Joining device and joining method

Abstract

The bonding device (41) involved in the embodiment comprises a holding portion (111, 211), a deformation portion (114, 213) and a control portion (70a). The holding portion (111, 211) holds substrates (W1, W2) to be bonded. The deformation portion (114, 213) causes the central portion of the substrate (W1, W2) held by the holding portion (111, 211) to protrude relative to the outer peripheral portion of the substrate (W1, W2). The control portion (70a) adjusts the protrusion amount of the substrate (W1, W2) caused by the deformation portion (114, 213) for each substrate (W1, W2) based on at least one of the thickness of the substrate (W1, W2), the temperature of the substrate (W1, W2) and the warping of the substrate (W1, W2) when not held by the holding portion (111, 211).

Description

Technical Field

[0001] The present disclosure relates to a joining device and a joining method. Background Art

[0002] Patent Document 1 discloses a bonding apparatus for bonding substrates to each other.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-5219 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The present disclosure provides a technology for improving the bonding accuracy of substrates.

[0008] Solutions for solving problems

[0009] A bonding device according to one embodiment of the present disclosure includes a holding portion, a deformation portion, and a control portion. The holding portion holds substrates to be bonded. The deformation portion causes the central portion of the substrate held by the holding portion to protrude relative to the outer peripheral portion of the substrate. The control portion adjusts the protrusion amount of the substrate by the deformation portion for each substrate based on at least one of the thickness of the substrate, the temperature of the substrate, and the warpage of the substrate when not held by the holding portion.

[0010] Effects of the Invention

[0011] According to the present disclosure, it is possible to improve the bonding accuracy of substrates. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 1 is a schematic diagram showing the structure of a joining system according to an embodiment.

[0013] Figure 2 This is a schematic diagram showing the structure of the joining system involved in the embodiment (part 2).

[0014] Figure 3 It is a schematic diagram of the structure of the transmission unit involved in the embodiment.

[0015] Figure 4 It is a schematic diagram showing a partial structure of a joining device according to an embodiment.

[0016] Figure 5 It is a schematic diagram showing the structure of the first suction cup part and the second suction cup part involved in the embodiment.

[0017] Figure 6It is a schematic diagram showing a state where the second substrate according to the embodiment is bent.

[0018] Figure 7 This is a flowchart illustrating the joining process involved in the embodiment.

[0019] Figure 8 It is a diagram showing a state in which a first substrate and a second substrate are bent in a bonding process according to the embodiment. DETAILED DESCRIPTION

[0020] Hereinafter, embodiments of the bonding apparatus and bonding method disclosed in the present application will be described in detail with reference to the accompanying drawings. In addition, the disclosed bonding apparatus and bonding method are not limited to the embodiments shown below.

[0021] In the drawings referred to below, in order to make the description easier to understand, an orthogonal coordinate system is sometimes shown in which the X-axis direction, the Y-axis direction, and the Z-axis direction are orthogonal to each other and the positive direction of the Z-axis is set as the vertical upward direction. The X-axis direction and the Y-axis direction are horizontal directions. In the following, the positive direction of the Z-axis is sometimes set as the upward direction and the negative direction of the Z-axis is set as the downward direction for description.

[0022] <Structure of the joint system>

[0023] Reference Figure 1 and Figure 2 A joining system 1 according to the embodiment will be described. Figure 1 1 is a schematic diagram showing a configuration of a joining system 1 according to an embodiment. Figure 2 It is a schematic diagram (part 2) showing the structure of the joining system 1 according to the embodiment.

[0024] The bonding system 1 forms a superimposed substrate T by bonding the first substrate W1 and the second substrate W2 .

[0025] The first substrate W1 and the second substrate W2 are, for example, substrates on which a plurality of electronic circuits are formed on semiconductor substrates such as silicon wafers and compound semiconductor wafers. The first substrate W1 and the second substrate W2 are circular and have substantially the same diameter. In addition, one of the first substrate W1 and the second substrate W2 may be, for example, a substrate on which no electronic circuits are formed.

[0026] Hereinafter, the plate surface of the first substrate W1 on the side bonded to the second substrate W2 is referred to as a "bonding surface", and the plate surface on the side opposite to the bonding surface is referred to as a "non-bonding surface". In addition, the plate surface of the second substrate W2 on the side bonded to the first substrate W1 is referred to as a "bonding surface", and the plate surface on the side opposite to the bonding surface is referred to as a "non-bonding surface".

[0027] The bonding system 1 includes a loading / unloading station 2 and a processing station 3. The loading / unloading station 2 is disposed on the negative side of the processing station 3 in the X-axis direction and is connected to the processing station 3 in an integrated manner.

[0028] The loading and unloading station 2 includes a loading platform 10 and a conveying area 20. The loading platform 10 includes a plurality of loading plates 11. Boxes C1 to C4 for accommodating a plurality of (e.g., 25) substrates in a horizontal state are placed on each loading plate 11. Box C1 can accommodate a plurality of first substrates W1, box C2 can accommodate a plurality of second substrates W2, and box C3 can accommodate a plurality of overlapping substrates T. Box C4 is, for example, a box for recovering defective substrates. In addition, the number of boxes C1 to C4 placed on the loading plate 11 is not limited to the number shown in the figure.

[0029] The conveying area 20 is arranged adjacent to the mounting table 10 on the positive side of the mounting table 10 in the X-axis direction. A conveying path 21 extending in the Y-axis direction and a conveying device 22 that can move along the conveying path 21 are provided in the conveying area 20. The conveying device 22 can move not only in the Y-axis direction but also in the X-axis direction, and can rotate around the Z-axis. The conveying device 22 conveys the first substrate W1, the second substrate W2, and the overlapped substrate T between the cassettes C1 to C4 mounted on the mounting plate 11 and the third processing block G3 of the processing station 3 described later.

[0030] For example, three processing blocks G1, G2, and G3 are provided in the processing station 3. The first processing block G1 is arranged on the front side of the processing station 3 ( Figure 1 In addition, the second processing block G2 is arranged on the back side of the processing station 3 ( Figure 1 The third processing block G3 is arranged on the side of the processing station 3 close to the loading and unloading station 2 ( Figure 1 negative side of the X-axis).

[0031] The first processing block G1 is provided with a surface modification device 30 for modifying the bonding surface of the first substrate W1 and the second substrate W2. The surface modification device 30 cuts the bonds of SiO2 in the bonding surface of the first substrate W1 and the second substrate W2 to form single-bonded SiO, thereby modifying the bonding surface to make it easy to be hydrophilic later.

[0032] Specifically, in the surface modification device 30, oxygen or nitrogen as a processing gas is excited to plasma in a reduced pressure atmosphere, thereby ionizing. Then, by irradiating the bonding surface of the first substrate W1 and the second substrate W2 with oxygen ions or nitrogen ions, the bonding surface is plasma-treated and modified.

[0033] A surface hydrophilization device 40 and a bonding device 41 are arranged in the second processing block G2. The surface hydrophilization device 40 hydrophilizes the bonding surface of the first substrate W1 and the second substrate W2 by, for example, pure water, and cleans the bonding surface. Specifically, the surface hydrophilization device 40 supplies pure water to the first substrate W1 or the second substrate W2 while rotating the first substrate W1 or the second substrate W2 held on the rotating suction cup. As a result, the pure water supplied to the first substrate W1 or the second substrate W2 diffuses on the bonding surface of the first substrate W1 or the second substrate W2 to hydrophilize the bonding surface. The structure of the bonding device 41 will be described later.

[0034] like Figure 2 As shown, in the third processing block G3, a conveying device 50 for the first substrate W1, a conveying device 50 for the second substrate W2, and a conveying device 51 for the overlapping substrate T are arranged in order from the bottom.

[0035] A conveying area 60 is formed in an area surrounded by the first processing block G1, the second processing block G2, and the third processing block G3. A conveying device 61 is disposed in the conveying area 60. The conveying device 61 has, for example, a conveying arm that is movable in the vertical direction, the horizontal direction, and around the vertical axis. The conveying device 61 moves in the conveying area 60 to convey the first substrate W1, the second substrate W2, and the overlapped substrate T to a specified device in the first processing block G1, the second processing block G2, and the third processing block G3 adjacent to the conveying area 60.

[0036] In addition, the joining system 1 is provided with a control device 70. The control device 70 controls the operation of the joining system 1. The control device 70 is, for example, a computer, and is provided with a control unit 70a and a storage unit 70b. The control unit 70a includes a microcomputer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output port, and various circuits. The CPU of the microcomputer implements the control described later by reading and executing the program stored in the ROM. In addition, the storage unit 70b is implemented by, for example, a semiconductor memory element such as a RAM, a flash memory, or a storage device such as a hard disk or an optical disk.

[0037] In addition, the program can be recorded in a computer-readable recording medium and installed from the recording medium to the storage unit 70b of the control device 70. Examples of the computer-readable recording medium include a hard disk (HD), a floppy disk (FD), a compact disk (CD), a magneto-optical disk (MO), a memory card, and the like.

[0038] <Joining device>

[0039] Next, the bonding device 41 will be described. Figure 1 As shown, the bonding apparatus 41 is divided into a transfer area T1 and a processing area T2.

[0040] The conveying area T1 is provided with a conveying unit 80 for temporarily placing the first substrate W1, the second substrate W2, and the superimposed substrate T. In the bonding device 41, the first substrate W1, the second substrate W2, and the superimposed substrate T are conveyed in the conveying area T1 or between the conveying area T1 and the processing area T2 by a conveying device (not shown). In addition, a position adjustment mechanism (not shown) for adjusting the horizontal orientation of the first substrate W1 and the second substrate W2 and a reversing mechanism (not shown) for reversing the front and back of the first substrate W1 are provided in the conveying area T1.

[0041] <Transmission Department>

[0042] like Figure 3 As shown, the conveying unit 80 includes a placing unit 81 , displacement sensors 82 a and 82 b , and a load sensor 83 . Figure 3 Schematic diagram showing the structure of the conveying unit 80 according to the embodiment. In addition, the conveying unit 80 may be provided in multiple layers in the vertical direction, for example.

[0043] The loading section 81 supports the first substrate W1, the second substrate W2, and the overlapping substrate T from below these substrates, for example, by using a plurality of supporting pins 81a. The plurality of supporting pins 81a abut against the non-joining surfaces of the first substrate W1 and the like to support each substrate. The plurality of supporting pins 81a are raised and lowered by an actuator (not shown) disposed on the loading section 81. In the loading section 81, the plurality of supporting pins 81a and the conveying device 61 (see Figure 2 ) to deliver each substrate. In the placement section 81, each substrate is delivered by a plurality of support pins 81a and a conveying device (not shown) provided in the conveying region T1.

[0044] A pair of displacement sensors 82a and 82b are arranged in a vertical direction. Specifically, one displacement sensor 82a of the pair of displacement sensors 82a and 82b is arranged above the first substrate W1 and the second substrate W2 supported by the plurality of support pins 81a. In addition, the other displacement sensor 82b is arranged below the first substrate W1 and the second substrate W2 supported by the plurality of support pins 81a.

[0045] The displacement sensors 82a and 82b measure the warpage of the first substrate W1 and the second substrate W2. The displacement sensors 82a and 82b are, for example, laser displacement meters. The displacement sensors 82a and 82b irradiate laser light toward the first substrate W1 and the second substrate W2, and receive reflected light of the laser light. For example, the displacement sensors 82a and 82b measure the height of the bonding surface of the first substrate W1 and the height of the non-bonding surface of the first substrate W1 to measure the warpage of the first substrate W1.

[0046] The displacement sensor 82a is attached to the driving arm 82c. The displacement sensor 82b is attached to the driving arm 82d. The displacement sensors 82a and 82b are moved in the horizontal direction together with the driving arms 82c and 82d by an actuator (not shown).

[0047] The displacement sensors 82a and 82b measure the warping amounts of the first substrate W1 and the second substrate W2 while moving in the horizontal direction.

[0048] The warpage is the amount of protrusion of the central portion of the substrate relative to the peripheral portion of the substrate. The central portion is a predetermined area including the center of the substrate, and is a pre-set area. The peripheral portion is an area further outward than the central portion of the substrate in the radial direction of the substrate.

[0049] For example, when the bonding surface of the central portion of the first substrate W1 supported by the plurality of support pins 81 a protrudes upward relative to the bonding surface of the outer peripheral portion, the warpage amount is measured as a positive value.

[0050] In addition, when the bonding surface of the outer peripheral portion of the first substrate W1 supported by the plurality of support pins 81 a protrudes upward with respect to the bonding surface of the central portion, the warpage amount is measured as a negative value.

[0051] The load sensor 83 measures the friction coefficient of the non-bonding surface of the first substrate W1 and the non-bonding surface of the second substrate W2. The load sensor 83 is attached to the driving arm 83a. The load sensor 83 moves horizontally and vertically together with the driving arm 83a via an actuator (not shown).

[0052] The load sensor 83 is connected to the contact terminal 83c via the arm 83b. The contact terminal 83c is provided at the front end of the arm 83b. In addition, a plurality of load sensors 83 may be provided. For example, a load sensor for measuring the friction coefficient of the first substrate W1 and a load sensor for measuring the friction coefficient of the second substrate W2 may be provided. For example, the contact terminal 83c is formed of the same material as the pin 120 and the holding portion 211 described later.

[0053] The load sensor 83 measures the friction coefficient of the non-bonding surface of the first substrate W1 by, for example, pushing the contact terminal 83c against the non-bonding surface of the first substrate W1 and moving it in the horizontal direction. Specifically, the load sensor 83 measures the friction force when the contact terminal 83c moves in a manner of contacting the non-bonding surface of the first substrate W1, and measures the friction coefficient based on the force of pushing the contact terminal 83c against the first substrate W1 and the measured friction force.

[0054] In this manner, the conveying unit 80 temporarily puts the first substrate W1 , the second substrate W2 , and the superimposed substrate T on standby, and measures the warpage amounts of the first substrate W1 and the second substrate W2 and the friction coefficients of the first substrate W1 and the second substrate W2 .

[0055] <First Holding Mechanism and Second Holding Mechanism>

[0056] In addition, if Figure 4 As shown, the bonding device 41 includes a first holding mechanism 100 and a second holding mechanism 200 . Figure 4 1 is a schematic diagram showing a partial structure of a bonding apparatus 41 according to an embodiment. The first holding mechanism 100 and the second holding mechanism 200 are provided in the processing area T2 (see Figure 1 ).

[0057] The first holding mechanism 100 includes a rotation mechanism 101, a first height measuring unit 102, and a first suction cup unit 103. The first holding mechanism 100 sucks and holds the first substrate W1 by the first suction cup unit 103. Details of the first suction cup unit 103 will be described later.

[0058] The rotation mechanism 101 is attached to the top portion 41a of the processing container of the bonding device 41. The rotation mechanism 101 rotatably supports the first chuck unit 103. The rotation mechanism 101 rotates the first chuck unit 103 around an axis along the Z-axis direction.

[0059] The first height measuring unit 102 is mounted on the top 41a of the processing container. The first height measuring unit 102 may also be mounted on the rotating mechanism 101 or the first chuck unit 103. The first height measuring unit 102 measures the height of the bonding surface of the second substrate W2. In addition, the first height measuring unit 102 measures the thickness of the second substrate W2.

[0060] The first height measuring unit 102 is, for example, an alignment camera using a CCD camera. The first height measuring unit 102 photographs an alignment pattern provided on the second substrate W2, recognizes the alignment pattern, and measures the focused height as the height of the bonding surface of the second substrate W2. The first height measuring unit 102 measures the difference between the height of the bonding surface of the second substrate W2 and the height of the surface of the second suction cup unit 203 of the second holding mechanism 200 which is set in advance as the thickness of the second substrate W2.

[0061] The first height measuring unit 102 may be a displacement sensor. The displacement sensor is, for example, a laser displacement meter. The displacement sensor irradiates the second suction cup unit 203 and the second substrate W2 with a laser and receives reflected light from the laser, thereby measuring the height of the bonding surface of the second substrate W2 and the thickness of the second substrate W2. The first holding mechanism 100 may include an alignment camera and a displacement sensor as the first height measuring unit 102.

[0062] The second holding mechanism 200 includes a moving mechanism 201, a second height measuring unit 202, and a second chuck unit 203. The second holding mechanism 200 sucks and holds the second substrate W2 by the second chuck unit 203. Details of the second chuck unit 203 will be described later.

[0063] The moving mechanism 201 moves the second height measuring unit 202 and the second suction cup unit 203 in the horizontal direction and the vertical direction. The moving mechanism 201 includes a first moving mechanism 201a, a second moving mechanism 201b, and a third moving mechanism 201c.

[0064] The first moving mechanism 201a moves the second height measuring unit 202 and the second suction cup unit 203 along a guide rail provided at the bottom 41b of the processing container of the bonding device 41 and extending in the X-axis direction. The second moving mechanism 201b is installed on the upper part of the first moving mechanism 201a. The second moving mechanism 201b moves the second height measuring unit 202 and the second suction cup unit 203 along a guide rail provided on the upper surface of the first moving mechanism 201a and extending in the Y-axis direction. The third moving mechanism 201c is installed on the second moving mechanism 201b and is used to move the second height measuring unit 202 and the second suction cup unit 203 in the up-down direction.

[0065] The second height measuring unit 202 is attached to the second chuck unit 203. The second height measuring unit 202 measures the height of the bonding surface of the first substrate W1. In addition, the second height measuring unit 202 measures the thickness of the first substrate W1. The second height measuring unit 202 is an alignment camera and a displacement sensor similar to the first height measuring unit 102.

[0066] <First Suction Cup Section>

[0067] Next, refer to Figure 5The first suction cup portion 103 will be described. Figure 5 1 is a schematic diagram showing the structure of the first suction cup unit 103 and the second suction cup unit 203 according to the embodiment.

[0068] The first suction cup portion 103 includes a supporting portion 110 , a holding portion 111 , a first suction portion 112 , a second suction portion 113 , and a deforming portion 114 .

[0069] The support portion 110 is rotatably mounted on the rotating mechanism 101 (see Figure 4 The support portion 110 is formed in a circular shape. A receiving chamber 110 a for receiving the deforming portion 114 is formed in the support portion 110 . The receiving chamber 110 a is formed in the center of the support portion 110 .

[0070] The holding portion 111 is mounted on the lower surface of the supporting portion 110 and fixed to the supporting portion 110. The holding portion 111 is formed in a circular shape. A plurality of pins 120 are provided on the lower surface of the holding portion 111. The plurality of pins 120 contact the upper surface of the first substrate W1, that is, the non-bonding surface of the first substrate W1 to hold the first substrate W1. The holding portion 111 holds the first substrate W1 by adsorbing the non-bonding surface of the first substrate W1 (an example of a substrate).

[0071] The first and second suction parts 112 and 113 perform vacuuming, thereby sucking the first substrate W1 and holding it on the holding part 111. That is, the holding part 111 (an example of a first holding part) holds the first substrate W1 (an example of a substrate) to be bonded.

[0072] An outer rib 121 and an inner rib 122 are provided on the lower surface of the holding portion 111. The outer rib 121 contacts the upper surface of the first substrate W1, that is, the outer peripheral portion of the non-bonding surface of the first substrate W1. The outer rib 121 is at the same height position as the pin 120. The outer rib 121 is provided at a position further outward than the pin 120 in the radial direction of the first substrate W1. The outer rib 121 is formed in an annular shape along the periphery of the first substrate W1.

[0073] The inner rib 122 contacts the upper surface of the first substrate W1. The inner rib 122 is provided at a position further inward than the outer rib 121 in the radial direction of the first substrate W1. The inner rib 122 is at the same height position as the outer rib 121, i.e., the pin 120. The inner rib 122 is formed in an annular shape and is formed concentrically with the outer rib 121.

[0074] The area inside the outer rib 121 is divided into a first suction area 123a and a second suction area 123b. The first suction area 123a is the area inside the inner rib 122 in the radial direction of the first substrate W1. The second suction area 123b is the area outside the inner rib 122 in the radial direction of the first substrate W1.

[0075] The holding portion 111 is formed with a first suction hole 124a, a second suction hole 124b, and an insertion hole 124c. The first suction hole 124a is connected to the first suction region 123a. A plurality of first suction holes 124a are formed. The second suction hole 124b is connected to the second suction region 123b. A plurality of second suction holes 124b are formed. The insertion hole 124c is formed at the center of the holding portion 111, and a front end of an actuator 114a of the deformation portion 114 described later is inserted therein.

[0076] A temperature sensor 126 for measuring the temperature of the first substrate W1 is provided on the lower surface of the holding portion 111. The temperature sensor 126 is in contact with the upper surface of the first substrate W1, that is, the non-bonding surface of the first substrate W1. A plurality of temperature sensors 126 are provided. For example, the temperature of the first substrate W1 is an average value of the temperatures measured by the plurality of temperature sensors 126. Only one temperature sensor 126 may be provided.

[0077] The temperature sensor 126 may be disposed at a location not in contact with the non-bonding surface of the first substrate W1. The temperature sensor 126 may measure the temperature of a location related to the temperature of the first substrate W1, such as the holding portion 111 or the pin 120, and estimate the temperature of the first substrate W1 based on the measured temperature.

[0078] The first suction portion 112 is connected to the first suction hole 124a. The first suction portion 112 is, for example, a vacuum pump. By using the first suction portion 112 to evacuate, the first suction region 123a is depressurized.

[0079] The second suction part 113 is connected to the second suction hole 124b. The second suction part 113 is, for example, a vacuum pump. By using the second suction part 113 to evacuate, the second suction area 123b is depressurized.

[0080] The first suction region 123a is depressurized by the first suction portion 112, and the second suction region 123b is depressurized by the second suction portion 113, so that the first substrate W1 is held by suction on the holding portion 111. The first suction portion 112 and the second suction portion 113 of the first suction cup portion 103 can be vacuumed separately. That is, the suction force on the first substrate W1 can be adjusted according to the first suction region 123a and the second suction region 123b.

[0081] The deformation part 114 is provided in the accommodation chamber 110a formed in the support part 110. A part of the deformation part 114 may be provided in the rotation mechanism 101 (refer to Figure 4 ). The deformation portion 114 includes an actuator 114a and a cylinder 114b.

[0082] The actuator 114a generates a fixed pressure in a fixed direction by air supplied from an electric pneumatic regulator (not shown). The actuator 114a can generate a fixed pressure regardless of the position of the pressure point. The front end of the actuator 114a abuts against the central part of the upper surface of the first substrate W1, and the pressing load applied to the central part of the first substrate W1 can be controlled.

[0083] The cylinder 114b supports the actuator 114a. The cylinder 114b moves the actuator 114a in the vertical direction by a driving unit including, for example, a motor.

[0084] The deformation part 114 controls the pressing load on the first substrate W1 through the actuator 114a, and controls the movement of the actuator 114a through the cylinder 114b. The deformation part 114 presses downward the central part of the first substrate W1 adsorbed and held by the holding part 111 to bend the first substrate W1 downward. That is, the deformation part 114 (an example of a first deformation part) causes the central part of the first substrate W1 (an example of a substrate) held by the holding part 111 (an example of a first holding part) to protrude relative to the outer peripheral part of the first substrate. The deformation part 114 can adjust the protrusion amount of the central part of the first substrate W1 by controlling the movement amount of the actuator 114a.

[0085] <Second Suction Cup Section>

[0086] Next, the second suction cup unit 203 will be described. The second suction cup unit 203 includes a base unit 210, a holding unit 211, a suction unit 212, and a deformation unit 213.

[0087] The base part 210 is mounted on the third moving mechanism 201c (see Figure 4 The base part 210 has a circular shape. A receiving chamber 210 a for receiving the measuring part 240 is formed in the base part 210 . The receiving chamber 210 a is formed in the center of the base part 210 .

[0088] An insertion hole 210b is formed in the base part 210. The insertion hole 210b communicates with the storage chamber 210a. The insertion hole 210b is formed in the center of the base part 210. In addition, the base part 210 is provided with a suction pipe 210c and an intake and exhaust pipe 210d.

[0089] A plurality of suction pipes 210c are provided. Alternatively, a single suction pipe 210c may be provided. A seal such as a V-ring is provided around the suction pipe 210c. The suction pipe 210c is provided to reach the holding portion 211. A seal such as a V-ring is provided around the suction and exhaust pipes 210d.

[0090] The holding part 211 is provided above the base part 210. The holding part 211 is circular. A fixing ring 242 is provided around the holding part 211. The holding part 211 is fixed to the base part 210 by the fixing ring 242.

[0091] The holding portion 211 is formed of a ceramic material such as alumina ceramics, silicon carbide, etc. The holding portion 211 is retractable in the vertical direction and the horizontal direction. The holding portion 211 can realize a high-precision flat surface and high restorability.

[0092] The upper surface of the holding portion 211 is circular. The diameter of the upper surface of the holding portion 211 is larger than the diameter of the second substrate W2. The thickness of the central portion of the holding portion 211 is larger than the thickness of the peripheral portion. Ribs 211a are provided on the lower surface of the holding portion 211. The ribs 211a abut against the base portion 210 when the upper surface of the holding portion 211 is horizontal. A variable pressure space 243 is formed between the lower surface of the holding portion 211 and the upper surface of the base portion 210.

[0093] A suction tube 210c is provided in the holding portion 211. A sealing member, such as a V-ring, is provided around the suction tube 210c. The suction portion 212 performs vacuuming via the suction tube 210c, thereby causing the second substrate W2 to be adsorbed and held on the holding portion 211. The holding portion 211 holds the second substrate W2 (an example of a substrate) by adsorbing the non-bonding surface of the second substrate W2 (an example of a substrate). That is, the holding portion 211 (an example of a second holding portion) holds the second substrate W2 (an example of a substrate) to be bonded to the first substrate W1.

[0094] A temperature sensor 244 for measuring the temperature of the second substrate W2 is provided in the holding portion 211. The temperature sensor 244 is in contact with the lower surface of the second substrate W2, that is, the non-bonding surface of the second substrate W2. A plurality of temperature sensors 244 are provided. For example, the temperature of the second substrate W2 is an average value of the temperatures measured by the plurality of temperature sensors 244. Alternatively, a single temperature sensor 244 may be provided.

[0095] The temperature sensor 244 measures the temperature of a portion related to the temperature of the second substrate W2, such as the lower surface of the holding portion 211, and estimates the temperature of the second substrate W2 based on the measured temperature.

[0096] The suction part 212 is connected to the suction pipe 210c. The suction part 212 is, for example, a vacuum pump. The suction part 212 is used to evacuate the air between the lower surface of the second substrate W2, i.e., the non-bonding surface, and the holding part 211. The suction part 212 sucks the air between the lower surface of the second substrate W2 and the holding part 211, so that the second substrate W2 is held by the holding part 211.

[0097] The deformation unit 213 includes a vacuum pump 220 and an electro-pneumatic regulator 221 .

[0098] The vacuum pump 220 is connected to the suction and exhaust pipe 210d via the switching valve 222. The vacuum pump 220 performs vacuuming, thereby reducing the pressure of the variable pressure space 243. By reducing the pressure of the variable pressure space 243, the rib 211a of the holding part 211 abuts against the base part 210. In this case, the upper surface of the holding part 211 is horizontal.

[0099] The electro-pneumatic regulator 221 is connected to the air intake and exhaust pipe 210d via the switching valve 222. The electro-pneumatic regulator 221 supplies air to the variable pressure space 243 to pressurize the variable pressure space 243. As a result, the holding portion 211 is pressed from below. The outer peripheral portion of the holding portion 211 is fixed to the base portion 210 by the fixing ring 242. Therefore, by pressing from below, the central portion of the holding portion 211 protrudes upward relative to the outer peripheral portion.

[0100] The switching valve 222 switches the connection state between the intake and exhaust pipe 210 d , the vacuum pump 220 , and the electro-pneumatic regulator 221 .

[0101] The deforming portion 213 pressurizes the variable pressure space 243 to cause the central portion of the holding portion 211 to protrude upward. As a result, the central portion of the second substrate W2 held by adsorption on the holding portion 211 protrudes upward, and the second substrate W2 bends. That is, the deforming portion 213 causes the central portion of the second substrate W2 (an example of a substrate) held by the holding portion 211 to protrude relative to the outer periphery of the second substrate W2. The deforming portion 213 can adjust the protrusion amount of the central portion of the second substrate W2 by adjusting the pressure of the variable pressure space 243.

[0102] The measuring unit 240 measures the protrusion of the holding unit 211, that is, the protrusion of the center of the second substrate W2. The measuring unit 240 is, for example, a capacitance sensor. The capacitance sensor measures the change in capacitance formed between the sensor surface and the measurement target 240a as the distance between the sensor surface and the measurement target 240a.

[0103] The measurement target 240a is attached to the center of the lower surface of the holding part 211, and moves in the vertical direction together with the holding part 211. The measurement target 240a is inserted into the insertion hole 210b of the base part 210. A seal (not shown), such as a V-ring, is provided around the measurement target 240a.

[0104] The bonding device 41 bends the first substrate W1 by the first suction cup part 103 so that the center portion of the first substrate W1 protrudes downward, and bends the second substrate W2 by the second suction cup part 203 so that the center portion of the second substrate W2 protrudes upward.

[0105] Moreover, the bonding device 41 bonds the first substrate W1 and the second substrate W2 to form the overlapping substrate T. At this time, by bending the first substrate W1 and the second substrate W2, sometimes the first substrate W1 and the second substrate W2 extend in the radial direction, resulting in a scaling error.

[0106] The scaling error is the amount of extension in the horizontal direction of the substrate, and is the magnification ratio in the radial direction based on the center of the substrate. When the first substrate W1 and the second substrate W2 are bonded in a state where a scaling error has occurred, due to the influence of the scaling error, the bonding accuracy of the overlapping substrate T may decrease.

[0107] <Amount of extension of the substrate>

[0108] Here, the extension of the bonding surface of the bent substrate will be described. Here, the second substrate W2 will be described as an example. Let the diameter of the second substrate W2 in the unbent state be "Dw", and the thickness of the second substrate W2 be "t". In addition, let the radius of the upper surface of the holding portion 211 in the horizontal state be "Rc", and the radius of curvature of the upper surface of the holding portion 211 in the bent state be "R".

[0109] In this case, as Figure 6 shown, the second substrate W2 is bent at an angle "θ [rad]". Figure 6 is a schematic diagram showing the state in which the second substrate W2 according to the embodiment is bent. In the bent second substrate W2, the lower surface (non-bonding surface) side of the second substrate W2 shrinks, and the upper surface (bonding surface) side of the second substrate W2 extends. Let the amount of extension of the upper surface of the second substrate W2 be "ΔS (ppm)".

[0110] When it is assumed that there is a neutral surface without extension and contraction at a position "a×t" (0 < a < 1) from the lower surface of the second substrate W2, that is, the upper surface of the holding portion 211, the arc length of the neutral surface is the diameter "Dw" of the second substrate W2 in the unbent state, and Equation (1) holds.

[0111] Dw = (R + a×t)×θ...(1)

[0112] In addition, the length "Dw + ΔS×Dw" of the upper surface of the bent second substrate W2 is expressed by Equation (2).

[0113] Dw + ΔS×Dw = (R + t)×θ...(2)

[0114] Substitute "Dw" in Equation (1) into "Dw" in Equation (2) and summarize, the amount of extension "ΔS" is Equation (3).

[0115] ΔS = (t - a×t) / (R + a×t)...(3)

[0116] Formula (3) is transformed into Formula (4) by the curvature radius "R".

[0117] R=t×(1-aa×ΔS) / ΔS…(4)

[0118] Here, the term "a×ΔS" in equation (4) is of the order of 10 -6 The product of "ΔS" and "a" is very small compared to other terms. Therefore, the term "a×ΔS" in equation (4) is omitted and transformed to equation (5).

[0119] ΔS=(1-a)×t / R…(5)

[0120] According to formula (5), the extension amount "ΔS" of the bonding surface of the second substrate W2 is proportional to the thickness "t" of the second substrate W2. As such, the extension of the bonding surface of the second substrate W2 is affected by the thickness of the second substrate W2. That is, the scaling error of the substrate is affected by the thickness of the substrate.

[0121] <Suppression of scaling error caused by substrate thickness>

[0122] Next, a method for suppressing the scaling error caused by the thickness of the substrate is described. Here, the generation of scaling errors relative to a substrate serving as a reference (hereinafter referred to as a "reference substrate") is suppressed. The reference substrate is a substrate in which the scaling error in the overlapping substrate T is less than a preset reference value. In addition, the second substrate W2 is used as an example of a substrate for description.

[0123] When the thickness of the reference substrate is set to "t0" and the reference substrate is bent to a curvature radius "R0", based on the formula (5), the extension amount "ΔS0" of the bonding surface of the reference substrate is expressed by the formula (6).

[0124] ΔS0=(1-a)×t0 / R0…(6)

[0125] In addition, by changing the curvature radius of the second substrate W2, the bonding surface of the second substrate W2 with a thickness of "t1" can be extended by "ΔS0" similar to the reference substrate. Here, the curvature radius of the changed second substrate W2 is set to "R1", which is expressed as formula (7).

[0126] ΔS0=(1-a)×t1 / R1…(7)

[0127] Based on equation (6) and equation (7), equation (8) holds.

[0128] t0 / R0=t1 / R1…(8)

[0129] Assuming that the ratio of the thickness “t0” of the reference substrate to the thickness “t1” of the second substrate W2 is “A (= t0 / t1)”, equation (8) is transformed into equation (9).

[0130] R1=A×R0…(9)

[0131] The radius of curvature "R1" of the second substrate W2 is set to the radius of curvature obtained by multiplying the radius of curvature "R0" of the reference substrate by the ratio "A" of the thickness "t0" of the reference substrate to the thickness "t1" of the second substrate W2. In this way, the extension amount of the bonding surface of the second substrate W2 can be equal to the extension amount "ΔS0" of the bonding surface of the reference substrate.

[0132] In addition, Figure 6 , the deformation amount, i.e., the protrusion amount, of the upper surface of the holding portion 211 is set to "h". In this case, the relationship of formula (10) holds true between the protrusion amount "h" of the upper surface of the holding portion 211, the radius "Rc" of the upper surface of the holding portion 211 in the horizontal state, and the curvature radius "R" of the upper surface of the curved holding portion 211.

[0133] R 2 =Rc 2 +(Rh) 2 …(10)

[0134] Transform equation (10) into equation (11).

[0135] h=R-(R 2 -Rc 2 ) 1 / 2 …(11)

[0136] Based on the formula (9), "R1" is calculated, and the calculated "R1" is substituted into "R" of the formula (11), thereby calculating the protrusion amount of the upper surface of the holding portion 211 that makes the extension amount of the bonding surface of the second substrate W2 equal to the extension amount "ΔS0" of the bonding surface of the reference substrate. In other words, the protrusion amount of the central portion of the second substrate W2 that makes the extension amount of the bonding surface of the second substrate W2 equal to the extension amount "ΔS0" of the bonding surface of the reference substrate can be calculated.

[0137] In addition, the radius "Rc" of the upper surface of the holding portion 211 in the horizontal state is fixed regardless of the second substrate W2 and is a known value. In addition, the radius of curvature "R0" of the reference substrate and the thickness "t0" of the reference substrate are values ​​calculated based on the reference substrate, or are values ​​known by setting. Therefore, by measuring the thickness "t1" of the second substrate W2, the protrusion amount of the central portion of the second substrate W2 can be calculated.

[0138] By setting the height of the center portion of the holding portion 211 to the calculated protrusion amount "h", the extension of the bonding surface of the second substrate W2 can be made equal to that of the reference substrate regardless of the thickness of the second substrate W2. That is, the occurrence of scaling error with respect to the reference substrate can be suppressed.

[0139] <Suppression of Scaling Error Due to Substrate Temperature>

[0140] The substrate expands or contracts according to the temperature of the substrate, which may cause a scaling error of the substrate. Next, a method for suppressing the scaling error caused by the temperature of the substrate is described. Here, the generation of a scaling error relative to a reference substrate is suppressed. In addition, the second substrate W2 is used as an example of a substrate for description.

[0141] The temperature change of the second substrate W2 relative to the reference substrate is defined as "ΔT", and the extension amount of the bonding surface of the second substrate W2 caused by the temperature change is defined as "ΔSt". In this case, the extension amount "ΔSt" of the bonding surface of the second substrate W2 is expressed by equation (12).

[0142] ΔSt=b×c×ΔT…(12)

[0143] "b" is the thermal expansion coefficient of the base material of the second substrate W2. "c" is a value obtained by correcting the thermal expansion coefficient of the base material of the second substrate W2 by the influence of the film formed on the second substrate W2. "b" and "c" are set in advance by experiments or the like.

[0144] In addition, when the extension amount "ΔSt" of the bonding surface of the second substrate W2 caused by temperature change is set to "B" times the extension amount "ΔS0" of the bonding surface of the reference substrate, the extension amount "ΔSt" of the bonding surface of the second substrate W2 is expressed by formula (13).

[0145] ΔSt=B×ΔS0…(13)

[0146] When the second substrate W2 has a scaling error due to temperature, when the adjustment amount for making the extension amount of the bonding surface of the second substrate W2 the same as the extension amount "ΔS0" of the bonding surface of the reference substrate is set to "ΔSc1", equation (14) holds.

[0147] ΔS0=ΔSt+ΔSc1…(14)

[0148] Substituting "ΔSt" in equation (13) into "ΔSt" in equation (14) and transforming the equation, the equation (15) is obtained.

[0149] ΔSc1=(1-B)×ΔS0…(15)

[0150] In addition, the curvature radius of the second substrate W2 for extending the bonding surface of the second substrate W2 having the same thickness "t0" as the reference substrate by an adjustment amount "ΔSc1" is set to "R1". In this case, based on equation (6), the adjustment amount "ΔSc1" is expressed by equation (16).

[0151] ΔSc1=(1-a)×t0 / R1…(16)

[0152] Substituting "ΔSc1" in equation (16) into "ΔSc1" in equation (15), and substituting "ΔS0" in equation (6) into "ΔS0" in equation (15), equation (17) is obtained.

[0153] (1-a)×t0 / R1=(1-B)×(1-a)×t0 / R0…(17)

[0154] Transform equation (17) into equation (18).

[0155] R1=(1 / (1-B))×R0…(18)

[0156] Based on formula (18), the radius of curvature "R1" of the second substrate W2 is set to the radius of curvature obtained by multiplying the radius of curvature "R0" of the reference substrate by a specified value "1 / (1-B)". Thus, regardless of the temperature of the second substrate W2, the extension amount of the bonding surface of the second substrate W2 can be equal to the extension amount "ΔS0" of the bonding surface of the reference substrate.

[0157] In addition, "B" can be calculated by the following method. First, the temperature of the second substrate W2 is measured, and the temperature change "ΔT" relative to the temperature of the reference substrate is calculated. Then, based on the calculated temperature change "ΔT", the extension amount "ΔSt" of the bonding surface of the second substrate W2 is calculated according to formula (13). Then, based on the calculated extension amount "ΔSt" of the bonding surface of the second substrate W2 and the extension amount "ΔS0" of the bonding surface of the reference substrate, "B" is calculated according to formula (14). The extension amount "ΔS0" of the bonding surface of the reference substrate is pre-calculated or pre-measured, so that the extension amount "ΔS0" is known.

[0158] In addition, "R1" is calculated based on formula (18), and the calculated "R1" is substituted into "R" of formula (11). Thus, the protrusion amount of the upper surface of the holding portion 211 for making the extension amount of the bonding surface of the second substrate W2 equal to the extension amount "ΔS0" of the bonding surface of the reference substrate can be calculated regardless of the temperature of the second substrate W2. That is, the protrusion amount of the central portion of the second substrate W2 for making the extension amount of the bonding surface of the second substrate W2 equal to the extension amount "ΔS0" of the bonding surface of the reference substrate can be calculated.

[0159] By setting the height of the center portion of the holding portion 211 to the calculated protrusion amount "h", the extension of the bonding surface of the second substrate W2 can be made equal to that of the reference substrate regardless of the temperature of the second substrate W2. That is, the scaling error caused by the temperature of the second substrate W2 relative to the reference substrate can be suppressed.

[0160] <Suppression of scaling errors caused by substrate warping>

[0161] When the substrate whose bonding surface at the center portion protrudes more than the bonding surface at the periphery portion is adsorbed and held, for example, the second substrate W2 is adsorbed and held from a state where the periphery portion of the second substrate W2 is in contact with the upper surface of the holding portion 211. At this time, when the friction force between the periphery portion and the upper surface of the holding portion 211 is large, the second substrate W2 is suppressed from deforming radially outward and is adsorbed to the holding portion 211. Therefore, for example, the second substrate W2 whose bonding surface at the periphery portion protrudes more than the bonding surface at the center portion may be further contracted and adsorbed and held to the holding portion 211. That is, a scaling error of the substrate may occur due to the warping of the substrate.

[0162] Next, a method for suppressing the scaling error caused by the warping of the substrate will be described. Here, the generation of the scaling error relative to the reference substrate is suppressed. In addition, the second substrate W2 is used as an example of the substrate for description.

[0163] The warpage amount of the reference substrate is set to "W0", and the friction coefficient of the reference substrate is set to "μ0". In addition, the warpage amount of the second substrate W2 different from the reference substrate is set to "W1", and the friction coefficient of the second substrate W2 is set to "μ1". In this case, the influence of the warpage of the second substrate W2 on the extension amount of the bonding surface (hereinafter referred to as "extension amount") "ΔSw" is expressed by formula (19).

[0164] ΔSw=d×(W1 / W0)×(μ1 / μ0)…(19)

[0165] “d” is a preset correction factor.

[0166] In addition, when the extension amount "ΔSw" of the second substrate W2 caused by the warping of the second substrate W2 is set to "C" times the extension amount "ΔS0" of the bonding surface of the reference substrate, the extension amount "ΔSw" of the bonding surface of the second substrate W2 is expressed by formula (20).

[0167] ΔSw=C×ΔS0…(20)

[0168] When the second substrate W2 has a scaling error caused by warping, when the adjustment amount for making the extension amount of the bonding surface of the second substrate W2 the same as the extension amount "ΔS0" of the bonding surface of the reference substrate is set to "ΔSc1", equation (21) holds.

[0169] ΔS0=ΔSw+ΔSc1…(21)

[0170] Substituting "ΔSw" in equation (20) into "ΔSw" in equation (21) and transforming the equation, the equation (22) is obtained.

[0171] ΔSc1=(1-C)×ΔS0…(22)

[0172] In addition, the curvature radius of the second substrate W2 for extending the bonding surface of the second substrate W2 having the same thickness "t0" as the reference substrate by an adjustment amount "ΔSc1" is set to "R1". In this case, based on equation (6), the adjustment amount "ΔSc1" is expressed by equation (23).

[0173] ΔSc1=(1-a)×t0 / R1···(23)

[0174] Substituting "ΔSc1" in equation (22) into "ΔSc1" in equation (23), and substituting "ΔS0" in equation (6) into "ΔS0" in equation (22), we obtain equation (24).

[0175] (1-a)×t0 / R1=(1-C)×(1-a)×t0 / R0…(24)

[0176] Transform equation (24) into equation (25).

[0177] R1=(1 / (1-C))×R0…(25)

[0178] Based on formula (26), the radius of curvature "R1" of the second substrate W2 is set to the radius of curvature obtained by multiplying the radius of curvature "R0" of the reference substrate by a specified value "1 / (1-C)". Thus, regardless of the warping of the second substrate W2, the extension amount of the bonding surface of the second substrate W2 can be equal to the extension amount "ΔS0" of the bonding surface of the reference substrate.

[0179] In addition, "C" can be calculated by the following method. First, the warping amount "W1" of the second substrate W2 and the friction coefficient "μ1" of the second substrate W2 are measured, and the extension amount "ΔSw" of the bonding surface of the second substrate W2 is calculated based on formula (19). The warping amount "W0" of the reference substrate and the friction coefficient "μ0" of the reference substrate are known values.

[0180] Alternatively, a substrate without warping may be used as a reference substrate, and the extension amount "ΔSw" of the bonding surface of the second substrate W2 may be calculated by calculating the ratio of the protrusion amount of the second substrate W2 in which the center of the bonding surface protrudes more than the outer periphery of the bonding surface relative to the reference substrate.

[0181] Then, based on the calculated extension amount “ΔSw” of the bonding surface of the second substrate W2 and the calculated extension amount “ΔS0” of the bonding surface of the reference substrate, “C” is calculated according to equation (20).

[0182] In addition, "R1" is calculated based on formula (25), and the calculated "R1" is substituted into "R" of formula (11). Thus, the protrusion amount of the upper surface of the holding portion 211 for making the extension amount of the bonding surface of the second substrate W2 equal to the extension amount "ΔS0" of the bonding surface of the reference substrate can be calculated regardless of the warping of the second substrate W2. In other words, the protrusion amount of the central portion of the second substrate W2 for making the extension amount of the bonding surface of the second substrate W2 equal to the extension amount "ΔS0" of the bonding surface of the reference substrate can be calculated.

[0183] By setting the height of the central portion of the holding portion 211 to the calculated protrusion amount "h", the extension of the bonding surface of the second substrate W2 can be made equal to that of the reference substrate regardless of the warping of the second substrate W2. That is, the scaling error caused by the warping of the second substrate W2 relative to the reference substrate can be suppressed.

[0184] <Summary of Scaling Error Suppression>

[0185] The suppression of the occurrence of the scaling error due to the thickness of the substrate, the temperature of the substrate, and the warpage of the substrate described above will be summarized as follows: In addition, the second substrate W2 will be described as an example of the substrate.

[0186] The adjustment amount for making the second substrate W2 having a thickness of "t1", an extension amount due to temperature of "ΔSt", and an extension amount due to warping of "ΔSw" equal to the extension amount "ΔS0" of the reference substrate is set to "Sc1", and equation (26) holds. In addition, the adjustment amount "Sc1" is the adjustment amount caused by the thickness "t1" of the second substrate W2.

[0187] ΔS0=ΔSc1+ΔSt+ΔSw…(26)

[0188] Formula (26) is transformed into formula (27).

[0189] ΔSc1=ΔS0-ΔSt-ΔSw…(27)

[0190] Substituting "ΔSt" in equation (13) into equation (27), substituting "ΔSW" in equation (20) into "ΔSw" in equation (27), and summing up, we obtain equation (28).

[0191] ΔSc1=(1-BC)×ΔS0…(28)

[0192] Here, when the bonding surface of the second substrate W2 with a thickness of "t1" is extended by "ΔS0", the relationship of formula (7) holds, so "ΔSc1" in formula (28) can be replaced by the right side of formula (7). In addition, "ΔS0" can be expressed as formula (6). Based on these, formula (28) is deformed to become formula (29).

[0193] (1-a)×t1 / R1=(1-BC)×(1-a)×t0 / R0…(29)

[0194] In addition, equation (29) is transformed using "A (= t0 / t1)" to obtain equation (30).

[0195] R1=A×(1-BC)×R0…(30)

[0196] Based on formula (30), the radius of curvature "R1" of the second substrate W2 is set to the radius of curvature obtained by multiplying the radius of curvature "R0" of the reference substrate by a specified value "A×(1-BC)". Thus, regardless of the thickness, temperature, and warping of the second substrate W2, the extension amount of the bonding surface of the second substrate W2 can be equal to the extension amount "ΔS0" of the bonding surface of the reference substrate.

[0197] In addition, by calculating "R1" based on equation (30), and substituting the calculated "R1" into "R" of equation (11), it is possible to calculate the protrusion amount "h" of the upper surface of the holding portion 211. That is, it is possible to calculate the protrusion amount of the central portion of the second substrate W2 for making the extension amount of the bonding surface of the second substrate W2 equal to the extension amount "ΔS0" of the bonding surface of the reference substrate.

[0198] By setting the height of the center portion of the holding portion 211 to the calculated deformation amount “h”, the extension of the bonding surface of the second substrate W2 can be made equal to that of the reference substrate regardless of the thickness, temperature, and warpage of the second substrate W2 .

[0199] Such adjustment of the height of the upper surface of the holding portion 211 , that is, adjustment of the protrusion amount of the central portion of the second substrate W2 is performed for each second substrate W2 .

[0200] Furthermore, in the case where the second substrate W2 is a substrate in which the outer periphery of the bonding surface protrudes more than the central portion of the bonding surface, the deformation amount "h" of the upper surface of the holding portion 211 can be calculated without using the extension amount "ΔSw" caused by warping. That is, in the case of the second substrate W2 in which the outer periphery of the bonding surface protrudes more than the central portion of the bonding surface, the protrusion amount of the central portion of the second substrate W2 can be adjusted without using the extension amount "ΔSw" caused by warping. That is, when the second substrate W2 (an example of a substrate) is warped in a state in which the bonding surface of the peripheral portion protrudes more than the bonding surface of the central portion when not being held by the holding portion 211, the protrusion amount is adjusted for each second substrate W2 based on at least one of the thickness of the second substrate W2 and the temperature of the second substrate W2.

[0201] The bonding device 41 can adjust the protrusion amount of the second substrate W2 by the deformation portion 213 for each second substrate W2 based on at least one of the thickness of the second substrate W2, the temperature of the second substrate W2, and the warping of the second substrate W2. For example, the bonding device 41 can adjust the protrusion amount of the second substrate W2 for each second substrate W2 based on the temperature of the second substrate W2.

[0202] Here, as an example, the second substrate W2 is described, but the protrusion amount of the central portion of the first substrate W1 is adjusted for each first substrate W1 in the same manner as for the first substrate W1. In the first substrate W1, the amount of movement of the actuator 114a by the cylinder 114b of the deformation portion 114 corresponds to the protrusion amount of the upper surface of the holding portion 211 described above. In addition, the radius of the inner rib 122 corresponds to the radius of the upper surface of the holding portion 211 in the horizontal state described above.

[0203] <Joining Process>

[0204] Next, refer to Figure 7 The joining process involved in the implementation method is explained with reference to the flowchart of FIG. Figure 7 The following is a flowchart for explaining the joining process according to the embodiment. Figure 7 Various treatments shown.

[0205] The thickness, temperature, warpage, and friction coefficient of the reference substrate in the first substrate W1 are stored in advance in the storage unit 70b. The thickness, temperature, warpage, and friction coefficient of the reference substrate in the second substrate W2 are stored in advance in the storage unit 70b.

[0206] The control device 70 performs a first measurement process (S100). Specifically, the control device 70 transports the first substrate W1 that has been surface-modified by the surface modification device 30 and hydrophilized by the surface hydrophilization device 40 to the conveying unit 80. Furthermore, the control device 70 measures the warpage of the first substrate W1 transported to the conveying unit 80 through the displacement sensors 82a and 82b. In addition, the control device 70 measures the friction coefficient of the first substrate W1 through the load sensor 83. The first substrate W1 that has been subjected to the first measurement process is adjusted in a horizontal direction by a position adjustment mechanism, flipped by a flipping mechanism, and then held by adsorption by the first suction cup unit 103.

[0207] The control device 70 performs the second measurement process (S101). Specifically, the control device 70 transports the second substrate W2 that has been surface-modified by the surface modification device 30 and hydrophilized by the surface hydrophilization device 40 to the conveying unit 80. Furthermore, the control device 70 measures the warpage of the second substrate W2 transported to the conveying unit 80 through the displacement sensors 82a and 82b. In addition, the control device 70 measures the friction coefficient of the second substrate W2 through the load sensor 83. The second substrate W2 that has been subjected to the second measurement process is adjusted in the horizontal direction by the position adjustment mechanism, and then is held by the second suction cup unit 203.

[0208] Furthermore, the order of the first measurement process and the second measurement process may be reversed, or some of the processes may be executed simultaneously.

[0209] The control device 70 performs a third measurement process (S102). Specifically, the control device 70 measures the thickness of the first substrate W1 and the thickness of the second substrate W2. The control device 70 measures the thickness of the second substrate W2 by the first height measuring unit 102. In addition, the control device 70 measures the thickness of the first substrate W1 by the second height measuring unit 202.

[0210] The control device 70 performs a fourth measurement process ( S103 ). Specifically, the control device 70 measures the temperature of the first substrate W1 using the temperature sensor 126 . In addition, the control device 70 measures the temperature of the second substrate W2 using the temperature sensor 244 .

[0211] Furthermore, the third measurement process and the fourth measurement process may be performed in reverse order or simultaneously.

[0212] The control device 70 sets the protrusion amount of the first substrate W1 (S104). Specifically, the control device 70 sets the movement amount of the actuator 114a based on the thickness, temperature and warpage of the first substrate W1, and sets the protrusion amount of the center portion of the first substrate W1.

[0213] The control device 70 sets the protrusion amount of the second substrate W2 (S105). Specifically, the control device 70 sets the protrusion amount of the holding portion 211 based on the thickness of the second substrate W2, the temperature of the second substrate W2, and the warpage of the second substrate W2, and sets the protrusion amount of the central portion of the second substrate W2.

[0214] In addition, the order of setting the protrusion amount of the first substrate W1 and the order of setting the protrusion amount of the second substrate W2 may be reversed or may be performed simultaneously.

[0215] The control device 70 performs a bonding process ( S106 ) Specifically, the control device 70 adjusts the positions of the first substrate W1 and the second substrate W2 in the vertical direction after adjusting the positions of the first substrate W1 and the second substrate W2 in the horizontal direction.

[0216] The control device 70 adjusts the vertical positions of the first substrate W1 and the second substrate W2 so that the center portion of the first substrate W1 abuts against and is pressed against the center portion of the second substrate W2 while bending the first substrate W1 and the second substrate W2 to achieve set protrusion amounts.

[0217] Furthermore, the control device 70 causes the central portion of the first substrate W1 to protrude and causes the central portion of the second substrate W2 to protrude, as shown in FIG. Figure 8 As shown, the center portion of the first substrate W1 is brought into contact with the center portion of the second substrate W2. Figure 8 The diagram shows a state in which the first substrate W1 and the second substrate W2 are bent in the bonding process according to the embodiment. In addition, the control device 70 stops the suction of the first suction portion 112 of the first chuck portion 103 .

[0218] The control device 70, specifically the control unit 70a, adjusts the protrusion amount of the first substrate W1 caused by the deformation unit 114 for each first substrate W1 based on at least one of the thickness of the first substrate W1 (an example of a substrate), the temperature of the first substrate W1, and the warping of the first substrate W1 when not held by the holding unit 111.

[0219] Specifically, the control device 70 adjusts the protrusion amount for each first substrate W1 based on at least one of the thickness of the first substrate W1 relative to the reference substrate, the temperature of the first substrate W1 relative to the reference substrate, and the warpage of the first substrate W1 relative to the reference substrate.

[0220] In addition, the control device 70, specifically the control unit 70a, adjusts the protrusion amount of the second substrate W2 caused by the deformation unit 213 for each second substrate W2 based on at least one of the thickness of the second substrate W2 (an example of a substrate), the temperature of the second substrate W2, and the warping of the second substrate W2 when not held by the holding unit 211.

[0221] Specifically, the control device 70 adjusts the protrusion amount for each second substrate W2 based on at least one of the thickness of the second substrate W2 relative to the reference substrate, the temperature of the second substrate W2 relative to the reference substrate, and the warping of the second substrate W2 relative to the reference substrate.

[0222] Thus, the central part of the first substrate W1 and the central part of the second substrate W2 begin to bond. The first substrate W1 and the second substrate W2 are subjected to surface modification treatment. Therefore, van der Waals force (intermolecular force) is generated to bond the bonding surfaces of each substrate to each other. In addition, the first substrate W1 and the second substrate W2 are subjected to hydrophilization treatment. Therefore, the hydrophilic groups on the bonding surfaces of each substrate undergo hydrogen bonding, so that the bonding surfaces of each substrate are firmly bonded to each other.

[0223] Next, the control device 70 stops the suction of the second suction unit 113. As a result, the first substrate W1 falls onto the second substrate W2 from the center toward the outer periphery, and the first substrate W1 and the second substrate W2 are bonded to form a superimposed substrate T.

[0224] Then, the control device 70 stops the electro-pneumatic regulator 221 , switches the air intake and exhaust pipe 210 d to be connected to the vacuum pump 220 , sets the upper surface of the holding portion 211 to be horizontal, and then stops the suction portion 212 .

[0225] <Effect>

[0226] The bonding device 41 includes a holding portion 111 (an example of a first holding portion) that holds a first substrate W1 (an example of a substrate) to be bonded, and a deformation portion 114 (an example of a first deformation portion) that causes a central portion of the first substrate W1 held by the holding portion 111 to protrude relative to an outer peripheral portion of the first substrate W1. The bonding device 41 includes a control portion 70a that adjusts the amount of protrusion of the first substrate W1 by the deformation portion 114 for each first substrate W1 based on at least one of the thickness of the first substrate W1, the temperature of the first substrate W1, and the warping of the first substrate W1 when not held by the holding portion 111.

[0227] Thus, the bonding apparatus 41 can suppress the occurrence of scaling errors in the first substrate W1 , thereby improving the bonding accuracy of the superimposed substrates T.

[0228] In addition, the bonding device 41 includes a holding portion 211 (an example of a second holding portion) that holds a second substrate W2 (an example of a substrate) to be bonded, and a deformation portion 213 (an example of a second deformation portion) that causes a central portion of the second substrate W2 held by the holding portion 211 to protrude relative to an outer peripheral portion of the second substrate W2. The bonding device 41 includes a control portion 70a that adjusts the protrusion amount of the second substrate W2 by the deformation portion 213 for each second substrate W2 based on at least one of the thickness of the second substrate W2, the temperature of the second substrate W2, and the warping of the second substrate W2 when not held by the holding portion 111.

[0229] Thus, the bonding apparatus 41 can suppress the occurrence of scaling errors of the second substrate W2 , thereby improving the bonding accuracy of the superimposed substrates T.

[0230] In addition, the control unit 70a of the bonding device 41 adjusts the protrusion amount for each first substrate W1 based on at least one of the thickness of the first substrate W1 relative to the reference substrate, the temperature of the first substrate W1 relative to the reference substrate, and the warping of the first substrate W1 relative to the reference substrate. In addition, the control unit 70a of the bonding device 41 adjusts the protrusion amount for each second substrate W2 based on at least one of the thickness of the second substrate W2 relative to the reference substrate, the temperature of the second substrate W2 relative to the reference substrate, and the warping of the second substrate W2 relative to the reference substrate.

[0231] Thus, the bonding device 41 can suppress the scaling error of the first substrate W1 relative to the reference substrate. In addition, the bonding device 41 can suppress the scaling error of the second substrate W2 relative to the reference substrate. Therefore, the bonding device 41 can make the bonding accuracy of other overlapping substrates T consistent with the bonding accuracy of the overlapping substrate T serving as the reference. That is, the bonding device 41 can improve the bonding accuracy of the overlapping substrate T.

[0232] In addition, for example, the holding portion 211 of the bonding device 41 holds the second substrate W2 by adsorbing the non-bonding surface of the second substrate W2. In addition, when the second substrate W2 is warped in a state where the bonding surface of the peripheral portion protrudes more than the bonding surface of the central portion when not held by the holding portion 211, the control portion 70a of the bonding device 41 adjusts the protrusion amount for each second substrate W2 based on at least one of the thickness of the second substrate W2 and the temperature of the second substrate W2.

[0233] Thus, the bonding device 41 can adjust the protrusion of the second substrate W2, for example, according to the direction of the warping of the second substrate W2. Therefore, the bonding device 41 can adjust the protrusion of the second substrate W2, for example, according to whether a scaling error caused by the warping of the second substrate W2 occurs. Therefore, the bonding device 41 can improve the bonding accuracy of the overlapping substrates T.

[0234] <Modification>

[0235] The bonding device 41 according to the modification can apply the same structure as the second suction cup part 203 to the first suction cup part 103. That is, the bonding device 41 according to the modification can include the first suction cup part 103 having the structure of the holding part 211, the suction part 212, and the deformation part 213 of the second suction cup part 203.

[0236] In addition, the bonding device 41 involved in the modified example can adsorb and hold the first substrate W1 on the first suction cup part 103, make the central part of the first substrate W1 protrude downward according to the thickness and warping of the first substrate W1, and then correct the protrusion amount of the first substrate W1 according to the temperature of the first substrate W1. That is, the bonding device 41 involved in the modified example can adjust the protrusion amount for each first substrate W1 based on the temperature of the first substrate W1 in the state where the central part of the first substrate W1 (an example of a substrate) is protruded by the deformation part 114. The same is true for the second substrate W2.

[0237] Thus, the bonding apparatus 41 according to the modification example can suppress the occurrence of scaling errors caused by the temperature of the first substrate W1, for example. Therefore, the bonding apparatus 41 according to the modification example can improve the bonding accuracy of the superimposed substrates T.

[0238] In addition, the bonding apparatus 41 according to the modified example may generate the superimposed substrate T in such a manner that one of the first substrate W1 and the second substrate W2 protrudes and the other does not protrude.

[0239] In addition, it should be considered that the embodiments disclosed this time are illustrative in all aspects and are not restrictive. In fact, the above-mentioned embodiments can be specifically implemented in various ways. In addition, the above-mentioned embodiments can be omitted, replaced, and changed in various ways without departing from the attached claims and their purport.

[0240] Description of Reference Numerals

[0241] 1: bonding system; 41: bonding device; 70: control device; 70a: control unit; 70b: storage unit; 80: transmission unit; 82a: displacement sensor; 82b: displacement sensor; 83: load sensor; 100: first holding mechanism; 102: first height measuring unit; 103: first suction cup unit; 111: holding unit (first holding unit); 112: first suction unit; 113: second suction unit; 114: deformation unit (first deformation unit); 126: temperature sensor; 200: second holding mechanism; 202: second height measuring unit; 203: second suction cup unit; 211: holding unit (second holding unit); 212: suction unit; 213: deformation unit (second deformation unit); 244: temperature sensor; W1: first substrate; W2: second substrate.

Claims

1. A bonding device comprising: a holding portion that holds substrates to be joined; a deformation portion that causes a central portion of the substrate held by the holding portion to protrude relative to an outer peripheral portion of the substrate; and A control unit calculates, for each of the substrates, a protrusion amount of the central portion of the substrate so that the extension amount of the bonding surface of the substrate is equal to the extension amount of the bonding surface of the reference substrate based on at least one of the thickness of the substrate relative to the reference substrate, the temperature of the substrate relative to the reference substrate, and the warping of the substrate relative to the reference substrate when not held by the holding unit, and controls the deformation unit to cause the substrate to protrude based on the calculated protrusion amount.

2. The joining device according to claim 1, characterized in that: The control unit adjusts the protrusion amount for each of the substrates based on the temperature of the substrate in a state where the center portion of the substrate is protruded by the deforming unit.

3. The joining device according to claim 1 or 2, characterized in that: The holding portion holds the substrate by adsorbing the non-bonding surface of the substrate. When the substrate is warped in a state where the bonding surface of the peripheral portion protrudes more than the bonding surface of the central portion when not held by the holding portion, the control portion adjusts the protrusion amount for each substrate based on at least one of the thickness of the substrate and the temperature of the substrate.

4. The joining device according to claim 1 or 2, characterized in that: The holding portion comprises: a first holding portion that holds a first substrate; and a second holding portion that holds a second substrate to be joined to the first substrate, The deformation portion comprises: a first deforming portion that causes a central portion of the first substrate held by the first holding portion to protrude relative to an outer peripheral portion of the first substrate; as well as a second deforming portion that causes a central portion of the second substrate held by the second holding portion to protrude relative to an outer peripheral portion of the second substrate, The control unit adjusts a protrusion amount of the first substrate by the first deforming unit for each of the first substrates, and adjusts a protrusion amount of the second substrate by the second deforming unit for each of the second substrates.

5. A bonding method comprising the following steps: holding substrates to be joined; Using the deformation portion, the central portion of the held substrate protrudes relative to the outer peripheral portion of the substrate; as well as Based on at least one of the thickness of the substrate relative to a reference substrate, the temperature of the substrate relative to the reference substrate, and the warping of the substrate relative to the reference substrate in an unmaintained state, the protrusion amount of the central portion of the substrate that makes the extension amount of the bonding surface of the substrate equal to the extension amount of the bonding surface of the reference substrate is calculated for each of the substrates, and the deformation portion is controlled based on the calculated protrusion amount to make the substrate protrude.

Images