JP7581662B2 - Highly dielectric resin composition, carrier-attached resin film, prepreg, laminate, printed wiring board and semiconductor device each using the same - Google Patents

Description

The present invention relates to a high dielectric resin composition, and a resin film with a carrier, a prepreg, a laminate, a printed wiring board, and a semiconductor device that use the same.

As communication information becomes larger and more diverse, communication speeds are increasing for printed circuit boards for communication base stations, servers, routers, and the like. In order to keep up with the increased communication speeds, it is necessary to increase the frequency of signals.

Reducing transmission loss is important to ensure signal quality. Transmission loss is mainly caused by dielectric loss due to the resin and conductor loss due to the conductor. The former dielectric loss tends to decrease as the dielectric tangent of the resin becomes smaller. The latter conductor loss is caused by the fact that as the frequency increases, the cross-sectional area through which current flows decreases due to the skin effect (the phenomenon in which signals flow through a thickness of 1 to 2 μm from the surface of the conductor), and resistance increases.

On the other hand, it is known that a high dielectric constant has the advantage that the antenna shape can be made smaller.
For example, Patent Document 1 discloses a resin composition containing an epoxy resin, a dielectric powder such as barium titanate, a nonionic surfactant, and a curing agent in order to obtain a high dielectric constant resin layer by suppressing the formation of agglomerates of the dielectric powder.

JP 2017-14406 A

However, in recent years, the technical level required for various properties of high dielectric resin compositions has become increasingly higher. The inventors focused on developing a new material that achieves a high dielectric constant and a low dielectric tangent. As a result of extensive investigation, it was found that the conventional technology described in the above Patent Document 1 has room for improvement in terms of responding to high frequencies and miniaturization.

After further investigation, the inventors discovered that in a high dielectric resin composition containing an epoxy resin (A) and an inorganic filler (B) with a dielectric constant (1 MHz) of 6 or more, by controlling the dielectric constant and dielectric dissipation factor as indicators, it is possible to achieve an excellent balance between a high dielectric constant and a low dielectric dissipation factor, and to improve adhesion to copper foil, thereby realizing a higher level of high frequency and miniaturization than ever before.

According to the present invention, there is provided a high dielectric resin composition comprising an epoxy resin (A) and an inorganic filler (B) having a dielectric constant (1 MHz) of 6 or more,
The present invention provides a high dielectric resin composition, the dielectric constant (Dk: εr) of a cured product of the high dielectric resin composition at 10 GHz being 4 to 10, and the dielectric loss tangent (Df: tan δ) of a cured product of the high dielectric resin composition at 10 GHz being 0.003 to 0.015.

The present invention also provides a cured product of the above-mentioned high dielectric resin composition.

The present invention also provides a prepreg containing a fiber base material in the high dielectric resin composition.

The present invention also provides a laminate having a metal layer disposed on at least one surface of the prepreg.

The present invention also provides a resin film with a carrier, comprising a carrier substrate and a resin film made of the high dielectric resin composition provided on the carrier substrate.

The present invention also provides a printed wiring board having an insulating layer made of a cured product of the high dielectric resin composition.

Further, according to the present invention,
The printed wiring board;
and a semiconductor element mounted on a circuit layer of the printed wiring board or embedded in the printed wiring board.

The present invention provides a high dielectric resin composition that can achieve high frequency and compact size, and a resin film with a carrier, a prepreg, a laminate, a printed wiring board, and a semiconductor device that use the same.

FIG. 1 is a diagram illustrating an example of a configuration of a substrate-attached resin sheet according to an embodiment of the present invention. 1A to 1C are cross-sectional views showing an example of a manufacturing process for the semiconductor device according to the embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In all drawings, the same components are given the same reference numerals and the description will be omitted as appropriate. In addition, the drawings are schematic diagrams and do not correspond to the actual dimensional ratio.
In addition, in this specification, the expression "a to b" in the description of a numerical range means from a to b, unless otherwise specified. For example, "1 to 5% by mass" means "1% by mass to 5% by mass."

In this embodiment, the "cured product" of the high dielectric resin composition is intended to be, for example, a resin plate obtained by stacking multiple resin sheets and using a vacuum press under conditions of a temperature of 225°C, a pressure of 0.5 MPa, and a curing time of 2 hours. For example, it is 100 mm square and 0.5 mm thick.

In addition, in this embodiment, the content of each component contained in the high dielectric resin composition is the content (mass %) relative to 100 mass % of the solid content of the high dielectric resin composition, unless otherwise specified.

<Highly dielectric resin composition>
The high dielectric resin composition of the present embodiment contains an epoxy resin (A) and an inorganic filler (B) having a dielectric constant (1 MHz) of at least 6. Furthermore, the dielectric constant (Dk: εr) at 10 GHz of a cured product of the high dielectric resin composition is 4 to 10, and the dielectric dissipation factor (Df: tan δ) at 10 GHz of a cured product of the high dielectric resin composition is 0.003 to 0.015.
This provides an excellent balance between high dielectric constant and low dielectric tangent, while also improving adhesion to copper foil, enabling the realization of higher frequencies and smaller size than ever before.

[Dielectric constant/dielectric tangent]
The dielectric constant (Dk: εr) at 10 GHz of the cured product of the high dielectric resin composition of this embodiment is 4 to 10, preferably 5 to 9, more preferably 6 to 8, and even more preferably 6 to 7.
By setting the dielectric constant to be equal to or greater than the lower limit, miniaturization becomes possible, whereas by setting the dielectric constant to be equal to or less than the upper limit, a good balance between high frequency and miniaturization can be maintained.

In addition, the dielectric loss tangent (Df: tan δ) at 10 GHz of the cured product of the high dielectric resin composition of this embodiment is 0.003 to 0.015, preferably 0.003 to 0.010, more preferably 0.003 to 0.009, and even more preferably 0.003 to 0.008.
By setting the dielectric loss tangent to the lower limit or more, it is possible to improve the adhesion reliability between the conductor line serving as the antenna and the dielectric layer, and to stably maintain antenna performance while maintaining a good balance between high frequency and miniaturization. On the other hand, by setting the dielectric loss tangent to the upper limit or less, it is possible to suppress energy loss and accommodate higher frequencies. That is, from the viewpoint of reducing transmission loss, the lower the dielectric loss tangent, the better, but the lower the dielectric, the lower the adhesion to the conductor serving as the antenna tends to be. Therefore, from the viewpoint of achieving both high frequency and miniaturization, it is preferable to set the dielectric loss tangent to the lower limit or more while retaining a certain degree of polarity.

The above-mentioned dielectric constant and dielectric loss tangent can be controlled by known methods, such as by appropriately selecting the type and amount of each component contained in the high dielectric resin composition, the preparation method of the high dielectric resin composition, etc. For example, the higher the content of the inorganic filler (B) with a large dielectric constant, the more the above-mentioned relative dielectric constant (εr) of the cured body of the high dielectric resin composition can be improved.

[Peel Strength]
The peel strength of the cured film made of the high dielectric resin composition of this embodiment against copper foil is preferably 0.5 kN/m or more, and more preferably 0.6 kN/m or more.
This provides high adhesion to the copper foil.

In this embodiment, the peel strength is measured, for example, as follows.
First, a resin layer made of the high dielectric resin composition is formed on a substrate, and a copper foil having a surface roughness Rz of 2 μm or less is placed on the resin layer, and vacuum pressed at a temperature of 225° C. to form a laminate of the cured film of the resin layer and the copper foil. The stress when peeling the cured film from the copper foil using the obtained laminate is taken as the peel strength. The peel strength can be measured in accordance with "JIS C 6481". If necessary, the copper foil may be copper plated to increase the thickness, for example to about 20 μm, before measurement.

The peel strength of the high dielectric resin composition of this embodiment can be controlled by the number of polar functional groups of the resin composition, etc.

[Complex dynamic viscosity]
The minimum value of the complex dynamic viscosity η1 of the high dielectric resin composition in a dynamic viscoelasticity test at a measurement range of 50 to 200° C., a heating rate of 3° C./min, and a frequency of 62.83 rad/sec is preferably 50 to 2000 Pa·s, more preferably 100 to 1500 Pa·s, thereby improving the dispersibility of the inorganic filler (B) described below, and enabling a stable balance between a high dielectric constant and a low dielectric loss tangent to be obtained.

The complex dynamic viscosity of the high dielectric resin composition of this embodiment can be controlled by adjusting the content of the inorganic filler or by changing the particle size of the inorganic filler.

[Glass transition temperature]
In this embodiment, the glass transition temperature of the cured product of the high dielectric resin composition is preferably 100° C. or higher, more preferably 120° C. or higher, and even more preferably 140° C. or higher. This makes it possible to more effectively improve the heat resistance of the cured product of the high dielectric resin composition. On the other hand, the upper limit of the glass transition temperature is not particularly limited, but can be, for example, 250° C.

The glass transition temperature of the cured product of the highly dielectric resin composition can be measured, for example, as follows.
The cured product of the highly dielectric resin composition is further post-cured at 175°C for 4 hours, and then measured using a thermomechanical analyzer (Seiko Denshi Kogyo Co., Ltd., TMA100) under conditions of a measurement temperature range of 0°C to 320°C and a heating rate of 5°C/min. The glass transition temperature is calculated from the measurement results.

The glass transition temperature of the high dielectric resin composition of this embodiment can be controlled by appropriately adjusting the types and mixing ratios of each component that constitutes the high dielectric resin composition.

The components contained in the resin composition of this embodiment are described in detail below.

As the epoxy resin (A), any monomer, oligomer or polymer having two or more epoxy groups in one molecule can be used, and the molecular weight and molecular structure thereof are not particularly limited.
In the present embodiment, examples of the epoxy resin (A) include biphenyl-type epoxy resins; bisphenol-type epoxy resins such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and tetramethylbisphenol F-type epoxy resins; stilbene-type epoxy resins; novolac-type epoxy resins such as phenol novolac-type epoxy resins and cresol novolac-type epoxy resins; multifunctional epoxy resins such as triphenolmethane-type epoxy resins and alkyl-modified triphenolmethane-type epoxy resins; aralkyl-type epoxy resins such as phenol aralkyl-type epoxy resins having a phenylene skeleton and phenol aralkyl-type epoxy resins having a biphenylene skeleton; naphthol-type epoxy resins such as dihydroxynaphthalene-type epoxy resins and epoxy resins obtained by glycidyl etherifying a dimer of dihydroxynaphthalene; triazine nucleus-containing epoxy resins such as triglycidyl isocyanurate and monoallyl diglycidyl isocyanurate; and bridged cyclic hydrocarbon compound-modified phenol-type epoxy resins such as dicyclopentadiene-modified phenol-type epoxy resins. These may be used alone or in combination of two or more.
Among these, from the viewpoint of improving the balance between moisture resistance reliability and moldability, the epoxy resin (A) preferably contains one or more types selected from the group consisting of bisphenol type epoxy resins, novolac type epoxy resins, biphenyl type epoxy resins, phenol aralkyl type epoxy resins, and triphenol methane type epoxy resins, and more preferably contains at least one type selected from the group consisting of biphenyl type epoxy resins and phenol aralkyl type epoxy resins.

It is more preferable to use, as the epoxy resin (A), one containing at least one selected from the group consisting of an epoxy resin represented by the following formula (1), an epoxy resin represented by the following formula (2), and an epoxy resin represented by the following formula (3).

（式（１）中、Ａｒ^１はフェニレン基またはナフチレン基を表し、Ａｒ^１がナフチレン基の場合、グリシジルエーテル基はα位、β位のいずれに結合していてもよい。Ａｒ^２はフェニレン基、ビフェニレン基またはナフチレン基のうちのいずれか１つの基を表す。Ｒ_ａおよびＲ_ｂは、それぞれ独立に炭素数１～１０の炭化水素基を表す。ｇは０～５の整数であり、ｈは０～８の整数である。ｎ^３は重合度を表し、その平均値は１～３である。）

(In formula (1), Ar ¹ represents a phenylene group or a naphthylene group, and when Ar ¹ is a naphthylene group, the glycidyl ether group may be bonded to either the α-position or the β-position. Ar ² represents any one of a phenylene group, a biphenylene group, and a naphthylene group. _{R a} and R _b each independently represent a hydrocarbon group having 1 to 10 carbon atoms. g represents an integer of 0 to 5, and h represents an integer of 0 to 8. ^{n 3} represents the degree of polymerization, the average value of which is 1 to 3.)

（式（２）中、複数存在するＲ_ｃは、それぞれ独立に水素原子または炭素数１～４の炭化水素基を表す。ｎ^５は重合度を表し、その平均値は０～４である。）

(In formula (2), each of the multiple _Rc's independently represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. ⁿ⁵ represents the degree of polymerization, and its average value is 0 to 4.)

（式（３）中、複数存在するＲ_ｄおよびＲ_ｅは、それぞれ独立に水素原子又は炭素数１～４の炭化水素基を表す。ｎ^６は重合度を表し、その平均値は０～４である。）

(In formula (3), each of the multiple _Rd and R _e independently represents a hydrogen atom or a hydrocarbon group having 1 to 4 carbon atoms. ⁿ⁶ represents the degree of polymerization, and its average value is 0 to 4.)

In this embodiment, the content of the epoxy resin (A) in the high dielectric resin composition is preferably 3% by mass or more, more preferably 7% by mass or more, and even more preferably 10% by mass or more, when the entire high dielectric resin composition is taken as 100% by mass. By making the content of the epoxy resin (A) equal to or more than the above lower limit, sufficient fluidity can be achieved during molding, and filling properties and moldability can be improved.
On the other hand, the content of the epoxy resin (A) in the high dielectric resin composition is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, when the entire high dielectric resin composition is taken as 100% by mass. By making the content of the epoxy resin (A) equal to or less than the above upper limit, it is possible to improve the moisture resistance reliability and reflow resistance of the cured product of the high dielectric resin composition.

[Inorganic filler (B)]
In this embodiment, the inorganic filler (B) has a dielectric constant (1 MHz) of 6 or more. This makes it possible to realize a resin composition having a high dielectric constant even if it has a low dielectric tangent.
The inorganic filler (B) is not particularly limited and may be any known filler as long as it has a dielectric constant (1 MHz) of 6 or more. The inorganic filler (B) may be one or more selected from the group consisting of titanium oxide, magnesium oxide, alumina, tantalum pentoxide, and niobium pentoxide. Among them, the inorganic filler (B) may include those having a perovskite structure. For example, it is preferable that the composition does not contain barium titanate, and from the viewpoint of achieving a lower dielectric tangent, it is more preferable that the composition contains titanium oxide.

The inorganic filler (B) may also be surface-treated with inorganic and organic substances. Surface treatment methods can be broadly classified into (1) modification by coating, (2) topochemical modification, (3) modification by mechanochemical reaction, (4) modification by encapsulation, and (5) combined use with radiation irradiation. In detail, (1) is fatty acid treatment, surfactant treatment, etc., (2) is a method of organifying surface functional groups with organic substances or coupling agents, (3) is a method of utilizing the activity of new solid surfaces by mechanical treatment such as grinding, etc., and (4) is a method of encapsulating inorganic substances by wrapping them in polymers, etc.
Among these, it is preferable to make the surface functional groups organic by using the organic substance or coupling agent described in (2) above.

The content of the inorganic filler (B) is preferably 30% by mass or more, more preferably 35% by mass or more, and even more preferably 40% by mass or more, based on the total amount of the high dielectric resin composition. By making the content of the inorganic filler (B) equal to or more than the above lower limit, the dielectric properties of the high dielectric resin composition can be further improved.
On the other hand, the content of the inorganic filler (B) is preferably 80 mass% or less, more preferably 70 mass% or less, and even more preferably 55 mass% or less, based on the total amount of the high dielectric resin composition. By making the content of the inorganic filler (B) equal to or less than the above upper limit, it is possible to more effectively improve the fluidity and filling property during molding of the high dielectric resin composition.

The average particle diameter D50 of the inorganic filler (B) is preferably 0.01 μm or more and 10 μm or less, more preferably 0.05 μm or more and 8 μm or less. By making the average particle diameter D50 equal to or more than the lower limit, the flowability of the high dielectric resin composition can be improved, and the moldability can be more effectively improved. In addition, by making the average particle diameter D50 equal to or less than the upper limit, the occurrence of gate clogging can be reliably suppressed.
The average particle size D90 of the inorganic filler (B) is preferably 0.05 μm or more and 20 μm or less, and more preferably 0.2 μm or more and 15 μm or less.

The particle size of inorganic filler (B) and inorganic filler (b) described below can be determined by measuring the particle size distribution of the particles on a volume basis using a commercially available laser particle size distribution analyzer (e.g., SALD-7000, manufactured by Shimadzu Corporation), and the cumulative 50% frequency of the median diameter is defined as D50, and the cumulative 90% frequency is defined as D90.

The high dielectric resin composition of this embodiment may further contain the following components:

[Cyanate resin (C)]
The cyanate resin (C) makes it easier to impart a low thermal expansion coefficient and heat resistance to the resin composition.
The cyanate resin (C) is preferably an aromatic cyanate resin. Specific examples of the cyanate resin include novolac-type cyanate resins such as phenol novolac-type and cresol novolac-type cyanate resins; aralkyl-type cyanate resins such as phenyl aralkyl-type, biphenyl aralkyl-type and naphthalene aralkyl-type cyanate resins; and bisphenol-type cyanate resins such as bisphenol A-type cyanate resins, bisphenol E-type cyanate resins and tetramethyl bisphenol F-type cyanate resins.
Among these, bisphenol-type cyanate and/or novolac-type cyanate resins are preferred, and it is more preferred to use both in combination. The reason for this is that bisphenol-type cyanate ester resins have fewer crosslinking points, so that when triazine rings are formed, unreacted cyanate groups are less likely to remain, and it is thought that it is easier to maintain good dielectric properties. In addition, novolac-type cyanate resins form triazine rings after the curing reaction, so that it is possible to improve rigidity and heat resistance, and it is easier to respond to miniaturization and high frequency.

As the novolac-type cyanate resin, for example, one represented by the following general formula (I) can be used.

The average repeating unit n of the novolac cyanate resin (C) represented by the general formula (I) is any integer. The average repeating unit n is not particularly limited, but is preferably 1 or more, and more preferably 2 or more. When the average repeating unit n is equal to or more than the above lower limit, the heat resistance of the novolac cyanate resin (C) is improved, and the elimination and volatilization of low molecular weight molecules during heating can be suppressed. The average repeating unit n is not particularly limited, but is preferably 10 or less, and more preferably 7 or less. When n is equal to or less than the above upper limit, the melt viscosity can be suppressed from increasing, and the moldability of the prepreg can be improved.

The cyanate resin (C) may be modified, and may include, for example, a butadiene-modified cyanate modified with butadiene. The butadiene-modified cyanate may be obtained by mixing a cyanate ester compound with polybutadiene and then subjecting it to thermal polymerization, and/or by mixing a polymer of a cyanate ester compound with polybutadiene and then subjecting it to thermal polymerization. This allows the dielectric properties and miniaturization to be achieved while maintaining good heat resistance.

The weight average molecular weight (Mw) of the cyanate resin (C) is not particularly limited, but is preferably Mw 500 or more, and more preferably Mw 600 or more. If Mw is equal to or greater than the lower limit, the occurrence of tackiness can be suppressed when the prepreg is produced, and the prepregs can be prevented from adhering to each other when they come into contact with each other, or from transferring. Furthermore, Mw is not particularly limited, but is preferably Mw 4,500 or less, and more preferably Mw 3,000 or less. If Mw is equal to or less than the upper limit, the cyclization reaction of the cyanate resin (C) can be prevented from becoming too fast, and defects in the insulating layer and a decrease in the peel strength between the insulating layer and the metal layer can be prevented.

The Mw of the cyanate resin (C) can be measured, for example, by GPC (gel permeation chromatography, standard substance: polystyrene equivalent).

The cyanate resin (C) may be used alone or in combination of two or more types having different Mw, or in combination of one or more types and their prepolymers.

In this embodiment, the content of the cyanate resin (C) in the high dielectric resin composition is preferably 7% by mass or more, more preferably 10% by mass or more, and even more preferably 12% by mass or more, when the entire high dielectric resin composition is 100% by mass.
On the other hand, the content of the cyanate resin (C) in the high dielectric resin composition is preferably 30 mass% or less, more preferably 27 mass% or less, and even more preferably 25 mass% or less, when the entire high dielectric resin composition is 100 mass%.

[Cumarone resin (D)]
The coumarone resin (D) in this embodiment refers to a (co)polymer containing a coumarone residue in its skeleton structure and having an average degree of polymerization of 4 to 8, and may be a coumarone (1-benzofuran) polymer, as well as a copolymer with indene (C ₉ H ₈ ), styrene (C ₈ H ₈ ), α-methylstyrene, methylindene, or vinyltoluene. Of these, a coumarone-indene copolymer or a coumarone-indene-styrene copolymer is preferred.

The indene-cumarone resin contains structural unit A derived from an indene-based monomer and structural unit B derived from a cumarone-based monomer. The indene-cumarone resin may also have structural units derived from other monomers. The indene-cumarone resin may, for example, have structural unit C derived from a styrene-based monomer. It can have a repeating structure of these structural units.

The structural unit A derived from the indene monomer is, for example, one represented by the following general formula (M1):

(In general formula (M1), R ¹ to R ⁷ are each independently a hydrogen atom or an organic group having 1 to 3 carbon atoms.)

The structural unit B derived from the coumarone monomer is, for example, one represented by the following general formula (M2):

(In general formula (M2), R ^C represents a hydrogen atom or an organic group having 1 to 3 carbon atoms. R ^C may be the same as or different from each other.)

Examples of the structural unit C derived from the styrene-based monomer include those represented by the following general formula (M3).

(In general formula (M3), R 1 ^S is a hydrogen atom or an organic group having 1 to 3 carbon atoms. R ^{1 S} may be the same as or different from each other.)

In the above general formulas (M1) to (M3), R1 to R7, R C and R S may, for example, contain atoms other than hydrogen and carbon in the structure of the organic group.
Specific examples of the atoms other than hydrogen and carbon include oxygen atoms, nitrogen atoms, sulfur atoms, phosphorus atoms, silicon atoms, fluorine atoms, chlorine atoms, etc. The atoms other than hydrogen and carbon may include one or more of the above specific examples.

In the above general formulas (M1) to (M3), R1 to R7, RC, and RS are each independently, for example, hydrogen or an organic group having 1 to 3 carbon atoms, preferably hydrogen or an organic group having 1 carbon atom, and more preferably hydrogen.

In the above general formulas (M1) to (M3), examples of the organic groups constituting R1 to R7, RC, and RS include alkyl groups such as methyl, ethyl, and n-propyl groups; alkenyl groups such as allyl and vinyl groups; alkynyl groups such as ethynyl groups; alkylidene groups such as methylidene and ethylidene groups; cycloalkyl groups such as cyclopropyl groups; and heterocyclic groups such as epoxy and oxetanyl groups.

The indene-cumarone resin may contain a copolymer of indene, cumarone and styrene. This can improve the low dielectric properties.

Furthermore, the indene-cumarone resin can have a reactive group in the molecule that reacts with the epoxy group of the epoxy resin, thereby improving the low dielectric properties.
Examples of the reactive group include an OH group and a COOH group.
The indene-cumarone resin may have an aromatic structure having a phenolic hydroxyl group inside or at the end.

The upper limit of the weight average molecular weight Mw of the indene-cumarone resin is, for example, preferably 4000 or less, more preferably 2000 or less, even more preferably 1500 or less, and even more preferably 1200 or less. This improves the compatibility between the indene-cumarone resin and the epoxy resin, and allows the indene-cumarone resin to be properly dispersed. On the other hand, the lower limit of the weight average molecular weight Mw of the indene-cumarone resin is, for example, preferably 400 or more, more preferably 500 or more, even more preferably 550 or more, and even more preferably 600 or more. This allows the indene-cumarone resin to be properly dispersed in the resin composition.

The lower limit of the content of the indene-cumarone resin is, for example, 1% by mass or more, preferably 3% by mass or more, and more preferably 5% by mass or more, when the entire high dielectric resin composition of this embodiment is taken as 100% by mass. This makes it possible to improve low dielectric properties and low water absorption properties. On the other hand, the upper limit of the content of the indene-cumarone resin is, for example, 15% by mass or less, preferably 12% by mass or less, and more preferably 10% by mass or less, when the entire high dielectric resin composition of this embodiment is taken as 100% by mass. This makes it possible to achieve a balance with other physical properties.

The melting point of the chroman resin (D) is preferably 40°C to 120°C, and the melting point can be controlled by the molecular weight and degree of polymerization.

The content of the coumarone resin (D) is preferably 1% by mass or more and 25% by mass or less, more preferably 5% by mass or more and 20% by mass or less, and even more preferably 8% by mass or more and 15% by mass or less, when the entire high dielectric resin composition is taken as 100% by mass.

[Inorganic filler (b)]
The high dielectric resin composition of the present embodiment may contain an inorganic filler other than the above-mentioned inorganic filler (B), that is, an inorganic filler (b) having a dielectric constant (1 MHz) of less than 6.
Examples of the inorganic filler (b) having a dielectric constant (1 MHz) of less than 6 include silicates such as talc, calcined clay, uncalcined clay, mica, and glass; titanium oxide, alumina, boehmite, silica, and fused silica. oxides; carbonates such as calcium carbonate, magnesium carbonate, and hydrotalcite; hydroxides such as aluminum hydroxide, magnesium hydroxide, and calcium hydroxide; sulfates or sulfites such as barium sulfate, calcium sulfate, and calcium sulfite. borates such as zinc borate, barium metaborate, aluminum borate, calcium borate, sodium borate, and the like; nitrides such as aluminum nitride, boron nitride, silicon nitride, carbon nitride, and the like.
The inorganic filler (b) may be surface-treated with an inorganic or organic substance in the same manner as the inorganic filler (B).
Among these, talc, alumina, glass, silica, mica, aluminum hydroxide, and magnesium hydroxide are preferable, and silica is more preferable.
The dielectric constant of the inorganic filler (b) is not particularly limited, but may be, for example, 1-5 or 2-4.

The average particle diameter D50 of the inorganic filler (b) is not particularly limited, but is preferably 0.01 to 10 μm, more preferably 0.05 to 5 μm, and even more preferably 0.2 to 3 μm. By making the average particle diameter D50 of the inorganic filler (b) equal to or greater than the lower limit, it is possible to suppress an increase in viscosity and maintain good workability. On the other hand, by making the average particle diameter D50 of the inorganic filler (b) equal to or less than the upper limit, it is possible to improve the dispersibility of the inorganic filler (b).

[Curing agent]
The high dielectric resin composition may contain, for example, a curing agent. The curing agent is not particularly limited as long as it reacts with the epoxy resin (A) to cure it, and examples of the curing agent include linear aliphatic diamines having 2 to 20 carbon atoms, such as ethylenediamine, trimethylenediamine, tetramethylenediamine, and hexamethylenediamine, metaphenylenediamine, paraphenylenediamine, paraxylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylether, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodicyclohexane, bis(4-aminophenyl)phenylmethane, 1,5-diaminonaphthalene, metaxylenediamine, paraxylenediamine, 1,1-bis(4-aminophenyl)cyclohexane, and dicyanodiamide; resol-type phenolic resins, such as aniline-modified resol resins and dimethyl ether resol resins; phenol novolac resins, cresol novolac resins, and tert-butylphenol. Examples of the organic acids include novolac-type phenolic resins such as novolac resins and nonylphenol novolac resins; polyfunctional phenolic resins such as trisphenolmethane-type phenolic resins; phenol aralkyl resins such as phenylene skeleton-containing phenol aralkyl resins and biphenylene skeleton-containing phenol aralkyl resins; phenolic resins having a condensed polycyclic structure such as a naphthalene skeleton or an anthracene skeleton; polyoxystyrenes such as polyparaoxystyrene; alicyclic acid anhydrides such as hexahydrophthalic anhydride (HHPA) and methyltetrahydrophthalic anhydride (MTHPA), and aromatic acid anhydrides such as trimellitic anhydride (TMA), pyromellitic anhydride (PMDA), and benzophenonetetracarboxylic acid (BTDA); polymercaptan compounds such as polysulfides, thioesters, and thioethers; isocyanate compounds such as isocyanate prepolymers and blocked isocyanates; and organic acids such as carboxylic acid-containing polyester resins. These may be used alone or in combination of two or more.

The content of the curing agent in the high dielectric resin composition is not particularly limited, but for example, when the entire high dielectric resin composition is taken as 100 mass%, it is preferably 0.1 mass% or more and 20 mass% or less, more preferably 0.5 mass% or more and 10 mass% or less, and even more preferably 1 mass% or more and 5 mass% or less.

[Coupling Agent]
The high dielectric resin composition may contain, for example, a coupling agent, such as various known coupling agents including silane-based compounds such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, and vinylsilane, titanium-based compounds, aluminum chelates, and aluminum/zirconium-based compounds.
Examples of these include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-anilinopropyltrimethoxysilane, lan, γ-anilinopropylmethyldimethoxysilane, γ-[bis(β-hydroxyethyl)]aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β-(aminoethyl)-γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-(β-aminoethyl)aminopropyldimethoxymethylsilane, N-(trimethoxysilylpropyl)ethylenediamine, N-(dimethoxymethylsilylisopropyl)ethylenediamine, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, N- Silane coupling agents such as β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, vinyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, and hydrolysates of 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine; isopropyl triisostearoyl titanate, isopropyl tris(dioctylpyrophosphate) titanate, isopropyl tri(N-aminoethyl-aminoethyl) titanate, tetraoctylbis(ditridecylphosphinate), Examples of the titanate coupling agents include tetra(2,2-diallyloxymethyl-1-butyl)bis(ditridecyl)phosphite titanate, bis(dioctyl pyrophosphate)oxyacetate titanate, bis(dioctyl pyrophosphate)ethylene titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri(dioctyl phosphate) titanate, isopropyl tricumylphenyl titanate, and tetraisopropyl bis(dioctyl phosphite) titanate. These may be used alone or in combination of two or more.

The content of the coupling agent in the high dielectric resin composition is not particularly limited, but is preferably 0.01% by mass or more and 3% by mass or less, and more preferably 0.1% by mass or more and 2% by mass or less, when the entire high dielectric resin composition is taken as 100% by mass. By making the content of the coupling agent equal to or more than the above lower limit, the dispersibility of the inorganic filler (B) in the high dielectric resin composition can be improved. In addition, by making the content of the coupling agent equal to or less than the above upper limit, the flowability of the high dielectric resin composition can be improved, and moldability can be improved.

[Other ingredients]
In addition to the above components, the high dielectric resin composition may contain various additives such as a phosphorus atom-containing compound such as an organic phosphine, a tetra-substituted phosphonium compound, a phosphobetaine compound, an adduct of a phosphine compound and a quinone compound, or an adduct of a phosphonium compound and a silane compound, or an amidine compound such as 1,8-diazabicyclo(5.4.0)undecene-7, imidazole, or the like, a tertiary amine such as benzyldimethylamine, an amidinium salt which is a quaternary onium salt of the above compound, or an ammonium salt, or the like, a hardening accelerator such as a compound in which a hydroxyl group is bonded to each of two or more adjacent carbon atoms constituting an aromatic ring; a colorant such as carbon black; a release agent such as natural wax, synthetic wax, higher fatty acid or a metal salt thereof, paraffin, or polyethylene oxide; a low stress agent such as a polybutadiene compound, an acrylonitrile butadiene copolymer compound, a silicone oil, or a silicone rubber; an ion trapping agent such as hydrotalcite; a flame retardant such as aluminum hydroxide; and an antioxidant.

<Varnish>
The highly dielectric resin composition of the present embodiment can be dissolved in a solvent to form a varnish.
Examples of the solvent include organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, toluene, ethyl acetate, cyclohexane, heptane, cyclohexane, cyclohexanone, tetrahydrofuran, dimethylformamide, dimethylacetamide, dimethylsulfoxide, ethylene glycol, cellosolve-based solvents, carbitol-based solvents, anisole, and N-methylpyrrolidone. These may be used alone or in combination of two or more kinds.

When the high dielectric resin composition of this embodiment is in the form of a varnish, the solid content of the resin composition may be, for example, 30% by mass or more and 80% by mass or less, and more preferably 40% by mass or more and 70% by mass or less. This allows for excellent workability and film-forming properties.

The varnish-like resin composition can be prepared by dissolving, mixing, and stirring the above-mentioned components in a solvent using various mixers, such as those used in ultrasonic dispersion, high-pressure collision dispersion, high-speed rotation dispersion, bead mill, high-speed shear dispersion, and rotation-revolution dispersion.

<Resin film>
Next, the resin film of this embodiment will be described.
The resin film of this embodiment can be obtained by forming the above-mentioned resin composition in a varnish state into a film. For example, the resin film of this embodiment can be obtained by removing the solvent from a coating film obtained by applying the resin composition in a varnish state. In such a resin film, the solvent content can be 5 mass% or less with respect to the entire resin film. In this embodiment, for example, a step of removing the solvent may be performed under conditions of 100°C to 150°C and 1 minute to 5 minutes. This makes it possible to sufficiently remove the solvent while suppressing the progress of curing of the resin film containing a thermosetting resin.

The resin film of this embodiment may be composed of a resin film alone, or may be composed to include a fiber substrate inside.

<Prepreg>
The prepreg of the present embodiment is configured to contain a fibrous base material in the high dielectric resin composition of the present embodiment. The prepreg is obtained by impregnating a fibrous base material with the resin composition.
For example, prepreg can be used as a sheet-like material obtained by impregnating a fiber substrate with a resin composition and then semi-curing the same. A sheet-like material having such a structure has excellent properties such as dielectric properties and mechanical and electrical connection reliability under high temperature and humidity, and is suitable for producing an insulating layer for a printed wiring board.

In this embodiment, the method of impregnating the fiber substrate with the resin composition is not particularly limited, but examples include a method of dissolving the resin composition in a solvent to prepare a resin varnish and immersing the fiber substrate in the resin varnish, a method of applying the resin varnish to the fiber substrate using various coaters, a method of spraying the resin varnish onto the fiber substrate using a sprayer, and a method of laminating both sides of the fiber substrate with the resin film made of the resin composition.

Examples of the fiber substrate include glass fiber substrates such as woven glass cloth and nonwoven glass cloth, inorganic fiber substrates such as woven or nonwoven cloth containing inorganic compounds other than glass, and organic fiber substrates made of organic fibers such as aromatic polyamideimide resin, polyamide resin, aromatic polyester resin, polyester resin, polyimide resin, and fluororesin. Among these substrates, the use of glass fiber substrates such as woven glass cloth, which is representative of the strength of these substrates, can improve the mechanical strength and heat resistance of the printed wiring board.

The thickness of the fiber base material is not particularly limited, but is preferably 5 μm to 150 μm, more preferably 10 μm to 100 μm, and even more preferably 12 μm to 90 μm. By using a fiber base material having such a thickness, the handleability during prepreg production can be further improved.
When the thickness of the fiber substrate is equal to or less than the upper limit, the impregnation of the resin composition in the fiber substrate is improved, and the occurrence of strand voids and deterioration of insulation reliability can be suppressed. In addition, the formation of through holes by carbon dioxide, UV, excimer, or other lasers can be facilitated. In addition, when the thickness of the fiber substrate is equal to or more than the lower limit, the strength of the fiber substrate and prepreg can be improved. As a result, the handling property can be improved, the preparation of prepreg can be facilitated, and the warping of the resin substrate can be suppressed.

As the glass fiber substrate, for example, a glass fiber substrate formed from one or more types of glass selected from E glass, S glass, D glass, T glass, NE glass, UT glass, L glass, HP glass, and quartz glass is preferably used.

In this embodiment, the prepreg can be used, for example, to form an insulating layer in a build-up layer or an insulating layer in a core layer in a printed wiring board. When the prepreg is used to form an insulating layer in a core layer in a printed wiring board, for example, two or more prepregs can be stacked and the resulting laminate can be heat-cured to form an insulating layer for the core layer.

<Metal-clad laminate>
The laminate of the present embodiment is a metal-clad laminate in which a metal layer is disposed on at least one surface of the cured product of the prepreg.

A method for producing a metal-clad laminate using a prepreg is, for example, as follows.
A metal foil is placed on both the upper and lower sides or one side of the outer side of a prepreg or a laminate of two or more prepregs, and these are bonded under high vacuum conditions using a laminator or Becquerel device, or a metal foil is placed on both the upper and lower sides or one side of the outer side of the prepreg as is. When two or more prepregs are laminated, a metal foil is placed on both the upper and lower sides or one side of the outermost side of the laminated prepregs. Next, a metal-clad laminate can be obtained by hot-pressing and molding the laminate of the prepreg and the metal foil. Here, it is preferable to continue pressing until the end of cooling during hot-pressing and molding.

Examples of metals constituting the metal foil include copper, copper-based alloys, aluminum, aluminum-based alloys, silver, silver-based alloys, gold, gold-based alloys, zinc, zinc-based alloys, nickel, nickel-based alloys, tin, tin-based alloys, iron, iron-based alloys, Fe-Ni-based alloys such as Kovar (trade name), 42 alloy, Invar, and Super Invar, W, and Mo. Among these, the metal constituting the metal foil 105 is preferably copper or a copper alloy because it has excellent conductivity, is easy to form a circuit by etching, and is inexpensive. That is, copper foil is preferable as the metal foil 105.
As the metal foil, a metal foil with a carrier or the like can also be used.
The thickness of the metal foil is preferably 0.5 μm or more and 20 μm or less, and more preferably 1.5 μm or more and 18 μm or less.

<Resin film with carrier>
Next, the resin film with a carrier of this embodiment will be described.
FIG. 1 is a diagram showing an example of the configuration of a resin film 10 with a carrier.

An example of the above-mentioned carrier-attached resin film 10 includes a carrier substrate 30 and a resin film 20 made of a resin composition provided on the carrier substrate 30.

The resin film 10 with a carrier may be in the form of a roll that can be wound up as shown in FIG. 1(a), or in the form of rectangular sheets.

As the carrier substrate 30, for example, a polymer film or a metal foil can be used. The polymer film is not particularly limited, but examples thereof include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polycarbonate, release paper such as silicone sheets, and heat-resistant thermoplastic resin sheets such as fluorine-based resins and polyimide resins. The metal foil is not particularly limited, but examples thereof include copper and/or copper-based alloys, aluminum and/or aluminum-based alloys, iron and/or iron-based alloys, silver and/or silver-based alloys, gold and gold-based alloys, zinc and zinc-based alloys, nickel and nickel-based alloys, and tin and tin-based alloys. Among these, a sheet made of polyethylene terephthalate is most preferable because it is inexpensive and the peel strength can be easily adjusted. This makes it easy to peel off the resin film 10 with the carrier with an appropriate strength.

The surface of the carrier-attached resin film 10 may be exposed or may be covered with a protective film (cover film 50), for example. As the protective film, a film having a known protective function may be used, for example, a PET film. As shown in FIG. 1(b), the resin film 20 may be formed between the carrier substrate 30 and the cover film 50. This improves the handleability of the resin film 20.

The resin film 20 of the carrier-attached resin film 10 of this embodiment may be a single layer or a multilayer, and may be composed of one or more types of films. When the resin sheet is multilayered, it may be composed of the same type or different types.

The lower limit of the thickness of the resin film 20 is, for example, 5 μm or more, and preferably 10 μm or more. This can improve the insulation reliability. On the other hand, the upper limit of the thickness of the resin film 20 is, for example, 50 μm or less, and preferably 40 μm or less. This can realize a thinner printed wiring board. In addition, by setting the thickness of the resin film 20 within the above range, when manufacturing the printed wiring board, it is possible to fill and mold the unevenness of the inner layer circuit, and it is possible to ensure a suitable thickness of the insulating resin layer of the build-up layer.

The thickness of the carrier substrate 30 is not particularly limited, but may be, for example, 10 to 100 μm, or 10 to 70 μm. This is preferable because it improves the handleability when manufacturing the carrier-attached resin film 10.

<Printed wiring board>
The printed wiring board of this embodiment includes an insulating layer made of the above-mentioned cured resin film (cured resin composition).
In this embodiment, the cured resin film can be used, for example, as a build-up layer of a normal printed wiring board, a build-up layer in a printed wiring board having no core layer, a build-up layer of a coreless substrate used in PLP, a build-up layer of an MIS substrate, etc. The insulating layer constituting such a build-up layer can also be suitably used as a build-up layer constituting a large-area printed wiring board used to collectively produce a plurality of semiconductor packages.

In addition, in this embodiment, the resin film made of the resin composition for forming the insulating film can be impregnated with glass fibers. Even in a semiconductor package using such a resin film in the build-up layer, the linear expansion coefficient of the cured resin film can be reduced, so package warpage can be sufficiently suppressed.

<Semiconductor package>
2A to 2C are cross-sectional views showing an example of a manufacturing process for the semiconductor package 200 of this embodiment.
The semiconductor device (semiconductor package 200) of this embodiment can include a printed wiring board and a semiconductor element 240 mounted on a circuit layer of the printed wiring board or embedded in the printed wiring board.

An outline of the manufacturing process for the semiconductor package 200 of this embodiment will be described below.
First, as shown in FIG. 2(a), a core layer 100 including an insulating layer 102, a via hole 104, and a metal layer 108 is prepared. A via hole 104 is formed in the insulating layer 102. A metal layer (via) is embedded in the via hole 104. The metal layer may be covered with an electroless metal plating film 106. The metal layer 108 (a circuit layer having a predetermined circuit pattern) formed on the surface of the insulating layer 102 is electrically connected to the via formed in the via hole 104. In FIG. 2(a), the metal layer 108 is formed on one surface of the core layer 100, but it may be formed on both surfaces.

Next, a resin film 20 made of the above resin composition is formed on one surface of the core layer 100 so as to embed the metal layer 108. For example, the cover film 50 may be peeled off from the carrier-attached resin film 10, and the resin film 20 (insulating film) may be placed on the circuit-forming surface of the core layer 100. A carrier base material 30 is provided on the surface of this resin film 20. The carrier base material 30 may be separated from the resin film 20 at this point, or may be used as a mask.
The resin film 20 may be a single insulating layer, or may be made up of multiple layers including an insulating layer and a primer layer.

Next, an opening (not shown) is formed in the resin film 20 via the carrier substrate 30. The opening can be formed so as to expose the metal layer 108. The method for forming the opening is not particularly limited, and can be, for example, a laser processing method, an exposure and development method, or a blasting method.

In this embodiment, after forming such openings, the resin film 20 may be thermally cured. Then, the carrier substrate 30 is peeled off.

If necessary, a desmear process can be performed. The desmear process removes smears that have formed inside the openings and roughens the surface of the resin film 20.

The method of the desmearing process is not particularly limited, but can be performed, for example, as follows. First, the core layer 100 on which the resin film 20 is laminated is immersed in a swelling liquid containing an organic solvent, and then immersed in an alkaline permanganate aqueous solution to neutralize and roughen the layer. Diethylene glycol monobutyl ether, ethylene glycol, etc. can be used as the organic solvent. For example, "Swelling Dip Securigant P" manufactured by Atotech Japan can be used as such a swelling liquid. For example, potassium permanganate, sodium permanganate, etc. can be used as the permanganate. The liquid temperature of the swelling liquid or the permanganate aqueous solution may be, for example, 50°C or higher and 100°C or lower. The immersion time in the swelling liquid or the permanganate aqueous solution may be, for example, 1 minute or more and 30 minutes or less.

In the desmear process, only the wet desmear process described above can be performed, but plasma irradiation may also be performed in addition to the desmear process.

Next, an electroless metal plating film 202 is formed on the resin film 20 or on a primer layer (not shown) formed on the resin film 20. An example of an electroless plating method will be described. For example, catalytic nuclei are applied to the surface of the base layer. The catalytic nuclei are not particularly limited, but for example, precious metal ions or palladium colloids can be used. Then, using the catalytic nuclei as nuclei, an electroless plating process is performed to form an electroless metal plating film 202. For electroless plating, for example, a solution containing copper sulfate, formalin, a complexing agent, sodium hydroxide, etc. can be used. After electroless plating, a heat treatment at 100 to 250°C can be performed to stabilize the plating film.

Next, as shown in FIG. 2B, a resist 204 having a predetermined opening pattern (openings 206) may be formed on the electroless metal plating film 202. This opening pattern corresponds to, for example, a circuit pattern. The resist 204 is not particularly limited and may be any known material, but may be liquid or dry film. In the case of forming fine wiring, the resist 204 may be a photosensitive dry film or the like. An example using a photosensitive dry film will be described. For example, a photosensitive dry film is laminated on the electroless metal plating film 202, the non-circuit formation area is exposed to light to harden, and the unexposed area is dissolved and removed with a developer. The hardened photosensitive dry film is left behind to form the resist 204.

Next, as shown in FIG. 2(c), an electrolytic metal plating layer 208 is formed by electroplating at least inside the opening pattern of the resist 204 and on the electroless metal plating film 202. Although there is no particular limitation on the electroplating, a known method used in ordinary printed wiring boards can be used, for example, a method of passing an electric current through a plating solution such as copper sulfate while immersed in the plating solution can be used. The electrolytic metal plating layer 208 may be a single layer or may have a multi-layer structure. Although there is no particular limitation on the material of the electrolytic metal plating layer 208, for example, one or more of copper, copper alloy, 42 alloy, nickel, iron, chromium, tungsten, gold, and solder can be used.

Next, as shown in FIG. 2(d), the resist 204 is removed using an alkaline stripping solution, sulfuric acid, or a commercially available resist stripping solution.

Next, as shown in FIG. 2(e), the electroless metal plating film 202 is removed from the area (opening 210) other than the area where the electrolytic metal plating layer 208 is formed. That is, the electroless metal plating film 202 of the lower layer is selectively removed using the electrolytic metal plating layer 208 as a mask. For example, the electroless metal plating film 202 can be removed by using soft etching (flash etching) or the like. Here, the soft etching process can be performed by etching using an etching solution containing, for example, sulfuric acid and hydrogen peroxide. This allows the metal layer 220 having a predetermined pattern to be formed. In this way, the metal layer 220 composed of the electroless metal plating film 202 and the electrolytic metal plating layer 208 can be formed on the insulating layer made of the cured product of the resin film of this embodiment by the semi-additive process (SAP).

Furthermore, a multi-layer structure can be formed by stacking build-up layers as necessary on a printed wiring board composed of the core layer 100 and the above-mentioned build-up layers, and repeating the process of forming interlayer connections and circuits by a semi-additive process.
In this manner, the printed wiring board of the present embodiment is obtained.

Next, as shown in FIG. 2(f), build-up layers are laminated on the resulting printed wiring board as necessary, and the process of forming interlayer connections and circuits by a semi-additive process is repeated. Then, as necessary, a solder resist layer 230 is laminated on both sides or one side of the printed wiring board.

The method for forming the solder resist layer 230 is not particularly limited, but may be, for example, a method in which a dry film type solder resist is laminated, exposed to light, and developed, or a method in which a liquid resist is printed and then exposed to light and developed.

Next, a reflow process is performed to fix the semiconductor element 240 onto the connection terminals, which are part of the wiring pattern, via the solder bumps 250. Thereafter, the semiconductor element 240, the solder bumps 250, etc. are covered with a sealing material layer 260 for sealing.
As a result of the above, a semiconductor package 200 shown in FIG.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of the present invention are included in the present invention.
For example, the resin composition of the present embodiment can also be used as an encapsulant for encapsulating a semiconductor chip.
Below, examples of reference forms are given.
1. A high dielectric resin composition comprising an epoxy resin (A) and an inorganic filler (B) having a dielectric constant (1 MHz) of 6 or more,
A cured product of the high dielectric resin composition has a dielectric constant (Dk: εr) of 4 to 10 at 10 GHz, and a dielectric loss tangent (Df: tan δ) of 0.003 to 0.015 at 10 GHz.
2. The high dielectric resin composition according to 1., which contains a cyanate resin (C).
3. The highly dielectric resin composition according to 1. or 2., wherein the inorganic filler (B) does not include one having a perovskite structure.
4. The highly dielectric resin composition according to any one of 1. to 3., wherein a cured film made of the highly dielectric resin composition has a peel strength against copper foil of 0.5 kN/m or more.
5. The highly dielectric resin composition according to any one of 1. to 4., wherein the minimum value of complex dynamic viscosity η1 of the highly dielectric resin composition in a dynamic viscoelasticity test at a measurement range of 50 to 200° C., a heating rate of 3° C./min, and a frequency of 62.83 rad/sec is 50 to 2000 Pa s.
6. The highly dielectric resin composition according to any one of 1. to 5., wherein the inorganic filler (B) contains one or more selected from the group consisting of titanium oxide, magnesium oxide, alumina, tantalum pentoxide, and niobium pentoxide.
7. The highly dielectric resin composition according to any one of 1. to 6., wherein the inorganic filler (B) is surface-treated with an inorganic substance and an organic substance.
8. The highly dielectric resin composition according to any one of 1. to 7., wherein the epoxy resin (A) comprises one or more selected from the group consisting of bisphenol type epoxy resins, novolac type epoxy resins, biphenyl type epoxy resins, phenol aralkyl type epoxy resins, and triphenol methane type epoxy resins.
9. The high dielectric resin composition according to 2., wherein the cyanate resin (C) contains a butadiene-modified cyanate.
10. The highly dielectric resin composition according to any one of 1. to 9., further comprising a coumarone resin (D).
11. The highly dielectric resin composition according to any one of 1. to 10., wherein the content of the inorganic filler (B) is 30% by mass or less and 80% by mass or less with respect to the total amount of the highly dielectric resin composition.
12. A cured product of the high dielectric resin composition according to any one of 1. to 11.
13. A prepreg comprising a fiber base material in the high dielectric resin composition according to any one of 1. to 11.
14. A laminate comprising the prepreg according to 13. and a metal layer disposed on at least one surface of the prepreg.
15. A carrier substrate;
A resin film formed on the carrier substrate and made of the high dielectric resin composition according to any one of 1. to 11.;
A resin film with a carrier.
16. A printed wiring board comprising an insulating layer made of a cured product of the high dielectric resin composition according to any one of 1. to 11.
17. The printed wiring board according to 16.,
a semiconductor element mounted on a circuit layer of the printed wiring board or embedded in the printed wiring board.

The present invention will be described in detail below with reference to examples, but the present invention is not limited to the description of these examples.

<Examples and Comparative Examples>
(Preparation of High Dielectric Resin Composition)
Each component was dissolved or dispersed at the solid content ratio shown in Table 1, and the non-volatile content was adjusted to 70 mass % with methyl ethyl ketone. The mixture was stirred using a high-speed stirrer to prepare a varnish-like high dielectric resin composition (resin varnish P).
The numerical values showing the blending ratio of each component in Table 1 indicate the blending ratio (mass %) of each component relative to the total solid content of the high dielectric resin composition.
The results are shown in Table 1.

Details of the raw materials for each component in Table 1 are as follows.
(1) Epoxy resin (A)
Epoxy resin 1: Biphenyl type epoxy resin (manufactured by Mitsubishi Chemical Corporation, YX-4000K)
Epoxy resin 2: Phenol aralkyl type epoxy resin having a biphenylene skeleton (manufactured by Nippon Kayaku Co., Ltd., NC-3000)
Epoxy resin 3: Phenol aralkyl type epoxy resin having a biphenylene skeleton (manufactured by Nippon Kayaku Co., Ltd., NC-3500)
(2) Inorganic filler (B) having a dielectric constant (1 MHz) of 6 or more
Highly dielectric inorganic filler 1: titanium oxide (manufactured by Ishihara Sangyo Kaisha, Ltd., Typeque PF-728, D50: 0.21 μm, particle size D90: 1.0 μm, relative dielectric constant (1 MHz): 90, specific surface area: 20 m ² /g, shape: spherical, content of particles with a particle size of 0.5 μm or less: 80% by mass)
Highly dielectric inorganic filler 2: Alumina (manufactured by Micron Corporation, AX3-20R, D50: 3 μm, particle size D90: 10 μm, specific surface area: 0.6 m ² /g, relative dielectric constant (1 MHz): 8.9, shape: spherical, content of particles with a particle size of 0.5 μm or less: 14% by mass)
Highly dielectric inorganic filler 3: barium titanate (manufactured by Nippon Chemical Industry Co., Ltd., B-Parceram BTUP-2, D50: 2 μm, particle size D90: 2.8 μm, relative dielectric constant (1 MHz): 1500, specific surface area: 0.8 m ² /g, shape: crushed, content of particles with a particle size of 0.5 μm or less: 13% by mass)
(3) Inorganic filler (b) having a dielectric constant (1 MHz) of less than 6
Silica particles 1: Silica (manufactured by Admatechs Co., Ltd., SC-C6, D50: 2.0 μm, particle size D90: 8 μm, relative dielectric constant (1 MHz): 4, specific surface area: 2.0 m ² /g, shape: spherical, content of particles with a particle size of 0.5 μm or less: 19% by mass)
Silica particles 2: Silica (manufactured by Admatechs Co., Ltd., SC-2500-SQ, D50: 0.55 μm, particle size D90: 1.0 μm, relative dielectric constant (1 MHz): 4, specific surface area: 6.4 m ² /g, shape: spherical, content of particles with a particle size of 0.5 μm or less: 54% by mass)
(4) Cyanate resin (C)
Cyanate resin 1: Novolac type cyanate resin, manufactured by Lonza, product name PT-30
Cyanate resin 2: bisphenol A type cyanate resin, manufactured by Lonza, product name BA-230S, solid content 75% by weight, methyl ethyl ketone 25% by weight
(5) Coumarone resin (D)
Coumarone resin 1: indene-coumaron-styrene copolymer containing a phenol group at the end (manufactured by Nippon Paint Chemical Industry Co., Ltd., V-120S, weight average molecular weight: 950, hydroxyl value: 30 mg KOH/g)
(6) Coupling Agents Coupling Agent 1: N-phenyl-γ-aminopropyltrimethoxysilane (manufactured by Dow Corning Toray Co., Ltd., CF4083)
(7) Others/Catalyst: Shikoku Chemical Industry Co., Ltd., "2PZ-PW"

In each of the examples and comparative examples, the obtained resin varnish P (resin composition) was used to prepare a resin film with a carrier, a prepreg, a printed wiring board, and a semiconductor package as follows.

(Resin film with carrier: preparation of resin sheet)
The obtained resin varnish P was applied to one side of a 38 μm-thick PET film using a comma coater device so that the total thickness of the resin layer after drying would be 30 μm, and this was dried for 3 minutes in a drying device at 160° C. to obtain a resin sheet (resin film with carrier) in which a resin film was laminated on the PET film.

(Prepreg)
The obtained resin varnish was impregnated into a glass woven fabric (cloth type #1078, E glass, basis weight 47.5 g/m2) using a coating device, and dried for 4 minutes in a hot air dryer at 150°C to obtain a prepreg with a thickness of 80 µm.

(Laminated plate)
Ultra-thin copper foil (Mitsui Mining & Smelting Co., Ltd., Microthin FL, 1.5 μm) was laminated on both sides of the prepreg, and the laminate was heated and pressurized for 2 hours at a pressure of 3 MPa and a temperature of 225° C. to obtain a laminate with metal foil. The thickness of the core layer (portion made of resin substrate) of the obtained laminate with metal foil was 0.080 mm.

(Fabrication of printed wiring boards)
After the ultra-thin copper foil layer on the surface of the resin substrate with metal foil obtained in the previous section was roughened to a thickness of about 1 μm, a through hole of φ80 μm for interlayer connection was formed by a carbon dioxide laser. Then, the substrate was immersed in a swelling solution (Swelling Dip Securigant P, manufactured by Atotech Japan) at 60° C. for 10 minutes, and further immersed in an aqueous potassium permanganate solution (Concentrate Compact CP, manufactured by Atotech Japan) at 80° C. for 20 minutes, neutralized, and desmeared in the through hole. Next, electroless copper plating was performed to a thickness of 0.5 μm, a resist layer for electrolytic copper plating was formed to a thickness of 18 μm, pattern copper plating was performed, and post-cured by heating at a temperature of 150° C. for 30 minutes. Next, the plating resist was peeled off and the entire surface was flash etched to obtain an inner layer core circuit board with a remaining copper of 60% and a pattern of L/S=15/15 μm.
Next, the prepregs obtained in the examples were placed on both sides of the inner layer core circuit board, and an ultra-thin copper foil (Mitsui Mining & Smelting Co., Ltd., Microthin FL, 1.5 μm) was layered on top of them, and the resulting laminate was heated and pressurized at a pressure of 3 MPa and a temperature of 225° C. for 2 hours to obtain a multilayer laminate with metal foil.
Next, blind vias were formed in the multilayer laminate by a carbon dioxide laser. The inside of the via was immersed in a swelling liquid (Swelling Dip Securigant P, manufactured by Atotech Japan) at 60°C for 10 minutes, and then in an aqueous potassium permanganate solution (Concentrate Compact CP, manufactured by Atotech Japan; sodium permanganate concentration 60 g/l, NaOH concentration 45 g/l) at 80°C for 20 minutes, and then neutralized to perform a desmear treatment on the inside of the via.
After the process of degreasing, catalyst application, and activation, an electroless copper plating film of about 0.5 μm was formed, a resist was formed, and a pattern of electroplated copper of 20 μm was formed using the electroless copper plating film as a power supply layer, and circuit processing was performed. Next, annealing was performed for 60 minutes at 200 ° C. in a hot air drying device, and the power supply layer was removed by flash etching. Next, a solder resist layer was formed, and an opening was formed so that the semiconductor element mounting pad and the like were exposed. Finally, a plating layer consisting of an electroless nickel plating layer of 3 μm and an electroless gold plating layer of 0.1 μm was formed on the circuit layer exposed from the solder resist layer, and the obtained board was cut into a size of 50 mm × 50 mm to obtain a printed wiring board.

(Semiconductor package manufacturing)
The semiconductor package was obtained by mounting a semiconductor element (TEG chip, size 10 mm x 10 mm, thickness 0.1 mm) having solder bumps on the obtained printed wiring board by hot pressing using a flip chip bonder. Next, the solder bumps were melted and bonded in an IR reflow furnace, and then liquid sealing resin (manufactured by Sumitomo Bakelite Co., Ltd., CRP-4152S) was filled, and the liquid sealing resin was then cured to obtain a semiconductor package. The liquid sealing resin was cured at a temperature of 150°C for 120 minutes. The solder bumps of the semiconductor element were formed of a eutectic of Sn/Pb composition. Finally, the semiconductor package was obtained by dividing the semiconductor element into pieces of 14 mm x 14 mm size using a router.

The resin film with carrier, printed wiring board, and semiconductor package obtained using the above-mentioned resin varnish P (resin composition) were evaluated based on the following evaluation items and in accordance with the judgment criteria shown in Table 2. The results are shown in Table 1.

(1) Dielectric constant and dielectric loss tangent Four 30 μm thick resin films of the obtained resin film with a carrier were stacked, and heated and pressed for 2 hours using a hot press with copper foil at 225° C. and 1 kgf/mm ² to cure the resin film. The copper foil of the obtained cured product was then removed by etching to produce a cured product as a sample.
The dielectric constant and dielectric loss tangent at 10 GHz of the resulting cured product were measured by a cavity resonator method.

(2) Complex Dynamic Viscosity The PET film (carrier substrate) was peeled off from the resulting resin film with carrier, and the resin film in a B-stage state was prepared as a measurement sample.
Next, a dynamic viscoelasticity test was carried out on this measurement sample using a dynamic viscoelasticity measuring device (manufactured by Anton Paar, device name Physica MCR-301) under the following conditions to measure the complex dynamic viscosity.
(conditions)
Frequency: 62.83rad/sec
Measurement temperature: 50-200℃
Heating rate: 3°C/min
Geometry: Parallel plate Plate diameter: 10 mm
Plate spacing: 0.1 mm
Load (normal force): 0N (constant)
Strain: 0.3%
Measurement atmosphere: Air

(3) Peel strength The peel strength was measured in accordance with JIS C 6481. The sample used was a laminate with a metal foil obtained, electroplated with copper of 30 μm.

(4) Glass transition temperature: This was measured using a dynamic viscoelasticity device in accordance with JIS C-6481 (DMA method). The sample used was a laminate with a metal foil from which copper had been removed by etching.

(5) Thermal expansion coefficient The thermal expansion coefficient was measured by preparing a 4 mm x 20 mm test piece using a TMA (thermomechanical analysis) device (Q400, manufactured by TA Instruments) and measuring the linear expansion coefficient (CTE) at 50 to 100°C in the second cycle under the conditions of a temperature range of 30 to 300°C, 10°C/min, and a load of 5 g. The sample used was a laminate with metal foil that had been etched to remove the copper.

(6) Laser processability The periphery of the bottom of the via hole of the above printed wiring board was observed with a scanning electron microscope (SEM), and the maximum smear length from the wall surface of the bottom of the via hole was measured from the obtained image. The smear removability was evaluated according to the criteria from the maximum smear length. In addition, the plating penetration length was observed.

(7) Moldability The moldability was evaluated according to the following criteria: after etching the entire surface of the outer copper foil of the printed wiring board, the embeddability into the inner layer pattern was visually inspected and a cross section was observed.

(8) Moisture Absorption Solder Heat Resistance All of the copper foil on a metal foil-attached laminate was etched away from a 50 mm × 50 mm square sample except for half of one side of the sample. The sample was then treated for a predetermined time at 121°C and 2 atm in a pressure cooker tester (manufactured by Espec Corp.) and then floated in a solder bath at 260°C for 60 seconds. The appearance of the sample was visually inspected for any abnormal changes and evaluated according to the criteria.

(9) Insulation The through-hole insulation reliability was evaluated by continuously measuring the through-hole wall spacing of 0.1 mm in the printed wiring board under the conditions of an applied voltage of 5.5 V, a temperature of 130° C., and a humidity of 85%, and was determined according to the standard. The measurement was terminated when the insulation resistance value became less than 106Ω.

10 Resin film with carrier 20 Resin film 30 Carrier base material 50 Cover film 100 Core layer 102 Insulating layer 104 Via hole 106 Electroless metal plating film 108 Metal layer 200 Semiconductor package 202 Electroless metal plating film 204 Resist 206 Opening 208 Electrolytic metal plating layer 210 Opening 220 Metal layer 230 Solder resist layer 240 Semiconductor element 250 Solder bump 260 Sealing material layer

Claims (13)

A high dielectric resin composition comprising: an epoxy resin (A), an inorganic filler (B) having a dielectric constant (1 MHz) of 6 or more, an inorganic filler (b) having a dielectric constant (1 MHz) of less than 6, a cyanate resin (C), and a coumarone resin (D),
the epoxy resin (A) comprises at least one selected from the group consisting of biphenyl-type epoxy resins and phenol aralkyl-type epoxy resins,
The inorganic filler (B) contains one or more selected from the group consisting of titanium oxide, alumina, and barium titanate,
The content of the inorganic filler (B) is 30% by mass or less and 80% by mass or less with respect to the total amount of the high dielectric resin composition,
A cured product of the high dielectric resin composition has a dielectric constant (Dk: εr) of 4 to 10 at 10 GHz, and a dielectric loss tangent (Df: tan δ) of 0.003 to 0.015 at 10 GHz. The high dielectric resin composition according to claim 1, wherein the inorganic filler (B) does not include one having a perovskite structure. The high dielectric resin composition according to claim 1 or 2, wherein the peel strength of the cured film made of the high dielectric resin composition against copper foil is 0.5 kN/m or more. The high dielectric resin composition according to any one of claims 1 to 3, wherein the minimum value of the complex dynamic viscosity η1 of the high dielectric resin composition in a dynamic viscoelasticity test at a measurement range of 50 to 200°C, a heating rate of 3°C/min, and a frequency of 62.83 rad/sec is 50 to 2000 Pa·s. The highly dielectric resin composition according to any one of claims 1 to 4, wherein the inorganic filler (B) is surface-treated with an inorganic substance and an organic substance. The high dielectric resin composition according to any one of claims 1 to 5, wherein the cyanate resin (C) contains a butadiene-modified cyanate. The highly dielectric resin composition according to any one of claims 1 to 6, wherein the inorganic filler (b) having a dielectric constant (1 MHz) of less than 6 is one or more selected from the group consisting of talc, calcined clay, uncalcined clay, mica, glass, titanium oxide, alumina, boehmite, silica, fused silica, calcium carbonate, magnesium carbonate, hydrotalcite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, barium sulfate, calcium sulfate, calcium sulfite, zinc borate, barium metaborate, aluminum borate, calcium borate, sodium borate, aluminum nitride, boron nitride, silicon nitride, and carbon nitride. A cured product of the highly dielectric resin composition according to any one of claims 1 to 7 . A prepreg comprising a fiber base material in the highly dielectric resin composition according to any one of claims 1 to 7 . A laminate comprising the prepreg according to claim 9 and a metal layer disposed on at least one surface of the prepreg. A carrier substrate;
A resin film formed on the carrier substrate and made of the high dielectric resin composition according to claim 1 ;
A resin film with a carrier. A printed wiring board comprising an insulating layer made of a cured product of the highly dielectric resin composition according to claim 1 . The printed wiring board according to claim 12 ;
a semiconductor element mounted on a circuit layer of the printed wiring board or embedded in the printed wiring board.

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