KR101831869B1 - Magnetic sheet and antenna device comprising same - Google Patents

Abstract

The magnetic sheet according to the embodiment has excellent magnetic properties at the frequencies of NFC, WPC and MST, and has improved heat resistance characteristics. Further, the magnetic sheet is not only excellent in flexibility but also can contain a magnetic powder in a high content and can have excellent magnetic properties. Accordingly, the conductive magnetic composite sheet and the antenna element manufactured using the magnetic sheet can be usefully used for NFC, WPC, and MST applications.

Description

Technical Field [0001] The present invention relates to a magnetic sheet and an antenna element including the same.

Embodiments relate to a magnetic sheet that can be used in fields such as short-range communication, wireless charging, and magnetic security transmission, and an antenna element including the same.

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. If the adhesive layer is provided to prevent such peeling, another problem arises that the entire thickness of the antenna element becomes thick.

There is an attempt to fabricate an antenna element by using a magnetic sheet as a base layer and laminating a conductive layer thereon and then forming an antenna pattern by etching. However, And a heat-resistant property capable of enduring a reflow or soldering process performed for application to a product, etc., are required for the magnetic sheet.

Accordingly, the magnetic sheet of the present invention has excellent magnetic properties, such as NFC, WPC and MST, which can be manufactured by a simple process with a thin thickness and excellent heat resistance and chemical resistance, To provide a conductive magnetic composite sheet and an antenna element.

According to one embodiment, the magnetic powder comprises a magnetic powder and a binder resin and has a magnetic permeability of 100 to 300 for an alternating current of 3 MHz frequency, a permeability of 80 to 270 for an alternating current of 6.78 MHz, a frequency of 13.56 MHz The temperature is raised from 30 ° C. to 240 ° C. at a constant rate for 200 seconds and then the temperature is lowered at a constant rate from 240 ° C. to 130 ° C. for 100 seconds. A magnetic sheet having a thickness variation of 10% or less and a magnetic permeability variation of 10% or less is provided.

According to another embodiment, there is provided a conductive magnetic composite sheet comprising a magnetic sheet and a conductive layer disposed on at least one side of the magnetic sheet, wherein the magnetic sheet has a permeability of 100 to 300 for an alternating current of 3 MHz frequency, The temperature was raised from 30 DEG C to 240 DEG C for 200 seconds at a constant rate with a magnetic permeability of 80 to 270 for an alternating current of 6.78 MHz and an alternating current of 60 to 250 for an alternating current of 13.56 MHz, The conductive magnetic composite sheet having a thickness change of 10% or less and a permeability change of 10% or less when the heat treatment is repeated twice under a condition of lowering the temperature at a constant rate for 100 seconds from 0 to 130 deg.

According to yet another embodiment, there is provided an antenna element comprising a magnetic sheet and an antenna pattern disposed on at least one side of the magnetic sheet, wherein the magnetic sheet has a magnetic permeability of 100 to 300 for an alternating current of 3 MHz frequency, MHz and a permeability of 60 to 250 for an alternating current of 13.56 MHz, the temperature was raised from 30 DEG C to 240 DEG C for 200 seconds at a constant rate, and then 240 DEG C To 130 < 0 > C for a period of 100 seconds at a constant rate, a thickness change of 10% or less and a permeability change of 10% or less when the heat treatment is repeated twice.

According to another embodiment, there is provided a method of manufacturing a magnetic sensor, comprising: (1) forming a conductive layer on at least one surface of a magnetic sheet; And (2) etching the conductive layer to form an antenna pattern, wherein the magnetic sheet has a magnetic permeability of 100 to 300 for an alternating current of 3 MHz frequency, Having a magnetic permeability of 80 to 270 for an alternating current and having a magnetic permeability of 60 to 250 for an alternating current of 13.56 MHz, raising the temperature from 30 to 240 DEG C for 200 seconds at a constant rate, A temperature change of not more than 10% and a permeability change of not more than 10% when the heat treatment is repeated twice under the condition of lowering the temperature at a constant rate for 100 seconds.

The magnetic sheet according to the embodiment has excellent magnetic properties at the frequencies of NFC, WPC, and MST, and has improved acid / base resistance and corrosion resistance. In particular, the magnetic sheet can harden the binder resin by heat and can more firmly hold the magnetic powder, so that the magnetic sheet can be hardened even when various environmental changes such as etching treatment for patterning or reflow or soldering for application to a product, There may be little change in thickness.

Accordingly, by using the magnetic sheet to directly form the conductive layer or the antenna pattern layer on the magnetic sheet without an insulating substrate such as polyimide, the thickness can be reduced and the manufacturing process can be simplified. Further, the magnetic sheet is not only excellent in flexibility but also can contain a magnetic powder in a high content and can have excellent magnetic properties.

Accordingly, the conductive magnetic composite sheet and the antenna element manufactured using the magnetic sheet can be usefully used for NFC, WPC, and MST applications.

1 shows a cross section of a magnetic sheet according to an embodiment.
2A and 2B are cross-sectional views of a conductive magnetic composite sheet according to an embodiment.
FIG. 3 shows a process of manufacturing a magnetic sheet according to an embodiment.
FIG. 4 shows a manufacturing process of the conductive magnetic composite sheet according to the embodiment.
5 and 6 show the roll-to-roll process and the batch process, respectively.
FIGS. 7 and 8 show a manufacturing process of the conductive magnetic composite sheet according to the embodiment.
9 shows a cross-sectional view of an antenna element according to an embodiment.
FIGS. 10A-10C show plan views of an antenna element according to an embodiment. (Of the patterns, the black pattern is the front pattern, the hatched pattern is the back pattern, and the circle designates the beacon).
11A and 11B are plan views showing a plan view and a cross-sectional view of the antenna element according to the embodiment.
12A to 12C show a process of manufacturing the antenna element according to the embodiment.
FIGS. 13 and 14 are diagrams schematically showing that the antenna element according to the embodiment transmits / receives signals to / from an external terminal.
Fig. 15 shows heat treatment conditions at the time of the reflow test.

In the 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, Quot; and "under " include both being formed" directly "or" indirectly "through" other elements ". 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.

The magnetic sheet according to the embodiment comprises a magnetic powder and a binder resin and has a magnetic permeability of 100 to 300 for an alternating current of 3 MHz frequency and a permeability of 80 to 270 for an alternating current of 6.78 MHz, The temperature is raised at a constant rate from 30 ° C to 240 ° C for 200 seconds and then the temperature is lowered at a constant rate from 240 ° C to 130 ° C for 100 seconds. , It has a thickness variation of 10% or less and a permeability variation of 10% or less.

1 shows a cross section of a magnetic sheet according to an embodiment.

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

That is, the magnetic sheet 100 is a polymeric magnetic sheet (PMS). Specifically, the magnetic sheet 100 may be an unfired cured sheet containing the magnetic powder 110 and the binder resin 120. [ The magnetic sheet 100 may be a flexible magnetic sheet.

The magnetic sheet (100) contains a magnetic powder (110).

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

In this formula,

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.

As the binder resin 120, a curable resin may be used. Specifically, the binder resin may include a photocurable resin, a thermosetting resin, and / or a high heat-resistant thermoplastic resin, and may preferably include a thermosetting resin.

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 2b]

In this formula,

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;

At this time, each of the C _{1 - 5} alkylene group does not have, or have a substituent selected from the group consisting of halogen, cyano, amino and nitro one or more of them.

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.

In addition, the magnetic sheet 100 may 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 sheet may contain the magnetic powder in an amount of 50 wt% or more, or 70 wt% or more. For example, the magnetic sheet may contain magnetic powder in an amount of 50 to 95 wt%, 70 to 95 wt%, 70 to 90 wt%, 75 to 90 wt%, 75 to 95 wt%, 80 to 95 wt% By weight to 90% by weight. In this case, the magnetic powder may have the composition of Formula 1.

The magnetic sheet 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.

The magnetic sheet may further contain, as the binder resin, 6 to 12% by weight of a polyurethane resin, 0.5 to 2% by weight of an isocyanate curing agent, and 0.3 to 1.5% by weight of an epoxy resin, based on the total weight of the magnetic sheet .

The magnetic sheet may contain the antirust agent in an amount of 1 to 10 wt%, 1 to 8 wt%, or 3 to 7 wt%.

According to a specific example, the magnetic sheet comprises a magnetic powder in an amount of 70 to 95% by weight based on the total weight of the magnetic sheet, 6 to 12% by weight of a polyurethane resin as a binder resin, 0.5 to 2% % Of an isocyanate-based curing agent, and 0.3 to 1.5 wt% of an epoxy-based resin. In this case, the magnetic powder preferably has the composition of Formula 1, and the polyurethane resin includes the repeating units represented by the above formulas (2a) and (2b), wherein the isocyanate curing agent is an alicyclic diisocyanate, A type epoxy resin, cresol novolak type epoxy resin, or tetrakis (glycidyloxyphenyl) ethane type epoxy resin.

The thickness of the magnetic sheet 100 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 has a magnetic permeability of about 100 to 300 for an alternating current of 3 MHz frequency, a permeability of about 80 to 270 for an alternating current of 6.78 MHz, a magnetic permeability of about 60 to 250 for an alternating current of 13.56 MHz Permeability.

Alternatively, the magnetic sheet may have a permeability of about 190 to 250 for an AC current of 3 MHz frequency, a permeability of about 180 to 230 for an AC current of 6.78 MHz, 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. Wherein the magnetic sheet has a temperature of from 30 to 240 캜 for 200 seconds at a constant rate, and then the temperature is lowered at a constant rate from 240 캜 to 130 캜 for 100 seconds. When the heat treatment is repeated twice, And a permeability change of 10% or less. Specifically, the magnetic sheet may have a thickness variation of 5% or less and a permeability variation of 5% or less when the heat treatment is repeated twice. More specifically, the magnetic sheet may have a thickness change of 3% or less and a permeability change of 3% or less when the heat treatment is repeated twice.

Also, 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.

In addition, the magnetic sheet may have chemical resistance that can withstand various environments. When the magnetic sheet is immersed in a solution of about 2N hydrochloric acid for 10 minutes, it may have a mass change of about 10% or less, or about 5% or less. Further, when the magnetic sheet is immersed in a 2N hydrochloric acid solution for 10 minutes, it may have a thickness variation of about 10% or less, or about 5% or less. 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 hydrochloric acid solution for 10 minutes.

Specifically, when the magnetic sheet is immersed in a 2N hydrochloric acid solution for 30 minutes, it has a thickness change of 5% or less and a permeability change of 5% or less. When the magnetic sheet is immersed in a 2N sodium hydroxide solution for 30 minutes, %. ≪ / RTI >

More specifically, the magnetic sheet has a thickness variation of 3% or less and a permeability change of 3% or less when immersed in a 2N hydrochloric acid solution for 30 minutes and has a thickness variation of 3% or less when immersed in 2N sodium hydroxide solution for 30 minutes and And may have a permeability change of 3% 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 that indicates the degree of corrosion by the ratio of corrosion area to effective area, and is divided into values 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 .

Further, the magnetic sheet may have a high tensile strength.

The magnetic sheet according to the embodiment can be produced by a method including mixing magnetic powder and binder resin, and forming and drying in a sheet form. At this time, the magnetic powder and the binder resin may be used in the kind and content as exemplified above.

Specifically, the magnetic sheet comprises: (i) dispersing a magnetic powder in a binder resin and a solvent to prepare a slurry; And (ii) shaping the sheet using the slurry and then drying the sheet.

According to one embodiment, the method for producing the magnetic sheet includes the steps of (1) mixing a polyurethane resin, an isocyanate curing agent, and an epoxy resin to prepare a binder resin; (2) mixing a magnetic powder and an organic solvent in the binder resin to prepare a slurry; And (3) shaping the slurry into a sheet and drying the magnetic sheet, wherein the magnetic sheet comprises, as the binder resin, from 6 wt% to 12 wt%, based on the total weight of the magnetic sheet, Polyurethane-based resin; 0.5% to 2% by weight of an isocyanate-based curing agent; And 0.3% by weight to 1.5% by weight of an epoxy resin.

As a specific example, a magnetic powder is first 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.) ≪ / RTI > Thereafter, the slurry is coated on a carrier film by a comma coater or the like to form a dry magnetic sheet. The dried magnetic sheet may be manufactured from a polymer magnetic sheet (PMS) by adjusting the speed and temperature according to the thickness to be formed, removing the solvent through a drier, and winding the molded sheet.

3, when the manufacturing process of the dried magnetic sheet 101 is performed by a roll-to-roll process, a slurry containing a magnetic powder and a binder resin is coated on the carrier film 400 by a coater 500 And then dried to prepare a dried magnetic sheet 101. [ At this time, the dried magnetic sheet 101 may include an unhardened or semi-hardened binder resin 121.

Thus, the dried magnetic sheet thus produced may be a magnetic sheet in which curing of the binder resin is not completed.

In addition, the magnetic sheet may be cured by heat pressing after the drying step. That is, in the method of manufacturing the magnetic sheet, after the step (3), the step of curing the binder resin in the magnetic sheet by heat-pressurizing the magnetic sheet at a pressure of 1 to 100 MPa and a temperature of 100 to 300 ° C May be further included. As a result, the obtained magnetic sheet may be a magnetic sheet on which the hardening of the binder resin has been completed.

The conductive magnetic composite sheet according to the embodiment includes a magnetic sheet and a conductive layer disposed on at least one surface of the magnetic sheet, wherein the magnetic sheet has a magnetic permeability of 100 to 300 for an alternating current of 3 MHz frequency, MHz and a permeability of 60 to 250 for an alternating current of 13.56 MHz, the temperature was raised from 30 DEG C to 240 DEG C for 200 seconds at a constant rate, and then 240 DEG C To 130 < 0 > C for 100 seconds under the condition of lowering the temperature at a constant rate. The heat treatment is repeated two times to have a thickness change of 10% or less and a permeability change of 10% or less.

2A and 2B are cross-sectional views of a conductive magnetic composite sheet according to an embodiment.

Referring to FIG. 2A, the conductive magnetic composite sheet according to the embodiment includes a magnetic sheet 100, a first conductive layer 210, and a second conductive layer 220. Referring to FIG. 2B, the conductive magnetic composite sheet according to the embodiment may further include a first adhesive layer 310 and a second adhesive layer 320. Thus, the conductive magnetic composite sheet is a composite sheet in which a conductive layer and a magnetic sheet are laminated. For example, the conductive magnetic composite sheet may be a copper-clad laminated magnetic composite sheet.

The magnetic sheet 100 included in the conductive magnetic composite sheet may have substantially the same structure and composition as the magnetic sheet according to the embodiment described above, and may be manufactured by substantially the same method.

The magnetic sheet has a magnetic permeability of about 100 to 300 for an alternating current of 3 MHz frequency, a permeability of about 80 to 270 for an alternating current of 6.78 MHz, a magnetic permeability of about 60 to 250 for an alternating current of 13.56 MHz Permeability.

According to a specific example, the magnetic sheet comprises a magnetic powder in an amount of 70 to 95% by weight based on the total weight of the magnetic sheet, 6 to 12% by weight of a polyurethane resin as a binder resin, 0.5 to 2% % Of an isocyanate-based curing agent, and 0.3 to 1.5 wt% of an epoxy-based resin. In this case, the magnetic powder preferably has the composition of Formula 1, and the polyurethane resin includes the repeating units represented by the above formulas (2a) and (2b), wherein the isocyanate curing agent is an alicyclic diisocyanate, A type epoxy resin, cresol novolak type epoxy resin, or tetrakis (glycidyloxyphenyl) ethane type epoxy resin.

The conductive layers 210 and 220 are disposed on at least one surface of the magnetic sheet 100. That is, the conductive layers 210 and 220 are disposed on one surface and / or the other surface of the magnetic sheet 100. As shown in FIG. 2A, the conductive layers 210 and 220 may be directly bonded to the magnetic sheet 100 without a separate adhesive layer. Accordingly, the conductive layers 210 and 220 can directly contact the surface of the magnetic sheet 100. At this time, the conductive layers 210 and 220 may be directly bonded to the binder resin 120 of the magnetic sheet 100. Specifically, the conductive layers 210 and 220 may be directly bonded to the thermosetting resin constituting the binder resin 120.

The conductive layers 210 and 220 may include a conductive material. For example, the conductive layer may comprise a conductive metal. That is, the conductive layer may be a metal layer. For example, the conductive layer may comprise at least one metal selected from the group consisting of copper, nickel, gold, silver, zinc and tin. Specifically, the conductive layer may be a metal foil. More specifically, the conductive layer may be a copper foil (copper foil).

The thickness of the conductive layer 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.

An adhesive layer 310 or 320 may be interposed between the magnetic sheet 100 and the conductive layers 210 and 220 as shown in FIG. That is, the conductive magnetic composite sheet may further include adhesive layers 310 and 320 interposed between the magnetic sheet 100 and the conductive layers 210 and 220, And the conductive layers 210 and 220, respectively.

Thus, the adhesive layer can adhere the conductive layer to the magnetic sheet. The thickness of the adhesive layer may be about 0.1 to 20 [mu] m. More specifically, the thickness of the adhesive layer may be about 0.1 to 10 microns, about 1 to 7 microns, or about 1 to 5 microns.

The adhesive layer may include a thermosetting resin or a high heat-resistant thermoplastic resin. Specifically, the adhesive layer may include an epoxy resin or the like.

The adhesive layer can adhere the magnetic sheet and the conductive layer by thermal curing. Therefore, the adhesive layer can have high heat resistance and high adhesive strength.

Further, the adhesive layer may have a high chemical resistance including a thermosetting resin. Accordingly, the adhesive layer can function to protect the magnetic sheet. That is, when the conductive layer is etched by the etching solution, the adhesive layer can protect the magnetic sheet from the etching solution.

As described above, the conductive layer can be bonded to the magnetic sheet directly or by bonding with an adhesive layer, thereby bonding with high bonding strength. Specifically, even if the conductive layer is bonded to the curing of the thermosetting resin constituting the magnetic sheet or the adhesive layer and subjected to a high-temperature heat treatment step, the bonding force between the magnetic sheet and the conductive layer may not be lowered.

Preferably, the peel strength between the conductive layer and the magnetic sheet may be 0.6 kgf / cm or more. 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 , And the conductive magnetic composite sheet may have a peel strength of 0.6 kgf / cm or more between the magnetic sheet and the conductive layer.

Further, when the heat treatment is repeated twice under the above conditions, the rate of change (lowering ratio) of the peel strength between the conductive layer 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 is subjected to 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 layer It does not cause defects.

The magnetic composite sheet according to the embodiment can be produced by preparing a magnetic sheet and then laminating the conductive layer on the magnetic sheet.

First, the magnetic powder and the binder resin are mixed by the above-described method, and the mixture is formed into a sheet and dried to prepare a dried magnetic sheet.

Thereafter, a conductive layer is disposed on one side or both sides of the dried magnetic sheet.

The conductive layer may be a conductive foil, specifically a metal foil, and more specifically a copper foil.

The dried magnetic sheet and the conductive layer are laminated by heat and pressure.

At this time, the pressure applied to the magnetic sheet and the conductive layer may be about 1 to 100 MPa. The temperature at which the magnetic sheet and the conductive layer are laminated may be about 100 to 300 ° C. The laminating process of the magnetic sheet and the conductive layer may be performed for about 0.1 to 5 hours.

During the lapping process, the binder resin contained in the magnetic sheet may be cured by heat.

Accordingly, as shown in FIG. 4, the magnetic sheet 100 in which the hardening of the binder resin is completed can be formed, and the conductive layers 210 and 220 can be bonded to the magnetic sheet 100. Since the conductive layers 210 and 220 are bonded to the magnetic sheet 100 by thermal curing, the bonding strength between the magnetic sheet and the conductive layer can be excellent. Particularly, since the magnetic sheet and the conductive layer are bonded while the binder resin is cured at the same time as the pressing, the bonding strength can be further improved. Accordingly, the magnetic sheet and the conductive layer can be easily bonded without using a separate adhesive layer.

Specifically, the lapping process may be performed by a roll-to-roll process or a batch process.

As shown in FIG. 5, the lapping process may proceed to a roll-to-roll process. In the roll-to-roll process, conductive layers 210 and 220 are laminated on one side or both sides of the dried magnetic sheet 101 in which curing of the binder resin is not completed, and the roll 600 is passed. At this time, the roll itself is heated, and the roll can simultaneously apply heat and pressure to the laminate. That is, the magnetic sheet and the conductive layer are continuously joined by the roll. As a result, the magnetic sheet 100 in which the binder resin is hardened can be formed, and the conductive layers 210 and 220 can be 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 lapping process may be about 1 to 20 pairs. The moving speed of the laminate may be about 0.1 to 10 m / min.

As shown in FIG. 6, the lapping process may proceed to a batch process. Specifically, the dried magnetic sheet and the conductive layer are laminated, and the laminate thus formed is laminated again to several stages. Thereafter, heat treatment is performed in a state where pressure is applied to the magnetic sheet and the conductive layer stacked at several stages. As a result, the cured magnetic sheet 100 having the binder resin is formed, and the laminated bodies 10 in which the conductive layers 210 and 220 are bonded 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.

7, the primer layers 311 and 321 are formed on the conductive layers 210 and 220 and the dried magnetic sheet 101 and the conductive layers 210 and 220 are formed on the primer layers 311 and 321 As shown in Fig.

The primer layer may include a thermosetting resin. Examples of the thermosetting resin used as the primer layer include epoxy resins and the like. The thickness of the primer layer may be about 0.1 to 20 탆. More specifically, the thickness of the primer layer may be about 1 to 7 mu m. The conductive layer on which the primer layer is formed is laminated on one side or both sides of the dried magnetic sheet. At this time, the primer layer is disposed in direct contact with the dried magnetic sheet. The binder contained in the dried magnetic sheet may be in a hardened or uncured state.

Thereafter, as shown in Fig. 8, the dried magnetic sheet and the conductive layer are laminated by heat and pressure. Accordingly, the dried magnetic sheet and the conductive layer can be laminated. At this time, the laminate may be carried out under heat and pressure conditions, and may be carried out under the temperature and pressure conditions exemplified above by the roll-to-roll process or batch process described above in detail.

As a result, the magnetic sheet 100 in which the hardening of the binder resin has been completed due to heat in the lapping step can be formed. Also, the primer layer is cured at the time of laminating, and the magnetic sheet and the conductive layer can be adhered to each other by the cured primer layer. That is, the cured primer layer may be formed of an adhesive layer that bonds the magnetic sheet and the conductive layer to each other. Accordingly, a conductive magnetic composite sheet in which the magnetic sheet 100 and the conductive layers 210 and 220 are bonded to each other through the adhesive layers 310 and 320 can be obtained.

According to an example, the adhesive layers 310 and 320 can have high chemical resistance because the thermosetting resin is formed by curing. Therefore, when the conductive layer is etched by the etching solution, the protective layer functioning to protect the magnetic powder contained in the magnetic sheet may be performed.

An antenna element according to an embodiment includes a magnetic sheet and an antenna pattern disposed on at least one side of the magnetic sheet, wherein the magnetic sheet has a magnetic permeability of 100 to 300 for an alternating current of 3 MHz frequency, , A magnetic permeability of 80 to 270 with respect to an alternating current of 13.56 MHz and a permeability of 60 to 250 with respect to an alternating current of 13.56 MHz and a temperature of 30 to 240 DEG C for 200 seconds at a constant rate, When the heat treatment is repeated twice under a condition that the temperature is lowered at a constant rate for 100 seconds up to 10%, and a permeability change of 10% or less.

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

Hereinafter, the constituent components of the antenna element will be described in detail.

The magnetic sheet included in the antenna element may have substantially the same configuration and composition as the magnetic sheet according to the embodiment described above, and may also be manufactured by substantially the same method.

The magnetic sheet has a magnetic permeability of 100 to 300 for an alternating current of 3 MHz frequency and a permeability of 80 to 270 for an alternating current of 6.78 MHz and a permeability of 60 to 250 for an alternating current of 13.56 MHz Lt; / RTI >

According to a specific example, the magnetic sheet comprises a magnetic powder in an amount of 70 to 95% by weight based on the total weight of the magnetic sheet, 6 to 12% by weight of a polyurethane resin as a binder resin, 0.5 to 2% % Of an isocyanate-based curing agent, and 0.3 to 1.5 wt% of an epoxy-based resin. In this case, the magnetic powder preferably has the composition of Formula 1, and the polyurethane resin includes the repeating units represented by the above formulas (2a) and (2b), wherein the isocyanate curing agent is an alicyclic diisocyanate, A type epoxy resin, cresol novolak type epoxy resin, or tetrakis (glycidyloxyphenyl) ethane type epoxy resin.

The antenna pattern is disposed on one or both surfaces of the magnetic sheet. At this time, the antenna pattern may be 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 planar coil shape, a spiral shape, or the like. Specifically, the antenna pattern may have a coil shape.

The antenna element may further include a via through the magnetic sheet. The vias contact all of the antenna patterns disposed on both sides of the magnetic sheet and electrically connect them.

The vias may comprise a conductive material. For example, the vias may comprise 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 first via-hole may be formed by plated the inner wall, filled with a conductive material, or inserted with a solder, a conductive rod or the like. As an example, the magnetic sheet includes a first via hole penetrating up and down, wherein the inner wall of the first via hole is plated to form the first via.

A method of manufacturing an antenna element according to an embodiment includes the steps of: (1) forming a conductive layer on at least one surface of a magnetic sheet; And (2) etching the conductive layer to form an antenna pattern, wherein the magnetic sheet has a magnetic permeability of 100 to 300 for an alternating current at a frequency of 3 MHz and an electrical conductivity of 80 for an alternating current at a frequency of 6.78 MHz, Having a permeability of 270 to 270 with a permeability of 60 to 250 for an alternating current at a frequency of 13.56 MHz, raising the temperature from 30 DEG C to 240 DEG C at a constant rate for 200 seconds, When the heat treatment is repeated twice under the condition of lowering the temperature at the speed, it has a thickness change of 10% or less and a permeability change of 10% or less.

The magnetic sheet may have substantially the same constitution and physical properties as the magnetic sheet according to the embodiment described above. As a specific example, the magnetic sheet includes a magnetic powder in an amount of 70 to 95% by weight based on the total weight of the magnetic sheet, 6 to 12% by weight of a polyurethane-based resin as a binder 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, wherein the magnetic powder has a composition represented by the formula (1), the polyurethane resin includes the repeating units represented by the above formulas (2a) and (2b), and the isocyanate- Group diisocyanate, and the epoxy resin may be a bisphenol A epoxy resin, a cresol novolak epoxy resin, or a tetrakis (glycidyloxyphenyl) ethane epoxy resin.

Further, the magnetic sheet can be manufactured under substantially the same conditions and by the same method as the method for producing a magnetic sheet according to the above-described embodiment.

Specifically, the magnetic sheet comprises: (a) mixing a polyurethane resin, an isocyanate curing agent, and an epoxy resin to prepare a binder resin; (b) mixing a magnetic powder and an organic solvent in the binder resin to prepare a slurry; And (c) shaping the slurry into a sheet form and drying the slurry.

The method of manufacturing the magnetic sheet may further include a step of thermally pressing the magnetic sheet at a pressure of 1 to 100 MPa and a temperature of 100 to 300 ° C after the step (c) to cure the binder resin in the magnetic sheet May be further included.

The conductive magnetic composite sheet is produced through the above step (1), and specific process conditions and methods are as exemplified in the method for producing the conductive magnetic composite sheet.

In the patterning in the step (2), a mask pattern is formed on the conductive layer by using a photoresist or the like, and the conductive layer is patterned by etching through the mask pattern. The etching may be performed using a conventional etching solution such as an aqueous acid solution. At this time, there may be little change in the thickness or permeability of the magnetic sheet due to the excellent chemical resistance of the magnetic sheet.

The manufacturing method of the antenna element may further include a step of forming a via through the magnetic sheet between steps (1) and (2).

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 pass through the magnetic sheet 100 and the conductive layers 210 and 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 conductive layers 210 and 220, and the conductive layer 210 is selectively etched by the mask pattern, as shown in FIG. 12C, 230 are formed. Preferably, since the magnetic sheet has improved chemical resistance, the thickness of the magnetic sheet in the etching process may be substantially unchanged.

Further, the binder resin (or adhesive layer) of the magnetic sheet adheres to the antenna pattern. That is, the binder resin (or adhesive layer) of the magnetic sheet is bonded to the antenna pattern by a heat curing process. Accordingly, in the etching process, the etching liquid does not penetrate between the magnetic sheet (or the adhesive layer) and the antenna pattern. As a result, the antenna pattern can be bonded to the magnetic sheet with an improved bonding force.

The antenna element according to the embodiment can reduce the thickness and simplify the manufacturing process by directly forming the conductive layer or the antenna pattern layer on the magnetic sheet without using an insulating substrate such as polyimide, WPC and MST. In addition, flexibility can be improved by using a polymer-type magnetic sheet, and manufacturing can be performed by a roll-to-roll process, thereby improving the processability.

In particular, the magnetic sheet can harden the binder resin by heat and can more firmly hold the magnetic powder, so that the magnetic sheet can be hardened even when various environmental changes such as etching treatment for patterning or reflow or soldering for application to a product, There may be little change in thickness.

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

According to one embodiment, referring to Fig. 9, the antenna element comprises a magnetic sheet 100; An antenna pattern 230 disposed on one surface of the magnetic sheet 100; A wiring pattern 240 disposed on the other surface of the magnetic sheet 100; And a first via 251 passing through the magnetic sheet 100. The first via 251 is connected to one end of the antenna pattern 230 and one end of the wiring pattern 240, do.

The antenna element according to the embodiment may further include a first terminal pattern 271 and a second terminal pattern 272 on one or both sides of the magnetic sheet 100, And a second via 252 penetrating through the second via 252. Designing various antenna elements is possible according to their arrangement position and connection configuration.

10A to 10C show plan views of antenna elements according to various exemplary configurations. Among the patterns, the black pattern is the front pattern, the hatched pattern is the rear 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.

First, referring to FIG. 10A, the antenna element according to the specific embodiment includes a first terminal pattern 271 disposed on one 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 first terminal pattern 271 and the other end of 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, wherein the other end of the antenna pattern 230 contacts the second terminal pattern 272, Lt; / RTI > At this time, the first terminal pattern 271 and the second terminal pattern 272 may be disposed adjacent to each other.

10B, 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 the magnetic sheet 100. The second via 252 is connected to the second terminal pattern 272 and the other end of the antenna pattern 230 . At this time, the first terminal pattern 271 and the second terminal pattern 272 may be disposed adjacent to each other.

10C, 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 formed on the other end of the antenna pattern 230. [ Can be connected.

In the antenna element according to the embodiment, the antenna pattern and the wiring pattern are made of a conductive material, the antenna pattern is directly bonded to one surface of the magnetic sheet, and the wiring pattern is directly bonded to the other surface of the magnetic sheet .

The antenna element according to the above specific embodiment can generate the electromagnetic signal 50 due to the current flowing through the antenna pattern with reference to FIG. The electromagnetic signal 50 enables signal transmission / reception between the antenna element 20 and the external terminal 40.

The antenna element according to the above specific embodiment is characterized in that the 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, 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 231, a plurality of second conductive line patterns 232, (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.

FIG. 14 illustrates a portion of a portable terminal to which an antenna element according to another embodiment of the present invention is applied. 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: Fabrication of antenna element

Step 1) Preparation of magnetic powder slurry

42.8 parts by weight of sandstock 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% by weight, n-butyl acetate: 3% by weight, 2-butanone: 15% by weight, toluene: 13% by weight) 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 powder slurry.

Step 2) Production of magnetic sheet

The previously prepared magnetic powder slurry was coated on a carrier film with a comma coater and dried at a temperature of about 110 캜 to form a dried magnetic sheet. The dried magnetic sheet was compression-cured by a hot press process at a temperature of about 170 캜 and a pressure of about 9 MPa for about 30 minutes to obtain a final magnetic sheet.

Step 3) Production of the copper-clad laminated magnetic composite sheet

An epoxy resin was coated on one side of a copper foil having a thickness of about 37 mu m to form a primer layer having a thickness of about 4 mu m. The copper foil was disposed on both sides of the magnetic sheet, and the laminate was formed such that the primer layer was positioned between the magnetic sheet and the copper foil. Thereafter, the laminate was pressed by a hot press process at a temperature of about 170 캜 and a pressure of about 9 MPa for about 60 minutes to cure the primer layer, thereby manufacturing a copper-clad laminated magnetic composite sheet.

Step 4) Manufacture of antenna element

By using a drill, a plurality of via-holes having a diameter of about 0.15 mm were formed in the above-mentioned copper-clad laminated magnetic composite sheet. Thereafter, a copper plating layer was formed in the via-holes through a copper plating process. The plating layer served as vias connecting the copper foils on the upper and lower sides to each other. 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. Accordingly, the upper patterns and the lower patterns were formed.

The magnetic sheet prepared in the step (2) of Example 1, the copper-clad laminated magnetic composite sheet prepared in the step (3) and the antenna element produced in the step (4) were tested according to the following procedure.

Test Example 1. Measurement of permeability

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

@ 3 MHz @ 6.78 MHz @ 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 according to the embodiment had excellent permeability in all three bands.

Test Example 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, no blister was observed on the surface of the magnetic sheet even after the second reflow test. Further, after the second reflow test, both the thickness of the magnetic sheet and the permeability change were measured to be less than 5%. Further, the peel strength of the magnetic sheet with the copper foil after the second reflow test was measured to be 0.6 kgf / cm or more.

Test Example 3. Heat Resistance Measurement - Pb Floating Test

After the magnetic sheet and the copper-clad laminated magnetic composite sheet were placed in a fused bath and allowed to stand for 40 seconds, the surface was observed. As a result, no blister was observed on the surfaces of the magnetic sheet and the copper-clad laminated magnetic composite sheet.

Test Example 4. Measurement of Chemical Resistance

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%.

Test Example 5. Measurement of rust-inhibiting properties

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. .

Test Example 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.

Test Example 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.

Test Example 8. Measurement of high temperature and high humidity characteristics

After the magnetic sheet was allowed to stand in a constant temperature and humidity oven at 85 ° C / 85% RH for 72 hours, the change in the thickness of the magnetic sheet and the change in the magnetic permeability were measured. As a result, both the change in the thickness of the magnetic sheet and the change in the magnetic permeability were all measured to be 5% or less.

10: laminate,
20: an antenna element according to the embodiment, 20 ': a conventional antenna element,
30: case, 30 ': metal case,
31: Electromagnetic wave non-transmission area, 32: Electromagnetic wave transmission area,
40, 40 ': external terminal, 50, 50': electromagnetic signal,
100: magnetic sheet (cured)
101: a dry magnetic sheet (in which curing is not completed)
110: magnetic powder,
120: binder resin (cured)
121: binder resin (not cured)
210, 220: conductive layer, 230: antenna pattern,
231: first conductive line pattern, 232: 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,
310, 320: adhesive layer, 311, 321: primer layer,
400: carrier film, 500: coater,
600: Roll,
CR: core region, OR: peripheral region.

Claims (15)

1. A magnetic sheet comprising a magnetic powder and a thermosetting binder resin,
The magnetic sheet is a non-solidified cured sheet having a thickness of 10 to 500 占 퐉 which has flexibility,
The magnetic powder is contained in an amount of 70 to 90% by weight based on the total weight of the magnetic sheet, the binder resin is contained in an amount of 5 to 20% by weight,
Having a permeability of 100 to 300 for an alternating current of 3 MHz frequency,
Having a permeability of 80 to 270 for alternating current at a frequency of 6.78 MHz,
Having a permeability of 60 to 250 for an alternating current at a frequency of 13.56 MHz,
It has a thickness change of less than 5% and a permeability change of less than 5% when immersed in a 2N hydrochloric acid solution for 30 minutes and has a thickness change of less than 5% and a permeability change of less than 5% when immersed in 2N sodium hydroxide solution for 30 minutes ,
The temperature is raised from 30 ° C. to 240 ° C. at a constant rate for 200 seconds, and then the temperature is lowered at a constant rate from 240 ° C. to 130 ° C. for 100 seconds. When the heat treatment is repeated twice, Having a permeability change of 5% or less,
Having a volume change of 5% or less when heat treated at 150 ° C for 30 minutes.
The method according to claim 1,
Wherein said magnetic sheet is comprised of a single layer and has a permeability change of less than or equal to 5% after 100 bending in an MIT folding test at 90 and 35 RPM conditions.
The method according to claim 1,
The magnetic sheet was heated at a constant rate from 30 ° C. to 240 ° C. for 200 seconds, and then heat-treated at 240 ° C. to 130 ° C. at a constant rate for 100 seconds. And a magnetic permeability change of 3% or less.
The method according to claim 1,
Wherein the magnetic sheet comprises a magnetic powder in an amount of 80 to 90% by weight based on the total weight of the magnetic sheet.
5. The method of claim 4,
Wherein the magnetic powder has a composition of the following formula (1): Magnetic sheet:
[Chemical Formula 1]
Fe _1-abc Si _a X _b Y _c
In this formula,
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 method according to claim 1,
Wherein the binder resin comprises a polyurethane resin, an isocyanate curing agent, and an epoxy resin.
The method according to claim 6,
The polyurethane resin includes repeating units represented by the following general formulas (2a) and (2b)
The isocyanate-based curing agent is an alicyclic diisocyanate,
Wherein the epoxy resin is a bisphenol A type epoxy resin, a cresol novolak type epoxy resin, or a tetrakis (glycidyloxyphenyl) ethane type epoxy resin,
[Chemical Formula 2b]

In this formula,
R ₁ and R ₃ are each independently a C _1-5 alkyl group, urea or ether group;
R ₂ and R ₄ are each independently a C _1-5 alkyl group;
Each of R ₁ to R ₄ may independently have at least one substituent selected from the group consisting of halogen, hydroxy, cyano, amino and nitro.
The method according to claim 1,
The magnetic sheet is characterized in that, based on the total weight of the magnetic sheet,
The magnetic powder is contained in an amount of 80 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.
A conductive magnetic composite sheet comprising a magnetic sheet and a conductive layer directly bonded on at least one surface of the magnetic sheet by heat and pressure without a separate adhesive layer,
Here,
Based on the total weight of the magnetic sheet, 70 to 90% by weight of a magnetic powder and 5 to 20% by weight of a thermosetting binder resin,
Is a non-cured, hardened sheet having a thickness of 10 to 500 占 퐉,
Having a permeability of 100 to 300 for an alternating current of 3 MHz frequency,
Having a permeability of 80 to 270 for alternating current at a frequency of 6.78 MHz,
Having a permeability of 60 to 250 for an alternating current at a frequency of 13.56 MHz,
It has a thickness change of less than 5% and a permeability change of less than 5% when immersed in a 2N hydrochloric acid solution for 30 minutes and has a thickness change of less than 5% and a permeability change of less than 5% when immersed in 2N sodium hydroxide solution for 30 minutes ,
The temperature is raised from 30 ° C. to 240 ° C. at a constant rate for 200 seconds, and then the temperature is lowered at a constant rate from 240 ° C. to 130 ° C. for 100 seconds. When the heat treatment is repeated twice, Having a permeability change of 5% or less and having a volume change of 5% or less when heat-treated at 150 DEG C for 30 minutes.
10. The method of claim 9,
The conductive magnetic composite sheet
When the temperature is raised from 30 ° C. to 240 ° C. at a constant rate for 200 seconds and then the temperature is lowered at a constant rate from 240 ° C. to 130 ° C. for 100 seconds, And a peel strength of 0.6 kgf / cm or more.
1. An antenna element comprising a magnetic sheet and an antenna pattern disposed on at least one side of the magnetic sheet,
Wherein the antenna pattern is formed by directly bonding a conductive layer to one surface of the magnetic sheet by heat and pressure without using an adhesive layer,
Here,
Based on the total weight of the magnetic sheet, 70 to 90% by weight of a magnetic powder and 5 to 20% by weight of a thermosetting binder resin,
Is a non-cured, hardened sheet having a thickness of 10 to 500 占 퐉,
Having a permeability of 100 to 300 for an alternating current of 3 MHz frequency,
Having a permeability of 80 to 270 for alternating current at a frequency of 6.78 MHz,
Having a permeability of 60 to 250 for an alternating current at a frequency of 13.56 MHz,
It has a thickness change of less than 5% and a permeability change of less than 5% when immersed in a 2N hydrochloric acid solution for 30 minutes and has a thickness change of less than 5% and a permeability change of less than 5% when immersed in 2N sodium hydroxide solution for 30 minutes ,
The temperature is raised from 30 ° C. to 240 ° C. at a constant rate for 200 seconds, and then the temperature is lowered at a constant rate from 240 ° C. to 130 ° C. for 100 seconds. When the heat treatment is repeated twice, Having a permeability change of less than or equal to 5% and having a volume change of less than or equal to 5% when heat treated at 150 占 폚 for 30 minutes.
12. The method of claim 11,
The magnetic sheet is characterized in that, based on the total weight of the magnetic sheet,
The magnetic powder is contained in an amount of 80 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.
(1) directly bonding the conductive layer on at least one surface of the magnetic sheet by heat and pressure without a separate adhesive layer; And
(2) etching the conductive layer to form an antenna pattern, the method comprising the steps of:
Here,
Based on the total weight of the magnetic sheet, 70 to 90% by weight of a magnetic powder and 5 to 20% by weight of a thermosetting binder resin,
Is a non-cured, hardened sheet having a thickness of 10 to 500 占 퐉,
Having a permeability of 100 to 300 for an alternating current of 3 MHz frequency,
Having a permeability of 80 to 270 for alternating current at a frequency of 6.78 MHz,
Having a permeability of 60 to 250 for an alternating current at a frequency of 13.56 MHz,
It has a thickness change of less than 5% and a permeability change of less than 5% when immersed in a 2N hydrochloric acid solution for 30 minutes and has a thickness change of less than 5% and a permeability change of less than 5% when immersed in 2N sodium hydroxide solution for 30 minutes ,
The temperature is raised from 30 ° C. to 240 ° C. at a constant rate for 200 seconds, and then the temperature is lowered at a constant rate from 240 ° C. to 130 ° C. for 100 seconds. When the heat treatment is repeated twice, Having a permeability change of 5% or less and having a volume change of 5% or less when heat-treated at 150 DEG C for 30 minutes.
14. The method of claim 13,
The magnetic sheet
(a) mixing a polyurethane resin, an isocyanate curing agent, and an epoxy resin to prepare a binder resin;
(b) mixing a magnetic powder and an organic solvent in the binder resin to prepare a slurry; And
(c) shaping the slurry into a sheet form and drying the slurry.
15. The method of claim 14,
The method of manufacturing the magnetic sheet may further include, after the step (c)
Heating the magnetic sheet at a pressure of 1 to 100 MPa and a temperature of 100 to 300 DEG C to cure the binder resin in the magnetic sheet.

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