JP7721366B2 - Conductive substrate manufacturing method and conductive substrate - Google Patents

Description

The present invention relates to a method for manufacturing a conductive substrate used in touch sensors, touch panels, etc., and to the conductive substrate.

Currently, in various electronic devices, including portable information devices such as tablet computers and smartphones, there are touch panels that are used in combination with display devices such as liquid crystal display devices, and input operations into the electronic device are performed by touching or bringing a finger, stylus pen, etc. into contact with or close to the screen. The touch panel has a touch sensor that includes detection electrodes that detect touch and connection wiring that is electrically connected to the detection electrodes.
Here, in a touch sensor, low resistance of the electrodes is essential from the standpoint of touch response speed and power consumption, and a method of forming the electrodes with a mesh-like conductor pattern is known as a technique for achieving this low resistance.
The output wiring extracts electrical signals from the detection electrodes, runs around the detection electrodes, and is arranged up to a position where it connects to external wiring, for example, an FPC (flexible printed circuit). The external wiring and the output wiring are electrically connected at the connection portion, and are connected to an IC (integrated circuit) that controls the touch sensor through the external wiring. This enables the touch sensor to be driven. Note that a connection portion with the external wiring is required for the output wiring to input and output electrical signals to the detection electrodes.

The above-mentioned detection electrodes and extraction wiring are formed, for example, as disclosed in Patent Document 1, by exposing a photosensitive material having an emulsion layer containing a silver salt emulsion on a support, developing the material to form metallic silver, and then smoothing the silver.
Furthermore, the detection electrodes and the extraction wiring are formed collectively with high alignment accuracy by, for example, patterning using a single exposure mask.

JP 2007-129205 A

In recent years, mesh-like metal wires have become thinner in order to improve the image quality of touch panels. However, when the metal wires are thin, especially when the wire width is 3 μm or less, it is preferable to place a protective layer on the metal wire from the perspective of scratch resistance. However, at the connection points with the above-mentioned external wiring, there is a restriction that the protective layer cannot be made thick in order to reduce contact resistance. For this reason, in the case of thin metal wire parts that require scratch resistance, it is necessary to print a separate protective layer pattern after pattern formation, which increases the number of steps in the manufacturing process. Currently, simplifying the manufacturing process is an issue.

The object of the present invention is to provide a method for easily producing a conductive substrate having a silver wiring portion with excellent scratch resistance and a silver wiring portion with excellent connectivity to external terminals, and to provide the conductive substrate.

In order to achieve the above-mentioned object, one aspect of the present invention provides a method for manufacturing a conductive substrate, comprising the steps of: preparing a laminate having, in this order, a support, a first silver halide-containing layer containing silver halide, and a second silver halide-containing layer having a lower sensitivity than the first silver halide-containing layer; and exposing the laminate so that there are regions with different cumulative exposure amounts, and developing the laminate to form silver wiring.

The average grain size of the silver halide contained in the second silver halide-containing layer is preferably 250 nm or less.
The thickness of the second silver halide-containing layer is preferably 0.4 to 3.2 μm.
Preferably, the method for producing a conductive substrate according to any one of claims 1 to 3 includes a step of forming a crossover cut layer, a first silver halide-containing layer, and a second silver halide-containing layer in this order on both surfaces of a support, and a step of forming silver wiring includes a step of exposing and developing the laminate so that there are regions with different cumulative exposure amounts on both surfaces of the support.

One aspect of the present invention provides a conductive substrate comprising a support, a first silver wire portion and a second silver wire portion arranged on at least one of both surfaces of the support, and a resin layer arranged to cover the first silver wire portion and the second silver wire portion, wherein the thickness of the resin layer on the first silver wire portion is thicker than the thickness of the resin layer on the second silver wire portion, and the thickness of the first silver wire portion is thinner than the thickness of the second silver wire portion.
A first silver wire portion and a second silver wire portion are arranged on both sides of the support, respectively, and a resin layer is arranged to cover the first silver wire portion and the second silver wire portion, and it is preferable that the thickness of the resin layer on the first silver wire portion is thicker than the thickness of the resin layer on the second silver wire portion and the thickness of the first silver wire portion is thinner than the thickness of the second silver wire portion.
The thickness of the resin layer on the first silver wire portion is preferably 1.5 times or more the thickness of the resin layer on the second silver wire portion.
The thickness of the resin layer on the second silver wire portion is preferably 0.2 μm or less.
The sheet resistance of the first silver wire portion is preferably 50 Ω/sq or less.

The present invention provides a method for easily producing a conductive substrate having a silver wiring portion with excellent scratch resistance and a silver wiring portion with excellent connectivity to external terminals, as well as a conductive substrate.

1 is a schematic cross-sectional view showing a first example of an image display device having a conductive substrate according to an embodiment of the present invention. 1 is a schematic plan view showing an example in which a conductive substrate according to an embodiment of the present invention is used in a touch sensor. 1 is a schematic cross-sectional view illustrating an example of a conductive substrate according to an embodiment of the present invention. 1 is a schematic diagram showing an electrode configuration when a conductive substrate according to an embodiment of the present invention is used in a touch sensor. 1 is a schematic diagram showing an example of the shape of a mesh pattern of a conductive substrate according to an embodiment of the present invention. 1 is a schematic cross-sectional view showing one step of a method for producing a conductive substrate according to an embodiment of the present invention. 1 is a schematic cross-sectional view showing one step of a method for producing a conductive substrate according to an embodiment of the present invention.

Hereinafter, a method for manufacturing a conductive substrate and the conductive substrate of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
It should be noted that the drawings described below are illustrative for explaining the present invention, and the present invention is not limited to the drawings shown below.
In the following, the term "to" indicating a range of values includes the values written on both sides. For example, if ε is a value _εα to a value _εβ , the range of ε includes values _εα and _εα , and expressed in mathematical notation as _εα ≦ε≦ _εα .
Unless otherwise specified, angles such as "parallel" and "perpendicular" include a generally acceptable error range in the relevant technical field.

Unless otherwise specified, the term "transparent" means that the light transmittance in the visible light wavelength range of 380 to 780 nm is 40% or more, preferably 80% or more, and more preferably 90% or more.
The light transmittance is measured using "Plastics - Determination of total light transmittance and total light reflectance" as defined in JIS (Japanese Industrial Standards) K 7375:2008.
Unless otherwise specified, the term "insulation" refers to electrical insulation. An insulating substrate is a substrate that has electrical insulation properties and has electrical resistance according to the intended use. For example, when conductive lines are formed on both sides of an insulating substrate, the conductive lines formed on both sides are not electrically connected to each other.

(Conductive substrate)
Conductive substrates are used, for example, as touch sensors in touch panels. When a conductive substrate is used for a touch sensor, the configuration of the conductive substrate is not particularly limited as long as it functions as a touch sensor. For example, the conductive substrate has, on at least one surface of a support, a detection unit formed of a conductive layer and peripheral wiring, one end of which is electrically connected to the detection unit and the other end of which is connected to an external connection terminal. In the conductive substrate, a detection unit and peripheral wiring are provided on the front and back surfaces of the support, respectively. The peripheral wiring is also referred to as an extraction wiring. Below, an image display device using a conductive substrate will be described.

(Image display device)
FIG. 1 is a schematic cross-sectional view showing a first example of an image display device having a conductive substrate according to an embodiment of the present invention.
1 includes a touch panel 12 and an image display unit 14, with the touch panel 12 stacked on the display surface 14a side of the image display unit 14. The image display device 10 can detect a touch on an area of an image or the like displayed on the image display unit 14.
In the image display device 10, a touch panel 12 and an image display unit 14 are stacked. The touch panel 12 has a cover layer 16 provided on a protective layer 28 of a conductive substrate 18. For example, when viewed from the surface 16a side of the cover layer 16, the image display unit 14 is smaller than the conductive substrate 18.
In the image display device 10, it is preferable that the conductive substrate 18 and the cover layer 16, which are arranged on the display surface 14a side of the image display unit 14, are transparent so that the display object (not shown) displayed on the display surface 14a of the image display unit 14 can be seen.

The conductive substrate 18 of the image display device 10 shown in FIG. 1 has a first detection electrode layer 29A and a second detection electrode layer 29B provided on each of the two surfaces of the support 24. An undercoat layer 25a is provided on each of the front surface 24a and back surface 24b of the support 24. An antihalation layer 25b is provided on the undercoat layer 25a on the front surface 24a side. A second detection electrode layer 29B is provided on the antihalation layer 25b on the front surface 24a side, and a first detection electrode layer 29A is provided on the antihalation layer 25b on the back surface 24b side. The support 24 is electrically insulating, and the first detection electrode layer 29A and the second detection electrode layer 29B are electrically insulated by the support 24. In other words, the first detection electrode 30 and the second detection electrode 32 are electrically insulated by the support 24.

In the image display device 10, a resin layer 27 that covers the second detection electrode layer 29B is provided on the antihalation layer 25b on the surface 24a side of the support 24, and a protective layer 28 is provided on the resin layer 27. A cover layer 16 is provided on the protective layer 28.
A resin layer 27 is provided to cover the first detection electrode layer 29A. The image display unit 14 is connected with the display surface 14a facing the protective layer 28. The resin layer 27 and the protective layer 28 will be described later. The first thin metal wires constituting the first detection electrode layer 29A and the second thin metal wires constituting the second detection electrode layer 29B are both formed of silver wiring 35 shown in FIG. 3 to be described later.

If the cover layer 16 is made of glass, it is called a cover glass.
The surface 16a of the cover layer 16 is the touch surface and operation surface of the image display device 10. The image display device 10 is operated by inputting data using the surface 16a of the cover layer 16 as the operation surface. The touch surface is a surface that comes into contact with a finger, a stylus pen, or the like. The surface 16a of the cover layer 16 is the viewing surface for an object (not shown) displayed on the display surface 14a of the image display unit 14.
The controller 13 is provided on the rear surface 14b of the image display unit 14. The conductive substrate 18 and the controller 13 are electrically connected by a flexible wiring member such as a flexible circuit board 19. The flexible circuit board 19 is an external wiring.

A decorative layer (not shown) with a light-blocking function may be provided on the back surface 16b of the cover layer 16. The decorative layer is provided, for example, along the outer edge of the cover layer 16 when viewed from the front surface 16a side of the cover layer 16. The area where the decorative layer is provided is called the frame portion. The decorative layer prevents the components below the frame portion, such as the electrode terminals and peripheral wiring of the conductive substrate 18 described below, from being visible.

The controller 13 is configured using known devices used to detect contact of a finger or the like with the surface 16a of the cover layer 16, which serves as the touch surface. If the touch panel 12 is of the capacitance type, the controller 13 detects the position where the capacitance changes on the conductive substrate 18 due to contact of a finger or the like with the surface 16a of the cover layer 16, which serves as the touch surface. Capacitive touch panels include mutual capacitance touch panels and self-capacitance touch panels, but are not limited to these.

The cover layer 16 protects the conductive substrate 18. The configuration of the cover layer 16 is not particularly limited. The cover layer 16 is preferably transparent so that the display (not shown) displayed on the display surface 14a of the image display unit 14 can be seen. The cover layer 16 is made of, for example, a glass plate, chemically strengthened glass, alkali-free glass, or the like. The thickness of the cover layer 16 is preferably selected appropriately depending on the application. In addition to a glass plate, a plastic film, a plastic plate, or the like is used as the cover layer 16.
Examples of raw materials for the above-mentioned plastic films and plastic plates include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefin resins such as polyethylene (PE), polypropylene (PP), polystyrene, and EVA (polyethylene vinyl acetate copolymer); vinyl resins; and others, such as polycarbonate (PC) resin, polyamide resin, polyimide resin, (meth)acrylic resin, triacetyl cellulose (TAC), cycloolefin resin (COP), polyvinylidene fluoride (PVDF), polyarylate (PAR), polyethersulfone (PES), fluorene derivatives, and crystalline COP.
The (meth)acrylic resin is a general term including acrylic resin and methacrylic resin.
The cover layer 16 may also have a polarizing plate or a circular polarizing plate.
Since the surface 16a of the cover layer 16 serves as the touch surface as described above, a hard coat layer may be provided on the surface 16a as needed. The thickness of the cover layer 16 is, for example, 0.1 to 1.3 mm, and preferably 0.1 to 0.7 mm.

The image display unit 14 has a display surface 14a for displaying an image or other display object, and is, for example, a liquid crystal display device. The image display unit 14 is not limited to a liquid crystal display device, and may be an organic electroluminescence (EL) display device. In addition to the above, the image display unit 14 may also be a cathode ray tube (CRT) display device, a vacuum fluorescent display (VFD), a plasma display panel (PDP), a surface-emitting display (SED), a field emission display (FED), electronic paper, or the like.
The image display unit 14 is appropriately selected depending on the application, but in order to make the image display device 10 thin, it is preferable that it be in the form of a panel such as a liquid crystal display panel or an organic EL panel.
Note that, for example, an optically clear adhesive (OCA, Optical Clear Adhesive) or an optically clear resin (OCR, Optical Clear Resin) such as a UV (Ultra Violet) curable resin may be disposed between the protective layer 28 and the image display unit 14. In this case, the protective layer 28 may be partially hollow. Also, the touch panel 12 may be spaced apart from the display surface 14a of the image display unit 14 with a gap therebetween. This gap is also called an air gap.

(touch panel)
Fig. 2 is a schematic plan view showing an example in which the conductive substrate according to the embodiment of the present invention is used in a touch sensor. In Fig. 2, the same components as those in the image display device 10 shown in Fig. 1 are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.
The touch panel 12 will be described below with reference to FIGS.
The touch panel 12 shown in Fig. 1 includes a controller 13, a conductive substrate 18, and a cover layer 16. The conductive substrate 18 shown in Fig. 2 functions as a touch sensor.

The conductive substrate 18 has a first conductive layer 11A provided on the antihalation layer 25b. The first conductive layer 11A has a first detection electrode layer 29A having a plurality of first detection electrodes 30 and a plurality of first peripheral wirings 23a, one end of which is electrically connected to the first detection electrodes 30 of the first detection electrode layer 29A and the other end of which is provided with first external connection portions 26a. The first conductive layer 11A is covered with a resin layer 27.
The first detection electrode 30 is composed of silver wiring 35 (see FIG. 3). The silver wiring 35 constituting the first detection electrode 30 is also referred to as a first thin metal wire. The first thin metal wire is disposed on the antihalation layer 25b. The first conductive layer 11A is the first silver wire portion, and the first external connection portion 26a is the second silver wire portion.

The first external connection portion 26 a is electrically connected to the flexible circuit board 19 using, for example, an anisotropic conductive member 39 , and is connected to the controller 13 .
A second conductive layer 11B is provided on the antihalation layer 25b on the surface 24a side of the support 24. The second conductive layer 11B includes a second detection electrode layer 29B having a plurality of second detection electrodes 32 and a plurality of second peripheral wirings 23b, one end of which is electrically connected to the second detection electrodes 32 and the other end of which is provided with second external connection portions 26b. As with the first conductive layer 11A, the second external connection portions 26b are electrically connected to the flexible circuit board 19 using, for example, an anisotropic conductive member 39, and are connected to the controller 13. The anisotropic conductive member 39 is not particularly limited, and a known anisotropic conductive member can be used as appropriate, such as a thermosetting resin with conductive particles dispersed therein.

The second detection electrode 32 is composed of silver wiring 35 (see FIG. 3). The silver wiring 35 constituting the second detection electrode 32 is also referred to as a second thin metal wire. The second thin metal wire is disposed on the antihalation layer 25b. The second conductive layer 11B is the first silver wire portion, and the second external connection portion 26b is the second silver wire portion.
As described above, the first detection electrode 30 is referred to as the first thin metal wire, and the second detection electrode 32 is referred to as the second thin metal wire. The first thin metal wire and the second thin metal wire are collectively referred to as the silver wiring 35. Unless otherwise specified, the silver wiring 35 includes the first thin metal wire and the second thin metal wire.

(Conductive substrate)
The conductive substrate 18 will be described with reference to Fig. 2 and Fig. 3. Fig. 3 is a schematic cross-sectional view showing an example of a conductive substrate according to an embodiment of the present invention. In Fig. 3, the same components as those in the image display device 10 shown in Fig. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.
The conductive substrate 18 is, for example, a part that functions as a touch sensor of the touch panel 12, and has a detection section ₂₀ which is a detection area E1 where a user can perform input operations, and a peripheral wiring section 22 in a peripheral area _E2 located outside the detection area _E1 .
The detection unit 20 has, for example, a first detection electrode layer 29A and a second detection electrode layer 29B. The first detection electrode layer 29A and the second detection electrode layer 29B are arranged via a support 24. The first detection electrode layer 29A and the second detection electrode layer 29B are electrically insulated from each other by the support 24. The support 24 functions as an electrically insulating substrate.
As shown in FIG. 2, the first detection electrode layer 29A has a plurality of first detection electrodes 30 and a plurality of first dummy electrodes 31a arranged between adjacent first detection electrodes 30 and insulated from the first detection electrodes 30.

The multiple first detection electrodes 30 are strip-shaped electrodes extending parallel to each other in the X direction, and are provided on the surface of the antihalation layer 25b (see FIG. 1 ) at intervals in the Y direction, which is perpendicular to the X direction, and are electrically insulated from each other in the Y direction. Furthermore, the multiple first dummy electrodes 31a are arranged between the first detection electrodes 30 and are provided on the surface of the antihalation layer 25b (see FIG. 1 ) and are electrically insulated from the first detection electrodes 30. Each of the first detection electrodes 30 has a first electrode terminal 33 provided at at least one end in the X direction.
The second detection electrode layer 29B includes a plurality of second detection electrodes 32 and a plurality of second dummy electrodes 31b disposed between adjacent second detection electrodes 32 and insulated from the second detection electrodes 32. The second detection electrodes 32 are strip-shaped electrodes extending parallel to one another in the Y direction and are provided on the surface of the antihalation layer 25b (see FIG. 1) at intervals in the X direction and electrically insulated from one another in the X direction. The second dummy electrodes 31b are also disposed between the second detection electrodes 32 and are provided on the surface of the antihalation layer 25b (see FIG. 1) and electrically insulated from the second detection electrodes 32. Each second detection electrode 32 has a second electrode terminal 34 at one end in the Y direction.

The plurality of first detection electrodes 30 and the plurality of second detection electrodes 32 are provided orthogonal to each other, but are electrically insulated from each other by the support 24 as described above.
The first dummy electrodes 31 a and the second dummy electrodes 31 b in the first detection electrodes 30 and the second detection electrodes 32 are regions that are separated from the first detection electrodes 30 or the second detection electrodes 32 by disconnections and are not electrically connected. Therefore, as described above, the multiple first detection electrodes 30 are electrically insulated from each other in the Y direction, and the multiple second detection electrodes 32 are electrically insulated from each other in the X direction. As shown in FIG. 2 , the detection unit 20 is provided with six first detection electrodes 30 and five second detection electrodes 32, but the number is not particularly limited as long as there is more than one.
As described above, the first detection electrode layer 29A and the second detection electrode layer 29B are configured with the silver wiring 35 (see FIG. 3). When the first detection electrode 30 and the second detection electrode 32 are metal meshes having a mesh pattern with the silver wiring 35, the first dummy electrode 31a and the second dummy electrode 31b are also metal meshes having a mesh pattern with the silver wiring 35.
The electrode width of the first detection electrode 30 and the electrode width of the second detection electrode 32 are, for example, 1 to 5 mm, and the inter-electrode pitch is 3 to 6 mm. The electrode width of the first detection electrode 30 is the maximum length in the Y direction, and the electrode width of the second detection electrode 32 is the maximum length in the X direction.

The peripheral wiring section 22 is an area where peripheral wirings (first peripheral wirings 23 a, second peripheral wirings 23 b) are arranged, which are wirings for transmitting or transmitting touch drive signals and touch detection signals from the controller 13 to the first detection electrodes 30 and the second detection electrodes 32. The peripheral wiring section 22 has a plurality of first peripheral wirings 23 a and a plurality of second peripheral wirings 23 b. One end of the first peripheral wirings 23 a is electrically connected to the first detection electrodes 30 via first electrode terminals 33, and the other end is electrically connected to the first external connection portions 26 a. Furthermore, one end of the second peripheral wirings 23 b is electrically connected to the second detection electrodes 32 via second electrode terminals 34, and the other end is electrically connected to the second external connection portions 26 b.
The first electrode terminal 33 and the second electrode terminal 34 may have a solid film shape or a mesh shape as disclosed in JP 2013-127658 A. The preferred range of the width of the first electrode terminal 33 and the second electrode terminal 34 is 1/3 to 1.2 times the electrode width of the first detection electrode 30 and the second detection electrode 32, respectively.

The first detecting electrode 30, the first dummy electrode 31 a, the first electrode terminal 33, and the first peripheral wiring 23 a of the first conductive layer 11A are preferably integrally configured from the viewpoints of electrical resistance, resistance to disconnection, etc., and more preferably formed of the same metal material. In this case, the first conductive layer 11A is formed, for example, by pattern-exposing a silver halide-containing layer.
Similarly, the second detecting electrode 32, the second dummy electrode 31b, the second electrode terminal 34, and the second peripheral wiring 23b of the second conductive layer 11B are preferably integrally configured from the viewpoints of electrical resistance, resistance to disconnection, etc., and more preferably formed of the same metal material. In this case, the second conductive layer 11B is formed, for example, by pattern-exposing a silver halide-containing layer, as described below.

Figure 3 is a diagram of the conductive substrate 18, partially omitted to show the support 24, undercoat layer 25a, antihalation layer 25b, first silver wire portion 37 of the first detection electrode 30 of the first detection electrode layer 29A, and resin layer 27, illustrating the structure of the surface 24a of the support 24. As explained using Figure 2, conductive layers and the like are present on both sides of the support 24, but these are not shown in Figure 3. The silver wires 35 shown in Figure 3 are first thin metal wires. Multiple silver wires 35 form the first silver wire portion 37. As described above, the first silver wire portion 37 forms the first conductive layer 11A and the second conductive layer 11B. The second silver wire portion 38 is the first external connection portion 26a. As described above, the second silver wire portion 38 also serves as the second external connection portion 26b.

3 shows the first silver wire portion 37, the second silver wire portion 38, etc. on only one side, but the conductive substrate 18 has a support 24, and the first silver wire portion 37 and the second silver wire portion 38 arranged on both sides of the support 24. Also, a resin layer 27 is arranged to cover the first silver wire portion and the second silver wire portion. The thickness d1 of the resin layer 27 on the first silver wire portion 37 is thicker than the thickness _d2 of the resin layer on the second silver wire portion _38. Furthermore, the thickness _H1 of the first silver wire portion 37 is thinner than the thickness _H2 of the second silver wire portion 38.
The thickness _H2 of the resin layer 27 on the second silver wire portion 38 is preferably 0.2 μm or less. If the thickness _H2 of the resin layer 27 is 0.2 μm or less, the contact resistance can be sufficiently reduced.
The conductive substrate 18 has an undercoat layer 25a provided on the surface 24a of a support 24, and an antihalation layer 25b provided on the undercoat layer 25a.
An undercoat layer 25a is provided on the back surface 24b of the support 24, and an antihalation layer 25b is provided on the undercoat layer 25a. In FIG. 3, the surface of the support 24 refers to the antihalation layer 25b.

The thickness _d1 of the resin layer 27 on the first silver wire portion 37 is preferably 1.5 times or more the thickness _d2 of the resin layer 27 on the second silver wire portion 38. If the thickness _d1 of the resin layer 27 on the first silver wire portion 37 is 1.5 times or more the thickness _d2 of the resin layer 27 on the second silver wire portion 38, scratch resistance is increased and the first silver wire portion 37 is sufficiently protected. Note that it is more preferable for the thickness _d1 of the resin layer 27 on the first silver wire portion 37 to be 3 to 5 times the thickness _d2 of the resin layer 27 on the second silver wire portion 38, as this will result in even higher scratch resistance.
As described above, the thickness _d1 of the resin layer 27 on the first silver wire portion 37 is different from the thickness _d2 of the resin layer 27 on the second silver wire portion 38, but the average thickness of the resin layer 27 between the silver wirings 35 of the first silver wire portion 37 is approximately the same as the average thickness of the resin layer 27 between the second silver wire portions 38.
The average thickness of the resin layer 27 between the silver wires 35 of the first silver wire portion 37 is the average thickness of the resin layer 27 at the intermediate positions between the silver wires 35 .
The average thickness of the resin layer 27 between the second silver wire portions 38 is the average thickness of the resin layer 27 at the intermediate positions between the first external connection portions 26a.
The average thickness of the resin layer 27 between the silver wirings 35 of the first silver wire portion 37 is determined by measuring the length corresponding to the midpoint between the silver wirings 35 at 10 points using a cross-sectional image of the cut cross section obtained using a scanning electron microscope (SEM), and calculating the average value of the measured values at 10 points.
The average thickness of the resin layer 27 between the second silver wire portions 38 is determined by measuring the length corresponding to the midpoint between the silver wirings 35 at 10 points using a cross-sectional image of the cut cross section obtained using a scanning electron microscope (SEM), and calculating the average value of the measured values at 10 points.

The thickness H ₁ of the first silver wire portion, the thickness H ₂ of the second silver wire portion, the thickness d ₁ of the resin layer 27 on the first silver wire portion 37, and the thickness d ₂ of the resin layer on the second silver wire portion 38 are measured using cross-sectional images of the cut surface obtained by cutting the conductive substrate 18 and using a scanning electron microscope (SEM). In the cross-sectional image, lengths corresponding to the thickness H ₁ of the first silver wire portion, the thickness H ₂ of the second silver wire portion, the thickness d ₁ of the resin layer 27 on the first silver wire portion 37, and the thickness d ₂ of the resin layer on the second silver wire portion 38 are measured at 10 locations, and the average values of the measurements at the 10 locations are calculated. The thickness H ₁ of the first silver wire portion, the thickness H ₂ of the second silver wire portion, the thickness d ₁ of the resin layer 27 on the first silver wire portion 37, and the thickness d ₂ of the resin layer on the second silver wire portion 38 are each the average values of the measurements at the 10 locations.
Although the conductive substrate 18 has been described as having the first silver wire portion 37 and the second silver wire portion 38 provided on both sides of the support body 24, the present invention is not limited to this. The conductive substrate 18 may have the first silver wire portion 37 and the second silver wire portion 38 provided on one of the two sides of the support body 24. Furthermore, a touch sensor can be formed by stacking substrates each having the first silver wire portion 37 and the second silver wire portion 38 provided on one side of the support body.
As will be described later, for example, the silver wiring 35 of the first silver wire portion 37 forms a mesh pattern (see FIG. 4).

For example, to narrow the frame around the display to improve design, the conductive substrate 18 is folded in the folding region Bf of the peripheral wiring portion 22 shown in FIG. 2 with the first external connection portion 26a and the second external connection portion 26b facing outward. A flexible circuit board 19 electrically connected to the first external connection portion 26a and the second external connection portion 26b is disposed on the back surface 14b side of the image display unit 14, opposite the display surface 14a side.

The thickness _H1 of the first silver wire portion 37 is preferably 0.01 to 200 μm, more preferably 30 μm or less, even more preferably 20 μm or less, particularly preferably 0.01 to 9 μm, and most preferably 0.05 to 5 μm. Within the above range, a low-resistance electrode with excellent durability can be formed relatively easily.
The width Wc of the silver wiring 35 of the first silver wire portion 37 is not particularly limited, but the upper limit is preferably 30 μm or less, more preferably 15 μm or less, even more preferably 10 μm or less, particularly preferably 9 μm or less, and most preferably 7 μm or less, and the lower limit is preferably 0.5 μm or more, more preferably 1.0 μm or more. Within the above range, a low-resistance electrode can be formed relatively easily.
When the silver wiring 35 of the first silver wire portion 37 is used as a peripheral wiring, the width Wc of the silver wiring 35 is preferably 500 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less. Within the above range, a low-resistance touch panel electrode can be formed relatively easily.
From the viewpoint of a balance between thinning and conductive properties, the thickness _H2 of the second silver wire portion 38 is preferably 200 μm or less, more preferably 30 μm or less, even more preferably 10 μm or less, particularly preferably 0.3 to 5 μm, and most preferably 0.5 to 5 μm.

The thickness _H1 of the first silver wire portion 37, the thickness _H2 of the second silver wire portion 38, and the width Wc of the silver wiring 35 are measured using a cross-sectional image of the cut surface obtained by cutting the conductive substrate 18 and using a scanning electron microscope (SEM). In the cross-sectional image, for the image area corresponding to the first silver wire portion 37, lengths corresponding to the thickness _H1 of the first silver wire portion 37 and the width Wc of the silver wiring 35 are measured at 10 locations, and the average values of the measurements at the 10 locations are calculated. The thickness H1 of the first silver wire portion ₃₇ and the width Wc of the silver wiring 35 are each the average values of the measurements at the 10 locations. Furthermore, for the image area corresponding to the thickness of the second silver wire portion 38, the length corresponding to the thickness _H2 of the second silver wire portion 38 is measured at 10 locations, and the average values of the measurements at the 10 locations are calculated.

Here, for touch panels installed on tablets or notebook PCs (personal computers), which are larger in size than smartphones, a lower fine wire resistance is required as the electrical resistance of the first silver wire portion 37 in order to detect touch operations caused by contact or proximity of a finger or stylus pen, etc.
To prevent delays in operations with a finger or a stylus pen, the sheet resistance of the first silver wire portion is preferably 50 Ω/sq or less, and more preferably 25 Ω/sq or less.
The sheet resistance is measured by calculating from the voltage E (unit: volts V) applied to the conductive substrate when a current is passed through the conductive substrate, the current I (unit: amperes A), the average inter-electrode distance L (unit: millimeters mm), and the average sheet width W (unit: millimeters mm) using the following formula: The average inter-electrode distance L is the average distance between two connection points on the conductive substrate where a voltage is applied, and the average sheet width is the average length in the direction perpendicular to the direction in which the average inter-electrode distance L is calculated.
Sheet resistance = (E/I) x (W/L)
Furthermore, when actually measuring, the voltage E _total includes not only the voltage E applied to the conductive substrate but also the voltage drop Ec resulting from the contact resistance Rc. Therefore, the effect can be calculated using the following formula by measuring the contact resistance in advance.
E=E _total -Rc×I
Alternatively, the sheet resistance can be simply determined by measuring local sheet resistances by surface resistivity measurement such as JIS (Japanese Industrial Standards) K 7194 (1994) and averaging the measured values.

Furthermore, in order to reduce the reflectance of the first silver wire portion 37, the surface of the first silver wire portion 37 may be subjected to a blackening treatment, such as sulfurization or oxidation, to provide a blackening layer (not shown). The blackening layer reduces the reflectance of the first silver wire portion 37. The blackening layer may be made of, for example, copper nitride, copper oxide, copper oxynitride, molybdenum oxide, AgO, Pd, carbon, or other nitrides or oxides. The blackening layer is disposed on the visible side of the thin metal wires, i.e., the surface of the first silver wire portion 37 opposite the undercoat layer 25a. Note that a configuration without a blackening layer is also possible.
An adhesive layer (not shown) may be provided at the interface between the first silver wire portion 37 and the undercoat layer 25a. By providing the adhesive layer, the adhesiveness between the first silver wire portion 37 and the undercoat layer 25a is improved, and the first silver wire portion 37 and the second silver wire portion 38 can be stably disposed on the undercoat layer 25a.

As will be described later, the thickness ta of the resin layer 27 depends on the thickness of the silver halide layer for forming the first silver wire portion 37 and the second silver wire portion 38. The thickness ta of the resin layer 27 is approximately 2.0 to 5.0 μm. If the thickness ta of the resin layer 27 is 2.0 to 5.0 μm, it is possible to achieve both scratch resistance and contact resistance of the second silver wire portion.
The thickness ta of the resin layer 27 is measured by cutting the conductive substrate 18 and using a cross-sectional image of the cut surface taken with a scanning electron microscope (SEM). In the cross-sectional image, a length corresponding to the thickness of the resin layer 27 is measured at 10 locations in the image area corresponding to the resin layer 27, and the average value of the measured values at the 10 locations is calculated. The thickness ta of the resin layer 27 is the average value of the measured values at the 10 locations.

Each part of the conductive substrate and the touch panel will be described below.
<Support>
The support 24 supports the first silver wire portion 37 and the second silver wire portion 38. The support 24 also supports the first conductive layer 11A, the first external connection portion 26a, the second conductive layer 11B, and the second external connection portion 26b. If the first conductive layer 11A and the first external connection portion 26a are arranged on one surface of the support and the second conductive layer 11B and the second external connection portion 26b are arranged on the other surface, they are electrically insulated from each other.
The support preferably has flexibility. Here, having flexibility means that it can be bent, specifically, that it does not crack even when bent with a curvature radius of 1 mm.
The type of support is not limited as long as it can support the first silver wire portion 37 and the second silver wire portion 38 and is flexible, but a transparent support is preferable, and a plastic sheet is particularly preferable.

Specific examples of materials constituting the support include, for example, PET (polyethylene terephthalate) (258°C), polycycloolefin (134°C), polycarbonate (250°C), (meth)acrylic resin (128°C), PEN (polyethylene naphthalate) (269°C), PE (polyethylene) (135°C), PP (polypropylene) (163°C), polystyrene (230°C), polyvinyl chloride (180°C), polyvinylidene chloride (212°C), polyPVDF (vinylidene fluoride) (177°C), PAR (polyarylate) (250°C), PES (polyethersulfone) (225°C), polymeric acrylic resin, fluorene derivative (140°C), crystalline COP (165°C), or TAC (triacetylcellulose) (290°C), and other plastic films having a melting point of about 290°C or less are preferred, with (meth)acrylic resin, PET, polycycloolefin, or polycarbonate being more preferred. The values in parentheses above are melting points or glass transition temperatures.
The total light transmittance of the support is preferably from 85 to 100%.
The thickness of the support is not particularly limited, but from the viewpoint of application to a touch panel, it can usually be selected arbitrarily in the range of 25 to 500 μm. Note that, when the support also functions as a touch surface in addition to its function as a support, it can also be designed to have a thickness exceeding 500 μm.
One preferred embodiment of the support is a support that has been treated by at least one treatment selected from the group consisting of atmospheric pressure plasma treatment, corona discharge treatment, and ultraviolet irradiation treatment. By performing the above-mentioned treatment, hydrophilic groups such as OH groups are introduced into the surface of the treated support, thereby further improving the adhesion of the conductive wire.

<Undercoat layer>
The undercoat layer contains a polymer and further improves the adhesion between the first silver wire portion 37 and the second silver wire portion 38, or the first conductive layer 11A, the first external connection portion 26a, the second conductive layer 11B, and the second external connection portion 26b.
The method for forming the undercoat layer is not particularly limited, and examples thereof include a method in which a composition for forming an undercoat layer containing a polymer is applied to a substrate and, if necessary, a heat treatment is performed. The composition for forming an undercoat layer may contain a solvent, if necessary. The type of solvent is not particularly limited, and known solvents are exemplified. Furthermore, a latex containing fine polymer particles may be used as the composition for forming an undercoat layer containing a polymer.
The thickness of the undercoat layer is not particularly limited, but is preferably 0.02 to 0.3 μm, and more preferably 0.03 to 0.2 μm, in order to provide better adhesion between the first silver wire portion 37 and the second silver wire portion 38, or between the first conductive layer 11A, the first external connection portion 26 a, the second conductive layer 11B, and the second external connection portion 26 b.

<Anti-halation layer>
The antihalation layer is, for example, a silver halide-free layer. The silver halide-free layer contains gelatin and a specific polymer, which will be described later, but does not contain silver halide. Note that the antihalation layer may not be included.

<Crossover cut layer>
A crossover cut layer may be provided below the first silver halide-containing layer described below.
The crossover cut layer is a specific layer used when a support has silver halide-containing layers on both sides. It is used to solve the problem of image degradation caused by light passing through the support from one side affecting the silver halide-containing layer on the other side. A dye corresponding to the photosensitive wavelength range is added to the crossover cut layer. Any dye can be used as long as it does not leave harmful absorption after development.
It is particularly preferred to add the dye in the form of a solid fine particle dispersion. Methods of adding the dye in the form of a solid fine particle dispersion are described in JP-A Nos. 2-264936, 3-210553, 3-210554, 3-238447, 4-14038, 4-14039, 4-125635, 4-338747, and 6-27589. Usable dyes include, for example, dyes of formulas (I) to (VII) described in JP-A No. 4-211542, and exemplary compounds I-1 to I-37, II-1 to II-6, III-1 to III-36, IV-1 to IV-16, V-1 to V-6, VI-1 to VI-13, and VII-1 to VII-5. Dyes of formula (1) described in JP-A-8-73767, and example compounds 1 to 6. Dyes of formulas (VIII) to (XII), and example compounds VIII-1 to VIII-5, IX-1 to IX-10, X-1 to X-21, XI-1 to XI-6, and XII-1 to XII-7 described in JP-A-8-87091.

<Silver wiring>
As described above, the silver wiring comprises the first silver wire portion 37 (see FIG. 3) and the second silver wire portion 38 (see FIG. 3).
A method using silver halide can be used to manufacture the first silver wire portion 37 and the second silver wire portion 38. More specifically, the method described in paragraphs 0056 to 0114 of JP-A 2014-209332 can be mentioned. The method using silver halide will be described in detail later.

The silver wiring preferably contains a large amount of carbon atoms, preferably a large amount of polymer, in the metal portion. By including a polymer, durability, bendability, and handling suitability can be improved. As the polymer, gelatin and polymers other than gelatin described below are preferred, and water-soluble polymers such as gelatin are more preferred.
The content of the polymer in the silver wiring is preferably 200 mg/m ² or more per area of the silver wiring, more preferably 400 mg/m ² or more, and even more preferably 500 mg/m ² or more. If the polymer is, for example, gelatin, the content of the polymer can be quantified by the BCA method (bicinchoninic acid method) in an area of about 4 cm x 4 cm only where the solid metal film is formed. If the polymer is other than gelatin, the content can be quantified by selecting an appropriate known method such as an extraction method.
Furthermore, it is preferable that the pattern portion located in the peripheral wiring portion (hereinafter simply referred to as the "peripheral pattern") contains a large amount of polymer relative to the detection portion made of silver wiring, and that in the region within the peripheral pattern where the metal atom number ratio is 50% or more, the ratio of the atomic number ratio of carbon atoms to metal atoms is 0.2 or more.
The atomic number ratio can be calculated by analyzing the atomic composition of the peripheral pattern from the surface of the silver wiring opposite the support in the depth direction using Ar sputtering (2 kV, Ar ions, 2 mm × 2 mm) and XPS (X-ray source: Al Kα, Quantera SXM manufactured by ULVAC-PHI, Inc.).
The substrate side of the position where the metal atom number ratio is 50% or more is defined as the interior, and the atomic number ratio of carbon atoms to metal atoms (carbon atoms/metal atoms) in the interior region can be determined. For example, in the case of a silver wiring or pattern with a width of 100 μm or more, the above-mentioned sputtering and XPS (X-ray Photoelectron Spectroscopy) method can be used to determine the atomic composition. For smaller patterns, such as those with a width of 100 μm or less, a cross section of the pattern can be extracted, and the center of the pattern can be used as a representative value to determine the atomic composition within the pattern using SEM-EDX (Scanning Electron Microscope-Energy Dispersive X-ray Spectrometry).

[Mesh pattern]
As described above, the first detection electrode 30 and the second detection electrode 32 are configured by the silver wiring 35. The first detection electrode 30 and the second detection electrode 32 configure a mesh pattern in which a plurality of silver wirings 35 intersect, as shown in FIG.
In the first detection electrode 30 and the second detection electrode 32, the mesh pattern formed by the silver wiring 35 preferably has an aperture ratio of 85% or more, more preferably 90% or more, and even more preferably 95% or more, from the viewpoint of visible light transmittance. The aperture ratio corresponds to the percentage of the transparent portion excluding the silver wiring in the region where the conductive layer is provided, i.e., the percentage of the openings in the entire region where the conductive layer is provided.
The first peripheral wiring 23a and the second peripheral wiring 23b may also have the same configuration as the first detection electrode 30 and the second detection electrode 32, and may be made of silver wiring 35. The first peripheral wiring 23a and the second peripheral wiring 23b may have a mesh pattern in which a plurality of silver wirings 35 intersect.

When the first detection electrode 30 and the second detection electrode 32, and the first peripheral wiring 23a and the second peripheral wiring 23b are configured to have a mesh pattern, the pattern of the mesh pattern is not particularly limited, and is preferably a geometric figure that combines a triangle such as an equilateral triangle, an isosceles triangle, or a right-angled triangle, a quadrangle such as a square, a rectangle, a rhombus, a parallelogram, or a trapezoid, a (regular) n-gon such as a (regular) hexagon or a (regular) octagon, a circle, an ellipse, a star, or the like.
The term "mesh" in the mesh pattern refers to a shape including a plurality of openings 36 formed by intersecting silver wiring 35, as shown in FIG. 5 . The openings 36 are open regions surrounded by the silver wiring 35. In FIG. 5 , the openings 36 are rhombic, but other shapes are also possible. For example, they may be polygonal (e.g., triangular, rectangular, hexagonal, and random polygonal). Furthermore, the shape of one side may be straight, curved, or arc-shaped. In the case of arc-shaped openings, for example, two opposing sides may be arc-shaped outwardly convex, and the other two opposing sides may be arc-shaped inwardly convex. Furthermore, each side may be wavy, consisting of a series of outwardly convex and inwardly convex arcs. Of course, each side may be a sine curve. The mesh pattern is not particularly limited and may be a random pattern or a regular pattern, or may be a regular mesh pattern in which multiple congruent shapes are repeatedly arranged.

The mesh pattern is preferably a regular mesh pattern having identical diamond lattices. The length of one side of the diamond, i.e., the length W of one side of the opening 36, is preferably 800 μm or less, more preferably 600 μm or less, and even more preferably 400 μm or less, and the lower limit is preferably 5 μm or more, more preferably 30 μm or more, and even more preferably 80 μm or more. When the length W of one side of the opening is within the above-mentioned range, it is possible to maintain good transparency, and when the conductive substrate 18 (see FIG. 1) is attached to the display surface 14a (see FIG. 1) of the image display unit 14 (see FIG. 1), the display can be viewed without any discomfort.
The mesh pattern of the silver wiring can be observed and measured using an optical microscope (Keyence Corporation Digital Microscope VHX-7000).

<Resin layer>
The resin layer 27 is a layer that covers the first thin metal wires, and is transparent and electrically insulating.
The resin layer 27 is not particularly limited as long as it can maintain electrical insulation without causing electrical conduction between the first silver wire portion 37 and the second silver wire portion 38, which are originally electrically insulated, when the conductive substrate 18 is in use. The resin layer 27 contains, for example, a polymer different from the gelatin used to produce the silver wires.

(Method for manufacturing conductive substrate)
A method for manufacturing the conductive substrate 18 will now be described.
FIG. 6 is a schematic cross-sectional view showing one step of the method for manufacturing a conductive substrate according to an embodiment of the present invention, and FIG. 7 is a schematic cross-sectional view showing one step of the method for manufacturing a conductive substrate according to an embodiment of the present invention.
The method includes a first step of forming an undercoat layer 25 a on a support 24, a second step of forming an antihalation layer 25 b on the undercoat layer 25 a, and a third step of forming a first silver line portion 37 and a second silver line portion 38 on the antihalation layer 25 b.
For example, a PET substrate is used as the support.
In the first step, as shown in FIG. 6, a polymer latex is applied to each of the front surface 24a and the back surface 24b of the support 24 to form an undercoat layer 25a.
The method for forming the undercoat layer 25 a is not particularly limited, and examples thereof include a method of applying a composition for forming an undercoat layer and, if necessary, performing a curing treatment. Examples of the application method include conventionally known coating methods such as spin coating, gravure coating, reverse coating, die coating, blade coating, roll coating, air knife coating, screen coating, bar coating, and curtain coating.
After application, a curing treatment may be carried out as necessary, such as a photocuring treatment or a heat treatment.

In the second step, as shown in Figure 6, a silver halide-free layer-forming composition, which is a mixture of polymer latex and gelatin, is applied onto each undercoat layer 25a to form an antihalation layer 25b.

In the third step, a silver halide-containing layer containing silver halide is formed on the antihalation layer 25b, and exposure and development are performed to form first silver wire portions 37 (see FIG. 3) and second silver wire portions 38 (see FIG. 3). In order to form a mesh pattern (see FIG. 4) using the silver wiring 35 that constitutes the first silver wire portions 37, the third step preferably includes a step of forming the first thin metal wires into a mesh pattern (see FIG. 4). The mesh pattern is formed by the exposure pattern.
6, a first silver halide-containing layer 40 containing silver halide is formed on each antihalation layer 25b. Next, a second silver halide-containing layer 42 containing silver halide and having a lower sensitivity than the first silver halide-containing layer 40 is formed on the first silver halide-containing layer 40. In this manner, a laminate 43 having the support 24, the first silver halide-containing layer 40, and the second silver halide-containing layer 42 in this order is produced.
Next, a protective layer-forming composition, for example, a mixture of polymer latex and gelatin, is applied onto each second silver halide-containing layer 42 to form a protective layer 28 .

7 , an exposure mask 44 is placed on the surface 28a of the protective layer 28 in the laminate 43, which is on the front surface 24a side of the support 24. In addition, an exposure mask 44 is placed on the surface 28b of the protective layer 28 on the back surface 24b side of the support 24.
Next, the exposure mask 44 is irradiated with parallel light Lv from the glass substrate 45 side, and exposed using the parallel light Lv. In the exposure process, the laminate 43 is exposed so that there are regions with different cumulative exposure amounts. Although the exposure mask 44 is placed at a distance in FIG. 7 , in reality, the exposure mask 44 is placed in close contact with the support 24 and exposed.
In addition, when forming the first silver line portion 37 etc. on both sides of the support 24, in the exposure process, the laminate 43 may be exposed to light through the exposure mask 44 on both sides of the support 24 at the same time, or each side of the support 24 may be exposed through the exposure mask 44.
As will be described later, the exposure mask 44 is, for example, a mask having two or more types of openings with different transmittances.

Specifically, the exposure mask 44 includes a glass substrate 45 and a light-shielding layer 46. The light-shielding layer 46 has openings 47, 47a that transmit light in a specific pattern. Of the openings 47, 47a in the light-shielding layer 46, a halftone filter layer 48 is provided in the opening 47a that forms the first silver line portion. The halftone filter layer 48 is not provided in the opening 47 that forms the second silver line portion. The halftone filter layer 48 reduces the amount of light that passes through, and for example, a light transmittance adjustment filter is used. The halftone filter layer 48 has, for example, a transmittance of 70% or less for the light used for exposure. With this configuration, the openings 47 and the openings 47a have different transmittances and different exposure amounts. In the exposure mask 44, the openings 47 have a higher transmittance and a higher exposure amount than the openings 47a. In this way, the exposure mask 44 can change the exposure amount to expose the silver halide-containing layer to regions with different cumulative exposure amounts. The exposure mask 44 is also called a halftone mask.
In the exposure mask 44, the light-shielding rate of the light-shielding layer 46, the sensitivity of the first silver halide-containing layer 40, and the sensitivity of the second silver halide-containing layer 42 are adjusted in transmittance so that the first silver halide-containing layer 40 and the second silver halide-containing layer 42 are developed in the areas where the halftone filter layer 48 is not provided, and the first silver halide-containing layer 40 is developed but the second silver halide-containing layer 42 is not developed in the areas where the halftone filter layer 48 is provided.
The light transmittance of the halftone filter layer 48 is measured using the "Plastics - Determination of total light transmittance and total light reflectance" defined in the above-mentioned JIS (Japanese Industrial Standards) K 7375:2008.
The halftone filter layer 48 is preferably a filter layer that changes the amount of light by 15% or more, and more preferably a filter layer that changes the amount of light by 30% or more.
It should be noted that a laser beam may also be used as the light source when exposing using the exposure mask 44 .
Furthermore, although the exposure mask 44 is used for exposure, the present invention is not limited to this, and direct writing exposure using laser light may be used without using the exposure mask 44. In this case, the amount of laser light is adjusted so that there are regions with different cumulative exposure amounts.

As described above, the exposure mask 44 is a mask having, for example, two types of openings 47, 47a with different transmittances. The transmittance of the openings 47, 47a can be adjusted, for example, by using light transmittance adjusting filters with different transmittances of light used for exposure.
The sensitivity of the first silver halide-containing layer 40 and the sensitivity of the second silver halide-containing layer 42 are evaluation indexes based on the conversion rate of silver halide to silver when irradiated with light. Low sensitivity means that the conversion rate of silver halide to silver when irradiated with light is low.

Exposure using the above-described exposure mask 44 separates the first silver halide-containing layer 40 into a developed portion and the first silver halide-containing layer 40 and the second silver halide-containing layer 42 into a developed portion. In the region exposed to light passing through the opening 47a, the first silver halide-containing layer 40 is developed, but the second silver halide-containing layer 42 is not developed. As a result, a thin first silver line portion 37 is formed. On the other hand, in the region exposed to light passing through the opening 47, the first silver halide-containing layer 40 and the second silver halide-containing layer 42 are developed. As a result, a thick second silver line portion 38 is formed. As shown in FIG. 3 , the first silver line portion 37 and the second silver line portion 38 have different thicknesses.
Furthermore, since the exposure mask 44 can expose the formation area of the first silver wire portion 37 and the formation area of the second silver wire portion 38 with a single mask, the first silver wire portion 37 and the second silver wire portion 38 can be formed with better alignment accuracy than when multiple masks are used.
6 and 7 show a pattern for forming the first silver wire portion 37 and the second silver wire portion 38 for the sake of convenience, but the exposure mask 44 is not limited to this. The exposure mask 44 may also be configured to have a pattern for exposing the wiring pattern of the conductive substrate 18 shown in FIG. 2, for example.

The method of exposure and development using silver halide will be explained in more detail below.
Step A: A step of forming a silver halide-containing photosensitive layer containing silver halide, gelatin, and a specific polymer on a support. Step B: A step of exposing the silver halide-containing photosensitive layer and then developing it to form a fine-line silver-containing layer containing metallic silver, gelatin, and a polymer different from gelatin. Step C: A step of subjecting the silver-containing layer obtained in Step B to a heat treatment. Step D: A step of removing the gelatin from the silver-containing layer obtained in Step C to form the above-mentioned silver wiring. The procedure of each step is described in detail below.

[Process A]
In step A, a silver halide-containing photosensitive layer (hereinafter also referred to as "photosensitive layer") containing silver halide, gelatin, and a specific polymer is formed on a support. This step produces a laminate having, in this order, a first silver halide-containing layer containing silver halide and a second silver halide-containing layer containing silver halide and having a lower sensitivity than the first silver halide-containing layer.
As described above, the first silver halide-containing layer and the second silver halide-containing layer formed by this process have different sensitivities, but the sensitivities can be controlled by adjusting the components contained in each silver halide-containing layer. In particular, as described below, the sensitivity of the silver halide-containing layer can be easily adjusted by adjusting the amount of a compound containing a metal element belonging to Group VIIB added.
First, the materials used in step A will be described in detail, and then the procedure for step A will be described in detail.

(silver halide)
The halogen atom contained in the silver halide may be any of chlorine atom, bromine atom, iodine atom, and fluorine atom, or a combination thereof.For example, silver halide mainly composed of silver chloride, silver bromide, or silver iodide is preferred, and silver halide mainly composed of silver chloride or silver bromide is more preferred.In addition, silver chlorobromide, silver iodochlorobromide, or silver iodobromide is also preferably used.
Here, for example, "silver halide mainly composed of silver chloride" refers to a silver halide in which the molar fraction of chloride ions in the total halide ions in the silver halide composition is 50% or more. This silver halide mainly composed of silver chloride may contain bromide ions and/or iodide ions in addition to chloride ions.

The silver halide is usually in the form of solid particles, and the average particle size of the silver halide is preferably from 10 to 1,000 nm, more preferably from 10 to 200 nm, and even more preferably from 50 to 150 nm, in terms of equivalent spherical diameter.
The silver halide contained in the second silver halide-containing layer preferably has an average particle size of 250 nm or less, more preferably 150 nm or less, from the viewpoint of suppressing scattering of incident light into the first silver halide-containing layer.
The shape of the silver halide grains is not particularly limited, and examples thereof include spherical, cubic, tabular (hexagonal tabular, triangular tabular, quadrangular tabular, etc.), octahedral, and tetradecahedral shapes.
The "equivalent sphere diameter" is the diameter of a spherical particle having the same volume. The "equivalent sphere diameter" used as the average particle diameter of the silver halide is an average value, which is obtained by measuring the equivalent sphere diameters of 100 objects and calculating the arithmetic mean thereof.

(gelatin)
The type of gelatin is not particularly limited, and examples thereof include lime-processed gelatin and acid-processed gelatin. In addition, gelatin hydrolysates, enzymatic decomposition products, and gelatin modified with amino groups and/or carboxyl groups (phthalated gelatin and acetylated gelatin) may also be used.

(Specified polymer)
The photosensitive layer contains a polymer (specific polymer) different from gelatin. By including this specific polymer in the photosensitive layer, the strength of the silver-containing layer and silver wiring formed from the photosensitive layer is improved.
The type, specific examples, shape, and other characteristics of the specific polymer are as described above.

Among these, the specific polymer is preferably a polymer (copolymer) represented by the following general formula (1).
General formula (1): -(A)x-(B)y-(C)z-(D)w-
In the general formula (1), A, B, C, and D represent repeating units represented by the following general formulae (A) to (D), respectively.

^R1 represents a methyl group or a halogen atom, and is preferably a methyl group, a chlorine atom, or a bromine atom. p represents an integer of 0 to 2, preferably 0 or 1, and more preferably 0.
^R2 represents a methyl group or an ethyl group, with a methyl group being preferred.
^R3 represents a hydrogen atom or a methyl group, preferably a hydrogen atom. L represents a divalent linking group, preferably a group represented by the following general formula (2).
General formula (2): -(CO-X ¹ )r-X ² -
In general formula (2), X ¹ represents an oxygen atom or NR ³⁰ -. Here, R ³⁰ represents a hydrogen atom, an alkyl group, an aryl group, or an acyl group, each of which may have a substituent (e.g., a halogen atom, a nitro group, or a hydroxyl group). R ³⁰ is preferably a hydrogen atom, an alkyl group having 1 to 10 carbon atoms (e.g., a methyl group, an ethyl group, an n-butyl group, or an n-octyl group), or an acyl group (e.g., an acetyl group or a benzoyl group). ^{X 1} is preferably an oxygen atom or NH-.
^X2 represents an alkylene group, an arylene group, an alkylenearylene group, an arylenealkylene group, or an alkylenearylenealkylene group, and these groups may have -O-, -S-, -CO-, -COO-, _-NH- , -SO2-, -N( ^R31 )-, or -N( ^R31 ) _SO2- , etc. inserted therein. ^R31 represents a linear or branched alkyl group having 1 to 6 carbon atoms. ^X2 is preferably a dimethylene group, a trimethylene group, a tetramethylene group, an o _- phenylene group, an m-phenylene group, a p _- phenylene group, _{-CH2CH2OCOCH2CH2-} , _{or -CH2CH2OCO} ( _{C6H4 ) -} .
r represents 0 or 1.
q represents 0 or 1, with 0 being preferred.

R ⁴ represents an alkyl group, an alkenyl group, or an alkynyl group, and is preferably an alkyl group having 5 to 50 carbon atoms, more preferably an alkyl group having 5 to 30 carbon atoms, and even more preferably an alkyl group having 5 to 20 carbon atoms.
^R5 represents a hydrogen atom, a methyl group, an ethyl group, a halogen atom, or _—CH2COOR6 ^, preferably a hydrogen atom, a methyl group, a halogen atom, or _—CH2COOR6 , more preferably a hydrogen atom, a methyl _group , or ^—CH2COOR6 , ^and even more preferably a hydrogen atom.
^R6 represents a hydrogen atom or an alkyl group having 1 to 80 carbon atoms, and may be the same as or different from ^R4 . ^R6 preferably has 1 to 70 carbon atoms, and more preferably has 1 to 60 carbon atoms.

In the general formula (1), x, y, z, and w represent the molar ratio of each repeating unit.
x is 3 to 60 mol %, preferably 3 to 50 mol %, and more preferably 3 to 40 mol %.
y is 30 to 96 mol %, preferably 35 to 95 mol %, and more preferably 40 to 90 mol %.
z is 0.5 to 25 mol %, preferably 0.5 to 20 mol %, and more preferably 1 to 20 mol %.
w is 0.5 to 40 mol %, preferably 0.5 to 30 mol %.
In the general formula (1), it is preferable that x is 3 to 40 mol %, y is 40 to 90 mol %, z is 0.5 to 20 mol %, and w is 0.5 to 10 mol %.

The polymer represented by general formula (1) is preferably a polymer represented by the following general formula (2):

In general formula (2), x, y, z, and w are as defined above.

The polymer represented by general formula (1) may contain repeating units other than the repeating units represented by the above general formulae (A) to (D).
Examples of monomers for forming other repeating units include acrylic acid esters, methacrylic acid esters, vinyl esters, olefins, crotonates, itaconic acid diesters, maleic acid diesters, fumaric acid diesters, acrylamides, unsaturated carboxylic acids, allyl compounds, vinyl ethers, vinyl ketones, heterocyclic vinyl compounds, glycidyl esters, and unsaturated nitriles. These monomers are also described in paragraphs 0010 to 0022 of Japanese Patent No. 3754745. From the viewpoint of hydrophobicity, acrylic acid esters or methacrylic acid esters are preferred, and hydroxyalkyl methacrylates or hydroxyalkyl acrylates are more preferred.
The polymer represented by general formula (1) preferably contains a repeating unit represented by general formula (E).

In the above formula, L _E represents an alkylene group, preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 2 to 6 carbon atoms, and even more preferably an alkylene group having 2 to 4 carbon atoms.

A polymer represented by general formula (1) is particularly preferably a polymer represented by the following general formula (3):

In the above formula, a1, b1, c1, d1, and e1 represent the molar ratio of each repeating unit, where a1 represents 3 to 60 (mol%), b1 represents 30 to 95 (mol%), c1 represents 0.5 to 25 (mol%), d1 represents 0.5 to 40 (mol%), and e1 represents 1 to 10 (mol%).
The preferred range of a1 is the same as the preferred range of x, the preferred range of b1 is the same as the preferred range of y, the preferred range of c1 is the same as the preferred range of z, and the preferred range of d1 is the same as the preferred range of w.
e1 is 1 to 10 mol %, preferably 2 to 9 mol %, and more preferably 2 to 8 mol %.

The specific polymer can be synthesized by referring to, for example, Japanese Patent No. 3305459 and Japanese Patent No. 3754745.
The weight average molecular weight of the specific polymer is not particularly limited, but is preferably from 1,000 to 1,000,000, more preferably from 2,000 to 750,000, and even more preferably from 3,000 to 500,000.

(Compounds containing metal elements belonging to Group VIIB)
The photosensitive layer may contain a compound containing a metal element belonging to Group VIIB (hereinafter, also simply referred to as a "specific compound"). The sensitivity can be adjusted by adjusting the content of the specific compound in the photosensitive layer.
The specific compound is preferably a rhodium compound, an iridium compound, a ruthenium compound, an iron compound, or an osmium compound. These compounds may have various ligands, and examples of the ligands include cyanide ions, halogen ions, thiocyanate ions, nitrosyl ions, water, hydroxide ions, ammonia, amines (methylamine, ethylenediamine, etc.), heterocyclic compounds (imidazole, thiazole, 5-methylthiazole, mercaptoimidazole, etc.), urea, and thiourea.
The rhodium compound may be a water-soluble rhodium compound, such as a rhodium(III) halide compound, for example, a hexachlororhodium(III) complex salt, a pentachloroacollodium complex salt, a tetrachlorodiacollodium complex salt, a hexabromorhodium(III) complex salt, a hexaaminerhodium(III) complex salt, or a trisalarhodium(III) complex salt.

The photosensitive layer may contain materials other than the above-mentioned materials, if necessary.
Other materials include antistatic agents, nucleation accelerators, spectral sensitizing dyes, surfactants, antifoggants, hardeners, anti-black spot agents, redox compounds, monomethine compounds, and dihydroxybenzenes, as described in paragraphs 0220 to 0241 of JP-A-2009-004348.
Other materials include viscosity modifiers (for example, thickening polysaccharides, celluloses, water-soluble polymers, etc.), film-forming aids (for example, glycol derivatives, diol compounds such as 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, etc.), preservatives, plasticizers, slipping agents, fillers made of organic, inorganic, or organic-inorganic composite materials (for example, PMMA (Poly Methyl Methacrylate), polystyrene, colloidal silica, zirconia, cellulose nanofibers, CNT (carbon nanotubes), etc.), and ultraviolet absorbers.
The antistatic agent is preferred because it can prevent adhesion of foreign matter due to charging of the silver halide-containing photosensitive material or failure due to unintended photosensitivity caused by discharge light emission. The surfactant is preferred because it can control the coatability of the photosensitive layer, adhesion to the support, and dispersibility of the silver halide, binder, and other components contained therein.
The photosensitive layer may also contain a crosslinking agent or curing agent described in paragraphs 0146 to 0158 of JP-A 2009-004348, a dye described in paragraphs 0160 to 0170, or a water-soluble binder described in paragraphs 0214 to 0217. The photosensitive layer may also contain a metal stabilizer described in paragraphs 0079 to 0081 of WO 2020/195622, or a specific compound described in paragraphs 0109 to 0118. Furthermore, the photosensitive layer may also contain physical development nuclei.

The photosensitive layer may also contain a crosslinking agent used to crosslink the specific polymers. The inclusion of a crosslinking agent promotes crosslinking between the specific polymers, maintaining the connection between the metallic silver particles in the silver wiring even when the gelatin is decomposed and removed. Materials other than gelatin and the specific polymer may also be contained in the silver halide-free layer and/or protective layer, which will be described later.

(Procedure of Step A)
The method for forming the photosensitive layer containing the above components in step A is not particularly limited, but from the viewpoint of productivity, a method in which a photosensitive layer-forming composition containing silver halide, gelatin, and a specific polymer is brought into contact with a support, and a first silver halide-containing layer and a second silver halide-containing layer are formed on the support is preferred.
The form of the photosensitive layer-forming composition used in this method will be described in detail below, and then the steps will be described in detail.

(Materials contained in the composition for forming the photosensitive layer)
The photosensitive layer-forming composition contains the above-mentioned silver halide, gelatin, and specific polymer. If necessary, the specific polymer may be contained in the photosensitive layer-forming composition in the form of particles.
The photosensitive layer-forming composition may contain a solvent, if necessary.
Examples of the solvent include water, organic solvents (for example, alcohols, ketones, amides, sulfoxides, esters, and ethers), ionic liquids, and mixed solvents thereof.

The method for contacting the photosensitive layer-forming composition with the support is not particularly limited, and examples thereof include a method of applying the photosensitive layer-forming composition onto the support, and a method of immersing the support in the photosensitive layer-forming composition.
After the above treatment, a drying treatment may be carried out as necessary.

(Silver halide-containing photosensitive layer)
The photosensitive layer formed by the above procedure contains silver halide, gelatin, and a specific polymer.
The content of silver halide in the photosensitive layer is not particularly limited, but is preferably 3.0 to 20.0 g/m ² in terms of silver, and more preferably 5.0 to 15.0 g/m ² in terms of silver, in terms of obtaining better effects of the present invention.
The term "silver equivalent" means that the silver halide is converted into the mass of silver produced by reduction.
The content of the specific polymer in the photosensitive layer is not particularly limited, but is preferably 0.04 to 2.0 g/m ² , and more preferably 0.08 to 0.40 g/m ² , in terms of achieving better effects of the present invention.
The sensitivity of the second silver halide-containing layer is lower than that of the first silver halide-containing layer, and this can be achieved by adjusting the emulsion, for example. More specifically, as described above, the sensitivity can be adjusted by adjusting the content of a specific compound. Another method for adjusting the sensitivity is to add a light-absorbing material (e.g., a solid dye) fixed to each layer, and the amount of light-absorbing material added is increased relative to the layer that reduces the sensitivity. Therefore, by increasing the amount of light-absorbing material added to the second silver halide-containing layer, the sensitivity can be lowered compared to the first silver halide-containing layer.

[Process B]
In step B, the photosensitive layer is exposed to light and then developed to form a fine line-shaped silver-containing layer containing metallic silver, gelatin, and a specific polymer.

As described above, the photosensitive layer is subjected to an exposure process using an exposure mask 44 (see FIG. 7) having a halftone filter layer 48 (see FIG. 7), whereby a latent image is formed by exposure with an integrated exposure amount according to the openings 47, 47a (see FIG. 7).
The exposure may be carried out in a pattern. For example, to obtain a mesh pattern consisting of silver wiring as described below, exposure may be carried out through a mask having a mesh-like opening pattern.
The type of light used for exposure is not particularly limited as long as it can form a latent image on the silver halide, and examples thereof include visible light, ultraviolet light, and X-rays.

When exposing through an exposure mask having an aperture pattern, the amount of exposure can be adjusted by reducing the exposure dose only in specific locations within the mask aperture pattern and adjusting the cumulative exposure dose before exposure, thereby adjusting the amount of latent image formation. Adjusting the amount of latent image formation makes it possible to adjust the amount of metal formed in subsequent operations and its thickness (height). There are no particular limitations on the means for reducing the exposure dose only in specific locations, but examples include adjusting the exposure dose from the light source irradiating the specific area. Examples include reducing the output of only the lamp or LED (light emitting diode) above the relevant area to lower the exposure dose, or installing a neutral density filter above the specific area. Another method for reducing the exposure dose only in specific areas is to use a half-tone mask, in which a semi-transparent film is applied to specific areas of the mask aperture pattern. From the perspective of productivity, using a half-tone mask is preferable.

By subjecting the exposed photosensitive layer to a development process, metallic silver is precipitated in the exposed areas (areas where a latent image is formed).
The method of development is not particularly limited, and examples thereof include known methods used for silver halide photographic films, photographic paper, films for printing plate making, and emulsion masks for photomasks.
In the development process, a developer is usually used. The type of developer is not particularly limited, and examples thereof include a PQ (phenidone hydroquinone) developer, an MQ (metol hydroquinone) developer, and an MAA (metol ascorbic acid) developer.

This step may further include a fixing treatment for the purpose of removing and stabilizing the silver halide in the unexposed areas.
Fixing treatment is carried out simultaneously with and/or after development. The method of fixing treatment is not particularly limited, and examples thereof include methods used for silver halide photographic film, photographic paper, film for printing plate making, and emulsion masks for photomasks.
In the fixing process, a fixing solution is usually used. The type of fixing solution is not particularly limited, and examples thereof include the fixing solutions described on page 321 of "Chemistry of Photography" (by Sasai, published by Shashin Kogyo Shuppansha Co., Ltd.).

By carrying out the above treatment, a thin line-shaped silver-containing layer containing metallic silver, gelatin, and a specific polymer is formed.
An example of a method for adjusting the line width of the silver-containing layer is to adjust the opening width of an exposure mask used during exposure.
In addition, when an exposure mask is used during exposure, the width of the silver-containing layer to be formed can be adjusted by adjusting the exposure dose. For example, when the opening width of the exposure mask is narrower than the target width of the silver-containing layer, the width of the region where the latent image is formed can be adjusted by increasing the exposure dose more than usual.

In addition, one way to adjust the atomic ratio of carbon atoms to metal atoms in the region within the peripheral pattern where the metal atom ratio is 50% or more is to adjust the size of the peripheral pattern relative to the detection electrode. If the peripheral pattern is large relative to the detection electrode, it becomes difficult to remove gelatin from the peripheral pattern in step D, which will be described later. As a result, a peripheral pattern with a high carbon atom ratio can be formed.

[Process C]
Step C is a step of subjecting the silver-containing layer obtained in Step B to a heat treatment. By carrying out this step, fusion between specific polymers in the silver-containing layer progresses, and the strength of the silver-containing layer is improved.

The heat treatment method is not particularly limited, and examples include a method in which the silver-containing layer is brought into contact with superheated steam, and a method in which the silver-containing layer is heated using a temperature control device (e.g., a heater), with the method in which the silver-containing layer is brought into contact with superheated steam being preferred.

The superheated steam may be superheated steam or a mixture of superheated steam and other gases.
The contact time between the superheated vapor and the silver-containing layer is not particularly limited, but is preferably 10 to 70 seconds.
The amount of superheated steam supplied is preferably 500 to 600 g/m ³ , and the temperature of the superheated steam is preferably 100 to 160°C (preferably 100 to 120°C) at 1 atmosphere.

When heating the silver-containing layer using a temperature control device, the heating conditions are preferably 100 to 200°C (preferably 100 to 150°C) for 1 to 240 minutes (preferably 60 to 150 minutes).

[Process D]
Step D is a step of forming the silver wiring by removing gelatin from the silver-containing layer obtained in step C. By carrying out this step, gelatin is removed from the silver-containing layer, and the silver wiring having voids formed therein is formed. A plating solution, which will be described later, penetrates into these voids, forming metal plating.
When removing gelatin, all of the gelatin in the silver-containing layer may be removed, or a portion of the gelatin may be removed so as to remain. In particular, it is preferable to carry out step D so that a portion of the gelatin remains, in terms of achieving a more excellent effect of the present invention.

The method for removing gelatin is not particularly limited, and examples include a method using a protease (hereinafter also referred to as "Method 1") and a method using an oxidizing agent to decompose and remove gelatin (hereinafter also referred to as "Method 2").

The proteolytic enzyme used in Method 1 includes known plant or animal enzymes that can hydrolyze proteins such as gelatin.
Examples of proteolytic enzymes include pepsin, rennin, trypsin, chymotrypsin, cathepsin, papain, ficin, thrombin, renin, collagenase, bromelain, and bacterial proteases, with trypsin, papain, ficin, and bacterial proteases being preferred.
The procedure for Method 1 may be any method that brings the silver-containing layer into contact with the protease, such as bringing the silver-containing layer into contact with a treatment liquid containing a protease (hereinafter also referred to as "enzyme liquid"). Examples of contacting methods include immersing the silver-containing layer in the enzyme liquid and applying the enzyme liquid onto the silver-containing layer.
The content of the protease in the enzyme solution is not particularly limited, and is preferably 0.05 to 20% by mass, more preferably 0.5 to 10% by mass, based on the total amount of the enzyme solution, in that the degree of decomposition and removal of gelatin can be easily controlled.
The enzyme solution usually contains water in addition to the protease.
The enzyme solution may contain other additives (for example, pH (hydrogen ion index) buffers, antibacterial compounds, humectants, and preservatives) as needed.
The pH of the enzyme solution is selected so as to maximize the activity of the enzyme, and generally, a pH of 5 to 9 is preferred.
The temperature of the enzyme solution is preferably a temperature at which the activity of the enzyme is enhanced, specifically 20 to 45°C.

If necessary, after the treatment with the enzyme solution, the resulting silver-containing layer may be washed with warm water.
The washing method is not particularly limited, and a method of bringing the silver-containing layer into contact with warm water is preferred. Examples include a method of immersing the silver-containing layer in warm water and a method of applying warm water onto the silver-containing layer.
The optimum temperature of the hot water is selected depending on the type of protease used, and from the viewpoint of productivity, a temperature of 20 to 80°C is preferred, and a temperature of 40 to 60°C is more preferred.
The contact time (washing time) between the hot water and the silver-containing layer is not particularly limited, but from the viewpoint of productivity, it is preferably from 1 to 600 seconds, more preferably from 10 to 180 seconds.

The oxidizing agent used in Method 2 may be any oxidizing agent capable of decomposing gelatin, and is preferably an oxidizing agent having a standard electrode potential of +1.5 V or higher. The standard electrode potential here refers to the standard electrode potential (25° C., E0) of the oxidizing agent in an aqueous solution relative to a standard hydrogen electrode.
Examples of the oxidizing agent include persulfuric acid, percarbonate, perphosphoric acid, hypoperchloric acid, peracetic acid, metachloroperbenzoic acid, hydrogen peroxide, perchloric acid, periodic acid, potassium permanganate, ammonium persulfate, ozone, hypochlorous acid, or a salt thereof. From the viewpoints of productivity and economy, however, hydrogen peroxide (standard electrode potential: 1.76 V), hypochlorous acid, or a salt thereof is preferred, and sodium hypochlorite is more preferred.

The procedure for Method 2 may be any method that brings the silver-containing layer into contact with the oxidizing agent, such as a method of bringing the silver-containing layer into contact with a treatment liquid containing an oxidizing agent (hereinafter also referred to as an "oxidizing agent liquid"). Examples of the contact method include a method of immersing the silver-containing layer in the oxidizing agent liquid and a method of applying the oxidizing agent liquid onto the silver-containing layer.
The type of solvent contained in the oxidizing agent liquid is not particularly limited, and examples thereof include water and organic solvents.

[Process E]
Step 1 may include, before step A, step E of forming a silver halide-free layer containing gelatin and a specific polymer on the support. By carrying out this step, a silver halide-free layer is formed between the support and the silver halide-containing photosensitive layer. This silver halide-free layer plays the role of a so-called antihalation layer and also contributes to improving adhesion between the silver wiring and the support.
The silver halide-free layer contains the above-mentioned gelatin and specific polymer, while the silver halide-free layer does not contain any silver halide.
The ratio of the mass of the specific polymer to the mass of gelatin in the silver halide-free layer (mass of specific polymer/mass of gelatin) is not particularly limited, but is preferably from 0.1 to 5.0, more preferably from 1.0 to 3.0.
The content of the specific polymer in the silver halide-free layer is not particularly limited, but is often 0.03 g/m or ^more , and is preferably 1.0 g/m or ^more in terms of better adhesion of silver wiring. There is no particular upper limit, but it is often 1.63 g/m or ^less .

The method for forming the silver halide-free layer is not particularly limited, and examples thereof include a method in which a layer-forming composition containing gelatin and a specific polymer is applied to a support, and if necessary, a heat treatment is carried out.
The layer-forming composition may contain a solvent, if necessary. Examples of the solvent include the solvents used in the photosensitive layer-forming composition described above.
The thickness of the silver halide-free layer is not particularly limited, and is often 0.05 μm or more. In order to obtain better adhesion of the silver wiring, the thickness is preferably more than 1.0 μm, and more preferably 1.5 μm or more. The upper limit is not particularly limited, but it is preferably less than 3.0 μm. The thicknesses of the first silver halide-containing layer and the second silver halide-containing layer are appropriately determined depending on the thicknesses of the first silver wire portion and the second silver wire portion.

[Process F]
Step 1 may include step F, which is performed after step A and before step B (exposure and development step), to form a protective layer containing gelatin and a specific polymer on the silver halide-containing photosensitive layer. By providing the protective layer, the scratch resistance and mechanical properties of the photosensitive layer can be improved.
The ratio of the mass of the specific polymer to the mass of gelatin in the protective layer (mass of specific polymer/mass of gelatin) is not particularly limited, but is preferably more than 0 and not more than 2.0, more preferably more than 0 and not more than 1.0.
The content of the specific polymer in the protective layer is not particularly limited, but is preferably more than 0 g/m ² and not more than 0.3 g/m ² , and more preferably 0.005 to 0.1 g/m ² .

The method for forming the protective layer is not particularly limited, and examples thereof include a method in which a composition for forming a protective layer containing gelatin and a specific polymer is applied onto a silver halide-containing photosensitive layer, and if necessary, a heat treatment is carried out.
The composition for forming a protective layer may contain a solvent, if necessary. Examples of the type of solvent include the solvents used in the composition for forming a photosensitive layer described above.
The thickness of the protective layer is not particularly limited, but is preferably 0.03 to 0.3 μm, and more preferably 0.075 to 0.20 μm.

The above-mentioned steps E, A, and F may be carried out simultaneously by simultaneous multi-layer coating.

[Step 2]
Step 2 is a step of contacting the silver wiring with a solution containing an organic acid. By carrying out this step, the organic acid adheres to the surface of the silver wiring, which suppresses plating deposition on the surface of the silver wiring during the plating treatment in Step 3 described below, and makes it easier for the plating solution to penetrate into the silver wiring. As a result, metal (metal plating) is more likely to deposit within the silver wiring, achieving the desired effect.
Below, first, the solution used in this step will be described in detail, and then the procedure of step 2 will be described in detail.

(Solution containing organic acid)
The type of organic acid contained in the solution containing an organic acid (hereinafter also simply referred to as "first solution") is not particularly limited, and may be any acid containing a carbon atom, such as carboxylic acid (an organic compound having a carboxy group), sulfonic acid (an organic compound having a sulfonic acid group), and phosphonic acid (an organic compound having a phosphonic acid group). Of these, carboxylic acid is preferred because it provides better effects of the present invention.

There are no particular restrictions on the molecular weight of the organic acid (e.g., carboxylic acid), but in terms of achieving better effects of the present invention, a molecular weight of 60 to 400 is preferred, and 90 to 300 is even more preferred.

The carboxylic acid may be a monovalent carboxylic acid or a divalent or higher (polyvalent) carboxylic acid, and polyvalent carboxylic acids are preferred in terms of achieving better effects of the present invention. As the divalent or higher carboxylic acid, divalent to heptavalent carboxylic acids are preferred, and divalent to tetravalent carboxylic acids are more preferred.
The above valence indicates the number of carboxy groups contained, and a monovalent carboxylic acid is a compound having one carboxy group.

The carboxylic acid may have a polar group other than the carboxy group (e.g., a hydroxy group, an amino group, a carbonyl group, or an ether group).

Examples of carboxylic acids include monocarboxylic acids such as acetic acid, lactic acid, and hydroxybutyric acid; dicarboxylic acids such as oxalic acid, malonic acid, tartaric acid, L-aspartic acid, DL-malic acid, oxaloacetic acid, succinic acid, glutamic acid, 2-oxoglutaric acid, glutaric acid, adipic acid, and pimelic acid; tricarboxylic acids such as citric acid, 1,2,3-propanetricarboxylic acid, and 1,3,5-pentatricarboxylic acid; tetracarboxylic acids such as 1,2,3,4-butanetetracarboxylic acid, ethylenediaminetetraacetic acid, and ethylene glycol bis(β-aminoethyl ether)-N,N,N,N-tetraacetic acid; and pentacarboxylic acids such as diethylenetriaminepentaacetic acid.

The first solution contains a solvent. The type of solvent is not particularly limited, and examples include water, organic solvents (e.g., alcohols, ketones, amides, sulfoxides, esters, and ethers), ionic liquids, and mixed solvents thereof. Of these, water is preferred.

The first solution may contain components other than the organic acid and solvent.
The other component may be a quaternary ammonium salt contained in the second solution, which will be described later. The form of the quaternary ammonium salt will be described in detail later.

The content of organic acid in the first solution is not particularly limited, but in terms of achieving better effects of the present invention, a content of 0.2 to 5% by mass, and more preferably 0.5 to 3% by mass, relative to the total mass of the first solution is preferred.

The pH value of the first solution is not particularly limited, but is preferably 1.5 to 6.0, more preferably 2.0 to 4.0 at a temperature of 25° C., in terms of providing a better effect of the present invention.
The pH can be measured using a pH meter with a pH electrode.

When the first solution contains a quaternary ammonium salt, the content of the quaternary ammonium salt in the first solution is not particularly limited, but in terms of better effects of the present invention, the content is preferably 10 ⁻⁶ to 10 ⁻¹ mass %, and more preferably 10 ⁻⁵ to 10 ⁻³ mass %, relative to the total mass of the first solution.

(Procedure of Step 2)
The method for contacting the silver wiring with the first solution is not particularly limited, and examples thereof include a method of immersing a support having silver wiring in the first solution and a method of applying the first solution onto the silver wiring.
The contact time between the silver wiring and the first solution is not particularly limited, but is preferably 5 to 180 seconds, more preferably 20 to 120 seconds, from the viewpoint of achieving better effects of the present invention and productivity.
The temperature of the first solution when it comes into contact with the silver wiring is not particularly limited, but is preferably 30 to 100°C, more preferably 65 to 95°C, in terms of achieving better effects of the present invention.

After contacting the silver wiring with the first solution, the silver wiring may be washed with a solvent (e.g., water) if necessary.

[Step 3]
Step 3 is a step of forming a silver wiring by plating the silver wiring. By carrying out this step, a silver wiring is formed in which a metal (plating metal) is filled in the silver wiring. In particular, since the silver wiring obtained by carrying out the above-mentioned steps A to D has spaces formed by removing the gelatin, the metal (plating metal) fills these spaces.
When step 2 is performed immediately before step 3, the silver wiring obtained in step 2 is plated. When step 5 is performed between step 2 and step 3, as described below, the silver wiring obtained in step 5 is plated.

The type of plating treatment is not particularly limited, but examples include electroless plating (chemical reduction plating or displacement plating) and electrolytic plating, with electroless plating being preferred. As the electroless plating, a known electroless plating technique is used.
Examples of plating treatments include silver plating treatment, copper plating treatment, nickel plating treatment, and cobalt plating treatment. Silver plating treatment or copper plating treatment is preferred, with silver plating treatment being more preferred, since the electrical resistance of the silver wiring is lower.

The components contained in the plating solution used in the plating process are not particularly limited, but typically contain, in addition to a solvent (e.g., water), 1. metal ions for plating, 2. a reducing agent, 3. an additive (stabilizer) that improves the stability of the metal ions, and 4. a pH adjuster. In addition to these, the plating bath may also contain known additives such as a plating bath stabilizer.
The type of metal ions contained in the plating solution for plating can be appropriately selected depending on the type of metal to be deposited, and examples thereof include silver ions, copper ions, nickel ions, and cobalt ions.
The pH of the plating solution is not particularly limited, but in terms of achieving better effects of the present invention, it is preferably alkaline, more preferably 8.5 to 11.0, and even more preferably 9.0 to 10.5 at a temperature of 25°C.

The procedure for the above-mentioned plating treatment is not particularly limited, and any method can be used as long as it brings the silver wiring into contact with a plating solution. Examples of the method include a method of immersing a silver-containing layer in a plating solution and a method of applying a plating solution onto the silver wiring.
There are no particular restrictions on the contact time between the silver wiring and the plating solution, but from the viewpoint of the superior effect of the present invention and productivity, a contact time of 25 seconds to 30 minutes is preferred.
After contact with the plating solution, the silver wiring may be washed with water or neutralized with an acidic solution having a pH of 3 to 7, and the pH of the acidic solution is preferably 4 to 6. If the acidic solution has a pH of 3 to 7, sulfur and the like are not generated from sulfurous acid derived from the plating solution. In addition, an increase in the pH of the plating solution is suppressed, and the plating reaction can be stopped. The acidic solution functions as a plating stop solution.
The acidic solution preferably has a buffering effect, and a solids concentration of 0.1% by mass or more is preferred since it exhibits sufficient buffering ability.
The temperature of the plating solution is preferably 10 to 40°C, more preferably 15 to 30°C.
The contact time is not particularly limited, but is preferably 5 to 60 seconds in terms of the effects of the present invention being more excellent and productivity.

The above steps 2 and 3 may be repeatedly performed. That is, after step 3 is completed, steps 2 and 3 may be further performed.
The number of times that steps 2 and 3 are repeated is not particularly limited, but is preferably 2 to 4 times.

[Step 4]
The method for producing a conductive substrate may further include step 4 of plating the silver wiring between step 1 and step 2. By performing step 4, the conductivity of the silver wiring becomes more excellent.
The procedure of step 4 is the same as the procedure of step 3 described above, and therefore a description thereof will be omitted.
It should be noted that steps 4, 2, and 3 may be repeatedly performed. That is, after step 3 is completed, steps 4, 2, and 3 may be further performed.
The number of times that steps 4 to 3 are repeated is not particularly limited, but is preferably 2 to 4 times.
In step 4, as in step 3, after contact with the plating solution, the silver wiring may be washed with water or neutralized with an acidic solution having a pH of 3 to 7, and the pH of the acidic solution is preferably 4 to 6. If the acidic solution has a pH of 3 to 7, sulfur and the like are not generated from sulfurous acid derived from the plating solution. In addition, an increase in the pH of the plating solution is suppressed, and the plating reaction can be stopped.
The acidic solution preferably has a buffering effect, and a solids concentration of 0.1% by mass or more is preferred since it exhibits sufficient buffering ability.
As described above, step 3 or step 4 preferably includes a neutralization washing step in which the silver wiring is brought into contact with an acidic solution having a pH of 3 to 7 to stop the plating reaction during the plating process. Furthermore, as described above, the acidic solution preferably has a buffering effect. By using a buffer solution in the neutralization washing step, it is possible to prevent the pH from rising even if the plating solution is contaminated, and to uniformly stop the plating reaction.

[Step 5]
The method for producing a conductive substrate may further include step 5, between steps 1 and 2, or between steps 2 and 3, of contacting the silver wiring with a solution containing a quaternary ammonium salt. By carrying out this step, ions of the quaternary ammonium salt adhere to the surface of the silver wiring, which suppresses plating deposition on the surface of the silver wiring during the plating treatment in step 3 described below and makes it easier for the plating solution to penetrate into the silver wiring. As a result, metal (metal plating) is more likely to deposit within the silver wiring, achieving the desired effect.
Below, first, the solution used in step 5 will be described in detail, and then the procedure of step 5 will be described in detail.

(Solution containing quaternary ammonium salt)
The type of quaternary ammonium salt contained in the solution containing a quaternary ammonium salt (hereinafter also simply referred to as the "second solution") is not particularly limited, and is a compound having quaternary nitrogen.
The molecular weight of the quaternary ammonium salt is not particularly limited, but is preferably from 100 to 700, more preferably from 200 to 650, in terms of achieving better effects of the present invention.

The quaternary ammonium salt is preferably a compound represented by general formula (I) or a compound represented by general formula (II).
General formula (I) (R ¹ ) ₄ N ⁺ A ⁻

In formula (I), ^R1 's each independently represent an alkyl group which may have a substituent. The four ^R1 's may be the same group or different groups.
The number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 30, and more preferably 1 to 20.
The type of substituent that the alkyl group may have is not particularly limited, and examples thereof include a halogen atom, a hydroxyl group, a carboxyl group, an amino group, a cyano group, an aryl group (e.g., a phenyl group), an alkoxy group, an aryloxy group, an acyl group (e.g., an acetyl group), an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, a monoalkylamino group, a dialkylamino group, a monoarylamino group, and a diarylamino group.

In formula (II), ^R2 represents an alkyl group which may have a substituent.
Examples and suitable ranges of the alkyl group which may have a substituent and is represented by ^R2 include the examples and suitable ranges of the alkyl group which may have a substituent and is represented by ^R1 described above.

A ^- in general formulas (I) and (II) represents an anion. The type of anion is not particularly limited, and examples thereof include halogen ions (e.g., F ^- , Cl ^- , Br ^- , and I ^- ), HSO ₄ ^- , OH ^- , CH ₃ COO ^- , PF ₆ ^- , R ³ CO ₃ ^- , ClO ₄ ^- , BF ₄ ^- , SbF ₆ ^- , and AsF ₆ ^- . R ³ represents a hydrogen atom or an alkyl group which may have a substituent.
Examples and suitable ranges of the alkyl group which may have a substituent and is represented by ^R3 include the examples and suitable ranges of the alkyl group which may have a substituent and is represented by ^R1 described above.

As the quaternary ammonium salt, a compound represented by general formula (X), a compound represented by general formula (Y), or a compound represented by general formula (Z) is preferred, as they provide better effects of the present invention.

In general formula (X), R ^a1 and R ^a2 each independently represent an alkyl group having 4 or less carbon atoms which may have a substituent, and R ^a3 and R ^a4 each independently represent an alkyl group having 8 or more carbon atoms which may have a substituent.
The alkyl group represented by R ^a1 and R ^a2 , which may have a substituent, has 4 or less carbon atoms, and preferably 1 or 2 carbon atoms in terms of achieving better effects of the present invention.
The alkyl group represented by R ^a3 and R ^a4 , which may have a substituent, has 8 or more carbon atoms, preferably 8 to 30 carbon atoms, and more preferably 10 to 20 carbon atoms, in terms of achieving better effects of the present invention.
The types of substituents that the alkyl groups represented by R ^a1 and R ^a2 and the alkyl groups represented by R ^a3 and R ^a4 may have are not particularly limited, and examples thereof include a halogen atom, a hydroxyl group, a carboxyl group, an amino group, a cyano group, an aryl group, an alkoxy group, an aryloxy group, an acyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyloxy group, a monoalkylamino group, a dialkylamino group, a monoarylamino group, and a diarylamino group.

In general formula (Y), R ^b1 to R ^b3 each independently represent an alkyl group having 4 or less carbon atoms which may have a substituent, and R ^b4 represents an alkyl group having 10 or more carbon atoms which may have a substituent.
The alkyl group represented by R ^b1 to R ^b3 , which may have a substituent, has 4 or less carbon atoms, and preferably 1 or 2 carbon atoms in terms of achieving better effects of the present invention.
The alkyl group represented by R ^b4 , which may have a substituent, has 8 or more carbon atoms, preferably 8 to 30 carbon atoms, and more preferably 10 to 20 carbon atoms, in terms of achieving better effects of the present invention.
The types of substituents that the alkyl groups represented by R ^b1 to R ^b3 and the alkyl group represented by R ^b4 may have are not particularly limited, and examples thereof include the groups exemplified above as the substituents that the alkyl group represented by R ^a1 may have.

In formula (Z), R ^c1 represents an alkyl group having 10 or more carbon atoms which may have a substituent.
The alkyl group represented by R ^c1 , which may have a substituent, has 10 or less carbon atoms, preferably 10 to 30 carbon atoms, and more preferably 10 to 20 carbon atoms, in that the effects of the present invention are more excellent.
The type of substituent that the alkyl group represented by R ^c1 may have is not particularly limited, and examples thereof include the groups exemplified above as the substituent that the alkyl group represented by R ^a1 may have.

A 1 ⁻ in the general formulae (X) to (Z) represents an anion.
Examples of the anion represented by A 1 ^- in the general formulae (X) to (Z) include the anions exemplified as the anion of A 1 ^- in the general formulae (I) and (II) described above.

The second solution contains a solvent. The type of solvent is not particularly limited, and examples include water, organic solvents (e.g., alcohols, ketones, amides, sulfoxides, esters, and ethers), ionic liquids, and mixed solvents thereof. Of these, water is preferred.

The second solution may contain components other than the quaternary ammonium salt and solvent (e.g., the organic acid described above).

The content of the quaternary ammonium salt in the second solution is not particularly limited, but in terms of achieving better effects of the present invention, it is preferably 10 ⁻⁶ to 1 mass %, and more preferably 10 ⁻⁶ to 0.1 mass %, relative to the total mass of the second solution.

The pH value of the second solution is not particularly limited, but a pH of 3 to 7 at 25°C is preferred, and a pH of 4 to 6 is even more preferred, as this provides a more effective effect of the present invention.

(Procedure of step 5)
The method for contacting the silver wiring with the second solution is not particularly limited, and examples thereof include a method of immersing a substrate having silver wiring in the second solution and a method of applying the second solution onto the silver wiring.
The contact time between the silver wiring and the second solution is not particularly limited, but is preferably 5 to 180 seconds, more preferably 20 to 120 seconds, from the viewpoint of achieving better effects of the present invention and productivity.
The temperature of the second solution when it comes into contact with the silver wiring is not particularly limited, but is preferably 20 to 80°C, more preferably 30 to 70°C, in terms of achieving better effects of the present invention.

After contacting the silver wiring with the second solution, the silver wiring may be washed with a solvent (e.g., water) if necessary.

When step 5 is performed between step 1 and step 2, step 5, step 2, and step 3 may be repeatedly performed. That is, after step 3 is completed, step 5, step 2, and step 3 may be further performed.
The number of times that steps 5 to 3 are repeated is not particularly limited, but is preferably 2 to 4 times.

Furthermore, when step 5 is performed between step 2 and step 3, step 2, step 5, and step 3 may be repeatedly performed. In other words, after step 3 is completed, step 2, step 5, and step 3 may be further performed.
The number of times steps 2 to 5 are repeated is not particularly limited, but is preferably 2 to 4 times.

[Step 6]
The method for producing a conductive substrate may include, after step 3, step 6 of subjecting the silver wiring obtained in step 3 to a heat treatment. By carrying out this step, the strength of the silver wiring is improved.
The heat treatment carried out in step 6 may be the heat treatment carried out in step C described above.

[Step 7]
In the method for producing a conductive substrate, the silver wiring may be washed with a solvent after step 3 or after step 6. Examples of the solvent that can be used include water, organic solvents (e.g., alcohols, ketones, amides, sulfoxides, esters, and ethers), ionic liquids, and mixed solvents thereof.
Several types of solvents may be used for washing. For example, washing with an organic solvent may be followed by further washing with water.
As the solvent, a mixed solvent may be used, for example, a mixed solvent of an alcohol or an ether with water is preferred. As the alcohol, ethanol is preferred, and as the ether, diethylene glycol monoethyl ether or diethylene glycol monomethyl ether is preferred.

<Application>
The conductive substrate can be used in a variety of applications, including the above-mentioned touch panel or touch sensor, as well as semiconductor chips, various electric wiring boards, FPCs (Flexible Printed Circuits), COFs (Chip on Film), TABs (Tape Automated Bonding), antennas, multilayer wiring boards, and motherboards. In particular, the conductive substrate is preferably used in a capacitive touch panel among other touch panels.
When the conductive substrate is used in a touch panel, the silver wiring can effectively function as a detection electrode as described above. When the conductive substrate is used in a touch panel, in addition to the silver wiring having the predetermined properties described above, a conductive part having a different configuration from the silver wiring may be provided. This conductive part may be electrically connected to the silver wiring described above and be conductive.

The present invention is basically configured as described above. The conductive substrate and the method for manufacturing the conductive substrate of the present invention have been described in detail above, but the present invention is not limited to the above-described embodiments, and various improvements and modifications may of course be made without departing from the spirit and scope of the present invention.

The following examples further illustrate the features of the present invention. The materials, reagents, amounts and proportions of substances, and procedures shown in the following examples can be modified as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the following examples.

The conductive substrates of Examples 1 to 6 and Comparative Example 1 will be described below.
Example 1
(Preparation of Silver Halide Emulsion a)
To the following solution 1, maintained at a temperature of 38°C and a pH (hydrogen ion exponent) of 4.5, were added 90% of each of the following solutions 2 and 3 simultaneously over 20 minutes with stirring to form 0.07 µm grain nuclei. Subsequently, the following solutions 4 and 5 were added over 8 minutes, and then the remaining 10% of the following solutions 2 and 3 were added over 2 minutes to grow the grains to 0.09 µm. Furthermore, 0.15 g of potassium iodide was added, and the mixture was ripened for 5 minutes to complete grain formation.

1 liquid:
750ml water
Gelatin 8.6g
3g sodium chloride
1,3-dimethylimidazolidine-2-thione 20 mg
Sodium benzenethiosulfonate 10mg
Citric acid 0.7g
2 liquid:
300ml water
Silver nitrate 150g
3 liquid:
300ml water
38g sodium chloride
32g potassium bromide
Potassium hexachloroiridate (III) (0.005% KCl 20% aqueous solution) 5 ml
Ammonium hexachlororhodate
(0.001% NaCl 20% aqueous solution) 7ml
4 liquid:
100ml water
Silver nitrate 50g
5 liquid:
100ml water
13g sodium chloride
11g potassium bromide
Yellow prussiate 5mg

The mixture was then washed using the standard flocculation method. Specifically, the temperature was lowered to 35°C, and the pH was lowered using sulfuric acid until the silver halide precipitated (pH was in the range of 3.6 ± 0.2). Next, approximately 3 liters of the supernatant liquid was removed (first wash). Another 3 liters of distilled water was added, followed by sulfuric acid until the silver halide precipitated. Another 3 liters of the supernatant liquid was removed (second wash). The same operation as the second wash was repeated once more (third wash), completing the washing and desalting process. After washing and desalting, the emulsion was adjusted to pH 6.4 and pAg 7.5, and then chemically sensitized to optimal sensitivity at 55°C with 2.5 g of gelatin, 10 mg of sodium benzenethiosulfonate, 3 mg of sodium benzenethiosulfinate, 15 mg of sodium thiosulfate, and 10 mg of chloroauric acid. 100 mg of 1,3,3a,7-tetraazaindene was added as a stabilizer, and 100 mg of Proxel (trade name, manufactured by ICI Co., Ltd.) was added as a preservative. The final emulsion was a silver iodochlorobromide cubic grain emulsion containing 0.08 mol% silver iodide and a silver chlorobromide ratio of 70 mol% silver chloride and 30 mol% silver bromide, with an average grain size of 0.10 μm (100 nm) and a coefficient of variation of 9%.

(Preparation of Silver Halide Emulsion b)
Silver halide emulsion b was prepared by increasing the amount of ammonium hexachlororhodate (0.001% NaCl 20% aqueous solution) relative to silver halide emulsion a.

(Preparation of Photosensitive Layer-Forming Composition A)
To the above-mentioned silver halide emulsion a, 1.2× ¹⁰ mol/mol Ag of 1,3,3a,7-tetraazaindene, 1.2× ¹⁰ mol/mol Ag of hydroquinone, 3.0× ¹⁰ mol/mol Ag of citric acid, 0.90 g/mol Ag of 2,4-dichloro-6-hydroxy-1,3,5-triazine sodium salt, and a trace amount of hardener were added, and the pH of the coating solution was adjusted to 5.6 using citric acid.
To the above-mentioned coating solution, a polymer latex containing a polymer represented by the following formula (P-1) and a dispersant composed of a dialkylphenyl PEO sulfate (the mass ratio of dispersant/polymer was 2.0/100=0.02) was added so that the polymer/gelatin (mass ratio) became 0.5/1 relative to the gelatin contained therein.
Furthermore, EPOXY RESIN DY 022 (trade name: manufactured by Nagase ChemteX Corporation) was added as a crosslinking agent, and the amount of the crosslinking agent added was adjusted so that the amount of the crosslinking agent in the silver halide-containing photosensitive layer described below was 0.09 g/ ^m2 .
In this manner, a composition for forming a photosensitive layer was prepared.
The polymer represented by the following formula (P-1) was synthesized with reference to Japanese Patent Nos. 3,305,459 and 3,754,745.

(Preparation of Photosensitive Layer-Forming Composition B)
Photosensitive layer forming composition B was prepared in the same manner as photosensitive layer forming composition A, except that silver halide emulsion b was used.

(Photosensitive layer forming process)
The above-mentioned polymer latex was applied to both sides of a polyethylene terephthalate (PET) film having a thickness of 40 μm to provide an undercoat layer having a thickness of 0.05 μm.
Next, a silver halide-free layer having a thickness of 1.0 μm was formed on the undercoat layer by coating the composition for forming the silver halide-free layer, which was a mixture of the above-mentioned polymer latex and gelatin. The mixture mass ratio of the polymer to the gelatin (polymer/gelatin) was 2/1, and the polymer content was 0.65 g/ ^m2 .
Next, the above-described photosensitive layer-forming composition A was applied onto the silver halide-free layer to form a 1.6 μm-thick silver halide-containing photosensitive layer (first silver halide-containing layer). The mixture mass ratio of polymer to gelatin (polymer/gelatin) in the silver halide-containing photosensitive layer was 0.5/1, and the polymer content was 0.16 g/ ^m² .
Next, the above-described photosensitive layer-forming composition B was applied onto the first silver halide-containing layer to form a 0.4 μm-thick silver halide-containing photosensitive layer (second silver halide-containing layer). The mixture mass ratio of polymer to gelatin (polymer/gelatin) in the silver halide-containing photosensitive layer was 0.5/1, and the polymer content was 0.04 g/ ^m² .
Next, a protective layer having a thickness of 0.15 μm was formed on the silver halide-containing photosensitive layer by coating the protective layer-forming composition prepared by mixing the above-mentioned polymer latex and gelatin. The mixture mass ratio of the polymer to the gelatin (polymer/gelatin) was 1/1, and the polymer content was 0.08 g/ ^m2 .

(Exposure processing)
The prepared photosensitive layer was exposed to parallel light emitted from a high-pressure mercury lamp as a light source through an exposure mask having the detection parts (first detection electrode, second detection electrode) and extraction wiring parts shown in the figure.
The exposure mask used had the structure shown in Fig. 7. It had openings corresponding to the silver wire portions and the connection portions, and a halftone filter layer was provided on the light-shielding layer in the silver wire portions.
The developability of the photosensitive material is determined by the wavelength and light intensity of the light source, the light-shielding rate of the exposure mask, and the sensitivity characteristics of the photosensitive material. The light-shielding rate of the light-shielding layer and the sensitivity of silver halide emulsion b were appropriately adjusted so that both emulsion layers A and B were developed in areas where no light-shielding layer was provided, and emulsion layer A was developed but emulsion layer B was not developed in areas where a light-shielding layer was provided.

(Development processing)
After exposure, the film was developed with the following developer, and then developed with a fixer (product name: N3X-R for CN16X: manufactured by Fujifilm Corporation), rinsed with pure water, and then dried.

Developer composition:
The following compounds are contained in 1 liter (L) of the developer.
Hydroquinone 0.037 mol/L
N-methylaminophenol 0.016 mol/L
Sodium metaborate 0.140 mol/L
Sodium hydroxide 0.360 mol/L
Sodium bromide 0.031 mol/L
Potassium metabisulfite 0.187 mol/L

(Heat treatment)
Furthermore, the sample was left standing in a superheated steam bath at 120° C. for 130 seconds to carry out a heat treatment.

(Gelatin decomposition treatment)
The film was then immersed in a gelatin decomposition solution (40°C) prepared as follows for 120 seconds, and then washed by immersing in warm water (liquid temperature: 50°C) for 120 seconds.

Preparation of gelatin degradation solution:
Triethanolamine and sulfuric acid were added to an aqueous solution of a protease (Biophrase 30L, manufactured by Nagase ChemteX Corporation) (protease concentration: 0.5% by mass) to adjust the pH to 8.5.

(polymer cross-linking treatment)
The substrate was then immersed in a 1% aqueous solution of Carbodilite V-02-L2 (trade name: manufactured by Nisshinbo) for 30 seconds, removed from the aqueous solution, and immersed in pure water (room temperature) for 60 seconds to be washed.
In this way, a film A was obtained in which the detection electrodes and peripheral wiring were formed on both sides of the PET film.

Example 2
Example 2 differs from Example 1 in the thickness of the second silver halide-containing layer in the photosensitive layer forming step, but the other configurations were the same as Example 1. In Example 2, the thickness of the second silver halide-containing layer was 0.8 μm.
Example 3
Example 3 differs from Example 1 in the thickness of the second silver halide-containing layer in the photosensitive layer forming step, but the other configurations were the same as Example 1. In Example 3, the thickness of the second silver halide-containing layer was 1.6 μm.
Example 4
Example 4 differs from Example 1 in the thickness of the second silver halide-containing layer in the photosensitive layer forming step, but the other configurations were the same as Example 1. In Example 4, the thickness of the second silver halide-containing layer was 2.4 μm.
Example 5
Example 5 differs from Example 1 in the thickness of the second silver halide-containing layer in the photosensitive layer forming step, but the other configurations were the same as Example 1. In Example 5, the thickness of the second silver halide-containing layer was 3.2 μm.

Example 6
Example 6 differs from Example 2 in that the emulsion of the second silver halide-containing layer in the photosensitive layer forming step was different, but the other constitutions were the same as Example 2.
(Preparation of Silver Halide Emulsion c)
The preparation temperature of silver halide emulsion b was increased to give grains with an average grain size of 300 nm.
(Preparation of Photosensitive Layer-Forming Composition C)
In Example 6, which was prepared in the same manner as photosensitive layer-forming composition B except that silver halide emulsion c was used, photosensitive layer-forming composition C was applied to a thickness of 0.8 μm as the second silver halide-containing layer.

Comparative Example 1
Comparative Example 1 differed from Example 2 in the following respects, with the remaining configuration being the same as Example 2. In Comparative Example 1, exposure was performed using an exposure mask without a halftone filter layer.

The scratch resistance test, the electrical continuity reliability of the connection, the pattern misalignment, and the fine line drawing property were evaluated. The results are shown in Table 2 below.
The scratch resistance test, the electrical continuity reliability of the connection, the pattern misalignment, and the fine line drawing property will be described below.

[Scratch resistance test]
A durability test for pressure resistance was conducted by moving a friction member back and forth 10 times on the entire surface of the prepared conductive substrate using a test device for scratching, and then the resistance value between the terminals of the electrodes was evaluated using a digital multimeter 34410A (manufactured by Agilent), and the number of electrodes with a resistance value of 1 MΩ or more was evaluated. The evaluation criteria were as follows.
Evaluation criteria A: The number of electrodes with a 1 MΩ or larger is less than 5%. B: The number of electrodes with a 1 MΩ or larger is 5% or more but less than 10%. C: The number of electrodes with a 1 MΩ or larger is 10% or more but less than 50%. D: The number of electrodes with a 1 MΩ or larger is 50% or more.

[Connection reliability]
For the connection reliability, CP920CM-25AC (ACF (anisotropic conductive material) manufactured by Dexerials Corporation) was used.
A laminate was obtained by pressure-bonding a printed wiring board manufactured by Taiyo Kogyo Co., Ltd. and a connection portion of Film D (fresh) via CP920CM-25AC (ACF (anisotropic conductive material) manufactured by Dexerials Corporation). However, in order to forcibly evaluate the electrical continuity reliability of the connection portion, the pressure-bonding conditions were set to a temperature of 100°C, a pressure of 0.5 MPa, and 10 seconds, which were weaker than the manufacturer's recommended conditions. The electrical resistance value between the connection portion of the printed wiring board and Film D (or a comparable conductive substrate) immediately after pressure-bonding was measured. Next, a moist heat reliability test (temperature 60°C, relative humidity 90% for 10 days) was performed on the laminate, and then the electrical resistance value between the connection portion of the printed wiring board and Film D (or a comparable conductive substrate) was measured. The electrical continuity reliability of the connection portion was evaluated based on the rate of increase in electrical resistance before and after this moist heat reliability test. The evaluation criteria are as follows.
Evaluation Criteria A: The rate of increase in electrical resistance was less than 5%.
B: The rate of increase in electrical resistance was 5% or more and less than 10%.
C: The rate of increase in electrical resistance was 10% or more.
The increase in electrical resistance value after the moist heat reliability test indicates low adhesion reliability between the connection part of the conductive substrate and the ACF, i.e., peeling of the connection part of the conductive substrate and the ACF occurs after the moist heat reliability test.

[Pattern deviation]
Images of both sides of the conductive substrate, including the first and second silver wire portions, were obtained. The in-plane positions of the first and second silver wire portions in the images of each side were measured, and deviations from the design values were evaluated.
In Examples 1 to 6 and Comparative Example 1, the deviation from the design value was small, and all were evaluated as A.

[Fine line drawing performance]
During exposure, if the light incident on the silver halide deviates from parallel light and becomes more scattered, the lines will become thicker, and the exposure dose must be reduced to draw silver wiring, which reduces the amount of light in the depth direction and the amount of silver per line width. Based on the above, the exposure dose was changed to examine the relationship between line width and developed silver rate, and the fine line drawability was evaluated. The developed silver rate (%) is expressed as follows:
Developed silver rate = ((amount of silver per developed line width)/(amount of silver in coated silver halide)) x 100 (%). The evaluation criteria are as follows:
Evaluation criteria A: Developed silver ratio is 85% or more and less than 100% B: Developed silver ratio is 70% or more and less than 85% C: Developed silver ratio is 60% or more and less than 70% D: Developed silver ratio is less than 60%

As shown in Table 2, Examples 1 to 6 were superior to Comparative Example 1 in the scratch resistance test, the electrical connection reliability of the connection, the pattern misalignment, and the fine line drawing property.
As for the scratch resistance, it was found from Examples 1 to 6 that the scratch resistance improved as the thickness of the resin layer on the first silver wire portion increased.
Regarding the electrical continuity reliability of the connection, as the thickness of the resin layer on the second silver wire portion increased, the electrical continuity reliability of the connection deteriorated.
In the case of pattern misalignment, if the first silver line portion and the second silver line portion were not simultaneously exposed using the same exposure mask, pattern misalignment occurred.
In terms of fine-line printability, when the gap between the exposure mask and the silver halide layer was large, the light transmitted through the openings was diffracted, causing the light to spread, resulting in poor fine-line printability. Furthermore, when the exposure wavelength was increased, the diffraction increased, resulting in poor fine-line printability. Furthermore, when the average particle size of the silver halide in the second silver halide-containing layer was large, light scattering by the silver halide particles caused light bleeding, resulting in poor fine-line printability of the silver halide in the first silver halide-containing layer.

DESCRIPTION OF SYMBOLS 10 Image display device 11A First conductive layer 11B Second conductive layer 12 Touch panel 13 Controller 14 Image display unit 14a Display surface 14b Back surface 16 Cover layer 16a Front surface 16b Back surface 18 Conductive substrate 19 Flexible circuit board 20 Detection unit 22 Peripheral wiring unit 23a First peripheral wiring 23b Second peripheral wiring 24 Support 24a Front surface 24b Back surface 25a Undercoat layer 25b Antihalation layer 26a First external connection portion 26b Second external connection portion 27 Resin layer 28 Protective layer 28a, 28b Surface 29A First detection electrode layer 29B Second detection electrode layer 30 First detection electrode 31a First dummy electrode 31b Second dummy electrode 32 Second detection electrode 33 First electrode terminal 34 Second electrode terminal 35 Silver wiring 36 Opening 37 First silver wire portion 38 Second silver wire portion 39 Anisotropic conductive member 40 First silver halide-containing layer 42 Second silver halide-containing layer 43 Laminate 44 Exposure mask 45 Glass substrate 46 Light-shielding layer 47, 47a Opening 48 Halftone filter layer _E1 Detection area _E2 Peripheral area _H1 Thickness _H2 Thickness Lv Parallel light _d1 , _d2 , ta Thickness Wc Width

Claims (9)

a step of preparing a laminate having, in this order, a support, a first silver halide-containing layer containing silver halide, and a second silver halide-containing layer containing silver halide and having a lower sensitivity than the first silver halide-containing layer;
a step of exposing the laminate using a halftone mask so that there are regions with different cumulative exposure amounts in the first silver halide-containing layer and the second silver halide-containing layer, so that first silver line portions and second silver line portions having different thicknesses are formed, and developing the exposed silver layer to form silver wiring;
A method for manufacturing a conductive substrate, wherein the first silver wire portion constitutes a conductive layer, the second silver wire portion constitutes an external connection portion, and the thickness of the first silver wire portion is thinner than the thickness of the second silver wire portion . The method for producing a conductive substrate according to claim 1, wherein the average particle size of the silver halide contained in the second silver halide-containing layer is 250 nm or less. The method for producing a conductive substrate according to claim 1 or 2, wherein the second silver halide-containing layer has a thickness of 0.4 to 3.2 μm. the step of preparing the laminate includes a step of forming a crossover cut layer, the first silver halide-containing layer, and the second silver halide-containing layer in this order on both sides of the support,
The method for manufacturing a conductive substrate according to any one of claims 1 to 3, wherein the step of forming the silver wiring includes a step of exposing and developing the laminate so that there are regions on both surfaces of the support where the integrated exposure amount is different. A support;
a first silver wire portion and a second silver wire portion disposed on at least one of both surfaces of the support;
a resin layer disposed so as to cover the first silver wire portion and the second silver wire portion,
the first silver wire portion constitutes a conductive layer, and the second silver wire portion constitutes an external connection portion;
the thickness of the resin layer on the first silver wire portion is greater than the thickness of the resin layer on the second silver wire portion;
A conductive substrate, wherein the thickness of the first silver wire portion is thinner than the thickness of the second silver wire portion. the first silver wire portion and the second silver wire portion are disposed on both surfaces of the support,
the resin layer is disposed so as to cover the first silver wire portion and the second silver wire portion,
the thickness of the resin layer on the first silver wire portion is greater than the thickness of the resin layer on the second silver wire portion;
The conductive substrate according to claim 5 , wherein the thickness of the first silver wire portion is thinner than the thickness of the second silver wire portion. The conductive substrate described in claim 5 or 6, wherein the thickness of the resin layer on the first silver wire portion is at least 1.5 times the thickness of the resin layer on the second silver wire portion. The conductive substrate described in any one of claims 5 to 7, wherein the thickness of the resin layer on the second silver wire portion is 0.2 μm or less. The conductive substrate described in any one of claims 5 to 8, wherein the sheet resistance of the first silver wire portion is 50 Ω/sq or less.