JP2002196685A - Substrate with transparent electrode, method for manufacturing the same and its use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a material which can effectively shield electromagnetic waves leaking from the front face of a display without degrading the display quality, to provide a method for manufacturing the material and to provide a display panel using the material. SOLUTION: A substrate with transparent electrodes has transparent electrodes 12 formed in stripes on one surface of a transparent substrate 11 and has a pattern of a conductive layer 15 on the other surface of the substrate, with the conductive layer 15 formed in stripes or a grid having at least lines overlapping with the stripe pattern of the transparent electrodes or lines perpendicular to the stripe pattern of the transparent electrodes 12. The method for manufacturing the substrate with transparent electrodes is also disclosed. The substrate with transparent electrodes is used as one substrate of a display panel, for example, the front substrate of the panel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate with a transparent electrode constituting a color display device that generates harmful electromagnetic waves to the surroundings, and more particularly to a plasma display panel (hereinafter referred to as "PDP"). The present invention relates to a substrate with a transparent electrode provided with a function of shielding harmful electromagnetic waves generated from a display such as abbreviated). The present invention also relates to a method for manufacturing such a substrate with a transparent electrode, and further to a display panel using the substrate with a transparent electrode.

[0002]

2. Description of the Related Art A harmful electromagnetic wave leaks from a discharge type display such as a cathode ray tube or a PDP, which may affect the human body and various systems. In use, it is necessary to shield the electromagnetic wave by some means.

[0003] PDPs include an AC (AC) type and a DC (DC) type, and AC-type PDPs include an opposed discharge type and a surface discharge type. A description will be given with reference to FIG. 4 focusing on an AC surface discharge type PDP which has already started mass production. The PDP generally has a front substrate 10 and a rear substrate 20, in which a discharge gas is hermetically sealed between the two substrates, and performs light emission and display by discharge based on voltage application. Here, the front surface means the surface on the observer side, and the rear surface means the surface on the opposite side. The front substrate 10 includes a front transparent substrate 11 and a plurality of transparent electrodes 12 and 12 formed in stripes on the rear surface thereof. These transparent electrodes are covered with a front-side dielectric layer 13 and further include magnesium oxide. And the like. Transparent electrode 12, 1
A thin bus electrode (not shown) is usually provided on 2.

On the other hand, the rear substrate 20 is
Further, address electrodes 22, 22 are provided on the front surface thereof in a direction orthogonal to the transparent electrodes 12, and these address electrodes 22, 22 are covered with a backside dielectric layer 23. Then, phosphors 25R, 25G, and 25B corresponding to red, green, and blue are provided on a surface of the rear-side dielectric layer 23 facing the address electrodes 22, 22, and barrier ribs 27, 25 are provided between the phosphors. Separated by 27. The barrier ribs 27, 27 are provided to prevent influence on adjacent cells at the time of address discharge and prevent light crosstalk, and are generally made of a glass material. For forming the barrier ribs, a method is generally used in which a predetermined shape is formed with a paste containing glass called a rib paste, which is then fired to remove the resin component. Examples of a method for forming a rib with a rib paste include a screen printing method, a sand blast method, and a photosensitive paste method. There is also a method of forming a barrier rib by directly cutting a glass substrate by a sand blast method without using a rib paste.

In such an AC surface discharge type PDP, a voltage is applied to a pair of adjacent transparent electrodes 12, 12 provided in stripes on the rear side of the front transparent substrate 11, and a voltage is applied. I do. A voltage is applied to the address electrodes 22, 22 only at the time of addressing, and a discharge occurs. On the other hand, the direct discharge between the transparent electrode provided in the form of a stripe on the back side of the front substrate and the electrode provided in the form of a stripe in the direction orthogonal to the back substrate is an AC opposed discharge type. PDP. The electrode on the front substrate is used as a cathode and the electrode on the rear substrate is used as an anode.
It is a C-type PDP. In FIG. 4, the red phosphor 25
R, the green phosphor 25G and the blue phosphor 25B constitute a set, and only the range of this set of phosphors is shown on the rear substrate 20, but in an actual PDP, such a phosphor is used. Are arranged side by side, and only two pairs (four) of the transparent electrodes 12, 12 are illustrated in the front substrate 10, but in an actual PDP, many such transparent electrodes are arranged. It is arranged in. Also, the transparent electrode 12,
12 actually terminates at the end of the front transparent substrate 11, but in FIG.
2 and 12 are displayed slightly protruding to the right of the front transparent substrate 11.

As described above, there is leakage of electromagnetic waves from such a discharge type display. As a method of blocking the electromagnetic waves leaking from the display surface, an electromagnetic wave shielding film is attached to the viewer side of the display. And a method of separately mounting an electromagnetic wave shielding plate on the viewer side of the display. These electromagnetic wave shielding materials include indium-tin oxide (hereinafter abbreviated as “ITO”) films, silver-metal oxide multilayer films and other transparent conductive films formed on a transparent substrate, and polyester materials. A metal mesh is plated on the surface of a fiber mesh, and a conductive mesh obtained by etching a copper foil into a mesh shape is used. In particular, since a PDP is strong in electromagnetic waves leaking from the front surface, a mesh-type PDP having higher electromagnetic wave shielding performance is used for consumer use where electromagnetic wave regulations are strict.

On the other hand, in a discharge type color display, color display is performed by emitting red, green and blue cells in a display portion as necessary. In the PDP, as described above, display is performed by emitting red, green, and blue phosphors formed in a stripe shape. Although the forming method and position of the red, green and blue phosphors vary depending on the panel, in the case of PDP, as described above, the phosphor layer is usually formed on the front side of the back glass. Depending on the panel, the phosphor may be arranged in a cell shape. Further, in order to make the display color clear, a black line is often formed at the boundary between the phosphors of different colors, and this is the barrier rib described above for the PDP. For simplicity, in the present specification, the pattern of the phosphor boundary portion of a different color is referred to as a “phosphor boundary pattern”.

[0008]

When the above-mentioned mesh-shaped electromagnetic wave shielding material is pasted or attached to the front surface of the display panel, the pattern of the stripe-shaped or cell-shaped phosphor and the mesh pattern are mutually reciprocated. There was a problem that so-called "moire fringes" were easily generated by the action. A similar problem also occurs in a transparent electrode (scanning line) in a display. Therefore, when using a conductive mesh as an electromagnetic wave shielding material, by optimizing the angle between the scanning line or the pattern arrangement of the phosphor and the mesh line in the display panel, by making the moire fringes as inconspicuous as possible, The current situation is addressing this problem.

Therefore, there is a need for an electromagnetic wave shielding material that effectively blocks electromagnetic waves leaking from the front of the display and does not deteriorate the display quality of the display. An object of the present invention is to form a different form from a conventional electromagnetic wave shielding material used by being bonded or attached to the front of a display panel, and to effectively block electromagnetic waves leaking from the front of the display without deteriorating the display quality of the display. And a method of manufacturing the same, and a display panel using the same.

[0010] As a result of the study, it has been found that a transparent electrode or a conductive substrate pattern is formed on a transparent substrate with a transparent electrode used in manufacturing a display panel so as to overlap the transparent electrode or / and the phosphor boundary pattern of the panel. The inventors have found that the object can be achieved, and have completed the present invention.

[0011]

That is, according to the present invention, a transparent substrate is provided with a transparent electrode formed in a stripe on one surface and a conductive layer pattern is formed on the other surface. The conductive layer pattern is to provide a transparent electrode-attached substrate having a stripe or lattice shape having at least one line out of a line overlapping the transparent electrode stripe pattern and a line orthogonal to the transparent electrode stripe pattern. .

The substrate with a transparent electrode includes a step of forming a transparent electrode pattern in a stripe shape on one surface of the transparent substrate and a step of forming a pattern of a conductive layer on the other surface of the transparent substrate. The layer pattern is formed in a stripe shape so as to overlap the stripe pattern of the transparent electrode, or is formed in a stripe shape in a direction orthogonal to the stripe pattern of the transparent electrode, or a line in one direction is the stripe pattern of the transparent electrode. It can be manufactured by a method of forming a lattice so as to overlap. At this time, the pattern of the conductive layer is advantageously formed by printing using a conductive resin composition.

Further, the above-mentioned substrate with a transparent electrode can be used as a base substrate of a discharge type display panel which generates harmful electromagnetic waves. Therefore, according to the present invention, there is also provided a display panel in which the above substrate with a transparent electrode is arranged as one substrate. This substrate with a transparent electrode is advantageously used particularly as a front substrate for a plasma display. In this case, the substrate has a stripe shape in a direction orthogonal to the stripe-shaped transparent electrode of the front substrate, facing the surface having the transparent electrode of the front substrate. And a back substrate provided with a phosphor provided in the first and second and a barrier rib for separating the phosphors from each other. When the conductive layer pattern has a line in a direction orthogonal to the transparent electrode stripe pattern on the substrate with a transparent electrode, the line interval of the conductive layer in the direction orthogonal to the transparent electrode stripe pattern is set to the barrier rib of the rear substrate. It is arranged so as to coincide with the interval, and the line of the conductive layer overlaps the barrier rib.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With respect to a substrate with a transparent electrode according to the present invention, the form of the transparent electrode and the form of the pattern of the conductive layer are shown in FIG.
The transparent electrodes 12 and 12 are formed on one surface of the transparent substrate 11 in a stripe shape, and the conductive layers 15 and 15 are formed on the other surface in a stripe or lattice pattern. . One form of the pattern of the conductive layers 15, 15 is as shown in FIG.
The stripe pattern is formed so as to overlap the second stripe pattern. In another embodiment, as shown in FIG. 1B, the transparent electrodes 12 are formed in a stripe shape in a direction orthogonal to the stripe pattern. In still another embodiment, as shown in FIG. 1C, a line is formed in a lattice shape such that lines in one direction overlap the stripe pattern of the transparent electrodes 12 and 12. In the case of a lattice pattern as in the last example, the lines in two directions are usually formed so as to be orthogonal to each other.

FIG. 2 is a schematic longitudinal sectional view showing one embodiment of the substrate with a transparent electrode according to the present invention. This figure corresponds to the state shown in FIG. 1A or 1C which is cut in the vertical direction perpendicular to the transparent electrodes 12, 12, but the illustrated range is made wider than that of FIG. ing. As can be seen from FIG. 2, when the patterns of the conductive layers 15, 15 are provided in parallel with the transparent electrodes 12, 12, the stripe pattern of the transparent electrodes 12, 12 and the conductive layer 1 are formed on the front and back surfaces of the transparent substrate 11.
The lines 5 and 15 are overlapped. 1B is the same as FIG. 2 except that the stripe pattern of the conductive layers 15 and 15 is in a direction orthogonal to the stripe pattern of the transparent electrodes 12 and 12. It is.

The transparent substrate 11 can be made of an appropriate material depending on the specifications of the display panel to be used. When the display panel is a PDP, a glass plate is usually used because it has resistance to the conditions of the electrode forming step, but a transparent resin, for example, an ester resin such as polyethylene terephthalate may be used. In the case of a large PDP, it is preferable to use a glass with a high strain point since expansion and contraction of the substrate due to heating cannot be ignored.

The substrate with a transparent electrode of the present invention basically comprises
A transparent electrode 1 having a stripe shape is formed on one surface of a transparent substrate 11.
Steps of forming patterns 2 and 12 and transparent substrate 11
It is manufactured through a step of forming a pattern of the conductive layers 15 on the other surface of the substrate. At this time, the pattern of the conductive layers 15 and 15 is formed in a stripe shape so as to overlap with the pattern of the transparent electrodes 12 and 12, or is formed in a stripe shape in a direction orthogonal to the pattern of the transparent electrodes 12 and 12 or The electrodes are formed in a lattice shape such that the lines in one direction overlap the patterns of the transparent electrodes 12 and 12. Either the step of forming the pattern of the transparent electrodes 12, 12 or the step of forming the pattern of the conductive layers 15, 15 may be performed first.

The transparent electrodes 12 on the transparent substrate 11 are
Although it can be formed using a known material, generally, ITO or tin oxide is preferably used. In addition, a silver-dielectric multilayer film can be cited as an example. In order to form a pattern of the transparent electrodes 12 on the transparent substrate 11, a known method can be adopted. Examples of the method for forming the transparent electrode pattern include a method using photoetching, a method in which ITO is pasted and printed.

The transparent electrode 12,
The case of forming 12 will be described in more detail.
After cleaning the transparent substrate 11, the IT
A transparent conductive layer such as O is formed. A photoresist is applied over the entire surface and prebaked at a temperature of about 90 ° C. to form a resist film. Next, after exposing through a mask and developing, a resist pattern is formed by photolithography of post-baking at a temperature of about 120 ° C. As a result, the portion remaining as the transparent electrode is masked with the resist pattern, and the other portions are in a state where the transparent conductive layer is exposed. The exposed transparent conductive layer is removed by etching with an acid-based etchant using the resist pattern as a mask, and the transparent substrate 11 appears at that portion. Finally, if the resist film is peeled off, the portion masked by the resist pattern remains as a pattern of the transparent electrodes 12 and 12. On the other hand, in the case of printing, the ITO may be pasted, printed on a desired portion by a method such as screen printing, and baked to form a pattern of the transparent electrodes 12.

The transparent electrodes 12, 12 are formed in a stripe shape, and the line width, line interval, thickness, and the like of the transparent electrodes 12 and 12 vary depending on the size of the display panel on which the substrate with the transparent electrodes is used. Means that the line width is 20 to 200
The line spacing is about 100 to 1,000 .mu.m, and the thickness is about 10 to 500 nm.

In the case of an AC type PDP substrate, the transparent electrode 1
After the formation of the metal electrodes 2 and 12, a metal electrode called a bus electrode is further formed on the transparent electrodes 12 and 12. The bus electrode is provided to prevent a voltage drop due to the electrical resistance of the transparent electrodes 12 and 12. However, the presence of the bus electrode blocks the emitted light and reduces the luminance, so that a necessary line resistance can be obtained. It is desirable to make it as thin as possible. Therefore, the bus electrode is generally formed by a photo-etching method. Examples of the bus electrode include a Cr / Cu / Cr electrode and the like. The photoetching method itself can be performed by the same photolithography and etching as described above for the production of the transparent electrode pattern. However,
For the etching, an etchant suitable for the metal constituting the bus electrode is used. For example, when the bus electrode is made of Cr / Cu / Cr, the etchant is selected according to each metal layer.

In the substrate with a transparent electrode according to the present invention, the transparent electrode 1 formed in stripes on the transparent substrate 11 is formed.
The patterns of the conductive layers 15 and 15 are formed on the surface opposite to the surfaces 2 and 12. This conductive layer pattern is formed by the scanning electrodes (transparent electrodes 12, 12) of the panel and the phosphor boundary pattern (the barrier ribs 27, 27 of the rear substrate 20 in the PDP shown in FIG. 4) formed on the panel substrate when the panel is assembled. )
And are formed to overlap. By doing so, the conductive layer 1
It is possible to provide electromagnetic wave shielding performance while preventing the occurrence of moiré fringes due to interference between the pattern 5 and the pattern of the scanning electrode (transparent electrode 12) and / or the phosphor boundary pattern (the pattern of the barrier rib 27). . Conductive layer 1
When the lines 5 and 15 are formed in a direction parallel to the transparent electrodes 12 and 12, each of the former lines is at least partially overlapped with the latter pattern. No need. Also in the case where the lines of the conductive layers 15 are formed in a direction orthogonal to the transparent electrodes 12, if the former lines are used for a PDP, for example, so that each line at least partially overlaps with the phosphor boundary pattern, FIG. The barrier ribs 27, 2 of the rear substrate 20 shown in FIG.
It is sufficient that the pattern overlaps at least partly with the pattern 7, and it is not necessary to make the pattern exactly the same as the phosphor boundary pattern. Further, a part of the conductive layer pattern is designed so that a part thereof is connected to the ground when assembled into a panel. By doing so, the electromagnetic wave is more effectively cut off.

The line width of the conductive layers 15 is determined by the electromagnetic wave shielding performance and the appearance at the time of assembling the display, but is preferably in the range of 10 to 100 μm.
When the line width is less than 10 μm, sufficient electromagnetic wave shielding performance becomes difficult to develop, and it tends to be difficult to form a conductive layer pattern so as to prevent disconnection or the like. On the other hand, when the line width of the conductive layers 15 and 15 exceeds 100 μm,
The light emitting part will be covered more than necessary with the conductive layer pattern,
It is not preferable because the brightness of the display is impaired. As described above, it is preferable that the line width of the conductive layers 15 and 15 be as small as possible within a range where the required electromagnetic wave shielding performance is exhibited. Therefore, the lines of the conductive layers 15 and 15 are formed in a direction parallel to the transparent electrodes 12 and 12. In such a case, generally, the transparent electrode 12,
12 or smaller than the line width of 12,
The lines in the same direction as the transparent electrodes 12, 12 of the conductive layers 15, 15 are made to substantially overlap with the patterns of the transparent electrodes 12, 12 on the front and back surfaces of the transparent substrate 11, or the transparent electrodes are shown in a plan view. It is preferable to make it fit within the 12 and 12 patterns. The line spacing between the conductive layers 15 and 15 is the same as that of the transparent electrodes 12 and 12
4 and / or phosphor boundary patterns existing on the rear substrate (in the PDP shown in FIG. 4, barrier ribs 27 and 2
It is determined according to the line spacing of 7), and is generally 100 to 6
It is about 00 μm. If desired, the line spacing of the conductive layers 15, 15 may be set to 1,0 according to the line spacing of the transparent electrodes 12, 12.
It can be expanded to about 00 μm.

The conductive layers 15, 15 contain a conductive substance for imparting conductivity. Examples of the conductive substance constituting the conductive layers 15 and 15 include silver, an alloy containing silver, a metal such as gold, nickel, and aluminum, and an inorganic substance such as ITO, tin oxide, iron oxide, and titanium oxide.

The method of forming the conductive layer pattern having an electromagnetic wave shielding function is not particularly limited as long as it does not damage the transparent electrode formed on the back surface. However, from the viewpoint that the pattern can be easily formed, a printing method is used. It is preferable to form a conductive layer pattern. Above all, from the viewpoint that a fine pattern can be printed, offset printing, screen printing, or gravure printing is preferable. With these printing methods, since the dimensional accuracy is high, it is easy to print the pattern of the conductive layers 15 and 15 so as to overlap the pattern of the transparent electrodes 12 and 12 formed on the back surface of the transparent substrate 11. is there. Above all, filling the printing ink into the intaglio,
Intaglio offset printing is preferred in which the ink is transferred to a blanket cylinder, and the blanket cylinder is rotationally stamped and printed on the transparent substrate 11, which is a printing substrate.

The material for forming the conductive layer pattern having the electromagnetic wave shielding function is not particularly limited as long as it can form a pattern on the surface of the substrate and has appropriate conductivity or can impart appropriate conductivity. But not
From the viewpoint of forming a pattern by the above-described printing method, a resin composition is preferable. In order to form a conductive pattern using the resin composition, a conductive paste may be used as the resin composition. Known conductive pastes can be used. Here, the conductive paste is a composition comprising conductive particles and a binder, in which the conductive particles are dispersed in the binder. As the conductive particles, for example, silver, an alloy containing silver,
Examples include particles made of a metal such as gold, nickel, and aluminum, and inorganic fine particles made of a metal oxide such as an ITO powder. Examples of the binder include a polyester resin, an epoxy resin, and an acrylic resin. These binders may not be colored or may be colored.

In the case where the conductive pattern is whitish, when the panel is assembled, light emitted from the display panel is reflected on the back surface of the conductive pattern.
Display quality may be degraded. In such a case, if the binder is made black, it is possible to suppress the reflection of panel emission light on the back surface of the conductive pattern. To make the binder black, a colorant such as a black dye or pigment may be mixed with the binder. As the black colorant, for example, carbon, iron oxide, titanium black and the like can be used.

The proportion of the conductive particles and the binder used in the conductive paste is appropriately selected according to the desired conductive resistance of the conductive pattern and the adhesive strength to the transparent substrate. If the amount of the conductive particles is reduced, the adhesive strength with the transparent substrate is increased, but the conductive resistance is increased.On the contrary, if the amount of the binder is reduced, the conductive resistance is reduced, but the adhesive strength with the transparent substrate is reduced. Becomes smaller. This conductive paste may contain other additives, similarly to a normal conductive paste. Usually, the conductive paste is used by mixing with a solvent and adjusting the viscosity.

When the conductivity of the pattern obtained from the above-mentioned conductive paste is insufficient, if the transparent substrate 11 is made of glass, a pattern is formed with the conductive paste and then fired at a high temperature to remove organic substances. Thereby, the relative proportion of the conductive particles can be increased, and the conductivity of the pattern can be increased. In firing at high temperature, first, drying is performed to remove the solvent contained in the paste. The drying temperature is
Although it can be appropriately determined according to the boiling point of the solvent contained in the paste, it is usually in the range of 30 to 250 ° C., and a hot air oven, an infrared drying oven, or the like can be used as an apparatus. Firing at a high temperature after drying is performed using an electric furnace or the like. The firing temperature is
The temperature is usually in the range of 300 to 700 ° C., and is appropriately determined depending on the characteristics of the material used, the conductivity required for the obtained conductive layer pattern, and the like. The atmosphere at the time of firing may be selected as needed. For example, the firing is performed in air, in an inert gas such as nitrogen, or in a vacuum. Also, if necessary, bake
It is also possible to repeat annealing more than once, or to perform annealing in an inert gas such as nitrogen or in a vacuum after firing. In the case where a paste containing silver is used, it is preferable to bake at a temperature of 600 ° C. or less, and usually bake at a temperature of 500 to 600 ° C., in order to reduce coloring caused by transfer of silver to the transparent substrate 11. You.

Further, a pattern is formed by using a solution or a colloid solution of a compound which forms a metal oxide upon firing,
The conductive pattern can also be formed by drying and firing the obtained pattern. Compounds that generate metal oxides upon firing include alcoholates of indium and tin, acetylacetonate complexes, acetates,
Organic acid salts such as ethylhexanoate, and inorganic salts such as nitrates and chlorides of these metals. These compounds are used as a solution such as an alcohol solution or a colloid solution, and a pattern is formed by using the solution and the above-described printing method. Next, by performing drying and high-temperature sintering in the same manner as in the case where the conductivity obtained by sintering the pattern obtained from the conductive paste is increased, a pattern made of a conductive metal oxide can be formed.

When the conductivity of the pattern obtained from the resin composition is insufficient or not, the conductive pattern is formed by forming a conductive layer on the surface of the pattern formed by the resin composition. be able to. Examples of the metal constituting the conductive layer include copper, nickel, and the like. The metal layer may be a single layer, or may be a multilayer including two, three, or more layers. The uppermost layer of the conductive layer is preferably a black layer in order to suppress the reflection of visible light and enhance visibility. The thickness of the metal layer is
It is usually at most 20 μm, preferably at most 5 μm, and usually at least 0.1 μm. When imparting conductivity by coating the pattern surface with a metal layer, the resin composition itself forming the pattern does not need to have conductivity,
The resin composition may not include metal particles or inorganic particles having conductivity. However, in order to provide a metal layer with a uniform thickness by plating described later, it is advantageous that the pattern made of the resin composition has a certain degree of conductivity. Is preferably contained.

The method of providing a conductive layer on a pattern formed of a resin composition is such that a metal layer can be selectively provided on a pattern of a resin composition formed in advance.
Wet plating is preferred. As a method of providing a conductive layer on a pattern made of a resin composition by wet plating, a known method can be used, and usually, electrolytic plating or electroless plating is adopted, but the conductivity of the pattern itself is not sufficient. In this case, it is preferable to use electroless plating. In addition, in order to improve productivity, a substrate having a stripe-shaped or lattice-shaped pattern formed using a resin composition is subjected to electroless plating to provide a first pattern having uniform conductivity on the surface of the resin pattern. It is also effective to provide a second conductive layer with a desired thickness by applying electrolytic plating after providing the conductive layer. An example of a substrate with a transparent electrode in this case is shown in a schematic cross-sectional view in FIG. In this example, the transparent electrodes 12 and 12 are formed in a stripe shape on one surface of the transparent substrate, and the resin composition is formed on the other surface so as to overlap the stripe pattern of the transparent electrodes 12 and 12. An innermost layer 16 formed, a first conductive layer 17 provided on the surface by electroless plating, and a second conductive layer 18 provided on the surface by electrolytic plating are further formed. 16, the first conductive layer 17 and the second conductive layer 18,
Patterns 15 of the conductive layer are formed.

Even if the resin composition itself has sufficient conductivity for electrolytic plating, it is better to first provide uniform conductivity by electroless plating, and to achieve uniform thickness over a large area by electrolytic plating. It is more preferable because the conductive layer can be formed. Conditions for the electroless plating and the electrolytic plating are appropriately selected according to the physical properties of the resin composition used and the target electromagnetic shielding performance of the obtained substrate with a transparent electrode.

It is preferable that the outermost surface of the conductive layer 15 be a black layer in order to suppress the reflection of visible light and improve the visibility. In order to make the outermost surface a black layer, a method of coating with a black metal layer or a black electrodeposition layer, a method of oxidation or sulfidation, or the like can be adopted. To cover with a black metal layer, for example, in the above-mentioned plating, black nickel plating treatment, chromate plating treatment, black ternary alloy plating treatment using tin, nickel and copper, and black plating using tin, nickel and molybdenum. An original alloy plating treatment or the like may be applied. The black electrodeposition layer is a black layer provided by electrodeposition, and can be provided, for example, by electrodeposition coating using a black paint in which a black pigment is dispersed in an electrodeposition resin. Examples of the black pigment include carbon black and the like, and a conductive black pigment is preferable.
The electrodeposition resin may be an anionic resin or a cationic resin, and specifically, an acrylic resin,
Examples include polyester resin and epoxy resin. These electrodeposition resins can be used alone or in combination of two or more. Further, the metal surface can be blackened by an oxidation treatment or a sulfuration treatment. The oxidation treatment and the sulfidation treatment can be performed by a known method.

The substrate with a transparent electrode of the present invention can be used as a member of a display panel of a type manufactured by combining a front substrate and a rear substrate such as a PDP. Specifically, it can be used as a front substrate 10 of a PDP as shown in FIG. In the case of a PDP, a phosphor 25 provided in a stripe shape so as to be orthogonal to the stripe-shaped transparent electrodes 12, 12 of the front substrate 10 is opposed to the surface of the front substrate 10 having the transparent electrodes 12, 12.
A rear substrate 20 having R, 25G, 25B and barrier ribs 27, 27 for separating these phosphors is arranged. When the conductive layer pattern (15, 15 in FIG. 1 and the like) of the front substrate 10 has a line in a direction orthogonal to the transparent electrodes 12, 12, the line interval of the conductive layer is set to the line interval of the barrier ribs 27, 27. And the transparent electrodes 12, 1
The lines of the conductive layer in the direction perpendicular to the direction of the barrier ribs 27, 2
7 are arranged so as to overlap. The line spacing between the barrier ribs 27 varies depending on the size of the PDP, but is generally about 100 to 600 μm.

PDP using the substrate with a transparent electrode of the present invention
When a display panel is manufactured, the conductive layer pattern having the electromagnetic wave shielding performance is directly exposed to the outside (front side) of the panel. Therefore, to protect the electromagnetic wave shielding pattern, an adhesive is provided on the front side. It is preferable to attach a film or attach a protective plate by using such a method. The film to be bonded to the electromagnetic wave shield pattern surface of the panel is not particularly limited as long as it is optically transparent.For example, a film of a polyester resin such as polyethylene terephthalate, a film of a polyolefin resin such as polyethylene or polypropylene. Film, polycarbonate resin film, poly (meta)
A synthetic resin film such as an acrylate resin film is used, and its thickness is usually in a range of about 0.04 to 0.3 mm. The protective plate mounted on the front surface of the panel can be used without any particular limitation as long as it is a transparent substrate that can be arranged on the front surface of the display. For example, a glass substrate or a synthetic resin substrate can be used. Examples of the synthetic resin substrate include an acrylic resin plate, a polycarbonate resin plate, a polyester resin plate such as polyethylene terephthalate, a polyolefin resin plate such as polyethylene and polypropylene, and a polyether sulfone resin plate. No. When a glass plate is used, tempered glass is suitable from the viewpoint of preventing breakage. The thickness of the transparent protective plate is usually in the range of about 0.5 to 20 mm, preferably about 1 to 10 mm.

The above-mentioned film or protective plate may be colored with a coloring agent such as a dye or a pigment. Coloring is often used to enhance the legibility of the display. In this case, coloring may be performed by, for example, kneading a dye or the like into a material constituting the film or the protective plate, or a colored layer may be provided on the surface of the film or the protective plate. In the case of a protective plate, a similar function can be imparted by laminating a colored film on the surface. Further, when the panel is a PDP, a film or a protection plate having a near-infrared blocking function for absorbing near-infrared rays generated from the front of the panel may be attached. The near-infrared blocking function can be provided by a method substantially similar to the coloring method described above.

Further, if necessary, a hard coat layer, an antifouling layer, an antireflection layer, etc. can be formed on the surface of the film or the protective plate. In addition, functions may be imparted by laminating a film having these functions using an adhesive or the like. The coloring, near-infrared blocking function, hard coat layer, antifouling function, antireflection function, and the like may be provided independently, or a plurality of functions may be provided as necessary.

[0039]

Hereinafter, the present invention will be described in more detail with reference to specific examples, but the present invention is not limited to these examples. The percentages and parts in the examples are based on weight unless otherwise specified. Further, with respect to the electromagnetic wave shielding plates obtained in some examples, the line width of the conductive layer and the electromagnetic wave shielding performance were measured by the following methods.

(1) Line width The line width of the conductive layer pattern provided on the sample was measured with a microscope.

(2) Electromagnetic Wave Shielding Performance Using an electromagnetic wave shielding effect measuring device (“TR17301 type” manufactured by Advantest Co., Ltd.) and a network analyzer (“8753A” manufactured by Hewlett-Packard Co.), a frequency of 1 MHz to 1 GHz is used. The intensity of the electromagnetic wave was measured, and the value calculated by the following equation was defined as the electromagnetic wave shielding performance.

Electromagnetic wave shielding performance (dB) = 20 × log ₁₀ (X ₀ / X) In the equation, X ₀ represents the electromagnetic wave intensity when no electromagnetic wave shield plate is used, and X is the electromagnetic wave when the electromagnetic wave shield plate is used. Indicates strength.

The measurement was carried out using a test piece in which a square sample having a side of 200 mm was cut out from the obtained electromagnetic wave shielding plate and the ground was formed around the side surface with a copper tape. When the thickness of the test piece was 2 mm or less, it was backed with an acrylic plate of the same size and an appropriate thickness, and the measurement was performed while adjusting the thickness of the sample to about 3 mm.

Reference Example (Preparation of Resin Composition) 90 parts of silver particles “AgC-B” (particle diameter: 0.1 to 2.0 μm) manufactured by Fukuda Metal Foil & Powder Co., Ltd. and Degussa
0.9 parts of “DJ-600”, a black carbon manufactured by Sharp Corporation, is mixed with a roll disperser, and “Stafix PL-C” is a polyester resin manufactured by Fuji Photo Film Co., Ltd.
(Non-volatile content: 40%) 25.3 parts, mixed with 6.2 parts of "Dibasic Ester", a solvent manufactured by DuPont, and 6.0 parts of ethyl carbitol acetate as another solvent, and mixed with a conductive agent in a binder. The particles were dispersed to obtain a conductive resin composition. This composition was blackened by the colorant (carbon).

Example 1 (Printing of Conductive Paste on Transparent Substrate Surface) To 97 parts of the conductive resin composition obtained in the above Reference Example, 3 parts of ethyl carbitol acetate as a solvent was added, and the viscosity for screen printing was obtained. Was adjusted. When the viscosity of the conductive paste after the viscosity adjustment was measured with a rotational viscometer, it was 1 rp.
4,830 poise (483 Pa · s) at m, 6 at 10 rpm
26.75 poise (62.675 Pa · s), and the thixotropy ratio was 7.71. Using the conductive paste whose viscosity has been adjusted, a stripe-shaped conductive pattern is entirely formed on one surface of a glass plate having a size of 200 mm × 200 mm and a thickness of 0.7 mm by a screen plate having a line interval of 500 μm and a grid line width of 20 μm. To form a conductive stripe pattern composed of grid lines made of a conductive paste. Next, a conductive tape was attached around the side surface of the glass plate to produce an electromagnetic wave shield plate. In the obtained electromagnetic wave shielding plate, conductive stripe patterns 15 and 15 are formed on one surface of a glass plate 11 as schematically shown in FIG. 5 in a longitudinal sectional structure in a direction orthogonal to the conductive stripe pattern. A conductive tape 19 is provided around the side surface of the plate 11. The line spacing between the conductive stripe patterns 15, 15 was 500 μm (50 mesh), the width of the grid line was 39 μm, and the thickness of the grid line was 3 μm.

Example 2 (Plating of Conductive Layer) The glass plate (electromagnetic wave shield plate) obtained in Example 1 and on which a conductive stripe pattern was formed before the conductive tape 19 was provided, was concentrated with 35% concentrated hydrochloric acid. And then immersed in a copper plating solution at a temperature of 25 ° C. made up of 1 liter by mixing 180 g of copper sulfate pentahydrate, 27 g of sulfuric acid and ion-exchanged water. The pH of this copper plating solution was 0.7. An electrolytic copper electrode is immersed in this copper plating solution, and an electromagnetic wave shielding plate is used as a cathode and the electrolytic copper electrode is used as an anode.
A voltage of V was applied for 3 minutes to perform copper plating, and the grid lines were covered with a copper layer. Next, the electromagnetic wave shielding plate after the copper plating treatment was mixed with 75 g of nickel sulfate hexahydrate, 44 g of nickel ammonium sulfate, 30 g of zinc sulfate, 20 g of sodium thiocyanate and 1 g of ion-exchanged water to a temperature of 55 ° C. It was immersed in a nickel plating solution.
The pH of this nickel plating solution was 4.5. An electrolytic nickel electrode is immersed in this nickel plating solution, and a black nickel plating process is performed by applying a voltage of 3 V between both electrodes for 2 minutes while using the electromagnetic wave shielding plate as a cathode and the electrolytic nickel electrode as an anode. A nickel layer was provided as the uppermost layer. This top layer was black. Further, a conductive tape was attached around the side surface of the glass plate on which the stripe pattern having the black nickel plating layer as the uppermost layer was formed, thereby forming an electromagnetic wave shielding plate. The grid lines after black nickel plating had a width of 79 μm and a thickness of 18 μm.
50MHZ of electromagnetic wave shield plate after black nickel plating
The electromagnetic wave shielding performance at z was 39 dB.

Example 3 In Example 1 or 2, instead of using a glass plate, a glass plate having transparent electrodes formed in a stripe pattern on the back surface was used.
By performing the same treatment on the surface opposite to the surface with the transparent electrode, the substrate with a transparent electrode formed so that the conductive stripe pattern overlaps with the stripe pattern of the transparent electrode or in a direction perpendicular to it. Can be made. If this substrate with a transparent electrode is used as a front substrate when manufacturing a panel such as a PDP, a panel having an electromagnetic wave shielding function can be obtained. At this time, when the stripe-shaped conductive layer pattern is formed so as to overlap with the transparent electrode pattern formed on the back surface of the glass plate, it is possible to provide a panel free of moire fringes due to interference between the two. When the stripe-shaped conductive layer pattern is formed in a direction orthogonal to the transparent electrode pattern, the panel is also free from moiré stripes by arranging the conductive layer pattern so as to overlap the barrier ribs on the rear substrate. Can be.

Example 4 A conductive stripe pattern was formed in the same manner as in Example 1 except that a screen plate having a line interval of 400 μm and a grid line width of 40 μm was used. The obtained substrate with a conductive pattern was subjected to copper plating in the same manner as in Example 2, and further to nickel plating in the same manner as in Example 2, except that the time for black nickel plating was changed to 1 minute. Was. The grid line width after black nickel plating is 91 μm and the thickness is 1
It was 0 μm. The electromagnetic wave shielding performance of the electromagnetic wave shielding plate after black nickel plating at 50 MHz is 47 dB.
Met.

Example 5 In Example 4 above, a glass plate having transparent electrodes formed in stripes on the back surface was used instead of the glass plate, and the same treatment was performed on the surface opposite to the surface with the transparent electrodes. By performing the application, a substrate with a transparent electrode formed so that the conductive stripe pattern overlaps with the stripe pattern of the transparent electrode or in a direction orthogonal to the stripe pattern can be manufactured. If this substrate with a transparent electrode is used as a front substrate when manufacturing a panel such as a PDP, a panel having an electromagnetic wave shielding function can be obtained. At this time, in the case where the stripe-shaped conductive layer pattern is formed so as to overlap with the pattern of the transparent electrode formed on the back surface of the glass plate, a panel free of moire fringes due to interference between the two can be obtained. When the stripe-shaped conductive layer pattern is formed in a direction orthogonal to the transparent electrode pattern, the conductive layer pattern is arranged so as to overlap with the barrier rib on the back substrate, so that a panel having no moiré stripes is formed. be able to.

Example 6 In Example 1, the intaglio plate was filled with a printing ink composed of a conductive paste, the printing ink was transferred to a blanket cylinder, and the blanket cylinder was rotated and imprinted on a glass plate. The pattern of the conductive layer can be printed with high dimensional accuracy.

Example 7 If the pattern of the conductive layer is formed in a grid pattern, and one of the lines is formed so as to overlap the pattern of the transparent electrode formed on the back surface of the glass plate, a transparent electrode having a grid-shaped conductive layer pattern is provided. A substrate is obtained. Intaglio offset printing is advantageous for forming such a lattice pattern. This substrate with a transparent electrode is used as a front substrate when manufacturing a panel such as a PDP, and a conductive layer in a direction perpendicular to a line of the conductive layer formed so as to overlap the pattern of the transparent electrode overlaps a barrier rib on the rear substrate. With such arrangement, a panel free of moiré fringes can be obtained.

[0052]

Since the substrate with a transparent electrode of the present invention has an electromagnetic wave shielding performance itself, by using it as a front panel of a display panel, the leakage of the electromagnetic wave from the display panel is effectively suppressed. be able to. In this substrate with a transparent electrode, since the conductive layer pattern for electromagnetic wave shielding is provided in a specific positional relationship with the pattern of the transparent electrode, occurrence of moire fringes and the like is reduced, and good display quality is maintained. Can be. According to the present invention, such a substrate with a transparent electrode can be simply and advantageously manufactured.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing, in an enlarged manner, a part of each of three types of a substrate with a transparent electrode according to the present invention, wherein (A) shows a conductive layer overlapping with a stripe of the transparent electrode. An example in which a pattern is provided is shown, (B) shows an example in which a conductive layer pattern is provided in a direction orthogonal to the stripes of the transparent electrode, and (C) shows an example in which the conductive layer pattern is provided in a grid pattern.

FIG. 2 is a longitudinal sectional view schematically showing an example of a substrate with a transparent electrode according to the present invention.

FIG. 3 is a vertical cross-sectional view schematically showing a partially enlarged view of another example of the substrate with a transparent electrode according to the present invention.

FIG. 4 is a schematic perspective view for explaining a configuration of a plasma display panel.

FIG. 5 is a longitudinal sectional view schematically showing the configuration of the electromagnetic wave shielding plate obtained in Example 1.

[Explanation of symbols]

 10 front substrate, 11 transparent substrate (front side), 12 transparent electrode, 13 front dielectric layer, 14 protective layer, 15 conductive layer, 16 resin composition Formed innermost layer, 17: first conductive layer, 18: second conductive layer, 19: conductive tape, 20: rear substrate, 21: rear transparent substrate, 22: address electrode, 23: back side protective layer, 25R, 25G, 25B: phosphor, 27: barrier rib.

Claims (18)

[Claims] 1. A transparent substrate having a transparent electrode formed in a stripe shape on one surface and a conductive layer pattern formed on the other surface, wherein the conductive layer pattern is A substrate having a transparent electrode, wherein the substrate has a stripe shape or a lattice shape having at least one line out of a line overlapping the stripe pattern and a line orthogonal to the stripe pattern of the transparent electrode. 2. The substrate with a transparent electrode according to claim 1, wherein the pattern of the conductive layer is formed in a stripe shape so as to overlap the stripe pattern of the transparent electrode. 3. The substrate with a transparent electrode according to claim 1, wherein the pattern of the conductive layer is formed in a stripe shape in a direction orthogonal to the stripe pattern of the transparent electrode. 4. The pattern of the conductive layer is in a lattice shape, and a line in one direction overlaps the stripe pattern of the transparent electrode, and a line in the other direction is formed in a direction orthogonal to the stripe pattern of the transparent electrode. The substrate with a transparent electrode according to claim 1, wherein: 5. The substrate with a transparent electrode according to claim 1, wherein the pattern of the conductive layer has a line width of 10 to 100 μm. 6. The substrate with a transparent electrode according to claim 1, wherein the conductive layer contains a conductive substance selected from a metal and an inorganic substance. 7. The substrate with a transparent electrode according to claim 1, wherein the conductive layer has a layer made of a conductive resin composition. 8. A conductive layer comprising an innermost layer formed of a resin composition and a conductive layer provided on the surface of the innermost layer by electroless plating or electrolytic plating. The substrate with a transparent electrode according to 1. 9. An innermost layer formed of a resin composition, a first conductive layer provided on the surface of the innermost layer by electroless plating, and electrolytic plating on a surface of the first conductive layer. 6. A second conductive layer provided by the method according to claim 1.
The substrate with a transparent electrode according to any one of the above. 10. The substrate with a transparent electrode according to claim 7, wherein the resin composition contains a conductive substance selected from metals and inorganic substances. 11. The substrate with a transparent electrode according to claim 7, wherein the resin composition contains a black binder. 12. A method for forming a stripe-shaped transparent electrode pattern on one surface of a transparent substrate, and a process for forming a conductive layer pattern on the other surface of the transparent substrate. The stripe pattern is formed so as to overlap the stripe pattern of the transparent electrode, or the stripe pattern is formed in a direction orthogonal to the stripe pattern of the transparent electrode, or the line in one direction is overlapped with the stripe pattern of the transparent electrode. Characterized by being formed in a lattice shape,
A method for manufacturing a substrate with a transparent electrode. 13. The method according to claim 12, wherein the pattern of the conductive layer is formed by printing using a conductive resin composition. 14. The method according to claim 13, wherein the printing is performed by offset printing, screen printing, or gravure printing. 15. A pattern of a conductive layer is formed by providing a stripe-shaped or lattice-shaped pattern on one surface of a transparent substrate using a resin composition, and then applying electroless plating to the surface of the pattern. 13. The method according to claim 12, wherein the method is performed by providing one conductive layer and further performing electroplating to provide a second conductive layer on the surface of the first conductive layer. 16. A display panel, wherein the substrate with a transparent electrode according to claim 1 is arranged as one of the substrates. 17. A phosphor provided in a stripe shape in a direction perpendicular to the stripe-shaped transparent electrodes of the front substrate, opposite to the surface having the transparent electrodes of the front substrate, wherein the substrate with the transparent electrodes is a front substrate. 17. The display panel according to claim 16, further comprising a rear substrate provided with barrier ribs for isolating the phosphors, and for a plasma display. 18. A pattern of a conductive layer provided on a surface of a front substrate opposite to a transparent electrode has a line in a direction orthogonal to a stripe pattern of the transparent electrode, and a line interval of the conductive layer is set to be smaller than that of the rear substrate. 18. The display panel according to claim 17, wherein a distance between the barrier ribs is equal to a distance between the barrier ribs.