JP2018094919A - Laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate that can effectively improve insulation properties and can effectively improve heat conductivity.SOLUTION: The laminate comprises a heat conductor, an insulation layer laminated on one surface of the heat conductor, a conductive layer laminated on the surface on the opposite side to the side of the heat conductor. The insulation layer includes a binder, a nonspherical heat conductive filler, a spherical particle having a dielectric constant of 7 or less; a ratio of the particle size of the spherical particle to the thickness of the insulation layer is 0.7 to 0.95; and the spherical particle content in 100 vol% of the insulation layer is 1 vol% to 40 vol%.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminate including a binder and a filler.

  In recent years, downsizing and higher performance of electronic and electrical devices have progressed, and the mounting density of electronic components has increased. For this reason, it is a problem how to dissipate the heat generated from the electronic components in a narrow space. Since heat generated from electronic components is directly linked to the reliability of electronic and electrical equipment, efficient dissipation of the generated heat is an urgent issue.

  One means for solving the above problem is a thermally conductive material containing a thermally conductive filler.

  Patent Document 1 below discloses a heat conductive sheet including a heat conductive filler in a cured organic resin. The heat conductive filler is a particle in which the surface of a plastic particle is coated with a heat conductive material. The CV value (coefficient of variation) of the particle diameter of the plastic particles is 10% or less.

  Patent Document 2 below discloses an insulating heat dissipation film that includes organic particles, an inorganic filler, and a crosslinked rubber, and in which the inorganic filler has insulating properties and thermal conductivity. The ratio of the average particle diameter of the organic particles and the inorganic filler is organic particles / inorganic filler = 1/1 or more.

WO2014 / 119384A1 JP 2012-224711 A

  In the conventional heat conductive materials as described in Patent Documents 1 and 2, voids may remain between the particles of the heat conductive filler after forming a laminate or the like. As a result, although the thermal conductivity can be improved, the insulating property may be lowered. Conventional heat conductive materials have a limit in achieving both high insulation and high heat conductivity.

  The objective of this invention is providing the laminated body which can improve insulating property effectively and can improve thermal conductivity effectively.

  In a wide aspect of the present invention, a heat conductor, an insulating layer laminated on one surface of the heat conductor, and a conductive layer laminated on the surface of the insulating layer opposite to the heat conductor side are provided. The insulating layer includes a binder, a non-spherical heat conductive filler, and spherical particles having a dielectric constant of 7 or less, and a ratio of a particle diameter of the spherical particles to a thickness of the insulating layer is 0.7 or more. 0.95 or less, and in 100 volume% of the insulating layer, a laminate is provided in which the content of the spherical particles is 1 volume% or more and 40 volume% or less.

  On the specific situation with the laminated body which concerns on this invention, the CV value of the particle diameter of the said spherical particle is 10% or less.

  On the specific situation with the laminated body which concerns on this invention, the said heat conductive filler is boron nitride.

  On the specific situation with the laminated body which concerns on this invention, content of the said heat conductive filler is 45 volume% or more and 85 volume% or less in 100 volume% of said insulating layers.

  On the specific situation with the laminated body which concerns on this invention, the aggregate of a non-spherical heat conductive filler is included as the said heat conductive filler.

  On the specific situation with the laminated body which concerns on this invention, the total content of the said heat conductive filler and the said spherical particle is 46 volume% or more and 90 volume% or less in the said insulating layer 100 volume%.

  On the specific situation with the laminated body which concerns on this invention, the said spherical particle is a resin particle.

  The laminate according to the present invention includes a heat conductor, an insulating layer laminated on one surface of the heat conductor, and a conductive layer laminated on the surface of the insulating layer opposite to the heat conductor side. Is provided. In the laminate according to the present invention, the insulating layer contains a binder, a non-spherical heat conductive filler, and spherical particles having a dielectric constant of 7 or less. In the laminate according to the present invention, the ratio of the particle diameter of the spherical particles to the thickness of the insulating layer is 0.7 or more and 0.95 or less. In the laminated body which concerns on this invention, content of the said spherical particle is 1 volume% or more and 40 volume% or less in 100 volume% of said insulating layers. In the laminated body which concerns on this invention, since said structure is provided, insulation can be improved effectively and thermal conductivity can be improved effectively.

FIG. 1 is a cross-sectional view schematically showing a laminate according to an embodiment of the present invention. FIG. 2 is a cross-sectional view schematically showing an example of a semiconductor device using the stacked body according to one embodiment of the present invention.

  Hereinafter, the present invention will be described in detail.

(Laminate)
The laminate according to the present invention includes a heat conductor, an insulating layer, and a conductive layer. The insulating layer is laminated on one surface of the heat conductor. The conductive layer is laminated on the surface of the insulating layer opposite to the heat conductor side. The insulating layer may be laminated on the other surface of the heat conductor.

  In the laminate according to the present invention, the insulating layer contains a binder, a non-spherical heat conductive filler, and spherical particles having a dielectric constant of 7 or less.

  In the laminate according to the present invention, the ratio of the particle diameter of the spherical particles to the thickness of the insulating layer is 0.7 or more and 0.95 or less.

  In the laminated body which concerns on this invention, content of the said spherical particle is 1 volume% or more and 40 volume% or less in 100 volume% of said insulating layers.

  In the laminated body which concerns on this invention, since said structure is provided, insulation can be improved effectively and thermal conductivity can be improved effectively.

  In the laminate according to the present invention, when a compressive force is applied to the insulating layer by a press or the like for molding of the laminate, the spherical particles are not excessively deformed and serve as spacers. Function can be demonstrated. For this reason, the heat conductive filler is not excessively compressed by a press or the like, and the heat conductive filler is prevented from being excessively oriented in the surface direction. Moreover, the said heat conductive filler is arrange | positioned along the surface of the said spherical particle, and the effective heat conductive path in the thickness direction can be formed. As a result, thermal conductivity can be effectively increased not only in the surface direction but also in the thickness direction. Furthermore, in the laminate according to the present invention, the thermally conductive filler can fill the voids existing between the spherical particles, and can effectively enhance the insulation. In order to obtain such an effect, the combined use of a specific heat conductive filler and a specific spherical particle greatly contributes.

  From the viewpoint of more effectively increasing the insulation and from the viewpoint of increasing the thermal conductivity more effectively, the thickness of the insulating layer is preferably 50 μm or more, more preferably 80 μm or more, preferably 250 μm or less. More preferably, it is 200 μm or less.

  From the viewpoint of more effectively increasing the thermal conductivity, the thickness of the thermal conductor is preferably 30 μm or more, more preferably 50 μm or more, preferably 5000 μm or less, more preferably 2000 μm or less, and even more preferably 500 μm. Hereinafter, it is particularly preferably 200 μm or less.

  From the viewpoint of more effectively increasing the thermal conductivity, the thickness of the conductive layer is preferably 30 μm or more, more preferably 50 μm or more, preferably 10,000 μm or less, more preferably 5000 μm or less, and even more preferably 1000 μm or less. Particularly preferably, it is 500 μm or less.

(Insulating layer)
In the laminate according to the present invention, the insulating layer includes a binder, a non-spherical heat conductive filler, and spherical particles having a dielectric constant of 7 or less.

Spherical particles with a dielectric constant of 7 or less:
In the laminate according to the present invention, the insulating layer includes spherical particles having a dielectric constant of 7 or less. From the viewpoint of more effectively increasing the insulation, the dielectric constant of the spherical particles is preferably 5 or less, more preferably 4 or less. The lower limit of the dielectric constant of the spherical particles is not particularly limited. The spherical particles may have a dielectric constant of 2 or more. As for the said spherical particle, only 1 type may be used and 2 or more types may be used together.

  In the laminate according to the present invention, the ratio of the particle diameter of the spherical particles to the thickness of the insulating layer (the particle diameter of the spherical particles / the thickness of the insulating layer) is 0.7 or more and 0.95 or less. From the viewpoint of more effectively increasing the insulating properties and the viewpoint of increasing the thermal conductivity more effectively, the ratio of the particle diameter of the spherical particles to the thickness of the insulating layer is preferably 0.74 or more, more Preferably it is 0.8 or more, preferably 0.9 or less, more preferably 0.85 or less.

  From the viewpoint of further effectively increasing the thermal conductivity, the particle diameter of the spherical particles is preferably 50 μm or more, more preferably 80 μm or more, preferably 180 μm or less, more preferably 150 μm or less. When the particle diameter of the spherical particles is not less than the lower limit and not more than the upper limit, the thermally conductive filler is disposed along the surface of the spherical particles, thereby providing an effective heat conduction path in the thickness direction. It can be formed even more.

  The particle diameter of the spherical particles is preferably an average particle diameter obtained by averaging the particle diameters on a volume basis. The particle diameter of the spherical particles can be determined by measuring the diameter (maximum diameter portion) with a caliper or the like from the electron microscope image of the spherical particles and averaging the diameters of the 100 spherical particles.

  From the viewpoint of enhancing the insulation more effectively, the CV value of the particle diameter of the spherical particles is preferably 10% or less, more preferably 8% or less. The lower limit of the CV value of the particle diameter of the spherical particles is not particularly limited. The CV value of the particle diameter of the spherical particles may be 2% or more. When the CV value of the particle diameter of the spherical particles is not more than the above upper limit, the thermally conductive filler can further fill the voids existing between the spherical particles, and the generation of voids between the spherical particles can be prevented. Further suppression can be achieved.

  The CV value (coefficient of variation) of the particle diameter of the spherical particles is represented by the following formula.

CV value (%) = (ρ / Dn) × 100
ρ: Standard deviation of particle diameter of spherical particles having dielectric constant of 7 or less Dn: Average value of particle diameter of spherical particles having dielectric constant of 7 or less

  From the viewpoint of more effectively increasing the thermal conductivity, the compressive strength of the spherical particles at 30% compression is preferably 100 MPa or more, more preferably 150 MPa or more. The upper limit of the compressive strength at the time of 30% compression of the spherical particles is not particularly limited. The spherical particles may have a compressive strength at 30% compression of 500 MPa or less. When the compressive strength at 30% compression of the spherical particles is equal to or higher than the lower limit, the spherical particles are applied when a compressive force is applied to the insulating layer by a press or the like for molding a laminate. Is not excessively deformed and can further function as a spacer. As a result, the thermal conductive filler can be further prevented from being excessively oriented in the plane direction.

  The compressive strength at 30% compression of the spherical particles can be measured as follows.

  Using a microcompression tester, a square prism made of diamond is used as a compression member, and the smooth end surface of the compression member is lowered toward the particles to compress the spherical particles. As a result of the measurement, the relationship between the compression load value and the compression displacement is obtained. The compression load value per unit area is calculated using the average cross-sectional area calculated using the particle size of the spherical particle, and this is compressed. Strength. Further, the compression rate is calculated from the compression displacement and the particle size of the spherical particles, and the relationship between the compression strength and the compression rate is obtained. The spherical particles to be measured are measured by observing the spherical particles using a microscope, and selecting spherical particles having an average particle size of ± 10%. The compressive strength is calculated as an average compressive strength obtained by averaging 20 measurement results. As the micro compression tester, for example, “Micro compression tester HM2000” manufactured by Fischer Instruments is used. In particular, the compression strength at 30% compression means the average compression strength at a compression rate of 30%. The compression ratio can be calculated by (compression ratio = compression displacement / average particle diameter × 100).

  The spherical particles are preferably resin particles from the viewpoint of more effectively increasing the insulating properties. Various organic materials are suitably used as the resin for forming the resin particles. Examples of the resin for forming the resin particles include polyolefin resins such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyisobutylene, and polybutadiene; acrylic resins such as polymethyl methacrylate and polymethyl acrylate; polycarbonate , Polyamide, phenol formaldehyde resin, melamine formaldehyde resin, benzoguanamine formaldehyde resin, urea formaldehyde resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, epoxy resin, unsaturated polyester resin, saturated polyester resin, polyethylene terephthalate, polysulfone, polyphenylene oxide , Polyacetal, polyimide, polyamideimide, polyether ether Tons, polyether sulfone, divinyl benzene polymer, and divinylbenzene copolymer, and the like. Examples of the divinylbenzene copolymer include divinylbenzene-styrene copolymer and divinylbenzene- (meth) acrylic acid ester copolymer. Since the hardness of the resin particles can be easily controlled within a suitable range, the resin for forming the resin particles is a polymer obtained by polymerizing one or more polymerizable monomers having an ethylenically unsaturated group. It is preferably a coalescence.

  When the resin particles are obtained by polymerizing a polymerizable monomer having an ethylenically unsaturated group, the polymerizable monomer having an ethylenically unsaturated group may be a non-crosslinkable monomer or a crosslinkable monomer. And the monomer.

  Examples of the non-crosslinkable monomer include styrene monomers such as styrene and α-methylstyrene; carboxyl group-containing monomers such as (meth) acrylic acid, maleic acid, and maleic anhydride; (Meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, cetyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl ( Alkyl (meth) acrylate compounds such as meth) acrylate and isobornyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, glycerol (meth) acrylate, polyoxyethylene (meth) acrylate, glycidyl (meth) acrylate, etc. Elemental-containing (meth) acrylate compounds; Nitrile-containing monomers such as (meth) acrylonitrile; Halogen-containing substances such as trifluoromethyl (meth) acrylate, pentafluoroethyl (meth) acrylate, vinyl chloride, vinyl fluoride, chlorostyrene And monomers.

  Examples of the crosslinkable monomer include tetramethylolmethane tetra (meth) acrylate, tetramethylolmethane tri (meth) acrylate, tetramethylolmethane di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and dipenta Erythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, glycerol tri (meth) acrylate, glycerol di (meth) acrylate, (poly) ethylene glycol di (meth) acrylate, (poly) propylene glycol di (meth) Polyfunctional (meth) acrylate compounds such as acrylate, (poly) tetramethylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate; triallyl (iso) cyanide Silane-containing monomers such as salts, triallyl trimellitate, divinylbenzene, diallyl phthalate, diallylacrylamide, diallyl ether, γ- (meth) acryloxypropyltrimethoxysilane, trimethoxysilylstyrene, vinyltrimethoxysilane, etc. Is mentioned.

  The term “(meth) acrylate” refers to acrylate and methacrylate. The term “(meth) acryl” refers to acrylic and methacrylic. The term “(meth) acryloyl” refers to acryloyl and methacryloyl.

  The resin particles can be obtained by polymerizing the polymerizable monomer having an ethylenically unsaturated group by a known method. Examples of this method include a method of suspension polymerization in the presence of a radical polymerization initiator, and a method of polymerizing by swelling a monomer together with a radical polymerization initiator using non-crosslinked seed particles.

  The spherical particles are not limited to the resin particles. The spherical particles may be inorganic particles, silica or diamond. The inorganic particles preferably have a dielectric constant of 7 or less, more preferably 4 or less.

  Spherical means that the aspect ratio is less than 2. The aspect ratio of the spherical particles is preferably 1.5 or less, more preferably 1.1 or less, from the viewpoint of more effectively increasing the insulating properties and the viewpoint of increasing the thermal conductivity more effectively. . The lower limit of the aspect ratio of the spherical particles is not particularly limited. The aspect ratio of the spherical particles may be 1 or more.

  The aspect ratio of the spherical particles indicates a major axis / minor axis. The aspect ratio of the spherical particles is preferably an average aspect ratio obtained by averaging the aspect ratios of the plurality of spherical particles. The average aspect ratio of the spherical particles is obtained by, for example, observing 50 arbitrarily selected spherical particles with an electron microscope or an optical microscope and calculating an average value of the major axis / minor axis of the spherical particles. It is done.

  From the viewpoint of more effectively increasing the insulation and from the viewpoint of further effectively increasing the thermal conductivity, the average sphericity of the spherical particles is preferably 0.7 or more, more preferably 0.9 or more, More preferably, it is 0.99 or more, Most preferably, it is 0.995 or more. The upper limit of the average sphericity of the spherical particles is not particularly limited. The average sphericity of the spherical particles may be 1 or less.

  The sphericity can be calculated from the area and perimeter of the spherical particles by observing the spherical particles with an electron microscope. The sphericity is closer to a true sphere as it approaches 1. The average sphericity of the spherical particles is preferably calculated by, for example, averaging the sphericity of 50 arbitrarily selected spherical particles.

  From the viewpoint of further effectively increasing the thermal conductivity, the thermal conductivity of the spherical particles is preferably 0.05 W / m · K or more, more preferably 0.2 W / m · K or more. The upper limit of the thermal conductivity of the spherical particles is not particularly limited. The spherical particles may have a thermal conductivity of 1 W / m · K or less.

  In the laminated body which concerns on this invention, content of the said spherical particle is 1 volume% or more and 40 volume% or less in 100 volume% of said insulating layers. From the viewpoint of more effectively increasing the thermal conductivity, the content of the spherical particles in 100% by volume of the insulating layer is preferably 3% by volume or more, more preferably 5% by volume or more, preferably 30%. The volume% or less, more preferably 20 volume% or less. When the content of the spherical particles is not less than the above lower limit and not more than the above upper limit, the thermally conductive filler is disposed along the surface of the spherical particles, so that an effective heat conduction path in the thickness direction can be obtained. It can be formed even more. Further, when the content of the spherical particles is not less than the above lower limit and not more than the above upper limit, in the insulating layer, the spherical particles can further exert a function as a spacer, and the thermally conductive filler Orientation in the plane direction can be further prevented. As a result, thermal conductivity can be more effectively increased not only in the surface direction but also in the thickness direction.

Non-spherical thermally conductive filler:
In the laminate according to the present invention, the insulating layer includes a non-spherical thermally conductive filler. Non-spherical means that the aspect ratio is 2 or more, preferably 3 or more, and more preferably 4 or more. The thermally conductive filler is not the spherical particle. Moreover, the said heat conductive filler may form the aggregated particle. In that case, the aspect ratio of the thermally conductive filler means not the aspect ratio of the aggregated particles (secondary particles) but the aspect ratio of the primary particles constituting the aggregated particles. As for the said heat conductive filler, only 1 type may be used and 2 or more types may be used together.

  From the viewpoint of more effectively increasing the insulating properties and from the viewpoint of more effectively increasing the thermal conductivity, the aspect ratio of the thermal conductive filler is preferably 3 or more, more preferably 4 or more. The upper limit of the aspect ratio of the heat conductive filler is not particularly limited. The aspect ratio of the heat conductive filler may be 20 or less.

  The aspect ratio of the heat conductive filler indicates a major axis / minor axis. The aspect ratio of the thermally conductive filler is preferably an average aspect ratio obtained by averaging the aspect ratios of the plurality of thermally conductive fillers. The average aspect ratio is obtained by measuring the major axis / minor axis of 50 arbitrarily selected thermal conductive fillers from the electron microscope image of the cross section of the insulating layer and calculating the average value.

  From the viewpoint of more effectively increasing the thermal conductivity, the thermal conductivity of the thermal conductive filler is preferably 5 W / m · K or more, more preferably 10 W / m · K or more. The upper limit of the thermal conductivity of the thermal conductive filler is not particularly limited. The thermal conductivity of the thermal conductive filler may be 1000 W / m · K or less.

  The material of the said heat conductive filler is not specifically limited. From the viewpoint of more effectively increasing the thermal conductivity, the material of the thermal conductive filler is preferably boron nitride, boron nitride nanotubes, aluminum nitride, or diamond, and particularly preferably boron nitride.

  The boron nitride is not particularly limited. Examples of the boron nitride include hexagonal boron nitride, cubic boron nitride, boron nitride prepared by a reduction nitriding method of a boron compound and ammonia, boron nitride prepared from a boron compound and a nitrogen-containing compound such as melamine, and the like. And boron nitride prepared from sodium borohydride and ammonium chloride.

  From the viewpoint of further effectively increasing the thermal conductivity, the particle size of the thermal conductive filler is preferably 3 μm or more, more preferably 4 μm or more, preferably 20 μm or less, more preferably 10 μm or less. The particle diameter of the heat conductive filler means a major axis. When the particle diameter of the thermally conductive filler is not less than the lower limit and not more than the upper limit, the thermally conductive filler is disposed along the surface of the spherical particles, so that effective heat conduction in the thickness direction is achieved. More passes can be formed.

  The particle diameter of the heat conductive filler is preferably an average particle diameter obtained by averaging the particle diameters of the plurality of heat conductive fillers. The particle size of the thermally conductive filler is obtained by measuring the particle size of 50 arbitrarily selected thermal conductive fillers from the electron microscope image of the cross section of the insulating layer and calculating the average value. .

  From the viewpoint of more effectively increasing the insulating property and from the viewpoint of increasing the thermal conductivity more effectively, it is preferable that the heat conductive filler includes an aggregate of non-spherical heat conductive filler. It is preferable that the said insulating layer contains the aggregate of a non-spherical heat conductive filler. When the insulating layer contains an agglomerate of non-spherical heat conductive filler, and the compressive force is applied to the insulating layer by a press or the like for molding of a laminate, the agglomerate Is appropriately deformed or collapsed, it is possible to fill the voids existing between the spherical particles, and to effectively improve the insulation. Furthermore, by arranging the aggregates that have been appropriately deformed or collapsed along the surface of the spherical particles, an effective heat conduction path in the thickness direction can be further formed.

  From the viewpoint of more effectively increasing the insulating property and from the viewpoint of increasing the thermal conductivity more effectively, the aggregate is composed of boron nitride aggregated particles, boron nitride nanotube aggregates, aluminum nitride aggregated particles, or diamond aggregates. Particles are preferable, and boron nitride aggregated particles are particularly preferable.

  From the viewpoint of more effectively increasing the insulating properties and from the viewpoint of increasing the thermal conductivity more effectively, the aggregate is composed of aggregates of primary particles of boron nitride, aggregates of boron nitride nanotubes, and aluminum nitride. Aggregates or aggregates of diamond particles are preferred, and aggregates of primary particles of boron nitride are particularly preferred.

  The method for producing the boron nitride aggregated particles is not particularly limited. Examples of the method for producing the boron nitride aggregated particles include a spray drying method and a fluidized bed granulation method. The method for producing the boron nitride aggregated particles is preferably a spray drying (also called spray drying) method. The spray drying method can be classified into a two-fluid nozzle method, a disk method (also called a rotary method), an ultrasonic nozzle method, and the like depending on the spray method, and any of these methods can be applied. From the viewpoint of more easily controlling the total pore volume, the ultrasonic nozzle method is preferable.

  Moreover, as a manufacturing method of boron nitride aggregated particles, a granulation step is not necessarily required. It may be boron nitride aggregated particles formed by spontaneously concentrating boron nitride primary particles as the boron nitride crystal grows. Moreover, in order to make the particle diameter of boron nitride aggregated particles uniform, pulverized boron nitride aggregated particles may be used.

  The boron nitride agglomerated particles are preferably manufactured using primary particles of boron nitride as a material. It does not specifically limit as a boron nitride used as the material of the said boron nitride aggregate particle, The boron nitride mentioned above is mentioned. From the viewpoint of further effectively increasing the thermal conductivity of the boron nitride aggregated particles, the boron nitride used as the material for the boron nitride aggregated particles is preferably hexagonal boron nitride.

  From the viewpoint of more effectively increasing the thermal conductivity, the particle size of the aggregate is preferably 20 μm or more, more preferably 40 μm or more, preferably 200 μm or less, more preferably 150 μm or less.

  The particle diameter of the aggregate is preferably an average particle diameter obtained by averaging the particle diameters on a volume basis. The particle diameter of the aggregate can be measured using a “laser diffraction particle size distribution analyzer” manufactured by Horiba, Ltd. It is preferable to adopt the particle diameter (d50) of the aggregate when the cumulative volume of the aggregate is 50% as the average particle diameter. The average particle diameter of the aggregate can be calculated, for example, by averaging the particle diameters of 50 arbitrarily selected aggregates.

  The aspect ratio of the aggregate is preferably 4 or less, more preferably 2 or less, from the viewpoint of more effectively increasing the insulating property and the viewpoint of further effectively increasing the thermal conductivity. The lower limit of the aspect ratio of the aggregate is not particularly limited. The aspect ratio of the aggregate may be 1 or more.

  The aspect ratio of the aggregate indicates a major axis / minor axis. The aspect ratio of the aggregate is preferably an average aspect ratio obtained by averaging the aspect ratios of the plurality of aggregates. The average aspect ratio of the aggregate is obtained by, for example, observing 50 arbitrarily selected aggregates with an electron microscope or an optical microscope, and calculating an average value of major axis / minor axis of the aggregate. It is done.

  From the viewpoint of more effectively increasing the thermal conductivity, the thermal conductivity of the aggregate is preferably 5 W / m · K or more, more preferably 10 W / m · K or more. The upper limit of the thermal conductivity of the aggregate is not particularly limited. The thermal conductivity of the aggregate may be 1000 W / m · K or less.

  From the viewpoint of increasing the thermal conductivity more effectively, the content of the thermal conductive filler in the insulating layer 100% by volume is preferably 45% by volume or more, more preferably 50% by volume or more, and still more preferably. It is 55 volume% or more, preferably 85 volume% or less, more preferably 70 volume% or less, and still more preferably 65 volume% or less.

  From the viewpoint of more effectively increasing the thermal conductivity, the content of the aggregate in the insulating layer 100% by volume is preferably 45% by volume or more, more preferably 50% by volume or more, and further preferably 55% by volume. % Or more, preferably 85% by volume or less, more preferably 70% by volume or less, and still more preferably 65% by volume or less.

  From the viewpoint of increasing the thermal conductivity more effectively, the total content of the thermal conductive filler and the spherical particles in 100% by volume of the insulating layer is preferably 46% by volume or more, more preferably 60%. It is at least volume%, preferably at most 90 volume%, more preferably at most 80 volume%.

  From the viewpoint of more effectively increasing the thermal conductivity, the thermal conductive filler may be composed of two or more types of thermal conductive fillers having different aspect ratios as long as the aspect ratio is in the range described above. .

  From the viewpoint of more effectively increasing the thermal conductivity and insulation, the insulating layer is not the spherical particles and the thermally conductive filler, but the third particles that are not the spherical particles and the thermally conductive filler. May be included. That is, in addition to the spherical particles and the heat conductive filler, boron nitride aggregated particles may be included as the third particles. In this case, since the primary particles constituting the boron nitride agglomerated particles as the third particles are non-spherical heat conductive fillers, the heat conductive filler has two or more types of heat conduction having different aspect ratios. This is the case when it is composed of a conductive filler.

binder:
In the laminate according to the present invention, the insulating layer contains a binder. The insulating layer is preferably formed from a resin material containing a binder. The binder is not particularly limited. A known insulating resin is used as the binder. The binder preferably includes a thermoplastic component (thermoplastic compound) or a curable component, and more preferably includes a curable component. Examples of the curable component include a thermosetting component and a photocurable component. The thermosetting component preferably contains a thermosetting compound and a thermosetting agent. It is preferable that the said photocurable component contains a photocurable compound and a photoinitiator. The binder preferably contains a thermosetting component. As for the said binder, only 1 type may be used and 2 or more types may be used together.

Thermosetting compound:
Examples of the thermosetting compounds include styrene compounds, phenoxy compounds, oxetane compounds, epoxy compounds, episulfide compounds, (meth) acrylic compounds, phenolic compounds, amino compounds, unsaturated polyester compounds, polyurethane compounds, silicone compounds, and polyimide compounds. Can be mentioned. As for the said thermosetting compound, only 1 type may be used and 2 or more types may be used together.

  As the thermosetting compound, (A1) a thermosetting compound having a molecular weight of less than 10,000 (may be simply referred to as (A1) thermosetting compound) may be used. As the thermosetting compound, (A2) a thermosetting compound having a molecular weight of 10,000 or more (simply described as (A2) thermosetting compound) may be used. As said thermosetting compound, you may use both (A1) thermosetting compound and (A2) thermosetting compound.

  The content of the thermosetting compound in 100% by volume of the insulating layer is preferably 10% by volume or more, more preferably 20% by volume or more, preferably 90% by volume or less, more preferably 80% by volume or less. is there. When the content of the thermosetting compound is not less than the above lower limit, the adhesiveness and heat resistance of the cured product are further enhanced. When the content of the thermosetting compound is not more than the above upper limit, the coatability of the resin material (insulating layer forming material) is further enhanced.

(A1) Thermosetting compound having a molecular weight of less than 10,000:
(A1) As a thermosetting compound, the thermosetting compound which has a cyclic ether group is mentioned. Examples of the cyclic ether group include an epoxy group and an oxetanyl group. The thermosetting compound having a cyclic ether group is preferably a thermosetting compound having an epoxy group or an oxetanyl group. (A1) As for a thermosetting compound, only 1 type may be used and 2 or more types may be used together.

  The (A1) thermosetting compound may contain (A1a) a thermosetting compound having an epoxy group (sometimes simply referred to as (A1a) a thermosetting compound), and (A1b) an oxetanyl group. A thermosetting compound (which may be simply referred to as (A1b) thermosetting compound).

  From the viewpoint of further effectively increasing the heat resistance and moisture resistance of the cured product, the (A1) thermosetting compound preferably has an aromatic skeleton.

  The aromatic skeleton is not particularly limited. Examples of the aromatic skeleton include naphthalene skeleton, fluorene skeleton, biphenyl skeleton, anthracene skeleton, pyrene skeleton, xanthene skeleton, adamantane skeleton, and bisphenol A skeleton. From the viewpoint of further effectively increasing the cold heat cycle characteristics and heat resistance of the cured product, the aromatic skeleton is preferably a biphenyl skeleton or a fluorene skeleton.

  (A1a) The thermosetting compound includes an epoxy monomer having a bisphenol skeleton, an epoxy monomer having a dicyclopentadiene skeleton, an epoxy monomer having a naphthalene skeleton, an epoxy monomer having an adamantane skeleton, an epoxy monomer having a fluorene skeleton, and a biphenyl skeleton. Epoxy monomers having a bi (glycidyloxyphenyl) methane skeleton, epoxy monomers having a xanthene skeleton, epoxy monomers having an anthracene skeleton, and epoxy monomers having a pyrene skeleton. These hydrogenated products or modified products may be used. (A1a) As for a thermosetting compound, only 1 type may be used and 2 or more types may be used together.

  Examples of the epoxy monomer having a bisphenol skeleton include an epoxy monomer having a bisphenol A type, bisphenol F type, or bisphenol S type bisphenol skeleton.

  Examples of the epoxy monomer having a dicyclopentadiene skeleton include dicyclopentadiene dioxide and a phenol novolac epoxy monomer having a dicyclopentadiene skeleton.

  Examples of the epoxy monomer having a naphthalene skeleton include 1-glycidylnaphthalene, 2-glycidylnaphthalene, 1,2-diglycidylnaphthalene, 1,5-diglycidylnaphthalene, 1,6-diglycidylnaphthalene, 1,7-diglycidyl. Naphthalene, 2,7-diglycidylnaphthalene, triglycidylnaphthalene, 1,2,5,6-tetraglycidylnaphthalene and the like can be mentioned.

  Examples of the epoxy monomer having an adamantane skeleton include 1,3-bis (4-glycidyloxyphenyl) adamantane and 2,2-bis (4-glycidyloxyphenyl) adamantane.

  Examples of the epoxy monomer having a fluorene skeleton include 9,9-bis (4-glycidyloxyphenyl) fluorene, 9,9-bis (4-glycidyloxy-3-methylphenyl) fluorene, and 9,9-bis (4- Glycidyloxy-3-chlorophenyl) fluorene, 9,9-bis (4-glycidyloxy-3-bromophenyl) fluorene, 9,9-bis (4-glycidyloxy-3-fluorophenyl) fluorene, 9,9-bis (4-Glycidyloxy-3-methoxyphenyl) fluorene, 9,9-bis (4-glycidyloxy-3,5-dimethylphenyl) fluorene, 9,9-bis (4-glycidyloxy-3,5-dichlorophenyl) Fluorene and 9,9-bis (4-glycidyloxy-3,5-dibromophenyl) Fluorene, and the like.

  Examples of the epoxy monomer having a biphenyl skeleton include 4,4'-diglycidylbiphenyl and 4,4'-diglycidyl-3,3 ', 5,5'-tetramethylbiphenyl.

  Examples of the epoxy monomer having a bi (glycidyloxyphenyl) methane skeleton include 1,1′-bi (2,7-glycidyloxynaphthyl) methane, 1,8′-bi (2,7-glycidyloxynaphthyl) methane, 1,1′-bi (3,7-glycidyloxynaphthyl) methane, 1,8′-bi (3,7-glycidyloxynaphthyl) methane, 1,1′-bi (3,5-glycidyloxynaphthyl) methane 1,8'-bi (3,5-glycidyloxynaphthyl) methane, 1,2'-bi (2,7-glycidyloxynaphthyl) methane, 1,2'-bi (3,7-glycidyloxynaphthyl) Examples include methane and 1,2′-bi (3,5-glycidyloxynaphthyl) methane.

  Examples of the epoxy monomer having a xanthene skeleton include 1,3,4,5,6,8-hexamethyl-2,7-bis-oxiranylmethoxy-9-phenyl-9H-xanthene.

  Specific examples of the (A1b) thermosetting compound include, for example, 4,4′-bis [(3-ethyl-3-oxetanyl) methoxymethyl] biphenyl, 1,4-benzenedicarboxylic acid bis [(3-ethyl- 3-oxetanyl) methyl] ester, 1,4-bis [(3-ethyl-3-oxetanyl) methoxymethyl] benzene, oxetane-modified phenol novolak, and the like. (A1b) Only 1 type may be used for a thermosetting compound and 2 or more types may be used together.

  From the viewpoint of further improving the heat resistance of the cured product, the (A1) thermosetting compound preferably includes a thermosetting compound having two or more cyclic ether groups.

  From the viewpoint of further improving the heat resistance of the cured product, the content of the thermosetting compound having two or more cyclic ether groups is preferably 70% by weight or more in 100% by weight of the (A1) thermosetting compound. More preferably, it is 80% by weight or more, and preferably 100% by weight or less. (A1) The content of the thermosetting compound having two or more cyclic ether groups in 100% by weight of the thermosetting compound may be 10% by weight or more and 100% by weight or less. Further, the whole (A1) thermosetting compound may be a thermosetting compound having two or more cyclic ether groups.

  (A1) The molecular weight of the thermosetting compound is less than 10,000. (A1) The molecular weight of the thermosetting compound is preferably 200 or more, preferably 1200 or less, more preferably 600 or less, and even more preferably 550 or less. (A1) When the molecular weight of the thermosetting compound is not less than the above lower limit, the adhesiveness of the surface of the cured product is lowered, and the handleability of the resin material is further enhanced. (A1) When the molecular weight of the thermosetting compound is not more than the above upper limit, the adhesiveness of the cured product is further enhanced. Furthermore, the cured product is hard and hard to be brittle, and the adhesiveness of the cured product is further enhanced.

  In this specification, (A1) the molecular weight of the thermosetting compound is (A1) when the thermosetting compound is not a polymer, and (A1) when the structural formula of the thermosetting compound can be specified. It means the molecular weight that can be calculated from the structural formula. When the thermosetting compound (A1) is a polymer, it means the weight average molecular weight. The weight average molecular weight is a weight average molecular weight in terms of polystyrene measured by gel permeation chromatography (GPC).

  In 100% by volume of the insulating layer, the content of the (A1) thermosetting compound is preferably 10% by volume or more, more preferably 20% by volume or more, preferably 90% by volume or less, more preferably 80% by volume. It is as follows. (A1) When the content of the thermosetting compound is not less than the above lower limit, the adhesiveness and heat resistance of the cured product are further enhanced. (A1) When the content of the thermosetting compound is not more than the above upper limit, the coating property of the resin material is further enhanced.

(A2) Thermosetting compound having a molecular weight of 10,000 or more:
(A2) The thermosetting compound is a thermosetting compound having a molecular weight of 10,000 or more. Since the molecular weight of the (A2) thermosetting compound is 10,000 or more, the (A2) thermosetting compound is generally a polymer, and the above molecular weight generally means a weight average molecular weight.

  From the viewpoint of further effectively increasing the heat resistance and moisture resistance of the cured product, the (A2) thermosetting compound preferably has an aromatic skeleton. (A2) When the thermosetting compound is a polymer and (A2) the thermosetting compound has an aromatic skeleton, (A2) the thermosetting compound has an aromatic skeleton in any part of the whole polymer. What is necessary is just to have, it may have in the main chain frame | skeleton, and you may have in a side chain. From the viewpoint of further increasing the heat resistance of the cured product and further increasing the moisture resistance of the cured product, the (A2) thermosetting compound preferably has an aromatic skeleton in the main chain skeleton. (A2) As for a thermosetting compound, only 1 type may be used and 2 or more types may be used together.

  The aromatic skeleton is not particularly limited. Examples of the aromatic skeleton include naphthalene skeleton, fluorene skeleton, biphenyl skeleton, anthracene skeleton, pyrene skeleton, xanthene skeleton, adamantane skeleton, and bisphenol A skeleton. From the viewpoint of further effectively increasing the cold heat cycle characteristics and heat resistance of the cured product, the aromatic skeleton is preferably a biphenyl skeleton or a fluorene skeleton.

  (A2) The thermosetting compound is not particularly limited. (A2) Thermosetting compounds include styrene resins, phenoxy resins, oxetane resins, epoxy resins, episulfide compounds, (meth) acrylic resins, phenol resins, amino resins, unsaturated polyester resins, polyurethane resins, silicone resins and polyimide resins. Etc.

  From the viewpoint of suppressing the oxidative deterioration of the cured product, further improving the heat cycle resistance and heat resistance of the cured product, and further reducing the water absorption of the cured product, (A2) the thermosetting compound is a styrene resin, It is preferably a phenoxy resin or an epoxy resin, more preferably a phenoxy resin or an epoxy resin, and further preferably a phenoxy resin. In particular, use of a phenoxy resin or an epoxy resin further increases the heat resistance of the cured product. Moreover, use of a phenoxy resin further lowers the elastic modulus of the cured product and further improves the cold-heat cycle characteristics of the cured product. In addition, the (A2) thermosetting compound does not need to have cyclic ether groups, such as an epoxy group.

  As the styrene resin, specifically, a homopolymer of a styrene monomer, a copolymer of a styrene monomer and an acrylic monomer, or the like can be used. Styrene polymers having a styrene-glycidyl methacrylate structure are preferred.

  Examples of the styrene monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, p-ethylstyrene, and pn-. Butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, 2,4-dimethyl Examples include styrene and 3,4-dichlorostyrene.

  Specifically, the phenoxy resin is, for example, a resin obtained by reacting an epihalohydrin with a divalent phenol compound, or a resin obtained by reacting a divalent epoxy compound with a divalent phenol compound.

  The phenoxy resin has a bisphenol A skeleton, bisphenol F skeleton, bisphenol A / F mixed skeleton, naphthalene skeleton, fluorene skeleton, biphenyl skeleton, anthracene skeleton, pyrene skeleton, xanthene skeleton, adamantane skeleton or dicyclopentadiene skeleton. It is preferable. More preferably, the phenoxy resin has a bisphenol A skeleton, a bisphenol F skeleton, a bisphenol A / F mixed skeleton, a naphthalene skeleton, a fluorene skeleton, or a biphenyl skeleton, and at least one of the fluorene skeleton and the biphenyl skeleton. More preferably, it has a skeleton. Use of the phenoxy resin having these preferable skeletons further increases the heat resistance of the cured product.

  The epoxy resin is an epoxy resin other than the phenoxy resin. Examples of the epoxy resins include styrene skeleton-containing epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, phenol novolac type epoxy resins, biphenol type epoxy resins, naphthalene type epoxy resins, and fluorene type epoxy resins. , Phenol aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, dicyclopentadiene type epoxy resin, anthracene type epoxy resin, epoxy resin having adamantane skeleton, epoxy resin having tricyclodecane skeleton, and epoxy resin having triazine nucleus in skeleton Etc.

  (A2) The molecular weight of the thermosetting compound is 10,000 or more. (A2) The molecular weight of the thermosetting compound is preferably 30000 or more, more preferably 40000 or more, preferably 1000000 or less, more preferably 250,000 or less. (A2) When the molecular weight of the thermosetting compound is not less than the above lower limit, the cured product is hardly thermally deteriorated. When the molecular weight of the (A2) thermosetting compound is not more than the above upper limit, the compatibility between the (A2) thermosetting compound and other components is increased. As a result, the heat resistance of the cured product is further increased.

  In 100% by volume of the insulating layer, the content of the (A2) thermosetting compound is preferably 20% by volume or more, more preferably 30% by volume or more, preferably 60% by volume or less, more preferably 50% by volume. It is as follows. (A2) When the content of the thermosetting compound is not less than the above lower limit, the handleability of the resin material is further improved. (A2) When the content of the thermosetting compound is not more than the above upper limit, the coating property of the resin material is further enhanced.

Thermosetting agent:
The thermosetting agent is not particularly limited. As the thermosetting agent, a thermosetting agent capable of curing the thermosetting compound can be appropriately used. In the present specification, the thermosetting agent includes a curing catalyst. As for a thermosetting agent, only 1 type may be used and 2 or more types may be used together.

  From the viewpoint of further effectively increasing the heat resistance of the cured product, the thermosetting agent preferably has an aromatic skeleton or an alicyclic skeleton. The thermosetting agent preferably includes an amine curing agent (amine compound), an imidazole curing agent, a phenol curing agent (phenol compound), or an acid anhydride curing agent (acid anhydride), and more preferably includes an amine curing agent. preferable. The acid anhydride curing agent includes an acid anhydride having an aromatic skeleton, a water additive of the acid anhydride or a modified product of the acid anhydride, or an acid anhydride having an alicyclic skeleton, It is preferable to include a water additive of an acid anhydride or a modified product of the acid anhydride.

  Examples of the amine curing agent include dicyandiamide, imidazole compounds, diaminodiphenylmethane, and diaminodiphenylsulfone. From the viewpoint of more effectively increasing the adhesiveness of the cured product, the amine curing agent is more preferably dicyandiamide or an imidazole compound. From the viewpoint of more effectively increasing the storage stability of the resin material, the thermosetting agent preferably includes a curing agent having a melting point of 180 ° C. or higher, and includes an amine curing agent having a melting point of 180 ° C. or higher. Is more preferable.

  Examples of the imidazole curing agent include 2-undecylimidazole, 2-heptadecylimidazole, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 1-benzyl. 2-methylimidazole, 1-benzyl-2-phenylimidazole, 1,2-dimethylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2- Undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6- [2 '-Methyl Midazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-undecylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6 [2′-Ethyl-4′-methylimidazolyl- (1 ′)]-ethyl-s-triazine, 2,4-diamino-6- [2′-methylimidazolyl- (1 ′)]-ethyl-s-triazine Isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-methylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole and 2-phenyl-4-methyl-5-dihydroxymethylimidazole Can be mentioned.

  Examples of the phenol curing agent include phenol novolak, o-cresol novolak, p-cresol novolak, t-butylphenol novolak, dicyclopentadiene cresol, polyparavinylphenol, bisphenol A type novolak, xylylene modified novolak, decalin modified novolak, poly ( And di-o-hydroxyphenyl) methane, poly (di-m-hydroxyphenyl) methane, and poly (di-p-hydroxyphenyl) methane. From the viewpoint of further effectively increasing the flexibility of the cured product and the flame retardancy of the cured product, the phenol curing agent is a phenol resin having a melamine skeleton, a phenol resin having a triazine skeleton, or a phenol resin having an allyl group. It is preferable that

  Commercially available products of the phenol curing agent include MEH-8005, MEH-8010, and MEH-8015 (all of which are manufactured by Meiwa Kasei Co., Ltd.), YLH903 (manufactured by Mitsubishi Chemical Corporation), LA-7052, LA-7054, and LA-7751. LA-1356 and LA-3018-50P (all of which are manufactured by DIC Corporation), PS6313 and PS6492 (all of which are manufactured by Gunei Chemical Co., Ltd.), and the like.

  Examples of the acid anhydride having an aromatic skeleton, a water additive of the acid anhydride, or a modified product of the acid anhydride include, for example, a styrene / maleic anhydride copolymer, a benzophenone tetracarboxylic acid anhydride, and a pyromellitic acid anhydride. , Trimellitic anhydride, 4,4'-oxydiphthalic anhydride, phenylethynyl phthalic anhydride, glycerol bis (anhydrotrimellitate) monoacetate, ethylene glycol bis (anhydrotrimellitate), methyltetrahydroanhydride Examples include phthalic acid, methylhexahydrophthalic anhydride, and trialkyltetrahydrophthalic anhydride.

  Examples of commercially available acid anhydrides having an aromatic skeleton, water additives of the acid anhydrides, or modified products of the acid anhydrides include SMA Resin EF30, SMA Resin EF40, SMA Resin EF60, and SMA Resin EF80 (any of the above Also manufactured by Sartomer Japan), ODPA-M and PEPA (all manufactured by Manac), Ricacid MTA-10, Ricacid MTA-15, Ricacid TMTA, Ricacid TMEG-100, Ricacid TMEG-200, Ricacid TMEG-300, Ricacid TMEG-500, Ricacid TMEG-S, Ricacid TH, Ricacid HT-1A, Ricacid HH, Ricacid MH-700, Ricacid MT-500, Ricacid DSDA and Ricacid TDA-100 (all of which are manufactured by Shin Nippon Rika Co., Ltd.) PICLON B4400, EPICLON B650, and EPICLON B570 (all manufactured by both DIC Corporation).

  The acid anhydride having an alicyclic skeleton, a water additive of the acid anhydride, or a modified product of the acid anhydride is an acid anhydride having a polyalicyclic skeleton, a water additive of the acid anhydride, or the A modified product of an acid anhydride, or an acid anhydride having an alicyclic skeleton obtained by addition reaction of a terpene compound and maleic anhydride, a water additive of the acid anhydride, or a modified product of the acid anhydride It is preferable. By using these curing agents, the flexibility of the cured product and the moisture resistance and adhesion of the cured product are further increased.

  Examples of the acid anhydride having an alicyclic skeleton, a water addition of the acid anhydride, or a modified product of the acid anhydride include methyl nadic acid anhydride, acid anhydride having a dicyclopentadiene skeleton, and the acid anhydride And the like.

  Examples of commercially available acid anhydrides having the alicyclic skeleton, water additions of the acid anhydrides, or modified products of the acid anhydrides include Ricacid HNA and Ricacid HNA-100 (all of which are manufactured by Shin Nippon Rika Co., Ltd.) , And EpiCure YH306, EpiCure YH307, EpiCure YH308H, EpiCure YH309 (all of which are manufactured by Mitsubishi Chemical Corporation) and the like.

  It is also preferable that the thermosetting agent is methyl nadic anhydride or trialkyltetrahydrophthalic anhydride. Use of methyl nadic anhydride or trialkyltetrahydrophthalic anhydride increases the water resistance of the cured product.

  The content of the thermosetting agent in 100% by volume of the insulating layer is preferably 0.1% by volume or more, more preferably 1% by volume or more, preferably 40% by volume or less, more preferably 25% by volume or less. It is. When the content of the thermosetting agent is equal to or higher than the lower limit, it becomes much easier to sufficiently cure the thermosetting compound. When the content of the thermosetting agent is not more than the above upper limit, it is difficult to generate an excessive thermosetting agent that does not participate in curing. For this reason, the heat resistance and adhesiveness of hardened | cured material become still higher.

Photocurable compound:
The said photocurable compound will not be specifically limited if it has photocurability. As for the said photocurable compound, only 1 type may be used and 2 or more types may be used together.

  The photocurable compound preferably has two or more ethylenically unsaturated bonds.

  Examples of the group containing an ethylenically unsaturated bond include a vinyl group, an allyl group, and a (meth) acryloyl group. A (meth) acryloyl group is preferred from the viewpoint of effectively advancing the reaction and further suppressing foaming, peeling and discoloration of the cured product. The photocurable compound preferably has a (meth) acryloyl group.

  From the viewpoint of further effectively increasing the adhesiveness of the cured product, the photocurable compound preferably contains epoxy (meth) acrylate. From the viewpoint of further effectively increasing the heat resistance of the cured product, the epoxy (meth) acrylate preferably contains a bifunctional epoxy (meth) acrylate and a trifunctional or higher functional epoxy (meth) acrylate. The bifunctional epoxy (meth) acrylate preferably has two (meth) acryloyl groups. The tri- or higher functional epoxy (meth) acrylate preferably has three or more (meth) acryloyl groups.

  Epoxy (meth) acrylate is obtained by reacting (meth) acrylic acid with an epoxy compound. Epoxy (meth) acrylate can be obtained by converting an epoxy group into a (meth) acryloyl group. Since the photocurable compound is cured by light irradiation, the epoxy (meth) acrylate preferably has no epoxy group.

  As the epoxy (meth) acrylate, bisphenol type epoxy (meth) acrylate (for example, bisphenol A type epoxy (meth) acrylate, bisphenol F type epoxy (meth) acrylate, bisphenol S type epoxy (meth) acrylate), cresol novolac type Examples include epoxy (meth) acrylate, amine-modified bisphenol-type epoxy (meth) acrylate, caprolactone-modified bisphenol-type epoxy (meth) acrylate, carboxylic acid anhydride-modified epoxy (meth) acrylate, and phenol novolac-type epoxy (meth) acrylate. .

  In 100% by volume of the insulating layer, the content of the photocurable compound is preferably 5% by volume or more, more preferably 10% by volume or more, preferably 40% by volume or less, more preferably 30% by volume or less. is there. Adhesiveness of hardened | cured material becomes still higher that content of these photocurable compounds is more than the said minimum and below the said upper limit.

Photopolymerization initiator:
The photopolymerization initiator is not particularly limited. As said photoinitiator, the photoinitiator which can harden the said photocurable compound by irradiation of light can be used suitably. As for the said photoinitiator, only 1 type may be used and 2 or more types may be used together.

  Examples of the photopolymerization initiator include acylphosphine oxide, halomethylated triazine, halomethylated oxadiazole, imidazole, benzoin, benzoin alkyl ether, anthraquinone, benzanthrone, benzophenone, acetophenone, thioxanthone, benzoate, acridine, phenazine, Examples include titanocene, α-aminoalkylphenone, oxime, and derivatives thereof.

  Examples of the benzophenone photopolymerization initiator include methyl o-benzoylbenzoate and Michler's ketone. EAB (made by Hodogaya Chemical Co., Ltd.) etc. are mentioned as a commercial item of a benzophenone series photoinitiator.

  Examples of commercially available acetophenone photopolymerization initiators include Darocur 1173, Darocur 2959, Irgacure 184, Irgacure 907, and Irgacure 369 (all of which are manufactured by BASF).

  Examples of commercially available benzoin photopolymerization initiators include Irgacure 651 (manufactured by BASF).

  Examples of commercially available acylphosphine oxide photopolymerization initiators include Lucirin TPO (BASF) and Irgacure 819 (BASF).

  Examples of commercially available thioxanthone photopolymerization initiators include isopropyl thioxanthone and diethyl thioxanthone.

  Examples of commercially available oxime photopolymerization initiators include Irgacure OXE-01 and Irgacure OXE-02 (all of which are manufactured by BASF).

  The content of the photopolymerization initiator with respect to 100 parts by weight of the photocurable compound is preferably 1 part by weight or more, more preferably 3 parts by weight or more, preferably 20 parts by weight or less, more preferably 15 parts by weight. Less than parts by weight. When the content of the photopolymerization initiator is not less than the above lower limit and not more than the above upper limit, the photocurable compound can be favorably photocured.

Spherical thermal conductive filler:
In the laminate according to the present invention, the insulating layer may contain a spherical heat conductive filler. The spherical heat conductive filler is not the spherical particles and is not the heat conductive filler. The spherical heat conductive filler may have insulating properties. The spherical heat conductive filler may be an inorganic filler. The spherical thermally conductive filler is preferably not an aggregate of particles. As for the said spherical heat conductive filler, only 1 type may be used and 2 or more types may be used together.

  From the viewpoint of more effectively increasing the thermal conductivity, the spherical thermal conductive filler is preferably an inorganic filler. From the viewpoint of more effectively increasing the thermal conductivity, the spherical thermal conductive filler preferably has a thermal conductivity of 10 W / m · K or more.

  From the viewpoint of further effectively increasing the thermal conductivity of the cured product, the thermal conductivity of the spherical thermal conductive filler is preferably 10 W / m · K or more, more preferably 20 W / m · K or more. . The upper limit of the thermal conductivity of the spherical heat conductive filler is not particularly limited. Inorganic fillers having a thermal conductivity of about 300 W / m · K are widely known, and inorganic fillers having a thermal conductivity of about 200 W / m · K are easily available.

  The material of the spherical heat conductive filler is not particularly limited. The material of the spherical heat conductive filler includes nitrogen compounds (boron nitride, aluminum nitride, silicon nitride, carbon nitride, titanium nitride, etc.), carbon compounds (silicon carbide, fluorine carbide, boron carbide, titanium carbide, tungsten carbide, And diamond), and metal oxides (silica, alumina, zinc oxide, magnesium oxide, beryllium oxide, and the like). The material of the spherical heat conductive filler is preferably the nitrogen compound, the carbon compound, or the metal oxide, and is alumina, boron nitride, aluminum nitride, silicon nitride, silicon carbide, zinc oxide, or magnesium oxide. It is more preferable. Use of these preferable spherical heat conductive fillers further increases the heat conductivity of the cured product.

  The spherical heat conductive filler is preferably spherical particles or particles having an aspect ratio of less than 2. Use of these spherical heat conductive fillers further increases the heat conductivity of the cured product. The spherical particles have an aspect ratio of less than 2.

  The new Mohs hardness of the spherical heat conductive filler material is preferably 12 or less, more preferably 9 or less. When the new Mohs hardness of the spherical heat conductive filler material is 9 or less, the workability of the cured product is further enhanced.

  From the viewpoint of further effectively improving the workability of the cured product, the material of the spherical heat conductive filler is preferably boron nitride, synthetic magnesite, crystalline silica, zinc oxide, or magnesium oxide. The new Mohs hardness of these inorganic filler materials is 9 or less.

  From the viewpoint of increasing the thermal conductivity more effectively, the particle diameter of the spherical thermal conductive filler is preferably 0.1 μm or more, and preferably 20 μm or less. When the particle diameter of the spherical heat conductive filler is not less than the above lower limit, the spherical heat conductive filler can be easily filled at a high density. When the particle diameter of the spherical heat conductive filler is not more than the above upper limit, the heat conductivity of the cured product is further increased.

  The particle diameter is preferably an average particle diameter obtained by averaging the particle diameters on a volume basis measured by a laser diffraction particle size distribution analyzer. The average particle diameter of the spherical heat conductive filler is obtained, for example, by averaging and calculating the particle diameters of 50 arbitrarily selected spherical heat conductive fillers. The average particle diameter of the spherical heat conductive filler can be measured using, for example, a “laser diffraction particle size distribution measuring apparatus” manufactured by Horiba, Ltd.

  From the viewpoint of more effectively increasing the thermal conductivity, the content of the spherical thermal conductive filler in the insulating layer 100% by volume is preferably 1% by volume or more, more preferably 3% by volume or more. , Preferably 20% by volume or less, more preferably 10% by volume or less.

Other ingredients:
In addition to the components described above, the insulating layer may contain other components that are generally used for thermal conductive sheets such as dispersants, chelating agents, antioxidants, and laminates.

(Thermal conductor)
The thermal conductivity of the thermal conductor is preferably 10 W / m · K or more. An appropriate heat conductor can be used as the heat conductor. The heat conductor is preferably a metal material. Examples of the metal material include a metal foil and a metal plate. The heat conductor is preferably the metal foil or the metal plate, and more preferably the metal plate.

  Examples of the metal material include aluminum, copper, gold, silver, and a graphite sheet. From the viewpoint of more effectively increasing the thermal conductivity, the metal material is preferably aluminum, copper, or gold, and more preferably aluminum or copper.

(Conductive layer)
The metal for forming the conductive layer is not particularly limited. Examples of the metal include gold, silver, palladium, copper, platinum, zinc, iron, tin, lead, aluminum, cobalt, indium, nickel, chromium, titanium, antimony, bismuth, thallium, germanium, cadmium, silicon, and tungsten. , Molybdenum, and alloys thereof. Examples of the metal include tin-doped indium oxide (ITO) and solder. From the viewpoint of more effectively increasing the thermal conductivity, aluminum, copper or gold is preferable, and aluminum or copper is more preferable.

  The method for forming the conductive layer is not particularly limited. Examples of the method for forming the conductive layer include a method by electroless plating, a method by electroplating, and a method in which the insulating layer and the metal foil are thermocompression bonded. Since the formation of the conductive layer is simple, a method of thermocompression bonding the insulating layer and the metal foil is preferable.

  FIG. 1 is a cross-sectional view schematically showing a laminate according to an embodiment of the present invention. In FIG. 1, the actual size and thickness are different for convenience of illustration.

  A laminated body 1 shown in FIG. 1 includes a heat conductor 2, an insulating layer 3, and a conductive layer 4. The heat conductor 2, the insulating layer 3, and the conductive layer 4 are the above-described heat conductor, insulating layer, and conductive layer.

  The heat conductor 2 has one surface 2a (first surface) and the other surface 2b (second surface). The insulating layer 3 has one surface 3a (first surface) and the other surface 3b (second surface). The conductive layer 4 has one surface 4a (first surface) and the other surface 4b (second surface).

  A conductive layer 4 is laminated on one surface 3 a (first surface) side of the insulating layer 3. On the other surface 3b (second surface) side of the insulating layer 3, the heat conductor 2 is laminated. The insulating layer 3 is laminated on the other surface 4 b (second surface) side of the conductive layer 4. An insulating layer 3 is laminated on one surface 2 a (first surface) side of the heat conductor 2. An insulating layer 3 is disposed between the heat conductor 2 and the conductive layer 4.

  In the laminate 1 according to this embodiment, the insulating layer 3 includes a cured product portion 11, spherical particles 12 having a dielectric constant of 7 or less, and aspherical heat conductive fillers 13. The spherical particles 12 having a dielectric constant of 7 or less and the non-spherical heat conductive filler 13 are the above-described spherical particles having a dielectric constant of 7 or less and non-spherical heat conductive fillers.

  The spherical particles 12 having a dielectric constant of 7 or less are preferably not excessively deformed by a compression force such as a press. In the cured product portion 11, the spherical particles 12 having a dielectric constant of 7 or less are preferably present in the form of spherical particles. In the cured product portion 11, the spherical particles 12 having a dielectric constant of 7 or less preferably exhibit a function as a spacer.

  The non-spherical heat conductive filler 13 is preferably arranged along the surface of the spherical particles 12 having a dielectric constant of 7 or less. The non-spherical heat conductive filler 13 can form an effective heat conduction path in the thickness direction by being arranged along the surface of the spherical particle 12 having a dielectric constant of 7 or less. As a result, thermal conductivity can be effectively increased not only in the surface direction but also in the thickness direction.

  The non-spherical heat conductive filler 13 may contain aggregates of non-spherical heat conductive fillers. The non-spherical heat conductive filler 13 may include aggregates (secondary particles) deformed by a compression force such as a press, and the aggregates (secondary particles) are collapsed by a compression force such as a press. It may be.

  In the cured product portion 11, the non-spherical heat conductive filler 13 exists between the spherical particles 12 having a dielectric constant of 7 or less. The non-spherical heat conductive filler 13 fills voids existing between the spherical particles 12 having a dielectric constant of 7 or less. The laminated body 1 can fill the voids existing between the spherical particles 12 having a dielectric constant of 7 or less with the non-spherical heat conductive filler 13, and can effectively enhance the insulation.

  In the laminate 1 according to this embodiment, the binder includes a curable component. The cured product portion 11 is a portion where the binder (curable component) is cured. The cured product portion 11 may be a portion where a thermosetting component including a thermosetting compound and a thermosetting agent is cured, or a portion where a photocurable component including a photocurable compound and a photopolymerization initiator is cured. There may be. The hardened | cured material part 11 is obtained by hardening a thermosetting component or a photocurable component.

  The said laminated body can be used for various uses as which heat conductivity, mechanical strength, etc. are calculated | required. For example, in the electronic device, the laminate is used by being disposed between a heat generating component and a heat radiating component. For example, the laminated body is used as a heat radiating body installed between a CPU and fins, or a power card radiating body used in an inverter of an electric vehicle. Further, the laminated body can be used as an insulating circuit substrate by forming a circuit of the conductive layer of the laminated body by a technique such as etching.

  FIG. 2 is a cross-sectional view schematically showing an example of a semiconductor device using the stacked body according to one embodiment of the present invention. In FIG. 2, the actual size and thickness are different for convenience of illustration.

  A semiconductor device 21 shown in FIG. 2 includes a heat conductor 2, an insulating layer 3, and a conductive layer 4. In the semiconductor device 21, the stacked body 1 shown in FIG. 1 is used. 2, the hardened | cured material part 11 contained in the insulating layer 3, the spherical particle 12 with a dielectric constant of 7 or less, and the non-spherical heat conductive filler 13 are abbreviate | omitted for convenience of illustration.

  A semiconductor device 21 shown in FIG. 2 includes a connection conductive portion 5, a semiconductor chip 6, a lead 7, a wire (metal wiring) 8, and a sealing resin 9 in addition to the above configuration. The lead 7 has an electrode.

  The connection conductive portion 5 has one surface 5a (first surface) and the other surface 5b (second surface). The semiconductor chip 6 has one surface 6a (first surface) and the other surface 6b (second surface).

  A semiconductor chip 6 is stacked on one surface 5 a (first surface) side of the connection conductive portion 5. The conductive layer 4 is laminated on the other surface 5b (second surface) side of the connection conductive portion 5. On the other surface 6b (second surface) side of the semiconductor chip 6, the connection conductive portion 5 is laminated. A connection conductive portion 5 is disposed between the semiconductor chip 6 and the conductive layer 4. The semiconductor chip 6 is fixed to the one surface 4 a (first surface) side of the conductive layer 4 by the connection conductive portion 5. The number of the fixed semiconductor chips may be one or two or more. The connection conductive part may be formed of silver paste or may be formed of solder. The conductive layer may be patterned by etching or the like.

  In the semiconductor device 21 according to this embodiment, a circuit pattern (not shown) is formed on one surface 6a (first surface) and the other surface 6b (second surface) of the semiconductor chip 6. The circuit pattern formed on one surface 6 a (first surface) of the semiconductor chip 6 is electrically connected to the electrode of the lead 7 through the wire 8.

  Since the conductive layer 4 is made of metal, it may function as a heat sink. The conductive layer 4 and the heat conductor 2 may be formed of the same material. The conductive layer 4 and the heat conductor 2 may be formed of copper.

  The sealing resin 9 seals the semiconductor chip 6, the connection conductive portion 5, the conductive layer 4, the wire 8, and a part of the lead 7 inside. The lead 7 has a portion protruding from the side surface of the sealing resin 9 to the outside of the sealing resin 9. A sealing resin 9 is laminated on one surface 3 a (first surface) side of the insulating layer 3. The insulating layer 3 and the heat conductor 2 are not sealed with the sealing resin 9 and are exposed to the outside of the sealing resin 9.

  From the viewpoint of increasing the thermal conductivity more effectively, a radiation fin may be provided on the other surface (second surface) side of the thermal conductor.

  Specific examples of the semiconductor device include a semiconductor package. The semiconductor device is not limited to the semiconductor package.

  Hereinafter, the present invention will be clarified by giving specific examples and comparative examples of the present invention. The present invention is not limited to the following examples.

Thermosetting compound:
(1) “Epicoat 828US” manufactured by Mitsubishi Chemical Corporation, epoxy compound

Thermosetting agent:
(1) “Dicyandiamide” manufactured by Tokyo Chemical Industry Co., Ltd.
(2) “2MZA-PW” manufactured by Shikoku Kasei Kogyo Co., Ltd., isocyanuric modified solid dispersion type imidazole

Non-spherical thermally conductive filler:
(1) "PTX25S" manufactured by Momentive (aspect ratio: 14)
(2) “CTS7M” manufactured by Saint-Gobain (aspect ratio: 12)

Spherical particles with a dielectric constant of 7 or less:
(1) "SP-100" manufactured by Sekisui Chemical Co., Ltd.
(2) "SP-120" manufactured by Sekisui Chemical Co., Ltd.
(3) "SP-50" manufactured by Sekisui Chemical Co., Ltd.

Spherical particles with a dielectric constant greater than 7:
(1) "DAM-70" manufactured by Denka

(Particle diameter of spherical particles having a dielectric constant of 7 or less)
The particle diameter of spherical particles having a dielectric constant of 7 or less is calculated by measuring the diameter of the spherical particles having a dielectric constant of 7 or less with a caliper and averaging the diameters of 100 spherical particles having a dielectric constant of 7 or less. did.

(Examples 1-7 and Comparative Examples 1-7)
(1) Preparation of resin material The components shown in Tables 1 and 2 below were blended in the amounts shown in Tables 1 and 2 below, and the resin material was obtained by stirring for 25 minutes at 500 rpm using a planetary stirrer. It was.

(2) Production of Laminate The obtained resin material was coated on a release PET sheet (thickness 50 μm) so as to have a thickness of 270 μm, and dried in an oven at 90 ° C. for 10 minutes to form a curable sheet (insulation) Layer) to form a laminated sheet. Thereafter, the release PET sheet is peeled off, and both sides of the curable sheet (insulating layer) are sandwiched between a copper foil (50 μm) and an aluminum plate (1 mm), at a temperature of 150 ° C., with the pressure shown in Tables 1 and 2 below. A laminate was produced by vacuum pressing under conditions.

(Evaluation)
(1) Thickness of insulating layer The thickness of the insulating layer in the obtained laminate was measured. The thickness of the insulating layer was measured as follows. Further, from the measurement result of the thickness of the insulating layer, the ratio of the particle diameter of spherical particles having a dielectric constant of 7 or less to the thickness of the insulating layer was calculated.

Insulation layer thickness measurement method:
The thickness of the insulating layer was calculated by subtracting the thickness of the copper foil and the aluminum plate from the thickness of the obtained laminate.

(2) Thermal conductivity The obtained laminate was cut into 1 cm square, and then a measurement sample was prepared by spraying carbon black on both sides. Using the obtained measurement sample, thermal conductivity was calculated by a laser flash method. The thermal conductivities in Tables 1 and 2 are relative values with the value of Comparative Example 1 being 1.00.

(3) Dielectric breakdown strength By etching the copper foil in the obtained laminate, the copper foil was patterned into a circle having a diameter of 2 cm to obtain a test sample. An AC voltage was applied at 25 ° C. using a withstand voltage tester (“MODEL7473” manufactured by ETECH Electronics) so that the voltage increased at a rate of 0.33 kV / sec between test samples. The voltage at which a current of 10 mA flowed through the test sample was taken as the breakdown voltage. The dielectric breakdown voltage was normalized by dividing by the sample thickness, and the dielectric breakdown strength was calculated. The dielectric breakdown strength was determined according to the following criteria.

[Criteria for dielectric breakdown strength]
○: 60 kV / mm or more Δ: 30 kV / mm or more, less than 60 kV / mm ×: less than 30 kV / mm

  The results are shown in Tables 1 and 2 below.

DESCRIPTION OF SYMBOLS 1 ... Laminated body 2 ... Thermal conductor 2a ... One surface (1st surface)
2b ... the other surface (second surface)
3 ... Insulating layer 3a ... One surface (first surface)
3b ... the other surface (second surface)
4 ... conductive layer 4a ... one surface (first surface)
4b ... the other surface (second surface)
5: Connection conductive part 5a: One surface (first surface)
5b ... the other surface (second surface)
6 ... Semiconductor chip 6a ... One surface (first surface)
6b ... the other surface (second surface)
7 ... Lead 8 ... Wire (metal wiring)
9 ... Sealing resin 11 ... Hardened material part (part where binder (curable component) is hardened)
12 ... Spherical particles having a dielectric constant of 7 or less 13 ... Non-spherical heat conductive filler 21 ... Semiconductor device

Claims (7)

A heat conductor, an insulating layer laminated on one surface of the heat conductor, and a conductive layer laminated on the surface of the insulating layer opposite to the heat conductor side,
The insulating layer includes a binder, a non-spherical thermally conductive filler, and spherical particles having a dielectric constant of 7 or less;
The ratio of the particle diameter of the spherical particles to the thickness of the insulating layer is 0.7 or more and 0.95 or less,
The laminated body whose content of the said spherical particle is 1 volume% or more and 40 volume% or less in 100 volume% of said insulating layers.   The laminate according to claim 1, wherein a CV value of a particle diameter of the spherical particles is 10% or less.   The laminate according to claim 1 or 2, wherein the thermally conductive filler is boron nitride.   The laminate according to any one of claims 1 to 3, wherein a content of the heat conductive filler is 45% by volume or more and 85% by volume or less in 100% by volume of the insulating layer.   The laminated body of any one of Claims 1-4 containing the aggregate of a non-spherical heat conductive filler as said heat conductive filler.   The total content of the thermally conductive filler and the spherical particles in 100% by volume of the insulating layer is 46% by volume or more and 90% by volume or less, according to any one of claims 1 to 5. Laminated body.   The laminate according to any one of claims 1 to 6, wherein the spherical particles are resin particles.

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