Metal mask for vapor deposition and method for manufacturing metal mask for vapor deposition

Abstract

The vapor deposition metal mask of the present invention includes a vapor deposition metal mask substrate, which comprises: a surface having a first opening facing a vapor deposition source provided in a vapor deposition apparatus; a back surface being the opposite side of the surface and having a second opening smaller than the first opening; and a through hole having an inverted frustum shape extending into the first and second openings. The vapor deposition metal mask further comprises an antifouling layer containing a fluorine compound located on the surface and the inner wall surface defining the through hole. The halogen-containing halogen compound is not located on the back surface, the contact angle of the antifouling layer surface with water is 90° or more, and the surface roughness Sa of the surface of the vapor deposition metal mask substrate is 10 nm or more and 80 nm or less.

Description

Technical Field

[0001] This disclosure relates to metal masks for vapor deposition and methods for manufacturing metal masks for vapor deposition. Background Technology

[0002] High precision is required in display devices for small devices such as smartphones and head-mounted displays, as well as in OLED displays, which are gaining attention as flexible displays in the future. The main methods for forming pixels in OLED displays include vapor deposition and coating. Currently, from the perspective of component characteristics, vapor deposition is the primary method for forming pixels in OLED displays. Therefore, the light-emitting layer and other components of the pixel are typically formed by vapor deposition.

[0003] The evaporation metal mask used in the evaporation process for forming pixels has through holes. During the evaporation process, organic molecules used to form the desired pixel pattern on the substrate pass through these through holes. These organic molecules are light-emitting materials, etc., sublimated from the evaporation source. When the same evaporation metal mask is used repeatedly to pattern the pixels using evaporation, i.e., to form pixels, organic molecules accumulate on the surface of the evaporation metal mask facing the evaporation source, and also accumulate in the through holes, causing blockage and resulting in poor patterning. Therefore, washing is required to remove the organic molecules from the surface of the evaporation metal mask and from the patterned areas of the evaporation metal mask, i.e., from the through holes.

[0004] On the other hand, organic molecules fly towards the vapor deposition metal mask from multiple directions, adhering to the substrate used to form the pixel pattern. Therefore, when forming through-holes in the cross-section of the vapor deposition metal mask by etching only one side of the mask substrate, the angle between the face facing the vapor deposition source and the back side facing the substrate must be 45° or less. When forming through-holes by etching both the surface and the back side of the mask substrate, the angle between the face facing the vapor deposition source and the portion connecting the surface recess and the back side recess must be 45° or less. Due to this design limitation, the pixel density must be increased, meaning the thickness of the vapor deposition metal mask must be reduced through high precision.

[0005] However, with the thinning of metal masks for vapor deposition, they become prone to deformation due to washing. Metal masks for vapor deposition are generally washed using ultrasonic cleaning. Because of this deformation during washing, the surface of the substrate forming the metal mask was treated with omniphobic materials such as fluorine-containing substances (see, for example, Patent Document 1). Fluorine processing of the metal surface was also investigated in metal masks for printing plates (see, for example, Patent Document 2).

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2019-210496

[0009] Patent Document 2: Japanese Patent Application Publication No. 2006-205716 Summary of the Invention

[0010] The technical problem that the invention aims to solve

[0011] However, due to concerns that halogen-based materials such as fluorine may affect the light-emitting characteristics of organic EL devices and reduce their luminescence lifetime, the transfer of halogen-based materials from the metal mask used for evaporation to the substrate has become problematic.

[0012] Means for solving technical problems

[0013] A metal mask for vapor deposition used to solve the above-mentioned technical problems includes a metal mask substrate for vapor deposition, which includes: a surface having a first opening facing a vapor deposition source provided in a vapor deposition apparatus; a back surface being the opposite side of the aforementioned surface and having a second opening smaller than the first opening; and a through hole having an inverted frustum shape extending into the first opening and the second opening. The metal mask for vapor deposition further includes an antifouling layer containing a fluorine compound on the aforementioned surface and the inner wall surface of the through hole. The halogen-based compound containing halogen atoms is not located on the back surface, the contact angle of the antifouling layer surface with water is 90° or more, and the surface roughness Sa of the aforementioned surface of the metal mask substrate for vapor deposition is 10 nm or more and 80 nm or less.

[0014] A metal mask for vapor deposition used to solve the above-mentioned technical problems includes a metal mask substrate for vapor deposition, which includes: a surface having a first opening facing a vapor deposition source provided in a vapor deposition apparatus; a back surface being the opposite side of the aforementioned surface and having a second opening smaller than the first opening; and a through hole leading to the first opening and the second opening, comprising: a first hole portion including the first opening and having an inverted frustum shape; and a second hole portion including the second opening, having a frustum shape, and being smaller than the first hole portion. The metal mask for vapor deposition has an antifouling layer containing a fluorine compound on the aforementioned surface and the inner wall surface defining the first hole portion. Halogen compounds containing halogen atoms are not located on the aforementioned back surface or the inner wall surface defining the second hole portion. The contact angle of the antifouling layer surface with water is 90° or more, and the surface roughness Sa of the surface of the metal mask substrate for vapor deposition is 10 nm or more and 80 nm or less.

[0015] In the aforementioned metal mask for vapor deposition, the material forming the substrate of the aforementioned metal mask for vapor deposition can be an iron-nickel alloy or an iron-nickel-cobalt alloy.

[0016] In the aforementioned metal mask for vapor deposition, the thickness of the substrate of the metal mask for vapor deposition can be more than 1 μm and less than 100 μm.

[0017] A method for manufacturing a vapor deposition metal mask to solve the above-mentioned technical problems includes:

[0018] Prepare a metal mask substrate for vapor deposition, which has a surface for forming a first opening facing a vapor deposition source in the vapor deposition apparatus, and a back side located on the opposite side of the surface and for forming a second opening smaller than the first opening.

[0019] A resin layer is formed on the aforementioned back surface;

[0020] By wet etching the metal mask substrate for vapor deposition from the aforementioned surface, a through hole with an inverted frustum shape is formed, thereby forming the first opening on the aforementioned surface and the second opening on the aforementioned surface.

[0021] An antifouling layer containing a fluorine compound is formed on the aforementioned surface and on the inner wall surface defining the aforementioned through holes; and

[0022] After the antifouling layer is formed, the metal mask substrate for vapor deposition and the resin layer are exposed to an alkaline solution, thereby chemically removing the resin layer from the metal mask substrate for vapor deposition.

[0023] In the above-described method for manufacturing a metal mask for vapor deposition, the resin layer can be formed from polyimide.

[0024] A method for manufacturing a vapor deposition metal mask to solve the above-mentioned technical problems includes:

[0025] Prepare a metal mask substrate for vapor deposition, which has a surface for forming a first opening facing a vapor deposition source in the vapor deposition apparatus, and a back side located on the opposite side of the surface and for forming a second opening smaller than the first opening.

[0026] A second hole having the second opening and a frustoconical shape is formed on the back side by wet etching.

[0027] A resin layer is provided on the back surface in such a way that the second opening is covered;

[0028] By wet etching the metal mask substrate for vapor deposition from the surface described above, a first hole with an inverted frustum shape and the first opening are formed, thereby forming a through hole through the second hole and the first hole.

[0029] An antifouling layer containing a fluorine compound is formed on the aforementioned surface and on the inner wall surface defining the aforementioned first hole; and

[0030] After the antifouling layer is formed, the resin layer and the metal mask substrate for vapor deposition are exposed to an alkaline solution, thereby chemically removing the resin layer from the metal mask substrate for vapor deposition.

[0031] In the above-mentioned method for manufacturing a metal mask for vapor deposition, the resin layer can be formed from a photosensitive resin.

[0032] In the above-mentioned method for manufacturing a metal mask for vapor deposition, the resin layer can be formed from polyimide.

[0033] A method for manufacturing a vapor deposition metal mask to solve the above-mentioned technical problems includes:

[0034] Prepare a metal mask substrate for vapor deposition, which has a surface for forming a first opening facing a vapor deposition source in the vapor deposition apparatus, and a back side located on the opposite side of the surface and for forming a second opening smaller than the first opening.

[0035] A resin layer is formed on the aforementioned back surface;

[0036] By wet etching the metal mask substrate for vapor deposition from the aforementioned surface, a through hole with an inverted frustum shape is formed, thereby forming the first opening on the aforementioned surface and the second opening on the aforementioned back side.

[0037] An antifouling layer containing fluorine compounds is formed on the aforementioned surface and on the inner wall surface defining the aforementioned through holes;

[0038] After the antifouling layer is formed, the metal mask substrate for vapor deposition and the resin layer are exposed to ultraviolet light, thereby reducing the adhesion of the resin layer to the metal mask substrate for vapor deposition; and

[0039] The resin layer with reduced adhesion is peeled off from the metal mask substrate for vapor deposition.

[0040] In the above-mentioned method for manufacturing a metal mask for vapor deposition, the resin layer can be formed by an ultraviolet-curable adhesive.

[0041] Invention Effects

[0042] According to the present invention, the vapor deposition material deposited on the vapor deposition metal mask can be easily removed, and deformation of the vapor deposition metal mask caused by ultrasonic cleaning can be suppressed. Attached Figure Description

[0043] Figure 1This is a top view showing the structure of a mask device according to one embodiment.

[0044] Figure 2 This is a cross-sectional view showing the structure of a first example of a metal mask for vapor deposition according to the same embodiment.

[0045] Figure 3 This is a cross-sectional view showing the structure of a second example of a metal mask for vapor deposition according to the same embodiment.

[0046] Figure 4 This is a cross-sectional view that partially shows the joint structure between the edge of the metal mask used for vapor deposition and the mask frame.

[0047] Figure 5A A top view showing the relationship between the number of mask frame holes in a metal mask sheet for vapor deposition and the number of metal masks for vapor deposition.

[0048] Figure 5B To indicate Figure 5A The diagram shows a cross-sectional view of the structure of the metal mask sheet used for vapor deposition.

[0049] Figure 6A This is a process diagram illustrating one step of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0050] Figure 6B This is a process diagram illustrating one step of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0051] Figure 6C This is a process diagram illustrating one step of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0052] Figure 6D This is a process diagram illustrating one step of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0053] Figure 6E This is a process diagram illustrating one step of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0054] Figure 6F This is a process diagram illustrating one step of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0055] Figure 6G This is a process diagram illustrating one step of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0056] Figure 7A This is a process diagram illustrating one step of a method for manufacturing a vapor-deposited metal mask according to the same embodiment.

[0057] Figure 7B This is a process diagram illustrating one step of a method for manufacturing a vapor-deposited metal mask according to the same embodiment.

[0058] Figure 7C This is a process diagram illustrating one step of a method for manufacturing a vapor-deposited metal mask according to the same embodiment.

[0059] Figure 8A This is a process diagram illustrating one step of a second example of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0060] Figure 8B This is a process diagram illustrating one step of a second example of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0061] Figure 8C This is a process diagram illustrating one step of a second example of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0062] Figure 8D This is a process diagram illustrating one step of a second example of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0063] Figure 8E This is a process diagram illustrating one step of a second example of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0064] Figure 8F This is a process diagram illustrating one step of a second example of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0065] Figure 8G This is a process diagram illustrating one step of a second example of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0066] Figure 8H This is a process diagram illustrating one step of a second example of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0067] Figure 8I This is a process diagram illustrating one step of a second example of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0068] Figure 8J This is a process diagram illustrating one step of a second example of a method for manufacturing a metal mask for vapor deposition according to the same embodiment.

[0069] Figure 8K This is a process diagram illustrating one step of a second example of a method for manufacturing a metal mask for vapor deposition according to the same embodiment. Detailed Implementation

[0070] The following description, with reference to the accompanying drawings, illustrates a metal mask for vapor deposition and a method for manufacturing such a mask. The drawings are schematic diagrams, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc., differ from actual measurements. Furthermore, the embodiments shown below are examples of configurations used to embody the technical concept of the present invention; the technical concept of the present invention is not intended to limit the materials, shapes, and structures of the constituent components to the following. The technical concept of this disclosure can be modified in various ways within the scope of the claims as defined in the claims.

[0071] [Metal mask for vapor deposition]

[0072] like Figure 1 As shown, the mask assembly 10 includes a main frame 20 and a plurality of metal mask sheets 30 for vapor deposition. The main frame 20 has a frame shape that supports the plurality of metal mask sheets 30 for vapor deposition. The main frame 20 is mounted on a vapor deposition apparatus for performing vapor deposition. The main frame 20 defines a main frame aperture 21. A portion of each metal mask sheet 30 for vapor deposition is located within the main frame aperture 21.

[0073] The metal mask sheet 30 for vapor deposition includes a mask frame 31 and a metal mask 32 for vapor deposition. The mask frame 31 has an elongated shape for supporting the metal mask 32 for vapor deposition. The mask frame 31 is mounted on the main frame 20. The mask frame 31 has the same number of mask frame holes 33 as the number of metal masks 32 for vapor deposition. Each mask frame hole 33 is a hole that passes through approximately the entire area of ​​one metal mask 32 for vapor deposition in the mask frame 31. The mask frame 31 has higher rigidity than the metal mask 32 for vapor deposition and has a frame shape surrounding the mask frame holes 33. The portion of the mask frame 31 that divides the mask frame holes 33 is the inner edge portion 31E (see reference). Figure 4 The metal mask 32 for vapor deposition is fixed to the inner edge 31E by welding and bonding.

[0074] Reference Figure 2 as well as Figure 3 The metal mask 32 for vapor deposition is described in more detail below. Furthermore, the following... Figure 2 The metal mask 32 for vapor deposition shown is... Figure 3 The common aspects of the metal masks 32 used for vapor deposition shown will be explained. Next, the aspects specific to each metal mask 32 used for vapor deposition will be explained.

[0075] like Figure 2 as well as Figure 3As shown, the metal mask 32 for vapor deposition in the metal mask sheet 30 includes a metal mask substrate 32S and an anti-fouling layer 32AF. The metal mask 32 has a surface 32a (hereinafter referred to as surface 32a) of the metal mask substrate and a back surface 32b (hereinafter referred to as back surface 32b), which is also the side opposite to surface 32a. At least one of surface 32a and back surface 32b is an object surface used for positioning the resist layer. The object surface is the surface on which the resist mask is formed during the formation of the metal mask 32 for vapor deposition.

[0076] The metal mask substrate 32S for vapor deposition can be formed from a single metal sheet or from multiple layers of metal sheets. The metal mask substrate 32S for vapor deposition is made of metal. The material forming the metal mask substrate 32S for vapor deposition can be, for example, an iron-nickel alloy or an iron-nickel-cobalt alloy. An iron-nickel alloy is an alloy with iron and nickel as the main components, and for example, contains at least 30% by mass of nickel and the remainder of iron. Among iron-nickel alloys, an alloy containing 36% by mass of nickel, i.e., an Invar alloy, is preferred as a material for forming the metal mask 32S for vapor deposition. In the Invar alloy, the remainder relative to the 36% by mass of nickel sometimes contains additives other than iron as the main component. Examples of additives include chromium, manganese, carbon, and cobalt. The amount of additives contained in the iron-nickel alloy is at most 1% by mass or less.

[0077] Among iron-nickel-cobalt alloys, those containing 32% by mass of nickel and 4% by mass or more but less than 5% by mass of cobalt, namely super-Invar alloys, are preferred as materials for forming the metal mask substrate 32S for vapor deposition. In super-Invar alloys, the remainder relative to the 32% by mass of nickel and 4% by mass or more but less than 5% by mass of cobalt sometimes contains additives other than iron, which is the main component. Examples of additives include chromium, manganese, and carbon. The amount of additives contained in the iron-nickel-cobalt alloy is at most 0.5% by mass or less.

[0078] The coefficient of thermal expansion of iron-nickel-cobalt alloys is lower than that of iron-nickel alloys. The alloy used to form the 32S metal mask substrate for vapor deposition is preferably an iron-nickel alloy, but it can also be an iron-nickel-cobalt alloy.

[0079] The surface 32a of the metal mask substrate 32S for vapor deposition satisfies the following [condition 1].

[0080] [Condition 1] The surface roughness Sa satisfies the following formula.

[0081] 10nm≤Sa≤80nm

[0082] Surface roughness Sa is a value measured based on ISO 25178. When surface roughness Sa is less than 10 nm, deposits of the vapor-deposited material can be removed by ultrasonic cleaning. However, during vapor deposition, the vapor-deposited material deposited on the metal mask peels off and falls to the vapor deposition source, generating sparks. Due to these sparks, the vapor-deposited material cannot be deposited uniformly. That is, with a surface roughness Sa of 10 nm or more, deposits of the vapor-deposited material can be removed by ultrasonic cleaning. Furthermore, with a surface roughness Sa of 10 nm or more, the peeling off of the vapor-deposited material deposited on the vapor deposition metal mask 32 during vapor deposition, and the subsequent sparking caused by the peeled-off vapor-deposited material falling to the vapor deposition source, can be suppressed.

[0083] When the surface roughness Sa exceeds 80 nm, even if the metal surface is fluorinated, the deposits of the vapor-deposited material on the metal mask substrate cannot be removed by ultrasonic treatment due to the physical anchoring effect between the metal surface and the deposits of the vapor-deposited material. In other words, by ensuring the surface roughness Sa is below 80 nm, the anchoring effect of the surface of the metal mask 32 on the deposits of the vapor-deposited material can be suppressed, thereby allowing the removal of deposits from the fluorinated surface of the metal mask 32 by ultrasonic treatment.

[0084] The antifouling layer 32AF contains a fluorine compound. The antifouling layer 32AF has a surface that is opposite to the surface that contacts the metal mask substrate 32S for vapor deposition. The surface of the antifouling layer 32AF satisfies the following [condition 2].

[0085] [Condition 2] The surface of the antifouling layer 32AF has a contact angle of 90° or more with water.

[0086] Since the contact angle of the antifouling layer 32AF is greater than 90°, the adhesion of the vapor-deposited material to the antifouling layer 32AF is weakened, thereby allowing the deposits on the antifouling layer 32AF to be removed by ultrasonic treatment.

[0087] The material forming the antifouling layer 32AF can be appropriately selected as a material containing fluorine compounds that is insoluble in solvents and whose adhering residues are easily removed. For example, antifouling materials conventionally known in the fields of "antireflective films" and "hydrophobic sheets" can be used as the antifouling layer 32AF of the present invention.

[0088] The manufacturing method of the metal mask substrate 32S for vapor deposition uses any one of (A) electrolysis, (B) rolling and grinding, (C) electrolysis and grinding, and (D) rolling only.

[0089] When the substrate 32S for vapor deposition is an Invar alloy sheet, the coefficient of thermal expansion of the substrate 32S is 1.2 × 10⁻⁶. -6The temperature is approximately ℃. Furthermore, if the metal mask substrate 32S for vapor deposition is a super Invar alloy sheet, then the coefficient of thermal expansion of the metal mask substrate 32S for vapor deposition is 0.5 × 10⁻⁶. -6 / ℃. Based on the vapor deposition metal mask substrate 32S having this coefficient of thermal expansion, the degree of thermal expansion of the vapor deposition metal mask 32 and the degree of thermal expansion of the glass substrate are integrated. Therefore, in vapor deposition using the mask apparatus 10, a glass substrate is preferably used as an example of the object to be vapor deposited.

[0090] The metal mask substrate 32S for vapor deposition, as described above, has a surface 32a and a back surface 32b. Surface 32a is the surface within the vapor deposition apparatus that faces the vapor deposition source. Back surface 32b is the surface within the vapor deposition apparatus that is used to contact or approach the vapor deposition object, such as a glass substrate. Furthermore, back surface 32b is an example of a contact or approach surface, while surface 32a is an example of a non-contact surface.

[0091] The thickness of the metal mask substrate 32S for vapor deposition is 1 μm or more and 100 μm or less, preferably 1 μm or more and 40 μm or less. If the thickness of the metal mask substrate 32S for vapor deposition is 40 μm or less, the depth of the holes formed in the metal mask substrate 32S for vapor deposition can be 40 μm or less. When a higher resolution is required for the metal mask 32 for vapor deposition, the thickness of the metal mask substrate 32S for vapor deposition is, for example, 1 μm or more and 15 μm or less. Wherein, if the thickness of the metal mask substrate 32S for vapor deposition is 5 μm or less, the depth of the metal mask hole 32H (hereinafter referred to as mask hole 32H), which is one example of a through hole formed in the metal mask substrate 32S for vapor deposition, can be 5 μm or less. If the metal mask substrate 32S for vapor deposition is so thin, when observing the vapor deposition object from the vapor deposition particles flying toward the metal mask 32 for vapor deposition, the part that is covered by the metal mask 32 for vapor deposition can be reduced, that is, the shadowing effect can be suppressed.

[0092] Furthermore, if the thickness of the metal mask substrate 32S for vapor deposition is 3 μm or more and 5 μm or less, the metal mask substrate 32S for vapor deposition can have multiple mask holes 32H that are separated from each other when viewed from above facing the surface 32a, and can be used to manufacture high-resolution display devices with a resolution of 700 ppi or more and 1000 ppi or less. Alternatively, if the thickness of the metal mask substrate 32S for vapor deposition is 10 μm or more and 15 μm or less, the metal mask substrate 32S for vapor deposition can have multiple mask holes 32H that are separated from each other when viewed from above facing the surface 32a, and can be used to manufacture low-resolution display devices with a resolution of 300 ppi or more and 400 ppi or less.

[0093] Figure 2In the example shown, the vapor deposition metal mask 32 has a plurality of mask holes 32H penetrating the vapor deposition metal mask substrate 32S. The side of the hole dividing the mask holes 32H has an inverted frustum shape that extends outward from the mask hole 32H in a cross section along the thickness direction of the vapor deposition metal mask substrate 32S.

[0094] Surface 32a includes a surface opening H1 that serves as an opening for a mask aperture 32H. Back surface 32b includes a back surface opening H2 that serves as an opening for a mask aperture 32H. Surface opening H1 is an example of a first opening, and back surface opening H2 is an example of a second opening. Viewed from above facing surface 32a, surface opening H1 is larger than back surface opening H2. Each mask aperture 32H is a pathway for vapor-deposited particles sublimated from the vapor deposition source. Vapor-deposited particles sublimated from the vapor deposition source travel from surface opening H1 to back surface opening H2 within the mask aperture 32H. Because surface opening H1 is larger than back surface opening H2 within the mask aperture 32H, the shading effect on vapor-deposited particles entering from surface opening H1 can be suppressed.

[0095] In surface 32a, each surface opening H1 is separate from other surface openings H1. In other words, in surface 32a, each surface opening H1 is not connected to other surface openings H1. Therefore, it is possible to suppress the thickness of the portion of the metal mask 32 for vapor deposition located between surface openings H1 when viewed from above facing surface 32a from being thinner than the thickness of the portion of the metal mask 32 for vapor deposition where mask holes 32H are not formed. As a result, the decrease in mechanical strength of the metal mask 32 for vapor deposition can be suppressed. Conversely, in surface 32a, when one surface opening H1 is connected to other surface openings H1, the thickness at the portion where two surface openings H1 are connected becomes thinner than the portion of the metal mask 32 for vapor deposition where mask holes 32H are not formed. As a result, the mechanical strength of the metal mask 32 for vapor deposition decreases compared to the case where each surface opening H1 is far from other surface openings H1.

[0096] Furthermore, if the thickness of the metal mask 32 for evaporation is 3 μm or more and 5 μm or less, multiple mask holes 32H capable of manufacturing the aforementioned high-resolution display device can be formed simply by wet etching the metal mask substrate 32S for evaporation from the surface 32a. Alternatively, if the thickness of the metal mask 32 for evaporation is 10 μm or more and 15 μm or less, multiple mask holes 32H capable of manufacturing the aforementioned low-resolution display device can be formed simply by wet etching the metal mask substrate 32S for evaporation from the surface 32. Thus, in either case, wet etching of the metal mask substrate 32S for evaporation from the back surface 32b is unnecessary.

[0097] Figure 2 The vapor deposition metal mask 32 shown has a vapor deposition metal mask substrate 32S that satisfies the following [condition 3].

[0098] [Condition 3] Halogen compounds containing halogen atoms are not located on the back side 32b.

[0099] Figure 2 In the metal mask 32 for vapor deposition shown, the anti-fouling layer 32AF is located on the surface 32a and the inner wall surface of the mask hole 32H, which is defined as a through hole, but not on the back surface 32b. Therefore, halogen compounds containing halogen atoms are not located on the back surface 32b.

[0100] Furthermore, the halogen atom can be at least one of fluorine, chlorine, bromine, and iodine atoms. That is, the halogen compound can be a compound containing at least one of fluorine, chlorine, bromine, and iodine atoms. The halogen compound can be a fluorine-containing fluorine compound. For example, a fluorine compound can be a material used to form the antifouling layer 32AF.

[0101] In contrast, in order to form a metal mask 32 for manufacturing display devices with various resolutions using a thicker metal mask substrate 32S for vapor deposition, it is necessary to perform wet etching on the metal mask substrate 32S from the surface 32a and the back surface 32b respectively.

[0102] At this time, as Figure 3 As shown, the mask hole 32H includes a surface recess 32LH and a back recess 32SH. The surface recess 32LH is an example of a first hole, and the back recess 32SH is an example of a second hole. The surface recess 32LH is an inverted frustum-shaped recess formed by wet etching of the metal mask substrate 32S for vapor deposition from the surface 32a. The back recess 32SH is a frustum-shaped recess formed by wet etching of the metal mask substrate 32S for vapor deposition from the back surface 32b. The surface recess 32LH is connected to the back recess 32SH at a position closer to the back opening H2 than the center of the metal mask 32 in the thickness direction. In the mask hole 32H, the portion where the surface recess 32LH is connected to the back recess 32SH is a connecting portion. That is, the mask hole 32H includes the surface recess 32LH, the connecting portion, and the back recess 32SH, thereby forming a mask hole 32H as a through hole.

[0103] The area of ​​the mask hole 32H along the direction parallel to surface 32a is minimized at the connection portion. In this mask hole 32H, the distance between the back opening H2 and the connection portion is the step height SH. The larger the step height SH is, the greater the aforementioned shading effect becomes.

[0104] therefore, Figure 3 In the metal mask 32 for vapor deposition shown, from the viewpoint of suppressing the shadowing effect, the step height SH is preferably 2 μm or less, more preferably 1 μm or less, and even more preferably 0.5 μm or less.

[0105] In contrast, the above Figure 2 In the metal mask 32 shown for vapor deposition, the step height SH is 0. At this time, only by… Figure 2 The surface recess 32LH in the mask hole 32H shown forms a mask hole 32H as a through hole.

[0106] also, Figure 3 In the above view facing surface 32a, although the multiple mask holes 32H are separated from each other, during wet etching from surface 32a, adjacent surface recesses 32LH affect each other. In other words, adjacent surface recesses 32LH become connected to each other, resulting in a situation where adjacent mask holes 32H are not separated from each other. In this case, the strength of the vapor deposition metal mask 32 is lower than that of the vapor deposition metal mask 32 formed using a vapor deposition metal mask substrate 32S of the same thickness, where adjacent mask holes 32H are separated from each other.

[0107] Figure 3 The metal mask substrate 32S for vapor deposition shown in the vapor deposition metal mask 32 satisfies the following [condition 4].

[0108] [Condition 4] Halogen compounds are not located on the back surface 32b or on the inner wall surface of the recessed back surface 32SH.

[0109] Figure 3 In the metal mask 32 for vapor deposition shown, the anti-fouling layer 32AF is located on the surface 32a and the inner wall surface of the defined surface recess 32LH, but not on the back surface 32b and the inner wall surface of the defined back surface recess 32SH. Therefore, halogen compounds are not located on the back surface 32b and the inner wall surface of the defined back surface recess 32SH.

[0110] [Joint structure of metal masks for vapor deposition]

[0111] Reference Figure 4 This describes the cross-sectional structure of the joint structure between the metal mask 32 and the mask frame 31 used for vapor deposition. Furthermore, Figure 4 For ease of illustration, the anti-fouling layer 32AF of the metal mask 32 used for vapor deposition is omitted from the illustration.

[0112] like Figure 4 As shown, in the metal mask substrate 32S for vapor deposition, the portion including the edge of the metal mask substrate 32S for vapor deposition is the outer peripheral edge portion 32E. The area in the outer peripheral edge portion 32E of the metal mask substrate 32S where the mask holes 32H are not formed is continuous along the edge of the metal mask substrate 32S. The portion of surface 32a included in the outer peripheral edge portion 32E is joined to the mask frame 31.

[0113] The mask frame 31 includes an inner edge portion 31E, a frame back surface 31b, and a frame surface 31a. The inner edge portion 31E divides the mask frame holes 33. The frame back surface 31b faces the metal mask substrate 32S for vapor deposition. The frame surface 31a is the surface opposite to the frame back surface 31b. The inner edge portion 31E includes a portion of the frame back surface 31b and a portion of the frame surface 31a. The thickness T31 of the mask frame 31, i.e., the distance between the frame back surface 31b and the frame surface 31a, is greater than the thickness T32 of the metal mask substrate 32S for vapor deposition. Therefore, the mask frame 31 has higher rigidity than the metal mask substrate 32S for vapor deposition. In particular, the mask frame 31 has high rigidity in the event that the inner edge portion 31E sags due to its own weight or that the inner edge portion 31E is displaced towards the metal mask 32S for vapor deposition.

[0114] The forming material of the mask frame 31 is preferably an iron-nickel alloy or an iron-nickel-cobalt alloy. More preferably, the forming material of the mask frame 31 is the same alloy used as the main component of the metal mask substrate 32S for vapor deposition in the iron-nickel alloy or iron-nickel-cobalt alloy. That is, the forming material of the mask frame 31 is preferably an Invar alloy or a super Invar alloy. When the thickness T31 of the mask frame 31 is less than 20 μm, it is preferably more than twice the thickness T32 of the metal mask substrate 32S for vapor deposition.

[0115] The joint 31BN, formed by joining surface 32a to the back surface 31b of the mask frame 31, is located on the portion of the back surface 31b contained within the inner edge portion 31E. The joint 31BN exists continuously or intermittently throughout approximately the entire circumference of the inner edge portion 31E. The joint 31BN may be a weld mark formed by welding the back surface 31b of the frame to surface 32a. Alternatively, the joint 31BN may be a bonding layer that joins the back surface 31b of the frame to surface 32a, a separate layer from both the mask frame 31 and the metal mask 32 for vapor deposition.

[0116] Furthermore, when the mask frame 31 is joined to the main frame 20, the main frame 20 applies a tensile stress to the mask frame 31 towards the outside of the mask frame 31. At this time, the mask frame 31 is joined to the main frame 20 in such a way that none of its ends in the extending direction of the mask frame 31 are exposed to the outside of the main frame 20.

[0117] [Number of metal masks used for vapor deposition]

[0118] Reference Figure 5A as well as Figure 5B This explains the relationship between the number of mask frame holes 33 in the metal mask sheet 30 for vapor deposition and the number of metal masks 32 for vapor deposition. Furthermore, Figure 5A as well as Figure 5BFor ease of illustration, the illustration of antifouling layer 32AF is omitted.

[0119] like Figure 5A As shown, the mask frame 31, as a plurality of mask frame holes 33, has, for example, three mask frame holes 33A, 33B, and 33C. Figure 5B As shown, the vapor deposition metal mask sheet 30 has one vapor deposition metal mask 32 corresponding to each of the mask frame holes 33A, 33B, and 33C. More specifically, the inner edge portion 31E dividing the first mask frame hole 33A is engaged with the first vapor deposition metal mask 32A. The inner edge portion 31E dividing the second mask frame hole 33B is engaged with the second vapor deposition metal mask 32B. The inner edge portion 31E dividing the third mask frame hole 33C is engaged with the third vapor deposition metal mask 32C.

[0120] Since the metal mask sheet 30 for vapor deposition is repeatedly used for multiple vapor deposition objects, high precision is required in the position and structure of each of the multiple mask holes 32H provided by the metal mask sheet 30 for vapor deposition. Therefore, when three metal masks 32 for vapor deposition are used to cover the number of mask frame holes 33A, 33B, and 33C required for one mask frame 31, the following advantages are available: Compared to when the metal mask sheet 30 for vapor deposition has one metal mask 32 covering all mask frame holes 33A, 33B, and 33C, or when the metal mask sheet 30 for vapor deposition is composed solely of metal masks 32 (i.e., the mask frame 31 and the metal mask 32 are integrated), the following advantages are available: When a portion of one metal mask 32 for vapor deposition is deformed, the size of the new metal mask 32 to be replaced with the previous one can be reduced. In addition, it can also reduce the consumption of various materials required in the manufacturing and repair of the metal mask sheet 30 for vapor deposition.

[0121] Furthermore, inspections related to the structure of the mask aperture 32H are preferably performed while the vapor deposition metal mask 32 is engaged with the mask frame 31. Therefore, the joint 31BN is preferably configured to allow replacement of a deformed vapor deposition metal mask 32 with a new one. This allows for the use of one mask frame 31 for multiple vapor deposition metal mask substrates 32S, and for the use of one mask frame 31 to inspect different vapor deposition metal masks 32. Moreover, the thinner the thickness of the vapor deposition metal mask substrate 32S constituting the vapor deposition metal mask 32, and the smaller the size of the mask aperture 32H, the lower the yield of the vapor deposition metal mask 32 is. Therefore, a configuration of a vapor deposition metal mask 32 having one aperture 33 for each of multiple mask frames is preferred for vapor deposition metal mask sheets 30 requiring high precision.

[0122] Furthermore, in the mask frame 31, multiple mask frame holes 33 constitute a mask hole array. The mask frame 31 is not limited to having a single mask hole array, but can also be configured to have multiple mask hole arrays. Thus, the metal mask sheet 30 for vapor deposition can also be configured to be composed of multiple arrays of metal masks 32 for vapor deposition arranged together.

[0123] [Manufacturing method of metal mask for vapor deposition]

[0124] Referring to Figures 6 to 8, the manufacturing method of the metal mask 32 for vapor deposition will be described.

[0125] In addition, manufacturing and use Figure 2 The method and manufacturing process of the metal mask 32 for vapor deposition are described. Figure 3 The method for using the vapor deposition metal mask 32 described herein is essentially the same except for the wet etching process on the vapor deposition metal mask substrate 32S. That is, using... Figure 2 The vapor deposition metal mask 32 described herein is manufactured by a single-sided etching method, which processes only one side, i.e., one side, of the vapor deposition metal mask substrate 32S. Figure 3 The metal mask 32 for vapor deposition described herein is manufactured by a double-sided etching method that processes the metal mask substrate 32S for vapor deposition from both sides.

[0126] Since the size of the surface opening H1 and the back opening H2 can be controlled, double-sided etching is preferred in the manufacture of the metal mask 32 for vapor deposition. On the other hand, when the thickness of the metal mask substrate 32S for vapor deposition is 15 μm or less, due to its thinness, single-sided etching can be used instead of double-sided etching. The following description mainly refers to… Figure 2 The manufacturing method of the metal mask substrate 32S for vapor deposition, as previously explained. Regarding the reference... Figure 3 The manufacturing method of the metal mask 32 for vapor deposition, as previously explained, will be combined with... Figure 2 The repeated description of the manufacturing method of the vapor deposition metal mask 32 shown is omitted. Furthermore, as one example of the manufacturing method of the vapor deposition metal mask 32, a manufacturing method using Invar alloy as the material for forming the vapor deposition metal mask substrate 32S is shown.

[0127] As shown in Figure 6, the manufacturing method of the metal mask 32 for vapor deposition first prepares the metal mask substrate 32S for vapor deposition (refer to Figure 6) using the above-mentioned rolling and grinding processes. Figure 6AAt this point, in order to achieve the desired thickness of the metal mask substrate 32S for vapor deposition, a relatively thick Invar alloy sheet is prepared, and then the Invar alloy sheet is thinned by etching. Thus, a metal mask substrate 32S for vapor deposition with the desired thickness can be obtained. The thickness of the metal mask substrate 32S for vapor deposition is 15 μm or less, particularly 10 μm or less. Since the metal mask substrate 32S for vapor deposition is difficult to process, before thinning the Invar alloy sheet, the Invar alloy sheet is bonded to the glass substrate 42 via a resin layer 41 serving as a support layer. The resin layer 41 is preferably formed of polyimide. When thinning the Invar alloy sheet, the entire surface of the Invar alloy sheet is etched using an etching solution.

[0128] Next, a resist layer PR is formed on one of the target surfaces of the metal mask substrate 32S for vapor deposition (see reference). Figure 6B Then, by exposing and developing the resist layer PR, a resist mask RM is formed on the object surface (refer to...). Figure 6C ).

[0129] In the manufacturing method of the metal mask 32 for vapor deposition, an etching method is used in which the metal mask substrate 32S for vapor deposition is selectively dissolved using an etching solution. The etching method can be either a single-sided etching method (see Figure 6) or a double-sided etching method (see Figure 8) that processes from only one side, as described above. Since the size of the surface opening H1 and the back opening H2 can be controlled, a double-sided etching method is preferred; however, when the thickness of the metal sheet is 15 μm or less, a single-sided etching method is used as described above. Furthermore, when the thickness of the metal mask substrate 32S for vapor deposition is thick enough to warrant a double-sided etching method, the metal mask sheet 30 for vapor deposition is usually composed solely of the metal mask 32.

[0130] In a metal mask substrate 32S for vapor deposition with a resist layer PR, the resist layer PR is patterned using photolithography. The resist layer PR can be formed from a negative photosensitive resin or a positive photosensitive resin. When using a negative photosensitive resin, the portions of the resist layer PR without openings are exposed through a mask with the desired pattern, while when using a positive photosensitive resin, the portions of the resist layer PR with openings are exposed through a mask with the desired pattern. The light source used for exposing the resist layer PR can be a conventional high-pressure mercury lamp or the like. Furthermore, the resist layer PR can be a dry film resist covered by a carrier film or a resist layer formed from a coating solution.

[0131] Next, when using dry film resist, after peeling the carrier film off the dry film resist, the dry film resist is developed. An alkaline aqueous solution is used as the developer. Examples of alkaline aqueous solutions include aqueous solutions of sodium hydroxide, sodium carbonate, sodium bicarbonate, amines, or mixtures thereof, or aqueous solutions containing appropriate surfactants. After developing the resist layer PR, the resist mask RM obtained by developing the resist layer PR is dried using a hot air dryer and an IR (Infrared Radiation) dryer.

[0132] In order to form mask holes 32H on the vapor deposition metal mask substrate 32S located on the glass substrate 42 via the resin layer 41, the vapor deposition metal mask substrate 32S is etched using an acidic etching solution (see reference). Figure 6D Etching of the metal mask substrate 32S for vapor deposition can be performed under known conditions. For example, an acidic etching solution can be used, such as a solution containing perchloric acid, hydrochloric acid, sulfuric acid, formic acid, or acetic acid, in a solution of ferric perchlorate or a mixture of ferric perchlorate and ferric chloride. The etching method can be an immersion method, in which the metal mask substrate 32S for vapor deposition is immersed in the acidic etching solution; a spray method, in which the acidic etching solution is blown onto the metal mask substrate 32S for vapor deposition; or a rotation method, in which the acidic etching solution is dropped onto the metal mask substrate 32S for vapor deposition, which is rotated by a rotator. Next, the resist mask RM is removed from the surface of the metal mask substrate 32S for vapor deposition (see reference). Figure 6E ).

[0133] With a support layer, namely a resin layer 41 formed of polyimide and a glass substrate 42, mounted on the back side 32b of the metal mask substrate 32S for vapor deposition, the surface roughness of surface 32a is adjusted using a chemical polishing slurry. The chemical polishing slurry for adjusting the surface roughness is an acidic solution containing an oxidizing agent. The acidic solution is generally a combination of an oxidizing agent, an acid (i.e., any one of inorganic and organic acids), and a stabilizer. That is, the acidic solution contains an oxidizing agent, an acid, and a stabilizer.

[0134] The composition of the acidic solution depends on the type of metal being chemically polished. When it is an iron-nickel alloy, hydrogen peroxide can be used as the oxidant in addition to the aforementioned acidic etching solution. Specifically, the oxidant can be hydrogen peroxide, the acid can be sulfuric acid or a fluorinated acid, and the stabilizer can be acetamide, benzamide, phenol, ethanol, ethylene glycol, etc. Furthermore, in addition to the oxidant, acid, and stabilizer, the acidic solution can also contain pit inhibitors, other inorganic or organic acids, etc., and the acidic solution can be prepared by diluting these materials with water. The surface roughness Sa of surface 32a can be adjusted by changing at least one of the processing temperature and processing time using the chemical polishing slurry.

[0135] For a metal mask substrate 32S for evaporation with adjusted surface roughness Sa, an anti-fouling layer 32AF is provided on the metal mask substrate 32S from the surface 32a side (see reference). Figure 6F As described above, the material forming the antifouling layer 32AF can be appropriately selected from materials that are insoluble in solvents and whose adhering residues are easily removed. For example, as the antifouling layer 32AF of the present invention, conventionally known antifouling materials in the fields of "antireflective films" and "hydrophobic sheets" can be used.

[0136] Specific materials include, for example, release materials. These release materials are insoluble in solvents and can form an antifouling layer 32AF at a temperature that does not deform the metal mask substrate 32S used for vapor deposition. Release materials can be fluorinated compounds, silicone resins, etc. From the viewpoint of improving antifouling properties and adhesion to the metal mask substrate 32S used for vapor deposition, fluorinated compounds are preferred. Since the surface free energy of silicone resins is greater than that of fluorinated compounds, their antifouling properties are worse than those of fluorinated compounds. In other words, since the surface free energy of fluorinated compounds is lower than that of silicone resins, their antifouling properties are superior to those of silicone resins. Furthermore, when removing vapor deposition materials using ultrasonic cleaning, silicone resins, compared to fluorinated compounds, have lower adhesion to the metal serving as the metal mask substrate 32S used for vapor deposition, making it easier for the antifouling layer to peel off from the metal mask substrate 32S used for vapor deposition. In other words, compared to silicone resins, fluorinated compounds have a higher adhesion to metals, making it more difficult for the antifouling layer to peel off from the metal mask substrate 32S used for vapor deposition. Fluorinated compounds are preferably fluorinated polyether compounds.

[0137] Specific examples of fluorinated polyether compounds include SURECO (registered trademark) AF series 2101S, 2120 (manufactured by AGC), SIFEL (registered trademark) 2000 series (manufactured by Shin-Etsu Chemical Co., Ltd.), and Fluorolink (registered trademark) series P56, P54, F10, S10, A10P, AD1700, MD700 (manufactured by Solvay).

[0138] When the thickness of the antifouling layer 32AF is increased, the thickness of the metal mask substrate 32S for vapor deposition on the surface also increases. This can lead to situations where shadows cannot be prevented due to the increased thickness of the antifouling layer 32AF. Therefore, the thickness of the antifouling layer 32AF is preferably determined with this in mind. Specifically, the thickness of the antifouling layer 32AF is preferably 100 nm or less. From the viewpoint of improving the ease of forming the antifouling layer 32AF, the thickness of the antifouling layer 32AF is preferably 20 nm or less, and more preferably 5 nm or more but 10 nm or less.

[0139] The back surface 32b of the metal mask substrate 32S for vapor deposition is supported by a resin layer 41 serving as a support layer. There are no particular limitations on the method for forming the antifouling layer 32AF on the metal mask substrate 32S for vapor deposition. An antifouling layer 32AF, formed by dissolving or dispersing a material for forming the antifouling layer 32AF in a suitable solvent, can be applied to the surface 32a of the metal mask substrate 32S with a coating liquid, followed by heating the coating liquid to form the antifouling layer 32AF. The coating liquid can be applied using conventionally known methods such as spraying, spin coating, dip coating, curtain coating, and mold coating. Furthermore, when using these coating methods, the antifouling layer 32AF is also formed on the unetched portions of the surface 32a and on the inner wall surfaces of the mask holes 32H with inverted frustum shapes on the metal mask substrate 32S for vapor deposition. By forming an antifouling layer 32AF on the surface 32a and the inner wall surface of the mask hole 32H, even if residue adheres to the flat surface of the surface 32a and the inner wall surface of the mask hole 32H, the adhered residue can be easily removed by washing. However, it is preferable not to form an antifouling layer 32AF around the joint 31BN of the surface 32a and the mask frame 31, i.e., in the area including the portion where the joint 31BN is formed. Therefore, in the area of ​​the surface 32a including the portion where the joint 31BN is formed, a masking layer is pre-formed before forming the antifouling layer 32AF, so that the antifouling layer 32AF is not formed.

[0140] By removing the resin layer 41 and the glass substrate 42 from the metal mask substrate 32S for evaporation having the anti-fouling layer 32AF, a metal mask 32 for evaporation having the metal mask substrate 32S for evaporation and the anti-fouling layer 32AF can be obtained (see reference). Figure 6G When removing the resin layer 41 and the glass substrate 42 from the metal mask substrate 32S for thin film deposition, the metal mask 32 is thin, making its processing difficult. Therefore, as previously referred to... Figure 4 As shown in FIG5, and as described below with reference to FIG7, after the metal mask 32 for evaporation is bonded to the mask frame 31, the resin layer 41 and the glass substrate 42 are peeled off from the metal mask 32 for evaporation.

[0141] like Figures 7A to 7C As shown, in the outer peripheral edge portion 32E, the portion contained in the surface 32a is joined to the inner edge portion 31E (see reference). Figure 7A Then, the glass substrate 42 bonded to each resin layer 41 is peeled off (see reference). Figure 7B Next, the resin layer 41 bonded to the metal mask substrate 32S for evaporation is peeled off from each evaporation metal mask 32 (see reference). Figure 7CThus, the aforementioned metal mask sheet 30 for vapor deposition is obtained. Furthermore, in FIG. 7, for ease of illustration, the number of metal masks 32 bonded to the metal mask sheet 30 for vapor deposition is less than [number missing]. Figure 5A The number of vapor deposition metal masks 32 attached to the vapor deposition metal mask sheet 30 is shown.

[0142] The process of joining a portion of the vapor deposition metal mask 32 and a portion of the mask frame 31 is a process of joining the side of the vapor deposition metal mask 32 opposite to the side that contacts the resin layer 41 onto the mask frame 31. As described above, the mask frame 31 is preferably made of an iron-nickel alloy or an iron-nickel-cobalt alloy, and preferably the thickness of the mask frame 31 is more than twice the thickness of the vapor deposition metal mask 32. This improves the mechanical strength of the vapor deposition metal mask sheet 30. Furthermore, during vapor deposition using the vapor deposition metal mask sheet 30, warping of the vapor deposition metal mask 32 caused by the difference in thermal expansion coefficients between the mask frame 31 and the vapor deposition metal mask 32 can be suppressed. This suppresses the decrease in the shape accuracy of the pattern formed using the vapor deposition metal mask sheet 30.

[0143] As described above, in the vapor deposition metal mask sheet 30 having a vapor deposition metal mask 32, when the thickness of the vapor deposition metal mask 32 is 3 μm or more and 15 μm or less, it is preferable that the thickness of the mask frame 31 is 15 μm or more and 200 μm or less, and the thickness of the mask frame 31 is more than twice that of the vapor deposition metal mask 32. Furthermore, in the vapor deposition metal mask sheet 30 having a vapor deposition metal mask 32 capable of manufacturing a high-resolution display device, when the thickness of the vapor deposition metal mask 32 is 3 μm or more and 5 μm or less, it is preferable that the thickness of the mask frame 31 is 50 μm or more and 200 μm or less, and the thickness of the mask frame 31 is more than 10 times that of the vapor deposition metal mask 32. Since the metal mask 32 for vapor deposition is extremely thin, by making the thickness of the mask frame 31 more than 10 times the thickness of the metal mask substrate 32S for vapor deposition, the reduction in the overall mechanical strength of the metal mask sheet 30 for vapor deposition can be suppressed.

[0144] exist Figure 7AIn the method shown, where the outer peripheral edge 32E is joined to the inner edge 31E, laser welding can be used. A first laser beam L1 is irradiated through the glass substrate 42 and the resin layer 41 onto the portion of the metal mask 32 where the joining portion 31BN is located. The wavelength of the first laser beam L1 can be, for example, 355 nm, 1064 nm, or 1070 nm. Therefore, the glass substrate 42 and the resin layer 41 are transmissive to the first laser beam L1. In other words, the first laser beam L1 has a wavelength that can pass through the glass substrate 42 and the resin layer 41. Furthermore, intermittent joining portions 31BN are formed by intermittently irradiating the first laser beam L1 along the edge of the mask frame hole 33. On the other hand, continuous joining portions 31BN are formed by continuously irradiating the first laser beam L1 along the edge of the mask frame hole 33. Additionally, the glass substrate 42 may also have through holes at the locations where the first laser beam L1 is irradiated for its passage. At this time, compared with the glass substrate 42 having no through hole, the power of the first laser beam L1 can be reduced.

[0145] Therefore, the outer peripheral edge 32E of the vapor deposition metal mask 32 is fused with the inner edge 31E of the mask frame 31. Furthermore, when stress is applied to the vapor deposition metal mask 32 toward the outside of the vapor deposition metal mask 32, and the vapor deposition metal mask 32 is supported by the resin layer 41 formed of polyimide and the glass substrate 42, the application of stress to the vapor deposition metal mask 32 can be omitted during the welding of the vapor deposition metal mask 32 to the mask frame 31.

[0146] like Figure 7B as well as Figure 7C As shown, the manufacturing method of the vapor deposition metal mask sheet 30 includes a peeling process. The peeling process is the process of peeling the resin layer 41 and the glass substrate 42 from the vapor deposition metal mask 32. The vapor deposition metal mask 32, which includes a plurality of mask holes 32H, is supported by the resin layer 41 and the glass substrate 42 during the manufacturing of the vapor deposition metal mask sheet 30, and is also supported by the mask frame 31 within the vapor deposition metal mask sheet 30. Therefore, compared to when the vapor deposition metal mask sheet 30 is composed solely of the vapor deposition metal mask 32, the thickness of the vapor deposition metal mask substrate 32S can be reduced. Therefore, by shortening the distance between one surface opening H1 and another back opening H2 of the mask holes 32H, the structural accuracy of the pattern formed using the vapor deposition metal mask sheet 30 can be improved, and the rigidity of the mask frame 31 can improve the processability of the vapor deposition metal mask sheet 30.

[0147] The stripping process includes a first stripping process (see reference). Figure 7B ) and the second stripping process (refer to Figure 7CThe first peeling process involves irradiating the interface between the resin layer 41 and the glass substrate 42 with a second laser beam L2 having a wavelength that transmits through the glass substrate 42 and is absorbed by the resin layer 41, thereby peeling the glass substrate 42 off from the resin layer 41. The wavelength of the second laser beam L2 is preferably 308 nm or more and 355 nm or less.

[0148] In the first peeling process, a second laser beam L2 is irradiated onto the interface between the resin layer 41 and the glass substrate 42, causing the heat generated by the second laser beam L2 to be absorbed by the resin layer 41. This heating of the resin layer 41 reduces the strength of the chemical bond between the resin layer 41 and the glass substrate 42. Consequently, the glass substrate 42 is peeled off from the resin layer 41. In the first peeling process, it is preferable to irradiate the entire bonding portion 31BN with the second laser beam L2; however, as long as the bonding strength between the glass substrate 42 and the resin layer 41 can be reduced throughout the bonding portion 31BN, the second laser beam L2 may also be irradiated onto a portion of the bonding portion 31BN.

[0149] In the wavelength of the second laser beam L2, it is preferable that the transmittance of the glass substrate 42 is higher than that of the resin layer 41. Therefore, compared with the case where the transmittance of the resin layer 41 is higher than that of the glass substrate 42, the efficiency of heating the portion forming the interface between the glass substrate 42 and the resin layer 41 can be improved in the resin layer 41.

[0150] When the wavelength of the second laser beam L2 is, for example, 308 nm or more and 355 nm or less, the transmittance of the glass substrate 42 is preferably 54% or more and the transmittance of the resin layer 41 is 1% or less at this wavelength. Thus, more than half of the light intensity of the second laser beam L2 irradiating the glass substrate 42 passes through the glass substrate 42, and the vast majority of the second laser beam L2 after passing through the glass substrate 42 is absorbed by the resin layer 41. Therefore, the efficiency of heating the portion forming the interface between the glass substrate 42 and the resin layer 41 can be further improved in the resin layer 41.

[0151] As described above, the resin layer 41 is preferably formed of polyimide, especially colored polyimide. Furthermore, the glass substrate 42 is preferably transparent. The material used to form the glass substrate 42 can be quartz glass, alkali-free glass, soda lime glass, crystallized glass, borosilicate glass, high-silicate glass, and porous glass, etc.

[0152] The second stripping step involves exposing the resin layer 41, the vapor deposition metal mask 32, and the mask frame 31 to a chemical solution LM after the first stripping step. The chemical solution LM dissolves the resin layer 41, thereby stripping it from the vapor deposition metal mask substrate 32S. This chemically removes the resin layer 41 from the vapor deposition metal mask substrate 32S. The chemical solution LM can be a liquid capable of dissolving the material used to form the resin layer 41 and non-reactive to the material forming the vapor deposition metal mask 32. For example, an alkaline solution can be used. Examples of alkaline solutions include aqueous sodium hydroxide solution. Furthermore, Figure 7C In this example, the impregnation method is used as a method to bring the resin layer 41 into contact with the liquid LM, but spraying and rotary methods can also be used to bring the resin layer 41 into contact with the liquid LM.

[0153] Thus, in the process of peeling the resin layer 41 and the glass substrate 42 from the metal mask substrate 32S for vapor deposition, the glass substrate 42 is peeled from the resin layer 41 in a first peeling step, and the resin layer 41 is peeled from the metal mask substrate 32S for vapor deposition in a second peeling step. Therefore, compared to peeling the glass substrate 42 and the resin layer 41 from the metal mask substrate 32S due to interface damage caused by external forces applied to the laminate of the glass substrate 42, the resin layer 41, and the metal mask 32 for vapor deposition, the external force acting on the metal mask 32 for vapor deposition can be reduced. As a result, deformation of the metal mask 32 for vapor deposition caused by the peeling of the resin layer 41 and the glass substrate 42, and consequently deformation of the mask holes 32H of the metal mask 32 for vapor deposition, can be suppressed.

[0154] Furthermore, the material forming the resin layer 41 is not limited to polyimide; for example, it can also be an ultraviolet (UV) curable adhesive. In this case, when the resin layer 41 and the glass substrate 42 are peeled off from the vapor deposition metal mask substrate 32S, the resin layer 41 can be exposed to UV light and cured, thereby reducing the adhesion of the resin layer 41 to the vapor deposition metal mask substrate 32S. Then, by peeling the resin layer 41 off the vapor deposition metal mask substrate 32S, both the resin layer 41 and the glass substrate 42 can be removed from the vapor deposition metal mask substrate 32S simultaneously.

[0155] Furthermore, when forming the resin layer 41 using an adhesive, a UV-curable easy-peel adhesive film can be used, for example. By attaching one side of the UV-curable easy-peel adhesive film to the metal mask substrate 32S for vapor deposition and attaching the other side of the UV-curable easy-peel adhesive film to the glass substrate 42, a resin layer 41 located between the glass substrate 42 and the metal mask substrate 32S for vapor deposition can be formed.

[0156] On the other hand, when the thickness of the metal mask substrate 32S for vapor deposition is greater than 15 μm, especially greater than 20 μm, the double-sided etching method shown in FIG8 is used as the manufacturing method for the metal mask 32 for vapor deposition. In the double-sided etching method, in order to adjust the size of the back opening H2 and the surface opening H1 of the metal mask substrate 32S for vapor deposition, it is necessary to change the etching amount of each, that is, it is necessary to form the back opening H2 and the surface opening H1 through different etching processes.

[0157] After acid treatment of the surface 32a and back surface 32b of the metal mask substrate 32S for vapor deposition using hydrochloric acid or sulfuric acid, a resist layer PR for pattern formation is formed (see reference). Figure 8A Specifically, a resist layer PRa is formed on surface 32a, and a resist layer PRb is formed on back surface 32b. The resist material can be a negative photosensitive resin that cures in the UV-exposed portion, or a positive photosensitive resin that dissolves in the developer in the UV-exposed portion. Alternatively, the resist layer PR can be formed by laminating a dry film resist onto a metal mask substrate 32S for vapor deposition while applying heat to the dry film resist. Another method for forming the resist layer PR is to coat a liquid resist material onto a metal plate using gravure coating or screen coating to form a coating film, and then remove the solvent from the coating film using a hot air dryer or similar method.

[0158] In the metal mask substrate 32S for evaporation where resist layers PRa and PRb are formed, the patterning of the resist layers PRa and PRb is performed using photolithography (see reference). Figure 8B The resist layers PRa and PRb can be formed from either a negative or positive photosensitive resin. When using a negative photosensitive resin, the portions of the resist layers PRa and PRb without openings are exposed using a mask with the desired pattern. Conversely, when using a positive photosensitive resin, the portions of the resist layers PRa and PRb with openings are exposed. A conventional high-pressure mercury lamp or similar light source can be used for exposing the resist layers PRa and PRb.

[0159] Next, when using dry film resist, after peeling the carrier film from the dry film resist, the dry film resist is developed, thereby forming resist masks RMa and RMB. An alkaline aqueous solution is used as the developer. Examples of alkaline aqueous solutions include aqueous solutions of sodium hydroxide, sodium carbonate, sodium bicarbonate, amines, or mixtures thereof, or aqueous solutions with appropriate surfactants added. After developing the resist layers PRa and PRb, the resist layers PRa and PR are dried using a hot air dryer and an IR (Infrared Radiation) dryer.

[0160] When etching either the back surface 32b or the surface 32a, a resin layer 43a as a protective layer is formed in such a way that the other surface is not etched (see reference). Figure 8C In the formation of resin layer 43a, an adhesive film and a liquid photosensitive resin, or polyimide, are used. When double-sided etching is employed, generally, in order to form a back opening H2 with a relatively small diameter, the metal mask substrate 32S for vapor deposition is etched from the back side 32b. That is, the back opening H2 is formed on the metal mask substrate 32S for vapor deposition earlier than the surface opening H1. In this case, the resin layer 43a, serving as a protective layer for the surface 32a, is preferably an adhesive film. Thus, the resin layer 43a can be formed on the resist mask RMa, and the resin layer 43a can be peeled off from the resist mask RMa. Furthermore, the resin layer 43a also functions as a support when transporting the metal mask substrate 32S for vapor deposition.

[0161] After forming a resin layer 43a on surface 32a, in order to form a back opening H2 on the back side 32b on the metal mask substrate 32S for evaporation, etching is performed using an acidic etching solution (see reference). Figure 8D The etching conditions are the same as those described above for single-sided etching.

[0162] In order to form a resin layer 43b as a protective layer for the back side 32b, the resist mask RMBb is peeled off from the vapor deposition metal mask substrate 32S on which the back side opening H2 is formed (see reference). Figure 8E The stripping can be carried out under known conditions. For example, an alkaline stripping solution can be used for the stripping of the resist mask RMb. The alkaline stripping solution can be, for example, an aqueous solution of sodium hydroxide, an aqueous solution of sodium carbonate, an aqueous solution of sodium bicarbonate, an aqueous solution of an amine, or a mixture thereof, or an aqueous solution containing a suitable surfactant.

[0163] Following the method of etching the surface 32a without etching the back side 32b, a resin layer 43b is formed as a protective layer for the back side 32b using a coating or printing method (see reference). Figure 8F In the formation of resin layer 43b, a photosensitive resin is used as a liquid varnish. The thickness of resin layer 43b is preferably 5 μm or more and 20 μm or less. At this time, the varnish is filled into the back recess 32SH formed on the metal mask substrate 32S for vapor deposition, thereby forming resin layer 43b in such a way that the back recess 32SH is embedded in the varnish. In addition, resin layer 43b may also be formed of polyimide. When resin layer 43b is formed of polyimide, resin layer 43b is preferably formed by forming a film of polyimide solution, polyamic acid solution, etc. by coating or printing method, and then curing the film by heat treatment or the like.

[0164] In order to form the surface opening H1 and thereby connect the surface opening H1 to the back opening H2, the surface 32a is etched after the resin layer 43a is peeled off (see reference). Figure 8G , Figure 8H The etching of surface 32a can be performed using the same etching solution as the etching of back surface 32b.

[0165] After the resist mask RMa is peeled off from the vapor deposition metal mask substrate 32S having surface openings H1 and back openings H2, an anti-fouling layer 32AF is applied under the conditions described above in the single-sided etching method (see reference). Figure 8I , Figure 8J When forming the antifouling layer 32AF on the metal mask substrate 32S for vapor deposition, a resin layer 43b is formed on the back side of the metal mask substrate 32S for vapor deposition, and the back recess 32SH is filled by the resin layer 43b. Therefore, when the antifouling layer 32AF is formed in a manner that covers the surface 32a of the metal mask substrate 32S for vapor deposition, the antifouling layer 32AF is formed in a manner that covers the surface 32a and the inner wall surface of the surface recess 32SH of the metal mask substrate 32S for vapor deposition. On the other hand, the antifouling layer 32AF is not formed on the back side 32b and the inner wall surface of the back recess 32SH of the metal mask substrate 32S for vapor deposition. Therefore, halogen compounds are not located on the back side 32b and the inner wall surface of the back recess 32SH.

[0166] Based on the metal mask 32 for vapor deposition obtained by double-sided etching, by peeling the resin layer 43b from the back surface 32b of the metal mask substrate 32S, the metal mask sheet 30 for vapor deposition can be constructed solely from the metal mask 32 (see reference). Figure 8K Furthermore, an alkaline solution can be used when peeling the photosensitive resin or the resin layer 43b formed of polyimide from the metal mask substrate 32S for vapor deposition. This allows the resin layer 43b to be chemically removed from the metal mask substrate 32S for vapor deposition. An example of an alkaline solution is an aqueous solution of sodium hydroxide.

[0167] Alternatively, similar to the operation in the single-sided etching method, after the metal mask 32 for vapor deposition is attached to the mask frame 31, the resin layer 43b is peeled off from the back side 32b to form the metal mask sheet 30 for vapor deposition.

[0168] Furthermore, when the metal mask sheet 30 for vapor deposition includes a mask frame 31, an anti-fouling layer can be provided on the frame surface 31a of the mask frame 31 facing the vapor deposition source and on the side surface of the mask frame hole 33. Additionally, when the mask frame 31 includes an anti-fouling layer, it is preferable that the anti-fouling layer is not located on the back surface 31b of the mask frame 31. That is, it is preferable that halogen compounds are not located on the back surface 31b of the mask frame 31.

[0169] In the method for manufacturing a display device using the aforementioned metal mask sheet 30 for vapor deposition, the mask assembly 10, on which the metal mask sheet 30 for vapor deposition is mounted, is first installed in the vacuum chamber of the vapor deposition apparatus. At this time, the mask assembly 10 is installed in the vacuum chamber with the vapor deposition object, such as a glass substrate, facing the back surface 32b of the metal mask substrate 32S, and the vapor deposition source facing the anti-fouling layer 32AF. Then, the vapor deposition object is placed into the vacuum chamber, and the vapor deposition material is sublimated by the vapor deposition source. Thus, based on the metal mask 32 formed by etching the metal mask substrate 32S from only one side, a pattern having a shape following the back opening H2 is formed on the vapor deposition object facing the back opening H2. In contrast, a pattern is formed on the vapor deposition object facing the back opening H2 by etching both the surface 32a and the back surface 32b of the vapor deposition metal mask substrate 32S, with a shape following the surface recess 32LH and connected to the back recess 32SH. Furthermore, the vapor deposition material can be, for example, an organic light-emitting material constituting the pixels of the display device, or a pixel electrode forming material constituting the pixel circuit of the display device.

[0170] [Example]

[0171] The following describes the embodiments and comparative examples with reference to Table 1.

[0172] [Example 1]

[0173] A metal sheet, made of rolled Invar alloy, is prepared, having a square shape of 110mm × 110mm (i.e., one side length of 110mm) and a thickness of 100μm. A glass substrate 42 is chemically bonded to the back side of the metal sheet via a polyimide film (manufactured by Kapton EN, DuPont, 5μm thick), thereby forming a support layer on the back side of the metal sheet. The polyimide film is an example of a resin layer 41 serving as the support layer.

[0174] Next, the surface of the metal sheet was degreased using a 30% sodium hydroxide aqueous solution as a degreasing agent, and then acid-treated with 10% hydrochloric acid. An aqueous solution containing 4.21% acidic ammonium fluoride in 26% hydrogen peroxide water was prepared as the stock solution for the chemical polishing slurry. This stock solution was diluted twice with pure water to prepare the chemical polishing slurry. The surface of the metal sheet was immersed in the chemical polishing slurry heated to 50°C for 15 minutes, thereby adjusting the thickness of the metal sheet to 10.2 μm and the surface roughness Sa to 10.1 nm. This yielded a metal mask substrate 32S for vapor deposition.

[0175] A negative-film dry resist is applied to the surface 32a of the metal mask substrate 32S for vapor deposition, forming a resist layer PR. In the metal mask substrate 32S, the pattern portion forming the mask holes 32H is defined as a 99mm × 99mm area in the center of the metal mask substrate 32S. That is, a square pattern portion with one side length of 99mm is formed in the metal mask substrate 32S such that the center of the metal mask substrate 32S coincides with the center of the pattern portion. Furthermore, a square area with a perimeter of 100mm × 100mm, i.e., one side length of 100mm, is also formed in the metal mask substrate 32S. The perimeter has a rectangular frame surrounding the pattern portion, and the width of the perimeter is set to 1mm.

[0176] After exposing the resist layer PR using an exposure mask with a Hole 50μm / Rib 50μm (i.e., circular light-shielding parts with a diameter of 50μm arranged in a grid pattern at 100μm intervals), the resist layer PR is developed using a 1% sodium carbonate aqueous solution. The vapor deposition metal mask substrate 32S with the resist layer PR is washed with water and then dried at 100°C. The patterned resist layer PR, i.e., the vapor deposition metal mask substrate 32S with the resist mask RM, thus formed is etched using a 48% ferric chloride aqueous solution as an etching solution via spraying. This forms a surface opening H1 and a back opening H2 on the vapor deposition metal mask substrate 32S. Then, the resist mask RM is peeled off from the vapor deposition metal mask substrate 32S using a 10% sodium hydroxide aqueous solution as a resist stripping solution. Then, the metal mask substrate 32S for vapor deposition is washed with water and then dried.

[0177] After forming a coating by applying a 0.1% diluted SUREC02120 (manufactured by AGC) aqueous solution to a metal mask substrate 32S for vapor deposition using a two-fluid spraying device, the coated metal mask substrate 32S is heated at 120°C for 10 minutes. This forms an anti-fouling layer 32AF on the surface 32a and the inner wall of the mask aperture 32H in the metal mask substrate 32S for vapor deposition.

[0178] Next, a mask frame 31 formed from rolled Invar alloy material is prepared. The mask frame 31 has a length of 400 mm in the length direction and a width of 50 mm, and has three mask frame holes 33. Using an infrared laser with a wavelength of 1064 nm, the metal mask substrate 32S for evaporation is bonded to the mask frame 31 such that one metal mask substrate 32S for evaporation covers one mask frame hole 33. Then, after peeling off the glass substrate 42 using an ultraviolet laser with a wavelength of 308 nm, that is, after peeling the glass substrate 42 from the resin layer 41, the resin layer 41 is peeled off from the metal mask substrate 32S for evaporation using an alkaline solution. Thus, the metal mask sheet 30 for evaporation of Example 1 is obtained.

[0179] In the dimensional measurement, i.e., the surface roughness Sa, an OLS-4000 laser microscope (manufactured by Olympus Corporation) was used. For elemental analysis, a scanning electron microscope S-4800 (manufactured by Hitachi High Technologies Corporation) was used in SEM-EDX mode to perform elemental analysis on the surface 32a and back surface 32b of the vapor deposition metal mask 32. The presence or absence of halogen atom peaks was used to determine whether there was fluorination treatment on each surface 32a and 32b, or contamination such as halogen compound adhesion. The thickness of the vapor deposition metal mask 32 was measured using a micrometer K352C (manufactured by Anritsu Corporation). Furthermore, pure water was added to each surface, and the contact angles of the surface and back surface of the vapor deposition metal mask 32 were measured using a CA-X type contact angle meter (manufactured by Kyowa Interface Science).

[0180] The washing tolerance was evaluated using the following method. Specifically, the metal mask 32 used in the vapor deposition of αNPD (N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4'-diamine) was washed using an ultrasonic cleaner (W-118 ultrasonic cleaner, manufactured by Honda Electronics Co., Ltd.). The metal mask 32 was washed for one minute, with cycles of 28 kHz / 5 seconds, 45 kHz / 5 seconds, and 100 kHz / 5 seconds. The maximum power of the ultrasonic cleaner was set to 600 W, and the power was adjusted appropriately by reducing it to below 600 W for washing the metal mask 32.

[0181] The evaluation criteria were mask strength and organic matter removal. Regarding mask strength, the metal mask 32 used for vapor deposition was assessed for wrinkles before and after washing. No wrinkles were marked as "0" after washing, and wrinkles were marked as "×". Regarding organic matter removal, the presence of organic matter, i.e., the presence or absence of vapor deposition material buildup, was determined by visual inspection under a microscope. No organic matter was marked as "0", and organic matter residue was marked as "×". The evaluation results are shown in Table 1 below.

[0182] Table 1

[0183]

[0184] [Examples 2-7]

[0185] As shown in Table 1, the thickness of the metal sheet in Example 1 was changed, and the surface roughness Sa was adjusted by the concentration and processing temperature of the chemical polishing slurry, i.e., the temperature of the chemical polishing slurry. Otherwise, the same operations as in Example 1 were performed, thereby obtaining the vapor deposition metal mask sheets 30 of Examples 2 to 7. The results of evaluating the vapor deposition metal mask sheets 30 in the same manner as in Example 1 are shown in Table 1.

[0186] [Example 8]

[0187] A metal sheet made of rolled Invar alloy, measuring 110 mm × 110 mm (i.e., one side length of 110 mm), and with a thickness of 100 μm, was prepared. The surface of the metal sheet was degreased using a 30% sodium hydroxide aqueous solution, followed by acid treatment with 10% hydrochloric acid. At this time, the same chemical polishing slurry as in Example 1 was prepared, and the surface of the metal sheet was acid-treated under the same conditions as in Example 1. This adjusted the thickness of the metal sheet to 99.6 mm and the surface roughness Sa of the metal sheet to 10.5 nm. Thus, a metal mask substrate 32S for vapor deposition was obtained.

[0188] A negative-type dry film resist is applied to both sides of a metal mask substrate 32S for vapor deposition to form a resist layer PR. On the back side 32b of the metal mask substrate 32S, a back pattern portion forming a back opening H2 in the mask aperture 32H is set to have a size of 99mm × 99mm in the center of the back side 32b. That is, a square back pattern portion with a side length of 99mm is formed in the metal mask substrate 32S such that the center of the back side 32b coincides with the center of the back pattern portion. An exposure mask with a Hole: 30μm / Rib: 70μm (i.e., circular light-shielding portions with a diameter of 30μm arranged in a grid pattern at 100μm intervals) is used to expose the resist layer PRb.

[0189] Furthermore, in the metal mask substrate 32S for vapor deposition, the surface pattern portion forming the surface opening H1 in the mask hole 32H is set to have a 99mm × 99mm area in the center of the surface 32a. That is, a square surface pattern portion with a side length of 99mm is set in the metal mask substrate 32S for vapor deposition, such that the center of the surface 32a coincides with the center of the surface pattern portion. Then, an exposure mask with a Hole: 50μm / Rib: 50μm, that is, a circular light-shielding portion with a diameter of 50μm arranged in a grid pattern at 100μm intervals, is used to expose the resist layer PRa. In addition, in the exposure mask used to expose the resist layer PRb located on the back side 32b, the positions of the two exposure masks are aligned such that the center of each opening faces the center of the opening formed in the exposure mask used to expose the resist layer PRa located on the surface 32a. Subsequently, the resist layers PRa and PRb were developed using a 1% sodium carbonate aqueous solution, thereby forming the resist masks RMb and RMa.

[0190] After washing with water, the vapor deposition metal mask substrate 32S, which includes resist masks RMa and RMB, is dried at 100°C. Next, a resin layer 43a, formed of an adhesive film, is applied as a protective layer onto the resist mask RMa on the surface 32a of the vapor deposition metal mask substrate 32S. Using a 48% ferric chloride aqueous solution as an etching solution, the vapor deposition metal mask substrate 32S with the resist mask RMB on the back side 32b is etched by spraying. This forms a back side opening H2 and a back side recess 32SH on the vapor deposition metal mask substrate 32S.

[0191] Then, using a 10% sodium hydroxide aqueous solution as a resist stripping solution, the resist mask RMBb is peeled off from the vapor deposition metal mask substrate 32S. Next, the vapor deposition metal mask substrate 32S is washed with water and then dried.

[0192] A protective varnish made of photosensitive resin is applied to the back surface 32b of the etched metal mask substrate 32S using a bar coater. The varnish is then dried and cured, forming a resin layer 43b as a protective layer. Next, the resin layer 43a on the surface 32a of the metal mask substrate 32S is peeled off, and the surface 32a of the metal mask substrate 32S is etched using the same etching solution as the back surface 32b. This forms a surface opening H1 and a surface recess 32LH on the metal mask substrate 32S.

[0193] Next, the resist mask RMa is peeled off from the vapor deposition metal mask substrate 32S using a 10% sodium hydroxide aqueous solution as a resist stripping solution. Then, the vapor deposition metal mask substrate 32S is washed with water and dried. With the resin layer 43b attached to the back surface 32b of the vapor deposition metal mask substrate 32S, the same operation as in Example 1 is performed to form an anti-fouling layer 32AF on the surface 32a of the vapor deposition metal mask substrate 32S and the inner wall surface of the defined surface recesses 32LH. Afterwards, the resin layer 43b is peeled off from the vapor deposition metal mask substrate 32S to obtain the vapor deposition metal mask sheet 30 of Example 8.

[0194] [Comparative Example 1]

[0195] Except for omitting the anti-fouling layer 32AF in Example 6, the same operations as in Example 6 were performed to obtain the metal mask sheet 30 for vapor deposition of Comparative Example 1. Since the anti-fouling layer 32AF was not provided on the metal mask sheet 30 for vapor deposition in Comparative Example 1, even ultrasonic cleaning of the metal mask sheet 30 for vapor deposition failed to remove the deposits of the vapor deposition material. Furthermore, when the ultrasonic cleaning power was increased to remove the deposits of the vapor deposition material, wrinkles were generated in the metal mask sheet 30 for vapor deposition.

[0196] [Comparative Example 2]

[0197] Except for the absence of chemical polishing and the absence of the anti-fouling layer 32AF in Example 1, the same operations as in Example 1 were performed to obtain the metal mask sheet 30 for vapor deposition in Comparative Example 2. It was found that the surface roughness Sa of the metal mask sheet 30 for vapor deposition in Comparative Example 2 was 79.8 nm. Furthermore, since the anti-fouling layer 32AF was not provided on the metal mask sheet 30 for vapor deposition, even ultrasonic cleaning failed to remove the deposits of the vapor deposition material. Moreover, unless the ultrasonic cleaning power was increased to 600 W, the deposits of the vapor deposition material could not be removed, and wrinkles were formed in the metal mask sheet 30 for vapor deposition.

[0198] [Comparative Example 3]

[0199] Except for changing the chemical polishing conditions in Example 1, the same operations as in Example 1 were performed to obtain the metal mask sheet 30 for vapor deposition in Comparative Example 3. It was found that the surface roughness Sa of the metal mask sheet 30 for vapor deposition in Comparative Example 3 was 5.5 nm, which is less than 10 nm. Therefore, the deposits of vapor deposition material were easily removed. However, during vapor deposition, the vapor deposits accumulated on the metal mask sheet 30 peeled off from the metal mask sheet 30, and the peeled vapor deposits fell onto the vapor deposition source, thereby generating sparks. As a result, the vapor-deposited film surface, i.e., the film formed on the substrate by vapor deposition, became uneven.

[0200] [Comparative Example 4]

[0201] Except for the absence of chemical polishing in Example 1, the same operations as in Example 1 were performed to obtain the metal mask sheet 30 for vapor deposition in Comparative Example 4. It was found that the surface roughness Sa of the metal mask sheet 30 for vapor deposition in Comparative Example 4 was 98.6 nm, exceeding 80 nm. Therefore, even ultrasonic cleaning failed to remove the deposits of the vapor-deposited material. Furthermore, unless the ultrasonic cleaning power was increased to 600 W, the deposits of the vapor-deposited material could not be removed, resulting in wrinkles in the metal mask sheet 30 for vapor deposition.

[0202] [Comparative Example 5]

[0203] In Example 8, the resin layer 43b on the back side 32b was peeled off before the anti-fouling layer 32AF was applied, and then the anti-fouling layer 32AF was applied to the metal mask substrate 32S for vapor deposition, thereby obtaining the metal mask sheet 30 for vapor deposition of Comparative Example 5. Thus, a metal mask 32 for vapor deposition was obtained having the anti-fouling layer 32AF on both the surface 32a and the back side 32b of the metal mask substrate 32S for vapor deposition. Elemental analysis of the back side 32b of the metal mask 32 for vapor deposition confirmed that the back side 32b was contaminated due to the adhesion of fluorine compounds, which are halogen compounds. When halogen compounds are located on the back side 32b of the metal mask 32 for vapor deposition, the vapor deposition object such as the glass substrate becomes contaminated, and the halogen compounds reduce the luminous efficiency and lifetime of the light-emitting element, thus making it unusable as a metal mask 32 for vapor deposition.

[0204] Furthermore, the material forming the antifouling layer 32AF can be changed to a silicone resin or a mixture of silicone resin and fluorinated compounds, provided it possesses the required antifouling and adhesion properties for the antifouling layer 32AF. Examples of silicone resins include KR-400 (manufactured by Shin-Etsu Chemical Co., Ltd.), Modiper FS700 (manufactured by Nippon Oil Co., Ltd.), and Fullshade (manufactured by Toyochem Co., Ltd.). Examples of mixed materials include KR-400F (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0205] Symbol Explanation

[0206] 10 Mask assembly, 20 Main frame, 21 Main frame hole, 30 Metal mask sheet for vapor deposition, 31 Mask frame, 31E Inner edge, 31BN Joint, 31a Frame surface, 31b Frame back side, 32 Metal mask for vapor deposition, 32E Outer peripheral edge, 32a Surface, 32b Back side, 32H Mask hole, 32S Metal mask substrate for vapor deposition, 33 Mask frame hole, 41, 43a, 43b Resin layers, 42 Glass substrate, H1 Surface opening, H2 Back side opening, PR Resist layer, RM Resist mask.

Claims

1. A metal mask for vapor deposition, comprising a metal mask substrate for vapor deposition, The metal mask substrate for vapor deposition has the following features: A surface having a first opening facing the vapor deposition source of the vapor deposition apparatus; The back side, which is the side opposite to the surface described above and has a second opening smaller than the first opening; and A through hole, shaped like an inverted frustum, is inserted into the first opening and the second opening. The metal mask used for vapor deposition further includes an anti-fouling layer containing a fluorinated compound located on the surface and the inner wall surface defining the through holes, wherein the fluorinated compound is a fluorinated polyether compound. Halogen compounds containing halogen atoms are not located on the back side. The contact angle of the antifouling layer surface with water is greater than 90°. The surface roughness Sa of the surface of the metal mask substrate for vapor deposition is above 22.5 nm and below 80 nm.

2. A metal mask for vapor deposition, comprising a metal mask substrate for vapor deposition, The metal mask substrate for vapor deposition has the following features: A surface having a first opening facing the vapor deposition source of the vapor deposition apparatus; The back side, which is the side opposite to the surface described above and has a second opening smaller than the first opening; and A through hole leading to the first opening and the second opening comprises: a first hole portion including the first opening and having an inverted frustum shape; and a second hole portion including the second opening and having a frustum shape, and being smaller than the first hole portion. The metal mask used for vapor deposition has an anti-fouling layer containing a fluorinated compound on its surface and on the inner wall surface defining the first hole. The fluorinated compound is a fluorinated polyether compound. Halogen compounds containing halogen atoms are not located on the back side or on the inner wall surface defining the second hole. The contact angle of the antifouling layer surface with water is greater than 90°. The surface roughness Sa of the surface of the metal mask substrate for vapor deposition is above 22.5 nm and below 80 nm.

3. The metal mask for vapor deposition according to claim 1 or 2, wherein, The material forming the metal mask substrate for vapor deposition is an iron-nickel alloy or an iron-nickel-cobalt alloy.

4. The metal mask for vapor deposition according to claim 1 or 2, wherein, The thickness of the metal mask substrate used for vapor deposition is more than 1 μm and less than 100 μm.

5. The method for manufacturing a metal mask for vapor deposition as described in claim 1, comprising: Prepare a metal mask substrate for vapor deposition, which has a surface for forming a first opening facing a vapor deposition source in the vapor deposition apparatus, and a back surface located on the opposite side of the surface and for forming a second opening smaller than the first opening. A resin layer is formed on the back side; By wet etching the metal mask substrate for vapor deposition from the surface, a through hole with an inverted frustum shape is formed, thereby forming the first opening on the surface and the second opening on the back side; An antifouling layer containing fluorine compounds is formed on the surface and on the inner wall surface defining the through hole; as well as After the antifouling layer is formed, the metal mask substrate for vapor deposition and the resin layer are exposed to an alkaline solution, thereby chemically removing the resin layer from the metal mask substrate for vapor deposition.

6. The method for manufacturing a metal mask for vapor deposition according to claim 5, wherein, The resin layer is formed of polyimide.

7. The method for manufacturing a metal mask for vapor deposition as described in claim 2, comprising: Prepare a metal mask substrate for vapor deposition, which has a surface for forming a first opening facing a vapor deposition source in the vapor deposition apparatus, and a back surface located on the opposite side of the surface and for forming a second opening smaller than the first opening. A second hole having the second opening and a frustoconical shape is formed on the back side by wet etching; A resin layer is provided on the back side in a manner that covers the second opening; By wet etching the metal mask substrate for vapor deposition from the surface, a first hole and a first opening with an inverted frustum shape are formed, thereby forming a through hole through the second hole and the first hole; An antifouling layer containing fluorine compounds is formed on the surface and on the inner wall surface defining the first hole. as well as After the antifouling layer is formed, the resin layer and the metal mask substrate for vapor deposition are exposed to an alkaline solution, thereby chemically removing the resin layer from the metal mask substrate for vapor deposition.

8. The method for manufacturing a metal mask for vapor deposition according to claim 7, wherein, The resin layer is formed of photosensitive resin.

9. The method for manufacturing a metal mask for vapor deposition according to claim 7, wherein, The resin layer is formed of polyimide.

10. The method for manufacturing a metal mask for vapor deposition as described in claim 1, comprising: Prepare a metal mask substrate for vapor deposition, which has a surface for forming a first opening facing a vapor deposition source in the vapor deposition apparatus, and a back surface located on the opposite side of the surface and for forming a second opening smaller than the first opening. A resin layer is formed on the back side; By wet etching the metal mask substrate for vapor deposition from the surface, a through hole with an inverted frustum shape is formed, thereby forming the first opening on the surface and the second opening on the back side; An antifouling layer containing fluorine compounds is formed on the surface and on the inner wall surface defining the through hole; After the antifouling layer is formed, the metal mask substrate for vapor deposition and the resin layer are exposed to ultraviolet light, thereby reducing the adhesion of the resin layer to the metal mask substrate for vapor deposition. as well as The resin layer with reduced adhesion is peeled off from the metal mask substrate for vapor deposition.

11. The method for manufacturing a metal mask for vapor deposition according to claim 10, wherein, The resin layer is formed by a UV-curable adhesive.

Images