Cured products of thermosetting resin compositions, laminates, multilayer printed circuit boards, and semiconductor packages

Abstract

To provide a polymer that can give a novel substrate material; a thermosetting resin composition containing the polymer; and a metal foil with resin, a prepreg, a laminate, a multilayer printed wiring board and a semiconductor package, each of which is prepared using the thermosetting resin composition; and a method for producing the polymer.SOLUTION: A siloxane-modified liquid crystal polymer has a siloxane polymer-derived constitutional unit (1), a liquid crystal polymer-derived constitutional unit (2), and a constitutional unit (3) having an ethylenically unsaturated bond-containing group.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to siloxane-modified liquid crystal polymers, thermosetting resin compositions, resin-coated metal foils, prepregs, laminates, multilayer printed circuit boards and semiconductor packages, and methods for producing siloxane-modified liquid crystal polymers. [Background technology]

[0002] In recent years, with the increasing sophistication of information terminal devices such as smartphones and tablet PCs, the semiconductor packages used in them have been rapidly becoming smaller, thinner, and more densely packed. Furthermore, the fifth-generation mobile information communication (5G), which began to be introduced in 2019, has dramatically improved functions such as high speed, large capacity, massive simultaneous connections, and ultra-low latency, and is expected to usher in a full-fledged IoT (Internet of Things) era where everything is connected. Next-generation information and communication systems, such as 5G, utilize higher frequency bands for signal transmission than conventional systems. While higher frequency bands increase the amount of information that can be transmitted per unit time, enabling higher speeds and larger capacities, they also lead to problems such as increased transmission loss (see, for example, Patent Document 1). Therefore, there is a strong demand for substrate materials with reduced transmission loss. However, at the same time, various other properties, such as low warpage, are also required, and balancing these properties is crucial. As a result, research and development of substrate materials has become extremely complex and diverse. Consequently, developing as many new substrate materials as possible is currently one of the most important themes. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Excerpt from Japanese Patent Publication No. 2020-045385, paragraph

[0003] [Overview of the project] [Problems that the invention aims to solve]

[0004] Therefore, the object of this disclosure is to provide a polymer that can provide a novel substrate material, a thermosetting resin composition containing the polymer, a resin-coated metal foil, a prepreg, a laminate, a multilayer printed circuit board, and a semiconductor package using the thermosetting resin composition, and a method for producing the polymer. [Means for solving the problem]

[0005] As a result of diligent research, the present inventors have found that a specific siloxane-modified liquid crystal polymer and a thermosetting resin composition containing the siloxane-modified liquid crystal polymer can achieve the above objective.

[0006] In other words, one aspect of this embodiment includes the following [1] to

[15] . [1] A siloxane-modified liquid crystal polymer having a structural unit (1) derived from a siloxane polymer, a structural unit (2) derived from a liquid crystal polymer, and a structural unit (3) having an ethylenically unsaturated bond-containing group. [2] The siloxane-modified liquid crystal polymer according to [1] above, wherein the content of the structural unit (1) is 0.1 to 35% by mass. [3] The siloxane-modified liquid crystal polymer according to [1] or [2] above, wherein the content of the structural unit (2) is 10 to 98% by mass. [4] The liquid crystal polymer constituting the structural unit (2) is one or more polymerizable compounds selected from the group consisting of aromatic hydroxycarboxylic acid, acylates of aromatic hydroxycarboxylic acid, esterified products of aromatic hydroxycarboxylic acid, aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acids, esterified products of aromatic dicarboxylic acids, aromatic dicarboxylic acid dihalides, aromatic diols, acylates of aromatic diols, aromatic aminocarboxylic acids, acylates of aromatic aminocarboxylic acids, esterified products of aromatic aminocarboxylic acids, aromatic aminocarboxylic acid halides, aromatic hydroxyamines, acylates of aromatic hydroxyamines, aromatic diamines, acylates of aromatic diamines, aliphatic diols, acylates of aliphatic diols, aliphatic dicarboxylic acids, esterified products of aliphatic dicarboxylic acids, and aliphatic dicarboxylic acid dihalides, and has a structural unit derived therefrom. The siloxane-modified liquid crystal polymer according to any one of [1] to [3] above. [5] The siloxane-modified liquid crystal polymer according to any one of [1] to [4] above, having a structural unit (3) having an ethylenically unsaturated bond-containing group at a molecular end. [6] The siloxane-modified liquid crystal polymer according to any one of [1] to [5] above, wherein the ethylenically unsaturated bond is one or more selected from the group consisting of an unsaturated aliphatic hydrocarbon group (3-i) and a group (3-ii) containing a hetero atom and an ethylenically unsaturated bond. [7] The siloxane-modified liquid crystal polymer according to any one of [1] to [6] above, wherein the ethylenically unsaturated bond-containing group is a (meth)acryloyl group. [8] A thermosetting resin composition containing the siloxane-modified liquid crystal polymer according to any one of [1] to [7] above. [9] A metal foil with a resin, having a layer of the thermosetting resin composition according to [8] above on a metal foil.

[10] A prepreg comprising the thermosetting resin composition according to [8] above and a sheet-like fiber reinforcing base material.

[11] A laminate comprising (i) the metal foil with a resin according to [9] above or (ii) the prepreg according to

[10] above and a metal foil.

[12] A multilayer printed wiring board comprising (i) a metal foil with resin as described in [9] above, (ii) a prepreg as described in

[10] above, or (iii) a laminate as described in

[11] above.

[13] A semiconductor package formed by mounting a semiconductor element on the multilayer printed wiring board described in

[12] above.

[14] Siloxane diol (1-a) and, One or more polymerizable compounds (2-a) selected from the group consisting of aromatic diols, aliphatic diols, aromatic hydroxyamines, and aromatic diamines, One or more polymerizable compounds (2-b) selected from the group consisting of aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acid dihalides, aromatic aminocarboxylic acid halides, and aliphatic dicarboxylic acid dihalides, (Meth)acrylic acid halide (3-a), are mixed in an organic solvent, Furthermore, a method for producing a siloxane-modified liquid crystal polymer by adding a base having a pKa of 9 or more and reacting them.

[15] The method for producing a siloxane-modified liquid crystal polymer according to

[14] above, wherein the base having a pKa of 9 or more is one or more selected from the group consisting of 4-dimethylaminopyridine, trimethylamine, triethylamine, N,N-diisopropylethylamine, diazabicyclononene, and diazabicycloundecene.

Advantages of the Invention

[0007] According to the present disclosure, a siloxane-modified liquid crystal polymer capable of providing a novel substrate material can be provided. Further, a thermosetting resin composition containing the siloxane-modified liquid crystal polymer, a metal foil with resin, a prepreg, a laminate, a multilayer printed wiring board, and a semiconductor package using the thermosetting resin composition, and a method for producing the polymer can be provided.

Brief Description of the Drawings

[0008] [Figure 1] The 1H NMR measurement result of the siloxane-modified liquid crystal polymer produced in Example 1. [Figure 2]This is a magnified view of the peak shown in Figure 1, specifically the 7.5–6.8 ppm range. [Modes for carrying out the invention]

[0009] In the numerical ranges described herein, the upper or lower limits of those ranges may be replaced with the values ​​shown in the examples. Furthermore, the lower and upper limits of a numerical range can be arbitrarily combined with the lower or upper limits of other numerical ranges. In the notation "AA~BB" for a numerical range, the numbers AA and BB at both ends are included in the range as the lower and upper limits, respectively. Furthermore, unless otherwise specified, each component and material exemplified herein may be used alone or in combination of two or more. In this specification, the content of each component in a composition means the total amount of multiple substances present in the composition, unless otherwise specified, if multiple substances corresponding to each component are present in the composition. In this specification, for example, the phrase "10 or more" means 10 and numbers greater than 10, and the same applies to numbers that are different. Similarly, for example, the phrase "10 or less" means 10 and numbers less than 10, and the same applies to numbers that are different. In this specification, "structural units derived from CC" refers to the structural units that compound CC constitutes when compound CC is used as a starting material in a reaction. Embodiments that combine any combination of the information described herein are also included.

[0010] In this specification, "solids" refers to components in the resin composition other than water and volatile substances such as solvents described later. In other words, the solids include liquid, syrup-like, or waxy substances at room temperature around 25°C, and do not necessarily mean solids.

[0011] [Siloxane-modified liquid crystal polymer] One embodiment of this model is a siloxane-modified liquid crystal polymer having a structural unit (1) derived from a siloxane polymer [hereinafter sometimes abbreviated as "structural unit (1)"], a structural unit (2) derived from a liquid crystal polymer [hereinafter sometimes abbreviated as "structural unit (2)"], and a structural unit (3) having an ethylenically unsaturated bond-containing group [hereinafter sometimes abbreviated as "structural unit (3)"]. The structural units of the siloxane-modified liquid crystal polymer of this embodiment will be described in order below.

[0012] (Structural unit derived from siloxane polymer (1)) The siloxane polymer constituting structural unit (1) is not particularly limited as long as it contains a siloxane skeleton. In other words, the siloxane polymer is only required to contain a structural unit represented by the following general formula (1-1). [ka] (In the formula, R a1 and R a2 Each of these independently represents an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a phenyl group having a substituent.

[0013] Let's explain each element in general formula (1-1). R a1 and R a2 Examples of C1-C5 alkyl groups represented by include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, t-butyl group, and n-pentyl group. C1-C3 alkyl groups are preferred, and methyl groups are more preferred. In the "phenyl group having a substituent", examples of the substituent of the phenyl group include an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms, and an alkynyl group having 2 to 5 carbon atoms. Examples of the alkyl group having 1 to 5 carbon atoms are the same as those described above. Examples of the alkenyl group having 2 to 5 carbon atoms include a vinyl group and an allyl group. Examples of the alkynyl group having 2 to 5 carbon atoms include an ethynyl group and a propargyl group. R a1 and R a2 are both preferably an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group.

[0014] Examples of the siloxane polymer include siloxane diol and siloxane diamine. The siloxane diol preferably has a hydroxy group at the molecular terminal. The siloxane diamine preferably has an amino group at the molecular terminal. Also, from the viewpoint of low transmission loss, the siloxane polymer is preferably siloxane diol, and more preferably siloxane diol represented by the following general formula (1-1'). [Chemical formula] (In the formula, R a1 and R a2 are the same as those in the general formula (1-1). R a3 and R a4 each independently represent an alkyl group having 1 to 5 carbon atoms, a phenyl group, or a phenyl group having a substituent. R a5 and R a6 each independently represent a divalent organic group, and m1 is an integer of 2 to 100.) <00001​​​​​​​​​​​It is explained in the same way as in the explanation in R. a3 and R a4 A methyl group is preferred as the component. R a5 and R a6 Examples of divalent organic groups include alkylene groups, alkenylene groups, alkylene groups, arylene groups, -O- groups, or divalent linking groups formed by combinations thereof. Examples of alkylene groups include alkylene groups having 1 to 10 carbon atoms, such as methylene groups, ethylene groups, and propylene groups. Examples of alkenylene groups include alkenylene groups having 2 to 10 carbon atoms. Examples of alkylene groups include alkylene groups having 2 to 10 carbon atoms. Examples of arylene groups include arylene groups having 6 to 20 carbon atoms, such as phenylene groups and naphthylene groups. The aforementioned "divalent linking group formed by the combination of these" refers to a divalent linking group formed by the combination of one or more groups selected from the group consisting of alkylene groups, alkenylene groups, alkynylene groups, arylene groups, and -O-. Examples include combinations of an alkylene group and an arylene group, an alkylene group and -O-, an alkenylene group and an arylene group, an alkynylene group and an arylene group, and an arylene group and -O-. Among the above, R a5 and R a6 Preferably, the group is an alkylene group or an arylene group. m1 is preferably an integer between 2 and 50, more preferably an integer between 3 and 40, even more preferably an integer between 5 and 30, and even more preferably an integer between 7 and 30.

[0016] There are no particular restrictions on the functional group equivalent of the siloxane polymer, but it is preferably 50 to 4,000 g / mol, more preferably 100 to 3,000 g / mol, even more preferably 150 to 1,800 g / mol, and particularly preferably 200 to 1,300 g / mol, and may also be 500 to 1,300 g / mol. Commercially available siloxane polymers can be used. Examples of commercially available products include "KF-6000" (functional group equivalent: 470 g / mol), "KF-6001" (functional group equivalent: 900 g / mol), "KF-6002" (functional group equivalent: 1,600 g / mol), "KF-6003" (functional group equivalent: 2,500 g / mol), "X-21-5841" (functional group equivalent: 500 g / mol), and "KF-9701" (functional group equivalent: 1,500 g / mol) [all manufactured by Shin-Etsu Chemical Co., Ltd.]. [Manufactured by Gaku Kogyo Co., Ltd.]; "XC96-723" (Functional group equivalent: 200 g / mol), "XF42-B0970" (Functional group equivalent: 900 g / mol) [The above are manufactured by Momentive Performance Materials Japan LLC]; "SF8427" (Functional group equivalent: 1,200 g / mol), "BY16-201" (Functional group equivalent: 1,600 g / mol), "SF8428" (Functional group equivalent: 1,600 g / mol) l) [Manufactured by Toray Dow Corning Co., Ltd.]; "DMS-S12" (Functional group equivalent: 300 g / mol), "DMS-S14" (Functional group equivalent: 600 g / mol), "DMS-S15" (Functional group equivalent: 1,400 g / mol), "DMS-S21" (Functional group equivalent: 2,100 g / mol) [Manufactured by Gelest Co., Ltd.]; "KF-8010" (Functional group equivalent: 430 g / mol), "X-22-161A" (Functional group Examples include "X-22-161B" (equivalent weight: 800 g / mol), "KF-8012" (equivalent weight: 2,200 g / mol), "KF-8008" (equivalent weight: 5,700 g / mol), "X-22-9409" (equivalent weight: 670 g / mol), and "X-22-1660B-3" (equivalent weight: 2,200 g / mol) [all manufactured by Shin-Etsu Chemical Co., Ltd.].

[0017] (Structural units derived from liquid crystal polymers (2)) The liquid crystal polymer constituting the structural unit (2) is not particularly limited, and any liquid crystal polymer (liquid crystal polyester) can be used. The liquid crystal polymer preferably has structural units derived from one or more polymerizable compounds selected from the group consisting of aromatic hydroxycarboxylic acids, aromatic hydroxycarboxylic acid acylates, aromatic hydroxycarboxylic acid esters, aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acids, aromatic dicarboxylic acid esters, aromatic dicarboxylic acid dihalides, aromatic diols, aromatic diols acylates, aromatic aminocarboxylic acids, aromatic aminocarboxylic acid acylates, aromatic aminocarboxylic acid halides, aromatic hydroxyamines, aromatic hydroxyamines acylates, aromatic diamines, aromatic diamines acylates, aliphatic diols, aliphatic diols acylates, aliphatic dicarboxylic acids, aliphatic dicarboxylic acid esters, and aliphatic dicarboxylic acid dihalides. From the viewpoint of being able to employ solution polymerization in the production of liquid crystal polymers, it is more preferable that the liquid crystal polymer has structural units derived from one or more polymerizable compounds selected from the group consisting of aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acid dihalides, aromatic diols, aromatic aminocarboxylic acid halides, aromatic hydroxyamines, aromatic diamines, aliphatic diols, and aliphatic dicarboxylic acid dihalides, and it is even more preferable that it has structural units derived from aromatic dicarboxylic acid dihalides and structural units derived from aromatic diols. The polymerizable compounds that form the structural units of the liquid crystal polymer will be described in order below.

[0018] (Aromatic hydroxycarboxylic acids, acylated aromatic hydroxycarboxylic acids, esterified aromatic hydroxycarboxylic acids, aromatic hydroxycarboxylic acid halides) Aromatic hydroxycarboxylic acids are compounds in which a hydroxyl group and a carboxylic acid group are directly bonded to an aromatic hydrocarbon. To that extent, even if an aliphatic hydrocarbon group is present, it is still classified as an aromatic hydroxycarboxylic acid. Specific examples of aromatic hydroxycarboxylic acids include 4-hydroxybenzoic acid, 3-hydroxybenzoic acid, 2-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 6-hydroxy-1-naphthoic acid, 7-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, 7-hydroxy-1-naphthoic acid, 4'-hydroxyphenyl-4-benzoic acid, 3'-hydroxyphenyl-4-benzoic acid, 4'-hydroxyphenyl-3-benzoic acid, as well as alkyl-substituted derivatives thereof, alkoxyl-substituted derivatives thereof, and halogen-substituted derivatives thereof. Alkyl-substituted derivatives are not particularly limited, but examples include those substituted with alkyl groups having 1 to 6 carbon atoms. Alkoxyl-substituted derivatives are not particularly limited, but examples include those substituted with alkoxyl groups having 1 to 6 carbon atoms. Halogen-substituted derivatives are not particularly limited, but examples include those substituted with fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. Aromatic hydroxycarboxylic acids may be used individually or in combination of two or more.

[0019] Examples of acylated aromatic hydroxycarboxylic acids include acylated compounds of the aforementioned aromatic hydroxycarboxylic acids. In this specification, an acylated compound is defined as a compound in which a hydrogen atom of a hydroxyl group (-OH) is replaced by an acyl group, resulting in -OC(=O)-R A (R A The group is an alkyl group or an aryl group. This refers to a compound in which the group has become an alkyl group or an aryl group. Aromatic hydroxycarboxylic acid acylates may be used individually or in combination of two or more types. Examples of esterified aromatic hydroxycarboxylic acids include esterified versions of the aforementioned aromatic hydroxycarboxylic acids. In this specification, an esterified product is defined as a product in which the hydroxyl group (-OH) of a carboxylic acid group (-C(=O)-OH) is converted into an alcohol (R B OH)'s -OR B Substituted with -C(=O)-OR B (R BThe group is an alkyl group or an aryl group. This refers to a compound that has become ( ). Esterified aromatic hydroxycarboxylic acids may be used individually or in combination of two or more.

[0020] Examples of aromatic hydroxycarboxylic acid halides include acid halides, which are specific examples of aromatic hydroxycarboxylic acids. In this specification, an acid halide is a compound in which the hydroxyl group (-OH) of a carboxylic acid group (-C(=O)-OH) is substituted with a halogen atom. Examples of acid halides include acid fluorides, acid chlorides, acid bromides, and acid iodides. Although not particularly limited, acid halides are preferably acid chlorides from the viewpoint of reactivity and availability of raw materials. Aromatic hydroxycarboxylic acid halides may be used individually or in combination of two or more types.

[0021] (Aromatic dicarboxylic acids, esterified aromatic dicarboxylic acids, dihalides of aromatic dicarboxylic acids) Aromatic dicarboxylic acids are compounds in which a carboxylic acid group is directly bonded to an aromatic hydrocarbon. To that extent, even if an aliphatic hydrocarbon group is present, it is still classified as an aromatic dicarboxylic acid. Specific examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4'-dicarboxybiphenyl, 3,4'-dicarboxybiphenyl, 4,4'-dicarboxyterphenyl, and alkyl-substituted derivatives thereof, alkoxyl-substituted derivatives thereof, and halogen-substituted derivatives thereof. Alkyl-substituted derivatives are not particularly limited, but examples include those substituted with alkyl groups having 1 to 6 carbon atoms. Alkoxyl-substituted derivatives are not particularly limited, but examples include those substituted with alkoxyl groups having 1 to 6 carbon atoms. Halogen-substituted derivatives are not particularly limited, but examples include those substituted with fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. Aromatic dicarboxylic acids may be used individually or in combination of two or more.

[0022] Examples of esterified aromatic dicarboxylic acids include monoesterified and diesterified versions of the aforementioned aromatic dicarboxylic acids. The esterified aromatic dicarboxylic acid may be used individually or in combination of two or more types. Examples of aromatic dicarboxylic acid dihalides include acid halides of the aforementioned aromatic dicarboxylic acids. Examples of acid halides include acid fluorides, acid chlorides, acid bromides, and acid iodides. While not particularly limited, acid halides are preferred from the viewpoint of reactivity and availability of raw materials. Preferred aromatic dicarboxylic acid dihalides are terephthalic acid dihalide and isophthalic acid dihalide, more preferably terephthalic acid dichloride and isophthalic acid dichloride, and even more preferably isophthalic acid dichloride. Aromatic dicarboxylic acid dihalides may be used individually or in combination of two or more.

[0023] (Aromatic diols, acylated aromatic diols) Aromatic diols are compounds in which a hydroxyl group is directly bonded to an aromatic hydrocarbon. To that extent, even if an aliphatic hydrocarbon group is present, it is still classified as an aromatic diol. Specific examples of aromatic diols include benzene-based diols such as hydroquinone and resorcinol; naphthalene-based diols such as 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, and 1,6-dihydroxynaphthalene; binaphthyl-based diols such as 2,2'-dihydroxybinaphthyl; biphenyl-based diols such as 3,3'-dihydroxybiphenyl, 3,4'-dihydroxybiphenyl, and 4,4'-dihydroxybiphenyl; diphenyl ether-based diols such as 4,4'-dihydroxydiphenyl ether; bisphenol-based diols such as bisphenol A and bisphenol F; and alkyl-substituted derivatives thereof, alkoxyl-substituted derivatives thereof, and halogen-substituted derivatives thereof. Alkyl-substituted derivatives are not particularly limited, but examples include those substituted with alkyl groups having 1 to 6 carbon atoms. Alkoxyl-substituted derivatives are not particularly limited, but examples include those substituted with alkoxyl groups having 1 to 6 carbon atoms. While there are no particular limitations on halogen substitutions, examples include those with fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, and the like. Among the aromatic diols mentioned above, biphenyl diols and bisphenol diols are preferred, 4,4'-dihydroxybiphenyl, bisphenol A, and bisphenol F are more preferred, and 4,4'-dihydroxybiphenyl and bisphenol A are even more preferred. Aromatic diols may be used individually or in combination of two or more. In particular, it is preferable to use two or more aromatic diols in combination for the following reason: The solubility of aromatic diols in organic solvents tends to improve when they contain bisphenol A. For this reason, it is preferable that the aromatic diols contain biphenyl diols and bisphenol diols, and more preferably 4,4'-dihydroxybiphenyl and bisphenol A.

[0024] Examples of acylated aromatic diols include acylated versions of the aforementioned aromatic diols. The acylated aromatic diols may be used individually or in combination of two or more.

[0025] (Aromatic aminocarboxylic acids, acylated aromatic aminocarboxylic acids, esterified aromatic aminocarboxylic acids, aromatic aminocarboxylic acid halides) Aromatic aminocarboxylic acids are compounds in which an amino group and a carboxylic acid group are directly bonded to an aromatic hydrocarbon. To that extent, even if an aliphatic hydrocarbon group is present, it is still classified as an aromatic aminocarboxylic acid. Specific examples of aromatic aminocarboxylic acids include 4-aminobenzoic acid, 3-aminobenzoic acid, 6-amino-2-naphthoic acid, and alkyl-substituted derivatives thereof, alkoxyl-substituted derivatives thereof, and halogen-substituted derivatives thereof. Alkyl-substituted derivatives are not particularly limited, but examples include those substituted with alkyl groups having 1 to 6 carbon atoms. Alkoxyl-substituted derivatives are not particularly limited, but examples include those substituted with alkoxyl groups having 1 to 6 carbon atoms. Halogen-substituted derivatives are not particularly limited, but examples include those substituted with fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. Aromatic aminocarboxylic acids may be used individually or in combination of two or more types.

[0026] Examples of acylated aromatic aminocarboxylic acids include acylated versions of the aforementioned aromatic aminocarboxylic acids. A single acylated aromatic aminocarboxylic acid may be used, or two or more may be used in combination. Examples of esterified aromatic aminocarboxylic acids include esterified versions of specific aromatic aminocarboxylic acids. One type of esterified aromatic aminocarboxylic acid may be used alone, or two or more types may be used in combination. Examples of aromatic aminocarboxylic acid halides include acid halides of the aforementioned aromatic aminocarboxylic acids. Examples of acid halides include acid fluorides, acid chlorides, acid bromides, acid iodides, etc. While not particularly limited, acid halides are preferred from the viewpoint of reactivity and availability of raw materials. Aromatic aminocarboxylic acid halides may be used individually or in combination of two or more.

[0027] (Aromatic hydroxyamines, aromatic hydroxyamine acylates) Aromatic hydroxyamines are compounds in which a hydroxyl group and an amino group are directly bonded to an aromatic hydrocarbon. To that extent, even if they contain an aliphatic hydrocarbon group, they are classified as aromatic hydroxyamines. Specific examples of aromatic hydroxyamines include 4-aminophenol, N-methyl-4-aminophenol, 3-aminophenol, 3-methyl-4-aminophenol, 4-amino-1-naphthol, 4-amino-4'-hydroxybiphenyl, 4-amino-4'-hydroxybiphenyl ether, 4-amino-4'-hydroxybiphenylmethane, 4-amino-4'-hydroxybiphenyl sulfide, 2,2'-diaminobinaphthyl, and alkyl-substituted derivatives thereof, alkoxyl-substituted derivatives thereof, and halogen-substituted derivatives thereof. Alkyl-substituted derivatives are not particularly limited, but examples include those substituted with alkyl groups having 1 to 6 carbon atoms. Alkoxyl-substituted derivatives are not particularly limited, but examples include those substituted with alkoxyl groups having 1 to 6 carbon atoms. Halogen-substituted derivatives are not particularly limited, but examples include those substituted with fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. Aromatic hydroxyamines may be used individually or in combination of two or more.

[0028] Examples of acylated aromatic hydroxyamines include acylated versions of the aforementioned aromatic hydroxyamines. A single acylated aromatic hydroxyamine may be used, or two or more may be used in combination.

[0029] (Aromatic diamines, aromatic diamine acylates) Aromatic diamines are compounds in which an amino group is directly bonded to an aromatic hydrocarbon. To that extent, even if they contain an aliphatic hydrocarbon group, they are still classified as aromatic diamines. Specific examples of aromatic diamines include 1,4-phenylenediamine, 1,3-phenylenediamine, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, and alkyl-substituted derivatives thereof, alkoxyl-substituted derivatives thereof, and halogen-substituted derivatives thereof. Alkyl-substituted derivatives are not particularly limited, but examples include those substituted with alkyl groups having 1 to 6 carbon atoms. Alkoxyl-substituted derivatives are not particularly limited, but examples include those substituted with alkoxyl groups having 1 to 6 carbon atoms. Halogen-substituted derivatives are not particularly limited, but examples include those substituted with fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. Aromatic diamines may be used individually or in combination of two or more types.

[0030] Examples of acylated aromatic diamines include acylated versions of the aforementioned aromatic diamines. A single acylated aromatic diamine may be used, or two or more may be used in combination.

[0031] (Aliphatic diols, acylated aliphatic diols) Aliphatic diols are compounds in which a hydroxyl group is directly bonded to an aliphatic hydrocarbon. To that extent, even if an aromatic hydrocarbon group is present, it is still classified as an aliphatic diol. It is preferable that aliphatic diols do not have an aromatic hydrocarbon group. Specific examples of aliphatic diols include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 2,2-bis(4-hydroxycyclohexyl)propane, 1,4-cyclohexadiol, 4,4'-bicyclohexanol, and tricyclodecanedimethanol. Aliphatic diols may be used individually or in combination of two or more. Examples of acylated aliphatic diols include acylated versions of the aforementioned specific aliphatic diols. The acylated aliphatic diols may be used individually or in combination of two or more types.

[0032] (Aliphatic dicarboxylic acids, esterified aliphatic dicarboxylic acids, dihalides of aliphatic dicarboxylic acids) Aliphatic dicarboxylic acids are compounds in which a carboxylic acid group is directly bonded to an aliphatic hydrocarbon. To that extent, even if an aromatic hydrocarbon group is present, it is classified as an aliphatic dicarboxylic acid. It is preferable that aliphatic dicarboxylic acids do not have an aromatic hydrocarbon group. Specific examples of aliphatic dicarboxylic acids include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanediic acid. Aliphatic dicarboxylic acids may be used individually or in combination of two or more. Examples of esterified aliphatic dicarboxylic acids include esterified versions of the aforementioned specific aliphatic dicarboxylic acids. The esterified aliphatic dicarboxylic acid may be used individually or in combination of two or more types. Examples of aliphatic dicarboxylic acid dihalides include acid halides, which are specific examples of aliphatic dicarboxylic acids. Examples of acid halides include acid fluorides, acid chlorides, acid bromides, acid iodides, etc. Although not particularly limited, acid chlorides are preferred as acid halides from the viewpoint of reactivity and availability of raw materials. One aliphatic dicarboxylic acid dihalide may be used alone, or two or more may be used in combination.

[0033] (Structural unit (3) containing an ethylenically unsaturated bond) Examples of ethylenically unsaturated bond-containing groups of structural unit (3) include unsaturated aliphatic hydrocarbon groups (3-i) such as vinyl groups, allyl groups, 1-methylallyl groups, isopropenyl groups, 2-butenyl groups, 3-butenyl groups, and styryl groups; and groups (3-ii) that contain a heteroatom and an ethylenically unsaturated bond, such as maleimide groups and groups represented by the following general formula (3-1). Preferably, the ethylenically unsaturated bond-containing group is one or more selected from the group consisting of unsaturated aliphatic hydrocarbon groups (3-i) and groups (3-ii) that contain a heteroatom and an ethylenically unsaturated bond. [ka] (In the formula, R b1 (This represents a hydrogen atom or an alkyl group having 1 to 20 carbon atoms.)

[0034] In this specification, groups that have a portion of an unsaturated aliphatic hydrocarbon group, such as a maleimide group or the group represented by the general formula (3-1) above, but cannot be considered an unsaturated aliphatic hydrocarbon group when viewed as a whole, are not included in the term "unsaturated aliphatic hydrocarbon group".

[0035] R in general formula (3-1) b1 The alkyl group having 1 to 20 carbon atoms represented by may be a linear alkyl group, a branched alkyl group, or a cyclic alkyl group, with linear alkyl groups being preferred. The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 5, even more preferably 1 to 3, and particularly preferred to be 1. Examples of the alkyl group include methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, decyl group, pentadecyl group, hexadecyl group, heptadecyl group, etc., and among these, the methyl group is preferred. The group represented by the above general formula (3-1) is preferably a group (3-ii) containing a heteroatom and an ethylenically unsaturated bond, from the viewpoint of solubility in organic solvents, and is a (meth)acryloyl group (i.e., R in the above general formula (3-1)). b1 However, it is more preferable that the group is a hydrogen atom or a methyl group, and even more preferable that it is a methacryloyl group. In this embodiment, "(meth)acryloyl group" means an acryloyl group or a methacryloyl group. In this embodiment, it is preferable that the siloxane-modified liquid crystal polymer has structural unit (3) at the molecular end.

[0036] (Content of each structural unit) The siloxane-modified liquid crystal polymer of this embodiment preferably contains 0.1 to 35% by mass of structural units (1) derived from the siloxane polymer, more preferably 0.5 to 30% by mass, even more preferably 1 to 30% by mass, and may also contain 2 to 20% by mass, 2 to 15% by mass, or 2.5 to 13% by mass. The siloxane-modified liquid crystal polymer of this embodiment preferably contains 10 to 98% by mass of structural units (2) derived from the liquid crystal polymer, more preferably 25 to 98% by mass, even more preferably 50 to 98% by mass, and may also contain 65 to 96% by mass, 65 to 93% by mass, or 75 to 91% by mass. The siloxane-modified liquid crystal polymer of this embodiment preferably contains 1 to 40% by mass of structural units (3) having ethylenically unsaturated bond-containing groups, more preferably 1 to 30% by mass, even more preferably 1 to 20% by mass, and may also contain 1.5 to 15% by mass, 3 to 15% by mass, or 4 to 13% by mass. Furthermore, the siloxane-modified liquid crystal polymer of this embodiment may have structural units other than the structural units (1) to (3) described above. However, the total content of structural units (1) to (3) is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more (all including 100% by mass) relative to the total structural units. The content of each of the above structural units is: 1 This value was obtained by determining the molar ratio of each component from the H-NMR measurement results and then converting it to a mass ratio.

[0037] There are no particular restrictions on the molecular weight of the siloxane-modified liquid crystal polymer in this embodiment, but from the viewpoint of solubility in organic solvents, the weight-average molecular weight may be 1,000 to 10,000, 1,200 to 9,000, or 1,500 to 7,000. Similarly, from the same viewpoint, the number-average molecular weight of the siloxane-modified liquid crystal polymer in this embodiment may be 500 to 3,000, 800 to 2,500, or 1,000 to 2,300.

[0038] [Method for producing siloxane-modified liquid crystal polymers] The method for producing the siloxane-modified liquid crystal polymer in this embodiment is not particularly limited, but from the viewpoint of suppressing the thermal decomposition of the siloxane polymer used as a raw material, a solution polymerization method is preferred. Furthermore, in the solution polymerization method, the following production method is preferred from the viewpoint of suppressing the thermal decomposition of the siloxane polymer and from the viewpoint of suppressing side reactions and sufficiently introducing the structural unit (3). (A preferred embodiment of a method for producing siloxane-modified liquid crystal polymers) Siloxanediol (1-a) and, One or more polymerizable compounds (2-a) selected from the group consisting of aromatic diols, aliphatic diols, aromatic hydroxyamines, and aromatic diamines, One or more polymerizable compounds (2-b) selected from the group consisting of aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acid dihalides, aromatic aminocarboxylic acid halides, and aliphatic dicarboxylic acid dihalides, (Meth)acrylate halide (3-a) is mixed in an organic solvent. Furthermore, a method for producing siloxane-modified liquid crystal polymers by adding a base with a pKa of 9 or higher and reacting it. A preferred embodiment of the method for producing the siloxane-modified liquid crystal polymer (hereinafter sometimes referred to as the "method of production of this embodiment") will be described below.

[0039] (Regarding raw materials) Siloxanediol (1-a) is the same as the siloxanediol described in the description of structural unit (1) derived from siloxane polymer, and the same description applies. The aromatic diols, aliphatic diols, aromatic hydroxyamines, and aromatic diamines, which are options for polymerizable compound (2-a), are the same as the aromatic diols, aliphatic diols, aromatic hydroxyamines, and aromatic diamines described in the description of structural units (2) derived from liquid crystal polymers, and the same description applies. The options for polymerizable compound (2-b), aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acid dihalides, aromatic aminocarboxylic acid halides, and aliphatic dicarboxylic acid dihalides, are the same as the aromatic hydroxycarboxylic acid halides, aromatic dicarboxylic acid dihalides, aromatic aminocarboxylic acid halides, and aliphatic dicarboxylic acid dihalides described in the description of structural units (2) derived from liquid crystal polymers, and the same description applies. (Meth)acrylate halide (3-a) is a compound that constitutes structural unit (3) having an ethylenically unsaturated bond-containing group. Examples of (meth)acrylate halide (3-a) include (meth)acrylate fluoride, (meth)acrylate chloride, (meth)acrylate bromide, and (meth)acrylate iodide. There are no particular limitations, but from the viewpoint of reactivity, (meth)acrylate chloride is preferred as (meth)acrylate halide (3-a), and methacrylate chloride is more preferred.

[0040] (For bases with a pKa of 9 or higher) Bases with a pKa of 9 or higher have the function of promoting esterification reactions. If the pKa of the base is less than 9, many side reactions originating from the acid halide (3-a) tend to proceed, which prevents the introduction of the (meth)acryloyl group into the target product. Therefore, the pKa of the base is 9 or higher, preferably 9.5 or higher, more preferably 10.0 or higher, and even more preferably 10.5 or higher. There is no particular upper limit to the pKa of the base, but it is usually 14 or lower, and may also be 13 or lower. Examples of bases with a pKa of 9 or higher include 4-dimethylaminopyridine, trimethylamine, triethylamine, N,N-diisopropylethylamine, diazabicyclononene, and diazabicycloundecene. Among these, it is preferable that the base with a pKa of 9 or higher be one or more selected from the group consisting of trimethylamine and triethylamine.

[0041] (Amount of each raw material and base with a pKa of 9 or higher used) The amounts used for siloxane diol (1-a), polymerizable compound (2-a), polymerizable compound (2-b), (meth)acrylate halide (3-a), and bases with a pKa of 9 or higher are not particularly limited, but from the viewpoint of the solubility of the resulting siloxane-modified liquid crystal polymer in organic solvents, the amounts listed in Table 1 below are preferred. [Table 1]

[0042] Furthermore, when the amount of base with a pKa of 9 or higher is above the lower limit of the range shown in Table 1, the esterification reaction tends to be sufficiently promoted, and when it is below the upper limit, side reactions tend to be suppressed and the amount of contamination in the product tends to be reduced. From a similar viewpoint, the amount of base with a pKa of 9 or higher is preferably 0.5 to 5 molar equivalents, and more preferably 1 to 3 molar equivalents, per molar equivalent of polymerizable compound (2-b). Also from a similar viewpoint, the amount of base with a pKa of 9 or higher is preferably 1 to 8 molar equivalents, more preferably 1.5 to 5 molar equivalents, and even more preferably 1.5 to 3 molar equivalents, per molar equivalent of (meth)acrylate halide (3-a).

[0043] (organic solvent) The method for producing siloxane-modified liquid crystal polymers may be carried out in the presence of an organic solvent, and is preferably carried out in the presence of an organic solvent. Examples of organic solvents include amide solvents such as dimethylformamide (DMF), dimethylacetamide, and N-methylpyrrolidone (NMP); ether solvents such as tetrahydrofuran and diethyl ether; and halogen solvents such as chloroform and dichloromethane.

[0044] (Operating Procedure) The operating procedure for the manufacturing method of this embodiment is not particularly limited, but from the viewpoint of suppressing side reactions and sufficiently introducing the structural unit (3), it is preferable to carry it out in the following procedure. First, two mixtures are prepared: Mixture A, which contains siloxanediol (1-a) and a polymerizable compound (2-a) in an organic solvent, and Mixture B, which contains a polymerizable compound (2-b) and (meth)acrylate halide (3-a) in an organic solvent. Next, add (preferably dropwise) mixture B to the obtained mixture A, and stir well to prepare mixture AB. Subsequently, by adding a base with a pKa of 9 or higher while stirring the mixture AB, a siloxane-modified liquid crystal polymer can be obtained.

[0045] The manufacturing method of this embodiment can be carried out, for example, at 5 to 40°C. No heating is particularly necessary, and it can be carried out at room temperature. However, since the mixture may generate heat when a base with a pKa of 9 or higher is added to the mixture AB, it is preferable to add the base with a pKa of 9 or higher slowly to prevent the mixture AB from generating too much heat, and a dropwise method over time is more preferable. The rate at which the base with a pKa of 9 or higher is added to the mixture AB can be adjusted as appropriate while checking the degree of heat generation. Furthermore, to prevent the mixture AB from generating too much heat, it is also effective to add the base with a pKa of 9 or higher in two or more stages (for example, 2 to 4 times) (preferably dropwise).

[0046] (Post-processing) After adding a base with a pKa of 9 or higher and stirring thoroughly to allow the reaction to proceed, the polymerizable compound (2-b) and (meth)acrylate halide (3-a) can be deactivated and the polymerization reaction stopped by mixing with an alcohol-based solvent such as methanol, ethanol, or isopropyl alcohol, or a mixed solution of these alcohol-based solvents and water, as needed, and the product can be precipitated. After the product has precipitated, the product can be obtained by separation methods such as filtration, and the siloxane-modified liquid crystal polymer of this embodiment can be obtained by washing with an alcohol-based solvent such as methanol, ethanol, or isopropyl alcohol, as needed. The purity of the obtained siloxane-modified liquid crystal polymer may be increased as needed by known purification methods such as reprecipitation or recrystallization. Specific examples of reprecipitation or recrystallization methods include dissolving the obtained siloxane-modified liquid crystal polymer again in the organic solvent and then diluting it with an alcohol-based solvent or a mixed solution of these alcohol-based solvents and water.

[0047] [Thermosetting resin composition] The thermosetting resin composition of this embodiment is a thermosetting resin composition containing the siloxane-modified liquid crystal polymer of this embodiment. In the thermosetting resin composition of this embodiment, there are no particular restrictions on the content of the siloxane-modified liquid crystal polymer of this embodiment, but from the viewpoint of reducing transmission loss, it is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, and particularly preferably 20% by mass or more. There are no particular restrictions on the upper limit of the content of the siloxane-modified liquid crystal polymer of this embodiment, and it may be 100% by mass or less, 90% by mass or less, 80% by mass or less, or 70% by mass or less. In other words, the content of the siloxane-modified liquid crystal polymer of this embodiment may be 1 to 100% by mass. The thermosetting resin composition of this embodiment may contain components other than the siloxane-modified liquid crystal polymer of this embodiment. Components other than the siloxane-modified liquid crystal polymer of this embodiment are not particularly limited, but include: (1) thermosetting resins other than the siloxane-modified liquid crystal polymer of this embodiment, (2) curing agents, (3) curing accelerators, (4) inorganic fillers, (5) organic fillers, (6) flame retardants, (7) flame retardant aids, (8) thermoplastic resins, (9) thermoplastic elastomers, (10) ultraviolet absorbers, (11) antioxidants, (12) photopolymerization initiators, (13) fluorescent whitening agents, (14) adhesion enhancers, (15) flow regulators, (16) anti-repellent agents, (17) coupling agents, (18) heat stabilizers, (19) antistatic agents, (20) pigments, (21) colorants, (22) lubricants, (23) organic solvents, etc. Any known components can be used. The components other than the siloxane-modified liquid crystal polymer in this embodiment may be used individually or in combination of two or more.

[0048] [Metal foil with resin coating] The resin-coated metal foil of this embodiment has a layer of the thermosetting resin composition of this embodiment on the metal foil. Hereinafter, the "layer of thermosetting resin composition" may be referred to as the "resin layer". The resin-coated metal foil can be manufactured, for example, by coating the thermosetting resin composition of this embodiment onto the metal foil and then B-stage the thermosetting resin composition in a drying oven, thereby producing a "resin-coated metal foil" having a resin layer on the metal foil. Here, in this specification, B-stage refers to reaching the B-stage state as defined in JIS K6900 (1994), and is also called semi-curing. The drying conditions are not particularly limited, but the drying temperature is preferably 80 to 180°C, more preferably 110 to 160°C. There are no particular restrictions on the coating method, and known coating machines such as die coaters, comma coaters, bar coaters, kiss coaters, and roll coaters can be used. Examples of metal foils used in resin-coated metal foils include copper foil, aluminum foil, tin foil, tin-lead alloy (solder) foil, and nickel foil, but other metal foils can also be used. Among these, copper foil is preferred. When using copper foil as the metal foil, the grade and thickness of the copper foil should be appropriately selected according to the circuit design of the semiconductor package to be manufactured, but it is preferable that the copper foil has a copper content of 95% by mass or more. Of the two surfaces of the metal foil, the surface facing the resin layer may be roughened for better adhesion. This roughening treatment can be performed by forming roughening particles on the surface of the metal foil. The roughening particles are preferably electrodeposited particles consisting of at least one element selected from the group consisting of copper, nickel, phosphorus, tungsten, arsenic, molybdenum, chromium, cobalt, and zinc, or electrodeposited particles consisting of an alloy containing one or more of these elements. Furthermore, after roughening treatment, secondary particles, tertiary particles, a rust-preventive layer, or a heat-resistant layer may be formed using at least one element selected from the group consisting of nickel, cobalt, copper, and zinc, or an alloy containing one or more of these elements, and the surface may be further subjected to surface treatments such as chromate treatment or silane coupling treatment. In the resin-coated metal foil of this embodiment, the thickness of the resin layer is not particularly limited, but is preferably 5 to 200 μm, more preferably 10 to 100 μm, and even more preferably 10 to 50 μm. In the resin-coated metal foil of this embodiment, the thickness of the metal foil is not particularly limited, but is preferably 3 to 20 μm, more preferably 5 to 15 μm, and even more preferably 10 to 15 μm.

[0049] [Prepreg] The prepreg of this embodiment comprises the thermosetting resin composition of this embodiment and a sheet-like fiber-reinforced substrate. The prepreg can be formed using the thermosetting resin composition of this embodiment and a sheet-like fiber-reinforced substrate. For example, the prepreg of this embodiment can be produced by impregnating or coating the sheet-like fiber-reinforced substrate with the thermosetting resin composition of this embodiment, heating and drying it in a drying oven at a temperature of 80 to 200°C for 1 to 30 minutes, and bringing the thermosetting resin composition to the B stage. The solid content derived from the thermosetting resin composition in the prepreg of this embodiment is not particularly limited, but is preferably 30 to 90% by mass, more preferably 35 to 80% by mass, even more preferably 40 to 70% by mass, and particularly preferably 45 to 60% by mass. When the solid content derived from the thermosetting resin composition in the prepreg is within the above range, better moldability tends to be obtained when it is made into a laminate.

[0050] As the sheet-like fiber-reinforced substrate for the prepreg, known materials used in laminates for various electrical insulating materials can be used. Examples of materials for the sheet-like fiber-reinforced substrate include inorganic fibers such as E-glass, D-glass, S-glass, and Q-glass; organic fibers such as polyimide, polyester, and tetrafluoroethylene; and mixtures thereof. These sheet-like fiber-reinforced substrates can be in the form of woven fabric, non-woven fabric, rawhide, chopped strand mat, or surfacing mat. Furthermore, the thickness of the sheet-like fiber-reinforced substrate is not particularly limited; for example, those with a thickness of 5 to 200 μm can be used. Additionally, from the viewpoint of impregnation of the thermosetting resin composition, heat resistance, moisture resistance, and processability when used as a laminate, materials that have been surface-treated with coupling agents or mechanically opened can be used.

[0051] The following hot-melt method or solvent method can be used as a method for impregnating or coating a sheet-like fiber-reinforced substrate with a thermosetting resin composition. The hot melt method involves (1) coating a coated paper with good release properties from the thermosetting resin composition with the thermosetting resin composition and then laminating it onto a sheet-like fiber-reinforced substrate, or (2) directly coating the sheet-like fiber-reinforced substrate with a die coater, without including an organic solvent in the thermosetting resin composition. On the other hand, the solvent method involves adding an organic solvent to a thermosetting resin composition, immersing a sheet-like fiber-reinforced substrate in the resulting thermosetting resin composition to impregnate the sheet-like fiber-reinforced substrate with the thermosetting resin composition, and then drying it.

[0052] The thickness of the prepreg in this embodiment is not particularly limited and may be 10 to 250 μm, 10 to 120 μm, or 10 to 70 μm.

[0053] [Laminated board] The laminate of this embodiment is a laminate containing (i) the resin-coated metal foil of this embodiment or (ii) the prepreg and metal foil of this embodiment. A laminate having metal foil is sometimes called a metal-clad laminate. The laminate of this embodiment can be obtained by heating and pressing one resin-coated metal foil of this embodiment, or by arranging two resin-coated metal foils so that the metal foil forms the outer layer, and then heating and pressing them. Alternatively, the laminate can be obtained by arranging metal foil on one or both sides of one prepreg of this embodiment, or by arranging metal foil on one or both sides of two or more prepregs of this embodiment stacked together, and then heating and pressing them. Another method for manufacturing a laminate is to layer the resin-coated metal foil of this embodiment onto one or both sides of the prepreg of this embodiment or another prepreg, with the resin side facing the prepreg, and then heat and pressurize it. In this case, one prepreg may be used, or two or more prepregs may be laminated together. When two or more prepregs are laminated together, different prepregs may be combined. The metal used for the metal foil is not particularly limited as long as it is used for electrical insulating material applications. However, from the viewpoint of conductivity, it may be copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, chromium, or an alloy containing one or more of these metal elements. Copper and aluminum are preferred, and copper is more preferred. From the viewpoint of productivity, the heating temperature during heat-pressure molding is preferably 185°C or higher, but may also be 200-300°C or 220-250°C. When the heating temperature is within the above range, good productivity tends to be obtained along with excellent dielectric properties and flame retardancy. The pressure and time during heat-pressure molding are not particularly limited, but for example, the pressure can be in the range of 0.2 to 10 MPa and the time in the range of 0.1 to 5 hours. Alternatively, the heat-pressure molding may be carried out by using a vacuum press or the like to maintain a vacuum state for 0.5 to 5 hours. Under these conditions, a sufficiently hardened laminate can be obtained.

[0054] [Multilayer printed circuit board] The multilayer printed circuit board of this embodiment comprises (i) the resin-coated metal foil of this embodiment, (ii) the prepreg of this embodiment, or (iii) the laminate of this embodiment. The multilayer printed circuit board of this embodiment can be manufactured by performing circuit formation processing such as drilling, metal plating, etching of the metal foil, etc., and multilayer bonding processing using the resin-coated metal foil of this embodiment, the prepreg of this embodiment, or the laminate of this embodiment, by known methods.

[0055] [Semiconductor Packages] The semiconductor package of this embodiment is formed by mounting semiconductor elements on a multilayer printed circuit board of this embodiment. The semiconductor package of this embodiment can be manufactured, for example, by mounting semiconductor elements such as semiconductor chips and memory at predetermined positions on the multilayer printed circuit board of this embodiment using known methods, and then sealing the semiconductor elements with a sealing resin or the like.

[0056] Although preferred embodiments of this embodiment have been described above, these are merely examples for the purpose of explaining this embodiment, and are not intended to limit the scope of this embodiment to the embodiments described above. This embodiment can be implemented in various forms different from the embodiments described above without departing from its spirit. [Examples]

[0057] The embodiment will be described in detail below with reference to examples. However, this embodiment is not limited to the following examples.

[0058] In each example, the weight-average molecular weight and number-average molecular weight were measured using the following procedure. (Method for measuring weight-average molecular weight and number-average molecular weight) The weight-average molecular weight and number-average molecular weight were calculated from a calibration curve using standard polystyrene by gel permeation chromatography (GPC). The calibration curve was approximated by a cubic equation using standard polystyrene: TSKstandard POLYSTYRENE (Type; A-2500, A-5000, F-20, F-80) [manufactured by Tosoh Corporation, trade name]. The GPC measurement conditions are shown below. Equipment: High-speed GPC equipment HLC-8320GPC Detector: UV-8320 ultraviolet absorption detector [manufactured by Tosoh Corporation] Columns: Guard column; "TSK Guardcolumn SuperHZ-L" + Column; "TSKgel SuperHZM-N + TSKgel SuperHZM-M" + "TSKgel SuperH-RC" (all manufactured by Tosoh Corporation, product names) Column sizes: 4.6 x 20 mm (guard column), 4.6 x 150 mm (column), 6.0 x 150 mm (reference column) Eluent: Tetrahydrofuran Sample concentration: 5 mg / 5 mL Injection volume: 20μL Flow rate: 0.35mL / min Measurement temperature: 40℃

[0059] Furthermore, in each example, the content of each structural unit is as follows: 1 ¹H NMR measurements were performed, and the integral values ​​(moles) of the peaks originating from each structural unit were converted to mass to determine the value. ( 1 H NMR measurement conditions) Equipment: Nuclear Magnetic Resonance Spectrometer "ECX400II" (manufactured by JEOL RESONANCE Co., Ltd.) Solvent: Deuterated chloroform (CDCl3) Frequency: 400MHz

[0060] [Example 1] In a 0.2 L reaction vessel equipped with a stirrer, 93.1 parts by mass of 4,4'-dihydroxybiphenyl, 776.2 parts by mass of bisphenol A, 54.9 parts by mass of siloxane polymer "KF-6001" (functional group equivalent 900, manufactured by Shin-Etsu Chemical Co., Ltd.), which has hydroxyl groups at its molecular ends (more specifically, both ends), and 3,700 parts by mass of NMP were charged at 25°C. To this, an NMP solution containing 649.7 parts by mass of isophthalic acid dichloride and 125.4 parts by mass of methacrylate chloride was added dropwise over 26 minutes at 25°C. After stirring the resulting mixture for 0.5 hours, 384.5 parts by mass of triethylamine (pKa=10.7) was added dropwise over 5 minutes, and stirring was continued for 60 minutes. At this point, it was confirmed that the mixture was exothermic upon the addition of triethylamine. Furthermore, 384.5 parts by mass of triethylamine were added dropwise over 5 minutes, and stirring was continued for 60 minutes. Then, 76.9 parts by mass of triethylamine were added dropwise over 2 minutes, and stirring was continued for 60 minutes. Subsequently, 4,000 parts by mass of NMP were added to dilute the mixture 1.5 times. Then, the reaction was terminated and the product precipitated by gradually adding 48,000 parts by mass of a mixed solvent of methanol and water (water:methanol = 1:3 (volume ratio)). The precipitate was then filtered to obtain a siloxane-modified liquid crystal polymer. The amounts of each raw material and reagent used are summarized in Table 2. The obtained siloxane-modified liquid crystal polymer was thoroughly washed with methanol, filtered, dried, and then used with CDCl3 as the solvent. 1 1H NMR measurements were performed. 1 By attributing the 1H NMR measurement results, it was confirmed that the siloxane-modified liquid crystal polymer contains all of the structural units derived from 4,4'-dihydroxybiphenyl, bisphenol A, siloxane polymer, isophthalic acid dichloride, and methacrylate chloride. The content of each structural unit is shown in Table 2. Also, 1Figure 1 shows the 1H NMR measurement results, and Figure 2 shows a magnified view of the 7.5–6.8 ppm range. In Figures 1 and 2, the same symbols (a)–(l) are assigned to the peaks corresponding to the protons assigned to each region.

[0061] [Example 2] In a 0.2 L reaction vessel equipped with a stirrer, 93.1 parts by mass of 4,4'-dihydroxybiphenyl, 776.2 parts by mass of bisphenol A, 54.9 parts by mass of siloxane polymer "KF-6001" (functional group equivalent 900) having hydroxyl groups at both ends, and 3,700 parts by mass of NMP were charged at 25°C. To this, an NMP solution containing 649.7 parts by mass of isophthalic acid dichloride and 125.4 parts by mass of methacrylate chloride was added dropwise at 25°C over 17 minutes. After stirring the resulting mixture for 0.5 hours, 423.0 parts by mass of triethylamine was added dropwise over 5 minutes, and stirring was continued for 60 minutes. At this point, it was confirmed that the mixture had been exothermic upon the addition of triethylamine. Furthermore, another 423.0 parts by mass of triethylamine was added dropwise over 5 minutes, and stirring was continued for 60 minutes. Subsequently, the reaction termination solution was diluted 1.5 times with NMP, and then gradually added to 48,000 parts by mass of a water-methanol mixture (water:methanol = 1:3 (volume ratio)) to terminate the reaction and precipitate the product. The precipitate was then filtered to obtain a siloxane-modified liquid crystal polymer. The amounts of each raw material and reagent used are summarized in Table 2. Furthermore, the siloxane-modified liquid crystal polymer obtained by the same method as in Example 1 was 1 1H NMR measurements were performed. 1 By attributing the 1H NMR measurement results, it was confirmed that the siloxane-modified liquid crystal polymer contains all of the structural units derived from 4,4'-dihydroxybiphenyl, bisphenol A, siloxane polymer, isophthalic acid dichloride, and methacrylate chloride. The content of each structural unit is shown in Table 2.

[0062] [Example 3] In Example 2, the same procedure was followed except that 17.3 parts by mass of hydrogenated bisphenol A was used instead of 776.2 parts by mass of bisphenol A to obtain a siloxane-modified liquid crystal polymer. The amounts of each raw material and reagent used, and the weight-average molecular weight and number-average molecular weight of the obtained siloxane-modified liquid crystal polymer are summarized in Table 2. Furthermore, the siloxane-modified liquid crystal polymer obtained by the same method as in Example 1 was 1 1H NMR measurements were performed. 1 By attributing the 1H NMR measurement results, it was confirmed that the siloxane-modified liquid crystal polymer contains all of the structural units derived from 4,4'-dihydroxybiphenyl, hydrogenated bisphenol A, siloxane polymer, isophthalic acid dichloride, and methacrylate chloride. However, due to the presence of numerous peaks, it was difficult to determine the content of each structural unit.

[0063] [Examples 4 and 5] In Example 2, the same procedure was followed except that the amount of each raw material used was changed as shown in Table 2, to obtain a siloxane-modified liquid crystal polymer. The amount of each raw material and reagent used, and the weight-average molecular weight and number-average molecular weight of the obtained siloxane-modified liquid crystal polymer are summarized in Table 2. Furthermore, the siloxane-modified liquid crystal polymer obtained by the same method as in Example 1 was 1 1H NMR measurements were performed. 1 By attributing the 1H NMR measurement results, it was confirmed that the siloxane-modified liquid crystal polymer contains all of the structural units derived from 4,4'-dihydroxybiphenyl, bisphenol A, siloxane polymer, isophthalic acid dichloride, and methacrylate chloride. The content of each structural unit is shown in Table 2.

[0064] [Examples 6-8] In Example 2, the same procedure was followed except that the amounts of each raw material and reagent used were changed as shown in Table 2, and the method of adding triethylamine was changed as follows, to obtain a siloxane-modified liquid crystal polymer. Triethylamine was added dropwise by adding 667.8 parts by mass over 5 minutes, stirring for 60 minutes, and then adding another 667.9 parts by mass over 5 minutes, stirring for another 60 minutes. Table 2 summarizes the amounts of each raw material and reagent used, as well as the weight-average molecular weight and number-average molecular weight of the obtained siloxane-modified liquid crystal polymer. Furthermore, the siloxane-modified liquid crystal polymer obtained by the same method as in Example 1 was 1 1H NMR measurements were performed. 1 By attributing the 1H NMR measurement results, it was confirmed that the siloxane-modified liquid crystal polymer contains all of the structural units derived from 4,4'-dihydroxybiphenyl, bisphenol A, siloxane polymer, isophthalic acid dichloride, and methacrylate chloride. The content of each structural unit is shown in Table 2.

[0065] [Example 9] In Example 6, the same procedure was followed except that the types and amounts of each raw material and the amount of reagent used were changed as shown in Table 2, to obtain a siloxane-modified liquid crystal polymer. The amounts of each raw material and reagent used are summarized in Table 2. Furthermore, the siloxane-modified liquid crystal polymer obtained by the same method as in Example 1 was 1 1H NMR measurements were performed. 1 By attributing the 1H NMR measurement results, it was confirmed that the siloxane-modified liquid crystal polymer contains all of the structural units derived from 4,4'-dihydroxybiphenyl, bisphenol A, siloxane polymer, isophthalic acid dichloride, and methacrylate chloride. The content of each structural unit is shown in Table 2.

[0066] [Comparative Example 1] In a 0.2 L reaction vessel equipped with a stirrer, 93.1 parts by mass of 4,4'-dihydroxybiphenyl, 776.2 parts by mass of bisphenol A, 54.9 parts by mass of siloxane polymer "KF-6001" (functional group equivalent 900) having hydroxyl groups at both ends, 3.2 parts by mass of pyridine (pKa=5.3), and 3,700 parts by mass of NMP were charged at 25°C. To this, an NMP solution containing 649.7 parts by mass of isophthalic acid dichloride and 125.4 parts by mass of methacrylate chloride was added dropwise over 61 minutes at 25°C. After stirring the resulting mixture for 0.5 hours, 299.0 parts by mass of pyridine was added dropwise over 5 minutes, and stirring was continued for 30 minutes. At this time, it was confirmed that the mixture was exothermic upon the addition of pyridine. Furthermore, another 299.0 parts by mass of pyridine was added dropwise over 5 minutes, and stirring was continued for 80 minutes. Subsequently, the reaction was terminated by gradually adding 39,000 parts by mass of methanol to this reaction solution, and the product was precipitated. The precipitate was then filtered to obtain a siloxane-modified liquid crystal polymer. The amounts of each raw material and reagent used are summarized in Table 2. Regarding the obtained siloxane-modified liquid crystal polymer 1 ¹H NMR measurements revealed that the siloxane-modified liquid crystal polymer possessed structural units derived from 4,4'-dihydroxybiphenyl, bisphenol A, siloxane polymer, and isophthalic acid dichloride, but lacked structural units derived from methacrylate chloride. Furthermore, peaks believed to be side reaction products were observed. When pyridine with a pKa of 5.3 was used, the side reaction of methacrylate chloride became dominant, making it difficult to incorporate methacrylate chloride into the siloxane-modified liquid crystal polymer. Furthermore, there is a large amount of insoluble matter in CDCl3. 1 Calculating the content of each structural unit using 1H NMR measurements proved difficult.

[0067] <Evaluation of solubility> The solubility of the siloxane-modified liquid crystal polymers obtained in the above examples and comparative examples in organic solvents was investigated. 0.05 g of the siloxane-modified liquid crystal polymer obtained in each example and 1.0 ml of one of the organic solvents listed in Table 2 were placed in a test tube. The resulting mixture was shaken well and then allowed to stand. Solubility was evaluated according to the evaluation criteria below. The results are shown in Table 2. A: The mixture is transparent and exhibits excellent solubility for siloxane-modified liquid crystal polymers. B: The mixture is semi-transparent, and the siloxane-modified liquid crystal polymer is slightly dissolved. C: At least one of agglomeration and sedimentation occurs in the mixture, indicating low solubility of the siloxane-modified liquid crystal polymer.

[0068] [Table 2]

[0069] (Explanation of abbreviations in Table 2) KF-6001: A siloxane polymer "KF-6001" having hydroxyl groups at both ends of the molecule (functional group equivalent 900, manufactured by Shin-Etsu Chemical Co., Ltd.) DHB: 4,4'-dihydroxybiphenyl BPA: Bisphenol A Hydrogenated BPA: 2,2-bis(4-hydroxycyclohexyl)propane BPF: Bisphenol F IPC: Isophthalate Dichloride MC: Methacrylate Chloride

[0070] Table 2 shows that the siloxane-modified liquid crystal polymer of this embodiment has improved solubility in organic solvents. Liquid crystal polymers that are expected to reduce transmission loss in substrate materials generally have poor solubility in organic solvents, but the siloxane-modified liquid crystal polymer of this embodiment, with its improved solubility in organic solvents, shows promise as a novel substrate material. Furthermore, by using the siloxane-modified liquid crystal polymer of this embodiment, it is also expected that the low thermal expansion properties of the substrate material will be improved. [Industrial applicability]

[0071] The siloxane-modified liquid crystal polymer of this embodiment provides a novel substrate material. Thermosetting resin compositions containing this siloxane-modified liquid crystal polymer are suitable for applications involving electronic components that handle high-frequency signals, such as resin-coated metal foils, prepregs, laminates, multilayer printed circuit boards, and semiconductor packages.

Claims

1. A siloxane-modified liquid crystal polymer having a structural unit (1) derived from a siloxane polymer, a structural unit (2) derived from a liquid crystal polymer, and a structural unit (3) having an ethylenically unsaturated bond-containing group, wherein the siloxane-modified liquid crystal polymer contains a structural unit (3) having an ethylenically unsaturated bond-containing group at its molecular terminus, and the cured product of a thermosetting resin composition.

2. A cured product of the thermosetting resin composition according to claim 1, wherein the content of the structural unit (1) in the siloxane-modified liquid crystal polymer is 0.1 to 35% by mass.

3. A cured product of the thermosetting resin composition according to claim 1 or 2, wherein the content of the structural unit (2) in the siloxane-modified liquid crystal polymer is 10 to 98% by mass.

4. A cured product of a thermosetting resin composition according to any one of claims 1 to 3, wherein the liquid crystal polymer constituting the structural unit (2) has a structural unit derived from one or more polymerizable compounds selected from the group consisting of aromatic hydroxycarboxylic acid, aromatic hydroxycarboxylic acid acylate, aromatic hydroxycarboxylic acid ester, aromatic hydroxycarboxylic acid halide, aromatic dicarboxylic acid, aromatic dicarboxylic acid ester, aromatic dicarboxylic acid dihalide, aromatic diol, aromatic diol acylate, aromatic aminocarboxylic acid, aromatic aminocarboxylic acid acylate, aromatic aminocarboxylic acid halide, aromatic hydroxyamine, aromatic hydroxyamine acylate, aromatic diamine, aromatic diamine acylate, aliphatic diol, aliphatic diol acylate, aliphatic dicarboxylic acid, aliphatic dicarboxylic acid ester, and aliphatic dicarboxylic acid dihalide.

5. A cured product of a thermosetting resin composition according to any one of claims 1 to 4, wherein the ethylenically unsaturated bond-containing group is one or more selected from the group consisting of an unsaturated aliphatic hydrocarbon group (3-i) and a group containing a heteroatom and an ethylenically unsaturated bond (3-ii).

6. A cured product of a thermosetting resin composition according to any one of claims 1 to 5, wherein the ethylenically unsaturated bond-containing group is a (meth)acryloyl group.

7. A cured product of a thermosetting resin composition according to any one of claims 1 to 6, wherein the thermosetting resin composition contains one or more selected from the group consisting of (1) a thermosetting resin other than the siloxane-modified liquid crystal polymer, (2) a curing agent, (3) a curing accelerator, (4) an inorganic filler, (5) an organic filler, (6) a flame retardant, (7) a flame retardant aid, (8) a thermoplastic resin, (9) a thermoplastic elastomer, (10) an ultraviolet absorber, (11) an antioxidant, (12) a photopolymerization initiator, (13) a fluorescent whitening agent, (14) an adhesion enhancer, (15) a flow modifier, (16) an anti-repellent agent, (17) a coupling agent, (18) a heat stabilizer, (19) an antistatic agent, (20) a pigment, (21) a colorant, and (22) a lubricant.

8. A cured product of a thermosetting resin composition according to any one of claims 1 to 7, wherein the content of siloxane-modified liquid crystal polymer is 1% by mass or more.

9. A laminate comprising a cured product of the thermosetting resin composition according to any one of claims 1 to 8.

10. A multilayer printed circuit board comprising a cured product of the thermosetting resin composition according to any one of claims 1 to 8.

11. A semiconductor package comprising a cured product of a thermosetting resin composition according to any one of claims 1 to 8 and a semiconductor element.

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