Ultrasonic examination apparatus and method

Abstract

An ultrasonic inspection method has a registration step of registering a correction parameter inherent to a kind of an inspection object for correcting intensity of a reference signal in association with an inspection object identifier into a hard disk (6); a loading step (step S2) of loading the correction parameter to an arithmetic processing section (5) based on the inspection object identifier; a correction step (step S3) of correcting signal intensity of the reference signal using the loaded correction parameter; and a correlation operation step (step S6) of performing a correlation operation processing of a received signal and the corrected reference signal.

Description

Technical Field

[0001] This invention relates to an ultrasonic inspection apparatus and an ultrasonic inspection method. Background Technology

[0002] As a technique for non-destructively inspecting the internal condition of electronic components such as semiconductor devices, ultrasonic inspection is known. In ultrasonic inspection, ultrasonic waves are irradiated onto the object being inspected, and reflected waves generated from or transmitted through the object are received. The internal condition of the object is then examined based on the received signals. Furthermore, in ultrasonic inspection, correlation processing between the received signals and reference signals is sometimes performed to examine the internal condition of the object.

[0003] As an ultrasonic inspection method that utilizes the aforementioned correlation processing of the received signal and reference signal, Patent Document 1 provides an example. In Patent Document 1, "First, the ultrasonic inspection device uses a standard test piece to obtain a reference waveform from the reflected wave on the surface of the standard test piece" (see "First Embodiment" of Patent Document 1). Furthermore, in Patent Document 1, "The processing unit calculates the correlation coefficient between the received waveform of the reflected wave of interest and the reference waveform, and determines the stripping based on the sign of the correlation coefficient. If the correlation coefficient is negative, the phase is reversed, i.e., it is considered a stripping step" (see First Embodiment).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 6602449 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] Patent Document 1 describes a reference signal used in the correlation processing that is obtained from reflected waves from the surface of a standard test piece. However, ultrasonic waves attenuate inside the object under inspection. Since the attenuation of ultrasonic waves increases with frequency, the frequency intensity distribution of the received signal obtained from reflected waves inside the object under inspection changes relative to the frequency intensity distribution of the incident wave. Specifically, the frequency intensity distribution of the received signal obtained from reflected waves inside the object under inspection shifts towards a lower frequency side relative to the frequency intensity distribution of the incident wave. As a result, the reference signal obtained from reflected waves from the surface of the standard test piece (which has no attenuation inside the object under inspection) and the received signal obtained from reflected waves inside the object under inspection (which has attenuation inside the object under inspection) produce waveform differences. In cases where the waveform difference is extremely large, the correlation between the reference signal and the received signal obtained from reflected waves inside the object under inspection decreases, potentially reducing the reliability of the inspection results based on the correlation processing. Furthermore, the attenuation characteristics of ultrasonic waves depend on the material of the object under inspection, so the degree of waveform difference can vary significantly from one object to another.

[0009] Therefore, the present invention provides an ultrasonic inspection apparatus and ultrasonic inspection method that can obtain inspection results with high accuracy for objects with various ultrasonic attenuation characteristics.

[0010] Methods for solving problems

[0011] To address the aforementioned issues, the ultrasonic inspection apparatus of the present invention comprises: an ultrasonic probe that receives ultrasonic waves irradiated onto an object to be inspected and converts them into an electrical signal; an ultrasonic flaw detector that drives the ultrasonic probe to generate a received signal from the electrical signal; an arithmetic processing unit; and a storage unit. The arithmetic processing unit performs correlation processing on the received signal and a reference signal stored in the storage unit, and inspects the internal state of the object to be inspected based on the result of the correlation processing. The arithmetic processing unit performs the following processing: associating a correction parameter inherent to the type of the object to be inspected, used to correct the intensity of the reference signal, with an object identifier and registering it in the storage unit; loading the correction parameter into the arithmetic processing unit according to the object identifier; and using the loaded correction parameter to correct the signal intensity of the reference signal, and performing correlation processing on the received signal and the corrected reference signal. Other aspects of the present invention will be described in the embodiments described later.

[0012] Invention Effects

[0013] According to the present invention, an ultrasonic inspection method is provided that can obtain inspection results with high accuracy even for objects with various ultrasonic attenuation characteristics. Attached Figure Description

[0014] Figure 1This is a block diagram showing the structure of the ultrasonic inspection device according to the first embodiment.

[0015] Figure 2 This is a diagram illustrating the method for obtaining a reference signal.

[0016] Figure 3 This diagram illustrates a method for obtaining received signals when electronic components are used as the object of inspection.

[0017] Figure 4 It is a diagram showing the waveforms of the reference signal and the received signal obtained from the reflected wave inside the electronic component.

[0018] Figure 5 It is a graph representing the power spectrum of the reference signal and the received signal.

[0019] Figure 6 It is a GUI (Graphical User Interface) that allows users to select the types of objects to be inspected.

[0020] Figure 7 It is a GUI used to receive information about the object to be inspected from the user.

[0021] Figure 8 This is a process flowchart showing the processing sequence of the procedure for inspecting the internal state of the object to be inspected in the first embodiment.

[0022] Figure 9 This diagram illustrates the reflection of ultrasonic waves when they are shone onto an object being inspected.

[0023] Figure 10 This diagram illustrates the method for determining whether there are any abnormalities in the internal state of an object under inspection.

[0024] Figure 11 It is a GUI used to display inspection images on a monitor.

[0025] Figure 12 It is a GUI that displays the correction processing results of the reference signal strength.

[0026] Figure 13 It is a diagram showing the longitudinal structure of an electronic component with multiple interfaces of different height levels.

[0027] Figure 14 This is a flowchart showing the processing sequence of a procedure for obtaining an ultrasonic image representing the internal state of the object to be inspected according to the second embodiment.

[0028] Figure 15 It is a GUI for displaying the ultrasonic images of the second embodiment on a monitor.

[0029] Figure 16 This is a block diagram showing the structure of the ultrasonic inspection device according to the third embodiment.

[0030] Figure 17 This is a diagram illustrating a method for obtaining a reference signal (before correction) according to the third embodiment. Detailed Implementation

[0031] The embodiments for carrying out the present invention will be described in detail with appropriate reference to the accompanying drawings.

[0032] First, an example is given of the difference in waveforms between the reference signal obtained from the reflected wave from the surface of the standard test piece and the received signal obtained from the reflected wave from inside the object under inspection.

[0033] Figure 2 This diagram illustrates the method for obtaining a reference signal. A standard test piece 202 is immersed in water 201. The standard test piece 202 can be made of smooth quartz glass. An ultrasonic testing apparatus (not shown) uses an ultrasonic probe 2 to incident ultrasonic waves onto the standard test piece 202, receives the reflected wave U201 reflected from the surface of the standard test piece 202, and uses the received signal as a reference signal.

[0034] Figure 3 This diagram illustrates a method for obtaining received signals when an electronic component is used as the object of inspection. The electronic component 203 is composed of layers L1 and L2 made of different materials. An ultrasonic inspection apparatus (not shown) uses an ultrasonic probe 2 to incident ultrasonic waves onto the electronic component 203 and receives the reflected wave U202 reflected at the interface between layers L1 and L2.

[0035] Figure 4 It is a diagram showing the waveforms of the reference signal obtained from the reflected wave from the surface of the standard test piece and the received signal obtained from the reflected wave from inside the electronic component. Figure 4 The waveform is the one where the horizontal axis represents time and the vertical axis represents signal strength. The horizontal axis represents time at... Figure 4 It moves to the right from the center, with the amplitude of the vertical axis set at 0 at the center. Figure 4 In the diagram, the upward direction represents positive polarity, and the downward direction represents negative polarity. The same applies to the waveforms described later.

[0036] The reference signal 301 exhibits alternating peaks of different polarities, with the largest amplitude peak appearing in the initial stage and gradually decreasing in amplitude. The received signal 302, obtained from the reflected wave inside the electronic component, also shows alternating peaks of different polarities, but the number and width of the peaks differ from those of the reference signal 301. In other words, differences can be observed in the waveforms of the reference signal 301 and the received signal 302.

[0037] Figure 5This is a graph showing the power spectrum of the reference signal 301 and the received signal 302. Figure 5 The power spectrum is the spectrum with frequency on the horizontal axis and the normalized signal strength normalized to maximum intensity on the vertical axis. The high-frequency components of the power spectrum 402 of the received signal 302 are attenuated significantly, shifting towards the lower frequency side relative to the power spectrum 401 of the reference signal 301. As illustrated above using the accompanying drawings, sometimes a difference in waveform occurs between the reference signal obtained from the reflected wave from the surface of the standard test piece and the received signal obtained from the reflected wave from inside the object under inspection.

[0038] Electronic components, the objects of ultrasonic testing, vary greatly in material, thickness, and layer structure, exhibiting diverse attenuation characteristics. Consequently, the degree of waveform variation can differ significantly from object to object. Therefore, this embodiment provides an ultrasonic testing method capable of obtaining highly accurate inspection results even for objects with various ultrasonic attenuation characteristics.

[0039] First Implementation Method

[0040] Figure 1 This is a block diagram showing the structure of the ultrasonic inspection apparatus 100 according to the first embodiment. The ultrasonic inspection apparatus 100 is configured to include an ultrasonic flaw detector 1, an ultrasonic probe 2, a scanning mechanism 3, a mechanism controller 4, an arithmetic processing unit 5 (microprocessor), a hard disk 6 (storage unit), an oscilloscope 7 (display device), a monitor 8 (display device), an input device 12, etc.

[0041] The ultrasonic flaw detector 1 includes: a pulse generator (not shown) for sending a pulse signal 9 to the ultrasonic probe 2; and a receiver (not shown) for performing amplification, noise removal and other processing on the electrical signal 10 sent from the ultrasonic probe 2 to generate a received signal 11.

[0042] The ultrasonic probe 2 is an ultrasonic probe that generates ultrasonic waves by being driven by an electrical signal, and receives ultrasonic waves and converts them into electrical signals. Furthermore, the ultrasonic probe 2 is held or driven by a scanning mechanism 3, and scans the object being inspected. This scanning mechanism 3 is controlled by a mechanism controller 4.

[0043] As described above, the ultrasonic flaw detector 1 sends a pulse signal 9 to the ultrasonic probe 2, which converts the pulse signal 9 into ultrasonic waves and sends ultrasonic waves U1 to the object 50 being inspected. In the pulse signal 9 of the first embodiment, a pulse signal with a shortened time width is used to improve the resolution in the depth direction. The ultrasonic probe 2 converts the reflected wave U2 generated from the object 50 being inspected into an electrical signal and sends the electrical signal 10 to the ultrasonic flaw detector 1. The ultrasonic flaw detector 1 receives the input of the electrical signal 10 and generates a receiving signal 11, which is then sent to the processing unit 5. In order to scan the appropriate part of the object being inspected using the ultrasonic probe 2, the processing unit 5 sends a control signal to the mechanism controller to achieve control. Automatic control (scanning) of the ultrasonic probe 2 is performed through the system of processing unit 5 → mechanism controller 4 → scanning mechanism 3 → ultrasonic probe 2.

[0044] The data obtained by the arithmetic processing unit 5 (including the received signal 11 and the signals required for the aforementioned automatic control) is stored in the hard disk 6 (storage unit) as needed. In addition, the arithmetic processing unit 5 is connected to the oscilloscope 7 (display device) and the monitor 8 (display device), and can perform A-scope or C-scope display in real time.

[0045] Furthermore, "A-wave display" refers to the display of the received signal 11 when the horizontal axis of the oscilloscope 7 represents time and the vertical axis represents the signal strength of the received signal 11. "C-wave display" refers to the grayscale display of the evaluation value of the received signal 11 at each measurement point when the ultrasonic probe 2 is scanned horizontally and vertically relative to the object being inspected, with the horizontal axis representing the lateral distance of the ultrasonic probe 2's movement and the vertical axis representing the longitudinal distance. Here, the evaluation value refers to the absolute value of the maximum positive or negative value of the received signal 11. The A-wave display is sometimes displayed on the same monitor as the C-wave display via the processing unit 5.

[0046] In addition, the arithmetic processing unit 5 performs processing corresponding to instructions input by the user from the input device 12, such as specifying the evaluation gate (described later) and selecting the peak value of the received signal 11 displayed on the A-wave oscilloscope. The input device 12 may be, for example, a keyboard, a pointing device, etc. The hard disk 6 stores a color palette that defines the colors used according to the waveform of the received signal 11 (especially the size of the peak value) when performing C-wave oscilloscope display. Specifically, the colors are defined using RYB (Red Yellow Blue) values ​​corresponding to the waveform of the received signal 11.

[0047] Furthermore, the evaluation of the received signal 11 used for C-wave display is performed within the range of the evaluation gate. The evaluation gate is used to extract only the component of the reflected wave U2 from the inspection area of ​​the object being inspected from the components of the received signal 11 input from the ultrasonic flaw detector 1 and display it on the C-wave. Therefore, the evaluation gate has the function of opening the gate only for a predetermined time after a predetermined delay time to allow the received signal 11 to pass (gating). The setting of the evaluation gate is performed by the arithmetic processing unit 5, for example, based on the input from the input device 12. Alternatively, the arithmetic processing unit 5 may also parse the received signal 11 and set it automatically. The arithmetic processing unit 5 is equipped with a gate circuit for generating the evaluation gate. However, on the A-wave, it is always necessary to confirm that the maximum positive peak and the maximum negative peak are included within the range of the evaluation gate. This is because if one or both of the maximum positive peak and the maximum negative peak are not included within the range of the evaluation gate, a part that is not the object being inspected may be misidentified as the maximum positive peak or the maximum negative peak, and the evaluation of the object being inspected may not be performed correctly.

[0048] In addition, when obtaining the C-wave from the maximum value of the received signal 11 contained in the evaluation gate, for example, the higher level of the positive and negative peaks in the received signal 11 is selected and reflected in the C-wave.

[0049] The hard disk 6 stores a program (a program for performing an ultrasonic inspection method) for the processing unit 5 to execute the ultrasonic inspection of the first embodiment, a reference signal, a list of types of objects to be inspected, and information on the attenuation rate associated with the type of object to be inspected. The reference signal can be... Figure 2 The method shown is used to obtain the attenuation rate of the ultrasound. The attenuation rate can be calculated by multiplying the attenuation coefficient by the thickness of the object being inspected. The attenuation coefficient of the ultrasound can be determined, for example, using the method described in ASTM (American Standard Testing and Materials) C1332-01, "Standard Test Method for Measurement of Ultrasonic Attenuation Coefficients of Advanced Ceramics by Pulse-Echo Contact Technique".

[0050] The attenuation coefficients of various materials constituting the inspection object are measured, and the attenuation rate can be calculated by multiplying the measured attenuation coefficients by the thickness of the inspection object. The calculated attenuation rate is registered as a correction parameter and saved to the hard disk 6 (registration step). The arithmetic processing unit 5 assigns an identifier to each saved correction parameter and performs a mapping between the identifier of the correction parameter and the identifier of the inspection object. Thus, appropriate correction parameters (attenuation rates) can be selected for inspection objects with various ultrasonic attenuation characteristics.

[0051] Figure 6 This is a GUI (Graphical User Interface) that allows the user to select the type of object to be inspected. GUI13 displays a list of the types of objects to be inspected stored in hard disk 6. The user selects the desired object to be inspected from the list (selection step). The processing unit 5 can save and load the correction parameters corresponding to the identifier of the selected object to the storage area of ​​the processing unit 5 (read-in). As a result, the ease of use of the ultrasonic inspection device 100 is improved. Furthermore, the memory in the storage area can exist either outside or inside the microprocessor, or both.

[0052] Hard disk 6 stores the library information of the objects to be checked that are displayed in the list on GUI 13. By updating the library information of these objects, the objects to be checked displayed in the list on GUI 13 are updated. It is possible to register correction parameters corresponding to the updated object identifiers. Updating the library information of the objects to be checked can be performed by copying the new object library information stored on storage media such as CDs or DVDs to hard disk 6.

[0053] Figure 7 This is a GUI used to receive information about the objects to be inspected from the user. The ultrasonic inspection device 100 can also receive information about the objects to be inspected from the user via the input device 12 and generate new calibration parameters. The ultrasonic inspection device 100 pre-assigns an identifier to the attenuation coefficient of each object to be inspected and associates it with the object identifier.

[0054] The GUI14 receives input from the user regarding the object to be inspected and its thickness. The arithmetic processing unit 5 calculates the attenuation rate based on the attenuation coefficient associated with the object to be inspected and the thickness received from the user. The attenuation rate can be calculated based on the product of the attenuation coefficient and the thickness. The newly calculated attenuation rate is registered as a correction parameter and stored in the hard disk 6.

[0055] Furthermore, the processing unit 5 assigns identifiers to the newly saved calibration parameters and performs mapping between the identifiers of the new calibration parameters and the identifiers of the new inspection objects. As explained above, the user receives information about the inspection object via the input device 12 and generates new calibration parameters, thereby improving the ease of use of the ultrasonic inspection device 100.

[0056] In addition, GUI14 allows users to select multiple materials and accept thickness input for each material. Therefore, even when the object being inspected is composed of multiple different materials, inspection results can be obtained with high accuracy.

[0057] Figure 8 This is a process flowchart showing the processing sequence of the procedure for inspecting the internal state of the object to be inspected according to the first embodiment. The arithmetic processing unit 5 executes the processing program stored on the hard disk 6 to check whether there are any defects inside the object to be inspected.

[0058] In step S1, the reference waveform (reference signal) stored in hard disk 6 is read and input into the program. In step S2, the calibration parameters stored in hard disk 6 are read and input into the program.

[0059] In step S3, a correction process for the reference signal strength is performed. This correction is achieved by multiplying each frequency component by the reference signal using an attenuation rate. Specifically, the corrected reference signal r is obtained using the following equation (1). m (t).

[0060] r n (t)=Real(IFT(e×p(-α×f)×R(f)))…(1)

[0061] Where t is time, α is the correction parameter, f is the frequency, and R(f) is the Fourier transform of the reference signal. Additionally, Real represents the real part of the complex number, and IFT represents the inverse Fourier transform.

[0062] In step S4, the received signal 11 sent from the ultrasonic flaw detector 1 is stored in the storage area of ​​the arithmetic processing unit 5 and input into the program.

[0063] In step S5, the arithmetic processing unit 5 calculates the pixel value for the C-wave display. The pixel value is the grayscale value of the evaluation value of the received signal 11. For example, in a 256-grayscale image, the pixel value takes a value from 0 to 255. The evaluation value is the maximum value of the received signal 11 contained in the evaluation gate. When using the maximum value, the higher of the positive and negative peak values ​​in the received signal 11 can also be selected. The evaluation value is appropriately transformed into a pixel value, for example, in a way that converges to the range of 0 to 255. The pixel value calculated in step S5 is stored in the storage area of ​​the arithmetic processing unit 5.

[0064] In step S6, the arithmetic processing unit 5 calculates the correlation coefficient using the method described later, and determines whether there is any abnormality in the internal state of the object under inspection (abnormality determination). The information on whether there is an abnormality determined in step S6 is stored in the storage area of ​​the arithmetic processing unit 5. In step S7, it is determined whether the processing of all measurement points has ended. If the processing of all measurement points has not ended (step S7, No), the process returns to step S4. If the processing of all measurement points has ended (step S7, Yes), the process proceeds to step S8.

[0065] In step S8, the processing unit 5 generates a two-dimensional image as an inspection image, containing the pixel values ​​of all measurement points and information on whether or not there are any abnormalities. The inspection image generated in step S8 can also display measurement points determined to have abnormalities in color, and display measurement points determined to have no abnormalities in grayscale. In the grayscale display, the pixel values ​​calculated at each measurement point are used. In step S9, the inspection image generated in step S8 is displayed on the monitor 8 (C-oscilloscope display).

[0066] Figure 9 This diagram illustrates the reflection of ultrasonic waves when they are irradiated onto an object under inspection. The object under inspection is an electronic component formed by bonding layers L3 and L4. A peeling occurs as part of the boundary between the bonding surfaces of layers L3 and L4. When ultrasonic waves are incident on the peeling, a reflected wave is generated. The phase of this reflected wave is reversed relative to the phase of the incident wave. This phenomenon is used to determine whether there are any abnormalities such as peeling inside the object under inspection.

[0067] Figure 10 This diagram illustrates the method for determining whether there are any abnormalities in the internal state of the object being inspected in step S6 above. Figure 10 This represents the received signal 15 obtained by irradiating the stripped area with ultrasonic waves. The received signal 15 includes the first half of the time axis segment in layer L3 (refer to...). Figure 9 The reflected wave (surface echo) from the surface of the ) in the latter half of layer L3 and the stripped section (air) (refer to) Figure 9 The signal is the reflected wave (interface echo) from the interface of the received signal 15. To extract the start point of the surface echo from the received signal 15, the processing unit 5 sets a surface echo gate 16 (S-gate). As the surface echo start point 17 (trigger point), the processing unit 5 sets the time during which the signal strength of the received signal 15 exceeds a threshold within the range of the surface echo gate 16. Furthermore, to extract the interface echo, the processing unit 5 sets a time range delayed by a fixed time from the surface echo start point 17 as the evaluation gate 18.

[0068] Next, the arithmetic processing unit 5 performs time axis alignment of the reference signal 19.

[0069] In alignment, the maximum positive and negative signal strength peaks of the received signal 15 within the evaluation gate 18 are used. Figure 10 This indicates the alignment result based on the negative maximum signal strength peak value. The arithmetic processing unit 5 detects the negative maximum signal strength peak value 20 of the received signal 15 within the range of the evaluation gate 18. The reference signal 19 is aligned in the time axis direction in such a way that the maximum signal strength peak value of the reference signal 19 matches the negative maximum signal strength peak value 20 of the received signal 15.

[0070] When alignment is complete, the arithmetic processing unit 5 calculates the correlation coefficient within the time range during which the received signal 15 and the reference signal 19 overlap. At this time, a negative correlation coefficient is obtained. Next, the arithmetic processing unit 5 calculates a positive correlation coefficient based on the positive maximum signal strength peak value, compares the negative correlation coefficient with the positive correlation coefficient, and uses the correlation coefficient with the larger absolute value. If the negative correlation coefficient is large, the interface echo within the evaluation gate 18 range is determined as a stripping candidate. The measurement points determined as stripping candidates are then subjected to threshold processing to ultimately determine whether stripping is required.

[0071] Figure 11 This is a GUI used to display the inspection image on the monitor 8 in step S9 above. GUI 21 displays the areas determined to be normal in grayscale in the inspection image display area 22, and displays the areas determined to be abnormal in color (in the inspection image generation step). Thus, the user can easily identify the abnormal areas.

[0072] GUI21 enables the parameter display area 24 to display the calibration parameters input in step S2 above, as well as information about the inspection object associated with the identifier of the input calibration parameters (calibration parameter display step). This improves the ease of use of the ultrasonic inspection device 100.

[0073] GUI21 receives input from the user regarding whether to perform the calibration process described in step S3 (execute the specified step) via the calibration process activation button 25. Furthermore, if the user does not select an object to be checked, the calibration process activation button 25 is grayed out, thus disabling the calibration process. This allows for easy determination of whether calibration processing can be performed.

[0074] The inspection image displayed in the inspection image display area 22 is output as an EXIF ​​(Exchangeable Image File Format) file (output step) and can be saved on the hard disk 6. The processing unit 5 can also embed the information displayed in the parameter display area 24 into the EXIF ​​file. Specifically, at least one of the loaded correction parameters and the inspection object identifier associated with the loaded correction parameters is written into the output EXIF ​​format image electronic file (writing step). As a result, the ease of use of the ultrasonic inspection device 100 is improved.

[0075] Figure 12 This is a GUI that displays the correction processing results for the reference signal strength. GUI 26 displays the original reference signal 27 before correction processing and the reference signal 28 after correction. By displaying the correction processing results through GUI 26, the reference signal with corrected signal strength can be compared with the A-wave display of the received signal obtained from the object under inspection, displayed on the oscilloscope 7 or monitor 8 (A-wave display step). Thus, the user can confirm that the waveform of the received signal obtained from the object under inspection is no different from the waveform of the reference signal, and can confirm that the correction processing was performed correctly.

[0076] Figure 13 This diagram illustrates the longitudinal structure of an electronic component with multiple interfaces of varying heights. In ultrasonic testing, these interfaces are sometimes examined for abnormalities during a single ultrasonic probe scan. Electronic component 29 has chips 30 and 31 of varying heights, which are sealed by layer L5. If the interface between chip 30 and layer L5 is designated as region 1, or the interface between chip 31 and layer L5 as region 2, the thickness of layer L5 differs in region 1 and region 2, resulting in different ultrasonic attenuation rates. Therefore, different correction parameters (attenuation rates) can be used in region 1 and region 2 for correction processing. For example, the coordinates of the measurement point can be associated with the correction parameters, and the correction parameters can be switched for each measurement point to perform reference signal strength correction processing. That is, in the above registration step, multiple different correction parameters can be associated with the coordinates of the measurement point receiving the signal and registered in the storage unit. This improves the reliability of the inspection results for objects with multiple interfaces of varying heights.

[0077] By using the ultrasonic inspection device of this embodiment described above, it is possible to determine with high precision whether there are any abnormalities inside the object being inspected, even for objects with various ultrasonic attenuation characteristics.

[0078] Second Implementation Method

[0079] In the inspection apparatus of the second embodiment, the cross-correlation signal strength between a reference signal and a received signal obtained from the object under inspection is calculated, and an ultrasonic image representing the internal state of the object under inspection is obtained based on the calculated cross-correlation signal strength. Furthermore, the structure of the ultrasonic inspection apparatus 100 of the second embodiment is the same as that of the ultrasonic inspection apparatus 100 of the first embodiment, therefore, repeated descriptions are omitted (see reference). Figure 1 ).

[0080] In the first embodiment, a pulse signal with a short time width is used for the pulse signal 9. However, in the inspection apparatus of the second embodiment, a modulated signal with a longer time width is used for the pulse signal 9 to improve the signal-to-noise ratio. The modulated signal can be a known modulation signal such as a chirp signal, a frequency offset modulation signal, or a phase offset modulation signal. The reference signal can be... Figure 2 The method shown is used to obtain it. Furthermore, the correction parameters used in the correction processing of the reference signal strength allow the user to... Figure 6 The method selection is shown. Additionally, the correction parameters can also be obtained through... Figure 7 The method shown is used to generate it.

[0081] Figure 14 This is a flowchart illustrating the processing sequence of a procedure for obtaining an ultrasonic image representing the internal state of the object to be inspected according to the second embodiment. This procedure is stored in the hard disk 6 and executed by the arithmetic processing unit 5. The processing contents of steps S1 to S4 are... Figure 8 The process is the same, therefore the explanation is omitted. In step S201, the cross-correlation signal between the reference signal, which underwent correction processing in step S3, and the received signal input in step S4 is calculated. The cross-correlation signal is the cross-correlation function between the reference signal and the received signal. When random noise such as electrical noise is superimposed on the received signal, the processing in step S201 can remove the random noise. This is because the correlation between the reference signal and the random noise is low.

[0082] In step S202, pixel values ​​for C-wave display are calculated based on the cross-correlation signal. The pixel value refers to the grayscale value of the evaluation value of the cross-correlation signal; for example, in a 256-grayscale image, the pixel value ranges from 0 to 255. In calculating the evaluation value, an evaluation gate is used in the same manner as in the first embodiment. For the cross-correlation signal, an evaluation gate is set, and the evaluation value is obtained based on the maximum value of the cross-correlation signal contained within the evaluation gate. Alternatively, the higher of the positive and negative peak values ​​of the cross-correlation signal can be selected and reflected in the evaluation value. The pixel values ​​calculated in step S202 are stored in the storage area of ​​the arithmetic processing unit 5.

[0083] The processing content of step S7 is the same as Figure 8The process is the same, therefore the explanation is omitted. In step S203, a grayscale 2D image is generated as an ultrasonic image based on the pixel values ​​of all measurement points stored in the storage area of ​​the arithmetic processing unit 5. In step S204, the ultrasonic image is displayed on the monitor 8.

[0084] Figure 15 This is the GUI used in step S203 above to display the ultrasonic image on the monitor 8. GUI 32 displays the ultrasonic image in grayscale in the ultrasonic image display area 33. This improves the ease of use of the ultrasonic inspection device 100.

[0085] Conventionally, when aiming to obtain ultrasonic images based on cross-correlation signal strength, the attenuation of ultrasonic waves within the object under inspection leads to a difference in waveform between the reference signal and the received signal obtained using the object, resulting in a decrease in cross-correlation signal strength and thus a lower signal-to-noise ratio. However, in the inspection apparatus of the second embodiment, the reference signal strength is corrected according to the object under inspection, thus enabling the acquisition of ultrasonic images with high signal-to-noise ratios even for objects with various ultrasonic attenuation characteristics.

[0086] Third Implementation Method

[0087] The ultrasonic inspection apparatus of the third embodiment can implement the present invention using the transmission method. The transmission method refers to a method of inspection using ultrasonic waves that have been transmitted through the object to be inspected. On the other hand, a method of inspection using ultrasonic waves reflected from the object to be inspected is called the reflection method. One advantage of the transmission method is that it shortens the propagation distance of ultrasonic waves inside the object to be inspected compared to the reflection method, thereby suppressing ultrasonic wave attenuation and improving the signal-to-noise ratio.

[0088] For example, when inspecting for abnormalities at an interface near the bottom of an object, in the reflection method, ultrasonic waves propagate from the surface of the object to the interface near the bottom, and from the interface near the bottom back to the surface. Therefore, the shortest propagation distance of the ultrasonic waves inside the object is at least twice the thickness of the sample. On the other hand, in the transmission method, ultrasonic waves propagate only from the surface to the bottom of the object, so the shortest propagation distance is equal to the thickness of the sample. Therefore, in the above situation, the transmission method can reduce the propagation distance to approximately half that of the reflection method.

[0089] Figure 16This is a block diagram showing the structure of the ultrasonic inspection apparatus 500 according to the third embodiment. Like the ultrasonic inspection apparatus 100, the ultrasonic inspection apparatus 500 includes an ultrasonic flaw detector 1, an ultrasonic probe 2, a scanning mechanism 3, a mechanism controller 4, a processing unit 5 (microprocessor), a hard disk 6 (storage unit), an oscilloscope 7 (display device), a monitor 8 (display device), an input device 12, etc. (see reference). Figure 1 The ultrasonic inspection apparatus 500 also includes an ultrasonic probe 501 for receiving transmitted waves.

[0090] Ultrasonic probe 501 is an ultrasonic probe that receives ultrasonic waves and converts them into electrical signals. In ultrasonic inspection device 100, ultrasonic probe 2 serves as both a transmitting mechanism for generating ultrasonic waves and a receiving mechanism for receiving ultrasonic waves. However, in ultrasonic inspection device 500, ultrasonic probe 2 functions as a transmitting mechanism, while ultrasonic probe 501 functions as a receiving mechanism.

[0091] The scanning mechanism 3 holds the ultrasonic probe 2 and the ultrasonic probe 501, and makes the ultrasonic probe 2 scan on the object to be inspected and the ultrasonic probe 501 scan under the object to be inspected.

[0092] The ultrasonic flaw detector 1 sends a pulse signal 502 to the ultrasonic probe 2. The ultrasonic probe 2 converts the pulse signal 502 into ultrasonic waves and sends ultrasonic waves U3 to the object under inspection 50. The pulse signal 502 is a modulated signal with a long time width (see the second embodiment). The ultrasonic probe 501 converts the transmitted wave U4 that has passed through the object under inspection 50 into an electrical signal and sends the electrical signal 503 to the ultrasonic flaw detector 1. The ultrasonic flaw detector 1 receives the input of the electrical signal 503, generates a received signal 504, and sends it to the processing unit 5.

[0093] The processing unit 5 stores the received signal 504 in the hard disk 6 (storage unit) as needed. Furthermore, the processing unit 5 is connected to the oscilloscope 7 (display device) and the monitor 8 (display device), enabling real-time A-wave or C-wave display.

[0094] Similar to the ultrasonic inspection apparatus of the second embodiment, the ultrasonic inspection apparatus 500 calculates a cross-correlation signal between a reference signal and a received signal obtained from the object under inspection, and obtains an ultrasonic image representing the internal state of the object under inspection based on the calculated cross-correlation signal strength. In this case, the received signal is obtained from transmitted waves.

[0095] Figure 17This diagram illustrates a method for obtaining a reference signal (before calibration) according to the third embodiment. Ultrasonic probe 2 and ultrasonic probe 501 are immersed in water 201. The ultrasonic inspection apparatus 500 uses ultrasonic probe 2 to transmit ultrasonic waves U203. The ultrasonic waves U203 propagate in the water 201 and are received by ultrasonic probe 501. The received signal is used as the reference signal (before calibration).

[0096] The hard disk 6 stores a program for acquiring ultrasonic images representing the internal state of the object being inspected, which is executed by the arithmetic processing unit 5. The processing performed is the same as in the second embodiment, therefore, a description is omitted (see reference). Figure 14 The correction parameters used for the correction processing of the reference signal strength can be obtained by the user. Figure 6 The method selection is shown. Additionally, the correction parameters can also be obtained through... Figure 7 The method shown is used to generate it.

[0097] With the above structure, the present invention can be implemented using the transmission method. As described in the second embodiment, when it is desired to obtain an ultrasonic image based on the cross-correlation signal strength, due to the attenuation of ultrasonic waves inside the object under inspection, there is a problem that the waveforms of the reference signal and the received signal obtained using the object under inspection differ, resulting in a reduced signal-to-noise ratio. This problem also occurs in the transmission method. However, in the ultrasonic inspection apparatus 500 of the third embodiment, the reference signal strength is corrected according to the object under inspection, so even for objects under inspection with various ultrasonic attenuation characteristics, an ultrasonic image with a high signal-to-noise ratio can be obtained using the transmission method.

[0098] The ultrasonic inspection method of this embodiment described above has the following characteristics.

[0099] The ultrasonic inspection method of this embodiment is as follows: ultrasonic waves are irradiated onto the object to be inspected, a received signal is obtained from the object, correlation processing of the received signal and a reference signal (e.g., reference signal 19) is performed in the processing unit, and the internal state of the object is inspected based on the result of the correlation processing. The ultrasonic inspection method includes: a registration step, which associates the correction parameters inherent to the type of object used to correct the intensity of the reference signal with an object identifier and registers them in the storage unit; a loading step (… Figure 8 Step S2), the correction parameters are loaded into the arithmetic processing unit based on the object identifier being checked; correction steps (e.g. Figure 8 Step S3), using the applied correction parameters to correct the signal strength of the reference signal; and related computational steps (e.g., Figure 8In step S6), correlation processing of the received signal and the corrected reference signal is performed. According to this embodiment, the ultrasonic inspection method can provide an ultrasonic inspection method that can obtain inspection results with high accuracy even for objects with various ultrasonic attenuation characteristics. Furthermore, the correlation processing can also be the method described above. Figure 8 The processing of the correlation coefficient between the received signal and the reference signal, other than the processing described in step S6 and above.

[0100] The ultrasonic examination method of this embodiment can be applied to both reflection (see the first embodiment and the second embodiment) and transmission (see the third embodiment).

[0101] The ultrasonic inspection method has a selection step in which a display device (e.g., monitor 8) displays a list of the types of inspection objects registered in the registration step, and the user selects the type of inspection object from the list. In the loading step, correction parameters are loaded into the arithmetic processing unit based on the type of inspection object selected by the user in the selection step.

[0102] In the registration step, based on the information about the object to be inspected received from the user via the input device, new correction parameters can be generated, and the newly generated parameters can be associated with the object identifier and registered in the storage unit (see reference). Figure 7 (Explanation).

[0103] In the above registration steps, the correction parameter depends on the attenuation rate of the ultrasonic frequency (refer to...). Figure 6 , Figure 7 (Explanation).

[0104] The ultrasonic inspection method includes a calibration parameter display step that displays the object identification symbol on the display device and the calibration parameters loaded in the above loading step (see reference). Figure 11 (Explanation).

[0105] The ultrasonic testing method includes a reference signal A-wave display step that enables the display device to display the calibrated reference signal using an A-wave method (see reference). Figure 12 (Explanation).

[0106] The ultrasound examination method has the option to accept a specified step from the user regarding whether to perform the above-mentioned calibration steps (see reference). Figure 11 (Explanation).

[0107] The ultrasound examination method includes: an examination image generation step, generating an examination image based on relevant computational processing results; an output step, outputting the examination image in EXIF ​​(Exchangeable Image Format) format; and a writing step, writing at least one of the loaded correction parameters and an examination object identifier associated with the loaded correction parameters into the output EXIF ​​format image electronic file.

[0108] Ultrasonic inspection methods include: pixel value calculation steps (e.g.) Figure 8 Step S5), calculate the pixel values ​​of the grayscale image based on the intensity of the received signal; and check the image generation step ( Figure 8 In step S8), after performing the relevant calculation steps, an inspection image containing pixel values ​​and information about abnormal regions is generated.

[0109] The ultrasound examination method includes the step of calculating the cross-correlation signal. Figure 14 Step S201), calculating the cross-correlation function signal between the received signal and the corrected reference signal to replace the above correlation calculation step; and the ultrasonic image generation step ( Figure 14 Step S203) generates an ultrasonic image based on the intensity of the cross-correlation function signal.

[0110] In the registration step, multiple different correction parameters are associated with the coordinates of the measurement points of the received signal and registered in the storage unit (see reference). Figure 13 (Explanation).

[0111] Furthermore, the present invention is not limited to the embodiments described above, and includes various modifications. For example, the embodiments described above are those that have been explained in detail for the purpose of easily understanding the present invention, and are not limited to having all the structures described. In addition, it is possible to replace a part of the structure of a certain embodiment with the structure of another embodiment, and it is also possible to add the structure of another embodiment to the structure of a certain embodiment. Furthermore, for a part of the structure of each embodiment, it is possible to add, delete, or replace other structures.

[0112] Furthermore, the aforementioned structures, functions, processing units, and processing modules can also be implemented in hardware, for example, by designing some or all of them using integrated circuits. Alternatively, the aforementioned structures and functions can be implemented in software by a processor interpreting and executing programs that implement each function. The programs, tables, files, and other information implementing each function can be stored in storage devices such as memory, hard disks, SSDs (Solid State Drives), or storage media such as IC cards, SD cards, and DVDs.

[0113] Furthermore, while control lines and information lines are indicated in the specifications, they may not necessarily represent all control lines and information lines on the product itself. In fact, it can be assumed that almost all of the structural elements are interconnected.

[0114] Symbol Explanation

[0115] 1. Ultrasonic flaw detector

[0116] 2. Ultrasonic probe

[0117] 3. Scanning Mechanism Department

[0118] 4. Mechanism Controller

[0119] 5. Computation and Processing Unit

[0120] 6. Hard Disk Drive (Storage Section)

[0121] 7. Oscilloscope (A. Oscilloscope display, display device)

[0122] 8. Monitor (C-type oscilloscope display, display device)

[0123] 9. Pulse signal

[0124] 10 Electrical signals

[0125] 11 Receiving signals

[0126] 12 Input Devices

[0127] 13, 14, 21, 26, 32 GUI

[0128] 15 Receiving Signals

[0129] 16 Surface Echo Gate

[0130] 17. Surface echo start point

[0131] 18. Evaluate the gate

[0132] 19 Reference Signal

[0133] 20 negative maximum signal strength peak

[0134] 22. Check the image display area.

[0135] 23. Areas identified as abnormal

[0136] 24 Parameter Display Area

[0137] 25. Correction Processing Activation Button

[0138] 27. Reference signal (before calibration)

[0139] 28. Reference signal (after calibration)

[0140] 29 Electronic components

[0141] Chips 30 and 31

[0142] 33 Ultrasonic image display area

[0143] 50. Objects to be inspected

[0144] 100 and 500 ultrasonic inspection devices

[0145] 201 Water

[0146] 202 Standard Test Piece

[0147] 203 Electronic Components

[0148] 301 Reference signal (reflected wave from the surface of the standard test piece)

[0149] 302 Received signal (reflected wave from inside electronic components)

[0150] 401 Power Spectrum (Reference Signal)

[0151] 402 Power Spectrum (Received Signal)

[0152] 501 Ultrasonic Probe

[0153] 502 pulse signal

[0154] 503 Electrical Signal

[0155] 504 Received Signal

[0156] Layers L1, L2, L3, L4, and L5.

Claims

1. An ultrasonic inspection apparatus comprising: an ultrasonic probe that receives an ultrasonic wave irradiated to an inspection object and converts it into an electric signal; an ultrasonic flaw detector that drives the ultrasonic probe to generate a reception signal from the electric signal; an arithmetic processing section that performs a correlation operation process of the reception signal and a reference signal stored in a storage section, and inspects an internal state of the inspection object based on a result of the correlation operation process; and the storage section, characterized in that the arithmetic processing section performs the following processes: registers a correction parameter inherent to a kind of inspection object for correcting an intensity of the reference signal in association with an inspection object identifier into the storage section; registers different correction parameters in association with measurement point coordinates of a reception signal into the storage section at the time of registering the correction parameter into the storage section, loads the correction parameter into the arithmetic processing section according to the inspection object identifier; and corrects a signal intensity of the reference signal using the loaded correction parameter, and performs a correlation operation process of the reception signal and the corrected reference signal.

2. The ultrasonic inspection apparatus according to claim 1, characterized in that the arithmetic processing section performs the following processes: list displays the registered kinds of inspection object in a display apparatus, and causes a user to select a kind of inspection object from the list displayed kinds of inspection object; and loads the correction parameter into the arithmetic processing section according to the kind of inspection object selected by the user.

3. The ultrasonic inspection apparatus according to claim 1, characterized in that the arithmetic processing section newly generates a correction parameter based on a result of accepting information of an inspection object from a user through an input apparatus, and registers the newly generated correction parameter in association with an inspection object identifier into the storage section.

4. The ultrasonic inspection apparatus according to any one of claims 1 to 3, characterized in that the correction parameter is an attenuation rate depending on a frequency of an ultrasonic wave.

5. The ultrasonic inspection apparatus according to any one of claims 1 to 3, characterized in that the arithmetic processing section causes a display apparatus to display the inspection object identifier and the loaded correction parameter.

6. The ultrasonic inspection apparatus according to any one of claims 1 to 3, characterized in that the arithmetic processing section causes a display apparatus to perform an A-scope display of the corrected reference signal.

7. The ultrasonic inspection apparatus according to any one of claims 1 to 3, characterized in that the arithmetic processing section accepts a designation from a user as to whether to correct a signal intensity of the reference signal using the loaded correction parameter.

8. The ultrasonic inspection apparatus according to any one of claims 1 to 3, characterized in that the arithmetic processing section performs the following processes: generates an inspection image according to a result of the correlation operation process; outputs the inspection image in an EXIF format, the EXIF being an Exchangeable Image File Format; and ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ A correction parameter is written to the output EXIF format image electronic file, and the correction parameter is written to at least one of the loaded correction parameter and the inspection object identifier associated with the loaded correction parameter.

9. The ultrasonic inspection apparatus according to any one of claims 1 to 3, characterized in that The operation processing section performs the following processing: The pixel value of the gray scale image is calculated from the intensity of the received signal; and An inspection image containing the calculated pixel value and information of the abnormal region is generated.

10. An ultrasonic inspection apparatus comprising: an ultrasonic probe that receives an ultrasonic wave irradiated to an inspection object and converts it into an electric signal; an ultrasonic flaw detector that drives the ultrasonic probe and generates a received signal from the electric signal; an operation processing section that calculates a cross-correlation function signal of the received signal and a reference signal stored in a storage section, and inspects an internal state of the inspection object based on the cross-correlation function signal; and the storage section, characterized in that The operation processing section performs the following processing: A correction parameter inherent to a kind of inspection object for correcting the intensity of the reference signal is registered in the storage section in association with an inspection object identifier; When registering a correction parameter in the storage section, a plurality of correction parameters different from each other are registered in the storage section in association with measurement point coordinates of a received signal; A correction parameter is loaded into the operation processing section according to the inspection object identifier, and the signal intensity of the reference signal is corrected using the loaded correction parameter; A cross-correlation function signal of the received signal and the corrected reference signal is calculated, and an ultrasonic image is generated from the intensity of the cross-correlation function signal.

11. An ultrasonic examination method of irradiating an examination object with an ultrasonic wave, acquiring a reception signal from the examination object, performing a correlation operation process of the reception signal and a reference signal by an operation processing section, and examining an internal state of the examination object based on a result of the correlation operation process, characterized by, The ultrasonic inspection method has the following steps: A registration step of registering a correction parameter inherent to a kind of inspection object for correcting the intensity of the reference signal in the storage section in association with an inspection object identifier; A loading step of loading the correction parameter into the operation processing section according to the inspection object identifier; A correction step of correcting the signal intensity of the reference signal using the loaded correction parameter; and A correlation operation step of performing a correlation operation process of the received signal and the corrected reference signal, In the registration step, a plurality of correction parameters different from each other are registered in the storage section in association with measurement point coordinates of a received signal.

12. The ultrasonic inspection method according to claim 11, characterized in that The ultrasonic inspection method has a selection step of causing a display device to list kinds of inspection objects registered in the registration step, and causing a user to select a kind of inspection object from the kinds of inspection objects listed by the list display, In the loading step, the correction parameter is loaded into the operation processing section based on the kind of inspection object selected by the user in the selection step.

13. The ultrasonic inspection method according to claim 11, characterized in that In the registration step, a correction parameter is newly generated based on a result of accepting information of the inspection object from the user through the input device, and the newly generated parameter is registered in the storage section in association with the inspection object identifier.

14. The ultrasonic inspection method according to any one of claims 11 to 13, characterized in that, In the registration step, the correction parameter is an attenuation rate that depends on a frequency of the ultrasonic wave.

15. The ultrasonic inspection method according to any one of claims 11 to 13, characterized in that, The ultrasonic inspection method has a correction parameter display step of causing a display device to display the inspection object identifier and the correction parameter loaded in the loading step.

16. The ultrasonic inspection method according to any one of claims 11 to 13, characterized in that, The ultrasonic inspection method has a reference signal A-scope display step of causing a display device to A-scope the corrected reference signal.

17. The ultrasonic inspection method according to any one of claims 11 to 13, characterized in that, The ultrasonic inspection method has: a pixel value calculation step of calculating a pixel value of a gray scale image from an intensity of the reception signal; and an inspection image generation step of generating an inspection image containing information of the pixel value and an abnormal region after the correlation operation step is executed.

18. An ultrasonic inspection method of irradiating an ultrasonic wave to an inspection object, acquiring a reception signal from the inspection object, calculating a cross-correlation function signal of the reception signal and a reference signal by an arithmetic processing section, and checking an internal state of the inspection object based on the cross-correlation function signal, characterized by comprising: a registration step of registering a correction parameter inherent to a kind of the inspection object for correcting an intensity of the reference signal in association with an inspection object identifier in a storage section; a loading step of loading the correction parameter to the arithmetic processing section according to the inspection object identifier; a correction step of correcting a signal intensity of the reference signal using the loaded correction parameter; a step of calculating a cross-correlation function signal of the reception signal and the corrected reference signal; and an ultrasonic image generation step of generating an ultrasonic image based on an intensity of the cross-correlation function signal, wherein in the registration step, a plurality of different correction parameters are registered in the storage section in association with measurement point coordinates of a reception signal. ​

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