JP2007250641A - Protective board for plasma display, manufacturing method therefore, and plasma display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protective board for a plasma display which is low cost and superior in electromagnetic wave shielding performance, and to provide a method for inexpensively manufacturing the protective board with superior productivity, and a plasma display device where electromagnetic waves to be discharged from the front surface of a plasma display panel are fully shielded. <P>SOLUTION: The peripheral edges of a conductive film 40 arranged on a substrate 20 are folded on the end surfaces 22 of the substrate 20, and the protective board 10 is adhered onto the rear surface of the substrate 20. The method is for manufacturing the protective board 10 which is adhered onto the rear surface of the substrate 20, by folding on the end surfaces 22 of the substrate 20 the peripheral edges of the conductive film 40 that protrudes from the end surfaces 22 of the substrate 20. The plasma display device includes the protective board 10 arranged in the front part of the plasma display panel, where the substrate 20 of the protective board 10 is positioned on the side closer to the plasma display panel than to the conductive film 40. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a protective plate for plasma display, a manufacturing method thereof, and a plasma display device.

  Since electromagnetic waves are emitted from the front surface of the plasma display panel (hereinafter referred to as PDP), for the purpose of shielding the electromagnetic waves, an observer's side of the protective plate for plasma display arranged in front of the PDP is used. A conductive film is provided on the surface (Patent Document 1). And this electroconductive film is electrically connected to the earth | ground of a plasma display apparatus, in order to express electromagnetic wave shielding performance.

  Since the protective plate for plasma display is provided on the forefront of the plasma display main body, the connection between the conductive film and the ground of the plasma display main body needs to be performed on the PDP side of the protective plate for plasma display. Therefore, a conductive tape is provided on the periphery of the protective plate for plasma display to establish electrical continuity between the conductive film and the ground terminal installed on the PDP side of the protective plate for plasma display ( (Refer FIG. 2 of patent document 1).

However, when the conductive tape is provided on the peripheral edge of the plasma display protective plate, there are the following problems.
(I) Contact resistance is generated at the contact portion between the conductive film and the conductive tape, and the electromagnetic shielding performance is reduced.
(Ii) It takes time to apply the conductive tape to the entire peripheral portion of the protective plate for plasma display, resulting in poor productivity and high costs (personnel costs).
(Iii) The cost increases by the amount of the conductive tape.

In addition, the following are proposed as another protective plate for plasma displays having electromagnetic wave shielding performance.
(1) Electromagnetic shielding light transmission in which a metal mesh is sandwiched between two substrates, the metal mesh protruding from the two substrates is folded back along the edge of one substrate, and attached to the substrate with conductive tape Window material (Patent Document 2).
(2) An optical filter in which a metal mesh is sandwiched between two substrates and the metal mesh protruding from the two substrates is folded back along the edge of one substrate (Patent Document 3).

However, the electromagnetic wave shielding light transmitting window material (1) has the following problems.
(I) A conductive tape is required.
(Ii) Since the metal mesh is hard and difficult to handle, the productivity of the light transmissive window material may be poor.
(Iii) The metal mesh is likely to break, and when it is broken, sufficient conduction is not obtained and electromagnetic wave shielding performance is reduced.
(Iv) Two substrates are necessary to fix the metal mesh, and the cost is high.

The optical filter (2) has the following problems.
(I) When the metal mesh is folded back to the viewer side, a conductive tape is required to establish electrical continuity with the ground terminal installed on the PDP side.
(Ii) Since the metal mesh is hard and difficult to handle, the productivity of the optical filter may be poor.
(Iii) The metal mesh is likely to break, and when it is broken, sufficient conduction is not obtained and electromagnetic wave shielding performance is reduced.
(Iv) Two substrates are necessary to fix the metal mesh, and the cost is high.
JP 2005-183742 A Japanese Patent Laid-Open No. 11-84041 JP-A-9-147752

  The present invention relates to a protective plate for plasma display having excellent electromagnetic shielding performance and low cost; a method for producing a protective plate for plasma display having excellent electromagnetic shielding performance at low cost, and a front surface of a plasma display panel. An object of the present invention is to provide a plasma display device in which electromagnetic waves emitted from the substrate are sufficiently shielded.

  The protective plate for plasma display of the present invention has a substrate and a conductive film provided on the substrate, and a part or all of the peripheral portion of the conductive film is folded at the end surface of the substrate, It is affixed on the surface of the said board | substrate on the opposite side to the surface in which the said electroconductive film was provided.

The conductive film preferably has a film base and a conductive layer provided on the film base.
The conductive film is preferably provided such that the film base is on the substrate side.

The conductive layer may be a metal mesh.
The peripheral part of the metal mesh is preferably a non-mesh part in which no mesh is formed.
In the conductive layer, an oxide layer and a metal layer are alternately (2n + 1) layers [where n is an integer of 1 to 8. It may be a laminated conductive film.

The end surface of the substrate is preferably chamfered.
The protective plate for plasma display of the present invention may further have a functional film provided on the conductive film.

  The method for producing a protective plate for a plasma display according to the present invention includes a step of providing a conductive film on a substrate such that a part or all of a peripheral edge of the conductive film protrudes outside an end surface of the substrate; The conductive film is provided with the step of folding back the peripheral portion of the conductive film protruding outside the end surface of the substrate at the end surface of the substrate, and the peripheral portion of the conductive film folded back at the end surface of the substrate. And a step of attaching to the surface of the substrate opposite to the surface.

  The plasma display device of the present invention includes a plasma display panel and the protective plate for the plasma display of the present invention disposed in front of the plasma display panel, and the substrate of the protective plate for the plasma display is the conductive film. It is characterized by being located closer to the plasma display panel.

The protective plate for plasma display of the present invention is excellent in electromagnetic wave shielding performance and low in cost.
According to the method for producing a protective plate for plasma display of the present invention, a protective plate for plasma display having excellent electromagnetic shielding performance can be produced with high productivity and at low cost.
In the plasma display device of the present invention, electromagnetic waves emitted from the front surface of the plasma display panel are sufficiently shielded.

<Protective plate for plasma display>
The protective plate for plasma display of the present invention (hereinafter referred to as a protective plate) has a substrate and a conductive film provided on the substrate, and a part or all of the peripheral portion of the conductive film is formed. The substrate is folded at the end surface of the substrate, and is attached to the surface of the substrate opposite to the surface on which the conductive film is provided (hereinafter referred to as the back surface).

FIG. 1 is a schematic sectional view showing an example of the protective plate of the present invention. The protective plate 10 includes a substrate 20, a conductive film 40 provided on the substrate 20 with an adhesive layer 30 so that the film base 42 is on the substrate 20 side, and the conductive layer 44 is on the outside. This is a protective plate having a functional film 60 provided on the film 40 via an adhesive layer 50.
In the protection plate 10, the entire peripheral edge of the conductive film 40 is folded back at the end surface 22 of the substrate 20 and attached to the back surface of the substrate 20 via the adhesive layer 30.
The protection plate 10 is an example in which the conductive film 40 is provided so that the film base 42 is on the substrate 20 side.

FIG. 2 is a schematic sectional view showing another example of the protective plate of the present invention. The protective plate 12 includes a substrate 20, a conductive film 44 provided on the substrate 20 via an adhesive layer 30 so that the conductive layer 44 is on the substrate 20 side, and the film base 42 is on the outside. A functional film 60 provided on the film 40 via the adhesive layer 50 and an electrode 70 provided on the peripheral edge of the surface of the substrate 20 opposite to the surface on which the conductive film 40 is provided. It is a protective plate.
In the protective plate 12, the entire periphery of the conductive film 40 is folded back at the end surface 22 of the substrate 20, and the electrode 70 is electrically connected to the periphery of the back surface of the substrate 20 via the conductive adhesive layer 80. It is connected.
The protection plate 12 is an example in which the conductive film 40 is provided so that the conductive layer 44 is on the substrate 20 side.

(substrate)
The substrate is a transparent substrate having transparency. The term “transparent” means that light having a wavelength in the visible light region is transmitted. The substrate preferably transmits 70% or more visible light.
As a material of the transparent substrate, glass (including tempered glass such as air-cooled tempered glass and chemically tempered glass); polyethylene terephthalate (PET), triacetyl cellulose (TAC), polycarbonate (PC), polymethyl methacrylate (PMMA) And the like.

  The end face of the substrate is preferably chamfered from the viewpoint that the conductive layer of the conductive film is not easily broken and the conductive film is easily folded. The chamfering means that a ridge angle formed between the end surface of the substrate and the surface is taken to create a new surface. As shown in FIG. 3, the chamfering may be a thread chamfering that creates a new surface by obliquely cutting the ridge angle formed by the end surface 22 of the substrate 20 and the surface 24. As shown in FIG. Kamaboko chamfering may be used in which the ridge angle formed by the end surface 22 and the surface 24 is a curved surface having a radius R.

The amount, angle, etc. of the cut in thread chamfering are not particularly limited unless a sharp ridge angle of 90 ° or less is formed by chamfering.
The radius R in the kamaboko chamfering is preferably 0.5 mm or more and half or less of the thickness of the substrate. When the radius R is half of the thickness of the substrate, the end surface of the substrate is a curved surface with a semicircular cross section as shown in FIGS.

(Conductive film)
As an electroconductive film, what has a film base material and the conductive layer provided on this film base material is mentioned.
The film substrate is a transparent film substrate having transparency. Examples of the material for the film substrate include plastics such as polyethylene terephthalate (PET), triacetyl cellulose (TAC), polycarbonate (PC), and polymethyl methacrylate (PMMA).
Examples of the conductive layer include a metal mesh and a conductive film. When the conductive layer is a metal mesh, the conductive layer is not a uniform layer in the plane, but a layer made of a mesh-like metal wire. When the conductive layer is a conductive film, the conductive film is a uniform layer in the plane. The conductive film may be a film composed of only one layer, or may be a film in which a large number of layers are stacked. The conductive film is made of a transparent conductive film or a laminated film including the transparent conductive film.

Metal mesh:
When the conductive layer is a metal mesh, the conductive film is preferably provided on the substrate such that the film base is on the substrate side and the metal mesh (conductive layer) is on the outside. By directing the metal mesh to the outside, the metal mesh and the ground terminal of the plasma display device can be directly conducted without providing an electrode or the like on the back surface of the substrate.

As shown in FIG. 5, the metal mesh has a mesh portion 92 that transmits a PDP image, and a non-mesh portion 94 formed at the peripheral edge of the metal mesh 90. The non-mesh portion 94 is a portion where no mesh is formed, that is, a portion made of solid metal.
By making the peripheral portion of the metal mesh 90 a non-mesh portion 94, the conductive film can be easily folded back, the conductive film is not easily broken when folded, the contact area with the ground terminal of the plasma display device increases, and the contact resistance There are advantages such as low.
The width a of the non-mesh part 94 is preferably 3 to 150 mm, more preferably 5 to 100 mm, and further preferably 5 to 60 mm.

  Further, the metal mesh 90 is configured such that the peripheral edge of the conductive film 40 is not overlapped with the back surface of the substrate 20 when the peripheral edge portion of the conductive film 40 is folded at the end surface 22 of the substrate 20 and attached to the back surface of the substrate 20. Moreover, as shown in FIG. 5, the four corners may be cut.

  As a method of forming the conductive layer 44 made of the metal mesh 90 on the film base material 42, a method in which a copper foil is pasted on the film base material and then processed into a mesh shape by etching; After laminating metal, processing into mesh by etching; Method of bonding metal mesh such as fiber mesh on film substrate; Mesh method on film substrate by printing method such as screen printing, gravure printing, etc. Examples include a method of forming a pattern.

  The copper foil may be rolled copper or electrolytic copper. The copper foil may be subjected to various surface treatments. Examples of the surface treatment include blackening treatment, chromate treatment, roughening treatment, pickling, zinc / chromate treatment, and the like. 1-30 micrometers is preferable, as for the thickness of copper foil, 2-20 micrometers is more preferable, and 5-15 micrometers is especially preferable. By setting the thickness of the copper foil to 30 μm or less, the etching time can be shortened, and by setting the thickness to 1 μm or more, the electromagnetic wave shielding property is enhanced.

The opening ratio of the mesh portion 92 of the metal mesh 90 is preferably 60 to 95%, more preferably 65 to 95%, and particularly preferably 70 to 95%.
The shape of the opening of the mesh portion 92 of the metal mesh 90 is a regular triangle, a regular square, a regular hexagon, a circle, a rectangle, a rhombus, or the like. It is preferable that the openings have the same shape and are aligned in the plane.
As for the size of the opening, one side or the diameter is preferably 50 to 500 μm, and more preferably 100 to 400 μm. By setting one side or diameter of the opening to 500 μm or less, the electromagnetic wave shielding property is improved, and by setting it to 50 μm or more, there is little influence on the image of the PDP.

  As for the line | wire width of metal parts other than an opening part, 5-50 micrometers is preferable. That is, the arrangement pitch of the openings is preferably 55 to 550 μm. By making the line width 5 μm or more, processing becomes easy, and by making the line width 50 μm or less, there is little influence on the image of the PDP.

  The sheet resistance of the metal mesh 90 is preferably 0.01 to 10Ω / □, more preferably 0.01 to 2Ω / □, and particularly preferably 0.01 to 1Ω / □. If the surface resistance of the metal mesh 90 is lowered more than necessary, the thickness of the metal mesh 90 is increased, and the optical performance of the protective plate is adversely affected, such as being unable to secure a sufficient opening. On the other hand, if the surface resistance of the metal mesh 90 is increased more than necessary, sufficient electromagnetic wave shielding properties cannot be obtained.

  When laminating the copper foil on the film base 42, a transparent adhesive is used. Examples of the adhesive include acrylic adhesives, epoxy adhesives, urethane adhesives, silicone adhesives, and polyester adhesives. The adhesive type is preferably a two-component type or a thermosetting type. Moreover, as an adhesive agent, what was excellent in chemical-resistance is preferable.

  As a method of processing the copper foil into a mesh shape, a photoresist method can be mentioned. In the photoresist method, a photoresist material is formed on a copper foil by a roll coating method, a spin coating method, a full surface printing method, a transfer method, and the like, and an opening pattern is formed by exposure, development, and etching.

Conductive film:
When the conductive layer is a conductive film, the conductive film is preferably provided on the substrate such that the conductive film (conductive layer) is on the substrate side and the film base is on the outside. By setting the conductive film to the substrate side, oxidation of the metal layer included in the conductive film can be suppressed.

  Note that even when the conductive layer is a conductive film, the conductive film may be provided over the substrate such that the film base is on the substrate side and the conductive film (conductive layer) is on the outside. In this case, to suppress the oxidation of the metal layer contained in the conductive film, to ensure the conduction even if the conductive film cracks, for example, to cover the conductive film of the folded conductive film, A conductive tape may be applied from the peripheral portion on the front surface side of the substrate to the peripheral portion on the back surface side of the substrate.

The conductive film is a transparent conductive film having transparency and conductivity. Specifically, as shown in FIG. 6, the oxide layer 102 and the metal layer 104 are alternately (2n + 1) layers in total from the film base 42 side [where n is an integer of 1 to 8. The conductive film 100 is a laminated film.
The conductive film 100 preferably has n = 2 to 8, and more preferably n = 2 to 6. That is, the conductive film 100 preferably has 2 to 8 metal layers 104, more preferably 2 to 6 layers. If there are two or more metal layers 104, the resistance can be sufficiently reduced. If the metal layer 104 is 8 layers or less, the transparency of the conductive film 100 can be sufficiently secured.
The resistance of the conductive film 100 is preferably 3.5Ω or less, more preferably 2.5Ω or less, and particularly preferably 1.5Ω or less in order to sufficiently secure the electromagnetic wave shielding performance.

The oxide layer 102 is a layer containing a metal oxide.
The refractive index of the oxide layer 102 is preferably 1.55 to 2.5, more preferably 1.8 to 2.5, and particularly preferably 1.9 to 2.5. By setting the refractive index within this range, the transmittance can be increased by the interference effect with the metal layer 104. The refractive index means a refractive index at a wavelength of 555 nm.

  Examples of the metal oxide having a refractive index of 1.55 to 2.5 include metal oxides mainly composed of aluminum oxide, zinc oxide, indium oxide, titanium oxide, niobium oxide, tin oxide, and the like. Among these, zinc oxide, indium oxide, titanium oxide, and niobium oxide are preferable because the compatibility of the metal layer 104 with silver is good and the durability of the conductive film 100 can be improved.

The oxide layer 102 is preferably a layer made of zinc oxide containing one or more elements selected from the group consisting of tin, aluminum, chromium, titanium, silicon, boron, magnesium and gallium, and zinc oxide containing aluminum A layer containing zinc oxide (hereinafter referred to as GZO) containing gallium (hereinafter referred to as GZO) or zinc oxide containing titanium (hereinafter referred to as TZO) as a main component is particularly preferable. The oxide layer 102 preferably contains 90% by mass or more in total of Al ₂ O ₃ , Ga ₂ O ₃ or TiO ₂ and ZnO in terms of oxide, more preferably 95% by mass or more, and 99 It is particularly preferable to contain at least mass%. When the total content of Al ₂ O ₃ , Ga ₂ O ₃ or TiO ₂ and ZnO in the oxide layer 102 is in the above range, the adhesiveness between adjacent metal layers is excellent, and the moisture resistance is excellent.

The amount of aluminum in AZO is preferably 1 to 10 atomic percent, more preferably 2 to 6 atomic percent, and particularly preferably 1.5 to 5.5 atomic percent based on the total amount of aluminum and zinc.
The amount of gallium in GZO is preferably 1 to 10 atomic percent, more preferably 2 to 6 atomic percent, and particularly preferably 1.5 to 5.5 atomic percent, based on the total amount of gallium and zinc.
The amount of titanium in TZO is preferably 2 to 20 atomic percent, more preferably 3 to 15 atomic percent, based on the total amount of titanium and zinc.
When the amount of aluminum, gallium, or titanium is within the above range, the internal stress of the oxide layer 102 can be reduced, so that the possibility of cracking can be reduced. Moreover, the crystal structure of zinc oxide can be maintained.

  The physical film thickness (hereinafter simply referred to as film thickness) of the oxide layer 102 closest to the film base material 42 and the oxide layer 102 farthest from the film base material 42 is preferably 10 to 60 nm, and preferably 20 to 60 nm. More preferably, 30-50 nm is especially preferable. The thickness of the other oxide layer 102 is preferably 40 to 140 nm, particularly preferably 40 to 100 nm.

  One oxide layer 102 may be composed of two or more different types of oxide layers. For example, one oxide layer 102 has a two-layer structure of AZO layer / silicon dioxide layer; a three-layer structure of AZO layer / silicon dioxide layer / AZO layer; a three-layer structure of AZO layer / tin oxide layer / AZO layer; It may have a three-layer structure of zinc layer / tin oxide layer / zinc oxide layer; a three-layer structure of zinc oxide layer / silicon dioxide layer / zinc oxide layer.

The metal layer 104 is preferably a layer made of pure silver from the viewpoint of reducing the resistance value of the conductive film 100. Pure silver means that 99.9% by mass or more of silver is contained in the metal layer 104 (100% by mass).
The metal layer 104 is a layer made of a silver alloy containing one or more other metals selected from the group consisting of gold, palladium and bismuth, from the viewpoint of suppressing diffusion of silver and consequently increasing moisture resistance. preferable. The total of other metals is preferably 0.2 to 3.0% by mass in the metal layer 104 (100% by mass) in order to make the specific resistance 10.0 μΩcm or less, particularly 5 μΩcm or less. .5% by mass is more preferable

  The total film thickness of all the metal layers 104 is preferably 25 to 60 nm, more preferably 25 to 50 nm, for example, when the target surface resistance of the obtained conductive film 40 is 1.5Ω / □. Preferably, when the surface resistance target is 0.9Ω / □, 35 to 80 nm is preferable, and 35 to 70 nm is more preferable. As for the thickness of each metal layer 104, the total thickness is appropriately distributed according to the number of metal layers 104.

  Examples of the method for forming the conductive film 100 (the oxide layer 102 and the metal layer 104) on the film substrate 42 include a sputtering method, a vacuum deposition method, an ion plating method, and a chemical vapor deposition method. The sputtering method is preferable because of its good quality and stability of characteristics. Examples of the sputtering method include a pulse sputtering method and an AC sputtering method.

The formation of the conductive film 100 by sputtering can be performed as follows, for example.
(I) While introducing argon gas mixed with oxygen gas, pulse sputtering is performed using a target containing a metal oxide to form the oxide layer 102 on the surface of the film substrate 42.
(Ii) While introducing argon gas, pulse sputtering is performed using a silver target or a silver alloy target to form the metal layer 104 on the surface of the oxide layer 102.
The operations (i) and (ii) are repeated, and finally the oxide layer 102 is formed by the same method as in (i), thereby forming the conductive film 100 having a multilayer structure.

The target can be produced by sintering a metal oxide high-purity (usually 99.9%) powder by hot pressing, HIP (hot isostatic pressing), or normal pressure firing.
A target having a porosity of 5.0% or less and a specific resistance of less than 1 Ωcm is preferable.

  In the conductive film 100, the protective film 106 may be provided on the surface of the oxide layer 102 farthest from the film base material 42. The protective film 106 is a layer that protects the oxide layer 102 and the metal layer 104 from moisture. In addition, this is a layer that protects the oxide layer 102 farthest from the film substrate 42 from a pressure-sensitive adhesive (particularly an alkaline pressure-sensitive adhesive) when the functional film 60 is bonded.

Examples of the protective film 106 include oxide films and nitride films of metals such as tin, indium, titanium, and silicon, and an indium-tin oxide (ITO) film is preferable.
2-30 nm is preferable and, as for the film thickness of the protective film 106, 3-20 nm is more preferable.

(Functional film)
Examples of the functional film 60 include an antireflection film, a colored film, a moisture-proof film, a scattering prevention film, a near-infrared shielding film, and a near-infrared absorbing film. A known film may be used as the functional film. Two or more functional films may be laminated. A single functional film may have a plurality of functions.

(electrode)
Examples of the electrode 70 include a silver paste containing silver and glass frit, a printing layer formed by printing a copper paste containing copper and glass frit on the substrate 20; an aluminum tape, and the like.

(Adhesive layer)
Examples of the pressure-sensitive adhesive for the pressure-sensitive adhesive layers 30 and 50 include commercially available pressure-sensitive adhesives. For example, acrylic ester copolymer, polyvinyl chloride, epoxy resin, polyurethane, vinyl acetate copolymer, styrene-acrylic copolymer, polyester, polyamide, polyolefin, styrene-butadiene copolymer rubber, butyl rubber, silicone resin, etc. The pressure-sensitive adhesive is mentioned. Among these, an acrylic pressure-sensitive adhesive is particularly preferable because good moisture resistance can be obtained. The pressure-sensitive adhesive layers 30 and 50 may contain additives such as ultraviolet absorbers. 10-100 micrometers is preferable and, as for the thickness of the adhesive layers 30 and 50, 20-60 micrometers is more preferable. When the thickness of the pressure-sensitive adhesive layer is in the above range, sufficient adhesion can be obtained.
Examples of the conductive pressure-sensitive adhesive layer 80 include a pressure-sensitive adhesive containing one or more selected from fillers such as nickel powder, silver powder, copper powder, and carbon powder and a conductive polymer. Examples of the type of the pressure-sensitive adhesive include pressure-sensitive adhesives that can be used in the pressure-sensitive adhesive layers 30 and 50. Among these, an acrylic or silicone resin pressure-sensitive adhesive containing a nickel powder filler is particularly preferable because good heat resistance is obtained. 10-100 micrometers is preferable and, as for the thickness of the electroconductive adhesive layer 80, 20-60 micrometers is more preferable.

  In the protective plate 10 described above, the peripheral edge portion of the conductive film 40 is folded back at the end surface 22 of the substrate 20 and attached to the back surface of the substrate 20, so that without using a conductive tape, The conductive film 40 can be electrically connected to the ground terminal of the plasma display device. For this reason, compared with the case where an electroconductive tape is used, contact resistance becomes small and can fully exhibit electromagnetic wave shielding performance. Further, since it is not necessary to use a conductive tape, the cost is low. Further, since the conductive layer 44 is formed on the film base material 42, it is not necessary to prepare two substrates as in the case of only a conventional metal mesh, and the cost is low. Moreover, since the conductive layer 44 is formed on the film base material 42, disconnection hardly occurs and the electromagnetic wave shielding performance is not easily lowered.

<Method for manufacturing protective plate for plasma display>
The method for producing a protective plate according to the present invention includes a step of providing a conductive film on a substrate such that a part or all of the peripheral edge of the conductive film protrudes outward from the end surface of the substrate, and from the end surface of the substrate. A step of folding back the peripheral portion of the conductive film protruding outward from the end surface of the substrate; and a step of attaching the peripheral portion of the conductive film folded back at the end surface of the substrate to the back surface of the substrate. Is the method.

Hereinafter, an example in which the conductive layer is a metal mesh is shown.
First, as shown in FIGS. 7 and 8, the conductive film 40 is placed on the substrate 20, the film base 42 is on the substrate 20 side, and the entire periphery of the conductive film 40 is the end face of the substrate 20. It sticks through an adhesive layer (not shown) so that it may protrude outside 22. At this time, a part of the non-mesh portion 94 formed on the peripheral portion of the metal mesh 90 of the conductive film 40 is left on the peripheral portion of the surface of the substrate 20.

Next, as shown in FIG. 9, the functional film 60 is placed on the conductive film 40 so that the peripheral portion of the functional film 60 does not protrude outside the end face 22 of the substrate 20. Paste through. In FIG. 9, the size of the functional film 60 is larger than the mesh portion 92 of the metal mesh. As for the relationship between the size of the mesh portion 92 and the size of the functional film 60, the mesh portion 92 may be larger, contrary to FIG. 9, and the size of the mesh portion 92 and the functional film 60 is the same. May be.
Then, if necessary, as shown in FIG. 10, the second functional film 62 is placed on the functional film 60, and the peripheral portion of the second functional film 62 protrudes outside the end surface 22 of the substrate 20. It sticks through an adhesive layer (illustration abbreviation) so that there may not be.

Next, as shown in FIG. 11, the peripheral portion of the conductive film 40 that protrudes outward from the end surface 22 of the substrate 20 is folded back at the end surface 22 of the substrate 20.
Next, the peripheral portion of the conductive film 40 folded back at the end surface 22 of the substrate 20 is attached to the back surface of the substrate 20 to obtain the protective plate 10.

In the case where the conductive layer is a conductive film and the conductive film is attached on the substrate so that the film base is on the substrate side, the conductive film suppresses oxidation of the metal layer included in the conductive film. In order to ensure the conduction even if cracks occur, the conductive film covers the conductive film of the folded conductive film from the peripheral part on the front side of the substrate to the peripheral part on the back side of the substrate. A tape may be attached.
In the case where the conductive layer is a conductive film, the conductive film is preferably provided over the substrate so that the conductive layer is on the substrate side. Next, an example of the manufacturing method of the plasma display protective plate in this case will be described.
First, an electrode made of a silver paste is formed by printing on the periphery of the back surface of the substrate, that is, the surface opposite to the surface on which the conductive film is provided. Next, the conductive film is placed on the surface of the substrate opposite to the surface on which the electrodes are formed, and the entire periphery of the conductive film protrudes outside the end surface of the substrate so that the conductive layer is on the substrate side. As above, it sticks through an adhesive layer. Next, the functional film is pasted on the surface of the pasted conductive film via an adhesive layer so that the peripheral edge of the functional film does not protrude beyond the end face of the substrate. Then, if necessary, the second functional film is attached via an adhesive layer so that the peripheral portion of the second functional film does not protrude outside the end face of the substrate. Next, the peripheral edge portion of the conductive film that protrudes outward from the end surface of the substrate is folded back at the end surface of the substrate. Next, the protective film is obtained by attaching the peripheral portion of the conductive film folded at the end surface of the substrate 20 to the back surface of the substrate. At this time, at least a part of the electrode formed on the peripheral edge of the back surface of the substrate overlaps with the peripheral edge of the conductive film and is electrically connected. Further, at least a part of the electrode includes a portion that does not overlap with the conductive film.

  In the manufacturing method of the protection plate 10 described above, since it is not necessary to use a conductive tape, the protection plate 10 capable of directly conducting the conductive film 40 and the ground terminal of the plasma display device is obtained. That is, the protective plate 10 having excellent electromagnetic wave shielding performance is obtained. Moreover, since it is not necessary to use a conductive tape, the protective plate 10 can be manufactured with high productivity and at low cost. In addition, since the conductive layer 44 is formed on the film substrate 42, the conductive film 40 can be easily handled. For this reason, the protective plate 10 can be manufactured with high productivity. Moreover, since the conductive layer 44 is formed on the film base material, disconnection hardly occurs when the conductive film is folded back, and the electromagnetic wave shielding performance is not easily lowered.

<Plasma display device>
The plasma display device of the present invention includes a PDP and the protective plate of the present invention disposed in front of the PDP, and the substrate of the protective plate is located on the PDP side with respect to the conductive film.
When the conductive layer is a conductive film, when the substrate of the protective plate is positioned on the PDP side with respect to the conductive film, the reflection can be reduced in a wider wavelength range than when the conductive film is on the PDP side. . That is, the color of the reflected light can be reduced.

FIG. 12 is a schematic cross-sectional view showing a state in which the protective plate of the present invention is attached to the casing of the plasma display device.
By attaching the protective plate 10 to the casing 112 of the plasma display device, a seal is formed between the conductive film 40 and the ground terminal 114 made of an aluminum bracket, which is installed on the PDP (not shown) side of the protective plate 10. Conduction can be established through the bonding gasket 116.

  In the plasma display device of the present invention described above, since the protective plate of the present invention having excellent electromagnetic wave shielding performance is disposed in front of the PDP, electromagnetic waves emitted from the front surface of the PDP are sufficiently shielded. The

[Example 1]
From the following conductive film having a non-mesh portion, cut to a size of 145 mm length and 100 mm width so that the width of the non-mesh portion is 90 mm, and the mesh portion 92 on the film substrate 42 as shown in FIG. The test conductive film 40 provided with the non-mesh portion 94 was obtained.
Conductive film: A copper foil mesh (line width 12 μm, thickness 10 μm, mesh pitch 250 μm) is provided on one surface of a PET film substrate having a thickness of 100 μm via an adhesive layer. A mesh film having a pressure-sensitive adhesive layer on the other surface (Dai Nippon Printing Co., Ltd., trade name: EMI sheet for PDP).

  As shown in FIG. 13, the adhesive layer (not shown) side of the conductive film 40 is placed on the glass substrate 20 (100 mm × 100 mm, thickness 1.8 mm), and the non-mesh portion 94 is the end surface of the substrate 20. It stuck so that 20 mm might protrude outside. As shown in FIG. 14, the non-mesh portion 94 of the protruding conductive film 40 was folded along the end surface of the substrate 20 and attached to the back surface of the substrate 20. The resistance between point A (30 mm from the end face of the substrate 20) and point B (10 mm from the end face of the substrate 20) in FIG. 14 was measured three times using a tester (manufactured by Hioki Electric Co., Ltd., trade name: HIOKI 3541 REISTANCE HiTESTER). . The results are shown in Table 1.

[Example 2]
From the mesh film (Dai Nippon Printing Co., Ltd., trade name: PDP EMI sheet), a non-mesh portion having a width of 100 mm is cut into a size of 100 mm in length and 100 mm in width, and as shown in FIG. A test conductive film 40 in which a mesh portion 92 and a non-mesh portion 94 were provided on the base material 42 was obtained.
As shown in FIG. 15, the adhesive layer (not shown) side of the conductive film 40 on the glass substrate 20 (100 mm × 100 mm, thickness 1.8 mm), the end face of the substrate 20 and the surface of the conductive film 40. Affixed to align.

  As shown in FIG. 16, a conductive tape 120 having a width of 20 mm (produced by Teraoka Seisakusho, aluminum tape with conductive adhesive, product number 8303) was attached to the end of the non-mesh portion 94 so as to overlap 5 mm, and the protruding conductive The adhesive tape 120 was folded along the end surface of the substrate 20 and attached to the back surface of the substrate 20. Resistance between a point C (30 mm from the end face of the substrate 20) and a point D (10 mm from the end face of the substrate 20) in FIG. 16 was measured three times using the tester. The results are shown in Table 1.

  From the results in Table 1, it was found that Example 1 had a lower resistance than Example 2. Therefore, it was confirmed that the protective plate having the structure of Example 1 can shield electromagnetic waves more effectively than the protective plate having the structure of Example 2.

[Example 3]
The following conductive film having a non-mesh portion was prepared.
Conductive film: A copper foil mesh (line width 12 μm, thickness 10 μm, mesh pitch 300 μm) is provided on one surface of a PET film substrate having a thickness of 125 μm via an adhesive layer. Double-sided blackened mesh film (manufactured by Kyodo Printing Co., Ltd., trade name: EM FILM) provided with an adhesive layer on the other surface.

  As shown in FIG. 7, the conductive film 40 was cut into a 1188 mm × 702 mm rectangle, and the four corners were cut almost at an angle of 50 ° so that the length of the cut was 30 mm. As shown in FIG. 7 and FIG. 8, the adhesive layer (not shown) side of the conductive film 40 is made of a glass substrate 20 whose end face is chamfered (Asahi Glass Co., Ltd., 1164 mm × 678 mm, thickness 3.2 mm). The peripheral edge (4 sides) of the conductive film 40 was pasted on the chamfered radius R1.6 mm) so as to protrude by 12 mm.

A functional film 60 (colored film) provided with a colored layer having a transmittance of 42% on a PET film (thickness 100 μm, manufactured by Toyobo Co., Ltd., trade name: A4300) was cut into 1160 mm × 674 mm, which is shown in FIG. As shown in FIG. 2, the film was affixed on the conductive film 40 via an adhesive layer (not shown).
The second functional film 62 (Nippon Yushi Co., Ltd., antireflection film, product name: Realic) was cut to 1160 mm × 674 mm, and this was cut onto the functional film 60 as shown in FIG. Abbreviated).

  As shown in FIG. 11, the peripheral portion of the conductive film 40 that protrudes outward from the end surface of the substrate 20 is folded back at the end surface of the substrate 20, and then the peripheral portion of the conductive film 40 that is folded back is attached to the back surface of the substrate 20. I attached. The width of the conductive film 40 on the back surface of the substrate 20, that is, the distance from the end surface of the peripheral portion of the conductive film 40 to the end surface of the substrate 20 was about 10 mm. A protective plate 10 was obtained as described above.

  The protective plate 10 was stored at room temperature for 2 days, and then placed in a constant temperature and humidity chamber (manufactured by ESPEC, apparatus name: TBL-2HW-2PA) at 60 ° C. and 90 RH%. When the protective plate 10 was observed after being left for 48 hours, the folded portion of the conductive film 40 was not peeled off from the substrate 20, and the conductive film 40 on the surface side of the substrate 20 and the conductivity on the back surface side of the substrate 20 were not observed. The conduction with the conductive film 40 was not cut off.

  The protective plate of the present invention is useful as a protective plate for a plasma display device because of its excellent electromagnetic shielding performance and low cost.

It is a schematic sectional drawing which shows an example of the protective plate for plasma displays of this invention. It is a schematic sectional drawing which shows the other example of the protective plate for plasma displays of this invention. It is a schematic sectional drawing which shows an example of the board | substrate by which the end surface was thread chamfered. It is a schematic sectional drawing which shows an example of the board | substrate by which the end surface was chamfered. It is a front view which shows an example of a metal mesh. It is a schematic sectional drawing which shows an example of the electroconductive film which has an electrically conductive film. It is a front view which shows a mode that the electroconductive film which has a metal mesh was affixed on the board | substrate. It is a schematic sectional drawing which shows 1 process of the manufacturing method of the protection plate for plasma displays of this invention. It is a schematic sectional drawing which shows 1 process of the manufacturing method of the protection plate for plasma displays of this invention. It is a schematic sectional drawing which shows 1 process of the manufacturing method of the protection plate for plasma displays of this invention. It is a schematic sectional drawing which shows 1 process of the manufacturing method of the protection plate for plasma displays of this invention. It is a schematic sectional drawing which shows a mode that the protective plate for plasma displays of this invention was attached to the housing | casing of a plasma display apparatus. It is a schematic sectional drawing for demonstrating the evaluation method in Example 1 of an Example. It is a schematic sectional drawing for demonstrating the evaluation method in Example 1 of an Example. It is a schematic sectional drawing for demonstrating the evaluation method in Example 2 of an Example. It is a schematic sectional drawing for demonstrating the evaluation method in Example 2 of an Example.

Explanation of symbols

10 Protection plate (Protection plate for plasma display)
12 Protection plate (Protection plate for plasma display)
20 Substrate 22 End face 40 Conductive film 42 Film base 44 Conductive layer 60 Functional film 62 Second functional film (functional film)
70 electrode 90 metal mesh (conductive layer)
94 Non-mesh part 100 Conductive film (conductive layer)
102 Oxide layer 104 Metal layer

Claims (10)

A substrate and a conductive film provided on the substrate;
Part or all of the peripheral edge of the conductive film is folded at the end surface of the substrate, and is attached to the surface of the substrate opposite to the surface on which the conductive film is provided. Protective plate.   The protective plate for a plasma display according to claim 1, wherein the conductive film has a film base and a conductive layer provided on the film base.   The protective plate for a plasma display according to claim 2, wherein the conductive film is provided such that the film base is on the substrate side.   The protective plate for a plasma display according to claim 2 or 3, wherein the conductive layer is a metal mesh.   The protective plate for a plasma display according to claim 4, wherein a peripheral portion of the metal mesh is a non-mesh portion where no mesh is formed.   In the conductive layer, an oxide layer and a metal layer are alternately (2n + 1) layers [where n is an integer of 1 to 8. The protective plate for plasma display according to claim 2 or 3, wherein the protective plate is a laminated conductive film.   The protective plate for a plasma display according to claim 1, wherein an end surface of the substrate is chamfered.   Furthermore, the protective plate for plasma displays in any one of Claims 1-7 which has a functional film provided on the said electroconductive film. Providing a conductive film on a substrate such that a part or all of the peripheral edge of the conductive film protrudes outside the end surface of the substrate;
A step of folding back the peripheral edge of the conductive film that protrudes outside the end surface of the substrate at the end surface of the substrate;
A process for affixing a peripheral portion of the conductive film folded at an end surface of the substrate to a surface of the substrate opposite to the surface on which the conductive film is provided. Method. A plasma display panel;
The protective plate for plasma display according to any one of claims 1 to 8, which is disposed in front of the plasma display panel,
The plasma display device, wherein the substrate of the protective plate for plasma display is located closer to the plasma display panel than the conductive film.

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