US-12627023-B2 - Heat dissipation sheet for low-frequency antenna, method for manufacturing same, and electronic device comprising same

Abstract

Disclosed is a heat dissipation sheet for a low frequency antenna. The heat dissipation sheet according to an embodiment of the present invention is a heat dissipation sheet for a low frequency antenna having an operating frequency of 50 kHz to 350 kHz, and is implemented by including a matrix and a heat dissipation filler dispersed in the matrix and having graphite. According to this, the heat generated from the antenna can be quickly transferred to the outside without deterioration of the characteristics of the antenna operating in the low frequency band, so that it can be widely applied to various articles in the industry, such as electronic devices.

Inventors

• Jin Hyoung LEE

Assignees

• AMOGREENTECH CO., LTD.

Dates

Publication Date

20260512

Application Date

20220504

Priority Date

20191106

Claims (11)

1. 1 . A heat dissipation sheet for a low frequency antenna which is disposed on a low frequency antenna with an operating frequency of 50 kHz to 350 kHz, the heat dissipation sheet for a low frequency antenna comprising: a matrix including a crosslinked rubber-based resin in which styrene-butadiene rubber is crosslinked with a crosslinking agent comprising at least one of a peroxide-based compound or an isocyanate-based compound; and a heat dissipation filler dispersed in the matrix and including graphite, wherein the heat dissipation filler is comprised at 80 to 92 wt % of a total weight of the heat dissipation sheet, wherein the heat dissipation filler comprises 1.0 to 4.0 parts by weight of an amino silane compound that modifies a surface of the heat dissipation filler based on 100 parts by weight of the heat dissipation filler, and the heat dissipation filler is surface-modified, and wherein the amino silane compound includes one or more non-epoxy silane compounds selected from the group consisting of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane and 3-aminopropylmethyldimethoxysilane.
2. 2 . The heat dissipation sheet for a low frequency antenna according to claim 1 , wherein the graphite is graphite flake.
3. 3 . The heat dissipation sheet for a low frequency antenna according to claim 1 , wherein the heat dissipation filler has an average particle diameter of 70 to 120 μm.
4. 4 . The heat dissipation sheet for a low frequency antenna according to claim 1 , wherein the matrix includes a crosslinked product in which styrene-butadiene rubber (SBR) is crosslinked with an isocyanate-based crosslinking agent, the graphite has a surface modified with an amino silane compound.
5. 5 . The heat dissipation sheet for a low frequency antenna according to claim 1 , wherein the heat dissipation sheet has a density of 1.7 g/m 3 or more.
6. 6 . The heat dissipation sheet for a low frequency antenna according to claim 1 , wherein the heat dissipation sheet has a surface resistance of 0.1 to 100Ω/□ and a thermal conductivity of 80 to 150 W/m□k.
7. 7 . A method for manufacturing a heat dissipation sheet for a low frequency antenna, comprising: preparing a surface-modified heat dissipation filler treated to contain 1.0 to 4.0 parts by weight of an amino silane compound based on 100 parts by weight of a heat dissipation filler including graphite, wherein the amino silane compound includes one or more non-epoxy silane compounds selected from the group consisting of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane and 3-aminopropylmethyldimethoxysilane; and preparing a preliminary sheet by mixing the surface-modified heat dissipation filler with a matrix forming component comprising a rubber-based resin comprising styrene-butadiene rubber (SBR) and a crosslinking agent comprising at least any one of a peroxide-based compound or an isocyanate-based compound; and pressurizing a prepared preliminary sheet and crosslinking a rubber-based resin to manufacture a heat dissipation sheet to form a matrix comprising a rubber-based resin in which styrene-butadiene rubber (SBR) is crosslinked, wherein the heat dissipation filler is comprised at 80 to 92 wt % of a total weight of the heat dissipation sheet.
8. 8 . The method for manufacturing a heat dissipation sheet for a low frequency antenna according to claim 7 , wherein the pressurizing the prepared preliminary sheet and the crosslinking a rubber-based resin comprises: crosslinking the preliminary sheet while applying heat and pressure at a temperature of 100 to 180° C.; and cooling the crosslinked preliminary sheet to a temperature of 18 to 60° C. while applying pressure.
9. 9 . A low frequency antenna module comprising: a low frequency antenna having an operating frequency of 50 kHz to 350 kHz; the heat dissipation sheet according to claim 1 ; and a magnetic field shielding sheet.
10. 10 . The low frequency antenna module according to claim 9 , wherein the low frequency antenna is disposed between the heat dissipation sheet and the magnetic field shielding sheet.
11. 11 . The low frequency antenna module according to claim 9 , wherein the lower frequency antenna module is a low frequency-reception antenna module which receives a wireless signal transmitted from a low frequency-transmission antenna having an operating frequency of 50 kHz to 350 kHz, wherein the low frequency antenna is a low frequency-reception antenna, and wherein the heat dissipation sheet is arranged to be disposed on a movement path of a wireless signal between the low frequency-transmission antenna and the low frequency-reception antenna.

Description

CROSS-REFERENCE TO RELATED APPLICATION This Application is a continuation of pending PCT International Application No. PCT/KR2020/015507, filed on Nov. 6, 2020, which claims priority to Korean Patent Application No. 10-2019-0141077, filed on Nov. 6, 2019, the entire contents of which are hereby incorporated by references in its entirety. TECHNICAL FIELD The present invention relates to a heat dissipation sheet, more particularly, to a heat dissipation sheet for low-frequency antenna, a method for manufacturing the same and an electronic device including the same. BACKGROUND ART Recently, as electronic devices become highly integrated with light, thin, short and multifunctional, heat generation increases, and countermeasures are required. In particular, dissipating the heat generated in electronic devices is very important because it is closely related to the reliability and longevity of the device. In the past, various heat radiation devices such as heat radiation fans, heat radiation fins, and heat pipes have been developed, and recently, various heat radiation composites such as heat radiation pads, heat dissipation sheets, and heat radiation paints added with fillers that express heat radiation performance in polymer materials have also been developed to assist or replace the heat radiation devices. However, materials known to have high heat radiation performance generally have low resistance and high dielectric constant, thereby degrading the performance of other parts in electronic devices to which the heat radiation composite is applied. For example, the heat radiation composite may block the electromagnetic wave transmitted from an antenna or the electromagnetic wave received by an antenna, so that there is a problem in that antenna performance is deteriorated or an intended function of the antenna is lost. Accordingly, there is an urgent need to develop a heat radiation material having excellent heat radiation characteristics while preventing degradation of components such as antennas. DISCLOSURE Technical Problem The present invention has been devised in view of the above points, and an object of the present invention is to provide a heat dissipation sheet for a low frequency antenna capable of rapidly transferring heat generated from an antenna to an outside without attenuating the characteristics of the antenna, particularly the antenna having a low frequency band as an operating frequency, and a method for manufacturing the same. In addition, another object of the present invention is to provide a heat dissipation sheet capable of minimizing or preventing the occurrence of cracks, shrinkage, and pores of the sheet even though it is designed to have excellent heat radiation performance, and having excellent flexibility to improve adhesion with an antenna, and a method for manufacturing the same. Further, another object of the present invention is to provide a heat dissipation sheet for a low frequency antenna having improved heat radiation performance by improving compatibility between dissimilar materials, and a method for manufacturing the same. Furthermore, another object of the present invention is to provide various industrial articles, such as electronic devices, in which, by having a heat dissipation sheet of the present invention, a low frequency antenna is operated with an initially designed operating efficiency as it is while preventing deterioration in function due to the heat generated by the low frequency antenna. Technical Solution In order to solve the above object, the present invention provides a heat dissipation sheet for a low frequency antenna which is disposed on a low frequency antenna with an operating frequency of 50 kHz to 350 kHz. The heat dissipation sheet for a low frequency antenna includes a matrix and a heat dissipation filler dispersed in the matrix and including graphite. According to an embodiment of the present invention, the matrix may include the rubber-based resin crosslinked by a crosslinking agent including one or more of a peroxide-based compound and an isocyanate-based compound. In addition, the rubber-based resin may include one or more selected from the group consisting of isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene propylene diene monomer (EPDM) rubber, acrylic rubber, nitrile-butadiene rubber (NBR) and silicone rubber. In addition, the rubber-based resin may be cross-linked by one or more crosslinking agents selected from the group consisting of an isocyanate-based resin and a peroxide-based resin. In addition, the heat dissipation filler may be provided at least 80% by weight of a total weight of the heat dissipation sheet. In addition, the graphite may have a surface modified with an amino silane compound. In this case, the amino silane compound may include one or more selected from the group consisting of 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane and 3-aminopropylmethyldimethoxysilane. In