(12) United States Patent
`Yang et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 8,268,092 B2
`Sep. 18, 2012
`
`USOO8268092B2
`
`(54)
`
`(75)
`
`(73)
`(*)
`
`(21)
`(22)
`(65)
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`(62)
`
`MAGNETIC SHEET FOR RADIO
`FREQUENCY IDENTIFICATION ANTENNA,
`METHOD OF MANUFACTURING THE SAME,
`AND RADIO FREQUENCY IDENTIFICATION
`ANTENNAUSING THE SAME
`
`Inventors: Jae Suk Yang, Gyeonggi-do (KR);
`Hyeon Chul Lim, Gyeonggi-do (KR):
`Byoung Ki Lee, Gyeonggi-do (KR):
`Yong Sup Lee, Gyeonggi-do (KR); Yong
`Hyun Kim, Gyeonggi-do (KR); Yong
`Sul Song, Seoul (KR); Sang Kyun
`Kwon, Gyeonggi-do (KR); Beom Jin
`Kim, Seoul (KR)
`Assignee: Amotech Co., Ltd., Incheon (KR)
`Notice:
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 138 days.
`Appl. No.: 12/841,347
`
`Filed:
`
`Jul. 22, 2010
`
`Prior Publication Data
`US 2010/0288418 A1
`Nov. 18, 2010
`
`Related U.S. Application Data
`Division of application No. 1 1/410,110, filed on Apr.
`25, 2006, now abandoned.
`Foreign Application Priority Data
`
`(30)
`Apr. 26, 2005
`Mar. 16, 2006
`
`(KR) ........................ 10-2005-OO34460
`(KR) ........................ 10-2006-0O24493
`
`(51)
`
`(52)
`(58)
`
`(56)
`
`Int. C.
`(2006.01)
`HOIF I/47
`(2006.01)
`HOIF I/I6
`U.S. Cl. ......................... 148/121; 148/120; 427/131
`Field of Classification Search ........................ None
`See application file for complete search history.
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`... 148/108
`4,705,578 A * 1 1/1987 Lin et al. ...
`... 428,328
`4,992,329 A * 2/1991 Ishii et al.
`2005/0162331 A1* 7/2005 Endo et al. .................... 343,788
`* cited by examiner
`Primary Examiner — John Sheehan
`(74) Attorney, Agent, or Firm — Rosenberg, Klein & Lee
`
`
`
`ABSTRACT
`(57)
`Provided are a magnetic sheet for use in a radio frequency
`identification (RFID) antenna, an RFID antenna including the
`magnetic sheet, and a method of manufacturing the magnetic
`sheet, in which the magnetic sheet includes an amorphous
`alloy selected from the group consisting of Fe-Si-B,
`Fe-Si B Cu Nb, Fe–Zr B and Co-Fe-Si B.
`The magnetic sheet is made by laminating amorphous alloy
`ribbons made of an amorphous alloy between magnetic sheet
`layers formed of alloy powder including at least one amor
`phous alloy and then compression-molding the amorphous
`alloy ribbons, to thereby control microcrack of the amor
`phous alloy ribbons and enhance characteristic of an end
`product. The magnetic sheet is also thin, and has an excellent
`magnetic permeability, and a simple manufacturing process.
`
`5 Claims, 12 Drawing Sheets
`
`AMORPHOUS RBBON
`
`PULVERIZATION
`
`MIXING O E R E S N
`
`MOLDING OF MIXTURE SHEET
`
`ROLLING OF MIXTURE SHEET
`
`M
`
`ATION
`
`ROLLING OF LAMINA
`TED SHEET
`
`COATING
`
`EXAMINATION
`
`S1
`
`S2
`
`S3
`
`S4.
`
`S5
`
`S6
`
`S7
`
`S8
`
`Petitioner Samsung and Google Ex-1013, 0001
`
`

`

`U.S. Patent
`
`Sep. 18, 2012
`
`Sheet 1 of 12
`
`US 8,268,092 B2
`
`FIG 1.
`
`100
`
`
`
`200
`
`3
`
`READER
`
`6 TRANSPONDER
`
`FIG. 2A
`
`
`
`Petitioner Samsung and Google Ex-1013, 0002
`
`

`

`U.S. Patent
`
`Sep. 18, 2012
`
`Sheet 2 of 12
`
`US 8,268,092 B2
`
`FIG 2B
`
`3O
`
`
`
`ZZZZZZZZZZZZZZZ
`
`
`
`FIG. 3A
`
`31
`
`
`
`Petitioner Samsung and Google Ex-1013, 0003
`
`

`

`U.S. Patent
`
`Sep. 18, 2012
`
`Sheet 3 of 12
`
`US 8,268,092 B2
`
`FIG 3B
`
`31
`
`FIG 3 C,
`
`31
`
`
`
`
`
`
`
`
`
`11
`
`...
`
`.
`
`S.
`
`Petitioner Samsung and Google Ex-1013, 0004
`
`

`

`U.S. Patent
`
`Sep. 18, 2012
`
`Sheet 4 of 12
`
`US 8,268,092 B2
`
`FIG 3D
`
`31
`
`
`
`11
`
`
`
`16
`
`FIG 3E
`
`31
`
`
`
`
`
`
`
`NISRSINNSNNN
`
`11
`
`15
`
`Petitioner Samsung and Google Ex-1013, 0005
`
`

`

`U.S. Patent
`
`Sep. 18, 2012
`
`Sheet 5 of 12
`
`US 8,268,092 B2
`
`FIG 4A
`
`FIG 4B
`
`
`
`Petitioner Samsung and Google Ex-1013, 0006
`
`

`

`U.S. Patent
`
`Sep. 18, 2012
`
`Sheet 6 of 12
`
`US 8,268,092 B2
`
`FIG 5A
`
`
`
`Sh,
`S.
`S. S.
`s
`
`FG 5B
`
`33
`
`
`
`1.5-11
`
`
`
`Petitioner Samsung and Google Ex-1013, 0007
`
`

`

`U.S. Patent
`
`Sep. 18, 2012
`
`Sheet 7 of 12
`
`US 8,268,092 B2
`
`FIG. 5 C.
`
`33
`
`18
`11
`
`
`
`
`
`SNNNNNNNESS
`
`F.G. 6
`
`25
`
`
`
`(s
`N N N
`
`Petitioner Samsung and Google Ex-1013, 0008
`
`

`

`U.S. Patent
`
`Sep. 18, 2012
`
`Sheet 8 of 12
`
`US 8,268,092 B2
`
`FIG 7
`
`AMORPHOUS RIBBON
`
`PULVERIZATION
`
`MIXING OF RESIN
`
`MOLDING OF MIXTURE SHEET
`
`S1
`
`S2
`
`S3
`
`S4
`
`ROLLING OF MIXTURE SHEET l-NuS5
`
`AMINATION
`
`N - S6
`
`ROLLING OF LAMINATED SHEET
`
`COATING
`
`EXAMINATION
`
`S7
`
`- S8
`
`S9
`
`Petitioner Samsung and Google Ex-1013, 0009
`
`

`

`U.S. Patent
`
`Sep. 18, 2012
`
`Sheet 9 of 12
`
`US 8,268,092 B2
`
`FIG 8
`
`44.
`
`43
`44a
`
`
`
`42
`
`44b
`
`Petitioner Samsung and Google Ex-1013, 0010
`
`

`

`U.S. Patent
`
`Sep. 18, 2012
`
`Sheet 10 of 12
`
`US 8,268,092 B2
`
`47
`
`
`
`FIG 9
`
`45a
`
`-
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`Petitioner Samsung and Google Ex-1013, 0011
`
`

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`U.S. Patent
`
`Sep. 18, 2012
`
`Sheet 11 of 12
`
`US 8,268,092 B2
`
`FIG 10
`
`45a
`46a
`
`45b.
`
`46b
`
`45C
`
`
`
`2
`
`Petitioner Samsung and Google Ex-1013, 0012
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`

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`U.S. Patent
`
`Sep. 18, 2012
`
`Sheet 12 of 12
`
`US 8,268,092 B2
`
`FIG. 12A
`
`
`
`Petitioner Samsung and Google Ex-1013, 0013
`
`

`

`US 8,268,092 B2
`
`1.
`MAGNETIC SHEET FOR RADIO
`FREQUENCY IDENTIFICATION ANTENNA,
`METHOD OF MANUFACTURING THE SAME,
`AND RADIO FREQUENCY IDENTIFICATION
`ANTENNAUSING THE SAME
`
`RELATED APPLICATIONS
`
`This application is a Divisional patent application of co
`pending application Ser. No. 1 1/410,110, filed on 25 Apr.
`2006. The entire disclosure of the prior application Ser. No.
`11/410,110, from which an oath or declaration is supplied, is
`considered a part of the disclosure of the accompanying Divi
`sional/Continuation application and is hereby incorporated
`by reference.
`
`10
`
`15
`
`BACKGROUND OF THE INVENTION
`
`2
`ingly, if the energy is delivered to the tag antenna, that is,
`toward the transponder antenna through the reader antenna,
`the transponder is activated and the reader receives data from
`the tag antenna.
`The RFID system of the frequency region as described
`above, achieves mutual communications by an inductive
`electromagnetic coupling of a transformer mode. For this
`purpose, the tag antenna may be formed of a rectangular
`planar spiral inductor. In this case, communications are
`achieved by a LC resonance of an antenna, in which a reso
`nant frequency is determined by the inductance of an inductor
`and the capacitance of a capacitor. Generally it is important
`that a transponder is designed to employ a parallel resonance
`circuit, in which it is designed to obtain the maximum imped
`ance at the resonant frequency by the LC resonance in order
`to obtain the maximum Voltage with the minimum current.
`FIG. 1 illustrates a radio frequency identification (RFID)
`system including a reader 100 and a transponder 200 between
`which data communications are achieved by an inductive
`coupling mode. The reader 100 includes an oscillator 1 for
`producing an electromagnetic wave of 13.56MHz, a capaci
`tor 2, a resistor 3, and a coil 8. In the transponder 200, a
`magnetic field 6 generated from the coil 8 in the reader 100
`reaches a radio frequency identification (RFID) antenna coil
`7 attached to the transponder 200 and thus voltage is induced
`across the coil 7. The induced Voltage passes through the
`capacitor 2 connected in parallel with the RFID antenna coil
`7 and a diode 4 connected in series with the RFID antenna coil
`7 and thus direct-current (DC) voltage is supplied to a radio
`frequency identification (RFID) chip 5.
`As the RFID chip 5 is supplied with the DC voltage, the
`transponder 200 is activated to transfer ID information stored
`in the RFID chip 5 to the reader 100 through the RFID
`antenna coil 7.
`In this case, the Voltage induced in the tag antenna is
`determined by the Faradays law and Lenz’s law. Therefore,
`it becomes more advantageous to obtain a higher Voltage
`signal, as a more amount of magnetic flux interlink with the
`transponder antenna coil. The amount of the magnetic flux
`becomes larger, as an amount of a soft magnetic material
`included in the transponder antenna coil becomes larger and
`the magnetic permeability of the soft magnetic material
`becomes higher. Particularly, since the RFID system per
`forms contactless data communications intrinsically, it is nec
`essary to have an absorber sheet which is made of a magnetic
`material having a high magnetic permeability in order to
`focus a radio frequency electromagnetic wave which is made
`in the reader antenna on the tag antenna.
`In the case of an antenna coil for use in a generally given
`transponder, an inductance of the antenna coil is in proportion
`to the magnetic permeability of the magnetic material. In a
`communications process, as the inductance of the transpon
`der antenna becomes high, higher Voltage is induced propor
`tionally to the inductance of the transponderantenna. Accord
`ingly, if a magnetic material having a higher magnetic
`permeability is employed as a material of the absorber sheet
`for the tag antenna, a data communication distance is
`increased and an error probability of data can be lowered.
`The conventional magnetic material for use in an absorber
`sheet for a mobile phone RFID antenna is fabricated into a
`sheet form which is formed by mixing the ferrite including
`Mn-Zn group oxide or Ni-Zn group oxide together with
`resin. In the conventional technology, it is very difficult to
`tune the LC resonance circuit since an inductance deviation of
`the transponder antenna is serious due to the non-uniformity
`of the thickness of these ferrites. Moreover, the non-unifor
`mity exceeding the error range of the thickness may cause
`
`1. Field of the Invention
`The present invention relates to a magnetic sheet for use in
`a radio frequency identification (RFID) antenna, a method of
`manufacturing the same, and a radio frequency identification
`(RFID) antenna using the magnetic sheet. More particularly,
`the present invention relates to a magnetic sheet for use in a
`radio frequency identification (RFID) antenna, a method of
`manufacturing the same, and a radio frequency identification
`(RFID) antenna using the magnetic sheet, in which the mag
`netic sheet is a mono-layer structure which is made of alloy
`powder including at least one amorphous alloy, or a multi
`layer structure which is formed by laminating an amorphous
`alloy ribbon made of an amorphous alloy between magnetic
`sheet layers and compression-molding the same.
`2. Description of the Related Art
`Recently, a radio frequency identification (RFID) system
`communicating data between a transponder including an inte
`grated circuit (IC) chip and a reader/writer, or between a
`transponder and a reader is being widely spread. Since the
`RFID system communicates data using a respective antenna
`which is included in a transponder and a reader/writer, the
`transponder and the reader/writer do not need to contact each
`other to communicate data therebetween. Thus, although the
`transponder is far from the reader/writer by several centime
`ters to several tens of centimeters, they can communicate each
`other. Since the radio frequency identification (RFID) system
`is not sensitive to contamination or static electricity, it is being
`used in various fields including a production control in a
`factory, the administration of physical distribution, an inven
`tory control, and an entrance and exit control.
`For example, mobile phones employ a radio frequency
`identification (RFID) system. Generally, the mobile phone
`includes a main body and a battery unit which are separably
`combined with each other. In the case of the mobile phone
`using the RFID system, the main body includes an integrated
`circuit (IC) chip on a surface which contacts the battery unit,
`and the battery unit includes a tag antenna on the reverse
`Surface which does not contact the main body and a battery on
`the surface which contacts the main body.
`The tag antenna and the battery forming the battery unit
`may be incorporated in a plastic case. Here, the IC chip of the
`main body and the tag antenna of the battery unit play a role
`of a transponder of the RFID system, and these communicate
`data with a reader positioned at the outside of the mobile
`phone. In more detail, in the case of a RFID mobile phone
`chiefly using the frequency of 135 kHz or less or 13.56MHz,
`especially, an inductive mode, a reader antenna produces a
`sine wave which is a radio frequency electromagnetic wave,
`using mainly using the frequency of 13.56 MHz. Accord
`
`25
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`30
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`35
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`60
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`65
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`Petitioner Samsung and Google Ex-1013, 0014
`
`

`

`US 8,268,092 B2
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`10
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`15
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`25
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`30
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`35
`
`3
`difficulty of an installation when a magnetic sheet is attached
`in a battery pack space, and an error occurs in the process of
`the formation and transmission of binary code data during the
`mutual transmission process of data, to thereby make a very
`high inferiority ratio, as well.
`Moreover, the recent mobile phone adopts high functions
`Such as a game, a video communication, an Internet function
`addition, and a camera. Accordingly, an amount of the power
`consumption increases. As a result, it is necessary to have the
`Volume of a battery as large as possible. Furthermore, minia
`turization and thin shaping of a device is being progressed.
`But in the case that the absorber sheet for the RFID antenna
`made of ferrite is in the thickness of 0.35 mm or less, the
`inductance for the RFID communications of the transponder
`antenna is low. In this case, the communications distance is
`excessively shortened, that is, the quality of performance is
`not implemented. As a result, development of a new material
`is acutely needed.
`In the meantime, the Moly Permalloy Powder (MPP) con
`taining permalloy or molybdenum (Mo) having an excellent
`Soft magnetic property is used as a magnetic material of an
`absorber for a mobile phone RFID antenna. The Permalloy or
`MPP is excellent in view of a soft magnetic property in
`comparison with ferrite and thus is used as the absorber sheet
`for the mobile phone RFID antenna even in the thickness of
`0.2 mm. However, since the powder manufactured in the form
`of a spherical shape should be pulverized into the nano size
`and made to be flat, the manufacturing process is complicated
`and the original material is expansive.
`As described above, in the conventional technology, in the
`case of the ferrite or the Permalloy containing the molybde
`num used as the magnetic material, these are formed of the
`crystalline of the spherical shape irrespective of the process
`ing condition. Therefore, complicated processes such as a
`micro-powdered process and then a flatness process should be
`undergone in order to manufacture the absorber sheet of the
`thin thickness of 0.2 mm or less using the ferrite or the
`Permalloy containing the molybdenum. Moreover, since
`these conventional materials have the problem that an effec
`40
`tive cross-sectional area of the material representing the mag
`netic property cannot be secured as the thickness of the con
`ventional materials is thinner, it has a limitation in
`heightening the inductance necessary for securing the dis
`tance of the RFID communications. Also, since a thickness of
`45
`the conventional materials is uneven during manufacturing,
`the deviation of inductance becomes serious.
`Besides, U.S. Pat. No. 6,887,412 describes a composite
`magnetic sheet and method of producing the same capable of
`Suppressing electromagnetic interference. The composite
`magnetic sheet includes composite magnetic bodies having
`flat soft powder subjected to annealing to be free from stress
`strain and a binder. The composite magnetic sheet is pressed
`by the press or the rolling mill having the rolls in a direction
`perpendicular to the plane of the sheet. Further, multiple
`composite magnetic sheets are stacked by sandwiching Al
`plate or wire.
`However, the magnetic permeability of the magnetic sheet
`is not high even in the thin thickness below 0.35 mm. While
`some of the objects and the structural components of U.S. Pat.
`No. 6,887,412, at first appearance, have similarities with the
`present invention, U.S. Pat. No. 6,887,412 differs in amor
`phous alloy powder composition and structural respects.
`These differences, which will be described in more detail
`hereinafter, are essential for the effective use of the invention
`and which admit of the advantages that are not available with
`the prior devices.
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`50
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`4
`SUMMARY OF THE INVENTION
`
`The inventors have proved the fact that these inventors
`could manufacture a magnetic sheet having the thin and uni
`form thickness of 0.35 mm or less in comparison with an
`existing metal sheet at the low cost with the minimum pro
`cess, since the magnetic sheet includes an amorphous alloy
`selected from the group consisting of Fe-Si-B, Fe-Si
`B Cu Nb, Fe—Zr Band Co-Fe-Si B, and an alloy
`ribbon is directly manufactured into a thin film type of 0.03
`mm or less.
`Moreover, in the case of the magnetic sheet made of the
`amorphous alloy, the Saturation magnetic flux density 0.57
`T-1.6 T is much higher than the saturation magnetic flux
`density 0.45 T of the existing ferrite, and the magnetic per
`meability is high even in the thin thickness. Accordingly, the
`inventors have discovered the fact that the magnetic flux
`which modulates in the RFID communications can be effec
`tively focused on the transponder antenna coil. In addition,
`the inventors has discovered the fact that the electromagnetic
`waves of 0.9 GHz and 1.9 GHz frequency band having no
`concern with the RFID communications, and the several
`gigahertz (GHz) band which is the harmonic component of
`standard communications electromagnetic wave bands, dur
`ing the communications process of the cellular phone, with
`out having the metal layer, in comparison with the ferrite
`sheet, can be blocked effectively. The conventional problem
`can be solved in the case that the magnetic sheet is used as the
`absorber for the RFID antenna of the portable device includ
`ing the mobile phone.
`Thus, an object of the present invention is to provide a
`magnetic sheet for a radio frequency identification (RFID)
`antenna comprising an amorphous alloy consisting of the
`above-described composition, and a RFID antenna including
`the magnetic sheet.
`To solve the above problems, it is another object of the
`present invention to provide a magnetic sheet for use in a
`radio frequency identification (RFID) antenna, an RFID
`antenna including the magnetic sheet, and a method of manu
`facturing the magnetic sheet, in which the magnetic sheet is
`made by laminating amorphous alloy ribbons made of an
`amorphous alloy between magnetic sheet layers formed of
`alloy powder including at least one amorphous alloy and then
`compression-molding the amorphous alloy ribbons, to
`thereby provide a multilayer structure of a simple process of
`manufacturing a thin magnetic sheet and having an excellent
`magnetic permeability.
`To accomplish the above object of the present invention,
`there is provided a magnetic sheet for a radio frequency
`identification (RFID) antenna comprising having an amor
`phous alloy of a composition selected from the group con
`sisting of Fe—S B, Fe—Si- B-Cu- Nb, Fe—Zr—B,
`and Co-Fe-S. B.
`Moreover, according to another aspect of the present inven
`tion, there is also provided a magnetic sheet for a radio fre
`quency identification (RFID) antenna comprising an alloy
`which is obtained by heat-treating an amorphous alloy
`selected from the group consisting of Fe-Si-B, Fe-Si
`B Cu—Nb, Fe–Zr B, and Co-Fe-Si B.
`The magnetic sheet according to the present invention can
`be formed by laminating a magnetic sheet layer formed of a
`mixture of amorphous alloy powder of the above-described
`composition and a resin, and a slit amorphous alloy ribbon.
`Alloys of two or more compositions of the above-described
`compositions may be mixed in the magnetic sheet.
`According to another aspect of the present invention, there
`is provided a magnetic sheet for a radio frequency identifica
`
`Petitioner Samsung and Google Ex-1013, 0015
`
`

`

`5
`tion (RFID) antenna made of amorphous alloy powder
`including at least one kind of an amorphous alloy selected
`from the group consisting of Fe-Si-B, Fe-Si-B-Cu
`Nb, Fe—Zr—B, and Co-Fe-Si Banda resin for a binder
`mixed with the amorphousalloy powder in order to be molded
`into a sheet form.
`The amorphous alloy powder and the binder resin are
`mixed with a weight ratio in the range of 5:1 through 9:1.
`According to still another aspect of the present invention,
`there is also provided a method of manufacturing a magnetic
`sheet for a radio frequency identification (RFID) antenna, the
`magnetic sheet manufacturing method comprising the steps
`of mixing amorphous alloy powder including at least one
`kind of an amorphous alloy selected from the group consist
`ing of Fe—Si B, Fe—Si B Cu—Nb, Fe—Zr B, and
`Co-Fe-Si Band a resin for a binder; and depositing the
`mixture on a base member in the form of a thin film and then
`drying the deposited base member, to thereby obtain a dried
`magnetic sheet.
`According to yet another aspect of the present invention,
`there is also provided a multi-layered magnetic sheet for a
`radio frequency identification (RFID) antenna, the multi-lay
`ered magnetic sheet comprising: first and second magnetic
`sheet layers made of alloy powder including at least one kind
`of an amorphous alloy selected from the group consisting of
`Fe-Si B, Fe-Si B Cu Nb, Fe–Zr B, and
`Co-Fe-Si B; and a first amorphous alloy ribbon includ
`ing at least one kind of the amorphous alloys and which is
`laminated between the first and second magnetic sheet layers.
`Preferably, the magnetic sheet for the RFID antenna further
`comprises: a secondamorphousalloy ribbon laminated on the
`surface of any one of the first and second magnetic sheet
`layers and made of one kind of the amorphous alloys; and a
`third magnetic sheet layer which is laminated on the Surface
`of the second amorphous alloy ribbon and manufactured with
`the alloy powder including at least one kind of the amorphous
`alloy.
`In this case, since the amorphous alloy ribbon laminated
`between the mixed sheets causes the microcrack to occur
`through a rolling or a press of the sheet thereby dropping
`down a loss, the frequency characteristic being the disadvan
`tage of the amorphous alloy ribbon can be enhanced, and a
`complicated process which is slit in order to use an existing
`amorphous alloy ribbon. In this case, it is possible that the
`capacity of a battery is extended in a battery pack of the same
`thickness or the thickness of the battery pack is made into an
`ultra thin type, since inductance necessary for RFID commu
`nications can be effectively obtained.
`According to a yet still another aspect of the present inven
`tion, there is provided a method of manufacturing a magnetic
`50
`sheet for a radio frequency identification (RFID), the mag
`netic sheet manufacturing method comprising the steps of
`preparing first and second magnetic sheet layers made of
`alloy powder including at least one kind of an amorphous
`alloy selected from the group consisting of Fe-Si-B,
`Fe—Si B Cu—Nb, Fe—Zr—B, and Co-Fe-Si B;
`preparing a first amorphous alloy ribbon made of one kind of
`the amorphous alloys; and laminating the first amorphous
`alloy ribbon between the first and second magnetic sheet
`layers and then compression-molding the laminated multi
`layer magnetic sheet layer in order to increase a relative
`density of the laminated magnetic sheet layer and simulta
`neously form a microcrack on the first amorphous alloy rib
`bon.
`The method of manufacturing the magnetic sheet for the
`RFID, further comprises the steps of preparing a second
`amorphous alloy ribbon made of one kind of the amorphous
`
`6
`alloys and a third magnetic sheet layer made of alloy powder
`including at least one kind of the amorphous alloys; and
`before rolling the laminated magnetic sheet layer, laminating
`the second amorphous alloy ribbon on the Surface of any one
`of the first and second magnetic sheet layers and laminating
`the third magnetic sheet layer on the surface of the second
`amorphousalloy ribbon.
`Moreover, the step of compression-molding the laminated
`multilayer magnetic sheet layer can be executed by one of hot
`rolling, hot pressing, cold rolling, and cold pressing.
`It is preferable that the amorphous alloy is heat-treated at
`the temperature of 300° C. to 600° C. for ten hours or less in
`order to have the grain size of the nanometer (nm) unit.
`The thickness of the multi-layered magnetic sheet can be
`manufactured in the form of a thin film of 0.2 mm or less.
`According to a further aspect of the present invention, there
`is also provided a magnetic sheet for a radio frequency iden
`tification (RFID), the RFID magnetic sheet comprising: a
`plurality of magnetic sheet layers which is made of alloy
`powder including at least one kind of an amorphous alloy
`selected from the group consisting of Fe-Si-B, Fe-Si
`B Cu—Nb, and Fe–Zr B, and Co-Fe-Si B; and a
`plurality of amorphous alloy ribbons which are made of at
`least one kind of the amorphous alloys and which are lami
`nated between the plurality of magnetic sheet layers.
`According to a still further aspect of the present invention,
`there is also provided a radio frequency identification (RFID)
`antenna comprising: a multi-layered magnetic sheet includ
`ing a plurality of magnetic sheet layers which is made of alloy
`powder including at least one kind of an amorphous alloy
`selected from the group consisting of Fe-Si-B, Fe-Si
`B Cu- Nb, and Fe—Zr B, and Co-Fe-Si B, and a
`plurality of amorphous alloy ribbons which are made of at
`least one kind of the amorphous alloys and which are lami
`nated between the plurality of magnetic sheet layers; an insu
`lating layer formed on the Surface of the magnetic sheet; and
`an antenna coil pattern which is patterned on the Surface of the
`insulating layer using a conductive material.
`Moreover, the present invention provides a radio frequency
`identification (RFID) device including a radio frequency
`identification (RFID) antenna according to another aspect of
`the present invention.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The above and other objects and advantages of the present
`invention will become more apparent by describing the pre
`ferred embodiment thereof in more detail with reference to
`the accompanying drawings in which:
`FIG. 1 is a circuit diagram showing a radio frequency
`identification (RFID) system of an inductive coupling mode:
`FIG. 2A is a perspective view showing structure of a radio
`frequency identification (RFID) antenna including a mag
`netic sheet for an absorber of a mono-layer structure in which
`the magnetic sheet is manufactured using amorphous alloy
`powder, according to a first embodiment of the present inven
`tion;
`FIG.2B is a cross-sectional view of a line A-A of FIG. 2A;
`FIG. 3A is a perspective view showing structure of a radio
`frequency identification (RFID) antenna including a mag
`netic sheet formed by laminating a magnetic sheet layer made
`of amorphous alloy powder and a slit-type amorphous alloy
`ribbon according to a second embodiment of the present
`invention;
`FIG. 3B is a cross-sectional view of a line B-B' of FIG.3A;
`FIGS. 3C through 3E are a cross-sectional view showing
`structure of a radio frequency identification (RFID) antenna
`
`US 8,268,092 B2
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`Petitioner Samsung and Google Ex-1013, 0016
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`US 8,268,092 B2
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`7
`including a modified magnetic sheet formed by laminating a
`magnetic sheet layer made of amorphous alloy powder and a
`slit-type amorphous alloy ribbon according to the second
`embodiment of the present invention, respectively;
`FIGS. 4A and 4B is a perspective view showing structure of
`a radio frequency identification (RFID) antenna including a
`slit-type amorphous alloy ribbon for use in an absorber
`according to a third embodiment of the present invention,
`respectively;
`FIG. 5A is a perspective view showing structure of a radio
`10
`frequency identification (RFID) antenna including a mag
`netic sheet layer formed by laminating a magnetic sheet layer
`made of amorphous alloy powder and a slit-type amorphous
`alloy ribbon according to a fourth embodiment of the present
`invention;
`FIG.SB is a cross-sectional view of a line C-C of the FIG.
`5A:
`FIG. 5C is a cross-sectional view showing structure of a
`radio frequency identification (RFID) antenna including a
`modified magnetic sheet formed by laminating a magnetic
`sheet layer made of amorphous alloy powder and a slit-type
`amorphous alloy ribbon according to the fourth embodiment
`of the present invention;
`FIG. 6 is a schematic sectional view of a cellular-phone
`battery including a radio frequency identification (RFID)
`antenna according to the first embodiment of the present
`invention;
`FIG. 7 is a flow-chart view for illustrating a manufacturing
`method of a magnetic sheet for use in a radio frequency
`identification (RFID) antenna according to a preferred fifth
`embodiment of the present invention;
`FIG. 8 is an illustrative view for illustrating a rolling pro
`cess of a mixture sheet molded in FIG. 7:
`FIG. 9 is a sectional view for illustrating a compression
`molding process of a magnetic sheet for use in a radio fre
`quency identification (RFID) antenna according to the pre
`ferred fifth embodiment of the present invention;
`FIG. 10 is a cross-sectional view of a modified magnetic
`sheet for use in a radio frequency identification (RFID)
`antenna according to the preferred sixth embodiment of the
`present invention;
`FIG. 11 is a cross-sectional view showing an example
`where a radio frequency identification (RFID) antenna which
`is manufactured using a magnetic sheet for use in a radio
`frequency identification (RFID) antenna according to the fifth
`embodiment according to the present invention is applied to a
`battery unit of a mobile phone; and
`FIGS. 12A and 12B are a sectional picture of a magnetic
`sheet which has not been compressed and molded and that of
`the magnetic sheet which has been compressed and molded,
`50
`respectively.
`
`30
`
`8
`B Cu—Nb, Fe—Zr—B, and Co-Fe-Si B. Accord
`ingly, the problem of the conventional technique can be
`resolved. Detailed description thereof will follow.
`In the case that an amorphousalloy made of a composition
`material selected from the group consisting of Fe-Si-B,
`Fe-Si B-Cu-Nb, Fe—Zr—B, and Co-Fe-Si B is
`used, a magnetic sheet having a thin and uniform thickness of
`0.35 mm or less can be manufactured. In the case of ferrite or
`Permalloy containing molybdenum used as a magnetic mate
`rial in the conventional technology, these form a spherical
`crystalline structure irrespective of a processing condition.
`Therefore, complicated processes such as a micro-powdered
`process and then a flatness process should be undergone in
`order to manufacture the sheet of the thin thickness of 0.35
`mm or less using the ferrite or the Permalloy containing the
`molybdenum. Moreover, since these conventional materials
`have the problem that an effective cross-sectional area of the
`material representing the magnetic property cannot be
`secured as the thickness of the conventional materials is thin
`ner, it has a limitation in heightening the inductance necessary
`for securing the distance of the RFID communications. Also,
`since a thickness of the conventional materials is uneven
`during manufacturing, the deviation of inductance becomes
`serious.
`However, since the model of the alloy which is used in the
`present invention is in the form of an amorphous ribbon
`shape, it can be easily fabricated into a sheet of a thin thick
`ness of 0.35 mm or less. In addition, the thickness of the sheet
`can be easily uniformly controlled. Therefore, since the
`present invention uses a thin and uniform magnetic sheetas an
`absorber for a radio frequency identification (RFID) antenna,
`the deviation of inductance is minimized and the tuning of an
`LC resonance circuit can be facilitated. An error occurring in
`the process of the formation and transmission of binary code
`data during the mutual transmission process of data can be
`reduced. In addition, the manufacturing process of the mag
`netic sheet becomes simple and the manufacturing cost
`becomes inexpensive.
`Moreover, although the conventional magnetic sheet mate
`rials have to include the separate metal layer in order to block
`the externally generated electromagnetic wave having no
`connection with the RFID communications, the amorphous
`alloy according to the present invention can focus the induc
`tive electromagnetic wave of 135 kHz o