Bonding state inspection device and bonding state inspection method

Abstract

A bonding state inspection device (1) continuously detects, in the overlap direction of two substrates (W1, W2) which are at least partially bonded, a temporally-changing boundary portion between a portion where the two substrates (W1, W2) are bonded to each other and a portion where the two substrates (W1, W2) are not bonded. The bonding state inspection device (1) comprises: an imaging unit (21) that captures an image of a region including the tip end of a blade (121); a boundary portion identification unit (919) that, in a state in which the blade (121) has been inserted between the substrates (W1, W2), analyzes the captured image captured by the imaging unit (21) so as to identify the boundary portion between the bonded portion and the unbonded portion of the substrates (W1, W2); and a bonding strength calculation unit (913) that calculates the length of the unbonded portion between the blade (121) and the boundary portion in the substrates (W1, W2), and calculates the bonding strength of the substrates (W1, W2) on the basis of the calculated unbonded portion length.

Description

Bonding condition inspection device and bonding condition inspection method

[0001] The present invention relates to a bonding state inspection device and a bonding state inspection method.

[0002] As a method for evaluating the bonding strength of two bonded substrates, the so-called crack and opening method has been proposed, in which the bonding strength is evaluated based on the length from the periphery of the substrates to the boundary between the peeled portion and the bonded portion when a blade is inserted between the two bonded substrates with a predetermined pressing force (see, for example, Patent Document 1).

[0003] International Publication No. 2018 / 084285

[0004] Incidentally, when carrying out the crack and opening method described in Patent Document 1, there is a need to analyze the bonding state of the two substrates in more detail by observing the changes over time in the boundary between the peeled portion and the bonded portion immediately after inserting the blade between the two substrates.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a bonding state inspection device and a bonding state inspection method that can analyze the bonding state of two substrates in detail.

[0006] In order to achieve the above object, the bonding state inspection device according to the present invention continuously detects, from the overlapping direction of two substrates that are at least partially bonded, a boundary portion between a bonded portion and an unbonded portion of the two substrates, which changes over time.

[0007] From another perspective, the bonding condition inspection method of the present invention continuously detects, from the overlapping direction of two substrates that are at least partially bonded, a boundary portion between a bonded portion and an unbonded portion of the two substrates, which changes over time.

[0008] According to the present invention, the boundary portion between the bonded portion and the non-bonded portion of the two substrates, which changes over time, is continuously detected based on the overlapping direction of the at least partially bonded two substrates, thereby making it possible to grasp the influence of the bonding state of the two substrates on the change over time of the boundary portion, and therefore to analyze the bonding state of the two substrates in detail.

[0009] 1 is a schematic configuration diagram of a bonding state inspection device according to a first embodiment of the present invention. FIG. 2 is a schematic side view showing a part of the bonding state inspection device according to the first embodiment. FIG. 3 is a schematic plan view showing a part of the bonding state inspection device according to the first embodiment. FIG. 4 is a schematic cross-sectional view showing a part of the bonding state inspection device according to the first embodiment. FIG. 5 is a block diagram showing the functional configuration of a control unit according to the first embodiment. FIG. 6 is an explanatory diagram of the operation of the bonding state inspection device according to the first embodiment. FIG. 7 is a flowchart showing a bonding state inspection method executed by the bonding state inspection device according to the first embodiment. FIG. 8 is a diagram showing a correspondence relationship between the bonding strength of two substrates and the insertion amount of a blade, among the inspection results obtained by the bonding state inspection device according to the first embodiment. FIG. 9 is a diagram showing a correspondence relationship between the bonding strength of two substrates and the pressing force applied when inserting the blade, among the inspection results obtained by the bonding state inspection device according to the first embodiment. FIG. 10 is a schematic configuration diagram of a bonding state inspection device according to a second embodiment of the present invention. FIG. 11 is a schematic cross-sectional view showing a part of the bonding state inspection device according to the second embodiment. FIG. 12 is a schematic plan view showing a part of the bonding state inspection device according to the second embodiment. FIG. 13 is a block diagram showing the functional configuration of a control unit according to the second embodiment. FIG. 14 is an explanatory diagram of the operation of the bonding state inspection device according to the second embodiment. FIG. 1 is a flowchart showing a bonding state inspection method executed by a bonding state inspection device according to embodiment 2. FIG. 2 is a diagram showing a state in which a pressing portion is brought into contact with one of two substrates of a bonding state inspection device according to embodiment 2. FIG. 3 is a diagram showing a state in which one of two substrates of a bonding state inspection device according to embodiment 2 is pressed into contact with the other. FIG. 4 is a diagram showing a state immediately after holding of one of two substrates of a bonding state inspection device according to embodiment 2 is released. FIG. 5 is a schematic configuration diagram of a bonding state inspection device according to a modified example. FIG. 6 is a schematic plan view showing a part of a bonding state inspection device according to a modified example. FIG. 7 is a schematic cross-sectional view showing a part of a bonding state inspection device according to a modified example.

[0010] (Embodiment 1) A bonded state inspection device according to an embodiment of the present invention will be described below with reference to the drawings. The bonded state inspection device according to this embodiment continuously detects a boundary portion between a bonded portion and an unbonded portion of two substrates that changes over time from the overlapping direction of the two substrates that are at least partially bonded. Here, "continuously detecting" means detecting continuously on a time axis, for example.

[0011] As shown in FIG. 1 , the bonding state inspection device 1 according to this embodiment includes a stage 11 supporting the substrates W1 and W2, a substantially rectangular blade 121, a blade holder 122 that clamps the blade 121 in the thickness direction, a blade driver 13 that drives the blade 121 in a direction substantially parallel to the mounting surface 11a of the stage 11 for the substrates W1 and W2, as indicated by arrow AR1, a blade elevation driver 17, imaging units 21 and 24, and a light source 23. Here, the substrates W1 and W2 are, for example, disk-shaped wafers. The bonding state inspection device 1 according to this embodiment evaluates the bonding strength of the substrates W1 and W2, whose bonding surfaces have been activated, when they are bonded together. The bonding state inspection device 1 also includes an operation unit 95 that allows a user to start an inspection or to elevate and lower the blade 121 when preparing for the inspection. The stage 11 is formed of a translucent material that transmits at least infrared light, such as transparent glass. The stage 11 is a substrate holder that has an electrostatic chuck, a vacuum chuck, etc., and attracts and holds the substrates W1 and W2. The rotation driver 14 rotates the stage 11 around a rotation axis J1 that extends along the overlapping direction of the substrates W1 and W2 held on the stage 11.

[0012] The blade 121 has a thickness of approximately 0.1 mm and is, for example, an FH-10 blade manufactured by Feather Corporation. The blade driver 13 includes a slider 132 that supports the blade holder 122 via an arm 123, and a slider driver 131 that drives the slider 132 in the direction indicated by arrow AR1. A pressure sensor 14 that detects the pressure applied to the blade 121 is interposed between the slider 132 and the arm 123. The slider driver 131 has an encoder that outputs measurement value information that indicates a measurement value reflecting the amount of movement of the slider 132 to the control unit 90. The blade elevation driver 17 is a blade overlapping direction driver that drives the blade holder 122 in the overlapping direction of the substrates W1 and W2, i.e., in the Z-axis direction, as indicated by arrow AR2, thereby changing the position of the edge of the blade 121 in the overlapping direction of the substrates W1 and W2. The blade lifting / lowering drive unit 17 lifts and lowers the blade 121 in response to an operation by the user to lift and lower the blade 121 on the operating unit.

[0013] The imaging unit 21 is, for example, an IR camera and is positioned so as to be able to image the portion of the substrates W1 and W2 held on the stage 11, including the periphery where the blade 121 is inserted, from one side in the overlapping direction of the substrates W1 and W2, i.e., from vertically above. The imaging unit 24 is, for example, a visible light camera and images the edge of the blade 121 on the -Y direction side from a direction perpendicular to the overlapping direction of the substrates W1 and W2, i.e., from the +X direction, as shown in FIG. 2 . While viewing the image captured by the imaging unit 24, a user can adjust the position of the blade 121 by operating the operation unit 95 to raise and lower the blade 121. The light source 23 is, for example, a light source that emits infrared light or visible light and emits light toward the stage 11 via a reflector 241 disposed vertically below the stage 11. A light diffuser 242 is disposed vertically below the stage 11 to diffuse the light emitted from the reflector 241 toward the entire stage 11. Here, if the light source 23 is disposed, for example, vertically below the light diffusion plate 242 and facing the center of the light diffusion plate 242, so that light emitted from the light source 23 is directly incident on the light diffusion plate 242, the central portion of the light diffusion plate 242 facing the light source 23 in the vertical direction will be relatively bright and the peripheral portion will be relatively dark, resulting in a difference in luminous intensity within the light diffusion plate 242. In contrast, in this embodiment, the light emitted from the light source 23 is reflected once by the reflector 241 and then incident on the light diffusion plate 242, thereby making it possible to achieve a uniform luminous intensity throughout the light diffusion plate 242.

[0014] As shown in FIG. 3A , the blade holder 122 is provided with a flat, box-shaped chamber 161 that is open on the side opposite to the side fixed to the blade holder 122. The chamber 161 is made of a light-transmitting material such as transparent glass and is arranged to cover at least an area including the edge of the blade 121 and portions of the two substrates W1 and W2 when the blade 121 is inserted between the substrates W1 and W2. More specifically, the chamber 161 is arranged to cover the entire blade 121 and the peeled portions Po1 of the substrates W1 and W2 when the blade 121 is inserted between the substrates W1 and W2. The chamber 161 also includes a gas supply unit 162 that generates an airflow within the chamber 161 and a humidity sensor 163 that detects humidity within the chamber 161. The gas supply unit 162 is, for example, a blower. 3B, the gas discharged from gas supply unit 162 into chamber 161 is supplied throughout chamber 161. This allows the humidity within chamber 161 to be maintained at a preset target humidity and target temperature.

[0015] 1 , the control unit 90 includes a programmable logic controller and a personal computer, and has a processor and a memory for storing programs. As the processor executes the programs stored in the memory, the control unit 90 functions as a blade control unit 911, a blade elevation control unit 920, an image acquisition unit 912, a boundary portion identification unit 919, a bonding strength calculation unit 913, an insertion amount measurement unit 914, a pressing force measurement unit 915, an elapsed time measurement unit 916, a correspondence information generation unit 917, and a gas supply control unit 918, as shown in FIG. 4 . The memory also includes an image storage unit 931 for storing, in chronological order, image information representing images captured by the imaging unit 21, a bonding strength storage unit 932, an insertion amount storage unit 933, a pressing force storage unit 934, an elapsed time storage unit 935, and a correspondence information storage unit 936. The image memory unit 931 stores image information indicating the captured image captured by the imaging unit 21 in a state in which the stage 11 holding the substrates W1 and W2 is rotated by a specified rotation angle from a preset reference posture and the blade 121 is inserted between the substrates W1 and W2, in association with rotation angle information indicating the rotation angle.

[0016] The bond strength storage unit 932 stores bond strength information indicating the calculated bond strength between the bonded substrates W1 and W2 in chronological order from the time when the blade 121 starts to be inserted.

[0017] The insertion amount memory unit 933 stores insertion amount information indicating the insertion amount of the blade 121 into the bonded substrates W1 and W2 in chronological order from the start of insertion of the blade 121 into the substrates W1 and W2. The pressing force memory unit 934 stores pressing force information indicating the pressing force applied when the blade 121 is inserted between the bonded substrates W1 and W2 in chronological order from the start of insertion of the blade 121. The elapsed time memory unit 935 stores elapsed time information indicating the elapsed time from the start of insertion of the blade 121 into the substrates W1 and W2 in chronological order. The correspondence information memory unit 936 stores correspondence information indicating at least two correspondences selected from the bonding strength of the two substrates W1 and W2, the insertion amount of the blade 121, the pressing force applied when the blade 121 is inserted between the substrates W1 and W2, and the elapsed time from the start of insertion of the blade 121 between the substrates W1 and W2.

[0018] The blade control unit 911 controls the operation of the blade driving unit 13 by generating a control signal and outputting it to the blade driving unit 13. When a user operates the operation unit 95 to start inspection, the blade control unit 911 generates a control signal for driving the blade 121 so as to insert the edge of the blade 121 between the two substrates W1, W2, and outputs the control signal to the blade driving unit 13. The blade lift control unit 920 controls the operation of the blade lift driving unit 17 by generating a control signal and outputting it to the blade lift driving unit 17. When a user operates the operation unit 95 to lift or lower the blade 121, the blade lift control unit 920 generates a control signal for lifting or lowering the blade 121, blade holding unit 122, and blade driving unit 13 together, and outputs the control signal to the blade lift driving unit 17.

[0019] The gas supply control unit 918 controls the flow rate of gas discharged from the gas supply unit 162 so that the humidity inside the chamber 161 detected by the humidity sensor 163 becomes a preset target humidity. As a result, at least the region where the boundary portion described above is located in the location where the two substrates W1, W2 are located is maintained at the preset target humidity.

[0020] The image acquisition unit 912 acquires image information captured by the imaging unit 21 and transferred from the imaging unit 21, and stores the acquired image information in the image storage unit 931 in chronological order.

[0021] The boundary portion identifying unit 919 identifies the boundary portion between the bonded and non-bonded portions of the two substrates W1, W2 by analyzing the captured image captured by the imaging unit 21 with the blade 121 inserted between the two substrates W1, W2. Here, the boundary portion identifying unit 919 detects the position of the boundary portion using a well-known edge detection technique. As the well-known edge detection technique, an edge detection technique using a Sobel filter, a Laplacian filter, a Canny filter, or the like can be adopted. The boundary portion identifying unit 919 notifies the bonding strength calculation unit 913 of information indicating the identified boundary portion.

[0022] The bonding strength calculation unit 913 calculates a non-bonding portion distance from the portion of the two substrates W1, W2 that abuts against the blade 121 to the boundary portion of the two substrates W1, W2 indicated by the information notified from the boundary portion identification unit 919, using the captured image captured by the imaging unit 21, and calculates the bonding strength of the two substrates W1, W2 based on the calculated non-bonding portion distance. Here, the bonding strength calculation unit 913 calculates the non-bonding portion distance from the tip of the blade 121 to the boundary portion in the image indicated by the image information. However, as shown in FIG. 5 , the tip of the blade 121 is not aligned with the portion where the blade 121 abuts against the substrates W1, W2. Therefore, the bonding strength calculation unit 913 uses a distance L that corresponds to the sum of the distance L11 from the tip of the blade 121 to the boundary portion and a preset distance L11 from the tip of the blade 121 to the abutting portion. 5, the bonding strength calculation unit 913 calculates the bonding strength based on the thicknesses t1 and t2 of the substrates W1 and W2, the thickness 2y of the blade 121, and the non-bonding portion distance L from the tip of the blade 121 to the boundary portion. Here, the bonding strength calculation unit 913 calculates the bonding strength using the relational expression (1) below.

[0023]

[0024] Here, t1 and t2 are the thicknesses of the substrates W1 and W2, E1 and E2 are the Young's moduli of the substrates W1 and W2, L is the non-bonding portion distance from the tip of the blade 121 to the boundary between the two substrates W1 and W2, and y is the thickness equivalent to half the thickness of the blade 121. The bonding strength calculation unit 913 stores bonding strength information indicating the calculated bonding strength in chronological order in the bonding strength storage unit 932. Furthermore, the bonding strength calculation unit 913 calculates the non-bonding portion distance corresponding to each rotation angle of the stage 11 using each captured image indicated by the image information stored in the image storage unit 931, and calculates the bonding strength of the two substrates W1 and W2 based on the calculated non-bonding portion distance.

[0025] 4 , the insertion amount measuring unit 914 detects that the blade 121 has come into contact with the substrates W1 and W2 based on the pressure detected by the pressure sensor 14. After detecting that the blade 121 has come into contact with the substrates W1 and W2, the insertion amount measuring unit 914 measures the insertion amount of the blade 121 between the substrates W1 and W2 based on the measurement value information output from the encoder of the blade driver 13, and stores the insertion amount information indicating the measured insertion amount in chronological order in the insertion amount storage unit 933. Here, the insertion amount corresponds to the amount of movement of the blade holder 122 when moved by the blade driver 13 in a direction approaching the substrates W1 and W2.

[0026] The lateral pressure measurement unit 915 detects that the blade 121 has come into contact with the substrates W1, W2, based on the pressure detected by the pressure sensor 14. After detecting that the blade 121 has come into contact with the substrates W1, W2, the pressing force measurement unit 915 measures the pressing force of the blade 121 when the blade 121 is inserted between the substrates W1, W2, based on the measurement value information output from the pressure sensor 14, and stores pressing force information indicating the measured pressing force in chronological order in the pressing force memory unit 934. The elapsed time measurement unit 916 detects that the blade 121 has come into contact with the substrates W1, W2, based on the pressure detected by the pressure sensor 14. The elapsed time measurement unit 916 measures the elapsed time from the time when it detected that the blade 121 has come into contact with the substrates W1, W2, and stores elapsed time information indicating the measured elapsed time in the elapsed time memory unit 935, based on the pressure detected by the pressure sensor 14.

[0027] The correspondence information generator 917 generates correspondence information indicating at least two correspondences selected from the bonding strength of the two substrates W1 and W2, the insertion amount of the blade 121, the pressing force applied when inserting the blade 121 between the substrates W1 and W2, and the elapsed time from the start of insertion of the blade 121 between the substrates W1 and W2. Specifically, the correspondence information generator 917 generates the correspondence information using the bonding strength information stored in the bonding strength memory unit 932 and any of the insertion amount information stored in the insertion amount memory unit 933, the pressing force information stored in the pressing force memory unit 934, and the elapsed time information stored in the elapsed time memory unit 935. The correspondence information generator 917 then stores the generated correspondence information in the correspondence information memory unit 936.

[0028] Next, a bonding state inspection method using the bonding state inspection device 1 according to this embodiment will be described with reference to FIG. 6 . Assume that the substrates W1 and W2 are already supported on the stage 11. First, the blade driver 13 starts moving the blade 121 in the direction of insertion between the substrates W1 and W2 (step S101). Next, the insertion amount measurement unit 914 measures the insertion amount of the blade 121 between the substrates W1 and W2 based on the measurement value information output from the encoder of the blade driver 13, and stores the insertion amount information indicating the measured insertion amount in the insertion amount memory unit 933 in chronological order (step S102). Next, the pressing force measurement unit 915 measures the pressing force of the blade 121 when inserting the blade 121 between the substrates W1 and W2 based on the measurement value information output from the pressure sensor 14, and stores the pressing force information indicating the measured pressing force in the pressing force memory unit 934 in chronological order (step S103). Thereafter, the elapsed time measurement unit 916 measures the elapsed time from the start of insertion of the blade 121 between the substrates W1 and W2, and stores the elapsed time information indicating the measured elapsed time in the elapsed time memory unit 935 in chronological order (step S104).

[0029] Next, the bonding strength calculation unit 913 calculates the distance from the contact point of the blade 121 on the two substrates W1 and W2 to the boundary between the two substrates W1 and W2 using the captured images captured by the imaging unit 21, and calculates the bonding strength of the two substrates W1 and W2 based on the calculated distance. The bonding strength calculation unit 913 then chronologically stores bonding strength information indicating the calculated bonding strength in the bonding strength storage unit 932 (step S105). The blade control unit 911 then determines whether a preset inspection termination condition has been met (step S106). This inspection termination condition may be set, for example, to the insertion distance of the blade 121 between the substrates W1 and W2 reaching a preset target insertion distance. If the blade control unit 911 determines that the inspection termination condition has not yet been met (step S106: No), it continues inserting the blade 121 between the substrates W1 and W2, and the process of step S102 is executed again.

[0030] On the other hand, if the blade control unit 911 determines that the inspection end condition has not yet been satisfied (step S106: No), it stops the insertion of the blade 121 (step S107). Thereafter, the correspondence information generation unit 917 generates correspondence information using the bonding strength information stored in the bonding strength memory unit 932 and any one of the insertion amount information stored in the insertion amount memory unit 933, the pressing force information stored in the pressing force memory unit 934, and the elapsed time information stored in the elapsed time memory unit 935. Then, the correspondence information generation unit 917 stores the generated correspondence information in the correspondence information memory unit 936 (step S108).

[0031] The correspondence information is, for example, information indicating the correspondence relationship between the bonding strength and the insertion amount as shown in FIG. 7A, information indicating the correspondence relationship between the bonding strength and the pressing force as shown in FIG. 7B, or information indicating the correspondence relationship between the bonding strength and the elapsed time from the start of insertion of the blade 121 as shown in FIG. 7C.

[0032] In the bonding condition inspection method according to this embodiment, the bonding surfaces of the wafer substrates W1 and W2 are activated by plasma treatment or particle beam irradiation, then the bonding surfaces are made hydrophilic by water washing, and the centers of the bonding surfaces of the substrates W1 and W2 are brought into contact with each other and bonded together. Then, heat treatment is performed to firmly bond the substrates W1 and W2, and the bonding strength between the substrates W1 and W2 is measured by inserting a blade 121 into the periphery of the substrates W1 and W2. The bonding condition can be evaluated in more detail by evaluating the correspondence between the insertion depth and pressing force of the blade 122, the elapsed time since the blade 121 was inserted, and the humidity or temperature.

[0033] As described above, the bonding state inspection device 1 according to the present embodiment continuously detects the boundary between the bonded and unbonded portions of the two substrates W1, W2, which changes over time, from the overlapping direction of the two substrates W1, W2 that are at least partially bonded. This makes it possible to grasp the influence of the change over time of the boundary on the bonding state of the two substrates W1, W2, and therefore to analyze the bonding state of the two substrates W1, W2 in detail.

[0034] If moisture penetrates the bonded interface between the bonded substrates W1 and W2, the moisture can cause molecular bonds at the bonded portion to separate, resulting in a decrease in the strength of the bonded portion. Therefore, variations in the humidity around the substrates W1 and W2 can lead to variations in the measured bond strength of the bonded portion and a decrease in the bond strength. In response to this, the bond condition inspection device 1 according to this embodiment includes a chamber 161 arranged to cover at least the blade insertion portions of the two substrates W1 and W2 into which the blades 121 are inserted, and a gas supply unit 162 that supplies humidity-adjusted gas into the chamber 161 to maintain a positive pressure inside the chamber 161 relative to the outside of the chamber 161 and maintain the humidity inside the chamber 161 at a predetermined humidity. This maintains a constant humidity around the substrates W1 and W2 in the chamber 161, thereby suppressing variations in the measured bond strength of the bonded portion.

[0035] Furthermore, if moisture is present around the substrates W1 and W2, the moisture will penetrate into the bonded interface between the substrates W1 and W2, causing the bond strength to change over time. Therefore, the bonded state inspection device 1 according to this embodiment measures the change over time in the bond strength of the bonded portion of the substrates W1 and W2.

[0036] (Embodiment 2) A bonding state inspection device according to this embodiment differs from embodiment 1 in that it includes a substrate holding unit that holds two substrates spaced apart from each other, a pressing mechanism that presses the central portion of one of the two substrates toward the other, thereby bringing the central portion of one into contact with the other, and a boundary position detection unit that detects the position of the boundary portion of the two substrates on at least one imaginary straight line that extends radially from the central portions of the two substrates.

[0037] As shown in FIG. 8 , a bonding state inspection device 2001 according to this embodiment includes a stage 2011 supporting a substrate W1, multiple substrate holders 171 that respectively hold multiple locations on the periphery of a substrate W2, a holder driver 172 that raises and lowers the substrate holders 171 and moves them horizontally, a pressing mechanism 15, an imaging unit 22, and a light source 23. Note that in FIG. 8 , components similar to those in the first embodiment are denoted by the same reference numerals as in FIG. 1 . Here, the substrates W1 and W2 are, for example, disk-shaped wafers. The bonding state inspection device 2001 according to this embodiment evaluates the activation states of the substrates W1 and W2, whose bonding surfaces have been activated, based on the wetting and spreading speed as bonding progresses after the central portions of the substrates W1 and W2 are brought into contact with each other. The bonding state inspection device 2001 also includes an operation unit 95 that allows a user to perform an operation to start the inspection. Like the stage 11 described in the first embodiment, the stage 2011 is formed of a translucent material that transmits at least infrared light, such as transparent glass. The stage 2011 has an electrostatic chuck, a vacuum chuck, or the like, and adsorbs and holds the substrate W1. The substrate holder 171 has an inclined surface 1711a that abuts the vertically lower side of the periphery of one of the two substrates W1, W2 that is positioned vertically upper of the two substrates W1, W2 that are arranged apart from each other, and includes a substrate holder 1711 that supports the periphery of one of the substrates W2, and an arm 1712 to the tip of which the substrate holder 1711 is fixed. The holder driver 172 supports the end of the arm 1712 of the substrate holder 171 on the side opposite to the substrate holder 1711 side, and raises and lowers the arm 1712.

[0038] 9A , the pressing mechanism 15 includes a pressing unit 151 that contacts the substrate W2, an overlapping direction driving unit 152 that moves the pressing unit 151 in the overlapping direction of the substrates W1 and W2, and a horizontal driving unit 153 that moves the pressing unit 151 and the overlapping direction driving unit 152 together as indicated by arrow AR2 in a direction perpendicular to the overlapping direction of the substrates W1 and W2, i.e., in a direction approximately parallel to the support surface 2011 a of the stage 2011 for the substrate W1. As shown in FIG. 9B , the holder driving units 172 are installed at three locations on the outer periphery of the stage 2011. The substrate holders 171 extend from each of the three holder driving units 172 toward the center of the stage 2011, and support the periphery of the substrate W2 at their tips. Here, the holder drive unit 172 presses the center of the substrate W2 toward the substrate W1 using the pressing mechanism 171, thereby bringing the center of the substrate W2 into contact with the substrate W1, and then detaches the substrate holder 171 from the substrate W2 as the boundary between the joined and peeled portions of the two substrates W1 and W2 moves toward the periphery of the substrates W1 and W2.

[0039] Returning to Figure 8, the imaging unit 22 is, for example, an IR camera, similar to the imaging unit 21 described in embodiment 1, and is positioned at a position where it can image the entire substrate W1 held on the stage 11 and the entire substrate W2 supported by multiple substrate holding units 171 from one side in the overlapping direction of the substrates W1 and W2, i.e., from vertically above.

[0040] The control unit 2090 has the same hardware configuration as the control unit 90 described in embodiment 1, and by the processor executing a program stored in the memory, it functions as a pressure control unit 2919, an image acquisition unit 2912, a boundary position detection unit 2920, a movement speed measurement unit 2921, a stop position detection unit 2922, an elapsed time measurement unit 916, and a correspondence information generation unit 2923, as shown in Fig. 10. Note that in Fig. 10, the same components as those in embodiment 1 are denoted by the same reference numerals as in Fig. 4. The memory also includes an image storage unit 2931 that stores image information indicating images captured by the imaging unit 22 in chronological order, a boundary position storage unit 2937, a movement speed storage unit 2938, a stop position storage unit 2939, an elapsed time storage unit 935, and a correspondence information storage unit 2936. 11, the boundary position storage unit 2937 stores position information indicating positions PBL1_11, PBL1_12, PBL1_21, and PBL1_22 on two virtual straight lines VL1 and VL2 extending radially from the centers of the two substrates W1 and W2 at the boundary between the bonded portions and the peeled portions of the two substrates W1 and W2. Note that in this embodiment, an example will be described in which there are two virtual straight lines VL1 and VL2, but the number of virtual straight lines is not particularly limited, and the boundary position storage unit 2937 may store position information indicating positions on, for example, three or more virtual straight lines that intersect with each other at the same intersection.

[0041] 10 , the movement speed memory unit 2938 stores, in chronological order, movement speed information indicating the movement speed of the boundary portion between the bonded portion and the peeled portion of the two substrates W1, W2 as it moves toward the periphery of the substrates W1, W2. The stop position memory unit 2939 stores stop position information indicating the stop position when the movement of the boundary portion of the two substrates W1, W2 stops. The correspondence information memory unit 2936 stores correspondence information indicating at least two correspondences selected from the elapsed time from the point in time when the support of the periphery of the substrate W2 by the substrate holder 171 was released after the centers of the substrates W1, W2 came into contact with each other, the movement speed of the boundary portion of the substrates W1, W2, the stop position of the boundary portion, and virtual line identification information that identifies the virtual line.

[0042] The pressing control unit 2919 generates a control signal and outputs it to the pressing mechanism 15 to control the operation of the overlapping direction driving unit 152 and the horizontal driving unit 153 of the pressing mechanism 15. Furthermore, the pressing control unit 2919 controls the overlapping direction driving unit 152 and the horizontal driving unit 153 so that after bringing the central portion of the substrate W2 into contact with the substrate W1, the pressing control unit 2919 separates the pressing unit 151 from the substrate W2 and then moves it in a direction perpendicular to the overlapping direction of the substrates W1 and W2 to retract it to the outside of the projection area in the overlapping direction of the substrates W1 and W2. When the user operates the operation unit 95 to start inspection, the pressing control unit 2919 in response to this first generates a control signal for pressing the central portion of the substrate W2 with the pressing unit 151 to bring the central portion of the substrate W2 into contact with the substrate W1, and outputs the control signal to the pressing mechanism 15. Next, the pressing control unit 2919 generates a control signal to move the pressing unit 151 away from the substrate W2 and then in a direction perpendicular to the overlapping direction of the substrates W1 and W2, thereby retracting it outside the projection area in the overlapping direction of the substrates W1 and W2, and outputs the control signal to the pressing mechanism 15.

[0043] The image acquisition unit 2912 acquires image information captured by the imaging unit 22 and transferred from the imaging unit 22, and stores the acquired image information in chronological order in the image storage unit 2931. Here, the image acquisition unit 2912 stores, in the image storage unit 2931, image information indicating each of the captured images captured by the imaging unit 22 at a preset imaging period after the central portion of the substrate W2 comes into contact with the substrate W1.

[0044] The boundary position detection unit 2920 detects the boundary between the bonded and separated portions of the two substrates W1 and W2 using the captured images captured by the imaging unit 22. Here, the boundary position detection unit 2920 uses a well-known edge detection technique to detect the position of the boundary on the virtual lines VL1 and VL2 shown in FIG. 11 , for example. Examples of well-known edge detection techniques that can be used include edge detection techniques using a Sobel filter, a Laplacian filter, a Canny filter, etc. The boundary position detection unit 2920 then stores position information indicating the position of the detected boundary in the boundary position storage unit 2937 in association with virtual line identification information that identifies the virtual lines VL1 and VL2. The boundary position detection unit 2920 also detects the position of the boundary for each of the captured images captured by the imaging unit 22 at a predetermined imaging period after the central portion of the substrate W2 comes into contact with the substrate W1, as indicated by the image information stored in the image storage unit 2931. Furthermore, the boundary position detection unit 2920 determines the time to start detecting the position of the boundary portion based on the point in time when the pressing unit 151 of the pressing mechanism 15 retreats to the outside of the projection area of ​​the substrates W1, W2 in the overlapping direction after bringing the central portion of the substrate W2 into contact with the substrate W1. Specifically, the boundary position detection unit 2920 selects, from the image information stored in the image storage unit 2931, image information indicating an image captured by the imaging unit 22 after the pressing unit 151 of the pressing mechanism 15 retreats to the outside of the projection area of ​​the substrates W1, W2 in the overlapping direction, and detects the position of the boundary portion described above only for the image indicated by the selected image information.

[0045] The movement speed measurement unit 2921 measures the movement speed of the boundary portion as it moves toward the periphery of the substrates W1, W2, based on the position information stored in the boundary position memory unit 2937. The movement speed measurement unit 2921 then chronologically stores movement speed information indicating the measured movement speed in the movement speed memory unit 2938. The stop position detection unit 2922 identifies as a stop position the position indicated by the position information stored in the boundary position memory unit 2937 when the movement speed measured by the movement speed measurement unit 2921 becomes 0, and stores stop position information indicating the identified stop position in the stop position memory unit 2939. Here, the stop position may be represented, for example, by the distance from the center of the substrates W1, W2 corresponding to the intersection of the virtual straight lines VL1, VL2.

[0046] The correspondence information generation unit 2923 generates correspondence information indicating at least two correspondences selected from the elapsed time from the point in time when the substrate holder 171 released support of the peripheral portion of the substrate W2 after the centers of the substrates W1 and W2 came into contact with each other, the movement speed of the boundary portion of the substrates W1 and W2, the stop position of the boundary portion, and virtual line identification information identifying the virtual line. Specifically, the correspondence information generation unit 2923 generates the correspondence information using the position information stored in the boundary position memory unit 2937, and any of the movement speed information stored in the movement speed memory unit 2938, the stop position information stored in the stop position memory unit 2939, the elapsed time information stored in the elapsed time memory unit 935, and the virtual line information identifying the virtual lines VL1 and VL2. The correspondence information generation unit 2923 then stores the generated correspondence information in the correspondence information memory unit 2936.

[0047] Next, a bonding state inspection method using the bonding state inspection device 2001 according to this embodiment will be described with reference to FIGS. 12 and 13 . Assume that the substrate W1 is already supported on the stage 2011, and the substrate W2 is supported by the three substrate holders 171 while spaced apart from the substrate W1. First, as shown in FIG. 12 , the pressing mechanism 15 presses the central portion of the substrate W2 toward the substrate W1 with the pressing portion 151, thereby bringing the central portions of the substrates W1 and W2 into contact with each other (step S201). Here, the pressing mechanism 15 first brings the pressing portion 151 into contact with the central portion of the substrate W2, as shown in FIG. 13A , and then lowers the pressing portion 151 toward the substrate W1, as indicated by arrow AR31 in FIG. 13B , thereby bringing the central portion of the substrate W2 into contact with the central portion of the substrate W1.

[0048] 12 , next, the holder driver 172 moves the substrate holder 171 in a direction away from the substrate W2, thereby releasing support for the substrate W2 (step S202). Here, the holder driver 172 releases support for the substrate W2 by moving the substrate holder 171 in a direction away from the periphery of the substrate W2, as indicated by arrow AR32 in Fig. 13C. As a result, the substrate W2 gradually comes into contact with the substrate W1 from the central portion thereof toward the periphery of the substrate W2, as indicated by arrow AR33.

[0049] 12 , the boundary position detection unit 2920 then detects the boundary between the bonded and peeled portions of the two substrates W1 and W2 using the captured images captured by the imaging unit 22. The boundary position detection unit 2920 then stores position information indicating the position of the detected boundary in the boundary position memory unit 2937 in association with virtual line identification information that identifies the virtual lines VL1 and VL2 (step S203). Thereafter, the movement speed measurement unit 2921 measures the movement speed of the boundary as it moves toward the periphery of the substrates W1 and W2, based on the position information stored in the boundary position memory unit 2937. The movement speed measurement unit 2921 then stores the measured movement speed information in the movement speed memory unit 2938 in chronological order (step S204). Next, the elapsed time measurement unit 916 measures the elapsed time after the center of the substrate W2 is brought into contact with the center of the substrate W1, and stores elapsed time information indicating the measured elapsed time in the elapsed time memory unit 935 in chronological order (step S205).

[0050] Next, the stop position detection unit 2922 determines whether the movement speed measured by the movement speed measurement unit 2921 has become 0 and the aforementioned boundary portion has stopped (step S206). Here, if the stop position detection unit 2922 determines that the movement speed measured by the movement speed measurement unit 2921 is not 0 and the aforementioned boundary portion has not yet stopped (step S206: No), the processing of step S203 is executed again. On the other hand, if the stop position detection unit 2922 determines that the movement speed measured by the movement speed measurement unit 2921 has become 0 and the boundary portion has stopped (step S206: Yes), the stop position detection unit 2922 identifies, as the stop position, the position indicated by the position information stored in the boundary position storage unit 2937 at the time when it was determined that the boundary portion had stopped, and stores stop position information indicating the identified stop position in the stop position storage unit 2939 (step S207).

[0051] Thereafter, the correspondence information generation unit 2923 generates correspondence information using the position information stored in the boundary position storage unit 2937 and any of the movement speed information stored in the movement speed storage unit 2938, the stop position information stored in the stop position storage unit 2939, the elapsed time information stored in the elapsed time storage unit 935, and the virtual line information identifying the virtual lines VL1 and VL2. Then, the correspondence information generation unit 2923 stores the generated correspondence information in the correspondence information storage unit 2936 (step S208).

[0052] In the bonding condition inspection method according to this embodiment, the bonding surfaces of wafer substrates W1 and W2 are activated by plasma treatment or particle beam irradiation, then the bonding surfaces are made hydrophilic by water cleaning, and the substrates W1 and W2 are then brought into contact at their central portions and bonded together. The activation state of the bonding surfaces is evaluated based on the wetting and spreading state of the substrates W1 and W2, the occurrence of voids, and the position at which the wetting and spreading stops. The activation state of the bonding surfaces of the substrates W1 and W2 can be evaluated in more detail by evaluating the correspondence between the elapsed time after the central portions of the substrates W1 and W2 were brought into contact, the moving speed of the boundary, the stopping position of the boundary, and the position, number, and size of voids generated between the two substrates W1 and W2. Furthermore, the cleaning state of the bonding surfaces of the substrates W1 and W2 can be evaluated based on the occurrence of voids.

[0053] As described above, according to the bonding state inspection device 2001 of this embodiment, when the substrate W2 is brought into contact with the substrate W1 from the center thereof, the boundary portion between the bonded and unbonded portions of the two substrates W1, W2, which changes over time, is continuously detected from the overlapping direction of the two substrates W1, W2, which are at least partially bonded together. This makes it possible to grasp the transient changes in the bonding state when the two substrates W1, W2 are bonded together, and therefore to analyze the bonding state of the two substrates W1, W2 in detail.

[0054] Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations of the aforementioned embodiments. For example, the bonding state inspection device described in embodiment 1 may have the functions of the bonding state inspection device described in embodiment 2. Specifically, as shown in FIG. 14 , a bonding state inspection device 3001 may include a stage 2011, a plurality of substrate holders 171, a holder driver 172, a pressing mechanism 15, and a control unit 3090, in addition to a stage 11, a rotation driver 14, a blade 121, a blade holder 122, a blade driver 13, an imaging unit 21, and a light source 23. Note that in FIG. 14 , the same components as those in the respective embodiments are denoted by the same reference numerals as in FIGS. 1 and 8 . Here, as indicated by arrow AR31, the stage 11 and the rotation driver 14 may be in a state where they are disposed at positions when performing the bonding state inspection method described in embodiment 1, or in a state where they are retracted to a position where they do not interfere with the pressing unit 151 when the pressing mechanism 15 abuts the pressing unit 151 on the center of the substrate W2 held by the plurality of substrate holders 171. As indicated by arrow AR32, imaging unit 21 can be disposed at either a position for carrying out the bonding state inspection method described in embodiment 1 or a position for carrying out the bonding state inspection method described in embodiment 2. Furthermore, control unit 3090 has the functions of both control units 90 and 2090 described in embodiments 1 and 2, respectively.

[0055] According to this configuration, two types of inspections can be performed with one bonding state inspection device 3009, thereby saving space compared to installing two bonding state inspection devices, one for each of the two types of inspections.

[0056] In each embodiment, the inspection object is not limited to the substrates W1 and W2, but may be any object to be bonded, including a wafer, a chip, or the like.

[0057] In the first embodiment, the gas supply unit 162 may supply a gas mixture of multiple types of gases with different moisture contents into the chamber 161. In this case, the gas supply unit 162 may be able to supply gas with a predetermined moisture content by adjusting the mixing ratio of the multiple types of gases, and the gas supply control unit 918 may be able to control the mixing ratio of the multiple types of gases.

[0058] In the first embodiment, chamber 161 may be provided with a temperature detection unit that detects the temperature inside chamber 161, and gas supply unit 162 may be provided with a temperature adjustment mechanism that adjusts the temperature of the gas supplied into chamber 161. Then, gas supply control unit 918 may control gas supply unit 162 so that the temperature detected by the temperature detection unit becomes a preset target temperature.

[0059] In embodiment 1, the device may include an imaging unit that images the edge of blade 121 from a direction perpendicular to the overlapping direction of substrates W1 and W2, and a blade holding unit overlapping direction driving unit that changes the position of the edge of blade 121 in the overlapping direction of substrates W1 and W2 by raising and lowering blade holding unit 122 and blade driving unit 123 together in the overlapping direction of substrates W1 and W2.

[0060] The first embodiment may also include a substrate holding unit that holds two long substrates bonded together. In this case, the bonding condition inspection device may move the imaging unit 21 or the substrate holding unit in accordance with the movement of the blade so as to maintain the relative positional relationship between the blade and the imaging unit 21. As shown in Figures 15A and 15B, the blade holding unit 4122 according to this modification holds the blade 4121 on the outside of both ends of the substrates W41 and W42 in the short direction. Note that in Figures 15A and 15B, components similar to those in the first embodiment are denoted by the same reference numerals as those in Figures 3A and 3B. Then, as shown in Figure 15B, when the blade 4121 is inserted between the substrates W41 as indicated by the arrow AR411, if the length L411 from the edge of the blade 4121 to the edge on one side of the substrates W41 and W42 where the blade 4121 is inserted in the longitudinal direction becomes longer than the length L412 from the edge of the blade 4121 to the position where the blade 4121 is held by the blade holding portion 122 on the blade 4121, then a bonding portion Po0 is present on one side of the longitudinal direction of the portion of the substrates W41 and W42 where the blade 4121 is inserted, and the non-bonding portion Po1 peeled off by the blade 4121 is positioned on the opposite side of the blade 4121 on the substrates W41 and W42 from the bonding portion Po0 side. Then, when the blade 4122 is brought even closer to the bonded portion Po0 of the substrates W41, W42, the non-bonded portion Po1 peeled off by the blade 4121 flows toward the opposite side of the bonded portion Po0 of the substrates W41, W42 from the blade 4121. Here, the bonding condition inspection device includes a substrate holder support portion (not shown) that supports a substrate holder corresponding to the shape of the substrates W41, W42.

[0061] According to this configuration, it is possible to inspect the bonding state of the substrates W41 and W42, which have a so-called rectangular shape.

[0062] In the first embodiment, an example has been described in which the blade elevation drive unit 17 raises and lowers the blade 121, blade holder 122, and blade drive unit 13 collectively based on a control signal input from the control unit 90. However, this is not limited to this, and the blade elevation drive unit 17 may have a gear mechanism connected to a handle that can be manually operated by a user, and when the user rotates the handle, the blade 121, blade holder 122, and blade drive unit 13 collectively raise and lower. Also, in the first embodiment, the rotation drive unit 14 may have a gear mechanism connected to a handle that can be manually operated by a user, and when the user rotates the handle, the stage 11 may rotate about the rotation axis J1 that aligns with the overlapping direction of the substrates W1 and W2 held on the stage 11.

[0063] In embodiment 1, stage 11 may further include a substrate holder support portion that interchangeably supports either a stage that is circular in plan view and can hold a disk-shaped wafer, or a long stage that can hold a long rectangular plate-shaped substrate.

[0064] In the first embodiment, the boundary portion identifying unit 919 may be configured to identify each of the boundary portions between bonded and non-bonded portions at a plurality of locations on the substrates W1 and W2 by analyzing images captured by the imaging unit 21 with the blade 121 inserted at each of the plurality of locations between the substrates W1 and W2. The bonding strength calculation unit 913 may then use the captured images to calculate, for each of the plurality of locations, a non-bonded portion distance between the edge of the blade 121 on the substrates W1 and W2 and the boundary portion, and calculate the bonding strength of the substrates W1 and W2 based on a representative value of the calculated non-bonded portion distances at each of the plurality of locations. Here, the representative value may be an average value, a median value, a maximum value, a minimum value, or the like.

[0065] In the second embodiment, the bonding state inspection device 2001 may include a void identification unit that identifies the position, number, and size of voids that have occurred between the substrates W1 and W2. Here, the void identification unit identifies the position, number, and size of the voids that have occurred based on, for example, image information showing a captured image of the substrates W1 and W2 in a bonded state, which is stored in the image storage unit 2931. In this case, the correspondence generation unit 2923 may generate correspondence information that indicates a correspondence relationship between at least two items selected from the elapsed time from the point in time when the support of the periphery of the substrate W2 by the substrate holder 171 was released after the centers of the substrates W1 and W2 came into contact with each other, the moving speed of the boundary portion of the substrates W1 and W2, the stopping position of the boundary portion, and the virtual line identification information that identifies the virtual line, as well as the position, number, and size of the voids that have occurred between the identified substrates W1 and W2.

[0066] In the second embodiment, the boundary position detection unit 2920 may detect the positions of the boundaries between the bonded and non-bonded portions of the substrates W1, W2 on a plurality of imaginary straight lines extending radially from the center of the substrates W1, W2. The movement speed measurement unit 2921 may detect the positions on the plurality of imaginary straight lines in synchronization with the detection of the boundary portions, thereby detecting the movement speeds of the boundaries on each imaginary straight line and calculating a representative value of the movement speeds corresponding to each of the plurality of imaginary straight lines. Here, the representative value may be an average value, a median value, a maximum value, a minimum value, or the like of the movement speeds corresponding to each of the plurality of imaginary straight lines.

[0067] Furthermore, in the second embodiment, the boundary position detection unit 2920 may detect the positions of the boundaries between the bonded and non-bonded portions of the substrates W1, W2 on a plurality of imaginary straight lines extending radially from the center of the substrates W1, W2, and the stop position detection unit 2922 may calculate a representative value of the positions of the boundary portions where the substrates have stopped on each of the plurality of imaginary straight lines. Here, the representative value may be an average value, a median value, a maximum value, a minimum value, or the like of the stop positions corresponding to each of the plurality of imaginary straight lines.

[0068] The present invention allows various embodiments and modifications without departing from the broad spirit and scope of the present invention. Furthermore, the above-described embodiments are intended to illustrate the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and the meaning of the invention equivalent thereto are considered to be within the scope of the present invention.

[0069] This application is based on Japanese Patent Application No. 2024-077939, filed on May 13, 2024. The entire specification, claims and drawings of Japanese Patent Application No. 2024-077939 are incorporated herein by reference.

[0070] The present invention is suitable for evaluating the bonding strength between substrates in the manufacturing process of, for example, CMOS (Complementary MOS) image sensors, memories, computing elements, and MEMS (Micro Electro Mechanical Systems).

[0071] 1, 2001, 3001: Bonding state device, 11, 2011: Stage, 11a, 2011a: Mounting surface, 13: Blade driving unit, 14: Pressure sensor, 15: Pressing mechanism, 21, 22: Imaging unit, 23: Light source, 90, 2090: Control unit, 121: Blade, 122: Blade holding unit, 123: Arm, 131: Slider driving unit, 132: Slider, 151: Pressing unit, 152: Elevation driving unit, 153: Horizontal driving unit, 161: Chamber, 162: Gas supply unit, 163: Humidity sensor, 171: Support piece, 172: Support piece driving unit, 241: Reflection plate, 242: Light diffusion plate, 911: Blade control unit, 912, 2912: Image Acquisition unit, 913: bonding strength calculation unit, 914: insertion amount measurement unit, 915: pressing force measurement unit, 916: elapsed time measurement unit, 917, 2923: correspondence relationship information generation unit, 918: gas supply unit control unit, 919: boundary portion identification unit, 2919: pressing force control unit, 2920: boundary position detection unit, 2921: movement speed measurement unit, 2922: stop position detection unit, 931, 2931: image storage unit, 932: bonding strength storage unit, 933: insertion amount storage unit, 934: pressing force storage unit, 935: elapsed time storage unit, 936, 2936: correspondence relationship information storage unit, 2937: boundary position storage unit, 2938: movement speed storage unit, 2939: stop position storage unit, W1, W2: substrate

Claims

1. The method involves continuously detecting the boundary between the bonded and unbonded portions of two substrates that are joined at least partially, from the direction of superposition of the two substrates, and calculating the bonding strength of the two substrates based on the boundary each time the boundary is detected. Joint condition inspection device.

2. A first substrate holding section that holds the two substrates, A blade holder that holds a portion of the plate-shaped blade, A blade drive unit drives the blade holding unit from the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates so that the edge of the blade is inserted between the two substrates, A first imaging unit that images a region including the edge of the blade from the direction in which the two substrates are superimposed, With the blade inserted between the two substrates, the boundary portion identification unit identifies the boundary portion between the bonded portion and the non-bonded portion of the two substrates by analyzing the captured image taken by the first imaging unit, The system includes a bonding strength calculation unit that calculates the non-bonding distance between the blade and the boundary portion on the two substrates using the captured image, and calculates the bonding strength of the two substrates based on the calculated non-bonding distance. The joint condition inspection apparatus according to claim 1.

3. The first imaging unit uses infrared light to image at least the boundary portion. The joint condition inspection apparatus according to claim 2.

4. The system further includes an insertion amount measuring unit that measures the amount of insertion of the blade between the two substrates in synchronization with the detection of the boundary portion. The joint condition inspection apparatus according to claim 2 or 3.

5. A first substrate holding portion that holds two substrates joined at least in part, A blade holder that holds a portion of the plate-shaped blade, A blade drive unit drives the blade holding unit from the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates so that the edge of the blade is inserted between the two substrates, A first imaging unit that images a region including the edge of the blade from the direction in which the two substrates are superimposed, With the blade inserted between the two substrates, the first imaging unit analyzes the captured image to identify the boundary portion between the two substrates, which changes over time, between the bonded portions and the unbonded portions of the two substrates. The system includes a bonding strength calculation unit that calculates the non-bonding distance between the blade and the boundary portion on the two substrates using the captured image, and calculates the bonding strength of the two substrates based on the calculated non-bonding distance. The boundary portion, which changes over time, is continuously detected from the superposition direction of two substrates that are joined at least partially. The system further includes a pressing force measuring unit that, in synchronization with the continuous detection of the boundary portion, measures the pressing force applied to the blade when inserting the blade between the two substrates. Joint condition inspection device.

6. A first substrate holding portion that holds two substrates joined at least in part, A blade holder that holds a portion of the plate-shaped blade, A blade drive unit drives the blade holding unit from the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates so that the edge of the blade is inserted between the two substrates, A first imaging unit that images a region including the edge of the blade from the direction in which the two substrates are superimposed, With the blade inserted between the two substrates, the first imaging unit analyzes the captured image to identify the boundary portion between the two substrates, which changes over time, between the bonded portions and the unbonded portions of the two substrates. The system includes a bonding strength calculation unit that calculates the non-bonding distance between the blade and the boundary portion on the two substrates using the captured image, and calculates the bonding strength of the two substrates based on the calculated non-bonding distance. The boundary portion, which changes over time, is continuously detected from the superposition direction of two substrates that are joined at least partially. The system further includes an elapsed time measurement unit that measures the elapsed time after the blade has been inserted between the two substrates, in synchronization with the continuous detection of the boundary portion. Joint condition inspection device.

7. A first substrate holding portion that holds two substrates joined at least in part, A blade holder that holds a portion of the plate-shaped blade, A blade drive unit drives the blade holding unit from the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates so that the edge of the blade is inserted between the two substrates, A first imaging unit that images a region including the edge of the blade from the direction in which the two substrates are superimposed, With the blade inserted between the two substrates, the first imaging unit analyzes the captured image to identify the boundary portion between the two substrates, which changes over time, between the bonded portions and the unbonded portions of the two substrates. The system includes a bonding strength calculation unit that calculates the non-bonding distance between the blade and the boundary portion on the two substrates using the captured image, and calculates the bonding strength of the two substrates based on the calculated non-bonding distance. The boundary portion, which changes over time, is continuously detected from the superposition direction of two substrates that are joined at least partially. An insertion amount measuring unit that measures the amount of insertion of the blade between the two substrates in synchronization with the detection of the boundary portion, A pressing force measuring unit that measures the pressing force applied to the blade when inserting the blade between the two substrates, in synchronization with the continuous detection of the boundary portion, A time elapsed measurement unit measures the elapsed time after the blade is inserted between the two substrates, in synchronization with the continuous detection of the boundary portion. The system further comprises a correspondence information generation unit that generates correspondence information indicating at least two correspondences selected from the bonding strength of the two substrates, the insertion amount, the pressing force, and the elapsed time. Joint condition inspection device.

8. A bonding state inspection device that continuously detects the boundary portion between the bonded portion and the unbonded portion of two substrates that are bonded together at least in part, from the direction of superposition of two substrates that are bonded together at least in part, and which changes over time, The region where the two substrates are placed, at least the boundary portion of which is located, is maintained at a predetermined target humidity. Joint condition inspection device.

9. A first substrate holding portion that holds the two substrates, A blade holder that holds a portion of the plate-shaped blade, A blade drive unit drives the blade holding unit from the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates so that the edge of the blade is inserted between the two substrates, A first imaging unit that images a region including the edge of the blade from the direction in which the two substrates are superimposed, With the blade inserted between the two substrates, the boundary portion identification unit identifies the boundary portion between the bonded portion and the non-bonded portion of the two substrates by analyzing the captured image taken by the first imaging unit, A bonding strength calculation unit calculates the non-bonding distance between the blade and the boundary portion on the two substrates using the captured image, and calculates the bonding strength of the two substrates based on the calculated non-bonding distance. With the blade inserted between the two substrates, a chamber is provided that covers at least the region including the edge of the blade and at least a portion of the two substrates. The system includes a gas supply unit that supplies gas into the chamber, thereby causing the gas to flow from inside the chamber to outside the chamber. The bonding condition inspection apparatus according to claim 8.

10. The chamber further comprises a humidity sensor for measuring the humidity inside the chamber. The bonding condition inspection apparatus according to claim 9.

11. The system includes a gas supply control unit that controls the gas supply unit so that the humidity detected by the humidity sensor reaches a preset target humidity. The bonding condition inspection device according to claim 10.

12. The aforementioned gas is a mixture of multiple types of gases with different water content. The gas supply unit supplies gas with a predetermined water content by adjusting the mixing ratio of multiple types of gases. The gas supply control unit controls the mixing ratio. The bonding condition inspection device according to claim 11.

13. A bonding state inspection device that continuously detects the boundary portion between the bonded portion and the unbonded portion of two substrates that are bonded together at least in part, from the direction of superposition of two substrates that are bonded together at least in part, and which changes over time, The region where the two substrates are placed, at least the boundary portion of which is located, is maintained at a predetermined target temperature. Joint condition inspection device.

14. A first substrate holding portion that holds the two substrates, A blade holder that holds a portion of the plate-shaped blade, A blade drive unit drives the blade holding unit from the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates so that the edge of the blade is inserted between the two substrates, A first imaging unit that images a region including the edge of the blade from the direction in which the two substrates are superimposed, With the blade inserted between the two substrates, the boundary portion identification unit identifies the boundary portion between the bonded portion and the non-bonded portion of the two substrates by analyzing the captured image taken by the first imaging unit, A bonding strength calculation unit calculates the non-bonding distance between the blade and the boundary portion on the two substrates using the captured image, and calculates the bonding strength of the two substrates based on the calculated non-bonding distance. With the blade inserted between the two substrates, a chamber is provided that covers at least the region including the edge of the blade and at least a portion of the two substrates. A gas supply unit that supplies gas into the chamber so that gas flows from inside the chamber to outside the chamber, A temperature detection unit for detecting the temperature inside the chamber, The system includes a gas supply control unit that adjusts the temperature of the gas supplied from the gas supply unit so that the temperature detected by the temperature detection unit becomes a preset target temperature. The joint condition inspection apparatus according to claim 13.

15. The system further comprises at least one of the following: a humidity detection unit that detects the humidity in the area where at least the boundary portion is located at the location where the two substrates are arranged, and a humidity transition measurement unit that measures the change in humidity in synchronization with the continuous detection of the boundary portion; a temperature detection unit that detects the temperature in the area where at least the boundary portion is located at the location where the two substrates are arranged, and a temperature transition measurement unit that measures the change in temperature in synchronization with the continuous detection of the boundary portion; The correspondence relationship information generation unit generates correspondence relationship information that shows at least two correspondence relationships selected from the bonding strength of the two substrates, the insertion amount, the pressing force, the elapsed time, and at least one of the humidity and the temperature. The joint condition inspection apparatus according to claim 7.

16. A first substrate holding portion that holds two substrates joined at least in part, A blade holder that holds a portion of the plate-shaped blade, A blade drive unit drives the blade holding unit from the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates so that the edge of the blade is inserted between the two substrates, A first imaging unit that images a region including the edge of the blade from the direction in which the two substrates are superimposed, With the blade inserted between the two substrates, the first imaging unit analyzes the captured image to identify the boundary portion between the two substrates, which changes over time, between the bonded portions and the unbonded portions of the two substrates. A bonding strength calculation unit calculates the non-bonding distance between the blade and the boundary portion on the two substrates using the captured image, and calculates the bonding strength of the two substrates based on the calculated non-bonding distance. A second imaging unit captures the edge of the blade from a direction perpendicular to the superposition direction of the two substrates, The blade holding portion is driven in the direction of the superposition of the two substrates, thereby changing the position of the edge of the blade in the direction of the superposition of the two substrates. The boundary portion, which changes over time, is continuously detected from the superposition direction of two substrates that are joined at least partially. Joint condition inspection device.

17. A first substrate holding portion that holds two substrates joined at least in part, A blade holder that holds a portion of the plate-shaped blade, A blade drive unit drives the blade holding unit from the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates so that the edge of the blade is inserted between the two substrates, A first imaging unit that images a region including the edge of the blade from the direction in which the two substrates are superimposed, With the blade inserted between the two substrates, the first imaging unit analyzes the captured image to identify the boundary portion between the two substrates, which changes over time, between the bonded portions and the unbonded portions of the two substrates. A bonding strength calculation unit calculates the non-bonding distance between the blade and the boundary portion on the two substrates using the captured image, and calculates the bonding strength of the two substrates based on the calculated non-bonding distance. A rotational drive unit that rotates the first substrate holder around a rotation axis along the direction of superposition of the two substrates held by the first substrate holder, The first substrate holder, which holds the two substrates, is rotated by a specified rotation angle from a preset reference position, and the blade is inserted between the two substrates. The image storage unit stores image information representing the captured image captured by the first imaging unit, corresponding to the rotation angle. The boundary portion, which changes over time, is continuously detected from the superposition direction of two substrates that are joined at least partially. The bonding strength calculation unit calculates the non-bonded portion distance corresponding to each of the rotation angles using each of the captured images indicated by the image information stored in the image storage unit, and calculates the bonding strength of the two substrates based on the calculated non-bonded portion distances. Joint condition inspection device.

18. A light source positioned vertically below the first substrate holding portion, A reflector that reflects light from the light source toward the two substrates, The system further comprises a light diffuser plate that diffuses the light reflected by the reflector plate. The joint condition inspection apparatus according to claim 2 or 3.

19. A first substrate holding portion that holds two substrates joined at least in part, A blade holder that holds a portion of the plate-shaped blade, A blade drive unit drives the blade holding unit from the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates so that the edge of the blade is inserted between the two substrates, A first imaging unit that images a region including the edge of the blade from the direction in which the two substrates are superimposed, With the blade inserted between the two substrates, the first imaging unit analyzes the captured image to identify the boundary portion between the two substrates, which changes over time, between the bonded portions and the unbonded portions of the two substrates. The system includes a bonding strength calculation unit that calculates the non-bonding distance between the blade and the boundary portion on the two substrates using the captured image, and calculates the bonding strength of the two substrates based on the calculated non-bonding distance. The boundary portion, which changes over time, is continuously detected from the superposition direction of two substrates that are joined at least partially. The boundary portion identification unit identifies each of the boundary portions between the bonded portion and the non-bonded portion at each of the multiple locations between the two substrates by analyzing the captured images taken by the first imaging unit with the blade inserted at each of the multiple locations between the two substrates. The bonding strength calculation unit calculates the non-bonding distance between the blade and the boundary portion on the two substrates for each of the multiple locations using the captured image, and calculates the bonding strength of the two substrates based on the representative value of the non-bonding distance at each of the multiple locations calculated. Joint condition inspection device.

20. A second substrate holding portion that holds two substrates joined at least in part in a spaced-out manner, A pressing mechanism that presses the central portion of at least one of the two substrates toward the other, thereby bringing the central portion of one substrate into contact with the other; The system includes a boundary position detection unit that simultaneously detects the position of the boundary portion between the bonded portion and the unbonded portion of the two substrates on a plurality of virtual lines extending radially from the central portion of the two substrates, The boundary portion that changes over time is continuously detected from the direction of superposition of the two substrates. Joint condition inspection device.

21. A second substrate holding portion that holds two substrates joined at least in part in a spaced-out manner, A pressing mechanism that presses the central portion of at least one of the two substrates toward the other, thereby bringing the central portion of one substrate into contact with the other; The device includes a boundary position detection unit that detects the position of the boundary portion between the joined portions and unjoined portions of the two substrates on at least one virtual straight line extending radially from the central portion of the two substrates, The pressing mechanism is, A pressing portion that contacts at least one of the two substrates, An overlapping direction drive unit that, while the pressing portion is in contact with the center of at least one of the two substrates, moves the pressing portion in the overlapping direction of the two substrates, thereby pressing one substrate toward the other, and bringing the center of one substrate into contact with the other; The horizontal drive unit, after bringing the central portion of one of the substrates into contact with the other, moves the pressing portion in a direction perpendicular to the overlapping direction of the two substrates, thereby retracting it to the outside of the projection area of ​​the two substrates in the overlapping direction, The boundary portion that changes over time is continuously detected from the direction of superposition of the two substrates. Joint condition inspection device.

22. The boundary position detection unit determines the timing for starting the detection of the boundary portion's position based on the point in time when the pressing portion retracts to the outside of the projection area. The joint condition inspection device according to claim 21.

23. A second substrate holding portion that holds two substrates joined at least in part in a spaced-out manner, A pressing mechanism that presses the central portion of at least one of the two substrates toward the other, thereby bringing the central portion of one substrate into contact with the other; The device includes a boundary position detection unit that detects the position of the boundary portion between the joined portions and unjoined portions of the two substrates on at least one virtual straight line extending radially from the central portion of the two substrates, The boundary portion that changes over time is continuously detected from the direction of superposition of the two substrates. The device further includes an elapsed time measuring unit that, after bringing the central portion of one device into contact with the other, continuously detects the boundary portion and, in synchronization with that detection, detects the elapsed time. Joint condition inspection device.

24. A second substrate holding portion that holds two substrates joined at least in part in a spaced-out manner, A pressing mechanism that presses the central portion of at least one of the two substrates toward the other, thereby bringing the central portion of one substrate into contact with the other; The device includes a boundary position detection unit that detects the position of the boundary portion between the joined portions and unjoined portions of the two substrates on at least one virtual straight line extending radially from the central portion of the two substrates, The boundary portion that changes over time is continuously detected from the direction of superposition of the two substrates. The system further includes a movement speed measuring unit that detects the movement speed of the boundary portion in synchronization with the continuous detection of the boundary portion. Joint condition inspection device.

25. A second substrate holding portion that holds two substrates joined at least in part in a spaced-out manner, A pressing mechanism that presses the central portion of at least one of the two substrates toward the other, thereby bringing the central portion of one substrate into contact with the other; A boundary position detection unit for detecting the position of the boundary portion between the bonded portion and the unbonded portion of the two substrates on at least one virtual straight line extending radially from the central portion of the two substrates, The system includes a void identification unit that identifies the location, number, and size of voids that occur between the two substrates, The boundary portion that changes over time is continuously detected from the direction of superposition of the two substrates. Joint condition inspection device.

26. A second substrate holding portion that holds two substrates joined at least in part in a spaced-out manner, A pressing mechanism that presses the central portion of at least one of the two substrates toward the other, thereby bringing the central portion of one substrate into contact with the other; A boundary position detection unit for detecting the position of the boundary portion between the bonded portion and the unbonded portion of the two substrates on at least one virtual straight line extending radially from the central portion of the two substrates, The system includes a stop position detection unit that detects the position of the stopped boundary portion when the detected boundary portion's position stops, The boundary portion that changes over time is continuously detected from the direction of superposition of the two substrates. Joint condition inspection device.

27. ​​A second substrate holding portion that holds two substrates joined at least in part in a spaced-out manner, A pressing mechanism that presses the central portion of at least one of the two substrates toward the other, thereby bringing the central portion of one substrate into contact with the other; The device includes a boundary position detection unit that detects the position of the boundary portion between the joined portions and unjoined portions of the two substrates on at least one virtual straight line extending radially from the central portion of the two substrates, The boundary portion that changes over time is continuously detected from the direction of superposition of the two substrates. After bringing the central portion of one of the units into contact with the other, the elapsed time measurement unit detects the elapsed time in synchronization with the continuous detection of the boundary portion, A moving speed measuring unit that measures the moving speed of the boundary portion in synchronization with the continuous detection of the boundary portion, When the detected boundary portion stops, a stop position detection unit detects the stop position of the boundary portion, A void identification unit that identifies the location, number, and size of voids that occur between the two substrates, The system further comprises a correspondence relationship information generation unit that generates correspondence relationship information indicating at least two correspondence relationships selected from the elapsed time, the moving speed, the stopping position, virtual line identification information that identifies each of the at least one virtual line, and the position, number, and size of voids generated between the two substrates. Joint condition inspection device.

28. The boundary position detection unit detects the position of the boundary portion of the two substrates on each of a plurality of virtual lines that radiate from the central portion of the two substrates, The moving speed measuring unit detects the moving speed of the boundary portion by detecting its position on a plurality of virtual lines in synchronization with the detection of the boundary portion, and calculates a representative value of the moving speed corresponding to each of the plurality of virtual lines. The bonding condition inspection device according to claim 24.

29. The boundary position detection unit detects the position of the boundary portion of the two substrates on each of a plurality of virtual lines that radiate from the central portion of the two substrates, The stop position detection unit calculates a representative value of the position of the boundary portion where the stop occurred on each of the plurality of virtual lines. The joint condition inspection apparatus according to claim 26.

30. A second substrate holding portion that holds two substrates joined at least in part in a spaced-out manner, A pressing mechanism that presses the central portion of at least one of the two substrates toward the other, thereby bringing the central portion of one substrate into contact with the other; A boundary position detection unit for detecting the position of the boundary portion between the bonded portion and the unbonded portion of the two substrates on at least one virtual straight line extending radially from the central portion of the two substrates, A third substrate holding section that holds the two substrates, A blade holder that holds a portion of the plate-shaped blade, A blade drive unit drives the blade holding unit from the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates so that the edge of the blade is inserted between the two substrates, A first imaging unit that images a region including the edge of the blade from the direction in which the two substrates are superimposed, With the blade inserted between the two substrates, the boundary portion identification unit identifies the boundary portion between the bonded portion and the non-bonded portion of the two substrates by analyzing the captured image taken by the first imaging unit, The system includes a bonding strength calculation unit that calculates the non-bonding distance between the blade and the boundary portion on the two substrates using the captured image, and calculates the bonding strength of the two substrates based on the calculated non-bonding distance. The boundary portion that changes over time is continuously detected from the direction of superposition of the two substrates. The pressing mechanism has a pressing portion that contacts at least one of the two substrates, The third substrate holding portion can be retracted to a position where it does not interfere with the pressing portion when the pressing mechanism brings the pressing portion into contact with the central portion of the second substrate holding portion. Joint condition inspection device.

31. A first substrate holding portion that holds two substrates joined at least in part, A blade holder that holds a portion of the plate-shaped blade, A blade drive unit drives the blade holding unit from the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates so that the edge of the blade is inserted between the two substrates, A first imaging unit that images a region including the edge of the blade from the direction in which the two substrates are superimposed, With the blade inserted between the two substrates, the first imaging unit analyzes the captured image to identify the boundary portion between the two substrates, which changes over time, between the bonded portions and the unbonded portions of the two substrates. The system includes a bonding strength calculation unit that calculates the non-bonding distance between the blade and the boundary portion on the two substrates using the captured image, and calculates the bonding strength of the two substrates based on the calculated non-bonding distance. To maintain the relative positional relationship between the blade and the first imaging unit, the first imaging unit is moved in accordance with the movement of the blade, or the first substrate holding unit is moved. From the direction of superposition of the two substrates, the boundary portion between the bonded and unbonded portions of the two substrates, which changes over time, is continuously detected. Joint condition inspection device.

32. The first substrate holding portion holds two long substrates that are joined together. The joint condition inspection device according to claim 31.

33. The blade holding portion holds the blade on the outside of both ends in the short direction of the two substrates, The bonding portion is located on one side in the longitudinal direction of the portion in which the blade is inserted in the two substrates, and the non-bonded portion peeled off by the blade flows toward the side of the two substrates opposite to the bonding portion side from the blade. The joint condition inspection device according to claim 32.

34. A first substrate holding portion that holds two substrates joined at least in part, A blade holder that holds a portion of the plate-shaped blade, A blade drive unit drives the blade holding unit from the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates so that the edge of the blade is inserted between the two substrates, A first imaging unit that images a region including the edge of the blade from the direction in which the two substrates are superimposed, With the blade inserted between the two substrates, the first imaging unit analyzes the captured image to identify the boundary portion between the two substrates, which changes over time, between the bonded portions and the unbonded portions of the two substrates. The system includes a bonding strength calculation unit that calculates the non-bonding distance between the blade and the boundary portion on the two substrates using the captured image, and calculates the bonding strength of the two substrates based on the calculated non-bonding distance. The boundary portion, which changes over time, is continuously detected from the superposition direction of two substrates that are joined at least partially. The system further includes a substrate holding support that interchangeably supports any of the multiple types of first substrate holding parts corresponding to the shapes of the two substrates. Joint condition inspection device.

35. A second substrate holding portion that holds two substrates joined at least in part in a spaced-out manner, A pressing mechanism that presses the central portion of at least one of the two substrates toward the other, thereby bringing the central portion of one substrate into contact with the other; A boundary position detection unit for detecting the position of the boundary portion between the bonded portion and the unbonded portion of the two substrates on at least one virtual straight line extending radially from the central portion of the two substrates, A first substrate holding section that holds the two substrates, A blade holder that holds a portion of the plate-shaped blade, A blade drive unit drives the blade holding unit from the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates so that the edge of the blade is inserted between the two substrates, A first imaging unit that images a region including the edge of the blade from the direction in which the two substrates are superimposed, A bonding strength calculation unit calculates the non-bonding distance between the blades on the two substrates and the boundary portions on the two substrates using the captured image captured by the first imaging unit, and calculates the bonding strength of the two substrates based on the calculated non-bonding distance. The system includes a substrate holding support portion that interchangeably supports any of the multiple types of first substrate holding portions corresponding to the shapes of the two substrates, The boundary portion that changes over time is continuously detected from the direction of superposition of the two substrates. Joint condition inspection device.

36. A first substrate holder that holds two substrates, A blade holder that holds a portion of the plate-shaped blade, A blade drive unit drives the blade holding unit from the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates so that the edge of the blade is inserted between the two substrates, A first imaging unit that images a region including the edge of the blade from the direction in which the two substrates are superimposed, With the blade inserted between the two substrates, the boundary portion identification unit analyzes the image captured by the first imaging unit to identify the boundary portion between the bonded portion and the unbonded portion of the two substrates, The system includes a bonding strength calculation unit that calculates the non-bonding distance between the blade and the boundary portion on the two substrates using the captured image, and calculates the bonding strength of the two substrates based on the calculated non-bonding distance. The region where the two substrates are arranged, at least the boundary portion of which is located, is maintained at at least one of a preset target humidity and a preset target temperature. Joint condition inspection device.

37. The method involves continuously detecting the boundary between the bonded and unbonded portions of two substrates that are joined at least partially, from the direction of superposition of the two substrates, and calculating the bonding strength of the two substrates based on the boundary each time the boundary is detected. Method for inspecting the condition of the joints.

38. From the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates, with the edge of the blade inserted between the two substrates, at least the boundary portion of the two substrates is imaged from the overlapping direction of the two substrates while the blade is inserted between the two substrates, and the imaged image is analyzed to identify the boundary portion between the bonded portion and the non-bonded portion of the two substrates, calculate the distance between the blade on the two substrates and the identified boundary portion, and calculate the bonding strength of the two substrates based on the distance. The method for inspecting the bonding state according to claim 37.

39. A method for inspecting the bonding state of two substrates that are bonded at least in part, by continuously detecting the boundary portion between the bonded portion and the unbonded portion of the two substrates that changes over time, from the direction of superposition of the two substrates, From the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates, with the edge of the blade inserted between the two substrates, at least the boundary portion of the two substrates is imaged from the overlapping direction of the two substrates while the blade is inserted between the two substrates, and the imaged image is analyzed to identify the boundary portion between the bonded portion and the non-bonded portion of the two substrates, calculate the distance between the blade on the two substrates and the identified boundary portion, and calculate the bonding strength of the two substrates based on the distance. The gas is supplied to the location where the two substrates are placed such that the humidity in the area where at least the boundary portion of the two substrates is located reaches a predetermined target humidity. Method for inspecting the condition of the joints.

40. A method for inspecting the bonding state of two substrates that are bonded at least in part, by continuously detecting the boundary portion between the bonded portion and the unbonded portion of the two substrates that changes over time, from the direction of superposition of the two substrates, From the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates, with the edge of the blade inserted between the two substrates, at least the boundary portion of the two substrates is imaged from the overlapping direction of the two substrates while the blade is inserted between the two substrates, and the imaged image is analyzed to identify the boundary portion between the bonded portion and the non-bonded portion of the two substrates, calculate the distance between the blade on the two substrates and the identified boundary portion, and calculate the bonding strength of the two substrates based on the distance. In sync with continuously detecting the boundary portion, the amount of insertion of the blade between the two substrates is measured. In sync with continuously detecting the boundary portion, the pressing force applied to the blade when inserting it between the two substrates is measured. In sync with continuously detecting the boundary portion, the elapsed time after inserting the blade between the two substrates is measured, The system generates correspondence information indicating at least two correspondences selected from the bonding strength of the two substrates, the insertion amount, the pressing force, and the elapsed time. Method for inspecting the condition of the joints.

41. A method for inspecting the bonding state of two substrates that are bonded at least in part, by continuously detecting the boundary portion between the bonded portion and the unbonded portion of the two substrates that changes over time, from the direction of superposition of the two substrates, From the outside of the two substrates in a direction perpendicular to the overlapping direction of the two substrates, with the edge of the blade inserted between the two substrates, at least the boundary portion of the two substrates is imaged from the overlapping direction of the two substrates while the blade is inserted between the two substrates, and the imaged image is analyzed to identify the boundary portion between the bonded portion and the non-bonded portion of the two substrates, calculate the distance between the blade on the two substrates and the identified boundary portion, and calculate the bonding strength of the two substrates based on the distance. In sync with continuously detecting the boundary portion, the amount of insertion of the blade between the two substrates is measured. In sync with continuously detecting the boundary portion, the pressing force applied to the blade when inserting it between the two substrates is measured. In sync with continuously detecting the boundary portion, the elapsed time after inserting the blade between the two substrates is measured. At least one of the following is performed: continuously detecting the boundary portion and, in synchronization with that, measuring the humidity change in at least the region where the boundary portion is located at the location where the two substrates are placed; and continuously detecting the boundary portion and, in synchronization with that, measuring the temperature change in at least the region where the boundary portion is located at the location where the two substrates are placed. The system generates correspondence information indicating at least two correspondences selected from the bonding strength of the two substrates, the insertion amount, the pressing force, the elapsed time, and at least one of the humidity and the temperature. Method for inspecting the condition of the joint.

42. A method for inspecting the bonding state of two substrates that are bonded at least in part, by continuously detecting the boundary portion between the bonded portion and the unbonded portion of the two substrates that changes over time, from the direction of superposition of the two substrates, The two substrates are held spaced apart from each other, and the central portion of at least one of the two substrates is pressed toward the other, thereby bringing the central portion of one substrate into contact with the other. The position of the boundary portion of the two substrates on a plurality of virtual lines extending radially from the central portions of the two substrates is detected simultaneously. Method for inspecting the condition of the joint.

43. A method for inspecting the bonding state of two substrates that are bonded at least in part, by continuously detecting the boundary portion between the bonded portion and the unbonded portion of the two substrates that changes over time, from the direction of superposition of the two substrates, The two substrates are held spaced apart from each other, and the central portion of at least one of the two substrates is pressed toward the other, thereby bringing the central portion of one substrate into contact with the other. The position of the boundary portion of the two substrates on at least one virtual straight line extending radially from the central portions of the two substrates is then detected. In sync with continuously detecting the boundary portion, the elapsed time after the central portion of one object is brought into contact with the other object and the holding of one object is released is detected. In sync with continuously detecting the boundary portion, the moving speed of the boundary portion is measured. When the detected boundary portion stops, the stopping position of the boundary portion is detected. After identifying the location, number, and size of the voids that occurred between the two substrates, The system generates correspondence information indicating at least two correspondences selected from the following: the elapsed time, the moving speed, the stopping position, virtual line identification information that identifies each of the at least one virtual line, and the position, number, and size of the voids that occurred between the two substrates. Method for inspecting the condition of the joints.