Joint condition inspection device and joint condition 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

Technical Field

[0006] , , ,

[0005] , ,

[0001] The present invention relates to a joint state inspection apparatus and a joint state inspection method.

Background Art

[0002] As a method for evaluating the bonding strength between two substrates bonded to each other, there is provided a so-called crack and opening method for evaluating the bonding strength based on the length from the substrate periphery of the boundary between the peeled portion and the bonded portion when a blade is inserted between the two substrates bonded to each other with a preset pressing force (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when implementing the crack and opening method described in Patent Document 1, it is required to more detailedly analyze the joint state of the two substrates by observing the temporal change of the boundary between the peeled portion and the bonded portion immediately after inserting the blade between the two substrates. <​​​​​​​​​​From the superposition direction of two substrates that are joined at least partially, the boundary portion between the joined and unjoined portions of the two substrates, which changes over time, is continuously detected. In addition, each time the boundary portion is detected, the bonding strength of the two substrates is calculated based on the boundary portion. do.

[0007] From another perspective, the bonding state inspection method according to the present invention is: From the superposition direction of two substrates that are joined at least partially, the boundary portion between the joined and unjoined portions of the two substrates, which changes over time, is continuously detected. In addition, each time the boundary portion is detected, the bonding strength of the two substrates is calculated based on the boundary portion. do. [Effects of the Invention]

[0008] According to the present invention, the boundary portion between the bonded and unbonded portions of two substrates, which changes over time, is continuously detected from the superposition direction of two substrates that are at least partially bonded. This makes it possible to understand the influence of the aforementioned boundary portion's influence on the time-dependent changes in the bonding state of the two substrates, and thus enables a detailed analysis of the bonding state of the two substrates. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram of a bonding condition inspection device according to Embodiment 1 of the present invention. [Figure 2] This is a schematic side view showing a part of the joint condition inspection device according to Embodiment 1. [Figure 3A] This is a schematic plan view showing a part of the joint condition inspection device according to Embodiment 1. [Figure 3B] This is a schematic cross-sectional view showing a part of the bonding condition inspection device according to Embodiment 1. [Figure 4] This is a block diagram showing the functional configuration of the control unit according to Embodiment 1. [Figure 5] This is an explanatory diagram of the operation of the joint condition inspection device according to Embodiment 1. [Figure 6] This is a flowchart showing the joint condition inspection method performed by the joint condition inspection device according to Embodiment 1. [Figure 7A] It is a diagram showing the correspondence between the bonding strength of two substrates and the insertion amount of a blade among the inspection results by the bonding state inspection apparatus according to Embodiment 1. [Figure 7B] It is a diagram showing the correspondence between the bonding strength of two substrates and the pressing force when inserting a blade among the inspection results by the bonding state inspection apparatus according to Embodiment 1. [Figure 7C] It is a diagram showing the correspondence between the bonding strength of two substrates and the elapsed time from the start of insertion of a blade among the inspection results by the bonding state inspection apparatus according to Embodiment 1. [Figure 8] It is a schematic configuration diagram of the bonding state inspection apparatus according to Embodiment 2 of the present invention. [Figure 9A] It is a schematic cross-sectional view showing a part of the bonding state inspection apparatus according to Embodiment 2. [Figure 9B] It is a schematic plan view showing a part of the bonding state inspection apparatus according to Embodiment 2. [Figure 10] It is a block diagram showing the functional configuration of the control unit according to Embodiment 2. [Figure 11] It is an operation explanatory diagram of the bonding state inspection apparatus according to Embodiment 2. [Figure 12] It is a flowchart showing the bonding state inspection method executed by the bonding state inspection apparatus according to Embodiment 2. [Figure 13A] It is a diagram showing a state in which a pressing part is in contact with one of two substrates of the bonding state inspection apparatus according to Embodiment 2. [Figure 13B] It is a diagram showing a state in which one of two substrates of the bonding state inspection apparatus according to Embodiment 2 is pressed and brought into contact with the other. [Figure 13C] It is a diagram showing a state immediately after releasing the holding of one of two substrates of the bonding state inspection apparatus according to Embodiment 2. [Figure 14] It is a schematic configuration diagram of the bonding state inspection apparatus according to a modification. [Figure 15A] It is a schematic plan view showing a part of the bonding state inspection apparatus according to a modification. [Figure 15B]It is a schematic cross-sectional view showing a part of a joint state inspection apparatus according to a modification example.

Mode for Carrying Out the Invention

[0010] (Embodiment 1) Hereinafter, a joint state inspection apparatus according to an embodiment of the present invention will be described with reference to the drawings. The joint state inspection apparatus according to the present embodiment continuously detects, from the overlapping direction of two substrates that are joined at least in part, the boundary portion between the joined portion and the non-joined portion that are not joined to each other in the two substrates that change over time. Here, "continuously detecting" means, for example, continuously detecting on the time axis.

[0011] As shown in FIG. 1, the joint state inspection apparatus 1 according to the present embodiment includes a stage 11 that supports substrates W1 and W2, a blade 121 having a substantially rectangular plate shape, a blade holding portion 122 that sandwiches the blade 121 in the thickness direction, a blade driving portion 13 that drives the blade 121 in a direction substantially parallel to the mounting surface 11a of the substrates W1 and W2 on the stage 11 as shown by an arrow AR1, a blade lifting and lowering driving portion 17, imaging portions 21 and 24, and a light source 23. Here, the substrates W1 and W2 are, for example, disk-shaped wafers. The joint state inspection apparatus 1 according to the present embodiment evaluates the joint strength when the substrates W1 and W2 whose joint surfaces have been activated are joined together. Further, the joint state inspection apparatus 1 includes an operation portion 95 for the user to perform an operation to start the inspection or an operation to lift and lower the blade 121 when preparing for the inspection. The stage 11 is formed of a light-transmissive material that transmits at least infrared light, such as transparent glass. Further, the stage 11 has an electrostatic chuck, a vacuum chuck, etc., and is a substrate holding portion that adsorbs and holds the substrates W1 and W2. The rotational driving portion 14 rotates the stage 11 around a rotation axis J1 along the overlapping direction of the substrates W1 and W2 held by the stage 11.

[0012] The blade 121 is approximately 0.1 mm thick and is, for example, a Feather FH-10. The blade drive unit 13 includes a slide body 132 that supports the blade holder 122 via an arm 123, and a slide body drive unit 131 that drives the slide body 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 slide body 132 and the arm 123. The slide body drive unit 131 has an encoder that outputs measured value information to the control unit 90, which shows the measured value that reflects the amount of movement of the slide body 132. The blade lifting drive unit 17 is a blade superposition direction drive unit that changes the position of the edge of the blade 121 in the superposition direction of the substrates W1 and W2 by driving the blade holder 122 in the superposition direction of the substrates W1 and W2, i.e., in the Z-axis direction, as shown by arrow AR2. The blade lifting drive unit 17 raises and lowers the blade 121 in response to the operation performed by the user on the aforementioned control unit to raise or lower the blade 121.

[0013] The imaging unit 21 is, for example, an IR camera, and is positioned to capture images from one side of the superposition direction of substrates W1 and W2, i.e., from vertically above, including the peripheral portion of the substrates W1 and W2 into which the blade 121 is inserted, as shown in Figure 2. The imaging unit 24 is, for example, a visible light camera, and captures the -Y direction edge of the blade 121 from a direction perpendicular to the superposition direction of substrates W1 and W2, i.e., the +X direction. Here, the user can adjust the position of the blade 121 by raising and lowering it using the operation unit 95 while viewing the image captured by the imaging unit 24. The light source 23 is, for example, a light source that emits infrared light and visible light, and emits light toward the stage 11 via a reflector 241 positioned vertically below the stage 11. Also, a light diffuser 242 is positioned vertically below the stage 11 to diffuse the light irradiated from the reflector 241 toward the entire stage 11. In this configuration, if the light source 23 is positioned, for example, directly opposite the center of the light diffuser plate 242, vertically below it, and the light emitted from the light source 23 is directly incident on the light diffuser plate 242, the central part of the light diffuser plate 242 facing the light source 23 in the vertical direction will be relatively bright, while its outer periphery will be relatively dark, resulting in a difference in luminous intensity within the light diffuser plate 242. In contrast, in this embodiment, the light emitted from the light source 23 is reflected once by the reflector plate 241 before being incident on the light diffuser plate 242, thereby achieving uniform luminous intensity throughout the entire light diffuser plate 242.

[0014] As shown in Figure 3A, the blade holding portion 122 is provided with a flat, box-shaped chamber 161, which is open on the side opposite to the side fixed to the blade holding portion 122. The chamber 161 is made of a translucent material such as transparent glass and is positioned to cover at least the area including the edge of the blade 121 and a portion of the two substrates W1 and W2 when the blade 121 is inserted between the two substrates W1 and W2. More specifically, the chamber 161 is positioned to cover the entire blade 121 and the peeled portion Po1 on the substrates W1 and W2 when the blade 121 is inserted between the substrates W1 and W2. Also, inside the chamber 161, a gas supply unit 162 for generating airflow inside the chamber 161 and a humidity sensor 163 for detecting the humidity inside the chamber 161 are provided, which are located at the end of the chamber 161 opposite to the side fixed to the blade holding portion 122. The gas supply unit 162 is, for example, a blower. As shown by arrow AR2 in Figure 3B, the gas discharged from the gas supply unit 162 into the chamber 161 is supplied throughout the entire chamber 161. This maintains the humidity inside the chamber 161 at a preset target humidity and target temperature.

[0015] Returning to Figure 1, the control unit 90 is comprised of a programmable logic controller and a personal computer, and has a processor and a memory for storing programs. In the control unit 90, the processor executes the programs stored in the memory, and as shown in Figure 4, it functions as a blade control unit 911, a blade lifting 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 relationship information generation unit 917, and a gas supply control unit 918. The memory also includes an image storage unit 931 that stores image information showing images captured by the imaging unit 21 in chronological order, 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 relationship information storage unit 936. The image storage unit 931 stores image information representing the captured image taken by the imaging unit 21 while the stage 11 holding the substrates W1 and W2 is rotated by a specified rotation angle from a preset reference position and the blade 121 is inserted between the substrates W1 and W2, in association with rotation angle information indicating the rotation angle.

[0016] The bonding strength storage unit 932 stores bonding strength information, which indicates the calculated bonding strength between the bonded substrates W1 and W2, sequentially in chronological order from the time the blade 121 starts to be inserted.

[0017] The insertion amount storage unit 933 stores insertion amount information, which indicates the amount of insertion of the blade 121 into the substrates W1 and W2 that are joined together, in chronological order from the time the blade 121 starts to be inserted into the substrates W1 and W2. The pressing force storage unit 934 stores pressing force information, which indicates the pressing force when inserting the blade 121 between the substrates W1 and W2 that are joined together, in chronological order from the time the blade 121 starts to be inserted. The elapsed time storage unit 935 stores elapsed time information, which indicates the elapsed time from the time the blade 121 starts to be inserted into the substrates W1 and W2, in chronological order. The correspondence relationship information storage unit 936 stores correspondence relationship information, which indicates at least two correspondence relationships selected from the joining strength of the two substrates W1 and W2, the insertion amount of the blade 121, the pressing force when inserting the blade 121 between the substrates W1 and W2, and the elapsed time from the time the blade 121 starts to be inserted between the substrates W1 and W2.

[0018] The blade control unit 911 controls the operation of the blade drive unit 13 by generating control signals and outputting them to the blade drive unit 13. When a user initiates an inspection operation using the operation unit 95, the blade control unit 911 generates a control signal to drive the blade 121 so that its edge is inserted between the two substrates W1 and W2, and outputs it to the blade drive unit 13. The blade lifting control unit 920 controls the operation of the blade lifting drive unit 17 by generating control signals and outputting them to the blade lifting drive unit 17. When a user initiates an operation to lift or lower the blade 121 using the operation unit 95, the blade lifting control unit 920 generates a control signal to lift or lower the blade 121, the blade holding unit 122, and the blade drive unit 13 together, and outputs it to the blade lifting drive 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, as detected by the humidity sensor 163, reaches a preset target humidity. As a result, at least the area where the aforementioned boundary portion is located in the location where the two substrates W1 and W2 are placed 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 identification unit 919 identifies the boundary between the joined and unjoined portions of the two substrates W1 and W2 by analyzing the captured image taken by the imaging unit 21 with the blade 121 inserted between them. Here, the boundary identification unit 919 detects the position of the boundary using a well-known edge detection technique. As a well-known edge detection technique, edge detection techniques using Sobel filters, Laplacian filters, Canny filters, etc., can be employed. The boundary identification unit 919 notifies the joint strength calculation unit 913 of the information indicating the identified boundary.

[0022] The bonding strength calculation unit 913 uses the captured image captured by the imaging unit 21 to calculate the non-bonding distance from the portion of the two substrates W1 and W2 that is in contact with the blade 121 to the boundary portion of the two substrates W1 and W2 indicated by the information notified by the boundary portion identification unit 919, and calculates the bonding strength of the two substrates W1 and W2 based on the calculated non-bonding distance. Here, the bonding strength calculation unit 913 calculates the non-bonding distance from the tip of the blade 121 to the boundary portion in the image indicated by the image information. However, as shown in Figure 5, the tip of the blade 121 and the portion of the blade 121 that is in contact with the substrates W1 and W2 are separated. Therefore, the bonding strength calculation unit 913 uses a distance L that is the sum of the distance L11 from the tip of the blade 121 to the boundary portion and the distance L11 from the tip of the blade 121 to the contact portion, which is set in advance. Then, the bonding strength calculation unit 913 calculates the bonding strength based on the thicknesses t1 and t2 of substrates W1 and W2, the thickness 2y of blade 121, and the non-bonding distance L from the tip of blade 121 to the boundary, when the blade 121 is inserted between substrates W1 and W2 as shown by arrow AR11 in Figure 5. Here, the bonding strength calculation unit 913 calculates the bonding strength using the following relational equation (1).

[0023]

number

[0024] Here, t1 and t2 are the thicknesses of substrates W1 and W2, respectively; E1 and E2 are the Young's moduli of substrates W1 and W2, respectively; L is the non-joint 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 the calculated bonding strength information in the bonding strength storage unit 932 in a time series. The bonding strength calculation unit 913 also uses each of the captured images indicated by the image information stored in the image storage unit 931 to calculate the non-joint distance corresponding to each rotation angle of the stage 11, and calculates the bonding strength of the two substrates W1 and W2 based on the calculated non-joint distance.

[0025] Returning to Figure 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 encoding of the blade drive unit 13, and stores the insertion amount information indicating the measured insertion amount in the insertion amount storage unit 933 in chronological order. Here, the insertion amount corresponds to the amount of movement when the blade drive unit 13 moves the blade holding unit 122 in the direction toward the substrates W1 and W2.

[0026] The lateral pressure measuring unit 915 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 pressing force measuring 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 showing the measured pressing force in the pressing force storage unit 934 in chronological order. The elapsed time measuring unit 916 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. The elapsed time measuring unit 916 measures the elapsed time from the time it detected that the blade 121 had come into contact with the substrates W1 and W2, and stores the elapsed time information showing the measured elapsed time in chronological order in the elapsed time storage unit 935.

[0027] The correspondence relationship information generation unit 917 generates correspondence relationship information that shows at least two correspondence relationships selected from the following: the bonding strength of the two substrates W1 and W2, the insertion amount of the blade 121, the pressing force 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 relationship information generation unit 917 generates correspondence relationship information using the bonding strength information stored in the bonding strength storage unit 932, and one of the insertion amount information stored in the insertion amount storage unit 933, the pressing force information stored in the pressing force storage unit 934, and the elapsed time information stored in the elapsed time storage unit 935. Then, the correspondence relationship information generation unit 917 stores the generated correspondence relationship information in the correspondence relationship information storage unit 936.

[0028] Next, a bonding state inspection method using the bonding state inspection apparatus 1 according to this embodiment will be described with reference to Figure 6. Here, it is assumed that the substrates W1 and W2 are already supported on the stage 11. First, the blade drive unit 13 starts moving the blade 121 in the direction of insertion of the blade 121 between the substrates W1 and W2 (step S101). Next, 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 encoding of the blade drive unit 13, and stores the insertion amount information indicating the measured insertion amount in the insertion amount storage unit 933 in chronological order (step S102). Subsequently, the pressing force measuring 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 storage unit 934 in chronological order (step S103). Subsequently, the elapsed time measurement unit 916 measures the elapsed time from the start of insertion of the blade 121 between substrates W1 and W2, and stores the measured elapsed time information in the elapsed time storage unit 935 in chronological order (step S104).

[0029] Next, the bonding strength calculation unit 913 uses the captured images taken by the imaging unit 21 to calculate the distance from the portion of the two substrates W1 and W2 that is in contact with the blade 121 to the boundary portion of the two substrates W1 and W2, and calculates the bonding strength of the two substrates W1 and W2 based on the calculated distance. The bonding strength calculation unit 913 then stores the bonding strength information indicating the calculated bonding strength in the bonding strength storage unit 932 in chronological order (step S105). Subsequently, the blade control unit 911 determines whether or not a preset inspection completion condition has been met (step S106). This inspection completion condition is set, for example, when the insertion amount of the blade 121 between the substrates W1 and W2 reaches a preset target insertion amount. If the blade control unit 911 determines that the inspection completion condition has not yet been met (step S106: No), it continues to insert the blade 121 between the substrates W1 and W2, and the process in step S102 is executed again.

[0030] On the other hand, if the blade control unit 911 determines that the inspection completion conditions have not yet been met (step S106: No), it stops inserting the blade 121 (step S107). Subsequently, the correspondence relationship information generation unit 917 generates correspondence relationship information using the bonding strength information stored in the bonding strength storage unit 932, and one of the insertion amount information stored in the insertion amount storage unit 933, the pressing force information stored in the pressing force storage unit 934, and the elapsed time information stored in the elapsed time storage unit 935. Then, the correspondence relationship information generation unit 917 stores the generated correspondence relationship information in the correspondence relationship information storage unit 936 (step S108).

[0031] Correspondence information includes, for example, information showing the correspondence between bonding strength and insertion amount as shown in Figure 7A, information showing the correspondence between bonding strength and pressing force as shown in Figure 7B, or information showing the correspondence between bonding strength and elapsed time from the start of blade 121 insertion as shown in Figure 7C.

[0032] The bonding state inspection method according to this embodiment involves activating the bonding surfaces of substrates W1 and W2, which are wafers, by plasma treatment or irradiation with a particle beam, then making the bonding surfaces hydrophilic by washing them with water, and then bringing the central parts of the bonding surfaces of substrates W1 and W2 into contact and bonding them together. After that, a heat treatment is performed to firmly bond them, and then the bonding strength between substrates W1 and W2 is measured by inserting a blade 121 into the periphery of substrates W1 and W2. The bonding state can then be evaluated in more detail by evaluating the relationship between the insertion amount of the blade 122, the pressing force, and the elapsed time after insertion of the blade 121, humidity, or temperature.

[0033] As described above, the bonding state inspection device 1 according to this embodiment continuously detects the boundary portion between the bonded and unbonded parts of the two substrates W1 and W2, which change over time, from the overlapping direction of the two substrates W1 and W2 that are bonded at least in part. This makes it possible to understand the influence of the aforementioned boundary portion's change over time on the bonding state of the two substrates W1 and W2, and thus allows for a detailed analysis of the bonding state of the two substrates W1 and W2.

[0034] Incidentally, if moisture penetrates the bonding interface between substrates W1 and W2 that are joined together, the molecular bonds in the bonded portion will break down due to the moisture, reducing the strength of the bonded portion. Therefore, if there is variation in the humidity around substrates W1 and W2, the measured values ​​of the bonding strength of the bonded portion will vary, or the bonding strength will decrease. In contrast, the bonding state inspection device 1 according to this embodiment includes a chamber 161 arranged to cover at least the blade insertion portion in which the blade 121 is inserted in the two substrates W1 and W2, and a gas supply unit 162 that supplies humidity-adjusted gas into the chamber 161 to maintain positive pressure inside the chamber 161 relative to the outside of the chamber 161, and maintains the humidity inside the chamber 161 at a preset humidity. As a result, the humidity around substrates W1 and W2 inside the chamber 161 is maintained constant, so that variations in the measured values ​​of the bonding strength of the bonded portion can be suppressed.

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

[0036] (Embodiment 2) The bonding condition inspection device according to this embodiment differs from Embodiment 1 in that it comprises a substrate holding unit that holds two substrates spaced apart from each other, a pressing mechanism that presses the central part of one of the two substrates toward the other, thereby bringing the central part of one substrate 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 virtual straight line that extends radially from the central parts of the two substrates.

[0037] As shown in Figure 8, the bonding state inspection apparatus 2001 according to this embodiment includes a stage 2011 that supports a substrate W1, a plurality of substrate holding parts 171 that each hold multiple locations on the periphery of a substrate W2, a holding part drive unit 172 that raises and lowers the substrate holding parts 171 and moves them horizontally, a pressing mechanism 15, an imaging unit 22, and a light source 23. In Figure 8, components similar to those in Embodiment 1 are denoted by the same reference numerals as in Figure 1. Here, substrates W1 and W2 are, for example, disc-shaped wafers. The bonding state inspection apparatus 2001 according to this embodiment evaluates the activation state of each substrate W1 and W2 whose bonding surface has been activated based on the wetting spread rate as bonding progresses after the central parts of substrates W1 and W2 are brought into contact. The bonding state inspection apparatus 2001 includes an operation unit 95 for the user to start the inspection. The stage 2011 is formed from a translucent material that transmits at least infrared light, such as transparent glass, similar to the stage 11 described in Embodiment 1. Furthermore, the stage 2011 has an electrostatic chuck, a vacuum chuck, etc., and holds the substrate W1 by suction. The substrate holding part 171 has an inclined surface 1711a that abuts the vertically downward side of the periphery of one of the two substrates W1 and W2, which is positioned vertically above the other substrate, and supports the periphery of one of the substrates W2, and an arm 1712 to which the substrate holding part 1711 is fixed at its tip. The holding part drive unit 172 supports the end of the arm 1712 of the substrate holding part 1711 that is opposite to the substrate holding part 1711, and raises and lowers the arm 1712.

[0038] As shown in Figure 9A, the pressing mechanism 15 includes a pressing portion 151 that contacts the substrate W2, an overlapping direction drive portion 152 that moves the pressing portion 151 in the overlapping direction of the substrates W1 and W2, and a horizontal drive portion 153 that moves the pressing portion 151 and the overlapping direction drive portion 152 together in a direction perpendicular to the overlapping direction of the substrates W1 and W2, as shown by arrow AR2, that is, in a direction substantially parallel to the mounting surface 2011a of the substrate W1 on the stage 2011. The holding portion drive portion 172 is installed at three locations on the outer periphery of the stage 2011, as shown in Figure 9B. The substrate holding portion 171 extends from each of the three holding portion drive portions 172 toward the center of the stage 2011, and supports the periphery of the substrate W2 at its tip. Here, the holding unit drive unit 172 presses the central part of the substrate W2 toward the substrate W1 using the pressing mechanism 171, thereby bringing the central part of the substrate W2 into contact with the substrate W1. Then, as the boundary between the joined and separated parts of the two substrates W1 and W2 moves toward the periphery of the substrates W1 and W2, the substrate holding unit 171 is detached from the substrate W2.

[0039] Returning to Figure 8, the imaging unit 22, like the imaging unit 21 described in Embodiment 1, is, for example, an IR camera, and is positioned to capture the entirety of the substrate W1 held on the stage 11 and the substrate W2 supported by a plurality of substrate holding units 171 from one side in the direction of overlap 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 when the processor executes a program stored in memory, it functions as a pressing 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 relationship information generation unit 2923, as shown in Figure 10. In Figure 10, components similar to those in Embodiment 1 are denoted by the same reference numerals as in Figure 4. The memory also includes an image storage unit 2931 that stores image information showing 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 relationship information storage unit 2936. The boundary position storage unit 2937 stores position information indicating the positions PBL1_11, PBL1_12, PBL1_21, and PBL1_22 on two virtual lines VL1 and VL2 that radiate from the central parts of the two substrates W1 and W2, at the boundary between the bonded portion and the delamination portion of the two substrates W1 and W2, as shown in Figure 11, for example. In this embodiment, an example in which there are two virtual lines VL1 and VL2 is described, but the number of virtual lines is not particularly limited, and the boundary position storage unit 2937 may store position information indicating positions on three or more virtual lines that intersect at the same intersection point, for example.

[0041] Returning to Figure 10, the movement speed storage unit 2938 stores movement speed information in chronological order, indicating the movement speed of the boundary portion between the bonded portion and the delamination portion on the two substrates W1 and W2 as it moves toward the periphery of substrates W1 and W2. The stop position storage unit 2939 stores stop position information indicating the stop position when the movement of the aforementioned boundary portion on the two substrates W1 and W2 stops. The correspondence relationship information storage unit 2936 stores correspondence relationship information indicating at least two correspondences selected from the time elapsed since the substrate holding unit 171 released support of the periphery of substrate W2 after the central portions of substrates W1 and W2 came into contact, the movement speed of the aforementioned boundary portion on substrates W1 and W2, the stop position of the aforementioned boundary portion, and the virtual line identification information that identifies the aforementioned virtual line.

[0042] The pressing control unit 2919 controls the operation of the superposition direction drive unit 152 and the horizontal drive unit 153 of the pressing mechanism 15 by generating a control signal and outputting it to the pressing mechanism 15. The pressing control unit 2919 also controls the superposition direction drive unit 152 and the horizontal drive unit 153 so that after the center of the substrate W2 is brought into contact with the substrate W1, the pressing unit 151 is detached from the substrate W2 and then moved in a direction perpendicular to the superposition direction of substrates W1 and W2, retracting it outside the projection area of ​​substrates W1 and W2 in the superposition direction. When a user performs an operation to start an inspection on the operation unit 95, the pressing control unit 2919 generates a control signal to the pressing mechanism 15 in response to this, first pressing the center of the substrate W2 with the pressing unit 151 to bring the center of the substrate W2 into contact with the substrate W1. Next, the pressing control unit 2919 generates a control signal to the pressing mechanism 15 to detach the pressing unit 151 from the substrate W2, move it in a direction perpendicular to the overlapping direction of substrates W1 and W2, and move it to the outside of the projection area in the overlapping direction of substrates W1 and W2.

[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 the image storage unit 2931 in chronological order. Here, the image acquisition unit 2912 stores in the image storage unit 2931 image information representing each captured image taken by the imaging unit 22 at a preset imaging period after the central part of the substrate W2 comes into contact with the substrate W1.

[0044] The boundary position detection unit 2920 uses the captured images taken by the imaging unit 22 to detect the boundary between the bonded and debonded portions of the two substrates W1 and W2. Here, the boundary position detection unit 2920 uses a well-known edge detection technique to detect the position of the boundary portion on, for example, the virtual lines VL1 and VL2 shown in Figure 11. As a well-known edge detection technique, edge detection techniques using Sobel filters, Laplacian filters, Canny filters, etc. can be employed. The boundary position detection unit 2920 then stores the position information indicating the detected boundary portion in the boundary position storage unit 2937, associating it with virtual line identification information that identifies the virtual lines VL1 and VL2. Furthermore, the boundary position detection unit 2920 detects the position of the aforementioned boundary portion for each captured image taken by the imaging unit 22 at a preset imaging period after the central part of substrate W2 has come into contact with substrate W1, as indicated by the image information stored in the image storage unit 2931. Furthermore, the boundary position detection unit 2920 determines when to start detecting the position of the boundary portion based on the point in time when the pressing portion 151 of the pressing mechanism 15 retracts outside the projection area of ​​substrates W1 and W2 in the direction of overlap, after the central part of substrate W2 has been brought into contact with substrate W1. Specifically, the boundary position detection unit 2920 selects image information from the image storage unit 2931 that shows an image captured by the imaging unit 22 after the point in time when the pressing portion 151 of the pressing mechanism 15 retracts outside the projection area of ​​substrates W1 and W2 in the direction of overlap, and detects the position of the boundary portion only for the image captured by the selected image information.

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

[0046] The correspondence relationship information generation unit 2923 generates correspondence relationship information that indicates at least two correspondence relationships selected from the following: the elapsed time from the point when the support of the peripheral portion of substrate W2 by the substrate holding unit 171 is released after the central portions of substrates W1 and W2 have come into contact with each other; the movement speed of the aforementioned boundary portion of substrates W1 and W2; the stopping position of the said boundary portion; and virtual line identification information that identifies the aforementioned virtual line. Specifically, the correspondence relationship information generation unit 2923 generates correspondence relationship information using the position information stored in the boundary position storage unit 2937, the movement speed information stored in the movement speed storage unit 2938, the stopping position information stored in the stopping position storage unit 2939, the elapsed time information stored in the elapsed time storage unit 935, and virtual line information that identifies virtual lines VL1 and VL2. Then, the correspondence relationship information generation unit 2923 stores the generated correspondence relationship information in the correspondence relationship information storage unit 2936.

[0047] Next, a bonding condition inspection method using the bonding condition inspection apparatus 2001 according to this embodiment will be described with reference to Figures 12 and 13. Here, it is assumed that the substrate W1 is already supported on the stage 2011, and the substrate W2 is supported by three substrate holding parts 171 in a state separated from the substrate W1. First, as shown in Figure 12, the pressing mechanism 15 presses the central part of the substrate W2 toward the substrate W1 with the pressing part 151, thereby bringing the central parts of the substrates W1 and W2 into contact (step S201). Here, the pressing mechanism 15 first brings the pressing part 151 into contact with the central part of the substrate W2, as shown in Figure 13A, and then, as shown by arrow AR31 in Figure 13B, lowers the pressing part 151 toward the substrate W1, thereby bringing the central part of the substrate W2 into contact with the central part of the substrate W1.

[0048] Returning to Figure 12, the next step is for the holding unit drive unit 172 to release support for the substrate W2 by moving the substrate holding unit 171 away from the substrate W2 (step S202). Here, the holding unit drive unit 172 releases support for the substrate W2 by moving the substrate holding unit 171 away from the periphery of the substrate W2, as shown by arrow AR32 in Figure 13C. As a result, the substrate W2 makes contact with the substrate W1 sequentially from the central part that was in contact with the substrate W1 towards the periphery of the substrate W2, as shown by arrow AR33.

[0049] Returning to Figure 12, the boundary position detection unit 2920 then uses the captured image captured by the imaging unit 22 to detect the boundary between the bonded portion and the delaminate portion of the two substrates W1 and W2. The boundary position detection unit 2920 then stores the position information indicating the location of the detected boundary portion in the boundary position storage unit 2937, associating it with virtual line identification information that identifies virtual lines VL1 and VL2 (step S203). Subsequently, the movement speed measurement unit 2921 measures the movement speed of the boundary portion as it moves toward the periphery of substrates W1 and W2, based on the position information stored in the boundary position storage unit 2937. The movement speed measurement unit 2921 then stores the movement speed information indicating the measured movement speed in the movement speed storage unit 2938 in chronological order (step S204). Next, the elapsed time measurement unit 916 measures the elapsed time after the center of substrate W2 is brought into contact with the center of substrate W1, and stores the measured elapsed time information in the elapsed time storage unit 935 in chronological order (step S205).

[0050] Next, the stop position detection unit 2922 determines whether the boundary portion has stopped because the movement speed measured by the movement speed measurement unit 2921 is 0 (step S206). 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 boundary portion has not yet stopped (step S206: No), the process in 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 is 0 and the boundary portion has stopped (step S206: Yes), it identifies the position indicated by the position information at the time it was determined that the boundary portion had stopped, which is stored in the boundary position storage unit 2937, as the stop position, and stores the stop position information indicating the identified stop position in the stop position storage unit 2939 (step S207).

[0051] Subsequently, the correspondence relationship information generation unit 2923 generates correspondence relationship information using the position information stored in the boundary position storage unit 2937 and one of the following: 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 virtual line information that identifies virtual lines VL1 and VL2. Then, the correspondence relationship information generation unit 2923 stores the generated correspondence relationship information in the correspondence relationship information storage unit 2936 (step S208).

[0052] The bonding state inspection method according to this embodiment involves activating the bonding surfaces of substrates W1 and W2, which are wafers, by plasma treatment or irradiation with a particle beam, then hydrophilizing the bonding surfaces by washing them with water, and then bringing the central parts of the bonding surfaces of substrates W1 and W2 into contact with each other before bonding them together. The activation state of the bonding surfaces is evaluated from the state of wetting spread of substrates W1 and W2, the occurrence of voids, and the stopping position of the wetting spread at this time. Furthermore, the activation state of the bonding surfaces of substrates W1 and W2 can be evaluated in more detail by evaluating the relationship between the elapsed time after the central parts of substrates W1 and W2 are brought into contact, the movement speed of the boundary portion, the stopping position of the boundary portion, and the position, number, and size of voids that have occurred between the two substrates W1 and W2. In addition, the cleaning state of the bonding surfaces of substrates W1 and W2 can be evaluated from the occurrence of voids.

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

[0054] Although various embodiments of the present invention have been described above, the present invention is not limited to the configurations of the embodiments described above. 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 Figure 14, the bonding state inspection device 3001 may include a stage 2011, a plurality of substrate holding units 171, a holding unit drive unit 172, a pressing mechanism 15, and a control unit 3090, along with a stage 11, a rotary drive unit 14, a blade 121, a blade holding unit 122, a blade drive unit 13, an imaging unit 21, and a light source 23. In Figure 14, components similar to those in each embodiment are denoted by the same reference numerals as in Figures 1 and 8. Here, the stage 11 and the rotary drive unit 14 can be positioned as shown by arrow AR31, when performing the bonding state inspection method described in Embodiment 1, or retracted to a position where they do not interfere with the pressing unit 151 when the pressing unit 151 is brought into contact with the center of the substrate W2 held by the plurality of substrate holding units 171. Furthermore, the imaging unit 21 can be positioned either as described by arrow AR32, when performing the bonding state inspection method described in Embodiment 1, or as described in Embodiment 2. In addition, the control unit 3090 has the functions of both the control units 90 and 2090 described in Embodiments 1 and 2, respectively.

[0055] With this configuration, two types of inspections can be performed with a single joint condition inspection device 3009, thus saving space compared to installing two separate joint condition inspection devices for each type of inspection.

[0056] In each embodiment, the object to be inspected is not limited to substrates W1 and W2, but may also include a wafer, chip, or other bonded object.

[0057] In Embodiment 1, the gas supply unit 162 may supply a mixture of multiple types of gases with different water content into the chamber 161. In this case, the gas supply unit 162 can supply a gas with a predetermined water content by adjusting the mixing ratio of the multiple types of gases, and the gas supply control unit 918 may control the mixing ratio of the multiple types of gases.

[0058] In Embodiment 1, the chamber 161 may be equipped with a temperature detection unit for detecting the temperature inside the chamber 161, and the gas supply unit 162 may be equipped with a temperature adjustment mechanism for adjusting the temperature of the gas supplied into the chamber 161. Furthermore, the gas supply control unit 918 may control the gas supply unit 162 so that the temperature detected by the temperature detection unit becomes a preset target temperature.

[0059] In Embodiment 1, the system may include an imaging unit that images the edge of the blade 121 from a direction perpendicular to the superposition direction of the substrates W1 and W2, and a blade holding unit superposition direction drive unit that moves the blade holding unit 122 and the blade driving unit 123 together up and down in the superposition direction of the substrates W1 and W2, thereby changing the position of the edge of the blade 121 in the superposition direction of the substrates W1 and W2.

[0060] In Embodiment 1, the device may include a substrate holding section that holds two elongated substrates joined together. In this case, the bonding condition inspection device may move the imaging section 21 in accordance with the movement of the blade, or move the substrate holding section, in order to maintain the relative positional relationship between the blade and the imaging section 21. As shown in Figures 15A and 15B, the blade holding section 4122 in this modified example holds the blade 4121 on the outside of both ends in the short direction of the substrates W41 and W42. Note that in Figures 15A and 15B, components similar to those in Embodiment 1 are denoted by the same reference numerals as in Figures 3A and 3B. Then, as shown in Figure 15B, when the blade 4121 is inserted between the substrates W41 as indicated by arrow AR411, if the length L411 from the edge of the blade 4121 to the edge of the substrates W41 and W42 on the longitudinal direction where the blade 4121 is inserted is longer than the length L412 from the edge of the blade 4121 to the position held by the blade holding portion 122 on the blade 4121, then a bonded portion Po0 exists 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-bonded portion Po1 peeled off by the blade 4121 is located on the opposite side of the substrates W41 and W42 from the bonded portion Po0 side of the blade 4121. Then, as the blade 4122 is moved further towards the joint portion Po0 side of the substrates W41 and W42, the non-jointed portion Po1 peeled off by the blade 4121 flows to the opposite side of the blade 4121 from the joint portion Po0 side on the substrates W41 and W42. Here, the bonding condition inspection device includes a substrate holding support (not shown) that supports the substrate holding portion according to the shape of the substrates W41 and W42.

[0061] This configuration allows for inspection of the bonding state of substrates W41 and W42, which have a so-called strip-like shape.

[0062] In Embodiment 1, an example was described in which the blade lifting drive unit 17 raises and lowers the blade 121, blade holder 122, and blade drive unit 13 together based on a control signal input from the control unit 90. However, the invention is not limited to this, and the blade lifting drive unit 17 may have a gear mechanism connected to a handle that can be manually operated by the user, and when the user rotates the handle, the blade 121, blade holder 122, and blade drive unit 13 are raised and lowered together. In Embodiment 1, the rotation drive unit 14 may also have a gear mechanism connected to a handle that can be manually operated by the user, and when the user rotates the handle, the stage 11 is rotated around a rotation axis J1 that is in the direction of superposition of the substrates W1 and W2 held on the stage 11.

[0063] In Embodiment 1, the stage 11 may further include a substrate holding support portion that interchangeably supports either a stage that is circular in plan view and capable of holding a disc-shaped wafer, or a long stage that can hold a long rectangular plate-shaped substrate.

[0064] In Embodiment 1, the boundary portion identification unit 919 may identify each boundary portion between the bonded portion and the non-bonded portion at multiple locations on the substrates W1 and W2 by analyzing the captured images taken by the imaging unit 21 with the blade 121 inserted at each of the multiple locations on the substrates W1 and W2. The bond strength calculation unit 913 may then calculate the non-bonded portion distance between the edge of the blade 121 on the substrates W1 and W2 and the boundary portion for each of the multiple locations using the captured images, and calculate the bond strength of the substrates W1 and W2 based on the representative value of the calculated non-bonded portion distance at each of the multiple locations. Here, the representative value can be an average value, median value, maximum value, minimum value, etc.

[0065] In Embodiment 2, the bonding state inspection apparatus 2001 may include a void identification unit that identifies the location, number, and size of voids that have occurred between substrates W1 and W2. Here, the void identification unit identifies the location, number, and size of the voids that have occurred based on image information, for example, an image storage unit 2931, which stores images of the substrates W1 and W2 in a bonded state. In this case, the correspondence relationship generation unit 2923 may generate correspondence relationship information that indicates at least two correspondence relationships selected from the following: the elapsed time from the point when the support of the peripheral portion of substrate W2 by the substrate holding unit 171 is released after the central portions of substrates W1 and W2 have come into contact; the moving speed of the aforementioned boundary portion of substrates W1 and W2; the stopping position of the boundary portion; virtual line identification information that identifies the aforementioned virtual line; and the location, number, and size of the voids that have occurred between the identified substrates W1 and W2.

[0066] In Embodiment 2, the boundary position detection unit 2920 may detect the position of the boundary portion between the bonded portion and the non-bonded portion of the substrates W1 and W2 on a plurality of virtual lines extending radially from the center of the substrates W1 and W2. The moving speed measurement unit 2921 may then detect the position on the plurality of virtual lines in synchronization with the detection of the boundary portion, thereby detecting the moving speed of the boundary portion on each virtual line and calculating a representative value of the moving speed corresponding to each of the plurality of virtual lines. Here, the representative value can be the average value, median value, maximum value, minimum value, etc. of the moving speed corresponding to each of the plurality of virtual lines.

[0067] Furthermore, in Embodiment 2, the boundary position detection unit 2920 may detect the position of the boundary portion between the bonded portion and the non-bonded portion of the substrates W1 and W2 on a plurality of virtual lines extending radially from the center of the substrates W1 and W2, and the stop position detection unit 2922 may calculate a representative value of the position of the stopped boundary portion on each of the plurality of virtual lines. Here, as the representative value, the average value, median value, maximum value, minimum value, etc. of the stop position corresponding to each of the plurality of virtual lines can be adopted.

[0068] This invention allows for various embodiments and modifications without departing from the broad spirit and scope of the invention. Furthermore, the embodiments described above are for illustrative purposes only and do not limit the scope of the invention. In other words, the scope of the invention is indicated not by the embodiments, but by the claims. Various modifications made within the scope of the claims and the equivalent scope of the meaning of the invention are considered to be within the scope of this invention.

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

[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, memory, computing elements, and MEMS (Micro Electro Mechanical Systems). [Explanation of Symbols]

[0071] 1,2001,3001: Bonding state device, 11,2011: Stage, 11a,2011a: Mounting surface, 13: Blade drive unit, 14: Pressure sensor, 15: Pressing mechanism, 21,22: Imaging unit, 23: Light source, 90,2090: Control unit, 121: Blade, 122: Blade holder, 123: Arm, 131: Slide body drive unit, 132: Slide body, 151: Pressing unit, 152: Lifting drive unit, 153: Horizontal drive unit, 161: Chamber, 162: Gas supply unit, 163: Humidity sensor, 171: Support piece, 172: Support piece drive unit, 241: Reflector, 242: Light diffuser, 911: Blade control unit, 912,2912: Image 913: Acquisition unit, 914: Bonding strength calculation 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 part 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, in synchronization with continuously detecting the boundary portion, measures the pressing force applied to the blade when inserting the blade between the two substrates, 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 relationship information generation unit that generates correspondence relationship information indicating at least two correspondence relationships 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 apparatus 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 change 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 change 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 superposition of the two substrates, thereby changing the position of the edge of the blade in the direction of 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 extending radially 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 extending radially 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 joint.

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 joint.

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 joint.

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 joint.

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