JP2018165333A - Epoxy resin composition, cured product and electronic component device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: an epoxy resin composition which has excellent flowability and causes little increase in viscosity over time; a cured product using the same; and an electronic component device including an element encapsulated with the cured product.SOLUTION: The epoxy resin composition comprises (a) an epoxy resin, (b) an acid anhydride based curative, (c) a curing accelerator, and (d) an inorganic filler. The curing accelerator (c) comprises (c-1) a salt comprising a phosphonium cation represented by the general formula (1-p) in the figure, where Rto Reach independently represent a C1-16 linear or branched alkyl group.SELECTED DRAWING: None

Description

  The present invention relates to an epoxy resin composition, a cured product, and an electronic component device.

  In recent years, as represented by the development of portable electronic devices such as smartphones, tablet terminals, and notebook computers, electronic components such as semiconductor elements (transistors such as field effect transistors (FETs) and thyristors (SCRs)) have a high density. With the trend toward higher integration and higher integration, there is a tendency for miniaturization and thinning. With respect to a semiconductor package in which semiconductor elements are combined, as a technique that can be highly integrated while suppressing a mounting area, BGA (Ball Grid Array), CSP (Chip Size Package), TCP (Tape Carrier Package), COB (Chip On Board), Techniques such as COF (Chip On Film) and SiP (System in Package) have been developed.

  Since the semiconductor element generates a large amount of heat, the sealing material for sealing the semiconductor element includes not only workability, electrical characteristics of the cured product, mechanical characteristics, adhesiveness, water resistance and solvent resistance. It is also necessary to have excellent heat resistance, and usually an epoxy resin sealing composition containing a liquid epoxy resin is used.

  Usually, after an element is mounted on a substrate by bare chip, an epoxy resin composition is filled as an underfill material in a gap between the element and the substrate to interpose the reinforcing portion and protect the element. There are various methods for interposing an epoxy resin composition, and in general, a liquid epoxy resin composition is dropped around the element and impregnated (impregnated) into the gap between the element and the substrate by a capillary phenomenon. Is adopted (see, for example, Patent Document 1).

  Moreover, an epoxy resin composition containing an acid anhydride as a curing agent and tetraphenylphosphonium bromide as a curing accelerator is disclosed (for example, see Patent Document 2). This epoxy resin composition has a high curing rate and is excellent in moldability.

  Recently, a new semiconductor package called WLCSP (Wafer Level Chip Size Package) has attracted attention. In WLCSP, all processes from rewiring, resin sealing, and dicing are performed on the wafer, and the size of the diced semiconductor chip becomes the size of the package as it is, which makes the package excellent in miniaturization and weight reduction.

JP 2002-118127 A JP 2003-002951 A

  However, a conventional epoxy resin composition using an acid anhydride curing agent has poor fluidity, and there is a possibility that the gap between the element and the substrate may not be filled well. Furthermore, there is a problem that the viscosity is likely to increase with the passage of time, and the storage stability is not good and the storage stability is poor.

  Further, in WLCSP, when the epoxy resin composition has a high viscosity, there is also a problem that chip shift tends to occur.

  The present invention provides an epoxy resin composition excellent in fluidity and suppressed in viscosity increase over time, a cured product using the same, and an electronic component device including an element sealed with the cured product. Objective.

  For example, the following embodiments are included in the means for solving the above problems.

<1> (a) an epoxy resin, (b) an acid anhydride-based curing agent, (c) a curing accelerator, and (d) an inorganic filler, wherein (c) the curing accelerator is (c-1) The epoxy resin composition containing the salt containing the phosphonium cation represented by general formula (1-p).

(In the general formula (1-p), R ^{1 to} R ⁴ each independently represents a linear or branched alkyl group having 1 to 16 carbon atoms.)
<2> The epoxy resin composition according to <1>, wherein the content of the inorganic filler (d) is 50% by mass to 90% by mass with respect to the total solid content of the epoxy resin composition.
<3> The epoxy resin composition according to <1> or <2>, wherein the average particle diameter of the (d) inorganic filler is 0.1 μm to 50 μm.
<4> The epoxy resin composition according to any one of <1> to <3>, wherein in the general formula (1-p), all of R ^{1 to} R ⁴ are butyl groups.
<5> The (c) curing accelerator is (c-2) an alicyclic polycarboxylic acid represented by the following general formula (2) and an alicyclic polycarboxylic acid represented by the following general formula (3). An epoxy resin composition according to any one of <1> to <4>, which is a salt containing an anion of at least one alicyclic polycarboxylic acid selected from the group consisting of:

(In General Formula (2), R ⁵ represents a methylene group or an ethylene group, and R ^{6 to} R ⁹ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, Or represents a carboxy group.)

(In General Formula (3), R ^{10 to} R ¹³ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a carboxy group.)

<6> The anion of the at least one alicyclic polycarboxylic acid is (a) an alicyclic ring in which R ⁵ is a methylene group and all of R ^{6 to} R ⁹ are hydrogen atoms in the general formula (2). Group (b) a fatty acid in which R ⁵ is a methylene group, any one of R ^{6 to} R ⁹ is a methyl group, and the remaining three are hydrogen atoms The epoxy resin composition according to <5>, comprising an anion of at least one alicyclic polycarboxylic acid selected from the group consisting of cyclic polycarboxylic acids.
<7> The anion of the at least one alicyclic polycarboxylic acid includes (i) an alicyclic polycarboxylic acid in which all of R ^{10 to} R ¹³ are hydrogen atoms in the general formula (3), and ( ii) In general formula (3), at least one kind of fat selected from the group consisting of alicyclic polycarboxylic acids in which any two of R ^{10 to} R ¹³ are carboxy groups and the remaining two are hydrogen atoms The epoxy resin composition according to <5> or <6>, which contains an anion of a cyclic polycarboxylic acid.
<8> The (c) curing accelerator includes bicyclo [2.2.1] heptane-2,3-dicarboxylic acid, methylbicyclo [2.2.1] heptane-2,3-dicarboxylic acid, and 1,2 The epoxy resin composition according to any one of <1> to <4>, which contains an anion of at least one alicyclic polycarboxylic acid selected from the group consisting of 1,4,5-cyclohexanetetracarboxylic acid.
<9> The epoxy resin (a) is bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, naphthalenediol diglycidyl ether, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, hydrogenated The epoxy resin composition according to any one of <1> to <8>, comprising at least one selected from the group consisting of bisphenol A diglycidyl ether and N, N-diglycidyl-4-glycidyloxyaniline.
<10> The (b) acid anhydride curing agent comprises 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride, and 4-methyltetrahydrophthalic anhydride. The epoxy resin composition according to any one of <1> to <9>, including at least one selected from the group.
<11> The equivalent ratio of the acid anhydride group in the (b) acid anhydride curing agent to the epoxy group in the (a) epoxy resin is 0.9 to 1.2 <1> to <10> The epoxy resin composition as described in any one of these.
<12> (a) epoxy resin, (b ′) 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride, and 4-methyltetrahydrophthalic anhydride An acid anhydride curing agent containing at least one selected from the above, and (c ′) a salt of a tetrabutylphosphonium cation and an anion of an alicyclic polycarboxylic acid, and (a) the epoxy group in the epoxy resin (B ′) An epoxy resin composition in which an equivalent ratio of acid anhydride groups in the acid anhydride curing agent is 1.0 to 1.1.

<13> A cured product of the epoxy resin composition according to any one of <1> to <12>.

<14> An electronic component device including an element sealed with the cured product according to <13>.

  According to the present invention, an epoxy resin composition excellent in fluidity and suppressed in viscosity increase with time, a cured product using the same, and an electronic component device including an element sealed using the cured product are provided. be able to.

  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, the components (including element steps and the like) are not essential unless otherwise specified. The same applies to numerical values and ranges thereof, and the present invention is not limited thereto.

In the present disclosure, the numerical ranges indicated using “to” include numerical values described before and after “to” as the minimum value and the maximum value, respectively.
In the numerical ranges described stepwise in the present disclosure, the upper limit value or lower limit value described in one numerical range may be replaced with the upper limit value or lower limit value of the numerical range described in another stepwise manner. . Further, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples.
In the present disclosure, each component may contain a plurality of corresponding substances. When a plurality of substances corresponding to each component are present in the composition, the content of each component means the total content of the plurality of substances present in the composition unless otherwise specified.
In the present disclosure, a plurality of particles corresponding to each component may be included. When a plurality of particles corresponding to each component are present in the composition, the particle diameter of each component means a value for a mixture of the plurality of particles present in the composition unless otherwise specified.
In the present disclosure, regarding the notation of the group in the compound represented by the general formula, when not substituted or unsubstituted, if the above group can further have a substituent, not only the unsubstituted group A group having a substituent is also included. For example, in the general formula, when “R represents an alkyl group”, it means “R represents an unsubstituted alkyl group or an alkyl group having a substituent”. In addition, it does not specifically limit as a substituent, Halogen atoms, such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a hydroxyl group, a phenyl group, a carboxy group etc. are mentioned. In addition, the carbon number in a substituent shall not be included in the carbon number of an alkyl group.

[Epoxy resin composition]
The epoxy resin composition of the present disclosure includes (a) an epoxy resin, (b) an acid anhydride-based curing agent, (c) a curing accelerator, and (d) an inorganic filler, and (c) the curing accelerator includes (C-1) A salt containing a phosphonium cation represented by the following general formula (1-p) is included.

In General Formula (1-p), R ^{1 to} R ⁴ each independently represents a linear or branched alkyl group having 1 to 16 carbon atoms.

  The epoxy resin composition of this indication is excellent in fluidity | liquidity, and the viscosity raise with time is suppressed. Therefore, an epoxy resin composition having a low viscosity, improved temporal stability, and excellent storage stability can be obtained. Thereby, the wide application to a liquid sealing material use is attained.

[(A) Epoxy resin]
The epoxy resin composition of the present disclosure includes (a) an epoxy resin. (A) The type of epoxy resin is not particularly limited as long as it has an epoxy group in the molecule. The (a) epoxy resin is preferably liquid at room temperature (25 ° C.) from the viewpoint of low viscosity and good workability.

  (A) Specific examples of epoxy resins include diglycidyl ether type epoxy resins such as bisphenol A, bisphenol F, bisphenol AD, bisphenol S, and hydrogenated bisphenol A; phenols and aldehydes typified by orthocresol novolac type epoxy resins Epoxidized type of novolak resin; glycidyl ester type epoxy resin obtained by reaction of polybasic acid such as phthalic acid and dimer acid with epichlorohydrin; amine compound such as p-aminophenol, diaminodiphenylmethane, isocyanuric acid And glycidylamine type epoxy resin obtained by the reaction of chloroquine and epichlorohydrin; linear aliphatic epoxy resin and alicyclic epoxy resin obtained by oxidizing olefinic bonds with peracid such as peracetic acid; and the like. These epoxy resins may be used alone or in combination of two or more. (A) As an epoxy resin, diglycidyl ether type epoxy resins such as bisphenol A, bisphenol F, bisphenol AD, bisphenol S, and hydrogenated bisphenol A are preferable from the viewpoint of fluidity. Moreover, a glycidylamine type epoxy resin is preferable from the viewpoints of heat resistance, adhesiveness, and fluidity.

  (A) More specifically, as an epoxy resin, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, naphthalenediol diglycidyl ether, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate And at least one selected from the group consisting of hydrogenated bisphenol A diglycidyl ether and N, N-diglycidyl-4-glycidyloxyaniline.

  (A) The epoxy equivalent (molecular weight / number of epoxy groups) of the epoxy resin is not particularly limited, and is preferably 50 g / eq to 500 g / eq, more preferably 70 g / eq to 300 g / eq, and 80 g / eq. More preferably, it is eq-200 g / eq.

  (A) The epoxy equivalent of the epoxy resin is a value measured by a method according to JIS K 7236: 2009.

  The content of the epoxy resin (a) in the epoxy resin composition is preferably 0.5% by mass to 30% by mass, more preferably 1% by mass to 20% by mass, and 2% by mass to 15%. It is more preferable that it is mass%, and it is especially preferable that it is 3 mass%-10 mass%.

[(B) Acid anhydride curing agent]
The epoxy resin composition of the present disclosure includes (b) an acid anhydride curing agent. The kind of acid anhydride curing agent is not particularly limited, and can be selected according to (a) the kind of epoxy resin, desired characteristics of the epoxy resin composition, and the like.

  (B) Examples of the acid anhydride curing agent include phthalic anhydride, maleic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride, 4-methyltetrahydrophthalic anhydride, 3- Methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, hymic anhydride, methylhymic anhydride, chlorendic anhydride, succinic anhydride, trimellitic anhydride, pyromellitic anhydride, trialkyltetrahydrophthalic anhydride Maleic acid adducts, benzophenone tetracarboxylic dianhydride, hydrogenated methyl nadic acid anhydride, dodecenyl succinic anhydride and the like can be mentioned. These may be used alone or in combination of two or more.

  (B) The acid anhydride curing agent is selected from the group consisting of 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride and 4-methyltetrahydrophthalic anhydride. It is preferable to include at least one selected from the group consisting of 3-methyltetrahydrophthalic anhydride and 4-methyltetrahydrophthalic anhydride.

  (A) Equivalent ratio of (b) acid anhydride group in acid anhydride curing agent to epoxy group in epoxy resin ((b) number of functional groups in acid anhydride curing agent / (a) in epoxy resin The number of functional groups) is preferably set in the range of 0.9 to 1.2 from the viewpoint of suppressing the amount of each unreacted component and sufficiently proceeding with the curing reaction. More preferably, the range is set.

[(C) Curing accelerator]
The epoxy resin composition of the present disclosure includes (c) a curing accelerator. (C) The curing accelerator is a salt containing (c-1) a phosphonium cation represented by the following general formula (1-p). In addition, in the epoxy resin composition containing (c) the curing accelerator, the reason why the viscosity is low and the increase in viscosity over time is suppressed is that the phosphorus atoms forming the alkylphosphonium cation are around (in the composition) (A) epoxy resin, (b) acid anhydride curing agent, (d) inorganic filler, etc.).

In General Formula (1-p), R ^{1 to} R ⁴ each independently represents a linear or branched alkyl group having 1 to 16 carbon atoms.

In general formula (1-p), R ^{1 to} R ⁴ are preferably each independently a linear or branched alkyl group having 1 to 4 carbon atoms, and all of R ^{1 to} R ⁴ are A linear or branched alkyl group having 1 to 4 carbon atoms (that is, the same alkyl group) is more preferable, and a butyl group is still more preferable.

  (C) The curing accelerator is preferably a salt containing (c-1) a phosphonium cation represented by the above general formula (1-p) and a paired anion, and a carboxyl having at least one carboxy group. It is more preferable that the acid is a salt containing a carboxy anion in which at least one hydrogen atom in the carboxy group is removed, and at least one hydrogen atom in the carboxy group in the polycarboxylic acid having two or more carboxy groups (preferably one). It is further preferred that the salt contains a deviated carboxy anion.

  (C) The curing accelerator is (c-1) an alicyclic polycarboxylic acid represented by the following general formula (2) together with the phosphonium cation represented by the general formula (1-p). And a salt containing an anion of at least one alicyclic polycarboxylic acid selected from the group consisting of alicyclic polycarboxylic acids represented by the following general formula (3).

In General Formula (2), R ⁵ represents a methylene group or an ethylene group, and R ^{6 to} R ⁹ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or Represents a carboxy group.

In General Formula (3), R ^{10 to} R ¹³ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a carboxy group.

In general formula (2), R ⁵ is preferably a methylene group.
R ^{6 to} R ⁹ are each independently preferably a hydrogen atom or a methyl group, and all of R ^{6 to} R ⁹ are hydrogen atoms, or any one of R ^{6 to} R ⁹ is methyl. More preferably, the remaining three are hydrogen atoms.

In General Formula (3), R ^{10 to} R ¹³ are each independently preferably a hydrogen atom or a carboxy group, and all of R ^{10 to} R ¹³ are hydrogen atoms, or R ^{10 to} R ¹³ It is more preferred that any two of them are carboxy groups and the remaining two are hydrogen atoms.

  The “anion of the alicyclic polycarboxylic acid” means that one or more (typically one) carboxy group hydrogen atoms of the alicyclic polycarboxylic acid are removed and the monovalent or higher (typically Is a monovalent) carboxy anion.

The anion of at least one alicyclic polycarboxylic acid is (a) an alicyclic polycarboxylic acid in which R ⁵ is a methylene group and all of R ^{6 to} R ⁹ are hydrogen atoms in the general formula (2). (I) In general formula (2), R ⁵ is a methylene group, any one of R ^{6 to} R ⁹ is a methyl group, and the remaining three are hydrogen atoms. It is preferable to contain an anion of at least one alicyclic polycarboxylic acid selected from the group consisting of acids.

The anion of at least one alicyclic polycarboxylic acid is (i) an alicyclic polycarboxylic acid in which all of R ^{10 to} R ¹³ are hydrogen atoms in the general formula (3), and (ii) In general formula (3), at least one alicyclic selected from the group consisting of alicyclic polycarboxylic acids in which any two of R ^{10 to} R ¹³ are carboxy groups and the remaining two are hydrogen atoms. It preferably contains an anion of a polycarboxylic acid.

The anion of at least one alicyclic polycarboxylic acid is bicyclo [2.2.1] heptane-2,3-dicarboxylic acid (in the general formula (2), R ⁵ is a methylene group, and R ^{6 to} R ⁹ are Hydrogen atom), methylbicyclo [2.2.1] heptane-2,3-dicarboxylic acid (in the general formula (2), R ⁵ is a methylene group, and any one of R ^{6 to} R ⁹ is a methyl group) And the remaining three are hydrogen atoms) and 1,2,4,5-cyclohexanetetracarboxylic acid (in the general formula (3), R ¹¹ and R ¹² are carboxy groups, and R ¹⁰ and R ¹³ are hydrogen atoms). It is preferable to contain an anion of at least one alicyclic polycarboxylic acid selected from the above.

  The content of the (c) curing accelerator in the epoxy resin composition is not particularly limited as long as a curing acceleration effect is obtained. The content of the (c) curing accelerator in the epoxy resin composition is preferably 0.1% by mass to 5.0% by mass with respect to the total amount of the (a) epoxy resin, and 0.2% by mass to More preferably, it is 3.0 mass%, and it is still more preferable that it is 1.0 mass%-2.0 mass%. Thereby, there exists a tendency for the curing rate to be sufficient and to obtain a low-viscosity epoxy resin composition.

  In the alicyclic polycarboxylic acid represented by the general formula (2) and the general formula (3), for example, an isomer in which two carboxy groups bonded to adjacent carbon atoms are in cis configuration and adjacent There are isomers in which the two carboxy groups bonded to each carbon atom are in the trans configuration. The cis configuration refers to the case where the two carboxy groups are on the same side with respect to a single bond between the two carbon atoms to which the two carboxy groups are bonded. The trans configuration refers to a case where one of the two carboxy groups is present on a different side from the other with respect to a single bond between two carbon atoms to which the two carboxy groups are bonded. .

In the epoxy resin composition of the present disclosure, the anion may be derived from a cis configuration alicyclic polycarboxylic acid, may be derived from a trans configuration alicyclic polycarboxylic acid, or a mixture of the two. There may be. When the alicyclic polycarboxylic acid used as a raw material is a trans-cis mixture and the number of carboxy groups is two, that is, in the general formula (2), R ^{6 to} R ⁹ are all other than carboxy groups. And when R ^{10 to} R ¹³ are all other than a carboxy group in the general formula (3), an anion derived from an alicyclic polycarboxylic acid having a cis configuration is 80% or more (by GC (gas chromatography) analysis). (Area standard) is preferable. The steric configuration of the raw material alicyclic polycarboxylic acid is preserved even in the formation reaction of the phosphonium salt, and the cis isomer content of the raw material alicyclic polycarboxylic acid is determined so that the phosphonium cation and the alicyclic polycarboxylic acid anion are generated. This is considered to be almost the same as the cis isomer content of the salt.

  (C-1) As a salt of the phosphonium cation represented by the general formula (1-p) and the anion of (c-2) at least one alicyclic polycarboxylic acid, a known salt may be used. Alternatively, it may be produced by a known method, for example, the method described in JP-A-63-190893. For example, a tetraalkylphosphonium halide solution (solvent: water, methanol, etc.) is ion-exchanged to obtain a tetraalkylphosphonium hydroxide solution (solvent: water, methanol, etc.). At least one selected from the group consisting of the alicyclic polycarboxylic acid represented by the general formula (2) and the alicyclic polycarboxylic acid represented by the general formula (3) is added to 1 mol of hydroxide. Examples thereof include a method of forming a salt by neutralization using 5 mol to 5 mol, preferably 0.5 mol to 2 mol. Then, the target salt may be separated from the reaction mixture containing the obtained salt by removing the solvent by an appropriate method such as vacuum distillation. A commercially available tetraalkylphosphonium hydroxide that is an intermediate product may be used.

  The salt obtained by the method for forming a salt is usually a phosphonium cation represented by the general formula (1-p) and (c-2) an anion of at least one alicyclic polycarboxylic acid. The main component is a salt having a molar ratio of 1: 1. The salt having a molar ratio of 1: 1 is typically represented by the following general formula (1).

In the general formula (1), R ^{1 to} R ⁴ each independently represents a linear or branched alkyl group having 1 to 16 carbon atoms, preferably R ^{1 to} R in the general formula (1-p). ^{The same as 4} .

Further, in the general formula (1), X ⁻ is selected from the group consisting of the alicyclic polycarboxylic acid represented by the general formula (2) and the alicyclic polycarboxylic acid represented by the general formula (3). It represents an anion (monovalent anion) of at least one alicyclic polycarboxylic acid. That is, in the general formula (1), X ⁻ is selected from the group consisting of the alicyclic polycarboxylic acid represented by the general formula (2) and the alicyclic polycarboxylic acid represented by the general formula (3). In at least one alicyclic polycarboxylic acid, one of a plurality of carboxy groups is an anion formed as a carboxy anion (—COO ⁻ ).

  The salt obtained by the above method for forming a salt is not only a salt represented by the general formula (1) but having a molar ratio of 1: 1, in addition to other types of salts ((c-1) general formula (1 -P) and a salt of an anion of another alicyclic polycarboxylic acid or a divalent or higher valent anion of at least one alicyclic polycarboxylic acid), Such a reaction product may be used as it is as the curing accelerator of the present disclosure.

  Moreover, the alicyclic polycarboxylic acid represented by the general formula (2) that is industrially easily available is usually a mixture containing two or more alicyclic polycarboxylic acids represented by the general formula (2). There are many cases. Therefore, a mixture containing two or more alicyclic polycarboxylic acids represented by general formula (2) is converted into (c-1) phosphonium cation represented by general formula (1-p) and general formula (2). You may use for formation of the salt with the anion of alicyclic polycarboxylic acid represented by these. Even in such a case, as shown in the examples described later, there is a tendency to obtain an epoxy resin composition having a low viscosity and a suppressed increase in viscosity over time. Therefore, the salt represented by the general formula (1) includes (c-1) a phosphonium cation represented by the general formula (1-p) and an alicyclic group represented by two or more general formulas (2). It may be a mixture of a salt of an anion of polycarboxylic acid.

  In addition, the alicyclic polycarboxylic acid represented by the general formula (3) which is industrially easily available usually has only one alicyclic polycarboxylic acid represented by the general formula (3). Many. Therefore, one type of alicyclic polycarboxylic acid represented by general formula (3) is represented by (c-1) phosphonium cation represented by general formula (1-p) and general formula (3). You may use for formation of the salt with the anion of alicyclic polycarboxylic acid. At this time, as a salt represented by the general formula (1), (c-1) a phosphonium cation represented by the general formula (1-p) and an alicyclic group represented by one type of the general formula (3) A salt of the polycarboxylic acid with the anion is obtained. Of course, the salt represented by the general formula (1) includes (c-1) a phosphonium cation represented by the general formula (1-p) and an alicyclic group represented by two or more general formulas (3). It may be a mixture of a salt of an anion of polycarboxylic acid.

[(D) Inorganic filler]
The epoxy resin composition of the present disclosure includes (d) an inorganic filler. (D) By including an inorganic filler, it is possible to reduce hygroscopicity and improve strength when a cured product is obtained. In an epoxy resin composition containing an acid anhydride curing agent, when the content of the inorganic filler is increased, the viscosity is likely to increase, and the viscosity is likely to increase with time. On the other hand, the epoxy resin composition of the present disclosure contains a salt containing a phosphonium cation having the specific structure described above as a curing accelerator, so that the viscosity is increased even when the content of the inorganic filler is increased. It tends to be difficult to increase, and can further suppress an increase in viscosity over time.

  (D) The inorganic filler is used for improving the function and imparting the function of the cured product of the epoxy resin composition, specifically, surface hardness, heat resistance, conductivity, antistatic property, toughness, impact resistance. It is used for improving the function and imparting the function such as low thermal expansion. (D) As an inorganic filler, a metal oxide, a metal, a mineral, a carbon compound, a metal hydroxide, a filler, etc. are mentioned. (D) An inorganic filler may be used individually by 1 type, or may be used in combination of 2 or more type.

Metal oxides include silicon oxide, titanium oxide, zirconium oxide, zinc oxide, tin oxide, silicon nitride, silicon carbide, boron nitride, calcium silicate, potassium titanate, aluminum nitride, indium oxide, aluminum oxide, antimony oxide, oxidation Examples include cerium, magnesium oxide, iron oxide, tin-doped indium oxide (ITO), antimony-doped tin oxide, and fluorine-doped tin oxide.
Examples of the metal include gold, silver, copper, aluminum, nickel, iron, zinc, and stainless steel.
Examples of the mineral include montmorillonite, talc, mica, boehmite, kaolin, smectite, zonolite, verculite, and sericite.

Examples of the carbon compound include carbon black, acetylene black, ketjen black, and carbon nanotube.
Examples of the metal hydroxide include aluminum hydroxide and magnesium hydroxide.

  (D) The shape of the inorganic filler is not particularly limited, and examples thereof include powder, sphere, and fiber. Among these, spherical shape is preferable from the viewpoint of fluidity of the epoxy resin composition.

  (D) Inorganic fillers may be used as they are, or those dispersed in a resin may be used. (D) Of the inorganic fillers, silicon oxide is preferred, fused silica is more preferred, and spherical silica is more preferred from the viewpoints of fluidity and penetration into fine gaps. Further, (d) the inorganic filler may have a surface treated with a coupling agent as required.

In the present disclosure, “spherical” means that the sphericity is 0.7 or more. As a method for measuring the sphericity, for example, image processing is performed with an electron microscope, and from the observed particle area and perimeter, (sphericity) = {4π × (area) ÷ (perimeter) ² } The calculated value was used.

  Examples of the coupling agent for treating the surface of the inorganic filler include those generally used for epoxy resin compositions, and are not particularly limited. Specific examples include known coupling agents such as various silane compounds such as epoxy silane, mercapto silane, amino silane, alkyl silane, ureido silane, and vinyl silane, titanium compounds, aluminum chelate compounds, and aluminum zirconium compounds. Among these, epoxy silane is preferable.

Furthermore, it is preferable that the content rate of (d) inorganic filler is 50 mass%-90 mass% with respect to the solid content whole quantity of an epoxy resin composition, and it is more preferable that it is 75 mass%-90 mass%. Preferably, it is 80 mass%-90 mass%.
In addition, the solid content total amount of an epoxy resin composition refers to the total mass of the hardened | cured material after hardening an epoxy resin composition.

Moreover, the average particle diameter of (d) inorganic filler will not be specifically limited if it is a range with the effect of this invention, For example, it is preferable that they are 0.1 micrometer-50 micrometers, and it is 0.15 micrometers-30 micrometers. Is more preferable, and it is still more preferable that it is 0.2 micrometer-10 micrometers.
(D) When the average particle diameter of the inorganic filler is 50 μm or less, the fluidity and penetration into the fine gap of the epoxy resin composition are improved, voids are hardly generated, and the epoxy resin composition is not filled. It tends to be less likely to occur. Furthermore, the inorganic filler is less likely to bite into the connection part between the electronic component and the wiring board, and connection failure tends to be less likely to occur. Moreover, when the average particle diameter of (d) the inorganic filler is 0.1 μm or more, the epoxy resin composition tends to be largely hard to thicken.

  (D) The maximum particle size of the inorganic filler is not particularly limited as long as the effect of the present invention is achieved. For example, it is preferably 40 μm or less, more preferably 30 μm or less, and 20 μm or less. More preferably. (D) When the maximum particle size of the inorganic filler is 40 μm or less, the fluidity and penetration into the fine gaps of the epoxy resin composition are improved, voids are hardly generated, and the epoxy resin composition is not filled. It tends to be less likely to occur. Furthermore, the inorganic filler is less likely to bite into the connection part between the electronic component and the wiring board, and connection failure tends to be less likely to occur.

  (D) The minimum particle diameter of the inorganic filler is not particularly limited as long as the effect of the present invention is achieved, and is preferably, for example, 0.075 μm or more, more preferably 0.080 μm or more, More preferably, it is 0.090 μm or more. (D) When the minimum particle diameter of the inorganic filler is 0.075 μm or more, the epoxy resin composition tends to be largely thick and difficult to thicken.

The average particle diameter (D50), the maximum particle diameter, and the minimum particle diameter of the inorganic filler can be measured using a laser diffraction method. For example, the inorganic filler (d) in the epoxy resin composition is extracted and measured using a laser diffraction / scattering particle size distribution measuring device (for example, trade name: LS230, manufactured by Beckman Coulter, Inc.). Specifically, using an organic solvent, nitric acid, aqua regia, etc., (d) the inorganic filler component is extracted from the epoxy resin composition and sufficiently dispersed with an ultrasonic disperser, etc., and the volume of this dispersion is accumulated. Measure the particle size distribution curve.
The average particle diameter (D50) refers to the particle diameter at which accumulation is 50% from the small diameter side in the volume cumulative distribution curve obtained from the above measurement.

[Other ingredients]
The epoxy resin composition of the present disclosure may contain other components other than the above-mentioned (a) epoxy resin, (b) acid anhydride curing agent, (c) curing accelerator, and (d) inorganic filler. Good. Other components are not particularly limited as long as the effects of the present invention are achieved. Phenol curing agent, amine curing agent, polymercaptan curing agent, polyaminoamide curing agent, isocyanate curing agent, block isocyanate curing Curing agents other than acid anhydrides such as agents; Release agents such as paraffin, fatty acid esters and fatty acid metal salts; Coupling agents such as titanate coupling agents; Flame retardants such as brominated epoxy resins and phosphorus compounds; Flame retardant aids such as antimony oxide and antimony tetroxide; Colorants; Stress relaxation agents such as silicone oil, silicone rubber and synthetic rubber; Various additives such as antioxidants such as phenolic antioxidants and amine antioxidants Agents.

  The content of other components, preferably the total content of other components is not particularly limited as long as the effects of the present invention are achieved. For example, (a) epoxy resin, (b) acid anhydride-based curing It may be in the range of 10% by mass or less or in the range of 5% by mass or less with respect to the total of the agent, (c) curing accelerator and (d) inorganic filler.

[Modified Epoxy Resin Composition]
The epoxy resin composition of the present disclosure includes (a) an epoxy resin, (b ′) 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride, and 4-methyltetrahydroanhydride. An acid anhydride curing agent containing at least one selected from the group consisting of phthalic acid, and (c ′) a salt of a tetrabutylphosphonium cation and an anion of an alicyclic polycarboxylic acid, 1.0-1.1 may be sufficient as the equivalent ratio of the acid anhydride group in the said (b ') acid anhydride type hardening | curing agent with respect to the epoxy group in resin. Thereby, it is excellent in fluidity | liquidity and the viscosity rise with time is suppressed. Therefore, an epoxy resin composition having a low viscosity, improved temporal stability, and excellent storage stability can be obtained.
In the modified epoxy resin composition, examples of the alicyclic polycarboxylic acid include the alicyclic polycarboxylic acid represented by the above-described (c-2) general formula (2) and the general formula (3). And at least one selected from the group consisting of alicyclic polycarboxylic acids.

[Method for preparing epoxy resin composition]
The method for preparing the epoxy resin composition is not particularly limited. As a general technique, there can be mentioned a method in which components of a predetermined blending amount are sufficiently mixed with a mixer or the like, then melt-kneaded with a mixing roll, an extruder or the like, cooled, and pulverized as necessary. More specifically, for example, a predetermined amount of the above-mentioned components are stirred and mixed, kneaded with a kneader, roll, extruder, etc., heated to 70 ° C. to 140 ° C. in advance, cooled, and pulverized as necessary The method of doing can be mentioned.
Moreover, about an inorganic filler, after mixing with a coupling agent and performing surface treatment first, you may mix with another component.

[Cured product]
The cured product of the present disclosure is obtained by curing the epoxy resin composition of the present disclosure. Since the epoxy resin composition of the present disclosure is excellent in fluidity, it is suitably used for sealing an element of an electronic component device. The curing conditions for the epoxy resin composition are not particularly limited, and for example, it is preferably heated at 80 ° C. to 165 ° C. for 1 minute to 150 minutes.

[Electronic component equipment]
The electronic component device of the present disclosure includes an element that is sealed with the cured product of the present disclosure. An electronic component device manufactured using the epoxy resin composition of the present disclosure tends to be excellent in reliability because the epoxy resin composition is excellent in penetration into fine gaps.

Electronic component devices obtained using the epoxy resin composition of the present disclosure include lead frames, wired tape carriers, rigid wiring boards, flexible wiring boards, glass, silicon wafers and other supporting members (wiring boards), semiconductors Electronic components such as active elements such as chips, transistors, diodes, and thyristors, and passive elements such as capacitors, resistors, resistor arrays, coils, and switches are mounted, and necessary parts are sealed with the epoxy resin composition of the present disclosure. An electronic component device obtained in this way can be mentioned.
Specific examples include BGA (Ball Grid Array), COF (Chip On Film), COB (Chip On Board), TCP (Tape Carrier Package), CSP (Chip Size Package), WLCSP (Wafer Level). A semiconductor device such as SiP (System in Package) may be used.
The epoxy resin composition of the present disclosure is suitable as an underfill material for flip chip having excellent reliability.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, the scope of the present invention is not limited to these Examples.

<(C) Preparation of curing accelerator>
(Production Example 1)
(C) A curing accelerator was prepared as follows.
First, 100 parts by mass of a 40% by mass aqueous solution of tetrabutylphosphonium hydroxide was added to bicyclo [2.2.1] heptane-2,3-dicarboxylic acid / methylbicyclo [2.2.1] heptane-2,3-dicarboxylic acid. The reaction mixture was obtained by adding 42 parts by mass of an acid (mass ratio 1/4) mixture to neutralize the mixture. The obtained reaction mixture was dehydrated by a vacuum distillation method, and a tetrabutylphosphonium cation as a curing accelerator and bicyclo [2.2.1] heptane-2,3-dicarboxylic acid / methylbicyclo [2.2.1]. ] 80 parts by mass of a salt of heptane-2,3-dicarboxylic acid (mass ratio 1/4) with an anion (hereinafter also referred to as “TBP / HNA salt”) was obtained.

  Bicyclo [2.2.1] heptane-2,3-dicarboxylic acid and methylbicyclo [2.2.1] heptane-2,3-dicarboxylic acid used as raw materials are a mixture of cis and trans isomers. However, it was confirmed by GC (gas chromatography) measurement that the cis-isomer was 95% by mass.

(Production Example 2)
To 100 parts by mass of a 40% by mass aqueous solution of tetrabutylphosphonium hydroxide, 38 parts by mass of 1,2,4,5-cyclohexanetetracarboxylic acid was added for neutralization to obtain a reaction mixture. The obtained reaction mixture was dehydrated by distillation under reduced pressure, and a salt of tetrabutylphosphonium cation as a curing accelerator and an anion of 1,2,4,5-cyclohexanetetracarboxylic acid (hereinafter referred to as “TBP / HPMA salt”). Also obtained.) 76 parts by mass were obtained.

<Preparation of epoxy resin composition>
Example 1
(A) Epoxy resin jER630 (Mitsubishi Chemical Corporation; aminophenol type epoxy resin, epoxy equivalent 95 g / eq) 100 parts by mass and (b) acid anhydride type curing agent HN-2000 (Hitachi Chemical Co., Ltd.) Manufactured by: 3or4-methyltetrahydrophthalic anhydride, acid anhydride equivalent: 166 g / eq) to a mixture of 175 parts by mass with a coupling agent S510 (manufactured by Himi Corporation; 3-glycidoxypropyltrimethoxysilane) (D) ST7010-2 (manufactured by Micron Corporation; fused silica, average particle diameter 11 μm) and SO-25R (manufactured by Admatech Co., Ltd .; fused silica, average particle diameter 0.6 μm) which are surface-treated (d) inorganic fillers Was added so that the amount of the inorganic filler was 88% by mass relative to the whole. These were mixed using three rolls to obtain a curing agent liquid. 2 parts by mass of the TBP / HNA salt, which is the curing accelerator obtained in Production Example 1, is added to the curing agent solution, and 10 parts by mass of the colorant MA-100 (manufactured by Mitsubishi Chemical Corporation, carbon microbeads). Added, further mixed and vacuum degassed. This obtained the epoxy resin composition which is liquid at normal temperature.

(Examples 2 and 3)
An epoxy resin composition was obtained in the same manner as in Example 1 except that the blending ratio of each component was changed to the amounts shown in Table 1.

(Examples 4 to 6)
Example 1 except that the TBP / HPMA salt obtained in Production Example 2 was used instead of the TBP / HNA salt as a curing accelerator, and the blending ratio of each component was changed to the amounts shown in Tables 1 and 2. Similarly, an epoxy resin composition was obtained.

(Comparative Example 1)
U-CAT SA102 (manufactured by San Apro Co., Ltd., 1,8-diazabicyclo (5.4.0) undecene-7.octylate) is used instead of TBP / HNA salt which is a curing accelerator, and each component An epoxy resin composition was obtained in the same manner as in Example 1 except that the blending ratio was changed to the amount shown in Table 1.

<Measurement of viscosity and stability over time>
About the epoxy resin composition in each Example and Comparative Example 1, the viscosity immediately after preparation was measured. Specifically, the temperature of the epoxy resin composition was kept at 25 ° C., and measurement was performed using a B-type rotational viscometer according to JIS K 7117-1: 1999.
Moreover, after keeping the temperature of the epoxy resin composition immediately after preparation at 25 degreeC and leaving still for 24 hours, it measured using the B-type rotational viscometer according to JISK7117-1: 1999.
The temporal stability of the epoxy resin composition was calculated by (viscosity after 24 hours) / (viscosity immediately after preparation). The smaller this value, the smaller the change in viscosity with time and the better the stability over time.
The results are shown in Table 1. In Comparative Example 1, the viscosity after 24 hours was more than 3000 Pa · s.
In Examples 2, 3, 5 and 6, the viscosity was measured at a rotational speed of 10 rpm, while in Examples 1, 4 and Comparative Example 1, the viscosity was measured at a rotational speed of 1.0 rpm.

If the viscosity of the epoxy resin composition immediately after preparation is 100 Pa · s or less and the viscosity of the epoxy resin composition after 24 hours is 1000 Pa · s or less, there is no problem with fluidity and stability over time, for example, It can be suitably applied to WLCSP. Therefore, the epoxy resin compositions of Examples 1 to 6 can be suitably applied to the above uses.
On the other hand, the epoxy resin composition of Comparative Example 1 had a viscosity immediately after preparation of over 100 Pa · s, and a viscosity after 24 hours of over 1000 Pa · s. Therefore, the epoxy resin composition of Comparative Example 1 does not have good fluidity and is difficult to apply to the above uses.
Further, in Comparative Example 1, the change in viscosity over time (viscosity increase) was remarkable as compared with Examples 1 to 6, and the temporal stability was not good.

Claims (14)

(A) an epoxy resin, (b) an acid anhydride curing agent, (c) a curing accelerator, and (d) an inorganic filler,
The (c) curing accelerator is an epoxy resin composition containing (c-1) a salt containing a phosphonium cation represented by the following general formula (1-p).

(In the general formula (1-p), R ^{1 to} R ⁴ each independently represents a linear or branched alkyl group having 1 to 16 carbon atoms.)   2. The epoxy resin composition according to claim 1, wherein the content of the (d) inorganic filler is 50% by mass to 90% by mass with respect to the total solid content of the epoxy resin composition.   The epoxy resin composition according to claim 1 or 2, wherein the average particle diameter of the (d) inorganic filler is 0.1 µm to 50 µm. In the said general formula (1-p), all of R < ¹ > -R < ⁴ > is a butyl group, The epoxy resin composition of any one of Claims 1-3. The (c) curing accelerator is a group consisting of (c-2) an alicyclic polycarboxylic acid represented by the following general formula (2) and an alicyclic polycarboxylic acid represented by the following general formula (3). The epoxy resin composition according to any one of claims 1 to 4, which is a salt containing an anion of at least one alicyclic polycarboxylic acid selected from the group consisting of:

(In General Formula (2), R ⁵ represents a methylene group or an ethylene group, and R ^{6 to} R ⁹ each independently represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, Or represents a carboxy group.)

(In General Formula (3), R ^{10 to} R ¹³ each independently represent a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, or a carboxy group.) The anion of the at least one alicyclic polycarboxylic acid is (a) an alicyclic polycarboxylic acid in which R ⁵ is a methylene group and all of R ^{6 to} R ⁹ are hydrogen atoms in the general formula (2). Acid and (i) In the general formula (2), R ⁵ is a methylene group, any one of R ^{6 to} R ⁹ is a methyl group, and the remaining three are hydrogen atoms. The epoxy resin composition according to claim 5, comprising an anion of at least one alicyclic polycarboxylic acid selected from the group consisting of carboxylic acids. The anion of the at least one alicyclic polycarboxylic acid includes (i) an alicyclic polycarboxylic acid in which all of R ^{10 to} R ¹³ are hydrogen atoms in the general formula (3), and (ii) general In Formula (3), any two of R ^{10 to} R ¹³ are carboxy groups, and the remaining two are hydrogen atoms, and at least one alicyclic polycarboxylic acid selected from the group consisting of alicyclic polycarboxylic acids. The epoxy resin composition of Claim 5 or Claim 6 containing the anion of carboxylic acid.   The (c) curing accelerator includes bicyclo [2.2.1] heptane-2,3-dicarboxylic acid, methylbicyclo [2.2.1] heptane-2,3-dicarboxylic acid and 1,2,4, The epoxy resin composition according to any one of claims 1 to 4, comprising an anion of at least one alicyclic polycarboxylic acid selected from the group consisting of 5-cyclohexanetetracarboxylic acid.   The (a) epoxy resin is bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, naphthalenediol diglycidyl ether, 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexanecarboxylate, hydrogenated bisphenol A di The epoxy resin composition according to any one of claims 1 to 8, comprising at least one selected from the group consisting of glycidyl ether and N, N-diglycidyl-4-glycidyloxyaniline.   The (b) acid anhydride curing agent is selected from the group consisting of 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride and 4-methyltetrahydrophthalic anhydride. The epoxy resin composition according to any one of claims 1 to 9, comprising at least one selected from the group consisting of:   The equivalent ratio of the acid anhydride group in the (b) acid anhydride curing agent to the epoxy group in the (a) epoxy resin is 0.9 to 1.2. 2. The epoxy resin composition according to item 1. (A) an epoxy resin, (b ′) at least selected from the group consisting of 3-methylhexahydrophthalic anhydride, 4-methylhexahydrophthalic anhydride, 3-methyltetrahydrophthalic anhydride and 4-methyltetrahydrophthalic anhydride An acid anhydride curing agent containing one kind, and (c ′) a salt of a tetrabutylphosphonium cation and an anion of an alicyclic polycarboxylic acid,
The epoxy resin composition whose equivalent ratio of the acid anhydride group in the said (b ') acid anhydride type hardening | curing agent with respect to the epoxy group in said (a) epoxy resin is 1.0-1.1.   Hardened | cured material of the epoxy resin composition of any one of Claims 1-12.   An electronic component device comprising an element sealed with the cured product according to claim 13.