Ultraviolet irradiation device

Abstract

To provide an ultraviolet irradiation device capable of preventing the deformation of an irradiated object due to heat resulting from ultraviolet irradiation, and maintaining the precision of the irradiated object.SOLUTION: An ultraviolet irradiation device according to one embodiment of the present invention emits ultraviolet rays to an irradiated object, and comprises an ultraviolet light source, a stage and a heat absorption body. The ultraviolet light source emits ultraviolet rays. The stage supports the irradiated object. The heat absorption body is disposed between the irradiated object and the stage, and absorbs heat generated by ultraviolet rays emitted from the ultraviolet light source.SELECTED DRAWING: Figure 7A

Description

[Technical field]

[0001] The present invention relates to an ultraviolet irradiation device that irradiates an object with ultraviolet rays. [Background technology]

[0002] Organic EL (electroluminescence) elements are produced by depositing organic light-emitting material onto the pixel regions of a substrate. A deposition mask is used to deposit the organic light-emitting material onto only the pixel regions of the substrate.

[0003] Conventional deposition masks are metal masks with many tiny openings created by etching metal. Such metal masks are called fine metal masks (FMM) or high-definition metal masks. As organic EL panels have become larger, deposition masks have also become larger and heavier, reducing precision and making them difficult to handle. In addition, such deposition masks are made by combining components previously prepared by etching into a single deposition mask, which also reduces precision.

[0004] To produce higher-definition organic EL elements, it is necessary to make the thickness of the deposition mask thinner, and for this purpose, it has been proposed to use a resin thin film such as polyimide instead of metal. Deposition masks using a resin thin film have a structure in which a resin thin film with through holes is laminated on a metal layer in which metal frames are arranged in a lattice pattern (see, for example, Patent Documents 1, 2, and 3).

[0005] This type of deposition mask is called a thin film mask with a metal frame (or a fine hybrid mask (FHM), high-definition hybrid mask). A thin film mask with a metal frame is made by laminating a thin resin film and a metal frame, and then irradiating the thin resin film with laser light to form through holes. These through holes become the openings of the deposition mask, so they are highly accurate, and can be made thin and lightweight while maintaining their strength. This makes them suitable for larger organic EL panels. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2020-7623 A [Patent Document 2] JP 2013-83704 A [Patent Document 3] JP 2017-179591 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, when manufacturing a metal framed thin film mask, a large amount of debris (resin residue) is generated when forming through holes in the thin resin film by irradiating it with laser light. This debris is removed by chemical cleaning, but to prevent damage to the deposition mask, chemical cleaning must be performed for a long time. There is also a risk that the deposition mask may be broken due to the damage caused by the chemical cleaning.

[0008] Meanwhile, a method of removing the debris by irradiating ultraviolet light has also been considered. However, in this case, the amount of ultraviolet light required to remove the debris is enormous, and the temperature of the deposition mask and the stage on which the deposition mask is placed rises during ultraviolet light irradiation, causing deformation of the deposition mask and a decrease in accuracy.

[0009] In view of the above circumstances, an object of the present invention is to provide an ultraviolet irradiation device that can suppress deformation of an object to be irradiated due to heat generated by ultraviolet irradiation and maintain the precision of the object to be irradiated. [Means for solving the problem]

[0010] In order to achieve the above object, an ultraviolet irradiation device according to one aspect of the present invention is an ultraviolet irradiation device that irradiates an irradiation object with ultraviolet light, and includes an ultraviolet light source, a stage, and a heat absorber. The ultraviolet light source emits ultraviolet light. The stage supports the irradiation object. The heat absorber is disposed between the irradiation object and the stage, and absorbs heat generated by the ultraviolet rays emitted from the ultraviolet light source.

[0011] According to this configuration, the heat generated by the ultraviolet light emitted from the ultraviolet light source is absorbed by the heat absorber. This suppresses the temperature rise of the irradiation object, the heat absorber, and the stage, and also suppresses deformation due to thermal expansion. Therefore, it is possible to maintain the accuracy of the irradiation object.

[0012] The irradiation object has an opening, The heat absorber may absorb heat generated by ultraviolet light that is emitted from the ultraviolet light source and passes through the opening.

[0013] The ultraviolet irradiation device may further include a thermal expansion difference absorbing mechanism that maintains the position of the heat absorber relative to the stage and absorbs a thermal expansion difference between the stage and the heat absorber.

[0014] The thermal expansion difference absorption mechanism may be composed of a hole provided in the heat sink and a pin fixed to the stage and inserted into the hole, and a gap may be provided between the hole and the pin.

[0015] The heat absorber may include a heat absorbing member made of a thermally conductive material and a cooling mechanism for cooling the heat absorbing member.

[0016] The cooling mechanism may include a conduit in contact with the heat absorbing member and through which a coolant flows.

[0017] The heat absorbing member may be a plate-like member having a mounting surface on which the irradiation object is placed.

[0018] The ultraviolet irradiation device may further include a diffusion member disposed between the irradiation object and the heat absorber, for diffusing the ultraviolet light that has passed through the opening.

[0019] The diffusion member may be a plate-like member having a mounting surface on which the object to be irradiated is placed.

[0020] The heat absorber may include a heat absorbing member made of a thermally conductive material and a cooling mechanism for cooling the heat absorbing member, and the heat absorbing member may be a plate-like member having a mounting surface on which the diffusion member is placed.

[0021] The diffusing member may be frosted glass.

[0022] The diffusing member may be made of synthetic quartz glass.

[0023] The irradiation object may be a deposition mask.

[0024] The irradiation object includes a metal layer having a plurality of first through holes and a resin layer laminated on the metal layer and having a plurality of second through holes each of which communicates with the plurality of first through holes; The plurality of second through holes may form the opening.

[0025] The ultraviolet light source may be an excimer lamp.

[0026] The ultraviolet light source may be a low pressure mercury lamp. Effect of the Invention

[0027] According to the present invention, it is possible to provide an ultraviolet irradiation device capable of suppressing deformation of an object to be irradiated due to heat generated by ultraviolet irradiation and maintaining the precision of the object to be irradiated. [Brief description of the drawings]

[0028] [Figure 1] 1 is a plan view of a metal-framed thin film mask that is an object to be irradiated by an ultraviolet irradiation device according to an embodiment of the present invention. [Figure 2A] FIG. 2 is an enlarged cross-sectional view of the metal-framed thin film mask. [Figure 2B] FIG. 2 is an enlarged plan view of the metal-framed thin film mask. [Diagram 3]3 is a schematic diagram of a deposition method using the above-mentioned metal-framed thin film mask. FIG. [Figure 4A] 3A to 3C are schematic diagrams illustrating a method for manufacturing the metal-framed thin film mask. [Figure 4B] 3A to 3C are schematic diagrams illustrating a method for manufacturing the metal-framed thin film mask. [Figure 4C] 3A to 3C are schematic diagrams illustrating a method for manufacturing the metal-framed thin film mask. [Figure 4D] 3A to 3C are schematic diagrams illustrating a method for manufacturing the metal-framed thin film mask. [Figure 4E] 3A to 3C are schematic diagrams illustrating a method for manufacturing the metal-framed thin film mask. [Figure 4F] 3A to 3C are schematic diagrams illustrating a method for manufacturing the metal-framed thin film mask. [Diagram 5] FIG. 1 is a schematic diagram of a conventional ultraviolet irradiation device. [Figure 6] 1 is a schematic diagram of an ultraviolet irradiation device according to an embodiment of the present invention. [Figure 7A] FIG. 2 is a cross-sectional view of a partial configuration of the ultraviolet irradiation device. [Figure 7B] FIG. 2 is a plan view of a partial configuration of the ultraviolet irradiation device. [Figure 8A] FIG. 2 is a perspective view of a heat sink provided in the ultraviolet irradiation device. [Figure 8B] FIG. 2 is a perspective view of a heat sink provided in the ultraviolet irradiation device. [Figure 9A] 1 is a cross-sectional view of an ultraviolet irradiation device including a diffusion member according to an embodiment of the present invention. [Figure 9B] 1 is a plan view of an ultraviolet irradiation device including a diffusion member according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The ultraviolet irradiation device according to this embodiment is a device that irradiates an irradiation object with ultraviolet rays. An example of the irradiation object is a "metal-framed thin film mask." The metal-framed thin film mask is a deposition mask used in the manufacture of organic EL (electro-luminescence) panels and is also called a "fine hybrid mask (FHM)" or a "high-definition hybrid mask."

[0030] (Metal framed thin film mask configuration) The structure of the metal-framed thin film mask will be described. Fig. 1 is a plan view of the metal-framed thin film mask 100. Fig. 2 is an enlarged view of the metal-framed thin film mask 100, Fig. 2A is a cross-sectional view, and Fig. 2B is a plan view. As shown in Fig. 2A, the metal-framed thin film mask 100 comprises a metal layer 101, a resin layer 102, and an outer frame 103.

[0031] The metal layer 101 and the resin layer 102 form a plurality of mask regions 104 shown in Fig. 1. The mask regions 104 function as deposition masks, and for example, one mask region 104 is used to form one display. The shape and size of the mask regions 104 are not particularly limited.

[0032] 1, the outer frame 103 has a lattice shape and is provided around each mask region 104. The outer frame 103 is a member that maintains the strength of the metal-framed thin film mask 100, and is made of a metal such as Invar. The thickness (Z direction) of the outer frame 103 is, for example, 20 mm. The size of the metal-framed thin film mask 100 is the same as that of the substrate to be deposited.

[0033] 2B, the metal layer 101 has a lattice shape with a plurality of first through holes 101a and constitutes a metal frame. The metal layer 101 is made of a metal, for example, nickel (Ni). The metal layer 101 is fixed to the outer frame 103 by welding. The thickness (Z direction) of the metal layer 101 is, for example, 30 μm.

[0034] 2A, the resin layer 102 is laminated on the metal layer 101, and has a lattice shape in which a plurality of second through holes 102a are provided. The resin layer 102 is made of a resin, for example, polyimide (PI) or polyethylene terephthalate (PET). The thickness (Z direction) of the resin layer 102 is, for example, 10 μm.

[0035] Each of the first through holes 101a and each of the second through holes 102a communicate with each other to form one through hole 104a. The second through holes 102a are smaller than the first through holes 101a and are located on the inside of the first through holes 101a. The diameter of the second through holes 102a is, for example, 20 μm. Although several through holes 104a are shown in FIG. 2A and FIG. 2B, the number of through holes 104a in one mask region 104 is actually the number of pixels of one display, which is, for example, several millions.

[0036] (Deposition method using a thin film mask with a metal frame) A vapor deposition method using the metal-framed thin film mask 100 will be described. Fig. 3 is a schematic diagram of a vapor deposition apparatus 200 using the metal-framed thin film mask 100. As shown in the figure, the vapor deposition apparatus 200 includes a stage 201, a vapor deposition source 202, and a heat source 203.

[0037] The stage 201 supports a substrate T and a metal-framed thin film mask 100 on its vertically downward side. The substrate T is, for example, a glass substrate. The substrate T is sandwiched between the metal-framed thin film mask 100 and the stage 201. The stage 201 has a support mechanism such as a magnetic chuck, and supports the metal-framed thin film mask 100 and the substrate T by attracting the metal-framed thin film mask 100 by magnetic force.

[0038] The metal-framed thin-film mask 100 is supported with the resin layer 102 facing the deposition substrate T. Although not shown, a minute spacer is provided between the deposition substrate T and the metal-framed thin-film mask 100 to prevent them from coming into close contact with each other. The deposition source 202 contains a deposition material M, and is heated by a heat source 203 to evaporate the deposition material M. The deposition source 202 is, for example, a crucible. The deposition material M is, for example, an organic light-emitting material.

[0039] In this state, when the deposition material M is heated by the heat source 203, the vaporized deposition material rises toward the deposition substrate T (arrow in the figure). The deposition material M passes through the through-hole 104a to reach the deposition substrate T and is deposited on the surface of the deposition substrate T. As a result, a layer of the deposition material M is formed in an area of ​​the surface of the deposition substrate T facing the through-hole 104a. As described above, the second through-hole 102a is smaller than the first through-hole 101a and is located more inward than the first through-hole 101a. Therefore, the second through-hole 102a forms an opening in the metal-framed thin film mask 100.

[0040] (Metal framed thin film mask manufacturing method) A method for manufacturing the metal-framed thin film mask 100 will now be described.

[0041] First, a release agent H is applied to a support substrate G made of glass or the like. A varnish made of polyimide or the like is applied on top of that to form a thin resin film. A metal coating made of a metal such as nickel is then formed on top of that. The metal coating can be formed by forming a seed layer on the resin film by electroless plating, and then growing the metal layer on the seed layer to the desired thickness by electrolytic plating.

[0042] Next, a photoresist is applied onto the metal film, and the photoresist is irradiated with ultraviolet light using a mask pattern. The photoresist is then developed to form a resist pattern. Development can be performed by removing the unreacted parts of the photoresist with a developer such as an alkaline solution.

[0043] Next, the substrate is immersed in an etching bath, and the exposed parts of the metal film, i.e., the parts not covered by the resist pattern, are removed by etching. Next, the photoresist is stripped off using a resist stripper. This allows the metal film to be formed into a lattice shape, as shown in FIG. 4A. Next, the resin film is stripped off from the support substrate. In this way, a metal layer 101 having a lattice shape can be produced, as shown in FIG. 4B.

[0044] Next, as shown in Fig. 4C, laser light L is irradiated onto resin layer 112 through first through hole 101a of metal layer 101. As a result, second through hole 102a is formed in resin layer 112, and resin layer 102 is formed, as shown in Fig. 4D.

[0045] At this time, as shown in Fig. 4D, debris S adheres to the surface of the metal layer 101. The debris S is a residue of the resin that constitutes the resin layer 102 and that was not decomposed and evaporated when the second through-hole 102a was formed by the laser light L. If this debris S is left as it is, it may scatter and adhere to the resin layer 102, blocking a part of the second through-hole 102a, or fall and become mixed into the deposition material M of the deposition source 202. For this reason, ultraviolet rays U are irradiated onto the metal layer 101 as shown in Fig. 4E, and the debris S is removed as shown in Fig. 4F.

[0046] The metal-framed thin film mask 100 is manufactured as described above. In the above-mentioned ultraviolet ray U irradiation step (see FIG. 4E), a large amount of strong debris S needs to be removed, and heat generated by ultraviolet ray irradiation becomes a problem. As will be described later, the ultraviolet ray irradiation device according to this embodiment takes measures against the heat generated by ultraviolet ray irradiation.

[0047] The manufacturing method of the metal-framed thin film mask 100 is not limited to the above. For example, a step of removing the debris S by ultrasonic cleaning may be performed before or after the step of irradiating the ultraviolet ray U. By performing both the ultraviolet ray irradiation and the ultrasonic cleaning, the time required to remove the debris S can be shortened.

[0048] (Configuration of a conventional ultraviolet irradiation device) A conventional ultraviolet irradiation device used in the above-mentioned ultraviolet irradiation step (see FIG. 4E) will be described. FIG. 5 is a schematic diagram of a conventional ultraviolet irradiation device 500. As shown in the figure, the ultraviolet irradiation device 500 includes a housing 501, an ultraviolet irradiator 502, a driving mechanism 503, a support 504, and a stage 505. An irradiation object W is placed on the stage 505. The irradiation object W is, for example, a thin film mask 100 with a metal frame (see FIG. 4E) having debris S attached thereto, and is placed so that the metal layer 101 (see FIG. 2A) faces upward.

[0049] The housing 501 forms an ultraviolet irradiation space therein. The ultraviolet irradiation space is at atmospheric pressure. The ultraviolet irradiator 502 is disposed on the upper part of the housing 501, and includes an ultraviolet light source 510. An excimer lamp (peak wavelength 172 nm) or a low pressure mercury lamp (peak wavelengths 185 nm and 254 nm) can be used as the ultraviolet light source 510. The bottom of the ultraviolet irradiator 502 is open, and the ultraviolet light emitted from the ultraviolet light source 510 is irradiated downward.

[0050] Driving mechanism 503 is disposed at the bottom of housing 501, and moves support 504 and stage 505. Specifically, driving mechanism 503 is a linear cylinder device, and includes cylinder section 503a, driving source 503b, and base section 503c. By driving source 503b rotating the ball screw inside cylinder section 503a, base section 503c can be moved in the horizontal direction (arrow in the figure) at a predetermined speed.

[0051] Support 504 is provided on pedestal 503c and supports stage 505. Stage 505 has mounting surface 505a and supports irradiation object W placed on mounting surface 505a. Stage 505 is reinforced with a rib structure or the like as necessary. When driving mechanism 503 is driven, stage 505 moves in the horizontal direction as shown by the arrow in the figure, so that ultraviolet rays emitted from ultraviolet irradiator 502 are uniformly irradiated from one end to the other end of irradiation object W.

[0052] The ultraviolet irradiation device 500 has the above-mentioned configuration. Here, in general optical cleaning by ultraviolet irradiation, the ultraviolet irradiation time is several seconds, and no problems due to heat occur. Even for larger irradiation objects W, the flatness of the mounting surface 505a can be ensured by reinforcing the stage 505, etc. However, in the process of removing the debris S from the metal-framed thin film mask 100 (see FIG. 4E), the debris S becomes large and strong, so an ultraviolet irradiation time of several minutes to several hours is required.

[0053] Therefore, when the ultraviolet irradiation device 500 is used in this process, the stage 505 accumulates heat due to ultraviolet irradiation, causing thermal expansion, and the stage 505 is curved or deformed. The stage 505 is curved in such a way that it becomes convex toward the hot side (ultraviolet irradiation side) due to the heat distribution of the members constituting the stage 505. On such a stage 505, the irradiation object W is curved following the stage 505 and is subjected to stress. For this reason, when the irradiation object W is a thin film mask 100 with a metal frame, the resin layer 102 stretches and the weld between the metal layer 101 and the outer frame 103 breaks.

[0054] The cause of deformation of the stage 505 is complex. When the irradiation object W is a metal-framed thin film mask 100, a large amount of debris S is initially attached to the metal-framed thin film mask 100, so that the stage 505 is shielded from ultraviolet rays by the metal-framed thin film mask 100. As the debris S is gradually removed, ultraviolet rays begin to pass through the through-holes 104a (see FIG. 2B) of the metal-framed thin film mask 100, and ultraviolet ray irradiated regions and non-irradiated regions are formed on the stage 505. A difference occurs in the temperature rise rate, i.e., the expansion rate, between the irradiated region and the non-irradiated region, so that deformation such as undulation occurs in the stage 505.

[0055] (Configuration of the ultraviolet irradiation device according to this embodiment) The ultraviolet irradiation device according to this embodiment will be described. Fig. 6 is a schematic diagram of an ultraviolet irradiation device 300 according to this embodiment. As shown in the figure, the ultraviolet irradiation device 300 includes a housing 301, an ultraviolet irradiator 302, a driving mechanism 303, a support 304, a stage 305, and a heat absorber 306. An irradiation object W is placed on the stage 305. The irradiation object W is, for example, a thin film mask 100 with a metal frame (see Fig. 4E) having debris S attached thereto, and is placed so that the metal layer 101 (see Fig. 2A) faces upward.

[0056] The housing 301 forms an ultraviolet irradiation space therein. The ultraviolet irradiation space is at atmospheric pressure. The ultraviolet irradiator 302 is disposed on the upper part of the housing 301, and includes an ultraviolet light source 310. An excimer lamp (peak wavelength 172 nm) or a low-pressure mercury lamp (peak wavelengths 185 nm and 254 nm) can be used as the ultraviolet light source 310. The bottom of the ultraviolet irradiator 302 is open, and the ultraviolet light emitted from the ultraviolet light source 310 is irradiated downward.

[0057] Driving mechanism 303 is disposed at the bottom of housing 301, and moves support 304 and stage 305. Specifically, driving mechanism 303 is a linear cylinder device, and includes cylinder section 303a, driving source 303b, and base section 303c. Driving source 303b rotates a ball screw inside cylinder section 303a, thereby moving base section 303c in the horizontal direction (arrow in the figure) at a predetermined speed. Note that driving mechanism 303 may have any other configuration as long as it is capable of moving stage 305.

[0058] Support 304 is provided on pedestal 303c and supports stage 305. Stage 305 has mounting surface 305a and supports irradiation object W. Stage 305 is reinforced with a rib structure or the like as necessary. When driving mechanism 303 is driven, stage 305 moves in the horizontal direction as shown by the arrow in the figure, so that ultraviolet rays emitted from ultraviolet irradiator 302 are uniformly irradiated from one end to the other end of irradiation object W.

[0059] The heat absorber 306 is disposed between the irradiation object W and the stage 305, and absorbs heat generated by ultraviolet rays emitted from the ultraviolet light source 310. FIG. 7 is a schematic diagram of a part of the configuration of the ultraviolet irradiation device 300, with FIG. 7A being a cross-sectional view and FIG. 7B being a plan view. As shown in these figures, the heat absorber 306 is placed on a mounting surface 305a of the stage 305, but is not fixed to the stage 305, and its position is held by a thermal expansion difference absorbing mechanism 307. The heat absorber 306 has a mounting surface 306a on the opposite side to the stage 305, and the irradiation object W is placed on the mounting surface 306a. The irradiation object W is also not fixed to the heat absorber 306, but is simply placed thereon.

[0060] As shown in Fig. 7B, the irradiation object W has an opening N. The opening N is, for example, the mask region 104 (see Fig. 1) of the metal-framed thin film mask 100, and more specifically, each through-hole 104a (see Fig. 2B). The ultraviolet light irradiated to the irradiation object W passes through the opening N and enters the heat absorber 306, and the heat generated by the ultraviolet light is absorbed by the heat absorber 306.

[0061] Fig. 8 is a perspective view of heat absorber 306, Fig. 8A is a view seen from the mounting surface 306a side, and Fig. 8B is a view seen from the opposite side to Fig. 8A. As shown in these figures, heat absorber 306 includes heat absorbing member 308 and cooling mechanism 309.

[0062] The heat absorbing member 308 is a plate-like member made of a thermally conductive material such as aluminum, and as shown in Fig. 8A, the surface of the heat absorbing member 308 opposite to the stage 305 constitutes the mounting surface 306a. As shown in Fig. 7B, the heat absorbing member 308 has a size that allows the entire irradiation target W to be placed thereon.

[0063] Cooling mechanism 309 cools heat absorbing member 308. Cooling mechanism 309 includes conduit 311 in contact with heat absorbing member 308 as shown in Fig. 8B. Conduit 311 is connected to a refrigerant supply source (not shown), and cools heat absorbing member 308 by the flow of refrigerant. Conduit 311 is provided on the opposite side of heat absorbing member 308 from mounting surface 306a, and also contacts stage 305. Conduit 311 has a shape of a pipe with an outer diameter of 8 mm, an inner diameter of 6 mm, and a length of 4 m, bent three times, for example, and four systems are arranged.

[0064] 8B, the conduit 311 may have a groove formed in the heat absorbing member 308 and may be covered with a flat plate or the like. Alternatively, the cooling mechanism 309 may be any mechanism capable of cooling the heat absorbing member 308, such as a Peltier element or a heat sink.

[0065] The thermal expansion difference absorbing mechanism 307 holds the position of the heat absorber 306 relative to the stage 305 and absorbs the thermal expansion difference between the stage 305 and the heat absorber 306. Specifically, as shown in Figs. 7A and 7B, the thermal expansion difference absorbing mechanism 307 is composed of a hole 307a provided in the heat absorber 306 and a pin 307b fixed to the stage 305, and the pin 307b is inserted into the hole 307a. The inner diameter of the hole 307a is larger than the outer diameter of the pin 307b, and a gap is provided between the hole 307a and the pin 307b. As a result, even if a thermal expansion difference occurs between the stage 305 and the heat absorber 306, the pin 307b moves within the hole 307a and absorbs the thermal expansion difference, so that deformation of the stage 305 and the heat absorber 306 can be suppressed.

[0066] In this way, the position of the heat absorber 306 relative to the stage 305 is maintained by the thermal expansion difference absorbing mechanism 307, and the heat absorber 306 is prevented from shifting in position relative to the stage 305 and from falling off. For example, four thermal expansion difference absorbing mechanisms 307 are provided around the irradiation target W as shown in FIG. 7B, but two or more may be provided. The configuration of the thermal expansion difference absorbing mechanism 307 is not limited to that shown here, and it is sufficient that the mechanism maintains the position of the heat absorber 306 relative to the stage 305 and absorbs the thermal expansion difference between the stage 305 and the heat absorber 306.

[0067] The ultraviolet irradiation device 300 has the above-mentioned configuration. Note that the configuration of the ultraviolet irradiation device 300 is not limited to that shown here, and it is sufficient that the ultraviolet irradiation device 300 includes at least the ultraviolet light source 310, the stage 305, and the heat absorber 306. For example, it is also possible to adopt a configuration in which the ultraviolet light source 310 moves instead of the stage 305, or a configuration in which neither the stage 305 nor the ultraviolet light source 310 moves.

[0068] (Operation and Effects of the Ultraviolet Irradiation Device According to the Present Embodiment) In the ultraviolet irradiation device 300, as described above, the heat absorber 306 is placed on the stage 305, and the irradiation object W is placed on the heat absorber 306. The heat absorber 306 is held relative to the stage 305 by the thermal expansion difference absorbing mechanism 307, and the irradiation object W is not fixed relative to the heat absorber 306. In this state, the stage 305 moves as shown in Fig. 6, and ultraviolet rays are irradiated from the ultraviolet irradiator 302 onto the entire irradiation object W. The stage 305 may reciprocate multiple times during ultraviolet irradiation.

[0069] Here, if the irradiation object W is a metal-framed thin film mask 100 (see FIG. 4E) with debris S attached thereto, long-term ultraviolet irradiation is required to remove the debris S. This ultraviolet light passes through the openings of the metal-framed thin film mask 100 and enters the heat absorber 306, generating heat, which is absorbed by the heat absorber 306. This suppresses temperature rises in the irradiation object W, the heat absorber 306, and the stage 305, and also suppresses deformation due to thermal expansion.

[0070] Even if thermal expansion occurs in the heat absorber 306 and the stage 305, the thermal expansion difference between them is absorbed by the thermal expansion difference absorbing mechanism 307, and no stress is generated, so that the flatness of the mounting surface 306a is maintained and deformation of the irradiation object W is prevented. Therefore, by using the ultraviolet irradiation device 300, the precision of the irradiation object W is maintained.

[0071] When the irradiation object W is a metal-framed thin film mask 100 with debris S attached thereto, the process of removing the debris S (see FIG. 4E) does not result in a decrease in accuracy of the metal-framed thin film mask 100, making it possible to manufacture a high-accuracy metal-framed thin film mask 100. Since debris removal by ultraviolet irradiation is completed in a shorter time than debris removal by chemical cleaning, it is possible to manufacture a high-accuracy metal-framed thin film mask 100 in a shorter time.

[0072] Damage to the metal-framed thin film mask 100 can be evaluated by the amount of deviation of the mark before and after ultraviolet irradiation, using the position marks in the metal-framed thin film mask 100. When the conventional ultraviolet irradiation device 500 was used, the amount of deviation of the mark was 5 μm or more, but it has been confirmed that when the ultraviolet irradiation device 300 according to this embodiment is used, the amount of deviation of the mark is less than 1.5 μm.

[0073] The irradiation object W is not limited to the metal-framed thin film mask 100, and any object that may be deformed by heat due to ultraviolet irradiation and may have a reduced accuracy may be suitable as the irradiation object W.

[0074] (About the diffusion plate) The ultraviolet irradiation device 300 according to this embodiment may include a diffusion member. Fig. 9 is a cross-sectional view of a portion of the ultraviolet irradiation device 300 including a diffusion member 312, Fig. 9A being a cross-sectional view and Fig. 9B being a plan view. Note that Fig. 9B shows a perspective view of the irradiation object W. As shown in Fig. 9A, the diffusion member 312 is disposed between the irradiation object W and the heat absorber 306.

[0075] Specifically, the diffusion member 312 is a plate-like member, and is placed on the placement surface 306a of the heat absorber 306. The diffusion member 312 is not fixed to the heat absorber 306, but is simply placed thereon. The diffusion member 312 has a placement surface 312a on the side opposite the heat absorber 306, and the irradiation object W is placed on this placement surface 312a. The irradiation object W is also not fixed to the diffusion member 312, but is simply placed thereon.

[0076] The diffusing member 312 diffuses and transmits the incident ultraviolet light. Specifically, the diffusing member 312 is made of ground glass, and at least one surface of the diffusing member 312 is ground. The material of the diffusing member 312 is preferably one that has a high transmittance for the ultraviolet light of the wavelength emitted by the ultraviolet irradiator 302, and can be synthetic quartz glass. The diffusing member 312 can also be made of any material that can diffuse ultraviolet light. As shown in FIG. 9B, the diffusing member 312 is large enough to accommodate the entire irradiation target W.

[0077] When ultraviolet light is irradiated from the ultraviolet irradiator 302, the ultraviolet light passes through the opening N of the irradiation target W, enters the diffusion member 312, and is transmitted through the diffusion member 312. At this time, the diffusion member 312 diffuses the ultraviolet light. The ultraviolet light that has transmitted through the diffusion member 312 enters the heat absorber 306, and the heat is absorbed by the heat absorber 306.

[0078] In this way, the ultraviolet light is diffused by the diffusing member 312, thereby making it possible to reduce the temperature difference on the stage 305. In the irradiation target W, there are some parts through which the ultraviolet light passes and some parts that do not pass through, depending on the shape of the opening N. By diffusing the ultraviolet light that has passed through the opening N by the diffusing member 312, the difference in the ultraviolet light intensity between the two parts is weakened, and the temperature rise of the stage 305 is made uniform, i.e., the unevenness in the thermal expansion coefficient can be reduced.

[0079] Furthermore, by using a material with high UV transmittance such as synthetic quartz glass for the diffusion member 312, most of the UV rays that have passed through the openings N can be guided to the placement surface 306a (see FIG. 9A). This makes it possible to suppress temperature rises in the irradiation object W and the diffusion member 312, and further suppress deformation of the irradiation object W.

[0080] In addition, when the heat absorber 306 is not required, such as when the ultraviolet irradiation time is short, it is also possible to place only the diffusion member 312 on the stage 305 and place the irradiation target W on top of it. In this case, although the heat absorber 306 does not absorb heat, the diffusion member 312 can make the temperature rise uniform.

[0081] In the present disclosure, when the term "approximately" is used, this is used only to facilitate understanding of the description, and there is no special meaning in using or not using the term "approximately". That is, in the present disclosure, concepts that define the shape, size, positional relationship, state, etc., such as "center", "middle", "uniform", "equal", "same", "orthogonal", "parallel", "symmetric", "extend", "axial direction", "circular", "arc-shaped", "rectangular", "rectangular", "polygonal", "ring-shaped", "cubic", "cuboid", "cylindrical", "disk-shaped", "cone-shaped", etc., include concepts such as "substantially center", "substantially center", "substantially uniform", "substantially equal", "substantially the same", "substantially orthogonal", "substantially parallel", "substantially symmetric", "substantially extend", "substantially axial direction", "substantially circular", "substantially arc-shaped", "substantially rectangular", "substantially rectangular", "substantially polygonal", "substantially ring-shaped", "substantially cube-shaped", "substantially cuboid", "substantially cylindrical", "substantially disk-shaped", "substantially cone-shaped", etc. For example, it also includes a state that is included within a predetermined range (e.g., a range of ±10%) based on the criteria of "perfectly centered," "perfectly central," "perfectly uniform," "perfectly equal," "perfectly the same," "perfectly orthogonal," "perfectly parallel," "perfectly symmetrical," "perfectly extended," "perfectly axial," "perfectly circular," "perfectly arc-shaped," "perfectly rectangular," "perfectly oblong," "perfectly polygonal," "perfectly ring-shaped," "perfectly cubic," "perfectly rectangular," "perfectly cylindrical," "perfectly disk-shaped," "perfectly cone-shaped," etc. Therefore, even if the word "approximately" is not added, the concept expressed by adding "approximately" may be included. Conversely, a perfect state is not excluded when the word "approximately" is added.

[0082] In the present disclosure, expressions using "more than", such as "greater than A" and "smaller than A", are expressions that comprehensively include both concepts that include equivalent to A and concepts that do not include equivalent to A. For example, "greater than A" is not limited to cases that do not include equivalent to A, but also includes "A or greater". Furthermore, "smaller than A" is not limited to "less than A", but also includes "A or less". When implementing the present technology, specific settings, etc. may be appropriately adopted from the concepts included in "greater than A" and "smaller than A" so that the effects described above are achieved.

[0083] It is also possible to combine at least two of the characteristic parts of the present technology described above. That is, the various characteristic parts described in each embodiment may be arbitrarily combined without distinction between the embodiments. In addition, the various effects described above are merely examples and are not limited thereto, and other effects may be exhibited. [Explanation of symbols]

[0084] 100...Metal framed thin film mask 101...Metal layer 102...Resin layer 103…Outer frame 300...UV irradiation device 301…Housing 302...UV irradiator 303...Drive mechanism 304…post 305…Stage 306...Heat absorber 307…Thermal expansion difference absorption mechanism 310...UV light source 312... Diffusion material

Claims

1. An ultraviolet irradiation device that irradiates an irradiation object with ultraviolet rays, An ultraviolet light source that emits ultraviolet light; A stage for supporting the irradiation object; a heat absorber disposed between the irradiation object and the stage, the heat absorber absorbing heat generated by the ultraviolet light emitted from the ultraviolet light source; An ultraviolet irradiation device comprising:

2. The ultraviolet irradiation device according to claim 1, The irradiation object has an opening, The heat absorber absorbs heat generated by ultraviolet light emitted from the ultraviolet light source and passing through the opening. Ultraviolet irradiation device.

3. The ultraviolet irradiation device according to claim 1, a thermal expansion difference absorbing mechanism that holds the position of the heat absorber relative to the stage and absorbs the thermal expansion difference between the stage and the heat absorber; The ultraviolet irradiation device further comprises:

4. The ultraviolet irradiation device according to claim 3, The thermal expansion difference absorbing mechanism is composed of a hole provided in the heat sink and a pin fixed to the stage and inserted into the hole, with a gap provided between the hole and the pin. Ultraviolet irradiation device.

5. The ultraviolet irradiation device according to claim 1, The heat absorber includes a heat absorbing member made of a thermally conductive material and a cooling mechanism for cooling the heat absorbing member. Ultraviolet irradiation device.

6. The ultraviolet irradiation device according to claim 5, The cooling mechanism includes a conduit in contact with the heat absorbing member and through which a refrigerant flows. Ultraviolet irradiation device.

7. The ultraviolet irradiation device according to claim 6, The heat absorbing member is a plate-like member having a mounting surface on which the irradiation object is placed. Ultraviolet irradiation device.

8. The ultraviolet irradiation device according to claim 2, a diffusion member disposed between the irradiation object and the heat absorber, the diffusion member diffusing the ultraviolet light that has passed through the opening; The ultraviolet irradiation device further comprises:

9. The ultraviolet irradiation device according to claim 8, The diffusion member is a plate-like member having a mounting surface on which the irradiation object is placed. Ultraviolet irradiation device.

10. The ultraviolet irradiation device according to claim 9, The heat absorber includes a heat absorbing member made of a thermally conductive material and a cooling mechanism for cooling the heat absorbing member, and the heat absorbing member is a plate-like member having a mounting surface on which the diffusion member is mounted. Ultraviolet irradiation device.

11. The ultraviolet irradiation device according to claim 8, The diffusing member is frosted glass. Ultraviolet irradiation device.

12. The ultraviolet irradiation device according to claim 11, The diffusing member is made of synthetic quartz glass. Ultraviolet irradiation device.

13. The ultraviolet irradiation device according to claim 2, The irradiation object is a deposition mask. Ultraviolet irradiation device.

14. The ultraviolet irradiation device according to claim 13, The irradiation object includes a metal layer having a plurality of first through holes and a resin layer laminated on the metal layer and having a plurality of second through holes each of which communicates with the plurality of first through holes; The plurality of second through holes form the opening. Ultraviolet irradiation device.

15. The ultraviolet irradiation device according to claim 1, The ultraviolet light source is an excimer lamp. Ultraviolet irradiation device.

16. The ultraviolet irradiation device according to claim 1, The ultraviolet light source is a low pressure mercury lamp. Ultraviolet irradiation device.

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