JP6232760B2 - Optical nondestructive inspection method and optical nondestructive inspection apparatus - Google Patents

Description

  The present invention relates to an optical nondestructive inspection method and an optical nondestructive inspection apparatus.

For example, when an electrode is connected to a semiconductor chip by wire bonding, the electrode and the wire are bonded by various methods, but it is necessary to inspect that the electrode and the wire are appropriately bonded.
Conventionally, the joint portion is enlarged with a microscope or the like, and an operator visually inspects, or a predetermined sample is taken out, the electrode and the wire are broken, and the strength and the like are inspected. As a method of destructive inspection, there are, for example, a method called shearing in which shear stress is applied to a joint and shearing is broken, and a method called pulling in which a wire is pulled and peeled to break.
When the worker visually inspects, a difference due to the skill of the worker or a difference due to fatigue or physical condition occurs even for the same worker, so the reliability of the inspection result is low and the inspection efficiency is also poor.
In addition, if a sample is subjected to a destructive inspection, it cannot be guaranteed that all the objects that were not actually destroyed as a sample (all the remaining samples that were not sampled) are in the same state as the sample that was destroyed.

For example, in Patent Document 1, in order to determine the quality of the bonding state by wire bonding from the area of the bonding portion in a non-contact manner, the target position of the wire is heated with a laser, and a small amount of infrared rays emitted from the heating position Measure the temperature transition until reaching the saturation temperature using a two-wavelength infrared radiation thermometer, determine the numerical value correlated with the bonding area from the temperature transition, and judge the quality from the numerical value. A determination method and a determination apparatus are described.
Further, Patent Document 2 discloses that at the joint between the bonding surface and the wire, the wire is sheared by using a shear tool, the strength thereof is measured, the bonding trace remaining on the bonding surface is photographed, and a predetermined portion of the bonding trace is obtained. A wire bond inspection device and a wire bond inspection method for determining whether or not a bonded state is good based on the area of the wire are disclosed.
Patent Document 3 discloses a method for recognizing the shape of a wire image on an image obtained by imaging an article after wire bonding with an imaging device, and the wire image on the image is rougher than the resolution of the image. A bonding wire shape recognition method is disclosed that recognizes a discrete point sequence at intervals and expresses the shape of the wire image by the discrete point sequence.
In Patent Document 4, an imaging signal obtained by imaging an imaging object is converted into a binarized signal for each pixel by binarization means, and the converted binarized signal and a template registered in a memory are used. In a template matching method for obtaining a similarity based on the number of matched pixels for each corresponding pixel, an enlarged shape template and a reduced shape template are registered in advance for one template. A template matching method is disclosed in which a converted binarized signal is compared with each template, and a similarity is obtained from the number of matched pixels.

JP 2011-191232 A JP 2011-29275 A JP-A-6-323822 JP 63-298488 A

When determining the quality of wire bonding using the heating laser described in Patent Document 1, whether or not the appearance of the bonded wire is a state to be inspected using the heating laser is determined. It is very important to judge. This is because if the appearance of the wire is not clearly in a state to be inspected, the inspection is wasted and the inspection time takes longer than necessary. However, Patent Document 1 does not describe the point of determining whether or not the appearance of the bonded wires is a state in which an inspection using a heating laser is to be performed.
Further, Patent Document 2 is a so-called destructive inspection, and even if the actually destroyed sample is determined to be a non-defective product, all of the objects that were not actually destroyed as a sample (all the remaining samples that were not extracted) It cannot be guaranteed that the sample is in the same state as the destroyed sample.
Further, Patent Document 3 recognizes the shape of the wire after bonding as a discrete point sequence having a coarser spacing than the resolution of the image, but is it in an external state to be inspected using a heating laser? There is no description about the point which determines whether or not.
Further, since Patent Document 4 compares each pixel corresponding to the binarized signal and the template, the comparison takes a very long time, and this template matching method is used to perform inspection using a heating laser. When it is determined whether or not the appearance of the power should be determined, the determination time is expected to be very long, which is not preferable.
The present invention was devised in view of the above points, and the appearance of the measuring object is examined before the temperature rise characteristic is obtained by irradiating the heating laser to inspect the state inside the measuring object. An optical non-destructive inspection method and an optical device capable of more appropriately inspecting whether or not the state should be inspected using a heating laser and capable of performing the inspection in a shorter time It is an object to provide a nondestructive inspection apparatus.

In order to solve the above problems, the optical nondestructive inspection method and the optical nondestructive inspection apparatus according to the present invention take the following means.
First, the first invention of the present invention comprises a heating laser light source that emits a heating laser having a heating laser wavelength set to an output for heating without destroying the measurement object, and at least one that can detect infrared rays. Using the infrared detection means and the control means for controlling the heating laser light source and capturing the detection signal from the infrared detection means, the heating laser light source is controlled from the control means, and the measurement laser light source is placed on the measurement object. A heating laser irradiation step for irradiating a heating laser toward the set measurement spot, and an infrared ray having a predetermined infrared wavelength extracted from the light emitted from the measurement spot by the control means, Detecting using the radiant infrared detection step, the control means, the detection value detected in the radiant infrared detection step, and the heating laser A temperature rise characteristic measuring step for measuring a temperature rise characteristic that is a temperature rise state of the measurement spot according to the heating time based on the heating time that is the irradiation time of the heating laser in the irradiation step; and the control means In the optical nondestructive inspection method, comprising: a determination step for determining a state of the measurement object based on the temperature rise characteristic. The measurement object includes two members, a first member and a second member. It is a junction structure part including the junction part which joined the member.
And using the imaging means, moving means, storage means and the control means, the storage means stores ideal model contour information regarding the contour of the first member of the ideal measurement object, Before executing the heating laser irradiation step, the moving means is controlled from the control means, and the position of the imaging means relative to the measurement object is set to a preset position where the measurement object can be imaged. A moving step of relatively moving, an imaging step of acquiring the image data of the measurement object by controlling the imaging unit from the control unit at a destination, and the control unit from the acquired image data An outline extracting step for extracting the outline of the first member; the outline of the first member extracted by the control means; and the ideal model outline information stored in the storage means. Based on an evaluation step of evaluating the state of appearance of the first member, based on the contour of the first member extracted to the execution.
Then, the control means determines that the appearance state of the first member based on the extracted contour of the first member is a state to be inspected using the heating laser as a result of the evaluation step. In this case, the measurement spot is set on the actual first member, and the heating laser irradiation step, the radiant infrared detection step, the temperature rise characteristic measurement step, and the determination step are executed. determining the internal state of the object to be measured Te.
In the ideal model contour information, a numerical value related to a predetermined location where the ideal contour of the first member can be specified is stored in association with the predetermined location, and in the evaluation step, the control is performed. The appearance of the first member evaluated by the means is the shape of the first member, and the control means extracts a reference position from the extracted outline of the first member, and is based on the extracted reference position. Then, the predetermined part in the extracted contour of the first member is identified, a numerical value related to the part corresponding to the specified predetermined part is obtained, and the obtained numerical value is stored in the storage means. When the numerical value related to the predetermined portion of the contour information is within an allowable range, it is determined that the shape of the first member based on the contour of the first member is a shape to be inspected.
Further, the first member is a linear member, and the vicinity of one end in the longitudinal direction is joined to the second member, and the image data captured in the imaging step includes the first data The one end of the member is imaged, and the reference position is the position of the contour of the one end in the extracted contour of the first member.
In the ideal first member, the second predetermined length that is longer than the first predetermined distance from the one end portion from a position that is separated from the one end portion in the direction along the longitudinal direction by the first predetermined distance. Up to a position separated by a distance is the joint, and in the evaluation step, the first predetermined distance is separated from the reference position in a direction along the longitudinal direction with respect to the extracted outline of the first member. A first imaginary straight line that is substantially orthogonal to the longitudinal direction is set at a position, and a first reference point and a second reference point that are intersections of the outline of the first member and the first imaginary straight line are obtained and extracted. A second imaginary straight line that is substantially orthogonal to the longitudinal direction is set at a position that is separated from the reference position in the direction along the longitudinal direction by the second predetermined distance with respect to the contour of the one member, At the intersection of the contour and the second virtual line A third reference point and a fourth reference point, a numerical value indicating a distance or an angle associated with the predetermined location specified based on the first reference point to the fourth reference point, and the ideal model contour information The shape of the first member based on the contour of the first member is inspected by determining whether the distance or angle obtained by comparing the numerical value related to the predetermined location is within an allowable range. This is an optical nondestructive inspection method for determining whether or not the shape is a power.

In the first invention, before executing the heating laser irradiation step, the moving step, the imaging step, the contour extracting step, and the evaluating step are executed, and the first member based on the contour of the first member in the evaluating step. When it is determined that the appearance state is a state in which an inspection using a heating laser is to be performed, a measurement spot is set on the first member, and the heating laser irradiation step and subsequent steps are executed.
This makes it possible to appropriately determine whether or not the state of the appearance of the measurement object is to be inspected using the heating laser, and thus is not worthy of inspecting using the heating laser. It is possible to eliminate the useless inspection in the state and to perform the inspection time in a shorter time.

In the first invention, the appearance of the first member evaluated in the evaluation step is the shape of the first member, and the method for evaluating the shape of the first member based on the contour of the first member is a comparison. It is not a template matching method that requires a certain amount of time, but whether or not the numerical value related to the predetermined position with respect to the reference position in the contour of the first member is within the allowable range with respect to the numerical value related to the predetermined position of the ideal model contour information. It is a method of determination.
Thereby, it is determined whether or not the shape of the first member based on the contour of the first member is a shape to be inspected using the heating laser in a very short time compared with the template matching method. can do.

In the first invention, the first member is a linear member, and the position of the contour of one end in the contour of the first member is used as the reference position.
As a result, it is possible to set an appropriate reference position easily and in a short time, and it is possible to easily and quickly specify a predetermined location when obtaining related numerical values.

And in 1st invention, the 1st reference point-the 4th reference point used as the predetermined position from a reference position are set as a temporary four corners of a joined part to the outline of the 1st member, and the 1st A numerical value indicating a distance or angle related to a predetermined location specified based on the reference point to the fourth reference point is compared with a numerical value related to a predetermined location in the ideal model contour information.
As a result, it is possible to easily and appropriately specify a predetermined location in a short time, and a numerical value related to the predetermined location is obtained and compared with a numerical value related to the predetermined location of the ideal model contour information. Can be carried out easily and in a short time.

Next, a second invention of the present invention is the optical nondestructive inspection method according to the first invention , wherein when the measurement spot is set on the first member, the joint portion in the first member The position of the center of gravity of a quadrangle having the first reference point to the fourth reference point as vertices on the surface opposite to the surface and facing the imaging means in the imaging step is used as the measurement spot. This is an optical nondestructive inspection method to be set.

In this second invention , when the measurement spot is set by determining that the shape of the first member based on the contour of the first member is the shape to be inspected using the heating laser, the first reference point The position of the center of gravity of a quadrangle having the fourth reference point as a vertex is set as a measurement spot.
As a result, it is possible to appropriately set the measurement spot almost to the center of the joint, and heat generated by the heating laser can be uniformly propagated throughout the joint.

Next, a third invention of the present invention is the optical nondestructive inspection method according to the first invention or the second invention , wherein the measurement spot is on the side of the first member opposite to the joint. Is set to the surface facing the imaging means during the imaging step, and the internal state of the measuring object to be determined is the size of the area of the joint, The storage means includes a lower limit temperature rise characteristic that is a temperature rise characteristic of a sample whose area of the joint between the first member and the second member is an allowable lower limit, and a sample of the sample whose area of the joint is an allowable upper limit. An upper limit temperature rise characteristic that is a temperature rise characteristic is stored, and in the determination step by the control means, the temperature rise characteristic measured in the temperature rise characteristic measurement step, and the storage means are stored in the storage means. The lower temperature limit Rise and determines the whether the upper limit temperature rise characteristic, the area of the junction between the second member and the first member by comparing within the allowable range, an optical non-destructive testing methods.

In the third aspect of the invention , the internal state of the measurement object is the size of the area of the joint, and the lower limit temperature rise characteristic and the upper limit temperature rise characteristic are stored in the storage means.
Then, the control means compares the measured temperature rise characteristic with the lower limit temperature rise characteristic and the upper limit temperature rise characteristic to determine whether or not the area of the joint is within an allowable range.
Thereby, it can be appropriately determined whether or not the bonding portion is in a desired bonding state (desired bonding area).

Next, a fourth invention of the present invention is the optical nondestructive inspection method according to any one of the first to third inventions , wherein an image based on an output signal from the control means is obtained. An optical nondestructive inspection method using displayable display means and causing the display means to display information related to the result of the determination step from the control means.

In the fourth invention , information relating to the result of the determination step is displayed on the display means.
In addition to displaying the quality of the judgment result, for example, the measured temperature rise characteristic, the temperature rise characteristic corresponding to the ideal area, the temperature rise characteristic equivalent to the allowable lower limit area, and the temperature corresponding to the allowable upper limit area By displaying the ascending characteristics in an overlapping manner, the operator can easily recognize not only the pass / fail state but also how much the ideal state deviates from the lower limit side or the upper limit side. It can be used to manage the quality variation.

Next, a fifth invention of the present invention is an optical nondestructive inspection apparatus for carrying out the optical nondestructive inspection method according to any one of the first to fourth inventions , wherein the optical axis The parallel light incident from one side along the line is condensed toward the measurement spot set on the measurement object as a focal position and emitted from the other side, and is emitted and reflected from the measurement spot. The condensing collimating means for converting the light incident from the other side into parallel light along the optical axis and emitting from one side, the heating laser light source, and the heating laser are converted into the condensing collimator. A laser beam guiding means for heating leading to one side of the means, at least one infrared detecting means capable of detecting infrared rays emitted from the measurement spot, and a condensing collimating means emitted from the measurement spot. One A position of the imaging means relative to the object to be measured, radiation infrared light guiding means for guiding infrared light of the predetermined infrared wavelength to the infrared detection means from the parallel light emitted from The moving means, the storage means, the moving means, the imaging means, and the heating laser light source are controlled, and the control means captures the image data and the detection signal from the infrared detecting means. It is an optical nondestructive inspection device.

In the fifth aspect of the present invention , before the state of the measuring object is determined by irradiating the heating laser to determine the temperature rise characteristic, the appearance of the measuring object is inspected using the heating laser ( An optical non-destructive inspection apparatus that can more appropriately determine whether or not it is a state that should be inspected (internal state), and can perform inspection time in a shorter time by eliminating useless inspection Can be realized appropriately.

It is a figure explaining the example of a measurement object, and is a figure explaining the example of the state which joined the wire to the electrode by wire bonding. It is a figure explaining the example of the whole structure of an optical nondestructive inspection apparatus. It is a figure explaining the example of an internal structure of the laser head part of the optical nondestructive inspection apparatus shown in FIG. It is a flowchart explaining the flow of the whole processing procedure of an optical nondestructive inspection method. It is a flowchart explaining the example of the process sequence of the junction shape inspection process in the process sequence of the optical nondestructive inspection method. It is a flowchart explaining the example of the process sequence of the laser irradiation inspection process in the process sequence of the optical nondestructive inspection method. (A) is a schematic perspective view of the wire bonded on the electrode, (B) is a schematic side view of the wire bonded on the electrode, and (C) is a schematic plan view of the wire bonded on the electrode. . (A) is a figure explaining the example which calculates | requires the outline of the extracted wire (1st member), a reference position, a reference point, and a bond width, (B) is the outline of the extracted wire (1st member) It is a figure explaining the example which calculates | requires a wire angle and a wire width. It is a figure explaining the relationship between an infrared wavelength, infrared energy, and temperature. It is a figure explaining the relationship between temperature and the ratio (2 wavelength ratio) of the energy of infrared rays of two different wavelengths. It is a figure explaining the example which accumulated the measured temperature rise characteristic, the minimum temperature rise characteristic, the upper limit temperature rise characteristic, and the ideal temperature rise characteristic. It is a figure explaining the example which displayed the information regarding the determination result of the state of a measuring object on a display means.

EMBODIMENT OF THE INVENTION Below, the form for implementing this invention is demonstrated using drawing.
● [Example of measurement object (Fig. 1)]
An example of the measurement object will be described with reference to FIG.
In FIG. 1A, one end of a wire 93 such as aluminum having a diameter (width) of about several tens [μm] to several hundreds [μm] is bonded to each electrode 92 provided on a substrate 90 by wire bonding. Then, a perspective view of a state in which the other end of the wire 93 is joined to each terminal of the semiconductor chip 94 fixed on the base 91 on the substrate 90 with an adhesive 95 or the like by wire bonding is shown.
FIG. 1B is a view of FIG. 1A viewed from the B direction.
The wire 93 corresponds to the first member, and the electrode 92 corresponds to the second member.

In order to determine whether or not the wire 93 is appropriately bonded to the electrode 92, the area of the bonding portion 96 (the area in the direction parallel to the surface of the electrode 92 facing the wire 93) is within an allowable range. Whether or not the joining state (internal state) is good or bad may be determined.
Therefore, as shown in the enlarged view of the bonding structure portion 97 in FIG. 1B, a measurement spot SP is set on the surface of the wire 93 of the bonding structure portion 97, and the measurement spot SP is irradiated with a heating laser to be heated. . Then, the temperature of the measurement spot SP gradually increases, and heat is propagated from the measurement spot SP to the electrode 92 through the wire 93 and the junction 96. In addition, infrared rays corresponding to the increased temperature are emitted from the junction structure portion 97 including the measurement spot SP.
Further, although the temperature of the measurement spot SP gradually increases, when the temperature reaches a saturation temperature at which the heating amount and the heat radiation amount coincide with each other, the temperature increase stops and becomes a substantially constant temperature even if the heating is continued. Here, since the amount of heat conduction is large when the area of the joint portion 96 is relatively large, the temperature rise according to the heating time is relatively slow and the saturation temperature is relatively low, and the area of the joint portion 96 is relatively small. If it is small, the amount of heat conduction is small (less heat propagates to the electrode 92), so that the temperature rise according to the heating time is relatively steep and the saturation temperature is relatively high.
Therefore, the measurement spot SP is irradiated with a heating laser to measure the temperature rise characteristic as shown in FIG. 11, the area size of the joint portion 96 is obtained based on the temperature rise characteristic, and the obtained area of the joint portion 96 is obtained. It is possible to determine whether the joining state (the state inside the measurement object) is good or not by determining whether or not is within the allowable range.

In the measurement object shown in FIG. 1, the measurement spot SP is set on the wire 93, the infrared energy emitted from the measurement spot SP is detected while the measurement spot SP is heated by the heating laser, and the detected infrared energy is detected. Based on the above, the temperature rise characteristic of the joint structure portion 97 is obtained, and the joining state (internal state) of the joint structure portion 97 can be determined from the obtained temperature rise characteristic.
However, in the inspection of the joint portion of the joint structure portion 97 in which the wire 93 is joined to the electrode 92, depending on the joining state of the wire to the electrode, it may be an apparently defective product without being inspected in appearance. If it is a defective product with a clear external appearance, it takes no time to inspect the internal state of the joint using a heating laser (in terms of external appearance, it is determined to be a defective product). Therefore, in the case of a defective product with a clear appearance, it is preferable not to inspect the internal state of the joint using a heating laser because the inspection time can be further shortened.
In the following description, the external state of the measurement object is inspected using the heating laser before the temperature rise characteristic is obtained by irradiating the heating laser to inspect the internal state of the measurement object. The details of the optical nondestructive inspection method that can determine whether or not the power state should be appropriate and can perform the inspection in a shorter time will be described.

● [Example of the configuration of the optical nondestructive inspection device 1 (FIGS. 2 and 3)]
Before describing the optical nondestructive inspection method, the configuration of the optical nondestructive inspection apparatus 1 used in the optical nondestructive inspection method will be described.
2 shows a perspective view of the overall configuration of the optical nondestructive inspection apparatus 1, and FIG. 3 shows an example of the internal configuration of the laser head unit 73 of the optical nondestructive inspection apparatus 1 shown in FIG. . In each figure, when the X axis, the Y axis, and the Z axis are shown, the X axis, the Y axis, and the Z axis are orthogonal to each other, and the Z axis indicates a direction upward in the vertical direction. The Y axis indicates the horizontal direction.
As shown in FIG. 2, the optical nondestructive inspection apparatus 1 includes a base 70, a support part 71, a laser head part 73, a Z-axis direction moving means 73Z, an imaging means 74, an X-axis direction slide table 75, and an X-axis direction movement. It comprises means 75X, Y-axis direction slide table 76, Y-axis direction moving means 76Y, control means 50, and the like.

A support portion 71 is fixed to the base 70.
The laser head portion 73 is supported so as to be slidable in the Z-axis direction with respect to the support portion 71. Further, the Z-axis direction moving unit 73Z (such as an electric motor equipped with an encoder) moves the position of the laser head unit 73 in the Z-axis direction relative to the support unit 71 based on a control signal from the control unit 50, A detection signal corresponding to the amount of movement is output to the control means 50. The laser head unit 73 is attached with an imaging unit 74 such as a CCD camera.
The X-axis direction slide table 75 is placed on the base 70, and the X-axis direction moving means 75X (such as an electric motor equipped with an encoder) is controlled by the X-axis relative to the base 70 based on a control signal from the control means 50. The X-axis direction position of the direction slide table 75 is relatively moved, and a detection signal corresponding to the amount of movement is output to the control means 50.
The Y-axis direction slide table 76 is placed on the X-axis direction slide table 75, and the Y-axis direction moving means 76Y (such as an electric motor equipped with an encoder) is based on the control signal from the control means 50 in the X-axis direction. The Y-axis direction slide table 76 is moved relative to the slide table 75 in the Y-axis direction, and a detection signal corresponding to the amount of movement is output to the control means 50.
An object to be measured (in the example of FIG. 2, the electrode 90 and the wire bonding structure portion of the substrate 90 and the semiconductor chip 94) is placed on the Y-axis direction slide table 76.
The Z-axis direction moving means 73Z, the X-axis direction moving means 75X, and the Y-axis direction moving means 76Y all correspond to moving means.

The control means 50 is a personal computer, for example, and is connected to a storage means 60 such as a hard disk. In the example of the present embodiment, the control unit 50 includes the storage unit 60, but the storage unit 60 may be provided outside the control unit 50.
Then, the control means 50 outputs a control signal to the Z-axis direction moving means 73Z and takes in a detection signal from the Z-axis direction moving means 73Z, and determines the relative position in the Z-axis direction of the laser head unit 73 with respect to the measurement object. Control.
Further, the control means 50 outputs a control signal to the X-axis direction moving means 75X and takes in a detection signal from the X-axis direction moving means 75X, and determines the relative position in the X-axis direction of the laser head 73 with respect to the measurement object. And a control signal is output to the Y-axis direction moving unit 76Y and a detection signal from the Y-axis direction moving unit 76Y is fetched to control the relative position of the laser head unit 73 in the Y-axis direction with respect to the measurement object.
Further, the control means 50 outputs a control signal to the imaging means 74 to take in the image data of the measurement object, and based on the taken-in image data, the appearance of the measurement object should be inspected using a heating laser. It is determined whether it is in a state. When the control unit 50 determines that the appearance of the measurement object is in a state in which an inspection using a heating laser is to be performed, the control unit 50 outputs a control signal to the laser head unit 73 to irradiate the heating laser, and the laser Based on the detection signal from the head unit 73, the internal state of the measurement object is inspected.
In the optical nondestructive inspection method described in the present embodiment, the measurement spot SP is irradiated with a heating laser using the optical nondestructive inspection apparatus 1 shown in FIGS. Before inspecting, the imaging means 74 first images the measurement object, and when it is determined that the appearance of the measurement object should be inspected using the heating laser, the heating laser is used. To determine the internal state of the measurement object.

Next, details of the internal configuration of the laser head unit 73 will be described with reference to FIG.
The laser head unit 73 includes a condensing collimating unit 10, a heating laser light source 21, a heating laser collimating unit 41, a heating laser selective reflection unit 11A, a first infrared detection unit 31, a first infrared selective reflection unit 12A, The first infrared condensing means 51, the second infrared detecting means 32, the second infrared selective reflection means 13A, the second infrared condensing means 52, and the like.
Note that the internal configuration of the laser head unit 73 is not limited to the configuration shown in FIG. For example, a single infrared detection unit may be provided, a laser light source for reflectance measurement, an optical sensor, and the like may be added to correct the detection value detected by the infrared detection unit based on the reflectance.

The condensing collimating means 10 directs the parallel light incident from one side along its own optical axis (from the upper side in the example of FIG. 3) toward the measurement spot SP set on the measurement object as a focal position. The light is condensed and emitted from the other side (from the lower side in the example of FIG. 3).
Further, the condensing collimating means 10 converts light that is radiated and reflected from the measurement spot SP (which is a focal position) and incident from the other side into parallel light along its own optical axis, and from one side. Exit.
The condensing collimating means 10 can be constituted by a condensing lens that transmits light and refracts it. However, since the condensing collimating means 10 handles light having a plurality of different wavelengths, it is not preferable for a condensing lens that generates chromatic aberration. Therefore, by forming the condensing collimating means with the (aspherical) reflecting mirrors 10A and 10B, the occurrence of chromatic aberration is eliminated, and a wide wavelength band is supported.

The heating laser light source 21 emits a heating laser having a heating laser wavelength (λa) adjusted to an output capable of heating without destroying the measurement object based on a control signal from the control means 50. To do. For example, the heating laser light source 21 is a semiconductor laser.
The heating laser collimating means 41 is disposed in the vicinity of the heating laser light source 21 (near the laser emission position and on the optical axis of the heating laser), and the heating laser light emitted from the heating laser light source 21 is transmitted. Conversion to parallel laser heating laser La. For example, the heating laser collimating means 41 may be a collimating lens because it only needs to convert the light of the heating laser wavelength (λa) into parallel light. If the heating laser light source 21 can emit a parallel heating laser, the heating laser collimating means 41 can be omitted.
The selective reflection means for heating laser 11A is arranged on the optical axis of the condensing collimating means 10, and outputs a heating laser La having a heating laser wavelength (λa) emitted from the heating laser light source 21 and converted into parallel light. Reflected toward one side of the condensing collimating means 10 and parallel to a wavelength different from the heating laser wavelength (λa) emitted and reflected from the measurement spot SP and emitted from one side of the condensing collimating means 10. Transmits light L12. For example, the selective reflection means for heating laser 11A is a dichroic mirror that reflects light having a heating laser wavelength (λa) and transmits light having a wavelength other than the heating laser wavelength (λa).
The heating laser collimating means 41 and the heating laser selective reflection means 11A constitute a heating laser light guiding means. The heating laser light guiding means is a heating laser emitted from the heating laser light source 21. Is converted into parallel light and guided to one side of the condensing collimating means 10.

The first infrared detection means 31 can detect infrared energy emitted from the measurement spot SP. For example, the first infrared detection means 31 is an infrared sensor. The detection signal from the first infrared detecting means 31 is taken into the control means 50.
The first infrared selective reflection means 12A emits parallel light L12 (parallel light having a wavelength different from the heating laser wavelength) emitted from one side of the condensing collimating means 10 and transmitted through the selective reflection means 11A for heating laser. It arrange | positions on a path | route (In this case, it arrange | positions on the optical axis of the condensing collimating means 10). The first infrared selective reflection means 12A is an infrared ray having a first infrared wavelength (λ1) out of the parallel light L12 emitted from one side of the condensing collimating means 10 and transmitted through the selective reflection means 11A for heating laser. The parallel light L1 is reflected toward the first infrared detecting means 31, and the parallel light L13 having a wavelength different from the first infrared wavelength (λ1) is transmitted.
Therefore, the first infrared detecting means 31 detects only infrared energy having the first infrared wavelength (λ1). For example, the first infrared selective reflection means 12A is a dichroic mirror that reflects light having a first infrared wavelength (λ1) and transmits light having a wavelength other than the first infrared wavelength (λ1).
The first infrared condensing means 51 is disposed in the vicinity of the first infrared detecting means 31 (near the detection position) and has the first infrared wavelength (λ1) reflected by the first infrared selective reflecting means 12A. The infrared rays of the parallel light L <b> 1 are collected toward the first infrared detection means 31. For example, the first infrared condensing means 51 may be a condensing lens because it only needs to condense light having the first infrared wavelength (λ1).
The selective reflection means for heating laser 11A, the selective reflection means for first infrared 12A, and the first infrared condensing means 51 constitute a first radiant infrared light guiding means. Infrared light having a first infrared wavelength (λ1) is emitted from the parallel light L12 emitted from the measurement spot SP and emitted from one side of the condensing collimating means 10 and transmitted through the selective reflection means 11A for heating laser. Guide to the infrared detection means 31.

The second infrared detection means 32 can detect infrared energy emitted from the measurement spot SP. For example, the second infrared detection means 32 is an infrared sensor. The detection signal from the second infrared detection means 32 is taken into the control means 50.
The second infrared selective reflection means 13A is emitted from one side of the condensing collimating means 10 and passes through the heating laser selective reflection means 11A and the first infrared selective reflection means 12A (the heating laser wavelength 13A). And parallel light having a wavelength different from the first infrared wavelength) (in this case, the light is disposed on the optical axis of the condensing collimating means 10). The second infrared selective reflection means 13A is output from the parallel light L13 emitted from one side of the condensing collimating means 10 and transmitted through the heating laser selective reflection means 11A and the first infrared selective reflection means 12A. The infrared parallel light L2 having the second infrared wavelength (λ2) is reflected toward the second infrared detection means 32, and the parallel light L14 having a wavelength different from the second infrared wavelength (λ2) is transmitted. In addition, since the transmitted parallel light L14 is unnecessary, it is absorbed by, for example, a light absorber.
Accordingly, the second infrared detecting means 32 detects only the infrared energy having the second infrared wavelength (λ2). For example, the second infrared selective reflection means 13A is a dichroic mirror that reflects light having the second infrared wavelength (λ2) and transmits light having a wavelength other than the second infrared wavelength (λ2).
The second infrared condensing means 52 is disposed in the vicinity of the second infrared detecting means 32 (near the detection position) and has the second infrared wavelength (λ2) reflected by the second infrared selective reflecting means 13A. The infrared rays of the parallel light L <b> 2 are collected toward the second infrared detection means 32. For example, the second infrared condensing means 52 may be a condensing lens because it only needs to condense light having the second infrared wavelength (λ2).
The heating laser selective reflection means 11A, the first infrared selective reflection means 12A, the second infrared selective reflection means 13A, and the second infrared light collecting means 52 constitute a second radiation infrared light guiding means, The second radiant infrared light guiding means is radiated from the measurement spot SP, emitted from one side of the condensing collimating means 10, and transmitted through the heating laser selective reflection means 11A and the first infrared selective reflection means 12A. Infrared light having the second infrared wavelength (λ 2) is guided from the light L 13 to the second infrared detection means 32.

The control means 50 controls the heating laser light source 21 to emit the heating laser La, and the detection signal from the first infrared detecting means 31 and the second infrared detecting means while heating the measurement spot SP with the heating laser. The detection signal from 32 is taken in, and the temperature of the measurement spot SP is measured based on the ratio between the detection value from the first infrared detection means 31 and the detection value from the second infrared detection means 32. The temperature measurement method will be described later.
And the control means 50 measures the temperature rise characteristic which is the temperature rise state of the measurement spot according to heating time, and determines the state inside a measuring object based on the measured temperature rise characteristic.
Details of the operation of the control means 50 will be described later.
The storage means 60 is, for example, a storage device such as a hard disk, and stores data and the like (details will be described later) that support the determination of the state of the joint from the obtained temperature rise characteristics.

The feature of the present application is that the surface of the wire 93 in the joint structure portion 97 is irradiated with a heating laser La to obtain a temperature rise characteristic and the state inside the joint structure portion 97 is inspected before the wire 93 in the joint structure portion 97 is examined. Judgment is made on whether or not the shape of the appearance is an appearance state worthy of inspection of the internal state of the joint structure part, and when it is determined that the internal state is an external state to be inspected, the heating laser is irradiated. Then, the internal state of the joint structure portion is determined. When it is determined that the internal state is not an appearance to be inspected, the inspection for irradiating the heating laser is not performed, so that the useless inspection is not performed. For this reason, the inspection time can be further shortened as much as unnecessary inspection is not performed. Also, as will be described later, each distance and angle is obtained based on the outline of the wire in the image data without using the template matching method to determine whether or not the internal state is the appearance state to be inspected. Thus, it can be determined in a shorter time whether or not the internal state is an appearance state to be inspected.
Hereinafter, an example of a processing procedure by the control unit 50 will be described.

● [Processing procedure of optical nondestructive inspection method (Fig. 4)]
Next, the processing procedure of the optical nondestructive inspection method using the optical nondestructive inspection apparatus 1 shown in FIG. 2 will be described using the flowchart shown in FIG.

For example, when the optical nondestructive inspection apparatus 1 is activated, or when execution of inspection is instructed from the control means 50 of the activated optical nondestructive inspection apparatus 1, the process of the flowchart shown in FIG. 4 is executed. .
In step S10, the control means 50 determines whether the appearance state (shape) of the joint portion (in this case, the joint portion of the wire 93) is a state (shape) to be inspected using the heating laser. The joint shape inspection process (SB100) for determining is performed, and the process proceeds to step S20. The details of the joint shape inspection process will be described later.
In step S20, the control means 50 determines whether or not the shape of the appearance of the joint is a shape to be inspected using the heating laser as a result of the joint shape inspection process in step S10. If it is determined that the shape is an appearance to be inspected using the heating laser (Yes), the process proceeds to step S30, and if it is determined that the shape is not the appearance to be inspected using the heating laser (No). Proceed to step S50.
When the process proceeds to step S50, the control unit 50 displays on the display unit that the appearance of the joint portion is defective (internal state inspection is useless), and ends the process.
When the process proceeds to step S30, the control means 50 uses the heating laser to determine the internal state of the joint (in this case, whether or not the joint area is within an allowable range) (SB200). To proceed to step S40. Details of the laser irradiation inspection process will be described later.
In step S40, the control unit 50 displays information on the result of the laser irradiation inspection process in step S30 on the display unit, and ends the process. A display example will be described later.

● [Joint shape inspection processing procedure (FIGS. 5, 7, 8)]
Next, details of the processing procedure of the joint shape inspection process (SB100) will be described with reference to FIGS. The joint shape inspection process is a process for inspecting the appearance (shape) of the wire at the joint.
In step S110, the control means 50 moves the imaging means relatively above the bonding portion of the wire of the measurement object, and proceeds to step S115. Note that the coordinates of the destination (X, Y, Z) are stored in advance in the storage means, and the control means 50 moves in the X-axis direction so that the imaging means moves to the coordinates read from the storage means. And the Y-axis direction moving means and the Z-axis direction moving means are controlled.
FIGS. 7A to 7C are schematic views of the external shape of the wire joint. 7A shows a perspective view of the periphery of the bond portion 93B that is a joint portion, FIG. 7B shows a side view of the periphery of the bond portion 93B that is a joint portion, and FIG. 7C shows the joint portion. The top view around the bond part 93B which is is shown. Here, a tip portion (one end portion in the longitudinal direction) of the wire 93 that is not joined to the electrode 92 is a tail portion 93T, and a portion where the wire 93 and the electrode 92 are joined is a bond portion 93B. A portion that is neither the tail portion nor the bond portion is defined as a wire portion 93W.
For example, as shown in FIG. 7C, when there are a plurality of wires 93, coordinates corresponding to P (1) at the center of the electrode 92 (1) to which the wires 93 (1) are joined are stored in the storage means. Similarly, the coordinates corresponding to the center P (2) of the electrode 92 (2) to which the wire 93 (2) is bonded, and the center P (3) of the electrode 92 (3) to which the wire 93 (3) is bonded. ) Are stored in the storage means.
For example, when inspecting the appearance shape of the joint portion of the wire 93 (2) in FIG. 7C, the control means 50 reads the coordinates corresponding to P (2) from the storage means, and takes the imaging means to the coordinates. Is moved relatively.
Step S110 corresponds to a moving step of controlling the moving means from the control means to move the position of the imaging means relative to the measuring object to a preset position where the measuring object can be imaged.

In step S115, the control means 50 controls the imaging means to image the measurement object, acquires image data obtained by the imaging from the imaging means, and proceeds to step S120. For example, when the imaging unit moves to the coordinate of P (2) in FIG. 7C, the imaging unit images the area A1 in FIG. 7C and outputs the image data to the control unit 50.
Note that step S115 corresponds to an imaging step of acquiring the image data of the measurement object by controlling the imaging unit from the control unit at the destination.
In step S120, the control means 50 extracts the outline of the wire (first member) from the image data of area A1, and proceeds to step S125.
Step S120 corresponds to a contour extracting step in which the control means extracts the wire contour from the acquired image data.
In step S125, the control means 50 rotates the extracted contour in a predetermined direction, and proceeds to step S130. As shown in FIG. 1, since the wires joined to the electrodes are joined in various directions, they are unified in a preset direction. As shown in FIGS. 8A and 8B, in the present embodiment, the longitudinal direction of the extracted wire is left and right, and the end portion (tail portion 93T) of the wire is on the left side. Then, the extracted contour is rotated.
In step S130, in the state shown in FIG. 8A, the control means 50 extracts the intersection between the right side of the wire outline and the right frame of the image data (the intersection in the example of FIG. 8A). W and V are extracted), and the process proceeds to step S135.
In step S135, the control means 50 determines whether or not the number of intersections obtained in step S130 is two. When the number of intersections is two (Yes), the process proceeds to step S140, and when the number of intersections is not two (No), the process proceeds to step S180B.
When the process proceeds to step S180B, the control means 50 determines that the appearance state of the imaged measurement object (in this case, the wire including the joint portion) is not the appearance state (shape) to be inspected internally, The process ends and the process returns to step S20 in the flowchart shown in FIG.

When the process proceeds to step S140, the control unit 50 extracts the reference position in the image of FIG. 8A which is the extracted wire outline, and the process proceeds to step S145.
As shown in FIGS. 7A to 7C, the wire 93 that is the first member is a linear member, and the vicinity of one end in the longitudinal direction is joined to the electrode 92 that is the second member. Yes.
As shown in FIG. 8A, in the image data obtained by extracting the outline of the wire, one end of the wire is imaged on the left side. And the control means 50 makes the position of the outline of the one end part of this wire the reference position. More specifically, as shown in FIG. 8A, the control unit 50 prepares a virtual straight line MA parallel to the Y axis, and sets the virtual straight line MA at a position in contact with the left end of the extracted wire outline. . The position of this virtual straight line MA is the reference position.
In step S145, the control means 50 sets a virtual straight line MB parallel to the virtual straight line MA at a position separated from the virtual straight line MA that is the reference position by the tail length LT stored in the storage means. A reference point A and a reference point B, which are intersection points of the MB and the wire outline, are obtained. Further, the control means 50 sets a virtual straight line MC parallel to the virtual straight line MB at a position separated from the virtual straight line MB by the bond length LB stored in the storage means, and the intersection of the virtual straight line MC and the wire outline. A reference point C and a reference point D are obtained, and the process proceeds to step S150.
Reference point A to reference point D correspond to the first reference point to the fourth reference point, and are set as temporary four corners of the joint.
The numerical value of the tail length LT and the numerical value of the bond length LB are the ideal length of the tail portion 93T and the ideal length of the bond portion 93B in FIGS. Information is stored in the storage means in association with predetermined locations where the wire outline can be specified (in this case, the boundary portion between the tail portion 93T and the bond portion 93B, and the boundary portion between the bond portion 93B and the wire portion 93W). ing.
The tail length LT corresponds to the first predetermined distance, and the tail length LT + bond length LB corresponds to the second predetermined distance.

In step S150, the control means 50 determines the bond width, which is the width in the bond portion 93B, based on the reference points A to D in the contour image data shown in FIG. 8A and the contour of the bond portion 93B. The process proceeds to step S155A. For example, when obtaining the bond width, the control means 50 obtains the midpoint E of the reference point A and the reference point B, obtains the midpoint F of the reference point C and the reference point D, and is a virtual passing through the midpoint E and the midpoint F. Set straight MD. Then, the control means 50 obtains a plurality of distances DB1 from the virtual straight line MD to the one-side contour (in this case, the upper contour BC) of the bond portion 93B, and sets the maximum distance as the one-side bond maximum width, A plurality of distances DB2 from the MD to the other side contour (in this case, the lower side contour AD) in the bond portion 93B are obtained, and the maximum distance is defined as the maximum bond width on the other side.
In step S155A, control means 50 determines whether or not the maximum bond width on one side (one side) is within an allowable range. The allowable range of the maximum bond width on one side is previously stored in the storage means as a numerical value of the bond width on one side of the ideal bond portion. If it is within the allowable range (Yes), the process proceeds to step S155B. If it is not within the allowable range (No), the process is terminated via step S180B, and the process returns to step S20 of the flowchart shown in FIG.
When the process proceeds to step S155B, the control unit 50 determines whether or not the maximum bond width on the other side (one side) is within an allowable range. The allowable range of the maximum bond width on the other side is stored in advance in the storage means as a numerical value of the bond width on the other side of the ideal bond portion. If it is within the allowable range (Yes), the process proceeds to step S155C. If it is not within the allowable range (No), the process ends via step S180B, and the process returns to step S20 of the flowchart shown in FIG.
When the process proceeds to step S155C, the control means 50 adds the maximum bond width on one side and the maximum bond width on the other side to obtain the bond width (full width), and whether or not the obtained bond width is within the allowable range. Determine. The allowable range of the bond width (full width) is stored in advance in the storage means as a numerical value of the ideal bond width (full width) of the bond portion. When it is within the allowable range (Yes), the process proceeds to step S160. When it is not within the allowable range (No), the process is terminated via step S180B, and the process returns to step S20 of the flowchart shown in FIG.
Thus, the allowable range of the bond width on one side (one side) of the bond portion, the allowable range of the bond width on the other side (one side) of the bond portion, the width on one side and the other side of the bond portion The allowable range of the bond width (full width) obtained by adding is stored as ideal model contour information in the storage means in association with a predetermined portion (in this case, the bond portion) where the wire contour can be specified.

When the process proceeds to step S160, the control unit 50 determines the wire portion 93W of the wire portion 93W based on the reference point C, the reference point D, and the contour of the wire portion 93W in the contour image data shown in FIG. The wire angle that is the angle in the extending direction is obtained, and the process proceeds to step S165. For example, when obtaining the wire angle, the control means 50 sets virtual straight lines ME1 to MEn parallel to the virtual straight line MC at predetermined intervals as shown in FIG. 8B, and each of the virtual straight lines ME1 to MEn and the wire portion 93W. Intersection points HUn and HLn with the contours of the virtual lines ME1 to MEn are obtained. The control means 50 obtains the midpoint Jn of the intersection HUn and the intersection HLn with respect to each of the virtual straight lines ME1 to MEn, and is a virtual straight line passing through the midpoint F (the midpoint of the reference point C and the reference point D). Thus, a virtual straight line MF is set that minimizes the sum of the distances from the middle points J1 to Jn. And the control means 50 calculates | requires the angle ((theta) w) of virtual straight line MF and virtual straight line MC, and makes this angle ((theta) w) the wire angle (theta) w.
In step S165, the control means 50 determines whether or not the obtained wire angle θw is within an allowable range. The allowable range of the wire angle is stored in advance in the storage means as a numerical value of the wire angle of the ideal wire portion. If it is within the allowable range (Yes), the process proceeds to step S170. If it is not within the allowable range (No), the process is terminated via step S180B, and the process returns to step S20 of the flowchart shown in FIG.
When the processing proceeds to step S170, the control means 50 determines the wire that is the width of the wire portion 93W in the wire portion 93W based on the virtual straight line MF in the contour image data shown in FIG. 8B and the contour of the wire portion 93W. The width is obtained and the process proceeds to step S175. For example, when obtaining the wire width, the control unit 50 sets virtual straight lines MG (not shown) orthogonal to the virtual straight lines MF at predetermined intervals, obtains intersections between the virtual straight lines MG and the outlines of the wire portions 93W, The distances between the intersections of the two points on the straight line MG are obtained, and the minimum distance among the obtained distances is defined as the wire width.
In step S175, the control means 50 determines whether or not the wire width is within an allowable range. The allowable range of the wire width is stored in advance in the storage means as a numerical value of the ideal wire width of the wire portion. If it is within the allowable range (Yes), the process proceeds to step S180A. If it is not within the allowable range (No), the process is terminated via step S180B, and the process returns to step S20 of the flowchart shown in FIG.
The numerical value of the allowable range of the wire angle and the numerical value of the allowable range of the wire width are stored in the storage unit as ideal model contour information in association with a predetermined portion (in this case, the wire portion) where the wire contour can be specified. ing.
In steps S130 to S175, the control means evaluates the state of the appearance of the wire based on the extracted wire outline based on the extracted wire outline and the ideal model outline information stored in the storage means. This corresponds to the evaluation step.

When the process proceeds to step S180A, the control means 50 examines the inside of the measurement object for the appearance state (shape) of the measurement object based on the contour of the measurement object (in this case, the wire including the joint). It determines with it being the state (shape) which should be performed, and progresses to step S185.
When the process proceeds to step S180B, as already described, the appearance state (shape) of the measurement object based on the contour of the measurement object (in this case, the wire including the joint) is determined by the measurement object. It is determined that the inside is not in a state (shape) to be inspected, the process is terminated, and the process returns to step S20 in the flowchart shown in FIG.
When the process proceeds to step S185, the control unit 50 sets the position of the center of gravity of the quadrilateral ABCD formed by the reference point A-reference point B-reference point C-reference point D as the measurement spot SP, and ends the process. Then, the process returns to step S20 of the flowchart shown in FIG.
In order to more accurately inspect the internal state of the measurement object, it is necessary to set the position of the measurement spot to an accurate position with respect to each wire. For this purpose, it is necessary to set the position of the measurement spot for each actual wire based on image data obtained by imaging the actual wire. Therefore, since the image data is acquired with great effort, an appearance check is also performed using the image data, and the inspection is performed more efficiently.

● [Laser Irradiation Inspection Processing Procedure (FIGS. 6, 9 to 11)]
Next, the details of the processing procedure of the laser irradiation inspection process (SB200) will be described with reference to FIGS. The laser irradiation inspection process is a process for inspecting the internal state of the joint (the size of the area of the joint).
In step S210, the control means 50 moves the laser head portion relatively above the set measurement spot and proceeds to step S215.
In step S215, the control means 50 controls the heating laser light source 21, starts irradiation of the heating laser toward the set measurement spot, and proceeds to step S220.
The heating laser is guided to the measurement spot, and the infrared rays emitted from the measurement spot are guided to the first infrared detection means and the second infrared detection means. Note that the output of the heating laser in this case is set to an output capable of appropriately measuring the temperature rise characteristic (measured) shown in FIG.
Note that step S215 corresponds to a heating laser irradiation step in which the heating laser light source is controlled from the control means and the heating laser is irradiated toward the measurement spot set on the measurement object.

In step S220, the control means 50 is based on the detection value of the infrared energy of the first infrared wavelength (λ1) based on the detection signal from the first infrared detection means and the detection signal from the second infrared detection means. The detected value of the infrared energy of the second infrared wavelength (λ2) and the time (heating time) after starting the irradiation of the heating laser in step S215 are taken in, and the process proceeds to step S225.
In step S220, the control means transmits infrared rays having predetermined infrared wavelengths (in this case, the first infrared wavelength (λ1) and the second infrared wavelength (λ2)) extracted from the light emitted from the measurement spot, This corresponds to a radiation infrared detection step of detecting using infrared detection means (in this case, first infrared detection means and second infrared detection means).

In step S225, the control means 50 obtains the temperature of the measurement spot corresponding to the heating time based on the ratio between the detection value from the first infrared detection means and the detection value from the second infrared detection means, Proceed to step S230.
In step S225, the control means responds to the heating time based on the detection value detected in the radiation infrared detection step and the heating time that is the irradiation time of the heating laser in the heating laser irradiation step. This corresponds to a temperature rise characteristic measuring step for measuring a temperature rise characteristic that is a temperature rise state of the measurement spot.

For example, FIG. 9 shows the wavelength (horizontal axis) of infrared rays emitted from a black body when the temperature of the black body that completely absorbs and emits irradiated light is each temperature (M1, M2,... M6). The example of the infrared radiation characteristic which shows the relationship of the energy (vertical axis | shaft) of the infrared rays of each wavelength is shown.
For example, when the measurement spot is a black body, the position of the first infrared wavelength (λ1) is the position of (λ1) shown in FIG. 9, and the position of the second infrared wavelength (λ2) is shown in FIG. It is assumed that the position is (λ2).
The control unit 50 detects the infrared energy of the first infrared wavelength (λ1) detected by the first infrared detection unit captured at the timing of the heating time T1 as E1A, and detects it by the second infrared detection unit. When the detected value of the infrared energy of the second infrared wavelength (λ2) is E2A, the ratio of the detected values E1A / E2A and the temperature / two-wavelength ratio characteristic (FIG. 10) “E (λ1) / E ( The temperature of the measurement spot is obtained from the “λ2)” characteristic, and in this case, it is obtained as M5 [° C.]. The two-wavelength ratio is a ratio of energy of two different wavelengths of infrared rays.
Note that the temperature / two-wavelength ratio characteristics shown in the example of FIG. 10 are stored in the storage unit 60 in advance.
By using the ratio of the detection values, the control unit can obtain the correct temperature of the measurement spot without being affected by the reflectance (emissivity) of the measurement spot.
In addition, (E1B, E2B), (E1C, E2C), (E1D, E2D) are taken in at the timings of the heating times T2, T3, T4 (infrared energy of the first infrared wavelength, infrared energy of the second infrared wavelength), respectively. ), It can be seen from the temperature / two-wavelength ratio characteristics that the temperatures of the heating times T2, T3, and T4 are M4, M3, and M2, respectively.
And a control means calculates | requires the temperature rise characteristic shown to the example of FIG. 11 (measured) from the time (equivalent to a heating time) after irradiation start, and the temperature corresponding to the said time.

When the process proceeds to step S230, the control unit 50 determines whether it is the measurement end timing. When it is determined that the calculated temperature has reached the saturation temperature, the control means 50 determines that it is the measurement end timing. For example, the control unit 50 determines that the temperature has reached the saturation temperature when the temperature obtained in the current step S225 is a temperature increase state equal to or lower than a predetermined value with respect to the temperature obtained in the previous step S225. . The saturation temperature is a temperature in a state where the temperature rise characteristic shown in FIG. 11 is equal to or less than a predetermined value and the temperature is substantially constant.
If the control means 50 has reached the saturation temperature and determines that the measurement end timing is reached (Yes), the control unit 50 proceeds to step S235, and if it is determined that the measurement end timing is not reached (No), the control unit 50 returns to step S220. When returning to step S220, it is more preferable to wait for a predetermined time (for example, about 1 ms) before returning, because the temperature can be obtained at predetermined time intervals.

When the process proceeds to step S235, the control means 50 controls the heating laser light source to stop the irradiation of the heating laser, and the process proceeds to step S240.
In step S240, as shown in FIG. 11, the control means 50 determines the internal state of the joint portion of the measurement object based on the temperature obtained in step S225 and the temperature rise characteristic due to the heating time, and performs processing. The process ends and the process returns to step S40 of the flowchart shown in FIG. A detailed example of the determination method will be described below.
For example, the storage unit 60 stores in advance an ideal temperature rise characteristic of a sample whose joint 96 has an ideal size, a lower limit temperature rise characteristic of a sample whose joint 96 has an allowable lower limit, and an area of the joint 96 having an allowable upper limit. The upper limit temperature rise characteristic of the sample is stored in advance. As shown in FIG. 11, the amount of heat conduction to the electrode 92 varies depending on the size of the area of the joint portion 96, so that each temperature rise characteristic varies.
Then, as shown in FIG. 11, when the measured temperature rise characteristic exists between the lower limit temperature rise characteristic and the upper limit temperature rise characteristic, the control means 50 determines that the state of the joint 96 is good, and the measurement is performed. When the temperature rise characteristic deviated from between the lower limit temperature rise characteristic and the upper limit temperature rise characteristic, it is determined that the state of the joint portion 96 is defective.
Although the ideal temperature rise characteristic may be omitted, if there is an ideal temperature rise characteristic, the operator can easily understand how far the measured temperature rise characteristic is from the ideal state to the upper limit side or the lower limit side. So it is more preferable.
Step S240 corresponds to a determination step.
And the control means 50 complete | finishes the process of a laser irradiation test | inspection process (SB200), returns to the flowchart shown in FIG. 4, and progresses to step S40.

● [Example of display on display means (Fig. 12)]
In step S40 in the flowchart shown in FIG. 4, the control unit 50 displays information on the determination result of the laser irradiation inspection process shown in FIG. 6 on the display unit, and ends the process. The display means displays a screen based on an output signal from the control means, and is a monitor, for example.
The example shown in FIG. 12 shows an example in which information related to the determination result of the laser irradiation inspection process is displayed on the screen 50M of the display unit 50G of the control unit 50.
In this example, the determination result is “good”, and the “measured temperature rise characteristic” based on the state inside the joint 96 between the electrode and the wire is between the lower limit temperature rise characteristic and the upper limit temperature rise characteristic. It shows that the ideal temperature rise characteristic is slightly shifted to the lower limit temperature rise characteristic side.
The operator can easily determine that the area of the joint 96 between the electrode and the wire is within an allowable range by looking at the displayed temperature rise characteristics, but the area is slightly shifted to the lower limit side. Therefore, it is easy to adjust the device for bonding electrodes and wires so that the bonding area is slightly larger so that it approaches the ideal area, which is very convenient for quality control. is there.
When the display in step S50 in the flowchart shown in FIG. 4 is performed, the control unit 50 displays, for example, “There is a defect in the appearance of the wire. The execution of the laser irradiation inspection has been stopped” on the screen 50M of the display unit 50G. Is displayed and the process ends.

  Whether or not the appearance state (shape) of the wire including the joint is the appearance state (shape) to be inspected (in the internal state) using a laser by performing the processing procedure described above. (Whether or not it is worth checking with a laser) and the state of the inside of the joint of the measurement object (the area of the joint 96 between the electrode 92 and the wire 93 is within an allowable range) Of course, it is also possible to constitute an optical nondestructive inspection apparatus that determines whether or not a control means is used.

As described above, in the optical nondestructive inspection method described in the present embodiment, the joint shape inspection process (SB100) is performed before the temperature rise characteristic is obtained by irradiating the heating laser to inspect the internal state of the measurement object. ) Is appropriately determined whether or not the appearance state (shape) of the measurement object is the appearance state (shape) to be inspected using the heating laser. When it is determined that the appearance is not to be inspected using the heating laser, the laser irradiation inspection process is not performed, so that unnecessary inspection is not performed and the inspection time can be further shortened.
In the joint shape inspection process (SB100), a simple but reliable determination is made to determine whether a numerical value at a predetermined location is within an allowable range without using a time-consuming template matching method. Thus, the inspection time can be further shortened.

The processing procedure, configuration, structure, appearance, shape, and the like of the optical nondestructive inspection method and optical nondestructive inspection apparatus of the present invention can be variously changed, added, and deleted without changing the gist of the present invention.
The example of the infrared radiation characteristic (FIG. 9) described in the present embodiment and the positions of the first infrared wavelength (λ1) and the second infrared wavelength (λ2) shown in the infrared radiation characteristic are as follows. It is an example and is not limited to this.
Further, the above (≧), the following (≦), the greater (>), the less (<), the expression that there is B between A and C (A <B <C), etc. are included even if they contain an equal sign. It does not have to be.
The numerical values used in the description of the present embodiment are examples, and are not limited to these numerical values.

DESCRIPTION OF SYMBOLS 1 Optical nondestructive inspection apparatus 10 Condensation collimating means 10A, 10B (Aspherical) reflective mirror 11A Heating laser selective reflection means 12A First infrared selective reflection means 13A Second infrared selective reflection means 21 Heating laser light source 31 1 infrared detection means 32 second infrared detection means 41 heating laser collimating means 50 control means 50G display means 51 first infrared light collecting means 52 second infrared light collecting means 60 storage means 70 base 71 support part 73 laser head part 73Z Z axis direction moving means 74 Imaging means 75 X axis direction slide table 75X X axis direction moving means 76 Y axis direction slide table 76Y Y axis direction moving means 90 Substrate 92 Electrode (second member)
93 wire (first member)
96 joint 97 joint structure part AD Reference point (1st reference point-4th reference point)
LB Bond length LT Tail length (first predetermined distance)
MA virtual straight line (reference position)
SP measurement spot θw Wire angle

Claims (5)

A heating laser light source for emitting a heating laser having a heating laser wavelength set to an output for heating without destroying the measurement object;
At least one infrared detection means capable of detecting infrared;
Using the control means for controlling the heating laser light source and taking in a detection signal from the infrared detection means,
A heating laser irradiation step of controlling the heating laser light source from the control means and irradiating a heating laser toward a measurement spot set on a measurement object;
A radiation infrared detection step of detecting infrared rays of a predetermined infrared wavelength extracted from the light emitted from the measurement spot by the control means using the infrared detection means;
The measurement spot according to the heating time based on the detection value detected in the radiation infrared detection step by the control means and the heating time that is the irradiation time of the heating laser in the heating laser irradiation step. A temperature rise characteristic measuring step for measuring a temperature rise characteristic which is a temperature rise state of
In the optical nondestructive inspection method, including a determination step of determining the state of the measurement object based on the temperature rise characteristic in the control means.
The measurement object is a joint structure portion including a joint portion obtained by joining the first member and the second member, which are two members,
Using an imaging means, a moving means, a storage means, and the control means,
In the storage means, ideal model contour information relating to the contour of the first member of the ideal measurement object is stored,
Before executing the heating laser irradiation step, the moving means is controlled from the control means, and the position of the imaging means relative to the measurement object is set to a preset position where the measurement object can be imaged. A moving step for relative movement;
An imaging step of controlling the imaging means from the control means at a destination to obtain image data of the measurement object;
A contour extracting step for extracting the contour of the first member from the acquired image data by the control means;
Based on the extracted contour of the first member based on the extracted contour of the first member based on the extracted contour of the first member and the ideal model contour information stored in the storage means. Performing an evaluation step for evaluating the state;
In the control means, as a result of the evaluation step, it is determined that the appearance state of the first member based on the extracted outline of the first member is a state to be inspected using the heating laser. In the case, the measurement spot is set on the actual first member, and the heating laser irradiation step, the radiation infrared detection step, the temperature rise characteristic measurement step, and the determination step are executed. Determine the internal state of the measurement object ;
In the ideal model contour information, a numerical value related to a predetermined location where the ideal contour of the first member can be specified is stored in association with the predetermined location,
In the evaluation step, the appearance of the first member evaluated by the control means is the shape of the first member, and the control means extracts a reference position from the extracted outline of the first member. The predetermined location in the extracted contour of the first member is identified based on the extracted reference position, a numerical value related to the location corresponding to the specified predetermined location is obtained, and the obtained numerical value is stored in the storage means. The shape of the first member based on the contour of the first member is a shape to be inspected when it is within an allowable range for the numerical value related to the predetermined location of the stored ideal model contour information. And
The first member is a linear member, and the vicinity of one end in the longitudinal direction is joined to the second member,
In the image data imaged in the imaging step, the one end of the first member is imaged,
The reference position is the position of the contour of the one end of the extracted contour of the first member,
In the ideal first member, from a position separated from the one end portion by a first predetermined distance in the direction along the longitudinal direction, from the one end portion by a second predetermined distance longer than the first predetermined distance. The joint is up to a distant position,
In the evaluation step,
A first imaginary straight line that is substantially orthogonal to the longitudinal direction is set at a position that is separated from the reference position in the direction along the longitudinal direction by the first predetermined distance with respect to the extracted outline of the first member, Obtaining a first reference point and a second reference point, which are the intersections of the contour of the first member and the first virtual line,
A second imaginary straight line that is substantially orthogonal to the longitudinal direction is set at a position that is separated from the reference position in the direction along the longitudinal direction by the second predetermined distance with respect to the extracted contour of the first member; Obtaining a third reference point and a fourth reference point, which are the intersections of the contour of the first member and the second virtual line,
The numerical value indicating the distance or angle related to the predetermined location specified based on the first reference point to the fourth reference point and the numerical value related to the predetermined location of the ideal model contour information are obtained by comparison. It is determined whether or not the shape of the first member based on the contour of the first member is a shape to be inspected by determining whether or not the distance or angle is within an allowable range.
Optical nondestructive inspection method. The optical nondestructive inspection method according to claim 1 ,
When setting the measurement spot on the first member, the first surface on the surface of the first member opposite to the joint portion and facing the imaging means during the imaging step . The position of the center of gravity of a quadrangle having the reference point to the fourth reference point as a vertex is set as the measurement spot,
Optical nondestructive inspection method. The optical nondestructive inspection method according to claim 1 or 2 ,
The measurement spot is set on the surface of the first member on the side opposite to the joint portion and facing the imaging unit during the imaging step ,
The internal state of the measurement object to be determined is the size of the area of the joint,
The storage means includes a lower limit temperature rise characteristic that is a temperature rise characteristic of a sample whose area of the joint between the first member and the second member is an allowable lower limit, and a sample of the sample whose area of the joint is an allowable upper limit. The upper temperature rise characteristic that is the temperature rise characteristic is stored,
In the determination step by the control means,
The first member and the second member are compared by comparing the temperature rise characteristic measured in the temperature rise characteristic measurement step with the lower limit temperature rise and the upper limit temperature rise characteristic stored in the storage means. Determining whether the area of the joint is within an allowable range,
Optical nondestructive inspection method. An optical nondestructive inspection method according to any one of claims 1 to 3 ,
Using display means capable of displaying an image based on an output signal from the control means,
From the control means,
Displaying information on the result of the determination step on the display means;
Optical nondestructive inspection method. An optical nondestructive inspection apparatus for carrying out the optical nondestructive inspection method according to any one of claims 1 to 4 ,
Parallel light incident from one side along the optical axis is condensed toward the measurement spot set on the measurement object as a focal position and emitted from the other side, and emitted from the measurement spot and Light collecting collimating means for converting the light reflected and incident from the other side into parallel light along the optical axis and emitting from one side;
The heating laser light source;
A laser guide for heating that guides the laser for heating to one side of the condensing collimator;
At least one infrared detection means capable of detecting infrared radiation emitted from the measurement spot;
A radiant infrared light guiding means for guiding the infrared light of the predetermined infrared wavelength from the parallel light emitted from the measurement spot and emitted from one side of the light collecting collimating means;
The imaging means;
The moving means for moving the position of the imaging means relative to the measurement object;
The storage means;
The control means for controlling the moving means, the imaging means, and the heating laser light source, and capturing the image data and a detection signal from the infrared detection means;
Having
Optical nondestructive inspection device.