Inspection method, inspection device, and method for manufacturing adherend

Abstract

This inspection method is performed by a processor before a step of bonding a first adherend to a second adherend by an adhesive applied to a predetermined region of the first adherend. The inspection method includes steps of: acquiring a plurality of pieces of temperature image data generated by photographing a region in time series by an imaging device; applying analysis processing to the plurality of pieces of temperature image data to generate an analysis image according to a temperature change of the region; and determining whether or not there is an adhesive satisfying a predetermined criterion in the region on the basis of the analysis image.

Description

Inspection method, inspection device, and method for manufacturing bonded object

[0001] The present disclosure relates to an inspection method, an inspection device, and a method for manufacturing a bonded object.

[0002] Patent Document 1 discloses a method for post-weld inspection of a laser weld created by irradiating a laser onto the surface of an object to be inspected. The inspection method of Patent Document 1 includes a first step of using an infrared camera to capture an image of the laser weld that has been cooled to ambient temperature after welding, and detecting the weld area by considering the difference in brightness in the obtained infrared image as an index representing the difference in infrared emissivity of the surface of the object to be inspected, and a second step of determining whether the welding is good or bad based on the brightness value of the infrared image within the weld area.

[0003] Patent No. 4140218

[0004] The technique of Patent Document 1 is a technique for inspecting a laser welded portion after welding has already been completed, and is therefore unable to prevent the occurrence of welding defects.

[0005] The present disclosure provides an inspection method, an inspection device, and a method for manufacturing a bonded article that facilitates preventing the occurrence of defective products.

[0006] An inspection method according to one aspect of the present disclosure is an inspection method performed by a processor before a step of adhering a first adherend to a second adherend with an adhesive applied to a predetermined area of ​​the first adherend, and includes the steps of: acquiring a plurality of temperature image data generated by an imaging device photographing the area in chronological order; performing an analysis process on the plurality of temperature image data to generate an analysis image corresponding to the temperature change in the area; and determining, based on the analysis image, whether or not there is an adhesive in the area that meets predetermined criteria.

[0007] A manufacturing method according to one aspect of the present disclosure is a method for manufacturing an adhesive product, comprising a pre-process and a post-process of adhering a first adherend to a second adherend with an adhesive applied to a predetermined region of the first adherend, wherein the pre-process comprises: acquiring a plurality of temperature image data generated by an imaging device photographing the region in chronological order; performing an analytical process on the plurality of temperature image data to generate an analytical image corresponding to temperature changes in the region; and determining, based on the analytical image, whether or not there is an adhesive satisfying a predetermined criterion within the region; and the post-process comprises, when the processor determines that there is an adhesive satisfying the predetermined criterion within the region, adhering the first adherend to the second adherend with the adhesive to manufacture the adhesive product.

[0008] A manufacturing apparatus according to one aspect of the present disclosure is an inspection apparatus that performs an inspection before a process of adhering a first adherend to a second adherend using an adhesive applied to a predetermined area of ​​the first adherend, and includes an input unit that acquires multiple pieces of temperature image data generated by an imaging device photographing the area in chronological order, and a processor that analyzes the images, wherein the processor performs an analytical process on the multiple pieces of temperature image data to generate an analytical image corresponding to the temperature change in the area, and determines whether or not there is adhesive in the area that meets predetermined criteria based on the analytical image.

[0009] According to the present disclosure, it is possible to more easily prevent the occurrence of defective products.

[0010] Graph showing the change in temperature of the components of a workpiece over time when the workpiece is flash heated. Graph showing the spectrum of a xenon lamp and the transmittance characteristics of glass, a primer, and a urethane adhesive. Flowchart illustrating the operation of the inspection device. Schematic diagram illustrating temperature images. Flowchart illustrating details of the pass / fail judgment process of the first embodiment. Schematic diagram illustrating a difference image. Flowchart illustrating the pass / fail judgment process of the second embodiment. Schematic diagram illustrating a phase image. Flowchart showing a method for manufacturing a bonded object according to the third embodiment.

[0011] Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed description of well-known matters or redundant description of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Note that the inventors provide the accompanying drawings and the following description to enable those skilled in the art to fully understand the present disclosure, and do not intend for them to limit the subject matter described in the claims.

[0012] An inspection system according to an embodiment will be described below with reference to the drawings.

[0013] 1 is a block diagram showing an example configuration of an inspection system 1 according to a first embodiment of the present disclosure. The inspection system 1 includes an inspection device 10, an infrared camera 17, an excitation source 18, a control box 15, a power source 16, and an alarm device 19.

[0014] The inspection system 1 can non-destructively detect the condition of the workpiece 90 by using an active thermography method in which excitation energy is applied to the workpiece 90 to heat it and temperature images are taken while the workpiece 90 is being inspected. For example, the inspection system 1 applies excitation energy to the workpiece 90 using an excitation source 18, and takes temperature images in time series using an infrared camera 17.

[0015] The condition of the workpiece 90 includes information about the structure of the workpiece 90, such as external or internal features and defects. The workpiece 90 includes a substrate 91, which is an example of a first adherend, a primer 92 applied to the surface of the substrate 91, and an adhesive 93 applied to the primer 92. The substrate 91 is, for example, glass. The adhesive 93 is, for example, a urethane-based adhesive. In a post-process performed after inspection by the inspection system 1, the substrate 91 is bonded to a second adherend by the primer 92 and the adhesive 93. The inspection system 1 inspects the condition of the workpiece 90 before bonding, for example, whether the primer 92 and the adhesive 93 have been applied to the substrate 91 without any defects.

[0016] The infrared camera 17 captures a time-series image of an area including at least a portion of the workpiece 90 to generate a plurality of temperature image data. The infrared camera 17 includes an infrared sensor that detects infrared rays having a wavelength of, for example, 3 μm to 15 μm. The frame rate of the infrared camera 17 is, for example, 50 Hz (or 50 fps), but is not limited to this.

[0017] The excitation source 18 is an example of a heating device capable of heating the workpiece 90. The excitation source 18 is, for example, a xenon lamp, a laser light source, a vibrator that generates ultrasound, or a coil that generates electromagnetic induction, but is not limited to these, and may be any energy source capable of radiating energy. The excitation source 18 can perform flash heating (pulse heating) by emitting a flash of light on the workpiece 90, or step heating by heating in steps. The wavelength band of the light emitted by the excitation source 18 may be the same as or different from the wavelength band of infrared light detectable by the infrared camera 17. While two excitation sources 18 are illustrated in FIG. 1 , the number of excitation sources 18 is not limited to this and may be one, or three or more.

[0018] The power supply 16 supplies power to the infrared camera 17 and the excitation source 18. The control box 15 includes a control circuit that controls the power supply 16 based on a control signal from the inspection device 10. The control box 15 may control the light emission method, light emission cycle, light emission time, etc. of the excitation source 18.

[0019] The notification device 19 notifies information to the outside. For example, the notification device 19 is controlled by the inspection device 10, and notifies a user of information indicating the detection result of the state of the workpiece 90. The notification device 19 may include a visual notification device such as a light source such as an LED, a display, or an indicator. The notification device 19 may also include an auditory notification device such as a speaker.

[0020] 2 is a block diagram showing an example of the configuration of the inspection device 10 of Fig. 1. The inspection device 10 includes a processor 11, a storage device 12, and an interface 13.

[0021] The processor 11 is composed of a CPU, an MPU, etc., and controls the entire inspection device 10 by executing various programs stored in the storage device 12. The processor 11 controls the excitation source 18 via the control box 15, etc., to control the start and stop of the heating output of the excitation source 18. The processor 11 also controls the imaging operations of the infrared camera 17, such as the start and stop of imaging. The processor 11 also analyzes temperature image data stored in the storage device 12 and detects the state of the workpiece 90, as will be described later.

[0022] The storage device 12 is a recording medium for recording various information including data and programs necessary to realize the functions of the inspection device 10. The storage device 12 is realized, for example, by a semiconductor storage device such as a flash memory or a solid-state drive (SSD), a magnetic storage device such as a hard disk drive (HDD), or other recording media, either alone or in combination. The storage device 12 is not limited to an internal storage device installed in the same housing as the processor 11, but may also be, for example, an external storage device or a NAS (network-attached storage) type storage device. The storage device 12 may include a volatile memory such as an SRAM or a DRAM.

[0023] The interface 13 connects the inspection device 10 to external devices such as the infrared camera 17, the control box 15, the alarm device 19, and the excitation source 18. The interface 13 may be a communication circuit that performs data communication in accordance with an existing wired communication standard or wireless communication standard.

[0024] The interface 13 is an example of an input unit that connects the inspection device 10 and the infrared camera 17 to input information such as temperature image data from the infrared camera 17 into the inspection device 10. The interface 13 is also an example of an output unit that connects the inspection device 10 to external devices such as the control box 15, the alarm device 19, and the excitation source 18 to output information such as control signals from the processor 11 to the external devices. Such input and output units may be integrated as an input / output interface 13 as shown in FIG. 2, or may be realized as multiple interface circuits.

[0025] [1-2. Operation] [1-2-1. Overall Operation] The operation of the inspection device 10 will be described below. The processor 11 of the inspection device 10 according to this embodiment starts heating the workpiece 90 and controls the excitation source 18 via the control box 15 so as to stop the heating a predetermined time (for example, 60 milliseconds) after the start of heating. The infrared camera 17 starts photographing the workpiece 90 when or before heating starts, and continues photographing until a predetermined period of time has elapsed after heating stops.

[0026] The base material 91, the primer 92, and the adhesive 93 have different thermal property values. As a result, differences occur in the measured values ​​of the temperature change rate during heating (how they heat up) and the temperature change rate after heating is stopped (how they cool down) among the base material 91, the primer 92, and the adhesive 93. Here, the thermal property values ​​are physical property values ​​related to heat, such as thermal conductivity, thermal diffusivity, reflectance, transmittance, and absorptance.

[0027] 3 is a graph showing the change in temperature over time of the components of the workpiece 90 when the workpiece 90 is flash-heated. Because the thermophysical properties of the substrate 91, primer 92, and adhesive 93 are different, differences in the temperatures and temperature change rates of the substrate 91, primer 92, and adhesive 93 appear after heating is stopped, especially immediately after heating is stopped, as shown in FIG. 3. Furthermore, because differences in the temperatures and temperature change rates of the substrate 91, primer 92, and adhesive 93 appear within 0.2 seconds after heating starts (t=0), the inspection device 10 can complete the process described below within several tens of seconds, for example, 0.2 to several seconds, from the start of heating.

[0028] Fig. 4 is a graph showing the spectrum of a xenon lamp, which is an example of excitation source 18, and the transmittance characteristics of glass (an example of substrate 91), a primer 92, and a urethane-based adhesive 93. In the graph of Fig. 4, the vertical axis on the left represents relative intensity, and the spectrum showing the relative intensity of the xenon lamp is shown by a dashed line. In the graph of Fig. 4, the vertical axis on the right represents transmittance, and the transmittance characteristics of glass, the primer 92, and the adhesive 93 are shown by a solid line, a long dashed line, and a dashed dotted line, respectively.

[0029] As shown in the graph of FIG. 4, the transmittance characteristics of the glass, primer 92, and adhesive 93 are different from one another, and therefore, as shown in FIG. 3, differences appear in the temperatures and temperature change rates of the glass, primer 92, and adhesive 93 after heating is stopped, especially immediately thereafter.

[0030] Therefore, by analyzing the temperature image data of the workpiece 90, it is possible to distinguish between the portions of the base material 91, the primer 92, and the adhesive 93 in the temperature image.

[0031] 5 is a flowchart illustrating the operation of the inspection device 10. Each process shown in this flow is executed by the processor 11 of the inspection device 10, for example.

[0032] The processor 11 acquires temperature image data from the infrared camera 17 (S1). The acquired temperature image data is stored in the storage device 12. In step S1, or before step S1, the processor 11 controls the excitation source 18 via the control box 15 to start heating the workpiece 90.

[0033] FIG. 6 is a schematic diagram illustrating a temperature image 30 represented by the temperature image data acquired in step S1. The temperature image 30 in FIG. 6 is a temperature image of a workpiece 90 in which a primer is applied to a glass plate and a urethane adhesive is applied on the primer. In the temperature image 30, the adhesive extends in the left-right direction. A scale placed for measurement is shown above the adhesive on the paper surface of FIG. 6.

[0034] 5, after step S1, the processor 11 executes a quality determination process S2 for determining whether the state of the workpiece 90 is defective. Details of the quality determination process S2 will be described later.

[0035] If the processor 11 determines that there is a defective condition as a result of the pass / fail determination process S2 (Yes in S3), it causes the alarm device 19 to perform an alarm operation (S4). This allows the user to know that there is a defect in the workpiece 90. The alarm operation includes, for example, emitting a warning sound from a speaker or turning on or blinking a light source such as an LED. Alternatively, the processor 11 may display information indicating that there is a poor joint on a display, which is an example of the alarm device 19.

[0036] If it is determined in step S3 that there is no poor condition (No in S3), and after step S4, the processor 11 displays information indicating the analysis results, judgment results, etc. on a display, which is an example of an alarm device 19 (S5).

[0037] Next, the processor 11 stores information indicating the analysis results, the determination results, etc. in the storage device 12 (S6). The information stored in the storage device 12 is used, for example, in a subsequent process to determine whether or not to bond the substrate 91, which is the first adherend, to a second adherend. For example, if the condition of the workpiece 90 is poor, the user may not perform the subsequent process and may reapply the primer 92 and / or adhesive 93 to the substrate 91. The user may remove the primer 92 and / or adhesive 93 from the substrate 91 and reapply new primer 92 and / or adhesive 93.

[0038] As described above, the processor 11 can complete the process (pre-process) of Figure 5 within several tens of seconds, for example, 0.2 to several seconds, from the start of heating. Therefore, the pre-process is completed before the adhesive 93 hardens, and the post-process can be performed to bond the substrate 91 to a second adherend to produce a bonded product. Furthermore, since the pre-processing requires a short heating time (for example, 60 milliseconds) for the workpiece 90 as described above, the temperature of the adhesive 93 is not increased more than necessary, and the pre-process can be completed before the adhesive 93 hardens due to the temperature increase.

[0039] [1-2-2. Pass / Fail Determination Process] FIG. 7 is a flowchart illustrating the details of the pass / fail determination process S2 shown in FIG.

[0040] In FIG. 7, first, the processor 11 determines one of the temperature image data acquired in the temperature image acquisition process S1 as a reference frame (reference temperature image data) (S201).

[0041] The reference frame is, for example, temperature image data generated by photographing the photographed area before the start of heating of the workpiece 90. Alternatively, the reference frame may be temperature image data generated by photographing the photographed area after a sufficient amount of time has passed since heating was stopped. In these cases, the reference frame is temperature image data generated by photographing the photographed area at or near the time when the temperature of the photographed area (workpiece 90) is lowest.

[0042] In another example, the reference frame may be temperature image data (temperature peak image) generated by photographing the photographed area at or immediately before the stopping of heating of the workpiece 90. In this case, the reference frame is temperature image data generated by photographing the photographed area at or near the time when the temperature of the photographed area is the highest.

[0043] After step S201, the processor 11 calculates the difference between each of the plurality of temperature image data acquired in step S1 and the reference frame determined in step S201, thereby generating a plurality of difference images (S202). Fig. 8 is a schematic diagram illustrating an example of the difference image 31.

[0044] When multiple materials with different thermophysical properties are present in the imaging area, differences occur in the measured values, such as the rate of temperature change, during heating and after heating is stopped (see FIG. 3). By using a difference image 31 between the temperature image data acquired during heating or after heating is stopped and the reference frame, the temperature changes of the base material 91, primer 92, and adhesive 93 during heating or after heating is stopped and at the time of imaging of the reference frame can be determined. Therefore, in step S206 described below, the base material 91, primer 92, and adhesive 93 can be accurately detected in the difference image based on the differences in the temperature changes of the base material 91, primer 92, and adhesive 93.

[0045] 8 is an image generated by subtracting the reference frame captured before heating started from the temperature image data captured immediately after heating stopped, the substrate 91, primer 92, and adhesive 93 can be detected more accurately in the difference image because there is less noise compared to when using temperature image data captured during heating, when the temperature changes rapidly.

[0046] 7 , the processor 11 extracts a maximum contrast image having the maximum contrast from the plurality of difference images generated in step S202 (S203). Alternatively, the processor 11 may extract a group of images having contrast equal to or greater than a predetermined threshold, and determine one of the group of images as the maximum contrast image. For example, the processor 11 may determine the difference image 31 in FIG. 8 as the maximum contrast image.

[0047] Next, the processor 11 performs filtering on the maximum contrast image extracted in step S203 (S204). The filtering is, for example, image processing such as local equalization (smoothing) filtering, high-pass filtering, and low-pass filtering. The filtering may include processing for adjusting a tone curve. The processor 11 performs filtering to perform processes such as edge emphasis, shading adjustment, and contrast adjustment.

[0048] Next, the processor 11 performs binarization processing on the image after the filtering processing in step S204 (S205).

[0049] The processor 11 uses the binarized image obtained in step S205 to determine whether the condition of the workpiece 90 is poor (S206).

[0050] In this embodiment, the quality determination process S206 includes distinguishing and detecting the base material 91, the primer 92, and the adhesive 93.

[0051] In order to distinguish and detect three or more materials, the binarization process S205 may be performed multiple times. For example, the processor 11 performs a first binarization process and distinguishes between the base material 91 and the primer 92 using the image that has been subjected to the first binarization process. For example, the processor 11 determines that a black area (e.g., pixel value "0") in the image is the base material 91 and a white area (e.g., pixel value "1") is the primer 92. Thereafter, the processor 11 performs a second binarization process by, for example, increasing the contrast ratio between the primer 92 and the adhesive 93, and distinguishes between the primer 92 and the adhesive 93 using the image that has been subjected to the second binarization process.

[0052] In this embodiment, in the pass / fail determination process S206, if the processor 11 detects that the primer 92 has not been applied, the processor 11 determines that the condition of the workpiece 90 is defective. For example, the processor 11 detects that the primer 92 has not been applied if there is a portion within a predetermined region where the primer 92 has not been applied. Alternatively, the processor 11 detects that the primer 92 has not been applied if the ratio of the area of ​​the portion within a predetermined region where the primer 92 has been applied to the area of ​​the predetermined region is less than a predetermined threshold. Information indicating the predetermined region in the temperature image or the binarized image is stored in advance in, for example, the storage device 12.

[0053] In this embodiment, the area of ​​a certain region is the area of ​​the region that can be measured on an image, and is expressed, for example, by the number of pixels that represent the region.

[0054] In the pass / fail determination process S206, for example, the processor 11 determines whether or not there is adhesive 93 that meets a predetermined criterion within a predetermined region, and if there is no adhesive 93 that meets the predetermined criterion, determines that the condition of the workpiece 90 is defective. For example, if the processor 11 detects that the adhesive 93 is not properly positioned on the primer 92, it determines that the predetermined criterion is not met and that the condition of the workpiece 90 is defective. For example, if the contact area between the primer 92 and the adhesive 93 is less than a predetermined threshold, the processor 11 determines that the condition of the workpiece 90 is defective.

[0055] Alternatively, or in addition to these, the processor 11 determines that the condition of the workpiece 90 is poor if the adhesive 93 is placed in a location where there is no primer 92, for example, directly on the substrate 91. The processor 11 determines that the condition of the workpiece 90 is poor if the ratio of the area of ​​the adhesive 93 placed in a location where there is no primer 92 to the area of ​​the adhesive 93 placed on the primer 92 is equal to or greater than a predetermined threshold.

[0056] Alternatively, or in addition to these, the processor 11 determines that the condition of the workpiece 90 is poor if a predetermined amount or more of voids are detected in the adhesive 93 or between the adhesive 93 and the primer 92. Alternatively, or in addition to these, the processor 11 determines that the condition of the workpiece 90 is poor if a predetermined number or more of scratches or cuts are present in the adhesive 93.

[0057] Alternatively, or in addition to these, the processor 11 determines that the condition of the workpiece 90 is poor if the ratio of the area occupied by the adhesive 93 in a predetermined region to the area of ​​the predetermined region is less than a predetermined threshold. The processor 11 may also determine that the condition of the workpiece 90 is poor if there is even one pixel in a predetermined region on the image where there is no adhesive 93.

[0058] Alternatively, or in addition to these, the processor 11 determines that the condition of the workpiece 90 is poor if the width of the adhesive 93 is less than a predetermined threshold width.

[0059] Alternatively, or in addition, the processor 11 determines that the condition of the workpiece 90 is poor if the ratio of the width of the portion of the specified area occupied by the adhesive 93 to the width of the specified area is less than a predetermined threshold value.

[0060] Instead of step S206, a person such as a user may determine whether the condition of the workpiece 90 is poor based on the image after the binarization process.

[0061] [1-3. Effects, etc.] As described above, the inspection method according to this embodiment is performed by the processor 11 before a subsequent process in which the substrate 91, which is an example of a first adherend, is bonded to a second adherend using adhesive 93 applied to a predetermined region of the substrate 91. This inspection method includes the steps of: acquiring a plurality of temperature image data generated by time-series imaging of the predetermined region using an infrared camera 17, which is an example of an imaging device (S1); analyzing the plurality of temperature image data to generate an analysis image corresponding to temperature changes in the imaged region (S201 to S205); and determining, based on the analysis image, whether or not adhesive 93 that meets predetermined criteria is present in the predetermined region (S206).

[0062] This inspection method makes it possible to determine whether or not there is adhesive 93 that meets a predetermined standard before the subsequent process of bonding the substrate 91 to a second adherend, making it easier to prevent the occurrence of defective products. This improves the yield of bonded products manufactured in the subsequent process, reducing the need to discard components such as the substrate 91. This reduces the manufacturing cost of bonded products.

[0063] The workpiece 90 may further include a primer 92 sandwiched between the base material 91 and the adhesive 93. In this case, the step of determining whether or not the adhesive 93 that meets the predetermined criteria is present in the predetermined region includes detecting whether or not the primer 92 has been applied to the predetermined region based on the analysis image. This configuration makes it possible to detect whether or not the primer 92 has been applied to the predetermined region before the subsequent process, making it easier to prevent the generation of defective products.

[0064] In the above case, when the processor 11 detects that the primer 92 has been applied to a predetermined area, it may measure the contact area between the adhesive 93 and the primer 92, and if the contact area is less than a predetermined threshold, it may determine that the condition of the workpiece 90 is defective. If the contact area is equal to or greater than a predetermined threshold, the processor 11 may determine that the condition of the workpiece 90 is not defective (is a good product). This configuration also makes it easier to prevent the occurrence of defective products.

[0065] The step of determining whether there is adhesive 93 that meets the predetermined criteria may include determining that there is adhesive 93 that meets the predetermined criteria if the ratio of the area occupied by adhesive 93 within the predetermined region to the area of ​​the predetermined region is less than a predetermined threshold.

[0066] The step of detecting the substrate 91 and the adhesive 93 may include detecting the substrate 91 and the adhesive 93 based on a difference between a temperature change of the substrate 91 and a temperature change of the adhesive 93 .

[0067] The step of generating the analysis image may include generating the analysis image based on a difference between each of the plurality of temperature image data and reference temperature image data generated by photographing the photographing area.

[0068] The present inspection method may further include a step of heating the first adherend and the adhesive with an excitation source 18, which is an example of a heating device, while the infrared camera is capturing the image. The reference temperature image data may be information generated by capturing an image of the capture area before heating by the excitation source 18 starts or when heating is stopped.

[0069] This inspection method may include (S4) causing the notification device 19 to notify information indicating the detection results of the base material 91 and the adhesive 93. This allows the user to know the detection results before the subsequent process.

[0070] 2. Second Embodiment In a second embodiment, the processor 11 executes the process of FIG. 5 by executing a pass / fail determination process S2a using a discrete Fourier transform in place of the pass / fail determination process S2 using the differential method.

[0071] 9 , first, the processor 11 acquires an analysis time and a set frequency for the discrete Fourier transform (S211). The analysis time and the set frequency are input, for example, by a user and stored in advance in the storage device 12. The analysis time includes, for example, an analysis start time and an analysis end time. Alternatively, instead of the analysis time, the processor 11 may acquire setting information regarding which frames after the start of imaging (for example, the 11th to 100th frames, or all frames from the 9th frame onward) will be used for analysis.

[0072] Next, the processor 11 determines an analysis start frame (start frame) based on the analysis time acquired in step S211 (S212). The start frame is, for example, temperature image data generated by capturing an image of the imaging area when, immediately after, or immediately before heating is stopped in step S2106. In this case, the start frame is temperature image data (temperature peak image) generated by capturing an image of the imaging area at or near the time when the temperature of the imaging area is highest.

[0073] Next, the processor 11 performs a discrete Fourier transform on the temperature image data captured within the analysis time after capturing the start frame (S213), and extracts a phase image showing the phase characteristics at the set frequency (S214).

[0074] 10 is a schematic diagram illustrating a phase image 32 obtained in step S214. While the phase image 32 in FIG. 10 mainly represents the surface structure of the workpiece 90, the phase image of this embodiment is not limited to this. For example, in the pass / fail determination process S2a, by adjusting the set frequency, it is possible to obtain a phase image that represents the internal structure of the adhesive 93, the application state of the primer 92 below the adhesive 93, and the like.

[0075] Returning to FIG. 9 , the processor 11 performs filtering on the phase image extracted in step S214 (S215). The filtering is, for example, local equalization (smoothing) filtering, high-pass filtering, or low-pass filtering. The filtering may include a process for adjusting a tone curve. The filtering may also include a background removal process. The processor 11 performs filtering to perform processes such as edge enhancement, shading adjustment, and contrast adjustment.

[0076] The processor 11 performs binarization processing on the image that has been subjected to the filtering processing in step S215 (S216).

[0077] The processor 11 uses the binarized image obtained in step S216 to determine whether the condition of the workpiece 90 is defective (S217). The quality determination process S217 may be the same as the quality determination process S206 in FIG.

[0078] [3. Embodiment 3] Fig. 11 is a flowchart showing a method for manufacturing a bonded object according to embodiment 3. The manufacturing method of Fig. 11 includes the temperature image acquisition process S1 and the pass / fail determination process S2 of embodiment 1 as pre-processes (first processes). The manufacturing method of Fig. 11 includes a post-process S301 in which a first adherend and a second adherend are bonded to manufacture a bonded object if the processor determines that there is no condition defect in step S3 as a result of the pass / fail determination process S2 (No in S3). Note that if the processor determines that there is a condition defect in step S3 (No in S3), the flow of Fig. 11 ends without performing the post-process.

[0079] After step S3, steps S4 to S6 in FIG. 5 may be executed.

[0080] The post-process S301 is executed, for example, by controlling a bonding device by the processor 11. Alternatively, the post-process S301 may be executed manually by a user who has confirmed the results of the previous process.

[0081] According to the manufacturing method of this embodiment, it is possible to detect whether the condition of at least one of the substrate 91 and the adhesive 93 is defective before the subsequent process of bonding the substrate 91, which is an example of a first adherend, to a second adherend, and it is therefore possible to easily prevent the generation of defective products. Therefore, the yield of the bonded product manufactured in the subsequent process is improved, and the occurrence of situations where components such as the substrate 91 have to be discarded is reduced. This reduces the manufacturing cost of the bonded product.

[0082] [4. Other Embodiments] As described above, the embodiments have been described as examples of the technology in the present disclosure. However, the technology in the present disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate. Furthermore, it is also possible to combine the components described in the above embodiments to create new embodiments. Therefore, other embodiments will be described below as examples.

[0083] In the first embodiment, an example has been described in which the quality determination process S2 includes the filtering process S204 and the binarization process S205. However, the processor 11 only needs to be able to determine whether the condition of the workpiece 90 is good or bad, and at least one of the filtering process S204 and the binarization process S205 may be omitted.

[0084] Similarly, in the second embodiment, at least one of the filtering process S215 and the binarization process S216 may be omitted.

[0085] In the second embodiment, an example has been described in which a phase image is extracted by performing a discrete Fourier transform on a temperature image, but the present disclosure is not limited to this example. For example, the processor 11 may extract a phase image by performing a Fourier transform instead of a discrete Fourier transform.

[0086] In the second embodiment, an example has been described in which a phase image is extracted by performing a discrete Fourier transform on a temperature image, but what is extracted by the discrete Fourier transform is not limited to a phase image. For example, the processor 11 may extract at least one of an amplitude image showing the amplitude characteristics of the data after the discrete Fourier transform, a real part image showing the real part of the data after the discrete Fourier transform, which is a complex number, an imaginary part image showing the imaginary part, and a phase image.

[0087] 5. Example Aspects The following describes examples of the present disclosure.

[0088] <Aspect 1> An inspection method performed by a processor prior to a step of adhering a first adherend to a second adherend with an adhesive applied to a predetermined region of the first adherend, the inspection method comprising the steps of: acquiring a plurality of temperature image data generated by an imaging device photographing the region in time series; performing an analysis process on the plurality of temperature image data to generate an analysis image corresponding to temperature changes in the region; and determining, based on the analysis image, whether or not the adhesive that satisfies predetermined criteria is present in the region.

[0089] <Aspect 2> The inspection method according to aspect 1, further comprising detecting whether or not a primer has been applied to the region based on the analysis image.

[0090] <Aspect 3> The inspection method according to Aspect 2, wherein the processor, when detecting that a primer has been applied to the region, measures a contact area between the adhesive and the primer, determines that the condition of the first adherend is poor if the contact area is less than a predetermined first threshold, and determines that the condition of the first adherend is not poor if the contact area is equal to or greater than the first threshold.

[0091] Aspect 4: The inspection method according to any one of Aspects 1 to 3, wherein the step of determining whether or not the adhesive satisfies the criterion includes determining that the adhesive does not exist if a ratio of an area of ​​the region occupied by the adhesive to an area of ​​the region is less than a predetermined threshold, or if a width of the adhesive is less than a predetermined threshold width.

[0092] Aspect 5: The inspection method according to any one of Aspects 1 to 4, wherein the step of detecting the first adherend and the adhesive includes detecting the first adherend and the adhesive based on a difference between a temperature change of the first adherend and a temperature change of the adhesive.

[0093] Aspect 6: The inspection method according to any one of Aspects 1 to 5, wherein the step of generating the analysis image includes generating the analysis image based on a difference between each of the plurality of temperature image data and reference temperature image data generated by photographing the region.

[0094] Aspect 7: The inspection method according to Aspect 6, further comprising the step of heating the first adherend and the adhesive with a heating device while the photographing device is photographing, and the reference temperature image data is information generated by photographing the area before heating by the heating device starts or when heating is stopped.

[0095] Aspect 8 The inspection method according to any one of Aspects 1 to 5, wherein the step of generating the analysis image includes performing a discrete Fourier transform or a Fourier transform on the plurality of temperature image data to generate the analysis image.

[0096] <Aspect 9> The inspection method according to aspect 8, wherein the analysis image is a phase image at a predetermined frequency of the plurality of temperature image data that have been subjected to discrete Fourier transform or Fourier transform.

[0097] Aspect 10 The inspection method according to Aspect 1, further comprising causing an alarm device to notify information indicating a detection result of the first adherend and the adhesive.

[0098] Aspect 11: A method for producing a bonded product, comprising: a step of performing the inspection method according to any one of Aspects 1 to 10 as a pre-process; and a step of performing a post-process of producing a bonded product by bonding the first adherend to the second adherend with the adhesive when the processor determines that the adhesive that satisfies a predetermined criterion is present in the region.

[0099] <Aspect 12> An inspection device that performs an inspection prior to a step of bonding a first adherend to a second adherend with an adhesive applied to a predetermined region of the first adherend, the inspection device comprising: an input unit that acquires multiple sets of temperature image data generated by an imaging device photographing the region in time series; and a processor that analyzes the images, wherein the processor performs an analysis process on the multiple sets of temperature image data to generate an analysis image corresponding to a temperature change in the region, and determines whether or not the adhesive that satisfies a predetermined standard is present in the region based on the analysis image.

[0100] The present disclosure is applicable to an inspection method, an inspection device, and a method for manufacturing a bonded object.

[0101] REFERENCE SIGNS LIST 1 Inspection system 10 Inspection device 11 Processor 12 Storage device 13 Interface (input unit) 15 Control box 16 Power supply 17 Infrared camera (photographing device) 18 Excitation source (heating device) 19 Notification device 30 Temperature image 31 Difference image 32 Phase image 90 Workpiece 91 Base material (first adherend) 92 Primer 93 Adhesive

Claims

1. An inspection method performed by a processor prior to a step of adhering a first adherend to a second adherend with an adhesive applied to a specified area of ​​the first adherend, the inspection method comprising the steps of: acquiring a plurality of temperature image data generated by an imaging device photographing the area in chronological order; performing an analysis process on the plurality of temperature image data to generate an analysis image corresponding to the temperature change in the area; and determining, based on the analysis image, whether or not the adhesive that satisfies a specified criterion is present within the area.

2. The inspection method according to claim 1, further comprising detecting whether or not a primer has been applied to said region based on said analysis image.

3. The inspection method of claim 2, wherein when the processor detects that a primer has been applied to the region, it measures the contact area between the adhesive and the primer, and if the contact area is less than a predetermined threshold, it determines that the condition of the first adherend is poor, and if the contact area is equal to or greater than the threshold, it determines that the condition of the first adherend is not poor.

4. The inspection method of claim 1, wherein the step of determining whether or not there is an adhesive that satisfies the criterion includes determining that there is no adhesive that satisfies the criterion if the ratio of the area of ​​the adhesive in the region to the area of ​​the region is less than a predetermined threshold value, or if the width of the adhesive is less than a predetermined threshold width.

5. The inspection method of claim 1, wherein the step of detecting the first adherend and the adhesive includes detecting the first adherend and the adhesive based on a difference between a temperature change of the first adherend and a temperature change of the adhesive.

6. An inspection method as described in claim 1, wherein the step of generating the analysis image includes generating the analysis image based on the difference between each of the plurality of temperature image data and reference temperature image data generated by photographing the area.

7. The inspection method according to claim 6, further comprising a step of heating the first adherend and the adhesive by a heating device while photographing with the photographing device, and the reference temperature image data is information generated by photographing the area before heating by the heating device starts or when heating is stopped.

8. The inspection method according to claim 1, wherein the step of generating the analysis image includes performing a discrete Fourier transform or a Fourier transform on the plurality of temperature image data to generate the analysis image.

9. The inspection method according to claim 8, wherein the analysis image is a phase image at a predetermined frequency of the plurality of temperature image data that have been subjected to a discrete Fourier transform or a Fourier transform.

10. The inspection method according to claim 1, further comprising causing an alarm device to notify information indicating the detection results of the first adherend and the adhesive.

11. A method for manufacturing an adhesive product comprising the steps of: performing an inspection method according to any one of claims 1 to 10 as a pre-process; and, when the processor determines that the adhesive satisfies a predetermined criterion within the region, performing a post-process of bonding the first adherend to the second adherend with the adhesive to manufacture an adhesive product.

12. An inspection device for performing an inspection prior to a process of adhering a first adherend to a second adherend with an adhesive applied to a specified area of ​​the first adherend, the inspection device comprising: an input unit for acquiring multiple pieces of temperature image data generated by an imaging device photographing the area in time series; and a processor for analyzing the images, the processor performing an analysis process on the multiple pieces of temperature image data to generate an analysis image corresponding to temperature changes in the area, and determining whether or not the adhesive that satisfies specified criteria is present in the area based on the analysis image.

Images