Base material with wiring and method for producing same
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Filing Date
- 2023-12-22
- Publication Date
- 2026-07-01
Abstract
Description
Wired substrate and method for producing same
[0001] The present invention relates to a wired substrate having an opaque wiring electrode pattern with a blackened layer on the top and sides on at least one surface of a transparent substrate, and a method for producing the same.
[0002] Touch panels, which have become widely used as input devices in recent years, consist of a display unit such as a liquid crystal panel and a touch sensor that detects information input at a specific position. While transparent wiring electrodes have typically been used as the wiring electrodes for touch sensors to reduce their visibility, opaque wiring electrodes made of metallic materials have become more common in recent years due to increased sensitivity and larger screen sizes. Opaque wiring electrodes made of metallic materials have a problem of being visible due to their metallic luster. To address this problem, a metal blackening treatment method has been proposed for forming a blackened layer on an electromagnetic wave shielding filter for a display, which is composed of at least a transparent substrate, a copper mesh layer, and a blackened layer, to improve the visibility of the display screen. The metal blackening treatment method includes a step of contacting a laminate comprising at least a transparent substrate and a copper mesh layer with a metal blackening treatment solution, which is a hydrochloric acid solution containing dissolved tellurium, to form a blackened layer on the surface of the copper mesh layer (see, for example, Patent Document 1). However, this metal blackening treatment method suffers from a problem of reduced conductivity of the opaque wiring electrodes due to oxidation of the metal. In response to this, a method for manufacturing a substrate with wiring electrodes that has excellent conductivity and makes the opaque wiring electrodes and wiring electrodes less visible has been proposed, which includes the steps of forming an opaque wiring electrode pattern on at least one side of a transparent substrate, applying a positive-type photosensitive light-shielding composition to one side of the transparent substrate, and exposing and developing the positive-type photosensitive composition using the opaque wiring electrode pattern as a mask to form a light-shielding layer on top of the opaque wiring electrode pattern (see, for example, Patent Document 2). Also proposed as an electrode film with excellent mesh pattern invisibility and image visibility is an electrode film that includes a transparent substrate, a metal mesh electrode provided on a first main surface of the transparent substrate, and a black photoresist layer provided on the upper and both side surfaces of the fine wires that make up the mesh of the metal mesh electrode (see, for example, Patent Document 3).
[0003] Patent Document 1: JP 2008-147356 A, International Publication No. 2018 / 168325, International Publication No. 2019 / 44339
[0004] The method disclosed in Patent Document 2 can suppress the visibility of the opaque wiring electrode pattern due to its metallic luster. When the substrate with wiring electrodes is viewed from the front, the opaque wiring electrode pattern is hardly visible. However, because the electrodes are exposed on the sides of the opaque wiring electrode pattern, the electrode luster on the sides of the opaque wiring electrode pattern is easily visible when the substrate with wiring electrodes is viewed from an oblique direction. This problem becomes more pronounced as the opaque wiring electrode pattern is made thicker to improve conductivity, making it difficult to achieve both the invisibility of the opaque wiring electrode pattern and improved conductivity. Furthermore, the electrode film disclosed in Patent Document 3 tends to have reduced light transmittance because the area occupied by the opaque region (metal electrode mesh and blackened layer) in the area of the transparent substrate is increased by forming a blackened layer on the side. In recent years, improved light transmittance has also been required for wired substrates in order to improve the brightness of touch panel displays.
[0005] Therefore, an object of the present invention is to provide a wired substrate having an opaque wiring electrode pattern that is difficult to see even from an oblique direction and that has excellent electrical conductivity and light transmittance.
[0006] In order to solve the above problems, the present invention mainly has the following configurations. <1> A wired substrate having an opaque wiring electrode pattern on a transparent substrate, wherein blackened layers containing a resin and a colorant are formed on the top and sides of the opaque wiring electrode pattern, and the line width W1 [μm] of the opaque wiring electrode pattern on the transparent substrate side, the line width W2 [μm] of the opaque wiring electrode pattern on the top surface side, and the line width W3 [μm] of the blackened layer satisfy the relationship of the following formula (1): W1 ≧ W3 > W2 (1) <2> The wired substrate according to <1>, wherein the opaque wiring electrode pattern has a blackened layer on the transparent substrate side. <3> The wired substrate according to claim <1> or <2>, wherein the thickness T1 [μm] of the opaque wiring electrode pattern is 1.0 to 10.0 μm. <4> A method for producing a wired substrate according to any one of <1> to <3>, comprising the steps of: forming, on a transparent substrate, an opaque wiring electrode pattern having a line width W1 [μm] on a transparent substrate surface side and a line width W2 [μm] on an upper surface side; forming a black photosensitive layer by applying a positive photosensitive resin composition containing a resin and a colorant to the surface of the transparent substrate on which the opaque wiring electrode pattern is formed; and exposing and developing the black photosensitive layer using the opaque wiring electrode pattern as a mask to form blackened layers having a line width W3 [μm] on the top and side of the opaque wiring electrode pattern.
[0007] The wired substrate of the present invention has an opaque wiring electrode pattern that is difficult to see even from an oblique direction, and is excellent in electrical conductivity and light transmittance.
[0008] Fig. 1 is a schematic diagram showing an example of the configuration of a wired substrate of the present invention. Fig. 2 is a schematic diagram showing another example of the configuration of a wired substrate of the present invention. Fig. 3 is a schematic diagram showing an example of an opaque wiring electrode pattern and a blackening layer in the present invention. Fig. 4 is a schematic diagram showing an electrode pattern for evaluating conductivity, visibility, and light transmittance used in Examples and Comparative Examples. Fig. 5 is a schematic diagram of a mesh pattern of a negative-type mask used in Examples and Comparative Examples. Fig. 6 is a schematic diagram of a mesh pattern of a positive-type mask used in Examples and Comparative Examples.
[0009] The wired substrate of the present invention has, on a transparent substrate, an opaque wiring electrode pattern having blackened layers on the top and sides. The blackened layers contain a resin and a colorant and have the effect of suppressing light reflection and light scattering of the opaque wiring electrode pattern, making it less visible. By having blackened layers on the top and sides of the opaque wiring electrode pattern, it is possible to make it less visible not only when the wired substrate is viewed from the front, but also when the wired substrate is viewed from an oblique direction.
[0010] Furthermore, a transparent protective layer may be provided thereon. By providing the transparent protective layer, it is possible to protect the opaque wiring electrode and the surface of the blackened layer and to suppress scratches, etc. Here, in the present invention, "transparent" means that the light transmittance at a wavelength of 550 nm is 50% or more, and "opaque" means that the light transmittance at a wavelength of 550 nm is less than 50%. The light transmittance at a wavelength of 550 nm can be measured using an ultraviolet-visible spectrophotometer (U-3310: manufactured by Hitachi High-Technologies Corporation). In addition, in the present invention, the transparent substrate side of the wired substrate is referred to as "bottom," and the side opposite the transparent substrate with respect to the opaque wiring electrode is referred to as "top."
[0011] Fig. 1 shows a schematic diagram of one example of the configuration of a wired substrate of the present invention. The wired substrate 4 has an opaque wiring electrode pattern 2 on a transparent substrate 1, and has blackened layers 3 on the top and sides of the opaque wiring electrode pattern 2. Fig. 2 shows another example of the configuration of a wired substrate of the present invention. The wired substrate 4 has an opaque wiring electrode pattern 2 on a transparent substrate 1, and has blackened layers 3 on the top and sides of the opaque wiring electrode pattern 2. The opaque wiring electrode pattern 2 has an underlayer (black layer) 5 on the transparent substrate 1 side.
[0012] In the present invention, the line width W1 [μm] of the opaque wiring electrode pattern on the transparent substrate surface side, the line width W2 [μm] of the opaque wiring electrode pattern on the upper surface side, and the line width W3 [μm] of the blackening layer satisfy the relationship of the following formula (1): W1≧W3>W2 (1).
[0013] That is, the opaque wiring electrode pattern has a so-called tapered cross section in which the line width W1 on the transparent substrate side (bottom surface) is larger than the line width W2 on the top surface side (top surface). The line width W3 of the blackening layer refers to the maximum line width of the blackening layer and is equal to or smaller than the line width W1 on the transparent substrate side (bottom surface) of the opaque wiring electrode pattern. That is, the blackening layer does not form a tapered cross section that follows the opaque wiring electrode pattern. Furthermore, since the blackening layer is present on the side of the opaque wiring electrode pattern, its line width W3 is larger than W2. Here, if the opaque wiring electrode pattern is linear, the line width 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. The line width of the blackening layer refers to the overall width from end to end of the blackening layer, even if the opaque wiring electrode pattern is partially enclosed within the blackening layer. As will be described later, when the pattern of the opaque wiring electrode has a base layer on a part thereof (on the transparent substrate side), the line width W1 [μm] of the opaque wiring electrode pattern on the transparent substrate side refers to the line width of the base layer in contact with the transparent substrate. Furthermore, when the opaque wiring electrode pattern has a dome shape, the apex of the dome shape is set as the line width W2 on the upper surface side, which is 0 μm.
[0014] FIG. 3 shows a schematic diagram 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 the transparent substrate 1 has a tapered shape with a line width W1 on the transparent substrate surface side and a line width W2 on the upper surface side. The upper and side surfaces of the opaque wiring electrode pattern 2 have a blackening layer 3 with a line width W3. In FIG. 3 , the periphery of the blackening layer 3 forms three sides of a rectangle, but the blackening layer 3 may have a tapered shape as long as the above formula (1) is satisfied. As described above, by providing a blackening layer on the top and side of the opaque wiring electrode pattern, the opaque wiring electrode pattern can be made less visible not only when the wired substrate is viewed from the front but also when the wired substrate is viewed from an oblique direction. The inventors' studies have revealed that, as disclosed in Patent Document 3, when the blackening layer covers the entire top and side of the opaque wiring electrode pattern, i.e., when the line width W3 of the blackening layer is greater than the line widths W1 and W2 of the opaque wiring electrode pattern, the light transmittance of the wired substrate is reduced. In the present invention, the light transmittance of the wired substrate can be improved by setting the line width W3 of the blackening layer to be equal to or less than the line width W1 of the opaque wiring electrode pattern on the transparent substrate surface side. To form a blackening layer that satisfies this condition, the opaque wiring electrode pattern preferably has a tapered cross-section. By making the line width W1 on the transparent substrate surface side larger than the line width W2 on the upper surface side, the cross-sectional area of the opaque wiring electrode pattern can be increased, thereby improving conductivity, even if a blackening layer thick enough to make it less visible on the sides is formed. Here, each line width can be measured by magnifying and observing a cross-section of the opaque wiring electrode pattern and the blackening layer in the minor axis direction using a scanning electron microscope (SEM).
[0015] From the viewpoint of sufficiently suppressing reflection on the sides of the opaque wiring electrode pattern, the difference between the line width W1 of the opaque wiring electrode pattern and the line width W3 of the blackened layer is preferably 0.3 μm or less, more preferably 0.1 μm or less, and even more preferably W1=W3.
[0016] The difference between the line widths W1 and W2 of the opaque wiring electrode pattern is preferably 0.1 μm or more from the viewpoint of forming a blackened layer of sufficient width on the side of the opaque wiring electrode pattern and making the opaque wiring electrode pattern less visible even from an oblique direction, while the difference between the line widths W1 and W2 of the opaque wiring electrode pattern is preferably 2.0 μm or less, more preferably 1.5 μm or less, from the viewpoint of further improving conductivity.
[0017] The opaque wiring electrode pattern and the blackened layer that satisfy the above formula (1) can be easily formed, for example, by the method for producing a wired substrate described below.
[0018] (Transparent Substrate) The transparent substrate is preferably transparent to the exposure light used in the blackening layer formation step of the method for producing a wired substrate, which will be described later. Specifically, the light transmittance at a wavelength of 365 nm is preferably 50% or more, and more preferably 70% or more. By ensuring that the light transmittance at a wavelength of 365 nm is 50% or more, the positive photosensitive resin composition can be efficiently exposed in the blackening layer formation step, which will be described later. The light transmittance at a wavelength of 365 nm of the transparent substrate can be measured using an ultraviolet-visible spectrophotometer (U-3310: manufactured by Hitachi High-Technologies Corporation).
[0019] The transparent substrate may or may not be flexible. Examples of non-flexible transparent substrates include quartz glass substrates, soda glass substrates, alkali-free glass substrates, chemically strengthened glass substrates, Pyrex (registered trademark) glass substrates, synthetic quartz plates, 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"), resin films such as cycloolefin polymer films, polyimide films, and aramid films, and optical resin plates. A plurality of these may be used in layers, for example, by bonding multiple transparent substrates together with an adhesive layer. In addition, the surface of these transparent substrates may have an inorganic film, an insulating layer, or the like. Examples of inorganic films include films of silicon dioxide, niobium pentoxide, and the like. By having an inorganic film on the transparent substrate, the adhesion between the transparent substrate and the opaque wiring electrode pattern can be improved.
[0020] The thickness of the transparent substrate is appropriately selected depending on the material within the range that can stably support the opaque wiring electrode pattern and has the above-mentioned transparency. For example, from the viewpoint of more stably supporting the opaque wiring electrode pattern, the thickness is preferably 0.3 mm or more for a non-flexible transparent substrate, and preferably 25 μm or more for a flexible transparent substrate. On the other hand, from the viewpoint of further improving the transparency of the exposure light, the thickness of the transparent substrate is preferably 1.5 mm or less for a non-flexible transparent substrate, and preferably 300 μm or less for a flexible transparent substrate.
[0021] (Opaque wiring electrode pattern) The opaque wiring electrode pattern preferably has a light transmittance of 25% or less at a wavelength of 550 nm. It also preferably has light-shielding properties against the exposure light used in the blackening layer formation step of the method for producing a wired substrate, which will be described later. Specifically, the light transmittance at a wavelength of 365 nm is preferably 15% or less. By setting the light transmittance at a wavelength of 365 nm to 15% or less, the mask function can be improved in the blackening layer formation step, which will be described later, and the desired blackening layer can be formed with greater processability. The light transmittance of the opaque wiring electrode pattern can be measured for an opaque wiring electrode pattern of 0.1 mm square or more using a microsurface spectrophotometer (VSS 400: manufactured by Nippon Denshoku Industries Co., Ltd.).
[0022] Examples of materials constituting the opaque wiring electrode pattern include metals such as silver, gold, copper, platinum, lead, tin, nickel, aluminum, tungsten, molybdenum, chromium, titanium, and indium, and conductive materials such as alloys of these. Two or more of these may be used. Among these, silver, copper, and the like are preferred from the viewpoint of conductivity.
[0023] The opaque wiring electrode pattern may contain an organic component in addition to the aforementioned conductive substance. The opaque wiring electrode pattern may be formed, for example, from a cured product of a photosensitive conductive composition containing 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 photodecomposition product. The photosensitive conductive composition may contain additives such as a heat curing agent and a leveling agent, as necessary.
[0024] Examples of the pattern shape of the opaque wiring electrode pattern include a mesh shape and a stripe shape. Examples of the mesh shape include a lattice shape with unit shapes such as triangles, squares, polygons, and circles, or a lattice shape consisting of a combination of these unit shapes. Among these, the mesh shape is preferred from the viewpoint of achieving uniform conductivity of the pattern. It is more preferred that the opaque wiring electrode pattern is a metal mesh made of the above-mentioned metal and having a mesh-like pattern.
[0025] The thickness T1 [μm] of the opaque wiring electrode pattern is preferably 1.0 or more, and more preferably 1.5 or more, from the viewpoint of further improving conductivity. As described above, when the wiring substrate is viewed from an oblique direction, the tendency for the electrode gloss on the side of the opaque wiring electrode pattern to be easily visible becomes more pronounced as the thickness of the opaque wiring electrode pattern increases. In the present invention, since the opaque wiring electrode pattern has a blackened layer on the top and sides thereof, the thicker the opaque wiring electrode pattern, the more pronounced 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. T1 can be measured using a stylus-type step profiler.
[0026] From the viewpoint of further improving conductivity, the line widths W1 and W2 of the opaque wiring electrode pattern are both 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 line width W1 of the opaque wiring electrode pattern is preferably 10 μm or less, more preferably 8 μm or less.
[0027] From the viewpoint of making the opaque wiring electrode pattern less visible and improving light transmittance, the proportion of the area where the opaque wiring electrode pattern is formed in the entire transparent substrate is preferably 20 area % or less, more preferably 15 area % or less. Two or more layers of opaque wiring electrode patterns may be laminated with transparent protective layers interposed therebetween, which reduces the proportion of the area where the opaque wiring electrode pattern is formed while maintaining conductivity, making it more difficult to see.
[0028] The opaque wiring electrode pattern may have an underlayer on the transparent substrate surface. Examples of the underlayer include a black layer and an adhesive layer. When the opaque wiring electrode pattern has a black layer on the transparent substrate surface, the transparent substrate side of the opaque wiring electrode pattern can be blackened, making the opaque wiring electrode pattern less visible even when the wired substrate is viewed from the back surface (transparent substrate side). Furthermore, when the opaque wiring electrode pattern has an adhesive layer on the transparent substrate surface, the adhesion between the transparent substrate and the opaque wiring electrode pattern can be improved. Two or more of these may be laminated.
[0029] The underlayer preferably has a light-blocking property against the exposure light used in the blackening layer forming step of the method for producing a wired substrate, which will be described later. Examples of underlayers having a light-blocking property include a layer made of a material that has a high reflectivity and absorption of the exposure light, and a metal layer having a large refractive index difference from the transparent substrate. Even if a metal layer having a large refractive index difference from the transparent substrate itself transmits the exposure light, it can attenuate the exposure light due to interfacial reflection with the transparent substrate, thereby increasing the light-blocking property.
[0030] Examples of materials constituting the black layer include copper oxide, copper nitride, and nickel. Examples of materials constituting the adhesion layer include chromium, titanium, and alloys thereof. From the viewpoint of improving the adhesion between the opaque wiring electrode pattern and the transparent substrate and suppressing peeling of the opaque wiring electrode pattern, it is preferable to have an adhesion layer. Also, from the viewpoint of making the opaque wiring electrode pattern less visible even when the wired substrate is viewed from the backside, it is preferable to have a black layer.
[0031] (Blackening Layer) The blackening layer contains a resin and a colorant. By containing a colorant, the blackening layer can suppress reflection caused by the metallic luster of the opaque wiring electrode pattern, making the opaque wiring electrode pattern less visible. Furthermore, by containing a resin, the blackening layer can suppress surface reflection of the colorant, making the blackening layer less visible.
[0032] Examples of colorants include pigments such as inorganic pigments and organic pigments, dyes, etc. Two or more of these may be used. Among these, pigments are preferred due to their excellent weather resistance. More specifically, examples include those exemplified as colorants in WO 2018 / 168325, organic pigments such as soluble azo pigments, insoluble azo pigments, metal complex azo pigments, phthalocyanine pigments, and condensed polycyclic pigments, and inorganic pigments such as pine soot, ultramarine, iron oxides such as hematite, goethite, and magnetite, titanium, chromium, lead, and metal composites thereof. Among these, carbon black is preferred from the viewpoint of availability, and titanium nitride and zirconium nitride are preferred from the viewpoint of light transmittance of exposure light.
[0033] Examples of resins include phenolic resins, polyimide resins, acrylic resins, cardo resins, epoxy resins, melamine resins, urethane resins, silicone resins, fluorine-based resins, polyamide resins, polyvinyl ether resins, vinyl acetate / vinyl chloride copolymers, modified polyolefin resins, natural rubber, synthetic rubber, etc. Two or more of these may be used.
[0034] In the blackening layer formation step of the method for producing a wired substrate described below, when a pattern is formed by photolithography, an alkali-soluble resin is preferred as the resin. Here, examples of alkali-soluble resins include resins having hydroxyl groups and / or carboxyl groups. Among these, resins having phenolic hydroxyl groups are preferred. Examples of resins having phenolic hydroxyl groups include novolak resins such as phenol novolak resins and cresol novolak resins, polymers of monomers having phenolic hydroxyl groups, and copolymers of monomers having phenolic hydroxyl groups with styrene, acrylonitrile, acrylic monomers, etc. Two or more of these may be contained.
[0035] (Transparent protective layer) The transparent protective layer preferably has insulating properties in order to prevent short circuits between opaque wiring electrode patterns. Examples of the insulating transparent protective layer include those exemplified as insulating layers in WO 2018 / 168325.
[0036] (Method for manufacturing wired substrate) Next, a method for manufacturing a wired substrate of the present invention will be described. The method for manufacturing a wired substrate of the present invention includes a step of forming an opaque wiring electrode pattern on a transparent substrate, the pattern having a line width W1 [μm] on the transparent substrate surface side and a line width W2 [μm] on the upper surface side (hereinafter sometimes abbreviated as the "opaque wiring electrode pattern forming step"), a step of forming a black photosensitive layer on the surface of the transparent substrate on which the opaque wiring electrode pattern is formed (hereinafter sometimes abbreviated as the "black photosensitive layer forming step"), and a step of exposing the black photosensitive layer using the opaque wiring electrode pattern as a mask and developing it to form a blackened layer on the top and sides of the opaque wiring electrode pattern (hereinafter sometimes abbreviated as the "blackened layer forming step"). In the opaque wiring electrode pattern forming step, a tapered opaque wiring electrode pattern is formed in which the line width W1 [μm] on the transparent substrate surface side and the line width W2 [μm] on the upper surface side satisfy the relationship of the above-mentioned formula (1), and in the blackening layer forming step, when the black photosensitive layer is exposed using the tapered opaque wiring electrode pattern as a mask, the exposure light is blocked within the range of the line width W1 on the transparent substrate surface side of the tapered opaque wiring electrode pattern, and therefore a blackening layer having the shape shown in FIG. 3 and having a line width W3 [μm] that satisfies the above-mentioned formula (1) can be easily formed, which is preferable.
[0037] (Opaque wiring electrode pattern forming step) First, in the opaque wiring electrode pattern forming step, an opaque wiring electrode pattern is formed on at least one surface of a transparent substrate. Opaque wiring electrode patterns may be formed on both surfaces of the transparent substrate. In this case, the opaque wiring electrode patterns formed on both surfaces sandwiching the transparent substrate are both positioned "above" the transparent substrate, which is positioned "below" in the present invention.
[0038] Examples of methods for forming an opaque wiring electrode pattern include a method of forming a pattern by photolithography using the above-mentioned photosensitive conductive composition, a method of forming a pattern by screen printing, gravure printing, inkjet printing, or the like using a conductive composition (conductive paste), a method of forming a film of metal, metal composite, metal and metal compound composite, metal alloy, or the like, and then forming a pattern by photolithography using a resist, and a method of transferring an opaque wiring electrode pattern formed by photolithography using the above-mentioned photosensitive conductive composition on a release film to a transparent substrate. Here, the release film refers to a film having a release layer on its surface, and examples of release agents for forming the release layer include 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 opaque wiring electrode patterns are formed via a transparent protective layer, each opaque wiring electrode pattern may be formed by the same method, or different methods may be combined.
[0039] When forming an opaque wiring electrode pattern having an underlayer on the transparent substrate side, for example, a method may be used in which a film of a material that constitutes the underlayer is formed on the transparent substrate, and then a film of a metal, a metal composite, a composite of a metal and a metal compound, a metal alloy, or the like is formed, and a pattern is formed all at once or sequentially by a photolithography method using a resist.
[0040] When a pattern formed from a photosensitive conductive composition exhibits conductivity by heat curing, it is preferable to heat cure it at 140 to 500°C.
[0041] As a method for making the line width W1 [μm] on the transparent substrate surface side of the opaque wiring electrode pattern larger than the line width W2 [μm] on the upper surface side, for example, when forming a pattern by photolithography using a photosensitive conductive composition, a method of widening the exposure gap between the photomask and the photosensitive conductive composition during exposure can be mentioned. 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 linearity of the pattern after development, the exposure gap is preferably 100 μm or less, more preferably 70 μm or less. Furthermore, when a pattern is formed on a release film by photolithography using a photosensitive conductive composition and transferred onto a transparent substrate, the pattern formed on the release film can be made in an inverted tapered shape and transferred onto the transparent substrate, thereby making the line width W1 [μm] on the transparent substrate surface side larger than the line width W2 [μm] on the upper surface side. By using a negative photosensitive conductive composition, a pattern with an inverted tapered shape can be easily formed. Furthermore, when a film of a metal, a metal composite, a composite of a metal and a metal compound, a metal alloy, or the like is formed and patterned by photolithography using a resist, etching proceeds not only in the vertical direction but also in the horizontal direction relative to the metal film, so that the line width W1 [μm] on the transparent substrate surface side tends to be larger than the line width W2 [μm] on the upper surface side. Furthermore, when an opaque wiring electrode pattern having an underlayer is formed, by selecting a material that takes a longer time to etch than the metal film as the material for the underlayer, the line width W1 [μm] on the transparent substrate surface side of the underlayer can be patterned to be larger than the line width W2 [μm] on the upper surface side of the opaque wiring electrode pattern.
[0042] (Black Photosensitive Layer Forming Step) Next, in the black photosensitive layer forming step, a black photosensitive layer is formed on the surface of the transparent substrate on which the opaque wiring electrode pattern is formed. Here, the black photosensitive layer corresponds to the precursor of the blackened layer obtained in the blackened layer forming step. Methods for forming a black photosensitive layer on the surface of the transparent substrate on which the opaque wiring electrode pattern is formed include, for example, a method of applying 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 to the transparent substrate. Among these, a coating method is preferred from the viewpoint of forming a blackened layer of sufficient width on the electrode side surface. Examples of resins and colorants include those described above. Methods for applying a positive photosensitive resin composition containing a resin and a colorant include, for example, spin coating using a spinner, spray coating, roll coating, screen printing, and coating using a coater such as a slit coater, blade coater, die coater, calendar coater, meniscus coater, or bar coater.
[0043] The positive photosensitive resin composition refers to a composition having positive photosensitivity in which the irradiated portion dissolves in a developer, and preferably contains a photosensitizer (dissolution inhibitor) and an alkali-soluble resin. Furthermore, the composition may contain a plasticizer, a leveling agent, a surfactant, a rust inhibitor, a crosslinking agent, a silane coupling agent, an antifoaming agent, a stabilizer, etc., within a range that does not impair the desired properties. Furthermore, the composition preferably contains a solvent, which allows the viscosity of the positive photosensitive resin composition to be adjusted to a desired range.
[0044] Examples of the alkali-soluble resin and the photosensitizer (dissolution inhibitor) include those exemplified as alkali-soluble resins and photosensitizers (dissolution inhibitors) contained in the positive-type photosensitive composition in WO 2018 / 168325. The content of the alkali-soluble resin in the black photosensitive layer is preferably 45 to 65% by mass. The content of the photosensitizer (dissolution inhibitor) in the black photosensitive layer is preferably 5 to 25% by mass.
[0045] (Blackening Layer Forming Step) Next, in the blackening layer forming step, the black photosensitive layer is exposed and developed using the opaque wiring electrode pattern as a mask, thereby forming a blackening layer on the top and sides of the opaque wiring electrode pattern. As described above, by exposing using as a mask the tapered opaque wiring electrode pattern whose line width W1 [μm] on the transparent substrate surface side is larger than the line width W2 [μm] on the upper surface side, the exposure light is not irradiated onto the portion of the black photosensitive layer corresponding to the line width W1 [μm] on the transparent substrate surface side of the opaque wiring electrode pattern, so that a blackening layer can be formed on the side of the portion where the line width of the opaque wiring electrode is smaller than the line width W1 [μm] on the transparent substrate surface side of the opaque wiring electrode pattern.
[0046] Examples of exposure light sources include mercury lamps, halogen lamps, xenon lamps, LED lamps (365 nm, 405 nm), semiconductor lasers, KrF or ArF excimer lasers, etc. Among these, the i-line (wavelength 365 nm) of a mercury lamp and LED lamps (365 nm, 405 nm) are preferred, and LED lamps (365 nm) are more preferred due to their high output. The exposure light may be irradiated while the substrate is stationary, or may be irradiated while transporting the substrate over the light source in a direction in which the exposure light is irradiated onto the surface opposite the surface on which the black photosensitive layer is formed.
[0047] By developing the exposed black photosensitive layer, the exposed areas can be removed and a blackened layer can be formed in the unexposed areas on the top and sides of the opaque wiring electrode pattern.
[0048] The developer is preferably one that does not inhibit the conductivity of the electrode pattern, and is preferably an alkaline developer. Examples of alkaline developers include those exemplified as developers in International Publication No. 2018 / 168325. Examples of the developing method include a method of spraying the developer onto the surface of the black photosensitive layer while the substrate is left standing or rotating, a method of immersing the black photosensitive layer in the developer, and a method of applying ultrasonic waves while immersing the black photosensitive layer in the developer.
[0049] The blackened layer obtained by development may be subjected to a rinse treatment with a rinse liquid. Examples of the rinse liquid include those exemplified as rinse liquids in WO 2018 / 168325.
[0050] The obtained substrate with wiring may be further heated at 100°C to 300°C. Heating increases the hardness of the blackened layer, suppresses chipping or peeling due to contact with other members, and further improves adhesion to the substrate and wiring. Examples of heating methods include heating with an oven, an inert oven, or a hot plate, and heating with electromagnetic waves such as an infrared heater.
[0051] (Transparent Protective Layer Forming Step) When the wired substrate of the present invention further has a transparent protective layer, it is preferable to form the transparent protective layer after forming the blackened layer. Examples of methods for forming the transparent protective layer include a method of applying a transparent resin composition and drying it, a method of transferring a transparent resin layer formed on a release substrate, and a method of laminating a transparent adhesive film to the side on which the opaque wiring electrode is formed.
[0052] The present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto. The materials used in each example are as follows.
[0053] (Production Example 1: Acrylic Resin Having Carboxy Groups) 150 g of diethylene glycol monoethyl ether acetate (hereinafter "DMEA") was charged into a reaction vessel under a nitrogen atmosphere and heated to 80°C using an oil bath. To this was added dropwise a mixture consisting of 20 g of ethyl acrylate (hereinafter "EA"), 40 g of 2-ethylhexyl methacrylate (hereinafter "2-EHMA"), 20 g of styrene (hereinafter "St"), 15 g of acrylic acid (hereinafter "AA"), 0.8 g of 2,2'-azobisisobutyronitrile, and 10 g of DMEA over 1 hour. After completion of the dropwise addition, the mixture was stirred for an additional 6 hours to allow the polymerization reaction to proceed. Thereafter, 1 g of hydroquinone monomethyl ether was added to terminate the polymerization reaction. Subsequently, a mixture consisting of 5 g of glycidyl methacrylate (hereinafter "GMA"), 1 g of triethylbenzylammonium chloride, and 10 g of DMEA was added dropwise over 0.5 hours. After the dropwise addition was completed, the mixture was stirred for an additional 2 hours to carry out the addition reaction. The resulting reaction solution was purified with methanol to remove unreacted impurities, and then vacuum dried for 24 hours to obtain an acrylic resin having carboxy groups with a copolymerization ratio (by mass): EA / 2-EHMA / St / GMA / AA=20 / 40 / 20 / 5 / 15. The acid value of the resulting acrylic resin having carboxy groups was measured in accordance with JIS K 0070 (1992) and found to be 103 mgKOH / g. The weight-average molecular weight of the resulting acrylic resin having carboxy groups was 17,000.
[0054] (Production Example 2: Quinonediazide Compound) 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-naphthoquinonediazide sulfonyl chloride were dissolved in 450 g of 1,4-dioxane and the solution was cooled to room temperature. To this solution, 15.18 g of triethylamine mixed with 50 g of 1,4-dioxane was added dropwise so that the temperature in the system did not exceed 35°C. After the dropwise addition, the mixture was stirred at 30°C for 2 hours. The triethylamine salt was filtered, and the filtrate was poured into water. The precipitate was then collected by filtration. This precipitate was dried in a vacuum dryer to obtain a quinonediazide compound.
[0055] (Production Example 3: Photosensitive conductive paste) Into a 100 mL clean bottle were placed 3.0 g of the acrylic resin having a carboxy group obtained in Production Example 1, 0.3 g of a photopolymerization initiator N-1919 (manufactured by ADEK Corporation), 1.2 g of the monomer "Light Acrylate (registered trademark)" BP-4EA, 0.5 g of a dispersant "BYK (registered trademark)"-LP21116 (manufactured by BYK-Chemie), 79.0 g of propylene glycol monomethyl ether acetate (hereinafter referred to as "PGMEA"), and 16.0 g of silver fine particles (manufactured by Nisshin Engineering Inc.) having an average surface carbon coating layer thickness of 1 nm and a particle diameter of 40 nm, and the mixture was mixed using "Awatori Rentaro (registered trademark)" ARE-310 (manufactured by Thinky Corporation) to obtain 100.0 g of a 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 was found to be 3 mPa·s.
[0056] (Production Example 4: Positive-type photosensitive resin composition containing resin and colorant) Into a 100 mL clean bottle were placed 3.34 g of phenol novolak resin WR-104 (manufactured by DIC Corporation) as an alkali-soluble resin, 0.57 g of the quinone diazide compound obtained in Production Example 2 as a quinone diazide compound, 0.26 g of carboxybenzotriazole "VERZONE (registered trademark)" C-BTA (manufactured by Daiwa Chemical Industry Co., Ltd.), 0.02 g of leveling agent "BYK (registered trademark)"-331 (manufactured by BYK-Chemie), and 43.73 g of PGMEA, and the mixture was mixed using a rotation-revolution vacuum mixer "Awatori Rentaro (registered trademark)" ARE-310 (manufactured by Thinky Corporation) to obtain 47.92 g of a resin solution. 47.92 g of the resulting resin solution, 1.71 g of titanium nitride particles (particle diameter 17 nm), and 0.37 g of dispersant "BYK"-LP21116 (manufactured by BYK-Chemie) were mixed and kneaded using an Ultra Apex Mill (manufactured by Kotobuki Industries Co., Ltd.) equipped with a centrifugal separator filled with 70% by volume of 0.10 mmφ zirconia beads (manufactured by Toray Industries, Inc.), to obtain 50.0 g of a positive photosensitive resin composition.
[0057] (Production Example 5: Aqueous solution for blackening electrodes) 25.0 g of hydrochloric acid with a concentration of 36% by mass and 0.5 g of tellurium dioxide were mixed, and after the tellurium dioxide was dissolved, 10.0 g of acetic acid and 64.5 g of water were added and further mixed to obtain 100.0 g of an aqueous solution for blackening electrodes. The pH of the obtained aqueous solution for blackening electrodes was measured at 25°C using a pH meter (AP-20, manufactured by A&D Co., Ltd.) and was found to be 0.
[0058] The evaluations in the examples and comparative examples were carried out by the following methods.
[0059] (1) Thickness of Opaque Wiring Electrode Pattern The thickness of the opaque wiring electrode pattern was measured at one randomly selected location on the opaque wiring electrode pattern obtained in the opaque wiring electrode pattern forming process of each Example and Comparative Example using a stylus-type step profiler "Surfcom (registered trademark)" 1400 (manufactured by Tokyo Seimitsu Co., Ltd.).
[0060] (2) Light Transmittance of Opaque Wiring Electrode Pattern The light transmittance at a wavelength of 365 nm was measured for the pad portion of the opaque wiring electrode pattern obtained in the opaque wiring electrode pattern forming process of each Example and Comparative Example using a microsurface spectrophotometer (VSS 400: manufactured by Nippon Denshoku Industries Co., Ltd.).
[0061] (3) Line Width: Of the mesh-shaped opaque wiring electrode patterns of the wired substrates obtained in Examples 1 to 3 and Comparative Examples 1 to 4, one randomly selected location from the straight line portions was cut using a glass cutter in a direction perpendicular to the long axis (short axis direction). Furthermore, of the mesh-shaped opaque wiring electrode patterns of the wired substrates obtained in Examples 4 and 5, one randomly selected location from the straight line portions was cut using a single-edged razor in a direction perpendicular to the long axis (short axis direction). The cross section was smoothed using an IB-9010CP ion milling machine (manufactured by JEOL Ltd.), and the cross section was observed using a field emission analytical scanning electron microscope JSM-7610F (manufactured by JEOL Ltd.). The line width W1 [μm] of the opaque wiring electrode pattern on the transparent substrate side, the line width W2 [μm] of the opaque wiring electrode pattern on the upper surface side, and the line width W3 [μm] of the blackened layer were measured.
[0062] (4) Conductivity For the wired substrates obtained in each Example and Comparative Example, the resistance between the terminals was measured using a resistance tester. If the resistance was 10,000 Ω or more, or if the resistance was too high to be measured with the tester, it was rated as "NG." The distance between the terminals was 17 mm, the width was 15 mm, and the pad portion 6 of the electrode pattern for evaluating conductivity and visibility shown in Figure 4 was 2 mm long and 15 mm wide.
[0063] (5) Difficulty in visibility from the front [person] For the wired substrates obtained in each Example and Comparative Example, a black sheet SuperBlackIR (manufactured by Systems Engineering Co., Ltd.) was placed on the transparent substrate surface so that the opaque wiring pattern-forming surface could be seen, and then light was projected perpendicularly onto the wired substrate using a floodlight. Ten people each visually inspected the wired substrate perpendicularly from a distance of 30 cm, and the difficulty in visibility was evaluated based on the number of people who could see the mesh-shaped wiring.
[0064] (6) Difficulty in visibility from oblique directions [people] For the wired substrates obtained in each of the Examples and Comparative Examples, a black sheet SuperBlackIR (manufactured by Systems Engineering Co., Ltd.) was placed on the surface of the transparent substrate so that the transparent wiring pattern-forming surface could be seen, and then light was projected perpendicularly onto the wired substrate using a floodlight. Ten people each visually inspected the wired substrate from a 45-degree angle from a position 30 cm away, and the difficulty in visibility was evaluated based on the number of people who could see the mesh-shaped wiring.
[0065] (7) Difficulty in visibility from the substrate surface [human] For the wired substrates obtained in each Example and Comparative Example, a black sheet SuperBlackIR (manufactured by Systems Engineering Co., Ltd.) was placed on the surface on which the opaque wiring pattern was formed so that the substrate side was visible, and then light was projected perpendicularly onto the wired substrate using a floodlight. Ten people each visually inspected the wired substrate from a 45-degree angle from a position 30 cm away, and the difficulty in visibility was evaluated based on the number of people who could see the mesh-shaped wiring.
[0066] (8) Light Transmittance The total light transmittance of the mesh-shaped patterned portion of the wired substrate obtained in each of the Examples and Comparative Examples was measured using a spectral haze meter (HSP-150Vis, manufactured by Murakami Color Research Laboratory Co., Ltd.).
[0067] Example 1 <Process for Forming an Opaque Wiring Electrode Pattern> The photosensitive conductive paste obtained in Production Example 3 was applied by spin coating to one surface of alkali-free glass "AN Wizus (registered trademark)" (manufactured by AGC Inc., light transmittance at a wavelength of 365 nm: 91%, light transmittance at a wavelength of 550 nm: 92%, thickness: 0.5 mm) so that the thickness after drying would be 1 μm, and the paste was dried at 90° C. for 8 minutes. Using an exposure device (PEM-6M; manufactured by Union Optical Co., Ltd.) with an exposure mask having a pad portion 6 and a mesh-shaped pattern as shown in FIG. 4, an exposure gap of 50 μm and an exposure dose of 150 mJ / cm were used. ２The pattern was exposed to light at a wavelength of 365 nm (equivalent to a wavelength of 365 nm). The mesh-shaped pattern shown in FIG. 5 had a mesh pitch 7 of 150 μm, a mesh angle 8 of 90°, and a negative pattern having openings 10 with a width of 4 μm and a light-shielding portion 9. The pattern was then developed using a 0.1% by mass aqueous solution of tetramethylammonium hydroxide as a developer for a time twice as long as the time it took for the exposed portions to dissolve. The pattern was then rinsed with ultrapure water for 30 seconds, and then heated and 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 above-mentioned method was 0.5 μm. Furthermore, the light transmittance of the opaque wiring electrode pattern measured by the above-mentioned method at a wavelength of 365 nm was 0%.
[0068] <Step of forming black photosensitive layer> A positive photosensitive resin composition containing the resin and colorant obtained in Production Example 4 was spin-coated onto the opaque wiring electrode pattern formed in the <Step of forming opaque wiring electrode pattern> so that the thickness after drying would be 3 μm, and the coating was dried at 100° C. for 5 minutes to form a black photosensitive layer.
[0069] <Blackening Layer Forming Step> The black photosensitive layer formed in the <Black Photosensitive Layer Forming Step> was exposed to light from the side opposite the opaque wiring electrode formation surface using an exposure device (PEM-6M) at an exposure dose (equivalent to a wavelength of 365 nm) of 3,000 mJ / cm. ２ The exposed substrate was then developed using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide as a developer until the transparent substrate was exposed in the exposed areas, forming blackened layers on the top and sides of the opaque wiring electrode pattern. The substrate was then heated in a box oven at 220°C for 60 minutes to obtain a substrate with wiring.
[0070] (Example 2) A substrate with wiring was obtained in the same manner as (Example 1), except that in the <opaque wiring electrode pattern forming step>, the photosensitive conductive paste was applied so that the coating thickness after drying was 2.5 μm.
[0071] (Example 3) In the <Black Photosensitive Layer Forming Step>, the exposure dose was 5,000 mJ / cm ２A substrate with wires was obtained in the same manner as in Example 1, except that the development time was 1.5 times the time required for the exposed portion of the transparent substrate to become exposed.
[0072] Example 4 <Opaque Wiring Electrode Pattern Formation Process> A 0.2 μm thick chromium film was formed as an underlayer (adhesion layer) on one side of a PET film "Lumirror (registered trademark)" T60 (manufactured by Toray Industries, Inc., thickness: 75 μm, light transmittance at a wavelength of 365 nm: 77%, light transmittance at a wavelength of 550 nm: 89%) by a sputtering method, and then a 2.0 μm thick copper film was formed on the entire surface by a vapor deposition method. Next, resist LC-140 (manufactured by Rohm and Haas Electronic Materials Co., Ltd.) was spin-coated onto the copper film and dried at 100° C. for 5 minutes. Next, an exposure device (PEM-6M; manufactured by Union Optical Co., Ltd.) was used to apply an exposure mask having a pad portion 6 and a mesh-shaped pattern as shown in FIG. 4 to the copper film at an exposure dose of 45 mJ / cm. ２ The pattern was exposed to light at a wavelength of 365 nm (equivalent to a wavelength of 365 nm). Here, the mesh-shaped pattern shown in FIG. 6 has a mesh pitch 7 of 150 μm, a mesh angle 8 of 90°, and is a positive pattern having openings 10 and a light-shielding portion 9 with a light-shielding width of 16 μm. Thereafter, immersion development was performed for 30 seconds using a 2.38 mass% tetramethylammonium hydroxide aqueous solution as a developer, and then rinsed with ultrapure water for 30 seconds. Next, the copper film and chromium film were etched using a ferric chloride aqueous solution to a line width of 4.5 μm, and then rinsed with ultrapure water for 30 seconds. Next, immersion development was performed for 4 minutes using resist stripper JELK-101 (manufactured by Kanto Chemical Co., Ltd.), and then rinsed with ultrapure water for 30 seconds to form an opaque wiring electrode pattern. The thickness of the opaque wiring electrode pattern measured by the above-mentioned method was 2.5 μm. Furthermore, the light transmittance of the opaque wiring electrode pattern measured by the above-mentioned method at a wavelength of 365 nm was 0%.
[0073] <Step of Forming Black Photosensitive Layer> A black photosensitive layer was formed on the opaque wiring electrode pattern formed in the <Step of Forming Opaque Wiring Electrode Pattern> in the same manner as in Example 1.
[0074] <Blackening Layer Forming Step> A black photosensitive layer was formed in the same manner as in Example 1, except that the heating temperature of the box oven after the blackening layer formation was set to 140°C, and a substrate with wires was obtained.
[0075] Example 5 A substrate with wires was obtained in the same manner as in Example 4, except that the chromium film formed as the underlayer in the <opaque wiring electrode pattern forming step> was changed to a copper nitride film (black layer).
[0076] Comparative Example 1 A substrate with wires was obtained in the same manner as in Example 1, except that the exposure gap in the <opaque wiring electrode pattern forming step> was changed to 0 μm.
[0077] Comparative Example 2 A substrate with wires was obtained in the same manner as in Example 2, except that the exposure gap in the <opaque wiring electrode pattern forming step> was changed to 0 μm.
[0078] Comparative Example 3 <Opaque Wiring Electrode Pattern Forming Step> An opaque wiring electrode pattern was formed in the same manner as in Example 1.
[0079] <Blackening Layer Forming Step> The opaque wiring electrode pattern formed in the <Opaque wiring electrode pattern forming step> was immersed for 30 seconds in the electrode blackening aqueous solution obtained in Production Example 5, and then washed with water and dried to form a blackening layer on the top and sides of the opaque wiring electrode pattern, thereby obtaining a substrate with wiring.
[0080] Comparative Example 4 <Opaque Wiring Electrode Pattern Forming Step> An opaque wiring electrode pattern was formed in the same manner as in Comparative Example 1.
[0081] <Step of Forming Black Photosensitive Layer> A black photosensitive layer was formed in the same manner as in (Comparative Example 1).
[0082] <Blackening Layer Forming Step> For the black photosensitive layer formed in the <Black Photosensitive Layer Forming Step>, an exposure mask having a pad portion 6 and a mesh-shaped pattern as shown in FIG. 4 was placed so that the opaque wiring electrode pattern formed in the <Opaque Wiring Electrode Pattern Forming Step> and the mask light-shielding portion overlapped, and an exposure device (PEM-6M; manufactured by Union Optical Co., Ltd.) was used to expose the black photosensitive layer to light at an exposure dose of 3,000 mJ / cm through the above-mentioned exposure mask.２ The substrate was exposed to light at a wavelength of 365 nm (equivalent to a wavelength of 365 nm). The mesh-shaped pattern shown in FIG. 6 had a mesh pitch 7 of 150 μm and a mesh angle 8 of 90°, and was a positive pattern having openings 10 and light-shielding portions 9 with a light-shielding width of 9 μm. Development was then carried out using a 2.38% by mass aqueous solution of tetramethylammonium hydroxide as a developer until the transparent substrate in the exposed areas was exposed, forming a blackened layer on the top and sides of the opaque wiring electrode pattern. The substrate was then heated in a box oven at 220° C. for 60 minutes to obtain a substrate with wiring.
[0083] The evaluation results of each of the examples and comparative examples are shown in Table 1.
[0084]
[0085] 1: Transparent substrate 2: Opaque wiring electrode pattern 3: Blackened layer 4: Wired substrate 5: Underlayer (black layer) 6: Pad portion 7: Mesh pitch 8: Mesh angle 9: Light-shielding portion 10: Opening W1: Line width of the opaque wiring electrode pattern on the transparent substrate surface side W2: Line width of the opaque wiring electrode pattern on the upper surface side W3: Line width of the blackened layer
Claims
1. A wiring substrate having an opaque wiring electrode pattern on a transparent substrate, wherein the opaque wiring electrode pattern has a blackening layer containing a resin and a coloring agent on the upper and side portions, 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 relationship in formula (1) below. W1≧W3>W2 (1)
2. The wiring substrate according to claim 1, wherein the opaque wiring electrode pattern has a black layer on the transparent substrate side.
3. The wired substrate according to claim 1 or 2, wherein the thickness T1 [μm] of the opaque wiring electrode pattern is 1.0 to 10.
0.
4. The wired substrate according to claim 1 or 2, wherein the difference between the line widths W1 and W2 of the opaque wiring electrode pattern is 0.1 μm or more and 2.0 μm or less.
5. A method for manufacturing a substrate with wiring according to claim 1 or 2, A process of forming an opaque wiring electrode pattern on a transparent substrate, with a line width W1 [μm] on the transparent substrate side and a line width W2 [μm] on the upper surface side. A step of forming a black photosensitive layer on the opaque wiring electrode pattern forming surface of the transparent substrate by applying a positive-type photosensitive resin composition containing a resin and a colorant, and A step of forming a blackened layer with a line width W3 [μm] on the upper and side portions of the opaque wiring electrode pattern by exposing the black photosensitive layer to the opaque wiring electrode pattern using the opaque wiring electrode pattern as a mask and developing it. A method for manufacturing a substrate with wiring.