JP2018189550A - Ultrasonic video device and method for generating ultrasonic video - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic video device and a method for generating an ultrasonic video with which it is possible to set an appropriate time gate and detect a defect with high accuracy in an ultrasonic video device and a method for generating an ultrasonic video for visualizing a defect in a test object as video.SOLUTION: An ultrasonic video device comprises: a time gate setting unit 4 for finding, for each of a defect-free calculation model 4a of a test object 9 and a defect-including calculation model 4a, an ultrasonic wave 8 for propagating the test object 9 by numerical simulation, with a time gate set on the basis of the result of numerical simulation; and a video generation unit 5 for recording the waveforms of ultrasonic waves 8 obtained from the test object 9 by scanning of an ultrasonic probe 1 that transmits the ultrasonic waves 8 and generating an inspection video using the waveforms within the time gate. The time gate is at least part of a time range in which the waveforms of ultrasonic waves 8 obtained by the defect-free calculation model 4a and the waveforms of ultrasonic waves 8 obtained by the defect-including calculation model 4a are different from each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an ultrasound imaging apparatus that visualizes internal voids and peeling of semiconductors and electronic components, and an ultrasound image generation method using the ultrasound imaging apparatus.

  As a non-destructive inspection method for inspecting defects (internal voids and delamination) from inspection images of semiconductors, electronic parts, etc., an ultrasonic image that irradiates the inspection object with ultrasonic waves and generates an ultrasonic image from the reflected waves There is a generation method. This method scans an ultrasonic probe two-dimensionally in the horizontal direction, and uses the amplitude information and time information in the time gate (time range of interest) of the reflected wave from the inspection target part in the inspection target to detect defects. Generate video. When there is a defect in the inspection target and there is a reflected wave derived from the defect in the time gate, the reflected wave of the inspection target with the defect is different from the reflected wave of the healthy inspection target without the defect, It can be observed as a defect image.

  The time gate is a time range in which the waveform of the reflected wave is extracted in order to obtain a defect image. Generally, the distance between the ultrasonic probe and the inspection target, the medium between the ultrasonic probe and the inspection target, and the inspection target It is set based on the arrival time of the reflected wave that can be calculated from the material. When the inspection target is homogeneous, there is almost no reflected wave in the time gate for a healthy inspection target without a defect, and a reflected wave is generated in the time gate for an inspection target with a defect. Can be obtained. However, when the inspection target has a multi-layer structure, even if the inspection target is a healthy inspection target without defects, reflection and transmission of ultrasonic waves occur due to the difference in acoustic impedance of the layer boundary surface, and this phenomenon occurs at multiple layer boundary surfaces. By repeatedly occurring, a plurality of reflected waves interfere and the waveform of the reflected waves becomes complicated. In this case, even if there is a defect on the layer boundary surface, the reflected wave derived from the defect is not necessarily detected at the estimated arrival time, and it is difficult to detect the defect with high accuracy.

  As an example of a conventional technique for solving such a problem when inspecting an inspection object having a multilayer structure, Patent Literature 1 discloses a porosity evaluation method and a porosity evaluation device in a composite material. In the technique described in Patent Document 1, the presence / absence of a defect is directly compared with the waveform evaluation information (time-frequency analysis result) by numerical simulation and the actually received waveform evaluation information (time-frequency analysis result). Determine.

JP, 2015-121516, A

  The technique described in Patent Document 1 directly compares the waveform evaluation information (time-frequency analysis result) by numerical simulation with the actually received waveform evaluation information (time-frequency analysis result) to determine whether there is a defect. Therefore, it is appropriate for manual inspection for determining the presence or absence of a defect at one measurement point. However, since the ultrasonic imaging device uses the principle of generating an image (defect image) based on the difference in waveform depending on the presence or absence of a defect in the time gate, an appropriate time gate is selected so that the waveform varies depending on the presence or absence of a defect. Must be able to be set. In particular, when inspecting an inspection object with a multilayer structure, the waveform of the reflected wave becomes complicated and the accuracy of defect detection decreases unless the time gate is set appropriately. In order to obtain video, it is necessary to set the time gate appropriately. The conventional technology such as the technology described in Patent Document 1 does not consider such a problem.

  The present invention has been made in view of the above, and it is possible to set an appropriate time gate in an ultrasonic image apparatus and an ultrasonic image generation method for visualizing a defect to be inspected, and accurately detect the defect. It is an object of the present invention to provide an ultrasonic image apparatus and an ultrasonic image generation method that can be performed.

  An ultrasonic imaging apparatus according to the present invention receives an ultrasonic probe that transmits an ultrasonic wave to an inspection object and scans the inspection object, and a calculation model of the inspection object, and propagates the inspection object using the calculation model The ultrasonic wave to be obtained is obtained from a numerical simulation, and a time gate setting unit configured to set a time gate that is a time range based on the result of the numerical simulation, and from the inspection target by scanning the ultrasonic probe An image generation unit configured to record the obtained ultrasonic waveform and generate an inspection image of the inspection object using the waveform in the time gate; The time gate setting unit, as the calculation model, is input a calculation model without a defect in which the defect to be inspected is not set and a calculation model with a defect in which the defect is set, and the calculation model without the defect The ultrasonic wave propagating through the inspection object for each of the calculation models with defects is obtained by the numerical simulation. The time gate is at least a part of a time range in which the waveform of the ultrasonic wave determined by the calculation model without defects and the waveform of the ultrasonic wave determined by the calculation model with defects are different from each other. is there.

  According to the present invention, in an ultrasonic imaging apparatus and an ultrasonic image generating method for visualizing a defect to be inspected, an ultrasonic imaging apparatus capable of setting an appropriate time gate and detecting a defect accurately. And an ultrasonic image generating method.

1 is a diagram schematically showing an overall configuration of an ultrasound imaging apparatus according to Embodiment 1 of the present invention. It is a figure which shows reflection and permeation | transmission of the ultrasonic wave which arises in a layer interface, when an ultrasonic wave is irradiated to the test object which has a multilayer structure. It is a figure which shows the example of the setting screen of the structural information of the calculation model of the test object which the ultrasonic imaging device by Example 1 uses. FIG. 5 is a diagram illustrating an example of a setting screen for setting physical property information of a calculation model to be inspected, which is used by the ultrasound imaging apparatus according to the first embodiment. 3 is a flowchart illustrating a procedure of an ultrasonic image generation method according to the first embodiment. In Example 1, it is a figure which shows the example of the calculation model without a defect displayed on the structure information reference figure of the setting information of the structure information of a calculation model. In Example 1, it is a figure which shows the example of the calculation model with a defect displayed on the structure information reference figure of the setting screen of the structure information of a calculation model. In Example 1, it is a result of the simulation which the time gate setting part performed, and is a figure which shows the example of the received waveform in the calculation model without a defect. In Example 1, it is a result of the simulation which the time gate setting part performed, and is a figure which shows the example of the received waveform in the calculation model with a defect. It is a figure which shows the example of the setting screen of the structural information of the calculation model of a test object which the ultrasonic imaging device by Example 2 of this invention uses.

  In the ultrasonic imaging apparatus and the ultrasonic image generation method, ultrasonic waves are applied to an inspection target such as a semiconductor or electronic component, and a reflected wave (or an inspection target) from a defect (an internal void or separation of the inspection target) is detected. A defect is detected by detecting a transmitted wave), and an image of the defect is generated. When the inspection object has a multilayer structure, when the inspection object is irradiated with ultrasonic waves, reflection and transmission of the ultrasonic waves occur at the layer boundary surface.

  FIG. 2 is a diagram showing reflection and transmission of ultrasonic waves generated at the layer boundary surface when an ultrasonic wave is irradiated onto an inspection object having a multilayer structure. The inspection object 9 has a multi-layer structure including silicon layers 91a, 91b, 91c, and 91d and non-conductive film layers 92a, 92b, and 92c positioned therebetween. It is assumed that the non-conductive film layer 92 b has a defect 93.

  The ultrasonic wave 8 irradiated to the inspection object 9 is reflected by the defect 93 and reflected by the layer boundary surface. Since the ultrasonic waves 8 are reflected by the defect 93 and the plurality of layer boundary surfaces, and the plurality of reflected waves interfere with each other, the waveform of the reflected waves from the inspection object 9 becomes complicated. For this reason, in the inspection object 9 having a multilayer structure, it is difficult to accurately detect the defect 93 and visualize the defect 93.

  In the ultrasonic image apparatus and the ultrasonic image generation method according to the present invention, particularly when an inspection object 9 having a multilayer structure is inspected to generate an ultrasonic image of a defect, a time gate of a reflected wave from the inspection object 9 (focused) By appropriately setting the time range), it is possible to detect the defect 93 with high accuracy and to image the defect 93 with high accuracy.

  Hereinafter, an ultrasonic image apparatus and an ultrasonic image generation method according to embodiments of the present invention will be described with reference to the drawings.

  In the first embodiment of the present invention, the ultrasonic probe transmits (irradiates) ultrasonic waves to the inspection target, and the ultrasonic probe (reflected wave) reflected by the inspection target is received by the ultrasonic probe and reflected from the inspection target. A measurement method for generating an image of a defect from a wave waveform, that is, a method for inspecting a defect to be inspected by a so-called reflection method will be described.

  FIG. 1 is a diagram schematically showing the overall configuration of an ultrasonic imaging apparatus according to a first embodiment of the present invention together with an inspection object. The ultrasonic imaging apparatus includes an ultrasonic probe 1, a pulse transmitter / receiver 2, an A / D converter 3, a time gate setting unit 4, an image generation unit 5, and a display unit 6. The inspection object 9 is installed in water of a water tank containing water 7.

  The ultrasonic probe 1 is connected to the pulse transmitter / receiver 2 through a coaxial cable, irradiates (transmits) the ultrasonic wave 8 to the inspection object 9, and scans the inspection object 9. As the ultrasonic probe 1, a commercially available ultrasonic probe for water immersion that is acoustic impedance matched so that the ultrasonic wave 8 can be efficiently transmitted to and received from the water 7 can be used.

  The pulse transmitter / receiver 2 is connected to the A / D converter 3 through a coaxial cable, applies a driving voltage to the ultrasonic probe 1, receives an electric signal from the ultrasonic probe 1, and amplifies the received electric signal. Output to the A / D converter 3. A commercially available ultrasonic pulsar receiver can be used for the pulse transceiver 2.

  The A / D converter 3 converts the waveform of the electrical signal output from the pulse transmitter / receiver 2 (the waveform of the analog signal of the ultrasonic wave 8) into a digital signal waveform. As the A / D converter 3, for example, a commercially available external A / D converter or a board-type A / D converter built in a computer can be used.

  The time gate setting unit 4 uses the calculation model 4a of the inspection object 9 to obtain the ultrasonic wave 8 that propagates through the inspection object 9 (including the ultrasonic wave 8 that reflects and transmits within the inspection object 9) by numerical simulation. The time gate is set based on the result of this numerical simulation. The time gate setting unit 4 can be configured by a commercially available computer, and the propagation of the ultrasonic wave 8 can be obtained by numerical simulation using an existing ultrasonic simulator. Further, the time gate setting unit 4 can also obtain a defect image (simulation image 4b) for one or a plurality of time gates for the waveform of the ultrasonic wave 8 obtained by the numerical simulation.

  The video generation unit 5 receives the waveforms of a plurality of digital signals output from the A / D converter 3 and the time gate output from the time gate setting unit 4, and inspects by mechanical scanning of the ultrasonic probe 1. The amplitude information of the waveform of the digital signal obtained at a plurality of positions of the object 9 is extracted in the range of the time gate, and the inspection video of the inspection object 9 is generated. The video generation unit 5 can be configured with a commercially available computer.

  The display unit 6 displays a screen for operating the time gate setting unit 4 and the video generation unit 5, an inspection video generated by the video generation unit 5, and a commercially available liquid crystal monitor.

  An example of a setting screen for the calculation model 4a of the inspection target 9 for operating the time gate setting unit 4 will be described with reference to FIGS. These setting screens 10 and 11 are displayed on the display unit 6.

  FIG. 3 is a diagram illustrating an example of the setting information screen 10 for the structure information of the calculation model 4a of the inspection target 9 used by the ultrasonic imaging apparatus according to the present embodiment. In the structure information setting screen 10, a structure information setting table 10a that is a table for setting the structure information of the inspection object 9 and a structure information reference that visually illustrates the structure information set in the structure information setting table 10a. FIG. 10b is displayed.

  In the structure information setting table 10a, for each “No.” cell indicating the position of the layer, the distance or thickness of the substance entered in the “substance” cell and the substance entered in the “substance” cell are set. The cell of “distance / thickness” to be input is provided. In the “substance” cell, a pre-registered substance can be selected from a pull-down menu. In the “distance / thickness” cell, numerical values can be input. For the water of the layer L0, the distance between the ultrasonic probe 1 and the epoxy resin of the layer L1 (between the ultrasonic probe 1 and the epoxy resin of the layer L1). The thickness of each of the materials for the layers L1 to L8 is input. In FIG. 3, “∞” (infinity) is input to the “distance / thickness” cell of the water of the layer L9 because the ultrasonic wave 8 incident on the water of the layer L9 is the water of the layer L9. Is transmitted and not reflected (the ultrasonic wave 8 does not return to the ultrasonic probe 1 from the water of the layer L9).

  The structural information reference diagram 10b illustrates the calculation model 4a (including water as a medium) of the inspection object 9 based on the structural information set in the structural information setting table 10a. The structural information reference FIG. 10 b can also illustrate the modeled ultrasonic probe 1. The substances input in the “substance” cell of the structure information setting table 10a are stacked from a position close to the ultrasonic probe 1 to a position far from the ultrasonic probe 1 in the order from the top to the bottom of the structure information setting table 10a. (L0 to L9) is determined. With reference to the structural information reference diagram 10b, the position and thickness of each material layer can be visually displayed.

  FIG. 4 is a diagram illustrating an example of the physical property information setting screen 11 of the calculation model 4a of the inspection target 9 used by the ultrasonic imaging apparatus according to the present embodiment. The physical property information setting screen 11 displays a table for setting physical property information of the inspection object 9. The values in this table are used as the physical property information of the substances input to the structure information setting table 10a. FIG. 4 shows an example of the setting screen 11 for inputting “density”, “longitudinal wave sound velocity”, and “acoustic impedance” as physical property values. The table displayed on the physical property information setting screen 11 includes a “substance” cell in which the substance name is input, and “density” and “longitudinal wave” in which the physical property value of the substance input in the “substance” cell is input. “Sonic velocity” and “acoustic impedance” cells. Note that physical property values other than those described above may be input to the setting screen 11.

  Although not shown in FIGS. 3 and 4, a defect (void or peeling) can be set in the calculation model 4 a of the inspection object 9. In order to set a defect in the calculation model 4a, it is assumed that the defect setting screen displayed on the display unit 6 assumes that there is a defect of the inspection object 9 and that air exists at the position of the defect. Enter the conditions (ie, the defect is modeled with air). The position that is assumed to be defective is the position that is expected to be defective, and can be, for example, part of the layer L5 of the non-conductive film.

  FIG. 5 is a flowchart showing the procedure of the ultrasonic image generating method according to this embodiment. The ultrasonic image generation method according to the present embodiment will be described with reference to FIG. The ultrasonic image generation method according to the present embodiment is executed using the ultrasonic image apparatus according to the present embodiment.

  Step S101 is a step of setting the calculation model 4a of the inspection object 9 in the time gate setting unit 4. The operator of the ultrasound imaging apparatus inputs the structural information of the inspection object 9 using the structure information setting screen 10 of the calculation model 4a and uses the physical property information setting screen 11 of the calculation model 4a. Enter the physical property information. The operator sets two identical calculation models 4a, and sets a defect in one calculation model 4a. That is, the operator uses a time gate to calculate the calculation model 4a (defect-free calculation model 4a1 in FIG. 6A) and the calculation model 4a (defect-added calculation model 4a2 in FIG. 6B) in which the defect 93 is set. Input to the setting unit 4. The calculation model 4a1 without a defect and the calculation model 4a2 with a defect are the same except for the presence or absence of the defect 93. In addition, the operator determines the conditions of the ultrasonic wave 8 (frequency, waveform shape, irradiation position on the inspection object 9, etc.) that the ultrasonic probe 1 transmits to the inspection object 9, and the ultrasonic probe 1 that transmitted the ultrasonic wave 8. A condition for receiving the reflected wave (that is, inspecting the defect of the inspection object 9 by the reflection method) is set in the time gate setting unit 4.

  Step S102 is a step of executing a simulation of propagation of the ultrasonic wave 8 (including reflection and transmission of the ultrasonic wave 8 within the inspection object 9). The time gate setting unit 4 obtains the ultrasonic wave 8 propagating through the inspection object 9 by a numerical simulation using the calculation model 4a of the inspection object 9 by the operation of the operator, and the waveform of the reflected wave of the ultrasonic wave 8 (ultrasonic probe) 1) is obtained. The simulation is executed for each of the calculation model 4a1 without defects and the calculation model 4a2 with defects.

  Step S103 is a step of setting the time gate used for the actual inspection of the inspection object 9 in the time gate setting unit 4. The time gate is set based on the result of the simulation executed by the time gate setting unit 4 in step S102 (the waveform of the reflected wave received by the ultrasonic probe 1). A method for setting the time gate will be described later with reference to FIGS. 6A to 6D. The time gate set in the time gate setting unit 4 is output from the time gate setting unit 4 to the video generation unit 5.

  Step S104 is a step in which the ultrasonic probe 1 is scanned and the waveform of the ultrasonic wave (reflected wave) obtained from the inspection object 9 is recorded. The operator scans the ultrasonic probe 1 and actually inspects the inspection object 9. The image generation unit 5 records the waveform of the reflected wave from the inspection object 9 (the waveform of the reflected wave received by the ultrasonic probe 1) by the scanning of the ultrasonic probe 1 and the reflection within the time gate by the operation of the operator. The maximum amplitude value of the wave waveform is obtained. The time gate set in step S103 is used for this time gate.

  Step S <b> 105 is a step in which the video generation unit 5 generates an inspection video of the inspection object 9. The video generation unit 5 generates an inspection video (defective video) of the inspection target 9 by using the maximum amplitude value obtained in step S104 by the operation of the operator. Existing technology can be used to generate the inspection video. The maximum amplitude value of the reflected wave waveform is used to calculate the luminance of the inspection image.

  A method for setting the time gate in step S103 will be described with reference to FIGS. 6A to 6D.

  6A and 6B are diagrams showing examples of the calculation model 4a (including water as a medium) displayed in the structure information reference diagram 10b (FIG. 3) of the structure information setting screen 10 of the calculation model 4a. 6A is an example of a calculation model 4a1 without defects (calculation model 4a assuming that the inspection object 9 is healthy), and FIG. 6B is a calculation model 4a2 with defects (the inspection object 9 has a defect 93). This is an example of a calculation model 4a) that assumes this. As shown in FIG. 6B, in the calculation model 4a2 with a defect, a defect 93 is set in the layer L5 of the non-conductive film. 6A and 6B also show the modeled ultrasonic probe 1 together with the calculation model 4a1 without defects and the calculation model 4a2 with defects.

  FIG. 6C and FIG. 6D are diagrams showing examples of the waveform (received waveform) of the reflected wave received by the ultrasonic probe 1 as a result of the simulation executed by the time gate setting unit 4 in step S102. 6C is an example of the reception waveform 12 in the calculation model 4a1 without defects, and FIG. 6D is an example of the reception waveform 13 in the calculation model 4a2 with defects. As described above, it is assumed that air exists at the position of the defect 93.

  As shown in FIG. 6C, the received waveform 12 includes a reflected waveform 12a that appears first, and a reflected waveform 12b that appears thereafter. The reflected waveform 12a is a waveform of a reflected wave that has propagated at the shortest distance without multiple reflection from the boundary surface between the layer L1 (epoxy resin) and the layer L2 (silicon) shown in FIG. 6A. The reflected waveform 12b is a waveform of a reflected wave formed by interference of a reflected wave waveform other than the reflected waveform 12a, such as a reflected wave from the boundary surface between the layer L2 (silicon) and the layer L3 (non-conductive film). That is, the reflected waveform 12b includes a reflected wave from the interface between the layers L2 and L3, a reflected wave from the interface between the layers L3 and L4, a reflected wave from the interface between the layers L4 and L5, and the layers L5 and L5. The reflected wave from the boundary surface of L6, the reflected wave from the boundary surface of the layers L6 and L7, the reflected wave from the boundary surface of the layers L7 and L8, the reflected wave from the boundary surface of the layers L8 and L9, the layer L1 And the reflected wave propagated from the boundary surface of the layer L2 other than the shortest distance, and the reflected wave waveform propagated from the boundary surface of the layer L0 and the layer L1 other than the shortest distance interfered with each other.

  As shown in FIG. 6D, the received waveform 13 includes a reflected waveform 13a that appears first and a reflected waveform 13b that appears thereafter. Similar to the reflected waveform 12a, the reflected waveform 13a is a waveform of a reflected wave that is propagated at the shortest distance without multiple reflection from the boundary surface between the layer L1 (epoxy resin) and the layer L2 (silicon) shown in FIG. 6B. is there. The reflected waveform 13b is a waveform of a reflected wave formed by interference with a waveform of a reflected wave other than the reflected waveform 13a, such as a reflected wave from the boundary surface between the layer L2 (silicon) and the layer L3 (nonconductive film).

  As can be seen from FIGS. 6C and 6D, the reflected waveform 13b of the received waveform 13 in the calculation model 4a2 with a defect is different from the reflected waveform 12b of the received waveform 12 in the calculation model 4a1 without a defect due to the influence of the defect 93. It is a waveform. At least a part of the time range in which the reception waveform 12 and the reception waveform 13 are different from each other is set as a time gate. The operator of the ultrasonic imaging apparatus can visually compare the received waveform 12 and the received waveform 13 and set a time range in which these waveforms are different from each other as a time gate. That is, the operator can set at least a part of the time range in which the reflected waveform 12b and the reflected waveform 13b exist as a time gate. In addition, the time gate setting unit 4 calculates the difference in amplitude between the reception waveform 12 and the reception waveform 13 and can set at least a part of the time range in which the difference is larger than a predetermined threshold as the time gate. . In this manner, the time gate can be set by the operator, or can be automatically set by the ultrasonic imaging apparatus.

  The length of the time gate can be arbitrarily determined. That is, the entire time range in which the reception waveform 12 and the reception waveform 13 are different from each other may be set as the time gate, or a part of this time range may be set as the time gate. The length of the time gate can be determined, for example, according to which layer of the inspection object 9 having a multilayer structure is expected to be defective. If the received waveform 12 and the received waveform 13 are within different time ranges, a plurality of time gates can be set. When a plurality of time gates are set, step S104 and step S105 of FIG. 5 are executed for each time gate to generate an inspection video of the inspection object 9.

Here, the effect of setting the time gate using the received waveform obtained by the simulation will be described in detail. The time for the ultrasonic probe 1 to receive the reflected wave from the boundary surface between the layer L4 (silicon) and the layer L5 (non-conductive film) and the reflection from the boundary surface between the layer L1 (epoxy resin) and the layer L2 (silicon). The time difference Δt with respect to the time at which the ultrasonic probe 1 receives the wave is assumed that the ultrasonic wave has propagated at the shortest distance without multiple reflection. From FIGS. 3 and 4, the thicknesses of the layers L2 and L4 (silicon) Is 150 μm, the longitudinal acoustic velocity of ultrasonic waves in silicon is 8600 m / s, the thickness of the layer L3 (nonconductive film) is 20 μm, and the longitudinal acoustic velocity of ultrasonic waves in the nonconductive film is 2540 m / s. ,
Δt = 150 × 2 × 2/8600 + 20 × 2/2540 = 0.086 (μs)
Can be calculated. Therefore, the reflected waveform of the defect 93 appears at time t1 delayed by time Δt from the reflected waveform 13a (FIG. 6D).

  However, as can be seen from FIGS. 6C and 6D, at time t1 delayed by time Δt from the reflected waveforms 12a and 13a, the difference between the reflected waveform 12b and the reflected waveform 13b is slight. There is a large difference between 12b and the reflected waveform 13b. This is a phenomenon caused by the multiple reflection of ultrasonic waves in the inspection object 9 having a multilayer structure. By using the received waveform obtained by the simulation, it is possible to estimate the time (the time after time t1 in FIG. 6D) at which the reflected wave derived from the defect 93 appears in consideration of the influence of multiple reflection. It is possible to set an appropriate time gate for accurately detecting.

  The effects of the ultrasonic image apparatus and the ultrasonic image generation method according to this embodiment will be described.

  The ultrasonic imaging apparatus generates an image (defect image) based on the difference in the waveform of the reflected wave depending on the presence / absence of a defect within the time gate (time range for extracting the waveform), so that the waveform varies depending on the presence / absence of the defect. It is necessary to be able to set an appropriate time gate. In particular, when inspecting an inspection object with a multilayer structure, the waveform of the reflected wave becomes complicated and the accuracy of defect detection decreases unless the time gate is set appropriately. In order to obtain video, it is necessary to set the time gate appropriately.

  In the ultrasonic imaging apparatus and the ultrasonic image generation method according to the present embodiment, a numerical simulation is performed on both the calculation model without defects and the calculation model with defects to determine the waveform of the reflected wave of the ultrasonic wave. A time gate is set based on the waveform of the reflected wave. For this reason, it is possible to set an appropriate time gate for accurately detecting the defect, and even when the inspection target has a multilayer structure and the waveform of the reflected wave is complicated, the defect is accurately detected and the accuracy is high. An image of the defect can be obtained.

  In the second embodiment of the present invention, the ultrasonic imaging apparatus includes a transmission ultrasonic probe and a reception ultrasonic probe, and the transmission ultrasonic probe transmits (irradiates) ultrasonic waves to the inspection target to scan the inspection target. , A measuring method in which an ultrasonic wave (transmitted wave) transmitted through an inspection object is received by a receiving ultrasonic probe and an image of a defect is generated from the waveform of the transmitted wave received by the receiving ultrasonic probe; A method for inspecting defects will be described.

  When inspecting a defect to be inspected by the transmission method, the structure information of the calculation model to be inspected and using two ultrasonic probes, that is, an ultrasonic probe for transmission and an ultrasonic probe for reception, are inspected by the reflection method. Unlike the case of inspecting the defect (Example 1), other points such as the procedure of the ultrasonic image generation method including the time gate setting method are the same as the case of inspecting the defect to be inspected by the reflection method. . In the following, with respect to differences from the first embodiment, an ultrasonic imaging apparatus and an ultrasonic image generation method according to the present embodiment will be described.

  FIG. 7 is a diagram illustrating an example of the structure information setting screen 20 of the calculation model 4a (including water as a medium) of the inspection target 9 used by the ultrasonic imaging apparatus according to the present embodiment. Similar to the structure information setting screen 10 in the first embodiment shown in FIG. 3, the structure information setting screen 20a and the structure information reference diagram 20b are also displayed on the structure information setting screen 20 in the present embodiment. The structural information reference diagram 20b can display the modeled ultrasonic probes (the transmitting ultrasonic probe 21 and the receiving ultrasonic probe 22).

  In the transmission method, the inspection object 9 (the calculation model 4a in FIG. 7) is located between the transmission ultrasonic probe 21 and the reception ultrasonic probe 22. The ultrasonic wave 8 transmitted from the transmission ultrasonic probe 21 passes through the inspection object 9 and is received by the reception ultrasonic probe 22. Using the waveform of the ultrasonic wave 8 (transmitted wave) received by the receiving ultrasonic probe 22, a defect image is generated. In this embodiment, the waveform of the transmitted wave received by the reception ultrasonic probe 22 is obtained by numerical simulation, a time gate is set based on the obtained waveform of the transmitted wave, and a defect image is generated using the time gate. To do. This structure is reflected in the structure information reference diagram 20b.

  In the present embodiment, in the structure information setting table 20a, the distance between the acrylic of the layer L8 and the ultrasonic probe for reception 22 (the acrylic of the layer L8 and the supersonic wave for reception) is stored in the “distance / thickness” cell of the water of the layer L9. The thickness of water between the acoustic probe 22 and the acoustic probe 22 is input. The transmission method is performed by inputting a finite numerical value instead of “∞” (infinity) into the “distance / thickness” cell of the water in the layer L9, that is, the transmission ultrasonic probe 21 and the reception. It can be seen that the defect to be inspected is inspected using the ultrasonic probe 22. Further, the operator says that the reception ultrasonic probe 22 receives the ultrasonic wave 8 transmitted from the transmission ultrasonic probe 21 and transmitted through the inspection object 9 (that is, inspects the defect of the inspection object 9 by the transmission method). The condition can be set in the time gate setting unit 4 in step S101 of the flowchart shown in FIG.

  In the present embodiment, in step S102 of the flowchart shown in FIG. 5, the time gate setting unit 4 obtains the waveform of the transmitted wave of the ultrasonic wave 8 (the waveform received by the receiving ultrasonic probe 22) by numerical simulation. In step S103, a time gate is set based on the waveform of the transmitted wave obtained in step S102. The time gate can be set in the same manner as in the first embodiment from the waveform of the transmitted wave obtained with the calculation model without defects and the waveform of the transmitted wave obtained with the calculation model with defects. In step S104, the operator scans the transmission ultrasonic probe 21, and the video generation unit 5 records the waveform of the transmitted wave of the inspection object 9 received by the reception ultrasonic probe 22, and the time set in step S103. The maximum amplitude value of the waveform of the transmitted wave in the gate is obtained.

  Since the ultrasonic imaging apparatus according to the present embodiment includes the transmission ultrasonic probe 21 and the reception ultrasonic probe 22, the pulse transmitter / receiver 2 (FIG. 1) applies a drive voltage to the transmission ultrasonic probe 21. The electrical signal from the reception ultrasonic probe 22 is received, and the received electrical signal is output to the A / D converter 3.

  The effects of the ultrasonic image apparatus and the ultrasonic image generation method according to this embodiment will be described. In the ultrasonic imaging apparatus and the ultrasonic image generating method according to the present embodiment, when a defect to be inspected is inspected by the transmission method, an appropriate time gate can be set for accurately detecting the defect. For this reason, even if the inspection target has a multi-layer structure and the number of layers to be inspected is large and it is difficult to obtain a defect image by the reflection method, the defect is detected accurately by the transmission method, and an accurate defect image is obtained. Can be obtained.

  In addition, this invention is not limited to said Example, A various deformation | transformation is possible. For example, the above-described embodiments are described in detail for easy understanding of the present invention, and the present invention is not necessarily limited to an aspect including all the configurations described. In addition, a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment. It is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to delete a part of the configuration of each embodiment or to add or replace another configuration.

  DESCRIPTION OF SYMBOLS 1 ... Ultrasonic probe, 2 ... Pulse transmitter / receiver, 3 ... A / D converter, 4 ... Time gate setting part, 4a ... Calculation model, 4a1 ... Calculation model without a defect, 4a2 ... Calculation model with a defect, 4b ... Simulation image, 5 ... Video generation unit, 6 ... Display unit, 7 ... Water, 8 ... Ultrasound, 9 ... Inspection object, 10 ... Structure model structure information setting screen, 10a ... Structure information setting table, 10b ... Structure information Reference drawing, 11 ... Setting screen of physical property information of calculation model, 12 ... Reception waveform in calculation model without defect, 12a, 12b ... Reflection waveform, 13 ... Reception waveform in calculation model with defect, 13a, 13b ... Reflection Waveform, 20 ... Calculation model structure information setting screen, 20a ... Structure information setting table, 20b ... Structure information reference diagram, 21 ... Transmission ultrasound probe, 22 ... Reception ultrasound probe, 91a, 91b, 91 , 91d ... layer of silicon, 92a, 92b, 92c ... non-conductive layers of the film, 93 ... defect.

Claims (9)

An ultrasonic probe that scans the inspection object by transmitting ultrasonic waves to the inspection object;
The calculation model of the inspection object is input, the ultrasonic wave propagating through the inspection object is obtained by numerical simulation using the calculation model, and a time gate that is a time range is set based on the result of the numerical simulation A time gate setting unit configured in
Image generation configured to record the waveform of the ultrasonic wave obtained from the inspection object by scanning the ultrasonic probe and generate the inspection image of the inspection object using the waveform within the time gate And comprising
The time gate setting unit, as the calculation model, is input a calculation model without a defect in which the defect to be inspected is not set and a calculation model with a defect in which the defect is set, and the calculation model without the defect Obtaining the ultrasonic wave propagating through the inspection object for each of the calculation models with defects by the numerical simulation,
The time gate is at least a part of a time range in which the waveform of the ultrasonic wave determined by the calculation model without defects and the waveform of the ultrasonic wave determined by the calculation model with defects are different from each other. is there,
An ultrasonic imaging apparatus characterized by that. The time gate setting unit calculates a difference in amplitude between the waveform of the ultrasonic wave for the calculation model without the defect and the waveform of the ultrasonic wave for the calculation model with the defect, which is obtained by the numerical simulation, The time gate is at least part of a time range in which the difference is greater than a predetermined threshold;
The ultrasonic imaging apparatus according to claim 1. The ultrasonic probe transmits the ultrasonic wave to the inspection target and receives a reflected wave from the inspection target;
The time gate setting unit obtains the reflected wave by the numerical simulation,
The video generation unit records the waveform of the reflected wave, generates the inspection video of the inspection target using the waveform of the reflected wave within the time gate,
The time gate is at least part of a time range in which the waveform of the reflected wave obtained by the calculation model without defects and the waveform of the reflected wave obtained by the calculation model with defects are different from each other. is there,
The ultrasonic imaging apparatus according to claim 1 or 2. Further comprising a receiving ultrasonic probe for receiving a transmitted wave that has passed through the inspection object;
The time gate setting unit obtains the transmitted wave by the numerical simulation,
The image generation unit records the waveform of the transmitted wave, generates the inspection image of the inspection object using the waveform of the transmitted wave within the time gate,
The time gate includes at least a part of a time range in which the waveform of the transmitted wave obtained by the calculation model without defects and the waveform of the transmitted wave obtained by the calculation model with defects are different from each other. is there,
The ultrasonic imaging apparatus according to claim 1 or 2. A first step of inputting, into the ultrasound imaging apparatus, a computation model to be inspected by which ultrasound is transmitted and an inspection image is generated;
A second step in which the ultrasonic imaging apparatus obtains the ultrasonic wave propagating through the inspection object using the calculation model by numerical simulation;
A third step of setting a time gate that is a time range in the ultrasonic imaging device based on the result of the numerical simulation;
The ultrasound imaging apparatus records the waveform of the ultrasound obtained from the inspection object by scanning the inspection object with an ultrasonic probe that transmits the ultrasonic wave to the inspection object, and within the time gate A fourth step of generating the inspection image of the inspection object using the waveform,
In the first step, a calculation model without a defect in which the defect to be inspected is not set and a calculation model with a defect in which the defect is set are input as the calculation model,
In the second step, the ultrasonic wave propagating through the inspection object for each of the calculation model without defects and the calculation model with defects is obtained by the numerical simulation,
In the third step, at least a part of a time range in which the waveform of the ultrasonic wave determined by the calculation model without defects and the waveform of the ultrasonic wave determined by the calculation model with defects are different from each other. Is the time gate,
An ultrasonic image generation method characterized by the above. In the third step, the ultrasonic imaging apparatus obtains the ultrasonic waveform for the calculation model without defects and the ultrasonic waveform for the calculation model with defects obtained by the numerical simulation. Calculating an amplitude difference, and setting the time gate as at least a part of a time range in which the difference is greater than a predetermined threshold;
The ultrasonic image generation method according to claim 5. In the third step, the ultrasonic waveform for the calculation model without defects and the ultrasonic waveform for the calculation model with defects obtained by the numerical simulation by the operator of the ultrasonic imaging apparatus And at least a part of a time range in which and are different from each other,
The ultrasonic image generation method according to claim 5. The ultrasonic probe transmits the ultrasonic wave to the inspection target and receives a reflected wave from the inspection target;
In the second step, the ultrasound imaging apparatus obtains the reflected wave by the numerical simulation,
In the third step, at least one of time ranges in which a waveform of the reflected wave obtained by the calculation model without defects and a waveform of the reflected wave obtained by the calculation model with defects are different from each other. Part as the time gate,
In the fourth step, the ultrasound imaging apparatus records the waveform of the reflected wave, and generates the inspection image of the inspection object using the waveform of the reflected wave within the time gate.
The ultrasonic image generation method according to claim 5. A transmitted ultrasonic wave transmitted through the inspection object is received by a receiving ultrasonic probe,
In the second step, the ultrasound imaging apparatus obtains the transmitted wave by the numerical simulation,
In the third step, at least one of time ranges in which the waveform of the transmitted wave obtained by the calculation model without defects and the waveform of the transmitted wave obtained by the calculation model with defects are different from each other. Part as the time gate,
In the fourth step, the ultrasonic imaging apparatus records the waveform of the transmitted wave, and generates the inspection image of the inspection object using the waveform of the transmitted wave within the time gate.
The ultrasonic image generation method according to claim 5.

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