A test system for piezoelectric actuators

Abstract

The application provides a kind of piezoelectric actuator test system, comprising: data acquisition card includes signal port and control port;High voltage drive circuit board is connected with the output end of signal port;Capacitance measurement circuit board is bidirectionally connected with signal port, and capacitance measurement circuit board is configured to receive the second voltage signal sent by signal port and is converted into capacitance detection signal;Signal switching circuit board is bidirectionally connected with control port and piezoelectric actuator respectively, and signal switching circuit board includes high voltage signal channel and capacitance detection channel, high voltage signal channel is connected with the output end of high voltage drive circuit board and piezoelectric actuator respectively, capacitance detection channel is bidirectionally connected with high voltage signal channel and piezoelectric actuator, and signal switching circuit board is configured to control the switch state of high voltage signal channel and capacitance detection channel based on the control signal of control port.The application can detect the internal small lattice defects of piezoelectric actuator, improve test efficiency and test accuracy.

Description

Technical Field

[0001] This application belongs to the field of semiconductor integrated circuit technology, and in particular relates to a test system and method for piezoelectric actuators. Background Technology

[0002] MEMS (Micro Electro-Mechanical System) galvanometers are semiconductor actuators that operate based on the inverse piezoelectric effect. The core component is the piezoelectric material grown on the MEMS cantilever beam. During semiconductor manufacturing, the piezoelectric material (piezoelectric actuator) is susceptible to lattice defects due to the influence of polarization voltage, polarization frequency, wafer substrate, and piezoelectric target. These lattice defects, when exposed to high external voltages, can lead to short circuits. Early detection of lattice defects in the piezoelectric material (especially on the wafer) can effectively reduce labor and material waste during packaging, improving yield. Therefore, timely detection of piezoelectric material lattice defects, particularly on the wafer, is crucial.

[0003] In related technologies, lattice anomalies are typically identified by detecting the capacitance value of piezoelectric materials and analyzing abnormal changes in capacitance. This method is simple, easy to implement, and has relatively high detection efficiency. However, some lattice defects in piezoelectric materials are very subtle and do not show obvious changes in capacitance, making it easy to miss detections.

[0004] Therefore, it is essential to provide an effective solution to the problem of the difficulty in detecting tiny lattice defects inside piezoelectric materials. Utility Model Content

[0005] This application discloses a testing system for piezoelectric actuators, which can detect tiny lattice defects inside piezoelectric materials, thereby improving testing efficiency and accuracy.

[0006] Other objectives and advantages of this application can be further understood from the technical features disclosed herein.

[0007] To achieve one or more of the above objectives or other objectives, in a first aspect, this application provides a testing system for a piezoelectric actuator, comprising: Data acquisition card, including signal ports and control ports; The high-voltage drive circuit board is connected to the output terminal of the signal port. The capacitance measurement circuit board is bidirectionally connected to the signal port. The capacitance measurement circuit board is configured to receive the second voltage signal sent by the signal port and convert it into a capacitance detection signal. The signal switching circuit board is bidirectionally connected to the control port and the piezoelectric actuator. The signal switching circuit board includes a high-voltage signal channel and a capacitance detection channel. The high-voltage signal channel is connected to the output terminal of the high-voltage drive circuit board and the piezoelectric actuator. The capacitance detection channel is bidirectionally connected to the high-voltage signal channel and the piezoelectric actuator. The signal switching circuit board is configured to control the switching state of the high-voltage signal channel and the capacitance detection channel based on the control signal of the control port.

[0008] Furthermore, the test system board includes a probe station, and the pins of the piezoelectric actuator are electrically connected to the probe station.

[0009] Furthermore, the high-voltage drive circuit board includes a positive high-voltage port and a negative high-voltage port, and the signal switching circuit board includes a positive high-voltage relay and a negative high-voltage relay. The positive high-voltage port is connected to the positive high-voltage relay, and the negative high-voltage port is connected to the negative high-voltage relay. The positive high-voltage relay and the negative high-voltage relay are respectively connected to the probe station.

[0010] Furthermore, the capacitance measurement circuit board includes a measurement relay, which is connected to the data acquisition card and the positive high voltage relay.

[0011] Furthermore, the probe station can connect to up to four piezoelectric actuators, and the switching circuit board includes up to four high-voltage signal channels and four capacitance measurement signal channels.

[0012] Furthermore, the testing system includes a host computer connected to a data acquisition card, which is configured to simultaneously control the testing of up to four piezoelectric actuators.

[0013] Furthermore, the signal port includes a digital-to-analog conversion port and an analog-to-digital conversion port. The digital-to-analog conversion port is connected to the input terminal of the signal switching circuit board and the input terminal of the high-voltage drive circuit board, respectively, and the analog-to-digital conversion port is connected to the output terminal of the signal switching circuit board.

[0014] Furthermore, a maximum of nine control ports and a maximum of four signal ports can be set.

[0015] Furthermore, the high-voltage drive circuit board, capacitance measurement circuit board, and signal switching circuit board are encapsulated in a metal shielding box.

[0016] The aforementioned piezoelectric actuator testing system utilizes a data acquisition card, a high-voltage drive circuit board, and a capacitance detection circuit board to form multiple signal channels. Combined with rapid switching via a signal switching circuit board, this enables precise and rapid testing of minute lattice defects within the piezoelectric actuator. Furthermore, the data acquisition card, in conjunction with a host computer, further enhances testing efficiency and accuracy, creating an automated cyclic testing system, particularly suitable for high-volume testing applications.

[0017] To make the above and other objects, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the specific embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a structural block diagram of a test system for a piezoelectric actuator according to this application.

[0020] Figure 2 This is a schematic diagram of the port connections of a test system for a piezoelectric actuator according to this application.

[0021] Figure 3 This is a circuit connection diagram of a test system for a piezoelectric actuator according to this application.

[0022] Figure 4 This is a schematic diagram of a multi-port circuit board for a test system of a piezoelectric actuator according to this application.

[0023] Figure 5 This is a schematic diagram illustrating the test procedure of a test system for a piezoelectric actuator according to this application. Detailed Implementation

[0024] The foregoing and other technical contents, features, and effects of this application will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate; this is merely a method of distinguishing objects with the same attributes in the embodiments of this application.

[0025] refer to Figures 1 to 4 This application provides a testing system for piezoelectric actuators, which is used to test the voltage surge capability of piezoelectric actuators, especially the high voltage surge capability of piezoelectric actuators of MEMS (Micro Electro-Mechanical System) mirrors. The system includes a data acquisition card, a high voltage drive circuit board, a capacitance measurement circuit board, and a signal switching circuit board.

[0026] Specifically, the data acquisition card includes a signal port and a control port. The signal port is used for transmitting and receiving analog signals, including sending a first voltage signal and a second voltage signal to transmit different signals. The signal port is also used to receive feedback signals from the capacitance measurement circuit board.

[0027] The high-voltage drive circuit board is connected to the output terminal of the signal port. The high-voltage drive circuit board is used to receive the second voltage signal output from the signal port and amplify it into a high-voltage impulse signal. For example, it can amplify a low-voltage (such as 0~5V) signal to a high-voltage (0~200V) signal, with an amplification factor of up to 40 times.

[0028] The capacitance measurement circuit board is bidirectionally connected to the signal port. It receives the second voltage signal output from the signal port and converts it into a capacitance detection signal. The circuit board also sends a feedback signal. After selecting the appropriate signal channel, the circuit board outputs the changed capacitance detection signal to the signal port, thus obtaining the capacitance value of the piezoelectric actuator.

[0029] The signal switching circuit board is bidirectionally connected to both the control port and the pins of the piezoelectric actuator. The circuit board includes a high-voltage signal channel and a capacitance detection channel. The high-voltage signal channel is connected to the output of the high-voltage drive circuit board, and the capacitance detection channel is bidirectionally connected to both the capacitance detection circuit board and the pins of the piezoelectric actuator. The signal switching circuit board is configured to control the switching states of the high-voltage signal channel and the capacitance detection channel based on the control signal from the control port, thereby switching between them. This allows for the time-division multiplexing of the high-voltage impact signal and the capacitance detection signal to the piezoelectric actuator, enabling a test of the piezoelectric actuator's ability to withstand high-voltage impacts. The data acquisition card is also used to acquire the capacitance value of the piezoelectric actuator before and after the capacitance detection signal switching. By calculating the current capacitance value of the piezoelectric actuator, the card analyzes whether the piezoelectric actuator is damaged under the high-voltage impact test, the degree of damage, and the stability of its withstand capability, thus comprehensively analyzing the piezoelectric actuator's ability to withstand high-voltage impacts.

[0030] In some embodiments, the testing system of this application further includes a probe station. The probe station can make electrical connections by contacting the piezoelectric actuator pins on the MEME mirror with fine probes. The probe station can connect to up to four piezoelectric actuators, and the signal switching circuit board includes up to four high-voltage signal channels and four capacitance detection channels to enable simultaneous testing of four piezoelectric actuators.

[0031] Further, refer to Figure 2 , Figure 3 and Figure 4The high-voltage drive circuit board includes a positive high-voltage port (HV_P_IN) and a negative high-voltage port (HV_N_IN). The signal switching circuit board includes positive high-voltage relays (HV_P1, HV_P2, HV_P3, HV_P4) and a negative high-voltage relay (HV_P1). The positive high-voltage port is connected to the positive high-voltage relay, and the negative high-voltage port is connected to the negative high-voltage relay. The positive and negative high-voltage relays are respectively connected to the probe station to form an equivalent capacitance arm. The capacitance measurement circuit board includes a measurement relay, which is connected between the data acquisition card and the positive high-voltage relay. The positive terminal of the piezoelectric actuator pin is connected to the positive high-voltage relay, and the negative terminal of the piezoelectric actuator pin is connected to the negative high-voltage relay. This allows for rapid switching between different signals and channels through the ports and relays, enabling rapid conversion between high-voltage impulse signals and capacitance detection signals, thus facilitating multiple tests of the piezoelectric actuator or simultaneous testing of multiple piezoelectric actuators.

[0032] refer to Figure 2 , Figure 3 and Figure 4 The control ports include multiple I / O ports (IO1~IO9) for connecting multiple relays on the signal switching circuit board and switching different signal channels by controlling different relays. Signal ports include digital-to-analog converter ports (ADC1~ADC4) and analog-to-digital converter ports (DAC1, DAC2). The digital-to-analog converter ports convert digital signals to analog signals, and the analog-to-digital converter ports convert analog signals to digital signals. Through individual conversion and control of multiple signal ports, and independent control of high voltage and pulse signals via multiple I / O ports, the safety and accuracy of multiple tests on multiple piezoelectric actuators (DUT1~DUT4) in high-voltage drive scenarios are improved. This allows for flexible application of positive and negative high voltage or impulse pulse signals while reliably isolating high voltage from the measurement circuit, enhancing the system's adaptability and stability. It provides efficient hardware support for testing the high voltage withstand capability and capacitance change characteristics of piezoelectric actuators.

[0033] Furthermore, the testing system of this application includes a host computer. The host computer is communicatively connected to the data acquisition card and includes computer software. The host computer is used to send control commands to the data acquisition card via control ports to switch relays on the control signal switching circuit board. The host computer is also used to send analog output or input commands to the data acquisition card, thereby controlling the generation and feedback of high-voltage impact signals and capacitance detection signals, and calculating the capacitance value of the piezoelectric actuator. Simultaneously, the host computer also includes a human-machine interface to facilitate operation by testing personnel.

[0034] Specifically, the host computer controls the time-division multiplexing of the data acquisition card, as well as the voltage magnitudes of the first and second voltage signals, thereby controlling the generation and feedback of the high-voltage impulse signal and the capacitance detection signal. The host computer determines the test results of the piezoelectric actuator based on the feedback signals. If the test result is unqualified, the host computer controls the piezoelectric actuator to be retested; if the test result is qualified, the host computer controls the testing of the piezoelectric actuator under test. Through this cyclical process, the host computer can simultaneously control the testing of up to four piezoelectric actuators, thus achieving accurate and rapid high-voltage impulse and capacitance measurements. Furthermore, the rapid switching of the host computer software reduces the testing time for individual piezoelectric actuators, and the testing process requires no manual intervention, making it particularly suitable for large-scale testing applications.

[0035] Optionally, the high-voltage drive circuit board, capacitance measurement circuit board, and signal switching circuit board are packaged in a metal shielded box and connected to the MEMS galvanometer via an external shielded wire, effectively reducing the risk of high-voltage leakage.

[0036] The control logic of the test system according to the embodiments of this application is described in detail below: The host computer controls the data acquisition card to output a first voltage signal. After being amplified 40 times by the high-voltage drive circuit board, such as a 3V voltage being amplified to a 120V high-voltage impulse signal, the high-voltage impulse signal reaches the front end of the signal switching circuit board. After the host computer sends a control command to the data acquisition card to select the control port, the switching circuit board executes the selection command and sends the high-voltage impulse signal to the piezoelectric actuator to realize the high-voltage impulse to the MEMS galvanometer piezoelectric actuator.

[0037] The host computer controls the data acquisition card to output a second voltage signal, which, after passing through the capacitance measurement circuit board, reaches the front end of the signal switching circuit board. After the host computer sends a control command to the data acquisition card's selection control port, the switching circuit board executes the selection command, sending the capacitance detection signal to the piezoelectric actuator. Simultaneously, the capacitance measurement board transmits the changed capacitance detection feedback signal to the analog input terminal of the data acquisition card. The host computer calculates the current capacitance value of the piezoelectric actuator by reading the change in the capacitance detection signal before and after selecting the piezoelectric actuator.

[0038] Control signal switching logic: The high-voltage impact signal and the capacitor detection signal are delivered to the MEMS mirror piezoelectric actuator in a time-division manner. That is, when the high-voltage impact signal reaches the MEMS mirror piezoelectric actuator, the capacitor detection signal is turned off, and vice versa.

[0039] The test process of the test system according to an embodiment of this application is described below. (Reference) Figure 5After the test begins, the probe station is initialized, and the automatic testing process for the piezoelectric actuator under test is initiated. The host computer acquires and judges the test results. If the test is passed, the test proceeds to the next piezoelectric actuator under test; if it fails, it checks whether it is the last piezoelectric actuator under test. If so, the test proceeds to the next piezoelectric actuator under test; if not, the piezoelectric actuator is retested. This process is repeated until the test of the last piezoelectric actuator under test is completed, at which point the test process ends.

[0040] It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from the principles thereof, and such improvements and modifications also fall within the scope of protection of the claims of this application. It should be understood that certain features of this disclosure described in the context of individual embodiments for clarity may also be provided in combination in a single embodiment. Conversely, various features of this disclosure described in the context of individual embodiments for clarity may also be provided individually or in any suitable combination or as part of any other described embodiment of this disclosure.

Claims

1. A testing system for a piezoelectric actuator, characterized in that, include: Data acquisition card, including signal ports and control ports; A high-voltage drive circuit board is connected to the output terminal of the signal port; A capacitance measurement circuit board is bidirectionally connected to the signal port, and the capacitance measurement circuit board is configured to receive a second voltage signal sent by the signal port and convert it into a capacitance detection signal. A signal switching circuit board is bidirectionally connected to the control port and the piezoelectric actuator. The signal switching circuit board includes a high-voltage signal channel and a capacitance detection channel. The high-voltage signal channel is connected to the output terminal of the high-voltage drive circuit board and the piezoelectric actuator. The capacitance detection channel is bidirectionally connected to the high-voltage signal channel and the piezoelectric actuator. The signal switching circuit board is configured to control the switching state of the high-voltage signal channel and the capacitance detection channel based on the control signal of the control port.

2. The testing system for a piezoelectric actuator according to claim 1, characterized in that, The test system board includes a probe station, and the pins of the piezoelectric actuator are electrically connected to the probe station.

3. The testing system for a piezoelectric actuator according to claim 2, characterized in that, The high-voltage drive circuit board includes a positive high-voltage port and a negative high-voltage port. The signal switching circuit board includes a positive high-voltage relay and a negative high-voltage relay. The positive high-voltage port is connected to the positive high-voltage relay, and the negative high-voltage port is connected to the negative high-voltage relay. The positive high-voltage relay and the negative high-voltage relay are respectively connected to the probe station.

4. The testing system for a piezoelectric actuator according to claim 3, characterized in that, The capacitance measurement circuit board includes a measurement relay, which is connected to the data acquisition card and the positive high voltage relay.

5. The testing system for a piezoelectric actuator according to claim 2, characterized in that, The probe station can connect to up to four piezoelectric actuators, and the switching circuit board includes up to four high-voltage signal channels and four capacitance measurement signal channels.

6. The testing system for a piezoelectric actuator according to claim 5, characterized in that, The testing system includes a host computer connected to the data acquisition card, which is configured to simultaneously control the testing of up to four piezoelectric actuators.

7. The testing system for a piezoelectric actuator according to claim 1, characterized in that, The signal port includes a digital-to-analog converter port and an analog-to-digital converter port. The digital-to-analog converter port is connected to the input terminal of the signal switching circuit board and the input terminal of the high-voltage drive circuit board, respectively. The analog-to-digital converter port is connected to the output terminal of the signal switching circuit board.

8. A testing system for a piezoelectric actuator according to claim 7, characterized in that, The system has a maximum of nine control ports and a maximum of four signal ports.

9. A testing system for a piezoelectric actuator according to claim 1, characterized in that, The high-voltage drive circuit board, the capacitance measurement circuit board, and the signal switching circuit board are encapsulated in a metal shielding box.

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