JP2017072475A - Optical nondestructive inspection apparatus and optical nondestructive inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical nondestructive inspection apparatus and an optical nondestructive inspection method that can nondestructively find the area of a joint boundary face between a first member and a second member joined together on the joint boundary surface.SOLUTION: An optical nondestructive inspection apparatus has: a laser output device 27 which emits heating laser light such that intensity at a measurement point SP set on a surface of a first member between a first member 51 and a second member 52 joined on a joint boundary surface 53 varies in a sine wave shape; laser light intensity detection means 41 of detecting intensity of the heating laser light at the measurement point SP; infrared intensity detecting means 31 of detecting intensity of infrared light emitted from the measurement point and varying in a sine wave shape; a phase difference detection device 60 which receives a detection signal from the laser light intensity detecting means and a detection signal from the infrared light intensity detecting means and detecting a phase difference between both the detection means; and a determination device 70 which calculates the area of the joint boundary surface based upon the phase difference received from the phase difference detection device.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an optical nondestructive inspection apparatus and an optical nondestructive inspection method for optically determining the area of a bonded interface between a first member and a second member bonded to each other at a bonded interface.

  In recent years, there are joining of a first member and a second member made of various materials, and inspection of the joining state is desired. In the inspection of the bonding state, conventionally, a sample is appropriately extracted from the production lot, the sample is destroyed and the bonding state is confirmed, and the product of the lot has a bonding state equivalent to the broken sample. I thought it was. In this conventional method, the sample must be broken to confirm the bonding state.

  Here, Patent Document 1 describes a thermophysical property measuring apparatus that measures the thermal conductivity of a sample. The thermophysical property measuring apparatus irradiates the surface of the sample with the first heating light and the second heating light, which are modulated so that the intensity changes sinusoidally, and the intensity of the sinusoidal radiation from the surface of the sample. Detected. Then, the thermal conductivity of the sample is obtained from the phase difference between the intensity of the irradiated sinusoidal first heating light and second heating light and the intensity of the sinusoidal radiation light.

  Patent Document 2 describes a thermal diffusivity measuring device that measures the thermal diffusivity of a sample. The thermal diffusivity measuring device includes a heating laser beam irradiation means for irradiating a heating laser beam, a frequency generator for periodically changing the intensity of the heating laser beam, an infrared light condensing means, a radiation thermometer, a lock An in-amplifier and control means are provided. Then, from one side of the sample, a heating laser beam whose intensity is modulated sinusoidally with a signal from the frequency generator is irradiated, and infrared light having a sinusoidal intensity emitted from the other side of the sample is reddish. The light is input to the lock-in amplifier via the external light collecting means and the radiation thermometer. A signal from a frequency generator is also input to the lock-in amplifier. The control means inputs the phase difference between the signal from the frequency generator and the emitted infrared light from the lock-in amplifier, and based on the frequency of the signal from the frequency generator and the phase difference, The diffusion rate is being calculated.

JP 2012-189525 A JP 2011-185852 A

  The thermophysical property measuring apparatus described in Patent Document 1 can inspect the thermal conductivity of a sample in a non-destructive manner, but cannot determine the bonding state of the sample in which the first member and the second member are bonded. Moreover, although the thermal diffusivity measuring apparatus of patent document 2 can test | inspect the thermal diffusivity of a sample nondestructively, it cannot obtain | require the joining state of the sample which joined the 1st member and the 2nd member.

  The present invention was devised in view of such points, and in the first member and the second member joined to each other at the joining interface, the area of the joining interface can be obtained nondestructively. It is an object to provide a nondestructive inspection apparatus and an optical nondestructive inspection method.

  In order to solve the above problems, an optical nondestructive inspection apparatus and an optical nondestructive inspection method according to the present invention take the following means. First, the first invention of the present invention irradiates a heating laser to a measurement point set on the surface of the first member of the measurement object that is the first member and the second member that are joined to each other at the joining interface. An optical nondestructive inspection apparatus for obtaining an area of the bonding interface based on information acquired from the measurement point or information on the heating laser and information acquired from the measurement point, Laser output device for emitting the heating laser so that the intensity at the measurement point changes in a sine wave shape, laser intensity detection means for detecting the intensity of the heating laser at the measurement point, and radiation from the measurement point Infrared intensity detecting means for detecting the intensity of the infrared rays, which changes in a sinusoidal shape, and a detection signal from the laser intensity detecting means and a detection signal from the infrared intensity detecting means A phase difference detection device that detects a phase difference between the intensity of the heating laser that is captured and changes sinusoidally and the intensity of the infrared that is changed sinusoidally; and the phase difference captured from the phase difference detection device And a determination device that calculates a bonding interface area that is an area of the bonding interface based on the optical nondestructive inspection device.

  Next, a second invention of the present invention is the optical nondestructive inspection apparatus according to the first invention, wherein the intensity of the heating laser at the measurement point is the value for the heating applied to the measurement point. The intensity of the irradiation light that is a laser and changes in a sinusoidal shape, or the intensity of the reflected light of the heating laser reflected at the measurement point and the reflection that changes in a sinusoidal shape This is an optical non-destructive inspection device.

  Next, a third invention of the present invention is the optical nondestructive inspection device according to the first invention or the second invention, wherein the determination device includes a first physical property of the first member. Physical characteristics, second physical characteristics that are physical characteristics of the second member, and interface physical characteristics that are physical characteristics of the bonding interface are stored. And the said determination apparatus makes the said 1st member and the said 2nd member into one based on the said phase difference, the frequency of the said laser for heating which changes intensity | strength in a sine wave shape, and the said 1st physical characteristic. Obtaining the thermal diffusivity regarded as a member, and obtaining the thermal conductivity considering the first member and the second member as one member based on the obtained thermal diffusivity and the first physical characteristics. A junction which is a thermal resistance of the junction interface from the obtained thermal conductivity, an apparent thermal resistance of the measurement object based on the phase difference, the first physical characteristic, and the second physical characteristic. An optical nondestructive inspection apparatus that calculates an interface thermal resistance and calculates the bonded interface area based on the determined bonded interface thermal resistance and the interface physical characteristics.

  Next, a fourth invention of the present invention is the optical nondestructive inspection device according to the third invention, wherein the determination device is connected to a predetermined communication line, and the first physical characteristic, An optical nondestructive inspection apparatus that receives and stores the second physical characteristic and the interface physical characteristic via the communication line.

  Next, a fifth invention of the present invention is the optical nondestructive inspection apparatus according to the third invention or the fourth invention, wherein the first physical property, the second physical property, and the interface physical property are The thermal diffusion length, which is the distance from the measurement point in the first member to the contact surface of the first member and the second member, the specific heat capacity of the first member, the density of the first member, An optical nondestructive inspection apparatus including a thermal resistance of a first member, a thermal resistance of the second member, a thickness of the bonding interface, or a bonding coefficient related to the bonding interface area with respect to the bonding interface thermal resistance. is there.

  Next, a sixth invention of the present invention is the optical nondestructive inspection device according to any one of the first to fifth inventions, wherein the laser output device outputs an input modulation signal. A semiconductor laser light source for emitting a laser whose intensity is modulated on the basis thereof, and a modulation signal output means for outputting the modulation signal, or a laser having a predetermined intensity is directed toward the acousto-optic modulator An optical nondestructive inspection comprising an emitted laser light source, an acousto-optic modulator that diffracts an incident laser based on an input modulation signal, and a modulation signal output means for outputting the modulation signal Device.

  Next, according to a seventh aspect of the present invention, a heating laser is irradiated to a measurement point set on the surface of the first member of the measurement object that is the first member and the second member that are joined to each other at the joining interface. An optical nondestructive inspection method for determining an area of the bonding interface based on information acquired from the measurement point, or information on the heating laser and information acquired from the measurement point, An output device, a phase difference detection device, and a determination device are used. A laser emission step of emitting the heating laser so that the intensity at the measurement point changes in a sine wave shape at the laser output device; and the heating laser at the measurement point at the phase difference detection device. A laser intensity measuring step for measuring the intensity of the infrared ray, and an infrared intensity measuring step for measuring the intensity of the infrared ray radiated from the measurement point and changing in a sinusoidal shape with the phase difference detection device, The phase difference between the intensity of the heating laser that changes to a measured sine wave and the intensity of the infrared that changes to a measured sine wave is obtained by the phase difference detection device. Phase difference measuring step for outputting to the determination device, and the determination device calculates a bonding interface area, which is an area of the bonding interface, based on the phase difference It has a step, and is an optical non-destructive testing methods.

  Next, an eighth invention of the present invention is the optical nondestructive inspection method according to the seventh invention, wherein the intensity of the heating laser at the measurement point is applied to the measurement point irradiated to the measurement point. The intensity of the irradiation light that is a laser and changes in a sinusoidal shape, or the intensity of the reflected light of the heating laser reflected at the measurement point and the reflection that changes in a sinusoidal shape This is an optical nondestructive inspection method.

  Next, a ninth invention of the present invention is the optical nondestructive inspection method according to the seventh invention or the eighth invention, wherein the determination device has a first physical property that is a physical characteristic of the first member. Characteristics, second physical characteristics that are physical characteristics of the second member, and interface physical characteristics that are physical characteristics of the bonding interface are stored. In the bonding interface area calculating step, the determination device uses the first member based on the phase difference, the frequency of the heating laser whose intensity changes sinusoidally, and the first physical characteristic. And the second member are regarded as one member, and based on the obtained thermal diffusivity and the first physical characteristic, the first member and the second member are combined into one member. Obtaining the thermal conductivity regarded as a member, from the obtained thermal conductivity, the apparent thermal resistance of the measurement object based on the phase difference, the first physical characteristic, and the second physical characteristic The optical nondestructive inspection method calculates a bonding interface thermal resistance which is a thermal resistance of the bonding interface, and calculates the bonding interface area based on the determined bonding interface thermal resistance and the interface physical characteristics.

  Next, a tenth invention of the present invention is the optical nondestructive inspection method according to the ninth invention, wherein the first physical property, the second physical property, and the interface physical property are predetermined. This is an optical nondestructive inspection method that is distributed via the communication line and stored in the determination device.

  Next, an eleventh aspect of the present invention is the optical nondestructive inspection method according to the ninth aspect or the tenth aspect, wherein the first physical characteristic, the second physical characteristic, and the interface physical characteristic are The thermal diffusion length, which is the distance from the measurement point in the first member to the contact surface of the first member and the second member, the specific heat capacity of the first member, the density of the first member, An optical nondestructive inspection method comprising: a thermal resistance of the first member; a thermal resistance of the second member; a thickness of the bonding interface; or a bonding coefficient relating to the bonding interface area with respect to the bonding interface thermal resistance. is there.

  Next, a twelfth aspect of the present invention is an optical nondestructive inspection method according to any one of the seventh to eleventh aspects of the present invention, in which an input modulation signal is applied as the laser output device. The laser output device comprising: a semiconductor laser light source that emits a laser whose intensity is modulated on the basis thereof; and a modulation signal output means that outputs the modulation signal; or an acousto-optic modulation of a laser having a predetermined intensity A laser light source that emits light toward the device, an acousto-optic modulator that diffracts an incident laser based on an input modulation signal, and a modulation signal output unit that outputs the modulation signal. An optical nondestructive inspection method using a laser output device.

  According to the first invention, the area of the bonding interface is obtained based on the phase difference between the intensity of the heating laser that changes sinusoidally and the intensity of the infrared light that changes sinusoidally. Therefore, in the first member and the second member that are bonded to each other at the bonding interface, the area of the bonding interface can be obtained without destruction.

  According to the second aspect of the invention, the intensity of the heating laser detected by the laser intensity detecting means is the intensity of the irradiation light that is the heating laser irradiated to the measurement point or the heating laser reflected at the measurement point. The intensity of the reflected light of the laser. Therefore, a heating laser that is easy to measure can be selected according to the surface state of the first member, etc., which is convenient.

  According to the third invention, the phase difference, the frequency of the heating laser, the first physical characteristic, the second physical characteristic, the interface physical characteristic, and the apparent thermal resistance of the measurement object are used. The thermal diffusivity of the first member, the thermal conductivity in which the first member and the second member are regarded as one member, the bonding interface thermal resistance, and the bonding interface area can be obtained nondestructively.

  According to the fourth invention, even if the first member and the second member, which are measurement objects, are not different in material and size, there are a plurality of measurement objects in various combinations. In addition, the first physical characteristic, the second physical characteristic, and the interface physical characteristic corresponding to the measurement object can be easily stored, which is convenient.

  According to the fifth aspect, specific characteristics in the first physical characteristic, the second physical characteristic, and the interface physical characteristic are specified, and the area of the bonding interface can be appropriately obtained.

  According to the sixth aspect of the present invention, a heating laser whose intensity changes sinusoidally can be obtained relatively easily.

  According to the seventh aspect of the present invention, it is possible to appropriately realize an optical nondestructive inspection method capable of obtaining the area of the bonding interface nondestructively in the first member and the second member bonded to each other at the bonding interface. it can.

  According to the eighth aspect of the invention, the intensity of the heating laser detected by the laser intensity detecting means is the intensity of the irradiation light that is the heating laser irradiated to the measurement point, or the heating reflected by the measurement point. The intensity of the reflected light of the laser. Therefore, a heating laser that is easy to measure can be selected according to the surface state of the first member, etc., which is convenient.

  According to the ninth aspect, the phase difference, the heating laser frequency, the first physical characteristic, the second physical characteristic, the interface physical characteristic, and the apparent thermal resistance of the measurement object are used. Appropriately realizing an optical nondestructive inspection method capable of obtaining the thermal diffusivity of the first member, the thermal conductivity considering the first member and the second member as one member, the bonding interface thermal resistance, and the bonding interface area can do.

  According to the tenth invention, it is convenient because the determination device can easily store the first physical characteristic, the second physical characteristic, and the interface physical characteristic corresponding to the measurement object.

  According to the eleventh aspect, the specific characteristics of the first physical characteristic, the second physical characteristic, and the interface physical characteristic are specified, and the area of the bonding interface can be obtained appropriately.

  According to the twelfth aspect of the present invention, a heating laser whose intensity changes sinusoidally can be obtained relatively easily.

It is a figure explaining 1st Embodiment of the whole structure of an optical nondestructive inspection apparatus. It is a figure explaining 2nd Embodiment of the whole structure of an optical nondestructive inspection apparatus. It is a flowchart explaining the example of the process sequence of a determination apparatus and a phase difference detection apparatus. It is a figure explaining the example of the physical characteristic information memorize | stored in the determination apparatus. It is a figure explaining the example of the irradiation light intensity | strength and infrared rays intensity | strength input into a phase difference detection apparatus, and the example of the measured phase difference. It is a figure explaining the example of the model of the 1st member and the 2nd member joined mutually at the joining interface, the 1st physical characteristic, the 2nd physical characteristic, and the interface physical characteristic. It is a figure explaining the example of the determination result displayed on a determination apparatus.

  Hereinafter, embodiments of the present invention will be described in order with reference to the drawings. Both the optical nondestructive inspection apparatus 1 according to the first embodiment and the optical nondestructive apparatus 1A according to the second embodiment described below and the first member 51 and the first member 51 bonded to each other at the bonding interface 53 are used. A temperature response acquired from the measurement point SP or heating by irradiating the measurement point SP set on the surface of the first member 51 of the measurement object which is the two member 52 with a heating laser whose intensity changes in a sine wave shape. The area of the bonding interface 53 (information on the area) is obtained based on the detection of the laser for use and the temperature response acquired from the measurement point SP. The “bonding interface” refers to the above-described “bonded” area and a planar area.

  Moreover, when calculating | requiring the area of a joining interface based on the information regarding the laser for heating and the information acquired from measurement point SP, the intensity | strength of the irradiation light (heating laser) which changes to the sine wave shape irradiated to measurement point SP, The said area is calculated | required based on the phase difference with the intensity | strength of the infrared rays (infrared ray of predetermined wavelength) radiated | emitted from measurement point SP, and the intensity | strength of the intensity | strength of irradiation light of a sine wave shape.

  Further, when the area of the bonding interface is obtained based on information acquired from the measurement point SP, the intensity of the reflected light (reflected light of the heating laser) reflected at the measurement point SP and the measurement point SP, and the measurement point The said area is calculated | required based on the phase difference of the intensity | strength of the infrared rays (infrared rays of a predetermined wavelength) radiated | emitted from SP, and the intensity | strength of the intensity | strength of the reflected light of a sine wave shape.

● [Overall Configuration of Optical Nondestructive Inspection Apparatus 1 of First Embodiment (FIG. 1)]
First, the overall configuration of the optical nondestructive inspection apparatus 1 according to the first embodiment will be described with reference to FIG. The optical nondestructive inspection apparatus 1 according to the first embodiment measures the intensity of the heating laser by measuring the intensity of the irradiation light that is the heating laser irradiated to the measurement point and changes in a sinusoidal shape. The example of the optical nondestructive inspection device of the type which measures intensity is shown. The optical nondestructive inspection apparatus 1 includes a laser output device 27, a condensing unit 10 (a reflective objective lens in the examples of FIGS. 1 and 2), a laser intensity detecting unit 41, an infrared intensity detecting unit 31, and a phase difference detecting unit 60. And a determination device 70 and the like. In the following description, the first member 51 is copper, the second member 52 is copper, and the first member 51 and the second member 52 are joined at the joining interface 53 by welding. explain.

  The laser output device 27 includes, for example, a semiconductor laser light source 21, a collimator lens 22, and a modulation signal output unit 25. The modulation signal output means 25 is, for example, an oscillator, and generates a modulation signal whose voltage changes in a sine wave shape with a predetermined frequency and a predetermined amplitude based on a control signal from the determination device 70. The semiconductor laser light source 21 includes an intensity adjustment input for adjusting the intensity. A modulation signal is input from the modulation signal output means 25 to the intensity adjustment input. The semiconductor laser light source 21 emits a heating laser La whose intensity changes in a sine wave shape based on the modulation signal from the modulation signal output means 25. The heating laser La emitted from the semiconductor laser light source 21 is converted into parallel light by the collimator lens 22 and reaches the heating laser selective reflection means 23. If the emitted heating laser is parallel light, the collimating lens 22 can be omitted. Accordingly, the intensity of the heating laser La focused on the measurement point SP changes in a sine wave shape, and its frequency is synchronized with the frequency of the modulation signal. Note that the output of the heating laser is adjusted to an output that can be heated without destroying the measurement object.

  The condensing means 10 directs the parallel light incident from one side along its own optical axis (from above in the example of FIG. 1) toward the measurement point SP set on the surface of the first member 51 as a focal position. Then, the light is condensed and emitted from the other side (from the lower side in the example of FIG. 1). Further, the condensing unit 10 converts the light emitted and reflected from the measurement point SP (which is a focal position) and incident from the other side into the first measurement light L11 which is parallel light along its own optical axis. And exits from one side. The condensing means 10 can be composed of a condensing lens that transmits light and refracts it. However, since the condensing unit 10 handles light of a plurality of different wavelengths, it is not preferable for a condensing lens that generates chromatic aberration. Thus, the (aspherical) reflecting mirrors 10A and 10B constitute the light condensing means to eliminate the occurrence of chromatic aberration and to cope with a wide wavelength band. The condensing means 10 is preferably an objective lens.

  The heating laser selective reflection means 23 is disposed at a position where the optical axis of the heating laser La emitted from the laser output device 27 and the optical axis of the light converging means 10 intersect. For example, the heating laser selective reflection means 23 is a dichroic mirror that reflects light having the wavelength of the heating laser La and transmits light having a wavelength other than the wavelength of the heating laser. In the example of FIG. 1, the heating laser selective reflection means 23 transmits light having the wavelength of the heating laser La about several [%] (for example, about 2%). A laser intensity detecting means 41 is arranged at the tip through which the heating laser La has passed.

  The laser intensity detection means 41 is a photosensor that can detect the energy of light having a wavelength of a heating laser, for example. The heating laser transmitted through the heating laser selective reflection means 23 (heating laser whose intensity changes in a sine wave shape) is condensed by the condenser lens 42 and input to the laser intensity detection means 41. The detection signal from the laser intensity detection means 41 is amplified by, for example, a sensor amplifier and input to the phase difference detection device 60.

  The first measurement light L11 (measurement light including irradiation light reflected at the measurement point SP and infrared light emitted from the measurement point SP) converted into parallel light by the condensing means 10 is emitted from the measurement point SP. Infrared light having a predetermined wavelength is included. An infrared intensity detection means 31 is disposed at the tip of the first measurement light L11.

  The infrared intensity detecting means 31 is an infrared sensor capable of detecting infrared energy having a predetermined wavelength, for example. Infrared light having a predetermined wavelength (infrared light whose intensity changes in a sine wave shape) included in the first measurement optical path L <b> 11 is collected by the condenser lens 32 and input to the infrared intensity detection means 31. The detection signal from the infrared intensity detection means 31 is amplified by, for example, a sensor amplifier and input to the phase difference detection device 60.

  The phase difference detection device 60 is, for example, a lock-in amplifier, and has a detection signal (sinusoidal detection signal 1) whose intensity changes in a sine wave form from the laser intensity detection means 41 and a sine wave intensity from the infrared intensity detection means 31. Is input as a detection signal (sinusoidal detection signal 2). The phase difference detection device 60 measures the phase difference between the sine wave detection signal 1 and the sine wave detection signal 2 and outputs the measured phase difference to the determination device 70. The detection signal from the laser intensity detecting means 41 is a signal corresponding to the intensity of the irradiation light that is the heating laser La irradiated to the measurement point SP and changes in a sinusoidal shape. Further, the detection signal from the infrared intensity detecting means 31 is a signal corresponding to the intensity of the infrared ray radiated from the measurement point SP and changing in the form of a sine wave. The phase difference includes information regarding the area of the bonding interface.

  The determination device 70 is, for example, a personal computer, outputs a control signal to the laser output device 27, and takes in the phase difference from the phase difference detection device 60. Then, as will be described later, the determination device 70 captures the phase difference, the frequency of the heating laser whose intensity at the measurement point SP changes sinusoidally, and the stored first physical characteristics (physical properties of the first member). Characteristics), second physical characteristics (physical characteristics of the second member), and interface physical characteristics (physical characteristics of the bonding interface), the area of the bonding interface 53 is obtained. Details of the first physical property, the second physical property, the interface physical property, and the procedure for obtaining the area of the bonding interface will be described later.

  For example, when the optical nondestructive inspection apparatus 1 is provided in a facility, a determination device 70 is connected to a communication line 80 (for example, an in-facility LAN) in the facility, and the first physical characteristic, the second physical characteristic, and the interface physical characteristic are connected. It is convenient to distribute physical characteristic information (see FIG. 4) including “” from the distribution device 81 (distribution server) connected to the communication line 80. The determination device 70 of the optical nondestructive inspection apparatus 1 receives and stores physical property information including the first physical property, the second physical property, and the interface physical property via the communication line 80. In particular, when a plurality of optical non-destructive devices 1 are provided in a facility, a plurality of optical non-destructive devices 1 can be easily and easily compared with the case where the first physical characteristics, the second physical characteristics, and the interface physical characteristics are stored one by one. This is convenient because the destruction device 1 can receive and store the first physical characteristic, the second physical characteristic, and the interface physical characteristic.

● [Overall Configuration of Optical Nondestructive Inspection Apparatus 1A of Second Embodiment (FIG. 2)]
Next, the overall configuration of the optical nondestructive inspection apparatus 1A according to the second embodiment will be described with reference to FIG. The optical nondestructive inspection apparatus 1A according to the second embodiment measures the intensity of the heating laser by measuring the intensity of the reflected light of the heating laser reflected at the measurement point and changing in a sinusoidal shape. The example of the optical nondestructive inspection device of the type which measures intensity is shown. The optical nondestructive inspection apparatus 1A of the second embodiment is different from the optical nondestructive inspection apparatus 1 of the first embodiment in that the laser output device 27 is changed to the laser output device 27A and the heating laser La is changed. The difference is that it is linear, the heating laser selective reflection means 23 is omitted, and the reflected light selective reflection means 43 is added. Hereinafter, these differences will be mainly described. Since the configuration other than the difference is as described in the first embodiment, the description is omitted. In the example of FIG. 2, for the sake of explanation, the incident angle of the heating laser La that is incident light on the workpiece (the first member 51 and the second member 52 bonded at the bonding interface 53), and the heating laser La An example is shown in which the tilt angle of the workpiece is set in accordance with the reflection angle of reflected light (the angle of the optical axis X).

  The laser output device 27A includes, for example, a laser light source 21A that emits a linear heating laser La, an acousto-optic modulator 24, and a modulation signal output means 25, and the heating applied to the measurement point SP. The heating laser La is emitted based on a control signal from the determination device 70 so that the intensity of the laser La changes in a sine wave shape. The modulation signal output means 25 is, for example, an oscillator, and generates a modulation signal whose voltage changes in a sine wave shape with a predetermined frequency and a predetermined amplitude based on a control signal from the determination device 70. The linear heating laser emitted from the laser light source 21A is input to the acousto-optic modulator 24 and is diffracted by the acousto-optic modulator 24 as described later. The acousto-optic modulator 24 includes an optical modulator (EOM) device and a surface acoustic wave (SAW) device. For example, when an optical modulator device transmits light into a piezoelectric crystal, an electric field or an ultrasonic wave is applied based on the modulation signal from the modulation signal output means 25 to generate a piezoelectric effect, and the refractive index in the piezoelectric crystal is changed. Change. The refracted heating laser is extracted as diffracted light. That is, the irradiation position of the heating laser La swings around the measurement point SP, and as a result, the intensity of the heating laser La irradiated to the measurement point SP changes in a sine wave shape, and the frequency thereof is the frequency of the modulation signal. Sync to. Note that the output of the heating laser is adjusted to an output that can be heated without destroying the measurement object. Further, the heating laser La emitted from the laser output device 27A is focused on the measurement point SP by the objective lens LT after passing through the pinhole PH, for example.

  The reflected light selective reflection means 43 is disposed at any position in the optical path of the first measurement light L11 (measurement light including irradiation light reflected at the measurement point SP and infrared light emitted from the measurement point SP). Yes. For example, the reflected light selective reflection means 43 reflects the light having the wavelength of the reflected light (that is, the wavelength of the heating laser) reflected by the heating laser La at the measurement point SP and transmits light other than the wavelength of the reflected light. It is a mirror. A condensing lens 42 and a laser intensity detecting means 41 are disposed at the point where the reflected light selective reflecting means 43 reflects the light having the wavelength of the reflected light. The condensing lens 42 and the laser intensity detection means 41 are the same as those described in the first embodiment, and thus description thereof is omitted.

[Processing procedure of determination device 70 and phase difference detection device 60 (FIGS. 3 to 5)]
Next, an example of processing procedures of the determination device 70 and the phase difference detection device 60 will be described using the flowchart shown in FIG. For example, when the operator activates the determination device 70, the phase difference detection device 60 is activated in conjunction with the determination device 70. The determination device 70 proceeds to step S15, and the phase difference detection device 60 proceeds to step S140.

  First, the processing procedure of step S15 to step S35 in the determination apparatus 70 will be described. In step S15, the determination device 70 determines whether there is received data (data received via the communication line 80). If there is received data (Yes), the process proceeds to step S20, and there is no received data. (No) advances to step S30.

  When the process proceeds to step S20, the determination apparatus 70 receives data via the communication line 80, and proceeds to step S25. Then, in step S25, the determination device 70 determines whether or not the reception is finished. If the reception is finished (Yes), the process proceeds to step S30. If the reception is not finished (No), the process returns to step S20. .

  The data received by the determination device 70 is physical characteristic information distributed from the distribution device 81 shown in FIGS. 1 and 2, and FIG. 4 shows an example of the physical characteristic information 70A. For example, the physical property information 70A includes a product number, a first physical property, a second physical property, an interface physical property, an area allowable minimum value, and an area allowable maximum value. For example, the distribution device 81 distributes the physical property information at a predetermined timing (every time the product number of the measurement target to be inspected in the facility changes, every time the physical property information is changed, etc.), and the determination device 70 The physical characteristic information is received from the distribution device 81 via the communication line 80, and the received physical characteristic information is stored.

  Since there are a plurality of measurement objects according to the material of the first member, the size of the first member, the material of the second member, etc., the measurement object is distinguished by “product number”. And according to the “product number”, the thermal diffusion length (x) (of the first member), the specific heat capacity (c1) (of the first member), the density (ρ1) (of the first member), (of the first member) ) Thermal resistance (R1), thermal resistance (R2) (of the second member), bonding coefficient (Ks) (or bonding interface thickness (d)), area allowable minimum value, area allowable maximum value are associated with each other. ing.

  The first physical characteristic is physical information related to the first member 51, and the thermal diffusion length (x) of the first member, the specific heat capacity (c1) of the first member, the density (ρ1) of the first member, and the first member Thermal resistance (R1). The heat diffusion length (x) of the first member is a distance from the measurement point SP to the contact surface of the first member and the second member as shown in FIG. The second physical information is physical information related to the second member 52 and includes the thermal resistance (R2) of the second member. The interface physical characteristics include a bonding coefficient Ks with respect to the bonding area in consideration of physical characteristics regarding the bonding interface 53 (corresponding to a bonding coefficient regarding the bonding interface area with respect to the bonding interface thermal resistance) or a thickness (d) of the bonding interface.

  The area allowable minimum value indicates the minimum value when it is determined to be normal in the area of the joint interface finally calculated in this flowchart. The area allowable maximum value indicates the maximum value when it is determined to be normal in the area of the joint interface finally calculated in this flowchart. That is, the determination device 70 determines that the bonding state of the first member and the second member is normal when the calculated area of the bonding interface is not less than the area allowable minimum value and not more than the area allowable maximum value, and is calculated. When the area of the bonded interface is smaller than the allowable area minimum value or larger than the allowable area maximum value, it is determined that the bonded state of the first member and the second member is abnormal.

  When the process proceeds to step S30, the determination device 70 determines whether or not there is a measurement instruction from the worker. If there is a measurement instruction (Yes), the process proceeds to step S25, and if there is no measurement instruction (No), the process proceeds to step S30. Return. The measurement instruction includes an input of “product number”, and the operator inputs the product number from a keyboard, a barcode reader (when a barcode corresponding to the product number is attached to the measurement object), or the like. .

  When the process proceeds to step S35, the determination device 70 outputs a control signal to the laser output device 27 (or the laser output device 27A). Based on the input control signal, the laser output device 27 (or laser output device 27A) emits a heating laser so that the intensity of the heating laser irradiated to the measurement point SP changes in a sine wave shape. And the determination apparatus 70 waits for the input of the phase difference from the phase difference detection apparatus 60 in step S60, after finishing the process of step S35. The process of step S35 corresponds to a laser emission step of emitting a heating laser so that the intensity at the measurement point SP changes in a sine wave shape.

  Next, the processing procedure of steps S140 to S155 in the phase difference detection device 60 will be described. In step S140, the phase difference detection device 60 determines whether or not a detection signal is input from the laser intensity detection means 41 (whether there is a heating laser that is irradiation light (see FIG. 1) or reflected light (see FIG. 2)). If the detection signal (heating laser) is input (Yes), the process proceeds to step S145. If the detection signal (heating laser) is not input (No), the process returns to step S140.

  When the process proceeds to step S145, the phase difference detection device 60 determines whether there is a temperature response based on the detection signal from the infrared intensity detection means 31, and when there is a temperature response (Yes), the process proceeds to step S150, where the temperature response If there is no (No), the process returns to step S145. The determination may be made based on the presence or absence of input of infrared rays having a predetermined wavelength.

  When the process proceeds to step S150, the phase difference detection device 60, based on the detection signal from the laser intensity detection means 41, the irradiation light (in the case of the configuration of FIG. 1) or the reflected light (FIG. In the case of the configuration). FIG. 5 shows an example of measured irradiation light (or reflected light). The phase difference detection device 60 measures infrared light whose intensity changes in a sine wave shape based on the detection signal from the infrared intensity detection means 31. FIG. 5 shows an example of measured infrared rays. The phase difference detection device 60 then detects the phase difference δ (see FIG. 5) between the measured irradiation light (or reflected light) (the intensity changes in a sine wave shape) and the measured infrared light (the intensity changes in a sine wave shape). ) And the process proceeds to step S155.

  The processing in step S150 is the intensity of the reflected light of the heating laser reflected at the measurement point SP and the intensity of the reflected light that changes in a sine wave shape, or the irradiation that is the heating laser that is applied to the measurement point SP. It includes a laser intensity measurement step for measuring the intensity of light and the intensity of irradiation light that changes in a sinusoidal shape. Further, the process of step S150 includes an infrared intensity measurement step of measuring the intensity of infrared rays emitted from the measurement point SP and changing in the form of a sine wave. The process of step S150 calculates the phase difference between the intensity of reflected light or irradiation light that changes in a measured sine wave shape and the intensity of infrared light that changes in a measured sine wave shape, and calculates the calculated phase difference. A phase difference measurement step of outputting to the determination device.

  In step S155, the phase difference detection device 60 outputs the measured phase difference δ toward the determination device 70, and returns to step S140.

  Next, the process procedure of step S60 to step S80 in the determination apparatus 70 will be described. In step S60, the determination device 70 determines whether or not a phase difference is input from the phase difference detection device 60. If there is a phase difference input (Yes), the process proceeds to step S65, and if there is no phase difference input ( No) returns to step S60.

  When the process proceeds to step S65, the determination device 70 takes in the phase difference, outputs a control signal to the laser output device 27 (or laser output device 27A), and for heating from the laser output device 27 (or laser output device 27A). The laser emission is stopped and the process proceeds to step S70.

In step S70, the determination device 70 calculates the thermal diffusivity αt when the first member and the second member are regarded as one member based on the captured phase difference, and proceeds to step S75. When the first member and the second member are regarded as one member, the thermal diffusivity is αt, the phase difference is δ (output value from the phase difference detection device 60), and the irradiation light (or reflected light) is a heating laser. Where f is the frequency and x is the thermal diffusion length of the first member 51, the following (Equation 1) holds. From this (Equation 1), the determination device 70 is based on the phase difference δ, the frequency f of the irradiated light (or reflected light), and the first physical characteristics (in this case, the thermal diffusion length x of the first member). Thus, the thermal diffusivity αt can be obtained. Note that the frequency f of the irradiation light (or reflected light) is known in advance and may be stored in advance in the determination device 70, or the phase difference from the irradiation light (or reflected light) measured by the phase difference detection device 60. The detection device 60 may obtain the frequency f and output the obtained frequency f to the determination device 70. The thermal diffusion length x of the first member is specified by the physical characteristic information (see FIG. 4) stored in the determination device 70 and the product number input in step S30. The thermal diffusion length x is the distance from the measurement point on the first member to the contact surface between the first member and the second member, and is given by, for example, a data table. FIG. 6 shows an example of a model of the first member 51 and the second member 52 (measurement object) joined together at the joining interface 53.
αt = π · f · (x / δ) ² (Formula 1)

In step S75, the determination apparatus 70 calculates the thermal conductivity λt when the first member and the second member are regarded as one member based on the calculated thermal diffusivity αt, and proceeds to step S80. When the thermal conductivity is λt, the thermal diffusivity is αt, the specific heat capacity of the first member is c1, and the density of the first member is ρ1, the following (Equation 2) is established. The determination device 70 can obtain the thermal conductivity λt based on the thermal diffusivity αt and the first physical characteristics (in this case, the specific heat capacity c1 of the first member and the density ρ1 of the first member). . The specific heat capacity and density of the first member are specified by the physical characteristic information (see FIG. 4) stored in the determination device 70 and the product number input in step S30.
λt = αt · ρ1 · c1 (Formula 2)

  In step S80, the determination apparatus 70 calculates a bonding interface area S that is the area of the bonding interface 53 based on the calculated thermal conductivity λt, and determines that the calculated bonding interface area S is normal or abnormal. A result is output (refer FIG. 7), and a process is complete | finished.

Here, the thermal resistance of the first member is R1, the thermal resistance of the second member is R2, the thermal resistance of the entire measurement object estimated from the thermal conductivity λt is Rt, and the thermal resistance of the bonding interface is the bonding interface thermal resistance. Is Rs, the following (Equation 3) holds. Further, when the bonding interface thermal resistance is Rs, the bonding interface area is S, and the bonding coefficient regarding the bonding interface area S with respect to the bonding interface thermal resistance Rs is Ks, the following (Equation 4) is established. From (Expression 4), (Expression 5) can be obtained. Ks may be estimated by Ks = d / λ1 where d is the thickness of the bonding interface. Further, λ1 is the thermal conductivity of the first member, and is obtained in advance. Therefore, (Expression 6) can be obtained from (Expression 5). Note that the bonding coefficient Ks and the thickness d of the bonding interface are obtained in advance from test results and simulation results.
Rs = Rt− (R1 + R2) (Formula 3)
Rs = (1 / S) · Ks (Formula 4)
S = (1 / Rs) · Ks (Formula 5)
S = (1 / Rs) · (d / λ1) (Formula 6)

  For the apparent thermal resistance Rt of the entire measurement object (first member and second member), the apparent thermal conductivity λt is obtained from the phase difference δ, and the thermal conductivity λt is inversely proportional to the thermal resistance Rt. The apparent thermal resistance Rt of the entire object to be measured can be obtained from the λt-Rt characteristic data or the like. The thermal resistance R1 of the first member and the thermal resistance R2 of the second member are specified by the physical characteristic information (see FIG. 4) stored in the determination device 70 and the product number input in step S30. If the material and size (or mass) of the first member are known, the thermal resistance R1 of the first member is known. If the material and size (or mass) of the second member is known, the second member The thermal resistance R2 is known. From these and (Equation 3), the value of Rs can be obtained. The determination device 70 can calculate the bonding interface area S of the bonding interface 53 from the obtained Rs value and (Expression 5) or (Expression 6). Therefore, the determination device 70 includes the first member thermal conductivity λ1, the phase difference δ, the first physical characteristic (in this case, the thermal resistance R1 of the first member), and the second physical characteristic (in this case, the second The bonding interface area S is calculated based on the thermal resistance R2) of the member and the interface physical characteristics (in this case, the bonding coefficient Ks or the thickness d of the bonding interface). The processes in steps S70 to S80 correspond to a bonding interface area calculating step for calculating the bonding interface area based on the phase difference.

  FIG. 7 shows an example in which determination result information 70 </ b> G including the calculated bonding interface area S is displayed on the display unit of the determination device 70. The allowable minimum value (min) in FIG. 7 is the area minimum allowable value specified by the physical characteristic information (see FIG. 4) stored in the determination apparatus 70 and the product number input in step S30. Further, the allowable maximum value (max) in FIG. 7 is the maximum allowable area value specified by the physical characteristic information (see FIG. 4) stored in the determination device 70 and the product number input in step S30. . The determination device 70 determines that the bonding state is “normal” when the calculated area S of the bonding interface is not less than the allowable minimum value (min) and not more than the allowable maximum value (max), and the allowable minimum value (min ) Or larger than the allowable maximum value (max), it is determined that the bonding state is “abnormal”. The example of FIG. 7 shows an example when it is determined as “normal”. By looking at the determination result information 70G, the operator can know whether the joining state of the measurement target is normal or abnormal.

  As described above, the optical nondestructive inspection apparatus and the optical nondestructive inspection method of the present invention use a phase difference between irradiation light (or reflected light) whose intensity changes sinusoidally and radiation infrared rays whose intensity changes sinusoidally. Thus, in the first member and the second member joined to each other at the joining interface, the area of the joining interface can be obtained without destruction.

  As described above, the optical nondestructive inspection apparatus and the optical nondestructive inspection method of the present invention use a phase difference between infrared rays and reflected light (or irradiation light). Therefore, it is not necessary to obtain the absolute temperature (absolute intensity) by the infrared rays radiated from the measurement point SP, and the intensity of the infrared rays changing in a sine wave shape (sinusoidal waveform (amplitude accuracy is not required) due to the change in the infrared ray intensity) Can be detected. Similarly, it is not necessary to obtain the absolute intensity of the reflected light (or irradiation light from the laser output device) reflected at the measurement point SP, and the intensity of the reflected light (or irradiation light) that changes in a sine wave shape (reflected light or It is only necessary to be able to detect a sinusoidal waveform (amplitude accuracy is unnecessary) due to a change in the intensity of irradiation light. Therefore, the area S of the bonding interface can be obtained with high accuracy without being affected by the surface state of the measurement point SP. Therefore, since the generation of errors due to the influence of disturbance can be reduced, the area S of the bonding interface can be obtained with high accuracy.

  The configuration, appearance, etc. of the optical nondestructive inspection apparatus of the present invention and the processing procedure of the optical nondestructive inspection method can be variously changed, added, or deleted without changing the gist of the present invention.

  The optical nondestructive inspection method of the present invention is not limited to the fact that the first member 51 and the second member 52 are metals, and can be applied to substances of various materials. The joining method is not limited to welding, and can be applied to the determination of the area of the joining interface between the first member and the second member joined by various methods.

  Various lasers such as an infrared laser, an ultraviolet laser, and a visible laser can be used as the heating laser.

  In the description of the present embodiment, the example in which the phase difference detection device 60 and the determination device 70 are configured as separate devices has been described. However, the phase difference detection device and the determination device may be integrated.

1, 1A Optical nondestructive inspection device 10 Condensing means (objective lens)
DESCRIPTION OF SYMBOLS 21 Semiconductor laser light source 21A Laser light source 22 Collimating lens 23 Heating laser selective reflection means 24 Acousto-optic modulator 25 Modulation signal output means 27, 27A Laser output device 31 Infrared intensity detection means 32, 42 Condensing lens 41 Laser intensity detection means 51 1st 1 member 52 2nd member 53 bonding interface 60 phase difference detection device 70 determination device 70A physical characteristic information 80 communication line 81 distribution device c1 specific heat capacity of first member d thickness of bonding interface Ks bonding coefficient La heating laser R1 first Thermal resistance of the member R2 Thermal resistance of the second member Rs Bonding interface thermal resistance Rt Thermal resistance of the entire measurement object S Bonding interface area SP Measurement point x Thermal diffusion length αt The first member and the second member were regarded as one member Thermal diffusivity of λ1 Thermal conductivity of the first member λt The first member and the second member were considered as one member Density of Kinonetsu conductivity δ phase difference ρ1 first member

Claims (12)

Information obtained from the measurement point by irradiating a heating laser to the measurement point set on the surface of the first member of the measurement object that is the first member and the second member joined to each other at the joint interface, or An optical nondestructive inspection apparatus for obtaining an area of the bonding interface based on information on the heating laser and information acquired from the measurement point,
A laser output device for emitting the heating laser so that the intensity at the measurement point changes in a sinusoidal shape;
Laser intensity detecting means for detecting the intensity of the heating laser at the measurement point;
Infrared intensity detecting means for detecting the intensity of the infrared rays emitted from the measurement point and changing in a sinusoidal shape,
Taking in the detection signal from the laser intensity detection means and the detection signal from the infrared intensity detection means, the phase difference between the intensity of the heating laser that changes sinusoidally and the intensity of the infrared that changes sinusoidally A phase difference detection device for detecting
A determination device that calculates a bonding interface area that is an area of the bonding interface based on the phase difference captured from the phase difference detection device;
Optical nondestructive inspection device. The optical nondestructive inspection apparatus according to claim 1,
The intensity of the heating laser at the measurement point is
The intensity of the irradiation light that is the heating laser irradiated to the measurement point, and the intensity of the irradiation light that changes sinusoidally, or the intensity of the reflected light of the heating laser reflected at the measurement point And the intensity of the reflected light changing sinusoidally,
Optical nondestructive inspection device. The optical nondestructive inspection apparatus according to claim 1 or 2,
The determination device includes a first physical characteristic that is a physical characteristic of the first member, a second physical characteristic that is a physical characteristic of the second member, and an interface physical characteristic that is a physical characteristic of the bonding interface. Remembered,
The determination device includes:
Thermal diffusivity in which the first member and the second member are regarded as one member based on the phase difference, the frequency of the heating laser whose intensity changes sinusoidally, and the first physical characteristics Seeking
Based on the obtained thermal diffusivity and the first physical characteristics, obtain the thermal conductivity considering the first member and the second member as one member,
The bonding interface which is the thermal resistance of the bonding interface from the obtained thermal conductivity, the apparent thermal resistance of the measurement object based on the phase difference, the first physical characteristic, and the second physical characteristic Find the thermal resistance,
Calculate the bonding interface area based on the determined bonding interface thermal resistance and the interface physical properties,
Optical nondestructive inspection device. The optical nondestructive inspection apparatus according to claim 3,
The determination device is connected to a predetermined communication line, and receives and stores the first physical characteristic, the second physical characteristic, and the interface physical characteristic via the communication line.
Optical nondestructive inspection device. The optical nondestructive inspection apparatus according to claim 3 or 4,
The first physical property, the second physical property, and the interface physical property are:
A thermal diffusion length which is a distance from the measurement point in the first member to a contact surface of the first member and the second member;
Specific heat capacity of the first member;
The density of the first member;
Thermal resistance of the first member;
Thermal resistance of the second member;
A thickness of the bonding interface, or a bonding coefficient relating to the bonding interface area with respect to the bonding interface thermal resistance,
Optical nondestructive inspection device. It is an optical nondestructive inspection device according to any one of claims 1 to 5,
The laser output device is
A semiconductor laser light source that emits a laser whose intensity is modulated based on an input modulation signal, and a modulation signal output unit that outputs the modulation signal.
Alternatively, a laser light source that emits a laser having a predetermined intensity toward the acousto-optic modulator, an acousto-optic modulator that diffracts the incident laser based on the input modulation signal, and a modulation signal that outputs the modulation signal And output means,
Optical nondestructive inspection device. Information obtained from the measurement point by irradiating a heating laser to the measurement point set on the surface of the first member of the measurement object that is the first member and the second member joined to each other at the joint interface, or An optical nondestructive inspection method for obtaining an area of the bonding interface based on information on the heating laser and information acquired from the measurement point,
Using a laser output device, a phase difference detection device, and a determination device,
In the laser output device, a laser emission step of emitting the heating laser so that the intensity at the measurement point changes in a sine wave shape,
In the phase difference detection device, a laser intensity measurement step for measuring the intensity of the heating laser at the measurement point;
In the phase difference detection device, an infrared intensity measurement step of measuring the intensity of the infrared ray that is the intensity of the infrared ray emitted from the measurement point and changes in a sinusoidal shape;
In the phase difference detection device, the phase difference between the intensity of the heating laser that changes in a measured sine wave shape and the intensity of the infrared ray that changes in a measured sine wave shape is obtained, and the obtained phase difference is calculated. A phase difference measuring step for outputting to the determination device;
In the determination device, based on the phase difference, a bonding interface area calculation step of calculating a bonding interface area that is an area of the bonding interface,
Optical nondestructive inspection method. The optical nondestructive inspection method according to claim 7,
The intensity of the heating laser at the measurement point is
The intensity of the irradiation light that is the heating laser irradiated to the measurement point, and the intensity of the irradiation light that changes sinusoidally, or the intensity of the reflected light of the heating laser reflected at the measurement point And the intensity of the reflected light changing sinusoidally,
Optical nondestructive inspection method. The optical nondestructive inspection method according to claim 7 or 8,
The determination device stores a first physical characteristic that is a physical characteristic of the first member, a second physical characteristic that is a physical characteristic of the second member, and an interface physical characteristic that is a physical characteristic of the bonding interface. Aside,
In the bonding interface area calculation step,
In the determination device,
Thermal diffusivity in which the first member and the second member are regarded as one member based on the phase difference, the frequency of the heating laser whose intensity changes sinusoidally, and the first physical characteristics Seeking
Based on the obtained thermal diffusivity and the first physical characteristics, obtain the thermal conductivity considering the first member and the second member as one member,
The bonding interface which is the thermal resistance of the bonding interface from the obtained thermal conductivity, the apparent thermal resistance of the measurement object based on the phase difference, the first physical characteristic, and the second physical characteristic Find the thermal resistance,
Calculate the bonding interface area based on the determined bonding interface thermal resistance and the interface physical properties,
Optical nondestructive inspection method. The optical nondestructive inspection method according to claim 9,
The first physical characteristic, the second physical characteristic, and the interface physical characteristic are distributed via a predetermined communication line and stored in the determination device;
Optical nondestructive inspection method. The optical nondestructive inspection method according to claim 9 or 10,
The first physical property, the second physical property, and the interface physical property are:
A thermal diffusion length which is a distance from the measurement point in the first member to a contact surface of the first member and the second member;
Specific heat capacity of the first member;
The density of the first member;
Thermal resistance of the first member;
Thermal resistance of the second member;
A thickness of the bonding interface, or a bonding coefficient relating to the bonding interface area with respect to the bonding interface thermal resistance,
Optical nondestructive inspection method. The optical nondestructive inspection method according to any one of claims 7 to 11,
As the laser output device,
The laser output device comprising: a semiconductor laser light source that emits a laser whose intensity is modulated based on an input modulation signal; and a modulation signal output unit that outputs the modulation signal;
Alternatively, a laser light source that emits a laser having a predetermined intensity toward the acousto-optic modulator, an acousto-optic modulator that diffracts the incident laser based on the input modulation signal, and a modulation signal that outputs the modulation signal Using the laser output device configured with output means,
Optical nondestructive inspection method.