KR102425833B1 - Magnetic field shielding sheet and antenna module including the same - Google Patents

Abstract

A magnetic field shielding sheet is provided. A magnetic field shielding sheet according to an embodiment of the present invention includes a plurality of magnetic particles, and an adhesive for bonding the magnetic particles to each other so that the plurality of magnetic particles have a predetermined shape, wherein the adhesive is the entire magnetic field shielding sheet It is included within 5% of the volume based on the volume. According to this, the density of magnetic particles in the sheet is high and the magnetic particles are uniformly distributed. In addition, there is an effect of improving physical properties such as magnetic permeability in the magnetic field shielding sheet, and exhibiting uniform physical properties over the entire magnetic field shielding sheet.

Description

Magnetic field shielding sheet and antenna module including the same

The present invention relates to a magnetic field shielding sheet and an antenna module including the same.

Magnetic materials are used for various electromagnetic wave shielding purposes or EMI suppression purposes of conducting wires, and their application ranges are wide because they have various types and characteristics according to the composition of the materials. Recently, magnetic materials are used in RF components such as antennas, EMC cores, power inductors, and broadband transformers, and their application areas are expanding.

In particular, when an antenna is manufactured using a magnetic material as a medium, it has a dielectric constant as well as a magnetic permeability, so that when applied to an electronic product, the product can be miniaturized. Therefore, research on a technique for applying a magnetic material to an antenna is being actively conducted.

On the other hand, the magnetic material may be manufactured in the form of a sheet and used as a magnetic field shielding sheet of the antenna. Such a magnetic field shielding sheet may be manufactured by various methods. As an example of the prior art, a mixture is prepared by mixing a magnetic material raw material through dry mixing or wet mixing, and then the mixture is mixed with a binder, a plasticizer, a dispersant, and the like to prepare a slurry. The mixed slurry is applied thinly using equipment such as Doctor Blade Casting and then dried. The sheet finished up to the drying step is generally referred to as a green sheet.

However, when the magnetic field shielding sheet is manufactured by preparing the slurry as described above, the magnetic material contained in the magnetic field shielding sheet is not uniformly distributed. In addition, when the magnetic field shielding sheet is manufactured by preparing the slurry, the magnetic material density in the manufactured magnetic field shielding sheet is not high because the amount of magnetic material that can be added to the slurry is limited. Therefore, when such a magnetic field shielding sheet is applied to an antenna, magnetic properties such as magnetic permeability are low, and it may be difficult to exhibit uniform magnetic properties over the entire magnetic field shielding sheet.

Therefore, there is an urgent need to develop a magnetic field shielding sheet for an antenna in which the density of the magnetic material contained in the magnetic field shielding sheet is high and the magnetic material contained in the magnetic sheet can be uniformly distributed.

US 10-2006-0121936 A

The present invention has been devised in view of the above points, a magnetic field shielding sheet having a high density of magnetic material contained in the magnetic field shielding sheet, and the magnetic material contained in the magnetic field shielding sheet being uniformly distributed, and an antenna module including the same Its purpose is to provide

In order to solve the above problems, in the magnetic field shielding sheet according to the present invention, a plurality of magnetic particles, and an adhesive for bonding the magnetic particles to each other so that the plurality of magnetic particles have a predetermined shape, the adhesive comprising: It is contained within 5% by volume in the magnetic field shielding sheet.

According to an embodiment of the present invention, the adhesive may include at least one of chemical bonding, heat bonding, and compression bonding.

In addition, the magnetic particles are magnetic field shielding sheet comprising at least one of an amorphous alloy and a nanocrystalline alloy.

In addition, the magnetic particles may include a soft magnetic material.

In addition, the soft magnetic material may include a metal soft magnetic material or ferrite.

In addition, the metal soft magnetic material is a Ni-Co-based alloy, Fe-Ni-based alloy, Fe-Cr-based alloy, Fe-Al-based alloy, Fe-Si-based alloy, Fe-Si-B-based alloy, Fe-Si-B -Contains at least one selected from the group consisting of -Cu-Nb-based alloys,

The ferrite is selected from the group consisting of Mn-Zn-based ferrite, Ni-Zn-based ferrite, Ni-Co-based ferrite, Mg-Zn-based ferrite, Cu-Zn-based ferrite, and cobalt-substituted Y-type or Z-type hexagonal ferrite 1 It may include more than one species.

In addition, the adhesive may include any one or more of a natural polymer compound and a synthetic polymer compound.

In addition, the polymer compound may include a rubber compound among synthetic polymer compounds.

In addition, the rubber compound may include a copolymer in which ethylene, propylene, and diene monomers are copolymerized.

The adhesive may further include a curable component for crosslinking the polymer compound.

In addition, an area ratio of the magnetic particles may be 95% or more.

In addition, the porosity may be 5% or less.

In the magnetic field shielding sheet according to the present invention to solve the above problems, a plurality of magnetic composites including an adhesive disposed to surround at least a portion of the surface of magnetic particles are adhered to each other through the adhesive, The adhesive is contained within 5% by volume in the magnetic shielding sheet.

Further, the present invention includes a magnetic field shielding unit including the magnetic field shielding sheet according to the present invention, and a radiator formed on at least one surface of the magnetic field shielding sheet.

According to an embodiment of the present invention, the radiator may be a continuous pattern.

In addition, the magnetic field shielding unit may be one in which a plurality of the magnetic shielding sheets are stacked.

According to the present invention, deterioration of physical properties such as magnetic permeability due to physical damage such as unintentional cracking of magnetic particles included in the magnetic field shielding sheet can be prevented. In particular, in the magnetic field shielding sheet according to an embodiment of the present invention, the density of magnetic particles in the sheet is high and the magnetic particles are uniformly distributed. Accordingly, there is an effect of improving physical properties such as magnetic permeability in the magnetic field shielding sheet, and exhibiting uniform physical properties over the entire magnetic field shielding sheet.

1 and 2 are cross-sectional views of a magnetic field shielding sheet according to an embodiment of the present invention, and,
3A and 3B are cross-sectional views of a magnetic field shielding unit according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and the same reference numerals are added to the same or similar components throughout the specification.

Hereinafter, a magnetic sheet for an antenna according to an embodiment of the present invention will be described in more detail with reference to the drawings.

1 and 2 , the magnetic field shielding sheet according to an embodiment of the present invention includes a plurality of magnetic particles 10 and magnetic particles 10 such that the plurality of magnetic particles 10 have a predetermined shape. and an adhesive 20 for bonding them to each other.

At this time, the magnetic field shielding sheet according to an embodiment of the present invention is not manufactured through a slurry containing magnetic particles, as will be described later, but is coated with an adhesive 20 on the magnetic particles 10 to form a magnetic composite. , by applying light, heat, and/or pressure to the adhesive 20 to bond adjacent magnetic composites to each other. Therefore, it is possible to manufacture a magnetic field shielding sheet having a higher density of magnetic particles per unit area compared to when the magnetic field shielding sheet is manufactured through a slurry containing magnetic particles. In addition, it is possible to manufacture a magnetic field shielding sheet in which magnetic particles are uniformly distributed. In detail, the adhesive 20 is included in a volume within 5% of the total volume of the magnetic field shielding sheet. That is, the volume ratio of the magnetic particles 10 to the magnetic field shielding sheet may exceed 95%.

In addition, in the case of the magnetic field shielding sheet according to an embodiment of the present invention, the adhesive 20 is formed by adhesion between the magnetic composites coated on the surface of the magnetic particles 10, and in the aggregate state before the magnetic composites are combined, the magnetic A void is formed between the composites, and the void is completely filled by the pressure applied during the bonding process of the magnetic composites, the melting or chemical bonding of adhesives, or in some cases, some voids are not filled and remain as air-containing pores. can Accordingly, in the case of the magnetic shielding sheet according to an embodiment of the present invention, the pores 30 may be included in the adhesive 20, and in this case, the porosity may be 5% or less. However, as described above, in the case of a magnetic polymer sheet formed by firing a slurry in which magnetic particles are mixed in an adhesive polymer solution, it cannot contain pores unless it is fired while containing air in the slurry, and if the magnetic polymer sheet is Even when it is fired with air and includes pores, it may be different from pores due to voids formed by adjacent magnetic particles, such as the magnetic sheet according to an embodiment of the present invention.

When the magnetic particle 10 is a magnetic material capable of expressing the magnetic permeability properties of the magnetic field shielding unit, it may include a magnetic material provided in a known magnetic field shielding unit. As a non-limiting example, the magnetic material may be a soft magnetic material. The soft magnetic material has a very small coercive force with respect to the residual magnetic flux density, and has an excellent shielding effect against an electromagnetic field because the magnetic permeability is large. The soft magnetic material may include at least one of a metal soft magnetic material and ferrite. At this time, the metal soft magnetic material is a Ni-Co-based alloy, Fe-Ni-based alloy, Fe-Cr-based alloy, Fe-Al-based alloy, Fe-Si-based alloy, Fe-Si-B-based alloy, Fe-Si-B It may include at least one selected from the group consisting of -Cu-Nb-based alloys. In addition, the ferrite is from the group consisting of Mn-Zn-based ferrite, Ni-Zn-based ferrite, Ni-Co-based ferrite, Mg-Zn-based ferrite, Cu-Zn-based ferrite, and cobalt-substituted Y-type or Z-type hexagonal ferrite. It may include at least one selected. In this case, the ferrite is, for example, an oxide of at least three metals selected from the group consisting of iron oxide and nickel, zinc, copper, magnesium and cobalt, such as Ni-Cu-Zn-based ferrite and Ni-Cu-Co-Zn-based ferrite. Ferrite containing a can also be used, but is not limited thereto. At this time, since the content of nickel, zinc, copper, magnesium and cobalt in the ferrite can be changed according to the purpose, the present invention is not particularly limited thereto.

In addition, the magnetic material included in an embodiment of the present invention may be a magnetic material of a thin plate made of an amorphous alloy or a nanocrystalline alloy.

The amorphous alloy may use an Fe-based or Co-based amorphous alloy, and it may be preferable to use an Fe-based amorphous alloy in consideration of the production cost. Fe-based amorphous alloy, for example, may use a Fe-Si-B-based amorphous alloy, in this case, Fe is preferably 70 ~ 90at%, and the sum of Si and B is 10 ~ 30at%. The higher the content of metals including Fe, the higher the saturation magnetic flux density. However, if the content of Fe element is excessive, it is difficult to form amorphous, so the content of Fe is preferably 70 to 90 at%. In addition, when the sum of Si and B is in the range of 10 to 30 at%, the amorphous forming ability of the alloy is the best. In order to prevent corrosion in this basic composition, corrosion-resistant elements such as Cr and Co may be added in an amount of 20 at% or less, and other metal elements may be included in small amounts as needed to impart different properties. In addition, the Fe-Si-B-based alloy may be, for example, a crystallization temperature of 508 ℃, a Curie temperature (Tc) of 399 ℃ may be used. However, the crystallization temperature may vary depending on the content of Si and B or other metal elements added in addition to the ternary alloy component and the content thereof.

In addition, the magnetic material included in an embodiment of the present invention may be a Fe-Si-B-Cu-Nb-based amorphous alloy. Copper included in the alloy improves the corrosion resistance of the alloy, prevents the crystal from increasing in size even when a crystal is formed, and at the same time improves magnetic properties such as magnetic permeability. The copper is preferably included in the alloy in an amount of 0.01 to 10 at%, and if it is included in less than 0.01 at%, the expression of the effect obtained due to copper may be insignificant, and if it exceeds 10 at%, an amorphous alloy is produced. There are problems that can be difficult. In addition, niobium (Nb) contained in the alloy can improve magnetic properties such as permeability, and is preferably contained in 0.01 to 10 at% in the alloy, and if it is contained in less than 0.01 at%, the effect obtained due to niobium may be insignificant, and if it exceeds 10at%, there is a problem that it may be difficult to produce an amorphous alloy.

The magnetic particles 10 may have an average particle diameter in the range of 0.1 to 10,000 μm. When the particle diameter of the magnetic particles is less than 0.1 μm, there is a problem in that it is difficult to manufacture a shielding unit having a desired level of magnetic permeability. In addition, when the particle diameter of the magnetic particles exceeds 10,000 μm, there is a possibility that it may be damaged by an external force, so that it may be difficult to maintain the initial design value when applied to the shielding unit. On the other hand, the average particle diameter of the magnetic particles means a volume average diameter measured by a laser diffraction particle size distribution analyzer.

In addition, the cross-section of the magnetic particles may have a polygonal shape such as a pentagon, a circular shape, an oval shape, or a partially mixed shape of a curved line and a straight line, in addition to a rectangular shape or a square shape. On the other hand, the shape of the magnetic particles shown in FIGS. 1 to 3 is a schematic diagram for more easily explaining the present invention, and may be different from the shape of the actual magnetic particle.

The magnetic particles 10 may be manufactured using a conventional technique for manufacturing magnetic particles, but preferably may be manufactured by mechanically pulverizing a magnetic material. In this case, the mechanical grinding may be performed by a ball milling, attrition milling, or jet milling process.

In addition, the magnetic material may have various bulk shapes, such as a rod shape, a plate shape, a ribbon, and the like. As an example of manufacturing such a magnetic material, first, nickel oxide, zinc oxide, copper oxide, cobalt oxide and triiron dioxide are mixed in a predetermined composition ratio to obtain a raw material mixture. In this case, the mixture may be mixed through dry mixing or wet mixing, and it is preferable that the particle diameter of the raw material to be mixed is 0.05 to 5 μm. Components such as nickel oxide and zinc oxide included in the raw material mixture may be in the form of itself or a complex oxide containing the above components, and in the case of cobalt oxide, it may be included in the raw material in the form of cobalt ferrite and tricobalt tetraoxide.

Next, the raw material mixture may be calcined to obtain a calcined material. Calcination is carried out to convert the raw material mixture into a form suitable for post-processing by promoting the pyrolysis of raw materials, homogenization of components, generation of ferrite, loss of ultrafine powder due to sintering, and growth of grains to an appropriate particle size. Such calcination is preferably performed at a temperature of 800 to 1100° C. for about 1 to 3 hours. The calcination may be carried out in an atmospheric atmosphere or an atmosphere having an oxygen partial pressure higher than that of the atmosphere.

Next, the obtained calcined material is pulverized to obtain a pulverized material. The pulverization is performed in order to break down the agglomeration of the plastic material to obtain a powder having an appropriate degree of sinterability. When the calcined material forms a large lump, after coarse pulverization, wet pulverization may be performed using a ball mill or an attritor. Wet grinding can be carried out until the average particle diameter of the pulverized material is preferably about 0.5 to 2 µm.

The adhesive 20 serves to fix and support each of the magnetic particles to maintain the magnetic field shielding sheet in a predetermined shape, to buffer external force applied to the magnetic particles, and to prevent moisture from penetrating and oxidizing the magnetic particles. is responsible for In particular, the adhesive has a very low specific resistance, so that magnetic loss due to eddy current can be prevented by acting as a dielectric for magnetic particles having large magnetic loss due to eddy current under a magnetic field.

In this case, the magnetic composite preferably contains 60 to 95 vol% of the magnetic particles and 5 to 40 vol% of the adhesive.

The adhesive 20 may be included without limitation as long as it has physical properties that can be adhered to each other by any one or more of an adhesive coated on another magnetic composite and heat, light, and pressure.

The adhesive 20 may be formed on the surface of the magnetic particles through the adhesive composition. Accordingly, the adhesive 20 may include a material included in the adhesive composition. Preferably, the adhesive composition may include any one or more of a natural polymer compound and a synthetic polymer compound, and may further include a curable component for crosslinking the polymer compound according to the type of the selected polymer compound.

In addition, the properties of the adhesive composition may be liquid, and for this purpose, the polymer compound may be liquid or dissolved or dispersed in a separate solvent to have a liquid state, or a polymer compound may be melted to have a liquid state, which is a specific polymer compound may vary depending on the type of

Among the high molecular compounds, the natural high molecular compound may include at least one of protein-based high molecular compounds such as glue and gelatin, carbohydrate-based high molecular compounds such as starch, cellulose and derivatives thereof, complex polysaccharides, and natural rubber-based compounds such as latex. .

In addition, the synthetic polymer compound may include at least one of a thermoplastic polymer compound, a thermosetting polymer compound, and a rubber compound. In this case, the thermoplastic polymer compound is polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyacrylonitrile resin, acrylonitrile-butadiene-styrene (ABS), styrene-acrylonitrile (SAN), acrylic resin , methacrylic resin, polyamide, thermoplastic polyester (Ex. polyethylene terephthalate (PET), polybutylene terephthalate (PBT), etc.), polycarbonate, polyphenylene sulfide resin, polyamideimide, polyvinyl butyral , polyvinyl formal, polyhydroxypolyether, polyether, polyphthalamide, fluorine-based resin (Ex. polytetrafluoroethylene (PTFE) and polychlorotrifluoroethylene (PCTFE)), phenoxy resin , a polyurethane-based resin, a nitrile-butadiene resin, and the like may be included. In addition, the thermosetting polymer compound may include one or more of a phenol-based resin (PE), a urea-based resin (UF), a melamine-based resin (MF), an unsaturated polyester-based resin (UP), and an epoxy resin. In addition, the rubber compound is styrene-butadiene rubber (SBR), polybutadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), polyisobutylene (PIB) rubber, acrylic rubber, fluororubber, silicone rubber and It may contain one or more types, such as chloroprene.

The adhesive composition included in one embodiment of the present invention is a synthetic polymer compound, more preferably a polymer compound, in order to further improve the flexibility of the magnetic field shielding unit through the improvement of the buffer action of the solidified adhesive and to act as a dielectric. The rubber compound may be included, and as an example, a terpolymer in which ethylene, propylene, and a diene monomer are copolymerized may be included in the rubber compound. In this case, the copolymerization molar ratio of each of the monomers may be changed according to the purpose, so the present invention is not particularly limited thereto.

In addition, the adhesive composition may further include a curable component. The curable component may be used without limitation if it is a known curable component capable of curing a selected specific polymer compound. As a non-limiting example, an amine compound, a phenol resin, an acid anhydride, an imidazole compound, a polyamine compound, a hydrazide compound, a dicyandiamide compound, etc. may be used alone or in combination of two or more. The aromatic amine compound curable component includes m-xylenediamine, m-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiethyldiphenylmethane, diaminodiphenyl ether, 1,3-bis (4-aminophenoxy)benzene, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]sulfone, 4,4'-bis (4-aminophenoxy)biphenyl, 1,4-bis(4-aminophenoxy)benzene, etc., and these may be used alone or in combination. In addition, phenolic resin curable components include phenol novolac resin, cresol novolak resin, bisphenol A novolak resin, phenol aralkyl resin, poly-p-vinylphenol t-butylphenol novolak resin, and naphthol novolak resin. , these may be used alone or in combination.

When a curable component is further included in the adhesive composition, the content of the curable component may vary depending on the type of the selected polymer compound and the type of the curable component. It may contain 5 to 60 parts by weight of the curable component. If the content of the curable component is less than 5 parts by weight, the curing reaction is weak and the desired level of flexural properties and tensile properties may not be expressed. Physical properties such as long-term storage may be deteriorated.

In addition, the adhesive composition included in an embodiment of the present invention may further include a solvent, a curing accelerator, and other additives in addition to the above-described polymer compound and curable component.

The solvent is a solvent used in a conventional coating composition, and may be used without limitation in the case of a solvent capable of dissolving or dispersing the above-described polymer compound, and non-limiting examples thereof include acetone, methyl ethyl ketone (MEK), methyl ketones such as isobutyl ketone (MIBK) and cyclohexanone; and ethers such as methyl cellosolve, ethylene glycol dibutyl ether and butyl acetate cellosolve. The amount of the solvent used is not particularly limited, but is preferably 10 to 500 parts by weight based on 100 parts by weight of the above-described polymer compound.

The curing accelerator is not particularly limited in the present invention as it may be determined by the specific type of the selected polymer compound and curable component, and non-limiting examples thereof include amine-based, imidazole-based, phosphorus-based, boron-based, phosphorus- There exist hardening accelerators, such as a boron type, and these can be used individually or in combination. The content of the curing accelerator is preferably about 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, per 100 parts by weight of the polymer compound.

Specifically, the other additives include a pH adjuster, an ion scavenger, a viscosity adjuster, a thixotropic agent, an antioxidant, a heat stabilizer, a light stabilizer, an ultraviolet absorber, a colorant, a dehydrating agent, a flame retardant, an antistatic agent, and a mildew inhibitor (防).黴劑), may include one or more types of preservatives, and in this case, the specific type of each additive may be used without limitation according to each additive, and the present invention is not particularly limited thereto.

In addition, when the adhesive composition includes a curable component, it is a one-component composition in which a polymer compound and a curable component are mixed, or a two-component type in which either component is mixed with the other component at the time for semi-curing and/or curing. It may be a composition, which may vary depending on the specific type of polymer compound, the type of curable component, and the specific curing method, so the present invention is not particularly limited thereto.

Meanwhile, the magnetic composite may be in a form in which adjacent magnetic composites are bonded to each other by applying a light beam. In this case, the adhesive composition may include an alicyclic epoxy resin, an epoxy resin including a glycidyl group-containing epoxy resin, a light-activated cationic polymerization catalyst, and a cationic polymerization inhibitor.

A specific method for coating the above-described adhesive composition on the surface of the magnetic particles may be used without limitation as long as it is a method of adding a known coating composition to the surface to be coated, and non-limiting examples thereof include blade coating, flow (flow) coating, casting (casting), printing method, transfer (transfer) method, brushing, dipping (dipping) or spraying (spraying) method, such as the above-described adhesive composition can be coated on the surface of the magnetic particles .

In this case, when the adhesive coated on the surface of the magnetic particles is formed from the curable composition, the state of the coated adhesive may not be a fully cured state. In the case of a fully cured state, adhesiveness may be deteriorated when adhering adjacent magnetic particles to each other by applying any one or more of heat, light, and pressure to the above-described magnetic composites.

Accordingly, the adhesive coated on the surface of the magnetic particles may be in a dry state, semi-solidified state, or solidified state.

In addition, the viscosity of the adhesive composition may be 10 ~ 50,000 cps, through which it can be uniformly coated with a very thin thickness on the magnetic sheet, there is an advantage that can form a thin coating layer after curing. If the viscosity is less than 10 cps, the composition may flow down from the coated surface, and if the viscosity exceeds 50,000 cps, there may be a problem of non-uniform coating thickness.

Thereafter, the magnetic composites coated with the adhesive coating may be adhered to each other by applying any one or more of heat, light, and pressure to prepare a magnetic field shielding sheet.

When applying heat to bond adjacent magnetic composites to each other, it is preferable to apply heat in a temperature range higher than the melting point of the adhesive and lower than the melting point of the magnetic particles. Accordingly, when heat is applied to the magnetic composite, the adhesives of the magnetic composites adjacent to each other may be melted and cured by thermal fusion or heat to be adhered. At this time, the heating may be performed for 1 second to 10 minutes at a temperature of 50 ~ 200 ℃. When the heating temperature is less than 50° C., adhesion between the magnetic composites may be reduced, and when the heating temperature exceeds 200° C., the structure of the magnetic composite may become unstable.

When light is applied to bond adjacent magnetic composites to each other, high-energy radiation, that is, UV radiation or sunlight, preferably light having a wavelength of 200 nm or more to 750 nm or less may be used as the light beam. In curing by UV curing, usually sufficient radiation dose is in the range of 80 mJ/cm ² or more and 5000 mJ/cm ² or less with a radiation intensity of 80 mW/cm ² or more to 3000 mW/cm ² or less. In addition, the radiation may optionally be conducted with the exclusion of oxygen, for example under an insoluble gas atmosphere or an oxygen depleted atmosphere. Suitable insoluble gases are preferably nitrogen, carbon dioxide, inert gases or combustion gases. Irradiation can also be carried out by coating a dry layer with a medium that transmits radiation. Examples of this are synthetic films, glass or liquids such as water. When using light rays, there is an advantage that the process can be carried out at room temperature. In this case, the time for applying the light may be 10 to 30 minutes. When the time for applying the light beam is less than 10 minutes, the adhesive strength between the magnetic composites may decrease, and if the time for applying the light beam exceeds 30 minutes, it may cause a change in properties of the adhesive.

In addition, in the case of bonding adjacent magnetic composites to each other through pressure, the adhesives of the adjacent magnetic composites are compressed to each other by pressure. At this time, it is preferable to apply a pressure in the range of 1 to 5 MPa. When the applied pressure is less than 1 MPa, the adhesive force between the magnetic composites may be reduced. Also, when the applied pressure exceeds 5 MPa, the magnetic particles may be damaged.

Accordingly, the adhesives of adjacent magnetic composites are adhered to each other in any one of thermal bonding, chemical bonding, and compression bonding.

In this case, the space factor of the magnetic particles may be 95% or more. When the space factor of the magnetic particles is less than 95%, magnetic properties such as magnetic permeability in the magnetic field shielding sheet may be deteriorated.

Since the magnetic field shielding sheet is formed by thermally fusion, pressing, or chemically bonding the adhesive of the magnetic composite to each other without preparing a slurry for manufacturing the sheet as in the conventional technology, the density of magnetic particles in the sheet can be improved, and the magnetic field in the sheet There is an effect that the particle distribution can be made uniform. In addition, as described above, the adhesive has a very low specific resistance and acts as a dielectric for magnetic particles having a large magnetic loss due to an eddy current under a magnetic field, thereby preventing magnetic loss due to an eddy current.

Meanwhile, An antenna module according to an embodiment of the present invention includes a magnetic field shielding unit including a magnetic field shielding sheet manufactured by the above-described method for manufacturing a magnetic field shielding sheet, and a radiator formed on at least one surface of the magnetic shielding unit.

3A and 3B , the magnetic field shielding unit 100 ′, 100 ″ according to an embodiment of the present invention may further include an adhesive member 130 disposed under the magnetic field shielding sheet 110 . and may further include a protection member 140 disposed thereon.

First, the protection member 140 performs a function of protecting the magnetic field shielding unit from external physical and chemical influences. The magnetic shielding unit can be attached to the substrate through the adhesive of

The protective member 140 may be a protective film typically provided in a magnetic field shielding unit, and has enough heat resistance and external force to withstand the heat or external force applied in the crushing process of the magnetic sheet or the attachment process of the shielding unit. A protective member made of a material that has mechanical strength and chemical resistance sufficient to protect the magnetic field shielding sheet 110 against physical and chemical stimuli may be used without limitation. Non-limiting examples thereof include polyethylene, polypropylene, polyimide, cross-linked polypropylene, nylon, polyurethane-based resin, acetate, polybenzimidazole, polyimide amide, polyetherimide, polyphenylene sulfide (PPS). Polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT) and polybutylene terephthalate (PBT), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE) and polychlorotrifluoroethylene ( PCTFE), polyethylene tetrafluoroethylene (ETFE), etc. films can be used individually or in combination.

Also, the protective member 140 may have a thickness of 1 to 100 μm, preferably 10 to 30 μm, but is not limited thereto.

In this case, the plurality of magnetic shielding sheets 110 may be stacked to form a shielding unit. As such, the magnetic field shielding unit having a plurality of magnetic field shielding sheets 110 is suitable for expressing better properties than the magnetic field shielding unit having only a single-layered magnetic field shielding sheet, such as the magnetic field shielding unit according to FIG. 3A or 3B. can That is, a method of increasing the magnetic permeability of the magnetic field shielding unit includes a method of using a magnetic material having excellent permeability at a desired frequency and/or a method of increasing the thickness of the magnetic field shielding sheet, but in order to increase the thickness of the magnetic field shielding sheet, a single layer If the thickness of the magnetic material sheet is increased to a certain level or more, the surface portion and the inside of the sheet are not fired uniformly and identically in the firing process. There is a limit to the increase in permeability through the increase in thickness. On the other hand, if a plurality of magnetic field shielding sheets themselves are provided, a high permeability increase effect can be achieved through an increase in the overall thickness of the magnetic field shielding sheet, and the magnetic field shielding unit having the stacked magnetic field shielding sheets provides antenna characteristics for the intended purpose. Further, it is possible to significantly improve signal transmission/reception efficiency and transmission/reception distance.

When a plurality of magnetic field shielding sheets 110 are provided in the magnetic field shielding unit, 3 to 10, more preferably 3 to 8 magnetic field shielding sheets, are preferably provided. If the number of laminated magnetic field shielding sheets exceeds 10, the degree of improvement in the characteristics of the desired antenna may be insignificant. When this is done, the antenna characteristics may not be improved to a desired level because it is insignificant.

In addition, an electromagnetic wave shielding sheet, a heat dissipation layer, and/or a composite layer in which these functions are laminated on the upper portion of the protective member 140 and/or the lower portion of the adhesive member 130 of the magnetic shielding unit, or a composite layer in which these functions are combined into one layer A functional layer such as For example, a metal foil such as copper or aluminum having excellent thermal conductivity and conductivity may be attached to the upper portion of the protective member 140 through an adhesive or double-sided tape. Or Cu, Ni, Ag, Al, Au, Sn, Zn, Mn, Mg, Cr, Tw, Ti or a combination of these metals on the protective member 140, sputtering, vacuum deposition, chemical vapor deposition, etc. known methods may be deposited to form a metal thin film. When the functional layer is provided through an adhesive, the adhesive may be a known adhesive, and non-limiting examples thereof include an acrylic adhesive, a urethane-based adhesive, and an epoxy-based adhesive. On the other hand, the adhesive can be used by imparting heat dissipation performance, and for this purpose, a known filler such as nickel, silver, or carbon material can be mixed with the adhesive, and the content of the filler can be the content of the filler in a known heat dissipation adhesive. Accordingly, the present invention is not particularly limited thereto.

The thickness of the functional layer may be 5 ~ 100㎛, more preferably, it is preferably formed to a thickness of 10 ~ 20㎛ for thinning the magnetic field shielding unit.

In addition, the radiator may be an antenna coil wound so that the coil has a constant inner diameter or an antenna pattern printed with an antenna pattern on a substrate. do not limit

Furthermore, the antenna module according to an embodiment of the present invention described above may be provided in a portable device as a short-distance communication receiving module for receiving transmitted data or a wireless power receiving module for receiving transmitted wireless power/data, Through this, wireless charging efficiency, data reception efficiency and charging distance or data reception distance can be significantly improved.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments presented herein, and those skilled in the art who understand the spirit of the present invention can add components within the scope of the same spirit. , changes, deletions, additions, etc. may easily suggest other embodiments, but this will also fall within the scope of the present invention.

10: magnetic particles 20: adhesive
30: pores 110: magnetic field shielding sheet
130: adhesive member 140: protective member

Claims (16)

a plurality of magnetic particles; and a rubber compound including a terpolymer copolymerized with ethylene, propylene and a diene monomer for bonding the magnetic particles to each other so that the plurality of magnetic particles have a sheet shape, and a curable component for crosslinking the rubber compound. ; including,
The adhesive contains 5 to 60 parts by weight of a curable component for crosslinking the rubber compound with respect to 100 parts by weight of the rubber compound, which is a terpolymer in which ethylene, propylene and diene monomers are copolymerized,
The adhesive is a magnetic field shielding sheet that is included in a volume of less than 5% based on the total volume. A plurality of magnetic composites including an adhesive disposed to surround at least a portion of the surface of the magnetic particles are adhered to each other through the adhesive to adjacent magnetic composites, and the adhesive is included in a volume of less than 5% based on the total volume, The adhesive is a magnetic field shielding sheet comprising 5 to 60 parts by weight of a curable component for crosslinking the rubber compound with respect to 100 parts by weight of the rubber compound including a terpolymer in which ethylene, propylene and a diene monomer are copolymerized. 3. The method of claim 1 or 2,
The adhesive is a magnetic shielding sheet adhered in the form of at least one of chemical bonding and thermal bonding. 3. The method of claim 1 or 2,
The magnetic particles include a soft magnetic material, the soft magnetic material is a metal soft magnetic material comprising at least one of an amorphous alloy and a nanocrystalline alloy, or a magnetic field shielding sheet comprising ferrite. 5. The method of claim 4,
The metal soft magnetic material is a Ni-Co-based alloy, Fe-Ni-based alloy, Fe-Cr-based alloy, Fe-Al-based alloy, Fe-Si-based alloy, Fe-Si-B-based alloy, Fe-Si-B-Cu -Contains at least one selected from the group consisting of Nb-based alloys,
The ferrite is selected from the group consisting of Mn-Zn-based ferrite, Ni-Zn-based ferrite, Ni-Co-based ferrite, Mg-Zn-based ferrite, Cu-Zn-based ferrite, and cobalt-substituted Y-type or Z-type hexagonal ferrite 1 Magnetic field shielding sheet containing more than one species. delete 3. The method of claim 1 or 2,
A magnetic field shielding sheet having an area ratio of the magnetic particles of 95% or more. 3. The method of claim 1 or 2,
A magnetic shielding sheet with a porosity of 5% or less. A magnetic field shielding unit comprising the magnetic field shielding sheet according to claim 1 or 2; and
An antenna module comprising a; a radiator disposed on at least one surface of the magnetic field shielding sheet. 10. The method of claim 9,
The magnetic shielding unit is an antenna module in which a plurality of magnetic shielding sheets are stacked.
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