JP7772029B2 - resin composition - Google Patents

Description

The present invention relates to a resin composition. It also relates to a cured product, a semiconductor package, and a semiconductor device.

As a semiconductor package manufacturing method, the mold underfill (MUF) method is expected to contribute to miniaturization and cost reduction, as it uses an encapsulating resin material to fill the narrow gap between the semiconductor chip and the semiconductor package substrate (circuit board) and completely encapsulate the semiconductor chip in one step.

On the other hand, demands for higher integration and multi-functionality in electronic devices are only increasing, and in semiconductor packages, bumps are becoming smaller in diameter, with narrower pitches and gaps due to increased pin counts, while chips are becoming larger due to the trend toward multi-die semiconductors. Furthermore, there is also a demand for large-area packaging, such as in wafer-level packaging (WLP) and panel-level packaging (PLP), and as the flow paths of resin materials during filling and sealing are becoming more complex, there is a demand for even better fluidity in the sealing resin materials used in the MUF method (hereinafter also referred to as "mold underfill materials").

As an example of a resin composition with excellent fluidity, Patent Document 1 discloses a resin composition containing a liquid epoxy resin and a specific radically polymerizable monomer.

JP 2010-24316 A

Semiconductor package encapsulation resin materials are required to have a variety of properties, such as excellent dielectric properties to reduce transmission loss when operating in high-frequency environments, and the ability to suppress warping when forming large-area encapsulation layers in the manufacture of WLP and PLP. These requirements are likely to become increasingly stringent in the future.

To meet these demands and achieve good filling of narrow gaps as mentioned above, it is also desirable to reduce the diameter of the inorganic filler contained in the sealing resin material. However, the inventors have discovered that sealing resin materials that satisfy these required characteristics tend to have poor fluidity during filling and sealing, resulting in the formation of flow marks and unfilled areas (voids), and are also prone to cracking due to temperature cycles during device operation.

The objective of the present invention is to provide a novel resin composition that suppresses the occurrence of voids during encapsulation and also suppresses the occurrence of cracks after curing.

After extensive research, the inventors discovered that the above problems could be solved by using a resin composition having the following composition, leading to the completion of the present invention.

That is, the present invention includes the following.
<1>
A resin composition that satisfies the following melt viscosity and storage modulus conditions.
<Melt viscosity conditions>
When the melt viscosity is measured at 120°C, the initial melt viscosity is MV1 (Pa s), and the melt viscosity after 2 minutes is MV2 (Pa s).
MV2/MV1≦10 and MV2≦3000
is.
<Storage modulus conditions>
When the storage modulus of the cured product obtained by heating the resin composition at 150°C for 60 minutes is SM1 (GPa) at 23°C and the storage modulus of the cured product at temperature T is SM2 (GPa),
0.4<SM2/SM1
Here, the temperature T is Tg-30 (°C), where Tg (°C) is the glass transition temperature of the cured product.
<2>
The resin composition according to <1>, comprising a silane compound (a1) represented by the following formula (A-1):
(RO) _n SiAr _4-n (A-1)
(In the formula, R represents an alkyl group, Ar represents an aryl group which may have a substituent, and n represents 1 or 2.)
<3>
one or more curing agents (b1) selected from acid anhydride curing agents and amine curing agents, and one or more curing accelerators (c1) selected from imidazole curing accelerators.
The resin composition according to <1>, comprising at least one of the following:
＜4＞
one or more curing agents (b1) selected from acid anhydride curing agents and amine curing agents, and one or more curing accelerators (c1) selected from imidazole curing accelerators.
The resin composition according to <2>, comprising at least one of the following:
<5>
<4> The resin composition according to any one of <2> to <4>, further comprising another silane compound (a2).
<6>
<5> The resin composition according to any one of <3> to <5>, wherein the mass ratio of the total of the curing agent (b1) and the curing accelerator (c1) to the silane compound (a1) [(curing agent (b1) + curing accelerator (c1)) / silane compound (a1)] is 1 or more.
＜７＞
<5> or <6>, wherein the mass ratio of the silane compound (a2) to the silane compound (a1) (silane compound (a2)/silane compound (a1)) is 0.1 or more.
＜8＞
<7> The resin composition according to any one of <1> to <7>, comprising an inorganic filler having an average particle size of 3 μm or less.
＜９＞
<9> The resin composition according to any one of <1> to <8>, further comprising a stress relaxation agent.
<10>
The resin composition according to any one of <1> to <9>, which is for use in a mold underfill.
<11>
<10> A cured product of the resin composition according to any one of <1> to <10>.
<12>
<10> A semiconductor package comprising a cured product of the resin composition according to any one of <1> to <10>.
<13>
The semiconductor package according to <12>, which is a fan-out type package.
<14>
<10> A semiconductor device comprising a cured product of the resin composition according to any one of <1> to <10>.

The present invention provides a novel resin composition that suppresses the generation of voids during encapsulation and also suppresses the generation of cracks after curing.

<Terminology>
As used herein, the term "optionally substituted" in reference to a compound or group means both a case where the hydrogen atoms of the compound or group are not substituted with substituents, and a case where some or all of the hydrogen atoms of the compound or group are substituted with substituents.

The present invention will be described in detail below, showing embodiments and examples. However, the present invention is not limited to the following embodiments and examples, and can be modified and implemented as desired within the scope of the claims of the present invention and their equivalents.

[Resin composition]
The resin composition of the present invention is characterized by satisfying the following melt viscosity conditions and storage modulus conditions.
<Melt viscosity conditions>
When the melt viscosity is measured at 120°C, the initial melt viscosity is MV1 (Pa s), and the melt viscosity after 2 minutes is MV2 (Pa s).
MV2/MV1≦10 and MV2≦3000
is.
<Storage modulus conditions>
When the storage modulus of the cured product obtained by heating the resin composition at 150°C for 60 minutes is SM1 (GPa) at 23°C and the storage modulus of the cured product at temperature T is SM2 (GPa),
0.4<SM2/SM1
Here, the temperature T is Tg-30 (°C), where Tg (°C) is the glass transition temperature of the cured product.

As mentioned above, encapsulating resin materials for semiconductor packages are required to have various properties, such as excellent dielectric properties to reduce transmission loss when operating in high-frequency environments, and the ability to suppress warping when forming large-area encapsulating layers in the manufacture of WLP and PLP. Furthermore, these requirements are expected to become increasingly stringent in the future. While meeting these requirements, reducing the diameter of the inorganic filler contained in the encapsulating resin material is also desirable to achieve good filling of narrow gaps in the MUF method. However, the inventors have discovered that encapsulating resin materials that satisfy these required properties tend to develop flow marks and unfilled areas (voids) due to poor fluidity during filling and sealing, and are also prone to cracking due to temperature cycles during device operation.

In contrast, the resin composition of the present invention, which satisfies the above melt viscosity and storage modulus conditions, can suppress the occurrence of voids during encapsulation and also suppress the occurrence of cracks after curing.

- Melt viscosity conditions -
When the melt viscosity of the resin composition of the present invention is measured at 120°C, the melt viscosity exhibits a specific time dependency.

Specifically, when the initial melt viscosity measured at 120°C is MV1 (Pa s), and the melt viscosity after 2 minutes is MV2 (Pa s), MV1 and MV2 are
MV2/MV1≦10 and MV2≦3000
Satisfy the relationship.

Methods for measuring and evaluating the melt viscosity of a resin composition include temperature dependency measurement (temperature dependency mode), time dependency measurement (time dependency mode), and strain/frequency dependency measurement (strain dependency mode or frequency dependency mode). In the present invention, we have discovered that in order to achieve a resin composition that suppresses the generation of voids during encapsulation and also suppresses the generation of cracks after curing, it is important that the melt viscosity measured in the time dependency mode at a constant temperature of 120°C satisfy a specific time dependency.

In the present invention, the time dependence of the melt viscosity of a resin composition is identified and evaluated based on the initial melt viscosity (MV1) (at measurement start time t) and the melt viscosity MV2 two minutes after measurement start time t. The conditions that MV1 and MV2 must satisfy are described below. MV1 and MV2 are based on the initial melt viscosity (at measurement start time t) and the melt viscosity two minutes after measurement start time t, as described in <Melt Viscosity Measurement> below, measured in time-dependent mode using a dynamic viscoelasticity measuring device under conditions of a constant temperature of 120°C, a strain of 1 degC, and a frequency of 1 Hz.

--MV2/MV1 ratio--
From the viewpoint of achieving a resin composition that can suppress the generation of voids during sealing and also suppress the generation of cracks after curing, the resin composition has an initial melt viscosity MV1 (Pa s) when the melt viscosity is measured at 120°C and a melt viscosity MV2 (Pa s) after 2 minutes have elapsed, which satisfies the relationship MV2/MV1≦10.

From the viewpoint of further enjoying the effects of the present invention, and particularly from the viewpoint of further suppressing the occurrence of voids during encapsulation, the MV2/MV1 ratio is preferably 9.5 or less, 9 or less, or 8.5 or less, more preferably 8 or less, 7 or less, or 6 or less, and even more preferably 5 or less, 4 or less, 3 or less, 2.5 or less, or 2 or less. The lower limit of the MV2/MV1 ratio is not particularly limited and may be, for example, 0.8 or more, 0.9 or more, 0.95 or more, or 1 or more. In addition to satisfying the storage modulus condition described below, an MV2/MV1 ratio of 5 or less is particularly preferred because it makes it easier to achieve a resin composition that suppresses the occurrence of voids during encapsulation and also suppresses the occurrence of cracks after curing, even when a high amount of inorganic filler with a small diameter (e.g., average particle size 3 μm or less, 2.5 μm or less, 2 μm or less, or 1.5 μm or less) is incorporated.

--MV2 value--
From the viewpoint of achieving a resin composition that can suppress the generation of voids during sealing and also suppress the generation of cracks after curing, the resin composition has a melt viscosity MV2 (Pa s) after 2 minutes has elapsed when the melt viscosity is measured at 120°C, and satisfies the relationship MV2≦3000.

From the viewpoint of further enjoying the effects of the present invention, particularly from the viewpoint of further suppressing the occurrence of voids during encapsulation and from the viewpoint of further suppressing the occurrence of flow marks, the MV2 value is preferably 2800 or less, 2600 or less, 2400 or less, or 2200 or less, more preferably 2000 or less, 1800 or less, 1600 or less, or 1500 or less, and even more preferably 1400 or less, 1200 or less, 1000 or less, or 800 or less. The lower limit of the MV2 value is not particularly limited and may be, for example, 100 or more, 120 or more, 140 or more, 150 or more, etc. An MV2 value of 1500 or less, in particular, satisfies the storage modulus condition described below, and is preferred because it facilitates the achievement of a resin composition that suppresses the occurrence of voids during encapsulation and cracks after curing, even when a high amount of inorganic filler with a small diameter (e.g., average particle size 3 μm or less, 2.5 μm or less, 2 μm or less, or 1.5 μm or less) is incorporated.

The initial melt viscosity MV1 value when measuring the melt viscosity at 120°C is not particularly limited in relation to the MV2 value, as long as the MV2/MV1 ratio satisfies the above conditions.

-Storage modulus conditions-
The resin composition of the present invention exhibits a specific storage modulus when cured by heating the resin composition at 150° C. for 60 minutes.

Specifically, when the storage modulus of a cured product obtained by heating the resin composition at 150°C for 60 minutes is SM1 (GPa) at 23°C and the storage modulus of a cured product at temperature T is SM2 (GPa), SM1 and SM2 satisfy the following conditions:
0.4<SM2/SM1
Here, the temperature T is Tg-30 (°C), where Tg (°C) is the glass transition temperature of the cured product.

The storage modulus (E') of a cured resin varies significantly depending on whether it is in a glassy or rubbery state; that is, it tends to vary significantly near the glass transition temperature. In this invention, in order to achieve a resin composition that suppresses the generation of voids during encapsulation and also suppresses the generation of cracks after curing, it has been discovered that it is important that the ratio of the storage modulus at 23°C of a cured product obtained by heating at 150°C for 60 minutes to the storage modulus at a temperature T (= Tg - 30) (°C) 30°C lower than the glass transition temperature Tg of the cured product be within a specific range.

In the present invention, the storage modulus of a cured resin composition is evaluated based on SM2/SM1, the ratio of the storage modulus SM1 at 23°C to the storage modulus SM2 at a temperature T (= Tg - 30), which is 30°C lower than the glass transition temperature Tg of the cured resin composition. The conditions that SM1 and SM2 must satisfy are described below. As described in <Measurement of Tg and Storage Modulus> below, SM1 and SM2 are based on the storage modulus values at 23°C and at temperature T (= Tg - 30) (°C) when dynamic mechanical analysis is performed in tension mode using a dynamic mechanical analyzer (dynamic viscoelasticity measuring device) at a frequency of 1 Hz and a heating rate of 5°C/min. Tg is determined as the temperature (°C) showing the maximum peak value of tan δ (= loss modulus E" / storage modulus E') when dynamic mechanical analysis is performed under the same conditions and mode.

--SM2/SM1 ratio--
From the viewpoint of achieving a resin composition that can suppress the generation of voids during encapsulation and also suppress the generation of cracks after curing, the resin composition is such that, when the storage modulus at 23°C of a cured product obtained by heating the resin composition at 150°C for 60 minutes is SM1 (GPa) and the storage modulus at temperature T is SM2 (GPa), SM1 and SM2 satisfy the relationship 0.4<SM2/SM1.

From the viewpoint of further enjoying the effects of the present invention, and particularly from the viewpoint of further suppressing cracking after curing, the SM2/SM1 ratio is preferably 0.42 or greater or 0.44 or greater, more preferably 0.45 or greater, 0.46 or greater, or 0.48 or greater, and even more preferably 0.5 or greater, 0.52 or greater, 0.54 or greater, or 0.55 or greater. The upper limit of the SM2/SM1 ratio is not particularly limited and may be, for example, 1 or less, 0.9 or less, 0.85 or less, or 0.8 or less. In addition to satisfying the melt viscosity condition described above, an SM2/SM1 ratio of 0.5 or greater is particularly preferable because it facilitates the achievement of a resin composition that suppresses void generation during encapsulation and also suppresses cracking after curing, even when a high amount of inorganic filler with a small diameter (e.g., average particle size 3 μm or less, 2.5 μm or less, 2 μm or less, or 1.5 μm or less) is incorporated.

The SM1 value is not particularly limited as long as the above-mentioned SM2/SM1 ratio condition is satisfied in relation to the SM2 value. However, from the viewpoint of better enjoying the effects of the present invention in combination with the melt viscosity conditions described above, the SM1 value is preferably 50 GPa or less, more preferably 45 GPa or less, 40 GPa or less, 35 GPa or less, or 30 GPa or less, and even more preferably 28 GPa or less, 26 GPa or less, or 25 GPa or less. The lower limit of the SM1 value is not particularly limited, and can be, for example, 3 GPa or more, 4 GPa or more, 5 GPa or more, etc.

From the viewpoint of realizing a semiconductor package exhibiting good heat resistance, the glass transition temperature Tg of the cured product obtained by heating the resin composition of the present invention at 150°C for 60 minutes is preferably 140°C or higher, more preferably 150°C or higher, and even more preferably 160°C or higher, 170°C or higher, or 180°C or higher. The upper limit of the glass transition temperature Tg is not particularly limited, and can be, for example, 250°C or lower, 240°C or lower, or 230°C or lower.

The resin composition of the present invention is not particularly limited in its composition, as long as it satisfies the above-mentioned melt viscosity and storage modulus conditions and is applicable to the MUF method in the manufacture of semiconductor packages, i.e., as long as it exhibits fluidity under the conditions of filling and sealing and can form a sealing layer after curing.

Below, we will explain the composition and ingredients that are suitable from the perspective of satisfying the above melt viscosity and storage modulus conditions.

-Epoxy resin-
The resin composition of the present invention preferably contains an epoxy resin, from the viewpoints of providing a cured product exhibiting good dielectric properties and exhibiting good fluidity during filling and sealing.

The type of epoxy resin is not particularly limited, as long as it contains one or more (preferably two or more) epoxy groups per molecule. Examples of epoxy resins include bisphenol-type epoxy resins, dicyclopentadiene-type epoxy resins, trisphenol-type epoxy resins, naphthol novolac-type epoxy resins, phenol novolac-type epoxy resins, tert-butyl-catechol-type epoxy resins, naphthalene-type epoxy resins, naphthol-type epoxy resins, anthracene-type epoxy resins, glycidylamine-type epoxy resins, glycidyl ester-type epoxy resins, cresol novolac-type epoxy resins, biphenyl-type epoxy resins, linear aliphatic epoxy resins, epoxy resins containing a butadiene structure, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring-containing epoxy resins, cyclohexane-type epoxy resins, cyclohexanedimethanol-type epoxy resins, naphthylene ether-type epoxy resins, trimethylol-type epoxy resins, and tetraphenylethane-type epoxy resins. Bisphenol-type epoxy resins refer to epoxy resins having a bisphenol structure, such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, and bisphenol AF-type epoxy resins. Biphenyl-type epoxy resins refer to epoxy resins having a biphenyl structure, where the biphenyl structure may have a substituent such as an alkyl group, an alkoxy group, or an aryl group. Therefore, bixylenol-type epoxy resins and biphenylaralkyl-type epoxy resins are also included in biphenyl-type epoxy resins. Epoxy resins may be used alone or in combination of two or more.

Epoxy resins include those that are liquid at a temperature of 20°C (hereinafter referred to as "liquid epoxy resins") and those that are solid at a temperature of 20°C (hereinafter referred to as "solid epoxy resins"). From the perspective of creating a resin composition that exhibits good fluidity during filling and sealing, it is preferable to include a liquid epoxy resin as the epoxy resin. In one embodiment, when the total amount of epoxy resin (non-volatile components) is taken as 100% by mass, the content of the liquid epoxy resin is preferably 70% by mass or more (preferably 80% by mass or more, 90% by mass or more).

Preferably, the liquid epoxy resin is one having two or more epoxy groups per molecule.

Preferred liquid epoxy resins are bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, glycidyl amine type epoxy resins, phenol novolac type epoxy resins, alicyclic epoxy resins such as alicyclic epoxy resins having an ester skeleton, cyclohexane type epoxy resins, and cyclohexane dimethanol type epoxy resins.

Specific examples of liquid epoxy resins include DIC's "HP4032," "HP4032D," and "HP4032SS" (naphthalene-type epoxy resins); Mitsubishi Chemical's "828US," "828EL," "jER828EL," and "825" (bisphenol A-type epoxy resins); Mitsubishi Chemical's "jER807" and "1750" (bisphenol F-type epoxy resins); Mitsubishi Chemical's "jER152" (phenol novolac-type epoxy resin); Mitsubishi Chemical's "630," "630LSD," and "604" (glycidylamine-type epoxy resins); ADEKA's "ED-523T" (glycilol-type epoxy resin); and ADEKA's "EP-3950L" and "EP -3980S" (glycidylamine type epoxy resin); ADEKA Corporation's "EP-4088S" (dicyclopentadiene type epoxy resin); Nippon Steel Chemical & Material Co., Ltd.'s "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin); Nagase ChemteX Corporation's "EX-721" (glycidyl ester type epoxy resin); Daicel Corporation's "Celloxide 2021P" (alicyclic epoxy resin with an ester skeleton); Nippon Steel Chemical & Material Co., Ltd.'s "ZX1658" and "ZX1658GS" (1,4-glycidylcyclohexane type epoxy resin), and Mitsubishi Chemical Corporation's "YX8000" (hydrogenated bisphenol A type epoxy resin).

The epoxy equivalent of the epoxy resin is preferably in the range of 50 g/eq. to 300 g/eq., with the upper limit being more preferably 250 g/eq. or less, and even more preferably 240 g/eq. or less, 220 g/eq. or less, 200 g/eq. or less, or 180 g/eq. or less. The epoxy group equivalent is the mass of resin per equivalent of epoxy groups. This epoxy equivalent can be measured in accordance with JIS K7236.

From the viewpoint of easily achieving a resin composition that satisfies the above melt viscosity and storage modulus conditions, the content of epoxy resin in the resin composition is preferably 5% by mass or more, more preferably 10% by mass or more, and even more preferably 15% by mass or more, 20% by mass or more, 22% by mass or more, 24% by mass or more, or 25% by mass or more, based on 100% by mass of the resin components in the resin composition. The upper limit of this content is not particularly limited and may be determined depending on the properties required of the resin composition, but may be, for example, 90% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less.

In the present invention, the term "resin component" used in reference to a resin composition refers to the non-volatile components constituting the resin composition, excluding the inorganic filler described below.

-Inorganic filler-
The resin composition of the present invention preferably contains an inorganic filler, which can provide a cured product exhibiting good dielectric properties (low dielectric dissipation factor) and can also suppress warpage when forming a large-area sealing layer in the production of WLP or PLP.

Examples of inorganic filler materials include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum silicate, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium titanate zirconate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly preferred. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. Spherical silica is preferred. These inorganic fillers may be used alone or in combination.

Commercially available inorganic fillers include "SP60-05" and "SP507-05" manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YC100C," "YA050C," "YA050C-MJE," "YA010C," "SC2500SQ," "SO-C4," "SO-C2," and "SO-C1" manufactured by Admatechs Co., Ltd.; "UFP-30," "DAW-03," and "FB-105FD" manufactured by Denka Co., Ltd.; "Silfil NSS-3N," "Silfil NSS-4N," and "Silfil NSS-5N" manufactured by Tokuyama Corporation; "CellSpheres" and "MGH-005" manufactured by Taiheiyo Cement Corporation; and "Sfereek" and "BA-1" manufactured by JGC Catalysts and Chemicals Co., Ltd.

To achieve good filling of narrow gaps, the average particle size of the inorganic filler is preferably 10 μm or less, more preferably 5 μm or less, and even more preferably 3 μm or less. As previously mentioned, the inventors have discovered that encapsulating resin materials containing small-diameter inorganic fillers tend to develop flow marks and unfilled areas (voids) due to poor fluidity during filling and encapsulation, and are prone to cracking due to temperature cycles during device operation. In contrast, the resin composition of the present invention, which satisfies the above-mentioned melt viscosity and storage modulus conditions, suppresses the generation of voids during filling and encapsulation, and after curing, suppresses the generation of cracks, allowing the use of smaller-diameter inorganic fillers. For example, the average particle size of the inorganic filler may be as small as 2.5 μm or less, 2 μm or less, 1.5 μm or less, 1 μm or less, or 0.7 μm or less. There is no particular lower limit to the average particle size, but it is preferably 0.01 μm or more, more preferably 0.05 μm or more, and even more preferably 0.07 μm or more, 0.1 μm or more, or 0.2 μm or more.

The average particle size of an inorganic filler can be measured using a laser diffraction/scattering method based on Mie scattering theory. Specifically, a volumetric particle size distribution of the inorganic filler is created using a laser diffraction/scattering particle size distribution analyzer, and the median diameter is used as the average particle size. A measurement sample can be prepared by weighing 100 mg of inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing the mixture ultrasonically for 10 minutes. The volumetric particle size distribution of the inorganic filler is measured using a laser diffraction particle size distribution analyzer with blue and red light source wavelengths using a flow cell system, and the average particle size is calculated as the median diameter from the particle size distribution obtained. Examples of laser diffraction particle size distribution analyzers include the LA-960 manufactured by Horiba, Ltd.

The specific surface area of the inorganic filler is not particularly limited, but is preferably 0.1 m ² /g or more, more preferably 0.5 m ² /g or more, even more preferably 1 m ² /g or more, 3 m ² /g or more, or 5 m ² /g or more. The upper limit of the specific surface area is not particularly limited, but is preferably 80 m ² /g or less, more preferably 60 m ² /g or less, even more preferably 50 m ² /g or less, or 40 m ² /g or less. The specific surface area of the inorganic filler can be obtained according to the BET method by adsorbing nitrogen gas onto the surface of a sample using a specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) and calculating the specific surface area using the BET multipoint method.

The inorganic filler is preferably surface-treated with an appropriate surface treatment agent. This surface treatment can improve the moisture resistance and dispersibility of the inorganic filler. Various silane compounds may be used as the surface treatment agent, including, for example, vinyl silane coupling agents, epoxy silane coupling agents, styryl silane coupling agents, (meth)acrylic silane coupling agents, amino silane coupling agents, isocyanurate silane coupling agents, ureido silane coupling agents, mercapto silane coupling agents, isocyanate silane coupling agents, and acid anhydride silane coupling agents; alkoxysilane compounds such as methyltrimethoxysilane and phenyltrimethoxysilane; and silazane compounds. One type of surface treatment agent may be used alone, or two or more types may be used in combination.

Commercially available surface treatment agents include, for example, Shin-Etsu Chemical Co., Ltd.'s "KBM403" (3-glycidoxypropyltrimethoxysilane), "KBM803" (3-mercaptopropyltrimethoxysilane), "KBE903" (3-aminopropyltriethoxysilane), "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), and "SZ-31" (hexamethyldisilazane).

The degree of surface treatment with the surface treatment agent preferably falls within a specified range from the perspective of improving the dispersibility of the inorganic filler. Specifically, it is preferable that 100% by mass of the inorganic filler be surface-treated with 0.2 to 5% by mass of the surface treatment agent.

The degree of surface treatment with a surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/ ^m² or more, more preferably 0.1 mg/ ^m² or more, and even more preferably 0.2 mg/ ^m² or more. On the other hand, from the viewpoint of suppressing an increase in the melt viscosity of the resin composition and easily realizing a resin composition that satisfies the above melt viscosity conditions, the amount of carbon per unit surface area of the inorganic filler is preferably 1.0 mg/ ^m² or less, more preferably 0.8 mg/ ^m² or less, and even more preferably 0.5 mg/ ^m² or less. The amount of carbon per unit surface area of the inorganic filler can be measured after the surface-treated inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler surface-treated with the surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer, such as the "EMIA-320V" manufactured by Horiba, Ltd.

To facilitate the realization of a resin composition that provides an even lower dielectric tangent and thermal expansion coefficient, the content of the inorganic filler in the resin composition is, for example, 50% by mass or more, preferably 60% by mass or more, more preferably 65% by mass or more, and even more preferably 70% by mass or more, 75% by mass or more, 76% by mass or more, 78% by mass or more, or 80% by mass or more, based on 100% by mass of the non-volatile components in the resin composition. The upper limit of the inorganic filler content is not particularly limited, but can be, for example, 90% by mass or less, 85% by mass or less, etc.

-Silane compounds-
The resin composition of the present invention preferably contains a silane compound from the viewpoint of achieving good filling properties for narrow gaps.

From the viewpoint of easily realizing a resin composition that satisfies the above melt viscosity and storage modulus conditions, the silane compound is preferably a silane compound (a1) represented by the following formula (A-1).
(RO) _n SiAr _4-n (A-1)
(In the formula, R represents an alkyl group, Ar represents an aryl group which may have a substituent, and n represents 1 or 2.)

The alkyl group represented by R may be either linear or branched. The alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, and even more preferably 1 to 4 carbon atoms. Among these, the alkyl group is preferably one or more selected from the group consisting of methyl, ethyl, propyl, isopropyl, and cyclopropyl.

The aryl group in Ar preferably has 6 to 14 carbon atoms, more preferably 6 to 10. The substituent that the aryl group may have is preferably one or more selected from the group consisting of a halogen atom, an alkyl group, an alkoxy group, and a cycloalkyl group, and more preferably one or more selected from the group consisting of a fluorine atom, an alkyl group having 1 to 10 carbon atoms (preferably 1 to 6, 1 to 4), an alkoxy group having 1 to 10 carbon atoms (preferably 1 to 6, 1 to 4), and a cycloalkyl group having 3 to 10 carbon atoms (preferably 6 to 10).

n is preferably 2.

Examples of the silane compound (a1) include diphenyldialkoxysilanes such as diphenyldimethoxysilane, diphenyldiethoxysilane, diphenyldipropoxysilane, diphenylmethoxyethoxysilane, diphenylmethoxypropoxysilane, and diphenylethoxypropoxysilane; and triphenylalkoxysilanes such as triphenylmethoxysilane, triphenylethoxysilane, and triphenylpropoxysilane. Diphenyldialkoxysilanes are preferred, and diphenyldimethoxysilane is more preferred.

The resin composition of the present invention may contain, as a silane compound, a silane compound (a2) other than the silane compound (a1).

The other silane compound (a2) is not particularly limited and may, for example, be a vinyl silane coupling agent, an epoxy silane coupling agent, a styryl silane coupling agent, a (meth)acrylic silane coupling agent, an amino silane coupling agent, an isocyanurate silane coupling agent, a ureido silane coupling agent, a mercapto silane coupling agent, an isocyanate silane coupling agent, or an acid anhydride silane coupling agent. Therefore, in one embodiment, the resin composition of the present invention includes, as the silane compound (a2), a silane compound containing one or more reactive groups selected from the group consisting of a vinyl group, an epoxy group, a styryl group, a (meth)acrylic group, an amino group, an isocyanurate group, a ureido group, a mercapto group, an isocyanate group, and an acid anhydride group.

Among these, from the viewpoint of easily realizing a resin composition that satisfies the above-mentioned melt viscosity and storage modulus conditions in combination with silane compound (a1), silane compound (a2) is preferably a silane compound containing one or more reactive groups selected from the group consisting of vinyl groups, epoxy groups, styryl groups, (meth)acrylic groups, and amino groups, and more preferably a silane compound containing one or more reactive groups selected from the group consisting of epoxy groups and amino groups.

When the resin composition of the present invention contains a silane compound, the content of the silane compound in the resin composition is preferably 0.5% by mass or more, more preferably 0.6% by mass or more, 0.8% by mass or more, 1% by mass or more, 1.2% by mass or more, 1.4% by mass or more, or 1.5% by mass or more, based on 100% by mass of the resin components in the resin composition, from the viewpoint of easily realizing a resin composition that satisfies the above-mentioned melt viscosity and storage modulus conditions. The upper limit of the content of the silane compound is preferably 5% by mass or less, more preferably 4.5% by mass or less, 4% by mass or less, 3.5% by mass or less, or 3% by mass or less, based on 100% by mass of the resin components in the resin composition, from the viewpoint of easily realizing a resin composition that satisfies the above-mentioned melt viscosity and storage modulus conditions.

As described above, from the viewpoint of easily achieving a resin composition that satisfies the above melt viscosity and storage modulus conditions, the silane compound preferably includes silane compound (a1), and more preferably includes a combination of silane compound (a1) and silane compound (a2). From the viewpoint of easily achieving the above melt viscosity and storage modulus conditions and more easily enjoying the effects of the present invention, the mass ratio of silane compound (a2) to silane compound (a1) (silane compound (a2)/silane compound (a1)) is preferably 0.1 or more, more preferably 0.2 or more, even more preferably 0.3 or more, 0.4 or more, or 0.5 or more, with the upper limit preferably being 2 or less, more preferably 1.8 or less, 1.6 or less, or 1.5 or less.

- Hardener -
The resin composition of the present invention preferably contains a curing agent.

The curing agent is not particularly limited as long as it has the function of curing the epoxy resin, and examples include acid anhydride curing agents, amine curing agents, phenolic curing agents, naphthol curing agents, active ester curing agents, benzoxazine curing agents, cyanate ester curing agents, and carbodiimide curing agents. One type of curing agent may be used alone, or two or more types may be used in combination.

In particular, from the viewpoint of realizing a resin composition that exhibits good fluidity during filling and sealing, and from the viewpoint of easily realizing a resin composition that satisfies the above-mentioned melt viscosity and storage modulus conditions, it is preferable that the curing agent include one or more curing agents (b1) selected from the group consisting of acid anhydride-based curing agents and amine-based curing agents.

Suitable acid anhydride curing agents, which are curing agents (b1), include curing agents having one or more acid anhydride groups in one molecule.

Specific examples of acid anhydride curing agents include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenyl succinic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, and benzophenonetetracarboxylic dianhydride. Examples of acid anhydrides include polymeric acid anhydrides such as styrene-maleic acid resins, which are copolymers of styrene and maleic acid, ethylene glycol bis(anhydrotrimellitate), ethylene glycol bis(anhydrotrimellitate), ethylene glycol bis(anhydrotrimellitate), and ethylene glycol bis(anhydrotrimellitate).

Commercially available acid anhydride curing agents include "HNA-100" and "MH-700" manufactured by New Japan Chemical Co., Ltd.

Amine-based curing agents suitable as curing agent (b1) include curing agents having one or more amino groups in one molecule, such as aliphatic amines, polyether amines, alicyclic amines, and aromatic amines.

Specific examples of amine-based curing agents include 4,4'-methylenebis(2,6-dimethylaniline), diphenyldiaminosulfone, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenyl ether, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, 2,2-bis(3-amino-4-hydroxybenzidine), Bis(4-aminophenyl)propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis(4-(4-aminophenoxy)phenyl)sulfone, bis(4-(3-aminophenoxy)phenyl)sulfone, etc.

Commercially available amine-based curing agents include, for example, "KAYABOND C-200S," "KAYABOND C-100," "KAYAHARD A-A," "KAYAHARD A-B," and "KAYAHARD A-S" manufactured by Nippon Kayaku Co., Ltd., and "Epicure W" manufactured by Mitsubishi Chemical Corporation.

The curing agent may also include one or more curing agents (b2) selected from the group consisting of phenol-based curing agents, naphthol-based curing agents, active ester-based curing agents, benzoxazine-based curing agents, cyanate ester-based curing agents, and carbodiimide-based curing agents.

From the viewpoint of heat resistance and water resistance, phenol-based and naphthol-based curing agents preferably have a novolac structure. Furthermore, from the viewpoint of adhesion to the conductor layer, nitrogen-containing phenol-based and nitrogen-containing naphthol-based curing agents are preferred, with triazine-based phenol-based and triazine-based naphthol-based curing agents being more preferred. Specific examples of phenol-based and naphthol-based curing agents include "MEH-7700," "MEH-7810," "MEH-7851," and "MEH-8000H" manufactured by Meiwa Kasei Co., Ltd.; "NHN," "CBN," and "GPH" manufactured by Nippon Kayaku Co., Ltd.; and "SN-170," "SN-180," "SN-190," "SN-475," "SN-485," "SN-495," "SN-495V," and "SN-37" manufactured by Nippon Steel Chemical & Material Co., Ltd. 5" and "SN-395" manufactured by DIC Corporation; "TD-2090", "TD-2090-60M", "LA-7052", "LA-7054", "LA-1356", "LA-3018", "LA-3018-50P", "EXB-9500", "HPC-9500", "KA-1160", "KA-1163", and "KA-1165" manufactured by Gun-ei Chemical Co., Ltd.; "GDP-6115L", "GDP-6115H", and "ELPC75" manufactured by Gun-ei Chemical Co., Ltd.

As the active ester curing agent, a compound having one or more active ester groups per molecule can be used. Among them, preferred active ester curing agents are compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. The active ester curing agent is preferably one obtained by a condensation reaction between a carboxylic acid compound and/or a thiocarboxylic acid compound and a hydroxy compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, active ester curing agents derived from carboxylic acid compounds are preferred, active ester curing agents obtained from a carboxylic acid compound and a hydroxy compound are more preferred, and active ester curing agents obtained from a carboxylic acid compound and an aromatic hydroxy compound are even more preferred.
The carboxylic acid compound may be either an aromatic carboxylic acid compound or an aliphatic carboxylic acid compound, and examples thereof include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, and halides thereof.
Examples of aromatic hydroxy compounds include (i) polyaddition products of unsaturated aliphatic cyclic compounds containing two double bonds per molecule with phenols, (ii) various bisphenol compounds, (iii) aromatic polyols having two or more hydroxy groups bonded to a carbon atom on an aromatic ring, and (iv) aromatic monools having one hydroxy group bonded to a carbon atom on an aromatic ring. Examples of polyaddition products of unsaturated aliphatic cyclic compounds with phenols include polyaddition products of unsaturated aliphatic cyclic compounds such as dicyclopentadiene, tetrahydroindene, norbornadiene, limonene, and vinylcyclohexene with phenols that may have a substituent (e.g., phenol, cresol, xylenol, ethylphenol, propylphenol, vinylphenol, allylphenol, phenylphenol, benzylphenol, and halophenols), and specific examples thereof include dicyclopentadiene-phenol polyaddition products. Examples of bisphenol compounds include bisphenol A, bisphenol F, bisphenol AF, bisphenol AP, bisphenol B, bisphenol BP, bisphenol C, and bisphenol M. Examples of aromatic polyols having two or more hydroxy groups bonded to carbon atoms on an aromatic ring include hydroquinone, resorcinol, catechol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, benzenetriol, and phenol novolak. Examples of aromatic monools having one hydroxy group bonded to a carbon atom on an aromatic ring include phenol, cresol, xylenol, ethylphenol, propylphenol, vinylphenol, allylphenol, phenylphenol, benzylphenol, halophenols, naphthol, methylnaphthol, dimethylnaphthol, ethylnaphthol, propylnaphthol, vinylnaphthol, allylnaphthol, phenylnaphthol, benzylnaphthol, and halonaphthol.

Specific examples of active ester resins include active ester resins containing a dicyclopentadiene-type diphenol structure, active ester resins containing a naphthalene structure, active ester resins containing an acetylated phenol novolac, and active ester resins containing a benzoylated phenol novolac. Commercially available active ester curing agents include active ester resins containing a dicyclopentadiene-type diphenol structure such as "EXB-9451", "EXB-9460", "EXB-9460S", "HPC-8000-65T", "HPC-8000H-65TM", and "HPC-8000L-65TM" (manufactured by DIC Corporation); active ester resins containing a naphthalene structure such as "EXB-8100L-65T", "EXB-8150-60T", "EXB-8150-62T", "EXB-9416-70BK", "HPC-8150-60T", and "HPC-8150-62T"; Examples include "HP-B-8151-62T" and "HP-C-8151-62T" (manufactured by DIC Corporation); a phosphorus-containing activated ester resin such as "EXB9401" (manufactured by DIC Corporation); an activated ester resin that is an acetylated product of phenol novolac such as "DC808" (manufactured by Mitsubishi Chemical Corporation); activated ester resins that are benzoylated products of phenol novolac such as "YLH1026," "YLH1030," and "YLH1048" (manufactured by Mitsubishi Chemical Corporation); and an activated ester resin containing a styryl group and a naphthalene structure such as "PC1300-02-65MA" (manufactured by Air Water Inc.).

In particular, from the viewpoint of easily achieving a resin composition that satisfies the above-mentioned melt viscosity and storage modulus conditions, it is preferable that the active ester curing agent contains an ethylenically unsaturated bond-containing group. The ethylenically unsaturated bond-containing group is preferably an alkenyl group which may have a substituent, an alkenylaryl group which may have a substituent, or an arylalkenyl group which may have a substituent. From the viewpoint of better enjoying the effects of the present invention, the number of carbon atoms in the alkenyl group is preferably 2 or more or 3 or more, with the upper limit being preferably 10 or less, more preferably 8 or less, 6 or less, or 4 or less. From the viewpoint of better enjoying the effects of the present invention, the number of carbon atoms in the arylalkenyl group or alkenylaryl group is preferably 8 or more, with the upper limit being preferably 20 or less, more preferably 18 or less, 16 or less, 14 or less, or 12 or less. Furthermore, from the viewpoint of better enjoying the effects of the present invention, the substituent is preferably an alkyl group, an alkoxy group, an aryl group, or a hydroxy group, and more preferably an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 14 carbon atoms, or a hydroxy group.

From the viewpoint of better enjoying the effects of the present invention, it is preferable that the active ester curing agent contain two or more ethylenically unsaturated bond-containing groups in the molecule. Furthermore, from the viewpoint of better enjoying the effects of the present invention, the ethylenically unsaturated bond equivalent of the active ester curing agent is preferably 500 g/eq. or less, more preferably 450 g/eq. or less, or 400 g/eq. or less, and the lower limit is preferably 150 g/eq. or more, more preferably 160 g/eq. or more, or 180 g/eq. or more.

As described above, active ester curing agents can be synthesized by reacting a carboxylic acid compound with an aromatic hydroxy compound. However, active ester curing agents containing an ethylenically unsaturated bond-containing group can be synthesized using raw material compounds containing an ethylenically unsaturated bond-containing group. From the viewpoint of easily achieving a resin composition that satisfies the above melt viscosity and storage modulus conditions, it is preferable to synthesize the active ester curing agent using an aromatic monool containing an ethylenically unsaturated bond-containing group, such as a _C2 - _C10 alkenylphenol (vinylphenol, allylphenol, etc.) or a C2-C10 alkenyl naphthol (vinyl naphthol, allyl naphthol, etc.), as the aromatic monool that constitutes the molecular chain terminal structure of the active ester curing agent. Therefore, in a preferred embodiment, the active ester curing agent contains _{an ethylenically unsaturated bond-containing group (preferably a C2-C10 alkenyl - C6 - C14} aryl group) in the molecule (preferably at the molecular chain terminal).

Specific examples of benzoxazine-based curing agents include "JBZ-OD100" (benzoxazine ring equivalent weight 218), "JBZ-OP100D" (benzoxazine ring equivalent weight 218), and "ODA-BOZ" (benzoxazine ring equivalent weight 218) manufactured by JFE Chemical Corporation; "P-d" (benzoxazine ring equivalent weight 217) and "F-a" (benzoxazine ring equivalent weight 217) manufactured by Shikoku Chemicals Corporation; and "HFB2006M" (benzoxazine ring equivalent weight 432) manufactured by Showa Polymer Co., Ltd.

Examples of cyanate ester curing agents include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanate phenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanate phenyl-1-(methylethylidene))benzene, bis(4-cyanate phenyl)thioether, and bis(4-cyanate phenyl)ether; multifunctional cyanate resins derived from phenol novolac and cresol novolac; and prepolymers in which these cyanate resins are partially converted to triazine. Specific examples of cyanate ester curing agents include Lonza Japan's "PT30" and "PT60" (phenol novolac-type multifunctional cyanate ester resins), "ULL-950S" (multifunctional cyanate ester resin), "BA230," and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been triazinated to form a trimer).

Specific examples of carbodiimide-based curing agents include Carbodilite (registered trademark) V-03 (carbodiimide group equivalent: 216 g/eq.), V-05 (carbodiimide group equivalent: 262 g/eq.), and V-07 (carbodiimide group equivalent: 200 g/eq.), all manufactured by Nisshinbo Chemical Inc.; and V-09 (carbodiimide group equivalent: 200 g/eq.), all manufactured by Rhein Chemie; and Stavaxol (registered trademark) P (carbodiimide group equivalent: 302 g/eq.), all manufactured by Rhein Chemie.

When the resin composition of the present invention contains a curing agent, the content of the curing agent in the resin composition is preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, 25% by mass or more, or 30% by mass or more, based on 100% by mass of the resin components in the resin composition. The upper limit of the curing agent content is preferably 70% by mass or less, more preferably 65% by mass or less, 60% by mass or less, or 55% by mass or less.

As mentioned above, from the viewpoint of easily achieving a resin composition that satisfies the above melt viscosity and storage modulus conditions, the curing agent preferably includes one or more curing agents (b1) selected from the group consisting of acid anhydride curing agents and amine curing agents. From the viewpoint of easily achieving the above melt viscosity and storage modulus conditions and more easily enjoying the effects of the present invention, when the total amount of curing agent (non-volatile components) is taken as 100% by mass, the content of curing agent (b1) is preferably 50% by mass or more, more preferably 60% by mass or more, 70% by mass or more, or 80% by mass or more; the upper limit is not particularly limited and may be 100% by mass.

-Curing accelerator-
The resin composition of the present invention preferably contains a curing accelerator.

Examples of curing accelerators include imidazole-based curing accelerators, phosphorus-based curing accelerators, amine-based curing accelerators, guanidine-based curing accelerators, metal-based curing accelerators, and peroxide-based curing accelerators. These curing accelerators may be used alone or in combination of two or more.

In particular, from the viewpoint of realizing a resin composition that exhibits good fluidity during filling and sealing, and from the viewpoint of easily realizing a resin composition that satisfies the above-mentioned melt viscosity and storage modulus conditions, it is preferable that the curing accelerator contains one or more curing accelerators (c1) selected from the group consisting of imidazole-based curing accelerators.

Suitable imidazole-based curing accelerators (c1) include, for example, 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, and 1-benzyl-2-methylimidazole. 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methyl imidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid Examples include imidazole compounds such as acid adducts, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, and 2-phenylimidazoline, as well as adducts of imidazole compounds with epoxy resins.

Commercially available imidazole-based curing accelerators may be used, such as "P200-H50" manufactured by Mitsubishi Chemical Corporation, and "Curezol 2MZ," "2E4MZ," "Cl1Z," "Cl1Z-CN," "Cl1Z-CNS," "Cl1Z-A," "2MZ-OK," "2MA-OK," "2MA-OK-PW," and "2PHZ" manufactured by Shikoku Chemicals Corporation.

The curing accelerator may also include one or more curing accelerators (c2) selected from the group consisting of phosphorus-based curing accelerators, amine-based curing accelerators, guanidine-based curing accelerators, metal-based curing accelerators, and peroxide-based curing accelerators.

Examples of phosphorus-based curing accelerators include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate. Commercially available phosphorus-based curing accelerators may also be used, such as "TBP-DA" manufactured by Hokko Chemical Industry Co., Ltd.

Examples of amine-based curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, 1,8-diazabicyclo(5,4,0)-undecene, 1,8-diazabicyclo[5,4,0]undecene-7,4-dimethylaminopyridine, and 2,4,6-tris(dimethylaminomethyl)phenol.

Examples of guanidine-based curing accelerators include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide.

Metal-based curing accelerators include, for example, organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organocobalt complexes such as cobalt(II) acetylacetonate and cobalt(III) acetylacetonate, organocopper complexes such as copper(II) acetylacetonate, organozinc complexes such as zinc(II) acetylacetonate, organoiron complexes such as iron(III) acetylacetonate, organonickel complexes such as nickel(II) acetylacetonate, and organomanganese complexes such as manganese(II) acetylacetonate. Examples of organometallic salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

When the resin composition of the present invention contains a curing accelerator, the content of the curing accelerator in the resin composition is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, 0.6% by mass or more, 0.8% by mass or more, or 1% by mass or more, based on 100% by mass of the resin components in the resin composition. The upper limit of the content of the curing accelerator is preferably 5% by mass or less, more preferably 4% by mass or less, 3.5% by mass or less, or 3% by mass or less.

As mentioned above, from the viewpoint of easily achieving a resin composition that satisfies the above melt viscosity and storage modulus conditions, the curing accelerator preferably includes one or more curing accelerators (c1) selected from the group consisting of imidazole curing accelerators. From the viewpoint of easily achieving the above melt viscosity and storage modulus conditions and more easily enjoying the effects of the present invention, when the total amount of the curing accelerator (non-volatile components) is taken as 100% by mass, the content of curing accelerator (c1) is preferably 50% by mass or more, more preferably 60% by mass or more, 70% by mass or more, or 80% by mass or more; the upper limit is not particularly limited and may be 100% by mass.

As described above, from the viewpoint of easily realizing a resin composition that satisfies the above melt viscosity condition and storage modulus condition, the resin composition of the present invention preferably contains a curing agent (b1) and a curing accelerator (c1).
one or more curing agents (b1) selected from the group consisting of acid anhydride curing agents and amine curing agents, and one or more curing accelerators (c1) selected from the group consisting of imidazole curing accelerators.
It includes at least one of the following.

As mentioned above, from the viewpoint of easily realizing a resin composition that satisfies the above melt viscosity and storage modulus conditions, the resin composition of the present invention preferably contains a silane compound (a1). Therefore, in a preferred embodiment, the resin composition of the present invention contains a silane compound (a1) and at least one of a curing agent (b1) and a curing accelerator (c1). In such an embodiment, the mass ratio of the total of the curing agent (b1) and the curing accelerator (c1) to the silane compound (a1) [(curing agent (b1) + curing accelerator (c1))/silane compound (a1)] is preferably 1 or greater, more preferably 1.5 or greater, or 2 or greater, and its upper limit is preferably 200 or less, more preferably 180 or less, 160 or less, 140 or less, or 120 or less. For example, when the resin composition of the present invention contains a silane compound (a1) and a curing agent (b1), the mass ratio of the curing agent (b1) to the silane compound (a1) [curing agent (b1)/silane compound (a1)] is preferably 5 or more, more preferably 10 or more, even more preferably 15 or more, 20 or more, 25 or more, or 30 or more, and the upper limit is preferably 200 or less, more preferably 180 or less, 160 or less, 140 or less, or 120 or less. For example, when the resin composition of the present invention contains a silane compound (a1) and a curing accelerator (c1), the mass ratio of the curing accelerator (c1) to the silane compound (a1) [curing accelerator (c1)/silane compound (a1)] is preferably 1 or more, more preferably 1.2 or more, 1.4 or more, or 1.5 or more, and the upper limit is preferably 20 or less, more preferably 15 or less, 10 or less, 8 or less, 6 or less, or 5 or less.

- Stress relief material -
The resin composition of the present invention may contain a stress relaxation material, which is preferable because the inclusion of a stress relaxation material can suppress the occurrence of warpage when a large-area sealing layer is formed in the production of a WLP or PLP, and also makes it easier to realize a resin composition that satisfies the above-mentioned melt viscosity and storage modulus conditions.

The stress relief material is preferably a resin having one or more structures selected from a polybutadiene structure, a polysiloxane structure, a poly(meth)acrylate structure, a polyalkylene structure, a polyalkyleneoxy structure, a polyisoprene structure, a polyisobutylene structure, and a polycarbonate structure within its molecule, and more preferably a resin having one or more structures selected from a polybutadiene structure, a poly(meth)acrylate structure, a polyalkyleneoxy structure, a polyisoprene structure, a polyisobutylene structure, and a polycarbonate structure. The term "(meth)acrylate" encompasses both methacrylate and acrylate. These structures may be contained in the main chain or in the side chain.

The stress relaxation material preferably has a high molecular weight, from the viewpoint of suppressing warping when forming a large-area sealing layer and of easily realizing a resin composition that satisfies the above-mentioned melt viscosity and storage modulus conditions. The number average molecular weight (Mn) of the stress relaxation material is preferably 1,000 or more, more preferably 1,500 or more, and even more preferably 2,000 or more, 2,500 or more, 3,000 or more, 4,000 or more, or 5,000 or more. The upper limit of Mn is preferably 1,000,000 or less, more preferably 900,000 or less, 800,000 or less, or 700,000 or less. The number average molecular weight (Mn) can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

From the perspective of being able to suppress the occurrence of warping when forming a large-area sealing layer and from the perspective of easily realizing a resin composition that preferably satisfies the above-mentioned melt viscosity and storage modulus conditions, the stress relaxation material is preferably one or more types selected from resins with a glass transition temperature (Tg) of 25°C or less and resins that are liquid at 25°C. Here, for resins with multiple observed Tg values, if the lowest Tg is 25°C or less, then the resin falls under the category of "a resin with a Tg of 25°C or less."

For resins with a Tg of 25°C or less, the Tg is preferably 20°C or less, more preferably 15°C or less. There is no particular limit on the lower limit of the Tg, but it can usually be -50°C or higher. Furthermore, for resins that are liquid at 25°C, they are preferably liquid at 20°C or less, more preferably 15°C or less.

The stress relief material preferably has functional groups that can react with epoxy resins, etc., in order to react with the epoxy resins, etc., to produce a cured product with high cohesive strength (interlayer adhesion strength). Note that functional groups that can react with epoxy resins, etc., also include functional groups that appear upon heating.

In a preferred embodiment, the functional group reactive with an epoxy resin or the like is one or more functional groups selected from the group consisting of a hydroxy group, a carboxy group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, and a urethane group. Of these, the functional group is preferably a hydroxy group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, or a urethane group, and more preferably a hydroxy group, an acid anhydride group, a phenolic hydroxyl group, or an epoxy group.

In a preferred embodiment, the stress relief material includes a resin containing a polybutadiene structure (hereinafter also referred to as "polybutadiene resin"). The polybutadiene structure may be partially or completely hydrogenated.

Specific examples of polybutadiene resins include Cray Valley's "Ricon 130MA8," "Ricon 130MA13," "Ricon 130MA20," "Ricon 131MA5," "Ricon 131MA10," "Ricon 131MA17," "Ricon 131MA20," and "Ricon 184MA6" (polybutadienes containing acid anhydride groups); Nippon Soda's "JP-100," "JP-200" (epoxidized polybutadiene), "GQ-1000" (polybutadiene with hydroxyl and carboxyl groups introduced), "G-1000," "G-2000," and "G-3000" (polybutadiene with hydroxyl groups at both ends), "GI-1000," "GI-2000," and "GI-3000" (hydrogenated polybutadiene with hydroxyl groups at both ends); and Daicel. Examples of suitable polybutadiene resins include "PB3600" and "PB4700" (polybutadiene-skeleton epoxy resins), "Epofriend A1005," "Epofriend A1010," and "Epofriend A1020" (epoxidized styrene, butadiene, and styrene block copolymers) manufactured by Nagase ChemteX Corporation, and "FCA-061L" (hydrogenated polybutadiene-skeleton epoxy resin) and "R-45EPT" (polybutadiene-skeleton epoxy resin) manufactured by Nagase ChemteX Corporation. Examples of suitable polybutadiene resins include hydroxyl-terminated polybutadiene, linear polymers derived from diisocyanate compounds and tetrabasic acid anhydrides (polymers described in JP 2006-37083 A and WO 2008/153208 A), and phenolic hydroxyl group-containing butadienes. The content of the butadiene structure in the polymer is preferably 50% by mass or more, and more preferably 60% to 95% by mass. For details of this polymer, please refer to the descriptions in JP 2006-37083 A and WO 2008/153208, the contents of which are incorporated herein by reference.

In a preferred embodiment, the stress relief material contains a resin containing a poly(meth)acrylate structure (hereinafter also referred to as "poly(meth)acrylic resin"). Specific examples of poly(meth)acrylic resins include Nagase ChemteX's Teisan Resin "SG-70L," "SG-708-6," "WS-023," "SG-700AS," and "SG-280TEA" (carboxy group-containing acrylic ester copolymer resin, acid value 5-34 mgKOH/g, weight average molecular weight 400,000-900,000, Tg -30 to 5°C), "SG-80H," "SG-80H-3," and "SG-P3" (epoxy group-containing acrylic ester copolymer resin, epoxy equivalent 4,761-14,285 g/eq, weight average molecular weight 350,000-850,000, Tg 11 to 12°C), and "SG-600T" (carboxy group-containing acrylic ester copolymer resin, epoxy equivalent 4,761-14,285 g/eq, weight average molecular weight 350,000-850,000, Tg 11 to 12°C). Examples include "EA" and "SG-790" (hydroxy group-containing acrylic ester copolymer resin, hydroxyl value 20-40 mgKOH/g, weight average molecular weight 500,000-1,200,000, Tg -37 to -32°C) manufactured by Negami Chemical Industrial Co., Ltd.; "ME-2000" and "W-116.3" (carboxy group-containing acrylic ester copolymer resin), "W-197C" (hydroxy group-containing acrylic ester copolymer resin), "KG-25" and "KG-3000" (epoxy group-containing acrylic ester copolymer resin); and Alphon "UG-4010" (epoxy group-containing acrylic ester copolymer resin) manufactured by Toagosei Co., Ltd.

In a preferred embodiment, the stress relief material includes a resin containing a polycarbonate structure (hereinafter also referred to as "polycarbonate resin"). Specific examples of polycarbonate resins include "T6002" and "T6001" (polycarbonate diols) manufactured by Asahi Kasei Chemicals Corporation, and "C-1090," "C-2090," and "C-3090" (polycarbonate diols) manufactured by Kuraray Co., Ltd. Linear polyimides made from hydroxyl-terminated polycarbonate, diisocyanate compounds, and tetrabasic acid anhydrides can also be used. The carbonate structure content of the polyimide resin is preferably 50% by mass or more, and more preferably 60% to 95% by mass. For details of the polyimide resin, please refer to the description in International Publication No. 2016/129541, the contents of which are incorporated herein by reference.

In a preferred embodiment, the stress relief material includes a resin containing a polysiloxane structure (hereinafter also referred to as "polysiloxane resin"). Specific examples of polysiloxane resins include "SMP-2006," "SMP-2003PGMEA," and "SMP-5005PGMEA" manufactured by Shin-Etsu Silicones Co., Ltd., and linear polyimides made from amine-terminated polysiloxane and tetrabasic acid anhydride (see, for example, International Publication No. 2010/053185, Japanese Patent Application Laid-Open No. 2002-12667, and Japanese Patent Application Laid-Open No. 2000-319386).

In a preferred embodiment, the stress relief material includes a resin containing a polyalkylene structure or a polyalkyleneoxy structure (hereinafter referred to as a "polyalkylene resin" and a "polyalkyleneoxy resin", respectively). Specific examples of polyalkylene resins and polyalkyleneoxy resins include "PTXG-1000" and "PTXG-1800" manufactured by Asahi Kasei Fibers Corporation, monofunctional acrylates "AM-90G", "AM-130G", and "AMP-20GY" manufactured by Shin-Nakamura Chemical Co., Ltd.; bifunctional acrylates "A-1000", "A-1000PER", "A-B1206PE", "A-BPE-20", and "A-BPE-30"; monofunctional methacrylates "M-20G", "M-40G", "M-90G", "M-130G", and "M-230G"; and bifunctional methacrylates "23G", "BPE-900", "BPE-1300N", and "1206PE". Other examples include "Light Ester BC", "Light Ester 041MA", "Light Acrylate EC-A", and "Light Acrylate EHDG-AT" manufactured by Kyoeisha Chemical Co., Ltd.; "FA-023M" manufactured by Hitachi Chemical Co., Ltd.; and Blenmar (registered trademark) "PME-4000", "50POEO-800B", "PLE-200", "PLE-1300", "PSE-1300", and "43PAPE" manufactured by NOF Corporation. -600B", "ANP-300"; Pluronic (registered trademark) manufactured by ADEKA "L-23", "L-31", "L-44", "L-61", "L-62", "L-64", "L-71", "L- 72", "L-101", "L-121", "P-84", "P-85", "P-103", "F-68", "F-88", "F-108", "25R-1", "25R-2", "17R-2", "1 7R-3, 17R-4 (polyoxyethylene polyoxypropylene glycol); Shin-Etsu Silicone Co., Ltd.'s "KF-6011", "KF-6011P", "KF-6012", "KF-6013", "KF-6015", "KF-6016", "KF-6017", "KF-6017P", "KF-6043", "KF-6004", "KF351A", "KF352A", and "KF353"; Examples include "KF354L", "KF355A", "KF615A", "KF945", "KF-640", "KF-642", "KF-643", "KF-644", "KF-6020", "KF-6204", "X22-4515", "KF-6028", "KF-6028P", "KF-6038", "KF-6048", and "KF-6025" (polyoxyalkylene-modified silicone).

In a preferred embodiment, the stress relief material contains a resin containing a polyisoprene structure (hereinafter also referred to as "polyisoprene resin"). Specific examples of polyisoprene resin include "KL-610" and "KL613" manufactured by Kuraray Co., Ltd.

In a preferred embodiment, the stress relief material contains a resin containing a polyisobutylene structure (hereinafter also referred to as "polyisobutylene resin"). Specific examples of polyisobutylene resin include Kaneka Corporation's "SIBSTAR-073T" (styrene-isobutylene-styrene triblock copolymer) and "SIBSTAR-042D" (styrene-isobutylene diblock copolymer).

In another preferred embodiment, the stress relief material includes an organic filler. A wide variety of organic fillers containing a rubber component can be used as the organic filler. Examples of rubber components contained in the organic filler include silicone-based elastomers such as polydimethylsiloxane; olefin-based thermoplastic elastomers such as polybutadiene, polyisoprene, polychlorobutadiene, ethylene-vinyl acetate copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-isobutylene copolymer, acrylonitrile-butadiene copolymer, isoprene-isobutylene copolymer, isobutylene-butadiene copolymer, ethylene-propylene-diene terpolymer, and ethylene-propylene-butene terpolymer; and thermoplastic elastomers such as acrylic thermoplastic elastomers such as polypropyl(meth)acrylate, polybutyl(meth)acrylate, polycyclohexyl(meth)acrylate, and polyoctyl(meth)acrylate. Furthermore, silicone-based rubbers such as polyorganosiloxane rubber may be mixed into the rubber component. The rubber component contained in the rubber particles has a Tg of, for example, 0°C or less, preferably -10°C or less, more preferably -20°C or less, and even more preferably -30°C or less.

In one embodiment, the organic filler is a core-shell type rubber particle consisting of a core particle containing the rubber component listed above and a shell portion formed by graft copolymerization of a monomer component copolymerizable with the rubber component contained in the core particle. Here, core-shell type does not necessarily refer only to particles in which the core particle and shell portion are clearly distinguishable, but also includes particles in which the boundary between the core particle and shell portion is unclear, and the core particle does not necessarily have to be completely covered by the shell portion.

Specific examples of organic fillers containing rubber components include "CHT" manufactured by Cheil Industries; "B602" manufactured by UMGABS; "Paraloid EXL-2602," "Paraloid EXL-2603," "Paraloid EXL-2655," "Paraloid EXL-2311," "Paraloid EXL2313," "Paraloid EXL-2315," "Paraloid KM-330," "Paraloid KM-336P," and "Paraloid KCZ-201" manufactured by Kureha Chemical Industry Co., Ltd.; and "Metabrene C" manufactured by Mitsubishi Rayon Co., Ltd. -223A," "Metablen E-901," "Metablen S-2001," "Metablen W-450A," "Metablen SRK-200," Kaneka Corporation's "Kane Ace M-511," "Kane Ace M-600," "Kane Ace M-400," "Kane Ace M-580," and "Kane Ace MR-01," and Aica Kogyo Co., Ltd.'s "Staphyloid AC3355," "Staphyloid AC3816," "Staphyloid AC3832," "Staphyloid AC4030," and "Staphyloid AC3364." These are core-shell type rubber particles.

When the resin composition of the present invention contains a stress relaxation material, the content of the stress relaxation material in the resin composition, relative to 100% by mass of the resin components in the resin composition, is preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more or 3% by mass or more, and even more preferably 4% by mass or more or 5% by mass or more. The upper limit of the content is preferably 30% by mass or less, more preferably 25% by mass or less, 20% by mass or less, or 15% by mass or less.

-Optional additives-
The resin composition of the present invention may further contain any additives. Examples of such additives include thermosetting resins other than epoxy resins, such as benzocyclobutene resins, epoxy acrylate resins, urethane acrylate resins, urethane resins, cyanate resins, polyimide resins, benzoxazine resins, unsaturated polyester resins, phenolic resins, and melamine resins; radically polymerizable resins, such as maleimide resins, (meth)acrylic resins, and styryl resins; radical polymerization initiators, such as peroxide-based radical polymerization initiators and azo-based radical polymerization initiators; thermoplastic resins, such as phenoxy resins, polyvinyl acetal resins, polysulfone resins, polyethersulfone resins, polyetheretherketone resins, and polyester resins; organic metal compounds, such as organic copper compounds, organic zinc compounds, and organic cobalt compounds; colorants, such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium oxide, and carbon black; polymerization inhibitors, such as hydroquinone, catechol, pyrogallol, and phenothiazine; leveling agents, such as silicone-based leveling agents and acrylic polymer-based leveling agents; and ventilated polymers. thickeners such as silane and montmorillonite; defoaming agents such as silicone-based defoamers, acrylic-based defoamers, fluorine-based defoamers, and vinyl resin-based defoamers; ultraviolet absorbers such as benzotriazole-based ultraviolet absorbers; adhesion improvers such as urea silane; adhesion imparters such as triazole-based adhesion imparters, tetrazole-based adhesion imparters, and triazine-based adhesion imparters; antioxidants such as hindered phenol-based antioxidants; fluorescent brighteners such as stilbene derivatives; surfactants such as fluorine-based surfactants and silicone-based surfactants; phosphorus-based flame retardants (e.g., phosphate ester compounds flame retardants such as methyl acrylate, methyl acrylate, methyl methacrylate, methyl acrylate copolymer, methyl meth ...

- Organic solvents -
The resin composition of the present invention may further contain an organic solvent as a volatile component. Examples of the organic solvent include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, isoamyl acetate, methyl propionate, ethyl propionate, and γ-butyrolactone; ether solvents such as tetrahydropyran, tetrahydrofuran, 1,4-dioxane, diethyl ether, diisopropyl ether, dibutyl ether, and diphenyl ether; alcohol solvents such as methanol, ethanol, propanol, butanol, and ethylene glycol; 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl diglycol acetate, γ-butyrolactone, and methyl methoxypropionate. ether alcohol solvents such as 2-methoxypropanol, 2-methoxyethanol, 2-ethoxyethanol, propylene glycol monomethyl ether, diethylene glycol monobutyl ether (butyl carbitol), and the like; amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, and N-methyl-2-pyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; nitrile solvents such as acetonitrile and propionitrile; aliphatic hydrocarbon solvents such as hexane, cyclopentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, and trimethylbenzene. The organic solvent may be used alone or in combination of two or more.

When the resin composition of the present invention contains an organic solvent, the content of the organic solvent in the resin composition may be determined depending on the properties required of the resin composition, but when all components in the resin composition are taken as 100% by mass, it may be, for example, 20% by mass or less, 15% by mass or less, 10% by mass or less, 5% by mass or less, etc.

The resin composition of the present invention can be prepared by appropriately mixing the necessary components from among the above ingredients, and, if necessary, kneading or mixing them using kneading means such as a triple roll mill, ball mill, bead mill, or sand mill, or stirring means such as a super mixer or planetary mixer.

As mentioned above, the resin composition of the present invention, which satisfies the above melt viscosity and storage modulus conditions, can suppress the occurrence of voids during encapsulation and also suppress the occurrence of cracks after curing, even when it contains a high blend of small-diameter inorganic fillers (e.g., average particle size of 3 μm or less, 2.5 μm or less, 2 μm or less, or 1.5 μm or less).

The resin composition of the present invention, which satisfies the above melt viscosity and storage modulus conditions, achieves both good fluidity and dielectric properties, and can be suitably used as various liquid compounded products that require good fluidity, including low-transmission-loss insulating materials required for 5G applications and the like. For example, the resin composition of the present invention can be suitably used as various liquid compounded products that require good fluidity, including adhesives, casting materials, fiber-reinforced composite materials, semiconductor encapsulation materials, underfill materials, and mold underfill materials. Therefore, in a preferred embodiment, the resin composition of the present invention is used for adhesives, casting materials, fiber-reinforced composite materials, semiconductor encapsulation, underfill, or mold underfill.

In particular, from the viewpoint of being able to fully enjoy the effect of the present invention, namely, achieving both good fluidity and dielectric properties, the resin composition of the present invention can be suitably used as an insulating material for electronic components such as semiconductor packages and printed wiring boards (resin composition for insulating materials for electronic components). For example, the resin composition can be suitably used as a resin composition for encapsulating semiconductor chips (semiconductor encapsulation resin composition), a resin composition for filling the gap between a circuit board (semiconductor package substrate) and a semiconductor chip (underfill resin composition), a resin composition for filling the gap between a circuit board and a semiconductor chip and encapsulating the semiconductor chip (mold underfill resin composition), a resin composition for forming an insulating layer on a printed wiring board (resin composition for printed wiring board insulating layer), or a resin composition for a rewiring formation layer as an insulating layer for forming a rewiring layer in a semiconductor package (resin composition for rewiring formation layer).

The resin composition of the present invention, even when blended with a high content of small-diameter inorganic fillers (e.g., average particle size of 3 μm or less, 2.5 μm or less, 2 μm or less, or 1.5 μm or less), can suppress the occurrence of voids during encapsulation and also suppress the occurrence of cracks after curing. Therefore, it can be preferably used as a resin composition for semiconductor encapsulation, underfill, or mold underfill, and particularly preferably as a resin composition for mold underfill.

The resin composition of the present invention can also be used in a wide range of applications requiring a resin composition, such as resin sheets, sheet-like laminate materials such as prepregs, solder resists, hole-filling resins, and component-embedding resins.

- Sheet-like laminated materials (resin sheets, prepregs) -
The resin composition of the present invention exhibits good fluidity and can therefore be suitably used as a liquid composition, but it may also be used in the form of a sheet-like laminate material containing the resin composition.

The following resin sheets and prepregs are preferred as sheet-like laminate materials.

In one embodiment, the resin sheet includes a support and a layer of a resin composition (hereinafter simply referred to as a "resin composition layer") provided on the support, and is characterized in that the resin composition layer is formed from the resin composition of the present invention.

The optimum thickness of the resin composition layer varies depending on the application, and may be determined appropriately depending on the application. For example, from the perspective of reducing the thickness of printed wiring boards and semiconductor packages, the thickness of the resin composition layer is preferably 400 μm or less, and more preferably 350 μm or less, 300 μm or less, 280 μm or less, 260 μm or less, 240 μm or less, 220 μm or less, or 200 μm or less. The lower limit of the thickness of the resin composition layer is not particularly limited, but can typically be 5 μm or more, 10 μm or more, 20 μm or more, etc.

Examples of the support include thermoplastic resin film, metal foil, and release paper, with thermoplastic resin film and metal foil being preferred. Therefore, in a preferred embodiment, the support is a thermoplastic resin film or metal foil.

When a thermoplastic resin film is used as the support, examples of thermoplastic resins include polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylics such as polycarbonate (PC) and polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, and polyimides. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, with inexpensive polyethylene terephthalate being particularly preferred.

When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. The copper foil may be a foil made of the single metal copper, or a foil made of an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.).

The surface of the support that will be bonded to the resin composition layer may be matte-treated, corona-treated, or antistatic-treated. Alternatively, a support with a release layer, which has a release layer on the surface that will be bonded to the resin composition layer, may be used. Examples of release agents used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. Commercially available support with a release layer may be used, including PET films with a release layer primarily composed of alkyd resin-based release agents, such as "SK-1," "AL-5," and "AL-7" manufactured by Lintec Corporation, "Lumirror T60" manufactured by Toray Industries, Inc., "Purex" manufactured by Teijin Limited, and "Uni-Peel" manufactured by Unitika Limited.

The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 60 μm. When using a support with a release layer, it is preferable that the overall thickness of the support with a release layer be in the above range.

When a metal foil is used as the support, a metal foil with a support substrate may be used, which is a thin metal foil with a peelable support substrate laminated thereto. In one embodiment, the metal foil with a support substrate includes a support substrate, a release layer provided on the support substrate, and a metal foil provided on the release layer. When a metal foil with a support substrate is used as the support, the resin composition layer is provided on the metal foil.

In metal foil with a supporting substrate, the material of the supporting substrate is not particularly limited, but examples include copper foil, aluminum foil, stainless steel foil, titanium foil, copper alloy foil, etc. When copper foil is used as the supporting substrate, it may be electrolytic copper foil or rolled copper foil. In addition, the release layer is not particularly limited as long as it allows the metal foil to be released from the supporting substrate, and examples include an alloy layer of an element selected from the group consisting of Cr, Ni, Co, Fe, Mo, Ti, W, and P; an organic coating, etc.

For metal foil with a supporting substrate, the material of the metal foil is preferably, for example, copper foil or copper alloy foil.

In metal foil with a supporting substrate, the thickness of the supporting substrate is not particularly limited, but is preferably in the range of 10 μm to 150 μm, and more preferably in the range of 10 μm to 100 μm. The thickness of the metal foil may be, for example, in the range of 0.1 μm to 10 μm.

In one embodiment, the resin sheet may further include an optional layer, as needed. Examples of such optional layers include a protective film provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. By laminating a protective film, it is possible to prevent the adhesion of dust and other particles to the surface of the resin composition layer and to prevent scratches.

The resin sheet can be produced, for example, by preparing a resin varnish by dissolving the resin composition in a liquid form in an organic solvent, applying the resin varnish to a support using a die coater or the like, and then drying the applied resin varnish to form a resin composition layer.

The organic solvent may be the same as the organic solvents described as components of the resin composition. One organic solvent may be used alone, or two or more organic solvents may be used in combination.

Drying may be carried out by known methods such as heating or hot air blowing. Drying conditions are not particularly limited, but drying is carried out so that the organic solvent content in the resin composition layer is 10% by mass or less, preferably 5% by mass or less. While this varies depending on the boiling point of the organic solvent in the resin composition or resin varnish, for example, when using a resin composition or resin varnish containing 30% to 60% by mass of organic solvent, a resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

The resin sheet can be stored rolled up. If the resin sheet has a protective film, it can be used by peeling off the protective film.

In one embodiment, the prepreg is formed by impregnating a sheet-like fiber substrate with the resin composition of the present invention.

The sheet-like fiber substrate used for the prepreg is not particularly limited, and commonly used prepreg substrates such as glass cloth, aramid nonwoven fabric, and liquid crystal polymer nonwoven fabric can be used. From the perspective of thinning printed wiring boards and semiconductor packages, the thickness of the sheet-like fiber substrate is preferably 50 μm or less, more preferably 40 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less. There is no particular lower limit to the thickness of the sheet-like fiber substrate. It is usually 10 μm or more.

Prepregs can be manufactured using known methods such as the hot melt method and the solvent method. The thickness of the prepreg can be in the same range as the resin composition layer in the resin sheet described above.

[Semiconductor package]
The semiconductor package of the present invention comprises a cured product of the resin composition of the present invention.

In one embodiment, the semiconductor package of the present invention includes a circuit board, a semiconductor chip mounted on the circuit board, and a cured product of the resin composition of the present invention that encapsulates at least a portion of the semiconductor chip. Hereinafter, this embodiment will also be referred to as the "first embodiment."

In the first embodiment, the circuit board may be a conventionally known circuit board used to form semiconductor packages, and may be manufactured in the same manner as the printed wiring board described below, for example.

The bonding conditions for the circuit board and semiconductor chip can be any conditions that allow for conductive connection between the terminal electrodes of the semiconductor chip and the circuit wiring of the circuit board. For example, the conditions used for flip-chip mounting of semiconductor chips may be used.

One example of a bonding method is to press a semiconductor chip onto a circuit board. The compression temperature is typically in the range of 120°C to 240°C (preferably 130°C to 200°C, more preferably 140°C to 180°C), and the compression time is typically in the range of 1 second to 60 seconds (preferably 5 seconds to 30 seconds). Another example of a bonding method is to place a semiconductor chip on a circuit board and bond it by reflow. Reflow conditions may be in the range of 120°C to 300°C.

After bonding the semiconductor chip to the circuit board, the gap between the semiconductor chip and the circuit board may be filled with an underfill material. As mentioned above, the resin composition of the present invention exhibits good fluidity and is excellent at filling narrow gaps, making it useful as such an underfill material. In such cases, the semiconductor package of the present invention includes an underfill material made from a cured product of the resin composition of the present invention.

Semiconductor chip encapsulation can be performed using a method similar to step (3) in the second embodiment described below. As mentioned above, the resin composition of the present invention exhibits good fluidity and is therefore useful as an encapsulant for such semiconductor chips. In such cases, the semiconductor package of the present invention includes an encapsulant made from a cured product of the resin composition of the present invention.

As mentioned above, the resin composition of the present invention exhibits good fluidity even when it contains a high amount of small-diameter inorganic filler (e.g., average particle size of 3 μm or less, 2.5 μm or less, 2 μm or less, or 1.5 μm or less), and is able to suppress the occurrence of voids during encapsulation and also suppress the occurrence of cracks after curing. Therefore, it can be suitably used as a mold underfill material, and it can fill the gap between a semiconductor chip and a circuit board and encapsulate the semiconductor chip in one step.

When manufacturing a semiconductor package using the resin composition of the present invention, it is preferable to use the resin composition of the present invention as a liquid resin composition, but it may also be used in the form of a sheet-like laminate material as described above.

In another embodiment (hereinafter also referred to as "second embodiment"), the semiconductor chip package of the present invention can be manufactured, for example, by a method including the following steps (1) to (6) using the resin composition of the present invention. The resin composition of the present invention can be used to form the encapsulating layer in step (3) or the rewiring formation layer in step (5). An example of forming the encapsulating layer or rewiring formation layer using the resin composition will be shown below. However, techniques for forming the encapsulating layer or rewiring formation layer of a semiconductor chip package are known, and a person skilled in the art can manufacture a semiconductor chip package using the resin composition of the present invention according to known techniques.
(1) A step of laminating a temporary fixing film on a substrate;
(2) A step of temporarily fixing a semiconductor chip on a temporary fixing film;
(3) forming an encapsulation layer on the semiconductor chip;
(4) peeling the substrate and the temporary fixing film from the semiconductor chip;
(5) forming a rewiring formation layer as an insulating layer on the surface of the semiconductor chip from which the base material and the temporary fixing film have been peeled off; and (6) forming a rewiring layer as a conductor layer on the rewiring formation layer.

-Process (1)-
The material used for the substrate is not particularly limited, and examples of the substrate include a silicon wafer, a glass wafer, a glass substrate, a metal substrate such as copper, titanium, stainless steel, or cold-rolled steel plate (SPCC), a substrate in which glass fiber is impregnated with epoxy resin or the like and subjected to a thermosetting treatment (e.g., an FR-4 substrate), and a substrate made of bismaleimide triazine resin (BT resin).

The material of the temporary fixing film is not particularly limited as long as it can be peeled off from the semiconductor chip in step (4) and can temporarily fix the semiconductor chip. Commercially available temporary fixing films can be used. Examples of commercially available products include Riva Alpha manufactured by Nitto Denko Corporation.

-Process (2)-
The semiconductor chip is temporarily fixed on the temporary fixing film so that its electrode pad surface is bonded to the temporary fixing film. The temporary fixing of the semiconductor chip can be performed using a known device such as a flip chip bonder or a die bonder. The layout and number of semiconductor chips to be arranged can be appropriately set depending on the shape and size of the temporary fixing film, the number of semiconductor packages to be produced, etc., and for example, the semiconductor chips can be temporarily fixed by arranging them in a matrix of multiple rows and multiple columns.

-Process (3)-
The resin composition of the present invention may be applied as a liquid composition onto a semiconductor chip and cured (for example, by heat curing) to form an encapsulating layer. Alternatively, the resin composition of the present invention may be laminated on a semiconductor chip in the form of the above-mentioned resin sheet and cured (for example, by heat curing) to form an encapsulating layer.

By using the resin composition of the present invention that satisfies the above melt viscosity and storage modulus conditions, it is possible to suppress the occurrence of voids during sealing and also to suppress the occurrence of cracks after curing, whether the resin composition is applied as a liquid composition or whether the resin composition layer is laminated in the form of a resin sheet.

When used in the form of a resin sheet, the semiconductor chip and resin sheet can be laminated by removing the protective film from the resin sheet and then heat-pressing the resin sheet onto the semiconductor chip from the support side. The semiconductor chip and resin sheet can also be laminated using a vacuum lamination method, and the lamination conditions and preferred ranges are the same as those described below in connection with the method for manufacturing a printed wiring board.

After lamination, the resin composition is thermally cured to form the sealing layer. The thermal curing conditions are the same as those described below in connection with the method for manufacturing a printed wiring board.

The support for the resin sheet may be peeled off after the resin sheet is laminated on the semiconductor chip and thermally cured, or the support may be peeled off before the resin sheet is laminated on the semiconductor chip.

When the resin composition of the present invention is applied as a liquid composition to form a sealing layer, the application conditions may be the same as those for forming the resin composition layer described in relation to the resin sheet of the present invention. By using the resin composition of the present invention, good fluidity can be achieved at application and molding temperatures.

-Process (4)-
The method for peeling off the substrate and the temporary fixing film can be changed as appropriate depending on the material of the temporary fixing film, etc., and examples include a method in which the temporary fixing film is heated and foamed (or expanded) to peel it off, and a method in which ultraviolet light is irradiated from the substrate side to reduce the adhesive strength of the temporary fixing film and peel it off.

In the method of peeling off the temporary fixing film by heating and foaming (or expanding) it, the heating conditions are usually 100 to 250° C. for 1 to 90 seconds or 5 to 15 minutes. In the method of peeling off the temporary fixing film by irradiating it with ultraviolet light from the substrate side to reduce the adhesive strength of the temporary fixing film, the irradiation dose of ultraviolet light is usually 10 mJ/cm ² to 1000 mJ/cm ² .

-Process (5)-
The material for forming the rewiring formation layer (insulating layer) is not particularly limited as long as it has insulating properties when the rewiring formation layer (insulating layer) is formed, and from the viewpoint of ease of manufacturing a semiconductor package, a photosensitive resin or a thermosetting resin is preferred. The rewiring formation layer may be formed using the resin composition of the present invention.

After forming the redistribution layer, via holes may be formed in the redistribution layer to establish interlayer connections between the semiconductor chip and the conductor layer described below. The via holes may be formed using known methods depending on the material of the redistribution layer.

-Process (6)-
The material of the conductor layer formed on the redistribution layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductor layer may be a single metal layer or an alloy layer. Examples of the alloy layer include a layer formed from an alloy of two or more metals selected from the above group (e.g., a nickel-chromium alloy, a copper-nickel alloy, and a copper-titanium alloy). Among these, from the viewpoints of versatility, cost, ease of patterning, etc., of the conductor layer formation, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy, a copper-nickel alloy, or a copper-titanium alloy is preferred. A single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy is more preferred, and a single metal layer of copper is even more preferred.

The conductor layer may have a single-layer structure, or a multi-layer structure consisting of two or more single-metal or alloy layers made of different types of metals or alloys. If the conductor layer has a multi-layer structure, the layer in contact with the insulating layer is preferably a single-metal layer of chromium, zinc, or titanium, or an alloy layer of nickel-chromium alloy.

The thickness of the conductor layer depends on the desired semiconductor chip package design, but is generally between 1 μm and 35 μm, preferably between 1 μm and 20 μm.

In one embodiment, the conductor layer may be formed by plating. For example, a conductor layer having the desired wiring pattern can be formed by plating the surface of the rewiring formation layer using conventional techniques such as semi-additive and full-additive methods. From the perspective of ease of manufacturing, formation by a semi-additive method is preferred. Below is an example of forming a conductor layer by a semi-additive method.

First, a plating seed layer is formed on the surface of the rewiring formation layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer, exposing a portion of the plating seed layer corresponding to the desired wiring pattern. A metal layer is formed on the exposed plating seed layer by electrolytic plating, and the mask pattern is then removed. Unnecessary plating seed layer is then removed by etching or other methods, forming a conductor layer (rewiring layer) with the desired wiring pattern.

In addition, steps (5) and (6) may be repeated to alternately stack (build up) conductor layers (rewiring layers) and rewiring formation layers (insulating layers).

When manufacturing a semiconductor chip package, the following steps may be further performed: (7) forming a solder resist layer on the conductor layer (rewiring layer), (8) forming bumps, and (9) dicing multiple semiconductor chip packages into individual semiconductor chip packages. These steps may be performed according to various methods known to those skilled in the art that are used in the manufacture of semiconductor chip packages.

The second embodiment described above is an example of a method for manufacturing a semiconductor package using a chip-1st (Chip- ^1st ) method, in which a semiconductor chip is first provided and a rewiring layer is formed on the electrode pad surface of the chip. In addition to the chip-1st method, the semiconductor package of the present invention may also be manufactured using a rewiring layer-1st (RDL- ^1st ) method, in which a rewiring layer is first provided, a semiconductor chip is provided on the rewiring layer in a state in which the electrode pad surface can be electrically connected to the rewiring layer, and then the semiconductor chip is sealed. The resin composition of the present invention, which has excellent filling properties, can realize a ^{semiconductor} package with extremely low transmission loss, which is required for 5G applications, without the occurrence of voids or cracks, regardless of whether the chip- ^1st method or the RDL-1st method is used.

By using the resin composition of the present invention to form an encapsulating layer, a rewiring formation layer, etc., it is possible to realize a semiconductor package with extremely low transmission loss while suppressing the occurrence of flow marks and voids, regardless of whether the semiconductor package is a fan-in package or a fan-out package. In one embodiment, the semiconductor chip package of the present invention is a fan-out package. The resin composition of the present invention can be applied to both fan-out panel level packages (FOPLPs) and fan-out wafer level packages (FOWLPs). In one embodiment, the semiconductor package of the present invention is a fan-out panel level package (FOPLP). In another embodiment, the semiconductor package of the present invention is a fan-out wafer level package (FOWLP).

[Printed wiring board]
A printed wiring board can be produced using the resin composition of the present invention. The present invention also provides such a printed wiring board. The printed wiring board of the present invention is characterized by including an insulating layer made of a cured product of the resin composition of the present invention.

The printed wiring board can be produced, for example, by using the above-mentioned resin sheet by a method including the following steps (I) and (II).
(I) a step of laminating a resin sheet on an inner layer substrate so that the resin composition layer of the resin sheet is bonded to the inner layer substrate; and (II) a step of curing (e.g., thermally curing) the resin composition layer to form an insulating layer.

The "inner layer substrate" used in step (I) refers to a component that will become the substrate of a printed wiring board, and examples include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The substrate may also have a conductor layer on one or both sides, and this conductor layer may be patterned. An inner layer substrate with a conductor layer (circuit) formed on one or both sides of the substrate is sometimes referred to as an "inner layer circuit board." Furthermore, the term "inner layer substrate" used in this invention also includes intermediate products on which insulating layers and/or conductor layers are to be further formed during the manufacture of a printed wiring board. When the printed wiring board is a component-embedded circuit board, an inner layer substrate with embedded components may be used.

The inner layer substrate and resin sheet can be laminated, for example, by thermocompression bonding the resin sheet to the inner layer substrate from the support side. Examples of the member that thermocompresses the resin sheet to the inner layer substrate (hereinafter also referred to as the "thermocompression member") include a heated metal plate (such as a SUS panel) or a metal roll (SUS roll). The thermocompression member may be pressed directly onto the resin sheet, or it may be pressed via an elastic material such as heat-resistant rubber so that the resin sheet can adequately conform to the surface irregularities of the inner layer substrate.

The lamination of the inner layer substrate and the resin sheet may be carried out by vacuum lamination. In vacuum lamination, the thermocompression temperature is preferably in the range of 60°C to 160°C, more preferably 80°C to 140°C, the thermocompression pressure is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably 0.29 MPa to 1.47 MPa, and the thermocompression time is preferably in the range of 20 seconds to 400 seconds, more preferably 30 seconds to 300 seconds. Lamination is preferably carried out under reduced pressure conditions of 26.7 hPa or less.

Lamination can be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include the vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., the vacuum applicator manufactured by Nikko Materials Co., Ltd., and the batch vacuum pressure laminator.

After lamination, the laminated resin sheets may be smoothed under normal pressure (atmospheric pressure), for example, by pressing a thermocompression member from the support side. The pressing conditions for the smoothing process may be the same as the thermocompression conditions for lamination described above. The smoothing process may be performed using a commercially available laminator. Note that lamination and smoothing may also be performed consecutively using the commercially available vacuum laminator described above.

The support may be removed between step (I) and step (II), or after step (II). When a metal foil is used as the support, the conductor layer may be formed using the metal foil without peeling off the support. When a metal foil with a supporting substrate is used as the support, the supporting substrate (and release layer) may be peeled off. Then, the conductor layer may be formed using the metal foil.

In step (II), the resin composition layer is cured (e.g., thermally cured) to form an insulating layer made of the cured resin composition. The curing conditions for the resin composition layer are not particularly limited, and conditions typically used for forming insulating layers for printed wiring boards may be used.

For example, the thermal curing conditions for the resin composition layer vary depending on the type of resin composition, but in one embodiment, the curing temperature is preferably 120°C to 250°C, more preferably 150°C to 240°C, and even more preferably 180°C to 230°C. The curing time is preferably 5 minutes to 240 minutes, more preferably 10 minutes to 150 minutes, and even more preferably 15 minutes to 120 minutes.

Before thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature of 50°C to 120°C, preferably 60°C to 115°C, and more preferably 70°C to 110°C for 5 minutes or more, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes.

When manufacturing a printed wiring board, the following steps may be further carried out: (III) drilling holes in the insulating layer; (IV) roughening the insulating layer; and (V) forming a conductor layer. These steps (III) through (V) may be carried out according to various methods known to those skilled in the art and used in the manufacture of printed wiring boards. If the support is removed after step (II), the removal of the support may be carried out between steps (II) and (III), between steps (III) and (IV), or between steps (IV) and (V). Furthermore, if necessary, the formation of the insulating layer and conductor layer in steps (I) through (V) may be repeated to form a multilayer wiring board.

In another embodiment, a printed wiring board can be manufactured using the prepreg described above. The manufacturing method is basically the same as when using a resin sheet.

Step (III) is a step of drilling holes in the insulating layer, thereby forming holes such as via holes and through holes in the insulating layer. Step (III) may be performed using, for example, a drill, laser, plasma, etc., depending on the composition of the resin composition used to form the insulating layer. The dimensions and shape of the holes may be determined appropriately depending on the design of the printed wiring board.

Step (IV) is a step in which the insulating layer is roughened. Typically, smear removal (desmearing) is also performed in this step (IV). The roughening treatment procedures and conditions are not particularly limited, and known procedures and conditions commonly used in forming insulating layers for printed wiring boards can be used. For example, the insulating layer can be roughened by performing a swelling treatment using a swelling liquid, a roughening treatment using an oxidizing agent, and a neutralization treatment using a neutralizing liquid, in that order.

The swelling liquid used in the roughening treatment is not particularly limited, but examples include alkaline solutions and surfactant solutions. Alkaline solutions are preferred, with sodium hydroxide and potassium hydroxide solutions being more preferred. Commercially available swelling liquids include "Swelling Dip Securigans P" and "Swelling Dip Securigans SBU" manufactured by Atotech Japan. The swelling treatment using a swelling liquid is not particularly limited, but can be carried out by immersing the insulating layer in a swelling liquid at 30°C to 90°C for 1 to 20 minutes, for example. To keep swelling of the resin in the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling liquid at 40°C to 80°C for 5 to 15 minutes.

The oxidizing agent used in the roughening treatment is not particularly limited, but examples include alkaline permanganate solutions prepared by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. Roughening treatment using an oxidizing agent such as alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% to 10% by mass. Commercially available oxidizing agents include alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigance P" manufactured by Atotech Japan.

The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and a commercially available product such as "Reduction Solution Securigant P" manufactured by Atotech Japan is one example.

Treatment with a neutralizing solution can be carried out by immersing the surface that has been roughened with an oxidizing agent in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the standpoint of workability, etc., it is preferable to immerse the object that has been roughened with an oxidizing agent in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

Step (V) is a step of forming a conductor layer on an insulating layer. Step (V) may be performed in the same manner as step (6) described in relation to the method for manufacturing a semiconductor chip package.

The thickness of the conductor layer depends on the desired printed wiring board design, but is generally between 3 μm and 35 μm, preferably between 5 μm and 30 μm.

The conductor layer may also be formed using metal foil. When forming the conductor layer using metal foil, it is preferable to perform step (V) between steps (I) and (II). For example, after step (I), the support is removed and metal foil is laminated on the exposed surface of the resin composition layer. The resin composition layer and metal foil may be laminated using a vacuum lamination method. The lamination conditions may be the same as those described for step (I). Next, step (II) is performed to form an insulating layer. Thereafter, a conductor layer having the desired wiring pattern can be formed using the metal foil on the insulating layer using conventional techniques such as a subtractive method or a modified semi-additive method.

Metal foil can be manufactured by known methods such as electrolysis and rolling. Commercially available metal foils include HLP foil and JXUT-III foil manufactured by JX Nippon Mining & Metals Corporation, and 3EC-III foil and TP-III foil manufactured by Mitsui Mining & Smelting Co., Ltd.

Alternatively, as mentioned above, if a metal foil or a metal foil with a supporting substrate is used as the support for the resin sheet, the conductor layer may be formed using the metal foil.

[Semiconductor device]
The semiconductor device of the present invention includes a layer made of a cured product of the resin composition of the present invention. The semiconductor device of the present invention can be produced using the semiconductor package or printed wiring board of the present invention.

Semiconductor devices include various semiconductor devices used in electrical appliances (e.g., computers, mobile phones, digital cameras, and televisions) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft).

The present invention will be explained in more detail below using examples. The present invention is not limited to these examples. In the following, "parts" and "%" used to express amounts mean "parts by mass" and "% by mass," respectively, unless otherwise specified.

<Inorganic filler used>
Inorganic filler 1: average particle size 1.7 μm, top cut 5 μm, specific surface area 3.7 m ² /g, treated with a silane compound ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd., N-phenyl-3-aminopropyltrimethoxysilane).
Inorganic filler 2: average particle size 0.5 μm, top cut 3 μm, specific surface area 7.0 m ² /g, treated with a silane compound ("KBM573" manufactured by Shin-Etsu Chemical Co., Ltd., N-phenyl-3-aminopropyltrimethoxysilane).

Synthesis Example 1 (Synthesis of Active Ester Compound A)
A reaction vessel was charged with 201 parts by mass of ortho-allylphenol and 1,000 parts by mass of toluene, and the contents were dissolved while the vessel was purged with nitrogen under reduced pressure. Subsequently, 152 parts by mass of isophthalic acid chloride was charged and dissolved. While purging the vessel with nitrogen, 309 g of a 20% aqueous sodium hydroxide solution was added dropwise over 3 hours. The temperature in the system was controlled to 60°C or less. The mixture was then stirred for 1 hour to react. After the reaction was completed, the reaction mixture was separated and the aqueous layer was removed. This operation was repeated until the pH of the aqueous layer reached 7, and toluene and the like were distilled off under heating and reduced pressure conditions, yielding an active ester compound A. The ethylenically unsaturated bond equivalent of the resulting active ester compound A was calculated from the charge ratio to be 199 g/eq.

Example 1
Naphthalene type epoxy resin (DIC Corporation "HP4032D", epoxy equivalent 140 g/eq.) 4 parts, epoxy resin mixture (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, Nippon Steel Chemical & Material Co., Ltd. "ZX-1059", epoxy equivalent 170 g/eq.) 3 parts, resin having a methacryloyl group and a polyethylene oxide structure (Shin-Nakamura Chemical Co., Ltd. "BPE-1300N") 4 parts, inorganic filler 1 A resin composition was obtained by blending 90 parts of a hydroxybenzoate, 10 parts of an acid anhydride curing agent ("HNA-100" manufactured by New Japan Chemical Co., Ltd., acid anhydride equivalent 179 g/eq.), 0.5 parts of an imidazole curing accelerator ("2MA-OK-PW" manufactured by Shikoku Chemical Industry Co., Ltd.), 0.1 parts of a silane compound ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd., 3-glycidoxypropyltrimethoxysilane), and 0.1 parts of a silane compound ("KBM-202SS" manufactured by Shin-Etsu Chemical Co., Ltd., diphenyldimethoxysilane), and dispersing the mixture uniformly in a mixer.

Example 2
A resin composition was obtained in the same manner as in Example 1, except that the amount of the silane compound ("KBM-202SS") was changed from 0.1 part to 0.3 part.

Example 3
Naphthalene type epoxy resin (DIC Corporation "HP4032D", epoxy equivalent 140 g/eq.) 3 parts, epoxy resin mixture (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, Nippon Steel Chemical & Material Co., Ltd. "ZX-1059", epoxy equivalent 170 g/eq.) 5 parts, glycidylamine type epoxy resin (Mitsubishi Chemical Corporation "JER630LSD", epoxy equivalent 95 g/eq.) 2 parts, polyoxyethylene polyoxypropylene glycol (ADEKA Corporation "L-64") 1.5 parts, inorganic filler 1 A resin composition was obtained by blending 75 parts of a methyl acrylate acrylate copolymer, 4 parts of an amine curing agent ("Kayahard A-A" manufactured by Nippon Kayaku Co., Ltd.), 0.4 parts of an imidazole curing accelerator ("2E4MZ" manufactured by Shikoku Kasei Co., Ltd.), 0.1 parts of a silane compound ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd., 3-glycidoxypropyltrimethoxysilane), and 0.15 parts of a silane compound ("KBM-202SS" manufactured by Shin-Etsu Chemical Co., Ltd., diphenyldimethoxysilane), and uniformly dispersing the mixture in a mixer.

Example 4
Naphthalene type epoxy resin (DIC Corporation "HP4032D", epoxy equivalent 140 g/eq.) 5 parts, epoxy resin mixture (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, Nippon Steel Chemical & Material Co., Ltd. "ZX-1059", epoxy equivalent 170 g/eq.) 5 parts, glycidylamine type epoxy resin (Mitsubishi Chemical Corporation "JER630LSD", epoxy equivalent 95 g/eq.) 4 parts, polyoxyethylene polyoxypropylene glycol (ADEKA Corporation "L-64") 1.5 parts, inorganic filler 1 A resin composition was obtained by blending 60 parts of a silane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-403", 0.2 parts of an imidazole curing accelerator (manufactured by Shikoku Chemical Co., Ltd., "2E4MZ"), 0.1 parts of a silane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-202SS", diphenyldimethoxysilane), and uniformly dispersing the blend in a mixer.

Example 5
Naphthalene type epoxy resin ("HP4032D" manufactured by DIC Corporation, epoxy equivalent 140 g/eq.) 4 parts, epoxy resin mixture (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, "ZX-1059" manufactured by Nippon Steel Chemical & Material Co., Ltd., epoxy equivalent 170 g/eq.) 3 parts, glycidylamine type epoxy resin ("JER630LSD" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 95 g/eq.) 4 parts, inorganic filler 1 85 parts, acid anhydride type curing agent ("HNA-100" manufactured by New Japan Chemical Co., Ltd., acid anhydride equivalent 179 g/eq.) 8 parts, active ester compound A A resin composition was obtained by blending 0.5 parts of a silane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-403", 3-glycidoxypropyltrimethoxysilane), 0.1 parts of a silane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-202SS", diphenyldimethoxysilane), and uniformly dispersing the blend in a mixer.

Example 6
A resin composition was obtained in the same manner as in Example 2, except that 0.5 parts of a polyoxyalkylene-modified silicone resin ("KF-6012" manufactured by Shin-Etsu Silicones Co., Ltd.) was used instead of 4 parts of a resin having a methacryloyl group and a polyethylene oxide structure ("BPE-1300N").

Example 7
A resin composition was obtained in the same manner as in Example 2, except that 1 part of an epoxidized polybutadiene resin ("JP100" manufactured by Nippon Soda Co., Ltd.) was used instead of 4 parts of a resin having a methacryloyl group and a polyethylene oxide structure ("BPE-1300N").

Example 8
A resin composition was obtained in the same manner as in Example 2, except that 1 part of an epoxidized acrylic resin (manufactured by Toa Gosei Co., Ltd., "UG-4010") was used instead of 4 parts of a resin having a methacryloyl group and a polyethylene oxide structure ("BPE-1300N").

Example 9
Naphthalene type epoxy resin (DIC Corporation "HP4032D", epoxy equivalent 140 g/eq.) 4 parts, epoxy resin mixture (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin, Nippon Steel Chemical & Material Co., Ltd. "ZX-1059", epoxy equivalent 170 g/eq.) 7 parts, resin having a methacryloyl group and a polyethylene oxide structure (Shin-Nakamura Chemical Co., Ltd. "BPE-1300N") 3 parts, inorganic filler 2 A resin composition was obtained by blending 80 parts of a hydroxybenzoate, 6 parts of an acid anhydride curing agent ("HNA-100" manufactured by New Japan Chemical Co., Ltd., acid anhydride equivalent 179 g/eq.), 0.5 parts of an imidazole curing accelerator ("2MA-OK-PW" manufactured by Shikoku Chemical Industry Co., Ltd.), 0.1 parts of a silane compound ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd., 3-glycidoxypropyltrimethoxysilane), and 0.1 parts of a silane compound ("KBM-202SS" manufactured by Shin-Etsu Chemical Co., Ltd., diphenyldimethoxysilane) and dispersing the mixture uniformly in a mixer.

<Comparative Example 1>
A resin composition was obtained in the same manner as in Example 3, except that (1) a silane compound ("KBM-202SS") was not used, (2) an amine-based curing agent ("Kayahard A-A") was not used, and (3) the amount of polyoxyethylene polyoxypropylene glycol ("L-64") added was changed from 1.5 parts to 3 parts.

<Comparative Example 2>
A resin composition was obtained in the same manner as in Example 1, except that (1) no silane compound ("KBM-202SS") was used, and (2) 0.5 parts of a phosphorus-based curing accelerator ("TBP-DA" manufactured by Hokko Chemical Industry Co., Ltd.) was used instead of 0.5 parts of the imidazole-based curing accelerator ("2MA-OK-PW").

Details of the resin compositions prepared in Examples 1 to 9 and Comparative Examples 1 and 2 are shown in Table 1.

<Measurement of Melt Viscosity>
The melt viscosity of the resin compositions prepared in the examples and comparative examples was measured using a dynamic viscoelasticity measuring device (Rheosol-G3000 manufactured by U.B.M. Co., Ltd.). Specifically, a 1 g sample taken from the resin composition was measured in time-dependent mode using parallel plates with a diameter of 18 mm. The measurement conditions were a constant temperature of 120°C, a step time of 5 seconds, strain control of 1 degree, and a frequency of 1 Hz. The initial (at the start of measurement) melt viscosity MV1 (Pa s) and the melt viscosity MV2 (Pa s) 2 minutes after the start of measurement were then measured.

<Measurement of Tg and storage modulus>
The resin compositions prepared in the Examples and Comparative Examples were compression molded onto a release-treated 12-inch silicon wafer using a compression molding device (mold temperature: 130°C, pressure: 6 MPa, cure time: 10 minutes) to form a resin composition layer with a thickness of 300 μm. Thereafter, the resin composition was peeled off from the release-treated silicon wafer and heated at 180°C for 90 minutes to thermally cure the resin composition, thereby producing a cured product sample.
The cured product samples were then cut into test pieces measuring 7 mm wide and 40 mm long, and dynamic mechanical analysis was performed in tension mode using a dynamic mechanical analyzer (Seiko Instruments Inc., "DMS-6100"). After mounting the test pieces in the analyzer, measurements were performed at a frequency of 1 Hz and a heating rate of 5°C/min. In these measurements, the storage modulus SM1(E'; GPa) at 23°C was recorded, and the temperature showing the maximum value of the peak of tan δ (= loss modulus E"/storage modulus E') was also recorded as Tg. Furthermore, the storage modulus SM2(E'; GPa) at temperature T (°C) was recorded. Here, temperature T was Tg - 30 (°C), where Tg (°C) is the glass transition temperature of each cured product.

<Test Example 1: Mold Underfill (MUF) Test>
A chip component with copper bumps ("WALTS-TEG FBW40A-000 1JY" manufactured by Waltz Corporation, chip size 10 mm × 10 mm, chip thickness 300 μm, copper bump size diameter 20 μm, height 30 μm, copper bump pitch 40 μm) was mounted on a 12-inch glass wafer with a thickness of 775 μm using an adhesive at the four corners so that the glass wafer and the copper bumps were in contact with each other.
Next, the resin compositions prepared in the examples and comparative examples were compression molded using a compression molding machine (mold temperature: 130°C, pressure: 6 MPa, cure time: 10 minutes) to a resin thickness of 400 μm, thereby forming mold underfill (MUF) on the chip components. The resin compositions were heated at 150°C for 60 minutes to be thermally cured, and then the presence or absence of voids was observed using a microscope from the back of the glass wafer. The results were evaluated according to the following criteria.

Evaluation criteria:
◯: Resin was filled between the bumps and no voids were observed.
x: There were portions between the bumps where the resin was not filled, and voids and unfilled portions were observed.

<Test Example 2: Thermal Cycle Test>
A chip component with copper bumps ("WALTS-TEG FBW40A-000 1JY" manufactured by Waltz Corporation, chip size 10 mm × 10 mm, chip thickness 300 μm, copper bump size diameter 20 μm, height 30 μm, copper bump pitch 40 μm) was mounted on a 12-inch silicon wafer with a thickness of 775 μm using an adhesive at the four corners so that the silicon wafer and copper bumps were in contact with each other.
Next, the resin compositions prepared in the examples and comparative examples were compression molded using a compression molding machine (mold temperature: 130°C, pressure: 6 MPa, cure time: 10 minutes) to a resin thickness of 400 μm, thereby forming mold underfill (MUF) on the chip components. The resin compositions were then heated at 150°C for 60 minutes to be thermally cured, and then subjected to a thermal cycle test (-55°C to 125°C, 500 cycles). Evaluation was then performed according to the following criteria.

Evaluation criteria:
Good: No delamination of the chip component or cracks in the resin occurred after the test.
×: After the test, delamination of the chip component or cracks in the resin occurred.

The physical properties and evaluation results of Examples 1 to 9 and Comparative Examples 1 and 2 are shown in Table 2.

Claims (17)

A resin composition comprising an epoxy resin, an inorganic filler, and a silane compound,
the content of the epoxy resin is 5% by mass or more and 90% by mass or less, when the resin component in the resin composition is 100% by mass;
A resin composition that satisfies the following melt viscosity and storage modulus conditions.
<Melt viscosity conditions>
When the melt viscosity is measured at 120°C, the initial melt viscosity is MV1 (Pa s), and the melt viscosity after 2 minutes is MV2 (Pa s).
MV2/MV1≦10 and MV2≦3000
is.
<Storage modulus conditions>
When the storage modulus of the cured product obtained by heating the resin composition at 150°C for 60 minutes is SM1 (GPa) at 23°C and the storage modulus of the cured product at temperature T is SM2 (GPa),
0.4<SM2/SM1 ≦1
Here, the temperature T is Tg-30 (°C), where Tg (°C) is the glass transition temperature of the cured product. The resin composition according to claim 1, comprising a silane compound (a1) represented by the following formula (A-1):
(RO) _n SiAr _4-n (A-1)
(In the formula, R represents an alkyl group, Ar represents an aryl group which may have a substituent, and n represents 1 or 2.) one or more curing agents (b1) selected from acid anhydride curing agents and amine curing agents, and one or more curing accelerators (c1) selected from imidazole curing accelerators.
The resin composition according to claim 1, comprising at least one of the following: one or more curing agents (b1) selected from acid anhydride curing agents and amine curing agents, and one or more curing accelerators (c1) selected from imidazole curing accelerators.
The resin composition according to claim 2, comprising at least one of the following: The resin composition according to claim 2, further comprising another silane compound (a2) different from the silane compound (a1) . The resin composition according to claim 4, wherein the mass ratio of the total of the curing agent (b1) and the curing accelerator (c1) to the silane compound (a1) [(curing agent (b1) + curing accelerator (c1)) / silane compound (a1)] is 1 or more. The resin composition according to claim 5, wherein the mass ratio of silane compound (a2) to silane compound (a1) (silane compound (a2)/silane compound (a1)) is 0.1 or more. The resin composition according to claim 1, containing an inorganic filler having an average particle size of 3 μm or less. The resin composition according to claim 1, wherein the content of the inorganic filler is 50% by mass or more when the total amount of nonvolatile components in the resin composition is 100% by mass. The resin composition according to claim 1, containing a stress relaxation agent. The resin composition according to claim 10, wherein the stress relaxation agent is a resin having, in its molecule, one or more structures selected from a polybutadiene structure, a polysiloxane structure, a poly(meth)acrylate structure, a polyalkylene structure, a polyalkyleneoxy structure, a polyisoprene structure, a polyisobutylene structure, and a polycarbonate structure. 2. The resin composition according to claim 1, wherein the glass transition temperature Tg of a cured product obtained by heating the resin composition at 150°C for 60 minutes is 140°C or higher. The resin composition according to claim 1, which is used for mold underfill. A cured product of the resin composition according to any one of claims 1 to 13 . A semiconductor package comprising a cured product of the resin composition according to any one of claims 1 to 13 . 16. The semiconductor package according to claim 15 , which is a fan-out type package. A semiconductor device comprising a cured product of the resin composition according to any one of claims 1 to 13 .