Method for manufacturing evaporation mask

Abstract

The technical problem to be solved by the present invention is to provide a method for manufacturing a vapor deposition mask that can improve the positional accuracy of the opening area. In the vapor deposition mask manufacturing method, a photoresist layer having a predetermined pattern is formed on a support substrate via a base metal layer. The support substrate is arranged so that its first surface is perpendicular to a horizontal plane. A first warpage of the support substrate is measured. A mask body is formed by depositing metal by electroforming in an area of ​​the base metal layer where the photoresist layer is not formed. The support substrate is arranged so that its first surface is perpendicular to the horizontal plane. A second warpage of the support substrate is measured. The shrinkage rate of the mask body is calculated based on a change in the warpage calculated based on the first and second warpage amounts and an internal stress of the support substrate calculated based on the change in the warpage amount.

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 having a thin film-shaped mask body on a mask frame. Background Art

[0002] Examples of flat-panel displays include liquid crystal displays and organic EL displays. These displays are structures formed by stacking thin films composed of various materials, such as insulators, semiconductors, and conductors, on a substrate. By appropriately patterning and connecting these thin films, they can function as a display device.

[0003] Methods for forming thin films can be roughly divided into gas phase method, liquid phase method, and solid phase method. Gas phase method can be divided 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 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 solidifies and deposits, thereby obtaining a thin film of the material. In order to selectively form a thin film in the evaporation area and not deposit the material in the area outside the evaporation area (hereinafter referred to as non-evaporation area), a mask (evaporation mask) is used for vacuum evaporation (see Japanese Patent Application Publication No. 2009-87840 and Japanese Patent Application Publication No. 2013-209710).

[0004] In a vapor deposition mask, a mask frame is bonded to a mask body with a vapor deposition pattern formed thereon, securing the mask body. The mask body can be formed by forming a deposition film using a photoresist layer having a predetermined pattern formed on a support substrate with a metal layer interposed therebetween as a mask, bonding it to the mask frame, and then separating the mask body from the support substrate and base metal layer. Summary of the Invention

[0005] Technical problem to be solved by the invention

[0006] During the mask body manufacturing process, when the fine patterned plating layer formed on a support substrate by electroplating is separated from the support substrate, the stress on the plating layer causes the plating layer to shrink. This can cause the opening area to deviate from the desired position, making it important to manage the plating layer's shrinkage. However, without separating the plating layer from the support substrate, the plating layer's shrinkage cannot be measured. Therefore, it takes several days to feed back the measured plating layer shrinkage results to the fine pattern formation process or the plating layer formation process.

[0007] On the other hand, there are methods for measuring the shrinkage of the coating by forming a coating on a simulated support substrate and immediately peeling it off. In this case, the coating must be thick enough to prevent damage or deformation even when peeled off independently. However, the coating peeled off from the simulated support substrate is in a different state than the coating that constitutes the actual mask body, making it difficult to accurately evaluate the shrinkage.

[0008] In view of the above-mentioned problems, one object of one embodiment of the present invention is to provide a method for manufacturing a vapor deposition mask capable of improving the positional accuracy of an opening region.

[0009] Means for solving technical problems

[0010] In a method for manufacturing a vapor deposition mask according to one embodiment of the present invention, a photoresist layer having a predetermined pattern is formed on a supporting substrate via a base metal layer, the supporting substrate is arranged so that a first surface of the supporting substrate is perpendicular to a horizontal plane, a first warping amount of the supporting substrate is measured, a mask body is formed by depositing metal by electroforming in an area of ​​the base metal layer where no photoresist layer is formed, the supporting substrate is arranged so that the first surface of the supporting substrate is perpendicular to the horizontal plane, a second warping amount of the supporting substrate is measured, a shrinkage rate of the mask body is calculated based on a change in the warping amount calculated based on the first and second warping amounts and an internal stress of the supporting substrate calculated based on the change in the warping amount, and when the shrinkage rate of the mask body is less than a lower limit value of a predetermined range and greater than a first threshold value, or when the shrinkage rate of the mask body is greater than an upper limit value of the predetermined range and less than a second threshold value, the drawing coordinates of each predetermined pattern of a mask body to be manufactured next are changed in accordance with the shrinkage rate of the mask body. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1A This is a plan view of a vapor deposition mask according to one embodiment of the present invention.

[0012] Figure 1B This is a plan view of a vapor deposition mask according to one embodiment of the present invention.

[0013] Figure 1C This is a cross-sectional view of a vapor deposition mask according to one embodiment of the present invention.

[0014] Figure 2 This is a flowchart illustrating an outline of a process for manufacturing a vapor deposition mask according to one embodiment of the present invention.

[0015] Figure 3 This is a flowchart illustrating the process of adjusting the shrinkage rate of the mask body.

[0016] Figure 4AIt is a cross-sectional view showing a method for manufacturing a mask body.

[0017] Figure 4B It is a cross-sectional view showing a method for manufacturing a mask body.

[0018] Figure 4C It is a cross-sectional view showing a method for manufacturing a mask body.

[0019] Figure 5 These are simulation results of the warpage amount when a plating layer is formed on a SUS substrate.

[0020] Figure 6 These are simulation results of the warpage amount when a plating layer is formed on a glass substrate.

[0021] Figure 7 It is schematically shown on the supporting substrate Figure 5 The diagram shows areas 301 to 305.

[0022] Figure 8 is based on Figure 5 The obtained mask body shrinkage ratio is adjusted to an example of a photoresist layer having a predetermined pattern magnification.

[0023] Figure 9A It is a cross-sectional view showing a method of forming a mask frame on a mask body.

[0024] Figure 9B It is a cross-sectional view showing a method of forming a mask frame on a mask body.

[0025] Figure 9C It is a cross-sectional view showing a method of forming a mask frame on a mask body.

[0026] Figure 9D It is a cross-sectional view showing a method of forming a mask frame on a mask body.

[0027] Figure 9E It is a cross-sectional view showing a method of forming a mask frame on a mask body.

[0028] Description of Reference Numerals

[0029] 10, 10-1 to 10-3: evaporation mask, 110: mask body, 110-1: mask body, 110-2: mask body, 110a: first surface, 110b: second surface, 111: opening area, 112: non-opening area, 113: opening, 120: mask frame, 121: frame part, 122: barrier part, 130: connection part, 210: supporting substrate, 210a: first surface, 210b: second surface, 220: metal layer, 230: photoresist layer, 240: first plating layer, 250: protective layer, 270: second plating layer, 280: adhesive layer, 301 to 305: area, 311 to 315: area. 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 present invention and should not be construed as being limited to the description of the embodiments illustrated below.

[0031] To clarify the description, the drawings may sometimes schematically illustrate the width, thickness, shape, and other aspects of various components, as compared to actual embodiments. However, the examples shown in the drawings are merely examples and, unless otherwise specifically explained, do not limit the interpretation of the present invention. In this specification and the drawings, components identical to those previously described in the accompanying drawings may be denoted by the same reference numerals, and detailed descriptions thereof may be omitted as appropriate.

[0032] In this specification and claims, when expressing the manner in which another structure is arranged on a certain structure, when it is simply recorded as "on...", unless otherwise specified, it is defined as including the following two situations: a situation in which another structure is arranged directly above a certain structure in a manner of contacting the certain structure; and a situation in which another structure is arranged above a certain structure with other structures interposed therebetween.

[0033] (First embodiment)

[0034] Reference Figures 1A to 1C , the structure of the vapor deposition mask according to one embodiment of the present invention is described.

[0035] Figure 1A and Figure 1B 1 is a plan view of a vapor deposition mask 10 according to an embodiment of the present invention. Specifically, Figure 1A is a plan view of the evaporation mask 10 as viewed from the first surface 110a of the mask body 110. Figure 1B This is a plan view of the vapor deposition mask 10 as viewed from the second surface 110b opposite to the first surface 110a of the mask body 110. Figure 1C: 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 cross-sectional view of the vapor deposition mask 10 is shown along the line A1 - A2 .

[0036] 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 110a and a second surface 110b. Figure 1A and Figure 1B As shown, the mask frame 120 and the connection portion 130 are provided on the first surface 110a 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 a plan view from the first surface 110a of the mask body 110, the mask frame 120 and the connection portion 130 are exposed from the mask body 110. Figure 1B As shown, the mask frame 120 and the connecting portion 130 are not exposed from the mask body 110 when viewed from the second surface 110b of the mask body 110. In other words, it can be said that the mask frame 120 and the connecting portion 130 are covered by the mask body 110 when viewed from the second surface 110b of the mask body 110.

[0037] The mask body 110 includes an opening area 111 and a non-opening area 112. An opening 113 is provided in the opening area 111, which passes through the mask body 110 and corresponds to the vapor deposition pattern. 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 most cases, the opening 113 can be provided according to the vapor deposition pattern, so that 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.

[0038] The thickness of the mask body 110 is, for example, 1 μm to 10 μm. The mask body 110 is preferably formed of a material used in electroforming (or electroplating). The mask body 110 can be formed of, for example, nickel or a nickel alloy by electroforming.

[0039] When the evaporation process is performed using the evaporation mask 10, a substrate to be evaporated is set on the second surface 110b of the mask body 110. As the substrate to be evaporated, for example, a circuit substrate on which transistors and the like are formed is used. The evaporation mask 10 is fixed in the chamber of the evaporation device while the substrate to be evaporated is sandwiched in the middle and adsorbed by a magnet provided in the evaporation device. In the evaporation device, an evaporation source is provided on the first surface 110a side of the mask body 110. By heating the evaporation source, the organic material is heated and sublimated or evaporated. In such an evaporation process, the organic material is deposited only through the opening 113 of the mask body 110. Therefore, a pattern (evaporation pattern) corresponding to the opening 113 can be formed on the substrate to be evaporated. The opening 113 can be provided, for example, corresponding to the arrangement of pixels of the display device and can be arranged in a matrix. The opening 113 is arranged in the x-axis direction (also called the first direction) and the y-axis direction (also called the second direction). In Figure 1A In the figure, the center of the mask body 110 is taken as the reference point. When the reference point is set to coordinate O(0, 0), the four corners of the substrate are coordinates A(-x, y), coordinates B(-x, -y), coordinates C(x, -y), and coordinates D(x, y).

[0040] The mask frame 120 includes: a frame portion 121 located on the outer periphery of the vapor deposition mask 10; and a baffle portion 122 located on the inner side of the frame portion 121. The mask frame 120 is open on the inner side of the frame portion 121, and its opening is divided by the baffle portions 122 arranged in a grid shape. When the size of the mask frame 120 becomes larger, there is a situation where it is difficult to maintain the parallelism of the mask frame 120 at a prescribed 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 improved by the baffle portions 122, so that the parallelism of the mask frame 120 can be maintained at a prescribed 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 baffle portions 122 may not be provided.

[0041] The mask frame 120 may be formed by integrating the frame portion 121 and the barrier portion 122 , or by separately manufacturing the frame portion 121 and the barrier portion 122 and welding them together.

[0042] exist Figure 1A In the embodiment, the mask frame 120 is divided into 12 openings by the barrier portion 122, but the number of the openings is not limited thereto. The number of the openings can be appropriately determined according to the size of the substrate to be evaporated and the evaporation pattern. In addition, the configuration of the barrier portion 122 is not limited to a grid shape. In the case where the mask frame 120 is a rectangle with short sides and long sides, warping or distortion is more likely to occur on the long sides than on the short sides. Therefore, the barrier portion 122 is preferably provided in a manner connecting the opposite long sides. In addition, the configuration of the barrier portion 122 can also be a shape corresponding to the evaporation pattern.

[0043] The width of the frame 121 and the width of the stopper 122 can be appropriately determined according to the size of the deposition mask 10. In order to maximize the area of ​​the deposition pattern, the width of the stopper 122 is preferably smaller than that of the frame 121.

[0044] The thickness of the mask frame 120 is, for example, not less than 10 μm and not more than 2000 μm. Furthermore, the mask frame 120 is preferably formed of a material with a low thermal expansion coefficient. For example, the mask frame 120 can be formed of materials such as Invar alloy containing iron and nickel or Super Invar alloy containing iron, nickel, and cobalt.

[0045] The connection portion 130 can connect the mask body 110 and the mask frame 120. Figure 1C As shown, the mask body 110 is in direct contact with the mask frame 120, but the mask body 110 and the mask frame 120 are not 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.

[0046] The connection portion 130 may be provided on at least a portion of the side surface of the frame portion 121 or the barrier portion 122 of the mask frame 120. However, to increase the bonding strength between the mask body 110 and the mask frame 120, the connection portion 130 is preferably provided on at least half of the side surface of the frame portion 121 or the barrier portion 122, and more preferably, on the entire side surface of the frame portion 121 or the barrier portion 122. Furthermore, the connection portion 130 is preferably formed from a material used in electroforming. For example, the connection portion 130 is formed from a material such as nickel or a nickel alloy. The material of the connection portion 130 may be the same as or different from that of the mask body 110.

[0047] In the vapor deposition 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, stress in the mask body 110 or the mask frame 120 can be dispersed. Alternatively, the mask body 110 and the mask frame 120 may not be in direct contact, but a gap may be provided between them. In this case, stress in the mask body 110 or the mask frame 120 can also be dispersed.

[0048] During the mask body manufacturing process, when the finely patterned plating layer formed by electroplating is separated from the supporting substrate, the stress of the plating layer causes the plating layer to shrink. This can cause the opening area to deviate from the desired position, making it important to manage the shrinkage of the plating layer. However, without separating the plating layer from the supporting substrate, the shrinkage of the plating layer cannot be measured. Therefore, it takes several days to feed back the measured shrinkage of the plating layer to the fine pattern formation process or the plating layer formation process.

[0049] On the other hand, there are methods for measuring the shrinkage of the coating by forming a coating on a simulated support substrate and immediately peeling it off. In this case, the coating must be thick enough to prevent damage or deformation even when peeled off independently. However, the coating peeled off from the simulated support substrate is in a different state than the coating that constitutes the actual mask body, making it difficult to accurately evaluate the shrinkage.

[0050] In view of the above-mentioned problems, one object of one embodiment of the present invention is to provide a method for manufacturing a vapor deposition mask capable of improving the positional accuracy of an opening region.

[0051] In one embodiment of the present invention, the shrinkage rate of the mask body is checked online during the vapor deposition mask manufacturing process, and the inspection results are fed back to the preceding process. This allows the shrinkage rate of the mask body to be checked before the vapor deposition mask is completed, during the mask body formation stage, and the inspection results can be fed back earlier. Furthermore, the number of vapor deposition masks produced with high shrinkage rates and thus low positional accuracy of the opening areas can be reduced. In other words, the yield rate of usable vapor deposition masks can be increased.

[0052] Below, refer to Figures 2 to 9E A method for manufacturing a vapor deposition mask according to one embodiment of the present invention will be described.

[0053] Figure 2This is a flowchart for explaining an outline of the method for manufacturing a vapor deposition mask. In the present embodiment, the vapor deposition mask 10 is manufactured as follows. First, when the manufacturing process of the vapor deposition mask 10 starts, it is determined whether the end condition of the manufacturing process is met (step S401). If the end condition is met (step S401; "yes"), proceed; if the end condition is not met (step S401; "no"), proceed to the process of adjusting the shrinkage rate of the mask body (step S402). Next, it is determined whether the end condition of the loop is met (step S403). If the end condition of the loop is not met (step S403; "no"), proceed to the mask body forming process (step S404) and the mask frame forming process (step S405), return to step S403, and repeat the loop process. If the end condition of the loop is met (step S403; "yes"), return to step S401. In the following description, the order in which the vapor deposition mask 10 is manufactured is referred to as vapor deposition masks 10-1, 10-2, and 10-3. In cases where the manufacturing order is not distinguished, it is referred to as vapor deposition mask 10. The same applies to the components of the vapor deposition mask 10. The following describes each process shown in steps S401 to S405 in detail.

[0054] The termination condition in step S401 is, for example, whether a predetermined number of vapor deposition masks 10 have been manufactured, or whether an operation for terminating vapor deposition mask manufacturing has been performed. Here, the case of manufacturing the initial vapor deposition mask 10-1 is described. Therefore, if the termination condition is not met (step S401: "No"), the process proceeds to step S402.

[0055] Reference Figure 3 and Figures 4A to 4C , the process of adjusting the shrinkage rate of the mask body in step S402 is described.

[0056] Figure 3 This is a flowchart for explaining the process of adjusting the shrinkage rate of the mask body 110. First, a photoresist layer 230 ( ) having a predetermined pattern is formed on the support substrate 210 on which the Nth mask body is formed. Figure 3 Here, the case where N = 1 is described. The predetermined pattern refers to the opening pattern formed on the mask body. Figure 4AThe process of forming a metal layer 220 on a supporting substrate 210 and forming a photoresist layer 230 having a predetermined pattern on the metal layer 220 is shown. The supporting substrate 210 has a first surface 210a and a second surface 210b. The metal layer 220 is formed on the side of the first surface 210a. When viewed from above, the shape of the pattern of the photoresist layer 230 is, for example, roughly a quadrilateral. In this case, the arrangement of the patterns is set corresponding to the arrangement of the pixels of the display device and is arranged in a matrix. When manufacturing the initial vapor deposition mask 10-1, the arrangement of the patterns can be a pattern designed assuming that there is no influence of the shrinkage of the mask body, or a pattern designed from the beginning taking the influence of the shrinkage of the mask body into consideration.

[0057] The support substrate 210 can support 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. When the support substrate 210 expands or contracts due to the heat treatment, not only will the position of the photoresist layer 230 formed on the support substrate 210 be shifted, but there is also a situation where peeling occurs due to stress. Therefore, in order to stabilize the manufacturing process of the vapor deposition mask 10, the support substrate 210 is also more 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 alloy, Super Invar alloy, or stainless steel Invar alloy. In addition, a glass substrate can also be used as the support substrate 210.

[0058] The metal layer 220 serves 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 can be formed by sputtering, electroforming, or electroless plating.

[0059] The metal layer 220 is eventually separated and removed. Therefore, in order to facilitate separation of the metal layer 220 from the support substrate 210, a conductive layer may be provided on the metal layer 220. In this case, the metal layer 220 can be easily separated from the support substrate 210 by peeling off the conductive layer.

[0060] The deposition mask 10 may be manufactured using electroless plating instead of electroforming. When electroless plating is used, an insulating layer may be used instead of the metal layer 220 .

[0061] The photoresist layer 230 functions as a mask in the first electroforming step. The photoresist layer 230 is placed on the metal layer 220 to a predetermined thickness and developed into the desired shape. The photoresist can be a dry film resist that can be applied and processed, or a liquid coating resist. Furthermore, its photosensitivity can be either positive or negative. Below, an example using a negative photosensitive dry film will be described.

[0062] 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 can be formed by photolithography. Specifically, the pattern of the photoresist layer 230 can be formed by bringing a photomask into close contact (adhesion) with a dry film resist, irradiating the dry film with ultraviolet light to expose the dry film, and then dissolving and removing the unexposed portions.

[0063] Next, the warpage amount of the support substrate 210 on which the metal layer 220 and the photoresist layer 230 were formed was measured (refer to Figure 3 The warping of the support substrate 210 can be measured, for example, using a laser displacement sensor. When using a laser displacement sensor, the warping is measured by irradiating the support substrate 210 with laser light, and the reflected light is imaged on a CMOS sensor. The laser displacement sensor can be used to obtain data on the warping of the support substrate 210 in the XY plane. The warping amount obtained for each coordinate in the XY plane of the support substrate 210 is referred to as warping data. The number of warping points obtained can be appropriately set according to the area of ​​the support substrate 210.

[0064] When measuring the warpage of the support substrate 210, it is preferable to arrange the support substrate 210 so that the first surface 210a of the support substrate 210 is perpendicular to the horizontal plane. When the warpage of the support substrate 210 is measured with the first surface 210a of the support substrate 210 parallel to the horizontal plane, the warpage is reduced due to the weight of the support substrate 210, and thus the warpage cannot be accurately measured. Arranging the support substrate 210 so that the first surface 210a of the support substrate 210 is perpendicular to the horizontal plane can reduce the influence of the weight of the support substrate 210, and thus the warpage of the support substrate 210 can be accurately measured. If the influence of the weight of the support substrate 210 is small, the first surface 210a of the support substrate 210 can be tilted by ±20° relative to the direction perpendicular to the horizontal plane.

[0065] Next, the first plating layer 240 is formed on the support substrate 210 (see Figure 3 Step S413 shown). Figure 4B2 shows a process of forming the first plating layer 240 using the photoresist layer 230 as a mask. The first plating layer 240 is formed by electroforming (plating).

[0066] The plating solution used in electroforming is generally a solution obtained by dissolving one or more metal salts, organic electrolytes, acids such as phosphoric acid, and various electrolytes such as alkaline substances 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.

[0067] Metal salt can consider the metal to be separated out, alloy etc. and suitably select.As the metal of metal salt, 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 these, preferred Ni, Ag, Au, Cd, Co, Cr, Cu, Fe, Sn, Zn, and then particularly preferred Ni.In addition, these metals can be used alone respectively, or two or more combinations can be used.

[0068] Specific examples of the metal salt as the main component of the plating solution include, for example, nickel plating solutions, nickel sulfate, nickel sulfate, nickel chloride, nickel sulfamate, nickel chloride, etc. A plating solution in which each of these metal salts is used alone or a plating solution obtained by combining two or more of these metal salts can be used. A plating solution obtained by adding cobalt sulfamate to the above-mentioned nickel plating solution can also be used.

[0069] In the first electroforming step, the metal layer 220 and the photoresist layer 230 are placed in an electroforming tank containing the aforementioned plating solution under predetermined conditions. A metal plating layer is then 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 for the first plating layer 240 include nickel or a nickel alloy.

[0070] In this embodiment, nickel sulfamate is preferably used as the metal salt. By using nickel sulfamate as the metal salt to adjust the current density, the internal stress of the deposited nickel film can be adjusted. Alternatively, internal stress can be reduced by adding a stress reducer such as saccharin to the plating solution.

[0071] In addition, the internal stress of the nickel film can be adjusted by adding impurities to the nickel plating solution. By adding, as an organic chemical species, for example, a compound containing a sulfur atom in the molecule, to the nickel plating solution, compressive stress can be generated in the nickel film. In addition, as inorganic chemical species, for example, iron (II, III) ions, zinc ions and their hydroxides, chromate ions are added to the nickel plating solution, or as organic chemical species, 2-butyne-1,4-diol and 2-propyne-1-alcohol having a double bond in the molecule are added. Thus, tensile stress can be generated in the nickel film. When compressive stress is imparted to the nickel film, it is preferred to add impurities that can generate compressive stress in the nickel plating solution. In addition, in order to adjust the stress of the nickel film, in addition to adding impurities that can generate compressive stress, impurities that can generate tensile stress can also be added.

[0072] Next, the warpage of the support substrate 210 on which the first plating layer 240 was formed was measured (refer to Figure 3 The warpage measurement method in step S414 is similar to the warpage measurement method in step S412. Furthermore, the coordinates of the warpage measured in step S414 correspond to the coordinates of the warpage measured in step S412. Thus, data on the warpage in the XY plane is obtained. In the following description, the warpage measured before forming the first plating layer 240 is referred to as the first warpage, and the warpage measured after forming the first plating layer 240 is referred to as the second warpage.

[0073] Next, the warpage change δ is calculated based on the first warpage amount and the second warpage amount before and after the formation of the first plating layer 240. The warpage change δ is obtained by subtracting the first warpage amount from the second warpage amount for each coordinate. Next, based on the warpage change δ, the internal stress σ ( Figure 3 The internal stress σ of the first plating layer 240 can be calculated by the following formula (1).

[0074]

[0075] In formula (1), Es represents the Young's modulus of the support substrate 210, b represents the thickness of the support substrate 210, ν represents the Poisson's ratio of the support substrate 210, L represents the distance from the reference point of the support substrate 210, and d represents the thickness of the first coating layer 240. According to formula (1), the internal stress σ can be calculated for each coordinate in the XY plane. The internal stress σ calculated for each coordinate in the XY plane of the support substrate 210 is called internal stress data. The internal stress data of a single coordinate is in a one-to-one relationship with the warping amount of the coordinate, but it can also be calculated for all coordinates, or it can be based on the premise that the change in stress within the surface of the support substrate is constant, and the stress values ​​of other coordinates are obtained by approximation based on the relationship between the stress values ​​at several points sampled from the surface and the warping amount.

[0076] Next, the shrinkage rate ε of the first plating layer 240 is calculated based on the internal stress σ of the first plating layer 240 ( Figure 3 The shrinkage rate ε of the first plating layer 240 can be calculated by the following formula (2).

[0077]

[0078] By performing the above calculation on the data of the internal stress in the XY plane, the data of the shrinkage rate ε of the first plating layer 240 in the XY plane can be obtained.

[0079] Next, for the shrinkage rate ε of the first plating layer 240, it is determined whether the shrinkage rate is included in the prescribed range (step S417). The prescribed range of the allowable shrinkage rate ε varies depending on the material of the supporting substrate, such as Young's modulus, thickness, etc. For example, if the shrinkage rate ε is included in the prescribed range at all coordinates of the four corners of the supporting substrate 210, it is determined that the shrinkage rate ε is included in the prescribed range. For example, if the shrinkage rate ε is included in the prescribed range at prescribed coordinates other than the coordinates of the four corners of the supporting substrate 210, it is determined that the shrinkage rate ε is included in the prescribed range. In the case where it is determined that the shrinkage rate ε is included in the prescribed range (step S417; "yes"), the process proceeds to step S422 to remove the photoresist layer 230. Figure 4C 2 shows a step of stripping the photoresist layer 230 from the surface of the metal layer 220. The photoresist layer 230 is stripped using, for example, an amine-based stripping solution. This allows the first plating layer 240 having the opening region 111 and the non-opening region 112 to be formed.

[0080] The first plating layer 240 formed by electroforming may be polished before stripping the photoresist layer 230. Polishing the first plating layer 240 can planarize the surface of the first plating layer 240.

[0081] In addition, the first plating layer 240 corresponds to the mask main body 110 of the vapor deposition mask 10. Therefore, in the following description, the first plating layer 240 is referred to as the mask main body 110 for convenience.

[0082] Next, the mask frame forming process is performed (step S423). The mask frame forming process will be described in detail later. When the mask frame forming is completed, the manufacturing of the vapor deposition mask 10-1 is completed. The shrinkage adjustment process of the mask body 110 is completed, and the process proceeds to Figure 2 Step S403 is shown.

[0083] In the manufacturing process of the vapor deposition mask 10-1, if it is determined in step S417 that the shrinkage rate is not within the specified range (step S417; "No"), the process proceeds to step S418. For example, if the shrinkage rate ε is not within the specified range at any of the coordinates of the four corners of the support substrate 210, the shrinkage rate ε is determined to be not within the specified range. For example, even if the coordinates of the four corners of the support substrate 210 are within the specified range, if the shrinkage rate ε is not within the specified range at specified coordinates other than the four corners, the shrinkage rate ε is determined to be not within the specified range in step S417. In step S418, it is determined whether the shrinkage rate is above a first threshold value or below a second threshold value. Here, the first threshold value is a value less than the lower limit of the specified range, and the second threshold value is a value greater than the upper limit of the specified range. Similar to the specified range, the first and second threshold values ​​of the allowable shrinkage rate vary depending on the material of the support substrate, such as Young's modulus and thickness. Therefore, in a pattern of multiple display devices arranged within a surface, the opening pattern with the largest positional offset relative to a location where the positional offset is zero is offset by approximately ±1 / 2 of the pixel pitch relative to the original opening pattern, which is referred to as the first and second thresholds. Here, the relationship between shrinkage ∝ stress ∝ tension exists for the vapor deposition mask. When the tension is too high, the deformation of the vapor deposition mask increases, making pattern adjustment difficult. Furthermore, when the tension is too low, the mask body expands when the temperature rises during the vapor deposition process, causing the tension to reach zero and the mask to become loose.

[0084] When it is judged that the shrinkage rate is above the first threshold value or below the second threshold value (step S418; "No"), the drawing coordinates of the prescribed pattern of the N+1th photoresist layer are adjusted so that the calculated shrinkage rate is within the prescribed range of shrinkage rate (step S419). Here, N=1, so the drawing coordinates of the prescribed pattern of the photoresist layer in the subsequent manufacturing process of the vapor deposition mask 10-2 are adjusted. When the center of the support substrate 210 is used as the reference point, there is a tendency for the shrinkage rate to increase as the support substrate 210 moves toward the peripheral area. In this case, the magnification of the drawing of the prescribed pattern may be increased as the reference point (coordinate O) of the support substrate 210 moves toward the peripheral area. That is, the magnification of the drawing of the prescribed pattern may be linearly increased as the reference point of the support substrate 210 moves toward the peripheral area. By increasing the magnification of the drawing of the prescribed pattern, the drawing coordinates can be changed. In addition, the uniformity of the film thickness of the first coating 240 in the XY plane will affect the shrinkage rate of the XY plane. Therefore, in the XY plane, the magnification of the drawing of the prescribed pattern may be increased in the area with a relatively high shrinkage rate, or the magnification of the drawing of the prescribed pattern may be reduced in the area with a relatively low shrinkage rate. In addition, the supporting substrate 210 may be divided into a plurality of areas, and the magnification of the prescribed pattern may be set for each area. In addition, the reference point of the supporting substrate 210 may not be the center of the supporting substrate 210, but may be a point or area with the smallest shrinkage rate in the data of the shrinkage rate of the first coating 240 in the XY plane as the reference point. When the drawing coordinates of the prescribed pattern of the N+1th photoresist layer are adjusted, the process of step S402 is completed. Thereafter, in order to manufacture the N+1th mask body, the process of step S402 may be started from step S411.

[0085] If, in step S418, it is determined that the two-dimensional data for the shrinkage rate ε is less than the first threshold or exceeds the second threshold (step S418; "Yes"), the conditions of the first electroforming step are adjusted so that the calculated shrinkage rate ε is within the specified range (step S420). Here, N = 1, so the drawing of the specified pattern of the photoresist layer in the subsequent manufacturing step of the vapor deposition mask 10-2 is adjusted. Because the shrinkage rate of the mask body 110 is large, a stress reducer can be added to the plating solution in the first electroforming step, for example. Alternatively, nickel sulfamate can be used as a metal salt contained in the plating solution to adjust the current density. Furthermore, when a nickel plating solution is used as the plating solution, impurities can be added. As another method of adjusting stress, stress can be adjusted by raising or lowering the temperature of the plating solution. Furthermore, multiple stress adjustment methods can be used in combination to adjust stress. Alternatively, the processing time of the first electroforming step can be adjusted. When the conditions of the N+1th first electroforming step are adjusted, the process of step S402 ends. Then, in order to manufacture the N+1th (here, the second) mask main body, the process of step S402 may be started from step S411.

[0086] By performing steps S411 to S420, the shrinkage rate of the mask body produced (Nth) can be used as feedback to the predetermined patterning step and the first electroforming step for the photoresist layer of the next (N+1) mask body to be produced. This improves the accuracy of the opening position of the mask body 110 and stabilizes the manufacturing process.

[0087] In step S403, it is determined whether the end condition of the loop is satisfied. The end condition of the loop is whether a predetermined number of vapor deposition masks 10 have been manufactured. Here, the predetermined number of blocks in step S403 is less than the predetermined number of blocks in step S401. The predetermined number of blocks in step S403 is, for example, the number of blocks used to return to the process of adjusting the shrinkage rate of the mask body (step S402) after repeatedly performing the cycle of manufacturing the vapor deposition mask 10 (steps S404 and S405). By checking whether there is no abnormality in the shrinkage rate of the mask body 110 after manufacturing the predetermined number of vapor deposition masks 10, if there is an abnormality in the shrinkage rate of the mask body 110, the shrinkage rate can be adjusted early. Therefore, when the vapor deposition mask 10 reaches the specified number of blocks (step S403; "Yes"), in order to check whether the shrinkage rate of the mask body 110 is normal, return to step S402. When the vapor deposition mask 10 does not reach the specified number of blocks (step S403; "No"), repeat the process of steps S404 to S405.

[0088] Through the above-described steps, the vapor deposition mask 10 can be manufactured.

[0089] In a method for manufacturing a vapor deposition mask according to an embodiment of the present invention, instead of forming a coating on a simulated support substrate for measurement and peeling it off from the support substrate to measure the shrinkage rate, the shrinkage rate of the first coating 240 (mask body 110) used as a product is calculated without peeling the first coating 240 from the support substrate. As a result, it is possible to measure with the same thickness as the coating constituting the mask body 110. Therefore, compared with the case of measuring the shrinkage rate using a simulated substrate, the shrinkage rate can be evaluated more accurately. In addition, the conditions of the specified pattern or the conditions of the first electroforming process can be corrected based on the calculated shrinkage rate, so that feedback can be provided at an early stage.

[0090] In the method for manufacturing a vapor deposition mask according to one embodiment of the present invention, there are cases where the conditions for a predetermined pattern need to be changed, or where the electroforming conditions need to be changed. Changing the electroforming conditions each time the shrinkage rate of the mask body 110 is adjusted can take time to achieve the desired accuracy or for the plating solution to stabilize. This can reduce the productivity of the vapor deposition mask. Therefore, rather than changing the electroforming conditions each time the shrinkage rate of the mask body 110 is adjusted, the shrinkage rate of the mask body 110 is adjusted by changing the conditions for the predetermined pattern of the photoresist layer 230. Alternatively, in areas where the shrinkage rate of the first plating layer 240 is large, the drawing coordinates can be corrected so that the area of ​​the predetermined pattern becomes larger. This improves the positional accuracy of the opening area of ​​the first plating layer 240. Furthermore, if the shrinkage rate of the mask body 110 is large and correction by changing the predetermined pattern is difficult, changing the electroforming conditions can significantly shorten the time required to set the electroforming conditions.

[0091] After manufacturing the mask body 110, only mask bodies 110 that have achieved the desired shrinkage ratio can be sent to the mask frame formation process. By manufacturing the vapor deposition mask 10 in this manner, it is possible to determine whether a mask body should be sent to the mask frame formation process. Furthermore, the number of defective masks resulting from high shrinkage ratios of the mask body 110 and low positional accuracy of the opening area after mask frame formation can be reduced. This improves the final product yield.

[0092] Figure 5 The following shows the simulation results of the warpage amount when the mask body 110 is formed using a SUS substrate as a support substrate. Figure 6 The following is a simulation result showing the warpage amount when a glass substrate is used as a support substrate to form a mask body. The conditions used for the calculation are shown below.

[0093] The support substrate was a SUS substrate with a Young's modulus Es = 200 GPa, a thickness b = 1 mm, and dimensions = 1000 mm × 800 mm. Furthermore, the first plating layer formed on the support substrate was a Ni alloy with a thickness d = 5 μm and an internal stress σ = 40 MPa (tensile). Furthermore, with the center of the support substrate as coordinate O(0,0), the internal stress σ was calculated for every 10 mm in the X direction and every 10 mm in the Y direction.

[0094] The supporting substrate was a glass substrate with a Young's modulus Es = 77 GPa, a thickness b = 0.5 mm, and dimensions = 1000 mm × 800 mm. Furthermore, the first plating layer formed on the supporting substrate was a Ni alloy with a thickness d = 5 μm and an internal stress σ = 40 MPa (tensile). Furthermore, with the center of the supporting substrate as coordinate O(0,0), the internal stress σ was calculated for every 10 mm in the X direction and every 10 mm in the Y direction.

[0095] exist Figure 5 and Figure 6 In the figure, the XY plane of the support substrate is shown. Coordinate O(0,0) is the reference point of the support substrate. Figure 5 In the figure, region 301 is a region where the amount of warpage changes from 0 to 0.2, region 302 is a region where the amount of warpage changes from 0.2 to 0.4, region 303 is a region where the amount of warpage changes from 0.4 to 0.6, region 304 is a region where the amount of warpage changes from 0.6 to 0.8, and region 305 is a region where the amount of warpage changes from 0.8 to 1.0. Figure 6 In the graph, region 311 shows a warpage variation of 0 to 2, region 312 shows a warpage variation of 2 to 4, region 313 shows a warpage variation of 4 to 6, region 314 shows a warpage variation of 6 to 8, and region 315 shows a warpage variation of 8 to 10. Glass substrates have a lower Young's modulus than SUS substrates, and therefore exhibit a greater warpage variation.

[0096] like Figure 5 and Figure 6 As shown, the amount of change δ in the warp increases as the coordinates O (0, 0) of the substrate reference point are moved toward the four corners of the substrate, namely, coordinates A (-400, 500), B (-400, -500), C (400, -500), and D (400, 500). Specifically, the amount of warp increases as the coordinates O (0, 0) of the substrate reference point are moved toward the four corners, namely, coordinates A (-400, 500), B (-400, -500), C (400, -500), and D (400, 500).

[0097] Figure 7 It is schematically shown on the supporting substrate Figure 5The figure shows the area 301 to area 305. The change in the warping amount increases as it goes to the four corners of the support substrate. In addition, although not shown in the figure, the support substrate is also schematically shown. Figure 6 The distribution of the change in the warpage amount in the region 311 to the region 315 is Figure 7 Similarly, as the shrinkage rate of the mask body 110 increases, the area of ​​the opening region of the mask body 110 decreases, and the position (coordinates) of the opening region tends to shift. By measuring the shrinkage rate of the mask body 110, the trend of the area of ​​the opening region of the mask body 110 can be predicted. To correct the reduction in the area and the position (coordinates) of the opening region of the mask body 110, it is sufficient to adjust the predetermined pattern of the photoresist layer or adjust the conditions of the plating solution.

[0098] Figure 8 It is based on Figure 5 The obtained mask body shrinkage ratio is an example of the photoresist layers 331 to 335 in which the magnification of the predetermined pattern is adjusted. Figure 8 The photoresist layers 331 to 335 shown in the figure are partially represented; in reality, the photoresist layer is formed entirely on the support substrate. When changing the magnification of drawing a predetermined pattern, for example, the magnification can be set so that the magnification increases as the drawing goes from area 301 to area 305 when viewed from above. By changing the magnification, the area increases from photoresist layer 331 to photoresist layer 335. In addition, the drawing coordinates of each predetermined pattern can be changed so that the area of ​​each predetermined pattern in the peripheral area of ​​the support substrate is larger than the area of ​​each predetermined pattern near the reference point of the support substrate when viewed from above. As a result, when manufacturing the subsequent vapor deposition mask 10, a photoresist layer can be formed in which the area of ​​the predetermined pattern changes according to the amount of warping of the mask body 110, thereby improving the shape accuracy and positional accuracy of the opening area in the XY plane of the mask body 110.

[0099] Next, refer to Figures 9A to 9E The mask frame forming process will be described.

[0100] Figure 9A and Figure 9B This figure explains the process of attaching the mask frame. Figure 9A As shown, a protective layer 250 is formed on the opening region 111 of the mask body 110. Protective layer 250 prevents particles generated during the steps described below from entering the opening 113 of the opening region 111 and clogging the opening 113. Furthermore, protective layer 250 can function as a mask in the second electroforming step described below. The same material as that used for the photoresist layer 230 can be used for protective layer 250.

[0101] Next, if Figure 9B As shown, an adhesive layer 280 is provided on the non-opening region 112 of the mask body 110, and the mask frame 120 is bonded to the adhesive layer 280. The adhesive layer 280 will be removed in a later step and therefore does not need to be completely cured. Materials for the adhesive layer 280 include, for example, vinyl acetate resin, ethylene vinyl acetate resin, epoxy resin, cyanoacrylate resin, or acrylic resin.

[0102] Figure 9C This is a diagram illustrating the second electroforming process. Figure 9C 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. The second plating layer 270 is provided in a manner that fills the opening of the non-opening area 112, so that 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 side surface of the non-opening area 112 of the mask body 110 to the mask frame 120. That is, the second plating layer 270 corresponds to the connecting portion 130 of the vapor deposition mask 10. Therefore, below, for convenience, the second plating layer 270 is described as the connecting portion 130.

[0103] Figure 9D and Figure 9E This is a diagram illustrating the process of separating the support substrate. Figure 9D 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.

[0104] Then, if Figure 9E 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.

[0105] Through the above-described steps, the vapor deposition mask 10 in which the mask frame 120 and the connection portion 130 overlap with the mask main body 110 can be manufactured.

[0106] In addition, the order of the steps in the method for manufacturing the vapor deposition mask 10 is not limited to the above order. For example, Figure 9A The formation of the protective layer 250 shown can also be done by using Figure 9B The mask frame 120 shown is attached to the mask body. Figure 9D The peeling of the protective layer 250 shown can also be done in Figure 9E The support substrate 210 is shown separated.

[0107] In this embodiment, the method of forming the mask body 110 by electroplating is described, but one embodiment of the present invention is not limited to this. The mask body 110 can also be applied to films formed using other metal foil film-forming technologies, such as films formed by electroless plating or sputtering. The film used as the mask body 110 can be patterned by etching as appropriate.

[0108] As embodiments of the present invention, the various embodiments described above can be implemented in appropriate combinations as long as they do not contradict each other. In addition, embodiments obtained by those skilled in the art by appropriately adding, deleting, or changing the design of components, or adding, omitting, or changing the conditions based on the various embodiments are also included in the scope of the present invention as long as they include the gist of the present invention.

[0109] Even if it is other effects that are different from the effects brought about by the technical solutions of the above-mentioned embodiments, as long as it is an effect that can be known based on the records of this specification, or an effect that can be easily predicted by a person skilled in the art based on the records of this specification, it can of course be understood as an effect brought about by the present invention.

Claims

1. A method for manufacturing a vapor deposition mask, characterized in that: A photoresist layer having a predetermined pattern is formed on the support substrate via the base metal layer. The support substrate is arranged so that the first surface of the support substrate is perpendicular to a horizontal plane, and a first warping amount of the support substrate is measured. In the area of ​​the base metal layer where the photoresist layer is not formed, metal is deposited by electroforming to form a mask body. The support substrate is arranged so that the first surface of the support substrate is perpendicular to a horizontal plane, and a second warping amount of the support substrate is measured. calculating a shrinkage rate of the mask body based on a change in warpage calculated based on the first warpage amount and the second warpage amount and an internal stress of the support substrate calculated based on the change in warpage amount, When the shrinkage rate of the mask body is less than the lower limit of the specified range and is above the first threshold value, or when the shrinkage rate of the mask body is greater than the upper limit of the specified range and is below the second threshold value, the drawing coordinates of each of the specified patterns of the mask body to be manufactured next are changed according to the shrinkage rate of the mask body.

2. The method for manufacturing a vapor deposition mask according to claim 1, wherein: When the shrinkage rate of the mask body is less than the lower limit of the specified range and less than the first threshold, or when the shrinkage rate of the mask body is greater than the upper limit of the specified range and exceeds the second threshold, the electroforming conditions of the mask body to be manufactured next are changed.

3. The method for manufacturing a vapor deposition mask according to claim 1, wherein: When the shrinkage rate of the mask main body is within the predetermined range, the photoresist layer is peeled off and a mask frame is formed on the mask main body.

4. The method for manufacturing a vapor deposition mask according to claim 1, wherein: The drawing coordinates are changed so that the area of ​​the predetermined pattern increases radially from the reference point of the support substrate toward the peripheral region in a plan view.

5. The method for manufacturing a vapor deposition mask according to claim 1, wherein: The drawing coordinates are changed so that the area of ​​the predetermined pattern in the peripheral region of the support substrate is larger than the area of ​​the predetermined pattern near the reference point of the support substrate in a plan view.

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