JP5577553B2 - Heat dissipation compound composition - Google Patents

Description

  The present invention relates to a heat dissipation compound composition having high thermal conductivity, and relates to a heat-resistant heat dissipation compound composition excellent in thermal oxidation stability.

Among the semiconductor parts used in electronic devices, there are parts that generate heat during use, such as power supply control power modules such as computer CPUs, Peltier elements, LEDs, and inverters.
In order to protect these semiconductor components from heat and to function normally, there is a method of conducting the generated heat to heat dissipation components such as a heat spreader and a heat sink to dissipate heat. The heat-dissipating compound composition is applied between the semiconductor component and the heat-dissipating component so as to be in close contact with each other, and is used to efficiently conduct heat of the semiconductor component to the heat-dissipating component.
In recent years, the performance improvement of electronic devices using these semiconductor components and the implementation of small and high-density packaging have been rapidly progressing, and the amount of heat generated by semiconductors has increased. Therefore, a heat dissipation compound composition used for such heat dissipation measures has been developed. In addition to high thermal conductivity, the composition itself is required to have heat resistance.

The heat-dissipating compound composition includes hydrocarbon synthetic oils, ester oils, ether oils, silicone oils, fluorine oils and other base oils, metal oxides such as zinc oxide and aluminum oxide, boron nitride, silicon nitride, aluminum nitride, etc. A grease-like composition in which a large amount of a filler having a high thermal conductivity, such as inorganic nitrides, metal powders such as aluminum, silver, and copper, is dispersed. For example, a lubricant containing a thickener blended with a thermally conductive filler (Patent Document 1), a hydrocarbon oil or a fluorine oil blended with a specific thermally conductive inorganic filler (Patent Document 2) Also known are those in which aluminum nitride surface-treated with a specific organosilane is blended in a base oil such as silicone oil (Patent Document 3), and those in which a specific surface modifier is blended (Patent Documents 4 and 5). ing.
In addition, an inorganic filler, a base oil, a metal soap composed of a divalent or higher-valent metal ion and an organic acid, and an amine-based antioxidant (Patent Document 6) have also been proposed.

JP 3-106996 Japanese Patent No. 2938428 Japanese Patent No. 2930298 JP 2006-210437 A JP 2006-96973 A JP 2009-46639 A

The heat-dissipating compound composition is used for a thermal contact interface in a cooling mechanism such as a CPU of a computer or a cooling mechanism such as a power module used in a high-power inverter mounted on a hybrid vehicle or an electric vehicle. In recent years, semiconductor elements in these electronic devices have increased in heat generation density and heat generation with downsizing and higher performance, and heat dissipation compound compositions are exposed to higher temperatures than ever before. Further, it is often used in an automobile engine room under a higher temperature environment.
When the heat dissipation compound composition is used for a long time in such a high temperature environment, the consistency may be greatly lowered depending on the type of the heat dissipation compound composition. As described above, when the consistency of the heat dissipation material is significantly reduced during use, cracks, voids, oil separation, and the like may occur, resulting in a reduction in heat dissipation performance.
Therefore, a heat-dissipating compound composition that is used over a long period of time in a situation where the heat generation temperature of the semiconductor unit and the ambient environmental temperature reach a high temperature is required to have a low rate of change in consistency at high temperatures and to have excellent heat resistance. It has been.
An object of the present invention is to provide a heat dissipation compound composition having excellent heat resistance at high temperatures.

  As a result of intensive studies to achieve the above-mentioned problems, the inventors have a composition in which a base oil and an inorganic filler whose surface is treated with a coupling agent are blended at a specific ratio, and the thermal conductivity is high. It has been found that it has an appropriate consistency and is excellent in oil resistance and heat resistance, and has completed the present invention.

The present invention provides the following heat dissipation compound composition.
1. (A) 2 to 20 parts by mass of a base oil, and (B) a heat dissipation compound composition containing 80 to 98 parts by mass of an inorganic filler whose surface is treated with a coupling agent ,
A heat dissipation compound composition, wherein the coupling agent is at least one selected from the group consisting of neopentyl (diallyl) oxytri (dioctyl) phosphate zirconate and isopropoxy titanium stearate .
2. (A) The heat dissipation compound composition as described in 1 above, wherein the base oil is at least one selected from the group consisting of hydrocarbon-based synthetic oils, ether-based synthetic oils, and ester-based synthetic oils.
3 . 3. The heat dissipation compound composition according to 1 or 2 above, wherein the inorganic filler (B) is at least one selected from the group consisting of metal oxides, metal nitrides, boron nitrides, and metal powders.
4 . The inorganic filler (B) is a mixture having an average particle diameter of (a) 0.8 μm or less and (b) 1 to 5 μm, but a mass ratio of 2: 8 to 8: 2. The heat-dissipating compound composition according to any one of the above items 1 to 3 , which is characterized in that it exists.
5 . 5. The heat-dissipating compound composition as described in any one of 1 to 4 above, which contains 0.01 to 2.0 parts by mass of a metal deactivator as the component (C).
6 . The metal deactivator (C) is composed of a benzotriazole derivative, a benzimidazole derivative, a dimercaptothiazole derivative, an oxyquinoline derivative, a salicylidene derivative, a thiocarbamate compound, a piperidine compound, a salicylic acid compound, and a thiophosphate compound. 6. The heat dissipation compound composition according to any one of 1 to 5 above, which is at least one selected from the group consisting of:

  The heat-dissipating compound composition of the present invention has a high thermal conductivity, an appropriate consistency, and is excellent in oil separation resistance and heat resistance. For this reason, the heat dissipation compound composition of this invention can improve the heat dissipation of the electronic component which emits high heat, and can be used suitably as a heat dissipation material of the power module for motor vehicles and LED exposed to a high temperature environment especially.

As the base oil used in the composition of the present invention, various base oils can be used, for example, hydrocarbon oils such as mineral oil and synthetic hydrocarbon oil, ester oils, ether oils, phosphate esters, silicone oils and fluorine oils. Hydrocarbon oil, ester oil, and ether oil are preferable. A base oil may be used individually by 1 type, or may be used in combination of 2 or more type.
As mineral oil, for example, a mineral oil-based lubricating oil fraction is refined by appropriately combining purification methods such as solvent extraction, solvent dewaxing, hydrorefining, hydrocracking, wax isomerization, 150 neutral oil, 500 neutral Oil, bright stock, and high viscosity index base oil. The mineral oil is preferably a highly hydrorefined high viscosity index base oil.
Examples of the synthetic hydrocarbon oil include those obtained by polymerizing α-olefins produced by using ethylene, propylene, butene, and derivatives thereof as a raw material alone or in combination of two or more. As an alpha olefin, a C6-C14 thing is mentioned preferably.
Specifically, poly α-olefin (PAO) obtained by polymerizing linear α-olefin, polyisobutylene which is a polymer of isobutylene, ethylene, a copolymer of propylene and α-olefin, and the like can be mentioned. . Moreover, alkylbenzene, alkylnaphthalene, etc. can also be used.

Examples of ester oils include diesters and polyol esters.
Examples of the diester include esters of dibasic acids such as adipic acid, azelaic acid, sebacic acid, and dodecanedioic acid. As the dibasic acid, an aliphatic dibasic acid having 4 to 36 carbon atoms is preferable. The alcohol residue constituting the ester portion is preferably a monohydric alcohol residue having 4 to 26 carbon atoms.
The polyol ester is an ester of neopentyl polyol in which a hydrogen atom does not exist on the β-position carbon, and specifically includes carboxylic acid esters such as neopentyl glycol, trimethylolpropane, and pentaerythritol. The carboxylic acid residue constituting the ester part is preferably a monocarboxylic acid residue having 4 to 26 carbon atoms.
In addition to the above, aliphatic dihydric alcohols such as ethylene glycol, propylene glycol, butylene glycol, 2-butyl-2-ethylpropanediol, and 2,4-diethyl-pentanediol, and linear or branched chain saturation Esters with fatty acids can also be used. As the linear or branched saturated fatty acid, a monovalent linear or branched saturated fatty acid having 4 to 30 carbon atoms is preferable.
Furthermore, carbonate ester can also be used.

Examples of the ether oil include polyglycol and (poly) phenyl ether.
Examples of the polyglycol include polyethylene glycol, polypropylene glycol, and derivatives thereof.
Examples of (poly) phenyl ether include alkylated diphenyl ether, monoalkylated tetraphenyl ether, dialkylated tetraphenyl ether, and pentaphenyl ether.
Examples of phosphate esters include triethyl phosphate, tributyl phosphate, triphenyl phosphate, tricresyl phosphate, and trixylenyl phosphate.

  Since the heat dissipation compound composition is applied to the heat generating portion, it is exposed to a high temperature for a long time. For this reason, it is desirable that the base oil has excellent thermal oxidation stability. Among the above base oils, synthetic oils are preferable, and synthetic hydrocarbon oils, ester oils, and ether oils are preferable. Among these base oils, those having particularly excellent thermal oxidation stability include poly α-olefins for synthetic hydrocarbon oils, polyol esters for ester oils, and alkyl diphenyl ethers for ether oils as preferred base oils. Furthermore, among these base oils, poly α-olefins and polyol esters that can be prepared with a heat dissipation compound composition that has a relatively high viscosity index and that is soft and excellent in coating properties when a heat dissipation compound composition is prepared are used as preferred base oils. . Moreover, when the especially outstanding coating property is not calculated | required, a high viscosity alkyl diphenyl ether and (poly) phenyl ether can also be used.

The kinematic viscosity of the base oil is preferably 10mm ² / s~600mm ² / s at 40 ° C.. It is preferable to set the kinematic viscosity at 40 ° C. to 10 mm ² / s or more because evaporation of base oil and oil separation at high temperatures tend to be suppressed. Moreover, since it becomes easy to obtain a suitable consistency by making kinematic viscosity in 40 degreeC 600mm < ² > / s or less, it is preferable.

Particularly preferred base oil is at least one selected from the group consisting of hydrocarbon-based synthetic oils, ether-based synthetic oils, and ester-based synthetic oils. More specifically, poly-α-olefins, copolymers of ethylene and α-olefins, hydrocarbon synthetic oils such as alkylnaphthalene and alkylbenzene, alkyl diphenyl ethers, diesters, triesters, tetraesters, polyhydric alcohols and fatty acids. Examples include synthetic esters such as synthetic esters obtained by dehydration condensation.
The content of the (A) base oil is 2 to 20 parts by mass, preferably 3 to 15 parts by mass, particularly 100 parts by mass of the total amount of the components (A), (B) and (C) of the present invention. Preferably it is 3-10 mass parts. When the amount exceeds 20 parts by mass, the heat dissipation compound composition may flow out when it is too soft and placed in a high temperature environment. Further, oil separation occurs and the desired thermal conductivity cannot be obtained. Moreover, if it is less than 2 mass parts, it will become hard and will not be able to maintain sufficient applicability, or cannot be prepared as a heat-radiation compound composition.

  The inorganic filler used in the present invention is not particularly limited as long as it has a thermal conductivity higher than that of the base oil, but powders such as metal oxides, inorganic nitrides, metals, silicon compounds, and carbon materials are preferably used. It is done. One kind of the inorganic filler of the present invention may be used, or two or more kinds may be used in combination.

  When the above-mentioned inorganic fillers are required to have electrical insulation, powders of non-conductive materials such as zinc oxide, aluminum oxide, titanium oxide, aluminum nitride, boron nitride, silicon carbide, and silica can be suitably used. Zinc oxide, aluminum oxide, aluminum nitride, boron nitride, and silicon carbide powder are more preferable, and zinc oxide and aluminum oxide powder are particularly preferable. These inorganic fillers may be used alone or in combination of two or more. In addition, when seeking higher thermal conductivity without requiring electrical insulation, metal powders such as zinc, aluminum, gold, silver, and copper, and carbon materials such as graphite, fullerene, carbon nanotubes, carbon nanohorns, and diamonds Powders can be suitably used, metal powders are more preferred, and zinc or aluminum powders are particularly preferred. Further, a metal powder or a carbon material powder can be used in combination with the above-mentioned non-conductive substance powder.

The inorganic filler is preferably an inorganic powder having an average particle diameter of 1 μm or less when only fine particles are used.
Moreover, when combining a fine grain and a coarse grain, although an average particle diameter is (a) 0.8 micrometer or less and (b) 1-5 micrometers, a mass ratio becomes like this. Preferably it is 2: 8-8. : 2, more preferably 35:65 to 65:35. By combining fine particles and coarse particles in this way, the filling rate of the inorganic filler can be increased, and there is an effect of improving the thermal conductivity.

(B) Content of an inorganic filler is 80-98 mass parts when the total amount of the component (A) and (B) of this invention is 100 mass parts, Preferably it is 85.0-98 mass parts.
The higher the content of the inorganic filler, the better the thermal conductivity. If it is less than 80 parts by mass, the thermal conductivity may be low or the oil may be easily removed. On the other hand, if it exceeds 98 parts by mass, it becomes hard and sufficient coating properties cannot be maintained, or a heat dissipation compound composition cannot be prepared.
The inorganic filler used in the present invention is obtained by treating the surface with a coupling agent in advance.

The surface treatment coupling agent is preferably at least one selected from the group consisting of an aluminum coupling agent, a zirconium coupling agent, and a titanate coupling agent.
Specific examples of aluminum coupling agents include acetoalkoxyaluminum diisopropylate, and specific examples of zirconium coupling agents include neopentyl (diallyl) oxytri (dioctyl) phosphate zirconate, titanate coupling agents. Specific examples of these include isopropoxytitanium stearate.
With respect to 100 parts by mass of the inorganic filler used in the present invention, the coupling agent is preferably 0.1 to 3 parts by mass, more preferably 0.3 to 2 parts by mass by a general coupling agent treatment method. By doing so, an inorganic filler whose surface is treated with a coupling agent is obtained. The method for the surface coupling treatment of the inorganic filler is not limited, and any method may be used. For example, while forcibly stirring the filler with a blender, mixer, etc., a dry method typified by a method in which the coupling agent is processed directly or by spraying a solution diluted with an organic solvent with dry air or nitrogen gas, There is a wet method in which a filler is added to a dilute solution of a coupling agent to form a slurry or to immerse directly.

(C) Metal deactivator used as an optional component in the composition of the present invention includes benzotriazole derivatives, benzimidazole derivatives, dimercaptothiazole derivatives, oxyquinoline derivatives, salicylidene derivatives, thiocarbamate compounds, piperidine compounds , A salicylic acid compound, and at least one selected from the group consisting of thiophosphate compounds. Such metal deactivators are described, for example, in CMC Technical Library 177 “Development of Petroleum Product Additives”, pages 77-82.
(C) The content of the metal deactivator is preferably 0.01 to 2.0 parts by mass when the total amount of the components (A), (B) and (C) of the present invention is 100 parts by mass. More preferably, it is 0.02-0.5 mass part.
If the content of the metal deactivator is less than 0.01 parts by mass, the material to which the compound composition is applied may be corroded, and even if the content exceeds 2.0 parts by mass, a remarkable difference appears in the effect. Absent.

Antioxidants, such as phenolic antioxidants and amine antioxidants, can be added as optional components to the composition of the present invention.
Examples of phenolic antioxidants include 2,6 di-t-butyl-4-methylphenol, n-octadecyl-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate, Tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane or the like is preferably used. Examples of amine-based antioxidants include naphthylamines such as phenyl-α-naphthylamine and phenyl-β-naphthylamine, (alkylated) diphenylamines such as p, p′-dialkyldiphenylamine, diphenyl-p-phenylenediamine, and dipyridylamines. Phenothiazines and the like are preferably used. Of these, naphthylamines and alkylated diphenylamines, which are highly oil-soluble and hardly generate sludge, are preferred, and alkylated diphenylamines are particularly preferred.
Naphthylamines may not have an alkyl group or may have an alkyl group. When naphthylamines have an alkyl group, those having an alkyl group in the phenyl group are preferred. In this case, 4-20 are preferable and, as for carbon number of an alkyl group, 6-18 are more preferable.

Examples of the alkylated diphenylamines include monoalkylated diphenylamines, dialkylated diphenylamines, trialkylated diphenylamines, and tetraalkylated diphenylamines, with dialkylated diphenylamines being preferred.
The alkyl group in the alkylated diphenylamines is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 3 to 14 carbon atoms, and particularly preferably an alkyl group having 4 to 12 carbon atoms.
The amine-based antioxidant has an effect of preventing a radical chain reaction at a high temperature and has a low sublimation property. Therefore, the amine-based antioxidant has an effect of improving heat resistance as compared with the case of using another antioxidant.
These antioxidants may be used alone or in combination of two or more. The content of the antioxidant is preferably 0.05 to 2 parts by mass, more preferably 0.1 to 1 part by mass, in 100 parts by mass of the composition of the present invention. If the content of the antioxidant is less than 0.05 parts by mass, the effect is small, and if the content is more than 2 parts by mass, improvement of the effect cannot be expected, and the antioxidant itself deteriorates when exposed to a high temperature for a long period of time. There exists a tendency for the heat dissipation compound composition to become hard by the influence of a thing.

  Moreover, a well-known additive can be suitably mix | blended with the thermal radiation compound composition of this invention as needed. These include, for example, sulfur antioxidants such as sulfide, disulfide, trisulfide, and thiobisphenol as secondary antioxidants, phosphorus antioxidants such as alkyl phosphite and ZnDTP, and the like as rust inhibitors. Are sulfonates, carboxylic acids, carboxylates, succinates, etc., as corrosion inhibitors, compounds such as benzotriazole and its derivatives, thiadiazole compounds, and as thickeners are polyisobutylene, polyalkylmethacrylate, olefins Examples of the thickener such as a polymer, a high-viscosity poly α-olefin, and the like include metal soap, urea compound, sodium terephthalate, polytetrafluoroethylene, organic bentonite, silica gel, petroleum wax, and polyethylene wax. The amount of these additives may be a normal amount.

  The heat-dissipating compound composition of the present invention can be easily produced by adding the components (A) and (B), or if necessary, the optional component (C) or other optional components and mixing them uniformly. it can. As such a method, there is a method of kneading while heating with a mortar, a planetary mixer or the like, and further kneading uniformly with a three roll.

EXAMPLES Hereinafter, although this invention is explained in full detail according to an Example and a comparative example, this invention is not limited at all by this.
The components shown in Tables 1 to 4 were mixed to prepare a heat dissipation compound composition, and the characteristics were evaluated by the following methods.
Evaluation method Thermal conductivity: Measured by hot wire method: QTM-500 manufactured by Kyoto Electronics
2.0 (W · m ^-1 · K ^-1 ) or higher is acceptable.
Consistency: Conforms to JIS K 2220, and the judgment is 100 or more based on the consistency when immiscible.
Oil separation resistance: A heat dissipation compound composition is sandwiched between a glass plate and a metal plate (aluminum plate) using a spacer so that the diameter is about 20 mm × thickness 50 μm. After the test (150 ° C x 12 hours → -30 ° C x 12 hours), the presence or absence of oil separation was visually determined. ×: Large oil separation △: Small oil separation ○: Slight oil separation ◎: No oil separation Heat resistance (crack resistance) Property): The heat dissipation compound composition was sandwiched between a glass plate and a metal plate (aluminum plate) using a spacer so that the diameter was about 20 mm × thickness 50 μm, and the state was maintained and placed in a thermostatic bath, and a heat cycle test (150 ° C x 12 hours → -30 ° C x 12 hours) Then, visually determine the presence or absence of voids or cracks in the compound ×: Large voids or cracks △: Small voids or cracks ○: Small voids or cracks ◎: Small voids or No crack

* 1: Acetalkoxyaluminum diisopropylate * 2: Neopentyl (diallyl) oxy tri (dioctyl) phosphate zirconate * 3: Isopropoxy titanium “-” in the column of stearate evaluation results indicates that measurement was not performed.

* 4: The filler was not previously treated with acetoalkoxyaluminum diisopropylate and dispersed in the base oil during production.
* 5: Cannot be measured because it cannot be manufactured.

(A) 2-20 mass parts of base oil, (B) The heat dissipation compound composition of Examples 1-19 of this invention containing the inorganic filler 80-98 mass parts which processed the surface with the coupling agent, High thermal conductivity, suitable consistency, and excellent oil separation resistance and heat resistance (crack resistance).
As the inorganic filler, use is made of a mixture in which the mass ratio of zinc oxide having an average particle diameter of (a) 0.8 μm or less and (b) zinc oxide having 1 to 5 μm is 2: 8 to 8: 2. Examples 3 to 11 and 17 have a particularly high thermal conductivity.
Examples 18 and 19 using zinc oxide and aluminum powder or silver powder as the inorganic filler also have particularly high thermal conductivity.
On the other hand, in Example 1 or Example 3, in Comparative Example 1 or Comparative Example 3 in which an inorganic filler not subjected to the coupling agent treatment was blended, a heat dissipation compound composition could not be produced.
Further, in Comparative Example 2 or Comparative Example 4 in which the coupling agent treatment was not performed in advance in Example 2 or Example 4 and dispersed and blended in the base oil at the time of manufacture, the thermal conductivity and the consistency were almost the same. However, it has poor oil release resistance and heat resistance (cracking resistance).

Claims (6)

(A) 2 to 20 parts by mass of a base oil, and (B) a heat dissipation compound composition containing 80 to 98 parts by mass of an inorganic filler whose surface is treated with a coupling agent,
A heat dissipation compound composition, wherein the coupling agent is at least one selected from the group consisting of neopentyl (diallyl) oxytri (dioctyl) phosphate zirconate and isopropoxy titanium stearate .   The heat-dissipating compound composition according to claim 1, wherein (A) the base oil is at least one selected from the group consisting of hydrocarbon-based synthetic oils, ether-based synthetic oils, and ester-based synthetic oils.   The heat dissipation compound composition according to claim 1 or 2, wherein the inorganic filler (B) is at least one selected from the group consisting of metal oxides, metal nitrides, boron nitrides, and metal powders.   The inorganic filler (B) is a mixture having an average particle diameter of (a) 0.8 μm or less and (b) 1 to 5 μm, but a mass ratio of 2: 8 to 8: 2. The heat-dissipating compound composition according to any one of claims 1 to 3, wherein the heat-dissipating compound composition is provided.   The heat-dissipating compound composition according to any one of claims 1 to 4, comprising 0.01 to 2.0 parts by mass of a metal deactivator as the component (C).   The metal deactivator (C) is a benzotriazole derivative, a benzimidazole derivative, a dimercaptothiazole derivative, an oxyquinoline derivative, a salicylidene derivative, a thiocarbamate compound, a piperidine compound, a salicylic acid compound, and a thiophosphate compound. It is at least 1 sort (s) chosen from the group which consists of. The heat-radiation compound composition of any one of Claims 1-5.