JP7495151B2 - Alignment apparatus and alignment method - Google Patents

Description

The present invention relates to an alignment device and an alignment method.

An alignment device has been proposed that aligns two objects to be joined together, and includes a stage and head that hold the objects, a table member that supports the stage, a number of support members that slidably support the table member, and a pressure applying unit that moves the stage in a direction parallel to a horizontal plane by changing the contact position of each pair of a number of pressure applying units and elastic support units that sandwich the stage in the clamping direction corresponding to each pair (see, for example, Patent Document 1).

JP 2011-119293 A

However, in the alignment device described in Patent Document 1, due to sliding resistance between the support member that supports the table member and the table member, sliding resistance of the cylinder portion of the biasing unit, etc., the stage may not move even when a driving force is applied that moves it by a small distance. In this case, the table member may bend, the support members of the bearings provided in the pressing force applying unit and the elastic support unit may bend, or the spherical rolling elements of the bearings may be crushed and deformed into an ellipsoid. If this happens, when time has passed since the application of the driving force, the table member and the bearings may return to their bent or deformed state, causing the table member to move further and resulting in a positional deviation.

The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide an alignment device and an alignment method that can align objects with high positional accuracy.

In order to achieve the above object, an alignment apparatus according to the present invention comprises:
1. An alignment apparatus for aligning a first object with respect to a second object, comprising:
A first object holder that holds the first object;
A second object holder that holds the second object ;
a linear actuator for adjusting a position of the first object holder in a first direction;
a distance measuring unit that is disposed around the first object holder and measures a distance between the first object holder and the distance measuring unit;
and a control unit that controls the linear actuator so that, after positioning of the first object relative to the second object is provisionally completed, when the position of the first object holding unit changes due to a change in position of the first object relative to the second object and the distance between the distance measurement unit and the first object holding unit changes, the distance between the distance measurement unit and the first object holding unit measured by the distance measurement unit becomes equal to the distance between the distance measurement unit and the first object holding unit measured by the distance measurement unit at the time of provisional completion of the positioning.

An alignment method according to another aspect of the present invention comprises:
1. A method for aligning a first object with a second object, comprising:
positioning the first object relative to the second object;
After the positioning is provisionally completed, a distance measurement unit disposed around a first object holder that holds the first object measures a distance between the distance measurement unit and the first object holder at the time of provisional completion of the positioning;
The method includes a step of: after the positioning of the first object relative to the second object is provisionally completed, if the position of the first object holding part changes, causing the position of the first object relative to the second object to change and the distance between the distance measurement part and the first object holding part to change, moving the first object holding part so that the distance between the distance measurement part and the first object holding part measured by the distance measurement part becomes equal to the distance between the distance measurement part and the first object holding part measured by the distance measurement part at the time of provisional completion of the positioning.

According to the present invention, after the positioning of the first object relative to the second object is provisionally completed, the control unit controls the linear actuator so that the distance between the distance measurement unit and the first object holding unit measured by the distance measurement unit at the time of completion of positioning is maintained constant. As a result, even if the first object moves further relative to the second object due to distortion of the first object holding unit, sliding resistance of the biasing unit, etc. after the positioning of the first object relative to the second object is provisionally completed, the first object can be aligned with high positional accuracy relative to the second object.

1 is a schematic configuration diagram of a joining device according to an embodiment of the present invention. FIG. 2 is a schematic perspective view showing the vicinity of a stage and a head in the embodiment. 2 is a schematic side view of the stage, head and the surrounding area according to the embodiment. FIG. FIG. 2A is a plan view of the periphery of a stage according to the embodiment, and FIG. 2B is a diagram showing a bearing according to the embodiment. 2 is a schematic side view of the periphery of a stage according to the embodiment. FIG. FIG. 2A is a plan view showing how the stage according to the embodiment moves in the +X direction, and FIG. 2B is a plan view showing how the stage according to the embodiment moves in the -Y direction. 11 is a plan view showing a state in which a stage in the embodiment rotates. FIG. FIG. 2A is a diagram showing two alignment marks provided on one of the two substrates to be joined, and FIG. 2B is a diagram showing two alignment marks provided on the other of the two substrates to be joined. 1A is a schematic diagram showing a captured image of alignment marks, and FIG. 1B is a schematic diagram showing a state in which the alignment marks are misaligned with each other. FIG. 1A is a schematic diagram showing how a table member is moved in one direction by a piezoelectric actuator according to an embodiment, and FIG. 1B is a schematic diagram showing how the table member is moved in another direction different from that of FIG. 4 is a flowchart showing the flow of a joining method executed by the joining device according to the embodiment. 1A is a schematic side view showing a state in which substrates are held by a stage and a head, and FIG. 1B is a schematic side view showing a state in which the substrates are in contact with each other, illustrating a bonding device according to an embodiment. 1 is a schematic side view showing how the bonding device bonds substrates together in an embodiment. 5A to 5C are explanatory diagrams illustrating the operation of the joining device according to the embodiment. FIG. 1A is a diagram showing a portion where sliding resistance occurs in the joining device according to Comparative Example 1, and FIG. 1B is a diagram showing how the bearing according to Comparative Example 1 bends. FIG. 11 is a schematic side view of the periphery of a stage of a bonding apparatus according to Comparative Example 2. FIG. 13 is a plan view of the periphery of a stage according to a modified example. 10 is a flowchart showing a flow of a joining method executed by a joining device according to a modified example. 2 is a schematic side view of the stage, head and the surrounding area according to the embodiment. FIG.

The bonding apparatus according to the embodiment of the present invention will be described below with reference to the drawings. The bonding apparatus according to the present embodiment bonds substrates W1 and W2 together by bringing the bonding surfaces of the activated substrates into contact with each other. As shown in FIG. 1, the bonding apparatus 1 according to the present embodiment includes a chamber 120, a stage 401, a head 402, a stage driving unit 403, a head driving unit 404, substrate heating units 481 and 482, and an imaging unit 500. Examples of the substrates W1 and W2 include Si substrates, glass substrates, and sapphire substrates. The bonding apparatus 1 also includes a distance measuring unit 490 that measures the distance between the stage 401 and the head 402, and distance measuring units 521 and 524 that are arranged around the stage 401. In the following description, the ±Z direction in FIG. 1 is appropriately taken as the up-down direction, and the XY direction is taken as the horizontal direction.

The chamber 120 maintains the area in which the substrates W1 and W2 are placed at a vacuum level equal to or higher than a preset reference vacuum level. The chamber 120 is connected to the vacuum pump 121a via an exhaust pipe 121b and an exhaust valve 121c. When the exhaust valve 121c is opened and the vacuum pump 121a is operated, the gas in the chamber 120 is exhausted to the outside of the chamber 120 through the exhaust pipe 121b, and the inside of the chamber 120 is maintained at a reduced pressure. In addition, the air pressure (vacuum level) in the chamber 120 can be adjusted by adjusting the amount of exhaust by varying the opening and closing amount of the exhaust valve 121c. The air pressure in the chamber 120 can be set within a range of 1 Pa to 1000 Pa.

The head drive unit 404 has an elevation drive unit 4042 that raises and lowers the head 402 vertically upward or downward (see arrow AR1 in FIG. 1), an XY direction drive unit 4041 that moves the head 402 in the XY direction, and a rotation drive unit 4043 that rotates the head 402 in a rotation direction around the Z axis (see arrow AR2 in FIG. 1). The XY direction drive unit 4041 and the rotation drive unit 4043 constitute a holding unit drive unit that moves the head 402 in a direction perpendicular to the vertical direction (XY direction, rotation direction around the Z axis). The head drive unit 404 also has a piezo actuator 411 for adjusting the inclination of the head 402 relative to the stage 401, and a pressure sensor 412 for measuring the pressure applied to the head 402. The XY direction drive unit 4042 and the rotation drive unit 4043 move the head 402 relative to the stage 401 in the X direction, the Y direction, and in a rotational direction around the Z axis, thereby enabling alignment of the substrate W1 held on the stage 401 and the substrate W2 held on the head 402.

The lifting drive unit 4042 moves the head 402 vertically to bring the stage 401 and the head 402 closer to each other or move the head 402 away from the stage 401. When the lifting drive unit 4042 moves the head 402 vertically downward, the substrate W1 held on the stage 401 and the substrate W2 held on the head 402 come into contact with each other. When the lifting drive unit 4042 applies a driving force to the head 402 in a direction toward the stage 401 while the substrates W1 and W2 are in contact with each other, the substrate W2 is pressed against the substrate W1. The lifting drive unit 4042 is also provided with a pressure sensor 408 that measures the driving force applied by the lifting drive unit 4042 to the head 402 in a direction toward the stage 401. From the measured value of the pressure sensor 408, the pressure acting on the bonding surfaces of the substrates W1 and W2 when the substrate W2 is pressed against the substrate W1 by the lifting drive unit 4042 can be detected. The pressure sensor 408 is composed of, for example, a load cell.

As shown in FIG. 2, there are three piezo actuators 411 and three pressure sensors 412. The three piezo actuators 411 and three pressure sensors 412 are arranged between the head 402 and the XY direction drive unit 4041. The three piezo actuators 411 are attitude adjustment units fixed at three positions on the top surface of the head 402 that are not on the same line, and at three positions arranged at approximately equal intervals along the circumferential direction of the head 402 on the periphery of the top surface of the head 402, which is approximately circular in plan view. The three pressure sensors 412 connect the upper end of the piezo actuator 411 to the lower surface of the XY direction drive unit 4041. The three piezo actuators 411 can be expanded and contracted in the vertical direction separately. The three piezo actuators 411 expand and contract to finely adjust the inclination of the head 402 around the X axis and the Y axis and the vertical position of the head 402. If the head 402 is tilted with respect to the stage 401, one of the three piezo actuators 411 can be extended to finely adjust the attitude of the head 402, thereby making the bottom surface of the head 402 and the top surface of the stage 401 approximately parallel. In addition, the three pressure sensors 412 measure the pressure forces at three positions on the bottom surface of the head 402. Then, by driving each of the three piezo actuators 411 so that the pressure forces measured by the three pressure sensors 412 are equal, the substrates W1 and W2 can be brought into contact with each other while maintaining the bottom surface of the head 402 and the top surface of the stage 401 approximately parallel.

As shown in FIG. 1, the stage 401 and the head 402 are arranged in the chamber 120 so that they face each other in the vertical direction and the stage 401 is located vertically below the head 402. The stage 401 supports the substrate W1 on its upper surface, and the head 402 supports the substrate W2 on its lower surface. Here, the stage 401 supports the substrate W1 with its upper surface in surface contact with the entire substrate W1, and the head 402 supports the substrate W2 with its lower surface in surface contact with the entire substrate W2. The stage 401 and the head 402 are formed of a light-transmitting material such as glass having light-transmitting properties. The stage 401 and the head 402 are provided with an electrostatic chuck (not shown) that holds the substrates W1 and W2. The electrostatic chuck is formed of a transparent conductive film including a transparent conductive material such as ITO. The electrostatic chuck attracts and holds the substrates W1 and W2 when a voltage is applied by a chuck driving unit (not shown). As shown in FIG. 2, the stage 401 is fixed to the center of one side in the thickness direction of a rectangular plate-shaped table member 405. The table member 405 has a light-transmitting portion 405a in the center that transmits light emitted from the imaging unit 500 in the thickness direction.

The table member 405 is supported by three support members 4039 arranged on its bottom side. The three support members 4039 support the table member 405 at three points PT1, PT2, and PT3 on the bottom side of the table member 405 that are spaced apart from each other and are not aligned in the same line. The upper ends of the three support members 4039 have approximately hemispherical portions and are in point contact with the table member 405 at three points PT1, PT2, and PT3 on the bottom surface of the table member 405. This reduces the sliding resistance between the upper ends of the support members 4039 and the table member 405, allowing the table member 405 to slide smoothly. Each support member 4039 has a piezoelectric actuator (not shown) that expands and contracts in the Z-axis direction, and the piezoelectric actuators of the support members 4039 expand and contract in the Z-axis direction in sync to raise and lower the table member 405.

The bonding apparatus 1 also includes a support table 406 disposed vertically below the light-transmitting portion 405a of the table member 405, as shown in FIG. 3. As the three support members 4039 are lowered, the bottom surface of the table member 405 comes into surface contact with the upper surface of the support table 406, and the table member 405 is supported by the support table 406. The support table 406 is formed from a material having a sufficiently high rigidity to withstand the pressure applied when the substrates W1 and W2 are pressed. This makes it difficult for the table member 405 to bend, and the substrates W1 and W2 can be bonded together while maintaining the flatness of the substrate W1 held by the table member 405 and the stage 401 with high precision.

As shown in Fig. 4A, the stage driving unit 403 has three linear actuators 4031, 4032, and 4033, and three air cylinders 4034, 4035, and 4036. Here, the linear actuator 4031 and the air cylinder 4034 clamp the table member 405 in the Y-axis direction. The linear actuator 4032 and the air cylinder 4036 clamp the portion of the table member 405 on the +Y side of the center in the Y-axis direction in the X-axis direction, and the linear actuator 4033 and the air cylinder 4035 clamp the portion of the table member 405 on the -Y side of the center in the Y-axis direction in the X-axis direction. That is, there are three sets each consisting of three air cylinders 4034, 4035, 4036 and linear actuators 4031, 4032, 4033 arranged to face the three air cylinders 4034, 4035, 4036 via the table member 405 and the stage 401. The opposing directions of the air cylinders 4035, 4036 and the linear actuators 4033, 4032 in two of the three sets are the same in the X-axis direction, while the opposing direction of the remaining air cylinder 4034 and the linear actuator 4031 is the Y-axis direction, which intersect with the X-axis direction, which is the opposing direction of the two air cylinders 4035, 4036 and the linear actuators 4033, 4032. Further, the linear actuators 4031, 4032, 4033 and the air cylinders 4034, 4035, 4036 respectively have bearings 4031c, 4032c, 4033c, 4034c, 4035c, 4036c which come into contact with the peripheral surface of the table member 405. As shown in FIG. 4B, the bearings 4031c, 4032c, 4033c, 4034c, 4035c, 4036c each include an outer ring 4031c1, 4032c1, 4033c1, 4034c1, 4035c1, 4036c1 and an inner ring 4031c3, 4032c3, 4033c3, 4033c3, 4034c1, 4035c1, 4036c1, respectively. and rolling elements 4031c2, 4032c2, 4033c2, 4034c2, 4035c2, 4036c2 such as balls or rollers interposed between outer rings 4031c1, 4032c1, 4033c1, 4034c1, 4035c1, 4036c1 and inner rings 4031c3, 4032c3, 4033c3, 4034c3, 4035c3, 4036c3. In addition, the inner rings 4031c3, 4032c3, 4033c3, 4034c3, 4035c3, and 4036c3 are fixed to piezoelectric actuators 4031d, 4032d, 4033d, 4034d, 4035d, and 4036d, described below, via support members 4031c4, 4032c4, 4033c4, 4034c4, 4035c4, and 4036c4. The bearings 4031c, 4032c, 4033c, 4034c, 4035c, and 4036c are arranged with the rotation axes of the outer rings 4031c1, 4032c1, 4033c1, 4034c1, 4035c1, and 4036c1 aligned along the Z-axis direction, and each outer ring 4031c1, 4032c1, 4033c1, 4034c1, 4035c1, and 4036c1 abuts against the peripheral surface of the table member 405. When these bearings 4031c, 4032c, 4033c, 4034c, 4035c, and 4036c are pressed against the peripheral surface of the table member 405, deflection occurs in the outer rings 4031c1, 4032c1, 4033c1, 4034c1, 4035c1, and 4036c1.

In addition, six distance measuring units 521, 522, 523, 524, 525, 526 that measure the distance between the peripheral surface of the table member 405 are disposed adjacent to the three linear actuators 4031, 4032, 4033 and the three air cylinders 4034, 4035, 4036. Here, one distance measuring unit 521, 522, 523 is provided for each of the linear actuators 4031, 4032, 4033, respectively.

The linear actuators 4031, 4032, and 4033 have transmission members 4031b, 4032b, and 4033b, transmission member drive units 4031a, 4032a, and 4033a that drive the transmission members 4031b, 4032b, and 4033b, and bearings 4031c, 4032c, and 4033c provided on the tip side of the transmission members 4031b, 4032b, and 4033b. The transmission members 4031b, 4032b, and 4033b are long, bottomed, cylindrical first transmission members for transmitting a pressing force to the table member 405, and have piezoelectric actuators 4031d, 4032d, and 4033d (described later) fixed to the end on the bottom wall side in the longitudinal direction, and nuts 4031h, 4032h, and 4033h provided on the end opposite the bottom wall side in the longitudinal direction. The linear actuators 4031, 4032, 4033 have linear guides 4031f, 4032f, 4033f that abut against the transmission members 4031b, 4032b, 4033b via rolling elements 4031g, 4032g, 4033g and support the transmission members 4031b, 4032b, 4033b slidably in one direction, and feed screws 4031e, 4032e, 4033e such as ball screws or sliding screws. The feed screws 4031e, 4032e, 4033e are screwed into nut portions 4031h, 4032h, 4033h provided on the transmission members 4031b, 4032b, 4033b. The transmission member driving portions 4031a, 4032a, 4033a rotate the feed screws 4031e, 4032e, 4033e around their central axes along the longitudinal direction, thereby moving the transmission members 4031b, 4032b, 4033b. Furthermore, the linear actuators 4031, 4032, 4033 have linear encoders 531, 532, 533 that detect the amount of movement of the transmission members 4031b, 4032b, 4033b, and piezo actuators 4031d, 4032d, 4033d that are interposed between the transmission members 4031b, 4032b, 4033b and the bearings 4031c, 4032c, 4033c and extend or contract the entire length of the transmission members 4031b, 4032b, 4033b in the direction along the movement direction of the transmission members 4031b, 4032b, 4033b.

The transmission member drive units 4031a, 4032a, and 4033a have servo motors (not shown) and rotate the feed screws 4031e, 4032e, and 4033e to protrude and retract the transmission members 4031b, 4032b, and 4033b as shown by the arrows AR31, AR32, and AR33 in FIG. 4A. The transmission member drive units 4031a, 4032a, and 4033a are fixed to preset positions on the peripheral wall of the chamber 120. The transmission member drive units 4031a, 4032a, and 4033a can move the transmission members 4031b, 4032b, and 4033b in a movable range larger than the extension and contraction range of the piezo actuators 4031d, 4032d, and 4033d, so that the table member 405 can be positioned in a relatively large range. The outer rings of bearings 4031c, 4032c, and 4033c rotate while in contact with the peripheral surface of table member 405.

5, the linear encoders 531, 532, and 533 are fixed in position relative to the transmission member drive units 4031a, 4032a, and 4033a, and have a main scale (not shown) provided on the outer wall of the transmission members 4031b, 4032b, and 4033b along the longitudinal direction of the transmission members 4031b, 4032b, and 4033b, and a detection head that detects the position on the main scale. The linear encoders 531, 532, and 533 can be of an electromagnetic detector type, an optical detector type, or the like.

The piezoelectric actuators 4031d, 4032d, and 4033d expand and contract in the longitudinal direction of the transmission members 4031b, 4032b, and 4033b. By driving the piezoelectric actuators 4031d, 4032d, and 4033d, the contact positions of the transmission members 4031b, 4032b, and 4033b with the table member 405 can be finely adjusted. The linear actuators 4031, 4032, and 4033 apply a pressing force to the table member 405 by pressing the tips of the transmission members 4031b, 4032b, and 4033b against the table member 405.

The air cylinders 4034, 4035, and 4036 are biasing parts having transmission members 4034b, 4035b, and 4036b, cylinder bodies 4034a, 4035a, and 4036a that hold pistons 4034e, 4035e, and 4036e to which the transmission members 4034b, 4035b, and 4036b are fixed, and bearings 4034c, 4035c, and 4036c are provided on the tip side of the transmission members 4034b, 4035b, and 4036b. The transmission members 4034b, 4035b, and 4036b are long second transmission members for transmitting a pressing force to the table member 405. The bearings 4034c, 4035c, and 4036c are arranged in a position where the rotation axis of the outer ring is along the Z-axis direction, and each outer ring abuts against the peripheral surface of the table member 405. In addition, the air cylinders 4034, 4035, 4036 have linear guides 4034f, 4035f, 4036f that abut against the transmission members 4034b, 4035b, 4036b via rolling elements 4034g, 4035g, 4036g and support the transmission members 4034b, 4035b, 4036b so that they can slide freely along one direction, and piezoelectric actuators 4034d, 4035d, 4036d that are interposed between the transmission members 4034b, 4035b, 4036b and the bearings 4034c, 4035c, 4036c and expand/contract the length of the transmission members 4034b, 4035b, 4036b in the direction along the movement direction. The cylinder bodies 4034a, 4035a, 4036a movably hold the transmission members 4034b, 4035b, 4036b and the pistons 4034e, 4035e, 4036e as shown by the arrows AR34, AR35, AR36, and when the pistons 4034e, 4035e, 4036e are pressed in, they urge the pistons 4034e, 4035e, 4036e in the direction in which they protrude. The cylinders 4034a, 4035a, 4036a are fixed to the peripheral wall of the chamber 120 at positions facing the transmission member drive parts 4031a, 4032a, 4033a, respectively. The outer rings of the bearings 4034c, 4035c, 4036c rotate while contacting the peripheral surface of the table member 405. When either one of the piezo actuators 4031d, 4034d expands, the other operates to contract by the same amount. Also, when either one of the piezo actuators 4032d, 4035d expands, the other operates to contract by the same amount. Furthermore, when either one of the piezo actuators 4033d, 4036d expands, the other operates to contract by the same amount.

The distance measuring units 521, 522, 523, 524, 525, and 526 are laser displacement sensors that have a light-emitting element such as a semiconductor laser and a linear image sensor, and are arranged so that the light emitted from the light-emitting element and reflected by the peripheral surface of the table member 405 is received by the linear image sensor, and perform distance measurement using a method that utilizes the principle of triangulation. The distance measuring unit 521 is arranged adjacent to the linear actuator 4031 in the X-axis direction, and measures the distance L11 between the distance measuring unit 521 and the peripheral surface of the table member 405 on the +Y direction side. The distance measuring unit 522 is arranged adjacent to the linear actuator 4032 in the Y-axis direction, and measures the distance L12 between the distance measuring unit 522 and the peripheral surface of the table member 405 on the -X direction side. The distance measuring unit 522 is arranged adjacent to the linear actuator 4033 in the Y-axis direction, and measures the distance L13 between the distance measuring unit 523 and the peripheral surface of the table member 405 on the -X direction side. The distance measurement unit 524 is disposed adjacent to the air cylinder 4034 in the X-axis direction, and measures the distance L14 between the distance measurement unit 524 and the peripheral surface of the table member 405 on the -Y direction side. The distance measurement unit 525 is disposed adjacent to the air cylinder 4035 in the Y-axis direction, and measures the distance L15 between the distance measurement unit 525 and the peripheral surface of the table member 405 on the +X direction side. The distance measurement unit 526 is disposed adjacent to the air cylinder 4036 in the Y-axis direction, and measures the distance L16 between the distance measurement unit 526 and the peripheral surface of the table member 405 on the +X direction side. The distance measurement units 521, 522, 523, 524, 525, and 526 generate measurement signals reflecting the measured distances L11, L12, L13, L14, L15, and L16, respectively, and output them to the control unit 9.

6(A), when the linear actuators 4032, 4033 move the transmission members 4032b, 4033b in the direction indicated by the arrow AR321 with the bearings 4032c, 4033c respectively abutting against the peripheral surface on the -X direction side of the table member 405, the table member 405 moves in the +X direction accordingly. At this time, the air cylinders 4035, 4036, with the bearings 4035c, 4036c respectively abutting against the peripheral surface on the +X direction side of the table member 405, have the transmission members 4035b, 4036b pressed in the direction indicated by the arrow AR322. The position of the table member 405 in the X-axis direction is determined by balancing the pressing force of the linear actuators 4032, 4033 pressing the table member 405 in the +X direction via the bearings 4032c, 4033c and the biasing force of the air cylinders 4035, 4036 biasing the table member 405 in the -X direction via the bearings 4035c, 4036c. On the other hand, when the linear actuators 4032, 4033 move the transmission members 4032b, 4033b in the direction opposite to the direction indicated by the arrow AR321 with the bearings 4032c, 4033c respectively abutting against the peripheral surface of the -X direction side of the table member 405, the table member 405 moves in the -X direction accordingly. At this time, the air cylinders 4035 and 4036 maintain the bearings 4035c and 4036c in contact with the peripheral surface of the table member 405 on the +X side due to the biasing force that biases the transmission members 4035b and 4036b in the -X direction. Also, when the table member 405 moves along the X-axis direction, the bearing 4031c of the linear actuator 4031 and the bearing 4034c of the air cylinder 4034 rotate in contact with the peripheral surfaces on both sides of the table member 405 in the Y-axis direction. This reduces the contact resistance when moving the table member 405 in the X-axis direction, allowing the table member 405 to move smoothly along the X-axis direction.

6B, when the linear actuator 4031 moves the transmission member 4031b in the direction indicated by the arrow AR323 with the bearing 4031c in contact with the peripheral surface of the table member 405 on the +Y direction side, the table member 405 moves in the -X direction accordingly. At this time, the air cylinder 4034 pushes the transmission member 4034b in the direction indicated by the arrow AR324 with the bearing 4034c in contact with the peripheral surface of the table member 405 on the -Y direction side. The position of the table member 405 in the Y axis direction is determined by the balance between the pressing force of the linear actuator 4031 pressing the table member 405 in the -Y direction via the bearing 4031c and the biasing force of the air cylinder 4034 biasing the table member 405 in the +X direction via the bearing 4034c. On the other hand, when the linear actuator 4031 moves the transmission member 4031b in the opposite direction to the direction indicated by the arrow AR323 with the bearing 4031c in contact with the circumferential surface on the +Y direction side of the table member 405, the table member 405 moves in the +Y direction accordingly. At this time, the air cylinder 4034 maintains the state in which the bearing 4034c is in contact with the circumferential surface on the -Y direction side of the table member 405 due to the biasing force that biases the transmission member 4034b in the +Y direction side. Also, when the table member 405 moves along the Y axis direction, the bearings 4032c and 4033c of the linear actuators 4032 and 4033 and the bearings 4035c and 4036c of the air cylinders 4035 and 4036 rotate in a state in which they are in contact with the circumferential surfaces on both sides in the X axis direction of the table member 405. Therefore, the contact resistance when moving the table member 405 in the Y axis direction can be reduced, and the table member 405 can be moved smoothly along the Y axis direction.

7, the linear actuator 4032 moves the transmission member 4032b in the direction indicated by the arrow AR325 with the bearing 4032c in contact with the peripheral surface of the -X direction side of the table member 405, and the linear actuator 4033 moves the transmission member 4033b in the direction indicated by the arrow AR326 with the bearing 4033c in contact with the peripheral surface of the -X direction side of the table member 405. In this case, the air cylinder 4036 pushes the transmission member 4036b in the direction indicated by the arrow AR327 with the bearing 4036c in contact with the peripheral surface of the +X direction side of the table member 405. In addition, the air cylinder 4035 maintains the state in which the bearing 4035c is in contact with the peripheral surface of the +X direction side of the table member 405 due to the biasing force that biases the transmission member 4035b in the -X direction. In this way, the linear actuators 4032 and 4033 move the pistons 4032b and 4033b in different directions, respectively, to rotate the table member 405 and the stage 401, as shown by the arrow AR329.

Returning to FIG. 1, the distance measurement unit 490 is, for example, a laser distance meter, and measures the distance between the stage 401 and the head 402 without contacting the stage 401 and the head 402. The distance measurement unit 490 measures the distance between the stage 401 and the head 402 from the difference between the reflected light on the upper surface of the stage 401 and the reflected light on the lower surface of the head 402 when a laser beam is irradiated from above the head 402 made of a light-transmitting material toward the stage 401. As shown in FIG. 2, the distance measurement unit 490 measures the distance between three sites P11, P12, and P13 on the upper surface of the stage 401 and three sites P21, P22, and P23 on the lower surface of the head 402 that face the sites P11, P12, and P13 in the Z direction. As described above, since the head 402 or the stage 401 is made of a light-transmitting material, the laser can be transmitted through the head 402 or the stage 401 to measure the distance. This has the advantage that the distance measurement unit 490 can be configured to be positioned on the side of the head 402 and stage 401 opposite the substrates W1 and W2.

As shown in FIG. 3, the imaging unit 500 has imaging sections 501 and 502 and mirrors 504 and 505. The imaging sections 501 and 502 are arranged on the side of the stage 401 opposite the side that holds the substrate W1. The imaging sections 501 and 502 each have an imaging element (not shown) and a coaxial illumination system (not shown). As a light source for the coaxial illumination system, a light source that emits light (e.g., infrared light) that transmits through the substrates W1 and W2, the stage 401, and the light-transmitting section 405a of the table member 405 is used.

8A and 8B, for example, two alignment marks (first alignment marks) MK1a and MK1b are provided on the substrate W1, and two alignment marks (second alignment marks) MK2a and MK2b are provided on the substrate W2. The bonding apparatus 1 performs an alignment operation (alignment operation) of both substrates W1 and W2 while recognizing the positions of the alignment marks MK1a, MK1b, MK2a, and MK2b provided on the substrates W1 and W2 imaged by the imaging unit. More specifically, the bonding apparatus 1 first performs a rough alignment operation (rough alignment operation) of the substrates W1 and W2 while recognizing the alignment marks MK1a, MK1b, MK2a, and MK2b provided on the substrates W1 and W2 imaged by the imaging unit 500, to face the two substrates W1 and W2. The bonding device 1 then performs a more precise alignment operation (fine alignment operation) while simultaneously recognizing the alignment marks MK1a, MK2a, MK1b, and MK2b on the two substrates W1 and W2 captured by the imaging unit 500.

3, the light emitted from the light source of the coaxial illumination system of the imaging unit 501 is reflected by the mirror 504 and travels upward, passing through the support base 406, the light-transmitting portion 405a of the table member 405, and part or all of the substrates W1 and W2. The light that has traveled through part or all of the substrates W1 and W2 is reflected by the alignment marks MK1a and MK2a of the substrates W1 and W2, travels downward, passes through the light-transmitting portion 405a of the table member 405 and the support base 406, is reflected by the mirror 504, and enters the imaging element of the imaging unit 501. The light emitted from the light source of the coaxial illumination system of the imaging unit 502 is reflected by the mirror 505 and travels upward, passing through the support base 406, the light-transmitting portion 405a of the table member 405, and part or all of the substrates W1 and W2. The light that has passed through part or all of the substrates W1 and W2 is reflected by the alignment marks MK1a and MK2a of the substrates W1 and W2, travels downward, passes through the light-transmitting portion 405a of the table member 405 and the support base 406, is reflected by the mirror 505, and enters the image sensor of the image sensor of the image sensor 502. The image sensors 501 and 502 of the image sensor 500 use the light that enters the image sensor to simultaneously capture an image GAa including the alignment marks MK1a and MK2a of the two substrates W1 and W2, and an image GAb including the alignment marks MK1b and MK2b of the two substrates W1 and W2 within one field of view, as shown in FIGS. 9A and 9B. The image sensor 501 captures the image GAa and the image sensor 502 captures the image GAb simultaneously.

Returning to FIG. 1, the substrate heating units 481 and 482 are, for example, electric heaters, and are provided on the stage 401 and head 402, respectively. The substrate heating units 481 and 482 heat the substrates W1 and W2 held on the stage 401 and head 402 by transferring heat to the substrates W1 and W2. The temperatures of the substrates W1 and W2 and their bonding surfaces can be adjusted by adjusting the amount of heat generated by the substrate heating units 481 and 482. The substrate heating units 481 and 482 are also connected to a heating unit drive unit (not shown), which supplies current to the substrate heating units 481 and 482 based on a control signal input from the control unit 9 shown in FIG. 1, thereby causing the substrate heating units 481 and 482 to generate heat.

The control unit 9 is a control system having, for example, a personal computer, and has a CPU (Central Processing Unit) and a memory. The memory stores a program executed by the CPU. The memory also stores preset positional deviation thresholds Δxth, Δyth, and Δθth for the relative calculated positional deviations Δx, Δy, and Δθ of the substrates W1 and W2 described later. The control unit 9 converts the measurement signals input from the pressure sensor 412, the pressure sensor 408, and the distance measurement units 490, 521, 522, 523, 524, 525, and 526 into measurement information and acquires it. The control unit 9 also converts the captured image signals input from the imaging units 501 and 502 into captured image information and acquires it. Furthermore, the control unit 9 controls the operations of the holding unit drive unit, the piezo actuator 411, the heating unit drive unit, the stage drive unit 403, and the head drive unit 404 by outputting control signals to each of them.

As shown in FIG. 9B, the control unit 9 calculates the positional deviation amounts Δxa and Δya between a pair of alignment marks MK1a and MK2a provided on the substrates W1 and W2 based on the captured image GAa acquired from the imaging unit 501. Note that FIG. 9B shows a state in which a pair of alignment marks MK1a and MK2a are misaligned with each other. Similarly, the control unit 9 calculates the positional deviation amounts Δxb and Δyb between another pair of alignment marks MK1b and MK2b provided on the substrates W1 and W2 based on the captured image GAb acquired from the imaging unit 502. Then, the control unit 9 calculates the relative positional deviation amounts Δx, Δy, and Δθ of the two substrates W1 and W2 in the X direction, Y direction, and rotational direction around the Z axis based on the positional deviation amounts Δxa, Δya, Δxb, and Δyb of these two pairs of alignment marks and the geometric relationship between the two pairs of marks. Then, the control unit 9 calculates the correction movement amount of the stage 401 so that the calculated positional deviation amounts Δx, Δy, Δθ are reduced, and controls the transmission member driving units 4031a, 4032a, 4033a to drive the transmission members 4031b, 4032b, 4033b so that the movement amounts of the transmission members 4031b, 4032b, 4033b detected by the linear encoders 531, 532, 533 become the calculated correction movement amounts, thereby moving the stage 401 in the X direction and Y direction, and rotating it around the Z axis. As a result, the relative positional deviation amounts Δx, Δy, Δθ of the two substrates W1, W2 are reduced. In this way, the bonding apparatus 1 performs an alignment operation to correct the positional deviation amounts Δx, Δy, Δθ of the two substrates W1, W2 in the horizontal direction. Also, as a result of the alignment operation, it is assumed that the horizontal positional deviations Δx, Δy, Δθ of the two substrates W1, W2 become equal to or less than the preset positional deviation thresholds, and the positioning of the two substrates W1, W2 is provisionally completed. In this case, the control unit 9 controls the transmission member driving units 4031a, 4032a, 4033a and the piezo actuators 4031d, 4032d, 4033d, 4034d, 4035d, 4036d so that the distances to the table member 405 measured by the distance measuring units 521, 522, 523, 524, 525, 526 at the time of provisional completion of the positioning are maintained constant. Here, the control unit 9 first controls the piezo actuators 4031d, 4032d, 4033d, 4034d, 4035d, and 4036d to expand and contract in conjunction with each other so that the distances between the distance measuring units 521, 522, 523, 524, 525, and 526 and the table member 405 measured by the distance measuring units 521, 522, 523, 524, 525, and 526 at the time of provisional completion of positioning are maintained constant. Here, the control unit 9 controls the piezo actuators 4031d (4032d and 4033d) to expand by a length Δp1 as shown in FIG. 10A, for example, and controls the piezo actuators 4034d (4035d and 4036d) opposed to the piezo actuator 4031d (4032d and 4033d) via the table member 405 to contract by a length Δp1. As a result, the table member 405 moves in the direction shown by the arrow AR4051. On the other hand, when the control unit 9 contracts the piezo actuator 4031d (4032d, 4033d) by a length Δp2, for example, as shown in Fig. 10B, the control unit 9 controls the piezo actuator 4034d (4035d, 4036d) opposed thereto via the table member 405 to be expanded by a length Δp2. This causes the table member 405 to move in the direction indicated by the arrow AR4052. In this way, when the table member 405 is moved by the piezo actuators 4031d, 4032d, 4033d, 4034d, 4035d, 4036d, no sliding resistance is generated, which is preferable from the viewpoint of reducing the influence of the sliding resistance. In addition, the control unit 9 may control the piezo actuators 4031d, 4032d, 4033d, 4034d, 4035d, and 4036d to extend and retract in a coordinated manner even when the table member 405 is repeatedly moved slightly during alignment of the substrates W1 and W2. If the distance between the distance measuring units 521, 522, 523, 524, 525, and 526 and the table member 405 cannot be maintained constant by simply extending and retracting the piezo actuators 4031d, 4032d, 4033d, 4034d, 4035d, and 4036d in a coordinated manner, the control unit 9 controls the transmission member driving units 4031a, 4032a, and 4033a so that the distance between the distance measuring units 521, 522, 523, 524, 525, and 526 and the table member 405 is maintained constant.

The control unit 9 further controls the distance measurement unit 490 to measure the distances between the three locations P11, P12, and P13 on the stage 401 and the locations P21, P22, and P23 on the head 402 that correspond to the locations P11, P12, and P13, respectively. Then, based on the distances measured by the distance measurement unit 490, the control unit 9 controls the three piezo actuators 411 described above so that the substrate W2 held by the head 402 is parallel to the substrate W1 held by the stage 401.

Next, the bonding method performed by the bonding apparatus 1 according to this embodiment will be described with reference to Figs. 11 to 13. In Fig. 11, the bonding apparatus 1 is assumed to have completed measurement of the distance between the upper surface of the stage 401 and the lower surface of the head 402 by the distance measurement unit 490 while the substrates W1 and W2 are not being held by the stage 401 and the head 402, and to have stored the measurement results in memory. Furthermore, it is assumed that the measurement results of the thicknesses of the substrates W1 and W2 have already been stored in memory.

11, the bonding apparatus 1 causes the stage 401 to hold only the peripheral portion of the substrate W1, and the head 402 to hold only the peripheral portion of the substrate W2 with the bonding surfaces of the substrates W1 and W2 facing each other (step S101). Here, the control unit 9 drives the electrostatic chuck disposed on the stage 401 to hold the substrate W1 on the stage 401, for example, with the substrate W1 placed on the stage 401. The control unit 9 also drives the electrostatic chuck disposed on the head 402 to hold the substrate W2 on the head 402, for example, with the head 402 in contact with the side of the substrate W2 opposite the bonding surface side disposed vertically below the head 402.

Next, the bonding apparatus 1 calculates the distance between the bonding surfaces of the substrates W1 and W2 based on the distance between the upper surface of the stage 401 and the lower surface of the head 402 when the substrates W1 and W2 are not held by the stage 401 and the head 402, and the thicknesses of the substrates W1 and W2. Then, based on the calculated distance, the bonding apparatus 1 moves the head 402 vertically downward to bring the substrates W1 and W2 closer to each other (step S102).

Next, the bonding apparatus 1 measures the positional deviation amount of the substrate W1 relative to the substrate W2 while the substrates W1 and W2 are spaced apart from each other (step S103). Here, the control unit 9 first captures the captured images GAa and GAb (see FIG. 9A) of the two substrates W1 and W2 in a non-contact state from the imaging units 501 and 502 of the imaging unit 500. Then, the control unit 9 calculates the positional deviation amounts Δx, Δy, and Δθ of the two substrates W1 and W2 in the X direction, Y direction, and rotational direction around the Z axis, respectively, based on the two captured images GAa and GAb. Specifically, the control unit 9 calculates the positional deviation amounts Δxa and Δya (see FIG. 9B) using a vector correlation method based on the captured image GAa obtained by simultaneously reading the alignment marks MK1a and MK2a spaced apart in the Z direction, for example. Similarly, the positional deviations Δxb and Δyb are calculated using the vector correlation method based on the captured image GAb obtained by simultaneously reading the alignment marks MK1b and MK2b spaced apart in the Z direction.Then, the control unit 9 calculates the positional deviations Δx, Δy, and Δθ in the horizontal direction of the two substrates W1 and W2 based on the positional deviations Δxa, Δya, Δxb, and Δyb.

Returning to FIG. 11, the bonding apparatus 1 then moves the substrate W2 relative to the substrate W1 so as to correct the calculated misalignment amounts Δx, Δy, and Δθ (step S104). Here, the bonding apparatus 1 moves the head 402 in the X direction, Y direction, and rotational direction around the Z axis so as to eliminate the misalignment amounts Δx, Δy, and Δθ while fixing the stage 401. In addition, at this time, the bonding apparatus 1 measures the distances between the three portions P11, P12, and P13 of the stage 401 and the portions P21, P22, and P23 corresponding to the portions P11, P12, and P13 of the head 402, respectively, and adjusts the attitude of the substrate W2 held by the head 402 with respect to the substrate W1 held by the stage 401 based on the measured distances. Here, the joining device 1 calculates the correction movement amount of the stage 401 based on the calculated positional deviation amounts Δx, Δy, and Δθ, and drives the transmission members 4031b, 4032b, and 4033b so that the movement amounts of the transmission members 4031b, 4032b, and 4033b detected by the linear encoders 531, 532, and 533 become the calculated correction movement amounts.

Next, the bonding apparatus 1 measures the amount of positional deviation of the substrate W2 relative to the substrate W1 while the substrates W1 and W2 are spaced apart from each other (step S105). Here, in the bonding apparatus 1, the alignment marks MK1a and MK2a and the alignment marks MK1b and MK2b are spaced apart by a distance that falls within the range of the depth of field of the imaging units 501 and 502, and the imaging units 501 and 502 are disposed at positions where they can image the pair of alignment marks MK1a and MK2a and the pair of alignment marks MK1b and MK2b, respectively. The bonding apparatus 1 controls the imaging units 501 and 502 so that the imaging units 501 and 502 simultaneously image the corresponding pair of alignment marks MK1a and MK2a and the corresponding pair of alignment marks MK1b and MK2b at the same timing in one image capture. As a result, each of the imaging units 501 and 502 simultaneously captures a pair of alignment marks MK1a, MK2a and a pair of alignment marks MK1b, MK2b, thereby reducing the effects of errors caused by differences in imaging timing when capturing images of the pair of alignment marks MK1a, MK2a (MK1b, MK2b) separately, as well as errors caused by vibrations of the imaging units 501 and 502. The bonding apparatus 1 then calculates the positional deviations Δx, Δy, and Δθ of the substrate W2 relative to the substrate W1 based on the captured images captured by the imaging units 501 and 502.

Next, the bonding apparatus 1 determines whether all of the measured positional deviations Δx, Δy, and Δθ of the substrate W2 relative to the substrate W1 are equal to or less than the preset positional deviation thresholds Δxth, Δyth, and Δθth (step S106). Here, it is assumed that the bonding apparatus 1 determines that any of the measured positional deviations Δx, Δy, and Δθ is greater than the positional deviation thresholds Δxth, Δyth, and Δθth (step S106: No). In this case, the bonding apparatus 1 calculates a correction movement amount for the substrate W2 relative to the substrate W1 to make all of the measured positional deviations Δx, Δy, and Δθ equal to or less than the positional deviation thresholds Δxth, Δyth, and Δθth (step S107). Here, the control unit 9 calculates a correction movement amount to move the substrate W2 by the measured positional deviations Δx, Δy, and Δθ in the opposite direction to the positional deviation direction. Next, the bonding apparatus 1 drives the transmission members 4031b, 4032b, and 4033b so that the movement amounts of the transmission members 4031b, 4032b, and 4033b detected by the linear encoders 531, 532, and 533 become the calculated correction movement amounts, thereby moving the substrate W2 relative to the substrate W1 (step S108). Here, the bonding apparatus 1 moves the head 402 in the X direction, the Y direction, and the rotation direction around the Z axis by the correction movement amount calculated in step S108, with the stage 401 fixed. In this way, the bonding apparatus 1 adjusts the relative position of the substrate W2 with respect to the substrate W1 so that the positional deviation amounts Δx, Δy, and Δθ become small, with the substrates W1 and W2 spaced apart from each other. Then, the bonding apparatus 1 executes the process of step S106 again.

On the other hand, it is assumed that the joining device 1 determines that all of the measured positional deviations Δx, Δy, and Δθ are equal to or less than the positional deviation thresholds Δxth, Δyth, and Δθth (step S106: Yes). In this case, the joining device 1 measures the distances L11, L12, L13, L14, L15, and L16 shown in FIG. 4A using the distance measuring units 521, 522, 523, 524, 525, and 526. The joining device 1 then converts the measurement signals reflecting the distances L11, L12, L13, L14, L15, and L16 input from the distance measuring units 521, 522, 523, 524, 525, and 526 into distance information indicating the distances L11, L12, L13, L14, L15, and L16, and stores the converted information in memory (step S109).

After that, the joining device 1 waits for a preset time (step S110) and again measures the distances L11, L12, L13, L14, L15, and L16 (see FIG. 4A) using the distance measuring units 521, 522, 523, 524, 525, and 526 (step S111). Next, the joining device 1 determines whether or not at least one of the measured distances L11, L12, L13, L14, L15, and L16 has changed by a preset distance threshold or more before and after step S111 (step S112). Here, it is assumed that the joining device 1 has determined that at least one of the distances L11, L12, L13, L14, L15, and L16 has changed by the aforementioned distance threshold or more (step S112: Yes). In this case, the bonding device 1 extends and retracts the piezo actuators 4031d, 4032d, 4033d, 4034d, 4035d, and 4036d of the linear actuators 4031, 4032, and 4033 and the air cylinders 4034, 4035, and 4036 adjacent to the distance measuring units 521, 522, 523, 524, 525, and 526 whose distances L11, L12, L13, L14, L15, and L16 have changed by more than the distance threshold value in conjunction with each other so as to cancel the changes in the distances L11, L12, L13, L14, L15, and L16 (step S113). Here, when one of the piezo actuators 4031d and 4034d expands, the other operates to contract by the same amount. In addition, when one of the piezo actuators 4032d, 4035d expands, the other operates to contract by the same amount. Furthermore, when one of the piezo actuators 4033d, 4036d expands, the other operates to contract by the same amount. At this time, the transmission members 4031b, 4032b, 4033b of the linear actuators 4031, 4032, 4033 and the transmission members 4034b, 4035b, 4036b of the air cylinders 4034, 4035, 4036 do not move. Therefore, the influence of the sliding resistance generated in the transmission members 4031b, 4032b, 4033b, 4034b, 4035b, 4036b can be suppressed.

Next, the joining device 1 determines whether it is impossible to cancel the changes in the distances L11, L12, L13, L14, L15, and L16 simply by extending and retracting the piezoelectric actuators 4031d, 4032d, 4033d, 4034d, 4035d, and 4036d in conjunction (step S114). If the joining device 1 determines that the changes in the distances L11, L12, L13, L14, L15, and L16 can be canceled simply by extending and retracting the piezoelectric actuators 4031d, 4032d, 4033d, 4034d, 4035d, and 4036d in conjunction (step S114: No), the process of step S110 is executed again. On the other hand, it is assumed that the welding apparatus 1 determines that it is impossible to cancel the changes in the distances L11, L12, L13, L14, L15, and L16 by simply extending and contracting the piezo actuators 4031d, 4032d, 4033d, 4034d, 4035d, and 4036d in conjunction with each other (step S114: Yes). In this case, the welding apparatus 1 moves the transmission members 4031b, 4032b, and 4033b by the transmission member driving units 4031a, 4032a, and 4033a so as to cancel the changes in the distances L11, L12, L13, L14, L15, and L16 (step S115). After that, the process of step S110 is executed again. In other words, if the distances L11, L12, L13, L14, L15, and L16 cannot be maintained constant simply by extending and contracting the piezoelectric actuators 4031d, 4032d, 4033d, 4034d, 4035d, and 4036d in conjunction with each other, the bonding device 1 controls the transmission member driving units 4031a, 4032a, and 4033a so that the distances L11, L12, L13, L14, L15, and L16 are maintained constant. In this way, the bonding apparatus 1 repeatedly executes the series of processes from steps S110 to S115 described above, and expands and contracts the piezoelectric actuators 4031d, 4032d, 4033d, 4034d, 4035d, and 4036d so that the distance between the table member 405 measured by the distance measurement units 521, 522, 523, 524, 525, and 526 at the time when the positioning of the two substrates W1 and W2 is provisionally completed is maintained constant, and 4031b, 4032b, and 4033b are moved appropriately.

On the other hand, it is assumed that the bonding apparatus 1 has determined that all of the distances L11, L12, L13, L14, L15, and L16 have not changed by more than the aforementioned distance threshold (step S112: No). In this case, the bonding apparatus 1 again measures the positional deviation amount of the substrate W2 relative to the substrate W1 (step S116). After that, the bonding apparatus 1 again determines whether all of the measured positional deviation amounts Δx, Δy, and Δθ of the substrate W2 relative to the substrate W1 are equal to or less than the aforementioned positional deviation amount thresholds Δxth, Δyth, and Δθth (step S117). Here, it is assumed that the bonding apparatus 1 has determined that any of the measured positional deviation amounts Δx, Δy, and Δθ is greater than the positional deviation amount thresholds Δxth, Δyth, and Δθth (step S117: No). In this case, the joining device 1 calculates the correction movement amount of the stage 401 based on the calculated positional deviation amounts Δx, Δy, and Δθ (step S107), and drives the transmission members 4031b, 4032b, and 4033b to move the stage 401 so that the movement amounts of the transmission members 4031b, 4032b, and 4033b detected by the linear encoders 531, 532, and 533 become the calculated correction movement amounts (step S108). Then, the process of step S105 is executed again.

On the other hand, it is assumed that the bonding apparatus 1 determines that all of the measured positional deviations Δx, Δy, and Δθ are equal to or less than the positional deviation thresholds Δxth, Δyth, and Δθth (step S117: Yes). In this case, the bonding apparatus 1 brings the substrate W2 into contact with the substrate W1 (step S118). At this time, the bonding apparatus 1 lowers the head 402 as shown by the arrow AR101 in FIG. 12(A), thereby bringing the substrates W1 and W2 into contact with each other as shown in FIG. 12(B). Next, the bonding apparatus 1 presses the substrate W2 against the substrate W1 to apply pressure, thereby bonding the substrates W1 and W2 to each other (step S119). Here, the bonding apparatus 1 first lowers the support member 4039 as shown by the arrow AR401 in FIG. 12(B) with the substrates W1 and W2 in contact with each other. As a result, the bottom surface of the table member 405 comes into surface contact with the upper surface of the support stand 406 as shown in FIG. 13. Therefore, even during pressure bonding, the table member 405 is less likely to bend, and the flatness of the table member 405 (and thus the substrate W1) can be maintained with high precision while bonding the substrates W1 and W2. It is preferable that the surface-supported area of the bottom surface of the table member 405 is large. For example, it is preferable that the entire area of the bottom surface of the table member 405 that corresponds to the substrate W1 is in surface contact with the support base 406. The bonding apparatus 1 then applies a driving force to the head 402 in the direction indicated by the arrow AR103 to press the substrate W2 against the substrate W1. At this time, the substrate heating units 481 and 482 may heat the substrates W1 and W2, respectively. In this manner, the substrates W1 and W2 are bonded to each other.

After that, the bonding device 1 stops the electrostatic chuck of the head 402 to release the substrate W2 (step S120). Next, the bonding device 1 raises the head 402 to separate it from the substrate W2.

In a typical bonding apparatus, the movement mechanism of the stage 401 in the XY direction and the movement mechanism in the rotation direction are separate, and an encoder and a distance detector that can detect the amount of movement in each movement direction can be arranged. In contrast, in the bonding apparatus 1 according to the present embodiment, the movement amount of the transmission member 4031b in the Y-axis direction and the movement amount of each of the transmission members 4032b and 4033b in the X-axis direction are adjusted to position the stage 401 fixed to the table member 405 in the ±X direction, ±Y direction, and rotation direction around the Z axis. For this reason, the positional deviation amount between the substrates W1 and W2 in the rotation direction around the Z axis of the stage 401 cannot be measured by the laser displacement sensor. In addition, when the table member 405 is rotated around the Z axis, the angle of incidence of the laser light emitted from the light-emitting elements of the distance measurement units 521, 522, 523, 524, 525, and 526 on the peripheral surface of the table member 405 changes. For this reason, the amount of light received by the linear image sensors of the distance measuring units 521, 522, 523, 524, 525, and 526 changes depending on the rotation angle of the table member 405 around the Z axis, making it difficult to accurately calculate the amount of positional deviation of the stage 401 in the ±X and ±Y directions based on the distance between the table member 405 and the distance measuring units 521, 522, 523, 524, 525, and 526.

In contrast, in the bonding apparatus 1 according to the present embodiment, after performing the processes of steps S103 and S104 described above, a primary operation is performed to provisionally position the substrates W1 and W2 relative to each other by repeating a series of processes from steps S105 to S108, and then a secondary operation is performed to maintain the stage 401 at the position at the time of completion of the provisional positioning by repeating a series of processes from steps S110 to S113. After that, the bonding apparatus 1 performs the processes of steps S114 and S115, and if it is determined that any of the positional deviation amounts Δx, Δy, and Δθ between the substrates W1 and W2 is greater than the positional deviation amount thresholds Δxth, Δyth, and Δθth, it performs a tertiary operation to position the substrates W1 and W2 relative to each other by repeating a series of processes from steps S105 to S108 again. 14, in the first and third operations, the bonding apparatus 1 calculates the positional deviation amounts Δx, Δy, Δθ between the two substrates W1, W2 based on the captured images GAa, GAb of the alignment marks MK1a, MK1b, MK2a, MK2b of the two substrates W1, W2 captured by the imaging units 501, 502, and calculates the correction movement amount of the substrate W1 relative to the substrate W2 based on the calculated positional deviation amounts. Then, the bonding apparatus 1 drives the transmission members 4031b, 4032b, 4033b to move the stage 401 so that the movement amounts of the transmission members 4031b, 4032b, 4033b detected by the linear encoders 531, 532, 533 become the calculated correction movement amounts. Furthermore, the bonding apparatus 1 expands and contracts the piezo actuators 4031d, 4032d, 4033d, 4034d, 4035d, and 4036d and moves the transmission members 4031b, 4032b, and 4033b so that the distance between the table member 405 measured by the distance measuring units 521, 522, 523, 524, 525, and 526 at the time when the positioning of the two substrates W1 and W2 is provisionally completed is maintained constant. At this time, the movement amount of the transmission members 4031b, 4032b, and 4033b detected by the linear encoders 531, 532, and 533 is ignored.

That is, the bonding apparatus 1 executes a first step of calculating a correction movement amount of the stage 401 based on the positional deviation amount between the images of the alignment marks MK1a, MK2a and the images of the alignment marks MK1b, MK2b captured by the imaging units 501, 502, and controlling the linear actuators 4031, 4032, 4033 based on the position adjustment amount detected by the linear encoders 531, 532, 533 so as to move the stage 401 by the calculated correction movement amount. After that, when the positional deviation amount between the images of the alignment marks MK1a, MK2a and the alignment marks MK1b, MK2b becomes equal to or less than the above-mentioned positional deviation amount threshold and the positioning of the substrates W1, W2 is provisionally completed, the bonding apparatus 1 executes a second step of controlling the linear actuators 4031, 4032, 4033 so that the distances L11, L12, L13, L14, L15, L16 at the provisional completion of the positioning are maintained constant. In the second step, the welding device 1 may control the linear actuators 4031, 4032, 4033 by using the position adjustment amounts detected by the linear encoders 531, 532, 533. However, it is preferable that the welding device 1 controls the linear actuators 4031, 4032, 4033 by using the distances L11, L12, L13, L14, L15, L16 measured by the distance measuring units 521, 522, 523, 524, 525, 526 without using the position adjustment amounts detected by the linear encoders 531, 532, 533. Then, after performing the aforementioned first and second steps, the joining device 1 captures images of the alignment marks MK1a, MK2a and the alignment marks MK1b, MK2b using the imaging units 501, 502, calculates the amount of positional deviation between the captured images of the alignment marks MK1a, MK2a and the images of the alignment marks MK1b, MK2b, and if the calculated amount of positional deviation exceeds a positional deviation threshold, again performs the aforementioned first and second steps. In this way, the bonding apparatus 1 can accurately calculate the amount of misalignment of the substrate W1 relative to the substrate W2 in the ±X and ±Y directions, as well as the amount of misalignment in the direction of rotation around the Z axis, using the captured images GAa, GAb of the alignment marks MK1a, MK1b, MK2a, MK2b of the two substrates W1, W2 and the distance between the table member 405 measured by the distance measuring units 521, 522, 523, 524, 525, 526.

Here, the characteristics of the joining device 1 according to the present embodiment will be described while comparing it with the joining devices according to the comparative examples 1 and 2. As shown in FIG. 15(A), the joining device according to the comparative example 1 has lubricating members 9405a and 94039a on the opposing sides of the table member 9405 and the support member 94039, and the table member 9405 and the support member 94039 are in surface contact via the lubricating members 9405a and 94039a. Note that in FIG. 15(A), the same components as those in the embodiment are given the same reference numerals as in FIG. 5. In the joining device according to the comparative example 1, sliding resistance occurs in the portion Po2 between the support member 94039 supporting the table member 9405 and the table member 9405, and in the portion Po1 between the pistons 4034e, 4035e, and 4036e and the cylinder main bodies 4034a, 4035a, and 4036a. For this reason, even if a driving force is applied to move the table member 9405 by a small distance, it may not move. In this case, the table member 9405 may bend, or as shown in FIG. 15B, the support members 4031c4, 4032c4, 4033c4, 4034c4, 4035c4, and 4036c4 of the bearings 4031c, 4032c, 4033c, 4034c, 4035c2, and 4036c may bend, or the spherical rolling elements 4031c2, 4032c2, 4033c2, 4034c2, 4035c2, and 4036c2 may be crushed and deformed into an ellipsoid shape. If this is the case, when time has passed since the driving force was applied, the table member 9405 and the bearings 4031c, 4032c, 4033c, 4034c, 4035c, and 4036c will recover from their bent or deformed state, which may cause the table member 9405 to move further and result in misalignment.

In contrast, according to the bonding apparatus 1 of this embodiment, after the positioning of the substrate W2 relative to the substrate W1 is completed, the control unit 9 controls the linear actuators 4031, 4032, 4033 so that the distances L11, L12, L13, L14, L15, L16 measured by the distance measuring units 521, 522, 523, 524, 525, 526 at the time of completion of the positioning are maintained constant. As a result, even if the substrate W2 moves further relative to the substrate W1 due to distortion of the stage 401, sliding resistance of the air cylinders 4034, 4035, 4036, etc. after the positioning of the substrate W2 relative to the substrate W1 is completed, the substrate W2 can be bonded to the substrate W1 with high positional accuracy.

16, the joining device according to Comparative Example 2 includes an X-direction drive unit 94031 that moves the stage 401 in the X-axis direction as shown by the arrow AR901 vertically below the stage 401, a Y-direction drive unit 94032 that is arranged so as to overlap the X-direction drive unit 94031 vertically and moves the stage 401 in the Y-axis direction as shown by the arrow AR902, and a rotation drive unit 94033 that rotates the stage 401 as shown by the arrow AR903. Here, the Y-direction drive unit 94032 has a rail 94032b that extends in the Y-axis direction and a slide member 94032a that supports the stage 401 and moves on the rail 94032b. In this case, as shown by the arrow AR900, when the substrates W1 and W2 are pressurized, depending on the position of the stage 401 in the X-axis direction and the Y-axis direction, the force applied to the X-direction drive unit 94031 and the Y-direction drive unit 94032 may become uneven, and the posture of the stage 401 may be tilted. In addition, since the X-direction drive unit 94031, the Y-direction drive unit 94032, and the rotation drive unit 94033 are arranged vertically below the stage 401, the magnitude of the force that can be applied to the stage 401 when the substrates W1 and W2 are pressurized is limited. In addition, if the rotation drive unit 94033 is configured to include a bearing that supports the inner ring that supports the stage 401 from vertically below via a rolling body by an outer ring fixed to the vertical upper side of the slide member 94032a, when pressure is applied to the center of the stage 401, there is a risk that the portion of the stage 401 facing the center of the inner ring may bend so as to be recessed vertically downward.

In contrast, in the bonding apparatus 1 according to this embodiment, as shown in FIG. 13, a support base 406 is arranged vertically below the stage 401 and table member 405, and the stage 401 is moved horizontally by applying a force from the side of the table member 405 using linear actuators 4031, 4032, and 4033. As a result, when the substrates W1 and W2 are pressurized, the stage 401 and table member 405 are supported by the support base 406, which is fixed in position and has a flat upper surface, so that tilting and bending of the stage 401 is suppressed. This is therefore preferable when the substrates W1 and W2 are pressurized together with a high pressure of, for example, 1 kN or more.

Furthermore, in the bonding apparatus 1 according to this embodiment, linear actuators 4031, 4032, and 4033 for moving the stage 401 in the horizontal direction are arranged around the stage 401. Therefore, for example, a configuration for irradiating the substrates W1 and W2 with ultraviolet light can be arranged vertically below the stage 401.

In addition, in the bonding device shown in FIG. 16, the X-direction drive unit 94031, the Y-direction drive unit 94032, and the rotation drive unit 94033 can each be provided with an encoder, a laser displacement meter, or the like for detecting displacement in the moving direction. However, in the configuration shown in FIG. 16, particularly when pressure needs to be applied to the substrates W1 and W2 and high-precision alignment is required, problems such as those described above arise, and it is necessary to adopt a configuration such as the bonding device 1 of this embodiment. In this case, it is necessary to adopt a configuration using linear actuators 4031, 4032, and 4033 and air cylinders 4034, 4035, and 4036, as in the bonding device 1 of this embodiment.

Although the embodiment of the present invention has been described above, the present invention is not limited to the configuration of the above-mentioned embodiment. For example, the distance measurement units 521, 522, 523, 524, 525, and 526 may measure distance using a range finder other than a laser range finder.

In the embodiment, the linear actuators 4031, 4032, and 4033 have piezo actuators 4031d, 4032d, and 4033d, respectively, and the air cylinders 4034, 4035, and 4036 have piezo actuators 4034d, 4035d, and 4036d, respectively. However, this is not limited to this, and for example, as shown in FIG. 17, the linear actuators 24031, 24032, and 24033 may not have piezo actuators, and the air cylinders 24034, 24035, and 24036 may not have piezo actuators. In FIG. 17, the same reference numerals as in FIG. 4(A) are used for the same configuration as in the embodiment. In this case, the control unit 9 controls the transmission member drive units 4031a, 4032a, and 4033a so that the distance between the distance measurement units 521, 522, 523, 524, 525, and 526 and the table member 405 measured by the distance measurement units 521, 522, 523, 524, 525, and 526 at the time of provisional completion of positioning is maintained constant.

Here, the joining method performed by the joining device according to this modified example will be described with reference to FIG. 18. In FIG. 18, the same steps as those in the first embodiment are denoted by the same reference numerals as those in FIG. 11. After the step S109 is performed, the joining device waits for a preset time (step S110) and then measures the distances L11, L12, L13, L14, L15, and L16 again using the distance measuring units 521, 522, 523, 524, 525, and 526 (step S111). Next, the joining device determines whether or not at least one of the measured distances L11, L12, L13, L14, L15, and L16 has changed by the aforementioned distance threshold or more before and after step S111 (step S112). Here, it is assumed that the joining device has determined that at least one of the distances L11, L12, L13, L14, L15, and L16 has changed by the aforementioned distance threshold or more (step S112: Yes). In this case, the joining device controls the transmission member drive units 4031a, 4032a, and 4033a to move the transmission members 4031b, 4032b, and 4033b so as to cancel the changes in the distances L11, L12, L13, L14, L15, and L16 (step S2111). Then, the process of step S110 is executed again. On the other hand, if the joining device determines that all of the distances L11, L12, L13, L14, L15, and L16 have not changed by more than the aforementioned distance threshold (step S112: No), the process of steps S116 and onward is executed.

This configuration allows the configuration of each of the linear actuators 24031, 24032, and 24033 and the air cylinders 24034, 24035, and 24036 to be simplified.

In the embodiment, an example has been described in which the table member 405 is supported by three support members 4039 arranged on the bottom side thereof. However, this is not limited to this, and for example, as shown in FIG. 19, a support base 3406 may be provided with a lubricating member 3406a such as a Teflon (registered trademark) sheet attached to the vertical upper side. Note that in FIG. 19, the same components as those in the embodiment are given the same reference numerals as those in FIG. 3.

In the embodiment, an example has been described in which the transmission member drive units 4031a, 4032a, and 4033a rotate the feed screws 4031e, 4032e, and 4033e to protrude and retract the transmission members 4031b, 4032b, and 4033b. However, this is not limited to the above, and for example, the transmission member drive unit may have a linear servo motor in which the primary unit moves along the longitudinal direction of the long secondary unit, and directly protrude and retract the transmission members 4031b, 4032b, and 4033b fixed to the primary unit.

In an embodiment, the stage 401 and the head 402 may have a pressing mechanism that presses the central portions of the substrates W1 and W2.

In the embodiment, an example has been described in which the distance measurement unit 490 measures the distance between the stage 401 and the head 402. However, this is not limiting, and the distance measurement unit may measure the distance between the substrate W1 held by the stage 401 and the head 402, or the distance between the stage 401 and the substrate W2 held by the head 402. Alternatively, the distance measurement unit may measure the distance between the substrate W1 held by the stage 401 and the substrate W2 held by the head 402.

In the embodiment, an example in which the substrates W1 and W2 are bonded together under reduced pressure has been described, but this is not limited thereto, and the substrates W1 and W2 may also be bonded together under atmospheric pressure.

In the embodiment, an example has been described in which the distance measuring units 521, 522, 523, 524, 525, and 526 are laser displacement sensors, but the present invention is not limited to this. For example, the distance measuring units 521, 522, 523, 524, 525, and 526 may be side length sensors that have a light-emitting element and a light-receiving element or an image sensor, and measure the distance based on the amount of light received by the light-receiving element or the size of the image detected by the image sensor. Alternatively, the distance measuring units 521, 522, 523, 524, 525, and 526 may be eddy current displacement sensors that have a sensor head with a built-in coil that generates a high-frequency magnetic field, and measure the distance based on the amount of change in the impedance of the coil.

The present invention allows for various embodiments and modifications without departing from the broad spirit and scope of the present invention. Furthermore, the above-described embodiments are intended to explain the present invention and do not limit the scope of the present invention. In other words, the scope of the present invention is indicated by the claims, not the embodiments. Furthermore, various modifications made within the scope of the claims and within the scope of the meaning of the invention equivalent thereto are considered to be within the scope of the present invention.

The present invention is suitable for manufacturing, for example, CMOS image sensors, memories, computing elements, and MEMS.

1: Bonding device, 9: Control unit, 120: Chamber, 121a: Vacuum pump, 121b: Exhaust pipe, 121c: Exhaust valve, 401: Stage, 402: Head, 403: Stage drive unit, 404: Head drive unit, 405: Table member, 406, 3406: Support base, 408, 412: Pressure sensor, 411, 4031d, 4032d, 4033d, 4034d, 4035d, 4036d: Piezo actuator, 481, 482: Substrate heating unit, 490, 521, 522, 523, 524, 525, 5 26: distance measuring section, 500: imaging unit, 501, 502: imaging section, 504, 505: mirror, 531, 532, 533: linear encoder, 3406a: lubricating member, 4031, 4032, 4033, 24031, 24032, 24033: linear actuator, 4031b, 4032b, 4033b, 4034b, 4035b, 4036b: transmission member, 4031a, 4032a, 4033a: transmission member drive section, 4031c, 4032c, 4033c, 4034c, 4035c, 403 6c: bearing, 4031c1, 4032c1, 4033c1, 4034c1, 4035c1, 4036c1: outer ring, 4031c2, 4032c2, 4033c2, 4034c2, 4035c2, 4036c2, 4031g, 4032g, 4033g: rolling elements, 4031c3, 4032c3, 4033c3, 4034c3, 4035c3, 4036c3: inner ring, 4031c4, 4032c4, 4033c4, 4034c4, 4035c4, 4036c4, 4039: support member, 4031e , 4032e, 4033e: feed screw, 4031f, 4032f, 4033f: linear guide, 4031h, 4032h, 4033h: nut part, 4034, 4035, 4036: air cylinder, 4034a, 4035a, 4036a: cylinder body, 4034e, 4035e, 4036e: piston, 4041: XY direction drive part, 4042: lift drive part, 4043: rotation drive part, Ga, Gb: photographed image, MK1a, MK1b, MK2a, MK2b: alignment mark, W1, W2: substrate

Claims (12)

1. An alignment apparatus for aligning a first object with respect to a second object, comprising:
A first object holder that holds the first object;
A second object holder that holds the second object ;
a linear actuator for adjusting a position of the first object holder in a first direction;
a distance measuring unit that is disposed around the first object holder and measures a distance between the first object holder and the distance measuring unit;
a control unit that controls the linear actuator so that, when a position of the first object relative to the second object changes due to a change in position of the first object holding unit after provisional completion of positioning of the first object relative to the second object and a distance between the distance measurement unit and the first object holding unit changes, the distance between the distance measurement unit and the first object holding unit measured by the distance measurement unit becomes equal to the distance between the distance measurement unit and the first object holding unit measured by the distance measurement unit at the provisional completion of positioning.
Alignment device. The distance measurement unit is provided for each of the linear actuators.
2. The alignment apparatus of claim 1. a support member that supports the first object holder so as to be horizontally movable relative to the second object holder;
At least one biasing portion biases the first object holding portion in the first direction.
3. An alignment apparatus according to claim 1 or 2. The actuator includes three pairs of the urging unit and the linear actuator arranged to face the urging unit with the first object holding unit interposed therebetween,
The opposing direction of the biasing portion and the linear actuator of two of the three sets is the same, and the opposing direction of the biasing portion and the linear actuator of the remaining set intersects with the opposing direction of the biasing portion and the linear actuator of the two sets.
4. The alignment apparatus according to claim 3 . the first object has a first alignment mark;
the second object has a second alignment mark;
an imaging unit that images the first alignment mark and the second alignment mark,
the control unit determines a position of the first object relative to the second object based on an image of the first alignment mark and an image of the second alignment mark captured by the imaging unit at the time of provisional completion of the positioning.
3. An alignment apparatus according to claim 1 or 2. 1. An alignment apparatus for aligning a first object with respect to a second object, comprising:
A first object holder that holds the first object;
A second object holder that holds the second object;
a support member that supports the first object holder so as to be horizontally movable relative to the second object holder;
At least one biasing portion that biases the first object holding portion in a first direction;
a linear actuator for adjusting a position of the first object holder in the first direction;
a distance measuring unit that is disposed around the first object holder and measures a distance between the first object holder and the distance measuring unit;
a control unit that controls the linear actuator so that, after the positioning of the first object relative to the second object is provisionally completed, a distance between the distance measurement unit and the first object holding unit measured by the distance measurement unit at the time of provisional completion of the positioning is maintained constant,
the first object has a first alignment mark;
the second object has a second alignment mark;
an imaging unit that images the first alignment mark and the second alignment mark,
the linear actuator has a linear encoder that detects an amount of position adjustment of the first object holder by the linear actuator,
the control unit executes a first step of calculating a correction movement amount of the first object holding unit based on a positional deviation amount between the image of the first alignment mark and the image of the second alignment mark captured by the imaging unit, and controlling the linear actuator based on the position adjustment amount detected by the linear encoder so as to move the first object holding unit by the calculated correction movement amount, and then executes a second step of controlling the linear actuator so that, when the positional deviation amount between the image of the first alignment mark and the image of the second alignment mark becomes equal to or less than a predetermined positional deviation amount threshold and positioning of the first object relative to the second object is provisionally completed, the control unit executes a second step of controlling the linear actuator so that the distance between the distance measurement unit and the first object holding unit measured by the distance measurement unit at the time of provisional completion of positioning is maintained constant.
Alignment device. after executing the first step and the second step, an image of the first alignment mark and an image of the second alignment mark are captured by the imaging unit, a positional deviation amount between the captured images of the first alignment mark and the second alignment mark is calculated, and when the calculated positional deviation amount exceeds the positional deviation amount threshold, the first step and the second step are executed again.
7. An alignment apparatus according to claim 6 . The linear actuator comprises:
A first transmission member for transmitting a pressing force to the first object holding portion;
a feed screw that is screwed into a portion of the first transmission member;
a transmission member driving portion that drives the first transmission member in the first direction or in a second direction opposite to the first direction;
a first piezoelectric actuator provided on the first transmission member and configured to expand and contract a length in a direction along the first direction and the second direction,
The linear encoder detects the amount of movement of the first transmission member,
The biasing portion is
A second transmission member for transmitting a pressing force to the first object holder;
a second piezoelectric actuator provided on the second transmission member and configured to expand and contract a length in a direction along the first direction and the second direction,
the control unit controls the first piezo actuator and the second piezo actuator to extend and contract in conjunction with each other so that, when the positioning of the first object relative to the second object is provisionally completed, a distance between the distance measurement unit and the first object holding unit measured by the distance measurement unit at the time of provisional completion of the positioning is maintained constant.
8. An alignment apparatus according to claim 6 or 7 . The distance measurement unit has a laser displacement sensor.
An alignment apparatus according to any one of claims 1 to 7 . 1. A method for aligning a first object with a second object, comprising:
positioning the first object relative to the second object;
After the positioning is provisionally completed, a distance measurement unit disposed around a first object holder that holds the first object measures a distance between the distance measurement unit and the first object holder at the time of provisional completion of the positioning;
and when, after the positioning of the first object relative to the second object is provisionally completed, the position of the first object holder changes, thereby causing a change in the position of the first object relative to the second object and changing the distance between the distance measurement unit and the first object holder, moving the first object holder so that the distance between the distance measurement unit and the first object holder measured by the distance measurement unit becomes equal to the distance between the distance measurement unit and the first object holder measured by the distance measurement unit at the time of provisional completion of the positioning.
Alignment method. 1. A method for aligning a first object with a second object, comprising:
the first object has a first alignment mark;
the second object has a second alignment mark;
a first step of calculating a correction movement amount of a first object holding unit that holds the first object based on a positional deviation amount between an image of the first alignment mark and an image of the second alignment mark captured by an imaging unit that captures the first alignment mark and the second alignment mark, and controlling a linear actuator that adjusts the position of the first object holding unit in a first direction so as to move the first object holding unit by the calculated correction movement amount, based on the position adjustment amount detected by a linear encoder that detects the position adjustment amount of the first object holding unit by the linear actuator;
and a second step of controlling the linear actuator so that, when a positional deviation amount between the image of the first alignment mark and the image of the second alignment mark becomes equal to or less than a predetermined positional deviation amount threshold and positioning of the first object relative to the second object is provisionally completed, a distance between the first object holding part and a distance measuring unit disposed around the first object holding part and measuring the distance between the first object holding part is maintained constant at the time of provisional completion of positioning.
Alignment method. after performing the first step and the second step, an image of the first alignment mark and an image of the second alignment mark are captured by the imaging unit, a positional deviation amount between the captured images of the first alignment mark and the second alignment mark is calculated, and when the calculated positional deviation amount exceeds the positional deviation amount threshold, the first step and the second step are performed again.
The alignment method according to claim 11 .

Images