JP4822846B2 - Microstructure inspection apparatus, microstructure inspection method, and microstructure inspection program - Google Patents

Description

  The present invention relates to an inspection apparatus, an inspection method, and an inspection program for inspecting a microstructure such as a pressure sensor.

  In recent years, MEMS, which is a device in which various functions such as mechanical, electronic, optical, chemical, etc., are integrated, particularly using semiconductor microfabrication technology, has attracted attention. As MEMS technology that has been put into practical use, MEMS devices have been mounted on acceleration sensors, pressure sensors, air flow sensors, and the like, which are microsensors, for example, as various sensors for automobiles and medical use. In addition, by adopting this MEMS technology in the ink jet printer head, it is possible to increase the number of nozzles for ejecting ink and to eject ink accurately, thereby improving the image quality and increasing the printing speed. Furthermore, a micromirror array used in a reflective projector is also known as a general MEMS device.

  In the future, various sensors and actuators using MEMS technology will be developed, which will be applied to optical communication and mobile devices, computer peripherals, bioanalysis and portable power supplies. Is expected to be. Non-Patent Document 1 introduces various MEMS technologies on the agenda of the current state of technology and issues related to MEMS.

  On the other hand, with the development of MEMS devices, a method for appropriately inspecting the fine structure is also important because of the fine structure. Conventionally, the device has been rotated after packaging, or its characteristics have been evaluated using means such as vibration. However, it has failed to perform proper inspection at the initial stage such as the wafer state after microfabrication technology. By detecting this, the yield can be improved and the manufacturing cost can be further reduced.

In Patent Document 1, as an example, an inspection method is proposed in which a resistance value of an acceleration sensor that changes by blowing air is detected on an acceleration sensor formed on a wafer to determine the characteristics of the acceleration sensor. .
Japanese Patent Laid-Open No. 5-34371 Technical Survey Report No. 3 (issued by the Ministry of Economy, Trade and Industry, Industrial Technology and Environment Bureau, Technical Research Office, Manufacturing Industry Bureau, Industrial Machinery Division, March 28, 2003)

  In general, a structure having a minute movable part such as an acceleration sensor is a device whose response characteristics change even with a minute movement. Therefore, in order to evaluate the characteristics, it is necessary to perform a highly accurate inspection. Even when changes are made to the device by blowing air as shown in Patent Document 1, the characteristics of the acceleration sensor must be evaluated by making fine adjustments. It is extremely difficult to perform a high-precision inspection by spraying a mist, and even if it is performed, a complicated and expensive tester must be provided.

  The present invention has been made to solve the above-described problems, and provides an inspection method, an inspection apparatus, and an inspection program for accurately inspecting a structure having a minute movable part by a simple method. With the goal.

A microstructure inspection apparatus according to the present invention is a microstructure inspection apparatus for evaluating characteristics of at least one microstructure having a movable portion formed on a substrate, and the microstructure is tested during testing. A sound wave generating means for outputting a test sound wave to the body, a movement of the movable portion of the fine structure in response to the test sound wave outputted by the sound wave generating means, and detecting the microstructure based on a detection result Evaluation means for evaluating the characteristics of the sound wave, wherein the sound wave generation means includes a sound wave output means for outputting the test sound wave having a sound pressure corresponding to an input from the outside, and a test sound wave reaching the vicinity of the microstructure. And a sound pressure level of a test sound wave detected by the detection means and a sound pressure level of a predetermined test sound wave serving as a reference are compared, and a test output from the sound wave output means is detected. And a sound wave correcting means for correcting the bets waves, said evaluating means, wherein a micro structure and electrically isolated electrodes, and the electrostatic capacitance detection electrodes disposed to face the movable portion, wherein Capacitance detection for detecting the capacitance between the capacitance detection electrode and the movable portion of the microstructure, which is changed by the movement of the movable portion of the microstructure, from a terminal provided on the capacitance detection electrode side And a determination means for evaluating the characteristics of the microstructure based on a comparison between the changed capacitance detected by the capacitance detection means and the capacitance having a predetermined threshold value.

  For example, a plurality of the microstructures are arranged in an array on the substrate.

  For example, the evaluation unit detects the movement of the movable portion of the microstructure in response to the test sound wave output from the sound wave generation unit, and evaluates the characteristics of the microstructure based on the detection result.

  The sound wave generation means may include noise removal means for removing noise sound waves that reach the microstructure from outside.

  The noise removing unit is, for example, an anti-noise having the same frequency and sound pressure as the noise sound wave so as to cancel the noise sound wave based on the noise sound wave detected by the detecting unit before the test. Outputs sound waves.

  The anti-noise sound wave is output from the sound wave output unit together with the test sound wave, for example, at the time of the test.

  The evaluation means receives, for example, the detection result of the test sound wave detected by the detection means of the sound wave generation means, and outputs the result determined by the determination means.

  The microstructure is, for example, a pressure sensor, an acceleration sensor, an angular velocity sensor, or the like.

  Two or more movements of the movable portion of the microstructure may be detected at the same time, and two or more characteristics of the microstructure may be evaluated simultaneously based on the detection result. For example, it may be configured to simultaneously detect movements in two or more directions of the movable portion of the microstructure and to simultaneously evaluate characteristics in the two or more directions of the microstructure based on the detection result. .

  In the case where the microstructure has two or more movable parts and / or the case where the microstructure has two or more microstructures on the substrate, the movement of the two or more movable parts is simultaneously detected and detected. Based on the result, the characteristics of two or more movable parts of one or two or more of the microstructures may be simultaneously evaluated.

  When the two or more movable parts have different movable characteristics, the movement of the two or more movable parts is detected at the same time, and the characteristics of the two or more movable parts having the different movable characteristics based on the detected result May be evaluated simultaneously. The sound wave generating means outputs a synthetic wave including sound waves having two or more different frequencies as the test sound wave.

  For example, the sound wave generation unit outputs white noise as the test sound wave. It may be white noise in a predetermined frequency range.

  The evaluation unit may change at least one of a frequency and a sound pressure of a sound wave output from the sound wave generation unit, and evaluate a change in a signal accompanying a change in the sound wave.

The method for inspecting a microstructure according to the present invention includes a step of applying a test sound wave to at least one microstructure having a movable part formed on a substrate, and a step of applying the test sound wave to the movable part of the microstructure in response to the test sound wave. An evaluation step for detecting movement and evaluating the characteristics of the microstructure based on the detection result, and the step of providing the test sound wave comprises applying the test sound wave having a sound pressure according to an input from the outside. A sound wave output step for output, a detection step for detecting a test sound wave reaching the vicinity of the microstructure, a sound pressure level of the test sound wave detected by the detection step, and a sound pressure level of a predetermined test sound wave as a reference compare, and a the sound wave output wave correction step of correcting the test sound wave output by step, the evaluation step, the movable part of said micro structure A capacitance detection step for detecting a capacitance between the capacitance detection electrode disposed so as to face the movable portion of the microstructure, and the capacitance based on the capacitance detected in the capacitance detection step. And a determination step for evaluating characteristics of the microstructure.

A computer program according to the present invention has a step of controlling a computer to apply a test sound wave to at least one microstructure having a movable portion formed on a substrate, and faces the movable portion of the microstructure. An evaluation step of detecting a capacitance between the capacitance detection electrode installed in the manner described above and the movable portion of the microstructure, and evaluating the characteristics of the microstructure based on the detected capacitance; And a step of controlling to give the test sound wave includes a sound wave output step of outputting the test sound wave with a sound pressure according to an input from the outside, and the vicinity of the microstructure. A detection step for detecting a test sound wave that arrives, a sound pressure level of the test sound wave detected by the detection step, and a sound pressure of a predetermined test sound wave as a reference By comparing the bell, and a wave correction step of correcting the test sound wave output by the sound wave output step.

  According to the present invention, the movable portion of the microstructure is moved by air vibration using sound waves that are dense waves, and its characteristics are evaluated. For this reason, the microstructure can be inspected by a simple method.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a microstructure inspection system 1 according to the first embodiment of the present invention.

  Referring to FIG. 1, inspection system 1 according to the first embodiment of the present invention includes a tester (inspection apparatus) 5 and a substrate 10 on which a plurality of microstructure chips TP having minute movable parts are formed. .

  In this example, a multi-axis triaxial acceleration sensor will be described as an example of a microstructure to be tested.

  The tester 5 includes a speaker 2 that outputs sound waves that are dense waves, an input / output interface 15 for executing input / output data exchange between the outside and the inside of the tester, and a control unit 20 that controls the entire tester 5. In response to an instruction from the control unit 20 and a probe needle 4 used for contact with the test object, a measurement unit 25 for detecting a measurement value for evaluating the characteristic of the test object via the probe needle 4 A speaker control unit 30 for controlling the speaker 2, a microphone 3 for detecting external sound, and a signal adjustment unit for converting a sound wave detected by the microphone 3 into a voltage signal, further amplifying and outputting the voltage signal to the control unit 20 35. The microphone 3 can be arranged near the test object.

  Before describing the inspection method according to the present embodiment, a microstructure triaxial acceleration sensor as a test object will be described first.

  FIG. 2 is a view of the triaxial acceleration sensor as viewed from the top surface of the device.

  As shown in FIG. 2, the chip TP formed on the substrate 10 is provided with a plurality of pads PD around the chip TP. Metal wiring is provided to transmit an electrical signal to or from the pad. And in the center part, the four heavy cone AR which forms a clover type | mold is arrange | positioned.

  FIG. 3 is a schematic diagram of a three-axis acceleration sensor.

  Referring to FIG. 3, this three-axis acceleration sensor is a piezoresistive type, and a piezoresistive element as a detecting element is provided as a diffused resistor. This piezoresistive acceleration sensor can use an inexpensive IC process and is advantageous in miniaturization and cost reduction because the sensitivity does not decrease even if the resistance element as a detection element is formed small.

  As a specific configuration, the central heavy cone AR is supported by four beams BM. The beam BM is formed so as to be orthogonal to each other in the X-axis and Y-axis directions, and includes four piezoresistive elements per axis. Four piezoresistive elements for detecting the Z-axis direction are arranged beside the piezoresistive elements for detecting the X-axis direction. The top surface shape of the heavy cone AR forms a crowbar shape and is connected to the beam BM at the center. By adopting this crowbar type structure, the heavy cone AR can be enlarged and the beam length can be increased at the same time, so that a highly sensitive acceleration sensor can be realized even if it is small.

  The principle of operation of this piezoresistive three-axis acceleration sensor is that when the heavy cone receives acceleration (inertial force), the beam BM is deformed and acceleration is caused by a change in the resistance value of the piezoresistive element formed on the surface. It is a mechanism to detect. And this sensor output is set to the structure taken out from the output of the Wheatstone bridge mentioned later incorporated in each 3 axis | shaft independently.

  FIG. 4 is a conceptual diagram for explaining the deformation of the heavy cone and the beam when the acceleration in each axial direction is received.

  As shown in FIG. 4, the piezoresistive element has a property that its resistance value changes due to applied strain (piezoresistive effect). In the case of tensile strain, the resistance value increases, and in the case of compressive strain, The resistance value decreases. In this example, X-axis direction detecting piezoresistive elements Rx1 to Rx4, Y-axis direction detecting piezoresistive elements Ry1 to Ry4, and Z-axis direction detecting piezoresistive elements Rz1 to Rz4 are shown as examples.

  FIG. 5 is a circuit configuration diagram of a Wheatstone bridge provided for each axis.

  FIG. 5A is a circuit configuration diagram of the Wheatstone bridge in the X (Y) axis. The output voltages of the X axis and the Y axis are Vxout and Vyout, respectively.

  FIG. 5B is a circuit configuration diagram of the Wheatstone bridge in the Z-axis. The output voltage of the Z axis is Vzout.

  As described above, the resistance values of the four piezoresistive elements on each axis change due to the applied strain. Based on this change, each piezoresistive element outputs, for example, an output of a circuit formed by a Wheatstone bridge on the X axis and Y axis. The acceleration component of each axis is detected as an independently separated output voltage. Note that the above-described metal wiring and the like as shown in FIG. 2 are connected so that the above circuit is configured, and an output voltage for each axis is detected from a predetermined pad.

  Further, since this triaxial acceleration sensor can also detect the DC component of acceleration, it can also be used as an inclination angle sensor that detects gravitational acceleration, that is, an angular velocity sensor.

  FIG. 6 is a diagram for explaining the output response to the tilt angle of the triaxial acceleration sensor.

  As shown in FIG. 6, the sensor is rotated around the X, Y, and Z axes, and the bridge output of each of the X, Y, and Z axes is measured with a digital voltmeter. As a power source for the sensor, a low voltage power source + 5V is used. Each measurement point shown in FIG. 6 is plotted with a value obtained by arithmetically reducing the zero point offset of each axis output.

  FIG. 7 is a diagram for explaining the relationship between gravitational acceleration (input) and sensor output.

  The input / output relationship shown in FIG. 7 is obtained by calculating the gravitational acceleration component related to the X, Y, and Z axes from the cosine of the inclination angle of FIG. 6 and obtaining the relationship between the gravitational acceleration (input) and the sensor output. The linearity of the input / output is evaluated. That is, the relationship between acceleration and output voltage is almost linear.

  When the triaxial acceleration sensor (the weight body AR) is vibrated along the Z axis, for example, and the triaxial acceleration sensor rotates around the X axis or the Y axis (other than the Z axis), the weight body AR The power of Coriolis works. Since the direction and magnitude of the Coriolis force can be detected, the triaxial acceleration sensor can be used as an angular velocity sensor. The method of measuring the angular velocity with a three-axis acceleration sensor is described in detail in, for example, Nobumitsu Taniguchi, et al. “Micromachined 5-axis Motion Sensor with Electrostatic Drive and Capacitive Detection”, Technical Digest of the 18th Sensor Symposium, 2001. pp. 377-380.

  FIG. 8 is a diagram for explaining the frequency characteristics of the three-axis acceleration sensor.

  As shown in FIG. 8, the frequency characteristics of the sensor output for each of the X, Y, and Z axes are flat frequency characteristics up to about 200 Hz for all three axes, for example, 602 Hz for the X axis and 600 Hz for the Y axis. The Z axis resonates at 883 Hz.

  Referring to FIG. 1 again, the micro structure inspection method according to the embodiment of the present invention outputs micro waves based on the sound waves by outputting sound waves that are dense waves to the triaxial acceleration sensor that is the micro structure. In this method, the movement of the movable part of the structure is detected and its characteristics are evaluated.

  A microstructure inspection method according to the first embodiment of the present invention will be described with reference to the flowchart of FIG.

  With reference to FIG. 9, first, inspection (test) of the microstructure is started (step S0). Next, the probe needle 4 is brought into contact with the pad PD of the detection chip TP (step S1). Specifically, the probe needle 4 is brought into contact with a predetermined pad PD in order to detect the output voltage of the Wheatstone bridge circuit described in FIG. In the configuration of FIG. 1, a configuration using a single set of probe needles 4 is shown, but a configuration using a plurality of sets of probe needles is also possible. By using a plurality of sets of probe needles, a plurality of outputs from one chip TP and / or an output signal can be detected in parallel for a plurality of chips TP.

  Next, a test sound wave output from the speaker 2 is set (step S2a). Specifically, the control unit 20 receives input of external input data via the input / output interface 15. Then, the control unit 20 controls the speaker control unit 30 and instructs the speaker control unit 30 to output a test sound wave having a desired frequency and a desired sound pressure from the speaker 2 based on the input data. Next, a test sound wave is output from the speaker 2 to the detection chip TP (step S2b).

  Next, a test sound wave applied from the speaker 2 to the detection chip TP is detected using the microphone 3 (step S3). The test sound wave detected by the microphone 3 is converted and amplified into a voltage signal by the signal adjustment unit 35 and output to the control unit 20.

  Next, the control unit 20 analyzes and determines the voltage signal input from the signal adjustment unit 35, and determines whether or not a desired test sound wave has arrived (step S4).

  In step S4, when it determines with it being a desired test sound wave, the control part 20 progresses to the following step S5 and measures the characteristic value of a detection chip. Specifically, the characteristic value is measured by the measurement unit 25 based on the electrical signal transmitted through the probe needle 4 (step S5).

  Specifically, the movable part of the microstructure of the detection chip is moved by the arrival of the test sound wave that is a dense wave output from the speaker 2, that is, by air vibration. A change in the resistance value of the triaxial acceleration sensor, which is a microstructure that changes based on this movement, is measured based on an output voltage applied through the probe needle 4.

  On the other hand, if it is determined in step S4 that it is not the desired test sound wave, the process returns to step S2a again to reset the test sound wave. At that time, the control unit 20 instructs the speaker control unit 30 to correct the test sound wave to the speaker control unit 30. The speaker control unit 30 performs control to finely adjust the frequency and / or sound pressure so as to obtain a desired test sound wave in response to an instruction from the control unit 20 and output the desired test sound wave from the speaker 2. In this example, a method of detecting a test sound wave and correcting it to a desired test sound wave is described. However, when the desired test sound wave reaches the microstructure of the detection chip in advance, the test is particularly performed. It is also possible to employ a configuration in which a sound wave correcting means and a method for correcting the test sound wave are not provided. Specifically, the processes from step S2a to S4 are executed in advance before the test is started, and the speaker control unit 30 stores a corrected control value for outputting a desired test sound wave. Then, when testing the actual microstructure, the speaker control unit 30 controls the input to the speaker 2 with the recorded control value, thereby omitting the processes of steps S3 and S4 during the test. Is also possible.

Next, the control unit 20 determines whether or not the measured characteristic value, that is, measurement data is within an allowable range (step S6). If it is determined in step S6 that the value is within the allowable range, the data is passed (step S7), and data is output and stored (step S8). Then, the process proceeds to step S9. For example, the control unit 20 can obtain a desired output voltage in response to the sound pressure of a test sound wave output from the speaker 2 as an example of determination of the allowable range, or more specifically, a test output from the speaker 2. By determining whether or not the resistance value of the triaxial acceleration sensor changes linearly in response to the change in sound pressure of the sound wave, that is, whether or not the linear relationship described in FIG. It is possible to determine whether or not it has a characteristic. Note that the data is stored in a storage unit such as a memory provided in the tester 5 based on an instruction from the control unit 20 although not shown.

  In step S9, when there is no chip to be inspected next, the inspection (test) of the microstructure is finished (step S10).

  On the other hand, if there is a further chip to be inspected in step S9, the process returns to the first step S1 and the above-described inspection is executed again.

  Here, in Step S6, when it is determined that the measured characteristic value, that is, measurement data is not within the allowable range, the control unit 20 determines that the measurement is not acceptable (Step S11) and re-inspects (Step S12). Specifically, the chip determined to be out of the allowable range by re-inspection can be removed. Alternatively, even chips that are determined to be outside the allowable range can be divided into a plurality of groups. That is, even if the chip cannot satisfy the strict test conditions, there are many chips that can be actually shipped by repairing / correcting. Therefore, it is possible to sort the chips by executing the grouping by reinspection or the like and ship based on the sorting result.

  In this example, as an example, a configuration has been described in which a change in the resistance value of the piezoresistive element provided in the triaxial acceleration sensor is detected and determined in response to the movement of the triaxial acceleration sensor. In particular, it is not limited to resistance elements, and it is configured to detect and judge changes in impedance values such as capacitive elements and reactance elements, or changes in voltage, current, frequency, phase difference, delay time, position, etc. based on changes in impedance values. Is also possible.

  FIG. 10 is a diagram for explaining the frequency response of the three-axis acceleration sensor responding to the test sound wave output from the speaker 2.

  FIG. 10 shows an output voltage output from the triaxial acceleration sensor when a test sound wave of 1 Pa (Pascal) is applied as the sound pressure and the frequency is changed. The vertical axis represents the output voltage (mV) of the triaxial acceleration sensor, and the horizontal axis represents the frequency (Hz) of the test sound wave.

  Here, an output voltage obtained particularly in the X-axis direction is shown.

  As shown in FIG. 10, two regions A and B are shown. Specifically, a resonance frequency region A and a non-resonance frequency region B are shown.

  Referring to FIG. 10, the frequency at which the output voltage is maximum, that is, the maximum output voltage changed by resonating is equivalent to the resonance frequency. In FIG. 10, the frequency corresponding to this output is about 600 Hz. That is, it almost coincides with the frequency characteristic on the X axis of the above-described three-axis acceleration sensor.

  Therefore, for example, it is possible to specify the resonance frequency from the output voltage characteristics obtained by changing the frequency of the test sound wave with a constant sound pressure, and compare whether the specified resonance frequency is the desired resonance frequency. Thus, it is possible to determine whether the resonance frequency is a desired one. In this example, only the X-axis is shown, but it is possible to obtain the same frequency characteristics for the Y-axis and the Z-axis as well, so the characteristics of the acceleration sensor are evaluated simultaneously for each of the three axes. Can do.

  For example, when the resonance point, which is the resonance frequency, resonates at a frequency other than 600 Hz, it is possible to determine that it is defective because an appropriate and desired frequency cannot be obtained on that axis. In other words, the appearance inspection is difficult because it is a microstructure, so that it is possible to inspect internal structural breakage, cracks existing in the movable portion of the microstructure, and the like. Here, although the case where the resonance frequency is specified from the maximum output voltage has been described, the movable portion has the maximum displacement amount due to resonance. Therefore, the frequency at which the maximum amount of displacement is obtained corresponds to the resonance frequency. As a result, it is possible to determine the defect by specifying the resonance frequency from the maximum amount of displacement and comparing whether or not the resonance frequency is a desired resonance frequency as described above.

  Further, for example, it is possible to change the sound pressure of the test sound wave using the frequency region of region B, that is, the non-resonant frequency region, and execute detection inspection such as sensitivity and offset of the triaxial acceleration sensor from the output result.

  Further, in this example, a method of inspecting one chip TP via the probe needle 4 is described. However, since the test sound wave spreads uniformly, the same inspection is performed in parallel on a plurality of chips. It is also possible to do. Further, since the control of the frequency and sound pressure of the test sound wave is relatively easy, the configuration of the apparatus can be made simple and easy as compared with a configuration that controls the flow rate of air.

  As described above, with the configuration of the inspection method and the inspection apparatus according to the first embodiment, the characteristics of the microstructure can be improved from the movement of the movable portion of the microstructure by a simple method of controlling sound waves that are dense waves. It can be inspected with accuracy.

  Note that a program that causes a computer to execute the inspection method according to the first embodiment described with reference to the flowchart of FIG. 9 may be stored in advance in a storage medium such as an FD, a CD-ROM, or a hard disk. In this case, the tester 5 is provided with a driver device that reads the program stored in the recording medium, and the control unit 20 receives the program via the driver device and stores the program in the memory in the control unit 20. It is also possible to carry out an inspection method. Further, when connected to a network, the control unit 20 can download the program from the server and execute the above-described inspection method. In addition, for the inspection methods according to the following embodiments and modifications thereof, it is also possible for the control unit 20 to execute the inspection method in the same manner as described above by storing a program to be executed by a computer in a recording medium. is there.

  Note that the inspection method described in Patent Document 1 is a configuration in which the characteristics of a uniaxial acceleration sensor device are inspected by blowing gas, and the multiaxial acceleration is not changed unless the direction (angle) at which the gas is applied to the device is changed. The sensor cannot be tested for its characteristics. However, in the method of this configuration, it is possible to inspect the characteristics of each axis simultaneously by the movement of the movable body of the multi-axis acceleration sensor due to air vibration.

(Modification of Embodiment 1)
FIG. 11 is a schematic configuration diagram illustrating a microstructure inspection system 11 according to a modification of the first embodiment of the present invention. In the modification of the first embodiment of the present invention, the case where the characteristics of the microstructure are evaluated by a method different from that described in the first embodiment will be described.

  Referring to FIG. 11, inspection system 11 according to the modification of the first embodiment of the present invention is different in that tester 5 is replaced with tester 6. The tester 6 is different from the tester 5 in that the microphone 3 and the signal adjustment unit 35 are deleted. Since the other points are the same, detailed description thereof will not be repeated.

  A microstructure inspection method according to a modification of the first embodiment of the present invention will be described with reference to the flowchart of FIG.

  With reference to FIG. 12, the inspection (test) of the microstructure is started as described above (step S0), and the probe needle 4 is brought into contact with the pad PD of the detection chip TP (step S1). Next, the test sound wave output from the speaker 2 is set (step S2a), and then the test sound wave is output from the speaker 2 to the detection chip TP (step S2b).

  Next, the characteristic value of the detection chip is measured. Specifically, the characteristic value is measured by the measuring unit 25 based on the electrical signal transmitted through the probe needle 4 as described above (step S20).

  Next, the control unit 20 determines whether or not the characteristic value measured by the measurement unit 25, that is, measurement data, matches the desired characteristic value, that is, measurement data (step S21).

  If it is determined in step S21 that the desired characteristic value does not match, the process returns to step S2a again to reset the test sound wave. At that time, the control unit 20 causes the speaker control unit 30 to correct the test sound wave so that a desired characteristic value is obtained for the detection chip TP by the measurement of the measurement unit 25 with respect to the speaker control unit 30. Instruct. The speaker control unit 30 can obtain a desired characteristic value from the speaker 2 by finely adjusting the frequency and / or sound pressure so as to obtain a test sound wave in which a desired characteristic value is obtained in response to an instruction from the control unit 20. Control to output test sound wave.

  When it is determined in step S21 that the desired characteristic value is matched, the process proceeds to the next step S22, and the output value of the test sound wave output from the speaker 2 is measured (step S22). Specifically, the control unit 20 acquires data such as sound pressure, frequency, voltage, and the like that instructed the speaker control unit 30 to output a test sound wave from the speaker 2 so as to obtain a desired characteristic value. To do.

  Next, the control unit 20 determines whether or not the acquired data is within an allowable range (step S6). If it is determined in step S6 that it is within the allowable range, it is determined to be acceptable (step S7), and if it is determined that it is not within the allowable range, it is determined to be unacceptable (step S11). Since the subsequent steps are the same as those described in the flowchart of FIG. 9 of the first embodiment, detailed description thereof will not be repeated.

  The microstructure inspection method according to the modification of the first embodiment of the present invention is a predetermined test that is output from the speaker 2 in order to obtain a predetermined characteristic value that is detected from a chip that is passed, that is, a non-defective product. A method for determining pass or fail of a detection chip by comparing the level of sound pressure of a sound wave and the level of sound pressure of a test sound wave output to obtain the predetermined characteristic value for the detection chip It is.

  With the configuration according to the modification of the first embodiment of the present invention, the tester 6 can evaluate the characteristics of the detection chip without providing the microphone 3 and the signal adjustment unit 35 described in the first embodiment, and the number of parts The cost of the tester can be further reduced.

(Embodiment 2)
FIG. 13 is a schematic configuration diagram illustrating a microstructure inspection system 1 # according to the second embodiment of the present invention. In the second embodiment of the present invention, an inspection method and an inspection apparatus that perform an inspection with higher accuracy will be described.

  Referring to FIG. 13, inspection system 1 # according to the second embodiment of the present invention is different from inspection system 1 in that tester 5 is replaced with tester 5 #. Since the other points are the same as those of the inspection system 1 described in FIG. 1, detailed description thereof will not be repeated.

  In the second embodiment of the present invention, when there is a noise source NS at the time of a test, a highly accurate inspection is performed by canceling a noise sound wave emitted from the noise source.

  Tester 5 # according to the second embodiment of the present invention is different from tester 5 in that noise removal control unit 40, speaker 2 #, and microphone 3 # are further included. Since the other points are the same, detailed description thereof will not be repeated.

  A microstructure inspection method according to the second embodiment of the present invention will be described with reference to the flowchart of FIG.

  Referring to FIG. 14, the difference from the inspection method described in FIG. 9 is that step S13 to step S16 are further added between step S1 and step S2a. Specifically, after step S1, a noise sound wave is detected using the microphone 3 # (step S13). Specifically, microphone 3 # detects a noise sound wave emitted from noise source NS and outputs the result to noise removal control unit 40. Then, in response to the instruction from the control unit 20, the noise removal control unit 40 sets an anti-noise sound wave that cancels the noise sound wave emitted from the noise source NS to the speaker 2 # (step S14), and detects the detection chip from the speaker. The TP is instructed to output an anti-noise sound wave (step S15). Specifically, an anti-noise sound wave having the same frequency as that of the noise sound wave and the same sound pressure and having a phase opposite to that of the noise sound wave is output. As a result, as shown in FIG. 15, for example, an anti-noise sound wave fantinoise having a completely opposite phase to the noise sound wave fnoise emitted from the noise source NS is output from the speaker 2 #, and is synthesized to be a chip of the microstructure. When the sound wave reaches the TP, the noise sound wave fnoise is canceled and hardly exists.

  And the control part 20 determines whether the noise sound wave was able to be removed based on the output result from the signal adjustment part 35 via the microphone 3 (step S16). If it is determined that it has been removed, the process proceeds to the next step S2a described above, and the subsequent processing is the same as that described with reference to FIG. 9, and thus detailed description thereof will not be repeated.

  On the other hand, if it is determined in step S16 that the noise sound wave has not been removed, the process returns to step S14 again. That is, the anti-noise sound wave is reset. At that time, the control unit 20 instructs the noise removal control unit 40 to correct the anti-noise sound wave to the speaker control unit 30. Noise removal control unit 40 finely adjusts the frequency and / or sound pressure and / or phase so as to obtain a desired anti-noise sound wave in response to an instruction from control unit 20, and outputs the anti-noise sound wave from speaker 2 #. Control to do.

  By the inspection method and inspection apparatus according to the second embodiment of the present invention, noise can be removed or canceled as a pre-process before outputting the test sound wave, and a high-precision inspection is performed in a noise-free situation during the test. can do.

  In this example as well, when a desired test sound wave reaches the microstructure of the detection chip in advance, it is possible to employ a configuration in which no correction means and method are provided. Specifically, the processes from step S2a to S4 are executed in advance before the test is started, and the speaker control unit 30 stores a corrected control value for outputting a desired test sound wave. Then, when testing the actual microstructure, the speaker control unit 30 controls the input to the speaker 2 with the recorded control value, thereby omitting the processes of steps S3 and S4 during the test. Is also possible.

(Modification 1 of Embodiment 2)
FIG. 16 is a schematic configuration diagram of an inspection system 1 # a according to the first modification of the second embodiment of the present invention.

  Referring to FIG. 16, inspection system 1 # a according to the first modification of the second embodiment of the present invention replaces tester 5 # with tester 5 # a as compared with inspection system 1 # described in FIG. Different points. Specifically, tester 5 # a differs in that speaker 2 # is deleted and noise removal control unit 40 is replaced with noise removal control unit 40 # and speaker control unit 30 #. Since the other points are the same as those of the inspection system described with reference to FIGS. 1 and 13, detailed description thereof will not be repeated.

  The noise removal control unit 40 # of the tester 5 # a according to the first modification of the second embodiment of the present invention outputs the above-described anti-noise sound wave for removing the noise sound wave detected by the microphone 3 # from the speaker 2. To the speaker control unit 30 #. The speaker control unit 30 # instructs the speaker 2 to output the anti-noise sound wave together with the test sound wave in response to the instructions from the control unit 20 and the noise removal control unit 40.

  Thereby, the anti-noise sound wave and the test sound wave are generated using the same speaker 2, and the noise sound wave and the anti-noise sound wave cancel each other as described in FIG. 13, and only the test sound wave reaches the chip TP of the microstructure. It will be.

  By generating the anti-noise sound wave and the test sound wave using the speaker 2 as in the configuration of the first modification according to the second embodiment of the present invention, the number of parts can be further reduced and the cost can be reduced.

  In the configuration according to the above-described embodiment, the speaker control unit 30 outputs a test sound wave that is a sine wave having a single frequency from the speaker. However, the present invention is not limited to this. It is also possible to combine sine wave signals of different frequencies and output from the speaker. As a result, since responses to a plurality of frequencies can be detected at a time, the inspection of the frequency response characteristics as described with reference to FIG. 10 can be performed efficiently and effectively. For example, if the frequency band to be inspected is divided into a high band and a low band, a sine wave signal selected from the high band and the low band is synthesized and output from the speaker, and the response signal is separated by a band filter, Responses to two frequencies can be detected simultaneously.

  The test sound wave output from the speaker is not limited to a sine wave signal or its synthesis, and a test sound wave having an arbitrary waveform such as white noise (white noise) is output using a function generator (arbitrary waveform generator) (not shown). May be. Thus, for example, white noise is a sound containing almost the same amount of all frequency components, so the microstructure shows a response in which the resonance of the movable part is dominant, and the microstructure is detected by detecting the response. The resonance frequency of the body and its vibration characteristics can be easily inspected. At that time, for example, by using a band-pass filter or the like to set the white frequency of the test sound wave to a region close to the resonance frequency of the microstructure, the resonance characteristics of the microstructure can be efficiently and effectively inspected. It is also possible to execute.

  FIG. 32 is a graph showing a result of simultaneously detecting three-axis responses by outputting white noise in a certain frequency range as a test sound wave. A test sound wave due to white noise was output, and the 3-axis output signals of the measurement time were each Fourier transformed and plotted against frequency. FIG. 32 shows a single measurement result. As can be understood from FIG. 32, peaks indicating the resonance frequencies of the X axis, the Y axis, and the Z axis appear. It can be seen that the X axis and the Y axis have a resonance frequency near 1220 to 1240 Hz, and the Z axis has a resonance frequency near 1980 Hz. Since the measurement time and the frequency band of the test sound wave are limited, the input is pseudo white noise, but the resonance frequency and the average output level can be evaluated. In order to inspect the characteristics of the microstructure more correctly, it is preferable to normalize the frequency component of the output signal for each frequency as a result of Fourier transform of the test sound wave for the measurement time. Further, the measurement may be performed a plurality of times and an average for each frequency may be taken. Further, if a moving average for each appropriate frequency section is taken and plotted on a graph, the unevenness of the graph as shown in FIG. 32 is leveled, so it is easy to grasp the characteristics visually.

(Modification 2 of Embodiment 2)
In the second modification of the second embodiment of the present invention, a method for removing noise, that is, performing noise cancellation, using a method different from the method for removing noise described above with reference to FIG. 14 will be described.

  A microstructure inspection method according to the second modification of the second embodiment of the present invention will be described using the flowchart in FIG.

  Referring to FIG. 17, the difference from the inspection method described in FIG. 14 is that steps S13 to S16 are replaced with S30 to S33.

  Specifically, after step S1, noise sound waves are detected using the characteristic value of the detection chip detected via the probe needle (step S30). Specifically, when the probe needle is brought into contact with the pad of the detection chip, the movable part moves due to the noise sound wave or vibration emitted from the noise source NS, and a predetermined characteristic value is detected from the detection chip via the probe needle. . The measurement unit 25 outputs the result to the control unit 20. The control unit 20 instructs the noise removal control unit 40 to remove noise based on the predetermined characteristic value measured by the measurement unit 25. Then, the noise removal control unit 40 sets the anti-noise sound wave so as to cancel the noise sound wave emitted from the noise source NS to the speaker in response to the instruction from the control unit 20 (step S31), and detects the detection chip from the speaker. The TP is instructed to output an anti-noise sound wave (step S32). Specifically, an anti-noise sound wave having the same frequency as that of the noise sound wave and the same sound pressure and having a phase opposite to that of the noise sound wave is output. Thus, as described above, as shown in FIG. 16, for example, the noise sound wave fnoise emitted from the noise source NS and the anti-noise sound wave fantinoise having a completely opposite phase to the noise sound wave NS are output from the speaker 2 # so that they are synthesized to be minute. When reaching the structure chip TP, the noise sound wave fnoise is canceled and almost no longer exists.

  And the control part 20 determines whether the noise sound wave was able to be removed (step S33). Specifically, it is determined whether or not a predetermined characteristic value from the detection chip detected by the measurement unit 25 via the probe needle becomes 0, that is, whether or not the predetermined characteristic value is not detected.

  When it is determined that the predetermined characteristic value is no longer detected by the measuring unit 25 via the probe needle, that is, it is determined that the noise sound wave has been removed, the process proceeds to the next step S2a described above, and the subsequent processing is described in FIG. Therefore, detailed description thereof will not be repeated. Alternatively, it is possible to proceed to step S2a and execute a later test process according to the method described in FIG.

  On the other hand, if it is determined in step S33 that the noise sound wave has not been removed, the process returns to step S31 again. That is, the anti-noise sound wave is reset. At that time, the control unit 20 instructs the noise removal control unit 40 to correct the anti-noise sound wave to the speaker control unit 30. The noise removal control unit 40 responds to an instruction from the control unit 20 so that a desired anti-noise sound wave is obtained, that is, a predetermined characteristic value measured through the probe needle by the measurement unit 25 is zero. And / or the sound pressure and / or the phase are finely adjusted to control to output the anti-noise sound wave from the speaker.

  In the inspection method according to the second modification of the second embodiment of the present invention, as in the inspection methods according to the second embodiment and the first modification, noise can be removed, that is, canceled as preprocessing before outputting the test sound wave. It is possible to perform a highly accurate inspection in a noise-free situation at the time of testing.

  Furthermore, in the inspection method according to the second modification of the second embodiment of the present invention, there is no need to detect noise sound waves using a microphone, and the microphone 3 # is reduced from the testers 5 # and 5 # a described above. That is, the number of parts can be reduced and the cost of the tester can be reduced.

  In the inspection method according to the second modification of the second embodiment of the present invention, the test sound wave is output after setting the characteristic value of the detection chip detected through the probe needle to 0 as preprocessing for outputting the test sound wave. It is a method to test. That is, since the test is performed in a state in which the influence of noise is more completely removed from the actual measurement result, a test with higher accuracy than the method described in the second embodiment and the first modification can be performed. .

  In the above embodiment, the three-axis acceleration sensor has been described as an example of the microstructure. However, as described above, there are various MEMS technologies, and the microstructure targeted by the present technology is a multi-axis acceleration sensor. It is not limited. The present technology can be used for performance inspection of operation characteristics and mechanical characteristics of actuators and micromachine parts exemplified below.

  FIG. 18 is a conceptual diagram schematically illustrating a cantilever type MEMS switch (hereinafter also simply referred to as a switch).

  FIG. 18A illustrates a case where the switch is stationary. Referring to FIG. 18A, the switch includes a substrate 50, a cantilever 51, a control electrode 52, a cantilever joint portion 53, and a joint electrode 54. The switch does not operate in a state where no control signal is input.

  FIG. 18B is a diagram illustrating a case where the switch operates. When the control signal is applied to the control electrode 52, the cantilever 51 is attracted to the control electrode 52 side. As a result, the cantilever joint 53 comes into contact with the joint electrode 54. As a result, the switch is turned on. As an example, if a pulse-like control signal is given to the control electrode 52, the cantilever joint 53 moves up and down and repeats the joining state / non-joining state with the joining electrode 54. This switch is very small and is used as a switch that changes the frequency at high speed.

  FIG. 19 is a conceptual diagram schematically illustrating a MEMS switch having a thin film membrane structure.

  FIG. 19A is a diagram for explaining signal wirings and electrodes.

  Referring to FIG. 19A, a signal wiring 72 to which a signal is input and a signal wiring 73 to be output are shown. A groove is provided between the signal wirings in the vicinity of the central portion, and an electrically insulated state is shown. Further, electrodes 70 and 71 are provided on both sides thereof.

  FIG. 19B is a diagram illustrating a case where the membrane structure is used as a switch. As shown in FIG. 19B, a membrane is disposed above the signal wirings 72 and 73. The thin film beam is a flexible spring. This supports the membrane 74. By applying a driving voltage to the electrodes 70 and 71, the membrane 74 is bent by the electrostatic attraction and pulled downward, and comes into contact with the signal wiring provided thereunder. As a result, the groove between the signal wirings is filled, and the conductive state (ON) is established. That is, the signal wirings 72 and 73 become conductive, and the input signal is output. On the other hand, when the membrane and the signal wiring are not in contact with each other, they are in a non-conductive state (off).

  In the above, the example using the membrane structure for the switch has been described. However, the membrane structure is not limited to the switch, and is also used as a sensor component such as a temperature sensor. In addition, the thin film part, which is the movable part of the membrane structure, is not moved when the product is used, and various mechanical parts such as electron / ion-passing thin films using the properties of the thin film or the irradiation window of the electron beam irradiator can be used for performance inspection with this technology Is possible.

  FIG. 20 is a diagram illustrating a case where a membrane structure is used for the irradiation window of the electron beam irradiator. As shown in FIG. 20, a part of an irradiation window 80 through which an electron beam EB is emitted from the vacuum tube 81 to the atmosphere is shown. As shown in the enlarged cross-sectional structure, a thin film membrane is shown. Structure is adopted. In FIG. 20, the membrane is formed of a single material and only one membrane structure is illustrated. However, the membrane may be formed of a plurality of materials as a multilayer film structure, or a plurality of membranes may be formed. In some cases, the structure is an irradiation window arranged in an array. Even a mechanical part having such a movable part can be inspected for the presence or absence of film breakage, cracks and film quality by the technique of the present invention.

  FIG. 21 is a schematic configuration diagram illustrating an ink jet printer head.

  FIG. 21A is a diagram illustrating a case where the inkjet printer head is stationary. Referring to FIG. 21A, the ink jet printer head is bonded to the nozzle 60, the piezoelectric actuator 61, the covering member 62, the support member 64 that supports the piezoelectric actuator 61, the control electrode 63a, and the piezoelectric actuator 61. The control electrode 63b, the substrate 65, and the switch 66 are configured. When the switch 66 is off, the ink jet printer head does not operate. It is assumed that ink is filled between the covering member 62 and the piezoelectric actuator 61.

  FIG. 21B is a diagram illustrating a case where the ink jet printer head operates.

  Referring to FIG. 21B, in the inkjet printer head, when the switch 66 is turned on, an electrostatic attractive force acts between the control electrode 63a and the piezoelectric actuator 61. Along with this, the piezoelectric actuator 61 bends as shown.

  FIG.21 (c) is a figure explaining the case where a switch is turned off after FIG.21 (b).

  As shown in FIG. 21C, the bent piezoelectric actuator 61 returns to the original state. Ink filled inside is ejected from the nozzle 60 by the repulsive force obtained at this time. This inkjet printer head is used as a fine and high-speed printer head by executing the above-described operation.

  When a sound wave of an appropriate magnitude is applied to the ink jet printer head, the piezoelectric actuator 61 is deformed, and the capacitance between the control electrodes 63a and 63b changes. By detecting this change in capacitance, the ink jet printer head can be inspected.

  FIG. 33 is a conceptual configuration diagram illustrating the pressure sensor. 33A is a plan view of the pressure sensor, and FIG. 33B is a cross-sectional view taken along the line AA in FIG. 33A. As shown in FIG. 33, a diaphragm D, which is a thin portion, is formed in a substantially square shape at the center of the silicon substrate Si. Piezoresistors R1, R2, R3, and R4 are formed at the centers of the four sides of the diaphragm D, respectively. When the diaphragm D is deformed due to the difference in pressure applied to both surfaces of the diaphragm D, stress is generated in the piezoresistors R1 to R4. Since the electrical resistance values of the piezoresistors R1 to R4 change due to the stress, the pressure difference applied to both surfaces of the diaphragm D can be measured by detecting the change.

  As for the pressure sensor, the operation of the pressure sensor can be confirmed by the method of the present invention in a state where the pressure sensor is formed on the substrate (for example, on the wafer). In the method of actually checking the operation by applying pressure, it is necessary to generate a pressure difference on both surfaces of the wafer, and it is difficult to inspect in a state where the pressure sensor is formed on the wafer.

  These MEMS devices such as the above-described RF switch and ink jet printer head can be inspected according to the same method as described above.

  According to the method of the present invention, when the above-described acceleration sensor (or angular velocity sensor), MEMS switch, membrane structure, ink jet printer head, pressure sensor, etc. are combined to form a microstructure by combining movable parts having different characteristics. For example, when an acceleration sensor and a pressure sensor are combined to form one microstructure, it is possible to simultaneously inspect the characteristics of the plurality of movable parts. In MEMS technology, a plurality of microstructures are often formed on a substrate. However, according to the method of the present invention, a plurality of microstructures formed on one substrate can be inspected simultaneously. Is possible. By simultaneously inspecting a plurality of movable parts, a plurality of movable parts having different characteristics, or a plurality of microstructures, the MEMS manufacturing process can be shortened. In addition, since the inspection can be performed in a state in which the microstructure is formed on the substrate, the subsequent packaging process and the like can be omitted for defective products.

(Embodiment 3)
In the system shown in the first and second embodiments, the microstructure is detected by detecting an electrical signal output from the microstructure by mainly bringing the probe needle into contact with the pad of the chip of the microstructure. A method for inspecting the characteristics of the above has been described.

  In the third embodiment of the present invention, a method capable of inspecting the characteristics of a microstructure without directly using an electrical signal output from the microstructure will be described. Specifically, description will be made using an irradiation window of an electron beam irradiator having a membrane structure.

  FIG. 22 is a conceptual diagram illustrating measurement unit 25 # according to the third embodiment of the present invention.

  Specifically, measurement unit 25 # according to the third embodiment of the present invention includes a measurement unit 46 and a measurement jig 45. Further, the measurement unit 46 and the measurement jig 45 are electrically coupled via a terminal TP. The measurement unit 46 detects the capacitance between the electrode ED and the measurement object during the test.

  Measurement jig 45 includes a plurality of pads PD # provided around the outer region and a plurality of electrodes ED provided in the inner region. In this example, it is assumed that one electrode ED is provided corresponding to one pad PD # of the plurality of pads PD # and is electrically coupled to each other.

  FIG. 22 shows an example in which one pad PD # and terminal TP are electrically coupled.

  An irradiation window 80 of an electron beam irradiator having a membrane structure, which is a microstructure, is placed on the measurement jig 45 as an example. The tester according to the third embodiment has a configuration in which the probe needle 4 is removed and the measurement unit 25 of the tester described with reference to FIG. 1 is replaced with a measurement unit 25 #. Since it is the same structure, the detailed description is not repeated.

  FIG. 23 is a diagram for explaining in detail the measurement jig 45 and the irradiation window 80 of the electron beam irradiator placed thereon.

  Referring to FIG. 23, electrode ED is provided on the surface of measurement jig 45. A spacer 47 is provided for securing a predetermined distance L between the electrode ED and the irradiation window 80. In addition, electrode ED and external pad PD # are electrically coupled as described above.

  The microstructure inspection method according to the third embodiment of the present invention will be described using the flowchart of FIG.

  As described above, the inspection (test) of the microstructure is started (step S0). At this time, it is assumed that the irradiation window 80 of the electron beam irradiator, which is a microstructure to be inspected, is placed on the measurement jig 45. Next, the test sound wave output from the speaker 2 is set (step S2a), and then the test sound wave is output from the speaker 2 to the irradiation window 80 (step S2b). Steps S3 and S4 are the same as steps S3 and S4 of FIG. 9 described in the first embodiment.

  Next, the characteristic value of the detection chip is measured. In this example, the capacitance value that changes based on the displacement of the movable part that moves due to the density wave output from the speaker 2 is measured by the measurement unit 46 of the measurement unit 25 # (step S5a).

  Next, the control unit 20 determines whether or not the characteristic value measured by the measurement unit 25 #, that is, measurement data, is a desired characteristic value, that is, an allowable range (step S6).

  Since the subsequent processing is the same method as that described in FIG. 9, detailed description thereof will not be repeated.

  The method for inspecting a microstructure according to the third embodiment of the present invention is a method for inspecting the characteristics of the microstructure based on an electric signal or the like directly obtained from the microstructure by the movement of the movable part as described in FIG. Rather, it is an inspection method based on characteristic values indirectly measured from the movement of the microstructure.

  FIG. 25 is another diagram illustrating in detail the measurement jig 45 and the irradiation window 80 of the electron beam irradiator placed thereon.

  Referring to FIG. 25, the difference from the irradiation window 80 shown in FIG. 23 is that the irradiation window 80 of the membrane structure shown in FIG. The irradiation window 80 of the membrane structure shown is arranged as facing up. In addition, a spacer 48 and a sub-electrode Eda are provided on the electrode ED, and the electrode ED and the sub-electrode Eda are electrically coupled by a contact hole that penetrates the spacer 48. Then, as described with reference to FIG. 23, the distance between the electrode, that is, the sub electrode EDa, and the membrane structure is set to be L.

  Also in the case of FIG. 25, the inspection of the microstructure can be executed according to the same method as described in FIG.

  In addition, the microstructure triaxial acceleration sensor described above can be inspected according to the same method.

  FIG. 26 is a diagram illustrating the resonance frequency when the probe needle is applied to the pad of the triaxial acceleration sensor. As shown in this example, the resonance frequency tends to decrease as the probe pressure applied to the pad increases. Therefore, without using a probe needle, the predetermined resonance frequency is changed by detecting and inspecting the capacitance value that changes based on the displacement of the movable part that moves due to the dense wave output from the speaker described above. And can be easily inspected.

  FIG. 27 is a conceptual diagram illustrating another measuring unit 25 # a of the present invention.

  Referring to FIG. 27A, here, a chip TP of a triaxial acceleration sensor is placed on measurement unit 25 # a. Measurement unit 25 # a includes capacitance detection circuits CS1, CS2, electrode EDb, and measurement unit 46 #. The tester of this example similar to the above has a configuration in which the probe needle 4 is removed and the measurement unit 25 of the tester described in FIG. 1 is replaced with a measurement unit 25 # a. Other control units, speakers, and the like Since is the same configuration, detailed description thereof will not be repeated.

  The two electrodes EDb are provided below the weight body AR of the three-axis acceleration sensor and are electrically coupled to the capacitance detection circuits CS1 and CS2, respectively. Capacitance detection circuits CS1 and CS2 are connected to measurement unit 46 # and output the detected capacitance value. Measurement unit 46 # measures the changing capacitance value.

  FIG. 27B is a circuit configuration diagram illustrating capacitance detection in the measurement unit 25 # a.

  As shown in this example, between the weight body AR and the electrode EDb, initial capacitances Cd1 and Cd2 are detected by the capacitance detection circuits CS1 and CS2, respectively. These detection results are output to the measurement unit 46 #.

  FIG. 28 is a diagram illustrating a case where the movable part of the chip TP is displaced.

  Referring to FIG. 28A, the weight body AR that is a movable portion is displaced by the dense wave from the speaker 2.

  As shown in FIG. 28B, when the weight AR is displaced, the capacitance detection circuits CS1 and CS2 output the detected capacitance values to the measurement unit 46 #. In this example, the capacitance value is displaced from Cd1 to Cd1 + ΔC1 and from Cd2 to Cd2 + ΔC2 with the displacement of the movable part. This change amount can be detected by the measurement unit 46 # and output to the control unit 20, and the characteristics of the triaxial acceleration sensor can be inspected. Note that the method for inspecting the microstructure in this case is the same method as that described with reference to the flowchart of FIG. 24, and thus detailed description thereof will not be repeated.

  FIG. 29 is a diagram for explaining detection electrodes provided in the lower part of the three-axis acceleration sensor.

  FIG. 29A shows the case where the electrodes EDb are provided corresponding to the respective weights AR as described above. However, as shown in FIG. Correspondingly, it is possible to inspect according to the same method as described above by providing one electrode ED #. Alternatively, as shown in FIG. 29 (c), in this example having a larger detection area than the electrode EDb shown in FIG. 29 (a), an inspection is performed by providing an electrode ED # a larger than the bottom area of the weight AR It is also possible.

  Note that the method shown in FIG. 24 of the present application is the same method as in the case where step S1 described in FIG. 9 of the first embodiment is omitted. That is, this is a method for evaluating the characteristics of the microstructure based on whether or not desired characteristic data is detected in accordance with the test sound wave applied from the speaker 2. Similarly, it is also possible to evaluate the characteristics according to the method described in FIG. 12 of the modification of the first embodiment, the second embodiment, and FIGS. That is, the test sound wave for obtaining desired characteristic data is adjusted, and the characteristics of the microstructure are evaluated depending on whether the data such as the sound pressure of the obtained test sound wave is within the allowable range, or the noise sound wave Even in the case where the problem occurs, a desired test can be executed by outputting an anti-noise sound wave. As described above, the tester can be realized by deleting the probe needle 4 of FIGS. 1, 11, 13, and 16 and changing the measuring unit 25 to the measuring unit 25 # or 25 # a described above. It is.

  Note that it is also possible to evaluate the characteristics from the movement of the movable part of the microstructure with the naked eye by applying sound waves that are dense waves. Alternatively, a sound wave that is a sparse / dense wave is applied to the microstructure, and the displacement of the movable portion of the microstructure is detected using a so-called laser displacement meter, displacement sensor, proximity sensor, or the like, and the detected displacement amount is It is also possible to evaluate the characteristic by comparing and determining whether or not the displacement amount is a desired amount by using a determination means or the like.

  FIG. 30 is a diagram for explaining a case where the characteristic is evaluated by detecting the displacement of the movement of the movable portion of the microstructure by the laser displacement meter LZ which is a measurement unit.

  Also in this case, the characteristics of the irradiation window 80 of the electron beam irradiator can be tested depending on whether or not a desired displacement has been detected.

  In addition to the irradiation window of the electron beam irradiator, as shown in FIG. 31, it is also possible to detect the displacement of the movement of the movable part of the acceleration sensor by a laser displacement meter LZ as a measurement part and test the characteristics. It is.

  Also in the third embodiment, it is possible to simultaneously inspect a plurality of movable parts, a plurality of movable parts having different characteristics, or a plurality of microstructures. Further, by applying white noise or white noise in a predetermined frequency range to the microstructure as the test sound wave, the characteristics of the microstructure can be inspected without scanning the frequency of the test sound wave.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a schematic configuration diagram of a microstructure inspection system according to a first embodiment of the present invention. It is the figure seen from the device upper surface of a 3-axis acceleration sensor. It is the schematic of a 3-axis acceleration sensor. It is a conceptual diagram explaining the deformation | transformation of the heavy cone and beam at the time of receiving the acceleration of each axial direction. It is a circuit block diagram of the Wheatstone bridge provided with respect to each axis. It is a figure explaining the output response with respect to the inclination-angle of a 3-axis acceleration sensor. It is a figure explaining the relationship between gravitational acceleration (input) and a sensor output. It is a figure explaining the frequency characteristic of a 3-axis acceleration sensor. It is a flowchart figure explaining the inspection method of the microstructure according to Embodiment 1 of the present invention. It is a figure explaining the frequency response of the 3-axis acceleration sensor which responds to the test sound wave output from the speaker. It is a schematic block diagram explaining the test | inspection system of the micro structure according to the modification of Embodiment 1 of this invention. It is a flowchart figure explaining the inspection method of the microstructure according to the modification of Embodiment 1 of the present invention. It is a schematic block diagram explaining the inspection system of the microstructure according to the second embodiment of the present invention. It is a flowchart figure explaining the inspection method of the microstructure according to Embodiment 2 of the present invention. It is a figure explaining the synthesis | combination of the noise sound wave emitted from a noise source, and the anti noise sound wave of completely opposite phase. It is a schematic block diagram of the test | inspection system according to the modification 1 of Embodiment 2 of this invention. It is a flowchart figure explaining the inspection method of the microstructure according to the modification 2 of Embodiment 2 of the present invention. It is a conceptual diagram which illustrates a cantilever type MEMS switch schematically. It is a conceptual diagram which illustrates roughly the MEMS switch which has a thin film membrane structure. It is a figure explaining the case where the membrane structure is used for the irradiation window of an electron beam irradiator. It is a schematic block diagram explaining an inkjet printer head. It is a conceptual diagram explaining the measurement part according to Embodiment 3 of this invention. It is a figure explaining in detail the measurement jig and the irradiation window of the electron beam irradiation machine mounted on it. It is a flowchart figure explaining the inspection method of the microstructure according to Embodiment 3 of this invention. It is another figure explaining a measurement jig and the irradiation window of the electron beam irradiation machine mounted on it in detail. It is a figure explaining the resonant frequency when a probe needle is applied to the pad of a triaxial acceleration sensor. It is a conceptual diagram explaining the other measurement part of this invention. It is a figure explaining the case where the movable part of a chip | tip is displaced. It is a figure explaining the detection electrode provided in the lower part of a 3-axis acceleration sensor. It is a figure explaining the case where the characteristic is evaluated by detecting the displacement of the movement of the movable part of a micro structure with the laser displacement meter which is a measurement part. It is a figure explaining the case where the displacement of the motion of the movable part of an acceleration sensor is detected with the laser displacement meter which is a measurement part, and the characteristic is evaluated. It is a graph which shows the result of having detected the white noise of a certain frequency range as a test sound wave, and having detected the 3-axis response of the 3-axis acceleration sensor simultaneously. It is a conceptual block diagram explaining a pressure sensor.

Explanation of symbols

1, 1 #, 1 # a, 11 Inspection system, 2, 2 # speaker, 3, 3 # microphone, 4
Probe needle, 5, 5 #, 5 # a, 6 tester, 10 substrate, 15 input / output interface, 20 control unit, 25, 25 #, 25 # a measurement unit, 30, 30 # speaker control unit, 35 signal adjustment unit , 40, 40 # Noise removal control unit.

Claims (18)

A microstructure inspection apparatus for evaluating the characteristics of at least one microstructure having a movable part formed on a substrate,
A sound wave generating means for outputting a test sound wave to the microstructure during a test;
Detecting the movement of the movable portion of the microstructure in response to the test sound wave output by the sound wave generation means, and comprising an evaluation means for evaluating the characteristics of the microstructure based on the detection result,
The sound wave generating means includes
A sound wave output means for outputting the test sound wave having a sound pressure according to an external input;
Detecting means for detecting a test sound wave reaching the vicinity of the microstructure;
A sound wave correcting unit that compares the sound pressure level of the test sound wave detected by the detecting unit with the sound pressure level of a predetermined test sound wave serving as a reference, and corrects the test sound wave output from the sound wave output unit. ,
The evaluation means includes
An electrode electrically insulated from the microstructure, and a capacitance detection electrode disposed opposite the movable part;
Capacitance for detecting the capacitance between the capacitance detection electrode and the movable portion of the microstructure, which are changed by the movement of the movable portion of the microstructure, from a terminal provided on the capacitance detection electrode side Detection means;
Inspecting the microstructure including a determination unit that evaluates the characteristics of the microstructure based on a comparison between the changed capacitance detected by the capacitance detection unit and a capacitance that is a predetermined threshold value. apparatus.   2. The microstructure inspection apparatus according to claim 1, wherein a plurality of the microstructures are arranged in an array on the substrate.   The determination unit responds to the test sound wave output by the sound wave generation unit based on a comparison between the changed capacitance detected by the capacitance detection unit and a capacitance that is a predetermined threshold value. The microstructure inspection apparatus according to claim 1, wherein the movement of the movable portion of the microstructure is detected, and the characteristics of the microstructure are evaluated based on a detection result. 4. The microstructure inspection device according to claim 1, wherein the sound wave generation unit further includes a noise removal unit for removing noise sound waves that reach the microstructure from outside. 5. The noise removing unit is configured to output an anti-noise sound wave having an opposite phase to the noise sound wave and having the same frequency and sound pressure so as to cancel the noise sound wave based on the noise sound wave detected by the detection unit before the test. The micro structure inspection apparatus according to claim 4 , which outputs the micro structure. 6. The microstructure inspection apparatus according to claim 5 , wherein the anti-noise sound wave is output together with the test sound wave from the sound wave output means during the test. Said evaluating means receives the detection result of the detected test sound wave by the detecting means of said sound wave generator, and outputs the result of the determination device for inspecting a micro structure according to claim 1, wherein. The micro structure inspection apparatus according to any one of claims 1 to 7 , wherein the micro structure corresponds to at least one of a pressure sensor, an acceleration sensor, and an angular velocity sensor. The evaluation means detects two or more movements of the movable part of the microstructure at the same time, and simultaneously evaluates two or more characteristics of the microstructure based on a detection result. The inspection apparatus for a microstructure according to any one of 1 to 8 . The evaluation means simultaneously detects movements in two or more directions of the movable portion of the microstructure, and simultaneously evaluates characteristics of the microstructure in two or more directions based on the detection result. The micro structure inspection apparatus according to claim 9 . The evaluation means is a case where the microstructure has two or more movable parts and / or a case where the microstructure has two or more microstructures on the substrate, and the movement of the two or more movable parts is detected. The micro structure inspection according to claim 9 , wherein simultaneous detection and characteristics of two or more movable parts of one or two or more micro structures are simultaneously evaluated based on the detection result. apparatus. When the two or more movable parts have different movable characteristics, the evaluation means simultaneously detects movements of the two or more movable parts, and two or more having the different movable characteristics based on the detected result. The micro structure inspection apparatus according to claim 11 , wherein the characteristics of the movable parts are simultaneously evaluated. The microscopic structure inspection apparatus according to any one of claims 1 to 12 , wherein the sound wave generation unit outputs a synthetic wave including sound waves having two or more different frequencies as the test sound wave. The sound wave generator outputs white noise as said test sound wave device for inspecting a micro structure according to any one of claims 1 to 12. The microscopic structure inspection apparatus according to any one of claims 1 to 12 , wherein the sound wave generation unit outputs white noise in a predetermined frequency range as the test sound wave. The said evaluation means changes at least one of the frequency and sound pressure of the sound wave which a sound wave generation means outputs, and the change of the signal accompanying the change of a sound wave is evaluated, The any one of Claims 1-15 characterized by the above-mentioned. The microstructure inspection apparatus according to one item. Providing a test sound wave to at least one microstructure having a movable part formed on a substrate;
Detecting the movement of the movable part of the microstructure in response to the test sound wave, and comprising an evaluation step for evaluating the characteristics of the microstructure based on the detection result,
Providing the test sound wave comprises:
A sound wave output step for outputting the test sound wave having a sound pressure according to an external input;
A detection step of detecting a test sound wave that reaches the vicinity of the microstructure;
A sound wave correction step of comparing the sound pressure level of the test sound wave detected by the detection step with the sound pressure level of a predetermined test sound wave serving as a reference, and correcting the test sound wave output by the sound wave output step. ,
The evaluation step includes
A capacitance detection step of detecting a capacitance between a capacitance detection electrode installed to face the movable portion of the microstructure and the movable portion of the microstructure;
And a determination step of evaluating characteristics of the microstructure based on the capacitance detected in the capacitance detection step. On the computer,
Controlling to provide test sound waves to at least one microstructure having a movable portion formed on a substrate;
A capacitance between a capacitance detection electrode installed to face the movable portion of the microstructure and a movable portion of the microstructure is detected, and the microstructure is based on the detected capacitance. An evaluation step to evaluate the characteristics of the body;
A computer program for causing the execution,
The step of controlling to provide the test sound wave comprises:
A sound wave output step for outputting the test sound wave having a sound pressure according to an external input;
A detection step of detecting a test sound wave that reaches the vicinity of the microstructure;
A sound wave correction step of comparing the sound pressure level of the test sound wave detected in the detection step with the sound pressure level of a predetermined test sound wave serving as a reference, and correcting the test sound wave output in the sound wave output step. , Computer program.

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