A resin composition, a metal foil-coated laminate and its applications

Abstract

This invention provides a resin composition, a metal foil-coated laminate, and their applications. The resin composition comprises a combination of resin material and modified boron nitride particles. The modified boron nitride particles are prepared by the following method: mixing boron nitride with a sintering aid, followed by a first sintering and a first crushing to obtain primary particles; then subjecting the primary particles to a second sintering and a second crushing to obtain the modified boron nitride particles. This invention involves two sintering and crushing processes with boron nitride and a specific type and amount of sintering aid. Through a specially designed preparation method, the modified boron nitride particles achieve a high filling rate in the resin material. The resin composition containing these particles exhibits high thermal conductivity, high peel strength, and good adhesion, thereby enabling the metal foil-coated laminate to achieve excellent overall performance in terms of high thermal conductivity and high reliability.

Description

Technical Field

[0001] This invention belongs to the field of copper clad laminate technology, specifically relating to a resin composition, a metal foil laminate, and their applications. Background Technology

[0002] With the rapid development of electronic products, the power consumption of electronic components is increasing, and the heat generated per unit area during operation is also increasing. In order to ensure the operational stability of electronic components, higher requirements are placed on the heat dissipation performance of the substrates used to construct these components. If the heat dissipation of the substrate is poor, the reliability of the entire device will decrease, leading to product failure and shortening the lifespan of the electronic product.

[0003] The core approach to improving the heat dissipation performance of copper-clad laminates in the industry lies in designing highly thermally conductive dielectric layers and copper-clad laminates. Introducing highly thermally conductive materials into the preparation of the dielectric layer and copper-clad laminate is the main method to improve thermal conductivity. Since resins with good thermal conductivity are expensive, adding thermally conductive fillers is currently a common practice. For example, CN115556439A discloses a high-thermal-conductivity polytetrafluoroethylene high-frequency copper-clad laminate, which is prepared by laminating a dielectric layer and copper foil layers and then pressing them together at high temperature. The raw materials for preparing the dielectric layer include: 10-20% fluorinated resin emulsion, 3-6% silane coupling agent, 2-7% fiber reinforcement material, and the remainder being thermally conductive fillers. The thermally conductive fillers include 10-30% layered boron nitride, 20-35% silica powder, 10-15% aluminum nitride, and 10-35% spherical alumina. CN110370750A discloses a high thermal conductivity copper-clad laminate, comprising a core thermally conductive bonding sheet and a surface thermally conductive bonding sheet. The core thermally conductive bonding sheet comprises: 10-35 parts of bisphenol A epoxy resin, 5-10 parts of curing agent, 50-80 parts of filler, and 10-30 parts of flame retardant. The surface thermally conductive bonding sheet comprises: 10-35 parts of surface epoxy resin, 5-10 parts of curing agent, 30-50 parts of filler, and 10-30 parts of flame retardant. The filler in both the core and surface is a mixture of alumina and boron oxide in a 1:1 mass ratio. CN101767481A discloses a high thermal conductivity copper-clad laminate, the preparation method of which includes the following steps: mixing 60-90% of multifunctional epoxy resin and 10-40% of polyurethane by mass to prepare a resin adhesive solution with a solid content of 60-90%; using dicyandiamide as a curing agent and 2-methylimidazole as an accelerator to prepare an adhesive solution with a gel time of 150-450s; using a mixed filler of 40-60% aluminum nitride and 40-60% aluminum oxide as the filler of the adhesive solution; impregnating glass cloth with the adhesive solution to prepare an adhesive sheet; stacking multiple adhesive sheets and applying copper foil; and hot-pressing to form a high thermal conductivity copper-clad laminate.

[0004] Currently, thermally conductive fillers used in copper-clad laminates include alumina, aluminum nitride, boron nitride, boron oxide, and silicon micropowder. Among these, boron nitride exhibits particularly outstanding thermal conductivity and has great application potential in thermal conductive materials. However, boron nitride has a lamellar structure and a large specific surface area, making it difficult to fill in large quantities with resin, which greatly weakens its ability to improve the thermal conductivity of composite materials. Moreover, increasing the amount of thermally conductive filler can lead to poorer adhesion between the adhesive layer and the copper foil and metal substrate, thereby weakening the heat resistance and voltage resistance of the copper-clad laminate, resulting in decreased reliability.

[0005] Therefore, developing a thermally conductive composite material that combines high thermal conductivity with excellent adhesion is an urgent problem to be solved in this field. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a resin composition, a metal foil laminate, and their applications. Through the design of the preparation method, modified boron nitride particles with high thermal conductivity and high filling rate are obtained, enabling the resin composition containing these particles to achieve high thermal conductivity while also possessing high peel strength and excellent adhesion properties. This results in the metal foil laminate achieving excellent comprehensive performance in terms of high thermal conductivity and high reliability.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a resin composition comprising a combination of a resin material and modified boron nitride particles.

[0009] The modified boron nitride particles are prepared by the following method, which includes: mixing boron nitride and a sintering aid, and then subjecting the mixture to a first sintering and a first crushing to obtain primary particles; and subjecting the primary particles to a second sintering and a second crushing to obtain the modified boron nitride particles.

[0010] The sintering aid includes any one or a combination of at least two of calcium oxide, magnesium oxide, silicon oxide, yttrium oxide, niobium oxide, and potassium feldspar; the sintering aid comprises 1-10% by mass, based on the total mass of boron nitride and the sintering aid being 100%.

[0011] This invention involves subjecting boron nitride and a specific type of sintering aid to a first high-temperature sintering and crushing process to obtain primary particles. These primary particles are then subjected to a second high-temperature sintering and crushing process to obtain the modified boron nitride particles. Through the synergistic effect of the sintering aid and the two sintering processes, the filling ratio of the modified boron nitride particles in the resin material can be increased, resulting in a resin composition with high thermal conductivity, high peel strength, and excellent adhesion properties. This effectively improves the overall performance of the metal foil-coated laminate in terms of heat dissipation and reliability.

[0012] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0013] Preferably, the boron nitride includes any one or a combination of at least two of hexagonal boron nitride and cubic boron nitride, with hexagonal boron nitride being more preferred.

[0014] Preferably, the average particle size of the modified boron nitride particles is 0.1-30 μm, for example, it can be 0.2 μm, 0.5 μm, 1 μm, 2 μm, 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, 22 μm, 25 μm or 28 μm, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0015] In this invention, the average particle size can be understood as D. 50 Particle size data can be obtained using an MS3000 Malvern laser particle size analyzer.

[0016] In this invention, the mass content of modified boron nitride particles in the resin composition can be adjusted according to the requirements of thermal conductivity, processability, peel strength, reliability and other properties of the material, and can be 10-92%, more preferably 20-92%.

[0017] Preferably, the mass percentage of modified boron nitride particles in the resin composition is 30-92%, for example, it can be 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85% or 90%, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but 50-90% is further preferred.

[0018] As a preferred embodiment of the present invention, the modified boron nitride particles in the resin composition have a mass percentage content of 30-92%, more preferably 50-90%, thereby giving the resin composition and the metal-clad laminate prepared therefrom high thermal conductivity, high peel strength, and excellent reliability. If the content of modified boron nitride particles is too low, the thermal conductivity of the resin composition and the board will decrease; if the content of modified boron nitride particles is too high, the processability of the resin composition will be poor, making it difficult to prepare qualified copper-clad laminates.

[0019] In this invention, the total mass of the boron nitride and sintering aid is 100%, and the mass of the sintering aid is 1-10%, for example, it can be 2%, 3%, 4%, 5%, 6%, 7%, 8% or 9%, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific values ​​included in the range.

[0020] This invention involves mixing specific types and amounts of sintering aids with boron nitride, followed by two high-temperature sintering and crushing processes to obtain specific modified boron nitride particles. This effectively solves the problem that lamellar boron nitride cannot be extensively filled, resulting in insufficient thermal conductivity of the material. The modified boron nitride particles exhibit excellent thermal conductivity and a high filling rate in resin materials, enabling boron resin compositions containing them to possess both high thermal conductivity and high peel strength. If the amount of sintering aid is <1%, it is difficult to effectively modify boron nitride and increase the filling ratio of boron nitride in the resin; if the amount of sintering aid is >10%, the thermal conductivity of the modified boron nitride and the resin composition containing it will decrease.

[0021] Preferably, the mixed raw materials also include other metal oxides, where "other metal oxides" refers to metal oxides that are different from sintering aids.

[0022] Preferably, the other metal oxides include aluminum oxide and / or beryllium oxide.

[0023] Preferably, based on the total mass of the boron nitride, sintering aid and other metal oxides as 100%, the mass of the other metal oxides is 1-10%, for example, it can be 2%, 3%, 4%, 5%, 6%, 7%, 8% or 9%, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0024] Preferably, the mixing method includes physical dry mixing.

[0025] Preferably, the mixing time is 0.1-3h, for example, it can be 0.2h, 0.4h, 0.5h, 0.8h, 1h, 1.2h, 1.5h, 1.8h, 2h, 2.2h, 2.5h or 2.8h, as well as specific point values ​​between the above point values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific point values ​​included in the range.

[0026] Preferably, the first sintering is carried out in an inert atmosphere.

[0027] Preferably, the inert atmosphere includes a nitrogen atmosphere and / or an argon atmosphere.

[0028] Preferably, the temperature of the first sintering is 300-700℃, for example, it can be 350℃, 400℃, 450℃, 500℃, 550℃, 600℃ or 650℃, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0029] Preferably, the pressure of the first sintering is 1-10 GPa, for example, it can be 2 GPa, 3 GPa, 4 GPa, 5 GPa, 6 GPa, 7 GPa, 8 GPa or 9 GPa, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0030] Preferably, the first sintering time is 1-8 hours, for example, it can be 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours or 7.5 hours, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0031] In this invention, the first sintering is carried out under high temperature and high pressure to obtain a block sintered material, which is then subjected to a first crushing to obtain primary particles.

[0032] Preferably, the first crushing method includes ball milling, for example, wet ball milling, and the wet ball milling is followed by a drying step.

[0033] Preferably, the rotational speed of the first crushing is 500-5000 rpm, for example, it can be 1000 rpm, 1500 rpm, 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm, 4000 rpm or 4500 rpm, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0034] Preferably, the first crushing time is 0.5-6 hours, for example, it can be 0.8 hours, 1 hour, 1.2 hours, 1.5 hours, 1.8 hours, 2 hours, 2.2 hours, 2.5 hours, 2.8 hours, 3 hours, 3.2 hours, 3.5 hours, 3.8 hours, 4 hours, 4.2 hours, 4.5 hours, 4.8 hours, 5 hours, or 5.5 hours, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific values ​​included in the range.

[0035] Preferably, the average particle size of the primary particles is 0.1-50 μm, for example, it can be 0.2 μm, 0.5 μm, 1 μm, 2 μm, 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 18 μm, 20 μm, 22 μm, 25 μm, 28 μm, 30 μm, 35 μm, 40 μm or 45 μm, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0036] Preferably, the second sintering is carried out in an inert atmosphere.

[0037] Preferably, the inert atmosphere includes a nitrogen atmosphere and / or an argon atmosphere.

[0038] Preferably, the second sintering temperature is 700-2000℃, for example, it can be 800℃, 900℃, 1000℃, 1100℃, 1200℃, 1300℃, 1400℃, 1500℃, 1600℃, 1700℃, 1800℃ or 1900℃, as well as specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0039] Preferably, the second sintering time is 2-8 hours, for example, it can be 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, 6.5 hours, 7 hours or 7.5 hours, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0040] As a preferred embodiment of the present invention, the first sintering is carried out under high temperature and high pressure, with a temperature of 300-700℃, a pressure of 1-10 GPa, and a time of 1-8 hours; the second sintering is carried out at high temperature, with a temperature of 700-2000℃, and a time of 2-8 hours, without the need for additional pressure. Through the design and optimization of the two sintering processes, the filling ratio of the modified boron nitride particles in the resin material can be further improved.

[0041] Preferably, the second crushing method includes ball milling, for example, wet ball milling, and further includes a drying step after wet ball milling.

[0042] Preferably, the second crushing speed is 500-5000 rpm, for example, it can be 1000 rpm, 1500 rpm, 2000 rpm, 2500 rpm, 3000 rpm, 3500 rpm, 4000 rpm or 4500 rpm, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0043] Preferably, the second crushing time is 0.5-6 hours, for example, it can be 0.8 hours, 1 hour, 1.2 hours, 1.5 hours, 1.8 hours, 2 hours, 2.2 hours, 2.5 hours, 2.8 hours, 3 hours, 3.2 hours, 3.5 hours, 3.8 hours, 4 hours, 4.2 hours, 4.5 hours, 4.8 hours, 5 hours, or 5.5 hours, as well as specific values ​​between the above values. Due to space limitations and for the sake of brevity, this invention will not exhaustively list the specific values ​​included in the range.

[0044] Preferably, the resin material includes any one or a combination of at least two of the following: epoxy resin, cyanate ester resin, polyphenylene ether resin, polybutadiene resin, styrene-butadiene resin, bismaleimide-triazine resin, bismaleimide resin, polytetrafluoroethylene resin, polyimide resin, phenolic resin, phenolic oxy resin, acrylic resin, liquid crystal resin, benzoxazine resin, and nitrile rubber.

[0045] Preferably, the nitrile rubber includes any one or a combination of at least two of unmodified nitrile rubber, carboxyl-terminated nitrile rubber, and hydroxyl-terminated nitrile rubber.

[0046] More preferably, the resin material includes any one or a combination of at least two of epoxy resin, polyphenylene ether resin, polybutadiene resin, styrene-butadiene resin, bismaleimide resin, phenolic resin, and phenolic oxy resin.

[0047] Preferably, the epoxy resin comprises any one or a combination of at least two of the following: bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, phenolic epoxy resin, biphenyl epoxy resin, phenolic epoxy resin, bisphenol A phenolic epoxy resin, organosilicon modified epoxy resin, phosphorus-containing epoxy resin, brominated epoxy resin, aliphatic epoxy resin, alicyclic epoxy resin, o-cresol epoxy resin, and dicyclopentadiene (DCPD) epoxy resin.

[0048] Preferably, the polyphenylene ether resin is a polyphenylene ether with C=C unsaturated bonds at the end groups, and more preferably a polyphenylene ether with any one or at least two of vinyl benzyl, vinyl phenyl, acrylate, and methacrylate groups at the end groups.

[0049] Preferably, the polybutadiene resin and styrene-butadiene resin both contain crosslinkable active groups C=C, such as 1,2-vinyl based on butadiene monomers.

[0050] Preferably, the resin material in the resin composition has a mass percentage of 8-80%, for example, it can be 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70% or 75%, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, but 9-50% is further preferred.

[0051] In a preferred embodiment, the resin composition comprises, by weight percentage, the following components: 4-50% epoxy resin (e.g., 5%, 8%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or 45%), 0-10% phenolic resin (e.g., 0.1%, 0.3%, 0.5%, 0.8%, 1%, 2%, 4%, 5%, 6%, or 8%), and 40-92% modified boron nitride particles (e.g., 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90%).

[0052] In another preferred embodiment, the resin composition comprises, by weight percentage, the following components: 4-50% hydrocarbon resin (e.g., 5%, 8%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or 45%), 0-10% polyphenylene ether resin (e.g., 0.1%, 0.3%, 0.5%, 0.8%, 1%, 2%, 4%, 5%, 6%, or 8%), and 40-92% modified boron nitride particles (e.g., 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90%).

[0053] In another preferred embodiment, the resin composition comprises, by weight percentage, the following components: 4-50% polyphenylene ether resin (e.g., 5%, 8%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or 45%), 0-10% hydrocarbon resin (e.g., 0.1%, 0.3%, 0.5%, 0.8%, 1%, 2%, 4%, 5%, 6%, or 8%), and 40-92% modified boron nitride (e.g., 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90%).

[0054] The hydrocarbon resin includes polybutadiene resin and / or styrene-butadiene resin, preferably polybutadiene resin.

[0055] Preferably, the resin composition further includes any one or a combination of at least two of the following: accelerator, initiator, crosslinking agent, filler, flame retardant, and curing agent.

[0056] Preferably, the promoter comprises any one or a combination of at least two of imidazole compounds, organic complexes, tertiary amines, tertiary phosphine, and quaternary ammonium salts, with imidazole compounds being more preferred.

[0057] Preferably, the imidazole compound includes any one or a combination of at least two of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-2-methylimidazole, 2-heptadecylimidazole, 2-isopropylimidazole, 2-phenyl-4-methylimidazole, 2-dodecylimidazole, and 1-cyanoethyl-2-methylimidazole.

[0058] Preferably, the mass percentage of the accelerator in the resin composition is ≤8%, for example, it can be 0, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7% or 7.5%, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0059] Preferably, the initiator includes any one or a combination of at least two of organic peroxides, azo initiators, and carbon-based initiators.

[0060] Preferably, the organic peroxide comprises any one or a combination of at least two of α,α'-di(tert-butylperoxym-isopropylbenzene), diisopropylbenzene peroxide, tert-butylperoxym-isopropylbenzene, 1,1-bis(tert-hexylperoxy)-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hex-3-yne, tert-butyl peroxyoctanoate, and tert-butyl peroxybenzoate.

[0061] Preferably, the initiator further includes any one or a combination of at least two of the following: triethylamine, triethylamine salt compounds, quaternary amine salt compounds, 2,4,6-tris(dimethylaminomethylamine)phenol, benzyldimethylamine, imidazoles, tripentylphenolic acid amine, monophenolic compounds, polyphenolic compounds, boron trifluoride, complexes of boron trifluoride organic compounds, triphenyl phosphate, and triphenyl phosphite.

[0062] Preferably, the initiator in the resin composition has a mass percentage content of ≤8%, for example, it can be 0, 0.1%, 0.3%, 0.5%, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7% or 7.5%, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0063] Preferably, the crosslinking agent comprises any one or a combination of at least two of the following: triallyl isocyanurate, polytrilyl isocyanurate, triallyl cyanurate, trimethacrylic acid, diallyl phthalate, divinylbenzene, and polyfunctional (meth)acrylates.

[0064] Preferably, the mass percentage of the crosslinking agent in the resin composition is ≤20%, for example, it can be 0, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 8%, 10%, 12%, 14%, 15%, 16% or 18%, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0065] Preferably, the filler comprises any one or a combination of at least two of the following: silicon dioxide, titanium dioxide, barium titanate, strontium titanate, magnesium titanate, calcium titanate, barium strontium titanate, barium calcium titanate, lead titanate, lead zirconate titanate, lanthanum lead zirconate titanate, barium lanthanum titanate, barium zirconate titanate, hafnium dioxide, lead magnesium niobate, barium magnesium niobate, lithium niobate, potassium niobate, strontium aluminum tantalate, potassium tantalate, barium strontium niobate, barium strontium niobate, barium barium niobate, barium titanium barium niobate, strontium bismuth tantalate, bismuth titanate, rubidium barium titanate, copper titanate, and lead titanate-lead magnesium niobate.

[0066] Preferably, the average particle size (D) of the filler is 50 The particle size is 0.01-50 μm, for example, it can be 0.05 μm, 0.1 μm, 0.5 μm, 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range. It is further preferred to be 0.01-30 μm, and even more preferred to be 0.01-10 μm.

[0067] Preferably, the filler content in the resin composition is ≤20% by mass, for example, it can be 0, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 8%, 10%, 12%, 14%, 15%, 16% or 18%, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0068] Solvents may also be added to the above-mentioned resin composition. The amount of solvent added is selected by those skilled in the art based on experience and process requirements, so that the resin composition reaches a suitable viscosity for use, facilitating impregnation, coating, etc. During subsequent drying, semi-curing, or complete curing stages, the solvent in the resin composition will partially or completely evaporate.

[0069] On the other hand, the present invention provides a resin adhesive comprising the resin composition and solvent as described in the first aspect.

[0070] For example, the solvent includes any one or a combination of at least two of ketone solvents, alcohol solvents, aromatic hydrocarbon solvents, ester solvents, and nitrogen-containing solvents.

[0071] The solvent used in this invention is not particularly limited, and can generally be ketones such as acetone, butanone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; aromatic hydrocarbons such as toluene, xylene, and mesitylene; esters such as ethyl acetate, butyl acetate, and ethoxyethyl acetate; alcohols such as methanol, ethanol, and butanol; ethers such as ethyl cellosolve, butyl cellosolve, ethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol butyl ether, carbitol, and butyl carbitol; and nitrogen-containing solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone. The solvent can be used alone or in combination of two or more.

[0072] The resin composition provided by the present invention is prepared by the following method, the preparation method comprising: mixing and dispersing the components in the resin composition evenly to obtain the resin composition.

[0073] In a second aspect, the present invention provides a prepreg comprising a reinforcing material and a resin composition as described in the first aspect attached to the reinforcing material.

[0074] Preferably, the resin composition is attached to the reinforcing material after impregnation and drying.

[0075] Preferably, the raw materials of the reinforcing material include any one or at least two combinations of natural fibers, organic synthetic fibers, organic fabrics, and inorganic fibers; for example, glass fiber cloth, quartz glass fiber blended cloth, non-woven fabric, quartz cloth, fiber paper, etc.

[0076] For example, the prepreg is prepared by impregnating a reinforcing material with a resin solution of the resin composition and then drying it to obtain the prepreg.

[0077] Preferably, the drying temperature is 100-180℃, for example, it can be 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, 160℃, 165℃, 170℃ or 175℃, and specific values ​​between the above points. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and 115-175℃ is further preferred.

[0078] Preferably, the drying time is 1-30 min, for example, it can be 2 min, 5 min, 8 min, 10 min, 15 min, 20 min or 25 min, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range, and 2-20 min is further preferred.

[0079] Thirdly, the present invention provides a thermally conductive film, the material of which includes the resin composition described in the first aspect.

[0080] Preferably, the thermally conductive film is prepared by coating the resin composition onto a release material and then drying and / or semi-curing it.

[0081] Fourthly, the present invention provides a metal foil laminate, the metal foil laminate comprising a metal foil, and at least one of the prepreg as described in the second aspect and the thermally conductive film as described in the third aspect.

[0082] Preferably, the metal foil in the metal foil-coated laminate includes any one or a combination of at least two of copper foil, aluminum foil, nickel foil, and alloy foil.

[0083] Preferably, the metal foil is copper foil, and the metal foil laminate is copper clad laminate.

[0084] Preferably, the number of prepreg sheets in the metal foil laminate is 1-20, for example, 2, 3, 5, 7, 9, 10, 11, 13, 15, 17 or 19, and the specific point values ​​between the above point values ​​are not exhaustively listed in this invention due to space limitations and for the sake of brevity.

[0085] For example, the method for preparing the metal foil laminate includes: pressing a metal foil onto one or both sides of a prepreg and curing it to obtain the metal foil laminate; or, stacking at least two prepregs into a laminate, then pressing a metal foil onto one or both sides of the laminate and curing it to obtain the metal foil laminate.

[0086] Preferably, the curing is carried out in a press.

[0087] Preferably, the curing temperature is 170-280℃, such as 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃ or 270℃, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0088] Preferably, the curing pressure is 1-10 MPa, for example 1.5 MPa, 2 MPa, 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa or 9 MPa, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0089] Preferably, the curing time is 30-300 min, such as 40 min, 50 min, 60 min, 80 min, 100 min, 120 min, 150 min, 180 min, 200 min, 220 min, 240 min, 260 min or 280 min, and specific values ​​between the above values. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list the specific values ​​included in the range.

[0090] Fifthly, the present invention provides a printed circuit board, the printed circuit board comprising at least one of the prepreg as described in the second aspect, the thermally conductive film as described in the third aspect, and the metal foil laminate as described in the third aspect.

[0091] Compared with the prior art, the present invention has the following beneficial effects:

[0092] (1) In the resin composition provided by the present invention, boron nitride is sintered and crushed twice with a sintering aid of a specific type and amount. Through the special design of the preparation method, the modified boron nitride particles have a high filling rate in the resin material. The resin composition containing it has high thermal conductivity, high peel strength and excellent adhesion performance, thereby achieving excellent comprehensive effect of high thermal conductivity and high reliability in the metal foil laminate.

[0093] (2) Through the design and optimization of the composition and ratio of the resin composition, the present invention enables the copper clad laminate containing it to have a thermal conductivity ≥5.6W / m·k and a peel strength ≥0.8N / mm, and has excellent heat dissipation performance, interlayer bonding force and reliability. Detailed Implementation

[0094] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0095] The following specific preparation examples illustrate the preparation method of the modified boron nitride particles, but the preparation method of the modified boron nitride particles is not limited to these preparation examples.

[0096] In the following preparation examples, boron nitride, sintering aids, and other metal oxides are all commercially available chemicals; among them, boron nitride has a layered structure and was purchased from 3M, CFP003.

[0097] Preparation Examples 1-7

[0098] Modified boron nitride particles AG are prepared by the following method:

[0099] Boron nitride, sintering aid, and optionally other metal oxides were weighed according to the proportions shown in Table 1 by weight, and physically dry-mixed for 1 hour to obtain a mixture. The mixture was added to a mold and sintered for the first time in a nitrogen atmosphere according to the temperature, pressure, and time shown in Table 1 to obtain a blocky first sintered product. This product was then wet-milled in a ball mill at 3000 rpm for 2 hours, with zirconium beads of 1-10 mm particle size. After ball milling, the product was dried to obtain primary particles. The primary particles were then placed in a high-temperature furnace and sintered for the second time in a nitrogen atmosphere according to the temperature and time shown in Table 1. The sintered product was then wet-milled in a ball mill at 3000 rpm for 1-5 hours, with zirconium beads of 1-10 mm particle size. After ball milling, the product was dried to obtain modified boron nitride particles. The preparation of modified boron nitride particles of different particle sizes was achieved by controlling the second ball milling time.

[0100] Table 1

[0101]

[0102]

[0103] In Table 1, the amounts of boron nitride (BN), sintering aids, and other metal oxides are expressed in "parts" (parts by mass), with "--" indicating that the component was not added. In Preparation Example 7, only the first sintering was performed. The product obtained from the first sintering was crushed to obtain modified boron nitride particles G.

[0104] The average particle size of the modified boron nitride particles in Table 1 was determined by laser diffraction. The testing instrument was a Malvern laser particle size analyzer, model MS3000.

[0105] The resin composition and its application described in this invention will be described in detail below with reference to several embodiments, but the resin composition and its application are not limited to these embodiments.

[0106] In the following examples, materials for which no preparation method is provided are commercially available chemicals, as detailed in the table below:

[0107] category source Polybutadiene resin, B3000 Japanese Soda Polyphenylene ether resin, SA9000 Sabik Epoxy Resin A, ZX1059 Nippon Steel Brominated epoxy resin, BEB531A80P Changchun, Taiwan, China Phenoxy resin, YP-50EK35 Nippon Steel Initiator: 1,4-Bis(tert-butylperoxyisopropyl)benzene (BIPB) Hunan Fangruida Chemical Co., Ltd. Accelerator: 2-Methylimidazole (2-MI) BASF Modified boron nitride particles AG Preparation Examples 1-7

[0108] Examples 1-6, Comparative Examples 1-4

[0109] A resin composition, the types and amounts of each component are shown in Table 2, and the unit of amount of each component is "parts" (parts by mass).

[0110] A prepreg comprising the resin composition and a copper-clad laminate are prepared by the following method:

[0111] (1) Mix and disperse each component of the resin composition with solvent (ethylene glycol methyl ether) according to the formula amount to prepare a glue solution with a solid content of 80%; impregnate the glue solution with fiberglass cloth and bake it in an oven at 155°C for 5 minutes to obtain a prepreg with a thickness of 5 mil.

[0112] (2) Six prepreg sheets are stacked together, copper foil is stacked on both sides, and the copper-clad laminate is laminated and cured at 210°C and 5MPa pressure for 2 hours in a hot press to obtain the copper-clad laminate.

[0113] The copper-clad laminate was subjected to performance testing, and the specific method is as follows:

[0114] (1) Thermal conductivity: The thermal conductivity of the sheet was tested according to the test method in standard ASTM-D5470;

[0115] (2) Peel strength: The peel strength of the board was tested according to the test conditions in IPC-TM-650 2.4.8.

[0116] The performance test data is shown in Table 2.

[0117] Table 2

[0118]

[0119]

[0120] According to the performance test data in Table 2, the present invention mixes boron nitride with sintering aids of specific components and amounts, and then performs two sintering and crushing processes. Through the design of the preparation method, the modified boron nitride particles have a significantly improved filling rate. When compounded with resin materials, the resin composition and the copper-clad laminate prepared using it have high thermal conductivity and high peel strength. Among them, the thermal conductivity of Examples 1-4 is 5.6-15.7 W / m·K, and the peel strength is 0.8-1.49 N / mm, which shows excellent comprehensive performance.

[0121] In Example 5, the amount of modified boron nitride particles was too small, resulting in a decrease in the thermal conductivity of the copper-clad laminate; in Example 6, the amount of modified boron nitride particles was too large, which led to poor processability of the composition and made it impossible to prepare a qualified product.

[0122] A comparison of Example 2 with Comparative Examples 1-4 reveals that the modified boron nitride particles E in Comparative Example 1 used too little sintering aid, resulting in an insignificant modification effect. Consequently, the modified boron nitride particles E could not achieve a high filling ratio, leading to poor processability and the inability to produce a qualified product. Similarly, unmodified boron nitride filler was used in Comparative Example 4, which also failed to achieve high filling and produce a qualified product. The modified boron nitride particles F in Comparative Example 2 used excessive sintering aid, affecting the thermal conductivity of the material and significantly reducing the thermal conductivity of the substrate. The modified boron nitride particles G in Comparative Example 3 underwent only one sintering process, resulting in a less effective modification compared to the two-sintering process of this invention, leading to a decrease in the thermal conductivity of the resin composition containing them and the copper-clad laminate.

[0123] The applicant declares that the above embodiments illustrate the resin composition, metal foil laminate, and their applications, but the present invention is not limited to the above embodiments, i.e., it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product, addition of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A resin composition, characterized in that, The resin composition comprises a combination of resin material and modified boron nitride particles; The modified boron nitride particles are prepared by the following method, which includes: mixing boron nitride and a sintering aid, and then subjecting the mixture to a first sintering and a first crushing to obtain primary particles; and subjecting the primary particles to a second sintering and a second crushing to obtain the modified boron nitride particles. The first sintering temperature is 300-700℃, the pressure is 1-10 GPa, and the time is 1-8 h; The second sintering temperature is 700-1500℃, and the time is 2-8 h; The sintering aid includes any one or a combination of at least two of calcium oxide, magnesium oxide, silicon oxide, yttrium oxide, niobium oxide, and potassium feldspar; the sintering aid comprises 1-10% of the total mass of boron nitride and the sintering aid, which is 100% of the total mass. The modified boron nitride particles in the resin composition have a mass percentage content of 30-92%. Both the first and second sintering processes were carried out in an inert atmosphere.

2. The resin composition according to claim 1, characterized in that, The modified boron nitride particles have an average particle size of 0.1-30 μm.

3. The resin composition according to claim 1, characterized in that, The modified boron nitride particles in the resin composition comprise 50-90% by mass.

4. The resin composition according to claim 1, characterized in that, The mixed raw materials also include other metal oxides; The other metal oxides include aluminum oxide and / or beryllium oxide; The total mass of the boron nitride, sintering aid, and other metal oxides is 100%, and the mass of the other metal oxides is 1-10%.

5. The resin composition according to claim 1, characterized in that, The inert atmosphere includes a nitrogen atmosphere and / or an argon atmosphere.

6. The resin composition according to claim 1, characterized in that, The resin material includes any one or a combination of at least two of the following: epoxy resin, cyanate ester resin, polyphenylene ether resin, polybutadiene resin, styrene-butadiene resin, bismaleimide-triazine resin, bismaleimide resin, polytetrafluoroethylene resin, polyimide resin, phenolic resin, phenolic oxy resin, acrylic resin, liquid crystal resin, benzoxazine resin, and nitrile rubber.

7. The resin composition according to claim 1, characterized in that, The resin composition contains 8-70% resin material by mass.

8. The resin composition according to claim 7, characterized in that, The resin composition contains 8-50% resin material by mass.

9. The resin composition according to claim 1, characterized in that, The resin composition further includes any one or a combination of at least two of the following: accelerator, initiator, crosslinking agent, filler, flame retardant, and curing agent.

10. The resin composition according to claim 9, characterized in that, The promoter includes any one or a combination of at least two of imidazole compounds, organic complexes, tertiary amines, tertiary phosphine, and quaternary ammonium salts.

11. The resin composition according to claim 10, characterized in that, The accelerator is an imidazole compound.

12. The resin composition according to claim 11, characterized in that, The imidazole compounds include any one or a combination of at least two of the following: 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-2-methylimidazole, 2-heptadecylimidazole, 2-isopropylimidazole, 2-phenyl-4-methylimidazole, 2-dodecylimidazole, and 1-cyanoethyl-2-methylimidazole.

13. The resin composition according to claim 9, characterized in that, The accelerator in the resin composition has a mass percentage of ≤8%.

14. The resin composition according to claim 9, characterized in that, The initiator includes any one or a combination of at least two of the following: organic peroxides, azo initiators, and carbon-based initiators.

15. The resin composition according to claim 14, characterized in that, The organic peroxides include any one or a combination of at least two of the following: α,α'-di(tert-butylperoxym-isopropylbenzene), diisopropylbenzene peroxide, tert-butylperoxym-isopropylbenzene, 1,1-bis(tert-hexylperoxy)-3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hex-3-yne, tert-butyl peroxyoctanoate, and tert-butyl peroxybenzoate.

16. The resin composition according to claim 9, characterized in that, The initiator in the resin composition has a mass percentage content of ≤8%.

17. The resin composition according to claim 9, characterized in that, The crosslinking agent includes any one or a combination of at least two of the following: triallyl isocyanurate, polytriallyl isocyanurate, triallyl cyanurate, trimethacrylic acid, diallyl phthalate, divinylbenzene, and polyfunctional (meth)acrylates.

18. The resin composition according to claim 9, characterized in that, The crosslinking agent in the resin composition has a mass percentage of ≤20%.

19. The resin composition according to claim 9, characterized in that, The filler comprises any one or a combination of at least two of the following: silicon dioxide, titanium dioxide, barium titanate, strontium titanate, magnesium titanate, calcium titanate, barium strontium titanate, barium calcium titanate, lead titanate, lead zirconate titanate, lanthanum lead zirconate titanate, barium lanthanum titanate, barium zirconate titanate, hafnium dioxide, lead magnesium niobate, barium magnesium niobate, lithium niobate, potassium niobate, strontium aluminum tantalate, potassium tantalate, barium strontium niobate, barium barium niobate, barium titanium barium niobate, strontium bismuth tantalate, bismuth titanate, rubidium barium titanate, copper titanate, and lead titanate-lead magnesium niobate.

20. The resin composition according to claim 9, characterized in that, The filler content in the resin composition is ≤20% by mass.

21. A prepreg, characterized in that, The prepreg comprises a reinforcing material and a resin composition as described in any one of claims 1-20 attached to the reinforcing material.

22. The prepreg according to claim 21, characterized in that, The resin composition is attached to the reinforcing material after impregnation and drying.

23. A thermally conductive film, characterized in that, The material of the thermally conductive film includes the resin composition as described in any one of claims 1-20.

24. The thermally conductive film according to claim 23, characterized in that, The thermally conductive film is prepared by coating the resin composition onto a release material and then drying and / or semi-curing it.

25. A metal foil-coated laminate, characterized in that, The metal foil laminate includes a metal foil and at least one of the prepreg as described in claim 21 or 22 and the thermally conductive film as described in claim 23 or 24.

26. A printed circuit board, characterized in that, The printed circuit board includes at least one of the prepreg as described in claim 21 or 22, the thermally conductive film as described in claim 23 or 24, and the metal foil laminate as described in claim 25.

Images