JP2010215981A - Mask cleaning device for organic el, apparatus for manufacturing display for organic el, display for organic el, and mask cleaning method for organic el - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a high degree of cleaning while removing a vapor deposition substance in a complete non-contact state to a substrate when cleaning is performed to remove the vapor deposition substance sticking to a mask for an organic EL. <P>SOLUTION: A mask cleaning device for an organic EL is used for removing a vapor deposition substance 61 sticking to a mask 1 for the organic EL, and includes: a mask lifting unit 42 for holding the mask 1 for the organic EL in a standing state; a laser scanning part 11 for scanning a laser light to a portion or the whole area of the mask 1 for the organic EL from a horizontal direction; an air supply nozzle 53 for forming an air flow AF directed to the scanning surface 1S side from the rear surface 1R side in each opening part 3 of the mask 1; and a suction nozzle 63 which is arranged at a part lower than the laser light scanning position and has a suction slit 62S directed obliquely upward to suck in a released substance 62 scattered from the mask 1 for the organic EL during cleaning by the laser scanning part 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an organic EL mask cleaning device that performs laser cleaning by scanning a laser beam, an organic EL display manufacturing device, an organic EL display, and an organic EL mask cleaning method.

  An organic EL (Electro Luminescence) display is used as a low power consumption, lightweight, and thin image display device that does not require a backlight. As its structure, an organic EL thin film layer is laminated on a transparent glass substrate, and the organic EL thin film layer adopts a structure in which a light emitting layer is sandwiched between an anode layer and a cathode layer. The light emitting layer is often formed by vapor-depositing an organic material on a glass substrate to form a thin film, and the region of each pixel constituting the display is divided into three to deposit organic materials of three colors RGB. . Therefore, vapor deposition is performed using an organic EL mask (shadow mask) in which a large number of openings are formed in order to deposit different color organic materials (organic dye materials) in the three regions of each pixel.

  When performing the vapor deposition process, the organic material adheres not only to the glass substrate but also to the organic EL mask. Since the mask for organic EL is not used only for one vapor deposition process but is used repeatedly, if the vapor deposition material adheres to the mask for organic EL when performing the next vapor deposition process, the vapor deposition material becomes glass. There is a possibility of falling on the substrate and causing it to foul. In addition, an organic material is deposited on edge portions of the openings formed in the organic EL mask so that the area of the openings is partially or entirely blocked. Of course, if the entire area of the opening is blocked, or even if the area of the opening changes due to partial blocking, the deposition accuracy when using the organic EL mask is significantly reduced and it can be used. Is not. Therefore, the organic EL mask is periodically cleaned (preferably after completion of one vapor deposition process) to remove the vapor deposition material.

  As cleaning of the organic EL mask, wet cleaning using a surfactant or the like is mainly performed. Wet cleaning is cleaning performed by supplying a liquid to the organic EL mask. However, the organic EL mask to be cleaned is an ultrathin metal plate on the order of microns (several tens of microns), and a large amount of damage such as distortion or deformation is caused to the organic EL mask by the action of liquid pressure during wet cleaning. Given. In addition, when wet cleaning is performed using chemicals such as surfactants, a chemical solution supply mechanism and a drainage treatment mechanism for processing used chemicals (drainage) are required, which complicates the mechanism and causes environmental pollution due to drainage. There is also a problem.

  On the other hand, Patent Document 1 discloses a technique relating to cleaning (laser cleaning) performed by irradiating an organic EL mask with laser light as cleaning without using a chemical solution for wet cleaning. By irradiating the metal organic EL mask with laser light, a peeling force is applied between the organic EL mask and the organic material. The technique of Patent Document 1 is to perform cleaning by removing the organic material from the organic EL mask by this peeling force.

  In the technique of this Patent Document 1, the organic material adhered to the organic EL mask by irradiating the laser beam is peeled off. However, in order to prevent contamination in the tank for cleaning or the atmosphere, the organic material after peeling is removed. Is not separated from the organic EL mask. For this reason, in order to remove the organic material after peeling, an adhesive film is used. This film has an adhesive force to transfer the peeled organic material. The film is attached to the organic EL mask and irradiated with laser light to remove the vapor-deposited material peeled from the organic EL mask. It is transferred to film. And the cleaning process is completed by peeling the film which the organic material transcribe | transferred from the mask for organic EL.

JP 2006-169573 A

  By the way, the organic EL mask is an extremely thin metal plate, and even if an extremely small force is applied, the organic EL mask is distorted and deformed, and is damaged. Moreover, with the recent increase in the screen size of organic EL displays, the size of organic EL masks has increased, and handling of large and extremely thin organic EL masks must be extremely delicate. In the technique of Patent Document 1, since peeling of the film from the organic EL mask is performed against the adhesive force, excessive peeling force acts on the organic EL mask. As a result, the organic EL mask is distorted, warped, etc., and is seriously damaged.

  That is, in Patent Document 1, although the organic material is peeled from the organic EL mask by laser light, the film is brought into contact with the organic EL mask in order to remove the peeled organic material. Not complete. Moreover, although the raw material (polyethylene terephthalate) which permeate | transmits a laser beam is used as a film, even if it uses a transparent film, attenuation | damping will arise in a laser beam. For this reason, there is a possibility that sufficient energy cannot be given to the organic EL mask and a high cleaning effect cannot be exhibited. And since the mechanism for exclusive use for sticking and peeling of a film is required, there exists a problem that a mechanism becomes complicated and an apparatus becomes large. In particular, if the organic EL mask becomes a large size, the size of the film also increases, and problems such as a complicated mechanism and a large apparatus become more prominent.

  For this reason, it is desirable to clean the organic EL mask in a completely non-contact state without using a film. When laser cleaning is performed on the surface of the organic EL mask, the peeling force acts on the vapor deposition material, and the vapor deposition material is decomposed by the energy of the laser beam, so that the organic EL mask becomes free material such as powder or gas. Try to scatter upwards from the surface. If the aforementioned film is attached to the organic EL mask, the free substance is transferred to the film. However, if the film is not used from the viewpoint of avoiding damage to the organic EL mask, the scattered free substance It falls on the organic EL mask by gravity and reattaches. For this reason, the degree of cleaning of the organic EL mask is low despite the laser cleaning, and free substances are formed on the back surface of the organic EL mask from the openings formed in the organic EL mask. It wraps around and becomes attached. If a free substance adheres to the back surface, when a new substrate is deposited, it is transferred to the substrate and contaminated, resulting in a decrease in the degree of cleaning.

  Further, in the method of performing laser cleaning from above with the organic EL mask arranged in a horizontal state as in Patent Document 1, there is a possibility that the ultra-thin organic EL mask is bent. As mentioned above, the mask metal plate tends to increase in weight as the mask size increases, so it is extremely difficult to maintain a micron-sized organic EL mask in a flat state, and it is placed in a horizontal state. When doing so, a large deflection occurs. When the organic EL mask bends, a large difference occurs in the height position between the end position and the center position of the organic EL mask, and a deviation occurs from the focal position from the laser light source. For this reason, the intensity | strength of the laser beam in the site | part in which bending has arisen becomes weak, and the cleaning degree of the said site | part falls significantly.

  Therefore, the present invention aims to obtain a high degree of cleaning while removing the deposit in a completely non-contact state with respect to the substrate when performing cleaning for removing the deposit adhering to the organic EL mask. To do.

  In order to solve the above problems, an organic EL mask cleaning apparatus according to claim 1 of the present invention is an organic EL mask cleaning apparatus for removing a vapor deposition material attached to an organic EL mask, and the organic EL mask. A mask holding means for holding in a standing state, a laser cleaning means for scanning a laser beam from a horizontal direction with respect to a part or all of the region of the organic EL mask, and a back surface at the opening of the organic EL mask An air flow forming means for forming an air flow from the side toward the scanning surface side, and a free substance scattered from the organic EL mask by the laser cleaning means disposed below the scanning position of the laser beam. And suction means having an opening for performing suction upward obliquely upward.

  According to this organic EL mask cleaning device, since the air flow is formed from the back side of the organic EL mask held in an upright state, the free substance that has been decomposed and scattered is deposited for the organic EL. It will not enter the opening of the mask. The free substance is forcibly sucked by the suction means. As a result, free substances are not reattached to the organic EL mask, and a high degree of cleaning can be obtained. Moreover, since the organic EL mask is held in an upright state, the mask does not bend and cleaning can be performed with a high degree of cleaning. Further, since the free substance scattered by scanning the laser beam is sucked, cleaning can be performed completely in a non-contact manner, and the organic EL mask is not damaged.

  The organic EL mask cleaning apparatus according to claim 2 of the present invention is characterized in that, in the organic EL mask cleaning apparatus according to claim 1, the suction means operates following the scanning portion of the laser beam.

  According to this organic EL mask cleaning apparatus, the suction means operates following the scanning portion of the laser beam, so that the suction means can be disposed at a position closest to the scanning portion of the laser. By forcibly aspirating the free substance scattered from the organic EL mask with the suction means provided at the nearest position, the free substance can be reliably recovered before being dispersed over a wide range. Since the scanning part and the suction part always maintain a constant distance by the follow-up operation of the suction part, there is no difference in the cleaning degree depending on the part of the organic EL mask so that a high and uniform cleaning degree can be obtained. Become.

  The organic EL mask cleaning device according to claim 3 of the present invention is the organic EL mask cleaning device according to claim 1, wherein the wind pressure sucked by the suction means is larger than the wind pressure of the air flow of the air flow forming means. It is characterized by that.

  According to this organic EL mask cleaning apparatus, since suction can be performed with a large wind pressure, it becomes possible to efficiently suck free substances, and even if vapor deposition substances remain in the organic EL mask, suction air Since the wind pressure can be increased to some extent, it can be sucked off as if it was peeled off. Even if the wind pressure from the suction means is increased, the suction wind acts on the organic EL mask from an oblique direction, so that it does not bend so much.

  The organic EL mask cleaning device according to claim 4 of the present invention is the organic EL mask cleaning device according to claim 1, wherein the air flow forming means forms the air flow by ion wind. .

  According to this organic EL mask cleaning apparatus, the air flow formed by the air flow forming means is ionized. The scattered free substance is positively or negatively charged by static electricity. By making the air flow from the back side toward the scanning side into a weak ionic wind having the opposite characteristics, it can be released from the opening of the organic EL mask. The released ionic wind can efficiently lead the free substance to the suction means.

  The organic EL mask cleaning device according to a fifth aspect of the present invention is the organic EL mask cleaning device according to the second aspect, wherein the laser scanning means is arranged in a horizontal direction from an uppermost portion of a region where the organic EL mask is cleaned. 1 line is scanned, the one line scan is sequentially directed downward, the air flow forming means and the suction means are provided with a length corresponding to the one line, and one line of the laser scanning means is provided. It is characterized in that it is sequentially lowered downward for every minute scan.

  According to this organic EL mask cleaning apparatus, by scanning one horizontal line sequentially downward, even if free substances scattered in the upper cleaning are reattached to the organic EL mask, The adhering part is a part where laser cleaning is performed later, and a high degree of cleaning can be obtained.

  The organic EL mask cleaning device according to claim 6 of the present invention is the organic EL mask cleaning device according to claim 1, wherein the mask holding means holds the organic EL mask in a state slightly inclined from a vertical direction. It is characterized by being.

  According to this organic EL mask cleaning device, since the organic EL mask is held slightly tilted from the vertical direction, free substances are less likely to reattach to the organic EL mask than when held in the vertical direction. Become.

  An organic EL display manufacturing apparatus according to a seventh aspect of the present invention includes the organic EL mask cleaning apparatus according to any one of the first to sixth aspects. An organic EL display according to an eighth aspect of the present invention is manufactured by the apparatus for manufacturing an organic EL display according to the seventh aspect.

  The organic EL mask cleaning method according to claim 9 of the present invention is an organic EL mask cleaning method for removing vapor deposition substances adhering to the organic EL mask, and holds the organic EL mask in an upright state. When a laser beam is scanned from a horizontal direction with respect to a part or all of the region of the organic EL mask, an air flow is formed from the back surface side to the scanning surface side in the opening of the organic EL mask. The free material scattered from the organic EL mask is sucked by the cleaning by the laser cleaning to the suction means arranged below the scanning position of the laser beam.

  In the present invention, since an air flow is formed from the back side with respect to the organic EL mask held in a vertical state, free substances adhere to the back side during laser cleaning. There is nothing. And since the free substance which is scattered and falls is forcibly sucked by the suction means, it is possible to prevent reattachment to the organic EL mask without diffusing the free substance, and to obtain a high degree of cleaning. become. Since the organic EL mask is held in an upright state, it is possible to irradiate all areas with laser light of uniform intensity without any bending, and to perform cleaning with a high degree of uniform cleaning. become able to. Since the organic EL mask is subjected to laser cleaning and the scattered free substance is removed by suction, it is possible to completely remove the vapor deposition substance in a non-contact state.

It is the top view and sectional drawing of a mask for organic EL. It is an external view of the mask cleaning apparatus for organic EL. It is a front view of a raising / lowering mechanism. It is a side view of the organic EL mask cleaning device. It is explanatory drawing of the state which forms the airflow from an air supply nozzle and is attracting | sucking the free substance from a suction nozzle.

  Hereinafter, embodiments of the present invention will be described. FIG. 1 shows an organic EL mask 1 to be cleaned by the organic EL mask cleaning apparatus of the present invention. FIGS. 1A and 1B are a plan view and a sectional view, respectively. ing. In order to deposit a vapor deposition substance with high accuracy on a glass substrate constituting an organic EL display, the vapor deposition substance (organic material) is accurately formed in a predetermined region by setting the thickness of the organic EL mask 1 to a micron order. Will be able to. On the other hand, with the recent increase in the screen size of the organic EL display, the glass substrate has also become a large size (for example, 1500 × 1800 mm), and the size of the organic EL mask 1 has also increased. Accordingly, the ultra-thin and large-sized organic EL mask 1 cannot maintain a flat shape alone, and a frame-shaped mask frame 2 as a reinforcing frame is attached to the outer peripheral portion in order to provide shape retention. It is composed. It should be noted that any means other than the mask frame 2 may be used as long as it has shape retention.

  The organic EL mask 1 is a metal mask plate (shadow mask) in which a large number of regularly arranged openings 3 are formed from a metal. Various metals can be used for the organic EL mask 1, but an alloy of cobalt and nickel is applied here. The organic EL mask 1 is configured to deposit a deposition material from an evaporation source in a state of being in close contact with the glass substrate in a deposition apparatus (not shown) that deposits an organic material of a light emitting layer. There are various kinds of deposition materials for the light emitting layer, and for example, an organometallic complex such as an aluminum complex (tris aluminum: Alq) can be applied. Note that an organic compound other than an organometallic complex (whether or not a metal is contained) may be applied as a deposition material. The vapor deposition material evaporated from the evaporation source is deposited on the glass substrate from the portion where the opening 3 of the organic EL mask 1 is formed. Thereby, it becomes possible to form a vapor deposition material as a light emitting layer in a region corresponding to a pixel.

  During vapor deposition, the vapor deposition material adheres not only to the glass substrate but also to the organic EL mask 1. Therefore, laser cleaning of the organic EL mask 1 is performed using the following organic EL mask cleaning device. Laser cleaning is one type of dry cleaning, in which the deposition material is removed from the organic EL mask 1 by irradiating laser light, and cleaning is performed. In FIG. 1A, the organic EL mask 1 is divided into six regions (areas A1 to A6), which will be described later.

  FIG. 2 shows the appearance of the organic EL mask cleaning apparatus. This organic EL mask cleaning apparatus is schematically configured to include a mask supply unit 10, a laser scanning unit 11, and an elevating mechanism 12, and is installed in a predetermined cleaning chamber. The mask supply unit 10 includes a base 21, a table fixing column 22, a standing table 23, and a mask holding member 24 and is schematically configured. The mask supply unit 10 is transported with an organic EL mask 1 to which a vapor deposition substance is attached through a vapor deposition step (a step of depositing an organic material on the glass substrate). The base 21 is a base of the mask supply unit 10, and four table fixing columns 22 are erected on the base 21, and an upright table 23 is in contact with the upper surface of each table fixing column 22. The table fixing column 22 maintains the standing table 23 in a horizontal posture.

  The standing table 23 includes a rotation shaft 25 and rotates 90 degrees about the rotation shaft 25. In the state of FIG. 2, the standing table 23 is in a horizontal state, and is brought up by rotating 90 degrees. A mask holding member 24 is attached to the standing table 23 so as to be able to contact and separate, and the organic EL mask 1 is mounted on the mask holding member 24. The mask holding member 24 has a frame shape substantially the same as that of the mask frame 2, and an area corresponding to the organic EL mask 1 is open. The mask holding member 24 holds the portion of the mask frame 2 attached to the outer periphery of the organic EL mask 1 by appropriate holding means (clamp, chuck, vacuum suction, etc.).

  The laser scanning unit 11 includes a laser optical system 31 and an optical system moving unit 32 and is schematically configured. The laser optical system 31 includes a laser light source 33 and a galvanometer mirror 34. The laser light source 33 oscillates laser light having a predetermined wavelength, and oscillates laser light having such a wavelength that the metal material of the organic EL mask 1 reacts. When the organic EL mask 1 is an alloy of cobalt and nickel, it is set so as to oscillate a laser beam in the vicinity of 532 nm, which is a wavelength region in which the alloy reacts. When the organic EL mask 1 is made of another metal material, a laser beam that reacts with the material is oscillated.

  A galvanometer mirror 34 is disposed at the incident position of the laser light oscillated from the laser light source 33. The galvanometer mirror 34 is a reflection mirror that converts the optical path of the incident laser light, and is arranged so as to form an angle of 45 degrees with respect to the incident laser light. For this reason, the optical path of the laser beam reflected by the galvanometer mirror 34 is converted by 90 degrees toward the organic EL mask 1. The galvanometer mirror 34 is finely oscillated by a driving device (not shown), and this oscillation slightly changes the reflection angle of the laser light at high speed. Here, it is assumed to vibrate so as to change the reflection angle in the Y direction and the Z direction in FIG. As a result, the laser light can be scanned with respect to predetermined regions in the Y direction and the Z direction of the organic EL mask 1. The laser light oscillated from the laser light source 33 is finally focused on the scanning surface (the surface on which the vapor deposition material is attached) of the organic EL mask 1. For this reason, the laser light oscillated from the laser light source 33. Is converged light or is focused using an optical component such as an objective lens.

  The optical system moving unit 32 includes a base 35, a rail mounting table 36, a Y-axis rail 37, and a Y-axis moving table 38, and is schematically configured. The base 35 is a base, and a rail mounting table 36 is installed on the base 35. A Y-axis rail 37 is installed on the upper surface of the rail mounting table 36. The Y-axis rail 37 is a rail extended in the Y-axis direction in FIG. 2, and a Y-axis moving table 38 is provided so as to slide on the Y-axis rail 37. A laser optical system 31 is mounted on the Y-axis moving table 38, and by moving along the Y-axis rail 37, the entire laser optical system 31 can be positioned at an arbitrary position in the Y-axis direction. It has become. For this reason, a drive mechanism (such as a motor or a ball screw) (not shown) is attached to the Y-axis moving table 38, and the laser optical system 31 is driven to reciprocate at a predetermined timing as will be described later.

  Next, the lifting mechanism 12 will be described. As shown in FIG. 2, the elevating mechanism 12 is disposed so as to be sandwiched between the mask supply unit 10 and the laser scanning unit 11. FIG. 3 is a front view of the elevating mechanism 12 that holds the organic EL mask 1 in an upright state. As shown in FIG. 3, the elevating mechanism 12 has two support columns 41, 41 standing at positions separated in the Y-axis direction, and the two elevating systems perform the elevating operation. Among them, one lifting system is a mask lifting unit 42 that moves the organic EL mask 1 up and down.

  The mask raising / lowering unit 42 is means for holding the mask holding member 24 and the organic EL mask 1 held by the mask holding member 24 in an upright state, and moves up and down inside the columns 41, 41. That is, the mask holding means for holding the organic EL mask 1 in an upright state includes the mask holding member 24 and the mask lifting / lowering unit 42. In order for the mask elevating unit 42 to hold the mask holding member 24 (or the organic EL mask 1), an appropriate means such as a chuck or a clamp can be used. Here, a clamp member is applied as the mask lifting unit, and the clamp member holds the mask holding member 24. And this clamp member itself shall raise / lower. In this case, the mask holding means for holding the organic EL mask 1 in an upright state is constituted by the mask holding member 24 and the mask lifting / lowering unit 42. Of course, as long as the organic EL mask 1 can be held in an upright state, the organic EL mask 1 or the mask holding member 24 may be held using any means such as a chuck or vacuum suction. The mask holding member 24 and the standing table 23 can be brought into and out of contact with each other. By separating the mask holding member 24 from the standing table 23, the organic EL mask 1 can be moved up and down by the mask lifting unit 42. .

  Another lifting system that moves up and down the column 41 is a nozzle lifting unit 51. The nozzle lifting / lowering unit 51 includes a suction nozzle 52, an air supply nozzle 53, and a connecting member 54. The suction nozzle 52 is an elongated nozzle having a length corresponding to the interval between the columns 41 and 41, and has a suction slit 52S as shown in FIG. The suction slit 52 </ b> S has a length equal to or greater than the width of the organic EL mask 1, and the slit is opened obliquely upward toward the organic EL mask 1. Accordingly, the suction nozzle 52 sucks outside air obliquely above itself. The suction nozzle 52 always performs suction.

  On the other hand, the air supply nozzle 53 also has an air supply slit 53 </ b> S, but sends out a much weaker air flow than the suction nozzle 52. The air supply nozzle 53 is not for blowing air, but rather for forming an air flow that hardly acts on the wind pressure toward the organic EL mask 1. Unlike the suction slit 52S, the air supply slit 53S is opened so as to be orthogonal to the organic EL mask 1 (that is, opened in the normal direction of the organic EL mask 1). For this reason, the airflow from the air supply slit 53S is sent out toward the organic EL mask 1 so as to be orthogonal. Further, the opening area of the air supply slit 53S is made larger than the opening area of the suction slit 52S. Thereby, a weak air flow can be formed over a wide range. As with the suction nozzle 52, the air supply nozzle 53 always sends out air.

  Here, a weak air flow sent out from the air supply nozzle 53 is used as an ion wind that excites ion migration caused by discharge. The ionic wind forms an electric field in the air and directly accelerates the charged particles, thereby generating wind generated by the interaction between the charged particles and air molecules present in the space. By making the air flow into an ionic wind, the air flow itself can have a positive or negative polarity.

  As shown in FIGS. 2 and 4, the suction nozzle 52 and the air supply nozzle 53 are integrally configured by a connecting member 54, and the suction nozzle 52 is located immediately below the air supply nozzle 53 as a positional relationship in the Z direction. Is located. The connecting member 54 moves up or down along the outer periphery of each column 41 by a driving mechanism such as a motor or a ball screw (not shown). As shown also in FIG. 3, the suction nozzle 52 is integrally connected by a connecting member 54 so as to be at a position lower than the height of the air supply nozzle 53.

  The operation in the above configuration will be described. First, the organic EL mask 1 to which the vapor deposition material is adhered is carried in through the vapor deposition step, and the mask frame 2 that holds the organic EL mask 1 is held by the mask holding member 24. The solid line in FIG. 4 shows this state. The upright table 23 is turned upright by rotating 90 degrees around the rotary shaft 25 and is fixedly held by the mask elevating unit 42 (the raised state is indicated by a broken line). In this state, the mask holding member 24 is held by the mask lifting / lowering unit 42 so that the organic EL mask 1 is held in a standing state. Then, the connection between the mask holding member 24 and the standing table 23 is disconnected, and the standing table 23 is rotated 90 degrees to return to the horizontal state again.

  In parallel with the operation of returning the standing table 23 to the horizontal state or after the completion of this operation, the mask elevating unit 42 is lowered. The lowered position at this time is lowered so that the uppermost end of the organic EL mask 1 is positioned lower than the laser optical system 31. Then, the mask elevating unit 42 is moved up a predetermined distance every predetermined time so that the organic EL mask 1 is positioned in front of the laser optical system 31 and the laser light is scanned on the organic EL mask 1 to perform laser cleaning. Do.

  Here, laser cleaning will be described. The laser light oscillated from the laser light source 33 has such a wavelength that the metal material of the organic EL mask 1 reacts. When the organic EL mask 1 is an alloy of cobalt and nickel, the wavelength is 532 nm. A laser beam having a wavelength of is oscillated. For this reason, when the laser beam is focused on the scanning surface of the organic EL mask 1, the scanning surface of the organic EL mask 1 undergoes a large thermal expansion. Does not expand. Thereby, decomposition energy acts on the deposited vapor deposition material due to a difference in thermal expansion. By the action of the decomposition energy, the vapor deposition material adhering in the form of a film on the scanning surface is decomposed into fine particles and becomes a free material. This free substance is an extremely fine powder or gas having almost no mass, and is scattered from the scanning surface of the organic EL mask 1 when the vapor deposition substance is decomposed. In this respect, it is not necessary to set the intensity of the laser beam excessively high, as long as the deposited vapor deposition material is decomposed and scattered, and the damage to the organic EL mask 1 is suppressed. It is not necessary to give such a strength that the free substance is scattered from the scanning surface vigorously. Specifically, it is sufficient that the suctioning air is sucked by separating the free substance from the scanning surface.

  The laser beam is focused with a very small spot diameter on the scanning surface of the organic EL mask 1. Then, scanning is performed by the galvanometer mirror 34 changing the focal position in the Y direction and the Z direction. At this time, since a predetermined region in the Y direction and the Z direction is scanned, the optical path length changes due to a large difference in incident angle within the region. If the optical path length changes greatly, the focal position in the optical axis direction shifts, and laser light cannot be incident on the organic EL mask 1 with a predetermined intensity. Therefore, the large-sized organic EL mask 1 is divided into six regions (areas A1 to A6) for scanning as shown in FIG. By dividing into small regions, the difference in incident angle does not occur so much and the optical path length does not change so much. If the organic EL mask 1 is small, it is not necessary to divide the area. If the mask is very large, it may be divided into more areas.

  First, the area A1 is scanned first. For this purpose, the position adjustment is performed so that the reflection position on the galvano mirror 34 (the point where the laser light is reflected on the galvano mirror 34) and the center position of the area A1 coincide in the Y direction and the Z direction. For this purpose, the mask lifting unit 42 performs position adjustment in the Z direction, and the optical system moving unit 32 performs position adjustment in the Y direction. First, the mask elevating unit 42 is raised from the lower position so that the intermediate position of the area A1 in the Z direction matches the reflection position on the galvano mirror 34. Thereby, the position adjustment in the Z direction is completed. Next, the Y-axis movement table 38 of the optical system moving unit 32 is moved along the Y-axis rail 37 so that the intermediate position of the area A1 in the Y direction matches the reflection position on the galvano mirror 34.

  As described above, the reflection position of the laser beam and the center position of the area A1 coincide in the Y direction and the Z direction. Thereby, when the laser beam reflected by the galvanometer mirror 34 is incident on the center position of the area A1, it can be incident at an angle of 90 degrees.

  After the position adjustment, the area A1 is first scanned in the Y direction for one line from the top end. For this purpose, the galvanometer mirror 34 is minutely vibrated. Then, after the scanning for one line is completed, the scanning for one line is performed again while shifting by one line downward in the Z direction. At this time, the scanning direction in the Y direction is opposite to the scanning for the immediately preceding line, that is, the scanning is performed so as to reciprocate. Thereafter, the scanning in the Y direction is sequentially performed while shifting downward in the Z direction for each line, and after the scanning for the lowermost one line in the area A1, the laser cleaning of the area A1 is completed.

  In the present invention, laser beam scanning is performed while forming suction air and airflow. For this purpose, the suction nozzle 52 and the air supply nozzle 53 are lowered while following the scanning of the laser beam. The nozzle lifting / lowering unit 51 stands by at the uppermost position in the Z direction until the mask lifting / lowering unit 42 holds the mask holding member 24, and supplies air to the uppermost end of the area A1 before laser cleaning starts. It descends until the nozzle 53 is located.

  In FIG. 5, when the laser beam L is incident on the organic EL mask 1, the vapor deposition material 61 adhering to the scanning surface 1 </ b> S due to thermal expansion is decomposed to become extremely small free materials 62. Spatters away from 1S. Gravity acts on the scattered free substance 62, so it tries to fall at a position away from the scanning surface 1S. However, a force that scatters in the direction away from the scanning surface 1S is originally acting on the free substance 62, and the free substance 62 tends to fall obliquely downward by applying gravity to the free substance 62.

  A suction nozzle 52 is located immediately below the scanning position of the laser light on the scanning surface 1S. The suction nozzle 52 has the suction slit 52S facing obliquely upward with respect to the scanning surface 1S, and the free substance 62 is forcibly sucked by the suction air AW. Moreover, the traveling direction of the free substance 62 coincides with the suction direction of the suction air AW, and the free substance 62 is sucked into the suction nozzle 52 with high recovery efficiency by the action of both. Thereby, the free substance 62 does not disperse in a wide range, does not reattach to the organic EL mask 1, and a high degree of cleaning can be obtained.

  When the organic EL mask 1 is scanned with laser light, the vapor deposition material 61 is scattered as the free material 62, but the vapor deposition material 61 may remain in the organic EL mask 1. However, the decomposition force acts by the energy of the laser beam L, and the adhesion strength is greatly weakened. At this time, the suction nozzle 52 is provided immediately below the scanning portion of the laser light L, and the suction air AW having a large wind pressure acts on the vapor deposition material 61 from the suction nozzle 52, and therefore, if the adhesion strength is weakened, it is peeled off. In this way, it can be removed from the scanning surface 1S. Moreover, since the suction air AW acts on the scanning surface 1S from an oblique direction and the wind pressure is very small compared to the case of acting from the normal direction, the organic EL mask 1 is damaged by the wind pressure. Never given.

  Next, the air flow AF will be described. The air supply nozzle 53 sends out the air flow AF from the orthogonal direction toward the back surface 1R of the organic EL mask 1 (the surface opposite to the scanning surface 1S). The air supply nozzle 53 is set to a height that includes the scanning portion of the laser light in the organic EL mask 1 (that is, the height of the laser light in the Z direction and the height of the air supply nozzle 53 are set to be substantially the same. The air flow AF is sent out toward the organic EL mask 1. The air supply slit 53S has a larger opening area than the suction slit 52S, and sends out the airflow AF over a relatively wide range.

  The free substance 62 is scattered in the direction away from the scanning surface 1S, that is, in the direction opposite to the back surface 1R by the scanning of the laser light, and is sucked by the suction nozzle 52. However, the innumerably dispersed free substances 62 are powders, gases, and the like each having almost no mass, and therefore, a very small part of the free substances 62 may be directed to the organic EL mask 1. At this time, if the organic EL mask 1 is attached to the back surface 1R through the opening 3 of the organic EL mask 1, the free substance 62 attached to the back surface 1R is newly added when vapor deposition is performed using the same organic EL mask 1 next time. Transfers to a clean glass substrate and stains.

  Therefore, an air flow AF is formed from the air supply nozzle 53 and is blocked so that the free substance 62 does not enter the opening 3. Thereby, the free substance 62 does not adhere to the back surface 1R. The air flow AF is blocked so that the free substance 62 does not enter the opening 3. However, since the free substance 62 is extremely fine powder or gas, a large force is generated even by a slight air flow. Works. Thereby, the free substance 62 toward the opening 3 tries to move in the direction toward the suction nozzle 52. That is, the airflow AF is not only blocked so as not to wrap around the back surface 1R, but also assists to move toward the suction air AW.

  As described above, the air supply slit 53S has a wide opening area. Innumerable free substances 62 scattered by the scanning of the laser beam L tend to be dispersed over a wide range. Therefore, it is desirable to form the air flow AF over a wide range instead of forming the air flow AF locally. Therefore, the air supply slit 53S is formed wider than at least the suction slit 52S, and most preferably, the air flow AF is formed over the entire back surface 1R of the organic EL mask 1. By forming a weak air flow AF on the entire surface, the back surface 1R side is in a positive pressure state and can be blocked over the entire surface of the organic EL mask 1.

  When the free substance 62 is decomposed and scattered, it generates static electricity by friction and is charged positively or negatively. Which polarity is charged depends on the material of the free substance 62, that is, the material of the vapor deposition substance 61. A weak ion wind is used for the air flow AF, and the air flow AF itself has a positive or negative polarity. Therefore, the airflow AF is generated as an ion wind having a polarity opposite to the polarity charged by the material of the free substance 62. As described above, the air flow AF assists to move the free substance 62 toward the suction air AW, and the air flow AF is converted into an ion wind having characteristics opposite to those of the free substance 62. Therefore, the free substance 62 can be efficiently guided to the suction air AW. As a result, the free substance 62 can be recovered by the suction nozzle 52 with extremely high recovery efficiency.

  As described above, scanning of the uppermost line of the area A1 is performed while the air flow AF is sent out from the back surface 1R side and the free substance 62 is sucked by the suction air AW. After the scanning for one line is completed, the next one line of scanning in the Y direction is performed by lowering the reflection direction of the galvanometer mirror 34 by one line in the Z direction. At this time, following the line change, that is, following the scanning of the laser beam, the nozzle lifting / lowering unit 51 is also lowered by one line. Thereby, since the relative positional relationship between the irradiation position of the laser beam L in the Z direction and the suction nozzle 52 and the air supply nozzle 53 is constant, the free substance 62 can always be sucked with a constant high suction efficiency. become. For this reason, since the scanning position of the laser beam is determined by the reflection angle of the galvanometer mirror 34, it is possible to follow by connecting and synchronizing the driving device of the galvanometer mirror 34 and the lifting mechanism of the nozzle lifting unit 51. . For example, a control device such as a computer serves as a follow-up means for synchronizing and following the two.

  The laser cleaning of area A1 is thus completed. Next, laser cleaning of area A2 is performed. In this case, the Y-axis movement table 38 is moved in the Y direction so that the intermediate position of the area A2 and the reflection position on the galvanometer mirror 34 are matched in the Y direction. Since the area A2 is the same as the area A1 in the Z direction, the mask lifting unit 42 does not move up and down. However, since the nozzle raising / lowering unit 51 is located at the lowermost end of the area A1, it is raised so as to be located at the uppermost end. Then, while forming the suction air AW by the suction nozzle 52 and the air flow AF by the air supply nozzle 53, the laser light L is scanned for one line of the area A2, and after the scanning is finished, the nozzle lifting unit 51 is followed. One line is scanned. The above operation is performed to the lowest end, and the laser cleaning of the area A2 is completed.

  Next, laser cleaning of area A4 is performed. At this time, the mask raising / lowering unit 42 is raised so that the intermediate position of the area A4 and the reflection position on the galvanometer mirror 34 coincide with each other in the Z direction. Then, the nozzle lifting / lowering unit 51 is raised and positioned at the uppermost end of the area A4, and laser cleaning is sequentially performed one line at a time. After the laser cleaning of area A4 is completed, laser cleaning of area A3 is performed, and then laser cleaning of area A5 and area A6 is performed to complete laser cleaning of organic EL mask 1.

  In this way, by performing laser cleaning downward from the areas A1 and A2 located in the upper direction in the Z direction, any part of the organic EL mask 1 is not temporarily sucked by the suction nozzle 52. Even if it adheres again, the free substance 62 falls due to gravity, so it adheres again below the scanning portion of the laser beam. For this reason, even if it is reattached, there is no particular problem because the part is always laser-cleaned later.

  In the present invention, since the laser light L is scanned while forming the air flow AF from the back surface 1R of the organic EL mask 1 held in a vertical state, the free substance 62 adheres to the back surface 1R. Things will disappear. Since the innumerable scattered free substance 62 is sucked by the suction nozzle 52, the free substance 62 is not dispersed and does not reattach to the organic EL mask 1, and a high degree of cleaning can be obtained. Since the organic EL mask 1 is held in an upright state, the organic EL mask 1 does not bend during laser cleaning, so that there is no shift in the focal position, and a high and uniform cleaning degree can be obtained. Since the vapor deposition substance 61 is scattered as the free substance 62 by the scanning of the laser beam L and is collected by the suction nozzle 52, the non-contact laser cleaning can be performed completely, and the organic EL mask 1 is damaged. I don't give it.

  In the above, the organic EL mask 1 is transported in a horizontal posture with respect to the mask supply unit 10 and is rotated 90 degrees by the standing table 23. However, in the standing state, the organic EL mask cleaning is performed. You may make it carry in to an apparatus and pass to the mask raising / lowering unit 42 as it is. Thereby, there is no work of changing the posture from the horizontal state to the standing state, and there is an effect that the mechanism is simplified.

  Further, a dust collecting device may be connected to the suction nozzle 52. By using a filter, a cyclone or the like for the dust collector, only the free substance 62 can be recovered from those sucked by the suction air AW. The recovered free substance 62 is the vapor deposition substance 61, and the vapor deposition substance 61 can be reused by supplying it to the vapor deposition apparatus.

  Further, although the suction nozzle 52 and the air supply nozzle 53 have a length equal to or larger than the width of the organic EL mask 1, the lengths of the areas A1 to A6 may be provided. The effect described above can be obtained by providing the suction nozzle 52 and the air supply nozzle 53 with a length corresponding to the area where laser cleaning is performed. In this case, when the area for laser cleaning in the Y direction is changed, the suction nozzle 52 and the air supply nozzle 53 are moved in the Y direction.

  In the above example, the galvanometer mirror 34 is used to perform scanning in the Y direction and the Z direction. However, laser cleaning may be performed by operating the laser light source 33 at a high speed. That is, without galvanometer mirror 34, the laser light source 33 irradiates the organic EL mask 1 linearly toward the organic EL mask 1 and moves the laser light source 33 in the Y direction to perform scanning in the Y direction. Good.

DESCRIPTION OF SYMBOLS 1 Organic EL mask 2 Mask frame 3 Opening part 10 Mask supply part 11 Laser scanning part 12 Lifting mechanism 31 Laser optical system 32 Optical system moving part 33 Laser light source 34 Galvano mirror 42 Mask raising / lowering unit 51 Nozzle raising / lowering unit 52 Suction nozzle 53 Sending Air nozzle

Claims (9)

An organic EL mask cleaning device for removing a vapor deposition material attached to an organic EL mask,
Mask holding means for holding the organic EL mask in an upright state;
Laser cleaning means for scanning a laser beam from a horizontal direction with respect to a part or all of the region of the organic EL mask;
An air flow forming means for forming an air flow from the back surface side to the scanning surface side at the opening of the organic EL mask;
A suction means disposed below the scanning position of the laser beam, and an opening for obliquely upward opening for sucking free substances scattered from the organic EL mask by the cleaning of the laser cleaning means;
An organic EL mask cleaning device comprising: The organic EL mask cleaning apparatus according to claim 1, wherein the suction unit operates following a scanning portion of the laser beam. The organic EL mask cleaning apparatus according to claim 1, wherein the wind pressure sucked by the suction means is made larger than the wind pressure of the air flow of the air flow forming means. The organic EL mask cleaning apparatus according to claim 1, wherein the air flow forming unit forms the air flow with ion wind. The laser scanning means scans one line in the horizontal direction from the top of the region where the organic EL mask is cleaned, and sequentially scans the one line downward.
The length of the one line is provided in the air flow forming means and the suction means, and the air flow forming means and the suction means are sequentially lowered downward for each scanning of one line of the laser scanning means. The organic EL mask cleaning device according to 2. 2. The organic EL mask cleaning apparatus according to claim 1, wherein the mask holding means holds the organic EL mask in a state slightly inclined from a vertical direction.   An organic EL display manufacturing apparatus comprising the organic EL mask cleaning apparatus according to claim 1.   An organic EL display manufactured by the organic EL display manufacturing apparatus according to claim 7. An organic EL mask cleaning method for removing a vapor deposition material attached to an organic EL mask,
Hold the organic EL mask upright,
When scanning a laser beam from a horizontal direction for a part or all of the area of the organic EL mask, an air flow is formed from the back surface side to the scanning surface side in the opening of the organic EL mask,
An organic EL mask cleaning method, characterized in that a sucking means disposed below the laser beam scanning position sucks free substances scattered from the organic EL mask by the laser cleaning.

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