JP2006265712A - Standard position indicating device and metal mask position alignment device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique where, when a metal mask 1 on which a plurality of mask parts 2 having many opening parts are arranged is fixed to a frame, the position of each mask part is correctly aligned. <P>SOLUTION: Each side of the metal mask 1 is grasped by a plurality of tension units 13 and is pulled, so as to apply tension to the metal mask 1. Further, a glass scale is superimposed on the lower side of the metal mask 1, the superimposed parts of standard marks provided at the opening part of the metal mask 1 and the glass scale are monitored by a CCD (Charge-Coupled Device) camera 30, and the tension applied to the metal mask is regulated in such a manner that both are made into the correctly superimposed positions, thus the position of each mask part 2 is correctly aligned. Further, by supporting the peripheral part of the glass scale 25 by ball type supporters 26, the deflection of the glass scale by gravity is prevented, and the gap dimensions between the metal mask 1 and the glass scale 25 are uniformly held over the whole face of the glass scale. <P>COPYRIGHT: (C)2007,JPO&INPIT

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 wrinkles and sagging, and opens each mask portion. Can be held in a straight line and at a constant pitch, and in this 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 and sagging by using a frame with a simple structure. Tarumasuku developed a method and apparatus for securing the frame-shaped frame without distortion and sagging state (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 a reference mark for defining an appropriate position of the opening formed in the metal mask is used, as shown in FIG. 10, the upper surface of the X, Y, θ stage 23 is illuminated for transmission. A device 24 and a glass scale 25 are attached, and the glass scale 25 is positioned at a position close to the lower surface of the metal mask 1 in a state where the tension is applied by the tension unit 13, and a reference formed on the upper surface of the glass scale 25. The position of the mark and the opening of the metal mask 1 is monitored by the CCD camera 30, and the glass scale 25 is attached to the metal mask 1 by the X, Y, θ stage 23. After coarse positioning, the tension adjustment is performed so that the plurality of openings formed in the metal mask match the fiducial marks on the corresponding glass scale. We have developed a metal mask position alignment device that is configured with high precision and proper positioning.

  However, it has been found that there are further improvements in this device. That is, when the size of the metal mask 1 is increased, the glass scale 25 and the transmission illumination device 24 are increased in size accordingly, and the X, Y, and θ stages 23 that support them are also increased in size. In particular, the X, Y, and θ stages 23 are increased in size. Conversion will be the biggest cause of cost increase. Therefore, as shown in FIG. 11, it is possible to reduce the cost by using a small X, Y, θ stage 23 and reducing the size of the transmission illumination device 24 and arranging it downward. As shown in an exaggerated manner in FIG. 11, bending due to its own weight occurs in an unsupported region of the glass scale 25. When this deflection increases, the distance L between the metal mask 1 and the glass scale 25 increases. In order to determine whether or not the positions of both of the openings 40 of the metal mask 1 and the reference mark 42 of the glass scale 25 are simultaneously imaged by the CCD camera 30, both are within the focal depth of the CCD camera. Therefore, the gap distance L between the glass scale 25 and the metal mask 1 at the imaging position by the CCD camera 30 needs to be smaller than the focal depth of the CCD camera. When the deflection is increased, a region where the gap interval L is larger than the focal depth of the CCD camera is widened, and depending on the imaging position, the metal mask opening 40 and the reference mark 42 of the glass scale 25 are simultaneously imaged by the CCD camera 30. The problem of not being able to do so occurred. In order to suppress the bending which arises in a glass scale, increasing the thickness of a glass scale and raising rigidity can be considered, but the cost of a glass scale will become high.

  The present invention has been made in view of such problems, and supports a glass scale used to indicate a reference position with respect to a plurality of locations of a planar measurement target material such as a metal mask with small X, Y, and θ stages. However, an apparatus (referred to as a reference position indicating device) that can be positioned with a substantially constant gap size with respect to the material to be measured by suppressing bending due to its own weight that may occur in the peripheral area of the glass scale. The issue is to provide. 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. An X, Y, θ stage that holds the central area of the glass scale, and a ball mold that is arranged to support the lower surface of the glass scale so as to suppress bending due to its own weight in the peripheral area of the glass scale. A reference position indicating device having a support device.

  According to a second aspect of the present invention, in the reference position indicating device according to the first aspect, the ball-type support device is provided so as to support the vicinity of the four corners of the glass scale.

  According to a third aspect of the present invention, in the reference position indicating device according to the first or second aspect, a height capable of adjusting a height position of a ball supporting the glass scale on the ball type support device. An adjustment mechanism is provided.

  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, a reflecting mirror is laminated on a lower surface of the glass scale, and the ball-type support device is attached to the reflecting mirror. The arrangement is such that the lower surface is supported.

  According to a fifth aspect of the present invention, the reference position indicating device according to any one of the first to third aspects 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 a large number of openings, and the metal mask. A glass scale having a plurality of reference marks having a plurality of reference marks having a size smaller than that of the plurality of openings, the glass scale having a plurality of reference marks smaller than the openings. The reference position indicating device according to any one of claims 1 to 3, and a lower surface side of the glass scale, wherein the reference position indicating device is disposed close to the lower surface of the metal mask stretched by the plurality of tension units. A transparent illumination device disposed above the metal mask in a state of being stretched by the plurality of tension units, and opening the metal mask. Imaging means for imaging parts and the overlapped portion of the reference mark of the glass scale, a metal mask position alignment device having an adjustable adjustment means the tension of the plurality of tension unit is granted.

  According to a sixth aspect of the present invention, the reference position indicating device according to the fourth aspect is applied to a metal mask position alignment device. That is, the invention according to claim 6 includes 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 having a large number of openings, and the metal mask. A glass scale having a plurality of reference marks having a plurality of reference marks having a size smaller than that of the plurality of openings, the glass scale having a plurality of reference marks smaller than the openings. 5. The reference position indicating device according to claim 4, wherein the reference position indicating device is disposed close to a lower surface of the metal mask stretched by the plurality of tension units, and the metal mask stretched by the plurality of tension units. An imaging means for imaging the overlapping portion of the opening of the metal mask and the fiducial mark of the glass scale; Tension unit which is a metal mask position alignment device having an adjustable adjusting means tension applied is.

  According to a seventh aspect of the present invention, in the metal mask position alignment apparatus according to the fifth or sixth aspect of the present invention, four image pickup means are provided so that four openings can be picked up simultaneously. .

  In the above-described reference position indicating device of the present invention, when the reflecting mirror is arranged on the lower surface of the glass scale or on the lower surface side of the glass scale, the lower surface of the reflecting mirror is supported by the ball type support device. Even when only the central region of the glass scale is supported by the X, Y, and θ stages of the glass scale, even if the glass scale is large, for example, 1000 mm × 1000 mm or more, the X, Y, The deflection due to the weight of the area not supported by the θ stage can be suppressed, and the gap between the glass scale and the material to be measured can be made almost uniform over the entire surface of the glass scale. Position alignment of the material to be measured using a reference mark formed on the glass scale that can be stored within the focal depth of the CCD camera It can be performed well. In addition, since a small X, Y, θ stage and a ball-type support device are used to support the glass scale, the cost is lower than when a large X, Y, θ stage that supports the entire surface of the glass scale is used. The cost can be reduced as compared with the case of using a small X, Y, θ stage and increasing the thickness of the glass scale to increase the rigidity. Further, since the lower surface of the glass scale or the lower surface of the reflecting mirror on the lower surface side of the glass scale is supported by the ball type support device, the glass scale or the reflecting mirror can move smoothly with respect to the ball type support device. When the glass scale is moved on the X, Y, and θ stages in order to position the glass scale with respect to the material to be measured, the glass scale can be moved smoothly, and positioning can be performed without any trouble.

  Here, if the ball-type support device is provided in the vicinity of the four corners of the glass scale, the ball-type support device can support the region where the deflection is the largest, so the gap dimension between the glass scale and the material to be measured can be set. The advantage of being more uniform is obtained.

  Further, if a height adjusting mechanism capable of adjusting the height position of the ball is provided in the ball type support device, the height can be increased even if the manufacturing accuracy and assembly accuracy of the ball type support device are not so high. The adjustment by the adjusting mechanism can uniformly adjust the gap size between the glass scale and the material to be measured, and the advantage that the manufacturing and assembling of the ball-type support device is facilitated can be obtained.

  According to the metal mask position alignment apparatus of the present invention, the glass scale is positioned close to the lower surface of the metal mask in a state where tension is applied to the four sides of the metal mask. It is possible to see whether or not the opening of the metal mask is at a predetermined proper position by looking at the overlapping state of the metal mask, so that the opening of the metal mask is aligned with the fiducial mark on the glass scale. By adjusting the tension to be applied, the position in the metal mask can be aligned with an appropriate position with high accuracy, and alignment can be achieved. For example, when a plurality of mask portions are formed on the metal mask, each mask The position of the part can be positioned at a predetermined position with high accuracy. When performing this alignment, it is only necessary to align the opening of the metal mask with the fiducial mark on the glass scale, making it easy to make judgments, making it easy to adjust the tension of the metal mask, and making adjustments in a short time. It is. Further, since a length measuring device is unnecessary, the function can be satisfied with an inexpensive device, which is economically advantageous. Furthermore, even when the glass scale is large, it is possible to suppress bending due to its own weight in the peripheral area of the glass scale, so that the gap dimension between the glass scale and the metal mask can be kept almost constant and within the focal depth of the CCD camera. In addition, the CCD camera can image the metal mask opening and the glass scale reference mark together at the desired position of the metal mask to confirm the overlap between the two, and the large metal mask can be well aligned. be able to.

  Here, if four image pickup means are provided so that four openings can be picked up simultaneously, tension adjustment can be performed while simultaneously monitoring the four openings. The advantage is that it can be done quickly.

  The present invention can be applied to any metal mask that needs to be kept flat without distortion or sagging, but is particularly suitable as a multi-face mask for vapor deposition for manufacturing an organic EL element that requires precision. It is preferable to apply to the metal mask to be used. 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, and FIG. 2 is a partial view of the alignment apparatus. FIG. 3 is a schematic side view showing a tension unit provided in the alignment apparatus, 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 unit. FIG. 5 is a schematic side view showing a ball-type support device supporting a glass scale and its surroundings, FIG. 6 is a schematic side view showing a part of an alignment device according to another embodiment, and FIG. FIG. 8 is a schematic perspective view showing a metal mask handled by the alignment device of FIG. FIG. 9A is a schematic plan view showing an enlarged reference mark formed on the glass scale, and FIG. 9B is formed on the metal mask. FIG. 2C is a schematic plan view showing an enlarged opening, and FIG. 3C is a schematic front view showing a state where an overlapping area between the opening and the reference mark is imaged and displayed on a monitor.

  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 portion are arbitrary. For example, there are those in which elongated slit-like openings are arranged in parallel, rectangular openings are arranged in the vertical direction and in parallel, and the like. be able to. Many of the openings formed in the mask portion 2 are used for positioning the metal mask 1 as will be described later. Reference numeral 3 denotes a frame frame having a large rigidity for attaching the metal mask 1, and 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. Although the thickness of the metal mask 1, the dimension of the mask part 2, the dimension of the opening formed in it are not specifically limited, the thickness of the metal mask 1 is typically 30 to 200 μm, and the mask part 2 As for the dimensions, the length is 50 to 70 mm, the width is 30 to 50 mm, the width of the opening is 40 to 100 μm, the width of the non-porous portion between the openings is 80 to 200 μm, and the like.

  1, 2, and 4, an alignment apparatus generally indicated by a reference numeral 10 applies tension to the support base 11 and the support base 11 by gripping a plurality of locations on each of the four sides of the metal mask 1. A plurality of tension units 13 are arranged so as to be able to.

  As shown in an enlarged view in FIG. 3, 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 A region extending in the vertical direction and a region extending in the horizontal direction in which one mask portion 2 is formed, and a region extending in the vertical direction and a region extending in the horizontal direction without the mask portion, that is, regions having different rigidity, are separately clamped. It is possible to apply tension by pulling at 17.

  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 and 3, a frame support 20 that supports the frame 3 is provided on the base member 15 of the tension unit 13. 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.

  Further, the support base 11 is provided with a reference position indicating device 22. The reference position indicating device 22 includes an X, Y, θ stage 23, a glass scale 25 held by the stage 23, a ball type support device 26 arranged to support the lower surface of the glass scale 25, and the glass scale 25 downward. The transmission illumination device 24 and the like are arranged so as to illuminate.

  The glass scale 25 is formed by forming a large number of reference marks on the surface of a transparent glass substrate so as to indicate the appropriate positions of the openings of the metal mask 1, and the openings formed in the metal mask 1 at the reference marks. By aligning the portions, the metal mask 1 is provided in a flat state without distortion and sagging, and the mask portions 2 can be positioned at predetermined positions with the pitches of the plurality of mask portions 2 set to appropriate values. . FIG. 9 illustrates the relationship between the reference mark formed on the glass scale 25 and the opening formed in the mask portion 2 of the metal mask 1. As shown in FIG. 9B, a large number of openings 40 are formed in each of the plurality of mask portions 2 of the metal mask 1. The shape, size, pitch, and the like of the openings 40 are determined according to a desired vapor deposition pattern. As an example, an opening 40 having a rectangular shape as illustrated and having a width of 50 μm and a length of 150 μm is used. It is assumed that As shown in FIG. 9A, a large number of reference marks 42 are formed on the glass scale 25 used for the metal mask 1 having the openings 40, and each reference mask 42 has an opening 40. The size is made smaller both vertically and horizontally, for example, 30 μm wide and 130 μm long. As a result, in a state where the reference mask 42 and the opening 40 overlap each other with their centers aligned, the reference mask 42 and the reference mask 42 are illuminated from the lower side of the glass scale 25 with the transmission illumination device 24 (see FIG. 2). When the overlapping portion with the opening 40 is imaged from above and displayed on the monitor 43 as shown in FIG. 9C, the reference mark 42 enters the opening 40, and a rectangular bright portion outside the reference mark 42. 44 appears. It is possible to recognize that the reference mark 42 and the opening 40 are correctly overlapped by visually observing the rectangular bright portion 44 or by recognizing it by image processing.

  The reference marks 42 formed on the glass scale 25 are preferably provided so as to correspond to all the openings 40 formed in the metal mask 1, whereby the openings 40 of the mask part 2 at arbitrary positions are provided. Although the mask portion 2 can be positioned according to the reference mark 42, the present invention is not limited to this, and the reference mark 42 may be formed only in a desired region of the glass scale 25. When aligning the metal mask 1, a plurality of mask portions 2, for example, as shown in FIG. 9 (b), a plurality of mask portions 2, as shown in FIG. When the portions 2 are arranged side by side in the vertical and horizontal directions, if the mask portion 2 (the mask portion at the position indicated by A, B, C, D) located on the outermost side in the outermost row is aligned, the other mask portions Since the position 2 is often an appropriate position, a reference mark 42 may be formed in a region corresponding to the mask portions 2 so that the mask portions 2 can be aligned. That's fine. In addition, since only one opening 40 is used for alignment with respect to one mask portion 2, only one reference mark 42 is required in the region corresponding to one mask portion 2, but only one. Since it is difficult to find the position of the reference mark only by providing the reference mark 42, it is preferable to form a large number of reference marks 42 for one mask portion 2, and further, It is more preferable to form the reference mark 42 corresponding to all the openings 40 of the two mask portions 2. As described above, when the reference mark 42 is formed on the glass scale 25 so as to correspond to all the openings 40 of the mask portion 2 in the regions indicated by A, B, C, and D of the metal mask 1, In the state where the glass scale 25 is overlaid on the glass mask 25, the tension applied to each side of the metal mask 1 is adjusted, and any one opening 40 in each mask portion 2 at the positions indicated by A, B, C, D is provided. By aligning with the corresponding reference mark 42, the metal mask 1 can be stretched in a state free from distortion and slack, and each mask portion 2 can be positioned at a predetermined position.

  In FIG. 2, an X, Y, θ stage 23 supports the glass scale 25 and positions the glass scale 25 in a position close to the lower surface of the metal mask 1, and a support surface that supports the glass scale 25. (Upper surface) can be positioned in the vertical direction (X direction) and horizontal direction (Y direction) in the horizontal plane, and can also be positioned in the rotational direction (θ direction) about the vertical axis at the center. It has a function that can. With this function, the X, Y, θ stage 23 can position the supporting glass scale 25 with respect to the metal mask 1 in the XY direction and the θ direction. The X, Y, θ stage 23 used here is a small-sized support surface whose area is considerably smaller than that of the glass scale 25, and costs are reduced by using a small-sized one. For example, when the size of the glass scale is 1000 mm × 1000 mm × thickness 5 mm, the size of the support surface of the X, Y, θ stage 23 may be about 100 to 300 mm × 100 to 300 mm.

  2 and 5, the ball type support device 26 includes a ball 26a that is rotatably held and can support an object with the ball 26a. Here, the ball 26a is used for glass. It arrange | positions so that the lower surface of the scale 25 may be supported. This ball-type support device 26 is provided so as to suppress bending due to its own weight in the peripheral region of the glass scale 25 whose central region is supported by the X, Y, and θ stages 23, and the bending due to its own weight is large. Each is arranged so as to support the vicinity of the corner. By supporting the lower surface of the glass scale 25 with the ball-type support device 26, the glass scale 25 can be held in a horizontal state by suppressing the bending of the glass scale 25 due to its own weight. Further, when the glass scale 25 is supported by the ball type support device 26, the lower surface of the glass scale 25 is supported by a rotatable ball 26a. Therefore, when the glass scale 25 is moved or swung by the X, Y, θ stage 23, Smooth movement or turning is possible.

  The ball type support device 26 is provided with a height adjusting mechanism 26b capable of adjusting the height position of the ball. As the height adjusting mechanism 26b, an adjusting screw type is usually used, and it is particularly preferable to use a height adjusting mechanism using a precision screw with a small pitch so that precise adjustment is possible. By providing the height adjusting mechanism 26b as described above, the height position of the glass scale 25 supported by the ball type support device 26 can be adjusted, and the portion of the glass scale 25 supported by the ball type support device 26 can be adjusted. The height can be made to coincide with the height of the portion supported by the X, Y, θ stage 23 with high accuracy, and therefore the glass scale 25 can be held horizontally with high accuracy. The height adjustment mechanism 26b is not essential, and may be omitted, and the ball-type support device 26 may be manufactured and assembled to have a desired height. However, the height adjustment mechanism 26b is provided. In other words, the manufacturing accuracy and assembly accuracy of the ball type support device 26 may be lowered, and therefore, manufacture and assembly are facilitated.

  The glass scale 25 supported by the X, Y, θ stage 23 and the ball-type support device 26 is not in contact with the metal mask 1 immediately below the metal mask 1 stretched by the plurality of tension units 13. Are arranged so as to be very close to each other. Here, the reason why the glass scale 25 is not in contact with the metal mask 1 is to prevent the two from rubbing and scratching. This is to enable simultaneous and accurate imaging of the opening 40 of the metal mask 1. The distance between the glass scale 25 and the metal mask 1 is set so as to fall within the depth of focus of the CCD camera 30 described later, and is preferably set to about 50 to 200 μm, more preferably about 50 to 100 μm. . As described above, since the glass scale 25 is supported by the ball-type support device 26, the bending is suppressed and the glass scale 25 is kept in a horizontal state with high accuracy. The entire surface of the scale 25 is extremely uniform, and is maintained within the focal depth of the CCD camera 30 at any position.

  1 and 2, the alignment apparatus 10 further includes a moving table 28 that is held movably horizontally on a side frame 27 fixed to the support table 11, and four images that are held on the moving table 28. Means 30 are provided. The imaging means 30 is capable of simultaneously imaging the reference mark of the glass scale 25 and the opening of the metal mask 1, and a CCD camera is used in this embodiment. The CCD camera 30 has one opening of the mask portion 2 in the regions A, B, C, and D of the metal mask 1 (preferably, openings at positions close to the four corners of the region where the many mask portions 2 are arranged). And the depth of focus is determined so that the opening of the metal mask 1 and the reference mark of the glass scale 25 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 movable table 28 holding the imaging means 30 is in a standby position outside the plurality of tension units 13 and the glass scale 25 and the like. Then, the metal mask 1 is placed thereon, and the four sides thereof are gripped 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 table 28 moves above the glass scale 25 and stops at a predetermined position (see FIG. 2). Next, pressurized air is sent to driving means (air cylinder) 18 connected to each clamp 17 to move each clamp 17 in a direction away from the metal mask 1, and the metal mask 1 is moved in both vertical and horizontal directions by a number of clamps. A small tension is applied 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, imaging is started by the CCD camera 30, and an image is displayed on the monitor 43 (see FIG. 9). While confirming this, the operator adjusts the X, Y, and θ stages 23 to move the position of the glass scale 25 in the X, Y, and θ directions, and the reference mark 42 of the glass scale 25 is opened in the metal mask 1. Coarse positioning is performed on the portion 40. At this time, since the glass scale 25 is supported by the rotatable ball 26a of the ball type support device 26, the glass scale 25 can move smoothly and can be well positioned roughly. After the rough positioning, the X, Y, and θ stages 23 are fixed at the positions, and the driving force of the driving means 18 of the plurality of tension units 13 that apply tension to the metal mask 1 is confirmed while checking with the monitor 43. The tension applied to the metal mask 1 is adjusted to adjust the four openings 40 to the corresponding reference marks 42. When the four opening portions 40 coincide with the reference mark 42, the plurality of mask portions 2 formed on the metal mask 1 are respectively positioned at predetermined positions. In addition, the metal mask 1 is in a flat state without distortion and sagging, and the openings of the mask part 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 movable table 28 is returned to the standby position outside the metal mask 1, and the metal mask 1 is spot welded to the frame 3 using a laser or the like (not shown). (See reference numeral 33 in FIG. 4) and fix. 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 the configuration in which the metal mask 1 is fixed to the frame 3 with a large number of spot welds 33 is manufactured.

  In the obtained vapor deposition mask unit 8, the metal mask 1 is kept in a state where there is no distortion or sagging, and the openings of the mask part 2 are accurately aligned in parallel, and the position of each mask part is also predetermined. It is kept within the 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.

  In the above-described embodiment, the transmission illumination device 24 is provided below the glass scale 25, and the light transmitted through the glass scale 25 and the metal mask 1 is imaged by the CCD camera 30. Although the overlapping state between the opening 42 of the metal mask 1 and the opening 42 of the metal mask 1 is monitored, the imaging by the CCD camera 30 is not limited to the transmitted light from below, but may be configured to use reflected light from illumination from the surface side. In that case, it is preferable to provide a reflecting mirror below the glass scale 25 because the amount of reflected light passing through the opening 40 of the metal mask 1 can be increased. FIG. 6 shows an alignment device using the reference position indicating device 22A according to the embodiment in that case. In this reference position indicating device 22A, a reflecting mirror 35 is laminated on the lower surface of the glass scale 25, and the central region of the glass scale 25 and the reflecting mirror 35 is supported by the X, Y, θ stage 23, and the peripheral region is The lower surface of the reflecting mirror 35 is supported by the ball type support device 26. Even in this configuration, the glass scale 25 can be kept horizontal with high precision by suppressing the deflection of the glass scale 25 due to its own weight by the ball-type support device 26, and therefore, between the metal mask 1 and the glass scale 25. The gap dimension can be kept uniform over the entire surface of the glass scale 25, and the overlapping state of the reference mark 42 of the glass scale 25 and the opening 40 of the metal mask 1 is monitored by the CCD camera 30, and the position alignment of the metal mask. Can be done accurately.

  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, when adjusting the tension applied to the metal mask 1, the monitor 43 is used to determine whether or not the opening 40 of the metal mask 1 and the reference mark 42 of the glass scale 25 are correctly overlapped. However, instead of visual observation, a signal from the CCD camera 30 may be processed and determined. In the above embodiment, the CCD cameras 30 are provided at four locations. However, the present invention is not limited to this, and one or two CCD cameras 30 are used, and the CCD cameras 30 are moved to positions to be imaged. The method used may be used. However, if the CCD cameras 30 are provided at four positions as in the illustrated embodiment, the tension adjustment can be performed while monitoring the four openings 40, and the tension adjustment can be performed easily and promptly. The advantage that can be obtained. Further, in the above-described embodiment, the metal mask 1 is positioned by aligning the openings of the four mask portions 2 with the fiducial marks on the glass scale. However, the mask portions 2 used for alignment are four pieces. For example, when positioning only in the vertical direction or only in the horizontal direction of the metal mask is sufficient, the alignment may be performed using the openings of the two mask portions 2.

The schematic perspective view of the principal part of the alignment apparatus which concerns on embodiment of this invention FIG. 1 is a schematic side view showing a part of the alignment device shown in FIG. Schematic side view of the tension unit provided in 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. A schematic side view showing a ball-type support device supporting a glass scale and its periphery; The schematic side view which shows the alignment apparatus which concerns on other embodiment of this invention in part in a cross section 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 the frame (A) is a schematic plan view showing a reference mark formed on the glass scale, (b) is a schematic plan view showing an opening formed in the metal mask, and (c) is an overlapping region of the reference mark and the opening. Schematic front view showing a state where images are captured and displayed on a monitor Schematic side view showing a part of the previously developed alignment device in cross section Partial cross-sectional schematic side view showing another example of alignment device developed earlier exaggerating the deflection of the glass scale

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal mask 2 Mask part 3 Frame 4 Opening 5 Easy cutting line 8 Deposition mask unit 10 Alignment apparatus 11 Support stand 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, 22A Reference position indicating device 23 X, Y, θ stage 24 Transmission illumination device 25 Glass scale 26 Ball type support device 26a Ball 26b Height adjustment mechanism 27 Side frame 28 Moving table 30 Imaging means (CCD camera)
33 Spot weld 40 Opening 42 Reference mark 43 Monitor 44 Bright area

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 material to be measured, and X, Y holding the central area of the glass scale so that the glass scale is horizontal, A reference position indicating device comprising: a θ stage; and a ball-type support device arranged to support a lower surface of the glass scale so as to suppress bending due to its own weight in a peripheral area of the glass scale.   2. The reference position indicating device according to claim 1, wherein the ball type support device is provided so as to support the vicinity of four corners of the glass scale.   The reference position indicating device according to claim 1, wherein the ball type support device includes a height adjusting mechanism capable of adjusting a height position of a ball supporting the glass scale.   The reflecting mirror is laminated | stacked on the lower surface of the said glass scale, The said ball-type support apparatus is arrange | positioned so that the lower surface of the said reflecting mirror may be supported, The any one of Claim 1 to 3 characterized by the above-mentioned. Reference position indicating device.   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 having a large number of openings, and a plurality of openings formed in the metal mask. Among them, a glass scale having a plurality of reference marks that are formed at least at appropriate positions of the plurality of openings and having a plurality of reference marks smaller than the openings is provided, and the glass scale is stretched by the plurality of tension units. The reference position indicating device according to any one of claims 1 to 3, which is disposed so as to be positioned close to a lower surface of the metal mask, a transmission illumination device disposed below the glass scale, Arranged above the metal mask stretched by a plurality of tension units, the opening of the metal mask and the reference mark of the glass scale Metal mask position alignment device having an imaging means for imaging the portion overlapping, and an adjustable adjustment means the tension of the plurality of tension units to grant.   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 having a large number of openings, and a plurality of openings formed in the metal mask. Among them, a glass scale having a plurality of reference marks that are formed at least at appropriate positions of the plurality of openings and having a plurality of reference marks smaller than the openings is provided, and the glass scale is stretched by the plurality of tension units. 5. The reference position indicating device according to claim 4, wherein the reference position indicating device is disposed so as to be close to a lower surface of the metal mask, and is disposed above the metal mask stretched by the plurality of tension units. Imaging means for imaging an overlapping portion of the opening and the fiducial mark on the glass scale, and the plurality of tension units Metal mask position alignment device having an adjustable adjusting means Pensions.   The metal mask position alignment apparatus according to claim 5 or 6, wherein four imaging units are provided so that four openings can be simultaneously imaged.

Images