Laminate

Abstract

The present invention provides a laminate capable of sufficiently suppressing foreign matter when a substrate is peeled off. This laminate includes a substrate and a resin composition layer formed on the substrate. The resin composition layer contains inorganic particles, an epoxy resin, and a silane coupling agent, and has a thickness of 0.10 mm to 1.00 mm. The percentage of the inorganic particles with respect to the solid content of the resin composition layer is 50 mass% to 99 mass%. The cumulative 50% particle diameter D50 of the inorganic particles is 10 μm or less from the fine grain side of a cumulative particle size distribution based on volume. The silane couple agent is such that the polarity term of the Hansen solubility parameter is 2 to 10.

Description

Laminate

[0001] The present invention relates to a laminate, and in particular to a laminate for use in sealing materials.

[0002] In the semiconductor field, chips are protected by sealing materials made of resin and filler to ensure reliability. In recent years, from the viewpoint of ease of handling, the use of laminates in which a resin composition layer containing inorganic particles and a resin is formed in a sheet shape on a substrate has been considered as sealing materials for electronic components. The handleability of such laminates is improved by including a substrate before application to various electronic components. Such sealing materials may generally contain inorganic particles and a resin, as described in Patent Document 1.

[0003] Japanese Patent Application Laid-Open No. 2021-145117

[0004] When the sheet-like laminate is applied to various electronic components, the substrate can be peeled off and only the resin composition layer required for sealing can be used. However, as a result of studies by the present inventors, it was found that in the laminate described above, when the substrate is peeled off, a problem occurs in that a portion of the surface of the resin composition layer is damaged, resulting in a decrease in sealing properties. Therefore, an object of an embodiment of the present invention is to provide a laminate that can sufficiently suppress damage when the substrate is peeled off.

[0005] Aspect 1 of the present invention is a laminate including a substrate and a resin composition layer formed on the substrate, wherein the resin composition layer includes inorganic particles, an epoxy resin, and a silane coupling agent, and has a thickness of 0.10 mm or more and 1.00 mm or less, a ratio of the inorganic particles to the solid content of the resin composition layer is 50 mass % or more and 99 mass % or less, a particle diameter D50 of the inorganic particles at 50% cumulative from the fine particle side of a cumulative particle size distribution on a volume basis is 10 μm or less, and the silane coupling agent has a polarization term dP of Hansen solubility parameter of 2 or more and 10 or less.

[0006] Aspect 2 of the present invention is characterized in that the silane coupling agent is represented by formula (1): X ３－ｎ Me ｎ-Si-Y (1) (wherein Me is a methyl group, X is a hydrolyzable group, Y is a monovalent organic group, and n is 0, 1, or 2).

[0007] In a third aspect of the present invention, the inorganic particles have an isolated OH group density of 0.5 / nm ２ The laminate according to aspect 1 or 2 is as described above.

[0008] A fourth aspect of the present invention is the laminate according to any one of the first to third aspects, wherein the inorganic particles are alumina particles.

[0009] A fifth aspect of the present invention is the laminate according to any one of the first to fourth aspects, further comprising a solvent.

[0010] A sixth aspect of the present invention is the laminate according to any one of the first to fifth aspects, wherein the mass ratio of the content of the silane coupling agent to the content of the inorganic particles is 1:0.0001 to 1:0.05.

[0011] According to an embodiment of the present invention, it is possible to provide a laminate that can sufficiently suppress damage when the substrate is peeled off.

[0012] The present inventors conducted extensive research to provide a laminate that can adequately suppress defects during substrate peeling. The inventors believed that defects were primarily caused by aggregates of inorganic particles. They then came up with the idea of ​​incorporating a silane coupling agent having a predetermined Hansen solubility parameter dP in addition to using specific inorganic particles and an epoxy resin. This improves the compatibility (mixability) of the inorganic particles and the epoxy resin via the silane coupling agent, thereby suppressing aggregation of the inorganic particles. As a result, a laminate was realized that can adequately suppress the generation of foreign matter during substrate peeling. The requirements of this embodiment are described in detail below.

[0013] [Laminate] The laminate according to this embodiment is a laminate including a substrate and a resin composition layer formed on the substrate, wherein the resin composition layer includes inorganic particles, an epoxy resin, and a silane coupling agent, and has a thickness of 0.10 mm or more and 1.00 mm or less, the proportion of the inorganic particles to the solid content of the resin composition layer is 50 mass % or more and 99 mass % or less, the inorganic particles have a particle diameter D50 of 10 μm or less at 50% cumulative from the fine particle side of a volume-based cumulative particle size distribution, and the silane coupling agent has a polarization term dP of 2 or more and 10 or less. The laminate can sufficiently suppress foreign matter when the substrate is peeled off.

[0014] In this embodiment, the substrate is preferably in the form of a film, and a general polymer film can be used. Examples of polymer films include polyolefin films such as polyethylene film and polypropylene film, vinyl films such as polyvinyl chloride film, polyester films such as polyethylene terephthalate film, polycarbonate film, acetyl cellulose film, and tetrafluoroethylene film. The thickness of the substrate is not particularly limited, but is preferably 20 to 200 μm from the viewpoint of excellent workability and drying properties. In one embodiment of the present invention, the laminate may also have a substrate attached to the surface of the resin composition layer opposite to the surface having the substrate.

[0015] In the present embodiment, the resin composition layer is formed on a substrate and contains inorganic particles, an epoxy resin, and a silane coupling agent. Each component of the resin composition layer will be described below.

[0016] The "resin composition layer" in the present invention has fluidity when heated and pressurized. Examples of the resin composition layer include an uncured resin composition (also referred to as an A-stage resin composition) layer and a resin composition obtained by semi-curing an uncured resin composition layer (also referred to as a B-stage resin composition). When a solvent is contained in the resin composition layer, for example, an uncured (A-stage) resin composition layer can be obtained by applying a liquid resin composition to a substrate or the like and then removing a portion of the solvent by evaporation or the like. Furthermore, as described below, a B-stage resin composition layer can be obtained by semi-curing the resin by further removing the solvent from the uncured (A-stage) resin composition layer.

[0017] In one embodiment of the present invention, the resin composition layer may contain a solvent. When the resin composition layer contains a solvent, it is easy to flow, can be easily deformed to fit the fine structure of the IC chip and the substrate, and can seal the dense structure without gaps. Known solvents can be used as the solvent, and are not limited as long as they can dissolve the epoxy resin. Examples of the solvent include alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, amine-based solvents, amide-based solvents, halogen-based solvents, hydrocarbon-based solvents, and nitrile-based solvents. From the viewpoint of being a good solvent for the epoxy resin and providing excellent coatability for the resulting resin composition, the resin composition preferably contains one or more solvents selected from the group consisting of ketone-based solvents and ester-based solvents.

[0018] Examples of ketone solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone, and examples of ester solvents include methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, normal propyl acetate, amine acetate, sec-butyl acetate, etc. The resin composition layer preferably contains one or more solvents selected from the group consisting of methyl ethyl ketone, cyclopentanone, and cyclohexanone.

[0019] The amount of solvent in the uncured resin composition layer and the semi-cured resin composition layer is 0.001% by mass or more, preferably 10% by mass or less, relative to the mass of the entire resin composition layer. When the amount of solvent is within this range, the fluidity is good when heated and pressurized, and aggregation and sedimentation of inorganic particles are prevented, making it easy to improve sealing properties. The semi-cured resin composition layer can be produced, for example, by further drying the uncured resin composition layer, reducing the amount of solvent by heating and pressurizing, or reacting an epoxy resin. In the present invention, the amount of solvent in the semi-cured resin composition layer is less than the amount of solvent in the uncured resin composition layer. The amount of solvent in the resin composition layer can be determined, for example, from the change in mass of the resin composition layer before and after heating, such as drying, and specifically, by the method described in the Examples below.

[0020] [Inorganic Particles] In this embodiment, inorganic particles are contained in the resin composition layer. The inclusion of inorganic particles reduces the dimensional change rate of the entire resin composition layer, making peeling, cracks, and the like less likely to occur after semiconductor chip encapsulation, thereby improving reliability. Ceramics such as silica, alumina, aluminum nitride, boron nitride, silicon nitride, and silicon carbide are preferred as inorganic particles. In particular, alumina or silica is preferred from the viewpoint of dimensional stability of the resin composition layer, and alumina, aluminum nitride, boron nitride, silicon nitride, and silicon carbide are preferred from the viewpoint of thermal conductivity of the resin composition layer. Since ceramics have high thermal conductivity, the use of ceramic particles can improve the heat dissipation performance of the resin composition layer. Furthermore, when insulating ceramics are used as inorganic particles, short circuits in the semiconductor device can be suppressed. Therefore, it is more preferable that the inorganic particles be insulating ceramic particles, specifically alumina, aluminum nitride, boron nitride, or silicon nitride. Among these, alumina is even more preferred from the viewpoint of achieving both thermal dimensional stability and thermal conductivity of the resin composition layer.

[0021] When alumina is selected as the inorganic particles, they can be produced by known methods, such as the Bayer method, the ammonium alum method, the ammonium aluminum carbonate hydroxide method (AACH method), the solvent extraction method, the organoaluminum hydrolysis method (aluminum alkoxide method), and melt growth methods such as the CZ method, the Verneuil method, the chiroporous method, the Bridgman method, and the EFG method.

[0022] In the Bayer process, raw alumina can be produced by calcining aluminum hydroxide obtained from bauxite. The ammonium alum process, the AACH process, the solvent extraction process, and the aluminum alkoxide process are also preferred because they allow the production of high-purity raw alumina with low contents of uranium and thorium, which can have adverse effects on electronic components.

[0023] (Particle size distribution of inorganic particles) The particle diameter of the inorganic particles is 10 μm or less, where D50 is the cumulative 50% particle diameter from the fine particle side of the cumulative particle size distribution based on volume of the inorganic particles (hereinafter, simply referred to as "D50"). This can improve the sealing property of the resin composition layer, particularly the filling ability into narrow wiring spaces. The D50 of the inorganic particles is preferably 5.5 μm or less, more preferably 5.0 μm or less, and even more preferably 3.0 μm or less. From the viewpoint of achieving good dispersibility in the epoxy resin and easily suppressing damage during substrate peeling, the D50 of the inorganic particles is preferably 0.5 μm or more, more preferably 1.0 μm or more, and even more preferably 1.5 μm or more. Controlling the particle diameter to less than 0.5 μm makes it difficult to spheroidize, which may result in a decrease in roundness. Furthermore, depending on the object to be encapsulated, particles with a D50 of more than 10 μm may not be able to fill narrow areas during the encapsulation process.

[0024] The D50 of the inorganic particles can be determined by measuring the particle size distribution of the inorganic particles by laser diffraction using, for example, a laser particle size distribution measuring device such as a "Microtrac MT3300EXII" manufactured by Microtrac Bell Co., Ltd. The particle size measurement of the inorganic particles in the resin composition layer can be performed by removing the resin contained in the resin composition layer, for example, by dissolving it in an organic solvent or by heating it to a temperature of 500°C or higher to pyrolyze the resin, and isolating only the inorganic particles, and using the inorganic particles.

[0025] In order to easily obtain inorganic particles of a desired size, a pulverization step may be included in the production process. The pulverization of inorganic particles can be carried out by a known method such as a vibration mill, a bead mill, a ball mill, or a jet mill, and may be carried out in either a dry or wet state.

[0026] (Average circularity of inorganic particles) The inorganic particles are preferably spherical, and the average circularity is preferably 0.80 or more and 0.99 or less, more preferably 0.90 or more and 0.95 or less. When the average circularity of the inorganic particles is within the above range, the filling rate of the inorganic particles in the epoxy resin is easily increased, and sedimentation in the resin composition is less likely to occur, improving dispersibility, thereby achieving good sealing properties. When the average circularity of the inorganic particles is high, the kneading ability with the epoxy resin is also improved, which also has the effect of increasing the fluidity of the resin composition after kneading and making it easier to form into a sheet.

[0027] Circularity (SPHT) can be analyzed in accordance with ISO 9276-6. SPHT = 4πA / P ２ where A is the measured value of the area of ​​the projected particle image, and P is the measured value of the perimeter of the projected particle image. The average circularity of the inorganic particles is measured using a measuring device based on the principle of dynamic image analysis in accordance with ISO 13322-2 (for example, a CAMSIZER X2 (manufactured by VERDER Scientific)). The average circularity of the inorganic particles in the resin composition layer can be measured by removing the epoxy resin or the like contained in the resin composition layer, for example, by dissolving it in an organic solvent or by heating it to a temperature of 500°C or higher to cause thermal decomposition, and isolating only the inorganic particles, and using the inorganic particles.

[0028] (BET specific surface area of ​​inorganic particles) The inorganic particles are preferably spherical particles from the viewpoint of fluidity with the resin, and the BET specific surface area measured by the nitrogen adsorption method is preferably 0.2 m, although it depends on the average particle size. ２ / g or more 10m ２ / g or less, more preferably 0.2m ２ / g or more 5m ２ / g or less, more preferably 0.3m ２ / g or more 3m ２ / g or less, and even more preferably 0.35m ２ / g or more 1m ２ By adjusting the amount of the resin composition to this range, the fluidity of the resin composition after kneading can be increased, and the sealing property of the resulting resin composition layer can be improved.

[0029] The BET specific surface area is measured in accordance with JIS-Z8830 (2013). When inorganic particles are contained in the resin composition layer, the resin contained in the resin composition layer can be removed by, for example, dissolving it in an organic solvent or by heating it to a temperature of 500°C or higher to thermally decompose the resin, thereby isolating only the inorganic particles, and the specific surface area can be measured using the inorganic particles.

[0030] Flame fusion is a suitable method for producing inorganic particles having the desired roundness and BET surface area. Flame fusion is a method in which a raw material (e.g., alumina) is sprayed into a flame, turned into droplets, and then cooled and solidified. Flame fusion allows inorganic particles to be obtained while maintaining the particle size of the inorganic particles. In the flame fusion, the temperature of the flame fusion furnace is preferably 1000°C or higher. In particular, in the flame fusion, by setting the raw material supply rate to 50 kg / h or less, preferably 10 kg / h or less, the amount of thermal energy applied to the inorganic particles can be controlled within a predetermined range, making it easier to obtain inorganic particles that satisfy the above-mentioned predetermined requirements.

[0031] After the flame melting, the inorganic particles are collected by a cyclone and / or a bag filter and classified to obtain inorganic particles having desired properties.

[0032] After classification, the inorganic particles obtained may be immersed in an acidic solution such as hydrochloric acid. This modifies the surface of the inorganic particles and further increases the number of isolated OH groups, as described below. The type of acidic solution used for immersion is preferably hydrochloric acid, as this facilitates concentration adjustment. The concentration of the acidic solution is preferably 1 M to 12 M, more preferably 1 M to 10 M, and even more preferably 2 M to 5 M. The mass ratio during immersion, inorganic particles to acidic solution, is preferably 1:2 to 1:10. The immersion time is preferably 5 hours or longer. During immersion, heating may be performed as appropriate to shorten the immersion time, for example, heating to 50 to 90°C. After immersion, washing and drying are preferably performed.

[0033] The number of isolated OH groups in inorganic particles is 0.5 / nm ２ It is preferable that the number of particles is 0.9 / nm or more. ２ More preferably, 2.0 particles / nm ２ The above is more preferable. This can strengthen the interaction with the silane coupling agent, and as a result, the compatibility between the inorganic particles and the epoxy resin can be further improved via the silane coupling agent. Furthermore, it is easier to obtain a laminate with a good appearance. On the other hand, the number of isolated OH groups is 3.0 / nm ２ This makes it easier to prevent the inorganic particles from aggregating with each other, and also makes it easier to obtain a laminate with a good appearance.

[0034] The number of isolated OH groups in inorganic particles can be determined using the results of measurement by the Karl Fischer method (moisture vaporization-titration method) in accordance with JIS K 0068:2001 "Method for measuring moisture content in chemical products." The moisture detected in the Karl Fischer measurement can be considered to be derived from the OH groups of the inorganic particles, and the moisture detected when the temperature is raised from 550°C to 900°C over 30 minutes can be considered to be moisture derived from isolated OH groups. When inorganic particles are contained in a resin composition, the measurement can be performed by separating the inorganic particles by dissolving the resin in an organic solvent or the like. The moisture detected in the Karl Fischer measurement is considered to be the condensation of two OH groups into one water molecule, and the number of OH groups can be calculated using the following formula (2): Number of OH groups [number / nm２ ] = 0.0662 × (water content [ppm]) / (specific surface area of ​​inorganic particles [m ２ / g])...(2)

[0035] In this embodiment, the resin composition layer contains an epoxy resin, which has high dimensional stability against external energy such as stress and heat, and is therefore thought to facilitate the production of a laminate that can suppress damage when the substrate is peeled off. Examples of epoxy resins include bisphenol A type epoxy resins, bisphenol AP type epoxy resins, bisphenol AF type epoxy resins, bisphenol B type epoxy resins, bisphenol BP type epoxy resins, bisphenol C type epoxy resins, bisphenol E type epoxy resins, bisphenol F type epoxy resins, bisphenol G type epoxy resins, bisphenol M type epoxy resins, bisphenol S type epoxy resins, bisphenol P type epoxy resins, bisphenol PH type epoxy resins, bisphenol TMC type epoxy resins, bisphenol Z type epoxy resins, bisphenol S type epoxy resins such as hexanediol bisphenol S diglycidyl ether, novolac phenol type epoxy resins, biphenyl type epoxy resins, naphthalene type epoxy resins, dicyclopentadiene type epoxy resins, bixylenol type epoxy resins such as bixylenol diglycidyl ether, hydrogenated bisphenol A type epoxy resins such as hydrogenated bisphenol A glycidyl ether, and dibasic acid-modified diglycidyl ether type epoxy resins thereof, aliphatic epoxy resins, and phenylcyclohexyl type epoxy resins. Preferred epoxy resins include phenylcyclohexyl-type epoxy resins, naphthalene-type epoxy resins, phenol-type epoxy resins, biphenyl-type epoxy resins, and bisphenol A-type epoxy resins. Furthermore, from the viewpoint of thermal conductivity, among these, epoxy resins having a mesogenic group (sometimes referred to as mesogenic epoxy resins) are more preferred, and epoxy resins having a mesogenic group that exhibit a phase transition temperature in the temperature range of 100°C to 200°C and exhibit liquid crystallinity are even more preferred. The resin contained in the resin composition layer may include one or more epoxy resins.That is, the resin contained in the resin composition layer may include one or more epoxy resins selected from the group consisting of phenylcyclohexyl-type epoxy resins, naphthalene-type epoxy resins, phenol-type epoxy resins, biphenyl-type epoxy resins, and bisphenol A-type epoxy resins, and may further include a thermoplastic polyimide.

[0036] In this embodiment, the polarization term dP of the Hansen solubility parameter of the epoxy resin is not particularly limited, but is preferably 1 to 20, more preferably 5 to 15. The Hansen solubility parameter of the epoxy resin can be measured by the dissolving sphere method. The dissolving sphere method is a method for calculating the Hansen solubility parameter of a target substance, in which the target substance is dissolved or dispersed in a number of different solvents for which the Hansen solubility parameter has been determined, and the Hansen solubility parameter is determined through a solubility test to evaluate the solubility or dispersibility of the target substance in a specific solvent. The types of solvents used in the solubility test are preferably selected so that the total value of the dispersion term, polar term, and hydrogen bonding term of the HP of each solvent varies widely between solvents. More specifically, it is preferable to evaluate using preferably 10 or more, more preferably 15 or more, and even more preferably 17 or more solvents. Specifically, among the solvents used in the solubility test, a sphere with the smallest radius (solubility sphere) is found, such that all three-dimensional points of the solvent that dissolved or dispersed the target substance are contained within the sphere, and points of the solvent that did not dissolve the target substance are located outside the sphere, and the center coordinates of this sphere are used as the Hansen solubility parameter of the target substance. The solubility and dispersibility are evaluated by visually determining whether the target substance dissolved or dispersed in the solvent, respectively. The specific method of the solubility test is described in detail in the Examples section.

[0037] The dispersion term dD of the Hansen solubility parameter of the epoxy resin is preferably 10 or more, more preferably 12 or more, even more preferably 14 or more, still more preferably 15 or more, and preferably 25 or less, more preferably 20 or less. When dD is within the above range, the generation of foreign matter in the laminate when the substrate is peeled off is easily suppressed. Furthermore, the hydrogen bond term dH of the Hansen solubility parameter of the epoxy resin is preferably 5.0 or more, more preferably 5.5 or more, even more preferably 6.0 or more, and preferably 15 or less, more preferably 10 or less. When dH is within the above range, the generation of foreign matter in the laminate when the substrate is peeled off is easily suppressed.

[0038] In this embodiment, the ratio of inorganic particles to the solid content of the resin composition layer (also referred to as the "inorganic particle filling rate") is 50% by mass or more and 99% by mass or less. By setting the inorganic particle filling rate to 50% by mass or more, thermal conductivity can be improved. On the other hand, by setting the inorganic particle filling rate to 99% by mass or less, damage to the laminate when the substrate is peeled off can be easily suppressed. From the viewpoint of improving thermal conductivity and further suppressing damage when the substrate is peeled off, the inorganic particle filling rate is more preferably 92% by mass or less, even more preferably 90% by mass or less, particularly preferably 88% by mass or less, and preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more. In this embodiment, the solid content of the resin composition layer refers to what remains as solid content when the resin composition layer is heated, excluding components that evaporate or volatilize upon heating, such as the above-mentioned solvent. Even if a component is liquid at 25°C, if it is incorporated into the solid content of the resin composition layer when heated, it is included in the solid content.

[0039] The alumina filling rate can be determined, for example, by the following method. First, the sheet-shaped resin composition is heated to remove volatile components such as solvents, and then the mass of the sheet-shaped resin composition (corresponding to the mass of the "solid content") is measured. Next, the epoxy resin and other components contained in the sheet-shaped resin composition are removed, for example, by dissolving the composition in an organic solvent or by heating the composition to a temperature of 500°C or higher to cause thermal decomposition, and only the alumina particles are separated, and the mass of the alumina particles is measured. The alumina filling rate can be calculated using these measurement results. Alternatively, the alumina filling rate can be calculated from the amount of the sheet-shaped resin composition charged.

[0040] In this embodiment, the resin composition layer contains a silane coupling agent, and the polarization term dP of its Hansen solubility parameter is 2 or more and 10 or less. When dP is 2 or more, aggregation of inorganic particles can be effectively suppressed. The dP of the silane coupling agent is more preferably 3 or more, and even more preferably 3.5 or more. On the other hand, when dP is 10 or less, the compatibility between the inorganic particles and the epoxy resin can be sufficiently improved. The dP of the silane coupling agent is more preferably 9 or less, and even more preferably 8 or less. The silane coupling agent may be one type or two or more types.

[0041] The dispersion term dD of the Hansen solubility parameter of the silane coupling agent is preferably 10 or more, more preferably 12 or more, even more preferably 14 or more, still more preferably 15 or more, and preferably 25 or less, more preferably 20 or less, and even more preferably 18 or less. When dD is within the above range, the generation of foreign matter in the laminate when the substrate is peeled off is easily suppressed. Furthermore, the hydrogen bond term dH of the Hansen solubility parameter of the silane coupling agent is preferably 6.0 or more, more preferably 6.5 or more, even more preferably 7.0 or more, and preferably 15 or less, more preferably 10 or less. When dH is within the above range, the generation of foreign matter in the laminate when the substrate is peeled off is easily suppressed.

[0042] The Hansen solubility parameter of a silane coupling agent can be measured by the dissolved sphere method, similar to the Hansen solubility parameter of an epoxy resin.

[0043] As the silane coupling agent, a known agent having a polarization term dP of the Hansen solubility parameter of 2 or more and 10 or less can be used. In one embodiment of the present invention, the silane coupling agent can be represented by the following formula (1): X ３－ｎ Me ｎ —Si—Y (1) (wherein Me is a methyl group, X is a hydrolyzable group, Y is a monovalent organic group, and n is 0, 1, or 2)

[0044] In formula (1), X (hydrolyzable group) is, for example, a methoxy group (CH ３ O-), ethoxy group (CH ３ CH ２ O-), propoxy group (CH ３ CH ２ CH ２ O-), isopropoxy group ((CH ３ ) ２ CHO-), a chloro group, or a 2-methoxyethoxy group (CH ３ OCH ２ CH ２ From the viewpoint of easily coating inorganic particles, a methoxy group (CH ３ O-), ethoxy group (CH ３ CH ２ O—), and a methoxy group (CH ３ n is preferably 0 or 1, and more preferably 0.

[0045] In formula (1), Y is a monovalent organic group. Y is preferably an alkyl group having 1 to 20 carbon atoms which may have a vinyl group, epoxy group, phenyl group, styryl group, methacryl group, acrylic group, amino group, ureido group, mercapto group, or isocyanate group at the terminal, and a part of the carbon skeleton may be substituted with -O-, -NH-, -S-, -CO-, or -COO- as long as they are not adjacent. Among these, an unsubstituted alkyl group having 1 to 20 carbon atoms, or a vinyl group, a phenyl group, or an epoxy group is more preferred. In particular, an unsubstituted alkyl group having 1 to 20 carbon atoms is even more preferred. This enhances the dispersibility of the inorganic particles in the resin, and makes it easier to suppress aggregation between the inorganic particles.

[0046] In formula (1), Y is preferably a linear alkyl group having 1 to 20 carbon atoms, and the number of carbon atoms is preferably 2 or more, more preferably 5 or more, and even more preferably 8 or more. This makes it easier to obtain the effect of suppressing aggregation between inorganic particles due to steric hindrance of the silane coupling agent.

[0047] Examples of the silane coupling agent include decyltrimethoxysilane, tetramethoxysilane, vinyltrimethoxysilane, 7-octenyltrimethoxysilane, 8-glycidoxyoctyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, hexamethyldisilazane, phenyltrimethoxysilane, glycidoxyoctyltrimethoxysilane, 2-phenylethyl ... trimethoxysilane, 2,2-diphenylethyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-Methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, N-2(aminoethyl)3-aminopropylmethyldimethoxysilane, N-2(aminoethyl)3-aminopropyltrimethoxysilane, N-2(aminoethyl)3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-ditylidene)propylamine, N-phenyl Examples of suitable silane coupling agents include N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, 3-ureidopropyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltrimethoxysilane, bis(triethoxysilylpropyl)tetrasulfide, 3-isocyanatopropyltriethoxysilane, and hexamethyldisilazane. Among these, vinyl-based silane coupling agents are preferred because they tend to prevent aggregation of inorganic particles and increase tensile strength.

[0048] In this embodiment, the mass ratio of the silane coupling agent content to the inorganic particle content is preferably 1:0.0005 to 1:0.03, more preferably 1:0.001 to 1:0.02, and even more preferably 1:0.0015 to 0.01. When the mass ratio of the silane coupling agent content to the inorganic particle content is greater than these preferred lower limits, the surface modification of the inorganic particles tends to improve, and compatibility with the resin tends to improve. When the mass ratio is less than these preferred upper limits, self-condensation of the hydrolyzable groups remaining without bonding to the inorganic particle surface tends to be suppressed, thereby suppressing aggregation between the inorganic particles. This makes it easier to further improve the compatibility between the inorganic particles and the epoxy resin. Furthermore, it is easier to obtain a laminate with a good appearance.

[0049] The resin composition layer has a thickness of 0.10 mm or more and 1.00 mm or less. A thickness of 0.10 mm or more can prevent partial exposure of the IC chip or the occurrence of surface irregularities when sealing the IC chip. A thickness of 1.00 mm or less can reduce the heating time required for sufficient curing, resulting in a resin composition layer in which the inorganic particles are uniformly dispersed. The thickness is preferably 0.80 mm or less, more preferably 0.60 mm or less, even more preferably 0.40 mm or less, and preferably 0.13 mm or more, more preferably 0.15 mm or more, and even more preferably 0.20 mm or more. When the thickness of the resin composition layer is within the above range, the inorganic particles (especially particles with a small particle size) and the epoxy resin flow uniformly when heated and pressurized, making it less likely for voids to occur after sealing and curing, and therefore less likely to cause defects. Furthermore, aggregation and precipitation of inorganic particles (especially particles with a small particle size) caused by evaporation of solvent from the surface during storage in the atmosphere are less likely to occur, making it easier to maintain sealing properties over a long period of time.

[0050] The resin composition layer may contain, as needed, known additives, such as plasticizers, curing agents, curing accelerators, fillers, pigments, flame retardants, antioxidants, surfactants, compatibilizers, weathering agents, antiblocking agents, antistatic agents, leveling agents, and release agents, either singly or in combination, as long as the effects of the invention are not impaired. In one preferred embodiment of the present invention, the sheet-shaped resin composition contains alumina particles, an epoxy resin, a silane coupling agent, a solvent, and a curing agent. Examples of the curing agent include amine-based curing agents such as 4,4-diaminodiphenylmethane.

[0051] [Method for manufacturing laminate] The laminate according to the present embodiment can be obtained by mixing predetermined inorganic particles, an epoxy resin, and a silane coupling agent in a predetermined ratio using a commonly used known method, and then applying the mixture to a substrate (and drying it as necessary) to form a resin composition layer on the substrate. The mixing method is not particularly limited, and a mill, a mixer, an agitating blade, or the like can be used.

[0052] One example of a method for producing a laminate is to use a commonly used known method to first mix alumina particles and a silane coupling agent in a predetermined ratio, then mix an epoxy resin, a solvent, and a curing agent, and then apply the resulting mixture to a substrate. The solvent is then mostly removed by hot air drying or the like to form a resin composition layer on the substrate. The method for applying the mixture is not particularly limited, and coating devices such as a comma coater, lip coater, roll coater, gravure coater, die coater, and spin coater can be used. Known curing agents can be used, and known mixing and curing methods can be used.

[0053] The present embodiment will be described in detail below with reference to examples carried out to clarify the effects of the present embodiment, but the present embodiment is not limited to the following examples.

[0054] [Preparation of Alumina Particles A0] High-purity aluminum metal obtained by the method described in JP 2010-106329 A was prepared as a raw material. Aluminum hydroxide was obtained from the aluminum metal by a sol-gel method by the method described in JP 2018-048060 A, and then the aluminum hydroxide was calcined to obtain an alumina raw material.

[0055] Next, using a jet mill pulverizer (horizontal jet mill pulverizer PJM-280SP manufactured by Nippon Pneumatic Mfg. Co., Ltd.), the alumina raw material was treated under the conditions of a feed rate of 30 kg / h and a gauge pressure at the air supply port during pulverization of 0.5 MPa, to obtain alumina raw material particles having an average particle size of secondary particles of about 2 μm.

[0056] The obtained alumina raw material particles were charged into a flame melting furnace and melted to obtain spherical alumina particles. The atmospheric temperature in the flame melting furnace was set to 1250°C, and the raw material supply rate was set to 5 kg / h. The obtained alumina particles were recovered using a cyclone and subjected to classification by cyclone classification to remove particles of 5 μm or larger, thereby obtaining alumina particles A0 (D50 = 2.6 μm). In the examples, the D50 of the alumina particles was measured by laser diffraction using a laser particle size distribution analyzer "Microtrac MT3300EXII" manufactured by Microtrac Bell Co., Ltd.

[0057] [Preparation of Alumina Particles A] As the raw alumina, γ-alumina obtained by the ammonium alum method (the average particle diameter of the primary particles calculated from the value of the BET specific surface area described below was 13 nm) was used. The BET specific surface area of ​​this γ-alumina measured by the nitrogen adsorption method was 120 m ２ Before pulverization, 4 mass % of propylene glycol was added as a surface protective agent to the raw alumina and mixed.

[0058] Next, using a jet mill pulverizer (horizontal jet mill pulverizer PJM-280SP manufactured by Nippon Pneumatic Mfg. Co., Ltd.), the alumina raw material was treated under the conditions of a feed rate of 30 kg / h and a gauge pressure at the air supply port during pulverization of 0.5 MPa, to obtain alumina raw material particles having an average particle size of secondary particles of about 2 μm.

[0059] The resulting alumina raw material particles were charged into a flame fusion furnace and melted to obtain spherical alumina particles. The ambient temperature in the flame fusion furnace was set to 1250°C, and the raw material feed rate was set to 5 kg / h. The resulting alumina particles were collected in a cyclone and classified by cyclone classification to remove particles with a size of 5 μm or more, thereby obtaining alumina particles A (D50 = 2.3 μm).

[0060] [Preparation of Alumina Particles B2] The same alumina raw material particles as those used for preparing alumina particles A were placed in a flame melting furnace and melted to obtain spherical alumina particles. The ambient temperature in the flame melting furnace was set to 1,250°C, and the raw material supply rate was set to 5 kg / h. The obtained alumina particles were recovered using a cyclone and classified by cyclone classification to remove particles with a size of 10 μm or more, thereby obtaining alumina particles B (D50 = 5.1 μm).

[0061] The obtained alumina particles B were immersed in 2 M hydrochloric acid. The mass ratio of alumina particles to hydrochloric acid during immersion was 1:5, the temperature during immersion was 80°C, and the immersion time was 12 hours. After immersion, the particles were immersed in water multiple times. The immersion in water was repeated, replacing the water each time, until the water after immersion became neutral. After removing the water, the particles were left to stand at 80°C for 6 hours and dried to obtain alumina particles B2.

[0062] The following measurements were carried out on each alumina particle.

[0063] [Number of Isolated OH Groups in Alumina Particles] The number of isolated OH groups in alumina particles was determined using the measurement results by the Karl Fischer method (moisture vaporization-titration method) in accordance with JIS K 0068:2001 "Method for measuring moisture content in chemical products." The moisture detected in the Karl Fischer measurement was considered to be derived from the OH groups of the alumina particles, and the moisture detected at a temperature of 900°C was considered to be derived from isolated OH groups. Note that the moisture detected in the Karl Fischer measurement is considered to be derived from two OH groups condensing to form one water molecule, and the number of OH groups was calculated by the following formula (2): Number of OH groups [number / nm ２ ] = 0.0662 × (water content [ppm]) / (specific surface area of ​​alumina particles [m ２ / g])...(2)

[0064] [Preparation of each silane coupling agent] KBM-3103, KBM-1003, KBM-1083, KBM-4803, and KBM-403 (all manufactured by Shin-Etsu Chemical Co., Ltd.) were prepared as silane coupling agents. Silane coupling agent A and silane coupling agent B represented by the following structural formulas were also prepared. Silane coupling agent A (2-phenylethyltrimethoxysilane):

[0065] Silane coupling agent B (2,2-diphenylethyltrimethoxysilane):

[0066]

[0067] The Hansen solubility parameter of each silane coupling agent was measured using the dissolving sphere method as follows. A mixture was prepared by adding 1 mL of a solvent with a known solubility parameter (as shown in Table 1) (source: Polymer Handbook, 4th Edition) and 1 mL of the target silane coupling agent to a transparent container. The resulting mixture was shaken, and the appearance of the liquid was visually observed. The solubility of the target silane coupling agent in the solvent was evaluated based on the observation results using the following evaluation criteria. A rating of 1 or 2 indicated that the solvent dissolved the test sample, and a rating of 0 indicated that the solvent did not dissolve the test sample. (Evaluation Criteria) 2: The appearance of the mixture is translucent. 1: The appearance of the mixture is colorless and transparent. 0: The appearance of the mixture is cloudy or separated.

[0068]

[0069] Based on the evaluation results of the solubility of the target silane coupling agent in the solvent, a Hansen sphere was created using the above-mentioned Hansen dissolved sphere method. The central coordinates of the obtained Hansen sphere were taken as the HSP value. The results are shown in Table 2.

[0070]

[0071] [Preparation of Each Epoxy Resin] As epoxy resins, a mesogenic epoxy resin (phenylcyclohexyl type epoxy resin) (A) (hereinafter also referred to as "ME") and a bisphenol A type epoxy resin (ADEKA, EP-4100HF) (hereinafter also referred to as "BisA") were prepared. Similarly to the silane coupling agents, the solubility parameters of each epoxy resin were also measured by the dissolved sphere method. The dD, dP, and dH of ME were 16.7, 7.7, and 8.6, respectively, and the dD, dP, and dH of BisA were 17.8, 10.5, and 6.6, respectively. Here, the mesogenic epoxy resin (A) is a prepolymer obtained by reacting trans-4-{4-(2,3-epoxypropoxy)phenyl}cyclohexyl 4-(2,3-epoxypropoxy)benzoate (an epoxy resin represented by the structural formula below) with 6-hydroxy-2-naphthoic acid.

[0072]

[0073] <Preparation of Laminate> Laminates of Examples 1 to 12 and Comparative Examples 1 to 5 were prepared by mixing (kneading) each alumina particle, each silane coupling agent (hereinafter sometimes referred to as "SC agent"), each epoxy resin, and each curing agent in a predetermined ratio as shown in Table 3 below. The detailed preparation method is shown below.

[0074] (1) Silane Coupling Agent Treatment The following treatment was carried out to fix the silane coupling agent to the alumina particle surface. 50 g of alumina particles were mixed with 20 g of isopropanol to prepare a slurry. 0.5% by mass of silane coupling agent relative to the alumina particles was added to the prepared slurry, and 0.02 g of formic acid was further added, followed by stirring for 30 minutes. 0.2 g of 10% by mass ammonia water was then added, followed by stirring for 60 minutes. The stirred slurry was heated at 120°C for 3 hours to remove the solvent, thereby obtaining alumina particles treated with a silane coupling agent.

[0075] The alumina particles treated with the silane coupling agent were subjected to thermogravimetric analysis using a simultaneous differential thermal analyzer (NEXTA STA200, Hitachi High-Tech), and the mass loss rate from the initial mass when the temperature was increased from 60°C to 500°C at a rate of 10°C / min was defined as the mass ratio of the silane coupling agent content to the alumina particles.

[0076] (2) Preparation of Varnish: The epoxy resin was dissolved in a mixed solvent of methyl ethyl ketone and cyclopentanone (mass ratio 3:1) to prepare a 30% by mass mixed solution. Furthermore, 4,4-diaminodiphenylmethane (manufactured by TCI) was added as a curing agent in an amount of 4.14% by mass relative to 100% by mass of the mixed solution to prepare a varnish.

[0077] (3) Preparation of Alumina Particle / Varnish Mixture Alumina particles treated with a silane coupling agent (or alumina particles not treated with a silane coupling agent) were added to the obtained varnish, and the mixture was kneaded at 2000 rpm for 60 seconds using a planetary centrifugal mixer (manufactured by Thinky Corporation) to prepare an alumina particle / varnish mixture.

[0078] (4) Film Formation and Drying The resulting alumina particle / varnish mixture was applied to a PET substrate and formed into a film using an applicator to a thickness of 300 μm after drying. The film was then heated at 65°C for 5 minutes and then 100°C for 15 minutes to remove the solvent, yielding a laminate including a substrate and a resin composition layer (uncured) formed on the substrate. The solvent content of the resin composition layer (uncured) was 0.1 to 3% by mass. The solvent content of the resin composition layer was determined by the following measurement. A 4 cm square sample was cut from the resin composition layer of each Example and Comparative Example, along with the PET substrate, and the mass W1 (g) of the sample (with PET substrate) was measured. Next, the sample was heated at 150°C for 10 minutes in a full exhaust oven to evaporate all of the solvent contained in the sample. The sample was then left at room temperature for 5 minutes, and the temperature was returned to room temperature. The mass W2 (g) of the heated sample (with PET substrate) was measured. The PET substrate was peeled from the heated sample, and the mass W3 (g) of the PET substrate was measured. The mass of the sample before and after heating was determined by subtracting W3 (g) from W1 (g) and W2 (g), respectively. The mass of the sample after heating (W2-W3) was subtracted from the mass of the sample before heating (W1-W3), and the resulting value was taken as the mass of the solvent contained in the resin composition layer. The ratio of the mass of the solvent to the mass of the sample before heating was taken as the solvent content (solvent amount). The calculation formula for the solvent content (solvent amount) is as follows: Solvent amount (mass %) = {(W1-W3)-(W2-W3)} / (W2-W3) x 100 (1)

[0079]

[0080] The laminates of Examples 1 to 12 and Comparative Examples 1 to 5 obtained as described above were evaluated for the presence or absence of foreign matter after the substrate was peeled off, and for their appearance. The results are summarized in Table 4 below.

[0081] <Evaluation of the Presence or Absence of Foreign Matter When Peeling Off the Substrate> After storing the above laminate for 10 days in an environment of 25°C and 50% humidity, the substrate and resin composition layer were peeled off, and a 5 mm square of the surface of the peeled substrate was rubbed with tweezers to evaluate the presence or absence of foreign matter, with A to B being evaluated as passing (flaws at the time of peeling off the substrate were sufficiently suppressed). A: No visible foreign matter (powder) was generated. B: No visible foreign matter (powder) was generated on the substrate, but a small amount of foreign matter (powder) adhered to the tip of the tweezers. C: Visible foreign matter (powder) was generated on the substrate.

[0082] <Evaluation of Appearance of Laminate> The appearance of a 2 cm × 2 cm area of ​​the laminate (on the surface on the resin composition layer side) was visually observed under an illuminance of 1000 lx, and the number of white spots due to aggregation of inorganic particles, etc. was evaluated as follows: A: Less than 8 white spots with a diameter of 2 mm or more B: 8 to less than 15 white spots with a diameter of 2 mm or more C: 15 to less than 22 white spots with a diameter of 2 mm or more

[0083]

[0084] The results in Table 4 will be discussed below. The laminates of Examples 1 to 12, which satisfied the requirements of this embodiment, were able to sufficiently suppress damage when the substrate was peeled off. On the other hand, the laminates of Comparative Examples 1 to 5, which did not satisfy the requirements of this embodiment, were unable to sufficiently suppress damage when the substrate was peeled off.

Claims

1. A laminate comprising a substrate and a resin composition layer formed on the substrate, wherein the resin composition layer comprises inorganic particles, an epoxy resin, and a silane coupling agent and has a thickness of 0.10 mm or more and 1.00 mm or less, the ratio of the inorganic particles to the solid content of the resin composition layer is 50 mass % or more and 99 mass % or less, the inorganic particles have a particle diameter D50 of 10 μm or less at the cumulative 50% from the fine particle side of a cumulative particle size distribution on a volume basis, and the silane coupling agent has a polarization term dP of 2 or more and 10 or less.

2. The laminate according to claim 1, wherein the silane coupling agent is a compound represented by formula (1): X3-nMen-Si-Y (1) (wherein Me is a methyl group, X is a hydrolyzable group, Y is a monovalent organic group, and n is 0, 1, or 2).

3. The laminate according to claim 1 or 2, wherein the inorganic particles have 0.5 or more isolated OH groups per nm2.

4. The laminate according to claim 1 or 2, wherein the inorganic particles are alumina particles.

5. The laminate according to claim 1 or 2, further comprising a solvent.

6. The laminate according to claim 1 or 2, wherein the mass ratio of the content of the silane coupling agent to the content of the inorganic particles is 1:0.0001 to 1:0.05.

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