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

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.

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.