Coil component

Patent metadata

Field	Value
Publication number	US-11250986-B2
Application number	US-201716303593-A
Country	US
Kind code	B2
Filing date	May 24, 2017
Priority date	May 24, 2016
Publication date	Feb 15, 2022
Grant date	Feb 15, 2022

Abstract

A coil component having a magnetic core, a bobbin accommodating the magnetic core, and at least one pair of coils wound around the outer part of the bobbin. The bobbin is implemented as a heat radiating member comprising: a polymer matrix; and graphite-nano metal composites which are provided in a plurality, are dispersed on the polymer matrix, and have nano-metal particles bonded to the surface of graphite. Accordingly, the heat generated from a coil component due to an applied current can most quickly and efficiently be conducted and radiated outside, and thus degrading of common-mode-noise rejection function is prevented and a differential signal can substantially be passed without attenuation. In addition, in spite of the heat generated from the coil component or external physical and chemical stimulation, heat radiating properties can last for a long time.

First claim

The invention claimed is:

1. A coil component comprising:
a magnetic core; a bobbin configured to accommodate the magnetic core; and at least one pair of coils wound outside the bobbin,
wherein the bobbin is a heat radiation member which includes a polymer matrix and a plurality of graphite-nano metal composites which are dispersed on the polymer matrix, and each include nano metal particles bonded to a surface of graphite,
an insulating heat radiation coating layer formed of an insulating heat radiation coating composition on an outer surface of the bobbin,
wherein the insulating heat radiation coating layer is formed by treating an insulating heat radiation coating composition on the outer surface of the bobbin, wherein the insulating heat radiation coating composition includes a coating layer-forming component including a main resin and an insulating heat radiation filler,
wherein the insulating heat radiation coating composition has a heat radiation efficiency of 30% or more according to a thermal radiation evaluation method below:
[Heat radiation evaluation method]
after a heat source having a surface area of 4 cm 2 and a temperature of 88° C. is placed to be in contact with a lower center of specimen 1 which includes a 25-μm thick insulating heat radiation coating layer formed by treating an insulating heat radiation coating composition on an upper surface of an aluminum plate having a thickness of 1.5 mm and an area of 35 mm×34 mm in a closed system having a temperature of 25° C. and a humidity of 50%, temperature is measured at an upper point located 5 cm from a center of a heat radiation unit, temperature is measured in the same manner solely on specimen 2, that is, an aluminum plate on which a heat radiation coating layer is not formed, and a heat radiation efficiency is measured according to Expression 1 below:
heat radiation efficiency (%)={(temperature (° C.) of upper point located 5 cm from center of specimen 1)/(temperature (° C.) of upper point located 5 cm from center of specimen 2)−1}×100   [Expression 1].

2. The coil component of claim 1 , wherein the nano metal particles are crystallized nanoparticles, and the graphite-nano metal composite further includes a polydopamine layer coated on the nano metal particles so as to improve an interfacial property between the polymer matrix and the graphite-nano metal composite.

3. The coil component of claim 1 , wherein the graphite-nano metal composite is included in an amount of 10-95 wt % in the heat radiation member.

4. The coil component of claim 1 , wherein the heat radiation member further includes an insulating film on an outer surface thereof that is made of at least one polymer component selected from the group consisting of polyethylene, polypropylene, polystyrene, polyvinyl chloride, a polyacrylonitrile resin, acrylonitrile-butadiene-styrene (ABS), styrene-acrylonitrile (SAN), an acrylic-based resin, a methacrylic-based resin, polyamide, polyester, polycarbonate, polyphenylene sulfide, polyamideimide, polyvinyl butyral, polyvinyl formal, polyhydroxy polyether, polyether, polypthalamide, a phenoxy resin, polyurethane, a nitrile butadiene resin, a urea-based resin (UF), a melamine-based resin (MF), an unsaturated polyester resin (UP), an epoxy resin, and a silicon resin.

5. The coil component of claim 1 , wherein the insulating heat radiation coating layer is coated on the at least one pair of coils wound outside the bobbin.

6. The coil component of claim 1 , further comprising a thermal interface material which fills an empty space in the bobbin accommodating the magnetic core.

7. The coil component of claim 1 , wherein the main resin is a curable resin, and the coating layer-forming component further includes a curing agent included in an amount of 25-100 parts by weight with respect to 100 parts by weight of the main resin.

8. The coil component of claim 1 , wherein the insulating heat radiation filler is included in an amount of 25-70 parts by weight with respect to 100 parts by weight of the main resin.

9. The coil component of claim 1 , wherein the insulating heat radiation filler includes silicon carbide.

10. The coil component of claim 1 , wherein the insulating heat radiation filler has an average particle diameter of 10 nm to 15 μm.

11. The coil component of claim 10 , wherein a D50 to D97 ratio of the insulating heat radiation filler is less than or equal to 1:4.5, and wherein D50 and D97 are particle diameters of the insulating heat radiation filler when cumulative degrees in a volume accumulated particle size distribution are 50% and 97%, respectively.

12. A coil component comprising:
a magnetic core; a bobbin configured to accommodate the magnetic core; and at least one pair of coils wound outside the bobbin,
wherein the bobbin is a heat radiation member which includes a polymer matrix and a plurality of graphite-nano metal composites which are dispersed on the polymer matrix, and each include nano metal particles bonded to a surface of graphite,
an insulating heat radiation coating layer formed of an insulating heat radiation coating composition on an outer surface of the bobbin,
wherein the insulating heat radiation coating layer is formed by treating an insulating heat radiation coating composition on the outer surface of the bobbin, wherein the insulating heat radiation coating composition includes a coating layer-forming component including a main resin and an insulating heat radiation filler, wherein the main resin includes a compound represented by Formula 1 below:

wherein R 1 and R2 are each independently a hydrogen atom, a C 1 -C 5 linear alkyl group, or a C 3 -C 5 branched alkyl group, and R 3 and R 4 are each independently a hydrogen atom, a C 1 -C 5 linear alkyl group, or a C 3 -C 5 branched alkyl group, and n is a rational number which allows a weight average molecular weight of the compound represented by Formula 1 to be in a range of 400 to 4,000.

13. The coil component of claim 12 , wherein the insulating heat radiation filler:
a) includes silicon carbide;
b) has an average particle diameter of 10 nm to 15 μm; or
c) both.

14. A coil component comprising:
a magnetic core; a bobbin configured to accommodate the magnetic core; and at least one pair of coils wound outside the bobbin,
wherein the bobbin is a heat radiation member which includes a polymer matrix and a plurality of graphite-nano metal composites which are dispersed on the polymer matrix, and each include nano metal particles bonded to a surface of graphite,
an insulating heat radiation coating layer formed of an insulating heat radiation coating composition on an outer surface of the bobbin,

wherein the insulating heat radiation coating layer is formed by treating an insulating heat radiation coating composition on the outer surface of the bobbin, wherein the insulating heat radiation coating composition includes a coating layer-forming component including a main resin and an insulating heat radiation filler, wherein the main resin is a curable resin, and the coating layer-forming component further includes a curing agent included in an amount of 25-100 parts by weight with respect to 100 parts by weight of the main resin, wherein the curing agent includes a first curing agent and a second curing agent in a weight ratio of 1:0.5 to 1:1.5, wherein the first curing agent includes an aliphatic polyamine-based curing agent and the second curing agent includes at least one selected from the group consisting of an aromatic polyamine-based curing

Assignees

• Amogreentech Co Ltd

Inventors

• Hwang Seung Jae
• Kim Moon Hoe
• Hwang Moon Young

Classifications

• H01F27/2876 Primary

  Cooling (cooling transformers and inductances in general H01F27/08) · CPC title

• H01F27/28

  Coils; Windings; Conductive connections · CPC title

• H01F27/32

  Insulating of coils, windings, or parts thereof · CPC title

• C09K5/14

  Solid materials, e.g. powdery or granular · CPC title

• C09D7/40

  Additives · CPC title