Ultrasonic inspection device and ultrasonic inspection method

Abstract

To perform inspection of an internal state of an object with high accuracy even when gain adjustment is carried out according to signal intensity of reflected waves or the like.SOLUTION: An ultrasonic inspection device 11 comprises: an ultrasonic probe 17 including a piezoelectric element 13 for transmitting and receiving ultrasonic waves and an acoustic lens 15; a gain setting unit 23 that sets a gain for amplifying reflected waves; a reference wave information acquisition unit 25 that acquires, as reference wave information relating to a lens echo generated in the acoustic lens 15, a reflected wave amplified using the gain set by the gain setting unit 23 when an output ultrasonic wave is transmitted to a test environment where no object 19 is present; an interference wave information acquisition unit 27 that acquires, as interference wave information including internal state information of the object 19, a reflected wave amplified using the gain set by the gain setting unit 23 when the output ultrasonic wave is transmitted to an inspection environment where the object 19 is present; and an information processing unit 29 that obtains internal state information of the object 19 on the basis of the interference wave information and the reference wave information.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic inspection apparatus and an ultrasonic inspection method for inspecting the internal state of a test object such as a semiconductor wafer using ultrasonic waves. [Background technology]

[0002] Patent Document 1 discloses an invention of an ultrasonic inspection device that uses ultrasonic waves to inspect the internal state of a subject. The ultrasonic inspection device according to Patent Document 1 comprises an oscillator that outputs high-frequency pulses, a conversion element that outputs ultrasonic waves in response to the high-frequency pulses from the oscillator and outputs an electrical signal proportional to the ultrasonic waves input from the object under inspection, and an acoustic lens that supports the conversion element and focuses the ultrasonic waves. In the ultrasonic inspection device disclosed in Patent Document 1, before an ultrasonic inspection of a subject is performed, data of a lens echo generated by ultrasonic waves traveling back and forth within an acoustic lens is stored in a storage unit. When an ultrasonic inspection of a subject is performed, the lens echo data stored in the storage unit at the same time is subtracted from the obtained electrical signal data. According to the ultrasonic inspection device disclosed in Patent Document 1, highly accurate inspection results can be obtained in which the lens echo (noise) generated within the acoustic lens is cancelled out.

[0003] Furthermore, Patent Document 2 discloses an invention of an ultrasonic inspection device that amplifies the signal strength by multiplying the reflected wave by a predetermined gain value in order to capture even a small reflection intensity signal, even if the reflection intensity signal includes the intensity of the reflected wave returned from the subject, even if the reflection intensity signal is small. Here, even if the intensity of the emitted wave is the same, the intensity of the reflected wave varies depending on conditions such as the material and thickness of the object under test. To address this issue, Patent Document 2 also describes performing gain adjustment so as to lower the gain value when the signal intensity of the reflected wave exceeds a predetermined threshold. According to the ultrasonic inspection device of Patent Document 2, highly accurate inspection results can be obtained without missing even minute reflection intensity signals. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 4-040362 [Patent Document 2] Japanese Patent Application Publication No. 8-145961 Summary of the Invention [Problem to be solved by the invention]

[0005] Let us suppose that an attempt is made to combine the technology of Patent Document 1, which cancels out the lens echo generated within the acoustic lens of the ultrasonic inspection device, with the technology of Patent Document 2, which adjusts the gain according to the signal strength of the reflected wave.

[0006] However, the ultrasonic inspection device according to the combination of Patent Documents 1 and 2 described above is unable to adjust the amplitude of the signal waveform to cancel out the lens echo. As a result, even if an attempt is made to cancel out the lens echo, the lens echo corresponding to the amplitude fluctuation due to the gain adjustment cannot be canceled out and remains, resulting in a problem of impairing the inspection accuracy related to the internal state of the subject.

[0007] The present invention has been made to solve the above-mentioned problems, and aims to provide an ultrasonic inspection device and an ultrasonic inspection method that can perform inspection of the internal state of a subject with high accuracy, even when gain adjustment is performed according to the signal strength of the reflected wave, etc. [Means for solving the problem]

[0008] In order to solve the above problems, an ultrasonic inspection device according to the present invention includes: An ultrasonic inspection device that is configured with an ultrasonic probe having a piezoelectric element and an acoustic lens for transmitting and receiving ultrasonic waves, and that inspects an internal state of a subject using ultrasonic waves, a transmission / reception control unit that drives the piezoelectric element to transmit a predetermined output ultrasonic wave through the acoustic lens, and receives a reflected wave of the transmitted output ultrasonic wave through the acoustic lens and the piezoelectric element; a gain setting unit that sets a gain for amplifying a reflected wave related to the transmission / reception control unit; a reference wave information acquiring unit that acquires, as information on a reference wave related to a lens echo generated within the acoustic lens, the reflected wave amplified using the gain set by the gain setting unit when the output ultrasonic wave is transmitted to a test environment in which the test subject is not present; an interference wave information acquisition unit that acquires the reflected wave amplified using the gain set by the gain setting unit when the output ultrasonic wave is transmitted to an inspection environment in which the subject is present, as information on an interference wave including information on an internal state of the subject; an information processing unit that obtains information about an internal state of the subject based on the interference wave information obtained by the interference wave information obtaining unit and the reference wave information obtained by the reference wave information obtaining unit; The most important feature is that it is configured with the following. [Effects of the Invention]

[0009] According to the present invention, even when gain adjustment is performed according to the signal strength of the reflected wave, it is possible to carry out an inspection of the internal state of the subject with high accuracy. Problems, configurations, and effects other than those described above will be described in detail in the following embodiments. [Brief explanation of the drawings]

[0010] [Figure 1A] 1 is a functional block diagram illustrating the concept of an ultrasonic inspection device according to an embodiment of the present invention. [Figure 1B] FIG. 2 is an explanatory diagram conceptually showing how a lens echo is generated within an acoustic lens provided in an ultrasonic probe. [Figure 1C] 1 is a functional block diagram illustrating a schematic configuration of an ultrasonic inspection device according to an embodiment of the present invention. [Figure 2]FIG. 10 is a flowchart showing the flow of a reference wave database construction process of the ultrasonic inspection device according to the embodiment of the present invention. [Figure 3] FIG. 2 is a flowchart showing the flow of an inspection process of the ultrasonic inspection device according to the embodiment of the present invention. [Figure 4] FIG. 10 is an explanatory diagram showing an example of constructing a reference wave database. [Figure 5] FIG. 2 is an explanatory diagram conceptually showing the function of a noise removal unit provided in the ultrasonic inspection device according to the embodiment of the present invention. [Figure 6A] 10A and 10B are explanatory diagrams showing an interference wave, a reference wave, and a subject reflected wave after subtraction processing when an ultrasonic inspection is performed using a first inspection gain value. [Figure 6B] 10A and 10B are explanatory diagrams showing an interference wave, a reference wave, and a subject reflected wave after subtraction processing when an ultrasonic inspection is performed using a second inspection gain value that is greater than the first inspection gain value. [Figure 7] FIG. 10 is an explanatory diagram showing an example of construction of a probe specification database. [Figure 8] FIG. 10 is an explanatory diagram conceptually showing a modified example in which a first lens echo is left for a reference wave registered in a reference wave database. [Figure 9] FIG. 10 is an explanatory diagram showing a comparison of an interference wave, a subject reflected wave after subtraction processing according to an embodiment, and a subject reflected wave after subtraction processing according to a modified example, when an ultrasonic inspection is performed using a first inspection gain value. DETAILED DESCRIPTION OF THE INVENTION

[0011] An ultrasonic inspection device and an ultrasonic inspection method according to an embodiment of the present invention will be described in detail with reference to the appropriate drawings. In the description of the ultrasonic inspection device according to the embodiment of the present invention, components having common functions are given common reference numerals, and redundant description thereof will be omitted.

[0012] [Concept of ultrasonic inspection device 11A according to an embodiment of the present invention] First, the concept of an ultrasonic inspection device 11A according to an embodiment of the present invention will be described with reference to Figures 1A and 1B. Figure 1A is a functional block diagram showing the concept of the ultrasonic inspection device 11A according to an embodiment of the present invention. Figure 1B is an explanatory diagram conceptually showing how a lens echo is generated within an acoustic lens 15 provided in an ultrasonic probe 17. As shown in FIG. 1A, an ultrasonic inspection device 11A according to an embodiment of the present invention includes an ultrasonic probe 17 having a piezoelectric element 13 for transmitting and receiving ultrasonic waves and an acoustic lens 15, and has a test mode for acquiring information on a reference wave USref related to a lens echo generated within the acoustic lens 15, and an inspection mode for acquiring information on the internal state of a test object 19 such as a semiconductor wafer. More specifically, as shown in FIG. 1A , the ultrasonic inspection device 11A according to the embodiment of the present invention includes a transmission / reception control unit 21 that drives a piezoelectric element 13 to transmit a predetermined output ultrasonic wave through an acoustic lens 15, while receiving a reflected wave of the transmitted output ultrasonic wave through the acoustic lens 15 and the piezoelectric element 13; a gain setting unit 23 that sets a test gain across multiple stages for amplifying the reflected wave related to the transmission / reception control unit 21 in the test mode, while setting an inspection gain value from among the test gain across multiple stages in the inspection mode; a reference wave information acquisition unit 25 that acquires, in the test mode, the reflected waves amplified using each of the test gains across the multiple stages in association with each of the test gains across the multiple stages as information on a reference wave USref related to the lens echo when the output ultrasonic wave is transmitted to a test environment in which no test object 19 is present; The system is configured to include a reference wave database 31 that stores the above information in association with each of the multiple test gains, an interference wave information acquisition unit 27 that acquires, in the inspection mode, the reflected wave amplified using the inspection gain value when the output ultrasound is transmitted to an inspection environment in which the object 19 is present, as information on an interference wave USint including information on the internal state of the object 19, and an information processing unit 29 that acquires information on the internal state of the object 19 based on the information on the interference wave USint acquired by the interference wave information acquisition unit 27 and the information on the reference wave USref stored in the reference wave database 31.

[0013] [Definition of terms] Here, terms used in the description of the embodiments of the present invention will be defined. The drive signal of the piezoelectric element 13 output from the transmission / reception control unit 21 is called a transmission signal, the ultrasonic waves output from the piezoelectric element 13 are called output ultrasonic waves, and the ultrasonic waves returning from the subject 19 are called subject reflected waves. The predetermined output ultrasound wave means an ultrasound wave having a predetermined frequency and signal strength used in ultrasound testing, as shown in FIG. 1B. The reflected wave of the output ultrasound is the ultrasound reflected by the subject 19, etc. when the output ultrasound is transmitted to an inspection environment in which the subject 19 is present, and is a concept that includes information on the reference wave USref related to the lens echo and information on the subject reflected wave that represents the internal state of the subject 19. The information on the reference wave USref means information on a lens echo (noise: see FIG. 1B) that is generated when the output ultrasonic wave transmitted by driving the piezoelectric element 13 is repeatedly internally reflected in the acoustic lens 15. Information on the interference wave USint is a concept that includes both information on the object reflected wave that represents the internal state of the object 19, and information on the reference wave USref related to the lens echo generated within the acoustic lens 15 (see Figure 1B). Note that the reference wave USref and the interference wave USint both have properties that fall into the category of reflected waves, and in the description of the embodiments of the present invention, they will be treated as special cases of reflected waves and given names different from reflected waves.

[0014] The information processing unit 29 reads out information on the reference wave USref corresponding to the inspection gain value from the stored contents of the reference wave database 31, and based on the information on the interference wave USint acquired by the interference wave information acquisition unit 27 and the information on the read reference wave USref, performs a subtraction process to subtract the signal intensity component related to the reference wave USref from the signal intensity component related to the interference wave USint at the same time starting from the time of output of the output ultrasound, thereby obtaining information on the object reflected wave representing the internal state of the object 19.

[0015] According to the ultrasonic inspection device 11A of the embodiment of the present invention, the information processing unit 29 performs subtraction processing to subtract the signal intensity component related to the reference wave USref from the signal intensity component related to the interference wave USint at the same time starting from the output of the output ultrasonic wave, thereby obtaining information on the reflected wave from the object that represents the internal state of the object 19.Therefore, even when gain adjustment is performed according to the signal intensity of the reflected wave, etc., inspection of the internal state of the object 19 can be performed with high accuracy.

[0016] In addition, the ultrasound examination apparatus 11A according to an embodiment of the present invention further includes an image generation unit 35 that generates a cross-sectional image (examination image) of the subject 19 based on information on the internal state of the subject 19 obtained by the information processing unit 29, and a display control unit 37 that displays the examination image of the subject 19 generated by the image generation unit 35 on a display unit 38. With this configuration, even when gain adjustment is performed according to the signal strength of the reflected wave, etc., it is possible to perform an examination of the internal state of the subject 19 with high accuracy, and also to visualize and present the internal state of the subject 19 to the user through the examination image of the subject 19 displayed on the display unit 38.

[0017] In addition, the ultrasonic inspection device 11 according to the embodiment of the present invention further includes a probe specification database 39 (see FIG. 7; details will be described later) that stores specification information for each of multiple types of ultrasonic probes 17, each of which has different specifications, in association with the identification information for the multiple types of ultrasonic probes 17, and a reception unit 33 that receives identification information for the ultrasonic probes 17 to be used for the inspection. In this case, the information processing unit 29 may be configured to read out the specification information for the ultrasonic probe 17 corresponding to the identification information received by the receiving unit 33 from the stored contents of the probe specification database 39, and set the target time region when performing the subtraction process of subtracting the signal intensity component for the reference wave USref from the signal intensity component for the interference wave USint based on the read specification information for the ultrasonic probe 17. The effects of this configuration will be described in detail later.

[0018] Furthermore, in the ultrasonic inspection device 11 according to an embodiment of the present invention, the reception unit 33 receives operation mode instruction information indicating whether the operation mode is the test mode or the inspection mode, as well as the inspection gain value set by the user when the operation mode is the inspection mode, a request to replace the ultrasonic probe 17, and information indicating that the installation environment temperature of the ultrasonic inspection device 11 has fallen outside a specified temperature range. In this case, the reference wave information acquisition unit 25 may be configured to reconstruct the reference wave database 31 when the reception unit 33 receives a request to replace the ultrasonic probe 17 or information that the installation environment temperature of the ultrasonic inspection device 11 has fallen outside a specified temperature range. With this configuration, the reference wave database 31 can be reconstructed in a timely and accurate manner. As a result, even when the gain is adjusted according to the signal strength of the reflected wave, the effect of inspecting the internal state of the subject 19 with high precision can be further improved.

[0019] [Schematic configuration of ultrasonic inspection device 11C according to an embodiment of the present invention] Next, the schematic configuration of an ultrasonic inspection device 11C according to an embodiment of the present invention will be described with reference to Fig. 1C. Fig. 1C is a functional block diagram showing the schematic configuration of the ultrasonic inspection device 11C according to an embodiment of the present invention. The ultrasonic inspection device 11A shown in Fig. 1A and the ultrasonic inspection device 11C shown in Fig. 1C both have common functions. However, they differ in that the ultrasonic inspection device 11A shown in Fig. 1A expresses its functions from a conceptual perspective, whereas the ultrasonic inspection device 11C shown in Fig. 1C expresses its functions from the perspective of a specific configuration. Therefore, the following description will focus on the differences between the two (including supplementary content) instead of describing the ultrasonic inspection device 11C shown in FIG. 1C. In the description of the embodiments of the present invention, when there is no need to distinguish between the ultrasonic inspection device 11A shown in FIG. 1A and the ultrasonic inspection device 11C shown in FIG. 1C, they may be collectively referred to as the "ultrasonic inspection device 11."

[0020] As shown in FIG. 1C, the ultrasonic inspection device 11C is configured with a control device 20 and a probe driving unit 22 that drives the piezoelectric element 13 provided in the ultrasonic probe 17 and also drives the ultrasonic probe 17 itself to scan in three axial directions.

[0021] The piezoelectric element 13 is configured by sandwiching a piezoelectric film (not shown) made of, for example, zinc oxide (ZnO), ceramics, or a fluorine-based copolymer between a pair of electrodes. The piezoelectric element 13 operates by applying a predetermined voltage between the pair of electrodes to vibrate the piezoelectric film, and transmitting a predetermined output ultrasonic wave through this vibration. The piezoelectric element 13 also operates by converting a reflected wave received by the piezoelectric film into a voltage signal generated between the pair of electrodes and outputting it as information on the interference wave USint (see FIG. 1B).

[0022] The acoustic lens 15 serves to focus the predetermined output ultrasonic waves transmitted from the piezoelectric element 13 onto a desired focal position.

[0023] 1A and 1C, the test object 19 is placed in a submerged state at the bottom of a water tank 18 that contains water, which is a propagation medium for ultrasonic waves. The test object 19 is, for example, a semiconductor package including semiconductor wafers with a stacked structure. The ultrasonic probe 17 is immersed in water and is provided so as to directly face the surface of the subject 19 with a predetermined distance between them.

[0024] The control device 20 is configured with a transmission / reception control unit 21, a gain setting unit 23, a noise removal unit 28, a gate setting unit 30, a reference wave database 31, a reception unit 33, an image generation unit 35, a display control unit 37, a display unit 38, a probe specification database 39, and a scanning control unit 41. It should be noted that there are no particular differences between the transmission / reception control unit 21, reference wave database 31, reception unit 33, image generation unit 35, display control unit 37, display unit 38, and probe specification database 39, so redundant explanations will be omitted.

[0025] Here, the problems and gist of the ultrasonic inspection device 11 according to the embodiment of the present invention will be mentioned. Suppose an attempt is made to generate an inspection image relating to the internal state of the object 19 based solely on information about the interference wave USint. In this case, the information about the interference wave USint includes information about the object reflected wave, which represents the internal state of the object 19, as well as information about the reference wave USref (lens echo noise) relating to the lens echo generated within the acoustic lens 15. This means that the lens echo noise appears in the inspection image, making it impossible to generate a highly accurate inspection image. Therefore, in order to generate and use high-precision inspection images, it is important to solve the following problems.

[0026] The first issue is to generate an inspection image by fully revealing the reflected waves from the object, which have a relatively weak signal strength, because even the reflected waves from the object, which have a relatively weak signal strength, may contain defects such as minute voids and peelings that represent the internal state of the object 19, such as a semiconductor wafer.

[0027] The second challenge is to remove lens echo noise from the interference wave USint information before generating the image. This is because, in order to generate and use high-precision inspection images, it is strongly required to precisely acquire information on the object's reflected waves, which form the basis of the inspection image, in a form that does not contain lens echo noise.

[0028] To solve the first problem, the ultrasonic inspection device 11 according to the embodiment of the present invention performs gain adjustment to amplify information on the interference wave USint (information on time-series changes in the interference waveform) output by the piezoelectric element 13 provided in the ultrasonic probe 17 by multiplying it by a predetermined inspection gain value according to its signal strength, in order to pick up all of the object's reflected waves, which have a relatively weak signal strength. However, when gain adjustment is performed to amplify the information on the interference wave USint, not only the information on the object's reflected waves but also the lens echo noise is amplified.

[0029] On the other hand, to solve the second problem, in order to remove lens echo noise from the information about the interference wave USint before generating the inspection image, the signal intensity component related to the reference wave USref is subtracted from the signal intensity component related to the interference wave USint at the same time starting from the output of the output ultrasound. However, if the signal intensity component related to the reference wave (lens echo) USref, which does not take into consideration gain adjustment, as in Patent Document 1, is subtracted from the signal intensity component related to the interference wave USint after the gain adjustment, the lens echo corresponding to the amplitude fluctuation due to the gain adjustment cannot be canceled out and remains, resulting in a loss of inspection accuracy related to the internal state of the subject 19.

[0030] Therefore, in the ultrasonic inspection device 11 according to an embodiment of the present invention, the first and second problems are solved at once, and even when the gain is adjusted according to the signal strength of the reflected wave, the ultrasonic inspection device 11 is provided with a gain setting unit 23 and a noise removal unit 28 in order to perform an inspection of the internal state of the subject 19 with high accuracy.

[0031] That is, in a test mode in which information on the reference wave USref related to the lens echo generated within the acoustic lens 15 is acquired, the gain setting unit 23 sets multiple stages of test gains to amplify the reflected wave related to the transmission / reception control unit 21, while in an inspection mode in which information on the internal state of the specimen 19 such as a semiconductor wafer is acquired, the gain setting unit 23 has the function of setting one of the multiple stages of test gains as an inspection gain value.

[0032] More specifically, in the test mode, the gain setting unit 23 sets multiple stages of test gains and acquires reflected waves, which are reflected when the output ultrasound is transmitted to a test environment where the subject 19 is not present and which are amplified using each of the multiple stages of test gains, as information on the reference wave USref related to the lens echo, in association with each of the multiple stages of test gains. The information on the reference wave USref related to the lens echo acquired in this manner is stored in the reference wave database 31 in association with each of the multiple stages of test gains, and is used as appropriate in the noise removal process (described in detail later) by the noise removal unit 28.

[0033] Meanwhile, in the inspection mode, the gain setting unit 23 sets one of the inspection gain values (gain setting value received by the receiving unit 33) among the multiple stages of test gains, and acquires the reflected wave, which is amplified using the inspection gain value when the output ultrasonic wave is transmitted to the inspection environment in which the object 19 exists, as information on the interference wave USint including information on the internal state of the object 19. The information on the interference wave USint thus acquired is used as appropriate in the noise removal process (described in detail later) by the noise removal unit 28. The gain setting unit 23 also functions as a "reference wave information acquisition unit" and an "interference wave information acquisition unit."

[0034] In the inspection mode, the noise removal unit 28 reads out information on the reference wave USref corresponding to the inspection gain value from the stored contents of the reference wave database 31, and performs a subtraction process to subtract the signal intensity component related to the reference wave USref from the signal intensity component related to the interference wave USint at the same time starting from the output of the output ultrasound, based on information on the interference wave USint including information on the internal state of the subject 19 amplified by the gain setting unit 23 and the information on the read reference wave USref. The same time, starting from the time of output of the output ultrasonic wave, means that the phases of the interference wave USint and the reference wave USref are aligned. The phase alignment between the interference wave USint and the reference wave USref may be appropriately performed by the user visually checking the interference wave USint and the reference wave USref, which share a common time axis, displayed on the display screen of the display unit 38. The signal intensity component refers to the intensity component of the reflected wave (for example, the voltage value generated in the piezoelectric element 13 by the reflected wave) that is generated when the output ultrasound transmitted from the piezoelectric element 13 hits the subject 19 or the like and returns to the piezoelectric element 13.

[0035] In short, the noise removal unit 28 removes information about the reference wave USref related to the lens echo (noise) from information about the interference wave USint, which includes information about the internal state of the subject 19, and outputs information about the internal state of the subject 19 based on the subject reflected wave. Information on the internal state of the subject 19 based on the subject reflected waves output in this way is displayed on the display screen of the display unit . The noise removal unit 28 corresponds to the "information processing unit."

[0036] The gate setting unit 30 detects the depth position relative to the surface of the object 19 based on information on the reflected wave (interference wave USint including information on the internal state of the object 19) related to the transmission / reception control unit 21, and sets the time domain when identifying the detected depth position as a trigger point (see FIG. 8: the depth position correlates with elapsed time) as an S gate, and also sets the time domain defined by an end point delayed by a predetermined time from the trigger point identified by the S gate as an F gate (inspection target region). For details of the setting method of the S gate and the F gate, see, for example, the contents of Japanese Patent No. 7042149.

[0037] The scan control unit 41 shares various information, including the transmission and reception timing of ultrasound and the region to be examined, with the transmission and reception control unit 21, and issues a scan control command to the probe driver 22 based on the various information. That is, the scan control unit 41 operates to control the drive of the mechanical control unit 43 and a triaxial scanner 45 that drives the ultrasonic probe 17 to scan in three axial directions, i.e., the X-axis, Y-axis, and Z-axis, while acquiring current position information related to the ultrasonic probe 17 via the mechanical control unit 43 provided in the probe driver 22.

[0038] [Operation of the ultrasonic inspection device 11 according to the embodiment of the present invention] Next, the operation of the ultrasonic inspection device 11 according to the embodiment of the present invention will be described with reference to FIGS. 2 to 5, 6A, and 6B as appropriate. Fig. 2 is a flowchart showing the flow of the reference wave database construction process of the ultrasonic inspection device 11. Fig. 3 is a flowchart showing the flow of the inspection process of the ultrasonic inspection device 11. Fig. 4 is an explanatory diagram showing an example of construction of the reference wave database 31. Fig. 5 is an explanatory diagram conceptually showing the function of the noise removal unit 28 provided in the ultrasonic inspection device 11.

[0039] [Reference wave database construction process] First, the flow of the process of constructing the reference wave database 31, which is referred to when performing the inspection process related to the ultrasonic inspection device 11, will be described with reference to FIGS. It is assumed that the operating mode of the ultrasonic inspection device 11 is set to a test mode in which information on the reference wave USref related to the lens echo generated within the acoustic lens 15 is acquired for each of multiple test gain stages.

[0040] In step S21, the control device 20 provided in the ultrasonic inspection device 11C sets the count value n of the test gain stage counter to 1 (n=1).

[0041] In steps S22 to S23, the gain setting unit 23 of the control device 20 acquires the nth gain value among the test gains across multiple stages, which corresponds to the count value n of the test gain stage counter CT, and sets the acquired nth gain value.

[0042] In step S24, the transmission / reception control unit 21 associated with the control device 20 drives the piezoelectric element 13 to transmit ultrasonic waves of a predetermined output through the acoustic lens 15.

[0043] In step S25, the gain setting unit 23 of the control device 20 acquires information on the reference wave USref corresponding to the n-th gain value. Note that the information on the reference wave USref corresponding to the n-th gain value refers to waveform information (see FIG. 5) obtained by multiplying the lens echo waveform, which is a reflected wave when the output ultrasound is transmitted to a test environment where the subject 19 is not present, by the n-th gain value and amplifying it.

[0044] In step S26, the gain setting unit 23 of the control device 20 registers in the reference wave database (reference wave DB) 31 a combination of the n-th gain value and information on the reference wave USref corresponding to the n-th gain value.

[0045] In step S27, the gain setting unit 23 associated with the control device 20 determines whether or not all gain values have been processed for the test gains across multiple stages. As a result of the determination in step S27, if it is determined that not all gain values have been processed (No in step S27), the control device 20 advances the flow of the process to the next step S28. On the other hand, if it is determined in step S27 that all gain values have been processed (Yes in step S27), the control device 20 ends the reference wave database construction process.

[0046] In step S28, the control device 20 increments the count value n of the test gain stage counter (n=n+1). Thereafter, the control device 20 returns the process flow to step S22, and repeats the processes of steps S22 to S26 until a determination result is obtained that all gain values have been processed.

[0047] 4, information on the reference wave USref is registered in association with three gain levels (30 / 50 / 80: units of dB) as test gain levels across multiple stages. Here, the information on the reference wave USref registered in the reference wave database 31 may take the form of storing changes in signal intensity data with respect to changes in elapsed time from the time of transmission of the output ultrasonic wave, for example. The number of stages of the test gain is not limited to the above three stages, and may be any appropriate number of stages, such as stages in 1 dB increments between 1 and 80 dB. Also, appropriate values may be adopted for the lower and upper limits of the test gain, taking into consideration various factors such as the material of the object 19, the focal position, etc.

[0048] [Inspection processing] Next, the flow of the inspection process related to the ultrasonic inspection device 11 will be described with reference to FIGS. 3, 5, 6A, and 6B as appropriate. It is assumed that the operation mode of the ultrasonic inspection device 11 is set to an inspection mode for acquiring information on the internal state of an object 19 such as a semiconductor wafer.

[0049] In step S31, the control device 20 provided in the ultrasonic inspection device 11C determines whether or not the reconstruction conditions for the reference wave database (reference wave DB) 31 are satisfied. Here, the reconstruction condition is, for example, when the reception unit 33 receives a request to replace the ultrasonic probe 17 or information that the installation environment temperature of the ultrasonic inspection device 11 has deviated from a predetermined temperature range. When the ultrasonic probe 17 is replaced or the installation environment temperature of the ultrasonic inspection device 11 has deviated from a predetermined temperature range, there is a risk that the inspection results will be impaired if the current reference wave database 31 is used as is. Therefore, in step S31, the control device 20 determines whether or not the conditions for reconstructing the reference wave database 31 are met. As a result of the determination in step S31, if it is determined that the reconstruction condition is satisfied (Yes in step S31), the control device 20 advances the flow of the process to the next step S32. On the other hand, if the result of the determination in step S31 is that the reconstruction condition is not satisfied (No in step S31), the control device 20 causes the process flow to jump to step S33.

[0050] In step S32, the control device 20 causes the display control unit 37 to present information recommending the reconstruction of the reference wave DB. After that, the control device 20 ends the flow of a series of inspection processes. In addition, when a user is presented with information recommending the reconstruction of the reference wave DB, the user will follow a predetermined procedure, such as issuing an operating mode instruction related to the test mode via the reception unit 33, to cause the ultrasonic inspection device 11C to perform the reference wave DB construction process shown in Figure 2.

[0051] In steps S33 to S34, the gain setting unit 23 associated with the control device 20 acquires an inspection gain value set by the user via the reception unit 33 when the operation mode is the inspection mode, and sets the acquired inspection gain value.

[0052] In step S35, the transmission / reception control unit 21 associated with the control device 20 drives the piezoelectric element 13 to transmit ultrasonic waves of a predetermined output through the acoustic lens 15.

[0053] In step S36, the gain setting unit 23 of the control device 20 acquires information on the interference wave USint corresponding to the test gain value. Note that the information on the interference wave USint corresponding to the test gain value refers to waveform information (see FIG. 5) obtained by multiplying the test gain value by the superimposed waveform of the object reflected wave and the reference wave USref related to the lens echo when the output ultrasound is transmitted to the test environment where the object 19 exists and amplifying it.

[0054] In step S37, the gain setting unit 23 of the control device 20 reads and acquires information on the reference wave USref corresponding to the test gain value from the stored contents of the reference wave database 31.

[0055] In step S38, the noise removal unit 28 of the control device 20 performs subtraction processing based on the information on the interference wave USint acquired in step S36 and the information on the reference wave USref acquired in step S37, to subtract the signal intensity component related to the reference wave USref from the signal intensity component related to the interference wave USint at the same time starting from the output of the output ultrasound. This subtraction processing is performed for each unit time on the time axis. In this way, information on the object reflected wave representing the internal state of the object 19 is obtained.

[0056] Here, the operation of the ultrasonic inspection device 11 will be described with reference to FIGS. 6A and 6B. 6A is an explanatory diagram showing an interference wave USint, a reference wave USref, and a subject reflected wave after subtraction processing when an ultrasound examination is performed using a first inspection gain value, and FIG. 6B is an explanatory diagram showing an interference wave USint, a reference wave USref, and a subject reflected wave after subtraction processing when an ultrasound examination is performed using a second inspection gain value that is larger than the first inspection gain value.

[0057] In the case of the first embodiment in which an ultrasound examination was performed using the first examination gain value, the noise removal unit 28 performs subtraction processing to subtract the signal intensity component related to the reference wave USref corresponding to the first examination gain value from the signal intensity component related to the interference wave USint corresponding to the first examination gain value, as shown in Fig. 6A, thereby obtaining information on the object reflected wave according to the first embodiment after the subtraction processing. When the information on the object reflected wave according to the first embodiment is observed, it can be seen that the lens echo noise has been removed.

[0058] On the other hand, in the case of the second embodiment in which an ultrasound examination was performed using a second examination gain value greater than the first examination gain value, the noise removal unit 28 performs subtraction processing to subtract the signal intensity component of the reference wave USref corresponding to the second examination gain value from the signal intensity component of the interference wave USint corresponding to the second examination gain value, as shown in Fig. 6B, thereby obtaining information on the subject reflected wave according to the second embodiment after the subtraction processing. Observation of the information on the subject reflected wave according to the second embodiment reveals that the lens echo noise has been removed and that the signal intensity (wave height) of the subject reflected wave has been amplified compared to the case in which the first examination gain value was used. By amplifying the intensity of the reflected wave signal from the subject in this manner, minute defects hidden inside the subject 19 can be made apparent without being buried in the white noise that inevitably occurs with signal amplification.

[0059] In step S39, the gate setting unit 30 associated with the control device 20 detects the depth position relative to the surface of the subject 19 based on information on the interference wave USint acquired in step S36, and sets the time domain when identifying the detected depth position as a trigger point (see Figure 8) as an S gate, and also sets the time domain delayed by a predetermined time from the trigger point identified by the S gate as an F gate (area to be inspected).

[0060] In step S40, the image generating unit 35 of the control device 20 generates an inspection image relating to the internal state of the subject 19, based on the subject reflected waves relating to the F gate (inspection target region) set in step S39. The inspection image thus generated is amplified by multiplying it by a predetermined inspection gain value, and is generated based on the subject reflected waves from which the influence of the lens echo has been removed, so that it represents the internal state of the subject 19 with high accuracy.

[0061] In step S41, the display control unit 37 associated with the control device 20 displays the examination image generated in step S40 on the display screen of the display unit 38. This allows the internal state of the subject 19 to be visualized and presented to the user through the examination image displayed on the display unit 38.

[0062] [Modification of the noise removal unit 28] Next, modified examples of the noise removal section 28 will be described with reference to FIGS. Fig. 7 is an explanatory diagram showing an example of construction of the probe specification database 39. Fig. 8 is an explanatory diagram conceptually showing a modified example in which the first lens echo is left for the reference wave USref registered in the reference wave database 31.

[0063] In the modified example of the noise removal unit 28, a configuration is adopted in which the first-order lens echo is left out of the lens echoes associated with the reference wave USref registered in the reference wave database 31. Specifically, among the lens echoes associated with the reference wave USref, the first lens echo (see FIG. 8) occurs earliest among multiple lens echoes starting from the time of transmission of the output ultrasonic wave, and its signal strength is also relatively high. The first lens echo may be used by the user to know the approximate lower limit position when positioning the ultrasonic probe 17 in the vertical direction. That is, the user gradually lowers the ultrasonic probe 17 toward the object 19 using the three-axis scanner 45 in order to focus the ultrasonic waves on the interface inside the object 19. At this time, the position of the reflected wave from the surface of the object 19 approaches the position of the first lens echo on the time axis. When the ultrasonic probe 17 is lowered to a position immediately before the collision between the ultrasonic probe 17 and the object 19, the reflected wave from the surface of the object 19 reaches a position adjacent to the first lens echo on the time axis. Therefore, based on the relative positional relationship on the time axis between the reflected wave from the surface of the object 19 and the first lens echo, the user can predict the possibility of a collision between the ultrasonic probe 17 and the object 19. As described above, the position of the first lens echo on the time axis may be used by the user to know the approximate lower limit position when positioning the ultrasonic probe 17 in the vertical direction. Therefore, a configuration is adopted in which the first lens echo is retained from among the lens echoes related to the reference wave USref registered in the reference wave database 31.

[0064] When specifying the time domain related to the first lens echo of the reference wave USref, a probe specification database 39 shown in Fig. 7 is referenced. As shown in Fig. 7, the probe specification database 39 stores specification information (including the first echo gate start point and the first echo gate width) for each of a plurality of types of ultrasonic probes 17 having mutually different specifications, in association with each of the identification information (PR1, PR2, ..., PR9) related to the plurality of types of ultrasonic probes 17. The specification information (the first echo gate start point and the first echo gate width) for each of the plurality of types of ultrasonic probes 17 is set depending on the specifications of the acoustic lens 15 provided in each ultrasonic probe 17. By referring to the probe specification database 39, the noise removal unit 28 according to the modified example identifies the time region of the reference wave USref that is related to the first lens echo, and excludes the identified time region related to the first lens echo from the target time region for the noise removal process. In other words, the target time region when performing the subtraction process of subtracting the signal intensity component related to the reference wave USref from the signal intensity component related to the interference wave USint is set based on the specification information related to the ultrasonic probe 17 so as to exclude the time region related to the first lens echo among the multiple lens echoes.

[0065] FIG. 9 shows a comparison of the interference wave USint corresponding to the first inspection gain value, the object reflected wave according to the first embodiment, and the object reflected wave according to the modified example when an ultrasound inspection is performed using the first inspection gain value. When observing the information on the reflected wave from the subject according to the modified example in comparison with the information on the reflected wave from the subject according to the first embodiment, it is found that the first-order lens echo noise remains.

[0066] According to the ultrasonic inspection device 11 equipped with the noise removal unit 28 of the modified example, the target time region when performing the subtraction process of subtracting the signal intensity component related to the reference wave USref from the signal intensity component related to the interference wave USint is set so as to exclude the time region related to the first lens echo based on the specification information related to the ultrasonic probe 17. This allows the user to know the approximate lower limit position of the ultrasonic probe 17, thereby preventing collision between the ultrasonic probe 17 and the subject 19.

[0067] [Ultrasonic inspection method according to an embodiment of the present invention] Next, an ultrasonic inspection method according to an embodiment of the present invention will be described. The ultrasonic inspection method according to an embodiment of the present invention is based on an ultrasonic inspection method used in an ultrasonic inspection device 11 that includes an ultrasonic probe 17 equipped with a piezoelectric element 13 and an acoustic lens 15 for transmitting and receiving ultrasonic waves, and that has a test mode for acquiring information on a reference wave related to a lens echo generated within the acoustic lens 15, and an inspection mode for acquiring information on the internal state of a test object 19. The ultrasonic inspection method involves driving the piezoelectric element 13 to transmit a predetermined output ultrasonic wave through the acoustic lens 15, while receiving the reflected wave of the transmitted output ultrasonic wave through the acoustic lens 15 and the piezoelectric element 13, thereby inspecting the internal state of a test object 19 using ultrasonic waves. In the ultrasonic inspection method according to an embodiment of the present invention, in the test mode, the following steps are sequentially performed: setting multiple stages of test gains to amplify the reflected waves; and acquiring the reflected waves amplified using each of the multiple stages of test gains when the output ultrasonic waves are transmitted to a test environment where no test object 19 is present, as information on a reference wave USref related to the lens echo, in association with each of the multiple stages of test gains, thereby constructing a reference wave database 31 in which the information on the reference wave USref related to the acquired lens echo is registered in association with each of the multiple stages of test gains. On the other hand, in the inspection mode, the following steps are sequentially performed: a step of setting one of the inspection gain values from multiple stages of test gains; a step of acquiring the reflected wave amplified using the inspection gain value when the output ultrasound is transmitted to the inspection environment in which the test object is present, as information on an interference wave USint including information on the internal state of the test object 19; and an information processing step of obtaining information on the internal state of the test object 19 based on the acquired information on the interference wave USint and information on the reference wave USref stored in the reference wave database 31.

[0068] According to the ultrasonic inspection method of an embodiment of the present invention, in the information processing process, information on the internal state of the object 19 is obtained based on information on the acquired interference wave USint and information on the reference wave USref stored in the reference wave database 31, so that even when gain adjustment is performed according to the signal strength of the reflected wave, etc., inspection of the internal state of the object 19 can be carried out with high accuracy.

[0069] Furthermore, in the ultrasonic inspection method according to an embodiment of the present invention, the information processing step may be configured to read out information on the reference wave USref corresponding to the inspection gain value from the stored contents of the reference wave database 31, and perform a subtraction process to subtract the signal intensity component related to the reference wave USref from the signal intensity component related to the interference wave USint based on the information on the acquired interference wave USint and the information on the read reference wave USref, thereby obtaining information on the internal state of the subject 19.

[0070] With this configuration, the information processing process performs a subtraction process to subtract the signal intensity component related to the reference wave USref from the signal intensity component related to the interference wave USint, thereby obtaining information about the internal state of the subject 19.Therefore, in a more specific embodiment, even when gain adjustment is performed according to the signal intensity of the reflected wave, etc., it is possible to achieve the effect of performing an inspection of the internal state of the subject 19 with high accuracy.

[0071] Furthermore, the ultrasound inspection method according to an embodiment of the present invention may be configured to further include a step of generating an inspection image of the subject 19 based on information about the internal state of the subject 19 obtained in the information processing step, and a step of displaying the generated inspection image of the subject 19 on the display unit 38.

[0072] With this configuration, even when gain adjustment is performed according to the signal strength of the reflected wave, etc., it is possible to perform an examination of the internal state of the subject 19 with high accuracy, and also to visualize and present the internal state of the subject 19 to the user through the examination image of the subject 19 displayed on the display unit 38.

[0073] Furthermore, the ultrasonic inspection method according to the embodiment of the present invention further includes a step of constructing a probe specification database 39 by associating specification information for each of a plurality of types of ultrasonic probes 17 having mutually different specifications with identification information for the plurality of types of ultrasonic probes 17, and a step of receiving identification information for the ultrasonic probes 17 to be used for the inspection. In the information processing step, the specification information for the ultrasonic probe 17 corresponding to the received identification information is read out from the stored contents of the probe specification database 39, and based on the read specification information for the ultrasonic probe 17, a time region related to the first lens echo among the lens echoes related to the reference wave USref is set to be excluded from the target time region when the subtraction process is performed.

[0074] With this configuration, in the information processing step, the target time region when the subtraction process is performed is set so as to exclude the time region related to the first lens echo based on the specification information related to the ultrasonic probe 17, so that the user can know the approximate lower limit position of the ultrasonic probe 17 and prevent collision between the ultrasonic probe 17 and the subject 19.

[0075] Furthermore, the ultrasonic inspection method according to an embodiment of the present invention may be configured to further include a step of receiving a request to replace the ultrasonic probe 17 or information that the installation environment temperature of the ultrasonic inspection device 11 has deviated from a predetermined temperature range, and a step of presenting a request to reconstruct the reference wave database 31 when a request to replace the ultrasonic probe 17 or information that the installation environment temperature of the ultrasonic inspection device 11 has deviated from a predetermined temperature range is received.

[0076] With this configuration, when a request to replace the ultrasonic probe 17 or information is received that the installation environment temperature of the ultrasonic inspection device 11 has fallen outside a specified temperature range, a message is displayed urging the reconstruction of the reference wave database 31, so that the reconstruction of the reference wave database 31 can be carried out in a timely and accurate manner. As a result, even when the gain is adjusted according to the signal strength of the reflected wave, the effect of inspecting the internal state of the subject 19 with high precision can be further improved.

[0077] Furthermore, the ultrasonic inspection method according to an embodiment of the present invention may further include a step of receiving a request to replace the ultrasonic probe 17 or information that the installation environment temperature of the ultrasonic inspection device 11 has deviated from a predetermined temperature range, and the step of constructing the reference wave database 31 may employ a configuration in which the reference wave database 31 is reconstructed when a request to replace the ultrasonic probe 17 or information that the installation environment temperature of the ultrasonic inspection device 11 has deviated from a predetermined temperature range is received.

[0078] With this configuration, in the process of constructing the reference wave database 31, if a request to replace the ultrasonic probe 17 or information is received that the installation environment temperature of the ultrasonic inspection device 11 has fallen outside a specified temperature range, the reference wave database 31 is reconstructed, thereby further enhancing the effectiveness of timely and accurate reconstruction of the reference wave database 31. As a result, even when the gain is adjusted according to the signal strength of the reflected wave, the effect of performing an inspection of the internal state of the subject 19 with high precision can be dramatically improved.

[0079] Other Embodiments The above-described embodiments are merely examples of the present invention, and therefore the technical scope of the present invention should not be construed as being limited by them, as the present invention can be embodied in various forms without departing from the spirit or main characteristics thereof.

[0080] In addition, part of the configuration of the embodiment described here can be replaced with the configuration of another embodiment, and the configuration of one embodiment can be added to the configuration of another embodiment. Furthermore, part of the configuration of each embodiment can be added to, deleted from, or replaced with another configuration.

[0081] Although an example has been described in which the ultrasonic inspection apparatus 11 according to the embodiment of the present invention uses ultrasonic waves to inspect for defects in the internal state of an object 19 such as a semiconductor wafer, the present invention is not limited to this example. The ultrasonic inspection apparatus 11 according to the embodiment of the present invention may also be applied to tray inspection in which the object 19 is an IC tray on which IC circuits are regularly arranged. Furthermore, the reference wave database 31 and the probe specification database 39 may be provided outside the configuration of the ultrasonic inspection apparatus 11, such as on a cloud server, and the ultrasonic inspection apparatus 11 may be configured to access the reference wave database 31 and the probe specification database 39 on the cloud server or the like as needed. [Explanation of symbols]

[0082] 11 Ultrasound inspection equipment 11A Ultrasonic inspection equipment 11C Ultrasound inspection device 13 Piezoelectric element 15 Acoustic Lens 17 Ultrasound probe 19 Subject 20 Control device 21 Transmission and reception control section 22 Probe drive unit 23 Gain setting unit (reference wave information acquisition unit, interference wave information acquisition unit) 25 Reference wave information acquisition section 27 Interference wave information acquisition unit 28 Noise removal unit (information processing unit) 29 Information Processing Department 31 Reference Wave Database (Reference Wave DB) 33 Reception Department 35 Image generation unit 37 Display control unit 38 Display section 39 Probe Specification Database (Probe Specification DB)

Claims

1. An ultrasonic inspection device that is configured with an ultrasonic probe having a piezoelectric element and an acoustic lens for transmitting and receiving ultrasonic waves, and that inspects an internal state of a subject using ultrasonic waves, a transmission / reception control unit that drives the piezoelectric element to transmit a predetermined output ultrasonic wave through the acoustic lens, and receives a reflected wave of the transmitted output ultrasonic wave through the acoustic lens and the piezoelectric element; a gain setting unit that sets a gain for amplifying a reflected wave related to the transmission / reception control unit; a reference wave information acquiring unit that acquires, as information on a reference wave related to a lens echo generated within the acoustic lens, the reflected wave amplified using the gain set by the gain setting unit when the output ultrasonic wave is transmitted to a test environment in which the test subject is not present; an interference wave information acquisition unit that acquires the reflected wave amplified using the gain set by the gain setting unit when the output ultrasonic wave is transmitted to an inspection environment in which the subject is present, as information on an interference wave including information on an internal state of the subject; an information processing unit that obtains information about an internal state of the subject based on the interference wave information obtained by the interference wave information obtaining unit and the reference wave information obtained by the reference wave information obtaining unit; An ultrasonic inspection device comprising:

2. 2. The ultrasonic inspection device according to claim 1, the reference wave information acquisition unit includes a reference wave database that stores information about a reference wave related to the lens echo; The information processing unit performs a process of subtracting a signal intensity component related to the reference wave from a signal intensity component related to the interference wave based on the information on the interference wave acquired by the interference wave information acquisition unit and the information on the reference wave stored in the reference wave database, thereby obtaining information on the internal state of the subject. An ultrasonic inspection device characterized by:

3. An ultrasonic inspection device comprising an ultrasonic probe having a piezoelectric element for transmitting and receiving ultrasonic waves and an acoustic lens, the ultrasonic inspection device having a test mode for acquiring information on a reference wave related to a lens echo generated within the acoustic lens, and an inspection mode for acquiring information on an internal state of a test object, a transmission / reception control unit that drives the piezoelectric element to transmit a predetermined output ultrasonic wave through the acoustic lens, and receives a reflected wave of the transmitted output ultrasonic wave through the acoustic lens and the piezoelectric element; a gain setting unit that sets a test gain across multiple stages for amplifying a reflected wave related to the transmission / reception control unit in the test mode, and sets a test gain value of one of the test gains across multiple stages in the inspection mode; a reference wave information acquiring unit that acquires, in the test mode, the reflected waves amplified using each of the plurality of test gains when the output ultrasonic wave is transmitted to a test environment in which the test subject is not present, as information on reference waves related to the lens echo, in association with each of the plurality of test gains; a reference wave database that stores information about the reference wave related to the lens echo acquired by the reference wave information acquisition unit in association with each of the plurality of test gains; an interference wave information acquisition unit that acquires, in the inspection mode, the reflected wave amplified using the inspection gain value when the output ultrasonic wave is transmitted to an inspection environment in which the object is present, as information on an interference wave including information on an internal state of the object; an information processing unit that obtains information about an internal state of the subject based on the interference wave information obtained by the interference wave information obtaining unit and the reference wave information stored in the reference wave database; An ultrasonic inspection device comprising:

4. 4. The ultrasonic inspection device according to claim 3, The information processing unit reads out information on the reference wave corresponding to the test gain value from the stored contents of the reference wave database, and performs subtraction processing to subtract the signal intensity component related to the reference wave from the signal intensity component related to the interference wave based on the information on the interference wave acquired by the interference wave information acquisition unit and the information on the read reference wave, thereby obtaining information on the internal state of the subject. An ultrasonic inspection device characterized by:

5. 5. The ultrasonic inspection device according to claim 4, an image generating unit that generates an inspection image of the subject based on the information on the internal state of the subject obtained by the information processing unit; a display control unit that displays the examination image of the subject generated by the image generation unit on a display unit. An ultrasonic inspection device characterized by:

6. 6. The ultrasonic inspection device according to claim 4 or 5, a probe specification database that stores specification information for each of a plurality of types of ultrasound probes having mutually different specifications in association with identification information for the plurality of types of ultrasound probes; a reception unit that receives identification information related to the ultrasound probe used in the examination, The information processing unit reads out specification information related to the ultrasonic probe corresponding to the identification information received by the receiving unit from the stored contents of the probe specification database, and sets, based on the read specification information related to the ultrasonic probe, to exclude a time region related to a first lens echo among the lens echoes related to the reference wave from a target time region when performing the subtraction process. An ultrasonic inspection device characterized by:

7. 7. The ultrasonic inspection device according to claim 6, the receiving unit further receives a request to replace the ultrasonic probe or information indicating that the installation environment temperature of the ultrasonic inspection device has deviated from a predetermined temperature range, The reference wave information acquisition unit reconstructs the reference wave database when the reception unit receives a request to replace the ultrasonic probe or information indicating that the installation environment temperature of the ultrasonic inspection device has deviated from a predetermined temperature range. An ultrasonic inspection device characterized by:

8. In an ultrasonic inspection device having an ultrasonic probe equipped with a piezoelectric element and an acoustic lens for transmitting and receiving ultrasonic waves, and having a test mode for acquiring information on a reference wave related to a lens echo generated within the acoustic lens, and an inspection mode for acquiring information on an internal state of a test subject, the ultrasonic inspection method is used when inspecting the internal state of a test subject using ultrasonic waves by driving the piezoelectric element to transmit a predetermined output ultrasonic wave through the acoustic lens, and receiving a reflected wave of the transmitted output ultrasonic wave through the acoustic lens and the piezoelectric element, In the test mode, setting a test gain across multiple stages for amplifying the reflected wave; and a step of acquiring the reflected waves amplified using each of the test gains across the plurality of stages when the output ultrasonic waves are transmitted to a test environment where the test subject is not present, as information on reference waves related to the lens echo, in association with each of the test gains across the plurality of stages, thereby constructing a reference wave database in which information on reference waves related to the acquired lens echo is registered in association with each of the test gains across the plurality of stages, In the inspection mode, setting an inspection gain value among the plurality of test gain stages; acquiring, as information on an interference wave containing information on an internal state of the object, the reflected wave amplified using the inspection gain value when the output ultrasonic wave is transmitted to an inspection environment in which the object is present; an information processing step of obtaining information on the internal state of the subject based on the information on the interference wave obtained and the information on the reference wave stored in the reference wave database. An ultrasonic inspection method characterized by:

9. 9. The ultrasonic inspection method according to claim 8, In the information processing step, information on the reference wave corresponding to the test gain value is read out from the stored contents of the reference wave database, and subtraction processing is performed to subtract the signal intensity component related to the reference wave from the signal intensity component related to the interference wave based on the acquired interference wave information and the read reference wave information, thereby obtaining information on the internal state of the subject. An ultrasonic inspection method characterized by:

10. 10. The ultrasonic inspection method according to claim 9, generating an inspection image of the subject based on the information on the internal state of the subject obtained in the information processing step; and displaying the generated examination image of the subject on a display unit. An ultrasonic inspection method characterized by:

11. 10. The ultrasonic inspection method according to claim 9, constructing a probe specification database by associating specification information for each of a plurality of types of ultrasound probes having mutually different specifications with identification information for the plurality of types of ultrasound probes; and receiving identification information relating to the ultrasound probe used in the examination. In the information processing step, specification information relating to the ultrasonic probe corresponding to the received identification information is read out from the stored contents of the probe specification database, and a time region relating to a first lens echo among the lens echoes relating to the reference wave is excluded from a target time region when the subtraction process is performed based on the specification information relating to the ultrasonic probe that has been read out. An ultrasonic inspection method characterized by:

12. The ultrasonic inspection method according to any one of claims 8 to 10, receiving a request to replace the ultrasonic probe or information indicating that the installation environment temperature of the ultrasonic inspection device is outside a predetermined temperature range; and when a request to replace the ultrasonic probe or information indicating that the installation environment temperature of the ultrasonic inspection device is outside a predetermined temperature range is received, presenting a prompt to reconstruct the reference wave database. An ultrasonic inspection method characterized by:

13. The ultrasonic inspection method according to any one of claims 8 to 10, The method further includes a step of receiving a request to replace the ultrasonic probe or information indicating that the installation environment temperature of the ultrasonic inspection device has deviated from a predetermined temperature range, In the step of constructing the reference wave database, when a request to replace the ultrasonic probe or information indicating that the installation environment temperature of the ultrasonic inspection device has deviated from a predetermined temperature range is received, the reference wave database is reconstructed. An ultrasonic inspection method characterized by:

Images