Resin composition, resin-attached metal foil, laminate, printed wiring board, and semiconductor package

Abstract

The present invention pertains to: a resin composition that is for use in forming a resin layer for a resin-attached metal foil including a metal foil and a resin layer laminated on one surface of the metal foil, and that contains (A) an epoxy resin including an aliphatic ring and having an epoxy equivalent of 240 g / eq or less; and a resin-attached metal foil, a laminate, a printed wiring board, and a semiconductor package, in all of which the resin composition is used.

Description

Resin composition, resin-coated metal foil, laminate, printed wiring board, and semiconductor package

[0001] The present embodiment relates to a resin composition, a resin-coated metal foil, a laminate, a printed wiring board, and a semiconductor package.

[0002] Due to the recent trend toward smaller electronic devices and higher performance, printed wiring boards are required to have higher wiring density and higher integration than ever before, as well as thinner substrates. Resin-coated metal foils are sometimes used as materials for forming insulating layers in printed wiring boards (see, for example, Patent Document 1). Resin-coated metal foils have a resin layer on a metal foil that does not contain a fiber substrate such as glass cloth. The resin layer is typically a thermosetting resin adjusted to a B-stage state, and the resin layer forms an insulating layer by embedding the circuits of a circuit board and curing it. Resin-coated metal foils can be made thinner because the resin layer does not contain a fiber substrate, and the resulting insulating layer has excellent smoothness and fine wiring properties, making them suitable for higher wiring density and higher integration in printed wiring boards.

[0003] Japanese Patent Application Laid-Open No. 2018-1632

[0004] It is required that the resin-coated metal foil does not crack in the resin layer in a B-stage state during the manufacturing process or during use. According to the studies of the present inventors, a method of adding a highly flexible component to the resin layer is effective in suppressing cracking in the resin layer, but it has been found that the insulating layer formed from the resin layer in which cracking is suppressed by this method has room for improvement in interlayer insulation.

[0005] In view of the current situation, the present embodiment aims to provide a resin composition capable of producing a resin-coated metal foil that suppresses the occurrence of cracks in the resin layer and has excellent interlayer insulation properties for the insulating layer formed from the resin layer, as well as a resin-coated metal foil, a laminate, a printed wiring board, and a semiconductor package that use the resin composition.

[0006] That is, this embodiment provides the following [1] to

[12] . [1] A resin composition used to form a resin layer of a resin-coated metal foil having a metal foil and a resin layer laminated on one surface of the metal foil, the resin composition containing (A) an epoxy resin having an aliphatic ring and having an epoxy equivalent of 240 g / eq or less. [2] The resin composition according to the above [1], wherein the aliphatic ring is a fused ring. [3] The resin composition according to the above [1], wherein the fused ring is a tricyclo[5.2.1.0 ２，６ ] The resin composition according to the above [2], wherein the (A) component is a difunctional epoxy resin. [4] The resin composition according to any one of the above [1] to [3], wherein the (A) component is a bifunctional epoxy resin. [5] The resin composition according to any one of the above [1] to [4], wherein the (A) component is an epoxy resin not having a novolac structure. [6] The resin composition according to any one of the above [1] to [5], further comprising (B) a maleimide resin. [7] The resin composition according to any one of the above [1] to [6], further comprising (C) an inorganic filler. [8] A resin-coated metal foil having a metal foil and a resin layer laminated on one side of the metal foil, wherein the resin layer contains the resin composition according to any one of the above [1] to [7] or a semi-cured product thereof. [9] The resin-coated metal foil according to the above [8], wherein the metal foil is a copper foil.

[10] A laminate having a metal foil and a cured product of the resin composition according to any one of the above [1] to [7].

[11] A printed wiring board having a cured product of the resin composition according to any one of [1] to [7] above.

[12] A semiconductor package having the printed wiring board according to

[11] above and a semiconductor element.

[0007] According to this embodiment, it is possible to provide a resin composition that can be used to produce a resin-coated metal foil that suppresses the occurrence of cracks in the resin layer and has excellent interlayer insulation properties for the insulating layer formed from the resin layer, as well as a resin-coated metal foil, a laminate, a printed wiring board, and a semiconductor package that use the resin composition.

[0008] In this specification, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. For example, a numerical range "X to Y" (X and Y are real numbers) means a numerical range that is equal to or greater than X and equal to or less than Y. In this specification, the term "X or greater" means X and a numerical value that exceeds X. In addition, the term "Y or less" in this specification means Y and a numerical value that is less than Y. The lower limit and upper limit of a numerical range described in this specification can be arbitrarily combined with the lower limit or upper limit of another numerical range. In the numerical ranges described in this specification, the lower limit or upper limit of that numerical range may be replaced with a value shown in the examples.

[0009] Unless otherwise specified, each of the components and materials exemplified in this specification may be used alone or in combination of two or more. In this specification, when a resin composition contains a plurality of substances corresponding to each component, the content of each component in the resin composition means the total amount of the plurality of substances present in the resin composition, unless otherwise specified.

[0010] In this specification, the term "solid content" refers to components other than the solvent, and includes those that are liquid at room temperature. Here, in this specification, room temperature means 25°C.

[0011] The weight average molecular weight (Mw) in this specification refers to a value measured in terms of polystyrene by gel permeation chromatography (GPC). Specifically, the weight average molecular weight (Mw) in this specification can be measured by the method described in the examples.

[0012] In this specification, the term "semi-cured product" is synonymous with a resin composition in a B-stage state in JIS K 6800:2006, and the term "cured product" is synonymous with a resin composition in a C-stage state in JIS K 6800:2006.

[0013] In this specification, when the term "layer" is used, not only a solid layer but also a layer that is not a solid layer but has some islands, has holes, or has an unclear interface with an adjacent layer is included in the "layer".

[0014] The mechanism of action described in this specification is speculation and does not limit the mechanism by which the effects of this embodiment are achieved.

[0015] Any combination of the features described in this specification is also included in this embodiment.

[0016] [Resin Composition] The resin composition of the present embodiment is a resin composition used to form a resin layer of a resin-coated metal foil having a metal foil and a resin layer laminated on one side of the metal foil, and is a resin composition containing (A) an epoxy resin having an aliphatic ring and an epoxy equivalent of 240 g / eq or less.

[0017] In this specification, each component may be abbreviated as component (A), component (B), etc., and similar abbreviations may be used for other components.

[0018] The reason why the resin composition of this embodiment can produce a resin-coated metal foil that suppresses cracking in the resin layer and has excellent interlayer insulation properties for the insulating layer formed from the resin layer is unclear, but is presumed to be as follows. The property of suppressing cracking in the resin layer may be referred to as "crack resistance" hereinafter. The resin composition of this embodiment contains (A) an epoxy resin having an aliphatic ring and an epoxy equivalent of 240 g / eq or less. The aliphatic ring in component (A) has high affinity with metal foil, and it is believed that the resin layer formed from the resin composition of this embodiment containing component (A) has excellent adhesion to the metal foil. This suppression of cracking in the resin layer is presumed to be due to the fact that cracks accompanying peeling from the metal foil are less likely to occur. Furthermore, since component (A) has an epoxy equivalent of 240 g / eq or less, the crosslink density of the cured product is high, making it less susceptible to deterioration, moisture absorption, and other issues due to heating environments. This is presumed to be the reason for the improved interlayer insulation. Below, each component that may be contained in the resin composition of this embodiment is described in order.

[0019] <(A) Epoxy Resin Having an Aliphatic Ring and an Epoxy Equivalent of 240 g / eq or Less> The resin composition of the present embodiment contains, as component (A), an epoxy resin having an aliphatic ring and an epoxy equivalent of 240 g / eq or less. One type of component (A) may be used alone, or two or more types may be used in combination.

[0020] The epoxy equivalent of component (A) is 240 g / eq or less from the viewpoint of suppressing cracking in the resin layer and ensuring excellent interlayer insulation of the insulating layer formed from the resin layer. From the same viewpoints as above, the epoxy equivalent of component (A) is preferably 220 g / eq or less, more preferably 200 g / eq or less, and even more preferably 180 g / eq or less. From the viewpoints of ease of handling and availability of component (A), the lower limit of the epoxy equivalent of component (A) is preferably 80 g / eq or more, more preferably 100 g / eq or more, even more preferably 120 g / eq or more, and particularly preferably 140 g / eq or more. From the same viewpoints as above, the epoxy equivalent of component (A) is preferably 80 to 240 g / eq, more preferably 100 to 220 g / eq, even more preferably 120 to 200 g / eq, and particularly preferably 140 to 180 g / eq. The epoxy equivalent is the mass of the resin per epoxy group (g / eq), and can be measured according to the method specified in JIS K 7236:2001.

[0021] The molecular weight of component (A) is preferably 150 to 1,000, more preferably 200 to 500, and even more preferably 220 to 300, from the viewpoint of the interlayer insulation of the insulating layer and the viewpoint of suppressing volatilization of component (A).

[0022] From the viewpoint of improving the adhesion of the resin layer to the metal foil, the component (A) is preferably liquid at 25°C. From the viewpoint of improving handleability and the adhesion of the resin layer to the metal foil, the viscosity of the component (A) at 25°C is preferably 100 to 1,000 mPa s, more preferably 150 to 500 mPa s, and even more preferably 200 to 300 mPa s. The viscosity of the component (A) can be measured in accordance with JIS Z 8803:2011.

[0023] From the viewpoints of the crack resistance of the resin layer and the interlayer insulation of the insulating layer, the number of epoxy groups contained in one molecule of component (A) is preferably 1 or more, more preferably 2 or more, and even more preferably 2. That is, component (A) is more preferably a bifunctional epoxy resin. Furthermore, from the viewpoints of the crack resistance of the resin layer and the interlayer insulation of the insulating layer, component (A) is preferably an epoxy resin without a novolac structure.

[0024] From the viewpoint of the crack resistance of the resin layer and the interlayer insulation of the insulating layer, the aliphatic ring contained in component (A) is preferably an aliphatic ring having 5 to 20 ring carbon atoms, more preferably an aliphatic ring having 6 to 18 ring carbon atoms, still more preferably an aliphatic ring having 8 to 14 ring carbon atoms, and particularly preferably an aliphatic ring having 8 to 12 ring carbon atoms. In this specification, the term "number of ring carbon atoms" refers to the number of carbon atoms necessary to form the ring and does not include the number of carbon atoms of substituents on the ring. For example, both the cyclohexane skeleton and the methylcyclohexane skeleton have 6 ring carbon atoms.

[0025] The aliphatic ring contained in component (A) is preferably a fused ring from the viewpoint of the crack resistance of the resin layer and the interlayer insulation of the insulating layer. The fused ring is preferably a fused ring of two or more rings, more preferably a fused ring of two to four rings, and even more preferably a fused ring of three rings. Specific examples of the fused ring include a norbornane ring, a decalin ring, a bicycloundecane ring, a tricyclo[5.2.1.0] ring, a cyclopentyl ring, a cyclopentyl group ... ２，６ ]decane ring, etc., among which tricyclo[5.2.1.0 ２，６ ] A decane ring is preferred. These condensed rings usually have a substituent containing an epoxy group, and may or may not have a substituent other than the substituent containing an epoxy group.

[0026] The component (A) preferably has a divalent group represented by the following general formula (A-1) as a group containing an aliphatic ring. The aliphatic ring contained in the divalent group represented by the following general formula (A-1) is tricyclo[5.2.1.0] ２，６ ] is a decane ring.

[0027] (In the formula, R Ａ１ represents an alkyl group having 1 to 12 carbon atoms, and may be substituted anywhere on the aliphatic ring. １ is an integer from 0 to 6. * indicates a binding site.)

[0028] In the above general formula (A-1), R Ａ１ Examples of the alkyl group having 1 to 12 carbon atoms represented by include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and an n-pentyl group.

[0029] In the general formula (A-1), m １ is an integer of 0 to 6, preferably an integer of 0 to 2, and more preferably 0. １ is an integer of 2 or more, a plurality of R Ａ１ Each R may be the same or different. Ａ１ may be substituted on the same carbon atom or on different carbon atoms, to the extent possible.

[0030] In the above general formula (A-1), * represents a bonding site to another structure. The single bond having the bonding site * may be bonded to any carbon atom on the aliphatic ring.

[0031] As the component (A) having a divalent group represented by the above general formula (A-1), a compound represented by the following general formula (A-2) is preferred.

[0032] (In the formula, R Ａ１ and m １ is the same as in the general formula (A-1) above.

[0033] The content of component (A) in the resin composition of this embodiment is preferably 5 to 70 mass%, more preferably 10 to 60 mass%, even more preferably 15 to 40 mass%, and particularly preferably 19 to 25 mass%, relative to the total amount (100 mass%) of the resin components in the resin composition of this embodiment. When the content of component (A) is equal to or greater than the above-mentioned lower limit, the crack resistance of the resin layer and the interlayer insulation of the insulating layer tend to be more improved. Furthermore, when the content of component (A) is equal to or less than the above-mentioned upper limit, the heat resistance of the resin layer tends to be more improved.

[0034] Here, in this specification, the term "resin component" refers to a resin and a compound that forms a resin through a curing reaction. In the resin composition of this embodiment, for example, component (A), component (B), component (D), etc. correspond to the resin component. When the resin composition of this embodiment contains, as an optional component, a resin or a compound that forms a resin through a curing reaction in addition to the above components, these optional components are also included in the resin component. On the other hand, components (C) and (E) described below are not included in the resin component.

[0035] The content of the resin component in the resin composition of this embodiment is preferably 10 to 90 mass%, more preferably 30 to 80 mass%, and even more preferably 50 to 70 mass%, relative to the total solid content (100 mass%) of the resin composition of this embodiment, from the viewpoints of the crack resistance of the resin layer, the interlayer insulation of the insulating layer, and the conductor adhesion.

[0036] <(B) Maleimide Resin> The resin composition of this embodiment preferably further contains a (B) maleimide resin. By containing the (B) maleimide resin in the resin composition of this embodiment, the heat resistance and conductor adhesion of the insulating layer tend to be more improved. One type of (B) maleimide resin may be used alone, or two or more types may be used in combination.

[0037] The (B) maleimide resin is preferably one or more selected from the group consisting of maleimide resins having one or more N-substituted maleimide groups and derivatives of such maleimide resins. In the following description, a maleimide resin having one or more N-substituted maleimide groups may be referred to as a "maleimide resin (BX)" or a "(BX) component." Furthermore, a derivative of a maleimide resin having one or more N-substituted maleimide groups may be referred to as a "maleimide resin derivative (BY)" or a "(BY) component."

[0038] (Maleimide Resin (BX)) From the viewpoint of conductor adhesion and heat resistance of the insulating layer, the maleimide resin (BX) is preferably an aromatic maleimide resin having two or more N-substituted maleimide groups, and more preferably an aromatic bismaleimide resin having two N-substituted maleimide groups. In this specification, "aromatic maleimide resin" means a compound having an N-substituted maleimide group directly bonded to an aromatic ring. In addition, in this specification, "aromatic bismaleimide resin" means a compound having two N-substituted maleimide groups directly bonded to an aromatic ring. In addition, in this specification, "aromatic polymaleimide resin" means a compound having three or more N-substituted maleimide groups directly bonded to an aromatic ring. In addition, in this specification, "aliphatic maleimide resin" means a compound having an N-substituted maleimide group directly bonded to an aliphatic hydrocarbon.

[0039] The maleimide resin (BX) is preferably a maleimide resin represented by the following general formula (B-1).

[0040] (In the formula, X Ｂ１ is a divalent organic group.

[0041] X in the above general formula (B-1) Ｂ１ Examples of the divalent organic group represented by the formula (B-3), (B-4), (B-5), or (B-6) below include divalent organic groups represented by the formula (B-2), (B-3), (B-4), (B-5), or (B-6) below.

[0042] (In the formula, R Ｂ１ are each independently an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom. Ｂ１ is an integer from 0 to 4. * represents a binding site.)

[0043] R in the above general formula (B-2) Ｂ１Examples of the aliphatic hydrocarbon group having 1 to 5 carbon atoms represented by include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl; alkenyl groups having 2 to 5 carbon atoms; and alkynyl groups having 2 to 5 carbon atoms. The aliphatic hydrocarbon group having 1 to 5 carbon atoms may be either linear or branched. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. In the general formula (B-2) above, n Ｂ１ is preferably an integer of 0 to 2, more preferably 0.

[0044] (In the formula, R Ｂ２ and R Ｂ３ are each independently an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom. Ｂ２ n is an alkylene group having 1 to 5 carbon atoms, an alkylidene group having 2 to 5 carbon atoms, an ether group, a sulfide group, a sulfonyl group, a carbonyloxy group, a keto group, a single bond, or a divalent organic group represented by the following general formula (B-3-1): Ｂ２ and n Ｂ３ are each independently an integer of 0 to 4. * represents a binding site.

[0045] R in the above general formula (B-3) Ｂ２ and R Ｂ３ The aliphatic hydrocarbon group having 1 to 5 carbon atoms and the halogen atom represented by R Ｂ１ The same as X in the above general formula (B-3) can be mentioned. Ｂ２ Examples of the alkylene group having 1 to 5 carbon atoms represented by X include a methylene group, a 1,2-dimethylene group, a 1,3-trimethylene group, a 1,4-tetramethylene group, and a 1,5-pentamethylene group. Among these, an alkylene group having 1 to 3 carbon atoms is preferred, and a methylene group is more preferred. Ｂ２ Examples of the alkylidene group having 2 to 5 carbon atoms represented by include an ethylidene group, a propylidene group, an isopropylidene group, a butylidene group, an isobutylidene group, a pentylidene group, and an isopentylidene group. Ｂ２ and n Ｂ３is preferably an integer of 0 to 3, more preferably 0 or 2. Ｂ２ or n Ｂ３ is an integer of 2 or more, a plurality of R Ｂ２ R Ｂ３ They may be the same or different from each other.

[0046] X in the above general formula (B-3) Ｂ２ The divalent organic group represented by formula (B-3-1) is as follows:

[0047] (In the formula, R Ｂ４ and R Ｂ５ are each independently an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom. Ｂ３ is an alkylene group having 1 to 5 carbon atoms, an alkylidene group having 2 to 5 carbon atoms, an ether group, a sulfide group, a sulfonyl group, a carbonyloxy group, a keto group, or a single bond. Ｂ４ and n Ｂ５ are each independently an integer of 0 to 4. * represents a binding site.

[0048] R in the above general formula (B-3-1) Ｂ４ and R Ｂ５ The aliphatic hydrocarbon group having 1 to 5 carbon atoms and the halogen atom represented by R Ｂ１ The same as X in the above general formula (B-3-1) can be mentioned. Ｂ３ The alkylene group having 1 to 5 carbon atoms and the alkylidene group having 2 to 5 carbon atoms represented by the above X Ｂ２ The same as those in the general formula (B-3-1) above are included. Ｂ４ and n Ｂ５ is preferably an integer of 0 to 2, more preferably 0. Ｂ４ or n Ｂ５ is an integer of 2 or more, a plurality of R Ｂ４ R Ｂ５ They may be the same or different from each other.

[0049] (In the formula, n Ｂ６ is an integer from 0 to 10. * represents a binding site.)

[0050] (In the formula, n Ｂ７ is a number between 0 and 5. * represents a binding site.)

[0051] (In the formula, R Ｂ６ and R Ｂ７ are each independently a hydrogen atom or an aliphatic hydrocarbon group having 1 to 5 carbon atoms. Ｂ８ is an integer from 1 to 8. * represents a binding site.)

[0052] R in the above general formula (B-6) Ｂ６ and R Ｂ７ The aliphatic hydrocarbon group having 1 to 5 carbon atoms and the halogen atom represented by R Ｂ１ The same as those mentioned above can be mentioned. Ｂ８ is an integer of 2 or more, a plurality of R Ｂ６ R Ｂ７ They may be the same or different from each other.

[0053] (Maleimide Resin Derivative (BY)) The maleimide resin derivative (BY) is preferably a resin containing a structure derived from a maleimide resin having one or more N-substituted maleimide groups (i.e., the maleimide resin (BX)) and a structure derived from a diamine compound [hereinafter, this may be referred to as an "aminomaleimide resin"].

[0054] Examples of structures derived from the maleimide resin (BX) contained in the aminomaleimide resin include structures formed by a Michael addition reaction between at least one N-substituted maleimide group among the N-substituted maleimide groups contained in the maleimide resin (BX) and an amino group contained in a diamine compound. The content of the structure derived from the maleimide resin (BX) in the aminomaleimide resin is preferably 5 to 95% by mass, more preferably 30 to 93% by mass, and even more preferably 60 to 90% by mass. The structure derived from the maleimide resin (BX) contained in the aminomaleimide resin may be one type alone or two or more types.

[0055] An example of a structure derived from a diamine compound contained in an aminomaleimide resin is a structure formed by a Michael addition reaction between one or both of two amino groups contained in a diamine compound and an N-substituted maleimide group contained in the maleimide resin (BX). The content of the structure derived from a diamine compound in the aminomaleimide resin is preferably 5 to 95% by mass, more preferably 7 to 70% by mass, and even more preferably 10 to 40% by mass. The structure derived from a diamine compound contained in the aminomaleimide resin may be one type alone or two or more types.

[0056] The amino group of the diamine compound is preferably a primary amino group. Examples of the diamine compound include an aromatic diamine compound having two amino groups directly bonded to an aromatic ring, and a silicone compound having two primary amino groups. Examples of the aromatic diamine compound include 4,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisaniline, 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline, and 3,3'-diethyl-4,4'-diaminodiphenylmethane.

[0057] When the resin composition of this embodiment contains a (B) maleimide resin, the content of the (B) maleimide resin is preferably 30 to 90 mass%, more preferably 40 to 85 mass%, and even more preferably 50 to 80 mass%, relative to the total amount (100 mass%) of resin components in the resin composition of this embodiment. When the content of the (B) maleimide resin is equal to or greater than the above-mentioned lower limit, the heat resistance, moldability, processability, and conductor adhesion of the insulating layer tend to be improved. On the other hand, when the content of the (B) maleimide resin is equal to or less than the above-mentioned upper limit, the dielectric properties of the insulating layer tend to be improved.

[0058] When the resin composition of the present embodiment contains a maleimide resin (B), the mass ratio of the component (A) to the component (B) in the resin composition of the present embodiment [(A) / (B)] is preferably 0.05 to 5, more preferably 0.1 to 1, and even more preferably 0.2 to 0.7, from the viewpoints of the crack resistance of the resin layer, the interlayer insulation of the insulating layer, and the conductor adhesion.

[0059] <(C) Inorganic Filler> The resin composition of this embodiment preferably further contains (C) an inorganic filler. By containing (C) an inorganic filler, the resin composition of this embodiment tends to provide the insulating layer with better low thermal expansion and heat resistance. The resin layer of the resin-coated metal foil of this embodiment is one in which cracking is suppressed, so the amount of inorganic filler that can cause cracking can be increased, and an insulating layer with excellent low thermal expansion and other properties can be formed. One type of (C) inorganic filler may be used alone, or two or more types may be used in combination.

[0060] (C) inorganic filler can be exemplified by silica, alumina, titanium oxide, mica, beryllia, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, clay, talc, aluminum borate, silicon carbide etc.Among these, from the viewpoint of low thermal expansion, heat resistance and flame retardancy of insulating layer, silica, alumina, mica and talc are preferred, silica and alumina are more preferred, and silica is even more preferred.As silica, from the viewpoint of dispersibility and moldability, amorphous silica is preferred.

[0061] (C) Average particle diameter of inorganic filler (D ５０ From the viewpoint of dispersibility of the inorganic filler (C) and fine wiring properties, the average particle diameter (D) of the inorganic filler (C) is preferably 0.01 to 20 μm, more preferably 0.1 to 10 μm, even more preferably 0.2 to 1 μm, and particularly preferably 0.3 to 0.8 μm. ５０The average particle size of the inorganic filler (C) can be measured, for example, by a particle size distribution analyzer using a laser diffraction scattering method.

[0062] The shape of the (C) inorganic filler may be, for example, spherical or crushed, with spherical being preferred. The (C) inorganic filler may be surface-treated with a surface treatment agent such as a silane coupling agent in order to improve dispersibility and adhesion to the organic component.

[0063] When the resin composition of this embodiment contains (C) an inorganic filler, the content of the (C) inorganic filler is preferably 10 to 70 mass%, more preferably 20 to 60 mass%, and even more preferably 30 to 50 mass%, based on the total solids content (100 mass%) of the resin composition. When the content of the (C) inorganic filler is equal to or greater than the above-mentioned lower limit, the insulating layer tends to have better low thermal expansion and heat resistance. On the other hand, when the content of the (C) inorganic filler is equal to or less than the above-mentioned upper limit, the insulating layer tends to have better moldability and conductor adhesion.

[0064] <(D) Elastomer> The resin composition of this embodiment may further contain an elastomer (D). When the resin composition of this embodiment contains the elastomer (D), the crack resistance of the resin layer tends to be further improved. The elastomer (D) may be used alone or in combination of two or more.

[0065] Examples of the (D) elastomer include styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic elastomers, silicone-based elastomers, and derivatives thereof. Among these, acrylic elastomers are preferred.

[0066] The weight average molecular weight (Mw) of the (D) elastomer is preferably 10,000 to 2,000,000, more preferably 100,000 to 1,500,000, and even more preferably 500,000 to 1,000,000, from the viewpoints of the crack resistance of the resin layer and the compatibility of the (D) component.

[0067] The (D) elastomer may have a reactive functional group. Examples of the reactive functional group include an epoxy group, a hydroxyl group, a carboxyl group, an amino group, an amide group, an isocyanato group, an acrylic group, a methacrylic group, and a vinyl group. Among these, an epoxy group is preferred. When the (D) elastomer has an epoxy group, the epoxy equivalent of the (D) elastomer is preferably 1,000 to 10,000 g / eq, more preferably 3,000 to 8,000 g / eq, and even more preferably 4,000 to 6,000 g / eq, from the viewpoints of the crack resistance of the resin layer and the handleability of the (D) elastomer.

[0068] When the resin composition of this embodiment contains the elastomer (D), the content of the elastomer (D) is preferably 1 to 30% by mass, more preferably 4 to 20% by mass, and even more preferably 7 to 15% by mass, relative to the total amount (100% by mass) of the resin components in the resin composition of this embodiment. When the content of the elastomer (D) is equal to or greater than the lower limit, cracking in the resin layer tends to be more easily suppressed. Furthermore, when the content of the elastomer (D) is equal to or less than the upper limit, the heat resistance of the insulating layer tends to be more easily improved.

[0069] <(E) Curing Accelerator> From the viewpoint of accelerating the curing reaction of the resin composition, the resin composition of the present embodiment preferably further contains (E) a curing accelerator. The (E) curing accelerator may be used alone or in combination of two or more.

[0070] (E) Examples of the curing accelerator include amine-based curing accelerators, imidazole-based curing accelerators, phosphorus-based curing accelerators, organometallic salts, acidic catalysts, and organic peroxides. In this embodiment, imidazole-based curing accelerators are not classified as amine-based curing accelerators. Examples of the amine-based curing accelerator include amine compounds having primary to tertiary amines, such as triethylamine, pyridine, tributylamine, and dicyandiamide; and quaternary ammonium compounds. Examples of the imidazole-based curing accelerator include imidazole compounds, such as methylimidazole, phenylimidazole, and 2-undecylimidazole; and isocyanate-masked imidazoles, such as the addition product of hexamethylene diisocyanate resin and 2-ethyl-4-methylimidazole. Examples of the phosphorus-based curing accelerator include tertiary phosphines, such as triphenylphosphine; and quaternary phosphonium compounds, such as the addition product of p-benzoquinone and tri-n-butylphosphine. Examples of organic metal salts include carboxylates of manganese, cobalt, zinc, etc. Examples of acidic catalysts include p-toluenesulfonic acid, etc. Examples of organic peroxides include dicumyl peroxide, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyne-3,2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, t-butylperoxyisopropyl monocarbonate, and α,α'-di(t-butylperoxy)diisopropylbenzene, etc. Among these, from the viewpoints of dielectric properties, heat resistance, adhesion to conductors, and elastic modulus, phosphorus-based curing accelerators are more preferred, and quaternary phosphonium compounds are even more preferred.

[0071] When the resin composition of this embodiment contains a curing accelerator (E), the content of the curing accelerator (E) is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, and even more preferably 0.1 to 1 part by mass, relative to the total amount (100 parts by mass) of the resin components in the resin composition of this embodiment. When the content of the curing accelerator (E) is equal to or greater than the above-mentioned lower limit, a sufficient curing acceleration effect tends to be easily obtained. Furthermore, when the content of the curing accelerator (E) is equal to or less than the above-mentioned upper limit, storage stability tends to be more easily improved.

[0072] <Other Components> The resin composition of the present embodiment may further contain, as necessary, one or more additives selected from the group consisting of resin materials other than the above components, antioxidants, heat stabilizers, antistatic agents, UV absorbers, pigments, colorants, lubricants, and other additives. Each of these may be used alone or in combination of two or more. The amount of these additives used is not particularly limited, and they may be used as needed within a range that does not impair the effects of the present embodiment.

[0073] (Organic Solvent) The resin composition of the present embodiment may contain an organic solvent from the viewpoint of facilitating handling and facilitating the production of the prepreg described below. One organic solvent may be used alone, or two or more organic solvents may be used in combination. Examples of the organic solvent include alcohol-based solvents such as ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether-based solvents such as tetrahydrofuran; aromatic hydrocarbon-based solvents such as toluene, xylene, and mesitylene; nitrogen-containing solvents such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone; sulfur-containing solvents such as dimethyl sulfoxide; and ester-based solvents such as γ-butyrolactone.

[0074] <Method for producing resin composition> The resin composition of this embodiment can be produced by mixing the components by a known method. At this time, the components may be dissolved or dispersed while stirring. The conditions such as the mixing order, temperature, and time are not particularly limited and may be set as desired depending on the types of raw materials, etc.

[0075] [Resin-Coated Metal Foil] The resin-coated metal foil of the present embodiment has a metal foil and a resin layer laminated on one side of the metal foil, and the resin layer contains the resin composition of the present embodiment or a semi-cured product thereof.

[0076] (Resin Layer) The thickness of the resin layer is preferably 5 to 1,000 μm, more preferably 10 to 500 μm, even more preferably 20 to 100 μm, and even more preferably 25 to 50 μm. When the thickness of the resin layer is equal to or greater than the above-mentioned lower limit, circuit embedding tends to be more favorable. Furthermore, when the thickness of the resin layer is equal to or less than the above-mentioned upper limit, it tends to be more suitable for high-density wiring. Note that, while increasing the thickness of the resin layer usually makes the resin layer more susceptible to cracking, the resin layer of the resin-coated metal foil of this embodiment is less susceptible to cracking, and therefore tends to make it easier to increase the thickness of the resin layer while suppressing cracking. The resin layer may be laminated on only one side of the metal foil, or on both sides.

[0077] (Metal foil) Examples of the metal foil include copper foil, tin foil, tin-lead alloy foil, and nickel foil. Among these, copper foil is preferred. The copper foil preferably has a copper content of 95% by mass or more. From the viewpoint of use in semiconductor packages, the metal foil is preferably one conforming to JIS standards (electrolytic copper foil for printed wiring boards: JIS C6512, rolled copper foil for printed wiring boards: JIS C6513) or IPC standards (IPC 4562 Standard Grades 1, 2, and 3).

[0078] The surface of the metal foil on which the resin layer is formed may be roughened from the viewpoint of adhesion. Furthermore, in addition to the roughening treatment, the metal foil may have secondary particles, tertiary particles, an anti-corrosion layer, a heat-resistant layer, or the like formed thereon using a single element selected from nickel, cobalt, copper, and zinc, or an alloy containing at least one of these. Furthermore, in addition to the above-mentioned layers, the surface may be further subjected to a surface treatment such as a chromate treatment or a silane coupling treatment.

[0079] The thickness of the metal foil may be adjusted appropriately depending on the application of the resin-coated metal foil, and is preferably 0.1 to 40 μm, more preferably 1 to 30 μm, and even more preferably 1.5 to 20 μm. When the thickness of the metal foil is equal to or greater than the above lower limit, the handleability of the resin-coated metal foil tends to be further improved. On the other hand, when the thickness of the metal foil is equal to or less than the above upper limit, it tends to be more suitable for achieving high wiring density.

[0080] The resin-coated metal foil of this embodiment is suitable as a resin-coated metal foil for forming an insulating layer of a printed wiring board such as a multilayer printed wiring board, or as a resin-coated metal foil for sealing a semiconductor in a semiconductor package.

[0081] <Method for producing resin-coated metal foil> The resin-coated metal foil of the present embodiment can be produced, for example, by applying the resin composition of the present embodiment containing an organic solvent (hereinafter, the resin composition containing an organic solvent may be referred to as a "resin varnish") to a metal foil, and then heating and drying it.

[0082] Examples of coating devices that can be used for applying the resin varnish include comma coaters, bar coaters, kiss coaters, roll coaters, gravure coaters, and die coaters. The drying conditions after applying the resin varnish are not particularly limited and can be determined appropriately depending on the content and boiling point of the organic solvent. For example, in the case of a resin varnish containing 40 to 60 mass% of an aromatic hydrocarbon solvent, the drying temperature is preferably 50 to 200°C, more preferably 80 to 150°C, and even more preferably 100 to 130°C, from the viewpoints of productivity and adequately B-staging the resin composition. Furthermore, in the case of the above-mentioned resin varnish, the drying time is preferably 1 to 30 minutes, more preferably 2 to 15 minutes, and even more preferably 3 to 10 minutes, from the viewpoints of productivity and adequately B-staging the resin composition.

[0083] [Laminate] The laminate of the present embodiment is a laminate having a cured product of the resin composition of the present embodiment and a metal foil. Note that a laminate having a metal foil is sometimes called a metal-clad laminate.

[0084] The metal of the metal foil may be the same as that used in the resin-coated metal foil of this embodiment.

[0085] The laminate of this embodiment can be produced, for example, by laminating the resin-coated metal foil of this embodiment and then hot-press molding. Hot-press molding can be performed using a multi-stage press, a multi-stage vacuum press, a continuous molding machine, an autoclave molding machine, or the like. The conditions for hot-press molding are not particularly limited, but can be, for example, a temperature of 100 to 300°C, a time of 10 to 300 minutes, and a pressure of 1.5 to 5 MPa.

[0086] [Printed Wiring Board] The printed wiring board of this embodiment is a printed wiring board having a cured product of the resin composition of this embodiment. The printed wiring board of this embodiment can be produced, for example, by forming a conductor circuit on one or more materials selected from the group consisting of a cured product of the prepreg of this embodiment, a cured product of the resin film of this embodiment, and a laminate by a known method. Furthermore, a multilayer printed wiring board can also be produced by further performing a multilayer adhesive process as necessary. The conductor circuit can be formed, for example, by appropriately performing drilling, metal plating, etching of metal foil, etc.

[0087] [Semiconductor Package] The semiconductor package of this embodiment is a semiconductor package including the printed wiring board of this embodiment and a semiconductor element. The semiconductor package of this embodiment can be manufactured, for example, by mounting a semiconductor chip, a memory, etc. on the printed wiring board of this embodiment by a known method.

[0088] The present embodiment will be specifically described below with reference to examples, although the present embodiment is not limited to the following examples.

[0089] [Method for measuring weight average molecular weight (Mw)] The weight average molecular weight (Mw) was measured by gel permeation chromatography (GPC) using a calibration curve obtained using standard polystyrene. The calibration curve was approximated by a cubic equation using standard polystyrene: TSKstandard POLYSTYRENE (Types: A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40) [manufactured by Tosoh Corporation, trade name]. The GPC measurement conditions are shown below. Apparatus: Pump: L-6200 type [manufactured by Hitachi High-Technologies Corporation] Detector: L-3300 type RI [manufactured by Hitachi High-Technologies Corporation] Column oven: L-655A-52 [manufactured by Hitachi High-Technologies Corporation] Column: Guard column; TSK Guard column HHR-L + column; TSKgel G4000HHR + TSKgel G2000HHR (all manufactured by Tosoh Corporation, trade names) Column size: 6.0 x 40 mm (guard column), 7.8 x 300 mm (column) Eluent: tetrahydrofuran Sample concentration: 30 mg / 5 mL Injection volume: 20 μL Flow rate: 1.00 mL / min Measurement temperature: 40°C

[0090] Production Example 1 (Production of Aminomaleimide Resin) 100 parts by mass of 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, 13.5 parts by mass of 3,3'-diethyl-4,4'-diaminodiphenylmethane (manufactured by Nippon Kayaku Co., Ltd., trade name: KAYAHARD (registered trademark) A-A), and 171 parts by mass of propylene glycol monomethyl ether were charged into a 5-liter reaction vessel capable of heating and cooling, equipped with a thermometer, a stirrer, and a water content meter equipped with a reflux condenser, and the mixture was allowed to react under reflux for 2 hours. The mixture was concentrated at the reflux temperature for 3 hours to produce an aminomaleimide resin-containing liquid with a solids concentration of 65% by mass. The weight-average molecular weight (Mw) of the resulting aminomaleimide resin was approximately 2,700.

[0091] Examples 1 to 4 and Comparative Examples 1 to 4 (Production of Resin Compositions) Each component shown in Table 1 was blended with methyl isobutyl ketone in the amounts shown in Table 1, and then the mixture was stirred and mixed at 25° C. or while heating to 50 to 80° C. to prepare a resin composition having a solids concentration of approximately 50% by mass. In Table 1, the unit of the blending amount of each component is parts by mass, and in the case of a solution, it means parts by mass converted into solids content.

[0092] (Production of resin-coated metal foil) The resin composition obtained in each example was applied to one side of an 18 μm thick low-profile copper foil (manufactured by Mitsui Mining & Smelting Co., Ltd., product name "3EC-VLP-18") so that the thickness of the resin layer after drying would be 30 μm. The resin composition was applied to the roughened surface of the low-profile copper foil. The resin composition was then heated and dried at 105°C for 5 minutes to bring the resin composition into a B-stage state, and a resin-coated metal foil was produced.

[0093] (Production of double-sided copper foil-covered resin plate) The resin-covered metal foil obtained above was cut into two pieces measuring 250 mm long x 250 mm wide. The two resin-covered metal foils were then stacked with the resin layers facing each other, and then heated and pressurized at a temperature of 230°C, a pressure of 2.0 MPa, and a time of 60 minutes to harden the resin layers, thereby producing a double-sided copper foil-covered resin plate.

[0094] [Evaluation Method] Each evaluation was carried out according to the following methods. The results are shown in Table 1.

[0095] (Method for Measuring Thermal Expansion Coefficient) The resin plates with copper foil on both sides obtained in each example were immersed in a 10% by mass solution of ammonium persulfate (manufactured by Mitsubishi Gas Chemical Company, Inc.), a copper etching solution, to remove the copper foil. The resulting resin plates were cut into pieces 0.4 mm wide and 20 mm long and dried at 105°C for 1 hour to prepare test specimens. The test specimens were clamped at both ends along their long sides with upper and lower gripping tools, with a 10 mm gap between the gripping tools. Next, dimensional changes were measured using a thermomechanical analyzer (TMA) (manufactured by Seiko Instruments Inc., product name "SS6100") in tensile mode at a temperature range of 30 to 300°C, a heating rate of 5°C / min, and a load of 4 g. The average dimensional change per unit temperature from 30 to 100°C was taken as the thermal expansion coefficient.

[0096] (Method for evaluating cracks on the surface of the resin layer) The resin-coated metal foil obtained in each example was bent 90° around a stainless steel round rod with a diameter of 50 mm. At this time, the resin-coated metal foil was bent in a state where the metal foil was in contact with the round rod. Thereafter, the surface of the resin layer was visually observed to check the presence and number of cracks, and evaluated based on the following criteria: A: No cracks B: Number of cracks: 1 / 100 mm ２ Above, 5 pieces / 100 mm ２ C: Number of cracks: 6 / 100mm ２ Above, 20 pieces / 100 mm ２ below

[0097] (Method for evaluating interlayer insulation) The resin-coated metal foil obtained in each example was placed on one copper foil of a double-sided copper-clad laminate (manufactured by Resonac Corporation, product name "MCL-E-705G", thickness of laminate excluding copper foil: 0.4 mm) with the resin layer facing the double-sided copper-clad laminate, and heated and pressurized for 100 minutes at a temperature of 230 ° C. and a pressure of 3.0 MPa to produce a substrate having, in this order, an insulating layer (cured product of the resin layer) and copper foil derived from the resin-coated metal foil on one copper foil of the double-sided copper-clad laminate. Next, the copper foil derived from the resin-coated metal foil and the insulating layer (cured product of the resin layer) were removed from a portion of the surface of the substrate to expose the copper foil of the double-sided copper-clad laminate. Next, the positive terminal of a power supply was connected to the copper foil derived from the resin-coated metal foil on the substrate, and the negative terminal of the power supply was connected to the copper foil of the exposed double-sided copper-clad laminate, and a voltage of 5 V was applied. Under temperature and humidity conditions of 130°C and 85% RH, the moisture absorption insulation resistance between the electrical wiring was measured with an insulation resistance meter (ion migration tester, manufactured by IMV Corporation, product name: MIG-8600B). The moisture absorption insulation resistance value was 10 ７ The time until the resistance reached Ω or less was measured and evaluated according to the following criteria: A: 200 hours or more B: 10 hours or more but less than 200 hours C: Less than 10 hours

[0098]

[0099] The details of each component listed in Table 1 are as follows: [Component (A)] Epoxy resin having an aliphatic ring: tricyclo[5.2.1.0 ２，６] decanedimethanol diglycidyl ether, a compound represented by the following general formula (A-3), epoxy equivalent: 170 g / eq, liquid at 25°C, viscosity at 25°C: 230 mPa·s

[0100]

[0101] [Comparative Components] Bisphenol A type epoxy resin: epoxy equivalent: 180 g / eq, liquid at 25°C Dicyclopentadiene novolac type epoxy resin: epoxy resin represented by the following general formula (1), epoxy equivalent: 250 g / eq, solid at 25°C

[0102] (wherein n is a number of 1 or more) Propylene oxide-modified bisphenol A-type epoxy resin 1: an epoxy resin represented by the following general formula (2), epoxy equivalent: 310 g / eq, liquid at 25°C

[0103] (In the formula, n １ and n ２ is a number of 1 or more.) Propylene oxide-modified bisphenol A-type epoxy resin 2: an epoxy resin represented by the above general formula (2), epoxy equivalent: 470 g / eq, liquid at 25°C

[0104] [Component (B)] Maleimide resin: aminomaleimide resin produced in Production Example 1

[0105] [Component (C)] Inorganic filler: amorphous silica (spherical, average particle size: 0.5 μm)

[0106] [Component (D)] Acrylic polymer: acrylic polymer containing epoxy groups, weight average molecular weight (Mw) 850,000, epoxy equivalent: 4,800 g / eq

[0107] [Component (E)] Curing accelerator: addition reaction product of p-benzoquinone and tri-n-butylphosphine

[0108] From the results shown in Table 1, it can be seen that the resin-coated metal foils manufactured using the resin compositions of Examples 1 to 4 of this embodiment suppress the occurrence of cracks in the resin layer and have excellent interlayer insulation properties for the insulating layer formed from the resin layer.

Claims

1. A resin composition used for forming a resin layer of a metal foil with resin, which has a metal foil and a resin layer laminated on one surface of the metal foil, the resin composition containing (A) an epoxy resin having an aliphatic ring and an epoxy equivalent of 240 g / eq or less.

2. The resin composition according to claim 1, wherein the aliphatic ring is a condensed ring.

3. The condensed ring is tricyclo[5.2.1.0 ２，６ decane ring, and the resin composition according to claim 2.

4. The resin composition according to claim 1, wherein the component (A) is a bifunctional epoxy resin.

5. The resin composition according to claim 1, wherein the component (A) is an epoxy resin having no novolak structure.

6. The resin composition according to claim 1, further containing (B) a maleimide resin.

7. The resin composition according to claim 1, further containing (C) an inorganic filler.

8. A metal foil with resin, which has a metal foil and a resin layer laminated on one surface of the metal foil, and the resin layer contains the resin composition according to any one of claims 1 to 7 or a semi-cured product thereof.

9. The metal foil with resin according to claim 8, wherein the metal foil is a copper foil.

10. A laminate having a cured product of the resin composition according to any one of claims 1 to 7 and a metal foil.

11. A printed wiring board having a cured product of the resin composition according to any one of claims 1 to 7.

12. A semiconductor package having the printed wiring board according to claim 11 and a semiconductor element.

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