JP4576281B2 - Ultrasonic inspection method - Google Patents

Description

  The present invention relates to an ultrasonic inspection apparatus and an ultrasonic inspection method for inspecting the inside of an inspection object nondestructively using an array type ultrasonic sensor.

  In an ultrasonic inspection apparatus using a conventional array type ultrasonic sensor, a voltage is applied as a transmission signal to each piezoelectric vibration element of the array type ultrasonic sensor in order to perform the inspection by focusing the ultrasonic wave inside the inspection target. The timing is controlled temporally. In this time control, the time for shifting the transmission signal application timing for each piezoelectric vibration element from the application timing of the transmission signal to the piezoelectric vibration element with an array type ultrasonic sensor is the delay time.

  In order to set this delay time for each piezoelectric vibration element, conventionally, the geometric distance from the point where the ultrasonic wave is desired to be focused to each piezoelectric vibration element of the array-type ultrasonic sensor is obtained, and this is determined as the inspection target. Dividing by the velocity of the ultrasonic wave depending on the material, the arrival time of the ultrasonic wave from the point where the ultrasonic wave is desired to reach to each piezoelectric vibration element of the array type ultrasonic sensor is obtained.

  The ultrasonic arrival time with reference to the element farthest to be focused, that is, the element having the longest ultrasonic arrival time, among the piezoelectric vibration elements of the array-type ultrasonic sensor used in one ultrasonic inspection. Is turned on the time axis to obtain a delay time. As a result, when the ultrasonic wave reaches the point to be focused, the ultrasonic waves transmitted from all the piezoelectric vibration elements to be used reach the focusing point in the inspection target at the same time, and the ultrasonic wave is focused. It is done.

  When the material to be inspected is one and the acoustic transmission medium is regarded as a single medium, as described above, it depends on the distance between the focusing point and each piezoelectric vibration element of the array type ultrasonic sensor and the sound speed of the medium to be inspected. Can easily set the delay time. As described above, the transmission timing, that is, the application timing is changed by changing the delay time for each piezoelectric vibration element in accordance with the focal position of the ultrasonic wave and adding the time control to the transmission signal.

  If the delay time set for each piezoelectric vibration element is changed, the focal position of the ultrasonic wave also changes. In order to change the focal position, there is known an ultrasonic inspection apparatus including a variable delay circuit in which a delay time for time control added to a transmission signal to each piezoelectric vibration element is variable by a control circuit (for example, a patent Reference 1).

  Further, as a means for focusing the ultrasonic wave in the inspection object, a technique for refracting the ultrasonic wave emitted from the piezoelectric vibration element by the acoustic lens and converging it to the focal point is not limited to the array type ultrasonic sensor. (For example, refer to Patent Document 2).

  Furthermore, by changing the position of the acoustic lens placed in the ultrasonic path between the piezoelectric vibration element and the inspection object between the piezoelectric vibration element and the inspection object, the same acoustic lens can be used within the ultrasonic inspection object. It is also known that the focal position can be changed (see, for example, Patent Document 3).

  On the other hand, when the inspection object is composed of a plurality of materials, the refraction angle in each medium can be obtained according to Snell's law expressed by Equation 1, and the ultrasonic propagation path can be calculated. .

  Here, θ is the incident angle and refraction angle of the ultrasonic wave, v is the sound velocity of the ultrasonic wave, and 1 and 2 attached to the lower right of θ and v are medium numbers.

JP 2003-130859 A Japanese Patent Application Laid-Open No. 11-211701 JP-A-10-82769

  However, in order to obtain the ultrasonic refraction angle according to Snell's law, and to obtain the geometric propagation path of the ultrasonic wave from the obtained refraction angle and the thickness of the medium, each material constituting each inspection object (each The sound velocity of the ultrasonic wave in the medium) and the dimensions of the internal structure to be inspected are essential.

  Therefore, in order to inspect a new inspection object, it is necessary to investigate or measure the speed of sound of all the materials that make up the inspection object, and to cut the cross section to investigate the internal structure of the inspection object. was there. Furthermore, in particular, when the constituent material to be inspected is made of a thin material, it is difficult to cut out the target material for investigating the sound speed, and it is difficult to evaluate the sound speed of the ultrasonic wave because of the thinness. These factors have caused a reduction in ultrasonic focusing accuracy in ultrasonic inspection.

  In particular, the inspection object is a semiconductor, and in the inspection of peeling and voids inside the semiconductor, solder balls are arranged on the back side of the semiconductor, which reflects and refracts ultrasonic waves, so there is no solder ball. The part can be inspected in the same plane inside the semiconductor, but the part directly under the solder ball cannot be inspected. Therefore, the inspection is performed by ultrasonic waves incident from the surface side of the semiconductor. However, in the field of semiconductors, the technological progress is remarkable, and every time a new material is applied, all the sound velocities of the constituent materials are individually investigated or measured, and the cross section is examined in order to investigate the internal structure to be inspected. It was necessary to cut out.

  Therefore, the present invention provides an ultrasonic inspection apparatus that uses an array type ultrasonic sensor, and suppresses a decrease in ultrasonic focusing accuracy even when the speed of sound and the detailed structure of a constituent material to be inspected are unclear. An object of the present invention is to provide an ultrasonic inspection apparatus and inspection method that can be implemented.

In the ultrasonic inspection method according to the present invention, an ultrasonic wave transmitted from an array type ultrasonic sensor and another ultrasonic sensor with the inspection target interposed therebetween and focused from the other ultrasonic sensor within the inspection target is provided. Is received by the array-type ultrasonic sensor, and the arrival time of the ultrasonic waves from the other ultrasonic sensors through the inspection target to each piezoelectric vibration element of the array-type ultrasonic sensor is measured, and based on the arrival time To obtain a delay time used for controlling the ultrasonic transmission / reception signal, based on the delay time, the transmission timing of the transmission signal applied to each piezoelectric vibration element, and the reception signal output from each piezoelectric vibration element controls reception timing based on the reception intensity of the ultrasonic wave that has reached from the other ultrasonic sensor to the piezoelectric vibrating elements of the array-probe ultrasonic sensor through said object, Select the piezoelectric vibrating element used in serial array-probe ultrasonic sensor when inspecting the inspection target, the array type from the ultrasonic sensor of the ultrasound in inspection target by transmitting and receiving ultrasonic waves to said object The inside of the inspection object can be nondestructively inspected using ultrasonic waves while suppressing the reduction of focusing accuracy.

  The ultrasonic inspection apparatus and inspection method using the array type ultrasonic sensor according to the present invention sets the optimum delay time of the array type ultrasonic sensor even when the sound speed of the material to be inspected and the detailed internal structure are not understood. An inspection can be performed.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of the present invention. First, the delay time setting method will be described with reference to FIG. The inside of the inspection object 1 has a complex structure having a multilayer structure, and several kinds of constituent materials are configured in upper and lower multilayers.

  The ultrasonic sensor 3, the array type ultrasonic sensor 4 and the inspection object 1 are in an ultrasonic transmission medium (using water or the like). The ultrasonic transmission medium is stored in the water tank 14. The ultrasonic sensor 3 and the array type ultrasonic sensor 4 are arranged in such a manner that the inspection object in the ultrasonic transmission medium is sandwiched between the ultrasonic sensor 3 from below and the array type ultrasonic sensor 4 from above. As the ultrasonic sensor 3, a focal type (also referred to as an ultrasonic focusing type) ultrasonic sensor having a function of focusing ultrasonic waves on an acoustic focus is used.

  The array ultrasonic sensor 4 has an element arrangement in which a plurality of piezoelectric vibration elements are arranged in the same direction (array direction). A transmission / reception line from the ultrasonic transmitter / receiver 6 is connected to each of the plurality of piezoelectric vibrating elements. Therefore, a plurality of piezoelectric vibration elements receive an individual transmission signal from the ultrasonic transmission / reception unit 6 and vibrate, or receive an ultrasonic wave to generate an electrical signal to individually transmit to the ultrasonic transmission / reception unit 6. A configuration that can send a received signal is adopted.

  A delay control device 7 is connected to the ultrasonic transmitter / receiver 6, and a transmission signal to each piezoelectric vibration element of the array type ultrasonic sensor 4 and a reception signal from each piezoelectric vibration element of the array type ultrasonic sensor 4. In addition, the delay control device 7 can add time control using the delay time. The delay time used for the time control has a configuration of a variable delay control device that can be varied for each piezoelectric vibration element of the array type ultrasonic sensor 4.

  The delay control device 7 is connected to a control device 8 constituted by a computer. The control device 8 controls the delay control device 7 and the ultrasonic transmitter / receiver 6 to control each operation of time control, transmission signal transmission and reception signal reception, analysis of received signals, and waveform display means. Responsible for image display processing. The control device 8 is provided with a circuit that takes in the received signal for each piezoelectric vibration element of the array-type ultrasonic sensor 4 without the time control by the delay time control device 7 between the delay time control device 7 and the circuit. In addition, it has a function of analyzing the received signal in a state in which the time control is not applied for each piezoelectric vibration element by the reception time and the reception intensity and displaying it on the waveform display means. The result of analyzing the reception time and reception intensity for each piezoelectric vibration element is, for example, as shown in FIG. 2, FIG. 3 and FIG. 4, as control data as ultrasonic reception intensity and arrival time data for each piezoelectric vibration element. 8 has a function of displaying on the storage and waveform display means 9. Further, the control device 8 sets the delay time calculated by the control device 8 in the delay control device 7 for each piezoelectric vibration element, or transmits / receives an ultrasonic wave based on the analyzed ultrasonic intensity. 6 has a function of selecting and setting each piezoelectric vibration element used for transmission and reception. In addition, the control device 8 has a function of displaying, on the waveform display means, a signal obtained by adding and synthesizing received signals subjected to time control, as in the past.

  On the other hand, the ultrasonic sensor 3 is connected to an ultrasonic transmitter / receiver 11 that transmits a transmission signal to the ultrasonic sensor 3 or receives an electric signal from the ultrasonic sensor 3 as a reception signal. The transmitter / receiver 11 is provided with waveform display means for analyzing the received signal and displaying the received waveform. The ultrasonic transmitter / receiver 11 is connected to the control device 8 and is configured such that transmission / reception is synchronized between the ultrasonic transmitter / receivers 6, 11.

  Here, the ultrasonic sensor 3 uses a focus type ultrasonic sensor. The reason is that the focal length becomes small and the ultrasonic wave spreads when the focal point is passed, so that the delay time of the array type ultrasonic sensor can be set in a wide range.

In the installation of the focus type ultrasonic sensor 3, first, ultrasonic waves are transmitted from the ultrasonic sensor 3. Next, the received signal derived from the ultrasonic wave received by the ultrasonic sensor 3 is displayed using the waveform display means 13 connected to the ultrasonic transmitter / receiver 11, and the time of the reflected wave displayed on the waveform display means 13. The ultrasonic sensor 3 is focused on the inspection target surface 2 while checking the strength.

  Next, the ultrasonic wave 12 transmitted from the ultrasonic sensor 3, focused on the inspection target surface 2, and passed through the inspection target 1 is received by each piezoelectric vibration element of the array type ultrasonic sensor 4. At this time, the time until the ultrasonic wave transmitted from the ultrasonic sensor 3 reaches each piezoelectric vibration element of the array type ultrasonic sensor 4 corresponds to the propagation path of the ultrasonic wave inside the inspection object 1. The piezoelectric vibration element directly above the ultrasonic sensor 3 is the earliest, and the outer piezoelectric vibration element is slower. However, here, the inspection object 1 has been described as having no acoustic anisotropy, but when there is an acoustic anisotropy, the piezoelectric vibrating element directly above the ultrasonic sensor 3 is the earliest, The piezoelectric vibration element is not necessarily slower, and depends on the sound speed of the ultrasonic transmission path.

  The ultrasonic waves 12 that have arrived at the piezoelectric vibration elements of the array-type ultrasonic sensor 4 from the ultrasonic sensor 3 in this way are converted into electric signals by the piezoelectric vibration elements to become reception signals, and are used as ultrasonic transmission / reception devices. 6, the time waveform or time change of the ultrasonic intensity is recorded in the control device 8 of the ultrasonic inspection apparatus for each piezoelectric vibration element, and is displayed on the waveform display means 9 of the array type ultrasonic inspection apparatus. At this time, the control device 8 of the ultrasonic inspection apparatus operates in synchronization with the ultrasonic transmitter / receiver 11 of the ultrasonic sensor 3 and the synchronization signal 10, and is installed on the inspection target surface 2 below. A point sound source is actually generated on the surface 2 to be inspected by the ultrasonic wave 12 transmitted from, and the arrival time of the ultrasonic wave 12 passing through the point sound source is received by each piezoelectric vibration element of the array type ultrasonic sensor 4. Measure from

  Next, a method for setting the delay time of each piezoelectric vibration element of the array type ultrasonic sensor 4 and a method for confirming the focal diameter thereof will be described. When the array-type ultrasonic sensor is a one-dimensional linear array sensor, the normal direction of the array direction has a curved surface structure, and this curved surface may serve as an acoustic lens. In such a case, the ultrasonic intensity when an ultrasonic wave is received by an arbitrary element of the array type ultrasonic sensor 4 is measured by changing the distance between the array type ultrasonic sensor 4 and the inspection object 1. . The result is shown in FIG.

  FIG. 2 shows that the intensity of the received ultrasonic wave becomes maximum when the acoustic focal point derived from the curved surface structure coincides with the focal point of the ultrasonic sensor 3 due to the curved surface structure in the normal direction of the array direction. Show. Therefore, the distance of the array type ultrasonic sensor 4 is set to a point where the intensity is maximum.

  Further, when the array normal direction of the array type ultrasonic sensor 4 is not a curved surface, there is no focusing effect of the ultrasonic wave due to the curved surface structure, so that the ultrasonic wave 12 from below can be received by the array type ultrasonic sensor 4. The distance from the inspection object 1 is set. When the reception time of the ultrasonic wave from the ultrasonic sensor 3 is measured at the distance of the array type ultrasonic sensor 4 set as described above, FIG. 3 is obtained. FIG. 3 shows the element number of each piezoelectric vibration element of the array-type ultrasonic sensor 4 on the horizontal axis and the arrival time of the ultrasonic wave on the vertical axis. As described above, when the inspection object 1 has no acoustic anisotropy, the ultrasonic arrival time 15 is such that the piezoelectric vibration element directly above the ultrasonic sensor 3 has the shortest ultrasonic arrival time, and is on the outside. The longer the piezoelectric vibration element is, the longer the arrival time is.

  For this reason, in the case of FIG. 3 shown here, the ultrasonic sensor 4 is installed directly under the center of the element number of each piezoelectric vibration element of the array type ultrasonic sensor. Further, the number of piezoelectric vibration elements to be selected as the driving target of the array type ultrasonic sensor used for one inspection may be arbitrarily selected according to the specification of the apparatus, as shown in FIG. A threshold value represented by a horizontal dotted line is set according to the ultrasonic wave reception intensity 16, and each piezoelectric vibration element showing an intensity exceeding the threshold value is selected, whereby the number of elements used in one inspection is determined. You may decide.

  Here, when the arrival time 15 of the ultrasonic wave 12 received by the array type ultrasonic sensor 4 in FIG. 3 is turned back with respect to the time axis (vertical axis in FIG. 4), the delay time of the array type ultrasonic sensor 4 6 is obtained. Normally, the delay time of the endmost element of each piezoelectric vibration element to be used is set to zero. Calculation of the delay time 17, selection of which piezoelectric vibration element to be driven, and addition of the delay time 17 as time control for each vibration element to be driven include the delay control device 7 and the ultrasonic transmission. It can be executed when the control device 8 issues a command to set so that the receiver 6 can perform. The set may be performed by manually operating the delay control device or the ultrasonic transceiver while viewing the waveform information on the waveform display means 9.

  The delay time 17 of the array type ultrasonic sensor 4 thus obtained is used for time control of ultrasonic transmission / reception of each piezoelectric vibration element of the array type ultrasonic sensor 4. In the case of a linear array ultrasonic sensor, electronic scanning is performed by electronically switching each piezoelectric vibration element sequentially in the array direction for the delay time of the array type ultrasonic sensor 4.

  Next, a method for confirming the focal diameter of the ultrasonic wave based on the delay time thus obtained will be described. To the ultrasonic wave 12 transmitted from the ultrasonic sensor 3, a waveform 17 is added to the array ultrasonic sensor 4 with a delay time 17, and this is electronically scanned in the array direction, and in the normal direction of the array. Is obtained by mechanically scanning the array-type ultrasonic sensor or the inspection object 1 and the ultrasonic sensor 3 to obtain the intensity distribution of the received ultrasonic wave in the plane of the inspection object surface 2 as shown in FIG. A distribution map is obtained. Using this, the focal diameter of the ultrasonic sensor 3 is measured.

  However, in order to confirm the focusing diameter, it is necessary to be a single focus type ultrasonic sensor in which the ultrasonic wave 12 transmitted from the ultrasonic sensor 3 is focused on the surface to be inspected. Must be smaller than the focal diameter of the focused sound field produced by the ultrasonic sensor 4. About the focal diameter of a sensor, when selecting an ultrasonic sensor beforehand, it should just be chosen so that the focal diameter of the ultrasonic sensor installed below may become small enough. Usually, the focal diameter is evaluated by the half-value width 18 of the ultrasonic intensity.

  Thus, after confirming the focal diameter of the array type ultrasonic sensor, the inspection target surface 2 is inspected. In the inspection, ultrasonic waves are transmitted from the array type ultrasonic sensor 4 into the inspection object 1 using only the array type ultrasonic sensor 4. In this case, a transmission signal shifted in time by the delay time 17 calculated for each piezoelectric vibration element is driven to drive each piezoelectric vibration element to each piezoelectric vibration element of the array type ultrasonic sensor 4 by the delay control device 7. A signal is applied to each piezoelectric vibration element from the ultrasonic transmitter / receiver 6 as a signal, an ultrasonic wave is transmitted from each piezoelectric vibration element, and each piezoelectric vibration element receives the ultrasonic wave reflected from the inspection object 1 and receives each piezoelectric vibration. The element emits an electrical signal as a received signal. The received signal is transmitted to the ultrasonic transmitter / receiver 6, and the delay control device 7 further synthesizes the waveform of the received signal by shifting each piezoelectric vibrating element by the delay time 17. The synthesized received signal is transmitted to the control device 8 and analyzed, and the received waveform is displayed on the waveform display means 9. This operation is performed by electronically shifting each piezoelectric vibration element in the array direction, and mechanically scanning the array-type ultrasonic sensor 4 or the inspection object 1 in the normal direction of the array. The inspection target surface 2 is inspected.

  Next, a specific inspection implementation state will be described with reference to FIG. In FIG. 7, the array type sensor 4 and the inspection object 1 using the scanning means 20 to 22 and the scanning means control device 23 for moving and inspecting the relative position between the array type ultrasonic sensor 4 and the inspection object 1 are shown. Set the relative position and perform the inspection.

  Here, mechanical scanning means is employed as the scanning means 20 to 22, and includes a scanning means 20 that moves in the X-axis direction, a scanning means 21 that moves in the Z-axis direction, and a scanning means 22 that moves in the Y-axis direction. Shows the case.

  These scanning means 20 to 22 are controlled by the scanning means control device 23 to control the moving amount and the moving speed, and operate in synchronization with the control device of the array type ultrasonic inspection apparatus by the synchronization signal 10, and the ultrasonic waveform or Inspection is performed by visualizing the intensity of ultrasound. The inspection result is displayed on the waveform display means 9 as a recorded waveform, and has a function of displaying the inspection result as an image by performing an imaging process with the control device 8 of the inspection apparatus using an array type ultrasonic sensor comprising a computer. . If the inspection target surface 2 inside the inspection target 1 has a defect such as a separation or a void, a reflected wave from the defect is received, and this is measured as a defect image in the inspection target surface, and the waveform display means 9 The defect image is displayed on the screen.

  FIG. 8 summarizes the procedure of the inspection method using the array type ultrasonic sensor, which has been described above. The inspection method using the array type ultrasonic sensor according to the present invention is roughly divided into four parts. First, an ultrasonic sensor for transmitting a sound source is installed, and the distance between the inspection target surface and the ultrasonic sensor is set to a predetermined position.

  Next, the arrival time of the ultrasonic wave transmitted from the ultrasonic sensor to the array ultrasonic sensor is measured by the array ultrasonic sensor. The delay time of the array type ultrasonic sensor is set based on the arrival time of the ultrasonic wave to the array type ultrasonic sensor, and the focal diameter of the ultrasonic wave is confirmed using this.

  If the focal length of the ultrasonic wave is sufficient, the piezoelectric transducer elements can be electronically shifted in the array direction while sending and receiving ultrasonic waves with the array-type ultrasonic sensor using the set delay time. The scanning is performed, and the normal direction of the array is inspected by mechanically scanning the array type ultrasonic sensor 4 or the inspection object 1 and the ultrasonic sensor 3 with a scanning unit.

  Next, an inspection procedure when it is necessary to inspect a plurality of inspection objects at once in a line inspection or the like will be described with reference to FIG. By setting the delay time of an array-type ultrasonic sensor using one or more inspection objects, it is possible to inspect a plurality of inspection objects of the same type at once by using the obtained delay time. Is possible.

  The procedure is set so that after the ultrasonic focusing is confirmed, the scanning means moves to the next inspection object i, and the distance between the inspection object i and the array-type ultrasonic sensor is the same as when the delay time is obtained. To do. Here, the distance may be adjusted to be the same as when the delay time is obtained with reference to the arrival time of the reflected wave reflected from the surface of the inspection object i. After adjusting the distance between the inspection object i and the array-type ultrasonic sensor 4, an inspection is performed using a delay time set in advance. By repeating this operation n times, which is the number of inspection objects, a plurality of inspection objects can be inspected collectively.

  Next, a second embodiment will be described with reference to FIG. FIG. 10 shows an apparatus configuration in which the ultrasonic transmitter / receiver 11 of the ultrasonic sensor 3 installed below the object to be inspected used in the description of FIG. 1 is omitted, and an array type ultrasonic sensor is used instead. In this configuration, one of a plurality of channels of the four ultrasonic transmitters / receivers 6 is assigned and used as a transmitter / receiver of the ultrasonic sensor 3 installed below. One channel of the ultrasonic transmitter / receiver 6 and the ultrasonic sensor 3 are connected by an electric line 24.

  In the case of such a configuration, the transmission signal can be transmitted as a drive signal from the ultrasonic transmitter / receiver 6 to the ultrasonic sensor 3 through the electric line 24. Therefore, in addition to the ultrasonic transmitter / receiver 6 of the array type ultrasonic sensor 4 No ultrasonic transmitter / receiver is required. Therefore, the cost of the apparatus can be reduced. Further, since it is not necessary to install an extra ultrasonic transmitter / receiver outside, it is necessary to synchronize the ultrasonic transmitter / receiver 11 and the control device 8 of the ultrasonic inspection apparatus as in the first embodiment. Since there is no, it becomes a simple structure. The inspection method is the same as the procedure shown in FIG. 8 used in the first embodiment, and the inspection procedure when inspecting a plurality of inspection objects at once is also explained in FIG. It is the same.

  Further, a third embodiment will be described with reference to FIG. The third embodiment is characterized in that each of the piezoelectric vibration elements in a two-dimensional array is used as the array-type ultrasonic sensor 4. Examples of ultrasonic sensors having two-dimensionally arranged piezoelectric vibration elements include a two-dimensional matrix array sensor, a ring array sensor, and a circumferentially divided ring array sensor. In the present invention, any of these may be used. good.

  Here, a case where a two-dimensional matrix array sensor is used will be described as a representative example. The third embodiment is different from the first embodiment in that the array ultrasonic sensor 4 is changed to a two-dimensional matrix array sensor 25, and this point will be described. The two-dimensional matrix array sensor 25 receives the ultrasonic waves 12 transmitted from the ultrasonic sensor 3, focused on the inspection target surface, and passed through the inspection target 1.

  At this time, when the ultrasonic wave transmitted from the ultrasonic sensor 3 is a pulse wave, the time until it reaches the two-dimensional matrix array sensor 25 corresponds to the propagation path of the ultrasonic wave inside the inspection object 1. The ultrasonic sensor 3 is the earliest immediately above and becomes slower as it goes outward. However, here, it is assumed that the inspection object 1 has no acoustic anisotropy.

  The ultrasonic wave 12 reaching the two-dimensional matrix array sensor 25 in this way is received by the ultrasonic transmitter / receiver 6, and the time waveform or ultrasonic intensity is transmitted to the control device 26 of the ultrasonic inspection apparatus of the two-dimensional matrix array. The time change of is recorded. At this time, the control device 8 of the ultrasonic inspection apparatus operates in synchronization with the ultrasonic transmitter / receiver 11 and the synchronization signal 10.

  The arrival time of the ultrasonic waves to each piezoelectric vibration element of the two-dimensional matrix array sensor 25 is obtained from the time waveform of the ultrasonic waves recorded in the control device 26 of the two-dimensional matrix array ultrasonic inspection apparatus. Since the obtained arrival time of the ultrasonic wave becomes a value of each piezoelectric vibration element of the two-dimensional matrix array sensor 25, it becomes a two-dimensional ultrasonic wave arrival time distribution and is used in the same manner as in the first embodiment. The delay time of each piezoelectric vibration element is determined.

  The method for determining the number of elements used for the inspection and the method for confirming the focal diameter are the same as in the first embodiment. As for the inspection method, when the area of the element region of the two-dimensional matrix array sensor is larger than that of the inspection object surface 2, the inspection is performed by electronic scanning of the element.

  Further, when the area of the element region of the two-dimensional matrix array sensor is smaller than that of the inspection target surface 2, an electronic scanning of the element is performed, and the portion that does not satisfy the inspection target surface is an array type. The inspection is performed by mechanically scanning the sensor or the inspection object. The inspection procedure is the same as the procedure shown in FIG. 8 used in the first embodiment, and the inspection procedure when inspecting a plurality of inspection objects at the same time is also described in FIG. Same as the case.

  As described above, the ultrasonic inspection apparatus and the inspection method using the array type ultrasonic sensor according to the embodiment of the present invention are suitable for the array type ultrasonic sensor even when the sound velocity of the material to be inspected and the detailed internal structure are not understood. The inspection can be performed by setting the delay time and selecting the number of elements of the array-type ultrasonic sensor used for the inspection. In addition, since the focal diameter of the ultrasonic wave inside the inspection object can be confirmed, the detection limit of the defect can be known in advance, and the reliability of the inspection is improved. Further, even in the 100% inspection in the line inspection, by setting a delay time for an arbitrary inspection object, it is possible to inspect many other inspection objects of the same type at a time, so that the inspection time can be shortened.

  The present invention can be applied to an ultrasonic inspection apparatus that non-destructively inspects an inspection object using ultrasonic waves.

It is a figure which shows the whole system | strain structure of the ultrasonic inspection apparatus by this invention. In the inspection apparatus and method of this invention, it is a figure explaining the setting method of the distance of an array type ultrasonic sensor and a test object. In the ultrasonic inspection apparatus and method of this invention, it is a figure explaining time until the ultrasonic wave transmitted from the ultrasonic sensor arrives at an array type ultrasonic sensor. It is a figure explaining the intensity | strength of the ultrasonic wave which the ultrasonic wave transmitted from the ultrasonic sensor arrived at the array type ultrasonic sensor in the ultrasonic inspection apparatus and method of this invention. In the ultrasonic inspection apparatus and method of the present invention, the delay time of each piezoelectric vibration element of the array ultrasonic sensor obtained from the time until the ultrasonic wave oscillated from the ultrasonic sensor reaches the array ultrasonic sensor is shown. FIG. It is a figure which shows the confirmation of the focal diameter of an ultrasonic wave with the set delay time in the ultrasonic inspection apparatus and method of this invention. It is a figure which shows the test implementation condition in the ultrasonic inspection apparatus and method of this invention. It is a figure which shows the setting method of the delay time of each piezoelectric vibration element of an array type ultrasonic sensor, and the procedure of a test | inspection. In the ultrasonic inspection apparatus and method of this invention, it is a figure which shows the procedure of implementation in test | inspection of many test objects, such as a line test | inspection. It is a figure which shows the whole system | strain structure of the ultrasonic inspection apparatus concerning 2nd Embodiment in the ultrasonic inspection apparatus and method of this invention. It is a figure which shows the whole system | strain structure of the ultrasonic inspection apparatus concerning 3rd Embodiment in the ultrasonic inspection apparatus and method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inspection object, 2 ... Inspection object surface, 3 ... Ultrasonic sensor, 4 ... Array type ultrasonic sensor, 5 ... Ultrasonic reception signal, 6 ... Ultrasonic transmitter / receiver of array type ultrasonic sensor, 7 ... Delay time control device, 8 ... Control device of ultrasonic inspection device using array type ultrasonic sensor, 9 ... Waveform display means of array type ultrasonic inspection device, 10 ... Synchronization signal, 11 ... Ultrasonic transmitter / receiver, 12 ... Ultrasound,
DESCRIPTION OF SYMBOLS 13 ... Waveform display means of ultrasonic sensor, 14 ... Water tank, 15 ... Arrival time of ultrasonic wave from ultrasonic sensor to array type ultrasonic sensor, 16 ... Reception intensity of ultrasonic wave, 17 ... Delay of array type ultrasonic sensor Time: 18: Half width of ultrasonic intensity, 19: Ultrasound oscillated from array type ultrasonic sensor, 20: Scanning means (X axis), 21: Scanning means (Y axis), 22: Scanning means (Z axis) , 23... Scanning means control device, 25... Two-dimensional matrix array sensor, 26... Control device for two-dimensional matrix array ultrasonic inspection apparatus.

Claims (2)

An array-type ultrasonic sensor and another ultrasonic sensor are placed across the inspection object, and ultrasonic waves transmitted from the other ultrasonic sensor to the inspection object are received by the array-type ultrasonic sensor, The arrival time of the ultrasonic wave from the ultrasonic sensor through the inspection object to each piezoelectric vibration element of the array type ultrasonic sensor is measured, and a delay time used for controlling the ultrasonic transmission / reception signal based on the arrival time is determined. From the array type ultrasonic sensor, the transmission timing of the transmission signal applied to each piezoelectric vibration element and the reception timing of the reception signal output from each piezoelectric vibration element are controlled based on the delay time. In the ultrasonic inspection method for transmitting and receiving ultrasonic waves to the inspection object ,
When inspecting the inspection object with the array type ultrasonic sensor based on the reception intensity of the ultrasonic wave that has reached the piezoelectric vibration elements of the array type ultrasonic sensor through the inspection object from the other ultrasonic sensor An ultrasonic inspection method for selecting the piezoelectric vibration element to be used. Oite to claim 1, when inspecting the other test object said object of the same type, the transmission timing of the transmission signal for applying the delay time the each piezoelectric vibrating elements, from the piezoelectric vibrating element of the An ultrasonic inspection method for inspecting the other inspection object by using the control with the reception timing of the output reception signal.

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