as) United States
`a2) Patent Application Publication 10) Pub. No.: US 2010/0007215 Al
`
`(43) Pub. Date: Jan. 14, 2010
`Sakuma
`
`US 20100007215A1
`
`(54) SOFT MAGNETIC SHEET, MODULE
`INCLUDING THE SHEET AND
`NON-CONTACT POWER TRANSMISSION
`SYSTEM INCLUDING THE MODULE
`
`(75)
`
`Inventor:
`
`Sadakatsu Sakuma, Sendai-shi
`(JP)
`
`Correspondence Address:
`FRISHAUF, HOLTZ, GOODMAN & CHICK, PC
`220 Fifth Avenue, 16TH Floor
`NEW YORK,NY 10001-7708 (US)
`
`(73) Assignee:
`
`NEC TOKIN Corporation,
`Sendai-shi (JP)
`
`(21) Appl. No.:
`
`12/499,215
`
`(22)
`
`Filed:
`
`Jul. 8, 2009
`
`(30)
`
`Foreign Application Priority Data
`
`(JP) oeeee 2008-180583
`Jul. 10, 2008
`(JP) oo. ee eee cee eeeerees 2008-247346
`Sep. 26, 2008
`Publication Classification
`
`(51)
`
`Int. Cl.
`(2006.01)
`HOIF 38/14
`(2006.01)
`HOIF 3/10
`(52) US. CMe coeeccccsescssssssssssssssnseeeseeseees 307/104; 335/297
`
`(57)
`
`ABSTRACT
`
`A non-contact power transmission system comprises a power
`receiver and a power transmitter. The power transmitter
`includes a transmitter coil. The power receiver includes a
`module which comprises a coil sheet and a soft magnetic
`sheet stacked on the coil sheet. The coil sheet includes a
`receiver coil. Electric poweris transmitted from the transmit-
`ter coil to the receiver coil. The soft magnetic sheet comprises
`a pair of insulation films and a soft magnetic member her-
`metically interposed between the insulation films.
`
`23a
`
`13a \,
`
`fF 11(31)
`CXXD 12(33)
`13
`
`22
`CXXD
`[ 21
`
`24
`
`11
`
`EXO
`
`2
`
`23
`OOOO)
`22
`21 po
`
`

`

`Patent Application Publication
`
`Jan. 14,2010 Sheet 1 of 8
`
`US 2010/0007215 Al
`
`45
`
`13a a
`23a
`MW OO=ooo 1181)
`12
`OOOO TF) OOOO
`12(33)
`
`23
`
`
`22 OOOO—7OOOO
`21 [ [2
`
`13
`
`24
`
`FIG.1
`
`

`

`Patent Application Publication
`
`Jan. 14,2010 Sheet 2 of 8
`
`US 2010/0007215 Al
`
`
` SIFY.}
`
`
`FIG.2A
`
`12(33)
`
`
`
`
`
`
`“ig/kd4
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`
`
`
`
`
`FIG.2B
`
`

`

`Patent Application Publication
`
`Jan. 14,2010 Sheet 3 of 8
`
`US 2010/0007215 Al
`
`
`
`FIG.3B
`
`

`

`Patent Application Publication
`
`Jan. 14,2010 Sheet 4 of 8
`
`US 2010/0007215 Al
`
`43
`
`33
`
`Ay
`
`\2
`“a
`
`
`
`FIG4
`
`

`

`Patent Application Publication
`
`Jan. 14,2010 Sheet 5 of 8
`
`US 2010/0007215 Al
`
`34
`
`12
`}
`
`(
`
`33
`
`31a2
`
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`
`45
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`31al
`
`FIG.5A
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`34 12/
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`33
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`45
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`3ial
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`FIG.5B
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`12
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`31b
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`A5
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`3lai
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`3ial
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`FIG.SC
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`1la——
`
`

`

`Patent Application Publication
`
`Jan. 14,2010 Sheet 6 of 8
`
`US 2010/0007215 Al
`
`1?
`
`34 /
`
`33
`
`51
`
`11
`ee
`55
`
`32
`
`32
`
`32
`
`52
`
`FIG.6A
`
`1 Im
`
`32
`
`30
`
`52
`
`1b
`
`FIG.6B
`
`

`

`Patent Application Publication
`
`Jan. 14,2010 Sheet 7 of 8
`
`US 2010/0007215 Al
`
`34
`
`«+12
`
`/ 33CD 3
`
`1 Im~
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`bene a 32
`3)
`
`32
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`3)
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`61
`
`54
`
`FIG.7
`
`

`

`Patent Application Publication
`
`Jan. 14,2010 Sheet 8 of 8
`
`US 2010/0007215 Al
`
`
`
`

`

`US 2010/0007215 Al
`
`Jan. 14, 2010
`
`SOFT MAGNETIC SHEET, MODULE
`INCLUDING THE SHEET AND
`NON-CONTACT POWER TRANSMISSION
`SYSTEM INCLUDING THE MODULE
`
`CROSS REFERENCE TO RELATED
`APPLICATIONS
`
`[0001] An applicant claimspriority under 35 U.S.C. §119
`of Japanese Patent Application No. JP2008-180583 filed Jul.
`10, 2008 and Japanese Patent Application No. JP2008-
`247346 filed Sep. 26, 2008.
`
`BACKGROUND OF THE INVENTION
`
`[0002] This invention relates to anon-contactor contactless
`powertransmission system based on electromagnetic induc-
`tion betweencoils.
`[0003] One of the non-contact or contactless powertrans-
`mission systems comprises a power receiver and a power
`transmitter. The powerreceiver includes a receiver coil, while
`the power transmitter includes a transmitter coil. Without
`direct contact between the transmitter coil and the receiver
`coil, electric poweris transmitted from the transmitter coil to
`the receiver coil on thebasis ofthe electromagnetic induction
`caused therebetween. For example, such non-contact power
`transmission system is used in a power supply system for
`supplying electric power to an artificial heart. Other appli-
`cable arts are a power supply system for a hand-held device,
`an IC tag system, a battery charger system andso on.
`[0004] Effective power transmission system is disclosed in
`JP-A 2003-45731, the contents of which are incorporated
`herein by reference. The disclosed powertransmission sys-
`tem comprises twocoils, 1.e. a receiver coil and a transmitter
`coil, and a ferrite sheet. The ferrite sheet includes a plurality
`of soft magnetic ferrite chips and is arranged on an outside of
`one of the coils.
`[0005] Recently, a non-contact power transmission system,
`especially a powerreceiver is required to have a low-profile.
`For the low-profile requirement, a soft magnetic sheet such as
`the above-mentioned disclosed sheet is also required to be
`thinned. However, a thin soft magnetic sheet may be break-
`able whena force is applied to the soft magnetic sheet; if the
`soft magnetic sheet is broken, magnetic powderis scattered
`from the broken sheet within/outofthe powerreceiver. There
`is a need for a thin soft magnetic sheet which is used for a
`powerreceiver of a non-contact power transmission system
`and which can prevent scattering of magnetic power even
`when a force is applied to the soft magnetic sheet.
`
`SUMMARYOF THE INVENTION
`
`[0006] One aspect of the present invention providesa soft
`magnetic sheet comprising a pair of insulationfilms anda soft
`magnetic memberhermetically interposed between the insu-
`lation films.
`
`[0007] Another aspect of the present invention provides a
`module which comprises the above-mentioned soft magnetic
`sheet and a coil sheet stacked on the soft magnetic sheet, the
`coil sheet comprising a coil.
`[0008] Another aspect of the present invention provides a
`non-contact power transmission system which comprises a
`powerreceiver and a powertransmitter, the power receiver
`comprising the above-mentioned module.
`[0009] An appreciation of the objectives of the present
`invention and a more complete understandingofits structure
`
`may be had by studying the following description of the
`preferred embodimentandbyreferring to the accompanying
`drawings.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1is across-sectional view schematically show-
`[0010]
`ing apart ofa non-contact powertransmission system accord-
`ing to an embodimentof the present invention, wherein the
`non-contact power transmission system comprises a power
`transmitter and a powerreceiver.
`[0011]
`FIG. 2A is a perspective view schematically show-
`ing a soft magnetic sheet of the powerreceiver of FIG.1.
`[0012]
`FIG. 2B is a perspective view schematically show-
`ing a part of the powerreceiver of FIG.1, the power receiver
`including the soft magnetic sheet of FIG. 2A.
`[0013]
`FIG. 3A is a perspective view schematically show-
`ing a modification of the soft magnetic sheet of FIG. 2A.
`[0014]
`FIG. 3B is a perspective view schematically show-
`ing a modification ofthe powerreceiver of FIG. 2B, the power
`receiver including the soft magnetic sheet of FIG. 3A.
`[0015]
`FIG. 4 is an exploded, perspective view schemati-
`cally showing a modification of the powerreceiver of FIG.1.
`[0016]
`FIG. 5A is a cross-sectional view schematically
`showing a modification of the powerreceiver of FIG. 1
`[0017]
`FIG. 5B is a cross-sectional view schematically
`showing another modification ofthe powerreceiver ofFIG.1.
`[0018]
`FIG. 5C is a cross-sectional view schematically
`showing another modification ofthe powerreceiver ofFIG.1.
`[0019]
`FIG. 6A is a cross-sectional view schematically
`showing a part of another modification of the power receiver
`of FIG. 1, wherein theillustrated part correspondsto the right
`part or the left part of FIG. 5B or FIG. 5C.
`[0020]
`FIG. 6B is a cross-sectional view schematically
`showing a part of another modification of the power receiver
`of FIG. 1, wherein theillustrated part correspondsto the right
`part or the left part of FIG. 5B or FIG. 5C.
`[0021]
`FIG. 7isacross-sectional view schematically show-
`ing a part of another modification of the powerreceiver of
`FIG.1, wherein the illustrated part correspondsto the right
`part or the left part of FIG. 5B or FIG. 5C.
`[0022]
`FIG. 8A is a perspective view schematically show-
`ing a modification of the soft magnetic sheet of FIG. 2A.
`[0023]
`FIG. 8B is a perspective view schematically show-
`ing another modification of the soft magnetic sheet of FIG.
`2A.
`
`FIG. 8C is a perspective view schematically show-
`[0024]
`ing another modification of the soft magnetic sheet of FIG.
`2A.
`
`[0025] While the invention is susceptible to various modi-
`fications and alternative forms, specific embodiments thereof
`are shown by way of example in the drawings and will herein
`be describedin detail. It should be understood, however, that
`the drawings and detailed description thereto are not intended
`to limit the invention to the particular form disclosed, but on
`the contrary,
`the intention is to cover all modifications,
`equivalents and alternatives falling within the spirit and scope
`ofthe present invention as defined by the appendedclaims.
`
`DESCRIPTION OF PREFERRED
`EMBODIMENTS
`
`[0026] With reference to FIG. 1, a non-contact or contact-
`less power transmission system according to an embodiment
`of the present invention comprises a power receiver 1 and a
`powertransmitter2.
`
`

`

`US 2010/0007215 Al
`
`Jan. 14, 2010
`
`[0027] The power receiver 1 comprises a soft magnetic
`sheet 11, a coil sheet 12, a receiver housing 13 anda circuit
`board 45. The soft magnetic sheet 11 is mounted on the circuit
`board 45. The coil sheet 12 is stacked on the soft magnetic
`sheet 11. The coil sheet 12 includes a receiver coil 33, as
`described later, which is connectedto a circuit pattern formed
`on the circuit board 45. The receiver housing 13 is made of
`insulator and accommodates the soft magnetic sheet 11, the
`coil sheet 12 and the circuit board 45.
`
`[0028] With reference to FIGS. 2A and 2B, the soft mag-
`netic sheet 11 comprises a pair of insulation films 32 and a
`soft magnetic member 31, wherein the insulation films 32 are
`partially omitted in FIG.2Bfor the sake of better understand-
`ing. The soft magnetic member31 ofthe present embodiment
`is fixed betweenthe insulation films 32. Specifically, the soft
`magnetic member 31 is hermetically interposed between the
`insulation films 32. In other words, the soft magnetic member
`31 has a laminate structure. Each ofthe insulationfilms 32 is
`
`made of a polyester film. However, the present invention is
`not limited thereto. The insulation film 32 may be made of
`other materials.
`
`[0029] The soft magnetic member 31 of the present
`embodiment comprises ten soft magnetic pieces 311. Each of
`the soft magnetic pieces 311 has a smalltile shape. However,
`the present inventionis not limited thereto. The soft magnetic
`piece may have other shapes such as triangle and so on. In
`addition, the soft magnetic pieces 311 have the same shapes
`as each other. However, the present invention is not limited
`thereto. For example, as shown in FIGS. 3A and 3B, the soft
`magnetic member may be comprised of soft magnetic pieces
`31c, 31d, wherein the insulationfilms 32 are partially omitted
`in FIG. 3B for the sake of better understanding. Each of the
`soft magnetic pieces 31c has a rectangular shape. Each of the
`soft magnetic pieces 31d hasa similar shape to the soft mag-
`netic piece 31c but is formed with a depression which gener-
`ally has a half circle. The soft magnetic pieces 31d with
`depressions are arranged so as to form a circular depression
`whichis positioned at a center section of the soft magnetic
`member. The depression may have any other shape.
`[0030] The soft magnetic pieces 311 ofthe present embodi-
`mentare arrangedin one layerso as to constitute a single loop
`so that the soft magnetic member 31 has a center section
`which does not contain any soft magnetic piece 311. At the
`center section, the insulation films 31 are directly fixed to
`each other. The insulation films 31 may be formed with an
`opening at the center section.
`[0031] Thecoil sheet 12 comprises two insulation films and
`the receiver coil 33. The receiver coil 33 is hermetically
`interposed between the insulation films. In other words, the
`coil sheet 12 has a laminate structure so that the receivercoil
`
`33 is insulated from the outside of the receiver coil 33 by the
`insulation films. The material of the receiver coil 33 of the
`
`[0032] The receiver housing 13 is formed with a depression
`portion 13a. The depression portion 13a is positioned to
`correspondto the center section ofthe soft magnetic sheet 11.
`The depression portion 13a of the present embodimenthas a
`rounded rectangular shape. However, the depression portion
`13a may have any shape.
`[0033] With reference to FIG. 1, the power transmitter 2
`comprises a soft magnetic sheet 21, a coil sheet 22, a trans-
`mitter housing 23 and a circuit board 24 for supplying electric
`power. The soft magnetic sheet 21 has the samestructure as
`the soft magnetic sheet 11. The coil sheet 22 has the same
`structure as the coil sheet 12, wherein the coil ofthe coil sheet
`22 is used as a transmitter coil. However, the soft magnetic
`sheet 21 and/or the coil sheet 22 may have otherstructures.
`The transmitter coil is connected to a circuit pattern formed
`on the circuit board 24. The electric power1s transmitted from
`the transmitter coil of the coil sheet 22 to the receiver coil 33.
`
`[0034] The transmitter housing 23 is formed with a protu-
`berant portion 23a whichis fittable with the depression por-
`tion 13a. The protuberant portion 23a is positioned to corre-
`spond to the center section of the soft magnetic sheet 21.
`Upon the fitting of the protuberant portion 23a with the
`depression portion 13a, the receiver coil 33 and the transmit-
`ter coil are arranged to surround the protuberant portion 23a
`and the depression portion 13a, while the transmitter coil of
`the coil sheet 22 is positioned in correspondence with the
`receiver coil 33 of the coil sheet 12, as shown in FIG. 1. The
`positional correspondence between the receiver coil 33 and
`the transmitter coil enhances powertransmissionefficiencies.
`In this embodiment, the depression portion 13a is formed as
`a part of the receiver housing 13, while the protuberant por-
`tion 23a is formed as a part of the transmitter housing 23.
`Alternatively, the depression portion may be formedas a part
`of the transmitter housing 23, while the protuberant portion
`maybe formedasa part of the receiver housing 13.
`[0035] The powerreceiver 1 may be modified as shown in
`FIG. 4. The illustrated circuit board 45 is provided with
`positioning marks 41. The insulation films 32 of the soft
`magnetic sheet 11 are also provided with positioning marks
`41. Likewise, the insulation films 34 of the coil sheet 12 are
`also formed with positioning marks 41. The positional corre-
`spondence among the positioning marks 41 provides a suit-
`able stacking of the circuit board 45, the soft magnetic sheet
`11 and the coil sheet 12. The positioning marks 41 may have
`any other shapes.
`[0036]
`Inthis modification,the circuit board 45is provided
`with electronic components 44. In consideration of the elec-
`tronic components 44, the soft magnetic sheet 11 andthe coil
`sheet 12 are provided with cut-offlike portions 42, 43, respec-
`tively. Because of the cut-off like portions 42, 43, the soft
`magnetic sheet 11 and the coil sheet 12 are prevented from
`being undesirably bent when the soft magnetic sheet 11 and
`the coil sheet 12 are stacked on the circuit board 45.
`
`In the above-mentioned embodiment, both of the
`[0037]
`present embodimentis a litz wire, but the present invention is
`powerreceiver 1 and the power transmitter 2 comprise the
`not limited to a specific material. The coil sheet 12 is attached
`respective soft magnetic sheets 11, 21. Depending uponits
`to the soft magnetic sheet 11 so that an inside area of the
`used environment, any one of the powerreceiver 1 and the
`receiver coil 33 correspondsto the center section of the soft
`power transmitter 2 may comprise a soft magnetic sheet.
`magnetic sheet 11, as apparent from FIG. 2B. The coil sheet
`However,it is preferable that the powerreceiver 1 comprises
`12 mayhaveotherstructures. For example, the coil sheet may
`the soft magnetic sheet 11.
`be formedasaprinted circuit board in which a coil is printed
`
`on a substrate or board. The coil sheet may haveastructure a [0038] In the above-mentioned embodiment, the soft mag-
`
`discrete coil fixed on an insulation sheet. The coil sheet may
`netic sheet comprises a uniform thickness of the soft mag-
`consist of a discrete coil which is formed of turns ofself-
`netic member31, and the numberofthe soft magnetic sheet is
`only one. However,
`the present invention is not
`limited
`
`welding wire.
`
`

`

`US 2010/0007215 Al
`
`Jan. 14, 2010
`
`thereto. For example, the soft magnetic sheet may have a
`mount portion and a surrounding portion, wherein the
`receiver coil of the coil sheet is mounted on the mount por-
`tion, and the surrounding portion has a thickness larger than
`another thickness of the mount portion. The non-uniform
`thickness of the soft magnetic sheet is embodied in for
`example FIGS. 5A to 5C. The soft magnetic sheet 11 of FIG.
`5A comprises soft magnetic pieces 31a1 and soft magnetic
`pieces 31a2. Each of the soft magnetic pieces 31a1 has a
`uniform thickness. On the other hand, each of the soft mag-
`netic pieces 31a2 has an L-shaped cross-section, i.e. a non-
`uniform thickness. The soft magnetic pieces 31@1 andthe soft
`magnetic pieces 31a2 are arranged so that the soft magnetic
`sheet 11 has a thinner section and a thicker section, wherein
`the thinner section serves as the mount portion, while the
`thicker portion serves as the surroundingportion. The thicker
`portion, i.e. the surrounding portion enhances powertrans-
`mission characteristics.
`
`[0039] Although the soft magnetic sheet 11 ofFIG. 5A does
`not have the above-mentioned center section, the soft mag-
`netic sheet may have the center section even if the soft mag-
`netic sheet has the surrounding portion. For example, the soft
`magnetic sheet 11 of FIG. 5B comprises soft magnetic pieces
`31a1 and soft magnetic pieces 31a2 which are arranged so
`that the soft magnetic sheet 11 has a thinner section and a
`thicker section, similar to FIG. 5A.In addition, the soft mag-
`netic sheet 11 of FIG. 5B is provided with the center section
`which does not contain any soft magnetic member. Further-
`more, a similar structure of the soft magnetic sheet 11 may be
`formed of two soft magnetic sheets which have different
`shapes than each other, as shown in FIG.5C. In FIG. 5C, each
`ofthe soft magnetic sheet 11a and the soft magnetic sheet 115
`has a uniform thickness of the soft magnetic members. How-
`ever, the soft magnetic memberofthe soft magnetic sheet 115
`has a large aperture in comparison with the soft magnetic
`sheet 11a. Note here that the soft magnetic sheets ofFIGS. 5A
`to 5C are schematically illustrated so that the insulation films
`32 are not shown.
`
`Instead ofthe soft magnetic pieces the soft magnetic
`[0040]
`sheet 11 may have one or more soft magnetic plate. For
`example, the soft magnetic sheet 11 of FIG. 6A comprises
`two soft magnetic plates 51 and 52, which are bonded
`together by using an adhesive agent 55. It is preferable that the
`adhesive agent 55 has a small Young’s modulus and a small
`contractibility upon hardening process. Theillustrated soft
`magnetic plates 51 and 52 are made of materials different
`from each other. The module of FIG. 6B comprises three soft
`magnetic sheets 11,, 11,, and 11,. The upper soft magnetic
`sheet 11,, has a frame shape. The middle soft magnetic sheet
`11,, is made of a material same as that of the upper soft
`magnetic sheet 11,, but has a normal plate-like shape. The
`bottom soft magnetic sheet 11, is made ofa material different
`from the middle soft magnetic sheet 11,, but has the same
`shape as the middle soft magnetic sheet 11,,. Note here that
`each ofthe modules of FIGS. 6A and 6B hasa structure which
`hasa thinnersection and a thicker section similar to FIGS. 5A
`to 5B.
`
`FIG. 7 showsanother modification of the module.
`[0041]
`The module of FIG. 7 comprises two soft magnetic sheets
`11,, 11,. The soft magnetic sheet 11,, has a normal sheet-like
`soft magnetic member 54. On the other hand, the soft mag-
`netic sheet 11, has a soft magnetic member 51 which is
`provided with a magnetic gap 61. The magnetic gap 61 is
`positioned just below the coil 33 so as to enhance the mag-
`
`netic saturation characteristic of the module of FIG.7. It is
`preferable that the soft magnetic member 51 has a large
`permeability such as ferrite or metallic soft magnetic mate-
`rial. The ferrite is for example Mn—Zn ferrite or Ni—Zn
`ferrite. The metallic soft magnetic material is for example
`sendust. The soft magnetic member 54 serves to prevent
`magnetic leakage. The soft magnetic member 54 is made of
`an electromagnetic interference suppression sheet which
`comprises sendust flakes dispersed and arranged into resin
`binder. The modification may be further modified in consid-
`eration ofFIG. 6A. Specifically, the soft magnetic member 51
`and the soft magnetic member54 are bondedtogether, and the
`whole members 51, 54 are hermetically interposed between
`two insulation films 32.
`
`[0042] Although the soft magnetic member31 ofthe soft
`magnetic sheet 11 of FIG. 2A consists of the soft magnetic
`pieces 311 which are sameaseach other, the present invention
`is not limited thereto. The soft magnetic sheet may consist of
`two or more kinds of soft magnetic pieces, depending uponits
`used environment.In detail, ifhigh insulation is required only
`in a particular region, soft magnetic pieces with higher insu-
`lation characteristic should be used for the particular region.
`For example, between Mn—Zn based ferrite and Ni—Zn
`based ferrite, Ni—Zn based ferrite should be used for the
`particular region; instead, Mn—7Znbasedferrite may be used
`for the other region otherthan theparticular region. Likewise,
`if heat generation components are arranged only ona specific
`region, soft magnetic pieces with higher Curie points should
`be used for the specific region. For example, between
`Mn—Zn based ferrite and Ni—Zn based ferrite, Ni—7Zn
`based ferrite should be used for the specific region; instead,
`Mn—nbasedferrite may be used for the other region other
`thanthe specific region.
`[0043]
`InFIG. 8A, two kindsof soft magnetic pieces 51, 52
`are used. The soft magnetic pieces 52 are arranged only on
`one side edge; the other area are occupied by the other soft
`magnetic pieces 51. This is the case which hasthe particular
`region or the specific region as mentioned above. In FIG. 8B,
`two kinds of soft magnetic pieces 51, 52 are used but are
`arranged in a checkered flag pattern so that their magnetic
`characteristics are averaged. In addition, the soft magnetic
`sheet of FIG. 8C comprises two layers of soft magnetic
`pieces. In this embodiment, the numberof the soft magnetic
`pieces of the upperlayer is equal to the numberofthe soft
`magnetic pieces of the lowerlayer. In other words, the soft
`magnetic pieces belonging to the upper layer is equal in
`numberto the soft magnetic pieces belonging to the lower
`layer. The lower layer comprises two kinds of soft magnetic
`pieces 51, 52 are used but are arranged in a checkered flag
`pattern, similar to FIG. 8B. The upper layer comprises one
`kind of soft magnetic pieces 53.
`
`Example 1
`
`[0044] Thenon-contact power transmission system accord-
`ing to an example 1 was fabricated and evaluated. The present
`example 1 is based on FIGS. 1, 2A and 2B. Eachofthe soft
`magnetic pieces 311 was madeof sintered spinelle ferrite
`which had permeability of about 2500 and saturation magne-
`tization of about 0.5 T (5000 G). The size of each piece 311 is
`11 mmx11 mmx1 mm.The insulation films 32 were made of
`
`polyester films. The soft magnetic sheet 21 had a structure
`same as the soft magnetic sheet 11. The receiver coil was
`formedoffive turns oflitz wire, which was formed ofa bundle
`of ten copper-based self welding wires each having a diam-
`
`

`

`US 2010/0007215 Al
`
`Jan. 14, 2010
`
`eter of 100 um. The receiver coil hada rectangular loop shape
`which had an outer size of 35 mmx25 mm while having an
`inner size of 25 mmx15 mm; the thicknessofthe receiver coil
`was 1.5 mm. The receiver coil was interposed between the
`insulationfilms of polyester. The coil sheet 22 had a structure
`same as the coil sheet 12. The protuberant portion 23a had a
`shape of 3 mmx18.5 mmx8.5 mm,while the depression por-
`tion 13a had a shape of 3 mmx20 mmx10 mm. Under the
`conditions of frequency of 100 kHz and a primary voltage
`level of 4 V, a secondary voltage level P2 andits transforma-
`tion efficiency 1 was evaluated, where n=(output power/input
`power)x100 (%). The evaluated secondary voltage level P2
`was8 W, while the evaluated transformation efficiency n was
`58%. These evaluated values show good powertransmission
`capability.
`
`Example 2
`
`Whatis claimedis:
`1. A soft magnetic sheet comprising:
`a pair of insulation films; and
`a soft magnetic memberfixed betweenthe insulationfilms.
`2. The soft magnetic sheet according to claim 1, wherein
`the soft magnetic memberis hermetically interposed between
`the insulation films.
`3. The soft magnetic sheet according to claim 1, wherein
`the soft magnetic member comprises two or more soft mag-
`netic pieces.
`4. The soft magnetic sheet according to claim 3, wherein
`the soft magnetic pieces are arranged in onelayer.
`5. The soft magnetic sheet according to claim 3, wherein
`the soft magnetic pieces are arranged in two or morelayers,
`each of layers comprising two or more of the soft magnetic
`pieces.
`6. The soft magnetic sheet according to claim 5, wherein
`the soft magnetic pieces belonging to one of the layers are
`equal in number to the soft magnetic pieces belonging to
`Similar evaluation was carried out for the case of
`[0045]
`another oneofthe layers.
`FIGS. 3A and 3B. The soft magnetic piece 31c hadasize of
`7. The soft magnetic sheet according to claim 3, wherein
`35 mmx11 mmx1 mm. Thehalf circle shaped depression of
`the soft magnetic pieces are grouped into at least two groups,
`the soft magnetic piece 31d had a radius of 5 mm. The other
`the groups being madeof materials different from each other.
`conditions were same as those of the above-mentioned
`8. The soft magnetic sheet according to claim 1, wherein
`example 1. The evaluated secondary voltage level P2 was 8 W,
`the soft magnetic member comprises two or more soft mag-
`while the evaluated transformation efficiency n was 59%
`netic plates which are stacked each other.
`9. The soft magnetic sheet according to claim 8, wherein
`These evaluated values show good powertransmission capa-
`the soft magnetic plates are grouped into at least two groups,
`bility.
`the groups being madeof materials different from each other.
`10. The soft magnetic sheet according to claim 2, including
`a center section which does not contain the soft magnetic
`memberat which the insulationfilmsare directly fixed to each
`other.
`11.A module comprising the soft magnetic sheet according
`to claim 1 and a coil sheet stacked on the soft magnetic sheet,
`the coil sheet comprising a coil.
`12. The module according to claim 11, wherein the coil
`sheet is a laminate structure comprising twofilms andthe coil
`hermetically interposed therebetween.
`13. The module according to claim 11, wherein the soft
`magnetic sheet including a mountportion and a surrounding
`portion, the coil being positioned on the mountportion, the
`surrounding portion having a thickness larger than another
`thickness of the mount portion.
`14. A non-contact powertransmission system comprising a
`powerreceiver and a power transmitter, the power receiver
`comprising the module according to claim 11.
`15. The non-contact powertransmission system according
`to claim 14, wherein: the powerreceiver comprises a receiver
`housing; the power transmitter comprises a transmitter hous-
`ing; one ofthe receiver housing andthe transmitter housing is
`provided with a protuberantportion, while a remaining one of
`the receiver housing and the transmitter housing is provided
`with a depression portion; and the protuberant portion is fit
`with the depression portion whenthe powertransmitter trans-
`mits powerto the powerreceiver.
`16. The non-contact powertransmission system according
`to claim 15, wherein the coil ofthe module serves as a receiver
`coil of the power receiver; the power transmitter includes a
`transmitter coil; the receiver coil and the transmitter coil are
`arranged to surround the protuberant portion and the depres-
`sion portion.
`
`Example 3
`
`Similar evaluation was carried out for the case of
`[0046]
`FIG. 5B. The thinner portion had a thickness of 1 mm. The
`thicker portion had a thickness of 2.5 mm. The other condi-
`tions were sameas those of the above-mentioned example1.
`The evaluated secondary voltage level P2 was 8 W, while the
`evaluated transformation efficiency 7 was 68%. As under-
`stood from the evaluation, the thicker portion enhances the
`transformation efficiency 1.
`
`Example 4
`
`[0047] Evaluation was carried out for the case of FIG.7.
`The soft magnetic member 51 was made of Mn—7Znferrite
`and had a shape of 11 mmx5 mmx1 mm. The magnetic gap 61
`ofthe soft magnetic member 51 was 1 mm. The soft magnetic
`member 54 was made of an electromagnetic interference
`suppression sheet which comprised sendust powerdispersed
`in resin binder. The magnetic gap 61 prevented magnetic
`saturation, while the electromagnetic interference suppres-
`sion sheet prevented magnetic leakage. In addition, the soft
`magnetic sheet was allowedto have a radius ofcurvature of30
`mm.
`
`[0048] The present application is based on Japanese patent
`applications of JP2008-180583 and JP2008-247346 filed
`before the Japan Patent Office on Jul. 10, 2008 and Sep. 26,
`2008, respectively, the contents of which are incorporated
`herein by reference.
`[0049] While there has been described whatis believed to
`be the preferred embodimentofthe invention, those skilled in
`the art will recognize that other and further modifications may
`be made thereto without departing from the spirit of the
`invention, andit is intended to claim all such embodiments
`that fall within the true scope of the invention.
`
`