JP2017183277A - Substrate for flexible device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a substrate for a flexible device, which is superior in moisture-barrier property and glass layer adhesion and excellent in surface smoothness, and which is arranged so that the occurrence of particles on a glass layer surface and the occurrence of repellence is suppressed effectively; and a method for manufacturing the substrate.SOLUTION: A substrate for a flexible device comprises: a nickel-plated metal base material arranged by forming a nickel-plated layer on at least one surface of a metal base material, or a nickel-based base material; an electrically insulative glass layer on a surface of the nickel-plated layer or nickel-based base material, which is formed from bismuth-based glass like a layer; and an oxide film formed on the surface of the nickel-plated layer or the surface of the nickel-based base material, and having asperities on its surface. The bismuth-based glass includes 70-84 wt% of BiO, 10-12 wt% of ZnO, and 6-12 wt% of BO.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a substrate for a flexible device and a method for producing the same, and more specifically, is excellent in moisture barrier properties and adhesion of an insulating layer, has no surface defects, and is suitable for organic EL-related applications. The present invention relates to a usable flexible device substrate and a method of manufacturing the same.

Flexible device substrates used in organic EL lighting, organic EL displays, organic solar cells, and the like are required to have smoothness and insulating properties in addition to barrier properties such as moisture barrier properties and vapor barrier properties.
Patent Document 1 below proposes a structure of an organic EL element in which a transparent conductive layer, an organic light emitting medium layer, and a cathode layer are sequentially laminated on a plastic film substrate, and a metal foil is laminated via an adhesive layer. However, such a plastic film substrate is not satisfactory in terms of moisture barrier properties.
Patent Document 2 below proposes a substrate for a flexible device in which a flattening layer made of a polyimide resin is provided on a stainless steel base material. However, since the polyimide resin has a high water absorption property, it also has a moisture barrier property. Not satisfied with.
Further, Patent Document 3 below proposes a flexible solar cell substrate in which a silica-based glass is formed on a stainless steel base material. However, silica-based glass generally has a smaller thermal expansion coefficient than stainless steel, and is compatible with the stainless steel base material. In addition to lack of adhesion, silica-based glass has problems that it is vulnerable to bending and impact.
Various glass substrates that can be used as thin film electric circuits and flexible display substrates have also been proposed (Patent Document 4, etc.). However, glass substrates have a characteristic that they are vulnerable to bending such as twisting, and are more robust as flexible device substrates. Higher ones are desired.

  In order to solve such a problem, the present inventors formed a nickel plating layer on the surface of a metal base material, and laminated the surface of the nickel plating layer with a bismuth glass having electrical insulation. The metal substrate for flexible devices was proposed (patent document 5).

JP 2004-171806 A JP 2011-97007 A JP 2006-80370 A JP 2012-197185 A JP 2014-107053 A

The metal substrate for flexible devices is excellent in bending resistance because a bismuth-based glass excellent in moisture barrier property and adhesion to a metal substrate is laminated on a metal substrate excellent in mechanical strength. As well as being excellent in insulation and flatness, it is lightweight and flexible, but on the surface of the glass layer after firing, there are cases where fluff that is a minute convex part or repellency that is a minute concave part occurs. The smoothness of the glass layer may be impaired due to such minute defects.
As a result of studying the cause of these micro defects formed on the surface of the glass layer, the present inventors have found that these micro defects formed on the surface of the glass layer are caused by generation of crystals from the glass or burst of bubbles. It was found that the formation was caused by the marks, and in particular, the repelling occurred due to the influence of the surface tension based on the turbulence of the glass layer due to the bursting marks of the bubbles and the crystallization of the glass.

  Accordingly, an object of the present invention is to provide a metal substrate for a flexible device excellent in surface smoothness, which is excellent in moisture barrier properties and adhesion of the glass layer, and in which occurrence of fluff and repellency on the surface of the glass layer is effectively suppressed, and The manufacturing method is provided.

According to the present invention, a nickel-plated metal substrate or nickel-based substrate having a nickel-plated layer formed on at least one surface of a metal substrate, and an electrically insulating material on the nickel-plated layer or nickel-based substrate. A substrate for a flexible device having a glass layer in which a bismuth-based glass having a layer is formed, and an oxide film having irregularities on the surface is formed on the surface of the nickel plating layer or the surface of the nickel-based substrate. The bismuth-based glass contains Bi ₂ O ₃ in an amount of 70 to 84% by weight, ZnO in an amount of 10 to 12% by weight, and B ₂ O ₃ in an amount of 6 to 12% by weight. A substrate is provided.

In the flexible device substrate of the present invention,
1. The bismuth-based glass contains SiO ₂ and / or Al ₂ O ₃ , the amount of SiO ₂ is 0 to 2 wt%, and the content of Al ₂ O ₃ is 0 to 1 wt% (SiO ₂ and Not including the case where both Al ₂ O ₃ are zero),
2. The bismuth-based glass contains CuO and / or NiO, the CuO content is 0 to 2% by weight, the NiO content is 0 to 2% by weight (including the case where both CuO and NiO are zero) Not)
3. The bismuth-based glass is any one of Y ₂ O ₃ , ZrO ₂ , La ₂ O ₃ , CeO ₂ , TiO ₂ , CoO, and Fe ₂ O ₃ in an amount of 1.5% by weight or less (excluding zero). Containing,
4). The arithmetic average roughness (Ra) of the surface of the oxide film is in the range of 30 to 100 nm,
5. The maximum height roughness (Rz) of the surface of the oxide film is in the range of 420 to 900 nm;
6). The thickness of the oxide film is in the range of 40 to 1200 nm;
7). The glass layer has a thickness of 2 to 45 μm;
8). The presence of iron in the surface of the nickel plating layer or the surface of the nickel-based substrate;
9. Of the iron present in the nickel plating layer surface layer or nickel-based substrate surface layer, metallic iron is 3 atomic% or less,
10. The oxygen ratio in the nickel plating layer surface layer or the nickel-based substrate surface layer is 30 atomic% or more,
11. Of the nickel present in the nickel plating layer surface layer or nickel-based substrate surface layer, the proportion of metallic nickel is 20 atomic% or less,
12 When the amount of oxygen in any surface in the thickness direction of the glass layer is 100%, the amount of oxygen at the interface between the glass layer and the nickel plating layer or the nickel-based substrate is 80% or more,
13. A layer serving as a base for forming an electrode layer is formed on the surface of the glass layer, and the base layer is made of nickel or indium tin oxide.
Is preferred.

According to the present invention, there is also provided a nickel-plated metal substrate or nickel-based substrate having a nickel-plated layer formed on at least one surface of the metal substrate, and electrical insulation on the nickel-plated layer or nickel-based substrate. There is provided a flexible device substrate comprising: a glass layer in which a bismuth-based glass having a property is formed in a layer; and a base layer serving as a base for forming an electrode layer on the surface of the glass layer.
In the flexible device substrate of the present invention, the underlayer is made of any of nickel, indium tin oxide, silver, gold, copper, magnesium-silver, gold-copper, silver-copper, zinc oxide, cobalt, and palladium. It is preferable to consist.

According to the present invention, a nickel-plated metal substrate or a nickel-based substrate having a nickel plating layer formed on at least one surface of a metal substrate is fired in an oxygen-containing atmosphere (hereinafter referred to as “calcination”). In this way, an oxide film forming step for forming an oxide film on the surface of the nickel plating layer or the surface of the nickel-based substrate, Bi ₂ O ₃ , ZnO, B ₂ O ₃ is formed on the oxide film. And a glass layer forming step of forming a bismuth-based glass layer to be contained.
In the method for manufacturing a flexible device substrate of the present invention,
1. In the oxide film forming step, firing the nickel plating layer or the nickel-based substrate surface at a temperature of 550 to 900 ° C.,
2. In the glass layer forming step, the bismuth-based glass composition coated on the nickel plating layer or the nickel-based substrate is baked at a temperature of 550 to 900 ° C. for 10 to 300 seconds,
Is preferred.

  According to the present invention, the flexible device substrate, the electrode layer formed on the glass layer or the base layer of the flexible device substrate, and the organic thin film light emitting layer formed on the electrode layer And a transparent electrode layer formed on the organic thin-film light-emitting layer.

In this invention, generation | occurrence | production of the crystal | crystallization (burst) and repelling of the glass layer surface is suppressed, and the board | substrate for flexible devices which has a glass layer excellent in surface smoothness and insulation is provided. In the substrate for flexible devices of the present invention, the adhesion of the glass layer is excellent by using a metal substrate or nickel-based substrate having a nickel plating layer on which an oxide film having irregularities is formed on the surface. Therefore, even when it is subjected to a roll-to-roll process, it has sufficient flexibility so that peeling does not occur.
In addition, in the present invention, since it has a glass layer capable of completely preventing the permeation of moisture with a dense structure, it has excellent moisture barrier properties and is effectively used as a substrate for organic EL-related. it can.
Furthermore, since the base layer that is the base for forming the electrode layer is formed on the glass layer, the adhesion of the electrode layer to the flexible device substrate is improved, and peeling of the electrode layer is effectively prevented. be able to.
Furthermore, according to the method for producing a flexible device substrate of the present invention, a flexible device substrate having no surface defects can be continuously produced, which is excellent in productivity and economy.

It is a figure which shows the cross-section of an example of the board | substrate for flexible devices of this invention. It is a figure which shows the cross-section of another example of the board | substrate for flexible devices of this invention. It is a figure which shows the cross-sectional structure of the board | substrate for organic EL devices using the board | substrate for flexible devices of this invention shown in FIG. It is a figure which shows the cross-sectional structure of the board | substrate for organic EL devices using the board | substrate for flexible devices of this invention shown in FIG. The base material No. of the nickel-plated steel sheet in Table 1 1, no. SEM photographs ((A) and (B)) of the surface of the nickel plating layer after calcination and base No. 6 It is a SEM photograph (C) of the nickel plating layer surface of 4. It is a TEM photograph ((A) and (B)) of the interface of a nickel plating layer and a glass layer about Example 12 and Comparative Example 1 in Table 5.

(Flexible device substrate)
The substrate for a flexible device of the present invention is a nickel-plated metal substrate or nickel-based substrate in which a nickel-plated layer is formed on at least one surface of a metal substrate, and the nickel-plated layer or nickel-based substrate. A substrate for a flexible device having a glass layer in which a bismuth-based glass having electrical insulation properties is formed in a layer shape, and an oxide film having irregularities on the surface is formed on the surface of the nickel plating layer or the surface of the nickel-based substrate. It is important that the bismuth-based glass is formed and that Bi ₂ O ₃ is contained in an amount of 70 to 84 wt%, ZnO is 10 to 12 wt%, and B ₂ O ₃ is 6 to 12 wt%. Features.
FIG. 1 is a diagram showing an example of a cross-sectional structure of a substrate for a flexible device according to the present invention using a nickel-plated metal base material in which a nickel-plated layer 11 is formed on the surface of a metal base material 10. A glass layer 13 is formed on the surface of the oxide film 11, and the surface of the oxide film 12 formed on the surface of the nickel plating layer 11 is formed as irregularities 12 a.

[Metal base material]
The metal base material for forming the nickel plating layer used in the flexible device substrate of the present invention is not limited to this, but iron, stainless steel, titanium, aluminum, copper, etc. can be used, and the thermal expansion coefficient is It is preferable to use those in the range of 8 × 10 ^{−6 to} 25 × 10 ⁻⁶ / ° C., particularly 10 × 10 ^{−6 to} 20 × 10 ⁻⁶ / ° C.
In the present invention, the metal substrate itself can be a nickel-based substrate, that is, a pure nickel plate or a nickel alloy plate, without forming a nickel plating layer. In the nickel alloy plate, iron (Fe), copper (Cu), or chromium (Cr) can be used as a metal that can be alloyed with nickel.
The thickness of the metal substrate or the nickel-based substrate is preferably in the range of 10 to 200 μm, particularly 20 to 100 μm, whereby sufficient flexibility can be obtained.

[Nickel plating layer]
In the flexible device substrate of the present invention, the nickel plating layer formed on the surface of the metal substrate is a layer formed by nickel plating, and may be either electrolytic plating or electroless plating as described later. In the example shown in FIG. 1, the nickel plating layer is formed only on one surface of the metal base material, but may of course be formed on both surfaces of the metal base material.
The thickness of the nickel plating layer is preferably in the range of 0.1 to 10 μm, particularly 0.5 to 5 μm, including the oxide film, and the thickness of the nickel plating layer is thinner than the above range. In addition, the adhesion of the glass layer becomes inferior compared with the case where it is in the above range, but on the other hand, even if the thickness of the nickel plating layer is thicker than the above range, no further effect can be expected, so that the economic efficiency is inferior. Become.
The nickel plating layer may have an alloy layer at the interface with the metal substrate.

[Oxide film]
As described above, in the present invention, it is an important feature that an oxide film having an uneven surface is formed on the surface of a nickel plating layer or a nickel-based substrate, and this oxide and glass react. Thus, an adhesion layer is formed, and the adhesion of the glass layer is improved. Therefore, the nickel metal present in the surface of the nickel plating layer or the surface of the nickel-based substrate is preferably 20 atomic% or less, particularly preferably 18 atomic% or less.
The oxide film is composed of at least nickel oxide formed by calcining the surface of the nickel plating layer or nickel-based substrate in an oxygen-containing atmosphere described later, but diffused from the nickel oxide and the metal substrate. You may consist of a metal oxide.
That is, when a steel plate is used as the metal material or when a nickel-iron alloy plate is used as the nickel-based substrate, it is desirable that iron be present in the nickel plating layer surface layer or the nickel-based substrate surface layer. Since the iron present in the surface layer is present as an oxide, the adhesion of the glass layer can be further improved in combination with the presence of the nickel oxide, so the iron present in the surface of the nickel plating layer or the surface of the nickel-based substrate. Of these, metallic iron is preferably 3 atomic% or less.

In addition, it is preferable that the ratio of oxygen in the surface of the nickel plating layer or the surface of the nickel-based substrate is in the range of 30 atomic% or more, and particularly in the range of 35 to 50 atomic%, whereby the oxide film has excellent adhesion to the glass layer. Is formed.
The amount of oxygen at the nickel plating layer or the interface between the nickel-based substrate and the glass layer (hereinafter, sometimes referred to as “(nickel plating layer / glass layer) interface”) is an arbitrary surface in the thickness direction of the glass layer (to be described later) , “Sometimes referred to as“ inside the glass layer ”) is 100%, preferably 80% or more, particularly 85 to 100%. That is, when the nickel plating layer or the nickel-based substrate has an oxygen amount close to the oxygen amount existing in the glass layer at the interface of the glass layer, the surface of the nickel plating layer or the nickel-based substrate is separated from the glass layer. It is thought that the anchor effect is received, and the interlayer adhesion at the interface is remarkably improved as is apparent from the results of the examples described later. In addition, the arbitrary surface in the thickness direction of the glass layer is almost affected by the outside except for the vicinity of the interface with the nickel plating layer or the surface of the nickel-based substrate and the vicinity of the surface that forms the underlayer described later. It means an arbitrary surface in the thickness direction of the glass layer in which the composition of the glass layer is almost the same on any arbitrary surface.

In the present invention, unevenness (rough surface) is formed by forming convex portions that are considered to be crystal grains on the surface of the oxide film, thereby suppressing the expansion of the glass composition during the formation of the glass layer. Thus, the occurrence of repelling is effectively suppressed.
The unevenness (surface roughness) on the oxide film surface has an arithmetic average roughness (Ra) of 30 to 100 nm, particularly 50 to 90 nm, and a maximum height roughness (Rz) of 420 to 900 nm, particularly 600 to It is desirable that it be formed to be in the range of 850 nm.
The thickness of the oxide film is preferably in the range of 40 to 1200 nm, preferably 500 to 1000 nm, more preferably 500 to 900 nm. When the thickness of the oxide film is thinner than the above range, the surface modification of the nickel plating layer or the nickel-based substrate may be insufficient as compared with the case where the oxide film is in the above range. When the thickness of the oxide film is thick, alloying of the nickel plating layer surface or the nickel-based substrate surface layer proceeds and the nickel plating layer surface layer or the nickel-based substrate surface layer becomes brittle as compared with the case where it is in the above range. There is a possibility that the nickel plating layer surface layer or the nickel-based substrate surface layer may be peeled off.

[Glass layer]
The substrate for a flexible device of the present invention has Bi ₂ O ₃ , ZnO, and B ₂ O ₃ as an insulating layer on the above-described nickel plating layer or oxide film having an uneven surface formed on a nickel-based substrate. A glass layer made of bismuth-based glass containing is formed.
Bismuth-based glass is known to have excellent moisture barrier properties and excellent adhesion to metal substrates. In the present invention, Bi ₂ O, which is the main component in such bismuth-based glass, is used. ₃ and ZnO and B ₂ O ₃ as essential components, and the compounding of these components is in the range around the eutectic point, thereby forming a glass network structure that is difficult to crystallize. In combination with the above, it is possible to provide a flexible device substrate in which the occurrence of repellency is effectively suppressed on the glass surface.
It is important that the bismuth-based glass contains Bi ₂ O _{3 in an amount} of 70 to 84% by weight, ZnO in an amount of 10 to 12% by weight, and B ₂ O _{3 in} an amount of 6 to 12% by weight. When the component is in the above range, crystallization of the glass layer is suppressed, and generation of repellency is effectively suppressed.

In the bismuth-based glass used in the present invention, in addition to the above essential components, SiO ₂ and / or Al ₂ O ₃ is further contained in an amount of 0 to ₂ % by weight of SiO _{2 and} 0 to 1% by weight of Al ₂ O _3. It is preferable that it is contained (not including the case where both SiO ₂ and Al ₂ O ₃ are zero). By blending at least one of these components, durability and the like are improved, and the glass layer can be stabilized.
Further, the bismuth-based glass used in the present invention has CuO and / or NiO in addition to the essential components described above in an amount of 0 to 2% by weight of CuO and 0 to 2% by weight of NiO (both CuO and NiO are present). (It does not include the case of zero), and by incorporating at least one of these components, the adhesion with the nickel plating layer is further improved, and the repelling suppression effect is further improved. Is done.
Furthermore, the bismuth-based glass used in the present invention contains 1.5% of any of Y ₂ O ₃ , ZrO ₂ , La ₂ O ₃ , CeO ₂ , TiO ₂ , CoO, and Fe ₂ O ₃ in addition to the essential components. It is preferable to contain it in an amount of not more than% by weight (excluding zero), whereby the durability of the glass can be improved, and the warp of the flexible device substrate can be effectively prevented. . In addition, although these components can also be used in combination of multiple types, in that case, the total amount is preferably 1.5% by weight or less.

  In the present invention, the thickness of the glass layer is preferably in the range of 2 to 45 μm. When the thickness of the glass layer is thinner than the above range, there is a possibility that unevenness due to the oxide film cannot be sufficiently smoothed compared with the case where it is in the above range, while when thicker than the above range, There exists a possibility that flexibility may be inferior compared with the case where it exists in the said range.

[Underlayer for electrode layer formation]
In the flexible device substrate of the present invention, an electrode layer such as an anode or a cathode can be directly formed on the surface of the glass layer, but preferably, nickel (Ni) is formed on the surface of the glass layer 13 as shown in FIG. ), Indium tin oxide (ITO), silver (Ag), gold (Au), copper (Cu), magnesium-silver (MgAg), gold-copper (AuCu), silver-copper (AgCu), zinc oxide (ZnO) From the viewpoint of adhesion of the electrode layer, it is preferable to form the underlayer 14 made of cobalt (Co), palladium (Pd), or the like.
This underlayer can exhibit excellent adhesion to all electrode layers made of aluminum (Al), silver (Ag), gold (Au), and alloys thereof used in organic EL substrates. When forming an electrode layer made of aluminum (Al) or silver (Ag), the underlayer is preferably made of nickel or indium tin oxide among the above metals or metal oxides.
The thickness of the underlayer is preferably in the range of 5 to 100 nm. If it is thinner than the above range, the adhesion of the electrode layer may not be sufficiently improved. On the other hand, even if it is thicker than the above range, further improvement in adhesion cannot be expected, and it is only economically inferior. It is.
In addition, since this base layer has excellent adhesion to all bismuth-based glasses having electrical insulation used for flexible device substrates, when the above-described specific bismuth-based glass is used. It is not limited, When this electrode layer is formed in the board | substrate for flexible devices, this base layer can be used conveniently.

(Method for manufacturing substrate for flexible device)
The substrate for flexible devices of the present invention includes a nickel plating layer obtained by firing a nickel plating metal substrate or a nickel-based substrate in which a nickel plating layer is formed on at least one surface of a metal substrate in an oxygen-containing atmosphere. Oxide film forming step for forming oxide film on surface or nickel base substrate surface Glass layer formation for forming bismuth glass layer containing Bi ₂ O ₃ , ZnO, B ₂ O ₃ on the oxide film It can manufacture with the manufacturing method containing a process.
Moreover, after the said glass layer formation process, it can also have the process of forming the base layer for forming the electrode layer which consists of nickel, indium tin oxide, etc. on the surface of a glass layer.

[Nickel plating layer forming process]
In the metal substrate for flexible devices of the present invention, the nickel plating layer forming method itself in the nickel-plated metal substrate can be performed by a conventionally known method.
In the nickel plating layer forming step, the treatment method differs depending on the metal substrate to be used. However, when using a steel plate as the metal substrate, degreasing is performed by alkaline electrolysis or the like prior to the plating treatment, washing with water, and sulfuric acid. A conventionally known pretreatment such as pickling by dipping or the like is performed.
As described above, a nickel plating layer can be formed on the pretreated metal substrate by a conventionally known plating method such as electrolytic plating or electroless plating. From the viewpoint of continuous productivity, electrolytic plating is preferred. As the nickel plating bath, a bath widely used such as a watt bath, a sulfamic acid bath or the like can be used under known electrolysis conditions according to a known formulation. In addition, as above-mentioned, it is preferable that a nickel plating layer is formed so that it may become thickness of 0.1-10 micrometers, especially 0.5-5 micrometers.

[Oxide film forming step]
In the manufacturing method of the substrate for flexible devices of the present invention, the surface of the nickel plating layer or the nickel-based substrate is obtained by calcining the surface of the nickel-plated metal substrate or the nickel-based substrate in an oxygen-containing atmosphere. It is important to form an oxide film having irregularities.
The calcination conditions are not particularly limited as long as the above-described oxide film is formed, but the calcination temperature is preferably 550 to 900 ° C, particularly 750 to 850 ° C. The calcining time can be appropriately changed depending on the oxygen concentration and calcining temperature of the oxygen-containing atmosphere. However, when calcining in the above temperature range in the atmosphere, the calcining temperature is calcined for 5 to 120 seconds. It is preferable to do. As described above, the oxide film is preferably formed to have a range of 40 to 1200 nm, preferably 500 to 1000 nm, and more preferably 500 to 900 nm.
It should be noted that an alloy layer may be formed on the surface of the nickel plating layer or the nickel-based substrate depending on the calcination conditions by firing for forming the oxide film in this step.

[Glass layer forming step]
Next, a bismuth-based glass layer containing Bi ₂ O ₃ , ZnO, B ₂ O ₃ is formed on the nickel plating layer on which the oxide film is formed.
The glass layer formation process is not limited to this procedure, but roughly speaking, a glass paste is prepared by mixing and dispersing glass powder and a vehicle, and this glass paste is formed on the oxide film on the surface of the nickel plating layer. It can be formed by baking after coating and drying.

<Preparation of glass paste>
The glass powder used for forming the glass layer is basically composed of Bi ₂ O ₃ , ZnO, B ₂ O _3. As described above, Bi ₂ O ₃ is 70 to 84% by weight, ZnO is 10 to 12% by weight, B A glass frit containing _{2 to 3 in} an amount of 6 to 12% by weight is used.
Further, as described above, in addition to the above essential components, the glass composition further includes SiO ₂ and / or Al ₂ O ₃ , SiO ₂ is 0 to 2 wt%, and Al ₂ O ₃ is from the viewpoint of glass stability. From the viewpoint of improving the adhesion with the nickel plating layer, CuO and / or NiO is 0 to 2% by weight of CuO and 0 to 2% by weight of NiO from the viewpoint of being contained in an amount of 0 to 1% by weight. From the viewpoint of improving the stability and preventing warping of the substrate after firing, Y ₂ O ₃ , ZrO ₂ , La ₂ O ₃ , CeO ₂ , TiO ₂ , CoO, Fe ₂ O It is preferable that any one of ₃ is contained in an amount of 1.5% by weight or less.

  The glass composition preferably has a softening point temperature in the range of 300 to 500 ° C. The bismuth-based glass that softens at a temperature lower than the above range is more susceptible to crystallization during the main firing than in the above range, and when it is necessary to perform the binder removal treatment, There is a risk of softening, and the decomposition gas of the binder may enter the glass and cause pinholes. On the other hand, when the softening point temperature is higher than the above range, a higher temperature is required at the time of main firing than in the above range, and film formation near the heat resistant temperature of nickel plating may be difficult. Further, if the main firing is performed at a relatively low temperature, the glass is not sufficiently melted and the surface smoothness may be lost.

The glass powder is obtained by mixing the above glass composition, heating at a temperature of 800 to 1200 ° C. to form a molten glass, rapidly cooling to obtain a glass frit, and then pulverizing by a JET pulverization method or the like. In order to obtain a smooth glass surface, it is desirable that the average particle size is 20 μm or less, preferably 1 to 10 μm, more preferably 1 to 5 μm. In the present invention, the average particle size of the glass powder is a value measured by a laser diffraction / scattering method.
The glass paste is obtained by uniformly mixing and dispersing the glass powder and the vehicle with a bead mill, a paint shaker, a roll or the like. Moreover, it can also be set as a dispersion liquid from a dispersible viewpoint.
As the vehicle, a conventionally known solvent-based or water-based vehicle can be used, and it is not limited to this, but the following organic binders and solvents can be exemplified.
Examples of the organic binder include, but are not limited to, cellulose resins such as methyl cellulose, ethyl cellulose, carboxymethyl cellulose, oxyethyl cellulose, benzyl cellulose, propyl cellulose, and nitrocellulose; methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-hydroxyethyl methacrylate, Examples thereof include organic resins such as acrylic resins obtained by polymerizing one or more acrylic monomers such as butyl acrylate and 2-hydroxyethyl acrylate; aliphatic polyolefin carbonate resins such as polypropylene carbonate.
The solvent is appropriately selected depending on the organic binder to be used, and is not limited to this. In the case of a cellulose resin, water, terpineol, butyl carbitol acetate, ethyl carbitol acetate, etc .; in the case of an acrylic resin, methyl ethyl ketone, terpineol, Solvents such as butyl carbitol acetate, ethyl carbitol acetate and the like; in the case of aliphatic polyolefin carbonates, propylene carbonate, triacetin and the like can be used.
Moreover, a well-known thickener, a dispersing agent, etc. can also be added to a glass paste according to a well-known prescription as needed.

<Coating / drying / firing of glass paste>
The prepared glass paste is applied onto the nickel plating layer by a coating method corresponding to the viscosity of the glass paste. Although it is not limited to this as a coating method, it can be performed by a bar coater, a die coater, a roll coater, a gravure coater, screen printing, etc., and the thickness of the formed glass layer is 2 to 45 μm, It is desirable to apply.
The coated glass paste is dried at a temperature of 80 to 180 ° C. After drying, if necessary, binder removal processing is performed. The binder removal treatment is preferably performed at a temperature of 180 to 450 ° C. for 10 minutes or more.
After drying, the coated surface subjected to the binder removal treatment as necessary is baked at a temperature of 550 to 900 ° C., preferably 650 to 850 ° C., for 10 to 300 seconds to form a glass layer. When the firing temperature is lower than the above range, the melting may be insufficient as compared with the case where it is within the above range. On the other hand, when the firing temperature is higher than the above range, In comparison, the nickel plating layer may be affected.

[Underlayer forming process]
In the flexible device substrate of the present invention, the electrode layer can be directly formed on the glass layer. However, as described above, it is preferable to form the base layer and form the electrode layer on the base layer.
The underlayer can be formed by a conventionally known method such as sputtering, vapor deposition, or CVD, using a metal or metal oxide that forms the underlayer such as nickel or indium tin oxide. Is preferred.
The sputtering conditions are not particularly limited, and can be performed under conventionally known conditions as long as an underlayer having a thickness in the range of 5 to 100 nm can be formed. Further, prior to the formation of the underlayer, it is preferable to clean the surface of the glass layer by a conventionally known cleaning / drying method.

(Organic EL device substrate)
FIG. 3 is a diagram showing a cross-sectional structure of an example of an organic EL device substrate using the flexible device substrate of the present invention shown in FIG.
The substrate for a flexible device indicated as 1 as a whole has an oxide film 12 having irregularities on the surface formed on the surface of one nickel plating layer 11a of the metal substrate 10 having nickel plating layers 11a and 11b formed on both sides. A glass layer 13 is formed on the oxide film 12.
The organic EL device substrate of the present invention indicated as a whole by 2 is an electrode layer (Ag, Al) 20 formed on the glass 13 layer of the flexible device substrate, an organic thin film light emitting formed on the electrode layer 20. 3 and at least the transparent electrode layer 22 formed on the organic thin-film light emitting layer 21, but in the specific example shown in FIG. 3, the transparent sealing layer 23 and the transparent sealing layer are formed on the transparent electrode layer 22. A stopper 24 is further laminated, and a corrosion-resistant layer 25 is laminated on the nickel plating layer 11b.
FIG. 4 is a view showing a cross-sectional structure of an organic EL device substrate formed by using a flexible device substrate 1 ′ in which a base layer 14 is formed on the glass 13 layer shown in FIG. 2.

(Substrate Nos. 1-11, 15)
1. Nickel-plated steel sheet [metal substrate]
As a metal base material, a steel sheet obtained by annealing and degreasing a cold rolled sheet (thickness 50 μm) of ordinary steel having the chemical composition shown below was prepared.
Composition: C; 0.03% by weight; Si; 0.01% by weight; Mn; 0.25% by weight; P; 0.008% by weight; S; 0.005% by weight; Al; 0.051% by weight; The balance; Fe and unavoidably contained components.
[Formation of nickel plating layer]
Next, the prepared steel sheet (size: length 12 cm, width 10 cm, thickness 50 μm) was subjected to alkaline electrolytic degreasing and sulfuric acid immersion pickling, and then subjected to nickel plating under the following conditions to obtain a thickness of 1 μm, surface roughness ( Ra) A nickel plating layer of 30.1 nm was formed on both sides.
Bath composition: nickel sulfate 300 g / L, nickel chloride 40 g / L, boric acid 35 g / L, pit inhibitor (sodium lauryl sulfate) 0.4 mL / L
pH: 4 to 4.6
Bath temperature: 55 ° C-60 ° C
Current density: 25 A / dm ²

(Substrate Nos. 12 to 14)
2. Pure Nickel Plate A pure nickel plate having a thickness of 100 μm was prepared as a nickel-based substrate.

3. Formation of Oxide Film Using the above nickel-plated steel plate and pure nickel plate, the base material No. 1-3, 5-7, and 15 nickel-plated steel plates and substrate Nos. 13 and 14 pure nickel plates were calcined using a thin steel plate heat treatment simulator (manufactured by Vacuum Riko Co., Ltd., product number: CCT-AV). Base No. 4 and 12 were not calcined for comparison. In addition, the base material No. About 8-11, it calcined in NH atmosphere.
The calcined nickel-plated steel sheet, substrate No. No. 4 nickel-plated steel sheet, calcined pure nickel sheet and substrate No. About 12 pure nickel plates, the arithmetic average roughness (Ra) and the maximum height roughness (Rz) as the surface roughness, and the thickness of the surface oxide were examined. The results are shown in Table 1.
In addition, the base material No. 1 and 6, the SEM photograph of the surface of the nickel plating layer after calcination, and the substrate No. A SEM photograph of the surface of the nickel plating layer 4 is shown in FIG.
In addition, about the thickness and surface roughness (Ra, Rz) of the oxide film of Table 1, it measured with the following method.
Arithmetic mean roughness (Ra) and maximum height roughness (Rz): Measured in SPM measurement mode of a microscope (Olympus, Nanosearch microscope, product number: OLS3500) according to JIS B 0601.
Oxide film thickness: Measured using a field emission Auger microprobe (AES: manufactured by JEOL Ltd., product number JAMP-9500F).

4). Measurement of base material surface layer by XPS For the surface layers of 1, 4, 6, 10, and 11, the ratio of carbon, oxygen, iron, and nickel (total 100 atomic%), the ratio of metallic iron and iron oxide (total 100 atomic%), and metallic nickel and nickel oxide (Total 100 atomic%) was measured using a scanning XPS microprobe (XPS apparatus, product number PHI5000 VersaProbe II manufactured by ULVAC-PHI). The results are shown in Table 2.

5. Confirmation of the presence of iron on the surface of the substrate The presence of iron was confirmed on the surface layers of the substrates 1, 4, 6, 12 to 14 using the scanning XPS microprobe. The results are shown in Table 3.

6). Formation of glass layer Degreasing process: Base No. 1-15 were used, and the surface of each base material was wiped off with gauze soaked in alcohol and degreased.
Coating film forming step: A vehicle in which an organic solvent and a binder were mixed was prepared, and the vehicle and the glass composition No. described in Table 4 were prepared. A to K bismuth glass frit was mixed in a mortar so that the weight ratio was 25:75, and dispersed with a ceramic roll to prepare a glass paste for coating film formation. And base material No. The glass paste for forming a coating film was applied to the surface of 1 to 15 with a bar coater so that the film thickness after firing was 20 μm to form a coating film.

(Examples 1-13, Comparative Examples 1-20)
7). Substrate evaluation for flexible devices (glass layer evaluation)
A substrate for flexible devices was prepared by combining the base material (base material No.) and the glass paste for coating film formation (glass composition No.) as shown in Table 5. The glass firing process uses an electric furnace to dry (temperature: 110 ° C., time: 20 minutes), binder removal (temperature: 330 ° C., time: 20 minutes), firing (temperature: 750 ° C., time: 15 seconds) It is.
About the obtained board | substrate for flexible devices, the presence or absence of the bubble in a glass layer, the presence or absence of a repellency, and the presence or absence of crystallization (burts) were evaluated as follows. The results are shown in Table 5.
Although the main cause of repelling is bubbles, there are also repellings other than those caused by bubbles. Therefore, the presence or absence of bubbles and the presence or absence of all repelling (including those caused by bubbles) were evaluated separately.
[Bubble evaluation]
In the bubble evaluation, for a flexible device substrate having a size of 100 × 100 mm, bubbles are generated when the focal point is moved from the surface of each base material (interface between the base material and the glass layer) toward the glass layer surface with an optical microscope. Judgment was made based on whether or not it could be confirmed.
[Repel evaluation]
For the evaluation of repelling, the number of repels that can be visually confirmed was evaluated according to the following evaluation criteria for the same flexible device substrate of 100 × 100 mm size.
◎: No repelling ○: Number of repelling less than 5 △: Number of repelling is 5 or more and less than 10 ×: Number of repelling is 10 or more [crystallization evaluation]
Crystallization evaluation evaluated the presence or absence of crystallization which can be visually confirmed about the board | substrate for flexible devices of the same 100x100 mm size.
[Comprehensive evaluation]
From the above-mentioned bubble evaluation, repellency evaluation and crystallization evaluation, comprehensive evaluation was performed according to the following criteria.
◎: No bubbles or repellency, no crystallization ○: Bubbles, repellency evaluation ◯, no crystallization △: Bubbles, repellency evaluation △, no crystallization △△: Bubbles, repellency evaluation △, crystallization ×: With bubbles, repelling evaluation ×, without crystallization XX: With bubbles, repelling evaluation ×, with crystallization

8). (Nickel plating layer / glass layer) interface oxygen amount For Example 12 and Comparative Example 1, the oxygen amount inside the glass layer (0.4 μm glass side from the (nickel plating layer / glass layer) interface) and (nickel The amount of oxygen at the interface of the plating layer / glass layer was measured using a TEM (field emission transmission electron microscope). Assuming that the oxygen content in the glass layer is 100%, the oxygen content at the (nickel plating layer / glass layer) interface was 89.1% in Example 12, whereas it was 75.3% in Comparative Example 1. . A TEM photograph of the (nickel plating layer / glass layer) interface of Example 12 is shown in FIG. 6 (A), and a TEM photograph of the (nickel plating layer / glass layer) interface of Comparative Example 1 is shown in FIG. 6 (B). .

(Experimental Examples 1-7)
Using the flexible device substrate of Example 12 above, the substrate was cut into small pieces of 20 mm × 20 mm, and the surface of the glass layer was cleaned by the following cleaning method. A base layer made of nickel and indium tin oxide (10% by weight of tin oxide) is formed on the cleaned glass layer surface in accordance with the following film formation method, and an electrode layer (anode) made of aluminum is formed on the base layer. did. The following evaluation was performed about the substrate for flexible devices after electrode formation. Table 6 below shows the types, thicknesses, film formation rates, and evaluation results of the base layer and the electrode layer.

[Cleaning method]
The detergent, ion-exchanged water, and alcohol were sequentially washed in that order and dried with a dryer.

[Film formation method]
(1) The cleaned flexile device substrate was set in an RF magnetron sputtering apparatus, and a vacuum was drawn up to 1 × 10 ⁻⁵ Pa level.
(2) Argon (Ar) was introduced so that the pressure in the film formation chamber was 0.3 Pa.
(3) A film was formed at a film formation rate shown in Table 6 for a predetermined time.

[Evaluation method]
Evaluation was performed by a tape peeling method for both the crosscut portion and the portion other than the crosscut portion.
The crosscut portion was cut by the crosscut method (conforming to JIS K5600-5-6) shown in (1) to (4) below, and the number of squares that were not peeled out of 25 squares after tape peeling was counted. For areas other than the cross cut portion, the presence or absence of peeling was evaluated.
(1) Using a cutter knife, cuts of a right-angle lattice pattern at intervals of 2 mm were formed on the film formation surface (25 mm at intervals of 2 mm).
(2) Adhesive tape (special acrylic adhesive 3M PPS-15) is attached on the lattice pattern, and is rubbed with a plastic eraser to adhere the adhesive tape.
(3) The adhesive tape is peeled off at an angle close to 60 degrees with respect to the test piece.
(4) The number of cells in the film formation area that was not peeled off by the adhesive tape was counted.

  The substrate for flexible devices of the present invention has excellent moisture barrier properties, insulating properties, surface smoothness and adhesion of glass layers, and as a substrate for organic EL lighting, organic EL displays, organic thin film solar cells, etc. It can be preferably used.

  DESCRIPTION OF SYMBOLS 1 Flexible device board | substrate, 2 Organic EL device board | substrate, 10 Metal base material, 11 Nickel plating layer, 12 Oxide film, 13 Glass layer, 14 Underlayer, 20 Electrode layer (Ag, Al), 21 Organic thin film light emitting layer , 22 Transparent electrode layer, 23 Transparent sealing layer, 24 Transparent sealing material, 25 Corrosion resistance layer.

Claims (20)

A nickel-plated metal substrate or nickel-based substrate having a nickel-plated layer formed on at least one surface of the metal substrate; and a bismuth-based glass having electrical insulation on the nickel-plated layer or nickel-based substrate. A substrate for a flexible device having a glass layer formed in a layer shape,
On the surface of the nickel plating layer or the surface of the nickel-based substrate, an oxide film having irregularities on the surface is formed,
The substrate for flexible devices, wherein the bismuth-based glass contains Bi ₂ O ₃ in an amount of 70 to 84% by weight, ZnO in an amount of 10 to 12% by weight, and B ₂ O ₃ in an amount of 6 to 12% by weight. The bismuth-based glass contains SiO ₂ and / or Al ₂ O ₃ , the amount of SiO ₂ is 0 to 2 wt%, and the content of Al ₂ O ₃ is 0 to 1 wt% (SiO ₂ and The substrate for flexible devices according to claim 1, which does not include a case where both of Al ₂ O ₃ are zero.   The bismuth-based glass contains CuO and / or NiO, the CuO content is 0 to 2% by weight, the NiO content is 0 to 2% by weight (including the case where both CuO and NiO are zero) The flexible device substrate according to claim 1 or 2, wherein: The bismuth-based glass is any one of Y ₂ O ₃ , ZrO ₂ , La ₂ O ₃ , CeO ₂ , TiO ₂ , CoO, and Fe ₂ O ₃ in an amount of 1.5% by weight or less (excluding zero). The board | substrate for flexible devices in any one of Claims 1-3 contained.   The substrate for flexible devices according to claim 1, wherein the surface of the oxide film has an arithmetic average roughness (Ra) in a range of 30 to 100 nm.   The substrate for flexible devices according to any one of claims 1 to 5, wherein a maximum height roughness (Rz) of the surface of the oxide film is in a range of 420 to 900 nm.   The substrate for flexible devices according to claim 1, wherein the oxide film has a thickness in a range of 40 to 1200 nm.   The substrate for flexible devices according to claim 1, wherein the glass layer has a thickness of 2 to 45 μm.   The board | substrate for flexible devices in any one of Claims 1-8 in which iron exists in the said nickel plating layer surface layer or a nickel-type base material surface layer.   The substrate for flexible devices according to claim 9, wherein metal iron is 3 atomic% or less among iron present on the surface of the nickel plating layer or the surface of the nickel-based substrate.   The board | substrate for flexible devices in any one of Claims 1-10 whose ratio of the oxygen in the said nickel plating layer surface layer or a nickel-type base material surface layer is 30 atomic% or more.   The board | substrate for flexible devices in any one of Claims 1-11 whose ratio of metallic nickel is 20 atomic% or less among the nickel which exists in the said nickel plating layer surface layer or a nickel-type base material surface layer.   The amount of oxygen at the interface between the glass layer and the nickel plating layer or the nickel-based substrate is 80% or more when the amount of oxygen on an arbitrary surface in the thickness direction of the glass layer is 100%. The board | substrate for flexible devices in any one.   The flexible layer according to any one of claims 1 to 13, wherein a layer serving as a base for forming an electrode layer is formed on a surface of the glass layer, and the base layer is made of nickel or indium tin oxide. Device substrate.   A nickel-plated metal substrate or nickel-based substrate having a nickel-plated layer formed on at least one surface of the metal substrate; and a bismuth-based glass having electrical insulation on the nickel-plated layer or nickel-based substrate. A flexible device substrate comprising: a glass layer formed in a layer shape; and a base layer serving as a base for forming an electrode layer on a surface of the glass layer.   The flexible device substrate according to claim 15, wherein the underlayer is made of any one of nickel, indium tin oxide, silver, gold, copper, magnesium-silver, gold-copper, silver-copper, zinc oxide, cobalt, and palladium. By oxidizing a nickel-plated metal substrate or nickel-based substrate with a nickel-plated layer formed on at least one surface of the metal substrate in an oxygen-containing atmosphere, the surface of the nickel-plated layer or nickel-based substrate is oxidized. An oxide film forming step for forming a material film;
A glass layer forming step of forming a bismuth-based glass layer containing Bi ₂ O ₃ , ZnO, B ₂ O ₃ on the oxide film;
The manufacturing method of the board | substrate for flexible devices characterized by including.   The manufacturing method of the board | substrate for flexible devices of Claim 17 which bakes the nickel plating layer or the nickel-type base-material surface at the temperature of 550-900 degreeC in the said oxide film formation process.   The said glass layer formation process WHEREIN: The bismuth type | system | group glass composition coated on the nickel plating layer or the nickel-type base material is baked at the temperature of 550-900 degreeC for 10-300 seconds, The claim 17 or 18 Manufacturing method of substrate for flexible device.   The flexible device substrate according to any one of claims 1 to 16, an electrode layer formed on the glass layer or the base layer of the flexible device substrate, and an organic formed on the electrode layer. An organic EL device substrate comprising a thin film light emitting layer and a transparent electrode layer formed on the organic thin film light emitting layer.