JP5881540B2 - Method for producing thermally conductive insulating sheet - Google Patents

Description

The present invention relates to a thermally conductive insulating substrate used for power electronics, LEDs and the like.

  Conventionally, a semiconductor element called a power semiconductor has been used for transformation and modulation of a power source of an electronic device. In addition, with the demand for miniaturization and higher efficiency of electronic devices, the power density of power devices using power semiconductors has increased exponentially according to the development year. On the other hand, for stable operation and life of the elements, it is necessary to keep the elements below a certain temperature, and how to release the heat generated by these elements is an important issue. Even in such power devices, although the output is particularly high, it is common to use a circuit board in which a metal wiring such as copper is formed on a substrate of insulating ceramics with high thermal conductivity such as aluminum nitride, silicon nitride, alumina, etc. Met.

  However, since a substrate such as aluminum nitride or alumina has brittleness peculiar to ceramics, there may be a problem that the substrate is broken in a screwing process for fixing the substrate to the module, for example. Of course, such a problem does not occur with a resin substrate. However, since resins have low thermal conductivity, attempts have been made to increase the heat dissipation of the substrate by adding thermally conductive ceramics as fillers to various resins. However, when a large amount of heat dissipation is required as in a power device, such a resin substrate has insufficient thermal conductivity. In addition, there is a material in which a resin insulating layer is pasted on a metal substrate such as aluminum, which is usually called a metal base substrate. In this case, the thermal conductivity of the insulating layer is low, and the total thermal conductivity of the metal and insulating layer is low. Is not always enough.

  In order to obtain a substrate with high thermal conductivity, a substrate that has been known as a thermal via for a long time and has a hole in a resin with low thermal conductivity, filled with metal, and the metal penetrates the resin is proposed. (For example, Patent Document 1). However, in this method, for example, in the case of a device with a large area, a large number of vias are required in a large area in order to secure a heat radiation path, which may cause restrictions on circuit design. Further, it has been proposed that a composite material having a high thermal conductivity in the thickness direction is made by impregnating a columnar ceramic grown by CVD on a specific substrate with a resin (for example, Patent Document 2). However, such a method requires very high costs for growing columnar ceramics.

JP 2003-110069 A JP 2008-157555 A

  As described above, there is a need for a heat conductive insulating substrate having a much higher thermal conductivity than conventional resins while overcoming the fragility inherent in ceramics as a heat dissipation substrate for power devices.

  The inventors of the present invention have made various studies on a heat dissipation board having the advantages of ceramics and resin. As a result, it is possible to obtain a thermally conductive insulating sheet having high thermal conductivity by cutting a molded body of a composite material containing high thermal conductive ceramic particles into a thickness that is equal to or less than the average particle diameter of the ceramic particles, The inventors have found that a heat conductive insulating substrate can be obtained by using a heat conductive insulating sheet, and have reached the present invention.

  That is, the present invention is characterized by cutting a molded body of a ceramic-resin composite material containing high thermal conductive ceramic particles and a resin into a thickness less than the average particle diameter of the high thermal conductive ceramic particles. The manufacturing method of a conductive insulating sheet, and the manufacturing method of the heat conductive insulating substrate with metal foil which adhere | attach a metal foil on the surface of this heat conductive insulating sheet via a resin adhesive.

  According to the present invention, it is possible to realize a thermally conductive insulating substrate having high thermal conductivity and being difficult to break.

  According to the present invention, since a molded body of a ceramic-resin composite material containing high thermal conductive ceramic particles and a resin is cut to a thickness equal to or less than the average particle diameter of the high thermal conductive ceramic particles, the obtained thermal conductivity is obtained. The insulating sheet has high thermal conductivity because high thermal conductive ceramic particles penetrate through the thickness direction of the sheet. Moreover, the heat conductive insulation board | substrate with a metal foil manufactured using this heat conductive insulation sheet also has a high heat conductivity.

  In the present invention, a molded body of a ceramic-resin composite material containing high thermal conductive ceramic particles and a resin is first manufactured.

  The high thermal conductivity ceramic particles used in the present invention are not particularly limited, and known high thermal conductivity ceramics can be used. The high thermal conductivity ceramics referred to here are those having a bulk thermal conductivity of 30 W / mK or more. Examples of such ceramics include aluminum nitride, boron nitride, magnesium oxide, zinc oxide, and alumina. The shape of the high thermal conductive ceramic particles is not particularly limited, and any shape such as a crushed shape, a rounded shape with rounded corners, and a spherical shape can be used.

  The average particle diameter of the high thermal conductive ceramic particles used in the present invention is not particularly limited as long as it is equal to or greater than the thickness of the thermal conductive insulating sheet to be obtained, and may be determined according to the thickness of the sheet. When the average particle size is smaller than the thickness of the heat conductive insulating sheet to be obtained, when the heat conductive insulating sheet is produced by the method of the present invention, the high heat conductive ceramic having a particle size smaller than the thickness of the heat conductive insulating sheet Since there are many particles and the number of highly thermally conductive ceramic particles penetrating in the thickness direction of the sheet is small, a thermally conductive insulating sheet having sufficient thermal conductivity may not be obtained. In order to obtain a sufficient thermal conductivity, the average particle size is preferably equal to or greater than the thickness of the thermal conductive insulating sheet to be obtained, and more preferably 1.2 times the thickness. The upper limit of the average particle diameter is not particularly limited, but is preferably 10 times or less of the thickness in that it does not easily hinder the production. The particle size distribution is not particularly limited, but it is preferable to have a structure close to close-packing in which different particle diameters are appropriately distributed from the viewpoint of obtaining a sheet having high thermal conductivity.

  The resin for producing the thermally conductive insulating sheet of the present invention is not particularly limited, and a known material can be used. Examples of the resin include polyethylene, polypropylene, ethylene-propylene copolymer, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl alcohol, polyacetal, fluororesin (polypropylene). Vinylidene chloride, polytetrafluoroethylene, etc.), polyethylene terephthalate, polybutylene terephthalate, polyethylene 2,6 naphthalate, polystyrene, polyacrylonitrile, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene copolymer (ABS) resin, polyphenylene ether (PPE) resin, modified PPE resin, aliphatic polyamide, aromatic polyamide, polyimide, polyamideimide, polymethacrylic acid (polymethacrylic acid) Polymethacrylic acid esters such as chill), polyacrylic acids, polycarbonate, polyphenylene sulfide (hereinafter also referred to as PPS), polysulfone, polyethersulfone, polyethernitrile, polyetherketone, polyetheretherketone, polyketone, liquid crystal polymer, Thermoplastic resins such as ionomers; Bismaleimide resins such as epoxy resins, silicone resins, thermosetting imide resins, acrylic resins, cyanate resins, urethane resins, phenol resins, melamine resins, aromatic bismaleimides and bismaleimide triazine resins, thermosetting Thermosetting resins such as curable polyamideimide, urea resin, unsaturated polyester resin, benzoguanamine resin, alkyd resin, diallyl phthalate resin, etc. Butter, acrylic resins, silicone resins, thermosetting imide resin and urethane resin easy handling, more preferred in view of properties of the heat dissipation material.

  The high heat conductive ceramic particles and the resin are mixed to obtain a ceramic-resin composite material containing the high heat conductive ceramic particles and the resin, but the mixing ratio of the high heat conductive ceramic particles and the resin is not particularly limited. However, in order to increase the thermal conductivity of the substrate, the amount of the ceramic particles is preferably 40 vol% or more, preferably 50 vol% or more with respect to the ceramic-resin composite material containing the high heat conductive ceramic particles and the resin after mixing. More preferably, it is 60 vol% or more. In order to realize such high filling, it is also preferable to surface-treat the high thermal conductive ceramic particles in advance. Surface treatment agents used for such purposes include acidic phosphate esters, carboxylic acids, isocyanates, aluminate coupling agents, silane coupling agents, titanate coupling agents, anionic surfactants, nonionic surfactants. Etc. When the particles are aluminum nitride, boron nitride, or alumina, acidic phosphate ester, carboxylic acid or isocyanate is preferable.

  The mixing method of the high thermal conductive ceramic particles and the resin is not limited at all, and can be performed using a general mixer. Examples of such a mixer include a planetary mixer, a kneader such as a trimix, a roll kneader such as a triple roll, and a crusher.

  The method for producing a ceramic-resin composite material by molding and curing the ceramic-resin composite material is not particularly limited, and a known method may be used. In the case of a thermoplastic resin, it can be molded and cured using changes in viscoelastic behavior with temperature, and in the case of a thermosetting resin, reactions such as radical polymerization, ionic polymerization, condensation, and cyclization are used. Can be molded and cured. The shape of the molded body is not particularly limited, but is preferably such that it maximizes the utilization efficiency of the raw material, and is generally a rectangular parallelepiped shape, a cylindrical shape, or the like.

  Next, the ceramic-resin composite material compact is cut to a thickness equal to or less than the average particle diameter of the high thermal conductive ceramic particles to produce a thermal conductive insulating sheet. By cutting the ceramic-resin composite material compact to a thickness equal to or less than the average particle diameter of the high thermal conductivity ceramic particles, the high thermal conductivity ceramic particles contained in the compact are in the thickness direction of the thermal conductive insulating sheet. Therefore, the thermal conductivity of the obtained heat conductive insulating sheet is high.

  The cutting method of the molded body of the ceramic-resin composite material for producing the thermally conductive insulating sheet of the present invention is not particularly limited, and a known method can be used. In general, a wire saw, a band saw, a wheel saw, a laser, a water jet or the like can be used, but the most preferable method industrially is a wire saw.

  The thickness of the heat conductive insulating sheet produced by the production method of the present invention is not particularly limited, but is generally in the range of 100 to 10,000 μm, preferably in the range of 200 to 2,000 μm. is there.

  The thermally conductive insulating sheet obtained by the production method of the present invention can be used as a heat dissipation material. For example, high heat with a metal foil can be obtained by bonding a metal foil to the surface of the thermally conductive insulating sheet via a resin adhesive. A conductive insulating substrate can be used.

  The adhesive strength of the resin adhesive varies depending on the use, but generally it is preferably 10 MPa or more. Further, it is desirable that this resin adhesive has high heat resistance. For example, it is preferable that the resin adhesive can withstand the temperature of the step of joining the LED element and the substrate, which is called solder reflow for mounting the LED on the substrate. In general, since the reflow process is performed at a temperature of 250 ° C. or higher, it is desirable to have heat resistance enough to withstand several minutes in such a temperature range. For this reason, although the component of the resin adhesive used for this invention is not specifically limited, It is preferable that they are a polyepoxy resin, a polyimide resin, a silicone resin, PPS resin, etc.

  As a specific example of the polyepoxy resin, a material composed of a raw material epoxy resin and a curing agent is common. As raw material epoxy resins, bisphenol A type or bisphenol F type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins and other polyfunctional epoxy resins, and bisphenol A type or bisphenol F type epoxy resins are combined with the above polyfunctional epoxy resins. Additions are listed. Moreover, a hardening agent is not specifically limited, A well-known thing is used as a hardening | curing agent of an epoxy resin. Specific examples include amines, polyamides, imidazoles, acid anhydrides, boron trifluoride-amine complexes called latent curing agents, dicyandiamide, organic acid hydrazides, phenol novolac resins, bisphenol novolac resins, cresol novolac resins, etc. Examples thereof include compounds having two or more hydroxyl groups in one molecule, diphenyliodonium hexafluorophosphate, triphenylsulfonium hexafluorophosphate as a photocuring agent, and the like. Among these, amine, imidazole, and acid anhydride are preferable.

As a specific example of the polyimide resin, an aromatic polyimide such as obtained by dehydration cyclization of an aromatic tetracarboxylic acid anhydride and an aromatic diamine is preferable, and a polysiloxane obtained using a silicone having an amino group at the terminal end. It is also preferable to use an (imide-siloxane) resin. In addition, polyamic acid, which is a polymer of tetracarboxylic dianhydride and diamine, is applied to a heat conductive insulating sheet or metal foil, and after forming a thin film, it is heated and dehydrated and cyclized to form a polyimide resin film. I can do it.

  The silicone resin is preferably a crosslinked product, and specific examples thereof include addition reaction crosslinkable silicone resins, condensation reaction crosslinkable silicone resins, and radical reaction crosslinkable silicone resins. The above addition reaction is a reaction in which a siloxane having hydrogen-bonded silicon is added to a silicone resin containing a vinyl group, and a reaction catalyst of a platinum group element compound is generally used. Examples of such platinum group element compounds include platinum-based catalysts such as chloroplatinic acid, platinum olefin complexes, platinum vinylsiloxane complexes, platinum black, and platinum triphenylphosphine complexes. The above condensation reaction is a reaction for dehydrating and condensing a silicone resin having a silanol group. In order to accelerate the reaction, a metal compound such as an organotin compound, an alkoxy group-containing compound, an acetoxy group-containing silane, or a ketone oxime group-containing silane A curing agent such as an aminoxy group-containing siloxane is used. Cross-linking by radical reaction is to cross-link a silicone resin having an unsaturated hydrocarbon group such as a vinyl group using an organic peroxide as a radical curing agent. Examples of the organic peroxide include benzoyl peroxide, 2,4 -Dichlorobenzoyl peroxide, dicumyl peroxide, cumyl-t-butyl peroxide, 2,5-dimethyl-2,5-di-t-butylperoxyhexane, di-t-butyl peroxide, etc. .

  Thermally conductive insulating sheets are mainly composed of ceramics, so they generally have a low coefficient of thermal expansion, whereas the metal used in conductive circuits has a much higher coefficient of thermal expansion. Stress remains in the adhesive layer, negatively affecting adhesion. Further, due to the difference in thermal expansion coefficient, internal stress generated by a thermal cycle during use increases, which causes a decrease in adhesiveness. For this reason, it is desirable that the elastic modulus of the resin adhesive layer be as small as possible without adversely affecting the adhesiveness, and it is preferably 300 kgf / mm or less.

  A silane coupling agent, a titanate coupling agent, an acidic phosphate ester, a phosphonic acid compound, or the like can be added to the resin adhesive in order to improve adhesion to ceramics and metal foil. For these adhesion promoting components, it is also preferable to contact the resin adhesive after being applied to the heat conductive insulating sheet and / or metal foil in advance. In such a case, the adhesion promoting component is diluted with a solvent and then sprayed. After applying to the heat conductive insulating sheet and / or metal by a method selected from spin, dipping, etc., the solvent may be dried.

  In addition, since the resin adhesive layer is essentially a resin, it has a lower thermal conductivity than the thermally conductive insulating sheet or metal, and causes a large thermal resistance. For this reason, it is preferable to form a resin adhesive layer by adding a highly thermally conductive filler to the resin adhesive. Examples of such high thermal conductive fillers include aluminum nitride, boron nitride, alumina, magnesium oxide, zinc oxide and the like. It is also a preferred embodiment to use a filler that has been surface-treated for the purpose of improving the affinity with the resin component and improving water resistance. For such surface treatment, acidic phosphate ester, carboxylic acid, isocyanate, aluminate coupling agent, silane coupling agent, titanate coupling agent, anionic surfactant, nonionic surfactant, etc. may be used. I can do it. In the case where the filler is aluminum nitride, boron nitride, or alumina, it is preferable that the surface treatment is carried out using acidic phosphate ester, carboxylic acid or isocyanate as the surface treatment agent.

  The mixing method of these fillers and other components of the resin adhesive is not limited at all, and can be performed using a general mixer. Examples of such mixers include planetary mixers and trimixes. Roll kneaders such as kneaders, three rolls, and crushers.

  The thermal conductivity of the resin adhesive layer is not particularly limited, but is preferably as high as possible in order to reduce the thermal resistance of the thermally conductive insulating substrate with metal foil, preferably 1 W / mK or more, and 2 W / mK. It is more preferable that

  The thickness of the resin adhesive layer in the thermally conductive insulating substrate with metal foil of the present invention is not particularly limited and should be determined from the balance of overall performance in view of adhesive strength, durability, etc. From the viewpoint of the thermal resistance of the substrate, it is desirable to be as thin as possible, preferably in the range of 1 to 10 μm, more preferably in the range of 1 to 5 μm.

  The metal foil used for the thermally conductive insulating substrate with metal foil of the present invention is not particularly limited, and gold foil, silver foil, copper foil, aluminum foil, etc. can be used, but copper foil is used from the viewpoint of electrical conductivity and cost. Are preferably used. The thickness of the copper foil is not particularly limited, but generally 5 to 105 μm, preferably about 8 to 35 μm is used. Although the manufacturing method of copper foil is not specifically limited, The copper foil generally used is a rolled copper foil and an electrolytic copper foil.

The thermal conductivity of the thermally conductive insulating substrate with a metal foil in the present invention is preferably evaluated without the metal foil because the thermal conductivity of the entire substrate varies greatly depending on the thickness of the metal foil. The thermal conductivity of a composite layer composed of a heat conductive insulating sheet and a resin adhesive layer is expressed by the following relational expression d ₁ / λ ₁ = (d ₂ / λ ₂ ) + ( d ₃ / λ ₃ )
d ₁ : thickness of the composite layer d ₂ : thickness of the resin adhesive layer d ₃ : thickness of the thermally conductive insulating sheet λ ₁ : thermal conductivity of the composite layer λ ₂ : thermal conductivity of the resin adhesive layer λ ₃ : It can be theoretically obtained from the thermal conductivity of the thermally conductive insulating sheet as follows.

Thermal conductivity of composite layer λ ₁ = d ₁ / ((d ₂ / λ ₂ ) + (d ₃ / λ ₃ ))
The thermal conductivity of this composite layer is preferably 40 W / mK or more, and more preferably 50 W / mK.

  The process for producing the thermally conductive insulating substrate with metal foil of the present invention is not particularly limited, and for example, a generally known method can be adopted as a process for producing a printed board. To illustrate the flow of the manufacturing process, in order to apply the resin adhesive dissolved in the solvent to the heat conductive insulating sheet of the present invention, dry the solvent, press the metal foil, and then cure the resin adhesive layer There is a process of heating. However, it is also possible to form the resin adhesive layer on the surface of the metal foil in advance, and in such a case, the process of pressing the metal foil with the adhesive layer on the heat conductive insulating sheet and heating is typical. is there.

  In order to improve the adhesive strength between the heat conductive insulating sheet or metal foil and the resin adhesive, it is also preferable to perform a primer treatment. For this reason, acid phosphate ester diluted with solvent, carboxylic acid, isocyanate, silane coupling agent, titanate coupling agent, anionic surfactant, nonionic surfactant, phosphonic acid compound, etc. The process of apply | coating and applying a resin adhesive after drying a solvent is preferable. In particular, when the highly thermally conductive ceramic particles in the thermally conductive insulating sheet are alumina or aluminum nitride, the surface treatment is preferably performed using acidic phosphate ester, carboxylic acid or isocyanate.

  The application of the thermally conductive insulating substrate with metal foil of the present invention is not particularly limited, and can be used for general applications as an electronic circuit board that requires heat dissipation and insulation. Examples of such applications include power electronics applications such as converters and inverters, LED applications such as lighting LEDs, industrial LEDs, and vehicle-mounted LEDs, and IC and LSI substrates.

  EXAMPLES Hereinafter, although an Example and an application example demonstrate this invention concretely, this invention is not limited to these examples.

  The test method used in the present invention is shown below.

(Average particle size of high thermal conductive ceramic particles)
Using a scanning electron microscope (JSM-5300, manufactured by JEOL Ltd.), take a picture of the powder at an appropriate magnification according to the particle diameter, and measure the size of any 100 particles in the field of view. The average value was taken as the primary particle size.

(The thickness of the heat conductive insulating sheet)
Using a micrometer (MDE-25MJ: manufactured by Mitutoyo Corporation), the thickness of a point approximately 10 mm inside from the side was measured with a square of the substrate, and the average value thereof was defined as the thickness.

(Thermal conductivity of thermal conductive insulating sheet)
The thermal conductivity of the sheet was measured using a rapid thermal conductivity meter (QTM-500, manufactured by Kyoto Electronics Industry Co., Ltd.). Quartz glass, silicone rubber and zirconia were used for the reference.

(Thickness of resin adhesive layer)
Cut the thermally conductive insulating substrate with metal foil after curing, and observe the cross section at a magnification of 2,000, 5,000 or 10,000 using a scanning electron microscope (JSM-5300: manufactured by JEOL) The thickness of the resin adhesive was measured at 10 points in the same field of view, and the average was taken as the thickness of the resin adhesive.

(Thermal conductivity of resin adhesive)
The resin adhesive slurry is formed on a release PET film using a bar coater (PI-1210: manufactured by Tester Sangyo Co., Ltd.), cured at 120 ° C. with epoxy resin, and at 150 ° C. with silicone resin and polyimide resin. After curing, the PET film was peeled off. The polyimide resin was then subjected to final curing at 200 ° C. The thickness of the film after drying and curing was about 200 to 300 μm. The thermal conductivity of these samples was measured with a rapid thermal conductivity meter (QTM-500: manufactured by Kyoto Electronics Industry Co., Ltd.). For the reference, quartz glass, silicone rubber and zirconia having a thickness of 2 cm, a length of 15 cm, and a width of 6 cm were used.

(Adhesive strength)
After nickel plating on the surface of the metal foil and subsequent gold plating, a 42 alloy nail head pin having a diameter of 1.1 mm and plated with nickel was soldered to the gold plated surface with Pb-Sn solder, and the nail head pin was fixed to 10 mm. The maximum tensile strength when the nail head pin was peeled off at a speed of / min was used as the bonding strength (MPa).

(Solder heat resistance)
A test piece having a width of 10 m and a length of 100 mm was cut out from a thermally conductive insulating substrate with a metal foil produced by the method described in each example. The test piece was allowed to stand at 25 ° C. and 50% relative humidity for 24 hours, and then immersed in a solder bath at 270 ° C. for 60 seconds, and the adhesion state was observed and the presence or absence of defects such as foaming, blistering, and peeling was confirmed.

Example 1
A sintered body of aluminum nitride (thermal conductivity 177 W / mK: manufactured by Tokuyama Corporation) was pulverized and classified with a 24-mesh sieve. The average particle diameter of the obtained particles was 332 μm. 50 g of bisphenol A type epoxy resin (1004: manufactured by Mitsubishi Chemical Corporation), 50 g of o-cresol novolak type epoxy resin (YDCN703: manufactured by Tohto Kasei Co., Ltd.), 1-cyanoethyl-2-phenylimidazolium trimellitate (2PZCN-PW: Shikoku) 2 g) (mixed by Kasei Co., Ltd.) was mixed to make a uniform solution. To 80 g of this solution, 187 g of aluminum nitride particles were added and mixed in a mortar. This mixture was degassed at 80 ° C., poured into a polytetrafluoroethylene mold having holes of 120 mm × 50 mm × t10 mm, pressed from both sides with a polytetrafluoroethylene plate, and then cured at 120 ° C. for 5 hours. did. The cured body was cooled to room temperature, and then cut with a wheel diamond saw (OL-160: manufactured by Orly) to 120 mm × 50 mm × t 200 μm.

  Table 1 shows the physical properties of the obtained heat conductive insulating sheet.

Example 2
To 150 g of the aluminum nitride particles obtained in Example 1, 1.8 g of Phosmer M (Acid Phosphooxymethacrylate: Unichemical Co.) and 120 g of IPA were added and stirred, and then irradiated with ultrasonic waves to obtain a uniform dispersion. Then, IPA was volatilized until the whole became powdery while applying hot air from a dryer under stirring. This powder was dried in an oven at 120 ° C. for 15 hours to obtain surface-treated aluminum nitride particles.

  50 g of bisphenol A type epoxy resin (1004: manufactured by Mitsubishi Chemical Corporation), 50 g of o-cresol novolak type epoxy resin (YDCN703: manufactured by Tohto Kasei Co., Ltd.), 1-cyanoethyl-2-phenylimidazolium trimellitate (2PZCN-PW: Shikoku) 2 g) (made by Kasei Co., Ltd.) was mixed to make a uniform solution. 120 g of the surface-treated aluminum nitride particles were added to 80 g of this solution and mixed in a mortar. This mixture was degassed at 80 ° C., poured into a polytetrafluoroethylene mold having holes of 120 mm × 50 mm × t10 mm, pressed from both sides with a polytetrafluoroethylene plate, and then cured at 120 ° C. for 5 hours. did. The cured body was cooled to room temperature, and then cut with a wheel diamond saw (OL-160: manufactured by Orly) to a thickness of 150 μm.

  Table 1 shows the physical properties of the obtained heat conductive insulating sheet.

Example 3
A sintered body of aluminum nitride (thermal conductivity 177 W / mK: manufactured by Tokuyama Corporation) was pulverized and classified with a 20 mesh sieve. The average particle diameter of the obtained particles was 504 μm. To 500 g of the aluminum nitride particles, 6 g of Phosmer M (manufactured by Unichemical Co.) and 400 g of IPA were added and stirred, followed by ultrasonic irradiation to obtain a uniform dispersion. The dispersion was transferred to a mortar, and IPA was volatilized until the whole became powdery while applying hot air from a dryer under stirring. This powder was dried in an oven at 120 ° C. for 15 hours to obtain surface-treated aluminum nitride particles.

  Bisphenol A type methacrylic resin (D-2.6E: Shin-Nakamura Chemical Co., Ltd.) 50 g, polyethylene glycol type methacrylic resin (3G: Shin-Nakamura Chemical Co., Ltd.) 50 g, t-butylcumyl peroxide (Perbutyl C: NOF Corporation) ) 2g was mixed to make a uniform solution. To 50 g of this solution, 200 g of surface-treated aluminum nitride particles were added and mixed in a mortar. This mixture was degassed at 80 ° C., poured into a polytetrafluoroethylene mold having holes of 120 mm × 50 mm × t10 mm, pressed from both sides with a polytetrafluoroethylene plate, and then cured at 120 ° C. for 5 hours. did. The cured body was cooled to room temperature and then cut to a thickness of 350 μm with a wheel diamond saw (OL-160: manufactured by Orly).

  Table 1 shows the physical properties of the obtained heat conductive insulating sheet.

Example 4
A magnesium oxide sintered body (thermal conductivity 71 W / mK: manufactured by Maruwa) was pulverized and classified with a 14-mesh sieve. The average particle diameter of the obtained particles was 723 μm. 100 g of a silicone resin (KR-169: manufactured by Shin-Etsu Chemical Co., Ltd.) and 2 g of a curing agent (D-168: manufactured by Shin-Etsu Chemical Co., Ltd.) were added and mixed with stirring until a uniform solution was obtained. 200 g of the magnesium oxide particles were added to 50 g of this solution and mixed in a mortar. This mixture was vacuum degassed at 80 ° C., then poured into a polytetrafluoroethylene mold having holes of 120 mm × 50 mm × t 10 mm, pressed from both sides with a polytetrafluoroethylene plate, and cured at 1550 ° C. for 3 hours. did. The cured body was cooled to room temperature, and then cut with a wheel diamond saw (OL-160: manufactured by Orly) to a thickness of 500 μm.

  Table 1 shows the physical properties of the obtained heat conductive insulating sheet.

Comparative Example 1
50 g of bisphenol A type epoxy resin (1004: manufactured by Mitsubishi Chemical Corporation), 50 g of o-cresol novolak type epoxy resin (YDCN703: manufactured by Tohto Kasei Co., Ltd.), 1-cyanoethyl-2-phenylimidazolium trimellitate (2PZCN-PW: Shikoku) 2 g) (mixed by Kasei Co., Ltd.) was mixed to make a uniform solution. To 80 g of this solution, 187 g of aluminum nitride powder (grade H, average particle size 0.7 μm: manufactured by Tokuyama Corporation) was added and mixed in a mortar. This mixture was degassed at 80 ° C., poured into a polytetrafluoroethylene mold having holes of 120 mm × 50 mm × t10 mm, pressed from both sides with a polytetrafluoroethylene plate, and then cured at 120 ° C. for 5 hours. did. The cured body was cooled to room temperature, and then cut with a wheel diamond saw (OL-160: manufactured by Orly) to a thickness of 200 μm.

  Table 1 shows the physical properties of the obtained heat conductive insulating sheet.

Comparative Example 2
50 g of bisphenol A type epoxy resin (1004: manufactured by Mitsubishi Chemical Corporation), 50 g of o-cresol novolak type epoxy resin (YDCN703: manufactured by Tohto Kasei Co., Ltd.), 1-cyanoethyl-2-phenylimidazolium trimellitate (2PZCN-PW: Shikoku) 2 g) (mixed by Kasei Co., Ltd.) was mixed to make a uniform solution. To 50 g of this solution, 200 g of aluminum nitride powder (average particle size: 4.5 μm, manufactured by Tokuyama Corporation) was added and mixed in a mortar. This mixture was degassed at 80 ° C., poured into a polytetrafluoroethylene mold having holes of 120 mm × 50 mm × t10 mm, pressed from both sides with a polytetrafluoroethylene plate, and then cured at 120 ° C. for 5 hours. did. The cured body was cooled to room temperature, and then cut with a wheel diamond saw (OL-160: manufactured by Orly) to a thickness of 200 μm.

  Table 1 shows the physical properties of the obtained heat conductive insulating sheet.

Comparative Example 3
50 g of bisphenol A type epoxy resin (1004: manufactured by Mitsubishi Chemical Corporation), 50 g of o-cresol novolak type epoxy resin (YDCN703: manufactured by Tohto Kasei Co., Ltd.), 1-cyanoethyl-2-phenylimidazolium trimellitate (2PZCN-PW: Shikoku) 2 g) (mixed by Kasei Co., Ltd.) was mixed to make a uniform solution. To 50 g of this solution, 200 g of aluminum oxide powder (AX10-32, average particle size: 9.1 μm: manufactured by Micron) was added and mixed in a mortar. This mixture was degassed at 80 ° C., poured into a polytetrafluoroethylene mold having holes of 120 mm × 50 mm × t10 mm, pressed from both sides with a polytetrafluoroethylene plate, and then cured at 120 ° C. for 5 hours. did. The cured body was cooled to room temperature, and then cut with a wheel diamond saw (OL-160: manufactured by Orly) to a thickness of 200 μm.

  Table 1 shows the physical properties of the obtained heat conductive insulating sheet.

Comparative Example 4
A sintered body of aluminum nitride (thermal conductivity 177 W / mK: manufactured by Tokuyama Corporation) was pulverized and classified with a 150 mesh sieve. The average particle diameter of the obtained particles was 57 μm. To 500 g of the aluminum nitride particles, 6 g of Phosmer M (manufactured by Unichemical Co.) and 400 g of IPA were added and stirred, followed by ultrasonic irradiation to obtain a uniform dispersion. The dispersion was transferred to a mortar, and IPA was volatilized until the whole became powdery while applying hot air from a dryer under stirring. This powder was dried in an oven at 120 ° C. for 15 hours to obtain surface-treated aluminum nitride particles.

  Bisphenol A type methacrylic resin (D-2.6E: Shin-Nakamura Chemical Co., Ltd.) 50 g, polyethylene glycol type methacrylic resin (3G: Shin-Nakamura Chemical Co., Ltd.) 50 g, t-butylcumyl peroxide (Perbutyl C: NOF Corporation) ) 2g was mixed to make a uniform solution. To 50 g of this solution, 200 g of surface-treated aluminum nitride particles were added and mixed in a mortar. This mixture was degassed at 80 ° C., poured into a polytetrafluoroethylene mold having holes of 120 mm × 50 mm × t 10 mm, pressed from both sides with a polytetrafluoroethylene plate, and then cured at 120 ° C. for 5 hours. did. The cured body was cooled to room temperature, and then cut with a wheel diamond saw (OL-160: manufactured by Orly) to a thickness of 200 μm.

  Table 1 shows the physical properties of the obtained heat conductive insulating sheet.

Comparative Example 5
The thickness and thermal conductivity of a metal base substrate (M3, copper foil 35 μm / insulating layer 80 μm / aluminum plate 1.0 mm: manufactured by Meiko) were measured.

  Table 1 shows the physical properties of the obtained heat conductive insulating sheet.

Example 6
5 g of bisphenol A type epoxy resin (1004: manufactured by Mitsubishi Chemical Corporation), 5 g of o-cresol novolac type epoxy resin (YDCN703: manufactured by Tohto Kasei Co., Ltd.), 1-cyanoethyl-2-phenylimidazolium trimellitate (2PZCN-PW: Shikoku) 0.2 g of Kasei Co., Ltd., 10 g of methyl ethyl ketone (manufactured by Wako Pure Chemical Industries, Ltd.) and 10 g of toluene (manufactured by Wako Pure Chemical Industries, Ltd.) were mixed and dissolved to obtain a uniform solution. 20 g of aluminum nitride powder (H grade: manufactured by Tokuyama Corporation) was added to this solution and dispersed by irradiating ultrasonic waves with stirring to obtain a resin adhesive slurry. Next, 10 g of Phosmer M (manufactured by Unichemical Co.) was dissolved in 100 g of toluene to obtain a uniform primer solution. This primer solution was spin-coated on the heat conductive insulating sheet obtained in Example 3, and then dried at 120 ° C. for 1 hour. The coated adhesive slurry was spin-coated on this coated surface, allowed to stand at room temperature for 30 minutes, and then vacuum dried at 80 ° C. for 30 minutes. A 18 μm thick copper foil (rolled copper foil HPF-ST18-X: manufactured by Hitachi Cable Co., Ltd.) was pressure-bonded to the coated surface, and then cured at 120 ° C. for 3 hours to obtain a thermally conductive insulating substrate with copper foil. It was. Table 2 shows the physical properties and the like of the obtained heat conductive insulating substrate with copper foil.

Example 7
10 g of aluminum nitride powder (H grade: manufactured by Tokuyama Co., Ltd.) is added to 20 g of an N-butyl-2-pyrrolidone solution of polyamic acid (U-varnish-A: manufactured by Ube Industries Co., Ltd.) and dispersed by irradiating ultrasonic waves with stirring. Thus, a resin adhesive slurry was obtained. This slurry was spin-coated on the thermally conductive insulating sheet obtained in Example 3, and allowed to stand at room temperature for 30 minutes, then dried at 100 ° C. for 1 hour, 150 ° C. for 1 hour, and further at 200 ° C. for 1 hour. Then, a 18 μm-thick copper foil (rolled copper foil HPF-ST18-X: manufactured by Hitachi Cable Ltd.) was pressure-bonded and cured at 350 ° C. for 30 minutes to obtain a thermally conductive insulating substrate with copper foil. Table 2 shows the physical properties and the like of the obtained heat conductive insulating substrate with copper foil.

Example 8
10 g of boron nitride powder (MBN-010-T: manufactured by Mitsui Chemicals) is added to 20 g of an N-butyl-2-pyrrolidone solution of polyamic acid (U-varnish-A: manufactured by Ube Industries), and ultrasonic waves are applied with stirring. Irradiated and dispersed to obtain a resin adhesive slurry. This slurry was spin-coated on the heat conductive insulating sheet obtained in Example 1, and allowed to stand at room temperature for 30 minutes, then dried at 100 ° C. for 1 hour, 150 ° C. for 1 hour, and further at 200 ° C. for 1 hour. Then, a 18 μm-thick copper foil (rolled copper foil HPF-ST18-X: manufactured by Hitachi Cable Ltd.) was pressure-bonded and cured at 350 ° C. for 30 minutes to obtain a thermally conductive insulating substrate with copper foil. Table 2 shows the physical properties and the like of the obtained heat conductive insulating substrate with copper foil.

Comparative Example 6
5 g of bisphenol A type epoxy resin (1004: manufactured by Mitsubishi Chemical Corporation), 5 g of o-cresol novolac type epoxy resin (YDCN703: manufactured by Tohto Kasei Co., Ltd.), 1-cyanoethyl-2-phenylimidazolium trimellitate (2PZCN-PW: Shikoku) 0.2 g of Kasei Co., Ltd., 10 g of methyl ethyl ketone (manufactured by Wako Pure Chemical Industries, Ltd.) and 10 g of toluene (manufactured by Wako Pure Chemical Industries, Ltd.) were mixed and dissolved to obtain a uniform solution. 20 g of aluminum nitride powder (H grade: manufactured by Tokuyama Corporation) was added to this solution and dispersed by irradiating ultrasonic waves with stirring to obtain a resin adhesive slurry. Next, 10 g of Phosmer M (manufactured by Unichemical Co.) was dissolved in 100 g of toluene to obtain a uniform primer solution. This primer solution was spin-coated on the heat conductive insulating sheet obtained in Comparative Example 1, and then dried at 120 ° C. for 1 hour. The coated adhesive slurry was spin-coated on this coated surface, allowed to stand at room temperature for 30 minutes, and then vacuum dried at 80 ° C. for 30 minutes. A 18 μm thick copper foil (rolled copper foil HPF-ST18-X: manufactured by Hitachi Cable Co., Ltd.) was pressure-bonded to the coated surface, and then cured at 120 ° C. for 3 hours to obtain a thermally conductive insulating substrate with copper foil. It was. Table 2 shows the physical properties and the like of the obtained heat conductive insulating substrate with copper foil.

Comparative Example 7
10 g of aluminum nitride powder (H grade: manufactured by Tokuyama Co., Ltd.) is added to 20 g of an N-butyl-2-pyrrolidone solution of polyamic acid (U-varnish-A: manufactured by Ube Industries Co., Ltd.) and dispersed by irradiating ultrasonic waves with stirring. Thus, a resin adhesive slurry was obtained. This slurry was spin-coated on the heat conductive insulating sheet obtained in Comparative Example 4, left at room temperature for 30 minutes, dried at 100 ° C. for 1 hour, 150 ° C. for 1 hour, and further at 200 ° C. for 1 hour. Then, a 18 μm-thick copper foil (rolled copper foil HPF-ST18-X: manufactured by Hitachi Cable Ltd.) was pressure-bonded and cured at 350 ° C. for 30 minutes to obtain a thermally conductive insulating substrate with copper foil. Table 2 shows the physical properties and the like of the obtained heat conductive insulating substrate with copper foil.

Claims (2)

  Production of a thermally conductive insulating sheet, characterized in that a molded body of a ceramic-resin composite material containing high thermal conductive ceramic particles and a resin is cut to a thickness equal to or less than the average particle diameter of the high thermal conductive ceramic particles. Method.   Resin adhesion to the surface of the thermally conductive insulating sheet obtained by cutting a ceramic-resin composite material containing highly thermally conductive ceramic particles and a resin into a thickness less than the average particle diameter of the highly thermally conductive ceramic particles A method for producing a thermally conductive insulating substrate with a metal foil, wherein the metal foil is bonded through an agent.