JP2019019369A - Alignment device and film deposition apparatus - Google Patents

Abstract

An object of the present invention is to improve the reproducibility of relative positional deviation that occurs when the substrate is placed on the mask after an alignment process of the substrate and the mask, and improve the alignment accuracy. SOLUTION: A substrate holding part for holding a substrate includes a pair of receiving claws on which a pair of opposing sides of the substrate are placed, respectively, and a pair of clamp units provided facing the respective receiving claws. The pair of clamping units includes a first clamping unit facing a receiving claw on which one side of a pair of opposed sides of the substrate is placed, and a receiving claw on which the other side is placed. and a second clamp unit facing each other, and the frictional force generated between the first clamping unit and the substrate is smaller than the frictional force generated between the second clamping unit and the substrate. characterized by [Selection drawing] Fig. 7

Description

  The present invention relates to an alignment apparatus and a film forming apparatus including the alignment apparatus.

  In the manufacture of electronic devices such as organic EL elements, a glass substrate (hereinafter simply referred to as a substrate) is held horizontally with the film formation surface facing downward and has an opening corresponding to the pattern of the film formed on the substrate. Film formation using a mask is performed. When film formation is performed with the deposition surface of the substrate facing down, the substrate is supported at the end so as not to interfere with film formation as much as possible, so that the central portion of the substrate is bent under a convex shape by its own weight. Become.

  In order to form a film at a predetermined position of the substrate, relative alignment (alignment) between the substrate and the mask is performed. Specifically, the substrate and the mask are arranged so as not to contact each other, and after the alignment of the substrate alignment mark and the mask alignment mark is performed using the imaging device, the substrate and the mask are brought close to each other, A substrate is placed on the mask. In this state, when the amount of deviation between the alignment mark on the substrate and the alignment mark on the mask falls within a predetermined range, the alignment is completed.

  Patent Document 1 discloses an alignment apparatus in which a substrate pressing portion is placed on a substrate supported by an edge of one main surface which is a film formation surface so as to cover the entire area of the other main surface. It is described that by holding the substrate in this manner, alignment using the mass (gravity or inertia) of the substrate pressing portion can be performed, the phenomenon of the substrate being violated can be avoided, and the displacement of the substrate can be prevented. Has been.

JP 2008-7857 A

  According to Patent Document 1, when the edge of the substrate is pressed by the substrate pressing portion, the amount of deflection of the substrate is reduced by the lever principle, and the alignment marks of the substrate and the mask can be measured simultaneously.

  However, even if the bending of the substrate can be reduced, it cannot be eliminated. Therefore, after the alignment, when the substrate and the mask are brought closer to each other in order to bring the substrate into contact with the mask, the bent central portion first contacts the mask, and then the contact area expands toward the periphery of the central portion. Nearly the entire surface will come into contact. Then, by the restriction by the frictional force generated between the substrate and the mask in the contact area between the substrate and the mask in the central part of the substrate and the restriction by the frictional force generated at the contact part between the receiving claw and the substrate pressing part at the substrate end. The free movement of the substrate is hindered. When the substrate and the mask are brought closer to each other in such a state, the shape of the substrate changes in accordance with the shape of the mask, and a large distortion occurs in the substrate. When the distortion of the substrate increases to some extent, it is eliminated at a location where the binding force is weak, and the relative position between the substrate and the mask is shifted.

  If the magnitude and direction of the relative positional deviation between the substrate and the mask are constant, the alignment can be performed in consideration of the relative positional deviation. However, due to subtle changes in the individuality and the position where the substrate is held, the shape of the flexure varies with each alignment. Patent Document 1 does not consider the bending shape of each substrate, so the direction and size of the relative displacement between the substrate and the mask differ for each alignment, and the alignment taking into account the relative displacement is performed. Have difficulty.

  Accordingly, the present invention aims to improve the reproducibility of the relative positional deviation between the substrate and the mask that occurs when the substrate bent by its own weight is placed on the mask, and to realize highly accurate alignment. To do.

  In order to solve the above-described problem, in the alignment apparatus according to the present invention, the substrate holding unit that holds the substrate is opposed to the pair of receiving claws on which the pair of opposite sides of the substrate are respectively placed, and to the respective receiving claws. A pair of clamp units, and the pair of clamp units includes a first clamp unit facing a receiving claw on which one side of the pair of opposing sides of the substrate is placed; A friction force generated between the first clamp unit and the substrate is configured by a second clamp unit facing the receiving claw on which the other side is placed, and the second clamp unit and the substrate. It is characterized by being smaller than the frictional force generated between the two.

  ADVANTAGE OF THE INVENTION According to this invention, the reproducibility of the relative position shift at the time of mounting a board | substrate on a mask can be improved, and alignment accuracy can be improved.

It is sectional drawing which shows the structure of the film-forming apparatus typically. It is a perspective view which shows one form of an alignment mechanism, and a perspective view of a board | substrate holding unit provided with the clamping mechanism of a board | substrate. FIG. 3 is a perspective view showing an embodiment of a rotary translation mechanism 11. (A) is a perspective view of a substrate holding unit having a substrate clamping mechanism, and (b) and (c) are enlarged views of a portion of the substrate holding unit 8 that holds the substrate. (A) is the figure which looked at the board | substrate 5 of the state currently hold | maintained at the board | substrate holding | maintenance part, (b) is the figure which looked at the mask from the upper surface, (c) is one set of mask marks and board | substrates by the fine camera. It is a figure which imagines the visual field at the time of measuring a mark. It is a flowchart which shows an alignment sequence. It is a figure which shows a mode that the board | substrate 5 is hold | maintained with the alignment apparatus concerning this invention, and a board | substrate is mounted in a mask. (A) is a general view of an organic EL display device, (b) is a diagram showing a cross-sectional structure of one pixel. It is an upper view which shows typically a part of structure of the manufacturing apparatus of an electronic device.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. However, the embodiments described below are merely illustrative of preferred configurations of the present invention, and the scope of the present invention is not limited to these configurations. In the following description, the hardware configuration and software configuration of the apparatus, the processing flow, the manufacturing conditions, the dimensions, the material, the shape, and the like do not limit the scope of the present invention to these unless otherwise specified. .

  The present invention relates to an alignment apparatus and a film forming apparatus that includes the alignment apparatus and forms a thin film on the substrate.

  The present invention is preferably applicable to an apparatus for forming a thin film (material layer) having a desired pattern by vacuum deposition on the surface of a parallel flat glass substrate. As an evaporation material, any material such as an organic material and an inorganic material (metal, metal oxide, etc.) can be selected. The technology of the present invention is specifically applicable to an apparatus for manufacturing an electronic device (for example, an organic EL display device or a thin film solar cell). In particular, an organic EL display device manufacturing apparatus in which a glass substrate is mainly used as a film formation substrate and the size of the substrate is being promoted is one of preferable application examples of the present invention.

(Alignment device and film formation device)
An alignment apparatus according to an embodiment of the present invention and a film forming apparatus including the alignment apparatus will be described with reference to the drawings. When there are a plurality of identical or corresponding members, subscripts such as a and b are given in the drawings, but the subscripts such as a and b are omitted except when referring to specific members. .

  The conceptual diagram of the film-forming apparatus provided with the alignment apparatus concerning this invention is shown in FIG.

  The film forming apparatus includes a film forming chamber 4 having a film forming space 2 for forming a film forming material on the substrate 5, a gate valve 15 for loading / unloading the substrate 5 into / from the film forming chamber 4, a substrate 5 and a mask. 6 is provided with an alignment apparatus 1 that holds the position 6 and performs relative alignment. In the film forming space 2 of the film forming chamber 1, a mechanism for installing a film forming source (evaporation source) 7 including a film forming material is provided. Although FIG. 1 shows a vapor deposition apparatus, the alignment apparatus according to the present invention can also be applied to a film deposition apparatus that uses a film deposition method other than the vapor deposition method, such as a sputtering method or a CVD method.

  The alignment apparatus 1 is mounted on the upper partition wall (top plate) 3 of the film forming chamber 4, and has a positioning mechanism including a driving unit, a substrate holding unit 8, and a mask holding unit 9. The positioning mechanism includes a rotary translation mechanism 11 that is driven in the XYθz direction, a Z lifting base 13, and a Z lifting slider 10 that moves along a Z guide 18 fixed to a side surface of the Z lifting base 13. It is provided outside the chamber 2. By disposing the positioning mechanism including many movable parts outside the film formation space, dust generation in the film formation space can be suppressed.

  A substrate holding shaft 12 is fixed to the Z lift slider 10. The substrate holding shaft 12 is provided across the outside and inside of the film forming chamber 4 through a through hole 16 provided in the upper partition 3 of the film forming chamber 4. And in the film-forming space 2, the substrate holding part 8 is provided under the substrate holding shaft 12, and it is possible to hold | maintain the board | substrate 5 which is a film-forming object.

  The through hole 16 is designed to be sufficiently large with respect to the outer diameter of the substrate holding shaft 12 so that the substrate holding shaft 12 and the upper partition wall 3 do not interfere with each other. The substrate holding shaft 12 passes through the through-hole 16 and is fixed to the Z lifting / lowering slider 10 outside the film forming chamber 4 until the end is fixed to the Z lifting / lowering slider 10 and the upper partition 3. 40. That is, since the substrate holding shaft 12 is covered with a closed space communicating with the film forming chamber 4, the entire substrate holding shaft 12 can be maintained in the same state as the film forming space 2 (for example, a vacuum state). A bellows 40 having flexibility in the Z direction and the XY direction may be used. The resistance force generated when the bellows 40 is displaced by the operation of the alignment apparatus 1 can be sufficiently reduced, and the load at the time of position adjustment can be reduced. The mask holding unit 9 is installed on the surface of the upper partition wall 3 on the side of the film forming space inside the film forming chamber 4 and can hold the mask. A mask 6 widely used in the manufacture of an organic EL panel has a configuration in which a mask foil 6a having an opening corresponding to a film formation pattern is fixed in a state of being stretched on a highly rigid mask frame 6b, The mask 6 is held in a state of small deflection.

  A series of operations of the positioning mechanism, the substrate holding mechanism 8 and the film forming source are controlled by the control unit 50. The control unit 50 can be configured by a computer having a processor, a memory, a storage, an I / O, and the like, for example. In this case, the function of the control unit 270 is realized by the processor executing a program stored in the memory or storage. As the computer, a general-purpose personal computer may be used, or an embedded computer or a PLC (programmable logic controller) may be used. Alternatively, some or all of the functions of the control unit 50 may be configured by a circuit such as an ASIC or FPGA.

  Next, details of the positioning mechanism of the alignment apparatus 1 will be described with reference to FIG.

  FIG. 2 is a perspective view showing an embodiment of the alignment apparatus 1. A guide for guiding the Z lifting / lowering slider 10 in the vertical Z direction includes a plurality of Z guides 18 a to 18 d and is fixed to a side surface of the Z lifting / lowering base 13. A ball screw 20 for transmitting a driving force is disposed at the center of the Z lift slider, and power transmitted from a motor 19 fixed to the Z lift base 13 is transmitted to the Z lift slider 10 via the ball screw 20.

  The motor 19 has a built-in rotary encoder (not shown), and can indirectly measure the Z-direction position of the Z lift slider 10 based on the number of rotations of the encoder. Therefore, if the drive of the motor 19 is controlled based on the measured value by the encoder, the Z lifting slider 10 can be accurately positioned in the Z direction. The elevating mechanism of the Z elevating slider 10 is not limited to the ball screw 20 and the rotary encoder, and a known mechanism such as a combination of a linear motor and a linear encoder can be employed.

  FIG. 3 is a perspective view showing an embodiment of the rotary translation mechanism 11. The Z elevating slider 10 and the Z elevating base 13 are disposed on the rotary translation mechanism 11, and the entire Z elevating base 13 and the Z elevating slider 10 can be driven in the XYθz direction.

  The rotary translation mechanism 11 has a plurality of drive units 21a to 21d. In the configuration of FIG. 3, the drive units 21 a to 21 d are respectively disposed at the four corners of the base, and are disposed in a direction in which the drive units disposed at adjacent corners are rotated 90 degrees around the Z axis.

  Each drive unit 21 includes a motor 41 that generates a driving force. Further, the first guide 22 that slides in the first direction by transmitting the force of the motor 41 via the ball screw 42, and the second that slides in the second direction orthogonal to the first direction in the XY plane. The guide 23 is provided. Furthermore, a rotary bearing 24 that can rotate around the Z-axis is provided. For example, the drive unit 21c has a first guide 22 that slides in the X direction, a second guide 23 that slides in the Y direction orthogonal to the X direction, and a rotary bearing 24. Is transmitted to the first guide 22 via the ball screw 42.

  The motor 41 has a built-in rotary encoder (not shown) and can measure the displacement amount of the first guide 22. In each drive unit 21, the position of the Z lift base 13 in the XYθz direction can be precisely controlled by controlling the drive of the motor 41 by the control unit 50 based on the measured displacement amount of the first guide 22. .

  When the Z elevating base 13 is moved in the + X direction, a force for sliding in the + X direction in each of the drive units 21b and 21c is generated by the motor 41, and the force is transmitted to the Z elevating base 13. Further, when moving in the + Y direction, it is preferable to generate a force to slide in the + Y direction in each of the drive units 21 a and 21 d by the motor 41 and transmit the force to the Z lifting base 13.

  When rotating the Z lift base 13 by + θz (clockwise θz rotation), the drive units 21c and 21b arranged diagonally are used to generate a force necessary to rotate + θz around the Z axis, The force may be transmitted to the Z lifting base 13. Alternatively, the driving unit 21a and 21d may be used to transmit a force necessary for rotation to the Z lifting base 13.

  Next, a detailed configuration of the substrate holding portion 8 of the alignment apparatus 1 according to the present invention will be described with reference to FIG. FIG. 4A is a perspective view of the entire substrate holding portion 8 that holds the rectangular substrate 5 along the long side as viewed from the alignment apparatus 1 side. 4 (b) and 4 (c) are enlarged views of a portion where the substrate holding portion 8 is in contact with the substrate. The state in which the substrate is held without being sandwiched and the substrate is sandwiched and fixed by the clamp 27. State.

  As shown in FIGS. 4A to 4C, the substrate holding portion 8 is fixed to the lower portion of the substrate holding shafts 12a to 12d. The substrate holding unit 8 includes a plurality of receiving claws 26 provided on a holding unit base 25 whose position is controlled by the substrate holding shaft 12 and a plurality of clamps 27 provided to face the receiving claws 26. . FIG. 4 shows only the clamp 27 that presses one side of the substrate 5. However, in the alignment apparatus according to the present invention, the clamp 27 a that presses one side of the rectangular substrate 5 and the other side presses. The shape of the clamp 27b to which is added is different. Specifically, the friction coefficient between the substrate 5 and the clamp 27a is smaller than the friction coefficient between the substrate 5 and the clamp 27b. The effect of such a configuration will be described in detail later.

  The substrate holding shafts 12a to 12d for controlling the position of the holding unit base 25 may be configured to be collectively controlled, or divided into the substrate holding shafts 12a and 12b and the substrate holding shafts 12c and 12d. It may be configured to be controlled.

  The clamp 27 is a member that contacts the second main surface opposite to the first main surface of the substrate 5 and presses the substrate 5 toward the receiving claw 26 side. By sandwiching the edge of the substrate 5 between the receiving claw 26 and the clamp 27, the position of the substrate can be fixed and the substrate can be held in a state where the deflection of the substrate is reduced.

  Each of the clamps 27 may be driven up and down by a drive mechanism provided individually. Here, a plurality of clamps 27 are provided as one unit for each holding unit base 25 and each unit is driven by a drive mechanism. Will be described. A clamp unit 28 including a plurality of clamps 27 is fixed to a clamp slider 32, and the clamp slider 32 is supported by a linear bush 39 disposed between the holding part base 25 of the substrate holding part 8 and the holding part upper plate 35. Guided in the Z direction. The clamp slider 32 is fixed to the Z lift slider 10 via a drive shaft 34 that penetrates the upper partition 3. The clamp slider 32 is driven in the Z direction by the force of the electric cylinder 36 transmitted through the drive shaft 34.

  When the clamp 27 descends and the clamp 27 comes into contact with the surface of the substrate 5 mounted on the receiving claw 26, the substrate 5 is fixed between the receiving claw 26 and the clamp 27, as shown in FIG. Become. In order to apply a constant load to the substrate 5 by the clamp 27, a spring 29 for generating a holding force (load) is provided on the upper portion of the clamp 27. A rod 31 exists between the clamp 27 and the spring 29, and the clamp 27 is guided in the Z direction. The total length of the spring 29 can be adjusted by changing the gap L with the load adjusting screw 30. Therefore, the pressure generated in the clamp 27 can be freely adjusted by the amount of pressing of the spring 29. In addition, if this press is about several N to several tens of N, the substrate 5 can be pressed with a load larger than the weight of the substrate 5, and the substrate can be prevented from shifting during alignment.

  According to the configuration of the clamp unit 28 and the substrate holding unit 8 described above, the alignment device 1 can move in the XYθz direction and the Z direction while holding the substrate 5 with a constant load.

  The mask frame 6b is provided with a plurality of grooves for avoiding interference with the receiving claws 26 when the substrate 5 is placed on the mask 6a. If the clearance between the groove and the receiving claw 26 is set to several millimeters, it is possible to avoid the mask frame 6b and the receiving claw 26 from colliding with each other even if the receiving claw 26 further descends after the substrate 5 is placed. it can.

  Next, an image pickup apparatus for simultaneously measuring the position of the substrate 5 and the mask foil 6a, that is, the position of each alignment mark will be described. In FIG. 1, an imaging device 14 for measuring the positions of the alignment mark (mask mark) on the mask 6 and the alignment mark (substrate mark) on the substrate 5 is disposed on the outer surface of the upper partition 3. . In the upper partition 3, a through hole and a window glass 17 are provided on the optical axis of the imaging device so that the imaging device 14 can measure the position of the alignment mark in the film forming chamber 2. Furthermore, illumination (not shown) is provided inside or in the vicinity of the imaging device 14, and light is irradiated in the vicinity of the substrate mark and / or the mask mark, thereby enabling accurate mark image measurement.

  A method for measuring the positions of the substrate mark 37 and the mask mark 38 using the imaging device 14 will be described with reference to FIGS.

  FIG. 5A is a top view of the substrate 5 held by the substrate holding unit 8. On the substrate 5, substrate marks 37a to 37d that can be measured by the imaging device 14 are formed at four corners of the substrate. The substrate marks 37a to 37d are simultaneously measured by the four imaging devices 14, and the translation amount and the rotation amount of the substrate 5 with respect to the reference position are calculated from the positional relationship of the four points that are the center positions of the substrate marks. Position information can be acquired. The reference position is an arbitrary position set in advance.

  FIG. 5B is a view of the mask 6 as viewed from above. Mask marks 38a to 38d that can be measured by the imaging device are formed at the four corners of the mask foil 6a. The mask marks 38a to 38d are simultaneously measured by the four imaging devices 14a to 14d, and the translation amount, the rotation amount, and the like of the mask 6 are calculated from the positional relationship of the four points that are the center positions of the mask marks, and the mask positions 38a to 38d are calculated. Mask position information can be acquired.

  FIG. 5C is a diagram illustrating the visual field 43 when the imaging device 14 measures a set of mask marks 38 and substrate marks 37. In the field of view 43 of the imaging device 14, the substrate mark 37 and the mask mark 38 can be measured simultaneously, and the relative positions of the mark centers can be measured. The mark center coordinates can be obtained by using an image processing device (not shown) for an image obtained by measurement by the imaging device 14. In addition, although □ and ○ are shown as the shapes of the mask mark 38 and the substrate mark 37, the shape is not limited to this, and a shape having a target property that can easily calculate the center position, such as x or a cross, can be used.

  When high-precision alignment is required, a high-power CCD camera (also referred to as a fine camera) having a high resolution on the order of several μm is used as the imaging device 14. Since such a high-power CCD camera has a narrow field of view of several millimeters, if the deviation of the state in which the substrate 5 is placed on the claw 26 is large, the substrate mark 37 is out of the field of view and measurement is impossible. Therefore, it is preferable that a low-magnification CCD camera (also referred to as a rough camera) having a wide field of view is provided together with the high-magnification CCD camera as the imaging device 14. After performing rough alignment using a rough camera so that the mask mark 38 and the substrate mark 37 are simultaneously within the field of view of the high-power CCD camera, position measurement can be performed with high accuracy using the high-power CCD camera.

  The relative position information of the mask 6 and the substrate 5 can be acquired from the position information of the mask 6 and the position information of the substrate 5 acquired by the imaging device 14. This relative position information is fed back to the control unit 50 of the alignment apparatus, and the drive amounts of the elevating slider 10, the rotary translation mechanism 11, and the substrate holding unit 8 are controlled. By using a high magnification CCD camera as the imaging device 14, the relative position of the mask 6 and the substrate 5 can be adjusted with an accuracy of several μm.

  After the alignment of the mask 6 and the substrate 5 is completed, vapor of the film forming material may be discharged from the vapor deposition source 7 disposed in the film forming space 2 to start the film forming process.

(Alignment method)
An alignment method using the alignment apparatus according to the present invention will be described with reference to FIG. FIG. 6 is a flowchart showing an alignment sequence according to the present invention when a high-power CCD camera and a low-power CCD camera are installed as the imaging device 14. It is assumed that a mask is set in advance in the mask holding unit.

  First, the substrate 5 is loaded into the robot hand (not shown) from the gate valve 15 and loaded, and placed on the receiving claw 26 so that the first main surface, which is the film formation surface, is in contact (S101).

  When the substrate 5 is placed on the receiving claw 26, the force generated from the electric cylinder 36 is transmitted to the clamp slider 32 via the drive shaft 34, and the clamp slider 32 is driven in the Z direction. Then, the clamp unit 28 attached to the clamp slider 32 descends and comes into contact with the substrate 5, and the substrate 5 is sandwiched (clamped) between the receiving claws 26 and held (S102).

  Next, the substrate mark 37 is measured with a rough camera, and the position information of the substrate 5 placed on the receiving claw 26 is acquired. If the initial placement position is so shifted that it cannot be adjusted to a position where the substrate mark 37 can be accommodated within the field of view of the fine camera, use the robot hand until the substrate can be adjusted to a position within the field of view of the fine camera. Put 5 again.

  The substrate mark 37 of the substrate 5 and the mask mark 38 of the mask 6 are simultaneously detected by the rough camera, and the relative position information of the substrate 5 and the mask 6 is acquired (S103). The relative position information here is specifically the distance between the center positions of the substrate mark 37 and the mask mark 38 and the direction of displacement. In the present invention, since the substrate 5 is clamped to realize a state where the bending of the substrate is improved, it is possible to measure the mask mark together with the substrate mark at the edge of the substrate where the substrate mask is provided. It becomes.

  Based on the obtained relative position information of the substrate 5 and the mask 6, the relative position of the substrate 5 and the mask 6 is adjusted (aligned). As described above, the positioning mechanism provided in the alignment apparatus 1 is driven based on the relative position information, and the substrate 5 is moved in the XYθz direction and the Z direction to adjust the position (S104). The process of S103-S104 is called rough alignment with respect to the fine alignment based on the relative position information obtained using the fine camera performed later. Rough alignment is alignment for placing a substrate mark and a mask mark within the field of view of a fine camera.

  If the substrate 5 is large, even if it is clamped, it is bent several mm due to its own weight. In positioning, the mask 5 and the substrate 5 are in contact with each other and rubbed against each other, so that the surface of the substrate 5 or the already formed film pattern is not damaged. Hold at a certain height (rough alignment height).

  If the position of the substrate 5 can be adjusted until the relative position of the substrate 5 and the mask 6 falls within a predetermined range, the substrate is moved until the focus of the fine camera 14 is adjusted to a height that matches the substrate mark 37 (fine alignment height). 5 is brought close to the mask 6 (S105). In addition, since it is necessary to move the board | substrate 5 relatively with respect to the mask 6 also in fine alignment height, it is necessary to set fine alignment height to such an extent that the board | substrate 5 and the mask 6 do not contact. .

  By performing rough alignment in advance in S103 to S104, it is possible to acquire a fine camera image in which the substrate mark 37 and the mask mark 38 are within the same field of view by the fine camera. The center position of the substrate mark 37 and the mask mark 38 can be detected from the acquired fine camera image, and the relative position information can be acquired with an accuracy of several μm (S106).

  The distance between the center positions of the substrate mark 37 and the mask mark 38 included in the acquired relative position information, that is, the relative position deviation amount is compared with a preset threshold value (S107). If the amount of relative position deviation exceeds the threshold, the substrate 5 is raised to the rough alignment height, and S103 to S106 are performed again. The threshold value is set on the order of several μm, which can achieve the required alignment accuracy between the substrate 5 and the mask 6.

  If it is confirmed in S107 that the distance between the center positions of the substrate mark 37 and the mask mark 38 is equal to or smaller than the threshold value, the substrate 5 is brought closer to the mask 6 (S108).

  When the substrate 5 and the mask 6 start to contact, the movement of the substrate 5 is restricted by a large frictional force generated between the substrate 5 and the mask 6 at the contact portion, and the relative position when the substrate 5 and the mask 6 start to contact each other. Is maintained.

  In the alignment apparatus of the present invention, the frictional force between one clamp unit 28a and the substrate 5 out of the pair of clamp units 28 that apply pressure to the pair of long sides of the substrate causes the other clamp unit 28b and the substrate 5 to It is smaller than the friction force between. Specifically, the frictional force between the plurality of clamps 27a included in the clamp unit 28a and the substrate 5 is smaller than the frictional force between the plurality of clamps 27b included in the clamp unit 28b and the substrate 5. Yes. Accordingly, the distortion of the substrate 5 caused by the lowering of the holding portion base 25 is released as needed on the clamp unit 28a side where the frictional force, that is, the binding force is weak, and the position of the substrate 5 is shifted to the clamp unit 28a side.

  As described above, according to the present invention, the deviation from the relative position, which occurs when the substrate 5 is placed on the mask 6, can always occur in a certain holding direction. It is possible to determine the relative position in consideration of the positional deviation that occurs when placing it on the surface. As a result, the number of alignment operations can be reduced.

  The plurality of clamps 27a and the plurality of clamps 27b preferably have the same structure as each other, but the present invention is not limited to this as long as the shift amount and the shift direction from the relative position can be reproduced.

  When the holder base 25 is lowered to a position where the clamp surface of the clamp unit 28 is lower than the upper surface of the mask frame 6b, the substrate 5 can be placed on the mask 6 from the substrate holder 8 ( S109).

  When the placement of the substrate 5 on the mask 6 is completed, the substrate mark 37 and the mask mark 38 are imaged by the fine camera, and the relative position information between the substrate 5 and the mask 6 is acquired (S110). The acquisition method of relative position information is the same as that of S106.

  It is confirmed whether or not the displacement amount of the relative position is equal to or less than the threshold value (S111). If the displacement amount is equal to or less than the threshold value, the alignment sequence is completed. If the amount of relative position deviation exceeds the threshold value in S111, the alignment sequence is performed again. Specifically, the receiving claws 26 of the clamp units 28a and 28b are raised to the height of the mask frame 6b, and the clamp 27 is lowered when the substrate 5 is placed on the substrate holding portion from above the mask. The substrate is clamped. And the board | substrate 5 is raised to rough alignment height, the process of S103-S111 is performed, and alignment with the board | substrate 5 and the mask 6 is implemented again. The threshold value of the deviation amount in S111 may be determined according to the accuracy required for film formation.

  FIG. 7 illustrates an alignment apparatus according to an embodiment of the present invention and a shift of the substrate 5 caused by an alignment operation using the alignment apparatus. FIGS. 7A to 7D are views of the alignment device viewed from a direction parallel to the long side of the substrate 5. In the drawing, a clamp unit 28a (first clamp unit) facing the receiving claw 26a on which one of the opposing long sides of the substrate 5 is placed is represented by one clamp 27a included in the clamp unit 28a. ing. Similarly, a clamp unit 28b (second clamp unit) facing the receiving claw 26b on which the other side of the long sides facing the substrate 5 is placed is represented by one clamp 27b included in the clamp unit 28b. ing.

  FIG. 7A corresponds to the state in which the amount of positional deviation between the substrate 5 and the mask 6 is equal to or less than the threshold value in S107 of FIG. In the alignment apparatus of the present embodiment, the clamp 27a and the clamp 27b have different shapes. The clamp 27a has a hemispherical shape in the portion that applies pressure to the substrate 5, and has a structure with a small contact area because it makes point contact with the substrate 5. On the other hand, the portion of the clamp 27b that presses against the substrate 5 has a flat shape and is in surface contact with the substrate 5, so that the contact area is sufficiently larger than that of the clamp 27a.

  If the materials of the members in contact with the substrates of the clamps 27a and 27b are the same and the surface of the substrate 5 in contact with the clamps 27a and 27b is in the same state, the frictional force between the substrate 5 and the clamps 27a is And the frictional force between the clamp 27a and the clamp 27a.

  FIG. 7B shows a state in which the substrate 5 is brought close to the mask 6 in a state where the substrate 5 is pressed by the clamps 27a and 27b (corresponding to S108 in FIG. 6). Since the central portion of the substrate 5 is bent by its own weight, the substrate 5 and the central portion first start contact. At this time, the reaction force due to contact is transmitted to the clamps 27a and 27b. As described above, the frictional force Fa between the substrate 5 and the clamp 27a is smaller than the frictional force Fb between the substrate 5 and the clamp 27b. The substrate 5 is shifted to the 27a side (the direction of the white arrow).

  FIG. 7C shows a state where the substrate 5 is placed on the mask 6. The substrate 5 is fully extended following the mask 6 and corresponds to the state of S109 in FIG. Then, the pressing of the clamp is released as shown in FIG. 7D, and the entire substrate holding portion 8 is lowered, whereby the placement of the substrate 5 on the mask 6 from the substrate holding portion 8 is completed. Thereafter, it is confirmed that the relative position between the substrate and the mask is equal to or smaller than the threshold value (corresponding to S111 in FIG. 6), and the alignment operation is completed. If the apparatus position exceeds the threshold value, the process returns to S103 and rough alignment and fine alignment are performed again.

  As described above, in the conventional configuration, the clamp that applies pressure to the substrate 5 has the same shape. Therefore, the position at which the distortion is eliminated differs for each alignment, and the direction and size of the relative positional deviation between the substrate and the mask. Was not constant. As a result, the relative displacement when the substrate 5 is placed on the mask 6 cannot be predicted, the alignment accuracy between the substrate 5 and the mask 6 is deteriorated, and a long time is required for alignment.

  However, by applying the present invention, since the relative positional deviation when the substrate 5 is placed on the disc 6 is controlled in a fixed direction, the reproducibility of the relative positional deviation is improved, and the positions of the substrate 5 and the mask 6 are increased. The alignment accuracy is improved and the time required for alignment can be shortened.

  In the embodiment shown in FIG. 7, the shape of the portion where the clamp 27 presses the substrate is made hemispherical with the clamp 27a and planar with the clamp 27b. Although it was made possible, this shape is not limited. Any shape may be used as long as the magnitude relationship of the frictional force generated between the clamp 27a and the clamp 27b with the substrate 5 can be realized. For example, a portion where the clamp 27a presses the substrate is cut into a groove so that the contact area has a small frictional force, and the portion where the clamp 27a presses the substrate is saw-shaped or embossed to increase contact with the substrate. A shape with a large frictional force may be used. The method for realizing the magnitude relationship of the frictional force is not limited to the shape of the pressing portion of the clamp 27. For example, the clamp 27a and the clamp 27b have the same shape, and the clamp 27a, the substrate 5 and the contact portion are provided with a fluorine-based resin or the like for reducing the friction coefficient, and the friction force is varied depending on the material. Also good.

(Device manufacturing)
When the alignment between the substrate 5 and the mask 6 using the alignment apparatus 1 according to the present invention is completed, a device manufacturing process including a film forming process is performed. Here, a method for manufacturing an organic EL device will be described as an example of a method for manufacturing an electronic device using the film forming apparatus of the present embodiment.

  First, the organic EL panel to be manufactured will be described. FIG. 8A shows an overall view of the organic EL display device 60, and FIG. 8B shows a cross-sectional structure of one pixel.

  As shown in FIG. 8A, in the display area 61 of the organic EL panel 60, a plurality of pixels 62 including a plurality of light emitting elements are arranged in a matrix. Although details will be described later, each of the light-emitting elements has a structure including an organic layer sandwiched between a pair of electrodes. Note that the pixel here refers to a minimum unit capable of displaying a desired color in the display area 61.

  In the case of the organic EL panel according to this example, the pixel 62 includes a combination of the first light emitting element 62R, the second light emitting element 62G, and the third light emitting element 62B that emit different light. In general, the pixel 62 often includes a red light emitting element, a green light emitting element, and a blue light emitting element. However, the pixel 62 may include a yellow light emitting element, a cyan light emitting element, and a white light emitting element. Absent.

  FIG. 8B is a schematic partial cross-sectional view taken along the line AB of FIG. The pixel 62 includes a first electrode (anode) 64, a hole transport layer 65, one of the light emitting layers 66 </ b> R, 66 </ b> G, and 66 </ b> B, an electron transport layer 67, and a second electrode (cathode) 68 on a substrate 63. And an organic EL element. Among these, the hole transport layer 65, the light emitting layers 66R, 66G, and 66B, and the electron transport layer 67 correspond to the organic layer. In the present embodiment, the light emitting layer 66R is an organic EL layer that emits red, the light emitting layer 66G is an organic EL layer that emits green, and the light emitting layer 66B is an organic EL layer that emits blue. The light emitting layers 66R, 66G, and 66B are formed in patterns corresponding to light emitting elements that emit red, green, and blue (sometimes referred to as organic EL elements). The first electrode 64 is formed separately for each light emitting element. The hole transport layer 65, the electron transport layer 67, and the second electrode 68 may be formed in common with the plurality of light emitting elements 62, or may be formed for each light emitting element. Although the first electrode 64 is an anode and the second electrode is a cathode here, the first electrode 64 may be a cathode and the second electrode may be an anode. In that case, the stacking order of the hole transport layer 65 and the electron transport layer 67 may be reversed.

  In order to prevent the first electrode 64 and the second electrode 68 from being short-circuited by foreign matter, an insulating layer 69 is provided between the first electrodes 64. Furthermore, since the organic EL layer is deteriorated by moisture and oxygen, a protective layer 70 for protecting the organic EL element from moisture and oxygen is provided.

  In order to form the organic EL layer in units of light emitting elements, a method of forming a film through a mask is used. In recent years, display devices have been improved in definition, and a mask having an opening width of several tens of μm is used for forming an organic EL layer. For film formation using such a mask, a film formation apparatus (vacuum evaporation apparatus) including the alignment apparatus 1 according to the present invention is preferably used.

  Next, an example of an organic EL panel manufacturing method will be specifically described.

  First, a circuit (not shown) for driving the organic EL panel and a substrate 63 on which the first electrode 64 is formed are prepared.

  An acrylic resin is formed by spin coating on the substrate 63 on which the first electrode 64 is formed, and the acrylic resin is patterned by a lithography method so that an opening is formed in a portion where the first electrode 64 is formed. 69 is formed. This opening corresponds to a light emitting region where the light emitting element actually emits light.

  The substrate 63 patterned with the insulating layer 69 is carried into the first film formation apparatus, the substrate is held by the substrate holding unit, and the hole transport layer 65 is a common layer on the first electrode 64 in the display region. As a film formation. The hole transport layer 65 is formed by vacuum deposition. Actually, since the hole transport layer 65 is formed in a size larger than the display region 61, a high-definition mask is not necessary.

  Next, the substrate 63 on which the hole transport layer 65 is formed is carried into the second film forming apparatus and held by the substrate holding unit. The substrate and the mask are aligned, the substrate is placed on the mask, and the light emitting layer 66R that emits red is formed on the portion of the substrate 63 where the element that emits red is disposed. According to this example, the relative positions of the mask and the substrate can be accurately aligned and overlapped, so that highly accurate film formation can be performed.

  Similarly to the formation of the light emitting layer 66R, the light emitting layer 66G that emits green is formed by the third film forming apparatus, and the light emitting layer 66B that emits blue is formed by the fourth film forming apparatus. After the formation of the light emitting layers 66R, 66G, and 66B is completed, the electron transport layer 67 is formed on the entire display region 61 by the fifth film formation apparatus. The electron transport layer 67 is formed as a layer common to the three-color light emitting layers 66R, 66G, and 66B.

  The substrate on which the electron transport layer 67 has been formed is moved to the sputtering apparatus, the second electrode 68 is formed, and then the protective layer 70 is formed by moving to the plasma CVD apparatus, whereby the organic EL display device 60 is completed. To do.

  From when the substrate 63 with the insulating layer 69 patterned is carried into the film formation apparatus until the film formation of the protective layer 70 is completed, if the light emitting layer made of an organic EL material is exposed to an atmosphere containing moisture or oxygen, There is a risk of deterioration due to moisture and oxygen. Therefore, in this example, the carrying-in / out of the substrate between the film forming apparatuses is performed in a vacuum atmosphere or an inert gas atmosphere.

  In the organic EL display device thus obtained, a light emitting layer is accurately formed for each light emitting element. Therefore, if the manufacturing method is used, it is possible to suppress the occurrence of defects in the organic EL display device due to the displacement of the light emitting layer.

(Electronic device manufacturing equipment)
FIG. 9 shows an example of an electronic device manufacturing apparatus. As shown in FIG. 9, a plurality of film forming apparatuses 111 to 114 and a transfer chamber 110 are included. In the transfer chamber 110, a transfer robot 119 that holds and transfers the substrate 5 is provided. The transfer robot 119 is, for example, a robot having a structure in which a robot hand for holding a substrate is attached to an articulated arm, and carries the substrate 5 into and out of each film forming chamber. The manufacturing apparatus may include four or more film forming apparatuses, and may further be connected to processing chambers for performing other processes. As each film forming apparatus, the film forming apparatus according to the present invention can be preferably used. A series of operations of the film forming source is controlled by a control unit (not shown), but the control unit may be provided for each film forming apparatus, or one control unit may control a plurality of film forming apparatuses. .

  A series of film forming processes such as delivery of the substrate 5 to and from the transfer robot 119, adjustment of the relative position between the substrate 5 and the mask (alignment), fixation of the substrate 5 on the mask, and film formation are automatically performed by a control unit (not shown). Can be done. Each of the film forming apparatuses has almost the same basic configuration (particularly, a configuration related to substrate transport and alignment), although there are differences in fine points such as differences in film forming sources and masks.

  When manufacturing the organic EL panel mentioned above as an electronic device, the board | substrate with which the hole transport layer was formed is carried in into the conveyance chamber 110. FIG. In each of the film formation apparatuses 111 to 115, a red light emitting layer, a green light emitting layer, a blue light emitting layer, and an electron transport layer may be sequentially formed.

  As described above, when the alignment apparatus 1 and the film forming apparatus having the receiving claws 26 according to the present invention are used, it is possible to prevent the substrate 5 from being broken during the alignment process when manufacturing an electronic device or the like. it can. As a result, the yield of the product can be improved and a reduction in manufacturing cost can be expected.

DESCRIPTION OF SYMBOLS 5 Board | substrate 6 Mask 8 Board | substrate holding | maintenance part 9 Mask holding | maintenance part 10 Z raising / lowering slider 11 Rotation translation mechanism 12 Substrate holding shaft 13 Z Elevating base 25 Holding base 26 Receiving claw 27 Clamp 28 Clamp unit 32 Clamp slider 34 Drive shaft 36 Electric cylinder

Claims (19)

The substrate holding unit for holding the substrate has a pair of receiving claws on which a pair of opposite sides of the substrate are respectively placed, and a pair of clamp units facing the receiving claws,
The pair of clamp units includes a first clamp unit that faces a receiving claw on which one side of the pair of opposite sides of the substrate is placed, and a first clamping unit that faces the receiving claw on which the other side is placed. 2 clamp units,
The frictional force generated between the first clamp unit and the substrate is
An alignment apparatus characterized by being smaller than a frictional force generated between the second clamp unit and the substrate. The first and second clamp units each have a plurality of clamps;
The area of the portion where the clamp included in the first clamp unit is in contact with the substrate is
The alignment apparatus according to claim 1, wherein a clamp included in the second clamp unit is smaller than an area of a portion in contact with the substrate. The portion of the clamp included in the first clamp unit that contacts the substrate has a hemispherical shape,
The alignment apparatus according to claim 2, wherein a portion of the clamp included in the second clamp unit that contacts the substrate has a flat shape. The clamp included in the first clamp unit and the clamp included in the second clamp unit have the same shape,
The coefficient of friction between the clamp and the substrate included in the first clamp unit is:
The alignment apparatus according to claim 1, wherein a coefficient of friction between the clamp and the substrate included in the second clamp unit is smaller. The alignment apparatus according to claim 4, wherein a material having a small coefficient of friction with the substrate is disposed in a portion where the clamp and the substrate included in the first clamp unit are in contact with each other. A mask holder for placing the mask;
Measuring means for measuring the position of the substrate placed on the receiving claw and the position of the mask placed on the mask holding unit;
A control unit for controlling the driving unit;
Have
The control unit controls a relative position between the substrate holding unit and the mask holding unit based on the position of the substrate and the position of the mask acquired from the measurement unit. 4. The alignment apparatus according to any one of items 3. The substrate holding part holds a rectangular substrate,
The alignment method apparatus according to any one of claims 1 to 4, wherein the receiving claws and the clamp are disposed along a long side of the rectangular substrate. A deposition chamber;
An alignment apparatus comprising a substrate holding unit for holding a substrate and a mask holding unit for holding a mask inside the film forming chamber;
A film forming apparatus comprising:
A substrate holding part for holding the substrate
A pair of receiving claws on which a pair of opposite sides of the substrate are respectively mounted;
A pair of clamp units provided facing each of the receiving claws,
The pair of clamp units includes a first clamp unit that faces a receiving claw on which one side of the pair of opposite sides of the substrate is placed, and a first clamping unit that faces the receiving claw on which the other side is placed. 2 clamp units,
The frictional force generated between the first clamp unit and the substrate is
The film forming apparatus characterized by being smaller than a frictional force generated between the second clamp unit and the substrate. The first and second clamp units each have a plurality of clamps;
The area of the portion where the clamp included in the first clamp unit is in contact with the substrate is
The film forming apparatus according to claim 8, wherein a clamp included in the second clamp unit is smaller than an area of a portion in contact with the substrate. The portion of the clamp included in the first clamp unit that contacts the substrate has a hemispherical shape,
The film forming apparatus according to claim 9, wherein a portion of the clamp included in the second clamp unit that comes into contact with the substrate has a shape in contact with the substrate in a plane. The clamp included in the first clamp unit and the clamp included in the second clamp unit have the same shape,
The coefficient of friction between the clamp and the substrate included in the first clamp unit is:
The film forming apparatus according to claim 8, wherein a coefficient of friction between the clamp and the substrate included in the second clamp unit is smaller. Measuring means for measuring the position of the substrate placed on the substrate holding portion and the position of the mask placed on the mask holding portion;
A control unit for controlling the alignment apparatus;
Have
Based on the position of the substrate and the position of the mask acquired by the control unit from the measurement unit,
The film forming apparatus according to claim 8, wherein a relative position between the substrate holding unit and the mask holding unit is controlled. The substrate holding part holds a rectangular substrate,
The film forming apparatus according to any one of claims 8 to 12, wherein the receiving claws and the clamp are disposed along a long side of the rectangular substrate.   The film forming apparatus according to claim 8, wherein a film forming source for forming a film on the substrate is installed.   The film forming apparatus according to claim 14, wherein the film forming source is an evaporation source. An alignment method between a substrate and a mask,
An alignment step of adjusting a relative position between the substrate and the mask;
Placing the substrate relatively close to the substrate and placing the substrate on the mask; and
Have
The alignment step and the placing step are
An alignment method characterized in that the force for fixing one of a pair of opposing sides of the substrate is weaker than the force for fixing the other side. A film forming method comprising:
Placing the substrate on the mask using the alignment method according to claim 15;
A film forming step of forming a film on the substrate through the mask;
A film forming method comprising: An electronic device manufacturing method comprising:
A step of placing a substrate on a mask by the alignment method according to any one of claims 15;
A film forming step of forming a film on the substrate through the mask;
A method for manufacturing an electronic device, comprising: The method of manufacturing an electronic device according to claim 18, wherein in the film forming step, an organic film is formed using an evaporation method.

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