Resin composition and use of the same

Abstract

To provide a resin composition which is formed into a cured product that is excellent in low warpage property when a large area is sealed, and has a low dielectric loss tangent.SOLUTION: A resin composition contains (A) a bismaleimide compound, (B) a reaction initiator, and (C) silica powder, wherein when transmittance at a wave number of 4,000 cm-1 is 100% in a transmission spectrum by an FT-IR diffuse reflection method, (C) the silica powder has minimum transmittance at a wave number of 3,600 to 3,700 cm-1 of 68% or more, and minimum transmittance at a wave number of 3,200 to 3,500 cm-1 of 85% or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition having low dielectric properties and excellent resistance to warpage when used to encapsulate a large area, and to uses thereof. [Background technology]

[0002] In recent years, wafer level packages and panel level packages have been attracting attention as mobile devices such as smartphones become smaller, lighter, and more functional.

[0003] Warpage after encapsulation is a problem in wafer-level packaging and panel-level packaging. While molding and encapsulation can be performed without any problems on substrates such as small-diameter wafers, molding and encapsulation on large-diameter wafers exceeding 8 inches or on even larger-area panels causes significant warpage in the substrate. This is thought to be caused by differences in the thermal expansion coefficients of the substrate and the thermosetting resin. This warpage causes problems in subsequent processes such as transportation, grinding, inspection, and singulation, and may result in variations in element characteristics depending on the device.

[0004] In recent years, development of antenna-in-package (AiP) technology, which integrates an antenna and an RF-IC into a single package, has progressed. Because this technology is manufactured at the wafer level, it is required to minimize warpage after molding and encapsulation. Furthermore, antenna-in-package technology for fifth-generation mobile communication systems (5G) and advanced driver assistance systems (ADAS) uses millimeter-wave bands, making signal transmission loss a problem. This transmission loss is expressed as the sum of dielectric loss, conductor loss, and scattering loss. Dielectric loss is proportional to the square root of the dielectric constant (Dk) and the dielectric loss tangent (Df) of the dielectric. To effectively reduce dielectric loss, it is particularly important to reduce the dielectric loss tangent. Patent Documents 1 and 2 disclose epoxy resin compositions containing silicone resins to suppress warpage. However, to be suitable for use in millimeter-wave band packages, improvements are needed in terms of warpage and dielectric loss tangent. Patent Document 3 discloses a composition containing a solid bismaleimide compound having a hydrocarbon group derived from a dimer acid skeleton, and although the composition has a lower dielectric tangent than the above-mentioned epoxy resin composition, there is still room for further improvement. For these reasons, there is a demand for resin materials that minimize substrate warpage during encapsulation and have a lower dielectric loss tangent. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2021-116329 [Patent Document 2] Patent Publication No. 2021-116331 [Patent Document 3] Japanese Patent Application Publication No. 2019-203122 Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, an object of the present invention is to provide a resin composition that, even when applied to electronic parts that require low warpage, minimizes warpage and gives a cured product with a low dielectric loss tangent. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above problems and have found that the following resin composition can achieve the above object, thereby completing the present invention. That is, the present invention provides the following resin composition and a semiconductor device having a cured product of the composition.

[0008] <1> (A) a bismaleimide compound, (B) a reaction initiator, and (C) Silica powder A resin composition comprising: The silica powder (C) has a wave number of 4,000 cm in a transmittance spectrum measured by an FT-IR diffuse reflectance method. -1 When the transmittance of the -1 The minimum transmittance is 68% or more at a wave number of 3,200 to 3,500 cm -1 A resin composition comprising silica powder having a minimum transmittance of 85% or more at 1000 kJ / s. <2> Component (A) is a bismaleimide compound having one or more hydrocarbon groups derived from a dimer acid skeleton in one molecule. <1> The resin composition according to claim 1. <3> Component (A) is a bismaleimide compound represented by the following formula (1): <1> or <2> The resin composition according to claim 1. [ka] (In formula (1), A's are independently tetravalent organic groups having a cyclic structure; B's are independently divalent hydrocarbon groups other than hydrocarbon groups derived from a dimer acid skeleton having 6 to 60 carbon atoms; D's are independently divalent hydrocarbon groups having 6 to 200 carbon atoms, and at least one D is a hydrocarbon group derived from a dimer acid skeleton; m is 0 to 100; and n is 0 to 200. The order of the repeating units bracketed by m and n is not limited, and the bonding pattern may be alternating, block, or random.) <4> A in formula (1) is any of the tetravalent organic groups represented by the following structural formulas: <3> The resin composition according to claim 1. [ka] (The bond not bonded to a substituent in the above structural formula is bonded to the carbonyl carbon that forms the cyclic imide structure in formula (1).) <5> Component (C) is silica powder that has been heat-treated at 100 to 1,200°C. <1> ~ <4> The resin composition according to any one of the above. <6> The content of component (C) is 30 to 95% by mass of the total composition. <1> ~ <5> The resin composition according to any one of the above. <7> The component (B) is at least one selected from the group consisting of a thermal radical polymerization initiator and an anionic polymerization initiator. <1> ~ <6> The resin composition according to any one of the above. <8> The resin composition is in the form of granules, a sheet, or a film. <1> ~ <7> The resin composition according to any one of the above. <9> The resin composition is for use in wafer level packages, panel level packages, fan-out wafer level packages, fan-out panel level packages, and antenna-in-packages. <1> ~ <8> The resin composition according to any one of the above. <10> <1> ~ <9> A cured product of the resin composition according to any one of claims 1 to 11. <11> <10> A semiconductor device comprising a cured product of the resin composition described in claim 1. [Effects of the Invention]

[0009] The resin composition of the present invention can suppress warpage even when applied to electronic parts that require low warpage, and the cured product has a low dielectric loss tangent in the high frequency band. Therefore, by using the resin composition of the present invention, it is possible to provide a semiconductor device that is excellent in terms of processability and performance. DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in more detail below.

[0011] [(A) Bismaleimide compound] The resin composition of the present invention contains (A) a bismaleimide compound. A bismaleimide compound is a compound containing two maleimide groups per molecule. Unlike epoxy resins, bismaleimide compounds do not produce polar hydroxyl groups upon curing, resulting in a low dielectric dissipation factor. Among these, bismaleimide compounds containing one or more hydrocarbon groups derived from a dimer acid skeleton per molecule are preferred due to their low dielectric dissipation factor. Dimer acid is a liquid fatty acid consisting of a dicarboxylic acid with 36 carbon atoms, obtained by dimerizing an unsaturated fatty acid with 18 carbon atoms derived from vegetable oils such as oleic acid and linoleic acid. Dimer acids do not have a single skeleton but have multiple structures, resulting in the existence of several isomers. Representative dimer acids are classified as follows: linear (a), monocyclic (b, c), aromatic (d), and polycyclic (e), as shown below. [ka] In this specification, the term "dimer acid skeleton" refers to a group derived from a dimer diamine having a structure in which the carboxy groups of such a dimer acid are substituted with primary aminomethyl groups. That is, component (A) preferably has a dimer acid skeleton in which the two carboxy groups in each of the dimer acids (a) to (e) above are substituted with methylene groups. Furthermore, from the viewpoint of the heat resistance and reliability of the cured product, it is more preferable that the divalent hydrocarbon group derived from the dimer acid skeleton of component (A) has a structure in which the carbon-carbon double bond in the hydrocarbon group derived from the dimer acid skeleton is reduced by a hydrogenation reaction. Generally, dimer acids may contain trimers (trimer acids) due to the use of natural products such as vegetable oils and fats as raw materials. However, those with a high proportion of dimer acid-derived hydrocarbon groups, for example, 95 mass % or more of the hydrocarbon groups derived from dimer acids and trimer acids, are preferred because they have excellent dielectric properties, are easily reduced in viscosity when heated, are excellent in formability, and tend to be less affected by moisture absorption.

[0012] The component (A) contained in the resin composition of the present invention is preferably a maleimide compound represented by the following formula (1). [ka] (In formula (1), A's are independently tetravalent organic groups having a cyclic structure; B's are independently divalent hydrocarbon groups other than hydrocarbon groups derived from a dimer acid skeleton having 6 to 60 carbon atoms; D's are independently divalent hydrocarbon groups having 6 to 200 carbon atoms, and at least one D is a hydrocarbon group derived from a dimer acid skeleton; m is 0 to 100; and n is 0 to 200. The order of the repeating units bracketed by m and n is not limited, and the bonding pattern may be alternating, block, or random.)

[0013] A composition containing the bismaleimide compound represented by formula (1) has superior dielectric properties to compositions containing other common aromatic bismaleimide compounds, and also has a low elastic modulus after curing, which reduces warpage of the substrate after encapsulation and improves crack resistance in reliability tests.

[0014] In the formula (1), A independently represents a tetravalent organic group having a cyclic structure, and is preferably any of the tetravalent organic groups represented by the following structural formulas. [ka] (The bond not bonded to a substituent in the above structural formula is bonded to the carbonyl carbon that forms the cyclic imide structure in formula (1).)

[0015] In the formula (1), D's are independently divalent hydrocarbon groups having 6 to 200 carbon atoms, preferably 8 to 100 carbon atoms, and more preferably 10 to 50 carbon atoms. Among these, branched divalent hydrocarbon groups in which one or more hydrogen atoms in the divalent hydrocarbon group are substituted with alkyl or alkenyl groups having 6 to 200 carbon atoms, preferably 8 to 100 carbon atoms, and more preferably 10 to 50 carbon atoms, are preferred. The branched divalent hydrocarbon group may be either a saturated aliphatic hydrocarbon group or an unsaturated hydrocarbon group, and may have an alicyclic structure or an aromatic ring structure in the middle of the molecular chain. Specific examples of the branched divalent hydrocarbon group include divalent hydrocarbon groups derived from diamines at both ends, called dimer diamines. Therefore, D is particularly preferably a group in which the two carboxy groups in each of the dimer acids (a) to (e) above are each substituted with a methylene group, and at least one of D in one molecule is a hydrocarbon group derived from the dimer acid skeleton.

[0016] In the formula (1), each B is independently a divalent hydrocarbon group other than a hydrocarbon group derived from a dimer acid skeleton having 6 to 60 carbon atoms, preferably a divalent aliphatic hydrocarbon group, more preferably a divalent aliphatic hydrocarbon group having 6 to 30 carbon atoms. The aliphatic hydrocarbon group is preferably one having a cyclohexane skeleton, and the group having a cyclohexane skeleton may be, for example, one having one cyclohexane ring, as represented by the following formula (2), or may be a polycyclic group having a plurality of cyclohexane rings bonded via an alkylene group or a bridged structure. [ka] (In formula (2), R 1 are independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and x1 and x2 are each independently a number from 0 to 4.

[0017] where R 1 Specific examples of R include a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a t-butyl group. Among these, a hydrogen atom and a methyl group are preferred. 1may be the same or different. Furthermore, the x1 and x2 each independently represent a number from 0 to 4, and preferably a number from 0 to 2. Note that x1 and x2 may be the same or different.

[0018] Specific examples of B include divalent alicyclic hydrocarbon groups represented by the following structural formulas. [ka] (The bond not bonded to a substituent in the above structural formula is bonded to the nitrogen atom that forms the cyclic imide structure in formula (1).)

[0019] In the formula (1), m is 0 to 100, preferably 1 to 60, and more preferably 1 to 50, and n is 0 to 200, preferably 0 to 50, and more preferably 0 to 40. If m or n is too large, the flowability may decrease, and moldability may be poor. The order of the repeating units bracketed by m and n is not limited, and the bonding pattern may be alternating, block, or random, but a block bond is preferred from the viewpoint of facilitating a high Tg.

[0020] The bismaleimide compound of component (A) is preferably a solid at 25°C, as this provides ease of handling and minimizes warpage after molding.

[0021] The number average molecular weight of the bismaleimide compound of component (A) is not particularly limited, but from the viewpoint of the handleability of the composition, it is preferably 800 to 50,000, and more preferably 900 to 30,000. Furthermore, component (A) may be used singly or in combination of two or more types. The number average molecular weight referred to in the present invention refers to the number average molecular weight measured by gel permeation chromatography (GPC) under the following conditions using polystyrene as a standard substance.

[0022] [Measurement conditions] Developing solvent: tetrahydrofuran (THF) Flow rate: 0.35mL / min Detector: Refractive index detector (RI) Column: TSK Guardcolumn SuperH-L TSKgel SuperHZ4000(4.6mmI.D.×15cm×1) TSKgel SuperHZ3000(4.6mmI.D.×15cm×1) TSKgel SuperHZ2000 (4.6mmI.D.×15cm×2) (All manufactured by Tosoh) Column temperature: 40℃ Sample injection volume: 5 μL (0.2% by mass THF solution)

[0023] In the composition of the present invention, the content of component (A) is preferably 5 to 60 mass %, more preferably 8 to 50 mass %, and even more preferably 10 to 40 mass %, with the total mass of the composition being 100 mass %.

[0024] [(B) Reaction initiator] The reaction initiator used in the present invention is added to promote the reaction of component (A) with another component having a maleimide group or a functional group reactive with component (A). Component (B) is not particularly limited as long as it promotes the curing reaction, but thermal radical polymerization initiators and / or anionic polymerization initiators are preferred because they exhibit good curability.

[0025] The thermal radical polymerization initiator is preferably an organic peroxide such as a hydroperoxide, a dialkyl peroxide, a peroxyester, a diacyl peroxide, a peroxycarbonate, a peroxyketal, or a ketone peroxide. From the viewpoint of storage stability, an organic peroxide having a 10-hour half-life temperature of 70 to 170°C is more preferred. Specific examples of the thermal radical polymerization initiator include dicumyl peroxide, t-butyl peroxybenzoate, t-amyl peroxybenzoate, dibenzoyl peroxide, diuraloyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylcumyl peroxide, di-tert-butyl peroxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, and 1,1-di(t-butylperoxy)cyclohexane.

[0026] The anionic polymerization initiator is preferably at least one compound selected from the group consisting of imidazole compounds, phosphorus compounds, amine compounds and urea compounds. Specific examples of the imidazole compound include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, and 1-cyanoethyl-2-ethyl-4-methylimidazole. Examples of the imidazoles include imidazoles having a diaminotriazine ring such as 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, and microencapsulated versions of these. Specific examples of phosphorus compounds include tributylphosphine, tri(p-methylphenyl)phosphine, tri(nonylphenyl)phosphine, triphenylphosphine, triphenylphosphine-triphenylborane, tetraphenylphosphine-tetraphenylborate, and microencapsulated versions of these compounds. Specific examples of the amine compound include triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, 1,8-diazabicyclo[5.4.0]undecene, tris(dimethylaminomethyl)phenol, and microencapsulated versions of these compounds. Specific examples of the urea compound include N,N,N',N'-tetramethylurea, N'-phenyl-N,N-dimethylurea, N,N-diethylurea, N'-[3-[[[(dimethylamino)carbonyl]amino]methyl]-3,5,5-trimethylcyclohexyl]-N,N-dimethylurea, and N,N"-(4-methyl-1,3-phenylene)bis(N',N'-dimethylurea).

[0027] These reaction initiators may be used alone or in combination of two or more, regardless of type. The amount of the reaction initiator is preferably 0.1 to 8 parts by mass, more preferably 0.2 to 6 parts by mass, and even more preferably 0.3 to 4 parts by mass, per 100 parts by mass of the total of component (A). If the amount of the reaction initiator is 0.1 part by mass or more, the curing reaction will proceed sufficiently, and if it is 8 parts by mass or less, the storage stability of the resin composition will be good.

[0028] [(C) Silica powder] The component (C) used in the present invention has a transmittance spectrum measured by the FT-IR diffuse reflectance method at a wave number of 4,000 cm -1 When the transmittance of the -1 The minimum transmittance is 68% or more at a wave number of 3,200 to 3,500 cm -1 It is characterized by a minimum transmittance of 85% or more. Wave number 3,600~3,700cm -1The peak at wavenumbers of 3,600 to 3,700 cm is due to hydrogen-bonded silanol groups (Si-OH) present in silica powder. -1 The higher the transmittance in this range, the fewer hydrogen-bonding silanol groups there are in component (C). Because silanol groups are polar groups, the greater the amount of hydrogen-bonding silanol groups in component (C), the higher the dielectric loss tangent. -1 ) has a minimum transmittance of 68% or more, which means that there are fewer hydrogen-bonding silanol groups in the silica powder, which reduces the dielectric tangent of the silica powder itself, making it possible to lower the dielectric tangent of the resin composition. Also, wave numbers of 3,200 to 3,500 cm -1 The peaks occurring at wavenumbers of 3,200 to 3,500 cm are due to water adsorbed on the silica powder. -1 The higher the transmittance in this range, the less water is adsorbed to the silica powder. Because water has polarity, the more water is adsorbed to component (C), the higher the dielectric loss tangent. -1 ) has a minimum transmittance of 85% or more, which means that the silica powder absorbs less water and the dielectric tangent of the silica powder itself is lowered, making it possible to lower the dielectric tangent of the resin composition.

[0029] The method for measuring the transmittance spectrum of component (C) by FT-IR diffuse reflectance is not particularly limited, but the following method can be used, for example: KBr is ground in a mortar and filled to the brim in a 1.5 mm thick aluminum pan. This sample is placed in a Fourier transform infrared spectrophotometer (IR Affinity-1S) equipped with a diffuse reflectance measuring device (DRS-8000A), and a blank measurement is performed at wavenumbers of 400 to 4,000 cm. -1 Next, the silica powder is filled up to the level in a 1.5 mm thick aluminum pan, and the transmittance is measured in the same manner for wave numbers of 400 to 4,000 cm. -1 The transmittance is measured.

[0030] Wavenumbers of 3,600 to 3,700 cm in the transmittance spectrum of component (C) -1Minimum transmittance and wavenumber between 3,200 and 3,500 cm -1 The minimum transmittance at is calculated using the following procedure. Procedure: The transmittance values ​​for each wavenumber obtained by the above measurement method are calculated at a wavenumber of 4,000 cm -1 By subtracting the transmittance value of 4,000 cm and adding 100, the transmittance at each wavenumber is calculated. -1 The value is converted to a value when the transmittance of the wavelength is 100%. -1 and wavenumber 3,200-3,500 cm -1 The smallest transmittance in the range is defined as the minimum transmittance in the range.

[0031] (C) FT-IR diffuse reflectance transmittance spectrum of component (C) at a wavenumber of 4,000 cm -1 When the transmittance of the -1 The minimum transmittance at is 68% or more, preferably 69% or more, and more preferably 70% or more.

[0032] (C) FT-IR diffuse reflectance transmittance spectrum of component (C) at a wavenumber of 4,000 cm -1 When the transmittance of the -1 The minimum transmittance at is 85% or more, preferably 86% or more, and more preferably 87% or more.

[0033] As component (C), a transmittance spectrum measured by the FT-IR diffuse reflectance method using the method described above has a wave number of 4,000 cm -1 When the transmittance of the -1 The minimum transmittance is 68% or more at a wave number of 3,200 to 3,500 cm -1 Commercially available silica powders may be used as long as they have a minimum transmittance of 85% or more at 100°C. However, it is preferable to use silica powders that have been heat-treated, and it is more preferable to use silica powders that have been heat-treated at 100 to 1,200°C. That is, component (C) used in the present invention can be suitably obtained by heat-treating silica powder. It is believed that heat-treating silica powder condenses hydrogen-bonding silanol groups (Si-OH) to form Si-O-Si bonds. Furthermore, heat-treating silica powder removes water that has hydrogen-bonded to the silanol groups. However, the higher the heating temperature, the more strain is generated on the silica powder surface, reducing the reinforcing effect of the silica powder. Therefore, the heating temperature of the silica powder in the present invention is preferably 100 to 1,200°C, more preferably 500 to 1,200°C, and even more preferably 800 to 1,200°C. Heating temperatures below 100°C are insufficient to promote the condensation reaction, while heating temperatures above 1,200°C tend to cause fusion of silica particles. Within the above temperature range, the heating temperature may be constant or may be varied over time. The heating time of the silica powder is preferably 1 to 10 hours, more preferably 2 to 8 hours, and even more preferably 3 to 6 hours.

[0034] The atmosphere in which the silica powder is heated is not particularly limited, and it may be air, nitrogen, vacuum, etc. The heating furnace used for heating is not particularly limited as long as it can heat to 100 to 1,200°C, and examples of the heating furnace include a gas furnace, an electric furnace, a muffle furnace, a vacuum furnace, and a laser heating furnace.

[0035] The maximum particle size of component (C) is not particularly limited, but is preferably 55 μm or less, more preferably 40 μm or less, and even more preferably 20 μm or less. The maximum particle size refers to the maximum value in the volume particle size distribution measured by a laser diffraction scattering measurement method.

[0036] The average particle size D50 of component (C) is preferably 0.1 to 30 μm, more preferably 0.1 to 20 μm, and even more preferably 0.1 to 10 μm, as measured by a volume particle size distribution using a laser diffraction scattering method.

[0037] Component (C) may be top-cut if necessary. Here, "top-cut" refers to classifying the produced silica particles by a wet sieve method. The opening of the sieve used for classification is called the top-cut diameter, and the top-cut diameter refers to a value at which the proportion of particles larger than the opening is 2% by volume or less in the volume particle size distribution measured by a laser diffraction scattering measurement method. The top-cut diameter in the wet sieve method is preferably 1 to 55 μm, more preferably 1 to 40 μm, and even more preferably 1 to 20 μm.

[0038] In order to strengthen the bond strength with the resin component, component (C) may be surface-treated in advance with a silane coupling agent. Examples of silane coupling agents include epoxy silanes such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino silanes such as N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-8-aminooctyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, and 2,2-dimethoxy-1-phenyl-1-aza-2-silacyclopentane; and 3-mercapto Examples of suitable silane coupling agents include epoxy, amino, mercapto, vinyl, styryl, or methacryl groups, such as silane, mercaptosilanes such as 3-episulfidoxypropyltrimethoxysilane, vinylsilanes such as vinyltrimethoxysilane and vinyltriethoxysilane, styrylsilanes such as p-styryltrimethoxysilane, and methacrylsilanes such as 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropyltriethoxysilane. From the viewpoint of improving strength, silane coupling agents having an amino group, a methacryl group, a vinyl group, or a styryl group are preferred, and silane coupling agents having an amino group are particularly preferred. These silane coupling agents may be used alone or in combination of two or more. The treatment method with a silane coupling agent is not particularly limited and may be a conventionally known method. The amount of the silane coupling agent used for surface treatment may be adjusted appropriately depending on the desired properties, as long as the treated silica powder satisfies the above transmittance. For example, the amount of the silane coupling agent is preferably 0.1 to 5 parts by mass, more preferably 0.15 to 4 parts by mass, and even more preferably 0.2 to 3 parts by mass, per 100 parts by mass of component (C).

[0039] The blend amount of component (C) is preferably 50 to 2,000 parts by mass, more preferably 70 to 1,200 parts by mass, and even more preferably 100 to 1,000 parts by mass per 100 parts by mass of component (A). Furthermore, the blend amount of component (C) in the composition is preferably 30 to 95% by mass, more preferably 40 to 92% by mass, and even more preferably 50 to 90% by mass, based on 100% by mass of the entire composition. If the blend amount of component (C) is within this range, the viscosity during molding will not become too high, and molding defects can be prevented.

[0040] <Other additives> The resin composition of the present invention may further contain various additives as needed, provided that the effects of the present invention are not impaired. Examples of other additives are listed below.

[0041] [Inorganic fillers other than component (C)] In the present invention, an inorganic filler other than component (C) may be added. Examples of inorganic fillers include alumina, silicon nitride, aluminum nitride, boron nitride, titanium oxide, glass fiber, and magnesium oxide. Furthermore, fluororesin-containing fillers or fluororesin-coated fillers may be used to improve dielectric properties. These inorganic fillers may be used alone or in combination of two or more. From the viewpoint of dielectric properties, the content of inorganic fillers other than component (C) is preferably 0 to 50% by mass, more preferably 0 to 45% by mass, and even more preferably 0 to 40% by mass, with the total including component (C) being 100% by mass. The average particle size and shape of these inorganic fillers can be selected depending on the application.

[0042] [Thermosetting resin having a reactive group capable of reacting with a maleimide group] In the present invention, a thermosetting resin having a reactive group capable of reacting with a maleimide group may also be added. The thermosetting resin is not limited to any particular type, and examples include various resins other than component (A), such as epoxy resins, phenolic resins, cyanate resins, melamine resins, silicone resins, cyclic imide resins including maleimide compounds other than component (A), urea resins, thermosetting polyimide resins, modified polyphenylene ether resins, thermosetting acrylic resins, and epoxy-silicone hybrid resins. Examples of reactive groups that can react with maleimide groups include epoxy groups, maleimide groups, hydroxyl groups, acid anhydride groups, alkenyl groups such as allyl groups and vinyl groups, (meth)acrylic groups, and thiol groups. However, examples of groups that can react with maleimide groups, such as epoxy groups, to form active species that react with maleimide groups to undergo anionic polymerization. The amount of the thermosetting resin having a reactive group that can react with maleimide groups is not particularly limited, but is preferably 0 to 60 mass %, more preferably 0 to 50 mass %, and even more preferably 0 to 40 mass % of the total thermosetting resin. These thermosetting resins may be used alone or in combination of two or more.

[0043] [Flame retardant] In the present invention, a flame retardant may be added to impart flame retardancy. Examples of the flame retardant include halogenated epoxy resins, phosphazene compounds, silicone compounds, zinc molybdate-supported talc, zinc molybdate-supported zinc oxide, aluminum hydroxide, magnesium hydroxide, molybdenum oxide, and antimony trioxide. These flame retardants may be used alone or in combination of two or more. However, from the viewpoint of environmental load and ensuring fluidity, phosphazene compounds, zinc molybdate-supported zinc oxide, molybdenum oxide, aluminum hydroxide, and magnesium hydroxide are preferably used.

[0044] [Ion trapping agents] In the present invention, an ion trapping agent may be added to improve electrical properties. Examples of the ion trapping agent include hydrotalcite compounds, bismuth compounds, and zirconium compounds, and these may be used alone or in combination of two or more.

[0045] [Flexibility imparting agent] In the present invention, a flexibility-imparting agent may be added to impart flexibility. Examples of the flexibility-imparting agent include silicone compounds such as silicone oil, silicone resin, silicone-modified epoxy resin, and silicone-modified phenolic resin, and thermoplastic elastomers such as styrene resin and acrylic resin. These may be used alone or in combination of two or more.

[0046] [Coloring agent] In the present invention, a colorant may be added to stabilize the color of the appearance after sealing. Examples of colorants include carbon black, titanium black, titanium oxide, etc., and these may be used alone or in combination of two or more. Titanium black is preferred because it can suppress an increase in the dielectric loss tangent.

[0047] In addition to the above, an adhesive aid, a release agent, a reactive diluent, a light stabilizer, etc. may be added.

[0048] The relative dielectric constant at 10 GHz of the cured product of the resin composition of the present invention is preferably 3.5 or less, more preferably 3.3 or less, and even more preferably 3.2 or less.

[0049] The dielectric loss tangent at 10 GHz of the cured product of the resin composition of the present invention is preferably 0.002 or less, more preferably 0.0018 or less, and even more preferably 0.0015 or less, from the viewpoint of reducing transmission loss.

[0050] The molding method and measurement method for the cured product are not particularly limited, but an example is a method in which the resin composition of the present invention is thermally cured using a vacuum press (manufactured by Nikko Materials) to obtain a cured resin film of 5 cm x 5 cm x 200 μmt, and then the relative permittivity (Dk) and dielectric loss tangent (Df) at a frequency of 10 GHz of the post-cured cured resin film are measured using an apparatus connected to a network analyzer (manufactured by Keysight) and a strip line (manufactured by Keycom).

[0051] Conventional known methods can be used as appropriate for producing the resin composition of the present invention. Examples of equipment used in producing the resin composition of the present invention include planetary mixers, heated rolls, kneaders, and extruders. Using these equipment, predetermined amounts of each component are melt-mixed at 60°C or higher and then cooled to 30°C or lower to obtain a resin composition. If the resulting resin composition is solid, it may be pulverized into a powder, pulverized and then compressed into tablets, pulverized and then sieved to remove coarse particles and fine powder, or formed into a sheet using a press or T-die. Alternatively, the resin composition (varnish) dissolved in an organic solvent may be applied to a support sheet and then heated at a temperature typically above 80°C, preferably above 100°C, for 1 to 60 minutes to remove the organic solvent and form an uncured film. To facilitate handling during use and minimize the impact of dust contamination, the resin composition is preferably in the form of granules, sheets, or films.

[0052] <Applications of resin composition> The resin composition of the present invention is not particularly limited in its applications, but because it exhibits minimal warpage when encapsulating a large area, it is effective as a resin composition for wafer-level packages, panel-level packages, fan-out wafer-level packages, and fan-out panel-level packages. Furthermore, because the resin composition of the present invention has excellent dielectric properties at high frequencies (low relative dielectric constant and low dielectric dissipation factor), it is also suitable for antenna-in-package applications. The method for encapsulating a semiconductor device with the resin composition of the present invention is not particularly limited, and conventional molding methods such as transfer molding, injection molding, compression molding, casting, and lamination may be used, with compression molding and lamination being more preferred. The molding conditions for the resin composition of the present invention are preferably 120 to 180°C for 120 to 800 seconds. If necessary, the resulting molded product may be post-cured. The post-curing is preferably performed at 150 to 250°C for 0.5 to 5 hours. [Example]

[0053] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. The components used in the examples and comparative examples are listed below. The wave number of the silica powder is 3,600 to 3,700 cm. -1 Minimum transmittance and wavenumber 3,200-3,500 cm -1 The minimum transmittance at is the value calculated by the above method.

[0054] (A) Bismaleimide compound (A-1): A hydrocarbon group-containing bismaleimide compound derived from a dimer acid skeleton represented by the following formula (trade name: SLK-3000, manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight: 8,000) [ka] -C 36 H 70 - indicates a structure derived from a dimer acid skeleton. m≒5 (average value) (A-2): A hydrocarbon group-containing bismaleimide compound derived from a dimer acid skeleton represented by the following formula (trade name: SLK-2600, manufactured by Shin-Etsu Chemical Co., Ltd., number average molecular weight: 5000) [ka] -C 36 H 70 - indicates a structure derived from a dimer acid skeleton. m≒2, n≒2 (average value)

[0055] (B) Reaction initiator (B-1): Dicumyl peroxide (trade name: Percumyl D, manufactured by NOF Corporation) (B-2): 2-ethyl-4-methylimidazole (trade name: 2E4MZ, manufactured by Shikoku Chemicals Corporation)

[0056] (C) Silica powder (C-1): Fused spherical silica (product name: MUF-4, manufactured by Tatsumori Co., Ltd.) with an average particle size of 4 μm and a top cut diameter of 20 μm was heat-treated in an electric furnace at 800 °C for 4 hours (wave number 3,600 to 3,700 cm -1 Minimum transmittance at 3,200-3,500 cm: 68% -1 Minimum transmittance at: 85%) (C-2): Fused spherical silica (product name: MUF-4, manufactured by Tatsumori Co., Ltd.) with an average particle size of 4 μm and a top cut diameter of 20 μm was heat-treated in an electric furnace at 1,000 °C for 5 hours (wave number 3,600 to 3,700 cm -1 Minimum transmittance at 73% for wavenumbers of 3,200-3,500 cm -1 Minimum transmittance at: 95%) (C-3): Fused spherical silica (product name: FB-5604FC, manufactured by Denka Co., Ltd.) with an average particle size of 27 μm and a maximum particle size of 55 μm was heat-treated in an electric furnace at 1,000 °C for 5 hours (wave number 3,600 to 3,700 cm -1 Minimum transmittance at 3,200-3,500 cm: 72% -1 Minimum transmittance at: 95%) (C-4): Silica powder (wave number 3,600 to 3,700 cm) that has been dry surface-treated with 0.3 parts by mass of N-phenyl-3-aminopropyltrimethoxysilane (trade name: KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.) per 100 parts by mass of (C-2). -1 Minimum transmittance at 3000-3500 cm: 74% -1 Minimum transmittance at: 95%) (C'-5): Fused spherical silica (product name: MUF-4, manufactured by Tatsumori Co., Ltd.) with an average particle size of 4 μm and a top cut diameter of 20 μm (wave number 3,600 to 3,700 cm -1 Minimum transmittance at 60% for wavenumbers of 3,200-3,500 cm -1 Minimum transmittance at: 79%) (C'-6): Fused spherical silica (trade name: FB-5604FC, manufactured by Denka Co., Ltd.) with an average particle size of 27 μm and a maximum particle size of 55 μm (wave number 3,600 to 3,700 cm -1 Minimum transmittance at 63% for wavenumbers of 3,200-3,500 cm -1 Minimum transmittance at: 78%) (C'-7): 100 parts by mass of fused spherical silica (trade name: MUF-4, manufactured by Tatsumori Co., Ltd.) having an average particle size of 4 μm and a top cut diameter of 20 μm, and 0.3 parts by mass of N-phenyl-3-aminopropyltrimethoxysilane (trade name: KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.) dry surface-treated silica powder (wave number 3,600 to 3,700 cm -1 Minimum transmittance at 3,200-3,500 cm: 62% -1 Minimum transmittance at: 83%)

[0057] (D) Other thermosetting resins (D-1): Dicyclopentadiene-type epoxy resin (product name: HP-7200, manufactured by DIC Corporation) (D-2): Novolac phenolic resin (product name: TD-2131, manufactured by DIC Corporation)

[0058] [Examples 1 to 9, Comparative Examples 1 to 4] The components were melt-mixed at 80°C in the proportions (parts by mass) shown in Table 1, cooled to 30°C, and pulverized, followed by removal of coarse particles and fine powder using sieves with 2mm and 0.5mm openings to obtain granular resin compositions. Each composition was evaluated according to the methods described below, and the results are shown in Table 1.

[0059] <Warping> The above resin composition was molded onto a 12-inch / 775 μm thick silicon wafer using a compression molding machine (manufactured by Apic Yamada) so that the resin thickness after molding would be 400 μm. The molding temperature and molding time were as shown in Table 1. After post-curing at 180°C for 2 hours, the warpage of the wafer was measured using a shadow moire warpage measuring device (manufactured by Akrometrix).

[0060] <Dielectric properties> The resin composition was thermally cured using a vacuum press (manufactured by Nikko Materials) at the molding temperature and for the molding time listed in Table 1 to obtain a cured resin film measuring 5 cm × 5 cm × 200 μm. The cured resin film was post-cured at 180°C for 2 hours, and then the relative permittivity (Dk) and dielectric loss tangent (Df) at a frequency of 10 GHz were measured using a network analyzer (manufactured by Keysight) connected to a stripline (manufactured by Keycom).

[0061] [Table 1]

[0062] As shown in Table 1, the cured product of the resin composition of the present invention exhibits minimal warpage after molding and has a low dielectric loss tangent. Therefore, by using the resin composition of the present invention, it is possible to provide a semiconductor device that is excellent in terms of processability and performance.

Claims

1. (A) a bismaleimide compound, (B) a reaction initiator, and (C) Silica powder A resin composition comprising: The silica powder (C) has a transmittance spectrum of 4,000 cm in a wave number measured by an FT-IR diffuse reflectance method. -1 When the transmittance is 100%, the wave number is 3,600 to 3,700 cm -1 The minimum transmittance is 68% or more at a wave number of 3,200 to 3,500 cm -1 The resin composition is a silica powder having a minimum transmittance of 85% or more at 1000 Hz.

2. 2. The resin composition according to claim 1, wherein component (A) is a bismaleimide compound having one or more hydrocarbon groups derived from a dimer acid skeleton in each molecule.

3. 2. The resin composition according to claim 1, wherein the component (A) is a bismaleimide compound represented by the following formula (1): 【Chemical 1】 (In formula (1), A's are independently tetravalent organic groups having a cyclic structure; B's are independently divalent hydrocarbon groups other than hydrocarbon groups derived from a dimer acid skeleton having 6 to 60 carbon atoms; D's are independently divalent hydrocarbon groups having 6 to 200 carbon atoms, and at least one D is a hydrocarbon group derived from a dimer acid skeleton; m is 0 to 100; and n is 0 to 200. The order of the repeating units bracketed by m and n is not limited, and the bonding pattern may be alternating, block, or random.)

4. 4. The resin composition according to claim 3, wherein A in formula (1) is any one of tetravalent organic groups represented by the following structural formulas: 【Chemistry 2】 (The bond not bonded to a substituent in the above structural formula is bonded to the carbonyl carbon that forms the cyclic imide structure in formula (1).)

5. 2. The resin composition according to claim 1, wherein component (C) is a silica powder that has been heat-treated at 100 to 1,200°C.

6. 2. The resin composition according to claim 1, wherein the content of component (C) is 30 to 95% by mass of the entire composition.

7. 2. The resin composition according to claim 1, wherein the component (B) is at least one selected from the group consisting of a thermal radical polymerization initiator and an anionic polymerization initiator.

8. 2. The resin composition according to claim 1, which is in the form of granules, a sheet or a film.

9. The resin composition according to claim 1, which is used for a wafer level package, a panel level package, a fan-out wafer level package, a fan-out panel level package, or an antenna-in-package.

10. A cured product of the resin composition according to claim 1.

11. A semiconductor device comprising a cured product of the resin composition according to claim 10.

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