KR102577521B1 - Magnetic shilding sheet and mathod of manufacturing magnetic shilding sheet - Google Patents

Abstract

A magnetic field shielding sheet is provided. The magnetic field shielding sheet according to an embodiment of the present invention is disposed on one side of an antenna including a hollow portion with a predetermined area in the center and a pattern portion surrounding the hollow portion, and is a sheet made of a magnetic material to shield the magnetic field. main body; And at least one eddy current reduction pattern portion formed on the sheet body to increase the resistance of the sheet body to reduce the generation of eddy currents, wherein the eddy current reduction pattern portion has a total area of the sheet body of a plurality of pieces. It is locally formed to have a linear area with a length longer than the width in some of the areas corresponding to the pattern portion of the antenna so that the sheet main body can have a permeability of 2000 or more without being separated into sections, Of the total area of the sheet body, the remaining portion excluding the eddy current reduction pattern portion may not be separated into a plurality of pieces.

Description

Magnetic field shielding sheet and manufacturing method thereof {MAGNETIC SHILDING SHEET AND MATHOD OF MANUFACTURING MAGNETIC SHILDING SHEET}

The present invention relates to a magnetic field shielding sheet and a method of manufacturing the same.

Near field communication (NFC) and wireless charging are essentially non-contact transmission methods. This non-contact transmission method is implemented through an antenna that transmits or receives a magnetic field, and a magnetic field shielding sheet placed on one side of the antenna to smoothly transmit or receive the magnetic field.

Typically, sheets made of magnetic materials such as amorphous ribbon sheets, ferrite sheets, or polymer sheets are used as magnetic field shielding sheets.

Meanwhile, magnetic field shielding sheets are used in the form of multiple pieces to significantly reduce losses due to eddy currents or improve the flexibility of the sheets themselves.

For example, the magnetic field shielding sheet may be separated into multiple pieces through a flake process. That is, in the flake process, the magnetic field shielding sheet can be separated into multiple pieces by passing the magnetic field shielding sheet multiple times between a metal roller equipped with a plurality of concavo-convex or spherical balls on the outer surface and a rubber roller disposed opposite the metal roller. .

Accordingly, in order to manufacture a magnetic field shielding sheet formed separately into multiple pieces, a separate flake process is added to separate the shielding sheet itself into a plurality of pieces, thereby increasing the production cost.

In addition, a magnetic field shielding sheet formed separately into a plurality of pieces through a conventional flake process can be implemented as a shielding sheet showing uniform characteristics only when the flake process is performed multiple times.

However, as the flake process is repeatedly performed, the size of the separated pieces decreases while the total number of separated pieces increases. Therefore, as the flake process is repeatedly performed, the resistance of the shielding sheet increases, thereby reducing the effect of eddy currents. However, there is a problem in that the permeability of the shielding sheet falls below 1500.

Because of this, in order to implement a magnetic field shielding sheet with a high magnetic permeability of 2000 or more while increasing the resistance of the shielding sheet itself, there is a problem in that the overall thickness of the magnetic field shielding sheet must be increased.

The present invention was developed in consideration of the above points, and is a magnetic field shielding sheet capable of realizing a high permeability of 2000 or more while having a very thin thickness by forming an eddy current reduction pattern portion locally in the area corresponding to the antenna out of the total area, and the same. The purpose is to provide a manufacturing method.

In addition, the present invention can selectively form an eddy current reduction pattern locally in the area corresponding to the antenna out of the total area without performing a separate flake process, and prevents the generation of burrs or particles in the process of forming the eddy current reduction pattern. Another purpose is to provide a magnetic field shielding sheet and a method of manufacturing the same.

In order to achieve the above-described object, the present invention is disposed on one side of an antenna including a hollow portion with a predetermined area in the center and a pattern portion surrounding the hollow portion, and includes a sheet body made of a magnetic material to shield a magnetic field; And at least one eddy current reduction pattern portion formed on the sheet body to increase the resistance of the sheet body to reduce the generation of eddy currents, wherein the eddy current reduction pattern portion has a total area of the sheet body of a plurality of pieces. It is locally formed to have a linear area with a length longer than the width in some of the areas corresponding to the pattern portion of the antenna so that the sheet main body can have a permeability of 2000 or more without being separated into sections, The remaining portion of the entire area of the sheet body, excluding the eddy current reduction pattern portion, provides a magnetic field shielding sheet that is not separated into a plurality of pieces.

Additionally, the eddy current reduction pattern portion may be a portion formed separately into a plurality of pieces by a plurality of cracks.

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Additionally, the sheet body may include a number of cracks extending from an edge defining the eddy current reduction pattern portion.

Additionally, the eddy current reduction pattern portion includes a plurality of regular cracks formed in a predetermined shape; and a plurality of irregular cracks derived from the plurality of regular cracks.

Additionally, the regular cracks may be formed to have any one of the cross-sectional shapes of '-', '+', 'x', '*', 'ㅗ', and '·'.

Additionally, the eddy current reduction pattern portion may be a penetrating portion formed to penetrate the sheet body.

Additionally, the eddy current reduction pattern portion may include a plurality of penetrating portions, and the plurality of penetrating portions may be arranged linearly along one direction to form a dotted line shape, and may be spaced apart from each other by a predetermined distance.

Additionally, the eddy current reduction pattern portion may include a plurality of cracks extending from the penetrating portion.

In addition, the eddy current reduction pattern portion may be formed in a plurality in an area corresponding to the pattern portion, and the plurality of eddy current reduction pattern portions may be arranged radially.

In addition, the magnetic field shielding sheet is a magnetic field shielding sheet for a combo antenna unit in which a wireless power transmission antenna and a wireless communication antenna are patterned to surround the circumference of the wireless power transmission antenna on at least one side of the circuit board, and the eddy current reduction pattern The portion may be formed to be located in an area corresponding to the antenna for wireless power transmission without being formed in an area corresponding to the antenna for wireless communication among the total area of the sheet body.

Meanwhile, the present invention is a method of manufacturing a magnetic field shielding sheet disposed on one side of an antenna including a hollow portion having a predetermined area in the center and a pattern portion surrounding the hollow portion, wherein the sheet is made of a magnetic material and has a first area. The first step of preparing a magnetic sheet; and separating the magnetic sheet into a shielding sheet having a second area that is relatively narrower than the first area, applying pressure to the local area so that the local area of the inner region of the shielding sheet can be separated into a plurality of pieces. It provides a method of manufacturing a magnetic field shielding sheet including a second step.

In addition, the second step includes a cutting blade for processing the edge of the shielding sheet, and at least one pressing member disposed inside the cutting blade and pressing the local area of the magnetic sheet. It can be performed through .

Additionally, the pressing member may be a crack blade having a shape corresponding to the regular cracks to form a plurality of regular cracks formed in a predetermined shape on the sheet body.

Meanwhile, the present invention is a method of manufacturing a magnetic field shielding sheet disposed on one side of an antenna including a hollow portion having a predetermined area in the center and a pattern portion surrounding the hollow portion, wherein the sheet is made of a magnetic material and has a first area. The first step of preparing a magnetic sheet; Forming a penetrating part having a predetermined width and length in the inner region of the sheet main body and first punching the sheet main body to form a plurality of cracks extending from the penetrating part; and secondary punching of the sheet body to form a shielding sheet including the penetrating portion and having a second area that is relatively narrower than the first area.

In addition, the first punching step includes a ring-shaped edge blade for forming an edge of the penetrating portion and an inner area of the edge blade so that the cut piece cut from the sheet body can be separated by pressing. It can be performed through a mold including a separation member formed in.

Additionally, the step of secondary punching the sheet main body may be a step of forming an outer border defining the second area on the sheet main body so that the shielding sheet can be separated from the sheet main body.

According to the present invention, the overall resistance is increased through the eddy current reduction pattern portion to reduce the occurrence of eddy currents, and a high permeability of 2000 or more can be realized while having a very thin thickness.

In addition, the present invention can selectively form an eddy current reduction pattern locally in the area corresponding to the antenna out of the total area without performing a separate flake process, and prevents the generation of burrs or particles in the process of forming the eddy current reduction pattern. By doing so, the production yield can be increased.

1 is a view showing a magnetic field shielding sheet according to an embodiment of the present invention;
Figure 2 is an enlarged view of part of the eddy current reduction pattern part of Figure 1, a diagram conceptually showing the detailed configuration of the crack part;
Figure 3 is a schematic diagram showing a case where the magnetic field shielding sheet applied to the present invention is made of a multi-layer amorphous alloy or nano-crystal grain alloy;
Figure 4 is an enlarged view showing regular cracks and irregular cracks included in the crack portion;
Figure 5 is a diagram conceptually showing the detailed configuration of the penetrating part of the eddy current reduction pattern part of Figure 1;
6 is a diagram conceptually showing a penetration portion formed in the form of a dotted line;
Figure 7 is a diagram conceptually showing the behavior of a portion of the sheet body in contact with the protrusion when forming a penetrating portion;
Figure 8 is a view showing that the eddy current reduction pattern portion is formed in the area corresponding to the pattern portion of the antenna;
Figure 9 is a diagram conceptually showing various types of eddy current reduction pattern parts that can be formed in the area corresponding to the pattern part of the antenna in Figure 8 and cracks induced therefrom;
Figure 10 is a view showing that the eddy current reduction pattern portion is formed in the area corresponding to the hollow portion of the antenna;
Figure 11 is a diagram conceptually showing various types of eddy current reduction pattern parts that can be formed in the area corresponding to the hollow part of the antenna in Figure 10 and cracks induced therefrom;
12 is a plan view of a wireless power transmission module according to an embodiment of the present invention;
13 is a flowchart showing a method of manufacturing a magnetic field shielding sheet according to an embodiment of the present invention;
14 is a diagram schematically showing a mold that can be used to manufacture a magnetic field shielding sheet according to an embodiment of the present invention;
Figure 15 is a diagram schematically showing the process using a crack blade in the method of manufacturing a magnetic field shielding sheet according to an embodiment of the present invention;
16 is a view showing various forms of crack blades applied to the present invention;
17 is a flowchart showing a method of manufacturing a magnetic field shielding sheet according to another embodiment of the present invention;
Figure 18 is a diagram conceptually showing a type of mold that can be used in the first punching step in the method of manufacturing a magnetic field shielding sheet according to another embodiment of the present invention;
Figures 19 and 20 are plan views showing a mold that can be applied to Figure 18;
Figure 21 is a plan view showing another form of the upper mold for primary punching that can be applied to Figure 20;
Figure 22 is a plan view showing a type of mold that can be used in the secondary punching step in the method of manufacturing a magnetic field shielding sheet according to another embodiment of the present invention;
Figure 23 is a plan view showing the multi-layer sheet in a state in which the first punching has been completed using the mold of Figures 19 and 20, and Figure 24 is a plan view showing the multi-layer sheet of Figure 23 after the second punching has been completed using the mold shown in Figure 22 A floor plan showing the multi-layer sheet in its current state,
Figure 25 is a cross-sectional view taken from part AA of Figure 24.

Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. The present invention may be implemented in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts not related to the description are omitted, and identical or similar components are given the same reference numerals throughout the specification.

The magnetic field shielding sheet 100 according to an embodiment of the present invention includes a sheet body 110 and an eddy current reduction pattern portion 120, as shown in FIG. 1.

The sheet body 110 may be made of a magnetic material to shield the magnetic field generated from the antenna unit 200.

Here, the antenna unit 200 may include at least one antenna 220 or 230 including a hollow portion having a predetermined area in the center and a pattern portion formed to surround the hollow portion with a predetermined number of turns. In this case, the at least one antenna (220, 230) may be a planar coil in which a conductive member having a predetermined wire diameter is wound multiple times, or an antenna patterned on one side of the circuit board 210 as shown in FIG. 12. It could be a pattern.

In addition, the at least one antenna 220, 230 may be a wireless power transmission antenna 220 for transmitting or receiving wireless power, an MST antenna for magnetic payment, or an NFC antenna 230 for short-distance communication. there is. In addition, the antenna unit 200 may be configured as a combo type including two or more of the above-described wireless power transmission antenna 220, MST antenna, and NFC antenna 230.

At this time, the sheet body 110 may be formed of a material containing a metal component.

For example, the sheet body 110 may be a ribbon sheet containing at least one type of amorphous alloy and nanocrystalline alloy. However, the material of the sheet body 110 is not limited to this, and any known material used as a magnetic field shielding sheet, such as ferrite, polymer, permalloy, etc., can be used.

In one embodiment of the present invention, the sheet body 110 may be formed of a single layer of ribbon sheet 111a, but as shown in FIG. 3, a plurality of ribbon sheets 111a are interposed through the first adhesive layer 111b. It may be a multi-layer sheet laminated in multiple layers, or it may be a hybrid sheet that combines an amorphous alloy ribbon sheet and a nano-crystal grain alloy ribbon sheet.

At this time, each ribbon sheet 111a constituting the sheet body 110 may be a heat-treated ribbon sheet, and is attached to at least one of the upper and lower surfaces of the sheet body 110 through the second adhesive layer 112. The protective film 113 may be attached.

Preferably, the protective film 113 may be attached to the upper and lower surfaces of the sheet body 110, respectively. At this time, the protective film 113 attached to the sheet body 110 may be a removable release film.

The magnetic field shielding sheet 100 according to an embodiment of the present invention may include an eddy current reduction pattern portion 120 formed on the inside of the sheet body 110.

This eddy current reduction pattern portion 120 can reduce the occurrence of eddy currents by increasing the overall resistance of the sheet body 110. Through this, the antenna unit 200 can reduce the influence of eddy currents through the eddy current reduction pattern unit 120, thereby reducing the influence of at least one antenna (220, 230) by eddy currents.

For example, the eddy current reduction pattern portion 120 is a part physically modified by forming a crack portion 130 or a penetration portion 140 in a portion of the sheet body 110 to reduce the occurrence of eddy currents. It can be implemented in various forms depending on the type and arrangement of the crack portion 130 or the penetration portion 140.

First, in one embodiment of the present invention, we will look at how the eddy current reduction pattern part 120 is formed by the crack part 130 among the various forms of the eddy current reduction pattern part 120.

As shown in FIG. 2, the eddy current reduction pattern portion 120 is a crack that is separated into a plurality of pieces by a plurality of cracks 131 over an area of the sheet body 110 having a predetermined width and length. It may be 130. In this case, the entire area of the sheet body 110, excluding the portion separated into the plurality of pieces, may not be separated into a plurality of pieces.

Here, the crack 131 included in the crack portion 130 may be a single-layer structure that physically disconnects the sheet body 110 so that the sheet body 110 is divided into a plurality of pieces, and the sheet body 110 is shown in the figure. It can be formed by receiving pressure through the pressing member 14 shown in 14 and splitting.

At this time, the plurality of pieces separated by the crack 131 may be cut off from each other but remain in contact with each other (see part (A) of FIG. 3), and a fine space may be formed between the plurality of pieces. (Refer to part (B) of Figure 3) The fine space formed in this way is similar at first glance in that it forms a space between the sheet bodies 110 compared to the through portion 140, which will be described later, but its width is very fine. It can be distinguished from the penetrating portion 140.

As a non-limiting example of the crack portion 130 including the crack 131, the area where the crack portion 130 is formed may be formed linearly with a predetermined width and length as shown in FIG. 2.

At this time, the linear crack portion 130 is formed by applying pressure to one surface of the seat body 110 through a pressing member 14, etc., whose end in contact with the seat body 110 is formed to correspond to the area of the linear shape. can be formed. Accordingly, a plurality of cracks 131 may be formed in the sheet body 110 with respect to a linear area having a predetermined width and length, and the sheet body 110 may be separated into a plurality of pieces.

In addition, cracks 131 may be formed in the sheet body 110 not only in the linear area, but additionally, a plurality of cracks 132 may be formed extending from the edge defining the crack portion 130.

That is, in the process of pressing the sheet body 110 through the pressing member 14 to form a crack 131 with respect to the linear area in the sheet body 110, from the edge defining the crack portion 130 Cracks 132 extending outward may be formed together.

Meanwhile, as another example of the crack portion 130 including the crack 131, the crack portion 130 is formed from a plurality of regular cracks 133 formed in a predetermined shape and the plurality of regular cracks 133. It may include a number of derived irregular cracks (134).

More specifically, when the sheet body 110 is pressed by the crack blade 16 formed in a predetermined shape as shown in FIG. 16, the sheet body 110 has a blade corresponding to the crack blade 16. A crack 133 with a regular shape may be formed. At this time, not only the regular cracks 133 but also the irregular cracks 134 are induced, so that a plurality of cracks 133 and 134 may be formed overall in a predetermined area adjacent to the crack blade 16.

A crack portion 130 in which a predetermined area included in the sheet body 110 is separated into a plurality of pieces can be formed by such regular cracks 133 and irregular cracks 134.

At this time, the regular crack 133 may have a cross-sectional shape such as '-', '+', 'x', '*', 'ㅗ', or '·' as an illustrative example (see Figure 16 ) Descriptions related to this will be described in more detail through descriptions related to the manufacturing method of the magnetic field shielding sheet according to an embodiment of the present invention.

In this way, the magnetic field shielding sheet 100 according to an embodiment of the present invention forms various types of cracks 131 to 134 in the local area of the sheet body 110, thereby increasing the overall resistance of the sheet body 110. By doing so, the generation of eddy currents can be reduced and the influence of eddy currents can be reduced.

Next, among the various forms of the eddy current reduction pattern portion 120, we will look at the one in which the eddy current reduction pattern portion 120 is formed by the penetration portion 140 other than the crack portion 130 described above.

The magnetic field shielding sheet 100 according to an embodiment of the present invention includes an eddy current reduction pattern portion 120, a penetrating portion 140 formed in the inner region of the sheet body 110, as shown in FIG. 5, and the It may include a plurality of cracks 141 extending from the penetrating portion 140.

For example, the penetrating portion 140 may be formed to penetrate the sheet body 110, and the plurality of cracks 141 may be formed to extend from the penetrating portion 140 to the inside of the sheet body 110. It can be. At this time, the plurality of cracks 141 are formed by being induced from the penetration part 140 through an external force applied to the sheet body 110 during the process of forming the penetration part 140 in the sheet body 110. It may be.

Here, the plurality of cracks 141 are different from the above-described cracks 131 to 134 in that they are caused during the process of forming the penetration portion 140, and the sheet body 110 It may have a similar structure in that it physically disconnects.

In this case, the plurality of cracks 141 formed from the penetrating portion 140 may or may not be connected to each other. Additionally, only some of the plurality of cracks 141 may be connected to each other.

Accordingly, the magnetic field shielding sheet 100 according to an embodiment of the present invention is resistant to eddy currents because the overall resistance can be increased through the penetration portion 140 and the plurality of cracks 141 formed in the sheet body 110. The impact may be reduced. That is, the penetration portion 140 and the plurality of cracks 141 formed in the sheet body 110 can function as an eddy current reduction means capable of reducing eddy current.

At this time, the penetrating portion 140 may be formed to have a predetermined width and length, and may be formed in one or more appropriate numbers. Additionally, the penetrating portion 140 may be formed to have a length longer than the width. In addition, the total number of the plurality of cracks 141 may be relatively greater than the total number of the penetrating portions 140.

As a non-limiting example of the penetrating part 140, the penetrating part 140 may be formed linearly with a length longer than the width, as shown in FIG. 5.

As another example, as shown in FIG. 6, the penetrating portions 140 are arranged linearly along one direction so that the plurality of penetrating portions 140 form an overall dotted line shape, but are spaced apart from each other by a predetermined distance. It could be. The purpose of forming the plurality of penetrating portions 140 to form a dotted line like this is to minimize the longitudinal length of the protruding portion 18 penetrating the sheet body 110.

In more detail, when the penetrating portion 140 is formed through the linear protrusion 18 extending in the longitudinal direction as shown in FIG. 19, the protruding portion 18 penetrates the sheet body 110 as shown in FIG. 7. During the process of returning to its original position, parts of the sheet body disposed on both sides of the protrusion 18 may move in the same direction as the protrusion 18 due to the adhesive force between the protrusion 18 and the sheet main body 110.

At this time, the behavior between the portions of the seat body disposed on both sides of the protrusion 18 may be asymmetrical. The longer the longitudinal length of the protrusion 18, the greater the movement of the portions of the seat body disposed on both sides of the protrusion 18. As the range of motion increases, the degree of asymmetry of the portions of the seat body on both sides of the protrusion 18 may also increase.

This asymmetry not only degrades the function of the eddy current reduction pattern portion 120 itself, but also causes an electrical short circuit, so a separate planarization process may be required, which may act as a disadvantage in terms of functionality and process.

As described above, the magnetic field shielding sheet 100 according to an embodiment of the present invention minimizes the longitudinal length of the protrusion 18 and forms the penetrating portion 140 in the form of a dotted line, thereby reducing the asymmetry of the sheet body 110 described above. problems can be effectively solved.

In one embodiment of the present invention, the sheet body 110 may include a protective film 113 attached to at least one surface via an adhesive layer 112, as described above.

At this time, the protective film 113 may be attached to the sheet body 110 to cover the portion 120 formed separately into a plurality of pieces. Through this, even if the sheet body 110 includes the eddy current reduction pattern portion 120, which is a portion formed separately into a plurality of pieces, it is possible to prevent the pieces constituting the eddy current reduction pattern portion 120 from being separated, The sheet body 110 can maintain its plate-shaped shape through the protective film 113.

Additionally, when forming the eddy current reduction pattern portion 120 including the penetrating portion 140, it may be formed to penetrate both the sheet body 110 and the protective film 113. This will be explained in more detail through a description of the method of manufacturing a magnetic field shielding sheet according to an embodiment of the present invention, which will be described later.

In the magnetic field shielding sheet 100 according to an embodiment of the present invention, the eddy current reduction pattern portion 120 may be formed in one or more appropriate numbers for a portion of the total area of the sheet body 110, and the sheet It may be partially formed for a portion of the total area of the main body 110.

Through this, the magnetic field shielding sheet 100 according to an embodiment of the present invention partially forms an eddy current reduction pattern portion 120 in a partial area corresponding to the area where the antennas 220 and 230 are disposed, thereby reducing the overall resistance of the sheet itself. By increasing , it is possible to have a high permeability of over 2000 at a very thin thickness while minimizing the influence of eddy currents.

For example, the magnetic field shielding sheet 100 according to an embodiment of the present invention can have a high permeability of 2000 or more even with a very thin total thickness of 55㎛ to 85㎛.

Because of this, the magnetic field shielding sheet 100 according to an embodiment of the present invention can increase the inductance of at least one antenna (220, 230) while realizing thinning through a very thin thickness.

Such eddy current reduction pattern portion 120 may be formed radially based on the center point of the internal hollow portion of the antennas 220 and 230, as shown in FIG. 1. However, the arrangement of the eddy current reduction pattern portion 120 in the magnetic field shielding sheet 100 according to an embodiment of the present invention is not limited to this, and if formed at a position corresponding to the antennas 220 and 230, the eddy current reduction pattern Part 120 may be formed in various ways as shown in FIGS. 9 and 11.

In addition, when the antenna unit 200 includes a plurality of antennas, the eddy current reduction pattern portion 120 may be formed in an area corresponding to each of the plurality of antennas, or may be formed in an area corresponding to some of the plurality of antennas. It may be formed only in an area.

As a specific example, the eddy current reduction pattern portion 120 may be partially formed in only a portion of the total area of the shielding sheet 300, which is the final product.

That is, the eddy current reduction pattern portion 120 may be formed in a portion of the total area of the final product, the shielding sheet 300, where the pattern portion P of the antenna 211 is disposed, as shown in FIG. , a partial area where the pattern portion (P) of the antenna 211 is disposed may be the above-described placement area (A1).

Through this, the eddy current reduction pattern portion 120 may be formed in the shielding sheet 300 only for a portion of the entire area of the shielding sheet 300 corresponding to the pattern portion (P) of the antenna 211. .

In this case, the eddy current reduction pattern portion 120 formed on a portion of the area corresponding to the pattern portion P of the antenna 211 may be formed in various ways as shown in FIG. 9.

As another example, the eddy current reduction pattern portion 120 may be formed only in a partial area where the magnetic flux is concentrated among the total area of the final product, the shielding sheet 300, as shown in Figure 10, and the partial area where the magnetic flux is concentrated As described above, may be a corresponding area (A2) corresponding to the hollow part (E) of the antenna 211.

Through this, the final product, the shielding sheet 300, has the eddy current reduction pattern portion 120 formed only on a portion of the total area of the shielding sheet 300 corresponding to the hollow portion (E) of the antenna 211. You can.

In this case, the eddy current reduction pattern portion 120 formed over a portion of the area corresponding to the hollow portion E of the antenna 211 may be formed in various ways as shown in FIG. 11.

The magnetic field shielding sheet 100 according to an embodiment of the present invention described above may be implemented as a wireless power transmission module 400 for wireless power transmission.

For example, the wireless power transmission module 400 includes an antenna unit 200 including a wireless power transmission antenna 220 for wireless power transmission, and one surface of the antenna unit 200, as shown in FIG. 12. It may include a magnetic field shielding sheet 100 that is arranged to shield the magnetic field and focus the magnetic field in a desired direction.

Here, the antenna unit 200 may be a combo antenna unit that includes, in addition to the antenna 220 for wireless power transmission, a wireless communication antenna 230 arranged to surround the outside of the wireless power transmission antenna 220, The antenna 220 for wireless power transmission and the antenna 230 for wireless communication may be an antenna pattern formed on one surface of the circuit board 210.

In this way, when the antenna unit 200 is formed as a combo antenna unit, the eddy current reduction pattern portion 120 corresponds to the area where the wireless power transmission antenna 220 is disposed among the total area of the sheet body 110. It can only be formed in an area. That is, the eddy current reduction pattern portion 120 may not be formed in the remaining areas of the combo antenna unit 200 except for the area corresponding to the area where the antenna 220 for wireless power transmission is disposed.

In particular, the eddy current reduction pattern portion 120 may not be formed in an area corresponding to the area where the antenna 230 for wireless communication is disposed.

Through this, the magnetic field shielding sheet 100 according to an embodiment of the present invention forms an eddy current reduction pattern portion 120 partially in a partial area corresponding to the area where the wireless power transmission antenna 220 is disposed, thereby forming the sheet. By increasing its overall resistance, it can have a high permeability of over 2000 at a very thin thickness while minimizing the effect of eddy currents.

Meanwhile, the antenna unit 200 may further include an antenna for MST.

Here, the magnetic field shielding sheet 100 constituting the wireless power transmission module 400 may be the magnetic field shielding sheet 100 described above, and since the magnetic field shielding sheet 100 is the same as described above, detailed description is provided. Decided to omit it.

The wireless power transmission module 400 may be implemented as a wireless power reception module in which the wireless power transmission antenna 220 functions as a wireless power reception antenna for receiving wireless power, and the wireless power transmission antenna 220 may be implemented as a wireless power reception module. The antenna 220 may be implemented as a wireless power transmission module that functions as a wireless power transmission antenna that transmits wireless power to the outside.

In addition, when the wireless power transmission module 400 is implemented as a wireless power reception module, the wireless power transmission module 400 can be applied to portable terminal devices such as mobile phones and tablet PCs.

Meanwhile, the above-described magnetic field shielding sheet 100 can be manufactured through the manufacturing method below.

Referring to Figure 13, when first forming the crack portion 130 to form the eddy current pattern reduction portion 120, the method of manufacturing a magnetic field shielding sheet according to an embodiment of the present invention includes the first step (S11) and the first step (S11). It may include step 2 (S12).

For example, the first step (S11) may be a step of preparing a plate-shaped sheet body made of a magnetic material and having a first area, and the second step (S12) may be a step of preparing a plate-shaped sheet body having a first area from the sheet body. This may be a step of applying pressure to the local area so that the local area of the inner area of the shielding sheet can be separated into a plurality of pieces while being separated into a shielding sheet having a relatively narrow second area.

At this time, the magnetic field shielding sheet manufactured through the manufacturing method according to an embodiment of the present invention may have the above-described crack portion 130 formed through the second step (S12).

Specifically, the first step (S11) may be a preliminary step for producing the magnetic field shielding sheet 100, which is the final product, by cutting the sheet body of the first area into a predetermined size according to the intended use and purpose. Here, the seat body may be made of the same material as the seat body 110 described above.

That is, the sheet body may be a plate-shaped sheet with a first area and may be made of a magnetic material. In addition, all of the materials mentioned as materials for the seat body 110 described above may be used for the seat body of the first area. In addition, the sheet body may be formed of a material containing a metal component and may be a heat-treated sheet.

Meanwhile, in the second step (S12), the shielding sheet 100 of the second area having a relatively smaller area than the first area can be separated from the sheet main body of the first area through the mold 10.

Accordingly, the method of manufacturing a magnetic field shielding sheet according to an embodiment of the present invention can produce a plurality of shielding sheets 100 from one magnetic sheet through the second step (S12).

At this time, as described above, the method of manufacturing a magnetic field shielding sheet according to an embodiment of the present invention is separated from the sheet body of the first area into the shielding sheet 100 of the second area through the second step, and the shielding sheet is separated into the shielding sheet 100 having the second area. A crack portion 130 may be formed at (100).

That is, in the second step (S12), the shielding sheet 100 having a second area is separated from the sheet body of the first area through a single process using one mold 10, and the shielding sheet 100 is separated into a second area. A crack portion 130 may also be formed in the sheet 100.

This second step (S12) can be performed using the mold 10 shown in FIG. 14.

That is, the mold 10 includes a cutting blade 12 for processing the edge of the shielding sheet, and a cutting blade 12 disposed inside the cutting blade 12 to press the local area without penetrating the sheet body. It may include at least one pressing member 14.

For example, the pressing member 14 may be bar-shaped with a predetermined length as shown in FIG. 14, and may be formed in one or more appropriate numbers.

As another example, the pressing member 14 may be a crack blade 16 having a shape corresponding to the shape of the regular cracks 133 described above as shown in FIG. 15, and similarly, one or more appropriate numbers. can be formed.

At this time, a plurality of press members 14 may be provided inside the cutting blade 12, and the plurality of press members 14 may be spaced apart from each other.

In addition, the end of the pressing member 14 may form a horizontal plane with the end of the cutting blade 12, but may also have a length that does not protrude beyond the end of the cutting blade 12.

At this time, the pressing member 14 may be formed so that the end in contact with the sheet body has a cross-sectional area having a predetermined width and length or a shape corresponding to the regular crack 133 described above, and the cutting blade 12 ) may be formed to have approximately the same shape as the entire border of the final product, the shielding sheet 100.

Accordingly, in the second step, when the mold 10 is pressed against the sheet body of the first area, the shielding sheet 100 having a second area is formed from the sheet body of the first area through the cutting blade 12. As the shielding sheet 100 is separated from the sheet body, the crack portion 130 may be formed at a position corresponding to the pressing member 14 in the inner region.

Here, the cutting blade 12 may press the sheet body so as to penetrate the sheet body of the first area.

In addition, the pressing member 14 may press the sheet body so as to penetrate or not penetrate the sheet body depending on the case.

Specifically, when the end of the pressing member 14 is formed to have a cross-sectional area with a predetermined width and length (see FIG. 14), the pressing member 14 can be pressed so as not to penetrate the sheet body. When formed with the above-described crack blade 16, it can be pressed to penetrate the sheet body.

In addition, in the second step, in the process of forming the crack portion 130 through the pressing member 14, cracks 132 are induced from the edge defining the crack portion 130 or from a plurality of regular cracks 133. Derived irregular cracks 134 may also be induced.

Through this, according to the manufacturing method according to an embodiment of the present invention, a pressing force is provided to the sheet body side through the pressing member 14, so that the area corresponding to the position of the pressing member 14 is separated into a plurality of pieces. It can be. Through this, the crack portion 130 can be formed in an area corresponding to the position of the pressing member 14.

That is, the method of manufacturing a magnetic field shielding sheet according to an embodiment of the present invention is to remove the crack portion 130 through a single process of separating the shielding sheet 100 having a predetermined size from the sheet body without the need to perform additional processes. By being formed together, the production process can be simplified.

Through this, the shielding sheet 100 produced through the manufacturing method of the magnetic field shielding sheet according to an embodiment of the present invention can increase the overall resistance through the crack portion 130, reduce loss due to eddy current, and The transmission efficiency of the antenna can be increased by increasing the Q value.

In addition, according to the manufacturing method according to an embodiment of the present invention, the portion where the pressing force is provided by the pressing member 14 is only formed into a plurality of pieces, so a burr is formed in the portion where the crack portion 130 is formed. It is possible to prevent particles from occurring or escaping from the crack portion 130.

For this reason, according to the manufacturing method of the present invention, short circuit defects in the antennas 220 and 230 caused by burrs or particles can be improved, thereby increasing production yield. In addition, when the antennas 220 and 230 are provided with an antenna pattern formed on the circuit board 210, short circuit of the antenna due to burrs or particles is fundamentally prevented, thereby reducing the thickness of the coverlay included in the circuit board 210. Even if it is not increased, short-circuit defects in the antenna caused by burrs or fragments can be improved.

Through this, the circuit board 210 can be used with the same thin coverlay thickness as before. For this reason, the magnetic field shielding sheet 100 manufactured by the manufacturing method according to an embodiment of the present invention can be used even if the antenna unit 200 is applied with the circuit board 210 including a coverlay having a conventional thin thickness. It has the advantage of being able to fundamentally prevent short circuits caused by burrs or particles, thereby reducing production costs and reducing overall thickness.

Next, referring to FIG. 17, when forming the eddy current pattern reduction portion 120 by forming the penetrating portion 140, the method of manufacturing a magnetic field shielding sheet according to an embodiment of the present invention includes forming a sheet body of the first area ( It may include a step of preparing M) (S1), a step of primary punching of the sheet body (M) (S2), and a step of secondary punching of the sheet body (M) (S3).

The step (S1) of preparing the sheet body (M) of the first area may be a preparation step for manufacturing the final product, the shielding sheet 300, by cutting it into a predetermined size according to the intended use and purpose.

That is, the shielding sheet 300 may include a sheet body 110 of a second area as shown in FIG. 25, and a step (S2) of first punching the sheet body M of the first area. And through the step (S3) of secondary punching of the sheet body (M) of the first area, the above-described penetration portion 140 and crack 141 can be formed on the side of the sheet body 110 of the second area. there is.

As already described above, the sheet body M having the first area may be a plate-shaped sheet having the first area, and may be made of a magnetic material.

At this time, the sheet body (M) of the first area has a plurality of cracks (141) from the penetration part (140) due to external force in the process of forming the penetration part (140) in the sheet body (M) of the first area. It may be formed of a material containing a metal component and may be a heat-treated sheet so that it can be induced.

In the step (S1) of preparing the sheet body (M) of the first area, when the sheet body (M) is formed as a multi-layer sheet, a plurality of ribbon sheets (111a) are stacked through the first adhesive layer (111b). Forming a multilayer sheet with a first area formed of multiple layers and applying a protective film 113 to at least one of the upper and lower surfaces of the multilayer sheet through a second adhesive layer 112 coated with adhesive on both sides of the substrate. It may include an attaching step.

At this time, as described above, the protective film 113 attached to the sheet body M of the first area may be a removable release film.

Through this, when an outer border (L) defining a second area is formed on the side of the sheet body (M) having the first area through the secondary punching step (S3) described later, the shielding sheet having the second area is formed. 300 may be separated from the sheet body M of the first area with the second adhesive layer 112 exposed on one surface.

Accordingly, other components can be attached to the shielding sheet 300 separated from the sheet body M of the first area using the second adhesive layer 112 formed on one surface.

As a non-limiting example, as shown in the enlarged view of FIG. 18, the sheet body M of the first area includes a pair of protective films each attached to the upper and lower surfaces via a second adhesive layer 112. It may include (113). In this case, the second adhesive layer 112 may be an adhesive applied to both sides of the substrate.

However, the present invention is not limited to this, and the protective film 113 may be attached to only one of the upper and lower surfaces of the first area of the sheet body 110 through the second adhesive layer 112. , the second adhesive layer 112 may be a liquid or gel adhesive.

The step (S2) of first punching the sheet body (M) of the first area is to form a penetrating portion (140) having a predetermined width and length in the inner area of the sheet body (M) of the first area. This may be a step of forming a plurality of cracks 141 extending from the penetrating portion 140. Here, the penetrating portion 140 may be a linear penetrating portion having a predetermined width and length or a penetrating portion in the form of a dotted line as described above.

That is, the step (S2) of first punching the sheet body (M) of the first area is the outer border (L) defined through the step (S3) of secondary punching of the sheet body (M) of the first area, which will be described later. ) may be a step of forming a penetrating portion 140 in the inner region of the penetrating portion 140, and may be a step of simultaneously forming the penetrating portion 140 and a plurality of cracks 141 caused by the penetrating portion 140.

The step (S2) of first punching the sheet body of the first area can be performed using the punching device shown in FIG. 18.

For example, the punching device includes an upper mold 10 for primary punching that is provided with a plurality of protrusions 18 protruding from one surface at a predetermined height, and is disposed at a lower part of the upper mold 10 for primary punching and includes the plurality of molds 10 for primary punching. A lower mold for primary punching (20) provided with a plurality of opening holes (22) formed at positions corresponding to the protrusions (18) and a plurality of guides for guiding the movement direction of the upper mold for primary punching (10). It may include a bar (G).

In this case, the plurality of protrusions 18 and the plurality of opening holes 22 may have a shape corresponding to the penetrating part 140 described above.

For example, the plurality of protrusions 18 and the plurality of opening holes 22 may be formed in a linear or dotted shape with a predetermined width and length, and may be formed in one or more appropriate numbers. Additionally, the plurality of protrusions 18 and the plurality of opening holes 22 may be formed to have a length longer than the width.

In addition, each of the plurality of protrusions 18 and the plurality of opening holes 22 may be spaced apart from each other as shown in FIGS. 19 and 20 and may be arranged radially with respect to the virtual center point. there is.

At this time, a first guide hole (H1) through which the guide bar (G) can pass may be formed on the side of the upper mold (10) for the first punching, and the guide may be formed on the side of the sheet body (M) of the first area. At least one second guide hole (H2) through which the bar (G) can pass may be formed.

Accordingly, the upper mold 10 for primary punching can be guided in a moving direction along the guide bar (G) when the guide bar (G) is inserted into the first guide hole (H1). The sheet body (M) can be prevented from moving when the guide bar (G) is inserted into the second guide hole (H2).

Through this, the sheet body (M) of the first area is formed by the upper mold for primary punching (10) and the lower mold for primary punching with the guide bar (G) inserted into at least one second guide hole (H2). It can be arranged to be located between (20), and one side can be pressed through movement of the upper mold 10 for the first punching.

Accordingly, when the upper mold 10 for the first punching is lowered during the first punching process, the protrusion 18 can press the sheet body M of the first area, and the sheet body of the first area ( On the M) side, a penetrating portion 140 may be formed at a position corresponding to the protrusion 18 by pressing the protrusion 18.

In addition, a number of cracks 141 induced by the pressing force transmitted from the protrusion 18 may be formed on the edge side of the penetrating portion 140 to form the penetrating portion 140.

That is, when the primary punching process is performed using the upper mold 10 for primary punching and the lower mold 20 for primary punching of the form shown in FIGS. 19 and 20, the sheet body (M) of the first area A penetrating portion 140 having a predetermined width and length may be formed in the inner region at a position corresponding to the protruding portion 18.

In this case, the inner area of the sheet body (M) of the first area has a protrusion 18 and an opening hole 22 provided in the upper mold 10 for primary punching and the lower mold 20 for primary punching, respectively. Depending on the size, a penetrating portion 140 of the type shown in FIG. 23 may be formed.

In addition, cracks 141 of the type shown in FIG. 5 may be formed around the through portion 140 of the type shown in FIG. 23 by being induced from the through portion 140.

Here, the cut piece separated from the sheet body M of the first area while forming the penetrating portion 140 may fall downward through the opening hole 22.

In this way, the method of manufacturing a magnetic field shielding sheet according to an embodiment of the present invention is to remove a plurality of cracks 141 caused from the penetrating portion 140 during the punching process of forming the penetrating portion 140 having a predetermined width and length. Because it can be formed, penetrations and cracks caused by them can be formed locally only in some areas of the total area of the final product, the shielding sheet 300.

Accordingly, by using the method for manufacturing a magnetic field shielding sheet according to an embodiment of the present invention, a shielding sheet that satisfies the design conditions and requirements can be easily manufactured.

Through this, the shielding sheet 300 produced through the method of manufacturing a magnetic field shielding sheet according to an embodiment of the present invention can realize a high permeability of 2000 or more while having a very thin thickness.

In addition, the shielding sheet 300 produced through the manufacturing method of the magnetic field shielding sheet according to an embodiment of the present invention has an overall resistance through the penetration portion 140 and the cracks 141 induced from the penetration portion 140. Because it can be increased, loss due to eddy current can be reduced and the Q value can be increased to increase the transmission efficiency of the antenna.

In this case, the protrusion 18 of the upper mold 10 for primary punching and the opening hole 22 of the lower mold 20 for primary punching are formed in the through portion 140 formed in the shielding sheet 300, which is the final product. It can be changed appropriately depending on the shape.

In addition, although not shown in the drawing, the protrusion 18 of the upper mold 10 for primary punching and the opening hole 22 of the lower mold 20 for primary punching are the through portions formed in the shielding sheet 300, which is the final product. It can be changed appropriately depending on the form. That is, the protrusion 18 of the upper mold 10 for primary punching and the opening hole 22 of the lower mold 20 for primary punching have various types of penetrating portions 140 shown in FIGS. 9 and 11. It can be configured to correspond to .

For example, each of the plurality of protrusions 18 and the plurality of opening holes 22 may be arranged radially with respect to a virtual center point, and may be arranged radially in the width or longitudinal direction of the sheet body M of the first area. They may be placed vertically or parallelly.

In addition, each of the plurality of protrusions 18 and the plurality of opening holes 22 may be arranged at an angle inclined at a certain angle with respect to the width direction or the longitudinal direction of the sheet body M of the first area, and may have a predetermined length. It may be formed in an arc-shaped shape.

In addition, each of the plurality of protrusions 18 and the plurality of opening holes 22 may be a combination of at least two of the four methods described above.

Through this, various penetrating portions 140 and cracks 141 of the form shown in FIGS. 9 and 11 will be formed in the shielding sheet 300 punched out through the punching process from the sheet body (M) of the first area. You can.

On the other hand, the upper mold 10 for primary punching used in the step (S2) of primary punching the sheet body of the first area forms the penetrating portion 140 in the sheet body M of the first area. In the process, the cut piece separated from the sheet body (M) of the first area may be configured to be removed from the sheet body (M) of the first area.

That is, the protrusion 18 in the upper mold 10 for the first punch described above can be changed to the form shown in FIG. 21.

Specifically, as shown in FIG. 21, the upper mold 10 for primary punching includes a ring-shaped edge blade 18' protruding from one surface and a separation member protruding inside the edge blade 18' ( 19) may be included.

Here, the separation member 19 may be formed in a planar shape with a predetermined width and length, and the width and length of the separation member 19 are relatively smaller than the width and length of the edge blade 18'. It can be. In addition, the separation member 19 may be formed to protrude at a certain height from the inner bottom surface of the border blade 18', and the protruding height of the separation member 19 is the same as the height of the border blade 18'. Alternatively, it may be of a relatively lower height than the border blade 18'.

In addition, the edge blade 18' may have a size corresponding to the penetration portion 140.

Accordingly, when the upper mold 10 for primary punching described above is pressed to the sheet body M of the first area during the primary punching process, the border blade 18' forms a penetrating portion ( 140), and the separation member 19 is a cut piece cut from the sheet body M of the first area through the edge blade 18' to form the penetrating portion 140. It can be pressurized downward.

Through this, the cut piece cut from the sheet body (M) of the first area through the border blade (18') can be separated from the sheet body (M) of the first area through the separation member (19). In addition, the cut piece separated from the sheet body (M) of the first area may fall downward through the opening hole (22) of the lower mold (20) for the first punching.

For this reason, when the above-described upper mold 10 for primary punching is used, a section cut from the sheet body M of the first area through the edge blade 18' is formed in the process of forming the penetration portion 140. The cut pieces can be easily removed during the first punching process without the need to separate the pieces.

Accordingly, when using the upper mold 18' for primary punching described above, the process of forming the penetration part 140 and the crack 141 on the inside of the sheet body M and the process of forming the penetration part 140 Removal of unnecessary incisions created in the process can be performed together.

Through this, if the upper mold 10 for primary punching described above is used, the entire process can be simplified even if the shielding sheet 300 including the penetration portion 140 and the crack 141 is manufactured, thereby reducing the production cost. There are advantages to this.

The step (S3) of secondary punching the sheet body of the first area is to form a shielding sheet 300 having a second area that is relatively narrower than the first area of the sheet body (M) to the sheet body of the first area ( It may be a step of forming from M).

That is, the step (S3) of secondary punching the sheet body of the first area may be a step of processing the sheet body (M) of the first area to the size of the final product, the shielding sheet 300, and the first This may be a step of forming an outer border (L) of the shielding sheet 300 having a second area from the sheet body (M) of the area, and the shielding sheet 300, which is a final product, is formed along the outer border (L). This may be a processing step so that it can be separated from the sheet body (M) of the first area.

In this case, the outer border (L) may be formed from the sheet body (M) of the first area to include a penetrating portion (140) formed through the upper mold (10) for primary punching.

Specifically, the step (S3) of secondary punching the sheet body of the first area may be performed using the secondary punching mold 30 shown in FIG. 22.

That is, the secondary punching mold 30 may include at least one outer edge blade 32 protruding from one surface at a predetermined height, and the outer edge blade 32 has a ring shape with an empty interior. can be formed.

In addition, the secondary punching mold 30, like the above-described upper mold 10 for primary punching, has a first guide hole through which the guide bar (G) passes so that movement can be guided through the guide bar (G). H1) may be included.

Accordingly, the secondary punching mold 30 is placed on the sheet main body (M) side of the first area where the penetrating portion 140 and the cracks 141 caused therefrom are formed through the primary punching upper mold 10. When pressed, an outer border defining a second area surrounds the plurality of penetrating portions 140 through the outer edge blade 32, as shown in FIG. 24, on the sheet body M side of the first area. (L) can be formed.

Through this, when the part having the second area defined through the outer border (L) is separated from the sheet body (M) of the first area, the final product, the shielding sheet 300, is formed into the sheet body (M) of the first area. ) can be manufactured from.

At this time, in the second punching step (S3) of the sheet body of the first area, the sheet body (M) of the first area has a second adhesive layer ( It may include a pair of protective films (113a, 113b) respectively attached via (112a, 112b), and the outer border (L) formed through the secondary punching mold (30) is formed on the sheet body of the first area. (M) and the second adhesive layer (112a, 112b) may be formed to penetrate both, and the outer border (L) is on the side of the protective film (113b) attached to the lower surface of the sheet body (M) of the first area. may not be formed.

That is, as shown in Figure 25, the outer border (L) includes the sheet body (M) of the first area, the second adhesive layers (112a, 112b), and the protective film (113a) attached to the upper surface of the sheet body (M). ) may be formed so as to not penetrate the protective film 113b attached to the lower surface of the sheet body (M).

Accordingly, when a plurality of shielding sheets 300 having a second area are formed on one sheet body (M) having a first area through the method of manufacturing a magnetic field shielding sheet according to an embodiment of the present invention, The protective film 113b attached to the lower surface of the sheet body M of the first area can serve as a tray to maintain the plurality of shielding sheets 300 having a second area attached to one surface. there is.

In addition, when the shielding sheet 300 having a second area is individually separated from the sheet body (M) of the first area, the shielding sheet 300 of the second area is separated from the sheet body (M) of the first area. A second adhesive layer 112b may be exposed to the outside on one side.

For this reason, the user individually separates the shielding sheet 300 of the second area from the sheet body (M) of the first area and then uses the second adhesive layer 112b exposed to the outside to secure the shielding to other parts. The sheet 300 can be attached or other parts can be attached to the shielding sheet 300.

However, the method of forming the outer border (L) described above is not limited to this, and the outer border (L) formed in the second punching step (S3) of the sheet body of the first area is formed by forming the outer border (L) of the sheet body of the first area. The shielding sheet 300 may be formed to be completely separated from (M).

That is, the outer border (L) formed through the secondary punching mold (30) is formed by the sheet body (M) of the first area, the second adhesive layers (112a, 112b), and the sheet body (M) of the first area. It may be formed to penetrate both the pair of protective films 113a and 113b attached to the upper and lower surfaces.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiment presented in the present specification, and those skilled in the art who understand the spirit of the present invention can add components within the scope of the same spirit. , other embodiments can be easily proposed by change, deletion, addition, etc., but this will also be said to be within the scope of the present invention.

100, 300: Magnetic field shielding sheet
110: Sheet body 120: Eddy current reduction pattern part
130: crack part 140: penetration part
200: Combo antenna unit 210: Circuit board
220: Antenna for wireless power transmission 230: Antenna for wireless communication
400: wireless power transmission module

Claims (19)

A magnetic field shielding sheet disposed on one side of an antenna including a hollow portion having a predetermined area in the center and a pattern portion surrounding the hollow portion,
Sheet body made of magnetic material to shield magnetic fields; and
At least one eddy current reduction pattern portion formed on the sheet body to increase the resistance of the sheet body to reduce the generation of eddy currents,
The eddy current reduction pattern portion has a length greater than the width in some regions corresponding to the pattern portion of the antenna so that the entire area of the sheet body is not separated into a plurality of pieces and the sheet body has a permeability of 2000 or more. It is formed locally to have a linear area with a long length,
A magnetic field shielding sheet in which the remaining portion of the total area of the sheet body, excluding the eddy current reduction pattern portion, is not separated into a plurality of pieces. According to clause 1,
The eddy current reduction pattern portion is a magnetic field shielding sheet that is separated into a plurality of pieces by a plurality of cracks. delete delete According to clause 2,
The sheet body is a magnetic field shielding sheet including a plurality of cracks extending from an edge defining the eddy current reduction pattern portion. According to clause 2,
The eddy current reduction pattern section is
A plurality of regular cracks formed in a predetermined shape; and
A magnetic field shielding sheet comprising a plurality of irregular cracks derived from the plurality of regular cracks. According to clause 6,
The regular crack is a magnetic field shielding sheet formed to have any one of the cross-sectional shapes of '-', '+', 'x', '*', 'ㅗ', and '·'. According to clause 1,
The eddy current reduction pattern portion is a magnetic field shielding sheet that is a penetrating portion formed to penetrate the sheet body. According to clause 8,
The eddy current reduction pattern portion includes a plurality of the through portions,
A magnetic field shielding sheet in which the plurality of penetrating portions are arranged linearly along one direction to form a dotted line shape, and are spaced apart from each other by a predetermined distance. According to clause 8,
The eddy current reduction pattern portion is a magnetic field shielding sheet including a plurality of cracks extending from the penetration portion. According to clause 1,
A magnetic field shielding sheet wherein the eddy current reduction pattern portion is formed in a plurality in an area corresponding to the pattern portion, and the plurality of eddy current reduction pattern portions are arranged radially. delete delete delete delete delete delete delete delete

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