TWI468483B - Thermal follower - Google Patents

Description

Thermally conductive adhesive

The present invention relates to a thermally conductive adhesive, and more particularly to a thermally conductive adhesive suitable for use in following an electronic component and a heat dissipating member or a heat generating member.

In recent years, with the increase in the performance, size, and density of electronic processing devices (CPUs) and chipsets of electronic components such as computers, the heat generation of electronic components and components to which the electronic components are mounted has increased. Therefore, the cooling of the electronic component is a very important technique in maintaining the performance of the electronic component and the component on which the electronic component is mounted. The heat dissipation efficiency of an electronic component is generally improved by bringing a substance having good thermal conductivity into contact with an electronic component. Therefore, the demand for heat dissipating materials (TIMs) having excellent thermal conductivity is increasing.

The heat dissipating material, for example, is placed between the electronic component and a cooling system (e.g., a heat sink) to serve as a task of effectively communicating the heat emitted by the electronic component to the cooling system. The heat dissipating material is classified into a sheet-like molded product and a paste-like composition according to its shape or usage. The sheet-like molded article is, for example, a heat dissipating sheet classified into an elastomer (having an elastic polymer substance) type and a heat-change type phase change sheet (a sheet using a heat dissipating material which changes phase with temperature). The paste composition is classified, for example, into a non-hardening type heat-dissipating grease, and a heat-dissipating gel or a heat-dissipating adhesive which is a paste at the time of coating but gelled or elastomerized, for example, by heat treatment.

Such heat dissipating materials are generally composite materials having a high density filled with a thermally conductive material in an organic polymeric material. The thermal conductivity of organic polymeric materials is generally small and does not vary greatly depending on the type of organic polymeric material. Therefore, the thermal conductivity of the heat dissipating material is greatly dependent on the volume filling rate of the thermally conductive material in the organic polymer material. Thus, how to fill a large amount of thermally conductive material in an organic polymer material is important.

Heat-dissipating adhesives are required to have high thermal conductivity while having an adhesive force under a wide variety of environments or stresses. The higher the density of the organic polymer material is filled with the heat conductive material, the more the heat dissipation property of the heat dissipation material is improved. However, the higher the density of the thermally conductive material in the organic polymer material, the heat dissipating material itself becomes brittle, and the flexibility or adhesion to the attached body deteriorates.

As the organic polymer material which is a heat-dissipating adhesive, an epoxy resin, a polyoxymethylene polymer, a polyimide or the like is known. However, although the epoxy resin has good adhesion, it has disadvantages in heat resistance and durability. Therefore, from the viewpoint of coatability to a heat conductive material, flexibility after softening, thermal stability, and the like, a polyoxymethylene polymer is preferably used (for example, refer to Patent Documents 1 and 2 below). However, a heat dissipating material using a polyoxyl polymer cannot satisfy both the adhesion and the heat dissipation.

Further, when a polyimide having improved heat resistance is used, since the polyimide resin is a solid, it is impossible to fill a heat conductive material, and it has to be dissolved in a solvent or the like to be filled. In order to avoid this, it is necessary to fill the heat-transfer substance in the polyamic acid solution of the precursor, and since it is usually required to be heated at 300 ° C or higher, the heat load to the surroundings cannot be avoided.

Further, in order to protect the surface of a wiring portion such as a semiconductor element or a printed board, it is known to use a polyimide polyimide resin, and the adhesion and durability to a substrate under high-humidity conditions are higher than that of a polyoxymethylene rubber. Highness is high (for example, refer to Patent Document 3 below). There is also disclosed an adhesive using a composition containing the polyamidene polyoxyalkylene resin as a semiconductor (for example, see Patent Document 4). However, the use of thermal conductive adhesives of such polyamidene polyoxyl resins, in particular, the review of electrically insulating thermal conductive adhesives is not required.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] JP-A-2006-342200 publication

[Patent Document 2] Japanese Patent Publication No. 61-3670

[Patent Document 3] JP-A-2002-012667

[Patent Document 4] JP-A-2006-005159

An object of the present invention is to provide a thermally conductive adhesive (also referred to as a heat-dissipating paste) having excellent thermal conductivity and excellent electrical conductivity for an adherend such as a heat generating member and a heat dissipating member.

The present invention is a thermal conductive adhesive described below.

A thermally conductive adhesive comprising:

(A) Polyamidiamine polyoxyl resin having a weight average molecular weight of 5,000 to 150,000 in a repeating unit represented by the following formula (1): 100 parts by mass

(B) electrically insulating thermally conductive filler 100 to 10,000 parts by mass, and

(C) Organic solvent.

【化1】

(In the formula (1), W is a tetravalent organic group, X is a divalent group having a phenolic hydroxyl group, Y is a divalent polyfluorene residue represented by the following formula 2, and Z is a group other than X and Y. The valence organic group, p, q and r are each 0.15≦p≦0.6, 0.05≦q≦0.8, 0≦r≦0.75, and p+q+r=1);

[Chemical 2]

(In the formula (2), R ¹ and R ^{2 are} each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 8 carbon atoms, and a is an integer of 1 to 20).

In one embodiment of the present invention, the thermally conductive adhesive further contains (D) a thermosetting resin in an amount of 0.1 to 20 parts by mass.

In one embodiment of the present invention, the thermosetting resin is reactive with a phenolic hydroxyl group in the formula (1).

In one embodiment of the present invention, the thermal conductivity adhesive has a bonding strength to the copper plate of 3 MPa or more, preferably 5 to 10 MPa.

When the thermally conductive adhesive of the present invention is placed on a copper plate and heated, the thermally conductive adhesive flows to wet and spread on the surface of the copper plate. Therefore, the steel sheet is in close contact with the steel sheet by heat treatment, resulting in a good adhesion.

When the thermally conductive adhesive of the present invention is applied to the attached body and heated for curing, the adhesive flows to wet the surface of the attached body and diffuse, and the thermally conductive filler exposes the cured adhesive due to solvent evaporation. s surface. Therefore, good thermal conductivity is obtained.

The present invention also provides an electronic component which is obtained by adhering a substance obtained by hardening the above-mentioned thermally conductive adhesive to a heat dissipating member or a heat generating member.

The thermally conductive adhesive of the present invention has excellent thermal conductivity and excellent adhesion to an adherend by a polyimide-containing polyfluorene resin having a specific structure, a thermally conductive filler, and an organic solvent.

Form of implementing the invention

The thermally conductive adhesive of the present invention will be described in more detail below.

(A) Polyimine polyoxyl resin

The polyamidene polyoxyl resin has a repeating unit represented by the following formula (1).

[化3]

The W in the formula (1) is a tetravalent organic group. W can be selected, for example, from pyromellitic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride. , 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-diphenylphosphonium tetracarboxylic dianhydride, 3,3',4,4' - benzophenone tetracarboxylic dianhydride, ethylene glycol trimellitic acid dianhydride, 4,4'-hexafluoropropylene phthalic acid dianhydride, 2,2-bis[4-(3, Residue of 4-phenoxydicarboxylic acid)phenyl]propionic acid dianhydride.

X in the formula (1) is a divalent organic group having a phenolic hydroxyl group. X is, for example, derived from a diamine having a phenolic hydroxyl group. X is, for example, a group represented by the following formulas (3) to (8).

【化4】

【化5】

【化6】

【化7】

【化8】

【化9】

Y in the formula (1) is a divalent polyfluorene residue represented by the following formula (2).

【化10】

R ¹ and R ² in the formula (2) are each independently a substituted or unsubstituted one-valent hydrocarbon group having 1 to 8, preferably 1 to 4 carbon atoms. R ¹ and R ^{2 are,} for example, a methyl group or an ethyl group.

In the formula (2), a is an integer of from 1 to 20, preferably from 3 to 20. When a is larger than 20, the adhesion to the adherend becomes weak.

The Z system in the formula (1) is a divalent organic group other than X and Y. Z is, for example, derived from a diamine used in a conventional polyimine resin. The diamine is, for example, a combination of one or more selected from the group consisting of aliphatic diamines and aromatic diamines. The aliphatic diamine is, for example, tetramethylenediamine, 1,4-diaminocyclohexane or 4,4'-diaminodicyclohexylmethane. The aromatic diamine is, for example, phenylenediamine, 4,4'-diaminodiphenyl ether or 2,2-bis(4-aminophenyl)propane. Z is preferably a group derived from an aromatic diamine represented by the following formula (9).

【化11】

B in the formula (9) is a group represented by any one of the following formulas (10), (11), and (12).

【化12】

【化13】

【化14】

In order to exhibit the effect from the repeating unit, p, q and r in the formula (1) are 0.15 ≦p ≦ 0.6, 0.05 ≦ q ≦ 0.8, 0 ≦ r ≦ 0.75, preferably 0.2 ≦ p ≦ 0.5. , 0.05≦q≦0.75, 0≦r≦0.6. If it is this range, good adhesion to the adherend is obtained.

The total of p + q + r in the formula (1) is 1.

The polyiminoimine polyoxyl resin has a weight average molecular weight of 5,000 to 150,000, preferably 20,000 to 150,000. The reason for this is that if the molecular weight is less than the above lower limit, the toughness as a resin cannot be exhibited. On the other hand, when the molecular weight is more than the above upper limit, mixing with a thermally conductive filler to be described later becomes difficult.

The above polyimine polyoxyl resin can be produced, for example, by a well-known method described below.

First, a tetracarboxylic dianhydride for deriving W, a diamine for deriving X and Z, and a diamine polyoxyalkylene for deriving Y are introduced into a solvent, and then at a low temperature, for example, at 0. The reaction was carried out at ~50 °C. The above solvent is, for example, one or a combination of two or more selected from N-methyl-2-pyrrolidone (NMP), cyclohexanone, γ-butyrolactone, and N,N-dimethylacetamide (DMAc). Further, in order to easily remove the water formed by the amination of the oxime by azeotropy, an aromatic hydrocarbon such as toluene or xylene may be used in combination. By the above reaction, the polyamido acid of the precursor of the polyimine resin is produced. Next, the solution of the polyamic acid is heated to a temperature of preferably 80 to 200 ° C and particularly preferably 140 to 180 ° C. By this temperature rise, the decylamine of polyproline is subjected to a dehydration ring-closure reaction to obtain a solution of a polyamidene polyoxynene resin. When the solution is introduced into a solvent, for example, into water, methanol, ethanol or acetonitrile, a precipitate is formed. The resulting precipitate was dried to obtain a polyamidene polyoxymethylene resin.

The total molar ratio of the diamine and the diamine polysiloxane is preferably from 0.95 to 1.05, particularly preferably from 0.98 to 1.02, based on the tetracarboxylic dianhydride.

In order to adjust the molecular weight of the polyamidene polyoxyl resin, a difunctional carboxylic acid such as phthalic anhydride, and a monofunctional amine such as aniline may also be added to the above solution. The amount of these compounds added is, for example, 2 mol% or less based on the tetracarboxylic acid and the diamine.

The hydrazine can also be imidized by adding a dehydrating agent and a ruthenium-imiding catalyst during the hydrazine imidization, and heating to 50 ° C right and left as needed. The dehydrating agent is, for example, an acid anhydride such as acetic anhydride, propionic anhydride and trifluoroacetic anhydride. The amount of the dehydrating agent used is, for example, 1 to 10 moles per 1 mole of the diamine. The quinone imidization catalyst is, for example, a tertiary amine such as pyridine, trimethylpyridine, lutidine or triethylamine. The amount of the ruthenium-catalyzed catalyst used is, for example, 0.5 to 10 moles relative to the dehydrating agent used in 1 mole.

When a plurality of diamines and/or tetracarboxylic dianhydrides are used, for example, a method in which the raw materials are all mixed in advance and copolymerized and condensed is used, and two or more kinds of diamines or tetracarboxylic dianhydrides are separately reacted. Add in order. However, the reaction method is not particularly limited by this illustration.

(B) Electrically insulating thermally conductive filler

The electrically insulating thermally conductive filler is, for example, a metal oxide and a ceramic powder. The metal powder is, for example, zinc oxide powder or alumina powder. The ceramic powder is, for example, tantalum carbide powder, tantalum nitride powder, boron nitride powder, or aluminum nitride powder. The thermally conductive filler is suitably selected depending on the stability or cost.

The shape of the thermally conductive filler is not particularly limited, and is, for example, a granular shape, a dendritic shape, a flake shape, and an indefinite shape. One or a mixture of two or more kinds of thermally conductive filler powders having such a shape may also be used. The particle size distribution of the thermally conductive filler is not particularly limited, and is, for example, 90% by weight or more, preferably 95% by weight or more, in the range of 0.05 to 100 μm. The average particle diameter of the thermally conductive filler is not particularly limited, and is, for example, in the range of 1 to 50 μm. As the thermally conductive filler, for example, a single distribution (monomodality) can be used. However, in order to uniformly disperse the thermally conductive filler in the adhesive at a high density, a plurality of thermally conductive fillers having different shapes and particle diameters are combined to have a multimodal distribution, which is more effective than using a single distribution of the thermally conductive filler. .

The ratio of the amount of the thermally conductive filler in the thermally conductive adhesive of the present invention is 100 to 10,000 parts by mass, preferably 200 to 6,000 parts by mass per 100 parts by mass of the polyamidene polyoxymethylene resin. When the ratio of the amount of the thermally conductive filler blended is less than the above lower limit, sufficient thermal conductivity cannot be obtained when the thermally conductive adhesive of the present invention is used. In addition, when the ratio of the amount of the thermally conductive filler blended exceeds the above upper limit, when the thermally conductive adhesive of the present invention is used, sufficient adhesive strength is not obtained between the bonded and the adherend.

(C) organic solvent

The organic solvent is compatible with the component (A), and it is preferred that the surface state of the component (B) is not affected. The organic solvent is, for example, a combination of one or more selected from the group consisting of ethers, ketones, esters, cellosolves, guanamines, and aromatic hydrocarbons. The ethers include, for example, tetrahydrofuran and anisole. The ketones include, for example, cyclohexanone, 2-butanone, methyl isobutyl ketone, 2-heptanone, 2-octanone, and acetophenone. The esters include, for example, butyl acetate, methyl benzoate, and γ-butyrolactone. The cellosolve includes, for example, butyl carbitol acetate, butyl cellosolve acetate, and propylene glycol monomethyl ether acetate. The guanamines include, for example, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. The aromatic hydrocarbons include, for example, toluene and xylene. The organic solvent is preferably selected from the group consisting of ketones, esters, cellosolves, and guanamines. The organic solvent is particularly preferably butyl carbitol acetate, γ-butyrolactone, propylene glycol monomethyl ether acetate, and N-methyl-2-pyrrolidone. These solvents may be used alone or in combination of two or more.

The amount of the organic solvent is, for example, considering the solubility of the polyimide polyimide resin, the workability at the time of coating the thermal conductive adhesive or the thickness of the film, and usually the amount of the polyimide resin, relative to The total amount of the resin and the solvent is from 10 to 60% by mass, preferably from 20 to 50% by mass. When the composition is stored, it may be previously prepared to a relatively high concentration, and diluted to a desired concentration at the time of use.

The thermally conductive adhesive of the present invention may further contain (D) a thermosetting resin. The thermosetting resin reacts with a phenolic hydroxyl group to form a crosslinked structure. Since the thermally conductive adhesive contains a thermosetting resin, for example, it exhibits solvent resistance. The thermosetting resin is preferably an epoxy resin. The epoxy resin is, for example, a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a triphenylmethane type epoxy resin, a cyclic aliphatic epoxy resin, a glycidyl ester type resin, and a glycidylamine type resin. 1 or more. The bisphenol A type epoxy resin is, for example, a phenol novolac type epoxy resin, a cresol novolak type epoxy resin, or diglycidyl bisphenol A. The bisphenol F type epoxy resin is, for example, diglycidyl bisphenol F. The triphenylmethane type epoxy resin is, for example, trishydroxyphenylpropane triglycidyl ether. The cyclic aliphatic epoxy resin is, for example, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate. The glycidyl ester-based resin is, for example, diglycidyl phthalate, diglycidyl hexahydrocarbonate or dimethyl glycidyl phthalate. The glycidylamine-based resin is, for example, tetraglycidyldiaminediphenylmethane, triglycidyl-p-aminophenol, diglycidylaniline, diglycidyltoluidine, tetraglycidyl bisaminomethyl Cyclohexane. Further, if necessary, a monofunctional epoxy compound containing one epoxy group in one molecule may be further added to the thermally conductive adhesive. Further, for the purpose of improving the adhesion to the substrate, a carbon functional decane may be added.

The amount of the epoxy resin is preferably from 0.1 to 20 parts by mass, more preferably from 0.1 to 15 parts by mass, per 100 parts by mass of the polyamidene polyoxymethylene resin. When the blending amount exceeds the above upper limit, the thermal strength of the thermally conductive adhesive of the present invention tends to decrease.

The thermally conductive adhesive of the present invention may contain various curing accelerators for the purpose of promoting the reaction of the above epoxy resin. The hardening accelerator is, for example, one or more of an organic phosphine compound, an amine compound, and an imidazole compound. The organic phosphine compound is, for example, triphenylphosphine or tricyclohexylphosphine. The amine compound is, for example, trimethylhexamethylenediamine, diaminodiphenylmethane, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylamino) Base) phenol, triethanolamine. The imidazole compound is, for example, 2-methylimidazole, 2-ethylimidazole, 2-undecylimidazole, 2-ethyl-4-methylimidazole, and 2-phenyl-4,5-dihydroxymethylimidazole.

The amount of the hardening accelerator is preferably 0 to 5 parts by mass based on 100 parts by mass of the total of the polyimide and the epoxy resin. If the compounding amount exceeds the above upper limit, the pot life tends to be deteriorated.

The polyimide polyimide polyether resin exhibits excellent heat resistance, mechanical strength, solvent resistance, and adhesion to various substrates by thermal curing.

The curing conditions of the adhesive of the present invention are not particularly limited, and are 80 ° C or more and 300 ° C or less, preferably 100 ° C or more and 200 ° C or less. When hardened below the lower limit, the thermosetting is excessively time consuming and not practical. When the composition and composition are selected so as to be hardened at a low temperature which does not reach the above lower limit, the storage stability of the adhesive may be problematic. Further, the thermally conductive adhesive of the present invention is different from the conventional polyamic acid solution, and since it is not required to be heated at a high temperature of 300 ° C or higher and heated for a long period of time, thermal degradation of the substrate can be suppressed.

The thermal conductive adhesive of the present invention may be added with an anti-aging agent, an ultraviolet absorber, an adhesion improver, or the like, in addition to the above-mentioned components, for example, insofar as the effects of the present invention and the effect of the thermally conductive adhesive are not impaired. Fuel, surfactant, preservation stability improver, anti-ozone degradant, light stabilizer, tackifier, plasticizer, decane coupling agent, antioxidant, thermal stabilizer, radiation shielding agent, nucleating agent, lubricant One or two or more selected from the pigment and the physical property adjuster.

The thermally conductive adhesive of the present invention preferably has a viscosity of from 0.5 to 2,000 Pa s at 25 ° C, more preferably from 1.0 to 1000 Pa ‧ s.

The thermal conductivity (W/mK) of the thermally conductive adhesive of the present invention is preferably 0.5 or more, more preferably 1.0 or more, and particularly preferably 3 or more.

The thermal conductive adhesive of the present invention preferably has a bonding strength (MPa) of 3 or more, more preferably 5 or more, and particularly preferably 6 or more. The bonding strength (MPa) after standing for 240 hours in a high-temperature and high-humidity environment of 80 ° C and 95 RH is preferably the same as described above.

The thermal conductive adhesive of the present invention can be applied, for example, to an adhesive for a large-calorie LED wafer for high brightness, or an adhesive for a semiconductor element having a large amount of heat per unit area with miniaturization and weight reduction.

The invention is illustrated in more detail below by the examples, but the invention is not limited by the examples.

1. Synthesis of polyamidene polyoxyl resin

Three kinds of polyimine polyfluorene resins were produced as shown in the following Synthesis Examples 1 to 3.

Synthesis Example 1

In a flask equipped with a stirrer, a thermometer and a nitrogen gas displacement device, 88.8 g (0.2 mol) of 4,4'-hexafluoropropylene phthalic acid dianhydride and 500 g of n-methyl-2-pyrrolidone were charged. Next, 33.6 g (0.04 mol) of the diamine oxirane represented by the formula (13) and 17.3 g (0.08 mol) of 4,4'- (100 g) were prepared to be dissolved in 100 g of n-methyl-2-pyrrolidone. A solution of 3,3'-dihydroxy)diaminobiphenyl and 32.8 g (0.08 mol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane. The solution was dropped into the above flask. During the dropping, the temperature of the reaction system was adjusted so as not to exceed 50 °C. After the completion of the dropwise addition, the mixture was further stirred at room temperature for 10 hours. Next, after the flask was equipped with a reflux condenser equipped with a moisture receiver, 50 g of xylene was added, and the temperature was raised to 150 ° C, and the temperature was maintained for 6 hours. As a result, a yellowish brown solution was obtained.

【化15】

The yellow-brown solution obtained above was cooled to room temperature (25 ° C), and poured into methanol to reprecipitate. 140 g of the obtained precipitate was dried, and its linear absorption spectrum was measured. As a result, the absorption (1,640 cm ^-1 ) based on the unreacted poly ^- proline did not occur, and it was confirmed that there were ruthenium ^- based absorption at 1,780 cm ^-1 and 1,720 cm ^-1 . Next, the weight average molecular weight (in terms of polystyrene) was measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent, and it was 30,000. The product is referred to as a polyamidene polyoxyl resin (I).

Synthesis Example 2

In a flask equipped with a stirrer, a thermometer and a nitrogen gas displacement device, 88.8 g (0.2 mol) of 4,4'-hexafluoropropylene phthalic acid dianhydride and 500 g of n-methyl-2-pyrrolidone were charged. Next, 67.2 g (0.08 mol) of the diamine oxirane represented by the above formula 13 and 17.3 g (0.08 mol) of 4,4'-(3) were dissolved in 100 g of n-methyl-2-pyrrolidone. , a solution of 3'-dihydroxy)diaminobiphenyl and 16.4 g (0.04 mol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane. The solution was dropped into the above flask. During the dropping, the temperature of the reaction system was adjusted so as not to exceed 50 °C. After the completion of the dropwise addition, the mixture was further stirred at room temperature for 10 hours. Next, after the flask was equipped with a reflux condenser equipped with a moisture receiver, 50 g of xylene was added, and the temperature was raised to 150 ° C, and the temperature was maintained for 6 hours. As a result, a yellowish brown solution was obtained.

The yellow-brown solution obtained above was cooled to room temperature (25 ° C), and poured into methanol to reprecipitate. 160 g of the obtained precipitate was dried, and its linear absorption spectrum was measured. As a result, the absorption (1,640 cm ^-1 ) based on the unreacted poly ^- proline did not occur, and it was confirmed that there were ruthenium ^- based absorption at 1,780 cm ^-1 and 1,720 cm ^-1 . Next, the weight average molecular weight (in terms of polystyrene) was measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent, and it was 34,000. The product is referred to as a polyamidene polyoxyl resin (II).

Synthesis Example 3

In a flask equipped with a stirrer, a thermometer and a nitrogen gas displacement device, 88.8 g (0.2 mol) of 4,4'-hexafluoropropylene phthalic acid dianhydride and 600 g of n-methyl-2-pyrrolidone were charged. Next, it is prepared to dissolve 244.8 g (0.08 mol) of the diamine oxirane represented by the formula (14) and 17.3 g (0.08 mol) of 4,4'-(100 g) in n-methyl-2-pyrrolidone. A solution of 3,3'-dihydroxy)diaminobiphenyl and 16.4 g (0.04 mol) of 2,2-bis[4-(4-aminophenoxy)phenyl]propane. The solution was dropped into the above flask. During the dropping, the temperature of the reaction system was adjusted so as not to exceed 50 °C. After the completion of the dropwise addition, the mixture was further stirred at room temperature for 10 hours. Next, after the flask was equipped with a reflux condenser equipped with a moisture receiver, 50 g of xylene was added, and the temperature was raised to 150 ° C, and the temperature was maintained for 6 hours. As a result, a yellowish brown solution was obtained.

【化16】

The yellow-brown solution obtained above was cooled to room temperature (25 ° C), and poured into methanol to reprecipitate. 300 g of the obtained sediment was dried, and its linear absorption spectrum was measured. As a result, the absorption (1,640 cm ^-1 ) based on the unreacted poly ^- proline did not occur, and it was confirmed that there were ruthenium ^- based absorption at 1,780 cm ^-1 and 1,720 cm ^-1 . Next, the weight average molecular weight (in terms of polystyrene) was measured by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent, and it was 36,000. The product is referred to as a polyamidene polyoxyalkylene resin (III).

2. Preparation of adhesive

The following raw materials were used.

(A) Polyimine polyoxyl resin: The polyamidene polyoxyl resin (I), (II) or (III) obtained in the above Synthesis Examples 1 to 3 was used.

(B) Electrically insulating thermally conductive filler:

(B1) Thermally conductive filler A: alumina having an average particle diameter of 10 μm (specific gravity: 3.98)

(B2) Thermally conductive filler B: alumina having an average particle diameter of 1 μm (specific gravity: 3.98)

(C) Organic solvent: butyl carbitol acetate (BCA)

(D) Thermosetting resin: diglycidyltoluidine (DGT)

[Examples 1 to 4 and Comparative Examples 1 to 2]

(A) respective polythenimine polyoxyalkylene resins (I) to (III), (B) electrically insulating thermally conductive fillers (B1 and B2), (C) organic solvents, and (D) thermosetting properties The resin was placed in a spinning revolving mixer at a mass ratio shown in Table 1, stirred to be uniform, and then defoamed to obtain an adhesive.

3. Evaluation test

With respect to the adhesives obtained in Examples 1 to 4 and Comparative Examples 1 and 2, evaluation tests of viscosity, thermal conductivity, and adhesion strength were carried out in accordance with the following methods. Further, the heat-curable one-liquid type polyoxyethylene rubber C (commercial product) and D (commercial product) were subjected to evaluation tests (Comparative Example 3 and Comparative Example 4, respectively) by the same procedure as above. The results are shown in Table 2.

(1) Viscosity

The viscosity of each adhesive was measured at 25 ° C using a BH type rotational viscometer.

(2) Thermal conductivity

Each of the adhesives was poured into a groove of a Teflon (trademark) (made of DuPont) plate, dried at 80 ° C for 30 minutes, and the adhesive was further heated at 150 ° C for 1 hour to prepare a test piece of 10 mm Φ × 1 mm. The thermal diffusivity and the specific heat capacity of the test piece were measured using a laser flash thermal constant measuring apparatus (LFA447 (manufactured by NETZSCH)) to determine the thermal conductivity.

(3) subsequent strength

Each of the adhesives was applied onto a copper plate (100 mm × 25 mm × 1 mm) at a coating area of 20 mm × 20 mm, and bonded to another copper plate of the same size. The bonded copper plate was dried at 80 ° C for 30 minutes, further dried at 150 ° C for 2 minutes under a pressure of 4 MPa, and then heated at 150 ° C for 1 hour to obtain a test piece. The shear strength of the test piece was measured at a rate of 5 mm/min using an automatic plotter (STROGRAPH V10-D (manufactured by Toyo Seiki Co., Ltd.)).

In addition, the test piece obtained in the same manner as described above was exposed to 80 ° C / 95% RH for 240 hours (high temperature and high humidity test), and the shear strength was measured in the same manner as above (after the high temperature and high humidity test).

According to the above results, the adhesives 1 to 3 have a moderate viscosity, the thermal conductivity is good at 1.1 to 3.0 W/mK, and the strength is preferably 8 to 15 MPa, and the decrease in the adhesion strength before and after the high temperature and high humidity test is hardly observed. .

Claims (6)

A thermally conductive adhesive comprising: (A) a polyilylimine polyfluorene resin having a weight average molecular weight of 5,000 to 150,000 having a repeating unit represented by the following formula (1): 100 parts by mass (B) electrically insulating heat conduction 100~10,000 parts by mass of filler, and (C) organic solvent (Here, in the formula (1), the W system may be selected from pyromellitic dianhydride, 2,3,3',4-biphenyltetracarboxylic dianhydride, 3,3', 4,4' -biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-diphenylphosphonium tetracarboxylic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, ethylene glycol trimellitic acid dianhydride, 4,4'-hexafluoropropylene phthalic acid dianhydride, 2, a tetravalent organic group represented by any one of residues of 2-bis[4-(3,4-phenoxydicarboxylic acid)phenyl]propionic acid dianhydride, and X-based divalent having a phenolic hydroxyl group a group, Y is a divalent polyanthracene residue represented by the following formula (2), (In the formula (2), R ¹ and R ^{2 are} each independently a substituted or unsubstituted one-valent hydrocarbon group having 1 to 8 carbon atoms, and a is an integer of 1 to 20), and in the formula (1), the Z-form X and The divalent organic group other than Y is a group derived from an aromatic diamine represented by the following formula (9). B in the formula (9) is selected from the group represented by any one of the following formulas (10), (11), and (12). Further, p, q and r in the formula (1) are each 0.15≦p≦0.6, 0.05≦q≦0.8, 0≦r≦0.75, and p+q+r=1). The thermally conductive adhesive according to claim 1, further comprising (D) a thermosetting resin. The thermally conductive adhesive according to claim 1, further comprising 0.1 to 20 parts by mass of the (D) thermosetting resin. The thermally conductive adhesive according to claim 2, wherein the thermosetting resin is reactive with a phenolic hydroxyl group in the formula (1). The thermal conductive adhesive according to item 1 of the patent application, wherein the bonding strength to the copper sheet is 3 MPa or more. An electronic component obtained by adhering a material obtained by curing a thermally conductive adhesive agent according to any one of claims 1 to 5 to an electronic component formed on a heat dissipating member or a heat generating member.