CURABLE COMPOSITION FOR FORMING INSULATING FILM, METHOD FOR FORMING INSULATING FILM, AND TERMINALLY MALEIMIDE-MODIFIED POLYPHENYLENE ETHER RESIN

Abstract

Provided are: a curable composition that is suitable for forming an insulating film, the curable composition having excellent film formation properties and making it possible to form a cured product that has a low dielectric constant and dielectric loss tangent but excellent heat resistance; an insulating film formation method that uses the curable composition; and a terminally maleimide-modified polyphenylene ether resin that is suitable as a component of the curable composition.　A curable composition that includes: a terminally maleimide-modified polyphenylene ether resin (A) that has, at a terminus of the molecular chain thereof, a radically polymerizable group that has a specific structure that includes a maleimide skeleton; and a radical generator (C).

Description

[Technical field]

[0001] The present invention relates to a curable composition used for forming an insulating film, a method for forming an insulating film, and a maleimide-terminated polyphenylene ether resin. [Background technology]

[0002] In recent years, communication devices such as mobile phones have become increasingly higher in frequency, which has led to a demand for insulating films that insulate the metal wiring in communication devices to be able to handle higher frequencies. Here, the higher the frequency, the greater the transmission loss, and the increased transmission loss attenuates the electrical signal. Therefore, in order to accommodate the increase in frequency, it is necessary to reduce the transmission loss.

[0003] In order to reduce transmission loss, a technique has been disclosed in which an insulating film is formed using a material with a low dielectric constant and a low dielectric loss tangent (eg, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2004-87639 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology of Patent Document 1 is a technology that uses a resin composition having a specific structure, specifically, a resin composition that contains a crosslinking component represented by formula (1) described in Patent Document 1. Under these circumstances, a technology that uses a composition other than the composition described in Patent Document 1 is desired. In addition, compatibility with higher frequencies is also being sought in electric and electronic devices other than communication equipment, such as network-related electronic equipment such as servers, and electronic equipment such as computers.

[0006] In addition, in the manufacture of electric and electronic devices, after an insulating film is formed from a composition, it is often heated to form wiring and other components, and therefore the insulating film is also required to have heat resistance. When forming an insulating film from a composition, the insulating film can be easily formed by a coating method, and therefore it is desirable that the composition be applicable to the coating method, i.e., have excellent film-forming properties in the coating method.

[0007] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a curable composition that can be suitably applied to the formation of an insulating film, capable of forming a cured product having a low dielectric constant and dielectric tangent and excellent heat resistance and having excellent film-forming properties; a method for forming an insulating film using the curable composition; and a maleimide-terminated polyphenylene ether resin that is suitably used as a component of the curable composition. [Means for solving the problem]

[0008] The present inventors have found that a curable composition containing a maleimide-terminated polyphenylene ether resin (A) having, at the molecular chain end, a radically polymerizable group of a specific structure containing a maleimide skeleton, gives an insulating film having a low dielectric constant and dielectric tangent and excellent heat resistance, and also has excellent film-forming properties, and have thus completed the present invention.

[0009] A first aspect of the present invention is a curable composition comprising a terminal maleimide-modified polyphenylene ether resin (A) and a radical generator (C), The maleimide-terminated polyphenylene ether resin (A) is represented by the following formula (a1): [ka] At the molecular chain end, In formula (a1), R a01 and R a02 each independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, a cycloalkyl group having from 3 to 8 carbon atoms, or an aryl group having from 6 to 12 carbon atoms, The phenylene group contained in the main chain of the maleimide-terminated polyphenylene ether resin (A) may have 1 to 4 substituents, The terminal group is represented by the following formula (a2): *-Y 2 -Y 1 -**···(a2) and is bonded to the main chain of the terminal maleimide-modified polyphenylene ether resin (A) via a linking group represented by the following formula: the bond on the ** side of the linking group is bonded to an oxygen atom derived from a hydroxyl group at the terminal of the molecular chain of the unmodified polyphenylene ether resin (A') which gives the terminally maleimide-modified polyphenylene ether resin (A), The bond on the * side of the linking group is bonded to the terminal group, In formula (a2), Y 1 is a single bond or a carbonyl group, Y 2 is a divalent organic group, and Y 1 is a single bond, Y 1 A single bond as Y 2 is bonded to a carbon atom having an sp3 hybrid orbital in a divalent organic group as This is a curable composition used for forming an insulating film.

[0010] A second aspect of the present invention is a curable composition comprising a terminal maleimide-modified polyphenylene ether resin (A) and a radical generator (C), The maleimide-terminated polyphenylene ether resin (A) is represented by the following formula (a1): [ka] At the molecular chain end, In formula (a1), R a01 and R a02 each independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, a cycloalkyl group having from 3 to 8 carbon atoms, or an aryl group having from 6 to 12 carbon atoms, The phenylene group contained in the main chain of the maleimide-terminated polyphenylene ether resin (A) may have 1 to 4 substituents, The curable composition is characterized in that the radical generator (C) is a photoradical generator (C1).

[0011] The third aspect of the present invention is a compound represented by the following formula (a1): [ka] At the molecular chain end, In formula (a1), R a01 and R a02 each independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, a cycloalkyl group having from 3 to 8 carbon atoms, or an aryl group having from 6 to 12 carbon atoms, The phenylene group contained in the main chain of the maleimide-terminated polyphenylene ether resin (A) may have 1 to 4 substituents, The terminal group is represented by the following formula (a2): *-Y 2 -Y 1 -**···(a2) and is bonded to the main chain of the terminal maleimide-modified polyphenylene ether resin (A) via a linking group represented by the following formula: the bond on the ** side of the linking group is bonded to an oxygen atom derived from a hydroxyl group at the terminal of the molecular chain of the unmodified polyphenylene ether resin (A') which gives the terminally maleimide-modified polyphenylene ether resin (A), The bond on the * side of the linking group is bonded to the terminal group, In formula (a2), Y 1 is a single bond or a carbonyl group, Y 2 is a divalent organic group, and Y 1 is a single bond, Y 1 A single bond as Y 2 It is a terminal maleimide-modified polyphenylene ether resin in which the aryl group is bonded to a carbon atom that takes an sp3 hybrid orbital in a divalent organic group as a aryl group. Effect of the Invention

[0012] According to the present invention, it is possible to provide a curable composition that can be suitably applied to the formation of an insulating film, capable of forming a cured product having a low dielectric constant and dielectric tangent and excellent heat resistance, and having excellent film-forming properties; a method for forming an insulating film using the curable composition; and a maleimide-terminated polyphenylene ether resin that is suitably used as a component of the curable composition. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a diagram showing the results of 1H NMR measurement of terminally maleimide-modified polyphenylene ether resin P1 obtained in Preparation Example 1 and an unmodified polyphenylene ether resin (SA90). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] ≪Curable composition≫ The curable composition includes a terminal maleimide-modified polyphenylene ether resin (A) and a radical generator (C); The maleimide-terminated polyphenylene ether resin (A) is represented by the following formula (a1): [ka] at the molecular chain end, In formula (a1), R a01 and R a02 are each independently a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, a cycloalkyl group having from 3 to 8 carbon atoms, or an aryl group having from 6 to 12 carbon atoms; The first curable composition and the second curable composition have, as a common feature, that the phenylene group contained in the main chain of the terminal maleimide-modified polyphenylene ether resin (A) may have 1 to 4 substituents. The first curable composition and the second curable composition will be described below.

[0015] <First curable composition> The first curable composition is a curable composition containing a terminal maleimide-modified polyphenylene ether resin (A) and a radical generator (C). As described above, the maleimide-terminated polyphenylene ether resin (A) is represented by the following formula (a1): [ka] At the end of the molecular chain, the polymer has a terminal group represented by the following formula: In formula (a1), R a01 and R a02 are each independently a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, a cycloalkyl group having from 3 to 8 carbon atoms, or an aryl group having from 6 to 12 carbon atoms. The phenylene group contained in the main chain of the maleimide-terminated polyphenylene ether resin (A) may have 1 to 4 substituents. In the terminal maleimide-modified polyphenylene ether resin used in the first curable composition, the terminal group is represented by the following formula (a2): *-Y 2 -Y 1 -**···(a2) The maleimide-terminated polyphenylene ether resin (A) is bonded to the main chain thereof via a linking group represented by the following formula: The bond on the ** side of the linking group bonds to an oxygen atom derived from a hydroxyl group at the molecular chain terminal of the unmodified polyphenylene ether resin (A') which gives the terminal maleimide-modified polyphenylene ether resin (A), while the bond on the * side of the linking group bonds to a terminal group. In formula (a2), Y 1 is a single bond or a carbonyl group. 2 is a divalent organic group. 1 is a single bond, Y 1 A single bond as Y 2 It bonds to a carbon atom that has an sp3 hybrid orbital in a divalent organic group.

[0016] The first curable composition is used for forming an insulating film. Typically, the first curable composition is used for forming an insulating film that insulates metal wiring in an electric or electronic device having metal wiring. The electric / electronic device is not particularly limited, but may be communication equipment such as mobile phones, network-related electronic devices such as servers, electronic devices such as computers, and in particular the semiconductor components contained in these devices, specifically semiconductor packages known as wafer-level packages. These electric / electronic devices have metal wiring made of a metal such as copper or an alloy on a substrate for the electric / electronic device. Examples of the substrate for the electric / electronic device having metal wiring include a silicon substrate and a substrate having various layers and members provided on a silicon substrate. This metal wiring is insulated from other metal wirings and conductive members by an insulating film formed from the first curable composition. By using the first curable composition containing the components described below, an insulating film having a low dielectric constant and dielectric tangent (tan δ) can be formed. Therefore, the first curable composition containing the components described below is suitable for an insulating film that insulates metal wiring of an electric / electronic device that uses high-frequency signals. In this specification, "high frequency" means a frequency of 3 GHz or more. Furthermore, since the first curable composition can form an insulating film with excellent heat resistance, it can be used, for example, to form an insulating film in an electric / electronic device in which an insulating film is formed from the curable composition and then other components are formed by heating. In addition, the first curable composition has excellent film-forming properties when applied to a coating method. That is, when applied to a coating method, no cracks or crystals occur, there is no tack (stickiness), and the compatibility of the components is good, so that an insulating film can be formed by the coating method, which is a simple method. The first curable composition will be described in detail below.

[0017] [Terminated maleimide-modified polyphenylene ether resin (A)] The first curable composition contains a maleimide-terminated polyphenylene ether resin (A) having a terminal group represented by the following formula (a1) at the molecular chain terminal. In the specification of the present application, the substituted or unsubstituted cyclic imide group represented by formula (a1) is also referred to as a "maleimide group" for convenience. [ka] (In formula (a1), R a01 and R a02 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, or an aryl group having 6 to 12 carbon atoms.

[0018] R in formula (a1) a01 and R a02 The alkyl group having 1 to 6 carbon atoms as the alkyl group may be a linear or branched alkyl group. Specific examples include a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, an n-hexyl group, an isopropyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a tert-pentyl group, and an isohexyl group. R in formula (a1) a01 and R a02 Specific examples of the cycloalkyl group having 3 to 8 carbon atoms as the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group. R in formula (a1) a01 and R a02 Specific examples of the aryl group having 6 to 12 carbon atoms as the aryl group include a phenyl group, a biphenyl group, a 1-naphthyl group, and a 2-naphthyl group. R in formula (a1) a01 and R a02 R is preferably a hydrogen atom. a01 and R a02 When R are all hydrogen atoms, the maleimide-terminated polyphenylene ether resin (A) has excellent polymerizability. Therefore, it is easy to obtain a first curable composition having excellent curability. a01and R a02 When both are hydrogen atoms, the group represented by formula (a1) becomes an unsubstituted maleimide group.

[0019] The terminal group represented by formula (a1) is represented by the following formula (a2): *-Y 2 -Y 1 -**···(a2) The maleimide-terminated polyphenylene ether resin (A) is bonded to the main chain thereof via a linking group represented by the following formula:

[0020] The bond on the ** side in the above linking group bonds to an oxygen atom derived from a hydroxyl group at the molecular chain terminal of the unmodified polyphenylene ether resin (A') which gives the terminally maleimide-modified polyphenylene ether resin (A), while the bond on the * side in the linking group bonds to the terminal group represented by formula (a1).

[0021] In formula (a2), Y 1 is a single bond or a carbonyl group. 2 is a divalent organic group. 1 is a single bond, Y 1 A single bond as Y 2 It bonds to a carbon atom that has an sp3 hybrid orbital in a divalent organic group.

[0022] In formula (a2), Y 1 When Y is a carbonyl group, 2 But -Y 4 -Y 3 It is preferable that Y is a group represented by the formula: 3 is a single bond, -O-, or -NH-. 4 is a divalent organic group. Y 3 Y 1 It bonds with a carbonyl group as an aryl group. That is, Y in formula (a2) 1 When is a carbonyl group, the linking group represented by formula (a2) is preferably a group represented by the following formulas (a2-1) to (a2-3). *-Y 4 -CO-**···(a2-1) *-Y4 -O-CO-**···(a2-2) *-Y 4 -NH-CO-**···(a2-3)

[0023] Y 4 The divalent organic group as Y 3 There is no particular limitation as long as it is a group capable of linking the terminal group represented by formula (a1) to the terminal group represented by formula (a2). The structure of the organic group may be linear, branched, cyclic, or a combination of these structures. Examples of heteroatoms other than carbon atoms and hydrogen atoms that the organic group may contain include nitrogen atoms, sulfur atoms, oxygen atoms, halogen atoms, phosphorus atoms, silicon atoms, and boron atoms. The organic group may have one or more unsaturated bonds. Y 4 As the terminal group, a hydrocarbon group is preferred because the compound used for terminal modification in the terminally maleimide-modified polyphenylene ether resin (A) is easily available or produced, and the desired terminal modification is easily achieved. The hydrocarbon group preferably has 1 or more and 10 or less carbon atoms, more preferably 1 or more and 8 or less carbon atoms, and even more preferably 1 or more and 6 or less carbon atoms. The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, with aliphatic hydrocarbon groups being preferred as the hydrocarbon group because they are more flexible than rigid aromatic hydrocarbon groups.

[0024] Y 4Preferred hydrocarbon groups include a methylene group, an ethane-1,2-diyl group, an ethane-1,1-diyl group, a propane-1,3-diyl group, a propane-1,2-diyl group, a propane-1,1-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, a cyclohexane-1,4-diyl group, a cyclohexane-1,3-diyl group, a cyclohexane-1,2-diyl group, a p-phenylene group, an m-phenylene group, an o-phenylene group, a naphthalene-1,4-diyl group, a naphthalene-2,6-diyl group, and a naphthalene-2,7-diyl group. Of these, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, cyclohexane-1,4-diyl, and cyclohexane-1,3-diyl are preferred.

[0025] In formula (a2), Y 1 is a single bond, Y 1 A single bond as Y 2 The sp3 hybridized carbon atom in the divalent organic group is typically Y 2 In the organic group as described above, the carbon atom constituting the entire structure or partial structure of an aliphatic hydrocarbon group is a carbon atom.

[0026] In formula (a2), Y 1 is a single bond, Y 2 The divalent organic group as Y is not particularly limited as long as it has at least one carbon atom having an sp3 hybrid orbital and is capable of linking an oxygen atom derived from a hydroxyl group at the molecular chain terminal of the unmodified polyphenylene ether resin (A') which gives the terminally maleimide-modified polyphenylene ether resin (A) to the terminal group represented by formula (a1). 1 When Y is a single bond, 2 The divalent organic group as may contain, in addition to carbon and hydrogen atoms, one or more heteroatoms such as nitrogen atoms, sulfur atoms, oxygen atoms, halogen atoms, phosphorus atoms, silicon atoms, and boron atoms.

[0027] Y 1 is a single bond, Y 2 The divalent organic group as the carbon atom number is preferably 1 or more and 10 or less, more preferably 1 or more and 8 or less, and even more preferably 1 or more and 6 or less.

[0028] Y 1 is a single bond, Y 2 The divalent organic group as is preferably an aliphatic hydrocarbon group in which one or more methylene groups may be substituted with a carbonyl group (-CO-), an ether bond (-O-), or an imino group (-NH-). Y 1 is a single bond, Y 2 Examples of the aliphatic hydrocarbon group that is preferred as the aryl group include a methylene group, an ethane-1,2-diyl group, an ethane-1,1-diyl group, a propane-1,3-diyl group, a propane-1,2-diyl group, a propane-1,1-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, a cyclohexane-1,4-diyl group, a cyclohexane-1,3-diyl group, and a cyclohexane-1,2-diyl group. In addition, groups in which one or two methylene groups of these hydrocarbon groups are substituted with a carbonyl group (-CO-), an ether bond (-O-), or an imino group (-NH-) are also preferred. Of these, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, cyclohexane-1,4-diyl, and cyclohexane-1,3-diyl are preferred.

[0029] There are no particular limitations on the method for modifying the unmodified polyphenylene ether resin (A') by introducing the terminal group represented by formula (a1) into the molecular chain terminal. In order to carry out such modification, an unmodified polyphenylene ether resin (A') having a phenolic hydroxyl group terminal is preferably used.

[0030] The unmodified polyphenylene ether resin (A') may be a resin having at least one phenolic hydroxyl group terminal. The unmodified polyphenylene ether resin (A') preferably has two or more phenolic hydroxyl group terminals, more preferably has two or three phenolic hydroxyl group terminals, and further preferably has two phenolic hydroxyl group terminals. When the unmodified polyphenylene ether resin (A') has a terminal phenolic hydroxyl group, the unmodified polyphenylene ether resin (A') may further have a phenolic hydroxyl group on the phenylene group contained in the main chain.

[0031] The polyphenylene ether resin can typically be produced by oxidatively polymerizing a phenolic compound such as 2,6-dimethylphenol in the presence of a catalyst containing a metal such as copper. The method for producing the unmodified polyphenylene ether resin (A') is not particularly limited, but it is preferable that the unmodified polyphenylene ether resin (A') is produced according to a known method, such as the typical method described above.

[0032] The phenylene group contained in the main chain of the terminally maleimide-modified polyphenylene ether resin (A) may have 1 to 4 substituents. Therefore, the phenylene group contained in the main chain of the unmodified polyphenylene ether resin (A') may also have 1 to 4 substituents. Preferred examples of the substituent include alkyl groups having 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group; aromatic hydrocarbon groups, such as a phenyl group, an o-tolyl group, an m-tolyl group, and a p-tolyl group; alkoxy groups having 1 to 4 carbon atoms, such as a methoxy group, an ethoxy group, an n-propyloxy group, an isopropyloxy group, an n-butyloxy group, an isobutyloxy group, a sec-butyloxy group, and a tert-butyloxy group; a phenolic hydroxyl group; and halogen atoms, such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among these substituents, a methyl group, a phenyl group, a chlorine atom, and a bromine atom are preferred, and a methyl group, a phenyl group, and a chlorine atom are more preferred.

[0033] The unmodified polyphenylene ether resin (A') may be a homopolymer of a phenol, or a copolymer of two or more kinds of phenols. The unmodified polyphenylene ether resin (A') may be a polymer obtained by polymerizing only a monohydric phenol, or may be a polymer obtained by copolymerizing a monohydric phenol with a polyhydric phenol such as a dihydric phenol or a trihydric phenol. A polymer containing only a monohydric phenol has an aryl group having no hydroxyl group derived from the starting phenol at one end, and a hydroxyaryl group derived from the starting phenol at the other end.

[0034] In the copolymer of monohydric phenol and polyhydric phenol, the molecular chain of polyphenylene ether grows from two or more phenolic hydroxyl groups of the polyhydric phenol. Therefore, when a dihydric phenol is copolymerized with a monohydric phenol, a polyphenylene ether resin having hydroxyaryl groups at both ends is obtained. Also, when a trihydric or higher phenol is copolymerized with a monohydric phenol, a polyphenylene ether resin having branched chains corresponding to the valence of the polyhydric phenol and each branched chain has a hydroxyaryl group at its end is obtained.

[0035] Specific examples of homopolymers of phenols include poly(2,6-dimethyl-1,4-phenylene ether), poly(2-methyl-6-phenyl-1,4-phenylene ether), poly(2,6-dichloro-1,4-phenylene ether), and the like. As described above, the copolymer of two or more phenols may be a copolymer of two or more monohydric phenols, or a copolymer of one or more monohydric phenols and one or more dihydric phenols. Specific examples of copolymers of two or more monohydric phenols include a copolymer of 2,6-dimethylphenol and 2,3,6-trimethylphenol, a copolymer of 2,6-dimethylphenol and 2,6-dichlorophenol, and a copolymer of 2,6-dimethylphenol and 2-methyl-6-phenylphenol. Examples of copolymers of one or more monohydric phenols and one or more dihydric phenols include a copolymer in which 3,3',5,5'-tetramethylbisphenol A is polymerized with 2,6-dimethylphenol, a copolymer in which 3,3',5,5'-tetramethylbisphenol A is polymerized with 2-methyl-6-phenylphenol, and a copolymer in which 3,3',5,5'-tetramethylbisphenol A is polymerized with 2,6-dichlorophenol.

[0036] The unmodified polyphenylene ether resin (A') is preferably a copolymer of a monohydric phenol and a dihydric phenol, such as a copolymer in which 3,3',5,5'-tetramethylbisphenol A is polymerized with 2,6-dimethylphenol, a copolymer in which 3,3',5,5'-tetramethylbisphenol A is polymerized with 2-methyl-6-phenylphenol, or a copolymer in which 3,3',5,5'-tetramethylbisphenol A is polymerized with 2,6-dichlorophenol, and more preferably a copolymer in which 3,3',5,5'-tetramethylbisphenol A is polymerized with 2,6-dimethylphenol.

[0037] There is no particular limitation on the method for modifying the unmodified polyphenylene ether resin (A') to introduce the terminal group represented by formula (a1) at the terminal. For example, in formula (a2), Y 1 is a carbonyl group, and the linking group represented by formula (a2) is the following formula (a2-1): *-Y 4 -CO-**···(a2-1) When MIG-Y is a group represented by 4A carboxylic acid represented by -CO-OH is condensed with a phenolic hydroxyl group of the unmodified polyphenylene ether resin (A') using a condensing agent such as a carbodiimide compound such as carbonyldiimidazole or N,N'-diisopropylcarbodiimide, thereby converting the terminal phenolic hydroxyl group of the unmodified polyphenylene ether resin (A') into a terminal phenolic hydroxyl group of the unmodified polyphenylene ether resin (A') represented by -O-CO-Y 4 It can be converted to a group represented by —MIG, where MIG is a terminal group represented by formula (a1). Also, MIG-Y 4 By reacting a carboxylic acid halide represented by -CO-Hal with a phenolic hydroxyl group of the unmodified polyphenylene ether resin (A'), the terminal phenolic hydroxyl group of the unmodified polyphenylene ether resin (A') is converted to a terminal phenolic hydroxyl group of the unmodified polyphenylene ether resin (A') represented by -O-CO-Y 4 -MIG, where Hal is a halogen atom such as a chlorine atom or a bromine atom.

[0038] In formula (a2), Y 1 is a carbonyl group, and the linking group represented by formula (a2) is the following formula (a2-2): *-Y 4 -O-CO-**···(a2-2) In the case where the unmodified polyphenylene ether resin (A') has a phenolic hydroxyl group and an excess amount of MIG-Y relative to the phenolic hydroxyl group, 4 By reacting an alcohol represented by -OH with a compound that generates a carbonate bond, such as phosgene or triphosgene, the terminal phenolic hydroxyl group of the unmodified polyphenylene ether resin (A') is converted to -O-CO-OY 4 It can be converted to a group represented by -MIG.

[0039] In formula (a2), Y 1 is a carbonyl group, and the linking group represented by formula (a2-3) is the following formula (a2-3): *-Y 4 -NH-CO-**···(a2-3) In the case where the unmodified polyphenylene ether resin (A') is a group represented by the formula: 4 By reacting the unmodified polyphenylene ether resin (A') with an isocyanate represented by -NCO, the terminal phenolic hydroxyl group of the unmodified polyphenylene ether resin (A') is converted to an isocyanate represented by -O-CO-NH-Y 4 It can be converted to a group represented by -MIG.

[0040] In formula (a2), Y 1 When is a single bond, the phenolic hydroxyl group of the unmodified polyphenylene ether resin (A') and MIG-Y 2 The terminal phenolic hydroxyl group of the unmodified polyphenylene ether resin (A') is converted to a halide represented by -OY by etherification with a halide represented by -Hal by a method such as the so-called Williamson ether synthesis. 2 It can be converted to a group represented by -MIG.

[0041] Representative methods for modifying the phenolic hydroxyl group have been described above, but the method for modifying the phenolic hydroxyl group is not limited to these methods. As a method for modifying the phenolic hydroxyl group, various known methods can be used depending on the structure of the linking group bonded to the terminal group represented by formula (a1). In the above modification method, an organic solvent may be used as appropriate depending on the reaction employed, if necessary. Regarding the reaction temperature and reaction time, suitable known conditions for the reaction employed may be used as appropriate.

[0042] When preparing the maleimide-terminated polyphenylene ether resin (A) using the unmodified polyphenylene ether resin (A'), a group containing a terminal group represented by formula (a1) may be introduced into some of the phenolic hydroxyl groups of the unmodified polyphenylene ether resin (A'), or a group containing a terminal group represented by formula (a1) may be introduced into all of the phenolic hydroxyl groups.

[0043] The molecular weight of the terminal maleimide-modified polyphenylene ether resin (A) is not particularly limited as long as it does not impair the effects of the present invention. The mass average molecular weight (Mw) is preferably 2000 or more, more preferably 2500 or more, and even more preferably 3000 or more. The molecular weight of the resin (A) is preferably 100,000 or less, more preferably 80,000 or less, even more preferably 50,000 or less, and even more preferably 10,000 or less, as the mass average molecular weight (Mw). In this specification, the mass average molecular weight (Mw) is a value measured by gel permeation chromatography (GPC) in terms of polystyrene.

[0044] In this way, the terminal maleimide-modified polyphenylene ether resin (A) having the terminal group represented by formula (a1) at a specific position can be polymerized by exposure to light or heating because the terminal group represented by formula (a1) is a radically polymerizable group. As a result of the polymerization, the terminal maleimide-modified polyphenylene ether resin (A) gives an insulating film having a low dielectric constant, a low dielectric loss tangent, and excellent heat resistance. For example, the dielectric constant of the insulating film formed can be made less than 3.00. Also, the dielectric loss tangent of the insulating film formed can be made less than 0.01. Also, the glass transition temperature (Tg) of the insulating film formed can be made 150° C. or higher. The first curable composition containing the terminal maleimide-modified polyphenylene ether resin (A) has excellent film-forming properties in a coating method. Therefore, when a film is formed by a coating method using such a curable composition, cracks and crystals do not occur, there is no tack (stickiness), and the compatibility of the components is good. Therefore, an insulating film can be formed by a coating method, which is a simple method.

[0045] The maleimide-terminated polyphenylene ether resin (A) has excellent solubility in a solvent, and therefore the first curable composition containing the maleimide-terminated polyphenylene ether resin (A) is applicable to a development process using the solvent as a negative composition. In particular, the terminal maleimide-modified polyphenylene ether resin (A) may be soluble in an alkaline aqueous solution, depending on its structure. For example, the terminal maleimide-modified polyphenylene ether resin (A) may have an alkali-soluble group such as a carboxy group or a phenolic hydroxyl group. The first curable composition containing such an alkali-soluble terminal maleimide-modified polyphenylene ether resin (A) is applicable to an alkaline development process as a negative composition. By subjecting a coating film made of the first curable composition containing the terminal maleimide-modified polyphenylene ether resin (A) to site-selective exposure and the above-mentioned development process, an insulating film having a desired pattern shape can be formed.

[0046] The content of the terminal maleimide-modified polyphenylene ether resin (A) in the first curable composition is not particularly limited. The content of the terminal maleimide-modified polyphenylene ether resin (A) is preferably 5% by mass or more and 100% by mass or less based on the total solid content of the first curable composition.

[0047] [Radically polymerizable compound (B)] The first curable composition may further contain a radically polymerizable compound (B). Of course, the first curable composition does not have to contain the radically polymerizable compound (B). The radically polymerizable compound (B) is a radically polymerizable compound other than the terminal maleimide-modified polyphenylene ether resin (A). The radical polymerizable compound (B) may be a compound having an unsaturated double bond such as styrene, a styrene polymer, acrylonitrile, (meth)acrylic acid, or a (meth)acrylic acid ester, but is preferably a radical polymerizable compound having a group represented by the above formula (a1). The radical polymerizable compound having a group represented by the above formula (a1) is preferably a polyfunctional maleimide compound having two or more groups represented by the formula (a1), and is preferably a bismaleimide compound in which two amino groups of an aromatic diamine or an aliphatic diamine are substituted with a group represented by the formula (a1). Specific examples of aromatic diamines include p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfide, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylether, 3,4'-diaminodiphenylether, and 3,3'-diaminodiphenyl. ether, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, and 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane. Specific examples of the aliphatic diamine include pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, and 2,3,3-trimethylpentane-1,5-diamine. Examples of the radical polymerizable compound having a group represented by the above formula (a1) include 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane and the following compounds (all manufactured by Tokyo Chemical Industry Co., Ltd.), as well as BMI-689, BMI-1400, BMI-1500, BMI-1700, BMI-2700, and BMI-3000 (all manufactured by Designer Molecular Systems, Inc.). [ka]

[0048] As the radical polymerizable compound other than the maleimide compound, various radical polymerizable compounds that have been conventionally blended in radical polymerizable compositions can be used without any particular limitation. Specific examples of the radical polymerizable compound other than the maleimide compound include the following compounds.

[0049] Examples of monofunctional radically polymerizable compounds include (meth)acrylamide, methylol (meth)acrylamide, methoxymethyl (meth)acrylamide, ethoxymethyl (meth)acrylamide, propoxymethyl (meth)acrylamide, butoxymethoxymethyl (meth)acrylamide, N-methylol (meth)acrylamide, N-hydroxymethyl (meth)acrylamide, (meth)acrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, crotonic acid, 2-acrylamido-2-methylpropanesulfonic acid, tert-butylacrylamidosulfonic acid, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, Examples of the acrylates include 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-phenoxy-2-hydroxypropyl (meth)acrylate, 2-(meth)acryloyloxy-2-hydroxypropyl phthalate, glycerin mono(meth)acrylate, tetrahydrofurfuryl (meth)acrylate, dimethylamino (meth)acrylate, glycidyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-tetrafluoropropyl (meth)acrylate, and half (meth)acrylate of phthalic acid derivative. These monofunctional compounds can be used alone or in combination of two or more.

[0050] Examples of the polyfunctional radical polymerizable compound include 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, ethoxylated hexanediol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, 2-hydroxy-3-(meth)acryloyloxypropyl(meth)acrylate, and the like. acrylate, dipentaerythritol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, ethoxylated neopentyl glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, poly(ethylene-propylene) glycol di(meth)acrylate, polytetramethylene glycol di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate ) acrylate, propoxylated bisphenol A di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,6-hexane glycol di(meth)acrylate , trimethylolpropane tri(meth)acrylate, glycerin di(meth)acrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 2,2-Bis(4-(meth)acryloxydiethoxyphenyl)propane, 2,2-bis(4-(meth)acryloxypolyethoxyphenyl)propane, 2-hydroxy-3-(meth)acryloyloxypropyl(meth)acrylate, ethylene glycol diglycidyl ether di(meth)acrylate, diethylene glycol diglycidyl ether di(meth)acrylate, phthalic acid diglycidyl ester di(meth)acrylate, glycerin triacrylate, glycerin polyglycidyl ether poly(meth)acrylate, urethane(meth)acrylate (i.e., tolylene diisocyanate, anate), a reaction product of trimethylhexamethylene diisocyanate, hexamethylene diisocyanate, or the like with 2-hydroxyethyl (meth)acrylate, methylene bis(meth)acrylamide, (meth)acrylamide methylene ether, a condensation product of a polyhydric alcohol and N-methylol (meth)acrylamide, triacrylformal, 2,4,6-trioxohexahydro-1,3,5-triazine-1,3,5-trisethanol triacrylate, and 2,4,6-trioxohexahydro-1,3,5-triazine-1,3,5-trisethanol diacrylate. These polyfunctional compounds can be used alone or in combination of two or more kinds.

[0051] The content of the radical polymerizable compound (B) in the first curable composition is not particularly limited, but is preferably 10 mass % or more and 70 mass % or less based on the total amount of the terminal maleimide-modified polyphenylene ether resin (A) and the radical polymerizable compound (B).

[0052] [Radical Generator (C)] The first curable composition contains a radical generator (C). The radical generator (C) may be a photoradical generator (C1) or a thermal radical generator (C2), or the photoradical generator (C1) and the thermal radical generator (C2) may be used in combination.

[0053] Examples of the photoradical generator (C1) include alkylphenone-based generators such as Omnirad 651, Omnirad 184, Omnirad 1173, Omnirad 2959, Omnirad 127, Omnirad 907, Omnirad 369, Omnirad 369E, and Omnirad 379EG (all manufactured by IGM Resins BV), acylphosphine oxide-based generators such as Omnirad TPO H and Omnirad 819 (all manufactured by IGM Resins BV), and oxime ester-based photopolymerization agents such as Irgacure OXE01 and Irgacure OXE02 (both manufactured by BASF).

[0054] Specific examples of the photoradical generator (C1) include 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, and 1-(4-dodecylphenyl)-2-hydroxy-2-methylpropane. -1-one, 2,2-dimethoxy-1,2-diphenylethan-1-one, bis(4-dimethylaminophenyl)ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(O-benzoyloxime) (Irgacure OXE01), ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]-1-(O-acetyloxime) (Irgacure OXE02), 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO H), bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Omnirad 819), 4-benzoyl-4'-methyldimethyl sulfide, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, butyl 4-dimethylaminobenzoate, 4-dimethylamino-2-ethylhexylbenzoic acid, 4-dimethylamino-2-isoamylbenzoic acid, benzyl-β-methoxyethyl acetal, benzyl dimethyl ketal, 1-phenyl-1,2-propanedione-2-(O-ethoxy) carbonyl) oxime, methyl O-benzoylbenzoate, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 1-chloro-4-propoxythioxanthone, thioxanthene, 2-chlorothioxanthene, 2,4-diethylthioxanthene, 2-methylthioxanthene, 2-isopropylthioxanthene, 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-Diphenylanthraquinone, azobisisobutyronitrile, benzoyl peroxide, cumene hydroperoxide, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2-(O-chlorophenyl)-4,5-di(m-methoxyphenyl)-imidazolyl dimer, benzophenone, 2-chlorobenzophenone, p,p'-bisdimethylaminobenzophenone, 4,4'-bisdiethylaminobenzophenone, 4,4'-dichlorobenzophenone, 3,3-dimethyl-4-methoxy Benzophenone, benzil, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, benzoin butyl ether, acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, dichloroacetophenone, trichloroacetophenone, p-tert-butylacetophenone, p-dimethylaminoacetophenone, p-tert-butyltrichloroacetophenone acetophenone, p-tert-butyldichloroacetophenone, α,α-dichloro-4-phenoxyacetophenone, thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, dibenzosuberone, pentyl-4-dimethylaminobenzoate, 9-phenylacridine, 1,7-bis-(9-acridinyl)heptane, 1,5-bis-(9-acridinyl)pentane, 1,3-bis-(9-acridinyl)propane, p-methoxytriazine, 2,4,6-tris(trichloromethyl)-s-triazine, 2-methyl-4,6- Bis(trichloromethyl)-s-triazine, 2-[2-(5-methylfuran-2-yl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(furan-2-yl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(4-diethylamino-2-methylphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(3,4-dimethoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-(4-methoxyphenyl)-4,Examples of the photoradical generator include 6-bis(trichloromethyl)-s-triazine, 2-(4-ethoxystyryl)-4,6-bis(trichloromethyl)-s-triazine, 2-(4-n-butoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2,4-bis-trichloromethyl-6-(3-bromo-4-methoxy)phenyl-s-triazine, 2,4-bis-trichloromethyl-6-(2-bromo-4-methoxy)phenyl-s-triazine, 2,4-bis-trichloromethyl-6-(3-bromo-4-methoxy)styrylphenyl-s-triazine, and 2,4-bis-trichloromethyl-6-(2-bromo-4-methoxy)styrylphenyl-s-triazine. These photoradical generators can be used alone or in combination of two or more. Among them, it is particularly preferable to use an oxime-based generator in terms of sensitivity.

[0055] Examples of the thermal radical generator (C2) include ketone peroxides (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), peroxyketals (2,2-bis(tert-butylperoxy)butane, 1,1-bis(tert-butylperoxy)cyclohexane, etc.), hydroperoxides (tert-butyl hydroperoxide, cumene hydroperoxide, etc.), dialkyl peroxides (di-tert-butyl peroxide (Perbutyl (registered trademark) D (manufactured by NOF Corporation) and di-tert-hexyl peroxide (Perhexyl (registered trademark) D (manufactured by NOF Corporation))), diacyl peroxides (isobutyryl peroxide, lauroyl peroxide, benzoyl peroxide, etc.), peroxydicarbonates (diisopropyl peroxydicarbonate, etc.), peroxyesters (tert-butyl peroxide, Organic peroxides such as 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), 2,2'-azobis(2-methylpropionamidine) dihydrochloride, 2,2'-azobis[2-methyl and dimethyl 2,2'-azobis(2-methylpropane), 2,2'-azobis(2,4,4-trimethylpentane), and dimethyl 2,2'-azobis(2-methylpropionate).

[0056] The content of the radical generator (C) in the first curable composition is not particularly limited, but is preferably from 0.1 to 10 parts by mass, more preferably from 0.5 to 10 parts by mass, and even more preferably from 2 to 10 parts by mass, relative to 100 parts by mass of the total mass of the terminal maleimide-modified polyphenylene ether resin (A) and the radically polymerizable compound (B).

[0057] <Organic solvent (S)> The first curable composition usually contains an organic solvent (S). The type of the organic solvent (S) is not particularly limited as long as it does not impair the object of the present invention, and may be appropriately selected from organic solvents that have been conventionally used in photosensitive compositions.

[0058] Specific examples of the organic solvent (S) include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; polyhydric alcohols and derivatives thereof such as ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, propylene glycol monomethyl ether acetate, dipropylene glycol, and monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, and monophenyl ether of dipropylene glycol monoacetate; cyclic ethers such as dioxane; and ethyl formate. , methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl pyruvate, ethyl ethoxyacetate, methyl methoxypropionate, ethyl ethoxypropionate, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, and other esters; aromatic organic solvents such as heteroatom-containing aromatic compounds (e.g., anisole) and aromatic hydrocarbons (e.g., toluene, xylene); and the like. These may be used alone or in combination of two or more.

[0059] The content of the organic solvent (S) is not particularly limited as long as it does not impair the object of the present invention. It is preferable to use the organic solvent (S) in such a range that the solid content concentration of the first curable composition is 30% by mass or more and 70% by mass or less.

[0060] [Other additives] The first curable composition may further contain a maleimide curing agent (E) in order to improve the curability, and may further contain a surfactant in order to improve the coatability, defoaming property, leveling property, etc. Examples of maleimide curing agents include diamines; allyl compounds such as low-polarity polyfunctional allylphenol resins (e.g., FATC (manufactured by Gun-ei Chemical Industry Co., Ltd.)), low-polarity allyl ether phenol resins (e.g., FTC-AE (manufactured by Gun-ei Chemical Industry Co., Ltd.)), and allyl ether; 1-propenyl compounds having a 1-propenyl group such as propenylated biphenylene resins (e.g., BPN (manufactured by Gun-ei Chemical Industry Co., Ltd.)), and benzoxazine compounds. As the surfactant, for example, a fluorine-based surfactant or a silicone-based surfactant is preferably used. Specific examples of fluorine-based surfactants include commercially available fluorine-based surfactants such as BM-1000, BM-1100 (all manufactured by BM Chemie), Megafac F142D, Megafac F172, Megafac F173, Megafac F183 (all manufactured by Dainippon Ink and Chemicals), Fluorad FC-135, Fluorad FC-170C, Fluorad FC-430, Fluorad FC-431 (all manufactured by Sumitomo 3M), Surflon S-112, Surflon S-113, Surflon S-131, Surflon S-141, Surflon S-145 (all manufactured by Asahi Glass Co., Ltd.), SH-28PA, SH-190, SH-193, SZ-6032, and SF-8428 (all manufactured by Toray Silicones), but are not limited thereto. As the silicone surfactant, an unmodified silicone surfactant, a polyether-modified silicone surfactant, a polyester-modified silicone surfactant, an alkyl-modified silicone surfactant, an aralkyl-modified silicone surfactant, a reactive silicone surfactant, and the like can be preferably used. As the silicone surfactant, commercially available silicone surfactants can be used. Specific examples of commercially available silicone surfactants include Paintad M (manufactured by Toray Dow Corning Co., Ltd.), Topika K1000, Topika K2000, Topika K5000 (all manufactured by Takachiho Sangyo Co., Ltd.), XL-121 (polyether-modified silicone surfactant, manufactured by Clariant), and BYK-310 (polyester-modified silicone surfactant, manufactured by BYK-Chemie Co., Ltd.).

[0061] The first curable composition may contain an antioxidant. The antioxidant is not particularly limited, and a conventionally known antioxidant can be used, for example, a hindered phenol-based antioxidant (e.g., Irganox 1010 (manufactured by BASF)), a hindered amine-based antioxidant, a phosphorus-based antioxidant, a sulfur-based antioxidant, etc.

[0062] The first curable composition may contain a polymerization inhibitor to appropriately prevent polymerization during the reaction. The polymerization inhibitor is not particularly limited, and a conventionally known polymerization inhibitor can be used, such as methoquinone, hydroquinone, methylhydroquinone, p-methoxyphenol, pyrogallol, tert-butylcatechol, and phenothiazine.

[0063] The first curable composition may contain an adhesion improver in order to improve adhesion between a metal wiring or a substrate for an electric / electronic device having metal wiring and an insulating film formed using the first curable composition. The adhesion improver is not particularly limited, and a conventionally known adhesion improver can be used, for example, benzotriazole.

[0064] [Method for preparing first curable composition] The first curable composition is prepared by mixing and stirring the above-mentioned components in a conventional manner. Examples of devices that can be used when mixing and stirring the above-mentioned components include a dissolver, a homogenizer, and a three-roll mill. After the above-mentioned components are mixed uniformly, the resulting mixture may be further filtered using a mesh, a membrane filter, or the like.

[0065] <Second curable composition> The second curable composition contains a terminal maleimide-modified polyphenylene ether resin (A) and a radical generator (C) like the first curable composition. The use of the second curable composition is not particularly limited. The second curable composition is applicable to various uses in which a conventionally known negative photosensitive resin composition is used. The use of the second curable composition is preferably an insulating film formation use like the first curable composition.

[0066] The terminal-maleimide-modified polyphenylene ether resin (A) used in the second curable composition is similar to the terminal-maleimide-modified polyphenylene ether resin described for the first curable resin composition, except that the linking group present between the terminal group represented by formula (a1) and the oxygen atom derived from the phenolic hydroxyl group of the unmodified polyphenylene ether resin (A') is not particularly limited. The radical generator (C) used in the second curable composition is the above-mentioned photoradical generator (C1).

[0067] The optional components that the second curable composition may contain are the same as those that the first curable composition may contain, and the content of each component in the second curable composition is the same as that in the first curable composition.

[0068] <Method of forming insulating film> An insulating film is formed using the first curable composition or the second curable composition. Hereinafter, the first curable composition and the second curable composition will be collectively referred to as "curable composition". The method for forming the insulating film is as follows: A coating step of coating a curable composition on a portion where an insulating film is to be formed to form a coating film; and a curing step of curing the coating film.

[0069] Preferably, the curable composition can be used to form an insulating film that insulates metal wiring in an electric / electronic device having metal wiring.

[0070] In a method for forming an insulating film, for example, a curable composition is applied to at least a portion of a substrate for an electric / electronic device having metal wiring, where the insulating film is to be formed, to form a coating film. The method for applying the curable composition may be a spin coating method, a slit coating method, a roll coating method, a screen printing method, an inkjet method, an applicator method, etc. When a printing method such as a screen printing method or an inkjet method is applied, it is possible to apply the curable composition only to the area where the insulating film is to be formed.

[0071] The thickness of the coating film is not particularly limited, but is preferably 0.5 μm or more, more preferably 0.5 μm to 300 μm, particularly preferably 1 μm to 150 μm, and most preferably 3 μm to 50 μm.

[0072] Next, the coating film is dried or prebaked as necessary. The prebaking conditions vary depending on the types and blending ratios of each component in the curable composition, the coating film thickness, etc., but are usually from 70° C. to 200° C., preferably from 80° C. to 150° C., for about 2 minutes to 120 minutes.

[0073] When the curable composition contains a photoradical generator (C1), the coating film is irradiated (exposed) with actinic rays or radiation, for example, ultraviolet rays or visible rays having a wavelength of 300 nm or more and 500 nm or less. The entire surface of the coating film may be exposed, or the coating film may be exposed to actinic rays or radiation through a mask having a predetermined pattern, for example, in a position-selective manner (pattern exposure). The exposure causes the polymerization components, resin (A) and radically polymerizable compound (B), to polymerize and form an insulating film, which is formed on, for example, a substrate for an electric / electronic device having metal wiring.

[0074] Examples of radiation sources that can be used include low-pressure mercury lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, and argon gas lasers. Examples of radiation include microwaves, infrared rays, visible light, ultraviolet rays, X-rays, gamma rays, electron beams, proton beams, neutron beams, and ion beams. The radiation dose varies depending on the composition of the curable composition and the thickness of the coating film. For example, when an ultra-high pressure mercury lamp is used, the radiation dose is 100 mJ / cm. 2 More than 10000mJ / cm 2 The radiation may also include light rays that activate the radical generator (C) to generate radicals.

[0075] In the case of site-selective exposure, the exposed coating film is developed according to a conventional method, and unnecessary portions are dissolved and removed to form an insulating film of a desired shape. In this case, the above-mentioned organic solvent (S) or an alkaline aqueous solution can be used as the developer. For example, when the above-mentioned terminal maleimide-modified polyphenylene ether resin (A) has an alkali-soluble group such as a carboxy group or a phenolic hydroxyl group, development with an alkaline aqueous solution is possible.

[0076] Examples of the alkaline aqueous solution used as the developer include aqueous solutions of alkalis such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide (tetramethylammonium hydroxide), tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo[5,4,0]-7-undecene, and 1,5-diazabicyclo[4,3,0]-5-nonane. In addition, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the aqueous solution of the above alkalis can also be used as the developer.

[0077] The developing time varies depending on the composition of the curable composition, the thickness of the coating film, etc., but is usually from 1 minute to 30 minutes. The developing method may be any of a puddle method, a dipping method, a paddle method, a spray developing method, etc.

[0078] After development, the film is washed with running water for 30 to 90 seconds, and then dried using an air gun, an oven, or the like.

[0079] In this manner, for example, an insulating film patterned into a desired shape is formed on a substrate for an electric / electronic device having metal wiring.

[0080] In the above, an example was shown in which the resin (A) and the radical polymerizable compound (B), which are the polymerization components, are polymerized by exposure to light to form an insulating film. When the curable composition contains a thermal radical generator (C2), the resin (A) and the radical polymerizable compound (B), which are the polymerization components, may be polymerized by heating to form an insulating film.

[0081] The formed insulating film has a low dielectric constant and a low dielectric loss tangent, and is therefore suitable as an insulating film for electric and electronic devices having metal wiring for high-frequency applications. For example, it can be used as an insulating film for electric and electronic devices having metal wiring for applications using frequencies of 3 GHz to 30 GHz, which are candidate frequencies for 5G communication bands, and frequencies of 30 GHz to 300 GHz, which are millimeter-wave bands. In addition, the formed insulating film has excellent heat resistance, and is therefore suitable for applications in which the insulating film is heated after formation to further form components such as wiring. EXAMPLES

[0082] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0083] [Preparation Example 1] As the unmodified polyphenylene ether resin (A'), a polyphenylene ether resin having a phenolic hydroxyl group terminal and having the following structure (SA90, manufactured by SABIC Innovative Plastics) was used. [ka]

[0084] 166 parts by mass of unmodified polyphenylene ether resin (A') and 47.2 parts by mass of a carboxylic acid having a maleimide group of the following structure were added to 1184 parts by mass of dichloroethane. [ka]

[0085] After adding 40.9 parts by mass of diisopropylcarbodiimide and 0.25 parts by mass of dimethylaminopyridine to the reaction solution, the modification reaction of the terminal phenolic hydroxyl groups was carried out at 5° C. for 8 hours. After the reaction, the reaction solution was filtered and reprecipitated with acetonitrile to obtain 145 parts by mass of a terminal maleimide-modified polyphenylene ether resin P1 (resin P1) in which the phenolic hydroxyl groups at both ends of the unmodified polyphenylene ether resin (A') were modified to groups of the following formula. The terminal maleimide-modified polyphenylene ether resin P1 had a polystyrene-equivalent mass average molecular weight (Mw) of 7000 measured by gel permeation chromatography (GPC). [ka]

[0086] The obtained terminal maleimide-modified polyphenylene ether resin P1 and polyphenylene ether resin (SA90) were analyzed using deuterated chloroform as the measurement solvent. 1 H NMR measurements were performed. 1 The results of the H NMR measurement are shown in Figure 1. In Figure 1, the upper spectrum is the result of measurement of the polyphenylene ether resin (SA90), and the lower spectrum is the result of measurement of the terminal maleimide-modified polyphenylene ether resin P1. According to FIG. 1, a peak at 6.7 ppm derived from the maleimide skeleton is present in the lower spectrum but not in the upper spectrum, which shows that the terminal-maleimide-modified polyphenylene ether resin P1 is a resin that has been subjected to the desired terminal maleimide modification.

[0087] [Preparation Example 2] A modification reaction of the terminal phenolic hydroxyl group was carried out in the same manner as in Preparation Example 1, except that the carboxylic acid having a maleimide group was changed to 43.6 parts by mass of a compound having the following structure. [ka]

[0088] The phenolic hydroxyl groups at both ends of the unmodified polyphenylene ether resin (A') were modified to the group of the following formula to obtain 126 parts by mass of a terminal maleimide-modified polyphenylene ether resin P2 (resin P2). The terminal maleimide-modified polyphenylene ether resin P2 had a polystyrene-equivalent mass average molecular weight (Mw) of 7000 measured by gel permeation chromatography (GPC). [ka]

[0089] [Preparation Example 3] A modification reaction of the terminal phenolic hydroxyl group was carried out in the same manner as in Preparation Example 1, except that the carboxylic acid having a maleimide group was changed to 57.0 parts by mass of a compound having the following structure. [ka]

[0090] The phenolic hydroxyl groups at both ends of the unmodified polyphenylene ether resin (A') were modified to the group of the following formula to obtain 140 parts by mass of a terminal maleimide-modified polyphenylene ether resin P3 (resin P3). The terminal maleimide-modified polyphenylene ether resin P3 had a polystyrene-equivalent mass average molecular weight (Mw) of 7000 as measured by gel permeation chromatography (GPC). [ka]

[0091] <Preparation of Curable Composition> [Examples 1 to 9 and Comparative Examples 1 to 7] In Examples 1 to 9, the above resins P1 to P3 were used as the resin (A). In Examples 1 to 9 and Comparative Examples 1 to 7, the following B1 to B5 and B6: SA9000 (manufactured by SABIC Innovative Plastics, a modified polyphenylene ether in which the terminal hydroxyl group of polyphenylene ether is modified with a methacryl group) were used as the radical polymerizable compound (B). B1 is BMI-689 and B2 is BMI-3000 (both manufactured by Designer Molecules).

[0092] [ka] [ka]

[0093] In Examples 1 to 9 and Comparative Examples 1 to 7, the following C1 to C4 were used as the radical generator (C). C1: Irgacure OXE01 (BASF) C2: Irgacure OXE02 (BASF) C3: Omnirad 819 (manufactured by IGM Resins BV) C4: Perhexyl D (NOF Corporation) In Examples 1 to 9 and Comparative Examples 1 to 7, the following D1 to D3 and a surfactant (BYK310, manufactured by BYK-Chemie) were used as additives. D1: Irganox 1010 (manufactured by BASF) D2: Methoquinone D3: Benzotriazole

[0094] The types and amounts of the terminal maleimide-modified polyphenylene ether resin (resin (A)) and / or the radical polymerizable compound (B) shown in Tables 1 to 2, the radical generator (C), the additive, and 0.05 parts by mass of a surfactant (BYK310, manufactured by BYK-Chemie) were dissolved in propylene glycol monomethyl ether acetate (PGMEA) to a solid content concentration of 40% by mass, to obtain curable compositions for each of the Examples and Comparative Examples.

[0095] <Evaluation> The obtained curable composition was used to evaluate the film-forming properties, photolithography properties, dielectric constant, dielectric loss tangent, and heat resistance according to the following methods. The evaluation results are shown in Tables 1 and 2. [Film forming and photolithography properties] The curable compositions of the examples and comparative examples were applied onto a Si substrate having a diameter of 200 mm to form a coating film. The coating film was then prebaked (PAB) at 80°C for 200 seconds. The coating film had a thickness of 11 μm after prebaking. After prebaking, a hole pattern mask capable of forming a circular opening having a diameter of 30 μm and an exposure device Prisma GHI5452 (manufactured by Ultratech) were used to expose the film at an exposure dose of 100 mJ / cm. 2 More than 4400mJ / cm 2 The pattern was exposed to Ghi rays as follows. The focus was set at 0 μm (the surface of the coating film). Next, the substrate was placed on a hot plate and subjected to post-exposure baking (PEB) at 90° C. for 1.5 minutes. After that, the exposed coating film was immersed in propylene glycol monomethyl ether acetate (PGMEA) at 60° C. for 60 seconds. After that, nitrogen was blown and the film was heated at 180° C. for 1 hour under a nitrogen atmosphere to obtain a pattern (insulating film). The surface of the coating film before pre-baking was observed by a scanning electron microscope to evaluate the film formability. Specifically, the case where cracks and / or crystals were not observed on the pattern surface, the pattern was free of tack (stickiness), and the contained components were compatible and transparent was rated as ○. In addition, the case where cracks were observed on the pattern surface was rated as a, the case where crystals were observed on the pattern surface was rated as b, the case where tack (stickiness) was present on the pattern surface was rated as c, and the case where the contained components were not compatible and opaque was rated as d. The surface and cross section of the obtained pattern (insulating film) were observed by a scanning electron microscope to evaluate the photolithographic properties. Specifically, in the above-mentioned range of exposure dose, if the conditions existed under which an opening of 30 μm in diameter was formed, it was evaluated as ◯, and if the conditions did not exist under which an opening of 30 μm in diameter was formed, it was evaluated as ×. In addition, in Comparative Example 1, since there was tack and a pattern (insulating film) could not be formed, the dielectric constant, dielectric tangent, and heat resistance were not evaluated. In addition, in Comparative Examples 3 and 4, cracks and crystals were generated in the coating film before pre-baking, so the photolithography characteristics, dielectric constant, dielectric tangent, and heat resistance were not evaluated.

[0096] [Dielectric constant and dielectric loss tangent] The curable compositions of the examples and comparative examples were applied onto a Si substrate having a diameter of 200 mm to form a coating film. The coating film was then prebaked (PAB) at 80°C for 200 seconds. The coating film had a thickness of 11 μm after prebaking. After prebaking, the coating film was exposed to light at an exposure dose of 4400 mJ / cm using a Prisma GHI5452 exposure device (manufactured by Ultratech). 2 The entire surface was exposed to Ghi rays at 1000 nm. The focal point was set at 0 μm (coated film surface). After that, nitrogen was blown onto the coated film surface, and the coated film surface was heated at 180° C. for 1 hour in a nitrogen atmosphere to obtain a sample. The dielectric constant (ε) and dielectric tangent (tanδ) of the obtained sample were measured by the method described in "Study on evaluation of millimeter wave complex dielectric constant of photosensitive insulating film by cylindrical cavity resonator method" (Kohei Takahagi (Utsunomiya University), Kazuaki Ebisawa (Tokyo Ohka Kogyo Co., Ltd.), Yoshinori Kogami (Utsunomiya University), Takashi Shimizu (Utsunomiya University)) in the Technical Report of the Institute of Electronics, Information and Communication Engineers, vol. 118, no. 506, MW2018-158, pp. 13-18, March 2019. The measurements were performed using a network analyzer HP8510C (Keysight Corporation) by the cavity resonator method under the conditions of room temperature 25°C, humidity 50%, frequency 36GHz, and sample thickness 10μm. The dielectric constant was evaluated as follows: when the dielectric constant was less than 3.00, it was rated as ◯; when it was 3.00 or more, it was rated as x. The dielectric loss tangent was evaluated by rating it as follows: if the dielectric loss tangent value was less than 0.01, it was rated as "O"; if it was 0.01 or more, it was rated as "X."

[0097] [Heat resistance] For samples obtained in the same manner as in the [Dielectric constant and dielectric tangent] section, the peak top temperature (°C) of tan δ measured using a dynamic viscoelasticity measuring device Rheogel-E4000 (manufactured by UBM Co., Ltd.) was taken as the glass transition point (Tg) (DMA method). The measurement conditions were: measurement mode: tensile mode, frequency: 10 Hz, heating rate: 5°C / min, measurement temperature range: 40 to 300°C, sample shape: length 50 mm, width 5 mm, thickness 10 μmm. The heat resistance was evaluated by rating it as follows: if Tg was 150° C. or higher, it was rated as ◯; if Tg was less than 150° C., it was rated as x.

[0098] [Table 1]

[0099] [Table 2]

[0100] According to Examples 1 to 9, it is found that a curable composition containing a terminal maleimide-modified polyphenylene ether resin (A) having a group represented by formula (a1) at the molecular chain terminal and a radical generator (C) can form an insulating film having a low dielectric constant and dielectric loss tangent and excellent heat resistance, and has excellent film formability. In addition, in the compositions of Examples 1 to 9, the terminal maleimide-modified polyphenylene ether resin (A) was dissolved in PGMEA. Furthermore, according to Examples 1 to 9, it is also found that the photolithography properties are excellent.

[0101] On the other hand, according to Comparative Examples 1 to 7, when the curable composition does not contain the terminal maleimide-modified polyphenylene ether resin (A), it is difficult to achieve both formation of an insulating film having a low dielectric constant and dielectric tangent and excellent heat resistance and good film formability.

[0102] [Examples 10 to 12] In Example 10, a curable composition was prepared having the same components and amounts as those in Example 1, as shown in Table 3, except that anisole was used instead of PGMEA as the organic solvent, and the obtained curable composition was evaluated in the same manner as in Example 1. In Examples 11 and 12, FATC and FTC-AE (both manufactured by Gun-ei Chemical Industry Co., Ltd.) were mixed as the maleimide curing agent (E) in the amounts shown in Table 3 in Example 10 to prepare curable compositions, and the obtained curable compositions were evaluated in the same manner as in Example 1. FATC is represented by E1 below, and FTC-AE is represented by E2 below.

[0103] [ka]

[0104] [Table 3]

[0105] In the composition of Example 10, the terminal maleimide-modified polyphenylene ether resin (A) was dissolved in anisole. In addition, in the composition of Example 10, as in Example 1, it is possible to form an insulating film having a low dielectric constant and dielectric loss tangent, excellent heat resistance, and excellent photolithography characteristics, and it is also found to have excellent film-forming properties. In addition, the compositions of Examples 11 and 12, which contain a maleimide curing agent (E) as an additive, showed the same results as the composition of Example 10.

Claims

1. A curable composition comprising a terminal maleimide-modified polyphenylene ether resin (A) and a radical generator (C), The terminal maleimide-modified polyphenylene ether resin (A) is represented by the following formula (a1): 【Chemistry 1】 At the molecular chain end, In the formula (a1), R ａ０１ and R ａ０２ each independently represents a hydrogen atom, an alkyl group having from 1 to 6 carbon atoms, a cycloalkyl group having from 3 to 8 carbon atoms, or an aryl group having from 6 to 12 carbon atoms, The phenylene group contained in the main chain of the terminally maleimide-modified polyphenylene ether resin (A) may have one or more and four or less substituents, The terminal group is represented by the following formula (a2): <h2 style=";text-align:left;direction:ltr">*-Y<h2 style=";text-align:left;direction:ltr"> ２ <h2 style=";text-align:left;direction:ltr"> -Y<h2 style=";text-align:left;direction:ltr"> １ <h2 style=";text-align:left;direction:ltr"> I'm sorry and is bonded to the main chain of the terminal maleimide-modified polyphenylene ether resin (A) via a linking group represented by the following formula: a bond on the ** side of the linking group is bonded to an oxygen atom derived from a hydroxyl group at the molecular chain terminal of the unmodified polyphenylene ether resin (A') which gives the maleimide-terminated polyphenylene ether resin (A), the bond on the * side of the linking group is bonded to the terminal group, In the formula (a2), Y １ is a carbonyl group, and Y ２ is a divalent organic group, the divalent organic group is a hydrocarbon group, the hydrocarbon group is a butane-1,4-diyl group, a cyclohexane-1,4-diyl group, or a cyclohexane-1,3-diyl group; A curable composition used for forming an insulating film.

2. The curable composition according to claim 1 , further comprising a radical polymerizable monomer (B) which is a radical polymerizable compound other than the terminal maleimide-modified polyphenylene ether resin (A).

3. The curable composition according to claim 2 , wherein the radical polymerizable monomer (B) comprises a radical polymerizable compound having a group represented by the formula (a1).

4. A cured product of the curable composition according to any one of claims 1 to 3.

5. A coating step of coating a portion where an insulating film is to be formed with the curable composition according to any one of claims 1 to 3 to form a coating film; and curing the coating film.

6. The method for forming an insulating film according to claim 5 , wherein the curable composition contains a photoradical generator (C1) as the radical generator (C), and the coating film is cured by exposure to light.

7. A coating process for forming a coating film by coating a curable composition on an insulating film formation site; and a curing step of curing the coating film by exposure to light, The exposure of the coating film is performed in a position-selective manner; The method further includes a developing step of developing the exposed coating film with a developer, The curable composition contains a terminal maleimide-modified polyphenylene ether resin (A) and a radical generator (C), The terminal maleimide-modified polyphenylene ether resin (A) is represented by the following formula (a1): 【Chemistry 2】 At the molecular chain end, In the formula (a1), R a01 and R a02 each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, or an aryl group having 6 to 12 carbon atoms; The phenylene group contained in the main chain of the terminally maleimide-modified polyphenylene ether resin (A) may have one or more and four or less substituents, The terminal group is represented by the following formula (a2): *-Y 2 -Y 1 -**...(a2) and is bonded to the main chain of the terminal maleimide-modified polyphenylene ether resin (A) via a linking group represented by the following formula: a bond on the ** side of the linking group is bonded to an oxygen atom derived from a hydroxyl group at the molecular chain terminal of the unmodified polyphenylene ether resin (A') which gives the maleimide-terminated polyphenylene ether resin (A), the bond on the * side of the linking group is bonded to the terminal group, In the formula (a2), Y 1 is a carbonyl group, Y 2 is a divalent organic group, the divalent organic group is a hydrocarbon group, the hydrocarbon group is an ethane-1,2-diyl group, a propane-1,3-diyl group, a butane-1,4-diyl group, a cyclohexane-1,4-diyl group, or a cyclohexane-1,3-diyl group; The method for forming an insulating film, wherein the radical generator (C) contains a photoradical generator (C1).

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