KR20170038751A - Magnetic shielding unit for wireless power transmission, wireless power transmission module comprising the same and electronic device comprising the same - Google Patents

Abstract

The present invention provides a magnetic field shielding unit for wireless power transmission. According to an embodiment of the present invention, the magnetic field shielding unit for wireless power transmission includes a magnetic field shielding layer which has Ni-Zn-Cu-based ferrite fragments crushed to improve the flexibility of the magnetic field shielding unit. The Ni-Zn-Cu-based ferrite fragments have a real part () of complex permeability of 170 or more at the frequency of 6.78 MHz. Accordingly, the present invention can prevent a magnetic field from affecting the body of a user or components of a mobile terminal and significantly increase combined antenna properties even when various types of antennas with various purposes, structures, shapes, sizes, and unique properties such as inductance and resistivity are combined.

Description

TECHNICAL FIELD [0001] The present invention relates to a magnetic shielding unit for wireless power transmission, a wireless power transmission module including the wireless power transmission module, and an electronic apparatus including the wireless power transmission module.

Field of the Invention [0002] The present invention relates to a magnetic shielding unit, and more particularly, to a magnetic shielding unit for wireless power transmission, a wireless power transmission module including the same, and an electronic apparatus.

Wireless power technologies of portable electronic devices such as mobile phones, personal digital assistants (PDAs), iPads, notebook computers, and tablet PCs are emerging. The new type of wireless power transmission technology is a technology that enables a portable electronic device to charge a battery by directly transmitting electric power to a portable electronic device by adopting an electromagnetic induction method or an electromagnetic resonance method without a power line, There is an increasing trend of electronic devices.

The magnetic resonance method basically differs from the magnetic induction method in that a current is converted into an electromagnetic current through a coil, but the resonance frequency is transmitted to the resonance frequency. In addition, the self resonance system includes a capacitor and a coil in the wireless power transmission module and the wireless power reception module, so that resonance occurs in a predetermined frequency band, and wireless power transmission is performed.

The wireless power transmission efficiency of the self-resonant system is improved as the magnetic field oscillating at the resonance frequency generated in the primary coil is intensively received in the secondary coil. To this end, the direction of the magnetic field is concentrated on the received antenna, The electromagnetic shielding material is generally provided in each of the transmitting and receiving modules. If the generated magnetic field leaks without being focused on the receiving antenna, the wireless power transmission efficiency and the wireless power transmission distance may be reduced. In addition, the leaked magnetic field may cause problems such as deterioration of performance of other components in the electronic device equipped with the wireless power transmission module, generation of heat, and the like, and may adversely affect the human body of the electronic device user.

On the other hand, in recent years, electronic devices including a wireless power transmission module have been designed to have a reduced thickness of modules due to the tendency to be thinner and thinner, and electromagnetic shielding materials provided in the modules are also required to be designed to be ultra-thin . However, the ferrite magnetic material, which is often used as the magnetic material of the electromagnetic shielding material, is very strong in brittleness. When the thin ferrite magnetic material is manufactured to have a thin thickness, it is required to attach the adherend to the antenna, for example, Even when the electromagnetic shielding material is easily cracked due to the impact or external force applied during the manufacturing process and / or use of the electronic equipment and the initial design property of the electromagnetic shielding material is designed to be high, So that the wireless power transmission distance is shortened, and the wireless power signal transmission / reception efficiency is significantly reduced.

As a result, the characteristics of the wireless power transmission antenna are remarkably improved, the manufacturing process of the shielding unit and the portable device using the shielding unit, and the occurrence of a crack in the magnetic body even during the impact applied during use thereof It is urgently necessary to study a magnetic shielding unit capable of continuously maintaining initial physical property values.

Korean Patent Publication No. 10-1374525

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and it is an object of the present invention to provide a magnetic recording medium, which can prevent the influence of a magnetic field on a component such as an electronic apparatus or a human body of a user, A magnetic field shielding unit for wireless power transmission capable of remarkably increasing the characteristics of an antenna to be combined even when combined with antennas for wireless power transmission of the same type and continuously exhibiting initially designed physical properties and ensuring product quality for a long time The purpose is to provide.

In addition, the present invention enables wireless power transmission of a self-resonance method using a frequency band ranging from several tens of kHz to several MHz as an operating frequency through the magnetic shielding unit according to the present invention, There is another purpose of providing a wireless power transmission module that can be used for a wireless communication.

It is yet another object of the present invention to provide a wireless power transmission module capable of simultaneously improving characteristics of antennas even in an antenna unit having antennas for different purposes through a magnetic field shield unit according to the present invention.

It is another object of the present invention to provide an electronic device such as a portable device in which the reception efficiency and reception distance of a wireless power signal are remarkably increased through the wireless power transmission module according to the present invention.

In order to solve the above-described problems, the present invention provides a magnetic shielding layer formed of Ni-Zn-Cu ferrite fragments that are crushed to improve the flexibility of a shielding unit, The nickel-zinc (Zn) -couple (Cu) ferrite provides a magnetic shielding unit for radio power transmission having a real part μ 'of complex permeability of 170 or more at a frequency of 6.78 MHz.

According to an embodiment of the present invention, the magnetic shield layer may further include a protective member disposed on one surface of the magnetic shield layer and a first adhesive member disposed on the other surface of the magnetic shield layer.

The nickel (Ni) -Zn (Cu) -based ferrite may have a real part (μ ') of the complex permeability of 200 or more at a frequency of 100 kHz. More preferably, the imaginary part (mu ") of the complex permeability at a frequency of 100 kHz can be 10 or less, more preferably 6 or less.

The ferrite of the nickel-zinc (Zn) -copper (Cu) type has a real part (μ ') of the complex permeability at a frequency of 100 kHz of 150 or more and an imaginary part (μ " ) Is 5 or less, more preferably 2 or less.

In addition, the single piece shape of the ferrite pieces may be irregular, and some of the pieces of the ferrite pieces may have a curved shape, at least one side of which is not a straight line. Preferably, May be at least 45%, more preferably at least 60% of the total number of ferrite fragments.

In addition, the average particle size of the single debris of the ferrite fragments may be 100 to 2000 탆.

The magnetic shield unit may have a quality index value of 45 or more at a frequency of 6.78 MHz according to Equation (1).

[Equation 1]

The ferrite may include 8 to 15 mol% of nickel oxide (NiO), 25 to 35 mol% of zinc oxide (ZnO), and 8 to 13 mol% of copper oxide (CuO). At this time, the ferrite may further include 0.2 to 0.35 mol% of cobalt tetraoxide (Co ₃ O ₄ ).

In addition, a plurality of the magnetic shielding layers are stacked, and a second adhesive member may be interposed between adjacent magnetic shielding layers of the plurality of magnetic shielding layers.

In addition, the ferrite fragments may include 30% or more of fragments having a degree of variability of 8.0 or less according to the following formula (2).

&Quot; (2) "

The present invention also relates to an antenna unit including an antenna for wireless power transmission; And a magnetic field shielding unit for wireless power transmission according to the present invention, disposed on one surface of the antenna unit, for improving antenna characteristics for wireless power transmission and focusing a magnetic field toward the antenna.

According to an embodiment of the present invention, the antenna unit may further include at least one antenna for a magnetic security transmission (MST) antenna and a near field communication (NFC) antenna.

The present invention also provides an antenna unit including an antenna for wireless power transmission having a frequency band including a frequency of 6.78 MHz as an operating frequency and a short-range communication antenna having a frequency band including a frequency of 13.78 MHz as an operating frequency; And a magnetic field shielding unit disposed on one surface of the antenna unit to improve the characteristics of the antenna for short range communication and the antenna for wireless power transmission and to focus the magnetic field toward each antenna.

According to an embodiment of the present invention, the antenna unit may further include an antenna for magnetic security transmission (MST).

The present invention also provides an electronic apparatus including the wireless power transmission module according to the present invention.

In addition, the present invention provides a portable device including a module for wireless power transmission according to the present invention as a receiving module.

According to the present invention, the magnetic field shielding unit for wireless power transmission is capable of shielding the influence of the magnetic field on parts such as electronic apparatuses or the human body of the user, and at the same time, various kinds of electromagnetic waves having various structures, shapes, sizes and intrinsic characteristics (inductance, The characteristics of the combined antenna can be increased even if it is combined with the antennas for the wireless power transmission of the self resonance type.

In addition, even if the magnetic substance itself has high brittleness, flexibility of the shielding unit is remarkably excellent, so that even if the shielding unit is thinned, the shielding unit can be safely stored, transported, attached to the adherend, Cracks and micro-fragmentation of the magnetic body due to an external force such as a drop impact can be prevented, thereby preventing fluctuation or deterioration of properties such as initial designed magnetic permeability.

Furthermore, even if there is a step on the surface of the adherend due to its excellent flexibility, it can be adhered with excellent adhesion.

In addition, the magnetic field shielding unit according to the present invention can further improve the characteristics of the antenna for wireless power transmission, thereby significantly increasing the power transmission efficiency and transmission distance, and accordingly, the wireless power transmission module, And can be widely applied to various electronic devices such as a smart appliance or a device for the Internet of Things.

1 is a cross-sectional view of a magnetic-field shielding unit for wireless power transmission according to an embodiment of the present invention,
FIG. 2 is a schematic view showing the shape of debris observed on one surface of a magnetic shielding layer formed of ferrite shards in a magnetic shielding unit according to an embodiment of the present invention; FIG.
FIGS. 3 and 4 are diagrams showing the circumscribed circle diameter and the inscribed circle diameter of the fragments for evaluating the degree of variability of ferrite fragments having an irregular shape,
5 and 6 are schematic views illustrating a manufacturing process using a crushing apparatus used for manufacturing a magnetic field shielding unit according to an embodiment of the present invention, and FIG. 5 is a schematic view illustrating a manufacturing method of a magnetic field shielding unit using a crushing apparatus for crushing a ferrite sheet FIG. 6 is a view showing a manufacturing process using a crushing apparatus for crushing a ferrite sheet through a metal ball provided in a support plate, FIG.
7 is a sectional view of a magnetic power unit for wireless power transmission according to an embodiment of the present invention having a magnetic shielding layer formed of ferrite pieces in three layers,
8 is an exploded perspective view of a wireless power transmission module according to an embodiment of the present invention, and FIG.
9 is an exploded perspective view of a wireless power transmission module according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art to which the present invention pertains. The present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same reference numerals are assigned to the same or similar components throughout the specification.

1, a magnetic shielding unit 100 for wireless power transmission according to an embodiment of the present invention includes a magnetic shielding layer 110, and the magnetic shielding layer 110 is formed of a Ni- And is formed of fragments 111 of zinc (Zn) -copper (Cu) -based ferrite. The magnetic shielding unit 100 further includes a protection member 140 disposed on the magnetic shielding layer 110 and a first adhesive member 130 disposed on the lower portion of the magnetic shielding layer 110 And the adhesive member 130 may further include a release film 130a for protecting the first adhesive layer 130b and the first adhesive layer 130b until the magnetic shielding unit 100 is attached to the adherend have.

First, the magnetic shielding layer 110 is formed of ferrite pieces 111 in which a nickel-zinc (Zn) -copper (Cu) ferrite sheet is crushed to improve the flexibility of the shielding unit.

In order to make the magnetic shielding unit slimmer and thinner, the thickness of the magnetic body to be provided must be very thin at the same time. When the thickness of the ferrite sheet is thinner than that of nickel-zinc (Zn) When a crack occurs on a very weak external force, or when the crack is broken due to micro-fragments, when the crack is generated on a sheet, the magnetic properties such as permeability change after cracking, and when the micro fragmentation deepens, There is a problem that the set initial property value can not be maintained.

In addition, the magnetic shielding unit having a very thin ferrite structure is required to be handled in order to prevent cracking when it is stored, transported, and put into the assembly process, thereby significantly reducing workability. Specifically, the magnetic shielding unit is usually disposed on the surface on which the antenna is formed, and is generally adhered to the surface of the antenna on which the antenna is formed so as to improve the antenna characteristics and prevent the magnetic shielding unit from escaping. Referring to FIG. 1, the magnetic shielding unit 100 may be attached to an adherend surface (not shown) through a first adhesive member 130, The removal work of the release film 130a for protecting the first adhesive layer 130b is preceded. However, in order to peel off the release film 130a from the magnetic field shielding unit 100, an external force equal to or higher than a certain level is required. However, when the thickness of the ferrite sheet is extremely thin, as cracks are easily generated by an external force for peeling off the release film, There is a problem in that the workability is deteriorated because a very large amount of water is applied even in the work of peeling off. In addition, even when a portable device is manufactured with a great effort to prevent cracks from occurring in the ferrite sheet, cracks and brittleness of the ferrite sheet are generated due to impacts such as dropping during use. Thus, various kinds of data The transmission and reception efficiency of the signal and the wireless power signal and the transmission / reception distance can not be secured.

However, since the magnetic shielding unit 100 according to the present invention is formed of a nickel-zinc (Zn) -couple (Cu) ferrite, which is a magnetic material, Even if the cross-sectional thickness of the shielding unit is made thinner, there is a possibility that the additional micro-fragmentation of the ferrite due to the external force is essentially blocked. In addition, the magnetic shielding layer is suitably provided with the ferrite in the form of a piece of material so as to exhibit excellent characteristics in the wireless power transmission, and the initial physical property value is used in the manufacturing step of the finished product in which the shielding unit is mounted, It is possible to eliminate the possibility of deterioration of the physical properties due to unintentional fragmentation occurring in the shielding unit having the ordinary non-fragmented magnetic body and deterioration of transmission / reception performance of the wireless power signal due to this.

Meanwhile, the shape of the nickel (Ni) - zinc (Zn) -copper (Cu) ferrite fragments 111 may be irregular. However, it is advantageous in terms of physical properties that the gap formed between the fragments is fragmented such that there is no gap between the fragments due to the leakage of the magnetic material and the deterioration of the physical properties. In this case, the intention that may be caused by the deflection or bending of the shielding unit Further, in order to prevent the occurrence of fluctuation or deterioration of physical properties, at least one side of some of the fragments may be crushed to have a curved shape instead of a straight line (See FIG. 2). When the shield has a curved shape, it is possible to reduce the adjacent debris and the collision or friction when the shield unit is bent, thereby preventing the additional debris of the debris.

More preferably, the number of the fragments having at least one curved shape may be 45% or more, more preferably 60% or more, of the total number of fragments in the magnetic shield layer. If the number of fragments having a curved shape of at least one side is less than 45% of the total number of fragments, the improvement in flexibility may be insignificant, and an external impact may increase the fragments smaller than the fragments provided at the beginning, And the like.

In addition, the average particle size of the single debris of the nickel (Ni) -Zn (Zn) -copper (Cu) ferrite fragments 111 may be 100 to 2000 μm. If the average particle diameter is more than 2000 mu m, it may be difficult to maintain the initial physical property design value of the magnetic shielding unit due to an increase in breakage and fragmentation of additional fragments. If the average particle size of the debris is less than 100 탆, it is necessary to select the ferrite having a high magnetic property value such as the permeability of the ferrite before crushing. However, since the manufacturing of the ferrite having a high permeability is limited, It is difficult to design the initial physical properties. On the other hand, the average particle diameter of the debris is a result measured based on the volume average diameter measured by a laser diffraction particle size distribution meter.

In order to further prevent breakage and fragmentation of the ferrite fragments, the nickel-zinc (Zn) -copper (Cu) ferrite fragments 111 preferably have a ratio of It may contain 30% or more fragments with a deviation of 8.0 or less.

&Quot; (2) "

Equation (2) in the circumscribed circle diameter is meant the presence longest distance of the distances between any two points on any one surface of the fragments of debris (Fig. 3 R _1, in FIG. 4 R _2), and two of the fragments in the longest The circle passing through the point corresponds to the circumscribed circle of the fragment. The diameter of the inscribed circle of the fragment means the diameter of the inscribed circle having the largest diameter among the inscribed circles in contact with at least two sides present on either side of the fragment (r ₁ in FIG. 3 and r ₂ in FIG. 4). The large degree of deformation of one side of the debris means that the shape of the one side of the debris is long (see FIG. 3), and it is highly likely to include the pointed portion (see FIG. 4) .

Accordingly, it is preferable that the number of fragments having a large degree of differentiation among the nickel-zinc (Zn) -couple (Cu) -based ferrite fragments 111 included in the magnetic shielding layer 110 is less than a predetermined ratio, More than 30% of the fragments having a one-sided degree of deformation of 8.0 or less among the fragments in the shielding layer 110 according to the formula (2) may be included, more preferably 45% or more, More than 60% can be included. If the degree of debris is less than 30%, there is a problem that microfragmentation of the additional ferrite fragments may cause a significant deterioration of physical properties such as permeability and the desired initial property design value may not be maintained.

Meanwhile, the magnetic shielding layer 110 according to the present invention includes nickel-zinc (Zn) -couple (Cu) -based ferrite as a magnetic material, and preferably cobalt (Co) . The nickel (Ni) - zinc (Zn) - copper (Cu) ferrite is very advantageous for improving the antenna characteristics for the self-resonant radio power transmission in the radio power transmission operating frequency band of the self resonance system.

There is no limitation on the composition, crystal type, and microstructure of the sintered particles when the ferrite of the nickel (Ni) -Zn (Zn) -copper (Cu) type can exhibit permeability properties of the magnetic shielding unit described later in a fragmented state . However, preferably, the crystal structure of the nickel (Ni) -zinc (Zn) -couple (Cu) ferrite may be spinel type. More preferably, the Ni-Zn-Cu ferrite is used in an amount of 8 to 15 mol% of nickel oxide (NiO), 25 to 35 mol% of zinc oxide (ZnO) (CuO) in an amount of 8 to 13 mol%. At this time, the amount of the ferric trioxide may be 37 to 50 mol%.

If the content of nickel oxide is less than 8 mol%, the resonance frequency of the complex permeability shifts to the lower frequency side, the real part of the complex permeability decreases at the desired self resonance frequency, and the imaginary part is significantly increased, The power transmission efficiency may be significantly reduced. If the content of nickel oxide exceeds 15 mol%, reduction of the real part of the complex permeability may become significant at a desired self-resonant frequency, and the resistance of the ferrite may decrease, which may cause heat generation due to an increase in eddy current generation. If the content of zinc oxide is less than 25 mol%, the real part of the complex permeability can be reduced in the intended self-resonant frequency band. If the amount of zinc oxide is increased by 35 mol%, the imaginary part of the complex permeability increases remarkably And heat generation due to eddy currents may occur. If the content of copper oxide is less than 8 mol%, the real part of the complex permeability can be reduced in the desired self-resonant frequency band. If the content exceeds 13 mol%, the growth of particles during sintering is not normal, Can be significantly increased.

The Ni-Zn-Cu ferrite may be a Ni-Zn-Cu-Co ferrite further containing cobalt tetraoxide (Co ₃ O ₄ ), more preferably 0.2 to 0.35 mol% of cobalt tetraoxide, , Still more preferably 0.30 to 0.35% of cobalt tetraoxide. By further including cobalt tetroxide, it may be advantageous to develop more suitable physical properties for the wireless power transmission of the self-resonance method.

On the other hand, the composition and the composition ratio of the ferrite are not limited thereto and can be changed according to the desired properties.

The thickness of the magnetic shielding layer 110 may be a thickness of a ferrite sheet derived from nickel-zinc (Zn) -couple (Cu) ferrite fragments 111, and the thickness of the magnetic shielding layer 110 ) May be 30 to 600 mu m. If the average thickness is less than 30 mu m, the magnetic characteristics may not be exhibited to the desired level, and when the average thickness is more than 600 mu m, it is not preferable to make the shielding unit thinner.

In addition, the shape of the magnetic shielding layer may be formed in a shape other than a rectangle or square so as to correspond to the application to which the magnetic shielding unit is applied, specifically, the wireless power transmission antenna, the wireless power transmission antenna, and / A polygon such as a pentagon, a circle, an ellipse, or a shape in which a curve and a straight line partially exist. At this time, the size of the magnetic shielding unit is preferably about 1 to 2 mm larger than the antenna size of the corresponding module.

1 or 13, a protective film 140a having a base film 140a and a second adhesive layer 140b formed on one surface of the base film 140a is formed on the magnetic shielding layers 110 and 110 ' A first adhesive member 130 (130) having a release film 130a and a first adhesive layer 130b formed on one side of the release film 130a is disposed under the magnetic shielding layers 110 and 110 ' ).

First, the base film 140a of the protective member 140 may be a protective film normally provided in the magnetic shielding unit. In the process of attaching the shielding sheet to the substrate having the antenna, the heat / pressure And the film is made of a material whose mechanical strength and chemical resistance are sufficient to protect the magnetic shielding layers 110 and 110 'against external physical and chemical stimuli Can be used. As a non-limiting example, polypropylene, polyimide, crosslinked polypropylene, nylon, polyurethane resin, acetate, polybenzimidazole, polyimideamide, polyetherimide, polyphenylene sulfide (PPS). (PET), polytrimethylene terephthalate (PTT) and polybutylene terephthalate (PBT), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE) and polychlorotrifluoroethylene PCTFE), and polyethylene tetrafluoroethylene (ETFE), which may be used alone or in combination.

The base film 140a may have a thickness of 1 to 100 탆, preferably 10 to 30 탆, but is not limited thereto.

The protective member 140 may include a second adhesive layer 140b on one surface of the base film 140a and the protective member 140 may be bonded to the magnetic shielding layer 110 through the second adhesive layer 140b. Lt; / RTI > The second adhesive layer 140b may be a conventional adhesive layer without limitation and may be a double-sided tape-type adhesive layer formed as a single layer through an adhesive layer forming composition or an adhesive layer forming composition formed on both sides of a supporting film. The thickness of the second adhesive layer 140b may be 3 to 50 탆, but the present invention is not limited thereto.

Next, the first adhesive member 130 serves to attach the magnetic-field-shielding units 100 and 100 'to an antenna or a substrate provided with an antenna. 1, the first adhesive member 130 may include a first adhesive layer 130b for attaching the magnetic field shielding unit 100 or 100 'to the surface to be attached, and the first adhesive layer 130 130b of the release film 130a. The release film 130a can be used without limitation in the case of a conventionally known release film which can be easily removed from the first adhesive layer 130b, but the present invention is not particularly limited thereto.

The first adhesive layer 130b may be formed by applying an adhesive layer forming composition to the lower portion of the magnetic shielding layer 110 or 110'or forming a first adhesive layer 130b formed by applying an adhesive composition on the release film 130a, And may be attached to the shielding layers 110 and 110 '. Also, the first adhesive layer 130b may be a double-sided adhesive layer in which the adhesive layer-forming composition is coated on both sides of the support film to reinforce the mechanical strength. The thickness of the first adhesive layer 130b may be 3 to 50 탆, but is not limited thereto, and may be changed according to the purpose.

Although the magnetic shielding units 100 and 100 'according to the present invention are formed from a nickel-zinc (Zn) -couple (Cu) ferrite in a fragmented state from the beginning to form a magnetic shielding layer, (Zn) -copper (Cu) -based ferrite in a bulk state and a real part of a complex permeability at a frequency of 100 kHz in order to remarkably improve the characteristics of the transmission antenna and to focus the magnetic field toward the antenna mu ') is 170 or more, and preferably the real part (mu') is 200 or more. For example, the real part may be 500 or less. Preferably, in order to further improve the antenna characteristic, the imaginary part 占 of the complex permeability at the frequency may be 10 or less, and preferably 6 or less. If the real part of the complex permeability at the frequency is less than 170, It is not possible to achieve the wireless power transmission efficiency and if one of the possible micro-fragmentation of the ferrite debris that can occur can not satisfy the level of physical property necessary for the wireless power transmission, the product may be defective.

In order to further improve the wireless power transmission efficiency and charge distance, the nickel-zinc (Zn) -copper (Cu) ferrite has a quality index value according to Equation 1 below at a frequency of 6.78 MHz in a bulk state, May be 45 or more, and more preferably 50 or more.

 [Equation 1]

The increase in the value of the quality index means that the real part of the complex permeability increases, the imaginary part does not change, or the real part of the complex permeability is constant, the imaginary part decreases or the real part increases and the imaginary parts decrease simultaneously In either case, the improved wireless power transmission efficiency and charging distance can be increased. If the quality index is less than 45 at a frequency of 6.78 MHz, the improvement of the radio power transmission efficiency may be insignificant or the magnetic loss may increase.

The magnetic field shielding unit according to an embodiment of the present invention may be manufactured by a manufacturing method described below, but the present invention is not limited thereto.

First, step (a) of preparing a ferrite sheet may be performed. Since the ferrite sheet can be produced by a known method, there is no particular limitation thereto. As an example, a method for producing a Ni-Zn-Cu-Co ferrite is described. A raw material mixture is obtained by mixing nickel oxide, zinc oxide, copper oxide, cobalt oxide and iron trioxide so as to have a predetermined composition ratio. At this time, the mixture can be mixed by dry mixing or wet mixing, and the particle diameter of the raw material to be mixed is preferably 0.05 to 5 mu m. The components such as nickel oxide and zinc oxide contained in the raw material mixture may be in the form of a composite oxide containing itself or the above components, and in the case of cobalt oxide may also be included in the raw material in the form of cobalt ferrite and cobalt tetraoxide.

Next, the raw material mixture is calcined to obtain a calcining material. The calcination is carried out in order to promote the thermal decomposition of the raw material, the homogenization of the components, the generation of ferrite, the disappearance of ultrafine powder by sintering, and the grain growth to an appropriate particle size so as to convert the raw material mixture into a form suitable for post processing. The calcination is preferably carried out at a temperature of 800 to 1100 for about 1 to 3 hours. The preliminary firing may be performed in an air atmosphere or an atmosphere having a higher oxygen partial pressure than the atmosphere.

Next, the calcination material obtained is pulverized to obtain a pulverized material. The pulverization is carried out in order to collapse the aggregation of the firing material to obtain a powder having an appropriate degree of sintering property. When the firing material forms a large lump, it may be pulverized by a wet milling method using a ball mill, an attritor or the like. The wet pulverization can be carried out until the average particle diameter of the pulverized material is preferably about 0.5 to 2 mu m.

Thereafter, the ferrite sheet can be produced through the obtained pulverizing material. A known method can be used for producing the ferrite sheet, and thus the ferrite sheet is not particularly limited in the present invention. As a non-limiting example, the obtained pulverizing material is slurried together with additives such as a solvent, a binder, a dispersant, and a plasticizer to prepare a paste. Using this paste, a ferrite sheet having a thickness of 50 to 350 mu m can be formed. After the sheet is processed into a predetermined shape, a binder removal process and a firing process are performed to produce a ferrite sheet. The firing may be performed at a temperature of 900 to 1300 for about 1 to 5 hours. The atmosphere may be an atmospheric atmosphere or an atmosphere having a higher oxygen partial pressure than that of the atmosphere.

As another embodiment for producing the ferrite sheet, the ferrite powder and the binder resin may be mixed and then manufactured by a known method such as a powder compression molding method, an injection molding method, a calendar method, or an extrusion method.

Next, the produced ferrite sheet may be crushed to form a magnetic shielding layer (b) formed of ferrite fragments.

One embodiment of the step (b) includes the steps of attaching a protective member 140 having a second adhesive layer 140b formed on one surface of a ferrite sheet and an adhesive member 130 having a first adhesive layer 130b formed on the other surface thereof, The ferrite sheet can be sliced into amorphous fragments by applying a pressure to the laminate. By controlling the grain size and the degree of deformation of the desired fragments by applying pressure to the laminate, additional fragments Damage, fracture, and fine fragmentation can be prevented. In the case of the crushing apparatus as shown in FIG. 5, the method for controlling the particle size and the degree of deformation of the crushed pieces can be manufactured by appropriately adjusting the intervals of the crests and valleys, the shape of the crests and valleys, and the like in the crushing apparatus. The method of applying pressure to the laminate may be performed in such a manner that pressure is applied to the laminate together with the crushing in the crusher.

Specifically, as shown in FIG. 5, a plurality of first rollers 11 and 12 having projections and depressions 11a and 12a and second rollers 21 and 22 corresponding to the first rollers 11 and 12, respectively, The laminate 100a is passed through the laminate 100a to the crushing apparatus having the third roller 13 and the fourth roller 23 corresponding to the third roller 13, The magnetic pole shielding unit 100 can be manufactured by further crushing the magnetic pole shield 100b.

6, a support plate 30 having a plurality of metal balls 31 mounted on one surface thereof and rollers 41 and 42 positioned above the support plate 30 for moving the object to be crushed A laminate 100a including a ferrite sheet may be inserted into a crushing apparatus provided therein, and the sheet may be crushed by applying pressure through the metal ball 31. [ The shape of the ball 31 may be spherical, but is not limited thereto. The shape of the ball 31 may be triangular, polygonal, ellipse, or the like. The shape of the ball provided in the single first roller may be one shape, .

As shown in Fig. 7, the magnetic shielding layer is provided in the magnetic shielding unit 100 "as a plurality of magnetic shielding layers 110A, 110B and 110C, and between the adjacent magnetic shielding layers 110A / 110B and 110B / The second adhesive members 131 and 132 may be interposed.

It may be difficult to achieve an enhanced radio power transmission efficiency above a desired level when only a single magnetic shielding layer is provided according to the specific case in which the magnetic shielding unit is applied. That is, a method of increasing the magnetic property of the magnetic shielding unit itself includes a method of selecting a magnetic body having excellent physical properties such as magnetic permeability in a frequency band including a desired frequency of several tens kHz to 6.78 MHz, However, when the thickness of the ferrite sheet of the single layer is increased to more than a certain level in order to increase the thickness of the magnetic shielding layer, the surface portion and the inside of the sheet are not uniformly and uniformly fired in the firing process, The improvement of the magnetic permeability may be insignificant because the structure may be different, so that the increase of the magnetic permeability through the increase of the thickness of the magnetic shielding layer of the single layer is limited. Accordingly, it is possible to achieve a high permeability increasing effect by increasing the overall thickness of the shielding layer in the shielding unit by providing a plurality of the magnetic shielding layers themselves, and the magnetic shielding unit having the laminated magnetic shielding layer has a structure The characteristics can be further improved and the wireless power transmission efficiency can be remarkably improved.

When a plurality of magnetic shielding layers are provided in the magnetic shielding unit, 2 to 12 magnetic shielding layers may be provided, but the present invention is not limited thereto.

When the plurality of magnetic shielding layers 110A, 110B and 110C are provided, the second adhesive members 131 and 132 may bond the magnetic shielding layers between adjacent magnetic shielding layers 110A / 110B and 110B / A buffering function for preventing the additional microfragmentation of debris, and a function for preventing oxidation of ferrite fragments due to penetration of moisture. The second adhesive members 131 and 132 may be the same as the first adhesive member described above. That is, the adhesive composition is a double-sided adhesive member coated with an adhesive composition on both sides of the supporting substrate, or the adhesive composition is applied to one magnetic-field-shielding layer without a supporting substrate for thinning of the shielding unit and another magnetic- It is possible.

In another embodiment, the second adhesive members 131 and 132 may include a heat dissipation adhesive layer for improving the heat dissipation property. The heat dissipation adhesive layer may be formed of an adhesive material such as nickel, silver, carbon And the like, and the specific composition and content may be in accordance with a known composition and content, and therefore, the present invention is not particularly limited thereto.

When a plurality of the magnetic shielding layers 110A, 110B, and 110C are provided, the compositions of the ferrite included in the respective magnetic shielding layers may be the same or different. Also, even if the composition is the same, the magnetic permeability of the respective magnetic shielding layers may be different from each other due to differences in firing conditions and the like. The thickness of each of the magnetic shielding layers may be the same or different depending on the purpose.

Meanwhile, the magnetic field shielding units 100 and 100 'for wireless power transmission according to the above-described embodiments of the present invention include at least one functional layer (not shown) for shielding and / or radiating electromagnetic waves on at least one surface thereof The magnetic field shielding unit having the function layer prevents a frequency fluctuation range of the antenna, which is combined due to electromagnetic waves such as power supply noise, from significantly increasing, thereby reducing the defect rate of the antenna, The heat dissipation is easy to be prevented, the durability of parts due to heat generation, the deterioration of function, and the discomfort due to heat transfer to the user can be prevented.

Further, if the function layer (not shown) provided on the upper and / or lower portions of the magnetic-field shielding units 100 and 100 'has a heat-dissipating function, the thermal conductivity can be improved in the horizontal direction of the magnetic-

(Not shown) in which an electromagnetic wave shielding layer, a heat dissipation layer (not shown), and / or a stacked layer of these are formed on the upper portion of the protective member 130 of the magnetic field shielding unit 100 and / A functional layer such as a composite layer in which these layers are combined as a single layer can be provided. For example, a metal foil, such as copper or aluminum, having excellent thermal conductivity and electrical conductivity can be attached to the upper portion of the protection members 130 and 1300 through an adhesive or double-sided tape. Or a combination of these metals is formed on the protective members 130 and 1300 by a known method such as sputtering, vacuum deposition, chemical vapor deposition, or the like on the protective members 130 and 1300. The protective members 130 and 1300 may be made of a metal such as Cu, Ni, Ag, Al, Au, Sn, Zn, Mn, Mg, Cr, To form a metal thin film. When the functional layer is provided through an adhesive, the adhesive may be a known adhesive. For example, an acrylic, urethane, or epoxy adhesive may be used. On the other hand, heat dissipation performance can be imparted to the adhesive. For this purpose, a known filler such as nickel, silver or carbon material can be mixed with the adhesive, and the content of the filler may be the content of the filler in the known heat- It is not particularly limited in the present invention.

The thickness of the functional layer may be 5 to 100 mu m, and more preferably 10 to 20 mu m to reduce the thickness of the magnetic shielding unit.

In addition, the magnetic field shielding unit 1000 for wireless power transmission according to an embodiment of the present invention includes an antenna (not shown) including antennas 1520 and 1530 for wireless power transmission formed on a circuit board 1510 as shown in FIG. Unit 1500 and is implemented as a wireless power transmission module.

In addition, the antenna for wireless power transmission included in the embodiment of the present invention may be a self-resonant wireless power transmission antenna 1520 having a frequency band including a frequency of 6.78 MHz as an operating frequency, And an antenna 1530 for a wireless power transmission of a magnetic induction type in which a frequency band including a frequency is used as an operating frequency. The antenna 1520 for the self-resonant mode wireless power transmission may be an A4WP type antenna operating in a self-resonant manner in a frequency band of 6.765 to 6.795 MHz. In addition, the antenna 1530 for the magnetic induction type wireless power transmission having the frequency band including the frequency of 100 kHz as the operating frequency has Qi operating in a self-induction manner in a frequency band with an operating frequency of 100 to 350 kHz and / PMA type antenna.

8, the antenna unit 1500 included in the embodiment of the present invention may include at least one of an antenna 1540 for a magnetic security transmission (MST) and an antenna 1550 for a short distance communication (NFC) As shown in FIG. The MST antenna 1540 and / or the NFC antenna 1550 may be positioned between the antenna 1520 for self-resonant system and the antenna 1530 for magnetic power transmission. However, the specific arrangement of the respective antennas can be changed according to the purpose and is not limited thereto.

The antennas 1520 to 1550 that may be provided in the antenna unit 1500 may be antenna coils wound so that the coil has a constant inner diameter and / or may be an antenna pattern on which an antenna pattern is printed , The specific shape, structure, size, material, etc. of the antenna are not particularly limited in the present invention.

9, the present invention includes a radio power transmission antenna 1521 having a frequency band including a frequency of 6.78 MHz formed on a circuit board 1511 as an operating frequency, and a frequency of 13.78 MHz And an antenna unit 1501 having a combo antenna including a short-range communication antenna 1551 having a frequency band of a predetermined frequency band as an operating frequency, and an antenna unit 1501 disposed on one side of the antenna unit 1501, A magnetic field shielding unit 1001, and the module can be expressed by a combination of a wireless power transmission and a local data communication function.

In addition, the wireless power transmission module according to an embodiment of the present invention may be provided in a portable device as a receiving module, and wireless power transmission efficiency and charging distance of the portable device can be remarkably improved.

The present invention will now be described more specifically with reference to the following examples. However, the following examples should not be construed as limiting the scope of the present invention, and should be construed to facilitate understanding of the present invention.

First, to investigate the magnetic properties of nickel (Ni) -Zn (Zn) -couple (Cu) ferrite, bulk ferrite was prepared as follows.

<Preparation Example 1>

A ferrite powder having an average particle diameter of 0.75㎛ (Fe ₂ O ₃ 10 parts by weight of polyvinyl alcohol with respect to 100 parts by weight of polyvinyl alcohol, 48.75% by mole of NiO, 11.7% by mole of NiO, 28.1% by mole of ZnO, 11.2% by mole of CuO and 0.25% by mole of Co ₃ O ₄ ) Dissolved and dispersed. Thereafter, the mixture was charged into a mold having cylindrical holes each having a diameter of 0.5 mm and a height of 0.5 mm, and the mixture was pressure-molded to produce granules. The granules thus prepared were molded into a mold having a final molding density of 3.2 g / cm ^{3, an} outer diameter of 18 mm, an inner diameter of 13 mm, and a thickness of 3.7 mm, followed by degreasing at 500 to 10 hours, and calcining at 940 for 2.2 hours And cooled to produce bulk ferrite.

<Preparation Examples 2 to 5>

The ferrite powder was prepared in the same manner as in Preparation Example 1 except that the composition / composition ratio of the ferrite powder was changed as shown in Table 1 to prepare bulk ferrite as shown in Table 1 below.

<Experimental Example>

Table 1 shows the real part and the imaginary part of the complex permeability by measuring the permeability at 100 kHz and 6.78 MHz for donut-shaped samples prepared according to the preparation examples.

Specifically, the permeability was measured with an impedance analyzer (4294A Precision Impedance Analyzer and 42942A Terminal adapter kit), and the test fixture was measured with a 16454A magnetic material test fixture at an Osc level of 500 mV.

Preparation Example 1 Preparation Example 2 Preparation Example 3 Preparation Example 4 Preparation Example 5 Ferrite composition Fe ₂ O ₃ 48.75 49.60 49.60 48.75 48.75 NiO 11.70 11.77 11.70 11.70 11.77 ZnO 28.10 28.30 28.32 28.13 28.12 CuO 11.20 10.00 10.00 10.35 11.2 Co ₃ O ₄ 0.25 0.33 0.38 0.22 0.18 synthesis 100 100 100 100 100 Bulk ferrite Investment ratio
(6.78MHz) Real part 290 330 380 275 216 Imaginary part 7.4 9 28 6.8 5.9 Investment ratio
(100 kHz) Real part 262 294 235 163 145 Imaginary part 1.4 1.7 2.1 1.2 5.5

As can be seen from Table 1,

In the case of Ni-Zn-Cu ferrites including cobalt tetrasodium tetraoxide, the physical properties vary depending on the content of cobalt tetraoxide. In the case of Preparation Examples 1, 2 and 4, which are included within the preferred range of cobalt tetraoxide according to the present invention It can be confirmed that the physical properties at 6.78 MHz are superior to those of Preparative Examples 3 and 5, which were not.

In addition, it can be confirmed that Preparative Example 2, which satisfies a more preferable range, is superior in physical properties to Preparative Examples 1 and 4.

<Examples>

A ferrite powder having an average particle diameter of 0.75㎛ (Fe ₂ O ₃ 5 parts by weight of a polyvinyl butyral resin with respect to 100 parts by weight of a polyvinyl butyral resin (48.75 mol%, 11.7 mol% of NiO, 28.1 mol% of ZnO, 11.2 mol% of CuO and 0.25 mol% of Co ₃ O ₄ ) Were mixed in a ball mill, dissolved, and dispersed. Thereafter, the ferrite mixture was formed into a sheet shape by a conventional tape casting method, followed by degreasing at 500 for 10 hours and calcining and cooling at 940 for 2.2 hours to prepare a ferrite sheet having a final thickness of 80 탆.

Thereafter, a double-sided tape (support base PET, KYWON CORP., VT-8210C) having a thickness of 10 mu m and having a release film adhered to one surface of the ferrite sheet was attached. PET protective (International Latex, KJ-0714) was attached, and then passed through a crusher as shown in Fig. 5 to produce a magnetic shielding unit.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

100, 100 ', 1000, 1001: magnetic field shielding unit for wireless power transmission
110, 110 ': magnetic field shield layer
130: first adhesive member 140: protective member
1500, 1501: antenna unit 1510, 1511: circuit board
1520, 1521: Self-resonant antenna for wireless power transmission
1530, 1531: Antenna for magnetic induction wireless power transmission
1540: Antenna for MST 1550, 1551: Antenna for NFC

Claims (14)

And a magnetic shielding layer formed of nickel-zinc (Zn) -couple (Cu) ferrite fragments that have been crushed to improve the flexibility of the shielding unit, wherein the nickel- The copper (Cu) ferrite has a real part μ 'of the complex permeability at a frequency of 6.78 MHz satisfies 170 or more. 2. The apparatus of claim 1, wherein the magnetic shielding unit
Shielding layer, and a first adhesive member disposed on the other surface of the magnetic-shielding layer. The method according to claim 1,
Wherein the nickel-zinc (Zn) -copper (Cu) ferrite has a quality index value of 45 or more at a frequency of 6.78 MHz according to Equation (1).
[Equation 1]

The method according to claim 1,
Wherein some of the fragments of the ferrite have a curved shape, at least one of which is not a straight line, and wherein the fraction is at least 45% of the total number of ferrite fragments. The method according to claim 1,
Wherein the magnetic shielding layer has a thickness of 30 to 600 mu m. The method according to claim 1,
Wherein the average particle size of the single piece of ferrite fragments is 100 to 2000 占 퐉. The method according to claim 1,
Wherein the ferrite comprises 8 to 15 mol% of nickel oxide (NiO), 25 to 35 mol% of zinc oxide (ZnO) and 8 to 13 mol% of copper oxide (CuO). 8. The method of claim 7,
Wherein the ferrite further comprises 0.2 to 0.35 mol% of cobalt tetraoxide (Co ₃ O ₄ ). The method according to claim 1,
Wherein the magnetic shielding layers are stacked in a plurality of layers, and a second adhesive member is interposed between adjacent magnetic shielding layers of the plurality of magnetic shielding layers. The method according to claim 1,
Wherein the ferrite fragments include 30% or more fragments having a degree of variability of 8.0 or less according to the following formula (2).
&Quot; (2) &quot;

An antenna unit including an antenna for wireless power transmission; And
And a magnetic field shielding unit for wireless power transmission according to claim 1 arranged on one side of the antenna unit to improve antenna characteristics for wireless power transmission and to focus a magnetic field toward the antenna. An antenna unit including a wireless power transmission antenna having a frequency band including a frequency of 6.78 MHz as an operating frequency and a short-range communication antenna having a frequency band including a frequency of 13.78 MHz as an operating frequency; And
And a magnetic field shielding unit disposed on one surface of the antenna unit to improve the characteristics of the antenna for short-range communication and the antenna for wireless power transmission and to focus the magnetic field toward each antenna. An electronic device comprising a wireless power transmission module according to claim 11 or 12. A portable device comprising the wireless power transmission module according to claim 11 or 12 as a receiving module.

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