Wired base material

Abstract

Provided is a wiring-equipped substrate in which an opaque wiring electrode pattern is less likely to be visually recognized even from an oblique direction, and which has excellent conductivity and light transmittance. A wiring-equipped substrate having an opaque wiring electrode pattern on a transparent substrate, wherein a blackened layer containing a resin and a colorant is provided on the upper and side portions of the opaque wiring electrode pattern, and the line width W1 [μm] of the transparent substrate side of the opaque wiring electrode pattern, the line width W2 [μm] of the upper surface side of the opaque wiring electrode pattern, and the line width W3 [μm] of the blackened layer satisfy the following formula (1). W1 ≥ W3 > W2 (1).

Description

Technical Field

[0001] The present invention relates to a wired substrate having an opaque wired electrode pattern on at least one side of a transparent substrate and a method thereof for manufacturing the same, wherein a blackening layer is provided on the upper and side portions of the opaque wired electrode pattern. Background Technology

[0002] In recent years, touch panels, widely used as an input method, consist of a display unit such as a liquid crystal panel and a touch sensor that detects information input at a specific location. For the wiring electrodes used in touch sensors, transparent wiring electrodes are typically used to prevent them from being easily visible. However, in recent years, due to increased sensitivity and larger screen sizes, opaque wiring electrodes made of metallic materials have become increasingly common. Regarding opaque wiring electrodes made of metallic materials, there is a problem that they can be easily spotted due to their metallic luster. Therefore, as a method for forming a blackening layer to improve the visibility of the display screen, a metal blackening treatment method has been proposed. This method is for forming a blackening layer for an electromagnetic wave shielding filter for a display, which is at least composed of a transparent substrate, a copper mesh layer, and a blackening layer. The metal blackening treatment method includes a step of contacting a laminate containing at least a transparent substrate and a copper mesh layer with a metal blackening treatment liquid, which is a solution of hydrochloric acid containing tellurium, to form a blackening layer on the surface of the copper mesh layer (for example, see Patent Document 1). However, the aforementioned metal blackening treatment method suffers from the problem of decreased conductivity of the opaque wiring electrodes due to metal oxidation. To address this, a method for manufacturing a substrate with wiring electrodes that exhibits excellent conductivity and produces opaque wiring electrodes that are difficult to see has been proposed. This method includes: a step of forming an opaque wiring electrode pattern on at least one side of a transparent substrate; a step of coating a positive photosensitive light-shielding composition on one side of the transparent substrate; and a step of forming a light-shielding layer on the upper part of the opaque wiring electrode pattern by exposing and developing the positive photosensitive composition using the opaque wiring electrode pattern as a mask (for example, see Patent Document 2). Furthermore, an electrode film that exhibits excellent invisibility of the grid pattern and good image visibility has been proposed. This electrode film includes: a transparent substrate; a metal grid electrode disposed on a first main surface of the transparent substrate; and a black photoresist layer disposed on the upper surface and both sides of the fine lines constituting the grid of the metal grid electrode (for example, see Patent Document 3).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2008-147356

[0006] Patent Document 2: International Publication No. 2018 / 168325

[0007] Patent Document 3: International Publication No. 2019 / 44339 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The method disclosed in Patent Document 2 can suppress the visibility issues caused by the metallic luster of the opaque wiring electrode pattern. While the opaque wiring electrode pattern is not easily visible when viewed from the front, the exposed electrodes on the sides of the pattern make the luster easily visible when viewed from an angle. The thicker the opaque wiring electrode pattern is made to improve conductivity, the more pronounced this problem becomes, making it difficult to simultaneously achieve both reduced visibility and improved conductivity. Furthermore, the electrode film disclosed in Patent Document 3 tends to have decreased light transmittance because the opaque area (metal electrode grid and blackening layer) occupies a larger area within the transparent substrate due to the formation of a blackening layer on the sides. In recent years, from the perspective of increasing the brightness of the touch panel display, there is a demand for improved light transmittance in wiring substrates.

[0010] Therefore, the object of the present invention is to provide a wired substrate that is not easily visible even from an oblique direction, and has excellent conductivity and light transmittance.

[0011] Methods for solving problems

[0012] To address the aforementioned issues, the present invention primarily comprises the following components.

[0013] <1> A wiring substrate having an opaque wiring electrode pattern on a transparent substrate, wherein a blackening layer containing resin and colorant is provided on the upper and side portions of the opaque wiring electrode pattern, and the line width W1 [μm] on the transparent substrate side of the opaque wiring electrode pattern, the line width W2 [μm] on the upper surface side of the opaque wiring electrode pattern, and the line width W3 [μm] of the blackening layer satisfy the following relationship (1).

[0014] W1≥W3>W2(1)

[0015] <2> As described in <1>, the wiring substrate has a black layer on the transparent substrate side of the aforementioned opaque wiring electrode pattern.

[0016] <3> The wiring substrate described in claim <1> or <2>, wherein the thickness T1 [μm] of the aforementioned opaque wiring electrode pattern is 1.0 to 10.0.

[0017] A method for manufacturing a wired substrate as described in any one of <4> <1> to <3>, the method comprising: a step of forming an opaque wired electrode pattern with a line width W1 [μm] on the transparent substrate side and a line width W2 [μm] on the upper surface side on a transparent substrate.

[0018] The process of forming a black photosensitive layer by coating a positive photosensitive resin composition comprising resin and colorant onto the aforementioned opaque wiring electrode pattern forming surface of the aforementioned transparent substrate; and

[0019] The process involves exposing and developing the aforementioned black photosensitive layer using the aforementioned opaque wiring electrode pattern as a mask, thereby forming a blackened layer with a linewidth of W3 [μm] on the upper and side portions of the opaque wiring electrode pattern.

[0020] Invention Effects

[0021] The wire substrate of the present invention is not easily visible even from an oblique direction, and has excellent conductivity and light transmittance. Attached Figure Description

[0022] Figure 1 A schematic diagram illustrating an example of the structure of the wiring substrate of the present invention.

[0023] Figure 2 A schematic diagram illustrating another example of the construction of the wiring substrate of the present invention.

[0024] Figure 3 This is a schematic diagram illustrating an example of an opaque wiring electrode pattern and a blackening layer in this invention.

[0025] Figure 4 This is a schematic diagram illustrating the electrode patterns used for evaluating conductivity, visibility, and light transmittance in the embodiments and comparative examples.

[0026] Figure 5 This is a schematic diagram of the mesh pattern of the negative mask used in the embodiments and comparative examples.

[0027] Figure 6 This is a schematic diagram of the grid pattern of the positive mask used in the embodiments and comparative examples. Detailed Implementation

[0028] In the wiring substrate of the present invention, an opaque wiring electrode pattern is formed on a transparent substrate, wherein a blackening layer is formed on the upper and side portions of the opaque wiring electrode pattern. The blackening layer comprises a resin and a colorant, and has the function of suppressing light reflection and light scattering of the opaque wiring electrode pattern, making it difficult to see. By having a blackening layer on the upper and side portions of the opaque wiring electrode pattern, the wiring substrate is made difficult to see not only when viewed from the front, but also when viewed from an oblique direction.

[0029] Furthermore, a transparent protective layer can be provided on the aforementioned components. This transparent protective layer protects the opaque wiring electrodes and the surface of the blackened layer, suppressing damage. Here, "transparent" in this invention refers to a transmittance of 50% or more at a wavelength of 550 nm, and "opaque" refers to a transmittance of less than 50% at a wavelength of 550 nm. It should be noted that the transmittance at a wavelength of 550 nm can be measured using a UV-Vis spectrophotometer (U-3310: manufactured by Hitachi High-Technologies Corporation). Additionally, in this invention, the transparent substrate side with the wiring substrate is designated as "lower," and the side opposite to the transparent substrate relative to the opaque wiring electrodes is designated as "upper."

[0030] Figure 1 The diagram shows a schematic representation of an example of the structure of the wiring substrate of the present invention. The wiring substrate 4 has an opaque wiring electrode pattern 2 on a transparent substrate 1, and a blackening layer 3 is provided on the upper and side portions of the opaque wiring electrode pattern 2. Figure 2 The diagram shows another example of the structure of the wiring substrate of the present invention. The wiring substrate 4 has an opaque wiring electrode pattern 2 on a transparent substrate 1, and a blackening layer 3 is provided on the upper and side portions of the opaque wiring electrode pattern 2. The opaque wiring electrode pattern 2 has a base layer (black layer) 5 on the transparent substrate 1 side.

[0031] In this invention, the line width W1 [μm] on the transparent substrate side of the opaque wiring electrode pattern, the line width W2 [μm] on the upper surface side of the opaque wiring electrode pattern, and the line width W3 [μm] of the blackening layer satisfy the following relationship (1).

[0032] W1≥W3>W2(1).

[0033] That is, in the opaque wiring electrode pattern, the linewidth W1 on the transparent substrate side (bottom surface) is greater than the linewidth W2 on the upper surface side (upper surface), resulting in a so-called conical cross-section. Furthermore, the linewidth W3 of the blackening layer refers to the maximum width of the blackening layer's linewidths, which is less than or equal to the linewidth W1 on the transparent substrate side (bottom surface) of the opaque wiring electrode pattern. In other words, the blackening layer does not form a conical cross-section following the opaque wiring electrode pattern. Additionally, since the blackening layer exists on the side of the opaque wiring electrode pattern, its linewidth W3 is greater than W2. Here, the linewidth, if the opaque wiring electrode pattern is linear, refers to the width in the direction perpendicular to the major axis (minor axis direction), and W1, W2, and W3 are measured in the same direction. Furthermore, regarding the linewidth of the blackening layer, even when a portion of it contains the opaque wiring electrode pattern, it refers to the overall width from one end of the blackening layer to the other. It should be noted that, as described later, when the pattern of the opaque wiring electrode has a base layer in a portion of it (the transparent substrate side), the linewidth W1 [μm] of the transparent substrate side of the opaque wiring electrode pattern refers to the linewidth of the base layer in contact with the transparent substrate. Furthermore, when the opaque wiring electrode pattern has a dome shape, the vertex of the dome shape is taken as the linewidth W2 on the upper surface side, and set to 0 μm.

[0034] Figure 3 The diagram shows a schematic representation of an example of an opaque wiring electrode pattern and a blackening layer according to the present invention. The opaque wiring electrode pattern 2 on a transparent substrate 1 has a tapered shape with a linewidth W1 on the transparent substrate side and a linewidth W2 on the upper surface side. A blackening layer 3 with a linewidth W3 is provided on the upper surface and side surfaces of the opaque wiring electrode pattern 2. Figure 3In this invention, the outer periphery of the blackening layer 3 forms a rectangle with three sides, but the blackening layer 3 can also have a conical shape within the range of satisfying the aforementioned formula (1). As described above, by having a blackening layer on the upper and side portions of the opaque wiring electrode pattern, the opaque wiring electrode pattern can be made difficult to see not only when viewed from the front but also when viewed from an oblique direction. According to the research of the inventors of this application, when the blackening layer covers the entire upper and side portions of the opaque wiring electrode pattern as disclosed in Patent Document 3, that is, when the line width W3 of the blackening layer is larger than the line widths W1 and W2 of the opaque wiring electrode pattern, the light transmittance of the wiring substrate decreases. In this invention, by making the line width W3 of the blackening layer less than or equal to the line width W1 on the transparent substrate side of the opaque wiring electrode pattern, the light transmittance of the wiring substrate can be improved. To ensure the blackening layer is formed in a manner that satisfies the aforementioned conditions, it is preferable that the opaque wiring electrode pattern has a tapered cross-section. By making the linewidth W1 on the transparent substrate side greater than the linewidth W2 on the upper surface side, even if a sufficiently thick blackening layer is formed to make the sides less visible, the cross-sectional area of ​​the opaque wiring electrode pattern can be increased, thereby improving conductivity. Here, each linewidth can be measured by magnifying and observing a randomly selected cross-section along the short axis of the opaque wiring electrode pattern and the blackening layer using a scanning electron microscope (SEM).

[0035] From the viewpoint of sufficiently suppressing reflection at the side of the opaque wiring electrode pattern, the difference between the linewidth W1 of the opaque wiring electrode pattern and the linewidth W3 of the blackening layer is preferably 0.3 μm or less, more preferably 0.1 μm or less, and even more preferably W1 = W3.

[0036] From the viewpoint of forming a sufficiently wide blackening layer on the side of the opaque wiring electrode pattern, and making the opaque wiring electrode pattern less visible even from an oblique direction, the difference between the linewidths W1 and W2 of the opaque wiring electrode pattern is preferably 0.1 μm or more. On the other hand, from the viewpoint of further improving conductivity, the difference between the linewidths W1 and W2 of the opaque wiring electrode pattern is preferably 2.0 μm or less, more preferably 1.5 μm or less.

[0037] Regarding the opaque wiring electrode pattern and blackening layer that satisfy the aforementioned formula (1), for example, they can be easily formed by the manufacturing method of the wiring substrate described later.

[0038] (Transparent substrate)

[0039] The transparent substrate preferably has transmittance to the exposure light used in the blackening layer formation step of the manufacturing method of the wire-lined substrate described later. Specifically, the transmittance at a wavelength of 365 nm is preferably 50% or more, more preferably 70% or more. By ensuring that the transmittance at a wavelength of 365 nm is 50% or more, the positive photosensitive resin composition can be exposed efficiently and effectively in the blackening layer formation step described later. It should be noted that the transmittance of the transparent substrate at a wavelength of 365 nm can be measured using a UV-Vis spectrophotometer (U-3310: manufactured by Hitachi High-Technologies Corporation).

[0040] Transparent substrates may or may not be flexible. Examples of non-flexible transparent substrates include quartz glass substrates, soda-lime glass substrates, alkali-free glass substrates, chemically strengthened glass substrates, "Pyrex" glass substrates, synthetic quartz sheets, epoxy resin substrates, polyetherimide resin substrates, polyetherketone resin substrates, and polysulfone resin substrates. Examples of flexible transparent substrates include polyester films such as polyethylene terephthalate films (hereinafter referred to as "PET films"), cyclic olefin polymer films, polyimide films, aramid films, and optical resin sheets. Multiple sheets can be stacked and used; for example, multiple transparent substrates can be bonded together using an adhesive layer. Furthermore, inorganic films and insulating layers can also be present on the surface of these transparent substrates. Examples of inorganic films include films of silicon dioxide and niobium pentoxide. By having an inorganic film on the transparent substrate, the adhesion between the transparent substrate and the opaque wiring electrode pattern can be improved.

[0041] The thickness of the transparent substrate can be appropriately selected depending on the material, within a range that allows for stable support of the opaque wiring electrode pattern while maintaining the aforementioned transmittance. For example, from the viewpoint of more stably supporting the opaque wiring electrode pattern, a thickness of 0.3 mm or more is preferred in the case of a non-flexible transparent substrate, and 25 μm or more is preferred in the case of a flexible transparent substrate. On the other hand, regarding the thickness of the transparent substrate, from the viewpoint of further improving the transmittance of exposure light, a thickness of 1.5 mm or less is preferred in the case of a non-flexible transparent substrate, and 300 μm or less is preferred in the case of a flexible transparent substrate.

[0042] (Opaque wiring electrode pattern)

[0043] It is preferable that the transmittance of the opaque wiring electrode pattern at a wavelength of 550 nm is 25% or less. Furthermore, it is preferable that the pattern has light-shielding properties against the exposure light used in the blackening layer formation process of the wiring substrate manufacturing method described later. Specifically, the transmittance at a wavelength of 365 nm is preferably 15% or less. By setting the transmittance at a wavelength of 365 nm to 15% or less, the mask function can be improved in the blackening layer formation process described later, and the desired blackening layer can be formed with better processability. It should be noted that the transmittance of the opaque wiring electrode pattern can be measured using a micro-area spectrophotometer (VSS 400: manufactured by Nippon Denshoku Kogyo Co., Ltd.) for opaque wiring electrode patterns larger than 0.1 mm square.

[0044] Examples of conductive materials used to form the opaque wiring electrode pattern include metals such as silver, gold, copper, platinum, lead, tin, nickel, aluminum, tungsten, molybdenum, chromium, titanium, and indium, as well as their alloys. Two or more of these materials can be used. From the viewpoint of conductivity, silver and copper are preferred.

[0045] The opaque wiring electrode pattern may also contain the aforementioned conductive material and organic components. For example, the opaque wiring electrode pattern may be formed from a cured product of a photosensitive conductive composition comprising conductive particles, an alkali-soluble resin, and a photopolymerization initiator. In this case, the opaque wiring electrode pattern contains the photopolymerization initiator and / or its photodegradation products. The photosensitive conductive composition may also contain additives such as thermosetting agents and leveling agents, as needed.

[0046] Examples of patterns for opaque wiring electrode patterns include, for example, grid patterns and strip patterns. Examples of grid patterns include lattice patterns with unit shapes such as triangles, quadrilaterals, polygons, and circles, or lattice patterns formed from combinations of these unit shapes. Among these, a grid pattern is preferred from the viewpoint of ensuring uniform conductivity of the pattern. An opaque wiring electrode pattern is more preferably a metal grid made of the aforementioned metal and having a grid pattern.

[0047] From the viewpoint of further improving conductivity, the thickness T1 [μm] of the opaque wiring electrode pattern is preferably 1.0 or more, and more preferably 1.5 or more. As mentioned above, the tendency for the electrode gloss on the side of the opaque wiring electrode pattern to be easily seen when viewing the wiring substrate from an oblique direction becomes more pronounced as the thickness of the opaque wiring electrode pattern increases. In the present invention, since a blackening layer is provided on the upper and side portions of the opaque wiring electrode pattern, the thicker the opaque wiring electrode pattern, the more significantly it will have the effect of making it less visible. On the other hand, from the viewpoint of forming finer wiring, the thickness T1 [μm] of the opaque wiring electrode pattern is preferably 10.0 or less, more preferably 5.0 or less, and even more preferably 3.0 or less. It should be noted that T1 can be measured using a stylus-type profilometer.

[0048] From the viewpoint of further improving conductivity, the linewidths W1 and W2 of the opaque wiring electrode pattern are preferably 1 μm or more, more preferably 1.5 μm or more, and even more preferably 2 μm or more. On the other hand, from the viewpoint of making the opaque wiring electrode pattern less visible, the linewidth W1 of the opaque wiring electrode pattern is preferably 10 μm or less, more preferably 8 μm or less.

[0049] From the viewpoints of making the opaque wiring electrode pattern less visible and improving light transmittance, the proportion of the area in the overall transparent substrate where the opaque wiring electrode pattern is formed is preferably 20% or less, more preferably 15% or less. By stacking two or more layers of the opaque wiring electrode pattern through a transparent protective layer, the proportion of the area where the opaque wiring electrode pattern is formed can be reduced while maintaining conductivity, making it less visible.

[0050] The pattern of the opaque wiring electrode can also have a base layer on the transparent substrate side. Examples of base layers include a black layer and an adhesive layer. By having a black layer on the transparent substrate side of the opaque wiring electrode pattern, the transparent substrate side of the pattern can be blackened, making the opaque wiring electrode pattern less visible even when viewing the wiring substrate from the back (transparent substrate side). Furthermore, by having an adhesive layer on the transparent substrate side of the opaque wiring electrode pattern, the adhesion between the transparent substrate and the opaque wiring electrode pattern can be improved. Two or more layers can also be stacked.

[0051] Preferably, the substrate layer has light-shielding properties against the exposure light used in the blackening layer formation step of the method for manufacturing the wiring substrate described later. Examples of substrate layers with light-shielding properties include layers formed from materials that highly reflect and absorb exposure light, and metal layers with a large refractive index difference from the transparent substrate. In the case of metal layers with a large refractive index difference from the transparent substrate, even if the metal layer itself transmits exposure light, the exposure light can be attenuated through reflection at the interface with the transparent substrate, thereby improving light-shielding properties.

[0052] Examples of materials constituting the black layer include copper oxide, copper nitride, and nickel. Examples of materials forming the adhesive layer include chromium, titanium, and their alloys. From the viewpoint of improving the adhesion between the opaque wiring electrode pattern and the transparent substrate and suppressing the peeling of the opaque wiring electrode pattern, an adhesive layer is preferred. From the viewpoint of making the opaque wiring electrode pattern difficult to see even when viewing the wiring substrate from the back side, a black layer is preferred.

[0053] (Blackening layer)

[0054] The blackening layer comprises resin and colorant. By including colorant in the blackening layer, reflections caused by the metallic luster of the opaque wiring electrode pattern can be suppressed, making the opaque wiring electrode pattern less visible. Furthermore, by including resin in the blackening layer, surface reflections of the colorant can be suppressed, further reducing the visibility of the blackening layer.

[0055] Examples of colorants include inorganic pigments, organic pigments, and dyes. Two or more of these may also be included. Among these, pigments are preferred for their excellent weather resistance. More specifically, examples include substances exemplified as colorants in International Publication No. 2018 / 168325, soluble azo pigments, insoluble azo pigments, metal complex salt azo pigments, phthalocyanine pigments, fused polycyclic pigments, and other organic pigments; iron oxides such as pine soot, ultramarine, iron black, hematite, goethite, and magnetite; and inorganic pigments such as titanium, chromium, lead, and their metal complexes. Among these, carbon black is preferred from the viewpoint of ease of acquisition, and titanium nitride and zirconium nitride are preferred from the viewpoint of light transmittance.

[0056] Examples of resins include phenolic resins, polyimide resins, acrylic resins, Cardo resins, epoxy resins, melamine resins, urethane resins, silicone resins, fluorinated resins, polyamide resins, polyvinyl ether resins, vinyl acetate / vinyl chloride copolymers, modified polyolefin resins, natural rubber, and synthetic rubber. Two or more of these can be used.

[0057] In the blackening layer formation step of the method for manufacturing the wiring substrate described later, when the pattern is formed by photolithography, an alkali-soluble resin is preferred as the resin. Examples of alkali-soluble resins include resins having hydroxyl and / or carboxyl groups. Among these, resins having phenolic hydroxyl groups are preferred. Examples of resins having phenolic hydroxyl groups include, for example, phenol-Novolac resins, cresol-Novolac resins, polymers of monomers having phenolic hydroxyl groups, and copolymers of monomers having phenolic hydroxyl groups with styrene, acrylonitrile, acrylic acid monomers, etc. Two or more of these may be contained.

[0058] (Transparent protective layer)

[0059] From the viewpoint of suppressing short circuits between opaque wiring electrode patterns, it is preferable that the transparent protective layer has insulating properties. For example, the material exemplified as an insulating layer in International Publication No. 2018 / 168325 can be cited as an example of such an insulating transparent protective layer.

[0060] (Manufacturing method of wiring substrate)

[0061] Next, a method for manufacturing the wired substrate of the present invention will be described. The method for manufacturing the wired substrate of the present invention includes: a step of forming an opaque wired electrode pattern with a line width W1 [μm] on the transparent substrate side and a line width W2 [μm] on the upper surface side on a transparent substrate (hereinafter, sometimes abbreviated as "opaque wired electrode pattern forming step"); a step of forming a black photosensitive layer on the aforementioned opaque wired electrode pattern forming surface of the aforementioned transparent substrate (hereinafter, sometimes abbreviated as "black photosensitive layer forming step"); and a step of forming a blackening layer on the upper and side portions of the opaque wired electrode pattern by exposing and developing the aforementioned black photosensitive layer using the aforementioned opaque wired electrode pattern as a mask (hereinafter, sometimes abbreviated as "blackening layer forming step"). In the process of forming an opaque wiring electrode pattern, an opaque wiring electrode pattern with a cone shape is formed, wherein the linewidth W1 [μm] on the transparent substrate side and the linewidth W2 [μm] on the upper surface side satisfy the relationship of the aforementioned formula (1). In the process of forming a blackening layer, when the black photosensitive layer is exposed using the cone-shaped opaque wiring electrode pattern as a mask, the exposure light is blocked within the range of the linewidth W1 on the transparent substrate side of the cone-shaped opaque wiring electrode pattern, thus making it easy to form. Figure 3 The blackening layer with the shape shown and the line width W3 [μm] satisfies the aforementioned formula (1) is therefore preferred.

[0062] (Opaque wiring electrode pattern formation process)

[0063] First, in the process of forming the opaque wiring electrode pattern, an opaque wiring electrode pattern is formed on at least one side of a transparent substrate. Alternatively, the opaque wiring electrode pattern can be formed on both sides of the transparent substrate. In this case, the opaque wiring electrode patterns formed on both sides, sandwiching the transparent substrate, are both located in an "upper" position relative to the transparent substrate located in the "lower" position in this invention.

[0064] Examples of methods for forming opaque wiring electrode patterns include: forming patterns using the aforementioned photosensitive conductive composition and photolithography; forming patterns using a conductive composition (conductive paste) and screen printing, gravure printing, inkjet printing, etc.; forming films of metals, metal composites, metal-metal compound composites, metal alloys, etc., and forming patterns using a photoresist; and transferring opaque wiring electrode patterns formed on a release film using the aforementioned photosensitive conductive composition and photolithography onto a transparent substrate, etc. Here, a release film refers to a film having a release layer on its surface. Examples of release agents forming the release layer include, for example, non-silicone release agents and silicone release agents. When opaque wiring electrode patterns are formed on both sides of a transparent substrate, or when two or more layers of opaque wiring electrode patterns are formed with a transparent protective layer in between, each opaque wiring electrode pattern can be formed using the same method, or different methods can be combined.

[0065] When an opaque wiring electrode pattern with a base layer is formed on the transparent substrate side, for example, a method can be used to form a metal, metal composite, metal-metal compound composite, metal alloy, etc., after forming a film of a material constituting the base layer on the transparent substrate, and then forming the pattern in one step or sequentially using a photolithography method with a photoresist.

[0066] When a pattern formed from a photosensitive conductive composition exhibits conductivity upon heat curing, heat curing at 140–500°C is preferred.

[0067] As a method to make the linewidth W1 [μm] on the transparent substrate side of the opaque wiring electrode pattern greater than the linewidth W2 [μm] on the upper surface side, for example, when forming a pattern using a photosensitive conductive composition by photolithography, a method can be used to widen the exposure gap between the photomask and the photosensitive conductive composition during exposure. In this case, the exposure gap is preferably 10 μm or more, more preferably 30 μm or more. On the other hand, from the viewpoint of improving the straightness of the pattern after development, the exposure gap is preferably 100 μm or less, more preferably 70 μm or less. In addition, when a pattern is formed on a release film using a photosensitive conductive composition by photolithography and then transferred to a transparent substrate, the pattern formed on the release film is made into an inverse cone shape and transferred to the transparent substrate, thereby making the linewidth W1 [μm] on the transparent substrate side greater than the linewidth W2 [μm] on the upper surface side. If a negative photosensitive conductive composition is used, an inverse cone shape pattern can be easily formed. Furthermore, when forming films of metals, metal composites, metal-metal compound composites, metal alloys, etc., and using photoresist to form patterns, since the metal film is etched not only in the vertical direction but also in the horizontal direction, there is a tendency for the linewidth W1 [μm] on the transparent substrate side to be larger than the linewidth W2 [μm] on the upper surface side. Additionally, when forming opaque wiring electrode patterns with a substrate layer, by selecting a material that requires a longer etching time than the metal film as the substrate layer material, it is possible to form a pattern in such a way that the linewidth W1 [μm] on the transparent substrate side of the substrate layer is larger than the linewidth W2 [μm] on the upper surface side of the opaque wiring electrode pattern.

[0068] (Black photosensitive layer formation process)

[0069] Next, in the black photosensitive layer formation process, a black photosensitive layer is formed on the opaque wiring electrode pattern forming surface of the transparent substrate. Here, the so-called black photosensitive layer is equivalent to the precursor of the blackened layer obtained by the blackening layer formation process. As a method for forming a black photosensitive layer on the opaque wiring electrode pattern forming surface of the transparent substrate, examples include a method of coating a positive photosensitive resin composition containing a resin and a colorant, and a method of transferring a black photosensitive layer formed on a release film onto a transparent substrate. Among these, from the viewpoint of forming a blackened layer of sufficient width on the electrode side, the coating method is preferred. As the resin and colorant, the aforementioned substances can be cited. As a method of coating a positive photosensitive resin composition containing a resin and a colorant, examples include spin coating using a spin coater, spray coating, roller coating, screen printing, and coating using a slot coater, doctor blade coater, die coater, calender coater, liquid surface bending coater, bar coater, etc.

[0070] A positive photosensitive resin composition refers to a composition that exhibits positive photosensitivity, with the light-exposed portion dissolving in the developer. It preferably contains a photosensitizer (dissolution inhibitor) and an alkali-soluble resin. Furthermore, without compromising the desired properties, it may also contain plasticizers, leveling agents, surfactants, rust inhibitors, crosslinking agents, silane coupling agents, defoamers, stabilizers, etc. Additionally, it is preferable to contain a solvent capable of adjusting the viscosity of the positive photosensitive resin composition to the desired range.

[0071] Examples of alkali-soluble resins and photosensitizers (dissolution inhibitors) included in International Publication No. 2018 / 168325 as positive photosensitive compositions include alkali-soluble resins and photosensitizers (dissolution inhibitors). The content of the alkali-soluble resin in the black photosensitive layer is preferably 45-65% by mass. The content of the photosensitizer (dissolution inhibitor) in the black photosensitive layer is preferably 5-25% by mass.

[0072] (Blackening layer formation process)

[0073] Next, in the blackening layer formation process, the black photosensitive layer is exposed and developed using an opaque wiring electrode pattern as a mask, thereby forming a blackening layer on the upper and side portions of the opaque wiring electrode pattern. As described above, by using a tapered opaque wiring electrode pattern with a linewidth W1 [μm] larger on the transparent substrate side than on the upper surface side as a mask for exposure, no exposure light is irradiated at the portion of the black photosensitive layer corresponding to the linewidth W1 [μm] of the opaque wiring electrode pattern on the transparent substrate side. Therefore, for portions where the linewidth of the opaque wiring electrode is smaller than the linewidth W1 [μm] of the opaque wiring electrode pattern on the transparent substrate side, a blackening layer can be formed on the side.

[0074] Examples of suitable exposure light sources include mercury lamps, halogen lamps, xenon lamps, LED lamps (365nm, 405nm), semiconductor lasers, and KrF or ArF excimer lasers. Among these, mercury lamps with i-line wavelengths (365nm) and LED lamps (365nm, 405nm) are preferred, and LED lamps (365nm) are even more preferred from the perspective of high output. The exposure light can be applied while the substrate is stationary, or it can be applied while the substrate is being transported to the light source in a direction opposite to the surface where the black photosensitive layer is formed.

[0075] By developing the exposed black photosensitive layer, the exposed portion can be removed, and a blackened layer can be formed on the unexposed portion of the upper and side parts of the opaque wiring electrode pattern.

[0076] As the developer, a material that does not impede the conductivity of the electrode pattern is preferred, and an alkaline developer is preferred. Examples of alkaline developers include those exemplified in International Publication No. 2018 / 168325. Examples of developing methods include: spraying the developer onto the surface of the black photosensitive layer while the substrate is stationary or rotating; immersing the black photosensitive layer in the developer; applying ultrasound while immersing the black photosensitive layer in the developer, etc.

[0077] The blackened layer obtained by development can be subjected to a rinsing process based on a rinsing solution. For example, the liquid exemplified as a rinsing solution in International Publication No. 2018 / 168325 can be cited.

[0078] The obtained substrate with wiring can be further heated at 100°C to 300°C. Heating increases the hardness of the blackened layer, suppresses defects and peeling caused by contact with other components, and further improves the adhesion between the substrate and the wiring. Examples of heating methods include heating using an oven, an inert oven, a heating plate, or electromagnetic waves using an infrared heater.

[0079] (Transparent protective layer formation process)

[0080] In the case where the wiring substrate of the present invention also has a transparent protective layer, it is preferable to form the transparent protective layer after the blackening layer is formed. Examples of methods for forming the transparent protective layer include: coating a transparent resin composition and drying it; transferring a transparent resin layer formed on a release substrate; attaching a transparent adhesive film to the opaque wiring electrode forming surface, etc.

[0081] Example

[0082] The present invention will be further described in detail below with reference to embodiments, but the present invention is not limited thereto. The materials used in each embodiment are shown below.

[0083] (Manufacturing Example 1: Acrylic resin with carboxyl groups)

[0084] 150 g of diethylene glycol monoethyl ether acetate (hereinafter referred to as "DMEA") was added to a reaction vessel under a nitrogen atmosphere, and the temperature was raised to 80°C using an oil bath. Over 1 hour, a mixture comprising 20 g of ethyl acrylate (hereinafter referred to as "EA"), 40 g of 2-ethylhexyl methacrylate (hereinafter referred to as "2-EHMA"), 20 g of styrene (hereinafter referred to as "St"), 15 g of acrylic acid (hereinafter referred to as "AA"), 0.8 g of 2,2'-azobisisobutyronitrile, and 10 g of DMEA was added dropwise. After the dropwise addition was complete, the mixture was stirred for another 6 hours to carry out the polymerization reaction. Then, 1 g of hydroquinone monomethyl ether was added to terminate the polymerization reaction. Next, over 0.5 hours, a mixture comprising 5 g of glycidyl methacrylate (hereinafter referred to as "GMA"), 1 g of triethylbenzyl ammonium chloride, and 10 g of DMEA was added dropwise. After the dropwise addition was complete, the mixture was stirred for another 2 hours to carry out the addition reaction. The reaction solution was purified with methanol to remove unreacted impurities, and then further dried under vacuum for 24 hours to obtain a carboxyl-containing acrylic resin with a copolymerization ratio (mass basis) of EA / 2-EHMA / St / GMA / AA = 20 / 40 / 20 / 5 / 15. The acid value of the obtained carboxyl-containing acrylic resin was determined according to JIS K 0070 (1992), and the result was 103 mg KOH / g. The weight-average molecular weight of the obtained carboxyl-containing acrylic resin was 17,000.

[0085] (Example 2: Quinone diazide compound)

[0086] Under a dry nitrogen stream, 21.22 g (0.05 mol) of α,α-bis(4-hydroxyphenyl)-4-(4-hydroxy-α,α-dimethylbenzyl)ethylbenzene (trade name TrisP-PA, manufactured by Honshu Chemical Industry Co., Ltd.) and 33.58 g (0.125 mol) of 5-naphthoquinone diazidesulfonyl chloride were dissolved in 450 g of 1,4-dioxane, and the mixture was kept at room temperature. 15.18 g of triethylamine, mixed with 50 g of 1,4-dioxane, was added dropwise to the mixture to prevent the temperature from exceeding 35°C. The mixture was stirred at 30°C for 2 hours after the addition. The triethylamine salt was filtered, and the filtrate was added to water. The precipitate was then collected by filtration. The precipitate was dried using a vacuum dryer to obtain the quinone diazide compound.

[0087] (Manufacturing Example 3: Photosensitive Conductive Paste)

[0088] Add 3.0g of the carboxyl-containing acrylic resin obtained by Manufacturing Example 1, 0.3g of the photopolymerization initiator N-1919 (manufactured by ADEK Co., Ltd.), 1.2g of the monomer "Light Acrylate (registered trademark)" BP-4EA, 0.5g of the dispersant "BYK (registered trademark)"-LP21116 (manufactured by BYK-Chemie Co., Ltd.), 79.0g of propylene glycol monomethyl ether acetate (hereinafter referred to as "PGMEA"), and 16.0g of silver microparticles with an average thickness of 1nm and a particle size of 40nm with a surface carbon coating (manufactured by Nisshin Engineering Co., Ltd.) to a 100mL clean bottle, and mix with "Awatori Rentaro (registered trademark)" ARE-310 (manufactured by THINKY Co., Ltd.) to obtain 100.0g of photosensitive conductive paste. The viscosity of the obtained photosensitive conductive paste was measured using an E-type viscometer at a temperature of 25°C and a rotation speed of 100 rpm, and the result was 3 mPa·s.

[0089] (Manufacturing Example 4: Positive Photosensitive Resin Composition Containing Resin and Colorant)

[0090] Add 3.34g of phenol Novolac resin WR-104 (manufactured by DIC Co., Ltd.) as an alkali-soluble resin, 0.57g of the quinone diazide compound obtained by Manufacturing Example 2 as a quinone diazide compound, 0.26g of carboxybenzotriazole "VERZONE (registered trademark)" C-BTA (manufactured by Yamato Kasei Co., Ltd.), 0.02g of leveling agent "BYK (registered trademark)"-331 (manufactured by BYK-Chemie Co., Ltd.), and 43.73g of PGMEA to a 100mL clean bottle, and mix using a "Awatori Rentaro (registered trademark)" ARE-310 (manufactured by THINKY Co., Ltd.) to obtain a resin solution of 47.92g. The obtained 47.92 g resin solution, 1.71 g titanium nitride particles (particle diameter 17 nm), and 0.37 g dispersant "BYK"-LP21116 (manufactured by BYK-Chemie) were mixed and then used with a 0.10 mm dispersant filled with 70% by volume. A positive photosensitive resin composition of 50.0g was obtained by mixing zirconium oxide beads (manufactured by Toray Industries, Inc.) in a centrifugal separator and Ultra Apex Mill (manufactured by Kotobuki Industries, Ltd.).

[0091] (Manufacturing Example 5: Aqueous Solution for Electrode Blackening)

[0092] 25.0 g of 36% hydrochloric acid and 0.5 g of tellurium dioxide were mixed. After the tellurium dioxide dissolved, 10.0 g of acetic acid and 64.5 g of water were added and mixed further to obtain 100.0 g of an aqueous solution for electrode blackening. The pH of the obtained aqueous solution for electrode blackening was measured using a pH meter (AP-20 A&D Company, Limited) at 25°C, and the result was 0.

[0093] The evaluations of each embodiment and comparative example were conducted using the following methods.

[0094] (1) Thickness of the opaque wiring electrode pattern

[0095] For a randomly selected portion of the opaque wiring electrode pattern obtained in the opaque wiring electrode pattern forming process of each embodiment and comparative example, the thickness of the opaque wiring electrode pattern was measured using a stylus-type step gauge "SURFCOM (registered trademark)" 1400 (Tokyo Seimitsu Co., Ltd.).

[0096] (2) Transmittance of opaque wiring electrode pattern

[0097] For the pad portion of the opaque wiring electrode pattern obtained in the opaque wiring electrode pattern formation process of each embodiment and comparative example, the transmittance at a wavelength of 365nm was measured using a micro-area spectrophotometer (VSS 400: manufactured by Nippon Denshoku Kogyo Co., Ltd.).

[0098] (3) Line width

[0099] A portion of the opaque wire electrode pattern with a grid shape on the wire substrate obtained in Examples 1-3 and Comparative Examples 1-4 was randomly selected from the straight section and cut using a glass cutter in the direction perpendicular to the major axis (minor axis direction). Additionally, a portion of the opaque wire electrode pattern with a grid shape on the wire substrate obtained in Examples 4-5 was randomly selected from the straight section and cut using a single-edged razor in the direction perpendicular to the major axis (minor axis direction). The cross-section was smoothed using an ion milling apparatus IB-9010CP (manufactured by NEC Corporation), and the cross-section was observed using a field emission analytical scanning electron microscope JSM-7610F (manufactured by NEC Corporation). The linewidth W1 [μm] on the transparent substrate side of the opaque wire electrode pattern, the linewidth W2 [μm] on the upper surface side of the opaque wire electrode pattern, and the linewidth W3 [μm] of the blackened layer were measured.

[0100] (4) Electrical conductivity

[0101] For the wired substrates obtained through the various embodiments and comparative examples, the resistance between the terminals was measured using a resistance measuring instrument. If the resistance value is 10,000Ω or higher, or if the resistance value is too high to be measured by the instrument, it is marked as "NG". It should be noted that the distance between the terminals is set to 17mm, and the width is set to 15mm. Figure 4 The pad portion 6 of the electrode pattern shown for evaluating conductivity and visibility is set to a length of 2 mm and a width of 15 mm.

[0102] (5) From the perspective of the difficulty in recognizing [human]

[0103] For the wired substrates obtained through various embodiments and comparative examples, a black sheet SuperBlackIR (manufactured by Systems Engineering Inc.) was placed on the transparent substrate surface in a manner where the opaque wire pattern formation surface was visible. Light was then projected vertically onto the wired substrate using a projector. Ten people each visually viewed the wired substrate vertically from a distance of 30 cm, and the degree of visual resistance was evaluated based on the number of people who could visually identify the grid-shaped wires.

[0104] (6) Difficulty in seeing from the angle of inclination [human]

[0105] For the wired substrates obtained through the various embodiments and comparative examples, a black sheet SuperBlackIR (manufactured by Systems Engineering Inc.) was placed on the transparent substrate surface in a manner where the transparent wiring pattern formation surface is visible. Light was then projected vertically onto the wired substrate using a projector. Ten people viewed the wired substrate from a distance of 30 cm at a 45-degree angle, and the visibility resistance was evaluated based on the number of people who could visually identify the grid-shaped wiring.

[0106] (7) Difficulty in seeing the substrate surface [human]

[0107] For the wired substrates obtained through the various embodiments and comparative examples, a black sheet SuperBlackIR (manufactured by Systems Engineering Inc.) was placed on the opaque wire pattern forming surface in a manner visible from the substrate side, and a projector was used to project light vertically onto the wired substrate. Ten people viewed the wired substrate from a distance of 30 cm at a 45-degree angle, and the visibility resistance was evaluated based on the number of people who could visually identify the grid-shaped wires.

[0108] (8) Light transmittance

[0109] For the areas with grid-shaped patterns on the wiring substrates obtained through the various embodiments and comparative examples, the total light transmittance was measured using a spectrophotometer (HSP-150Vis manufactured by Murakami Color Technology Research Institute Co., Ltd.).

[0110] (Example 1)

[0111] <Opaque wiring electrode patterning process>

[0112] On one side of alkali-free glass "AN Wizus (registered trademark)" (manufactured by AGC Corporation, transmittance at 365nm: 91%, transmittance at 550nm: 92%, thickness: 0.5mm), the photosensitive conductive paste obtained in Manufacturing Example 3 was spin-coated to a thickness of 1μm after drying, and then dried at 90°C for 8 minutes. Figure 4 The exposure mask shown, including pad 6 and a grid-shaped pattern, was applied using an exposure apparatus (PEM-6M; manufactured by Union Optical Co., Ltd.) with an exposure gap of 50 μm and an exposure dose of 150 mJ / cm². 2 Exposure is performed (based on a wavelength of 365nm). Here, the grid-shaped pattern is... Figure 5 The pattern shown is a negative pattern with a grid spacing of 150 μm (7), a grid angle of 90° (8), and an opening 10 with an opening width of 4 μm and a light-shielding portion 9. Next, a 0.1% (w / w) tetramethylammonium hydroxide aqueous solution was used as the developer, and development was performed for twice the time required for the exposure portion to dissolve. It was then rinsed with ultrapure water for 30 seconds, and finally cured in a box oven at 230°C for 60 minutes to form an opaque wiring electrode pattern. The thickness of the opaque wiring electrode pattern, measured by the aforementioned method, was 0.5 μm. Furthermore, the transmittance of the opaque wiring electrode pattern at a wavelength of 365 nm, measured by the aforementioned method, was 0%.

[0113] <Black photosensitive layer formation process>

[0114] On the opaque wiring electrode pattern formed in the <Opaque Wiring Electrode Pattern Forming Process>, a positive photosensitive resin composition containing resin and colorant obtained by Manufacturing Example 4 is spin-coated to a thickness of 3 μm after drying, and dried at 100°C for 5 minutes to form a black photosensitive layer.

[0115] <Blackening layer formation process>

[0116] For the black photosensitive layer formed in the <Black Photosensitive Layer Formation Process>, using the opaque wiring electrode pattern as a mask, an exposure apparatus (PEM-6M) is used to expose the black photosensitive layer from the opposite side of the opaque wiring electrode formation surface at an exposure amount (converted to wavelength 365nm) of 3,000 mJ / cm². 2Exposure was performed under the following conditions: a 2.38% by mass tetramethylammonium hydroxide aqueous solution was used as the developer until the transparent substrate of the exposed area was exposed, forming a blackening layer on the upper and sides of the opaque wiring electrode pattern. Further, the substrate was heated in a box oven at 220°C for 60 minutes to obtain a wiring substrate.

[0117] (Example 2)

[0118] In the <Opaque Wiring Electrode Pattern Forming Process>, the photosensitive conductive paste is applied to a thickness of 2.5 μm after drying. Otherwise, the same procedure as in (Example 1) is followed to obtain the wiring substrate.

[0119] (Example 3)

[0120] In the <Black Photosensitive Layer Formation Process>, the exposure is set to 5,000 mJ / cm. 2 The development time is set to 1.5 times the time until the transparent substrate of the exposed part is exposed. Otherwise, the same operation as in (Example 1) is performed to obtain a substrate with wiring.

[0121] (Example 4)

[0122] <Opaque wiring electrode patterning process>

[0123] On one side of a PET film, "Lumirror" T60 (manufactured by Toray Industries, Inc., thickness: 75 μm, transmittance at 365 nm: 77%, transmittance at 550 nm: 89%), a 0.2 μm thick chromium film was formed by sputtering, followed by a 2.0 μm thick copper film formed across the entire surface by vapor deposition. Next, LC-140 resist (manufactured by Rohm and Haas Electronic Materials Co., Ltd.) was spin-coated onto the copper film and dried at 100°C for 5 minutes. Then, [the process was repeated]. Figure 4 The pad portion 6 shown and the exposure mask with a grid pattern were exposed using an exposure apparatus (PEM-6M; manufactured by Union Optical Co., Ltd.) at an exposure dose of 45 mJ / cm². 2 Exposure is performed (based on a wavelength of 365nm). Here, the grid-shaped pattern is... Figure 6The pattern shown has a grid spacing of 150 μm (7), a grid angle of 90° (8), and includes an opening (10) and a light-shielding portion (9) with a light-shielding width of 16 μm. Next, a 2.38% (w / w) tetramethylammonium hydroxide aqueous solution was used as the developer for 30 seconds of immersion development, followed by rinsing with ultrapure water for 30 seconds. Then, copper and chromium films were etched using a ferric chloride aqueous solution at a linewidth of 4.5 μm, followed by rinsing with ultrapure water for 30 seconds. Next, a resist stripping solution, JELK-101 (manufactured by Kanto Chemical Co., Ltd.), was used for 4 minutes of immersion development, followed by rinsing with ultrapure water for 30 seconds to form an opaque wiring electrode pattern. The thickness of the opaque wiring electrode pattern, measured by the aforementioned method, was 2.5 μm. Furthermore, the transmittance of the opaque wiring electrode pattern at a wavelength of 365 nm, measured by the aforementioned method, was 0%.

[0124] <Black photosensitive layer formation process>

[0125] On the opaque wiring electrode pattern formed in the <Opaque Wiring Electrode Pattern Forming Process>, a black photosensitive layer is formed in the same manner as in (Example 1).

[0126] <Blackening layer formation process>

[0127] The heating temperature of the box oven after the blackening layer is formed is set to 140°C. Otherwise, the same operation as in (Example 1) is performed to form a black photosensitive layer and obtain a substrate with wiring.

[0128] (Example 5)

[0129] The chromium film formed as the base layer in the <Opaque Wiring Electrode Pattern Forming Process> is replaced with a copper nitride film (black layer). Otherwise, the same procedure as in (Example 4) is followed to obtain a wiring substrate.

[0130] (Comparative Example 1)

[0131] The exposure gap in the <Opaque Wiring Electrode Pattern Forming Process> was changed to 0 μm, and the same procedure as in (Example 1) was followed to obtain a wiring substrate.

[0132] (Comparative Example 2)

[0133] The exposure gap in the <Opaque Wiring Electrode Pattern Forming Process> was changed to 0 μm, and the same procedure as in (Example 2) was followed to obtain a wiring substrate.

[0134] (Comparative Example 3)

[0135] <Opaque wiring electrode patterning process>

[0136] The same procedure as in (Example 1) is followed to form an opaque wiring electrode pattern.

[0137] <Blackening layer formation process>

[0138] The opaque wiring electrode pattern formed in the <Opaque Wiring Electrode Pattern Forming Process> is immersed in the electrode blackening aqueous solution obtained by Manufacturing Example 5 for 30 seconds, then washed with water and dried to form a blackening layer on the upper and side parts of the opaque wiring electrode pattern, thus obtaining a wiring substrate.

[0139] (Comparative Example 4)

[0140] <Opaque wiring electrode patterning process>

[0141] The same procedure as in (Comparative Example 1) was followed to form an opaque wiring electrode pattern.

[0142] <Black photosensitive layer formation process>

[0143] The same procedure as in (Comparative Example 1) was followed to form a black photosensitive layer.

[0144] <Blackening layer formation process>

[0145] Regarding the black photosensitive layer formed in the <black photosensitive layer formation process>, Figure 4 The pad portion 6 shown and the exposure mask with a grid-shaped pattern are arranged such that the opaque wiring electrode pattern formed in the <Opaque Wiring Electrode Pattern Forming Process> overlaps with the mask's light-shielding portion, and an exposure apparatus (PEM-6M; manufactured by Union Optical Co., Ltd.) is used, with an exposure amount of 3,000 mJ / cm² across the aforementioned exposure mask. 2 Exposure is performed (based on a wavelength of 365nm). Here, the grid-shaped pattern is... Figure 6 The pattern shown has a grid spacing of 150 μm, a grid angle of 90°, and includes an opening 10 and a light-shielding portion 9 with a light-shielding width of 9 μm. Next, a 2.38% by mass tetramethylammonium hydroxide aqueous solution is used as the developer, and development is performed until the transparent substrate of the exposed portion is exposed, forming a blackening layer on the upper and sides of the opaque wiring electrode pattern. Further, the pattern is heated in a box oven at 220°C for 60 minutes to obtain a wiring substrate.

[0146] The evaluation results of each embodiment and comparative example are shown in Table 1.

[0147] [Table 1]

[0148]

[0149] Explanation of reference numerals in the attached figures

[0150] 1: Transparent substrate

[0151] 2: Opaque wiring electrode pattern

[0152] 3: Blackening layer

[0153] 4: Substrate with wiring

[0154] 5: Base layer (black layer)

[0155] 6: Solder pad area

[0156] 7: Grid spacing

[0157] 8: Grid Angle

[0158] 9: Shading part

[0159] 10: Opening

[0160] W1: Line width on the transparent substrate side of the opaque wiring electrode pattern

[0161] W2: Line width on the upper surface side of the opaque wiring electrode pattern

[0162] W3: Line width of the blackening layer

Claims

1. A wiring substrate, wherein the wiring substrate has an opaque wiring electrode pattern on a transparent substrate, characterized in that, The upper and side portions of the opaque wiring electrode pattern have a blackening layer containing resin and colorant. The line width W1 on the transparent substrate side of the opaque wiring electrode pattern, the line width W2 on the upper surface side of the opaque wiring electrode pattern, and the line width W3 of the blackening layer satisfy the following relationship (1), where the units of line width W1, line width W2, and line width W3 are μm. W1≥W3>W2 (1).

2. The substrate with wiring as described in claim 1, wherein, The opaque wiring electrode pattern has a black layer on the transparent substrate side.

3. The substrate with wiring as described in claim 1 or 2, wherein, The thickness T1 of the opaque wiring electrode pattern is 1.0 μm to 10.0 μm.

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