Frame body and vapor deposition mask

Abstract

To provide a frame body and vapor deposition mask, capable of improving accuracy related to vapor deposition.SOLUTION: A frame body 1 can be arranged in the state that: first and second frame members forming a frame body 3 having a lamination structure are formed so as to more increase the opening area of the first frame member to that of the second frame member and the opening area of the frame body 3 expands in a part distant from a mask body 2 to retreat a peripheral part surrounding the opening area. Thereby, a deposition process can prevent the peripheral part around the opening area in the frame body 3 from forming an obstacle for blocking the advance of a vapor deposition material toward a substrate to be deposited through the opening area of the frame body 3 and the vapor deposition through-holes of the mask body 2 and can exclude the influence of the frame body 3 to each vapor deposition through-hole to perfectly advance the vapor deposition material and more appropriately perform vapor deposition.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a frame used to reinforce a mask body, and a deposition mask including the frame. [Background technology]

[0002] The deposition mask method is often used to form the light-emitting layer of an organic EL (Electroluminescence) element. In this deposition mask method, a deposition mask with holes removed at the locations of the substrate corresponding to the deposition sites is used to deposit organic light-emitting materials at desired locations on a substrate made of a transparent material such as glass.

[0003] In a deposition apparatus for performing deposition, a deposition mask is set in a state where it is correctly aligned with a substrate to be deposited, and deposition is performed. However, since heating is generally performed during deposition to create an environment in the deposition apparatus suitable for deposition, if the deposition mask and the glass substrate are in different thermal deformation states, the relative positional relationship between the deposition mask and the substrate changes, and there is a problem that the required precision of the formed light-emitting layer cannot be satisfied.

[0004] In recent years, a deposition mask has been proposed that employs a mask structure in which a reinforcing frame made of a material having the same thermal expansion coefficient as the substrate to be deposited (e.g., glass) or a material with a low thermal expansion coefficient is attached to the outer edge of a thin mask body. This allows the mask body to change shape in response to the expansion of the frame having the same thermal expansion coefficient as the substrate to be deposited, or to remain unaffected by the frame having a low thermal expansion coefficient, even when a mask body made of a material having a different thermal expansion coefficient from the substrate to be deposited is used. This ensures accurate alignment of the mask body with the substrate to be deposited when the temperature is increased in the deposition apparatus, and enables the formation of a light-emitting layer on the substrate to be deposited with high precision. An example of such a conventional deposition mask is disclosed in Japanese Patent Application Laid-Open No. 2005-15908. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2005-15908 A Summary of the Invention [Problem to be solved by the invention]

[0006] Conventional deposition masks have the structure shown in Patent Document 1, which can suppress relative deformation between the mask and the substrate due to differences in thermal expansion coefficients and prevent significant deterioration in the positional accuracy of the deposition product. However, there is a demand in the market for even higher precision in deposition formation, and there is a need to further suppress the occurrence of deviations due to mask displacement.

[0007] In the conventional combination structure of the mask body and the frame, it is easy to think of thickening the frame to ensure the strength of the frame to withstand the displacement of the mask body, but if the frame near the mask body becomes too thick, it has a negative effect, such as partially preventing the deposition material such as an organic light-emitting substance from progressing to the through holes of the mask body during deposition, so it is not possible to simply increase the thickness. In addition, when the frame becomes thick to a certain extent, the weight of the frame also increases, causing problems such as deformation due to bending due to the weight of the frame itself, which in turn affects the mask body and leads to a deterioration in positional accuracy. For this reason, the method of increasing the thickness of the frame to improve its strength and improve the accuracy of the mask has a limit value for applicable thickness, and it is not realistic to improve the strength beyond that limit.

[0008] In addition, when the frame is formed from a metal plate material that is generally available and easily available, the plate material is manufactured through processing such as rolling, so that the plate material has a certain amount of distortion due to processing remaining inside. The effect of the internal distortion of the plate material generated during such manufacturing process becomes more noticeable as the plate thickness increases. Therefore, if the plate thickness of the frame is increased, that is, the thickness of the plate material used for the frame is increased, when the frame is finally obtained by further processing such as cutting from the plate material, the distortion appears as a slight warp of the frame, etc., and the frame's original shape cannot be strictly realized, which adversely affects the accuracy of the mask. From these points of view, it can be said that it is difficult to improve the strength of the frame by simply making it thicker. It is possible to use a distortion-free metal plate material manufactured by special processing or a plate material that has been subjected to an internal stress relief treatment in advance as the metal plate material for the frame body to prevent the frame body from being affected by distortion. However, since distortion-free plate material and stress relief treatment are expensive, it was not possible to obtain the frame body economically.

[0009] Furthermore, if the mask body is made only of matte nickel, the tension generated in the completed mask body will be excessively large, which may lead to deformation of the frame.

[0010] As described above, with conventional mask structures, it was difficult to maintain the displacement of the mask body within the increasingly strict tolerance range associated with increased precision in terms of the strength of the frame, and there was a problem that a decrease in yield due to misalignment of the deposited product was unavoidable.

[0011] An object of the present invention is to provide a frame and a deposition mask that can improve the accuracy of deposition. [Means for solving the problem]

[0012] The frame body disclosed in the present invention is formed from a material with a low thermal expansion coefficient and is used to reinforce the mask body. The frame body has a laminated structure in which at least a first frame member and a second frame member are stacked and integrated together, and has an overall shape having a rectangular outer frame portion located at the outermost periphery and an inner frame portion that divides the inside of the outer frame portion into a plurality of opening areas. The width of each portion of the second frame member is formed larger than that of the first frame member so that the opening areas of the first frame member are larger than the opening areas of the second frame member.

[0013] According to the disclosure of the present invention, the first frame member and the second frame member forming the laminated frame are formed so that the opening area of ​​the first frame member is larger than the opening area of ​​the second frame member, and the frame can be disposed in a state in which the opening area of ​​the frame expands at a portion far from the mask body and the peripheral portion surrounding the opening area is recessed. As a result, in the deposition process, the peripheral portion around the opening area of ​​the frame is less likely to become an obstacle that impedes the progress of the deposition material toward the deposition target substrate through the opening area of ​​the frame and the deposition through holes of the mask body, and the deposition material can proceed without problems by eliminating the influence of the frame on each deposition through hole, and deposition can be performed more appropriately. [Brief description of the drawings]

[0014] [Figure 1] 1 is a schematic plan view of a deposition mask according to an embodiment of the present invention. [Diagram 2] 1 is a diagram illustrating a configuration of a main part of a deposition mask according to an embodiment of the present invention; [Diagram 3] 1 is a schematic cross-sectional view of a main part of a deposition mask according to one embodiment of the present invention. [Figure 4] FIG. 2 is a plan view of a frame in the deposition mask according to one embodiment of the present invention. [Diagram 5] 5A to 5C are explanatory views of a process for forming a frame in the deposition mask according to the embodiment of the present invention. [Figure 6] 1A to 1C are diagrams illustrating a process of forming a primary pattern resist in the manufacture of a deposition mask according to an embodiment of the present invention. [Figure 7]4A to 4C are diagrams illustrating a primary electrodeposition layer forming step in the manufacture of a deposition mask according to one embodiment of the present invention. [Figure 8] 1A to 1C are diagrams illustrating the first half of a secondary pattern resist formation process in manufacturing a deposition mask according to an embodiment of the present invention. [Figure 9] 1A to 1C are explanatory views of the second half of a secondary pattern resist formation process in the manufacture of a deposition mask according to an embodiment of the present invention. [Figure 10] 10A to 10C are explanatory views of a frame compression bonding step in the manufacture of a deposition mask according to one embodiment of the present invention. [Figure 11] 5A to 5C are diagrams illustrating a metal layer forming step and a separation state of the deposition mask and the matrix in the manufacture of the deposition mask according to the embodiment of the present invention. [Figure 12] FIG. 4 is a schematic plan view of another example of a deposition mask according to an embodiment of the present invention. [Figure 13] 11A and 11B are a plan view and a schematic cross-sectional view of another frame in the deposition mask according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, a deposition mask according to one embodiment of the present invention will be described with reference to Fig. 1 to Fig. 11. In this embodiment, an example in which the deposition mask is applied to an organic EL element will be described. In each of the drawings, the deposition mask 1 according to this embodiment includes a plurality of mask bodies 2 each having a large number of deposition through-holes 8 formed in a predetermined pattern, and a frame body 3 disposed around the mask body 2.

[0016] The mask body 2 is made of nickel, nickel alloys such as nickel cobalt, or other electrodeposited metals, and is formed into a sheet shape by electroforming, and is configured to have a large number of independent deposition through holes 8 formed in a predetermined pattern to allow the deposition material to pass through.

[0017] The mask body 2 includes an internal pattern formation region 2a in which a large number of deposition through-holes 8 are provided, and an outer peripheral edge 2b which is integrally joined to the frame body 3 via a metal layer 7 formed by plating. In the pattern formation region 2a, the large number of deposition through-holes 8 for forming a light-emitting layer form a matrix-like deposition pattern 9 in which a plurality of through-hole groups arranged linearly in the front-rear direction are arranged in rows, and a plurality of rows are arranged in parallel in the left-right direction. The thickness of the mask body 2 is preferably in the range of 5 to 20 μm, and is set to 8 μm in this embodiment.

[0018] The frame body 3 is a rectangular frame-shaped plate thicker than the mask body 2, and is arranged to surround the outside of the mask body 2 to reinforce the mask body 2, and is integrally connected to the mask body 2. In detail, the frame body 3 has a rectangular outer frame portion 4 located at the outermost periphery, and an inner frame portion 5 that divides the inside of the outer frame portion 4 into a plurality of opening regions 6, and is formed in a lattice shape as a whole. The mask body 2 is located in each of the opening regions 6 divided by the inner frame portion 5 of the frame body 3, and is integral with the frame body 3 via a metal layer 7.

[0019] This frame body 3 is configured so that the cross-sectional shape of the narrowest part of its inner frame portion 5 is a rectangle with the ratio (aspect ratio) of the thickness dimension T to the width dimension W being 0.8 / 4 or more and 2 / 4 or less. On the other hand, the cross-sectional shape of each of the outer frame portion 4 and the inner frame portion 5 of the frame body 3 except for the narrowest part is a rectangular cross-section in which the ratio of the thickness dimension T to the width dimension W (aspect ratio) is 0.8 / 90 or more.

[0020] The outer frame portion 4 and the inner frame portion 5 of the frame body 3 are formed to have a uniform thickness, and the thickness dimension is 0.2 mm to 6 mm, preferably 0.8 mm to 3 mm, more preferably 2 mm. Here, the reason why the thickness dimension is preferably 0.8 mm or more is that if the thickness dimension of each part of the frame body is less than 0.8 mm, the strength of the frame body cannot withstand the tension (tensile stress) inherent in the mask body, and there is a risk of deformation.

[0021] On the other hand, if the thickness dimension of each part of the frame exceeds 2 mm, a so-called shadow problem (the frame becomes an obstacle impeding the progress of the deposition material) may occur during deposition, and since the thickness of the master mold relative to the frame is usually 1 mm, handling of the frame after compression bonding becomes difficult, so it is preferable to keep the thickness dimension at 2 mm or less.

[0022] In this embodiment, the width dimension W1 of the narrowest part (minimum width part) of the inner frame part 5 is 4 mm, and the width dimension W2 of the widest part (maximum width part) is approximately 90 mm. If the width dimension of this minimum width part is less than 4 mm, the strength of the frame body cannot withstand the tension (tensile stress) inherent in the mask body, and there is a risk of deformation, so the width dimension is preferably 4 mm or more.

[0023] In addition, if the width dimension of the widest part exceeds 90 mm, the number of mask bodies (number of masks) that can be formed on one master mold will be excessively reduced, lowering the mask manufacturing efficiency, so it is preferable that the width dimension be 90 mm or less.

[0024] In this way, the frame 3 is formed so that the rectangular cross-sectional shape of the minimum width part of the inner frame part satisfies the condition that the ratio of the thickness dimension T to the width dimension W of the minimum width part is within the above-mentioned range. In this way, the aspect ratio of the cross-sectional shape of the minimum width part is within a predetermined range, an appropriate thickness that is not excessively large compared to the width is ensured, and the minimum width part is appropriately given resistance to deformation due to its own weight based on the cross-sectional shape, thereby making it difficult for the minimum width part to bend and ensuring strength against a force that tries to deform the frame 3 from the mask main body side, suppressing deformation of the frame 3 and the resulting effect on the mask main body 2, and improving the accuracy of the through-hole positions of the mask main body 2, enabling highly accurate deposition on the deposition target.

[0025] In addition, the cross-sectional shape of each part of the frame body 3 other than the minimum width part can provide the necessary bending rigidity, and the thickness relative to the width dimension is appropriately set while ensuring sufficient strength against forces from the mask body. This suppresses an increase in weight of the frame body 3 due to an unnecessarily large thickness (cross-sectional area), and prevents large deflections due to the weight of the entire deposition mask and its own weight.

[0026] On the other hand, the frame body 3 has a laminated structure in which a first frame member 3a and a second frame member 3b of the same shape are stacked and joined together with an adhesive between them. The first frame member 3a and the second frame member 3b are frame members formed from sheet metal material manufactured through the same sheet metal manufacturing process, and have warping due to internal strain of the sheet metal material resulting from the sheet metal manufacturing process, with the respective warping directions facing in opposite directions to form the laminated structure of the frame body 3.

[0027] In this way, the first frame member 3a and the second frame member 3b, which have the same shape and are formed by processing such as cutting from the thin metal plate material manufactured through the same thin plate manufacturing process, specifically the rolling process, are bonded together with an adhesive with their respective warping directions in the opposite directions, so that the warping is offset in the resulting frame body 3 and becomes flat (see FIG. 5). Note that in FIG. 5, the magnitude of the warping in the first frame member 3a and the second frame member 3b is exaggerated for ease of understanding, and the actual warping is extremely small. However, if these warpings were to appear in the frame body 3 as they are, they would affect the mask body 2 and deteriorate the accuracy of its position, and would be of a size that could hinder the high accuracy of the deposition mask, so the above-mentioned laminated structure is intended to eliminate the warping.

[0028] In this embodiment, the adhesive is a sheet-shaped uncured photosensitive dry film resist interposed between the first frame member 3a and the second frame member 3b. After the first frame member 3a and the second frame member 3b are joined, unnecessary resist portions other than the portion that will become the adhesive layer 3c between the first frame member 3a and the second frame member 3b are removed. In addition, various adhesives that are generally available can be used as the adhesive. Note that the planar shape, cross-sectional shape, and magnitude of warping of the first frame member 3a and the second frame member 3b may be different as long as the joining can achieve a flat state in which warping is offset, that is, the flatness and parallelism of the front and back surfaces of the frame body at the stage of becoming the frame body 3 are within an allowable range.

[0029] By joining the first frame member 3a and the second frame member 3b together with their respective warping directions facing in opposite directions to form a flat frame body 3, even if the thickness of the frame body 3 reaches a thickness that would cause warping if a simple sheet of thin plate material were used, it is possible to prevent unwanted deformation such as warping, and there is no adverse effect on the positional accuracy of the mask body, allowing deposition to be performed with high precision using this mask body.

[0030] The frame 3 is made of a material with a low thermal expansion coefficient, such as Invar, a nickel-iron alloy, or Super Invar, a nickel-iron-cobalt alloy, etc. The frame 3 is connected and integrated with the outer periphery 2b of the pattern formation region 2a of the mask body 2 by a metal layer 7 formed by electroforming so that they are not separated from each other.

[0031] When an Invar material or a Super Invar material is used as the material of the frame body 3, the extremely small thermal expansion coefficient of the material can satisfactorily suppress dimensional changes in the mask body 2 due to the heat effect in the deposition process. That is, even if the mask body 2 is made of, for example, nickel, which has a larger thermal expansion coefficient than that of general glass, which is the deposition substrate (not shown), there is no misalignment between the through-hole positions relative to the substrate when the deposition mask 1 is aligned with the deposition substrate at room temperature and the deposition position of the deposition material during actual deposition due to the difference in thermal expansion coefficient caused by the high temperature during deposition, and the small thermal expansion coefficient of the frame body 3 that holds the mask body 2 effectively suppresses dimensional changes and shape changes caused by the expansion of the mask body 2 when the temperature rises, and the alignment accuracy at room temperature can be well maintained even when the temperature rises during deposition.

[0032] The frame 3 may be made of a material having a low thermal expansion coefficient similar to that of the glass substrate, such as glass or ceramic. In this case, at least the surface of the material is made conductive.

[0033] The deposition mask 1 is manufactured by providing a primary pattern resist 14 on the surface of a matrix 10 corresponding to a non-positioned portion of the primary electrodeposition layer 15, forming a primary electrodeposition layer 15 on the matrix 10 by electroforming of an electrodeposited metal, forming a secondary pattern resist 18 covering a portion of the primary electrodeposition layer 15 corresponding to the pattern formation region 2a, and further arranging a frame 3 to surround the primary electrodeposition layer 15, and then forming a metal layer 7 by electroforming to cover the surface of the frame 3 and the surface of the outer periphery 2b of the primary electrodeposition layer 15. The primary electrodeposition layer 15 and the frame 3 are connected together via the metal layer 7 so as not to separate, and then separating the integrated primary electrodeposition layer 15, frame 3 and metal layer 7 from the matrix 10.

[0034] The matrix 10 used in the manufacturing process of the deposition mask 1 according to this embodiment is made of a conductive material such as stainless steel, brass, or steel, and supports the primary electrodeposition layer 15 constituting the mask body 2 and other components until separation in the manufacturing process of the deposition mask, and a primary pattern resist 14, a primary electrodeposition layer 15, a secondary pattern resist 18, and a metal layer 7 are formed on the front surface side at each stage of the manufacturing process of the deposition mask. When the primary electrodeposition layer 15 or the metal layer 7 is formed, electricity is passed through the matrix 10, and the primary electrodeposition layer 15 or the metal layer 7 is formed by electroforming (plating) on ​​the electrically conductive parts of the surface of the matrix 10 that are not covered by the resist.

[0035] The matrix 10 may be made of a material with a low thermal expansion coefficient, such as 42 alloy (42% nickel-iron alloy), Invar (36% nickel-iron alloy), SUS 430, etc. Alternatively, the matrix may be made of an insulating substrate, such as a glass plate or a resin plate, on whose surface a metal film made of a conductive metal, such as chromium or titanium, is formed.

[0036] In the manufacturing process of the deposition mask 1, once the metal layer 7 is formed on the matrix 10 by plating (see FIG. 11(B)), the matrix 10 is separated and removed therefrom (see FIG. 11(C)). When the matrix 10 is made of stainless steel, it is preferable to use a method in which it is physically peeled off from the deposition mask by applying force, and when the matrix 10 is made of another metal material, it is preferable to use an etching method in which a chemical solution is used to dissolve and remove the matrix 10. When etching, an etching solution is used that has selective etching properties such that the matrix 10 dissolves but the materials constituting the primary electrodeposition layer 15, the frame 3, and the metal layer 7 are not damaged.

[0037] The primary electrodeposition layer 15 is made of nickel or a nickel alloy such as nickel-cobalt that is suitable for electroforming, and is formed by electroforming in a portion of the matrix 10 where there is no primary pattern resist 14. In the deposition mask 1, the primary electrodeposition layer 15 is formed to constitute the mask body 2 that covers the surface of the deposition substrate except for deposition through-holes 8 that correspond to deposition target portions of the deposition substrate such as a light-emitting layer.

[0038] The primary pattern resist 14 is formed from an insulating material that is resistant to dissolution in the electrolyte used in electroforming the primary electrodeposition layer 15, and is disposed on the mold 10 in correspondence with non-positioned portions of the primary electrodeposition layer 15 that are preset in advance, and is removed after the primary electrodeposition layer 15 is formed (see Figures 6 and 7).

[0039] This primary pattern resist 14 is disposed on the mold 10 prior to the formation of the primary electrodeposition layer 15. A photosensitive resist, for example, a negative-type photosensitive dry film resist is disposed on the mold 10 to a predetermined thickness, for example, about 20 μm. With a mask film 12 of a predetermined pattern corresponding to the position of the mask body 2 of the deposition mask 1, i.e., the position of the primary electrodeposition layer 15, placed on the mold 10, the resist is hardened by exposure to ultraviolet light, and developed to remove the resist in the non-irradiated areas, and then formed into a shape corresponding to the non-positioned areas of the primary electrodeposition layer 15.

[0040] The secondary pattern resist 18 is formed of an insulating material that is resistant to dissolution in the electrolyte used in plating the metal layer 7 and preferably has a thickness in the range of 100 to 120 μm. It is disposed prior to the formation of the metal layer 7 so as to correspond to the non-placement portions of the metal layer 7 that are preset in the primary electrodeposition layer 15, and is removed after the metal layer 7 is formed (see Figures 8 and 9).

[0041] This secondary pattern resist 18 is formed by repeating a series of steps once or multiple times: a photosensitive resist, for example a negative-type photosensitive dry film resist, is adhered and arranged on the master 10 and the already arranged primary electrodeposition layer 15; and an ultraviolet ray exposure is performed with a mask film 17 of a predetermined pattern placed on it, which corresponds to the metal layer 7 and frame 3 positions of the deposition mask 1. The process is then performed to obtain the required resist thickness. After that, the photosensitive material of the non-irradiated parts is removed, and the secondary pattern resist 18 is formed in a shape corresponding to the non-arranged parts of the metal layer 7 (the pattern formation area 2a of the mask body 2).

[0042] The metal layer 7 is formed by plating and is made of nickel, a nickel-cobalt alloy, or the like, and is configured to be formed by plating on the exposed portions of the master mold 10, the already arranged primary electrodeposition layer 15, and the frame body 3 where the secondary pattern resist 18 is not provided.

[0043] This metal layer 7 joins the outer periphery 2b of the pattern formation region 2a of the mask body 2 to the frame 3. The metal layer 7 is laminated by plating on the upper surface of the mask body 2 relating to the outer periphery 2b of the pattern formation region. In detail, the metal layer 7 is formed on the upper surface of the outer periphery 2b of the pattern formation region 2a, the upper surface and side surface of the frame 3 facing the pattern formation region 2a, and in the gap between the mask body 2 and the frame 3, thereby integrally connecting the outer periphery 2b of the pattern formation region 2a to the periphery of the opening of the frame 3 so that they do not separate.

[0044] Next, a process for forming a frame in the deposition mask according to this embodiment and a process for manufacturing the entire deposition mask including the frame will be described. First, the process of forming the frame 3 used to reinforce the mask body 2 will be described.

[0045] First, a first frame member 3a and a second frame member 3b having the same shape are formed from a general thin metal sheet material that has been subjected to rolling processing, etc., in a cutting process using electric discharge processing, laser processing, etc. When cutting the second frame member 3b from the thin metal sheet material, the portion of the thin metal sheet material to be set as the second frame member 3b is provided so that its orientation is reversed with respect to the portion of the first frame member 3a, so that warping due to distortion occurs in opposite directions between the first frame member 3a and the second frame member 3b.

[0046] After cutting, an opening region 6 is provided in each cut-out member by etching, laser processing, or the like, to complete the first frame member 3a and the second frame member 3b. An adhesive that becomes the adhesive layer 3c is interposed between the obtained first frame member 3a and second frame member 3b, and they are joined together in a state where the warping directions are opposite, thereby obtaining a frame body 3 in which each portion has a predetermined cross-sectional shape.

[0047] As an adhesive for integrating the first frame member 3a and the second frame member 3b, for example, a sheet-shaped photosensitive dry film resist that has adhesiveness in an uncured state can be used. By using the same material as that used in the subsequent process, it is possible to prepare the same amount together and use a portion of the replenished material. This eliminates the need to prepare a commercially available adhesive or the like separately just for the adhesive layer, and thus avoids the costs associated with such a dedicated adhesive, which can reduce the manufacturing costs of the deposition mask. This is preferable.

[0048] If necessary, a process may be carried out in which the joined, integrated first frame member 3a and second frame member 3b are passed through a device capable of applying a clamping pressure to the stacked members, such as a pair of pressure rollers, to fix the joined state.

[0049] After bonding, unnecessary portions of the adhesive layer 3c, i.e., portions located outside the opening region 6 and the outer frame portion 4, are removed to complete the frame body 3. If the adhesive is a film resist, it will be removed by a development process.

[0050] Another adhesive layer 19 is provided on the completed frame body 3 in order to adhere it to the matrix 10. For example, a photosensitive dry film resist that has adhesiveness in an uncured state can be applied as this adhesive layer 19. After the film resist is applied to the frame body 3, the film resist located in the opening region 6 of the frame body 3 and the portion protruding from the outer frame portion 4 are removed, thereby obtaining the adhesive layer 19.

[0051] Meanwhile, in the manufacturing process of the deposition mask, first, a resist layer 11 is provided on the matrix 10 so as to correspond to the deposition through-holes 8 of the mask body 2, which are set in advance on the matrix 10, i.e., to the non-positioned portions of the primary electrodeposition layer 15 (see FIG. 6). Specifically, for example, one or several sheets of negative-type photosensitive dry film resist are laminated on the front surface side of the matrix 10 according to a predetermined thickness (e.g., about 20 μm) required for forming the primary electrodeposition layer 15, and the resist layer 11 is formed by thermocompression bonding (see FIG. 6(A)).

[0052] Then, a mask film (glass mask) 12 having a predetermined pattern corresponding to the arrangement position of the primary electrodeposition layer 15, such as having light-transmitting holes 12a corresponding to the deposition through-holes 8, is adhered to the surface of the resist layer 11, and then various processes are performed, such as curing by exposure to ultraviolet light (see Figures 6(B) and (C)), development to remove the resist from the masked non-irradiated parts, and drying. In this way, a primary pattern resist 14 corresponding to the non-arrangement parts of the primary electrodeposition layer 15 is formed on the matrix 10 (see Figure 7(A)). Incidentally, such primary pattern resist 14 can be formed by a lithography method using a photoresist or the like or by any other method, and the method of formation is not limited to the above.

[0053] The master mold 10 having this primary pattern resist 14 is placed in an electroforming tank prepared under specified conditions, and a primary electrodeposited layer 15, which will become the mask body 2, is formed, for example 8 μm thick, by electroforming an electrodeposited metal such as a nickel alloy on the surface of the master mold 10 not covered by the primary pattern resist 14 (exposed area), within the thickness of the primary pattern resist 14 (see Figure 7(B)).

[0054] Thereafter, the primary pattern resist 14 is dissolved and removed to obtain a primary electrodeposition layer 15 that will become the mask body 2 having a large number of independent deposition holes 8 forming a predetermined deposition pattern 9 (see Figure 7(C)).

[0055] After the primary electrodeposition layer 15 is obtained, a resist layer 16 having a thickness preferably in the range of 50 to 60 μm is disposed on the entire surface of the matrix 10 including the portion where the primary electrodeposition layer 15 is to be formed. Specifically, a negative type photosensitive dry film resist having a thickness of, for example, 56 μm is applied to the surface side of the matrix 10, and the main portion is cured by exposure to light. This process is repeated multiple times as necessary so that the secondary pattern resist 18 finally obtained from the resist layer 16 has a predetermined thickness set in advance, forming a single-layer or multilayer structure resist layer 16 made of one or multiple film resists.

[0056] The film resist is exposed each time a new film resist is applied. In detail, the mask film 17 having the light transmitting holes 17a corresponding to the pattern forming regions 2a of the mask body 2 is adhered to the surface of the newly applied film resist, and then the mask film 17 is hardened by exposure to ultraviolet light (see Fig. 8(B) and Fig. 9(A)). This process is repeated as necessary to obtain a resist layer 16a that has been hardened by exposure in the area corresponding to the pattern formation region 2a, and an unexposed resist layer 16b in other areas, each having a predetermined thickness.

[0057] In this embodiment, the process of applying a film resist and exposing it is repeated twice to form two resist layers 16 each having a thickness of 56 μm. Thereafter, a process is carried out to dissolve and remove the unexposed resist layer 16b that is exposed on the surface, thereby forming a secondary pattern resist 18 having a thickness of 112 μm that covers the pattern formation region 2a (see FIG. 9(C)).

[0058] After forming the secondary pattern resist 18 in this manner, the adhesive layer 19 is placed on the underside of the frame 3 already formed through the frame formation process, and is aligned and placed at a predetermined location on the primary electrodeposition layer 15 (see Figure 9(C)). In this state, the frame 3 can be temporarily fixed on the primary electrodeposition layer 15 due to the adhesiveness of the adhesive layer 19 so that it does not move easily.

[0059] The temporarily fixed frame 3 is subjected to a process of applying a load from above the frame 3 to pressure-bond the frame 3 so that the frame 3 does not easily separate from the primary electrodeposition layer 15 (see FIG. 10). Specifically, first, as the temporary pressure-bonding, a static load is applied to the frame 3 to press it against the matrix for a predetermined time. That is, a glass plate or the like weighing 50 kg or more, for example 105 kg, is placed on the frame 3 and left for one hour or more, for example 4 hours. Note that in this temporary pressure-bonding, an object other than a glass plate can be used as the static load as long as it can be placed on the frame 3.

[0060] Next, as the main pressure bonding, each part of the frame 3 is pressed evenly to reliably fix it to the primary electrodeposition layer 15. As a specific example, after removing the glass plate or the like, pressing is performed by moving a pressure roller (laminator) relative to the frame 3 and pressing with a pressure of 0.1 MPa or more, for example 0.6 MPa, back and forth on the frame 3 at least once, for example three times.

[0061] When pressing with a pressure roller for this full pressure bonding, if a rigid plate that does not easily deform, such as a plate made of SUS material, is placed between the frame 3 and the roller and pressing with the roller is performed through this plate, the force from the roller is dispersed by the plate and transmitted to the frame 3, which is less likely to result in bias in the pressing force than when pressing directly with the roller, and is therefore preferable.

[0062] Alternatively, a highly rigid plate and a sheet made of an elastic material such as rubber may be placed between the frame 3 and the roller with the sheet facing the frame 3, and the roller may apply pressure via the plate and the sheet. In this case, any unevenness in the gap between the plate and the frame caused by slight inclination, distortion, or unevenness of the plate surface can be absorbed by the elastic deformation of the sheet placed between the plate and the frame, and the force from the roller is transmitted more uniformly to the frame 3 through the sheet that is in close contact with the frame 3, so that the frame 3 can be more evenly and uniformly pressed against the primary electrodeposition layer 15, and the occurrence of gaps between the frame 3 and the primary electrodeposition layer 15 can be suppressed, preventing adverse effects such as abnormal growth of plating in the gaps when the metal layer 7 is formed.

[0063] In addition to using a pressure roller (laminator) to press the frame body 3 for the main pressure bonding, a press-type device can also be used that can press the frame body 3 by operating the pressing part only in the thickness direction of the frame body 3. This is preferable because there is no risk of the frame body being accidentally subjected to a force tangential to the roller (sideways) from the rolling roller, as occurs when a roller is used for pressing, which could cause the frame body to shift sideways.

[0064] After this compression bonding step, a metal layer 7 is formed by plating with an electrodeposited metal on the upper surface of the primary electrodeposition layer 15 that is not covered with the secondary pattern resist 18 and is exposed on the surface relating to the outer periphery 2b of the pattern formation region 2a, on the primary electrodeposition layer 15a on the lower side of the frame 3 and on each exposed surface of the matrix 10 that is exposed on the side thereof, and on the surface of the frame 3 (see FIG. 11(B)). This metal layer 7 enables the primary electrodeposition layer 15 and the frame 3 to be integrally connected so that they do not separate.

[0065] In this case, the metal layer 7 is formed to be thinner on the surface of the frame 3 than on the upper surface of the primary electrodeposition layer 15 exposed on the surface related to the outer periphery 2b of the pattern formation region 2a and on the surface of the matrix 10 exposed on the surface between the primary electrodeposition layer 15 and the frame 3. This difference in thickness occurs because the metal layer 7 is sequentially layered from the surfaces of the matrix 10 and the primary electrodeposition layer 15, and it is not until it exceeds the height dimension of the adhesive layer 19 and reaches the frame 3 that the frame 3 becomes conductive with the matrix 10 and the primary electrodeposition layer 15, and the formation of the metal layer 7 on the surface of the frame 3 begins.

[0066] When the formation of the metal layer 7 is completed, in the final step, the primary electrodeposition layer 15, the frame 3, and the metal layer 7 are peeled off from the matrix 10 (see FIG. 11(C)). Furthermore, the primary electrodeposition layer 15a present on the lower side of the frame 3 is removed together with the adhesive layer 19, and then the secondary pattern resist 18 is removed, completing the manufacture of the deposition mask 1. Note that, if the adhesive layer 19 remains on the lower side of the frame 3, it is removed when the secondary pattern resist 18 is removed.

[0067] In this way, the deposition mask according to this embodiment has a cross-sectional shape of the minimum width part in the inner frame part 5 of the frame body 3 with an appropriate relationship between the width and thickness, and thus the minimum width part has an appropriate bending rigidity, so that the minimum width part has a necessary and sufficient strength against the force from the mask body 2 side, and together with the other parts of the frame body 3 which are wider and stronger than the minimum width part, the frame body 3 as a whole is prevented from shifting from its original position, and the alignment state between the mask and the substrate to be deposited in the deposition process can be ensured, and deposition can be performed accurately at the appropriate position on the substrate to be deposited. In addition, because the minimum width part is less susceptible to bending deformation, the minimum width part is also prevented from bending due to its own weight, and deformation of the frame body 3 and its effect on the mask body 2 are suppressed.

[0068] In the deposition mask according to the embodiment, the mask body 2 is arranged to be located in each opening region 6 of the frame body 3, and has only one pattern-forming region 2a in which a large number of deposition through-holes 8 are provided. However, the mask body 2 may have a plurality of pattern-forming regions 2a as shown in FIG. 12. In this case, in order to reliably suppress the positional deviation of the mask body 2, it is preferable to form the width of each part of the frame body around the mask body to be larger than the width dimension allowed for the minimum width part to ensure sufficient rigidity. In addition, instead of the configuration in which only one mask body 2 is located in each opening region 6 of the frame body 3, a configuration in which multiple mask bodies 2 are arranged side by side in one opening region 6 may be used. In that case, the outer periphery of the mask body 2 is divided into a portion adjacent to the frame body 3 and a portion adjacent to the mask bodies, and in the portions adjacent to the mask bodies, the mask bodies are joined together by a metal layer formed by plating, similar to the portion in which the mask body 2 and the frame body 3 are joined together.

[0069] In addition, in the deposition mask according to the embodiment, the frame body 3 is configured to be formed by integrally joining the first frame member 3a and the second frame member 3b having the same shape. However, the present invention is not limited to this. The shapes of the first frame member 3a and the second frame member 3b may be made different from each other. For example, as shown in FIG. 13, the opening of the first frame member 3a on the side farther from the mask body 2 may be made larger than the opening of the second frame member 3b on the side closer to the mask body 2, and the width of each portion of the second frame member 3b may be made larger than that of the first frame member 3a, and the first frame member 3a and the second frame member 3b may be integrally joined to form the frame body 3. In this case, the opening region 6 of the frame 3 widens in a portion far from the mask body 2, and the peripheral portion surrounding the opening region 6 is recessed. As a result, during the deposition process, the peripheral portion around the opening region 6 of the frame 3 is less likely to become an obstacle impeding the progress of the deposition material as it passes through the opening region 6 of the frame 3 and the deposition holes 8 of the mask body 2 toward the substrate to be deposited. This eliminates the influence of the frame 3 on each deposition hole 8, allowing the deposition material to proceed smoothly, and deposition can be carried out more appropriately.

[0070] In addition, in the manufacturing of the deposition mask according to the embodiment, the metal layer 7 is formed so as to contact the primary electrodeposition layer 15 and the frame body 3, and the primary electrodeposition layer 15 and the frame body 3 are integrated by the metal layer 7. However, the present invention is not limited to this. The frame body 3 may be placed on the lower primary electrodeposition layer 15 with an adhesive stronger than the uncured film resist interposed therebetween, and the primary electrodeposition layer 15 and the frame body 3 may be integrated by adhesion. In this case, the integration of the primary electrodeposition layer, i.e., the mask body 2 and the frame body 3 can be easily performed, and the manufacturing efficiency of the mask can be improved. In this case, the bonding state of the mask body 2 and the frame body 3 can be made more preferable by further forming a metal layer so as to cover the surface of the mask body 2 and the surface of the frame body 3. In particular, by covering the surface (side portion) of the adhesive with a metal layer, it is possible to effectively prevent the adhesive from deteriorating due to cleaning treatment or temperature rise, and the bonding state of the mask body 2 and the frame body 3 can be maintained for a long period of time.

[0071] In addition, in the manufacture of the deposition mask according to the above embodiment, the frame body 3 is placed on the matrix 10, and then the metal layer 7 is formed on the surface of the frame body 3. However, this is not limited to the above. Before forming the metal layer 7 by plating, a resist may be disposed on a part or all of the upper surface of the frame body, so that the metal layer 7 is not formed on the entire upper surface of the frame body, and the metal layer 7 may be provided only on a part of the upper surface of the frame body or omitted except in necessary areas, thereby providing a stress relaxation portion on the surface of the frame body 3.

[0072] In this case, the metal layer 7 on the upper surface of the frame body 3 is not uniformly continuous but is partial and fragmentary, so that even if internal stress is generated in the metal layer, it will act partially and fragmentarily rather than on the entire frame body 3, making the frame body 3 less susceptible to adverse effects such as deformation, and ensuring a flat shape.

[0073] In addition, in the manufacturing of the deposition mask according to the above embodiment, after the primary electrodeposition layer 15 is formed, the metal layer 7 is formed without performing any particular surface treatment on the primary electrodeposition layer. However, this is not limited to the above. After the primary electrodeposition layer 15 is formed, and before the metal layer 7 is formed, an activation treatment such as acid immersion or electrolysis may be performed on a predetermined area of ​​the primary electrodeposition layer 15 where the metal layer is to be disposed in layers.

[0074] In this case, the bonding strength between the activated portion of the primary electrodeposition layer 15 and the metal layer 7 thereon can be significantly improved compared to the case where no treatment is performed. Also, instead of the activation treatment, a thin layer of strike nickel, matte nickel, or the like may be formed on a predetermined area of ​​the primary electrodeposition layer 15. This also improves the bonding strength between the thin layer-forming portion of the primary electrodeposition layer 15 and the metal layer 7 thereon.

[0075] In addition, in the manufacture of the deposition mask according to the above embodiment, the overlapping areas of the primary electrodeposition layer 15 or the frame body 3 and the metal layer 7 are configured to simply be in contact with each other through flat surfaces. Alternatively, a number of through holes or recesses may be provided around the entire outer periphery 2b of the pattern formation region 2a in the primary electrodeposition layer 15 (mask body 2), and the metal layer 7 formed on the outer periphery 2b of the primary electrodeposition layer 15 may be configured to fill the through holes or recesses so that the metal layer 7 partially embeds into the outer periphery 2b.

[0076] In this case, the metal layer 7 is present not only on the upper surface of the outer periphery 2b of the pattern formation region 2a but also in each through-hole or recess of the outer periphery 2b of the primary electrodeposition layer 15, thereby increasing the bonding strength between the primary electrodeposition layer 15 and the outer periphery 2b. This makes it possible to more firmly connect and integrate the mask body 2 and the frame 3 via the metal layer 7, reliably preventing the mask body 2 from accidentally falling off or shifting from the frame 3, and further improving the deposition accuracy and the reproducibility of the deposition-formed product.

[0077] In addition, in the manufacturing of the deposition mask according to the embodiment, the structure of the primary electrodeposition layer 15 to be the mask body 2 formed on the surface of the mold 10 that is not covered with the primary pattern resist 14 is not particularly described in detail, but the primary electrodeposition layer 15 can also be a two-layer structure of a dull nickel layer formed on the mold 10 side and a shiny nickel layer formed on the dull nickel layer. In detail, an electrodeposition layer made of dull nickel is formed by electroforming on the surface of the mold 10 that is not covered with the primary pattern resist 14, and then an electrodeposition layer made of shiny nickel is formed on the dull nickel layer by electroforming to form the primary electrodeposition layer 15. The relationship between the thicknesses of the dull nickel layer and the shiny nickel layer is such that if the dull nickel layer is too thick, the tension generated in the completed mask body 2 becomes excessively large, which may cause deformation of the frame body 3, so that the ratio of the thickness of the shiny nickel layer to the thickness of the dull nickel layer is preferably about 5 / 7.

[0078] The order of forming the dull nickel layer and the bright nickel layer can be reversed to form a two-layer structure in which the dull nickel layer is formed on the bright nickel layer. However, in the case of the latter two-layer structure in which the dull nickel layer is formed on the bright nickel layer, the probability of delamination occurring is considered to be higher than in the former two-layer structure, so it is preferable to adopt the former two-layer structure in which the bright nickel layer is formed on the dull nickel layer.

[0079] In this way, by forming a two-layer structure in which a shiny nickel layer is disposed on the upper side of a matte nickel layer and by making the matte nickel layer appropriately thicker than the shiny nickel layer, it is possible to increase the tension (tensile stress) that tends to contract inward in the completed mask body 2, and it is possible to obtain a deposition mask 1 with excellent heat resistance in which the mask body 2 does not deform even when affected by the expansion of each part due to heat.

[0080] If the primary electrodeposition layer is formed only from matte nickel, the tension generated in the completed mask body 2 may become excessively large, which may cause deformation of the frame body 3. In addition, since the surface of the matte nickel layer constituting the primary electrodeposition layer is rough, the bonding strength of plating or the like to the surface becomes large, which may cause problems such as the primary electrodeposition layer 15a and the metal layer 7 being unable to be separated during the mask manufacturing process. The primary electrodeposition layer having a two-layer structure in which a shiny nickel layer is formed on the above-mentioned matte nickel layer can avoid such problems. In the case of this two-layer structure in which a shiny nickel layer is formed on a matte nickel layer, the bonding strength of the shiny nickel layer part of the primary electrodeposition layer is smaller than that of the matte nickel layer, making it easier for the primary electrodeposition layer 15 to be separated from the metal layer 7. However, the bonding strength with the metal layer can be sufficiently ensured by forming a through hole in the primary electrodeposition layer, performing an activation process, or forming a thin layer of strike nickel, matte nickel, or the like.

[0081] Possible forms of the deposition mask according to the present disclosure will now be described. The deposition mask disclosed in the present invention includes a deposition mask including a plurality of mask bodies each having a large number of independent deposition through-holes arranged in a predetermined pattern, and a frame body arranged around the mask bodies, the frame body having a rectangular or square outer frame portion located at the outermost periphery and an inner frame portion dividing the inside of the outer frame portion into a plurality of opening regions, and being formed in a lattice shape as a whole, the mask bodies being located in the plurality of opening regions in the frame body, respectively, and being integrated with the frame body, the cross-sectional shape of the narrowest part of the inner frame body is a rectangular cross section with a ratio of thickness dimension to width dimension of 0.8 / 5 or more and 2 / 5 or less.

[0082] Thus, according to the disclosure of the present invention, by adjusting the cross-sectional shape of the minimum width part of the inner frame portion of the frame body so that the relationship between its width and thickness is appropriate, and by accurately imparting bending rigidity (resistance to bending deformation) to the minimum width part, it is possible to provide sufficient strength against forces from the mask body side, and together with the other parts of the frame body which are wider and stronger than this minimum width part, the frame body as a whole is prevented from shifting from its original position in each part of the mask body, ensuring the alignment of the mask and the substrate to be deposited during the deposition process, and enabling deposition to be performed with high precision in the appropriate position on the substrate to be deposited. Furthermore, since the minimum width portion is less susceptible to bending deformation, deflection due to its own weight is also suppressed, thereby suppressing deformation of the frame and the resulting effect on the mask body.

[0083] Furthermore, in the deposition mask disclosed herein, as necessary, the cross-sectional shape of each of the outer frame portion and the inner frame portion of the frame body other than the narrowest portion has a rectangular cross-section in which the ratio of thickness to width is 0.8 / 90 or more and is smaller than the ratio of thickness to width at the narrowest portion of the inner frame portion.

[0084] Thus, according to the disclosure of the present invention, by giving each portion of the frame body other than the minimum width portion an appropriate cross-sectional shape, and setting a thickness dimension at least to a certain degree relative to the width dimension at each portion of the frame body to impart the minimum necessary bending rigidity to make it less likely to bend, it is possible to ensure sufficient strength of the frame body against forces from the mask body, suppress deformation of the frame body and the resulting effect on the mask body, and improve the accuracy of the positions of the through holes in the mask body, enabling highly accurate deposition on the deposition target.

[0085] In the deposition mask according to the present disclosure, the frame is formed so that each portion has a thickness of 0.8 mm or more and 2 mm or less, as necessary.

[0086] According to the disclosure of the present invention, by setting the thickness dimension of the cross-sectional shape not to be too large within a realistic width dimension range that can obtain a cross-sectional shape that is less likely to bend in each part of the frame, it is possible to suppress the manifestation of deformation due to the frame's own weight and internal distortion in each part of the frame, thereby making it possible to obtain a frame with high precision and to perform deposition with high precision. In addition, by not increasing the thickness more than necessary, it is possible to suppress an increase in the weight of the frame, and to prevent deterioration in the handleability of the deposition mask.

[0087] In addition, in the deposition mask disclosed herein, as necessary, the frame body has a laminated structure in which a first frame member and a second frame member are stacked and integrated together, and the first frame member and the second frame member are warped frame members formed from a thin metal plate material, and the warping directions of the first frame member and the second frame member are opposite to each other.

[0088] Thus, according to the disclosure of the present invention, the frame is a laminated structure in which a first frame member and a second frame member made of a metal thin plate material are stacked and joined together, and the first and second frame members having warpage are stacked and arranged so that the warpage directions are opposite to each other to form the frame, so that the warpage is offset in the frame and a flat state is obtained, and a frame with improved flatness can be obtained at a lower cost, and deposition can be performed efficiently while improving the shape accuracy of the mask. Also, since the frame is configured by combining the first and second frame members, even if the thickness of the frame reaches a thickness that may cause warpage if a simple sheet of thin plate material is used, it is possible to prevent unnecessary deformation such as warpage, and a mask structure with increased strength can be obtained without adversely affecting the positional accuracy of the mask body, and deposition can be performed with high accuracy using this mask.

[0089] In the deposition mask according to the present disclosure, the frame may be formed by making the material of the inner frame portion different from the material of the outer frame portion, as necessary.

[0090] According to the disclosure of the present invention, by making the materials of the inner frame portion and the outer frame portion of the frame different from each other and imparting different properties to the inner frame portion and the outer frame portion, for example, when a material having a higher specific strength than the inner frame portion is used for the outer frame portion, the mask body can be efficiently reinforced by mainly suppressing deformation based on a force from the mask body side by the outer frame portion, and the positional accuracy of the mask body can be improved. In addition, when a material having a smaller linear expansion coefficient than the outer frame portion is used for the inner frame portion of the frame body, the displacement of each position of the mask due to thermal deformation of the mask body in a heated state during a deposition process or the like can be efficiently suppressed by the inner frame portion adjacent to the mask body, and the positional relationship between the mask and the substrate to be deposited at room temperature can be reliably maintained even in a heated state, and deposition can be performed with high accuracy. [Explanation of symbols]

[0091] 1. Deposition mask 2 Mask body 2a Pattern formation area 2b Outer edge 3 Frame 3a First frame member 3b Second frame member 3c adhesive layer 4 Outer frame 5 Inner frame 6 Opening area 7 metal layer 8 Vapor deposition hole 9. Deposition Pattern 10. Matrices 11 Resist layer 12 Masking film 12a Transparent hole 14 Primary pattern resist 15, 15a Primary electrodeposition layer 16 Resist layer 16a, 16b Resist layer 17 Masking film 17a Translucent hole 18 Secondary Pattern Resist 19 Adhesive layer

Claims

1. A frame body formed of a material having a low thermal expansion coefficient and used to reinforce a mask body, At least the first frame member and the second frame member are stacked and integrated to form a laminated structure, The overall shape has a rectangular outer frame portion located at the outermost periphery and an inner frame portion that divides the inside of the outer frame portion into a plurality of opening regions, The width of each portion of the second frame member is formed larger than that of the first frame member so that the opening area of ​​the first frame member is larger than the opening area of ​​the second frame member. Characteristic frame body.

2. In the frame body according to claim 1 , The first and second frame members are warped frame members, and the warping directions are opposite to each other. Characteristic frame body.

3. In the frame body according to claim 2, The first and second frame members are integrated to be in a flat state in which warping is offset. Characteristic frame body.

4. 4. The frame according to claim 1, The first frame member and the second frame member are joined via an adhesive layer. Characteristic frame body.

5. In the frame body according to claim 4, The adhesive used as the adhesive layer is a sheet-like resist having adhesiveness in an uncured state. Characteristic frame body.

6. A mask having a frame according to any one of claims 1 to 5 and a mask body having a large number of vapor deposition through-holes formed in a predetermined pattern. A deposition mask having the following characteristics.

Images