JP2006249544A - Reference position indicator, and metal mask position alignment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of correctly positioning the position of each mask part when fixing a metal mask 1 having a plurality of mask parts 2 to a frame while the metal mask is subjected to the tension. <P>SOLUTION: Each side of the metal mask 1 is held and pulled by a plurality of tension units 13 and the mask 1 is subjected to the tension. A glass scale 25 overlaps the mask 1, and the tension is adjusted so that cruciform marks 6a-6d formed on the mask 1 are matched with the reference mark formed on the glass scale 25, thereby each mask part 2 is correctly positioned. In addition, four corners of the glass scale 25 are supported by a supporting frame 40 via a connection member 41 to eliminate the deflection caused by the self weight of the four corners of the glass scale 25 so as to obtain uniform gaps between the glass scale 25 and the mask 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention provides an extremely thin region having different rigidity such as a metal mask having a mask portion having a large number of minute elongated openings, which is used for a vapor deposition mask used in an organic EL element manufacturing process. A device for aligning the position of the metal mask when fixing the metal mask to the frame-like frame in a flat state without distortion, and a reference for multiple locations within the metal mask when aligning the position of the metal mask The present invention relates to a reference position indicating device suitable for use in indicating a position.

  Conventionally, vacuum vapor deposition is performed in the manufacture of organic EL elements, and a metal mask having a mask portion having a large number of elongated minute openings that allow vapor deposition is used as the vapor deposition mask. In vapor deposition, the metal mask is attached to a frame having a large rigidity having an opening larger than that of the mask by a magnet or the like. However, in recent years, when the patterning has been miniaturized and the openings formed in the mask portion have become finer and the thickness of the metal mask itself has become thinner, the metal mask is simply attached to a frame-like frame with a magnet or the like. Only by using and fixing, there arises a problem that the mask portion is distorted or sag, and the accuracy of the opening cannot be maintained.

  Therefore, as a result of studies to solve this problem, the applicant of the present invention manufactured each of the four sides of the metal mask even in a multi-sided metal mask having a structure in which a plurality of mask portions are formed with an extremely thin metal plate. Holding the metal mask with a plurality of clamps, applying tension to the metal mask with each clamp, and adjusting the tension for each clamp makes the metal mask flat without distortion or sagging, and opens each mask portion. Can be held in a straight line and at a constant pitch, and in that state, the metal mask can be held flat by being tensioned even after the clamp is removed by fixing it to the frame-like frame by spot welding or the like. Therefore, it has been found that a multi-face mask can be held without distortion or sagging using a frame with a simple structure, Developed a method and apparatus for securing the frame-shaped frame in a state without distortion and sagging of the metal mask (see JP 2004-311335).

However, it has been found that there are further improvements in this method and apparatus. In other words, when applying tension to each of the four sides of the metal mask and fixing it to the frame, simply adjusting the tension so that there is no distortion or sagging in the metal mask does not necessarily lead to uniform elongation of the metal mask. For this reason, the positions of the plurality of mask portions formed on the metal mask may deviate from proper positions. For example, in the case of a multi-face mask for vapor deposition used for manufacturing an organic EL element, a total pitch of ± 10 μm or less may be required with respect to the position of each mask part, but depending on the tension applied to the metal mask, In some cases, the error becomes large, or the entire arrangement is twisted. To prevent this, a length measuring device that can measure the position of several mask parts with high tension (micron order) in the XY direction (vertical and horizontal directions) with tension applied to the metal mask. It is sufficient to adopt a method in which the tension is adjusted so as to obtain an appropriate position. However, this method has the following problems: (1) the length measuring device is expensive, (2) time is required for length measurement, the work efficiency is poor, and (3) position management cannot be performed at a plurality of locations at once. there were.
JP 2004-31335 A

  Therefore, in order to enable the present inventors to manage the positions of a plurality of locations in the metal mask with high accuracy and appropriate positions with a simple operation without using an expensive length measuring device, Focusing on the use of a glass scale on which fiducial marks for defining the positions of a plurality of locations on the metal mask are used, the central portion of the glass scale 25 is held by a holding member 34 as shown in FIG. Is moved down by the reciprocating drive mechanism 36 and positioned at a measurement position close to the metal mask 1 in a state where the tension is applied by the tension unit 13, and the reference mark formed on the lower surface of the glass scale 25 and the metal mask 1. The alignment mark formed in advance on the upper surface is monitored by the CCD camera 30, and the reference mark on the glass scale is metal. Developed a metal mask position alignment device with a configuration that positions multiple locations in the metal mask at appropriate positions with high accuracy by adjusting the tension so that the alignment marks formed in advance on the disc are aligned. .

  However, it has been found that there are further improvements in this device. That is, when the metal mask 1 is enlarged, the glass scale 25 is also enlarged accordingly, and the glass scale 25 is bent due to its own weight, as exaggerated in FIG. When such bending occurs, when the glass scale 25 is lowered and positioned at a measurement position close to the metal mask 1, the peripheral portion of the glass scale 25 may hit the metal mask and damage the metal mask 1. Further, when the lowered position is set so that the peripheral portion of the glass scale 25 does not contact the metal mask 1, the gap between the glass scale 25 and the metal mask 1 increases as it approaches the center. In order for the CCD camera 30 to simultaneously image the alignment mark of the metal mask 1 and the reference mark of the glass scale 25, both must be within the focal depth of the CCD camera. The gap distance L between the glass scale 25 and the metal mask 1 at the imaging position needs to be smaller than the focal depth of the CCD camera. However, when the glass scale 25 is bent as shown in FIG. However, depending on the imaging position, the CCD camera 30 may not be able to image the metal mask alignment mark and the glass scale reference mark well simultaneously. It was. Such a problem occurs, for example, when the glass scale 25 is 800 mm × 800 mm × 5 mm thick. In order to avoid this problem, it is conceivable to increase the rigidity by increasing the thickness of the glass scale, but the cost of the glass scale increases. Further, instead of holding the center of the glass scale 25, it is conceivable to move up and down while holding a plurality of locations (for example, four corners) of the glass scale. There arises a problem that it becomes difficult to install a CCD camera.

  The present invention has been made in view of such a problem, and a glass scale used for indicating a reference position with respect to a plurality of positions of a planar measurement target material such as a metal mask is suppressed in bending thereof, and the measurement target is measured. It is an object of the present invention to provide an apparatus (referred to as a reference position indicating apparatus) that can be positioned with a substantially constant gap size with respect to a material. Another object of the present invention is to provide a metal mask position alignment apparatus using the reference position indicating apparatus.

  The invention according to claim 1 of the present invention, which has been made to solve the above-mentioned problems, is a flat glass scale provided with a plurality of reference marks indicating reference positions with respect to a plurality of locations of a planar measurement object, and the glass scale is horizontal. A glass scale holding and moving device that holds the central area of the glass scale so that the glass scale is positioned at a measurement position close to the material to be measured that is horizontally disposed at a predetermined position; A support frame disposed at a fixed position on the upper side; and a flexible connection member that connects the support frame and a peripheral region of the glass scale, wherein the glass scale holding and moving device includes the glass scale holding device. When the scale is positioned at a measurement position close to the material to be measured, the gap between the peripheral area of the glass scale and the material to be measured has a predetermined gap size. In so that a reference position indicating device, characterized in that the arrangement for supporting the peripheral region of the glass scale.

  According to a second aspect of the present invention, in the reference position indicating device according to the first aspect, a length adjusting means is provided on the connecting member.

  According to a third aspect of the present invention, in the reference position indicating device according to the first or second aspect, a fixing magnet is provided at both ends of the connecting member.

  According to a fourth aspect of the present invention, in the reference position indicating device according to any one of the first to third aspects, the connecting member is provided so as to support the four corners of the glass scale. It is.

  In the invention according to claim 5, the reference position indicating device having the above-described configuration is applied to a metal mask position alignment device. That is, the invention according to claim 5 includes a plurality of tension units arranged so that tension can be applied by gripping a plurality of locations on each of the four sides of the metal mask having alignment marks at a plurality of locations in advance. A glass scale having a reference mark indicating a reference position for a plurality of alignment marks applied to the metal mask, the glass scale being close to the upper surface of the metal mask held by the plurality of tension units The reference position indicating device according to any one of claims 1 to 4, which is disposed so as to be positioned at a measurement position, an alignment mark formed at a plurality of locations of the metal mask, and the glass scale. An imaging means for imaging an overlapping portion of the reference marks, and the plurality of tensions; Knitting is a metal mask position alignment device characterized by having an adjustable adjusting means tension applied is.

  According to a sixth aspect of the present invention, in the metal mask position alignment apparatus according to the fifth aspect, the plurality of tension units are mounted on the X, Y, θ stage, and the metal mask and the glass are placed on the X, Y, θ stage. In this configuration, coarse positioning with the scale can be performed.

  The invention according to claim 7 is the metal mask position alignment device according to claim 5 or 6, wherein alignment marks are provided at four locations of the metal mask, and the alignment marks corresponding to the four alignment marks are Four image pickup means are provided, and each alignment mark can be picked up at the same time.

  In the reference position indicating device of the present invention described above, when the glass scale is lowered to the measurement position close to the material to be measured by the glass scale holding and moving device, the peripheral portion of the glass scale is supported by the support frame via the connecting member. Since it is supported, the downward bending of the peripheral portion of the glass scale is suppressed, and the peripheral portion of the glass scale does not come into contact with the material to be measured and is not damaged, and between the glass scale and the material to be measured. The gap dimension can be made almost uniform over the entire surface of the glass scale. Therefore, the glass scale and the material to be measured can be accommodated within the focal depth of the CCD camera, and the reference mark formed on the glass scale is used. The position alignment of the measurement material can be performed satisfactorily. In addition, when the glass scale is raised, the connecting member bends to cope with a change in the distance between the support frame and the glass scale. Further, since the support frame and the connecting member used for suppressing the bending due to the weight of the peripheral portion of the glass scale may have a simple structure, they can be manufactured at a low cost. Thus, even when a large glass scale is used, the glass scale can be positioned with a certain gap from the measured material without increasing the thickness of the glass scale and increasing the rigidity. Can be handled at low cost.

  Here, if a length adjusting means is provided in the connecting member, the height position of the glass scale when the glass scale is supported by the support frame via the connecting member can be freely adjusted. The gap dimension between the scale and the material to be measured can be made extremely uniform over the entire surface of the glass scale.

  In addition, if fixing magnets are provided at both ends of the connecting member, the connecting member can be easily attached at an arbitrary place, and the connecting member can be easily attached to a region where the deflection caused by the weight of the peripheral portion of the glass scale is large. Can be attached to support the region, and the gap dimension between the glass scale and the material to be measured can be made extremely uniform over the entire surface of the glass scale.

  The attachment position and the number of the connecting members to be used are arbitrary, and may be appropriately determined in consideration of the flexure caused by the weight of the peripheral portion of the glass scale. Preferred positions include the four corners of the glass scale. it can. If the connecting member is provided so as to support the four corners of the glass scale, the connecting member can support the region where the deflection due to its own weight is the largest, so the gap between the glass scale and the material to be measured. The advantage is that the dimensions can be made more uniform.

  According to the metal mask position alignment apparatus of the present invention, the glass scale is positioned close to the upper surface of the metal mask with tension applied to the four sides of the metal mask by the reference position pointing device, and used for alignment of a plurality of locations on the metal mask. By looking at the superimposed state of the mark and the reference mark on the glass scale with, for example, a CCD camera, it is possible to see whether or not the position where the metal mask alignment mark is attached is a predetermined proper position. By adjusting the tension applied to the metal mask so that the glass scale reference mark is aligned with the alignment mark of the alignment, the position in the metal mask can be adjusted to the appropriate position with high accuracy, and alignment can be achieved, For example, a plurality of mask parts are formed on a metal mask. It can be positioned at a predetermined position the position of each mask portion with high precision in the case. When performing this alignment, it is only necessary to match the alignment mark on the metal mask with the reference mark on the glass scale. Therefore, the judgment is easy, the tension of the metal mask can be adjusted easily, and the adjustment can be done in a short time. This is possible, and since a length measuring device is unnecessary, the function can be satisfied with an inexpensive device, which is economically advantageous. Furthermore, even when the metal mask is large and therefore the glass scale is also large, when the glass scale is lowered to the measurement position close to the metal mask, the glass scale is supported by the supporting frame through the connecting member. Because it is supported and bending due to its own weight is suppressed, the peripheral part of the glass scale does not come into contact with the metal mask and is not damaged, and the gap dimension between the glass scale and the metal mask is spread over the entire surface of the glass scale. It can be kept almost constant and within the focal depth of the CCD camera, and at the desired position of the metal mask, the alignment mark of the metal mask and the fiducial mark of the glass scale are imaged together by the CCD camera to confirm the overlap between them. Can do.

  The metal mask position alignment apparatus of the present invention can be used for any metal mask that needs to be held in a flat state free from distortion and sagging, but is particularly suitable for manufacturing an organic EL element that requires precision. It is preferably used for a metal mask used as a multi-face mask for vapor deposition. Hereinafter, a preferred embodiment of the present invention will be described by taking a metal mask used as a multi-face mask for vapor deposition in manufacturing an organic EL element as an example. FIG. 1 is a schematic perspective view of a main part of a metal mask position alignment apparatus (hereinafter abbreviated as an alignment apparatus) provided with a reference position indicating apparatus according to an embodiment of the present invention. In order to make the drawing easy to understand, the reference position indicating device is illustrated in a state of being separated upward from the actual mounting position. 2 and 3 are schematic cross-sectional views showing the alignment apparatus in different operating states, FIG. 4 is a schematic plan view showing a plurality of tension units provided in the alignment apparatus and a metal mask held by the tension units, and FIG. FIG. 6A is a schematic side view showing a connecting member that connects the support frame and the glass scale, and FIG. 6B is a schematic side view showing a modification of the connecting member. 7 is a schematic perspective view showing a metal mask handled by the alignment apparatus and a frame-like frame for fixing the metal mask, FIG. 8 is a schematic perspective view showing a vapor deposition mask unit formed by attaching the metal mask to the frame, and FIG. ), (B) are schematic plan views of the metal mask and the glass scale, and FIG. 10 (a) is a grid cross point of the reference line formed on the glass scale. (B) is an enlarged schematic plan view showing the cross mark formed on the metal mask, and (c) is an image of the overlapping area of the lattice cross and the cross mark. It is a schematic front view which shows the state displayed on.

  In FIG. 7, reference numeral 1 denotes a right-angled quadrilateral metal mask used as a vapor deposition mask, which is formed by arranging a plurality of mask portions 2 vertically and horizontally. Each mask portion 2 is provided with a large number of minute openings allowing vapor deposition. The shape and arrangement of the openings in each mask part 2 are arbitrary. For example, those in which elongated slit-like openings are arranged in parallel, those in which slot-like openings are arranged in the vertical direction and in parallel, etc. Can be mentioned. A frame 3 having a large rigidity for attaching the metal mask 1 includes an opening 4 having a size including a region (referred to as an effective region) in which a large number of mask portions 2 of the metal mask 1 are formed. The metal mask 1 is made larger in both the vertical and horizontal directions than the frame 3, and an easy cutting line 5 that can be easily cut by bending is formed at a position substantially corresponding to the outer peripheral edge of the frame 3. The easy cutting line 5 has a strength that can withstand a tensile force applied to the metal mask 1. Furthermore, cross marks 6a, 6b, 6c and 6d are formed as alignment marks in the metal mask 1 in the vicinity of the four corners of the effective area where the plurality of mask portions 2 are formed. Details of the cross marks 6a, 6b, 6c, and 6d will be described later. The thickness of the metal mask 1, the dimensions of the mask portion 2, the dimensions of a large number of minute openings formed thereon are not particularly limited, but as a typical example, the thickness of the metal mask 1 is 30 to 200 μm. The dimensions of the mask portion 2 are 50 to 70 mm in length, 30 to 50 mm in width, 40 to 100 μm in width of the opening, 80 to 200 μm in width of the non-porous portion between the openings arranged in parallel, etc. it can.

  1 to 4, an alignment apparatus generally indicated by reference numeral 10 includes a support base 11, an X, Y, θ stage 12 held on the support base 11 so that the upper surface 12 a is horizontal, A plurality of tension units 13 are provided on the upper surface 12 a of the X, Y, θ stage 12 so as to be able to grip and apply tension on each of the four sides of the metal mask 1. The X, Y, θ stage 12 can adjust the position of the horizontal upper surface 12a in the vertical direction (X direction) and the horizontal direction (Y direction) in the horizontal plane, and also rotates in the direction of rotation about the vertical axis at the center ( The position can also be adjusted in the θ direction.

  As shown in an enlarged view in FIG. 5, each tension unit 13 includes a base member 15, a clamp 17 movably held by the base member 15 via a linear motion guide 16, and a drive for reciprocating the clamp 17. Means 18 and the like are provided. Here, an air cylinder is used as the driving means 18, but a hydraulic cylinder, a servo motor or the like may be used instead of the air cylinder. The clamp 17 is a toggle mechanism that pivots the movable claw 17b to hold the metal mask 1 between the fixed claw 17a, the movable claw 17b, and the movable claw 17b while pressing the movable claw 17b firmly against the fixed claw 17a. And an air cylinder (both not shown). As can be clearly seen from FIG. 4, each tension unit 13 is arranged so that each side of the metal mask 1 can be gripped by a plurality of tension units 13 and tension can be applied to the side in a direction perpendicular thereto. Further, the clamps 17 of the plurality of tension units 13 arranged so as to hold each side of the metal mask 1 are arranged in accordance with the mask part 2 and the non-mask part of the metal mask 1, and accordingly, the metal mask The region extending in the vertical direction and the region extending in the horizontal direction in which one mask portion 2 is formed, and the region extending in the vertical direction without the mask portion and the region extending in the horizontal direction are each pulled by a separate clamp 17 to apply tension. Is possible.

  The driving means 18 provided in each of the plurality of tension units 13 has adjusting means (not shown) for individually adjusting the driving force by the driving means so that the tension applied to the metal mask 1 can be individually adjusted. Is provided. More specifically, an air supply pipe is connected to the air cylinder constituting the drive means 18, and a regulator capable of individually adjusting the supply pressure to each air cylinder is provided as an adjustment means in the air supply pipe. It has been. Note that air is supplied to the air supply pipes connected to these air cylinders via a common on-off valve so that the drive means (air cylinders) 18 of all the tension units 13 can be operated simultaneously. A speed controller is also provided in the air supply piping to each air cylinder so that the operation timing of each air cylinder can be adjusted.

  2, 3, 5, etc., the base member 15 of the tension unit 13 is provided with a frame support 20 that supports the frame 3. The frame support 20 places the frame 3 thereon, thereby positioning the frame 3 at a predetermined position in the horizontal plane, and the upper surface of the frame 3 is held by the clamp 17 and applied to the tension applied to the metal mask 1. It arrange | positions so that it can also position in an up-down direction so that it may become a position which touches substantially.

  In FIG. 1 to FIG. 3, the alignment apparatus 10 further includes a moving table 23 that is horizontally movably held on a side frame 22 fixed to the support table 11, and the moving table 23 is held by a tension unit 13. A moving device (not shown) that reciprocates between a predetermined position above the metal mask 1 and a standby position that leaves the metal mask 1, a reference position indicating device 24 held on the moving table 23, Four image pickup means 30 and the like held on the movable table 23 are provided.

  The reference position indicating device 24 is attached to a glass scale 25, a glass scale holding / moving device 27 that moves up and down while holding the central region of the glass scale 25, and a moving base 23, and is disposed at a fixed position above the glass scale 25. And a plurality of connecting members 41 attached so as to connect the supporting frame 40 and the peripheral area of the glass scale 25. As shown in FIGS. 9B and 10A, the glass scale 25 has a large number of reference lines 28 formed in a lattice pattern at a constant pitch (for example, 10 mm pitch) on the surface of a transparent plate such as a glass plate. The grid cross points formed by intersecting the vertical and horizontal reference lines 28 are used as positioning reference marks, and are arranged so that the surface on which the reference lines 28 are formed faces the metal mask 1. Yes. Note that cross marks 29 are also formed at regular pitches in the vertical and horizontal directions as scales between the reference lines 28. The line width of the reference line 28 is not particularly limited, but is set to about 20 μm.

  The lattice cross points of the reference lines 28 in the areas A, B, C, and D shown in FIG. 9B are cross marks 6a, which are alignment marks formed on the metal mask 1 shown in FIG. 9A. It acts as a reference mark indicating the reference position of 6b, 6c, 6d. That is, by aligning the four cross marks 6a, 6b, 6c, 6d of the metal mask 1 with the lattice cross points of the reference line 28 in the areas A, B, C, D of the glass scale 25, the metal mask 1 The positions of the four cross marks 6a, 6b, 6c and 6d can be positioned at predetermined positions, and the effective area of the metal mask 1 can be positioned at the predetermined positions. In other words, the positions of the four cross marks 6a, 6b, 6c and 6d on the metal mask 1 are adjusted by adjusting the tension applied to the metal mask 1 so that the cross marks 6a, 6b, 6c and 6d are formed on the glass scale 25. When aligned with the grid cross points of the reference line 28 in A, B, C, D, the metal mask 1 is stretched without distortion or sagging and each mask portion 2 is positioned at a predetermined position. It has been established. Here, as shown in FIG. 9A, the formation positions of the cross marks 6a, 6b, 6c, and 6d are in the vicinity of the four corners of the effective area in which a large number of mask portions 2 are formed. Although it is preferable because the overall elongation and position can be appropriately adjusted with high accuracy and the position of each mask portion 2 can also be appropriately adjusted, it is not limited to this position. Further, the number of cross marks 6a to 6d formed on the metal mask 1 can be appropriately increased or decreased.

  The means for forming the cross mark 6 (indicated by reference numeral 6 in the case of general description not related to the position of the cross mark) on the metal mask 1 is not particularly limited, but is preferably formed by half etching. . As shown in FIGS. 10A and 10B, the cross mark 6 is formed to have a line width wider than the line width of the reference line 28 of the glass scale 25. FIG. As shown, when a state in which the vertical and horizontal reference lines 28 are correctly overlapped with the cross mark 6 is imaged and enlarged and displayed on the monitor 31, the cross mark 6 lines appear on both sides of the reference line 28. Alternatively, it can be recognized by image processing. The line width of the cross mark 6 may be selected to be about 50 μm when the line width of the reference line 28 is 20 μm. The length of the cross mark 6 only needs to be long enough to be recognized by visual observation or image processing on the monitor 31, and may be about 250 μm, for example.

  1 to 3 and FIG. 6A, a connecting member 41 that connects the support frame 40 and the peripheral region of the glass scale 25 is a flexible wire 42 and a length attached to an intermediate region of the wire 42. Adjustment means, for example, turnbuckles 43, and fixing magnets 44 attached to both ends, and the magnets 44 on both ends are attracted and held on the peripheral region of the support frame 40 and the glass scale 25, so that a desired position can be obtained. It can be attached to. A plate material 45 such as a steel plate or a magnet plate that can be adsorbed by a magnet is fixed in advance to the peripheral region of the glass scale 25 with an adhesive or the like. The attachment position of the connecting member 41 with respect to the glass scale 25 may be appropriately selected as a region where the downward deflection due to its own weight increases when the glass scale 25 is lifted while holding its central region. Then, it is set as the four corners of the glass scale 25. In addition, it is good also as a structure which connects a connection member also to the intermediate area | region of the edge | side of the glass scale 25 as needed. The length of the connecting member 41 attached to the support frame 40 and the glass scale 25 is such that the periphery of the glass scale 25 when the glass scale 25 is positioned at the measurement position close to the metal mask 1 as shown in FIG. The turnbuckle 43 is adjusted so as to support the region and have a predetermined gap dimension e between the metal mask 1 and the region. With this configuration, even if the glass scale 25 is a large size exceeding 800 mm × 800 mm and is as thin as about 5 mm, the glass scale 25 is lowered to a measurement position close to the metal mask 1. In this case, the bending of the peripheral portion including the four corners due to its own weight is suppressed by the connecting member 41, the entire metal mask 1 is held in a substantially flat state, and the gap dimension e between the glass scale 25 and the metal mask 1 is made of glass. It becomes almost constant over the entire surface of the scale 25. When the glass scale 25 is lifted by the glass scale holding and moving device 27, the distance between the support frame 40 and the glass scale 25 is shortened, but the wire 42 is flexible in the connecting member 41 that connects the both. Therefore, since this is bent, it can respond to shortening of the space | interval of the support frame 40 and the glass scale 25, and does not produce any trouble.

  1 to 3, the glass scale holding and moving device 27 holds the glass scale 25 so as to be parallel to the metal mask 1 that is a measurement target positioned below the glass scale 25, and holds the glass scale 25 in the metal. This is for moving up and down to a standby position (a position shown in FIG. 2) separated above the mask 1 and a measurement position (a position shown in FIG. 3) close to the upper surface of the metal mask 1. The glass scale holding and moving device 27 includes a support plate 32 fixed to the moving table 23 and a metal mask held by a clamp 17 in a vertical direction on a linear motion bearing (not shown) provided on the support plate 32. 1, a guide rod 33 guided so as to be movable in a direction perpendicular to 1, a holding member 34 fixed to the lower end thereof and movable in a direction perpendicular to the metal mask 1, and the holding member 34 reciprocating in the direction perpendicular to the metal mask 1. A reciprocating drive mechanism 36 such as an electric actuator to be moved is provided, and the glass scale 25 is held by fixing the holding member 34 to the central region on the upper surface of the glass scale 25.

  As described above, the glass scale holding and moving device 27 can reciprocate the glass scale 25 between the standby position shown in FIG. 2 and the measurement position shown in FIG. Here, when the glass scale 25 is lowered to the measurement position, the measurement position is a position where the glass scale 25 is not in contact with the metal mask 1 so that the glass scale 25 does not contact the metal mask 1 and cause trouble. However, the reference line 28 formed on the lower surface side of the glass scale 25 and the cross mark 6 of the metal mask 1 are kept as close as possible so that the imaging means 30 can capture images simultaneously. As described above, the glass scale 25 is held in the central area by the glass scale holding and moving device 27, and when the glass scale 25 is lowered to the measurement position, the peripheral area is supported by the connecting member 41, and the whole is maintained in a substantially flat state. Even if the measurement position is set at a position very close to the metal mask 1, there is no problem and the gap dimension e between the glass scale 25 and the metal mask 1 can be made substantially uniform over the entire surface of the glass scale 25. The gap dimension e between the glass scale 25 lowered to the measurement position and the metal mask 1 is preferably set to about 50 to 200 μm, more preferably about 50 to 100 μm.

  The imaging means 30 is capable of simultaneously imaging the reference line 28 of the glass scale 25 and the cross mark 6 of the metal mask 1, and a CCD camera is used in this embodiment. The CCD camera 30 has four cross marks 6a, 6b, 6c, and 6d and lattice cross points corresponding to the reference lines 28 of the glass scale 25 (lattice cross points in the regions A, B, C, and D shown in FIG. 9). The depth of focus is determined so that the cross mark 6 of the metal mask 1 and the reference line 28 of the glass scale 25 at the measurement position can be simultaneously imaged. .

  Next, an alignment operation performed by the alignment apparatus 10 having the above configuration will be described. The frame 3 is held by the frame supports 20 of the plurality of tension units 13 in a state where the moving table 23 holding the glass scale 25 is in the standby position off the upper side of the X, Y, θ stage 12, and then The metal mask 1 is placed on top, and the four sides thereof are held by the clamps 17 of the plurality of tension units 13. This state is the state shown in FIG. At this time, the metal mask 1 is positioned with respect to the frame 3 using a plurality of positioning pins (not shown). Next, the moving base 23 moves above the X, Y, θ stage 12 and stops at a predetermined position (see FIG. 2). At this time, the glass scale 25 is held at the upper standby position and does not interfere with the tension unit 13. Next, pressurized air is sent to driving means (air cylinder) 18 connected to each clamp 17 to move each clamp 17 in the direction in which the metal mask 1 is pulled, and the metal mask 1 is moved in both the vertical and horizontal directions by a number of clamps. A small tension is applied to the metal mask 1 so that the metal mask 1 is stretched. Thereafter, the positioning pin is removed so that a large tension can be applied to the metal mask 1 without hindrance. Even if the positioning pins are removed from the metal mask 1, the position of the metal mask 1 with respect to the frame 3 does not change much, and the desired positioning accuracy of the metal mask 1 with respect to the frame 3 is maintained.

  Next, as shown in FIG. 3, the glass scale holding and moving device 27 lowers the glass scale 25 to a measurement position close to the upper surface of the metal mask 1 and stops at that position. At this time, as described above, the four corners of the glass scale 25 are supported by the connecting member 41, and the glass scale 25 is almost free from bending. Therefore, when the glass scale 25 is lowered, the peripheral portion thereof is the metal mask 1. There will be no damage caused by touching. Further, in the state where the glass scale 25 is lowered to the measurement position, the gap dimension between the entire surface of the glass scale 25 and the metal mask 1 is kept substantially uniform, and a reference line formed on the lower surface of the glass scale 25. 28 and the cross marks 6a, 6b, 6c, 6d formed on the upper surface of the metal mask 1 are kept within the focal depth of the CCD camera 30, and both can be imaged simultaneously. In this state, imaging is started by the CCD camera 30 and an image is displayed on the monitor 31. While confirming this, the operator adjusts the X, Y, and θ stages 12 to move the position of the metal mask 1 in the X, Y, and θ directions, and the cross marks 6a, 6b, 6c, and 6d of the metal mask 1 are moved. Is roughly positioned at the corresponding grid cross point of the reference line 28 of the glass scale 25. After the rough positioning, the X, Y, θ stage 12 is fixed to the position, and the driving force of the driving means 18 of the plurality of tension units 13 is individually adjusted and applied to the metal mask 1 while checking with the monitor 31. The tension is adjusted so that the cross marks 6a, 6b, 6c, and 6d are aligned with the lattice cross points of the corresponding glass scale 25. When all the cross marks 6a, 6b, 6c, and 6d coincide with the corresponding lattice cross points, the plurality of mask portions 2 formed on the metal mask 1 are respectively positioned at predetermined positions. Further, the metal mask 1 is in a flat state without distortion or sagging, and a large number of openings of the mask portion 2 are aligned in parallel. That is, the metal mask position alignment is completed.

  Thereafter, with the tension applied to the metal mask 1, the glass scale 25 is returned to the upper standby position, and the moving table 23 is also returned to the standby position outside the metal mask 1, and the metal mask 1 is attached to the frame 3. Spot welding (see reference numeral 47 in FIG. 4) using a laser or the like (not shown) and fixing. Thereafter, the metal mask 1 is removed from the clamp 17, and the peripheral portion of the metal mask 1 is removed using the easy cutting line 5. As described above, as shown in FIG. 8, the vapor deposition mask unit 8 having a configuration in which the metal mask 1 is fixed to the frame 3 with a large number of spot welds 47 is manufactured.

  In the vapor deposition mask unit 8 obtained, the metal mask 1 is kept in a state in which there is no distortion or sagging, and a large number of openings of the mask part 2 are accurately aligned in parallel. It is kept within a predetermined dimensional accuracy. Thus, by performing vapor deposition using the vapor deposition mask unit 8, it is possible to accurately perform vapor deposition of a fine pattern with multiple faces. For example, a deposition substrate such as a glass substrate is attached to the deposition mask unit 8, set in a deposition machine, and an organic layer of an organic EL element or a cathode electrode is deposited, thereby depositing a fine pattern with high positional accuracy. It can be performed and a high quality organic layer or cathode electrode can be formed.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to this embodiment, and can be changed as appropriate within the scope of the claims. For example, in the above-described embodiment, as shown in FIG. 6A, the connecting member 41 has a structure including the wire 42, the turnbuckle 43, and the magnet 44. However, the connecting member is not limited to this structure. A structure in which a coil spring 46 is inserted at an intermediate position of the wire 42 as in a connecting member 41A shown in FIG. Even in the connecting member 41 </ b> A using the coil spring 46 as described above, the coil spring 46 is adjusted when the glass scale 25 is positioned at the measurement position close to the metal mask 1 by adjusting the entire length with the turnbuckle 43. Is applied with a spring force large enough to cancel the deflection due to its own weight that has occurred in the peripheral area of the glass scale 25, and supports the peripheral area of the glass scale 25 to have a predetermined gap dimension e between the metal mask 1 and the metal mask 1. be able to. In this connecting member 41A, since the spring force of the coil spring 46 is used, the length adjustment by the turnbuckle 43 may be rough compared to the connecting member 41 shown in FIG. The advantage is obtained.

  In the above-described embodiment, the monitor 31 determines whether or not the overlap of the cross mark 6 of the metal mask 1 and the lattice cross point of the glass scale 25 coincides when adjusting the tension applied to the metal mask 1. However, instead of visual inspection, a signal from the CCD camera 30 may be image-processed for determination. In the above-described embodiment, the CCD camera 30 is provided corresponding to each cross mark 6. However, the present invention is not limited to this, and one or two CCD cameras 30 should be used and the CCD camera 30 should be imaged. You may take the method of moving to a position and using it. However, if the CCD camera 30 is provided corresponding to each cross mark 6 as in the illustrated embodiment, the tension adjustment can be performed while monitoring all the cross marks 6, and the tension adjustment can be easily performed. And the advantage of being able to carry out quickly is obtained.

  Furthermore, in the above-described embodiment, the cross mark 6 is used as the alignment mark formed on the metal mask 1, but the alignment mark is not limited to the cross mark, and a reference mark (for example, a reference mark) formed on the glass scale 25 is used. Any mark can be used as long as it can be aligned with the line 28). For example, a square mark may be used. In addition, the alignment mark is not limited to a single mark that can indicate the position in the vertical direction and the horizontal direction, such as a cross mark or a square mark, but is simply a horizontal line or a vertical line. In addition, those indicating only the position in the vertical direction or those indicating only the position in the horizontal direction may be used in appropriate combination. Furthermore, in the above-described embodiment, a large number of reference lines 28 are formed as a reference mark on the glass scale 25 in a lattice shape, but it is not necessary to provide a large number of reference lines 28 provided on the glass scale 25 in this manner. A reference line 28 that passes only the areas A, B, C, and D in FIG. 9B may be used. Further, only the areas A, B, C, and D in FIG. 9B may be used. Alternatively, a cross mark may be formed as a reference mark. It should be noted that, if a glass scale 25 having a large number of reference lines 28 formed in a lattice shape is used as in the illustrated glass scale 25, it is possible to obtain an advantage that it can be applied to various sizes of metal masks.

  Furthermore, in the above-described embodiment, the alignment marks (cross marks 6) are formed at four locations on the metal mask 1, but the number of alignment mark formation locations can be increased or decreased as appropriate. If positioning in only the direction or only in the horizontal direction is sufficient, the alignment marks may be changed to be formed only in two places separated in the vertical direction or only in two places separated in the horizontal direction.

  Furthermore, in the above-described embodiment, the tension unit 13 that supports the metal mask 1 is held on the X, Y, and θ stages 12 in order to perform the rough positioning of the metal mask 1 and the glass scale 25. The reference position indicating device 24 having the glass scale 25 may be held on the X, Y, and θ stages to adjust the position of the glass scale 25. In some cases, coarse positioning may be omitted, and alignment of the cross mark and the reference line may be performed only by tension adjustment. However, as described in the embodiment, if rough alignment is performed, there is an advantage that tension adjustment for alignment between the cross mark and the reference line becomes easy.

  Although the embodiment in which the reference position indicating device of the present invention is used as an apparatus for performing the position alignment of a metal mask has been described above, the reference position indicating device of the present invention is not limited to this application, but on a planar measurement object. It can be used for any application that needs to indicate the position of a plurality of locations.

The schematic perspective view of the principal part of the alignment apparatus which concerns on embodiment of this invention 1 is a schematic cross-sectional view showing the alignment apparatus shown in FIG. 1 in a state where the glass scale is in the upper standby position. FIG. 1 is a schematic cross-sectional view showing the alignment apparatus shown in FIG. FIG. 1 is a schematic plan view showing a plurality of tension units provided in the alignment apparatus shown in FIG. 1 and a metal mask held by the tension units. Schematic side view of tension unit (A) is a schematic side view which shows the connection member which has connected the support frame and the glass scale, (b) is a schematic side view which shows the modification of a connection member. FIG. 1 is a schematic perspective view showing a metal mask handled by the alignment apparatus shown in FIG. 1 and a frame-like frame for fixing the metal mask. Schematic perspective view of a vapor deposition mask unit formed by fixing a metal mask to a frame (A) is a schematic plan view of a metal mask, (b) is a schematic plan view of a glass scale. (A) is a schematic plan view showing an enlarged lattice cross-point region of a reference line formed on a glass scale, (b) is a schematic plan view showing an enlarged cross mark formed on a metal mask, c) is a schematic front view showing a state in which the overlapping area of the lattice cross point and the cross mark is imaged and displayed on the monitor. Schematic side view showing a state where the glass scale is placed near the metal mask in tension and the metal mask is aligned. Schematic side view explaining the problems that occur when the glass scale is placed close to the metal mask in the tensioned state

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal mask 2 Mask part 3 Frame 4 Opening 5 Easy cutting line 6, 6a, 6b, 6c, 6d Cross mark (alignment mark)
DESCRIPTION OF SYMBOLS 8 Deposition mask unit 10 Alignment apparatus 11 Support stand 12 X, Y, (theta) stage 13 Tension unit 15 Base member 16 Direct motion guide 17 Clamp 17a Fixed claw 17b Movable claw 18 Driving means (air cylinder)
20 Frame support 22 Side frame 23 Moving table 24 Reference position indicating device 25 Glass scale 27 Glass scale holding and moving device 28 Reference line (reference mark)
30 Imaging means (CCD camera)
31 monitor 32 support plate 33 guide rod 34 holding member 36 reciprocating drive mechanism 40 support frame 41 connecting member 42 wire 43 turnbuckle 44 magnet 45 plate material 46 coil spring 47 spot welded portion

Claims (7)

  A flat glass scale provided with a plurality of reference marks indicating reference positions with respect to a plurality of locations of a planar measured material, and a central area of the glass scale so that the glass scale is horizontal, the glass scale A glass scale holding and moving device positioned at a measurement position close to the material to be measured that is horizontally disposed at a predetermined position, a support frame disposed at a fixed position above the glass scale, the support frame, and the A flexible connecting member that connects peripheral areas of the glass scale, and the connecting member moves the glass scale when the glass scale holding and moving device positions the glass scale at a measurement position close to the material to be measured. A configuration that supports the peripheral region of the glass scale so that a predetermined gap dimension is provided between the peripheral region of the scale and the material to be measured. Reference position indicating apparatus, characterized in that there.   The reference position indicating device according to claim 1, wherein the connecting member has a length adjusting means.   The reference position indicating device according to claim 1, wherein the connecting member has fixing magnets at both ends thereof.   The reference position indicating device according to any one of claims 1 to 3, wherein the connecting member is provided to support four corners of the glass scale.   A plurality of tension units arranged so that tension can be applied by holding a plurality of locations on each of the four sides of the metal mask with alignment marks at a plurality of locations in advance, and a plurality of tension units applied to the metal mask A glass scale having a reference mark indicating a reference position with respect to the alignment mark, and the glass scale can be positioned at a measurement position close to the upper surface of the metal mask held by the plurality of tension units. The reference position indicating device according to any one of claims 1 to 4, and an imaging unit that images an overlapping portion of an alignment mark formed at a plurality of locations of the metal mask and the reference mark of the glass scale. Adjusting the tension applied by the plurality of tension units. Metal mask position alignment device characterized by having the possible adjusting means.   6. The metal mask position alignment apparatus according to claim 5, wherein the plurality of tension units are mounted on an X, Y, and θ stage.   7. The metal according to claim 5, wherein alignment marks are provided at four locations on the metal mask, and four imaging means are provided corresponding to the alignment marks at four locations. Mask position alignment device.

Images