TWI774260B - Ultrasonic inspection device and ultrasonic inspection method - Google Patents

Abstract

Provided is an ultrasonic inspection method that can accurately obtain inspection results even for inspection objects having various ultrasonic attenuation characteristics. The ultrasonic inspection method has the following steps: a registration step of establishing a relationship between a correction parameter inherent in the type of the inspection object used to correct the intensity of the reference signal and the inspection object identification code, and registering it in a hard disk (6); and a loading step (step S2), loading the correction parameters into the calculation processing unit (5) based on the inspection object identification code; and a correction step (step S3), using the loaded correction parameters to correct the signal strength of the reference signal; and the relevant calculation step ( In step S6), the correlation calculation process between the received signal and the corrected reference signal is performed.

Description

Ultrasonic inspection device and ultrasonic inspection method

The present 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, an inspection object is irradiated with ultrasonic waves, reflected waves generated from the inspection object or transmitted waves that penetrate the inspection object are received, and the state inside the inspection object is inspected based on the received signal. In addition, in the ultrasonic inspection, a correlation calculation process between the received signal and the reference signal is sometimes performed to inspect the state of the inside of the inspection object.

As an ultrasonic inspection method using the above-mentioned correlation calculation process between the received signal and the reference signal, there is, for example, Patent Document 1. Patent Document 1 describes "First, an ultrasonic inspection apparatus uses a standard test piece to obtain a reference waveform from a reflected wave on the surface of the standard test piece." (refer to "First Embodiment" of Patent Document 1). In addition, Patent Document 1 describes 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 positive and negative correlation coefficients. If the correlation coefficient is negative, it is expected that there is a phase inversion. Rotation, that is, the peeling part." (refer to the first embodiment). [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 6602449

[Problems to be Solved by Invention]

In Patent Document 1, it is described that the reference signal used in the correlation calculation process is obtained from the reflected wave on the surface of the standard test piece. However, the attenuation of ultrasonic waves 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 toward the low frequency side with respect 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) ) will cause a difference in waveform. When the difference in waveforms is extremely large, the correlation between the reference signal and the received signal obtained from the reflected wave inside the inspection object may decrease, and the reliability of the inspection result based on the correlation calculation process may decrease. In addition, the attenuation characteristics of ultrasonic waves depend on the material of the object to be inspected, so the degree of difference in waveforms may vary greatly depending on the object to be inspected.

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

In order to solve the aforementioned unsolved problems, the ultrasonic inspection apparatus of the present invention includes: an ultrasonic probe that receives ultrasonic waves irradiated on the inspection object and converts them into electronic signals; and an ultrasonic probe that drives the ultrasonic probe to generate received signals from the electronic signals. Sonic flaw detector; and an arithmetic processing unit; and a memory unit; an arithmetic processing unit that executes correlation arithmetic processing of a received signal and a reference signal stored in the memory unit, and checks the internal state of an inspection object based on the result of the correlation arithmetic processing The inspection apparatus is characterized in that the calculation processing unit associates a correction parameter specific to the type of inspection object for correcting the intensity of the reference signal and the inspection object identification code, and registers it in the memory unit, and based on the inspection object identification code The correction parameters are loaded into the calculation processing unit, the signal strength of the reference signal is corrected using the loaded correction parameters, and the correlation calculation process between the received signal and the corrected reference signal is performed. Other aspects of the present invention will be described in the following embodiments. [Effect of invention]

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

Embodiments for carrying out the present invention will be described in detail with reference to the drawings as appropriate. First, an example in which a difference in waveform occurs between a reference signal obtained from a reflected wave on the surface of a standard test piece and a received signal obtained from a reflected wave from the inside of the inspection object will be described.

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

FIG. 3 is a diagram illustrating a method of acquiring a received signal when an electronic component is used as an inspection object. The electronic component 203 is composed of a layer L1 and a layer L2 of different materials. The ultrasonic inspection apparatus (not shown) uses the ultrasonic probe 2 to inject ultrasonic waves 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 showing 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 Fig. 4 is a waveform when the horizontal axis is taken as the time and the vertical axis is taken as the signal strength. The time taken on the horizontal axis travels in the right direction in Figure 4, and the amplitude taken on the vertical axis is set to 0 at the center, from which the upward direction in Figure 4 indicates positive polarity, and the downward direction indicates negative polarity. The same applies to the waveforms described later in these directions.

Referring to the signal 301, peaks with different polarities appear alternately, and among these peaks, the peak whose amplitude becomes the largest appears in the early stage, and the waveform gradually decreases. Although the received signal 302 obtained from the reflected wave inside the electronic component also appears alternately with peaks of different polarities, the number of peaks or the peak amplitude is different from that of the reference signal 301 . That is, a difference can be seen in the waveforms of the reference signal 301 and the received signal 302 .

FIG. 5 is a diagram illustrating the power spectrum of the reference signal 301 and the received signal 302 . The power spectrum of FIG. 5 is the spectrum when the frequency is taken as the horizontal axis, and the normalized signal intensity after normalization of 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 described above with reference to the figures, a difference in waveform may occur 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 objects of ultrasonic inspections are electronic parts, which have rich variability in material, thickness, and layer structure, and have various attenuation characteristics. Therefore, the degree of difference of the aforementioned waveforms may also vary greatly depending on 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 apparatus 100 includes an ultrasonic flaw detector 1, an ultrasonic probe 2, a scanning mechanism unit 3, a mechanism unit controller 4, an arithmetic processing unit 5 (microprocessor), a hard disk 6 (memory unit), and an oscilloscope 7 ( display device), a monitor 8 (display device), an input device 12, and the like.

The ultrasonic flaw detector 1 is provided with a pulse generator (not shown) for sending a pulse signal 9 to the ultrasonic probe 2, and amplifying and noise for the electronic signal 10 sent from the ultrasonic probe 2. A receiver (not shown) that generates the received signal 11 by removing such 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 converts it into an electronic signal. In addition, the ultrasonic probe 2 is held or driven by the scanning mechanism unit 3 and scans the inspection object. The scanning mechanism 3 is controlled by the mechanism controller 4 .

The ultrasonic flaw detector 1 transmits the pulse wave signal 9 to the ultrasonic probe 2 as described above, and the ultrasonic probe 2 converts the pulse wave signal 9 into ultrasonic waves and sends the ultrasonic wave U1 to the inspection object 50 . In the pulse 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 object 50 into an electronic signal, and transmits the electronic signal 10 to the ultrasonic flaw detector 1 . The ultrasonic flaw detector 1 receives the input of the electronic signal 10 , generates a reception signal 11 , and sends the reception signal 11 to the calculation processing unit 5 . The arithmetic processing unit 5 transmits a control signal to the mechanism unit controller in order to use the ultrasonic probe 2 to scan a suitable part of the inspection object to realize control adjustment. The automatic control (scanning) of the ultrasonic probe 2 is achieved by the system of the arithmetic processing 5→mechanism part controller 4→scanning mechanism part 3→ultrasonic probe 2 .

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

In addition, the so-called "A oscilloscope display" refers to the display of the received signal 11 when the horizontal axis of the oscilloscope 7 is taken as the time and the signal strength of the received signal 11 is taken as the vertical axis. In addition, the so-called "C oscilloscope display" refers to the case where the ultrasonic probe 2 is scanned vertically and horizontally on the inspection object, and the horizontal axis of the movement of the ultrasonic probe 2 is taken as the horizontal axis, and the vertical distance is taken as the vertical axis. The gradation of the evaluation value of the received signal 11 at each measurement point is displayed. The 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 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 according to an instruction input from the input device 12 by the user, such as designation of an evaluation gate described later or selection of a peak value of the received signal 11 displayed by the A-scope. The input device 12 can also be, for example, a keyboard, a pointing element, or the like. In the hard disk 6, a color palette is stored, which defines the color to be used according to the waveform (especially the peak value) of the received signal 11 when the C oscilloscope is displayed. The definition of the color is, specifically, associated with the waveform of the received signal 11 using the RYB (Red Yellow Blue) value.

In addition, the evaluation of the received signal 11 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 site of the inspection object among the components of the received signal 11 input from the ultrasonic flaw detector 1 and display it on a C oscilloscope. Therefore, the evaluation gate has a function (gating control) of opening the gate only for a predetermined time after a predetermined delay time to allow the receiving signal 11 to pass through. The setting of the evaluation gate is performed by the arithmetic processing unit 5 based on, for example, the input from the input device 12 . Alternatively, the calculation processing unit 5 may analyze the received signal 11 and set it automatically. 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 of the positive peak and the maximum of the negative peak are always included in the range of the evaluation gate. This is because if one or both of the maximum positive peak value and the maximum negative peak value are not included in the evaluation gate range, the non-inspection object will be mistakenly identified as the maximum positive peak value or the negative peak value. maximum, and may not be able to correctly evaluate the inspection object.

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 positive and negative peaks in the received signal 11 is selected and reflected on the C oscilloscope.

In the hard disk 6, a program for executing the ultrasonic inspection of the first embodiment by the arithmetic processing unit 5 (a program for performing an ultrasonic inspection method), a reference signal, a list of types of inspection objects, and an inspection are stored. The type of object is associated with decay rate information. The reference signal can be obtained by the method shown in FIG. 2 . The attenuation rate of ultrasound 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 Measured by the method disclosed in 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 from the product of the measured attenuation coefficient and the thickness of the inspection object. The calculated attenuation rate is registered as a correction parameter and stored in the hard disk 6 (registration step). The arithmetic processing unit 5 assigns an identification code to each of the stored correction parameters, and establishes a correspondence between the identification code of the correction parameter and the identification code of the inspection object. This makes it possible to select an appropriate correction parameter (attenuation rate) even for inspection objects having various ultrasonic attenuation characteristics.

FIG. 6 is a GUI (Graphical User Interface) for allowing the user to select the type of inspection object. The 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 among the inspection objects displayed in the list (selection step). The calculation processing unit 5 can store and load (read) correction parameters corresponding to the identification code of the selected inspection object into the memory area of the calculation processing unit 5 . Thereby, the usability of the ultrasonic inspection apparatus 100 is improved. In addition, the memory in the memory area may exist on one or both sides of the microprocessor.

The hard disk 6 stores the library information of the inspection objects displayed in the GUI 13 as a list. By updating the library information of the inspection objects, the inspection objects listed in the GUI 13 are updated. Correction parameters corresponding to the updated inspection object ID can be registered. The update of the holding information of the inspection object can be performed by copying the holding information of the new inspection object stored in a storage medium such as CD or DVD to the hard disk 6 .

FIG. 7 is a GUI for accepting the information of the inspection object from the user. The ultrasonic inspection apparatus 100 may be designed to receive information on the inspection object from the user through the input device 12, and to 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 relationship with the inspection object identification code.

The GUI 14 accepts 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 accepted from the user and the thickness accepted from the user. The attenuation rate can be calculated from the product of the attenuation coefficient and the thickness. The newly registered and calculated attenuation rate is stored in the hard disk 6 as a correction parameter.

In addition, the arithmetic processing unit 5 assigns an identification code to the newly stored 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 being designed 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 apparatus 100 is improved.

In addition, the GUI 14 also enables the user to select a plurality of materials, and accepts 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 with high accuracy.

FIG. 8 is a processing flowchart showing the processing procedure of the program for inspecting the internal state of the inspection object according to the first embodiment. The arithmetic processing unit 5 executes the processing program stored in the hard disk 6 to check the presence or absence of defects in the inspection object.

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

In step S3, the correction processing of the reference signal strength is performed. The correction process is achieved by multiplying the reference signal by the attenuation rate for each frequency component. Specifically, the corrected reference signal rm ( _t ) is obtained by the following equation (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. Also, Real represents a real part of a complex number, and IFT represents an inverse Fourier transform.

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

In step S5, the arithmetic processing unit 5 calculates pixel values for C-scope display. The so-called pixel value is the gradation value of the evaluation value of the received signal 11 . As the evaluation value, the maximum value of the received signal 11 contained in the evaluation gate is used. 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, for example, is suitably transformed into a pixel value in such a way that it falls within the range of 0 to 255. The pixel values calculated in step S5 are stored in the memory area of the arithmetic processing unit 5 .

In step S6, the arithmetic processing unit 5 calculates a correlation coefficient by a method described later, and determines whether or not there is an abnormality in the internal state of the inspection object (abnormality determination). The information on the presence or absence of abnormality determined 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 measuring points has been completed, if the processing of all the measuring points has not been completed (step S7, No), the process returns to step S4, and when the processing of all the measuring points has been completed (step S7 , Yes) to enter step S8.

In step S8, the arithmetic processing unit 5 generates a two-dimensional image including the pixel values of all the measurement points and information on the presence or absence of abnormality 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 grayscale. 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 oscilloscope display).

FIG. 9 is a diagram illustrating a state in which ultrasonic waves are irradiated to an inspection object, and the irradiated ultrasonic waves are reflected. The inspection object is an electronic component in which the layer L3 and the layer L4 are bonded. The bonding surface of the layer L3 and the layer L4, that is, a boundary portion, is partially peeled off to form a peeling portion. When ultrasonic waves are incident on the peeling portion, reflected waves are generated. The phase of the reflected wave is inverted with respect to the phase of the incident wave. Using this phenomenon, it is determined whether or not there is an abnormality such as peeling inside the inspection object.

FIG. 10 is a diagram illustrating a method of determining the presence or absence of 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 (see FIG. 9 ) is included in the first half of the time axis direction, and the second half is included between the layer L3 and the peeling portion (air) (see 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 arithmetic processing unit 5 sets the time when the signal strength of the received signal 15 exceeds the threshold value 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 calculation processing unit 5 sets a time range delayed by a predetermined time from the surface echo start point 17 in the evaluation gate 18 .

Next, the arithmetic processing unit 5 performs alignment of the reference signal 19 in the time axis direction. In alignment, the positive and negative maximum signal strength peaks of the received signal 15 in the evaluation gate 18 are used. Figure 10 shows the alignment results based on the negative maximum signal strength peak. 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 direction of the time axis in such a way that the maximum signal strength peak value of the reference signal 19 is consistent with the negative maximum signal strength 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 value of the correlation coefficient is obtained. Next, the calculation processing unit 5 calculates the correlation coefficient of positive values based on the positive maximum signal strength peak value, compares the correlation coefficient of negative values and the correlation coefficient of positive values, and adopts the correlation coefficient with the larger absolute value. When the correlation coefficient of a negative value is large, the interface echo within the range of the evaluation gate 18 is determined as a peeling candidate. The measurement point determined to be a peeling candidate is finally determined to be peeling or not by 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 as normal is displayed in grayscale, and the area determined as abnormal 23 is displayed in color (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 is improved.

The GUI 21 receives input from the user whether or not to execute the correction process in the aforementioned step S3 (execution designation step) through the correction process validation 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 possible to easily grasp whether or not the correction process can be performed.

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

FIG. 12 is a GUI showing the correction processing result of the reference signal strength. The GUI 26 displays the original reference signal 27 before the correction process and the reference signal 28 whose signal strength has been corrected. The correction processing result is displayed by the GUI 26, whereby the reference signal whose signal strength is corrected can be compared with the A-scope of the received signal obtained by the inspection object displayed on the oscilloscope 7 or the monitor 8 display (A oscilloscope display procedure). Thereby, the user can confirm that the waveform of the received signal obtained by the inspection object does not differ from the waveform of the reference signal, and can grasp whether the correction process is correctly performed.

13 is a diagram showing a vertical structure of an electronic component having a plurality of interfaces having different height levels. In an ultrasound examination, a plurality of interfaces with different height levels are sometimes scanned with a single ultrasound probe to check whether there is any abnormality. The electronic component 29 has the wafer 30 and the 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 defined as the region 1, or the interface between the wafer 31 and the layer L5 is defined as the region 2, the thickness of the layer L5 is different in the region 1 and the region 2, so the attenuation rate of ultrasonic waves Also different. In view of this, it is also possible to use different correction parameters (attenuation rates) in the region 1 and the region 2 to perform the correction process. For example, the coordinates of the measurement points and the correction parameters may be associated in advance, and the correction parameters may be switched for each measurement point to perform the correction processing of the reference signal strength. That is, in the above-mentioned registration step, it is only necessary to associate a plurality of different correction parameters with the coordinates of the measurement point of the received signal and register them in the memory unit. As a result, the reliability of the inspection result for inspection objects having a plurality of interfaces with different height levels can be improved.

By using the ultrasonic inspection apparatus of the present embodiment described above, even for inspection objects having various ultrasonic attenuation characteristics, the presence or absence of abnormalities in the inspection objects can be accurately determined.

"Second Embodiment" In the inspection apparatus according to the second embodiment, the cross-correlation signal intensity between the reference signal and the received signal obtained from the inspection object is calculated, and an ultrasonic image representing the internal state of the inspection object is obtained based on the calculated cross-correlation signal intensity. . 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 the overlapping parts is omitted (see FIG. 1 ).

In the first embodiment, a pulse signal with a short time width is used for the pulse signal 9, but in the inspection apparatus of the second embodiment, in order to improve the signal-to-noise ratio, the pulse signal 9 uses a long time width and is modulated signal after. As the modulation signal, well-known modulation signals such as a chirp signal, a frequency shift modulation signal, and a phase shift modulation signal 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 processing flowchart showing a processing procedure of a program for acquiring an ultrasound image representing the internal state of the inspection object in the second embodiment. This program is stored in the hard disk 6 and executed by the arithmetic processing unit 5 . Since the processing contents of steps S1 to S4 are the same as those of FIG. 8 , the description is omitted. In step S201, a cross-correlation signal between the reference signal corrected in step S3 and the received signal input in step S4 is calculated. The so-called cross-correlation signal is the cross-correlation function of 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 process of step S201. This is because the correlation between the reference signal and random noise is low.

In step S202, the pixel value for the C oscilloscope 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 the calculation of the evaluation value, the evaluation gate is used 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 peak values of the cross-correlation signal can also be selected and reflected to the evaluation value. The pixel values calculated in step S202 are stored in the memory area of the arithmetic processing unit 5 .

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

FIG. 15 is a GUI for displaying the ultrasound image on the monitor 8 in the aforementioned step S203. The GUI 32 displays the ultrasound image in grayscale in the ultrasound image display area 33 . Thereby, the usability of the ultrasonic inspection apparatus 100 is improved.

Conventionally, when an ultrasonic image is to be acquired based on the strength of the cross-correlation signal, the waveform of the reference signal and the received signal obtained using the inspection object are different due to the attenuation of the ultrasonic waves inside the inspection object, resulting in cross-correlation. The problem of reduced signal strength and reduced signal-to-noise ratio. However, in the inspection apparatus of the second embodiment, the correction processing of the reference signal strength is performed according to the inspection object, so even for inspection objects having various ultrasonic attenuation characteristics, a high signal-to-noise ratio can be obtained. Ultrasound image.

"Third Embodiment" The ultrasonic inspection apparatus of the third embodiment is designed so that the present invention can be implemented by the penetration method. The so-called penetration method refers to the method of inspection using ultrasonic waves that penetrate the inspection object. On the other hand, the inspection method using the ultrasonic waves reflected from the inspection object is called the reflection method. One of the advantages of the penetration method is that the propagation distance of the ultrasonic waves inside the inspection object can be shortened more than the reflection method, thereby suppressing the attenuation of the ultrasonic waves and improving the signal-to-noise ratio.

For example, when it is desired to check the presence or absence of abnormalities at the interface close to the bottom surface of the inspection object, in the case of 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 becomes nearly twice the thickness of the sample at the shortest. On the other hand, in the penetration method, ultrasonic waves are only gradually propagated 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 above-mentioned situation, the transmission distance can be shortened by about half compared with the reflection method.

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

The ultrasonic probe 501 is an ultrasonic probe that is converted 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. The probe 501 functions as a receiving mechanism.

The scanning mechanism unit 3 holds the ultrasonic probe 2 and the ultrasonic probe 501, and scans the ultrasonic probe 2 over the inspection object and the ultrasonic probe 501 under the inspection object.

The ultrasonic flaw detector 1 transmits a pulse wave signal 502 to the ultrasonic probe 2 , and the ultrasonic probe 2 converts the pulse wave signal 502 into an ultrasonic wave and transmits the ultrasonic wave U3 to the inspection object 50 . In the pulse wave signal 502, a modulated signal with a time width is used (refer to the second embodiment). The ultrasonic probe 501 converts the penetrating wave U4 penetrating 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 reception signal 504 and sends it to the calculation processing unit 5 .

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

The ultrasonic inspection apparatus 500, like the ultrasonic inspection apparatus of the second embodiment, calculates a cross-correlation calculation signal between the reference signal and the received signal obtained from the inspection object, and obtains a signal indicating the inspection object based on the calculated cross-correlation signal strength. Ultrasound image of the internal state of an 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 the water 201 . The ultrasonic inspection apparatus 500 uses the ultrasonic probe 2 to send out ultrasonic waves U203. The ultrasonic wave U203 propagates through 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 representing the internal state of the inspection object, and is executed by the arithmetic processing unit 5 . The content of the processing to be executed is the same as that of the second embodiment, so the description is omitted (see 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 configuration, the present invention can be implemented by the penetration method. As described in the second embodiment, when an ultrasonic image is to be acquired based on the strength of the cross-correlation signal, there are a reference signal and a received signal obtained using the inspection object due to the attenuation of the ultrasonic waves inside the inspection object. The waveforms are different, and the signal-to-noise ratio is reduced. This problem also occurs in the penetration method. However, in the ultrasonic inspection apparatus 500 of the third embodiment, the correction processing of the reference signal intensity is performed according to the inspection object, so even for inspection objects having various ultrasonic attenuation characteristics, the penetration method Ultrasound images with a 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 the present embodiment is a method of irradiating an inspection object with ultrasonic waves, obtaining a reception signal from the inspection object, and executing a correlation calculation process between the reception signal and a reference signal (for example, the reference signal 19 ) by the calculation processing unit, based on An ultrasonic inspection method for inspecting the internal state of the inspection object based on the result of the calculation process. The ultrasonic inspection method includes: a registration step of correlating a correction parameter specific to the type of the inspection object for correcting the intensity of the reference signal and the inspection object identification code, and registering it in a memory; and a loading step (Fig. 8). Step S2), loading the correction parameters into the calculation processing unit based on the inspection object identification code; and a correction step (eg, step S3 in FIG. 8 ), using the loaded correction parameters to correct the signal strength of the reference signal; and related calculation The step (eg, step S6 in FIG. 8 ) is to perform a correlation calculation process between the received signal and the corrected reference signal. According to the ultrasonic inspection method of the present embodiment, it is possible to provide an ultrasonic inspection method that can accurately obtain inspection results even for inspection objects having various ultrasonic attenuation characteristics. In addition, the correlation calculation process may be a process of obtaining the correlation coefficient between the received signal and the reference signal, other than the process of step S6 in FIG. 8 and the like described above.

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

The ultrasonic inspection method includes a selection step of displaying a list of the types of inspection objects registered in the registration step on a display device (for example, monitor 8), and allowing a user to select an inspection object from among the types of inspection objects displayed in the list. In the loading step, the correction parameters can be loaded into the calculation processing unit based on the type of the inspection object selected by the user in the selecting step.

In the above-mentioned registration step, correction parameters can be newly generated based on the result of the information of the inspection object received from the user through the input device, and the newly generated parameters can be associated with the inspection object identification code and registered in the memory unit (see FIG. 7 ). instruction of).

In the above-mentioned registration step, the correction parameter is the attenuation rate depending 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 aforementioned loading step (refer to the description of FIG. 11 ).

The ultrasonic inspection method includes: a step of oscillometric display of the reference signal A, and a display device makes the corrected reference signal A oscillometric display (refer to the description of FIG. 12 ).

The ultrasonic inspection method includes an execution specifying step, and receiving a specification from a user whether or not to execute the aforementioned correction step (refer to the description of FIG. 11 ).

The ultrasonic inspection method has: an inspection image generation step, which generates an inspection image based on the relevant calculation processing result; and an output step, which outputs the inspection image in EXIF (Exchangeable Image Format) format; In the image electronic file in EXIF format, at least one of the loaded correction parameters and the inspection object identification code associated with the loaded correction parameters is written.

The ultrasonic inspection method has: a pixel value calculation step, which calculates the pixel value of a gray-scale 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 has: instead of the aforementioned correlation calculation step, the step of calculating the cross-correlation signal of the cross-correlation function signal of the received signal and the corrected reference signal (step S201 in FIG. 14 ); and ultrasonic image generation step, generating an ultrasound image based on the intensity of the cross-correlation function signal (step S203 in FIG. 14 ).

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

In addition, this invention is not limited to the said embodiment, Various modification examples are included. For example, the above-mentioned embodiments are described in detail in order to explain the present invention clearly, and are not necessarily limited to all the configurations described. In addition, a part of a certain embodiment may be replaced with the structure of another embodiment, and the structure of another embodiment may be added to the structure of a certain embodiment. In addition, with respect to a part of the structure of each embodiment, other structures may be added, deleted, or replaced.

In addition, each of the above-mentioned structures, functions, processing units, processing means, etc., a part or all of them may be realized by hardware, for example, by designing an integrated circuit or the like. In addition, each of the above-mentioned structures, functions, etc., can be realized by software by deciphering a program for realizing each function by a processor, and executing it. Information such as programs, forms, and files that implement various functions can be placed in memory, hard disk, SSD (Solid State Drive) and other recording devices, or memory media such as IC cards, SD cards, and DVDs.

In addition, control lines or information lines are deemed necessary in the disclosure description, and may not necessarily disclose all control lines or information lines on the article. In fact, almost all of the components can be considered to be interconnected.

1: Ultrasonic flaw detector 2: Ultrasonic probe 3: Scanning Mechanism Department 4: Mechanism controller 5: Calculation processing department 6: Hard disk (memory) 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: Surface echo start point 18: Evaluation brakes 19: Reference signal 20: Negative maximum signal strength peak 22: Check the image display area 23: Areas judged to be abnormal 24: Parameter display area 25:Fixed the processing validation button 27: Reference signal (before correction processing) 28: Reference signal (after correction processing) 29: Electronic Parts 30,31: Wafers 33: Ultrasonic image display area 50: Check the object 100,500: Ultrasonic inspection device 201: Water 202: Standard test piece 203: Electronic Parts 301: Reference signal (reflected wave on the surface of the standard test piece) 302: Receive signal (reflected wave 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: Layers

Fig. 1 is a block diagram showing the configuration of the ultrasonic inspection apparatus according to the first embodiment. [ FIG. 2 ] A diagram illustrating a method of obtaining a reference signal. [ Fig. 3] Fig. 3 is a diagram showing a method of acquiring a reception signal when an electronic component is used as an inspection object. [ Fig. 4] Fig. 4 is a diagram showing the waveforms of the reference signal and the received signal obtained from the reflected wave inside the electronic component. [FIG. 5] A diagram showing the power spectrum of the reference signal and the received signal. [Fig. 6] A GUI (Graphical User Interface) for allowing the user to select the type of inspection object. [FIG. 7] GUI for accepting the information of the inspection object from the user. [ Fig. 8] Fig. 8 is a processing flowchart showing a processing procedure of a program for inspecting the internal state of the inspection object according to the first embodiment. [ Fig. 9] Fig. 9 is a diagram showing a state in which ultrasonic waves are irradiated to an inspection object, and the irradiated ultrasonic waves are reflected. [ Fig. 10] Fig. 10 is a diagram schematically illustrating a method for determining the presence or absence of abnormality in the internal state of the inspection object. [Fig. 11] A GUI for displaying the inspection image on the monitor. [Fig. 12] A GUI showing the correction processing result of the reference signal strength. [ Fig. 13] Fig. 13 is a diagram showing a vertical structure of an electronic component having a plurality of interfaces having different height levels. 14 is a processing flow chart showing a processing procedure of a program for acquiring an ultrasound image representing the internal state of the inspection object in the second embodiment. [ Fig. 15 ] GUI for displaying an ultrasound image on a monitor according to the second embodiment. Fig. 16 is a block diagram showing the configuration of the ultrasonic inspection apparatus according to the third embodiment. Fig. 17 is a diagram showing a method of obtaining a reference signal (before correction) in the third embodiment.

Claims (16)

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 and a storage unit; the calculation processing unit executes a correlation calculation process 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 result of the correlation calculation process. The inspection apparatus is characterized in that the arithmetic processing unit associates a correction parameter specific to the type of inspection object for correcting the strength of the reference signal and the inspection object identification code, and associates the plurality of different correction parameters with the inspection object identification code. The coordinates of the measurement point of the received signal are linked and registered in the memory unit, correction parameters are loaded into the calculation processing unit based on the inspection object identification code, and the signal strength of the reference signal is corrected using the loaded correction parameters , and execute the correlation calculation process between the received signal and the corrected reference signal. The ultrasonic examination apparatus according to claim 1, wherein the arithmetic processing unit displays a list of the types of the registered examination objects on the display device, and allows the user to select from the types of examination objects displayed in the list. The type of the inspection object is loaded into the calculation processing unit based on the type of the inspection object selected by the user. The ultrasonic inspection apparatus according to claim 1, wherein the arithmetic processing unit newly generates correction parameters based on a result of the information of the inspection object received from the user through the input device, and associates the newly created parameters with the inspection object The identification code is linked and registered in the memory unit. The ultrasonic inspection apparatus according to any one of claim 1 to claim 3, wherein the correction parameter is an attenuation rate depending on the frequency of ultrasonic waves. The ultrasonic inspection apparatus according to any one of claim 1 to claim 3, wherein the arithmetic processing unit causes the display device to display the inspection object identification code and the loaded correction parameter. The ultrasonic inspection apparatus according to any one of claim 1 to claim 3, wherein the arithmetic processing unit displays the corrected reference signal as an A-scope on the display device. The ultrasonic inspection device according to any one of claim 1 to claim 3, wherein, The calculation processing unit receives a specification from the user whether to use the loaded correction parameter to correct the signal strength of the reference signal. The ultrasonic inspection apparatus according to any one of claim 1 to claim 3, wherein the calculation processing unit generates an inspection image based on the correlation calculation processing result, and converts the inspection image into EXIF (Exchangeable Image Format) In the format output, at least one of the loaded correction parameter and the inspection object identification code associated with the loaded correction parameter is written into the outputted image electronic file in EXIF format. The ultrasonic examination apparatus according to any one of claim 1 to claim 3, wherein the calculation processing unit calculates the pixel value of the grayscale image from the intensity of the received signal, and generates a pixel value including the calculated pixel value and the abnormality A check image of the area's information. An ultrasonic inspection method is to irradiate an inspection object with ultrasonic waves, obtain a received signal from the inspection object, execute a correlation calculation process between the received signal and a reference signal by an arithmetic processing unit, and perform inspection based on the result of the correlation calculation process. The ultrasonic inspection method for the internal state of the inspection object is characterized by comprising: a registration step of registering the inspection value for correcting the intensity of the reference signal. A correction parameter inherent to the type of the object to be inspected is associated with the inspection object identification code and registered in the memory unit; and a loading step of loading the correction parameter into the calculation processing unit based on the inspection object identification code; and a correction step , using the loaded correction parameters to correct the signal strength of the reference signal; and the related calculation step, executing the correlation calculation process between the received signal and the corrected reference signal; in the registration step, the different complex numbers Each of the correction parameters is associated with the coordinates of the measurement point of the received signal and registered in the memory unit. The ultrasonic inspection method according to claim 10, further comprising: a selection step of displaying the types of inspection objects registered in the registration step on a display device in a list, and instructing the user from among the types of inspection objects displayed in the list The type of the inspection object is selected; in the loading step, the correction parameter is loaded into the calculation processing unit based on the type of the inspection object selected by the user in the selecting step. The ultrasonic inspection method according to claim 10, wherein, in the registration step, correction parameters are newly generated based on a result of the information of the inspection object received from the user through the input device, and the newly created parameters are combined with the inspection object. The identification code is linked and registered in the memory unit. As stated in any one of claim 10 to claim 12 The ultrasonic inspection method, wherein, in the registration step, the correction parameter is an attenuation rate depending on the frequency of the ultrasonic wave. The ultrasonic inspection method according to any one of claim 10 to claim 12, further comprising: a correction parameter display step, wherein the display device displays the inspection object identification code and the correction parameters loaded in the loading step. The ultrasonic inspection method according to any one of claim 10 to claim 12, comprising: the step of oscillometric display of the reference signal A, and the display device makes the corrected reference signal A oscillometric display. The ultrasonic inspection method according to any one of claim 10 to claim 12, comprising: a pixel value calculation step of calculating a pixel value of a grayscale image from the intensity of the received signal; and an inspection image generation step, After the above-mentioned relevant calculation steps are performed, an inspection image including the above-mentioned pixel value and the information of the abnormal area is generated.

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