JP2017128657A - Sealing epoxy resin composition, and semiconductor device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing epoxy resin composition capable of forming a cured product which has a large thermal shrinkage from a molding temperature to a room temperature, and has high elasticity modulus in a reflow process.SOLUTION: There is provided a sealing epoxy resin composition which contains (A) an epoxy resin, (B) a phenol novolak resin that has a structure represented by formula (i) and has an allyl group, and (C) an inorganic filler, where it is desirable that the allyl group of the phenol novolak resin having the allyl group is in an ortho position, and a content of the resin is 3-15 wt.%. In formula (i), n is an integer of 0 or more.SELECTED DRAWING: None

Description

  The present disclosure relates to an epoxy resin composition for sealing, a semiconductor device, and a manufacturing method thereof.

  In recent years, the demand for high-density packaging due to the miniaturization and thinning of electronic devices has increased rapidly. For this reason, the surface mount type suitable for high-density mounting is the mainstream of the semiconductor package instead of the conventional pin insertion type. This surface mount type semiconductor package is manufactured by soldering leads directly to a printed circuit board or the like. As a heating method, there are infrared reflow, vapor phase reflow, solder dipping, and the like, and the semiconductor element is mounted on a printed circuit board or the like by heating the whole package by any one of the heating methods.

  After surface mounting, underfill material is filled into the space between the semiconductor element and the substrate in order to protect the surface of the semiconductor element and ensure the connection reliability between the semiconductor element and the substrate. .

  In a single-sided resin-encapsulated package filled with an underfill material, the shape of the single-sided resin-encapsulated package is single-sided, so there is a difference in coefficient of linear expansion and a difference in elastic modulus between the sealing resin and package components such as a substrate. Warpage occurs due to the thermal stress generated. As a result, phenomena such as transportability problems and a decrease in mounting reliability during the reflow process occur.

  In order to suppress such a phenomenon, it is desired to reduce the thermal stress generated due to the difference in linear expansion coefficient between the sealing resin and the package component such as the substrate and the difference in elastic modulus. For example, Patent Document 1 proposes to alleviate the difference in the thermal response behavior among the three elements of a semiconductor element, a cured product of a thermosetting resin composition, and an adherend for improving reliability.

JP 2014-210880 A

  In recent semiconductor packages, packages with a thin sealing resin layer are increasing. To reduce the size and thickness of a semiconductor device, the thickness of the semiconductor element may be reduced. However, as the semiconductor element becomes thinner, the influence of thermal response behavior (warping and expansion, etc.) on the semiconductor element increases. . This is because the coefficient of thermal expansion of the substrate or the like is generally larger than the value of the semiconductor element. In particular, stresses due to differences in the thermal response behavior of the semiconductor element and the substrate tend to concentrate on the connection member such as a solder bump that connects the semiconductor element and the substrate, and in some cases, the joint may be broken.

  In a package configuration in which a sealing resin layer is formed on the upper side of a semiconductor element, warping occurs at room temperature (hereinafter referred to as “cry warping”), and warping downward at reflow temperature (hereinafter referred to as “smile warping”). ") Occurs. In order to suppress such a phenomenon, the cry warpage due to the substrate is increased by increasing the elastic modulus at the reflow temperature while maintaining a large thermal contraction rate (linear expansion coefficient: CTE1) of the sealing resin from the molding temperature to room temperature. It is conceivable to suppress this.

  The present invention provides an epoxy resin composition for sealing capable of forming a cured product having a large thermal contraction rate (linear expansion coefficient: CTE1) from a molding temperature to room temperature and having a high elastic modulus during a reflow process. The purpose is to do. Another object of the present invention is to provide a semiconductor device in which the occurrence of warpage is suppressed by using the sealing epoxy resin composition, and a method for manufacturing such a semiconductor device.

  In one aspect, the present invention provides an epoxy resin composition for sealing containing (A) an epoxy resin, (B) a phenol novolac resin having an allyl group, and (C) an inorganic filler. This sealing epoxy resin composition can form a cured product having a high thermal contraction rate (linear expansion coefficient: CTE1) from the molding temperature to room temperature and a high elastic modulus during the reflow process. Thereby, the difference in thermal response behavior between the semiconductor element and the substrate can be alleviated when used in the manufacture of a semiconductor device. Therefore, when a semiconductor device is manufactured by integrally molding a semiconductor element, a metal such as a bump, and a substrate, warping can be sufficiently suppressed. As a result, the reliability of the package during the reflow process can be improved.

(B) The phenol novolac resin having an allyl group preferably has a structure represented by the following general formula (i).

  In the general formula (i), n represents an integer of 0 or more.

  (B) The allyl group of the phenol novolak resin having an allyl group is preferably in the ortho position. (B) It is preferable that content of the phenol novolak resin which has an allyl group is 3-15 mass%. (C) The inorganic filler preferably contains silica.

  In another aspect, the present invention provides a semiconductor device including an element sealed with a cured product of the above-described sealing epoxy resin composition. A cured product of the epoxy resin composition for sealing in this semiconductor device has a large thermal contraction rate (linear expansion coefficient: CTE1) from the molding temperature to room temperature, and has a high elastic modulus during the reflow process. For this reason, generation | occurrence | production of curvature is fully reduced. Examples of the element include a semiconductor element.

  In still another aspect, the present invention provides a method for manufacturing a semiconductor device, which includes a step of sealing using the above-described sealing epoxy resin composition. The cured product of the epoxy resin composition for sealing has a large thermal contraction rate (linear expansion coefficient: CTE1) from the molding temperature to room temperature, and has a high elastic modulus during the reflow process. For this reason, it is possible to manufacture a semiconductor device in which the occurrence of warpage is sufficiently reduced.

  According to the present invention, an epoxy resin composition for sealing capable of forming a cured product having a large thermal contraction rate (linear expansion coefficient: CTE1) from a molding temperature to room temperature and having a high elastic modulus during a reflow process. Is provided. Moreover, by using the epoxy resin composition for sealing, a semiconductor device in which the occurrence of warpage is suppressed and a method for manufacturing such a semiconductor device are provided.

  Embodiments of the present invention will be described below. However, the following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents.

  In the present specification, a numerical range indicated using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively. Further, when referring to the amount of each component in the composition in the present specification, when there are a plurality of substances corresponding to each component in the composition, the plurality of the components present in the composition unless otherwise specified. It means the total amount of substance.

<Epoxy resin composition for sealing>
The epoxy resin composition for sealing of this embodiment contains (A) an epoxy resin, (B) a phenol novolac resin having an allyl group, and (C) an inorganic filler. The epoxy resin composition for sealing may be in a powder form. (B) The phenol novolac resin having an allyl group has a higher viscosity than the general phenol novolac resin, while the softening point is low.

  The epoxy resin composition for sealing of this embodiment is solid at normal temperature and normal pressure. There is no restriction | limiting in the shape, What kind of shapes, such as a powder form, a granular form, or a tablet form, may be sufficient. The epoxy resin composition for sealing of this embodiment has a high filling property required as an underfill material when used for flip chip mounting. Therefore, since the molding defects such as voids can be reduced, its industrial value is great. The sealing epoxy resin composition of this embodiment is suitable for sealing a flip chip mounting type semiconductor device having fine pitch bumps and a large number of inputs / outputs (number of bumps).

  In this specification, normal temperature is 20 ° C. and normal pressure is atmospheric pressure. Below, each component contained in the epoxy resin composition for sealing is demonstrated in detail.

<(A) Epoxy resin>
(A) As an epoxy resin, there is no restriction | limiting in particular by what is generally used for the epoxy resin composition for sealing. For example, phenol, cresol, xylenol, resorcin, catechol, including biphenyl type epoxy resin, phenol novolak type epoxy resin, orthocresol novolak type epoxy resin, epoxy resin having triphenylmethane skeleton (triphenylmethane type epoxy resin), Acid catalysts for phenols such as bisphenol A and bisphenol F, naphthols such as α-naphthol, β-naphthol, and dihydroxynaphthalene, and compounds having an aldehyde group such as formaldehyde, acetaldehyde, propionaldehyde, benzaldehyde, and salicylaldehyde Examples thereof include epoxidized novolak resins obtained by condensation or cocondensation below.

  Also, by reaction of epichlorohydrin with bisphenol A, bisphenol F, bisphenol S, diglycidyl ether such as alkyl-substituted or unsubstituted biphenol, or polybasic acid such as stilbene type epoxy resin, hydroquinone type epoxy resin, phthalic acid, dimer acid The resulting glycidyl ester type epoxy resin, diaminodiphenylmethane, isocyanuric acid, and other polyamines and epoxidized glycidylamine type epoxy resin, dicyclopentadiene and phenol co-condensation resin (dicyclopentadiene type epoxy resin) Of aralkyl type phenol resins such as epoxy resin having naphthalene ring (naphthalene type epoxy resin), phenol aralkyl resin, naphthol aralkyl resin, etc. Poxy compounds, trimethylolpropane type epoxy resins, terpene modified epoxy resins, linear aliphatic epoxy resins obtained by oxidizing olefinic bonds with peracids such as peracetic acid, alicyclic epoxy resins, sulfur atom-containing epoxy resins It is done.

  One of these may be included alone, or two or more may be included in combination. Among these epoxy resins, from the viewpoint of reliability and moldability, it is preferable to include a biphenyl type epoxy resin or a low moisture absorption type epoxy resin in which a lower alkyl group is added to a phenyl ring. As such an epoxy resin, for example, those having an epoxy equivalent of 150 to 250 g / eq and a softening point or melting point of 50 to 130 ° C. are suitable.

  From the viewpoints of filling properties and reflow resistance, biphenyl type epoxy resins, bisphenol F type epoxy resins, stilbene type epoxy resins and sulfur atom-containing epoxy resins are preferable, and it is more preferable to increase the ratio of bisphenol F type epoxy resins. From the viewpoint of curability, a novolac type epoxy resin is preferable. From the viewpoint of low hygroscopicity, a dicyclopentadiene type epoxy resin is preferable. From the viewpoint of heat resistance and low warpage, naphthalene type epoxy resin and triphenylmethane are preferable. Type epoxy resins are preferred, and preferably contain at least one of these epoxy resins.

  Examples of the biphenyl type epoxy resin include an epoxy resin represented by the following general formula (I). Examples of the bisphenol F type epoxy resin include an epoxy resin represented by the following general formula (II). As a stilbene type epoxy resin, the epoxy resin shown, for example by the following general formula (III) is mentioned. As a sulfur atom containing epoxy resin, the epoxy resin shown, for example by the following general formula (IV) is mentioned.

In general formula (I), R ^{1 to} R ⁸ represent a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. Each of the plurality of R ^{1 to} R ⁸ may be the same or different. n represents an integer of 0 to 3.

In general formula (II), R ^{1 to} R ⁸ are a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted carbon. An allyl group having 6 to 10 carbon atoms or a substituted or unsubstituted aralkyl group having 6 to 10 carbon atoms is shown. Each of the plurality of R ^{1 to} R ⁸ may be the same or different. n represents an integer of 0 to 3.

In general formula (III), R ^{1 to} R ⁸ represent a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 5 carbon atoms. Each of the plurality of R ^{1 to} R ⁸ may be the same or different. n represents an integer of 0 to 10.

In general formula (IV), R ^{1 to} R ⁸ represent a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms. Each of the plurality of R ^{1 to} R ⁸ may be the same or different. n represents an integer of 0 to 3.

  Examples of the substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms include a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms and a substituted or unsubstituted allyl group having 6 to 10 carbon atoms. It is done.

  Examples of the substituted or unsubstituted alkyl group having 1 to 10 carbon atoms include methyl group, ethyl group, propyl group, butyl group, isopropyl group, and isobutyl group. Examples of the substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.

  Examples of the biphenyl type epoxy resin represented by the general formula (I) include 4,4′-bis (2,3-epoxypropoxy) biphenyl or 4,4′-bis (2,3-epoxypropoxy) -3. , 3 ′, 5,5′-tetramethylbiphenyl as the main component, and epichlorohydrin and 4,4′-biphenol or 4,4 ′-(3,3 ′, 5,5′-tetramethyl) The epoxy resin obtained by making biphenol react is mentioned. Among these, an epoxy resin containing 4,4'-bis (2,3-epoxypropoxy) -3,3 ', 5,5'-tetramethylbiphenyl as a main component is preferable.

As the bisphenol F type epoxy resin represented by the general formula (II), for example, R ¹ , R ³ , R ⁶ and R ⁸ are methyl groups, and R ² , R ⁴ , R ⁵ and R ⁷ are hydrogen atoms. Yes, a trade name YSLV-80XY (manufactured by Nippon Steel Chemical Co., Ltd.) whose main component is n = 0 is available as a commercial product.

  The stilbene type epoxy resin represented by the above general formula (III) can be obtained by reacting a raw material stilbene phenol and epichlorohydrin in the presence of a basic substance. Examples of the raw material stilbene phenols include 3-t-butyl-4,4′-dihydroxy-3 ′, 5,5′-trimethylstilbene, 3-t-butyl-4,4′-dihydroxy-3. ', 5', 6-trimethylstilbene, 4,4'-dihydroxy-3,3 ', 5,5'-tetramethylstilbene, 4,4'-dihydroxy-3,3'-di-t-butyl-5 , 5′-dimethylstilbene, 4,4′-dihydroxy-3,3′-di-t-butyl-6,6′-dimethylstilbene. Of these, 3-t-butyl-4,4′-dihydroxy-3 ′, 5,5′-trimethylstilbene and 4,4′-dihydroxy-3,3 ′, 5,5′-tetramethylstilbene are preferred. . These stilbene type phenols may contain 1 type independently, and may contain 2 or more types in combination.

Among the sulfur atom-containing epoxy resins represented by the general formula (IV), R ² , R ³ , R ⁶ and R ⁷ are hydrogen atoms, and R ¹ , R ⁴ , R ⁵ and R ⁸ are alkyl groups. Epoxy resins are preferred, and R ² , R ³ , R ⁶ and R ⁷ are hydrogen atoms, R ¹ and R ⁸ are t-butyl groups, and R ⁴ and R ⁵ are methyl groups. As such a compound, a trade name YSLV-120TE (manufactured by Nippon Steel Chemical Co., Ltd.) and the like are available as commercial products.

  The epoxy resins represented by the general formulas (I) to (IV) may include any one of them alone or in combination of two or more. The content is preferably 40% by mass or more, more preferably 60% by mass or more, and more preferably 80% by mass or more, based on the total amount of the epoxy resin in order to exhibit its performance. preferable.

  As a novolak-type epoxy resin, the epoxy resin shown by the following general formula (V) is mentioned, for example.

  In the general formula (V), a plurality of R's each independently represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. n represents an integer of 0 to 10.

  The novolak type epoxy resin represented by the general formula (V) can be easily obtained by reacting a novolak type phenol resin with epichlorohydrin. Especially, as R in general formula (V), it is a C1-C10 alkyl group, such as a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, an isobutyl group, a methoxy group, and an ethoxy group. C1-C10 alkoxy groups, such as a propoxy group and a butoxy group, are preferable, and a hydrogen atom or a methyl group is more preferable. n is preferably an integer of 0 to 3. Among the novolak epoxy resins represented by the general formula (V), orthocresol novolac epoxy resins are preferable.

  When using a novolak type epoxy resin, the content thereof is preferably 20% by mass or more, more preferably 30% by mass or more, based on the total amount of the epoxy resin in order to exhibit its performance.

  Examples of the dicyclopentadiene type epoxy resin include an epoxy resin represented by the following general formula (VI).

In general formula (VI), a plurality of R ^{1 s} each independently represent a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a plurality of R ^{2 s} independently , A substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. n represents an integer of 0 to 10, and m represents an integer of 0 to 6.

R ¹ in the general formula (VI) is, for example, a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, a t-butyl group or other alkyl group, a vinyl group, an allyl group, or a butenyl group. And a substituted or unsubstituted monovalent hydrocarbon group having 1 to 5 carbon atoms such as an alkenyl group, a halogenated alkyl group, an amino group-substituted alkyl group, a mercapto group-substituted alkyl group, and the like. Among these, an alkyl group such as a methyl group or an ethyl group and a hydrogen atom are preferable, and a hydrogen atom and a methyl group are more preferable.

R ² in the above formula (VI) is, for example, an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group or a t-butyl group, an alkenyl group such as a vinyl group, an allyl group or a butenyl group. And substituted or unsubstituted monovalent hydrocarbon groups having 1 to 5 carbon atoms such as a halogenated alkyl group, an amino group-substituted alkyl group, and a mercapto group-substituted alkyl group. Among these, m is preferably 0.

  When a dicyclopentadiene type epoxy resin is used, the content thereof is preferably 20% by mass or more, more preferably 30% by mass or more, based on the total amount of the epoxy resin in order to exhibit its performance.

  As a naphthalene type epoxy resin, the epoxy resin shown, for example by the following general formula (VII) is mentioned. Examples of the triphenylmethane type epoxy resin include an epoxy resin represented by the following general formula (VIII).

In general formula (VII), R ^{1 to} R ³ represent a substituted or unsubstituted monovalent hydrocarbon group having 1 to 12 carbon atoms. Each of the plurality of R ^{1 to} R ⁴ may be the same or different. p is 1 or 0, and l and m each represent an integer of 0 to 11. Here, (l + m) is an integer of 1 to 11, and (l + p) is an integer of 1 to 12. i represents an integer of 0 to 3, j represents an integer of 0 to 2, and k represents an integer of 0 to 4.

  The naphthalene type epoxy resin represented by the general formula (VII) includes a random copolymer containing 1 constituent unit and m constituent units at random, an alternating copolymer containing alternating units, and a copolymer containing regularly. Examples thereof include a block copolymer including a coalescence and a block, and any one of these may be included alone, or two or more may be included in combination.

  In general formula (VIII), a plurality of Rs represent a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and n represents an integer of 1 to 10.

  The epoxy resins represented by the general formulas (VII) and (VIII) may contain any one kind or may contain two or more kinds in combination, but the content exhibits its performance. Therefore, it is preferable that it is 20 mass% or more in total with respect to the epoxy resin whole quantity, It is more preferable that it is 30 mass% or more, It is further more preferable that it is 50 mass% or more.

  The biphenyl type epoxy resin, bisphenol F type epoxy resin, stilbene type epoxy resin, sulfur atom-containing epoxy resin, novolac type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin and triphenylmethane type epoxy resin 1 type may be included independently and 2 or more types may be combined and included.

<(B) Phenol novolac resin having an allyl group>
The (B) allyl group-containing phenol novolak resin (hereinafter also referred to as “(B) allylated phenol novolak resin” for convenience) included in the sealing epoxy resin composition together with the above (A) epoxy resin. The (A) epoxy resin has a function as a curing agent, and refers to all monomers, oligomers, and polymers having two or more phenolic hydroxyl groups in one molecule.

(B) The allylated phenol novolac resin preferably has a structure represented by the following general formula (i).

In the general formula (i), n represents an integer of 0 or more. (B) The hydroxyl equivalent of the allylated phenol novolak resin is, for example, 140 to 200 g / eq, and the softening point is 50 to 130 ° C.

  (B) The allyl group of the allylated phenol novolak resin is preferably in the ortho position. (B) The content of the phenol novolak resin having an allyl group is preferably 3 to 15% by mass with respect to the entire epoxy resin composition for sealing, from the viewpoint of further increasing the flexural modulus. More preferably, it is 10 mass%.

  The curing agent for the (A) epoxy resin may contain (B) an allylated phenol novolac resin alone or (B) in combination with other phenolic resins different from the allylated phenol novolak resin. Also good. The content of the (B) allylated phenol novolak resin with respect to the total amount of the curing agent is preferably 30% by mass or more, and more preferably 40% by mass or more.

  Examples of other phenol resins include phenols such as phenol, cresol, resorcin, catechol, bisphenol A, bisphenol F, phenylphenol, and aminophenol, and / or naphthols such as α-naphthol, β-naphthol, dihydroxynaphthalene, and formaldehyde From novolak-type phenol resins, phenols and / or naphthols and dimethoxyparaxylene or bis (methoxymethyl) biphenyl obtained by condensation or cocondensation with a compound having an aldehyde group such as benzaldehyde and salicylaldehyde under an acidic catalyst Synthesized phenol / aralkyl resins, aralkyl-type phenol resins such as naphthol / aralkyl resins, phenols and / or naphthols and cyclopentadiene Examples thereof include dicopentadiene type phenolic resins such as dichloropentadiene type phenol novolak resin and naphthol novolak resin, and terpene-modified phenolic resins synthesized by combination.

  Furthermore, (B) the phenol novolac resin contained together with the allylated phenol novolak resin is preferably a biphenyl type phenol resin from the viewpoint of flame retardancy, and an aralkyl type phenol resin is preferable from the viewpoint of reflow resistance and curability. From the viewpoint of low hygroscopicity, dicyclopentadiene type phenol resin is preferable. From the viewpoint of heat resistance, low expansion coefficient and low warpage, triphenylmethane type phenol resin is preferable, and from the viewpoint of curability, novolak. Type phenolic resin is preferred. From the viewpoint of improving any of the above properties, it is preferable to contain at least one of these phenol resins.

  As a biphenyl type phenol resin, the phenol resin shown by the following general formula (IX) is mentioned, for example.

In general formula (IX), R ^{1 to} R ⁹ are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, and a substituted group. Alternatively, it represents an unsubstituted allyl group having 6 to 10 carbon atoms, or a substituted or unsubstituted aralkyl group having 6 to 10 carbon atoms. Each of the plurality of R ^{1 to} R ⁹ may be the same or different. n represents an integer of 0 to 3.

R ^{1 to} R ⁹ in the general formula (IX) are preferably each independently of 1 to 10 carbon atoms such as a hydrogen atom, a methyl group, an ethyl group, a propyl group, a butyl group, an isopropyl group, and an isobutyl group. Alkyl groups having 1 to 10 carbon atoms such as alkyl groups, methoxy groups, ethoxy groups, propoxy groups, and butoxy groups, allyl groups having 6 to 10 carbon atoms such as phenyl groups, tolyl groups, and xylyl groups, and benzyl groups and phenethyl groups. It is selected from an aralkyl group having 6 to 10 carbon atoms such as a group, and more preferably selected from a hydrogen atom and a methyl group.

Examples of the biphenyl type phenol resin represented by the general formula (IX) include compounds in which R ^{1 to} R ⁹ are all hydrogen atoms. Among these, from the viewpoint of melt viscosity, a mixture of condensates containing 50% by mass or more of a condensate having n of 1 or more is preferable. As such a compound, a trade name MEH-7851 (manufactured by Meiwa Kasei Co., Ltd.) is commercially available.

  When a biphenyl type phenol resin is used, its content is preferably 30% by mass or more, more preferably 50% by mass or more, and more preferably 80% by mass with respect to the total amount of the curing agent in order to exhibit its performance. % Or more is more preferable.

  Examples of the aralkyl type phenol resin include a phenol aralkyl resin and a naphthol aralkyl resin. Among these, a phenol / aralkyl resin represented by the following general formula (X) is preferable, and a phenol / aralkyl resin in which R in the general formula (X) is a hydrogen atom and the average value of n is 0 to 8 is more preferable. preferable. Specific examples include p-xylylene type phenol / aralkyl resins and m-xylylene type phenol / aralkyl resins. When using these aralkyl type phenol resins, the content thereof is preferably 30 to 70% by mass, more preferably 50 to 60% by mass with respect to the total amount of the curing agent in order to exhibit its performance. .

  In general formula (X), R represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and n represents an integer of 0 to 10.

  Examples of the dicyclopentadiene type phenol resin include a phenol resin represented by the following general formula (XI).

In general formula (XI), a plurality of R ^{1 s} each independently represent a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and a plurality of R ^{2 s} independently A substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms is shown. n represents an integer of 0 to 10, and m represents an integer of 0 to 6.

  When the dicyclopentadiene type phenol resin is contained, the content thereof is preferably 30 to 70% by mass and more preferably 50 to 60% by mass or more based on the total amount of the curing agent in order to exhibit the performance. Is more preferable.

  As a triphenylmethane type phenol resin, the phenol resin shown by the following general formula (XII) is mentioned, for example.

  In general formula (XII), a plurality of R's each independently represents a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, and n represents an integer of 1 to 10.

  When the triphenylmethane type phenol resin is contained, the content thereof is preferably 30 to 70% by mass and 50 to 60% by mass with respect to the total amount of the curing agent in order to exhibit the performance. More preferred.

  Examples of novolak type phenol resins include phenol novolak resins, cresol novolak resins, and naphthol novolak resins. Of these, phenol novolac resins are preferred. (B) When containing a novolak-type phenol resin different from the allylated phenol novolak resin, the content is preferably 30 to 70% by mass with respect to the total amount of the curing agent in order to exhibit its performance, 50 More preferably, it is -60 mass%.

  The biphenyl type phenol resin, the aralkyl type phenol resin, the dicyclopentadiene type phenol resin, the triphenylmethane type phenol resin and the novolac type phenol resin may contain any one kind alone, or two or more kinds. It may be included in combination. The content of the phenol resin is preferably 60% by mass or more, and more preferably 80% by mass or more, based on the total amount of the curing agent.

  (B) The melt viscosity at 150 ° C. of the allylated phenol novolak resin is preferably 2 poises or less, more preferably 1 poise or less from the viewpoint of filling properties. Here, the melt viscosity is a viscosity measured with an ICI cone plate viscometer.

  (A) Equivalent ratio of epoxy resin and (B) allylated phenol novolak resin, that is, ratio of number of hydroxyl groups in allylated phenol novolak resin to number of epoxy groups in epoxy resin (number of hydroxyl groups in allylated phenol novolak resin / The number of epoxy groups in the epoxy resin is not particularly limited, but is preferably 0.5 to 2 and more preferably 0.6 to 1.3 in order to suppress each unreacted component. In order to obtain a sealing epoxy resin composition excellent in moldability and reflow resistance, it is more preferably 0.8 to 1.2.

<(C) Inorganic filler>
Examples of the inorganic filler (C) contained in the sealing epoxy resin composition together with the (A) epoxy resin and (B) allylated phenol novolak resin include silica powder and alumina powder. Examples of the silica powder include fused silica powder and crystalline silica powder. These inorganic fillers may contain 1 type independently, and may contain it in combination of 2 or more types. Among the silica powders, the inclusion of fused silica powder is particularly preferable from the viewpoints of high filling properties and high fluidity. Examples of the fused silica powder include spherical fused silica powder and crushed fused silica powder. From the viewpoint of fluidity, the fused silica powder preferably contains spherical fused silica powder. Moreover, when heat conductivity is requested | required, it is preferable to contain an alumina powder.

  (C) It is preferable that the inorganic filler has an average particle diameter of 1 to 100 μm from the viewpoint of improving fluidity. Furthermore, (C) the inorganic filler preferably has a particle size distribution in which the average particle size is 3 to 30 μm, and the particles having a particle size of 2 μm or less are 5 to 40% by mass of the entire inorganic filler. Thereby, the narrow gap filling property of the excellent mold underfill can be exhibited.

  The average particle size and particle size distribution of (C) inorganic filler in the present specification are obtained by collecting inorganic filler (fused spherical silica, etc.) according to JIS M 8100: 1992 (powder mixture-general rule of sampling method). An inorganic filler was prepared as a measurement sample in accordance with R 1622: 1995 (general rules for sample preparation for fine ceramic raw material particle size distribution measurement), and JIS R 1629: 1997 (particles of fine ceramic raw material by laser diffraction / scattering method). In accordance with the diameter distribution measuring method), a laser diffraction particle size distribution measuring device SALD-7000 (laser wavelength: 405 nm) manufactured by Shimadzu Corporation is used, water is used as a solvent, and the refractive index of the inorganic filler is a real part. Under the condition of 45 and imaginary part 0.00, the particle diameter standard is measured as the volume standard.

  (C) When the average particle diameter of the inorganic filler exceeds 30 μm, the filling property tends to be lowered. Moreover, when the average particle diameter of the (C) inorganic filler is less than 3 μm, the melt viscosity tends to increase and a wire flow tends to occur. Furthermore, (C) In the particle size distribution of the inorganic filler, if the particles having a particle size of 2 μm or less are less than 5% by mass, the underfill filling property is lowered, and if the particles having a particle size of 2 μm or less exceed 40% by mass, the particles are melted Viscosity tends to increase.

  (C) It is preferable that content of an inorganic filler is 60-92 mass% of the whole epoxy resin composition, and it is more preferable that it is 75-85 mass%. (C) It is preferable that the volume fraction of an inorganic filler is 60 to 85 volume%, and it is preferable that it is 65 to 80 volume%. That is, if the content of (C) the inorganic filler is too small, the effect of reducing the water absorption rate by the inorganic filler is reduced, and the absolute value of the water absorption rate of the epoxy resin composition itself is increased in the first place. The humidity reliability tends to decrease. Conversely, when there is too much content of an inorganic filler (C), the fluidity | liquidity of an epoxy resin composition will fall, and it exists in the tendency for a wire flow and unfilling to generate | occur | produce.

  The epoxy resin composition for sealing (epoxy resin composition for semiconductor sealing) of the present embodiment includes a curing accelerator, a coupling agent, a release agent, and carbon black as necessary in addition to the above A to C. Other additives such as pigments may be included as optional components.

  A conventionally well-known thing is used as a hardening accelerator. Specifically, organophosphorus compounds such as tetraphenylphosphonium / tetraphenylborate and triphenylphosphine, imidazole compounds such as phenylimidazole, and 1,8-diazabicyclo (5.4.0) undecene-7, 1, And diazabicycloalkene compounds such as 5-diazabicyclo (4.3.0) nonene-5. These may contain 1 type independently and may contain 2 or more types in combination. It is preferable that the content rate of a hardening accelerator is 0.05-0.5 mass% of the whole epoxy resin composition for sealing.

  As the silane coupling agent, those having two or more alkoxy groups are preferably used. Specifically, 3-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ- ( 2-aminoethyl) aminopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-anilinopropyltrimethoxysilane, and hexamethyldisilazane. These may contain 1 type independently and may contain 2 or more types in combination.

  Examples of the mold release agent include compounds such as higher fatty acids, higher fatty acid esters, and higher fatty acid calcium. Examples thereof include carnauba wax and polyethylene wax. These may contain 1 type independently and may contain 2 or more types in combination.

  Furthermore, for the purpose of improving reliability in the moisture resistance reliability test, hydrotalcites or ion trapping agents such as magnesium hydroxide may be included.

  The sealing epoxy resin composition of this embodiment can be manufactured as follows, for example. That is, (A) an epoxy resin, (B) an allylated phenol novolac resin, (C) an inorganic filler, and if necessary, other additives are appropriately blended according to a conventional method, and a kneader such as a mixing roll machine Is used to melt and knead in a heated state to obtain a kneaded product. Thereafter, the kneaded product is cooled and solidified at room temperature. Then, it grind | pulverizes by a well-known means and it compresses as needed. The target sealing epoxy resin composition can be produced by such a series of steps.

<Semiconductor device>
Next, the semiconductor device of this embodiment will be described. Moreover, the suitable use and usage method of the epoxy resin composition for sealing of this embodiment are demonstrated through description of this semiconductor device.

  The semiconductor device of this embodiment is a semiconductor device provided with the element sealed with the hardened | cured material of the above-mentioned epoxy resin composition for sealing. A semiconductor device is, for example, a support member such as a lead frame, a wired tape carrier, a wiring board, glass, or a silicon wafer, an element mounted on the support member, and a curing of an epoxy resin composition that seals the element. A thing.

  Examples of the element include active elements such as a semiconductor chip, a transistor, a diode, and a thyristor, and passive elements such as a capacitor, a resistor, and a coil. A semiconductor device is manufactured through a process in which such an element is sealed with the epoxy resin composition according to the embodiment.

  Specific examples of the semiconductor device include a TCP (Tape Carrier Package) in which a semiconductor chip is sealed with the epoxy resin composition according to the above embodiment; wire bonding, flip chip bonding, wiring formed on a wiring board or glass; COB (in which an active element such as a semiconductor chip, transistor, diode, or thyristor connected by solder or the like and / or a passive element such as a capacitor, resistor, or coil is sealed with the epoxy resin composition according to the above-described embodiment) Chip On Board) module; hybrid IC; multi-chip module; devices are mounted on the surface of an organic substrate on which wiring board connection terminals are formed on the back surface, and the devices and wiring formed on the organic substrate are connected by bump or wire bonding After the above embodiment That the epoxy resin composition sealing the element with sealed and BGA (Ball Grid Array), and the like CSP (Chip Size Package). In addition, the epoxy resin composition according to the above embodiment can also be used effectively in a printed circuit board.

  The contents of the present invention will be described in more detail using examples and comparative examples, but the present invention is not limited to the following examples.

(Examples 1-4, Comparative Examples 1-2)
<Preparation of epoxy resin composition for sealing>
(A) Epoxy resin The following was used as an epoxy resin.
Epoxy resin 1: o-cresol novolac type epoxy resin, manufactured by Nippon Kayaku Co., Ltd., trade name: EOCN-1020, epoxy equivalent: 195 g / eq, melting point: 67 ° C.
Epoxy resin 2: Epoxy resin, Hitachi Chemical Co., Ltd., trade name: PYB-3K2, epoxy equivalent: 192 g / eq, melting point: 106 ° C.
Epoxy resin 3: biphenyl type epoxy resin, manufactured by Japan Epoxy Resin Co., Ltd., trade name: Epicoat YX-4000H, epoxy equivalent: 196 g / eq, melting point: 106 ° C.

(B) Curing agent The following was used as a curing agent.
Curing agent 1: phenol / xylylene resin, manufactured by Meiwa Kasei Co., Ltd., trade name: MEHC-7800SS, hydroxyl equivalent: 170 g / eq, softening point: 65 ° C.
Curing agent 2: phenol resin, manufactured by Hitachi Chemical Co., Ltd., trade name: HPM-J3, hydroxyl equivalent: 120 g / eq, softening point: 90 ° C.
Curing agent 3: phenol novolac resin, manufactured by Meiwa Kasei Co., Ltd., trade name: MEH-5000S, hydroxyl group equivalent: 168 g / eq, softening point: 73 ° C.

(C) Inorganic filler The following was used as the inorganic filler.
Inorganic filler 1: fused silica, average particle size: 17 μm, manufactured by Denki Kagaku Kogyo Co., Ltd., trade name: FB-9454FC
Inorganic filler 2: fused silica, average particle size: 0.7 μm, manufactured by Denki Kagaku Kogyo Co., Ltd., trade name: SFP-30M

(D) Coupling agent The following was used as a coupling agent.
Coupling agent: 3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-403

The following were used as other additives.
Curing accelerator: adduct of tributylphosphine and benzoquinone Colorant: Carbon black (Mitsubishi Chemical Co., Ltd., trade name: MA-600MJ)
Release agent: Hoechst wax (Clariant, trade name: HW-E)
・ Ion trap agent (manufactured by Sakai Chemical Industry Co., Ltd., trade name: HT-P)

Each component was blended in the proportions shown in Table 1 and thoroughly mixed with a mixer, and then melt-kneaded at about 100 ° C. for 2 minutes using a biaxial kneader. After this melt was cooled, the solid material was pulverized into powders to prepare powdery epoxy resin compositions of Examples 1 to 4 and Comparative Examples 1 and 2, respectively. The blending units in Table 1 are parts by mass unless otherwise specified. "-" Indicates unsigned. In Table 1, the filler amount (Vf) indicates the volume fraction (volume%) of the inorganic filler contained in the powdered epoxy resin composition.

  Each evaluation was performed according to the method shown below using the epoxy resin composition of each Example and each comparative example thus obtained.

<Evaluation>
(1) Linear expansion coefficient (α1, α2) and glass transition temperature (Tg)
The epoxy resin compositions of each Example and each Comparative Example were molded and cured using a transfer molding machine to produce a trapezoidal test piece (20 mm × 5 mm lower side 4 mm × 3 mm upper side). Molding and curing were performed under conditions of a molding temperature of 175 ° C. and a molding time of 90 seconds. Post-curing was performed at 175 ° C. for 5 hours.

  Using TMA high-accuracy two-sample thermal analysis (trade name: SS6100, manufactured by Seiko Instruments Inc.), the linear expansion coefficient (α) and glass transition temperature (Tg) of the test piece under the conditions of a load of 10 g and a heating rate of 5 ° C./min. And were measured. The linear expansion coefficient (α) between the two measured temperatures is calculated by the following equation.

α = 1 / (LΔt)
L = length of test piece at room temperature (mm)
l = Elongation (mm)
Δt = measured temperature difference (° C.)

  The linear expansion coefficient α between two measurement temperatures of 80 ° C. and 100 ° C. was α1, and the linear expansion coefficient α between two measurement temperatures of 200 ° C. and 230 ° C. was α2. The glass transition temperature was the temperature at the intersection of both straight lines. These results are shown in Table 2.

(2) Flexural strength and flexural modulus The epoxy resin compositions of the examples and comparative examples were molded and cured under the same conditions as in (1) above, and a rectangular parallelepiped test piece (length × width × height) = 80 mm x 10 mm x 4 mm). The tensile test of this test piece was performed using a universal tensile tester TENSILON under conditions of a load speed of 5 mm / min and a temperature of 260 ° C. And bending strength and a bending elastic modulus were computed by the following formula | equation. These results are shown in Table 2.

бf = (3PLv) / (2Wh ² )
Ef = (Lv ³ m) / (4 Wh ³ )
бf: Bending strength (MN / m ² )
Ef: flexural modulus (GN / m ² )
P: Load when the test piece is broken (N)
Lv: Distance between supporting points (m)
W: Width of test piece (m)
h: Height of test piece (m)
m: gradient of the tangent of the initial straight line portion of the load-deflection curve (N / m)

  Compared with the epoxy resin composition containing the hardening | curing agent 3 (Examples 1-4), the epoxy resin composition (Comparative Examples 1 and 2) which does not contain the hardening | curing agent 3 had a small high temperature bending elastic modulus. The epoxy resin compositions (Examples 1 to 4) containing the curing agent 3 had a high high-temperature bending elastic modulus while maintaining a large α1. Moreover, when the content rate of the hardening | curing agent 3 became large, there existed a tendency for the linear expansion coefficient (alpha) 1 and a high temperature bending elastic modulus to improve.

  Therefore, by using the epoxy resin composition of the present invention, the elastic modulus at the reflow temperature can be increased while increasing the linear expansion coefficient α1 from the molding temperature to room temperature. Therefore, the thermal stress generated due to the difference in coefficient of linear expansion between the sealing resin and the package component such as the substrate, the difference in elastic modulus, and the like can be reduced. For this reason, it is possible to suppress the curvature of a package.

  According to the present disclosure, an epoxy resin composition for sealing capable of forming a cured product having a large thermal contraction rate (linear expansion coefficient: CTE1) from a molding temperature to room temperature and having a high elastic modulus during a reflow process. Is provided. Moreover, by using the epoxy resin composition for sealing, a semiconductor device in which the occurrence of warpage is suppressed and a method for manufacturing such a semiconductor device are provided.

Claims (7)

(A) epoxy resin,
(B) a phenol novolac resin having an allyl group, and (C) an inorganic filler,
An epoxy resin composition for sealing. The epoxy resin composition for sealing according to claim 1, wherein the (B) phenol novolak resin having an allyl group has a structure represented by the following general formula (i).

[In formula (i), n represents an integer of 0 or more. ]   The epoxy resin composition for sealing according to claim 1 or 2, wherein the allyl group of the (B) allyl group-containing phenol novolac resin is in the ortho position.   The epoxy resin composition for sealing according to any one of claims 1 to 3, wherein the content of the (B) phenol novolac resin having an allyl group is 3 to 15% by mass.   The epoxy resin composition for sealing according to any one of claims 1 to 4, wherein the (C) inorganic filler contains silica.   A semiconductor device provided with the element sealed with the hardened | cured material of the epoxy resin composition for sealing as described in any one of Claims 1-5.   The manufacturing method of a semiconductor device which has the process of sealing an element using the epoxy resin composition for sealing as described in any one of Claims 1-5.