JP4249426B2 - Electromagnetic wave shielding member - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an electromagnetic wave shielding member having an electromagnetic wave shielding effect such as a window, a PDP, and a CRT, and a method for manufacturing the same, and more particularly, two or more lines made of electromagnetic wave shielding ink and having a line width L such as a mesh. The present invention relates to an electromagnetic wave shielding member having an electromagnetic wave shielding property in which intersecting patterns are arranged on a surface of a base material, and a method for producing the same.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, electronic devices that generate electromagnetic waves that are directly used by humans, such as display electron tubes for plasma displays, can suppress the electromagnetic wave emission within the standard in consideration of the harmful effects of electromagnetic waves on the human body. It is requested.
Further, in a plasma display panel (hereinafter also referred to as PDP), since light emission uses plasma discharge, an unnecessary electromagnetic wave having a frequency band of 30 MHz to 130 MHz is leaked to the outside. Etc.) is required to suppress electromagnetic waves as much as possible.
In response to these requirements, in general, an electromagnetic shield that covers an outer periphery of an electronic device that generates an electromagnetic wave with an appropriate conductive member in order to remove or attenuate the electromagnetic wave that flows out from the electronic device that generates the electromagnetic wave. Is taken.
In a display panel such as a plasma display panel, it is common to provide an electromagnetic shielding plate with good transparency on the front surface of the display.
[0003]
The electromagnetic shielding plate has a relatively simple basic structure itself. A transparent conductive film such as an indium-tin oxide film (ITO film) is deposited on a transparent glass or plastic substrate surface by vapor deposition or sputtering. A metal thin film is formed on the entire surface by electroless plating or vapor deposition on a transparent glass or plastic substrate surface that has been formed, or on a transparent glass or plastic substrate surface that has been bonded with an appropriate metal screen such as a wire mesh. In addition, there are known those obtained by processing the metal thin film by a photolithography method or the like to provide a mesh made of a fine metal thin film.
[0004]
The electromagnetic shielding plate in which an ITO film is formed on a transparent substrate is excellent in terms of transparency, and generally has a light transmittance of around 90%, and a uniform film can be formed on the entire surface of the substrate. When used in a display or the like, there is no concern about the occurrence of moire or the like due to the electromagnetic shielding plate.
However, in an electromagnetic wave shielding plate in which an ITO film is formed on a transparent substrate, a technique such as vapor deposition or sputtering is used to form the ITO film, so that the manufacturing apparatus is expensive and the productivity is generally also high. Since it is inferior, there exists a problem that the price of the electromagnetic wave shielding board itself as a product becomes expensive.
Furthermore, in the electromagnetic wave shielding plate in which the ITO film is formed on the transparent substrate, the electromagnetic wave emission is relatively weak because the conductivity is inferior by one digit or more compared with the electromagnetic wave shielding plate in which the mesh made of the metal thin film is formed. Although effective against the object, when used on a strong object, the shielding function becomes insufficient, leakage electromagnetic waves are emitted, and the standard value may not be satisfied. is there.
In the electromagnetic wave shielding plate in which the ITO film is formed on the transparent substrate, in order to increase the conductivity, if the thickness of the ITO film is increased, the conductivity is improved to some extent, but in this case, the transparency is remarkably lowered. The problem occurs.
In addition, there is a problem that the manufacturing price becomes higher by making it thicker.
[0005]
Also, when using an electromagnetic shielding plate with a metal screen attached to a transparent glass or plastic substrate surface, or when attaching an appropriate metal screen such as a wire mesh directly to the display surface, it is simple and inexpensive. However, the transmissivity of an effective mesh (100-200 mesh) metal screen is 50% or less, which has a serious disadvantage that the display becomes extremely dark.
[0006]
In addition, a transparent glass or plastic substrate surface with a metal thin film mesh is processed into an outer shape by etching using a photolithographic method, enabling fine processing and a high aperture ratio (high transmittance) mesh. Since the mesh is formed of a metal thin film, the conductivity is very high compared to the ITO film and the like, and there is an advantage that powerful electromagnetic wave emission can be shielded. .
However, the manufacturing process is complicated and complicated, its productivity is low, and the problem of high production costs cannot be avoided.
[0007]
Although it is conceivable to form a mesh by screen printing using conductive ink or magnetic ink, there is a limit to thinning, and it is difficult to make an endless pattern, and there is a problem in printing on the web.
Formation of a mesh using conductive ink or magnetic ink by gravure printing cannot perform fine line printing.
[0008]
As described above, each electromagnetic wave shielding plate has advantages and disadvantages, and is selected and used according to the application.
Under such circumstances, an electromagnetic shielding plate used for electromagnetic shielding placed on the front of a display panel such as a PDP can be finely meshed in terms of quality, can be mass-produced, and can be manufactured at low cost. There is a need for a method.
[0009]
Here, an example of an electromagnetic wave shielding plate in which a mesh made of a metal thin film or the like is formed on a transparent glass or plastic substrate surface is shown in FIG. 4 and will be briefly described.
4A is a plan view of the electromagnetic wave shielding plate, FIG. 4B is a cross-sectional view taken along D1-D2 of FIG. 4A, and FIG. 4C is an enlarged view of a part of the mesh portion.
4A and 4C show the X direction and the Y direction for clarifying the positional relationship and the mesh shape.
The electromagnetic wave shielding plate shown in FIG. 4 is an electromagnetic wave shielding electromagnetic wave shielding plate 40 that is used by being placed on the front surface of a display such as a PDP, and has a grounding frame portion 42 and a mesh portion 41 formed on one surface of a transparent substrate 43. The grounding frame portion 42 is formed of the same metal thin film 44 as the mesh portion on the outer periphery of the mesh portion 41 so as to surround the screen area of the display when used on the front surface of the display.
The mesh portion 41 has a plurality of lines 46 provided in the Y and X directions parallel to each other at predetermined pitches Px and Py, respectively, as shown in FIG. And the line 45 group.
The mesh shape is not limited to that shown in FIG.
In addition, an anti-reflection layer, a near-infrared cut layer, and the like are usually further provided on the electromagnetic wave shielding plate shown in FIG. 4 in an electromagnetic wave shielding plate used on the front surface of a display panel such as a plasma display panel (PDP). ing.
[0010]
[Problems to be solved by the invention]
For this reason, an electromagnetic wave shielding plate having an electromagnetic wave shielding mesh made of a metal thin film or the like as shown in FIG. 4 provided on a transparent substrate is required in a large quantity in terms of transparency and electromagnetic wave shielding properties. It has become.
The present invention corresponds to this, and specifically, it was produced by a flexographic printing method capable of responding quantitatively and costly from the viewpoint of productivity and quality. An object of the present invention is to provide an electromagnetic shielding member provided with a mesh made of ink having an electromagnetic shielding effect.
[Means for Solving the Problems]
Member for electromagnetic shielding of the present invention, while conveying so as to sandwich the window Ebb-like film substrate between the plate cylinder and the impression cylinder, the electromagnetic wave shielding ink transcribed from the ink supply roll of the anilox slow Le on the plate cylinder A mesh made of electromagnetic wave shielding ink by a flexographic printing method using a CTP (Computer To Plate) plate on the plate cylinder in a continuous transfer form from the plate cylinder onto one surface of a film substrate. An electromagnetic shielding member having electromagnetic shielding properties in which a pattern in which two or more lines having a line width L intersect is disposed on one surface of the film substrate is a line intersection where the lines having the line width L intersect. it is characterized in that the thickness of the portion is 1.2 to 3 times the line section. In the above, the area of the line intersection where the lines of the line width L intersect is 2 to 30 times L × L. Here, the film thickness of the line intersection part is represented by the film thickness of the thick part of the intersection part, and the film thickness of the line part is represented by the film thickness of the line part in the middle of the intersection part. Also, the line intersection part is usually thick, and in the plan view, it is represented by a substantially rectangular part surrounded by extending the outer side connecting each line adjacent to the intersection part, so the area of this substantially rectangular part Is the area of the intersection.
[0012]
[Action]
The electromagnetic wave shielding member of the present invention is produced by a flexographic printing method capable of responding quantitatively and costly in terms of productivity and quality by adopting such a configuration, and is a film substrate. The provision of an electromagnetic shielding member in which a mesh having an electromagnetic shielding effect is disposed on one surface can be provided in terms of quality.
As a result, an electromagnetic wave shielding plate having good transparency and electromagnetic wave shielding properties for a display such as a PDP as shown in FIG. 4 can be provided in a large amount at an early stage.
Specifically, the electromagnetic wave shielding ink transferred from the ink supply roll such as an anilox roll to the plate cylinder while transporting the web-shaped film base material between the plate cylinder and the impression cylinder, from the plate cylinder, By a flexographic printing method using a CTP (Computer To Plate) plate in a continuous transfer formation on one surface of a film substrate and a plate cylinder, two or more meshes made of electromagnetic wave shielding ink or the like are used. An electromagnetic shielding member having electromagnetic shielding properties, in which a pattern in which lines having a line width L intersect is arranged on one surface of a film substrate, and the film thickness of the line intersection is 1.2 times that of the line. This is achieved by the fact that it is ˜3 times and that the area of the intersection part of the line having the line width L is 2 times to 30 times L × L.
Specifically, by using flexographic printing using a CTP (Computer To Plate) plate for the plate cylinder, the entire pattern can be formed into a thin film, and only the intersection can be thickened, and the thick portion functions as a spacer. Thus, blocking can be smoothly prevented, and the film substrate can be smoothly wound and unwound, whereby thinning can be achieved and mass production is possible.
Moreover, favorable electroconductivity can be acquired by thickening the film thickness of a line intersection part thicker than a line part.
The term “blocking” refers to blocking of the film base material when the film base material is wound on a roll. This means that the film base material is not wrinkled or peeled off easily.
[0013]
Embodiment
Embodiments of the present invention will be described with reference to the drawings.
1A is a plan view showing an example of an embodiment of a member for electromagnetic wave shielding according to the present invention, FIG. 1A 1 is an enlarged view of a portion A 1 in FIG. FIG. 1B is a cross-sectional view taken along line A2-A3 in FIG. 1A, FIG. 1C is a view showing an intersection of mesh portions, and FIG. 1D is a cross-sectional view taken along line A4-A5 in FIG. FIG. 2 is a view showing an example of an apparatus for performing a flexographic printing method, and FIGS. 3A to 3E are cross-sectional views of a manufacturing process of a CTP plate, and FIG. 3 (c1) to 3 (e1) are process cross-sectional views of a conventional flexographic printing plate.
1-3, 10 is an electromagnetic wave shielding member, 11 is a mesh part, 12 is a grounding frame part, 13 is a film substrate, 14 is an electromagnetic wave shielding ink, 15 is a line (in the X direction), 16 is ( (Y direction) line, 17 is an intersection point, 21 is an ink supply roll, 22 is a plate cylinder, 23 is an impression cylinder, 24 is an ink reservoir, 25 is a squeegee, 26 is a plate (also referred to as a flexo resin plate), 27 Is a film substrate, 28 is an (electromagnetic shielding) ink, 29 is a guide roll, 31 is a base substrate, 32 is a UV curable resin, 32a is a cured portion, and 32b is a UV curable resin remaining after development. (Also referred to as insolubilized portion), 32c is a UV curable resin after post-exposure, 33 is a mask layer, 34 is UV light, 36 is a masking film (also referred to as a film pattern), 37 is a vacuum sheet, and 38 is a convex portion. .
Px and Py represent the x-direction pitch and the y-direction pitch of the line, respectively.
Hereinafter, the electromagnetic wave shielding member of this example will be described with reference to FIG.
The electromagnetic wave shielding member of this example is an electromagnetic wave shielding member for an electromagnetic wave shielding plate used on the front surface of a display panel such as a PDP. The X direction made of the electromagnetic wave shielding ink 14 is formed on one surface of the transparent film substrate 13. A mesh portion 11 made of a mesh pattern in which a line having a line width L and a line having a line width L in the Y direction intersect with each other, and a grounding frame portion made of electromagnetic shielding ink 14 is provided around the mesh portion 11 The arrangement of the mesh portion 11 and the grounding frame portion 12 made of electromagnetic wave shielding ink on one surface of the film base 13 is carried so that the web-like film base is sandwiched between the plate cylinder and the impression cylinder. On the other hand, the electromagnetic wave shielding ink transferred from the ink supply roll such as an anilox roll to the plate cylinder is continuously transferred from the plate cylinder onto one surface of the film substrate. In a manner, and, on the plate cylinder CTP (Computer To
This is performed by a flexographic printing method using a plate plate.
The film thickness of the line intersection 17 is in the range of 1.2 to 2 times the height of the lines 15 and 16, and the area of the intersection 17 of the line 17 having the line width L is 2 to 30 times L × L. This is the range.
Here, the film thickness 1 of the intersection 17 shown in FIG. 1D and the film thickness h2 of the line 15 (or 16) and the ratio h1 / h2 are in the range of 1.2 to 3 times.
h is the difference between the film thickness 1 of the intersection 17 and the film thickness of the line 15 (or 16).
In addition, the intersection area is an abbreviation that is surrounded by extending the outer side 18 that connects adjacent lines of the intersection in the plan view, as indicated by the hatched portion in FIG. The area S of the rectangular part 19 is said.
Here, the ratio (S / (L × L)) between the area S and L × L in the plan view of the rectangular portion 19 is in the range of 2 to 30 times.
[0014]
Specific examples of the transparent film substrate 13 include a triacetyl cellulose film, a diacetyl cellulose film, an acetate butyrate cellulose film, a polyether sulfone film, a polyacrylic resin, a polyurethane resin film, a polyester film, and a polycarbonate film. Polysulfone film, polyether film, trimethylpentene film, polyetherketone film, (meth) acrylonitrile film, etc. can be used, and in particular, biaxially stretched polyester is suitable in terms of excellent transparency and durability. .
The thickness is preferably about 200 μm, but is not limited thereto.
The light transmittance of the transparent film is ideally 100%, but it is preferable to select a light transmittance of 80% or more.
[0015]
As the electromagnetic wave shielding ink 14, conductive ink or magnetic ink is used.
The conductive ink exhibits an electromagnetic shielding effect mainly by reflection of electromagnetic waves.
As the conductive ink, the volume resistivity of the dry film is preferably 10 ⁻³ Ω · cm to 10 ⁻⁶ Ω · cm, more preferably about 10 ⁻⁴ Ω · cm to 10 ⁻⁵ Ω · cm. In addition, a conductive powder dispersed in a vehicle and used as an ink is used.
As such a conductive powder, for example, silver, gold, platinum, copper, aluminum, nickel, graphite, tin or the like is used alone or in combination.
Further, as the binder resin in the vehicle, for example, an acrylic resin, a urethane resin, a polyester resin, or the like is used alone or in combination.
In addition, the shape of the conductive powder is more preferable in terms of better conductivity than a sphere or an elliptical sphere.
The conductive powder may be doped with other metals or metal oxides in order to improve transparency.
For example, ITO (indium-tin oxide).
On the other hand, magnetic ink has an electromagnetic wave shielding effect mainly by absorption of electromagnetic waves.
As the magnetic ink, an ink obtained by dispersing magnetic powder in a vehicle is used.
As such magnetic powder, for example, a powder having an average particle diameter of about 1 μm to 10 μm such as a soft magnetic material such as ferrite such as Mn—Zn ferrite, soft iron, silicon steel, carbonyl iron, sendust iron, and permalloy is used.
As the binder resin in the vehicle, the same one as in the case of the conductive ink is used.
[0016]
The flexographic printing method here will be briefly described with reference to FIG.
The electromagnetic wave shielding ink 28 transferred from the ink supply roll 21 such as an anilox roll to the plate cylinder 22 is transferred from the plate cylinder 22 while the web-shaped film substrate is conveyed while being sandwiched between the 27 plate cylinder 22 and the impression cylinder 23. The mesh portion 11 made of the electromagnetic wave shielding ink 14 shown in FIG. 1 (corresponding to the electromagnetic wave shielding ink 28 in FIG. 2) is formed by continuously transferring and forming on one surface of the film substrate 27. The grounding frame is transferred and formed on one surface of the film base material 27 (corresponding to 13 in FIG. 1) from the plate cylinder 22 side.
The form shown in FIG. 2 is an example of a flexographic printing apparatus and is not limited to this.
[0017]
Next, a method for producing a CTP (Computer To Plate) plate will be described based on FIG. 3 while comparing with a method for producing a conventional flexographic printing plate.
3 (a) to 3 (e) are cross-sectional views of a CTP plate manufacturing process, and FIGS. 3 (a1) and 3 (c1) to 3 (e1) are cross-sectional views of a conventional flexographic printing plate. .
First, a UV curable resin 32 for making a plate and a mask layer 33 for forming a mask are formed on one surface of a base substrate 31 such as PET (polyethylene terephthalate), and the entire surface is exposed from the base substrate 31 side ( Back exposure). (Fig. 3 (a))
Thereby, the UV curable resin 32 on the base substrate 31 side is cured and insolubilized in a developing solution to be developed later.
Next, a predetermined region of the mask layer 33 is irradiated with laser light to open the mask layer 33, and a mask made of the mask layer 33 is manufactured. (Fig. 3 (b))
As a result, the mask made of the mask layer is laminated on the surface of the UV curable resin 32.
Next, the UV curable resin 32 is exposed through a mask made of the mask layer 33 on the prepared UV curable resin (FIG. 3C), and further developed. (Fig. 3 (d))
In the production of a conventional flexographic plate, a mask layer is not provided, and exposure (referred to as back exposure) is performed on the entire surface from the base substrate 31 side (FIG. 3 (a1)), and then disposed on the base substrate 31. The masking film 36 was held on the UV curable resin 32 with a vacuum sheet 37, and the two were exposed through the masking film 36 while being in vacuum contact with each other (FIG. 3 (c1)), and further developed. (Fig. 3 (d1))
The exposure through the mask composed of the mask layer 33 laminated on the surface of the UV curable resin 32 is less affected by light scattering than the exposure in the production of a conventional flexographic plate (FIG. 3 (b1)). Since the exposed portion is in contact with air, the convex portion 38, which is an insolubilized portion after development, is thinner than in the production of a conventional flexographic plate.
Thereafter, the entire insolubilized portion 32b is irradiated with UV light 34.
The same applies to the production of a conventional flexographic plate.
Here, the plate shown in FIG. 3 (e) produced by the steps shown in FIGS. 3 (a) to 3 (e) is called a CTP (Computer To Plate) plate, which is shown in FIG. 3 (e1). Compared to the flexo version of, it can be made thinner.
[0018]
In this example, the film thickness of the line intersection 17 is 1.2 to 3 times the height of the lines 15 and 16, and the area of the intersection 17 of the line having the line width L is 2 to 30 times L × L. However, let me briefly explain why.
The ratio h1 / h2 of the thickness h1 of the intersection 17 shown in FIG. 1D to the thickness h2 of the line 15 (or 16) prevents blocking in the flexographic printing method using the apparatus shown in FIG. It is better from the aspect, but if the ratio h1 / h2 is smaller than 1.2, there is no effect of preventing blocking, and if the ratio h1 / h2 is larger than 3, it is likely to be lost, and eventually the ratio h1 / h2 is set to 1. It is preferable to set it as 2-3.
Further, when the ratio of the area S to L × L (S / (L × L)) in the plan view of the rectangular portion 19 is smaller than 2, the ink transfer amount becomes small, and from the aspect of the aperture ratio of the mesh portion 11, 30 is preferable. After all, the ratio (S / (L × L)) of the area S to L × L in the plan view of the rectangular portion 19 is preferably in the range of 2 to 30.
[0019]
【Example】
The following examples further illustrate the present invention.
The embodiment uses the CTP plate in the flexographic printing apparatus shown in FIG. 2, and each electromagnetic shielding member 10 having a mesh portion with a pitch of 380 mm with respect to a line width of 30 μm of the design dimension in FIG. These were produced by flexographic printing.
The electromagnetic shielding ink 28 is transferred from one side of the plate cylinder 22 onto the one side of the film substrate 27 made of PET at a printing speed of 50 m / min while pressing the impression cylinder 23 on the flexographic resin plate 26 moderately. 11) etc. of FIG. 1 were formed.
An anilox roll of 600 lines / inch was used as the ink supply roll.
The ink has a viscosity of 1000 cPs and has thixotropy.
The CTP plates were produced according to the intended plate shape in the manufacturing steps shown in FIGS. 3 (a) to 3 (e).
As a result, h1 / h2 in FIG. 1 was 2.1.
Further, for the area S of the rectangular portion 19 in FIG. 1, S / (L × L) was 7.1.
[0020]
【The invention's effect】
As described above, the present invention is produced by a flexographic printing method capable of responding quantitatively and costly in terms of productivity and quality, and has an electromagnetic wave shielding effect on one surface of a film substrate. Providing a member for an electromagnetic wave shield provided with a mesh can also be handled in terms of quality.
[Brief description of the drawings]
FIG. 1 (a) is a plan view showing an example of an embodiment of an electromagnetic wave shielding member of the present invention, and FIG. 1 (a1) is an enlarged view of a portion A1 in FIG. 1 (a). 1 (b) is a cross-sectional view taken along line A2-A3 in FIG. 1 (a), FIG. 1 (c) is a diagram showing an intersection of mesh portions, and FIG. 1 (d) is a diagram of FIG. 1 (c). It is sectional drawing in A4-A5.
FIG. 2 is a diagram illustrating an example of an apparatus for performing a flexographic printing method.
3 (a) to 3 (e) are cross-sectional views of a CTP plate manufacturing process, and FIGS. 3 (a1) and 3 (c1) to 3 (e1) are processes for a conventional flexographic printing plate. It is sectional drawing.
FIG. 4 is a diagram for explaining an electromagnetic shielding plate using a mesh made of a metal thin film or the like.
DESCRIPTION OF SYMBOLS 10 Electromagnetic shielding member 11 Mesh part 12 Grounding frame part 13 Film base material 14 Electromagnetic wave shielding ink 15 (X direction) Line 16 (Y direction) Line 17 Intersection part Px, Line x direction pitch Py Line y direction Pitch 21 Ink supply roll 22 Plate cylinder 23 Impression cylinder 24 Ink reservoir 25 Squeegee 26 Plate (also called flexographic resin plate)
27 Film substrate 28 (Electromagnetic wave shielding) ink 29 Guide roll 31 Base substrate 32 UV curable resin 32a Cured portion 32b UV curable resin remaining after development (also referred to as insolubilized portion)
32c UV curable resin after post exposure 33 Mask layer 34 UV light 36 Masking film (also called film pattern)
37 Vacuum sheet 38 Convex part 40 Electromagnetic wave shielding plate 41 for electromagnetic wave shielding Mesh part 42 Grounding frame part 43 Transparent substrate 44 Metal thin films 45 and 46 lines

Claims (2)

The electromagnetic wave shielding ink transferred from the ink supply roll of the anilox roll to the plate cylinder is transferred from the plate cylinder to one surface of the film substrate while the web-shaped film substrate is conveyed while being sandwiched between the plate cylinder and the impression cylinder. In addition, two or more lines of line width L of mesh made of electromagnetic wave shielding ink intersect by a flexographic printing method using a continuous transfer formation method and a CTP (Computer To Plate) plate for the plate cylinder. In the electromagnetic wave shielding member having an electromagnetic wave shielding property in which the pattern to be arranged is disposed on one surface of the film base, the film thickness at the line intersection where the line of the line width L intersects is 1.2 times that of the line part . The member for electromagnetic wave shielding characterized by being- 3 times . 2. The electromagnetic wave shielding member according to claim 1, wherein an area of the line intersection portion where the lines having the line width L intersect is 2 to 30 times L × L.

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