TW201536906A - Heat conductive composite sheet - Google Patents

Abstract

To provide a conductive composite sheet, that is highly flexible, whose mounting process is easy, and that follows a front surface shape of an exothermic body. The heat conductive composite sheet is formed by laminating a heat radiation layer having a thickness of equal to or more than 10 [mu]m and equal to or less than 100 [mu]m on one surface of a heat conduction layer whose thermal conductivity in a surface direction is equal to or more than 200 W/mK and laminating on the other surface a thermal conductive silicone resin layer whose thickness is equal to or more than 0.2 mm and Asker C hardness is equal to or less than 40.

Description

Thermally conductive composite sheet

The present invention relates to a thermally conductive composite sheet which is suitable for being mounted on an electronic device or the like in which a cooling member such as a heat sink cannot be used.

With the miniaturization, thinning, and high performance of electronic devices such as televisions, computers, communication devices, and industrial devices, the amount of heat generated by such chips mounted on such CPUs and drive ICs is increasing. An increase in the temperature of the wafer causes malfunction and destruction of the wafer. Therefore, in order to suppress the temperature rise of the wafer during operation, many heat dissipation methods and heat dissipation members for the heat dissipation methods have been proposed. In an electronic device or the like, in order to suppress an increase in temperature of a wafer during operation, a heat sink using a metal plate having a high thermal conductivity such as aluminum or copper is used. The heat sink is heat generated by conducting the wafer, and the heat is released from the surface by a temperature difference from the outside air.

In order to transfer the heat generated by the wafer to the heat sink efficiently, it is necessary to make the heat sink adhere to the wafer, but it will have a softness due to the difference in the height of each wafer or the tolerance caused by the assembly process. A flexible sheet or a thermal grease is disposed between the wafer and the heat sink, and heat conduction from the wafer to the heat sink is achieved through the sheet or the thermal paste.

However, as described above, the situation in which the heat sink cannot be mounted due to the miniaturization, thinning, and high performance of the machine is increasing. For example, a smart phone or a digital camera that assumes the assumption of carrying; a LED illumination that is placed on the ceiling or suspended from the ceiling as a premise, the heat sink cannot be used due to size or weight problems, or the heat sink is required to be removed. Based on such a situation, several heat-dissipating countermeasure parts using heat radiation have been reported.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2006-298703

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2004-43612

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2013-144747

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2004-200199

A heat dissipating method has been proposed which is obtained by firing a cordierite powder having a high infrared heat dissipation rate, molding the obtained ceramic material, and using the substrate as a substrate or using a heat sink instead of the heat sink. Heat from a heating element dissipates heat as radiant heat (Patent Literature 1: JP-A-2006-298703). However, when the ceramic material is high in rigidity and difficult to mold, or the surface of the heat-generating component to be placed is not flat and curved, there is a problem that it cannot be placed.

In other respects, there has been proposed a heat-dissipating method in which a composition containing particles having a high thermal emissivity in a curable resin is diluted with an appropriate organic solvent (referred to as a thermal radiation coating), and is coated or sprayed on a heating element. It is dried and hardened, and the heat radiation layer is directly laminated to the heat generating body, and heat from the heat generating body is radiated to the outside of the system (Patent Documents 2, 3: JP-A-2004-43612, JP-A-2013-144747) Bulletin). However, for the application or spraying of the heat generating body, for example, it is necessary to introduce the equipment used therefor; the management of the coating amount and the spraying amount is difficult; the step of hardening the coating material is required, and the so-called step becomes complicated.

Further, a heat-radiating sheet has been proposed which is formed by forming a heat radiation film on one surface of a thin metal plate and bonding an adhesive layer to the other surface of the metal thin plate (Patent Document 4: JP-A-2004-200199). However, the thickness of this adhesive layer is thin, and the thermal conductivity is low. When the smoothness of the surface of the heating element is high, although it is not a problem, when the surface of the heating element is rough, or when the heating element has a plurality of colors and the heights of the heating elements are different, the surface of the heating element cannot be smoothly followed, and the heat conduction of the subsequent layer is further performed. When the rate is low, it is not conducive to the transfer of heat to the heat radiation layer, and the heat dissipation effect is significantly reduced.

In view of the above, the present invention has an object of providing a thermally conductive composite sheet which is flexible and has a simple mounting step and which can follow the surface shape of the heat generating body.

In order to achieve the above object, the inventors of the present invention have found that a thermal radiation layer having a thickness of 10 μm or more and 100 μm or less is laminated on one surface of the heat conduction layer having a high thermal conductivity in the plane direction, and the thickness is laminated on the other surface. 0.2 mm or more, a thermally conductive polyanthracene resin layer having a hardness of 40 or less by Asker C, and a thermally conductive composite sheet which is flexible, has a simple mounting step, and can follow the surface shape of the heating element. The present invention has been completed.

Accordingly, the present invention provides the following thermally conductive composite sheet.

[1] A thermally conductive composite sheet obtained by laminating a heat radiation layer on one surface of a heat conduction layer and laminating a thermally conductive polyoxymethylene resin layer on the other surface, wherein the heat conduction layer is thermally conductive in a plane direction The heat radiation layer has a thickness of 10 μm or more and 100 μm or less, the heat conductive polyoxynoxy resin layer has a thickness of 0.2 mm or more, and the Asker C hardness is 40 or less.

[2] The thermally conductive composite sheet according to the above [1], wherein the thermally conductive polyanthracene resin layer is a cured product of the thermally conductive polydecane oxide composition containing the components (a) to (d), a) an organopolyoxane having an average of the following composition formula (1) and having two or more alkenyl groups bonded to a ruthenium atom in one molecule: 100 parts by mass, R _a SiO _(4-a)/2 (1) (wherein R is independently a non-substituted or substituted one-valent hydrocarbon group having 1 to 12 carbon atoms, a is a positive number of 1.8 to 2.2); (b) a thermally conductive filler: 200 to 4,000 parts by mass; c) an organic hydrogen polyoxyalkylene having two or more hydrogen atoms bonded to a halogen atom in one molecule: a hydrogen atom directly bonded to a halogen atom in the component (c) with respect to the alkenyl group in the component (a) The molar ratio is 0.5 to 5.0; (d) the platinum compound: 0.1 to 1,000 ppm of the platinum element amount as the component (a).

[3] The thermally conductive composite sheet according to the above [2], wherein the thermally conductive polyfluorene composition further comprises (f) a polyoxyxylene resin: 50 to 500 parts by mass.

[4] The thermally conductive composite sheet according to the above [3], wherein the polyfluorene oxide resin (f) is R ¹ ₃ SiO _1/2 unit (R ¹ represents an unsubstituted or substituted one-valent hydrocarbon group) (M unit) Copolymer with SiO _4/2 unit (Q unit), and the ratio of M unit to Q unit (M/Q) is 0.5 to 1.5 in molar ratio, and does not contain an aliphatic unsaturated group.

[5] The thermally conductive composite sheet according to the above [1], wherein the thermally conductive polyanthracene resin layer is a thermally conductive polysiloxane composition containing the components (b), (f), and (g). Hardened material, (b) thermally conductive filler: 100 to 3,000 parts by mass; (f) polyoxyxylene resin: 100 parts by mass; (g) organic peroxide compound: converted in organic peroxide It is 0.1 to 2 parts by mass.

[6] The thermally conductive composite sheet according to the above [5], wherein the polyfluorene oxide resin (f) is R ¹ ₃ SiO _1/2 unit (R ¹ represents an unsubstituted or substituted one-valent hydrocarbon group) (M unit) Copolymer with SiO _4/2 unit (Q unit), and the ratio of M unit to Q unit (M/Q) is 0.5 to 1.5 in molar ratio, and does not contain an aliphatic unsaturated group.

[7] The thermally conductive composite sheet according to any one of the above [2], wherein (b) the thermally conductive filler has an average particle diameter of 0.1 to 200 μm.

[8] The thermally conductive composite sheet according to any one of the above [2], wherein the thermally conductive polyfluorene composition further comprises a surface selected from the group consisting of (h-1) and (h-2) Treatment agent, (h-1): an alkoxydecane compound represented by the following general formula (2), R ² _m R ³ _n Si(OR ⁴ ) _4-mn (2) (wherein R ^{2 is} independently An alkyl group having 6 to 15 carbon atoms, R ^{3 is} independently an unsubstituted or substituted hydrocarbon having 1 to 8 carbon atoms, and R ^{4 is} independently an alkyl group having 1 to 6 carbon atoms, and m is 1 to 3 Integer, n is 0, 1 or 2, m+n is an integer from 1 to 3); (h-2): represented by the following general formula (3) and the molecular chain single end is blocked with a trialkoxyalkyl group Dimethylpolyoxane, (wherein R ^{5 is} independently an alkyl group having 1 to 6 carbon atoms, and k is an integer of 5 to 100).

[9] The thermally conductive composite sheet according to the above [1], wherein the thermally conductive polyanthracene resin layer has a thermal conductivity of 1.4 W/mK or more.

[10] The thermally conductive composite sheet according to the above [1], wherein the heat conductive layer is an aluminum foil.

[11] The thermally conductive composite sheet according to the above [1], wherein the heat conductive layer is a copper foil.

[12] The thermally conductive composite sheet according to the above [1], wherein the heat radiation layer has a thermal emissivity of 0.80 or more.

[13] The thermally conductive composite sheet according to the above [1], wherein the heat radiation layer is formed of an organic resin layer containing particles selected from the group consisting of ceramic powder, cordierite powder, and black lead.

[14] The thermally conductive composite sheet according to the above [13], wherein the particles have an average particle diameter of 0.1 to 50 μm.

The thermally conductive composite sheet of the present invention is obtained by laminating a heat radiation layer on one surface of a heat conduction layer and laminating a thermally conductive polyoxymethylene resin layer on the other surface, wherein the heat conduction layer has a thermal conductivity in a plane direction The heat radiation layer has a thickness of 10 μm or more and 100 μm or less, the heat conductive polyoxynoxy resin layer has a thickness of 0.2 mm or more, and the Asker C hardness is 40 or less, and the hardness is 200 W/mK or more. The flexible conductive sheet which is flexible and easy to install, and which can follow the surface shape of the heating element, is attached to the heating element. It is often effective to reduce the temperature of the heating element.

[Best Practice for Carrying Out the Invention] [heat conducting layer]

In the thermally conductive composite sheet of the present invention, the thermal conductivity of the heat conductive layer in the surface direction is 200 W/mK or more, preferably 200 to 2,000 W/mK. When the thermal conductivity in the surface direction of the heat conduction layer is low, the thermally conductive composite sheet of the present invention cannot obtain sufficient thermal diffusibility. When considering the use of heat radiation countermeasures, the heat dissipated will depend on the area and the heat emissivity. Therefore, the area of the sheet is not problematic in terms of mounting, and the larger it is, the more advantageous it is. At this time, the heat conduction layer can efficiently dissipate heat from the heat generating body efficiently. When the heat conductive layer is not provided, heat from the heat generating body is less likely to diffuse, and thus the advantage of increasing the sheet area cannot be exhibited. Further, in the present invention, the thermal conductivity in the surface direction of the heat conduction layer is measured by a thermo wave analyzer, and the thermal conductivity is calculated from the thermal diffusivity.

As the heat conductive layer, for example, graphite flakes or aluminum can be cited. Foil, copper foil, etc. The in-plane heat conduction of the graphite flakes is very excellent, but the bending or stretching is weak, and the workability is lacking. In addition, graphite powder is peeled off and the cost is high. Aluminum foil or copper foil is low in cost compared to graphite flakes, and is suitable because of its high strength.

[thickness of heat conducting layer]

The thickness of the heat conducting layer is preferably from 0.01 to 0.1 mm. It is preferably 0.03 to 0.1 mm, more preferably 0.03 to 0.08 mm. When the thickness of the heat conduction layer is too thin, the thermally conductive composite sheet becomes less rigid and the operation becomes difficult. Moreover, when it exceeds 0.1 mm, the softness of the heat conductive composite sheet is impaired, and it is not suitable when considering the mounting.

[thermal radiation layer]

In the thermally conductive composite sheet of the present invention, the heat emissivity of the heat radiation layer is preferably 0.80 or more, and more preferably 0.80 to 0.99. When it is less than 0.80, there is a case where sufficient heat dissipation cannot be obtained. The heat radiation layer is a ceramic powder containing a combination of cerium oxide, aluminum oxide, titanium oxide, boron nitride, aluminum nitride, or one of two or more types of particles having a high thermal emissivity such as cordierite powder or black lead. The resin layer is preferably not particularly limited as long as it has sufficient flexibility to disperse particles having a high thermal emissivity in the organic resin as long as the heat emissivity is ensured to be 0.80 or more. Further, examples of the organic resin include, but are not limited to, an acrylic resin, a polyoxyxylene resin, an epoxy resin, a urethane resin, and a polyester resin.

In the present invention, the thermal emissivity of the heat radiation layer is a value measured by a thermal emissivity measuring device (AERD Kyoto Electronics Manufacturing Co., Ltd.).

[thickness of thermal radiation layer]

The thickness of the heat radiation layer is 10 to 100 μm, preferably 20 to 50 μm. When it is thinner than 10 μm, it becomes a lack of workability. Also, make it thicker than 100μm When it becomes, it becomes less flexible.

The heat radiation layer is an organic resin layer containing the above powder, The average particle diameter of the particles used for the heat radiation layer is preferably from 0.1 to 50 μm, more preferably from 1 to 10 μm. The powder can be used in a pulverized powder state by a pulverizer such as a ball mill or a jet mill. Further, the particle diameter is a value measured by a Microtrac particle size distribution measuring apparatus MT3300EX (Nikkei Co., Ltd.). Further, the basis of the average particle diameter is a volume.

The thermal emissivity of the powder is preferably from 0.80 to 0.99, and is preferably 0.85~0.99. In addition, the particles are 40 to 200 parts by mass, and particularly preferably 50 to 150 parts by mass, based on 100 parts by mass of the organic resin. When the amount of the mixture is small, there is a case where thermal radioactivity cannot be obtained, and when it is too large, it is difficult to fill the powder.

As a heat radiation layer, a commercially available person can be used, for example, Examples thereof include Cerac α (manufactured by Cerac, heat emissivity: 0.96), Pelcool (manufactured by Pelnox; acrylic resin containing powder).

Moreover, the heat radiation layer is laminated to the heat conduction layer, For the heat radiation sheet, a commercially available one can be used, for example, an aluminum foil as a heat conduction layer and a heat radiation polyester resin as a heat radiation layer are laminated as a heat radiation sheet, and a Morgen sheet can be cited. Wait.

[Thermally conductive polyoxyl resin layer]

In the thermally conductive composite sheet of the present invention, the thermal conductivity of the thermally conductive polyanhydride resin layer is preferably 1.4 W/mK or more, and more preferably 2.0 W/mK or more. When the thermal conductivity of the thermally conductive polyoxyalkylene resin layer is less than 1.4 W/Mk At the time, there is a case where heat from the heating element cannot be efficiently transmitted to the heat conduction layer. That is, there is a case where a sufficient heat dissipation effect cannot be obtained. Although the upper limit is not particularly limited, it is usually 10 W/mK or less. This thermal conductivity can be obtained by blending a specified amount of the thermally conductive filler into a polyfluorene oxide composition using a polyoxyxylene resin layer.

In the present invention, the thermal conductivity of the thermally conductive polyanthracene resin layer is measured using a thermal conductivity meter (TPA-501, trade name manufactured by Kyoto Electronics Manufacturing Co., Ltd.).

[Thickness of Thermal Conductive Polyoxygenated Resin Layer]

The thickness of the thermally conductive polyoxymethylene resin layer is 0.2 mm or more. It is preferably 0.5 mm or more, and more preferably 1 mm or more. As can be seen from the examples described later, when the thickness of the thermally conductive polyoxymethylene resin layer is thicker, the cooling effect of the heating element at the time of mounting is greater. In this case, when the thickness of the thermally conductive polyoxynoxy resin layer is thick, it is possible to temporarily store the heat from the heat generating layer before the heat transfer layer is transferred to the heat conductive layer. When the thickness is too thin, it is difficult to obtain the effect of storing heat before being transferred to the heat radiation layer. The upper limit of the thickness is not particularly limited, but is preferably 15 mm or less, particularly preferably 10 mm or less, and particularly preferably 5 mm or less, in terms of the mass at the time of actual use.

[Hardness of Thermal Conductive Polyoxylated Resin Layer]

The hardness of the thermally conductive polyanthracene resin layer is 40 or less, preferably 30 or less, in Asker C. When the hardness exceeds 40 At the time, there is a lack of followability to the heating element, and the contact thermal resistance increases. Moreover, when mounting a plurality of highly different heating elements, the difference in height cannot be absorbed, and the heat dissipation characteristics may be lowered. The lower limit of the hardness is not particularly limited, but is preferably 3 or more, and particularly preferably 5 or more in terms of workability. The Asker C hardness can be adjusted by adjusting the polyfluorene oxide composition (which is used in a thermally conductive polyanthracene resin layer to be described later) and the organic hydrogen polyoxyalkylene content. Get it by volume.

As heat conduction for a thermally conductive polyoxyalkylene resin layer Specific examples of the polyoxymethylene composition include a thermally conductive polydecane oxide composition (A) or a thermally conductive polydecane oxide composition (B).

The thermally conductive polyfluorene composition (A) is obtained by containing the following components (a) to (d), and (a) is represented by the following average composition formula (1) and has two or more bonds in one molecule. An organopolyoxyalkylene group of an alkenyl group of a halogen atom: 100 parts by mass, R _a SiO _(4-a)/2 (1) (wherein R is independently an unsubstituted or substituted one having a carbon number of 1 to 12; a hydrocarbon group, a is a positive number of 1.8 to 2.2); (b) a thermally conductive filler: 200 to 4,000 parts by mass; (c) an organic hydrogen polyoxyalkylene having two or more hydrogen atoms bonded to a halogen atom in one molecule With respect to the alkenyl group in the component (a), the molar ratio of the hydrogen atom directly bonded to the halogen atom in the component (c) is 0.5 to 5.0; (d) the platinum compound: the amount of the platinum group element is (a) 0.1 to 1,000 ppm of the component.

The thermally conductive polyfluorene composition (B) is composed of the following components (b), (f), and (g), and (b) a thermally conductive filler: 100 to 3,000 parts by mass; (f) a polyoxyl resin. 100 parts by mass; (g) organic peroxide compound: 0.1 to 2 parts by mass in terms of organic peroxide.

Hereinafter, each component of the above thermally conductive polyfluorene oxide composition (A) will be described.

[(a) Organic Polyoxane]

The alkenyl group-containing organopolyoxane of the component (a) is an organopolyoxane having an average composition formula (1) and having two or more alkenyl groups bonded to a ruthenium atom in one molecule. Preferably, it has 2 to 100 alkenyl groups bonded to a ruthenium atom in one molecule, R _a SiO _(4-a)/2 (1) (wherein R is independently an unsubstituted or 1 to 12 carbon atom or Substituting a monovalent hydrocarbon group, a is a positive number from 1.8 to 2.2, preferably a positive number from 1.95 to 2.05)

The component (a) is a main component (matrix polymer) in the addition reaction hardening composition. In general, the main chain portion is generally formed by repeating a diorganooxane unit, which may include a branched structure in a part of the molecular structure, or may be a ring body, but In terms of mechanical strength and the like of the cured product, a linear diorganopolyoxyalkylene is preferable.

In the above formula (1), R is a homologous or heterogeneous carbon atom having 1 to 12, and an unsubstituted or substituted one-valent hydrocarbon group of 1 to 10 is used as Examples of the functional group bonded to the alkenyl group of the halogen atom include, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, and the like. An alkyl group such as heptyl, octyl, decyl, decyl or dodecyl, a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group or a cycloheptyl group, a phenyl group, a tolyl group, a xylyl group or a naphthyl group; An aryl group such as a biphenyl group or the like, an aralkyl group such as a benzyl group, a phenethyl group, a phenylpropyl group or a methylbenzyl group, and a hydrogen atom bonded to a carbon atom of the group are partially or wholly fluorine-containing a halogen atom such as chlorine or bromine, or a substituted group such as a cyano group, for example, a chloromethyl group, a 2-bromoethyl group, a 3-chloropropyl group, a 3,3,3-trifluoropropyl group, a chlorophenyl group, or a fluorine group. Phenyl, cyanoethyl, 3,3,4,4,5,5,6,6,6-nonafluorohexyl, etc., typically represented by a carbon number of 1 to 10, particularly representative of a carbon number of 1 to 6 Preferably, the methyl group, the ethyl group, the propyl group, the chloromethyl group, the bromoethyl group, the 3,3,3-trifluoropropyl group, the cyanoethyl group, etc. are unsubstituted or substituted with 1 to 3 carbon atoms. An unsubstituted or substituted phenyl group such as an alkyl group and a phenyl group, a chlorophenyl group, a fluorophenyl group or the like. Further, the functional groups other than the alkenyl group bonded to the ruthenium atom may be the same or different.

Further, examples of the alkenyl group include a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a butenyl group, a hexenyl group, and a cyclohexenyl group. Usually, the number of carbon atoms is about 2 to 8, and Among them, a lower alkenyl group such as a vinyl group or an allyl group is preferred, and a vinyl group is particularly preferred.

The organic polyoxyalkylene has a dynamic viscosity at 25 ° C, usually 10 to 100,000 mm ² /s, particularly preferably 500 to 50,000 mm ² /s. When the dynamic viscosity is too low, the storage stability of the obtained composition may be deteriorated, and when it is too high, the stretchability of the obtained composition may be deteriorated. Further, in the present invention, the dynamic viscosity can be measured by an Oswald viscometer.

The organopolyoxane of the component (a) may be used alone or in combination of two or more kinds having different dynamic viscosities.

[(b) Thermal Conductive Filler]

As the thermally conductive filler filled in the thermally conductive polyfluorene composition, non-magnetic metals such as copper or aluminum, alumina, cerium oxide, magnesium oxide, bengala, cerium oxide, and titanium oxide can be used. Metal oxides such as zirconium oxide and zinc white, metal nitrides such as aluminum nitride, tantalum nitride, and boron nitride; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; artificial diamonds or tantalum carbide; It is used as a material for heat conduction filler. The heat conductive filler may be used alone or in combination of two or more.

The average particle diameter of the heat conductive filler is preferably 0.1~ 200 μm, preferably 0.1 to 100 μm, more preferably 0.5 to 50 μm. The average particle diameter described herein is a value measured by a Microtrac particle size distribution measuring apparatus MT3300EX (Nikkiso). Further, the basis of the average particle diameter is a volume.

As a thermally conductive filler, compared to (a) The component is 100 parts by mass, preferably 200 to 4,000 parts by mass, more preferably 200 to 3,000 parts by mass. When the amount of the thermally conductive filler is too small, the thermally conductive resin layer may not have sufficient thermal conductivity. When the amount is too large, the formability is deteriorated and the adhesiveness is lowered.

[(c) organic hydrogen polyoxyalkylene]

The organic hydrogen polyoxyalkylene of the component (c) is an organic hydrogen polyoxyalkylene having two or more hydrogen atoms bonded to a halogen atom (i.e., SiH group) in one molecule, preferably having 2 in one molecule. ~100 are bonded to a hydrogen atom of a halogen atom, and for the component (a), the component (c) acts as a component of a crosslinking agent. That is, in the presence of a component (d) (platinum compound) described later, a hydrogen atom bonded to a halogen atom in the component (c) is added to the alkene in the component (a) by a hydrogenation reaction. And forming a crosslinked hardened structure having a three-dimensional network structure having a crosslinked bond.

As the organic group bonded to the ruthenium atom in the component (c), For example, an unsubstituted or substituted monovalent hydrocarbon group which does not have an aliphatic unsaturated bond, or the like can be mentioned. Specifically, the unsubstituted or substituted one-valent hydrocarbon group which is the same as the substituent bonded to the ruthenium atom other than the aliphatic unsaturated group in the description of the component (a) may be mentioned. From the viewpoint of easiness and economy, a methyl group is preferred.

The structure of the organohydrogen polyoxyalkylene of component (c) in the present invention The production is not particularly limited, and may be any linear, branched or cyclic, and is preferably linear.

Further, the degree of polymerization of the organohydrogen polyoxyalkylene (the number of ruthenium atoms) is preferably from 2 to 100, particularly preferably from 2 to 50.

Suitable for organic hydrogen polyoxane as component (c) For example, a methylhydrogenpolyoxyalkylene terminated with a trimethylphosphonoalkyl group at both ends of the molecular chain, and a dimethyloxyalkylene group terminated with a trimethylphosphonium group at both ends of the molecular chain a hydrogen hydroxane copolymer, three ends of the molecular chain a methyl methoxyalkyl group-terminated dimethyl methoxy oxane ‧ methylhydroquinone oxymethyl phthalate copolymer, two ends of the molecular chain terminated with a dimethylhydroquinone oxyalkyl group Methyl polyoxyalkylene, a dimethyl oxane ‧ methyl hydrazine copolymer terminated with a dimethyl hydroquinone oxyalkyl group at both ends of the molecular chain, and dimethyl hydroquinone at both ends of the molecular chain a dimethyl methoxy oxane ‧ methylphenyl fluorene copolymer which is blocked by an alkyl group, a methyl phenyl polyoxyalkylene which is terminated with a dimethyl hydroquinone oxyalkyl group at both ends of the molecular chain, and the like. In addition, the organic hydrogen polyoxyalkylene of the component (c) may be used alone or in combination of two or more.

(c) the amount of ingredients, relative to (a) The alkenyl group 1 is preferably such that the SiH group in the component (c) is preferably 0.5 to 5.0 moles, more preferably 0.8 to 4.0 moles. When the amount of the SiH group in the component (c) is less than 0.5 mol with respect to the alkenyl group 1 in the component (a), the composition may not be hardened or the strength of the cured product may be insufficient, and A problem of a problem such as a molded body or a composite operation. On the other hand, when the amount exceeds 5.0 moles, the adhesion of the surface of the cured product is insufficient.

[(d) platinum compound]

The platinum-based compound of the component (d) is an addition reaction for promoting an alkenyl group in the component (a) and a hydrogen atom bonded to a halogen atom in the component (c), and is used to convert the composition of the present invention into a composition. The catalytic component of the crosslinked hardened material of the three-dimensional network structure.

The component (d) can be appropriately selected from the conventional catalysts used in the general hydrogenation reaction. Specific examples of the platinum group metal such as platinum (including platinum black), ruthenium, and palladium; H ₂ PtCl ₄ ‧nH ₂ O, H ₂ PtCl ₆ ‧nH ₂ O, NaHPtCl ₆ ‧nH ₂ O , KHPtCl ₆ ‧nH ₂ O, Na ₂ PtCl ₆ ‧nH ₂ O, K ₂ PtCl ₄ ‧nH ₂ O, PtCl ₄ ‧nH ₂ O, PtCl ₂ , Na ₂ HPtCl ₄ ‧nH ₂ O (but n in the formula Is an integer of 0 to 6, preferably 0 or 6), such as platinum chloride, chloroplatinic acid, and chloroplatinate; alcohol-denatured chloroplatinic acid; chloroplatinic acid and olefin complex; A platinum group metal such as platinum black or palladium is supported on a carrier such as alumina, ruthenium oxide or carbon; a ruthenium-olefin complex; a chloroform (triphenylphosphine) ruthenium (Wilkinson catalyst) Platinum chloride, chloroplatinic acid, chloroplatinate and a vinyl-containing alkane complex. These platinum compounds may be used alone or in combination of two or more.

The amount of the platinum compound of the above component (d) is as long as It is sufficient to harden the composition to a desired effective amount, and is usually 0.1 to 1,000 ppm, preferably 0.5 to 500 ppm, based on the mass of the platinum group metal element of the component (a).

[(e) Reaction Control Agent]

The reaction control agent of the component (e) is a component which is formulated as needed, and is used for adjusting the addition reaction of the component (a) and the component (c) in the presence of the component (d) (hydrogenated alkylation) The speed of the reaction). The reaction controlling agent of the component (e) can be appropriately selected from the conventional addition reaction controlling agents used in the general addition reaction-curable polyfluorene composition. As such a specific example, an acetylene compound such as 1-ethynyl-1-cyclohexanol, 3-butyn-1-ol or ethynylmethylenemethanol, or a nitridation compound is used. , organic phosphorus compounds, sulfur compounds, antimony compounds, organochlorine compounds, and the like. These addition reaction control agents may be used alone or in combination of two or more.

The amount of the above component (e) will be adjusted according to the component (d). The amount varies, so it cannot be fixed. It suffices that it is sufficient to adjust the hydrogenation oximation reaction to a desired reaction rate. In general, the mass of the component (a) may be set to about 10 to 50,000 ppm. When the amount of the component (e) is too small, the storage stability of the composition may be insufficient, and sufficient use time may not be ensured. Conversely, when the amount is too large, the hardenability of the composition may be lowered.

[(f) polyoxyl resin]

The polyoxynoxy resin of the component (f) has an effect of imparting adhesiveness to the surface of the cured product of the thermally conductive polysiloxane composition after curing. As an example of such a component (f), for example, a copolymer of R ¹ ₃ SiO _1/2 unit (M unit) and SiO _4/2 unit (Q unit), and a ratio of M unit to Q unit (mole) The ratio of M/Q is 0.5 to 1.5 polyoxyl resin, and M/Q is preferably 0.6 to 1.4, more preferably 0.7 to 1.3. When the above M/Q is in the above range, a desired adhesive force can be obtained. In this case, R ¹ ₂ SiO _2/2 units (D units) or R ¹ SiO _3/2 units (T units) may be included as needed, but the arrangement of the D units and the T units is preferably 15 moles. Below %, it is particularly preferably 10% or less.

In the general formula representing the above M unit, etc., R ^{1 is an} unsubstituted or substituted monovalent hydrocarbon group, and preferably an unsubstituted or substituted one-valent hydrocarbon group which does not contain an aliphatic unsaturated bond. As an example of such R ¹ , for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, octyl are listed. An alkyl group such as a fluorenyl group, a fluorenyl group, a decyl group or a dodecyl group; a cycloalkyl group such as a cyclopentyl group, a cyclohexyl group or a cycloheptyl group; a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a biphenyl group, etc. An aralkyl group such as an aryl group, a benzyl group, a phenethyl group, a phenylpropyl group, a methylbenzyl group, or the like, and a part or all of a hydrogen atom bonded to a carbon atom of the group are partially or completely protected by fluorine, chlorine or bromine. a halogen atom, a cyano group or the like substituted, for example, chloromethyl, 2-bromoethyl, 3-chloropropyl, 3,3,3-trifluoropropyl, chlorophenyl, fluorophenyl, cyanide The number of carbon atoms such as ethyl, 3,3,4,4,5,5,6,6,6-nonafluorohexyl is 1 to 12, preferably 1 to 6 carbon atoms.

As R ¹ , among these, a carbon number of 1 to 3 such as a methyl group, an ethyl group, a propyl group, a chloromethyl group, a bromoethyl group, a 3,3,3-trifluoropropyl group or a cyanoethyl group is preferable. An unsubstituted or substituted alkyl group, and an unsubstituted or substituted phenyl group such as a phenyl group, a chlorophenyl group, a fluorophenyl group or the like. Also, R ¹ may all be the same or different. In the case where special characteristics such as solvent resistance are not required, R ^{1 is} preferably all methyl groups from the viewpoints of cost, ease of availability, chemical stability, environmental burden, and the like.

When blending the component (f), it is 100 mass relative to the component (a) The blending amount is preferably from 50 to 500 parts by mass, more preferably from 60 to 350 parts by mass, still more preferably from 70 to 250 parts by mass. When the amount of the component (f) is less than 50 parts by mass or more than 500 parts by mass, the desired adhesiveness may not be obtained.

Further, the component (f) itself is a solid or viscous liquid at room temperature, and can also be used in a state of being dissolved in a solvent. In this case, the amount of the composition added should be determined by the amount of the solvent removed.

Next, each component of the above thermally conductive polyfluorene oxide composition (B) will be described.

[(b) Thermal Conductive Filler]

The thermally conductive filler as the component (b) can be exemplified by the same as the thermally conductive filler of the above thermally conductive polyfluorene oxide composition (A).

The amount of the thermally conductive filler to be added is preferably from 100 to 3,000 parts by mass, more preferably from 200 to 2,500 parts by mass, per 100 parts by mass of the component (f) to be described later. When the amount of the thermally conductive filler is too small, the thermally conductive polyanhydride resin layer may not have sufficient thermal conductivity. When the amount is too large, the formability is deteriorated and the adhesiveness is lowered.

[(f) polyoxyl resin]

The polyoxynoxy resin as the component (f) can be exemplified by the same as the polyoxyxylene resin of the above thermally conductive polyfluorene oxide composition (A).

[(g) Organic peroxide compound]

The hardening reaction of the polyoxonium composition of the organic peroxide is such that one or both of the molecular chain ends (single-end or both ends) and the molecular chain non-terminal are straight, and the alkenyl group having a vinyl group or the like is straight. Chain-like organopolyoxane is subjected to radical polymerization in the presence of an organic peroxide compound Start. The organic peroxide compound as the component (g) is, for example, a dimercapto peroxide or a dialkyl peroxide. Since the organic peroxide compound is weak to light or heat and is not stable, it is difficult to disperse the solid organic peroxide compound in the composition, so that it is diluted in an organic solvent or dispersed in a polyoxonium component. There are many users in the state.

The amount of organic peroxide compound, relative to (f) 100 parts by mass of the polyoxyxylene resin is preferably 0.1 to 2 parts by mass, more preferably 0.1 to 1.6 parts by mass, in terms of organic peroxide. When the amount of the mixture is too small, the hardening reaction may not be sufficiently performed. When the amount is too large, the composition may be inferior in stability.

[Other ingredients]

The thermally conductive polydecane oxide composition constituting the thermally conductive polyanthracene resin layer may be added to components other than the above components as needed, without departing from the object of the present invention.

Heat conductive polyfluorene composition, hydrophobized treatment group The thermally conductive filler of the component (b) at the time of preparation of the composition is used to enhance the aggregation of the organopolyoxane of the component (a) in the composition (A) or the component (f) in the composition (B) The wettability of the epoxy resin is such that the thermally conductive filler is uniformly dispersed in the matrix formed of the component (a) or the component (f), and a surface treatment agent (wetting agent/wetter) (h) can be blended. As the component (h), the following components (h-1) and (h-2) are particularly preferred.

(h-1): an alkoxydecane compound represented by the following general formula (2), R ² _m R ³ _n Si(OR ⁴ ) _4-mn (2) (wherein R ^{2 is} independently a carbon number 6 to 15 alkyl, R ^{3 is} independently an unsubstituted or substituted hydrocarbon having 1 to 8 carbon atoms, R ^{4 is} independently an alkyl group having 1 to 6 carbon atoms, and m is an integer of 1 to 3, n Is 0, 1 or 2, and m+n is an integer from 1 to 3.)

In the above general formula (2), examples of the alkyl group represented by R ² include a hexyl group, an octyl group, a decyl group, a decyl group, a dodecyl group, and a tetradecyl group. When the number of carbon atoms of the alkyl group represented by R ² is in the range of 6 to 15, the wettability of the thermally conductive filler of the component (b) can be sufficiently improved, and the workability of the operation is improved. Therefore, the low temperature characteristics of the composition are good.

In addition, examples of the unsubstituted or substituted monovalent hydrocarbon group represented by the above R ³ include an alkyl group such as a methyl group, an ethyl group, a propyl group, a hexyl group, and an octyl group; and a ring such as a cyclopentyl group or a cyclohexyl group. An alkyl group; an alkenyl group such as a vinyl group or an allyl group; an aryl group such as a phenyl group or a tolyl group; an aralkyl group such as a 2-phenethyl group or a 2-methyl-2-phenylethyl group; A halogenated hydrocarbon group such as 3-trifluoropropyl group, 2-(nonafluorobutyl)ethyl group, 2-(heptadecafluorooctyl)ethyl group or p-chlorophenyl group. In the present invention, among these, methyl and ethyl are particularly preferred.

The alkyl group represented by the above R ⁴ may, for example, be a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group or a hexyl group. In the present invention, among these, methyl and ethyl are particularly preferred.

Specific examples of suitable components of the above (h-1) include the following.

C ₆ H ₁₃ Si(OCH ₃ ) ₃

C ₁₀ H ₂₁ Si(OCH ₃ ) ₃

C ₁₂ H ₂₅ Si(OCH ₃ ) ₃

C ₁₂ H ₂₅ Si(OC ₂ H ₅ ) ₃

C ₁₀ H ₂₁ Si(CH ₃ )(OCH ₃ ) ₂

C ₁₀ H ₂₁ Si(C ₆ H ₅ )(OCH ₃ ) ₂

C ₁₀ H ₂₁ Si(CH ₃ )(OC ₂ H ₅ ) ₂

C ₁₀ H ₂₁ Si(CH=CH ₂ )(OCH ₃ ) ₂

C ₁₀ H ₂₁ Si(CH ₂ CH ₂ CF ₃ )(OCH ₃ ) ₂

The above-mentioned (h-1) component may be used alone or in combination of two or more. The blending amount of the component (h-1) is not economical because the addition amount exceeds the blending amount described later, since the wetting effect is limited and cannot be increased. Further, since the component is volatile, the composition and the cured product after hardening are gradually hardened when placed in an open system, so that it is preferably stopped at a minimum required amount.

(h-2): a dimethyl polyoxane represented by the following general formula (3) and having a single chain terminal terminated with a trialkoxyalkylene group, (In the formula, R ^{5 is} independently an alkyl group having 1 to 6 carbon atoms, and is the same as the alkyl group represented by R ⁴ in the above formula (2), and k is an integer of 5 to 100).

As a suitable specific example of the above (h-2) component, it can be listed As described below.

Still, (h-2) ingredients can be used alone or in groups Use in combination of two or more. When the blending amount of the component (h-2) exceeds the blending amount described later, the heat resistance or moisture resistance of the obtained cured product tends to decrease.

In the present invention, as the surface treatment agent of the component (b), At least one selected from the group consisting of the above (h-1) component and (h-2) component is selected for use. In this case, the blending amount of the total (h) component in the composition (A) is preferably 0.01 to 50 parts by mass, particularly preferably 0.1 to 30 parts by mass, per 100 parts by mass of the component (a). In addition, the blending amount of the total (h) component in the component (B) is preferably 0.01 to 50 parts by mass, particularly preferably 0.1 to 30 parts by mass, per 100 parts by mass of the component (f).

In the present invention, as another arbitrary component, an addition example may be added. For example, a fluorine-denatured polyfluorene surfactant, carbon black as a colorant, titanium dioxide, or the like. Further, for the purpose of anti-settling or reinforcing of the heat-conductive filler, fine powder cerium oxide such as precipitated cerium oxide or cerium oxide or the like, and a thixotropic enhancer may be appropriately added.

a thermally conductive polyfluorene composition by using the above (a) The component (d), or the components (b), (f), (g), and other components required for the reaction are mixed and prepared according to a usual method.

Further, the curing conditions of the thermally conductive polyfluorene oxide composition may be the same as those of the conventional addition reaction hardening type polyoxyxene rubber composition or organic peroxide hardening type polyoxymethylene rubber composition.

[Method of Manufacturing Thermal Conductive Composite Sheet]

The thermally conductive composite sheet of the present invention is obtained by laminating a heat radiation layer on a heat conduction layer to form a heat radiation sheet, and then laminating a heat conductive polyoxymethylene resin layer on the heat radiation sheet. The method of laminating the heat radiation layer on the heat conduction layer may, for example, be a coating method, but is not limited thereto. Further, the method of laminating the thermally conductive polyanthracene resin layer may, for example, be a bonding method, a coating method, a pressing method, or the like, but is not limited thereto.

The thermally conductive composite sheet of the invention can be effectively used Portable electronic terminals such as smart phones or digital cameras, or LED lighting.

[Examples]

The present invention will be specifically described below by showing examples and comparative examples, but the present invention is not limited to the following examples.

In the case of carrying out the examples and the comparative examples, the method of molding the thermally conductive composite sheet is as follows.

(thermal conduction layer)

Aluminum foil: thickness 50μm, thermal conductivity in the plane direction 236W/mK

Copper foil: thickness 30μm, thermal conductivity in the plane direction 398W/mK

(thermal radiation sheet formed by laminating a heat radiation layer to a heat conduction layer)

(I-1): Cerac α (thermal radiation layer: thermal emissivity: 0.96, polyfluorene oxide containing alumina having an average particle diameter of 5 μm, manufactured by Ceramission) laminated to aluminum foil (heat-conducting layer) : A thermal radiation sheet formed by a thickness of 50 μm.

(I-2): A thermal radiation sheet obtained by laminating Cerac α (thermal radiation layer: heat emissivity: 0.96, manufactured by Ceramission) having a thickness of 30 μm onto a copper foil (heat conductive layer: thickness: 30 μm).

(I-3): Morgen sheet MG01-S (light) mechanism; thermal radioactive polyethylene resin with a thickness of 30 μm and a thermal emissivity of 0.99 on an aluminum foil with a thickness of 60 μm and a thermal conductivity of 230 W/mK (including A heat-radiating sheet of a black lead polyester resin having an average particle diameter of 1 μm).

(thermal conductive polyoxyl resin layer)

(II-1) to (II-4): a thermally conductive polyanthracene resin layer having Asker C hardness and thermal conductivity as shown in the following table.

The thermally conductive composite sheet is obtained by bonding the above-mentioned heat radiation sheet and the above-mentioned thermally conductive polyoxymethylene resin layer.

For comparison, the following (II-5) to (II-7) were also used in combination with a heat radiation sheet: (II-5) a non-thermally conductive polyoxynoxy resin layer (thermal conductivity: 0.16 W/mK); (II-6) Thermally conductive polyfluorene double-sided tape (thermal conductivity 1.0W/mK); (II-7) acrylic double-sided adhesive band.

The composition of the compositions (ii-1) to (ii-7) constituting the resin layers (II-1) to (II-7) is as follows.

[(a) Alkenyl group-containing organopolyoxane]

An organopolyoxane represented by the following formula, (X is a vinyl organopolyoxane, and p is a number which makes the organic polyoxyalkylene have a dynamic viscosity at 25 ° C as follows).

(a-1) Viscosity: 600mm ² /s

(a-2) Viscosity: 30,000 mm ² /s

[(b) Thermal Conductive Filler]

(b-1) Aluminum hydroxide powder having an average particle diameter of 30 μm

(b-2) alumina powder having an average particle diameter of 50 μm

(b-3) alumina powder having an average particle diameter of 10 μm

[(c) organic hydrogen polyoxyalkylene]

An organohydrogen polyoxyalkylene represented by the following formula, (Average polymerization degree: q=28, r=2).

[(d) platinum compound]

5 mass% chloroplatinic acid 2-ethylhexanol solution

[(e) Reaction Control Agent]

Ethynylmethylenemethanol

[(f) polyoxyl resin]

A toluene solution (non-volatile content 60) of a polyfluorene-based resin (Me is a methyl group, M/Q molar ratio of 1.15) formed of only Me ₃ SiO _0.5 unit (M unit) and SiO ₂ unit (Q unit). Mass%, viscosity 30mm ² /s).

[(h) surface treatment agent]

It is represented by the following formula (average degree of polymerization 30), and a dimethylpolysiloxane having a single terminal terminated with a trimethoxydecyl group.

The polyoxymethylene composition (ii-5) comprises: (a) a polyfluorene oxide resin composed only of Me ₃ SiO _0.5 unit (M unit) and SiO ₂ unit (Q unit) (Me represents a methyl group, M) a toluene solution having a /Q molar ratio of 1.15) (nonvolatile content 60% by mass, viscosity 30 mm ² /s), (b) an average degree of polymerization of 8,000 dimethylpolyfluorene sealed with dimethylvinyl groups at both ends Oxane, (propyl) ethynyl methylene methanol, (but) in formula (5), q = 1, r = 40 organic hydrogen polyoxane, (pent) 5 mass% chloroplatinic acid 2-B A solution of hexanol and (hexyl) toluene in mass ratio of (A) / (B) / (C) / (D) / (W) / (H) = 65 / 20 / 0.05 / 0.15 / 0.1 / 14.7 Polyoxygenated adhesive composition.

Composition (ii-7) comprising: (g) 2-ethylhexyl acrylate, (octyl)acrylic acid, (壬)hexanediol diacrylate, in mass ratio (g) / (xin) / (壬) = 97/3/0.03 acrylic resin composition.

[Modulation Method of Resin Composition]

The above resin composition was obtained by kneading using a planetary mixer.

[Method of Forming Resin Layer]

(ii-1) to (ii-3): The obtained composition was poured into a fluorine-treated film, and the mold was used to have a specified thickness, and press hardening was performed at 120 ° C/10 minutes.

(ii-4) to (ii-6): The obtained composition was applied onto a fluorine-treated film so as to have a predetermined thickness, and the solvent was dried at 80 ° C/10 min and hardened at 120 ° C/10 min.

(ii-7): The obtained composition was applied onto a fluorine-treated film to be cured by irradiation with a UV lamp having a center wavelength of 360 nm.

[Method of Making Composite Sheet]

The composite heat sheets were prepared by laminating various heat radiation sheets and various resin layers as shown in the following table, and were evaluated using the following evaluation methods.

〔evaluation method〕

15W of electric power was applied to an aluminum flat plate having a size of 30×120 mm and a thickness of 2 mm and heated. When the temperature reached a certain temperature (64 to 66 ° C), a composite sheet having a size of 30×100 mm was attached to an aluminum flat plate, and after measuring 1 minute, The temperature of the aluminum plate. Still, the measurement environment is 25 ± 2 ° C and the humidity is 50% ± 5%.

[Examples 1 to 7 and Comparative Examples 1 to 5]

As shown in the first to seventh embodiments, the "heat-conducting layer" having a thermal conductivity of 200 W/mK or more in the in-plane has a thickness of 10 to 100 μm, preferably a thermal radiation layer having a thermal emissivity of 0.80 or more. The heat radiation sheet is formed, and the heat transfer layer side of the heat radiation sheet is laminated to have a thickness of 0.2 mm or more and the Asker C (Asker C) 40 or less, preferably a thermal conductivity of 1.4 W/mK or more. The polyoxygenated resin layer can obtain the cooling effect of the heat source. In particular, the thermal conductivity of the thermally conductive polydecane oxide layer is high, and the effect of lowering the thickness of the heat source is higher.

As shown in Comparative Examples 1 and 2, when the thermal conductivity of the laminate is non- When the polyoxynene resin layer is often low to the heat radiation sheet, heat from the heat source cannot be efficiently transferred to the heat radiation layer. As shown in Comparative Examples 3 and 4, when the Asker C hardness exceeds 40, the cooling effect becomes small. As shown in Comparative Example 5, when an acrylic double-sided adhesive tape is used, not only heat from a heat source cannot be efficiently transferred to the heat conductive layer, but since the acrylic resin is less heat-resistant than the polyoxyn resin, it is directly The long-term reliability of the contact with the heat source is unstable.

Claims (14)

A thermally conductive composite sheet obtained by laminating a heat radiation layer on one surface of a heat conduction layer and laminating a heat conductive polyoxynoxy resin layer on the other surface, wherein the heat conduction layer has a thermal conductivity of 200 W/in the plane direction. In the case of mK or more, the heat radiation layer has a thickness of 10 μm or more and 100 μm or less, and the heat conductive polyoxynoxy resin layer has a thickness of 0.2 mm or more and an Asker C hardness of 40 or less. The thermally conductive composite sheet according to claim 1, wherein the thermally conductive polyanthracene resin layer is a cured product of the thermally conductive polyfluorene oxide composition containing the components (a) to (d), (a) averaged as follows An organopolyoxane having two or more alkenyl groups bonded to a halogen atom in one molecule: 100 parts by mass, R _a SiO _(4-a)/2 (1) (formula) Wherein R is independently a non-substituted or substituted one-valent hydrocarbon group having 1 to 12 carbon atoms, a is a positive number of 1.8 to 2.2); (b) a thermally conductive filler: 200 to 4,000 parts by mass; (c) one molecule An organic hydrogen polyoxyalkylene having two or more hydrogen atoms bonded to a halogen atom: the molar ratio of the hydrogen atom directly bonded to the halogen atom in the component (c) relative to the alkenyl group in the component (a) is (a) a platinum-based compound: 0.1 to 1,000 ppm of the platinum element amount as the component (a). The thermally conductive composite sheet according to claim 2, wherein the thermally conductive polyfluorene composition further comprises (f) a polyoxyxylene resin: 50 to 500 parts by mass. The thermally conductive composite sheet according to claim 3, wherein the polyfluorene oxide resin (f) is R ¹ ₃ SiO _1/2 unit (R ¹ represents an unsubstituted or substituted one-valent hydrocarbon group) (M unit) and SiO _4/2 The copolymer of the unit (Q unit), and the ratio of M unit to Q unit (M/Q) is 0.5 to 1.5 in molar ratio, and does not contain an aliphatic unsaturated group. The thermally conductive composite sheet according to claim 1, wherein the thermally conductive polyanthracene resin layer is a cured product of a thermally conductive polysiloxane composition comprising the components (b), (f), and (g), (b) Thermal conductive filler: 100 to 3,000 parts by mass; (f) polyoxyl resin: 100 parts by mass; (g) organic peroxide compound: 0.1 to 2 parts by mass in terms of organic peroxide. The thermally conductive composite sheet according to claim 5, wherein the polyfluorene oxide resin (f) is R ¹ ₃ SiO _1/2 unit (R ¹ represents an unsubstituted or substituted one-valent hydrocarbon group) (M unit) and SiO _4/2 The copolymer of the unit (Q unit), and the ratio of M unit to Q unit (M/Q) is 0.5 to 1.5 in molar ratio, and does not contain an aliphatic unsaturated group. The thermally conductive composite sheet according to any one of claims 2 to 6, wherein (b) the thermally conductive filler has an average particle diameter of 0.1 to 200 μm. The thermally conductive composite sheet according to any one of claims 2 to 6, wherein the thermally conductive polyfluorene composition further comprises a surface treatment agent selected from the group consisting of (h-1) and (h-2), (h-1) ): an alkoxydecane compound represented by the following general formula (2), R ² _m R ³ _n Si(OR ⁴ ) _4-mn (2) (wherein R ^{2 is} independently a carbon number of 6 to 15) The alkyl group, R ^{3 is} independently an unsubstituted or substituted one-valent hydrocarbon group having 1 to 8 carbon atoms, R ^{4 is} independently an alkyl group having 1 to 6 carbon atoms, m is an integer of 1 to 3, and n is 0 or 1. Or 2, m+n is an integer of 1 to 3); (h-2): dimethyl polyfluorene represented by the following general formula (3) and having a single terminal of the molecular chain terminated with a trialkoxyalkylene group Oxytomane, (wherein R ^{5 is} independently an alkyl group having 1 to 6 carbon atoms, and k is an integer of 5 to 100). The thermally conductive composite sheet according to claim 1, wherein the thermally conductive polyoxyalkylene resin layer has a thermal conductivity of 1.4 W/mK or more. The thermally conductive composite sheet of claim 1, wherein the heat conductive layer is an aluminum foil. The thermally conductive composite sheet of claim 1, wherein the heat conductive layer is a copper foil. The thermally conductive composite sheet according to claim 1, wherein the heat radiation layer has a thermal emissivity of 0.80 or more. The thermally conductive composite sheet according to claim 1, wherein the heat radiation layer is formed of an organic resin layer containing particles selected from the group consisting of ceramic powder, cordierite powder, and black lead. The thermally conductive composite sheet according to claim 13, wherein the particles have an average particle diameter of 0.1 to 50 μm.