1
`
`
`DESCRIPTION
`Invention Title: MAGNETIC FIELD SHIELDING SHEET FOR WIRELESS
`CHARGER, METHOD FOR MANUFACTURING SAME, AND RECEIVING
`APPARATUS FOR WIRELESS CHARGER USING THE SHEET
`
`【Technical Field】
`[1]
`
`The present invention relates to a magnetic field shielding sheet for a wireless
`charger, a method for manufacturing the same, and a receiving apparatus for a wireless
`charger using the sheet, and more particularly, to a magnetic field shielding sheet for a
`wireless charger, which prevents an alternating-current magnetic field, which is
`generated when a charger function is implemented in a portable terminal or the like in a
`contactless (wireless) manner, from affecting a main body of a portable terminal or the
`like, thereby improving efficiency of power transmission, a method for manufacturing
`the same, and a receiving apparatus for a wireless charger using the sheet.
`【Background Art】
`[2]
`
` A
`
` charging method for a secondary battery mounted in an electronic device
`such as a portable terminal or a video camera includes two types of charging methods,
`that is, a contact-type charging method and a contactless charging method. The contact-
`type charging method is a method in which charging is performed by directly bringing
`an electrode of a power receiving apparatus into direct contact with an electrode of a
`power feeding apparatus.
`[3]
`The contact-type charging method has been generally used in a wide range of
`
`applications due to its simple apparatus structure. However, as a weight of various
`electronic devices is reduced with the miniaturization and weight reduction of electronic
`devices, a contact pressure between electrodes of the power receiving apparatus and the
`power feeding apparatus is insufficient, causing problems such as charging failure
`(charging error). In addition, since the secondary battery is weak to heat, it is
`necessary to prevent the temperature rising of the battery, and attention has to be paid to
`a circuit design not to cause overdischarge and overcharge. In order to cope with these
`problems, the contactless charging method has recently been studied.
`[4]
`
`The contactless charging method is a charging method using electromagnetic
`induction by installing coils on both sides of a power receiving apparatus and a power
`feeding apparatus.
`[5]
`
`The miniaturization of a contactless charger has been realized by using a ferrite
`core as a magnetic core and winding a coil around the ferrite core. In addition, in
`order to reduce the miniaturization and slimness, technology in which a resin substrate
`is formed by mixing ferrite powder and amorphous powder and a coil or the like is
`mounted on the resin substrate has been proposed. However, when ferrite is processed
`thinly, the magnetic field shielding sheet is brittle and has poor impact resistance, and
`thus there is a problem in that a defect occurs in a power receiving system due to a drop
`or collision of a device.
`[6]
`In addition, in order to reduce a thickness of a power receiving part in response
`
`to the reduction in the thickness of electronic devices, a flat coil formed by printing a
`metal powder paste on the coil has been employed. A structure for strengthening
`coupling using a flat coil and a magnetic sheet has been proposed. In these proposed
`structures, a magnetic material (magnetic sheet) is used as a core material for
`strengthening the coupling between primary and secondary coils.
`[7]
`Meanwhile, when a power transmission speed increases, not only the coupling
`
`between adjacent transformers, but also defects due to heat generation in the
`
`Petitioner Samsung and Google Ex-1016, 0001
`
`

`

`2
`
`
`surrounding parts are likely to occur. That is, when the flat coil is used, a magnetic
`flux passing through the flat coil is connected to a substrate inside the device, and thus,
`heat is generated in the inside of the device due to an eddy current generated by
`electromagnetic induction. As a result, there are problems such as large power may
`not be transmitted and a long charging time is taken.
`[8]
`In order to cope with these problems, a magnetic material (magnetic sheet) has
`
`also been used as a shielding member for a back surface. In order to obtain a sufficient
`shielding effect, the magnetic material (magnetic sheet) has high permeability, and the
`larger the area and thickness, the more effective the shielding effect may be obtained.
`[9]
`It is common to use a magnetic material, such as amorphous ribbon, ferrite, or a
`
`polymer sheet containing magnetic powder, as the magnetic field shielding sheet. A
`magnetic field focusing effect of shielding a magnetic field and improving performance
`of additional functions is good in the order of the amorphous ribbon, the ferrite, and the
`polymer sheet containing magnetic powder with high permeability.
`[10]
`The power receiving apparatus of the conventional contactless charging system
`
`has a magnetic material (magnetic sheet) with high permeability and a large volume,
`which is disposed on a side opposite to a primary coil side, that is, on a side of a
`secondary coil, in order to strengthen the coupling for improvement in power
`transmission efficiency and to improve the shielding performance for suppress of heat
`generation. According to this disposition, a fluctuation in inductance of the primary
`coil becomes large, and there arises a problem that operation conditions of a resonance
`circuit deviate from the resonant conditions that may exert a sufficient effect depending
`on a relative positional relationship between the magnetic material and the primary coil.
`[11]
`To solve the above-described problems, Korean Patent Laid-Open Publication
`
`No. 10-2010-31139 (Patent Document 1) discloses technology in which, by providing a
`power receiving apparatus capable of improving resonance and suppressing heat
`generation, an electronic device and a power receiving system using the power
`receiving apparatus can increase transmission power and shorten a charging time.
`[12]
`That is, Korean Patent Laid-Open Publication No. 10-2010-31139 discloses
`
`technology of, by arranging a composite magnetic material including a plurality of
`magnetic sheets (magnetic ribbons) in at least one location between a spiral coil (spiral
`coil, secondary coil on a power receiving side) and a secondary battery and between a
`rectifier and the spiral coil, preventing a magnetic flux generated from a spiral coil
`(primary coil) on a power feeding side from interlinking with a circuit board, a
`secondary battery, and the like, and controlling the amount of change in inductance of
`the primary coil by presence or absence of the secondary coil while suppressing noise
`and heat generation due to induced electromotive force (electromagnetic induction) to
`effectively control oscillation by improving a resonance of a resonance circuit formed of
`the primary coil.
`[13]
`The composite magnetic material sets a first magnetoresistance of a first
`
`magnetic sheet adjacent to the spiral coil to be less than or equal to 60, a second
`magnetoresistance of a second magnetic sheet laminated on the first magnetic sheet to
`be greater than or equal
`to 100, and values (second magnetoresistance/first
`magnetoresistance) to be greater than or equal to 1.0.
`[14]
`The first magnetic sheet is manufactured by adhering a polycarbonate resin
`
`onto both sides of the first amorphous ribbon using an adhesive layer, respectively, the
`second magnetic sheet is manufactured by adhering the polycarbonate resin onto both
`sides of the second amorphous ribbon with a relatively higher relative permeability
`using the adhesive layer, and then, the first magnetic sheet and the second magnetic
`
`Petitioner Samsung and Google Ex-1016, 0002
`
`

`

`3
`
`
`sheet are integrally adhered through the adhesive layer.
`[15]
`Meanwhile, in the case of the ferrite sheet or the polymer sheet containing
`
`magnetic powder, the permeability is slightly lower than that of the amorphous ribbon.
`In order to improve the performance of such low permeability, it is difficult to respond
`to the trend of thinner terminals because it is thicker than the amorphous ribbon, which
`is a thin plate with a thickness of several tens of m.
`[16]
`In addition, in the case of the amorphous ribbon with high permeability, since
`
`the ribbon itself is a thin metal plate, there is no burden on the thickness, but, when an
`alternating-current magnetic field according to a frequency of 100 kHz used for power
`transmission is applied to the amorphous ribbon, the application function may be
`deteriorated due to the effect of eddy current on the ribbon surface, or deterioration in
`efficiency and heat generation may occur during wireless charging occur.
`[17]
`In the case of Co- or Fe-based amorphous ribbon, a surface resistance may be
`
`slightly increased through heat treatment, but when processing such as flake which
`reduces a ribbon surface area to further reduce the effect of the eddy currents is
`performed, the permeability drops significantly and thus, a function as a shielding sheet
`is significantly reduced.
`[18]
`In addition, in the case of the wireless charger, in order to maximize the
`
`efficiency of the charger, there are many structures employing permanent magnets to
`help align with a receiver in a power transmission transmitter. As a result, due to the
`direct current magnetic field of the permanent magnet, the thin shielding sheet has a
`magnetization (saturation) phenomenon, resulting in poor performance or a sharp drop
`in power transmission efficiency.
`[19]
`Accordingly, in the prior art, in order to exhibit shielding properties without
`
`being affected by the permanent magnets, the thickness of the shielding sheet needs to
`be very thick (0.5 T or more) to maintain high power transmission efficiency, which is a
`major obstacle to slimming of portable terminals.
`【Disclosure】
`【Technical Problem】
`[20]
`Since the voltage induced in the secondary coil of the wireless charger is
`
`determined by Faraday's law and Lenz's law, in order to obtain a high voltage signal, the
`larger the amount of magnetic flux that interlinks with the secondary coil, the more
`advantageous it is. The amount of magnetic flux increases as the amount of soft
`magnetic material included in the secondary coil increases and the permeability of the
`material increases. In particular, since the wireless charging device essentially transmits
`power in a contactless manner, in order to focus a wireless electromagnetic wave
`generated from a primary coil of the transmitting apparatus to the secondary coil of the
`receiving apparatus, the magnetic field shielding sheet on which the secondary coil is
`mounted needs to be made of a magnetic material with high permeability.
`[21]
`The conventional magnetic field shielding sheet for the wireless charger is a
`
`thin film and does not provide a solution to the problem of heat generation due to
`shielding and to increase the wireless charging efficiency. Accordingly, in the case of
`the amorphous ribbon, the present inventor has completed the present invention by
`recognizing that the inductance (permeability) is less reduced even when the ribbon
`becomes flake, and a quality factor Q of the secondary coil increases as the
`magnetoresistance is significantly reduced.
`[22]
`Therefore, the present invention has been proposed to solve the problems of the
`
`prior art, and an object of the present invention provides a magnetic field shielding sheet
`
`Petitioner Samsung and Google Ex-1016, 0003
`
`

`

`4
`
`
`for a wireless charger with excellent power transmission efficiency by significantly
`reducing a loss due to an eddy current by flake treatment of amorphous ribbon to
`increase a quality factor Q of a secondary coil while blocking an effect of a magnetic
`field on a main body and a battery of a portable terminal or the like, a method for
`manufacturing the same, and a receiving apparatus for a wireless charger using the sheet.
`[23]
`Another object of the present invention provides a magnetic field shielding
`
`sheet for a wireless charger capable of preventing moisture penetration by filling a gap
`between fine strands of amorphous ribbon with an adhesive by flake-treating the
`amorphous ribbon and then performing compression bonding lamination treatment on
`the amorphous ribbon, and reducing an eddy current and preventing shielding
`performance from deteriorating by enclosing all sides of the fine strands with the
`adhesive (dielectric) to isolate the fine strands from each other, and a method for
`manufacturing the same.
`[24]
`Another object of the present invention provides a magnetic field shielding
`
`sheet for a wireless charger with high power transmission efficiency even with a small
`number of nanocrystal grain ribbons by setting a shape of a shielding sheet to a shape
`similar to a secondary coil of a receiving apparatus for a wireless charger, and a
`receiving apparatus for a wireless charger using the same.
`[25]
`Another object of the present invention provides a magnetic field shielding
`
`sheet for a wireless charger with high productivity and low manufacturing cost while
`maintaining an original thickness of a sheet by sequentially performing flake and
`lamination treatment in a roll-to-roll method to mold the sheet, and a method for
`manufacturing the same.
`
`【Technical Solution】
`[26]
`To achieve the above object, a magnetic field shielding sheet for a wireless
`
`charger includes: at least one single-layer thin magnetic sheet made of an amorphous
`ribbon separated into multiple fine strands; a protective film adhered onto one side of
`the thin magnetic sheet via a first adhesive layer; and a double-sided tape adhered onto
`the other side of the thin magnetic sheet via a second adhesive layer formed on one side
`of the double-sided tape, in which a gap among the multiple fine strands is filled with
`portions of the first adhesive layer and second adhesive layer such that the multiple fine
`strands are isolated from each other.
`[27]
`According to another aspect of the present invention, a method for
`
`manufacturing a magnetic field shielding sheet for a wireless charger includes: forming
`a laminated sheet by adhering a protective film and a double-sided tape having a release
`film on an exposed surface onto both sides of a thin magnetic sheet formed of at least
`one layer of amorphous ribbon; dividing the thin magnetic sheet into multiple fine
`strands by flake treatment of the laminated sheet; and laminating the flake-treated
`laminated sheet to planarize and slim the laminated sheet and filling the protective film
`and portions of the first and second adhesive layers provided on the double-sided tape in
`a gap between the multiple fine strands to isolate the multiple fine strands from each
`other.
`[28]
`According to still another aspect of the present invention, a receiving apparatus
`
`for a wireless charger that charges a secondary battery in an electromagnetic induction
`method from a transmitting apparatus of the wireless charger includes: a secondary coil
`that receives a radio high-frequency signal transmitted by an electromagnetic induction
`method from the transmitting apparatus; and a magnetic field shielding sheet that is
`disposed between the secondary coil and the secondary battery, and shields a magnetic
`field generated by the radio high-frequency signal and at the same time induces the
`
`Petitioner Samsung and Google Ex-1016, 0004
`
`

`

`5
`
`
`secondary coil to absorb the radio high-frequency signal required to perform the
`wireless charging function, in which the magnetic field shielding sheet includes: at least
`one single-layer thin magnetic sheet formed of an amorphous ribbon separated into
`multiple fine strands; a protective film adhered onto one side of the thin magnetic sheet
`via a first adhesive layer; and a double-sided tape adhered onto the other side of the thin
`magnetic sheet via a second adhesive layer formed on one side of the double-sided tape,
`and a gap among the multiple fine strands is filled with portions of the first adhesive
`layer and second adhesive layer such that the multiple fine strands are isolated from
`each other.
`
`【Advantageous Effects】
`[29]
`As described above, according to the present invention, it is possible to make
`
`power transmission efficiency excellent by significantly reducing a loss due to an eddy
`current by flake treatment of amorphous ribbon to increase a quality factor Q of a
`secondary coil while blocking an effect of a magnetic field on a main body and a battery
`of a portable terminal or the like.
`[30]
`In addition, according to the present invention, it is possible to prevent moisture
`
`penetration by filling a gap between fine strands of amorphous ribbon with an adhesive
`by flake-treating the amorphous ribbon and then performing compression bonding
`lamination treatment on the amorphous ribbon and reduce an eddy current and prevent
`shielding performance from deteriorating by enclosing all surfaces of the fine strands
`with the adhesive (dielectric) to isolate the fine strands from each other. As a result, it
`is possible to prevent changes in appearance and deterioration in characteristics due to
`oxidation of an amorphous ribbon due to moisture penetration by enclosing all sides of
`the fine strand with adhesive (dielectric).
`[31]
`In addition, according to the present invention, it is possible to reduce a
`
`thickness of a sheet to 0.3 mm or less while exhibiting high power transmission
`efficiency or equivalent power transmission efficiency even with a small number of
`nanocrystal grain ribbons by setting a shape of a shielding sheet to a shape similar to
`that of a receiver coil.
`[32]
`In addition, according to the present invention, it is possible to increase
`
`productivity and save manufacturing cost while maintaining an original thickness of a
`sheet by sequentially performing flake and lamination treatment in a roll-to-roll method
`to mold the sheet.
`
`【BRIEF DESCRIPTION OF THE DRAWINGS】
`[33]
`FIG. 1 is an exploded perspective view illustrating a magnetic field shielding
`
`sheet for a wireless charger according to the present invention.
`[34]
`FIG. 2 is a cross-sectional view illustrating an example of using a single sheet
`
`of nanocrystal grain ribbon sheet according to a first embodiment.
`[35]
`FIG. 3 is a cross-sectional view illustrating an example of using six nanocrystal
`
`grain ribbon sheet according to a second embodiment.
`
`Petitioner Samsung and Google Ex-1016, 0005
`
`

`

`6
`
`
`
`[36]
`FIGS. 4 and 5 each are cross-sectional views illustrating structures of a
`
`protective film and a double-sided tape used in the present invention.
`[37]
`FIG. 6 is an exploded perspective view illustrating a magnetic field shielding
`
`sheet for a wireless charger according to a third embodiment of the present invention.
`[38]
`FIG. 7 is a process diagram for describing a process of manufacturing a
`
`magnetic field shielding sheet for a wireless charger according to the present invention.
`[39]
`FIGS. 8 and 9 each are cross-sectional views illustrating a flake process of a
`
`laminated sheet according to the present invention.
`[40]
`FIG. 10 is a cross-sectional view illustrating a state in which the laminated
`
`sheet according to the present invention is flake-treated.
`[41]
`FIGS. 11 and 12 each are cross-sectional views illustrating a lamination process
`
`of the flake-treated laminated sheet according to the present invention.
`[42]
`FIG. 13 is a cross-sectional view illustrating a state in which the magnetic field
`
`shielding sheet for a wireless charger according to the first embodiment of the present
`invention is flake-treated and then laminated.
`[43]
`FIGS. 14A and 14B each are enlarged photos of the magnetic field shielding
`
`sheet that is flake-treated and then is not subjected to the lamination process, and is
`subjected to a humidity test, and enlarged photos of the magnetic field sheet according
`to the present invention is flake-treated and then laminated, and is subjected to the
`humidity test.
`[44]
`FIG. 15 is a cross-sectional view illustrating a thin magnetic sheet used in a
`
`magnetic field shielding sheet for a wireless charger according to a fourth embodiment
`of the present invention.
`[45]
`FIG. 16 is an exploded perspective view illustrating a structure in which the
`
`magnetic field shielding sheet according to the present invention is applied to a
`receiving apparatus for a wireless charger.
`[46]
`FIG. 17 is an exploded perspective view illustrating that the receiving apparatus
`
`for a wireless charger of FIG. 16 is assembled to a battery cover and coupled to a
`portable terminal.
`[47]
`FIG. 18 is a plan view illustrating a dual antenna structure in which an NFC
`
`antenna and an antenna for a wireless charger are formed using an FPCB.
`[48]
`FIG. 19 is a schematic view illustrating a measurement structure for testing
`
`efficiency and temperature characteristics of a shielding sheet according to the present
`invention.
`【Best Mode】
`[49]
`The above-described objects, features, and advantages will become more
`
`obvious from the following description described below in detail with reference to the
`accompanying drawings. Therefore, those skilled in the art to which the present
`disclosure pertains may easily practice a technical idea of the present disclosure.
`[50]
`Further, in describing the present disclosure, in the case in which it is decided
`
`that a detailed description of a well-known technology associated with the present
`
`Petitioner Samsung and Google Ex-1016, 0006
`
`

`

`7
`
`
`disclosure may unnecessarily make the gist of the present disclosure unclear, it will be
`omitted.
`[51]
`FIG. 1 is an exploded perspective view illustrating a magnetic field shielding
`
`sheet for a wireless charger according to the present invention, and FIG. 2 is a cross-
`sectional view illustrating an example of using a single sheet of nanocrystal grain ribbon
`sheet according to a first embodiment.
`[52]
`Referring to FIGS. 1 and 2, a magnetic field shielding sheet for a wireless
`
`charger 10 according to a first preferred embodiment of the present invention includes a
`multi-layer thin magnetic sheet 2 of at least one layer in which a ribbon made of an
`amorphous alloy or a nanocrystal grain alloy is heat-treated and then flake-treated to be
`separated into multiple fine strands 20 and/or is formed with cracks, a protective film 1
`that is adhered onto an upper portion of the thin magnetic sheet 2, a double-sided tape 3
`that is adhered onto a lower portion of the thin magnetic sheet 2, and a release film 4
`that is detachably adhered to a lower portion of the double-sided tape 3.
`[53]
`The thin magnetic sheet 2 may use, for example, a ribbon of a thin plate made
`
`of an amorphous alloy or a nanocrystal grain alloy.
`[54]
`The amorphous alloy may use a Fe-based or Co-based magnetic alloy, and
`
`preferably uses a Fe-based magnetic alloy in consideration of material cost.
`[55]
`As the Fe-based magnetic alloy, for example, a Fe-Si-B alloy may be used, in
`
`which it is preferable that Fe is preferably 70 to 90 atomic%, and the sum of Si and B is
`10 to 30 atomic%. The higher the content of metals including Fe, the higher the
`saturation magnetic flux density is. However, when the content of Fe element is
`excessive, the ribbon is difficult to become amorphous, so the content of Fe is
`preferably 70-90 atomic% in the present invention. In addition, when the sum of Si
`and B is in the range of 10-30 atomic%, the amorphous forming ability of the alloy is
`the best. 20 atomic% or less of corrosion resistant element such as Cr, Co, or the like,
`may be added to such a basic composition in order to prevent corrosion, and a small
`amount of other metal elements may be added to such a basic composition, if necessary,
`in order to give other characteristics.
`[56]
`As the Fe-Si-B alloy, an alloy in which, for example, a crystallization
`
`temperature is 508°C and a Curie temperature (Tc) is 399°C may be used. However,
`the crystallization temperature may vary depending on the content of Si and B or other
`metal elements added in addition to a ternary alloy component and the content thereof.
`[57]
`According to the present invention, as a Fe-based amorphous alloy, if necessary,
`
`a Fe-Si-B-Co-based alloy may be used.
`[58]
`Meanwhile, the thin magnetic sheet 2 may use a thin-plate ribbon made of a Fe-
`
`based nanocrystal grain magnetic alloy.
`[59]
`As the Fe-based nanocrystal grain magnetic alloy, it is preferable to use an
`
`alloy satisfying the following Equation 1.
`[60]
`
`
`[61]
`In the above Equation 1, A denotes at least one element selected from Cu and
`
`Au, D denotes at least one element selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Ni,
`Co, and rare earth elements, E denotes at least one element selected from Mn, Al, Ga,
`Ge, In, Sn, and platinum group elements, Z denotes at least one element selected from C,
`
`[Equation 1]
`Fe100-c-d-e-f-gAcDdEeSifBgZh
`
`Petitioner Samsung and Google Ex-1016, 0007
`
`

`

`8
`
`
`N, and P, c, d, e, f, g, and h are numbers that satisfy relations 0.01  c  8 at%, 0.01  d
` 10 at%, 0  e  10 at%, 10  f  25 at%, 3  g  12 at %, and 15  f + g + h  35 at%,
`respectively, and has a microstructure in which an area ratio of the alloy structure is
`20% or more and a particle diameter is 50 nm or less.
`[62]
`In the above Equation 1, element A is used to improve corrosion resistance of
`
`the alloy, prevent coarsening of crystal grains, and improve magnetic properties such as
`iron loss and permeability of the alloy. When there is too little content of element A, it
`is difficult to acquire an effect of suppressing the coarsening of the crystal grain.
`Conversely, when the content of element A is too large, the magnetic properties
`deteriorate. Accordingly, the content of element A is preferably in the range of 0.01 to
`8 at%. Element D is an element effective for making the crystal grain diameter
`uniform, reducing magnetostriction, and the like. The content of element D is
`preferably in the range of 0.01 to 10 at%.
`[63]
`Element E is an effective element for improving soft magnetic properties and
`
`corrosion resistance of the alloy. The content of element E is preferably 10 at% or less.
`Si and B are elements that make an alloy amorphous during manufacturing a magnetic
`sheet. The content of Si is preferably in the range of 10 to 25 at%, and the content of
`B is preferably in the range of 3 to 12 at%. Moreover, element Z may be included in
`the alloy as an amorphous composition element of alloys other than Si and B. In that
`case, the total content of Si, B, and Z elements is preferably in the range of 15 to 35 at%.
`The microcrystal structure is preferably formed to implement a structure in which
`crystal grains having a grain size of 5 to 30 nm exist in an area ratio of 50 to 90% in the
`alloy structure.
`[64]
`In addition, as the Fe-based nanocrystal grain magnetic alloy used in the thin
`
`magnetic sheet 2, a Fe-Si-B-Cu-Nb alloy may be used. In this case, it is preferable that
`Fe is 73-80 at%, the sum of Si and B is 15 to 26 at%, and the sum of Cu and Nb is 1 to 5
`at%. An amorphous alloy manufactured in the form of a ribbon having such a
`composition range may be easily precipitated as nano-phase crystal grains by heat
`treatment to be described later.
`[65]
`As illustrated in FIG. 4, the protective film 1 may use, for example, a
`
`polyethylene terephthalate (PET) film, a polyimide film, a polyester film, a
`polyphenylene sulfide (PPS) film, a polypropylene (PP) film, a polyterephthalate
`(PTFE) film, and a resin-based film 11 such as a fluororesin-based film, and is adhered
`onto one side of the thin magnetic sheet 2 via the first adhesive layer 12.
`[66]
`In addition, the protective film 1 may have a thickness in the range of 1 to 100
`
`m, preferably 10 to 30 m, and more preferably 20 m.
`[67]
`When the protective film 1 used in the present invention is adhered to one side
`
`of the amorphous ribbon sheet 2, the release film 4a adhered to the other side of the first
`adhesive layer 12 to protect the first adhesive layer 12 is removed and adhered.
`[68]
`In addition, as illustrated in FIG. 5, the double-sided tape 3 is used as a
`
`substrate 32 formed of the fluororesin-based film such as the polyethylene terephthalate
`(PET) film. The double-sided tape 3 having second and third adhesive layers 31 and
`33 formed on both sides thereof is used, and the release film 4 is adhered onto outer
`sides of the second and third adhesive layers 31 and 33. The release film 4 is
`integrally formed during the manufacturing of the double-sided tape 3, and is peeled off
`and removed during the adhering of the shielding sheet 10 to the electronic device.
`
`Petitioner Samsung and Google Ex-1016, 0008
`
`

`

`9
`
`
`
`[69]
`To adhere a plurality of amorphous ribbon sheets 21 to 26 illustrated in FIG. 3
`
`to each other, double-sided tapes 3a to 3f inserted between amorphous ribbon sheets 21
`to 26 is used after removing both the release films 4 and 4b on both sides thereof.
`[70]
`As the double-sided tape 3 (3a to 3f), a type with the substrate as described
`
`above and a type formed only of an adhesive layer without the substrate can be applied.
`In the case of the double-sided tape 3a to 3f inserted between the amorphous ribbon
`sheets 21 to 26, it is preferable to use the type without the substrate from the viewpoint
`of slimness.
`[71]
`As the first to third adhesive layers 12, 31, and 33, for example, an acrylic
`
`adhesive may be used, and of course, other types of adhesive may be used.
`[72]
`The double-sided tape 3 may be used to have a thickness of 10, 20, and 30 m,
`
`and preferably has a thickness of 10 m.
`[73]
`The thin magnetic sheet 2 used for the shielding sheet 10 may have a thickness
`
`of, for example, 15 to 35 m per sheet. In this case, in consideration of the handling
`process after the heat treatment of the thin magnetic sheet 2, the thickness of the thin
`magnetic sheet 2 is preferably set to 25 to 30 m. As the thickness of the ribbon
`becomes thinner, even a slight impact during the handling after the heat treatment may
`cause the ribbon to break.
`[74]
`Meanwhile, when the receiving apparatus for a wireless charger is installed on a
`
`battery cover 5 of the portable terminal 100 and used, the magnetic field shielding sheet
`10 for a wireless charger in which, as illustrated in FIGS. 16 and 17, a secondary coil
`(receiving coil) 6 is adhered onto the shielding sheet 10 is used. In this case, since the
`secondary coil 6 forms a resonance circuit, the shielding sheet 10 affects the inductance
`of the resonance circuit formed by the secondary coil (receiving coil) 6.
`[75]
`In this case, the magnetic field shielding sheet 10 serves as magnetic shielding
`
`that blocks the effect of the wireless power signal from the transmitting apparatus on the
`portable terminal 100, and an inductor to induce a wireless power signal to be received
`with high efficiency to the secondary coil 6 of the receiving apparatus.
`[76]
`The thin magnetic sheet 2 is separated into multiple fine strands 20 by flake
`
`treatment, and the multiple fine strands 20 preferably have a size of several tens of m
`to 3 mm or less.
`[77]
`When the thin magnetic sheet 2 is subjected to the flake treatment and separated
`
`into the multiple fine strands 20, the decrease in magnetoresistance (R) is greater than
`the decrease in the inductance (L) value of the magnetic sheet. As a result, when the
`flake treatment of the thin magnetic sheet 2 is performed, a quality factor Q of the
`resonance circuit formed by the secondary coil 6 of the receiving apparatus increases,
`thereby increasing power transmission efficiency.
`[78]
`In addition, when the thin magnetic sheet 2 is separated into the multiple fine
`
`strands 20, it is possible to block the problem of heat generation of the battery by
`red