JP2006152396A - Method for manufacturing metal mask, mask of artwork master for electroforming and artwork master - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a metal mask for vapor deposition suitable for forming a light-emitting layer of an organic EL display. <P>SOLUTION: An artwork master 25 for electroforming is provided with an approximately trapezoidal salient 22a having an inclined side wall which is made of a resist 22 placed on an electroconductive film 20 of a base substrate 19. The metal mask 35 is formed by steps of: depositing a desired metal 34 on the electroconductive film 20 along the inclined side wall of the approximately trapezoidal salient 22a made of the resist 22 in its height direction by using the artwork master 25 by an electroforming method; and then peeling the metal. Thereby, the metal mask 35 acquires an opening 35a having the inner side wall inclined. The light-emitting layer of a light-emitting organic material is formed into a uniform thickness on a substrate to be film-formed by the use of the metal mask by vapor deposition, because the metal mask does not form a shadow between an evaporation source for vaporizing the light-emitting organic material and the substrate to be film-formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a metal mask and an electroforming mask used for producing a metal mask suitable for use as an evaporation mask for performing highly accurate pattern deposition in an organic EL (Electro Luminescence) display or the like. The present invention relates to a method for manufacturing an original plate and a master original plate.

  Printing plate with openings in a predetermined printing pattern for printing solder cream to mount electronic components on a printed wiring board or printing conductive resin to form a dot pattern for a touch panel However, when a printed pattern is formed with high accuracy, a metal mask with little deformation of the plate itself is used.

FIG. 9 is an explanatory view of a conventional method for producing a metal mask formed by etching a metal plate.
First, as shown in FIG. 9A, a film of a positive type photoresist 102 is formed on the surface of a metal plate 101 which is a base material of a metal mask. At this time, the film of the photoresist 102 may be formed by attaching a dry film, or may be formed by applying a liquid photoresist and then curing it to a state where the surface is not sticky by pre-baking.
Next, as shown in FIG. 9B, an exposure photomask 103 on which a predetermined print pattern is formed is disposed on the upper surface of the photoresist 102 and exposed.

Next, as shown in FIG. 9C, the photoresist 102 exposed by exposure is developed. Thereby, the exposed portion of the photoresist 102 is removed, and the surface of the metal plate 101 is exposed.
Finally, as shown in FIG. 9D, the metal plate 101 is etched and processed by spraying a chemical solution from the printed pattern forming surface side by the photoresist 102. At this time, the pattern formed by remaining the photoresist 102 serves as a mask when the metal plate 101 is etched.

In this way, in the method of processing the metal plate 101 by etching with a chemical solution using the photoresist 102 formed on the metal plate 101 as a reference, as shown in FIG. 9D, not only the thickness direction of the metal plate 101 but also the surface. Etching is also performed in the direction, producing a so-called side etching 101a.
In the metal plate 101 in which the opening is formed by etching, the opening size on the resist 102 side which is an etching mask of the opening of the metal plate 101 and the opening size on the lower side shown in FIG. The size of the opening in the metal plate 101 varies greatly.

That is, although it can be formed with high accuracy up to the photomask 103 until the printing pattern is transferred and formed on the photoresist 102 shown in FIGS. 9A to 9C, the processing accuracy is improved by the side etching 101a by the etching process with a chemical solution. Will vary.
In other words, as shown in FIG. 9E, it is ideal that the inner wall of the opening of the metal plate 101 is formed so as to substantially follow the printed pattern by the photoresist 102. Even if the printed pattern is formed with high accuracy, there is a disadvantage that the advantage cannot be utilized.

In contrast to the inconvenience associated with the use of the above-described wet etching method, a metal mask manufacturing method by dry processing is conceivable. For example, there is a laser method as a method of forming a plurality of holes in a metal plate. In this method, irradiation light from a laser is two-dimensionally moved on a fixed metal plate, and the metal itself is evaporated by the thermal energy to produce a metal mask having a predetermined aperture pattern. In this method, side etching does not occur, but the metal plate is affected by the heat accompanying laser irradiation, causing warpage and undulation, resulting in poor position accuracy of the opening portion. On the other hand, the plate thickness exceeding 10 μm has a disadvantage that it takes a long processing time and is difficult to adopt from the viewpoint of cost.
In addition, it is conceivable to adopt a dry etching method used in the manufacture of semiconductors. In general, however, a metal mask for performing highly accurate pattern deposition in an organic EL display or the like requires a plate thickness of 10 μm or more and is not large. This method is disadvantageous in that it is difficult to adopt this method in terms of apparatus, processing time, and cost because it requires 300 × 300 mm or more.

In contrast to the above method, an electroforming method is known as a method for producing a highly accurate metal mask.
As shown in FIG. 10A, a metal mask manufacturing method by electroforming is performed by first forming a metal film on one surface of a base substrate 109 made of a non-conductive material such as glass by sputtering or the like to impart conductivity. Then, a mask opening pattern of the photoresist 102 is transferred and formed on the conductive film 107 with high accuracy. Next, a power source is connected to the conductive film 107 exposed in the plating solution in a plating solution on the conductive film 107 to deposit nickel or a nickel alloy to a required thickness as shown in FIG. 10B. . Finally, as shown in FIG. 10C, the deposited metal film 105 is peeled off to form a metal mask 106.
Note that a metal plate may be used for the substrate instead of the base substrate 109 over which the conductive film 107 is formed.

In the metal mask manufacturing method described above, a printed pattern of the photoresist 102 transferred and formed on the base substrate 109 is used as a matrix, a metal is deposited on the conductive film 107 by electroplating, and the metal is peeled off to obtain a product. Since it uses a plating bath, it can be produced not only to a relatively large size but also to a molding process with good dimensional accuracy because it is molded on a mother die by a non-heating process.
For this reason, in the manufacturing method of the metal mask 106 in which not only the positional accuracy of the printed pattern but also the shape of each pattern itself must be suppressed within a few μm, the matrix on which the metal is deposited is manufactured with sufficient accuracy. It is extremely important to do this.

In the manufacturing process of the master mold, in a highly clean environment with minimal dust, after applying the resist, exposure and development are performed using a photomask patterned with high precision, and the pattern is transferred and formed. Is done.
The photomask used to make a mask with an aperture pattern that requires accuracy is not coated with a film-like mask, but a photoresist is applied to a blank mask in which a chromium film is deposited on synthetic glass, etc. Is directly drawn with high accuracy, and then a resist pattern is developed, a chromium film is etched and the resist is peeled off, and a predetermined pattern is transferred to the chromium film.

The photomask having a chrome film pattern (hereinafter referred to as a chrome mask) manufactured in this manner is formed with extremely high accuracy in the position and shape of the pattern to be formed, and is relatively dimensionally stable against temperature changes. There are but expensive.
For this reason, if a metal mask for work that is necessary for mass production is directly manufactured from a chrome mask, the chrome mask which is the source is damaged, and the pattern accuracy of the metal mask cannot be maintained and the lifetime of the chrome mask is shortened. Therefore, in practice, a minimum number of electroforming mask masters are produced from the chrome mask, and the required number of metal masks are produced from the electroforming mask master, thereby reducing the number of times the chrome mask is used. We try to ensure a long life.

On the other hand, when the metal mask for vapor deposition is a metal mask 106 shown in FIG. 11A, the inner wall of the opening is formed in a shape substantially perpendicular to the front and back surfaces 106-1 and 106-2. As a result, the shoulder of the outer peripheral edge of the vapor deposition material 111 formed on the film formation substrate 108 becomes gentle, and there is a disadvantage that it cannot be formed in a uniform thickness.
This is because the evaporated material flies not only in the straight direction but also in the oblique direction to the through hole 106a of the metal mask 106. At this time, the vapor deposition material incident on the through hole 106a from the oblique direction is the upper edge of the opening of the metal mask 106. When blocked by 106b, only a small amount of material is deposited on the film formation substrate 108 at the edge portion of the through hole 106a, and the formed thin film layer has a shape in which the central portion swells and the edge portion gradually decreases. It is.
When this metal mask 106 is used as an evaporation mask for an organic EL display or the like, unevenness in light emission occurs due to uneven thickness of the light emitting layer 111 made of a light emitting organic material.

That is, in the method of wet etching using the etching resist pattern formed on the metal plate in the example of FIG. 9, accurate pattern formation cannot be performed by side etching, but metal is deposited between the resist patterns by plating in the example of FIG. The shape accuracy of the metal mask produced by the electroforming method is extremely good, but in the conventional metal mask, the inner wall of the opening is formed substantially perpendicular to the front and back surfaces, so the film thickness Therefore, the metal mask cannot be used as it is for the production of a substrate such as an organic EL display.
For this reason, conventionally, various studies have been made in order to improve the non-uniformity of the film thickness during film formation in the production of a metal mask by electroforming (Patent Document 1 and Patent Document 2).
These Patent Document 1 and Patent Document 2 describe a method of preventing an obstacle in film formation due to the thickness of the mask by inclining the periphery of the opening portion of the mask.

In the method disclosed in Patent Document 1, a glass mask with a chromium film on which a hole pattern of a metal mask is formed is first applied with a photoresist on the chromium film side, and then the glass surface which is the opposite surface. Light is irradiated while the mask is tilted and rotated from the side, and the photoresist is exposed with an opening pattern of a chromium film. Next, a tapered resist pattern is formed by development, and finally, in this state, a predetermined metal is deposited on the chromium film by electroplating, and the deposited metal is peeled off from the glass mask, and the metal mask having an inclined side wall at the opening portion. It is what.
In this method, a metal mask having an inclined side wall at the opening is manufactured based on a single glass mask.

In addition, the method disclosed in Patent Document 2 forms a taper shape of the outward opening of the metal mask by making use of the wraparound property of the metal deposited by electroplating, or exposes the ultraviolet light transmittance. The photoresist pattern is formed by electroplating after forming a resist pattern having inclined sidewalls in such a manner that the photosensitive region is constricted in the depth direction of the photoresist.
JP 2002-105621 A (2nd page, FIG. 3) Japanese Patent Laying-Open No. 2003-45657 (second page, FIG. 4, FIG. 5, FIG. 7)

However, in contrast to the method of FIG. 9 and FIG. 10, the metal mask manufacturing method disclosed in Patent Document 1 and Patent Document 2 is provided with an inclination around the opening portion, so that the thickness is Although a substantially uniform film can be formed, in the method disclosed in Patent Document 1, in order to produce one metal mask used for work, a photoresist is applied to a glass mask with a pattern every time exposure, development, Since the plate-like metal having a desired shape is deposited by performing the electroplating process, problems such as dust, scratches or a lifetime on the glass mask due to these processes cannot be solved.
Further, in the method disclosed in Patent Document 2, the shape of the outer edge of the opening of the metal mask after plating varies depending on the deposition property of the deposited metal, the resist film thickness such as exposure, and the prebaking conditions, There is a problem that the accuracy of the parts deteriorates.

  In view of such points, the present invention makes use of the advantages of photolithography technology and electroforming, and when used for a deposition mask, a method for producing a metal mask that is highly accurate and hardly causes film thickness unevenness, and for producing the same, The present invention proposes a method for producing an electroforming mask master and a master original.

  In order to solve the above-described problems, a metal mask manufacturing method of the present invention is a metal mask manufactured based on an electroforming mask master, and a transfer pattern similar in a predetermined shape is formed on a first substrate coated with a resist. Development is performed by sequentially using a plurality of formed photomasks, followed by development to form a predetermined shape convex portion having an inclined side wall on the first substrate, and the first substrate has a predetermined shape convex portion forming side on the entire surface. 1 is formed, a metal is deposited on the upper surface of the first conductive film by plating, and a master original plate having a concave portion having a predetermined shape is formed from the interface between the deposited metal and the first conductive film, On the upper surface having conductivity of the second substrate, a convex portion substantially the same as the convex portion of the predetermined shape is formed of resin based on the concave portion of the master original plate, and the second substrate having the convex portion of the resin is formed from the master original plate. Exfoliate mask for electroforming On the second conductive film exposed on the electroforming mask original plate, and plating to a thickness where an opening having substantially the same side wall as the inclined side wall of the concave portion of the mask original plate is provided by plating. A film is deposited and formed, and the metal film is peeled off from the electroforming mask original plate.

  According to the method of manufacturing a metal mask of the present invention configured as described above, a predetermined shape convex portion having an inclined side wall made of a photoresist formed using a plurality of photomasks on a first substrate is formed as a matrix, Using a master original plate having a predetermined shape concave portion provided with an inclined inner side wall and a bottom surface made of metal deposited by electroplating, a predetermined shape convex portion having an inclined side wall made of resist is formed on the conductive upper surface of the second substrate. And producing a metal mask having a predetermined inclination on the side wall by depositing metal to the middle of the height of the convex portion of the predetermined shape of the electroforming mask original plate. Can do.

  In addition, according to the method for producing an electroforming mask precursor of the present invention, a similar transfer pattern having a predetermined shape is formed on a first substrate coated with a photoresist in an electroforming mask precursor produced based on a master precursor. A plurality of photomasks that are sequentially exposed and developed to form a predetermined-shaped convex portion having an inclined side wall on the first substrate, and a conductive film is formed on the entire surface of the first substrate on the predetermined-shaped convex portion forming side; And depositing a metal on the upper surface of the conductive film by plating, producing a master original plate having a predetermined shape recess from the interface with the conductive film, and depositing the deposited metal on the conductive upper surface of the second substrate. Then, an organic film resist is applied, and a predetermined shape concave portion of the master original plate is transferred to the formed organic film resist by applying a predetermined pressure to form a convex portion substantially the same as the predetermined shape convex portion with a resin. No. with convex part Peeling the substrate from the master plate precursor those produced.

  According to the method of manufacturing an electroforming mask master of the present invention configured as described above, a convex portion having a predetermined shape having an inclined side wall made of a photoresist formed using a plurality of photomasks on a first substrate is used as a matrix. An electroforming mask original is formed on a conductive upper surface of a second substrate using a master original having a concave portion with a predetermined shape provided with an inclined inner side wall and a bottom made of metal deposited and electroplated. The predetermined-shaped convex part which has the inclination side wall by can be formed.

The master master plate manufacturing method of the present invention has a substrate coated with a photoresist, sequentially exposed using a plurality of photomasks having a predetermined transfer pattern formed in a predetermined shape, developed, and has inclined sidewalls on the substrate. A convex portion is formed, a conductive film is formed on the entire surface of the substrate on the side where the predetermined convex portion is formed, a metal is deposited on the upper surface of the conductive film by plating, and the deposited metal is peeled from the conductive film to be predetermined. It was produced so as to have a shape recess.

  According to the manufacturing method of the master master of the present invention configured as described above, the master master is formed by using a plurality of photomasks on a substrate and having a convex portion having a predetermined shape having inclined side walls made of photoresist. Then, a metal master can be obtained by depositing metal on the surface of the mother die by electroplating to form a concave portion having a predetermined shape having an inclined inner side wall and a bottom surface.

  According to the method for producing a metal mask of the present invention, since it is a three-dimensional replication method in which a metal is deposited in a plating bath in accordance with the shape of an electroformed mask master, it is not easily affected by dust, and the dimensional accuracy between metal masks. In addition, when used as a vapor deposition mask, a metal mask that can be formed with high pattern accuracy and a uniform film thickness can be manufactured at low cost.

  In addition, according to the method for producing an electroformed mask original plate of the present invention, the convex portion corresponding to the concave portion of the master original plate can be formed by molding and curing with a resin such as a soft resist, and damage to the master original plate. Therefore, it is possible to produce the minimum necessary number of electroformed mask masters having the necessary and sufficient accuracy.

In addition, according to the method for producing a master original plate of the present invention, a photoresist having a three-dimensional shape convex portion having a desired inclined side wall using a plurality of photomasks is used as a matrix, and metal is deposited to a desired thickness by plating. Therefore, a master master plate having sufficient dimensional stability and strength and resistant to scratches and dust can be obtained. In addition, since the master master is a metal body, it is difficult to be affected by humidity and changes over time, and it can be stored easily. Based on this, a metal mask can be produced and used for repairing the product.
Then, a minimum number of electroforming mask original plates that maintain high dimensional accuracy and shape are prepared based on the master original plate, and work holes having open sidewalls that have substantially the same inclination as the master original plate based on the electroforming mask original plate. A desired number of metal masks can be produced.

  Hereinafter, an example of the best mode for carrying out the manufacturing method of the metal mask, the electroforming mask original plate, and the master original plate of the present invention will be described with reference to FIGS.

As described above, a metal mask for vapor deposition that is used to form a vapor deposition film on an organic EL display or the like and requires a uniform film thickness should have a predetermined inclination angle on the inner wall of the aperture. Thus, it is essential that the inner wall of the substrate to be deposited is not a shadow of the evaporation source, and that the position accuracy of the opening and the shape of the opening are formed with high accuracy.
And the manufacturing method of the metal mask of this example is such that the electroforming mask original plate of this example is produced by electroforming as a mother mold, and the manufacturing method of the electroforming mask original plate of this example is The master original plate of this example is prepared by transferring a predetermined shape.

First, the manufacturing method of a master original plate is demonstrated with reference to FIGS.
In FIG. 2, 17 indicates a master original plate, and this master original plate 17 is obtained by depositing a metal by plating on the surface of a mother mold having a predetermined shape and conductivity on the surface (electroforming method).
In this example, three substantially rectangular recesses 17a are arranged side by side, and each of the approximately rectangular recesses 17a has a bottom surface 17d having a depth D with respect to the side walls 17b, 17b, 17c, 17c and the upper surface 17-1. The side walls 17b, 17b, 17c, and 17c are inclined surfaces so that the bottom surface 17d is smaller than the opening of the substantially rectangular recess 17a.

First, as shown in FIG. 3A, the master original plate 17 applies a positive type photoresist 12 on a glass substrate 14 to a predetermined thickness. Here, the coating thickness is, for example, about 25 to 50 μm after curing.
Next, a photomask 13-1 in which a substantially rectangular light shielding pattern is drawn on the chromium film at a predetermined pitch is prepared, and the photoresist 12 is first exposed as shown in FIG. 3B.
Next, as shown in FIG. 3C, the second exposure is performed on the photoresist 12 using the photomask 13-2 on which a slightly rectangular light-shielding pattern slightly larger at the same pitch as that of the photomask 13-1.

Next, as shown in FIG. 3D, the photoresist 12 is exposed for the third time with a photomask 13-3 on which a slightly rectangular light-shielding pattern slightly larger at the same pitch as the photomask 13-2 is drawn.
As a result, the central portions of the substantially rectangular light shielding patterns of the photomasks 13-1, 13-2, and 13-3 are all shielded by the three exposures shown in FIGS. Since the shading pattern is gradually increased, the exposure amount is gradually reduced in the peripheral portion. Therefore, an insoluble portion is formed in a substantially trapezoidal shape in the portion corresponding to the light shielding pattern of the post-exposure positive type photoresist 12.

Finally, the photoresist 12 is developed, and a substantially trapezoidal convex portion 12a made of the resist 12 is formed on the glass substrate 14 as shown in FIG. 3E.
After the development, the substantially trapezoidal convex portion 12a is cured to produce a master master block.
Here, the substantially trapezoidal pattern formed by the photoresist 12 has been described as a substantially rectangular shape, but in reality, the size and thickness of the light emitting cell of the organic material 111 for the organic EL film to be deposited, the deposition pitch The number of photomasks required for exposure and the shape of each light-shielding pattern are determined based on the aperture shape of the specified metal mask specifications. The
Further, the photoresist may be a negative type instead of a positive type. In this case, the light shielding pattern formed on the photomask is produced in a state where the positive / negative of the photomask 13 is inverted.

  A procedure for producing the master original plate 17 from the mother die shown in FIG. 3E will be described.

First, as shown in FIG. 3E and FIG. 4A, a mother die in which a substantially trapezoidal convex portion 12 a made of a photoresist 12 is formed on a glass substrate 14 is prepared.
Next, as shown in FIG. 4B, a conductive film 15 is formed by electroless nickel plating or the like on the entire surface of the glass substrate 14 and the substantially trapezoidal convex portion 12a formed of the photoresist 12 thereon. Gives sex.
Next, as shown in FIG. 4C, a layer of plated metal 16 having a predetermined thickness is formed on the conductive film 15 with a metal such as nickel or a nickel alloy. That is, the side of the glass substrate 14 to which conductivity is imparted to the entire surface is used as a matrix when the plated metal 16 is formed.
Finally, as shown in FIG. 4D, the plated metal 16 is released from the conductive film 18 to form a master original plate 17. Here, when the glass substrate 14 on which the substantially trapezoidal convex portion 12a is formed is a male mold, the master master plate 17 forming the female mold has a substantially rectangular recess on the corresponding surface as shown in FIG. 4E. 17a is formed. The thickness of the master original plate 17 itself is formed by plating 2 to 5 times thicker than the depth of the substantially rectangular recess 17a so that sufficient mechanical strength and dimensional stability are ensured during handling. .

That is, when the depth of the substantially rectangular recess 17a of the master original plate 12 is D and the thickness from the bottom surface 17d to the surface 17-2 of the substantially rectangular recess 17a is T, for example, the depth D is 25 to 50 μm. On the other hand, the thickness T is formed to be 100 μm to 300 μm.
Here, the thickness T is determined in consideration of easiness in the mold release operation in the state shown in FIGS. 4C to 4D, handling properties, and the like. The substantially rectangular recess 17a is transferred to a metal mask, which will be described later, in a shape that is substantially inclined.

  According to the manufacturing method of the master original plate 17 of this example, as shown in FIGS. 3B to 3E, the desired photo resist 12 is formed on the glass substrate 14 using a plurality of photomasks 13-1, 13-2, 13-3. A three-dimensional convex portion 12a having slanted side walls is formed, and this is used as a matrix, and a metal is deposited to a desired thickness so as to have a substantially rectangular concave portion 17a shown in FIG. 2 by a plating method (electroforming method). Therefore, it is possible not only to be formed from the master mold with high transfer accuracy but also to have a master original plate having sufficient dimensional stability and strength and resistant to scratches and dust. In addition, since the master master is a metal body, it is difficult to be affected by humidity and changes over time, and can be stored easily. Based on this, a metal mask can be produced and used for repairing the product.

The manufacturing method of the electroforming mask master in this example is manufactured using the master original 17 shown in FIGS. 2 and 4C.
In FIG. 5, reference numeral 25 denotes an electroformed mask original plate, and the electroformed mask original plate 25 has a trapezoidal shape in which inclined side walls 22b, 22b, 22c, 22c and an upper surface 25d are provided on the conductive upper surface 20-1. Two substantially trapezoidal convex portions 22a are arranged side by side.
Hereinafter, the electroforming mask original plate 25 will be described with reference to FIG.

First, as shown in FIG. 6A, conductivity is imparted to the surface of the base substrate 19. In the following, an example in which the base substrate 19 is made of an insulating material glass and a nickel conductive film 20 is formed on the upper surface thereof by electroless plating will be described, but a thin metal plate made of stainless steel or the like may be used as the base substrate. Good.
Note that the conductive film 20 can be made of a conductive material such as chromium, tantalum, tungsten, or a light-transmitting ITO film instead of nickel. In addition to the method of forming a conductive film by electroless plating, a physical method such as sputtering, vacuum deposition, or ion plating can also be used for imparting conductivity. Furthermore, as a material for the base substrate, not only a glass plate and a stainless steel plate, but also a silicon wafer having no oxide film formed on the surface can be used when the mask size is small.

Next, as shown in FIG. 6B, a resist 21 having plating resistance is applied on the conductive film 20 by electroplating.
Next, as shown in FIG. 6C, the master original plate 17 in which the substantially rectangular concave portion 17 a is formed is pressed against the resist 21. At this time, in order to prevent the transfer pattern formed on the resist 21 from being damaged due to entrainment of bubbles, deaeration of bubbles in a vacuum, or one of the base substrate 19 and the master original plate 17 is warped and air is not involved. Do the pressing while doing so.

  Next, as shown in FIG. 6D, the resist 21 is cured in a state where the master original plate 17 is pressed (the resist after curing is denoted by reference numeral 22). Here, the curing method is performed by a vacuum heating furnace or the like when the resist 21 is a thermosetting resin, and when the resist 21 is an ultraviolet curable resin, a substrate such as an ultraviolet transmissive glass is used as the base substrate 19. The conductive film 20 is also made of a transparent conductive film or a semi-transparent conductive film so that curing is not greatly hindered, and ultraviolet irradiation is performed from the back surface of the substrate.

Next, as shown in FIG. 6E, the base substrate 19 provided with the cured resist 22 is released from the master original plate 17. Thereby, the base substrate 19 in which the substantially trapezoidal convex portions 22a made of the resist 22 are arranged at a predetermined pitch is obtained.
Next, in the region other than the substantially trapezoidal convex portion 22a formed by the cured resist 22 of the base substrate 19, the film-like residue 22b remaining on the upper surface 20a of the conductive film 20 is removed and washed. .
Then, as shown in FIG. 6F, the base substrate 19 in which the conductive film 20 is exposed around the substantially trapezoidal convex portion 22a having a height D is used as the electroforming mask original plate 25 shown in FIG. The

According to the method of manufacturing the electroforming mask original plate 25 of this example, as shown in FIGS. 6A to F, the resist 21 applied to the base substrate 19 having the conductive film 20 formed on the upper surface and imparted with conductivity is applied. On the other hand, the unevenness of the master original plate 17 is cast in a state where the resist 21 is soft, and then cured, and remains on the upper surface 20a of the conductive film 20 in a region other than the substantially trapezoidal convex portion 22a formed by the cured resist 22. The residue of the film-like resist 22 can be removed and washed, and the minimum necessary number of electroforming mask original plates 25 can be prepared from the master original plate 17 with necessary and sufficient accuracy without causing damage. .
Other than the resist 21, any other insulating resin having plating resistance may be used as long as the convex portion having a predetermined shape can be formed with respect to the concave portion of the master original plate 17.

The metal mask manufacturing method of this example is manufactured using the electroforming mask original plate 25 shown in FIGS. 5 and 6F.
In FIG. 7, reference numeral 35 denotes a metal mask, which can be formed into a predetermined shape by depositing metal on the upper surface 20a of the conductive film 20 of the electroforming mask master 25 by electroplating (electroforming method). In this example, three substantially rectangular openings 35a are arranged side by side, and inner walls 35b, 35b, 35c, and 35c having inclinations are provided in each of the substantially rectangular openings 25a.
Hereinafter, a method of manufacturing the metal mask 35 will be described with reference to FIG.

First, as shown in FIG. 1A, a conductive power source is connected to the conductive film 20 of the electroforming mask original plate 25 and immersed in a predetermined metal plating bath, and the conductive material exposed on the upper surface of the electroforming mask original plate 25 is exposed. Plating is deposited on the conductive film 20, and the plated metal 34 is deposited in a planar shape up to a thickness d (d <D) with respect to the depth D of the substantially rectangular recess 17a shown in FIG.
At this time, a nickel sulfamate bath or a nickel-cobalt alloy bath with cobalt added thereto is used as the plating bath, and as shown in FIG. 1A, the substantially trapezoidal convex portion 22a of the electroforming mask original plate 25 is used. The plating thickness is controlled by the current value and time in the plating process so that no metal is deposited on the surface 22d of the metal, and as shown in FIG. 1B, the upper portion of the substantially trapezoidal convex portion 22a is exposed from the upper surface of the plated metal 34. To be.

  Next, as shown in FIG. 1A, the deposited plated metal 34 is peeled off from the electroforming mask original plate 25. The peeled plated metal 34 is formed by the inclined side walls 22b, 22b, 22c, 22c of the substantially trapezoidal convex portion 22a of the electroforming mask original plate 25 shown in FIG. 5, and the openings 35a shown in FIG. The metal mask 35 is formed in a thin plate shape.

  Finally, as shown in FIG. 1D, a rectangular frame 30 for preventing deformation and reinforcing during work is fixed to the outer periphery of the metal mask 35 that has been finished by polishing and cleaning, and the metal mask 35 is fixed to the fixed frame 30. The metal mask device 36 is attached. FIG. 8 shows a perspective view of the metal mask device 36.

In the metal mask device 36 of this example, the metal mask device 36 is used to form a light emitting layer by depositing a light emitting material on the organic EL display substrate, for example, as shown in FIG. When the metal mask device 36 is positioned and mounted from above, and the film is formed from above as shown in FIG. 8, the inner walls 35b, 35b, 35c, and 35c of the opening of the metal mask device 36 have evaporation sources of light emitting materials. Since the inclination is provided so as to widen the side of the metal mask 35, there is no possibility that the end of the opening of the metal mask 35 itself becomes a wall and a shadow is generated.
Therefore, by forming a film using the metal mask device 36, it is possible to form a light emitting layer with a desired film thickness and small variation in the surface direction of the film.

According to the manufacturing method of the metal mask 35 of this example, the electroforming mask original plate 25 in which the substantially trapezoidal convex portions 22a are formed on the conductive film 20 is used. Because it is a three-dimensional replication method that deposits metal with a metal, it is less susceptible to dust, can reduce variations in dimensional accuracy between metal masks, and has high pattern accuracy and uniformity when used as a vapor deposition mask. A metal mask that can be formed with a small thickness can be manufactured at low cost.
That is, a metal mask 35 having an inclination on the inner wall of the substantially rectangular opening 35a can be produced on the conductive film 20 of the electroforming mask original plate 25 by electroplating, and this metal mask 35 is used for vapor deposition. The light emitting layer having a uniform thickness of the light emitting organic material is formed on the film forming substrate so that no shadow is formed between the evaporation source and the evaporation source of the photo organic material and the film forming substrate. When formed and emitted as an organic EL device, unevenness in luminance can be prevented.

  Further, according to the manufacturing method of the metal mask 35 of the present example, the minimum number of electroforming mask original plates 25 maintaining high dimensional accuracy and shape are prepared based on the master original plate 17, and the electroforming mask original plate is used as a base. The working metal mask having the opening side walls 35b, 35b, 35c, 35c having substantially the same inclination as the master original plate can be produced in a desired number without damaging the master master plate 17, Despite high accuracy, it can be produced at low cost.

The metal deposited on the exposed conductive film of the matrix by plating (electroforming) to produce the electroformed metal original plate 25 or the metal mask 35 is nickel, in addition to nickel. -Cobalt alloy, iron-nickel alloy, copper, etc. can be used in various ways.
Moreover, although the electroforming described above has been described with electroplating, it is needless to say that electroless plating may be used.
In addition, although the description has been given of a substantially rectangular shape having an inclination on the inner wall as the opening shape of the metal mask 35, the shape is not limited to the rectangular shape, and is appropriately formed to match the shape of the light emitting layer made of a light emitting material.
Further, since the metal mask obtained in this way can be produced with extremely high positions and patterns, it is not only used for evaporation masks for EL displays, but also for solder cream printing, or dot printing for touch panels, PDPs. It is also suitable for phosphor printing of (Plasma Display Panel).

  The manufacturing method of the metal mask, the electroforming mask original plate and the master original plate according to the present invention is not limited to the above-described examples, and various other configurations can be adopted without departing from the gist of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory sectional view showing a state in which plating is deposited on an electroforming mask master, B is a perspective view of A, and C is electroforming. The metal mask D formed by peeling off from the mask master plate is an explanatory sectional view of a state in which a frame is provided on the metal mask. It is a perspective view which cuts off an example of embodiment of the manufacturing method of this invention master original plate, and is shown partially. 2 is used to explain the fabrication of the master master for the master master plate in the example of FIG. 2. A is a post-photoresist coating post-exposure, B is the first exposure, C is the second exposure, and D is the third cross-section after the third exposure. FIG. E is a perspective view after development. 2 is used to explain the production of the master master plate in FIG. 2, A is a matrix shown in the example of FIG. 3, B is a conductive film, C is after plating metal deposition, D is an explanatory cross-sectional view after plating metal is peeled off, E is a perspective view of the metal (master master) after peeling. It is a perspective view which shows an example of embodiment of the manufacturing method of the mask original plate for electroforming of this invention. 5 is used to explain the production of the electroforming mask master in the example of FIG. 5. A is a base substrate having a conductive film, B is after resist application, C is immediately after pressing the master master, D is after master master pressing and resist curing, E Is an explanatory cross-sectional view after peeling from the master original plate and F after removing the resist residue. FIG. 2 is a perspective view showing the example metal mask of FIG. 1 with a part cut away. FIG. 8 is an explanatory perspective view of a metal mask device in which the metal mask of the example of FIG. 7 is fixed to a frame. For the description of the wet etching method as an example of the production of a conventional metal mask, A is a photoresist applied to a metal plate, B is exposed, C is developed, D is wet etched (with side etch), E is It is explanatory sectional drawing of an ideal etching shape. For the description of an electroforming method as an example of the production of a conventional metal mask, A is a photoresist having a predetermined shape formed on a conductive film, B is a plating metal deposited on the conductive film, C is It is explanatory sectional drawing which peeled the metal plating and made it the metal mask. Explaining the inconvenience of using a conventional metal mask as a vapor deposition mask, A is a state in which the metal mask is separated from the subject film material, and B is formed in close contact with the subject film material. The state, C is a vapor deposition material formed on the target film material, and D is an explanatory cross-sectional view showing an example of a required metal mask.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 19 ... Base substrate, 20 ... Conductive film, 21 ... Resist, 22 ... Resist, 22a ... Substantially trapezoidal convex part, 22b, 22c ... Inclined side wall, 25 ... Electroforming mask original plate, 34 ... Deposited metal, 35 ... Metal Mask, 35a ... opening, 36 ... metal mask device

Claims (3)

In the manufacturing method of the metal mask produced based on the electroforming mask master,
A first substrate coated with a resist is sequentially exposed using a plurality of photomasks having a predetermined transfer pattern formed in a predetermined shape and then developed, and the first substrate having a predetermined shape having inclined side walls is developed. Forming part,
Forming a first conductive film on the entire surface of the first substrate on the side where the predetermined convex portion is formed;
Depositing a metal on the upper surface of the first conductive film by plating;
Peeling the deposited metal from the first conductive film to produce a master original plate having a predetermined recess,
On the upper surface having conductivity of the second substrate, a convex portion substantially the same as the predetermined shape convex portion is formed of a resin based on the predetermined shape concave portion of the master original plate,
Peeling the second substrate having the convex portions from the resin from the master original plate to produce the electroforming mask original plate;
On the second conductive film exposed on the electroforming mask master, a desired metal is plated by plating to such a thickness that an opening having substantially the same side wall as the inclined side wall of the predetermined shape recess of the mask original is provided. Deposit and form a film,
A method for producing a metal mask, wherein the metal film is peeled off from the electroforming mask master. In the manufacturing method of the electroforming mask original plate produced based on the master original plate,
A first substrate coated with a photoresist is sequentially exposed using a plurality of photomasks having a predetermined transfer pattern formed in a predetermined shape and then developed, and a predetermined shape having inclined sidewalls on the first substrate. Forming convex parts,
Forming a conductive film on the entire surface of the first substrate on the side where the predetermined convex portion is formed,
Metal is deposited on the upper surface of the conductive film by plating;
The deposited master is peeled from the conductive film to produce the master original plate having a predetermined shape,
An organic film resist is applied on the conductive upper surface of the second substrate, and the predetermined shape concave portion of the master original plate is transferred to the formed organic film resist by applying a predetermined pressure to the predetermined shape convex portion. Are formed with resin,
A method for producing an electroforming mask original plate, wherein the second substrate having the convex portions made of the resin is peeled from the master original plate. A substrate coated with a photoresist is successively exposed using a plurality of photomasks having a predetermined transfer pattern formed in a predetermined shape and then developed to form a predetermined shape convex portion having an inclined side wall on the substrate,
Forming a conductive film over the entire surface of the substrate on the side where the predetermined-shaped convex portion is formed
Metal is deposited on the upper surface of the conductive film by plating;
A method for producing a master original plate, wherein the deposited metal is peeled off from the conductive film so as to have a recess having a predetermined shape.

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