KR102349047B1 - Manufacturing method for oxide film - Google Patents

Abstract

Disclosed is a method for forming an oxide film, which can form an oxide film on the surface of various materials, unlike a copper material needs to be used when forming an existing oxide film by attaching copper foil to the surface of a case to form the oxide film. The present invention provides the method for forming an oxide film, including the steps of: forming a body case in which a lens window is formed on one side; attaching the copper foil to the periphery of the inner and outer surfaces of the lens window; forming irregularities by laser processing or sanding the surface of the attached copper foil; and forming a low-reflection coating layer by coating a black oxide on the surface of the irregularities.

Description

Oxide film formation method {Manufacturing method for oxide film}

The present invention relates to a method for forming an oxide film, and more particularly, by attaching a copper foil to the surface of a case to form an oxide film. It relates to a method for forming an oxide film that can be formed.

In general, when various electronic devices or communication devices such as portable wireless terminals and digital cameras are used, electronic components provided in the various electronic devices or communication devices generate electromagnetic waves, where the electromagnetic waves generated by the electronic components are Strictly regulated

While such electromagnetic waves are usefully used such as wireless communication or radar, they adversely affect the operation of electronic devices and act as a harmful element to the human body. Therefore, various electronic devices or communication devices must perform an environmental compatibility test (EMC: ElectroMagnetic Compatibility) to check whether electromagnetic waves are suitable for the user's environment.

The electromagnetic environment compatibility test (EMC) conducted here is divided into EMI (ElectroMagnetic Interfernece) and EMS (ElectroMagnetic Susceptibility) tests to block electromagnetic waves harmful to the human body due to radiated noise, and are conducted and strictly regulated.

Therefore, electronic components mounted on the printed circuit board inside the electronic device are covered with a predetermined shield can to block harmful or disturbing electromagnetic waves generated from the electronic components, thereby allowing the operation of other electronic devices as well as their own electronic devices. in order not to affect it.

The shield can usually takes the shape of a box with an open bottom so as to cover electronic components. The shield can is installed on the printed circuit board through a shield can fixing clip coupled to the printed circuit board to clamp the sidewall of the shield can. In general, a plurality of coupling holes are formed on a printed circuit board, and a box-shaped shield can with an open side is inserted into the clamping part of the clip in a state in which a clip having a clamping part is inserted into the clamping hole to be engaged. It is designed to shield the electronic component located inside the shield can.

In addition, in the case of the shield can, in addition to the electromagnetic wave blocking effect, it is used to secure additional rigidity to the parts. In particular, recently, in mobile terminals such as cell phones and PDA's, the function of taking and storing pictures or videos has been emphasized, and camera modules are generally installed. A shield can for the camera module is installed to protect it from

In the shield can for the camera module, a lens window opening for a camera lens is perforated in the camera body housing, and a black painting layer or a black printing layer for reducing reflectance is formed around the lens window opening.

However, in the prior art, there is a problem in that the AR (anti-reflective coating) operation is performed a number of times to protect the coating layer, thereby increasing the working time and increasing the production cost of the product.

In order to improve this, a technology for performing anti-reflective coating operation using a black oxide film is used. However, the black oxide film has a disadvantage that it can be performed only on the surface of copper, so that the shield can must be made of expensive copper, and at the same time, it is difficult to process and has the disadvantage of being vulnerable to corrosion.

Therefore, there is a need for a new shield can and a method for forming an oxide film to solve these problems.

(0001) Republic of Korea Patent No. 10-1658821 (0002) Republic of Korea Patent No. 10-1941024

The present invention has been devised to solve the above problems, and an object of the present invention is to provide a method for forming an oxide film capable of forming a black oxide film on the surface of various materials.

Another object of the present invention is to provide a shield-can module for a portable device camera having a black oxide film layer formed thereon.

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above problems, the present invention comprises the steps of: forming a body case in which a lens window is formed on one side; attaching a copper foil to the periphery of the inner and outer surfaces of the lens window; forming irregularities by laser processing or sending the surface of the attached copper foil; and coating a black oxide on the concave-convex surface to form a low-reflection coating layer.

In one embodiment, the step of attaching the copper foil, processing the surface of the portion to which the copper foil is to be attached to form a depression; applying an adhesive to the surface of the depression; inserting the copper foil into the depression to which the adhesive is applied; and curing the adhesive by heating the copper foil, wherein the adhesive includes a microcapsule containing a polymer monomer, a solvent, and a polymerization catalyst therein, wherein the microcapsule contains a polymerization catalyst in temperature-dependent oil. emulsifying by mixing an aqueous solution containing; and adding the emulsified solution to the coating solvent in which the coating material is dissolved, and treating the aqueous solution containing the polymerization catalyst and the temperature-dependent oil to be coated on the coating material and encapsulated into fine particles. manufactured, wherein the temperature-dependent oil includes any one of coconut oil, triglycerides, fatty acids, or a mixture thereof, and the coating material is a methacrylic acid-based material, shellac, CAP (Cellulose acetate phthalate), PVAP (Polyvinyl acetate phtahalate), containing at least one of HPMCAS (Hydroxypropyl methylcellulose acetate succinate), the polymer monomer is a polymer monomer comprising a polyol and an isocyanate, The polymerization catalyst may be an amine-based catalyst or a trimerization catalyst have.

In an embodiment, the copper foil has a microstructure layer formed on one surface in contact with the adhesive to enhance adhesion, and the forming of the microstructure layer comprises: (a) a macro pattern on the surface of the copper foil applying a material; (b) etching the macro pattern material at regular intervals to form a macro pre-pattern, exposing a lower copper foil; (c) attaching the copper foil exposed through etching to the side surface of the macro pre-pattern after the etching is completed; and (d) removing the macro prepattern to form a microstructure pattern, wherein step (b) is to apply a macro pattern material on a film and then perform a lithography or imprinting process to perform a macro prepattern The etching is a milling process performed by forming plasma using a gas under a pressure of 0.1 mTorr to 10 mTorr and then accelerating the plasma to 100 eV to 5,000 eV, and the microstructure pattern has a height of 10 nm to 10 μm, The thickness may be 1 to 10 nm, and the spacing between the patterns may be 10 nm to 10 μm.

In one embodiment, after the step of forming the concave-convex surface through laser processing or sanding, a pretreatment step of immersing in a pretreatment solution may be included.

In one embodiment, the low-reflection coating layer includes black oxide, carbon nanotubes, acrylic resin, unsaturated polyester resin, zirconium oxide, potassium cocoyl hydrolyzed collagen and soda feldspar, the composition ratio of the low-reflection coating layer Silver, 45 to 60% by weight of black oxide, 20 to 30% by weight of carbon nanotubes, 1 to 10% by weight of acrylic resin to improve adhesion of the coating layer, 1 to 5% by weight of thermosetting unsaturated polyester resin, 1 to 5% by weight of zirconium oxide, 1 to 5% by weight of potassium cocoyl hydrolyzed collagen, and 1 to 3% by weight of soda feldspar may be one.

In one embodiment, the oxide film may be formed on a camera shield can for a portable device.

According to an embodiment of the present invention, a black oxide film can be formed on the surface of a shield can that is not made of copper, so it is possible to manufacture a shield can that is superior in durability and has various functions compared to a conventional copper can.

In addition, in the present invention, since the oxide film is formed using a copper thin film, it is possible to form the oxide film through a simple process compared to the conventional method for producing an oxide film using etching.

In addition, in the case of the present invention, it is possible to provide a method for producing an oxide film having superior visible light absorption compared to the conventional oxide film by using carbon nanotubes to form the oxide film.

The effect according to the present invention is not limited by the contents exemplified above, and more various effects are included in the present invention.

1 is a perspective view of a shield can according to an embodiment of the present invention.
2 is a view showing a bottom portion of a shield can according to an embodiment of the present invention.
3 is a cross-sectional view taken along AA according to an embodiment of the present invention.
4 is an enlarged view of part B according to an embodiment of the present invention.

Hereinafter, various embodiments will be described in more detail with reference to the accompanying drawings. The embodiments described herein may be variously modified. Certain embodiments may be depicted in the drawings and described in detail in the detailed description. However, the specific embodiments disclosed in the accompanying drawings are only provided to facilitate understanding of the various embodiments. Therefore, the technical idea is not limited by the specific embodiments disclosed in the accompanying drawings, and it should be understood to include all equivalents or substitutes included in the spirit and scope of the invention.

Terms including an ordinal number such as 1st, 2nd, etc. may be used to describe various components, but these components are not limited by the above-mentioned terms. The above terminology is used only for the purpose of distinguishing one component from another component.

In this specification, terms such as "comprises" or "have" are intended to designate that the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof. When an element is referred to as being “connected” or “connected” to another element, it is understood that it may be directly connected or connected to the other element, but other elements may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

Meanwhile, as used herein, a “module” or “unit” for a component performs at least one function or operation. And “module” or “unit” may perform a function or operation by hardware, software, or a combination of hardware and software. In addition, a plurality of “modules” or a plurality of “units” other than a “module” or “unit” to be performed in specific hardware or to be executed in at least one processor may be integrated into at least one module. The singular expression includes the plural expression unless the context clearly dictates otherwise.

In addition, in describing the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be abbreviated or omitted.

1 is a perspective view of a shield can according to the present invention, and FIG. 2 shows a bottom part thereof.

The present invention comprises the steps of forming a body case in which a lens window is formed on one side; attaching a copper foil to the periphery of the inner and outer surfaces of the lens window; forming irregularities by laser processing or sending the surface of the attached copper foil; and coating a black oxide on the concave-convex surface to form a low-reflection coating layer.

The body case 10 is a portion that becomes the body of the shield can of the present invention, and may have a size and shape in which a camera for a portable device can be installed therein. The body case is preferably manufactured by bending a metal plate, and in addition, the metal plate may be press-molded using a press machine, or manufactured by methods such as casting, forging, or extrusion (see FIG. 1).

In addition, the body case 10 is formed in the shape of a “c” in cross section, so that both leg portions can be fixed to a board on which a camera for a portable device is mounted, in this case, the center of the camera lens and the lens window 11 . can be fixed to match. In addition, although only one lens window 11 may be formed in the case, it is also possible to form 2 to 10 lenses to cover all the mounted cameras with one shield can.

The body case 10 may be made of various materials. In the case of an existing body case, it is generally made of copper for a black oxide coating, which will be described later, but in this case, when used for a long time, copper may corrode and damage may occur. In order to improve this, a surface treatment was additionally performed on the surface of the copper or the shield can was mounted and then sealed. However, in this case, additional cost is required. In the case of the present invention, since black oxide coating is performed by attaching a copper foil to be described later to the body case, the body case can be made of various materials depending on the required purpose. For example, if corrosion resistance is required, it may be made of stainless steel, aluminum, or titanium, and if insulation is required, it may be manufactured and used with a polymer resin. In addition, in order to increase the shielding performance of the electronic vehicle, it is possible to form a microstructure made of metal on the surface of the body case or to apply a carbon-based component such as carbon nanotubes.

After the body case 10 is manufactured as described above, a copper foil may be attached to the periphery of the inner and outer surfaces of the lens window 11 of the body case. In the case of the existing shield case, the low-reflection coating layer 20 was formed by coating a portion except for the periphery of the inner and outer surfaces of the lens window with metal and coating the peripheral portions of the inner and outer surfaces of the lens window with black oxide. In the case of , it has a disadvantage that the manufacturing cost is high as it goes through a number of printing and etching steps. In addition, since the shield can is manufactured by being bent into various shapes, the difficulty of printing and etching may increase, thereby increasing the manufacturing cost.

Therefore, in the present invention, since the step of exposing copper around the inner and outer surfaces of the lens window 11 can be changed to simply attaching a copper foil, the shield can can be manufactured with a simple manufacturing method compared to the existing shield can manufacturing method. It is possible.

To this end, the step of attaching the copper foil may include processing the surface of the portion to which the copper foil is to be attached to form a depression; applying an adhesive to the surface of the depression; inserting the copper foil into the depression to which the adhesive is applied; and curing the adhesive by heating the copper foil.

The periphery of the inner and outer surfaces of the lens window to which the copper foil is attached may be surface-processed to form a depression. In the case of the copper foil, since the oxide is formed on the portion, if the copper foil is not attached to the correct position, an afterimage may occur due to reflected light or a defect in color spreading may occur. Therefore, in the case of the copper foil, it must be attached at an accurate position, and for this purpose, it is possible to attach the copper foil to an accurate position by processing the periphery of the inner and outer surfaces of the lens window to form a depression.

At this time, the recessed portion may serve as a guide so that the copper foil is attached to the correct position, and is manufactured to have the same size as the copper foil or to be 1 to 5% larger than the size of the copper foil to facilitate insertion of the copper foil. can At this time, when the size of the recessed portion is manufactured to be larger than the size of the copper foil by 5%, it may be difficult to fix the copper foil in an accurate position (see FIGS. 3 and 4 ).

In addition, the depth of the depression may be manufactured to a depth of 30 to 100% of the thickness of the copper foil. If the depth of the depression is less than 30% of the thickness of the copper foil, it may be difficult to fix the copper foil, and if it exceeds 100%, diffuse reflection occurs in the height portion that exceeds 100%, so that the image quality of the camera may be deteriorated.

After the depression is formed, an adhesive may be applied to the inside of the depression. In particular, in the case of the present invention, since the copper foil must be fixed at an accurate position, it is preferable that the position of the copper foil can be accurately corrected even after the adhesive is applied. Therefore, in the case of the adhesive, an adhesive adjusted to cure only at a temperature exceeding a certain temperature may be used.

To this end, the adhesive may include a microcapsule containing a polymer monomer, a solvent, and a polymerization catalyst therein.

The polymer monomer refers to a monomer that forms a polymer and is cured when polymerized. More preferably, the polymer monomer may be a polymer monomer including a polyol and an isocyanate. Therefore, the polymer monomer can form urethane after polymerization, and this urethane not only has a high adhesion effect to the copper foil and the body case, but also has appropriate elasticity, so that even if the copper foil is subjected to an impact while using the mobile device, the copper foil is separated can make it not happen.

In this case, the polyol may be a polyether-based or polyester-based polyol, and the isocyanate may be an aromatic isocyanate, an aliphatic isocyanate, or a combination thereof.

In this case, the polyol used may be a polyether-based polyol, a polyester-based polyol, or a mixture thereof, and the polyether-based polyol has a polyhydric alcohol such as sucrose, sorbitol, glycol, glycerol, etc. It can be selected from copolymer polyols such as ethylene oxide and propylene oxide in the starting material, which is a compound in the present invention.

In addition, the polyester-based polyol is synthesized by using a polybasic acid and a polyalcohol having a hydroxyl group such as glycol and glycerol as a solvent, and the polyhydric alcohol is ethylene glycol, 1-4 butanediol, and 1,6-hexanediol. , polyethylene glycol, diethylene glycol, and the like, and the polybasic acid may be selected from aromatic base acids such as terephthalic acid, adipic acid, maleic acid, and succinic acid, aliphatic dibasic acids, and the like.

The aromatic isocyanate is diphenylmethane diisocyanate (4,4'-Diphenylmethnae diisocyanate, MDI), polymeric diphenylmethane diisocyanate (polymeric 4,4'-Diphenylmethnae diisocyanate, PMDI), toluene diisocyanate (toluene diisocyanate, TDI), A compound containing 1-4 phenylene diisocyanate (1,4-phenylene diisocyanate, PPDI) and 1,5-naphthalene diisocyanate (1,5-Naphthalene diisocyanate, NDI) is an isocyanate having an aromatic ring.

The aliphatic isocyanate is 1,6-hexamethylene diisocyanate (1,6-Hexamethylene diisocyanate, HDI), isophorone diisocyanate (Isoporon diisocyanate, IPDI), dicyclohexylmethane-4,4'-diisocyanate (Dicyclohexylmethane-4) ,4'-diisocyanate, H12MDI) may be used.

A catalyst is required to synthesize the polyol and the isocyanate. However, in the case of the urethane resin used in the present invention, it is preferable that the copper foil be cured after being seated in the correct position as described above. Therefore, in the present invention, it is possible to delay curing until a desired point by preventing contact with the polymer monomer by microencapsulating the catalyst. In addition, since the microcapsule has thermal sensitivity, it can be cured by simply heating after the copper foil is seated, and the copper foil can be fixed at a desired position without additional processing.

The catalyst is included in order to promote the crosslinking reaction between the polyol and the isocyanate, and may be used without limitation as long as it is a catalyst generally used in the manufacture of polyurethane. However, in order to increase the reactivity and improve physical properties, preferably, an amine-based catalyst and a trimerization catalyst may be mixed and used, and more preferably N,N-dimethylcyclohexylamine (N,N-dimethylcyclohexylamine), N,N, N',N'-pentamethyldiethylenetriamine (N,N,N',N'-pentamethyldiethylenetriamine), triethylenediamine, di-N-butyltindilaurylate, potassium acetate, lithium acetate, acetic acid Magnesium, an organotin compound, an organotitanium compound, or a combination thereof may be used.

The microcapsules are emulsified by mixing an aqueous solution containing a polymerization catalyst with temperature-dependent oil; and adding the emulsified solution to the coating solvent in which the coating material is dissolved, and treating the aqueous solution containing the polymerization catalyst and the temperature-dependent oil to be coated on the coating material and encapsulated into fine particles. can be manufactured.

The temperature-dependent oil is applied as an emulsifier, and is preferably a temperature-sensitive oil capable of dissolving in a liquid phase around 45° C., which is a temperature that can promote the polymerization of the urethane resin, and releasing the catalyst for polymerization of the urethane resin.

As the temperature-dependent oil, it is preferable to use coconut oil, triglycerides, fatty acids, or a mixture thereof, and it is preferable to use a combination of these oils so that they can be melted at a temperature of 40 to 50 ° C.

The coconut oil is a fat that is extracted from the core of a palm tree that grows wild on the coast of tropical regions such as the Philippines, Indonesia, and Malaysia, also called copra oil, and has a melting point of 23 to 28 ℃, C10, C12 , is composed of saturated fatty acids of C14. In addition, the coconut oil has higher biodegradability and lower soil toxicity compared to semisynthetic lipids such as dynasan, witepsol or compritol.

Alternatively, the temperature-dependent oil may be solid at room temperature but melted at high temperature to become liquid triglycerides, fatty acids, or mixtures thereof. Here, as triglycerides, tricaprine, trilaurin, trimyristine alone or a mixture may be applied. In addition, as the fatty acids, capric acid, lauric acid, myristic acid alone or a mixture thereof may be applied. In addition, since the melting temperature of the oils may be less than 40° C., it is preferable to adjust the melting point by mixing with other types of oils. In particular, mink oil has a melting point of 80 to 95°C, and wax may reach 100°C.

Next, an emulsification treatment for emulsifying a solution in which an aqueous solution containing a polymerization catalyst and a temperature-dependent oil are mixed may be performed. The emulsification treatment may be performed by vibration, stirring, ultrasonic treatment, or the like.

After the emulsification treatment is completed, the emulsified solution is added to the coating solvent in which the coating material is dissolved, and the aqueous solution containing the polymerization catalyst and the temperature-dependent oil are coated on the coating material and encapsulated into fine particles. Microcapsules can be prepared. The coating material is preferably present in a solid state under storage conditions to increase the physical stability of the particles during storage, increase the chemical stability of the basic aqueous solution contained in the particles, and dissolve or Substances that can be destroyed to effectively release the polymerization catalyst can be applied.

The coating material preferably contains at least one of a methacrylic acid-based material, shellac, cellulose acetate phthalate (CAP), polyvinyl acetate phtahalate (PVAP), and hydroxypropyl methylcellulose acetate succinate (HPMCAS).

Thereafter, dispersion treatment may be performed so that the coating material can be uniformly dispersed in the emulsion solution. The dispersion treatment is a process in which the coating material captures the emulsion solution and uniformly encapsulates it in microparticle size, and it can be treated by methods such as sonication, stirring, vibration, and the like. Through this, the coating material forms a microcapsule, and an aqueous solution containing a polymerization catalyst may be included in the microcapsule.

The weight ratio of the temperature-dependent oil: the aqueous solution containing the polymerization catalyst: the coating material is preferably 9:1:4. In the above ratio, it is possible to produce an appropriate microcapsule, but if it is out of the above ratio, it may not be easy to generate the microcapsule.

In addition, the copper foil may have a microstructure formed on one surface in contact with the adhesive. In the case of the copper foil, as described above, black oxide may be coated to be linearized. Therefore, in order to prevent the copper foil from falling off, one surface of the copper foil, that is, the surface in contact with the adhesive, is preferably surface-treated to enhance adhesion by the adhesive.

Forming the microstructure layer, (a) applying a macro pattern material on the surface of the copper foil; (b) etching the macro pattern material at regular intervals to form a macro pre-pattern, exposing a lower copper foil; (c) attaching the copper foil exposed through etching to the side surface of the macro pre-pattern after the etching is completed; and (d) removing the macro pre-pattern to form a microstructure pattern.

Step (a) is a step of applying a macro pattern material to the copper foil, and is a step of preparing a layer in which the macro pattern is to be formed by applying the macro pattern material to the surface of the copper foil. At this time, the macro pattern material may be applied to the surface of the copper foil through a method such as spraying, roller coating, deposition, etc., and since the height of the microstructure is determined in proportion to the thickness of the macro pattern layer, the thickness of 100 μm It is more preferable to apply using vapor deposition which can apply uniformly.

The macro pattern material may be made of polystyrene, chitosan, polyvinylalcohol, polymethyl methacrylate (PMMA), a photoresist compound, or a conductive polymer. The macro pattern material is formed in a predetermined shape by a lithography or imprinting process, and a copper foil is deposited on the side surface by etching. In this case, by adjusting the height and spacing of the macro pre-pattern, the height and spacing of the deposited microstructure pattern may be adjusted.

After applying the macro pattern material, the macro pattern material may be etched at regular intervals to form a macro pre-pattern. In this case, the etching may be performed using a lithography or imprinting process as described above, and the lithography or imprinting process may be performed using the same process as previously known. In addition, at this time, the copper foil of the bottom surface may be exposed, and the exposed copper foil may be used to form a microstructure in a step to be described later.

After the macro pre-pattern is formed as described above. The exposed copper foil may be attached to the wall surface of the macro pre-pattern by etching the surface. Looking at this in detail, the copper foil exposed between the macro pre-patterns by the etching scatters in all directions. In this case, the exposed copper foil cannot flow out of the macro pre-pattern and may be attached to the wall surface of the macro pre-pattern. That is, after the etching is completed as described above, a portion of the copper foil may be attached to the wall surface of the macro pre-pattern. To this end, the etching may be performed as a milling process, particularly an ion milling process, in which a plasma is formed using a gas under a pressure of 0.1 mTorr to 10 mTorr and then the plasma is accelerated to 100 eV to 5,000 eV. In addition, the gas used for the ion milling is preferably selected from the group consisting of argon, helium, nitrogen, oxygen, and a mixture thereof.

When the copper foil is attached to the side surface of the macro pre-pattern as described above and then the macro pre-pattern is removed, only the micro-structure pattern of the copper component remains, and a micro-structure pattern can be formed on the surface of the copper foil using this. have.

As described above, the microstructure pattern may be formed of the same copper as that of the copper foil, and the surface area of one surface of the copper foil may be increased to increase bonding properties with the adhesive. At this time, in the case of the microstructure pattern, its size and shape may be determined according to the shape of the macro pre-pattern, but it may be manufactured in a linear arrangement arranged in one direction for smooth processing, and has a height of 10 nm to 10 μm and a thickness of 1 to 10 nm. , the spacing between the patterns may be 10 nm to 10 μm. When the size (height and thickness) is less than the above range, the effect of increasing the adhesiveness may be reduced. . In addition, if the gap is less than the above range, the adhesive may not penetrate between the patterns, so that the adhesive strength may be reduced.

When the copper foil is attached to the upper portion of the adhesive material as described above, the copper foil may be aligned in the correct position. This alignment is to ensure that the copper foil is accurately positioned inside the recess, and may be performed by manpower or automatically using a machine. In particular, since the copper foil has a different color from the body case, such It is possible to easily align using the color difference.

After the above alignment is completed, the adhesive may be cured by heating the copper foil. As described above, the adhesive contains a mixture of polyol and isocyanate, which are monomers of urethane, and includes microcapsules containing a catalyst therein. Accordingly, when the copper foil is heated, the microcapsules may be destroyed, and the polymerization catalyst may flow out of the microcapsules, and accordingly, the monomer may be polymerized and the adhesive may be cured. At this time, the heating may be performed at a temperature for dissolving the temperature-dependent oil and the coating material used in the microcapsule without damaging the copper foil, and may preferably be heated to 40 to 60°C. When the heating is performed at less than 40 ° C, the microcapsule does not break, so that curing of the adhesive may not occur. .

After the copper foil is attached as described above, irregularities may be formed on the surface of the copper foil through laser processing or sending. In the case of the copper foil, it is generally manufactured through electrorefining, and in the case of such regular refining, the surface flatness is manufactured to be very high. Therefore, when a low-reflection coating layer, which will be described later, is formed on the planarized surface, the adhesion between the interfaces may decrease, and thus the separation of the interfaces may occur. Therefore, in order to prevent the separation of the interface, it is preferable to form irregularities on the surface of the copper foil through laser processing or etching. In addition, when black oxide is coated on a hard surface like the copper foil, a black material in the form of a fine powder, that is, smut may be formed, and when the smut is rubbed, gloss may occur. Accordingly, when the unevenness is formed as described above, the smut state can be maintained, thereby bringing about an advantageous effect on low reflectance.

After the surface treatment of the copper foil is completed, the step of immersing in a pretreatment solution may be further included. This pretreatment liquid is used to prevent corrosion of the copper foil and shield can and to increase durability, and any pretreatment liquid used for this purpose may be used without limitation.

A black oxide may be coated on the surface of the copper foil to form a low-reflection coating layer. In this case, the low-reflection coating layer preferably includes black oxide, carbon nanotubes, acrylic resin, unsaturated polyester resin, zirconium oxide, potassium cocoyl hydrolyzed collagen and soda feldspar.

In the case of the conventional invention, a black coating layer is formed by combining black oxide and carbon black, but in the present invention, it is preferable to use carbon nanotubes instead of carbon black in order to further lower the reflectance of light.

The carbon nanotubes, especially single-walled carbon nanotubes, have very good electrical properties (very large maximum current density), and thermal properties (thermal conductivity comparable to diamond), optical properties (light emission in optical communication band wavelengths), hydrogen storage capacity , metal catalysts, etc., are attracting attention as materials for nano-electronic devices, nano-optical devices, and energy storage. In particular, the carbon nanotube is known to have high conductivity in the longitudinal direction due to its characteristics, and its strength is also known to be very high.

In addition, since the carbon tube is manufactured in the form of a tube, incident light can be diffusely reflected from the inside and at the same time converted into thermal energy and emitted, thereby minimizing the re-reflection of light incident on the carbon nanotube. Looking at this in detail, due to the structure of the carbon nanotube, the light incident to the low-reflection coating layer may be diffusely reflected inside the carbon nanotube, in which case the light loses energy and is converted into heat It can be emitted. In addition, in the case of light incident outside the carbon nanotube, since it is incident into the adjacent carbon nanotube and disappears or is absorbed by the black oxide and disappears, as a result, the reflectance of the low-reflection coating layer can be minimized. In the case of the carbon nanotubes used at this time, it is preferable to use a carbon nanotube manufactured using a vapor phase reactor, such as the device presented in Korean Patent No. 10-0732623, rather than manufactured by a commonly used chemical vapor deposition (CVD) method. . In the case of the vapor phase reactor, it is possible to absorb light of various wavelengths because the manufacturing cost is lower than that of the CVD apparatus, and the size and diameter of the carbon nanotubes to be grown are various.

In addition, in the case of the present invention, an acrylic resin may be used to improve the adhesion of the coating layer. In the case of the conventionally used melamine resin, it is possible to strengthen the adhesion due to its high compatibility with carbon black. Therefore, in the case of the present invention, it is preferable to use an acrylic resin to increase the adhesive strength in order to optimize the villli absorption rate.

In addition, due to the mixing of the unsaturated polyester resin, the thermal curing function of the coating layer is improved and the occurrence of discoloration is prevented, and the improved effect of enhancing the fire resistance function is exhibited due to the mixing of zirconium oxide. On the other hand, the additionally added potassium cocoyl hydrolyzed collagen prevents the surface gloss of the coating layer while stably maintaining the low reflectance through the activation of black oxide and carbon nanotubes, and soda feldspar improves the durability of the coating layer. Reinforced to prevent cracking.

The composition ratio of the low-reflection coating layer is 45 to 60% by weight of black oxide, 20 to 30% by weight of carbon nanotubes, 1 to 10% by weight of acrylic resin for improving adhesion of the coating layer, 1 to 5% by weight of thermosetting unsaturated polyester resin , 1 to 5% by weight of zirconium oxide, 1 to 5% by weight of potassium cocoyl hydrolyzed collagen, and 1 to 3% by weight of soda feldspar for strengthening the fire resistance function. Within the above range, the reflectance of the low-reflection coating layer may be minimized, but if it is out of the above range, the reflectance may be increased or adhesion with the copper foil may be decreased.

In the above, preferred embodiments of the present invention have been illustrated and described, but the present invention is not limited to the specific embodiments described above, and it is common in the technical field to which the present invention pertains without departing from the gist of the present invention as claimed in the claims. Various modifications are possible by those having the knowledge of, of course, and these modifications should not be individually understood from the technical spirit or prospect of the present invention.

10: body case
11: lens window
20: low reflection coating layer

Claims (6)

forming a body case having a lens window formed on one side;
attaching a copper foil to the periphery of the inner and outer surfaces of the lens window;
forming irregularities by laser processing or sending the surface of the attached copper foil; and
forming a low-reflection coating layer by coating black oxide on the surface on which the unevenness is formed;
In the oxide film forming method comprising a,
The step of attaching the copper foil,
forming a depression by processing the surface of the portion to which the copper foil is to be attached;
applying an adhesive to the surface of the depression;
inserting the copper foil into the depression to which the adhesive is applied; and
curing the adhesive by heating the copper foil;
includes,
The adhesive includes a microcapsule containing a polymerization catalyst therein, a polymer monomer, and a solvent,
The microcapsule is
emulsifying by mixing an aqueous solution containing a polymerization catalyst with temperature-dependent oil; and
A manufacturing method comprising the step of adding the emulsified solution to a coating solvent in which the coating material is dissolved, and treating the aqueous solution containing the polymerization catalyst and the temperature-dependent oil to be coated on the coating material and encapsulated into fine particles becomes,
The temperature-dependent oil includes any one of coconut oil, triglycerides, fatty acids, or a mixture thereof,
The coating material contains at least one of methacrylic acid-based materials, shellacs, CAP (Cellulose acetate phthalate), PVAP (Polyvinyl acetate phtahalate), and HPMCAS (Hydroxypropyl methylcellulose acetate succinate),
The polymer monomer is a polymer monomer comprising a polyol and an isocyanate,
The polymerization catalyst is an amine-based catalyst or a trimerization catalyst,
The copper foil is
A microstructure layer for reinforcing adhesiveness is formed on one surface in contact with the adhesive,
The step of forming the microstructure layer,
(a) applying a macro pattern material to the surface of the copper foil;
(b) etching the macro pattern material at regular intervals to form a macro pre-pattern, exposing a lower copper foil;
(c) attaching the copper foil exposed through etching to the side surface of the macro pre-pattern after the etching is completed; and
(d) forming a microstructure pattern by removing the macro pre-pattern;
includes,
In step (b), a macro pattern material is applied on the film, and then a lithography or imprinting process is performed to form a macro pre-pattern,
The etching is a milling process performed by forming plasma using a gas under a pressure of 0.1 mTorr to 10 mTorr and then accelerating the plasma to 100 eV to 5,000 eV,
The microstructure pattern has a height of 10 nm to 10 μm, a thickness of 1 to 10 nm, and an interval between the patterns is 10 nm to 10 μm.
delete delete According to claim 1,
and a pretreatment step of immersing in a pretreatment solution after the step of forming the concave-convex surface through laser processing or sanding.
According to claim 1,
The low-reflection coating layer includes black oxide, carbon nanotubes, acrylic resin, unsaturated polyester resin, zirconium oxide, potassium cocoyl hydrolyzed collagen and soda feldspar,
The composition ratio of the low-reflection coating layer is 45 to 60% by weight of black oxide, 20 to 30% by weight of carbon nanotubes, 1 to 10% by weight of an acrylic resin for improving adhesion of the coating layer, 1 to 5% by weight of a thermosetting unsaturated polyester resin , A method of forming an oxide film, characterized in that 1 to 5 wt% of zirconium oxide, 1 to 5 wt% of potassium cocoyl hydrolyzed collagen, and 1 to 3 wt% of soda feldspar for strengthening the fire resistance function.
According to claim 1,
The oxide film is an oxide film forming method, characterized in that formed on a camera shield can for a portable device.

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