KR101964911B1 - Method for preparing conductive magnet composite sheet and antenna device - Google Patents

Abstract

According to the embodiment, a green sheet is prepared by coating and drying a magnetic slurry in which a magnetic powder is mixed with a thermosetting binder resin and a solvent on a conductive foil, and thereafter, by applying heat and pressure, the magnetic sheet and the conductive foil The magnetic composite sheet can be easily produced. Further, by laminating the additional conductive foil on the green sheet and applying heat and pressure, it is possible to easily produce the conductive magnetic composite sheet having the conductive foil on both sides.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a conductive magnetic composite sheet,

Embodiments relate to a conductive magnetic composite sheet, an antenna element, and a method of manufacturing the same, which can be used in fields such as near field communication, wireless charging, and magnetic security transmission.

Recently, mobile devices such as mobile phones, tablet PCs and notebook PCs have realized functions such as near field communication (NFC), wireless power consortium (WPC) and magnetic secure transmission (MST) Is mounted. However, there are other parts of the metal material inside the mobile device, and when an alternating magnetic field formed inside the device is applied to such a metal part, eddy current is generated, thereby deteriorating the performance of the antenna, .

In order to solve this problem, a high permeability ferrite sheet is attached to the other surface of a general circuit board (antenna) such as a polyimide substrate having an antenna pattern layer formed on one surface thereof and used as a composite antenna element. This is based on the principle that a magnetic body such as a ferrite sheet can focus the magnetic flux of the antenna to prevent magnetic field penetration into the metal surface and generation of eddy current, and to improve the operating characteristics.

Korean Patent Laid-Open Publication No. 2013-50633

When a magnetic sheet is bonded to a circuit board as an antenna element and mounted in a mobile device, the efficiency of the inner space of the mobile device, which is limited by mounting various components, is lowered. In addition, if adhesion between the circuit board and the magnetic sheet is poor, peeling may occur.

An attempt has been made to manufacture an antenna element by forming an antenna pattern by etching a magnetic sheet with a conductive foil laminated on the magnetic sheet. For this purpose, a magnetic slurry is generally coated on a carrier film and dried to form a green sheet, and the green sheet is lapped with a conductive foil to prepare a conductive magnetic composite sheet.

However, in the above-described method, quality deterioration or partial hardening may occur in the course of separating the green sheet from the carrier film and transferring the green sheet for bonding with the conductive foil, and as a result, Can be degraded. In addition, the above general method has a possibility to further reduce the cost by simplifying the procedure of the process.

Accordingly, it is an object of the present invention to provide a method for manufacturing a conductive magnetic composite sheet having magnetic properties that can be used for a combination of NFC, WPC, and MST, and having excellent interlayer bonding force through a simplified procedure. Another object of the present invention is to provide a method of manufacturing an antenna element using the conductive magnetic composite sheet according to another embodiment.

According to one embodiment, there is provided a method of manufacturing a magnetic recording medium, comprising: preparing a magnetic slurry comprising magnetic powder, a thermosetting binder resin, and a solvent; Coating the magnetic slurry on the first conductive foil and drying to obtain a composite green sheet; And a step of applying heat and pressure to the composite green sheet to cure the binder resin to form a magnetic sheet bonded to the first conductive foil.

According to another embodiment, there is provided a magnetic recording medium comprising: a magnetic slurry comprising a magnetic powder, a thermosetting binder resin, and a solvent; Coating the magnetic slurry on the first conductive foil and drying to obtain a composite green sheet; And placing a second conductive foil on the composite green sheet and applying heat and pressure to cure the binder resin to form a magnetic sheet bonded with the first conductive foil and the second conductive foil. A method for producing a magnetic composite sheet is provided.

According to another embodiment, there is provided a method of manufacturing a magnetic recording medium, comprising: preparing a magnetic slurry comprising magnetic powder, a thermosetting binder resin, and a solvent; Coating the magnetic slurry on the first conductive foil and drying to obtain a composite green sheet; Obtaining a conductive magnetic composite sheet by applying heat and pressure to the composite green sheet to cure the binder resin to form a magnetic sheet bonded to the first conductive foil; And etching the first conductive foil of the conductive magnetic composite sheet to form a first antenna pattern.

According to another embodiment, there is provided a method of manufacturing a magnetic recording medium, comprising: preparing a magnetic slurry comprising magnetic powder, a thermosetting binder resin, and a solvent; Coating the magnetic slurry on the first conductive foil and drying to obtain a composite green sheet; A second conductive foil is disposed on the composite green sheet, and heat and pressure are applied to cure the binder resin to form a magnetic sheet bonded with the first conductive foil and the second conductive foil to obtain a conductive magnetic composite sheet step; And etching the first conductive foil and the second conductive foil of the conductive magnetic composite sheet to form a first antenna pattern and a second antenna pattern, respectively.

According to this embodiment, a conductive magnetic composite sheet having excellent magnetic properties at the frequencies of NFC, WPC, and MST and excellent interlayer bonding force between the magnetic sheet and the conductive foil can be produced. In particular, the conductive magnetic composite sheet produced according to the embodiment may not suffer delamination even under various environmental changes such as heat treatment at a high temperature in order to apply it to a product.

Specifically, a green sheet is prepared by coating and drying a magnetic slurry obtained by mixing a magnetic powder with a thermosetting binder resin and a solvent on a conductive foil, and then applying heat and pressure to form a conductive magnetic composite The sheet can be easily produced. Further, by laminating the additional conductive foil on the green sheet and applying heat and pressure, it is possible to easily produce the conductive magnetic composite sheet having the conductive foil on both sides.

Particularly, according to the embodiment, since the magnetic slurry is applied directly on the conductive foil, a carrier film for manufacturing the green sheet is not required, and the step of laminating the magnetic sheet and the conductive foil can be reduced. Further, according to the embodiment, the binder resin in the green sheet formed on the conductive foil is cured by heat and pressure to be pressed with the conductive foil while forming the magnetic sheet, so that the bonding force between the magnetic sheet and the conductive foil can be further improved .

Accordingly, the conductive magnetic composite sheet manufactured according to the embodiment can be usefully used for manufacturing antenna elements having NFC, WPC, and MST functions.

FIGS. 1 to 3 illustrate a process for manufacturing a conductive magnetic composite sheet according to an embodiment.
Figs. 4 and 5 show a roll-to-roll process and a batch process, respectively.
6A and 6B show cross sections of the conductive magnetic composite sheet according to the embodiment.
7 shows a cross-sectional view of an antenna element according to an embodiment.
8 to 10 are top views of an antenna element according to an embodiment.
11A and 11B are a plan view and a cross-sectional view of the antenna element according to the embodiment.
12A to 12C show a manufacturing process of an antenna element according to an embodiment.
13 and 14 are diagrams schematically illustrating signal transmission / reception between the antenna element and the external terminal according to the embodiment.
Fig. 15 shows heat treatment conditions at the time of the reflow test.

In the following description of the embodiments, in the case where each layer, foil or sheet is described as being formed "on" or "under" of each layer, foil or sheet, on "and" under " all include being formed either "directly" or "indirectly" unless otherwise stated. In addition, the upper or lower reference of each component is described with reference to the drawings. In addition, sizes, intervals, and the like may be exaggeratedly displayed for the sake of clarity in the accompanying drawings, and details obvious to those skilled in the art may be omitted.

A method of manufacturing a conductive magnetic composite sheet according to an embodiment includes the steps of: preparing a magnetic slurry including magnetic powder, a thermosetting binder resin, and a solvent; Coating the magnetic slurry on the first conductive foil and drying to obtain a composite green sheet; And applying heat and pressure to the composite green sheet to cure the binder resin to form a magnetic sheet bonded to the first conductive foil.

A method for producing a conductive magnetic composite sheet according to another embodiment includes the steps of: preparing a magnetic slurry containing a magnetic powder, a thermosetting binder resin, and a solvent; Coating the magnetic slurry on the first conductive foil and drying to obtain a composite green sheet; And placing a second conductive foil on the composite green sheet and curing the binder resin by applying heat and pressure to form a magnetic sheet bonded with the first conductive foil and the second conductive foil.

Each step will be described in detail below.

First, a magnetic slurry containing a magnetic powder, a thermosetting binder resin and a solvent is prepared.

That is, the magnetic slurry can be prepared by dispersing the magnetic powder in a binder resin and a solvent.

As a concrete example, the magnetic slurry may be prepared by mixing a polyurethane resin, an isocyanate curing agent, and an epoxy resin to prepare a thermosetting binder resin; And mixing the magnetic powder and the organic solvent in the binder resin.

As a more specific example, a magnetic powder can be firstly added to a solvent together with a polyurethane resin, an epoxy resin and an isocyanate curing agent and dispersed by a dispersing machine (planetary mixer, homo mixer, no-bead mill, etc.) have.

The magnetic slurry may have a viscosity of about 100 to 10,000 cPs, or may have a viscosity of 100 to 5,000 cPs, 1,000 to 10,000 cPs, or 2,000 to 5,000 cPs.

Hereinafter, the components contained in the magnetic slurry will be described in detail.

The magnetic powder may be an oxide magnetic powder such as ferrite (Ni-Zn type, Mg-Zn type, Mn-Zn type ferrite, etc.); Metal magnetic powders such as permalloy, sendust, Fe-Si-Cr alloys and Fe-Si-nanocrystals; Or a mixed powder thereof. For example, the magnetic powder may be a sandstone powder having an Fe-Si-Al alloy composition.

As a specific example, the magnetic powder may have a composition represented by the following formula (1).

[Chemical Formula 1]

Fe _1-abc Si _a X _b Y _c

Wherein X is Al, Cr, Ni, Cu, or a combination thereof; Y is Mn, B, Co, Mo, or a combination thereof; 0.01? A? 0.2, 0.01? B? 0.1, and 0? C? 0.05.

The particle size of the magnetic powder may range from about 3 nm to about 1 mm. More specifically, the particle size of the magnetic powder may be in the range of about 1 to 300 mu m, about 1 to 50 mu m, or about 1 to 10 mu m. When the average particle diameter of the magnetic powder is within the above-described preferable range, it is possible to prevent short-circuiting when vias are formed in the magnetic sheet while exhibiting sufficient magnetic properties.

The magnetic powder may be coated with a functional material. For example, the magnetic powder may be one having an anti-corrosive coating or an insulating coating on the surface of each particle.

The individual particles of the magnetic powder may thus consist of a core and a shell surrounding the surface of the core. Wherein the core comprises an oxide magnetic material such as ferrite; Metal magnetic materials such as permalloy, sandust, Fe-Si-Cr alloy and Fe-Si-nano-crystal; Or a mixture thereof. In addition, the shell may contain a polymer resin having an anti-rusting property and / or an insulating property. The thickness of the shell may be in the range of 0.1 to 20 占 퐉, or in the range of 1 to 10 占 퐉.

As the binder resin, a thermosetting resin is used.

As the resin that can be cured and exhibit adhesiveness, one or more functional groups or sites capable of being cured by heat such as a glycidyl group, an isocyanate group, a hydroxyl group, a carboxyl group, an amide group, or the like; Or at least one functional group or moiety capable of being cured by an active energy such as an epoxide group, a cyclic ether group, a sulfide group, an acetal group or a lactone group Can be used. Such a functional group or moiety may be, for example, an isocyanate group (-NCO), a hydroxy group (-OH), or a carboxyl group (-COOH).

Specifically, examples of the curable resin include, but are not limited to, a polyurethane resin, an acrylic resin, a polyester resin, an isocyanate resin or an epoxy resin having at least one functional group or moiety as described above.

According to one embodiment, the binder resin may include a polyurethane resin, an isocyanate curing agent, and an epoxy resin.

The polyurethane resin may include repeating units represented by the following general formulas (2a) and (2b).

[Chemical Formula 2a] [Chemical Formula 2b]

Wherein R ₁ and R ₃ are each independently a C _1-5 alkylene group, urea or ether group; R ₂ and R ₄ are each independently a C _1-5 alkylene group; Wherein each C _1-5 alkylene group has one or more substituents selected from the group consisting of halogen, cyano, amino and nitro.

The polyurethane resin may contain the repeating unit represented by the formula (2a) and the repeating unit represented by the formula (2b) in a molar ratio of 1:10 to 10: 1.

The polyurethane resin may have a number average molecular weight in the range of about 500 to 50,000 g / mol, in the range of about 10,000 to 50,000 g / mol, or in the range of about 10,000 to 40,000 g / mol.

The isocyanate-based curing agent may be an organic diisocyanate.

For example, the isocyanate-based curing agent may be an aromatic diisocyanate, an aliphatic diisocyanate, an alicyclic diisocyanate, or a mixture thereof.

The aromatic diisocyanate may be, for example, a diisocyanate having 1 to 2 C _6-20 aryl groups, specifically 1,5-naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4 ' -Diphenyl-dimethylmethane diisocyanate, 4,4'-benzyl isocyanate, dialkyl-diphenylmethane diisocyanate, tetraalkyl-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, Diisocyanate, tolylene diisocyanate, xylene diisocyanate, and the like.

The alicyclic diisocyanate, for example, one or two C _{6 ~ 20} may be a diisocyanate having a cycloalkyl group, in particular cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexyl methane -4 , 4'-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate, and the like.

Preferably, the isocyanate-based curing agent may be an alicyclic diisocyanate, particularly isophorone diisocyanate.

Examples of the epoxy resin include bisphenol-type epoxy resins such as bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, tetrabromobisphenol A epoxy resin and the like; A spirocyclic epoxy resin; Naphthalene type epoxy resin; Biphenyl type epoxy resins; Terpene type epoxy resin; Glycidyl ether type epoxy resins such as tris (glycidyloxyphenyl) methane, tetrakis (glycidyloxyphenyl) ethane and the like; Glycidylamine-type epoxy resins such as tetraglycidyldiaminodiphenylmethane; Novolak type epoxy resins such as cresol novolak type epoxy resin, phenol novolak type epoxy resin,? -Naphthol novolak type epoxy resin, brominated phenol novolak type epoxy resin and the like. These epoxy resins may be used singly or in combination of two or more.

Among them, bisphenol A type epoxy resin, cresol novolak type epoxy resin, or tetrakis (glycidyloxyphenyl) ethane type epoxy resin is preferably used in view of adhesion and heat resistance.

The epoxy resin may have an epoxy equivalent of about 80 to 1,000 g / eq, or about 100 to 300 g / eq. In addition, the epoxy resin may have a number average molecular weight ranging from about 10,000 to about 50,000 g / mol.

As the solvent contained in the magnetic slurry, an organic solvent may be used.

For example, as the solvent, at least one organic solvent selected from the group consisting of aromatic hydrocarbons, aliphatic ketones and aliphatic esters can be used. More specifically, at least one solvent selected from the group consisting of toluene, 2-butanone, and n-butyl acetate may be used.

In addition, the magnetic slurry 102 may further include a corrosion inhibitor. Examples of the rust inhibitor include an organic rust inhibitor and an inorganic rust inhibitor.

Specific examples of the organic rust inhibitor include amines, urea, mercaptobenzothiazole (MBT), benzotriazole, tolyltriazole, aldehydes, heterocyclic nitrogen compounds, sulfur-containing compounds, acetylenic compounds, ascorbic acid , Succinic acid, tryptamine, caffeine and the like.

More specifically, the rust inhibitor may be selected from the group consisting of N-benzyl-N, N-bis [(3,5-dimethyl-1H-pyrazol- (Benzimidazol-2-ylmethyl) amine, N- (2-furfuryl) -p-toluidine, N- (5- Chloro-2-furyl) -p-toluidine, N- (5-nitro-2-furyl) (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, or a mixture of these ≪ / RTI >

The magnetic slurry may contain 20 to 90% by weight of the solvent, or 20 to 80% by weight, 30 to 90% by weight, 20 to 70% by weight, 40 to 90% by weight based on the total weight of the magnetic slurry, 90% by weight.

As a preferred example, the magnetic slurry may contain at least one organic solvent selected from the group consisting of aromatic hydrocarbons, aliphatic ketones and aliphatic esters in an amount of 20 to 90% by weight based on the total weight of the magnetic slurry .

The magnetic slurry may contain the magnetic powder in an amount of 50% by weight or more, or 70% by weight or more, based on the weight of the solid content excluding the solvent. For example, the magnetic slurry may contain 50 to 95 wt%, 70 to 95 wt%, 70 to 90 wt%, 75 to 90 wt%, 75 to 95 wt%, 80 to 95 wt%, or 80 to 95 wt% By weight to 90% by weight.

The magnetic slurry may contain the binder resin in an amount of 5 to 40% by weight, 5 to 20% by weight, 5 to 15% by weight, or 7 to 15% by weight based on the weight of the solid content excluding the solvent .

The magnetic slurry may contain, as the binder resin, 6 to 12 wt% of a polyurethane resin, 0.5 to 2 wt% of an isocyanate curing agent, and 0.3 to 1.5 wt% of an epoxy resin Resin.

As an example, the magnetic slurry contains the magnetic powder in an amount of 70 to 90% by weight based on the weight of the solid content excluding the solvent, and the binder resin includes 6 to 12% by weight of the polyurethane resin; 0.5 to 2% by weight of an isocyanate-based curing agent; And 0.3 to 1.5% by weight of an epoxy resin.

The magnetic slurry is coated on the first conductive foil and dried to form a composite green sheet.

Referring to FIG. 1, when the coating of the magnetic slurry is performed by a roll-to-roll process, the magnetic slurry 102 is coated on the first conductive foil 210 conveyed by the carrier film 400 by the coater 500 Coated and dried to prepare a green sheet (101). At this time, the green sheet 101 includes an unhardened or semi-hardened binder resin 121. As a result, a composite green sheet in which the green sheet 101 in which curing of the binder resin is not completed is laminated on the first conductive foil 210 can be obtained.

The first conductive foil may comprise a conductive material. For example, the first conductive foil may comprise a conductive metal. That is, the first conductive foil may be a metal layer. For example, the first conductive foil may comprise at least one metal selected from the group consisting of copper, nickel, gold, silver, zinc and tin. Specifically, the first conductive foil may be a metal foil. More specifically, the first conductive foil may be a copper foil (copper foil).

The thickness of the first conductive foil may be about 6 to 200 microns, and more specifically about 10 to 150 microns, about 10 to 100 microns, or about 20 to 50 microns.

The coating of the magnetic slurry can be carried out using equipment such as a lip coater, a doctor blade, and a comma coater.

The coating of the magnetic slurry can be performed at a speed of 0.5 to 5 m / min or at a speed of 0.5 to 3 m / min, 1 to 5 m / min, or 2 to 4 m / min.

The coating rate can be adjusted according to the thickness of the green sheet to be formed on the conductive foil

The magnetic slurry coated on the first conductive foil is then dried.

The drying of the magnetic slurry may be performed at a temperature in the range of 20 to 150 ° C, or in the range of 50 to 150 ° C, in the range of 20 to 100 ° C, or in the range of 50 to 100 ° C.

Through the drying, the solvent in the magnetic slurry can be removed to form a composite green sheet.

As a preferred example, the coating of the magnetic slurry is carried out at a speed of 0.5 to 5 m / min using a lip coater, a doctor blade or a comma coater, and the drying of the magnetic slurry is performed at a temperature of 20 to 150 ° C, By removing the solvent in the slurry, a composite green sheet can be formed.

Thereafter, heat and pressure are applied to the composite green sheet to cure the uncured or semi-cured binder resin in the green sheet to form a magnetic sheet bonded to the first conductive foil.

Alternatively, a second conductive foil may be further disposed on the composite green sheet, and heat and pressure may be applied to bond the uncured or semi-cured binder resin in the green sheet to the first conductive foil and the second conductive foil To form a magnetic sheet. Wherein the specific components and thickness of the second conductive foil may be substantially the same as those illustrated for the first conductive foil.

That is, as shown in FIGS. 2 and 3, the magnetic sheet 100 in which the hardening of the binder resin 120 is completed by heat and pressure is formed, and the first conductive foil 210 and the second conductive foil 220 may be bonded to the magnetic sheet 100. Since the first conductive foil 210 and the second conductive foil 220 are bonded to the magnetic sheet 100 by thermal curing, the bonding force between the magnetic sheet and the conductive foil can be excellent. Particularly, since the magnetic sheet and the conductive foil are bonded while the binder resin is cured at the same time as the pressing, the bonding force can be further improved. Accordingly, the magnetic sheet and the conductive foil do not require a separate adhesive layer.

The step of applying heat and pressure may be performed at a pressure of 1 to 100 MPa and a temperature of 100 to 300 ° C. Alternatively, the step of applying heat and pressure may be performed at a pressure of 5 to 30 MPa and a temperature of 150 to 200 ° C. In addition, the process of applying heat and pressure to the magnetic sheet and the conductive foil may be performed for about 0.1 to 5 hours. As a result, the magnetic sheet can be bonded in direct contact with the first conductive foil and the second conductive foil.

The step of applying heat and pressure may be performed by a roll-to-roll process or a batch process.

As shown in FIG. 4, the step of applying heat and pressure may proceed to a roll-to-roll process.

In a roll-to-roll process, a composite green sheet having a green sheet 101 formed on a first conductive foil is passed through a roll 600, or a second conductive foil 210, 220 is further provided on the composite green sheet And the roll 600 is passed while being laminated. At this time, the roll itself is heated, and the roll can simultaneously apply heat and pressure to the laminate. As a result, the binder resin in the green sheet 101 is cured to form the magnetic sheet 100, and the first conductive foil 210 and the second conductive foil 220 are bonded to the magnetic sheet 100 .

In the roll-to-roll process, the temperature of the roll may be about 100 to 300 ° C. Also, the pressure of the roll may be about 1 to 100 MPa. The roll used in the roll-to-roll process may be about 1 to 20 pairs. The moving speed of the laminate may be about 0.1 to 10 m / min.

According to a specific example, the step of applying heat and pressure is performed by a roll-to-roll process, wherein the roll-to-roll process is carried out using rolls of 2 to 10 pairs at a roll temperature of 150 to 200 ° C, Pressure and a speed of 1 to 5 m / min.

As shown in FIG. 5, the step of applying heat and pressure may proceed to a batch process. Specifically, a composite green sheet in which the green sheet and the conductive foil are laminated is laminated in several stages, and then heat and pressure are applied to the entire laminate at once. As a result, the cured magnetic sheet 100 having the binder resin is formed, and the first conductive foil 210 and the second conductive foil 220 are laminated to the magnetic sheet 100 ) Can be obtained.

In the arranging step, the heat treatment temperature may be about 100 to 300 ° C. In addition, the pressure applied to the multi-layer stacked body may be about 1 to 100 MPa. In addition, the time for applying heat and pressure may be about 0.1 to 5 hours.

The conductive magnetic composite sheet produced by the above method comprises a magnetic sheet and a conductive foil disposed on at least one surface of the magnetic sheet.

A conductive composite sheet according to one embodiment includes a magnetic sheet including magnetic powder and a binder resin, and a first conductive foil disposed in contact with one surface of the magnetic sheet.

A conductive composite sheet according to another embodiment includes a magnetic sheet including a magnetic powder and a binder resin, and a first conductive foil disposed in contact with one surface of the magnetic sheet; And a second conductive foil disposed in contact with the other surface of the magnetic sheet.

6A and 6B show cross sections of the conductive magnetic composite sheet according to the embodiment.

Referring to FIG. 6B, the conductive composite sheet according to the embodiment includes a magnetic sheet 100, a first conductive foil 210, and a second conductive foil 220. At this time, the magnetic sheet 100 directly contacts the first conductive foil 210 and the second conductive foil 220, and there is no separate adhesive layer therebetween.

The magnetic sheet 100 includes a magnetic powder 110 and a cured binder resin 120.

Hereinafter, each component of the conductive magnetic composite sheet will be described in detail.

The magnetic sheet includes a magnetic powder and a binder resin.

That is, the magnetic sheet may be a polymeric magnetic sheet (PMS).

Specifically, the magnetic sheet may be an unfired cured sheet containing a magnetic powder and a binder resin. The magnetic sheet may be a flexible magnetic sheet.

The thickness of the magnetic sheet formed by applying the heat and pressure may be about 10-3000 [mu] m.

More specifically, the thickness of the magnetic sheet may be about 10 to 500 μm, about 40 to 500 μm, about 40 to 250 μm, about 50 to 250 μm, about 50 to 200 μm, or about 50 to 100 μm.

The magnetic sheet is excellent in magnetic properties, flexibility, heat resistance, chemical resistance, and insulation.

For example, the magnetic sheet may have a magnetic permeability of 100 to 300 for an alternating current of 3 MHz frequency, a magnetic permeability of 80 to 270 for an alternating current of 6.78 MHz, and a magnetic permeability of 60 to 100 for an alternating current of 13.56 MHz, Lt; RTI ID = 0.0 > 250. ≪ / RTI >

Alternatively, the magnetic sheet may have a permeability of about 190 to 250 for an alternating current of 3 MHz frequency, a permeability of about 180 to 230 for an alternating current of 6.78 MHz, and a permeability of about 140 Lt; RTI ID = 0.0 > 180. ≪ / RTI >

In addition, the magnetic sheet may be flexible enough to be applied to various apparatuses. For example, the magnetic sheet may not be cut even after 100, 1,000, or 10,000 bends in an MIT folding test at 90 ° and 35 RPM conditions. Further, the magnetic sheet may have a permeability change of about 10% or less, or about 5% or less after 100 times, 1,000 times, or 10,000 times of bending in an MIT bending test under the conditions of 90 ° and 35 RPM.

Further, the magnetic sheet may have heat resistance capable of withstanding high temperature conditions. For example, the magnetic sheet may have a volume change of less than about 25%, less than 15%, less than 10%, or less than about 5% when heat treated for about 30 minutes at about 150 ° C. Further, the magnetic sheet may have a permeability change of about 25% or less, 15% or less, 10% or less, or about 5% or less when the magnetic sheet is heat-treated at about 150 ° C for about 30 minutes.

The magnetic sheet was heated at a constant speed for 200 seconds from 30 ° C to 240 ° C and then heat-treated at a constant rate from 240 ° C to 130 ° C for 100 seconds. When repeated, it can have a thickness variation of about 5% or less and a permeability variation of about 5% or less. Specifically, when the heat treatment condition is repeated twice, the magnetic sheet may have a thickness variation of about 3% or less and a permeability variation of about 3% or less, more specifically, a thickness variation of about 1% %. ≪ / RTI >

In addition, the magnetic sheet may have chemical resistance that can withstand various environments. For example, the magnetic sheet has a thickness change of 5% or less and a permeability change of 5% or less when immersed in a 2N hydrochloric acid solution for 30 minutes and has a thickness change of 5% or less when immersed in 2N sodium hydroxide solution for 30 minutes and And may have a permeability change of 5% or less. Specifically, the magnetic sheet had a thickness change of 3% or less and a permeability change of 3% or less when immersed in a 2N hydrochloric acid solution for 30 minutes, and a thickness change of 3% or less when immersed in a 2N sodium hydroxide solution for 30 minutes, %. ≪ / RTI > More specifically, the magnetic sheet has a thickness change of 1% or less and a permeability change of 1% or less when immersed in a 2N hydrochloric acid solution for 30 minutes and has a thickness change of 1% or less when immersed in 2N sodium hydroxide solution for 30 minutes and It may have a permeability change of 1% or less.

In addition, the magnetic sheet may have corrosion resistance that can withstand various corrosive environments. For example, a magnetic sheet may have a rating number of 9.8 or higher in a salt spray test according to KS D 9502. The rating number method is an evaluation method of the degree of corrosion by the ratio of the corrosion area and the effective area, and is divided into a value of 0 to 10.

Further, the magnetic sheet may have a mass change of about 10% or less, or about 5% or less when immersed in a 2N NaCl solution for 10 minutes. In addition, the magnetic sheet may have a permeability change of about 10% or less, or about 5% or less when immersed in a 2N NaCl solution for 10 minutes.

When the magnetic sheet is treated for 72 hours under conditions of high temperature and high humidity of 85 캜 and 85% RH, the thickness and permeability change of the magnetic sheet may all be 10% or less, specifically 5% or less, more specifically 2% or less .

In addition, the magnetic sheet may have a high breakdown voltage. For example, the magnetic sheet may have a breakdown voltage of 3 kV or more, 3.5 kV or more, or 4 kV or more. More specifically, the magnetic sheet may have a breakdown voltage in the range of 3 to 6 kV, in the range of 3.5 to 5.5 kV, in the range of 4 to 5 kV, or in the range of 4 to 4.5 kV.

The magnetic sheet may exhibit a resistance value of 1 x 10 ⁵ Ω or more, 1 x 10 ⁷ Ω or more, or 1 x 10 ⁹ Ω or more when current is passed between two points separated by 500 μm or more on the sheet. Preferably, the magnetic sheet may exhibit resistance values which are impossible to measure or infinite resistance values when flowing current between two points separated by 500 mu m or more from each other on the sheet.

In the conductive magnetic composite sheet, the conductive foil can be laminated with a high bonding force by being directly bonded together with the curing of the binder resin constituting the magnetic sheet. Specifically, even if the conductive magnetic composite sheet is subjected to a high-temperature heat treatment process such as a reflow or soldering process for application to a product, the bonding force between the magnetic sheet and the conductive foil may not be lowered.

Preferably, the peel strength between the conductive foil and the magnetic sheet may be 0.6 kgf / cm or more, for example, in the range of 0.6 to 20 kgf / cm, in the range of 0.6 to 10 kgf / cm, in the range of 0.6 to 5 kgf / cm, or in the range of 0.6 to 3 kgf / cm.

Further, after the temperature of the conductive magnetic composite sheet was raised from 30 ° C to 240 ° C at a constant speed for 200 seconds, the heat treatment was repeated twice for a period of 100 seconds at a constant rate from 240 ° C to 130 ° C Thereafter, the conductive magnetic composite sheet may have a peel strength between the magnetic sheet and the conductive foil of 0.6 kgf / cm or more, for example, in the range of 0.6 to 20 kgf / cm, in the range of 0.6 to 10 kgf / cm, 5 kgf / cm, or in the range of 0.6 to 3 kgf / cm.

Further, when the heat treatment is repeated twice under the above conditions, the rate of change (lowering rate) of the peel strength between the conductive foil and the magnetic sheet may be 20% or less, 15% or less, or 10% or less.

Accordingly, even when the conductive magnetic composite sheet according to the embodiment has undergone a soldering process such as a reflow process, there is almost no change in physical properties such as permeability and thickness, and peeling or the like between the magnetic sheet and the conductive foil It does not cause defects.

Further, the conductive magnetic composite sheet is heated at a constant rate for 200 seconds from 30 to 240 ° C, and then heat-treated at a constant rate from 240 ° C to 130 ° C for 100 seconds, When the sheet is repeated twice, it may have a thickness variation of about 5% or less and a permeability variation of about 5% or less. Specifically, when the heat treatment conditions are repeated twice, the conductive magnetic composite sheet may have a thickness variation of about 3% or less and a permeability variation of about 3% or less, more specifically, a thickness variation of about 1% And may have a permeability change of about 1% or less.

When the conductive magnetic composite sheet is treated for 72 hours under high temperature and high humidity conditions of 85 캜 and 85% RH, the thickness and the permeability change of the conductive magnetic composite sheet are all 10% or less, specifically 5% % ≪ / RTI >

As described above, according to the embodiment, a conductive magnetic composite sheet having excellent magnetic properties at the frequencies of NFC, WPC and MST and excellent interlayer bonding force between the magnetic sheet and the conductive foil can be produced. In particular, the conductive magnetic composite sheet produced according to the embodiment may not suffer delamination even under various environmental changes such as heat treatment at a high temperature in order to apply it to a product.

Particularly, according to the embodiment, since the magnetic slurry is applied directly on the conductive foil, a carrier film for manufacturing the green sheet is not required, and the step of laminating the magnetic sheet and the conductive foil can be reduced. Further, according to the embodiment, the binder resin in the green sheet formed on the conductive foil is cured by heat and pressure to be pressed with the conductive foil while forming the magnetic sheet, so that the bonding force between the magnetic sheet and the conductive foil can be further improved .

Accordingly, the conductive magnetic composite sheet manufactured according to the embodiment can be usefully used for manufacturing antenna elements having NFC, WPC, and MST functions.

A method of manufacturing an antenna element according to an embodiment includes the steps of: preparing a magnetic slurry including magnetic powder, a thermosetting binder resin, and a solvent; Coating the magnetic slurry on the first conductive foil and drying to obtain a composite green sheet; Obtaining a conductive magnetic composite sheet by applying heat and pressure to the composite green sheet to cure the binder resin to form a magnetic sheet bonded to the first conductive foil; And etching the first conductive foil of the conductive magnetic composite sheet to form a first antenna pattern.

A method of manufacturing an antenna element according to another embodiment includes the steps of: preparing a magnetic slurry including a magnetic powder, a thermosetting binder resin, and a solvent; Coating the magnetic slurry on the first conductive foil and drying to obtain a composite green sheet; A second conductive foil is disposed on the composite green sheet, and heat and pressure are applied to cure the binder resin to form a magnetic sheet bonded with the first conductive foil and the second conductive foil to obtain a conductive magnetic composite sheet step; And etching the first conductive foil and the second conductive foil of the conductive magnetic composite sheet to form a first antenna pattern and a second antenna pattern, respectively.

The method of manufacturing the antenna element may further include the step of forming a via through the first conductive foil, the magnetic sheet, and the second conductive foil between the step of applying heat and pressure and the step of etching And the vias may be connected to the first antenna pattern and the second antenna pattern formed after the etching step.

Hereinafter, each step of the method for manufacturing the antenna element will be described in detail.

In the method of manufacturing the antenna element, a magnetic slurry is manufactured. Coating the magnetic slurry on a conductive foil and drying to obtain a composite green sheet; And the step of forming the magnetic sheet bonded to the conductive foil by applying heat and pressure can be carried out by substantially the same process conditions and methods as those exemplified in the production method of the conductive magnetic composite sheet. The conductive magnetic composite sheet thus produced may also have substantially the same configuration and characteristics as the conductive magnetic composite sheet according to the embodiment described above.

For example, the conductive magnetic composite sheet manufactured through the above steps is heated to a temperature of 30 ° C to 240 ° C at a constant rate for 200 seconds, then cooled down to a temperature of 240 ° C to 130 ° C at a constant rate for 100 seconds , A peel strength of 0.6 to 20 kgf / cm may be provided between the magnetic sheet and the first conductive foil when the heat treatment is repeated twice.

The magnetic sheet in the conductive magnetic composite sheet was heated to a temperature of 30 to 240 ° C at a constant rate for 200 seconds and then heat-treated at a constant rate of 240 to 130 ° C for 100 seconds. And a permeability change of 5% or less and a permeability change of 5% or less and a permeability change of 5% or less and a permeability change of 5% or less when immersed in a 2N hydrochloric acid solution for 30 minutes, and 2N sodium hydroxide solution Having a permeability change of 5% or less and a permeability change of 5% or less when immersed for 30 minutes, and having a permeability of 190 to 250 for an alternating current of 3 MHz and a ratio of 180 to 230 for an alternating current of 6.78 MHz With a magnetic permeability, it can have a permeability of 140 to 180 for an alternating current at a frequency of 13.56 MHz.

In the etching step, a mask pattern is formed on the conductive foil using a photoresist, and the conductive foil is patterned through the mask pattern. The etching may be performed using a conventional etching solution such as an aqueous acid solution. At this time, the magnetic sheet may have little change in thickness or permeability due to the etching solution due to its excellent chemical resistance.

The method of manufacturing the antenna element may further include forming a via between the magnetic sheet and the conductive foil between the step of applying heat and pressure and the step of etching.

12A to 12C show an example of a method of manufacturing an antenna element having a via.

First, as shown in Fig. 12A, a plurality of via-holes 260 are formed in the conductive magnetic composite sheet. The via holes 260 penetrate the magnetic sheet 100, the first conductive foil 210, and the second conductive foil 220. The via-hole may have a diameter in the range of, for example, 100 to 300 占 퐉, or 120 to 170 占 퐉.

Thereafter, as shown in FIG. 12B, the vias 250 can be formed by forming a plating layer on the inner surfaces of the via-holes 260. When the vias are formed by the plating process, vias formed in a large area can be formed at a time. That is, when the vias are formed of a plating layer, they can be easily and efficiently formed. Alternatively, conductive powder may be filled in the via-holes and then sintered to form vias. Alternatively, the vias may be formed by inserting solder or a conductive bar into the via-holes.

Thereafter, a mask pattern is formed by a process such as photoresist covering the first and second conductive foils 210 and 220, and as shown in FIG. 12C, the first conductive foil 210 and the second conductive foil 210, The second conductive foil 220 is selectively etched to form a first antenna pattern 231 and a second antenna pattern 232, respectively.

Since the magnetic sheet and the conductive foil are firmly bonded in the previous step, the antenna pattern formed through the etching process can be bonded to the magnetic sheet with an improved bonding force. Accordingly, the antenna element can have excellent bonding strength between the magnetic sheet and the antenna pattern even under high temperature conditions.

In addition, the antenna element according to the embodiment has excellent magnetic properties and can be used for a combination of NFC, WPC, and MST. Also, the antenna element according to the embodiment can improve the flexibility by using the polymer-type magnetic sheet and can be manufactured by the roll-to-roll process, thereby improving the processability.

The antenna element thus manufactured includes a magnetic sheet and an antenna pattern disposed on at least one surface of the magnetic sheet.

An antenna element according to an embodiment includes: a magnetic sheet including a magnetic powder and a thermosetting binder resin; And a first antenna pattern directly bonded to one surface of the magnetic sheet.

An antenna element according to another embodiment includes a magnetic sheet including a magnetic powder and a thermosetting binder resin; A first antenna pattern directly bonded to one surface of the magnetic sheet; And a second antenna pattern directly bonded to the other surface of the magnetic sheet.

In addition, the antenna element may further include a via through the magnetic sheet.

Hereinafter, the antenna element according to the embodiment will be described in detail by the constituent elements.

The magnetic sheet included in the antenna element may have substantially the same configuration and composition as the magnetic sheet in the conductive magnetic composite sheet manufactured according to the above embodiment.

For example, the magnetic sheet has a magnetic permeability of about 190-250 for an alternating current of 3 MHz frequency, a permeability of about 180-230 for an alternating current of 6.78 MHz, and an alternating current of 13.56 MHz A magnetic permeability of about 140 to 180 can be obtained.

Also, the magnetic sheet was heated at a constant rate for 200 seconds from 30 ° C to 240 ° C, and then heat-treated twice at 240 ° C to 130 ° C at a constant rate for 100 seconds. Or less and a permeability change of 5% or less, and may have a peel strength of 0.6 kgf / cm or more between the magnetic sheet and the antenna pattern.

The magnetic sheet may be a non-cured sheet having a thickness of 10 to 3000 탆 which has flexibility.

The antenna pattern is disposed on one or both surfaces of the magnetic sheet. At this time, the antenna pattern is directly bonded to the magnetic sheet. Accordingly, the antenna pattern can directly contact one surface or both surfaces of the magnetic sheet.

The antenna pattern may include a conductive material. For example, the antenna pattern may comprise a conductive metal. Specifically, the antenna pattern may include at least one metal selected from the group consisting of copper, nickel, gold, silver, zinc, and tin.

The pattern pattern of the antenna pattern according to the embodiment is not particularly limited. For example, a pattern can be formed to have a variety of functions including an NFC antenna, a WPC antenna, and an MST antenna. . In addition, the antenna pattern may be a printed circuit pattern. The antenna pattern may have a coil shape or a spiral shape.

The antenna element may further include a via through the magnetic sheet.

The vias contact and electrically connect to the antenna patterns disposed on both sides of the magnetic sheet. The vias may comprise a conductive material. For example, the vias may include one or more metals selected from the group consisting of copper, nickel, gold, silver, zinc, and tin.

Further, the magnetic sheet may include via holes penetrating up and down. The via-hole may have a diameter in the range of, for example, 100 to 300 占 퐉, or 120 to 170 占 퐉.

At this time, the via hole may be plated on the inner wall, filled with a conductive material, or may be formed by inserting a solder, a conductive bar, or the like. As an example, the magnetic sheet includes a via hole penetrating vertically, wherein the inner wall of the via hole is plated to form the via.

The antenna element according to the embodiment may have various configurations through the shape of the antenna pattern, the connection of vias and terminals, or the addition of wires.

According to a preferred embodiment, the antenna pattern includes a first antenna pattern disposed on one side of the magnetic sheet, and the antenna element further includes a wiring pattern disposed on the other side of the magnetic sheet, The via may include a first via penetrating through the magnetic sheet and connected to one end of the first antenna pattern and one end of the wiring pattern.

According to another preferred embodiment, the antenna pattern includes a plurality of first conductive line patterns spaced apart from each other on one surface of the magnetic sheet; And a plurality of second conductive line patterns spaced apart from each other on the other surface of the magnetic sheet, wherein the extending direction of the first conductive line patterns and the second conductive line patterns is the same, May be composed of a plurality of vias passing through the magnetic sheet and connecting the first conductive line patterns and the second conductive line patterns.

Hereinafter, specific embodiments of the antenna element will be exemplarily described.

According to one embodiment, referring to Figure 7, the antenna element comprises a magnetic sheet 100; A first antenna pattern (231) disposed on one side of the magnetic sheet; A wiring pattern (240) disposed on the other surface of the magnetic sheet; And a first via 251 passing through the magnetic sheet 100. The first via 251 is electrically connected to one end of the first antenna pattern 231 and one end of the wiring pattern 240, Lt; / RTI >

The antenna element according to the embodiment may further include a first terminal pattern and a second terminal pattern on one surface or the other surface of the magnetic sheet 100, 2 vias 252, and it is possible to design various antenna elements according to their arrangement positions and connection configurations.

FIGS. 8 to 10 show plan views of antenna elements according to various exemplary embodiments (the black pattern is a front pattern, the hatched pattern is a back pattern, and the circles are vias).

Hereinafter, more specific examples of the antenna element of the specific embodiment will be described with reference to the drawings.

8, the antenna element according to the embodiment includes a first terminal pattern 271 disposed on one side of the magnetic sheet 100; And a second via 252 penetrating the magnetic sheet 100. The second via 252 is formed on the other end of the first terminal pattern 271 and the wiring pattern 240, Can be connected. At this time, the antenna element further includes a second terminal pattern 272 disposed on one side of the magnetic sheet 100, and the other end of the first antenna pattern 231 is connected to the second terminal pattern 272, respectively. At this time, the first terminal pattern 271 and the second terminal pattern 272 may be disposed adjacent to each other.

9, the antenna element according to the embodiment further includes a first terminal pattern 271 disposed on the other surface of the magnetic sheet 100, and the first terminal pattern 271 May be connected to the other end of the wiring pattern 240. At this time, the antenna element includes a second terminal pattern 272 disposed on the other surface of the magnetic sheet 100; And a second via 252 penetrating through the magnetic sheet 100. The second via 252 is electrically connected to the second terminal pattern 272 and the other end of the first antenna pattern 231, Lt; / RTI > At this time, the first terminal pattern 271 and the second terminal pattern 272 may be disposed adjacent to each other.

10, the antenna element according to the embodiment further includes a first terminal pattern 271 disposed on the other surface of the magnetic sheet 100, and the first terminal pattern 271 May be connected to the other end of the wiring pattern 240. The antenna element may further include a second terminal pattern 272 disposed on one side of the magnetic sheet 100 and the second terminal pattern 272 may be disposed on the first side of the magnetic sheet 100. In this case, And may be connected to the other end of the antenna pattern 231.

The first antenna pattern and the wiring pattern are made of a conductive material, and the first antenna pattern is directly bonded to one surface of the magnetic sheet, Can be directly bonded to the other surface.

In the antenna element according to the embodiment, Referring to FIG. 13, the electromagnetic signal 50 can be generated due to the current flowing through the first antenna pattern. The electromagnetic signal 50 enables signal transmission / reception between the antenna element 20 and the external terminal 40.

In the antenna element according to the embodiment, the first antenna pattern and the wiring pattern are disposed on different surfaces of the magnetic sheet, and these patterns are connected to each other through the vias passing through the magnetic sheet. Thus, Since the same additional process is not required, the efficiency of the process can be increased. In addition, the antenna element according to the embodiment can prevent the thickness increase due to the covering of the wiring for insulation and the like, so that the thin film characteristics of the antenna element can be further improved.

According to another embodiment, the antenna element comprises a magnetic sheet; A plurality of first conductive line patterns spaced apart from each other on one surface of the magnetic sheet; A plurality of second conductive line patterns spaced apart from each other on a second surface of the magnetic sheet; And a plurality of vias disposed through the magnetic sheet, wherein the extending directions of the first conductive line patterns and the second conductive line patterns are the same, 2 conductive line patterns.

Specifically, the vias alternately connect the first conductive line patterns and the second conductive line patterns spaced apart from each other, so that one end and the other end of the first conductive line patterns are adjacent to each other And one end of the second conductive line patterns and the other end of the second conductive line patterns may be respectively connected to two first conductive line patterns adjacent to each other.

In addition, when the magnetic sheet is divided into a core region and a peripheral region around the core region, the first conductive line patterns and the second conductive line patterns extend across the core region, and both ends are disposed in the peripheral region The vias may be disposed in the peripheral region to connect the ends of the first conductive line patterns and the second conductive line patterns.

At this time, the first conductive line patterns, the second conductive line patterns, and the vias may be connected to each other to form a coil that winds the core region.

11A and 11B, the antenna element according to another embodiment of the present invention includes a magnetic sheet 100, a plurality of first conductive line patterns 233, a plurality of second conductive line patterns 234, (Not shown).

The magnetic sheet may be divided into a core region CR and a peripheral region OR adjacent to the core region.

The core region is disposed at a central portion of the magnetic sheet. The core region may have a shape extending in one direction.

The peripheral region is disposed around the core region. The peripheral region may have a shape extending in the same direction as the core region. The peripheral region may be disposed on both sides of the core region.

The first conductive line patterns are disposed on the magnetic sheet. More specifically, the first conductive line patterns are bonded to one surface of the magnetic sheet.

The first conductive line patterns may extend in a direction intersecting a direction in which the core region extends. More specifically, the first conductive line patterns may extend across the core region. The first conductive line patterns may extend from a peripheral region disposed on one side of the core region to a peripheral region disposed on the other side.

The first conductive line patterns may extend in parallel with each other. In addition, the first conductive line patterns may be spaced apart from each other.

And the second conductive line patterns are disposed on the other side of the magnetic sheet. More specifically, the second conductive line patterns are bonded to the other surface of the magnetic sheet.

The second conductive line patterns may extend in a direction intersecting the direction in which the core region extends. More specifically, the second conductive line patterns may extend across the core region. The second conductive line patterns may extend from a peripheral region disposed on one side of the core region to a peripheral region disposed on the other side.

The second conductive line patterns may extend in parallel with each other. In addition, the second conductive line patterns may be spaced apart from each other.

The vias penetrate the magnetic sheet. The vias connect the first conductive line patterns and the second conductive line patterns. More specifically, the vias may be connected to one end of the first conductive line pattern and one end of the second conductive line pattern.

The vias may alternately connect the first conductive line patterns and the second conductive line patterns. For example, a first conductive line pattern, a via, a second conductive line pattern, a via, a first conductive line pattern, a via, a second conductive line pattern, and a via may be sequentially connected.

The first conductive line pattern, the second conductive line pattern, and the vias may be connected to each other to form a coil wound around the core region. Specifically, the first conductive line pattern, the second conductive line pattern, and the via may be connected to each other to form a coil spirally wound around the core region.

Accordingly, when alternating current flows through the first conductive line pattern, the second conductive line pattern, and the via, electromagnetic signals can be formed through both ends of the core region.

As a preferred example, the magnetic sheet is formed thin, and the electromagnetic signal can be formed through the end of the core region at a high magnetic flux density. Accordingly, the antenna element according to the embodiment can have an improved reception sensitivity, and can easily transmit and receive electromagnetic signals even in a narrow gap.

The antenna element may be applied to a portable terminal.

A portable terminal according to an exemplary embodiment is a portable terminal including a case and an antenna element disposed in the case, the case including: an electromagnetic wave transmitting region; And an electromagnetic wave impermeable region, wherein the antenna element comprises: a magnetic sheet; A plurality of first conductive line patterns spaced apart from each other on one surface of the magnetic sheet; A plurality of second conductive line patterns spaced apart from each other on a second surface of the magnetic sheet; And a plurality of vias disposed through the magnetic sheet, wherein the extending directions of the first conductive line patterns and the second conductive line patterns are the same, And the electromagnetic wave transmission region may be disposed alongside the first conductive line patterns and the second conductive line patterns.

FIG. 14 shows a part of a portable terminal according to an embodiment. Referring to Fig. 14, the antenna element 20 is disposed in the case 30. The case 30 includes an electromagnetic wave transmitting region 32 and an electromagnetic wave non-transmitting region 31. The electromagnetic wave non-transmissive region may include a material that is shielded from electromagnetic waves such as metal. The electromagnetic wave transmitting region may include a material through which electromagnetic waves such as glass or plastic can be easily transmitted. The antenna element according to the embodiment can effectively exchange the electromagnetic signal 50 with the external terminal 40 even if the transmission region is narrowly formed.

On the other hand, a conventional antenna element is manufactured by forming an antenna pattern on an insulating base layer such as polyimide and padding a magnetic sheet so that even if a conductive line pattern is formed on both sides of the base layer and alternately connected via vias, The electromagnetic signal is clogged by the magnetic sheet attached on one side. On the other hand, the antenna element according to the embodiment forms a conductive line pattern formed on both sides by using a magnetic sheet as a base layer and forms a coil by alternately connecting through a via, so that the flow of electromagnetic signals is not blocked, Characteristics can have improved communication sensitivity.

Hereinafter, more specific embodiments will be described by way of example.

The materials used in the following examples are as follows:

- Sandst powder: C1F-02A, Crystallite Technology

- Polyurethane resin: UD1357, Daiichi Seika Kogyo Co., Ltd.

- Isocyanate-based curing agent: isophorone diisocyanate, Sigma-Aldrich

- Epoxy resin: bisphenol A epoxy resin (epoxy equivalent = 189 g / eq), Epikote ^TM 828, Japan Epoxy Resin

Example 1: Production of copper-clad laminated magnetic composite sheet

Step (1) Production of magnetic slurry

42.8 parts by weight of sandstorm powder as a magnetic powder, 15.4 parts by weight of a polyurethane-based resin dispersion (25% by weight of a polyurethane resin and 75% by weight of 2-butanone) and 1.0 part by weight of an isocyanate curing agent dispersion (62% by weight of an isocyanate- (Epoxy resin 70 wt%, n-butyl acetate 3 wt%, 2-butanone 15 wt%, toluene 13 wt%), 0.4 wt% ), And 40.5 parts by weight of toluene were mixed in a planetary mixer at a speed of about 40-50 rpm for about 2 hours to prepare a magnetic slurry.

Step (2) Production of composite green sheet

The previously prepared magnetic slurry was coated on a copper foil having a thickness of about 37 mu m by a comma coater and dried at a temperature of about 110 DEG C to prepare a composite green sheet.

Step (3) Bonding by heat pressing

A copper foil having a thickness of about 37 占 퐉 was further placed on the composite green sheet and compression-cured by a hot press process at a temperature of about 170 占 폚 and a pressure of about 9 MPa for about 60 minutes, To obtain a copper-clad laminated magnetic composite sheet to which a copper foil was bonded.

Example 2: Fabrication of antenna element

A number of via holes having a diameter of about 0.15 mm were formed on the copper-clad laminated magnetic composite sheet obtained in Example 1 using a drill. Thereafter, copper was plated in the via-holes to prepare vias connecting copper foils on the upper and lower surfaces. Thereafter, a mask pattern was formed on the upper and lower surfaces of the above-described copper-clad laminated magnetic composite sheet, and a part of the copper foil was etched through an etching process. Thus, an antenna element having upper patterns and lower patterns was obtained.

Test Example

The copper-clad laminated magnetic composite sheet produced in Example 1 and the antenna element produced in Example 2 were tested according to the following procedure.

For the evaluation of only the magnetic sheet, the magnetic slurry prepared in the step (1) of Example 1 was dried and cured under the same process conditions as in Example 1 to prepare a magnetic sheet, followed by the following procedure Respectively.

(1) Measurement of permeability

Through the impedance analyzer, the permeability and investment loss of the magnetic sheet were measured. The results are summarized in Table 1 below.

Frequency 3 MHz Frequency 6.78 MHz Frequency 13.56 MHz Investment ratio Investment loss Investment ratio Investment loss Investment ratio Investment loss 215 17.5 200 50.1 160 63

As shown in Table 1, the magnetic sheet had excellent permeability in all three bands.

(2) Heat resistance measurement - Reflow test

The magnetic sheet, the copper-clad laminated magnetic composite sheet and the antenna element were placed in an oven, the temperature was raised from 30 ° C to 240 ° C at a constant speed for 200 seconds, the temperature was lowered at a constant rate from 240 ° C to 130 ° C for 100 seconds The reflow test was performed twice under the heat treatment condition (see FIG. 15). Thereafter, the thickness variation, the magnetic permeability variation and the bonding force variation of the magnetic sheet, the copper-clad laminated magnetic composite sheet and the antenna element were measured.

As a result, both the thickness and the magnetic permeability change of the magnetic sheet, the copper-clad laminated magnetic composite sheet and the antenna element were measured to be less than 5% after the second reflow test.

Further, the peel strength of the magnetic sheet with the copper foil in the copper-clad laminated magnetic composite sheet after the second reflow test was measured to be 0.6 kgf / cm or more.

(3) Heat resistance measurement - Pb floating test

The magnetic sheet, the copper-clad laminated magnetic composite sheet and the antenna element were placed in a fused bath and allowed to stand for 40 seconds and then observed. As a result, no blister was observed in both the magnetic sheet, the copper-clad laminated magnetic composite sheet and the antenna element.

(4) Chemical resistance measurement

After immersing the magnetic sheet in the aqueous 2N HCl solution for about 30 minutes, the mass change, the thickness change and the magnetic permeability change of the magnetic sheet were measured. Further, after the magnetic sheet was immersed in the aqueous 2N NaOH solution for about 30 minutes, the mass change, the thickness change and the magnetic permeability change of the magnetic sheet were measured. As a result, no precipitation of magnetic powder occurred in the lower part of the solution, and the mass change, the mass change of the magnetic sheet, the thickness change and the permeability change were both measured to be less than 5%.

(5) Measurement of rust prevention characteristics

KS D9502, a magnetic sheet was sprayed with NaCl neutral brine at a concentration of 5% at an average of 1 to 2 mL per hour for 72 hours at 35 ° C, and then rust formation was observed. The ration number was measured by the area method (rating number method) to be 9.8 or more. (Rating number method is an evaluation method indicating the degree of corrosion by the ratio of corrosion area to effective area. .

(6) Peel strength measurement

Using a universal testing machine (UTM), the peel strength between the magnetic sheet and the copper foil of the copper-clad laminated magnetic composite sheet was measured. As a result, the peel strength was measured to be 0.6 kgf / cm or more.

(7) Measurement of joint strength - Crosscut test

The bonding force between the magnetic sheet and the copper foil of the copper-clad laminated magnetic composite sheet was measured by the cross-cut test (ASTM D3369). Cross cut test results were measured as 0/100 to 5/100.

(8) Measurement of high temperature and high humidity characteristics

The magnetic sheet, the copper-clad laminated magnetic composite sheet, and the antenna element were allowed to stand in a constant temperature and humidity oven at 85 ° C / 85% RH for 72 hours, and then the change in thickness and the permeability were measured. As a result, both the thickness change of the magnetic sheet, the copper-clad laminated magnetic composite sheet and the antenna element and the change in the magnetic permeability were all measured to be 5% or less.

10: laminate, 20: antenna element according to the embodiment,
30: Case,
31: Electromagnetic wave non-transmission area, 32: Electromagnetic wave transmission area,
40: external terminal, 50: electromagnetic signal,
100: magnetic sheet, 101: green sheet,
102: magnetic slurry, 110: magnetic powder,
120: (hardened) binder resin, 121: (uncured) binder resin,
210: first conductive foil, 220: second conductive foil,
231: first antenna pattern, 232: second antenna pattern,
233: first conductive line pattern, 234: second conductive line pattern,
240: wiring pattern, 250: via,
251: first via, 252: second via,
260: via hole,
271: first terminal pattern, 272: second terminal pattern,
400: carrier film, 500: coater,
600: roll, 700: heat and pressure,
CR: core region, OR: peripheral region.

Claims (15)

Preparing a magnetic slurry comprising a magnetic powder, a thermosetting binder resin and a solvent;
Coating the magnetic slurry on the first conductive foil and drying to obtain a composite green sheet; And
Applying a heat and a pressure to the composite green sheet to cure the binder resin to form a magnetic sheet bonded to the first conductive foil to thereby obtain a conductive magnetic composite sheet,
When the conductive magnetic composite sheet is heated twice from 230 ° C. to 130 ° C. at a constant rate for 100 seconds after raising the temperature from 30 ° C. to 240 ° C. at a constant rate for 200 seconds, And a peel strength of 0.6 to 20 kgf / cm between the magnetic sheet and the first conductive foil.
The method according to claim 1,
Wherein the magnetic slurry contains at least one organic solvent selected from the group consisting of aromatic hydrocarbons, aliphatic ketones and aliphatic esters in an amount of 20 to 90% by weight based on the total weight of the magnetic slurry, ≪ / RTI >
3. The method of claim 2,
Based on the weight of the solid content excluding the solvent,
The magnetic powder is contained in an amount of 70 to 90% by weight,
As the binder resin, 6 to 12% by weight of a polyurethane resin; 0.5 to 2% by weight of an isocyanate-based curing agent; And 0.3 to 1.5% by weight of an epoxy resin.
The method according to claim 1,
The coating of the magnetic slurry is carried out at a speed of 0.5 to 5 m / min using a lip coater, a doctor blade or a comma coater,
Wherein the drying of the magnetic slurry is performed at a temperature of 20 to 150 DEG C to remove the solvent in the magnetic slurry.
The method according to claim 1,
Wherein the step of applying heat and pressure is performed at a pressure of 5 to 30 MPa and at a temperature of 150 to 200 DEG C so that the magnetic sheet is brought into direct contact with the first conductive foil to bond the conductive magnetic composite sheet Way.
delete The method according to claim 1,
The magnetic sheet was heated at a constant rate for 200 seconds from 30 ° C to 240 ° C and then heat-treated twice at 240 ° C to 130 ° C at a constant rate for 100 seconds. And a permeability change of 5% or less.
8. The method of claim 7,
The magnetic sheet
Having a permeability of 190 to 250 for an alternating current of 3 MHz frequency,
Having a permeability of 180 to 230 for alternating current at a frequency of 6.78 MHz,
Having a permeability of 140 to 180 for an alternating current at a frequency of 13.56 MHz,
A method for producing a conductive magnetic composite sheet.
Preparing a magnetic slurry comprising a magnetic powder, a thermosetting binder resin and a solvent;
Coating the magnetic slurry on the first conductive foil and drying to obtain a composite green sheet; And
A second conductive foil is disposed on the composite green sheet, and heat and pressure are applied to cure the binder resin to form a magnetic sheet bonded with the first conductive foil and the second conductive foil to obtain a conductive magnetic composite sheet ≪ / RTI >
When the conductive magnetic composite sheet is heated twice from 230 ° C. to 130 ° C. at a constant rate for 100 seconds after raising the temperature from 30 ° C. to 240 ° C. at a constant rate for 200 seconds, And a peel strength of 0.6 to 20 kgf / cm between the magnetic sheet and the first conductive foil.
10. The method of claim 9,
The coating of the magnetic slurry is performed at a speed of 0.5 to 5 m / min using a lip coater, a doctor blade or a comma coater;
Drying of the magnetic slurry is performed at a temperature of from 20 to 150 DEG C to remove the solvent in the magnetic slurry;
The step of applying heat and pressure is performed at a pressure of 5 to 30 MPa and a temperature condition of 150 to 200 DEG C;
Wherein the magnetic sheet is in direct contact with and bonded to the first conductive foil and the second conductive foil.
Preparing a magnetic slurry comprising a magnetic powder, a thermosetting binder resin and a solvent;
Coating the magnetic slurry on the first conductive foil and drying to obtain a composite green sheet;
Obtaining a conductive magnetic composite sheet by applying heat and pressure to the composite green sheet to cure the binder resin to form a magnetic sheet bonded to the first conductive foil; And
And etching the first conductive foil of the conductive magnetic composite sheet to form a first antenna pattern,
When the conductive magnetic composite sheet is heated twice from 230 ° C. to 130 ° C. at a constant rate for 100 seconds after raising the temperature from 30 ° C. to 240 ° C. at a constant rate for 200 seconds, And a peel strength of 0.6 to 20 kgf / cm between the magnetic sheet and the first conductive foil.
delete 12. The method of claim 11,
The magnetic sheet
The temperature is raised from 30 ° C to 240 ° C at a constant rate for 200 seconds and then the temperature is lowered from 240 ° C to 130 ° C at a constant rate for 100 seconds. When the heat treatment is repeated twice, Having a permeability change of 5% or less,
It has a thickness change of 5% or less and a permeability change of 5% or less when immersed in a 2N hydrochloric acid solution for 30 minutes and has a thickness change of 5% or less and a permeability change of 5% or less when immersed in 2N sodium hydroxide solution for 30 minutes ,
Having a permeability of 190 to 250 for an alternating current of 3 MHz frequency,
Having a permeability of 180 to 230 for alternating current at a frequency of 6.78 MHz,
Having a permeability of 140 to 180 for an alternating current at a frequency of 13.56 MHz,
A method of manufacturing an antenna element.
Preparing a magnetic slurry comprising a magnetic powder, a thermosetting binder resin and a solvent;
Coating the magnetic slurry on the first conductive foil and drying to obtain a composite green sheet;
A second conductive foil is disposed on the composite green sheet, and heat and pressure are applied to cure the binder resin to form a magnetic sheet bonded with the first conductive foil and the second conductive foil to obtain a conductive magnetic composite sheet step; And
And forming a first antenna pattern and a second antenna pattern by etching the first conductive foil and the second conductive foil of the conductive magnetic composite sheet,
When the conductive magnetic composite sheet is heated twice from 230 ° C. to 130 ° C. at a constant rate for 100 seconds after raising the temperature from 30 ° C. to 240 ° C. at a constant rate for 200 seconds, And a peel strength of 0.6 to 20 kgf / cm between the magnetic sheet and the first conductive foil.
15. The method of claim 14,
The method of manufacturing the antenna element further comprises forming a via between the step of applying heat and pressure and the step of etching through the first conductive foil, the magnetic sheet, and the second conductive foil and,
Wherein the vias are connected to the first antenna pattern and the second antenna pattern formed after the etching step.

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