Magnetic field shielding sheet, method for manufacturing magnetic field shielding sheet, and antenna module using same

1. A magnetic field shielding sheet comprising:

at least two thin film magnetic sheets, wherein each of the at least two thin film magnetic sheets is divided into a plurality of magnetic substance fragments;

an insulating layer formed on one side or both of the each of the at least two thin film magnetic sheets;

an adhesive layer formed between the insulating layers of the at least two thin film magnetic sheets to laminate and bond the at least two thin film magnetic sheets; and

a sealing portion covering both sides of the at least two thin film magnetic sheets, the insulating layer and the adhesive layer to prevent leakage into the magnetic field shielding sheet.

2. The magnetic field shielding sheet according to claim 1 , wherein the insulating layer penetrates spaces between the plurality of magnetic substance fragments.

3. The magnetic field shielding sheet according to claim 1 , wherein the at least two thin film magnetic field shielding sheets are in a strip shape.

4. The magnetic field shielding sheet according to claim 1 , wherein the each of the at least two thin film magnetic sheets has a thickness of 15 μm to 35 μm.

5. The magnetic field shielding sheet according to claim 1 , wherein the at least two thin film magnetic sheets are formed of a thin film magnetic substance including an amorphous alloy and a nanograin alloy.

6. The magnetic field shielding sheet according to claim 1 , wherein the adhesive layer is made of an acrylic adhesive and has a thickness of 5 μm or less.

7. The magnetic field shielding sheet according to claim 1 , wherein the insulating layer has a thickness of 5 μm or less.

8. The magnetic field shielding sheet of claim 7 , wherein the insulating layer includes an insulating layer formed of a composition containing a natural polymer compound and a synthetic polymer compound.

9. The magnetic field shielding sheet according to claim 1 , further comprising: a protective member and an adhesive member respectively attached to an upper surface and a lower surface of the magnetic field shielding sheet, wherein the adhesive member comprises: an adhesive layer attached to the lower surface; and a release film for protecting the adhesive layer until the magnetic field shielding sheet is attached to an adherend.

10. The magnetic field shielding sheet according to claim 1 , wherein the magnetic field shielding sheet is combined with an antenna module for wireless power transmission.

11. An antenna module for wireless power reception comprising:

an antenna configured to receive wireless power; and

a magnetic field shielding sheet disposed on one side of the antenna to improve antenna characteristics for wireless power reception and configured to focus magnetic flux toward the antenna,

wherein the magnetic field shielding sheet comprises:

at least two thin film magnetic sheets, wherein each of the at least two thin film magnetic sheet is divided into a plurality of magnetic substance fragments;

an insulating layer formed on one side or both of the each of the at least two thin film magnetic sheets;

an adhesive layer formed between the insulating layers of the at least two thin film magnetic sheets to laminate and bond the at least two thin film magnetic sheets; and

a sealing portion covering both sides of the at least two thin film magnetic sheet, the insulating layer and the adhesive layer to prevent leakage into the magnetic field shielding sheet.

12. A method of manufacturing a magnetic field shielding sheet, the method comprising:

manufacturing a thin film magnetic sheet wound in a roll form;

performing in-line heat treatment for the thin film magnetic sheet by using a heat treatment furnace to form a heat-treated thin film magnetic sheet in a roll form;

forming an insulating layer on one side or both sides of the heat-treated thin film magnetic sheet by using an insulator coating device to form an insulated thin film magnetic sheet in a roll form;

laminating the insulated thin film magnetic sheet to form a magnetic sheet laminate formed of multiple layers of the insulated thin film magnetic sheet;

sealing both sides of the magnetic sheet laminate; and

flake-treating the magnetic sheet laminate to divide the heat-treated thin film magnetic sheet into a plurality of magnetic substance fragments to form a flake-treated magnetic sheet laminate; wherein the laminating comprises: forming an adhesive layer between two neighboring layers of the insulated thin film magnetic sheet to bond the two neighboring layers of the insulated thin film magnetic sheet.

13. The method of manufacturing a magnetic field shielding sheet according to claim 12 , further comprising: laminating a temporary protection member on one side of the magnetic sheet laminate or the flake-treated magnetic sheet laminate.

14. The method of manufacturing a magnetic field shielding sheet according to claim 12 , further comprising: laminating a temporary protection member and an adhesive layer on both sides of the magnetic sheet laminate or the flake-treated magnetic sheet laminate.

15. The method of manufacturing a magnetic field shielding sheet according to claim 12 , further comprising: flattening the flake-treated magnetic sheet laminate and reducing a thickness of the flake-treated magnetic sheet laminate.