Sealing resin composition, repositioned wafer, semiconductor package, and method for producing semiconductor package

Abstract

A sealing resin composition which comprises a curable resin component, a (meth)acrylic copolymer, and a filler, wherein the (meth)acrylic copolymer comprises a first polymer chain that includes a constituent unit derived from methyl methacrylate and a second polymer chain that includes a constituent unit derived from n-butyl acrylate.

Description

Encapsulating resin composition, rearrangement wafer, semiconductor package, and method for manufacturing semiconductor package

[0001] The present invention relates to an encapsulating resin composition, a relocation wafer, a semiconductor package, and a method for manufacturing a semiconductor package.

[0002] In recent years, a technique called wafer level packaging (WLP) has been considered as a semiconductor packaging technology using a resin encapsulant. Unlike flip-chip techniques in which packaging is performed with a semiconductor chip connected to a wiring substrate, this technique does not require a wiring substrate, making it possible to reduce the thickness of the package. Furthermore, because multiple semiconductor chips are placed on a support, encapsulated together, and then separated into individual packages, this technique has attracted attention as a packaging technology with excellent productivity.

[0003] In WLP, one side of a relatively large support is sealed with a sealing material, which makes it prone to warping due to differences in the thermal expansion coefficient, elastic modulus, shrinkage rate, etc. between the sealing material and the support. Increasing the amount of filler has been considered as a means of suppressing warping of the support after sealing (see, for example, Patent Document 1).

[0004] JP 2013-10940 A

[0005] Increasing the amount of filler in the encapsulant reduces the thermal expansion coefficient of the encapsulant, reducing the difference with the thermal expansion coefficient of the support, thereby suppressing warping of the support, but when the area of ​​the support is large, the effect of suppressing warping may not be sufficient. It is desirable to suppress warping of the support after encapsulation by a method other than increasing the amount of filler in the encapsulant.

[0006] In view of the above circumstances, an object of the present disclosure is to provide an encapsulating resin composition that suppresses warping of a support after encapsulation, a rearrangement wafer and a semiconductor package obtained using the same, and a method for manufacturing a semiconductor package that suppresses warping of a support after encapsulation.

[0007] <1> An encapsulating resin composition comprising a curable resin component, a (meth)acrylic copolymer, and a filler, wherein the (meth)acrylic copolymer comprises a first polymer chain containing a structural unit derived from methyl methacrylate and a second polymer chain containing a structural unit derived from n-butyl acrylate. <2> The encapsulating resin composition according to <1>, wherein the mass ratio of the first polymer chain to the second polymer chain, i.e., first polymer chain:second polymer chain, is 1:9 to 5:5. <3> The encapsulating resin composition according to <1> or <2>, wherein the curable resin component comprises an epoxy resin, and wherein a content of the (meth)acrylic copolymer is 30 mass% or less with respect to the total amount of the epoxy resin. <4> The encapsulating resin composition according to any one of <1> to <3>, wherein the curable resin component comprises an epoxy resin, and wherein the epoxy resin comprises a biphenyl-type epoxy resin. <5> The encapsulating resin composition according to any one of <1> to <4>, wherein the curable resin component comprises a curing agent, and wherein the curing agent comprises a triphenylmethane-type phenolic resin. <6> The encapsulating resin composition according to any one of <1> to <5>, wherein the filler content is 30% by volume to 90% by volume. <7> The encapsulating resin composition according to any one of <1> to <6>, which is used for wafer-level packaging. <8> The encapsulating resin composition according to any one of <1> to <7>, which is used for FO-WLP. <9> The encapsulating resin composition according to any one of <1> to <8>, which is used for encapsulation by compression molding. <10> The encapsulating resin composition according to any one of <1> to <9>, which is in powder form. <11> A rearrangement wafer comprising a support, a plurality of semiconductor chips arranged on the support, and a cured product of the encapsulating resin composition according to any one of <1> to <10> encapsulating the semiconductor chips. <12> A semiconductor package comprising a support, a semiconductor chip arranged on the support, and a cured product of the encapsulating resin composition according to any one of <1> to <10> encapsulating the semiconductor chips.<13> A method for manufacturing a semiconductor package, comprising: a step of arranging a plurality of semiconductor chips on a support; a step of arranging the encapsulating resin composition according to any one of <1> to <10> on the support on which the semiconductor chips are arranged; a step of curing the encapsulating resin composition arranged on the support to encapsulate the semiconductor chips; and a step of singulating the semiconductor chips.

[0008] According to the present disclosure, there are provided an encapsulating resin composition that suppresses warping of a support after encapsulation, a rearrangement wafer and a semiconductor package obtained using the same, and a method for manufacturing a semiconductor package that suppresses warping of a support after encapsulation.

[0009] Hereinafter, embodiments for carrying out the present invention will be described in detail. However, the present invention is not limited to the following embodiments. In the following embodiments, components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values ​​and their ranges, and do not limit the present invention.

[0010] In the present disclosure, the term "process" includes not only processes that are independent of other processes, but also processes that cannot be clearly distinguished from other processes as long as the purpose of the process is achieved. In the present disclosure, numerical ranges indicated using "to" include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in the present disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another staged numerical range. Furthermore, in numerical ranges described in the present disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples. In the present disclosure, each component may contain multiple corresponding substances. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, each component may contain multiple types of particles. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified.

[0011] <Encapsulating Resin Composition> The encapsulating resin composition of the present embodiment includes a curable resin component, a (meth)acrylic copolymer, and a filler, and the (meth)acrylic copolymer includes a first polymer chain including a structural unit derived from methyl methacrylate and a second polymer chain including a structural unit derived from n-butyl acrylate.

[0012] The inventors' investigations have revealed that an encapsulating resin composition having the above-described configuration suppresses warpage of a support after encapsulation. While the reason for this is not entirely clear, the inclusion of a (meth)acrylic copolymer increases the amount of low-elasticity components in the encapsulating resin composition, which tends to reduce the elasticity (e.g., elastic modulus at 260°C) of the cured product. This is presumably responsible for the reduction in warpage. One possible reason for the reduction in elasticity is the presence of phase-separated (meth)acrylic copolymers in the resin matrix formed by the curable resin component, in the form of islands. Furthermore, the inclusion of a (meth)acrylic copolymer in the encapsulating resin composition reduces the proportion of the curable resin component relatively. As a result, an encapsulating resin composition is obtained that exhibits low elasticity while suppressing an increase in the thermal expansion coefficient, thereby exhibiting excellent warpage suppression effects.

[0013] In the present disclosure, the elastic modulus at 25°C when the encapsulating resin composition is cured is a value measured by the method described in the Examples. From the viewpoint of suppressing warpage of the support, the elastic modulus is preferably 21.0 GPa or less, more preferably 20.0 GPa or less, even more preferably 19.0 GPa or less, and particularly preferably 18.0 GPa or less. The elastic modulus may be 10.0 GPa or more, or may be 15.0 GPa or more.

[0014] In the present disclosure, the elastic modulus at 260°C when the encapsulating resin composition is cured is a value measured by the method described in the Examples. From the viewpoint of suppressing warpage of the support, the elastic modulus is preferably 1.5 GPa or less, more preferably 1.2 GPa or less, even more preferably 1.0 GPa or less, and particularly preferably 0.8 GPa or less. The elastic modulus may be 0.1 GPa or more, or may be 0.3 GPa or more.

[0015] The encapsulating resin composition may be solid or liquid. When the encapsulating resin composition is solid, the form may be powder, tablet, or the like. From the viewpoint of handleability, the encapsulating resin composition is preferably solid when used, and more preferably powder.

[0016] ((Meth)acrylic copolymer) The (meth)acrylic copolymer includes a first polymer chain including a structural unit derived from methyl methacrylate and a second polymer chain including a structural unit derived from n-butyl acrylate. The (meth)acrylic copolymer may be a random copolymer or a block copolymer.

[0017] The first polymer chain may contain a structural unit derived from methyl methacrylate, and is preferably a polymethyl methacrylate chain (PMMA chain) containing a plurality of structural units derived from methyl methacrylate. The first polymer chain may or may not contain a structural unit other than the structural unit derived from methyl methacrylate.

[0018] The content of the structural units derived from methyl methacrylate contained in the first polymer chain may be 50% by mass to 100% by mass, 70% by mass to 100% by mass, or 90% by mass to 100% by mass, relative to all structural units in the first polymer chain.

[0019] When the first polymer chain contains a structural unit (other structural unit (1)) other than a structural unit derived from methyl methacrylate, examples of the other structural unit (1) include a structural unit derived from at least one compound selected from ethylenically unsaturated carboxylic acid esters such as methyl acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, (meth)acrylonitrile, and hydroxyethyl (meth)acrylate, and ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, and maleic acid.

[0020] The second polymer chain may contain a structural unit derived from n-butyl acrylate. For example, the second polymer chain is preferably a poly-n-butyl acrylate chain (PnBA chain) containing a plurality of structural units derived from n-butyl acrylate, or a polymer chain (P(nBA / 2EHA) chain) containing a plurality of structural units derived from n-butyl acrylate and a plurality of structural units derived from 2-ethylhexyl acrylate.

[0021] When the second polymer chain contains a structural unit (other structural unit (2)) other than a structural unit derived from n-butyl acrylate and a structural unit derived from 2-ethylhexyl acrylate, examples of the other structural unit (2) include a structural unit derived from at least one compound selected from ethylenically unsaturated carboxylic acid esters such as ethyl (meth)acrylate, butyl methacrylate, (meth)acrylonitrile, and hydroxyethyl (meth)acrylate, and ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid, and maleic acid.

[0022] In the present disclosure, when a (meth)acrylic copolymer is a compound that also corresponds to a curable resin component (for example, when a (meth)acrylic copolymer has a functional group that causes a curing reaction, such as an epoxy group), the compound is classified as a (meth)acrylic copolymer.

[0023] The (meth)acrylic copolymer is preferably a triblock copolymer of PMMA chain-PnBA chain-PMMA chain or a triblock copolymer of PMMA chain-P(nBA / 2EHA) chain-PMMA chain.

[0024] In the (meth)acrylic copolymer, the mass ratio of the first polymer chain to the second polymer chain, that is, first polymer chain:second polymer chain, is preferably 1:9 to 5:5, more preferably 1.5:8.5 to 4:6, even more preferably 2:8 to 3:7, and particularly preferably 2:8 to 2.5:7.5. The proportion of the (meth)acrylic copolymer in which the ratio of the first polymer chain to the second polymer chain satisfies the above-mentioned numerical range (preferably a (meth)acrylic copolymer in which the ratio of the first polymer chain to the second polymer chain is 2:8 to 2.5:7.5) may be 50% by mass to 100% by mass, 70% by mass to 100% by mass, or 90% by mass to 100% by mass, based on the total amount of the (meth)acrylic copolymer.

[0025] (Curable Resin Component) The type of curable resin component contained in the encapsulating resin composition is not particularly limited. From the viewpoint of a balance of various properties as an encapsulant, a combination of an epoxy resin and a curing agent is preferred.

[0026] The type of epoxy resin is not particularly limited and can be selected depending on the desired properties of the encapsulating resin composition. Specific examples of epoxy resins include novolac epoxy resins (phenol novolac epoxy resins, orthocresol novolac epoxy resins, etc.) obtained by epoxidizing novolac resins obtained by condensing or co-condensing, under an acidic catalyst, at least one phenolic compound selected from the group consisting of phenolic compounds such as phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, and naphthol compounds such as α-naphthol, β-naphthol, and dihydroxynaphthalene with an aliphatic aldehyde compound such as formaldehyde, acetaldehyde, and propionaldehyde; triphenylmethane epoxy resins obtained by epoxidizing triphenylmethane phenolic resins obtained by condensing or co-condensing, under an acidic catalyst, the above-mentioned phenolic compounds with aromatic aldehyde compounds such as benzaldehyde and salicylaldehyde; and novolac resins obtained by co-condensing, under an acidic catalyst, the above-mentioned phenolic compounds and naphthol compounds with an aldehyde compound. diphenylmethane-type epoxy resins which are diglycidyl ethers of bisphenol A, bisphenol F, or the like; biphenyl-type epoxy resins which are diglycidyl ethers of alkyl-substituted or unsubstituted biphenols; stilbene-type epoxy resins which are diglycidyl ethers of stilbene-based phenolic compounds; sulfur-containing epoxy resins which are diglycidyl ethers of bisphenol S, or the like; epoxy resins which are glycidyl ethers of alcohols such as butanediol, polyethylene glycol, and polypropylene glycol; glycidyl ester-type epoxy resins which are glycidyl esters of polycarboxylic acids such as phthalic acid, isophthalic acid, and tetrahydrophthalic acid; glycidylamine-type epoxy resins in which active hydrogen bonded to nitrogen atoms of aniline, diaminodiphenylmethane, isocyanuric acid, or the like is substituted with a glycidyl group; and dicyclopentadiene-type epoxy resins in which a co-condensation resin of dicyclopentadiene and a phenolic compound is epoxidized.Alicyclic epoxy resins such as vinylcyclohexene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, and 2-(3,4-epoxy)cyclohexyl-5,5-spiro(3,4-epoxy)cyclohexane-m-dioxane, which are produced by epoxidizing an intramolecular olefin bond; paraxylylene-modified epoxy resins, which are glycidyl ethers of paraxylylene-modified phenolic resins; metaxylylene-modified epoxy resins, which are glycidyl ethers of metaxylylene-modified phenolic resins; terpene-modified epoxy resins, which are glycidyl ethers of terpene-modified phenolic resins; and dicyclopentadiene-modified phenolic resins, which are glycidyl ethers of dicyclopentadiene-modified phenolic resins. Examples of suitable epoxy resins include pentadiene-modified epoxy resins, cyclopentadiene-modified epoxy resins which are glycidyl ethers of cyclopentadiene-modified phenolic resins, polycyclic aromatic ring-modified epoxy resins which are glycidyl ethers of polycyclic aromatic ring-modified phenolic resins, naphthalene-type epoxy resins which are glycidyl ethers of naphthalene ring-containing phenolic resins, halogenated phenol novolac-type epoxy resins, hydroquinone-type epoxy resins, trimethylolpropane-type epoxy resins, linear aliphatic epoxy resins obtained by oxidizing olefin bonds with peracids such as peracetic acid, and aralkyl-type epoxy resins obtained by epoxidizing aralkyl-type phenolic resins such as phenol aralkyl resins and naphthol aralkyl resins. These epoxy resins may be used alone or in combination of two or more.

[0027] When the curable resin component contains an epoxy resin, the epoxy resin may contain a biphenyl-type epoxy resin or a triphenylmethane-type epoxy resin.

[0028] The epoxy equivalent (molecular weight / number of epoxy groups) of the epoxy resin is not particularly limited, but from the viewpoint of a balance of various properties such as moldability, reflow resistance, and electrical reliability, it is preferably 100 g / eq to 1000 g / eq, and more preferably 150 g / eq to 500 g / eq.

[0029] The epoxy equivalent of the epoxy resin may be a value measured by a method in accordance with JIS K 7236:2009, for example.

[0030] When the epoxy resin is solid, its softening point or melting point is not particularly limited, but is preferably 50°C to 130°C from the viewpoint of ease of handling during preparation of the encapsulating resin composition.

[0031] The melting point or softening point of the epoxy resin is a value measured by differential scanning calorimetry (DSC) or a method in accordance with JIS K 7234:1986 (ring and ball method).

[0032] When the curable resin component contains an epoxy resin, the content of the (meth)acrylic copolymer is preferably 30% by mass or less, relative to the total amount of the epoxy resin, from the viewpoint of reducing the viscosity of the composition, and is preferably 3% by mass or more, more preferably 5% by mass or more, even more preferably 7% by mass or more, and particularly preferably 10% by mass or more, from the viewpoint of reducing warpage.

[0033] (Curing Agent) The type of curing agent is not particularly limited and can be selected depending on the desired properties of the encapsulating resin composition. When the resin used in combination is an epoxy resin, examples of the curing agent include a phenol curing agent, an amine curing agent, an acid anhydride curing agent, a polymercaptan curing agent, a polyaminoamide curing agent, an isocyanate curing agent, and a blocked isocyanate curing agent. From the viewpoint of heat resistance, the curing agent is preferably one having a phenolic hydroxyl group in the molecule (phenol curing agent).

[0034] Specific examples of the phenolic curing agent include polyhydric phenolic compounds such as resorcinol, catechol, bisphenol A, bisphenol F, and substituted or unsubstituted biphenols; novolak-type phenolic resins obtained by condensing or co-condensing at least one phenolic compound selected from the group consisting of phenolic compounds such as phenol, cresol, xylenol, resorcinol, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol, and naphthol compounds such as α-naphthol, β-naphthol, and dihydroxynaphthalene, with an aliphatic aldehyde compound such as formaldehyde, acetaldehyde, and propionaldehyde, under an acidic catalyst; and resins synthesized from the above phenolic compounds and dimethoxyparaxylene, bis(methoxymethyl)biphenyl, etc. Examples of the phenolic curing agent include aralkyl-type phenolic resins such as phenol aralkyl resins and naphthol aralkyl resins; phenolic resins modified with at least one of paraxylylene and metaxylylene; melamine-modified phenolic resins; terpene-modified phenolic resins; dicyclopentadiene-type phenolic resins and dicyclopentadiene-type naphthol resins synthesized by copolymerization of the above-mentioned phenolic compounds with dicyclopentadiene; cyclopentadiene-modified phenolic resins; polycyclic aromatic ring-modified phenolic resins; biphenyl-type phenolic resins; triphenylmethane-type phenolic resins obtained by condensation or co-condensation of the above-mentioned phenolic compounds with aromatic aldehyde compounds such as benzaldehyde and salicylaldehyde under an acidic catalyst; and phenolic resins obtained by copolymerization of two or more of these. These phenolic curing agents may be used alone or in combination of two or more.

[0035] When the curable resin component contains a curing agent, the curing agent preferably contains a triphenylmethane type phenolic resin.

[0036] The functional group equivalent of the curing agent (hydroxyl group equivalent in the case of a phenolic curing agent) is not particularly limited, but from the viewpoint of the balance of various properties such as moldability, reflow resistance, and electrical reliability, it is preferably 70 g / eq to 1000 g / eq, and more preferably 80 g / eq to 500 g / eq.

[0037] The functional group equivalent of the curing agent (hydroxyl group equivalent in the case of a phenolic curing agent) may be a value measured by a method in accordance with JIS K 0070:1992, for example.

[0038] When the curing agent is solid, its softening point or melting point is not particularly limited, but is preferably 40°C to 180°C from the viewpoint of moldability and reflow resistance, and more preferably 50°C to 130°C from the viewpoint of handleability during production of the encapsulating resin composition.

[0039] The melting point or softening point of the curing agent is a value measured in the same manner as the melting point or softening point of the epoxy resin.

[0040] The equivalent ratio between the curable resin and the curing agent, i.e., the ratio of the number of functional groups in the curing agent to the number of functional groups in the curable resin (number of functional groups in the curing agent / number of functional groups in the curable resin), is not particularly limited. In order to minimize the amount of unreacted components, it is preferably set in the range of 0.5 to 2.0, and more preferably in the range of 0.6 to 1.3. From the viewpoints of moldability and reflow resistance, it is even more preferably set in the range of 0.8 to 1.2.

[0041] (Filler) The type of filler is not particularly limited. Specific examples include inorganic materials such as silica (fused silica, crystalline silica, etc.), glass, alumina, calcium carbonate, zirconium silicate, calcium silicate, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, fosterite, steatite, spinel, mullite, titania, talc, clay, and mica. A filler having a flame-retardant effect may also be used. Examples of the filler having a flame-retardant effect include aluminum hydroxide, magnesium hydroxide, composite metal hydroxides such as composite hydroxides of magnesium and zinc, and zinc borate.

[0042] Among the above fillers, silica is preferred from the viewpoint of reducing the linear expansion coefficient, and alumina is preferred from the viewpoint of high thermal conductivity. One filler may be used alone, or two or more fillers may be used in combination. The filler may be in the form of powder, beads formed by spheroidizing powder, fiber, etc.

[0043] The content of the filler contained in the encapsulating resin composition is not particularly limited. From the viewpoint of fluidity and strength, it is preferably 30% to 90% by volume of the entire encapsulating resin composition, more preferably 35% to 80% by volume, and even more preferably 40% to 70% by volume. When the filler content is 30% by volume or more of the entire encapsulating resin composition, the properties of the cured product, such as the thermal expansion coefficient, thermal conductivity, and elastic modulus, tend to be further improved. When the filler content is 90% by volume or less of the entire encapsulating resin composition, an increase in the viscosity of the encapsulating resin composition is suppressed, and the fluidity tends to be further improved, resulting in better moldability. The content of the filler contained in the encapsulating resin composition may be 50% to 90% by volume, 60% to 85% by volume, or 70% to 80% by volume.

[0044] When the filler is particulate, its average particle diameter is not particularly limited. For example, the volume average particle diameter is preferably 0.2 μm to 20 μm, and more preferably 0.5 μm to 15 μm. When the volume average particle diameter is 0.2 μm or more, the increase in viscosity of the encapsulating resin composition tends to be further suppressed. When the volume average particle diameter is 20 μm or less, the filling ability into narrow gaps tends to be further improved. The volume average particle diameter of the filler can be measured as the particle diameter (D50) at which the cumulative volume from the small diameter side reaches 50% in the volume-based particle size distribution obtained using a laser scattering diffraction particle size distribution analyzer.

[0045] (Curing Accelerator) The encapsulating resin composition may contain a curing accelerator. The type of curing accelerator is not particularly limited and can be selected depending on the type of curable resin, the desired properties of the encapsulating resin composition, and the like. Examples of the curing accelerator include diazabicycloalkenes such as 1,5-diazabicyclo[4.3.0]nonene-5 (DBN) and 1,8-diazabicyclo[5.4.0]undecene-7 (DBU), cyclic amidine compounds such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 2-heptadecylimidazole; derivatives of the cyclic amidine compounds; phenol novolac salts of the cyclic amidine compounds or their derivatives; quinone compounds such as maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, and phenyl-1,4-benzoquinone; compounds having intramolecular polarization obtained by adding a compound having a π bond, such as 2-isophenylmethane; cyclic amidinium compounds such as the tetraphenylborate salt of DBU, the tetraphenylborate salt of DBN, the tetraphenylborate salt of 2-ethyl-4-methylimidazole, and the tetraphenylborate salt of N-methylmorpholine; tertiary amine compounds such as pyridine, triethylamine, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol; derivatives of the above tertiary amine compounds; ammonium salt compounds such as tetra-n-butylammonium acetate, tetra-n-butylammonium phosphate, tetraethylammonium acetate, tetra-n-hexylammonium benzoate, and tetrapropylammonium hydroxide;Triphenylphosphine, diphenyl(p-tolyl)phosphine, tris(alkylphenyl)phosphine, tris(alkoxyphenyl)phosphine, tris(alkyl / alkoxyphenyl)phosphine, tris(dialkylphenyl)phosphine, tris(trialkylphenyl)phosphine, tris(tetraalkylphenyl)phosphine, tris(dialkoxyphenyl)phosphine, tris(trialkoxyphenyl)phosphine, tris(tetraalkoxyphenyl)phosphine, trialkylphosphine, dialkyla tertiary phosphines such as alkyldiarylphosphines and alkyldiarylphosphines; phosphine compounds such as complexes of the above tertiary phosphines with organoborons; quinone compounds such as the above tertiary phosphines or the above phosphine compounds with maleic anhydride, 1,4-benzoquinone, 2,5-toluquinone, 1,4-naphthoquinone, 2,3-dimethylbenzoquinone, 2,6-dimethylbenzoquinone, 2,3-dimethoxy-5-methyl-1,4-benzoquinone, 2,3-dimethoxy-1,4-benzoquinone, and phenyl-1,4-benzoquinone, and diazophenylmethane. or a compound having intramolecular polarization obtained by adding a compound having a π bond to the tertiary phosphine or the phosphine compound; a compound obtained by adding the above-mentioned tertiary phosphine or the above-mentioned phosphine compound to 4-bromophenol, 3-bromophenol, 2-bromophenol, 4-chlorophenol, 3-chlorophenol, 2-chlorophenol, 4-iodophenol, 3-iodophenol, 2-iodophenol, 4-bromo-2-methylphenol, 4-bromo-3-methylphenol, 4-bromo-2,6-dimethylphenol, 4-bromo-3,5-dimethylphenol, 4-bromo-2,6-di-t-butylphenol, compounds having intramolecular polarization obtained by reacting a halogenated phenol compound such as 1-bromo-2-naphthol, 4-chloro-1-naphthol, 1-bromo-2-naphthol, 6-bromo-2-naphthol, or 4-bromo-4'-hydroxybiphenyl, followed by a dehydrohalogenation step; tetra-substituted phosphonium compounds such as tetraphenylphosphonium, tetra-substituted phosphonium compounds and tetra-substituted borates having no phenyl group bonded to the boron atom such as tetra-p-tolylborate, and salts of tetraphenylphosphonium compounds;

[0046] When the encapsulating resin composition contains a curing accelerator, the amount thereof is preferably 0.1 to 30 parts by mass, and more preferably 1 to 15 parts by mass, per 100 parts by mass of the curable resin component.

[0047] [Various Additives] In addition to the components described above, the encapsulating resin composition may contain various additives such as a coupling agent, a release agent, a colorant, a stress relaxation agent, etc. The encapsulating resin composition may contain various additives known in the art, as needed, in addition to the additives exemplified below.

[0048] (Coupling Agent) The encapsulating resin composition may contain a coupling agent to enhance adhesion between the resin component and the filler. Examples of the coupling agent include known coupling agents such as silane compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, and vinylsilane, titanium compounds, aluminum chelate compounds, and aluminum / zirconium compounds. Among these, silane compounds are preferred from the viewpoint of ease of handling. The coupling agent may be used alone or in combination of two or more.

[0049] When the encapsulating resin composition contains a coupling agent, the amount of the coupling agent is preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 2.5 parts by mass, per 100 parts by mass of the filler.

[0050] (Mold Release Agent) The encapsulating resin composition may contain a mold release agent from the viewpoint of obtaining good mold releasability during molding. There are no particular limitations on the mold release agent, and conventionally known ones can be used. Specific examples include carnauba wax, higher fatty acids such as montanic acid and stearic acid, higher fatty acid metal salts, ester waxes such as montanic acid esters, and polyolefin waxes such as oxidized polyethylene and non-oxidized polyethylene. One type of mold release agent may be used alone, or two or more types may be used in combination.

[0051] When the encapsulating resin composition contains a release agent, the amount thereof is preferably 0.01 parts by mass to 10 parts by mass, and more preferably 0.1 parts by mass to 5 parts by mass, relative to 100 parts by mass of the total of the curable resin component and the (meth)acrylic copolymer.

[0052] (Colorant) The encapsulating resin composition may further contain a colorant. Examples of the colorant include known colorants such as carbon black, organic dyes, organic pigments, titanium oxide, red lead, and red iron oxide. The content of the colorant can be appropriately selected depending on the purpose, etc. The colorant may be used alone or in combination of two or more.

[0053] When the encapsulating resin composition contains a colorant, the amount of the colorant is preferably 0.01 parts by mass to 10 parts by mass, and more preferably 0.1 parts by mass to 5 parts by mass, relative to 100 parts by mass of the total of the curable resin component and the (meth)acrylic copolymer.

[0054] (Stress Relaxant) The encapsulating resin composition may further contain a stress relaxation agent (excluding the aforementioned (meth)acrylic copolymer). Examples of the stress relaxation agent include silicone oil; thermoplastic elastomers such as silicone, styrene, olefin, urethane, polyester, polyether, polyamide, and polybutadiene elastomers; rubber particles such as NR (natural rubber), NBR (acrylonitrile-butadiene rubber), urethane rubber, and silicone powder; rubber particles having a core-shell structure such as methyl methacrylate-styrene-butadiene copolymer (MBS) and methyl methacrylate-silicone copolymer, indene-styrene-coumarone copolymer, trialkylphosphine oxide, and triarylphosphine oxide. When the encapsulating resin composition contains a stress relaxation agent, the encapsulating resin composition may use one type of stress relaxation agent alone, or two or more types may be used in combination. Commercially available flexibility-imparting agents may be used as the stress relaxation agent.

[0055] When the encapsulating resin composition contains a stress relaxation agent, the amount thereof is preferably 0.1 parts by mass to 30 parts by mass, more preferably 1 part by mass to 25 parts by mass, and even more preferably 5 parts by mass to 20 parts by mass, relative to 100 parts by mass of the total of the curable resin component and the (meth)acrylic copolymer.

[0056] (Uses of Encapsulating Resin Composition) The above-described encapsulating resin composition can be used in various packaging techniques. The encapsulating resin composition of this embodiment is excellent in suppressing warpage of the support, and is therefore suitable for use in packaging techniques that encapsulate a relatively large area (for example, a packaging step that is performed before the package is divided into individual pieces). Examples of such packaging techniques include wafer-level packages such as FO-WLP (Fan Out Wafer Level Package) and FI-WLP (Fan In Wafer Level Package).

[0057] Methods for encapsulating a semiconductor chip with an encapsulating resin composition include compression molding, transfer molding, injection molding, and the like, and any of these can be employed.

[0058] The material of the support when using the encapsulating resin composition for encapsulation is not particularly limited. Examples include semiconductors such as silicon, glass, and ceramics. The shape of the support is not particularly limited, and it may be a disk (wafer) or other shapes. The area of ​​the support is not particularly limited, but since the encapsulating resin composition of this embodiment is excellent in suppressing the warping of the support, it may have a relatively large area. For example, it may be a wafer with a diameter of 12 inches or more.

[0059] The encapsulation thickness when encapsulating using the encapsulating resin composition is not particularly limited and can be selected depending on the size of the semiconductor chip to be encapsulated, etc. The encapsulating resin composition of the present embodiment is excellent in the effect of suppressing warpage of the support, and therefore can be suitably used even when the encapsulation thickness is large (for example, 200 μm to 1000 μm).

[0060] <Relocation wafer and semiconductor package> The relocation wafer of this embodiment includes a support, a plurality of semiconductor chips arranged on the support, and a cured product of the above-described encapsulating resin composition that encapsulates the semiconductor chips. The semiconductor package of this embodiment includes a support, a semiconductor chip arranged on the support, and a cured product of the above-described encapsulating resin composition that encapsulates the semiconductor chips. The semiconductor package can be obtained, for example, by dividing the above-described relocation wafer into individual pieces.

[0061] The rearrangement wafer of this embodiment is suppressed in warpage of the support. Therefore, even if the support has a relatively large area, it can be suitably used for manufacturing semiconductor packages. For example, the support may be a wafer with a diameter of 12 inches or more.

[0062] The thickness of the cured product of the encapsulating resin composition that encapsulates the semiconductor chip is not particularly limited and can be selected depending on the size of the semiconductor chip to be encapsulated, etc. The encapsulating resin composition of the present embodiment is excellent in the effect of suppressing warpage of the support, and is therefore suitable for use even when the encapsulation thickness is large (for example, 200 μm to 1000 μm).

[0063] The types of support and semiconductor chip used in the relocation wafer and semiconductor package are not particularly limited, and can be selected from those commonly used.

[0064] <Method for manufacturing semiconductor package> The method for manufacturing a semiconductor package of this embodiment includes the steps of: arranging a plurality of semiconductor chips on a support; arranging the above-described encapsulating resin composition on the support on which the semiconductor chips are arranged; curing the encapsulating resin composition arranged on the support to encapsulate the semiconductor chips; and singulating the support.

[0065] In the method for manufacturing a semiconductor package according to the present embodiment, warping of the support is suppressed after the encapsulating resin composition is cured to encapsulate the semiconductor chip, which reduces the occurrence of misalignment and the like in post-encapsulation steps, resulting in a high product yield.

[0066] The method for disposing the encapsulating resin composition on the support on which the semiconductor chip is disposed is not particularly limited. For example, when the encapsulating resin composition is in a powder form, the encapsulating resin composition may be sprayed on the support.

[0067] The method for curing the encapsulating resin composition disposed on the support to encapsulate the semiconductor chip is not particularly limited. For example, compression molding is preferred. Compression molding can be performed using a compression molding machine under predetermined conditions of pressure (e.g., 2 MPa to 10 MPa), temperature (e.g., 120°C to 150°C), and time (e.g., 200 seconds to 900 seconds).

[0068] The above-mentioned embodiment will be specifically explained below using examples, but the scope of the above-mentioned embodiment is not limited to these examples. In the table, "-" means that the evaluation has not been carried out.

[0069] Example 1 Preparation of Encapsulating Resin Composition The components shown in Table 1 were mixed in the amounts (parts by mass) shown in Table 1 to prepare an encapsulating resin composition. For preparation, a kneader, planetary mixer, three-roll mill, twin-screw extruder, or the like is preferably used. In this example, after mixing the materials, the mixture was kneaded using a twin-screw extruder with the internal temperature adjusted to 70°C to 100°C, cooled, and then pulverized to obtain an encapsulating resin composition. Details of each component are as follows:

[0070] Epoxy resin 1...triphenylmethane type epoxy resin, epoxy equivalent 163 g / eq to 175 g / eq, softening point 57°C to 63°C Epoxy resin 2...biphenyl type epoxy resin, epoxy equivalent 196 g / eq

[0071] Curing agent 1... Triphenylmethane type phenolic resin (hydroxyl group equivalent 104 g / eq) Curing accelerator: Triphenylphosphine / 1,4-benzoquinone adduct Coupling agent 1: N-phenyl-3-aminopropyltrimethoxysilane Coupling agent 2: 3-glycidoxypropyltrimethoxysilane Colorant 1... Carbon black, trade name "MA600", Mitsubishi Chemical Corporation Stress relaxation agent 1... Block copolymer of polymethyl methacrylate (PMMA)-poly-n-butyl acrylate (PnBA)-polymethyl methacrylate (PMMA), PMMA ratio: 10% by mass Stress relaxation agent 2... Block copolymer of polymethyl methacrylate (PMMA)-poly-n-butyl acrylate (PnBA)-polymethyl methacrylate (PMMA), PMMA ratio: 10% by mass Stress relaxation agent 3... Block copolymer of polymethyl methacrylate (PMMA)-poly(n-butyl acrylate / 2-ethylhexyl acrylate)-polymethyl methacrylate (PMMA), PMMA ratio: 15% by mass Stress relaxation agent 4... Block copolymer of polymethyl methacrylate (PMMA)-poly n-butyl acrylate (PnBA)-polymethyl methacrylate (PMMA), PMMA ratio: 20% by mass Stress relaxation agent 5... Block copolymer of polymethyl methacrylate (PMMA)-poly n-butyl acrylate (PnBA)-polymethyl methacrylate (PMMA), PMMA ratio: 30% by mass Stress relaxation agent 6... Block copolymer of polymethyl methacrylate (PMMA)-poly n-butyl acrylate (PnBA)-polymethyl methacrylate (PMMA), PMMA ratio: 40% by mass Stress relaxation agent 7...block copolymer of polymethyl methacrylate (PMMA)-poly n-butyl acrylate (PnBA)-polymethyl methacrylate (PMMA), PMMA ratio: 50% by mass

[0072] Inorganic filler 1...fine particle silica with an average particle size of 0.5 μm, product name "SE2500-SQV", Admatechs Co., Ltd. Inorganic filler 2...spherical silica with an average particle size of 10 μm, product name "STW7010-20", Nippon Steel Chemical & Material Co., Ltd. Inorganic filler 3...fine particle silica with an average particle size of 0.5 μm, product name "SC2500-SQ", Admatechs Co., Ltd. Inorganic filler 4...spherical fused silica with an average particle size of 11 μm, product name "ST7010-2", Micron Co., Ltd. Inorganic filler 5...spherical fused silica with an average particle size of 8 μm, product name "NQ5085H", Novoray Corporation

[0073] (Spiral flow) The spiral flow was measured by molding the encapsulating resin composition using a spiral flow measurement mold conforming to EMMI-1-66 under the conditions of a mold temperature of 175°C, a molding pressure of 7 MPa, and a curing time of 150 seconds, and determining the flow distance (cm). The results are shown in Table 2.

[0074] (Measurement of Gel Time) The gel time (seconds) was determined by measuring the time from when 0.7 g of the encapsulating resin composition was placed on a hot plate preheated to 175° C. to when the resin lost its viscosity. The results are shown in Table 2.

[0075] (Measurement of linear expansion coefficient) The encapsulating resin composition was molded using a transfer molding machine under conditions of a mold temperature of 175°C, a molding pressure of 7 MPa, and a curing time of 150 seconds, and then post-cured at 175°C for 5 hours to produce a cured product. The cured product had a rectangular shape with a short side of 5 mm, a long side of 20 mm, and a thickness of 4 mm. The linear expansion coefficient α1 (×10) between 40°C and 80°C was measured using a thermomechanical analyzer (for example, TMA / SS6100 manufactured by Seiko Instruments Inc.). －５ / °C) and the linear expansion coefficient α2 (×10 －５ The test load was 98 mN and the temperature rise rate was 5°C / min. The results are shown in Table 2.

[0076] (Glass Transition Temperature) The glass transition temperature (°C) of the cured product was determined as the temperature at the intersection of the tangent line at 60°C and the tangent line at 280°C obtained by measuring the linear expansion coefficient. The results are shown in Table 2.

[0077] (Flexural modulus) Using the encapsulating resin composition, a plate-shaped cured product (length 80 mm, width 10 mm, thickness 4 mm) was obtained under the same conditions as for measuring the thermal expansion coefficient. The flexural modulus values ​​of the cured product at room temperature (25 ° C) and high temperature (260 ° C) were calculated by three-point bending measurement based on JIS K7171 (2016). The results are shown in Table 2.

[0078] (Viscosity) The viscosity of the encapsulating resin composition at 140°C was measured using a rotational rheometer manufactured by NETZSCH. －１ The viscosity (Pa·s) measured at this temperature is shown in Table 2.

[0079] (Evaluation of Warpage Amount) A layer of the encapsulating resin composition was formed to a thickness of 400 μm on a silicon wafer having a thickness of 750 μm and a diameter of 300 mm, and the layer was heated at 130° C. for 10 minutes to cure the layer, thereby preparing a sample. The cured product was cured at 150° C. for 1 hour to obtain an encapsulant sample with a silicon wafer. The amount of warpage (mm) was evaluated by holding a ruler over the sample. The maximum amount of warpage is shown in Table 2.

[0080] (Appearance Evaluation) The appearance of the cured product was evaluated by the following method. A layer of the encapsulating resin composition was formed on a silicon wafer with a thickness of 750 μm and a diameter of 300 mm, and the layer was heated at 130° C. for 10 minutes to cure the composition, thereby preparing a sample. The prepared cured product was cured at 150° C. for 1 hour to obtain an encapsulant sample with a silicon wafer. The evaluation criteria for the appearance of the cured product were as follows: A: No abnormalities B: Abnormalities such as white spots or flow marks present on the front surface The results are shown in Table 2.

[0081] (PI Wettability) PI wettability was evaluated using the following method. A layer of the encapsulating resin composition was formed on a silicon wafer with a thickness of 750 μm and a diameter of 300 mm, and then heated at 130° C. for 10 minutes to cure the layer, producing a sample. The cured product was cured at 150° C. for 1 hour to obtain an encapsulant sample with a silicon wafer. Subsequently, PI (polyimide) was applied using a spin coater, and the presence or absence of PI repulsion was confirmed. A: No repulsion. B: Repulsion. The results are shown in Table 2.

[0082]

[0083]

[0084] As shown in Table 2, the amount of warpage was suppressed compared to the comparative examples in Examples 1 to 8. Furthermore, in the examples in which an appearance evaluation was performed, the evaluation results of the appearance were also good.

[0085] The disclosure of Japanese Patent Application No. 2024-094649, filed on June 11, 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. An encapsulating resin composition comprising a curable resin component, a (meth)acrylic copolymer, and a filler, wherein the (meth)acrylic copolymer comprises a first polymer chain comprising a structural unit derived from methyl methacrylate and a second polymer chain comprising a structural unit derived from n-butyl acrylate.

2. The encapsulating resin composition according to claim 1, wherein the mass ratio of the first polymer chains to the second polymer chains, that is, the first polymer chains:second polymer chains, is 1:9 to 5:

5.

3. The encapsulating resin composition according to claim 1, wherein the curable resin component contains an epoxy resin, and the content of the (meth)acrylic copolymer is 30 mass % or less based on the total amount of the epoxy resin.

4. The encapsulating resin composition according to claim 1, wherein the curable resin component comprises an epoxy resin, and the epoxy resin comprises a biphenyl-type epoxy resin.

5. The encapsulating resin composition according to claim 1, wherein the curable resin component contains a curing agent, and the curing agent contains a triphenylmethane type phenolic resin.

6. The encapsulating resin composition according to claim 1, wherein the content of the filler is 30% by volume to 90% by volume.

7. The encapsulating resin composition according to any one of claims 1 to 6, which is used for wafer-level packaging.

8. The encapsulating resin composition according to any one of claims 1 to 6, which is used in FO-WLP.

9. The encapsulating resin composition according to any one of claims 1 to 6, which is used for encapsulation by compression molding.

10. The encapsulating resin composition according to any one of claims 1 to 6, which is in powder form.

11. A rearrangement wafer comprising a support, a plurality of semiconductor chips arranged on the support, and a cured product of the encapsulating resin composition according to any one of claims 1 to 6, encapsulating the semiconductor chips.

12. A semiconductor package comprising a support, a semiconductor chip placed on the support, and a cured product of the encapsulating resin composition according to any one of claims 1 to 6, encapsulating the semiconductor chip.

13. A method for manufacturing a semiconductor package, comprising the steps of: arranging a plurality of semiconductor chips on a support; arranging the encapsulating resin composition according to any one of claims 1 to 6 on the support on which the semiconductor chips are arranged; curing the encapsulating resin composition arranged on the support to encapsulate the semiconductor chips; and singulating the semiconductor chips.

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