JP7217865B2 - Wafer level package encapsulation resin composition - Google Patents

Description

The present invention relates to a resin composition for sealing wafer level packages.

As electronic devices have become smaller and thinner in recent years, wafer level packages (WLP), which are advantageous in reducing the thickness of semiconductor packages, have attracted attention. A WLP is a semiconductor package that is sealed with a sealing resin in the state of a wafer (or pseudo-wafer). As WLP, a fan-in type WLP and a fan-out type WLP are known.

For example, in the fan-in type, a rewiring layer and the like are formed on a disk-shaped semiconductor substrate (wafer). In addition, sealing with a sealing resin is performed in a wafer state. After the encapsulation process, the wafer is diced to obtain a plurality of semiconductor packages.

On the other hand, in the fan-out type, a semiconductor wafer is diced in advance to obtain a plurality of semiconductor chips. The obtained plurality of semiconductor chips are arranged on a film-like carrier substrate (pseudo-wafer), for example, having the size of a wafer. Then, a sealing resin is supplied onto the carrier substrate so as to cover the plurality of semiconductor chips, and the plurality of semiconductor chips are collectively sealed. After that, the carrier substrate is separated from the integrated body of the semiconductor chip and the sealing resin. By peeling off the carrier substrate, the circuit forming surface of each semiconductor chip is exposed. A rewiring layer and the like are formed on the exposed circuit forming surface. After that, an integrated product of a plurality of semiconductor chips and sealing resin is cut into individual semiconductor chips. Thereby, a plurality of semiconductor packages are obtained.

In WLP, the sealing process proceeds in the state of a wafer (or pseudo-wafer). Therefore, it is required to form a thin sealing layer with a large area, and from this point of view, a sealing method by compression molding, which is advantageous, is being used. In the compression molding method, a thermosetting resin composition is supplied as a sealing resin onto a wafer or the like. Next, the resin composition is pressurized by a hot plate or the like, thereby spreading the resin composition and collectively forming a sealing layer.

In the WLP sealing process, since the area of the sealing layer is large, warpage of the wafer after sealing becomes a problem. As one means for suppressing warpage, increasing the content of inorganic filler in the encapsulating resin composition is known. However, increasing the content of the inorganic filler increases the viscosity of the resin composition and reduces the fluidity. As a result, the moldability at the time of compression molding deteriorates.

In order to solve such problems, Patent Document 1 discloses a specific content of epoxy resin, a specific content of acid anhydride, a specific microcapsule-type curing accelerator, and a specific fused spherical silica, Epoxy resin compositions for the manufacture of electronic components are disclosed.

International Publication No. 2009/142065

The inventors of the present application are considering using an epoxy resin composition using a thiol compound as a curing agent as a resin composition for encapsulating wafer level packages. A thiol compound has advantages over other curing agents, such as excellent low-temperature curability.
However, the epoxy resin composition using a thiol compound has a problem in reducing warpage.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a resin composition for encapsulating a wafer level package, which uses a thiol compound as a curing agent, yet has excellent fluidity and reduces substrate warpage.

式（３）乃至（５）において、Ｒ₁乃至Ｒ₁₁は、それぞれ独立に、炭素数１～６の直鎖もしくは分岐鎖の２価の炭化水素基を示し、
Ｒ₁乃至Ｒ₁₁における炭化水素基中には、さらに下記式（６）乃至（８）のいずれかに示される２価の基が、１つ以上含まれていてもよい、

［１］乃至［４］のいずれか１項に記載の樹脂組成物。
［７］前記チオール化合物が、トリス（３－メルカプトプロピル）イソシアヌレート、トリメチロールプロパントリス（３－メルカプトプロピオナート）（ＴＭＴＰ）、トリメチロールプロパントリス（チオグリコレート）、ペンタエリスリトールテトラキス（チオグリコレート）、エチレングリコールジチオグリコレート、ペンタエリスリトールテトラキス（β－チオプロピオネート）、及びジペンタエリスリトールポリ（β－チオプロピオネート）からなる群から選ばれる少なくとも一種の化合物を含む、［１］乃至［４］のいずれかに記載の樹脂組成物。
［８］前記無機充填材が、シリカを含む、［１］乃至［７］のいずれか１項に記載の樹脂組成物。
［９］前記シリカが、溶融シリカである、［８］に記載の樹脂組成物。
［１０］前記シリカが、真球状である、［８］又は［９］に記載の樹脂組成物。
［１１］無機充填材の含有量が、樹脂組成物の全不揮発分１００質量部に対し、３０～９５質量部である、［１］乃至［１０］のいずれか１項に記載の樹脂組成物。
［１２］更に、（Ｄ）潜在性硬化促進剤を含む、［１］乃至［１１］のいずれか１項に記載の樹脂組成物。
［１３］前記潜在性硬化促進剤が、固体分散型潜在性硬化促進剤を含む、［１２］に記載の樹脂組成物。
［１４］更に、（Ｅ）保存安定化剤を含む、［１］乃至［１３］のいずれか１項に記載の樹脂組成物。
［１５］前記保存安定化剤がボレート化合物、チタネート化合物、アルミネート化合物、ジルコネート化合物、イソシアネート化合物、カルボン酸、酸無水物及びメルカプト有機酸から選択される１以上を含む、［１４］に記載の樹脂組成物。
［１６］粘度が３００Ｐａ・Ｓ以下である、［１］乃至［１５］のいずれか１項に記載の樹脂組成物。
［１７］８０℃で３０分間加熱して得られた硬化物のガラス転移温度が、１００℃以下である、［１］乃至［１６］のいずれか１項に記載の樹脂組成物。
［１８］８０℃で３０分間加熱して得られた硬化物の２５℃の引張弾性率が、１００００ＭＰａ以下である、［１］乃至［１７］のいずれか１項に記載の樹脂組成物。
［１９］半導体基板と、前記半導体基板を封止する封止層とを備え、前記封止層が、［１］乃至［１８］のいずれか１項に記載の樹脂組成物の硬化物により形成されている、ウエハーレベルパッケージ。
［２０］基板上に、［１］～［１８］のいずれか１項に記載の樹脂組成物を供給する工程と、前記供給された樹脂組成物を、コンプレッション成形によって成形する工程とを備える、ウエハーレベルパッケージの製造方法。 In order to solve the above problems, the present invention includes the following items.
[1] (A1) a first epoxy resin that is liquid at 25° C. and has an epoxy equivalent of 250 to 1000; (A2) a second epoxy resin that has an epoxy equivalent lower than that of the first epoxy resin; ) A thiol compound having two or more thiol groups in the molecule, and (C) an inorganic filler.
[2] The resin composition according to [1], wherein the (A1) first epoxy resin has a viscosity of 20 Pa·S or less at 25°C.
[3] The resin composition according to [1] or [2], wherein the second epoxy resin (A2) has an epoxy equivalent of 80 or more and less than 250.
[4] Any one of [1] to [3], wherein the mass ratio (A1:A2) of the (A1) first epoxy resin and the (A2) second epoxy resin is 10:1 to 1:10 1. The resin composition according to claim 1.
[5] The resin composition according to any one of [1] to [4], wherein the thiol compound contains an ester-free thiol.
[6] The thiol compound contains at least one compound represented by any one of the following formulas (3) to (5),

In formulas (3) to (5), R ₁ to R ₁₁ each independently represent a linear or branched divalent hydrocarbon group having 1 to 6 carbon atoms,
The hydrocarbon groups represented by R ₁ to R ₁₁ may further contain one or more divalent groups represented by any of the following formulas (6) to (8).

The resin composition according to any one of [1] to [4].
[7] The thiol compound is tris(3-mercaptopropyl) isocyanurate, trimethylolpropane tris(3-mercaptopropionate) (TMTP), trimethylolpropane tris(thioglycolate), pentaerythritol tetrakis(thioglyco rate), ethylene glycol dithioglycolate, pentaerythritol tetrakis(β-thiopropionate), and dipentaerythritol poly(β-thiopropionate), [1] The resin composition according to any one of [4].
[8] The resin composition according to any one of [1] to [7], wherein the inorganic filler contains silica.
[9] The resin composition according to [8], wherein the silica is fused silica.
[10] The resin composition according to [8] or [9], wherein the silica is spherical.
[11] The resin composition according to any one of [1] to [10], wherein the content of the inorganic filler is 30 to 95 parts by mass with respect to 100 parts by mass of the total nonvolatile matter of the resin composition. .
[12] The resin composition according to any one of [1] to [11], further comprising (D) a latent curing accelerator.
[13] The resin composition according to [12], wherein the latent curing accelerator comprises a solid dispersion type latent curing accelerator.
[14] The resin composition according to any one of [1] to [13], further comprising (E) a storage stabilizer.
[15] The storage stabilizer according to [14], wherein the storage stabilizer contains one or more selected from borate compounds, titanate compounds, aluminate compounds, zirconate compounds, isocyanate compounds, carboxylic acids, acid anhydrides and mercapto organic acids. Resin composition.
[16] The resin composition according to any one of [1] to [15], which has a viscosity of 300 Pa·S or less.
[17] The resin composition according to any one of [1] to [16], wherein the cured product obtained by heating at 80°C for 30 minutes has a glass transition temperature of 100°C or lower.
[18] The resin composition according to any one of [1] to [17], wherein the cured product obtained by heating at 80°C for 30 minutes has a tensile modulus at 25°C of 10,000 MPa or less.
[19] A semiconductor substrate and a sealing layer for sealing the semiconductor substrate, wherein the sealing layer is formed from a cured product of the resin composition according to any one of [1] to [18]. Wafer level package.
[20] A step of supplying the resin composition according to any one of [1] to [18] onto a substrate, and molding the supplied resin composition by compression molding. A method for manufacturing a wafer level package.

ADVANTAGE OF THE INVENTION According to this invention, the resin composition for wafer level package sealing which the curvature of the board|substrate after sealing reduces is provided.

The resin composition for encapsulating a wafer level package according to an embodiment of the present invention comprises (A1) a first epoxy resin having a specific epoxy equivalent, (A2) a second epoxy resin having an epoxy equivalent lower than that of the first epoxy resin, It contains (B) a thiol compound having two or more thiol groups in the molecule, and (C) an inorganic filler. According to this embodiment, by using a combination of the first epoxy resin, the second epoxy resin, the thiol compound, and the inorganic filler, there is provided a resin composition for wafer level package encapsulation that can reduce warpage after encapsulation. provided.

[Wafer level package encapsulation resin composition]
The resin composition according to this embodiment is used as a sealing resin in wafer level packages. A wafer level package is a semiconductor package that is sealed with a sealing resin in the state of a wafer (or a pseudo-wafer), as described above. In the manufacturing process of the wafer level package, a substrate (semiconductor wafer) including a portion to become a plurality of semiconductor chips or a substrate (carrier substrate) on which a plurality of semiconductor chips are mounted is collectively sealed. After the encapsulation process, the substrate is diced corresponding to a plurality of semiconductor chips to obtain a plurality of wafer level packages. Therefore, the wafer level package can also be regarded as a semiconductor package obtained by a method in which materials are collectively sealed before the final dicing process.
As described above, the fan-in type and the fan-out type are known as wafer level packages. The resin composition for sealing a wafer level package according to this embodiment can be used as a sealing resin for both fan-in type and fan-out type.

The resin composition according to this embodiment is preferably used as a resin composition for compression molding. In the compression molding method, a sealing resin composition is supplied onto a substrate to be sealed. Next, the supplied resin is pressed against the substrate by a hot plate or the like. In the compression molding method, the resin composition is required to have a certain degree of fluidity in order to distribute the resin composition to every corner during pressurization. The resin composition according to the present embodiment has an appropriate degree of fluidity (viscosity) as a resin composition used in compression molding.

[(A1) first epoxy resin]
The first epoxy resin contained in the resin composition according to this embodiment is liquid at 25° C. and has an epoxy equivalent of 250 to 1,000.
Here, the epoxy equivalent is the mass of epoxy resin per epoxy group, and can be measured according to JIS K 7236 (2009).
The epoxy equivalent of the first epoxy resin is preferably 250 to 800, more preferably 250 to 700, still more preferably 250 to 650, still more preferably 250 to 600, still more preferably 300 to 600, still more preferably 400 to 600, Most preferably 400-500.

The content of the first epoxy resin in the resin composition is, for example, 3 to 50% by mass, preferably 5 to 40% by mass, more preferably 7 to 50% by mass, when the nonvolatile component of the resin composition is 100% by mass. 30% by mass, more preferably 10 to 25% by mass. Alternatively, the content of the first epoxy resin in the resin composition is 3 to 10% by mass when the non-volatile component of the resin composition is 100% by mass.

The first epoxy resin has a viscosity at 25° C. of 20 Pa·S or less, preferably 0.05 to 20 Pa·S, more preferably 0.1 to 18 Pa·S.
The molecular weight of the first epoxy resin is, for example, 300-3000, preferably 400-2500, more preferably 500-1500.

Examples of the first epoxy resin include bisphenol A type epoxy resin, polyalkylene type epoxy resin, and fluorene type epoxy resin. Examples of bisphenol A type resins include vinyl ether-modified bisphenol A type epoxy resins.

ここで、式（１）及び（２）中、Ｘ、Ｘ₁およびＸ₂は、互いに同一であっても異なっていてもよく、２以上の－（ＣＨ₂）－を含む非芳香族炭化水素基を主骨格に含む二価の基（ただし、Ｘが、－Ｏ－ＣＨ₂－ＣＨ（－ＯＨ）－ＣＨ₂－である場合を除く）である。
また、Ａｒ、Ａｒ₁及びＡｒ₂は、互いに同一であっても異なっていてもよく、二価の芳香族基を主骨格に含む二価の芳香族含有炭化水素基である。
ｎおよびｍは、それぞれ独立に１～２０の整数であり、好ましくは、１～１０の整数である。
式（１）中のｎ個のＸは、互いに同一であっても異なっていてもよい。
式（２）中のｍ個のＸ₁、ｍ個のＸ₂は、互いに同一であっても異なっていてもよい。
尚、式（１）及び（２）において、「主骨格」とは、両末端のエポキシ基を接続する骨格のうち、最も鎖の長い骨格を言う。 Suitable first epoxy resins include epoxy resins represented by the following formula (1) or (2).

Here, in formulas (1) and (2), X, X ₁ and X ₂ may be the same or different and are non-aromatic hydrocarbons containing two or more -(CH ₂ )- A divalent group containing a group in its main skeleton (except when X is --O--CH ₂ --CH(--OH)--CH ₂ --).
Ar, Ar ₁ and Ar ₂ , which may be the same or different, are divalent aromatic-containing hydrocarbon groups containing a divalent aromatic group in the main skeleton.
n and m are each independently an integer of 1-20, preferably an integer of 1-10.
n Xs in formula (1) may be the same or different.
m X ₁ and m X ₂ in formula (2) may be the same or different.
In the formulas (1) and (2), the term "main skeleton" refers to the skeleton with the longest chain among the skeletons connecting the epoxy groups at both ends.

_{( a} ) X, X1 and X2
Next, X, X ₁ and X ₂ in formulas (1) and (2) will be described in detail below. As described above, X, X ₁ and X ₂ are "a divalent group containing a non-aromatic hydrocarbon group containing two or more --(CH ₂ )-- in its main skeleton".

In X, X ₁ and X ₂ , the number of —(CH ₂ )— contained in the main skeleton is preferably 3 or more, more preferably 4 or more, even more preferably 5 to 30, most preferably 6 to is 20.
“Two or more —(CH ₂ )—” may be directly bonded, or an ether bond, an ester bond, an amide bond, two carbons bonded by a double bond, or two carbons bonded by a triple bond. It may be bonded via carbon or thioether bond.

Examples of X, X ₁ and X ₂ include an alkylene group and an alkyleneoxy group, which may or may not have a substituent.
Examples of substituents here include hydroxyl group, halogen atom, alkyl group, cycloalkyl group, alkoxy group, cycloalkyloxy group, amino group, silyl group, acyl group, acyloxy group, carboxy group, cyano group, nitro group, Groups selected from hydroxy groups, mercapto groups and oxo groups may be mentioned.

Halogen atoms used as substituents include, for example, fluorine, chlorine, bromine and iodine atoms.

Alkyl groups used as substituents may be linear or branched. The number of carbon atoms in the alkyl group is preferably 1-20, more preferably 1-14, even more preferably 1-12, even more preferably 1-6, and particularly preferably 1-3. Examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, sec-butyl group, isobutyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, octyl group and nonyl group. , and decyl groups. As described later, the alkyl group used as a substituent may further have a substituent (“secondary substituent”). Examples of alkyl groups having such secondary substituents include alkyl groups substituted with halogen atoms, specifically trifluoromethyl group, trichloromethyl group, tetrafluoroethyl group, tetrachloroethyl group and the like. are mentioned.

The cycloalkyl group used as a substituent preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms, and still more preferably 3 to 6 carbon atoms. Examples of the cycloalkyl group include cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group and the like.

Alkoxy groups used as substituents may be linear or branched. The number of carbon atoms in the alkoxy group is preferably 1-20, preferably 1-12, more preferably 1-6. Examples of the alkoxy group include methoxy, ethoxy, propyloxy, isopropyloxy, butoxy, sec-butoxy, isobutoxy, tert-butoxy, pentyloxy, hexyloxy, heptyloxy, Octyloxy, nonyloxy, and decyloxy groups are included.

The cycloalkyloxy group used as a substituent preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms, and still more preferably 3 to 6 carbon atoms. Examples of the cycloalkyloxy groups include cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, and cyclohexyloxy groups.

Amino groups used as substituents may be linear or branched, aliphatic, or aromatic. The number of carbon atoms in the amino group is preferably 1-20, preferably 1-12, more preferably 1-6. Examples of the amino group include aminomethyl group, aminoethyl group, aminopropyl group, isopropylamino group, aminobutoxy group, sec-butylamino group, isobutylamino group, tert-butylamino group, aminopentyl group and aminohexyl. group, aminoheptyl group, aminooctyl group, aminononyl group, aminodecyl group, aminophenyl group and the like.

A silyl group used as a substituent may be linear or branched. The number of carbon atoms in the silyl group is preferably 1-20, preferably 1-12, more preferably 1-6. Examples of the silyl group include methylsilyl group, ethylsilyl group, propylsilyl group, isopropylsilyl group, butoxysilyl group, sec-butylsilyl group, isobutylsilyl group, tert-butylsilyl group, pentylsilyl group, hexylsilyl group and heptylsilyl group. , octylsilyl, nonylsilyl, and decylsilyl groups.

The acyl group used as a substituent refers to a group represented by the formula: -C(=O)-Ra (wherein Ra is an alkyl group). The alkyl group represented by Ra may be linear or branched. The acyl group preferably has 2 to 20 carbon atoms, more preferably 2 to 13 carbon atoms, and still more preferably 2 to 7 carbon atoms. Examples of the acyl group include acetyl group, propionyl group, butyryl group, isobutyryl group, and pivaloyl group.

The acyloxy group used as a substituent refers to a group represented by the formula: -OC(=O)-Rb (wherein Rb is an alkyl group). The alkyl group represented by Rb may be linear or branched. The acyloxy group preferably has 2 to 20 carbon atoms, more preferably 2 to 13 carbon atoms, and still more preferably 2 to 7 carbon atoms. Examples of the acyloxy group include acetoxy group, propionyloxy group, butyryloxy group, isobutyryloxy group, and pivaloyloxy group.

X, X ₁ and X ₂ are "two or more -(CH ₂ )-", and further a cycloalkylene group, a cycloalkenylene group, a cycloalkynylene group, an alkapolyenylene group, an alkadiinylene group and an alkathriynylene group. It may contain a non-aromatic divalent group other than a methylene group, such as a methylene group.

X, X ₁ and X ₂ are, for example, an alkylene group having 2 to 20 carbon atoms which may or may not have a substituent, or A good alkyleneoxy group having 2 to 20 carbon atoms is preferred. In addition, here, when a substituent is included, the number of carbon atoms is the number excluding the number of carbon atoms of the substituent.

Alkyleneoxy groups may have, for example, one or more of the structures shown in the formulas below.
(b1) —O—CH(—CH ₃ )—(O—(CH ₂ ) _p ) _q —O—CH(—CH ₃ )—,
(b2)—(O—(CH ₂ ) _r ) _s —,
(b3) —(O—CH ₂ —CH(—CH ₃ )) _t —,
(b4) —O—CH ₂ —CH(—OH)—CH ₂ —(O—(CH ₂ ) _u ) _v —O—CH ₂ —CH(—OH)—CH ₂ —,
(b5) —(O—(CH ₂ ) _w ) _y —O—CH ₂ —CH(—OH)—, and (b6) —(O—CH ₂ —CH(—CH ₃ )) _z —O—CH ₂ -CH(-OH)-
Here, p, r, u and w are integers of 1 to 20, preferably 1 to 10, more preferably 1 to 6, and more preferably 1 to 3. Here, q, s, t, v, y and z are integers of 1 to 20, more preferably 1 to 10, more preferably 1 to 6, and more preferably 1 to 3.

( _b ) Ar, Ar1 _and Ar2
Next, Ar, Ar ₁ and Ar ₂ in formulas (1) and (2) will be described in detail. As described above, Ar, Ar ₁ and Ar ₂ are "a divalent aromatic-containing hydrocarbon group containing a divalent aromatic group in its main skeleton". In formulas (1) and (2), Ar, Ar ₁ and Ar ₂ may be the same or different, and may or may not have a substituent.

In the "divalent aromatic-containing hydrocarbon group containing a divalent aromatic group in the main skeleton", the aromatic group may be, for example, a phenylene group, a naphthalene group, an anthracene group, or a biphenyl group. Phenylene groups can be ortho, meta, or para phenylene groups. Two or more of the aromatic groups may be contained in the divalent aromatic-containing hydrocarbon group. When two or more aromatic groups are included, the aromatic groups may be directly bonded, or may be bonded via an alkylene group, an ether bond, an ester bond, an amide bond, two carbons bonded by a double bond, or a triple bond. may be bonded via two carbons or the like.

を挙げることができる。 Particularly preferred divalent aromatic-containing hydrocarbon groups include

can be mentioned.

式（２）’中のＸ₃乃至Ｘ₆及びＡｒ₃乃至Ａｒ₄の定義は、上述したＸやＡｒの定義と同様である。式（２）’中のＸ₃、Ｘ₄、ｍ’個のＸ₅、ｍ’個のＸ₆は、互いに同一であっても異なっていてもよい。Ｘ及びＸ₃乃至Ｘ₆は、上述の（ｂ１）～（ｂ６）から選択される基であり得る。ｍ’は１～２０、好ましくは、１～１０の整数である。 The epoxy resin of formula (2) may have a structure represented by formula (2)' below.

The definitions of X ₃ to X ₆ and Ar ₃ to Ar ₄ in formula (2)' are the same as the definitions of X and Ar described above. X ₃ , X ₄ , m′ X ₅ , and m′ X ₆ in Formula (2)′ may be the same or different. X and X ₃ to X ₆ can be groups selected from (b1) to (b6) above. m' is an integer of 1-20, preferably 1-10.

Examples of the first epoxy resin include resins having the following structures (k is an integer of 1 to 20, preferably an integer of 1 to 5).

及び

Furthermore, as the first epoxy resin, for example, a resin having the following structure (h is an integer of 0 to 20, preferably an integer of 0 to 5, i and j are each an integer of 1 to 20, preferably 1 to is an integer of 5, preferably i+j=an integer of 2 to 10).

as well as

Furthermore, as the first epoxy resin, for example, EPICLON EXA-4850-150 (corresponding to formula (1)), DIC EXA-4816 (corresponding to formula (1)), and DIC EXA-4822 (corresponding to formula (1) ); ADEKA's ADEKA RESIN EP-4000S (corresponding to formula (2)), ADEKA resin EP-4000SS (corresponding to formula (2)), ADEKA EP-4003S (corresponding to formula (2)), and EP -4010S (corresponding to formula (2)); Rikaresin BEO-60E and BPO-20E manufactured by Shin Nippon Rika; YL7175-500, YL7175-1000, YL7410, and YX7105 manufactured by Mitsubishi Chemical; Osaka Gas Chemical and Denacol EX-830 manufactured by Nagase ChemteX Co., Ltd., and the like.

[(A2) Second epoxy resin]
The resin composition according to the present embodiment contains a second epoxy resin in addition to the first epoxy resin. The second epoxy resin is not particularly limited as long as the epoxy equivalent is lower than that of the first epoxy resin. The epoxy equivalent of the second epoxy resin is, for example, 80 or more and less than 250, preferably 90 or more and 230 or less, more preferably 95 or more and 200 or less, still more preferably 95 or more and 200 or less, and most preferably 150 or more and 200 or less.

The second epoxy resin preferably has a viscosity of 0.05 Pa·S to 20 Pa·S at 25°C.
The second epoxy resin preferably has a molecular weight of 100-600.

As the second epoxy resin, for example, polyhydric phenols such as bisphenol A, bisphenol F, bisphenol AD, bisphenol E, catechol and resorcinol, and polyhydric alcohols such as glycerin and polyethylene glycol are reacted with epichlorohydrin. polyglycidyl ethers obtained by reacting hydroxy acids such as p-hydroxybenzoic acid and β-hydroxynaphthoic acid with epichlorohydrin; polycarboxylic acids such as phthalic acid and terephthalic acid; polyglycidyl esters obtained by reacting with epichlorohydrin; epoxidized phenol novolac resins, epoxidized cresol novolak resins, epoxidized polyolefins, cycloaliphatic epoxy resins, other urethane-modified epoxy resins; However, it is not limited to these.

As the second epoxy resin, from the viewpoint of maintaining high heat resistance and low moisture permeability, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolak type epoxy resin, biphenylaralkyl type epoxy resin, phenol aralkyl type epoxy resin. , aromatic glycidylamine type epoxy resins, and epoxy resins having a dicyclopentadiene structure are preferred, bisphenol A type epoxy resins and bisphenol F type epoxy resins are more preferred, and bisphenol A type epoxy resins are more preferred.

The second epoxy resin may be liquid or solid. A mixture of liquid resin and solid resin may also be used. Here, "liquid" and "solid" refer to the state of the epoxy resin at room temperature (25°C). From the viewpoints of coatability, workability, and adhesiveness, it is preferable that at least 10% by mass or more of the entire epoxy resin used is a liquid epoxy resin.

Specific examples of the second epoxy resin include bisphenol A type (hereinafter sometimes abbreviated as BPA type) epoxy resin ("jER828EL" and "jER827" manufactured by Mitsubishi Chemical Corporation); bisphenol F type epoxy resin (manufactured by Mitsubishi Chemical Corporation "jER807 "; liquid bisphenol AF type epoxy resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. "ZX1059"), hydrogenated epoxy resin (manufactured by Mitsubishi Chemical Corporation "jERYX8000"); epoxy resin having a butadiene structure (manufactured by Daicel Chemical Industries, Ltd. "PB-3600"), an epoxy resin having a biphenyl structure (manufactured by Mitsubishi Chemical Corporation "YX4000"); a phenol novolac type epoxy resin (manufactured by Mitsubishi Chemical Corporation "jER152"; jER630", and ADEKA's ADEKA RESIN "EP3980S"), etc. Among them, it is preferable to use a BPA-type epoxy resin having high heat resistance and low viscosity, and Mitsubishi Chemical Corporation's "jER828EL", "jER827", and "jER807" are preferred, and "jER828EL" is more preferred.

The mass ratio of the first epoxy resin to the second epoxy resin (first epoxy resin:second epoxy resin) is, for example, 10:1 to 1:10, preferably 10:1 to 1:5, more preferably 9. :1 to 1:2, more preferably 8:1 to 1:1, most preferably 3:7 to 7:3.

The composition may contain an epoxy resin other than the first epoxy resin and the second epoxy resin. However, the total content of the first epoxy resin and the second epoxy resin with respect to the total epoxy resin is preferably 60% by mass or more, more preferably 70% by mass or more, and 80% by mass or more. is more preferable, and 90% by mass or more is most preferable.
Further, the content of the total epoxy resin in the resin composition is, for example, 5 to 60% by mass, preferably 10 to 50% by mass, more preferably 15% by mass, when the non-volatile component of the resin composition is 100% by mass. to 45% by mass, more preferably 20 to 40% by mass.

[(B) thiol compound]
A thiol compound is a compound that functions as a curing agent for epoxy resins. The thiol compound is not particularly limited as long as it is a compound having two or more thiol groups in the molecule.

As the thiol compound, an ester structure-containing thiol containing an ester structure or an ester-free thiol containing no ester structure can be used. Preferably, the thiol compound comprises an ester-free thiol. Ester-free thiol is preferable from the viewpoint of stability because it does not contain an ester group that is hydrolyzed even in a high-temperature and high-humidity environment.
As used herein, the term "ester structure" refers to a structure represented by "--C(=O)O--".

For example, thiol compounds include tris(3-mercaptopropyl) isocyanurate, trimethylolpropane tris(3-mercaptopropionate) (TMTP), trimethylolpropane tris(thioglycolate), pentaerythritol tetrakis(thioglycolate). ), ethylene glycol dithioglycolate, pentaerythritol tetrakis (β-thiopropionate), and dipentaerythritol poly (β-thiopropionate) thiol compounds obtained by the esterification reaction of polyols and mercapto organic acids can be used.

Alternatively, as the thiol compound, at least one compound represented by any one of the following formulas (3) to (5) is also preferably included.

In the above formulas (3) to (5), R ₁ to R ₁₁ each independently represent a linear or branched divalent hydrocarbon group having 1 to 6 carbon atoms,
The hydrocarbon groups represented by R ₁ to R ₁₁ may further contain one or more divalent groups shown in (6) to (8) below.

Preferably, the thiol compound is an ester-free thiol represented by formula (3) or (4) above.

On the other hand, as already mentioned, thiol compounds containing ester structures can also be used. Examples of the thiol compound containing an ester structure include secondary thiols such as Showa Denko Karenz MT PE1, Karenz TPMB, and Karenz NR1.

The thiol equivalent of the thiol compound is, for example, 50-500, preferably 70-300, more preferably 90-200. Incidentally, the thiol equivalent refers to the mass of the thiol compound per thiol group.

The thiol compound is preferably a compound having 2 to 6 thiol groups in one molecule, more preferably a compound having 2 to 4 thiol groups in one molecule, and 2 in one molecule. Compounds having 1 to 3 thiol groups are most preferred.

The content of the thiol compound in the resin composition is such that the ratio of the number of epoxy groups to the number of thiol groups in the resin composition (the number of epoxy groups/the number of thiol groups; that is, the molar ratio) is 0.50 to 10. It is preferably contained in an amount such that 0.0. More preferably, the ratio (epoxy group/thiol group) is between 0.75 and 5.00, more preferably between 0.80 and 2.0.

[(C) inorganic filler]
The resin composition according to this embodiment contains an inorganic filler as described above. Warping after sealing can be suppressed by using an inorganic filler.

The content of the inorganic filler is, for example, 30 to 95 parts by weight, preferably 35 to 95 parts by weight, and for example 70 to 90 parts by weight, based on 100 parts by weight of the total non-volatile content of the resin composition.

Examples of inorganic fillers include, but are not limited to, silica, alumina, barium sulfate, talc, clay, mica, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, At least one selected from the group consisting of aluminum borate, barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, and calcium zirconate.
The inorganic filler preferably contains at least one selected from the group consisting of silica, calcium carbonate, talc, and mica, and more preferably contains silica. As silica, fused silica is preferable, and spherical silica is preferable. Examples of fused silica include fused silica treated with epoxysilane.
The average particle size of the inorganic filler (according to laser diffraction/scattering method) is, for example, 0.3 to 20 μm, preferably 1.0 to 15.0 μm.
The inorganic filler has a specific surface area of, for example, 0.5 to 8.0 m ² /g, preferably 2.0 to 6.0 m ² /g.

[(D) latent curing accelerator]
Examples of the latent curing accelerator used in the resin composition according to the present embodiment include a solid dispersion type latent curing accelerator. A solid dispersion type latent curing accelerator is a solid that is insoluble in an epoxy resin at room temperature (25°C), becomes soluble by heating, and functions as a curing accelerator for an epoxy resin, and is a tertiary amine compound. , imidazole compounds that are solid at room temperature, and solid-dispersed amine adduct-based latent curing accelerators, but are not limited to these. Specific examples of the tertiary amine compound include dimethyl urea compounds such as U-CAT3512T (manufactured by San-Apro Co., Ltd.) and U-CAT3513N (manufactured by Sun-Apro Co., Ltd.). Examples thereof include reaction products of an amine compound and an epoxy compound (amine-epoxy adduct system), reaction products of an amine compound and an isocyanate compound or a urea compound (urea adduct system), etc. Among these, A solid-dispersed amine adduct latent curing accelerator is preferred.

Examples of the imidazole compound that is solid at room temperature include 2-heptadecylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-undecylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4-benzyl-5-hydroxymethylimidazole, 2,4-diamino-6-(2-methylimidazolyl-(1))-ethyl-S-triazine, 2,4-diamino-6-(2' -methylimidazolyl-(1)′)-ethyl-S-triazine isocyanuric acid adduct, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole-trimellitate, 1-cyanoethyl-2-phenylimidazole-trimellitate, N-(2-methylimidazolyl-1-ethyl)-urea, N,N'-(2-methylimidazolyl-(1 )-ethyl)-aziboyldiamide and the like, but are not limited to these.

Epoxy compounds used as one of raw materials for producing the solid-dispersed amine adduct-based latent curing accelerator (amine-epoxy adduct-based) include, for example, bisphenol A, bisphenol F, catechol, polyhydric phenols such as resorcinol, or Polyglycidyl ethers obtained by reacting polyhydric alcohols such as glycerin and polyethylene glycol with epichlorohydrin; reaction of hydroxy acids such as p-hydroxybenzoic acid and β-hydroxynaphthoic acid with epichlorohydrin polyglycidyl esters obtained by reacting polycarboxylic acids such as phthalic acid and terephthalic acid with epichlorohydrin; 4,4'-diaminodiphenylmethane, m-aminophenol, etc. and epi Glycidylamine compounds obtained by reacting with chlorohydrin; polyfunctional epoxy compounds such as epoxidized phenol novolac resin, epoxidized cresol novolak resin, epoxidized polyolefin, butyl glycidyl ether, phenyl glycidyl ether, glycidyl methacrylate, etc. and the like, but are not limited to these.

The amine compound used as a raw material for producing the solid-dispersed amine adduct latent curing accelerator has in its molecule one or more active hydrogens capable of undergoing an addition reaction with an epoxy group, and has a primary amino group and a secondary amino group. and tertiary amino groups as long as they have at least one functional group in the molecule. Examples of such amine compounds include aliphatic amines such as diethylenetriamine, triethylenetetramine, n-propylamine, 2-hydroxyethylaminopropylamine, cyclohexylamine, 4,4'-diamino-dicyclohexylmethane; Aromatic amine compounds such as 4,4′-diaminodiphenylmethane and 2-methylaniline; Nitrogen compounds such as 2-ethyl-4-methylimidazole, 2-ethyl-4-methylimidazoline, 2,4-dimethylimidazoline, piperidine and piperazine Heterocyclic compounds containing atoms; and the like, but are not limited to these.

Among these, compounds having a tertiary amino group in the molecule in particular are raw materials that provide latent curing accelerators having excellent curing accelerating ability. Examples of such compounds include, for example, dimethylaminopropyl Amines, diethylaminopropylamine, di-n-propylaminopropylamine, dibutylaminopropylamine, dimethylaminoethylamine, diethylaminoethylamine, N-methylpiperazine and other amine compounds, 2-methylimidazole, 2-ethylimidal, 2- Primary or secondary amines having a tertiary amino group in the molecule, such as imidazole compounds such as ethyl-4-methylimidazole and 2-phenylimidazole; 2-dimethylaminoethanol, 1-methyl-2-dimethylamino ethanol, 1-phenoxymethyl-2-dimethylaminoethanol, 2-diethylaminoethanol, 1-butoxymethyl-2-dimethylaminoethanol, 1-(2-hydroxy-3-phenoxypropyl)-2-methylimidazole, 1-( 2-hydroxy-3-phenoxypropyl)-2-ethyl-4-methylimidazole, 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazole, 1-(2-hydroxy-3-butoxypropyl)- 2-ethyl-4-methylimidazole, 1-(2-hydroxy-3-phenoxypropyl)-2-phenylimidazoline, 1-(2-hydroxy-3-butoxypropyl)-2-methylimidazoline, 2-(dimethylamino methyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol, N-β-hydroxyethylmorpholine, 2-dimethylaminoethanethiol, 2-mercaptopyridine, 2-benzimidazole, 2-mercaptobenzimidazole, 2 -mercaptobenzothiazole, 4-mercaptopyridine, N,N-dimethylaminobenzoic acid, N,N-dimethylglycine, nicotinic acid, isonicotinic acid, picolinic acid, N,N-dimethylglycine hydrazide, N,N-dimethylpropion alcohols, phenols, thiols, carboxylic acids and hydrazides having a tertiary amino group in the molecule, such as acid hydrazides, nicotinic hydrazides, and isonicotinic hydrazides;

An active hydrogen compound having two or more active hydrogens in the molecule may be added when the epoxy compound and the amine compound are subjected to the addition reaction to produce the latent curing accelerator. Examples of such active hydrogen compounds include polyhydric phenols such as bisphenol A, bisphenol F, bisphenol S, hydroquinone, catechol, resorcinol, pyrogallol, and phenol novolak resins, polyhydric alcohols such as trimethylolpropane, and adipic acid. , polyvalent carboxylic acids such as phthalic acid, 1,2-dimercaptoethane, 2-mercaptoethanol, 1-mercapto-3-phenoxy-2-propanol, mercaptoacetic acid, anthranilic acid, lactic acid and the like. It is not limited.

The isocyanate compound used as a raw material for producing the solid-dispersed amine adduct latent curing accelerator includes, for example, n-butyl isocyanate, isopropyl isocyanate, phenyl isocyanate, monofunctional isocyanate compounds such as benzyl isocyanate; hexamethylene diisocyanate, tri diisocyanate (e.g. 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate), 1,5-naphthalene diisocyanate, diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, xylylene diisocyanate, paraphenylene diisocyanate, 1 , 3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate and other polyfunctional isocyanate compounds; furthermore, terminal isocyanate group-containing compounds obtained by reacting these polyfunctional isocyanate compounds with active hydrogen compounds; can be done. Examples of such terminal isocyanate group-containing compounds include an addition compound having a terminal isocyanate group obtained by the reaction of tolylene diisocyanate and trimethylolpropane, and a terminal isocyanate group obtained by the reaction of tolylene diisocyanate and pentaerythritol. but not limited thereto.

Examples of the urea compound used as a raw material for producing the solid-dispersed amine adduct latent curing accelerator include urea and thiourea, but are not limited thereto.

The solid dispersion type latent curing accelerator is, for example, by appropriately mixing the above production raw materials, reacting at a temperature from room temperature to 200 ° C., cooling and solidifying and pulverizing, or methyl ethyl ketone, dioxane, tetrahydrofuran It can be easily obtained by reacting in a solvent such as the above, removing the solvent, and pulverizing the solid content.

Typical examples commercially available as solid dispersion type latent curing accelerators include, for example, amine-epoxy adduct system (amine adduct system), "Amicure PN-23" manufactured by Ajinomoto Fine-Techno Co., Ltd., "Amicure PN-H", manufactured by ACR, "Hardener X-3661S", "Hardener X-3670S", manufactured by Asahi Kasei Corporation "Novacure HX-3742", "Novacure HX-3721", etc., and Urea-type adducts include, but are not limited to, "FXE-1000", "FXR-1030", and "FXR-1081" manufactured by T&K TOKA.

When the total content of the epoxy resin is 100 parts by mass, the content of the curing accelerator is preferably 0.1 to 100 parts by mass, more preferably 1 to 60 parts by mass, and more preferably 5 to 30 parts by mass. Part is more preferred.

[(E) Storage stabilizer]
A storage stability improver is preferably added to the resin composition according to the present embodiment. Examples of storage stability improvers include borate compounds, titanate compounds, aluminate compounds, zirconate compounds, isocyanate compounds, carboxylic acids, acid anhydrides and mercapto organic acids.

Examples of the borate compounds include trimethylborate, triethylborate (TEB), tri-n-propylborate, triisopropylborate, tri-n-butylborate, tripentylborate, triallylborate, trihexylborate, and tricyclohexylborate. , trioctyl borate, trinonyl borate, tridecyl borate, tridodecyl borate, trihexadecyl borate, trioctadecyl borate, tris(2-ethylhexyloxy) borane, bis(1,4,7,10-tetraoxaundecyl ) (1,4,7,10,13-pentaoxatetradecyl)(1,4,7-trioxaundecyl)borane, tribenzylborate, triphenylborate, tri-o-tolylborate, tri-m- tolyl borate, triethanolamine borate and the like.

Examples of the titanate compounds include tetraethyl titanate, tetrapropyl titanate, tetraisopropyl titanate, tetrabutyl titanate, tetraoctyl titanate and the like.

Examples of the aluminate compound include triethylaluminate, tripropylaluminate, triisopropylaluminate, tributylaluminate, trioctylaluminate and the like.

Examples of the zirconate compound include tetraethyl zirconate, tetrapropyl zirconate, tetraisopropyl zirconate, tetrabutyl zirconate and the like.

Examples of the isocyanate compound include n-butyl isocyanate, isopropyl isocyanate, 2-chloroethyl isocyanate, phenyl isocyanate, p-chlorophenyl isocyanate, benzyl isocyanate, hexamethylene diisocyanate, 2-ethylphenyl isocyanate, and 2,6-dimethylphenyl isocyanate. , tolylene diisocyanate (e.g. 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate), 1,5-naphthalene diisocyanate, diphenylmethane-4,4′-diisocyanate, tolidine diisocyanate, isophorone diisocyanate, xylylene diisocyanate, paraphenylene diisocyanate, bicycloheptane triisocyanate, and the like.

Examples of the carboxylic acid include saturated aliphatic monobasic acids such as formic acid, acetic acid, propionic acid, butyric acid, caproic acid and caprylic acid; unsaturated aliphatic monobasic acids such as acrylic acid, methacrylic acid and crotonic acid; Halogenated fatty acids such as acetic acid and dichloroacetic acid; monobasic oxyacids such as glycolic acid and lactic acid; Aromatic monobasic acids such as aliphatic polybasic acids, benzoic acid, halogenated benzoic acid, toluic acid, phenylacetic acid, cinnamic acid and mandelic acid, and aromatic polybasic acids such as phthalic acid and trimesic acid. .

Examples of the above acid anhydrides include aliphatic or aliphatic polyphenols such as succinic anhydride, dodecynylsuccinic anhydride, maleic anhydride, adducts of methylcyclopentadiene and maleic anhydride, hexahydrophthalic anhydride, and methyltetrahydrophthalic anhydride. Examples include basic acid anhydrides, aromatic polybasic acid anhydrides such as phthalic anhydride, trimellitic anhydride, and pyrrolimelitic anhydride. Typical examples of commercially available acid anhydrides include HN-2200 (molecular weight = 166) manufactured by Hitachi Chemical Co., Ltd., which is methyltetrahydrophthalic anhydride that can also be used as a curing agent for epoxy resins. but not limited to this.

Examples of the mercapto organic acid include mercaptoaliphatic monocarboxylic acids such as mercaptoacetic acid, mercaptopropionic acid, mercaptobutyric acid, mercaptosuccinic acid, and dimercaptosuccinic acid; and mercapto aromatic monocarboxylic acids such as mercaptoaliphatic monocarboxylic acids and mercaptobenzoic acid.

As the storage stability improver, among these, borate compounds are preferable from the viewpoint of high versatility and safety and improvement of storage stability, such as triethylborate, tri-n-propylborate, triisopropylborate, tri- More preferred is n-butyl borate, and even more preferred is triethyl borate.

The content of the storage stability improver is not particularly limited as long as the storage stability of the epoxy resin is improved. It is preferably 0.001 to 50 parts by mass, more preferably 0.05 to 30 parts by mass, even more preferably 0.1 to 10 parts by mass.

The curable resin composition of the present invention can be produced using the above-described tris(3-mercaptopropyl)isocyanurate, epoxy resin, and various optional additives as raw materials. Preparation of the curable resin composition is not particularly difficult, and can be carried out according to conventionally known methods. For example, the one-component thermosetting epoxy resin composition of the present invention can be prepared by mixing each component with a mixer such as a three-roll mixer or a planetary mixer.

[Other ingredients]
Diluents, solvents, pigments, flexibility-imparting agents, coupling agents, antioxidants, and thixotropy-imparting agents commonly used in the field of the present invention may optionally be added to the resin composition according to the present embodiment. , dispersants, etc. can be added.

[How to use the resin composition]
As described above, the resin composition according to the present embodiment is a resin composition for encapsulating wafer level packages, and is preferably molded by compression molding.
That is, the resin composition according to the present embodiment is supplied onto a wafer (or pseudo-wafer) that is a semiconductor substrate. Then, the supplied resin composition is pressurized by a hot plate or the like, heated as necessary, and compression-molded. After that, the molded resin composition is heated and thermally cured. The thermosetting temperature is, for example, 60 to 150°C, preferably 70 to 130°C, more preferably 80 to 120°C. Further, the heat curing time is, for example, 10 minutes to 60 minutes, preferably 10 minutes to 50 minutes, more preferably 15 minutes to 45 minutes. The substrate is then diced to obtain wafer level packages.
The resin composition according to the present embodiment contains a thiol compound with excellent low-temperature curability. Therefore, it is possible to simultaneously perform molding and heat curing of the resin composition during compression molding.

[Characteristics of resin composition]
The viscosity of the resin composition according to the present embodiment is preferably 300 Pa·S or less, more preferably 250 or less, and even more preferably 200 or less. With such a viscosity, suitable fluidity can be obtained in compression molding.

In the resin composition according to the present embodiment, the glass transition temperature of the cured product obtained by heating at 80° C. for 30 minutes is preferably 100° C. or lower, more preferably 80° C. or lower, and 0 It is more preferably ~60°C, for example 5-60°C.

In the resin composition according to the present embodiment, the tensile modulus at 25° C. of the cured product obtained by heating at 80° C. for 30 minutes is preferably 10000 MPa or less, more preferably 5000 MPa or less. More preferably 10 to 4000 MPa.

EXAMPLES The present invention will be described in more detail based on examples below, but the present invention is not limited to the following examples.

Resin compositions according to Examples 1 to 10 and Comparative Example 1 were prepared by mixing each component according to the formulation shown in Table 1. Specifically, the amount of each component shown in Table 1 was weighed into a dedicated plastic container. After that, using a rotation/revolution vacuum mixer Awatori Rentaro (manufactured by Thinky; ARE-250), the mixture is thoroughly mixed at 2000 rpm at room temperature (25 ° C.) and defoamed for 1 minute to obtain the desired resin composition. got
In addition, in Table 1, the compounding quantity of each component means a mass part. In each of the examples and comparative examples, the ratio of the number of epoxy groups to the number of thiol groups in the resin composition was approximately 1:1. Details of the materials used are as follows.

[Epoxy resin]
EXA4850-150: manufactured by DIC, vinyl ether-modified bisphenol A type epoxy resin, epoxy equivalent 450 g / eq, viscosity 15 Pa S (25 ° C.), molecular weight 900, corresponding to formula (1) YX7105: manufactured by Mitsubishi Chemical Corporation, polyalkylene type Epoxy resin, epoxy equivalent weight 485 g/eq, molecular weight 970, viscosity 12 Pa S (25°C)
YL7410: Mitsubishi Chemical Corporation, vinyl ether-modified bisphenol A type epoxy resin, epoxy equivalent 420 g/eq, molecular weight 840, viscosity 0.17 Pa S (25 ° C.)
EG-280: Osaka Gas Chemical Co., Ltd., fluorene type epoxy resin, epoxy equivalent 460 g / eq, molecular weight 520, viscosity 7.4 Pa S (25 ° C.)
jER828EL: manufactured by Mitsubishi Chemical Corporation, viscosity 13 Pa·S, molecular weight 380, bisphenol A type (BPA type) epoxy resin, epoxy equivalent 190 g/eq, neither formula (1) nor formula (2) applies.

[thiol compound]
TMTP: manufactured by Yodo Chemical Co., Ltd., trimethylol-type thiol compound, thiol equivalent 140 g/eq, ester structure-containing thiol compound (following formula)

BPADT: manufactured by Ajinomoto Fine-Techno Co., Ltd., thiol equivalent 188 g/eq, ester-free thiol (following formula)

TMPIC: manufactured by Ajinomoto Fine-Techno Co., Ltd., thiol equivalent 117 g/eq, ester-free thiol (following formula)

[Latent curing accelerator]
PN-23: amine adduct type curing agent manufactured by Ajinomoto Fine Techno Co., Ltd.

[Inorganic filler]
Silica A: spherical silica treated with KBM-403 (3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) with an average particle diameter of 1.0 μm, a maximum cut diameter of 5 μm, a specific surface area of 4.0 m ² /g .
Silica B: spherical silica treated with KBM-403 (3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) with an average particle diameter of 9.0 μm, a maximum cut diameter of 25 μm, a specific surface area of 4.0 m ² /g. .

[others]
TEB: Triethylborate manufactured by Tokyo Kasei Co., Ltd.

[Measuring method]
For the obtained resin compositions according to Examples 1 to 10 and Comparative Example 1, the viscosity, mechanical strength, and glass transition temperature of the cured product were measured by the following procedure. In addition, compression molding was performed using the following procedure, and warpage was measured.

[Viscosity measurement]
Using RE-80U (manufactured by Toki Sangyo Co., Ltd., E-type viscometer, rotor R9.7×3°), the viscosity of each resin composition was measured at 25° C. and 5 rpm.

[Mechanical strength]
Each resin composition was applied onto a release PTFE film (AFLEX 50N: manufactured by Asahi Glass Co., Ltd.) using a bar coater, and cured by heating at 80° C. for 30 minutes. The thickness of the cured product was 50 μm. After that, the PTFE film was released. According to JIS-K-7161, a tensile test was performed using a Tensilon universal testing machine at 25° C., 40% RH, and a tensile speed of 50 mm/min to determine the tensile modulus.

[Glass-transition temperature]
A resin composition was poured into a mold with a thickness of 1 mm and a diameter of 10 mm, heated at 80° C. for 30 minutes to cure, and a test piece was prepared. The coefficient of thermal expansion was measured under the conditions of a compression method, a load of 10 g, a temperature increase rate of 5° C./min, and a measurement temperature range of 0° C. to 200° C., and the change point of the coefficient of thermal expansion was determined as the glass transition temperature.

[Compression mold]
A resin composition was placed on one side of a 12-inch, 0.8 mm-thick silicon wafer so as to have a thickness of 0.4 mm, and molded at 60° C. for 15 minutes with a compression molding machine (manufactured by TOWA, CPM1081M). . After that, it was post-cured at 80° C. for 30 minutes.
[Warpage measurement]
A molded silicon wafer obtained by a "compression mold" was heated and cooled at 35°C, 260°C, and 35°C in order using a shadow moire (manufactured by Akrometrix), and the warp height before and after heating was measured. Regarding the warp height, the silicon wafer was placed on a horizontal surface, the height of the upper surface was measured, and the difference between the height of the highest portion and the height of the lowest portion of the upper surface was obtained as the "height of warp."

Table 1 shows the measurement results obtained.
The resin composition according to Comparative Example 1 does not contain the first epoxy resin. In the resin composition according to Comparative Example 1, the warp height exceeded 1300 μm before heating and exceeded 6000 μm after heating. On the other hand, in Examples 1 to 8, the warp height was 1000 μm or less, and compared with Comparative Example 1, the warp height was significantly reduced both before and after heating.

Claims (20)

(A1) a first epoxy resin that is liquid at 25° C. and has an epoxy equivalent of 250 to 1000;
(A2) a second epoxy resin having a lower epoxy equivalent than the first epoxy resin;
(B) a thiol compound having two or more thiol groups in the molecule, and
(C) including an inorganic filler,
Liquid resin composition for wafer level package sealing by compression molding . The resin composition according to claim 1, wherein the (A1) first epoxy resin has a viscosity of 20 Pa·S or less at 25°C. 3. The resin composition according to claim 1, wherein the (A2) second epoxy resin has an epoxy equivalent of 80 or more and less than 250. 4. The mass ratio (A1:A2) between the (A1) first epoxy resin and the (A2) second epoxy resin is 10:1 to 1:10, according to any one of claims 1 to 3. of the resin composition. 5. The resin composition according to any one of claims 1 to 4, wherein the thiol compound comprises an ester-free thiol. The thiol compound contains at least one compound represented by any one of the following formulas (3) to (5),

In formulas (3) to (5), R ₁ to R ₁₁ each independently represent a linear or branched divalent hydrocarbon group having 1 to 6 carbon atoms,
The hydrocarbon groups represented by R ₁ to R ₁₁ may further contain one or more divalent groups represented by any of the following formulas (6) to (8).

The resin composition according to any one of claims 1 to 4. The thiol compound is tris(3-mercaptopropyl) isocyanurate, trimethylolpropane tris(3-mercaptopropionate) (TMTP), trimethylolpropane tris(thioglycolate), pentaerythritol tetrakis(thioglycolate), 5. The method of claims 1 to 4, comprising at least one compound selected from the group consisting of ethylene glycol dithioglycolate, pentaerythritol tetrakis(β-thiopropionate), and dipentaerythritol poly(β-thiopropionate). The resin composition according to any one of items 1 and 2. The resin composition according to any one of claims 1 to 7, wherein the inorganic filler contains silica. 9. The resin composition according to claim 8, wherein said silica is fused silica. The resin composition according to claim 8 or 9, wherein the silica is spherical. The resin composition according to any one of claims 1 to 10, wherein the content of the inorganic filler is 30 to 95 parts by mass with respect to 100 parts by mass of the total non-volatile content of the resin composition. 12. The resin composition according to any one of claims 1 to 11, further comprising (D) a latent curing accelerator. 13. The resin composition according to claim 12, wherein the latent curing accelerator comprises a solid dispersed latent curing accelerator. 14. The resin composition according to any one of claims 1 to 13, further comprising (E) a storage stabilizer. 15. The resin composition according to claim 14, wherein the storage stabilizer contains one or more selected from borate compounds, titanate compounds, aluminate compounds, zirconate compounds, isocyanate compounds, carboxylic acids, acid anhydrides and mercapto organic acids. . The resin composition according to any one of claims 1 to 15, having a viscosity of 300 Pa·S or less. The resin composition according to any one of claims 1 to 16, wherein a cured product obtained by heating at 80°C for 30 minutes has a glass transition temperature of 100°C or lower. The resin composition according to any one of claims 1 to 17, wherein a cured product obtained by heating at 80°C for 30 minutes has a tensile modulus at 25°C of 10000 MPa or less. a semiconductor substrate;
a sealing layer that seals the semiconductor substrate;
with
The sealing layer is formed of a cured product of the resin composition according to any one of claims 1 to 18,
Wafer level package. A step of supplying the resin composition according to any one of claims 1 to 18 onto a substrate;
a step of molding the supplied resin composition by compression molding;
comprising
A method for manufacturing a wafer level package.