JP5903568B2 - Non-contact charging module and non-contact charging device - Google Patents

Description

  The present invention relates to a non-contact charging module and a non-contact charging device having a planar coil portion and a magnetic sheet.

  In recent years, many devices that can charge the main device in a non-contact manner with a charger have been used. In this method, a power transmission coil is arranged on the charger side, a power reception coil is arranged on the main device side, and electromagnetic induction is generated between the two coils to transmit power from the charger side to the main device side. It has also been proposed to apply a mobile terminal device or the like as the main device.

  The main device such as the portable terminal device and the charger are required to be thin and small. In order to meet this demand, it is conceivable to provide a planar coil portion as a power transmission coil or a power reception coil and a magnetic sheet as in (Patent Document 1).

JP 2006-42519 A

  However, in the non-contact charging module having a flat coil portion of one conductor and a magnetic sheet having a flat surface as in (Patent Document 1), the winding start or winding end of the coil is located inside the coil. May end up. In that case, although there may be a case where a plurality of conducting wires are used, a portion where the coil is wound and a portion between the coil winding start or winding end and the terminal overlap in the thickness direction. As a result, the non-contact charging module cannot be thinned.

  Also, some magnetic sheets are conductive, and in that case, insulation between the conductor and the magnetic sheet is important.

  Then, in view of said problem, this invention aims at achieving thickness reduction in the state which ensured the insulation with a conducting wire and a magnetic sheet.

  In order to solve the above-described problems, the present invention provides a planar coil portion around which a conducting wire is wound and the planar coil portion, and an insulating sheet is disposed on the coil surface on the side where the planar coil portion is disposed. A Mn-Zn ferrite sheet provided so as to oppose, and a recess or slit provided on the Mn-Zn ferrite sheet and extending from the winding start point of the coil surface to the end of the magnetic sheet. A conductor of the planar coil portion is housed in the recess or slit by pushing the insulating sheet into the recess or slit, and the conductor of the planar coil portion is the Mn-Zn ferrite sheet by the insulating sheet. It was set as the non-contact charge module characterized by being insulated from.

  According to the present invention, it is possible to achieve a reduction in thickness in a state where insulation between the conductive wire and the magnetic sheet is ensured.

Assembly drawing of the non-contact charging module in the embodiment of the present invention The conceptual diagram of the non-contact charge module in embodiment of this invention The conceptual diagram of the magnetic sheet of the non-contact charge module in embodiment of this invention The figure of the magnetic sheet and flat coil part which formed the recessed part in embodiment of this invention The expanded sectional view of the magnetic sheet and flat coil part which formed the slit in embodiment of this invention Sectional drawing of the magnetic sheet and flat coil part which formed the slit in embodiment of this invention

  According to the first aspect of the present invention, the planar coil portion on which the conducting wire is wound and the planar coil portion are placed, and the coil surface on the side on which the planar coil portion is placed is opposed to the coil surface via an insulating sheet. A Mn-Zn-based ferrite sheet provided as described above, and a recess or slit provided in the Mn-Zn-based ferrite sheet and extending from the winding start point of the coil surface to the end of the magnetic sheet, The conductor of the planar coil part is housed in the recess or slit by pushing the insulating sheet into the recess or slit, and the conductor of the planar coil part is insulated from the Mn-Zn ferrite sheet by the insulating sheet. The non-contact charging module is characterized in that the thinning can be achieved in a state where the insulation between the conducting wire and the magnetic sheet is ensured.

  The invention according to claim 2 is the non-contact charging module according to claim 1, wherein the width of the recess or the slit is three times or more the wire diameter of the conductor. Is housed in the recess due to the stretchability of the insulating sheet, so that the thinning can be achieved while ensuring the insulation between the conductor and the magnetic sheet.

  The invention according to claim 3 is the non-contact charging module according to claim 1, wherein a wire diameter of the conducting wire is smaller than 0.3 mm, and a thickness of the insulating sheet is 5 to 20 μm. Since the conductive wire is reliably accommodated in the recess due to the stretchability of the insulating sheet, the thinning can be achieved while the insulation between the conductive wire and the magnetic sheet is ensured.

  According to a fourth aspect of the present invention, there is provided a non-contact charging module according to the first aspect, wherein a through-hole smaller than the wire diameter of the conducting wire is formed in a portion of the insulating sheet facing the recess or slit. Even when the insulation sheet is not stretchable enough, the conductor is securely stored in the recess due to the elasticity of the insulation sheet, so that the insulation between the conductor and the magnetic sheet is ensured and thin. Can be achieved.

  A fifth aspect of the present invention is a non-contact charging device comprising the non-contact charging module according to any one of the first to fourth aspects, wherein insulation between the conductor and the magnetic sheet is ensured. In this state, it is possible to reduce the thickness.

(Embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an assembly diagram of a contactless charging module according to an embodiment of the present invention, FIG. 2 is a conceptual diagram of the contactless charging module according to an embodiment of the present invention, (a) is a top view, and (b). Fig. 2 is a cross-sectional view seen from the A direction in Fig. 2A, and Fig. 2C and Fig. 3D are cross-sectional views seen from the B direction in Fig. 2A. FIG. 3 is a conceptual diagram of a magnetic sheet of a contactless charging module according to an embodiment of the present invention, (a) is a top view, (b) is a cross-sectional view as viewed from the A direction in FIG. (c) And (d) is sectional drawing seen from the B direction of Fig.3 (a).

  The non-contact charging module 1 of the present invention includes a planar coil portion 2 in which a conductive wire is wound in a spiral shape, and a magnetic sheet 3 provided so as to face the surface of the coil 21 of the planar coil portion 2.

  As shown in FIG. 1A, the planar coil unit 2 includes a coil 21 wound with a conductor in a radial direction so as to draw a vortex on the surface, and terminals 22 and 23 provided at both ends of the coil 21. Prepare. The coil 21 is obtained by winding a conductive wire in parallel on a plane, and a surface formed by the coil is called a coil surface. In addition, the thickness direction is a stacking direction of the planar coil portion 2 and the magnetic sheet 3. In the present embodiment, the coil 21 is wound outward from an inner diameter of 20 mm in diameter, and the outer diameter is 30 mm. That is, the coil 21 is wound in a donut shape. The coil 21 may be wound in a circular shape or may be wound in a polygonal shape.

  In addition, since the conducting wires are wound so as to leave a space between each other, the stray capacitance between the upper conducting wire and the lower conducting wire is reduced, and the AC resistance of the coil 21 can be kept small. Moreover, the thickness of the coil 21 can be suppressed by winding so that space may be packed.

  Further, in the present embodiment as shown in FIG. 3, the cross-sectional area is a circular conducting wire, but a conducting wire having a square shape or the like may be used. However, in the case of a circular conductor compared with a rectangular conductor, a gap is formed between adjacent conductors, so that the stray capacitance between the conductors is reduced, and the AC resistance of the coil 21 is reduced. Can do.

  In addition, the coil 21 is wound in one stage rather than being wound in two stages in the thickness direction, so that the alternating current resistance of the coil 21 is lowered and transmission efficiency can be increased. This is because when a conducting wire is wound in two stages, stray capacitance is generated between the upper conducting wire and the lower conducting wire. Therefore, it is better to wind as many portions as possible in one stage, rather than winding the entire coil 21 in two stages. Moreover, it can reduce in thickness as the non-contact charge module 1 by winding in 1 step | paragraph. In addition, the loss in the coil 21 is prevented because the alternating current resistance of the coil 21 is low, and the power transmission efficiency of the contactless charging module 1 depending on the L value can be improved by improving the L value.

  Moreover, in this Embodiment, the inner diameter x inside the coil 21 shown in FIG. 1 is 10 mm-20 mm, and an outer diameter is about 30 mm. As the inner diameter x is smaller, the number of turns of the coil 21 can be increased in the contactless charging module 1 of the same size, and the L value can be improved.

  In addition, although the terminals 22 and 23 may be close to each other or may be arranged apart from each other, the non-contact charging module 1 is easier to mount if they are arranged apart.

The magnetic sheet 3 is provided in order to improve the power transmission efficiency of non-contact charging using electromagnetic induction action, and corresponds to the flat portion 31 and the inner diameter of the coil 21 at the center as shown in FIG. The center part 32 and the recessed part 33 are provided. In addition, as shown in FIG. 3, the center part 32 does not necessarily need to be convex. The recess 33 may be a slit 34, and the recess 33 or the slit 34 is not necessarily required. However, as shown in FIGS. 2 (c) and 2 (d), by providing the recess 33 or the slit 34, the conductive wire from the winding end of the coil 21 to the terminal 23 can be accommodated in the recess 33 or the slit 34. Therefore, it can be made thinner. That is, the concave portion 33 or the slit 34 is formed so as to be substantially perpendicular to the end portion of the magnetic sheet 3 and overlap with the tangent line on the outer periphery of the central portion 32. By forming the recess 33 or the slit 34 in this way, the terminals 22 and 23 can be formed without bending the conducting wire. In this case, the length of the recess 33 or the slit 34 is about 15
mm to 20 mm. However, the length of the recess 33 or the slit 34 depends on the inner diameter of the coil 21. Further, the concave portion 33 or the slit 34 may be formed in a portion where the end of the magnetic sheet 3 and the outer periphery of the central portion 32 are closest. Thereby, the formation area of the recessed part 33 or the slit 34 can be suppressed to the minimum, and the transmission efficiency of the non-contact charging module 1 can be improved. In this case, the length of the recess 33 or the slit 34 is about 5 mm to 10 mm. In either arrangement, the inner end of the recess 33 or the slit 34 is connected to the center 32. Moreover, you may make the recessed part 33 or the slit 34 into another arrangement | positioning. That is, it is desirable that the coil 21 has a one-stage structure as much as possible. In that case, all the turns in the radial direction of the coil 21 are made into a one-stage structure, or one part is made into a one-stage structure and the other part is made into a two-stage structure. It is possible to do. Therefore, one of the terminals 22 and 23 can be pulled out from the outer periphery of the coil 21, but the other must be pulled out from the inside. Accordingly, the portion around which the coil 21 is wound and the foot portion 24 always overlap in the thickness direction. Accordingly, the concave portion 33 or the slit 34 may be provided in the overlapping portion, and the foot portion 24 may be accommodated therein. The foot portion 24 refers to a portion from the end of winding of the coil 21 to the terminal 22 or 23. If it is the recessed part 33, since a through-hole and a slit are not provided in the magnetic sheet 3, it can prevent that a magnetic flux leaks and can improve the electric power transmission efficiency of the non-contact charge module 1. FIG. On the other hand, in the case of the slit 34, the magnetic sheet 3 can be easily formed. When it is the recessed part 33, as shown in FIG.4 (c), it is not limited to the recessed part 33 in which a cross-sectional shape becomes a square shape, You may form circular arc shape or roundness.

  In the present embodiment, a Ni—Zn ferrite sheet, a Mn—Zn ferrite sheet, a Mg—Zn ferrite sheet, or the like can be used as the magnetic sheet 3. The ferrite sheet can reduce the AC resistance of the coil 21 as compared with the amorphous metal magnetic sheet.

  As shown in FIG. 3, the magnetic sheet 3 has at least a high saturation magnetic flux density material 3a and a high magnetic permeability material 3b laminated. Even when the high saturation magnetic flux density material 3a and the high magnetic permeability material 3b are not laminated, it is preferable to use the high saturation magnetic flux density material 3a having a saturation magnetic flux density of 350 mT or more and a thickness of at least 300 μm.

  It is desirable that the coil 21 has a one-stage structure as much as possible. In that case, all the turns in the radial direction of the coil should be a one-stage structure, or a part may be a one-stage structure and the other part a two-stage structure. Conceivable. Therefore, one of the terminals 22 and 23 can be pulled out from the outer periphery of the coil 21, but the other must be pulled out from the inside. Accordingly, the portion around which the coil 21 is wound and the foot portion 24 always overlap in the thickness direction.

Accordingly, in the present invention, the concave portion 33 or the slit 34 is provided linearly in the overlapping portion. In particular, a linear recess 33 or slit that is parallel to the tangential line of the inner circumference of the coil 21 surface and extends at the shortest distance from the start or end of winding of the coil surface to the end of the magnetic sheet 3. 34. The concave tangent 33 or the slit 34 extends from the vicinity of the outer periphery of the inner peripheral circle of the coil 21 surface, and the concave portion 33 or the slit 34 is the inner periphery of the coil 21 surface. It is the tangent of the circumference of the inner circumference circle at a location approaching the outer circumference of the circle. By forming the straight portion 33b in this way, the terminals 22 and 23 can be formed without bending the conducting wire on the magnetic sheet 3. That is, in order to provide the concave portion 33 or the slit 34 and insert the conductive wire into the concave portion 33 or the slit 34, the conductive wire must be refracted in the thickness direction from the flat portion 31 toward the concave portion 33 or the slit 34. Therefore, since the conducting wire is not bent on the magnetic sheet 3 in the portion where the conducting wire is fitted from the flat portion 31 toward the recess 33 or the slit 34, it is possible to achieve a reduction in thickness while maintaining the strength of the conducting wire. In this case, the length of the straight portion 33b is about 15 mm to 20 mm. The coil 21 may be wound in a polygonal shape. In this case, the coil 21 is parallel to the shape of the space formed by the inner end of the surface of the coil 21 or the tangent line thereof, and is the point at which the coil surface starts or ends. It is preferable to provide the recess 33 or the slit 34 in a straight line extending at the shortest distance from to the end of the magnetic sheet 3.

  In addition, the magnetic sheet 3 has a recess 33 that is perpendicular to the tangent to the inner circumference of the coil 21 surface and extends at the shortest distance from the start or end of winding of the coil surface to the end of the magnetic sheet 3. Alternatively, the slit 34 may be formed. Thereby, the formation area of the recessed part 33 or a slit can be suppressed to the minimum, and the transmission efficiency of the non-contact charge module 1 can be improved. That is, by providing the concave portion 33 or the slit 34, a part of the magnetic sheet 3 is missing or thinned. Therefore, the magnetic flux leaks from the recess 33 or the slit 34, and the power transmission efficiency of the non-contact charging module may be somewhat reduced. Therefore, by reducing the formation area of the recess 33 to the minimum, it is possible to reduce the thickness while minimizing the leakage of magnetic flux and maintaining the power transmission efficiency of the non-contact charging device. In this case, the length of the straight portion 33b is about 5 mm to 10 mm. In addition, on the tangent line of the outer periphery of the center portion 32, the shape is parallel to the end portion 3 a of the magnetic sheet 3 in order to provide the shortest distance to the end portion of the magnetic sheet 3. Note that the coil 21 may be wound in a polygonal shape, and in that case, the coil 21 may be perpendicular to the shape of the space formed by the inner end of the surface of the coil 21 or its tangent line. The concave portion 33 or the slit 34 may be provided in a straight line extending from the end point to the end of the magnetic sheet 3 at the shortest distance.

  2 and 3 are parallel to one pair of opposing end sides of the rectangular magnetic sheet 3 and perpendicular to the other pair of opposing end sides. This is because the magnetic sheet 3 of the present embodiment is square. However, the shape of the magnetic sheet 3 is not limited to a square, and various shapes such as a circle and a polygon can be considered. Therefore, for example, the shape of the magnetic sheet 3 is polygonal, and the concave portion 33 or the slit 34 is perpendicular to the side against which one end of the concave portion 33 or the slit 34 abuts. The area of 33 or the slit 34 can be minimized. In particular, the shape of the magnetic sheet 3 is square, parallel to one pair of opposing end sides of the magnetic sheet 3 and perpendicular to the other pair of opposing end sides, In the rectangular magnetic sheet that is easy to use, the area of the recess 33 or the slit 34 can be minimized.

  From the above, the concave portion 33 or the slit 34 is provided in a portion where the coil 21 and the foot portion 24 overlap each other, and the surface of the coil 21 is provided on the flat portion 31. The concave portion 33 or the slit 34 may be provided to be somewhat longer or shorter, but it is preferable that at least 80% or more of the portion where the coil 21 and the foot portion 24 overlap can be covered.

  2 and 3, the magnetic sheet 3 is about 33 mm × 33 mm. The thickness d1 of the center part 32 shown in FIG.2 (c) is 0.2 mm. In addition, d2 shown in FIG. 3C is the thickness of the magnetic sheet 3, which is 0.6 mm, d3 is 0.15 mm, and d4 is 0.45 mm. The thicknesses of the high magnetic permeability materials 3b are set and laminated.

  Next, in the case where the magnetic sheet 3 is conductive, the insulation between the magnetic sheet 3 and the planar coil portion 2 will be described. First, the case where the recessed part 33 is provided is demonstrated. It should be noted that the magnetic sheet 3 does not need to be conductive in all parts of the magnetic sheet 3. For example, in FIGS. 3 (c) and 3 (d), 3 a is a conductive sheet and 3 b is non-conductive. The case where at least a part of the magnetic sheet 3 is conductive so as to be a conductive sheet is also included.

4A and 4B are diagrams of the magnetic sheet and the planar coil portion in which the concave portion is formed according to the embodiment of the present invention. FIG. 4A is a cross-sectional view of the concave portion of the magnetic sheet, and FIG. 4C is a cross-sectional view of the magnetic sheet and the insulating sheet after bonding, and FIG. 4D is a cross-sectional view of the foot of the insulating sheet and the coil. These cross-sectional views are cross-sectional views taken along the line CC of the recess in FIG.

  In the present embodiment, since the magnetic sheet 3 is conductive, the side wall 33a and the bottom surface 33c of the recess 33 are also conductive. Therefore, the conducting wire and its foot 24 should not contact either the side wall 33a or the bottom surface 33c of the recess 33. Therefore, the insulating sheet 4 is bonded to at least the coil 21 side of the magnetic sheet 3. Then, the planar coil portion 2 is placed on the insulating sheet 4. At this time, the foot 24 is housed in the recess 33 by pushing down the insulating sheet 4 corresponding to the recess 33 downward. By doing so, the foot 24 can be brought into contact with the coil 21 and stored in the recess 33.

  In the present embodiment, base materials PET, PEN, acrylic, and polyester are conceivable for acrylic and silicone adhesives. The dimensional expansion / contraction rate is preferably 0.05% to 0.1%. The dimension expansion / contraction rate is expressed by (length after processing−length before processing) / length before processing, and the processing means that the insulating sheet 4 is extended by the feet 24.

  Moreover, when setting it as such a form, it is preferable that the wire diameter of a conducting wire is about 0.3 mm.

  In addition, in order to evacuate the air between the recessed part 33 and the insulating sheet 4 and to increase the contractibility of the insulating sheet 4, a small hole may be formed. When making a small hole, the size of the hole is preferably 200 μm or more. Moreover, it is better to be closer to the center side end of the recess 33 or the slit 34, and it is preferable to make a hole in the range of the center side ½ of the slit length.

  In the present embodiment, the slit width Da1 is 1.34 mm, the thickness Db1 of the magnetic sheet 3 is 0.6 mm, the wire diameter Dc of the conducting wire is 0.25 mm, and the depth Dd1 of the recess 33 is 0.3 mm. . In this case, since the wire diameter Dc1 (0.25 mm) of the conducting wire is relatively small with respect to the thickness Db1 (0.6 mm) of the magnetic sheet 3, the magnetic sheet 3 is provided with a recess 33 instead of the slit 34. By using the recesses 33 instead of the slits 34, the magnetic field can be prevented from leaking from the magnetic sheet 3 during power transmission. Thus, it is desirable to form the recess 33 if the wire diameter Dc of the conducting wire is less than 75% of the thickness Db1 of the magnetic sheet 3. The wire diameter Dc of the conducting wire is preferably smaller than 50% of the thickness Db1 of the magnetic sheet 3. Moreover, it is preferable that the width Da1 of a slit is 3 times or more of the wire diameter Dc1 of conducting wire. Since the width Da1 of the slit is three times or more the wire diameter Dc1 of the conducting wire, the insulating sheet 4 can sufficiently accommodate the foot portion 24 in the recess 33.

  In this way, the conducting wire is accommodated in the first slit 34 via the insulating sheet 4.

  Such a structure is particularly useful for a secondary side non-contact charging module which is a receiving side. That is, in the secondary side non-contact charging module, since the voltage of the current flowing through the coil and the value of the current are relatively small, a thin conductive wire with a wire diameter of 0.25 mm is sufficient. On the other hand, since the housing of the secondary side non-contact charging module itself is desired to be downsized, the distance between the metal closest to the planar coil unit 2 and the planar coil unit 2 is smaller than that of the primary side non-contact charging module. And very close. Therefore, in order to sufficiently prevent the influence of metal, the magnetic sheet 3 becomes thicker than the primary side non-contact charging module. As a result, since the wire diameter of the conducting wire is smaller than that of the primary side non-contact charging module and the thickness of the magnetic sheet 3 is thick, the concave portion 33 is often formed in the magnetic sheet 3. In the case of the concave portion 33, when the conductive wire is pushed into the concave portion 33, the bottom surface 33c of the concave portion 33 exists under the conductive wire. Further, since the insulating sheet 4 is provided with the slits 41, the insulating sheet 4 needs to be stretchable. In the present embodiment, the insulating sheet 4 is set to be as thin as 10 μm, and preferably 5 to 20 μm or less.

  That is, a flat coil portion in which a conducting wire is wound in a spiral shape, a magnetic sheet provided so as to face the coil surface via an insulating sheet, and a magnetic sheet provided at the beginning or end of winding of the coil surface A recess or slit extending from the point to the end of the magnetic sheet, wherein the magnetic sheet is electrically conductive at least part of the portion where the recess or slit is formed, and the conductive wire passes the insulating sheet into the recess or slit. Since it is pushed in and accommodated in the recess or slit, it is possible to achieve a reduction in thickness while ensuring insulation between the conductor and the magnetic sheet.

  In addition, since the width of the concave portion is three times or more the wire diameter of the conductive wire, the conductive wire is surely stored in the concave portion due to the stretchability of the insulating sheet, so that the insulation between the conductive wire and the magnetic sheet is ensured. Thinning can be achieved.

  In addition, since the wire diameter is smaller than 0.3 mm and the thickness of the insulating sheet is 5 to 20 μm, the conductive wire is reliably accommodated in the recess due to the stretchability of the insulating sheet, so that the insulation between the conductive wire and the magnetic sheet is possible. It is possible to achieve a reduction in thickness while ensuring the above.

  In addition, by opening a through-hole smaller than the wire diameter of the conductive wire in the portion facing the recess or slit of the insulating sheet, the conductive wire can be surely expanded and contracted even when the insulating sheet lacks elasticity. Therefore, thinning can be achieved in a state where insulation between the conductor and the magnetic sheet is ensured.

  Next, the case where the slit 34 is provided will be described. In the case of the slit 34, the same method as the above-described concave portion 33 may be used, or the slit 34 can be insulated by the method described below.

  FIG. 5 is an enlarged cross-sectional view of a magnetic sheet having a slit and a planar coil portion in the embodiment of the present invention. FIG. 6 is a cross-sectional view of a magnetic sheet having a slit and a planar coil portion in the embodiment of the present invention, and FIG. 6 (a) is a CC line when the concave portion of FIG. 3 (a) is a slit. FIG. 6B is a cross-sectional view taken along the line DD when the concave portion of FIG. 3A is a slit.

  The non-contact charging module 1 in the present embodiment includes a planar coil portion 2 in which a conducting wire is wound in a spiral shape, a magnetic sheet 3 provided so as to face the coil 21 surface via an insulating sheet 4, and a magnetic A first slit 34 provided on the sheet and extending from the beginning or end of winding of the coil surface to the end of the magnetic sheet 3, and the insulating sheet 4 corresponds to the first slit 34 ( A second slit 41 (cut) is provided at a position facing (opposite), and the foot portion 24 of the conducting wire is accommodated in the first slit 34 via the insulating sheet 4. In the present embodiment, insulating sheets are provided on both surfaces of the magnetic sheet 3, respectively.

  That is, if the magnetic sheet 3 is conductive, the magnetic sheet 3 and the conducting wire are electrically connected, and the non-contact charging module 1 does not function. Therefore, by providing the insulating sheet 4 between the planar coil portion 2 and the magnetic sheet 3, the planar coil portion 2 and the magnetic sheet 3 can be insulated. At this time, since the side wall 34a of the slit 34 is also conductive, if the conductive wire and the side wall 34a come into contact with each other, the non-contact charging module 1 will not function. Therefore, the insulating sheet 4 is provided with a second slit 41 at a position corresponding to (opposing to) the first slit 34. In FIG. 5, the adhesive sheet 5 is provided between the insulating sheet 4 and the conductor, and the adhesive sheet 5 can be bonded on both sides, so that the magnetic sheet 3 and the conductor can be fixed.

In the present embodiment, the slit width Da2 is 1.34 mm, the magnetic sheet 3 thickness Db2 is 0.46 mm, the wire diameter Dc2 is 0.35 mm, and the slit width Da2 (1.34 mm) is magnetic. It becomes twice or more the thickness Db2 (0.46 mm) of the sheet 3 and the wire diameter Dc2 (0.35 mm) of the conducting wire. That is, the thickness of the side wall 34a is the thickness Db2 (0.46 mm) of the magnetic sheet 3, and the side wall 34a exists on both the left and right sides of the conductive wire, so that the portion pushed into the slit 34 of the insulating sheet 4 is required to be twice or more. Because it becomes. Further, since the conducting wire must be accommodated in the slit 34, it is preferable that Da2> = 2 × Db2> = 2 × Da2. Moreover, it is preferable that the width Da1 of a slit is 3 times or more of the wire diameter Dc1 of conducting wire.

  In this way, the conducting wire is accommodated in the first slit 34 via the insulating sheet 4.

  Such a structure is particularly useful for a primary side non-contact charging module which is a transmitting side. That is, in the primary side non-contact charging module, since the voltage of the current flowing through the coil and the value of the current are large, the conductive wire is as thick as 0.35 mm. On the other hand, since the housing of the primary side non-contact charging module is large, the distance between the metal closest to the planar coil unit 2 and the planar coil unit 2 is larger than that of the secondary side non-contact charging module. Therefore, the magnetic sheet 3 becomes thinner compared to the secondary side non-contact charging module. As a result, the wire diameter of the conducting wire is larger than that of the secondary-side non-contact charging module, and the thickness of the magnetic sheet 3 is thin, so that the slit 34 is often formed in the magnetic sheet 3. In the case of the slit 34, the bottom surface of the magnetic sheet 3 does not exist below the conductor even when the conductor is pushed into the slit 34 as compared with the case where the recess is formed (in this embodiment, the insulation in which the slit 41 is formed). An insulating sheet 4 different from the sheet 4 is adhered). In addition, since the insulating sheet 4 is provided with the slit 41 and does not need to be stretchable, in this embodiment, the insulating sheet 4 is set to be as thick as 30 μm, and preferably 20 μm to 50 μm so that the strength does not decrease even if the slit is formed. Further, the insulating sheet 4 is preferably made of an acrylic or silicone adhesive with a base material PET, PEN, acrylic or polyester. The wire diameter of the conducting wire is smaller than the thickness of the magnetic sheet.

  As described above, the planar coil portion in which the conductive wire is wound in a spiral shape, the magnetic sheet provided so as to face the coil surface via the insulating sheet, the magnetic sheet, the winding start of the coil surface or A first slit extending from the end of winding to the end of the magnetic sheet, and at least part of the portion of the magnetic sheet in which the first slit is formed is conductive, and the insulating sheet includes a first slit. The second slit is provided at a position corresponding to the slit, and the conductive wire is accommodated in the first slit via the insulating sheet, so that the insulation between the conductive wire and the magnetic sheet is ensured and the thickness is reduced. Can be achieved.

  In addition, since the width of the recess is more than twice the diameter of the conducting wire, the insulating sheet reliably intervenes between the conducting wire and the magnetic sheet, so that the insulation between the conducting wire and the magnetic sheet is ensured and the thickness is reduced. Can be achieved.

  In addition, since the width of the recess is more than twice the thickness of the magnetic sheet, the insulating sheet reliably intervenes between the conductive wire and the magnetic sheet, so that the insulation between the conductive wire and the magnetic sheet is ensured and the thickness is reduced. Can be achieved.

  Moreover, since the wire diameter of the conducting wire is smaller than the thickness of the magnetic sheet and the thickness of the insulating sheet is 20 to 50 μm, the insulating sheet reliably intervenes between the conducting wire and the magnetic sheet. Insulation can be ensured and thinning can be achieved.

Further, the coil 21 is not limited to being annularly wound, and may be wound in a square shape or a polygonal shape. Furthermore, the inner side has a three-stage structure, the outer side has a two-stage structure, the inner side is wound in multiple stages, and the outer side is wound with a number of stages smaller than the number of stages wound on the inner side. An effect can be obtained.

  Next, the non-contact charging device provided with the non-contact charging module 1 of the present invention will be described. The non-contact power transmission device includes a charger including a power transmission coil and a magnetic sheet, and a main device including a power receiving coil and a magnetic sheet. The main device is an electronic device such as a mobile phone. The circuit on the charger side includes a rectifying / smoothing circuit unit, a voltage conversion circuit unit, an oscillation circuit unit, a display circuit unit, a control circuit unit, and the power transmission coil. The circuit on the main device side includes the power receiving coil, a rectifier circuit unit, a control circuit unit, and a load L mainly composed of a secondary battery.

  The power transmission from the charger to the main device is performed using an electromagnetic induction action between the power transmission coil of the charger on the primary side and the power receiving coil of the main device on the secondary side.

  Since the non-contact charging device of the present embodiment includes the non-contact charging module described above, the non-contact charging device is provided in a state in which the cross-sectional area of the planar coil portion is sufficiently secured to improve power transmission efficiency. It can be reduced in size and thickness.

  According to the non-contact charging module of the present invention, since the non-contact charging module can be thinned in a state in which the cross-sectional area of the planar coil portion is sufficiently secured, a portable terminal such as a mobile phone or a portable computer, It is useful as a non-contact charging module for various electronic devices such as portable devices such as video cameras.

DESCRIPTION OF SYMBOLS 1 Non-contact charge module 2 Planar coil part 21 Coil 22,23 Terminal 24 Foot | leg part 3 Magnetic sheet 31 Flat part 32 Center part 33 Concave part 34 Slit (1st slit)

Claims (5)

A planar coil portion wound with a conducting wire;
The Mn-Zn based ferrite sheet placed so as to face the coil surface on the side on which the planar coil part is placed with the first insulating sheet interposed therebetween,
A slit provided on the Mn-Zn ferrite sheet and extending from the winding start point of the coil surface to the end of the Mn-Zn ferrite sheet;
The Mn-Zn based ferrite from the coil surface on which the conductive wire is wound in the conductive wire of the planar coil portion and the winding start point of the coil surface so that the conductive wire of the planar coil portion does not contact the side wall of the slit The portion where the conductive wire to the end of the sheet is laminated is housed in the slit by pushing the first insulating sheet into the slit,
The conducting wire of the planar coil portion is insulated from the Mn-Zn based ferrite sheet by the first insulating sheet,
A non-contact charging module comprising a second insulating sheet covering the slit on a side of the Mn—Zn ferrite sheet facing the coil surface. The contactless charging module according to claim 1, wherein a width of the slit is three times or more a wire diameter of the conducting wire. 2. The contactless charging module according to claim 1, wherein a wire diameter of the conducting wire is smaller than 0.3 mm, and a thickness of the first insulating sheet is 5 to 20 μm. 2. The contactless charging module according to claim 1, wherein a through-hole smaller than a wire diameter of the conducting wire is formed in a portion of the first insulating sheet facing the slit. A non-contact charging device comprising the non-contact charging module according to claim 1.

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