TWI894133B - Composite material and manufacturing method thereof, prepreg, laminate, printed circuit board and semiconductor package - Google Patents

Abstract

A method for producing a composite material, a composite material obtained by the production method, a laminate using the composite material and a method for producing the same, a printed wiring board, and a semiconductor package, and a prepreg used in the composite material production method. The composite material production method includes the step of heating the prepreg to a temperature of 200°C or higher. The prepreg contains glass cloth and a thermosetting resin composition. The glass cloth has an average diameter ratio of weft to warp yarns, i.e., weft/warp yarns, exceeding 1.00, and a warp to weft yarn weave density ratio, i.e., warp/weft yarns, exceeding 1.00.

Description

Composite material and manufacturing method thereof, prepreg, laminate, printed circuit board and semiconductor package

The present invention relates to a composite material and a manufacturing method thereof, a prepreg, a laminate, a printed circuit board, and a semiconductor package.

In recent years, the miniaturization, lightweighting, and multifunctionalization of electronic devices have been further advanced. Along with this, the high integration of large integrated circuits (LSIs) and chip components has also progressed, and their forms are rapidly changing toward multi-pin and miniaturization. Therefore, in order to increase the packaging density of electronic components, the development of multi-layer printed circuit boards with fine wiring is progressing. As a manufacturing method for multi-layer printed circuit boards that meets these requirements, multi-layer printed circuit boards using an additive manufacturing method are gradually becoming mainstream as a method suitable for lightweighting, miniaturization, and fine wiring. This additive manufacturing method uses prepregs or the like as insulating layers and forms wiring layers by connecting only the required parts on one side. The required parts are, for example, through holes formed by laser irradiation (hereinafter also referred to as "laser vias").

Multilayer printed wiring boards (PCBs) focus on high electrical connection reliability and excellent high-frequency characteristics between multiple layers of circuit patterns formed with fine wiring pitches. Furthermore, they are required to have highly reliable connections with semiconductor chips. In particular, recent progress in thinning and increasing wiring density has led to a significant trend toward smaller diameters of the laser vias used to provide these interlayer connections. When using small-diameter laser vias for interlayer connections, one of the most important characteristics is the dimensional stability of the substrate. Multilayer wiring imposes multiple thermal histories and stresses on each substrate during stacking. Therefore, if the substrate's dimensions fluctuate significantly, especially if the dimensional variation between substrates is large due to thermal history, the laser vias will shift position with each buildup, potentially leading to problems such as reduced connection reliability. Therefore, substrates with less dimensional variation are being sought.

For example, Patent Document 1 discloses a prepreg for improving interlayer uniformity in a multi-layer printed wiring board. The prepreg is characterized by comprising: a core comprising a substrate comprising a pre-cured thermosetting resin and having a first surface and a second surface; and first and second adhesive layers formed on the first and second surfaces of the core, respectively. [Prior Art Document] (Patent Document)

Patent Document 1: Japanese Patent Application Publication No. 2002-103494

[Problem to be Solved by the Invention] However, the prepreg of Patent Document 1 contains a pre-cured thermosetting resin as its core, resulting in problems such as poor wiring embedding. Furthermore, the prepreg of Patent Document 1 requires multiple layers with varying degrees of curing, necessitating complex production steps. Consequently, there is a desire for a prepreg that can be produced more simply and exhibits minimal dimensional variation.

Therefore, an object of the present invention is to provide a composite material and a method for manufacturing the composite material, a laminate using the composite material and a method for manufacturing the laminate, a printed wiring board and a semiconductor package, and a prepreg used in the composite material manufacturing method, wherein the composite material exhibits minimal dimensional variation. [Solution]

The inventors of the present invention have devoted themselves to research to solve the above-mentioned problems and have found that the above-mentioned problems can be solved by the following invention, thereby completing the present invention. The present invention is related to the following technologies [1] to [13]. [1] A method for manufacturing a composite material, which has the step of heating a prepreg to above 200°C, wherein the prepreg contains glass cloth and a thermosetting resin composition, and the average fiber diameter ratio of the weft yarn to the warp yarn constituting the aforementioned glass cloth, i.e., weft yarn/warp yarn, is greater than 1.00, and the weaving density ratio of the warp yarn to the weft yarn, i.e., warp yarn/weft yarn, is greater than 1.00. [2] The method for producing a composite material as described in [1] above, wherein the thermosetting resin composition contains: (A) a maleimide compound having an N-substituted maleimide group; (B) an epoxy resin; and (C) a copolymer resin having structural units derived from an aromatic vinyl compound and structural units derived from maleic anhydride. [3] The method for producing a composite material as described in [2] above, wherein the thermosetting resin composition further contains: (D) silicon oxide treated with an aminosilane coupling agent. [4] The method for producing a composite material as described in any one of [1] to [3] above, wherein the average fiber diameter ratio, i.e., weft/warp, is 1.02 to 1.30. [5] The method for producing a composite material as described in any one of [1] to [4] above, wherein the weaving density ratio, i.e., warp/weft, is 1.10 to 1.50. [6] The method for producing a composite material as described in any one of [1] to [5] above, wherein the thickness of the glass cloth is 5 to 50 μm. [7] The method for producing a composite material as described in any one of [1] to [6] above, wherein the basis weight of the glass cloth is 12 to 35 g/m ² . [8] A method for manufacturing a laminate, wherein the laminate is a laminate having two or more insulating layers, or a laminate having one or more insulating layers and one or more metal foil layers, wherein the insulating layer is a composite material, and the composite material is formed by the method for manufacturing a composite material described in any one of [1] to [7]. [9] A composite material manufactured by the method for manufacturing a composite material described in any one of [1] to [7]. [10] A laminate containing the composite material described in [9]. [11] A printed circuit board formed using the laminate described in [10]. [12] A semiconductor package comprising a semiconductor element mounted on the printed circuit board described in [11]. [13] A prepreg comprising glass cloth and a thermosetting resin composition, wherein the glass cloth has an average diameter ratio of weft to warp, i.e., weft/warp, exceeding 1.00, and a weave density ratio of warp to weft, i.e., warp/weft, exceeding 1.00, and the thermosetting resin composition comprises: (A) a maleimide compound having an N-substituted maleimide group; (B) an epoxy resin having at least two epoxy groups per molecule; and (C) a copolymer resin having structural units derived from an aromatic vinyl compound and structural units derived from maleic anhydride. [Effects]

The present invention provides a composite material and a method for manufacturing the composite material, a laminate using the composite material and a method for manufacturing the laminate, a printed wiring board and a semiconductor package, and a prepreg used in the method for manufacturing the composite material, wherein the composite material has a small dimensional variation.

In the numerical ranges described in this specification, the upper or lower limits of the numerical ranges may be replaced with the values disclosed in the Examples. Furthermore, the lower and upper limits of a numerical range may be arbitrarily combined with the lower and upper limits of other numerical ranges, respectively. In addition, unless otherwise specified, each component and material exemplified in this specification may be used alone or in combination of two or more. In this specification, when a composition contains multiple substances corresponding to each component, the content of each component in the composition, unless otherwise specified, refers to the total amount of the multiple substances present in the composition. Aspects in which the items described in this specification are arbitrarily combined are also encompassed by the present invention.

[Composite Material and Manufacturing Method Thereof] The composite material manufacturing method of this embodiment comprises heating a prepreg to a temperature of 200°C or higher. The prepreg comprises a glass cloth and a thermosetting resin composition. Additionally, the glass cloth has an average weft-to-warp ratio (weft/warp) exceeding 1.00, and a warp-to-weft weave density ratio (warp/weft) exceeding 1.00. Hereinafter, the glass cloth used in the manufacturing method of this embodiment will be referred to as "glass cloth (g)" and the prepreg will be referred to as "prepreg (p)" to distinguish it from other materials.

The production method of this embodiment produces a composite material with minimal dimensional variation. The reason for this is unclear, but it is presumed to be as follows. The glass cloth (g) used in the production method of this embodiment has the following characteristics: an average weft-to-warp yarn diameter ratio (weft/warp) exceeding 1.00, and a warp-to-weft yarn weave density ratio (warp/weft) exceeding 1.00. This allows for enhanced strength in the weft direction while maintaining a moderate thickness. We speculate that this suppresses the stress generated by tension applied to the warp direction during glass cloth production, thereby uniformizing the dimensional change during the composite material production process. Furthermore, the degree of dimensional change uniformity tends to be significantly improved by combining glass cloth (g) with a thermosetting resin composition and performing high-temperature curing at temperatures above 200°C. Furthermore, in this embodiment, the degree of dimensional change uniformity achieved by high-temperature curing is even higher than when using glass cloths other than glass cloth (g). While it is believed that thermosetting resins tend to reduce dimensional change by producing uniform hardening and shrinkage during high-temperature curing, glass cloth, which contains inherently uneven stress, undergoes dimensional change unevenly when heated to high temperatures in order to release this stress. Therefore, it is believed that when conventional glass cloth is used, even when high-temperature curing is performed, the uniform hardening and shrinkage of the thermosetting resin and the uneven shrinkage of the glass cloth compete with each other, preventing uniform dimensional change. On the other hand, we speculate that the glass cloth (g) used in the manufacturing method of this embodiment suppresses uneven stress generation, effectively exhibiting uniform shrinkage caused by the thermosetting resin during high-temperature curing, resulting in significantly more uniform dimensional change. Below, we first explain the various components used in the composite material manufacturing method of this embodiment, followed by an explanation of suitable manufacturing conditions.

>Prepreg (p)> The prepreg (p) used in the manufacturing method of this embodiment contains glass cloth (g) and a thermosetting resin composition.

(Glass Cloth (g)) In the glass cloth (g), the average yarn diameter ratio of the weft yarns to the warp yarns (weft/warp) exceeds 1.00, and the weave density ratio of the warp yarns to the weft yarns (warp/weft) exceeds 1.00. In this embodiment, the physical properties of the glass cloth, such as the average yarn diameter of the warp and weft yarns, the weave density, and the thickness of the glass cloth described below, can be measured in accordance with JIS R 3240.

[Average Diameter Ratio (Weft/Warp)] To minimize dimensional variation, the average diameter ratio of weft to warp in glass cloth (g) should be greater than 1.00, preferably 1.02 to 1.30, more preferably 1.05 to 1.20, and even more preferably 1.10 to 1.15.

[Average Wire Diameter] To maintain good strength while reducing the thickness of the glass cloth, the average wire diameter of the warps in the glass cloth (g) is preferably 2.0 to 10 μm, more preferably 3.0 to 8.0 μm, even more preferably 3.5 to 6.0 μm, and particularly preferably 4.0 to 5.0 μm, while fully satisfying the above-mentioned average wire diameter ratio (weft/warp). From the viewpoint of reducing the thickness of the glass cloth while maintaining good strength, the average wire diameter of the weft yarn in the glass cloth (g) is preferably 2.0 to 10 μm, more preferably 3.0 to 8.0 μm, more preferably 4.0 to 6.0 μm, and particularly preferably 4.5 to 5.5 μm, while fully satisfying the above-mentioned average wire diameter ratio (weft yarn/warp yarn).

[Thread Count] To maintain good strength while reducing the thickness of the glass cloth, the thread count per warp and weft yarn of the glass cloth (g) is preferably 40-400, more preferably 50-300, even more preferably 60-200, and particularly preferably 80-150.

[Weave Density Ratio (Warp/Weft)] To minimize dimensional variation, the warp-to-weft weave density ratio (warp/weft) of the glass cloth (g) should be greater than 1.00, preferably 1.10-1.50, more preferably 1.20-1.35, and even more preferably 1.25-1.30.

[Weave Density] To maintain good strength while reducing the thickness of the glass cloth, the warp weave density of the glass cloth (g) is preferably 40-100 count/25 mm, more preferably 50-90 count/25 mm, even more preferably 60-85 count/25 mm, and particularly preferably 70-80 count/25 mm, while fully satisfying the aforementioned weave density ratio (warp/weft). From the perspective of reducing the thickness of the glass cloth while maintaining good strength, the weft yarn weave density of the glass cloth (g) is preferably 40 to 90 counts/25 mm, more preferably 45 to 80 counts/25 mm, more preferably 50 to 70 counts/25 mm, and particularly preferably 55 to 65 counts/25 mm, while fully satisfying the above-mentioned weave density ratio (warp yarn/weft yarn).

[Glass Cloth (g) Thickness] To maintain good strength while reducing the thickness of the glass cloth, the thickness of the glass cloth (g) is preferably 3-80 μm, more preferably 5-50 μm, more preferably 10-40 μm, particularly preferably 15-30 μm, and most preferably 20-28 μm.

[Basic Weight] From the perspective of maintaining the strength of the glass cloth while reducing its thickness, the basic weight of the glass cloth (g) is preferably 5-50 g/ ^m2 , more preferably 12-35 g/ ^m2 , more preferably 16-32 g/ ^m2 , particularly preferably 20-30 g/ ^m2 , and most preferably 22-28 g/ ^m2 .

From the perspectives of minimizing dimensional variation, heat resistance, moisture resistance, and processability, glass cloth is preferably surface-treated with a silane coupling agent or mechanically opened. The type of yarn (single fiber) that constitutes glass cloth is not particularly limited, and examples include E-glass, S-glass, C-glass, D-glass, T-glass, NE-glass, A-glass, H-glass, and quartz glass.

(Thermosetting Resin Composition) The thermosetting resin composition contained in the prepreg (p) used in the production method of this embodiment is not particularly limited and can be appropriately selected from among conventional insulating resin materials depending on the desired properties. The thermosetting resin composition is not particularly limited as long as it contains a thermosetting resin. Examples of thermosetting resins include maleimide compounds, epoxy resins, phenol resins, cyanate resins, isocyanate resins, benzoxazine resins, oxetane resins, amino resins, unsaturated polyester resins, allyl resins, dicyclopentadiene resins, silicone resins, triazine resins, and melamine resins. These resins may be used alone or in combination. Among these, maleimide compounds and epoxy resins are preferred from the viewpoints of heat resistance, formability, and electrical insulation.

From the perspective of achieving excellent copper foil adhesion, low thermal expansion, and dielectric properties, the thermosetting resin composition preferably contains (A) a maleimide compound having an N-substituted maleimide group; more preferably, it further contains one or more selected from the group consisting of: (B) an epoxy resin; (C) a copolymer resin having structural units derived from a substituted vinyl compound and structural units derived from maleic anhydride; (D) an inorganic filler; (E) a hardener; (F) a thermoplastic elastomer; and (G) a hardening accelerator. Preferred aspects of each component are described in detail below.

[(A) Maleimide Compound] (A) The maleimide compound is preferably a maleimide compound (a1) having at least two N-substituted maleimide groups (hereinafter also referred to as "maleimide compound (a1)"). Examples of the maleimide compound (a1) include a maleimide compound having an aliphatic alkyl group (without an aromatic alkyl group) between any two of a plurality of maleimide groups (hereinafter also referred to as an "aliphatic alkyl-containing maleimide") and a maleimide compound having an aromatic alkyl group between any two of a plurality of maleimide groups (hereinafter also referred to as an "aromatic alkyl-containing maleimide"). Among these, aromatic alkyl-containing maleimides are preferred from the perspectives of high heat resistance, low relative dielectric constant, and high copper foil adhesion. From the same perspective, the maleimide compound (a1) is preferably a maleimide compound having two to five N-substituted maleimide groups per molecule, more preferably a maleimide compound having two N-substituted maleimide groups per molecule, more preferably an aromatic alkyl group-containing maleimide represented by any of the following general formulas (a1-1) to (a1-4), and particularly preferably an aromatic alkyl group-containing maleimide represented by the following general formula (a1-2). (A) The maleimide compound may be used alone or in combination of two or more.

In the above formulas (a1-1) to (a1-4), ^RA1 to ^RA3 each independently represent an aliphatic alkyl group having 1 to 5 carbon atoms; ^XA1 represents an alkylene group having 1 to 5 carbon atoms, an alkylene group having 2 to 5 carbon atoms, -O-, -C(=O)-, -S-, -S-S-, or a sulfonyl group; p, q, and r each independently represent an integer from 0 to 4; and s represents an integer from 0 to 10. Examples of the aliphatic alkyl group having 1 to 5 carbon atoms represented by ^RA1 to ^RA3 include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tertiary butyl, and n-pentyl. From the viewpoints of high heat resistance, low relative dielectric constant, and high copper foil adhesion, the aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and more preferably a methyl group or an ethyl group.

Examples of the alkylene group having 1 to 5 carbon atoms represented by X ^A1 include methylene, 1,2-dimethylene, 1,3-trimethylene, 1,4-tetramethylene, and 1,5-pentamethylene. From the perspectives of high heat resistance, low relative dielectric constant, and high copper foil adhesion, alkylene groups having 1 to 3 carbon atoms are preferred, with methylene being particularly preferred. Examples of the alkylene group having 2 to 5 carbon atoms represented by X ^A1 include ethylene, propylene, isopropylene, butylene, isobutylene, pentylene, and isopentylene. Among these, isopropylene is preferred from the perspectives of high heat resistance, low relative dielectric constant, and high copper foil adhesion. Among the above options, X ^A1 is preferably an alkylene group having 1 to 5 carbon atoms or an alkylene group having 2 to 5 carbon atoms. More preferably, it is as described above. p, q, and r are each independently an integer from 0 to 4. From the perspectives of high heat resistance, low relative dielectric constant, and high copper foil adhesion, any of them is preferably an integer from 0 to 2, preferably 0 or 1, and more preferably 0. s is an integer from 0 to 10. From the perspective of ease of availability, it is preferably an integer from 0 to 5, and more preferably an integer from 0 to 3.

Specific examples of the maleimide compound (a1) include: maleimides containing an aliphatic alkyl group such as N,N'-ethylenebismaleimide, N,N'-hexamethylenebismaleimide, bis(4-maleimidocyclohexyl)methane, 1,4-bis(maleimidomethyl)cyclohexane; N,N'-(1,3-phenylene)bismaleimide, N,N'-[1,3-(2-methylphenylene)]bismaleimide, N,N'-[1,3-(4-methylphenylene)] Bismaleimide, N,N'-(1,4-phenylene)bismaleimide, bis(4-maleimidophenyl)methane, bis(3-methyl-4-maleimidophenyl)methane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide, bis(4-maleimidophenyl)ether, bis(4-maleimidophenyl)sulfide, bis(4-maleimidophenyl)sulfide, bis(4-maleimidophenyl)ketone, 1,4-bis(4-maleimidophenyl) aminophenyl)cyclohexane, 1,4-bis(maleimidomethyl)cyclohexane, 1,3-bis(4-maleimidophenoxy)benzene, 1,3-bis(3-maleimidophenoxy)benzene, bis[4-(3-maleimidophenoxy)phenyl]methane, bis[4-(4-maleimidophenoxy)phenyl]methane, 1,1-bis[4-(3-maleimidophenoxy)phenyl]ethane, 1,1-bis[4-(4-maleimidophenoxy)phenyl]ethane, 1,2- Bis[4-(3-maleimidophenoxy)phenyl]ethane, 1,2-bis[4-(4-maleimidophenoxy)phenyl]ethane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]propane, 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]butane, 2,2-bis[4-(4-maleimidophenoxy)phenyl]butane, 2,2-bis[4-(3-maleimidophenoxy)phenyl]butane Bis[4-(4-maleimidophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(4-maleimidophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 4,4'-bis(3-maleimidophenoxy)biphenyl, 4,4'-bis(4-maleimidophenoxy)biphenyl, bis[4-(3-maleimidophenoxy)phenyl]ketone, bis[4-(4-maleimidophenoxy)phenyl]ketone, bis(4-maleimidophenyl)disulfide Ether, bis[4-(3-maleimidophenoxy)phenyl] sulfide, bis[4-(4-maleimidophenoxy)phenyl] sulfide, bis[4-(3-maleimidophenoxy)phenyl] sulfide, bis[4-(4-maleimidophenoxy)phenyl] sulfide, bis[4-(3-maleimidophenoxy)phenyl] sulfide, bis[4-(4-maleimidophenoxy)phenyl] sulfide, bis[4-(3-maleimidophenoxy)phenyl] sulfide, bis[4-(4-maleimidophenoxy)phenyl] sulfide, bis[4-(3-maleimidophenoxy)phenyl] sulfide, bis[4-(4-maleimidophenoxy)phenyl] sulfide, bis[4-(3-maleimidophenoxy)phenyl] sulfide, bis[4-(4-maleimidophenoxy)phenyl] sulfide phenoxy)phenyl] ether, 1,4-bis[4-(4-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(3-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(3-maleimidophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(4-maleimidophenoxy)-3 Benzene, 1,3-bis[4-(4-maleiminophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(3-maleiminophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(3-maleiminophenoxy)-3,5-dimethyl-α,α-dimethylbenzyl]benzene, polyphenylmethane maleimide and other aromatic alkyl maleimides. Among these, bis(4-maleimidophenyl)methane, bis(4-maleimidophenyl)sulfone, bis(4-maleimidophenyl)sulfide, bis(4-maleimidophenyl)disulfide, N,N'-(1,3-phenylene)bismaleimide, and 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane are preferred from the viewpoint of high reactivity and ability to further improve heat resistance. From the viewpoint of low cost, bis(4-maleimidophenyl)methane and N,N'-(1,3-phenylene)bismaleimide are preferred.

The maleimide compound (A) is preferably a compound obtained by reacting the maleimide compound (a1) with one or more selected from the group consisting of a monoamine compound (a2) and a diamine compound (a3) (hereinafter also referred to as a "modified maleimide compound"). More preferably, it is a compound obtained by reacting the maleimide compound (a1), a monoamine compound (a2), and a diamine compound (a3); or a compound obtained by reacting the maleimide compound (a1) with a diamine compound (a3).

(Monoamine compound (a2)) The monoamine compound (a2) is not particularly limited as long as it is a compound having one amino group. From the viewpoint of high heat resistance, low relative dielectric constant, high copper foil adhesion, etc., a monoamine compound having an acidic substituent is preferred, and a monoamine compound represented by the following general formula (a2-1) is more preferred.

In the general formula (a2-1), ^RA4 represents an acidic substituent selected from a hydroxyl group, a carboxyl group, and a sulfonic acid group; ^RA5 represents an alkyl group having 1 to 5 carbon atoms or a halogen atom; t is an integer from 1 to 5, and u is an integer from 0 to 4, satisfying 1 ≤ t + u ≤ 5. When t is an integer from 2 to 5, multiple ^RA4s may be the same or different; and when u is an integer from 2 to 4, multiple ^RA5s may be the same or different. From the perspectives of solubility and reactivity, the acidic substituent represented by ^RA4 is preferably a hydroxyl group or a carboxyl group. Furthermore, considering heat resistance, a hydroxyl group is preferred. t is an integer from 1 to 5. From the perspectives of high heat resistance, low relative dielectric constant, and high copper foil adhesion, t is preferably an integer from 1 to 3, more preferably 1 or 2, and more preferably 1. Examples of the alkyl group having 1 to 5 carbon atoms represented by ^RA5 include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tertiary butyl, and n-pentyl. Preferred alkyl groups include alkyl groups having 1 to 3 carbon atoms. Examples of the halogen atom represented by ^RA5 include fluorine, chlorine, bromine, and iodine. u is an integer from 0 to 4. From the perspectives of high heat resistance, low relative dielectric constant, and high copper foil adhesion, u is preferably an integer from 0 to 3, more preferably 0 to 2, more preferably 0 or 1, and particularly preferably 0.

Examples of the monoamine compound (a2) include oxadiaminophenol, m-aminophenol, p-aminophenol, oxadiaminobenzoic acid, m-aminobenzoic acid, p-aminobenzoic acid, oxadiaminobenzenesulfonic acid, m-aminobenzenesulfonic acid, p-aminobenzenesulfonic acid, 3,5-dihydroxyaniline, and 3,5-dicarboxyaniline. Of these, oxadiaminophenol, m-aminophenol, and p-aminophenol are preferred from the perspective of heat resistance. Taking into account dielectric properties, low thermal expansion, and manufacturing costs, p-aminophenol is more preferred. The monoamine compound (a2) may be used alone or in combination of two or more.

(Diamine compound (a3)) There is no particular limitation on the diamine compound (a3) as long as it is a compound having two amino groups. From the viewpoint of high heat resistance, low relative dielectric constant, high copper foil adhesion, etc., the preferred ones are diamine compounds represented by the following general formula (a3-1) and modified siloxane compounds having amino groups at the molecular ends described later. In formula (a3-1), X ^A2 represents an aliphatic alkyl group having 1 to 3 carbon atoms or -O-; ^RA6 and ^RA7 each independently represent an alkyl group having 1 to 5 carbon atoms, a halogen atom, a hydroxyl group, a carboxyl group, or a sulfonic acid group; and v and w each independently represent an integer from 0 to 4.

Examples of the aliphatic alkyl group having 1 to 3 carbon atoms represented by X ^A2 include methylene, ethylene, propylene, and trimethylene. Preferred X ^A2 is methylene. Examples of the alkyl group having 1 to 5 carbon atoms represented by ^RA6 and ^RA7 include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and n-pentyl. Preferred alkyl groups are those having 1 to 3 carbon atoms. v and w are preferably integers from 0 to 2, preferably 0 or 1, and more preferably 0.

Examples of the modified siloxane compound having an amino group at a molecular terminal include diamine compounds represented by the following general formula (a3-2).

In the general formula (a3-2), R ^A8 to R ^A11 each independently represent an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a phenyl group having a substituent; R ^A12 and R ^A13 each independently represent a divalent organic group; and m is an integer of 2 to 100.

Examples of the alkyl group having 1 to 5 carbon atoms represented by R ^A8 to R ^A11 include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and n-pentyl. Preferred alkyl groups include alkyl groups having 1 to 3 carbon atoms, with methyl being more preferred. Examples of substituents in the phenyl group having a substituent include alkyl groups having 1 to 5 carbon atoms, alkenyl groups having 2 to 5 carbon atoms, and alkynyl groups having 2 to 5 carbon atoms. Examples of the alkyl group having 1 to 5 carbon atoms include the same groups as described above. Examples of the alkenyl group having 2 to 5 carbon atoms include vinyl and allyl. Examples of the alkynyl group having 2 to 5 carbon atoms include ethynyl and propargyl. Examples of the divalent organic group represented by R ^A12 and R ^A13 include alkylene, alkenylene, alkynylene, arylene, -O-, or a divalent linking group composed of a combination thereof. Examples of the alkylene include alkylene groups having 1 to 10 carbon atoms, such as methylene, ethylene, and propylene. Examples of the alkenylene include alkenylene groups having 2 to 10 carbon atoms. Examples of the alkynylene include alkynylene groups having 2 to 10 carbon atoms. Examples of the arylene group include arylene groups having 6 to 20 carbon atoms, such as phenylene and naphthylene. Among these, alkylene and arylene are preferred as R ^A12 and R ^A13 . m is preferably an integer from 2 to 50, more preferably from 3 to 40, and even more preferably from 5 to 30.

Specific examples of the diamine compound (a3) include 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenylpropane, 2,2'-bis(4,4'-diaminodiphenyl)propane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylethane, 3,3'-diethyl-4,4'-diaminodiphenylethane, 4,4'-diaminodiphenylethane, ether, 4,4'-diaminodiphenyl sulfide, 3,3'-dihydroxy-4,4'-diaminodiphenylmethane, 2,2',6,6'-tetramethyl-4,4'-diaminodiphenylmethane, 3,3'-dichloro-4,4'-diaminodiphenylmethane, 3,3'-dibromo-4,4'-diaminodiphenylmethane, 2,2',6,6'-tetrachloro-4,4'-diaminodiphenylmethane, 2,2',6,6'-tetrabromo-4,4'-diaminodiphenylmethane, and modified siloxane compounds having amino groups at the molecular ends of the above. Among these, 4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, and modified siloxane compounds having amino groups at their molecular terminals are preferred due to their low cost. The diamine compound (a3) may be used alone or in combination of two or more.

The reaction of the maleimide compound (a1) with one or more selected from the group consisting of a monoamine compound (a2) and a diamine compound (a3) is preferably carried out in the presence of an organic solvent at a reaction temperature of 70 to 200°C for 0.1 to 10 hours. The reaction temperature is preferably 70 to 160°C, more preferably 70 to 130°C, and particularly preferably 80 to 120°C. The reaction time is preferably 1 to 8 hours, more preferably 2 to 6 hours.

In the reaction of component (a1) with one selected from the group consisting of components (a2) and (a3) during the production of the modified maleimide compound, the amounts of the three components used are preferably such that the relationship between the sum of the _-NH2 group equivalents (primary amine group equivalents) possessed by one or more selected from the group consisting of components (a2) and (a3) and the maleimide group equivalent of component (a1) satisfies the following formula. 0.1 ≤ [Maleimide Group Equivalent] / [Sum of _-NH2 Group Equivalents] ≤ 10. Setting the ratio [Maleimide Group Equivalent] / [Sum of _-NH2 Group Equivalents] to 0.1 or greater suppresses gelation and a decrease in heat resistance. Furthermore, setting the ratio [Maleimide Group Equivalent] / [Sum of _-NH2 Group Equivalents] to 10 or less improves solubility in organic solvents, adhesion to copper foil, and heat resistance. From the same perspective, the following formula is more preferably satisfied: 1 ≤ [Maleimide Group Equivalent] / [Sum of _-NH2 Group Equivalents] ≤ 9. The following formula is even more preferably satisfied. 2≦[maleimide group equivalent]/[total of _-NH2 group equivalents]≦8 Furthermore, when the modified maleimide compound is a compound obtained by reacting component (a1), component (a2) and component (a3), the ratio of the structural unit derived from component (a2) to the structural unit derived from component (a3), i.e., component (a3)/component (a2) (molar ratio), is preferably 0.9 to 5.0, more preferably 1.0 to 4.5, and even more preferably 1.0 to 4.0.

The weight average molecular weight (Mw) of the modified maleimide compound is preferably 400 to 3,500, more preferably 600 to 2,000, and even more preferably 800 to 1,500. In this specification, the weight average molecular weight is a value measured by gel permeation chromatography (GPC) using tetrahydrofuran as the eluent (based on standard polystyrene), more specifically, a value measured by the method described in the Examples.

[(B) Epoxy Resin] Examples of the epoxy resin (B) include glycidyl ether epoxy resins, glycidyl amine epoxy resins, and glycidyl ester epoxy resins. Among these, glycidyl ether epoxy resins are preferred. (B) Epoxy resins can also be classified into various types of epoxy resins according to their main skeletons. The above-mentioned epoxy resins can be further classified into: bisphenol-type epoxy resins such as bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin; biphenyl aralkyl novolac epoxy resin, phenol novolac epoxy resin, alkylphenol novolac epoxy resin, cresol novolac epoxy resin, naphthol alkylphenol copolymer novolac epoxy resin. Novolac-type epoxy resins, naphthol aralkyl cresol copolymer novolac-type epoxy resins, bisphenol A novolac-type epoxy resins, bisphenol F novolac-type epoxy resins, etc.; styrene-type epoxy resins; epoxy resins containing triazine skeletons; epoxy resins containing fluorene skeletons; naphthalene-type epoxy resins; anthracene-type epoxy resins; triphenylmethane-type epoxy resins; biphenyl-type epoxy resins; xylene-type epoxy resins; dicyclopentadiene-type epoxy resins, etc. (B) Epoxy resins may be used alone or in combination of two or more.

(B) The epoxy resin preferably has an epoxy equivalent weight of 100 to 500 g/eq, more preferably 120 to 400 g/eq, more preferably 140 to 300 g/eq, and particularly preferably 170 to 240 g/eq. Herein, the epoxy equivalent weight 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). Specifically, it can be determined by the following method: using a GT-200 automatic titrator manufactured by Mitsubishi Chemical Analytech Co., Ltd., 2 g of epoxy resin is weighed into a 200 mL beaker, 90 mL of methyl ethyl ketone is added dropwise, and the mixture is dissolved using an ultrasonic cleaner. 10 mL of glacial acetic acid and 1.5 g of cetyltrimethylammonium bromide are then added, and titrated with a 0.1 mol/L (mole/liter) perchloric acid/acetic acid solution.

[(C) Copolymer Resin] Component (C) is a copolymer resin (hereinafter referred to as "(C) copolymer resin") having structural units derived from a substituted vinyl compound and structural units derived from maleic anhydride. Examples of substituted vinyl compounds include aromatic vinyl compounds, aliphatic vinyl compounds, and vinyl compounds substituted with functional groups. Examples of aromatic vinyl compounds include styrene, 1-methylstyrene, vinyltoluene, and dimethylstyrene. Examples of aliphatic vinyl compounds include propylene, butadiene, and isobutylene. Examples of functionally substituted vinyl compounds include acrylonitrile and compounds having (meth)acryloyl groups, such as methyl acrylate and methyl methacrylate. Among these, aromatic vinyl compounds are preferred, with styrene being particularly preferred. Component (C) is preferably a copolymer resin comprising: a structural unit represented by the following general formula (C-i) as a structural unit derived from a substituted vinyl compound; and a structural unit represented by the following general formula (C-ii) as a structural unit derived from maleic anhydride. Component (C) may be used alone or in combination of two or more.

In formula (Ci), ^RC1 is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, ^RC2 is an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, an aryl group having 6 to 20 carbon atoms, a hydroxyl group, or a (meth)acryloyl group; x is an integer from 0 to 3; when x is 2 or 3, multiple ^RC2 groups may be the same or different.

Examples of the alkyl group having 1 to 5 carbon atoms represented by R ^C1 and R ^C2 include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, and n-pentyl. Preferred alkyl groups include alkyl groups having 1 to 3 carbon atoms. Examples of the alkenyl group having 2 to 5 carbon atoms represented by R ^C2 include allyl and crotyl. Preferred alkenyl groups include alkenyl groups having 3 or 4 carbon atoms. Examples of the aryl group having 6 to 20 carbon atoms represented by R ^C2 include phenyl, naphthyl, anthracenyl, and biphenyl. Preferred aryl groups include aryl groups having 6 to 10 carbon atoms. x is preferably 0 or 1, with 0 being more preferred.

In the copolymer resin (C), the content ratio of the structural units derived from the substituted vinyl compound to the structural units derived from maleic anhydride [structural units derived from the substituted vinyl compound/structural units derived from maleic anhydride] (molar ratio) is preferably 1 to 9, more preferably 2 to 9, and even more preferably 3 to 8. When the molar ratio is above the lower limit, the dielectric properties tend to be more effectively improved, while when the molar ratio is below the upper limit, the compatibility tends to be good. In the copolymer resin (C), the combined content of the structural units derived from the substituted vinyl compound and the structural units derived from maleic anhydride is preferably 50% by mass or more, more preferably 70% by mass or more, more preferably 90% by mass or more, and particularly preferably substantially 100% by mass. The weight average molecular weight (Mw) of the copolymer resin (C) is preferably 4,500 to 18,000, more preferably 6,000 to 17,000, more preferably 8,000 to 16,000, and particularly preferably 8,000 to 15,000.

[(D) Inorganic Filler] The thermosetting resin composition may further contain (D) an inorganic filler. Examples of (D) inorganic fillers include silicon oxide, aluminum oxide, titanium oxide, mica, ceria, barium titanium oxide, potassium titanium oxide, strontium titanium oxide, calcium titanium oxide, aluminum carbonate, magnesium hydroxide, aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, clays such as calcined clay, talc, aluminum borate, silicon carbide, quartz powder, short glass fibers, fine glass powder, and insulating glass. Preferred examples of glass include E-glass, T-glass, and D-glass. (D) Inorganic fillers can be used singly or in combination. Silicon oxide is preferred among these materials from the perspectives of dielectric properties, heat resistance, and low thermal expansion. Examples of silicon oxide include deposited silicon oxide, which is produced by a wet process and has a high water content, and dry-process silicon oxide, which is produced by a dry process and contains almost no bond water. Dry-process silicon oxide can be further categorized by production method into pulverized silicon oxide, fumed silicon oxide, and fused spherical silicon oxide. Among these, fused spherical silicon oxide is preferred from the perspectives of low thermal expansion and high fluidity when filled in resin.

(D) The average particle size of the inorganic filler is preferably 0.1 to 10 μm, more preferably 0.3 to 8 μm, and even more preferably 0.5 to 2 μm. An average particle size of 0.1 μm or greater maintains good fluidity when highly filled in the resin. An average particle size of 10 μm or less reduces the likelihood of coarse particles being mixed in, thereby suppressing problems caused by coarse particles. The average particle size herein refers to the particle size at the point corresponding to 50% of the volume when the cumulative particle size distribution curve is calculated using the particle size, with the total volume of the particles being 100%. This can be measured using a particle size distribution measuring device using a laser diffraction scattering method, for example.

Using silica treated with an aminosilane-based coupling agent as the inorganic filler (D) can improve low thermal expansion properties. Furthermore, by improving adhesion with the aforementioned components (A) to (C), silica shedding can be suppressed. This also suppresses deformation of the laser via shape caused by excessive desmear, making it preferable.

Aminosilane coupling agents may have one, two, or three or more amine groups, but typically have one or two. Examples of aminosilane coupling agents with one amine group include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylene)propylamine, and 2-propynyl [3-(trimethoxysilyl)propyl]carbamate. Examples of aminosilane coupling agents with two amino groups include N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 1-[3-(trimethoxysilyl)propyl]urea, and 1-[3-(triethoxysilyl)propyl]urea. Aminosilane coupling agents can be used alone or in combination.

[(E) Hardener] Thermosetting resin compositions may further contain a (E) hardener. Examples of the (E) hardener include: dicyandiamide; chain aliphatic amines other than dicyandiamide, such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, hexamethylenediamine, diethylaminopropylamine, tetramethylguanidine, and triethanolamine; cyclic aliphatic amines such as isophoronediamine, diaminodicyclohexylmethane, bis(aminomethyl)cyclohexane, bis(4-amino-3-methyldicyclohexyl)methane, N-aminoethylpiperazine, and 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxahistoro[5.5]undecane; and aromatic amines such as xylylenediamine, phenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfonium. (E) One hardener may be used alone or in combination of two or more.

[(F) Thermoplastic Elastomer] The thermosetting resin composition may further contain a (F) thermoplastic elastomer. Examples of the (F) thermoplastic elastomer include styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic-based elastomers, silicone-based elastomers, and derivatives thereof. Among these, styrene-based elastomers are preferred. The (F) thermoplastic elastomer may be used alone or in combination of two or more. In this embodiment, the definition of the (F) thermoplastic elastomer does not include the aforementioned (C) component.

(F) The thermoplastic elastomer preferably has reactive functional groups at the molecular ends or within the molecular chain. Examples of such reactive functional groups include epoxy, hydroxy, carboxyl, amine, amide, isocyanate, acryl, methacryl, and vinyl groups. Having such reactive functional groups at the molecular ends or within the molecular chain improves compatibility and the heat resistance of the substrate. From the perspective of adhesion to metal foil, carboxyl, amine, and hydroxyl groups are preferred.

Examples of styrene-based elastomers include styrene-butadiene copolymers such as styrene-butadiene-styrene block copolymers; styrene-isoprene copolymers such as styrene-isoprene-styrene block copolymers; styrene-ethylene-butylene-styrene block copolymers; and styrene-ethylene-propylene-styrene block copolymers. In addition to styrene, styrene-based elastomer raw material monomers such as styrene can also include styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene, and 4-cyclohexylstyrene. Among these, styrene-butadiene copolymers and styrene-isoprene copolymers are preferred, and hydrogenated styrene-based thermoplastic elastomers such as hydrogenated styrene-butadiene copolymer resins and hydrogenated styrene-isoprene copolymer resins are more preferred. These are obtained by partially hydrogenating the double bonds of the above-mentioned styrene-butadiene copolymers and styrene-isoprene copolymers.

[(G) Hardening Accelerator] To accelerate the hardening reaction, the thermosetting resin composition may further contain a (G) hardening accelerator. Examples of (G) hardening accelerators include: organophosphorus compounds such as triphenylphosphine; imidazoles and their derivatives; nitrogen-containing compounds such as diamines, tertiary amines, and quaternary ammonium salts; dicumyl peroxide; organic peroxides such as 2,5-dimethyl-2,5-bis(tertiary butylperoxy)hexyne-3, 2,5-dimethyl-2,5-bis(tertiary butylperoxy)hexane, and α,α'-bis(tertiary butylperoxy)diisopropylbenzene; and organometallic salts such as zinc cycloalkanoate, cobalt cycloalkanoate, tin octoate, and cobalt octoate. Among these, organophosphorus compounds are preferred. (G) Curing accelerators may be used alone or in combination of two or more.

(Contents of Each Component in the Thermosetting Resin Composition) The content of each component in the thermosetting resin composition is not particularly limited and can be, for example, within the ranges described below. When the thermosetting resin composition contains component (A), the content of component (A) is preferably 10 to 90 parts by mass, more preferably 20 to 85 parts by mass, and even more preferably 40 to 80 parts by mass, per 100 parts by mass of the total resin components contained in the thermosetting resin composition. When the content of component (A) is at least the lower limit, excellent heat resistance, relative dielectric constant, glass transition temperature, and low thermal expansion properties tend to be achieved. On the other hand, when the content of component (A) is below the upper limit, excellent flowability and moldability tend to be achieved. When the thermosetting resin composition contains component (B), the content of component (B) is preferably 5 to 50 parts by mass, more preferably 10 to 40 parts by mass, and even more preferably 20 to 35 parts by mass, relative to 100 parts by mass of the total resin components contained in the thermosetting resin composition. When the content of component (B) is above the lower limit, excellent heat resistance, glass transition temperature, and low thermal expansion properties tend to be achieved. On the other hand, when the content of component (B) is below the upper limit, excellent heat resistance, relative dielectric constant, glass transition temperature, and low thermal expansion properties tend to be achieved. When the thermosetting resin composition contains component (C), the content of component (C) is preferably 2 to 40 parts by mass, more preferably 5 to 35 parts by mass, and even more preferably 10 to 30 parts by mass, relative to 100 parts by mass of the total resin components contained in the thermosetting resin composition. When the content of component (C) is above the lower limit, excellent heat resistance and relative dielectric constant tend to be achieved. On the other hand, when the content of component (C) is below the upper limit, excellent heat resistance, copper foil adhesion, and low thermal expansion tend to be achieved. When the thermosetting resin composition contains component (D), the content of component (D) is preferably 30 to 200 parts by mass, more preferably 40 to 150 parts by mass, and even more preferably 45 to 120 parts by mass, relative to 100 parts by mass of the total resin components contained in the thermosetting resin composition. When the content of component (D) is at least the lower limit, the composition tends to exhibit excellent low thermal expansion properties. On the other hand, when the content of component (D) is below the upper limit, the composition tends to exhibit excellent heat resistance, fluidity, and moldability. When the thermosetting resin composition contains component (E), the content of component (E) is preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and even more preferably 1 to 3 parts by mass, relative to 100 parts by mass of the total resin components contained in the thermosetting resin composition. When the content of component (E) is above the lower limit, excellent copper foil adhesion and low thermal expansion properties tend to be achieved. On the other hand, when the content of component (E) is below the upper limit, excellent heat resistance tends to be achieved. When the thermosetting resin composition contains component (F), the content of component (F) is preferably 2 to 30 parts by mass, more preferably 5 to 20 parts by mass, and even more preferably 7 to 15 parts by mass, relative to 100 parts by mass of the total resin components contained in the thermosetting resin composition. When the content of component (F) is above the lower limit, the relative dielectric constant tends to be excellent. On the other hand, when the content of component (F) is below the upper limit, heat resistance and copper foil adhesion tend to be excellent. When the thermosetting resin composition contains component (G), the content of component (G) is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 3 parts by mass, and even more preferably 0.2 to 1 part by mass, relative to 100 parts by mass of the total resin components contained in the thermosetting resin composition.

(Other Ingredients) The thermosetting resin composition may further contain the following other ingredients, as long as they do not impair the effects of the present invention: flame retardants, colorants, antioxidants, reducing agents, UV absorbers, fluorescent brighteners, adhesion enhancers, organic fillers, etc. These ingredients may be present singly or in combination, or in combination of two or more.

(Prepreg (p) Manufacturing Method) The method for manufacturing the prepreg (p) used in the manufacturing method of this embodiment is not particularly limited and can be manufactured, for example, by impregnating or coating the glass cloth (g) with the aforementioned thermosetting resin composition and semi-curing (B-stage) it by heating or the like. When impregnating or coating the glass cloth (g) with the thermosetting resin composition, the thermosetting resin composition can be in the form of a varnish diluted with an organic solvent such as methyl ethyl ketone. The non-volatile component concentration in the varnish is, for example, 40 to 80% by mass, preferably 50 to 70% by mass. The drying conditions after impregnation are not particularly limited. The heating temperature is, for example, 120 to 200°C, preferably 140 to 180°C, and the heating time is, for example, 30 seconds to 30 minutes, preferably 1 to 10 minutes.

From the viewpoint of reducing thickness while maintaining good strength, the thickness of the prepreg (p) is preferably 3 to 80 μm, more preferably 5 to 50 μm, more preferably 10 to 40 μm, and particularly preferably 15 to 30 μm.

The content of the thermosetting resin composition in the prepreg (p), calculated as the solid content of the thermosetting resin composition, is preferably 50-90% by mass, more preferably 60-80% by mass, and even more preferably 65-75% by mass. Furthermore, in this embodiment, the term "solid content" refers to components of the composition other than volatile substances such as water and solvents described below. In other words, the term "solid content" also includes substances that are liquid, syrupy, or waxy at room temperature around 25°C, and does not necessarily mean solid.

> Composite Material Manufacturing Method> The composite material manufacturing method of this embodiment includes heating a prepreg (p) containing glass cloth (g) and a thermosetting resin composition to a temperature of 200°C or higher. Herein, the term "heating to 200°C or higher" means that the product temperature (i.e., the prepreg) reaches 200°C or higher. To achieve a product temperature of 200°C or higher, for example, the heating device used can be set to 200°C or higher. From the perspective of improving productivity, the heating temperature in the heating step is preferably 202°C or higher, more preferably 205°C or higher. Furthermore, from the perspective of achieving a uniform curing reaction, the heating temperature is preferably 300°C or lower, and more preferably 250°C or lower. From the perspective of improving productivity and dimensional stability, the heating time in the heating step is preferably 15 to 300 minutes, more preferably 30 to 200 minutes, and even more preferably 60 to 90 minutes. From the perspective of improving productivity and dimensional stability, the pressing pressure in the heating step is preferably 0.2 to 10 MPa, more preferably 1 to 6 MPa, and even more preferably 2 to 4 MPa. In the heating step, conventional forming techniques for laminated and multi-layer sheets for electrical insulation materials can be applied, including multi-stage pressing, multi-stage vacuum pressing, continuous forming, and autoclave forming machines.

The composite material of this embodiment is manufactured by the composite material manufacturing method of this embodiment. In other words, the composite material of this embodiment is manufactured by heating a prepreg (p) containing glass cloth (g) and a thermosetting resin composition to a temperature of 200°C or higher. For example, the prepreg (p) can be heated to a temperature of 200°C or higher to form a cured product, or a laminate containing such a cured product.

[Laminate Plate and Manufacturing Method Thereof] This embodiment provides a method for manufacturing a laminate plate having two or more insulating layers, or having one or more insulating layers and one or more metal foil layers. The insulating layer is a composite material, and the composite material is formed using the composite material manufacturing method of this embodiment.

The laminated plate of this embodiment can be formed by laminating one or more prepregs (p), and the following embodiments (1) to (5) can be cited as examples. (1) A metal-clad laminated plate is formed by laminating a metal foil on one or both sides of a prepreg (p). (2) A laminated plate is formed by laminating two or more prepregs (p). (3) A metal-clad laminated plate is formed by arranging a metal foil on one or both sides of the laminated plate described in (2). (4) A laminated board, which is formed by using the metal-clad laminate described in (3) as a core substrate and further using one or more layers of prepreg (p) to form a multilayer structure. (5) A laminated board, which is formed by using a metal-clad laminate other than the metal-clad laminate described in (3) as a core substrate and further using one or more layers of prepreg (p) to form a multilayer structure. Furthermore, the metal used in the metal foil is not particularly limited as long as it is used as an electrical insulating material. From the perspective of electrical conductivity, the metal foil is preferably copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, or an alloy containing at least one of these metal elements, with copper and aluminum being preferred, and copper being even more preferred. The thickness of the metal foil is not particularly limited and can be appropriately selected depending on the intended use of the printed circuit board. The thickness of the metal foil is preferably 0.5 to 150 μm, more preferably 1 to 100 μm, more preferably 5 to 50 μm, and particularly preferably 5 to 30 μm. When multiple layers of prepreg are used in the composite material manufacturing method of this embodiment, the multiple layers of prepreg may consist solely of prepreg (p), or may be combined with prepreg (p) and prepregs other than prepreg (p). However, from the perspective of dimensional stability, it is preferred to use only prepreg (p). Furthermore, the multiple layers of prepreg (p) may have the same or different shapes and compositions.

The laminated sheet of this embodiment is obtained by stacking and laminating one or more prepreg layers (p) with metal foil, etc., to form the desired structure. The various conditions for the laminated sheet, including heating temperature, heating time, pressurization pressure, and equipment used, are the same as those used in the composite material production process described above. The thickness of the laminated sheet of this embodiment is not particularly limited and can be appropriately determined based on the intended application, for example, within a range of 0.03 to 1.6 mm.

[Printed Wiring Board] The printed wiring board of this embodiment is made using the laminate of this embodiment. The printed wiring board of this embodiment can be manufactured, for example, by performing circuit processing on the copper foil of a copper-clad laminate, which is one aspect of the laminate of this embodiment. Circuit processing can be performed, for example, by forming a resist pattern on the surface of the copper foil, then removing excess copper foil by etching. After removing the resist pattern, the required through-holes are formed using a drill. After forming the resist pattern again, the through-holes are plated to provide a conductive connection, and finally, the resist pattern is removed. A multi-layer printed circuit board can be produced by repeating the following steps as many times as necessary: under the same conditions as above, a copper-clad build-up layer is further laminated on the surface of the obtained printed circuit board and circuit processing is performed.

[Semiconductor Package] The semiconductor package of this embodiment is formed by mounting a semiconductor element on a printed wiring board of this embodiment. This semiconductor package can be manufactured by mounting a semiconductor chip, memory, etc., at a predetermined position on the printed wiring board of this embodiment. [Example]

Next, the present invention is described in more detail with reference to the following embodiments, but these embodiments are not intended to limit the present invention in any sense.

[Evaluation of Dimensional Change] As shown in Figure 1, holes with a diameter of 1.0 mm were drilled in the double-sided copper-clad laminate produced in each example. As shown in Figure 1, the three hole spacings (1-7, 2-6, 3-5) in the warp direction (X) of the glass cloth and the three hole spacings (1-3, 8-4, 7-5) in the weft direction (Y) were measured using a QV-A808P1L-D image measuring machine (manufactured by Mitutoyo). These values were designated as "initial dimensional values." Next, for the four-layer copper-clad laminate produced in each example, the three hole spacings in the warp direction X and the three hole spacings in the weft direction Y of the glass cloth were measured in the same procedure as above. These values were set as the "dimensional values after lamination." Furthermore, for each hole spacing, the "initial dimensional value" - "dimensional value after lamination" was calculated, and this value was set as the "dimensional change S" of the hole spacing. Then, the average value S(x) _{ave , maximum value S(x) max , and minimum value S(x) min of the dimensional variation for the three hole spacings (1-7, 2-6, and 3-5) in the warp direction X, and the average value S(y) ave , maximum value S(y) max , and minimum} value S(y) _min of the dimensional variation for the three hole spacings (1-3, 8-4, and 7-5) in the weft direction Y were calculated. For the warp direction X and weft direction Y, the difference between the maximum value and the average value (maximum value - average value), the difference between the average value and the minimum value (average value - minimum value), and the difference between the maximum value and the minimum value (maximum value - minimum value), respectively, were used as indices for dimensional variation evaluation.

[Prepreg Preparation] [Prepreg Example 1] (Prepreg 1) To prepare prepreg 1, the following components were prepared. (A) Component: A solution of a maleimide compound prepared by the following method. In a 1 L reaction vessel equipped with a thermometer, a stirrer, and a moisture meter with a reflux cooler, 4,4'-diaminodiphenylmethane, bis(4-maleimidophenyl)methane, p-aminophenol, and dimethylacetamide were added to obtain a dimethylacetamide solution of a maleimide compound (Mw = 1,370) having an acidic substituent and an N-substituted maleimide group, which served as a modified maleimide compound. This solution was used as component (A). The weight-average molecular weight (Mw) is calculated by gel permeation chromatography (GPC) from a calibration curve using standard polystyrene. The calibration curve uses standard polystyrene: TSK standard POLYSTYRENE (Types: A-2500, A-5000, F-1, F-2, F-4, F-10, F-20, F-40) [manufactured by Tosoh Co., Ltd.], and is approximated using a cubic equation. The GPC conditions are as follows. Equipment: (Pump: L-6200 [Hitachi High-Technologies Co., Ltd.]), (Detector: L-3300 RI [Hitachi High-Technologies Co., Ltd.]), (Column Oven: L-655A-52 [Hitachi High-Technologies Co., Ltd.]) Column: TSKgel SuperHZ2000 + TSKgel SuperHZ2300 (both Tosoh Co., Ltd.) Column Size: 6.0 mm × 40 mm (Guard Column), 7.8 × 300 mm (Column) Eluent: Tetrahydrofuran Sample Concentration: 20 mg/5 mL Injection Volume: 10 μL Flow Rate: 0.5 mL/min Measurement Temperature: 40°C

(B) Component: Cresol novolac epoxy resin (manufactured by DIC Corporation) (C) Component: Styrene-maleic anhydride copolymer (styrene/maleic anhydride molar ratio = 4, Mw = 11,000) (D) Component: Fused silica treated with an aminosilane coupling agent, average particle size: 1.9 μm, specific surface area: 5.8 m ² /g (E) Component: Dicyandiamide

Next, a resin varnish is prepared by mixing 45 parts by mass of the aforementioned component (A), 30 parts by mass of component (B), 25 parts by mass of component (C), 50 parts by mass of component (D) relative to 100 parts by mass of the total resin components [the sum of components (A) to (C)], and 2 parts by mass of component (E) relative to 100 parts by mass of the total resin components. Methyl ethyl ketone is further added to achieve a non-volatile content of 67% by mass. The amounts of the aforementioned components are expressed as parts by mass of the solid content. For solutions (excluding organic solvents) or dispersions, the amounts are calculated based on the solid content. Glass cloth 1 shown in Table 1 was impregnated with each of the obtained resin varnishes and dried at 160°C for 4 minutes to obtain prepreg 1.

[Production Example 2] (Prepreg 2) Prepreg 2 was produced in the same manner as in Production Example 1, except that the glass cloth shown in Table 1 was replaced with Glass Cloth 2.

[Table 1] Glass cloth 1 Glass cloth 2 Thickness (μm) 23-24 23-24 Basis weight (g/m ² ) 24-26 24-26 Yarn count of warp and weft yarns 100 100 Average warp yarn diameter (μm) 4.5 4.5 Average weft yarn diameter (μm) 5.0 4.5 Average yarn diameter ratio (weft/warp) 1.11 1.00 Weaving density ratio (warp/weft) 1.2～1.3 0.96

[Fabrication of Laminates] [Example 1, Comparative Examples 1-3] (Fabrication of Double-Sided Copper-Clad Laminates) 18 μm thick copper foil "3EC-VLP-18" (manufactured by Mitsui Metals, Inc.) was laminated on both sides of the prepreg listed in Table 2. Heat and pressure molding was performed under the molding conditions listed in Table 2 to produce double-sided copper-clad laminates with a thickness of 0.05 mm.

(Production of a Four-Layer Copper-Clad Laminate) The copper foil on both sides of the double-sided copper-clad laminate produced above was etched away to obtain a resin sheet. The prepregs listed in Table 2 were then stacked one sheet at a time on both sides of the resin sheet. Furthermore, the copper foils described above were stacked one sheet at a time on the prepregs. This was then heated and pressurized under the molding conditions listed in Table 2 to produce a four-layer copper-clad laminate (with the inner layer removed). Using this four-layer copper-clad laminate, the dimensional variation was measured according to the aforementioned method.

[Table 2] *1: Low temperature conditions: 185°C, 2.5 MPa pressure for 70 minutes. High temperature conditions: 205°C, 2.5 MPa pressure for 70 minutes. *2: The values in parentheses represent the difference between the values in the same direction when molding the same prepreg at low temperature. *3: The content of the thermosetting resin composition in the prepreg is 68-70% by mass, calculated as the solid content of the thermosetting resin composition.

As can be seen from Table 2, the laminated sheet of Example 1, produced using the manufacturing method of this embodiment, exhibits relatively small variations in dimensional variation. On the other hand, the laminated sheets of Comparative Examples 1 and 2, which used glass cloth 2 that did not satisfy the average fiber diameter ratio and weave density ratio, and the laminated sheet of Comparative Example 3, which was formed at a molding temperature below 200°C, exhibited relatively large variations in dimensional variation. Furthermore, when glass cloth 2 having an average fiber diameter ratio and weave density ratio that did not meet the requirements of this embodiment was used, the change from low temperature conditions (Comparative Example 1) to high temperature conditions (Comparative Example 2) reduced the dimensional variation in the X direction (S(x) _max - minimum value S(x) _min ) by 47 ppm, and the dimensional variation in the Y direction (S(y) _max - minimum value S(y) _min ) by 22 ppm. On the other hand, when glass cloth 1, which fully satisfies the average fiber diameter ratio and weave density ratio of this embodiment, was used, the change from low-temperature conditions (Comparative Example 3) to high-temperature conditions (Example 1) reduced the dimensional variation in the X direction (S(x) _max - minimum value S(x) _min ) by 86 ppm, and the dimensional variation in the Y direction (S(y) _max - minimum value S(y) _min ) by 175 ppm. This indicates that the reduction in dimensional variation achieved by the composite material manufacturing method of this embodiment is significantly increased by combining glass cloth (g) with molding conditions at a temperature of 200°C or higher.

1-8: Holes X: Warp direction Y: Weft direction

Figure 1 is a schematic diagram of an evaluation test sample showing the variation in dimensional variation.

Domestic storage information (please note the storage institution, date, and number in order) None

Overseas storage information (please note the storage country, institution, date, and number in order) None

Claims (10)

A method for producing a composite material comprises heating a prepreg to a temperature above 200°C. The prepreg comprises glass cloth and a thermosetting resin composition. The glass cloth has an average weft-to-warp diameter ratio (weft/warp) of 1.02 to 1.30, and a warp-to-weft weave density ratio (warp/weft) of 1.2 to 1.3. The thermosetting resin composition comprises: (A) a maleimide compound having an N-substituted maleimide group; (B) an epoxy resin; and (C) a copolymer resin having structural units derived from an aromatic vinyl compound and structural units derived from maleic anhydride. The method for producing a composite material as described in claim 1, wherein the thermosetting resin composition further contains: (D) silicon oxide treated with an aminosilane coupling agent. The method for manufacturing a composite material as described in claim 1, wherein the thickness of the glass cloth is 5 to 50 μm. The method for producing a composite material as described in claim 1, wherein the basis weight of the glass cloth is 12 to 35 g/m ² . A method for manufacturing a laminate having two or more insulating layers, or having one or more insulating layers and one or more metal foil layers, wherein the insulating layer is a composite material, and the composite material is formed by the method for manufacturing a composite material according to any one of claims 1 to 4. A composite material is manufactured by the method for manufacturing a composite material according to any one of claims 1 to 4. A laminate comprising the composite material according to claim 6. A printed circuit board is made using the laminate described in claim 7. A semiconductor package is formed by assembling a semiconductor element on the printed circuit board described in claim 8. A prepreg comprising glass cloth and a thermosetting resin composition. In the glass cloth, the average diameter ratio of weft to warp, i.e., weft/warp, is 1.02 to 1.30, and the warp to weft weave density ratio, i.e., warp/weft, is 1.2 to 1.3. The thermosetting resin composition comprises: (A) a maleimide compound having an N-substituted maleimide group; (B) an epoxy resin having at least two epoxy groups per molecule; and (C) a copolymer resin having structural units derived from an aromatic vinyl compound and structural units derived from maleic anhydride.