JP4501174B2 - Substrate positioning device and substrate bonding device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate positioning apparatus and a substrate bonding apparatus using the same, and is particularly suitable for use in positioning and bonding two substrates forming a liquid crystal display panel.
[0002]
[Prior art]
A manufacturing process of a liquid crystal display device (LCD) includes a process of aligning and bonding a TFT substrate on which thin film transistors (TFTs) are arranged in an array and a CF substrate on which color filters (CF) are formed. In this process, the TFT substrate and the CF substrate are aligned with reference to the alignment mark provided on each substrate, using a substrate bonding apparatus having a substrate positioning function. Further, after the alignment of the substrates, the two substrates (TFT substrate and CF substrate) are bonded together with a sealant.
[0003]
FIG. 6 is a perspective view showing a schematic configuration of a conventional substrate bonding apparatus. In FIG. 6, a base plate 52 is attached to the upper end portion of the gantry frame 51. At the four corners of the base plate 52, pillars 53 are set up vertically, and the upper plate 54 is supported by these pillars 53 in a horizontal state. Two actuators (cylinders and the like) 55 are attached to the upper plate 54, and a pressure platen 56 is attached to the output shaft (rod) of each actuator 55.
[0004]
Imaging cameras 57 such as CCD cameras are arranged at the four corners of the pressure platen 56. These imaging cameras 57 are for reading an image (shape) of the alignment mark M provided on the TFT substrate 58 and the CF substrate 59 to be aligned, and accurately recognizing the position.
[0005]
On the other hand, on the base plate 52, as shown in FIGS. 7A and 7B, an X stage 60, a Y stage 61, and a θ stage 62 are sequentially stacked. The X stage 60 is supported so as to be movable in the X direction by a plurality of linear motion guides 63 incorporated between the X stage 60 and the base plate 52. The Y stage 61 is supported by a plurality of linear guides 64 incorporated between the Y stage 61 and the X stage 60 so as to be movable in the Y direction. The θ stage 62 has a cylindrical member 65 mounted on the Y stage 61 and an annular bearing member 66 fitted to the upper end portion of the cylindrical member 65, and is centered on the Z axis passing through the center O of the XY coordinates. It is supported so as to be movable (rotatable) in the direction.
[0006]
On the base plate 52, a rotary drive motor 67 is mounted on the X axis. The drive motor 67 is connected to a ball screw shaft 69 through a coupling member 68. On the other hand, a ball screw nut 70 is attached to the lower surface of the X stage 60, and this ball screw nut 70 is engaged with the ball screw shaft 69. In this configuration, when the ball screw shaft 69 is rotated by driving the drive motor 67, the ball screw nut 70 moves on the shaft according to the rotation direction and the rotation amount, and the X stage 60 is integrated with the linear motion guide 63. Guided and moved in the X direction.
[0007]
On the other hand, on the X stage 60, a rotary drive motor 71 is mounted on the Y axis. The drive motor 71 is connected to the ball screw shaft 73 via a coupling member 72. On the other hand, a ball screw nut 74 is attached to the lower surface of the Y stage 61, and this ball screw nut 74 is engaged with the ball screw shaft 73. In this configuration, when the ball screw shaft 73 is rotated by driving the drive motor 71, the ball screw nut 74 moves on the shaft in accordance with the rotation direction and the rotation amount, and the Y stage 61 is integrated with the linear motion guide 64. Guided and moved in the Y direction.
[0008]
Further, a linear motion drive motor (linear motor) 75 is mounted on the Y stage 61 along the Y direction. The output shaft of the drive motor 75 is abutted against an operation member 76 attached to the side end surface of the θ stage 62. Further, a compression spring (coil spring) 77 is provided on the side of the operation member 76 opposite to the abutting side with the drive motor 75, and the operation member 76 is always biased toward the drive motor 75 by the spring pressure of the compression spring 77. Has been. In this configuration, when the operation member 76 is moved in the Y direction by driving the drive motor 75, the θ stage 62 is guided by the bearing member 66 and moved (rotated) in the θ direction in conjunction therewith.
[0009]
In the substrate bonding apparatus having the above-described configuration, the TFT substrate 58 and the CF substrate 59 are supplied from the direction indicated by the arrow A and the direction indicated by the arrow B by a substrate transfer device (not shown). At this time, the TFT substrate 58 is transferred to the pressure platen 56 and is sucked and held on the lower surface side of the platen by a vacuum force or the like. Further, the CF substrate 59 is transferred to the θ stage 62 and is sucked and held on the upper surface side of the stage by a vacuum force or the like. As a result, the TFT substrate 58 and the CF substrate 59 are arranged in a state in which they face each other in the vertical direction (Z-axis direction).
[0010]
Subsequently, the pressure platen 56 is lowered to a position near the θ stage 62 by driving the actuator 55. In this state, the alignment marks M provided at the four corners of each substrate are image-recognized by the corresponding imaging cameras 57, and the mark center coordinates are grasped from the recognition result. Then, the drive motors 67, 71, 75 are driven based on the grasped mark center coordinates to move the X, Y, θ stages 60, 61, 62 as appropriate, and thereby the mark center position of the TFT substrate 58 and the CF substrate. Align the 59 mark center position. Next, the X stage 60 is further lowered and pressed by the driving of the actuator 55 and the driving force, whereby the TFT substrate 58 and the CF substrate 59 are bonded together via a sealing material (not shown).
[0011]
After that, with the vacuum suction of the pressurizing platen 56 released, the pressurizing platen 56 is lifted (retracted) by driving the actuator 55, and then a bonded substrate (58 + 59) composed of the TFT substrate 58 and the CF substrate 59. Is taken out from the X stage 60 in the B ′ direction by a substrate transfer device (not shown) and transferred to the next process.
[0012]
When such substrates are bonded together, if the alignment between the substrates is not performed accurately, when an image is displayed using the liquid crystal display panel obtained thereby, color unevenness, moire, aperture ratio error, etc. Will cause problems.
[0013]
[Problems to be solved by the invention]
By the way, in the above conventional substrate bonding apparatus, when the X and Y stages 60 and 61 are moved in the X direction and the Y direction, respectively, the ball screw shafts 69 and 73 serving as drive axes thereof are moved in the moving direction of the stages 60 and 61. (X direction, Y direction) are mounted in the same direction, and the load accompanying the stage movement (hereinafter referred to as “alignment load”) remains the same and acts in the axial direction of each ball screw shaft 69, 73. It has become. In such a case, if the ball screw shafts 69 and 73 are expanded and contracted in the axial direction due to the alignment load, the substrate positioning accuracy is lowered. In particular, since positioning of the TFT substrate 58 and the CF substrate 59 requires submicron order accuracy, it is necessary to suppress the deformation of the ball screw shafts 69 and 73 as much as possible in order to meet this requirement.
[0014]
Further, the TFT substrate 58 and the CF substrate 59 are bonded to each other through a sealing material (not shown) in a state where the pressing force P is applied to the pressure platen 56 by the driving force of the actuator 55, and in this state, the X and Y stages 60 , 61 are moved, the alignment load F is “F = P · μ”, where μ is the frictional resistance with the sealing material. Furthermore, the amount of shaft deformation (axial expansion / contraction deformation amount) δ when the alignment load F acts on the ball screw shafts 69 and 73 is “δ = F · L / A · E”. Here, A is the cross-sectional area of the ball screw shaft, L is the length of the ball screw shaft, and E is the elastic coefficient of the ball screw shaft. From this formula, in order to suppress the deformation amount of the ball screw shaft, it is necessary to increase the cross-sectional area A and shorten the length L of the ball screw shaft. However, there is a limit to shortening the length L of the ball screw shaft, and when the cross-sectional area A is increased, the height H of the entire stage is increased accordingly, so that the bending moment due to the Abbe offset increases. It becomes difficult to perform highly accurate positioning.
[0015]
Further, in the drive system of the θ stage 62, since the backlash of the drive system is removed by providing the compression spring 77 so as to oppose the thrust of the drive motor 75, the alignment force Fθ by this drive system is When the thrust of 75 is Pm and the spring pressure of the compression spring 77 is Ps, “Fθ = Pm−Ps”. At this time, since the operation member 76 is pushed back to the drive motor 75 side only by the spring pressure Ps of the compression spring 77, if the alignment load is increased by the pressure P applied by the pressurizing surface plate 56, the spring pressure is increased accordingly. At the same time, Ps is required, and at the same time, a motor thrust Pm is required to counter the spring pressure Ps. For this reason, it is difficult to achieve both high-precision positioning in the θ direction and downsizing of the drive system of the θ stage 62.
[0016]
Further, as another configuration of the drive system of the X, Y, θ stages 60, 61, 62, for example, there is one using a cam mechanism as shown in FIG. That is, the drive system of the X stage 60 includes an eccentric cam 79 that is attached to the motor shaft of the drive motor 78, and a cam follower 81 that contacts the eccentric cam 79 by the spring pressure of the compression spring 80. By moving the cam follower 81 in the X direction according to the amount of eccentricity when the eccentric cam 79 is rotated by the above, the X stage 60 can be moved in the X direction while being guided by the linear motion guide 63. Further, the drive system of the Y stage 61 includes an eccentric cam 82 that is attached to a motor shaft of a drive motor (not shown), and a cam follower 84 that contacts the eccentric cam 82 by the spring pressure of the compression spring 83. By moving the cam follower 84 in the Y direction according to the amount of eccentricity when the eccentric cam 82 is rotated by a drive motor (not shown), the Y stage 61 can be moved in the Y direction while being guided by the linear motion guide 64. It has become. Furthermore, the drive system of the θ stage 62 includes an eccentric cam 86 that is pivotally attached to the motor shaft of the drive motor 85 and a cam follower 88 that abuts the eccentric cam 86 by the spring pressure of the compression spring 87. Accordingly, the cam follower 88 is displaced in the Y direction according to the amount of eccentricity when the eccentric cam 86 is rotated, so that the θ stage 62 can be moved (rotated) in the θ direction while being guided by the bearing member 66. ing.
[0017]
However, even when the cam mechanism is used, when the X, Y, θ stages 60, 61, 62 are moved, the load acts on the drive source (motor) side as it is, and the stage is moved. Because it uses spring pressure, it had the same problem as described above. Furthermore, even if any of the mechanical mechanisms shown in FIGS. 7 and 8 is employed, the accuracy of the drive system greatly depends on the processing accuracy of the ball screw and the eccentric cam, so that there is a difficulty in positioning on the submicron order.
[0018]
[Means for Solving the Problems]
In the substrate positioning apparatus according to the present invention, the stage is positioned so as to be movably supported in a predetermined direction, and the stage for positioning the substrate to be processed in the predetermined direction, and the load application direction associated with the movement of the stage. A drive shaft arranged in a direction orthogonal to the application direction, and moved by driving the drive shaft engaged with the drive shaft. First A moving member that is regulated in the axial direction of the drive shaft by a guide member, and a tapered portion that connects the moving member and the stage and has a predetermined inclination with respect to the axial direction of the drive shaft at the connecting portion And a second guide member And a taper guide mechanism for converting the movement operation of the moving member by driving the drive shaft into the movement operation of the stage in accordance with the inclination of the taper portion. The first guide member and the second guide member are each constituted by a linear motion guide, and are arranged in two planes orthogonal to each other, so that the linear motion guide constituting the first guide member The intersection between the center axis extending in the direction of the drive shaft from the center position in the width direction and the center axis extending in the direction of the drive shaft from the center position in the width direction of the linear guide constituting the second guide member The axis of the drive shaft is arranged The configuration is adopted.
[0019]
In the substrate positioning apparatus having the above configuration and the substrate bonding apparatus using the same, when the moving member is moved by driving the drive shaft, the moving operation is converted into the moving operation of the stage by the taper guide mechanism. Thereby, it becomes possible to position the substrate to be processed by moving the stage in a predetermined direction. Further, when positioning the substrate to be processed, the load when moving the stage is reduced by the tapered portion and acts on the drive shaft side, and the load is received by the guide member in a direction orthogonal to the axial direction of the drive shaft. . As a result, the deformation of the drive shaft can be minimized.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of the present invention when applied to, for example, a substrate bonding apparatus used for manufacturing a liquid crystal display device will be described in detail with reference to the drawings.
[0021]
FIG. 1 is a perspective view showing a schematic configuration of a substrate bonding apparatus according to an embodiment of the present invention, and FIG. 2 is a side view thereof. 1 and 2, a base plate 2 is attached to the upper end portion of the gantry plate 1. At the four corners of the base plate 2, pillars 3 stand vertically, and top plates 4 are attached to the upper ends of these pillars 3 in a horizontal state. Two actuators (cylinders or the like) 5 are attached to the top plate 4.
[0022]
An upper plate 6 is disposed below the top plate 4. As shown in FIG. 2, brackets 7 are fixed to the four corners of the lower surface of the upper plate 6 with screws or the like. Further, a linear motion guide 8 for raising and lowering is incorporated between each bracket 7 and the column 3 corresponding thereto, and the upper plate 6 is supported by the linear motion guide 8 so as to be movable up and down. Further, output shafts (rods) 5 a of the two actuators 5 are connected to the upper plate 6. With this configuration, when the output shaft 5a of the actuator 5 moves back and forth, the upper plate 6 is guided by the linear motion guide 8 and moves up and down in the direction of arrow C in conjunction therewith. Incidentally, in FIG. 1, the display of the bracket 7 and the linear guide 8 for raising and lowering is omitted.
[0023]
Further, an X stage 9 is attached to the lower surface side of the upper plate 6. The X stage 9 includes a holding mechanism for holding a substrate to be processed (described later) by a vacuum suction force on the lower surface side, and a plurality of linear motions built between the X stage 9 and the upper plate 6. The guide 10 is supported so as to be movable in the X direction. A drive system (hereinafter referred to as “X-axis drive system”) 11 for moving the X stage 9 in the X direction is provided near the X stage 9.
[0024]
Imaging cameras 12 such as CCD cameras are arranged at the four corners of the X stage 9. These imaging cameras 12 read an image (shape) of the alignment mark M provided on the substrate to be aligned, in this case, the TFT substrate 13 and the CF substrate 14, and recognize the position accurately. belongs to. Among these, the TFT substrate 13 is supplied to the X stage 9 from the direction of arrow A by a substrate transfer device (not shown), and the X stage 9 is orthogonal to the substrate supply direction (substrate transfer direction) A. The moving direction X is set.
[0025]
On the other hand, a Y stage 15 and a θ stage 16 are sequentially stacked on the base plate 2. The Y stage 15 is supported movably in the Y direction by a plurality of linear motion guides 17 incorporated between the Y stage 15 and the base plate 2. The θ stage 16 includes a holding mechanism for holding the substrate to be processed (CF substrate 14 in this embodiment) on the upper surface side thereof by a vacuum suction force or the like, and a cylindrical member 18 mounted on the Y stage 15 and the cylindrical member 18. An annular bearing member 19 fitted in the upper end portion of the cylindrical member 18 is supported so as to be movable (rotatable) in the θ direction around the Z axis passing through the center of the XY coordinates. Further, the CF substrate 14 is supplied to the θ stage 16 from the direction of the arrow B by a substrate transfer device (not shown), and the Y direction is perpendicular to the substrate supply direction (substrate transfer direction) B. The moving direction Y of the stage 15 is set.
[0026]
Further, a drive system (hereinafter referred to as “Y-axis drive system”) 20 for moving the Y stage 15 in the Y direction is provided in the vicinity of the Y stage 15. A drive system (hereinafter referred to as “θ-axis drive system”) 21 for moving (turning) is provided.
[0027]
Subsequently, a basic operation procedure of the substrate bonding apparatus according to the present embodiment will be described. First, of the TFT substrate 13 and the CF substrate 14 to be processed, the TFT substrate 13 is supplied to the X stage 15 from the direction of arrow A, and the CF substrate 14 is supplied to the θ stage 16 from the direction of arrow B. At this time, when positioning the substrate in the θ direction, if the center positions of the TFT substrate 13 and the CF substrate 14 do not coincide with the rotation center (Z-axis) of the θ stage 16, the rotation center of the θ stage 16 Since the distances to the alignment marks M provided at the four corners of each substrate are different, accurate positioning is difficult.
[0028]
On the other hand, in the apparatus configuration of the present embodiment, the moving direction X of the X stage 9 is set in a direction orthogonal to the supply direction A of the TFT substrate 13 while the supply direction B of the CF substrate 14 is set. Since the moving direction Y of the Y stage 15 is set in a direction orthogonal to the above, the substrate supply position in the A and B directions and the moving position of the stages 9 and 15 in the X and Y directions can be appropriately adjusted. Thus, the TFT substrate 13 and the CF substrate 14 can be arbitrarily aligned in the X and Y directions and positioned at the rotation center of the θ stage 16.
[0029]
Next, the TFT substrate 13 supplied as described above is sucked and held by the X stage 9, and the CF substrate 14 is sucked and held by the θ stage 16. Thereby, the TFT substrate 13 and the CF substrate 14 are arranged in a state of facing each other in the vertical direction (Z-axis direction).
[0030]
Subsequently, the upper plate 6 is guided by the linear guide 8 and lowered by driving the actuator 5, and the X stage 9 is lowered to a position near the θ stage 16 together with the upper plate 6. In this state, the alignment marks M provided at the four corners of each substrate are recognized by the imaging cameras 12 facing each other, and the mark center coordinates are grasped from the recognition result. Then, the X, Y, θ stages 9, 15, 16 are appropriately moved by the drive systems 11, 20, 21 based on the grasped mark center coordinates, so that the mark center position of the TFT substrate 13 and the CF substrate 14 are After aligning the mark center position, the X stage 9 is further lowered and pressed by the driving of the actuator 5 and the driving force, whereby the TFT substrate 13 and the CF substrate 14 are bonded to a sealing material (not shown, for example, an ultraviolet curable adhesive). Pasted through a resin or the like).
[0031]
Thereafter, the X stage 9 is lifted (withdrawn) together with the upper plate 6 by driving the actuator 5 in a state where the vacuum suction of the X stage 9 is released, and then a bonded substrate (including a TFT substrate 13 and a CF substrate 14) 13 + 14) is taken out from the θ stage 16 in the B ′ direction by a substrate transfer device (not shown) and transferred to the next process. The substrate is positioned and bonded in such a procedure.
[0032]
Here, the main feature of the substrate bonding apparatus according to the present embodiment is the configuration of the drive systems 11, 20, and 21 that move the X, Y, and θ stages 9, 15, and 16. Incidentally, the configurations of the drive systems 11 and 20 for moving the X and Y stages 9 and 15 are basically the same including the operation principle thereof, so here the Y-axis drive system 20 and the θ-axis drive system 21 are the same. Only the configuration will be described.
[0033]
3 is a plan view for explaining a substrate positioning mechanism of the substrate bonding apparatus according to the present embodiment, FIG. 4 is a partial sectional view as seen from the direction of arrow D in FIG. 3, and FIG. 5 is an arrow E in FIG. It is the fragmentary sectional view seen from the viewing direction.
[0034]
First, the configuration of the Y-axis drive system 20 will be described with reference to FIGS.
A drive motor 23 is mounted on the base plate 2 via a bracket 22. The motor shaft of the drive motor 23 is connected to a ball screw shaft 25 via a coupling member 24. The ball screw shaft 25 is arranged in a state orthogonal to the moving direction Y of the Y stage 15, that is, parallel to the X direction, and in this state, both ends of the shaft are rotatably supported by the bearing member 26.
[0035]
A ball screw nut 27 is engaged with a screw portion of the ball screw shaft 25. The ball screw nut 27 is inserted and fixed in the housing 28. The housing 28 has a substantially rectangular parallelepiped shape as a whole, and concave fitting grooves 28a and 28b are formed on the lower surface and the side surface facing the Y stage 15, respectively, as shown in FIG.
[0036]
A linear motion guide 29 is incorporated between the housing 28 and the base plate 2. The linear motion guide 29 regulates (guides) the moving direction of the housing 28 in the axial direction of the ball screw shaft 25, and includes a movable element 29a having a built-in bearing and a rail shape for guiding the movement of the movable element 29a. And a stator 29b. Among these, the mover 29a is fixed to the housing 28 with screws or the like while being fitted in the fitting groove 28a on the lower surface of the housing, and the stator 29b is fixed to the upper surface of the base plate 2 with screws.
[0037]
On the other hand, the housing 28 and the Y stage 15 are connected by the following taper guide mechanism. That is, the intermediate member 30 is attached to the side surface of the Y stage 15 on the side facing the ball screw shaft 25 with screws. The intermediate member 30 is formed with a predetermined inclination (for example, about 3 °) with respect to the axial direction (X-axis direction) of the ball screw shaft 25 serving as a drive shaft. On the other hand, the bottom surface of the recess of the fitting groove 28b of the housing 28 is formed in a tapered shape with the same inclination direction and inclination angle as the taper portion 30a. That is, the tapered portion 30a of the intermediate member 30 and the bottom surface of the recessed portion of the fitting groove 28b are formed in parallel to each other when seen in a plan view.
[0038]
A linear motion guide 31 is incorporated between the housing 28 and the intermediate member 30. The linear motion guide 31 includes a mover 31a incorporating a bearing and a rail-shaped stator 31b for guiding the movement of the mover 31a, as described above. The stator 31b is fixed to the tapered portion 31a of the intermediate member 30 with a screw while being fitted to the fitting groove 28b.
[0039]
Further, the two linear motion guides 29 and 31 fitted in the fitting grooves 28a and 28b of the housing 28 are respectively disposed in two planes (XY plane and XZ plane) orthogonal to each other, and in each plane. It arrange | positions so that the axis line which passes through the center of each linear motion guide 29 and 31 may cross | intersect at the center (axial center) Pc of the ball screw shaft 25. FIG.
[0040]
In the Y-axis drive system 20 having the above-described configuration, when the ball screw shaft 25 is rotated by driving the drive motor 23, the ball screw nut 27 moves on the shaft in accordance with the rotation direction and the rotation amount. Is guided by the linear motion guide 29 and moves in the X direction. If it does so, the needle | mover 31a fitted by the fitting groove 28b of the housing 28 side surface will be guided to the stator 31b along the taper part 30a of the intermediate member 30, and will move.
[0041]
At this time, the tapered portion 30 a of the intermediate member 30 has a predetermined inclination with respect to the axial direction X of the ball screw shaft 25, and the moving direction of the housing 28 is regulated by the linear motion guide 29 in the axial direction X of the ball screw shaft 25. Therefore, the movement operation of the housing 28 in the X direction is converted into the movement operation of the Y stage 15 according to the inclination of the tapered portion 30a. Thus, the Y stage 15 can be moved in the Y direction by driving the drive motor 23.
[0042]
Incidentally, if the rotation amount of the ball screw shaft 25 is n and the lead pitch of the screw portion of the ball screw shaft 25 is Lp, the movement amount Lm of the housing 28 in the X direction is “Lm = n · Lp”. If the taper ratio of the tapered portion 30 a is 1 / t, the Y stage 15 moves by “n · Lp / t” in the direction Y orthogonal to the moving direction X of the housing 28.
[0043]
In such a Y-axis drive system 20, the load accompanying the movement of the Y table 15 acts on the ball screw shaft 25 side via the intermediate member 30, the linear motion guide 31, the housing 28, etc., but the load application direction Since the ball screw shaft 25 is arranged in a direction X orthogonal to Y and the load is received by the linear motion guide 29, no load is applied in the axial direction of the ball screw shaft 25. Thereby, the alignment error by the expansion-contraction deformation | transformation of a ball screw shaft like the past can be eliminated.
[0044]
Further, since the Y-stage 15 is moved by utilizing the inclination of the tapered portion 30a of the intermediate member 30 and the engagement groove 28b (concave bottom surface) on the side surface of the housing 28 parallel to the tapered portion 30a, the ball screw shaft 25 is adopted. The load on the side is reduced according to the taper ratio of the tapered portion 30a.
[0045]
Specifically, when the taper ratio of the taper portion 30a is 1 / t and the alignment load acting on the ball screw shaft 25 side as the Y stage 15 moves is Fa, the load Fb actually acting on the ball screw shaft 25 is “ Fb = Fa / t ″, that is, 1 / t. Further, the rigidity of the shaft itself can be increased by t times compared to the case where the same ball screw shaft as that of the conventional system is used. Furthermore, since the torque can be improved without using a reduction gear having problems such as lost motion and backlash, it is possible to improve positioning accuracy by increasing rigidity.
[0046]
In addition, a fitting groove 28a is formed on the lower surface of the housing 28, and the moving element 29a of the linear guide 29 is fitted and fixed in the fitting groove 28a, so that it moves with a load (thrust force) applied to the linear guide 29. Since the child 29a is considered not to be deformed, the housing 28 can be moved accurately and smoothly over a long period of time.
[0047]
Next, the configuration of the θ-axis drive system 21 will be described with reference to FIGS. 3 and 5.
A drive motor 33 is mounted on the Y stage 15 via a bracket 32. A ball screw shaft 35 is connected to the motor shaft of the drive motor 33 via a coupling member 34. The ball screw shaft 35 is arranged in a state substantially orthogonal to the moving direction (rotation direction) θ of the θ stage 16, that is, parallel to the Y direction, and in this state, both ends of the shaft are rotatably supported by the bearing members 36. .
[0048]
A ball screw nut 37 is engaged with a screw portion of the ball screw shaft 35. The ball screw nut 37 is inserted and fixed in the housing 38. The housing 38 is substantially T-shaped in a plan view, and has an engaging portion 38 a integrally extending to a position below the θ stage 16. Further, a concave fitting groove 38b is formed on the lower surface of the housing 38 as shown in FIG.
[0049]
A linear motion guide 39 is incorporated between the housing 38 and the Y stage 15. The linear motion guide 39 regulates (guides) the moving direction of the housing 38 in the axial direction of the ball screw shaft 35, and includes a movable element 39a incorporating a bearing, and a rail shape that guides the movement of the movable element 39a. And a stator 39b. Among these, the mover 39 a is fixed to the housing 38 with a screw or the like in a state of being fitted in the fitting groove 38 b on the lower surface of the housing 38, and the stator 39 b is fixed to the upper surface of the Y stage 15 with a screw. Further, the linear motion guide 39 is disposed such that an axis passing through the center thereof passes through the center (axial core) Pc of the ball screw shaft 35.
[0050]
On the other hand, the housing 38 and the θ stage 16 are connected by the following taper guide mechanism. In other words, a concave groove-shaped taper portion 38 c is formed on the lower surface of the engaging portion 38 a of the housing 38. The tapered portion 38c is formed to have a predetermined inclination (for example, about 3 °) with respect to the axial direction (Y-axis direction) of the ball screw shaft 35 serving as a drive shaft.
[0051]
On the other hand, a swinging member 40 having a substantially L shape in plan view is disposed in the vicinity of the housing 38. A bearing member 41 is incorporated in an intermediate portion (corner portion) of the swing member 40. The bearing member 41 is fitted to a support shaft 42 erected on the Y stage 15, whereby the swing member 40 is supported so as to be swingable about the support shaft 42.
[0052]
Cam followers 43 and 44 are attached to both ends of the swing member 40, respectively. Of these, one cam follower 43 is engaged with the tapered portion 38c of the engaging portion 38a, and the other cam follower 44 is sandwiched in the Y-axis direction by a receiving member 45 fixed to the lower surface of the θ stage 16 by screws. Is engaged.
[0053]
In the θ-axis drive system 21 configured as described above, when the ball screw shaft 35 is rotated by driving of the drive motor 33, the ball screw nut 37 moves on the shaft according to the rotation direction and the rotation amount, and the housing 38 is integrated therewith. Is guided in the linear motion guide 39 and moves in the Y direction. At this time, the tapered portion 38c of the housing 38 has a predetermined inclination with respect to the axial direction Y of the ball screw shaft 35, and the moving direction of the housing 38 is regulated by the linear motion guide 39 in the axial direction Y of the ball screw shaft 35. Therefore, the cam follower 43 engaged with the engaging portion 38a of the housing 38 is subjected to a force for displacing the cam follower 43 in the X direction.
[0054]
Then, the swinging member 40 swings around the support shaft 42 in response to the X-direction displacement force acting on the cam follower 43. At this time, since the other cam follower 44 of the swing member 40 is engaged with the receiving member 45, the θ stage 16 is guided to the bearing member 19 in a manner interlocked with the swing operation of the swing member 40, and θ Move (turn) in the direction. That is, the movement operation of the housing 38 in the Y direction is converted into the movement operation (rotation operation) of the θ stage 16 according to the inclination of the tapered portion 38c. Accordingly, the θ stage 16 can be moved (rotated) in the θ direction by driving the drive motor 33.
[0055]
In such a θ-axis drive system 21, a load accompanying the movement of the θ stage 16 acts on the ball screw shaft 35 side via the receiving member 45, the swinging member 40, the housing 38, etc., but the direction in which the load is applied Since the ball screw shaft 35 is disposed in a direction Y orthogonal to X and the load is received by the linear motion guide 39, no load is applied in the axial direction of the ball screw shaft 35. Thereby, the alignment error by the expansion-contraction deformation | transformation of a ball screw shaft like the past can be eliminated.
[0056]
Further, since a mechanical configuration is employed in which the θ stage 16 is moved (rotated) using the inclination of the tapered portion 38c of the housing 38, the ball screw shaft 35 is moved to the side as in the case of the Y-axis drive system 20 described above. Thus, the rigidity of the shaft itself can be increased and the positioning accuracy can be improved by increasing the rigidity.
[0057]
In addition, a fitting groove 38b is formed on the lower surface of the housing 38, and a moving element 39a of the linear guide 39 is fitted and fixed in the fitting groove 38b, so that it moves with a load (thrust force) applied to the linear guide 39. Since it is considered that the child 39a is not deformed, the housing 38 can be moved accurately and smoothly over a long period of time.
[0058]
In addition, in the substrate bonding apparatus according to the present embodiment, sufficient rigidity can be obtained without increasing the cross-sectional area of the ball screw shaft, and among the X, Y, θ stages 9, 15, 16 The X stage 9 and Y stage 15 are completely separated in the vertical direction (Z-axis direction), and the TFT substrate 13 is held on the X stage 9 side while the CF substrate 14 is held on the Y stage 15 side. Therefore, the height of the pressure side stage (X stage 9) and the height of the pressure side stage (Y stage 15, θ stage 16) can be kept low. Thereby, the bending moment by Abbe's offset can be made smaller than before, and positioning accuracy can be improved.
[0059]
In the Y-axis drive system 20, the center Pc of the ball screw shaft 25 is disposed at the intersection of the central axes of the two linear motion guides 29 and 31 fitted in the housing 28. Since the center axis of the moving guide 39 is disposed so as to pass through the center (axial center) Pc of the ball screw shaft 35, the Abbe offset can be reduced as much as possible to suppress the deformation moment force.
[0060]
Furthermore, since no compression spring or the like is used in any of the X, Y, and θ axis drive systems 11, 20, and 21, high-accuracy positioning of the substrate and downsizing of the drive system can be realized simultaneously. In addition, the movement operation of the housing (moving member) by the ball screw is converted into a minute movement operation of each stage by using the taper portions 30a and 38b in the taper guide mechanism, respectively. It does not depend so much on processing accuracy, and positioning on the order of submicrons is facilitated.
[0061]
【The invention's effect】
As described above, according to the substrate positioning apparatus according to the present invention, when the substrate to be processed is positioned in a predetermined direction, the load acting on the drive shaft for moving the stage is orthogonal to the axial direction of the drive shaft. Since the load is reduced by the taper part of the taper guide mechanism, the accuracy error due to deformation of the drive shaft is minimized. It becomes possible to position the substrate to be processed with high accuracy. Further, in a substrate bonding apparatus using such a substrate positioning apparatus, in particular, a substrate bonding apparatus for bonding two substrates for a liquid crystal display panel (TFT substrate, CF substrate), the pixel position of each substrate is accurately set. Positioned and displayed image Goods The quality can be improved.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a substrate bonding apparatus according to an embodiment of the present invention.
FIG. 2 is a side view showing a substrate bonding apparatus according to an embodiment of the present invention.
FIG. 3 is a plan view for explaining a substrate positioning mechanism according to the embodiment of the present invention.
4 is a partial cross-sectional view seen from the direction of arrow D in FIG.
5 is a partial cross-sectional view seen from the direction of arrow E in FIG.
FIG. 6 is a perspective view showing a conventional substrate bonding apparatus.
FIG. 7 is a diagram illustrating a substrate positioning mechanism in a conventional substrate bonding apparatus.
FIG. 8 is a diagram for explaining another conventional substrate positioning mechanism.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 9 ... X stage, 11 ... X axis drive system, 13 ... TFT substrate (substrate to be processed), 14 ... CF substrate (substrate to be processed), 15 ... Y stage, 16 ... θ stage, 20 ... Y axis drive system, 21 ... θ axis drive system, 25, 35 ... Ball screw shaft, 27, 37 ... Ball screw nut, 28, 38 ... Housing, 30 ... Intermediate member, 30a, 38c ... Tapered part, 29, 31, 39 ... Linear motion guide, 40 ... Oscillating member, 42 ... support shaft, 43,44 ... cam follower, 45 ... receiving member

Claims (2)

A stage that is movably supported in a predetermined direction and that positions the substrate to be processed in the predetermined direction;
A drive shaft disposed in a direction perpendicular to the application direction of the load accompanying the movement of the stage;
A moving member engaged with the drive shaft and moved by driving the drive shaft, the movement direction of which is regulated in the axial direction of the drive shaft by a first guide member;
The moving member and the stage are connected to each other, and a tapered portion having a predetermined inclination with respect to the axial direction of the driving shaft and a second guide member are connected to the connecting portion, and the driving shaft drives the driving member. A taper guide mechanism that converts the moving operation of the moving member into the moving operation of the stage according to the inclination of the tapered portion;
The first guide member and the second guide member are each constituted by a linear guide, and are arranged in two planes orthogonal to each other,
The drive from the center axis in the width direction of the linear guide constituting the second guide member and the central axis extending in the direction of the drive shaft from the center in the width direction of the linear guide constituting the first guide member A substrate positioning apparatus in which an axis of the drive shaft is arranged at an intersection where a central axis extending in the direction of the axis intersects. A stage that is movably supported in a predetermined direction and that positions the substrate to be processed in the predetermined direction;
A drive shaft disposed in a direction perpendicular to the application direction of the load accompanying the movement of the stage;
A moving member engaged with the drive shaft and moved by driving the drive shaft, the movement direction of which is regulated in the axial direction of the drive shaft by a first guide member;
The moving member and the stage are connected to each other, and a tapered portion having a predetermined inclination with respect to the axial direction of the driving shaft and a second guide member are connected to the connecting portion, and the driving shaft drives the driving member. A taper guide mechanism that converts the moving operation of the moving member into the moving operation of the stage according to the inclination of the tapered portion;
The first guide member and the second guide member are each constituted by a linear guide, and are arranged in two planes orthogonal to each other,
The drive from the center axis in the width direction of the linear guide constituting the second guide member and the central axis extending in the direction of the drive shaft from the center in the width direction of the linear guide constituting the first guide member Using the substrate positioning device in which the axis of the drive shaft is arranged at the intersection where the central axis extending in the axis direction intersects,
A substrate bonding apparatus that positions and bonds a pair of substrates to be processed.

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