JP4700015B2 - Ultrasonic inspection method and ultrasonic inspection apparatus - Google Patents

Description

  The present invention relates to an ultrasonic inspection method and an ultrasonic inspection apparatus, and more particularly to an ultrasonic inspection method suitable for application to an ultrasonic inspection of an inspection object that is a multilayer structure such as a multilayer semiconductor and a multilayer IC. And an ultrasonic inspection apparatus.

  For ultrasonic inspection of fine structures such as semiconductors and ICs that check for internal delamination and voids, a conventional two-dimensional mechanical scanning method using a single-focus ultrasonic sensor with a scanner or the like is practical. It has become. This method uses a single-focus ultrasonic sensor to focus on the inspection target site in the structure, which is the inspection target, to transmit and receive ultrasonic waves, and to gate the reflected wave from the inspection target region. Thus, the intensity of the reflected wave is obtained. Inspection image information is created by mechanically two-dimensionally scanning a single-focus ultrasonic sensor and mapping the obtained reflected wave information in a two-dimensional space. Based on this inspection image information, the presence or absence of a defect is examined (for example, refer to Patent Documents 1 and 2).

  However, in the inspection method that mechanically scans the single focus ultrasonic sensor described above, the ultrasonic beam diameter and the mechanical scanning feed width (pitch) determine the spatial resolution of the inspection image. For this reason, in order to detect small defects, it is necessary to make the scanning pitch fine. However, when the scanning pitch is made fine, it takes time to mechanically scan the single focus type ultrasonic sensor, resulting in a problem that the inspection time becomes long. In order to solve this problem, an inspection method using an array type ultrasonic sensor has been devised.

  An array-type ultrasonic sensor arranges a plurality of piezoelectric vibration elements in a line, and transmits and receives ultrasonic waves by giving a time delay of element driving to a part of the ultrasonic vibration elements, thereby transmitting ultrasonic waves transmitted to a site to be inspected. It can be focused and focused. Also, by placing lenses in the normal direction of the array of piezoelectric vibration elements (array direction), or by arranging the array of piezoelectric vibration elements on a curved surface, one point as with the single focus ultrasonic sensor Ultrasound can be transmitted and received so as to focus. In addition, it is faster than mechanical scanning by focusing with an array type ultrasonic sensor and electronically switching and electronically scanning some piezoelectric transducers used for transmitting and receiving ultrasonic waves in the array direction. Ultrasonic inspection has become possible (see, for example, Patent Documents 3 and 4). As an inspection method using an array type ultrasonic sensor, there are respective ultrasonic inspection methods called a reflection method and a transmission method. The reflection method receives a reflected wave generated by reflection of an ultrasonic wave transmitted from an array-type ultrasonic sensor by a defect inside an inspection object, and creates inspection image information based on the intensity of the reflected wave (Patent Document 3). reference). In the transmission method, for example, two array type ultrasonic sensors are arranged so as to sandwich an inspection object having a large attenuation of ultrasonic waves, and the ultrasonic wave transmitted from one array type ultrasonic sensor and transmitted through the inspection object. Is received by the other array-type ultrasonic sensor, and inspection image information is created (see Patent Document 4).

  Patent Document 5 also describes ultrasonic inspection using a transmission method. Before carrying out the transmission method, the upper ultrasonic sensor is focused on the defect in the inspection object by the reflection method, and the height of the upper ultrasonic sensor is determined. Thereafter, the wiring to the receiver is connected to the ultrasonic sensor below, and the transmission method is performed.

JP-A-5-232092 JP-A-7-244030 Japanese Patent Laid-Open No. 11-304769 JP 2003-262620 A Japanese Patent No. 3822500

  In recent years, with the spread of small electronic devices such as mobile phones and digital cameras, the integration of integrated circuits (ICs) is rapidly progressing. In the past, high integration of ICs was mostly due to the miniaturization technology of the manufacturing process. However, these small electronic devices have been remarkably improved in functionality, multifunction and performance in recent years, and further high-density mounting technology has become necessary. For this reason, semiconductor manufacturers have developed multilayer semiconductors in which IC chips (layer structures) are arranged in layers in order to further improve the mounting density, and have put the multilayer semiconductors into practical use. However, since a multilayer semiconductor has a miniaturized process and has a laminated structure, ensuring its reliability is a major issue. In order to ensure this reliability, it is necessary to develop technology for inspecting multilayer semiconductors.

  In conventional single-layer semiconductors, reflection-type ultrasonic inspection has been used for defect inspection such as peeling of the joint (Patent Documents 1 to 3). However, when the ultrasonic inspection by the reflection method is applied to the multilayer semiconductor, it is difficult to detect the reflected wave of the lower layer in the lower layer ultrasonic inspection of the plurality of layers due to the influence of the reflected wave generated in each upper layer. There was a problem. For this reason, the inventors arrange two ultrasonic sensors so as to sandwich the multilayer semiconductor, and perform ultrasonic inspection of the multilayer semiconductor by a transmission method that is not affected by the reflected wave on the upper layer. It is considered to do. However, in the conventional transmission method, since the inspection is performed based on only information on whether or not the ultrasonic wave has passed through the inspection object, it cannot be specified which layer of the multilayer structure has the defect.

  An object of the present invention is to provide an ultrasonic inspection method and an ultrasonic inspection apparatus that can confirm in a shorter time that a defect does not exist, and can accurately find a layer structure in which a defect exists when a defect exists. It is to provide.

  A feature of the present invention that achieves the above-described object is that ultrasonic waves are emitted from one of the first array type ultrasonic sensor and the second array type ultrasonic sensor to an inspection object having a plurality of layer structures. The first ultrasonic wave transmitted and received by the other ultrasonic sensor of the first array type ultrasonic sensor and the second array type ultrasonic sensor is output and transmitted from the other ultrasonic sensor. First image information is created based on the received signal, and when a defect in the inspection object is found based on the first image information, transmission of an ultrasonic wave to the inspection object and a reflection reflected from the inspection object It is to perform reception of sound waves by the same ultrasonic sensor and create second image information based on a second reception signal output from the ultrasonic sensor.

  The ultrasonic wave transmitted from one ultrasonic sensor to the inspection object and transmitted through the inspection object is received by the other ultrasonic sensor, and the first image is based on the first reception signal output from the other ultrasonic sensor. Since the information is created, it can be confirmed in a shorter time that there is no defect when the inspection object having a plurality of layer structures has no defect. When a defect is found in the inspection object by the first image information, transmission of ultrasonic waves to the inspection object and reception of ultrasonic waves reflected from the inspection object are performed by the same ultrasonic sensor. Since the second image information is created based on the second reception signal output from the ultrasonic sensor, it is possible to accurately find the layer structure in which the defect exists.

  ADVANTAGE OF THE INVENTION According to this invention, it can confirm in a short time that a defect does not exist in the test target object which has a multilayered structure of multiple layers. Further, it is possible to accurately find a layer structure in which a defect exists in an inspection object in which a defect exists.

  Examples of the present invention will be described below.

  An ultrasonic inspection method according to a preferred embodiment of the present invention will be described below with reference to FIGS. First, an ultrasonic inspection apparatus 1 used in this ultrasonic inspection method will be described with reference to FIG. The ultrasonic inspection apparatus 1 includes a flaw detection apparatus 2, a transmission / reception apparatus 16, and a control apparatus 26.

  The flaw detection apparatus 1 includes array type ultrasonic sensors (hereinafter simply referred to as ultrasonic sensors) 2A and 2B and a scanning device 4. The ultrasonic sensor 2A has a plurality of piezoelectric vibration elements 3A, and the ultrasonic sensor 2B has a plurality of piezoelectric vibration elements 3B. The number of piezoelectric vibration elements 3A is the same as that of the piezoelectric vibration elements 3B. The ultrasonic sensor 2A is located above the ultrasonic sensor 2B. The scanning device 4 includes a support member 5, a Y-direction moving device 6, Z-direction moving devices 7 and 8, and an X-direction moving device 9 that are installed on the floor surface. The Y-direction moving device 6 is attached to the support member 5 so as to be movable in the Y direction. The Z-direction moving devices 7 and 8 are attached to the Y-direction moving device 6 so as to be movable in the Z direction (up and down direction). The ultrasonic sensor 2A is attached to the Z-direction moving device 8. The ultrasonic sensor 2 </ b> B is attached to the Z-direction moving device 7. The ultrasonic sensor 2A and the ultrasonic sensor 2B are disposed so that the piezoelectric vibration element 3A and the piezoelectric vibration element 3B face each other. Although not shown, the X-direction moving device 9 is attached to the support member 5 so as to be movable in the X direction. The X direction is one direction orthogonal to the Z direction and extending in the horizontal direction. The Y direction is orthogonal to the Z direction and is orthogonal to the X direction in the horizontal direction. A support member 10 extending in the horizontal direction is attached to the X-direction moving device 9 so as to be movable in the Z direction. The multilayer semiconductor 11 that is the inspection object is attached to the support member 10.

  The support member 5 of the scanning device 4 is attached to and supported by a column (not shown) disposed outside the water tank 14. The water tank 14 is filled with water 15. The multilayer semiconductor 11, which is an inspection object attached to the ultrasonic sensors 2 </ b> A and 2 </ b> B and the support member 10, is disposed in the water tank 14 and immersed in the water 15.

  The transmission / reception device 16 includes a pulser 17 and a receiver 21. The pulser 17 includes a transmission delay circuit 18, a transmission switching circuit 19, and a transmission amplifier 20. Although the transmission delay circuit 18 is not illustrated, the same number as the number of the piezoelectric vibration elements 3A exists. The transmission switching circuit 19 uses a multiplexer (or a crosspoint switch) having the first switching circuit of that number. Although not shown, there are as many transmission amplifiers 20 as the total number of the piezoelectric vibration elements 3A and 3B. One transmission delay circuit 18 is connected to one terminal of one first switching circuit of the transmission switching circuit 19. The other two terminals of the first switching circuit are separately connected to the two transmission amplifiers 20. The transmission delay circuit 18, the first switching circuit, and the first connection body of the transmission amplifier 20 connected in this way are provided by the number of piezoelectric vibration elements 3 </ b> A. In each of these first connection bodies, one of the two transmission amplifiers 20 is connected to one piezoelectric vibration element 3A and the other is connected to one piezoelectric vibration element 3B. In each first connection body, the first switching circuit switches any one of the transmission delay circuit 18 and the piezoelectric vibration element 3A and the transmission delay circuit 18 and the piezoelectric vibration element 3B via the corresponding transmission amplifier 20 by switching operation. Realize the connection state.

  The receiver 21 includes a reception switching circuit 25, a reception amplifier 24, an analog / digital converter (A / D converter) 23, and a delay memory 22. The reception switching circuit 25 uses a multiplexer (or a cross point switch) having a plurality of second switching circuits. Although not shown, the second switching circuit of the reception switching circuit 25, the reception amplifier 24, the A / D converter 23, and the delay memory 22 also have the same number as the number of piezoelectric vibration elements 3A. The above-mentioned number of second connection bodies configured by connecting one second switching circuit, one reception amplifier 24, one A / D converter 23, and one delay memory 22 in this order are provided. . In each of these second connection bodies, one terminal of the second switching circuit is connected to the piezoelectric vibration element 3A, and the other one terminal of the second switching circuit is connected to the piezoelectric vibration element 3B. In each second connection body, the second switching circuit realizes a connection state between the piezoelectric vibration element 3A and the reception amplifier 24 and the piezoelectric vibration element 3B and the reception amplifier 24 by a switching operation.

  By configuring the connection bodies in the pulsar 17 and the receiver 21 as described above, the transmission delay circuit 18 in the pulsar 17, the reception amplifier 24 in the receiver 21, the A / D converter 23, and the delay memory 22 are provided. The piezoelectric vibration elements 3A and 3B can be shared.

  The computer 27 includes a controller 28, a signal processing device 20, and a storage device 30. The signal processing device 29 also functions as an image information creation device. The control device 26 includes a controller 28, a scan controller 31, a switching controller 32, a delay controller 33, and an adder circuit 34. The controller 28 is connected to the scanning controller 31, the switching controller 32, and the delay controller 33. The scanning controller 31 is connected to the X-direction body moving device 9, the Y-direction moving device 6, the Z-direction moving devices 7 and 8, and the X-direction moving device 9 of the scanning device 4, respectively. The switching controller 32 is connected to each transmission switching circuit 19 and each reception switching circuit 25. The delay controller 33 is connected to each transmission delay circuit 18 and each delay memory 22. The adder circuit 34 is connected to each delay memory 22 and further connected to the signal processing device 29. The signal processing device 29 is connected to the storage device 30 and the display device 35.

  The ultrasonic inspection method of the present embodiment using the ultrasonic inspection apparatus 1 will be described with reference to the procedure shown in FIG. 2, taking as an example the case of inspecting the multilayer semiconductor 11 that is the inspection object. The multilayer semiconductor 11 has, for example, a multi-layer IC chip as a multi-layer structure. Prior to performing step S <b> 1 shown in FIG. 2, the multilayer semiconductor 11 is attached to the support member 10. The operator inputs an inspection start signal to the controller 28 from an input device (not shown). The controller 28 outputs a scanning command to the scanning controller 31. The scanning controller 31 that has input the scanning command outputs the driving command to the support member driving device, the Y direction moving device 6, and the Z direction moving devices 7 and 8 provided in the X direction moving device 9. The support member driving device, the Y-direction moving device 6 and the Z-direction moving devices 7 and 8 are respectively driven, and the supporting member 10 and the ultrasonic sensors 3A and 3B are arranged at predetermined positions in the water 15 in the water tank 14. . The multilayer semiconductor 11 is disposed between the ultrasonic sensor 3A and the ultrasonic sensor 3B.

  A transmission method is performed to create inspection image information of the inspection object (step S1). Inspection of a multilayer semiconductor (hereinafter referred to as inspection object) 11 by a transmission method is performed. The case where the ultrasonic sensor 2B is used for transmission and the ultrasonic sensor 2A is used for reception will be described. The operator issues an inspection start command, a sensor designation command indicating that the ultrasonic sensor 2B is used for transmission and the ultrasonic sensor 2A is used for reception in the transmission method, and ultrasonic waves in the depth direction in the inspection object 11. The focal position information indicating the focal position (the focal point of the ultrasonic wave) is input to the controller 28 from the above input device. Further, a sensor designation command for designating an ultrasonic sensor (for example, the ultrasonic sensor 2A) to be used first in the reflection method is also input to the controller 28 from the input device. The position of the focal point (hereinafter simply referred to as the focal point) of the ultrasonic wave in the depth direction in the inspection object 11 may be determined by the operator based on the occurrence probability of defects. For example, when it is not known which layer in the inspection object 11 has a defect, the focal position may be set at the center of the inspection object 11 in the thickness direction. Further, when a defect is likely to occur in the lower layer of the inspection object 11, the focal position may be set in the assumed lower defect generation layer. The set focal position in the depth direction affects the blur of the defect image and the detection limit size of the defect due to the blur in the inspection image information created based on the reception signal by the transmission method.

  Based on the input inspection start command and sensor designation command, the controller 28 outputs an excitation signal (transmission signal) and a switching command for a plurality of continuous piezoelectric vibration elements 3B that are a part of all the piezoelectric vibration elements 3B. Output. A plurality of continuous piezoelectric vibration elements (hereinafter referred to as “partial piezoelectric vibration elements”) 3B which are a part of all the piezoelectric vibration elements 3B are, for example, an ultrasonic sensor 2B having 19 piezoelectric vibration elements 3B. In this case, there are five continuous piezoelectric vibration elements 3B. The controller 28 outputs each delay time information corresponding to a part of the piezoelectric vibrating elements 3 </ b> B obtained based on the input focal position information and the excitation signal to the delay controller 33. Further, the controller 28 outputs each switching command corresponding to the part of the piezoelectric vibrating elements 3 </ b> B to the switching controller 32.

  The switching controller 32 controls each first switching circuit connected to the above-described part of the piezoelectric vibration elements 3B among the first switching circuits included in the transmission switching circuit 19, and these piezoelectric vibration elements 3B. And the corresponding transmission delay circuit 18 are connected to each other. In addition, the switching controller 32 includes each second switching included in the reception switching circuit 25 to which the same number of piezoelectric vibrating elements (a part of the piezoelectric vibrating elements) 3A facing the piezoelectric vibrating elements 3B are connected. Control the circuit. These second switching circuits connect the piezoelectric transducer elements 3 </ b> A and the corresponding receiving amplifiers 24 under the control of the second switching circuits.

  Each transmission delay circuit 18 to which the excitation signal and the delay time information are input from the delay controller 33 outputs the excitation signal delayed based on the input delay time information. This excitation signal is input to each transmission amplifier 20 via the corresponding first switching circuit. The excitation signals amplified by these transmission amplifiers 20 are input to some piezoelectric vibration elements 3B, for example, five piezoelectric vibration elements 3B indicated by diagonal lines in FIG. These piezoelectric vibration elements 3B are excited to vibrate and transmit ultrasonic waves. The ultrasonic wave transmitted from each piezoelectric vibration element 3B reaches the inspection object 11 from the lower surface of the inspection object 11, and is focused on the focal point 12 at the position specified by the focal position information.

  The switching controller 32 switches each first switching circuit to which some of the piezoelectric vibration elements 3B are connected individually or all at the same time. Thereby, an excitation signal can be transmitted individually or all to each of some of the piezoelectric vibrating elements 3B. Since a switch such as a multiplexer is used for the transmission switching circuit 19 and the reception switching circuit 25, the ultrasonic sensor 2B is determined by determining the number of the piezoelectric vibration elements 3B and the piezoelectric vibration elements 3B at the extreme ends that transmit ultrasonic waves. Among the 1 to N piezoelectric vibration elements 3 </ b> B included, the number of the series of piezoelectric vibration elements 3 </ b> B is selected as the partial piezoelectric vibration elements 3 </ b> B described above. Also, 1 to N piezoelectric elements included in the ultrasonic sensor 2A are determined by determining the number of the piezoelectric vibration element 3A and the piezoelectric vibration element 3A at the extreme end facing and receiving the piezoelectric vibration element 3B at the extreme end. The number of piezoelectric vibration elements 3A of the number among the vibration elements 3A is selected as a part of the piezoelectric vibration elements 3A.

  As described above, when each excitation signal to which a delay time is given is transmitted to some selected piezoelectric vibration elements, each piezoelectric vibration element transmits ultrasonic waves with a time delay corresponding to the delay time. When focusing each ultrasonic wave, the delay time corresponding to the geometric distance from each piezoelectric vibration element to the focusing position, that is, the distance considering the sound velocity of the ultrasonic wave in each medium and refraction at the boundary surface Thus, a voltage may be applied to each piezoelectric guiding element. In general, when the object to be inspected is composed of a plurality of materials, the angle of refraction between each medium is obtained using Snell's law expressed by equation (1), and the geometrical distance to the focal point is determined. A propagation path is calculated to determine a delay time for each piezoelectric vibration element.

Here, θ is the incident angle and refraction angle of the ultrasonic wave, v is the sound velocity of the ultrasonic wave, and the subscripts 1 and 2 are the medium numbers. Using the delay time determined in this way, the ultrasonic wave is focused on a predetermined position (focal point 12) of the inspection object 11.

  The ultrasonic wave transmitted into the inspection object 11 passes through the inspection object 11 and is received by the above-described part of the piezoelectric vibration elements 3A, for example, the five piezoelectric vibration elements 3A described above. These piezoelectric vibration elements 3A output the respective reception signals to the respective reception amplifiers 24 via the corresponding second switching circuits. The switching controller 32 switches each second switching circuit to which a part of the piezoelectric vibrating elements 3A are connected individually or all at the same time. Thereby, it is possible to transmit the respective reception signals from some of the piezoelectric vibration elements 3A to the corresponding reception amplifiers 24 individually or all at the same time.

  The ultrasonic waves transmitted from a part of the piezoelectric vibration elements 3B of the ultrasonic sensor 2B are received by a part of the piezoelectric vibration elements 3A of the ultrasonic sensor 2A at a line-symmetric position. However, the inspection object 11, the ultrasonic sensor 2B, and the ultrasonic sensor 101C are all arranged in parallel. It is essential that the ultrasonic sensors 2A and 2B are arranged in parallel to each other. However, when the inspection object 11 is tilted, the ultrasonic wave is received from the geometric propagation path of the ultrasonic wave calculated by (Equation 1), not the piezoelectric vibrating element at the line-symmetrical position. The reception switching circuit 25 may select an optimum piezoelectric vibration element for the above.

  The reception signal which is an analog signal is amplified by the reception amplifier 24 and converted into a digital signal by the A / D converter 23. The received signal converted into the digital signal is stored in the corresponding delay memory 22. Each delay memory 22 gives each delay time information output from the delay controller 33 to each received signal from each piezoelectric vibrating element 3A when receiving the ultrasonic wave focused on the focal point 13, and these The received signal is stored. Each received signal, which is a digital signal to which delay time information is added, is output from each delay memory 22 to the adder circuit 34. The adder circuit 34 adds the respective digital signals to which the delay time information is added, which are the respective reception signals from some of the rolling vibration elements 3A described above. That is, the adder circuit 34 adds the digital signals whose time axes are corrected based on the given delay time information, and outputs the result to the signal processing device 29. The signal processing device 29 stores the added digital signal information (including the received ultrasonic waveform information and intensity information) in the storage device 30.

  The ultrasonic transmission from some of the piezoelectric vibration elements 3B and the reception of the ultrasonic waves by the corresponding part of the piezoelectric vibration elements 3A described above are performed for all the piezoelectric vibration elements 3B and the ultrasonic sensors in the ultrasonic sensor 2B. For all the piezoelectric vibration elements 3 </ b> A in 2 </ b> A, each part of the piezoelectric vibration elements is electronically sequentially switched. By such electronic scanning, ultrasonic inspection in the Y direction can be performed on the inspection object 11. The inspection of the inspection object 11 in the X direction is performed by moving the X direction moving device 9 under the control of the scanning control device 31. In this embodiment, the ultrasonic waveform and intensity received through the inspection object 11 can be obtained on the two-dimensional plane in the X direction and the Y direction of the inspection object 11 by such ultrasonic inspection. it can. Information on the reception waveform and reception intensity of the ultrasonic wave in the two-dimensional plane is stored in the storage device 30 by the signal processing device 29.

  The signal processing device 34 creates inspection image information based on the intensity information of the transmitted reception signal stored in the storage device 30. The inspection image information created based on the intensity information of the transmitted reception signal is referred to as transmission image information. When the ultrasonic wave transmitted from the piezoelectric vibration element 3 </ b> B transmits through the inspection object 11 and propagates, the ultrasonic wave travels while repeating transmission and reflection at the joint in the inspection object (multilayer semiconductor) 11. Here, the energy transmission factor of the ultrasonic wave can be expressed by equation (2).

Here, T is the ultrasonic energy transmittance, z is the acoustic impedance (the product of the sound speed and density of the medium), and the subscripts 1 and 2 indicate the medium number, and the ultrasonic energy transmittance T is the medium. Shows the ratio when transmitting from 1 to medium 2

. According to the equation (2), if the medium 1 and the medium 2 are continuous, that is, in a joined state, the ultrasonic wave is transmitted at a constant rate. Conversely, when the medium 1 and the medium 2 are not joined, z ₂ since the acoustic impedance of air, a very small value as compared with the solid. For this reason, the ultrasonic wave hardly penetrates the inspection object.

  Due to the above phenomenon, in the ultrasonic inspection by the transmission method for the inspection object 11, the intensity 41 of the transmitted ultrasonic wave reception signal 41 shown in FIG. can get. In the region 50 outside the inspection object 11, the ultrasonic wave transmitted from the piezoelectric vibration element 3 </ b> B only passes through the water 15 that is a medium. For this reason, the intensity 41A of the received signal in the region 50 is the largest. The intensity 41B of the received signal in the region other than the defect 13 of the inspection object 11 is smaller than the intensity 41A by the amount of the ultrasonic wave reflected internally by the inspection object 11. Since the ultrasonic wave does not pass through the inspection object 11 at the defect 13, the intensity 41C of the received signal in the area of the defect 13 becomes zero.

  The signal processing device 29 creates transmission image information 38 (see FIG. 3) by using the received intensity information in the two-dimensional plane including the received signal intensity 41 information. The transmission image information 38 is created in gray scale, for example. That is, the region where the received signal strength is the highest is white, each region where the received signal strength is gradually weakened is displayed in light gray, and the region where the received signal strength is zero is displayed in black. In the fluoroscopic image information 38 created as described above, the intensity 41A having the strongest intensity is white, the intensity 41B is gray, and the intensity 41C (defect area 39 of the transmission image information 38) has zero intensity. Since there are, it is displayed in black. In the transmission image information 38, the transmission image information 38 is not grayscale but can be displayed in an assigned color according to the received signal intensity. The display device 35 displays the transmission image information 38 including the defect area 39 output from the signal processing device 29. The operator can grasp the presence / absence of a defect in the inspection object 11 and the position and size in the two-dimensional plane when the defect 13 exists by looking at the displayed transmission image information 38.

The ultrasonic inspection by the transmission method can be performed as described above by using the ultrasonic sensor 2A for transmission and the ultrasonic sensor 2B for reception. When the smooth surface of the inspection object 11 is facing downward, the ultrasonic sensor 2B is used for transmission, and when the smooth surface of the inspection object 11 is facing upward, the ultrasonic sensor 2A is sent. It is desirable to use it as trust. When high sound waves are incident on the inspection object 11 from a smooth surface, the ultrasonic waves are easily focused in the inspection object 11, and the ultrasonic inspection of the inspection object 11 can be easily performed. However, when an ultrasonic wave is incident on the inspection object 11 from a non-smooth surface with a solder ball or the like, the wave surface of the incident ultrasonic wave is disturbed and the ultrasonic wave is not focused inside the inspection object 11.
The operator determines which of the ultrasonic sensors 2 </ b> A and 2 </ b> B is used for transmission, and is instructed by a sensor designation command input to the controller 28.

  When the operator sees the displayed transmission image information 38, if the defect exists, information “defective” is obtained, and if there is no defect, information “defective” is input from the above-mentioned input device to the controller 28. To enter. Based on this input information, the controller 28 determines the presence or absence of defects shown in FIG. 2 (step S2). When there is no defect in the inspection object 11, the ultrasonic inspection for the inspection object 11 ends. The inspection object 11 is removed from the support member 10. Thereafter, a new inspection object 11 is attached to the support member 10, and the above-described ultrasonic inspection for the inspection object 11 is performed.

  Since the transmission image information 38 indicates that the defect 13 exists, the determination in step S <b> 2 is “defect”, and the inspection object 11 is subjected to ultrasonic inspection by the reflection method. In the ultrasonic inspection by this reflection method, the processes of steps S3 to S8 shown in FIG. 2 are executed. These processes will be described in detail.

  The reflection method is performed using the ultrasonic sensor located above, and inspection image information of the inspection object is created (step S3). Based on the sensor designation command in the reflection method that is input together with the above-described inspection start command, the controller 28 includes a plurality of consecutive plural piezoelectric transducer elements 3A of the ultrasonic sensor 2A positioned above. The excitation signal and the switching command for the piezoelectric vibration element 3A (hereinafter referred to as a part of the piezoelectric vibration element) 3A are output. The part of piezoelectric vibration elements 3A is, for example, five piezoelectric vibration elements 3A. The controller 28 outputs each delay time information corresponding to a part of the piezoelectric vibrating elements 3 </ b> A and the excitation signal to the delay controller 33. The controller 28 outputs each switching command corresponding to the part of the piezoelectric vibrating elements 3 </ b> A to the switching controller 32. Each delay time information is created by the controller 28. The controller 28 uses the data on the number of layers of the layer structure in the inspection object 11 input in advance in the storage device 30 and the equation (1), and the inspection object for positioning the focus for each layer structure. The ultrasonic wave propagation path in the object 11 is calculated, and a delay time for forming a focal point for each layer is obtained. The delay time information is sequentially output from the controller 28 to the delay controller 33 for each layer structure in accordance with the processing procedure shown in FIG.

  The switching controller 32 controls each of the above-described first switching circuits connected to the part of the piezoelectric vibration elements 3 </ b> A, and connects these piezoelectric vibration elements 3 </ b> A to the corresponding transmission delay circuit 18. The switching controller 32 controls each of the above-described second switching circuits and connects the corresponding piezoelectric vibration element 3A to the corresponding reception amplifier 24.

  Each transmission delay circuit 18 that has received the delay time information focusing on the excitation signal and the first layer structure (for example, the layer structure 40 shown in FIG. 4) from the delay controller 33 receives the input delay time information. Each excitation signal delayed based on is output. These excitation signals are inputted to some of the piezoelectric vibrating elements 3A through the respective first switching circuits and the respective transmission amplifiers 20. Each ultrasonic wave transmitted from each of the piezoelectric vibration elements 3 </ b> A is focused on the first layer structure in the inspection object 11. The reflected waves reflected from the inspection object 11 are received by some of the piezoelectric vibration elements 3A. Each received signal of the reflected wave output from each of the piezoelectric vibrating elements 3A passes through the corresponding second switching circuit, each receiving amplifier 24, each A / D converter 23, and each delay memory 22. Are sequentially input and input to the adder circuit 34 in a state converted into a digital signal. Also in the reflection method, as in the transmission method, each waveform information and intensity information of the received signal in the two-dimensional plane in the X direction and Y direction of the inspection object 11 obtained by the addition circuit 34 is signal processing. It is stored in the storage device 30 by the device 29.

  The signal processing device 29 creates inspection image information based on the intensity information of the received signal of the reflected wave stored in the storage device 30. The inspection image information created based on the intensity information of the received signal of the reflected wave is referred to as reflected image information. In step S3, the focal points of the ultrasonic waves transmitted from each of the piezoelectric vibrating elements 3A are formed on the first layer structure 40 shown in FIG. In the cross section of the layer structure 40 of the first layer, the intensity 43 of the received signal of the reflected wave shown in FIG. 4 is obtained. In the region 50 outside the inspection object 11, the ultrasonic wave transmitted from the piezoelectric vibration element 3 </ b> B only passes through the water 15 as a medium and has no reflected wave, and therefore the intensity 43 </ b> A of the received signal becomes zero. . Since the defect 13 does not exist in the region of the first layer structure 40 in the inspection object 11, the strength is 43B. The intensity 43B is greater than the intensity 43A by the amount of reflection occurring on the surface of the inspection object 11 and the first layer structure 40.

  The signal processing device 29 creates the reflected image information 42 (see FIG. 4) using the received intensity information in the two-dimensional plane including the received signal intensity 43 described above. The reflected image information 42 is also created using a gray scale. The part of the intensity 43A where the intensity is zero is created in black, and the part of the intensity 43B smaller than the largest intensity is created in gray. The created reflection image information 42 is output from the signal processing device 29 to the display device 35 and displayed together with information on the number of layers (for example, the first layer) of the inspection object 11. The operator can confirm the presence or absence of a defect in the first layer.

  It is determined whether the number of layers of the next layer structure to be inspected by the reflection method is larger than the (N / 2) th layer (step S4). For example, when the number of layer structures included in the inspection object 11 is four, the second layer structure counted from the top is inspected by the reflection method using the ultrasonic sensor 2A. Inspection by the reflection method using the ultrasonic sensor 2A is not performed on the layer structure of the third layer and the fourth layer counted from the top.

  If the determination in step S4 is “NO”, the focal position is moved to the position of the next layer structure one layer below (step S5). The controller 28 outputs to the delay controller 33 delay time information for focusing on the second layer structure below the first layer.

  In step S3, the ultrasonic inspection by the reflection method using the ultrasonic sensor 2A focused on the second layer structure in the inspection object 11 is performed. That is, each transmission delay circuit 18 receives the excitation signal and the delay time information from the delay controller 33, and outputs each excitation signal delayed based on the input delay time information. Each ultrasonic wave transmitted from each of the partial piezoelectric vibrating elements 3 </ b> A to which these excitation signals are input is focused on the second layer structure in the inspection object 11. The reflected waves reflected from the second layer structure of the inspection object 11 are respectively received by a part of the piezoelectric vibration elements 3A, and reception signals are output from the part of the piezoelectric vibration elements 3A. Reflected image information is created in the same manner as when focusing on the first layer structure. This reflected image information is also displayed on the display device 35.

  Since the inspection object 11 shown in FIG. 1 includes a two-layer structure, an ultrasonic inspection by a reflection method focusing on the first layer structure from the top is performed, and the reflection image information 42 is obtained. In step S4 after the creation, the determination is “YES”.

  For this reason, a reflection method is implemented using the ultrasonic sensor located below, and inspection image information of an inspection object is created (Step S6). Based on the sensor designation command, the controller 28 outputs excitation signals and switching commands for some of the piezoelectric transducer elements 3B as described in the transmission method among all the piezoelectric transducer elements 3B of the ultrasonic sensor 2B positioned below. Output. The controller 28 outputs each delay time information corresponding to a part of the piezoelectric vibration elements 3B and the above excitation signal to the delay controller 33, and outputs each switching command corresponding to the part of the piezoelectric vibration elements 3B. Output to the switching controller 32.

  The switching controller 32 controls each of the first switching circuits connected to some of the piezoelectric vibration elements 3B described above, and connects these piezoelectric vibration elements 3B to the corresponding transmission delay circuit 18 respectively. Further, the switching controller 32 controls each of the above-described second switching circuits, and connects each corresponding piezoelectric vibration element 3 </ b> B to each corresponding receiving amplifier 24.

  Each transmission delay circuit 18 that has received the delay time information focusing on the excitation signal and the lowest layered N layer structure (the first layer from the bottom) from the delay controller 33 is based on the input delay time information. Each excitation signal delayed by the output is output. Each of the ultrasonic waves transmitted from each of the piezoelectric vibration elements 3B that have received these excitation signals is an N-th layer structure (in this embodiment, the first layer structure 44 from the bottom (FIG. 5). See))). The reflected waves reflected from the inspection object 11 are received by some of the piezoelectric vibration elements 3B. Also in step S6, as in step S3, each information of the waveform and intensity of the ultrasonic wave of the received signal on the two-dimensional plane in the X direction and Y direction of the inspection object 11 obtained by the adder circuit 34 is subjected to signal processing. It is stored in the storage device 30 by the device 29.

  The signal processing device 29 creates reflected image information based on the intensity information of the reflected wave reception signal stored in the storage device 30. The intensity 47 of the received signal of the reflected wave shown in FIG. 5 is obtained in the cross section of the first layer structure 44 from the bottom where the ultrasonic focus is formed. Since there is no reflected wave in the region 50 outside the inspection object 11, the intensity 47A of the reception signal output from the piezoelectric vibration element 3B becomes zero. Since the defect 13 exists in the cross section of the first layer structure 44 from the bottom, the intensity 47B of the received signal in the region of the inspection object 11 other than the defect 13 is caused by the ultrasonic wave generated by the inspection object 11 inside. The intensity is greater than the intensity 47A by the amount reflected. Since the ultrasonic wave is most reflected by the defect 13, the intensity 47C of the received signal in the area of the defect 13 is the highest.

  The signal processing device 29 creates the reflected image information 45 (see FIG. 5) by using the received intensity information in the two-dimensional plane including the received signal intensity 47 described above. The reflected image information 45 is also created in gray scale. The portion with the intensity 47A is made black, the portion with the intensity 47B is gray, and the portion with the intensity 47C is white. The created reflection image information 45 including the defect area 46 is output from the signal processing device 29 to the display device 35 and displayed together with information on the number of layers of the inspection object 11 (for example, the first layer from the bottom). The operator can confirm the presence or absence of defects in the second layer.

  It is determined whether the number of layers of the next layer structure to be inspected by the reflection method is smaller than the (N / 2) th layer (step S7). In the example shown in FIG. 1, the next layer structure in the first layer from the bottom is the uppermost layer structure, and therefore the determination in step S <b> 7 is “YES”. For this reason, the inspection of the reflection method using the ultrasonic sensor 2B ends. As described above, all ultrasonic inspections for the inspection object 11 by the reflection method performed after the transmission method are completed.

  If the inspection object 11 includes a four-layer structure as described above, the determination in step S7 is “NO”. In this case, the focal position is moved to the position of the next layer structure one layer below (step S8). The controller 28 outputs, to the delay controller 33, delay time information for focusing on the second layer structure from the bottom on the first layer. Returning to the process of step S6, the ultrasonic inspection by the reflection method using the ultrasonic sensor 2B focused on the second layer structure from the bottom is performed. As described above, reflection image information is created. Thereafter, when the determination in step S7 is “YES”, the inspection of the reflection method using the ultrasonic sensor 2B ends as described above.

  When the processing shown in FIG. 2 is “finished”, the signal processing device 29 displays the received ultrasonic waveform information 36 and the reflected image information 45 on the display device 35 as shown in FIG. Further, as shown in FIG. 6, the signal processing device 29 can also display the transmission image information 38 and the reflection image information 42 and 45. Thus, by displaying the transmission image information 38 and the reflection image information 42 and 45 on the display device 35 at the same time, the operator corresponds the defect area included in the transmission image information to the defect area included in the reflection image information. It is easy to determine whether or not. In particular, the reflection image information 42 obtained by the reflection method using the upper ultrasonic sensor 2 </ b> A and the reflection image information 45 obtained by the reflection method using the lower ultrasonic sensor 2 </ b> B are arranged vertically with the transmission image information 38. Is arranged. For this reason, the operator can accurately identify the defect structure and the layer structure in which the defect exists while taking correspondence between the defect area in the transmission image information and the reflection image information.

  When the transmission image information and the reflection image information are imaged with the intensity of the reception signal when the inspection image information is displayed, the color of the defective area is reversed in principle. For example, when imaged in gray scale, the defect area is displayed in black in the transmission image information, but the area is displayed in white in the reflection image information. For this reason, for example, by reversing the color information allocation with respect to the intensity of the received signal in the transmitted image information to the reflected image information, the defect area of both information can be made the same color, and the defect area in both information It becomes easy to do.

  In this embodiment, since the ultrasonic inspection by the transmission method is first performed for the inspection object 11 having a plurality of layer structures (for example, the layer structures 40 and 44) therein, the inspection object 11 It can be confirmed in a shorter time that there is no defect. For this reason, it is possible to reduce the time required for the ultrasonic inspection performed on the plurality of inspection objects 11. In this embodiment, in particular, an ultrasonic inspection by the transmission method is performed on the inspection object 11, and an ultrasonic inspection by the reflection method is performed on the inspection object 11 in which the presence of a defect is confirmed by this inspection. ing. For this reason, it is possible to reduce the time required for the ultrasonic inspection for the plurality of inspection objects 11, and furthermore, it is possible to accurately find the layer structure in the inspection object 11 where a defect exists.

  In this embodiment, as described above, it is possible to confirm the layer structure in which the defect exists and where the defect exists in the layer structure. Thereby, the manufacturing process of the multilayer semiconductor 11 which is the inspection object in which the defect exists, specifically, the manufacturing process of the layer structure in which the defect exists, and further the manufacture of the portion in which the defect of the layer structure exists. It is possible to easily check whether there is no abnormality in the process. If there is an abnormality in the corresponding part of the manufacturing process, the corresponding part of the manufacturing apparatus being used can be repaired, and a defect can be prevented from occurring in the multilayer semiconductor 11 manufactured thereafter. . In this embodiment, since the ultrasonic inspection by the reflection method performed after the transmission method is sequentially focused on all the layer structures in the inspection object 11, a plurality of defects exist. The layer structure can be detected with high accuracy. For this reason, the cause of each abnormality of the manufacturing process of these layer structures can be removed easily.

In the present embodiment, in the ultrasonic inspection by the reflection method, the ultrasonic wave can be transmitted to the inspection object 11 using one ultrasonic sensor (for example, the ultrasonic sensor 2A), and the ultrasonic wave by the one ultrasonic sensor is used. After the ultrasonic inspection is finished, ultrasonic waves can be transmitted to the inspection object 11 using the other ultrasonic sensor (for example, the ultrasonic sensor 2B). For this reason, the present embodiment can reduce the attenuation of the reflected wave, and can significantly reduce the influence of noise superposition. Thereby, the accuracy of the obtained reflected image information is improved, and the reflected image becomes clearer. The reason why the attenuation of the reflected wave and the effect of noise superposition can be reduced will be described below. In the ultrasonic inspection by the reflection method, reflection and transmission are repeated as many times as the number of layer structures that pass from when the transmitted ultrasonic wave is reflected by the defect to reach the piezoelectric vibration element of the ultrasonic sensor. In the ultrasonic inspection by the reflection method using one ultrasonic sensor, since reflection and transmission are repeated by the total number of layers of the layer structure provided on the inspection object 11, the received signal intensity of the ultrasonic wave Is significantly attenuated. In addition, when the number of layer structures through which ultrasonic waves pass is large, the reflected wave from the layer structure that has already passed through remains and is superimposed as a noise component at the same time position as the inspection target layer. That is, in the inspection object 11, the multiple reflected waves from the upper layer structure and the reflected waves from the lower layer structure are superimposed. In the inspection object 11 having a multi-layer structure, multiple reflections of ultrasonic waves occur, and therefore, multiple reflection waves from the upper layer structure are superimposed on the lower layer structure. Therefore, the lower layer structure is more difficult to be subjected to ultrasonic inspection.
. However, in this embodiment, two ultrasonic sensors are used, one ultrasonic sensor performs ultrasonic inspection from above the inspection object, and the other ultrasonic sensor performs inspection from below the inspection object. The number of layers in which ultrasonic waves from one ultrasonic sensor repeat reflection and transmission is reduced. Therefore, in this embodiment, each of the influence of the attenuation of the received signal strength and the noise superposition is reduced.

  When a defect area 39 having the same position and the same size as the defect area 39 included in the transmission image information 38 is present in the reflected image information obtained by focusing on a certain layer structure, the ultrasonic inspection is performed with the focus on. Even if there is a non-existing layer structure, the ultrasonic inspection by the reflection method can be finished. Thereby, the time of the ultrasonic inspection with respect to the test object 11 can further be shortened.

  An ultrasonic inspection method according to another embodiment of the present invention will be described below with reference to FIG. An ultrasonic inspection apparatus 1A used in the ultrasonic inspection method of the present embodiment will be described with reference to FIG. The ultrasonic inspection apparatus 1A includes a flaw detection apparatus 2, transmission / reception apparatuses 16A and 16B, a control apparatus 26, and a display apparatus 35. The configurations of the flaw detection apparatus 2 and the control apparatus 26 are the same as those of the ultrasonic inspection apparatus 1 of the first embodiment. The ultrasonic inspection apparatus 1A has a configuration in which the transmission / reception apparatus 16 of the ultrasonic inspection apparatus 1 is replaced with transmission / reception apparatuses 16A and 16B. The transmission / reception device 16A is a device dedicated to the ultrasonic sensor 2A, and the transmission / reception device 16B is a device dedicated to the ultrasonic sensor 2B.

  The transmission / reception device 16A includes a pulser 17A and a receiver 21A. The pulser 17A includes a transmission delay circuit 18A, a transmission switching circuit 19A, and a transmission amplifier 20A. The transmission switching circuit 19A uses a multiplexer (or a crosspoint switch) having a plurality of first switching circuits. The receiver 21A includes a reception switching circuit 25A, a reception amplifier 24A, an A / D converter 23A, and a delay memory 22A. The reception switching circuit 25A uses a multiplexer (or a crosspoint switch) having a plurality of second switching circuits.

  The transmission / reception device 16B includes a pulser 17B and a receiver 21B. The pulser 17B includes a transmission delay circuit 18B, a transmission switching circuit 19B, and a transmission amplifier 20B. The transmission switching circuit 19B uses a multiplexer (or crosspoint switch) having a plurality of first switching circuits. The receiver 21B includes a reception switching circuit 25B, a reception amplifier 24B, an A / D converter 23B, and a delay memory 22B. The reception switching circuit 25B uses a multiplexer (or a crosspoint switch) having a plurality of second switching circuits.

  The connection state of each component included in each of the pulsars 16A and 16B is the same as the connection state of each component included in the pulsar 16 in the first embodiment. The connection state of each component included in each of the receivers 17A and 17B is the same as the connection state of each component included in the receiver 17 in the first embodiment. The transmission delay circuit 18A, the first switching circuit of the transmission switching circuit 19A, the transmission amplifier 20A, the second switching circuit of the reception switching circuit 25A, the reception amplifier 24A, the A / D converter 23A, and the delay memory 22A include the piezoelectric vibration element 3B. There are the same number. The transmission delay circuit 18B, the first switching circuit of the transmission switching circuit 19B, the transmission amplifier 20B, the second switching circuit of the reception switching circuit 25B, the reception amplifier 24B, the A / D converter 23B, and the delay memory 22B include the piezoelectric vibration element 3B. The same number is provided.

  The switching controller 32 controls the first switching circuits included in the transmission switching circuits 19A and 19B in the same manner as the first switching circuit in the first embodiment. The switching controller 32 controls the second switching circuits included in the reception switching circuits 25A and 25B in the same manner as the second switching circuit in the first embodiment. The delay controller 33 outputs the excitation signal and the delay time information to each transmission delay circuit 18A and each transmission delay circuit 18B. The adder circuit 34 inputs the respective digital signals to which the delay time information is given from each delay memory 22A and each delay memory 22B.

  Each second switching circuit of each transmission amplifier 20A and reception switching circuit 25A is connected to each piezoelectric vibration element 3B one by one. Each second switching circuit of each transmission amplifier 20B and reception switching circuit 25B is also connected to each piezoelectric vibration element 3A one by one.

  The ultrasonic inspection method of the present embodiment using the ultrasonic inspection apparatus 1A also executes each procedure shown in FIG. The ultrasonic inspection method of the present embodiment is different from the ultrasonic inspection method of the first embodiment in that a pulser 16A is used when ultrasonic waves are transmitted from the piezoelectric vibration element 3B, and the received signal processing of the piezoelectric vibration element 3B is performed. For this, a receiver 21A is used. Further, when transmitting ultrasonic waves from the piezoelectric vibration element 3A, the pulsar 16B is used, and the receiver 21B is used for processing the reception signal of the piezoelectric vibration element 3A.

  Also in this embodiment, the effect produced in the first embodiment can be obtained. However, since the transmission / reception devices 16A and 16B are provided in this embodiment, the transmission / reception device is larger than that in the first embodiment.

It is a block diagram of the ultrasonic inspection apparatus of Example 1 which is one suitable Example of this invention. It is a flowchart which shows the procedure of the ultrasonic inspection method which is a suitable Example of this invention implemented using the ultrasonic inspection apparatus shown in FIG. It is explanatory drawing which shows the received signal intensity | strength of the transmitted ultrasonic wave obtained with the ultrasonic inspection apparatus shown in FIG. 1, and the produced transmission image information. It is explanatory drawing which shows the received signal intensity | strength of the reflected ultrasonic wave obtained with the ultrasonic sensor above the ultrasonic inspection apparatus shown in FIG. 1, and the produced reflected image information. It is explanatory drawing which shows the received signal intensity | strength of the reflected ultrasonic wave obtained with the ultrasonic sensor of the downward direction of the ultrasonic inspection apparatus shown in FIG. 1, and the produced reflected image information. It is explanatory drawing which shows an example of the display information displayed on the display apparatus of the ultrasonic inspection apparatus shown in FIG. It is a block diagram of the ultrasonic inspection apparatus of Example 2 which is another Example of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,1A ... Ultrasonic inspection apparatus, 2 ... Flaw detection apparatus, 2A, 2B ... Array type ultrasonic sensor, 3A, 3B ... Piezoelectric vibration element, 4 ... Scanning device, 6 ... Y direction moving device, 7, 8 ... Z direction Moving device, 9 ... X-direction moving device, 10 ... Support member, 11 ... Inspection object, 12 ... Focus, 13 ... Defect, 16, 16A, 16B ... Transmitting / receiving device, 17, 17A, 17B ... Pulser, 18, 18A , 18B ... transmission delay circuit, 19, 19A, 19B ... transmission switching circuit, 21, 21A, 21B ... receiver, 22, 22A, 22B ... delay memory, 25, 25A, 25B ... reception switching circuit, 26 ... control device, 28 , A controller, 29, a signal processing device, 31, a scanning controller, 32, a switching controller, 33, a delay controller.

Claims (8)

  The first array type ultrasonic sensor and the second array type ultrasonic sensor are arranged to face each other across the inspection object having a plurality of layer structures, and the first array type ultrasonic sensor and the second array type An ultrasonic wave is transmitted from one of the ultrasonic sensors to the inspection object, and the ultrasonic wave transmitted through the inspection object is used as the second array type ultrasonic sensor and the second array type ultrasonic wave. First image information is generated based on a first reception signal received by the other ultrasonic sensor of the sensors and output from the other ultrasonic sensor, and the inspection object is based on the first image information. When an internal defect is found, transmission of ultrasonic waves to the inspection object and reception of the ultrasonic waves reflected from the inspection object are performed by the same ultrasonic sensor and output from the ultrasonic sensor. 2nd receiving Ultrasonic inspection method characterized by creating a second image information based on the signal.   The ultrasonic waves transmitted from the plurality of transducers of the same ultrasonic sensor are focused on the layer structure, the reflected ultrasonic waves are received by the plurality of transducers, and the second waves are received from the respective transducers. The ultrasonic inspection method according to claim 1, wherein a reception signal is output.   The ultrasonic inspection method according to claim 1, wherein the first image information and the second image information are displayed on a display device.   The same ultrasonic sensor transmits the ultrasonic wave to the inspection object and receives the ultrasonic wave reflected from the inspection object, and to the inspection object The second array-type ultrasonic sensor that transmits the ultrasonic wave and receives the ultrasonic wave reflected from the inspection object, and outputs the second received signal output from the first array-type ultrasonic sensor. First reflection image information that is the second image information is created based on the second reception signal that is output from the second array-type ultrasonic sensor, and second reflection image information that is the second image information. The ultrasonic inspection method according to claim 1, wherein: The ultrasonic waves transmitted from the plurality of first transducers of the first array type ultrasonic sensor are focused on the layer structure, and the reflected ultrasonic waves are received by the plurality of first transducers. Outputting the second received signal from the first vibrator;
Focusing each ultrasonic wave transmitted from the plurality of second transducers of the second array type ultrasonic sensor on the other layer structure, and receiving the reflected ultrasonic waves by the plurality of second transducers; The ultrasonic inspection method according to claim 4, wherein the second reception signal is output from each second transducer.   The number of the layer structures for focusing the ultrasonic waves transmitted from the plurality of first vibrators is a predetermined number from the first vibrator side among the plurality of layer structures in the inspection object. The ultrasonic inspection method according to claim 5, wherein the number of the layer structures for focusing the respective ultrasonic waves transmitted from the plurality of second transducers is the number of the remaining layer structures in the inspection object.   The ultrasonic inspection method according to claim 4, wherein the first image information, the first reflected image information, and the second reflected image information are displayed on a display device. A first array-type ultrasonic sensor having a plurality of first transducers; a second array-type ultrasonic sensor having a plurality of second transducers;
A first switching device including a plurality of delay devices, a first connection state of the delay device and the first vibrator, and a plurality of first switching devices for switching a second connection state of the delay device and the second vibrator. And a pulser for transmitting a transmission signal to one of the first vibrator and the second vibrator connected to the delay device by a switching operation of the first switching device,
A second switching device including a plurality of delay memories, a third connection state of the delay memory and the first transducer, and a plurality of second switching devices for switching a fourth connection state of the delay memory and the second transducer. A receiver having
One of the first vibrator and the second vibrator arranged opposite to each other with an inspection object having a plurality of layer structures sandwiched therebetween is connected to the delay device so as to be connected to the delay device. Controlling the first switching device, controlling the second switching device to connect the other transducer used for reception among the first transducer and the second transducer to the delay memory;
A transmission signal received by the one transducer for transmission is output to each of the plurality of delay devices, delay time information is output to the delay device and the delay memory, and a defect exists in the inspection object In this case, one of the first vibrator and the second vibrator that transmits both the ultrasonic waves to the inspection object and receives the ultrasonic waves reflected from the inspection object. A control device for controlling the first switching device and the second switching device so as to be respectively connected to the delay device and the delay memory;
First image information is generated using first information obtained based on the first reception signal output from the other transducer for reception, and is output from the one transducer that performs transmission and reception. An ultrasonic inspection apparatus comprising: an image information creation device that creates second image information using second information obtained based on a second received signal.

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