JP2014107322A - Magnetic sheet, electronic apparatus and method of manufacturing magnetic sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic sheet whose magnetic characteristics are hardly deteriorated even if curved.SOLUTION: A magnetic sheet 100 has a plurality of magnetic pieces 20, 21 aligned parallel and arranged into a planar shape and satisfies both of the following conditions (A) and (B). The conditions are: (A) that end surfaces 30, 31 of neighboring magnetic pieces 20, 21 come into surface contact with each other; and (B) that the neighboring magnetic pieces 20, 21 are arranged at positions deviated from each other along the extension direction of the end surfaces 30, 31 which come into surface contact with each other.

Description

  The present invention relates to a magnetic sheet in which a plurality of magnetic pieces are arranged in a plane, an electronic device including the magnetic sheet, and a method for manufacturing the magnetic sheet.

  A thin and flexible magnetic sheet is desired in view of demands for reducing the thickness and improving the portability of various electronic devices such as a non-contact power supply device, a radiation noise absorber, and a communication antenna.

  With regard to this type of technology, Patent Document 1 discloses a magnetic material in which a ferrite sintered body sheet affixed to a base material is stretched and broken to be divided into tile-like pieces, and a gap between the pieces is filled with a resin. A sheet is disclosed. Thereby, it is said that the value of effective magnetic permeability can be controlled in a wide range, and a thin magnetic sheet can be obtained.

JP 2011-233740 A

  However, the magnetic sheet of Patent Document 1 has a problem that when the magnetic sheet is bent, a gap is generated between the pieces and the magnetic characteristics are deteriorated. FIG. 8 is a schematic diagram showing a problem of the magnetic sheet 200 of Patent Document 1. In FIG. FIG. 8A shows a state where the magnetic sheet 200 is flat, and FIG. 8B shows a state where the magnetic sheet 200 is curved. The magnetic sheet 200 is configured by arranging tile-shaped pieces (magnetic pieces 220 and 221) side by side on a base material 210. As shown in FIG. 8A, when the substrate 210 is flat, the end surfaces 230 and 231 of the adjacent magnetic pieces 220 and 221 are in surface contact with each other or are in close proximity to each other. When the substrate 210 is curved as shown in FIG. 8B, the substrate 210 extends at the boundary position between the magnetic pieces 220 and 221, and a gap 240 is generated between the end surfaces 230 and 231. More specifically, a gap 240 is formed on the side of the end surfaces 230 and 231 that is close to the substrate 210 (downward in the drawing), and the upper edges of the end surfaces 230 and 231 are in line contact. For this reason, the connection state of the magnetic pieces 220 and 221 becomes unstable.

  Here, when the gap 240 is generated between the adjacent magnetic pieces 220 and 221 and the surface contact state is lost, the magnetic circuit of the magnetic sheet 200 is interrupted, and the magnetic flux trapping property is lowered. For this reason, the magnetic sheet 200 of Patent Document 1 has a problem that when it is bent, the magnetic characteristics are unexpectedly deteriorated.

  The present invention has been made in view of the above-described problems, and provides a magnetic sheet that hardly deteriorates magnetic characteristics even when curved, a method for manufacturing the same, and an electronic device including the magnetic sheet.

According to the present invention, a magnetic sheet is provided in which a plurality of magnetic pieces are arranged side by side and satisfy both the following conditions (A) and (B).
(A) The end surfaces of the adjacent magnetic pieces are in surface contact with each other.
(B) The adjacent magnetic pieces are arranged at positions shifted from each other along the extending direction of the end face in surface contact.

  According to the above invention, when the magnetic sheet is bent in the extending direction, the adjacent magnetic pieces can be relatively rotated while being in surface contact with each other, so that the physical contact of the magnetic pieces is maintained. For this reason, the magnetic characteristics of the magnetic sheet can be stably maintained at least against the bending in the extending direction.

  Moreover, according to this invention, the electronic device containing said magnetic sheet, the coil which makes the thickness direction of the said magnetic sheet the winding axis direction, and the circuit board which supplies an alternating current to the said coil is provided.

  In addition, according to the present invention, there is provided a method of manufacturing a magnetic sheet in which a plurality of magnetic pieces are arranged in a plane, the step of creating a plurality of the magnetic pieces having the same shape, and the plurality of the magnetic pieces Placing the pieces in positions where the end faces are in surface contact with each other and shifted from each other along the extending direction of the end faces; and cutting the magnetic pieces to create a peripheral portion of the magnetic sheet. A method for producing a magnetic sheet is provided.

  ADVANTAGE OF THE INVENTION According to this invention, even if it curves, a magnetic sheet with few deterioration of a magnetic characteristic, its manufacturing method, and an electronic device provided with a magnetic sheet are provided. Thereby, the thickness reduction, repetition durability, usability, etc. of an electronic device provided with a magnetic sheet are improved.

(A) is a plane schematic diagram which shows the magnetic sheet 100 of 1st embodiment, (b) is an enlarged view of (a). (A) is a perspective view of a magnetic piece, (b) is an enlarged view of the vicinity of a convex part. (A) is a perspective view which shows typically the fitting state of a recessed part and a convex part, (b) is a perspective view which shows typically the state which the magnetic sheet curved in the X direction, (c) is ( It is a top view of a). (A) is a graph of the simulation result of the effective permeability of the magnetic sheet of the first embodiment when the bending angle is changed, and (b) is the effective permeability of the conventional magnetic sheet when the bending angle is changed. It is a graph of a simulation result of magnetic susceptibility. It is a partially cutaway top view of an electronic device. It is a plane schematic diagram which shows the cutting process in the manufacturing method of a magnetic sheet. (A) is a plane schematic diagram which shows the magnetic sheet of 2nd embodiment, (b) is explanatory drawing which shows a piece group. (A) is a schematic diagram which shows the state in which the conventional magnetic sheet is flat, (b) is a schematic diagram which shows the state in which the conventional magnetic sheet curved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same constituent elements are denoted by the same reference numerals, and redundant description is omitted as appropriate.

  In the present embodiment, there are cases where the vertical direction is defined and described, but this is provided for convenience in order to explain the relative positional relationship between the components, and at the time of manufacturing the product according to the present invention. It does not limit the direction during use. The term “surface” or “surface shape” as used in the present invention means a shape that can be recognized as substantially flat, and does not require a geometrically perfect plane.

<First embodiment>
FIG. 1A is a schematic plan view showing the magnetic sheet 100 of the first embodiment of the present invention. FIG. 1B is an enlarged view of FIG. 1A and 1B, the left-right direction in the figure is referred to as the X direction, and the up-down direction is referred to as the Y direction. FIG. 2A is a perspective view of the magnetic piece 20. FIG. 2B is an enlarged view of the vicinity of the convex portion 50 in the magnetic pieces 20 to 22. In each figure of FIG. 1, the magnetic pieces 20-22 are hatched for description.

First, the outline | summary of the magnetic sheet 100 of this embodiment is demonstrated.
The magnetic sheet 100 is characterized in that a plurality of magnetic pieces 20 and 21 are arranged in a plane and satisfy both the following conditions (A) and (B).
(A) The end surface 30 of the adjacent magnetic piece 20 and the end surface 31 of the magnetic piece 21 are in surface contact with each other.
(B) Adjacent magnetic pieces 20 and 21 are arranged at positions shifted from each other along the extending direction of the end faces 30 and 31 (X direction in the respective drawings in FIG. 1) in contact with each other.

  The magnetic pieces 20 and 21 are adjacent to each other in the left-right direction (X direction) in FIG. In the magnetic sheet 100 of the present embodiment, the magnetic pieces 20 and 22 are adjacent to each other in the vertical direction (Y direction) in FIG. That is, the magnetic pieces 20 to 22 satisfy both the above conditions (A) and (B) in two orthogonal directions.

Next, the magnetic sheet 100 of this embodiment will be described in detail.
The magnetic sheet 100 is an electronic component having a sheet shape as a whole and at least a part of which is composed of the magnetic pieces 20 to 22. The planar view shape of the magnetic sheet 100 is not particularly limited, and may be circular or rectangular (including a square). The planar view shape of the magnetic sheet 100 of this embodiment is a rectangular shape, and the four sides 80 to 83 extend in the X direction or the Y direction.

The magnetic pieces 20 to 22 are ferrite sintered bodies formed into individual pieces. As an example, the relative permeability (μ) is 100 or more and 2000 or less. As an example, the Young's modulus of the magnetic pieces 20 to 22 is 1 × 10 ⁴ [N / mm ² ] or more. The bending rigidity of the magnetic pieces 20 to 22 is significantly higher (for example, 100 times or more) than the entire bending rigidity of the magnetic sheet 100. A protective layer may be provided on the surfaces of the magnetic pieces 20 to 22. Moreover, you may fill with an inorganic or organic filler between adjacent magnetic pieces 20-22. Examples of the filler include magnetic powder or resin material kneaded with magnetic powder. In this embodiment, the end faces of the magnetic pieces are in surface contact with each other, in addition to the state in which the substrate or the protective layer of the end faces is in planar and physical contact, and the end faces with a filler interposed Including the state where is physically connected.

  The magnetic sheet 100 includes an adhesive sheet 10 that adheres and fixes a plurality of magnetic pieces 20 to 22 to the surface. The pressure-sensitive adhesive sheet 10 is a base material for the magnetic sheet 100. For the adhesive sheet 10, a magnetic film in which a magnetic material is mixed with a resin material such as polyolefin or polyester can be used. The Young's modulus of the pressure-sensitive adhesive sheet 10 is lower than the Young's modulus of the magnetic pieces 20 to 22 and is preferably less than 10%. The thickness dimension of the pressure-sensitive adhesive sheet 10 is not particularly limited, but is preferably smaller than the thickness dimension of the magnetic pieces 20 to 22 and more preferably less than 50 from the viewpoint of enhancing the flexibility of the magnetic sheet 100. The surface of the pressure-sensitive adhesive sheet 10 is subjected to pressure-sensitive adhesive processing, and the magnetic pieces 20 to 22 can be attached.

  The magnetic sheet 100 includes a flexible frame member 60 that surrounds the periphery of the magnetic pieces 20 to 22. A soft resin material such as rubber can be used for the frame member 60. The Young's modulus of the frame member 60 is lower than the Young's modulus of the magnetic pieces 20-22. By providing the frame member 60, it is possible to suppress the displacement of the magnetic pieces 20 to 22 in the X direction or the Y direction, and to physically protect the magnetic pieces 20 to 22. The frame member 60 preferably surrounds the entire circumference of the arrangement region of the magnetic pieces 20 to 22 without a gap, but is not limited thereto. As long as the magnetic pieces 20 to 22 can be held, the frame member 60 may be provided intermittently.

  The magnetic pieces 20 to 22 of the present embodiment have the same shape. The same shape means that the dimensions and form are substantially the same. The magnetic pieces 20 to 22 have a flat plate shape and include a central portion 42, a concave portion 40, and a convex portion 50. The convex portions 50 are formed so as to protrude from both sides of the central portion 42 (X direction in FIG. 2A). The magnetic pieces 20 to 22 include an extending portion 44 that protrudes in a direction orthogonal to the convex portion 50. The recess 40 is a gap between the pair of extending portions 44 arranged in the X direction. The projecting length of the extending portion 44 projecting in the Y direction is equal to the projecting length of the projecting portion 50 projecting in the X direction. A pair of extending portions 44 are respectively formed in an H shape so as to protrude from both sides in the Y direction with the central portion 42 as the center. Therefore, the magnetic pieces 20 to 22 include a total of two pairs of extending portions 44.

  In the present embodiment, the magnetic piece in which the protruding direction of the convex portion 50 faces the X direction is referred to as the first magnetic piece 20. And the magnetic piece in which the protrusion direction of the convex part 50 has faced the Y direction is called the 2nd magnetic piece 21. FIG. However, on the basis of the first magnetic piece 20, the piece having the concave portion 40 that fits the convex portion 50 is called a second magnetic piece 21, and the convex that fits the concave portion 40 of the first magnetic piece 20. The piece having the portion 50 may be referred to as the third magnetic piece 22 and distinguished for convenience.

  Each of the magnetic pieces 20 to 22 has a concave portion 40 and a convex portion 50. The convex portion 50 of the magnetic piece 20 is fitted with the concave portion 40 of the other adjacent magnetic pieces 21 and 22. The end surface 30 having the protruding direction as the extending direction in the convex portion 50 and the end surface 32 having the concave direction (Y direction) as the extending direction in the concave portion 40 are in surface contact with each other. In the present embodiment, the end surface of the magnetic piece is an upright surface extending in the thickness direction of the magnetic sheet in the outer surface of the magnetic piece, in other words, a partial region of the peripheral surface of the magnetic piece. The end surface may be a flat surface, or may be a curved surface formed by chamfering or the like like the tip edge 51 of the convex portion 50.

The first magnetic piece 20 has a first end face 30 and a second end face 32 whose extending directions intersect each other. In the present embodiment, the first end face 30 extends in the X direction, and the second end face 32 extends in the Y direction orthogonal thereto. The second end face 32 of the first magnetic piece 20 corresponds to the end face 31 of the second magnetic piece 21. The first end face 30 of the first magnetic piece 20 corresponds to the end face 33 of the third magnetic piece 22.
As shown in FIG. 1B, the first end face 30 of the first magnetic piece 20 is in surface contact with the end face 31 of the adjacent second magnetic piece 21. The first magnetic piece 20 and the second magnetic piece 21 are arranged at positions shifted from each other along the extending direction (X direction) of the first end face 30. Furthermore, the second end surface 32 of the first magnetic piece 20 is in surface contact with the end surface 33 of the adjacent third magnetic piece 22. The first magnetic piece 20 and the third magnetic piece 22 are arranged at positions shifted from each other along the extending direction (Y direction) of the second end surface 32.
Thereby, the 1st magnetic piece 20 and the 2nd magnetic piece 21, and also the 1st magnetic piece 20 and the 3rd magnetic piece 22 satisfy | fill the conditions of said (A) and (B), respectively.

  The magnetic pieces 20 to 22 of the present embodiment are opposed to the other adjacent magnetic piece on both the end face extending in the X direction and the end face extending in the Y direction.

  According to the present embodiment, even when the magnetic sheet 100 is bent in the X direction and when it is bent in the Y direction, the end surfaces 30 to 33 of the adjacent magnetic pieces 20 to 22 are maintained in a state of being in surface contact with each other. The characteristics are stable. Here, the fact that the magnetic sheet 100 is curved in the X direction means that the magnetic sheet 100 is curved so that one side in the X direction is lifted from the other side, as shown in FIG. In other words, the magnetic sheet 100 is bent with the Y direction as a crease or a bending axis. In the present invention, no distinction is made between bending and bending.

  In the present embodiment, the fact that adjacent magnetic pieces 20 to 22 are displaced from each other in a predetermined direction means that the centers of gravity of the adjacent magnetic pieces 20 to 22 are at different positions in the predetermined direction. More specifically, the gravity center positions in the X direction of the magnetic pieces 20 and 21 adjacent in the X direction are different from each other. The gravity center positions of the magnetic pieces 20 and 22 adjacent in the Y direction in the Y direction are different from each other.

  As shown in FIG. 2A, at least one of the leading edge 51 of the convex portion 50 or the deepest edge 41 of the concave portion 40 is chamfered. Thereby, the magnetic sheet 100 is configured such that one of the leading edge 51 or the deepest edge 41 does not interfere with the other during bending. Here, the fact that the leading edge 51 of the convex portion 50 and the deepest edge 41 of the concave portion 40 do not interfere with each other does not contact each other or slides smoothly without substantial friction. Specifically, as shown in FIG. 2B, in the present embodiment, the tip edge 51 of the convex portion 50 is chamfered in an arc shape (R chamfering) in the thickness direction. And the front edge 51 of the convex part 50 and the deepest edge 41 of the recessed part 40 are non-contact in the state where the magnetic sheet 100 is flat. Thereby, the leading edge 51 does not interfere with the deepest edge 41, and the leading edge 51 does not damage the adhesive sheet 10 (see FIG. 3B) when the magnetic sheet 100 is curved.

  In the magnetic pieces 20 to 22 of the present embodiment, chamfering (R chamfering) is also applied to the leading edge 45 of the extending portion 44 located on both sides of the recess 40. Thereby, when the magnetic sheet 100 is curved, the leading edge 45 of the extending portion 44 does not interfere with other adjacent magnetic pieces.

  In addition, the end surface 30 connected to the front end edge 51 of the convex portion 50 is formed flat, and is not chamfered in the width direction (that is, the Y direction) of the convex portion 50 (see FIG. 2B). Thereby, substantially the entire end surface 30 corresponding to the side surface of the convex portion 50 of the magnetic piece 20 comes into surface contact with the end surface 31 corresponding to the inner surface of the concave portion 40 of the magnetic piece 21.

  FIG. 3A is a perspective view schematically showing a fitting state of the concave portion 40 and the convex portion 50. The figure shows a state in which the magnetic sheet 100 is flat. The extension portion 44 is partially omitted from illustration. FIG. 3B is a perspective view schematically showing a state in which the magnetic sheet 100 is bent in the X direction. The pressure-sensitive adhesive sheet 10 is curved so that one side in the X direction (the right side in the case of the figure) is lifted. FIG. 3C is a plan view of FIG.

  In the flat state shown in FIGS. 3A and 3C, the end surfaces 30 on both sides of the convex portion 50 are in surface contact with the end surfaces 31 on both sides of the concave portion 40. That is, the dimension of the convex part 50 and the recessed part 40 in the width direction (Y direction) is equal. Further, the leading edge 45 of the extending part 44 is not in contact with the magnetic piece 20, and the leading edge 51 of the convex part 50 is not in contact with the deepest edge 41 of the concave part 40.

  In the curved state of FIG. 3B, the magnetic piece 20 rotates relative to the magnetic piece 21 relative to the Y direction from the flat state. In the curved state, the surface contact between the end faces 30 and 31 is maintained. That is, the hinge 50 swings while the convex portion 50 and the concave portion 40 are in surface contact. An angle formed by the magnetic pieces 21 and 20 is defined as a bending angle θ. The magnetic pieces 20 and 21 have contact surfaces (end surfaces 30, 31) perpendicular to the surfaces facing each other (the leading edge 51 and the deepest edge 41). Thereby, when the magnetic sheet 100 is curved so that the magnetic pieces 20 and 21 are relatively rotated in the plane of the end faces 30 and 31, the surface contact state of the magnetic pieces 20 and 21 can be maintained.

  The contact area between the end faces 30 and 31 in the flat state may be smaller than the contact area in the curved state. In general, the contact area between the magnetic pieces 20 and 22 is not a bottleneck of the magnetic properties of the magnetic sheet 100. For this reason, as long as the magnetic pieces 20 and 22 maintain a surface contact state, even if the contact area is small, the magnetic characteristics of the magnetic sheet 100 do not deteriorate significantly.

FIG. 4A is a graph of a simulation result showing the effective permeability μ _e of the magnetic sheet 100 when the bending angle θ is changed from 0 degree to 45 degrees in the curved state shown in FIG. The state where the bending angle θ = 0 ° corresponds to the flat state shown in FIG. FIG. 4B is a graph of the simulation result of the effective permeability μ _e of the conventional magnetic sheet 200 when the bending angle θ is changed from 0 degree to 45 degrees in the curved state shown in FIG. is there. Except for the presence or absence of the concave portion 40 and the convex portion 50, the dimensions of the magnetic pieces 20, 21 and the magnetic pieces 220, 221 and the conditions of relative permeability were common. Moreover, the adhesive sheet 10 and the base material 210 were disregarded.

In the magnetic sheet 100 of this embodiment shown in FIG. 3A, the leading edge 51 of the convex portion 50 of the magnetic piece 20 and the leading edge 45 of the extending portion 44 of the magnetic piece 21 are chamfered, so that the bending angle The effective permeability μ _{e at} θ = 0 degree is about 900, which is slightly lower than the effective permeability μ _e (about 1050) in the conventional magnetic sheet 200. This is because the conventional magnetic sheet 200 covers the base 210 over substantially the entire surface of the magnetic pieces 220 and 221 as shown in FIG.

In contrast, the bending when the angle θ is increased from 0 degrees, the conventional magnetic sheet 200 is effective permeability mu _e is plunged. Specifically, it decreases to about 250 at θ = 10 degrees and to about 100 at θ = 30 degrees. Based on the flat state, the conventional magnetic sheet 200 decreases to about 24% at θ = 10 degrees and to about 10% at θ = 30 degrees.

On the other hand, the magnetic sheet 100 of the present embodiment, reduction of the bending angle effective permeability even began to increase from 0 degrees theta mu _e is moderate. Specifically, it can be seen that an effective permeability μ _e of about 820 is maintained at θ = 10 degrees, and about 550 is maintained even at θ = 30 degrees. On the basis of the flat state, the magnetic sheet 100 of this embodiment has an effective magnetic permeability μ _e of about 91% at θ = 10 degrees and about 61% at θ = 30 degrees.

  As described above, in the magnetic sheet 100 of the present embodiment, the magnetic pieces 100 can be curved without greatly degrading the magnetic characteristics by swinging the hinges while the magnetic pieces 20 to 22 are in surface contact with each other. I understood. For this reason, it is possible to increase flexibility while maintaining the magnetic characteristics of the magnetic sheet 100.

  Returning to FIG. 1A, the first magnetic pieces 20 are arranged in a staggered pattern without any gaps. Here, arbitrary line segments L1, L2,... (Illustrated by two-dot chain lines) extending in the arrangement direction (X direction and Y direction) of the magnetic pieces 20 to 22 are assumed. These line segments L1 and L2 are line segments orthogonal to the sides 80 to 83 of the magnetic sheet 100 at an arbitrary position. In the magnetic sheet 100 of the present embodiment, at least one magnetic piece 20 positioned on the line segments L1 and L2 and another magnetic piece 21 or 22 adjacent to the one magnetic piece 20 are the above (A) and Both conditions (B) are satisfied. For this reason, the magnetic sheet 100 of the present embodiment has the first magnetic piece 20 and the second or third magnetic pieces 21, 22 even when curved in any position in the X direction or the Y direction. Surface contact can be maintained. In particular, the magnetic sheet 100 according to the present embodiment is in plane contact with the adjacent magnetic pieces 20 to 22 even when the magnetic sheet 100 is bent in all directions, including a compound curve in the X direction and the Y direction. The state can be maintained.

  The outer peripheral edges of the magnetic pieces 20 to 22 located on the periphery of the magnetic sheet 100 may be formed flat. For this reason, it is good to remove the convex part 50 regarding the magnetic pieces 20-22 of a periphery. Further, the rectangular replenishment piece 24 may be arbitrarily arranged in the recess 40 that opens toward the frame member 60. For the replenishment piece 24, a convex portion 50 cut out from the magnetic pieces 20 to 22 may be used.

<Electronic equipment>
FIG. 5 is a partially cutaway plan view of the electronic device 120 including the magnetic sheet 100 of the present embodiment. A part of the surface protection sheet 130 of the electronic device 120 is cut out. The broken line of the protection sheet 130 is shown with a dashed-dotted line.

  The electronic device 120 includes a magnetic sheet 100, a coil 140 whose winding direction is the thickness direction of the magnetic sheet 100, and a circuit board 150 that supplies an alternating current to the coil 140. The electronic device 120 of this embodiment is a non-contact power supply device.

  A plurality of coils 140 are arranged in a single layer or multiple layers on the surface of the magnetic sheet 100. In the electronic device 120 of this embodiment, the coil 140 is fixed to the surface of the magnetic sheet 100. The circuit board 150 includes a power supply terminal 152 and a wiring 154 that connects the power supply terminal 152 and the coil 140.

  An alternating magnetic field is generated in the coil 140 by connecting the power supply terminal 152 to an external power source (not shown) and energizing the coil 140 with an alternating current. The coil 140 is a power transmission coil. Here, the magnetic sheet 100 captures and amplifies the magnetic flux generated by the coil 140. When a device to be charged (not shown) including a power receiving coil is placed on the surface of the electronic device 120, the device to be charged is contactlessly charged.

  Instead of this embodiment, a drive mechanism (not shown) for driving the coil 140 may be provided along the surface of the magnetic sheet 100, and the coil 140 may be installed unfixed to the magnetic sheet 100. The drive mechanism may be controlled so that the coil 140 is moved to the place where the device to be charged is placed, and the alternating magnetic field may be generated locally instead of the entire electronic device 120.

  The magnetic sheet 100 of the present embodiment can be used for various electronic devices such as a radiation noise absorber, a communication antenna, and a speaker, in addition to the non-contact power feeding device exemplified above.

<Manufacturing method>
Hereinafter, a method for manufacturing the magnetic sheet 100 (hereinafter sometimes referred to as the present method) will be described. FIG. 6 is a schematic plan view showing a cutting process in the present method. In the present method, the second magnetic piece 21 and the third magnetic piece 22 are not distinguished. In FIG. 6, the magnetic pieces 20 and 21 are hatched for explanation.

First, an outline of this method will be described.
This method is a method for manufacturing a magnetic sheet 100 in which a plurality of magnetic pieces 20 and 21 are arranged in a plane. The method includes a piece creation process, a placement process, and a cutting process. The piece creation process is a process of creating a plurality of magnetic pieces 20 and 21. An arrangement | positioning process is a process of arrange | positioning the some magnetic piece 20 and 21 in the position which mutually shifted along the extension direction of these end surfaces 30-33 while the end surfaces 30 and 31 surface-contact. The cutting step is a step of cutting the magnetic pieces 20 to 22 to create the peripheral portion of the magnetic sheet 100.

  Hereinafter, this method will be described more specifically. In this method, the order and timing which perform a piece creation process, an arrangement | positioning process, and a cutting process are arbitrary. The order of the plurality of steps can be changed within a range that does not hinder the contents, and some or all of the execution timings of the plurality of steps may overlap each other.

  In the piece creation process, after firing the magnetic green sheet, it is cut using a press machine or a mold to produce a large number of magnetic pieces 20 and 21 having the same shape. The magnetic green sheet is an unfired sheet in which magnetic powder is dispersed in a binder resin and stretched. In the piece creation process, the tip edge 51 of the convex portion 50 and the tip edge 45 of the extended portion 44 of the magnetic pieces 20 and 21 cut on the individual pieces are chamfered by polishing.

  In the arrangement step, as shown in FIG. 6, the magnetic pieces 20 and 21 are arranged on the upper surface of the pressure-sensitive adhesive sheet 10 so that the orientations of the magnetic pieces 20 and 21 are staggered vertically and horizontally, and the concave portion 40 and the convex portion 50 are fitted. . The upper surface of the pressure-sensitive adhesive sheet 10 is subjected to pressure-sensitive adhesive processing, and the magnetic pieces 20 and 21 are detachably attached to the pressure-sensitive adhesive sheet 10. The magnetic pieces 20 and 21 may be disposed on the single-sided pressure-sensitive adhesive sheet 10 that has been cut into the magnetic sheet 100 in a desired shape and size in advance. Alternatively, a long pressure-sensitive adhesive sheet 10 such as a roll sheet is prepared, and the arrangement area of the magnetic pieces 20 and 21 is formed in a multifaceted manner over a plurality of positions on the adhesive sheet 10, and is formed into a desired shape and size in a cutting process described later. The magnetic sheet 100 may be created by cutting out.

  In the cutting process, the pressure-sensitive adhesive sheet 10 and the magnetic pieces 20 and 21 are cut along the cut line CL using a dicer. The convex portions 50 of the magnetic pieces 20 and 21 are cut. Then, the cut convex part 50 is peeled from the adhesive sheet 10, and it arrange | positions inside the concave part 40 as the replenishment piece 24 (refer Fig.1 (a)). In this way, the arrangement region of the magnetic pieces 20 and 21 is formed into a rectangle. Further, the molten resin is supplied so as to border the outer periphery of the magnetic pieces 20, 21, and this is cured to create the frame member 60.

  As described above, the magnetic sheet 100 of the present embodiment is created. The manufacturing method described above is created individually in a placement step of arranging magnetic pieces after cutting the fired magnetic green sheet and creating individual magnetic pieces in the piece creation step of creating magnetic pieces. The magnetic pieces are arranged. As a modification thereof, in the piece creation process, after cutting an unfired magnetic green sheet into a shape corresponding to the magnetic pieces 20 and 21, the cut magnetic green sheet is fired to create the magnetic pieces 20 and 21. May be.

  Moreover, you may perform a piece creation process and an arrangement | positioning process simultaneously. That is, by cutting the fired plate-like magnetic body and creating a plurality of magnetic pieces 20 and 21 so as to satisfy both the above conditions (A) and (B), the piece creation step and the placement step are performed. You may carry out simultaneously. Here, performing the piece creation process and the arrangement process at the same time means that at least a part of the execution timing of both processes overlaps in time.

<Second embodiment>
FIG. 7A is a schematic plan view showing the magnetic sheet 100 of this embodiment, and FIG. 7B is an explanatory view showing the piece group 70. In the magnetic sheet 100 of the present embodiment, the magnetic pieces 20 to 22 have a rectangular shape having a long side 34 and a short side 35, and the adjacent magnetic pieces 20 to 22 intersect the direction of the long side 34. It differs from the first embodiment in that it is arranged. For the sake of explanation, some of the magnetic pieces 20 to 22 in FIG.

  The magnetic pieces 20 to 22 are made of a rectangular plate having a predetermined thickness. The side peripheral surfaces of the magnetic pieces 20 to 22 are composed of a long side surface corresponding to the long side 34 and a short side surface corresponding to the short side 35. Hereinafter, the long side surface corresponding to the long side 34 is referred to as an end surface 30 of the present embodiment, and the short side surface corresponding to the short side 35 is referred to as an end surface 31.

Then, the magnetic sheet 100 of this embodiment has a plurality of magnetic pieces 20 and 21 arranged in a plane, and satisfies the following conditions (A) and (B) together with the first embodiment. It will be common.
(A) The end surface 30 of the adjacent magnetic piece 20 and the end surface 31 of the magnetic piece 21 are in surface contact with each other.
(B) Adjacent magnetic pieces 20 and 21 are arranged at positions shifted from each other along the extending direction of the end faces 30 and 31 (X direction in FIGS. 7A and 7B) in contact with each other.

  As a result, even if the magnetic sheet 100 is curved in the extending direction (X direction) of the end surfaces 30 and 31 that are in surface contact, the bending occurs in the plane of the end surfaces 30 and 31. Surface contact between 20 and 21 is maintained. For this reason, even if the magnetic sheet 100 curves in the said direction, a magnetic characteristic does not deteriorate significantly.

  The center of gravity of the second magnetic piece 21 shown in FIG. 7A is different from the center of gravity of the first magnetic piece 20 in both the X direction and the Y direction. That is, the first magnetic piece 20 and the second magnetic piece 21 are arranged at positions shifted from each other in both the X direction and the Y direction. Similarly, the first magnetic piece 20 and the third magnetic piece 22 are arranged at positions shifted from each other in both the X direction and the Y direction. In addition, the shape and arrangement | positioning direction of the 2nd magnetic piece 21 and the 3rd magnetic piece 22 are common, and both are distinguished for convenience.

The second embodiment is common to the first embodiment in the following points.
First, the magnetic piece 20 (first magnetic piece) has first and second end faces 30 and 31 whose extending directions intersect each other.
The first end face 30 is in surface contact with the end face 31 of the adjacent magnetic piece 21 (second magnetic piece), and the first magnetic piece 20 and the second magnetic piece 21 are The magnetic pieces 20 are arranged at positions shifted from each other along the extending direction (X direction) of the first end face 30.
Further, the second end face 31 of the first magnetic piece 20 is in surface contact with the end face 30 of the adjacent third magnetic piece 22, and the first magnetic piece 20 and the third magnetic piece 22 are The first magnetic piece 20 is disposed at a position shifted from each other along the extending direction (Y direction) of the second end face 32 of the first magnetic piece 20.

  For this reason, the magnetic sheet 100 of the second embodiment also has a state in which the magnetic pieces 20 to 22 are in surface contact with each other with respect to any curvature in the X direction and the Y direction, and the combined direction of the X direction and the Y direction. Can be maintained.

  In the magnetic sheet 100 of the present embodiment, with reference to at least one of the adjacent magnetic pieces (for example, the magnetic piece 20) as a reference, a partial region of the end face of the magnetic piece is separated from another adjacent magnetic piece (the magnetic piece 21). ) And partially share. In other words, in the planar view shape of the magnetic sheet 100, the magnetic pieces 20, 21 adjacent to each other share a ridge line extending in a predetermined direction, and the magnetic pieces 20, 21 are in a direction orthogonal to the ridge line. Are displaced from each other.

A piece group 70 shown in FIG. 7B is a cluster composed of a plurality (four in the drawing) of magnetic pieces 20 and 21. The magnetic sheet 100 of this embodiment shown in FIG. 7A is formed by arranging the piece groups 70 in the same direction.
In manufacturing the magnetic sheet 100 of the present embodiment, by creating the piece group 70 in advance, it is possible to easily create the magnetic sheet 100 simply by arranging the piece group 70 in the same direction on the adhesive sheet 10 without a gap. Can do. The piece group 70 may be arranged side by side on the adhesive sheet 10 in a state where the magnetic pieces 20 and 21 constituting the piece group 70 are temporarily fastened so as to be easily broken.

  The various components of the magnetic sheet of the present invention do not have to be individually independent, but a plurality of components are formed as one member, and one component is formed of a plurality of members. A certain constituent element is a part of another constituent element, a part of a certain constituent element and a part of another constituent element are allowed to overlap.

The above embodiment includes the following technical idea.
(1) A magnetic sheet comprising a plurality of magnetic pieces arranged side by side and satisfying the following conditions (A) and (B):
(A) The end faces of the adjacent magnetic pieces are in surface contact with each other.
(B) The adjacent magnetic pieces are arranged at positions shifted from each other along the extending direction of the end face in surface contact.
(2) The first magnetic piece has first and second end surfaces whose extending directions intersect with each other, and the first end surface is mutually connected to an end surface of the adjacent second magnetic piece. The first and second magnetic pieces are in contact with each other, and are disposed at positions shifted from each other along the extending direction of the first end face, and the second end face is adjacent to the first end piece. The end surfaces of the three magnetic pieces are in surface contact with each other, and the first and third magnetic pieces are disposed at positions shifted from each other along the extending direction of the second end surface ( The magnetic sheet according to 1).
(3) At least one of the magnetic pieces located on an arbitrary line segment extending in the direction in which the magnetic pieces are arranged, and another magnetic piece adjacent to the one magnetic piece are the above (A) and ( The magnetic sheet according to (1) or (2), wherein both of the conditions of B) are satisfied.
(4) The magnetic sheet according to any one of (1) to (3), wherein the adjacent magnetic pieces have the same shape.
(5) The magnetic piece has a concave portion and a convex portion, and the convex portion is fitted with the concave portion of another adjacent magnetic piece, and an end surface having a protruding direction as an extending direction among the convex portions; The magnetic sheet according to any one of (1) to (4), wherein an end surface having a concave direction as an extending direction among the concave portions is in surface contact with each other.
(6) At least one of the leading edge of the convex portion or the deepest edge of the concave portion is chamfered, and is configured so as not to interfere with the other of the leading edge or the deepest edge when the magnetic sheet is curved. ) Magnetic sheet.
(7) The magnetic sheet according to any one of (1) to (6), further including an adhesive sheet for attaching and fixing a plurality of the magnetic pieces on the surface.
(8) The magnetic sheet according to any one of (1) to (7), further including a flexible frame member surrounding a periphery of the magnetic piece.
(9) The magnetic sheet according to any one of (1) to (8), a coil having a thickness direction of the magnetic sheet as a winding axis direction, and a circuit board that supplies an alternating current to the coil. Electronics.
(10) A method of manufacturing a magnetic sheet in which a plurality of magnetic pieces are arranged side by side, wherein a plurality of magnetic pieces having the same shape are formed, and the plurality of magnetic pieces are connected to each other between end surfaces. And a step of arranging at positions shifted from each other along the extending direction of the end surface, and a step of cutting the magnetic piece to create a peripheral portion of the magnetic sheet. Method.
(11) The magnetic piece is in a rectangular shape having a long side and a short side, and the adjacent magnetic pieces are arranged so as to intersect with the direction of the long side. The magnetic sheet as described.
(12) The magnetic sheet according to the above (11), wherein pieces of a plurality of magnetic pieces are arranged side by side in the same direction.
(13) In the step of creating the magnetic piece, after cutting the fired magnetic green sheet to individually create the magnetic piece, the step of placing the magnetic piece in the step of arranging the magnetic piece The method for producing a magnetic sheet according to (10), wherein the magnetic sheet is arranged.
(14) In the step of creating the magnetic piece, after cutting an unfired magnetic green sheet into a shape corresponding to the magnetic piece, the cut magnetic green sheet is fired to create the magnetic piece. The method for producing a magnetic sheet according to (10), which is characterized in that
(15) cutting the fired plate-like magnetic body to create the plurality of magnetic pieces so as to satisfy both of the conditions (A) and (B), thereby creating the magnetic pieces; The method for producing a magnetic sheet according to (10), wherein the step of arranging the magnetic pieces is performed simultaneously.

10: Adhesive sheet, 20-22: Magnetic piece, 24: Replenishment piece, 30-33: End face, 34: Long side, 35: Short side, 40: Recessed part, 41: Deepest edge, 42: Center part, 44: Extension Protruding part, 45: tip edge, 50: convex part, 51: tip edge, 60: frame member, 70: piece group, 80-83: side, 100: magnetic sheet, 120: electronic device, 130: protective sheet, 140 : Coil, 150: Circuit board, 152: Power supply terminal, 154: Wiring, 200: Magnetic sheet, 210: Base material, 220, 221: Magnetic piece, 230, 231: End face, 240: Gap, θ: Bending angle, μ _e : Effective magnetic permeability, CL: Cut line, L1, L2: Line segment

Claims (10)

A magnetic sheet comprising a plurality of magnetic pieces arranged side by side and satisfying the following conditions (A) and (B):
(A) The end faces of the adjacent magnetic pieces are in surface contact with each other.
(B) The adjacent magnetic pieces are arranged at positions shifted from each other along the extending direction of the end face in surface contact. The first magnetic piece has first and second end faces whose extending directions intersect each other,
The first end face is in surface contact with the end face of the adjacent second magnetic piece, and the first and second magnetic pieces are displaced from each other along the extending direction of the first end face. It is placed in the matching position,
The second end face is in surface contact with the end face of the adjacent third magnetic piece, and the first and third magnetic pieces are displaced from each other along the extending direction of the second end face. The magnetic sheet according to claim 1, wherein the magnetic sheet is disposed at a matching position.   At least one of the magnetic pieces located on an arbitrary line segment extending in the direction in which the magnetic pieces are arranged, and another magnetic piece adjacent to the one magnetic piece are the above (A) and (B). The magnetic sheet according to claim 1, wherein both conditions are satisfied.   The magnetic sheet according to claim 1, wherein the adjacent magnetic pieces have the same shape. The magnetic piece has a concave portion and a convex portion;
The convex portion is fitted with the concave portion of another adjacent magnetic piece,
The magnetic surface according to any one of claims 1 to 4, wherein an end surface of the convex portion having a protruding direction as an extending direction and an end surface of the concave portion having a concave direction as an extending direction are in surface contact with each other. Sheet.   6. The configuration according to claim 5, wherein at least one of a leading edge of the convex portion or a deepest edge of the concave portion is chamfered so as not to interfere with the other of the leading edge or the deepest edge when the magnetic sheet is curved. Magnetic sheet.   The magnetic sheet according to any one of claims 1 to 6, further comprising an adhesive sheet that adheres and fixes a plurality of the magnetic pieces to the surface.   The magnetic sheet according to any one of claims 1 to 7, further comprising a flexible frame member surrounding a periphery of the magnetic piece.   An electronic device comprising: the magnetic sheet according to claim 1; a coil having a thickness direction of the magnetic sheet as a winding axis direction; and a circuit board that supplies an alternating current to the coil. A method for producing a magnetic sheet in which a plurality of magnetic pieces are arranged in a plane,
Creating a plurality of the magnetic pieces having the same shape;
Arranging a plurality of the magnetic pieces at positions shifted from each other along the extending direction of the end faces while the end faces are in surface contact with each other;
Cutting the magnetic piece to create a peripheral portion of the magnetic sheet.

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