WO2014126394A1

WO2014126394A1 - Electromagnetic wave absorbing sheet and antenna module having same

Info

Publication number: WO2014126394A1
Application number: PCT/KR2014/001178
Authority: WO
Inventors: 박종호; 임기상; 정을영; 백형일; 김범진
Original assignee: 주식회사 아모텍
Priority date: 2013-02-15
Filing date: 2014-02-13
Publication date: 2014-08-21

Abstract

The present invention relates to an electromagnetic wave absorbing sheet and an antenna module having the same, in which a first electromagnetic wave absorbing sheet and a second electromagnetic wave absorbing sheet are laminated on one surface of an antenna unit in a manner that they overlap each other, and the first electromagnetic wave absorbing sheet and the second electromagnetic wave absorbing sheet have different magnetic permeabilities. Therefore, the present invention can simplify the assembly process, remarkably degrade the external appearance defect rate, improve productivity, and improve both the short-range wireless communication function and the wireless charging function.

Description

Electromagnetic wave absorption sheet and antenna module having same

The present invention relates to an electromagnetic wave absorbing sheet and an antenna module having the same, and more particularly, to an electromagnetic wave absorbing sheet and an antenna module having the same to improve the performance of near field communication and wireless charging at the same time.

The present invention claims the benefits of Korean Patent Application No. 10-2013-0016265 filed February 15, 2013 and Korean Patent No. 10-2014-0016056 filed February 12, 2014, the entire contents of which are set forth herein. Included in

Near Field Communication (NFC) refers to a technology for transmitting data between terminals at a close distance in a non-contact manner using a band of about 13.56 MHz as an electronic tag. NFC is widely used not only for payment, but also for transmitting goods information, travel information for visitors, and traffic control locks in supermarkets and general stores.

In recent years, the market for portable terminals such as tablets and smart phones is expanding rapidly. Portable terminals have tended to include functions such as information exchange, payment, ticket reservation, and search between terminals using short-range communication (ie, NFC). Accordingly, the demand for the antenna module used in the short-range communication method is increasing.

Wireless charging technology is a technology for charging by using radio waves, mainly magnetic induction (WPC) is applied, the magnetic induction wireless charging technology refers to a technology for wireless charging using magnetic induction. Smartphones are gradually longer in use time by the user, and thus there is an inconvenience in that the battery pack needs to be charged at any time. Accordingly, there is a trend to add a wireless charging function to the antenna module for the convenience of smartphone users.

The antenna module including the NFC and the wireless charging function uses an electromagnetic wave absorbing sheet to prevent antenna performance from being degraded by electromagnetic waves and external electromagnetic waves generated from the battery pack and to block electromagnetic waves generated from the terminal.

In order to improve the electromagnetic wave absorption characteristics of the electromagnetic wave absorption sheet, it is necessary to use a high dielectric material or increase its thickness. Recently, the electromagnetic wave absorption sheet is formed in a single layer, and its thickness is limited in accordance with the trend of miniaturization and slimming electronic products.

Referring to FIG. 1, the electromagnetic wave absorption sheet 150 is disposed between the battery pack 120 and the antenna unit 140 of the portable terminal 110 and attached to the antenna unit 140. One including a first electromagnetic wave absorbing sheet 160 having a shape in which a hole exposing a wireless charging antenna pattern and a second electromagnetic wave absorbing sheet 170 disposed in a hole of the first electromagnetic wave absorbing sheet 160. Form into layers.

1, the perforated portion is discarded and wasted because the perforated portion of the first microwave absorption sheet 160 is formed in the first electromagnetic wave absorption sheet 160 in order to form the electromagnetic wave absorption sheet 150 as one layer. There was a problem, and a punching process for attaching the second electromagnetic wave absorbing sheet 170 to the antenna unit 140 by forming the second electromagnetic wave absorbing sheet 170 to be exactly matched with the perforated hole of the first electromagnetic wave absorbing sheet 160 is required. In addition, in the assembling process, the second electromagnetic wave absorbing sheet 170 and the first electromagnetic wave absorbing sheet 160 may be displaced from the attachment position of the antenna unit 140, thereby causing a poor appearance.

As another example of FIG. 1, referring to FIG. 2, the first electromagnetic wave absorption sheet 160 is divided and attached to the antenna unit 240 to minimize the discarded portion of the first electromagnetic wave absorption sheet 160. can do.

That is, the electromagnetic wave absorbing sheet 250 includes a first electromagnetic wave absorbing sheet 260 divided into quarters and a second electromagnetic wave absorbing sheet 270 that surrounds the outer portion of the divided first electromagnetic wave absorbing sheet 260. The first electromagnetic wave absorbing sheet 260, which is divided into the second electromagnetic wave absorbing sheet 270 and the quadrant, surrounds the outside of the second electromagnetic wave absorbing sheet 270, is attached to the antenna unit 240.

The electromagnetic wave absorbing sheet 250 of FIG. 2 has an advantage of minimizing waste of raw materials due to fewer discarded portions of the first electromagnetic wave absorbing sheet 260 than the electromagnetic wave absorbing sheet 150 of FIG. 1, but an assembly process There are a lot of attaching stages at the time, there is a high possibility of defects caused by workers.

The present invention has been made in view of the above, and an object of the present invention is to provide an electromagnetic wave absorption sheet and an antenna module having the same, which simultaneously improves short-range communication and wireless charging performance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and an object of the present invention is to provide an electromagnetic wave absorbing sheet having a high productivity, low cost, and excellent reliability of product operation due to a simple assembly process, and an antenna module having the same. .

Antenna module according to an embodiment of the present invention for achieving the above object,

An antenna unit;

A first electromagnetic wave absorption sheet disposed on one surface of the antenna unit;

And a second electromagnetic wave absorbing sheet disposed to overlap at least a portion of one surface of the first electromagnetic wave absorbing sheet.

In the present invention, the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet may be disposed between the antenna unit and the battery pack provided in the portable terminal.

In the present invention, the antenna unit, a wireless communication antenna pattern for short-range wireless communication; Wireless charging antenna pattern for wireless charging; And a base on which the antenna pattern for wireless communication and the antenna pattern for wireless charging are formed.

In the present invention, any one of the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet may improve the wireless recognition performance, the other may improve the performance of the wireless charging.

The electromagnetic wave absorption sheet according to an embodiment of the present invention for achieving the above object, the first electromagnetic wave absorption sheet; And a second electromagnetic wave absorbing sheet disposed at least partially overlapping one surface of the first electromagnetic wave absorbing sheet.

In the present invention, the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet may have a different permeability.

In the present invention, the first electromagnetic wave absorbing sheet and the second electromagnetic wave absorbing sheet may be overlapped so that the entire surface of one side may be covered by the entire surface of the other side.

In the present invention, the first electromagnetic wave absorbing sheet and the second electromagnetic wave absorbing sheet may have the same size and may be overlapped with each other.

In the present invention, the first electromagnetic wave absorption sheet or the second electromagnetic wave absorption sheet is a carbon nanosheet containing carbon nanotubes or carbon nanoparticles, an amorphous sheet including an amorphous alloy, a polymer sheet containing magnetic powder, ferrite sheet of It may be one selected.

In the present invention, the first electromagnetic wave absorption sheet is any one of carbon nanotubes including carbon nanotubes or carbon nanoparticles, amorphous sheets including amorphous alloys, polymer sheets containing magnetic powder, and ferrite sheets. The electromagnetic wave absorbing sheet may be any one of carbon nanotubes or carbon nanosheets containing carbon nanoparticles, amorphous sheets including amorphous alloys, polymer sheets containing magnetic powder, and ferrite sheets, which are different from the first electromagnetic wave absorbing sheet. .

In the present invention, any one of the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet is a polymer sheet containing magnetic powder, and the other of the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet is carbon nanotubes. Or carbon nanosheets including carbon nanoparticles, amorphous sheets including amorphous alloys, polymer sheets containing magnetic powder, and ferrite sheets.

Since the present invention forms an antenna pattern for wireless communication and an antenna pattern for wireless charging, the antenna unit can implement both a short range wireless communication function and a wireless charging function, and overlaps the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet as an electromagnetic wave absorption sheet. As a result, the assembly process is simplified, the appearance defect rate is greatly reduced, and the productivity is improved.

In addition, the present invention is excellent in the electromagnetic wave absorption rate without increasing the thickness of the electromagnetic wave absorption sheet, it is possible to reduce the size, slim and reduce the manufacturing cost of the product.

In addition, the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet has a different permeability and absorbs electromagnetic waves according to characteristics of each frequency band of the pattern, thereby improving the operational reliability of the antenna module.

1 and 2 is a view showing a state where a conventional antenna module is installed in a portable terminal.

3 is a view showing a state in which the wireless recognition and wireless charging combined antenna module according to the present invention is installed in a portable terminal.

4 is a view showing the antenna unit of FIG.

5 is a graph showing the wireless charging efficiency of Comparative Example 1, Comparative Example 2, Comparative Example 3 shown in Table 1.

* Description of the major symbols in the drawings *

10: portable terminal 20: battery pack

30: antenna module 40: antenna part

41: Pattern for wireless communication 43: Pattern for wireless charging

45:

substrate

46, 47, 48, 49: the first to fourth terminals

50: electromagnetic wave absorption sheet 60: first electromagnetic wave absorption sheet

70: second electromagnetic wave absorption sheet 80: battery cover

90: charging pad

When described in detail with reference to the accompanying drawings a preferred embodiment of the present invention.

3 shows a state in which the antenna module according to the present invention is mounted on a portable terminal, and referring to FIG. 3, the antenna module according to the present invention describes a state in which the antenna module combined with the wireless recognition and the wireless charging is disposed in the portable terminal. It is a figure for following.

The antenna module of the present invention includes an antenna unit mounted on a portable terminal, and the antenna unit includes a near field wireless communication antenna and a wireless charging antenna and has a near field wireless communication and a wireless charging function.

In addition, a first electromagnetic wave absorption sheet 60 is disposed on one surface of the antenna unit 40, and a second electromagnetic wave absorption sheet 70 is disposed on one surface of the first electromagnetic wave absorption sheet 60.

The second electromagnetic wave absorption sheet 70 is disposed to overlap at least partially on one surface of the first electromagnetic wave absorption sheet 60. It is preferable that the first electromagnetic wave absorbing sheet 60 and the second electromagnetic wave absorbing sheet 70 overlap each other so that the entire surface of one side is overlapped by the entire surface of the other side. In addition, the first electromagnetic wave absorbing sheet 60 and the second electromagnetic wave absorbing sheet 70 have the same size and overlap each other to be disposed so as to eliminate the step difference caused by the difference in size to prevent appearance defects due to the step when attached , Simplify the assembly process, and improve the convenience of the assembly process.

That is, it is preferable that the first electromagnetic wave absorption sheet 60 uses the same size as the second electromagnetic wave absorption sheet 70. When the first electromagnetic wave absorbing sheet 60 and the second electromagnetic wave absorbing sheet 70 use the same size, an antenna module having an overall uniform thickness may be manufactured.

In addition, the first electromagnetic wave absorption sheet 60 may be used relatively smaller than the second electromagnetic wave absorption sheet 70, or the second electromagnetic wave absorption sheet 70 may be formed on the first electromagnetic wave absorption sheet 60. You can use a relatively small one.

The antenna unit 40 is mounted to the portable terminal, for example, to be mounted on the inner surface of the battery cover 80 of the portable terminal.

The first electromagnetic wave absorption sheet 60 is attached to one surface of the antenna unit 40 by a bonding sheet, a double-sided tape, an adhesive, and the like, and the second electromagnetic wave absorption sheet 70 is the first electromagnetic wave absorption sheet 60. It is attached to one side of the bonding sheet, double-sided tape, adhesive or the like.

One surface of the antenna unit 40 is a surface opposite to the mounting surface on which the antenna unit 40 is mounted on the portable terminal.

One surface of the first electromagnetic wave absorption sheet 60 is a surface opposite to the attachment surface to which the first electromagnetic wave absorption sheet 60 is attached to the antenna unit 60.

That is, the antenna unit 40, the first electromagnetic wave absorption sheet 60, and the second electromagnetic wave absorption sheet 70 have a stacked structure.

On the other hand, the first electromagnetic wave absorption sheet 60 and the second electromagnetic wave absorption sheet 70 is characterized by different permeability.

That is, the antenna module according to the present invention is formed by attaching the electromagnetic wave absorbing sheet 50 having two layers having different permeability to the antenna unit 40. The electromagnetic wave absorbing sheet 50 has one sheet layer for improving wireless recognition performance, and one sheet layer for improving wireless charging performance.

The electromagnetic wave absorption sheet 50 according to the present invention covers the battery pack 20 or the battery pack 20 to be disposed between the battery pack 20 and the antenna unit 40 of the portable terminal 10. It is attached to the battery cover 80. The battery cover 80 is an example of opening and closing the battery pack 20 is detached to the back of the casing of the portable terminal 10.

The antenna module 30 has a near field communication function and a wireless charging function. The portable terminal 10 to which the antenna module 30 is attached may be charged on the charging pad 90. The charging pad 90 may have a shape in which an electric coil for generating an electromagnetic field is wound in the plastic cover.

As shown in FIG. 4, the antenna unit 40 includes a wireless communication antenna pattern 41 for short range wireless communication, a wireless charging antenna pattern 43 for wireless charging, and an antenna pattern 41 for wireless communication. It includes a substrate 45 on which the antenna pattern 43 for wireless charging is formed.

The antenna pattern for wireless communication serves as an antenna that resonates in the NFC frequency band.

For example, the antenna pattern 41 for wireless communication has one or more rows formed in a substantially rectangular loop shape, and more specifically, has a shape wound several times from the inside to the outside in a plane or a shape wound several times from the outside to the inside. The antenna pattern is formed in a loop shape at the edge of 45), and copper or nickel is plated on the surface of the antenna pattern to realize electrical characteristics.

The wireless charging antenna pattern 43 operates as a wireless charging antenna of the portable terminal.

The wireless charging antenna pattern 43 is disposed in the center of the base 45 to be spaced apart from the wireless communication antenna pattern 41 in the form of a coil wound around a circular or elliptical model, or in the center of the base 45 It is a pattern coil of circular or elliptical shape. For example, the wireless charging antenna pattern 43 is formed on the base 45 inside the antenna pattern 41 for wireless communication formed at the edge of the base 45. The wireless charging antenna pattern 43 receives the induced current generated from the charging pad 90.

In the antenna unit 40, the wireless communication antenna pattern 41 and the wireless charging antenna pattern 43 may be formed on one substrate 45. In addition, the antenna unit 40 may be formed by separately stacking two substrates after forming a wireless communication antenna pattern 41 and a wireless charging antenna pattern 43 on each substrate 45.

In the latter case, the wireless charging antenna pattern 43 and the wireless communication antenna pattern 41 are formed on the substrate while the base material on which the wireless charging antenna pattern 43 is formed and the base material on which the wireless communication antenna pattern 41 is laminated. A via hole can be connected to each other.

On the other hand, the antenna unit 40 further includes a terminal unit for electrical connection. The terminal unit includes a first terminal 46 connected to one end of the wireless charging antenna pattern 43, a second terminal 47 connected to the other end of the wireless charging antenna pattern 43, and the antenna pattern 41 for wireless communication. And a third terminal 48 connected to one end of the c) and a fourth terminal 49 connected to the other end of the antenna pattern 41 for wireless communication.

The antenna pattern 41 for wireless communication and the antenna pattern 43 for wireless charging are connected to the

terminal parts

46, 47, 48, and 49 by a connection pattern (not shown).

The substrate 45 may be a flexible substrate or an insulating film. The insulating film is an example of using a polyimide film, and in addition, any one of a polyimide (PI) film, polyethylene naphthalate (PEN) film, polyethylene terephthalate (PET) film, polycarbonate (PC) film, and polystyrene sulfonate (PSS) film It may be one.

Referring to FIG. 3, the electromagnetic wave absorption sheet 50 may include the first electromagnetic wave absorption sheet 60 attached to the antenna unit 40 and the second electromagnetic wave attached to the first electromagnetic wave absorption sheet 60. It consists of an absorbent sheet (70). That is, the first electromagnetic wave absorption sheet 60 and the second electromagnetic wave absorption sheet 70 are stacked and attached to the antenna unit 40.

The first electromagnetic wave absorbing sheet 60 and the second electromagnetic wave absorbing sheet 70 prevent electrical and magnetic influences generated from the battery pack 20 to prevent a decrease in communication performance of the antenna for wireless communication, and wireless charging It is used to improve the wireless charging performance of the antenna. For example, the antenna for wireless communication is an NFC antenna.

Using a two-layer structure in which the first electromagnetic wave absorbing sheet 60 and the second electromagnetic wave absorbing sheet 70 is laminated as an electromagnetic wave absorbing sheet simplifies the production process of the antenna module 30 according to the present invention and produces it. This is to reduce the thickness of the antenna module 30 of the present invention while lowering the unit cost.

Only a ferrite sheet having one layer may be used as the electromagnetic wave absorbing sheet. However, in this case, the thickness of the ferrite sheet should be greater than or equal to a predetermined thickness to increase the recognition distance of the wireless charging antenna during wireless charging, and to ensure sufficient wireless charging performance. It is preferable to thick.

If the thickness of the electromagnetic wave absorption sheet is thick, the thickness of the overall antenna module becomes thick, which causes the increase of the product thickness of the mobile terminal, and further increases the cost to increase the thickness of the electromagnetic wave absorption sheet.

In particular, when the ferrite sheet is used as the electromagnetic wave absorption sheet, the manufacturing cost is greatly increased as the thickness is formed thick.

The electromagnetic wave absorbing sheet 50 is disposed between the battery pack 20 and the antenna unit 40 to absorb the reaction magnetic flux from the metal surface of the battery pack 20, so that the antenna unit 40 receives radio waves. Allows you to send and receive smoothly.

One of the first electromagnetic wave absorbing sheet 60 and the second electromagnetic wave absorbing sheet 70 is for preventing the performance degradation of the wireless charging antenna.

The other of the first electromagnetic wave absorption sheet 60 and the second electromagnetic wave absorption sheet 70 is for preventing the performance degradation of the wireless communication antenna.

The first electromagnetic wave absorption sheet 60 and the second electromagnetic wave absorption sheet 70 is a permeability is applied differently according to the use and application, the permeability range corresponds to a range of permeability that can shield the electromagnetic waves.

The first electromagnetic wave absorbing sheet 60 and the second electromagnetic wave absorbing sheet 70 are different kinds of electromagnetic wave absorbing sheets.

One of the first electromagnetic wave absorption sheet 60 and the second electromagnetic wave absorption sheet 70 has a higher permeability than the other.

High permeability among the first electromagnetic wave absorption sheet 60 and the second electromagnetic wave absorption sheet 70 prevents performance degradation of the antenna unit for wireless charging, and the first electromagnetic wave absorption sheet 60 and the second electromagnetic wave The relatively low permeability of the absorbent sheet 70 prevents the performance degradation of the antenna unit for short range wireless communication.

The first electromagnetic wave absorption sheet 60 or the second electromagnetic wave absorption sheet 70 is a carbon nanosheet including carbon nanotubes or carbon nanoparticles, an amorphous sheet including an amorphous alloy, a polymer sheet containing magnetic powder, and ferrite It may be one selected from the sheet.

The first electromagnetic wave absorption sheet 60 is any one of carbon nanotubes including carbon nanotubes or carbon nanoparticles, amorphous sheets including amorphous alloys, polymer sheets containing magnetic powder, and ferrite sheets. The absorption sheet 70 is different from the first electromagnetic wave absorption sheet 60 among carbon nanotubes including carbon nanotubes or carbon nanoparticles, amorphous sheets including amorphous alloys, polymer sheets containing magnetic powder, and ferrite sheets. It is preferable to be one.

In addition, any one of the first electromagnetic wave absorption sheet 60 and the second electromagnetic wave absorption sheet 70 is a polymer sheet containing magnetic powder, the first electromagnetic wave absorption sheet 60 and the second electromagnetic wave absorption sheet. The other one of 70 is preferably a carbon nanotube or a carbon nanosheet including carbon nanoparticles, an amorphous sheet including an amorphous alloy, a polymer sheet containing magnetic powder, or a ferrite sheet.

This polymer sheet is cheaper in manufacturing cost than the carbon nanosheet, the amorphous sheet, and the ferrite sheet, and has a relatively low permeability, so that the polymer sheet can be used as a shielding sheet for an antenna for wireless communication, thereby reducing manufacturing cost and reducing thickness. .

On the other hand, the carbon nanosheets can be produced by mixing the carbon nanotubes or carbon nanoparticles and the resin, followed by heat treatment, molding by a tape casting process, drying and then rolling to improve the density.

The carbon nanotubes have a high thermal conductivity and excellent electrical conductivity to perform heat radiation in addition to the electromagnetic wave absorption function. If the grains contained in the electromagnetic wave absorption sheet are controlled to a nano size, the magnetic permeability of the electromagnetic wave absorption sheet is improved, and the electromagnetic wave absorption rate is also increased.

The amorphous alloy may be an alloy including soft magnetic powder of amorphous structure.

The soft magnetic powder of any one of Fe-Si-B, Fe-Si-B-Cu-Nb, Fe-Zr-B, and Co-Fe-Si-B compositions may be prepared into an amorphous alloy by rapid cooling.

The magnetic powder of the polymer sheet may be a Fe-based magnetic powder.

The first electromagnetic wave absorbing sheet 60 or the second electromagnetic wave absorbing sheet 70 may be provided only in a size corresponding to the antenna pattern 43 for wireless charging disposed in the center of the substrate 45. In this case, there is a disadvantage that the overall thickness of the antenna module 30 is not uniform, but the cost reduction effect is large.

The electromagnetic wave absorbing sheet according to the present invention having the multilayer structure of the first electromagnetic wave absorbing sheet 60 and the second electromagnetic wave absorbing sheet 70 has a lower manufacturing cost compared to the electromagnetic shielding sheet having the same thickness as a single layer. The effect is great and its characteristics are also excellent. In addition, the electromagnetic wave absorbing sheet according to the present invention has a larger electromagnetic wave absorbing performance with a smaller thickness than the electromagnetic wave absorbing sheet of a single layer.

This is confirmed in Tables 1 to 3 below.

Hereinafter, the characteristics of the antenna module according to an embodiment of the present invention will be described through experiments.

Table 1 shows the structure and specifications of the antenna module according to the present invention, the structure and specifications of the antenna module which is a comparative example of the present invention.

As shown in Table 1 below, the embodiment of the present invention, Comparative Example 1 and Comparative Example 2 include the same antenna unit, and the configuration of the electromagnetic wave absorption sheet is different.

Table 1

division	Antenna part				Electromagnetic wave absorption sheet		Total Thickness (mm)
	FPCB type	WPC	NFC	Thickness of adhesive	Sheet A	Sheet B
Comparative Example 1	55 × 45.5 × 0.13T (mm)	Φ39mm	55 × 45.5 mm ²	50 μm	ARS2 4N_0.15t	PC Sheet_0.2t	0.53 t
Comparative Example 2					ARS2 4N_0.15t	PC Sheet_0.2t	0.53 t
Example					ARS2 2N_0.09t	Polymer_0.2t	0.47 t

In the antenna unit of Table 1, the FPCB type is the size of the substrate, the WPC is the antenna pattern for wireless charging, the NFC is the antenna pattern for short-range communication, and the thickness of the adhesive is the thickness of the adhesive layer attaching the electromagnetic wave absorption sheet.

In addition, ARS2 of sheet A in Comparative Example 1, Comparative Example 2 and Example 2 of Table 1 is one of the electromagnetic shielding sheet according to the present invention as a kind of the amorphous sheet, in the embodiment of Table 1 Polymer is one of the electromagnetic wave shielding sheets according to the present invention, which is a kind of the polymer sheet, and the PC sheet of sheet B of Table 1 is a polycarbonate sheet, which is a general sheet rather than an electromagnetic wave shielding sheet, and the thickness is compared with Comparative Example 1 and Comparative Example. In the embodiment of the present invention 2 and confirm that it is a normal sheet inserted to match the thickness.

That is, Comparative Example 1 is an antenna module including an electromagnetic shielding sheet formed of the amorphous sheet of a single layer having a thickness of 0.15 mm, and Comparative Example 2 is an antenna module including an electromagnetic shielding sheet formed of the polymer sheet of a single layer having a thickness of 0.15 mm. On the contrary, an embodiment of the present invention is an example in which the amorphous sheet is used as the first electromagnetic wave absorption sheet 60 and the polymer sheet is used as the second electromagnetic wave absorption sheet 70. It is 0.11 mm thick and thinner than the thickness of Comparative Example 1 and Comparative Example 2.

Table 2 shows the wireless charging efficiency of the antenna module of Table 1. 4 is a graph showing the wireless charging efficiency of Table 2.

TABLE 2

division	Efficiency Test (A1 Type, with Tx Magnet)
division	Tx (mA)	Tx (V)	Rx (mA)	Rx (V)	Efficiency (%)
Comparative Example 1	260	19	650	4.92	64.74
Comparative Example 2	269	19	650	4.91	62.44
Example	255	19	650	4.92	66.01

According to Table 1, Table 2, and Fig. 5, the first electromagnetic wave absorption sheet 60, which is the amorphous sheet, and the second electromagnetic wave absorption sheet 70, which is a polymer sheet containing magnetic material, overlapped to form an electromagnetic wave absorption sheet. Compared with Comparative Example 1 including the electromagnetic wave shielding sheet formed of the amorphous sheet of a single layer and Comparative Example 2 including the electromagnetic wave shielding sheet formed of the polymer sheet of a single layer, the wireless charging efficiency was found to be the highest at 66.01%. It was.

In addition, in the embodiment of the present invention, the electromagnetic wave shielding sheet has a thickness of 0.11 mm in which the first electromagnetic wave absorbing sheet 60 and the second electromagnetic wave absorbing sheet 70 are combined, and the single layer electromagnetic waves of Comparative Examples 1 and 2 are used. Since the absorbent sheet is 0.15 mm, it was confirmed that the embodiment of the present invention is relatively high in wireless charging efficiency while having a smaller thickness as compared with Comparative Examples 1 and 2.

Accordingly, in the embodiment of the present invention, the thickness of the two antenna modules is the thinnest as 0.47t, and the thickness reduction effect is large.

Table 3 shows the characteristics of the antenna module of Table 1.

TABLE 3

division	NFC characteristics
	Communication distance (mm)					VPP (mV)
	C / E Mode		Reader Mode			EMV Load modulation Type A
	ACR	VIVO-pay	1K	4K	EV1	(0.0.0)	(1.0.0)	(2.0.0)	(3.0.0)
	ACR	VIVO-pay	1K	4K	EV1	8.8mV	7.2 mV	5.6 mV	4 mV
Comparative Example 1	28	39	30	29	17	41.17	30.75	14.18	4.74
Comparative Example 2	43	43	36	35	19	56.32	38.41	26.54	8.38
Example	42	42	36	36	19	38.25	26.28	19.38	7.26

According to Table 1 and Table 3, the communication distance of the Example of this invention is the longest compared with Comparative Example 1 and Comparative Example 2.

From this, it can be seen that forming two electromagnetic wave absorbing sheets by overlapping the heterogeneous first electromagnetic wave absorbing sheet 60 and the second electromagnetic wave absorbing sheet 70 increases the recognition distance for obtaining information.

Therefore, the present invention can be seen that the wireless charging performance is excellent while improving the NFC characteristics.

Since the present invention forms an antenna pattern for wireless communication and an antenna pattern for wireless charging, the antenna unit can implement both a short range wireless communication function and a wireless charging function, and overlaps the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet as an electromagnetic wave absorption sheet. This simplifies the assembly process, greatly reduces the appearance defect rate and improves the productivity.

In addition, the present invention is excellent in the electromagnetic wave absorption rate without increasing the thickness of the electromagnetic wave absorbing sheet, it is possible to reduce the size, slim and reduce the manufacturing cost.

In addition, the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet has different permeability and absorbs electromagnetic waves according to characteristics of each frequency band of the pattern, thereby improving operational reliability of the antenna module.

The present invention is not limited to the above-described embodiments, and various changes can be made without departing from the gist of the present invention, which is understood to be included in the configuration of the present invention.

Claims

An antenna unit;

A first electromagnetic wave absorption sheet disposed on one surface of the antenna unit;

An antenna module comprising a second electromagnetic wave absorbing sheet disposed at least partially overlapping one surface of the first electromagnetic wave absorbing sheet.
The method of claim 1,

And the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet have different permeability.
The method of claim 1,

And the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet are disposed between the antenna unit and a battery pack provided in the portable terminal.
The method of claim 1,

The antenna unit,

An antenna pattern for wireless communication for short range wireless communication;

Wireless charging antenna pattern for wireless charging;

The antenna module, characterized in that it comprises a substrate on which the antenna pattern for wireless communication and the antenna pattern for wireless charging is formed.
The method of claim 1,

And the first electromagnetic wave absorbing sheet and the second electromagnetic wave absorbing sheet are overlapped so that the entire front surface of one side can be covered by the front surface of the other side.
The method of claim 1,

And the first electromagnetic wave absorbing sheet and the second electromagnetic wave absorbing sheet have the same size and overlap each other so as to overlap each other.
The method of claim 1,

The antenna module, characterized in that any one of the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet to improve the wireless recognition performance, the other improves the performance of the wireless charging.
The method of claim 1,

The first electromagnetic wave absorbing sheet or the second electromagnetic wave absorbing sheet is one selected from carbon nanotubes including carbon nanotubes or carbon nanoparticles, amorphous sheets including amorphous alloys, polymer sheets containing magnetic powder, and ferrite sheets. An antenna module characterized in that.
The method of claim 1,

The first electromagnetic wave absorption sheet is any one of carbon nanotubes including carbon nanotubes or carbon nanoparticles, amorphous sheets including amorphous alloys, polymer sheets containing magnetic powder, and ferrite sheets.

The second electromagnetic wave absorbing sheet is any one of carbon nanotubes including carbon nanotubes or carbon nanoparticles, an amorphous sheet containing an amorphous alloy, a polymer sheet containing magnetic powder, and a ferrite sheet different from the first electromagnetic wave absorbing sheet. An antenna module, characterized in that.
The method of claim 1,

One of the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet is a polymer sheet containing magnetic powder, and the other of the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet is carbon nanotube or carbon nanoparticles. An antenna module comprising any one of carbon nanosheets, an amorphous sheet including an amorphous alloy, a polymer sheet containing magnetic powder, and a ferrite sheet.
A first electromagnetic wave absorption sheet; And

An electromagnetic wave absorbing sheet comprising a second electromagnetic wave absorbing sheet disposed at least partially overlapping one surface of the first electromagnetic wave absorbing sheet.
The method of claim 11,

The first electromagnetic wave absorbing sheet and the second electromagnetic wave absorbing sheet is characterized in that the magnetic permeability is different.
The method of claim 11,

And said first electromagnetic wave absorbing sheet and said second electromagnetic wave absorbing sheet are superposed so that the entire surface of one side may be covered by the entire surface of the other side.
The method of claim 11,

And said first electromagnetic wave absorbing sheet and said second electromagnetic wave absorbing sheet have the same size and overlap each other.
The method of claim 11,

The first electromagnetic wave absorbing sheet or the second electromagnetic wave absorbing sheet is one selected from carbon nanotubes including carbon nanotubes or carbon nanoparticles, amorphous sheets including amorphous alloys, polymer sheets containing magnetic powder, and ferrite sheets. Electromagnetic wave absorption sheet characterized in that.
The method of claim 11,

The first electromagnetic wave absorption sheet is any one of carbon nanotubes including carbon nanotubes or carbon nanoparticles, amorphous sheets including amorphous alloys, polymer sheets containing magnetic powder, and ferrite sheets.

The second electromagnetic wave absorbing sheet is any one of carbon nanotubes including carbon nanotubes or carbon nanoparticles, an amorphous sheet including an amorphous alloy, a polymer sheet containing magnetic powder, and a ferrite sheet different from the first electromagnetic wave absorbing sheet. Electromagnetic wave absorption sheet, characterized in that.
The method of claim 11,

Any one of the first electromagnetic wave absorption sheet and the second electromagnetic wave absorption sheet is a polymer sheet containing magnetic powder,

The other of the first electromagnetic wave absorbing sheet and the second electromagnetic wave absorbing sheet is a carbon nanosheet containing carbon nanotubes or carbon nanoparticles, an amorphous sheet containing an amorphous alloy, a polymer sheet containing magnetic powder, ferrite sheet Electromagnetic wave absorption sheet, characterized in that one.