KR20170010734A - Shielding unit for wireless charging - Google Patents

Abstract

Provided is a shield unit for wireless charging. The shield unit for wireless charging according to an embodiment of the present invention comprises: a magnetic shield sheet; and a metal protection film which consists of a metal thin film to perform a protection function to protect the magnetic shield sheet, and a heating function to emit heat to the outside, and is arranged on one side of the magnetic shield sheet. The metal protection film has at least one slit having a certain length in a place corresponding to an antenna for wireless charging which is arranged on one side of the magnetic shield sheet. The slit is formed in a direction perpendicular to the lengthwise direction of a pattern constituting the antenna for wireless charging or is formed in a direction perpendicular to a tangent line of the pattern constituting the antenna for wireless charging.

Description

[0001] Shielding unit for wireless charging [

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic shielding, and more particularly, to a shielding unit for wireless charging that shields a magnetic field generated during wireless charging to prevent external leakage and converges in a desired direction.

Recently, various functions such as RFID (Radio Frequency Identification), short range wireless communication (NFC), wireless charging (WPT) and interactive pen tablet have been added to portable terminals including mobile phones and tablet PCs.

NFC is a non-contact type short-range wireless communication module that uses 13.56MHz frequency band as one of RFID tags, and it is a technology to transmit data between terminals at a distance of 10cm. NFC is widely used not only for mobile payments, but also for transferring travel information, transportation, and access control locks for goods information and visitors in supermarkets and general shops, as well as for file transfer.

In addition, recently announced by Google, 'Android Beam' included in the smart phone is a near-field wireless communication (NFC) -based short distance information transmission and reception function that not only allows mobile payment, but also photos, business cards, files, maps, To other phones.

Meanwhile, the portable terminal has a wireless charging function for wirelessly charging a built-in battery. The wireless charging includes a wireless power receiving module built in the portable terminal, a wireless power transmitting module for supplying power to the wireless power receiving module, Module.

The wireless power transmission module and the wireless power reception module may include an antenna unit for transmitting or receiving a wireless signal and a shielding sheet for shielding a magnetic field generated by the antenna unit to prevent leakage, Respectively.

A magnetic member is usually used as the shielding sheet, and a fluororesin-based protective film such as PET is attached to the magnetic member so that the shielding sheet is not exposed to the outside.

However, the conventional protective film as described above can not smoothly function as a protective film because the strength of the material itself is so weak that the film is torn or easily scratched by an external impact.

On the other hand, electronic devices such as mobile phones have become thinner and smaller in size, and accordingly, the parts incorporated in electronic devices have to be made thinner and smaller. In the case of a wireless power receiving module embedded in a mobile phone, the overall thickness is about 0.3T, and it will become thinner in the future.

In order to satisfy the characteristics required for such a very thin thickness, research and development have been progressing in various angles. As a part of this function, it is possible to support the functions of adjacent parts in cooperation with other adjacent parts through multifunctionality of the parts constituting the wireless power receiving module, that is, by changing the material or shape of the parts having only one unique function It is required to maintain the same thickness as the conventional product or to improve the characteristics while having a thinner thickness.

KR 10-2014-0147518 A

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a shielding sheet which can prevent a protective film attached to an exposed surface from being easily damaged by an external impact, Which is capable of increasing the protection function of the wireless rechargeable battery.

In addition, the present invention can be applied to a shielding sheet for wireless communication that can improve the heat dissipation efficiency of the wireless power transmission / reception module by adding a heat shielding function in addition to the protective function by replacing the protective film attached to one surface of the shielding sheet with a metal thin- There are other purposes for providing units.

In order to solve the above problems, the present invention provides a magnetic shield sheet, And a metal protective film made of a metal thin film and disposed on one surface of the magnetic shielding sheet so as to perform a heat dissipating function for discharging heat to the outside together with a protecting function for protecting the magnetic shielding sheet, The film is formed with at least one slit having a predetermined length in a region corresponding to a wireless charging antenna disposed on one side of the magnetic shielding sheet, and the slit is perpendicular to the longitudinal direction of the pattern constituting the wireless charging antenna Wherein the shielding unit is formed in one direction or in a direction perpendicular to a tangent of a pattern constituting the wireless rechargeable antenna.

In one embodiment of the present invention, the metal protective film may be formed of a metal thin film having a thermal conductivity of 200 W / m · K or more, more specifically, an aluminum foil or a copper foil.

At this time, the metal protective film may be directly attached to one surface of the magnetic shield sheet through an adhesive layer having thermal conductivity.

The metal protective film may have a thickness of 1/9 to 1/3 of the thickness of the magnetic shielding sheet.

The metal protective film may include a base material layer made of a metal material and a coating layer that is spin-coated on at least one surface of the base material layer. At this time, the coating layer may include at least one selected from ceramics and metal oxides.

In addition, the magnetic shield sheet may include any one of a ribbon sheet, a polymer sheet, and a ferrite sheet of an amorphous alloy or a nano-crystal alloy. At this time, the ferrite may be any one of Mn-Zn ferrite and Ni-Zn ferrite.

The magnetic shielding sheet may be formed by stacking a plurality of amorphous alloy ribbon sheets or nanocrystalline alloy ribbon sheets.

In addition, the magnetic shielding sheet may be separately formed into a plurality of fine pieces, and the plurality of fine pieces may be entirely insulated or partially insulated between neighboring fine pieces, 3 mm.

In addition, the plurality of micro pieces may be irregular.

In addition, the magnetic shielding sheet may be composed of a first sheet and a second sheet having different characteristics in a predetermined frequency band.

According to the present invention, the protective film attached to one surface of the magnetic shielding sheet is replaced with a metal material, thereby increasing the rigidity of the material itself, thereby preventing damage to the shielding sheet.

In addition, the present invention can be applied to a magnetic shielding sheet having a protective film attached to one surface of a magnetic shielding sheet by replacing a metal protective film made of a metal having thermal conductivity to provide a heat- Thinning can be realized by reducing the thickness.

In addition, the slit-like structure for suppressing eddy current loss can be applied to the metal protective film and the coating layer for improving the emissivity can be applied to improve the heat radiation efficiency and the wireless charging efficiency.

1 is a perspective view of a shielding unit for wireless charging according to an embodiment of the present invention;
Fig. 2 is a sectional view of Fig. 1,
FIG. 3 is a schematic view showing a disposition relationship between a slit and a wireless charging antenna when a slit is formed in a metal protective film applied to a wireless charging shielding unit according to an embodiment of the present invention, wherein a) B) shows a case in which the wireless charging antenna is provided in a circular shape, Fig.
4 is a view showing various forms of slits formed on a metal protective film applied to a shielding unit for wireless charging according to an embodiment of the present invention,
FIG. 5 is a metal protective film applied to a shielding unit for wireless charging according to an embodiment of the present invention, in which a coating layer is formed on at least one surface of a metal protective film,
FIG. 6 is a view showing a shielding sheet applied to a shielding unit for wireless charging according to an embodiment of the present invention, in which a ribbon sheet of an amorphous alloy or a nano-crystal alloy is laminated,
FIG. 7 is a graph showing the relation between the first sheet and the second sheet when the shielding sheet applied to the wireless charging shielding unit according to the embodiment of the present invention is composed of a first sheet and a second sheet having different characteristics A) shows a case where the first sheet is laminated on one side of the second sheet, b) a case where the first sheet having the same thickness as the second sheet is accommodated inside the second sheet, and c) Is a view showing a case where a first sheet having a thickness thinner than that of the second sheet is accommodated in the interior of the second sheet,
FIG. 8 is a schematic view of a wireless power charging module to which a wireless charging shielding unit according to an embodiment of the present invention is applied,
Fig. 9 is a sectional view of Fig. 8. Fig.

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.

The shielding unit 100 according to an embodiment of the present invention includes a magnetic shielding sheet 110 and a metal protective film 120, as shown in FIGS. 1 and 2.

The magnetic shielding sheet 110 shields the magnetic field generated when the antenna unit 10 transmits or receives a radio signal in a predetermined frequency band to increase the magnetic field collection speed, .

Here, the antenna unit 10 may include at least one antenna for transmitting or receiving a radio signal in a predetermined frequency band, and may include a plurality of antennas 12, 13, and 14 that perform different roles .

For example, the plurality of antennas 12, 13, and 14 may include at least one of a wireless charging antenna 12, an MST antenna 13, and an NFC antenna 14 operating in different frequency bands (See Figs. 3A, 3B and 7). In addition, the plurality of antennas 12, 13, and 14 may be formed of a circular coil, an oval coil, or a quadrangular flat coil wound in a clockwise or counterclockwise direction, or a synthetic resin such as polyimide (PI) A conductor such as a copper foil may be patterned in a loop shape on at least one side of the circuit board 11 or may be formed of a loop-shaped metal pattern using conductive ink.

The magnetic shielding sheet 110 is made of a magnetic material so as to shield the magnetic field generated from the antenna unit 10.

For example, the magnetic shielding sheet 110 may be formed of a ribbon sheet of an amorphous alloy or a nanocrystalline alloy, a ferrite sheet or a polymer sheet.

At this time, the ferrite sheet may be a sintered ferrite sheet, and Ni-Zn ferrite or Mn-Zn ferrite may be used. In addition, the amorphous alloy or the nanocrystalline alloy may be an Fe-based or a Co-based magnetic alloy.

6, the magnetic shield sheet 110 'may include a plurality of amorphous alloy or nanocrystalline alloy ribbon sheets 111a, 111b and 111c stacked in layers.

In addition, the magnetic shielding sheet 110 may be divided into a plurality of fine pieces so as to suppress the generation of eddy current by increasing the resistance, and the plurality of fine pieces may be entirely insulated or partially insulated Respectively.

At this time, the plurality of fine pieces may be formed to have a size of 1 to 3 mm, and each piece may be irregularly randomized.

When the magnetic shielding sheet 110 is formed by laminating a plurality of sheets formed by separating into fine pieces, an adhesive layer made of a nonconductive material is disposed between each of the sheets to be seamed between the pair of sheets laminated to each other So that the adhesive layer may serve to insulate a plurality of microparts constituting each sheet. Here, the adhesive layer may be formed of an adhesive or may be provided on one side or both sides of a substrate in the form of a film with an adhesive applied thereto.

The metal protective film 120 is attached to the magnetic shielding sheet 110 through an adhesive layer 130 on one side of the magnetic shielding sheet 110, Is disposed on the opposite surface of the antenna unit 10, that is, on the exposed surface of the magnetic shielding sheet 110 exposed to the outside.

At this time, the metal protective film 120 performs a function of protecting the magnetic shielding sheet 110, and also functions as an auxiliary heat dissipating sheet for discharging the heat generated from the heat source to the outside.

For this, the metal protective film 120 is made of a metal material having thermal conductivity, so that the heat transferred from the heat source is discharged to the outside, so that even if a heat dissipating member such as graphite is not used, .

At this time, the metal protective film 120 may be formed to have a small thickness so as not to increase the overall thickness of the shielding unit 100, and may have a relatively thin thickness compared to the magnetic shielding sheet 110 . Preferably, the metal protective film 120 may have a thickness of 1/9 to 1/3 of the thickness of the magnetic shielding sheet 110.

That is, the metal protective film 120 is provided to have a thickness substantially equal to that of a conventional protective film attached to at least one surface of the magnetic shielding sheet 110 to protect the magnetic shielding sheet 110, 110 so as to replace the conventional protective film used for simply protecting the magnetic shielding sheet 110.

Accordingly, unlike a conventional protective film that protects the magnetic shielding sheet 110 from the external environment, the metal shielding film 120 protects the magnetic shielding sheet 110, The heat dissipation function is performed simultaneously.

Here, the metal material constituting the metal protective film 120 may be in the form of copper, aluminum or a combination thereof having excellent thermal conductivity, or may be in the form of an alloy containing at least one of copper and aluminum, The film 120 may be provided to have a thickness of 1/9 to 1/3 of the thickness of the magnetic shielding sheet 110.

For example, the metal protection film 120 may be formed of a metal thin film having a thermal conductivity of 200 W / m · K or more, and may be provided in the form of an aluminum foil or a copper foil. And may have a thickness of 1/9 to 1/3 with respect to the thickness.

This is because the metal protective film 120 made of a metal is provided so as to have a thickness equal to or less than that of the conventional protective film to replace the conventional protective film, So that a function can be added.

Accordingly, the shielding unit 100 for wireless charging according to the present invention is a shielding unit for a wireless charging system, in which the metal protective film 120 is made of a metal material having a small thickness and attached to one surface of the magnetic shielding sheet 110, A heat radiation function can be added to the protective function while having the same thickness or less than the thickness of the protective film.

This makes it possible to simultaneously perform the protection function and the heat radiation function through the metal protective film 120 without increasing the overall thickness of the wireless charging shield unit 100. Therefore, The shielding function for shielding the magnetic field and the heat radiation function for heat radiation can be performed simultaneously.

In addition, since the metal protection film 120 is made of a metal material, the rigidity of the material itself is increased, so that rigidity is greatly increased as compared with a conventional protection film made of a material such as PET. Accordingly, the magnetic shield sheet 110 is stably protected from external impacts through a metal material having a high rigidity of the material itself, unlike the conventional protective film which is easily damaged by external impact or scratches, It is possible to prevent the deformation of the sheet 110 due to cracks and cracks, thereby minimizing the change in characteristics.

For example, when the wireless charging shielding unit 100 according to the present invention is applied to a wireless charging module including the antenna unit 10 and the shielding unit 100 as shown in Figs. 8 and 9, It is not necessary to use a separate heat radiating member for radiating the heat generated from the antenna unit 10 to the outside when the wireless power receiving module is applied to a wireless power receiving module with a severe thickness limitation, .

At this time, on the other surface of the magnetic shielding sheet 110 on which the metal protective film 120 is not attached, polyethylene terephthalate (PET), polypropylene (PP), polytetrafluoroethylene And a protective film 140 formed of a fluororesin film containing at least one selected from polytetrafluoroethylene (PTFE).

This is because when the antenna unit 10 is attached to one surface of the wireless charging shielding unit 100 according to the present invention, the protective film 140 is removed, Shielding sheet 110, the antenna unit 10 can be attached to one surface of the magnetic-shielding sheet 110 through the adhesive layer 130 disposed between the magnetic-shielding sheets 110.

On the other hand, the adhesive layer 134 may be made to have thermal conductivity to further enhance the heat radiation effect. Such an adhesive layer 134 may be formed of an adhesive containing a thermally conductive component, or may be in the form of a plate-shaped substrate and an adhesive coated on at least one side of the substrate with a thermally conductive component.

In one example, the adhesive may include a thermosetting or photo-curable adhesive component or may include a pressure sensitive adhesive adhesive component, depending on the mode of bonding selected. The adhesive component may be selected from commonly used acrylic, urethane, epoxy and silicone adhesive components, and may further include a curing agent that is conventionally used for crosslinking the adhesive component. Since the curing agent can be selected in consideration of the specific kind of the selected adhesive component and the bonding method, the present invention is not particularly limited thereto.

The adhesive may further include a thermally conductive component in order to exhibit heat dissipation, and the type of the adhesive is not limited as long as it has thermal conductivity. As a non-limiting example, the thermally conductive component may be a metal, an inorganic compound, an organic compound, or a mixture thereof. Specific examples thereof include aluminum (Al), nickel (Ni), copper (Cu) Metal powders such as zinc (Zn), tungsten (W), iron (Fe), silver (Ag), and gold (Au); Calcium carbonate (CaCO _3), aluminum oxide (Al ₂ O _3), aluminum hydroxide (Al (OH) _3), silicon carbide (SiC); Inorganic powders such as boron nitride (BN) and aluminum nitride (AlN); As the carbon material, at least one selected from graphite, graphene, carbon nanotubes (CNT), and organic powders such as carbon nanofibers (CNF) can be used. The thermally conductive component preferably includes at least one carbon material selected from the group consisting of graphite, graphene, carbon nanotube (CNT), carbon nanofiber (CNF), and the like.

As a preferable example, the adhesive layer may be formed through a heat-radiating adhesive layer-forming composition containing a carbon-based filler and a property-improving component for improving heat dissipation property and adhesion property as an adhesive component, a curing agent and a thermally conductive component, 0.1 to 60% by weight of the adhesive layer-forming composition, and the physical property-enhancing component comprises 0.01 to 20 parts by weight of the physical property-enhancing component with respect to 100 parts by weight of the carbon-based filler and the remaining amount may be an adhesive component and a curing agent. May be included in an amount of 5 to 300 parts by weight based on 100 parts by weight of the adhesive component, but the composition is not limited thereto.

The adhesive component may preferably be an epoxy resin, and as a non-limiting example, glycidyl ether type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, linear fatty acid type (linear An epoxy resin, an aliphatic epoxy resin, a cycloaliphatic epoxy resin, a heterocyclic ring-containing epoxy resin, a substituted epoxy resin, a naphthalene-based epoxy resin, and derivatives thereof.

When the epoxy resin is included as an adhesive component, the curing agent may include at least one of a polyhydric hydroxy compound, an aliphatic amine, an aromatic amine, an acid anhydride, and a latent curing agent. The carbon-based filler may be one selected from the group consisting of a single-walled carbon nanotube, a double-walled carbon nanotube, a multi-walled carbon nanotube, a graphene, a graphene oxide, a graphene nanoplate, a graphite, Or more.

The property enhancing component may include a silane-based compound, and the silane-based compound may include 3- [N-anil-N- (2-aminoethyl)] aminopropyltrimethoxysilane, 3- Aminopropyltrimethoxysilane, 3- (N-anil-N-methacryloyl) aminopropyltrimethoxysilane, 3-glycidyloxypropylmethylethoxysilane, N, N-bis [3- (trimethoxycinnamyl) propyl] methacrylamide, [gamma] -glycidoxytrimethyldimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltri (3, 4-epoxycyclohexyl) ethyltrimethoxysil, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethylmethoxysilane, Methoxysilane, heptadecafluorodecyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyl tri (Trimethylsiloxy) silane, methyltris (dimethylsiloxy) silane, 3-aminopropyltriepoxysilane, 3-mercaptopropyltrimethoxysilane and N- (? -Aminoethyl) -? - aminopropyltrimethoxy Silane, and the like.

Here, the heat radiation adhesive layer-forming composition may further contain a dispersant, a dispersion stabilizer, a leveling agent, a pH adjuster, an ion scavenger, a viscosity adjuster, a thixotropic agent, an antioxidant, a heat stabilizer, a light stabilizer, , A dehydrating agent, a flame retardant, an antistatic agent, a fungicide and a preservative may be added. The various additives described above may be those known in the art and are not particularly limited in the present invention. The heat radiation adhesive layer forming component may further include a solvent, and a conventional solvent may be selected according to the selected adhesive component, so that the present invention does not particularly limit it.

5, a metal protective film 120 'according to the present invention includes a substrate layer 123 made of a metal material for heat dissipation and a coating layer (not shown) coated on at least one surface of the substrate layer 123 124). Here, as the coating layer 124, a metal oxide material including ceramic or carbon black having a nano-sized particle size may be used.

The coating layer 124 enhances the radiation efficiency of the metal protective film 120 'by increasing the emissivity.

Also, the metal protective film 120 may be oxidized by oxidizing the surface of the metal material constituting the metal protective film 120 through blackening treatment. For example, in the case of the metal material with the copper the oxide film may be an oxide, such as CuO and Cu ₂ O.

By this, it is possible to minimize cracking by preventing corrosion and improve adhesion and adhesion according to increase of surface area, and increase the emissivity of the material itself, thereby enhancing the heat radiation property without increasing the overall thickness.

In addition, the oxide layer formed on the surface of the metal layer acts as an insulating layer to increase the overall resistance value, thereby reducing the occurrence of eddy currents during wireless charging, thereby improving the charging efficiency. Here, the blackening treatment may be performed using chemicals, heat treatment, or plasma treatment.

Meanwhile, as shown in FIGS. 1 to 4D, the metal protective film 120 according to the present invention may include at least one slit 122 having a predetermined length to penetrate the metal protective film 120 to increase the resistance of the metal protective film 120 It is possible to suppress the occurrence of eddy currents during the wireless charging, thereby improving the charging efficiency.

When the plurality of slits 122 are provided, the plurality of slits 122 may be arranged in a predetermined pattern so that the plurality of slits 122 are arranged in a predetermined pattern. Or may be arranged in a random form.

At this time, the slits 122 are formed in a region corresponding to the antenna 12 for wireless charging, among the antenna units 10 disposed on one surface of the shielding unit 100, As shown in FIG.

3A, when the wireless charging antenna 12 is formed in a rectangular pattern, the slit 122 is perpendicular to the longitudinal direction of the pattern of the wireless charging antenna 12 So as to have a predetermined length in the direction of the arrow.

3B, when the wireless charging antenna 12 is formed in a circular pattern, the slit 122 may extend in a direction perpendicular to the tangent line of the pattern constituting the wireless charging antenna 12 May be formed to have a predetermined length.

In addition, although not shown, if the wireless charging antenna 12 is provided in a form having both a straight section and a curved section, the slit formed in the straight section may be formed as a part of the wireless charging antenna 12 The slit formed in the curved section is formed to have a predetermined length in a direction perpendicular to the tangent line of the pattern constituting the wireless charging antenna 12 as shown in FIG. Respectively.

The slits 122 may be formed in various shapes as shown in FIGS. 4A to 4D. That is, the slit 122 may be provided in the form of a cutout 122a extending inwardly from the rim of the metal protective film 120 (see FIGS. 4C and 4D) (See Figs. 4A and 4B), and a cutout 122a and a through hole 122b may be provided in combination with each other (see Figs. 4A and 4B) Not shown).

In the case where the magnetic shield sheet is composed of a plurality of antennas 12, 13 and 14 in which the antenna unit 10 plays a different role, And may be provided with different kinds of sheets 211 and 212 so as to increase the characteristics of the sheets.

For example, when the antenna unit 10 includes a wireless charging antenna 12 and an NFC antenna 14 that operate in different frequency bands, the magnetic shielding sheets 210, 210 ', 210 " The first and second sheets 211 and 212 may have different characteristics so as to improve characteristics of the corresponding antenna in the band. Here, the antenna unit 10 includes an antenna for MST 13 ).

More specifically, the first sheet 211 is disposed in a region corresponding to the wireless charging antenna 12 so as to enhance the characteristics of the wireless charging antenna 12, and the second sheet 212 Are respectively disposed in areas corresponding to the NFC antennas 14 so as to enhance the characteristics of the NFC antennas 14. [

Here, the first sheet 211 has an area including the wireless charging antenna 12, and the second sheet 212 has an area including the NFC antenna 14 . In addition, the first sheet 211 may include an area directly above the MST antenna 13 when the MST antenna 13 is provided outside the wireless charging antenna 12, It is clear that there is a possibility.

In this case, the magnetic shielding sheets 210, 210 'and 210' 'may be formed such that the first sheet 211 is laminated on one surface of the second sheet 212 (see FIG. 7A) The first sheet 211 having the same thickness as the first sheet 212 may be inserted into the second sheet 212 (see FIG. 7B) The sheet 211 may be inserted into one surface of the second sheet 212 (see FIG. 7C).

The first sheet 211 and the second sheet 212 may be provided to have different magnetic permeabilities or different saturation magnetic fields in a predetermined frequency band. If the second sheet 212 has the same permeability, the investment loss rate may be set to have a different value.

More specifically, the first sheet 211 may have a relatively high permeability in a frequency band of 100 to 300 kHz, which is a low frequency band, than the second sheet, And the first sheet 211 and the second sheet 212 may have the same permeability as the first sheet 211 and the second sheet 212 in the frequency band of 100 to 300 kHz, The loss rate may be set to have a value that is relatively smaller than the investment loss rate of the second sheet 212. [

For example, the first sheet 211 may be a ribbon sheet of an amorphous alloy or a nanocrystalline alloy, and the second sheet 212 may be a ferrite sheet.

This is because the ribbon sheet of the amorphous alloy or nanocrystalline alloy has a relatively higher magnetic permeability than the ferrite sheet in the frequency band of 100 to 300 kHz and is generated in accordance with the power transmission of the frequency of 100 to 300 kHz transmitted from the electrol- Is induced to the first sheet 211 side having a relatively high magnetic permeability so that the wireless power signal can be received with high efficiency toward the wireless charging antenna 12 disposed on the first sheet 211 side .

In the case where the magnetic shielding sheets 210, 210 ', 210 "are implemented as a wireless power receiving module and permanent magnets are provided in the wireless power transmission module, the magnetic shielding sheets 210, 210', 210" All DC magnetic fields are required to be shielded. However, since the DC magnetic field is larger than the influence of the alternating magnetic field generated by the antenna unit 10 on the magnetic shield sheets 210, 210 ', and 210 ", the magnetic shield sheet is magnetically saturated to deteriorate its performance as a magnetic shield sheet Which causes a problem of drastically lowering the power transmission efficiency.

Therefore, it is necessary to prevent magnetic saturation from being caused by permanent magnets provided in the wireless power transmission module. For this reason, since the ribbon sheet of the amorphous alloy or nano-crystal alloy has a relatively larger saturation magnetic field than the ferrite sheet in the frequency band of 100 to 300 kHz, the first sheet The mobile phone 211 can prevent the magnetization by the permanent magnet in the frequency band of 100 to 300 kHz in which wireless charging is performed, so that the wireless charging can be smoothly performed.

In addition, even though the first sheet 211 and the second sheet 212 have the same permeability in a frequency band of 100 to 300 kHz, the investment loss rate of the first sheet 211 is lower than that of the second sheet 212 The loss of permeability due to the investment loss rate in the wireless charging operation is reduced as a result.

Accordingly, the alternating magnetic field generated according to the power transmission of the frequency of 100 to 300 kHz transmitted from the wireless power transmission module is guided to the first sheet 211 having a relatively high magnetic permeability, So that the wireless power signal can be received at a high efficiency.

Meanwhile, the second sheet 212 may be provided to have a relatively higher permeability than the first sheet at a high frequency of 13.56 MHz, and the first sheet 211 and the second sheet 212 The investment loss rate of the second sheet 212 may be smaller than the investment loss rate of the first sheet 211. In this case,

For example, the first sheet 211 may be a ribbon sheet of an amorphous alloy or a nanocrystalline alloy, and the second sheet 212 may be a ferrite sheet.

This is because the ferrite sheet has a relatively higher permeability than the ribbon sheet of the amorphous alloy or the nano-crystal alloy in the frequency band of 13.56 MHz. Therefore, when the NFC is performed, the 13.56 MHz high- Is induced to the second sheet 212 side having a relatively high magnetic permeability so that the high frequency signal is received with high efficiency toward the NFC antenna 14 disposed in the region corresponding to the second sheet 212 So that it can be induced.

Even if the first sheet 211 and the second sheet 212 have the same magnetic permeability at a frequency of 13.56 MHz, the investment loss rate of the second sheet 212 is lower than the investment loss rate of the first sheet 211 As a result, loss of permeability due to the investment loss rate in the short-range wireless communication (NFC) is reduced. Thus, the AC magnetic field generated by the 13.56 MHz high frequency signal generated by the RF reader is directed toward the second sheet 212 having a relatively high magnetic permeability, whereby the NFC antenna 14 So that the high-frequency signal can be received with high efficiency.

Here, a ribbon sheet of an amorphous alloy or a nano-crystal alloy is used as the first sheet 211, and a ferrite sheet is used as the second sheet 212. However, the present invention is not limited thereto, and the permeability, The materials of the first sheet 211 and the second sheet 212 can be variously changed as long as the loss ratio satisfies the condition relative to each other in the frequency band.

For example, the first sheet 211 and the second sheet 212 may be made of the same material having a different permeability at a frequency of 100 to 300 kHz and / or a frequency of 13.56 MHz, and the first sheet 211 A ferrite sheet may be used, and as the second sheet 212, a ribbon sheet of an amorphous alloy or a nano-crystal alloy may be used. This is because even if they are made of the same material, they can be manufactured to have different characteristics (permeability, saturation magnetic field, investment loss rate, etc.) through various conditions such as heat treatment temperature and lamination number.

In addition, when a ribbon sheet of an amorphous alloy or a nanocrystalline alloy is used as at least one of the first sheet 211 and the second sheet 212, a single-layer ribbon sheet may be used, The first sheet 211 and / or the second sheet 212 may be configured in the form of a laminate of a plurality of amorphous alloy or nano-crystal alloy alloy ribbon sheets.

The wireless charging shielding unit 100, 200, 200 ', 200' 'according to an embodiment of the present invention may be applied to the Qi scheme or may be a PMA scheme in which a part of the magnetic field lines generated from the permanent magnet is guided through an attractor The wireless charging shielding unit 100, 200, 200 ', 200 "according to an embodiment of the present invention may be applied to a self-resonating system in which wireless charging is performed at a frequency of 6.78 MHz. .

As an example, the wireless charging shielding unit 100 according to an embodiment of the present invention includes a wireless power charging module 1 (FIG. 1) including a shielding unit 100 and an antenna unit 10, as shown in FIGS. 8 and 9 ). ≪ / RTI >

The wireless power charging module 1 may be a wireless power transmission module for transmitting a wireless signal to the electronic device or a wireless power receiving module for receiving a wireless signal from the wireless power transmission module.

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.

1: wireless power charging module 10: antenna unit
11: circuit board 12: wireless charging antenna
13: Antenna for MST 14: Antenna for NFC
100, 200, 200 ', 200 ": Shielding unit for wireless charging
110, 110 ', 210, 210', 210 ": magnetic field shielding sheet
111a, 111b, 111c: ribbon sheet of amorphous alloy or nano-crystal alloy
111d: adhesive layer 211: first sheet
212: second sheet 120: metal protective film
122: slit 124: coating layer
130: adhesive layer 140: protective film

Claims (14)

Magnetic shielding sheet; And
And a metal protective film made of a metal thin film and disposed on one surface of the magnetic shield sheet so as to perform a heat dissipating function for discharging heat to the outside together with a protective function for protecting the magnetic shield sheet,
Wherein the metal protective film is formed with at least one slit having a predetermined length in a region corresponding to a wireless charging antenna disposed on one side of the magnetic shielding sheet,
Wherein the slit is formed in a direction perpendicular to a longitudinal direction of a pattern constituting the wireless charging antenna or in a direction perpendicular to a tangent of a pattern constituting the wireless charging antenna. The method according to claim 1,
Wherein the metal protective film is a metal thin film having a thermal conductivity of 200 W / m · K or more and is directly attached to one surface of the magnetic shield sheet through an adhesive layer having thermal conductivity. The method according to claim 1,
Wherein the metal protective film is an aluminum foil or a copper foil. The method according to claim 1,
Wherein the metal protective film has a thickness of 1/9 to 1/3 of the thickness of the magnetic shielding sheet. The method according to claim 1,
Wherein the metal protective film comprises a base material layer made of a metal material and a coating layer radially coated on at least one surface of the base material layer. 6. The method of claim 5,
Wherein the coating layer comprises at least one selected from ceramic or metal oxide. The method according to claim 1,
Wherein the magnetic shielding sheet comprises any one of a ribbon sheet, a polymer sheet and a ferrite sheet of an amorphous alloy or a nano-crystal alloy. 8. The method of claim 7,
Wherein the ferrite is any one of Mn-Zn ferrite and Ni-Zn ferrite. The method according to claim 1,
Wherein the magnetic shielding sheet is formed by laminating a plurality of amorphous alloy ribbon sheets or nano-crystal alloy alloy ribbon sheets. The method according to claim 1,
Wherein the magnetic shielding sheet is divided into a plurality of minute pieces. 11. The method of claim 10,
Wherein the plurality of micro pieces are totally insulated or partially insulated between neighboring micro pieces. 11. The method of claim 10,
Wherein the plurality of micro pieces are of a size of 1 mu m to 3 mm. 11. The method of claim 10,
Wherein the plurality of micro pieces are formed in an irregular shape. The method according to claim 1,
Wherein the magnetic shielding sheet comprises a first sheet and a second sheet having different characteristics in a predetermined frequency band.

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