Resin composition for sealing the semiconductor element mounting surface of a substrate on which a semiconductor element is mounted or the semiconductor element forming surface of a wafer on which a semiconductor element is formed, and use thereof

Abstract

To provide an encapsulation resin composition favorable for application of encapsulating a semiconductor element-mounted face of a circuit board mounted with a semiconductor element, or a semiconductor element-formed face of a wafer formed with a semiconductor element, and excellent in low warpage property and grindability.SOLUTION: A resin composition for encapsulating a semiconductor element-mounted face of a circuit board mounted with a semiconductor element, or a semiconductor element-formed face of a wafer formed with a semiconductor element includes: (A) a maleimide compound having one or more hydrocarbon group(s) derived from a dimer acid skeleton in one molecule; (B) a reaction initiator; and (C) an inorganic filler subjected to surface treatment with a silane coupling agent, where the maximum particle size of the constituent (C) is 40 μm or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition for sealing a semiconductor element mounting surface of a substrate on which a semiconductor element is mounted or a semiconductor element forming surface of a wafer on which a semiconductor element is formed, and to use of the same. [Background technology]

[0002] In recent years, wafer-level packaging (WLP) and panel-level packaging (PLP) have been gaining attention as mobile devices such as smartphones become smaller, lighter, and more functional. In WLP, the semiconductor-mounting surface of an 8-inch or 12-inch substrate carrying semiconductor elements or the semiconductor-forming surface of a wafer carrying semiconductor elements is encapsulated with a thermosetting resin. After grinding, rewiring, and solder ball mounting, the wafer is singulated to complete the package. In addition to achieving smaller and lighter packages, high-density packaging is also possible by using TSV (Through Silicon Via) and CoC (Chip on Chip) technologies to connect semiconductor elements in multiple layers and mount them on a substrate such as a silicon interposer. Unlike conventional methods, where wafers are processed, cut into individual chips, and then packaged, this method also reduces manufacturing costs by packaging the wafer and then cutting into individual chips to complete the product.

[0003] Warpage after encapsulation is a problem in wafer-level packaging and panel-level packaging. Small-diameter wafers and other substrates can be molded and encapsulated without major issues, but with 8-inch or larger (12-inch) wafers and even larger panel-level molding, the difference in thermal expansion coefficients between the substrate and the thermosetting resin causes significant warpage in the substrate. 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] To solve these problems, Patent Document 1 discloses a composition containing a liquid bismaleimide compound having a divalent hydrocarbon group derived from a dimer acid skeleton, but it was found that the allyl compound added as a reactive diluent increases the elastic modulus after curing, resulting in significant warpage in large wafers of 12 inches or larger. Patent Document 2 also discloses a composition containing a solid bismaleimide compound having a hydrocarbon group derived from a dimer acid skeleton, but it was found that there is room for further improvement in terms of surface roughness after grinding. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-1289 [Patent Document 2] 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 an encapsulating resin composition that minimizes warpage even when applied to electronic components that require low warpage, and that produces a cured product with low surface roughness after grinding. [Means for solving the problem]

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

[0008] <1> A resin composition for sealing a semiconductor element mounting surface of a substrate on which a semiconductor element is mounted or a semiconductor element forming surface of a wafer on which a semiconductor element is formed, (A) A maleimide compound having one or more hydrocarbon groups derived from a dimer acid skeleton in one molecule. (B) Reaction initiator and (C) Inorganic filler surface-treated with a silane coupling agent wherein the maximum particle size of the component (C) is 40 μm or less. <2> The component (A) is a maleimide compound represented by at least the following formula (1) and / or (2): <1> The encapsulating 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 alicyclic hydrocarbon groups having 6 to 60 carbon atoms; D's are independently divalent hydrocarbon groups having 6 to 200 carbon atoms, at least one of which is a hydrocarbon group derived from a dimer acid skeleton; m is 1 to 100; and l is 1 to 200. The order of the repeating units bracketed by m and l is not limited, and the bonding pattern may be alternating, block, or random.) [ka] (In formula (2), A's are independently tetravalent organic groups having a cyclic structure, D's are independently divalent hydrocarbon groups having 6 to 60 carbon atoms, and at least one D is a hydrocarbon group derived from a dimer acid skeleton. n is 0 to 100.) <3> A in formula (1) and formula (2) is any of the tetravalent organic groups represented by the following structural formulas: <2> The encapsulating resin composition according to claim 1. [ka] <4> The silane coupling agent used for surface treatment of the inorganic filler of component (C) is one or more aminosilanes selected from 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. <1> ~ <3> The encapsulating resin composition according to any one of the preceding claims. <5> The content of component (C) is 30 to 95% by mass of the total composition. <1> ~ <4> The encapsulating resin composition according to any one of the preceding items. <6> The component (B) is a thermal radical polymerization initiator and / or an anionic polymerization initiator. <1> ~ <5> The encapsulating resin composition according to any one of the preceding items. <7> The encapsulating resin composition is in the form of granules, a sheet, or a film. <1> ~ <6> The encapsulating resin composition according to any one of the preceding items. <8> The encapsulating 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> ~ <7> The encapsulating resin composition according to any one of the preceding items. <9> <1> ~ <8> A semiconductor device comprising a cured product of the encapsulating resin composition according to any one of the preceding items. [Effects of the Invention]

[0009] The encapsulating resin composition of the present invention can suppress warpage to a minimum even when applied to electronic parts that require low warpage, and can provide a cured product with low surface roughness after grinding. Therefore, the encapsulating resin composition of the present invention is useful for encapsulating the semiconductor element mounting surface of a substrate on which a semiconductor element is mounted or the semiconductor element forming surface of a wafer on which a semiconductor element is formed. DETAILED DESCRIPTION OF THE INVENTION

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

[0011] [(A) Maleimide compound having one or more hydrocarbon groups derived from a dimer acid skeleton per molecule] The encapsulating resin composition of the present invention contains (A) a maleimide compound having one or more hydrocarbon groups derived from a dimer acid skeleton per molecule. Dimer acid is a liquid fatty acid 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, and several types of isomers exist. Representative dimer acids are classified as linear (a), monocyclic (b, c), aromatic (d), and polycyclic (e). 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 shown below in (a) to (e) 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. [ka]

[0012] The component (A) contained in the encapsulating resin composition of the present invention is preferably a maleimide compound represented by the following formula (1) and / or a maleimide compound represented by the following formula (2). [ka] (In formula (1), A's are independently tetravalent organic groups having a cyclic structure; B's are independently divalent alicyclic hydrocarbon groups having 6 to 60 carbon atoms; D's are independently divalent hydrocarbon groups having 6 to 200 carbon atoms, at least one of which is a hydrocarbon group derived from a dimer acid skeleton; m is 1 to 100; and l is 1 to 200. The order of the repeating units bracketed by m and l is not limited, and the bonding pattern may be alternating, block, or random.) [ka] (In formula (2), A's are independently tetravalent organic groups having a cyclic structure, as in formula (1), D's are independently divalent hydrocarbon groups having 6 to 60 carbon atoms, as in formula (1), and at least one D is a hydrocarbon group derived from a dimer acid skeleton. n is 0 to 100.)

[0013] The maleimide compound represented by formula (1) has a higher glass transition temperature after curing than other maleimide compounds having a hydrocarbon group derived from a dimer acid skeleton, and therefore, when it is contained, it results in a highly reliable composition. Furthermore, compositions containing the maleimide compound represented by formula (1) have a lower elastic modulus after curing than compositions containing other common aromatic maleimide compounds, 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 hydrocarbon group derived from this dimer acid skeleton is contained in one molecule.

[0016] In addition, in the formula (1), each B is independently a divalent alicyclic hydrocarbon group having 6 to 60 carbon atoms, preferably a divalent aliphatic hydrocarbon group, and more preferably a divalent aliphatic hydrocarbon group having 6 to 30 carbon atoms. The aliphatic hydrocarbon group preferably has a cyclohexane skeleton, and the embodiment having the cyclohexane skeleton may be, for example, one having one cyclohexane ring, as represented by the following formula (3), or may be a polycyclic group having a plurality of cyclohexane rings bonded via an alkylene group or a bridged structure. [ka] (In formula (3), 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. 1 may 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 1 to 100, preferably 1 to 60, and more preferably 2 to 50, and l is 1 to 200, preferably 1 to 50, and more preferably 3 to 40. If m or l is too large, the flowability may decrease, and moldability may be poor. The order of the repeating units enclosed by m and l 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 composition containing the maleimide compound represented by formula (2) has a low elastic modulus after curing, reduces warpage of the substrate after encapsulation, and improves crack resistance in reliability tests. Furthermore, the composition containing the maleimide compound represented by formula (2) also has excellent dielectric properties at high frequencies.

[0021] In the formula (2), A is the same as A in the formula (1), and independently represents a tetravalent organic group having a cyclic structure, and similarly, a preferred one 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 (2).)

[0022] Similarly to D in formula (1), D in formula (2) is independently a divalent hydrocarbon group having 6 to 200 carbon atoms, preferably 8 to 100 carbon atoms, and more preferably 10 to 50 carbon atoms. Similar to D in formula (1), D in formula (2) is preferably a branched divalent hydrocarbon group in which one or more hydrogen atoms in the divalent hydrocarbon group are substituted with an alkyl or alkenyl group having 6 to 200 carbon atoms, preferably 8 to 100 carbon atoms, and more preferably 10 to 50 carbon atoms. 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 hydrocarbon group derived from this dimer acid skeleton is contained in one molecule.

[0023] In the formula (2), n is 0 to 100, preferably 0 to 60, and more preferably 0 to 50. If n is too large, the solubility and flowability may decrease, and moldability may be poor.

[0024] The maleimide compound of component (A) is preferably a solid at 25°C, as this provides ease of handling and minimizes warping after sealing.

[0025] The number average molecular weight of the maleimide 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, more preferably 900 to 30,000. Furthermore, component (A) may contain not only the maleimide compounds represented by formula (1) and / or (2) above, but also other maleimide compounds having one or more hydrocarbon groups derived from a dimer acid skeleton per molecule, and may use one type alone or multiple types in combination. 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.

[0026] [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)

[0027] [(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.

[0028] 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.

[0029] 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).

[0030] 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). When the amount of the reaction initiator is 0.1 part by mass or more, the curing reaction proceeds sufficiently, and when it is 8 parts by mass or less, the storage stability of the encapsulating resin composition is good.

[0031] [(C) Inorganic filler] (C) The inorganic filler is added to the encapsulating resin composition of the present invention to reduce the thermal expansion coefficient and improve the mechanical properties of the cured product. In the present invention, an inorganic filler having a maximum particle size of 40 μm or less and surface-treated with a silane coupling agent is used. Examples of inorganic fillers include silicas such as spherical silica, fused silica, crystalline silica, and cristobalite, alumina, silicon nitride, aluminum nitride, boron nitride, titanium oxide, glass fiber, and magnesium oxide. Further examples include fluororesin-containing fillers or fluororesin-coated fillers for improving dielectric properties. The average particle size and shape of these inorganic fillers can be selected depending on the application.

[0032] The maximum particle size of the (C) inorganic filler is the maximum value in the volume particle size distribution measured by a laser diffraction scattering measurement method, and the maximum particle size is 40 μm or less, preferably 30 μm or less, and more preferably 20 μm or less. If the maximum particle size is 40 μm or less, the surface roughness can be reduced even if the filler falls off when the surface of the cured product after encapsulation is ground.

[0033] The average particle size D50 of the inorganic filler (C) is preferably 0.1 to 20 μm, more preferably 0.15 to 10 μm, and even more preferably 0.2 to 8 μm, as measured by a volume particle size distribution measured by a laser diffraction scattering method.

[0034] (C) The inorganic filler may be top-cut if necessary. Here, "top-cut" refers to classifying the produced inorganic filler 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 40 μm, more preferably 1.5 to 30 μm, and even more preferably 2 to 20 μm.

[0035] The inorganic filler is used after surface treatment with a silane coupling agent in order to strengthen the bond between the resin component and the inorganic filler. Examples of the silane coupling agent 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. 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, relative to 100 parts by mass of the inorganic filler.

[0036] The amount of inorganic filler blended is preferably 10 to 2,000 parts by mass, more preferably 20 to 1,200 parts by mass, and even more preferably 40 to 1,000 parts by mass, based on 100 parts by mass of the total of the (A) component. Furthermore, the amount of inorganic filler blended 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. Within this range, the viscosity during molding does not become too high, and molding defects can be prevented.

[0037] <Other additives> The encapsulating 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.

[0038] [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 typically 0 to 60 mass% of the total thermosetting resin.

[0039] [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.

[0040] [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.

[0041] [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.

[0042] [Coloring agent] In the present invention, a colorant may be added to stabilize the color of the appearance after sealing. Examples of the colorant include carbon black, titanium black, titanium oxide, etc., and these may be used alone or in combination of two or more.

[0043] In addition to the above, an adhesive aid, a release agent, a reactive diluent, a light stabilizer, etc. may be added.

[0044] The encapsulating resin composition of the present invention can be produced by any conventional method. Examples of production methods include a planetary mixer, a heat roll, a kneader, and an extruder. When the resulting thermosetting resin composition is solid, it may be pulverized into a powder, or may be pulverized and then compressed into tablets. It may be granulated by pulverizing the composition and then filtering through a sieve to remove coarse particles and fine powder, or it may be formed into a sheet using a press or T-die. Alternatively, the encapsulating resin composition (varnish) dissolved in an organic solvent may be applied to a support sheet, and then heated at a temperature of typically 80°C or higher, preferably 100°C or higher, for 1 to 60 minutes to remove the organic solvent, resulting in an uncured film. Granular, sheet, and film forms are more preferred for ease of handling during use and to minimize the effects of dust contamination.

[0045] <Applications of the encapsulating resin composition> The encapsulating resin composition of the present invention is not particularly limited as long as it is used to encapsulate the semiconductor element mounting surface of a substrate carrying a semiconductor element or the semiconductor element forming surface of a wafer on which a semiconductor element is formed, but is effective as an encapsulating resin composition for wafer level packages, panel level packages, fan-out wafer level packages, and fan-out panel level packages. Furthermore, since the encapsulating resin composition of the present invention has low dielectric properties at high frequencies, it is also suitable for antenna-in-packages. The method for encapsulating a semiconductor device with the encapsulating resin composition of the present invention is not particularly limited, and conventional molding methods such as transfer molding, injection molding, compression molding, casting, lamination, etc. may be used, with compression molding being more preferred. [Example]

[0046] 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 shown below. The average particle size and maximum particle size are values ​​determined by the above-mentioned methods.

[0047] (A) A maleimide compound having one or more hydrocarbon groups derived from a dimer acid skeleton in one molecule. (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: 8000) [ka] -C 36 H 70 - indicates a structure derived from a dimer acid skeleton. n≒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, l≒2 (average value) Comparative maleimide compound (A'-3): Phenylmethanemaleimide (trade name: BMI-2300, manufactured by Daiwa Chemical Industry Co., Ltd.)

[0048] (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)

[0049] (C) Inorganic filler (C-1): Silica 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.) for 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 maximum particle size of 20 μm. (C-2): Silica that has been dry surface-treated with 0.3 parts by mass of 3-aminopropyltrimethoxysilane (trade name: KBM-903, manufactured by Shin-Etsu Chemical Co., Ltd.) for 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 maximum particle size of 20 μm. (C-3): Silica 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.) for 100 parts by mass of spherical silica (trade name: SO-25H, manufactured by Admatechs Co., Ltd.) having an average particle size of 0.5 μm and a maximum particle size of 5 μm Comparative inorganic filler (C'-4): Fused spherical silica with an average particle size of 4 μm and a maximum particle size of 20 μm (product name: MUF-4, manufactured by Tatsumori Co., Ltd.) (C'-5): Silica (trade name: RS-8225H / 53C, manufactured by Tatsumori Co., Ltd.) 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 fused spherical silica having an average particle size of 13 μm and a maximum particle size of 53 μm. (C'-6): Silica 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.) for 100 parts by mass of fused spherical silica (trade name: FB-5604FC, manufactured by Denka Co., Ltd.) having an average particle size of 27 μm and a maximum particle size of 55 μm

[0050] (D) Other thermosetting resins (D-1): Dicyclopentadiene-type epoxy resin (product name: HP-7200, manufactured by DIC Corporation)

[0051] (E) Silane coupling agent (E-1): N-phenyl-3-aminopropyltrimethoxysilane (trade name: KBM-573, manufactured by Shin-Etsu Chemical Co., Ltd.)

[0052] [Examples 1 to 9, Comparative Examples 1 to 5] The components were melt-mixed in the proportions (parts by mass) shown in Table 1, cooled, and pulverized, and then coarse particles and fine powder were removed using sieves with 2 mm and 0.5 mm openings to obtain granular resin compositions. Each composition was evaluated according to the methods described below, and the results are shown in Table 1.

[0053] <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).

[0054] <Surface roughness after grinding> 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 encapsulating resin surface of the wafer was ground to 20 μm using a grinding machine (manufactured by DISCO) under the following conditions. Wheels: #1500 resin bond wheels Spindle speed: 1300 rpm Chuck table rotation speed: 300 rpm Feed rate: 0.3μm / s The arithmetic mean roughness Ra of the sealing resin surface after grinding was measured under the following conditions using a laser microscope (manufactured by Keyence Corporation), and the average value was calculated. Measurement points: Two points 75 cm from the center of the 12-inch wafer after grinding ·Magnification: 20x Length: 500μm

[0055] <Crack resistance> A silicon chip (2 cm × 2 cm × 150 μm thick) with a die attach film (50 μm thick) was mounted on a 12-inch / 775 μm-thick silicon wafer using a flip-chip bonder (manufactured by Panasonic). The above resin composition was molded onto the wafer using a compression molding machine (manufactured by Apic Yamada) so that the resin thickness after molding was 400 μm. The molding temperature and molding time were as shown in Table 1. After post-curing at 180°C for 2 hours, the encapsulating resin surface of the wafer was ground using a grinding machine (manufactured by DISCO) until the silicon chip surface was exposed. Test pieces were then obtained by dicing into 2.2 cm × 2.2 cm pieces using a dicing machine (manufactured by DISCO). The test pieces were subjected to a temperature cycle test (-65°C to 150°C, 1000 cycles). A rating of × was given if cracks were observed in the resin after the temperature cycle test, and a rating of ◯ was given if no cracks were observed in the resin.

[0056] <Moisture resistance> The resin composition was thermally cured in a vacuum press (manufactured by Nikko Materials) at the molding temperature and for the molding time listed in Table 1 to obtain a cured product measuring 50 mm in diameter and 3 mm in thickness. The cured product was post-cured at 180°C for 2 hours and then stored in a thermo-hygrostat at 85°C and 85% RH for 168 hours, after which the mass after storage was measured. The moisture absorption rate was evaluated as [(mass of cured product after storage - mass of cured product before storage) / mass of cured product before storage] x 100 (%).

[0057] <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 and dielectric loss tangent at a frequency of 10 GHz were measured using a network analyzer (manufactured by Keysight) connected to a strip line (manufactured by Keycom).

[0058] [Table 1]

[0059] As shown in Table 1, the resin composition of the present invention minimizes warpage after molding, has small surface roughness after grinding, and is excellent in crack resistance, moisture resistance, and dielectric properties. Therefore, the encapsulating resin composition of the present invention is suitable for use in encapsulating the semiconductor element mounting surface of a substrate on which a semiconductor element is mounted or the semiconductor element forming surface of a wafer on which a semiconductor element is formed.

Claims

1. A resin composition for sealing a semiconductor element mounting surface of a substrate on which a semiconductor element is mounted or a semiconductor element forming surface of a wafer on which a semiconductor element is formed, (A) A maleimide compound having one or more hydrocarbon groups derived from a dimer acid skeleton in one molecule (B) Reaction initiator and (C) Inorganic filler surface-treated with a silane coupling agent the component (B) is a thermal radical polymerization initiator and / or an anionic polymerization initiator, and the maximum particle size of the component (C) is 40 μm or less, The encapsulating resin composition is for use in 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.

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

3. 3. The encapsulating resin composition according to claim 2, wherein A in formula (1) and formula (2) is any one of tetravalent organic groups represented by the following structural formulas: 【Transformation 3】

4. 4. The encapsulating resin composition according to claim 1, wherein the silane coupling agent used to treat the surface of the inorganic filler (C) is one or more aminosilanes selected from the group consisting of 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.

5. 4. The encapsulating resin composition according to claim 1, wherein the content of the component (C) is 30 to 95 mass % of the total mass of the composition.

6. The encapsulating resin composition according to any one of claims 1 to 3, which is in the form of granules, a sheet or a film.

7. A semiconductor device comprising a cured product of the encapsulating resin composition according to any one of claims 1 to 3.

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