Ultrasonic inspection device and ultrasonic inspection method

Abstract

To provide an ultrasonic inspection device and a method for ultrasonic inspection that can precisely measure a joint body having an adhesive layer in the air.SOLUTION: An inspection device 100 includes: a transmission unit 110 for transmitting an ultrasonic wave to an inspection target object A10; a reception unit 120 for receiving an ultrasonic wave having passed through the inspection target object A10; a frequency selection unit for selecting a frequency of the ultrasonic wave transmitted by the transmission unit 110 according to material information of the inspection target object A10; and a determination unit. The determination unit determines whether there is a non-adhesive part in the adhesive layer A13 from a transmission wave amplitude index of the ultrasonic wave received by the reception unit 120 and the correspondence between the transmission wave amplitude index of the ultrasonic wave determined in advance and the non-adhesive part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The technical field of the present specification relates to an ultrasonic inspection device and an ultrasonic inspection method for inspecting an object having an adhesive thereon. [Background technology]

[0002] There is a technology that inspects the condition of an object by irradiating the object with ultrasonic waves and receiving the transmitted or reflected waves of the ultrasonic waves. Ultrasonic inspection methods include methods that measure using liquids and methods that measure in air. Because ultrasonic waves are more easily attenuated in gas than in liquids, the accuracy of measurement methods that use liquids tends to be higher than that of measurement methods that use gas. On the other hand, the inspection efficiency of measurement methods that measure in air is higher than that of measurement methods that use liquids.

[0003] For example, Patent Document 1 discloses a technology for measuring minute flaws inside an object to be inspected using an airborne ultrasonic method. The technology in Patent Document 1 measures flaws based on the presence or absence of scattered waves generated by the flaw. In Example 1, it is claimed that flaws as small as 2 mm in width can be detected. However, because scattered waves with low intensity are used for measurement, there is a risk that the signal-to-noise ratio will be low. For this reason, it is believed that the technology in Patent Document 1 has difficulty detecting smaller flaws. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-032810 [Non-patent literature]

[0005] [Non-Patent Document 1] Schadow, F., Brackrock, D., Gaal, M., Heckel, T., Procedia Structural Integrity, Vol.7(2017), pp299-306 Summary of the Invention [Problem to be solved by the invention]

[0006] A general airborne ultrasonic method is described in Non-Patent Document 1. According to Non-Patent Document 1, the size of scratches that can be measured by the general airborne ultrasonic method is about 2 mm to 3 mm. In other words, it is difficult to measure minute scratches on the order of millimeters or less.

[0007] In the airborne ultrasonic method, ultrasonic waves tend to attenuate in the air, and the intensity of the scattered waves used in Non-Patent Document 1 tends to be low. For this reason, it is difficult for the technique in Non-Patent Document 1 to detect smaller flaws.

[0008] Furthermore, it is not easy to inspect a bonded assembly in which a first member and a second member are bonded with an adhesive.

[0009] The problem to be solved by the technology of this specification is to provide an ultrasonic inspection device and an ultrasonic inspection method that can measure a bonded structure having an adhesive layer in air with high accuracy. [Means for solving the problem]

[0010] An ultrasonic inspection device according to a first aspect inspects an object in air, the object having a first member, a second member, and an adhesive layer bonding the first member and the second member. The ultrasonic inspection device includes a transmitter that transmits ultrasonic waves to the object, a receiver that receives ultrasonic waves that have passed through the object, a frequency selector that selects the frequency of the ultrasonic waves transmitted by the transmitter in accordance with material information about the object, and a determination unit. The determination unit determines whether or not there are any non-bonded portions in the adhesive layer based on a transmitted wave amplitude index of the ultrasonic waves received by the receiver and a previously determined correspondence between the transmitted wave amplitude index of the ultrasonic waves and non-bonded portions. Furthermore, the relative value of the transmitted wave amplitude is used as the transmitted wave amplitude index.

[0011] This ultrasonic inspection device can use ultrasonic waves to inspect the presence or absence of non-bonded portions in the adhesive layer of an object bonded with an adhesive. The ultrasonic inspection device can also derive the size of the non-bonded portions in the adhesive layer of the object. The ultrasonic inspection device inspects the object in the air without contact. The ultrasonic inspection device can inspect the presence or absence of very small non-bonded portions of 1 mm or less. The transmitted wave amplitude index includes the relative value of the transmitted wave amplitude, the spatial distribution of the transmitted wave amplitude, and the amplitude transmittance. [Effects of the Invention]

[0012] The present specification provides an ultrasonic inspection device and an ultrasonic inspection method that can measure a bonded structure having an adhesive layer in air with high accuracy. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram of an inspection object A10 of an inspection device according to a first embodiment. [Figure 2] 1 is a schematic configuration diagram of an inspection device 100 according to a first embodiment. [Figure 3] FIG. 2 is a block diagram showing a control unit 130 of the inspection device 100 of the first embodiment. [Figure 4] 10 is a graph (part 1) illustrating the relationship between the thickness of the adhesive layer A13 and the amplitude transmittance. [Figure 5] 10 is a graph (part 2) illustrating the relationship between the thickness of the adhesive layer A13 and the amplitude transmittance. [Figure 6] 1 is a graph illustrating the relationship between void width and the relative value of transmitted wave amplitude. [Figure 7] 10 is a diagram showing the propagation state of ultrasonic waves when no voids exist in the inspection object A10. FIG. [Figure 8] 10 is a diagram showing the propagation state of ultrasonic waves when a void exists in an inspection object A10. FIG. [Figure 9] 10 is a graph showing the relationship between the frequency of ultrasonic waves incident on an inspection object A10 and the amplitude transmittance of ultrasonic waves transmitted through the inspection object A10. [Figure 10] 10 is a graph showing the relationship between the position and the relative value of the transmitted wave amplitude when a void V1 with a width of 0 mm-0.3 mm is present at the position of X=0 mm. [Figure 11] 10 is a graph showing the relationship between the position and the relative value of the transmitted wave amplitude when a void V1 with a width of 0.4 mm to 0.7 mm is present at the position of X=0 mm. [Figure 12] 10 is a graph showing the relationship between the position and the relative value of the transmitted wave amplitude when a void V1 with a width of 0.8 mm to 1.0 mm is present at the position of X=0 mm. [Figure 13] FIG. 2 is a diagram showing an air layer between the transmitting unit 110 side and the receiving unit 120 side in the first embodiment, expressed by a distributed constant circuit model. [Figure 14] 1 is a flowchart executed by the inspection device 100 of the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] Specific embodiments will be described below using an ultrasonic inspection device and an ultrasonic inspection method as examples, but the technology of this specification is not limited to these embodiments.

[0015] (First embodiment) 1. Inspection object Fig. 1 is a schematic diagram of an inspection object A10 of the inspection device of the first embodiment. As shown in Fig. 1, the inspection object A10 has a first member A11, a second member A12, and an adhesive layer A13. The inspection object A10 is a bonded body in which the first member A11 and the second member A12 are bonded together by the adhesive layer A13.

[0016] The first member A11 is, for example, a rigid body such as a metal, an alloy, a plastic, etc. The first member A11 has a surface A11a.

[0017] The second member A12 is made of a rigid body such as metal, alloy, plastic, etc. The second member A12 has a surface A12a.

[0018] The adhesive layer A13 is a layer that bonds at least a portion of the surface A11a of the first member A11 and at least a portion of the surface A12a of the second member A12. The inspection device of the first embodiment inspects whether or not there is a non-bonded portion in the adhesive layer A13 of the inspection object A10. The non-bonded portion includes voids and peeled portions. The non-bonded portion contains air, etc. The interface between the adhesive layer A13 and the non-bonded portion has an interface between the adhesive layer A13 and air.

[0019] At the time of inspection, the material and thickness of the first member A11 are known, the material and thickness of the second member A12 are known, and the material and thickness of the adhesive layer A13 are known.

[0020] 2. Inspection equipment FIG. 2 is a schematic diagram of the inspection device 100 of the first embodiment. The inspection device 100 inspects an inspection object A10 in the air without contact. Since ultrasonic waves propagate through the air, they are longitudinal waves. As shown in FIG. 2, the inspection device 100 has a transmitting unit 110, a receiving unit 120, a control unit 130, and a stage 140.

[0021] The transmitting unit 110 transmits ultrasonic waves to the object under test A10. The transmitting unit 110 converts an electrical signal input from the control unit 130 into ultrasonic waves, and irradiates the ultrasonic waves into the air and toward the object under test A10. The center frequency of the ultrasonic waves is, for example, 50 kHz or more and 2 MHz or less. The bandwidth of the ultrasonic waves is, for example, 10 kHz or more and 1000 kHz or less. The wavelength of the ultrasonic waves may be longer than the thickness of the object under test A10. The transmitting unit 110 is preferably capable of irradiating five or more burst waves. The transmitting unit 110 is connected to the control unit 130.

[0022] The receiving unit 120 receives ultrasonic waves that have passed through the inspection object A10. The receiving unit 120 receives ultrasonic waves that have passed through the inspection object A10 and propagated through the air, and converts the received ultrasonic waves into electrical signals. The receiving unit 120 transmits the converted electrical signals to the control unit 130. The receiving unit 120 is connected to the control unit 130.

[0023] The transmitter 110 and the receiver 120 are arranged facing each other at spatially separated positions. The object under test A10 is arranged between the transmitter 110 and the receiver 120. The ultrasonic waves emitted from the transmitter 110 are incident on the adhesive surface of the adhesive layer A13 of the object under test A10 perpendicularly or at an angle of 5° or less from perpendicular. In the first embodiment, the direction in which the ultrasonic waves are emitted is the Z axis.

[0024] The control unit 130 controls the transmitting unit 110 and the receiving unit 120, and determines whether or not there is an unbonded portion on the inspection target A10. The control unit 130 is connected to the transmitting unit 110 and the receiving unit 120. The control unit 130 inputs an electrical signal to the transmitting unit 110. The control unit 130 also receives an input of an electrical signal from the receiving unit 120.

[0025] The stage 140 supports the inspection object A10 and moves the inspection object A10 within an XY plane perpendicular to the Z axis. Therefore, the receiving unit 120 can inspect the inspection object A10 at each position within the XY plane of the inspection object A10. During measurement, the adhesive layer A13 of the inspection object A10 is positioned approximately parallel to the XY plane.

[0026] 3. Control System 3 is a block diagram showing the control unit 130 of the inspection device 100 of the first embodiment. The control unit 130 includes a transmitting / receiving unit 131, a material information acquiring unit 132, a frequency selecting unit 133, a determining unit 134, a storage unit 135, and an analyzing unit 136.

[0027] The transmitting / receiving unit 131 controls the transmitting unit 110 and the receiving unit 120. The transmitting / receiving unit 131 transmits an electrical signal to the transmitting unit 110 and receives an electrical signal from the receiving unit 120. The transmitting / receiving unit 131 transmits an electrical signal to the transmitting unit 110 to instruct the transmitting unit 110 to generate an ultrasonic wave of the frequency selected by the frequency selecting unit 133.

[0028] The material information acquisition unit 132 acquires material information of the inspection object A10. For example, the material information acquisition unit 132 acquires the materials and thicknesses of the first member A11, the second member A12, and the adhesive layer A13 by receiving input from the user. The material information acquisition unit 132 may acquire a data set of material information stored in advance in the storage unit 135. Alternatively, the material information acquisition unit 132 may receive a selection by the user from the material data stored in the storage unit 135. This allows the control unit 130 of the inspection device 100 to inspect the inspection object A10 based on the material information of the inspection object A10.

[0029] The frequency selection unit 133 selects the frequency of the ultrasonic waves to be transmitted by the transmission unit 110 in accordance with the material information of the inspection object A10. Specifically, the frequency selection unit 133 selects the frequency of the ultrasonic waves to be transmitted by the transmission unit 110 based on the thickness of the adhesive layer A13 acquired by the material information acquisition unit 132 and the correspondence between the thickness of the adhesive layer A13 and the amplitude transmittance of the ultrasonic waves stored in the memory unit 135. The frequency selected by the frequency selection unit 133 is a frequency suitable for inspecting the adhesive layer A13 of the inspection object A10. Details will be described later.

[0030] The determination unit 134 determines whether or not there is a non-bonded portion in the adhesive layer A13 by comparing the transmitted wave amplitude index of the ultrasonic wave received by the receiving unit 120 with a previously determined correspondence relationship between the transmitted wave amplitude index of the ultrasonic wave and the non-bonded portion. The transmitted wave amplitude index is, for example, a relative value of the transmitted wave amplitude or a spatial distribution of the transmitted wave amplitude. Furthermore, if there is a non-bonded portion in the adhesive layer A13 of the inspection target A10, the determination unit 134 derives the magnitude of the non-bonded portion in the adhesive layer A13 in a direction perpendicular to the incident direction of the ultrasonic wave.

[0031] The memory unit 135 stores a correspondence relationship between the frequency of the ultrasonic waves transmitted by the transmitter 110, the thickness of the adhesive layer A13, and the transmitted wave amplitude index. This correspondence relationship is used by the frequency selector 133 to select the frequency of the ultrasonic waves to be used for inspection. Here, the transmitted wave amplitude index is, for example, amplitude transmittance. The amplitude transmittance is the ratio of the amplitude of the transmitted ultrasonic waves received by the receiver 120 to the amplitude of the ultrasonic waves transmitted by the transmitter 110. The correspondence relationship between the film thickness of the adhesive layer A13 and the amplitude transmittance is affected by the type and thickness of the materials of the first member A11 and the second member A12. For this reason, the memory unit 135 stores various correspondence relationships.

[0032] FIG. 4 is a graph (part 1) illustrating the relationship between the thickness of the adhesive layer A13 and the amplitude transmittance. FIG. 5 is a graph (part 2) illustrating the relationship between the thickness of the adhesive layer A13 and the amplitude transmittance. The horizontal axis of FIGS. 4 and 5 represents the thickness of the adhesive layer A13. The vertical axis of FIGS. 4 and 5 represents the amplitude transmittance. As will be described later, the relationships in FIGS. 4 and 5 were derived using a distributed parameter circuit model.

[0033] 4 and 5, when an ultrasonic wave of a certain frequency is incident on an object A10 to be inspected, the amplitude transmittance reaches a very large maximum value at a certain thickness of the adhesive layer A13. This maximum value is called the resonant frequency.

[0034] The storage unit 135 also stores a correspondence relationship between the transmitted wave amplitude index and the non-bonded portion. This correspondence relationship is used by the determination unit 134 to determine the presence or absence of the non-bonded portion or the size of the non-bonded portion. The transmitted wave amplitude index is, for example, a relative value of the transmitted wave amplitude or a spatial distribution of the transmitted wave amplitude.

[0035] FIG. 6 is a graph illustrating the relationship between the width of a void (non-bonded portion) and the relative value of the transmitted wave amplitude. The width of the void refers to the size of the void in a direction perpendicular to the incident direction of the ultrasonic waves. In this case, the center of the void in the width direction is assumed to be on a straight line connecting the transmitting unit 110 and the receiving unit 120. The horizontal axis of FIG. 6 represents the width of the void. The vertical axis of FIG. 6 represents the relative value of the transmitted wave amplitude. The values ​​on the vertical axis in FIG. 6 are normalized with the value of the transmitted wave amplitude when no void is present as 1. This relationship is the result calculated using a finite element method simulation, which will be described later. The ultrasonic frequency used here was 400 kHz, which was selected as the optimal frequency from multiple frequencies prepared. The method for selecting the frequency will be described later.

[0036] As shown in Figure 6, as the void (non-bonded portion) grows larger from a state where there is no void, the relative value of the transmitted wave amplitude first increases, reaches a maximum value, and then decreases. Therefore, the presence or absence of a void and its size can be measured from the relative value of the transmitted wave amplitude. Because the frequency selection unit 133 selects the optimal frequency from multiple frequencies provided, it is possible to detect minute changes in the width of voids, such as those between 0.1 mm and 1.0 mm. The frequency selection method will be described later.

[0037] In Figure 6, when the void width is around 0.55 mm, the relative value of the transmitted wave amplitude is 1. In addition, in the region where the void width is between 0 mm and around 0.55 mm, the void width can take two values ​​relative to the relative value of the transmitted wave amplitude. However, as will be described later, the two can be distinguished from each other based on the spatial distribution of the relative value of the transmitted wave amplitude.

[0038] The analysis unit 136 calculates the relationship between the thickness of the adhesive layer A13 and the amplitude transmittance of the adhesive layer A13 from material information on the types and thicknesses of the materials of the first member A11, the second member A12, and the adhesive layer A13. Instead of the amplitude transmittance, other physical quantities related to the amplitude of transmitted ultrasonic waves may be used. A method for calculating the relationship between the thickness of the adhesive layer A13 and the amplitude transmittance will be described later.

[0039] 4.Non-adhesive area 4-1. When there is no non-adhesive area 7 is a diagram showing the propagation state of ultrasonic waves when no voids exist in the inspection target A10. The ultrasonic waves propagate through the first member A11 toward the receiving unit 120 in the direction of arrow W11. A portion of the ultrasonic waves traveling in the direction of arrow W11 enters the adhesive layer A13 and propagates toward the receiving unit 120 in the direction of arrow W12. The remaining portion of the ultrasonic waves traveling in the direction of arrow W11 is reflected at the interface between the surface A11a of the first member A11 and the surface of the adhesive layer A13 and propagates toward the transmitting unit 110 in the direction of arrow W14.

[0040] A portion of the ultrasonic waves traveling in the direction of arrow W12 enters the second member A12 and propagates in the direction of arrow W13 toward the receiving unit 120. The remainder of the ultrasonic waves traveling in the direction of arrow W12 is reflected at the interface between the surface A12a of the second member A12 and the surface of the adhesive layer A13 and propagates in the direction of arrow W15 toward the transmitting unit 110.

[0041] A portion of the ultrasonic waves traveling in the direction of arrow W13 propagates toward the receiving unit 120. The remaining portion of the ultrasonic waves traveling in the direction of arrow W13 is reflected at the interface between the surface A12b of the second member A12 and the air, and propagates toward the transmitting unit 110 in the direction of arrow W16.

[0042] In this way, ultrasonic waves are multiply reflected inside the bonded body bonded by the adhesive layer A13. Note that when ultrasonic waves are incident on the first member A11, some components of the ultrasonic waves are reflected.

[0043] 4-2. When there is a non-adhesive area 8 is a diagram showing the propagation state of ultrasonic waves when a void exists in the inspection object A10. In this case, the ultrasonic waves are also multiply reflected inside the inspection object A10.

[0044] 8, a void V1 exists at the interface between the surface A11a of the first member A11 and the surface of the adhesive layer A13. Because the ultrasonic waves are diffracted at the edge of the void V1, a component of the ultrasonic waves detouring around the void V1 is generated. In this case, as shown by arrows W22 and W25, the ultrasonic waves detouring around the void V1.

[0045] In this way, the ultrasonic waves travel around the void V1, which increases the propagation distance of the ultrasonic waves. This corresponds to the thickness of the adhesive layer A13 increasing in Figures 4 and 5. This changes the way the multiply reflected ultrasonic waves interfere.

[0046] It is assumed that this wraparound causes the ultrasonic waves to propagate 5 μm further through the adhesive layer A13. In Figure 4, when 400 kHz ultrasonic waves are used, the amplitude transmittance at a thickness of 205 μm is greater than that at a thickness of 200 μm. When the thickness of the adhesive layer A13 is 200 μm, if void V1 is not present, an amplitude transmittance of 200 μm is output, and if void V1 is present, an amplitude transmittance of 205 μm is output. Therefore, the presence or absence of void V1 can be detected. Furthermore, the larger the width of void V1, the greater the change in the ultrasonic propagation distance. Accordingly, the amplitude transmittance also changes. Based on this change, the width of void V1 can be measured from the amplitude transmittance.

[0047] The closer the frequency of the ultrasonic waves is to the resonant frequency, the greater the change in amplitude transmittance caused by the void V1. In other words, the closer the frequency of the ultrasonic waves is to the resonant frequency, the more accurate the detection of the presence or absence of the void V1 and the measurement of the width of the void V1 become. In addition, since the frequency of the ultrasonic waves transmitted by the transmitting unit 110 is close to the resonant frequency, the signal-to-noise ratio itself is large.

[0048] 4-3. Resonance As shown in Figures 7 and 8, resonance occurs within a material where multiple reflections occur. In other words, there are conditions where the transmitting ultrasonic waves constructively interact with each other. In such a case, the presence of a void V1 changes the amplitude transmittance, and the amplitude transmittance also changes depending on the width of the void V1. By utilizing this, ultrasonic inspection can be performed with high accuracy. For this reason, the inspection device 100 of the first embodiment performs ultrasonic inspection using a frequency close to the resonance frequency.

[0049] 4-4. Frequency Selection The frequency selection unit 133 selects a frequency suitable for the inspection. For example, assume that the thickness of the adhesive layer A13 of the inspection object A10 is 200 μm. Figures 4 and 5 plot the amplitude transmittance when ultrasonic waves of 100 kHz, 200 kHz, 300 kHz, 400 kHz, 500 kHz, 600 kHz, 700 kHz, and 800 kHz are irradiated onto the inspection object A10.

[0050] Fig. 9 is a graph showing the relationship between the frequency of ultrasonic waves incident on the inspection object A10 and the amplitude transmittance of ultrasonic waves passing through the inspection object A10. The horizontal axis of Fig. 9 represents the frequency of ultrasonic waves incident on the inspection object A10. The vertical axis of Fig. 9 represents the amplitude transmittance of ultrasonic waves passing through the inspection object A10.

[0051] The frequency selection unit 133 determines a frequency that resonates near the thickness of the adhesive layer A13 of the inspection object A10 as a frequency suitable for inspection based on the relationships shown in Figures 4 and 5. For example, the frequency selection unit 133 selects a frequency having a peak value in a range of 5 µm to 80 µm greater than the film thickness of the adhesive layer A13. Preferably, the frequency selection unit 133 selects a frequency having a peak value in a range of 10 µm to 50 µm greater than the film thickness of the adhesive layer A13. Alternatively, the frequency selection unit 133 may select a frequency having a peak value in a range of 30 µm or less greater than the film thickness of the adhesive layer A13.

[0052] When there are multiple candidate frequencies, the frequency selection unit 133 may freely select from among the candidate frequencies. Alternatively, the frequency with the highest amplitude transmittance may be selected from among the candidate frequencies. In FIG. 9, the amplitude transmittance is highest at 400 kHz. In this case, 400 kHz is selected.

[0053] 4-5. Size of non-adhesive area Next, the relationship between the size of the non-adhesive portion and the transmitted ultrasonic waves will be described, assuming that the thickness of the adhesive layer A13 is 200 μm.

[0054] Figure 10 is a graph showing the relationship between the position and the relative value of the transmitted wave amplitude when a void V1 with a width of 0 mm to 0.3 mm is located at the position of X = 0 mm. Figure 11 is a graph showing the relationship between the position and the relative value of the transmitted wave amplitude when a void V1 with a width of 0.4 mm to 0.7 mm is located at the position of X = 0 mm. Figure 12 is a graph showing the relationship between the position and the relative value of the transmitted wave amplitude when a void V1 with a width of 0.8 mm to 1.0 mm is located at the position of X = 0 mm. These graphs were obtained using the finite element method simulation described below. The ultrasonic frequency used here was 400 kHz, which was selected as the optimal frequency for inspection. Here, the size of the void V1 refers to the length of the void V1 in the X-axis direction.

[0055] 10 to 12, the horizontal axis represents the position in the X direction. In FIGS. 10 to 12, the vertical axis represents the relative value of the transmitted wave amplitude. In FIGS. 10 to 12, the X direction is an arbitrary direction in the XY plane. In FIGS. 10 to 12, the central position where void V1 exists is set to X=0. The values ​​on the vertical axis are normalized by the value of the amplitude transmittance when a width of 0 mm, i.e., when void V1 does not exist.

[0056] As shown in FIG. 10, when no void V1 exists, the relative value of the normalized transmitted wave amplitude is approximately 1 within a range of 5 mm or less from the center position to be measured.

[0057] As shown in FIGS. 10 and 11, when the size of the void V1 is 0.1 mm or more and 0.4 mm or less, the relative value of the transmitted wave amplitude increases at the center position (X=0) of the void V1 and its periphery.

[0058] 11, when the size of the void V1 is between 0.5 mm and 0.7 mm, the relative value of the transmitted wave amplitude decreases at a position approximately 1 mm away from the center of the void V1. Also, the relative value of the transmitted wave amplitude at the center of the void V1 is greater than the relative value of the transmitted wave amplitude at a position approximately 1 mm away from the center of the void V1.

[0059] As shown in FIG. 12, when the size of the void V1 is 0.8 mm or more and 1.0 mm or less, the relative value of the transmitted wave amplitude is significantly small at the center position of the void V1 and at a position about 2 mm away from the center.

[0060] Thus, there is a correlation between the size of the void V1 in the X direction and the spatial distribution of the relative values ​​of the transmitted wave amplitude. Therefore, by comparing the size of the void V1 in the X direction with the spatial distribution of the relative values ​​of the transmitted wave amplitude, the inspection device 100 can calculate the size of the void V1.

[0061] The stage 140 is movable within the XY plane. Therefore, the inspection device 100 can inspect the adhesive layer A13 of the inspection target A10 at each point within the XY plane. Therefore, the inspection device 100 can create the spatial distribution profile of the relative values ​​of the transmitted wave amplitude shown in FIGS. 10 to 12.

[0062] The determination unit 134 calculates the size of the void V1 by comparing the relationship between the size of the void V1 and the spatial distribution of the relative value of the transmitted wave amplitude stored in the memory unit 135 with the relationship between the spatial distribution of the transmitted wave amplitude received by the receiving unit 120. The memory unit 135 stores data on the size of the void V1 in increments of 0.1 mm, for example, as shown in Figures 10 to 12. The determination unit 134 can interpolate the discrete data as appropriate. The interpolation method may be linear interpolation or another interpolation method.

[0063] The memory unit 135 stores the correspondence between the frequency of the ultrasonic waves transmitted by the transmitter, the thickness of the adhesive layer, and the transmitted wave amplitude index as shown in Figures 4, 5, and 9, and the correspondence between the transmitted wave amplitude index and the non-adhesive portion as shown in Figures 6 and 10 to 12.

[0064] 5. Calculation of the relationship between adhesive layer thickness and amplitude transmittance The method of calculating the resonance frequency executed by the analysis unit 136 will be described below. The analytical formula used to calculate the complex transmittance will be described below. The complex transmittance is calculated using an analytical formula derived based on a distributed constant circuit model. The distributed constant circuit model is a model that expresses the relationship between input and output signals in a circuit element using formulas called S parameters that represent the reflection, transmission, and propagation characteristics of the circuit element. The matrix S, which is an S parameter, is given by the following formula (1).

[0065]

number

[0066] 13 is a diagram showing a distributed constant circuit model representing the area between the air layer on the transmitting unit 110 side and the air layer on the receiving unit 120 side in the first embodiment. As shown in FIG. 13, the S parameter is S 12 , S2, S 23 , S3, S 34 , S4, S 45 This is a circuit model in which the elements are connected in series in the order of S 12is the S parameter component of the interface between the air layer and the first member A11, S2 is the S parameter component of the first member A11, and S 23 is the S parameter component of the interface between the first member A11 and the adhesive layer A13, S3 is the S parameter component of the adhesive layer A13, and S 34 is the S parameter component of the interface between the adhesive layer A13 and the second member A12, S4 is the S parameter component of the second member A12, and S 45 is the S parameter component of the interface between the second member A12 and the air layer.

[0067] The S parameters of each layer and interface are expressed by the following equations (2) and (3).

[0068]

number

number

[0069] In equation (2), c n is the longitudinal wave velocity of ultrasound in the nth layer, t n is the thickness of the nth layer, where c n is expressed by the following formula (4).

[0070]

number

[0071] In equation (4), E n is the Young's modulus of the nth layer, ρ n is the density of the nth layer, ν n is the Poisson's ratio of the nth layer. As shown in equation (4), if the density and Poisson's ratio of the material are known, Young's modulus can be calculated from the longitudinal wave velocity.

[0072] Also, in equation (3), Γ (n+1) n indicates the reflectivity when an ultrasonic wave propagates from the nth layer to the (n+1)th layer, and Tr (n+1) nindicates the transmittance when an ultrasonic wave propagates from the nth layer to the (n+1)th layer.

[0073] Gamma (n+1) n ,Tr (n+1) n are expressed by the following equations (5) and (6).

[0074]

number

number

[0075] In equations (5) and (6), Z n is the acoustic impedance of the nth layer and is expressed by the following equation (7).

[0076]

number

[0077] By converting the S parameters into T parameters, the cascade connection can be expressed simply by matrix multiplication. The conversion from S parameters to T parameters is expressed by Equation (8). In addition, the overall T parameters (T all ) is expressed by equation (9).

[0078]

number

number

[0079] In equation (9), T n is the T parameter of the nth layer, and T n (n+1) is the T parameter at the interface between the nth layer and the (n+1)th layer.

[0080] The T parameter T calculated using equation (9) allis converted back into S parameters, and the overall S parameters S from the transmitter 110 to the receiver 120 are obtained. all is calculated. T all From S all The conversion to is expressed by equation (10).

[0081]

number

[0082] As can be seen by comparing with equation (3), S all Ingredients S all 21 is the complex transmittance in the section from the air layer on the transmitting unit 110 side to the air layer on the receiving unit 120 side. In this way, the analytical expression of the complex transmittance Tr(f) by the distributed constant circuit model is obtained. all Ingredients S all 11 corresponds to the complex reflectance.

[0083] The amplitude transmittance in Figures 4 and 5 is S all 4 and 5 for various materials and thicknesses. The analysis unit 136 stores the calculation results in the memory unit 135.

[0084] Furthermore, the analysis unit 136 calculates the relationship between the frequency and amplitude transmittance of ultrasonic waves in the adhesive layer A13 of a certain thickness, as shown in Fig. 9. For example, if the thickness of the adhesive layer A13 is 200 µm, the amplitude transmittance of each frequency at 200 µm can be extracted.

[0085] 6. Testing Method 14 is a flowchart executed by the inspection device 100 of the first embodiment. First, the material information acquisition unit 132 acquires material information of the inspection target A10 (S101). The material information acquisition unit 132 acquires, for example, information on the materials and thicknesses of the first member A11, the second member A12, and the adhesive layer A13.

[0086] Next, the frequency selection unit 133 selects the frequency of the ultrasonic waves to be irradiated onto the inspection target A10 in accordance with the material information of the inspection target A10 (S102). The frequency selection unit 133 selects the frequency of the ultrasonic waves corresponding to the thickness of the adhesive layer A13. Specifically, as described above, the frequency selection unit 133 refers to the memory unit 135 and selects a frequency that resonates near the thickness of the adhesive layer A13 based on the relationship between the thickness of the adhesive layer A13 and the amplitude transmittance as shown in FIGS. 4 and 5. The frequency selection unit 133 may also refer to the memory unit 135 and select the frequency of the ultrasonic waves to be transmitted by the transmission unit 110 based on the relationship between the frequency of the ultrasonic waves and the amplitude transmittance of the ultrasonic waves transmitted through the inspection target A10 as shown in FIG. 9. As described above, the frequency selection unit 133 selects the frequency with the largest amplitude transmittance from among multiple frequencies.

[0087] Next, the transmitting unit 110 irradiates the inspection object A10 in the air with ultrasonic waves of the frequency selected by the frequency selecting unit 133, and the receiving unit 120 receives the transmitted ultrasonic waves that have transmitted through the inspection object A10 (S103). The receiving unit 120 transmits information about the received transmitted ultrasonic waves to the transmitting / receiving unit 131 of the control unit 130. The determining unit 134 associates the XY coordinates of the inspection object A10 with the information about the transmitted ultrasonic waves received by the transmitting / receiving unit 131 and stores them in the memory unit 135.

[0088] Next, it is determined whether measurement has been completed at all positions within the XY plane of the inspection object A10 (S104). If measurement has been completed at all XY coordinates to be inspected (S104: Yes), the process proceeds to S105. If measurement has not been completed at all XY coordinates to be inspected (S104: No), the process returns to S103.

[0089] In S105, the determination unit 134 compares the spatial distribution of the transmitted wave amplitude of the ultrasonic waves received by the receiving unit 120 with the relationship between the spatial distribution of the transmitted wave amplitude of the ultrasonic waves stored in the memory unit 135 and the size of the void V1 (FIGS. 10 to 12). At this time, the determination unit 134 normalizes the measured transmitted wave amplitude of the ultrasonic waves. Then, if a void V1 is present, the determination unit 134 derives the size of the void V1 in a direction perpendicular to the incident direction of the ultrasonic waves.

[0090] The determination unit 134 can also determine that a void V1 does not exist if the absolute value of the difference between the measured transmitted wave amplitude of the ultrasonic wave and the transmitted wave amplitude of the ultrasonic wave stored in the storage unit 135 is equal to or less than a predetermined threshold within a predetermined spatial range. Here, the predetermined spatial range refers to, for example, the XY coordinates that are the object of the determination of the presence or absence of the void V1 and an area within 5 mm from those coordinates.

[0091] The judgment unit 134 can also determine that a void V1 exists if the absolute value of the difference between the measured transmitted wave amplitude of the ultrasonic wave and the transmitted wave amplitude of the ultrasonic wave stored in the memory unit 135 within a predetermined spatial range is greater than a predetermined threshold value.

[0092] 7. Effects of the First Embodiment The inspection device 100 of the first embodiment can use ultrasound to inspect the presence or absence of non-bonded portions in the adhesive layer A13 of the inspection object A10, which is bonded with an adhesive. The inspection device 100 can also derive the size of the non-bonded portions in the adhesive layer A13 of the inspection object A10. The inspection device 100 inspects the inspection object A10 in the air without contact. The inspection device 100 can inspect the presence or absence of very small non-bonded portions of about 0.1 mm.

[0093] Since the inspection device 100 irradiates the inspection object A10 with ultrasonic waves at a frequency close to the resonant frequency, the change in the transmitted wave amplitude caused by the void V1 is large. In other words, the inspection device 100 can measure the presence or absence of the void V1 and the width of the void V1 with high accuracy. In addition, the signal-to-noise ratio itself is also high.

[0094] 8. Variations 8-1. Comparison method The determination unit 134 of the inspection device 100 of the first embodiment determines the presence or absence of a void V1 based on the absolute value of the difference between the measured transmitted wave amplitude of the ultrasonic wave (measured amplitude value) and the transmitted wave amplitude of the ultrasonic wave (reference amplitude value) stored in the storage unit 135. To determine the presence or absence of the void V1, the ratio between the measured amplitude value and the reference amplitude value may be used.

[0095] For example, if the measured amplitude value relative to the reference amplitude value is equal to or greater than a predetermined first threshold and equal to or less than a predetermined second threshold, the determination unit 134 determines that the void V1 does not exist in the adhesive layer A13. If the measured amplitude value relative to the reference amplitude value is smaller than the predetermined first threshold or larger than the predetermined second threshold, the determination unit 134 determines that the void V1 exists in the adhesive layer A13.

[0096] Alternatively, any other method may be used as long as it is possible to compare the magnitude relationship between the measured amplitude value and the reference amplitude value.

[0097] Alternatively, the determination unit 134 may use a cross-correlation coefficient, which is a product of the spatial distribution of the relative values ​​of the measured transmitted wave amplitudes and the spatial distribution of the transmitted wave amplitudes of the void V1 stored in the storage unit 135. The determination unit 134 calculates the cross-correlation coefficient between the spatial distribution of the transmitted wave amplitudes of various voids V1 stored in the storage unit 135 and the spatial distribution of the relative values ​​of the measured transmitted wave amplitudes, and determines the width of the void V1 when the cross-correlation coefficient is maximum as the width of the measured void V1.

[0098] 8-2.Analysis section The control unit 130 does not need to have the analysis unit 136. It is sufficient that the memory unit 135 has already analyzed data. Also, instead of using the data stored in the memory unit 135, analysis can be performed using an analytical formula for each test. However, in this case, the processing time will be longer.

[0099] 8-3.Analytical formula The analysis unit 136 may use an analytical formula other than the distributed parameter circuit model. For example, the complex transmittance may be calculated from a propagation formula for sound pressure and particle velocity in each layer and a relational formula for sound pressure and particle velocity between layers.

[0100] 8-4. Frequency selection section The frequency selection unit 133 may select a frequency having a peak value in a range of 5 μm to 80 μm smaller than the film thickness of the adhesive layer A13. Preferably, the frequency selection unit 133 selects a frequency having a peak value in a range of 10 μm to 50 μm smaller than the film thickness of the adhesive layer A13. Alternatively, the frequency selection unit 133 may select a frequency having a peak value in a range of 30 μm to 30 μm smaller than the film thickness of the adhesive layer A13.

[0101] Alternatively, the frequency selection unit 133 may select a frequency having a peak value within a range from a thickness value that is 80 μm or less thinner than the film thickness of the adhesive layer A13 to a thickness value that is 80 μm or less thicker than the film thickness of the adhesive layer A13.

[0102] 8-5.Moving the transmitter and receiver In the first embodiment, the stage 140 moves within the XY plane. Instead of the stage 140 moving within the XY plane, the transmitter 110 and the receiver 120 may have a mechanism for moving within the XY plane.

[0103] 8-6.Transmitter The transmitting unit 110 may have a plurality of transmitting units that emit ultrasound waves of different frequencies. The transmitting / receiving unit 131 can select the frequency of the ultrasound waves that it actually emits from a wide range of frequencies.

[0104] 8-7. Flow The determination unit 134 may use the value of the transmitted wave amplitude at the XY coordinates to be measured instead of the spatial distribution of the transmitted wave amplitude. The determination unit 134 determines whether or not there is a non-bonded portion in the adhesive layer A13 by comparing the transmitted wave amplitude index of the received ultrasonic wave with a correspondence relationship between the transmitted wave amplitude index of the ultrasonic wave and the non-bonded portion that has been determined in advance. For example, the determination unit 134 compares the transmitted wave amplitude of the ultrasonic wave received by the receiving unit 120 with the relationship between the transmitted wave amplitude of the ultrasonic wave and the width of the void V1 (FIG. 6) stored in the memory unit 135. At this time, the measured transmitted wave amplitude of the ultrasonic wave is normalized.

[0105] If the absolute value of the difference between the measured transmitted wave amplitude of the ultrasonic wave and the transmitted wave amplitude of the ultrasonic wave stored in the storage unit 135 is equal to or less than a predetermined threshold, it is determined that the void V1 does not exist.

[0106] However, for example, as shown in FIG. 6, if the width of the void V1 is about 0.55 mm, it is difficult to detect the void V1.

[0107] If the absolute value of the difference between the measured transmitted wave amplitude of the ultrasonic wave and the transmitted wave amplitude of the ultrasonic wave stored in the storage unit 135 is greater than a predetermined threshold, it is determined that a void V1 exists.

[0108] 8-8. Relative value of transmitted wave amplitude In the first embodiment, the transmitted wave amplitude is normalized. However, the transmitted wave amplitude does not have to be normalized. If the measured transmitted wave amplitude can be compared with pre-stored data, normalization is not necessary. By setting an appropriate threshold, the inspection device 100 can measure the void V1.

[0109] 8-9.Multiple adhesive layers The inspection object A10 of the first embodiment has one adhesive layer A13. The inspection device 100 can also inspect an inspection object having multiple adhesive layers. The inspection device 100 can at least inspect the position of the non-adhesive portion in the XY plane.

[0110] 8-10.Storage section The storage unit 135 can store other data as appropriate, such as information relating to transmitted ultrasound acquired by the receiving unit 120 and data derived by the determining unit 134 .

[0111] 8-11. Combination The above modifications may be freely combined.

[0112] (simulation) 1. Simulation method Simulations were performed using the finite element method, and the relationships shown in Figures 6, 10, 11, and 12 were obtained. A steel plate with a thickness of 1.2 mm was used as the first member A11. A steel plate with a thickness of 1.2 mm was used as the second member A12. An adhesive with a thickness of 200 μm was used as the adhesive layer A13. A void V1 was placed at the interface between the first member A11 and the adhesive layer A13. The sizes of the first member A11, the second member A12, and the adhesive layer A13 in the X-axis and Y-axis directions were set to 60 mm. The first member A11, the second member A12, and the adhesive layer A13 were all rectangular parallelepiped shapes.

[0113] The transducer diameter of the transmitting unit 110 and the receiving unit 120 was set to 13 mm, and the radius of curvature was set to 25 mm. The frequency of the ultrasonic waves transmitted by the transmitting unit 110 was set to 400 kHz. The ultrasonic waves transmitted by the transmitting unit 110 were burst waves with a wave number of 20. The positions of the transmitting unit 110 and the receiving unit 120 in the X direction were set in 1 mm increments from -5 mm to 5 mm.

[0114] In the simulation, the center of void V1 was placed at X = 0 mm. The size of void V1 in the X direction was set from 0 mm to 1.0 mm in 0.1 mm increments. The size of void V1 in the X direction is sometimes simply referred to as the size of void V1.

[0115] Table 1 shows the values ​​of the longitudinal wave velocity, shear wave velocity, and density for the air, steel plate, and adhesive layer used in the simulation.

[0116] [Table 1]

[0117] 2. Simulation Results 2-1.Void As shown in FIG. 6, the relative value of the transmitted wave amplitude increases as the void V1 increases from a state where there is no void V1, reaches a peak value, and then decreases.

[0118] 10 and 11, when the size of the void V1 is approximately 0.4 mm or less, the relative value of the transmitted wave amplitude is large and reaches its maximum value at the position X = 0 mm. In addition, the relative value of the transmitted wave amplitude is greater than 1 around the center position of the void V1.

[0119] As shown in Figure 11, when the size of the void V1 is 0.5 mm, the relative value of the transmitted wave amplitude is large and reaches its maximum value at the position X = 0 mm. Also, around the center position of the void V1, the relative value of the transmitted wave amplitude is smaller than 1. In other words, around the center position of the void V1, the relative value of the transmitted wave amplitude reaches its minimum value. For example, the relative value of the transmitted wave amplitude reaches its minimum value around X = ±0.1 mm.

[0120] As shown in Figures 11 and 12, when the size of the void V1 is between 0.6 mm and 0.8 mm, the relative value of the transmitted wave amplitude at the position X = 0 mm is 1 or less and is a maximum value. The relative value of the transmitted wave amplitude is smaller than 1 around the center position of the void V1. That is, the relative value of the transmitted wave amplitude is a minimum around the center position of the void V1. For example, the relative value of the transmitted wave amplitude is a minimum around X = ±0.1 mm. Furthermore, when the size of the void V1 is 0.8 mm, the relative value of the transmitted wave amplitude is smaller than 1 around X = ±0.2 mm. That is, the larger the size of the void V1, the more the relative value of the transmitted wave amplitude is affected at positions farther from the center position of the void V1.

[0121] As shown in Figure 12, when the size of void V1 is between 0.9 mm and 1.0 mm, the relative value of the transmitted wave amplitude is minimum and extremely small at the position X = 0 mm. The relative value of the transmitted wave amplitude at the positions X = ±1 mm is small, about 0.3. The relative value of the transmitted wave amplitude is smaller than 1 near X = ±0.2 mm.

[0122] 10 to 12, there is a correlation between the size of the void V1 and the spatial distribution of the relative value of the transmitted wave amplitude. Therefore, by comparing the spatial distribution of the measured ultrasonic transmitted wave amplitude with pre-stored data on the spatial distribution of the transmitted wave amplitude, the size of the void V1 can be derived.

[0123] Furthermore, as shown in Fig. 9, there is a correlation between the presence or absence of void V1 and the amplitude transmittance. Therefore, by comparing the measured transmitted wave amplitude of the ultrasonic wave with pre-stored transmitted wave amplitude data, the size of the void V1 can be derived.

[0124] (Addendum) An ultrasonic inspection device according to a first aspect inspects an object in air, the object having a first member, a second member, and an adhesive layer bonding the first member and the second member. The ultrasonic inspection device includes a transmitter that transmits ultrasonic waves to the object, a receiver that receives ultrasonic waves that have passed through the object, a frequency selector that selects the frequency of the ultrasonic waves transmitted by the transmitter in accordance with material information about the object, and a determination unit. The determination unit determines whether or not there are any non-bonded portions in the adhesive layer based on a transmitted wave amplitude index of the ultrasonic waves received by the receiver and a previously determined correspondence between the transmitted wave amplitude index of the ultrasonic waves and non-bonded portions.

[0125] In the ultrasonic inspection device according to the second aspect, the determining unit uses a relative value of the transmitted wave amplitude as the transmitted wave amplitude index.

[0126] In the ultrasonic inspection device according to the third aspect, the determining unit uses the spatial distribution of the transmitted wave amplitude as the transmitted wave amplitude index, and derives the magnitude of the ultrasonic wave in the non-bonded portion in a direction perpendicular to the incident direction of the ultrasonic wave.

[0127] In the ultrasonic inspection device according to the fourth aspect, the frequency selection section selects the frequency of the ultrasonic waves to be transmitted by the transmission section based on the correspondence relationship between the thickness of the adhesive layer and the amplitude transmittance of the ultrasonic waves.

[0128] The ultrasonic inspection device according to the fifth aspect includes a storage unit that stores a correspondence relationship between the transmitted wave amplitude index and the non-bonded portion.

[0129] The ultrasonic inspection device according to the sixth aspect includes a memory unit that stores a correspondence relationship between the frequency of the ultrasonic waves transmitted by the transmitter, the thickness of the adhesive layer, and the transmitted wave amplitude index.

[0130] In the ultrasonic inspection method of the seventh aspect, material information of an object to be inspected, which has a first member, a second member, and an adhesive layer that bonds the first member and the second member, is obtained. The frequency of ultrasonic waves to be irradiated onto the object to be inspected is selected according to the material information of the object to be inspected. Ultrasonic waves of the selected frequency are irradiated onto the object to be inspected in the air, and ultrasonic waves that have passed through the object to be inspected are received. The presence or absence of non-bonded portions in the adhesive layer is determined by comparing a transmitted wave amplitude index of the received ultrasonic waves with a correspondence relationship between the transmitted wave amplitude index of the ultrasonic waves and a previously determined correspondence relationship between the non-bonded portions.

[0131] In the ultrasonic inspection method according to the eighth aspect, the spatial distribution of the transmitted wave amplitude is used as the transmitted wave amplitude index, and the magnitude in the direction perpendicular to the incident direction of the ultrasonic wave in the non-bonded portion is derived. [Explanation of symbols]

[0132] 100...Inspection equipment 110...Transmitter 120...Receiver 130...Control unit 131...Transmitter / receiver 132…Material information acquisition department 133...Frequency selection unit 134...judgment department 135...Storage section 136…Analysis Department 140...Stage

Claims

1. An ultrasonic inspection device for inspecting an object to be inspected in air, the object having a first member, a second member, and an adhesive layer that bonds the first member and the second member, a transmitter that transmits ultrasonic waves to the object to be inspected; a receiving unit that receives ultrasonic waves transmitted through the inspection object; a frequency selection unit that selects a frequency of the ultrasonic waves to be transmitted by the transmission unit in accordance with material information of the object to be inspected; A judgment unit; and The determination unit a transmitted wave amplitude index of the ultrasonic wave received by the receiving unit; From the correspondence relationship between the transmitted wave amplitude index of the ultrasonic wave and the non-bonded portion obtained in advance, determining whether or not the adhesive layer has a non-adhesive portion; The relative value of the transmitted wave amplitude is used as the transmitted wave amplitude index.

1. An ultrasonic inspection device comprising:

2. An ultrasonic inspection device for inspecting an object to be inspected in air, the object having a first member, a second member, and an adhesive layer that bonds the first member and the second member, a transmitter that transmits ultrasonic waves to the object to be inspected; a receiving unit that receives ultrasonic waves that have passed through the object to be inspected; a frequency selection unit that selects a frequency of the ultrasonic waves to be transmitted by the transmission unit in accordance with material information of the object to be inspected; A judgment unit; and The determination unit a transmitted wave amplitude index of the ultrasonic wave received by the receiving unit; From the correspondence relationship between the transmitted wave amplitude index of the ultrasonic wave and the non-bonded portion obtained in advance, determining whether or not the adhesive layer has a non-adhesive portion; The frequency selection unit selecting a frequency of the ultrasonic waves to be transmitted by the transmitting unit based on the correspondence relationship between the thickness of the adhesive layer and the amplitude transmittance of the ultrasonic waves; 1. An ultrasonic inspection device comprising:

3. 3. The ultrasonic inspection device according to claim 2, The determination unit The relative value of the transmitted wave amplitude is used as the transmitted wave amplitude index.

1. An ultrasonic inspection device comprising:

4. 3. The ultrasonic inspection device according to claim 2, The determination unit The spatial distribution of the transmitted wave amplitude is used as the transmitted wave amplitude index, Deriving the magnitude of the ultrasonic wave in the non-bonded portion in a direction perpendicular to the incident direction thereof.

1. An ultrasonic inspection device comprising:

5. The ultrasonic inspection device according to any one of claims 1 to 4, A storage unit is included, The storage unit a correspondence relationship between the transmitted wave amplitude index and the non-bonded portion is stored; 1. An ultrasonic inspection device comprising:

6. The ultrasonic inspection device according to any one of claims 2 to 4, A storage unit is included, The storage unit The frequency of the ultrasonic waves transmitted by the transmitting unit; the thickness of the adhesive layer; the transmitted wave amplitude index; Memorize the correspondence between 1. An ultrasonic inspection device comprising:

7. acquiring material information of an object to be inspected, the object having a first member, a second member, and an adhesive layer that bonds the first member and the second member; selecting a frequency of ultrasonic waves to be irradiated onto the inspection object in accordance with material information of the inspection object; irradiating the object to be inspected in the air with ultrasonic waves of a selected frequency and receiving the ultrasonic waves that have passed through the object to be inspected; determining whether or not the adhesive layer has a non-bonded portion by comparing a transmitted wave amplitude index of the received ultrasonic wave with a correspondence relationship between the transmitted wave amplitude index of the ultrasonic wave and a non-bonded portion that has been determined in advance; The relative value of the transmitted wave amplitude is used as the transmitted wave amplitude index. An ultrasonic inspection method comprising:

8. acquiring material information of an object to be inspected, the object having a first member, a second member, and an adhesive layer that bonds the first member and the second member; selecting a frequency of ultrasonic waves to be irradiated onto the inspection object in accordance with material information of the inspection object; irradiating the object to be inspected in the air with ultrasonic waves of a selected frequency and receiving the ultrasonic waves that have passed through the object to be inspected; determining whether or not the adhesive layer has a non-bonded portion by comparing a transmitted wave amplitude index of the received ultrasonic wave with a correspondence relationship between the transmitted wave amplitude index of the ultrasonic wave and a non-bonded portion that has been determined in advance; The frequency of the ultrasonic waves to be transmitted is selected based on the correspondence relationship between the thickness of the adhesive layer and the amplitude transmittance of the ultrasonic waves. An ultrasonic inspection method comprising:

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