Electromagnetic wave shielding sheet for antenna, method for manufacturing same, antenna comprising same, and battery pack for portable terminal having said antenna
The present invention relates to an electromagnetic wave shielding sheet for an antenna, to a method for manufacturing same, to an antenna comprising same, and to a battery pack for a portable terminal having said antenna. The method for manufacturing the electromagnetic wave shielding sheet for the antenna may reduce a frequency variation, provide a heat-dissipating function, and prevent peel-off. The method comprises: a step of preparing a ferrite sheet; and step of placing a heat-dissipating layer on one side of the ferrite sheet. The present invention has advantages in that the adhesive forces of the ferrite sheet and the heat-dissipating layer are excellent and the heat-dissipating effects are excellent, the electromagnetic wave shielding sheet can be applied to various antenna products, and the frequency variation can be reduced when the antenna having the electromagnetic wave shielding sheet is mounted on the battery pack.
1. An electromagnetic wave shielding sheet for an antenna, comprising:
a ferrite sheet;
a heat dissipating layer attached to one side of the ferrite sheet; and
an adhesive layer between the ferrite sheet and the heat-dissipating layer via which the heat-dissipating layer is attached to the ferrite sheet,
wherein the adhesive layer comprises an acryl-based adhesive,
wherein the adhesive contains Ag and Ni powders in an amount of 10˜30 volume %, based on a total volume thereof, so that the adhesive can function as a thermal conductor.
2. The electromagnetic wave shielding sheet of claim 1 , wherein the heat-dissipating layer is a metal layer.
3. The electromagnetic wave shielding sheet of claim 2 , wherein the metal layer is made of at least one selected from among copper, silver, gold, and aluminum.
4. The electromagnetic wave shielding sheet of claim 1 , wherein the heat-dissipating layer has a thickness of more than 0 μm, and 10 μm or less.
5. The electromagnetic wave shielding sheet of claim 1 , wherein the heat-dissipating layer is formed on a substrate at one side thereof and is attached to the ferrite sheet at an opposite side thereof via an adhesive, the substrate being applied to the antenna.
6. The electromagnetic wave shielding sheet of claim 5 , wherein the substrate is a PET film or a PI film.
7. The electromagnetic wave shielding sheet of claim 1 , further comprising a Cu—Ti seed layer between the ferrite sheet and the heat-dissipating layer to increase bonding strength between the ferrite sheet and the heat-dissipating layer.
8. A method for manufacturing an electromagnetic wave shielding sheet for an antenna, comprising:
preparing a ferrite sheet; and
bonding a heat-dissipating layer to one side of the ferrite sheet,
wherein the bonding step comprises:
forming an adhesive on one side of the ferrite sheet; and
disposing the heat-dissipating layer on the adhesive,
wherein the adhesive comprises an acryl-based adhesive,
wherein the adhesive contains Ag and Ni powders in an amount of 10˜30volume %, based on a total volume thereof, so that the adhesive can function as a thermal conductor.
9. The method of claim 8 , wherein the bonding step comprises:
depositing a metal on one side of a substrate to form the heat-dissipating layer;
applying the adhesive to the heat-dissipating layer; and
attaching the heat-dissipating layer to the ferrite sheet via the adhesive to form a multilayer structure composed of the ferrite sheet, the adhesive, the heat-dissipating layer and the substrate in sequence.
10. The method of claim 9 , wherein the substrate is a PET film or a PI film.
11. The method of claim 8 , wherein the heat-dissipating layer is a metal layer.
12. The method of claim 11 , wherein the metal layer is made of at least one selected from among copper, silver, gold, and aluminum.
13. The method of claim 8 , wherein the heat-dissipating layer is formed by bonding a copper foil to one side of the ferrite sheet via the adhesive.
14. The method of claim 8 , wherein the heat-dissipating layer is integrated into the ferrite sheet using a process selected from among vacuum deposition, chemical vapor deposition, and electroplating.