WO2024135082A1 - Wiring board, positive photosensitive resin composition for forming light-blocking layer, light-blocking layer transfer film, and wiring board manufacturing method - Google Patents

Abstract

Provided are a wiring base material having excellent design visibility, and a positive photosensitive resin composition for forming a light-blocking layer suitable for the wiring base material. The wiring base material has, on a transparent base material, a multilayer pattern of an opaque wiring electrode and a light-blocking layer containing a resin and a colored component. An average value R1 of internal diffuse reflectance at a wavelength of 540-570 nm measured from the light-blocking layer side of a multilayer pattern forming portion is 0.03-0.11%.

Description

Wiring board, positive-type photosensitive resin composition for forming light-shielding layer, light-shielding layer transfer film, and method for manufacturing wiring board

The present invention relates to a wiring board, a positive-type photosensitive resin composition for forming a light-shielding layer, a light-shielding layer transfer film, and a method for manufacturing a wiring substrate.

In recent years, touch panels, which have been widely used as input means, are composed of a display unit such as a liquid crystal panel and a touch panel sensor that detects information input at a specific position. Transparent wiring electrodes have been generally used as wiring electrodes for touch panel sensors in order to make the wiring electrodes less visible, but in recent years, opaque wiring electrodes made of metal materials have become more widespread due to increased sensitivity and larger screens. Opaque wiring electrodes made of metal materials have the problem of being easily visible due to their metallic luster. As a method for making the opaque wiring electrodes less visible, a wiring board has been proposed that has a transparent substrate, an opaque wiring electrode patterned on at least one side of the transparent substrate, and a transparent protective layer formed on the transparent substrate and the opaque wiring electrode, in which the internal reflectance R1 at the opaque wiring electrode formation portion measured from the transparent protective layer side of the wiring board is 0.1% or less, and the refractive index n1 of the transparent substrate and the refractive index n2 of the transparent protective layer satisfy a specific relationship, particularly a wiring board having a light-shielding layer on the top of the opaque wiring electrode (see, for example, Patent Document 1). In addition, as a positive-type photosensitive composition used in a light-shielding layer, a photosensitive resin composition containing a pigment, a novolac resin, an acrylic resin having a carboxyl group, a photoacid generator, and an amine-based dispersant (see, for example, Patent Document 2), and a positive-type photosensitive resin composition containing an alkali-soluble resin (A) having an acrylic group and/or a methacrylic group in the side chain, a photosensitizer (B), and a colorant (C) (see, for example, Patent Document 3) have been proposed.

International Publication No. 2022/130803 JP 2021-139971 A International Publication No. 2021/149410

The light-shielding layers disclosed in Patent Documents 1 to 3 can reduce the visibility of the opaque wiring electrodes due to their metallic luster, but external light is easily reflected, particularly in bright locations such as in-vehicle applications, and light scattering on the surface of the wiring substrate tends to cause the laminated pattern-forming areas to appear whitish and cloudy compared to areas where the laminated pattern is not formed and decorative areas. In applications where jet black is required from a design perspective, there is a demand to reduce this whitish cloudiness, i.e., to improve design visibility.

The present invention aims to provide a wiring substrate with excellent design visibility and a positive-type photosensitive resin composition suitable for forming a light-shielding layer.

In order to solve the above problems, the present invention mainly has the following configuration.
<1> A wiring substrate having a laminated pattern of an opaque wiring electrode and a light-shielding layer containing a resin and a coloring component on a transparent substrate, the wiring substrate having an average internal diffuse reflectance R1 of 0.03 to 0.11% at a wavelength of 540 to 570 nm as measured from the light-shielding layer side of the laminated pattern forming portion.
<2> The wiring substrate according to <1>, wherein an average value R1 [%] of the internal diffuse reflectance at a wavelength of 540 to 570 nm measured from the light-shielding layer side of the laminate pattern forming portion, an average value R2 [%] of the internal diffuse reflectance at a wavelength of 540 to 570 nm of the laminate pattern non-forming portion, a line width W [μm] of the laminate pattern, and a ratio S of the laminate pattern area to the area of the laminate pattern forming portion (laminate pattern area/laminate pattern forming portion area) satisfy the relationship of the following formula (1).
0.0≦((R1×W)−(R2×(1−S)))/S≦7.0 (1)
<3> The wiring substrate according to <1> or <2>, wherein the thickness T1 [μm] of the light-shielding layer is 0.2 to 2.0 μm.
<4> A positive-type photosensitive resin composition for forming a light-shielding layer, comprising (a) an alkali-soluble resin, (b) a quinone diazide compound, (c) metal nitride particles, and (d) a purple organic pigment.
<5> The positive photosensitive resin composition for forming a light-shielding layer according to <4>, wherein the content of the (c) metal nitride particles is 2.0 to 6.0% by volume.
<6> The positive photosensitive resin composition for forming a light-shielding layer according to <4> or <5>, further comprising (e) a red organic pigment.
<7> The positive photosensitive resin composition for forming a light-shielding layer according to <6>, wherein the total content of (c) the metal nitride particles, (d) the purple organic pigment and (e) the red organic pigment is 5 to 15 volume %.
<8> A light-shielding layer transfer film having a light-shielding layer formed from the positive photosensitive resin composition for forming a light-shielding layer according to any one of <4> to <7> on a release film.
<9> The light-shielding layer transfer film according to <8>, wherein the thickness T1′ [μm] of the light-shielding layer is 0.3 to 2.0 μm.
<10> A step of forming an opaque wiring electrode on a transparent substrate;
A step of applying a positive photosensitive resin composition for forming a light-shielding layer according to any one of <4> to <7> to the opaque wiring electrode formation surface; and
a step of exposing the photosensitive resin composition coating film from the side opposite to the coating side using the opaque wiring electrode as a mask, and developing the photosensitive resin composition coating film to pattern the photosensitive resin composition coating film to form a laminated pattern of the opaque wiring electrode and the light-shielding layer;
The method for producing a wiring substrate according to any one of <1> to <3>,
<11> A step of forming an opaque wiring electrode on a transparent substrate;
A step of transferring a light-shielding layer of the light-shielding layer transfer film according to item <8> or <9> onto the opaque wiring electrode formation surface; and
a step of exposing the light-shielding layer from a surface opposite to a transfer surface using the opaque wiring electrode as a mask, and developing the light-shielding layer to pattern the light-shielding layer to form a laminated pattern of the opaque wiring electrode and the light-shielding layer;
The method for producing a wiring substrate according to any one of <1> to <3>,

The wiring substrate of the present invention has excellent design visibility. By using the positive photosensitive resin composition for forming a light-shielding layer of the present invention, a wiring substrate with excellent design visibility can be obtained.

1 is a schematic diagram showing an example of a configuration of a wiring substrate of the present invention. FIG. 4 is a schematic diagram showing another example of the configuration of the wiring substrate of the present invention. FIG. 1 is a schematic diagram showing an example of the configuration of a substrate for evaluating internal diffuse reflectance in the present invention. FIG. 2 is a schematic diagram showing an electrode pattern for evaluating visibility used in the examples and comparative examples. FIG. 2 is a schematic diagram of a mesh pattern of a negative mask used in the examples and comparative examples.

First, the wiring substrate will be described as the first aspect of the present invention. The wiring substrate of the present invention has an opaque wiring electrode on a transparent substrate, and a light-shielding layer at a portion corresponding to the opaque wiring electrode. That is, it has a laminated pattern of an opaque wiring electrode and a light-shielding layer. The light-shielding layer may be on the opaque wiring electrode, or the opaque wiring electrode may be on the light-shielding layer. The light-shielding layer has the effect of suppressing the light reflection and light scattering of the opaque wiring electrode, reproducing a jet black color with high designability, and improving the visibility of the design. Furthermore, a transparent protective layer may be formed on these, and by having the transparent protective layer, the surface of the opaque wiring electrode and the light-shielding layer can be protected and scratches can be suppressed. Here, "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).

Figure 1 shows a schematic diagram of an example of the configuration of a wiring substrate of the present invention. The wiring substrate 4 has an opaque wiring electrode 2 on a transparent substrate 1, and a light-shielding layer 3 on the opaque wiring electrode 2. Figure 2 shows another example of the configuration of a wiring substrate of the present invention. The wiring substrate 4 has a light-shielding layer 3 on a transparent substrate 1, and a opaque wiring electrode 2 on the light-shielding layer 3.

The wiring substrate of the present invention has a laminated pattern of an opaque wiring electrode and a light-shielding layer containing a resin and a coloring component. In the present invention, the average internal diffuse reflectance R1 at wavelengths of 540 to 570 nm measured from the light-shielding layer side of the laminated pattern forming portion is 0.03 to 0.11%. Here, the laminated pattern forming portion means the area in which the laminated pattern is formed, and includes the portion corresponding to the laminated pattern as well as the non-laminated pattern portion located between adjacent laminated patterns with a distance of less than 1 mm. More specifically, for example, in the case of a striped laminated pattern, the portion corresponding to the striped laminated pattern with a pitch of less than 1 mm and the non-laminated pattern portion sandwiched between the laminated patterns are collectively referred to as the laminated pattern forming portion. In addition, for example, in the case of a mesh-shaped laminated pattern as shown in FIG. 5, the portion corresponding to the mesh-shaped laminated pattern with a mesh pitch of less than 1 mm (laminated pattern portion 12) and the non-laminated pattern portion (non-laminated pattern portion 13) surrounded by the laminated patterns are collectively referred to as the laminated pattern forming portion. On the other hand, a non-laminated pattern portion where the distance between adjacent laminated patterns is 1 mm or more is defined as a laminated pattern non-forming portion. As described above, the conventionally known light-shielding layer can suppress the visibility of the opaque wiring electrode due to its metallic luster, but the laminated pattern forming portion tends to look white and cloudy due to light scattering on the wiring substrate surface, especially in bright places. The inventors' study revealed that the total reflectance (SCI) of the laminated pattern forming portion can be reduced by laminating a conventionally known light-shielding layer on the opaque wiring electrode, but the diffuse reflectance (SCE) is higher than that of a transparent wiring electrode such as ITO. Therefore, the inventors studied the relationship between the design visibility problem due to light scattering on the wiring substrate surface and the diffuse reflectance, and focused on the diffuse reflectance in the wavelength range of 540 to 570 nm, where visibility is high. The average internal diffuse reflectance R1 at wavelengths of 540 to 570 nm measured from the light-shielding layer side of the laminate pattern forming portion is an index of diffuse reflectance in a wavelength region with high visibility, and by making R1 0.03 or more, it is possible to prevent the boundary between the laminate pattern forming portion and the laminate pattern non-forming portion from being visible due to the difference in diffuse reflectance between the laminate pattern forming portion and the laminate pattern non-forming portion. R1 is preferably 0.04 or more. On the other hand, by making R1 0.11% or less, it is possible to prevent the clouding of the laminate pattern forming portion due to light scattering on the wiring substrate surface even in particularly bright places, reproduce a highly decorative jet black, and improve design visibility.

Here, the internal diffuse reflectance corresponds to the diffuse reflectance from which the reflection caused by the refractive index difference at the interface between the wiring substrate surface and air has been removed. FIG. 3 shows a schematic diagram of an example of the configuration of an internal diffuse reflectance evaluation substrate for evaluating the internal diffuse reflectance of a wiring substrate. The wiring substrate 4 has a laminated pattern of an opaque wiring electrode 2 and a light-shielding layer 3 on a transparent substrate 1, and further has a transparent protective layer 6. An anti-reflection film 8 is attached to the light-shielding layer forming surface of the wiring substrate (here, on the transparent protective layer 6) via an adhesive layer 7, and a black film 9 is attached to the surface of the transparent substrate 1 opposite the light-shielding layer via an adhesive layer 7 to prepare an internal diffuse reflectance evaluation substrate 16 in which reflection at the wiring substrate-air interface is reduced. Although not shown, when the wiring substrate is a transparent substrate and the laminated pattern of the light-shielding layer and the opaque wiring electrode has a light-shielding layer on the transparent substrate side, an anti-reflection film is attached to the transparent substrate via a transparent adhesive layer, and a black film is attached to the transparent protective layer via an adhesive layer to reduce reflection at the interface between the wiring substrate and the air, to prepare a substrate for evaluating internal diffuse reflectance. For the laminated pattern forming portion of the obtained substrate for evaluating internal diffuse reflectance, the diffuse reflectance at wavelengths of 540, 550, 560, and 570 nm is measured using a colorimetric system or the like from the light-shielding layer forming side, that is, from the anti-reflection film 8 side in the case of the configuration shown in FIG. 3, and the average value is calculated to calculate the average value R1 of the internal diffuse reflectance.

The diffuse reflectance is affected by the reflectance of the material forming the light-shielding layer itself, the line width, area, and uneven shape of the light-shielding layer. For example, when the area of the light-shielding layer is the same, the thinner the line width W, the closer the wiring substrate surface is to the diffusing surface, and the internal diffuse reflectance tends to be higher due to the uneven shape of the light-shielding layer. Examples of methods for making R1 0.03 to 0.11% include a method in which the ratio of the laminate pattern area to the area of the laminate pattern forming part (laminated pattern area/laminate pattern forming part area, hereinafter "occupancy rate") S, the laminate pattern line width W, and the light-shielding layer thickness T1 are set to the preferred ranges described later, and a method in which the light-shielding layer is formed from the positive-type photosensitive resin composition for forming a light-shielding layer of the present invention described later are formed. Among these, the method of forming the light-shielding layer from the positive-type photosensitive resin composition for forming a light-shielding layer of the present invention described later is preferred because there are fewer restrictions on the wiring pattern.

In the wiring substrate of the present invention, it is preferable that the average internal diffuse reflectance R1 [%], the average internal diffuse reflectance R2 [%] at a wavelength of 540 to 570 nm of the laminate pattern non-forming portion, and the occupancy rate S satisfy the relationship of the following formula (1).
0.0≦((R1×W)−(R2×(1−S)))/S≦7.0 (1)
In the laminated pattern forming portion, the reflection and scattering of the wiring surface in the area ratio S (laminate pattern portion) and the reflection and scattering of the non-wiring surface in the area ratio (1-S) (non-laminate pattern portion) affect the diffuse reflectance. As described above, the diffuse reflectance is affected by the area and unevenness of the light-shielding layer. (R1×W) in the above formula (1) is an index of diffuse reflectance in the laminated pattern forming portion excluding the influence of the line width. On the other hand, in the non-laminated pattern portion, the reflection and scattering of the non-wiring surface in the area ratio (1-S) affects the diffuse reflectance. The average value R2 of the internal diffuse reflectance at wavelengths of 540 to 570 nm in the laminated pattern non-forming portion is an index of diffuse reflectance in a wavelength region with high visibility, and (R2×(1-S)) in the above formula (1) is an index of diffuse reflectance of the non-wiring surface in the laminated pattern forming portion. Then, the difference between them (i.e., the diffuse reflection of the wiring surface in the laminate pattern forming portion) was divided by the area ratio S, and the diffuse reflection of the wiring surface per unit area was focused on. By these satisfying the relationship of the above formula (1), the wiring pattern is less restricted, and the design visibility can be further improved. Here, the average value R2 of the internal diffuse reflectance at a wavelength of 540 to 570 nm of the laminate pattern non-forming portion can be calculated in the same manner as the above-mentioned R1 for the laminate pattern non-forming portion. The value of ((R1×W)−(R2×(1−S)))/S (hereinafter, sometimes referred to as “diffuse reflection per unit area”) is more preferably 6.0 or less. As a method for satisfying the above formula (1), for example, a method of forming a light-shielding layer using the positive photosensitive resin composition for forming a light-shielding layer of the present invention described later can be mentioned.

The opaque wiring electrode preferably has a light transmittance of 25% or less at a wavelength of 550 nm. It is also preferable that the opaque wiring electrode has light-shielding properties against the exposure light used in the method for forming a light-shielding layer described below. Specifically, the light transmittance at a wavelength of 365 nm is preferably 15% or less. By making the light transmittance at a wavelength of 365 nm 15% or less, the function as a mask is improved in the method for forming a light-shielding layer described below, and the desired light-shielding layer can be formed with greater ease of processing. The light transmittance of the opaque wiring electrode can be measured using a microsurface spectrophotometer (VSS 400: manufactured by Nippon Denshoku Industries Co., Ltd.) for a square opaque wiring electrode with a side length of 0.1 mm or more.

Materials constituting the opaque wiring electrode include, for example, metals such as silver, gold, copper, platinum, lead, tin, nickel, aluminum, tungsten, molybdenum, chromium, titanium, indium, etc., and conductive materials such as alloys of these. Two or more of these may be used. Among these, silver, copper, etc. are preferred from the viewpoint of conductivity.

The raw material used to form the opaque wiring electrode is preferably conductive particles containing the conductive material described above, and the shape of the particles is preferably spherical. The average particle size of the conductive particles is preferably 0.03 μm or more from the viewpoint of improving the dispersibility of the conductive particles. On the other hand, the average particle size of the conductive particles is preferably 1.0 μm or less from the viewpoint of making the edges of the pattern of the opaque wiring electrode sharp. The average particle size of the conductive particles can be obtained by observing the conductive particles at a magnification of 15,000 times using a scanning electron microscope (SEM) or a transmission electron microscope (TEM), measuring the major axis length of each of 100 randomly selected conductive particles, and calculating the number average value.

The opaque wiring electrode may contain an organic component in addition to the aforementioned conductive material. The opaque wiring electrode 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 which case the opaque wiring electrode 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.

Examples of the pattern shape of the opaque wiring electrode include a mesh shape and a stripe shape. Examples of the mesh shape include a lattice shape whose unit shapes are triangles, squares, polygons, circles, etc., or a lattice shape consisting of a combination of these unit shapes. Among these, the mesh shape is preferred from the viewpoint of making the conductivity of the pattern uniform. It is more preferable that the opaque wiring electrode is a metal mesh made of the above-mentioned metal and has a mesh-like pattern. When the opaque wiring electrode has a mesh-like pattern, the occupancy rate S can be reduced by increasing the mesh pitch.

The thickness T2 [μm] of the opaque wiring electrode is preferably 0.1 or more, and more preferably 0.3 or more, from the viewpoint of improving electrical conductivity. On the other hand, the thickness T2 [μm] of the opaque wiring electrode is preferably 10 or less, more preferably 5.0 or less, and even more preferably 3.0 or less, from the viewpoint of forming finer wiring. Furthermore, when the wiring substrate has a transparent protective layer, by setting the thickness T2 [μm] of the opaque wiring electrode to 10 or less, it is possible to reduce unevenness on the transparent substrate and suppress the generation of air bubbles due to the steps when the transparent protective layer is laminated. Note that T2 can be measured using a stylus-type step gauge.

The line width of the pattern of the opaque wiring electrode is preferably 1 μm or more, more preferably 1.5 μm or more, and even more preferably 2 μm or more, from the viewpoint of improving electrical conductivity. On the other hand, the line width of the pattern of the opaque wiring electrode is preferably 10 μm or less, more preferably 8 μm or less, from the viewpoint of further reducing the value of the internal diffuse reflectance R1 and further improving the design visibility, when the pattern shape is the same. Here, the line width of the pattern of the opaque wiring electrode can be obtained by magnifying and observing the laminated pattern formation part using an optical microscope, measuring the line width of the opaque wiring electrode at three randomly selected locations, and calculating the average value.

The wiring substrate of the present invention has a light-shielding layer that contains a resin and a coloring component.

The resin is preferably an alkali-soluble 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 novolac resins such as phenol novolac resin and cresol novolac resin, 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 included.

Coloring components include inorganic pigments, organic pigments, dyes, etc., with pigments being preferred due to their excellent weather resistance.

Organic pigments include soluble azo pigments, insoluble azo pigments, metal complex azo pigments, phthalocyanine pigments, condensed polycyclic pigments, black organic pigments such as C.I. Pigment Black 31 and 32, purple organic pigments such as C.I. Pigment Violet 19, 23, 29, 30, 32, 36, 37, 38, 39, 40, and 50, red organic pigments such as C.I. Pigment Red 9, 48, 97, 122, 123, 144, 149, 166, 168, 177, 179, 180, 190, 192, 196, 202, 209, 215, 216, 217, 220, 223, 224, 226, 227, 228, 240, 254, 255, 264, and 265, and other organic pigments such as C.I. blue organic pigments such as C.I. Pigment Blue 15, 15:1, 15:2, 15:3, 15:4, 15:6, 16, 17, 60, 64, 65, 75, 79, 80, yellow organic pigments such as C.I. Pigment Yellow 12, 13, 17, 20, 24, 74, 83, 86, 93, 95, 109, 110, 117, 120, 125, 129, 138, 139, 150, 151, 175, 180, 181, 185, 192, 194, 199, green organic pigments such as C.I. Pigment Green 7, 36, 37, Examples of orange organic pigments include Pigment Orange 1, 5, 13, 14, 16, 17, 24, 34, 36, 38, 40, 43, 46, 49, 51, 55, 59, 61, 63, 64, 71, and 73.

Inorganic pigments include carbon black, graphite, metal nitride particles such as titanium nitride and zirconium nitride, pine soot, iron oxides such as black iron, hematite, goethite and magnetite, chromium, lead, and composites of these metals. Among these, metal nitride particles are preferred because of their high transparency to the exposure light.

The coloring component preferably absorbs light at wavelengths of 540 to 570 nm, from the viewpoint of setting the average internal diffuse reflectance R1 in the aforementioned range. Examples of coloring components that absorb light at wavelengths of 540 to 570 nm include metal nitride particles, red organic pigments, purple organic pigments, and blue organic pigments. Two or more of these may be contained. Among these, when a high-pressure mercury lamp is used as the exposure light source when forming the light-shielding layer, metal nitride particles, red organic pigments, purple organic pigments, and blue organic pigments are preferred, and when an LED lamp (365 nm) is used, metal nitride particles, red organic pigments, and purple organic pigments are preferred. It is more preferred to contain metal nitride particles and purple organic pigments, which can further improve visibility after the light-shielding layer is formed while maintaining the photosensitivity when an LED lamp (365 nm) is used as the light source when forming the light-shielding layer.

The coloring component more preferably further contains a red organic pigment. By including a red organic pigment, it is possible to improve visibility after the light-shielding layer is formed while maintaining photosensitivity when an LED lamp (365 nm) is used as the light source during the formation of the light-shielding layer.

The thickness T1 [μm] of the light-shielding layer is preferably 0.2 to 2.0. By making T1 [μm] 0.2 or more, the increase in internal diffuse reflectance caused by the surface unevenness of the opaque wiring electrode can be further suppressed, and R1 can be easily adjusted within the aforementioned range. On the other hand, by making T1 [μm] 2.0 or less, the unevenness on the transparent substrate can be reduced, and the generation of air bubbles caused by the unevenness when laminating the transparent protective layer can be suppressed. Note that T1 can be measured using a stylus-type step gauge.

The line width of the light-shielding layer is preferably equal to the line width of the opaque wiring electrode described above. Therefore, from the viewpoint of improving electrical conductivity, the line width W [μm] of the laminated pattern is preferably 1 or more, more preferably 1.5 or more, and even more preferably 2 or more. On the other hand, in the case of the same pattern shape, the line width W [μm] of the laminated pattern is preferably 10 or less, more preferably 8 or less, from the viewpoint of further reducing the value of the internal diffuse reflectance R1 and further improving the design visibility. Here, the line width W of the laminated pattern can be obtained by magnifying and observing the laminated pattern formation part with an optical microscope, measuring the line width of the laminated pattern at three randomly selected points, and calculating the average value.

Next, a method for manufacturing the wiring substrate of the present invention will be described. For example, when a laminated pattern having an opaque wiring electrode and a light-shielding layer in this order is formed on a transparent substrate, the method for manufacturing the wiring substrate of the present invention preferably includes a step of forming an opaque wiring electrode on the transparent substrate (hereinafter, may be referred to as an "opaque wiring electrode forming step") and a step of forming a light-shielding layer containing a resin and a coloring component on the surface on which the opaque wiring electrode is formed to form a laminated pattern (hereinafter, may be referred to as a "laminate pattern forming step").

In the opaque wiring electrode forming process, methods for forming the opaque wiring electrode include, for example, 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, etc. using a conductive composition, a method of forming a film of a metal, a metal composite, a composite of a metal and a metal compound, a metal alloy, etc., and forming it by photolithography using a resist, etc. When the pattern formed from the photosensitive conductive composition exhibits conductivity by heat curing, it is preferable to heat cure it at 140 to 500°C.

In the laminated pattern forming process, examples of the light-shielding layer forming process include a method of applying a positive-type photosensitive resin composition for forming a light-shielding layer of the second aspect of the present invention described later onto an opaque wiring electrode, exposing the positive-type photosensitive resin composition for forming a light-shielding layer coating film from the side opposite to the coating side using the opaque wiring electrode as a mask, and developing the film to pattern the positive-type photosensitive resin composition for forming a light-shielding layer, and a method of transferring a light-shielding layer onto an opaque wiring electrode using a light-shielding layer transfer film of the present invention described later, exposing the light-shielding layer from the side opposite to the transfer side using the opaque wiring electrode as a mask, and developing the light-shielding layer to pattern the light-shielding layer. Among these, the latter method using a light-shielding layer transfer film is preferred. By transferring a light-shielding layer that maintains its shape using a light-shielding layer transfer film, it is possible to suppress the film thickness of the non-opaque wiring electrode portion from increasing due to leveling of the light-shielding layer during film formation, which would otherwise increase the required exposure amount and development time. By using these methods to pattern a light-shielding layer on an opaque wiring electrode, a laminated pattern can be formed.

Examples of exposure light sources include mercury lamps, halogen lamps, xenon lamps, LED lamps (365 nm, 405 nm), semiconductor lasers, and KrF or ArF excimer lasers. Among these, the i-line (wavelength 365 nm) of a mercury lamp and LED lamps (365 nm, 405 nm) are preferred, with LED lamps (365 nm) being even more preferred due to their high output. The exposure light may be applied while the substrate is stationary, or may be applied while the substrate is transported over the light source in a direction in which the exposure light is applied to the surface opposite the surface on which the light-shielding layer is formed.

The developer used for development 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 WO 2018/168325. Examples of the development method include a method in which the developer is sprayed onto the surface of the resin layer while the substrate is stationary or rotated, a method in which the resin layer is immersed in the developer, and a method in which ultrasonic waves are applied to the resin layer while the resin layer is immersed in the developer.

The light-shielding layer pattern obtained by development may be subjected to a rinse treatment using a rinse liquid. Examples of the rinse liquid include those exemplified as rinse liquids in WO 2018/168325.

The obtained wiring substrate may be further heated at 100 to 300°C. Heating increases the hardness of the resin 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, inert oven, or hot plate, and heating with electromagnetic waves from an infrared heater, etc.

Next, as a second embodiment of the present invention, a positive-type photosensitive resin composition for forming a light-shielding layer will be described. The positive-type photosensitive resin composition for forming a light-shielding layer of the present invention can be preferably used to form a light-shielding layer in the wiring substrate of the first embodiment of the present invention described above, and by forming a light-shielding layer from such a positive-type photosensitive resin composition for forming a light-shielding layer, the average value R1 of the internal diffuse reflectance can be easily adjusted to the aforementioned range.

The positive-type photosensitive resin composition for forming a light-shielding layer of the present invention contains (a) an alkali-soluble resin, (b) a quinone diazide compound, (c) metal nitride particles, and (d) a purple organic pigment. Here, positive-type photosensitivity refers to the property that the light-irradiated portion dissolves in the developer, and the unirradiated portion does not dissolve in the developer.

(a) Examples of the alkali-soluble resin include those exemplified for the light-shielding layer in the wiring substrate of the first embodiment of the present invention. As the alkali-soluble resin (a), a resin having a phenolic hydroxyl group is preferable, and hydrogen bonding between the phenolic hydroxyl group and the quinone diazide compound (b) can further suppress the occurrence of film loss and peeling during development in unexposed areas, making it harder to see the opaque wiring electrode pattern. As examples of the resin having a phenolic hydroxyl group, those described for the light-shielding layer in the wiring substrate of the first embodiment of the present invention can be used. The content of the alkali-soluble resin (a) in the solid content of the positive photosensitive resin composition for forming the light-shielding layer is preferably 45 to 65 mass%.

(b) Examples of the quinone diazide compound include those exemplified as quinone diazide compounds contained in the positive photosensitive composition in WO 2018/168325. The content of the quinone diazide compound in the solid content of the positive photosensitive resin composition is preferably 5 to 25 mass%.

The positive-type photosensitive resin composition for forming a light-shielding layer of the present invention contains (c) metal nitride particles and (d) purple organic pigment that absorb light in the wavelength range of 540 to 570 nm, which has high visibility, and also absorbs visible light in the wavelength range of 570 to 640 nm. This makes it possible to improve the visibility of the design after the light-shielding layer is formed while maintaining the photosensitivity when an LED lamp (365 nm) is used as the light source during the formation of the light-shielding layer. Examples of (c) metal nitride particles and (d) purple organic pigment include those described for the light-shielding layer in the wiring substrate of the first embodiment of the present invention.

The content of (c) metal nitride particles in the solid content of the positive photosensitive resin composition for forming a light-shielding layer is preferably 2.0% by volume or more, and more preferably 2.5% by volume or more, from the viewpoint of further improving the design visibility. On the other hand, the content of metal nitride particles is preferably 6.0% by volume or less, and more preferably 5.0% by volume or less, from the viewpoint of photosensitivity.

The content of the purple organic pigment (d) in the solid content of the positive photosensitive resin composition for forming a light-shielding layer is preferably 1.0% by volume or more from the viewpoint of further improving the visibility of the design. On the other hand, the content of the purple organic pigment (d) is preferably 8.0% by volume or less from the viewpoint of photosensitivity.

The positive-type photosensitive resin composition for forming a light-shielding layer of the present invention preferably further contains (e) a red organic pigment. (e) The red organic pigment absorbs light in the wavelength range of 460 to 540 nm and also absorbs visible light in the wavelength range of 570 to 640 nm, and therefore can improve the design visibility of the light-shielding layer while maintaining the photosensitivity when an LED lamp (365 nm) is used as the light source during the formation of the light-shielding layer.

When the positive photosensitive resin composition for forming a light-shielding layer of the present invention contains (e) a red organic pigment, the total content of (c) the metal nitride particles, (d) the purple organic pigment, and (e) the red organic pigment in the solid content of the positive photosensitive resin composition is preferably 5.0% by volume or more from the viewpoint of bringing the diffuse reflection per unit area into the aforementioned preferred range and further improving visibility. On the other hand, from the viewpoint of photosensitivity, the total content of these is preferably 15.0% by volume or less.

The positive-type photosensitive resin composition for forming a light-shielding layer of the present invention may contain, as necessary, a monomer having an unsaturated double bond, a photopolymerization initiator, a photoacid generator, a thermal acid generator, a sensitizer, an adhesion improver, a surfactant, a thermal curing agent, a polymerization inhibitor, a rust inhibitor, a softener, a leveling agent, and the like.

The positive-type photosensitive resin composition for forming a light-shielding layer of the present invention can be obtained, for example, by mixing (a) an alkali-soluble resin, (b) a quinone diazide compound, (c) metal nitride particles, (d) a purple organic pigment, and other additives as necessary, and then dispersing the mixture using a dispersing machine or kneading machine. Examples of dispersing machines and kneading machines include a jet mill, a bead mill, a ball mill, and a planetary ball mill.

The positive-type photosensitive resin composition for forming a light-shielding layer of the present invention can be preferably used in the light-shielding layer transfer film of the present invention, and such a light-shielding layer transfer film can be preferably used to form a light-shielding layer in the wiring substrate of the first embodiment of the present invention described above.

The light-shielding layer transfer film of the present invention has a light-shielding layer formed from the positive-type photosensitive resin composition for forming a light-shielding layer according to the second embodiment of the present invention described above on a release film.

The release film is preferably one that has a release layer on its surface.

The release agent forming the release layer may be, for example, a non-silicone release agent or a silicone release agent. Examples of the non-silicone release agent include long-chain alkyl and fluorine-based release agents. Two or more of these may be used. Among these, non-silicone release agents are preferred because, even if the release agent transfers during transfer, they are less likely to cause phenomena such as developer repelling in the subsequent process, particularly the development process, and can form a fine pattern while suppressing in-plane unevenness. The thickness of the release layer is preferably 50 nm or more from the viewpoint of suppressing transfer unevenness during transfer. On the other hand, the thickness of the release layer is preferably 500 nm or less from the viewpoint of suppressing transfer of the release agent during transfer.

The peeling strength of the release film is preferably 500 mN/20 mm or more from the viewpoint of suppressing repelling during the formation of the light-shielding layer. On the other hand, the peeling strength of the release film is preferably 5,000 mN/20 mm or less from the viewpoint of widening the process margin during the transfer of the light-shielding layer. Here, the peeling strength of the release film refers to the peeling strength when Nitto Denko Corporation's acrylic adhesive tape "31B" is applied to the surface on which the release layer is formed using a 2 kg roller, and after leaving it to stand for 30 minutes, it is peeled off under the conditions of a peeling angle of 180° and a peeling speed of 0.3 m/min.

Films used for the release film include, for example, films containing resins such as polyethylene terephthalate (PET), cycloolefin polymer, polycarbonate, polyimide, aramid, fluororesin, acrylic resin, and polyurethane resin. Two or more of these may be used. Among these, those that are transparent to the exposure light used in the aforementioned laminated pattern formation process are preferred, and films containing PET, cycloolefin polymer, and polycarbonate are preferred. By selecting a film that is transparent to the exposure light, exposure can be performed through the release film in the aforementioned laminated pattern formation process, and contamination of the photomask can be suppressed by placing a release film between the light-shielding layer and the photomask.

The thickness of the release film is preferably 5 μm or more, and more preferably 10 μm or more, from the viewpoint of improving transport stability during the formation of the light-shielding layer and suppressing unevenness in the thickness of the light-shielding layer. On the other hand, the thickness of the release film is preferably 300 μm or less, and more preferably 200 μm or less, from the viewpoint of ease of handling during peeling.

The thickness T1' [μm] of the light-shielding layer of the light-shielding layer transfer film is preferably 0.3 or more, more preferably 0.5 or more, from the viewpoint of making the opaque wiring electrode less visible. On the other hand, the thickness T1' [μm] of the light-shielding layer is preferably 2.0 or less, from the viewpoint of reducing the development time and further improving processability. Note that T1' can be measured using a stylus-type step gauge. Furthermore, when this is transferred to form a light-shielding layer on a wiring substrate, the thickness T1' of the light-shielding layer corresponds to the thickness T1, but may vary depending on the method of forming the light-shielding layer.

The light-shielding layer transfer film of the present invention can be obtained, for example, by applying a positive-type photosensitive resin composition for forming a light-shielding layer onto a release film.

Methods for applying the positive photosensitive resin composition for forming a light-shielding layer onto a release film include, for example, spin coating using a spinner, spray coating, roll coating, screen printing, or coating using a slit coater, blade coater, die coater, calendar coater, meniscus coater, or bar coater. The coating thickness of the positive photosensitive resin composition for forming a light-shielding layer is preferably set so that the thickness T1 of the light-shielding layer falls within the preferred range described above.

When the positive-type photosensitive resin composition for forming the light-shielding layer contains a solvent, it is preferable to heat-dry it. The drying temperature is preferably 60 to 120°C, and the drying time is preferably 1 to 20 minutes. As the heating and drying device, for example, an oven, a hot plate, etc. are preferable.

The present invention will be explained 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.

[(a) Alkali-soluble resin]
Phenol novolac resin WR-104 (manufactured by DIC Corporation).

[(b) Quinone diazide compound]
(Production Example 1: Quinone diazide compound)
Under a dry nitrogen stream, 21.22 g (0.05 mol) of α,α,-bis(4-hydroxyphenyl)-4-(4-hydroxy-α,α-dimethyldimethylbenzylethylbenzene (trade name TrisP-PA, manufactured by Honshu Chemical Industry Co., Ltd.) and 33.58 g (0.125 mol) of 5-naphthoquinone diazide sulfonyl chloride were dissolved in 450 g of 1,4-dioxane and the solution was cooled to room temperature. 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 that had separated out was then collected by filtration. This precipitate was dried in a vacuum dryer to obtain a quinone diazide compound.

[Coloring ingredients]
(c) Metal nitride particles: titanium nitride particles (particle diameter 17 nm)
(d) Purple organic pigment: Pigment Violet 23 (particle diameter 50 nm)
(e) Red organic pigment: Pigment Red 254 (particle diameter 100 nm)
Blue organic pigment: Pigment Blue 15:6 (particle size 100 nm)
Carbon black: MA100 (manufactured by Mitsubishi Chemical Corporation).

[others]
(Production Example 2: Acrylic resin having a carboxy group)
In a reaction vessel in a nitrogen atmosphere, 150 g of diethylene glycol monoethyl ether acetate (hereinafter, "DMEA") was charged, and the temperature was raised to 80°C using an oil bath. 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 was added dropwise over 1 hour. After the dropwise addition was completed, the mixture was stirred for another 6 hours to carry out a polymerization reaction. Then, 1 g of hydroquinone monomethyl ether was added to stop 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 another 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 another 24 hours to obtain an acrylic resin having a carboxy group with a copolymerization ratio (mass basis): EA/2-EHMA/St/GMA/AA=20/40/20/5/15. The acid value of the resulting acrylic resin having a carboxy group was measured in accordance with JIS K 0070 (1992) to find that it was 103 mgKOH/g. The weight average molecular weight of the resulting acrylic resin having a carboxy group was 17,000.

(Production Example 3: Acrylic resin having a phenolic hydroxyl group and a carboxyl group)
In a reaction vessel in a nitrogen atmosphere, 150 g of 2-methoxy-1-methylethyl acetate (hereinafter, "PMA") was charged, and the temperature was raised to 80°C using an oil bath. To this, a mixture consisting of 20 g of EA, 20 g of 2-EHMA, 20 g of 4-hydroxystyrene (hereinafter, "HS"), 15 g of N-methylol acrylamide (hereinafter, "MAA"), 25 g of AA, 0.8 g of 2,2'-azobisisobutyronitrile, and 10 g of PMA was added dropwise over 1 hour. After completion of the dropwise addition, the mixture was heated and stirred at 80°C for another 6 hours to carry out a polymerization reaction. Thereafter, 1 g of hydroquinone monomethyl ether was added to terminate the polymerization 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 a phenolic hydroxyl group and a carboxyl group with a copolymerization ratio (mass basis): EA/2-EHMA/HS/MAA/AA=20/20/20/15/25. The acid value was measured in the same manner as in Production Example 2 and found to be 153 mgKOH/g. The weight average molecular weight of the resulting acrylic resin having a phenolic hydroxyl group and a carboxyl group was 10,000.

(Production Example 4: Photosensitive conductive paste)
Into a 100 mL clean bottle, 3.0 g of the acrylic resin having a carboxy group obtained in Production Example 2, 0.3 g of a photopolymerization initiator N-1919 (manufactured by ADEK Corporation), 1.2 g of a monomer "Light Acrylate" (registered trademark) BP-4EA, 0.5 g of a dispersant "BYK (registered trademark)"-LP21116 (manufactured by BYK-Chemie Co., Ltd.), 79.0 g of propylene glycol monomethyl ether acetate (hereinafter, "PGMEA"), and 16.0 g of silver fine particles having an average thickness of a surface carbon coating layer of 1 nm and a particle size of 40 nm (manufactured by Nisshin Engineering Inc.) were placed and 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.

(Production Example 5: Photosensitive Insulating Paste)
In a 100 mL clean bottle, 15.5 g of the acrylic resin having a carboxyl group obtained in Production Example 2, 5.2 g of "Light Acrylate (registered trademark)" BP-4EAL, 0.3 g of photopolymerization initiator N-1919, and 79.0 g of PGMEA were placed and mixed using a rotation-revolution vacuum mixer "Awatori Rentaro (registered trademark)" ARE-310 to obtain 100.0 g of photosensitive insulating paste. The obtained photosensitive insulating paste was applied onto a 4-inch silicone wafer, and the refractive index at a wavelength of 550 nm was measured at room temperature of 23° C. using a prism coupler (manufactured by Metricon, PC-2000), and was found to be 1.53.

Evaluation of each example and comparative example was carried out using the following methods.

(1) Line width W of laminated pattern
For the substrate after the formation of the laminate pattern obtained in each Example and Comparative Example, the laminate pattern formation portion was magnified and observed using an optical microscope, and the line width of the laminate pattern was measured at three randomly selected locations, and the average value was taken as the line width W of the laminate pattern.

(2) Internal diffuse reflectance An anti-reflection film with an adhesive layer MTAR-3 (manufactured by Mitate Imaging Co., Ltd.) was attached to the transparent protective layer-formed surface of the wiring substrate obtained in each Example and Comparative Example with a rubber roller. Furthermore, a black PET film with an adhesive, Kukiri Miel (manufactured by Tomoegawa Paper Co., Ltd.) was attached to the laminated pattern-free surface of the wiring substrate with a rubber roller to prepare the internal diffuse reflectance evaluation substrate 16 shown in FIG. 3. Using a spectrophotometer (CM-2500d) manufactured by Konica Minolta Sensing Co., Ltd., the diffuse reflectance SCE at wavelengths of 540, 550, 560, and 570 nm of the laminated pattern-formed portion of the internal diffuse reflectance evaluation substrate was measured, and the average value was taken as the average internal reflectance R1. Next, the diffuse reflectance SCE was measured at wavelengths of 540, 550, 560, and 570 nm of the non-layer pattern forming portion of the substrate for evaluating internal diffuse reflectance using a spectrophotometer (CM-2500d) manufactured by Konica Minolta Sensing Co., Ltd., and the average value was taken as the average internal reflectance R2.

(3) Difficulty in Visibility For the wiring substrates obtained in each of the Examples and Comparative Examples, a black sheet SuperBlackIR (manufactured by Systems Engineering Co., Ltd.) was placed on the opposite side of the opaque wiring electrode formation surface, and then light was projected onto the opaque wiring electrode formation surface using a floodlight. Ten people visually inspected the surface 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 opaque wiring electrode.

(4) Design visibility In each Example and Comparative Example, a light projector was used to project light onto the anti-reflection film-attached surface of the substrate for evaluating internal diffuse reflectance prepared in (2) Internal Diffuse Reflectance. Ten people visually inspected the substrate from a distance of 100 cm, and the design visibility was evaluated based on the number of people who could clearly see the boundary between the laminate pattern forming portion 10 and the laminate pattern non-forming portion 11.

(5) Photosensitivity In each Example and Comparative Example, the exposure device in <Formation of light-shielding layer> was replaced with a 365 nm LED lamp (manufactured by CCS Inc.), exposure was performed at each of the exposure amounts of 500 mJ/ ^cm2 , 800 mJ/ ^cm2 , 1500 mJ/ ^cm2 , and 3000 mJ/ ^cm2 , and photosensitivity was evaluated by defining the minimum exposure amount at which the exposed area was dissolved in a developer within 30 seconds as the required exposure amount. Note that when the exposed area did not dissolve within 30 seconds at 3000 mJ/ ^cm2 , it was evaluated as 3000<.

Example 1
<Opaque Wiring Electrode Forming Process>
On one side of alkali-free glass "AN Wizus (registered trademark)" (manufactured by AGC Co., Ltd., transmittance at wavelength 365 nm: 91%, transmittance at wavelength 550 nm: 92%), the photosensitive conductive paste (D-1) obtained in Production Example 4 was applied by spin coating so that the thickness after drying was 1 μm, and dried at 90 ° C. for 8 minutes. Through an exposure mask having a mesh-shaped laminated pattern forming portion 10 and a laminated pattern non-forming portion 11 shown in FIG. 4, an exposure device (PEM-6M; manufactured by Union Optical Co., Ltd.) was used to expose at an exposure dose of 150 mJ / cm ² (converted to a wavelength of 365 nm). Here, the mesh-shaped pattern is a negative pattern having a mesh pitch 14 of 400 μm and a mesh angle 15 of 58 °, and an opening width of 4 μm, a laminated pattern portion (mask opening) 12, and a non-laminated pattern portion (mask light shielding portion) 13. In addition, in FIG. 5, black and white are inverted for convenience of illustration. Thereafter, development was performed 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 area to dissolve, and then the result was rinsed with ultrapure water for 30 seconds, followed by heating and curing for 60 minutes in a box oven at 220° C. to form an opaque wiring electrode. The thickness of the opaque wiring electrode was measured using a stylus-type step gauge "Surfcom (registered trademark)" 1400 (manufactured by Tokyo Seimitsu Co., Ltd.) and found to be 0.5 μm.

<Laminated Pattern Forming Process>
(Preparation of positive-type photosensitive resin composition for forming light-shielding layer)
Into a 100 mL clean bottle, (a) 2.89 g of ferrovolac resin WR-104 (manufactured by DIC Corporation) as an alkali-soluble resin, (b) 0.49 g of the quinone diazide compound obtained in Production Example 1 as a quinone diazide compound, 0.22 g of carboxybenzotriazole "VERZONE (registered trademark)" C-BTA (manufactured by Daiwa Kasei Co., Ltd.), 0.01 g of a leveling agent "BYK (registered trademark)"-331 (manufactured by BYK-Chemie Co., Ltd.), and 44.45 g of PGMEA were placed and mixed using a rotation-revolution vacuum mixer "Awatori Rentaro (registered trademark)" ARE-310 (manufactured by Thinky Corporation) to obtain 48.07 g of a resin solution. The obtained 48.07 g of the resin solution, 1.21 g of carbon black MA100 (manufactured by Mitsubishi Chemical Corporation) and 0.72 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 volume % of 0.10 mmφ zirconia beads (manufactured by Toray Industries, Inc.) to obtain 50.0 g of a positive-type photosensitive resin composition 1 for forming a light-shielding layer.

(Formation of light-shielding layer)
The obtained positive photosensitive resin composition 1 for forming a light-shielding layer was spin-coated on the opaque wiring electrode surface formed in the <Opaque wiring electrode forming step> so that the film thickness after drying was 1.4 μm, and dried at 100 ° C. for 10 minutes. Thereafter, using the opaque wiring electrode as a mask, an exposure device (PEM-6M) was used to expose from the opposite side of the opaque wiring electrode forming surface under the condition of an exposure amount (converted to a wavelength of 365 nm) of 10,000 mJ / cm ² , and development was performed using a 2.38 mass% tetramethylammonium hydroxide aqueous solution as a developer until the transparent substrate of the exposed portion was exposed, forming a light-shielding layer pattern on the opaque wiring electrode, and forming a laminated pattern. Furthermore, it was heated in a box oven at 220 ° C. for 60 minutes.

<Transparent Protective Layer Forming Process>
On the substrate with the laminated pattern obtained in the <Laminated Pattern Forming Step>, the photosensitive insulating paste obtained in (Production Example 5) was spin-coated so that the film thickness after drying was 3.0 μm, and dried at 80 ° C. for 5 minutes. Using an exposure device (PEM-6M), the coated surface was exposed under the condition of an exposure amount (converted to a wavelength of 365 nm) of 100 mJ / cm ² , and development was performed for 60 seconds using a 0.1 mass % tetramethylammonium hydroxide aqueous solution as a developer. Furthermore, it was heated in a box oven at 220 ° C. for 60 minutes to obtain a wiring substrate on which a transparent protective layer was formed.

Example 2
A wiring substrate was obtained in the same manner as in Example 1, except that the mesh pitch and occupancy rate S of the exposure mask in the <Opaque wiring electrode formation process> and the composition in (Preparation of positive-type photosensitive resin composition for forming light-shielding layer) were changed as shown in Table 1.

(Examples 3 to 9)
A wiring substrate was obtained in the same manner as in (Example 2), except that the composition in (Preparation of positive-type photosensitive resin composition for forming light-shielding layer) and the exposure dose in (Formation of light-shielding layer) were changed as shown in Tables 1 and 2.

(Comparative Example 1)
A wiring substrate was obtained in the same manner as in Example 3, except that (formation of a light-shielding layer) was not carried out.

(Comparative Examples 2 to 6)
A wiring substrate was obtained in the same manner as in Example 2, except that the composition in (Preparation of positive-type photosensitive resin composition for forming light-shielding layer) and the exposure dose in (Formation of light-shielding layer) were changed as shown in Table 3.

Example 10
<Formation of Opaque Wiring Electrodes>
In the same manner as in Example 2, a substrate with an opaque wiring electrode was obtained.

<Laminated Pattern Forming Process>
(Preparation of positive-type photosensitive resin composition for forming light-shielding layer)
Into a 100 mL clean bottle, 0.77 g of phenol novolak resin WR-104 (manufactured by DIC Corporation), 2.33 g of the acrylic resin having a phenolic hydroxyl group and a carboxy group obtained in Production Example 2, 0.77 g of the quinone diazide compound obtained in Production Example 1, 0.19 g of carboxybenzotriazole "VERZONE (registered trademark)" C-BTA (manufactured by Daiwa Kasei Co., Ltd.), 0.01 g of leveling agent "BYK (registered trademark)"-331 (manufactured by BYK-Chemie Co., Ltd.), and 44.28 g of PGMEA were placed and mixed using a rotation-revolution vacuum mixer "Awatori Rentaro (registered trademark)" ARE-310 (manufactured by Thinky Corporation) to obtain 48.77 g of a resin solution. The obtained 48.77 g of resin solution, 0.79 g of titanium nitride particles, 0.32 g of purple organic pigment, 0.11 g of red organic pigment and 0.50 g of dispersant "BYK (registered trademark)"-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 volume % of 0.10 mmφ zirconia beads (manufactured by Toray Industries, Inc.) to obtain 50.0 g of positive photosensitive resin composition 2 for forming a light-shielding layer.

(Preparation of light-shielding layer transfer film)
A non-silicone release agent AL-5 (manufactured by Lintec Corporation) was applied to one side of a PET film "Lumirror (registered trademark)" FB40 (manufactured by Toray Industries, Inc.) (thickness: 16 μm), and the film was heat-treated and dried to form a release layer having a thickness of 100 nm on the surface of the substrate, thereby obtaining a release film. For the obtained release film, an acrylic adhesive tape "31B" manufactured by Nitto Denko Corporation was attached to the release layer-formed surface using a 2 kg roller, and the film was allowed to stand for 30 minutes. After that, the peel force was measured when the film was peeled off under the conditions of a peel angle of 180° and a peel speed of 0.3 m/min, and was found to be 1,480 mN/20 mm.

The positive-type photosensitive resin composition 2 for forming a light-shielding layer was applied to the release layer surface of the obtained release film using a coater so that the thickness after drying T1' was 1.4 μm, and the film was dried at 80° C. for 4 minutes to form a light-shielding layer, thereby obtaining a light-shielding layer transfer film.

(Formation of light-shielding layer)
The light-shielding layer transfer film obtained by <Preparation of light-shielding layer transfer film> was thermocompressed at 80°C and a speed of 0.1 m/min so that the light-shielding layer of the light-shielding layer transfer film obtained by <Preparation of light-shielding layer transfer film> was in contact with the opaque wiring electrode formed in the <Opaque wiring electrode formation process>, and the release film was peeled off. Thereafter, using the opaque wiring electrode as a mask, the film was exposed from the opposite side of the opaque wiring electrode formation surface under the condition of an exposure amount (converted to a wavelength of 365 nm) of 100 mJ/cm ² using an exposure device (PEM-6M), and development was performed using a 1.00 mass% sodium carbonate aqueous solution as a developer until the transparent substrate of the exposed portion was exposed, forming a light-shielding layer pattern on the opaque wiring electrode, and forming a laminated pattern. Further, the film was heated in a box oven at 220°C for 60 minutes.

<Formation of Transparent Protective Layer>
A transparent protective layer was formed in the same manner as in Example 1 to obtain a wiring substrate.

The main configurations and evaluation results of each example and comparative example are shown in Tables 1 to 4.

1: Transparent substrate 2: Opaque wiring electrode 3: Light-shielding layer 4: Wiring substrate 5: Laminated pattern 6: Transparent protective layer 7: Adhesive layer 8: Anti-reflection film 9: Black film 10: Laminated pattern forming portion 11: Laminated pattern non-forming portion 12: Laminated pattern portion (mask opening)
13: Non-laminated pattern portion (mask light shielding portion)
14: Mesh pitch 15: Mesh angle 16: Substrate for evaluating internal diffuse reflectance

Claims (11)

1. A wiring substrate having a laminated pattern of an opaque wiring electrode and a light-shielding layer containing a resin and a coloring component on a transparent substrate, in which the average internal diffuse reflectance R1 at wavelengths of 540 to 570 nm measured from the light-shielding layer side of the laminated pattern forming portion is 0.03 to 0.11%.
2. The wiring substrate according to claim 1, wherein the average internal diffuse reflectance R1 [%], the average internal diffuse reflectance R2 [%] at a wavelength of 540 to 570 nm of the laminate pattern non-forming portion, the line width W [μm] of the laminate pattern, and the ratio S of the laminate pattern area to the area of the laminate pattern forming portion (laminated pattern area/laminated pattern forming portion area) satisfy the relationship of the following formula (1).
   0.0≦((R1×W)−(R2×(1−S)))/S≦7.0 (1)
3. The wiring substrate according to claim 1 or 2, wherein the thickness T1 [μm] of the light-shielding layer is 0.2 to 2.0 μm.
4. A positive-type photosensitive resin composition for forming a light-shielding layer, comprising (a) an alkali-soluble resin, (b) a quinone diazide compound, (c) metal nitride particles, and (d) a purple organic pigment.
5. The positive photosensitive resin composition for forming a light-shielding layer according to claim 4, wherein the content of the (c) metal nitride particles is 2.0 to 6.0 volume %.
6. The positive-type photosensitive resin composition for forming a light-shielding layer according to claim 4 or 5, further comprising (e) a red organic pigment.
7. The positive photosensitive resin composition for forming a light-shielding layer according to claim 6, wherein the total content of (c) metal nitride particles, (d) purple organic pigment, and (e) red organic pigment is 5.0 to 15.0 volume %.
8. A light-shielding layer transfer film having a light-shielding layer formed from the positive-type photosensitive resin composition for forming a light-shielding layer according to claim 4 or 5 on a release film.
9. The light-shielding layer transfer film according to claim 8, wherein the thickness T1' [μm] of the light-shielding layer is 0.3 to 2.0.
10. A method for producing a wiring substrate according to claim 1 or 2, comprising the steps of:
    forming an opaque wiring electrode on a transparent substrate;
    A step of applying the positive photosensitive resin composition for forming a light-shielding layer according to claim 4 or 5 to the surface on which the opaque wiring electrode is formed; and
    a step of exposing the photosensitive resin composition coating film from the side opposite to the coating side using the opaque wiring electrode as a mask, and developing the photosensitive resin composition coating film to pattern the photosensitive resin composition coating film to form a laminated pattern of the opaque wiring electrode and the light-shielding layer;
    A method for producing a wiring substrate having the above structure.
11. A method for producing a wiring substrate according to claim 1 or 2, comprising the steps of:
    forming an opaque wiring electrode on a transparent substrate;
    A step of transferring the light-shielding layer of the light-shielding layer transfer film according to claim 8 onto the surface on which the opaque wiring electrode is formed; and
    a step of exposing the light-shielding layer from a surface opposite to a transfer surface using the opaque wiring electrode as a mask, and developing the light-shielding layer to pattern the light-shielding layer to form a laminated pattern of the opaque wiring electrode and the light-shielding layer;
    A method for producing a wiring substrate having the above structure.

Images