Patent ID: 12191565

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, with reference to the accompanying drawings, the exemplary embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily practice the present invention. The present invention may be embodied in many different forms and is not limited to the exemplary embodiments described herein. In order to clearly describe the present invention in the drawings, parts that are irrelevant to the description are omitted, and the same reference numerals are assigned to the same or similar elements throughout the specification.

As illustrated inFIG.1, the magnetic field shielding sheet100for an antenna module according to one embodiment of the present invention includes a main shielding sheet110, a magnetic saturation-prevention member120and a protective film130.

Such a magnetic field shielding sheet100for an antenna module may be applied to antenna units210,210′,210″ including at least one magnet218for position alignment as illustrated inFIGS.4to7.

That is, when the magnetic field shielding sheet100for an antenna module according to one embodiment of the present invention constitutes an antenna module200together with antenna units210,210′,210″, it may be disposed on one surface of the antenna units210,210′,210″, and the magnetic saturation-prevention member120may be disposed at a position corresponding to the magnets218,218′ provided in the antenna units210,210′,210″.

Herein, the antenna units210,210′,210″ may include a circuit board212, at least one antenna214,216which is formed in a pattern on at least one surface of the circuit board212, and a magnet218for position alignment which is disposed on one surface of the circuit board212.

In this case, the at least one antenna214,216may perform a predetermined function in a non-contact manner by using a magnetic field in a predetermined frequency band, and the magnet218for position alignment may be disposed on one surface of the circuit board212so as not to overlap with the at least one antenna214,216.

In addition, the at least one antenna214,216may be provided with any one of an antenna for wireless power transfer for performing wireless power transmission, an NFC antenna for wireless communication and an MST antenna for magnetic security payment, or it may be configured by including two or more of the above-described antenna for wireless power transfer, NFC antenna and MST antenna.

Moreover, the antenna module200may be implemented as a wireless power transfer module, an NFC module, an MST module and the like, depending on the type of antennas214,216constituting the antenna units210,210′,210″.

The main shielding sheet110may be made of a material having magnetism to shield the magnetic field generated by the antenna units210,210′,210″.

For example, the main shielding sheet110may be composed of a ribbon sheet of an amorphous alloy or a nano-crystalline alloy, may be composed of a ferrite sheet or a polymer sheet, or may be composed in a mutually combined form of the ribbon sheet, ferrite sheet and polymer sheet.

In addition, the main shielding sheet110may be a multi-layer sheet in which a plurality of sheets are stacked in multiple layers via an adhesive layer, and the main shielding sheet110may be composed of a sheet which is separated into a plurality of pieces to increase overall resistance to suppress the generation of eddy current or to improve flexibility.

As a non-limiting example, the main shielding sheet110may be a sheet composed of a single layer of the ribbon sheet, ferrite sheet, polymer sheet and the like as illustrated inFIG.2.

Alternatively, the main shielding sheet110may be composed of a ribbon sheet111of an amorphous alloy or nano-crystalline alloy as illustrated inFIG.3, or it may be a multi-layer sheet in which a plurality of ribbon sheets111are stacked in multiple layers via an adhesive layer112, and each ribbon sheet111constituting the multi-layer sheet may be a sheet which is separately formed into a plurality of pieces.

However, the material of the main shielding sheet110is not limited thereto, and any known shielding sheet commonly used to shield a magnetic field may be applied thereto. Moreover, the main shielding sheet110may include at least one penetrating portion (not illustrated) that is formed through a predetermined length or a predetermined area so as to reduce the effect of eddy current while implementing high magnetic permeability.

When the antenna units210,210′,210″ include a magnet218for position alignment, the magnetic saturation-prevention member120may induce a DC magnetic field generated from the magnet218to prevent magnetic saturation of the main shielding sheet110by the DC magnetic field.

To this end, the magnetic saturation-prevention member120may be laminated on one surface of the main shielding sheet110, and it may be made of a material having magnetism to induce a DC magnetic field generated from the magnet218.

Moreover, the magnetic saturation-prevention member120may be provided to have a larger area than the cross-sectional area of the magnet218.

For example, the magnetic saturation-prevention member120may be laminated on one surface of the main shielding sheet110so as to be positioned at a position corresponding to the magnet218included in the antenna units210,210′,210″, or the magnetic saturation-prevention member120may be provided to correspond one-to-one to the magnets218included in the antenna units210,210′,210″, and the magnetic saturation-prevention member120may be provided to have a larger area than the cross-sectional area of the corresponding magnet218.

Specifically, the magnetic saturation-prevention member120may be disposed to correspond one-to-one to the magnet218which is disposed on one surface of the circuit board212between the circuit board212and the main shielding sheet110constituting the antenna units210,210′,210″.

That is, the magnetic saturation-prevention member120and the magnet218may be respectively disposed on both surfaces of the circuit board212constituting the antenna units210,210′,210″, and the magnetic saturation-prevention member120may be laminated on one surface of the main shielding sheet110so as to be positioned directly under the magnet218, and the magnetic saturation-prevention member120may be provided to have a larger cross-sectional area than the magnet218.

Accordingly, as illustrated inFIGS.4and5, when the magnetic field shielding sheet100according to one embodiment of the present invention constitutes an antenna module200together with an antenna unit210including a magnet218for position alignment, at least a part of the magnetic field of the DC magnetic field generated by the magnet218may be smoothly induced toward the magnetic saturation-prevention member120, and the DC magnetic field induced through the magnetic saturation-prevention member120may form a closed loop in the antenna module200through the magnet218and the magnetic saturation-prevention member120.

Through this, even if a DC magnetic field is generated in the magnet218, at least a part of the DC magnetic field generated in the magnet218is induced toward the magnetic saturation-prevention member120such that it may be blocked from moving toward the main shielding sheet110.

For this reason, the main shielding sheet110may prevent magnetic saturation due to the DC magnetic field generated by the magnet218, thereby preventing performance degradation due to magnetic saturation.

In this case, the magnetic saturation-prevention member120may be made of a material having a saturation magnetic flux density of 1.2 Tesla or more such that the saturation by a DC magnetic field induced by the magnet218can be prevented while having a thin thickness t2.

For example, the magnetic saturation-prevention member120may be composed of a ribbon sheet121of an amorphous alloy or a nano-crystalline alloy, and it may be provided to have a thickness t2 of ½ or less with respect to the thickness t1 of the main shielding sheet110.

Herein, when the magnetic saturation-prevention member120is composed of a ribbon sheet121of an amorphous alloy or a nano-crystalline alloy, the magnetic saturation-prevention member120may be composed of a single-layered ribbon sheet121, but as illustrated inFIGS.2and3, the magnetic saturation-prevention member120may be composed of a multi-layer sheet in which a plurality of ribbon sheets121are stacked via an adhesive layer122. Moreover, the ribbon sheet121may be a sheet which is formed separately into a plurality of pieces.

Through this, even if the magnetic saturation-prevention member120is laminated on one surface of the main shielding sheet110in the magnetic field shielding sheet100according to one embodiment of the present invention, it is possible to prevent magnetic saturation of the main shielding sheet110due to the DC magnetic field generated from the magnet218, while minimizing an increase in the total thickness of the magnetic field shielding sheet100.

However, the material of the magnetic saturation-prevention member120is not limited thereto, and if the saturation magnetic flux density is 1.2 Tesla or more, various known materials may be applied without limitation.

The protective film130may be attached to the main shielding sheet110via an adhesive layer133so as to cover an exposed surface of the main shielding sheet110.

For example, as illustrated inFIGS.1to3, the protective film130may include a first protective film131which covers an upper surface of the main shielding sheet110and a second protective film132which covers a lower surface of the main shielding sheet110.

In this case, the first protective film131may be attached to the upper surface of the main shielding sheet110so as to cover the exposed surface of the magnetic saturation-prevention member120which is laminated on the upper surface of the main shielding sheet110together with the upper surface of the main shielding sheet110.

Through this, the main shielding sheet110and the magnetic saturation-prevention member120may be protected from external force by preventing external exposure through the protective film130.

Further, in the magnetic field shielding sheet100for an antenna module according to one embodiment of the present invention, one surface of the main shielding sheet110and one surface of the magnetic saturation-prevention member120is simultaneously covered through the first protective film13, and thus, the possibility that the magnetic saturation-prevention member120is separated from the main shielding sheet110may be significantly reduced.

Herein, when the magnetic field shielding sheet100for an antenna module according to one embodiment of the present invention constitutes the antenna module200together with the antenna units210,210′,210″, any one of the first protective film131and the second protective film132may be removed such that the adhesive layer133is exposed to the outside so as to be attached to one surface of the antenna unit210,210′,210″.

For example, when the magnetic field shielding sheet100for an antenna module according to one embodiment of the present invention constitutes the antenna module200together with the antenna units210,210′,210″, the first protective film131may be removed, and one surface of the antenna units210,210′,210″ may be attached to the upper surface of the main shielding sheet110.

Through this, when the magnetic field shielding sheet100for an antenna module according to one embodiment of the present invention constitutes the antenna module200together with the antenna units210,210′,210″, the magnetic saturation-prevention member120may be disposed to be positioned between one surface of the antenna units210,210′,210″ and one surface of the main shielding sheet110.

Accordingly, even if the first protective film131covering one surface of the main shielding sheet110and the magnetic saturation-prevention member120at the same time is removed, the magnetic saturation-prevention member120may be positioned and fixed between one surface of the antenna units210,210′,210″ attached to each other and the main shield sheet110, thereby maintaining the correct position.

In this case, the protective film130may cover the upper and lower surfaces of the main shielding sheet110, respectively, but it may cover all exposed surfaces of the main shielding sheet110and the magnetic saturation-prevention member120.

That is, the protective film130may be attached to the main shielding sheet110so as to surround the side surfaces of the main shielding sheet110together with the upper and lower surfaces of the main shielding sheet110.

Specifically, as illustrated inFIGS.2and3, the first protective film131may cover all of the upper surface and part of the side surface of the main shielding sheet110and the side surface and the upper surface of the magnetic saturation-prevention member120, and the second protective film132may cover the lower surface of the main shielding sheet110and the side surface of the main shielding sheet110that is not covered by the first protective film131.

Through this, the magnetic field shielding sheet100according to one embodiment of the present invention may be configured in a form where the main shielding sheet110and the magnetic saturation-prevention member120are sealed inside the protective film130.

Accordingly, even if particles or powder are detached from the side surfaces of the main shielding sheet110and the magnetic saturation-prevention member120, the detached particles or powder may be fundamentally blocked from moving to other parts such as the antenna units210,210′,210″.

For this reason, even when the main shielding sheet110and/or the magnetic saturation-prevention member120is formed of a material including a metal component, the antenna units210,210′,210″ may be fundamentally prevented from being electrically shorted by the detached particles or powder.

Moreover, even if the main shielding sheet110and/or the magnetic saturation-prevention member120is composed of a sheet that is separated into a plurality of pieces, it is possible to fundamentally prevent some pieces from escaping to the outside.

The above-described magnetic shielding sheet100for an antenna module according to one embodiment of the present invention may be implemented as an antenna module200together with antenna units210,210′,210″ including an antenna214for wireless power transfer.

For example, as illustrated inFIGS.4and5, the antenna module200may include an antenna unit210including at least one antenna214,216which is formed in a pattern on at least one surface of the circuit board212and a magnet218for position alignment, and the above-described magnetic field shielding sheet100which is disposed on one surface of the antenna unit.

Herein, the antennas214,216may be configured as any one of an antenna for wireless power transfer, an NFC antenna and an MST antenna, or they may be configured in a combo type including two or more of an antenna for wireless power transfer, an NFC antenna and an MST antenna.

For example, as illustrated inFIGS.4,5and7, the antenna units210,210″ may be configured to include a first antenna214and a second antenna216which are formed in a pattern on a circuit board212, and at least one magnet218,218′ which is disposed on one surface of the circuit board212.

In this case, the first antenna214may be an antenna for wireless power transfer, and the second antenna216may be an NFC antenna, and the second antenna216may be formed on the circuit board212so as to surround the periphery of the first antenna214.

Herein, the antenna for wireless power transfer may be an antenna for wireless power reception that receives wireless power from a wireless power transmission module, or an antenna for wireless power transmission that transmits wireless power to the antenna for wireless power reception. That is, when the antenna units210,210′,210″ in the antenna module200include an antenna for wireless power transfer, the antenna module200may operate as a wireless power receiving module or a wireless power transmitting module depending on the role of the antenna for wireless power transfer.

As another example, as illustrated inFIG.6, the antenna unit210′ may be configured to include a first antenna214which is formed in a pattern on the circuit board212and at least one magnet218which is disposed on one surface of the circuit board212.

In this case, the first antenna214may perform any one function of an antenna for wireless power transfer, an NFC antenna and an MST antenna, and it may preferably perform a function of an antenna for wireless power transfer.

In this case, as described above, the magnetic field shielding sheet100may be attached to one surface of the circuit board212such that the magnetic saturation-prevention member120is disposed between the circuit board212and the main shielding sheet110.

Further, in the magnetic field shielding sheet100, the magnetic saturation-prevention member120may be provided to correspond one-to-one to at least one magnet218which is disposed on one surface of the circuit board212.

That is, the magnetic saturation-prevention member120and the magnet218may be respectively disposed on both surfaces of the circuit board212constituting the antenna units210,210′,210″, and the magnetic saturation-prevention member120may be disposed to be positioned directly under the magnet218, and the magnetic saturation-prevention member120may be provided to have a larger cross-sectional area than the magnet218.

Accordingly, at least a part of the magnetic field of the DC magnetic field generated by the magnet218may be smoothly induced toward the magnetic saturation-prevention member120, and the DC magnetic field induced through the magnetic saturation-prevention member120may form a closed loop inside the antenna module200through the magnet218and the magnetic saturation-prevention member120.

Through this, even if a DC magnetic field is generated in the magnet218, at least a part of the DC magnetic field generated in the magnet218is induced toward the magnetic saturation-prevention member120such that it is blocked from moving toward the main shielding sheet110.

For this reason, the main shielding sheet110may prevent magnetic saturation due to the DC magnetic field generated by the magnet218, thereby preventing performance degradation due to magnetic saturation.

Meanwhile, in the antenna module200according to one embodiment of the present invention, at least one magnet218′ included in the antenna unit210″ may be provided as a pair having different polarities.

That is, as illustrated inFIG.7, the antenna unit210″ may include at least one antenna214,216which is formed in a pattern on the circuit board212, and the magnet218′ which is disposed on one surface of the circuit board212may be provided in a pair having different polarities at respective positions corresponding to the magnetic saturation-prevention member120.

For example, a pair of magnets218′ having different polarities may be a first magnet218ahaving an N pole facing upward and a second magnet218bhaving an S pole facing upward inFIG.7.

Through this, when the antenna module200according to one embodiment of the present invention is aligned with other antenna module including a magnet for position alignment, the antenna module200according to one embodiment of the present invention may use any one of the magnets218a,218bamong the first magnet218aand the second magnet218bhaving different polarities to be smoothly aligned with the other antenna module, regardless of the polarity of the magnet for position alignment which is provided in the other antenna module.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the exemplary embodiments presented herein, and a person skilled in the art who understands the spirit of the present invention may easily suggest other exemplary embodiments by modifying, changing, deleting or adding components within the scope of the same spirit, but it can be said that this will also fall within the spirit of the present invention.