structural adhesion / breakage, or package damage, and at the same time retest the static trigger threshold of the switch to verify whether the parameters have drifted. S6: Set the impact stage to the impact level of the switch's nominal threshold and the pulse width to 0.1ms to 1ms, and continuously cyclically impact the sample for a total of 1000 cycles; after every 100 cycles, pause the test and check the switch's static trigger threshold and on-resistance, and record the parameter drift. S7: Organize and analyze the static threshold, response time, hold time, trigger consistency, overload resistance characteristics, and lifespan data obtained from the above tests. Based on the preset qualification indicators, complete the qualification judgment of single samples and batch samples, and generate a complete test report containing raw data, curves, and judgment results.

[0007] As a preferred embodiment of the integrated testing method for all parameters of the high-g passive MEMS impact switch described in this invention, in step S1, the coaxiality error between the switch sensitive axis and the acceleration loading direction is ensured to be ≤1° by using a positioning pin.

[0008] As a preferred embodiment of the integrated testing method for all parameters of the high-g passive MEMS impact switch described in this invention, step S2 specifically includes: Starting from 0g, the centrifuge was controlled to gradually increase the centrifugal acceleration in steps of ≤1g / step, and the acceleration value Gon at which the switch first stably turned on was recorded. Starting from an acceleration value higher than Gon, decrease the acceleration value Goff at which the switch first stably disconnects, and record the acceleration value Goff at which the switch first stably disconnects. The static trigger threshold is calculated using the formula Gs=(Gon+Goff) / 2, and the threshold hysteresis is calculated using the formula ΔG=Gon-Goff.

[0009] As a preferred embodiment of the integrated testing method for all parameters of the high-g passive MEMS impact switch described in this invention, in step S3, the switch on / off state of each impact is collected and recorded in real time by a high-speed synchronous acquisition system. The host computer calculates the trigger success rate in this direction based on the collected data: (number of effective triggers / total number of impacts) × 100%. If the trigger success rate in this direction is less than 100%, it is recorded as a triggering abnormality. If the switch is turned on without an impact, it is determined to be a false trigger.

[0010] As a preferred embodiment of the integrated testing method for all parameters of the high-g passive MEMS impact switch described in this invention, step S4 specifically includes: Sampling rate ≥ 10 MSPS, inter-channel synchronization error ≤ 50 ns; The starting time t1 is the moment when the acceleration signal reaches 90% of the nominal threshold, the ending time t2 is the moment when the switch output voltage jumps ≥90% of the rated value and remains stable on, and the ending time t3 is the moment when the switch output voltage jumps ≤10% of the rated value and remains stable off. The response time Δta = t2 - t1 and the holding time Δtb = t3 - t2 are calculated. The contact resistance after the switch is turned on is calculated using the sampling resistor of the conduction monitoring circuit.

[0011] in, It is the power supply voltage. It is the load resistor. It is the contact resistance during conduction. It is the voltage across the load resistor, and the holding time of the switch from being on to being off is recorded.

[0012] As a preferred embodiment of the integrated testing method for all parameters of the high-g passive MEMS impact switch described in this invention, in step S5, the static trigger threshold is retested. If the deviation between the retested value and the initial value is ≤ ±10%, the overload resistance is deemed qualified; otherwise, it is deemed unqualified.

[0013] As a preferred embodiment of the integrated testing method for all parameters of the high-g passive MEMS impact switch described in this invention, in step S6, if the threshold drift is > ±10% and the switch cannot be stably triggered, it is determined to be a switch failure, and the total number of cycles before the failure is recorded.

[0014] As a preferred embodiment of the integrated testing method for all parameters of the high-g passive MEMS impact switch described in this invention, step S7 involves a comprehensive judgment based on preset qualification criteria. ① The deviation between the static trigger threshold and the nominal value is ≤ ±10%; ② Response time ≥ 80% of impact pulse width; ③ Holding time ≤ 5% of impact pulse width; ④ No structural abnormalities or false triggering occurred after the overload impact, and the threshold drift was ≤±10%; ⑤ Parameter drift during life testing ≤ ±10%; If all of the above indicators are met, the sample is deemed qualified; if any one indicator is not met, the sample is deemed unqualified. The host computer generates a standardized test report containing sample information, test parameters, raw data, and judgment conclusions based on the judgment results, which can be exported and printed.

[0015] The beneficial effects of this invention are: 1. A dedicated test system was designed for MEMS impulse switches with high g values, narrow pulse widths, and passive triggering. This system solved the technical problems of RF MEMS switch RF performance testing and the inability to adapt to the core parameter testing of inertial impulse switches, filling the technical gap in full parameter testing of passive inertial MEMS impulse switches. 2. The accuracy of response time measurement is greatly improved. A high-speed synchronous acquisition system with a sampling rate of ≥10MSPS is adopted, the channel synchronization error is ≤50ns, and the response time measurement resolution is ≤100ns. It can accurately capture the microsecond-level switching of the conduction signal and solve the problem of inaccurate signal measurement under high g value and narrow pulse width impact. 3. A standardized, multi-dimensional testing process has been established, covering six directions across three axes (X, Y, and Z). It enables one-stop testing of all parameters, including acceleration threshold, dynamic triggering characteristics, response time, hold time, overload resistance, and cycle life. The tests are highly reproducible, and test data from different devices and laboratories can be directly compared, thus solving the shortcomings of traditional methods such as inconsistent processes and poor data consistency. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall architecture of the test system for the integrated testing method of the high-g value passive MEMS impact switch of the present invention.

[0017] Figure 2 This is a timing comparison diagram of the dynamic impact signal and the switch conduction signal for the integrated testing method of the high-g passive MEMS impact switch of the present invention.

[0018] Figure 3 This is a schematic diagram of the static acceleration threshold centrifugation test process for the integrated full-parameter test method of the high-g passive MEMS impact switch of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0020] like Figures 1-3 As shown, a comprehensive integrated testing method for high-g passive MEMS impact switches includes the following steps: S1. Sample pretreatment and tooling clamping, combined Figure 1 As shown: The high-g passive MEMS impact switch under test was left to stand at room temperature (25℃±2℃) and normal pressure for ≥2 hours. Microscopic inspection revealed no cracks or damage to the package. The initial on / off state was confirmed to be normal by the continuity monitoring circuit. The sample was then placed in the positioning slot of a six-way adjustable special fixture and rigidly fixed with locking screws. The fixture angle was adjusted to ensure that the coaxiality error between the switch's sensitive axis and the acceleration loading direction was ≤1°. The two pins of the switch were connected to the output of the continuity monitoring circuit. The signal output of the continuity monitoring circuit and the signal output of the standard accelerometer were respectively connected to the two acquisition channels of the high-speed synchronous acquisition system. The high-speed synchronous acquisition system established communication with the host computer control system, completing all hardware connections and debugging before testing. S2, Static acceleration threshold centrifugation test, combined with Figure 1 , Figure 3 As shown: The fixture holding the sample is fixed in the turntable of the high-precision centrifuge, ensuring that the sensitive axis of the switch is completely aligned with the radial centrifugal acceleration direction of the centrifuge. The acceleration loading parameters of the centrifuge are set via the host computer, starting from 0g and increasing in increments of 1g / step, with each step pausing for ≥1s to ensure signal stability. The high-speed synchronous acquisition system collects the on / off signals of the switch in real time and uploads them to the host computer. When the switch first shows stable conduction and remains stable for ≥1s, the host computer automatically records the acceleration value Gon. Subsequently, the centrifuge is set to decrease in increments of 1g / step, with each step also pausing for ≥1s. When the switch first shows stable deceleration and remains stable for ≥1s, the host computer automatically records the acceleration value Goff. The host computer automatically calculates the static trigger threshold Gs=(Gon+Goff) / 2 and the threshold hysteresis ΔG=Gon-Goff according to the built-in formula and stores the data in the database. S3, Dynamic Impact Triggering Characteristic Test, combined with Figure 1 : The sample was removed from the centrifuge along with the fixture and installed on the stage of the high-g impact stage. Using the six-way adjustment function of the fixture, the sensitive axis of the switch was aligned with the acceleration loading direction of the impact stage and locked. The output parameters of the impact stage were set via the host computer: the impact waveform was a half-sine wave, and the peak acceleration and pulse width were set according to the switch's nominal parameters. Three impacts were applied independently in this direction, with an interval ≥10s. The high-speed synchronous acquisition system collected and recorded the switch's on / off state for each impact in real time. Based on the collected data, the host computer calculated the trigger success rate in this direction as (number of effective triggers / total number of impacts) × 100%. If the trigger success rate in this direction was <100%, it was recorded as a triggering anomaly. If the switch was conducting without an impact, it was determined to be a false trigger. S4, Response Time and Conductivity Test, combined with Figure 1 , Figure 2 : While maintaining the sample in the clamped state on the impact stage, the impact stage and high-speed synchronous acquisition system are simultaneously started by the host computer. The impact stage outputs a half-sine impact pulse of the nominal threshold, and the high-speed synchronous acquisition system synchronously acquires the acceleration signal from the standard accelerometer and the conduction voltage signal from the switch at a sampling rate of 10 MSPS. The host computer performs waveform processing on the acquired signals, defining the moment when the acceleration signal rises to 90% of the nominal threshold as t1, the moment when the switch conduction voltage jumps ≥90% of the rated value and stabilizes as t2, and the moment when the switch output voltage jumps ≤10% of the rated value and remains stably off as the termination moment t3. The response time Δta = t2 - t1 and the holding time Δtb = t3 - t2 are automatically calculated. Simultaneously, the contact resistance after the switch is turned on is calculated using the sampling resistor of the conduction monitoring circuit.

[0021] in, It is the power supply voltage. It is the load resistor. It is the contact resistance during conduction. It is the voltage across the load resistor, and the holding time of the switch from being on to being off is recorded; S5, Overload resistance verification, combined with Figure 1 : The peak acceleration of the impact stage is set to 30000g by the host computer, and the pulse width is maintained at ≥10μs. Three overload impacts are applied in each of the six directions along the three axes of X, Y, and Z, with an impact interval of ≥20s. After the overload impact is completed, the switch is first visually inspected to confirm that there is no damage to the package or structural breakage. Then, the continuity monitoring circuit is used to check that the switch is not normally stuck and conducting (no false triggering). Finally, the sample is reinstalled in the centrifuge, and the static trigger threshold is retested. If the deviation between the retest value and the initial value is ≤±10%, the overload resistance is deemed qualified; otherwise, it is deemed unqualified. S6, Cycle life and stability testing, combined with Figure 1 : The peak acceleration of the impact stage is set to the nominal threshold of the switch, the pulse width is set to 0.1ms to 1ms, and the impact time interval is 10s. The sample is subjected to continuous cyclic impacts, with a total number of cycles preset to 1000. The host computer sets the test nodes. After every 100 cycles, the impact stage automatically pauses, the centrifuge automatically performs a static threshold retest on the sample, and the continuity monitoring circuit synchronously detects the continuity resistance. The host computer records the threshold and resistance values ​​of each retest and plots the parameter drift curve. If the switch threshold drift is >±10% or cannot be stably triggered during the test, the host computer automatically terminates the test and records the total number of cycles at this time as the failure life of the switch. If the switch threshold drift is ≤±10% after 1000 cycles, the life test is deemed qualified. S7. Data Processing and Compliance Determination: The host computer organizes the raw data, waveforms, and parameter calculation results from all the above test stages, and makes a comprehensive judgment based on the preset pass / fail criteria: ① The deviation between the static trigger threshold and the nominal value is ≤ ±10%; ② Response time ≥ 80% of impact pulse width; ③ Holding time ≤ 5% of impact pulse width; ④ No structural abnormalities or false triggering occurred after the overload impact, and the threshold drift was ≤±10%; ⑤ Parameter drift during life testing ≤ ±10%; If all of the above indicators are met, the sample is deemed qualified; if any one indicator is not met, the sample is deemed unqualified. The host computer generates a standardized test report containing sample information, test parameters, raw data, and judgment conclusions based on the judgment results, which can be exported and printed.

[0022] In addition, the dedicated testing system upon which the testing method of this invention relies includes: a host computer control system for test process control, data processing, and report generation; a high-precision centrifuge with acceleration accuracy ≤0.1g, centrifugal acceleration adjustment range of 0~10000g, and clamping coaxiality error ≤1°, used for static threshold testing; a high-g impact stage capable of outputting half-sine wave impact pulses, peak acceleration of 5g~50000g, pulse width of 0.05ms~10ms, supporting X, Y, Z three-axis six-direction impacts, conforming to GB / T2423.5 standard; and a high-speed synchronous acquisition system. The system features a sampling rate ≥10MSPS, analog bandwidth ≥1MHz, and inter-channel synchronization error ≤50ns. It includes at least two acquisition channels to acquire acceleration and conduction signals respectively. The conduction monitoring circuit is powered by a constant voltage source (3.3V / 5V) and connected in series with a high-precision sampling resistor. The on / off state of the switch is determined by voltage fluctuations. A standard ICP accelerometer with an accuracy of ±0.1%FS is used for calibrating the acceleration signal of the impact stage. A six-way adjustable special tooling with a rigid aluminum structure, featuring a positioning pin and locking device, ensures that the coaxiality error between the sample's sensitive axis and the loading direction is ≤1°.

[0023] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0024] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0025] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A comprehensive integrated testing method for all parameters of a high-g passive MEMS impact switch, characterized in that, Includes the following steps: S1: Perform appearance and electrical pretreatment on the MEMS impact switch to be tested, rigidly fix the sample to a special test fixture, and complete the electrical connection between the switch and the continuity monitoring circuit and the high-speed synchronous acquisition system to complete the preparation before testing; S2: Place the clamped sample in a high-precision centrifuge, apply a continuously adjustable centrifugal acceleration along the sensitive axis, and monitor the on / off status of the switch in real time; S3: Install the sample with the tooling onto the high g-value impact stage, apply a standard half-sine impact pulse along the sensitive axis, set the peak acceleration and pulse width according to the switch nominal parameters, apply 3 impacts, collect the switch on / off signal in real time, and statistically analyze the trigger success rate, false trigger rate and non-trigger rate. S4: The acceleration signal of the impact table and the conduction voltage signal of the switch are synchronously acquired through the high-speed synchronous acquisition system, and the contact resistance and conduction holding time after the switch is turned on are recorded at the same time. S5: Based on the nominal trigger threshold of the switch, set the impact table to output an overload impact pulse of 30000g, and apply 3 overload impacts in each of the three axes and six directions; after the impact is completed, check whether the switch has abnormalities such as false triggering, structural adhesion / breakage, or package damage, and at the same time retest the static trigger threshold of the switch to verify whether the parameters have drifted. S6: Set the impact stage to the impact level of the switch's nominal threshold and the pulse width to 0.1ms to 1ms, and continuously cyclically impact the sample for a total of 1000 cycles; after every 100 cycles, pause the test and check the switch's static trigger threshold and on-resistance, and record the parameter drift. S7: Organize and analyze the static threshold, response time, hold time, trigger consistency, overload resistance characteristics, and lifespan data obtained from the above tests. Based on the preset qualification indicators, complete the qualification judgment of single samples and batch samples, and generate a complete test report containing raw data, curves, and judgment results.

2. The integrated testing method for all parameters of a high-g passive MEMS impact switch according to claim 1, characterized in that: In step S1, the coaxiality error between the switch sensitive axis and the acceleration loading direction is ensured to be ≤1° by using the positioning pin.

3. The integrated testing method for all parameters of a high-g passive MEMS impact switch according to claim 1, characterized in that: Step S2 specifically includes: Starting from 0g, the centrifuge was controlled to gradually increase the centrifugal acceleration in steps of ≤1g / step, and the acceleration value Gon at which the switch first stably turned on was recorded. Starting from an acceleration value higher than Gon, decrease the acceleration value Goff at which the switch first stably disconnects, and record the acceleration value Goff at which the switch first stably disconnects. The static trigger threshold is calculated using the formula Gs=(Gon+Goff) / 2, and the threshold hysteresis is calculated using the formula ΔG=Gon-Goff.

4. The integrated testing method for all parameters of a high-g passive MEMS impact switch according to claim 1, characterized in that: In step S3, the on / off state of the switch for each impact is collected and recorded in real time by a high-speed synchronous acquisition system. The host computer calculates the trigger success rate in this direction based on the collected data: (number of effective triggers / total number of impacts) × 100%. If the trigger success rate in this direction is less than 100%, it is recorded as a triggering abnormality. If the switch is turned on without an impact, it is determined to be a false trigger.

5. The integrated testing method for all parameters of a high-g passive MEMS impact switch according to claim 1, characterized in that: Step S4 specifically includes: Sampling rate ≥ 10 MSPS, inter-channel synchronization error ≤ 50 ns; The starting time t1 is the moment when the acceleration signal reaches 90% of the nominal threshold, the ending time t2 is the moment when the switch output voltage jumps ≥90% of the rated value and remains stable on, and the ending time t3 is the moment when the switch output voltage jumps ≤10% of the rated value and remains stable off. The response time Δta = t2 - t1 and the holding time Δtb = t3 - t2 are calculated. The contact resistance after the switch is turned on is calculated using the sampling resistor of the conduction monitoring circuit. in, It is the power supply voltage. It is the load resistor. It is the contact resistance during conduction. It is the voltage across the load resistor, and the holding time of the switch from being on to being off is recorded.

6. The integrated testing method for all parameters of a high-g passive MEMS impact switch according to claim 1, characterized in that: In step S5, the static trigger threshold is retested. If the deviation between the retested value and the initial value is ≤ ±10%, the overload resistance is deemed qualified; otherwise, it is deemed unqualified.

7. The integrated testing method for all parameters of a high-g passive MEMS impact switch according to claim 1, characterized in that: If the threshold drift is greater than ±10% in step S6 and the switch cannot be triggered stably, it is determined to be a switch failure, and the total number of cycles before the failure is recorded.

8. The integrated testing method for all parameters of a high-g passive MEMS impact switch according to claim 1, characterized in that: In step S7, a comprehensive judgment is made based on the preset pass / fail criteria: ① The deviation between the static trigger threshold and the nominal value is ≤ ±10%; ② Response time ≥ 80% of impact pulse width; ③ Holding time ≤ 5% of impact pulse width; ④ No structural abnormalities or false triggering occurred after the overload impact, and the threshold drift was ≤±10%; ⑤ Parameter drift during life testing ≤ ±10%; If all of the above indicators are met, the sample is deemed qualified; if any one indicator is not met, the sample is deemed unqualified. The host computer generates a standardized test report containing sample information, test parameters, raw data, and judgment conclusions based on the judgment results, which can be exported and printed.

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