KR20140025215A - Thermal conductive adhesive comprising thermal conductive composite powder, thermal dissipation tape of thin film type comprising thereof and method of preparation the same - Google Patents

Abstract

The present invention relates to a thermal conductive adhesive including thermal conductive powder, a thin film type heat dissipation tape including the same, and a method for preparation the same. The thin film type heat dissipation tape of the present invention shows improved thermal conductivity and can be used in various fields such as highly integrated electronic products including smartphones.

Description

TECHNICAL FIELD [0001] The present invention relates to a thermally conductive adhesive containing a thermally conductive powder, a thin film type heat-radiating tape including the thermally conductive adhesive, and a method of manufacturing the same,

TECHNICAL FIELD The present invention relates to a thermally conductive adhesive containing a thermally conductive powder, a thin film type heat dissipation tape including the thermally conductive adhesive, and a method of manufacturing the same.

As the recent technology develops, the thickness of smart phones and TVs is becoming thinner, and accordingly, there is a growing demand for effective heat emission from the product. In particular, smart phones have become increasingly demanding to use high-performance central processing units (CPUs), and problems such as the need to effectively dissipate heat generated by the processor have become serious. To date, a sheet-type heat-radiating tape using a metal as a main heat-dissipating material has been used in order to satisfy such a heat radiation requirement. However, it is difficult to effectively dissipate heat due to the low thermal conductivity of the adhesive layer as compared with the high thermal conductivity of the metal foil piece. Thicker, thicker layers of smart phones, notebooks, and organic light emitting diode TVs (LED TVs) have become a stumbling block.

Currently, the structure of a general sheet type heat radiation tape which has been widely used in a smart phone or an organic light emitting diode (TV) TV is largely classified into a polymer film layer such as polyethylene terephthalate (PET) A metal thin plate layer such as copper or aluminum used, a heat source and an adhesive layer in direct contact with a heat sink, and the like.

Due to the structure of such a heat radiation tape, the thickness of the polymer film layer is not less than 20 占 퐉, the thickness of the metal foil layer is not less than 35 占 퐉, the adhesive layer is not less than 25 占 퐉, It has been very difficult to reduce the thickness of the adhesive layer for adhering the flaky layer to 10 mu m or more and to reduce the thickness to 100 mu m or less.

In order to solve this problem, a highly conductive material such as a graphite sheet has appeared. However, the thin film itself is not so difficult, and its role in the heat radiation tape is not greatly different from that of the metal thin plate. The manufacturing of the heat radiation tape is very difficult.

In order to solve these problems, the present invention has developed an adhesive layer capable of drastically improving the thermal conductivity by using a composite thermally conductive powder based on fine metal powders and carbon nanotubes as its main materials, And a method of manufacturing the same.

In order to achieve the above object, the present invention provides a method of manufacturing a semiconductor device, which increases the thermal conductivity of the adhesive layer so that the adhesive layer itself functions not only as a physical connection with a heat source and a heat sink, but also as a heat transfer path A thermally conductive adhesive tape, and a method of manufacturing the same.

The present invention also relates to a method of making a carbon nanotube comprising: (a) a thermally conductive powder comprising at least one metal layer plated and agglomerated in carbon nanotubes; And (b) an acrylic-based, urethane-based, silicone-based or rubber-based adhesive.

(A) a thermally conductive powder comprising a metal powder having at least one metal plated on its metal nucleus; And (b) an acrylic-based, urethane-based, silicone-based or rubber-based adhesive.

In the thermally conductive powder, the metal nucleus or the metal powder may be at least one metal selected from copper, silver, iron and aluminum, and the metal layer to be plated may be selected from the metal nucleus or metal powder and another metal. The metal to be plated may be at least one metal selected from copper, silver, iron and aluminum.

The present invention also relates to a method of manufacturing a metal thin film which is produced using a powdery thermally conductive material mainly composed of a fine metal powder produced from at least one metal atom prepared by an electroless plating method through a microfabrication method or an electroless plating method using metal nuclei as its main material A thin film type heat dissipation tape using a thermally conductive adhesive and a method of manufacturing the same.

In the present invention, the term "adhesive" is intended to include both an adhesive, an adhesive, or an adhesive and an adhesive.

In one embodiment of the present invention, in particular, the additive type thermally conductive powder can be used to perform a physical coupling with a heat source and a heat sink and a heat transfer path And a polymer film for reinforcing the physical properties of the thermally conductive adhesive.

The thermally conductive powder that can be used in the present invention may be prepared as a mixed phase of a plated form of fine metal powder or a highly conductive material such as carbon nanotubes or graphite as a main material thereof.

The fine metal powder that can be used in the present invention may be one or more kinds of metal hydrate aqueous solutions (hereinafter referred to as " aqueous solutions ") in emulsified phases composed of two or more kinds of fluids and surfactants in the microreaction method of suspension, A metal nugget obtained by reducing a metal through electroless plating or the like, or a fine metal powder in the form of one or more kinds of metals plated on one metal nug, or a fine metal powder obtained by such a fine metal powder or an artificially produced ferrite May be manufactured by a secondary plating method such as a reduction method by electroless plating method or the like using a metal powder of metal powder as a metal nucleus.

The performance enhancing additive which can be used in the present invention is a carbon nanotube or graphite and generally has a very high thermal conductivity per se. However, when it is used alone, it has problems due to self-agglomeration and flat structure, The improvement of the thermal conductivity of the substrate is not remarkable. However, when an appropriate amount of fine metal powder, carbon nanotube, or graphite is mixed, graphite or the like and metal fine powder may be connected to each other when mixed with a polymer material or a coating material, resulting in a high thermal conductivity.

In one embodiment of the present invention, the metal powder used for the thermally conductive adhesive may have an average diameter of 10 to 900 nm and an average longitudinal length of the carbon nanotube may be 0.5 to 10 μm.

In another embodiment of the present invention, an electroless plating process is performed from one kind of metal hydrate aqueous solution in an emulsified phase micro-reactor having a size of 1 to 100 mu m in diameter and composed of two or more fluids and interfacial materials commonly referred to as micro- , Or a fine metal powder in which at least one metal is sequentially plated on one metal nucleus, and a noble metal powder formed by naturally coagulating the metal noble metal powder Or carbon nanotube powder is mixed with the carbon nanotube powder in the above metal reduction and aggregation process, and the reduced fine metal powder is connected to the carbon nanotubes to aggregate the carbon nanotube fine metal powder as a natural aggregate. As a main material, fine metal powders or fine metal powder aggregates produced by the above methods, carbon nanotubes Tube fine metal powder agglomerates or fine metal powders such as ferrite easily obtainable from the market, as metal nuclei, from an aqueous solution of at least one metal hydrate by electroless plating or the like to form a fine The fine metal powder prepared by using metal powder as its main material or by adding carbon nanotube powder in the electroless plating process to cause micro-bonding between metal powder and carbon nanotube is used as its main material, A thermally conductive adhesive obtained by mixing an additive type thermally conductive powder prepared by mixing an appropriate amount of a high-conductivity material such as a carbon nanotube, graphite or conductive carbon black with a variety of adhesive resins such as an acrylic type, a urethane type, an epoxy type, and a rubber type, Alternatively, when the above-mentioned thermally conductive adhesive is produced, A thermally conductive adhesive made of polyethylene terephthalate (PET), polyethylene terephthalate (PET), or the like is prepared by mixing an appropriate amount of a coupling agent such as silane, titanate, or chromium in order to minimize interfacial separation of the powder, The present invention provides a thin film sheet-type heat radiation tape laminated or coated with a polymer film such as nylon, polypropylene (PP) or polycarbonate (PC) by a method such as a comma coating, a microcomma coating or a gravure coating and a manufacturing method thereof do.

In another embodiment of the present invention, in all of the above processes, the additive-type heat conduction component prepared by using the fine metal powder subjected to the secondary plating process using the magnetic fine metal powder such as ferrite as the metal nucleus in the production of the fine metal powder When a thermally conductive adhesive manufactured using a horse is laminated or coated on a polymer film by a comma coater or the like, an appropriate amount of magnetic field is applied to the opposite side of the polymer film, that is, the adhesive layer to orient the thermally conductive powder, Tape.

In one embodiment of the present invention, the thickness of the substrate layer may be 5 to 50 占 퐉 and the thickness of the thermally conductive adhesive layer may be 5 to 50 占 퐉 in the thin film heat radiation tape. Also, a release film may be adhered or laminated on one side or both sides of the thin film type heat radiation tape. In this case, the thickness of the release film may be 5 to 50 탆.

In another embodiment of the present invention, the thermally conductive powder of the present invention is mixed with an urethane-based, acrylic-based, urethane-based, silicone-based or rubber-based adhesive, and this is mixed with paper, polyethylene terephthalate It is possible to provide a thermally conductive tape in which a horizontal heat conduction layer is constituted by coating a substrate made of phthalate, nylon, high density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene or polycarbonate alone or a multilayer film based on the same, have.

There can be provided a thin film type heat radiation tape comprising an adhesive layer capable of remarkably improving the thermal conductivity of an adhesive layer using a composite type thermally conductive powder mainly composed of fine metal powder, carbon nanotube and the like according to the present invention as a main material. The thin film heat radiation tape of the present invention increases the thermal conductivity of the adhesive layer so that the adhesive layer itself can function not only as a physical bond with a heat source and a heat sink but also as a heat transfer path , The product itself is very smooth, and accordingly, the structure and design such as the thickness of the heat dissipator can be remarkably improved, so that it can be used in various fields such as being applied to a highly integrated electronic product such as a smart phone.

Hereinafter, the present invention will be described in more detail.

The following examples are provided for the purpose of further illustrating the present invention but are not to be construed as limiting the scope of the present invention.

< Example >

The thin-layer heat-radiating tape of this embodiment largely comprises a composite thermally conductive powder prepared by preparing a thermally conductive powder by the production of metal nuclei by a micro-reaction method, natural coagulation with carbon nanotubes, secondary plating and mixing with graphite, To prepare an adhesive layer.

Example 1-1.

Water 1 liter (L) of copper sulfate ^(CuSO. 5H ₂ O) aqueous solution of isopropyl alcohol and kerosene 200㎖ 100㎖, after producing an aqueous solution of copper sulfate dissolved in 10g _{(IPA, (CH 2) 3} CH 3 OH, FW 60.10 ) And 2 ml of sorbitan oleate (C ₂₄ H ₄₄ O ₆ , FW 428.62) were mixed, and the mixture was stirred for 30 minutes at 1000 rpm using a stirrer to obtain a metal hydrate oil image. 10 g of physicochemically pulverized carbon nanotubes were added to an aqueous solution of 0.5 g of sodium hydroxide (NaOH, FW = 40) dissolved in 50 g of water so as to have an average length of 0.1 탆 in the longitudinal direction, and then stirred at 50 rpm / To prepare a mixed solution of sodium hydroxide (NaOH, FW = 40) carbon nanotubes. The prepared sodium hydroxide (NaOH, FW = 40) carbon nanotube mixed solution was added to the metal hydrate oil image under stirring at 1000 rpm and further stirred for 10 minutes to obtain a metal hydrate oil image ready for reduction. Thereafter, a formaldehyde aqueous solution consisting of 5 g of formaldehyde (HCOH, FW = 30) and 65 g of water was prepared, and the mixture was stirred at a rate of 1 drop per second for 30 minutes to the metal hydroxide hydrate prepared for reduction. After the completion of the procedure, the precipitate was allowed to settle at room temperature for 1 hour, and then the solution was removed. Only the precipitate was thoroughly washed with ethanol and distilled water, and then dried to obtain a powder.

In the present embodiment, the above method is used to make metal nuclei agglomerated in carbon nanotubes for secondary plating. However, when two or more kinds of metal hydrides such as copper and silver, iron or copper are used in the micro-reactor, Metal powders composed of one kind of metal nuclei and one or more plated layers can be obtained according to the potential difference. When a proper amount of carbon nanotubes are added at the time of reduction, the fine metal powders naturally aggregate in the carbon nanotubes, A structure that can be improved can be obtained.

When the metal is reduced by the electroless plating method in the above-mentioned method, various kinds of metal hydrates can be used. According to the purpose, by using two kinds of metal hydrates of iron and copper, To obtain a plated fine metal powder, which may combine the properties of copper with conductivity and the properties of iron with magnetic properties.

Examples 1-2.

Next, the method of reducing the carbon nanotubes and the fine metal powder agglomerated thereon by the second electroless plating method using the aqueous solution of the metal hydrate is as follows. The powder prepared by the above method was put into an aqueous solution of silver nitrate composed of 100 g of water and 1 g of silver nitrate (AgNO, FW = 169.87), and was well mixed for 10 minutes at 100 revolutions per minute using a magnetic bar. An aqueous solution consisting of 100 g of water, 0.1 g of sodium hydroxide (NaOH, FW = 40) and 0.1 g of anhydrous sodium carbonate (NaCO, FW = 106) was further mixed for 5 minutes. Then, a formaldehyde aqueous solution consisting of 5 g of formaldehyde (HCOH, FW = 30) and 65 g of water was added to the solution containing the metal powder under stirring at a rate of 0.1 drop per second and stirred for 10 minutes. After all the process was completed, the precipitate was washed with ethanol and distilled water for 10 hours at room temperature, and then dried to obtain a plated fine metal powder.

Examples 1-3.

Next, 60 parts by weight (%) of the plated fine metal powder prepared by the above method and 40 parts by weight (%) of the conductive graphite having an average particle size size of 1 mu m were mixed and then, using a ball mill having a diameter of 5 mu m, And pulverized to obtain an addition type heat conductive powder.

Examples 1-4.

The following example describes the production of a thermally conductive adhesive using the above-mentioned thermally conductive powder.

29.65 g of a polyurethane adhesive having a solids content of 50% and a viscosity of 100,000 cps at 25 캜 and 2.97 g of a curing agent having a solids content of 70% and a viscosity of 3,000 cps at 25 캜 were mixed with 62.2 g of toluene using an agitator After mixing for 1 minute at a speed of 500 rpm, 5.18 g of the above-mentioned thermally conductive powder was added and further mixed for 3 minutes to obtain a thermally conductive adhesive.

Examples 1-5.

The thermally conductive adhesive was applied to a PET base film having a thickness of 12 占 퐉, which had been subjected to a surface treatment using a corona, using an applicator using an applicator. The thermally conductive adhesive was applied in a multistage process in a temperature range of 90 占 폚 to 120 占 폚, And then the thickness of the adhesive solidified except for the base film was 38 mu m to prepare the thin film heat-radiating tape of the present invention.

The resultant thin film type heat radiation tape was measured by a laser flesh in-plane (ASTM E 1461) method and showed a very good thermal conductivity of 135 W / mK.

Example 2-1.

Water 1 liter (L) of copper sulfate ^(CuSO. 5H ₂ O) 200g of an aqueous solution obtained by dissolving 200㎖ 1000㎖ and kerosene, isopropyl alcohol after producing a copper sulfate aqueous solution _{(IPA, (CH 2) 3} CH 3 OH, FW 60.10 ) And 50 ml of sorbitan oleate (C ₂₄ H ₄₄ O ₆ , FW 428.62) were mixed and stirred for 10 minutes at 7000 rpm using a stirrer to obtain a metal hydrate oil image. Then, 1 g of physicochemically pulverized carbon nanotubes was added to an aqueous solution of 7 g of sodium hydroxide (NaOH, FW = 40) dissolved in 50 g of water to have an average length of 10 m in the longitudinal direction, and then the mixture was stirred at 50 rpm And stirred to prepare a mixed solution of sodium hydroxide (NaOH, FW = 40) carbon nanotubes. The prepared sodium hydroxide (NaOH, FW = 40) carbon nanotube mixed solution was added to the metal hydrate oil image under stirring at 7000 rpm and further stirred for 30 minutes to obtain a metal hydrate oil image ready for reduction. Then, a formaldehyde aqueous solution consisting of 50 g of formaldehyde (HCOH, FW = 30) and 65 g of water was prepared, and the mixture was stirred for 5 minutes at a rate of 10 drops per second to the metal hydroxide hydrate prepared for reduction. After the completion of all the steps, the precipitate was allowed to stand at room temperature for 10 hours, and then the solution was removed. Only the precipitate was thoroughly washed with ethanol and distilled water, and then dried to obtain a powder.

Example 2-2.

The powder prepared by the method of Example 2-1 was placed in an aqueous solution of silver nitrate composed of 100 g of water and 10 g of silver nitrate (AgNO, FW = 169.87) and mixed well at 2000 revolutions per minute for 1 minute using a magnetic bar. An aqueous solution consisting of 100 g of water, 5 g of sodium hydroxide (NaOH, FW = 40) and 5 g of anhydrous sodium carbonate (NaCO, FW = 106) was further mixed for 5 minutes. Then, a formaldehyde aqueous solution consisting of 50 g of formaldehyde (HCOH, FW = 30) and 65 g of water was added to the solution containing the metal powder under stirring at a rate of 10 drops per second and stirred for 10 minutes. After all the process was completed, the precipitate was washed with ethanol and distilled water for 10 hours at room temperature, and then dried to obtain a plated fine metal powder.

Examples 2-3.

Next, 95 parts by weight (%) of the plated fine metal powder prepared by the above-mentioned method and 5 parts by weight (%) of the conductive graphite having an average particle size size of 6 탆 were mixed and then, using a ball mill having a diameter of 5 탆, And pulverized for 1 hour to obtain an addition type heat conductive powder.

Examples 2-4.

The following example describes the production of a thermally conductive adhesive using the above-mentioned thermally conductive powder.

29.65 g of a polyurethane adhesive having a solids content of 50% and a viscosity of 100,000 cps at 25 캜 and 2.97 g of a curing agent having a solids content of 70% and a viscosity of 3,000 cps at 25 캜 were mixed with 62.2 g of toluene using an agitator After mixing for 1 minute at a speed of 500 rpm, 5.18 g of the above-mentioned thermally conductive powder was added and further mixed for 3 minutes to obtain a thermally conductive adhesive.

Examples 2-5.

The thermally conductive adhesive was applied to a PET base film having a thickness of 12 占 퐉, which had been subjected to a surface treatment using a corona, using an applicator using an applicator. The thermally conductive adhesive was applied in a multistage process in a temperature range of 90 占 폚 to 120 占 폚, And then the thickness of the adhesive solidified except for the base film was 38 mu m to prepare the thin film heat-radiating tape of the present invention.

The resultant thin film type heat radiation tape was measured by a laser flesh in-plane (ASTM E 1461) method and showed a very good thermal conductivity of 170 W / mK.

Claims (12)

(a) a thermally conductive powder comprising one or more metal layers plated and agglomerated with carbon nanotubes; And
(b) A thermally conductive adhesive comprising at least one adhesive selected from the group consisting of acrylic, urethane, silicone or rubber. (a) a thermally conductive powder comprising a metal powder in which at least one metal is plated on a metal core; And
(b) A thermally conductive adhesive comprising at least one adhesive selected from the group consisting of acrylic, urethane, silicone or rubber. The thermally conductive adhesive according to claim 1 or 2, wherein the thermally conductive powder further comprises conductive graphite. The thermally conductive adhesive according to claim 2, wherein the metal core is prepared by reducing metal from one or more aqueous metal hydrate solutions in an emulsified phase comprising a fluid and a surfactant in which two or more phases are separated, or a natural aggregate thereof. Stirring a mixture containing a fluid, an interface material, and a metal hydrate in which two or more phases are separated to obtain a metal hydride oil image;
Dispersing the carbon nanotubes in the metal hydride oil image to obtain a metal powder agglomerated in the carbon nanotubes;
Plating at least one metal on the metal powder agglomerated in the carbon nanotubes;
Adding the plated metal powder to at least one adhesive selected from the group consisting of an acrylic type, a urethane type, a silicone type and a rubber type. Thin film type heat-radiating tape, wherein the thermally conductive adhesive according to claim 1 is coated or laminated on a base film layer. Thin film type heat-radiating tape, wherein the thermally conductive adhesive according to claim 2 is coated or laminated on the base film layer. A thermally conductive powder comprising a metal powder plated with at least one metal layer and agglomerated on carbon nanotubes, a thermally conductive powder comprising a metal powder with at least one metal plated on a metal core, or both. Adhesive layer; And
Thin film type heat-radiating tape comprising at least one base film layer formed of at least one polymer resin selected from paper, polyethylene terephthalate (PET), nylon, high density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene and polycarbonate. The thin film type heat dissipation tape according to any one of claims 6 to 8, wherein the heat conductive adhesive layer has a thickness of 5 to 50 µm and the base film layer has a thickness of 5 to 50 µm. The thin film type heat-radiating tape according to any one of claims 6 to 8, wherein the release film is further laminated on the thermally conductive adhesive layer and the release film has a thickness of 5 to 50 µm. A thermally conductive powder comprising a metal powder plated with at least one metal layer and agglomerated on carbon nanotubes, a thermally conductive powder comprising a metal powder with at least one metal plated on a metal core, or both. Thin film thermal radiation comprising coating or laminating an adhesive layer to one or more base film layers formed of one or more polymer resins selected from paper, polyethylene terephthalate, nylon, high density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, and polycarbonate Method of Making Tapes. A thermally conductive powder comprising a metal powder plated with at least one metal layer and agglomerated on carbon nanotubes, a thermally conductive powder comprising a metal powder with at least one metal plated on a metal core, or both. Coating or laminating the adhesive layer to one or more base film layers selected from paper, polyethylene terephthalate, nylon, high density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, and polycarbonate, and then curing them to form a horizontal heat conducting layer. Method of manufacturing a thin film type heat radiation tape.