JP2006110607A - Laser beam machining apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology of performing excellent laser beam machining without generating any focal deviation by pressing a metal mask 1 against a frame 3 and tightly attaching it thereto by using a simple mechanism when performing the laser beam welding of the metal mask 1 to the frame 3. <P>SOLUTION: A laser beam irradiation lens 32 is held by an elevating/lowering stage 28 in an elevating/lowering manner, and a holding member 34 is provided on a tip portion of the laser beam irradiation lens in a jointly elevating/lowering manner. The metal mask 1 is held by the holding member 34 and tightly attached to the frame 3, and the distance of the laser beam irradiation lens 32 from the metal mask 1 is kept constant to enable excellent laser beam welding without generating any focal deviation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a laser processing apparatus that performs processing such as spot welding and drilling using a laser, and more particularly to a laser processing apparatus that is suitable for performing processing such as spot welding and drilling on a thin metal plate such as a metal mask. .

  Conventionally, vacuum vapor deposition is performed in the manufacture of an organic EL element, and a metal mask having a mask portion having a large number of fine slits 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, as the patterning has become finer and the slits formed in the mask portion have become finer and the thickness of the metal mask itself has become thinner, the metal mask is simply used in a frame-like frame. Just fixing them causes distortion and sagging in the mask part, which causes a problem that the slit accuracy cannot be maintained. Therefore, the present applicant has first developed a metal mask holding jig that can hold the metal mask in a state of being pulled in the slit direction of the mask portion with the metal mask attached to the frame (patent) Reference 1). By using this holding jig, it is possible to hold the thin line portion constituting the slit of the mask portion in a state of being pulled in the longitudinal direction, so that the slit can be held in a straight line and at a constant pitch, and high-definition patterning is possible. Is obtained.

  However, the metal mask described in Patent Document 1 has a problem that productivity is poor because only one mask portion is formed on one metal mask. In order to increase productivity, a multifaceted metal mask in which a plurality of mask portions are formed on a single metal mask may be used. However, in a multifaceted metal mask, simply holding both ends and pulling the metal mask Even if the entire width of the mask is pulled evenly, the mask portion and the non-mask portion have different rigidity, so that the mask portion is distorted and slack, a desired slit pattern cannot be obtained, and the positional accuracy of each mask portion is poor. Turned out to be. 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 for the position of each mask portion, but it is difficult to achieve such dimensional accuracy. .

  Therefore, as a result of studying to solve this problem, each of the four sides of the metal mask is gripped by a plurality of clamps, tension is applied to the metal mask by each clamp, and the tension is adjusted for each clamp. Thus, the present inventors have found that the metal mask can be made flat without wrinkles and sagging, and the slits of each mask portion can be held linearly and at a constant pitch. In addition, tension is applied to the metal mask to make it flat, and it is fixed to the frame-like frame by spot welding in that state, so that the metal mask is flattened by tension even after the clamp is removed. Therefore, it has been found that a multi-face mask can be held without distortion and sagging using a frame having a simple structure.

  By the way, when spot welding is performed on the frame in a state where tension is applied to each of the four sides of the metal mask as described above, if there is a gap between the metal mask and the frame, welding failure occurs. In order to avoid this, it is necessary to press the metal mask against the frame during welding. Therefore, as shown in FIG. 6, the metal mask 1 is placed on the frame-like frame 3 supported by the frame support 20, is gripped and pulled by the clamp 17, and tension is applied to the metal mask 1. When the metal mask 1 is spot-welded to the frame 3 in this state, the presser has a shape capable of pressing the entire region facing the frame 3 of the metal mask 1 and has a conical hole 41 formed at the spot welding position. A plate 40 is prepared, and this is pressed against the metal mask 1 by a pressing mechanism (not shown) using an air cylinder or the like to press the metal mask 1 against the frame 3. In this state, the plate moves in the XY direction. Laser irradiation is performed by laser irradiation from a laser irradiation lens 44 held by a movable table 43, and the laser irradiation lens 44 is moved along the frame 3. Tried spot welding method of moving by Nozomu pitch sequentially repeated spot welding.

However, in this method, it is necessary to prepare a presser plate that matches the shape of the frame 3, and a presser mechanism with a complicated structure is required to press the large presser plate evenly against the metal mask 1. There was a problem of becoming higher. Further, welding could not be performed on the portion where the presser plate 40 was in contact with the metal mask 1, and the degree of freedom in selecting the welding position was low. Further, when the size of the frame 3 is large, the thickness unevenness of the frame 3 increases. For example, as shown exaggeratedly in the right region of FIG. 6, when the frame 3 is thin, the focal position of the laser irradiation lens 44 is the frame position. 3 and the position shifted from the upper surface of FIG.
JP 2003-68453 A

  The present invention has been made in view of such a situation. When laser processing is performed on an object to be processed such as a metal thin plate as in the case of laser welding a metal mask to a frame, the object to be processed has a simple mechanism. It is an object of the present invention to provide a laser processing apparatus having a simple structure that can be satisfactorily used and can perform good laser processing without causing defocusing.

  In order to solve the above problems, the present invention enables a laser irradiation lens for irradiating a laser to be moved up and down by holding it on a lifting stage, and a pressing member is provided at the tip of the laser irradiation lens to be lifted and lowered together. A pressing surface for pressing the workpiece is formed at a position surrounding the laser spot by the laser irradiation lens at the tip of the pressing member, and the position of the pressing surface with respect to the laser irradiation lens is determined by the pressing surface. In this configuration, the laser irradiation lens is determined to be in a position suitable for laser processing on the processing object when the processing object is pressed. With this configuration, the workpiece can be pressed at a position surrounding the laser spot irradiation position by lowering the elevating stage and pressing the pressing surface at the tip of the pressing member against the workpiece. Positioning can be performed at a height suitable for processing, and laser processing such as spot welding can be performed satisfactorily.

  Here, it is preferable that the holding member is provided with a conical light-shielding cover portion that narrows toward the tip so as to surround the laser irradiation range from the laser irradiation lens. Leakage can be greatly prevented.

  An opening may be formed in a part of the conical cover portion formed in the holding member as necessary to avoid interference with members existing around the laser processing position, By providing the opening, even if there is any member around, laser processing near the member can be performed.

  Furthermore, when an opening is formed in the cover portion of the pressing member, it is preferable that the pressing member can be rotated with respect to the laser irradiation lens, so that in which direction the member existing around the laser irradiation position is located. Even if it exists, the opening currently formed in the cover part can be aimed at the member, and interference can be avoided. Although it is good also as a structure which rotates a pressing member manually, it is preferable to provide the rotating device which rotates a pressing member in the said raising / lowering stage because it can automate.

  In the laser processing apparatus of the present invention, by lowering the lifting stage holding the laser irradiation lens, the workpiece can be pressed at a position surrounding the laser spot irradiation position by the pressing member, and at the same time, the laser irradiation lens is moved to the laser. It can be positioned at a height suitable for processing, and laser processing such as spot welding with high quality can always be performed. Further, since the presser member only needs to be held on the lift stage holding the laser irradiation lens, a lift mechanism dedicated to the presser member is unnecessary, and compared with the case where the presser plate 40 and the presser mechanism as shown in FIG. 6 are provided. The device structure can be simplified. Further, since laser processing can be performed at an arbitrary position where the laser irradiation lens and the pressing member arranged at the tip thereof can move, an effect of increasing the degree of freedom in selecting the laser irradiation position can be obtained.

  The laser processing apparatus of the present invention can be used for laser processing on an arbitrary workpiece that needs to be pressed during laser processing, such as a thin metal plate, and as a suitable example, precision is required. The case where the metal mask used as a multi-face mask for vapor deposition for organic EL element manufacture is spot-welded to a frame-shaped frame can be mentioned. Hereinafter, a preferred embodiment of the present invention will be described taking as an example a case where a metal mask used as a multi-face mask for vapor deposition in the manufacture of organic EL elements is spot-welded to a frame. FIG. 1 is a schematic side view showing a part of a metal mask attaching apparatus provided with a laser processing apparatus according to an embodiment of the present invention, and FIG. 2 (a) is a main portion of the metal mask attaching apparatus. 2 is a schematic sectional view, FIG. 2B is a schematic side view of a part of the pressing member, and FIG. 3 is a schematic plan view showing a plurality of tension units provided in the metal mask attaching apparatus and a metal mask held by the tension unit. 4 is a schematic perspective view showing a metal mask handled by the metal mask attaching apparatus and a frame-like frame for fixing the metal mask, and FIG. 5 is a schematic perspective view of a vapor deposition mask apparatus formed by fixing the metal mask to the frame. .

  In FIG. 4, 1 is a right-sided quadrilateral metal mask used as a vapor deposition mask, and a plurality of mask portions 2 are formed side by side. 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, there are examples in which elongated slit-like openings are arranged in parallel, short openings are arranged in the vertical direction, and are arranged in parallel. Can do. Reference numeral 3 denotes a frame-like frame having a large rigidity for attaching the metal mask 1, and includes an opening 4 having a size including a region where 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. The thickness of the metal mask 1, the dimensions of the mask portion 2, the dimensions of the slits formed thereon are not particularly limited, but as a typical example, the thickness of the metal mask 1 is 30 to 200 μm. 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 arranged in parallel is 80 to 150 μm, and the like.

  1 to 3, a metal mask pasting apparatus generally indicated by reference numeral 10 includes a support base 11, and an X, Y, θ stage 12 held on the support base 11 so that an upper surface 12 a is horizontal. And a plurality of tension units 13 arranged so that tension can be applied to the upper surface 12a of the X, Y, θ stage 12 by gripping a plurality of locations 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. 2, each tension unit 13 includes a base member 15, a clamp 17 that is movably held by the base member 15 via a linear motion guide 16, and air that reciprocates the clamp 17. Drive means 18 such as a cylinder is provided. 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 understood from FIG. 3, each tension unit 13 is arranged so that each side of the metal mask 1 can be held 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.

  1 and 2, 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.

  In FIG. 1, the metal mask affixing device 10 further holds a moving table 23 held horizontally on side frames 22 provided at both ends of the support table 11, and the moving table 23 held on the 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, and a movable table 23 that can move in the vertical and horizontal directions. The held XY stage 24, an XY drive device (not shown) for moving the XY stage 24 in the X direction and the Y direction, and a laser processing device 25 provided on the XY stage 24. Etc.

  The laser processing apparatus 25 includes an elevating post 27 vertically attached to the XY stage 24, an elevating stage 28 held so as to elevate, and an elevating drive apparatus (not shown) for elevating the elevating stage 28. And a laser generator (not shown) such as a YAG laser, an optical fiber 29 connected to the laser generator, a laser 30 connected to the optical fiber 29 and directed downward in the vertical direction. As described above, the laser irradiation lens 32 attached to the elevating stage 28 and a pressing member 34 provided at the tip of the laser irradiation lens 32 so as to move up and down together with the laser irradiation lens 32 are provided.

  As can be clearly understood from FIG. 2, the pressing member 34 includes a cylindrical portion 34 a that surrounds the laser irradiation lens 32, and a conical cover portion 34 b that narrows toward the tip so as to surround the laser irradiation range from the laser irradiation lens 32. A ring-shaped pressing portion 34c at the tip (lower end), and an annular pressing surface 34d for pressing the metal mask 1 is formed on the lower surface of the pressing portion 34c. The inner diameter of the pressing surface 34d is set to a small diameter in a range that does not interfere with the spot of the laser 30. Thus, the metal mask 1 can be pressed near the spot of the laser 30 and at a position surrounding the spot. Here, the position of the pressing surface 34d of the pressing member 34 is such that the laser irradiation lens 32 is suitable for laser processing on the processing object when the lifting stage 28 is lowered and the processing object (metal mask 1) is pressed by the pressing surface 34d. That is, the focal position of the laser 30 is determined to be the contact surface between the metal mask 1 and the frame 3.

  The pressing member 34 is made of a light-shielding metal material, and prevents the laser 30 from leaking to the surroundings. The laser irradiation lens 32 is moved to the vicinity of the clamp 17 on the cover portion 34 b of the holding member 34 so that the cover portion 34 b does not interfere with the clamp 17 when spot welding the metal mask 1 near the clamp 17. , An opening 36 is provided. It is preferable that the size of the opening 36 be as small as possible without interfering with the clamp 17 because the amount of leakage to the periphery of the laser 30 can be reduced. The pressing member 34 is disposed concentrically with the laser irradiation lens 32 and is attached to the elevating stage 28 so as to be rotatable via a bearing 39. Further, the elevating stage 28 is provided with a rotating device 37 including a motor 37a for rotating the pressing member 34 to a desired angular position, pulleys 37b and 37c, a belt 37d, and the like. The rotating device 37 is not limited to the structure shown in the figure, and may be an arbitrary mechanism that can rotate the pressing member 34 to a desired rotation position.

  Next, a metal mask pasting operation by the metal mask pasting 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 laser processing device 25 is in the standby position outside the X, Y, θ stage 12, and then, The metal mask 1 is placed thereon, and the four sides thereof are held by the clamps 17 of the plurality of tension units 13. This state is shown in FIG. 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. Tension is applied and the metal mask 1 is stretched, and the metal mask 1 is positioned by the X, Y, and θ stages 12 as necessary. Thereafter, the tension applied to each metal mask 1 is adjusted by adjusting the tension force of each tension unit 13, and the metal mask 1 is pulled flat in a flat state without any distortion or sagging and in parallel. The positions of the mask portions 2 (the pitch between the mask portions) are also adjusted while maintaining the aligned state.

  Next, the moving base 23 moves above the metal mask 1 in a state of being stretched by a plurality of tension units 13 and stops. Next, the XY stage 24 positions the laser irradiation lens 32 directly above the position to be spot welded first (for example, the position indicated by point A in FIG. 3), and the rotating device 37 moves the presser member 34 to the position. The formed opening 36 is rotated so as to be a position facing the direction of the clamp 17 adjacent to the position to be spot welded. Next, when the elevating stage 28 is lowered to lower the laser irradiation lens 32 and the pressing member 34 and the pressing surface 34d at the lower end of the pressing member 34 presses the metal mask 1 against the frame 3, the laser irradiation lens 28 stops at that position. 32 performs spot welding by irradiating the laser 30 (see FIG. 2) to form a spot weld 38 (see FIG. 3). At this time, since the presser member 34 presses the metal mask 1 against the frame 3, both are kept in close contact with each other, and good spot welding is performed. Even if the thickness of the frame 3 is uneven, the focal position of the laser irradiation lens 32 coincides with the contact surface between the metal mask 1 and the frame 3 when the pressing member 34 presses the metal mask 1 against the frame 3. Therefore, good spot welding is performed also in this respect. Further, since most of the periphery of the laser 30 is covered with the pressing member 34 when the laser is irradiated, there is little leakage to the periphery of the laser, and there is almost no problem even if it is visually observed by the operator.

  When the spot welding by the first laser irradiation is finished, the elevating stage 34 is moved up, and then the XY stage 24 sets the true position of the laser irradiation lens 32 and the next spot welding position (for example, point B in FIG. 3). Positioned above, spot welding is performed as described above. Thereafter, the same operation is repeated, and spot welding is successively performed along one side of the metal mask 1. When spot welding on one side is completed, the XY stage 24 positions the laser irradiation lens 32 directly above the position to be spot welded at the beginning of the next side, and the rotating device 37 moves the presser member 34 to 90. Rotate to direct opening 36 toward clamp 17 located on that side. After that, spot welding is performed one after another in the same procedure as described above, and when spot welding on that side is completed, spot welding on the next side is further performed. In this way, the four sides of the metal mask 1 are fixed to the frame 3 by a number of spot welds 38. 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. 5, it is possible to manufacture the vapor deposition mask device 8 having a configuration in which the metal mask 1 is fixed to the frame 3 with a large number of spot welds 38.

  In the vapor deposition mask device 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, and the position of each mask part is also It is kept within a predetermined dimensional accuracy. Thus, by carrying out vapor deposition using the vapor deposition mask device 8, it is possible to accurately carry out vapor deposition of a fine pattern with multiple faces.

  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, the holding member 34 is provided with the opening 36 so as not to interfere with the clamp 17. However, when spot welding is performed at a position where the holding member 34 does not interfere with the clamp 17 even if the opening 36 is not provided. The opening 36 may not be formed. If the opening 36 is not provided, the entire area around the laser 30 can be covered with the pressing member 34, so that the leakage of the laser 30 can be prevented more reliably, and the operator may accidentally look directly at the laser 30 and hurt his eyes. Can be prevented. Furthermore, in the above-described embodiment, the case of spot welding has been described. However, the present invention is not limited to spot welding, but can be applied to the case where machining such as drilling using a laser is performed.

1 is a schematic side view showing a part of a metal mask attaching apparatus provided with a laser processing apparatus according to an embodiment of the present invention in cross section. (A) is schematic sectional drawing of the principal part of the metal mask sticking apparatus shown in FIG. 1, (b) is a schematic side view of a part of pressing member. FIG. 1 is a schematic plan view showing a plurality of tension units provided in the metal mask attaching apparatus shown in FIG. 1 and a metal mask held by the tension units. The schematic perspective view which shows the metal mask handled with the metal mask sticking apparatus shown in FIG. 1, and the frame-shaped frame which fixes it Schematic perspective view of a vapor deposition mask device formed by fixing a metal mask to a frame Schematic cross-sectional view explaining the state where a metal mask is pressed against the frame with a presser plate and laser welding is performed

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal mask 2 Mask part 3 Frame 4 Opening 5 Easy cutting line 8 Deposition mask apparatus 10 Metal mask sticking apparatus 11 Support stand 12 X, Y, (theta) stage 13 Tension unit 15 Base member 16 Direct motion guide 17 Clamp 17a Fixing claw 17b Movable claw 18 Drive means (air cylinder)
20 Frame support 22 Side frame 23 Moving table 24 XY stage 25 Laser processing device 27 Lifting post 28 Lifting stage 29 Optical fiber 30 Laser 32 Laser irradiation lens 34 Pressing member 34a Cylindrical portion 34b Cover portion 34c Pressing portion 34d Pressing surface 36 Opening 37 Rotating device 38 Spot weld 39 Bearing

Claims (5)

  A laser irradiation lens for irradiating a laser; an elevating stage for holding and raising the laser irradiation lens; and a pressing member provided at the tip of the laser irradiation lens so as to move up and down together with the laser irradiation lens. The pressing member has a pressing surface for pressing the workpiece at a position surrounding the laser spot by the laser irradiation lens, and the laser irradiation is performed when the workpiece is pressed by the pressing surface. The laser processing apparatus characterized in that the position of the pressing surface with respect to the laser irradiation lens is determined so that the lens is in a position suitable for laser processing on the workpiece.   The laser processing apparatus according to claim 1, wherein the pressing member includes a conical light-shielding cover portion that narrows toward a tip so as to surround a laser irradiation range from the laser irradiation lens.   The laser processing apparatus according to claim 2, wherein an opening is formed in a part of the conical cover portion formed in the pressing member.   The laser processing apparatus according to claim 3, wherein the pressing member is rotatable with respect to the laser irradiation lens so that an orientation of an opening formed in the cover portion can be changed.   The laser processing apparatus according to claim 4, wherein a rotating device that rotates the pressing member is provided on the elevating stage.

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