TWI665319B - Metal mask substrate for vapor deposition, metal mask for vapor deposition, method of producing metal mask substrate for vapor deposition, and method of producing metal mask for vapor deposition - Google Patents

Abstract

A metal mask substrate (10) for vapor deposition, comprising a nickel-containing metal sheet (11) having a surface and a back surface that is a surface opposite to the surface, and at least one of the surface and the back surface is a photoresist layer. The target surface for the location has a surface roughness Sa of the target surface of 0.019 μm or less, and a surface roughness Sz of the target surface of 0.308 μm or less.

Description

Metal mask substrate for vapor deposition, metal mask for vapor deposition, method for producing metal mask substrate for vapor deposition, and method for producing metal mask for vapor deposition

The present invention relates to a method for producing a metal mask substrate for vapor deposition, a metal mask for vapor deposition, a metal mask substrate for vapor deposition, and a method for producing a metal mask for vapor deposition.

As one of the display devices manufactured by the vapor deposition method, an organic EL display is known. The organic layer included in the organic EL display is a deposit of sublimated organic molecules in the evaporation step. The mask hole provided in the metal mask for vapor deposition used in the vapor deposition step is a path through which sublimated organic molecules pass toward the substrate. The opening included in the mask hole has a shape corresponding to the shape of a pixel included in the organic EL display (for example, refer to Patent Document 1).

Prior art literature Patent literature

Patent Document 1 Japanese Patent Laid-Open No. 2015-055007

However, the method of manufacturing a metal mask for vapor deposition includes a step of forming an opening in a metal mask substrate for vapor deposition. In the step of forming the opening, for example, formation of a resist mask using a photolithography method and wet etching using a resist mask are performed. At this time, in the formation of the photoresist mask, the area to be exposed in the photoresist layer on the surface of the metal mask substrate for vapor deposition is exposed. Moreover, at least a part of the light irradiated to the photoresist layer is scattered by the surface of the metal shielding base material for vapor deposition, and a part of the scattered light is irradiated to a portion other than the exposure target area in the photoresist layer. As a result, when a negative type photoresist material is used in the photoresist layer, a residue portion of the photoresist material is formed due to light scattering, and when a positive type photoresist material is used in the photoresist layer, a photoresist mask is formed. Defect. In addition, the difference between the structure of the photoresist mask actually formed and the structure of the designed photoresist mask is increased. Therefore, the opening structure formed by the wet etching method and the designed opening structure are incurred. The difference between them may increase.

An object of the present invention is to provide a metal mask substrate for vapor deposition, a metal mask substrate for vapor deposition, and a metal mask substrate for vapor deposition, which can improve the structural accuracy of the openings of the metal mask for vapor deposition. Method and manufacturing method of metal mask for vapor deposition.

In order to solve the above-mentioned problems, a metal mask base material for vapor deposition includes a nickel-containing metal sheet having a surface and a back surface that is a surface opposite to the surface, and at least one of the surface and the back surface is used for the location of the photoresist layer. Target surface, the surface roughness Sa of the aforementioned target surface is 0.019 μm or less, and the surface roughness Sz of the target surface is 0.308 μm or less. In the metal shielding base material for vapor deposition, the reflectance of the regular reflection of light incident on the target surface may be 53.0% or more and 97.0% or less. Further, in the metal mask substrate for vapor deposition, the nickel-containing metal sheet may be a constant-fan steel sheet.

In order to solve the above-mentioned problems, a metal mask base material for vapor deposition includes a nickel-containing metal sheet having a surface and a back surface that is a surface opposite to the surface, and at least one of the surface and the back surface is used for the location of the photoresist layer. The target surface has a reflectance of regular reflection of light incident on the target surface of 53.0% or more and 97.0% or less.

In order to solve the above-mentioned problems, a method for manufacturing a metal mask substrate for vapor deposition includes forming a nickel-containing metal sheet on an electrode surface by electrolysis, and separating the nickel-containing metal sheet from the electrode surface. In addition, the nickel-containing metal sheet includes a surface and a back surface that is a surface opposite to the surface. At least one of the surface and the back surface is a target surface where a photoresist layer is located, and the electrolytic system is a surface of the target surface. The roughness Sa is 0.019 μm or less, and the surface roughness Sz of the target surface is 0.308 μm or less.

In order to solve the above-mentioned problems, a method for manufacturing a metal mask substrate for vapor deposition includes forming a nickel-containing metal sheet on an electrode surface by electrolysis, and separating the nickel-containing metal sheet from the electrode surface. In addition, the nickel-containing metal sheet includes a surface and a back surface that is a surface opposite to the surface. At least one of the surface and the back surface is a target surface where a photoresist layer is located, and the electrolytic system is made incident on the target surface. The reflectance of the regular reflection of light is 53.0% or more and 97.0% or less.

In order to solve the above-mentioned problems, a method for manufacturing a metal mask for vapor deposition includes forming a photoresist mask on the object surface of the aforementioned metal mask substrate for vapor deposition, and performing wet etching and etching using the photoresist mask The aforementioned object surface.

According to the above-mentioned configurations, since the scattering of light on the target surface where the photoresist mask is located is suppressed, the structure of the photoresist mask formed by exposure and development and the structure of the designed photoresist mask can be suppressed. A difference occurred. Furthermore, the structural accuracy of the opening provided in the metal mask for vapor deposition can be improved. In addition, in the configuration in which the nickel-containing metal sheet is a constant-fan steel sheet, since the target surface is formed by a constant-fan steel having a small thermal expansion coefficient among metal materials, a metal mask for vapor deposition due to heat during vapor deposition can also be suppressed. Its structural changes.

In order to solve the above-mentioned problem, the metal mask for vapor deposition includes a mask portion made of a nickel-containing metal sheet, and the mask portion includes a surface including a surface opening, and a back surface opening communicating with the surface opening as At least one of the front surface and the back surface is a target surface, a surface roughness Sa of the target surface is 0.019 μm or less, and a surface roughness Sz of the target surface is 0.308 μm or less. In this metal mask for vapor deposition, the reflectance of the regular reflection of light incident on the target surface may be 53.0% or more and 97.0% or less.

In order to solve the above-mentioned problem, the metal mask for vapor deposition includes a mask portion made of a nickel-containing metal sheet, and the mask portion includes a surface including a surface opening, and a back surface opening communicating with the surface opening as The back surface of the surface on the opposite side, at least one of the front surface and the back surface is a target surface, and the reflectance of the regular reflection of light incident on the target surface is 53.0% or more and 97.0% or less.

According to the above configurations, since light is suppressed from scattering on the target surface, when a photoresist mask is formed on the target surface and an opening is formed, the structure of the photoresist mask formed by exposure and development can be suppressed on the target surface Difference from the structure of the designed photoresist mask. Furthermore, the structural accuracy of the opening provided in the metal mask for vapor deposition can be improved.

In the above-mentioned metal mask for vapor deposition, the target surface includes at least the surface, and the surface opening is an opening for allowing vapor deposition particles to pass from the surface opening toward the back surface opening, and is larger than the back surface opening.

According to the aforementioned metal mask for vapor deposition, since the surface opening is larger than the back opening, a shadow effect on the vapor deposition particles entering from the surface opening can be suppressed. Here, when a hole is formed in the base material for manufacturing the mask portion, the size of the opening on the surface and the back surface is larger than that on the surface having a smaller amount of etching. This is because in the above-mentioned metal mask for vapor deposition, the surface opening is larger than the back opening, and the amount of etching on the surface is larger than the amount of etching on the back. In addition, since such a surface is a target surface, as a method of manufacturing a metal mask for vapor deposition, a method of forming a photoresist mask on the surface and etching the metal mask base material for vapor deposition from the surface can also be adopted. Therefore, the structural accuracy of the opening provided in the metal mask for vapor deposition can be improved.

In the above-mentioned metal mask for vapor deposition, the aforementioned nickel-containing metal sheet may be a Hengfan steel sheet. Since the target surface of the metal mask for vapor deposition is made of Hengfan steel with a small thermal expansion coefficient among metal materials, the structural change of the metal mask for vapor deposition due to heat during vapor deposition can also be suppressed.

In each of the above configurations, each of the two directions orthogonal to each other on the target surface may be an incident direction of the light, and a difference between the reflectances of the two directions may be 3.6% or less. With this configuration, it is also possible to improve the structural accuracy of the openings included in the metal mask for vapor deposition in the two-dimensional direction included in the target surface.

10‧‧‧ metal shielding substrate for evaporation

11, 321‧‧‧ nickel-containing metal sheet

11a‧‧‧ Substrate surface

11b‧‧‧ Back of substrate

12‧‧‧ support layer

20‧‧‧Mask device

21H‧‧‧Main frame hole

30‧‧‧ metal mask for evaporation

31‧‧‧ Sub-frame

32‧‧‧Mask

321H‧‧‧Mask hole

32LH‧‧‧Mask big hole

32SH‧‧‧Mask hole

33‧‧‧ Sub-frame hole

321‧‧‧ Nickel-containing metal sheet

321a‧‧‧Mask surface

321b‧‧‧Mask back

FIG. 1 is a cross-sectional view showing an example of a cross-sectional structure of an example of a metal mask base material for vapor deposition in one embodiment.

Fig. 2 is a cross-sectional view showing a cross-sectional structure of another example of a metal mask base material for vapor deposition in one embodiment.

Fig. 3 is a plan view showing a planar structure of a mask device according to an embodiment.

FIG. 4 is a cross-sectional view showing an example of a cross-sectional structure of a metal mask for vapor deposition in one embodiment.

Fig. 5 is a cross-sectional view showing another example of a cross-sectional structure of a metal mask for vapor deposition in one embodiment.

FIG. 6 is a step flow chart showing a flow of steps in a method of manufacturing a metal mask for vapor deposition.

Fig. 7 is a graph showing the relationship between the method for producing a metal shielding base material for vapor deposition, the surface roughness of a flat surface, and the reflectance in each test example.

FIG. 8 is a graph showing the reflectance of the target surface of the metal shielding base material for vapor deposition in each test example.

[Mode for Carrying Out the Invention]

Hereinafter, one embodiment of a method for producing a metal mask substrate for vapor deposition, a metal mask for vapor deposition, a metal mask substrate for vapor deposition, and a method for producing a metal mask for vapor deposition will be described. First, with reference to FIGS. 1 to 5, the structure of a metal mask base for vapor deposition and the structure of a metal mask for vapor deposition will be described. Next, the manufacturing method of the metal mask for vapor deposition is demonstrated with reference to FIG. 6, and the effect obtained from the surface characteristics of the metal mask base material for vapor deposition is demonstrated with reference to FIG.7 and FIG.8.

[Metal substrate for vapor deposition]

As shown in FIG. 1, the metal mask base material 10 for vapor deposition is composed of a nickel-containing metal sheet 11. The nickel-containing metal sheet 11 includes a substrate surface 11a and a substrate back surface 11b which is a surface opposite to the substrate surface 11a. At least one of the substrate surface 11a and the substrate back surface 11b is a target surface that is an object for the location of the photoresist layer. The target surface is the surface that forms a photoresist mask during the process of forming a metal mask for vapor deposition.

The material constituting the nickel-containing metal piece 11 is nickel or an iron-nickel alloy. For example, an iron-nickel alloy containing 30% by mass or more of nickel, and an alloy containing 36% by mass of nickel and 64% by mass of iron as the main component, that is, Hengfan Steel . In addition, the iron-nickel alloy constituting the nickel-containing metal sheet 11 may suitably contain manganese, carbon, chromium, copper, silicon, magnesium, cobalt, and the like as trace components. When the nickel-containing metal sheet 11 is a constant-fan steel sheet, the thermal expansion coefficient of the nickel-containing metal sheet 11 is, for example, about 1.2 × 10 ^-6 / ° C. In the case of the nickel-containing metal sheet 11 having such a thermal expansion coefficient, the degree of thermal expansion of the metal mask for vapor deposition manufactured in order to use the metal mask base material 10 for vapor deposition matches the degree of thermal expansion of the glass substrate. An example of the object is a glass substrate.

The thickness T1 of the nickel-containing metal sheet 11 is 1 μm or more and 100 μm or less, and preferably 2 μm or more and 40 μm or less. If the thickness T1 of the nickel-containing metal sheet 11 is 40 μm or less, the depth of the holes formed in the nickel-containing metal sheet 11 can be 40 μm or less. In the case of the nickel-containing metal sheet 11 having such a thickness T1, in the metal mask for vapor deposition manufactured using the metal mask substrate 10 for vapor deposition, the vapor deposition particles flying toward the metal mask for vapor deposition are used When viewed as a film-forming object, it is possible to reduce a portion (a portion that becomes overcast) that cannot be attached due to a metal mask for vapor deposition. In other words, the shadow effect is suppressed.

The surface characteristics of the target surface possessed by the nickel-containing metal piece 11 satisfy at least one of the following [Condition 1] and [Condition 2].

[Condition 1] The surface roughness Sa ≦ 0.019 μm and the surface roughness Sz ≦ 0.308 μm.

[Condition 2] 53.0% ≦ the reflectance of the target surface R ≦ 97.0%.

Surface roughness Sa and Sz are values measured by the method according to ISO 25178. The reflectance R is measured by measuring the reflected light due to regular reflection when the light emitted from the halogen lamp enters the target surface, and is calculated by the following formula (1). The light emitted from the halogen lamp is incident on a 14 mm ² area of the target surface at an incidence angle of 45 ° ± 0.2 ° with respect to the normal direction of the target surface. The area of the element receiving the reflected light was 11.4 mm ² . The measurement of the reflectance R is performed at three different locations on the target surface. The reflectance R of the target surface is an average value of the reflectance R obtained from each part of the target surface. In addition, the measurement of the reflectance R of each part is performed for each direction using the light irradiated from two directions orthogonal to each other. When the nickel-containing metal sheet 11 formed by rolling only the base material is used as a measurement target, any one of the directions of light incident on the target surface is viewed from a direction opposite to the target surface. The rolling direction of the base material is the same.

Reflectivity R = [light quantity of specular reflection light / incident light quantity] × 100 ... (1)

As long as the surface characteristics satisfy at least one of [Condition 1] and [Condition 2], the light that has been irradiated onto the target surface is suppressed from being scattered on the target surface. Further, when light is irradiated to the photoresist layer on the target surface, it is possible to suppress that a part of the light is scattered by the target surface, and the scattered light is irradiated to a portion other than the exposure target region in the photoresist layer. As a result, it is possible to suppress the difference between the structure of the photoresist mask formed by exposure and development and the structure of the designed photoresist mask. Further, it is possible to suppress a difference between the opening structure formed by the wet etching method and the designed opening structure.

From the viewpoint of suppressing the difference between the structure of the photoresist mask and the structure of the designed photoresist mask, the surface characteristics of the target surface of the nickel-containing metal sheet 11 preferably satisfy the following [Condition 3 ].

[Condition 3] The reflectance difference between two orthogonal directions is ≦ 3.6%

The two directions orthogonal to each other are directions included in the target surface. The two directions orthogonal to each other are a first direction and a second direction. The difference in reflectance between two mutually orthogonal directions is the difference between the reflectance of light radiated from the first direction and the reflectance of light radiated from the second direction.

Here, in the process for forming the nickel-containing metal sheet 11, the base material for forming the nickel-containing metal sheet 11 includes a rolling delay time. It is stretched in the direction (primary direction). As a result, among the directions included in the target surface, the reflectance R of the target surface differs between the direction in which the base material is stretched and a direction different from the direction.

In addition, when the process for forming the nickel-containing metal sheet 11 includes physical polishing or chemical mechanical polishing, polishing is performed in one direction or a plurality of directions different from each other. As a result, among the directions included in the target surface, the reflectance R of the target surface differs between the direction in which the polishing is performed and a direction different from the direction.

In addition, the processing for forming the nickel-containing metal sheet 11 includes the direction of the growth of the metal foil or the surface configuration of the electrode when the metal foil is formed by electrolysis. The direction may be different in the reflectance R of the target surface. The nickel-containing metal sheet 11 that satisfies the above [Condition 3] exhibits an effect of suppressing the difference between the structure of the photoresist mask and the structure of the designed photoresist mask in the secondary element direction included in the target surface. Since the above-mentioned anisotropy easily occurs due to electrolytic conditions, the effect of suppressing the difference between the structure of the photoresist mask and the structure of the designed photoresist mask becomes significant by satisfying the above [Condition 3].

In addition, as shown in FIG. 2, the metal mask base material 10 for vapor deposition may further include a resin-containing support layer 12 in addition to the nickel-containing metal sheet 11. That is, the metal mask base material 10 for vapor deposition may be embodied as a laminated body of the nickel-containing metal sheet 11 and the support layer 12. The material constituting the support layer 12 is, for example, a photoresist or polyimide.

When the material constituting the support layer 12 is a photoresist, the support layer 12 is a photoresist layer. The photoresist layer as the support layer 12 is adhered to, for example, The substrate surface 11 a of the nickel-containing metal sheet 11. At this time, the target surface of the nickel-containing metal sheet 11 includes at least the substrate surface 11a. The photoresist layer serving as the support layer 12 is formed in a sheet shape and then adhered to the substrate surface 11a. Alternatively, the photoresist layer as the support layer 12 is formed by applying a coating liquid for forming a photoresist layer on the substrate surface 11a.

When the material constituting the support layer 12 is polyimide, the polyimide layer as the support layer 12 is closely adhered to the back surface 11 b of the base material containing the nickel-containing metal sheet 11. At this time, the target surface of the nickel-containing metal sheet 11 includes at least the substrate surface 11a. The photoresist layer is located on the substrate surface 11 a of the nickel-containing metal sheet 11. The thermal expansion coefficient and temperature dependence of polyimide have the same degree of thermal expansion coefficient and temperature dependence of Hengfan Steel, so the support layer 12 caused by the temperature change of the support layer 12 can be suppressed. The expansion or contraction causes warpage in the nickel-containing metal sheet 11.

The thickness T2 of the support layer 12 is, for example, 5 μm or more and 50 μm or less. From the viewpoint of improving the mechanical strength of the laminated body of the support layer 12 and the nickel-containing metal sheet 11, the thickness T2 of the support layer 12 is preferably 5 μm or more. In the process of manufacturing a metal mask for vapor deposition, the support layer 12 may be removed from the nickel-containing metal sheet 11 by immersion in an alkali solution or the like. From the viewpoint of suppressing an excessively long time required for such removal, the thickness of the support layer 12 is preferably 50 μm or less.

[Manufacturing method of metal mask substrate for vapor deposition]

A method for producing a metal mask substrate for vapor deposition is included in a method for producing a metal mask for vapor deposition. The manufacturing method of the metal mask base material for vapor deposition uses either (A) electrolysis, (B) rolling and polishing, (C) electrolysis and polishing, or (D) only rolling.

In addition, when forming a rolling base material for forming the nickel-containing metal sheet 11, the oxygen mixed in the material for forming the rolling base material is usually removed. Those who remove oxygen mixed in the material, for example, are mixed with a deoxidizer such as granular aluminum or magnesium into a material for forming a base material. As a result, aluminum or magnesium was contained in the base material as a metal oxide such as aluminum oxide or magnesium oxide. Most of the metal oxide is removed from the base material before rolling the base material, but part of the metal oxide remains in the base material to be rolled. The metal oxide remaining in the base material is also one of the main causes of the anisotropy of the reflectance described above. In this regard, if the manufacturing method using electrolysis is used, the above-mentioned metal oxide is suppressed from being mixed into the nickel-containing metal sheet 11.

In the manufacturing method of the metal shielding base material for vapor deposition provided with the support layer 12, another type of support layer 12 may be attached to the object surface of the nickel-containing metal sheet 11, or may be applied to the nickel-containing metal sheet. The target surface of 11 is formed by coating or the like.

(A) Electrolysis

As a method for manufacturing the nickel-containing metal sheet 11, when electrolysis is used, the nickel-containing metal sheet 11 is formed on the surface of an electrode used for electrolysis. Then, the nickel-containing metal sheet 11 is separated from the surface of the electrode. Thereby, a nickel-containing metal sheet 11 is manufactured, which includes a target surface and a surface connected to the electrode surface as a surface opposite to the target surface. When the electrode surface has the same surface morphology as the target surface of the nickel-containing metal sheet 11, both the substrate surface 11a and the substrate back surface 11b of the nickel-containing metal sheet 11 have surface characteristics equivalent to the target surface. When the electrode surface has a greater surface roughness or a lower reflectance than the nickel-containing metal sheet 11 The surface opposite to the surface where the pole surfaces meet is the target surface of the nickel-containing metal sheet 11. Furthermore, both the substrate surface 11a and the substrate back surface 11b have a surface characteristic equivalent to that of the target surface. When a photoresist layer is formed on the target surface, the difference between the substrate surface 11a and the substrate back surface 11b can be reduced. The required load. In addition, the separated nickel-containing metal sheet 11 may be subjected to an annealing treatment after separation.

The electrolytic bath used for electrolysis contains, for example, an iron ion donor, a nickel ion donor, and a pH buffer. The electrolytic bath used for the electrolysis may contain a stress relaxation agent, a Fe ³⁺ ion masking agent, a malic acid, a citric acid, and the like, and is a weakly acidic solution adjusted to a pH suitable for electrolysis. Examples of the iron ion donating agent are ferrous sulfate 7 hydrate, ferrous chloride, and iron sulfamate. The nickel ion donor is, for example, nickel (II) sulfate, nickel (II) chloride, nickel sulfamate, or nickel bromide. The pH buffering agent is, for example, boric acid or malonic acid. Malonic acid also has the function of Fe ³⁺ ion shielding agent. The stress relieving agent is, for example, sodium saccharin. The electrolytic bath used for electrolysis is, for example, an aqueous solution containing the above-mentioned additives, and the pH can be adjusted to 2 or more and 3 or less by using a pH adjuster such as 5% sulfuric acid or nickel carbonate.

The electrolytic conditions used for the electrolysis are conditions such as adjusting the surface characteristics of the target surface and the composition ratio of nickel in the nickel-containing metal piece 11 by the temperature, current density, and electrolysis time of the electrolytic bath. In particular, in the production of the nickel-containing metal sheet 11 satisfying the above-mentioned [Condition 3], the growth of the electrolytic foil on the electrode surface is adjusted in the same way on the electrode surface, and the temperature, current density, and Configuration, stirring method of electrolytic bath, composition of electrolytic bath, etc. In addition, an appropriate gloss agent is added to the production of the nickel-containing metal sheet 11 that satisfies the above-mentioned [Condition 3]. The anode using the electrolytic conditions of the electrolytic bath is, for example, pure iron and nickel. The cathode in the electrolytic condition is, for example, a stainless steel plate such as SUS304. The temperature of the electrolytic bath is, for example, 40 ° C or higher and 60 ° C or lower. The current density is, for example, 1 A / dm ² or more and 4 A / dm ² or less.

(B) grinding

When grinding is used in the manufacturing method of the nickel-containing metal piece 11, the nickel-containing metal piece 11 before grinding is produced by electrolytic (A), or may be produced by rolling. The method of manufacturing the nickel-containing metal sheet 11 before rolling by rolling is to first roll a base material of the nickel-containing metal, and then anneal the rolled base material. At this time, the step of the substrate surface 11a in the nickel-containing metal sheet 11 before polishing is smaller than the step of the surface of the base material. In addition, the level difference of the back surface 11b of the base material in the nickel-containing metal sheet 11 before polishing is smaller than that of the back surface of the base material. Among the nickel-containing metal pieces 11 before polishing, a physical, chemical, chemical mechanical, or electrical polishing process is performed on a target surface that becomes a smooth surface. Thereby, a nickel-containing metal sheet 11 having a target surface is manufactured.

The polishing liquid used for chemical polishing is, for example, a chemical polishing liquid for iron-based alloys containing hydrogen peroxide as a main component. The electrolytic solution used for electric polishing is a perchloric acid-based electrolytic polishing liquid or a sulfuric acid-based electrolytic polishing liquid. Furthermore, the nickel-containing metal sheet 11 before grinding can be embodied as a thinner processed rolled nickel-containing metal sheet 11 by wet etching using an acidic etchant.

[Metal mask for vapor deposition]

As shown in FIG. 3, the mask device 20 includes a main frame 21 and a plurality of metal masks 30 for vapor deposition. The main frame 21 has a frame plate shape that supports a plurality of vapor deposition metal masks 30. Main frame 21 is mounted for vapor deposition On a vapor deposition device. The main frame 21 has a plurality of main frame holes 21H. Each of the main frame holes 21H penetrates the main frame 21 in almost the entire portion where the metal shield 30 for vapor deposition is attached.

The vapor deposition metal mask 30 includes a sub-frame 31 and a plurality of mask portions 32. The sub frame 31 has a frame plate shape that supports a plurality of mask portions 32. The sub-frame 31 is attached to the main frame 21. The sub-frame 31 has a plurality of sub-frame holes 33. Each of the sub-frame holes 33 penetrates the sub-frame 31 in almost the entirety of the portion where the mask portions 32 are mounted. Each mask portion 32 is fixed around the sub-frame hole 33 by welding or bonding. An example of a cross-sectional structure of each mask portion 32 will be described with reference to FIG. 4, and another example of a cross-sectional structure of each mask portion 32 will be described with reference to FIG. 5.

As shown in FIG. 4, each of the mask portions 32 is composed of a nickel-containing metal piece 321. The material constituting the nickel-containing metal sheet 321 is substantially the same as the material constituting the nickel-containing metal sheet 11 in the above-described metal shielding base material 10 for vapor deposition. The nickel-containing metal sheet 321 is manufactured by forming a mask hole 321H in the nickel-containing metal sheet 11 described above. The nickel-containing metal sheet 321 includes a mask surface 321 a and a mask back surface 321 b which is a surface opposite to the mask surface 321 a. At least one of the mask surface 321a and the mask back surface 321b is a target surface where the photoresist layer is located. The mask surface 321 a is a surface facing the vapor deposition source in the vapor deposition device. The mask back surface 321b is a surface which contacts a vapor deposition target, such as a glass substrate, in a vapor deposition apparatus. The surface characteristics of the target surface provided in the nickel-containing metal piece 321 are substantially equal to the surface characteristics of the target surface provided in the nickel-containing metal piece 11. Among the target surfaces included in the nickel-containing metal piece 321, the surface characteristics of the area other than the mask hole 32H satisfy at least one of the above-mentioned [Condition 1] and [Condition 2]. Also, on nickel-containing metal sheet Of the target surfaces provided in 321, the surface characteristics of the area other than the mask hole 32H are preferably to satisfy the above-mentioned [Condition 3].

The mask portion 32 has a plurality of mask holes 321H penetrating through the nickel-containing metal sheet 321. The side surfaces of the holes defining the mask holes 321H are drawn in a gentle curve from the mask surface 321a toward the mask back surface 321b in the cross-sectional view of the thickness direction of the nickel-containing metal piece 321. The mask surface 321a includes a surface opening Ha as an opening of the mask hole 321H. The mask back surface 321b includes a back opening Hb as an opening of the mask hole 321H. The size of the front opening Ha is larger than that of the back opening Hb when viewed in a plane. Each mask hole 321H is a path through which vapor-deposited particles sublimated from a vapor deposition source pass. The vapor deposition particles sublimated from the vapor deposition source proceed from the front opening Ha to the back opening Hb. The mask hole 321H having a larger surface opening Ha than a rear surface opening Hb can suppress a shadow effect on the vapor deposition particles entering from the surface opening Ha.

Here, when a mask hole 321H is formed in the nickel-containing metal sheet 11 of the metal mask base material 10 for vapor deposition, the size of the opening is on the surface having a large amount of etching in the base material surface 11a and the base material back surface 11b. It becomes larger than the person with the smaller amount of etching. In the case of the above-described vapor deposition metal mask 30, the front surface opening Ha is larger than the back surface opening Hb. Therefore, the amount of etching of the substrate surface 11a can be set larger than the amount of etching of the substrate back surface 11b. In addition, the substrate surface 11a is a target surface. In the method for manufacturing the metal mask 30 for vapor deposition, a photoresist mask can be formed on the substrate surface 11a, and a nickel-containing metal can be formed from the substrate surface 11a. Method of etching the sheet 11. As a result, scattering of light on the target surface where the photoresist mask is located is suppressed. Therefore, the structure of a photoresist mask formed by exposure and development can be suppressed. There is a difference from the structure of the designed photoresist mask. Furthermore, the structural accuracy of the mask hole 321H provided in the metal mask 30 for vapor deposition can be improved. In particular, the target surface satisfying the above-mentioned [Condition 3] can also improve the structural accuracy of the mask hole 321H in the second element direction of the target surface.

In another example shown in FIG. 5, each mask portion 32 has a plurality of mask holes 321H penetrating through the nickel-containing metal piece 321. In the example shown in FIG. 5, the size of the front surface opening Ha is larger than that of the back surface opening Hb when viewed in plan. Each of the mask holes 321H is composed of a large mask hole 32LH having a front surface opening Ha and a small mask hole 32SH having a rear surface opening Hb. The large mask hole 32LH is a hole whose surface area decreases monotonously from the surface opening Ha toward the mask back surface 321b. The mask small hole 32SH is a hole whose cross-sectional area decreases monotonously from the back opening Hb toward the mask surface 321a.

The side of the hole that partitions each of the mask holes 321H is in section view, and has a portion where the large mask hole 32LH and the small mask hole 32SH are connected. The portion where the large mask hole 32LH and the small mask hole 32SH are connected is located in the middle of the thickness direction of the nickel-containing metal sheet 321. The portion connecting the large mask hole 32LH and the small mask hole 32SH has a shape protruding toward the inside of the mask hole 321H. The distance between the most prominent part of the hole side surface of the mask hole 321H and the mask back surface 321b is the step height SH. The cross-sectional structure system described above with reference to FIG. 4 is an example in which the step height SH is zero. From the viewpoint of suppressing the shadow effect, the step height SH is preferably zero. Furthermore, in order to obtain the mask portion 32 with the step height SH of zero, for example, the mask hole 321H is formed by wet etching from the substrate surface 11a to the substrate back surface 11b. No, nickel-containing The thickness of the metal piece 11 is preferably 40 μm or less. From such a viewpoint, the metal mask base material 10 for vapor deposition manufactured by (A) electrolysis, (B) rolling and polishing, and (C) electrolysis and polishing is also suitable.

Here, when the mask large hole 32LH is formed in the nickel-containing metal sheet 11, the method of etching the nickel-containing metal sheet 11 from the substrate surface 11a is adopted. In addition, when forming the mask pinhole 32SH in the nickel-containing metal sheet 11, the method of etching the nickel-containing metal sheet 11 from the back surface 11b of the substrate is adopted. The substrate surface 11a is a target surface and the substrate back surface 11b is also a target surface, which suppresses light scattering at the target surface where each photoresist mask is located. Therefore, the structural accuracy of the mask hole 321H provided in the metal mask 30 for vapor deposition can be further improved.

[Manufacturing method of metal mask for vapor deposition]

The method for manufacturing the metal mask 30 for vapor deposition illustrated in FIG. 4 and the method for manufacturing the metal mask 30 for vapor deposition illustrated in FIG. 5 are different in the steps of wet-etching the nickel-containing metal sheet 11, but another On the one hand, the steps other than this are roughly the same. Hereinafter, a method for manufacturing the metal mask 30 for vapor deposition described in FIG. 4 will be mainly described, and a method for manufacturing the metal mask 30 for vapor deposition described in FIG. 5 will be omitted.

As shown in FIG. 6, in the method for manufacturing a metal mask for vapor deposition, first, a nickel-containing metal sheet 11 is prepared by (A) electrolysis or (B) rolling and polishing described above (step S1-1). Next, a photoresist layer is formed on one of the target surfaces of the nickel-containing metal sheet 11 (step S1-2), and a photoresist mask is formed on the target surface by exposing and developing the photoresist layer. (Step S1-3).

Next, a mask hole 321H is formed in the nickel-containing metal sheet 11 by wet etching using a target surface of the photoresist mask (step S1-4). Subsequently, the photoresist mask is removed from the target surface to manufacture the above-mentioned mask portion 32 (step S1-5). Then, the mask surface 321a of the plurality of mask portions 32 is fixed to the sub-frame 31, and the above-described metal mask for vapor deposition is manufactured (step S1-6).

The etchant for etching the nickel-containing metal sheet 11 is an acidic etchant, as long as it is an etchant capable of etching Hengfan Steel. The acidic etching solution is, for example, a solution in which any one of perchloric acid, hydrochloric acid, sulfuric acid, formic acid, and acetic acid is mixed with ferric perchlorate liquid and a mixed liquid of ferric perchlorate liquid and ferric chloride liquid. The etching of the target surface may be an immersion type in which the nickel-containing metal piece 11 is immersed in an acidic etching solution, or a spray type in which an acidic etching solution is sprayed on the target surface of the nickel-containing metal piece 11. In addition, the etching of the target surface may be a rotary type in which an acidic etchant is dropped on the nickel-containing metal piece 11 rotated by a rotator.

Here, when light is irradiated to the photoresist layer on the target surface, a part of the light is suppressed from being scattered on the target surface and the scattered light is irradiated to a portion other than the exposure target region in the photoresist layer. Therefore, it is possible to suppress a difference between the structure of the photoresist mask formed by exposure and development and the structure of the designed photoresist mask. Furthermore, the structural accuracy of the mask hole 321H included in the nickel-containing metal piece 321 can be improved. In addition, the photoresist layer formed on the target surface may be attached to the target surface after forming a sheet shape, or may be formed by applying a coating solution for forming a photoresist layer on the target surface.

Furthermore, in the method for manufacturing the metal mask 30 for vapor deposition described in FIG. 5, the steps from step S1-1 to step S1-5 are applied to the substrate surface 11a corresponding to the mask surface 321a. Thereby, a large mask hole 32LH is formed. Next, a photoresist for protecting the large mask hole 32LH is filled in the large mask hole 32LH. Next, the steps from step S1-2 to step S1-5 described above are performed by applying the back surface 11b of the substrate corresponding to the back surface 321b of the mask, thereby forming the mask small hole 32SH, and obtaining the mask portion 32. Then, the mask surface 321 a of the plurality of mask portions 32 is fixed to the sub-frame 31 to produce the above-described metal mask for vapor deposition (step S1-6).

When the metal mask base material 10 for vapor deposition includes a support layer 12 made of polyimide, the support layer 12 is removed from the metal mask base material 10 for vapor deposition after step S1-5. The separation of the support layer 12 is removed by peeling by laser irradiation, chemical dissolution or peeling, physical peeling, and the like. Alternatively, when the metal mask base material 10 for vapor deposition includes a support layer 12 made of polyimide, the support layer 12 may be mounted on the sub-frame 31 as a component of the metal mask for vapor deposition. If the support layer 12 is chemically removed, compared with the case where the support layer 12 is physically peeled from the nickel-containing metal sheet 11, external force does not act on the nickel-containing metal sheet 11 and suppresses occurrence of wrinkles in the nickel-containing metal sheet 11. Fold or deform. Furthermore, in the method for chemically removing the support layer 12 from the metal mask base material 10 for vapor deposition, for example, it is preferable to use an alkali solution in which the support layer 12 is peeled from the nickel-containing metal sheet 11 by dissolving the support layer 12.

[Test example]

The surface roughness Sa, Sz, the reflectance R, the reflectance difference, and the photoresist of the above-described vapor-deposited metal mask base material 10 will be described with reference to FIGS. 7 and 8. Mask processing accuracy. FIG. 7 shows the surface roughness Sa, Sz, reflectance R, and reflectance difference at each level in Test Examples 1 to 9. FIG. 8 shows the reflected light angle dependence of each of the reflectances measured for each of Test Examples 1 to 9 as Test Example 1, Test Example 2, Test Example 3, and Test Example 9 which are representative examples. Sex.

As shown in FIG. 7, Test Example 1, Test Example 2, Test Example 3, Test Example 6, and Test Example 7 are metal mask substrates 10 for deposition having a thickness of 20 μm, which are manufactured by the above-mentioned (A) electrolysis. . Test Example 4 and Test Example 5 are each a metal mask substrate 10 for deposition having a thickness of 20 μm, which is manufactured by rolling and polishing described above (B). In addition, the metal mask base material 10 for vapor deposition manufactured by said (A) electrolysis shows the surface characteristic of the surface contacting an electrode as the surface characteristic equivalent to a target surface. At this time, the surface roughness Sa of the electrode made of SUS was 0.018 μm, and the surface roughness Sz was 0.170 μm. Each of Test Example 8 and Test Example 9 is a metal mask base material 10 for vapor deposition before polishing obtained by rolling, and is a metal mask base material 10 for vapor deposition that has not been polished. The thickness of each of Test Example 8 and Test Example 9 is only 10 μm in the polishing amount of Test Example 8 and Test Example 9, and is thicker than that of Test Example 4 and Test Example 5, respectively.

Test example 1, test example 2, test example 3, test example 6, test example 7 are aqueous solutions to which the following additives are added, and an electrolytic bath adjusted to pH 2.3 is used, and the current density is adjusted to 1 (A / dm ² ) to 4 (A / dm ² ) or less. Test example 1, test example 2, test example 3, test example 6, test example 7 The composition ratios of iron and nickel are different from each other.

(Electrolyte for test example)

‧Ferrous sulfate‧Hydrate: 83.4g

‧Nickel (II) sulfate‧6 hydrate: 250.0g

‧Nickel (II) chloride‧6 hydrate: 40.0g

‧Boric acid: 30.0g

‧Sodium saccharin 2 hydrate: 2.0g

‧Malonic acid: 5.2g

‧Temperature: 50 ℃

Test Example 4 and Test Example 5 were each obtained by chemically polishing a nickel-containing metal sheet 11 obtained by rolling with a hydrogen peroxide-based chemical polishing liquid.

Test Example 8 and Test Example 9 are the nickel-containing metal pieces 11 before grinding in Test Examples 4 and 5 obtained by rolling and grinding, and are at a level where no chemical grinding is applied.

At each level from Test Example 1 to Test Example 7, it was confirmed that the surface roughness Sa of the target surface was 0.019 μm or less, and the surface roughness Sz of the target surface was 0.308 μm or less. In contrast, in each of the levels of Test Example 8 and Test Example 9, the surface roughness Sa of the target surface is about 0.04 μm. Therefore, if it is a metal for vapor deposition produced by the above (A) electrolysis or (B) polishing It was confirmed that the mask substrate significantly reduced the surface roughness Sa. In each of the levels of Test Example 8 and Test Example 9, the surface roughness Sz of the target surface was about 0.35 μm or more. Therefore, if it is a metal mask base material for vapor deposition manufactured by said (A) electrolysis or (B) grinding | polishing, it is confirmed that the surface roughness Sz is reduced.

As shown in FIGS. 7 and 8, at each of the levels from Test Example 1 to Test Example 3, it was confirmed that the reflectance R is 53.0% or more and 97.0% or less. In contrast, in Test Examples 8 and 9, it was confirmed that the reflectance R is smaller than 53.0% and has a larger half-value width than other test examples. Therefore, if it is a metal shielding base material for vapor deposition manufactured by the above (A) electrolysis or (B) polishing, it is confirmed that a large reflectance R of 53.0% or more is obtained.

Furthermore, in each of the levels from Test Example 1 to Test Example 3, it was confirmed that the reflectance difference between the two directions orthogonal to each other was 2.5% or less. Moreover, in Test Example 5, it was confirmed that the reflectance difference between the two directions orthogonal to each other was 3.6%. In contrast, in Test Example 9, the reflectance difference was 6.2%, and even in Test Example 6, where the electrolytic conditions were different from Test Examples 1 to 3, it was confirmed that the reflectance difference was 6.5%. Therefore, it was confirmed that a low reflectance difference that cannot be obtained by rolling can be obtained by adjusting the temperature or current density of the electrolytic bath in (A) electrolysis.

In addition, the minimum resolution size of the photoresist mask formed on each of the test surfaces of Test Examples 1 to 7 was confirmed when the circular holes were formed in the photoresist layer by exposure to ultraviolet light. Within a range of 4 μm or more and 5 μm or less. In particular, in each of Test Examples 1 to 3 and Test Example 5 with a reflectance difference of 3.6% or less, in the direction of the two-dimensional element included in the target surface, it was confirmed that the change in the size of the minimum resolution is larger than that in Test Example 6. Or test example 7 is less. In particular, in each of Test Examples 1 to 3 having a reflectance difference of 2.5% or less, a size smaller than that of Test Example 5 having a reflectance difference of 3.6% or less was obtained as the minimum resolution. On the other hand, on the surfaces of Test Example 8 and Test Example 9, The minimum resolution size of the photoresist mask formed by this method is 7 μm or more when a circular hole is formed in the photoresist layer by exposure to ultraviolet light. Therefore, from the viewpoint of improving the structural accuracy of the openings included in the metal mask for vapor deposition, the reflectance difference is preferably 3.6% or less, and more preferably 2.5% or less.

In addition, the said embodiment can be changed as follows and implemented.

‧ When manufacturing a metal mask base material for evaporation by electrolysis, a pattern that becomes a mask of the nickel-containing metal sheet 11 can be formed in advance on the surface of the electrode. In this manufacturing method, a nickel-containing metal sheet 11 is formed on a portion of the electrode surface other than the pattern. Then, in a state where the nickel-containing metal sheet 11 is formed on the electrode surface, the pattern is removed from the electrode surface by dissolution or the like, and then the nickel-containing metal sheet is separated from the electrode surface. Thereby, a metal mask base material for vapor deposition is manufactured. The pattern formed in advance on the electrode surface may be a pattern that suppresses the growth of the nickel-containing metal sheet 11 in the pattern, and for example, a photoresist pattern may be used.

With such a method for producing a metal masking base material for vapor deposition, holes or pits can be formed in portions corresponding to a pattern in the metal masking base material 10 for vapor deposition. Then, the pattern structure formed on the electrode surface can be matched with the structure possessed by the holes such as the mask holes. Thereby, the load of wet etching on the metal mask base material 10 for vapor deposition can be reduced, and the step of wet etching itself can also be omitted.

• In step S1-6, the object fixed to the sub-frame 31 may be changed from the mask surface 321a in the plurality of mask portions 32 to the mask back surface 321b in the plurality of mask portions 32. That is, a metal shield for vapor deposition The cover may be a structure in which a mask surface 321 a is fixed to the sub-frame 31, or a structure in which a mask back surface 321 b is fixed to the sub-frame 31.

‧ In the manufacturing method of the metal mask 30 for vapor deposition described in FIG. 5, the step of forming the large mask hole 32LH may be changed to the step of forming the small mask hole 32SH.

Claims (12)

A metal masking substrate for vapor deposition, which is a metal masking substrate for vapor deposition having a mask hole formed by wet etching using a photoresist mask. The metal mask substrate is provided with a surface opposite to the surface. The nickel-containing metal sheet on the back surface of the side surface, at least one of the surface and the back surface is a target surface where the photoresist layer of the photoresist mask is located, and the surface roughness Sa of the target surface is 0.019 μm The surface roughness Sz of the target surface is 0.308 μm or less. For example, the metal shielding base material for vapor deposition of claim 1, wherein the reflectance of the regular reflection of light incident on the target surface is 53.0% or more and 97.0% or less. For example, the metal shielding base material for vapor deposition of claim 2, wherein the two directions orthogonal to each other on the target surface are the directions of incidence of the light, respectively, and the difference in the reflectance between the two directions is 3.6% or less. The metal shielding base material for evaporation according to any one of claims 1 to 3, wherein the nickel-containing metal sheet is an invar sheet. A metal mask for vapor deposition includes a mask portion composed of a nickel-containing metal sheet and formed by wet etching of the nickel-containing metal sheet using a photoresist mask. The mask portion includes: a surface. The surface of the opening has a back surface including a back surface opening communicating with the surface opening, and is a back surface that is a surface opposite to the surface. At least one of the surface and the back surface is a target surface; the surface roughness Sa of the target surface is 0.019 μm or less, and the surface roughness Sz of the target surface is 0.308 μm or less. For example, the metal mask for vapor deposition of claim 5, wherein the reflectance of the regular reflection of the light incident on the target surface is 53.0% or more and 97.0% or less. For example, the metal mask for vapor deposition of claim 6, wherein the two directions orthogonal to each other on the target surface are the directions of incidence of the light, respectively, and the difference between the reflectances of the two directions is 3.6% or less. The metal mask for vapor deposition according to any one of claims 5 to 7, wherein the object surface includes at least the surface, and the surface opening is an opening through which vapor deposition particles pass from the surface opening toward the back surface opening. The back opening is larger. The metal mask for evaporation according to any one of claims 5 to 7, wherein the nickel-containing metal sheet is a Hengfan steel sheet. A method for manufacturing a metal mask substrate for vapor deposition, comprising: forming a nickel-containing metal sheet having a mask hole by wet etching using a photoresist mask on an electrode surface by electrolysis; and The electrode surface separates the nickel-containing metal sheet; the nickel-containing metal sheet has a surface and a back surface that is a surface opposite to the surface, and at least one of the surface and the back surface is used to form light of the photoresist mask. In the target surface where the resist layer is located, the electrolytic system reduces the surface roughness Sa of the target surface to 0.019 μm or less and the surface roughness Sz of the target surface to 0.308 μm or less. For example, the manufacturing method of the metal mask base material for vapor deposition according to claim 10, wherein the electrolytic system makes the reflectance of the regular reflection of the light incident on the target surface 53.0% or more and 97.0% or less. A manufacturing method of a metal mask for vapor deposition includes forming a photoresist mask on an object surface of a metal mask substrate for vapor deposition, and etching the object surface by wet etching using the photoresist mask. The metal masking base material for vapor deposition is the metal masking base material for vapor deposition according to any one of claims 1 to 4.