TW202141036A - Ultrasonic inspection device and ultrasonic inspection method - Google Patents

Abstract

An ultrasonic inspection method has: a registration step in which a correction parameter unique to the type of an inspection subject is registered in a hard disk (6) in association with an inspection subject identifier, the correction parameter being for correcting the intensity of a reference signal; a loading step (step S2) in which the correction parameter is loaded into a computation processing unit (5) on the basis of the inspection subject identifier; a correction step (step S3) in which the loaded correction parameter is used to correct the signal intensity of the reference signal; and a correlation computation step (step S6) in which a process for computing the correlation between a reception signal and the corrected reference signal is executed.

Description

Ultrasonic inspection device and ultrasonic inspection method

The invention relates to an ultrasonic inspection device and an ultrasonic inspection method.

As a technique for non-destructively inspecting the internal state of electronic components such as semiconductor elements, inspection by ultrasonic waves is known. In ultrasonic inspection, ultrasonic waves are irradiated to an inspection target, and reflected waves generated from the inspection target or penetrating waves penetrating the inspection target are received, and the internal state of the inspection target is inspected based on the received signal. In addition, in the ultrasonic inspection, the correlation calculation process between the received signal and the reference signal is sometimes performed to inspect the internal state of the inspection object.

As an ultrasonic inspection method using the aforementioned correlation calculation processing of the received signal and the reference signal, there is, for example, Patent Document 1. Patent Document 1 describes "First, the ultrasonic inspection apparatus uses a standard test piece to obtain a reference waveform from the reflected wave on the surface of the standard test piece." (refer to "First Embodiment" of Patent Document 1). In addition, Patent Document 1 states that "the calculation processing unit calculates the correlation coefficient between the received waveform of the reflected wave of interest and the reference waveform, and performs peeling determination based on the sign of the correlation coefficient. If the correlation coefficient is negative, the phase is expected to be reversed. Turn, that is, the peeling part." (Refer to the first embodiment). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 6602449

[The problem to be solved by the invention]

Patent Document 1 describes that the reference signal used in the related calculation process is obtained from the reflected wave on the surface of the standard test piece. However, ultrasonic attenuation occurs inside the inspection object. The attenuation of ultrasonic waves increases as the frequency increases. Therefore, the frequency intensity distribution of the received signal obtained from the reflected wave inside the inspection object changes with respect to the frequency intensity distribution of the incident wave. Specifically, the frequency intensity distribution of the received signal obtained from the reflected wave inside the inspection object is shifted to the low-frequency side relative to the frequency intensity distribution of the incident wave. As a result, the reference signal obtained from the reflected wave on the surface of the standard test piece (without attenuation inside the inspection object), and the received signal obtained from the reflected wave inside the inspection object (with attenuation inside the inspection object) ) Differences in waveforms will occur. When the waveform difference is extremely large, the correlation between the reference signal and the received signal obtained from the reflected wave inside the inspection object will be reduced, and the reliability of the inspection result based on the relevant calculation processing may be reduced. In addition, the attenuation characteristics of ultrasonic waves depend on the material of the inspection object, so the degree of difference in waveforms may vary greatly for each inspection object.

In view of this, the present invention provides an ultrasonic inspection device and an ultrasonic inspection method that can accurately obtain inspection results even for inspection objects having various ultrasonic attenuation characteristics. [Technical means to solve the problem]

In order to solve the aforementioned problems to be solved, the ultrasonic inspection device of the present invention includes: an ultrasonic probe that receives ultrasonic waves irradiated on the inspection object and converts it into an electronic signal; and drives the ultrasonic probe to generate a received signal from the electronic signal. Sonic flaw detector; and calculation processing unit; and memory unit; calculation processing unit, which performs correlation calculation processing between the received signal and the reference signal stored in the memory unit, and checks the internal state of the inspection object based on the results of the correlation calculation processing The inspection device is characterized in that the arithmetic processing unit associates a correction parameter specific to the type of inspection object used to correct the strength of the reference signal with the inspection object identification code and registers it in the memory unit, based on the inspection object identification code Load the correction parameters into the calculation processing section, use the loaded correction parameters to correct the signal strength of the reference signal, and perform the relevant calculation processing between the received signal and the corrected reference signal. Other aspects of the present invention will be described in the following embodiments. [Effects of the invention]

According to the present invention, it is possible to provide an ultrasonic inspection method capable of accurately obtaining inspection results even for inspection objects having various ultrasonic attenuation characteristics.

Regarding the embodiments used to implement the present invention, it is appropriate to refer to the drawings and describe them in detail. First, an example will be explained in which the reference signal obtained from the reflected wave on the surface of the standard test piece and the received signal obtained from the reflected wave inside the inspection object have different waveforms.

Fig. 2 is a diagram illustrating a method of obtaining a reference signal. The standard test piece 202 is immersed in water 201. For the standard test piece 202, smooth quartz glass can be used. An ultrasonic inspection device not shown in the figure uses the ultrasonic probe 2 to incident ultrasonic waves on the standard test piece 202, receives the reflected wave U201 reflected on the surface of the standard test piece 202, and sets the received signal as a reference signal.

FIG. 3 is a diagram illustrating a method of obtaining a received signal in the case of using an electronic component as an inspection object. The electronic component 203 is composed of a layer L1 and a layer L2 of different materials. An ultrasonic inspection device not shown in the figure uses the ultrasonic probe 2 to inject an ultrasonic wave into the electronic component 203 and receives the reflected wave U202 reflected at the interface between the layer L1 and the layer L2.

4 is a diagram illustrating the waveforms of the reference signal obtained from the reflected wave on the surface of the standard test piece and the received signal obtained from the reflected wave inside the electronic component. The waveform in Figure 4 is the waveform when time is taken as the horizontal axis and signal intensity is taken as the vertical axis. The time taken on the horizontal axis travels to the right in Fig. 4, and the amplitude taken on the vertical axis is set to 0 at the center. The upward direction in Fig. 4 indicates the positive polarity, and the downward direction indicates the negative polarity. For these directions, the same applies to the waveforms described later.

With reference to the signal 301, peaks with different polarities appear alternately. Among these peaks, the peak with the largest amplitude appears in the initial stage, and such a waveform gradually decreases. The received signal 302 obtained from the reflected wave inside the electronic component also has peaks with different polarities alternately, but the number of peaks or peak amplitudes are different from the reference signal 301. In other words, the difference between the waveforms of the reference signal 301 and the received signal 302 can be seen.

FIG. 5 is a diagram illustrating the power spectrum of the reference signal 301 and the received signal 302. The power spectrum in Fig. 5 is the spectrum when the frequency is taken as the horizontal axis and the normalized signal intensity after the maximum intensity is taken as the vertical axis. The power spectrum 402 of the received signal 302 has a large attenuation of high-frequency components, and is shifted toward the low-frequency side relative to the power spectrum 401 of the reference signal 301. As explained in the above figures, there may be a difference in waveform between the reference signal obtained from the reflected wave on the surface of the standard test piece and the received signal obtained from the reflected wave inside the inspection object.

The inspection object of ultrasonic inspection, namely, electronic parts, has rich variability in material, thickness, and layer structure, and has various attenuation characteristics. Therefore, the degree of difference of the aforementioned waveforms may also be greatly different for each inspection object. In view of this, the present embodiment provides an ultrasonic inspection method that can accurately obtain inspection results even for inspection objects having various ultrasonic attenuation characteristics.

"First Embodiment" Fig. 1 is a block diagram showing the configuration of an ultrasonic inspection apparatus 100 according to the first embodiment. The ultrasonic inspection device 100 includes an ultrasonic flaw detector 1, an ultrasonic probe 2, a scanning mechanism section 3, a mechanism section controller 4, a calculation processing section 5 (microprocessor), a hard disk 6 (memory section), and an oscilloscope 7 ( A display device), a monitor 8 (display device), an input device 12, and the like are constituted.

The ultrasonic flaw detector 1 is equipped with a pulse generator (not shown) for sending a pulse signal 9 to the ultrasonic probe 2, and for performing amplification and noise on the electronic signal 10 sent from the ultrasonic probe 2 A receiver (not shown) that generates the received signal 11 after removing the processing.

The ultrasonic probe 2 is an ultrasonic probe that is driven by an electronic signal to generate an ultrasonic wave, and receives the ultrasonic wave and transforms it into an electronic signal. In addition, the ultrasonic probe 2 is held or driven by the scanning mechanism 3 and scans the inspection target. The scanning mechanism 3 is controlled by the mechanism controller 4.

The ultrasonic flaw detector 1 transmits a pulse signal 9 to the ultrasonic probe 2 as described above, and the ultrasonic probe 2 converts the pulse signal 9 into an ultrasonic wave and sends an ultrasonic wave U1 to the inspection target 50. In the pulse wave signal 9 of the first embodiment, in order to improve the resolution in the depth direction, a pulse signal whose time width is shortened is used. The ultrasonic probe 2 converts the reflected wave U2 generated from the inspection target 50 into an electronic signal, and sends the electronic signal 10 to the ultrasonic flaw detector 1. The ultrasonic flaw detector 1 receives the input of the electronic signal 10 to generate a reception signal 11, and sends the reception signal 11 to the arithmetic processing unit 5. The arithmetic processing unit 5 sends a control signal to the mechanism controller in order to use the ultrasonic probe 2 to scan an appropriate part of the object to be inspected, so as to realize control and adjustment. The automatic control (scanning) of the ultrasonic probe 2 is achieved through the system of calculation processing 5→mechanical part controller 4→scanning mechanism 3→ultrasonic probe 2.

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

In addition, the so-called "A oscilloscope display" is the display of the received signal 11 when the time is taken as the horizontal axis of the oscilloscope 7 and the signal strength of the received signal 11 is taken as the vertical axis. In addition, the so-called "C oscillometric display" means that the ultrasonic probe 2 is scanned vertically and horizontally on the inspection object, and the horizontal distance of the ultrasonic probe 2 movement is taken as the horizontal axis of the display screen, and the vertical distance is taken as the vertical axis. The level of the evaluation value of the received signal 11 at each measurement point is displayed. The so-called evaluation value here is the absolute value of the positive maximum value or the negative maximum value of the received signal 11. The A oscilloscope display may also be displayed on the same monitor as the C oscilloscope display by the arithmetic processing unit 5.

In addition, the arithmetic processing unit 5 executes processing in accordance with instructions input from the input device 12 by the user, such as the designation of the evaluation gate described later or the selection of the peak value of the received signal 11 displayed by the A oscilloscope. The input device 12 may also be a keyboard, a pointing device, etc., for example. In the hard disk 6, a color palette is stored, which defines the colors used according to the waveform of the received signal 11 (especially the size of the peak value) when the C oscilloscope is displayed. The definition of the color, specifically, uses the RYB (Red Yellow Blue) value to establish a correspondence with the waveform of the received signal 11.

In addition, the evaluation of the received signal 11 used for the C oscilloscope display is performed within the scope of the evaluation gate. The evaluation gate is used to extract only the component caused by the reflected wave U2 from the inspection place of the inspection target among the components of the received signal 11 input from the ultrasonic flaw detector 1 and display it as a C oscilloscope. Therefore, the evaluation gate has the function (gate control) to open the gate only at a prescribed time after a prescribed delay time to allow the received signal 11 to pass. The setting of the evaluation gate is performed by the calculation processing unit 5 based on the input from the input device 12, for example. Alternatively, the arithmetic processing unit 5 may analyze the received signal 11 and automatically set it. The arithmetic processing unit 5 is equipped with a gate circuit that generates an evaluation gate. However, it must be confirmed that on the A oscilloscope, the maximum positive peak value and the maximum negative peak value are always included in the range of the evaluation gate. This is because if one or both of the largest positive peak and the largest negative peak are not included in the evaluation gate range, the non-inspection object will be misidentified as the largest or negative peak of the positive peak. The biggest, and I may not be able to do the assessment of the inspection object correctly.

In addition, when the C oscilloscope is obtained from the maximum value of the received signal 11 included 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 oscilloscope.

In the hard disk 6, there are stored a program used to perform the ultrasonic inspection of the first embodiment by the calculation processing unit 5 (a program used to perform the ultrasonic inspection method), a reference signal, a list of the types of inspection objects, and inspections The type of object establishes the information of the related attenuation rate. The reference signal can be obtained by the method shown in FIG. 2. The ultrasonic attenuation rate can be calculated from the product of the attenuation coefficient and the thickness of the inspection object. The attenuation coefficient of ultrasonic waves, for example, can be determined by 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".

The attenuation coefficient of various materials constituting the inspection object is measured, and the attenuation rate can be calculated by the product of the measured attenuation coefficient and the thickness of the inspection object. Register the calculated attenuation rate as a correction parameter and save it in the hard disk 6 (registration step). The arithmetic processing unit 5 assigns an identification code to each saved correction parameter, and establishes a correspondence between the identification code of the correction parameter and the identification code of the inspection object. Thereby, even for inspection objects with various ultrasonic attenuation characteristics, suitable correction parameters (attenuation rates) can still be selected.

Fig. 6 is a GUI (Graphical User Interface) that allows the user to select the type of inspection object. GUI 13 displays a list of the types of inspection objects stored in the hard disk 6. The user selects a desired inspection object from the inspection objects displayed in the list (selection step). The calculation processing unit 5 can create correction parameters corresponding to the identification code of the selected inspection object, and save and load (read in) the correction parameters into the memory area of the calculation processing unit 5. Thereby, the usability of the ultrasonic inspection apparatus 100 will be improved. In addition, the memory in the memory area may exist in one of the outside or inside of the microprocessor, or both.

The hard disk 6 stores the library information of the inspection objects that make the GUI 13 list display. By updating the library information of the inspection objects, the inspection objects listed in the GUI 13 will be updated. It is possible to register the correction parameters corresponding to the updated inspection object identification code. The update of the inventory information of the inspection object can be performed by copying the inventory information of the new inspection object stored in a storage medium such as CDs, DVDs, etc., to the hard disk 6.

Fig. 7 is a GUI for receiving information of the inspection object from the user. The ultrasonic inspection device 100 may also be designed to receive information of the inspection object from the user through the input device 12, and newly generate correction parameters. The ultrasonic inspection apparatus 100 assigns an identification code to each attenuation coefficient of the inspection object in advance, and establishes a connection with the inspection object identification code.

The GUI 14 receives the input of the inspection object and the thickness from the user, and the calculation processing unit 5 calculates the attenuation rate from the attenuation coefficient associated with the inspection object received from the user and the thickness received from the user. The attenuation rate can be calculated from the product of the attenuation coefficient and the thickness. The newly registered attenuation rate is used as the correction parameter and saved in the hard disk 6.

In addition, the arithmetic processing unit 5 assigns an identification code to the newly saved correction parameter, and associates the identification code of the new correction parameter with the identification code of the new inspection object. As described above, by designing to receive the information of the inspection object from the user through the input device 12, and to newly generate correction parameters, the usability of the ultrasonic inspection device 100 is improved.

In addition, the GUI 14 can also allow the user to select multiple materials, and accept the input of thickness for each material. Thereby, even when the inspection object is composed of a plurality of different materials, the inspection result can be obtained accurately.

Fig. 8 is a process flow chart illustrating the procedure of the program for inspecting the internal state of the inspection object in the first embodiment. The arithmetic processing unit 5 executes the processing program stored in the hard disk 6 to check whether there is a defect in the inspection object.

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

In step S3, correction processing of the reference signal strength is performed. The correction process is achieved by multiplying each frequency component of the reference signal by the attenuation rate. _{Specifically, the reference signal r m} (t) after the correction process is obtained by the following formula (1).

這裡，t為時間、α為修正參數、f為頻率、R(f)為參照訊號的傅立葉變換。此外，Real表示複數(complex number)的實部，IFT表示逆傅立葉變換。

Here, t is the time, α is the correction parameter, f is the frequency, and R(f) is the Fourier transform of the reference signal. In addition, Real represents the real part of a complex number, and IFT represents the inverse Fourier transform.

In step S4, the received signal 11 sent from the ultrasonic flaw detector 1 is stored in the memory area of the calculation processing unit 5, and is input to the program.

In step S5, the arithmetic processing unit 5 calculates the pixel value for C oscillometric display. The so-called pixel value is the gradation value of the evaluation value of the received signal 11. For example, in an image of 256 gradation, the pixel value takes a value from 0 to 255. The evaluation value adopts the maximum value of the received signal 11 contained in the evaluation gate. When the maximum value is used, the higher level of the positive and negative peaks in the received signal 11 is selected. The evaluation value is suitably converted into a pixel value so as to fall within the range of 0 to 255, for example. The pixel value calculated in step S5 is stored in the memory area of the arithmetic processing unit 5.

In step S6, the arithmetic processing unit 5 calculates the correlation coefficient by the method described below, and determines whether there is an abnormality in the internal state of the inspection target (abnormality determination). The information that determines the presence or absence of an abnormality in step S6 is stored in the memory area of the arithmetic processing unit 5. In step S7, it is determined whether the processing of all the measurement points has been completed. When the processing of all the measurement points has not been completed (step S7, No), return to step S4, and when the processing of all the measurement points has ended (step S7) , Yes) Go to step S8.

In step S8, the arithmetic processing unit 5 generates a two-dimensional image including the pixel values of all measurement points and information on the presence or absence of abnormalities as an inspection image. In the inspection image generated in step S8, the measurement points determined to be abnormal may be displayed in color, and the measurement points determined to be non-abnormal may be displayed in gray scale. For grayscale display, the pixel value calculated at each measurement point is used. In step S9, the inspection image generated in step S8 is displayed on the monitor 8 (C oscillometric display).

Fig. 9 is a diagram showing how ultrasonic waves are irradiated to an inspection target and the irradiated ultrasonic waves are reflected. The inspection object is an electronic component formed by joining layer L3 and layer L4. A part of the interface between the layer L3 and the layer L4, which is the interface, is peeled off to form a peeling portion. If ultrasonic waves are incident on the peeling part, reflected waves are generated. The phase of this reflected wave is inverted with respect to the phase of the incident wave. Using this phenomenon, it is determined whether there is an abnormality such as peeling inside the inspection object.

FIG. 10 is a diagram illustrating a method of determining whether there is an abnormality in the internal state of the inspection object in the aforementioned step S6. In FIG. 10, the received signal 15 obtained by irradiating an ultrasonic wave to the peeling part is shown. In the received signal 15, the reflected wave (surface echo) reflected on the surface of the layer L3 (refer to FIG. 9) is included in the first half of the time axis direction, and the second half is included in the layer L3 and the peeling part (air) (refer to FIG. 9). The signal of the reflected wave (interface echo) reflected by the interface. The arithmetic processing unit 5 sets the surface echo gate 16 (S gate) in order to extract the starting point of the surface echo from the received signal 15. The calculation processing unit 5 sets the time when the signal intensity of the received signal 15 exceeds the threshold within the range of the surface echo gate 16 as the surface echo start point 17 (trigger point). In addition, in order to extract the interface echo, the arithmetic processing unit 5 sets a time range delayed by a certain time from the surface echo start point 17 in the evaluation gate 18.

Next, the arithmetic processing unit 5 aligns the reference signal 19 in the time axis direction. In the alignment, the positive and negative maximum signal intensity peaks of the received signal 15 in the evaluation gate 18 are used. Figure 10 shows the result of alignment based on the negative maximum signal intensity peak. The calculation processing unit 5 detects the negative maximum signal intensity 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 intensity peak value of the reference signal 19 is consistent with the negative maximum signal intensity peak value 20 of the received signal 15.

When the alignment is completed, the calculation processing unit 5 calculates the correlation coefficient within the time range in 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 the correlation coefficient of a positive value based on the positive maximum signal intensity peak value, compares the correlation coefficient of the negative value and the correlation coefficient of the positive value, and adopts the correlation coefficient of the larger absolute value. When the correlation coefficient of the negative value is large, the interface echo within the range of the evaluation gate 18 is judged as a candidate for peeling. The measurement points judged as candidates for peeling are finally judged as peeling through threshold processing.

FIG. 11 is a GUI for displaying the inspection image on the monitor 8 in the aforementioned step S9. In the GUI 21, in the inspection image display area 22, the area determined to be normal is displayed in gray scale, and the area 23 determined to be abnormal is displayed in color (the inspection image generation step). Thereby, the user can easily grasp the abnormal area.

The GUI 21 can display the correction parameter input in the aforementioned step S2 or the information of the inspection object associated with the identification code of the input correction parameter in the parameter display area 24 (correction parameter display step). Thereby, the usability of the ultrasonic inspection apparatus 100 will be improved.

The GUI 21 accepts input from the user whether to execute the correction process in the aforementioned step S3 (execute the designated step) by using the correction process activation button 25. In addition, when the user does not select the inspection object, the correction processing validation button 25 is grayed out, and the correction processing is invalidated. In this way, it is easy to grasp whether the correction process can be performed.

The inspection image displayed in the inspection image display area 22 can be output as an EXIF (Exchangeable Image File Format) file (output step) and stored in the hard disk 6. The calculation processing unit 5 can also embed the information displayed in the parameter display area 24 into the EXIF file. Specifically, to the exported image electronic file in the EXIF format, write at least one of the loaded correction parameter and the inspection target identification code associated with the loaded correction parameter (writing step). Thereby, the usability of the ultrasonic inspection apparatus 100 will be improved.

Fig. 12 is a GUI showing the result of the correction processing of the reference signal intensity. The GUI 26 displays the original reference signal 27 before the correction process and the reference signal 28 after the signal strength has been corrected. The result of the correction processing is displayed by the GUI 26, so that the reference signal after the correction of the signal strength can be compared with the A oscilloscope of the received signal obtained by inspecting the object displayed on the oscilloscope 7 or the monitor 8. Display (A oscilloscope display step). Thereby, the user can confirm that the waveform of the received signal obtained by inspecting the object is not different from the waveform of the reference signal, and can grasp whether the correction process is executed correctly.

Fig. 13 is a diagram illustrating the vertical structure of an electronic component having a plurality of interfaces with different height levels. In an ultrasonic inspection, multiple interfaces with different height levels are sometimes scanned for abnormalities with a single ultrasonic probe scan. The electronic component 29 has a wafer 30 and a wafer 31 having different heights, and the wafer 30 and the wafer 31 are sealed in the layer L5. If the interface between the wafer 30 and the layer L5 is designated as area 1, or the interface between the wafer 31 and the layer L5 is designated as area 2, the thickness of the layer L5 is different in the area 1 and the area 2, so the ultrasonic attenuation rate Also different. In view of this, it is also possible to use different correction parameters (attenuation rates) in area 1 and area 2 for correction processing. For example, the coordinates of the measurement point and the correction parameter may be linked in advance, and the correction parameter may be switched for each measurement point to perform correction processing of the reference signal intensity. In other words, in the aforementioned registration step, it is sufficient to associate a plurality of different correction parameters with the measurement point coordinates of the received signal and register them in the memory unit. Thereby, the reliability of the inspection result of the inspection object having a plurality of interfaces with different height levels will be improved.

By using the ultrasonic inspection apparatus of the present embodiment described above, even for inspection objects having various ultrasonic attenuation characteristics, it is possible to accurately determine the presence or absence of an abnormality in the inspection object.

"Second Embodiment" In the inspection device of the second embodiment, the cross-correlation signal strength between the reference signal and the received signal obtained from the inspection object is calculated, and based on the calculated cross-correlation signal strength, an ultrasonic image indicating the internal state of the inspection object is obtained . In addition, the configuration 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, so the description of overlapping parts (refer to FIG. 1) is omitted.

In the first embodiment, a pulse signal with a short time width is used for the pulse signal 9, but in the inspection device of the second embodiment, in order to improve the signal-to-noise ratio, the pulse signal 9 has a long time width and is modulated After the signal. In the modulation signal, well-known modulation signals such as chirp signals, frequency offset modulation signals, and phase offset modulation signals can be used. The reference signal can be obtained by the method shown in FIG. 2. In addition, the correction parameters used in the correction processing of the reference signal strength can be selected by the user by the method shown in FIG. 6. In addition, the correction parameters can also be generated by the method shown in FIG. 7.

Fig. 14 is a process flowchart illustrating a procedure of a program for acquiring an ultrasonic image showing the internal state of an inspection target in the second embodiment. This program is stored in the hard disk 6 and executed by the calculation processing unit 5. The processing content of step S1 to step S4 is the same as that of FIG. 8 and therefore the description is omitted. In step S201, the cross-correlation signal of the reference signal after the correction processing in step S3 and the received signal input in step S4 is calculated. The so-called 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 random noise can be removed by the processing of step S201. This is because the correlation between the reference signal and random noise is low.

In step S202, the pixel value for C oscillometric display is calculated from the cross-correlation signal. The so-called pixel value is the gradation value of the evaluation value of the cross-correlation signal. For example, in an image of 256 gradation, the pixel value takes a value from 0 to 255. The evaluation value is calculated using the evaluation gate as in the first embodiment. By setting the evaluation gate for the cross-correlation signal, the evaluation value can be obtained from the maximum value of the cross-correlation signal included in the evaluation gate. At this time, the higher level of the positive and negative peaks of the cross-correlation signal can also be selected and reflected in the evaluation value. The pixel value calculated in step S202 is stored in the memory area of the arithmetic processing unit 5.

The processing content of step S7 is the same as that of FIG. 8 and therefore the description is omitted. In step S203, a gray-scale two-dimensional image is generated as an ultrasonic image from the pixel values of all the measurement points stored in the memory area of the arithmetic processing unit 5. In step S204, an ultrasonic image is displayed on the monitor 8.

FIG. 15 is the GUI used to display the ultrasonic image on the monitor 8 in the aforementioned step S203. GUI 32, in the ultrasound image display area 33, the ultrasound image is displayed in gray scale. Thereby, the usability of the ultrasonic inspection apparatus 100 will be improved.

In the past, when an ultrasonic image was to be obtained based on the strength of the cross-correlation signal, due to the attenuation of the ultrasonic wave inside the inspection object, the waveforms of the reference signal and the received signal obtained using the inspection object were different, resulting in cross-correlation. The problem of reduced signal strength and reduced signal-to-noise ratio. However, in the inspection device of the second embodiment, the reference signal strength is corrected according to the inspection object. Therefore, even for inspection objects with various ultrasonic attenuation characteristics, a high signal-to-noise ratio can be obtained. Ultrasonic image.

"The third embodiment" The ultrasonic inspection apparatus of the third embodiment is designed to be able to implement the present invention by the penetration method. The so-called penetration method refers to a method of inspection using ultrasonic waves that penetrate the inspection object. On the other hand, the inspection method using ultrasonic waves reflected from the inspection object is called the reflection method. One of the advantages of the penetration method is that it shortens the propagation distance of the ultrasonic wave inside the inspection object compared to the reflection method, thereby suppressing the attenuation of the ultrasonic wave and improving the signal-to-noise ratio.

For example, when you want to check whether there is an abnormality in the interface near the bottom surface of the inspection object, if it is the reflection method, the ultrasonic wave will gradually propagate from the surface of the inspection object to the interface adjacent to the bottom surface, and then from the interface adjacent to the bottom surface to the surface. . Therefore, the propagation distance of the ultrasonic wave inside the inspection object is approximately twice the thickness of the sample at the shortest. On the other hand, in the case of the penetration method, the ultrasonic waves only gradually propagate from the surface of the inspection object to the bottom surface, so the shortest propagation distance is equal to the thickness of the sample. Therefore, in the aforementioned case, if the transmission method is used, the propagation distance can be shortened to about half compared to the reflection method.

FIG. 16 is a block diagram showing the structure of an ultrasonic inspection apparatus 500 according to the third embodiment. The ultrasonic inspection device 500, like the ultrasonic inspection device 100, includes an ultrasonic flaw detector 1, an ultrasonic probe 2, a scanning mechanism part 3, a mechanism part controller 4, a calculation processing part 5 (microprocessor), and a hard disk 6 (Memory part), oscilloscope 7 (display device), monitor 8 (display device), input device 12, etc. (refer to FIG. 1). The ultrasonic inspection device 500 further includes an ultrasonic probe 501 for receiving penetrating waves.

The ultrasonic probe 501 is an ultrasonic probe that is transformed into an electronic signal for receiving ultrasonic waves. In the ultrasonic inspection apparatus 100, the ultrasonic probe 2 has both functions of a transmitting mechanism for generating ultrasonic waves and a receiving mechanism for receiving ultrasonic waves. However, in the ultrasonic inspection apparatus 500, the ultrasonic probe 2 functions as a transmitting mechanism. The probe 501 functions as a receiving mechanism.

The scanning mechanism part 3 holds the ultrasonic probe 2 and the ultrasonic probe 501, and causes the ultrasonic probe 2 to be on the inspection object and the ultrasonic probe 501 to scan under the inspection object.

The ultrasonic flaw detector 1 transmits a pulse signal 502 to the ultrasonic probe 2, and the ultrasonic probe 2 converts the pulse signal 502 into an ultrasonic wave and sends an ultrasonic wave U3 to the inspection target 50. In the pulse signal 502, a time-width and modulated signal is used (refer to the second embodiment). The ultrasonic probe 501 converts the penetrating wave U4 that penetrates the inspection object 50 into an electronic signal, and sends the electronic signal 503 to the ultrasonic flaw detector 1. The ultrasonic flaw detector 1 receives the input of the electronic signal 503 to generate a received signal 504 and sends it to the calculation processing unit 5.

The received signal 504 obtained by the arithmetic processing unit 5 is stored in the hard disk 6 (storage unit) as necessary. In addition, the arithmetic processing unit 5 is connected to an oscilloscope 7 (display device) and a monitor 8 (display device), and can perform A-scope display or C-scope display in real time.

The ultrasonic inspection device 500, like the ultrasonic inspection device of the second embodiment, calculates the cross-correlation calculation signal between the reference signal and the received signal obtained from the inspection object, and obtains the representative inspection object based on the calculated cross-correlation signal strength Ultrasonic image of the internal state of the object. In this case, the received signal is obtained by penetrating waves.

Fig. 17 is a diagram illustrating a method of obtaining a reference signal (before correction) in the third embodiment. The ultrasonic probe 2 and the ultrasonic probe 501 are immersed in water 201. The ultrasonic inspection device 500 uses the ultrasonic probe 2 to send an ultrasonic wave U203. The ultrasonic wave U203 propagates in the water 201 and is received by the ultrasonic probe 501. Set the received signal as the reference signal (before correction).

The hard disk 6 stores a program for acquiring an ultrasonic image showing the internal state of the inspection object, and is executed by the arithmetic processing unit 5. The content of the executed processing is the same as in the second embodiment, so the description is omitted (refer to FIG. 14). The correction parameters used in the correction processing of the reference signal strength can be selected by the user by the method shown in FIG. 6. In addition, the correction parameters can also be generated by the method shown in FIG. 7.

With the above constitution, the present invention can be implemented by the penetration method. As described in the second embodiment, when an ultrasonic image is to be obtained based on the strength of the cross-correlation signal, due to the attenuation of the ultrasonic wave inside the inspection object, there are a reference signal and a received signal obtained using the inspection object The waveform is different and the signal-to-noise ratio is reduced. This problem also occurs in the penetrating method. However, in the ultrasonic inspection apparatus 500 of the third embodiment, the reference signal strength is corrected according to the inspection object. Therefore, even for inspection objects with various ultrasonic attenuation characteristics, the penetration method is used. Ultrasonic images with high signal-to-noise ratio can still be obtained.

The ultrasonic inspection method of the present embodiment described above has the following characteristics. The ultrasonic inspection method of this embodiment is a method of irradiating an inspection object with ultrasonic waves, obtaining a received signal from the inspection object, and performing calculation processing related to the received signal and the reference signal (for example, reference signal 19) by the calculation processing unit, based on Ultrasonic inspection method to check the internal state of the inspection object based on the result of related calculation processing. The ultrasonic inspection method has: a registration step, which links the correction parameters specific to the type of the inspection object used to correct the intensity of the reference signal and the inspection object identification code and registers them in the memory; and the loading step (Figure 8) Step S2), load the correction parameters into the calculation processing unit based on the inspection object identification code; and the correction step (for example, step S3 in FIG. 8), use the loaded correction parameters to correct the signal strength of the reference signal; and related calculations Step (for example, step S6 in FIG. 8), perform correlation calculation processing between the received signal and the corrected reference signal. According to the ultrasonic inspection method of this embodiment, it is possible to provide an ultrasonic inspection method capable of accurately obtaining inspection results even for inspection objects having various ultrasonic attenuation characteristics. In addition, the correlation calculation processing may also be processing for obtaining the correlation coefficient between the received signal and the reference signal other than the processing of step S6 in FIG. 8 described above.

The ultrasonic inspection method of this embodiment can be applied by either the reflection method (refer to the first embodiment and the second embodiment) or the transmission method (refer to the third embodiment).

The ultrasonic inspection method has: a selection step, in which the types of inspection objects registered in the aforementioned registration step are displayed in a list on the display device (such as the monitor 8), and the user is allowed to select the inspection objects from the types of inspection objects displayed in the list. The type; in the foregoing loading step, the correction parameters can be loaded into the calculation processing unit based on the type of inspection object selected by the user in the foregoing selection step.

In the aforementioned registration step, based on the result of the information of the inspection object received from the user through the input device, the correction parameter can be newly generated, and the newly generated parameter and the inspection object identification code can be associated and registered in the memory unit (refer to FIG. 7 instruction of).

In the aforementioned registration step, the correction parameter is the attenuation rate that depends on the frequency of the ultrasonic wave (refer to Fig. 6 and the description in Fig. 7).

The ultrasonic inspection method includes a correction parameter display step, which causes the display device to display the inspection object identification code and the correction parameters loaded in the foregoing loading step (refer to the description of FIG. 11).

The ultrasonic inspection method includes: the reference signal A oscillometric display step, and the corrected reference signal is displayed as the A oscilloscope on the display device (refer to the description of FIG. 12).

The ultrasonic inspection method includes: performing a designation step, and accepting a designation from a user whether to perform the aforementioned correction step (refer to the description of FIG. 11).

The ultrasonic inspection method includes: an inspection image generation step, which generates an inspection image based on the relevant calculation processing results; and an output step, which outputs the inspection image in EXIF (Exchangeable Image Format) format; and a writing step, for the output In the image electronic file in EXIF format, write at least one of the loaded correction parameters and the inspection object identification code that is related to the loaded correction parameters.

The ultrasonic inspection method includes: a pixel value calculation step, which calculates the pixel value of a grayscale image from the intensity of the received signal (for example, step S5 in FIG. 8); An inspection image containing information on pixel values and abnormal regions (step S8 in FIG. 8).

The ultrasonic inspection method includes the step of calculating the cross-correlation signal of the cross-correlation function signal of the received signal and the corrected reference signal instead of the aforementioned correlation calculation step (step S201 in FIG. 14); and ultrasonic image generation Step: Generate an ultrasonic image based on the intensity of the cross-correlation function signal (step S203 in FIG. 14).

In the aforementioned registration step, a plurality of different correction parameters and the measurement point coordinates of the received signal are associated and registered in the storage unit (refer to the description of FIG. 13).

In addition, the present invention is not limited to the aforementioned embodiment, but includes various modifications. For example, the aforementioned embodiments are explained in detail in order to explain the present invention in a simple manner, and are not limited to all the explained configurations. In addition, a part of a certain embodiment may be replaced with a configuration of another embodiment, and the configuration of a certain embodiment may be added to the configuration of another embodiment. In addition, with respect to a part of the configuration of each embodiment, other configurations can be added, deleted, or replaced.

In addition, part or all of the aforementioned configurations, functions, processing units, processing means, etc., may also be realized by hardware by, for example, an integrated circuit design or the like. In addition, each of the aforementioned configurations, functions, etc., can also be separately interpreted by the processor to realize the programs for each function, and implemented by software through execution. The programs, tables, files and other information that realize each function can be placed in memory, or hard disk, SSD (Solid State Drive) and other recording devices, or IC card, SD card, DVD and other storage media.

In addition, the control lines or information lines are deemed necessary in the disclosure instructions, and may not reveal all the control lines or information lines on the product. In fact, it can be considered that almost all the components are connected to each other.

1: Ultrasonic flaw detector 2: Ultrasonic probe 3: Scanning mechanism department 4: Institutional Controller 5: Calculation Processing Department 6: Hard Disk (Memory Department) 7: Oscilloscope (A oscilloscope display, display device) 8: Monitor (C oscilloscope display, display device) 9: Pulse signal 10: Electronic signal 11: Receive signal 12: Input device 13,14,21,26,32: GUI 15: Receive signal 16: surface echo gate 17: Starting point of surface echo 18: Evaluation gate 19: Reference signal 20: Negative maximum signal intensity peak 22: Check the image display area 23: Area judged to be abnormal 24: Parameter display area 25: Correct the processing validation button 27: Reference signal (before correction processing) 28: Reference signal (after correction processing) 29: Electronic parts 30, 31: chip 33: Ultrasonic image display area 50: Inspection object 100,500: Ultrasonic inspection device 201: Water 202: Standard test strip 203: Electronic Parts 301: Reference signal (reflected wave on the surface of the standard test piece) 302: Receiving signal (reflected waves inside electronic parts) 401: Power spectrum (reference signal) 402: Power spectrum (received signal) 501: Ultrasonic Probe 502: Pulse Signal 503: Electronic Signal 504: receive signal L1, L2, L3, L4, L5: Layer

[Fig. 1] A block diagram showing the structure of the ultrasonic inspection apparatus of the first embodiment. [Figure 2] A diagram illustrating the method of obtaining a reference signal. [Fig. 3] A diagram illustrating the method of obtaining the received signal when the electronic component is used as the inspection object. [Fig. 4] A diagram showing the reference signal and the waveform of the received signal obtained from the reflected wave inside the electronic component. [Figure 5] A diagram showing the power spectrum of the reference signal and the received signal. [Figure 6] GUI (Graphical User Interface) that allows the user to select the type of inspection object. [Figure 7] GUI used to receive information of inspection objects from users. [Fig. 8] A processing flowchart showing the procedure of the program for inspecting the internal state of the inspection object in the first embodiment. [Fig. 9] A diagram showing how the ultrasonic wave is irradiated to the inspection object, and the irradiated ultrasonic wave is reflected. [Fig. 10] A diagram schematically showing a method of determining whether there is an abnormality in the internal state of an inspection object. [Figure 11] The GUI used to display the inspection image on the monitor. [Figure 12] GUI showing the result of correction processing of reference signal intensity. [Fig. 13] A diagram showing the vertical structure of an electronic component having a plurality of interfaces with different height levels. Fig. 14 is a flowchart showing the processing procedure of a program for acquiring an ultrasonic image showing the internal state of an inspection object in the second embodiment. [Fig. 15] The GUI for displaying the ultrasonic image on the monitor of the second embodiment. [Fig. 16] A block diagram showing the configuration of the ultrasonic inspection apparatus of the third embodiment. [Fig. 17] A diagram illustrating a method of obtaining a reference signal (before correction) in the third embodiment.

Claims (20)

An ultrasonic inspection device, comprising: an ultrasonic probe that receives ultrasonic waves irradiated on an inspection object and converts it into an electronic signal; and an ultrasonic flaw detector that drives the ultrasonic probe to generate a received signal from the electronic signal; and arithmetic processing Section; and storage section; the arithmetic processing section performs correlation calculation processing between the received signal and the reference signal stored in the storage section, and checks the internal state of the inspection object based on the results of the correlation calculation processing. The inspection device is characterized by, The aforementioned calculation processing unit, The correction parameter unique to the type of inspection object used to correct the intensity of the reference signal and the inspection object identification code are linked and registered in the memory section, Load the correction parameters into the aforementioned calculation processing unit based on the aforementioned inspection object identification code, The signal strength of the reference signal is corrected using the loaded correction parameter, and the correlation calculation process between the received signal and the corrected reference signal is performed. Such as the ultrasonic inspection device described in claim 1, in which: The aforementioned calculation processing unit, On the display device, the types of the inspection objects that are registered are displayed in a list, and the user is allowed to select the type of inspection objects from the types of inspection objects displayed in the list. The correction parameter is loaded into the calculation processing unit based on the type of inspection object selected by the user. Such as the ultrasonic inspection device described in claim 1, in which: The aforementioned calculation processing unit, Based on the result of the information of the inspection object received from the user by the input device, a correction parameter is newly generated, and the newly generated parameter and the inspection object identification code are associated and registered in the memory unit. Such as the ultrasonic inspection device recorded in any one of claim 1 to claim 3, wherein: The aforementioned correction parameter is the attenuation rate that depends on the frequency of the ultrasonic wave. Such as the ultrasonic inspection device recorded in any one of claim 1 to claim 3, wherein: The aforementioned calculation processing unit, The display device is made to display the aforementioned inspection object identification code and the aforementioned loaded correction parameter. Such as the ultrasonic inspection device recorded in any one of claim 1 to claim 3, wherein: The aforementioned calculation processing unit, In the display device, the corrected reference signal is displayed as an A-scope. Such as the ultrasonic inspection device recorded in any one of claim 1 to claim 3, wherein: The aforementioned calculation processing unit, Accept from the user the designation of whether to use the loaded correction parameters to correct the signal strength of the reference signal. Such as the ultrasonic inspection device recorded in any one of claim 1 to claim 3, wherein: The aforementioned calculation processing unit, The inspection image is generated based on the results of the aforementioned related calculation processing, Output the aforementioned inspection image in EXIF (Exchangeable Image Format) format, To the exported image electronic file in EXIF format, write at least one of the loaded correction parameter and the inspection object identification code that is related to the loaded correction parameter. Such as the ultrasonic inspection device recorded in any one of claim 1 to claim 3, wherein: The aforementioned calculation processing unit, Calculate the pixel value of the grayscale image from the intensity of the aforementioned received signal, Generate an inspection image including the calculated pixel value and information of the abnormal area. Such as the ultrasonic inspection device recorded in any one of claim 1 to claim 3, wherein: The aforementioned calculation processing unit, Instead of the aforementioned correlation calculation processing, the cross-correlation function signal of the aforementioned received signal and the aforementioned corrected reference signal is calculated, The ultrasonic image is generated based on the intensity of the aforementioned cross-correlation function signal. Such as the ultrasonic inspection device recorded in any one of claim 1 to claim 3, wherein: The aforementioned calculation processing unit, A plurality of different correction parameters are associated with the measurement point coordinates of the received signal and registered in the memory unit. An ultrasonic inspection method is to irradiate an inspection object with ultrasonic waves, obtain a received signal from the inspection object, and perform the relevant calculation processing of the received signal and the reference signal by an arithmetic processing unit, and perform inspection based on the results of the aforementioned relevant calculation processing The aforementioned ultrasonic inspection method of the internal state of the inspection object is characterized in that it has: In the registration step, the correction parameters inherent to the type of the inspection object used to correct the intensity of the reference signal and the inspection object identification code are associated and registered to the memory unit; and The loading step is to load the aforementioned correction parameters into the aforementioned arithmetic processing unit based on the aforementioned inspection object identification code; and The correction step is to use the loaded correction parameters to correct the signal strength of the reference signal; and The relevant calculation step is to perform the relevant calculation processing of the aforementioned received signal and the aforementioned corrected reference signal. Such as the ultrasonic inspection method recorded in claim 12, where: It has: a selection step, in which the types of inspection objects registered in the aforementioned registration step are displayed in a list on the display device, and the user is allowed to select the type of inspection objects from the types of inspection objects displayed in the aforementioned list; In the aforementioned loading step, the aforementioned correction parameters are loaded into the aforementioned calculation processing unit based on the type of inspection object selected by the user in the aforementioned selection step. Such as the ultrasonic inspection method recorded in claim 12, where: In the aforementioned registration step, based on the result of the information of the inspection object received from the user through the input device, a correction parameter is newly generated, and the newly generated parameter and the inspection object identification code are associated and registered in the memory unit. Such as the ultrasonic inspection method recorded in any one of claim 12 to claim 14, wherein: In the aforementioned registration step, the aforementioned correction parameter is an attenuation rate that depends on the frequency of the ultrasonic wave. Such as the ultrasonic inspection method recorded in any one of claim 12 to claim 14, wherein: It has a modified parameter display step, which causes the display device to display the aforementioned inspection object identification code and the modified parameter loaded in the aforementioned loading step. Such as the ultrasonic inspection method recorded in any one of claim 12 to claim 14, wherein: It has: the reference signal A oscillometric display step, in which the aforementioned corrected reference signal is displayed as A oscilloscope on the display device. Such as the ultrasonic inspection method recorded in any one of claim 12 to claim 14, wherein: Having: a pixel value calculation step of calculating the pixel value of the grayscale image from the intensity of the aforementioned received signal; and The inspection image generation step is to generate an inspection image including the aforementioned pixel value and information of the abnormal area after performing the aforementioned related calculation steps. Such as the ultrasonic inspection method recorded in any one of claim 12 to claim 14, wherein: It has the step of calculating the cross-correlation signal of the cross-correlation function signal of the aforementioned received signal and the aforementioned corrected reference signal instead of the aforementioned correlation calculation step; and The ultrasonic image generation step generates an ultrasonic image based on the intensity of the aforementioned cross-correlation function signal. Such as the ultrasonic inspection method recorded in any one of claim 12 to claim 14, wherein: In the foregoing registration step, a plurality of different correction parameters and the measurement point coordinates of the received signal are associated and registered in the memory unit.

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