Method for manufacturing vapor deposition mask

Abstract

The present invention provides a method for manufacturing a vapor deposition mask, which can form a vapor deposition mask that reduces the influence of heat shrinkage in the vapor deposition process. In the method for manufacturing the vapor deposition mask, a resist mask is formed on a supporting substrate via a base metal layer, the resist mask having a predetermined pattern, and then, in the area of ​​the base metal layer where the resist mask is not formed, metal is precipitated by electroforming to form a mask body having a heat shrinkage of 8 ppm to 18 ppm at a temperature of 25° C. to 35° C., and after a mask frame is arranged on the mask body, the mask body is separated from the supporting substrate.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a vapor deposition mask, and more particularly to a method for manufacturing a vapor deposition mask in which a thin film-shaped mask body is provided on a mask frame. Background Art

[0002] As an example of a flat panel display device, a liquid crystal display device or an organic EL display device can be cited. These display devices are structures in which thin films of various materials such as insulators, semiconductors, and conductors are stacked on a substrate. By appropriately patterning and connecting these thin films, the function of a display device is realized.

[0003] Methods for forming thin films are roughly classified into gas phase method, liquid phase method, and solid phase method. Gas phase method is classified into physical gas phase method and chemical gas phase method. As a representative example of physical gas phase method, evaporation method is known. The simplest method of evaporation method is vacuum evaporation method. Vacuum evaporation method generates vapor of material (hereinafter collectively referred to as vaporization) by heating the material under high vacuum to sublimate or evaporate the material. In the area for depositing the material (hereinafter referred to as evaporation area), the vaporized material is solidified and deposited to obtain a thin film of the material. A thin film is selectively formed in the evaporation area. In order to prevent the material from being deposited in other areas (hereinafter referred to as non-evaporation areas), a mask (evaporation mask) is used for vacuum evaporation (refer to patent documents 1 and 2).

[0004] The vapor deposition mask is formed by joining a mask frame for fixing the mask body to a mask body formed with a vapor deposition pattern. The mask body is formed as follows: a photoresist layer with a predetermined pattern formed on a supporting substrate via a metal layer is used as a mask to form a plating film, and after joining the frame, the mask body is separated from the supporting substrate and the base metal layer.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2009-87840.

[0008] Patent document 2: Japanese Patent Application Publication No. 2013-209710. Summary of the invention

[0009] Problem that the invention aims to solve

[0010] In the evaporation atmosphere during the evaporation process, the mask body formed by electroforming will shrink, which increases the tensile stress. Due to the influence of this tensile stress, there is a problem of overall warping of the evaporation mask. If the evaporation mask warps, the evaporation mask cannot be adsorbed onto the magnet provided by the evaporation device. In addition, even if the evaporation mask can be adsorbed onto the magnet, the accuracy of the evaporation pattern will be reduced due to the deformation of the evaporation mask.

[0011] On the other hand, if the influence of the tensile stress of the mask body formed by electroforming is reduced to zero, wrinkles or warps may occur on the mask body, making it difficult to attach the vapor deposition mask to the vapor deposition device.

[0012] In view of the above problems, one object of one embodiment of the present invention is to form a vapor deposition mask capable of reducing the influence of the thermal shrinkage rate in the vapor deposition step.

[0013] Technical solutions to the problem

[0014] One embodiment of the present invention provides a method for manufacturing a vapor deposition mask, wherein a resist mask is formed on a supporting substrate through a base metal layer, the resist mask forming a prescribed pattern, and then, in an area of ​​the base metal layer where the resist mask is not formed, metal is precipitated by electroforming to form a mask body having a thermal shrinkage rate of 8 ppm to 18 ppm at a temperature of 25°C to 35°C, and after a mask frame is arranged on the mask body, the mask body is separated from the supporting substrate.

[0015] According to the present invention, it is possible to form a vapor deposition mask in which the influence of the heat shrinkage rate in the vapor deposition step is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1A This is a top view of a vapor deposition mask according to one embodiment of the present invention.

[0017] Figure 1B This is a top view of a vapor deposition mask according to one embodiment of the present invention.

[0018] Figure 1C This is a cross-sectional view of a vapor deposition mask according to one embodiment of the present invention.

[0019] Figure 2A It is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to one embodiment of the present invention.

[0020] Figure 2B It is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to one embodiment of the present invention.

[0021] Figure 2C It is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to one embodiment of the present invention.

[0022] Figure 2D It is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to one embodiment of the present invention.

[0023] Figure 2E It is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to one embodiment of the present invention.

[0024] Figure 2F It is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to one embodiment of the present invention.

[0025] Figure 2G It is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to one embodiment of the present invention.

[0026] Figure 2H It is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to one embodiment of the present invention.

[0027] Figure 3 This is a correlation diagram of the heat resistance temperature and spacing test of the evaporation mask.

[0028] Description of Reference Numerals

[0029] 10: evaporation mask, 110: mask body, 110-1: first surface, 110-2: second surface, 111: opening area, 112: non-opening area, 113: opening, 120: mask frame, 121: frame part, 122: grid part, 130: connection part, 210: supporting substrate, 210-1: first surface, 220: metal layer, 230: photoresist layer, 240: first plating layer, 250: protective layer, 260: temporary fixing part, 270: second plating layer, 280: adhesive layer. DETAILED DESCRIPTION

[0030] Hereinafter, various embodiments of the present invention will be described with reference to the drawings, etc. However, the present invention can be implemented in various forms within the scope of the gist thereof, and is not to be construed as being limited to the description of the embodiments illustrated below.

[0031] In order to make the description clearer, the drawings sometimes schematically show the width, thickness, shape, etc. of each part compared with the actual scheme. However, the example shown in the drawings is only an example, and unless the scheme shown in the drawings is specifically recorded, it does not limit the interpretation of the present invention. In this specification and each figure, the same symbols are marked for the same structures as those described in the above figure, and the detailed description is sometimes appropriately omitted.

[0032] In the present invention, when a plurality of films are formed by etching or light irradiation of a certain film, these plurality of films may have different functions and effects. However, these plurality of films are derived from films formed into the same layer by the same process, have the same layer structure and the same material. Therefore, it is defined that these plurality of films exist in the same layer.

[0033] In the present specification and claims, when expressing a scheme in which other structures are arranged on a certain structure, unless otherwise specified, it is defined as: the situation simply expressed as "on..." includes both the situation in which other structures are arranged directly above the certain structure in a manner of contacting the certain structure and the situation in which other structures are arranged above the certain structure with another structure in between.

[0034] (First Embodiment)

[0035] Reference Figure 1A to Figure 1C , the structure of a vapor deposition mask according to one embodiment of the present invention is described.

[0036] Figure 1A and Figure 1B 1 is a top view of a vapor deposition mask 10 according to one embodiment of the present invention. Specifically, Figure 1A is a plan view of the vapor deposition mask 10 as viewed from the first surface 110 - 1 of the mask body 110 . Figure 1B This is a plan view of the vapor deposition mask 10 as viewed from the second surface 110 - 2 on the opposite side of the first surface 110 - 1 of the mask body 110 . Figure 1C 1 is a cross-sectional view of a vapor deposition mask 10 according to one embodiment of the present invention. Specifically, Figure 1C It is along Figure 1A or Figure 1B The sectional view of the vapor deposition mask 10 taken along the line A1 - A2 is shown.

[0037] The evaporation mask 10 includes a mask body 110, a mask frame 120, and a connection portion 130. The mask body 110 has a first surface 110-1 and a second surface 110-2. Figure 1A and Figure 1B As shown, the mask frame 120 and the connection portion 130 are disposed on the first surface 110-1 of the mask body 110. In addition, the mask frame 120 and the connection portion 130 overlap with the mask body 110 when viewed from above. Figure 1A As shown in FIG. 1 , in a plan view from the first surface 110 - 1 of the mask body 110 , the mask frame 120 and the connection portion 130 are exposed from the mask body 110 . Figure 1BAs shown, the mask frame 120 and the connection portion 130 are not exposed from the mask body 110 when viewed from the second surface 110 - 2 of the mask body 110. In other words, the mask frame 120 and the connection portion 130 can also be covered by the mask body 110 when viewed from the second surface 110 - 2 of the mask body 110.

[0038] The mask body 110 includes an opening area 111 and a non-opening area 112. An opening 113 that passes through the mask body 110 and corresponds to the vapor deposition pattern is provided in the opening area 111. On the other hand, no opening 113 is provided in the non-opening area 112. The boundary between the opening area 111 and the non-opening area 112 is not necessarily clear. However, in many cases, because the opening 113 is provided according to the vapor deposition pattern, the interval between two adjacent openings 113 has a prescribed spacing. Therefore, the opening area 111 and the non-opening area 112 can be distinguished based on the prescribed spacing of the vapor deposition pattern.

[0039] The thickness of the mask body 110 is, for example, 1 μm or more and 10 μm or less. The mask body 110 is preferably formed of a material used in electroforming (or electrolytic plating). The mask body 110 is formed of a material such as nickel or a nickel alloy by electroforming.

[0040] When the vapor deposition process is performed using the vapor deposition mask 10, a vapor deposition substrate is set on the second surface 110-2 of the mask body 110. For example, a circuit substrate on which transistors and the like are formed is used as the vapor deposition substrate. The vapor deposition mask 10 is fixed in the chamber of the vapor deposition device in a state where the vapor deposition substrate is sandwiched in the middle and adsorbed by a magnet set in the vapor deposition device. In the vapor deposition device, a vapor deposition source is set on the first surface 110-1 side of the mask body 110. By heating the vapor deposition source, the organic material is heated and sublimated or evaporated. In such a vapor deposition process, the organic material is deposited only through the opening 113 of the mask body 110. Therefore, a pattern (vapor deposition pattern) corresponding to the opening 113 is formed on the vapor deposition substrate. The opening 113 can be set corresponding to the arrangement of pixels of the display device, for example, it can be configured in a matrix.

[0041] The mask frame 120 includes a frame portion 121 located at the periphery of the vapor deposition mask 10 and a grid portion 122 located inside the frame portion 121. In the mask frame 120, the inner side of the frame portion 121 is open, and the opening is divided by the grid portion 122 configured in a lattice shape. If the size of the mask frame 120 becomes larger, it is sometimes difficult to maintain the parallelism of the mask frame 120 at a predetermined reference due to warping or twisting of the frame portion 121. In the vapor deposition mask 10, the rigidity of the frame portion 121 is increased by the grid portion 122, so that the parallelism of the mask frame 120 can be maintained at a predetermined reference. In addition, when the size of the vapor deposition mask 10 is small and the rigidity of the frame portion 121 is sufficiently high, the grid portion 122 may not be provided.

[0042] The mask frame 120 may be formed by integrating the frame portion 121 and the lattice portion 122 , or may be formed by separately manufacturing the frame portion 121 and the lattice portion 122 and welding the frame portion 121 and the lattice portion 122 .

[0043] exist Figure 1A In the embodiment, the mask frame 120 is divided into 12 openings by the sash portion 122, but the number of divided openings is not limited thereto. The number of divided openings can be appropriately determined according to the size of the vapor-deposited substrate or the vapor deposition pattern. In addition, the configuration of the sash portion 122 is not limited to a lattice shape. In the case where the mask frame 120 is a rectangle having short sides and long sides, it is easier to cause warping or distortion on the long sides than on the short sides. Therefore, it is preferred to set the sash portion 122 in a manner that connects the opposing long sides. In addition, the configuration of the sash portion 122 can also be set to a shape corresponding to the vapor deposition pattern.

[0044] The width of the frame 121 and the width of the grid portion 122 can be appropriately determined according to the size of the vapor deposition mask 10. In order to maximize the area of ​​the vapor deposition pattern, the width of the grid portion 122 is preferably smaller than the width of the frame 121.

[0045] The thickness of the mask frame 120 is, for example, 10 μm to 2000 μm. The mask frame 120 is preferably made of a material with a small thermal expansion coefficient. The mask frame 120 can be made of, for example, Invar containing iron and nickel or Super Invar containing iron, nickel, and cobalt.

[0046] The connection part 130 can connect the mask body 110 and the mask frame 120. Figure 1C As shown, the mask body 110 and the mask frame 120 are in direct contact, but the mask body 110 and the mask frame 120 are bonded or joined. The mask body 110 and the mask frame 120 are joined by the connecting portion 130, and the mask body 110 and the mask frame 120 are connected and fixed via the connecting portion 130.

[0047] The connection portion 130 only needs to be provided on at least a portion of the side surface of the frame portion 121 or the lattice portion 122 of the mask frame 120. However, in order to increase the bonding strength between the mask body 110 and the mask frame 120, the connection portion 130 is preferably provided on more than 1 / 2 of the side surface of the frame portion 121 or the lattice portion 122, and more preferably provided on the entire surface of the side surface of the frame portion 121 or the lattice portion 122. In addition, the connection portion 130 is preferably formed of a material used in electroforming. The connection portion 130 is formed of a material such as nickel or a nickel alloy. The material of the connection portion 130 may be the same as or different from the material of the mask body 110.

[0048] As for the evaporation mask 10, as described above, the mask body 110 and the mask frame 120 are in direct contact, but the mask body 110 and the mask frame 120 are not directly fixed. Therefore, even if the mask body 110 and the mask frame 120 are made of materials with different thermal expansion coefficients, the stress of the mask body 110 or the mask frame 120 can be dispersed. In addition, the mask body 110 and the mask frame 120 may not be in direct contact, and a gap may be provided between the mask body 110 and the mask frame 120. Even in this case, the stress of the mask body 110 or the mask frame 120 can be dispersed.

[0049] In the evaporation atmosphere during the evaporation process, the mask body formed by electroforming shrinks, and the tensile stress increases. There is a problem that the evaporation mask as a whole warps due to the influence of this tensile stress. If warping occurs on the evaporation mask, the evaporation mask cannot be adsorbed onto the magnet provided in the evaporation device. In addition, even if the evaporation mask can be adsorbed onto the magnet, the accuracy of the evaporation pattern is reduced due to the deformation of the evaporation mask.

[0050] On the other hand, if the influence of the tensile stress of the mask body formed by electroforming is set to zero, wrinkles will be generated in the mask body or the mask body will bend, which makes it difficult to adsorb the vapor deposition mask to the vapor deposition device.

[0051] In addition, in the vapor deposition process, heat higher than normal temperature (25° C.) is applied to the vapor deposition mask. The mask body is heated and shrinks, thereby reducing the accuracy of the vapor deposition pattern.

[0052] The larger the size of the vapor deposition mask, the more obvious the above-mentioned defect of the vapor deposition mask appears.

[0053] Therefore, one of the objects of one embodiment of the present invention is to provide a vapor deposition mask 10 that reduces the influence of the thermal shrinkage rate in the vapor deposition process.

[0054] The vapor deposition mask 10 according to one embodiment of the present invention adjusts the thermal shrinkage rate of the mask body 110 to be 8 ppm or more and 18 ppm or less. Here, the thermal shrinkage rate is a value obtained by the following formula.

[0055] Thermal shrinkage (ppm)

[0056] =(shrinkage amount of the vapor deposition mask after the vapor deposition step (μm) / length of the vapor deposition mask before the vapor deposition step (μm))……(Formula 1)

[0057] In addition, in this embodiment, the shrinkage of the vapor deposition mask after the vapor deposition process refers to the shrinkage when the treatment is performed for a maximum of 240 seconds at a temperature of 25°C to 35°C. In addition, the above-mentioned shrinkage is the change in the vapor deposition mask in a direction parallel to the length. For example, two structures are formed on the vapor deposition mask, and the distance between the two structures is measured. Thereafter, after the vapor deposition mask is treated for a maximum of 240 seconds at a temperature of 25°C to 35°C, the distance between the two structures is measured. The amount of change in the distance between the two structures before and after the treatment is equivalent to the shrinkage.

[0058] By bringing the thermocouple into contact with the mask body 110, the temperature of the mask body 110 can be measured. In the evaporation process, the mask body 110 is heated to, for example, 30°C or more. At this time, a force to shrink is generated in the mask body 110. If the thermal shrinkage rate of the mask body exceeds 18ppm, the entire evaporation mask may be warped due to the increase in the tensile stress generated in the mask body. If the warping amount of the evaporation mask increases, the evaporation mask may not be adsorbed to the evaporation device by the magnet. In addition, if the thermal shrinkage rate is lower than 8ppm, when the evaporation mask 10 is adsorbed to the evaporation device, undesirable conditions such as wrinkles on the mask body 110 or bending of the mask body may occur. Therefore, before and during the evaporation process, it is preferred that the thermal shrinkage rate of the mask body 110 be controlled to be above 8ppm and 18ppm so that the evaporation mask can maintain appropriate tensile stress.

[0059] In addition, it is necessary to control the allowable warping amount of the mask body according to the size of the vapor-deposited substrate. For example, when the size of the mask body 110 in contact with the vapor-deposited substrate is G4.5H (450mm×730mm), the warping amount of the mask body is preferably set to less than 2mm. When the size of the mask body 110 in contact with the vapor-deposited substrate is G6H (1500mm×925mm), the warping amount of the mask body is preferably set to less than 1.5mm. In addition, when the size of the vapor-deposited substrate is G6 (1500mm×1850mm), the warping amount of the mask body is preferably set to less than 1.0mm.

[0060] Here, the warpage refers to the difference in height between the highest position and the lowest position on the first surface 110-1 relative to the plane when the first surface 110-1 of the mask body is set up and placed on a plane. In terms of the positive and negative of the warpage, the case where the first surface 110-1 of the mask body bulges downward is set as positive, and the case where it bulges upward is set as negative. Typically, in terms of the highest position and the lowest position, one side refers to the vicinity of the central part of the mask body, and the other side refers to the vicinity of the end of the mask body. For example, the warpage of the vapor deposition mask can be measured with a laser displacement sensor. For example, when G4.5H is used as the size of the vapor deposition substrate, if the warpage exceeds 2mm, it is difficult to adsorb the vapor deposition mask to the vapor deposition device. Relative to the length of the long side direction of the mask body of 820mm, the shrinkage of the mask body (plating layer) that can set the warpage of the mask body to less than 2mm is about 15μm. If the shrinkage amount of 15 μm and the length of the mask body in the long side direction of 820 mm are applied to the formula (1), the shrinkage rate at this time is 18.3 ppm.

[0061] According to the vapor deposition mask 10 of one embodiment of the present invention, the heat shrinkage rate of the mask body 110 is controlled. Therefore, the vapor deposition mask 10 can be adsorbed onto the vapor deposition device without causing wrinkles or sagging in the mask body 110. In addition, during the vapor deposition process, even if the mask body 110 is heated, the heat shrinkage rate of the mask body 110 is controlled, so that the warping amount of the vapor deposition mask 10 can be suppressed from exceeding 2 mm and becoming larger. As a result, it is possible to suppress the reduction in the accuracy of the vapor deposition pattern due to the increase in the warping amount of the vapor deposition mask 10.

[0062] Next, refer to Figure 2A to Figure 2H , a method for manufacturing a vapor deposition mask according to one embodiment of the present invention is described. Figure 2A to Figure 2C This is a diagram for explaining the first electroforming step.

[0063] First, if Figure 2A As shown, a metal layer 220 is formed on a support substrate 210 , and a photoresist layer 230 having a predetermined pattern is formed on the metal layer 220 .

[0064] The support substrate 210 supports each layer in the manufacturing process of the vapor deposition mask 10. Therefore, the support substrate 210 is preferably a rigid substrate. The manufacturing process of the vapor deposition mask 10 includes a process of heating the support substrate 210. If the support substrate 210 expands or contracts due to the heat treatment, not only will the photoresist layer 230 formed on the support substrate 210 be misaligned, but it may also be stress-peeled. Therefore, in order to stabilize the manufacturing process of the vapor deposition mask 10, the support substrate 210 is further preferably a rigid substrate with a small thermal expansion coefficient. The material of the support substrate 210 is, for example, stainless steel (SUS304 or SUS430, etc.), 42 alloy, Invar, super Invar or stainless Invar, etc.

[0065] The metal layer 220 can function as a base metal in the first electroforming step. The material of the metal layer 220 is, for example, nickel or a nickel alloy. The metal layer 220 is formed by sputtering or the like.

[0066] In addition, the metal layer 220 is finally separated and removed. Therefore, in order to facilitate separation of the metal layer 220, a conductive layer may be provided on the metal layer 220. In this case, the metal layer 220 is easily separated by peeling off the conductive layer.

[0067] The deposition mask 10 can also be manufactured by electroless plating instead of electroforming. In this case, an insulating layer can be used instead of the metal layer 220.

[0068] The photoresist layer 230 functions as a mask in the first electroforming process. The photoresist layer 230 is formed by placing one or more photosensitive dry film resists on the metal layer 220 in a manner having a predetermined film thickness and by thermocompression bonding. The photosensitive dry film resist may also be either positive or negative. In addition, the following description assumes that the photosensitive dry film is negative.

[0069] The photoresist layer 230 has a pattern corresponding to the opening pattern of the mask body 110 of the vapor deposition mask 10. The pattern of the photoresist layer 230 is formed by photolithography. That is, the pattern of the photoresist layer 230 is formed by bringing a photomask into close contact with a dry film resist, irradiating the dry film with ultraviolet rays, and melting and removing the unexposed portion.

[0070] Next, if Figure 2B As shown, the first plating layer 240 is formed using the photoresist layer 230 as a mask. The first plating layer 240 is formed by electroforming (plating).

[0071] The plating solution used in electroforming is generally a plating solution in which one or more metal salts, organic electrolytes, acids such as phosphoric acid, and various electrolytes such as alkaline substances are dissolved in a solvent. Examples of the solvent include water, alcohols such as methanol and ethanol, cyclic carbonates such as ethylene carbonate and propylene carbonate, linear carbonates such as dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate, and mixed solvents thereof.

[0072] Metal salts can be appropriately selected in consideration of the metal to be precipitated, alloys, etc. As the metal of metal salts, for example Cu, Zn, Ga, As, Cr, Se, Mn, Fe, Co, Ni, Ag, Cd, In, Sn, Sb, Te, Ru, Rh, Pd, Au, Hg, Tl, Pb, Bi, W, Po, Re, Os, Ir, Pt, etc. can be enumerated. Among them, Ni, Ag, Au, Cd, Co, Cr, Cu, Fe, Sn, Zn, and Ni is particularly preferred. In addition, these metals are used alone, or two or more combinations can be used.

[0073] Specific examples of the main component of the plating solution, i.e., the metal salt, include nickel sulfate, nickel sulfate, nickel chloride, nickel sulfamate, nickel chloride, etc. as nickel plating solutions. Plating solutions using these metal salts alone or in combination of two or more may also be used. Plating solutions to which cobalt sulfamate is added may also be used in the above-mentioned nickel plating solution.

[0074] In the first electroforming step, the metal layer 220 and the photoresist layer 230 are placed in an electroforming tank made with the above-mentioned plating solution under predetermined conditions. Then, the metal plating is formed from the surface of the metal layer 220 not covered by the photoresist layer 230 to the height of the photoresist layer 230. Examples of the material of the first plating layer 240 include nickel or a nickel alloy.

[0075] In this embodiment, nickel sulfamate is preferably used as the metal salt. By using nickel sulfamate as the metal salt and adjusting the current density, the internal stress of the precipitated nickel film can be adjusted. In addition, the internal stress can also be reduced by adding a stress reducer such as saccharin to the plating solution.

[0076] In addition, by adding impurities to the nickel plating solution, the internal stress of the nickel film can be adjusted. By adding, for example, a compound containing a sulfur atom in the molecule as an organic chemical species to the nickel plating solution, compressive stress can be generated in the nickel film. In addition, by adding, for example, iron (II, III) ions, zinc ions and their hydroxides, chromate ions as inorganic chemical species, or adding 2-butyne 1,4-diol and 2-propyne 1-ol having double bonds in the molecule as organic chemical species to the nickel plating solution, tensile stress can be generated in the nickel film. In the case of applying compressive stress to the nickel film, it is preferred to add impurities that cause compressive stress to the nickel plating solution. In addition, in order to adjust the stress of the nickel film, in addition to impurities that cause compressive stress, impurities that cause tensile stress can also be added.

[0077] Next, if Figure 2C As shown, the photoresist layer 230 is peeled off from the surface of the metal layer 220. The photoresist layer 230 is peeled off by, for example, an amine-based stripping solution. Thus, a first plating layer 240 having an opening region 111 and a non-opening region 112 is formed. The first plating layer 240 can control the thermal shrinkage rate to be greater than 7 ppm and less than 15 ppm.

[0078] The first plating layer 240 formed by electroforming may be polished before removing the photoresist layer 230. By polishing the first plating layer 240, the surface of the first plating layer 240 can be planarized.

[0079] In addition, the first plating layer 240 corresponds to the mask main body 110 of the vapor deposition mask 10. Therefore, hereinafter, the first plating layer 240 is described as the mask main body 110 for convenience.

[0080] Figure 2D and Figure 2E This is a diagram for explaining the mask frame bonding process.

[0081] like Figure 2D As shown, a protective layer 250 is formed on the opening region 111 of the mask body 110. The protective layer 250 can prevent particles generated by the process described later from entering the opening 113 of the opening region 111 and blocking the opening 113. In addition, the protective layer 250 can function as a mask in the second electroforming process described later. The same material as the photoresist layer 230 is used as the protective layer 250.

[0082] Next, if Figure 2EAs shown, an adhesive layer 280 is provided on the non-opening area 112 of the mask body 110, and the mask frame 120 is bonded on the adhesive layer 280. Since the adhesive layer 280 is removed in the process described later, it is not necessary to be completely cured. For example, vinyl acetate resin, ethylene vinyl acetate resin, epoxy resin, cyanoacrylate resin or acrylic resin can be used as the material of the adhesive layer 280. In addition, a dry film resist can also be used as the material of the adhesive layer 280. In the case of using a dry film resist as the material of the adhesive layer 280, the dry film resist can also be slightly exposed. By exposing the dry film resist, the dry film resist can be easily removed in the process described later. The mask frame 120 is configured in a manner that the frame portion 121 and the lattice portion 122 do not overlap with the opening area 111 of the mask body 110. That is, the mask frame 120 is configured on the non-opening area 112 of the mask body.

[0083] Figure 2F This is a diagram for explaining the second electroforming step.

[0084] like Figure 2F As shown, a second plating layer 270 is formed to connect the mask body 110 and the mask frame 120. The second plating layer 270 can be formed by electroforming by applying electricity to the metal layer 220 or the mask frame 120. The second plating layer 270 can be formed by the same method as the first plating layer 240. Since the second plating layer 270 is set to fill the opening of the non-opening area 112, the second plating layer 270 is in contact with the metal layer 220. In addition, the second plating layer 270 connects the upper surface and the side surface of the non-opening area 112 of the mask body 110 and the mask frame 120. That is, the second plating layer 270 corresponds to the connecting portion 130 of the vapor deposition mask 10. Therefore, hereinafter, for convenience, the second plating layer 270 is described as the connecting portion 130.

[0085] Figure 2G and Figure 2H This is a diagram for explaining the step of separating the support substrate.

[0086] like Figure 2G As shown, the protective layer 250 is peeled off. The protective layer 250 can be peeled off by the same method as the photoresist layer 230.

[0087] Next, if Figure 2H As shown, the support substrate 210 and the metal layer 220 are separated from the mask main body 110. The support substrate 210 and the metal layer 220 may be separated at the same time, or the metal layer 220 may be separated after the support substrate 210 is separated.

[0088] Through the above steps, the vapor deposition mask 10 in which the mask frame 120 and the connection portion 130 overlap with the mask body 110 can be manufactured.

[0089] In addition, the order of the steps in the method for manufacturing the vapor deposition mask 10 is not limited to the above order. Figure 2D The protective layer 250 shown can also be formed by using Figure 2E The mask frame 120 shown is tightly attached to the mask body. Figure 2G The peeling of the protective layer 250 shown can also be performed in Figure 2H The support substrate 210 shown is then separated.

[0090] According to the method for manufacturing a vapor deposition mask according to one embodiment of the present invention, the heat shrinkage rate of the mask body 110 can be controlled. Therefore, the vapor deposition mask 10 can be adsorbed onto the vapor deposition device without causing wrinkles or sagging on the mask body 110. In addition, during the vapor deposition process, even if the mask body 110 is heated, the amount of warping of the vapor deposition mask 10 can be suppressed from increasing because the heat shrinkage rate is controlled. It can be suppressed that the vapor deposition mask 10 cannot be adsorbed onto the vapor deposition device or the accuracy of the vapor deposition pattern is reduced due to the increase in the amount of warping of the vapor deposition mask 10.

[0091] Example

[0092] In this example, the results of investigating the correlation between the heat resistance temperature of the vapor deposition mask and the amount of shrinkage of the vapor deposition mask according to one embodiment of the present invention will be described.

[0093] The mask body of the vapor deposition mask of this example is a nickel-plated layer with a thickness of 5 μm. The size of the mask body is G4.5H (450 mm×730 mm), and the length of the mask body in the long side direction, which is the reference for measuring the shrinkage amount, is 820 mm.

[0094] Figure 3 This is a correlation diagram between the heat resistance temperature and the shrinkage amount of each of 23 vapor deposition masks produced under the same conditions in this example. The horizontal axis represents the shrinkage amount (μm) of the vapor deposition mask, and the vertical axis represents the heat resistance temperature (°C).

[0095] like Figure 3 As shown in FIG. 1 , it was confirmed that there was a negative correlation relationship that the higher the heat resistance temperature, the more the vapor deposition mask shrank. In addition, the linear model representing this relationship was y=-0.4672x+26.413.

[0096] According to the above linear model, the shrinkage of the vapor deposition mask when the temperature of the vapor deposition mask is 30°C can be calculated by extrapolation. It can be seen that the shrinkage of the vapor deposition mask when the temperature of the vapor deposition mask is 30°C is -7.6 μm. Therefore, by applying the shrinkage of 7.6 μm and the length of the long side direction of the mask body of 820 mm to formula (1), it can be seen that the thermal shrinkage rate (ppm) is 8.5 ppm.

[0097] When the size of the mask body is G4.5H (450 mm × 730 mm), if the heat shrinkage rate of the mask body is less than 8 ppm, wrinkles may be formed on the mask body or the mask body may be bent. In other words, when the heat shrinkage rate is less than 8 ppm, the vapor deposition mask cannot be adsorbed onto the vapor deposition device.

[0098] Furthermore, the above linear model shows that the shrinkage of the deposition mask is 18.4 μm when the temperature of the deposition mask is 35° C. By applying the shrinkage of 18.4 μm and the length of the mask body in the long side direction of 820 mm to equation (1), the thermal shrinkage rate (ppm) is 22.4 ppm.

[0099] As described above, the shrinkage of the mask body that can set the warpage of the mask body to less than 2 mm is about 15 μm relative to the length of the long side direction of the mask body of 820 mm. Therefore, if the shrinkage exceeds 15 μm, the warpage of the mask body may exceed 2 mm. Therefore, the upper limit of the shrinkage of the mask body is preferably 15 μm. If the shrinkage of the mask body of 15 μm and the length of the long side direction of the mask body of 820 mm are applied to formula (1), the thermal shrinkage rate at this time is 18.3 ppm.

[0100] The vapor deposition mask of this example shows that the vapor deposition process can be performed well by controlling the heat shrinkage rate of the mask body at 25° C. or higher and 35° C. or lower to about 8 ppm to 18 ppm.

[0101] As embodiments of the present invention, the above-mentioned embodiments can be appropriately combined as long as they are not contradictory. In addition, those skilled in the art who have appropriately added, deleted or changed the design of the constituent elements based on the embodiments, or added, omitted or changed the conditions of the processes, are also included in the scope of the present invention as long as they have the gist of the present invention.

[0102] Even if there are other effects different from the effects brought about by the schemes of the above-mentioned embodiments, effects that are obvious from the description of this specification or effects that can be easily predicted by those skilled in the art should be understood as being brought about by the present invention.

Claims

1. A method for manufacturing a vapor deposition mask, characterized in that: A resist mask is formed on the support substrate via the base metal layer, wherein the resist mask has a predetermined pattern. In the area of ​​the base metal layer where the resist mask is not formed, metal is deposited by electroforming to form a mask body having a heat shrinkage rate of 8 ppm to 18 ppm at a temperature of 25° C. to 35° C., After the mask frame is arranged on the mask body, the mask body is separated from the support substrate. The tensile stress and compressive stress generated in the deposited metal film are adjusted by adding impurities to the plating solution used in the electroforming so as to control the thermal shrinkage rate of the formed mask body to be not less than 8 ppm and not more than 18 ppm. As the impurity, a compound containing a sulfur atom in the molecule is added to the plating solution to generate compressive stress, and one selected from 2-butyne 1,4-diol and 2-propyne 1-ol is added to the plating solution as an organic chemical species, or one selected from divalent iron ion, trivalent iron ion, zinc ion and their hydroxides, chromate ion is added to the plating solution as an inorganic chemical species to generate tensile stress.

2. The method for manufacturing a vapor deposition mask according to claim 1, wherein: The thermal shrinkage ratio is represented by the shrinkage amount of the vapor deposition mask after the vapor deposition step / the length of the vapor deposition mask before the vapor deposition step.

3. The method for manufacturing a vapor deposition mask according to claim 1, wherein: Nickel or a nickel alloy is used as the metal deposited by the electroforming, and a sulfamic acid solution is used as the electrolyte.

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