JP2002275661A - Method for manufacturing metal foil mesh - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method by which a single metal foil mesh having both of excellent light transmitting property and shielding property against electromagnetic waves can be manufactured in easy processes without contaminating the manufacture line of coater, laminator, or the like, even when the metal foil is a metal-plated foil. SOLUTION: A photoresist layers 2 is formed on both surfaces of a metal foil 1, and on photoresist layer 2 is exposed into a specified mesh patter, while the other photoresist layer 2 is wholly exposed to form a developed resist part 4. The part 5 not developed in the photoresist layer is removed, and the metal foil 1 corresponding to the removed part is etched. Then the developed resist parts 4 on both surfaces of the metal foil 1 is removed concurrently so as to produce a metal foil mesh signal body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a metal foil mesh using a photoresist method, and more particularly to a metal foil mesh applied to an electromagnetic wave shielding material and the like, particularly a metal foil mesh suitable as an electromagnetic wave shielding material for a display. And a method for producing the same.

[0002]

2. Description of the Related Art In recent years, an electromagnetic wave shielding material has attracted attention as one of means for blocking electromagnetic waves emitted from electronic equipment. As an electromagnetic wave shielding material, a material using a so-called wire mesh as a metal mesh formed by knitting a metal wire typified by a sieve for classifying fine particles in a lattice shape is known. Further, for example, there is also known an electromagnetic wave shielding material using a metal mesh in which a resin fiber such as polyester is used as a base material and a metal such as copper or nickel is coated on the base material by means such as electroless plating.

[0003] Some of these electromagnetic wave shielding materials are applied to displays such as plasma displays. In that case, it is necessary to be as thin as possible, and it is necessary to balance the light transmittance and the electromagnetic wave shielding property contradictory thereto, in a well-balanced manner. −35
No. 0168 discloses a metal foil mesh.

[0004]

However, the above-mentioned conventional method for producing a metal foil mesh is a method for producing a metal foil mesh having a structure laminated on a base material with an adhesive or the like.
It was difficult to obtain a metal foil mesh as a single body.
In addition, when the metal foil to be used is metal-plated, there is a problem that particles of the plated metal fall off from the metal foil during the production of the metal foil mesh and stain the coater or the laminator.

Accordingly, the present invention provides excellent light transmittance and electromagnetic wave shielding properties in a simple process without contaminating a production line such as a coater or a laminator even if a metal foil is plated with metal. It is an object of the present invention to provide a method capable of manufacturing a single metal foil mesh having the same.

[0006]

According to the present invention, there is provided a method of manufacturing a metal mesh, comprising the steps of forming a photoresist layer on both sides of a metal foil; Exposing the resist layer to the entire surface to form a developed resist portion, removing the undeveloped portion of the photoresist layer, etching the metal foil corresponding to the removed portion, and removing the developed resist portion. It is characterized by having.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. In the method for manufacturing a metal foil mesh of the present invention, first, a photoresist layer is formed on both surfaces of a metal foil. As a method for forming a photoresist layer on both surfaces of the metal foil, a liquid photoresist may be applied on the metal foil by a roll coater method, a dipping method, a spray method, a spinner method, or the like. It is preferable to form a photoresist layer 2 on both sides of the metal foil 1 by applying a dry film resist while applying pressure to both sides of the metal foil 1 as shown in FIG.

Next, as shown in FIG. 1B, a mask 3 on which a predetermined mesh pattern is printed as a light transmitting portion is laminated on one surface of the photoresist layer 2.
The mask 3 is irradiated with ultraviolet light or the like. The photoresist layer 2 may be a negative type that is cured by ultraviolet rays or the like.
A positive type that can be decomposed by ultraviolet rays or the like can also be used. In this case, a light-transmitting or non-transmitting mesh pattern of the mask 3 is used as appropriate. Although the photoresist layer 2 formed on both surfaces of the metal foil 1 may be a different type of photoresist, it is possible to simultaneously remove development resist portions 4 formed on both surfaces of the metal foil 1 described later. Therefore, the same type of photoresist is preferable.

As a result, as shown in FIG. 1C, a portion of the photoresist layer corresponding to the light transmitting portion of the mask 3 is exposed, and the exposed portion becomes a developing resist portion 4 on the metal foil 1. The formed and unexposed portions remain as undeveloped portions 5. On the other hand, in the other photoresist layer 2, as shown in FIG. 1B, by performing exposure on the entire surface of the photoresist layer 2, a development resist portion 4 having the entire surface cured is formed. The exposure of the photoresist layer 2 may be performed on one side or on both sides at a time. As the above-described exposure, a means for directly irradiating the photoresist layer 2 with laser light may be used instead of laminating the mask 3 and irradiating with ultraviolet rays or the like.

Next, the mask 3 is removed, and the mask 3 is immersed in a processing solution for removing the resist to remove the undeveloped portions 5 of the photoresist layer. As a result, as shown in FIG. 1D, only the developing resist portion 4 formed in a mesh pattern is formed on the surface of the metal foil 1 on one surface, and the developing resist portion 4 is formed on the other surface from an etching solution or the like in an etching process. A development resist portion 4 serving as a protective film for protecting the metal foil 1 is formed. Next, as shown in FIG. 1 (e), the metal foil 1 in the portion corresponding to the undeveloped portion 5 is etched by etching means such as chemical etching, and then the remaining development resist portions 4 on both surfaces of the metal foil 1 are removed. By removing them all at once or separately, a single metal foil mesh 10 as shown in FIG. 1 (f) can be obtained.

When the metal foil mesh obtained by the present invention is used as an electromagnetic wave shielding material for a display,
In order to improve the visibility, it is preferable that the front surface side (the viewing surface side of the display) of the shield material is black. In this case, it is generally known that the metal foil is subjected to black oxidation treatment before or after the step of removing the developed resist portion. Is performed in advance to blacken the metal foil surface, and further, after the step of removing the development resist portion, the etched metal foil mesh is heated and oxidized to blacken the non-metal plated portion. Is preferred. The metal foil may be plated on one side or both sides.

In the present invention, even when a metal foil plated with the above-described metal particles is used, a photoresist layer is formed on both surfaces of the metal foil, so that a The metal plating portion on the metal foil surface does not contact the used coater or laminator, and there is no contamination of the coater or laminator.

Further, the mesh pattern of the metal foil mesh obtained by the present invention can be freely controlled in a developing step by a photoresist method. When the mesh pattern is used as an electromagnetic wave shielding material for a display, light transmission and electromagnetic wave shielding are required. In order to achieve both compatibility with the characteristics, it is preferable that the width of the line portion of the mesh pattern is 10 to 50 μm, preferably 15 to 30 μm, and the aperture ratio is 80% or more, preferably 85% or more. Here, the aperture ratio refers to the total area of the holes with respect to the effective use area of the metal foil. Also, the width of the holes (the pitch of the line portions) of the mesh pattern is 100 to
500 μm is suitable, preferably 150 to 300 μm
m.

Further, the mesh pattern is preferably a geometric pattern, and the shape of the holes is appropriately selected from a parallelogram such as a square or a rectangle, a circle or a regular hexagon (a honeycomb shape). In addition, since it is important that each part has a certain characteristic (mainly light transmittance and electromagnetic wave shielding properties, etc.), it is preferable that the parts are arranged regularly.

The material of the metal foil used in the present invention includes:
Metals such as copper, iron, nickel, aluminum, gold, silver, platinum, and the like, and two or more alloys of these metals (eg, a copper-nickel alloy, stainless steel, etc.), and metal compounds that can be made into a foil. A system material is used. Among these metals, an alloy or a metal compound of copper, aluminum, iron, and nickel, which is easily formed into a foil by rolling or the like, is particularly preferable because it can be manufactured at low cost. Also, the thickness is preferably as thin as possible,
It is 5 to 50 m, preferably 8 to 40 m, more preferably 10 to 25 m.

As the photoresist layer used in the present invention, various conventionally known photoresists can be used, but a photopolymerization type photosensitive resin is preferable. Specifically, a photopolymerization monomer, a binder resin A commonly used photocurable composition comprising a photopolymerization initiator and other auxiliaries is preferably used. In the method for producing a metal foil mesh of the present invention, a dry film resist of the alkaline water phenomenon type is particularly suitable.

Examples of the photopolymerizable monomer include ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and neopentyl glycol di (meth) acrylate. ) Acrylate, 1,6-hexanediol di (meth) acrylate, 2,2-bis [4- (meth) acryloxypropoxy phenyl] propane, trimethylolpropane tri (meth) acrylate, pentaerythritol penta (meth) Acrylate, tri (meth)
Acryloxyethyl phosphate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, pentaerythritol penta (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate, glycerin triglycidyl ether tri (meth) acrylate, etc. These may be used alone or as a mixture of two or more.

Examples of the binder resin include vinyl copolymers, polyesters, epoxy resins and the like, and these are usually used alone or as a mixture of two or more. Examples of the monomer component used in the vinyl copolymer include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, and (meth) acrylate.
Propyl acrylate, butyl (meth) acrylate, 2-
Examples include hydroxyethyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, methoxyethyl (meth) acrylate, styrene, (meth) acrylamide, (meth) acrylonitrile, and vinyl acetate. These monomers are usually used alone. Or a mixture of two or more.

The polyester may be (phthalic anhydride),
Di- or higher-valent carboxylic acids such as isophthalic acid, terephthalic acid, tetrahydrophthalic anhydride, (anhydride) maleic acid, fumaric acid, adipic acid, trimellitic anhydride, pyromellitic anhydride, and ethylene glycol, propylene glycol, 1,3- Butanediol, diethylene glycol,
It is obtained by an esterification reaction with a dihydric or higher alcohol such as dipropylene glycol, triethylene glycol, neopentyl glycol, hydrogenated bisphenol A, glycerin, and trimethylolpropane.

The epoxy resin includes, for example, bisphenol epoxy resin and novolak epoxy resin, and is obtained by adding a monovalent carboxylic acid such as acetic acid, oxalic acid, (meth) acrylic acid and the like. You may.

In the present invention, a photopolymerizable monomer,
The mixing ratio (weight ratio) with the binder resin is 10 / 90-
It is preferably adjusted to be 70/30, particularly 30/70 to 50/50.

Examples of the photopolymerization initiator include benzophenone, Michler's ketone, 4,4'-bis (diethylamino) benzophenone, t-butylanthraquinone,
Examples thereof include 2-ethylanthraquinone, thioxatones, benzoin alkyl ethers, and benzyl ketals, which are used alone or in combination. The photopolymerization initiator is usually contained in the total solids of the photoresist in an amount of about 0.1%.
It is preferable to contain it in an amount of from 01 to 30% by weight.

The photoresist may contain a sensitizer, a dye, a color pigment, an adhesion improver, a polymerization inhibitor, a coating surface improver, a plasticizer, and the like, if necessary.
Commercially available photoresists include Alpho NIT series manufactured by Nippon Synthetic Chemical Industry Co., Ltd., PMER series manufactured by Sankyo Chemical Co., Ltd., and Liston series manufactured by DuPont Japan.

[0024]

As described above, according to the method for manufacturing a metal foil mesh of the present invention, the development of the mesh pattern and the formation of the protective film are simultaneously performed by forming a photoresist layer on both surfaces of the metal foil. Further, after the etching of the metal foil, the development resist portions on both surfaces of the metal foil can be removed at a time. Further, even if the metal foil is metal-plated, it does not contaminate a production line such as a coater or a laminator. Therefore, a simple metal foil mesh having both excellent light transmittance and electromagnetic wave shielding properties can be manufactured by a simple process.

[Brief description of the drawings]

FIG. 1 is a sectional view conceptually showing a method for producing a metal foil mesh of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Metal foil, 2 ... Photoresist layer, 3 ... Mask, 4 ...
Developed resist part, 5: undeveloped part, 10: metal foil mesh.

Claims (4)

[Claims] A step of forming a photoresist layer on both surfaces of a metal foil; exposing a predetermined mesh pattern to one of the photoresist layers and exposing the other photoresist layer to form a developed resist portion; Removing the undeveloped portion of the photoresist layer, etching the metal foil corresponding to the removed portion, and removing the developed resist portion. Production method. 2. The method according to claim 1, further comprising a step of oxidizing the metal foil after the step of removing the developing resist portion. 3. The method according to claim 1, wherein the metal foil is plated with a metal. 4. The metal foil is made of any one of copper, iron, nickel, aluminum, gold, silver, and platinum, or an alloy or a metal compound of two or more thereof, and has a thickness of 5 to 50 μm. The method for producing a metal foil mesh according to claim 1, wherein: