TWI534255B - Heat-conductive silicone grease composition - Google Patents

Description

Thermal conductivity 矽 grease composition

The present invention relates to a thermally conductive bismuth oil-and-fat composition which has a small increase in hardness and a small decrease in elongation when heated and cooked at a high temperature after curing.

Electronic components such as LSIs and IC chips are widely known for their heat release during use and performance degradation. As a means for solving this problem, various types of heat dissipation techniques are used. In a general method, a cooling member is disposed in the vicinity of the heat radiating portion, and the heat is efficiently removed by the cooling member by closely joining the two, thereby dissipating heat. At this time, if there is a gap between the heat radiating member and the cooling member, since there is air having poor thermal conductivity, heat conduction becomes inefficient, and the temperature of the heat radiating member cannot be sufficiently lowered. In order to prevent such a phenomenon, a heat-dissipating material having a good thermal conductivity and having a follow-up property to the surface of the member, a heat sink or a heat-dissipating grease is used for the purpose of preventing the presence of air (Japanese Patent No. 2938428, Patent No. 2938429) Patent No. 3952184: Patent Documents 1 to 3).

In the heat-dissipating grease, in order to make the semiconductor wafer and the heat spreader firmly adhere to the adhesive performance. If there is no heat-dissipating grease between the semiconductor wafer and the heat spreader, heat dissipation performance is insufficient, resulting in significant performance degradation, so that the semiconductor wafer and the heat spreader are strongly bonded. However, although these materials are strong, the opposite is due to the fact that the hardness of the material is increased by high-temperature etching during use. As the hardness increases, the material The elongation of the material is reduced, so it is impossible to follow the wafer strain due to the heat history of cooling <=> cooling, and the worst case may cause damage to the wafer.

Patent Document 1: Japanese Patent No. 2938428

Patent Document 2: Japanese Patent No. 2938429

Patent Document 3: Japanese Patent No. 3952184

The present invention has been made to solve the above problems, and an object of the invention is to provide a thermally conductive bismuth oil-and-fat composition which has less hardness increase and less elongation reduction when heated and cooked at a high temperature after curing. .

As a result of the inventors of the present invention, in order to achieve the above object, it has been found that a thermally conductive bismuth-and-oil composition containing the following components (A) to (F) can provide a low increase in hardness when heated and cooked at a high temperature. The invention is completed by reducing the hardened material with less elongation.

Accordingly, the present invention provides a thermally conductive bismuth oil composition comprising (A) an organic viscosity of at least 2 alkenyl groups having a dynamic viscosity of from 5,000 to 100,000 mm ² /s in one molecule. Polysiloxane: 100 parts by mass; (B) the following formula (2)

(R ² is an alkyl group having 1 to 6 carbon atoms, and b is an integer of 5 to 100)

The single-end trifunctional hydrolyzable methyl polyoxane represented by the catalyst: 10 to 90 parts by mass; (C) has 10 W/m. Thermal conductivity filler of thermal conductivity above °C: 500 to 1,500 parts by mass; (D) organic hydrogen having two or more and five or less hydrogen atoms (Si-H group) directly bonded to a halogen atom in one molecule Polyoxane: {the number of Si-H groups} / {the number of alkenyl groups of the (A) component} becomes a compounding amount of 1.7 to 2.8; (E) has a triazine ring in one molecule and at least one The auxiliary agent for the alkenyl group is 0.05 to 0.5 part by mass; (F) the catalyst selected from the group consisting of platinum and a platinum compound: the component (A) which is a platinum atom is used in an amount of 0.1 to 500 ppm.

In this case, 0.05 to 0.5 parts by mass of (G) a controlling agent selected from the group consisting of an acetylene compound, a nitrogen compound, an organophosphorus compound, an anthraquinone compound, and an organochlorine compound may be contained in an amount of 0.05 to 0.5 parts by mass based on 100 parts by mass of the component (A).

In addition, the heat-conductive bismuth oil-and-fat composition is preferably formed into a sheet having a thickness of 2 mm when the sheet obtained by curing at 150 ° C for 90 minutes has a length of 100% or more at the time of cutting as measured by the method described in JIS K6251. The elongation at the time of aging at 150 ° C for 1000 hours was 80% or more.

The thermally conductive bismuth oil composition of the present invention has a small increase in hardness when heated at a high temperature and can suppress a decrease in elongation.

The thermally conductive bismuth oil composition of the present invention comprises: (A) an alkenyl group-containing organopolyoxane, (B) a hydrolyzable methyl polyoxyalkylene, (C) a thermally conductive filler, and (D) an organic hydrogen. The polyoxyalkylene oxide, (E) a triazine ring and an alkenyl group-containing auxiliary agent, and (F) a platinum-based catalyst are contained as an essential component, and if necessary, a (G) addition reaction controlling agent is contained.

(A) component

The organopolyoxane constituting the component (A) of the present invention is one having at least two alkenyl groups directly bonded to a ruthenium atom in one molecule, and the following formula (1) R ¹ _a SiO _(4- ) can be used. _a)/2 (1)

(wherein R ¹ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms which are the same or different from each other, and a is 15 to 2.8, preferably 1.8 to 2.5, more preferably A positive number from 1.95 to 2.05.)

Shown.

Here, the above-mentioned monovalent hydrocarbon group represented by R ^{1 which} is directly bonded to an unsubstituted or substituted fluorene atom may, for example, be a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group or a tertiary group. An alkyl group such as butyl group, pentyl group, neopentyl group, hexyl group, cyclohexyl group, octyl group, decyl group or fluorenyl group; aryl group such as phenyl group, tolyl group, xylyl group or naphthyl group; benzyl group and phenylethyl group; An aralkyl group such as a phenylpropyl group; an alkenyl group such as a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a butenyl group, a hexenyl group, a cyclohexenyl group or an octenyl group; or the like Part or all of the atom is preferably a halogen atom such as fluorine, bromine or chlorine, or a cyano group or the like (for example, chloromethyl, chloropropyl, bromoethyl, trifluoropropyl or cyanoethyl). For example, 90 mol% or more of the total R ¹ is a methyl group.

Further, at least two of the total R ¹ must be an alkenyl group (preferably having 2 to 8 carbon atoms, more preferably 2 to 6 carbon atoms, and particularly preferably ethylene). Further, the content of the alkenyl group is preferably 2.0 × 10 ^-5 to 1.0 × 10 ^-4 mol / g, particularly preferably 2.0 × 10 ^-5 to 6.0 × 10 ^-5 mol / g in the organopolysiloxane. If the amount of the alkenyl group is less than 2.0 × 10 ^-5 mol/g, the progress of the composition may be deteriorated, and if it is more than 1.0 × 10 ^-4 mol/g, the hardness of the composition after hardening is ripened. The rise will increase and the elongation will decrease. The alkenyl group may be bonded to a ruthenium atom at the end of the molecular chain, a ruthenium atom which may be bonded to the molecular chain, or may be bonded to both.

The structure of the organic polyoxane, usually the main chain is basically composed of repeating units of diorganooxane, and the two ends of the molecular chain have a linear structure blocked by a triorganophosphonyl group, and The structure is a branch, a ring structure, or the like.

When the dynamic viscosity at 25 ° C of the component (A) is lower than 5000 mm ² /s, the hardness rise in the heating and ripening of the composition is increased and the elongation is decreased, and if it is more than 100,000 mm ² /s, the progress of the obtained composition is improved. The property is deteriorated, so it is in the range of 5,000 to 100,000 mm ² /s, preferably 10,000 to 100,000 mm ² /s. Further, the dynamic viscosity is a value obtained by an Ubbelohde type Ostwald viscometer.

In the case of the component (A), for example, a dimethylvinyl fluorenyl group may be used to block the dimethyl polyoxyalkylene, and the like may be used alone or in combination of two or more.

(B) component

The component (B) used in the present invention is represented by the following formula (2)

(R ² is an alkyl group having 1 to 6 carbon atoms, and b is an integer of 5 to 100.)

A single-end, trifunctional hydrolyzable methyl polyoxane, as indicated.

R ² is an alkyl group having 1 to 6 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a secondary butyl group, a tertiary butyl group, a pentyl group, and a hexyl group. Further, if b of the single-terminal trifunctional hydrolyzable methyl polyoxyalkylene represented by the above formula (2) represented by the above formula (2) is less than 5, the oil leakage due to the bismuth oil composition becomes severe, and The adhesion performance cannot be exhibited. If it is more than 100, the wettability with the filler is insufficient. Therefore, b is an integer of 5 to 100, preferably an integer of 10 to 60.

When the amount of the one-terminal trifunctional hydrolyzable methyl polyoxyalkylene is less than 10 parts by mass based on 100 parts by mass of the component (A), sufficient wettability cannot be exhibited, and if it is more than 90 parts by mass, The leakage of the composition becomes severe, so it is preferably in the range of 10 to 90 parts by mass, preferably 10 to 80 parts by mass, more preferably 50 parts by mass or less and 80 parts by mass or more, more preferably 51 to 80 parts by mass. The scope of the share.

(C) component

(C) component of the thermal conductivity of the thermal conductivity of the filler, the filler has a thermal conductivity of less than 10W / m. °C, the thermal conductivity of the bismuth oil composition itself becomes smaller, so the thermal conductivity of the filler is 10W/m. Above °C, preferably from 10 to 5000 W/m. °C. As such a thermally conductive filler, an inorganic compound powder can be used. The inorganic compound powder used in the component (C) may be, for example, selected from the group consisting of aluminum powder, zinc oxide powder, titanium oxide powder, magnesium oxide powder, alumina powder, aluminum hydroxide powder, boron nitride powder, aluminum nitride powder, One or more of diamond powder, gold powder, silver powder, copper powder, carbon powder, nickel powder, indium powder, potassium powder, metal cerium powder, cerium oxide powder, and the like. Further, the thermal conductivity in the present invention is a value measured by QTM-500 manufactured by Kyoto Electronics Industry Co., Ltd.

When the average particle diameter of the inorganic compound powder used in the component (C) is less than 0.5 μm or more than 100 μm, the filling ratio of the obtained bismuth oil composition does not increase, so it is 0.5 to 100 μm, preferably 1 to 1. A range of 50 μm. Further, in the present invention, the average particle diameter is a volume average diameter of a volume basis measurable by Microtrack MT330OEX manufactured by Nikkiso Co., Ltd. [MV]. Further, the inorganic compound powder used in the present invention may be subjected to hydrophobization treatment, hydrophobization treatment, or the like, or a known method, if necessary, an organic decane, an organic decane, an organopolyoxane or an organic fluorine compound. For example, the inorganic compound powder and the organic decane or a partial hydrolyzate thereof are TRI MIX, TWIN MIX, and a planetary mixer (all registered trademarks of a mixer manufactured by Inoue Co., Ltd.), ULTRAMIX (Ruisheng Industry ( A method in which a mixer such as a registered trademark of a mixer) and a HIVIS DISPER-MIX (registered trademark of a special machine-made mixer) is mixed. Heat to 50~100 °C if necessary. Further, a solvent such as toluene, xylene, petroleum ether, mineral spirits, isoparaffin, isopropanol or ethanol may be used for mixing. In this case, it is preferred to remove the solvent after mixing by using a vacuum apparatus or the like. Further, as the diluent solvent, an organopolyoxane of the component (A) of the liquid component of the present invention can also be used. The compositions made by this method are also within the scope of the invention.

When the amount of the thermally conductive filler (inorganic compound powder) is less than 500 parts by mass based on 100 parts by mass of the component (A), the thermal conductivity of the composition is lowered, and if it is more than 1,500 parts by mass, the viscosity of the composition is increased. On the other hand, the workability is deteriorated, so it is in the range of 500 to 1,500 parts by mass, preferably 600 to 1300 parts by mass.

(D) component

As the organic hydrogen polyoxyalkylene of the component (D), for example, the following average composition formula (3) R ³ _c H _d SiO _(4-cd)/2 (3) can be used.

(wherein R ³ is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms. Further, c is 0.7 to 2.1, preferably 0.8 to 2.05, and d is 0.001 to 1.0. Preferably, it is 0.005 to 1.0, and c+d satisfies a positive number of 0.8 to 3.0, preferably 1.0 to 2.5.

Represented.

The organic hydrogen polyoxyalkylene having a hydrogen atom (Si-H group) directly bonded to a halogen atom of the component (D) must have at least two Si in one molecule in order to reticulate the composition by crosslinking. -H base. In addition, when the amount of the Si-H group is increased, the increase in hardness during heating and aging is increased, and the elongation is decreased. Therefore, the Si-H group is in the range of 2 or more and 5 or less.

The organic group R ³ bonded to the remaining atom of the ruthenium atom may, for example, be an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group or a dodecyl group, an aryl group such as a phenyl group or the like, or a 2-phenylethyl group. a substituted alkyl group such as a 2-phenylpropyl group such as an aralkyl group, a chloromethyl group, a 3,3,3-trifluoropropyl group or the like, or a 2-glycidoxyethyl group or a 3-ring group An example of an epoxy group-containing organic group (epoxypropyl group or glycidoxy group-substituted alkyl group) such as oxypropoxypropyl group or 4-glycidoxybutyl group. The Si-H group-containing organic hydrogen polyoxyalkylene may be any of a linear chain, a branched chain, and a cyclic ring, or a mixture thereof.

The amount of the component (D), the number of Si-H groups of the component (D), that is, the number of {Si-H groups}/{(A) component, relative to the number of alkenyl groups in the component (A). If the number of alkenyl groups is less than 1.7, sufficient adhesion performance cannot be exhibited, and the adhesion to the substrate is deteriorated. The degree of increase increases and the elongation decreases, so it is in the range of 1.7 to 2.8, preferably 2.0 to 2.5.

(E) component

The adhesion aid of the component (E) is a compound having a triazine ring in one molecule and having at least one alkenyl group, and the composition can be attached to the subsequent property. The alkenyl group contained in the component (E) may be linear or branched, and examples thereof include a vinyl group, an allyl group, a 1-butenyl group, a 1-hexenyl group, and a 2-methylpropenyl group. The acryl group or the like is preferably an allyl group from the viewpoint of cost. Specific examples of the component (E) include, for example, triallyl isocyanurate and trimethylallyl isocyanurate, and 1 to 2 allyl addition to triallyl isocyanurate has 1 to 2 An alkoxy fluorenyl group substituted with an alkoxy fluorenyl group such as a trimethoxy fluorenyl group. Triallyl isocyanurate and a hydroxyl condensate (derivative) thereof, and the like.

When the amount of the component (E) is less than 0.05 parts by mass based on 100 parts by mass of the component (A), the composition cannot exhibit sufficient adhesion performance, and if it is more than 0.5 part by mass, the hydroquinone reaction cannot be sufficiently performed, and the composition cannot be sufficiently performed. Since the next performance is exhibited, it is in the range of 0.05 to 0.5 part by mass, preferably 0.05 to 0.3 part by mass.

(F) component

The catalyst of the component (F) selected from the group consisting of platinum and a platinum compound is a promoting component of an addition reaction between an alkenyl group of the component (A) and a Si-H group of the component (D). The component (F) may, for example, be a platinum monomer, a chloroplatinic acid or a platinum-olefin complex. , a platinum-alcohol complex, a platinum coordination compound, and the like. When the amount of the component (F) is less than 0.1 ppm, the amount of the component (F) is not as a catalyst, and the effect is not increased or uneconomical even if it exceeds 500 ppm. Range of ~500ppm.

(G) component

The control agent for the component (G) is a method for suppressing the progress of the hydroquinone reaction at room temperature to prolong the storage life and the pot life. As the reaction inhibitor, a known one can be used, and an acetylene compound, various nitrogen compounds, an organic phosphorus compound, a ruthenium compound, an organic chlorine compound or the like can be used. When the amount of the component (G) is less than 0.05 parts by mass, a sufficient storage life and a pot life cannot be obtained. When the amount is more than 0.5 part by mass, the curing property is lowered, so that it is preferably in the range of 0.05 to 0.5 part by mass. In order to make the dispersibility equal to the bismuth oil composition, it may be diluted with toluene or the like.

Other ingredients

Further, in addition to the above components (A) to (G), an antioxidant or the like for preventing deterioration may be added as needed.

Production method

When manufacturing the thermally conductive bismuth oil composition of the present invention, the components (A) to (F) and, if necessary, other components may be used as TRI MIX, TWIN MIX, and planetary mixers (all are Inoue Manufacturing Co., Ltd.). Registered trademark of the mixer, ULTRAMIX (Registrar of the Swiss-made mixer) A method in which a mixer such as HIVIS DISPER-MIX (registered trademark of a special machine-made mixer) is mixed.

The thermally conductive bismuth oil composition of the present invention has a high viscosity and a workability is deteriorated, so the viscosity thereof is 10 to 1000 Pa. s is better, more preferably 50~1000Pa. s. Moreover, such a viscosity can be achieved by controlling the components of the mash composition as described above. Further, in the present invention, the viscosity is a value of 25 ° C measured by a Malcom viscometer (roller A is 10 rpm, shear rate is 6 [1/s]).

The thermally conductive bismuth-and-oil composition of the present invention is preferably used between a heat-releasing member other than an electronic component such as an LSI and a cooling member to conduct heat from the heat-releasing member to the cooling member to dissipate heat, and is compatible with conventional heat conductivity. The oil and fat composition was used in the same manner.

In the heat-conductive bismuth oil-and-fat composition of the present invention, when the sheet is cured at 150 ° C for 90 minutes, the elongation at break when measured by the method described in JIS K6251 is 100% or more, and the followability to the strain of the wafer is considered. The consideration is more than 120%. The upper limit is not particularly limited, but is usually 400% or less, particularly 300% or less. Further, elongation at the time of such breakage can be achieved by using a component having a large molecular weight (component (A)) in the production of the composition.

Further, the thermally conductive bismuth-and-oil composition of the present invention is formed into a sheet having a thickness of 2 mm from the viewpoint of the strain followability of the wafer after the reliability test in the package, and is aged at 150 ° C for 1,000 hours to JIS K6251. The elongation at break obtained by the method described is 80% or more. The upper limit is not particularly limited, but is usually 300% or less, particularly 200% or less. Moreover, the elongation at the time of the fracture after the aging is achieved by using the component (D) having two or more cross-linking points of five or less at the time of preparation of the composition.

[Examples]

Hereinafter, the present invention will be specifically described by showing examples and comparative examples, but the present invention is not limited to the examples described below. Further, the test regarding the effects of the present invention was carried out as follows.

[viscosity]

The absolute viscosity of the bismuth oil composition was measured at 25 ° C using a Malcom (type PC-1T) viscometer.

[Thermal conductivity]

The compositions were transferred to a 3 cm thick mold and covered with a kitchen lamp measured by Model QTM-500 manufactured by Kyoto Electronics Industry Co., Ltd.

[Elongation at break]

Each of the compositions was heated at 150 ° C for 90 minutes to form a 2 mm thick sheet, and then a No. 2 dumbbell shape described in JIS K6251 was prepared for measurement. Further, the sample which was hardened into a sheet having a thickness of 2 mm was subjected to 150 ° C. After 1000 hours of ripening, the elongation after ripening was measured in the same manner.

[Continue strength]

Each composition was sandwiched between a 1 mm × 1 mm tantalum wafer and a 2.5 mm × 2.5 mm tantalum wafer, and heated at 150 ° C for 90 minutes under a pressure of a 1.8 kgf jig, and then Dage series manufactured by Dage Deutchland GmbH. 4000PXY was measured for strength.

The following components of the composition of the present invention are prepared.

(A) component

A-1: dimethylpolyoxane having a dynamic viscosity of 30,000 mm ² /s at 25 ° C blocked with dimethylvinyl fluorenyl at both ends

A-2: dimethylpolyoxane having a dynamic viscosity of 100000 mm ² /s at 25 ° C blocked with dimethylvinyl fluorenyl at both ends

A-3: dimethylpolyoxane having a dynamic viscosity of 10000 mm ² /s at 25 ° C blocked with dimethylvinyl fluorenyl at both ends

A-4 (Comparative Example): two terminals with dimethylvinylsiloxy silicon dynamic viscosity of 25 ℃ alkyl blockade of 500000mm ² / s of the dimethylpolysiloxane silicon oxyalkyl

A-5 (Comparative Example): dimethylpolyoxane having a dynamic viscosity at 25 ° C of 3000 mm ² /s blocked with dimethylvinyl fluorenyl at both ends

(B) component B-1:

B-2:

(C) component

The following aluminum powder and zinc oxide powder were mixed at room temperature for 15 minutes using a 5 liter planetary mixer (manufactured by Inoue Seisakusho Co., Ltd.) to obtain C-1.

. Aluminum powder with an average particle diameter of 2.0 μm (thermal conductivity: 237 W/m.°C)

. Aluminum powder with an average particle diameter of 10.0 μm (thermal conductivity: 237 W/m.°C)

. Zinc oxide powder with an average particle diameter of 1.0 μm (thermal conductivity: 25 W/m.°C)

(D) component

Organic hydrogen polyoxane represented by the following formula

D-1:

D-2:

D-3:

D-4 (comparative example):

D-5 (comparative example):

(E) component E-1:

(F) component

F-1: A-1 solution of platinum-divinyltetramethyldioxane complex containing 1% by mass of platinum atom

(G) component

50% by mass toluene solution of G-1:1-vinyl-1-cyclohexanol

[Examples 1 to 11 and Comparative Examples 1 to 7]

The components of Examples 1 to 11 and Comparative Examples 1 to 7 were obtained by mixing the components (A) to (G) as follows.

In other words, the component (A) was placed in a 5 liter planetary mixer (manufactured by Inoue Seisakusho Co., Ltd.), and the components (B) and (C) were added in the amounts shown in Tables 2 and 3, and mixed at 150 ° C for 1 hour. . The mixture was cooled to room temperature, and then the components (D), (E), (F), and (G) were added in an appropriate amount as shown in Tables 2 and 3.

The present invention relates to a heat conductive strontium oil composition for heat dissipation which combines the properties of the material and the flexibility of the material after high temperature aging. When the prior art other than the present invention is used, there is a problem in that reliability is caused when the high-temperature ripening is accompanied by the subsequent performance, and the performance is not attached when the reliability is maintained. That is, it is difficult to achieve both the reliability of the subsequent performance and the high temperature ripening.

Claims (4)

A thermally conductive bismuth oil composition characterized by comprising: (A) an organopolyoxane having a dynamic viscosity at 25 ° C of at least 2 alkenyl groups of from 1 to 50000 mm ² /s in one molecule: 100 parts by mass; (B) the following general formula (2) (R ² is an alkyl group having 1 to 6 carbon atoms, and b is an integer of 5 to 100), and a single-terminal trifunctional hydrolyzable methyl polyoxyalkylene represented by 10 to 90 parts by mass; (C) having 10 W/ m. Thermal conductivity filler of thermal conductivity above °C: 500 to 1500 parts by mass; (D) organic hydrogen having two or more and five or less hydrogen atoms (Si-H groups) directly bonded to a halogen atom in one molecule Polyoxane: {the number of Si-H groups} / {the number of alkenyl groups of the (A) component} becomes a compounding amount of 1.7 to 2.8; (E) has a triazine ring in one molecule and at least one The auxiliary agent for the alkenyl group is 0.05 to 0.5 part by mass; (F) the catalyst selected from the group consisting of platinum and a platinum compound: the component (A) which is a platinum atom is used in an amount of 0.1 to 500 ppm. The thermally conductive bismuth oil composition according to Item 1 of the patent application, which contains 0.05 to 0.5 parts by mass based on 100 parts by mass of the component (A). (G) is selected from the group consisting of acetylene compounds, nitrogen compounds, organophosphorus compounds, antimony compounds, and control agents for organochlorine compounds. A heat-conductive bismuth oil-and-fat composition characterized in that the sheet obtained by curing the heat-conductive bismuth oil-and-fat composition at 150 ° C for 90 minutes has a elongation of 100% or more when measured by the method described in JIS K6251, and is formed. When the sheet having a thickness of 2 mm was cut at 150 ° C for 1,000 hours, the elongation was 80% or more. The heat conductive bismuth oil composition according to the first aspect of the patent application, wherein the compounding amount of the component (D) is {the number of the {Si-H groups}/the number of the alkenyl groups of the (A) component is 2.0~ 2.5.