CN115537720B - Evaporation mask - Google Patents

Abstract

The invention provides a vapor deposition mask which suppresses deformation generated in a mask pattern, the vapor deposition mask comprises a mask part with a plurality of opening parts, a holding frame for holding the mask part and a connecting part for connecting the mask part and the holding frame, wherein the connecting part comprises a1 st part contacted with the mask part in a mode of having a1 st film thickness and a2 nd part contacted with the mask part in a mode of having a2 nd film thickness thinner than the 1 st film thickness. The 2 nd portion may be located further inside the mask portion than the 1 st portion.

Description

Evaporation mask

Technical Field

The present invention relates to an evaporation mask.

Background technique

Generally, in the process of manufacturing an organic EL display device, a vacuum evaporation method is used to form a layer (organic EL layer) composed of an organic EL material. In the vacuum evaporation method, an evaporation mask is brought close to a substrate to be processed, and the organic EL material is evaporated on the substrate to be processed through the evaporation mask. The evaporation mask has a plurality of openings. The organic EL material reaches the substrate to be processed through the plurality of openings, so that the organic EL layer can be selectively formed at positions corresponding to the plurality of openings.

Vapor deposition masks are divided into fine metal masks (FMM) that use etching technology to form an opening pattern and electroforming masks (EFM) that use electroforming (electroforming) technology to form an opening pattern. For example, Patent Document 1 discloses a method of forming a mask portion having a high-precision opening pattern using electroforming technology and fixing the formed mask portion to a frame portion using electroforming technology.

Prior art literature

Patent Literature

Patent document 1: Japanese Patent Application Publication No. 2017-210633.

Summary of the invention

Problems to be solved by the invention

In the above-mentioned prior art, a mask pattern (electroforming layer) is formed on a master mold composed of a metal plate, a frame is bonded to the mask pattern, and then the frame and the mask pattern are connected via a metal layer. Then, the master mold is peeled off from the mask pattern, thereby completing the evaporation mask in which the frame and the mask pattern are connected via the metal layer. However, when the master mold is peeled off from the mask pattern, a large vertical stress is sometimes generated near the area where the thin film mask pattern contacts the metal layer (i.e., near the edge of the metal layer), and there is a problem of deformation in the mask pattern due to the vertical stress. The deformation generated in the mask pattern may cause the misalignment of the opening (evaporation hole) provided in the mask pattern, thereby reducing the evaporation accuracy.

One of the objects of one embodiment of the present invention is to provide a vapor deposition mask in which deformation occurring in a mask pattern is suppressed.

One of the objects of one embodiment of the present invention is to suppress deformation of the mask portion due to peeling of the mother mold.

Technical solutions to the problem

A vapor deposition mask according to one embodiment of the present invention includes: a mask portion having a plurality of openings; a holding frame for holding the mask portion; and a connecting portion connecting the mask portion and the holding frame, the connecting portion including: a first portion in contact with the mask portion in a manner having a first film thickness; and a second portion in contact with the mask portion in a manner having a second film thickness that is thinner than the first film thickness.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing the structure of a vapor deposition mask according to a first embodiment.

FIG. 2 is a cross-sectional view showing the structure of the vapor deposition mask according to the first embodiment.

FIG. 3A is a plan view showing an enlarged structure of a portion of the vapor deposition mask according to the first embodiment.

Fig. 3B is a cross-sectional view showing the structure of Fig. 3A cut along line B-B'.

FIG. 4 is a cross-sectional view showing the method for manufacturing the vapor deposition mask according to the first embodiment.

FIG. 5 is a cross-sectional view showing the method for manufacturing the vapor deposition mask according to the first embodiment.

FIG. 6 is a cross-sectional view showing the method for manufacturing the vapor deposition mask according to the first embodiment.

FIG. 7 is a cross-sectional view showing the method for manufacturing the vapor deposition mask according to the first embodiment.

FIG. 8 is a cross-sectional view showing the method for manufacturing the vapor deposition mask according to the first embodiment.

FIG. 9 is a cross-sectional view showing the method for manufacturing the vapor deposition mask according to the first embodiment.

FIG. 10 is a cross-sectional view showing the method for manufacturing the vapor deposition mask according to the first embodiment.

FIG. 11 is a cross-sectional view showing the method for manufacturing the vapor deposition mask according to the first embodiment.

FIG. 12 is a cross-sectional view showing the method for manufacturing the vapor deposition mask according to the first embodiment.

FIG. 13 is a cross-sectional view showing the method for manufacturing the vapor deposition mask according to the first embodiment.

FIG. 14 is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to Modification 1 of the first embodiment.

FIG. 15 is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to Modification 1 of the first embodiment.

FIG. 16 is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to Modification 2 of the first embodiment.

FIG. 17 is a cross-sectional view showing a method for manufacturing a vapor deposition mask according to Modification 2 of the first embodiment.

FIG. 18 is a plan view showing the structure of a vapor deposition mask according to the second embodiment.

FIG. 19 is a cross-sectional view showing the structure of a vapor deposition mask according to the second embodiment.

Description of Reference Numerals

100, 100A…evaporation mask, 110…mask portion, 111…opening portion, 112…non-opening portion, 115…panel area, 120…holding frame, 130…connecting portion, 130a, 130b, 130c…metal layer, 131…first portion, 132…second portion, 200…substrate, 210…seed layer, 220, 240, 242, 246…resist pattern.

Detailed ways

Hereinafter, the embodiments of the present invention will be described with reference to the accompanying drawings, etc. In addition, the present invention can be implemented in various ways within the scope of the main purpose thereof, and should not be interpreted in a limited manner to the contents of the embodiments illustrated below. For thickness, shape, etc., there are schematic representations, but this is only an example and does not limit the interpretation of the present invention. In this specification and each figure, the same reference numerals are marked for elements having the same functions as those described in the existing drawings, and repeated descriptions are omitted.

Within the scope of this specification and claims, when expressing the manner in which another structure is arranged on a certain structure, when it is simply expressed as "on...", unless specifically prohibited, it includes two situations: a situation in which another structure is arranged directly above the certain structure in a manner of contacting the certain structure, and a situation in which another structure is arranged above the certain structure with another structure in between.

In this specification, expressions such as "α includes A, B or C", "α includes any one of A, B and C", and "α includes one selected from A, B and C" do not exclude the case where α includes multiple combinations of A to C unless otherwise specified. Furthermore, these expressions do not exclude the case where α includes other elements.

<First Embodiment>

[Structure of Vapor Deposition Mask]

FIG. 1 is a top view showing the structure of a vapor deposition mask 100 according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view showing the structure of a vapor deposition mask 100 according to a first embodiment of the present invention. Specifically, the cross-sectional view shown in FIG. 2 shows a cross section along the line segment A-A' of FIG. 1 . As shown in FIGS. 1 and 2 , the vapor deposition mask 100 has a thin film-like mask portion 110 formed by electroforming (electroforming), a holding frame 120 for holding the mask portion 110, and a connecting portion 130 for connecting the mask portion 110 and the holding frame 120.

The mask portion 110 has a plurality of panel regions 115. When the organic EL material is evaporated, the evaporated substrate (not shown) is arranged in such a way that the display region of the organic EL display device overlaps with each panel region 115. In each panel region 115, a plurality of openings 111 are provided in accordance with the pixel pitch of the organic EL display device. The area other than the openings 111 of the mask portion 110 is referred to as a non-opening portion 112. The non-opening portion 112 is an area surrounding each opening 111. The non-opening portion 112 in each panel region 115 corresponds to a portion for shielding the evaporated material.

During evaporation, the evaporation mask 100 and the evaporation substrate are aligned in such a manner that the evaporation region (region where a thin film is to be formed) of the evaporation substrate overlaps with the opening 111, and the non-evaporation region of the evaporation substrate overlaps with the non-opening 112. The vapor of the evaporation material reaches the evaporation substrate through the opening 111, and the evaporation material is deposited in the evaporation region to form a thin film.

The holding frame 120 is provided at the periphery of the mask portion 110 so as to surround the plurality of panel regions 115 of the mask portion 110 when viewed from above. That is, the holding frame 120 functions as a component for holding the thin film-shaped mask portion 110. In addition, in FIG. 1 , the holding frame 120 is provided only at the periphery of the mask portion 110. However, the present invention is not limited to this example, and the holding frame 120 may also be provided in a grid shape.

The connection portion 130 is a component that connects the mask portion 110 and the holding frame 120. The evaporation mask 100 of this embodiment connects the mask portion 110 and the holding frame 120 via the connection portion 130. That is, as shown in FIG. 2 , the mask portion 110 and the holding frame 120 are not directly connected. In this embodiment, the portion of the connection portion 130 that contacts the mask portion 110 has at least two or more portions with relatively different film thicknesses. This will be described later.

In the above structure, the mask portion 110 is composed of a thin film plating layer. The mask portion 110 of the present embodiment is a thin film formed by electroplating. The thickness d1 of the mask portion 110 is, for example, 3 μm or more and 20 μm or less (preferably 5 μm or more and 10 μm or less). In the present embodiment, the thickness of the mask portion 110 is 5 μm. The holding frame 120 is composed of, for example, an alloy such as invar. Invar has a small thermal expansion coefficient at room temperature, so it has the advantage that it is not easy to generate stress on the mask portion 110 even if it is placed in an environment where the temperature changes after the evaporation process. The thickness d2 of the holding frame 120 is, for example, 0.5 mm or more and 1.5 mm or less (preferably 0.8 mm or more and 1.2 mm or less). In the present embodiment, the thickness of the holding frame 120 is 1 mm. In addition, although not specifically shown in FIG. 2 , the holding frame 120 can be composed of a single-layer structure or a stacked structure in which thin plate materials are stacked.

In the present embodiment, as the metal material constituting the mask portion 110, the retaining frame 120 and the connecting portion 130, Invar alloy is used. Compared with nickel and the like, the thermal expansion coefficient of Invar alloy at room temperature and the temperature in the formation process of the organic EL element is smaller, and the thermal expansion coefficient of glass is close. Therefore, by using Invar alloy as the structural material of the evaporation mask 100, the influence of thermal expansion between the mask portion 110 and the glass substrate can be suppressed in the manufacturing process of the evaporation mask 100 described later. In addition, during evaporation, there is also an advantage that the deviation caused by thermal expansion between the evaporation mask and the substrate to be evaporated (conventionally, a glass substrate) is small, and the position accuracy of evaporation is improved. However, it is not limited to this example, as long as it is a material with a coefficient close to the thermal expansion coefficient of glass, other materials other than Invar alloy can also be used. In addition, the retaining frame 120 can also be composed of a metal material different from the mask portion 110 and the connecting portion 130.

[Structure of the connection portion 130]

FIG3A is a top view showing a structure in which a portion of the vapor deposition mask 100 of the first embodiment is enlarged. Specifically, FIG3A is equivalent to an enlarged top view in which the region surrounded by the frame line 10 in FIG1 is enlarged. FIG3B is a cross-sectional view showing the structure after FIG3A is cut along the line B-B'. In FIG3A, for the sake of convenience of explanation, only the metal layer 130b described later is hatched.

As shown in Fig. 3A and Fig. 3B, the connection part 130 of the present embodiment is composed of a metal layer 130a and a metal layer 130b. The metal layer 130b is stacked on the metal layer 130a. More specifically, the metal layer 130b is provided in a manner covering the metal layer 130a. In the present embodiment, the metal layer 130a and the metal layer 130b are composed of the same metal layer, so that, in essence, the structure in which the metal layer 130a and the metal layer 130b are integrated functions as the connection part 130. However, it is not limited to this example, and the metal layer 130a and the metal 130b may also be composed of different metal layers.

As shown in FIG. 3B , the connection portion 130 includes: a first portion 131 connected to the mask portion 110 via a metal layer 130a; and a second portion 132 connected to the mask portion 110 via a metal layer 130b. Specifically, the first portion 131 is composed of a laminated structure of the metal layer 130a and the metal layer 130b, and the second portion 132 is composed of a single-layer structure of the metal layer 130b. In other words, the connection portion 130 includes: the first portion 131 in contact with the mask portion 110 in a manner having a first film thickness (the total film thickness of the metal layer 130a and the film thickness of the metal layer 130b); and the second portion 132 in contact with the mask portion 110 in a manner having a second film thickness (the film thickness of the metal layer 130b) thinner than the first film thickness. On the other hand, as shown in FIG. 3B , the connection portion 130 is connected to the side surface of the holding frame 120 via the metal layer 130a. Specifically, the connection portion 130 is in contact with the side surface of the holding frame 120 so as to have the above-mentioned first film thickness.

In the present embodiment, the portion of the connection portion 130 that contacts the mask portion 110 is composed of a plurality of portions having different film thicknesses. Specifically, the first portion 131 is located on the side close to the end of the mask portion 110, and the second portion 132 is located on the inner side of the mask portion 110 (the side close to the panel region 115) than the first portion 131. Thus, in the present embodiment, the end of the connection portion 130 is gradually thinned as it goes to the inner side of the mask portion 110. In other words, in the present embodiment, a metal layer 130b having a film thickness thinner than the metal layer 130a is provided so as to cover the boundary between the metal layer 130a and the mask portion 110 when viewed from above.

That is, the physical strength of the vapor deposition mask 100 is highest at the holding frame 120 and lowest at the mask portion 110, with the connection portion 130 located in the middle. At this time, the boundary between the holding frame 120 and the connection portion 130, and the boundary between the connection portion 130 and the mask portion 110, are very easy to break due to the large difference in strength between the components on one side and the other side, and are particularly noticeable at the boundary between the connection portion 130 and the mask portion 110.

As described above, in this embodiment, when viewed from above, the metal layer 130b is extended from the end of the metal layer 130a toward one side of the panel region 115, thereby realizing a structure in which the film thickness of the connection portion 130 gradually becomes thinner as it goes toward the inner side of the mask portion 110. By adopting such a structure, the vertical stress generated in the mask portion 110 near the end of the metal layer 130a can be alleviated, and the deformation generated in the mask portion 110 can be reduced. In other words, the deformation of the mask portion 110 caused by the peeling of the master mold during the manufacture of the vapor deposition mask 100 can be suppressed.

3B , the thickness of the metal layer 130b may be set to be 50% to 100% of the thickness of the metal layer constituting the mask portion 110. For example, when the thickness of the mask portion 110 is 5 μm, the thickness of the metal layer 130b may be set to be 2.5 μm to 5 μm.

In addition, in the present embodiment, the length (X) of the second portion 132 is set to be 10 μm or more (preferably 20 μm or more, and more preferably 30 μm or more). According to the knowledge of the inventors of the present invention, the longer the length of the second portion 132 is, the lower the vertical stress is. However, when the second portion 132 exceeds 30 μm, no change in the vertical stress is observed. That is, the vertical stress can be sufficiently reduced as long as the length of the second portion 132 is 30 μm or more.

[Method of Manufacturing Vapor Deposition Mask 100]

The method for manufacturing the vapor deposition mask 100 according to the present embodiment will be described in detail with reference to the drawings. Fig. 4 to Fig. 12 are views showing the method for manufacturing the vapor deposition mask 100 according to the first embodiment of the present invention.

First, as shown in Fig. 4, a seed layer 210 and a resist pattern 220 are formed on a substrate 200. In this embodiment, a glass substrate is used as the substrate 200. However, the present invention is not limited to this example, and a metal substrate or a ceramic substrate may be used as the substrate 200.

The seed layer 210 is a metal layer provided for growing the plating layer. In the present embodiment, since a nickel alloy (specifically, Invar alloy) is used as the material of the plating layer 230a described later, a metal layer containing copper (Cu) is used as the seed layer 210. However, this example is not limited thereto, and other metal layers may also be used as long as they are metal layers that can function as a seed layer. As described above, when a metal substrate is used as the substrate 200, since the plating layer 230a is grown directly on the surface of the substrate 200, the seed layer 210 may not be provided.

The seed layer 210 may be formed by sputtering or CVD (Chemical Vapor Deposition). The thickness of the seed layer 210 may be sufficient as long as the conductivity required for the growth of the plating layer 230 described later is ensured. For example, the thickness of the seed layer 210 may be in the range of 50 nm to 500 nm.

The resist pattern 220 is formed by applying a photosensitive resin material on the seed layer 210, and then performing an exposure process and a development (etching) process. The region where the resist pattern 220 is formed corresponds to the region where the plurality of openings 111 of the mask portion 110 shown in FIGS. 1 and 2 are provided. The resist pattern 220 may also be formed using a dry film resist (DFR).

Next, as shown in FIG. 5 , a plating layer 230 is formed in an area where the resist pattern 220 is not configured. That is, the area where the plating layer 230 is formed corresponds to the area where the non-opening portion 112 of the mask portion 110 shown in FIGS. 1 and 2 is provided. In this embodiment, before the formation of the plating layer 230, the surface of the seed layer 210 is pre-treated with a release agent. As a release agent, for example, "Nikkanok" (product name, registered trademark) of Nippon Chemical Industry Co., Ltd. can be used.

In the present embodiment, the plating layer 230 is a metal layer made of a nickel alloy (specifically, Invar alloy). In the present embodiment, electroplating is performed by energizing the seed layer 210 in an aqueous solution of metal ions containing a nickel alloy. When the seed layer 210 is energized, a plating layer 230 is formed on the surface of the seed layer 210. The thickness of the plating layer 230 can be adjusted by controlling the time of electroplating. In the present embodiment, the thickness of the plating layer 230 is adjusted in a range of 3 μm to 20 μm (preferably 5 μm to 10 μm). Specifically, in the present embodiment, the thickness of the plating layer 230 is 5 μm. In the present embodiment, an example of forming the plating layer 230 with Invar alloy is shown, but it is not limited to this example, and other metal materials can also be used as long as they are materials that can be used in electroplating. The technology of using electroplating in this way to make a shape faithful to the master mold (in this case, the resist pattern) is called electrocasting (electrocasting).

When the plating layer 230 is formed, the resist pattern 220 is removed as shown in FIG6. By removing the resist pattern 220, a mask pattern composed of the plating layer 230 is formed. The mask pattern composed of the plating layer 230 corresponds to the non-opening portion 112 (i.e., the shielding portion that shields the vapor deposition material) shown in FIGS. 1 and 2. The area formed by removing the resist pattern 220 corresponds to the opening portion 111 shown in FIGS. 1 and 2. Therefore, in the state shown in FIG6, a mask pattern that functions as the mask portion 110 is finally formed on the substrate 200. In FIG6, the area that functions as the mask pattern composed of the opening portion 111 and the non-opening portion 112 corresponds to the panel area 115.

Next, as shown in FIG7 , a resist pattern 240 is formed on the mask portion 110. The resist pattern 240 is formed by applying a photosensitive resin material on the mask portion 110 and then performing an exposure process and a development (etching) process. The region where the resist pattern 240 is formed is a region other than the region where the metal layer 130a shown in FIG3B is provided and the region where the holding frame 120 is arranged. The resist pattern 240 can also be formed using a dry film resist (DFR).

Next, as shown in FIG8 , a holding frame 120 is arranged on a part of the non-opening portion 112 (a portion not used as the mask portion 110). The holding frame 120 is bonded to the non-opening portion 112 by the bonding force of an adhesive layer (e.g., an unexposed dry film resist) not shown in the figure. The holding frame 120 is arranged so as to surround the mask portion 110 as shown in FIG1 . In addition, a resist pattern 242 that functions as a mask is pre-set on the upper surface of the holding frame 120. The resist pattern 242 can also be formed using a dry film resist (DFR).

Next, as shown in FIG. 9 , a metal layer 130 a is formed in an area where the resist patterns 240 and 242 are not configured. The metal layer 130 a is formed using electroplating. Specifically, the metal layer 130 a is selectively formed in an area where the resist patterns 240 and 242 are not configured, using the holding frame 120, the non-opening portion 112, and the seed layer 210 as a seed layer. Therefore, as shown in FIG. 9 , the metal layer 130 a is formed from the side of the holding frame 120 across the mask portion 110.

In this embodiment, the metal layer 130a is continuously formed from the side of the holding frame 120 to the mask portion 110. Thus, the holding frame 120 and the mask portion 110 can be connected via the metal layer 130a. The opening 111 provided in the portion of the mask portion 110 overlapping with the metal layer 130a has the function of physically isolating the mask portion 110 from the holding frame 120 and improving the adhesion between the mask portion 110 and the metal layer 130a.

In this embodiment, the metal layer 130a is formed of a plating layer (metal layer) made of a nickel alloy (specifically, Invar alloy). In this embodiment, the thickness of the metal layer 130a is adjusted within a range of 50 μm to 200 μm. In this embodiment, an example of forming the metal layer 130a using Invar alloy is shown, but the present invention is not limited to this example, and other metal materials can be used as long as they can be used in electroplating.

When the first metal layer 130a is formed, the resist patterns 240 and 242 are removed. Thereafter, as shown in FIG. 10 , a new resist pattern 244 is formed. The resist pattern 244 is formed by applying a photosensitive resin material, and then performing an exposure process and a development (etching) process. The region where the resist pattern 244 is formed is a region other than the region where the metal layer 130b shown in FIG. 3B is provided. Specifically, it is on a portion of the mask portion 110 and on the holding frame 120. The resist pattern 244 can also be formed using a dry film resist (DFR).

At this time, as shown in Fig. 10, a space of distance X is left between the end of the metal layer 130a and the end of the resist pattern 244. This space is a region for forming the second portion 132 shown in Fig. 3B. The distance X may be 10 μm or more (preferably 20 μm or more, more preferably 30 μm or more).

Next, as shown in FIG. 11 , a metal layer 130 b is formed in an area where the resist pattern 244 is not configured. The metal layer 130 b is formed using electroplating. Specifically, the metal layer 130 b is selectively formed using the metal layer 130 a and a portion of the non-opening portion 112 (an area not covered by the resist 244) as a seed layer. Therefore, as shown in FIG. 11 , the metal layer 130 b is formed in a manner covering the metal layer 130 a. In addition, the end of the metal layer 130 b is directly in contact with the non-opening portion 112. Thus, a portion corresponding to the second portion 132 described using FIG. 3B is formed.

In this embodiment, the metal layer 130b is formed of a plating layer (metal layer) made of a nickel alloy (specifically, Invar alloy). In this embodiment, the thickness of the metal layer 130a is adjusted within a range of 2.5 μm to 5 μm. In this embodiment, an example of forming the metal layer 130b using Invar alloy is shown, but the present invention is not limited to this example, and other metal materials can also be used as long as they can be used in electroplating.

When the metal layer 130b is formed, as shown in FIG12, after removing the resist pattern 244, the substrate 200 is removed. Specifically, after the holding frame 120 is fixed by adsorption or the like, the substrate 200 is mechanically peeled off from the mask portion 110, the holding frame 120, and the connecting portion 130, thereby removing the substrate 200. At this time, the seed layer 210 and a portion of the mask portion 110 (the non-opening portion 112 overlapping the holding frame 120) are removed together with the substrate 200.

In this embodiment, the metal layer 130b is provided so as to cover the end of the metal layer 130a as shown in the area surrounded by the frame line 20. Therefore, it is possible to reduce the vertical stress generated in the area surrounded by the frame line 20 when the substrate 200 is peeled off.

After the above manufacturing process, the vapor deposition mask 100 having the cross-sectional structure shown in FIG13 is completed. As shown in FIG13, the vapor deposition mask 100 of this embodiment has a structure in which a thin film mask portion 110 is connected to a holding frame 120 via a connecting portion 130. At this time, the connecting portion 130 includes a first portion 131 composed of a stacked structure of a metal layer 130a and a metal layer 130b and a second portion 132 composed only of the metal layer 130b. That is, in this embodiment, a portion having a thinner film thickness than other portions is provided at the end of the connecting portion 130 on the mask portion 110 side.

In this embodiment, by adopting the above-mentioned structure, when peeling the substrate 200, the vertical stress generated in the mask part 110 near the end of the connection part 130 can be relieved, and the deformation of the mask part 110 caused by the peeling of the substrate 200 can be suppressed. In this way, according to this embodiment, a vapor deposition mask in which deformation generated in the mask pattern is suppressed can be provided.

<Modification 1>

In the first embodiment, an example of forming the connection portion 130 using metal layers 130a and 130b having different film thicknesses is illustrated, but the present invention is not limited to this example, and a single metal layer may be used to form the connection portion 130. In this modification, an example of forming the connection portion 130 using a single plating layer is described. For the same elements as those in the first embodiment in the drawings used in the description, the same reference numerals are used, and detailed descriptions are omitted.

14 and 15 are cross-sectional views showing the structure of a vapor deposition mask 100 according to Modification 1 of the first embodiment of the present invention.

The state shown in FIG. 9 is obtained in the same manner as in the first embodiment. That is, the connection portion 130 is formed between the mask portion 110 and the holding frame 120 by electroplating. When the connection portion 130 is formed, the resist pattern 240 is removed, and then a resist pattern 246 is formed as shown in FIG. 14. The resist pattern 246 is formed by applying a photosensitive resin material and performing an exposure process and a development (etching) process. The region where the resist pattern 246 is formed is a region other than the region corresponding to the second portion 132 shown in FIG. 3B.

After the resist pattern 246 is formed, the end of the connection portion 130 is etched using the resist pattern 246 as a mask to partially thin the end of the connection portion 130 (the end on the side close to the mask portion 110). This process is a so-called half-etching process. When the half-etching process is completed, the resist pattern 246 is removed to obtain the state shown in FIG. 15.

As shown in FIG. 15 , the connection portion 130c of the first modification includes a first portion 131 formed of a single metal layer (plating layer) and in contact with the mask portion 110 in a manner having a first film thickness, and a second portion 132 in contact with the mask portion 110 in a manner having a second film thickness thinner than the first film thickness. Thus, the connection portion 130c of the first modification has a structure in which the film thickness gradually becomes thinner toward the inside of the mask portion 110, as in the first embodiment. Therefore, the vertical stress generated in the mask portion 110 near the end of the connection portion 130c can be alleviated, and the deformation generated in the mask portion 110 can be reduced.

<Modification 2>

In the first embodiment, an example is shown in which the resist pattern 240 is removed after the metal layer 130a is formed, and a new resist pattern 244 is formed. However, the present invention is not limited to this example, and the resist pattern 240 used in the formation of the metal layer 130a can be reused in the process shown in FIG. 10. In this modification, an example of forming the metal layer 130b using the resist pattern 240 is described. For the same elements as those in the first embodiment in the drawings used in the description, the same reference numerals are used, and detailed descriptions are omitted.

16 and 17 are cross-sectional views showing the structure of a vapor deposition mask 100 according to Modification 2 of the first embodiment of the present invention.

When the state shown in FIG. 9 is obtained in the same manner as in the first embodiment, the resist pattern 240 is etched so that the end of the resist pattern 240 is laterally retreated by a distance X. The retreat amount obtained by the etching process is the length (X) corresponding to the second portion 132 shown in FIG. 3B. Such an etching process performed on the entire film formed at one time is called an etch-back process. As an etch-back process, for example, a dry etching process in an oxygen atmosphere is used. At this time, the end of the resist pattern 242 set on the retaining frame 120 is also retreated in the same manner, but there is no significant effect on the performance as a vapor deposition mask.

Next, the metal layer 130b is formed by electroplating using the retreated resist patterns 240 and 242. When the metal layer 130b is formed, the resist patterns 240 and 242 are removed to obtain the state shown in FIG17. According to this modification 2, it is not necessary to form a new resist pattern 244 when forming the metal layer 130b, and the manufacturing process can be simplified.

(Variant 3)

In the first embodiment, an example is shown in which two metal layers 130a and 130b are used to form the connection portion 130. Three or more metal layers may be used to form the connection portion 130. For example, the metal layer 130a may be formed of two or more metal layers, the metal layer 130b may be formed of a single metal layer, or the metal layer 130a and the metal layer 130b may be formed of a plurality of metal layers.

In addition, when more than three metal layers are used, the film thickness of the connection portion 130 may be changed in three or more stages. For example, after obtaining the state shown in FIG. 11 , the resist pattern 244 is removed to form a new resist pattern. At this time, the new resist pattern is configured so that a portion of the metal layer 130 b and the non-opening portion 112 are exposed. Afterwards, the third electroplating may be performed using the new resist pattern as a mask to form a third metal layer covering the metal layer 130 b.

By using three or more metal layers (plating layers) as in this modification, the film thickness of the connection portion 130 can be changed in three or more stages, and the change in the film thickness at the end of the connection portion 130 (the end on the mask portion 110 side) can be further slowed down. As a result, the performance of alleviating the vertical stress generated when the substrate 200 is peeled off is further improved.

<Second Embodiment>

In this embodiment, a vapor deposition mask 100A having a structure different from that of the first embodiment is described. FIG. 18 is a top view showing the structure of the vapor deposition mask 100A of the second embodiment of the present invention. FIG. 19 is a cross-sectional view showing the structure of the vapor deposition mask 100A of the second embodiment of the present invention. The vapor deposition mask 100A of this embodiment has the same structure as the vapor deposition mask 100 of the first embodiment except that the arrangement of the holding frame 120 and the connecting portion 130 is different. Therefore, the same reference numerals are used for the same elements as those of the first embodiment, and detailed descriptions are omitted.

As shown in FIGS. 18 and 19 , the vapor deposition mask 100A has a holding frame 120 arranged in a grid shape on the mask portion 110. That is, the mask portion 110 is supported by the holding frame 120 arranged in a grid shape. As in the first embodiment, the mask portion 110 is connected to the holding frame 120 via a connecting portion 130. In addition, as shown in FIG. 19 , the connecting portion 130 is composed of a metal layer 130a and a metal layer 130b, and the film thickness of the end portion on the side close to the panel region 115 is thinner than that of other portions. The specific structure of the connecting portion 130 is the same as that of the first embodiment.

As described above, in the present embodiment, a lattice-shaped metal member is used instead of a rectangular metal member as the holding frame 120. Therefore, the vapor deposition mask 100A of the present embodiment can support the mask portion 110 more stably than the first embodiment.

As embodiments of the present invention, the above-mentioned embodiments (including various modified examples) can be appropriately combined and implemented as long as they are not contradictory to each other. Based on each embodiment, those skilled in the art can appropriately add, delete or design the embodiment after the constituent elements are added, deleted or the embodiment after the conditions are changed, or the embodiment after the process is added, omitted or the conditions are changed, as long as they conform to the main purpose of the present invention, they are also included in the scope of the present invention.

Furthermore, regarding other effects different from the effects obtained by the above-mentioned embodiments, effects that are clear from the description of this specification or effects that can be easily predicted by practitioners in this industry are of course also interpreted as being obtained by the present invention.

Claims (8)

1. An evaporation mask, comprising:

a mask portion having a plurality of openings;

a holding frame for holding the mask portion; and

A connecting portion connecting the mask portion and the holding frame,

The connection portion includes: a 1 st portion contacting the mask portion so as to have a 1 st film thickness; and a2 nd portion contacting the mask portion so as to have a2 nd film thickness smaller than the 1 st film thickness,

The connection portion is composed of a1 st metal layer and a2 nd metal layer laminated on the 1 st metal layer,

The 2 nd metal layer extends from an end of the 1 st metal layer to an inner side of the mask portion in a plan view,

The 1 st part is formed by a laminated structure of the 1 st metal layer and the 2 nd metal layer, and is in contact with the mask part so as to have a total film thickness of the 1 st metal layer and the 2 nd metal layer,

The 2 nd portion is formed of the 2 nd metal layer and is in contact with the mask portion so as to have a film thickness of the 2 nd metal layer.

2. The vapor deposition mask according to claim 1, wherein:

The 2 nd part is located further inside the mask part than the 1 st part.

3. The vapor deposition mask according to claim 1, wherein:

The width of the 2 nd portion is 10 μm or more in a plan view.

4. The vapor deposition mask according to claim 1, wherein:

the connection portion is in contact with a side surface of the holding frame so as to have the 1 st film thickness.

5. The vapor deposition mask according to claim 1, wherein:

the 1 st metal layer and the 2 nd metal layer are plating layers.

6. The vapor deposition mask according to claim 1, wherein:

the 1 st metal layer and the 2 nd metal layer are the same metal layer.

7. The vapor deposition mask according to claim 1, wherein:

the mask portion is composed of a plating layer.

8. The vapor deposition mask according to claim 1, wherein:

The mask portion is connected to the holding frame via the connection portion.