JP5454300B2 - HEAT CONDUCTIVE SHEET, ITS MANUFACTURING METHOD, AND HEAT DISCHARGE DEVICE USING SAME - Google Patents

Description

  The present invention relates to a heat conductive sheet, a manufacturing method thereof, and a heat dissipation device using the same.

  In recent years, the wiring density and the mounting density of electronic components in multilayer wiring boards and semiconductor packages have increased, and semiconductor elements have been highly integrated, and the amount of heat generated per unit area of such heating elements has increased. Therefore, a technique for improving the efficiency of heat dissipation from the heating element is desired.

  As a general method of heat dissipation, a heat transfer grease or heat transfer sheet is sandwiched and adhered between a heating element such as a semiconductor package and a heat dissipation element made of aluminum or copper to transfer heat to the outside. Has been. From the viewpoint of workability when assembling the heat dissipation device, the heat conductive sheet is superior to the heat conductive grease. For this reason, various developments for heat conductive sheets have been studied.

For example, for the purpose of improving thermal conductivity, various thermal conductive composite compositions in which thermally conductive inorganic particles are blended in a matrix material and molded products thereof have been proposed. Substances used as thermally conductive inorganic particles are roughly divided into electrically conductive substances such as carbon, silver and copper, and electrically insulating substances such as alumina, silica, aluminum nitride and boron nitride. The However, since electrically conductive substances may cause a short circuit when they are used in the vicinity of the wiring, an electrically insulating substance is often used.
As a sheet composed of a heat conductive composite composition in which such electrically insulating and heat conductive inorganic particles are blended in a matrix material, for example, the particle thickness is more than 1.4 μm and the specific surface area is An insulating heat dissipation sheet made of a composition in which boron nitride powder of less than 2.6 m ² / g is blended with silicone rubber has been proposed (see, for example, Patent Document 1).

In addition, a thermally conductive sheet made of a polymer composition filled with boron nitride powder, in which boron nitride powder is magnetically oriented in a certain direction, has also been proposed (see, for example, Patent Document 2). .
Further, heat conduction obtained by laminating a plurality of primary sheets formed from a kneaded mixture of binder resin and inorganic filler particles, and slicing the obtained laminate in a direction perpendicular to the lamination surface (See, for example, Patent Documents 3 and 4).

  In recent years, heat conductive sheets have been applied to various heat dissipation devices, and it has become necessary to add not only high heat conductivity but also performance such as unevenness absorption and stress relaxation to the heat conductive sheet. For example, when applying heat dissipation from a large-area heating element such as a display panel, the thermal conductive sheet relaxes the thermal stress caused by the distortion of each surface of the heating element and the radiator, absorption of irregularities, and the difference in thermal expansion coefficient. Function is required. In addition, there is also a demand for high thermal conductivity that can transfer heat even when the film is formed as a thick film to some extent, and high flexibility that can be in close contact with the surfaces of the heating element and the heat dissipation element. However, since it is difficult for the conventional heat conductive sheet to achieve a high level of flexibility, strength, and heat conductivity, further development is required.

Japanese Patent No. 329839 JP 2002-080617 A JP 2002-026202 A JP 2008-280496 A

  In the heat dissipation conductive sheet disclosed in Patent Document 1, the thermal conductivity is improved only by means for blending thermally conductive inorganic particles into the matrix material. Therefore, in order to achieve a high thermal conductivity by such means, the amount of thermally conductive inorganic particles must be increased to an amount close to the closest packing to form a sufficient thermal conduction path. . However, as the blending amount of the inorganic particles is increased, the flexibility of the heat conductive sheet is lost, and as a result, the function of absorbing irregularities and relaxing thermal stress tends to be impaired.

  On the other hand, in the thermally conductive sheet disclosed in Patent Document 2, in addition to the above-mentioned means, a means for magnetically orienting boron nitride powder in a certain direction is adopted, so that fewer thermally conductive inorganic particles There is a possibility that high thermal conductivity can be achieved with a blending amount of. However, there is room for improvement in terms of productivity, cost, energy efficiency, and the like during sheet manufacturing.

  In addition, the thermally conductive sheet disclosed in Patent Document 3 is more advantageous in terms of productivity, cost, energy efficiency, and the like at the time of sheet manufacture than the above-mentioned means, but considerations regarding flexibility are not necessarily taken into account. Not enough. In particular, there is room for improvement due to lack of consideration for slicing a flexible sheet laminate at the time of sheet manufacture and inefficient production methods such as impregnation with a plasticizer later.

The heat conductive sheet disclosed in Patent Document 4 is superior in flexibility and productivity as compared with the means described in Patent Document 3, but the consideration on the strength of the sheet is not sufficient. In particular, the study of the resin composition is not always sufficient, and there is room for improvement.
As described above, various studies have been made for the heat conductive sheet. From the viewpoint of easily and reliably adding characteristics such as flexibility, strength, and stress relaxation to the sheet as well as high heat conductivity. Neither method is satisfactory.

  In view of such circumstances, an object of the present invention is to provide an electrically insulating thermal conductive sheet having additional characteristics such as flexibility and strength while maintaining high thermal conductivity. In addition, a method for easily and reliably manufacturing such a heat conductive sheet, and a heat dissipating device using such a heat conductive sheet, having a high heat dissipating capability and having a low risk of short-circuiting nearby circuits are provided. For the purpose.

The present invention is as follows.
(1) Heat comprising a resin composition comprising non-spherical particles (A), an organic polymer compound (B) having a carboxyl group, a curing agent (C), and an additive (D) having an amino group A conductive sheet,
The heat conductive sheet in which the non-spherical particles (A) are oriented in the major axis direction of the non-spherical particles (A) with respect to the thickness direction of the heat conductive sheet inside the heat conductive sheet.

(2) The heat conductive sheet according to (1), wherein the non-spherical particles (A) are boron nitride particles.
(3) The heat conductive sheet according to (1) or (2), wherein the non-spherical particles (A) are plate-like boron nitride particles.

(4) The heat conductive sheet according to any one of (1) to (3), wherein the organic polymer compound (B) has a glass transition temperature (Tg) of 50 ° C. or lower.
(5) The heat conductive sheet according to any one of (1) to (4), wherein the organic polymer compound (B) is a poly (meth) acrylate polymer compound. .

(6) The heat conduction as described in any one of (1) to (5) above, wherein the organic polymer compound (B) has a carboxyl group of 0.1 to 2.0 mmol / g. Sheet.
(7) The above (characterized in that the amount of the curable reactive group of the curing agent (C) is 0.01 to 3 equivalents relative to the amount of the carboxyl group of the organic polymer compound (B). The heat conductive sheet according to any one of 1) to (6).

(8) The additive (D) is contained in an amount of 0.01 to 10 parts by mass with respect to 100 parts by mass of the resin composition, as described in any one of (1) to (7) above Heat conduction sheet.
(9) The non-spherical particle (A) is a method for producing a heat conductive sheet in which the non-spherical particle (A) is oriented in the major axis direction with respect to the thickness direction of the sheet,
(A) At least the non-spherical particles (A), the organic polymer compound (B) having a carboxyl group, the curing agent (C), and the additive (D) having an amino group are mixed to obtain a resin. Preparing a composition;
(B) using the resin composition, forming a primary sheet in which the non-spherical particles (A) are oriented in a direction substantially parallel to a main surface;
(C-1) a step of laminating the primary sheet to form a molded body having a multilayer structure;
(D) slicing the molded body at an angle of 0 degree to 30 degrees with respect to a normal line extending from the main surface thereof, and a method for producing a heat conductive sheet.

(10) The non-spherical particle (A) is a method for producing a heat conductive sheet in which the non-spherical particle (A) is oriented in the major axis direction with respect to the thickness direction of the sheet,
(A) At least the non-spherical particles (A), the organic polymer compound (B) having a carboxyl group, the curing agent (C), and the additive (D) having an amino group are mixed to obtain a resin. Preparing a composition;
(B) using the resin composition, forming a primary sheet in which the non-spherical particles (A) are oriented in a direction substantially parallel to a main surface;
(C-2) winding the primary sheet around the orientation direction of the non-spherical particles (A) as an axis to form a molded body having a multilayer structure;
(D) slicing the molded body at an angle of 0 degree to 30 degrees with respect to a normal line extending from the main surface thereof, and a method for producing a heat conductive sheet.

(11) The step (9) or (10), wherein the step of forming the primary sheet is performed using at least one forming method selected from the group consisting of rolling, pressing, extrusion, and coating. The manufacturing method of the heat conductive sheet of description.
(12) The method for producing a heat conductive sheet according to the above (9) or (10), wherein the step of forming the primary sheet is performed using at least a forming method of either rolling or pressing. .

(13) The slicing step is performed in a temperature range of Tg + 50 ° C. (temperature higher by 50 ° C. than the glass transition temperature) to Tg−20 ° C. (temperature lower by 20 ° C. than the glass transition temperature) of the organic polymer compound (B). The method for producing a heat conductive sheet according to any one of the above (9) to (12), which is performed.
(14) A heat dissipation device having a structure in which the heat conductive sheet according to any one of (1) to (8) is interposed between a heat generator and a heat radiator.

  The heat conductive sheet of the present invention has both high heat conductivity, high flexibility, and excellent sheet strength, and is electrically insulative. It is possible to achieve efficient heat dissipation from the part. Moreover, it is possible to easily add performance such as flame retardancy as necessary.

Further, according to the method for producing a heat conductive sheet of the present invention, compared with the conventional method, it is advantageous in terms of productivity, cost, energy efficiency and certainty, high heat conductivity, high flexibility, and excellent sheet. It is possible to provide a heat conductive sheet having both strength and strength.
Furthermore, according to the heat dissipating device of the present invention, the possibility of causing a short circuit near the circuit becomes extremely low, and it is possible to realize complete and efficient heat dissipation.

Hereinafter, the present invention will be described in detail.
<Heat conduction sheet>
The heat conductive sheet of the present invention is a resin comprising non-spherical particles (A), an organic polymer compound (B) having a carboxyl group, a curing agent (C), and an additive (D) having an amino group. A heat conductive sheet comprising the composition, wherein the non-spherical particles (A) are oriented in the major axis direction of the non-spherical particles (A) with respect to the thickness direction of the heat conductive sheet inside the heat conductive sheet. It is characterized by.

In the present invention, the use of the non-spherical particles (A) has a sufficient effect on the thermal conductivity of the heat conductive sheet. Specifically, the non-spherical particles are those having a ratio of the major axis direction to the minor axis direction of 1.5 or more as “non-spherical” in the present invention.
The “major axis” is the longest part of the line connecting any two points at the particle end, and the “short axis” is the longest part of the line orthogonal to the major axis. is there.

  In the present invention, it is sufficient that non-spherical particles in this range are contained, and particles outside this range can be added as necessary. Since the higher aspect ratio of the non-spherical particles is more advantageous for orientation, the particle shape is preferably a needle shape or a plate shape. Furthermore, spherical particles can be used as non-spherical particles by pulverization, pulverization, or the like.

In the present invention, “oriented in the major axis direction of the non-spherical particles (A) with respect to the thickness direction of the heat conductive sheet” means that the cross section of the heat conductive sheet is 50 arbitrary particles using a scanning electron microscope (SEM). Means that the average value of the angle of the non-spherical particles to the surface of the heat conductive sheet in the major axis direction (adopting a complementary angle when 90 degrees or more) is in the range of 70 degrees to 90 degrees. To do.
In the present invention, sufficient thermal conductivity cannot be obtained unless the non-spherical particles exhibit the above-described orientation. What is necessary is just to produce with the manufacturing method of the heat conductive sheet of this invention in order to make it show the above orientations. Details will be described later.

  Specific examples of non-spherical particles that can be used in the heat conductive sheet of the present invention include alumina, magnesium oxide, beryllium oxide, aluminum nitride, boron nitride, silicon nitride, and the like. Although not particularly limited, in the present invention, it is preferable to use at least one kind of particles selected from the group consisting of boron nitride and alumina from the viewpoint of low harmfulness to the human body. Further, the shape is preferably plate-like, and plate-like boron nitride particles are particularly preferred as the insulating non-spherical particles.

  The blending amount of the non-spherical particles is not particularly limited, but is preferably in the range of 30 to 80% by volume based on the volume of the resin composition. If the blending amount is less than 30% by volume, the thermal conductivity tends to be low, and if the blending amount exceeds 80% by volume, the cohesive strength of the composition tends to decrease, and the strength of the heat conducting sheet decreases. Probability is high.

In this invention, the compounding quantity (volume%) of the non-spherical particle | grains (A) in the resin composition of a heat conductive sheet is the value calculated | required by following Formula.
Content of non-spherical particles (A) (volume%) = (Aw / Ad) / ((Aw / Ad) + (Bw / Bd) + (Cw / Cd) + (Ew / Ed) ...) × 100
Aw: mass composition (% by mass) of non-spherical particles (A)
Bw: mass composition (mass%) of the organic polymer compound (B)
Cw: mass composition (mass%) of the curing agent (C)
Dw: mass composition (mass%) of additive (D) having an amino group
Ew: mass composition (% by mass) of other optional component (D)
Ad: Specific gravity of non-spherical particles (A) (In the present invention, in the case of boron nitride particles, Ad is calculated as 2.3. In addition, alumina: 3.97, aluminum nitride: 3.26, silicon nitride: 3.2 calculate.)
Bd: Specific gravity of the organic polymer compound (B) (Bd is calculated as 1.2 in the present invention)
Cd: specific gravity of curing agent (C) (in the present invention, Cd is calculated as 1.2)
Dd: specific gravity of the additive (D) having an amino group (in the present invention, Dd is calculated as 1.2)
Ed: Specific gravity of other optional component (D)

When the non-spherical particles in the present invention are plate-like boron nitride particles, the average particle size is preferably more than 10 μm and 60 μm or less. For example, an aggregate-like material can be obtained as non-spherical particles by pulverization, pulverization, or the like. In addition, when the average particle size is outside the range of more than 10 μm and 60 μm or less, it can be adjusted within a specific average particle size range by removing particles that are too large or too small by crushing, sieving, etc. Is possible.
The average particle diameter is a value of D50 when measured by a laser diffraction / scattering method.

In the present invention, specific examples of the plate-like boron nitride particles preferably used as the non-spherical particles (A) are not particularly limited, but “PT-110 (trade name)” (Momentive Performance Materials Japan Joint Made by company, average particle size: 45 μm, ratio of major axis direction to minor axis direction: 20), “HP-1CAW (trade name)” (manufactured by Mizushima Alloy Iron Co., Ltd., average particle size: 16 μm, major axis direction) Ratio of minor axis direction: 13), “PT-110 Plus (trade name)” (Momentive Performance Materials Japan G.K., average particle size 45 μm, ratio of major axis direction to minor axis direction: 20), “HP −1CA (trade name) ”(manufactured by Mizushima Alloy Iron Co., Ltd., average particle diameter 16 μm, ratio of major axis direction to minor axis direction: 13).
Examples of the plate-like aluminum nitride particles include “Toyalnite FLX (trade name)” (manufactured by Toyo Aluminum Co., Ltd., average particle diameter of 16 μm, ratio of major axis direction to minor axis direction: 1.7). It is done.

  The organic polymer compound (B) of the heat conductive sheet of the present invention can be used without particular limitation as long as it has a carboxyl group. Specific examples of the organic polymer compound include a poly (meth) acrylate polymer compound (so-called acrylic rubber) and a polydimethylsiloxane structure mainly composed of butyl acrylate, 2-ethylhexyl acrylate, and the like. Polymer compound having main structure (so-called silicone resin), polymer compound having polyisoprene structure in main structure (so-called isoprene rubber, natural rubber), polymer compound having polychloroprene as main raw material component (polychloroprene, so-called neoprene) Rubber) and polymer compounds having a polybutadiene structure as a main structure (so-called butadiene rubber), etc., and flexible organic polymer compounds generally referred to as “rubber”. Among these, in particular, a poly (meth) acrylic acid ester-based polymer compound containing butyl acrylate or 2-ethylhexyl acrylate as a main raw material component easily obtains high flexibility, chemical stability and It is preferable because it is excellent in workability and relatively inexpensive.

The organic polymer compound preferably has (B) and a glass transition temperature (Tg) of 50 ° C. or lower.
The glass transition temperature (Tg) of the organic polymer compound can be measured with a dynamic viscoelasticity measuring device (DMA). As the dynamic viscoelasticity measuring device (DMA), for example, ARES-2KSTD manufactured by TA Instruments can be used. The measurement conditions are a temperature rising rate: 5 ° C./min and a measurement frequency: 1.0 Hz.

The carboxy content of the organic polymer compound (B) is preferably in the range of 0.1 to 2.0 mmol / g. In this invention, it is preferable to contain the organic polymer compound of this range, and it is also possible to mix and use the organic polymer compound outside this range as necessary. In that case, it is preferable that the carboxyl amount calculated after mixing is in the range of 0.1 to 2.0 mmol / g. When the carboxy amount of the organic polymer compound is 0.1 mmol / g or less, the strength of the heat conductive sheet tends to be insufficient, and when it is 2.0 mmol / g or more, the flexibility tends to be insufficient. .
The amount of carboxyl of the organic polymer compound (B) is determined by titrating an organic polymer compound solution obtained by dissolving the organic polymer compound in an appropriate solvent such as ethyl acetate or methyl ethyl ketone with an alcoholic potassium hydroxide solution. Calculate from titration volume and resin mass.

  The organic polymer compound (B) preferably has a weight average molecular weight (Mw) of 10,000 to 1,000,000. The weight average molecular weight can be measured by gel permeation chromatography using a standard polystyrene calibration curve.

  Although not particularly limited, examples of the organic polymer compound (B) that can be suitably used in the present invention include an acrylic ester copolymer resin “HTR-811A modified 3DR (trade name) manufactured by Nagase ChemteX Corporation”. (Butyl acrylate / ethyl acrylate / acrylic acid copolymer, carboxy content 0.69 mmol / g, Mw: 550,000, Tg: −41 ° C., solid), acrylate ester manufactured by Nagase ChemteX Corporation Polymerization resin “HTR-280DR (trade name)” (butyl acrylate / acrylonitrile / acrylic acid copolymer, carboxy content 1.07 mmol / g, Mw: 900,000, Tg: −37 ° C., 30 mass% toluene / ethyl acetate = 1: 1 solution) and the like.

  The blending amount of the organic polymer compound (B) is preferably 10 to 40% by volume in the resin composition. There exists a tendency for sufficient sheet | seat strength to be acquired as it is 10 volume% or more. If it is 40 volume% or less, a sufficient amount of non-spherical particles (A) can be contained, and sufficient thermal conductivity tends to be obtained.

  Although the hardening | curing agent (C) used for this invention is not specifically limited, Epoxy is preferable from viewpoints, such as the reactivity with a carboxyl group. Examples of the curing agent (C) include bisphenol-type epoxy, biphenyl-type epoxy, stilbene-type epoxy, and naphthalene-type epoxy, and preferably have a glycidyl group. Examples of the curing agent (C) having the above characteristics include bisphenol F type epoxy (trade name: YDF-8170, bifunctional, epoxy equivalent: 156 g / eq.) Manufactured by Toto Kasei Co., Ltd. (trade name: EX -211, manufactured by Nagase ChemteX Corporation, bifunctional, epoxy equivalent: 138 g / eq.), Etc. are available.

  Content of the said hardening | curing agent (C) is 0.01-3 equivalent with respect to the quantity of the carboxyl group in an organic polymer compound (B), Preferably it is 0.1-2 equivalent, More preferably, 0.2- 1 equivalent. When the content of the curing agent (C) is 0.01 equivalent or more, the film strength and the compression recovery property are excellent, and when it is 3 equivalent or less, the flexibility tends to be excellent.

The additive (D) having an amino group used in the present invention is not particularly limited as long as it contains an amino group. As the additive (D) having an amino group, for example, a salt of a polymer having an amino group (trade name: DISPERBYK-106: manufactured by Big Chemie Japan Co., Ltd.), an amine-based acrylic copolymer (trade name: DISPERBYK). -116: Big Chemie Japan Co., Ltd.), amine block copolymer (trade name: DISPERBYK-2155: Big Chemie Japan Co., Ltd.), amine series silane coupling agent (trade name: KBE-603, KBE-903) : Manufactured by Shin-Etsu Chemical Co., Ltd., trade name: Z-6011: manufactured by Toray Dow Corning Co., Ltd.), etc., but there is no particular limitation as long as it has an amino group.
Content of the said additive (D) which has an amino group is 0.01-10 mass parts with respect to 100 mass parts of said resin compositions, Preferably it is 0.1-8 mass parts, More preferably, it is 0.5. -5 parts by mass.
When the content of the additive (D) having an amino group is 0.01 parts by mass or more, the film strength and the compression recovery property are excellent, and when it is 10 parts by mass or less, the flexibility is excellent.
Various other additives can be added to the resin composition constituting the heat conductive sheet of the present invention as necessary.

In the preferable form of this invention, it is preferable to use a flame retardant for the purpose of improving the flame retardance of a heat conductive sheet. Although it does not specifically limit, the heat conductive sheet comprised from the resin composition containing a phosphate ester type flame retardant is advantageous not only in terms of flame retardancy and flexibility, but also in terms of productivity and cost. .
The content of the flame retardant is preferably in the range of 5 to 50% by volume in the resin composition, and more preferably in the range of 10 to 40% by volume. If the content of the flame retardant is 5% by volume or more, sufficient flame retardancy can be obtained in the heat conductive sheet. If it is 50 volume% or less, there exists a tendency which can prevent the intensity | strength of a sheet | seat falling.

  In addition, to the resin composition constituting the heat conductive sheet of the present invention, if necessary, a toughness improving agent such as urethane acrylate, a silane coupling agent, a titanium coupling agent, and an adhesive strength improving agent such as an acid anhydride, It is also possible to add various additives such as wetting improvers such as nonionic surfactants and fluorine surfactants, antifoaming agents such as silicone oil, and ion trapping agents such as inorganic ion exchangers.

  The shape of the heat conductive sheet of the present invention can be formed into a shape corresponding to various applications to which the heat conductive sheet is applied, within the range in which the desired orientation of the non-spherical particles described above can be achieved. Although it does not specifically limit, in this invention, it is preferable to form a heat conductive sheet from the molded object which has a multilayer structure. By forming the heat conductive sheet from a molded article having a multilayer structure, it is advantageous for the orientation of the non-spherical particles, and the heat conduction efficiency can be improved by increasing the density of the non-spherical particles. The manufacturing method of the heat conductive sheet of this invention is mentioned later.

Since the heat conductive sheet of this invention comprised from the above-mentioned resin composition contains the organic polymer compound (B) whose glass transition temperature (Tg) is 50 degrees C or less, many have adhesive force. Therefore, in the present invention, it is preferable to protect the adhesive surface prior to the use of the heat conductive sheet. Protection of an adhesive surface is implemented by providing a protective film on the adhesive surface, for example, when forming a heat conductive sheet using the above-mentioned resin composition.
Examples of the material for the protective film include resins such as polyethylene, polyester, polypropylene, polyethylene terephthalate, polyimide, polyetherimide, polyether naphthalate, and methylpentene film, and metals such as coated paper, coated cloth, and aluminum. These protective films may be a multilayer film composed of two or more kinds of films, and a film whose surface is treated with a release agent such as silicone or silica is preferably used.

<The manufacturing method of a heat conductive sheet>
The method for producing the heat conductive sheet is also within the scope of the present invention.
The method for producing a heat conductive sheet of the present invention in which the non-spherical particles (A) are oriented in the major axis direction of the non-spherical particles (A) with respect to the thickness direction of the sheet,
(A) At least the non-spherical particles (A), an organic polymer compound (B) having a carboxyl group of 0.1 to 2.0 mmol / g, a curing agent (C), and an additive having an amino group (D) and a step of preparing a resin composition;
(B) using the resin composition, forming a primary sheet in which the non-spherical particles (A) are oriented in a direction substantially parallel to a main surface;
(C-1) a step of laminating the primary sheet to form a molded body having a multilayer structure;
(D) slicing the molded body at an angle of 0 degree to 30 degrees with respect to a normal line extending from the main surface.
Instead of the step (c-1), (c-2) the primary sheet may be wound around the orientation direction of the non-spherical particles to form a molded body having a multilayer structure. is there.

Hereinafter, each step will be described.
In the step (a), the resin composition constituting the heat conductive sheet is prepared by any method as long as predetermined non-spherical particles can be uniformly mixed in the resin composition. Also good. Although it is not particularly limited, for example, an organic polymer compound is previously dissolved in a solvent to form a solution, and other non-spherical particles, a curing agent, an additive having an amino group and a flame retardant are added to the solution. It is possible to prepare a resin composition by a method of adding an agent, mixing and stirring and then drying, or a method of mixing each component using roll kneading, kneader, brabender, or extruder. .

  The solvent used is not particularly limited as long as it can be removed by drying after mixing and stirring. For example, acetone, methyl ethyl ketone, methyl butyl ketone, hexane, cyclohexane, ethyl acetate, butyl acetate, benzene, toluene, xylene Etc.

  In the step of forming the primary sheet (b), a conventional film forming technique can be applied, but at least one forming method selected from the group consisting of rolling, pressing, extrusion, and coating is used. It is preferable to carry out using. By selecting at least one of rolling and pressing as the forming method, the non-spherical particles can be more reliably oriented in a direction substantially parallel to the main surface. Moreover, when those methods are selected, non-spherical particles tend to come into contact with each other by applying pressure during the primary sheet molding, and high thermal conductivity tends to be easily achieved. In addition, the thinner one is preferable from the viewpoint of thermal conductivity. When the thickness of the primary sheet is increased, the orientation of the particles becomes insufficient, and the thermal conductivity of the finally obtained thermal conductive sheet tends to deteriorate.

  The state in which the non-spherical particles are oriented in a direction substantially parallel to the main surface of the primary sheet refers to a state in which the non-spherical particles are oriented so as to lie on the main surface of the primary sheet. The orientation of the non-spherical particles in the primary sheet surface is controlled by adjusting the direction in which the resin composition flows when the resin composition is molded. That is, the direction of the non-spherical particles is controlled by adjusting the direction in which the resin composition is passed through a rolling roll, the direction in which the composition is pressed, the direction in which the composition is extruded, and the direction in which the composition is applied. Since the non-spherical particles are basically particles having anisotropy, the orientation of the non-spherical particles is usually aligned by rolling molding, press molding, extrusion molding or coating the resin composition. The

  The confirmation of “the state in which the non-spherical particles are oriented in a direction substantially parallel to the main surface of the primary sheet” is the same as the confirmation method of “the orientation in the major axis direction with respect to the thickness direction of the heat conduction sheet” described above. The cross section of the sheet is observed by observing 50 arbitrary particles using SEM. Specifically, the cross section of the primary sheet is observed using an SEM, and for any 50 particles, the angle of the non-spherical particles in the major axis direction with respect to the primary sheet surface (a complementary angle is adopted when 90 degrees or more) Confirm that the average value of is in the range of 0 to 20 degrees.

  The step of forming the molded body having the multilayer structure of (c-1) or (c-2) can be performed by laminating the primary sheet obtained in the previous step. The form of lamination is not particularly limited, and is not limited to a form in which a plurality of independent primary sheets are sequentially stacked, for example, and may be a form in which a single primary sheet is folded without cutting its end. . As another form of lamination, it is also possible to wind a single primary sheet to form a molded body. The form of winding is not limited to the shape of the molded body being cylindrical, but may be another shape such as a rectangular tube. The shape of the molded body may be any shape as long as there is no inconvenience when slicing the molded body at an angle of 0 to 30 degrees with respect to the normal line from the main surface in the subsequent step (d). Good. For example, the shape of each primary sheet is formed into a circular shape, and a cylindrical shaped body is produced by laminating them, and the subsequent slicing in the step (d) is performed by a method such as “wig removal”. Is also possible.

  In the step (c-1) or (c-2), the pressure at the time of lamination and the pulling force at the time of winding are performed later. It is desirable to adjust so that the orientation is weak enough not to collapse and is strong enough that the primary sheets in the molded body are appropriately bonded to each other. Usually, it is possible to obtain sufficient adhesion between the primary sheets by adjusting the pressure and tensile force when forming the molded body. However, when the adhesive force between the primary sheets is insufficient, lamination or winding may be performed after thinly applying a solvent or an adhesive to the surface of the primary sheet.

The step of slicing the shaped body of (d) above is to slice the shaped body at an angle of 0 degree to 30 degrees with respect to the normal line coming out from the main surface so that the heat conductive sheet has a predetermined thickness. Implemented by: Although the cutting tool which can be used at the time of a slice is not specifically limited, It is preferable to use a slicer, a cannula, etc. provided with a sharp blade. By using a cutting tool equipped with a sharp blade, it is possible to easily produce a thin heat conduction sheet in which the orientation of non-spherical particles near the surface of the heat conduction sheet obtained after slicing is not disturbed. .
When the slicing angle is 30 degrees or less, the thermal conductivity of the obtained thermal conductive sheet is good. When the molded body is a laminated body, it may be sliced (within the above angle range) so as to be perpendicular or substantially perpendicular to the lamination direction of the primary sheet. When the molded body is a wound body, it may be sliced (within the above angle range) so as to be perpendicular or almost perpendicular to the winding axis. As described above, in the case of a columnar molded body in which circular primary sheets are laminated, they may be sliced like a wig within the above angle range.

  (D) The slicing step is performed at a temperature (Tg + 50 ° C.) higher than the glass transition temperature (Tg) of the organic polymer compound (B) constituting the resin composition by 20 ° C. (Tg). It is preferable to carry out within the range of “−20 ° C.)”. When the temperature at the time of slicing is Tg + 50 ° C. or lower, not only does the molded body become flexible and it becomes difficult to perform slicing, but also the orientation of non-spherical particles in the heat conductive sheet is prevented from being disturbed. On the other hand, when the temperature at the time of slicing is Tg−20 ° C. or higher, the molded body becomes hard and brittle, and it is difficult to perform slicing, and it is easy to avoid the thermal conductive sheet from cracking immediately after slicing. A more preferable temperature for slicing is a temperature range of Tg + 40 ° C. to Tg−10 ° C.

  In addition, as preferable thickness of a heat conductive sheet, it is 200 times or less (preferably 100 times or less) of the average particle diameter more than the average particle diameter of the nonspherical particle contained. When the average particle size is greater than or equal to the average particle size, it is considered that non-spherical particles can be prevented from falling off the heat conductive sheet. When the average particle size is 200 times or less, the number of passes through the non-spherical particles is reduced, and the thermal conductivity is improved.

<Heat dissipation device>
The present invention also includes a heat dissipation device. The heat radiating device of the present invention has a structure in which the heat conductive sheet of the present invention is interposed between a heat generating body and a heat radiating body.
The heating element that can be used in the heat dissipation device of the present invention has at least a surface temperature not exceeding 200 ° C, and the temperature at which the heat conductive sheet of the present invention can be suitably used is in the range of -10 ° C to 120 ° C. is there. There is a high possibility that the surface of the heating element exceeds 200 ° C., for example, in the vicinity of the nozzle of a jet engine, around the inside of a kiln pot, around the inside of a blast furnace, around the inside of a nuclear reactor, outer space shell, etc. Since there is a high possibility that the organic polymer compound in the sheet is decomposed, it tends to be unsuitable. Examples of the heating element suitable for the heat dissipation device of the present invention include a semiconductor package, a display, an LED, and an electric lamp.

  On the other hand, the heat radiator that can be used in the heat radiating device of the present invention is not particularly limited, and may be a typical one that is applied to the heat radiating device. For example, a heat sink using aluminum or copper fins or plates, an aluminum or copper block connected to a heat pipe, an aluminum or copper block in which cooling liquid is circulated by a pump, a Peltier element and this Examples include aluminum and copper blocks.

Instead of aluminum or copper, materials with a thermal conductivity of 10 W / mK or more, such as metals such as silver, iron, indium, graphite, diamond, aluminum nitride, boron nitride, silicon nitride, silicon carbide, aluminum oxide, etc. Those utilized are also preferred.
The heat dissipating device of the present invention is established by installing the heat conductive sheet of the present invention between the above-described heat generating body and the heat dissipating body and fixing each surface in contact. The heat conductive sheet is not particularly limited as long as it can be fixed in a state where the contact surfaces are sufficiently adhered, and any method may be used. However, from the viewpoint of maintaining sufficient contact between the contact surfaces, a method in which the pressing force is maintained is preferable. For example, the method of screwing using a spring and the method of inserting | pinching using a clip are mentioned. According to the heat dissipating device of the present invention, high heat dissipating efficiency can be achieved, and there is little risk of shorting nearby circuits.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples.
In each example, the thermal conductivity and tensile strength were determined by the following methods.

(Measurement of thermal conductivity)
The heat conductive sheet to be measured was cut into a size of 1 cm × 1 cm with a cutter, and the cut piece was placed so that one surface was in contact with the transistor (2SC2233) and the other surface was in contact with the aluminum heat dissipation block, thereby preparing a test sample. . Next, while pressing the transistor, current is passed through the test sample to measure the temperature of the transistor (T1, unit ° C) and the temperature of the heat dissipation block (T2, unit ° C). From the measured value and the applied power (W, unit W), The thermal resistance (X, unit ° C / W) was measured according to the following formula.

  From the obtained thermal resistance (X), the thickness of the cut piece (d, unit μm), and the correction coefficient C based on a known sample of thermal conductivity, the thermal conductivity (Tc, unit W / mK) was ) Was estimated.

(Measurement of tensile strength)
The heat conductive sheet was cut out so as to be 5 cm in a direction perpendicular to the normal line coming out from the primary sheet surface and 1 cm in a direction parallel to the normal line coming out from the primary sheet surface, and a tensile tester (R & A Co., Ltd.) Product, product name: RTM-100 type Tensilon), pinch 1 cm from both ends so that the direction perpendicular to the normal line coming out from the primary sheet surface is 3 cm wide, and the primary temperature at 20-30 ° C. The film was pulled at a tensile speed of 5 mm / min in a direction perpendicular to the normal line coming out of the sheet surface, and the breaking strength (tensile strength) of the heat conductive sheet was measured.

Example 1
(A) Plate-like boron nitride particles “PT-110 (trade name)” as non-spherical particles (Momentive Performance Materials Japan G.K., average particle size 45 μm, ratio of major axis direction to minor axis direction: 20) 13.5 g and (B) an acrylic acid ester copolymer resin “HTR-811A modified 3DR (trade name)” as an organic polymer compound (manufactured by Nagase ChemteX Corporation, butyl acrylate / ethyl acrylate / acrylic acid co Polymer, carboxy content 0.69 mmol / g, Mw: 550,000, Tg: −41 ° C., solid) 3.54 g, and (C) bisphenol F type epoxy (manufactured by Tohto Kasei Co., Ltd., trade name) YDF-8170C, bifunctional, epoxy equivalent: 156 g / eq.) 0.07 g and (D) a salt of a polymer having an amino group as an additive having an amino group 2. Product name: DISPERBYK-106, manufactured by Big Chemie Japan Co., Ltd.) 0.27 g, and (E) phosphate ester flame retardant “CR-741 (trade name)” (manufactured by Daihachi Chemical Industry Co., Ltd.) A resin composition was prepared by heating and kneading 17 g to 120 ° C.

  The blending ratio of the composition calculated from the specific gravity of the raw materials was (A) boron nitride particles 50.0% by volume, (B) acrylic acid ester copolymer resin 25.1% by volume, (C) bisphenol F type epoxy 0.3%. 5% by volume, (D) 1.9% by volume of a polymer salt having an amino group, and (E) 22.5% by volume of a phosphate ester flame retardant.

1 g of the previously prepared resin composition is sandwiched between mold-released PET films and pressed for 10 seconds under a tool pressure of 10 MPa and a tool temperature of 120 ° C. using a press having a tool surface of 5 cm × 10 cm. Thus, a primary sheet having a thickness of 0.3 mm was obtained. By repeating this operation, a large number of primary sheets were produced.
In the primary sheet, confirmation of “the state in which the non-spherical particles (A) were oriented in a direction substantially parallel to the main surface of the primary sheet” was performed as follows.
The cross section of the obtained primary sheet was observed using a scanning electron microscope (SEM), and the angle of the nonspherical particles with respect to the primary sheet surface in the major axis direction was measured from the direction seen for any 50 nonspherical particles. The average value was 7 degrees, and it was confirmed that the major axis direction of the non-spherical particles was oriented in a direction substantially parallel to the main surface of the primary sheet.

  Each primary sheet thus obtained was cut into a size of 2 cm × 2 cm with a cutter, and 37 sheets thereof were laminated, and lightly pressed by hand to bond the layers of each primary sheet to obtain a molded body having a thickness of 1.1 cm. It was. After cooling this molded body with dry ice, at a temperature of −10 ° C., a 1.1 cm × 2 cm laminated section was shaved with a plane (sliced at an angle of 5 degrees with respect to the normal line coming out from the primary sheet surface), and the size was A heat conductive sheet of Example 1 having a size of 1.1 cm × 2 cm × 0.51 mm was obtained.

The cross section of the obtained heat conductive sheet was observed using an SEM (scanning electron microscope), and the surface of the heat conductive sheet in the major axis direction of the non-spherical particles from the direction seen for any 50 plate-like boron nitride particles The angle with respect to was measured, and the average value was found to be 84 degrees, and it was confirmed that the major axis direction of the non-spherical particles was oriented in the thickness direction of the heat conductive sheet.
The obtained heat conductive sheet had a heat conductivity of 11 W / mK and a tensile strength of 0.63 MPa. The results are shown in Table 1.

(Example 2)
(D) Thermal conductivity of Example 2 under the same conditions as in Example 1 except that the amine-based acrylic copolymer “DISPERBYK-116” (trade name: manufactured by Big Chemie Japan Co., Ltd.) was used as the additive. A sheet was obtained.
In addition, the cross section of the primary sheet obtained in Example 2 was observed using an SEM (scanning electron microscope), and the length of the plate-like boron nitride particles from the direction in which any 50 plate-like boron nitride particles were seen. The angle with respect to the surface of the primary sheet in the axial direction was measured, and the average value was found to be 4 degrees. The major axis direction of the plate-like boron nitride particles was oriented in a direction substantially parallel to the main surface of the primary sheet. Was recognized.

Moreover, the cross section of the obtained heat conductive sheet is observed using a SEM (scanning electron microscope), and the direction of the long axis direction of the plate-like boron nitride particles from the direction seen for any 50 plate-like boron nitride particles. When the angle with respect to the surface of the heat conductive sheet was measured and the average value was obtained, it was 87 degrees, and it was confirmed that the major axis direction of the plate-like boron nitride particles was oriented in the thickness direction of the heat conductive sheet.
The obtained heat conductive sheet showed good values of thermal conductivity 10 W / mK and tensile strength 1.01 MPa. The results are shown in Table 1.

(Example 3)
(D) The heat conductive sheet of Example 3 was used under the same conditions as in Example 1 except that the amine block copolymer “DISPERBYK-2155” (trade name: manufactured by Big Chemie Japan Co., Ltd.) was used as the additive. Obtained.

  In addition, the cross section of the primary sheet obtained in Example 3 was observed using a SEM (scanning electron microscope), and the length of the plate-like boron nitride particles from the direction in which any 50 plate-like boron nitride particles were seen. The angle with respect to the surface of the primary sheet in the axial direction was measured, and the average value was found to be 10 degrees. The major axis direction of the plate-like boron nitride particles was oriented in a direction substantially parallel to the main surface of the primary sheet. Was recognized.

Moreover, the cross section of the obtained heat conductive sheet is observed using a SEM (scanning electron microscope), and the direction of the long axis direction of the plate-like boron nitride particles from the direction seen for any 50 plate-like boron nitride particles. The angle with respect to the surface of the heat conductive sheet was measured, and the average value was found to be 84 degrees. It was confirmed that the major axis direction of the plate-like boron nitride particles was oriented in the thickness direction of the heat conductive sheet.
The obtained heat conductive sheet had a heat conductivity of 11 W / mK and a tensile strength of 0.59 MPa. The results are shown in Table 1.

(Comparative Example 1)
(A) Except for using spherical boron nitride particles (trade name: FS-3) (manufactured by Mizushima Alloy Iron Co., Ltd., average particle size: 50 μm, ratio of superaxial direction to short axis direction: 1) Under the same conditions as in Example 1, a heat conductive sheet of Comparative Example 1 was obtained.

In addition, although the cross section of the primary sheet obtained in Comparative Example 1 was observed using an SEM (scanning electron microscope), it was observed from the direction in which any 50 spherical boron nitride particles were seen. The orientation with respect to the main surface of the primary sheet was not recognized.
Moreover, although the cross section of the obtained heat conductive sheet was observed using SEM (scanning electron microscope), the orientation with respect to the thickness direction of a heat conductive sheet was recognized from the direction seen about arbitrary 50 spherical boron nitride particles. I couldn't.

  The tensile strength of the obtained heat conductive sheet was as good as 0.51 MPa, but the heat conductivity was as low as 5 W / mK. The results are shown in Table 2.

(Comparative Example 2)
(A) Plate-like boron nitride powder 13.1 g (60.0% by volume), (B) Acrylate ester copolymer resin “HTR-811DR (trade name)” (butyl acrylate / ethyl acrylate / 2-hydroxy Ethyl methacrylate copolymer, carboxy amount 0 mmol / g, Mw: 420,000, Tg: −43 ° C., solid) 2.56 g (22.5% by volume), and (D) 0.27 g of DISPERBYK-106 as an additive And (E) The heat conductive sheet of the comparative example 2 was obtained on the conditions similar to Example 1 except having used it in the quantity of 1.99 g (17.5 volume%) of the phosphate ester type flame retardant.

  The cross section of the primary sheet obtained in Comparative Example 2 was observed using an SEM (scanning electron microscope), and the length of the plate-like boron nitride particles from the direction in which any 50 plate-like boron nitride particles were seen. The angle with respect to the surface of the primary sheet in the axial direction was measured and the average value was determined to be 9 degrees. The major axis direction of the plate-like boron nitride particles was oriented in a direction substantially parallel to the main surface of the primary sheet. Was recognized.

  Moreover, the cross section of the obtained heat conductive sheet is observed using a SEM (scanning electron microscope), and the direction of the long axis direction of the plate-like boron nitride particles from the direction seen for any 50 plate-like boron nitride particles. The angle with respect to the surface of the heat conductive sheet was measured and the average value was found to be 82 degrees, and it was confirmed that the major axis direction of the plate-like boron nitride particles was oriented in the thickness direction of the heat conductive sheet.

  The thermal conductivity of the obtained thermal conductive sheet was as good as 18 W / mK, but the tensile strength was as low as 0.03 MPa. The results are shown in Table 2.

(Comparative Example 3)
(B) Acrylic ester copolymer resin “HTR-811A modified 3DR (trade name)” (manufactured by Nagase ChemteX Corporation, butyl acrylate / ethyl acrylate / acrylic acid copolymer, carboxy content 0.69 mmol / g , Mw: 550,000, Tg: −41 ° C., solid) was used under the same conditions as in Comparative Example 2 to obtain a heat conductive sheet of Comparative Example 3.

  The cross section of the primary sheet obtained in Comparative Example 3 was observed using an SEM (scanning electron microscope), and the length of the plate-like boron nitride particles from the direction in which any 50 plate-like boron nitride particles were seen. The angle with respect to the primary sheet surface in the axial direction was measured, and the average value was found to be 3 degrees. The major axis direction of the plate-like boron nitride particles was oriented in a direction substantially parallel to the main surface of the primary sheet. Was recognized.

  Moreover, the cross section of the obtained heat conductive sheet is observed using a SEM (scanning electron microscope), and the direction of the long axis direction of the plate-like boron nitride particles from the direction seen for any 50 plate-like boron nitride particles. When the angle with respect to the surface of the heat conductive sheet was measured and the average value was obtained, it was 87 degrees, and it was confirmed that the major axis direction of the plate-like boron nitride particles was oriented in the thickness direction of the heat conductive sheet.

  The thermal conductivity of the obtained thermal conductive sheet was as good as 12 W / mK, but the tensile strength was as low as 0.13 MPa. The results are shown in Table 2.

(Comparative Example 4)
(D) The heat conductive sheet of the comparative example 4 was obtained on the conditions similar to Example 1 except not using DISPERBYK-106 for an additive.

  The cross section of the primary sheet obtained in Comparative Example 4 was observed using an SEM (scanning electron microscope), and the length of the plate-like boron nitride particles from the direction in which any 50 plate-like boron nitride particles were seen. The angle with respect to the surface of the primary sheet in the axial direction was measured, and the average value was found to be 5 degrees. The major axis direction of the plate-like boron nitride particles was oriented in a direction substantially parallel to the main surface of the primary sheet. Was recognized.

Moreover, the cross section of the obtained heat conductive sheet is observed using a SEM (scanning electron microscope), and the direction of the long axis direction of the plate-like boron nitride particles from the direction seen for any 50 plate-like boron nitride particles. The angle with respect to the surface of the heat conductive sheet was measured, and the average value was found to be 86 degrees. It was confirmed that the major axis direction of the plate-like boron nitride particles was oriented in the thickness direction of the heat conductive sheet.
The thermal conductivity of the obtained thermal conductive sheet was as good as 10 W / mK, but the tensile strength was as low as 0.28 MPa. The results are shown in Table 2.

(Comparative Example 5)
(D) The same conditions as in Example 1 except that a phosphate acrylic copolymer “DISPERBYK-111” (trade name: manufactured by Big Chemie Japan Co., Ltd.) having no amino group as an additive was used. Thus, a heat conductive sheet of Comparative Example 5 was obtained.

  Note that the cross section of the primary sheet obtained in Comparative Example 5 was observed using a SEM (scanning electron microscope), and the length of the plate-like boron nitride particles from the direction in which any 50 plate-like boron nitride particles were seen. The angle with respect to the surface of the primary sheet in the axial direction was measured, and the average value was found to be 4 degrees. The major axis direction of the plate-like boron nitride particles was oriented in a direction substantially parallel to the main surface of the primary sheet. Was recognized.

Moreover, the cross section of the obtained heat conductive sheet is observed using a SEM (scanning electron microscope), and the direction of the long axis direction of the plate-like boron nitride particles from the direction seen for any 50 plate-like boron nitride particles. The angle with respect to the surface of the heat conductive sheet was measured, and the average value was found to be 84 degrees. It was confirmed that the major axis direction of the plate-like boron nitride particles was oriented in the thickness direction of the heat conductive sheet.
The thermal conductivity of the obtained thermal conductive sheet was as good as 12 W / mK, but the tensile strength was as low as 0.16 MPa. The results are shown in Table 2.

  According to the present invention, it is possible to provide a heat conductive sheet that has both high thermal conductivity, high flexibility, and excellent sheet strength and is electrically insulating.

Claims (13)

A heat conductive sheet comprising a resin composition comprising non-spherical particles (A), an organic polymer compound (B) having a carboxyl group, a curing agent (C), and an additive (D) having an amino group. There,
The non-spherical particles (A) are oriented in the major axis direction of the non-spherical particles (A) with respect to the thickness direction of the heat conductive sheet inside the heat conductive sheet ,
The non-spherical particles (A) include boron nitride particles,
The heat conductive sheet containing at least one selected from the group consisting of a salt of a polymer having an amino group, an amine acrylic copolymer, an amine block copolymer, and an amine silane coupling agent . The heat conductive sheet according to claim 1 , wherein the non-spherical particles (A) include plate-like boron nitride particles. The heat conductive sheet according to claim 1 or 2 , wherein the organic polymer compound (B) includes one having a glass transition temperature (Tg) of 50 ° C or lower. The organic polymer compound (B) is a poly (meth) thermally conductive sheet according to any one of claims 1 to 3, characterized in that it comprises an acrylic ester-based polymer compound. The said high molecular compound (B) contains what has a carboxyl group of 0.1-2.0 mmol / g, The heat conductive sheet as described in any one of Claims 1-4 characterized by the above-mentioned. 0. The curing agent (C) is, relative to the amount of the carboxyl groups of the organic polymer compound (B). 01-3 thermally conductive sheet according to any one of claims 1 to 5, wherein Rukoto that having a equivalent weight of the curable reactive group. The heat conductive sheet according to any one of claims 1 to 6 , wherein the additive (D) is contained in an amount of 0.01 to 10 parts by mass with respect to 100 parts by mass of the resin composition. A non- spherical particle (A) is a method for producing a heat conductive sheet in which the non-spherical particle (A) is oriented in the major axis direction with respect to the thickness direction of the sheet,
(A) At least the non-spherical particles (A), the organic polymer compound (B) having a carboxyl group, the curing agent (C), and the additive (D) having an amino group are mixed to obtain a resin. Preparing a composition;
(B) using the resin composition, forming a primary sheet in which the non-spherical particles (A) are oriented in a direction substantially parallel to a main surface;
(C-1) a step of laminating the primary sheets to form a molded body having a multilayer structure;
(D) the molded body have a, and slicing at an angle of 0 degrees to 30 degrees with respect to the normal line extending from the main serving surface,
The non-spherical particles (A) include boron nitride particles,
Production of a heat conductive sheet, wherein the additive (D) contains at least one selected from the group consisting of a salt of a polymer having an amino group, an amine-based acrylic copolymer, an amine-based block copolymer, and an amine-based silane coupling agent. Method. A non- spherical particle (A) is a method for producing a heat conductive sheet in which the non-spherical particle (A) is oriented in the major axis direction with respect to the thickness direction of the sheet,
(A) At least the non-spherical particles (A), the organic polymer compound (B) having a carboxyl group, the curing agent (C), and the additive (D) having an amino group are mixed to obtain a resin. Preparing a composition;
(B) using the resin composition, forming a primary sheet in which the non-spherical particles (A) are oriented in a direction substantially parallel to a main surface;
(C-2) winding the primary sheet around the orientation direction of the non-spherical particles (A) as an axis to form a molded body having a multilayer structure;
(D) the molded body have a, and slicing at an angle of 0 degrees to 30 degrees with respect to the normal line extending from the main serving surface,
The non-spherical particles (A) include boron nitride particles,
Production of a heat conductive sheet, wherein the additive (D) contains at least one selected from the group consisting of a salt of a polymer having an amino group, an amine-based acrylic copolymer, an amine-based block copolymer, and an amine-based silane coupling agent. Method. The heat conduction according to claim 8 or 9 , wherein the step of forming the primary sheet is performed using at least one forming method selected from the group consisting of rolling, pressing, extrusion, and coating. Sheet manufacturing method. The method for producing a heat conductive sheet according to claim 8 or 9 , wherein the step of forming the primary sheet is performed using at least a forming method of either rolling or pressing. The slicing step is performed in a temperature range of Tg + 50 ° C. (temperature higher by 50 ° C. than the glass transition temperature) to Tg−20 ° C. (temperature lower by 20 ° C. than the glass transition temperature) of the organic polymer compound (B). The manufacturing method of the heat conductive sheet as described in any one of Claims 8-11 characterized by the above-mentioned. A heat dissipating device having a heat generating element, a heat dissipating element, and a heat conductive sheet interposed between the heat generating element and the heat dissipating element ,
Heat dissipation device wherein thermally conductive sheet, characterized in that it is a thermally conductive sheet according to any one of claims 1-7.