JP2015189884A - Thermosetting resin composition, resin sheet, prepreg and laminate sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition high in heat-conductivity and excellent in insulation properties at high temperature, a resin sheet, a prepreg and a laminate sheet.SOLUTION: There is provided a thermosetting resin composition containing: a polyfunctional epoxy resin monomer; a polyfunctional amine compound; an inorganic filler (A) which is an aggregate of primary particles and has an average particle diameter d1 of 10 μm to 70 μm; and an inorganic filler (B) containing an inorganic filler(b) having an average particle diameter d3 of particle unit of 1 μm or more and less than 10 μm and an inorganic filler (c) having an average particle diameter d4 of 0.1 μm or more and less than 1 μm. A volume ratio of the (b) : the (c) is 90:10 to 70:30. A percentage content of the (A) to a total solid content is 10 to 55 vol.%, and a percentage content of (B) to the total solid content is 10 to 55 vol.%. The total percentage content of the (A) and the (B) is 30 to 80 vol.%.

Description

  The present invention relates to a thermosetting resin composition, a resin sheet, a prepreg, and a laminate using the thermosetting resin composition.

  A wiring board to be mounted on an electronic device is required to have fine wiring and high-density packaging technology associated with the reduction in the thickness and size of the electronic device, and also has high heat dissipation characteristics to cope with heat generation. In particular, in an electronic circuit or the like that uses a large current for various controls and operations, heat generation due to resistance of the conductive circuit or heat generation from the power element is very large, and the heat dissipation characteristics of the wiring board may be high. It has been demanded.

  Under such circumstances, in order to improve the thermal conductivity of the insulating layer of the wiring board, adding an inorganic filler to the thermosetting resin is widely performed. For example, Patent Document 1 discloses a heat-resistant adhesive containing two types of spherical alumina having different average particle diameters in a thermosetting resin. This heat-resistant adhesive can fill a large amount of alumina into the adhesive by blending coarse particles with a large average particle size and fine particles with a small average particle size at a specific ratio, and the heat of the adhesive It improves the conductivity.

  The insulation with respect to the temperature of the substrate is also an important factor. As electronic devices become lighter and thinner, the circuit density increases, and when the heat generation temperature rises due to chip miniaturization, the temperature inside the case also rises and the temperature of the insulating member rises. In general, organic substances increase in molecular motion when the temperature rises, polarization occurs when there are polar molecules or functional groups, and the movement of impurities becomes active when impurities are included. Decreases with increasing temperature.

  Although there are relatively few patent documents describing insulation properties at high temperatures, Patent Document 2 describes an improvement in volume resistivity by the combined use of bisphenol F-type epoxy and acid anhydride.

  Since the temperature of the chip can be expected to rise in the future, it is important to maintain the insulating properties of the resin at high temperatures.

JP 2004-217861 A JP 2001-172495 A

  However, since the adhesive of Patent Document 1 deteriorates the flowability of the resin when the filling rate of the inorganic filler is increased, it is used as an interlayer adhesive when a wiring board or the like is multilayered by using this as a prepreg or a resin sheet. When it is used, there is a problem that a large level difference exceeding 70 μm cannot be filled, for example. The filling of the step is referred to as “circuit filling ability”. For this reason, cracks, voids, and the like are generated at the adhesive interface, which causes the insulating characteristics to deteriorate.

  The epoxy resin composition of Patent Document 2 uses fused silica alone as a filler, and its thermal conductivity is not high. Since the epoxy resin composition of Patent Document 2 uses an acid anhydride as a curing agent, it easily reacts to temperature, and in applications such as resin sheets and prepregs that are premised on use in a semi-cured state, Since the curing reaction proceeds during storage, there is a problem that it is very difficult to apply to such applications.

  In view of the above situation, the present invention is a thermosetting resin composition capable of forming a cured product having high thermal conductivity and excellent insulation properties at high temperatures, high thermal conductivity, and excellent insulation properties at high temperatures. It is an object of the present invention to provide a resin sheet and a prepreg capable of forming a laminate, and a laminate having high thermal conductivity and excellent insulation at high temperatures.

The present invention includes the following aspects.
<1> a polyfunctional epoxy resin monomer having three or more epoxy groups in one molecule;
A polyfunctional amine compound having two or more primary amino groups in one molecule as a curing agent;
An aggregate of primary particles, wherein the average particle diameter d1 of the aggregate is 10 μm or more and 70 μm or less, and an inorganic filler (A);
An inorganic filler (b) having a particle shape and having an average particle diameter d3 of 1 μm or more and less than 10 μm, and a particle shape having an average particle diameter d4 of 0.1 μm or more and 1 μm An inorganic filler (B) containing less inorganic filler (c);
Including
The volume ratio [(b) :( c)] of the inorganic filler (b) and the inorganic filler (c) is 90:10 to 70:30,
The content of the inorganic filler (A) with respect to the total solid content is 10% by volume to 55% by volume, and the content of the inorganic filler (B) with respect to the total solid content is 10% by volume to 55% by volume,
The thermosetting resin composition whose total content rate of the said inorganic filler (A) and (B) is 30 volume%-80 volume%.

<2> The inorganic filler (B) further includes an inorganic filler (d) having a particle shape and an average particle diameter d2 of a single particle of 10 μm or more and 70 μm or less,
The volume ratio [(b) + (d) :( c)] of the total volume of the inorganic filler (b) and the inorganic filler (d) to the volume of the inorganic filler (c) is 90. : The thermosetting resin composition according to <1>, which is 10 to 70:30.

<3> A prepreg having a fiber base material and a semi-cured product of the thermosetting resin composition according to <1> or <2> impregnated in the fiber base material.

<4> A resin sheet which is a molded body of the thermosetting resin composition according to <1> or <2>.

<5> Adhering material, a layer comprising the thermosetting resin composition according to <1> or <2> disposed on the adhering material, the prepreg according to <3>, and <4> A laminate having at least one semi-cured product or a cured resin layer selected from the group consisting of the resin sheets described in 1.

  According to the present invention, there are provided a resin composition having high thermal conductivity and excellent insulation at high temperatures, and a resin sheet, prepreg and laminate having high thermal conductivity and excellent insulation at high temperatures. Is possible.

  In the present specification, a numerical range indicated using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively. Further, in the present specification, the amount of each component in the composition is the total amount of the plurality of substances present in the composition unless there is a specific indication when there are a plurality of substances corresponding to each component in the composition. Means.

  In this specification, the term “layer” includes a configuration formed in a part in addition to a configuration formed in the entire surface when observed as a plan view.

<Thermosetting resin composition>
The thermosetting resin composition of the present invention comprises a polyfunctional epoxy resin monomer having three or more epoxy groups in one molecule, and a polyfunctional amine having two or more primary amino groups in one molecule as a curing agent. A compound and an aggregate of primary particles, the average particle diameter d1 of the aggregate is 10 μm or more and 70 μm or less of the inorganic filler (A), the shape is particulate, and the average particle diameter d3 of the single particle is Inorganic filler (B) having an inorganic filler (b) of 1 μm or more and less than 10 μm, and an inorganic filler (c) having a particle shape and an average particle diameter d4 of a single particle of 0.1 μm or more and less than 1 μm And including
The volume ratio [(b) :( c)] of the inorganic filler (b) and the inorganic filler (c) is 90:10 to 70:30, and the content of the inorganic filler (A) with respect to the total solid content Is 10 volume% to 55 volume%, the content of the inorganic filler (B) with respect to the total solid content is 10 volume% to 55 volume%, and the total content of the inorganic fillers (A) and (B) is It is a thermosetting resin composition which is 30 volume%-80 volume%.
The thermosetting resin molding material may further contain other components as necessary.

By using a polyfunctional epoxy resin monomer having 3 or more epoxy groups in one molecule as the resin component, the crosslink density of the cured epoxy resin is increased, and the glass transition temperature (Tg) is improved. A thermosetting resin composition capable of forming a cured product having heat resistance is obtained.
By using a polyfunctional amine compound having two or more primary amino groups in one molecule as a curing agent, it is possible to form a cured product that is particularly excellent in insulation at high temperatures (hereinafter also referred to as “high temperature insulation”). A thermosetting resin composition is obtained.

By including an aggregate of primary particles having a specific average particle size (inorganic filler (A)) as one of the inorganic fillers, in the prepreg or the resin sheet, the aggregates are formed depending on the pressure at the time of heating and pressing. Can be easily deformed, so the compression ratio of the prepreg or resin sheet (change in thickness before and after heat and pressure molding) can be increased, the circuit fillability can be improved, and the insulation characteristics when a laminate is obtained. Can be improved.
Further, as the inorganic filler, an inorganic filler that is an aggregate of primary particles is used by using an inorganic filler (inorganic fillers (b) and (c)) that has a particle shape and a specific average particle size. By filling the gaps in the material (A), it is considered that a heat flow path can be secured and the heat dissipation characteristics can be improved.
Below, each component is demonstrated.

[Multifunctional epoxy resin monomer]
The thermosetting resin composition of the present invention contains a polyfunctional epoxy resin monomer having three or more epoxy groups in one molecule (hereinafter also referred to as “polyfunctional epoxy resin monomer”). The polyfunctional epoxy resin monomer is not particularly limited as long as it is a polyfunctional epoxy resin monomer having three or more epoxy groups in one molecule, and can be appropriately selected from commonly used polyfunctional epoxy resin monomers. The number of epoxy groups in the polyfunctional epoxy resin monomer may be three or more, preferably 3 to 8, and more preferably 3 to 5.

Examples of the polyfunctional epoxy resin monomer in the present invention include triphenylmethane type epoxy resin monomer, tetrakisphenol ethane type epoxy resin monomer, bisphenol A type epoxy resin monomer, phenol novolac type epoxy resin monomer, glycidylamine type epoxy resin monomer, Examples thereof include naphthalene skeleton type epoxy resin monomers and derivatives thereof. These may be used alone or in combination of two or more.
By using these polyfunctional epoxy resin monomers, the crosslinking density of the thermosetting resin composition increases and the glass transition temperature (Tg) tends to be improved. By improving the crosslink density, the intermolecular movement is suppressed, so that a decrease in insulation at high temperatures tends to be suppressed.

  From the viewpoint of heat resistance, the polyfunctional epoxy resin monomer is preferably a tetrafunctional glycidylamine type epoxy resin monomer or a triphenylmethane type epoxy resin which is a novolac type epoxy resin having a triphenylmethane skeleton. More preferred is a phenylmethane type epoxy resin.

Triphenylmethane type epoxy resin monomers are available as Nippon Kayaku Co., Ltd. trade name EPPN-502H, Mitsubishi Chemical Corporation trade name 1032H60, and the like.
The tetrafunctional glycidylamine type epoxy resin monomer is available as a trade name SKE-3 of Technoset.
As the polyfunctional epoxy resin monomer in the present invention, trade name VG-3101 of Printec Co., Ltd. can also be used.

  The epoxy equivalent of the polyfunctional epoxy resin monomer is not particularly limited. However, from the viewpoint of heat resistance, the epoxy equivalent of the polyfunctional epoxy resin is preferably 100 g / eq to 1000 g / eq, and more preferably 150 g / eq to 500 g / eq. Here, the epoxy equivalent is the mass (g) per mole of epoxy groups contained in the polyfunctional epoxy resin.

  From the viewpoint of heat resistance, the content of the polyfunctional epoxy resin monomer in the thermosetting resin composition is preferably 3% by mass to 15% by mass, and more preferably 5% by mass to 12% by mass.

[Polyfunctional amine compound having two or more primary amino groups in one molecule]
The thermosetting resin composition of the present invention contains a polyfunctional amine compound having two or more primary amino groups in one molecule (hereinafter also referred to as “polyfunctional amine compound”) as a curing agent.
The polyfunctional amine compound having two or more primary amino groups in one molecule is not particularly limited as long as it is a polyfunctional amine compound having two or more primary amino groups, and is a polyfunctional amine compound usually used as a curing agent in the technical field. It can be used by appropriately selecting from functional amine compounds. The number of primary amino groups in the polyfunctional amine compound may be two or more, preferably 2 to 6, and more preferably 2 to 4.

The molecular structure of the polyfunctional amine compound according to the present invention is not particularly limited, and bisphenol A type amine compound, bisphenol F type amine compound, bisphenol S type amine compound, naphthalene type amine compound, biphenyl type amine compound, etc. A polyfunctional amine compound having a rigid skeleton containing a benzene ring is preferred.
When cross-linking occurs due to the reaction between the polyfunctional epoxy resin monomer and the polyfunctional amine compound, the hydroxyl group at the epoxy end is less likely to occur than at the phenol end. Since hydroxyl groups are polarized and easily conduct electricity at high temperatures, it is considered that the combination of an epoxy resin and a polyfunctional amine compound that do not easily generate hydroxyl groups improves the insulation properties, particularly at high temperatures. Since a maximum of two epoxy groups can be bonded to the primary amino group, the rigidity of the molecule is improved and the molecular motion can be suppressed, which is preferable.

  The molecular structure of the polyfunctional amine compound according to the present invention is more preferably a bisphenol A type amine compound, a bisphenol F type amine compound, a bisphenol S type amine compound or the like, or a derivative thereof.

Examples of the polyfunctional amine compound according to the present invention include 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylsulfone, 4,4′-diamino-3,3′-. Bifunctional amine compounds such as dimethoxybiphenyl, 4,4′-diaminophenylbenzoate, 1,5-diaminonaphthalene, 1,3-diaminonaphthalene, 1,4-diaminonaphthalene, 1,8-diaminonaphthalene and the like can be mentioned.
Among these, from the viewpoint of thermal conductivity, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylsulfone, 4,4′-diamino-3,3′-dimethoxybiphenyl and 4 , 4′-diaminophenylbenzoate is preferable, and 4,4′-diaminodiphenylmethane is more preferable.

  The content of the polyfunctional amine compound in the thermosetting resin composition is not particularly limited. For example, the ratio of the active hydrogen equivalent (amine equivalent) of the polyfunctional amine compound to the epoxy equivalent of the epoxy resin monomer (amine equivalent / epoxy equivalent) is preferably 0.8 to 1.2, 0.9 It is more preferable to be -1.1.

[Inorganic filler]
The thermosetting resin composition of the present invention is an aggregate of primary particles, the average particle diameter d1 of the aggregate is 10 μm or more and 70 μm or less of the inorganic filler (A), and the shape is particulate. Inorganic packing containing a component (b) having an average particle diameter d3 of 1 μm or more and less than 10 μm and a component (c) having a particle shape and an average particle diameter d4 of a particle itself of 0.1 μm or more and less than 1 μm Material (B).
The inorganic filler (B) may further include an inorganic filler (d) having a particle shape and an average particle diameter d2 of a single particle of 10 μm to 70 μm. The inorganic filler (b) and the inorganic filler The volume ratio [(b) + (d) :( c)] of the total volume with the material (d) and the volume of the inorganic filler (c) is 90:10 to 70:30.

  The average particle diameters d1, d2, d3, and d4 are measured using a known particle size measuring apparatus using a laser diffraction scattering method (for example, Nikkiso Co., Ltd., “Microtrack SPA-7997 type”). Here, the laser diffraction scattering method is a measurement method that utilizes the fact that the intensity pattern of the scattered light changes according to the particle diameter when the inorganic filler particles are irradiated with laser light.

  Since the inorganic filler (A) has a large average particle size of aggregates, the contact area between the aggregates of the inorganic filler (A) tends to be small. Moreover, since the aggregate is deformed by the pressure of the heat and pressure molding, the aggregate of the inorganic filler (A) can be easily formed. Therefore, it is difficult to obtain high thermal conductivity only with the inorganic filler (A). Therefore, the inorganic fillers (b) and (c) are contained in such a shape that the particles have an average particle diameter smaller than that of the aggregate of the inorganic filler (A), and the inorganic filler (A) is agglomerated. By filling the gaps between the aggregates, the inorganic fillers (b) and (c) enter between the aggregates, and the particles of the inorganic filler (A) and the inorganic fillers (b) and (c) There is a tendency that a heat flow path formed in a continuous manner can be secured and the heat dissipation characteristics can be improved.

In order to achieve high heat dissipation characteristics using only the inorganic fillers (b) and (c), it is necessary to increase the filling amount. When the filling amount of the inorganic fillers (b) and (c) is increased, the fluidity at the time of molding the thermosetting resin composition is deteriorated, and voids, creases and the like are generated, and insulation properties, particularly insulation at high temperatures. Tend to decrease.
That is, the thermal conductivity in the thickness direction tends not to be secured only with the inorganic filler (A) or the inorganic fillers (b) and (c).

  In addition, when only an inorganic filler (A) and an inorganic filler (b) are used, it will be easy to form a close packed structure, and it exists in the tendency for the fluidity | liquidity at the time of a shaping | molding process of a thermosetting resin composition to fall. Therefore, by adding the inorganic filler (c) having a smaller average particle diameter, the particles of the inorganic filler (c) improve the fluidity of the particles of the inorganic filler (A) and the inorganic filler (b). be able to.

  When the average particle diameter d2 of the inorganic filler (d) is 10 μm or more, the interface between the epoxy resin and the inorganic filler (d) decreases in the insulating layer (cured product of the thermosetting resin composition). The thermal resistance tends to be small and the thermal conductivity tends to be improved. When the average particle diameter d2 is 70 μm or less, it becomes difficult to absorb moisture from the interface between the epoxy resin and the inorganic filler (d), so that the insulating characteristics tend to be improved.

In order to achieve high thermal conductivity only with the inorganic fillers (b) and (c), it is necessary to increase the filling amount, and the compressibility of the prepreg (change in thickness before and after heat-pressure molding) is small. Therefore, the circuit filling property tends to be lowered.
That is, even if only one of the inorganic filler (b) and the inorganic filler (c) is used, the thermal conductivity tends not to be ensured. When the average particle diameter of the inorganic filler (b) is within the above-mentioned range, the gap between the aggregate particles of the inorganic filler (A) can be sufficiently filled, and the thermal conductivity and the insulation at high temperature can be achieved. Can be secured.

The total content of the inorganic fillers (A) and (B) is 30% by volume to 80% by volume and 40% by volume to 75% by volume with respect to the total solid content of the thermosetting resin composition. Is preferred. When the total content of the inorganic fillers (A) and (B) is 30% by volume or more, sufficient thermal conductivity can be secured, and when it is 80% by volume or less, the viscosity of the varnish does not increase too much, and the appearance It is possible to produce a uniform prepreg.
In addition, the total solid content of a thermosetting resin composition means the total amount of a non-volatile component among the components which comprise a resin composition.

(Inorganic filler (A))
The inorganic filler (A) is not particularly limited as long as it is an aggregate of primary particles and the average particle diameter d1 of the aggregate is 10 μm or more and 70 μm or less, and is usually used in the technical field. It can be used by appropriately selecting from inorganic fillers.
The material of the inorganic filler (A) is preferably boron nitride, alumina, silica, titanium oxide or the like, and particularly preferably boron nitride.
Boron nitride has a Mohs hardness of 2, which is lower and softer than other insulating ceramics such as alumina (for example, hardness 8). Furthermore, since the aggregate of primary particles has voids inside the particles, the particles themselves are easily deformed while being harder than the molten resin. As a result, it can be easily deformed by an external force, and can be deformed when a heating and pressurizing step described later is performed, and the resin is excluded from between the inorganic fillers (A) during this deformation. Can do. For this reason, the inorganic fillers (A) can easily approach each other, and it becomes easy to form a structure in which a large particle diameter filler containing boron nitride is continuously in contact with the inside of the resin composition layer, It can be considered that the thermal conductivity is dramatically improved.

  Since the inorganic filler (A) is an aggregate of primary particles and easily deforms depending on the pressure at the time of heat and pressure molding, the compressibility of the prepreg (before and after the heat and pressure molding is obtained by including this aggregate. Thickness change) can be increased.

The average particle diameter d1 of the aggregate of the inorganic filler (A) is 10 μm or more and 70 μm or less, and preferably 15 μm or more and 50 μm or less.
When the average particle diameter d1 of the inorganic filler (A) is 10 μm or more, the compression ratio of the prepreg (change in thickness before and after heat and pressure molding) increases, and cracks tend not to occur at the adhesive interface of the prepreg. is there. When the average particle diameter d1 is 70 μm or less, it becomes difficult to absorb moisture from the interface between the epoxy resin and the inorganic filler (A), so that the insulating characteristics tend to be improved.

(Inorganic filler (B))
The material of the inorganic filler (B) is preferably alumina, silica, titanium oxide, acid value zinc or the like. The inorganic fillers (b), (c) and (d) contained in the inorganic filler (B) may be the same or different. The shape of the particles of the inorganic filler (B) is preferably spherical from the viewpoint of improving fluidity.
From the viewpoint of improving the thermal conductivity of the insulating layer, the inorganic filler (B) preferably has a thermal conductivity of 30 W / m · K or more.

The material of the inorganic fillers (b) and (c) is more preferably alumina, silica or titanium oxide, and further preferably alumina.
The material of the inorganic filler (d) is more preferably alumina, silica, titanium oxide or zinc oxide, and further preferably alumina.

  In the thermosetting resin composition of the present invention, the inorganic filler (B) further includes an inorganic filler (d) in addition to the inorganic fillers (b) and (c), and the inorganic filler (b) and The volume ratio [(b) + (d) :( c)] of the total volume of (d) and the volume of the inorganic filler (c) is preferably 90:10 to 70:30. When the volume ratio is in the above range, it is not necessary to increase the amount of the inorganic filler (A) that can inhibit the fluidity of the thermosetting resin composition, and the thermal conductivity of the resin composition is reduced. Formability can be improved without any problems. Furthermore, when the average particle diameter d4 of the inorganic filler (c) is within the above range, the gaps between the aggregate particles of the inorganic filler (A) can be sufficiently filled, and heat dissipation characteristics can be ensured. it can.

  The volume ratio [(b) + (d) :( c)] of the total volume of the inorganic filler (b) and the inorganic filler (d) and the volume of the inorganic filler (c) is as described above. 90:10 to 70:30 is preferable, and 90:10 to 80:20 is more preferable from the viewpoint of improving thermal conductivity and circuit filling performance. The particles of the inorganic filler (c) have an effect of improving the fluidity of the particles of the inorganic filler (b) and the inorganic filler (d), and the volume ratio of the inorganic filler (c) is 10 or more. And content of an inorganic filler (c) becomes appropriate, and the fluidity | liquidity of a thermosetting resin composition improves. When the volume ratio of the inorganic filler (c) is 30 or less, it is possible to improve the thermal conductivity without inhibiting the filling of the particles of the inorganic filler (d) and the inorganic filler (b).

  The volume ratio [(d) :( b)] of the volume of the inorganic filler (d) and the volume of the inorganic filler (b) is preferably 75: 25-60: 40, and the thermal conductivity and circuit From the viewpoint of improving fillability, it is more preferably 70:30 to 60:40. Thereby, since it becomes difficult to form a close-packed structure, fluidity can be secured. When the volume ratio of the inorganic filler (b) is 25 or more, it is difficult to form a close-packed structure, and thus fluidity tends to be improved. When the volume ratio is 40 or less, the filling property is improved and the thermal conductivity tends to be improved.

[Other ingredients]
The thermosetting resin composition of the present invention may further contain other components such as a curing accelerator, a flame retardant, a diluent, a plasticizer, a coupling agent, and a lubricant as necessary. When manufacturing a prepreg or a resin sheet using the thermosetting resin composition of this invention, a solvent can be used as needed. These uses do not affect the thermal conductivity of the cured product.

(Curing accelerator)
It does not specifically limit as a hardening accelerator, The hardening accelerator conventionally used in order to advance the polycondensation reaction of a polyfunctional epoxy resin monomer and a polyfunctional amine compound can be used. Examples of the curing accelerator include triphenylphosphine, imidazole or a derivative thereof, a tertiary amine compound or a derivative thereof, and the like.

(Lubricant)
As the lubricant, it is preferable to use a lubricant having an average particle diameter of 0.001 μm to 0.05 μm. Examples of the material for the lubricant include alumina, silica, titanium oxide, and zinc oxide. The lubricant has an action of causing the inorganic fillers (b), (c) and (d) to flow, and when curing the thermosetting resin composition, the inorganic fillers (b), (c) and (D) It fills in the clearance gap between the particles, and also has an effect of improving thermal conductivity. The content of the lubricant is preferably 0.5% by mass to 2% by mass with respect to the total solid content of the thermosetting resin composition. When the content of the lubricant is 0.5% by mass or more, the effect of improving the fluidity is sufficiently obtained. When the content is 2% by mass or less, the generation of voids is suppressed without impairing the filling property. In addition, the thermal conductivity can be improved.

(solvent)
In the case of a liquid, the epoxy resin composition of the present invention may contain a solvent in order to reduce the viscosity.
Solvents include acetone, isobutyl alcohol, isopropyl alcohol, isopentyl alcohol, ethyl ether, ethylene glycol monoethyl ether, xylene, cresol, chlorobenzene, isobutyl acetate, isopropyl acetate, isopentyl acetate, ethyl acetate, methyl acetate, cyclohexanol, cyclohexanone. 1,4-dioxane, dichloromethane, styrene, tetrachloroethylene, tetrahydrafuran, toluene, normal hexane, 1-butanol, 2-butanol, methanol, methyl isobutyl ketone, methyl ethyl ketone, methylcyclohexanol, methylcyclohexanone, chloroform, carbon tetrachloride Use organic solvents that are generally used in the manufacturing technology of various chemical products such as 1,2-dichloroethane Rukoto can.

<Resin sheet>
The resin sheet of the present invention is a molded body of the thermosetting resin composition of the present invention. The resin sheet can be produced, for example, by applying the thermosetting resin composition of the present invention on a support and removing at least part of the solvent contained as necessary. A resin sheet is excellent in thermal conductivity and insulation at high temperature by being formed from a thermosetting resin composition.

  The thickness of the resin sheet is not particularly limited and can be appropriately selected according to the purpose. For example, the thickness can be 50 μm to 500 μm, and is preferably 80 μm to 300 μm from the viewpoints of thermal conductivity, insulation, and flexibility.

  The resin sheet is, for example, a varnish-like thermosetting resin composition (hereinafter also referred to as “resin varnish”) prepared by adding an organic solvent such as methyl ethyl ketone or cyclohexanone to the thermosetting resin composition of the present invention. After the resin varnish film is formed on the support, it can be produced by removing at least part of the organic solvent from the resin varnish film and drying it. An example of the support is a release film such as a PET film.

  Application | coating of a resin varnish can be implemented by a well-known method. Specifically, it can be performed by a method such as comma coating, die coating, lip coating, or gravure coating. Examples of a method for forming a resin varnish layer having a predetermined thickness include a comma coating method in which an object to be coated is passed between gaps, and a die coating method in which a resin varnish with a flow rate adjusted from a nozzle is applied. For example, when the thickness of the resin varnish film before drying is 50 μm to 500 μm, it is preferable to use a comma coating method.

  The drying method is not particularly limited as long as at least a part of the organic solvent contained in the resin varnish can be removed, and can be appropriately selected from commonly used drying methods according to the organic solvent contained in the resin varnish. In general, a heat treatment method at about 80 ° C. to 150 ° C. can be mentioned.

  The resin sheet hardly undergoes curing reaction. For this reason, although it has flexibility, its flexibility as a sheet is poor. Therefore, in a state where a support such as a PET film is removed, the sheet self-supporting property is poor and handling may be difficult.

  For the above reasons, it is preferable that the resin sheet is obtained by semi-curing a layer made of the thermosetting resin composition of the present invention. That is, the resin sheet is preferably a B stage sheet that is further heat-treated until the thermosetting resin composition layer is in a semi-cured state (B stage state). By semi-curing the thermosetting resin composition layer, it is possible to obtain a resin sheet having excellent thermal conductivity and insulating properties, and excellent flexibility and usable time as a B stage sheet.

  The conditions for heat-treating the resin sheet are not particularly limited as long as the thermosetting resin composition layer can be in a B-stage state. The conditions for the heat treatment can be appropriately selected according to the configuration of the thermosetting resin composition. The heat treatment is preferably performed by a method selected from hot vacuum press, hot roll laminating and the like in order to reduce voids in the resin varnish film generated when the resin varnish is applied. Thereby, the B stage sheet | seat with a flat surface can be manufactured efficiently.

  Specifically, for example, the resin varnish layer is subjected to a B-stage by heating and pressurizing under a reduced pressure (eg, 1 kPa) at a temperature of 80 ° C. to 200 ° C. for 1 minute to 3 minutes with a press pressure of 1 MPa to 20 MPa. It can be semi-cured to the state.

  In addition, after applying a thermosetting resin composition on a support and bonding two resin sheets in a dry state, the above heating / pressurization treatment is performed to semi-cure to a B stage state. preferable. At this time, it is desirable that the application surfaces (the surfaces where the thermosetting resin composition layer is not in contact with the support) of the thermosetting resin composition layer are bonded together. When pasted together so that the thermosetting resin composition layers are in contact with each other, both surfaces of the resulting B-stage resin sheet (that is, the surface exposed by peeling off the support) become more flat and adhere to the adherend. Property is improved. A laminated board, a metal board, a printed wiring board, etc., which will be described later, produced using such a resin sheet exhibit high thermal conductivity.

  The thickness of the B stage sheet can be appropriately selected according to the purpose. For example, it can be set to 50 μm to 500 μm, and is preferably 80 μm to 300 μm from the viewpoints of thermal conductivity, insulation, and flexibility. It can also be produced by hot pressing while laminating two or more resin sheets.

  The solvent remaining rate in the B stage sheet is preferably 2.0% by mass or less, and preferably 0.5% by mass to 1% from the viewpoint of suppressing bubble formation due to outgas generation when the thermosetting resin composition layer is cured. More preferably, it is 0.0 mass%. The solvent remaining rate is obtained by drying a sample obtained by cutting a B-stage sheet into a 40 mm square for 2 hours in a thermostatic bath preheated to 190 ° C., and determining the change in mass before and after drying.

  The resin sheet may be a cured product obtained by curing the thermosetting resin composition layer. A resin sheet having a cured product of the thermosetting resin composition can be produced by curing the uncured resin sheet or B stage sheet. Although the method of a hardening process can be suitably selected according to the structure of a thermosetting resin composition, the use purpose of the hardened | cured material of a thermosetting resin composition, etc., it is preferable that it is a heat-pressing process.

For example, the thermosetting resin composition is cured by heating an uncured resin sheet or B stage sheet at 100 ° C. to 250 ° C. for 5 minutes to 5 hours, preferably 130 ° C. to 230 ° C. for 10 minutes to 2 hours. A resin sheet made of a product is obtained. The heat treatment is preferably performed while applying a pressure of 1 MPa to 20 MPa.
Further, it is more preferable to perform post-curing at 130 to 230 ° C. and atmospheric pressure for 30 minutes to 4 hours after pressing.

  The resin sheet which consists of the hardened | cured material of the thermosetting resin composition obtained by the said method has high heat conductivity and high heat resistance. The following method is mentioned as an example of the method of manufacturing the resin sheet which consists of hardened | cured material of a thermosetting resin composition. First, a B stage sheet is sandwiched so as to be in contact with two matte surfaces of copper foil (thickness 80 to 120 μm) each having a matte surface, and a temperature of 130 ° C. to 230 ° C. for 3 minutes to 10 minutes, a pressure of 1 MPa. A heat and pressure treatment is performed at ˜20 MPa, and a copper foil is adhered to both surfaces of the B stage sheet. Subsequently, the B stage sheet is heated at 130 to 230 ° C. for 1 to 8 hours. Thereafter, the copper foil portion of the resin sheet is removed by etching treatment to obtain a resin sheet made of a cured product of the thermosetting resin composition.

<Prepreg>
The prepreg of the present invention has a fiber substrate and a semi-cured product of the thermosetting resin composition of the present invention impregnated in the fiber substrate. By using the prepreg of the present invention having such a configuration, a laminate having excellent thermal conductivity and high temperature insulation can be formed.
In the present invention, a generally used production method can be applied to the production of the prepreg. For example, the sheet-like fiber base material is impregnated with the varnish of the thermosetting resin composition of the present invention and dried by heating to prepare a prepreg. The varnish may be applied (applied) to a releasable film or the like and dried by heating to make a semi-cured state as a prepreg.

The sheet-like fiber base material used in the present invention is a woven fabric or nonwoven fabric such as glass fiber or organic fiber, and is not particularly limited. It is preferable to use a nonwoven fabric base material from the viewpoint that the compression ratio of the prepreg (change in thickness before and after heat-pressure molding) is large and the circuit filling property is good.
A glass fiber woven fabric can also be used as the sheet-like fiber base material. The glass constituting the glass fiber is preferably E glass having good strength, electrical properties, and the like. In the case of using a glass fiber woven fabric, a glass fiber woven fabric that has not been subjected to fiber opening treatment is preferable because a large amount of open space is preferable from the viewpoint of impregnation with varnish.

  When the varnish is applied to a releasable film or the like to form a semi-cured state, the mold is released after the varnish is applied to a releasable film such as polyethylene terephthalate, polyethylene, polypropylene, or polystyrene to obtain a semi-cured state. May be peeled off and used after being applied to a metal foil such as a copper foil or an aluminum foil to be in a semi-cured state, and then directly attached to a metal plate, a metal foil or the like. It is not a thing.

<Laminated plate>
The laminated board of the present invention is also referred to as an adherend and a layer made of the thermosetting resin composition of the present invention (hereinafter referred to as “thermosetting resin composition layer”) disposed on the adherend. And a resin layer that is at least one semi-cured product or cured product selected from the group consisting of the prepreg of the present invention and the resin sheet of the present invention.

  Examples of the adherend include metal foil and metal plate.

  The metal foil is not particularly limited and can be appropriately selected from commonly used metal foils. Specifically, gold foil, copper foil, aluminum foil, etc. can be mentioned, and copper foil is generally used. The thickness of the metal foil is not particularly limited as long as it is 1 μm to 400 μm. A suitable thickness can be selected according to the power used.

  As metal foil, nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, lead-tin alloy, etc. are used as intermediate layers, and 0.5 μm to 15 μm copper layer and 10 μm to 150 μm copper on both surfaces. A composite foil having a three-layer structure in which layers are provided, or a two-layer structure composite foil in which aluminum and a copper foil are combined can also be used.

  The metal plate is preferably made of a metal material having a high thermal conductivity and a large heat capacity. Specific examples include copper, aluminum, iron, alloys used for lead frames, and the like.

  The plate | board thickness of a metal plate can be suitably selected according to a use. For example, the material of the metal plate can be selected according to the purpose, such as aluminum when priority is given to weight reduction and workability, and copper when priority is given to heat dissipation.

  The laminate may be in a form having any one of a layer comprising the thermosetting resin composition of the present invention, a prepreg of the present invention and a resin sheet of the present invention as a cured composition layer, and two or more layers may be provided. It may be in the form of being stacked. In the case of having two or more curable composition layers, either a form having two or more thermosetting resin composition layers or a form having two or more prepregs or resin sheets may be used. Furthermore, you may have combining 2 or more selected from the group which consists of a thermosetting resin composition layer, a prepreg, and a resin sheet.

  The laminated board of the present invention is formed, for example, by applying the thermosetting resin composition of the present invention on an adherend to form a thermosetting resin composition layer, and heat-pressing it to form a thermosetting resin. It is obtained by making the resin composition layer semi-cured or cured and in close contact with the adherend. Prepared by laminating the resin sheet or prepreg of the present invention on the adherend, and heat-pressing it to obtain a semi-cured or cured resin sheet or prepreg and adhere to the adherend. Also good.

  The method for semi-curing or curing the thermosetting resin composition layer, the resin sheet, and the prepreg is not particularly limited. For example, a heat and pressure treatment is preferable. The heating temperature in the heat and pressure treatment is not particularly limited. Usually, it is the range of 100 to 250 degreeC, Preferably it is the range of 130 to 230 degreeC. The pressurization conditions in the heat and pressure treatment are not particularly limited. Usually, it is in the range of 1 MPa to 20 MPa, preferably in the range of 1 MPa to 15 MPa. It is preferable to use a vacuum press for the heat and pressure treatment.

The thickness of the resin layer (insulating layer) that is a semi-cured product or a cured product is preferably 1000 μm or less, and more preferably 50 μm to 400 μm. When the thickness is 1000 μm or less, the flexibility is excellent and the generation of cracks during bending is suppressed, and when the thickness is 400 μm or less, this tendency is more apparent. When the thickness is 50 μm or more, the workability is excellent.
Specifically, the laminate of the present invention is formed by heat-pressure molding the whole or a part of the above-mentioned resin sheet or prepreg, and copper or copper on one or both sides by the heat-pressure molding as necessary. A metal foil such as a foil may be bonded together. The above-mentioned resin sheet or prepreg can also be used as an adhesive layer when a previously prepared printed wiring board is stacked and integrated to form a multilayer printed wiring board.

  The above printed wiring board has good thermal conductivity of the insulating layer, excellent heat dissipation, and excellent insulation properties at high temperatures, so printed wiring boards for automobile equipment and high-density mounting printed wiring such as personal computers It is suitable for insulating materials such as plates and inverters.

  Examples of the present invention will be described below, and the present invention will be described in detail. In the following examples and comparative examples, “part” means “part by mass”. The present invention is not limited to the present embodiment unless departing from the gist thereof.

[Example 1]
(Production of epoxy resin varnish)
100 parts of a triphenylmethane type epoxy resin monomer (Nippon Kayaku, “EPPN-502H”; epoxy equivalent 169) as an epoxy resin monomer component, and 4,4′-diaminodiphenylmethane (Wako Pure Chemical, “DDM” as a curing agent) ”; 34 parts of amine equivalent 58) was dissolved in 200 parts of methyl isobutyl ketone (Wako Pure Chemical Industries, Ltd.) at 100 ° C., and then the mixture was returned to room temperature.
Boron nitride as inorganic filler (A) (Momentive Performance Materials Japan GK, “PTX25”; particle shape: aggregate of primary particles; average particle size: 25 μm; thermal conductivity 60 W / M · K) 138 parts (corresponding to 30% by volume of the total solid content in the epoxy resin varnish; hereinafter also referred to as “volume%”) and alumina as a mineral filler (B) (Suika Alchem ( Co., Ltd., “AA-3”; particle shape: particulate shape; average particle size: 3 μm; thermal conductivity 30 W / m · K) 56 parts (corresponding to 7% by volume of the total solid content) and alumina (Suika Alchem ( Co., Ltd., “AA-04”; particle shape: particulate shape; average particle size: 0.4 μm; thermal conductivity 30 W / m · K,) 24 parts (corresponding to 3% by volume of total solids) and methyl isobutyl Add 67 parts of ketone (Wako Pure Chemicals) and knead it. A xy resin varnish (thermosetting resin composition) was prepared.

The epoxy resin varnish was impregnated into a glass fiber woven fabric having a thickness of 60 μm (open space: 0.02 mm ² ) so that the weight ratio was 50% or more, and dried by heating to obtain a semi-cured prepreg.

  Four prepregs prepared as described above and 35 μm-thick copper foil (Fukuda Metal Foil Powder Co., Ltd., CF-T9C) are placed on both sides of the prepreg and heated and pressure-molded for 90 minutes under conditions of a temperature of 175 ° C. and a pressure of 4 MPa. To obtain a laminate having a thickness of 0.4 mm.

  About the laminated board obtained in Example 1, the result of having evaluated the heat conductivity and high temperature insulation of the thickness direction is put together in Table 1 with the compounding composition of an epoxy resin composition. The measuring method is as follows.

  The average particle size of the inorganic filler was measured using “Microtrac SPA-7997 type” manufactured by Nikkiso Co., Ltd.

(Thermal conductivity in the thickness direction)
A 10 mm × 10 mm plate sample was cut out from the produced laminate, and the thermal conductivity in the thickness direction of the laminate was measured at room temperature in accordance with the xenon flash method (ASTM E1461). The measurement results are shown in Table 1.
In Table 1, Examples or Comparative Examples in which prepregs or laminates could not be produced due to thickening of the epoxy resin varnish were indicated by “−”.

(High temperature insulation)
Insulation resistance was measured by the following method as an index of high temperature insulation. A plate-like sample was prepared by removing the copper foil at the end of the produced laminate (50 mm × 50 mm) by etching 5 mm on each side. A voltage of 1000 V was applied between the double-sided copper foils of this plate-like sample, and after treatment for 1000 hours in a 100 ° C. thermostat, the insulation resistance of the insulating layer was measured.
The higher the insulation resistance, the better the insulation. If the measured insulation resistance is 1.0 × 10 ⁹ Ω or more, “A” is given, and 1.0 × 10 ⁸ Ω or more and less than 1.0 × 10 ⁹ Ω “B” if present, and “C” if less than 1.0 × 10 ⁸ Ω. The measurement results are shown in Table 1.
In Table 1, Examples or Comparative Examples in which prepregs or laminates could not be produced due to thickening of the epoxy resin varnish were indicated by “−”.

  As shown in Table 1, in Example 1, the thermal conductivity in the thickness direction of the laminated plate was 5.2 W / m · K, and the high-temperature insulation was also good as “A”.

[Examples 2 to 6]
In Example 1, the total amount of the epoxy resin monomer and the curing agent, the average particle diameter of the inorganic filler (A), the type or blending amount of the inorganic filler (B) were changed as shown in Table 1, respectively. Except using a varnish, the prepreg was manufactured like Example 1 and the laminated board of Examples 2-6 was obtained.

The inorganic filler used in Examples 2 to 6 is as follows.
Boron nitride (Momentive Performance Materials Japan GK, “PTX60”; particle shape: aggregate of primary particles; average particle size: 55 μm to 60 μm; thermal conductivity 60 W / m · K)
Alumina (Sumika Alchem Co., Ltd., “AA-18”; particle shape: particle shape; average particle size: 18 μm; thermal conductivity 30 W / m · K)
Silica (Electrochemical Industry Co., Ltd., “SFP-20M”; particle shape: particle shape; average particle size 0.3 μm; thermal conductivity 1.35 W / m · K)

Table 1 shows the results of measuring the thermal conductivity and high temperature insulation in the thickness direction of the laminates of Examples 2 to 6 in the same manner as in Example 1.
As shown in Table 1, when the total content of inorganic fillers (total content of inorganic fillers (A) and (B)) increases, the thermal conductivity in the thickness direction also improves, and the average of inorganic fillers As the particle size increased, the thermal conductivity in the thickness direction also improved. Furthermore, the high temperature insulation was also good.

[Comparative Examples 1-2]
In Example 1, the prepreg and the laminated board of Comparative Examples 1-2 were obtained like Example 1 except using the epoxy resin varnish which changed the combination of an epoxy resin and a hardening | curing agent as shown in Table 1. . The epoxy resin and curing agent used are as follows.
Bifunctional epoxy resin monomer (Mitsubishi Chemical Corporation, “jER828” (bisphenol A glycidyl ether); epoxy equivalent 169)
・ Phenolic curing agent (DIC Corporation, “LF6161”, OH equivalent 118)

  In Comparative Example 1, since the glass transition temperature (Tg) was lowered by lowering the crosslinking density of the epoxy resin, the insulation resistance at high temperature was lowered. In Comparative Example 2, since a phenolic curing agent was used, molecular motion at a high temperature could not be suppressed, and the high-temperature insulation decreased. Further, in Comparative Examples 1 and 2, the thermal conductivity was also lowered.

[Comparative Example 3]
The prepreg and laminate of Comparative Example 3 were obtained in the same manner as in Example 1 except that the inorganic filler (A) used in Example 1 was boron nitride having an average particle diameter of 100 μm. In addition, the used inorganic filler is as follows.

Boron nitride (Momentive Performance Materials Japan GK, “PT-350”; particle shape: aggregate of primary particles; average particle size: 100 μm; thermal conductivity 60 W / m · K)

Table 1 shows the results of measuring the thermal conductivity and high-temperature insulation in the thickness direction of the laminate of the obtained laminate in the same manner as in Example 1.
In Comparative Example 3, since the average particle size of boron nitride (aggregate) was large, the thermal conductivity in the thickness direction was good, but the high-temperature insulation was deteriorated.

[Comparative Example 4]
Comparative Example 4 was the same as Example 1 except that the ratio of “epoxy resin / curing agent” used in Example 1 was 65% by volume and the content of the filler (B) was changed to 5% by volume. A prepreg and a laminate were obtained.
Table 1 shows the results of measuring the thermal conductivity and high-temperature insulation in the thickness direction of the laminate of the obtained laminate in the same manner as in Example 1.
In Comparative Example 4, since the amount of alumina added is small and the amount of alumina present between the boron nitrides is reduced, it is difficult to make a heat conduction path, and the thermal conductivity is lowered.

Claims (5)

A polyfunctional epoxy resin monomer having three or more epoxy groups in one molecule;
A polyfunctional amine compound having two or more primary amino groups in one molecule as a curing agent and an aggregate of primary particles, wherein the average particle diameter d1 of the aggregate is 10 μm or more and 70 μm or less. (A), the inorganic filler (b) having a particle shape and an average particle diameter d3 of 1 μm or more and less than 10 μm, and a particle shape having an average particle diameter d4 of 1 μm or more and less than 10 μm. An inorganic filler (B) containing an inorganic filler (c) of 0.1 μm or more and less than 1 μm,
The volume ratio [(b) :( c)] of the inorganic filler (b) and the inorganic filler (c) is 90:10 to 70:30,
The content of the inorganic filler (A) with respect to the total solid content is 10% by volume to 55% by volume, and the content of the inorganic filler (B) with respect to the total solid content is 10% by volume to 55% by volume,
The thermosetting resin composition whose total content rate of the said inorganic filler (A) and (B) is 30 volume%-80 volume%. The inorganic filler (B) further includes an inorganic filler (d) having a particle shape and an average particle diameter d2 of the single particles of 10 μm to 70 μm,
The volume ratio [(b) + (d) :( c)] of the total volume of the inorganic filler (b) and the inorganic filler (d) to the volume of the inorganic filler (c) is 90. The thermosetting resin composition of Claim 1 which is: 10-70: 30.   The prepreg which has a fiber base material and the semi-hardened | cured material of the thermosetting resin composition of Claim 1 or Claim 2 which the said fiber base material is impregnated.   The resin sheet which is a molding of the thermosetting resin composition of Claim 1 or Claim 2.   The layer which consists of an adherend and the thermosetting resin composition of Claim 1 or Claim 2 arrange | positioned on the said adherend, The prepreg of Claim 3, and Claim 4 A laminate having at least one semi-cured product or a cured resin layer selected from the group consisting of resin sheets.