KR101856666B1 - Heatsink for LED and fabrication method thereof - Google Patents

Abstract

The present invention relates to a heat radiation member for an LED and a manufacturing method thereof. More specifically, the present invention relates to a heat radiation member for an LED which has uniform dispersibility by mixing the heat radiation member with oxide metal and a surface-modified carbon nanotube, and depositing the mixture, has excellent attachment due to improved solution stability and improved adhesion, and has excellent thermal conductivity and excellent heat radiation performance, and a manufacturing method thereof.

Description

Technical Field [0001] The present invention relates to a heat dissipating member for LED,

The present invention relates to a heat dissipating member for an LED having excellent heat dissipation characteristics including surface-modified carbon nanotubes and a method of manufacturing the same.

LED (Light Emitting Diode) is a semiconductor device that emits light by injecting a current into a compound. It can save up to 90% of energy by converting electric energy into light energy, thus replacing incandescent and fluorescent lamps with low energy efficiency. It is attracting attention as next generation light source which can do. Recently, LEDs are being used in various fields such as lighting devices, mobile phones, automobile head lamps, and projectors. However, since LED has a characteristic of consuming power by heat, the higher the power applied to the LED light source in order to increase the light output of the LED, the higher the heat generated by the device becomes, and the efficiency becomes lower. There is a problem that the temperature of the device rises and the efficient light emission is inhibited, and the lifetime is rapidly lowered due to thermal stress. As a result, heat dissipation technology, which is a very important factor that determines the performance and lifetime of the LED, has been studied in order to minimize the heat generated by the LED and effectively conduct it.

Generally, heat-radiating materials are composite materials made by adding high thermal conductive fillers such as carbon or ceramics to easily processable polymers, and they can impart properties of metals and inorganic materials while maintaining diversity. However, in the case of polymer composite materials, metal is used for high thermal conductivity and a large amount of filler load is required, which makes the processing difficult and hinders the physical properties of the product. Therefore, carbon nanotubes with high thermal conductivity have recently attracted great interest as next generation heat dissipation materials.

For example, Korean Patent Registration No. 10-1495052 discloses an LED lamp apparatus including a carbon nanotube and an LED lamp apparatus having an excellent heat dissipation property. The LED lamp apparatus includes a heat-transfer coating layer containing carbon nanotubes and a heat- have. Korean Patent No. 10-1295715 discloses a heat radiation coating composition for reflector and cover coating of a lighting fixture comprising a binder, a conductive inorganic substance and a diluent.

However, in the case of the prior art, carbon nanotubes are not easy to be dispersed due to the inherent van der Waals force, and because of the high contact resistance and photon scattering which are proportional to the surface area expanded inside the thermally conductive composite, There is a problem that the thermal conductivity value is low.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a heat dissipating member for LED having improved dispersibility and excellent heat dissipation property through surface modification of carbon nanotubes.

According to an aspect of the present invention,

There is provided a heat dissipating member for an LED comprising a carbon nanotube surface-modified with a compound represented by the following formula (1), a polymer resin, and a coating layer on which a metal oxide is dispersed and deposited.

Wherein R is any one selected from the group consisting of COOH, B (OH) ₂ , OH, NH ₂ and SH, and n is an integer of 0 to 20.

The carbon nanotube may be a single-walled carbon nanotube, a double-walled carbon nanotube, or a multi-walled carbon nanotube. The polymeric resin may be at least one selected from the group consisting of an epoxy resin, an acrylic resin, a polycarbonate resin, and a polypropylene resin And the metal oxide is MgO, MgO ₂ or Al ₂ O ₃ .

The thickness of the coating layer is 10 to 80 占 퐉, and the metal thin film is aluminum, iron, copper, magnesium, silicon carbide, nickel, zinc, silver, tin, tungsten or an alloy thereof. The metal thin film may further include a plurality of radiating fins, wherein the radiating fin is aluminum, iron, copper, magnesium, silicon carbide, nickel, zinc, silver, tin, tungsten or an alloy thereof. Further, a paint layer may be further laminated on the coating layer. It is preferable that the painted layer is laminated for finishing in order to harmonize the aesthetics of the product and the overall color of the lighting apparatus, and the thickness thereof is suitably from 0.1 탆 to 1 탆.

The compound represented by Formula 1 may have an antibacterial and deodorizing effect by surface modification.

In another aspect, the present invention provides a lighting apparatus including the heat radiation member for LED.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: depositing a coating material containing carbon nanotubes, a polymer resin, and a metal oxide surface-modified with a compound represented by Formula 1 on a surface of a radiation member; And drying or heating the injected heat dissipating member. The present invention also provides a method of manufacturing a heat dissipating member for an LED.

According to the present invention, since the heat dissipating member is formed by mixing the surface-modified carbon nanotubes with the metal oxide and depositing them, it is easy to disperse and has good stability of solution, high adhesion and excellent adhesion, There is an effect that the heat radiation member can be manufactured. Further, the surface-modified carbon nanotube of the present invention is excellent in electromagnetic wave shielding effect, so that harmful electromagnetic waves can be avoided by being applied to electric, electronic devices, communication devices, household goods, and building products. The surface-modified carbon nanotubes of the present invention may additionally have an antibacterial effect in addition to a heat radiation effect when used as a radiation member of an LED lighting device.

1 is a schematic view showing a process for producing a surface-modified carbon nanotube containing a metal oxide.
2 shows a state in which carbon nanotubes, a polymer resin and a metal oxide are dispersed.
3 is an SEM image of a surface of the heat radiation member for LED modified with (a) the carbon nanotube modified with the formula (1) and (b) the coating layer according to the present invention.
4 is a graph showing the heat dissipation property of the heat dissipating member.
5 shows a lighting device to which a heat radiation member is applied.

Hereinafter, a heat dissipating member for an LED and a method of manufacturing the same according to the present invention will be described in detail.

The present invention provides a heat dissipating member for an LED comprising a carbon nanotube surface-modified with a compound represented by the following formula (1), a polymer resin, and a coating layer on which a metal oxide is dispersed and deposited on the metal thin film.

Wherein R is any one selected from the group consisting of COOH, B (OH) ₂ , OH, NH ₂ and SH, and n is an integer of 0 to 20.

The carbon nanotubes are single-walled carbon nanotubes, double-walled carbon nanotubes, or multi-walled carbon nanotubes.

The polymer resin acts as a binder to improve the adhesive strength and is preferably at least one selected from the group consisting of epoxy resin, acrylic resin, polycarbonate resin and polypropylene resin. Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, alkylphenol novolak type epoxy resin, bisphenol type epoxy resin, (Meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, isobutyl (meth) acrylate, Acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, hydroxypropyl (Meth) acrylate, and the like, but are not limited thereto. Examples of the polycarbonate resin include polycyclohexanedimethylene terephthalate glycol and polyethylene terephthalate glycol. Examples of the polypropylene resin include semi-homopolypropylene, high-crystalline polypropylene copolymer, high-crystal block polypropylene copolymer , Random copolypropylene, and butyl tertiary polypropylene terpolymers.

The metal oxide is MgO, MgO ₂ or Al ₂ O _3. By using the metal oxide, the heat conductivity and the heat resistance are improved and the heat radiation property is further improved.

The thickness of the coating layer is 10 to 80 占 퐉, and the metal thin film is aluminum, iron, copper, magnesium, silicon carbide, nickel, zinc, silver, tin, tungsten or an alloy thereof. Further, the metal thin film may further include a plurality of heat dissipating fins for increasing the surface area and increasing the heat transfer efficiency. The heat dissipating fins may include aluminum, iron, copper, magnesium, silicon carbide, nickel, zinc, silver, tin, tungsten, Alloy.

Further, a paint layer may be further laminated on the coating layer.

In another aspect, the present invention provides a lighting apparatus including the heat radiation member for LED.

An example of a heat dissipating member for a LED and a lighting apparatus including the same according to the present invention is as follows.

As shown in FIG. 5, the lighting apparatus to which the present invention is applied includes an LED substrate 140 having one or more LED elements 130 mounted thereon, And a heat dissipating member (110).

The LED substrate 140 may have any configuration as long as at least one LED element 130 such as a PCB, an FPCB, and a metal PCB can be installed as a substrate on which one or more LED elements 130 for illumination are installed.

Here, the LED element 130 is an LED element for illumination, and various LED elements can be used depending on applications such as white light, further red light, green light, and blue light.

The heat dissipating member 110 may be combined with the LED substrate 140 to dissipate heat generated from the LED device 130, and may have various configurations according to heat dissipation characteristics.

For example, the heat dissipating member 110 may include a main body 111 coupled with the LED substrate 140, and a plurality of heat dissipating fins 112 for enhancing the heat dissipation effect, such as aluminum or aluminum alloy, .

Here, the object to be surface-modified by the composition according to the present invention including carbon nanotubes is preferably a heat dissipating member 110.

Meanwhile, in the illumination device to which the present invention is applied, one or more lenses (not shown) may be installed on the LED substrate 140 to improve the illumination characteristic of the light emitted from the LED device 130.

In addition, a transparent cover member (not shown) may be installed to protect the LED substrate 140 on which the LED device 130 is installed from the outside.

In addition, the illumination device to which the present invention is applied may include a housing (not shown) for protecting the LED substrate 140 and the like together with the heat dissipating member 110.

Here, the housing may also be an object whose surface is modified by the composition according to the present invention including carbon nanotubes.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: depositing a coating material containing carbon nanotubes, a polymer resin, and a metal oxide surface-modified with a compound represented by Formula 1 on a surface of a heat dissipating member; And drying or heating the injected heat dissipating member 110. The present invention also provides a method of manufacturing a heat dissipating member for an LED.

At this time, the coating material may be in the form of powder or solution, and may further include a solvent, a dispersion stabilizer and a curing agent.

The solvent is used for uniform dispersibility and is preferably used in a group consisting of water, an alcohol solvent, a ketone solvent, an amine solvent, an ester solvent, an amide solvent, a halogenated hydrocarbon solvent, an ether solvent and a furan solvent And may include at least one kind selected.

The dispersion stabilizer may be triton-x, a cellulose dispersant, or a polyvinyl dispersant. Examples of the cellulose-based dispersing agent include alkyl hydroxypropyl cellulose ether, hydroxypropyl methyl cellulose, carboxymethyl cellulose and hydroxyethyl cellulose, and the polyvinyl dispersant includes polyvinyl pyrrolidone, polyvinyl alcohol and poly Vinyl butyral.

The curing agent is added for rapid curing and may be any one selected from an amine curing agent, an imidazole curing agent, and an acid anhydride curing agent. For example, the amine-based curing agent includes benzyldimethylamine, triethanolamine, triethyltetramine, diethylenetriamine, triethylenamine, dimethylaminoethanol, and the imidazole-based curing agent includes imidazole, isoimidazole Methylimidazole, 2-methylimidazole, butylimidazole, 2-heptadecenyl-4-methylimidazole, 2-undecenylimidazole, 2-methylimidazole, 1-propyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, and the like. Examples of the acid anhydride-based curing agent include phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, methyl nadic anhydride, nadic anhydride, And ropthalic anhydride.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples are intended to illustrate the present invention, and the scope of the present invention is not limited thereto.

Manufacturing example . Carbon nanotube surface modification

The surface modification of the carbon nanotubes is performed by the following reaction formula.

First, the carbon nanotube powder was added to a mixed solution of sulfuric acid and nitric acid in a volume ratio of 3: 1, and the mixture was ultrasonicated and dispersed at room temperature for 2 hours, and then the temperature was cooled to room temperature. After filtration, the solution was washed with a large amount of distilled water, washed until the pH of the filtrate became neutral, and then dried.

1-1) In the formula 1, R is NH ₂ If

1,4-phenylene diamine (0.01 mol) was dissolved in 20 ml of 0.22 M HCl aqueous solution, and 20 ml of NaNO ₂ (0.011 mol) was slowly added thereto in an ice bath. After the addition of sodium tetrafluoroborate (0.01 M), the reaction was completed and then dried to obtain the diazonium salt. 2 g of the diazonium salt, K ₂ S ₂ O ₈ 0.08 g of the dried carbon nanotubes, 0.4 g of the dried carbon nanotubes, and 320 ml of distilled water were mixed, stirred at 85 ° C for 12 hours, and dried to obtain carbon nanotubes whose surface was modified.

1-2) In the above formula (1), R is COOH  Occation

4-aminobenzoic acid (0.01 mol) was dissolved in 20 ml of 0.22 M HCl aqueous solution, and 20 ml of NaNO ₂ (0.011 mol) was slowly added thereto in an ice bath. After the addition of sodium tetrafluoroborate (0.01 M), the reaction was completed and then dried to obtain the diazonium salt. The diazonium salt (2 g), Azobisisobutyronitrile 0.3 g of the dried carbon nanotubes, 0.4 g of the dried carbon nanotubes, and 80 ml of acetonitrile were mixed and stirred at 60 ° C for 7 hours with nitrogen, followed by drying to obtain the surface-modified carbon nanotubes.

Example  1 to 6. Heat radiation member manufacture

The surface-modified carbon nanotubes, the metal oxide, the polymer resin, and the solvent were mixed and stirred for 3 hours according to the following Table 1. The dispersion stabilizer and the amine curing agent were added and stirred for 2 hours, The coating material was deposited on the surface of the metal thin film of the iron material to a thickness of 20 to 30 μm and then dried. FIG. 1 shows a surface modified carbon nanotube containing a metal oxide, and FIG. 2 shows a coating material in the form of a solution according to an embodiment of the present invention.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Carbon nanotube R = NH ₂ 23 23 25 - - - R = COOH - - - 23 25 25 Metal oxide (MgO ₂ ) 14 17 14 14 13 17 Polymer resin (bisphenol A type epoxy resin) 35 32 33 25 32 32 The dispersion stabilizer (Triton X-100) 20 18 20 16 16 18 Solvent (methyl ethyl ketone: toluene = 1: 1 (v / v)) 31 33 31 45 37 31 Curing agent (polypropylene glycol diamine) 2 2 2 2 2 2

<Unit: gram (g)>

Comparative Example  One

20 parts by weight of ordinary carbon nanotubes whose surfaces were not modified, 12 parts by weight of metal oxide, 26 parts by weight of a polymer resin, 14 parts by weight of a dispersion stabilizer, 26 parts by weight of a solvent and 2 parts by weight of an amine- To a thickness of 20 to 30 [mu] m, followed by drying.

Test Example  One. SEM  Character rating

The coating material according to the present invention was evaluated with a scanning electron microscope (SEM), which is shown in Fig. As shown in FIG. 3, (a) is a carbon nanotube having a surface bound to Formula 1, (b) is a surface of a modified carbon nanotube having a metal oxide bound thereto, It can be seen that the metal oxide is uniformly dispersed on the surface, and it is confirmed that the surface has been successfully modified.

Test Example  2. Thermal test

LEDs were mounted on Examples 1 to 6 and Comparative Example 1, and a thermocouple was attached to measure temperature changes with time. The power was supplied at 20 W, which is shown in Table 2 and FIG.

Temperature over time (℃) 10 minutes 30 minutes 1 hours 4 hours Example 1 50 51 51 55 Example 2 51 52 52 55 Example 3 51 51 52 56 Example 4 50 51 52 55 Example 5 52 53 54 57 Example 6 51 52 53 56 Comparative Example 1 57 60 64 69

As shown in Table 2, it can be seen that Examples 1 and 2 including the surface modified carbon nanotubes have a lower temperature change after a lapse of time compared to a carbon nanotube whose surface has not been modified. It was confirmed that Examples 1 to 6 were well dispersed and exhibited excellent heat radiation performance.

Test Example  3. Attachment  Test

In order to test the adhesiveness, in Examples 1 to 6 and Comparative Example 1, a line was drawn at intervals of 5 mm in length and width to form a total of 100 squares, and then the tape was peeled off to evaluate the adhesion with the remaining number of squares . Adhesion was excellent when not peeled off, good when peeled less than 5%, and poor when peeled off more than 5%.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Attachment Great Great Great Good Great Great Bad

As shown in Table 3, it was confirmed that the coating layers of Examples 1 to 6 were not peeled off even after peeling off the tape, so that they were excellent or good. As a result, it was confirmed that the surface was more excellent in adhesion than the unmodified carbon nanotubes.

Test Example  4. Stability test

In order to test the solution stability, a coating material was prepared according to the composition shown in Table 1, and the coating material was allowed to stand in a thermostatic chamber at 60 ± 2 ° C. for 3 weeks, and the state of the solution was visually observed and evaluated. When the solution did not undergo interlayer separation and viscosity did not rise, it was evaluated as bad when the viscosity of the solution was increased and when the change such as delamination occurred.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Attachment Good Good Good Good Good Good Bad

As shown in Table 4, in Examples 1 to 6, it was confirmed that the solution maintained its initial state even after 3 weeks, indicating that the stability was excellent.

The foregoing description is merely illustrative of the present invention, and various modifications may be made without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed herein are intended to be illustrative rather than limiting, and the spirit and scope of the present invention are not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all techniques within the scope of the same should be construed as being included in the scope of the present invention.

110:
120: heat sink fin
130: LED chip
140: printed circuit board

Claims (12)

And a coating layer on which a carbon nanotube surface-modified with a compound represented by the following formula (1), a polymer resin, and a metal oxide are dispersed and deposited on the metal thin film,
The polymer resin is at least one selected from the group consisting of an epoxy resin, an acrylic resin, a polycarbonate resin and a polypropylene resin,
Wherein the metal oxide is MgO, MgO ₂ or Al ₂ O ₃ .

Wherein R is any one selected from the group consisting of COOH, B (OH) ₂ , OH, NH ₂ and SH, and n is an integer of 0 to 20.
The LED according to claim 1, wherein the carbon nanotube is a single-walled carbon nanotube, a double-walled carbon nanotube, or a multi-walled carbon nanotube.
delete delete The LED according to claim 1, wherein the coating layer has a thickness of 10 to 80 占 퐉,
The heat dissipating member for LED according to claim 1, wherein the metal thin film is aluminum, iron, copper, magnesium, silicon carbide, nickel, zinc, silver, tin, tungsten,
The heat dissipating member for LED according to claim 1, wherein the metal thin film further comprises a plurality of heat dissipating fins
The heat dissipating member for LED according to claim 7, wherein the heat radiating fin is aluminum, iron, copper, magnesium, silicon carbide, nickel, zinc, silver, tin, tungsten,
The heat dissipating member for LED according to claim 1, wherein a paint layer is further laminated on the coating layer
The method according to claim 1,
A compound represented by the above formula (1) has antibacterial and deodorizing effect by surface modification.
A lighting device comprising the heat-radiating member for LED according to any one of claims 1, 2, and 10 to 10
1) a carbon nanotube surface-modified with a compound represented by the following formula (1)
Epoxy resin; Acrylic resin; Polycarbonate resin; And a polypropylene resin, and a metal oxide such as MgO, MgO ₂ or Al ₂ O _{3 on the} surface of the exoergic member, and
2) A method of manufacturing a heat dissipating member for an LED comprising the step of drying or heating the heat dissipating member

Wherein R is any one selected from the group consisting of COOH, B (OH) ₂ , OH, NH ₂ and SH, and n is an integer of 0 to 20.

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