JP7460025B2 - Resin composition for semiconductor encapsulation and semiconductor device - Google Patents

Description

The present invention relates to a resin composition for semiconductor encapsulation and a semiconductor device.

Thermosetting resin compositions (sealing resin compositions) are known as materials for sealing semiconductor packages and the like.

Patent documents 1 and 2 disclose an encapsulating resin composition containing an epoxy resin, an active ester compound as a curing agent, and an inorganic filler having a predetermined average particle size.

Patent Document 3 discloses an encapsulating resin composition containing an epoxy resin including a multifunctional epoxy resin and a difunctional epoxy resin, and an active ester compound as a curing agent.

International Publication No. 2020/065872 International Publication No. 2020/065873 International Publication No. 2020/066856

However, the conventional sealing resin compositions described in Patent Documents 1 to 3 have a high shrinkage rate during molding, a low product yield, and the resulting sealant has low mechanical strength and dielectric properties. There was room for improvement.

The present inventors have discovered that the above problems can be solved by using a resin composition for semiconductor encapsulation that uses a phenol resin and an active ester resin together as a curing agent and contains a predetermined curing accelerator, and has completed the present invention. I let it happen.
That is, the present invention can be shown below.

（一般式（１）において、Ａは、脂肪族環状炭化水素基を介して連結された置換または非置換のアリーレン基であり、
Ａｒ’は、置換または非置換のアリール基であり、
ｋは、繰り返し単位の平均値であり、０．２５～３．５の範囲であり、
一般式（１）においてＢは、一般式（Ｂ）で表される構造であり、

（一般式（Ｂ）中、Ａｒは、置換または非置換のアリーレン基であり、Ｙは、単結合、置換または非置換の炭素原子数１～６の直鎖のアルキレン基、または置換または非置換の炭素原子数３～６の環式のアルキレン基、置換または非置換の２価の芳香族炭化水素基、エーテル結合、カルボニル基、カルボニルオキシ基、スルフィド基、あるいはスルホン基である。ｎは０～４の整数である。）
硬化促進剤（Ｃ）は、テトラフェニルホスホニウム－４，４’－スルフォニルジフェノラート、テトラフェニルホスホニウムビス（ナフタレン－２，３－ジオキシ）フェニルシリケート、４－ヒドロキシ－２－（トリフェニルホスホニウム）フェノラートからなる群より選択される１種または２種以上を含む、半導体封止用樹脂組成物。
［２］ ［１］に記載の半導体封止用樹脂組成物であって、
前記一般式（Ｂ）で表される構造は、一般式（Ｂ－１）～（Ｂ－６）から選択される少なくとも１つである、半導体封止用樹脂組成物。

（一般式（Ｂ－１）～（Ｂ－６）中、Ｒ^１は、それぞれ独立に水素原子、炭素原子数１～４のアルキル基、炭素原子数１～４のアルコキシ基、フェニル基、またはアラルキル基であり、Ｒ^２はそれぞれ独立に炭素原子数１～４のアルキル基、炭素原子数１～４のアルコキシ基、またはフェニル基であり、Ｘは炭素原子数２～６の直鎖のアルキレン基、エーテル結合、カルボニル基、カルボニルオキシ基、スルフィド基、スルホン基のいずれかであり、ｎは０～４の整数であり、ｐは１～４の整数である。）
［３］ ［１］または［２］に記載の半導体封止用樹脂組成物であって、
前記一般式（１）において、Ａが、一般式（Ａ）で表される構造を有する、半導体封止用樹脂組成物。

（一般式（Ａ）中、Ｒ^３はそれぞれ独立に水素原子、炭素原子数１～４のアルキル基、炭素原子数１～４のアルコキシ基、フェニル基、アラルキル基の何れかであり、ｌは０または１であり、ｍは１以上の整数である）
［４］ ［１］～［３］のいずれかに記載の半導体封止用樹脂組成物であって、
フェノール樹脂（Ｂ１）の含有量と活性エステル樹脂（Ｂ２）の含有量の比率が、２５：７５～７５：２５である、半導体封止用樹脂組成物。
［５］ ［１］～［４］のいずれかに記載の半導体封止用樹脂組成物であって、
さらにカップリング剤（Ｄ）を含む、半導体封止用樹脂組成物。
［６］ ［５］に記載の半導体封止用樹脂組成であって、
カップリング剤（Ｄ）が２級アミノシランカップリング剤である、半導体封止用樹脂組成物。
［７］ ［１］～［６］のいずれかに記載の半導体封止用樹脂組成であって
エポキシ樹脂（Ａ）およびフェノール樹脂（Ｂ１）の少なくとも一方が、ビフェニルアラルキル構造を有する、半導体封止用樹脂組成物。
［８］ ［１］～［７］のいずれかに記載の半導体封止用樹脂組成であって
フェノール樹脂（Ｂ１）が、ビフェニルアラルキル構造を有する、半導体封止用樹脂組成物。
［９］ ［１］～［８］のいずれかに記載の半導体封止用樹脂組成であって、
エポキシ樹脂（Ａ）が、ビフェニルアラルキル型樹脂およびジシクロペンタジエン型樹脂から選択される少なくとも１種を含む、半導体封止用樹脂組成物。
［１０］ ［１］～［９］のいずれかに記載の半導体封止用樹脂組成物であって、
さらにシリコーンオイル（Ｅ）を含む、半導体封止用樹脂組成物。
［１１］ ［１］～［１０］のいずれかに記載の半導体封止用樹脂組成物であって、
さらに無機充填剤（Ｆ）を含む、半導体封止用樹脂組成物。
［１２］ ［１１］に記載の半導体封止用樹脂組成物であって、
無機充填剤（Ｆ）が、シリカ、アルミナ、タルク、酸化チタン、窒化珪素、窒化アルミニウムから選択される少なくとも１種である、半導体封止用樹脂組成物。
［１３］ ［１］～［１２］のいずれかに記載の半導体封止用樹脂組成物であって、
当該半導体封止用樹脂組成物のゲルタイムが５０秒以上８０秒以下である、半導体封止用樹脂組成物。
［１４］ 半導体素子と、
［１］～［１３］のいずれかに記載の半導体封止用樹脂組成物の硬化物からなる、前記半導体素子を封止する封止材と、
を備える、半導体装置。 [1] (A) an epoxy resin,
(B) a curing agent; and
(C) a curing accelerator,
The curing agent (B) contains a phenol resin (B1) and an active ester resin (B2),
The active ester resin (B2) has a structure represented by general formula (1):

In the general formula (1), A is a substituted or unsubstituted arylene group linked via an aliphatic cyclic hydrocarbon group,
Ar' is a substituted or unsubstituted aryl group;
k is the average value of the repeating units, ranging from 0.25 to 3.5;
In general formula (1), B is a structure represented by general formula (B),

(In general formula (B), Ar is a substituted or unsubstituted arylene group, Y is a single bond, a substituted or unsubstituted linear alkylene group having 1 to 6 carbon atoms, or a substituted or unsubstituted cyclic alkylene group having 3 to 6 carbon atoms, a substituted or unsubstituted divalent aromatic hydrocarbon group, an ether bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group. n is an integer of 0 to 4.)
The curing accelerator (C) is one or more selected from the group consisting of tetraphenylphosphonium-4,4'-sulfonyldiphenolate, tetraphenylphosphonium bis(naphthalene-2,3-dioxy)phenylsilicate, and 4-hydroxy-2-(triphenylphosphonium)phenolate.
[2] The resin composition for semiconductor encapsulation according to [1],
The structure represented by the general formula (B) is at least one selected from general formulas (B-1) to (B-6).

(In general formulas (B-1) to (B-6), R ¹ 's are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group; R ² 's are each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group; X is any one of a linear alkylene group having 2 to 6 carbon atoms, an ether bond, a carbonyl group, a carbonyloxy group, a sulfide group, and a sulfone group; n is an integer of 0 to 4; and p is an integer of 1 to 4.)
[3] The resin composition for semiconductor encapsulation according to [1] or [2],
A resin composition for semiconductor encapsulation, wherein in the general formula (1), A has a structure represented by general formula (A).

(In the general formula (A), ^R3 is independently any one of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, and an aralkyl group, l is 0 or 1, and m is an integer of 1 or more.)
[4] The resin composition for semiconductor encapsulation according to any one of [1] to [3],
A resin composition for semiconductor encapsulation, wherein the ratio of the content of the phenol resin (B1) to the content of the active ester resin (B2) is 25:75 to 75:25.
[5] The resin composition for semiconductor encapsulation according to any one of [1] to [4],
The resin composition for semiconductor encapsulation further comprises a coupling agent (D).
[6] The resin composition for semiconductor encapsulation according to [5],
A resin composition for semiconductor encapsulation, wherein the coupling agent (D) is a secondary aminosilane coupling agent.
[7] The resin composition for semiconductor encapsulation according to any one of [1] to [6], wherein at least one of the epoxy resin (A) and the phenolic resin (B1) has a biphenylaralkyl structure.
[8] The resin composition for semiconductor encapsulation according to any one of [1] to [7], wherein the phenolic resin (B1) has a biphenylaralkyl structure.
[9] The resin composition for semiconductor encapsulation according to any one of [1] to [8],
A resin composition for semiconductor encapsulation, comprising an epoxy resin (A) containing at least one selected from a biphenylaralkyl type resin and a dicyclopentadiene type resin.
[10] The resin composition for semiconductor encapsulation according to any one of [1] to [9],
The resin composition for semiconductor encapsulation further comprises a silicone oil (E).
[11] The resin composition for semiconductor encapsulation according to any one of [1] to [10],
The resin composition for semiconductor encapsulation further comprises an inorganic filler (F).
[12] The resin composition for semiconductor encapsulation according to [11],
A resin composition for semiconductor encapsulation, wherein the inorganic filler (F) is at least one selected from the group consisting of silica, alumina, talc, titanium oxide, silicon nitride, and aluminum nitride.
[13] The resin composition for semiconductor encapsulation according to any one of [1] to [12],
The semiconductor encapsulation resin composition has a gel time of 50 seconds or more and 80 seconds or less.
[14] A semiconductor element;
An encapsulant for encapsulating the semiconductor element, the encapsulant being made of a cured product of the semiconductor encapsulation resin composition according to any one of [1] to [13];
A semiconductor device comprising:

The resin composition for semiconductor encapsulation of the present invention has a low shrinkage rate during molding and has an excellent product yield, and a cured product obtained from the composition has excellent mechanical strength and dielectric properties. In other words, the resin composition for semiconductor encapsulation of the present invention has an excellent balance of these properties.

FIG. 1 is a cross-sectional view showing the configuration of a semiconductor device in an embodiment. FIG. 1 is a cross-sectional view showing the configuration of a semiconductor device in an embodiment.

The following describes an embodiment of the present invention with reference to the drawings. In all drawings, similar components are given similar reference symbols and descriptions will be omitted where appropriate. In addition, "~" indicates "above" to "below" unless otherwise specified.

The semiconductor encapsulation resin composition of the present embodiment includes an epoxy resin (A), a curing agent (B), and a curing accelerator (C).
Each component contained in the semiconductor encapsulation resin composition (hereinafter also referred to as encapsulation resin composition) of this embodiment will be described below.

[Epoxy resin (A)]
The epoxy resin (A) is a compound having two or more epoxy groups in one molecule, and may be any of a monomer, an oligomer, and a polymer.

Specifically, the epoxy resin (A) includes crystalline epoxy resins such as biphenyl-type epoxy resins, bisphenol-type epoxy resins, and stilbene-type epoxy resins; novolac-type epoxy resins such as phenol novolac-type epoxy resins and cresol novolac-type epoxy resins. ; Multifunctional epoxy resins such as trisphenylmethane type epoxy resins and alkyl-modified triphenolmethane type epoxy resins; Phenol aralkyl type epoxy resins such as phenylene skeleton-containing phenol aralkyl type epoxy resins and biphenylene skeleton containing phenol aralkyl type epoxy resins; Dihydroxynaphthalene naphthol type epoxy resins, such as epoxy resins obtained by glycidyl etherification of dihydroxynaphthalene dimers; triazine nucleus-containing epoxy resins such as triglycidyl isocyanurate and monoallyl diglycidyl isocyanurate; dicyclopentadiene-modified phenols One or more types selected from the group consisting of bridged cyclic hydrocarbon compound-modified phenol type epoxy resins such as type epoxy resins.

From the viewpoint of the effects of the present invention, the epoxy resin (A) is preferably one or more selected from the group consisting of trisphenylmethane type epoxy resins, biphenyl aralkyl type multifunctional epoxy resins, orthocresol type bifunctional epoxy resins, biphenyl type bifunctional epoxy resins, bisphenol type bifunctional epoxy resins, and dicyclopentadiene type bifunctional epoxy resins. It is more preferable that the epoxy resin (A) is a biphenyl aralkyl type multifunctional epoxy resin or a dicyclopentadiene type bifunctional epoxy resin.

The content of the epoxy resin (A) in the encapsulating resin composition is preferably 2 mass % or more, more preferably 3 mass % or more, and even more preferably 4 mass % or more, based on the entire encapsulating resin composition, from the viewpoint of obtaining suitable fluidity during molding and improving filling property and moldability.
From the viewpoint of improving the reliability of a device obtained by using the encapsulating resin composition, the content of the epoxy resin (A) in the encapsulating resin composition is preferably 40 mass % or less, more preferably 30 mass % or less, further preferably 20 mass % or less, and particularly preferably 10 mass % or less, based on the entire encapsulating resin composition.

[Curing agent (B)]
In this embodiment, the curing agent (B) includes a phenol resin (B1) and an active ester resin (B2).

(Phenol resin (B1))
As the phenol resin (B1), those commonly used in sealing resin compositions can be used as long as the effects of the present invention are achieved.

Examples of the phenolic resin (B1) include novolac resins obtained by condensing or co-condensing phenols such as phenol novolac resins and cresol novolac resins with formaldehyde or ketones under an acidic catalyst, phenol aralkyl resins having a biphenylene skeleton synthesized from the above-mentioned phenols and dimethoxy-paraxylene or bis(methoxymethyl)biphenyl, phenol aralkyl resins such as phenol aralkyl resins having a phenylene skeleton, and phenolic resins having a trisphenylmethane skeleton. These may be used alone or in combination of two or more.

In this embodiment, the phenol resin (B1) preferably has a biphenylaralkyl structure from the viewpoint of the effects of the present invention, and specifically, a phenol aralkyl resin having a biphenylene skeleton is preferable. Phenol resin with a biphenylaralkyl structure has low moisture absorption, low elasticity, and excellent reliability.
In this embodiment, it is preferable that one or both of the epoxy resin (A) and the phenol resin (B1) have a biphenylaralkyl structure.

(Active ester resin (B2))
As the active ester resin (B2), a resin having a structure represented by the following general formula (1) can be used.

In formula (1), "B" is a structure represented by formula (B).

In formula (B), Ar is a substituted or unsubstituted arylene group. Examples of the substituent of the substituted arylene group include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, and an aralkyl group.
Y is a single bond, a substituted or unsubstituted linear alkylene group having 1 to 6 carbon atoms, a substituted or unsubstituted cyclic alkylene group having 3 to 6 carbon atoms, a substituted or unsubstituted divalent aromatic hydrocarbon group, an ether bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group. Examples of the substituent of the above groups include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, and an aralkyl group.
Preferred examples of Y include a single bond, a methylene group, -CH(CH ₃ ) ₂ -, an ether bond, an optionally substituted cycloalkylene group, and an optionally substituted 9,9-fluorenylene group.
n is an integer of 0 to 4, preferably 0 or 1.
Specifically, B is a structure represented by the following general formula (B1) or the following general formula (B2).

In the general formula (B1) and the general formula (B2), Ar and Y have the same meanings as in the general formula (B).

A is a substituted or unsubstituted arylene group linked via an aliphatic cyclic hydrocarbon group;
Ar' is a substituted or unsubstituted aryl group;
k is the average value of the repeating units and is in the range of 0.25 to 3.5.

The semiconductor encapsulation resin composition of this embodiment contains a specific active ester resin (B2) in addition to a phenolic resin (B1), and thus produces a cured product (encapsulant) that has low shrinkage during molding, excellent product yield, and excellent mechanical strength and low dielectric tangent.

The active ester resin (B2) used in the semiconductor encapsulation resin composition of this embodiment has an active ester group represented by formula (B). In the curing reaction between the epoxy resin (A) and the active ester resin (B2), the active ester group of the active ester resin (B2) reacts with the epoxy group of the epoxy resin to generate a secondary hydroxyl group. This secondary hydroxyl group is blocked by the ester residue of the active ester resin (B2). As a result, the dielectric tangent of the cured product is reduced.

In one embodiment, the structure represented by the above formula (B) is preferably at least one selected from the following formulas (B-1) to (B-6).

In formulas (B-1) to (B-6),
R ¹ is each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group,
R ² is each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group, and X is a linear alkylene group having 2 to 6 carbon atoms, an ether a bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group,
n is an integer from 0 to 4, and p is an integer from 1 to 4.

The structures represented by formulas (B-1) to (B-6) above are all structures with high orientation, so when an active ester resin (B2) containing them is used, the resulting resin composition The cured product has a low dielectric constant and a low dielectric loss tangent, and has excellent adhesion to metals, so it can be suitably used as a semiconductor encapsulation material.
Among these, from the viewpoint of low dielectric constant and low dielectric loss tangent, active ester resin (B2) having a structure represented by formula (B-2), formula (B-3) or (B-5) is preferable, and A structure in which n is 0 in (B-2), a structure in which X in formula (B-3) is an ether bond, or a structure in which two carbonyloxy groups are at the 4,4'-position in formula (B-5) An active ester resin (B2) having a structure is more preferable. Further, it is preferable that all R ¹ in each formula are hydrogen atoms.

"Ar'" in formula (1) is an aryl group, for example, phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 3,5-xylyl group, o-biphenyl group, m-biphenyl group. p-biphenyl group, 2-benzylphenyl group, 4-benzylphenyl group, 4-(α-cumyl)phenyl group, 1-naphthyl group, 2-naphthyl group, etc. Among these, 1-naphthyl group or 2-naphthyl group is preferable because a cured product with particularly low dielectric constant and dielectric loss tangent can be obtained.

In this embodiment, "A" in the active ester resin (B2) represented by formula (1) is a substituted or unsubstituted arylene group linked via an aliphatic cyclic hydrocarbon group. Examples of such arylene groups include a structure obtained by a polyaddition reaction between an unsaturated aliphatic cyclic hydrocarbon compound containing two double bonds in one molecule and a phenolic compound.

Examples of the unsaturated aliphatic cyclic hydrocarbon compounds containing two double bonds in one molecule include dicyclopentadiene, cyclopentadiene polymers, tetrahydroindene, 4-vinylcyclohexene, 5-vinyl-2-norbornene, limonene, etc., which may be used alone or in combination of two or more. Among these, dicyclopentadiene is preferred because it gives a cured product with excellent heat resistance. Since dicyclopentadiene is contained in petroleum fractions, industrial dicyclopentadiene may contain cyclopentadiene polymers and other aliphatic or aromatic diene compounds as impurities. However, in consideration of performance such as heat resistance, curability, and moldability, it is desirable to use a product with a purity of 90% by mass or more of dicyclopentadiene.

On the other hand, examples of the phenolic compound include phenol, cresol, xylenol, ethylphenol, isopropylphenol, butylphenol, octylphenol, nonylphenol, vinylphenol, isopropenylphenol, allylphenol, phenylphenol, benzylphenol, chlorophenol, bromophenol, 1-naphthol, 2-naphthol, 1,4-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, etc., and each may be used alone or two or more types may be used in combination. Among these, phenol is preferred because it is highly curable and results in an active ester resin (B2) with excellent dielectric properties in the cured product.

In a preferred embodiment, "A" in the active ester resin (B2) represented by formula (1) has a structure represented by formula (A). A resin composition containing an active ester resin (B2) in which "A" in formula (1) has the following structure has a cured product having a low dielectric constant and a low dielectric loss tangent, and has excellent adhesion to insert products.

In formula (A),
R ³ is each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group,
l is 0 or 1, and m is an integer of 1 or more.

Among the active ester curing agents represented by formula (1), more preferred are the resins represented by the following formulas (1-1), (1-2) and (1-3), and particularly preferred is the resin represented by the following formula (1-3).

In formula (1-1), R ¹ and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group. , Z is a phenyl group, a naphthyl group, or a phenyl group or a naphthyl group having 1 to 3 alkyl groups having 1 to 4 carbon atoms on the aromatic nucleus, l is 0 or 1, and k is a repeating unit. It is the average of 0.25 to 3.5.

In formula (1-2), R ¹ and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group. , Z is a phenyl group, a naphthyl group, or a phenyl group or a naphthyl group having 1 to 3 alkyl groups having 1 to 4 carbon atoms on the aromatic nucleus, l is 0 or 1, and k is a repeating unit. It is the average of 0.25 to 3.5.

In formula (1-3), R ¹ and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group. , Z is a phenyl group, a naphthyl group, or a phenyl group or a naphthyl group having 1 to 3 alkyl groups having 1 to 4 carbon atoms on the aromatic nucleus, l is 0 or 1, and k is a repeating unit. It is the average of 0.25 to 3.5.

The active ester resin (B2) used in the present invention can be produced by a known method in which a phenolic compound (a) having a structure in which multiple aryl groups having phenolic hydroxyl groups are linked via an aliphatic cyclic hydrocarbon group, an aromatic nucleus-containing dicarboxylic acid or its halide (b), and an aromatic monohydroxy compound (c) are reacted.

The reaction ratio of the phenolic compound (a), the aromatic nucleus-containing dicarboxylic acid or its halide (b), and the aromatic monohydroxy compound (c) can be adjusted as appropriate depending on the desired molecular design. Among them, since an active ester resin (B2) with higher curability is obtained, the phenolic compound is The ratio of the phenolic hydroxyl group possessed by (a) being in the range of 0.25 to 0.90 mol, and the hydroxyl group possessed by the aromatic monohydroxy compound (c) being in the range of 0.10 to 0.75 mol. It is preferable to use each raw material in such a manner that the phenolic hydroxyl group of the phenolic compound (a) is in the range of 0.50 to 0.75 mol, and the hydroxyl group of the aromatic monohydroxy compound (c) is in the range of 0.50 to 0.75 mol. It is more preferable to use each raw material in a proportion ranging from 0.25 to 0.50 mol.

In addition, when the sum of the arylcarbonyloxy groups and phenolic hydroxyl groups contained in the resin structure is taken as the number of functional groups of the resin, the functional group equivalent of the active ester resin (B2) is preferably in the range of 200 g/eq or more and 230 g/eq or less, and more preferably in the range of 210 g/eq or more and 220 g/eq or less, since this gives a cured product with excellent curability and low dielectric constant and dielectric tangent.

The curing agent (B) of this embodiment contains a phenolic resin (B1) and an active ester resin (B2) in combination.
As a result, the semiconductor encapsulation resin composition of the present embodiment has a low shrinkage rate during molding and is excellent in product yield, and further, the cured product obtained from the composition has excellent mechanical strength and low dielectric tangent.

In this embodiment, the equivalent ratio of curing agent (B) to epoxy resin (A) (curing agent (B)/epoxy resin (A)) is 0.50 to 1.00 from the viewpoint of the effects of the present invention. , preferably 0.52 to 0.95, more preferably 0.55 to 0.90, particularly preferably 0.60 to 0.80.

In this embodiment, the equivalent ratio of active ester resin (B2) to epoxy resin (A) (active ester resin (B2)/epoxy resin (A)) is 0.10 to 0.60, preferably 0.12. ~0.50, more preferably 0.15~0.47, particularly preferably 0.17~0.45.
As a result, since the resin composition for semiconductor encapsulation of this embodiment has excellent curability, the shrinkage rate during molding is lower and the yield of the product is higher. Furthermore, the cured product obtained from the composition has excellent mechanical strength and Even better in low dielectric loss tangent.
When the equivalent ratio (B2/A) exceeds the upper limit, the dielectric loss tangent decreases because the hydroxyl group generated when the epoxy group opens is likely to be capped with the active ester. However, in the curing agent (B) that uses a phenol curing agent (B1) and an active ester resin (B2) in combination as in the present embodiment, when the upper limit of the equivalent ratio (B2/A) is exceeded, the phenol The phenol hydroxyl group of the curing agent (B1) and the active ester of the active ester resin (B2) interact and affect the curing of the epoxy resin (A), resulting in variations in curing properties (spiral flow, gel time, etc.) and poor heat resistance. Problems arise such as the properties (Tg, etc.) and mechanical properties (bending strength, flexural modulus, etc.) are reduced, and it becomes difficult to control homogeneous dielectric properties (uniformity of dielectric properties within the cured body).

In this embodiment, the equivalent ratio of phenolic resin (B1) to epoxy resin (A) (phenolic resin (B1)/epoxy resin (A)) can be, from the viewpoint of the effects of the present invention, 0.10 to 0.70, preferably 0.15 to 0.65, more preferably 0.18 to 0.60, and particularly preferably 0.20 to 0.55.

From the viewpoint of the effects of the present invention, the ratio of the content (parts by weight) of the phenolic resin (B1) to the content (parts by weight) of the active ester resin (B2) in the curing agent (B) can be 25:75 to 75:25, preferably 30:70 to 70:30.

In the resin composition of this embodiment, the blending amount of the curing agent (B) containing the phenolic resin (B1) and the active ester resin (B2) and the epoxy resin (A) is preferably such that the epoxy groups in the epoxy resin are 0.8 to 1.2 equivalents per equivalent of the total of the active groups in the curing agent (B), since this gives a cured product with excellent curing properties and low dielectric constant and dielectric tangent. Here, the active groups in the curing agent (B) refer to the arylcarbonyloxy groups and phenolic hydroxyl groups in the resin structure.

In the composition of the present embodiment, the curing agent (B) is used in an amount of preferably 0.2 mass % or more and 15 mass % or less, more preferably 0.5 mass % or more and 10 mass % or less, and even more preferably 1.0 mass % or more and 7 mass % or less, based on the entire encapsulating resin composition.
By including the curing agent (B) in the above range, the obtained cured product can have better dielectric properties and is further superior in low dielectric tangent.

[Curing Accelerator (C)]
The curing accelerator (C) contains one or more selected from the group consisting of tetraphenylphosphonium-4,4'-sulfonyldiphenolate, tetraphenylphosphonium bis(naphthalene-2,3-dioxy)phenylsilicate, and 4-hydroxy-2-(triphenylphosphonium)phenolate. In this embodiment, two types may be contained.

The content of the curing accelerator in the encapsulating resin composition is preferably 0.01% by mass or more based on the entire encapsulating resin composition from the viewpoint of improving the curing characteristics of the encapsulating resin composition. The content is preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more.
Moreover, from the viewpoint of obtaining preferable fluidity during molding of the sealing resin composition, the content of the curing accelerator in the sealing resin composition is preferably 2. It is 0% by mass or less, more preferably 1.0% by mass or less, even more preferably 0.5% by mass or less.

[Coupling Agent (D)]
The encapsulating resin composition of the present embodiment may contain a coupling agent (D).
Examples of the coupling agent (D) include aminosilanes such as epoxysilane, mercaptosilane, and phenylaminosilane. From the viewpoint of improving the adhesion between the sealing material and the metal member, the coupling agent (D) is preferably an epoxysilane or an aminosilane, and more preferably a secondary aminosilane. From the same viewpoint, the coupling agent (D) is preferably one or more selected from the group consisting of phenylaminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane.

The content of the coupling agent (D) in the encapsulating resin composition is preferably 0.01 mass % or more, and more preferably 0.05 mass % or more, based on the entire encapsulating resin composition, from the viewpoint of obtaining favorable fluidity during molding of the encapsulating resin composition.
In addition, from the viewpoint of suppressing an increase in the resin viscosity, the content of the coupling agent (D) in the encapsulating resin composition is preferably 2.0 mass % or less, more preferably 1.0 mass % or less, and even more preferably 0.5 mass % or less, based on the entire encapsulating resin composition.

[Silicone oil (E)]
The encapsulating resin composition of the present embodiment can contain a silicone oil (E) as a stress reducing agent, which can suppress warping of a molded article obtained by encapsulating an electronic element or the like with the encapsulating resin composition.

The silicone oil (E) preferably contains an organic modified silicone oil such as an epoxy modified silicone oil, a carboxyl modified silicone oil, an alkyl modified silicone oil, or a polyether modified silicone oil. Among these, it is particularly preferable to contain a polyether modified silicone oil from the viewpoint of finely dispersing the silicone oil (E) in the resin component and contributing to suppression of warping.

The content of silicone oil (E) is preferably 0.01% by mass or more, more preferably 0.05% by mass or more based on the entire sealing resin composition. Further, the content of silicone oil (E) is preferably 1% by mass or less, more preferably 0.5% by mass or less, based on the entire sealing resin composition. By controlling the content of silicone oil (E) within such a range, it is possible to contribute to suppressing warping of a molded article obtained by sealing an electronic device or the like with the sealing resin composition.

In this embodiment, other low stress agents besides silicone oil (E) may be included, and specific examples include silicones such as silicone rubber, silicone elastomer, and silicone resin; acrylonitrile butadiene rubber, etc.

[Inorganic filler (F)]
The sealing resin composition of this embodiment can contain an inorganic filler (F).
As the inorganic filler (F), those commonly used in resin compositions for semiconductor encapsulation can be used. Moreover, the inorganic filler (F) may be surface-treated.

Specific examples of the inorganic filler (F) include silica such as fused silica, crystalline silica, and amorphous silicon dioxide; alumina; talc; titanium oxide; silicon nitride; and aluminum nitride. These inorganic fillers may be used alone or in combination of two or more.

From the viewpoint of excellent versatility, the inorganic filler (F) preferably contains silica. Examples of the shape of the silica include spherical silica and crushed silica.

The average diameter (D ₅₀ ) of the inorganic filler (F) is preferably 5 μm or more, more preferably 10 μm or more, and preferably 80 μm or less, from the viewpoint of improving moldability and adhesion. More preferably, it is 50 μm or less, and still more preferably 40 μm or less.
Here, the particle size distribution of the inorganic filler (F) can be determined by measuring the particle size distribution of particles on a volume basis using a commercially available laser diffraction particle size distribution analyzer (for example, SALD-7000 manufactured by Shimadzu Corporation). It can be obtained by

In addition, the maximum particle size of the inorganic filler (F) is preferably 10 μm or more, more preferably 20 μm or more, and preferably 100 μm or less, and more preferably from the viewpoint of improving moldability and adhesion. Preferably it is 80 μm or less.

Further, the specific surface area of the inorganic filler (F) is preferably 1 m ² /g or more, more preferably 3 m 2 /g or more, and preferably 20 m ² /g or more from the viewpoint of improving moldability and adhesion. ² /g or less, more preferably 10 m ² /g or less.

The content of the inorganic filler (F) in the encapsulating resin composition improves the low hygroscopicity and low thermal expansion of the encapsulating material formed using the encapsulating resin composition, and improves the resulting semiconductor device. From the viewpoint of more effectively improving the moisture resistance reliability and reflow resistance of the resin composition, it is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 65% by mass, based on the entire sealing resin composition. % by mass or more.
In addition, from the viewpoint of more effectively improving the fluidity and filling properties during molding of the encapsulating resin composition, the content of the inorganic filler (F) in the encapsulating resin composition The amount may be, for example, 97% by mass or less, preferably 95% by mass or less, and more preferably 90% by mass or less, based on the entire composition.

[Other ingredients]
The sealing resin composition of the present embodiment may contain components other than those described above, such as various additives such as a fluidity imparting agent, a mold release agent, an ion trapping agent, a flame retardant, a coloring agent, and an antioxidant. One or more of these agents can be blended as appropriate. In addition, the sealing resin composition may include, for example, 2-hydroxy-N-1H-1,2,4-triazol-3-ylbenzamide and 3-amino-5-mercapto-1,2,4-triazole. It may further include one or more.

Mold release agents include, for example, natural waxes such as carnauba wax; synthetic waxes such as montanic acid ester wax and oxidized polyethylene wax; higher fatty acids and their metal salts such as zinc stearate; paraffin; and carboxylic acid amides such as erucic acid amide. One type or two or more types selected from the group consisting of:
The content of the mold release agent in the encapsulation resin composition is preferably 0.00% relative to the entire encapsulation resin composition from the viewpoint of improving the mold releasability of the cured product of the encapsulation resin composition. 01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and preferably 2.0% by mass or less, more preferably 1.0% by mass. The content is preferably 0.5% by mass or less.

A specific example of the ion scavenger is hydrotalcite.
The content of the ion scavenger in the sealing resin composition is preferably 0.01% by mass or more based on the entire sealing resin composition, from the viewpoint of improving the reliability of the sealing material. It is more preferably 0.05% by mass or more, more preferably 1.0% by mass or less, and even more preferably 0.5% by mass or less.

Specific examples of flame retardants include aluminum hydroxide, magnesium hydroxide, zinc borate, zinc molybdate, and phosphazene.
The content of the flame retardant in the encapsulating resin composition is preferably 1% by mass or more, more preferably 1% by mass or more based on the entire encapsulating resin composition, from the viewpoint of improving the flame retardance of the encapsulating material. is 5% by mass or more, preferably 20% by mass or less, and more preferably 10% by mass or less.

Specific examples of colorants include carbon black and red iron oxide.
From the viewpoint of obtaining a preferable color tone of the encapsulating material, the content of the colorant in the encapsulating resin composition is preferably 0.1 mass % or more, more preferably 0.2 mass % or more, and is preferably 2 mass % or less, more preferably 1 mass % or less, based on the entire encapsulating resin composition.

Specific examples of antioxidants include hindered phenol compounds, hindered amine compounds, and thioether compounds.

<Sealing resin composition>
The encapsulating resin composition of this embodiment is solid at room temperature (25°C), and its shape can be selected depending on the molding method of the encapsulating resin composition, such as tablet form; powder form. , particulate forms such as granules; and sheet forms.

In addition, regarding the method for producing the resin composition for sealing, for example, the above-mentioned components are mixed by known means, further melt-kneaded using a kneading machine such as a roll, kneader, or extruder, cooled, and then pulverized. It can be obtained by a method. Further, after pulverization, the resin composition for sealing may be molded to obtain a particulate or sheet-like sealing resin composition. For example, a particulate sealing resin composition may be obtained by compression molding into a tablet shape. Alternatively, a sheet-shaped sealing resin composition may be obtained using, for example, a vacuum extruder. Further, the degree of dispersion, fluidity, etc. of the obtained sealing resin composition may be adjusted as appropriate.
In addition, when the melting point of the active ester resin (B2) is high, it is preferable to melt-mix the phenol resin (B1) and the active ester resin (B2) in advance to uniformly mix them.

The encapsulating resin composition obtained in this embodiment contains the phenol resin (B1) and the active ester resin (B2) as the curing agent (B), and therefore can give a cured product having a low shrinkage rate, excellent product yield, and excellent mechanical strength and dielectric properties.
The encapsulating resin composition of the present embodiment can be used for transfer molding, injection molding, or compression molding.
Furthermore, by using the encapsulating resin composition obtained in this embodiment, a semiconductor device with excellent product reliability can be obtained.

Next, the physical properties of the encapsulating resin composition or the cured product thereof will be described.
The gel time of the encapsulating resin composition of the present embodiment is preferably 50 seconds or more and 80 seconds or less, and more preferably 55 seconds or more and 70 seconds or less.
By setting the gel time of the encapsulating resin composition to be equal to or greater than the above lower limit, a package having excellent filling properties can be obtained, whereas by setting the gel time of the encapsulating resin composition to be equal to or less than the above upper limit, good moldability can be obtained.

The cured product obtained from the sealing resin composition of this embodiment has high bending strength and has a smaller increase in bending elastic modulus than conventional cured products, so it can provide sealing with excellent mechanical strength and product reliability. material can be provided.
When the sealing resin composition of this embodiment is cured at 175°C for 120 seconds, the flexural modulus of the cured product at room temperature (25°C) is 15,000 MPa or more, preferably 16,000 MPa or more. , more preferably 17,000 MPa or more. The upper limit is not particularly limited, but may be 30,000 MPa or less.

When the encapsulating resin composition of this embodiment is cured at 175°C for 120 seconds, the cured product has a bending strength at room temperature (25°C) of 60 MPa or more, preferably 80 MPa or more, and more preferably 100 MPa or more. The upper limit is not particularly limited, but can be 200 MPa or less.

In this embodiment, the upper limit of the molding shrinkage rate of the sealing resin composition is preferably 0.14% or less, more preferably 0.13% or less, and 0.12% or less. It is particularly preferable. By keeping the upper limit of the molding shrinkage rate low, warping of the molded article can be suppressed. On the other hand, the lower limit of the molding shrinkage rate of the encapsulating resin composition is preferably -0.5% or more, and more preferably -0.3% or more, for example. By setting the molding shrinkage rate within the above range, the molded article can be demolded more easily. The above-mentioned molding shrinkage rate is measured using, for example, a sealing resin composition using a low-pressure transfer molding machine (KTS-15 manufactured by Kotaki Seiki Co., Ltd.) at a mold temperature of 175°C, an injection pressure of 6.9 MPa, and curing. The test can be performed according to JIS K 6911 on a test piece prepared under the conditions of 120 seconds.

The dielectric constant of the cured product of this embodiment at a frequency of 5 GHz can be 4.0 or less, preferably 3.8 or less, and more preferably 3.6 or less. This allows the cured product to be used as a low dielectric constant material.

The cured product of this embodiment has a dielectric loss tangent (tan δ) of 0.007 or less, preferably 0.006 or less, and more preferably 0.005 or less, when measured at a frequency of 5 GHz. This can further improve the dielectric properties of the cured product.

In this embodiment, the physical properties of the encapsulating resin composition and the cured product can be controlled by appropriately selecting the type and amount of each component contained in the encapsulating resin composition, the preparation method of the encapsulating resin composition, etc.

<Semiconductor Device>
The semiconductor device in this embodiment is a semiconductor element encapsulated with the cured product of the encapsulating resin composition in this embodiment. Specific examples of the semiconductor element include integrated circuits, large-scale integrated circuits, transistors, thyristors, diodes, solid-state imaging elements, etc. The semiconductor element is preferably an element that does not involve light input or output, excluding optical semiconductor elements such as light receiving elements and light emitting elements (light emitting diodes, etc.).

The substrate of the semiconductor device is, for example, a wiring board such as an interposer, or a lead frame. The semiconductor element is electrically connected to the substrate by wire bonding or flip chip connection.

Examples of semiconductor devices obtained by sealing a semiconductor element by sealing molding using a sealing resin composition include MAP (Mold Array Package), QFP (Quad Flat Package), SOP (Small Outline Package), CSP (Chip Size Package), QFN (Quad Flat Non-leaded Package), SON (Small Outline Non-leaded Package), BGA (Ball Grid Array), LF-BGA (Lead Flame BGA), FCBGA (Flip Chip BGA), Examples include MAPBGA (Molded Array Process BGA), eWLB (Embedded Wafer-Level BGA), Fan-In type eWLB, and Fan-Out type eWLB.
A more specific explanation will be given below with reference to the drawings.

1 and 2 are both cross-sectional views showing the structure of a semiconductor device. Note that in this embodiment, the configuration of the semiconductor device is not limited to that shown in FIGS. 1 and 2.
First, the semiconductor device 100 shown in FIG. 1 includes a semiconductor element 20 mounted on a substrate 30 and a sealing material 50 that seals the semiconductor element 20.
The sealing material 50 is made of a cured product obtained by curing the sealing resin composition in this embodiment described above.

1 also illustrates a case where the substrate 30 is a circuit board. In this case, as shown in FIG. 1, a plurality of solder balls 60 are formed on the other side of the substrate 30 opposite to the side on which the semiconductor element 20 is mounted. The semiconductor element 20 is mounted on the substrate 30 and electrically connected to the substrate 30 via the wire 40. On the other hand, the semiconductor element 20 may be flip-chip mounted on the substrate 30. Here, the wire 40 is not limited to, but may be, for example, an Ag wire, a Ni wire, a Cu wire, an Au wire, or an Al wire, and preferably, the wire 40 is made of Ag, Ni, or Cu, or an alloy containing one or more of these.

The sealing material 50 seals the semiconductor element 20, for example, so as to cover the other surface of the semiconductor element 20 opposite to the surface facing the substrate 30. In the example shown in FIG. 1 , the sealing material 50 is formed so as to cover the other surface and the side surface of the semiconductor element 20.
In the present embodiment, the encapsulant 50 is made of a cured product of the above-mentioned encapsulating resin composition. Therefore, in the semiconductor device 100, the encapsulant 50 and the wires 40 have excellent adhesion, and therefore the semiconductor device 100 has excellent reliability.
The encapsulant 50 can be formed, for example, by encapsulating and molding an encapsulating resin composition using a known method such as transfer molding or compression molding.

Figure 2 is a cross-sectional view showing the configuration of a semiconductor device 100 in this embodiment, and shows an example different from that in Figure 1. The semiconductor device 100 shown in Figure 2 uses a lead frame as the substrate 30. In this case, the semiconductor element 20 is mounted, for example, on a die pad 32 of the substrate 30, and is electrically connected to an outer lead 34 via a wire 40. The encapsulant 50 is composed of a cured product of the encapsulating resin composition in this embodiment, similar to the example shown in Figure 1.

The above describes embodiments of the present invention, but these are merely examples of the present invention and various configurations other than those described above can also be adopted.

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto.

<Examples 1 to 12 and Comparative Examples 1 to 3 (Production of Encapsulating Resin Composition)>
The components shown in Tables 1 and 2 were mixed in the amounts shown in the tables to obtain mixtures. The mixing was carried out at room temperature using a Henschel mixer.
The mixture was then roll-kneaded at 70 to 100° C. to obtain a kneaded product. The kneaded product was cooled and then pulverized to obtain an encapsulating resin composition. The components shown in Tables 1 and 2 are as follows.

(Inorganic filler)
Inorganic filler 1: Silica (manufactured by Micron, product name: TS-6026, average diameter 9 μm)
Inorganic filler 2: fine silica (manufactured by Admatechs, product name: SC-2500-SQ, average diameter 0.6 μm)
Inorganic filler 3: fine silica (manufactured by Admatechs, product name: SC-5500-SQ, average diameter 1.6 μm)

(Flame retardants)
Flame retardant 1: Aluminum hydroxide (manufactured by Nippon Light Metals Co., Ltd., Dp 5 μm)

(coupling agent)
- Silane coupling agent 1: N-phenylaminopropyltrimethoxysilane (manufactured by Dow Corning Toray, CF-4083)
・Silane coupling agent 2: 3-mercaptopropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM803P)
- Silane coupling agent 3: 3-glycidoxypropylmethyldimethoxysilane (manufactured by Dow Corning Toray, AZ-6137)

(Epoxy resin)
Epoxy resin 1: biphenyl aralkyl type epoxy resin (manufactured by Nippon Kayaku Co., Ltd., NC-3000L, epoxy equivalent 273 g/eq)
Epoxy resin 2: Dicyclopentadiene skeleton-containing polyfunctional solid epoxy resin (DIC Corporation, Epicron HP-7200L, epoxy equivalent 246 g/eq)

(hardening agent)
・Phenol resin: Biphenylene skeleton-containing phenol aralkyl type resin (manufactured by Meiwa Kasei Co., Ltd., MEH-7851SS, hydroxyl group equivalent 200 g/eq)
・Active ester resin 1: Active ester resin prepared by the following preparation method (Preparation method of active ester resin 1)
In a flask equipped with a thermometer, dropping funnel, condenser tube, fractionator tube, and stirrer, add 279.1 g of biphenyl-4,4'-dicarboxylic acid dichloride (number of moles of acid chloride group: 2.0 moles) and 1338 g of toluene. were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Next, 96.5 g (0.67 mol) of α-naphthol and 219.5 g (mol number of phenolic hydroxyl group: 1.33 mol) of dicyclopentadiene phenol resin were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Ta. Thereafter, while performing a nitrogen gas purge, the inside of the system was controlled at 60° C. or lower, and 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over a period of 3 hours. Stirring was then continued under these conditions for 1.0 hour. After the reaction was completed, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Furthermore, water was added to the toluene phase in which the reactants were dissolved, and the mixture was stirred and mixed for about 15 minutes, and the mixture was allowed to stand still for liquid separation to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water was removed by dehydration using a decanter to obtain active ester resin 1 in the form of a toluene solution with a nonvolatile content of 65%. When the structure of the obtained active ester resin 1 was confirmed, it had a structure in which R ¹ and R ³ are hydrogen atoms, Z is a naphthyl group, and l is 0 in the above formula (1-1). The average value k of the repeating units of active ester resin 1 was calculated from the reaction equivalence ratio and was in the range of 0.5 to 1.0. Moreover, the active group equivalent was 247 g/eq.

Active ester resin 2: Active ester resin prepared by the following preparation method (Preparation method of active ester resin 2)
In a flask equipped with a thermometer, a dropping funnel, a cooling tube, a fractionating tube, and a stirrer, 203.0 g of 1,3-benzenedicarboxylic acid dichloride (molar number of acid chloride groups: 2.0 mol) and 1338 g of toluene were charged, and the inside of the system was substituted with nitrogen under reduced pressure to dissolve. Next, 96.5 g (0.67 mol) of α-naphthol and 219.5 g of dicyclopentadiene phenol resin (molar number of phenolic hydroxyl groups: 1.33 mol) were charged, and the inside of the system was substituted with nitrogen under reduced pressure to dissolve. Thereafter, while applying nitrogen gas purging, the inside of the system was controlled to 60°C or less, and 400 g of 20% aqueous sodium hydroxide solution was dropped over 3 hours. Then, stirring was continued under these conditions for 1.0 hour. After the reaction was completed, the mixture was left to stand and separated, and the aqueous layer was removed. Furthermore, water was added to the toluene phase in which the reactants were dissolved, and the mixture was stirred and mixed for about 15 minutes, and the mixture was left to stand and separated to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water was removed by decanting to obtain active ester resin 2 in a toluene solution state with a non-volatile content of 65%. When the structure of the obtained active ester resin was confirmed, it had a structure in which R ¹ and R ³ were hydrogen atoms, Z was a naphthyl group, and l was 0 in the above formula (1-3). The average value k of the repeating units of active ester resin 2 was calculated from the reaction equivalent ratio and was in the range of 0.5 to 1.0. Specifically, the obtained active ester resin 2 had a structure represented by the following chemical formula. In addition, the active group equivalent was 209 g/eq.

(hardening accelerator)
・Curing accelerator 1: Tetraphenylphosphonium 4,4'-sulfonyldiphenolate ・Curing accelerator 2: Tetraphenylphosphonium bis(naphthalene-2,3-dioxy)phenyl silicate ・Curing accelerator 3: 4-hydroxy-2 -(triphenylphosphonium)phenolate

(Ion Scavenger)
Ion scavenger 1: Magnesium aluminum hydroxide carbonate hydrate (Kyowa Chemical Industry Co., Ltd., DHT-4H)

(Wax (release agent))
Wax 1: Oxidized polyethylene wax (Licowax PED191, manufactured by Clariant Japan)
Wax 2: Carnauba wax (TOWAX-132, manufactured by Toa Gosei Co., Ltd.)

(Coloring Agent)
Carbon black: ERS-2001 (manufactured by Tokai Carbon Co., Ltd.)

(Low stress agent)
・Low stress agent 1: Carboxyl group-terminated butadiene/acrylonitrile copolymer (manufactured by Ube Industries, Ltd., CTBN1008SP)
・Low stress agent 2: Epoxy/polyether modified silicone oil (manufactured by Dow Corning Toray, FZ-3730)

<Evaluation>
Evaluation samples were prepared using the resin compositions obtained in each example or the compositions in the following manner, and the adhesion and reliability of the obtained samples were evaluated by the following methods.
[Spiral flow (SF)]
A spiral flow test was conducted using the sealing resin compositions of Examples and Comparative Examples.
The test was conducted using a low-pressure transfer molding machine (KTS-15 manufactured by Kotaki Seiki Co., Ltd.) at a mold temperature of 175°C and an injection pressure of 6. The sealing resin composition was injected under the conditions of .9 MPa and curing time of 120 seconds, and the flow length was measured. The larger the value, the better the fluidity.

[Gel time (GT)]
Each of the encapsulating resin compositions of the Examples and Comparative Examples was melted on a hot plate heated to 175° C., and then the time (unit: seconds) until the composition hardened was measured while kneading the composition with a spatula.

(Glass transition temperature, coefficient of linear expansion (α ₁ and α ₂ ),)
It was measured using the following procedure.
(1) Using a transfer molding machine, the sealing resin composition was injection molded under the conditions of a mold temperature of 175°C, an injection pressure of 10.0 MPa, and a curing time of 120 seconds to obtain a molded product of 15 mm x 4 mm x 3 mm. Ta.
(2) The obtained molded product was heated in an oven at 175° C. for 4 hours to fully cure it. Then, a test piece (cured product) for measurement was obtained.
(3) Measurement was performed using a thermomechanical analyzer (TMA100, manufactured by Seiko Electronics Industries, Ltd.) under conditions of a measurement temperature range of 0° C. to 320° C. and a heating rate of 5° C./min. From the measurement results, the glass transition temperature Tg (°C), the linear expansion coefficient (α ₁ ) at 40 to 80°C, and the linear expansion coefficient (α ₂ ) at 190 to 230°C were calculated. The unit of α ₁ and α ₂ is ppm/°C, and the unit of glass transition temperature is °C.

[Evaluation of mechanical strength (flexural strength and flexural modulus)]
The encapsulating resin composition was injected into a mold using a low-pressure transfer molding machine ("KTS-30" manufactured by Kotaki Seiki Co., Ltd.) under conditions of a mold temperature of 175°C, an injection pressure of 10.0 MPa, and a curing time of 120 seconds. This resulted in a molded product having a width of 10 mm, a thickness of 4 mm, and a length of 80 mm. The molded product thus obtained was then post-cured at 175°C for 4 hours. This resulted in a test piece for evaluation of mechanical strength. The flexural strength (MPa) and flexural modulus (MPa) of the test piece at 260°C or room temperature (25°C) were measured in accordance with JIS K 6911.

(boiling water absorption rate)
For each Example and Comparative Example, the boiling water absorption rate of the cured product of the obtained sealing resin composition was measured as follows. First, a disk-shaped test with a diameter of 50 mm and a thickness of 3 mm was performed using a low-pressure transfer molding machine (KTS-15 manufactured by Kotaki Seiki Co., Ltd.) at a mold temperature of 175°C, an injection pressure of 6.9 MPa, and a curing time of 120 seconds. The pieces were shaped. Next, the obtained test piece was post-cured at 175° C. for 4 hours, and then the mass of this test piece before boiling treatment and after boiling treatment in pure water for 24 hours were measured. Based on the measurement results, the mass change before and after the boiling treatment was calculated, and the boiling water absorption rate of the test piece was obtained as a percentage. The unit in Table 1 is mass %.

(Molding shrinkage rate)
For each of the Examples and Comparative Examples, the mold shrinkage rate (after ASM) of the obtained resin composition after molding (ASM: as mold) was measured, and the mold shrinkage rate (after PMC) was evaluated under heating conditions (PMC: post mold cure) assuming that the composition is fully cured after molding to produce a dielectric substrate.
First, a test piece was prepared using a low-pressure transfer molding machine (KTS-15, manufactured by Kotaki Seiki Co., Ltd.) under conditions of a mold temperature of 175°C, an injection pressure of 6.9 MPa, and a curing time of 120 seconds, and the mold shrinkage rate (after ASM) was obtained in accordance with JIS K 6911.
Furthermore, the obtained test pieces were heat-treated at 175° C. for 4 hours, and the molding shrinkage rate (after ASM) was measured in accordance with JIS K 6911.

(Evaluation of dielectric constant and dielectric loss tangent using the cavity resonator method)
First, a test piece was obtained using the resin composition.
Specifically, the resin compositions prepared in the examples and comparative examples were applied to a Si substrate and prebaked at 120° C. for 4 minutes to form a resin film having a coating thickness of 12 μm.
This was heated in an oven at 200° C. for 90 minutes in a nitrogen atmosphere, and then subjected to a hydrofluoric acid treatment (immersed in a 2% by mass aqueous hydrofluoric acid solution). After removing the substrate from the hydrofluoric acid, the cured film was peeled off from the Si substrate, and this was used as a test piece.
The measurement devices used were a network analyzer HP8510C, a synthesized sweeper HP83651A, and a test set HP8517B (all manufactured by Agilent Technologies). These devices and a cylindrical cavity resonator (inner diameter φ42 mm, height 30 mm) were set up.
The resonant frequency, 3 dB bandwidth, and transmitted power ratio were measured at a frequency of 5 GHz when the test piece was inserted in the resonator and when it was not inserted. The dielectric properties of the dielectric constant (Dk) and dielectric loss tangent (Df) were calculated analytically using software. The measurement mode was TE ₀₁₁ mode.

As shown in Tables 1 and 2, by using a resin composition for semiconductor encapsulation that uses a combination of a phenolic resin and an active ester resin as a curing agent and further contains a specified curing accelerator, it is expected that the shrinkage rate during molding will be low and the product yield will be excellent. Furthermore, it has been confirmed that the cured product obtained from the composition has excellent mechanical strength and dielectric properties. In other words, it has been confirmed that the resin composition for semiconductor encapsulation of the present invention has an excellent balance of these properties.

This application claims priority based on Japanese Patent Application No. 2021-117662, filed on July 16, 2021, the disclosure of which is incorporated herein in its entirety.

20 Semiconductor element 30 Substrate 32 Die pad 34 Outer lead 40 Wire 50 Sealing material 60 Solder ball 100 Semiconductor device

Claims (16)

(A) an epoxy resin;
(B) a curing agent; and
(C) a curing accelerator,
The curing agent (B) contains a phenol resin (B1) and an active ester resin (B2),
The phenol resin (B1) has a biphenylaralkyl structure,
The active ester resin (B2) has a structure represented by general formula (1):

In the general formula (1), A is a substituted or unsubstituted arylene group linked via an aliphatic cyclic hydrocarbon group,
Ar' is a substituted or unsubstituted aryl group;
k is the average value of the repeating units, ranging from 0.25 to 3.5;
In general formula (1), B is a structure represented by general formula (B),

(In general formula (B), Ar is a substituted or unsubstituted arylene group, Y is a single bond, a substituted or unsubstituted linear alkylene group having 1 to 6 carbon atoms , a substituted or unsubstituted cyclic alkylene group having 3 to 6 carbon atoms, a substituted or unsubstituted divalent aromatic hydrocarbon group, an ether bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group. n is an integer of 0 to 4.)
The curing accelerator (C) includes one or more selected from the group consisting of tetraphenylphosphonium-4,4'-sulfonyldiphenolate, tetraphenylphosphonium bis(naphthalene-2,3-dioxy)phenylsilicate, and 4-hydroxy-2-(triphenylphosphonium)phenolate ;
the equivalent ratio ((B)/(A)) of the curing agent (B) to the epoxy resin (A) is 0.60 to 0.90;
the equivalent ratio ((B1)/(A)) of the phenolic resin (B1) to the epoxy resin (A) is 0.10 to 0.55;
A resin composition for semiconductor encapsulation , in which the equivalent ratio ((B2)/(A)) of the active ester resin (B2) to the epoxy resin (A) is 0.10 to 0.60. The equivalent ratio ((B)/(A)) of the curing agent (B) to the epoxy resin (A) is 0.60 to 0.80,
The equivalent ratio ((B1)/(A)) of the phenolic resin (B1) to the epoxy resin (A) is 0.20 to 0.55,
The resin composition for semiconductor encapsulation according to claim 1, wherein the equivalent ratio ((B2)/(A)) of the active ester resin (B2) to the epoxy resin (A) is 0.17 to 0.45. The semiconductor encapsulation resin composition according to claim 1,
The structure represented by the general formula (B) is at least one selected from general formulas (B-1) to (B-6).

(In general formulas (B-1) to (B-6), R ¹ 's each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group; R ² 's each independently represent an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group; X's each independently represent a linear alkylene group having 2 to 6 carbon atoms, an ether bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group;
n is an integer from 0 to 4, and p is an integer from 1 to 4. The resin composition for semiconductor encapsulation according to claim 1,
A resin composition for semiconductor encapsulation, wherein in the general formula (1), A has a structure represented by the general formula (A).

(In the general formula (A), R ³ is each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group, and l is 0 or 1, m is an integer greater than or equal to 1) The semiconductor encapsulation resin composition according to claim 1,
A resin composition for semiconductor encapsulation, wherein the ratio of the content (parts by weight) of the phenol resin (B1) to the content (parts by weight) of the active ester resin (B2) is 25:75 to 75:25. The resin composition for semiconductor encapsulation according to claim 1,
The curing accelerator (C) is
(C1) a combination of tetraphenylphosphonium-4,4'-sulfonyldiphenolate and tetraphenylphosphonium bis(naphthalene-2,3-dioxy)phenyl silicate, or (C2) tetraphenylphosphonium bis(naphthalene-2, a combination of 3-dioxy)phenyl silicate and 4-hydroxy-2-(triphenylphosphonium)phenolate,
A resin composition for semiconductor encapsulation. The semiconductor encapsulation resin composition according to claim 1,
A resin composition for semiconductor encapsulation, comprising a curing accelerator (C) in an amount of 0.01% by mass or more and 2.0% by mass or less based on the entire resin composition for semiconductor encapsulation. The semiconductor encapsulation resin composition according to claim 1,
The resin composition for semiconductor encapsulation further comprises a coupling agent (D). The resin composition for semiconductor encapsulation according to claim 8 ,
A resin composition for semiconductor encapsulation, wherein the coupling agent (D) is a secondary aminosilane coupling agent. The semiconductor encapsulation resin composition according to claim 1 , wherein the epoxy resin (A) has a biphenylaralkyl structure. The resin composition for semiconductor encapsulation according to claim 1,
A resin composition for semiconductor encapsulation, wherein the epoxy resin (A) contains at least one selected from biphenylaralkyl type resins and dicyclopentadiene type resins. The resin composition for semiconductor encapsulation according to claim 1,
A resin composition for semiconductor encapsulation, further comprising silicone oil (E). The semiconductor encapsulation resin composition according to claim 1,
The resin composition for semiconductor encapsulation further comprises an inorganic filler (F). The resin composition for semiconductor encapsulation according to claim 13 ,
A resin composition for semiconductor encapsulation, wherein the inorganic filler (F) is at least one selected from silica, alumina, talc, titanium oxide, silicon nitride, and aluminum nitride. The resin composition for semiconductor encapsulation according to claim 1,
A resin composition for semiconductor encapsulation whose gel time measured under the following conditions is 50 seconds or more and 80 seconds or less.
(conditions)
After melting the resin composition for semiconductor encapsulation on a hot plate heated to 175° C., the time (unit: seconds) until hardening is measured while kneading with a spatula, and this time is defined as gel time. A semiconductor element;
An encapsulant for encapsulating a semiconductor element, the encapsulant comprising a cured product of the semiconductor encapsulation resin composition according to any one of claims 1 to 15 ;
A semiconductor device comprising:

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