Inspection device and inspection method

Abstract

Inspection device and inspection method for easier and more accurate inspection of joint condition [Solution] The inspection device comprises an input unit for acquiring temperature image data and a processor for image processing. The processor acquires a plurality of pre-joining temperature image data generated by an infrared imaging device that photographs the workpiece in a time series before the workpiece is joined in a predetermined joining region. The processor acquires a plurality of post-joining temperature image data. The processor applies a Fourier transform or discrete Fourier transform to the plurality of post-joining temperature image data to generate a phase image showing the phase characteristics of the workpiece. Based on the correspondence between the feature portion of the workpiece on the pre-joining temperature image data shown by at least one of the plurality of pre-joining temperature image data and the feature portion on the post-joining temperature image data shown by the post-joining temperature image data, the processor aligns the joining region information related to the joining region shown by the plurality of pre-joining temperature image data with the phase image.

Description

Technical Field

[0001] The present disclosure relates to an inspection apparatus and an inspection method.

Background Art

[0002] Patent Document 1 discloses a non-destructive inspection method using infrared lock-in thermography for determining the quality of a joint of a lap joint in which dissimilar metal materials are friction stir joined. This non-destructive inspection method determines the quality of the joint by comparing the amount and phase of the acquired infrared rays with a predetermined determination value.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides an inspection apparatus and an inspection method that make it easier to inspect the joint state with higher accuracy.

Means for Solving the Problems

[0005] An inspection apparatus according to an aspect of the present disclosure includes an input unit that acquires temperature image data, and a processor that performs image processing, where the processor acquires, via the input unit, a plurality of pre-joint temperature image data generated by an infrared imaging device by photographing a workpiece in a time series before the workpiece is joined in a predetermined joint region, acquires, via the input unit, a plurality of post-joint temperature image data generated by the infrared imaging device by photographing the workpiece in a time series after the workpiece is joined in the joint region, performs a Fourier transform or a discrete Fourier transform on the plurality of post-joint temperature image data to generate a phase image indicating the phase characteristics of the workpiece, Based on the correspondence between the feature portion of the workpiece on the pre-bonding temperature image shown by at least one of the multiple pre-bonding temperature image data and the feature portion on the post-bonding temperature image shown by the post-bonding temperature image data, the bonding region information relating to the bonding region shown by the multiple pre-bonding temperature image data is aligned with the phase image.

[0006] The inspection method relating to one aspect of this disclosure is: The process involves acquiring multiple pre-bonding temperature image data generated by an infrared imaging device that photographs the workpiece in a time series before it is bonded in a predetermined bonding area, and The process involves acquiring multiple post-bonding temperature image data generated by an infrared imaging device that photographs the workpiece in a time series after the workpiece has been bonded in the bonding region, and A step of generating a phase image showing the phase characteristics of a workpiece by applying a Fourier transform or discrete Fourier transform to multiple post-bonding temperature image data, A step of aligning bonding region information relating to the bonding region shown by multiple pre-bonding temperature image data with a phase image, based on the correspondence between the feature portion of the workpiece shown in the pre-bonding temperature image data shown by at least one of multiple pre-bonding temperature image data and the feature portion of the post-bonding temperature image data shown by the post-bonding temperature image data, Includes.

[0007] The inspection methods relating to other aspects of this disclosure are: The processor provides a step of causing an infrared imaging device to capture images of the workpiece in a time series before the workpiece is bonded in a predetermined bonding area, thereby generating multiple pre-bonding temperature image data. The processor performs the step of joining the workpiece to the joining device, The processor, after the workpiece has been joined in the joining region, causes an infrared imaging device to photograph the workpiece in a time series to generate multiple post-joining temperature image data, The process involves a processor performing a Fourier transform or discrete Fourier transform on multiple post-bonding temperature image data to generate a phase image showing the phase characteristics of the workpiece, The processor aligns the bonding region information relating to the bonding region shown by multiple pre-bonding temperature image data with a phase image, based on the correspondence between the feature portion of the workpiece shown by at least one of the multiple pre-bonding temperature image data and the feature portion of the post-bonding temperature image data shown by the post-bonding temperature image data. Includes. [Effects of the Invention]

[0008] According to this disclosure, it is possible to inspect the bonding state with higher precision. [Brief explanation of the drawing]

[0009] [Figure 1] Block diagram showing an example configuration of the inspection system according to Embodiment 1 of this disclosure. [Figure 2] Exploded perspective view of the workpiece shown in Figure 1. [Figure 3] Plan view of the workpiece shown in Figure 1 [Figure 4] Plan view of the second part of the workpiece shown in Figure 1 [Figure 5] Block diagram showing an example configuration of the inspection device shown in Figure 1. [Figure 6] A schematic diagram illustrating the outline of the inspection method performed by the inspection apparatus according to Embodiment 1. [Figure 7] A flowchart showing an example of the inspection method according to Embodiment 1. [Figure 8] A flowchart showing an example of the pre-bonding temperature image acquisition process in Figure 7. [Figure 9] A flowchart showing an example of the post-joining temperature image acquisition process in Figure 7. [Figure 10] A flowchart showing an example of the phase image acquisition process in Figure 7. [Figure 11] Schematic diagram illustrating a phase image. [Figure 12A] A graph showing the phase distribution in a phase image of a workpiece having a bonded region with a bonding strength of 532N. [Figure 12B]Graph showing the phase distribution in the phase image of a workpiece having a bonding area with a bonding strength of 712 N [Figure 12C] Graph showing the phase distribution in the phase image of a workpiece having a bonding area with a bonding strength of 950 N [Figure 13] Graph showing an example of the correlation between the effective area ratio and the bonding strength [Figure 14] Graph showing an example of the relationship between the phase range and the correlation coefficient [Figure 15] Flowchart showing an example of the effective phase range determination process [Figure 16A] Schematic diagram showing an example of a mask image [Figure 16B] Schematic diagram showing an example of a mask image [Figure 17] Schematic diagram including an image group for explaining the effective phase range determination process [Figure 18] Block diagram showing a configuration example of the inspection system according to Embodiment 2 [Figure 19] Flowchart showing an example of the inspection method according to Embodiment 2 [Figure 20] Schematic diagram for explaining the outline of the inspection method performed by the inspection apparatus according to Embodiment 2 [Figure 21] Block diagram showing a configuration example of the inspection system according to Embodiment 3 [Figure 22A] Schematic diagram showing an example of an overlay image [Figure 22B] Schematic diagram showing an example of an overlay image [Figure 22C] Schematic diagram showing an example of an overlay image [Figure 23] Perspective view exemplifying a support jig according to another embodiment

Embodiments for Carrying Out the Invention

[0010] The embodiments will be described below with reference to the drawings as appropriate. However, unnecessarily detailed explanations may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding by those skilled in the art. The inventors provide the accompanying drawings and the following explanation so that those skilled in the art can fully understand this disclosure, and do not intend to limit the subject matter described in the claims by means of these.

[0011] [1. Embodiment 1] [1-1. Structure] [1-1-1. Configuration of the Inspection System] Figure 1 is a block diagram showing an example configuration of inspection system 1 according to Embodiment 1 of the present disclosure. Inspection system 1 comprises an inspection device 10, an infrared camera 17, an excitation source 18, a control box 15, a power supply 16, and a notification device 19.

[0012] The inspection system 1 non-destructively predicts the bonding state of the workpiece 90 by using an active thermography method that applies excitation energy to the workpiece 90 to be inspected and captures a temperature image. In this embodiment, the inspection system 1 applies excitation energy to the workpiece 90 using an excitation source 18 and captures a time-series temperature image using an infrared camera 17.

[0013] In the example shown in Figure 1, the workpiece 90 is a product obtained by joining a first part 91 and a second part 92 in a joining region 95. For example, the first part 91 may be a transparent material that mainly transmits light irradiated from a light source for welding or welding (e.g., a laser device), and the second part 92 may be an absorbent material that mainly absorbs the light. In this case, the first part 91 and / or the second part 92 are joined in the joining region 95 by the first part 91 and / or the second part 92 which have been melted by the light from the light source. In this embodiment, the inspection system 1 can non-destructively predict the joining state of the first part 91 and the second part 92.

[0014] Figure 2 is an exploded perspective view of the workpiece 90 shown in Figure 1, and Figure 3 is a plan view of the workpiece 90. Figure 4 is a plan view of the second part 92. The second part 92 of the workpiece 90 has a bottomed rectangular tubular shape. As shown in Figures 2 and 4, the top surface 92b of the second part 92 is provided with ribs 92a that protrude in the axial direction. The top of the ribs 92a is joined to the first part 91.

[0015] As shown in Figures 3 and 4, the bottom of the second part 92 is provided with recognition marks 93 for alignment purposes, which will be described later. Although Figures 3 and 4 show four recognition marks 93, the number of recognition marks 93 is not limited to four. Also, although the shape of the recognition marks 93 in Figures 3 and 4 is cross-shaped in plan view, the shape of the recognition marks 93 is not limited to this and may be T-shaped, L-shaped, H-shaped, or a predetermined pattern. The recognition marks 93 are attached, printed, or engraved on the outer surface of the second part 92 that is recognizable in plan view, for example.

[0016] As shown in Figure 2, the first component 91 is provided with an opening 91a. This allows light from the recognition mark 93 to reach the infrared camera 17 through the opening 91a. It is not essential that the opening 91a be open; for example, a sealing material such as glass that can transmit infrared rays may be fitted into the opening 91a to seal the workpiece 90.

[0017] The material of workpiece 90 is, for example, a resin such as polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), or polyamide (PA). Alternatively, the material of workpiece 90 may be a ceramic. The material of workpiece 90 may also be a metal such as cold-rolled steel (SPCC steel) or aluminum. The material of workpiece 90 may also be a new material such as CFRP (carbon fiber reinforced plastic), GFRP (glass fiber reinforced plastic), or CNF (cellulose nanofiber).

[0018] Returning to Figure 1, the other components of the inspection system 1 will be described. The infrared camera 17 is an example of an imaging device that captures images of a shooting area including at least a portion of the workpiece 90 in a time series to generate multiple temperature image data (hereinafter sometimes simply referred to as "temperature images"). The infrared camera 17 generates temperature image data by converting infrared image data into a temperature distribution, but in this specification, the infrared image data before such conversion and the temperature image data after conversion may not be treated in particular distinction. The infrared camera 17 includes, for example, an infrared sensor that detects infrared radiation having a wavelength of 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 thereto.

[0019] 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 light source such as a xenon lamp, a halogen lamp, or a laser light source, but is not limited to these, and can be any energy source capable of radiating energy.

[0020] The excitation source 18 can perform flash heating (pulse heating) by flash emission on the workpiece 90, step heating by heating in a step-like manner, or heating by continuously repeating these methods. 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. Figure 1 shows an example of one excitation source 18, but the number of excitation sources 18 is not limited to this and may be two or more.

[0021] 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 control signals from the inspection device 10. The control box 15 may also control the emission method, emission period, emission time, etc., of the excitation source 18.

[0022] The notification device 19 notifies information to the outside. For example, the notification device 19 is controlled by the inspection device 10 and notifies the user of information indicating the inspection result of the internal state of the workpiece 90. The notification device 19 may include visual notification devices such as light sources such as LEDs, displays, and indicators. The notification device 19 may also include auditory notification devices such as speakers.

[0023] [1-1-2. Configuration of the inspection device] Figure 5 is a block diagram showing an example configuration of the inspection device 10 shown in Figure 1. The inspection device 10 comprises a processor 11, a storage device 12, and an interface 13.

[0024] The processor 11 consists of a CPU, 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, thereby controlling the start and stop of the heating output of the excitation source 18. The processor 11 also controls the shooting operations of the infrared camera 17, such as starting and stopping shooting. Furthermore, as described later, the processor 11 performs analysis processing to inspect the workpiece 90 based on the temperature image data stored in the storage device 12.

[0025] The storage device 12 is a recording medium that stores various information, including programs and data necessary to realize the functions of the inspection device 10. The storage device 12 can be implemented as, for example, a semiconductor storage device such as 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 thereof. The storage device 12 is not limited to an internal storage device installed in the same enclosure as the processor 11, but may also be an external storage device, a NAS (network-attached storage) type storage device, etc. The storage device 12 may also include volatile memory such as RAM.

[0026] Interface 13 enables communication between the inspection device 10 and external devices such as the infrared camera 17, control box 15, notification device 19, and excitation source 18. Interface 13 also includes a communication circuit that performs data communication according to existing wired or wireless communication standards.

[0027] Interface 13 is an example of an input unit that connects the inspection device 10 and the infrared camera 17 in order to input temperature image data from the infrared camera 17 to the inspection device 10. 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, notification device 19, and excitation source 18 in order to output information such as control signals from the processor 11 to these external devices. Such input and output units may be implemented as an integrated interface 13 that serves as both input and output, as shown in Figure 5, or they may be implemented as multiple interface circuits.

[0028] [1-2. Operation] [1-2-1. Overall flow of the testing method] Figure 6 is a schematic diagram illustrating the outline of the inspection method performed by the inspection device 10. Figure 7 is a flowchart showing an example of the inspection method according to this embodiment.

[0029] As shown in Figure 6, the inspection device 10 acquires multiple pre-joining temperature images IMG1 generated by the infrared camera 17 taking time-series photographs of the second part 92 before joining the workpiece 90 (pre-joining temperature image acquisition process S101 in Figure 7).

[0030] Next, the first part 91 and the second part 92 of the workpiece 90 are joined together (S102). The joining is performed, for example, using laser welding technology, in which case the joining process is carried out by a joining device that controls the drive of a laser device, for example.

[0031] As shown in Figure 6, the inspection device 10 acquires multiple post-joining temperature images IMG2 generated by the infrared camera 17 capturing images of the joined workpiece 90 in a time series (post-joining temperature image acquisition process S103 in Figure 7).

[0032] The inspection device 10 applies a discrete Fourier transform or a Fourier transform to the post-bonding temperature image IMG2 and obtains a phase image IMG3 according to the analysis conditions (S104). The phase image IMG3 shows, for example, the phase characteristics at a set frequency of the data after the discrete Fourier transform or Fourier transform.

[0033] Details of the pre-bonding temperature image acquisition process S101, the post-bonding temperature image acquisition process S103, and the phase image acquisition process S104 will be described later.

[0034] The inspection device 10 generates a mask image M based on the pre-bonding temperature image IMG1 (S105). For example, as shown in Figure 6, the processor 11 of the inspection device 10 selects one frame from a plurality of pre-bonding temperature images IMG1. For example, the processor 11 selects the frame with the highest contrast from the plurality of pre-bonding temperature images IMG1. Next, the processor 11 adjusts the contrast of the selected frame, making the part corresponding to the bonding area in the image white (pixel value 1) and the other parts black (pixel value 0) to generate a mask image M, which is then stored in the storage device 12. The mask image M is an example of bonding area information indicating the bonding area of ​​the workpiece 90.

[0035] The phase image IMG3 shows bonding information related to the bonding region 95 of the workpiece 90, so bonding information can be detected by analyzing the phase image IMG3. For example, the processor 11 determines the effective bonding region in the phase image IMG3 where the phase value is within the effective phase range (S107), and generates the effective bonding region image IMG4.

[0036] In this embodiment, the "joining area" is the area of ​​the workpiece 90 that is set as the target for joining. Generally, it is desirable that the entire joining area be joined, but depending on the joining quality, part or all of the joining area may not be joined. Furthermore, the portion of the joining area that is actually joined may include a portion where the joining strength is above a predetermined value and a portion where the joining strength is below a predetermined value. The effective joining area represents the area of ​​the joining area that is expected to satisfy a predetermined quality. The "effective phase range" is determined in advance, for example, by the effective phase range determination process described later, and is stored, for example, in the storage device 12. Technical knowledge regarding how the effective joining area is determined by the phase value will be described later.

[0037] In step S107, the processor 11, for example, performs a binarization process on the phase image IMG3 to generate a binarized image in which pixels in the phase image IMG3 whose phase values ​​are within a predetermined range are set to black (pixel value 0). In the binarization process, pixels whose phase values ​​are outside the predetermined range are set to white (pixel value 1).

[0038] If the mask image M derived from the pre-bonding temperature image IMG1 and the effective bonding area image IMG4 derived from the phase image IMG3 can be accurately aligned and superimposed, it is possible to determine the location of structural features such as bonding defects within the bonding area 95. For example, knowing the location of bonding defects allows the user to determine where re-bonding is necessary or to update the equipment settings for future product bonding.

[0039] However, while the phase image IMG3 may contain information about the internal structure of the workpiece 90, it contains little to no information about its external appearance, including its surface. Therefore, there are few structural features to use as a reference for alignment between the effective bonding region image IMG4 derived from the phase image IMG3 and the mask image M. Furthermore, there is a time gap between the time the pre-bonding temperature image IMG1 was captured and the time the post-bonding temperature image IMG2, which is the source of the phase image IMG3, was captured, resulting in differences in the shooting conditions of the two. Consequently, if we assume that the shooting conditions, such as the optical axis of the infrared camera 17, are the same at the time of both images' capture, it becomes impossible to accurately align the effective bonding region image IMG4 and the mask image M.

[0040] Therefore, the inspection device 10 accurately aligns the mask image M and the effective bonding region image IMG4 by utilizing the fact that both the pre-bonding temperature image IMG1 and the post-bonding temperature image IMG2 can be precisely aligned because they both contain information about the recognition mark 93, and that the post-bonding temperature image IMG2 and the phase image IMG3 can be precisely aligned because they share the same optical axis.

[0041] Specifically, as shown in Figure 6, the inspection device 10 acquires alignment information to align one frame from the pre-bonding temperature image IMG1 with one frame from the post-bonding temperature image IMG2 (S106 in Figure 7). When acquiring the alignment information, the information of the recognition marks 93 that appear in each of the two frames is used.

[0042] By using the alignment information obtained in this way, the mask image M derived from the pre-bonding temperature image IMG1 and the effective bonding region image IMG4 derived from the phase image IMG3 can be accurately aligned and superimposed (S108 in Figure 7). For example, in step S108, the processor 11 obtains a logical AND of the pixel value of the mask image M and the pixel value of the effective bonding region image IMG4 for each pixel, and sets the obtained logical AND as the pixel value of the corresponding pixel in the superimposed image.

[0043] Alternatively, the processor 11 may align and superimpose the mask image M, the post-bonding temperature image IMG2, and the effective bonding region image IMG4, and then delete the post-bonding temperature image IMG2. This method also yields a superimposed image in which the mask image M and the effective bonding region image IMG4 are superimposed.

[0044] As shown in Figure 7, the inspection device 10 determines whether or not there is a bonding defect based on the superimposed image 51 obtained in step S108 (S109). For example, the processor 11 of the inspection device 10 determines that there is a bonding defect if, in the superimposed image 51, there is at least one pixel in the bonding region that is not part of the effective bonding region, i.e., a white pixel (a pixel with a pixel value of 1). Alternatively, the processor 11 of the inspection device 10 may determine that there is a bonding defect if, in the effective bonding region image, the number of white pixels present within the bonding region is greater than or equal to a predetermined value.

[0045] If a faulty connection is detected (Yes in S109), the inspection device 10 causes the notification device 19 to perform a notification operation (S110). This allows the user to know that there is a faulty connection. The notification operation includes, for example, emitting a warning sound from a speaker or turning on or flashing a light source such as an LED.

[0046] The inspection device 10 may display information indicating the analysis results, such as the bonding status and judgment results, as well as an overlay image 51, on a display, which is an example of a notification device 19 (S111).

[0047] In this embodiment, the mask image M is generated based on the pre-bonding temperature image IMG1, rather than on an ideal shape such as a drawing or design information (S105). In particular, when the size of the workpiece 90 is small, there may be a difference between the ideal shape shown in the drawing and the actual shape of the workpiece 90, which includes variations. In this embodiment, by generating a mask image M representing the bonding area based on the pre-bonding temperature image IMG1, information about the bonding area corresponding to the actual shape of the workpiece 90 can be obtained. This leads to the accurate detection of bonding defects in the bonding area.

[0048] [1-2-2. Image Acquisition Process] The following describes in detail the pre-bonding temperature image acquisition process S101, the post-bonding temperature image acquisition process S103, and the phase image acquisition process S104 shown in Figure 7. Figures 8 to 10 are flowcharts showing examples of the pre-bonding temperature image acquisition process S101, the post-bonding temperature image acquisition process S103, and the phase image acquisition process S104 shown in Figure 7, respectively.

[0049] As shown in Figure 8, in the pre-bonding temperature image acquisition process S101, the processor 11 of the inspection device 10 acquires setting conditions related to image acquisition (S1). The setting conditions include, for example, heating conditions such as the heating time of the workpiece 90 by the excitation source 18, and shooting conditions such as the shooting time of the workpiece 90 by the infrared camera 17. The setting conditions are input by, for example, the user and stored in advance in the storage device 12.

[0050] Next, the processor 11 starts heating the second component 92 after bonding and taking images of the second component 92 with the infrared camera 17 (S2). Next, the processor 11 acquires multiple post-bonding temperature images generated by the infrared camera 17 taking images of the second component 92 after bonding in a time series via the interface 13 (S3).

[0051] As shown in Figure 9, in the post-bonding temperature image acquisition process S103, the processor 11 acquires the setting conditions for image acquisition (S11). The setting conditions may be the same as or different from the conditions set in step S1 of the pre-bonding temperature image acquisition process S101. The processor 11 starts heating the bonded workpiece 90 and taking images of the workpiece 90 with the infrared camera 17 (S12). Next, the processor 11 acquires multiple post-bonding temperature images generated by the infrared camera 17 taking time-series images of the bonded workpiece 90 via the interface 13 (S13).

[0052] As shown in Figure 10, in the phase image acquisition process S104, the processor 11 of the inspection device 10 first acquires the analysis conditions (S21). The analysis conditions are pre-stored in, for example, the storage device 12. The analysis conditions are parameters such as the effective phase range, analysis time, and set frequency for the phase image. The analysis time includes, for example, the analysis start time and analysis end time. Alternatively, instead of acquiring the analysis time, the processor 11 may acquire a setting on which temperature image (frame) from among the multiple post-joining temperature images generated by the infrared camera 17 will be used for analysis.

[0053] Next, the processor 11 applies a discrete Fourier transform or a Fourier transform to the multiple post-junction temperature images acquired in step S103 to obtain a phase image according to the analysis conditions (S22).

[0054] Figure 11 is a schematic diagram illustrating a phase image IMG3. The phase image IMG3 in Figure 11 is a phase image relating to a tubular workpiece 90, which is set such that the bonding region extends in an annular shape and the cross-section of the bonding portion perpendicular to the direction of extension is circular. In the phase image IMG3 in Figure 11, the phase value of each pixel is shown in grayscale. That is, as shown in the scale on the right side of Figure 11, in the phase image IMG3, pixels with a phase value of 20.0° are shown in black, pixels with a phase value of 10.0° are shown in white, and pixels with a phase value greater than 10.0° and less than 20.0° are shown in gray.

[0055] Returning to Figure 10, the processor 11 applies filtering to the phase image extracted in step S23 (S24). Filtering is an image processing method such as local equalization (smoothing), high-pass filtering, or low-pass filtering. Filtering may also include tone curve adjustment. Through filtering, the processor 11 performs processing such as edge enhancement, grayscale adjustment, and contrast adjustment.

[0056] [1-2-3. Effective Phase Range Determination Process] The effective phase range and the process for determining it are described below.

[0057] The inventors found a correlation between the phase value and the bonding state, such as bonding strength, in the phase image of the bonding region of the workpiece 90. As an example, the inventors found that in the phase image IMG3 shown in Figure 11, the lower the phase value, the greater the bonding strength in the corresponding bonding region and the better the bonding state. The example in Figure 11 shows that a lower phase value indicates that heat is easily transferred, and a higher phase value indicates that heat is not easily transferred. Therefore, the example in Figure 11 shows that the bonding strength is greater in regions where heat is easily transferred.

[0058] Figures 12A, 12B, and 12C are graphs showing that lower phase values ​​correspond to greater bonding strength. Figures 12A to 12C are graphs showing the phase distribution in phase images of workpiece 90 having bonded regions with bonding strengths of 532N, 712N, and 950N, respectively. In the graphs of Figures 12A to 12C, the horizontal axis represents the phase value, and the vertical axis represents the normalized frequency. The bonding strengths shown in Figures 12A to 12C were obtained by taking phase images of workpiece 90 and then measuring them by performing known bonding strength tests on workpiece 90.

[0059] Comparing the graphs in Figures 12A to 12C, it can be seen that the greater the bonding strength, the higher the frequency of pixels with a phase value of 12° or less in the phase image. Based on this finding, the inventor came up with the technical idea of ​​predicting bonding conditions such as bonding strength based on the effective area ratio, which is an example of the proportion of pixels whose phase value is within the effective phase range (12° or less in the example of Figures 12A to 12C).

[0060] Figure 13 is a graph showing an example of the correlation between effective area ratio and bonding strength. In the graph of Figure 13, the effective area ratio is the ratio (percentage) of the number of pixels whose phase value is within the effective phase range to the total number of pixels in the bonding region of the phase image. In this example, the effective phase range is 12° or less. In this graph, the correlation coefficient r between effective area ratio and bonding strength is 0.98, indicating a strong correlation between effective area ratio and bonding strength.

[0061] Furthermore, the inventors discovered that the effective phase range can change depending on the analysis conditions, and devised the effective phase range determination process described later for searching for the effective phase range.

[0062] Figures 12A to 12C illustrate the results when the upper limit of the phase value is 12°, but the correlation coefficient can change by changing the phase range. Figure 14 is a graph showing an example of the relationship between the phase range and the correlation coefficient. The horizontal axis in Figure 14 represents the phase range. When the horizontal axis in Figure 14 is 12°, the correlation coefficient on the vertical axis represents the correlation coefficient between the effective area ratio and the bonding strength, calculated by counting pixels with a phase value of 12° or less.

[0063] Thus, as an example, the correlation coefficient between the effective area ratio and joint strength depends on the upper limit of the phase value. More generally, the correlation coefficient between the effective area ratio and joint strength depends on the range of the phase value, for example, the upper and lower limits of the phase value.

[0064] Therefore, when determining the effective bonding region, applying an effective phase range that results in a large correlation coefficient (e.g., 12° or less) allows for particularly accurate prediction of the bonding state of the workpiece 90. The following describes the effective phase range determination process for searching for the phase range in which the correlation coefficient is greater than or equal to a threshold, for example, the largest possible range.

[0065] Figure 15 is a flowchart illustrating an example of the effective phase range determination process. The process in Figure 15 is performed, for example, by the processor 11 of the inspection device 10, and the determined effective phase range is stored in the storage device 12. Alternatively, the process in Figure 15 may be performed by another information processing device. The following describes an example mainly involving the processor 11.

[0066] First, the processor 11 performs a phase image acquisition process S104 (see Figure 10) on the sample. The sample is a manufactured product of the same type as the workpiece 90 and has a bonding region similar to that of the workpiece 90.

[0067] The processor 11 acquires junction area mask information (S31). Mask information is information that indicates the portion of the phase image corresponding to the junction area of ​​the sample. Mask information is determined based on drawings and design information and stored, for example, in the storage device 12. An example of mask information is a mask image in which pixels corresponding to the junction area of ​​the phase image are set to white (pixel value 1) and other pixels to black (pixel value 0), as shown in Figures 16A and 16B. Figure 16A illustrates a mask image M1 for a sample having an annular junction area in plan view, and Figure 16B illustrates a mask image M2 for a sample having a rectangular junction area in plan view.

[0068] If mask information is not pre-stored in the storage device 12, the processor 11 may generate mask information based on the phase image.

[0069] Referring to Figure 17, an example of the process for generating such a mask image M3 will be explained. The processor 11 segments the portion of the phase image IMG3 corresponding to the joining region to generate a segment image 32. Next, the processor 11 sets the portion of the segment image 32 corresponding to the joining region to white (pixel value 1) and the other portions to black (pixel value 0) to generate a mask image M3. The processor 11 stores the generated mask image M3 in the storage device 12.

[0070] Returning to Figure 15, the processor 11 calculates the area of ​​the junction region from the junction region mask information obtained in step S31 (S32). For example, the processor 11 calculates the area of ​​the junction region as the number of white pixels in the mask image M3.

[0071] Next, the processor 11 generates a joined region image 33 by excluding the areas other than the joined region from the phase image (S33). For example, as shown in Figure 17, the processor 11 generates the joined region image 33 by making the parts of the segment image 32 other than the joined region black (pixel value 0). Alternatively, the processor 11 may generate the joined region image 33 by applying a masking process to the phase image IMG3 using a mask image M3.

[0072] Next, the processor 11 obtains a pre-set phase search range. In the illustrated example, the processor 11 obtains the minimum value Ni and the maximum value Ne of the phase value to be searched (S34). The minimum value Ni and the maximum value Ne are stored in the memory device 12 in advance, for example. In this embodiment, the processor searches for the phase range (effective phase range) that has the largest correlation coefficient between the minimum value Ni and the maximum value Ne. At that time, the processor 11 divides the phase range between the minimum value Ni and the maximum value Ne into n steps (n is an integer of 2 or more) and calculates the correlation coefficient in each step. The number of steps n is also stored in the memory device 12 in advance and is obtained by the processor 11 in step S34.

[0073] Processor 11 initializes the variable k (where k is a non-negative integer) to 0 for the phase search (S35), and sets the current phase value N to Ni + (Ne - Ni)k / n (S36). When k is at its initial value (0), N = Ni.

[0074] The processor 11 performs a binarization process on the junction region image 33 and generates an effective junction region image 34 in which pixels in the junction region image 33 whose phase values ​​are within a predetermined range (Ni or more and N or less) are set to white (pixel value 1) (S37). The effective junction region image 34 is an image that shows the effective junction region.

[0075] Next, the processor 11 calculates the number of white pixels in the effective junction region image 34 as the area of ​​the effective junction region (S38).

[0076] The processor 11 calculates the ratio of the area of ​​the effective bonding area to the area of ​​the bonding area as the effective area ratio (S39). For example, the processor 11 calculates the effective area ratio (A1 / A2) by dividing the area of ​​the effective bonding area (A1) calculated in step S38 by the area of ​​the bonding area (A2) calculated in step S32.

[0077] The processor 11 searches for the effective phase range within the search range by repeating the processes in steps S36 to S39. Specifically, for example, after executing the processes in steps S36 to S39, the processor 11 determines whether the N determined in step S36 is equal to Ne (S40). If N is not equal to Ne (No in S40), the processor 11 increments k (S41) and executes the processes in steps S36 to S40.

[0078] If N=Ne in step S40 (Yes in S40), proceed to step S42.

[0079] In step S42, the processor 11 obtains the bonding strength of the sample (S42). The bonding strength is measured, for example, by a peel test.

[0080] The processor 11 records the effective area ratio calculated in step S39 and the bonding strength obtained in step S42 in the storage device 12, linking them together.

[0081] The above process is performed until the number of data points (number of samples) reaches a predetermined number (S44, S45). The predetermined number is determined in advance by the user or other relevant party. For example, if the number of data points is insufficient (No in S44), the sample is replaced (S45), and steps S1, S31-S44 are performed on the replaced sample. The replaced sample is the same type of sample with the same structure as the original sample.

[0082] When the number of data points reaches a predetermined number (Yes in S44), the processor 11 calculates the correlation coefficient between the effective area ratio and the bonding strength for each phase range based on the data recorded in step S43 (S46). This yields a graph showing the relationship between the phase range and the correlation coefficient, as shown in Figure 14.

[0083] Based on the result of step S46, the processor 11 determines an effective phase range in which the correlation coefficient between the effective area ratio and the bonding strength is greater than or equal to a threshold (S47). The determined effective phase range is used in step S107 of Figure 7 to determine the effective bonding region.

[0084] [1-3. Effects, etc.] As described above, the inspection apparatus 10 according to this embodiment includes an interface 13, which is an example of an input unit for acquiring temperature image data, and a processor 11 for performing image processing. The processor 11 acquires a plurality of pre-bonding temperature image data via the interface 13 (S101). The plurality of pre-bonding temperature image data is data generated by an infrared camera 17, which is an example of an infrared imaging device, capturing images of the workpiece 90 in a time series before the workpiece 90 is bonded in a predetermined bonding region. The processor 11 acquires a plurality of post-bonding temperature image data generated by the infrared camera 17 capturing images of the workpiece 90 in a time series after the workpiece 90 has been bonded in the bonding region, via the interface 13 (S103). The processor 11 applies a Fourier transform or discrete Fourier transform to the plurality of post-bonding temperature image data to generate a phase image showing the phase characteristics of the workpiece 90 (S104). The processor 11 aligns the bonding region information relating to the bonding region shown by the multiple pre-bonding temperature image data with the phase image, based on the correspondence between the feature portion of the workpiece 90 on the pre-bonding temperature image shown by at least one of the multiple pre-bonding temperature image data and the feature portion on the post-bonding temperature image shown by the post-bonding temperature image data.

[0085] According to this embodiment, the inspection device 10 can accurately align the bonding area information with the phase image. This makes it easier to inspect the bonding state of the workpiece 90 with higher precision.

[0086] In this embodiment, the processor 11 may generate a mask image M by performing a binarization process on one of the multiple pre-junction temperature image data to distinguish between the junction region and other regions (S105).

[0087] In this embodiment, the processor 11 may generate a superimposed image 51 by superimposing the aligned mask image M and the phase image, and inspect the bonding state of the workpiece 90 based on the superimposed image 51. With this configuration, the inspection device 10 can accurately inspect the bonding state of the workpiece 90.

[0088] The processor 11 may determine an effective joining region in the joining region of the phase image in which the phase value is within a predetermined range (S107). In this case, the processor 11 aligns the joining region information with the effective joining region in the process of aligning the joining region information with the phase image. The processor 11 checks the joining state of the workpiece 90 based on the size of the joining region indicated by the joining region information and the size of the effective joining region.

[0089] The processor 11 may cause the notification device 19 to notify information indicating the inspection result of the bonding state. The processor 11 may also display the superimposed image 51 on the display device. This allows the user to know the inspection result of the bonding state.

[0090] In this embodiment, the above-described feature portion may be a recognition mark 93 provided on the outer surface of the workpiece 90. According to the configuration of k, the inspection device 10 can align the bonding region information and the phase image with greater precision.

[0091] [2. Embodiment 2] Embodiment 2 describes a configuration in which visible images obtained by a visible light camera are used for inspection. In the following description of this embodiment, the same configuration and operation as those of the inspection system 1 according to Embodiment 1 will be omitted as appropriate.

[0092] Figure 18 is a block diagram showing an example configuration of inspection system 1a according to Embodiment 2. Compared with inspection system 1 of Embodiment 1, inspection system 1a further includes a visible light camera 20. The visible light camera 20 captures at least a portion of a workpiece 90, which is an example of a subject, and generates visible image data. The visible light camera 20 includes a visible light sensor that detects visible light.

[0093] Figure 19 is a flowchart showing an example of an inspection method according to Embodiment 2. Figure 20 is a schematic diagram illustrating the outline of the inspection method according to Embodiment 2. Compared with the inspection method according to Embodiment 1 shown in Figure 7, the inspection method according to Embodiment 2 shown in Figure 19 further includes a pre-joining visible image acquisition process S201 performed before joining (S102), and a process S202 that aligns and superimposes the pre-joining visible image and the effective joining region image.

[0094] In the pre-joining visible image acquisition process S201, the inspection device 10 acquires a pre-joining visible image IMG5 generated by the visible light camera 20 capturing the second part 92 before joining the workpiece 90.

[0095] In Embodiment 2, the inspection device 10 generates a superimposed image 51 by superimposing the mask image M and the effective bonding area image IMG4 (S108), and also generates a superimposed image 52 by superimposing the pre-bonding visible image IMG5 and the effective bonding area image IMG4 (S202). For example, as shown in Figure 20, the inspection device 10 acquires alignment information to align the pre-bonding visible image IMG5 with one frame of the post-bonding temperature image IMG2. When acquiring the alignment information, the information of the recognition marks 93 that appear in each of the two images is used.

[0096] By using the alignment information obtained in this way, the pre-bonding visible image IMG5 and the effective bonding region image IMG4 derived from the phase image IMG3 can be accurately aligned and superimposed (S202).

[0097] In step S109 of this embodiment, the inspection device 10 determines whether or not there is a bonding defect based on at least one of the superimposed image 51 obtained in step S108 and the superimposed image 52 obtained in step S202.

[0098] As described above, in this embodiment, the processor 11 acquires a pre-bonding visible image IMG5 via the interface 13, which is generated by a visible light camera 20, an example of a visible light imaging device, by capturing images of the workpiece 90 before it is bonded in a predetermined bonding area. The processor 11 may align the pre-bonding visible image IMG5 with the phase image based on the correspondence between the feature portion of the workpiece 90 on the pre-bonding visible image IMG5 and the feature portion on the post-bonding temperature image data shown by the post-bonding temperature image data.

[0099] [3. Embodiment 3] Figure 21 is a block diagram showing an example configuration of inspection system 1b according to Embodiment 3. Compared with inspection system 1 of Embodiment 1, inspection system 1b according to Embodiment 3 shown in Figure 21 includes a laser device 27 equipped with a laser light source and a moving device 31 for moving the workpiece 90. The laser device 27 irradiates laser light for welding or deposition.

[0100] In Embodiment 1, an example was described in which the bonding step S102 in Figure 7 is performed by a laser device different from the inspection device 10. Unlike Embodiment 1, in Embodiment 3, the bonding step S102 is performed by the inspection device 10. For example, the processor 11 of the inspection device 10 performs a pre-bonding temperature image acquisition process S101 to photograph the second part 92 of the workpiece 90, then drives the moving device 31 to place the first part 91 on top of the second part 92 of the workpiece 90, and then causes the laser device 27 to irradiate the laser.

[0101] In bonding step S102, the processor 11 controls the timing of starting and stopping the output of laser light from the laser device 27, as well as the output power, by controlling the laser device 27. The laser device 27 is configured to have a movable laser light source, and the processor 11 may adjust the moving speed of the laser light source by controlling the laser device 27. In order to irradiate the area to be bonded with the laser, the processor 11 may move the workpiece 90 by controlling the moving device 31.

[0102] After executing the bonding step S102 as described above, the processor 11 executes the post-bonding temperature image acquisition process S103.

[0103] As described above, in the inspection system 1b according to this embodiment, the processor 11 of the inspection device 10 is Step S101 involves having the infrared camera 17 capture images of the workpiece 90 in a time series before it is joined in a predetermined joining area, thereby generating multiple pre-joining temperature image data. Step S102 involves joining a workpiece 90 to a laser device 27, which is an example of a joining device. Step S103 involves having the infrared camera 17 capture images of the workpiece 90 in a time series after the workpiece 90 has been joined in the joining region, thereby generating multiple post-joining temperature image data. Step S104 involves applying a Fourier transform or discrete Fourier transform to multiple post-bonding temperature image data to generate a phase image showing the phase characteristics of the workpiece 90, Step S108 involves aligning the bonding region information relating to the bonding region shown by the multiple pre-bonding temperature image data with the phase image, based on the correspondence between the feature portion of the workpiece 90 on the pre-bonding temperature image data shown by at least one of the multiple pre-bonding temperature image data and the feature portion on the post-bonding temperature image data shown by the post-bonding temperature image data. Perform the inspection method which includes the following.

[0104] [4. Other Embodiments] As described above, embodiments have been explained as examples of the technology in this disclosure. However, the technology in this disclosure is not limited to these embodiments and can be applied to embodiments that have been modified, substituted, added, or omitted as appropriate. Furthermore, it is possible to create new embodiments by combining the components described in the above embodiments. Therefore, other embodiments are described below as examples.

[0105] Embodiment 1 describes an example in which a superimposed image 51 is generated by superimposing a mask image M and an effective bonding region image IMG4. Embodiment 2 describes an example in which, in addition to the superimposed image 51, a pre-bonding visible image IMG5 and an effective bonding region image IMG4 are superimposed to generate a superimposed image 52. In addition to these, or instead, the inspection device 10 may generate a superimposed image 53 by superimposing one frame from the post-bonding temperature image IMG2 and the effective bonding region image IMG4.

[0106] Figures 22A, 22B, and 22C show the superimposed images 51, 52, and 53, respectively. The inspection device 10 may determine whether or not there is a bonding defect based on at least one of the superimposed images 51, 52, and 53. In addition to this, or instead, the user may determine whether or not there is a bonding defect based on at least one of the superimposed images 51, 52, and 53.

[0107] In the above embodiment, an inspection method including filtering and binarization was described. However, the processor 11 of the inspection device 10 only needs to be able to inspect the bonding state of the workpiece 90 based on the size of the effective bonding area, and at least one of the filtering and binarization processes may be omitted.

[0108] In the above embodiment, an example was described in which a recognition mark 93 for alignment is provided on the bottom of the second part 92. However, the location where the recognition mark 93 is provided is not limited to the outer surface of the workpiece 90, such as the bottom of the second part 92. For example, the recognition mark 93 may be provided on the outer surface of a support jig, such as a positioning jig or a transport jig, that supports the second part 92. Figure 23 is a perspective view illustrating such a support jig 80. The infrared camera 17 is positioned so that the recognition mark 93 is within its field of view. Therefore, since both the pre-bonding temperature image IMG1 and the post-bonding temperature image IMG2 contain information about the recognition mark 93, the inspection device 10 can accurately align both images. Furthermore, by placing the recognition mark 93 on the support jig 80, the infrared camera 17 can capture the recognition mark 93 even if the first part 91 does not have an opening 91a as shown in Figure 2.

[0109] Furthermore, it is not essential to provide recognition marks 93 on the workpiece 90 or support jig 80 for alignment purposes. For example, the inspection device 10 may align two images by adjusting them so that the positions of common features between the two images being aligned coincide, instead of using recognition marks 93. Examples of such features, other than recognition marks 93, may include markers, edges, contours, centroids, etc., on the workpiece 90 or parts attached to the workpiece 90, or feature quantities indicating at least one of these.

[0110] [5. Examples of embodiments] The following are examples of the aspects of this disclosure.

[0111] <Aspect 1> An input unit for acquiring temperature image data, Equipped with an image processing processor, The aforementioned processor, The infrared imaging device acquires multiple pre-bonding temperature image data, generated by photographing the workpiece in a time series before it is bonded in a predetermined bonding area, via the input unit. The infrared imaging device acquires, via the input unit, a plurality of post-bonding temperature image data generated by photographing the workpiece in a time series after the workpiece has been bonded in the bonding region. A Fourier transform or discrete Fourier transform is applied to the plurality of post-bonding temperature image data to generate a phase image showing the phase characteristics of the workpiece. Based on the correspondence between the feature portion of the workpiece on the pre-bonding temperature image shown by at least one of the plurality of pre-bonding temperature image data and the feature portion on the post-bonding temperature image shown by the post-bonding temperature image data, the bonding region information relating to the bonding region shown by the plurality of pre-bonding temperature image data and the phase image are aligned. Inspection device.

[0112] <Aspect 2> The aforementioned processor, A mask image is generated by applying a binarization process to one of the multiple pre-junction temperature image data to distinguish between the junction region and other regions. The mask image is used as the joining region information and aligned with the phase image. The inspection apparatus described in Embodiment 1.

[0113] <Aspect 3> The aforementioned processor, The aligned mask image and the phase image are superimposed to generate a first superimposed image. The bonding state of the workpiece is inspected based on the first superimposed image. The inspection apparatus described in Embodiment 2.

[0114] <Aspect 4> The aforementioned processor, In the bonding region of the phase image, an effective bonding region is determined in which the phase value is within a predetermined range. In the process of aligning the bonding region information and the phase image, the bonding region information and the effective bonding region are aligned, The joining state of the workpiece is inspected based on the size of the joining region indicated by the joining region information and the size of the effective joining region. An inspection apparatus according to any one of embodiments 1 to 3.

[0115] <Aspect 5> The inspection apparatus according to embodiment 3 or 4, wherein the processor causes a notification device to notify it of information indicating the inspection result of the junction state.

[0116] <Aspect 6> The inspection apparatus according to embodiment 3 or 5, wherein the processor causes the first superimposed image to be displayed on a display device.

[0117] <Aspect 7> The aforementioned processor, The visible light imaging device acquires a visible image generated by photographing the workpiece before it is joined in a predetermined joining area, via the input unit. Based on the correspondence between the characteristic portion of the workpiece on the visible image and the characteristic portion of the post-bonding temperature image shown in the post-bonding temperature image data, the visible image and the phase image are aligned. An inspection apparatus according to any one of embodiments 1 to 6.

[0118] <Aspect 8> The aforementioned processor, A second superimposed image is generated by superimposing the aligned visible image and the phase image. The second superimposed image is displayed on the display device. The inspection apparatus described in aspect 7.

[0119] <Pattern 9> The inspection device according to any one of embodiments 1 to 8, wherein the characteristic portion is a recognition mark provided on the outer surface of the workpiece or on the outer surface of a support jig that supports the workpiece.

[0120] <Aspect 10> The steps include: acquiring multiple pre-bonding temperature image data generated by an infrared imaging device capturing images of the workpiece in a time series before the workpiece is bonded in a predetermined bonding area; The steps include: acquiring a plurality of post-bonding temperature image data generated by the infrared imaging device capturing images of the workpiece in a time series after the workpiece has been bonded in the bonding region; The steps include: applying a Fourier transform or discrete Fourier transform to the plurality of post-bonding temperature image data to generate a phase image showing the phase characteristics of the workpiece; A step of aligning the bonding region information relating to the bonding region shown in the plurality of pre-bonding temperature image data with the phase image, based on the correspondence between the characteristic portion of the workpiece shown in the pre-bonding temperature image data shown in at least one of the plurality of pre-bonding temperature image data and the characteristic portion of the workpiece shown in the post-bonding temperature image data shown in the post-bonding temperature image data. Testing methods, including those mentioned above.

[0121] <Aspect 11> The processor provides a step of causing an infrared imaging device to capture images of the workpiece in a time series before the workpiece is bonded in a predetermined bonding area to generate multiple pre-bonding temperature image data, The processor performs the steps of having the bonding device bond the workpiece, The processor, after the workpiece has been joined in the joining region, causes the infrared imaging device to photograph the workpiece in a time series to generate a plurality of post-joining temperature image data, The processor performs a Fourier transform or discrete Fourier transform on the plurality of post-bonding temperature image data to generate a phase image showing the phase characteristics of the workpiece. The processor performs the step of aligning the bonding region information relating to the bonding region shown in the plurality of pre-bonding temperature image data with the phase image, based on the correspondence between the characteristic portion of the workpiece shown in the pre-bonding temperature image data shown in at least one of the plurality of pre-bonding temperature image data and the characteristic portion of the workpiece shown in the post-bonding temperature image data shown in the post-bonding temperature image data. Testing methods, including those mentioned above. [Industrial applicability]

[0122] This disclosure is applicable to joining systems and joining methods. [Explanation of symbols]

[0123] 1. Inspection System 1. Method Claim 10 Inspection equipment 11 processors 12 Storage device 13 Interfaces 15 Control Box 16 Power supply 17 Infrared Camera 18 Excitation source 19. Notification device 20 Visible light camera 27 Laser devices 31 Mobile device 90 Work 91 First part 91a opening 92 Second part 92a Rib 92b Top surface 93 Recognition Mark 95 Joint area

Claims

1. An input unit for acquiring temperature image data, Equipped with an image processing processor, The aforementioned processor, The infrared imaging device acquires multiple pre-bonding temperature image data, generated by photographing the workpiece in a time series before it is bonded in a predetermined bonding area, via the input unit. The infrared imaging device acquires, via the input unit, a plurality of post-bonding temperature image data generated by photographing the workpiece in a time series after the workpiece has been bonded in the bonding region. A Fourier transform or discrete Fourier transform is applied to the plurality of post-bonding temperature image data to generate a phase image showing the phase characteristics of the workpiece. Based on the correspondence between the characteristic portion of the workpiece on the pre-bonding temperature image shown by at least one of the plurality of pre-bonding temperature image data and the characteristic portion on the post-bonding temperature image shown by the post-bonding temperature image data, the bonding region information relating to the bonding region shown by the plurality of pre-bonding temperature image data and the phase image are aligned. Inspection device.

2. The aforementioned processor, A mask image is generated by applying a binarization process to one of the multiple pre-bonding temperature image data to distinguish between the bonding region and other regions. The mask image is used as the joining region information and aligned with the phase image. The inspection apparatus according to claim 1.

3. The aforementioned processor, The aligned mask image and the phase image are superimposed to generate a first superimposed image. The bonding state of the workpiece is inspected based on the first superimposed image. The inspection apparatus according to claim 2.

4. The aforementioned processor, In the bonding region of the phase image, an effective bonding region is determined in which the phase value is within a predetermined range. In the process of aligning the bonding region information and the phase image, the bonding region information and the effective bonding region are aligned, The joining state of the workpiece is inspected based on the size of the joining region indicated by the joining region information and the size of the effective joining region. The inspection apparatus according to claim 1.

5. The inspection apparatus according to claim 3 or 4, wherein the processor causes a notification device to notify it of information indicating the inspection result of the bonding state.

6. The inspection apparatus according to claim 3, wherein the processor causes the first superimposed image to be displayed on a display device.

7. The aforementioned processor, The visible light imaging device acquires a visible image generated by photographing the workpiece before it is joined in a predetermined joining area, via the input unit. Based on the correspondence between the characteristic portion of the workpiece on the visible image and the characteristic portion of the post-bonding temperature image shown in the post-bonding temperature image data, the visible image and the phase image are aligned. The inspection apparatus according to claim 1.

8. The aforementioned processor, A second superimposed image is generated by superimposing the aligned visible image and the phase image. The second superimposed image is displayed on the display device. The inspection apparatus according to claim 7.

9. The inspection apparatus according to claim 1, wherein the aforementioned characteristic portion is a recognition mark provided on the outer surface of the workpiece or on the outer surface of a support jig that supports the workpiece.

10. The steps include: acquiring multiple pre-bonding temperature image data generated by an infrared imaging device capturing images of the workpiece in a time series before the workpiece is bonded in a predetermined bonding area; The steps include: acquiring a plurality of post-bonding temperature image data generated by the infrared imaging device capturing images of the workpiece in a time series after the workpiece has been bonded in the bonding region; The steps include: applying a Fourier transform or discrete Fourier transform to the plurality of post-bonding temperature image data to generate a phase image showing the phase characteristics of the workpiece; A step of aligning the bonding region information relating to the bonding region shown in the plurality of pre-bonding temperature image data with the phase image, based on the correspondence between the characteristic portion of the workpiece on the pre-bonding temperature image shown in at least one of the plurality of pre-bonding temperature image data and the characteristic portion on the post-bonding temperature image shown in the post-bonding temperature image data. Testing methods, including those mentioned above.

11. The processor provides a step of causing an infrared imaging device to capture images of the workpiece in a time series before the workpiece is bonded in a predetermined bonding area to generate multiple pre-bonding temperature image data, The processor performs the steps of having the bonding device bond the workpiece, The processor, after the workpiece has been joined in the joining region, causes the infrared imaging device to photograph the workpiece in a time series to generate a plurality of post-joining temperature image data, The processor performs a Fourier transform or discrete Fourier transform on the plurality of post-bonding temperature image data to generate a phase image showing the phase characteristics of the workpiece. The processor performs the step of aligning the bonding region information relating to the bonding region shown by the plurality of pre-bonding temperature image data with the phase image, based on the correspondence between the characteristic portion of the workpiece shown by at least one of the plurality of pre-bonding temperature image data and the characteristic portion of the post-bonding temperature image shown by the post-bonding temperature image data. Testing methods, including those mentioned above.

Images