Curable resin composition, method for producing resin cured product, and method for producing circuit connector

Abstract

Provided is a curable resin composition comprising: a blocked maleimide compound having a maleimide group blocked by a blocking agent that dissociates when heated; and a reactive component. The reactive component is a compound having a reactive group that reacts with the maleimide group, or a compound that generates the reactive group when heated. The blocking agent may be a compound that dissociates from the maleimide group when heated to 220°C or below and that has a boiling point of 250°C or below.

Description

Curable resin composition, method for producing cured resin body, and method for producing circuit-connected body

[0001] The present disclosure relates to a curable resin composition, a method for producing a cured resin body, and a method for producing a circuit connection body.

[0002] In the three-dimensional packaging of semiconductor chips, hybrid bonding, which bonds electrodes and insulating films, has been considered for miniaturization of wiring. It has also been proposed to form the insulating film for hybrid bonding using a resin material such as polyimide (Patent Document 1).

[0003] On the other hand, it is known that compositions containing maleimide compounds and allyl compounds are thermally cured by addition reactions including ene reactions and Diels-Alder reactions or radical polymerization (Non-Patent Document 1).

[0004] International Publication No. 2020 / 085183

[0005] Handbook of Thermoset Plastics, Third Edition, 2014, p. 459-510

[0006] An insulating film can be formed by curing a resin film containing a curable resin composition containing a maleimide compound. This curable resin composition may require refrigerated storage to suppress viscosity increase due to progress of the curing reaction during storage. One aspect of the present disclosure relates to improving the viscosity stability at room temperature of a curable resin composition containing a maleimide compound.

[0007] The present disclosure includes the following: [1] A curable resin composition comprising: a block maleimide compound having a maleimide group blocked by a blocking agent that dissociates upon heating; and a reactive component that is a compound having a reactive group that reacts with the maleimide group, or a compound that generates the reactive group upon heating. [2] The curable resin composition according to [1], wherein the blocking agent is a compound that dissociates from the maleimide group upon heating at 230°C or less and has a boiling point of 250°C or less. [3] The curable resin composition according to [1] or [2], wherein the blocking agent comprises a diene compound having a diene group. [4] The curable resin composition according to [3], wherein the diene compound is a compound having a furyl group. [5] The curable resin composition according to [3], wherein the reactive component is a compound represented by the following formula (IV): and R ２２ and R ２３are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. [6] The curable resin composition according to any one of [1] to [5], wherein the reactive component comprises an allyl compound having an allyl group. [7] The curable resin composition according to any one of [1] to [7], wherein the reactive component comprises an amine compound having an amino group. [8] The curable resin composition according to any one of [1] to [7], wherein the reactive component comprises a thiol compound having a mercapto group. [9] The curable resin composition according to any one of [1] to [8], wherein the reactive component comprises a phenol compound having a phenolic hydroxyl group.

[10] The curable resin composition according to any one of [1] to [9], wherein the reactive component comprises a benzoxazine compound having a benzoxazine group.

[11] The curable resin composition according to any one of [1] to

[10] , further comprising a solvent.

[12] A method for producing a cured resin product, comprising: forming a thermosetting intermediate molded body from the curable resin composition according to any one of [1] to

[11] ; and forming a cured resin product by proceeding with curing of the intermediate molded body by heat treatment, wherein the intermediate molded body is formed such that the blocking agent dissociates from the block maleimide compound to produce a maleimide compound having a maleimide group in the intermediate molded body.

[13] The method according to

[12] , further comprising storing the curable resin composition in an environment of 20°C or higher and 35°C or lower.

[14] A method for producing a circuit-connected assembly including a first circuit member having a first electrode and a second circuit member having a second electrode, the method comprising: forming a thermosetting first resin film including a portion provided around the first electrode; proceeding with curing of the first resin film by heat treatment, thereby forming a first insulating film from the first resin film; and joining the first circuit member having the first electrode and the first insulating film to the second circuit member having the second electrode and a second insulating film including a portion provided around the second electrode by hybrid bonding so that the first electrode and the second electrode are electrically connected; the first resin film is formed from the curable resin composition according to any one of [1] to

[11] ; and the first resin film is formed such that the blocking agent dissociates from the block maleimide compound, thereby producing a maleimide compound having a maleimide group in the first resin film.

[15] A method for manufacturing a circuit connection body comprising a first circuit member having a first electrode and a second circuit member having a second electrode, the method comprising: forming a thermosetting first resin film including a portion provided around the first electrode; curing the first resin film by heat treatment, thereby forming a first insulating film from the first resin film; forming a thermosetting second resin film including a portion provided around the second electrode; curing the second resin film by heat treatment, thereby forming a second insulating film from the second resin film; and joining the first circuit member having the first electrode and the first insulating film and the second circuit member having the second electrode and the second insulating film by hybrid bonding so that the first electrode and the second electrode are electrically connected; the first resin film and the second resin film are formed from the curable resin composition of any one of [1] to

[11] , the first resin film and the second resin film are formed such that the blocking agent dissociates from the block maleimide compound to produce a maleimide compound having a maleimide group in the first resin film and the second resin film.

[0008] The viscosity stability of the cured resin composition containing the maleimide compound at room temperature can be improved, and the curable resin composition can have excellent storage stability.

[0009] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed.It is to be understood that the following detailed description is exemplary and explanatory and is not restrictive of the invention.

[0010] The present invention is not limited to the following examples.

[0011] Curable Resin Composition An example of a curable resin composition includes a block maleimide compound having a maleimide group blocked with a blocking agent that dissociates upon heating, and a reactive component. The reactive component can be a compound having a reactive group that reacts with the maleimide group, or a compound that generates a reactive group upon heating. Because the maleimide group is blocked with a blocking agent, the progress of curing, including the reaction between the maleimide compound and the reactive component, is suppressed at room temperature (e.g., 20 to 35°C). Therefore, even if the reactive component has high reactivity, the curable resin composition can have high viscosity stability at room temperature. The curable resin composition can be used to form various cured resin products, such as resin films.

[0012] The blocking agent may be a compound that dissociates from the maleimide group when heated at 230° C. or less. The blocking agent may be a compound that dissociates from the maleimide group when heated at 40° C. or more and 230° C. or less.

[0013] When the blocking agent is a compound having a low boiling point, the blocking agent dissociated from the maleimide group can be easily volatilized from the resin film containing the curable resin composition. A small amount of blocking agent remaining in the resin film after curing can be advantageous for suppressing defects in the resin film, such as voids. From this perspective, the blocking agent may be a compound having a boiling point of 250°C or less, or 230°C or less. The boiling point of the compound used as the blocking agent may be 40°C or more. Here, the boiling point means the boiling point under 1 atmosphere.

[0014] The blocking agent may contain a diene compound having a diene group. The diene compound as a blocking agent may be any compound capable of reacting with a maleimide group by a Diels-Alder reaction, and examples thereof include compounds represented by the following formula 2. In formula 2, R １ , R ２ , R ３ , R ４ , R ５ and R ６ are each independently a hydrogen atom or a monovalent organic group. １ , R ２ , R ３ , R ４ , R ５ and R ６ Two groups selected from the following may be bonded to form a cyclic group. Maleimide group 1 and diene compound 2 react rapidly via a Diels-Alder reaction to produce blocked maleimide group 1A. Diene compound 2 is easily dissociated from blocked maleimide group 1A by heating.

[0015] R １ , R ２ , R ３ , R ４ , R ５ and R ６ may each independently be an alkyl group (-R) which may have a substituent, an alkoxycarbonyl group (-C(=O)OR) which may have a substituent, or an alkanoyl group (-C(=O)R) which may have a substituent. Examples of the substituent that the alkyl group, alkoxycarbonyl group, and alkanoyl group may have include a hydroxy group, an alkanoyloxy group (-O(C=O)R), an alkoxycarbonyl group, an alkanoyl group, an aryl group, and a furyl group. R １ , R ２ , R ３ , R ４ , R ５ or R ６ The organic group may have 1 to 10 carbon atoms. ２ and R ６ may be bonded to form a cyclic group which may contain a heteroatom.

[0016] The diene compound may be a compound having a furyl group. The compound having a furyl group is represented by, for example, the following formula (20):

[0017] In formula (20), R １ , R ３ , R ４ and R ５ is R in formula 2 １ , R ３ , R ４ and R ５ For example, R １ is a monovalent organic group, and R ３ , R ４ and R ５ may be a hydrogen atom. Examples of the compound represented by formula (20) include compounds represented by the following formulas (20A), (20B), (20C) and (20D). In these formulas, R ２０ is an alkanediyl group having 1 to 3 carbon atoms (e.g., a methylene group), and R ２１ is an alkyl group having 1 to 6 carbon atoms (for example, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, or an n-hexyl group).

[0018] Specific examples of the compound represented by formula (20) include furfuryl alcohol (boiling point: 170°C), n-propyl 2-furancarboxylate (boiling point: 211°C), 2-acetylfuran (boiling point: 173°C), methyl 2-furancarboxylate (boiling point: 181°C), furfuryl acetate (boiling point: 177°C), ethyl 2-furancarboxylate (boiling point: 196°C), and furfuryl propionate (boiling point: 196°C).

[0019] The block maleimide compound is a compound derived from a maleimide compound having one or more maleimide groups by reaction with a blocking agent. From the viewpoint of improving the heat resistance and reducing the thermal expansion coefficient of a cured resin body formed from the curable resin composition, the curable resin composition may contain a block maleimide compound derived from a maleimide compound having two or more maleimide groups.

[0020] The maleimide compound from which the block maleimide compound is derived may have a maleimide group containing a nitrogen atom directly bonded to a cyclic group (e.g., an aromatic group). For example, the maleimide compound may include a compound represented by the following formula (Ia), (Ib), or (Ic):

[0021] In formula (Ia), Q １ and Q ２ each independently represents a cyclic group which may have a substituent, and L ５ is a divalent organic group or a single bond. １ and Q ２ may each independently be an aromatic group (e.g., a phenylene group) which may have a substituent (e.g., an alkyl group having 1 to 3 carbon atoms). ５ may be a group containing one or more cyclic groups (excluding a maleimide group) selected from a monocyclic ring, a fused ring, a non-fused bridged ring, and a spiro ring, which may have a substituent, an alkylene group having 1 to 5 carbon atoms which may have a substituent (for example, a methylene group, a propane-1,3-diyl group, or a propane-2,2-diyl group), or a single bond. ５ may have two or more cyclic groups and a single bond or a divalent organic group (for example, an optionally substituted methylene group, or an optionally substituted propane-2,2-diyl group) connecting the two or more cyclic groups. ５ is a cyclic group and Q １ or Q ２ and may further have a methylene group connecting L ５ However, L in formula (11) may have a cyclic group formed by removing one or more hydrogen atoms from benzene, 2,3-dihydro-1H-indene, or succinimide. Examples of the maleimide compound represented by formula (Ia) include a compound represented by formula (11) below. ５ is L in formula (Ia) ５ is defined in the same way as R ３１ is an alkyl group having 1 to 3 carbon atoms, and p and q are each independently an integer of 0 to 4. ３１ may be the same or different.

[0022] In formula (Ib), Q３ represents a cyclic group which may have a substituent. ３ may be an aromatic group (e.g., a phenylene group). ３ The cyclic group therein may have a substituent such as an alkyl group having 1 to 3 carbon atoms.

[0023] In formula (Ic), Q ４ , Q ５ and Q ６ are each independently a cyclic group which may have a substituent, and L ６ and L ７ are each independently a divalent organic group or a single bond, and n is an integer of 1 or more. ４ , Q ５ and Q ６ An example of this is Q １ and Q ２ This is similar to the example shown in L. ６ and L ７ An example of ５ Examples of the maleimide compound represented by formula (Ic) include a compound represented by formula (12): ６ and L ７ represents L in formula (Ia). ６ and L ７ where n is an integer of 1 or greater.

[0024] Specific examples of the maleimide compound include compounds represented by the following formulas 101, 102, 103, 104, and 105. In these formulas, n represents an integer of 1 or more.

[0025] Examples of commercially available maleimide compounds include NE-X-9470S (trade name, DIC), MIR-3000-70MT (trade name, Nippon Kayaku), BMI-1000 (trade name, Yamato Chemical Industries), BMI-2300 (trade name, Yamato Chemical Industries), BMI-5100 (trade name, Yamato Chemical Industries), BMI-80 (trade name, Yamato Chemical Industries), BMI (trade name, Yamato Chemical Industries), and SFR-2300MR-T (trade name, Resonac).

[0026] The reactive component may include at least one compound selected from the group consisting of a styrene-based compound, an allyl compound, an amine compound, a thiol compound, a phenolic compound, and a benzoxazine compound. The reactive component may include a styrene-based compound and an allyl compound.

[0027] The styrene-based compound is a compound having, as a reactive group, a group obtained by removing one or more hydrogen atoms bonded to a benzene ring from a compound represented by the following formula (IV): ２２ and R ２３ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms (for example, a methyl group). ２２ is a hydrogen atom, and R ２３ may be a hydrogen atom or an alkyl group having 1 to 3 carbon atoms (e.g., a methyl group). Styrene-based compounds tend to react with maleimide compounds at relatively low temperatures. However, because the maleimide group of the maleimide compound is blocked, the curable resin composition can have high viscosity stability at room temperature.

[0028] The styrene-based compound may have a plurality of reactive groups. The reactive group of the styrene-based compound is represented, for example, by the following formula (IVa) or (IVb). R in formula (IVa) and (IVb) ２２ and R ２３ is R in formula (IV). ２２ and R ２３ is defined in the same way as R １１ and R １２ is an alkyl group having 1 to 3 carbon atoms, p is an integer of 0 to 3, and q is an integer of 0 to 4. １１ and R １２ may be the same or different.

[0029] The styrene-based compound may be a polymer containing a structural unit represented by the following formula (41) or (42): ２２ and R ２３ is R in formula (IV) ２２ and R ２３ In formula (41), L １is a single bond or a divalent organic group, and R １１ is an alkyl group having 1 to 3 carbon atoms (for example, a methyl group), and p is an integer of 0 to 3. ２ is a single bond or a divalent organic group, and R １２ is an alkyl group having 1 to 3 carbon atoms (for example, a methyl group), and q is an integer of 0 to 4.

[0030] L １ or L ２ Examples of the divalent organic group as the aryl group include an oxy group (—O—), a —C(R １６ ) (R １７ )-, carbonyl group (-C(=O)-), carbonyloxy group (-C(=O)O-), amide group (-C(=O)NH-), carbonate group (-OC(=O)O-), sulfonyl group (-S(=O) ２ -), and thio groups (-S-). １６ and R １７ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

[0031] The polymer as the styrene-based compound may further contain a structural unit represented by the following formula (43): ３ is a single bond or a divalent organic group, and R １３ is an alkyl group having 1 to 3 carbon atoms, and r is an integer of 0 to 4. ３ Examples of divalent organic groups as L １ and L ２ The examples of the divalent organic group are the same as those of the above.

[0032] The styrene-based compound may be a polymer containing a structural unit represented by the following formula (401) or a polymer represented by the following formula (402). ２１ , R ２２ , L １ , L ２ , L ３ , R １１ , R １２ , R １３ , p, q and r are R in formula (41), (42) or (43). ２１ , R２２ , L １ , L ２ , L ３ , R １１ , R １２ , R １３ , p, q and r are defined in the same manner. １１ , L １２ and L １３ are each independently a single bond or a divalent organic group, and R １４ is an alkyl group having 1 to 3 carbon atoms (for example, a methyl group), s is an integer of 0 to 4, and m and n are each independently an integer of 1 or more. １１ , L １２ or L １３ Examples of divalent organic groups as L １ or L ２ The examples of divalent organic groups are the same as those of the above. １４ may be the same or different.

[0033] The molecular weight of the styrene-based compound may be 200 or more and 100,000 or less. The weight average molecular weight and / or number average molecular weight of the styrene-based compound may be 500 or more and 100,000 or less. In this specification, the weight average molecular weight and number average molecular weight may be values ​​calculated as standard polystyrene measured by gel permeation chromatography.

[0034] The reactive component may include an allyl compound having an allyl group as a reactive group. The allyl compound may have one or more allyl groups (2-propenyl group, —CH ２ CH=CH ２ From the viewpoints of improving the heat resistance and reducing the thermal expansion coefficient of the cured resin, the curable resin composition may contain an allyl compound having two or more allyl groups.

[0035] The allyl compound may include a compound having a cyclic group and an allyl group or an allyloxy group directly bonded to the cyclic group. For example, the allyl compound in the curable maleimide resin composition may include a compound represented by the following formula (Va), (Vb), (Vc), or (Vd):

[0036] In formulas (Va) and (Vb), Q ７ and Q ８ each independently represents a cyclic group which may have a substituent, L ８ represents a divalent organic group or a single bond. ７ and Q ８ may each independently be a group in which one or more hydrogen atoms have been removed from benzene, isocyanuric acid, or nadimide. ８ may be a group containing one or more cyclic groups (excluding a maleimide group) selected from a monocyclic ring, a fused ring, a non-fused bridged ring, and a spiro ring, which may have a substituent, a linear alkylene group (e.g., a methylene group or a propane-1,3-diyl group) which may have a substituent, a propane-2,2-diyl group which may have a substituent, or a single bond. ８ may have two or more cyclic groups and a single bond or a divalent organic group (for example, an optionally substituted methylene group, or an optionally substituted propane-2,2-diyl group) connecting the two or more cyclic groups. ８ is a cyclic group and Q ７ or Q ８ and may further have a methylene group connecting L ８ The cyclic group in L may be substituted with a substituent selected from, for example, a methyl group, a hydroxy group, and an allyl group. ８ may have a phenylene group which may have a substituent.

[0037] In formulas (Vc) and (Vd), Q ９ represents a cyclic group which may have a substituent. ９ may be an aromatic group (e.g., a phenylene group) or a group in which one or more hydrogen atoms have been removed from isocyanuric acid. ９ The cyclic groups therein may be substituted, for example, with methyl or allyl groups.

[0038] Specific examples of the allyl compound include compounds represented by the following formulae 501, 502, 503, 504, 505, 506, 507, 508, and 509. In these formulae, n represents an integer of 1 or more.

[0039] Examples of commercially available allyl compounds include DABPA (trade name, Kanto Chemical), DA-BPF (trade name, Yokkaichi Chemical Industry), LVA01 (trade name, Gun-ei Chemical Industry), BPA-AE (trade name, Konishi Chemical Industry), BANI-X (trade name, Maruzen Petrochemical Industry), BANI-M (trade name, Maruzen Petrochemical Industry), FATC-809 (trade name, Gun-ei Chemical Industry), FATC-809AP (trade name, Gun-ei Chemical Industry), DAIC (trade name, Shikoku Chemical Industry), and DD-1 (trade name, Shikoku Chemical Industry).

[0040] The curable resin composition may contain an allyl compound (hereinafter sometimes referred to as an "allylamino compound") having a reactive group represented by the following formula (5). The allylamino compound may have a plurality of reactive groups represented by formula (5). The allylamino compound tends to react with the bismaleimide compound at relatively low temperatures. However, because the maleimide group is blocked, the curable resin composition can have high viscosity stability at room temperature.

[0041] The allylamino compound may be a compound represented by the following formula (50): ２４ and R ２５ are each independently a hydrogen atom or a monovalent organic group, and R ２４ and R ２５ may be bonded to each other to form a cyclic group.

[0042] R ２４ or R ２５ The monovalent organic group represented by R may be a hydrocarbon group (for example, an alkyl group having 1 to 6 carbon atoms) which may have a substituent. ２４ and R ２５ may be bonded to each other to form a cyclic group having 4 to 8 members. Specific examples of the allylamino compound include compounds represented by the following formula 510:

[0043] The amine compound is a compound having an amino group as a reactive group. The amine compound can be an aliphatic amine, an aromatic amine, or a combination thereof. Examples of the aliphatic amine include cyclohexylamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,4-diaminocyclohexane, 4,4'-methylenebis(cyclohexylamine), 4,4'-methylenebis(2-methylcyclohexylamine), and 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5.5]-undecane. Examples of aromatic amines include aniline, toluidine, naphthylamine, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 4,4'-diaminodiphenylmethane (MDA), m-phenylenediamine (MPD), 4,4'-diaminodiphenyl ether, 2'-methoxy-4,4'-diaminobenzanilide, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane (BAPP), 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxy-4,4'-diaminobiphenyl, 4,4'-diaminobenzanilide, bisanilinefluorene, 2,2-bis-[4-(3-aminophenoxy)phenyl]propane, bis[4-(4 ... bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)]biphenyl, bis[4-(3-aminophenoxy)biphenyl, bis[1-(4-aminophenoxy)]biphenyl, bis[1-(3-aminophenoxy)]biphenyl, bis[4-(4-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)]benzophenone, bis[4-(3-aminophenoxy)]benzophenone, bis[4,4'-(4-aminophenoxy)]benzanilide, bis[4,4'-(3-aminophenoxy)]benzanilide, 9,9-bis[4-(4-aminophenoxy)phenyl]fluorene, 9,9-bis[4-(3-aminophenoxy)phenyl]fluorene, 2,2-bis-[4-(4-aminophenoxy)phenyl]hexafluoropropane, 2,2-bis-[4-(3-aminophenoxy)phenyl]hexafluoropropane, 4,4'-methylenedi-o-toluidine, 4,4'-methylenedi-2,6-xylidine, 4,4'-methylene-2,6-diethylaniline, 4,4'-diaminodiphenylpropane, 3,3'-diaminodiphenylpropane 4,4'-diaminodiphenylethane, 3,3'-diaminodiphenylethane, 3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 3,3-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, benzidine, 3,3'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethoxybenzidine, 4,4''-diamino Amino-p-terphenyl, 3,3''-diamino-p-terphenyl, p-phenyleneamine, 2,6-diaminopyridine, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline, 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisaniline, bis(p-aminocyclohexyl)methane, bis(p-β-amino-t-butylphenyl)ether, bis(p-β-methyl-δ-aminophenyl)ether p-bis(2-methyl-4-aminopentyl)benzene, p-bis(1,1-dimethyl-5-aminopentyl)benzene, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 2,4-bis(β-amino-t-butyl)toluene, 2,4-diaminotoluene, m-xylene-2,5-diamine, p-xylene-2,5-diamine, m-xylylenediamine, p-xylylenediamine, 2,6-diaminopyridine, 2,5-diaminopyridine, and 2,5-diamino-1,3,4-oxadiazole.

[0044] The thiol compound is a compound having a mercapto group as a reactive group. The thiol compound may be a dithiol compound having two mercapto groups, examples of which include 1,2-ethanethiol, 1,3-dimercaptopropane, 1,4-dimercaptobutane, bis(2-mercaptoethyl)ether, bis(2-mercaptoethyl)sulfide, and bis(2-mercaptoethyl)sulfone.

[0045] The phenol compound is a compound having a phenolic hydroxyl group as a reactive group. The benzoxazine compound is a compound having a benzoxazine group. The benzoxazine compound can generate the phenolic hydroxyl group as a reactive group by heating.

[0046] The content of the reactive component may be 10% by mass or more and 80% by mass or less, based on the total amount of the block maleimide compound and the reactive component. The content of the reactive component may be 15% by mass or more, 20% by mass or more, 25% by mass or more, or 30% by mass or more, based on the total amount of the block maleimide compound and the reactive component, and may be 75% by mass or less, 70% by mass or less, 65% by mass or less, or 60% by mass or less. The total content of the block maleimide compound and the reactive component may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more, or may be 100% by mass or less, based on the total amount of components in the curable resin composition excluding the solvent.

[0047] The curable resin composition may further contain a solvent that dissolves or disperses the block maleimide compound and the reactive component. Examples of the solvent include γ-butyrolactone, cyclohexanone, cyclopentanone, mesitylene, N,N-dimethylformamide, propylene glycol monomethyl ether acetate, and ethyl lactate. The content of the solvent may be, for example, 10% by mass or more and 300% by mass or less, based on the total amount of the block maleimide compound and the reactive component.

[0048] The curable resin composition may further include a component that initiates or accelerates the reaction of the maleimide compound and the reactive component.

[0049] The curable resin composition may further contain a component that reduces the dielectric loss tangent of the cured resin (insulating film) (hereinafter referred to as a "dielectric loss tangent adjuster"). The dielectric loss tangent adjuster includes, for example, an aromatic compound represented by the following formula (VIa), (VIb), or (VIc):

[0050] In formula (VIa), R ４１ , R ４４ and R ４５ each independently represents a hydrogen atom, a methyl group, or a t-butyl group; R ４２ and R ４３ each independently represents a hydrogen atom, a hydroxy group, or an organic group having 1 to 30 carbon atoms; Z １ represents an organic group having 7 to 80 carbon atoms and containing at least one heteroatom selected from the group consisting of sulfur, phosphorus, oxygen, and nitrogen, or an organic group having 2 to 15 carbon atoms and containing a carbonyl group.

[0051] In formula (VIb), R ４６ , R ４９ , R ５０ , R ５１ , R ５２ and R ５５ each independently represents a hydrogen atom, a methyl group, or a t-butyl group; R ４７ , R ４８ , R ５３ and R ５４ each independently represents a hydrogen atom, a hydroxy group, or an organic group having 1 to 30 carbon atoms; Z ２ represents a divalent organic group having 1 to 50 carbon atoms containing at least one heteroatom selected from the group consisting of sulfur, phosphorus, oxygen, and nitrogen, or a divalent organic group having 1 to 75 carbon atoms.

[0052] In formula (VIc), R ５６ , R ５９ , R ６０ , R ６１ , R ６４ , R ６５ , R ６６ , R ６７ and R ７０ each independently represents a hydrogen atom, a methyl group, or a t-butyl group; R ５７ , R ５８ , R ６２ , R６３ , R ６８ and R ６９ each independently represents a hydrogen atom, a hydroxyl group, or an organic group having 1 to 30 carbon atoms; Z ３ represents a trivalent organic group having 1 to 50 carbon atoms containing at least one heteroatom selected from the group consisting of sulfur, phosphorus, oxygen, and nitrogen, or a trivalent organic group having 1 to 50 carbon atoms.

[0053] The content of the dielectric loss tangent adjuster may be 1% by mass or more and 50% by mass or less, based on the total amount of the block maleimide compound and the reactive component. The content of the dielectric loss tangent adjuster may be 2% by mass or more or 5% by mass or more, based on the total amount of the block maleimide compound and the reactive component, and may be 50% by mass or less or 40% by mass or less.

[0054] The curable resin composition may further include an adhesion promoter, such as a silane coupling agent, an aluminum-based adhesion promoter, or a combination thereof.

[0055] Examples of the silane coupling agent include γ-aminopropyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, 3-methacryloxypropyldimethoxymethylsilane, 3-methacryloxypropyltrimethoxysilane, dimethoxymethyl-3-piperidinopropylsilane, diethoxy-3-glycidoxypropylmethylsilane, N-( 3-diethoxymethylsilylpropyl)succinimide, N-[3-(triethoxysilyl)propyl]phthalamic acid, benzophenone-3,3'-bis(N-[3-triethoxysilyl]propylamido)-4,4'-dicarboxylic acid, benzene-1,4-bis(N-[3-triethoxysilyl]propylamido)-2,5-dicarboxylic acid, 3-(triethoxysilyl)propyl succinic anhydride, and N-phenylaminopropyltrimethoxysilane.

[0056] Examples of aluminum-based adhesion promoters include aluminum tris(ethylacetoacetate), aluminum tris(acetylacetonate), and ethylacetoacetate aluminum diisopropylate.

[0057] The content of the adhesion promoter may be, for example, 0.5% by mass or more and 25% by mass or less based on the total amount of the block maleimide compound and the reactive component.

[0058] The curable resin composition may further contain a polymerization inhibitor. Examples of the polymerization inhibitor include hydroquinone, N-nitrosodiphenylamine, p-tert-butylcatechol, 4-methoxyphenol, phenothiazine, N-phenylnaphthylamine, ethylenediaminetetraacetic acid, 1,2-cyclohexanediaminetetraacetic acid, glycol ether diaminetetraacetic acid, 2,6-di-tert-butyl-p-methylphenol, 5-nitroso-8-hydroxyquinoline, 1-nitroso-2-naphthol, 2-nitroso-1-naphthol, 2-nitroso-5-(N-ethyl-N-sulfopropylamino)phenol, N-nitroso-N-phenylhydroxylamine ammonium salt, and N-nitroso-N(1-naphthyl)hydroxylamine ammonium salt.

[0059] The content of the polymerization inhibitor may be 0.005% by mass or more and 12% by mass or less based on the total amount of the block maleimide compound and the reactive component.

[0060] The curable resin composition may further contain an azole compound. Examples of the azole compound include 1H-triazole, 5-methyl-1H-triazole, 5-ethyl-1H-triazole, 4,5-dimethyl-1H-triazole, 5-phenyl-1H-triazole, 4-t-butyl-5-phenyl-1H-triazole, 5-hydroxyphenyl-1H-triazole, phenyltriazole, p-ethoxyphenyltriazole, 5-phenyl-1-(2-dimethylaminoethyl)triazole, 5-benzyl-1H-triazole, hydroxyphenyltriazole, 1,5-dimethyltriazole, 4,5-diethyl-1H-triazole, 1H-benzotriazole, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, and 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]benzotriazole. triazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)benzotriazole, 2-(3,5-di-t-amyl-2-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, hydroxyphenylbenzotriazole, tolyltriazole, 5-methyl-1H-benzotriazole, 4-methyl-1H-benzotriazole, 4-carboxy-1H-benzotriazole, 5-carboxy-1H-benzotriazole, 1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, 5-amino-1H-tetrazole, and 1-methyl-1H-tetrazole.

[0061] The content of the azole compound may be 0.1% by mass or more and 20% by mass or less, or 0.5% by mass or more and 5% by mass or less, based on the total amount of the block maleimide compound and the reactive component.

[0062] The curable resin composition may contain a hindered phenol compound. Examples of the hindered phenol compound include 2,6-di-t-butyl-4-methylphenol, 2,5-di-t-butyl-hydroquinone, octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 4,4'-methylenebis(2,6-di-t-butylphenol), 4,4'-thio-bis(3-methyl-6-t-butylphenol), and 4,4'-butylidene-bis(3-methyl-6-t-butylphenol). 1,6-hexanediol bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 2,2'-methylene-bis(4-methyl-6-t-butylphenol), 2,2 '-Methylene-bis(4-ethyl-6-t-butylphenol), pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 1,3,5-tris(3-hydroxy-2,6-dimethyl-4-isopropylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5 H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-s-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris[4-(1-ethylpropyl)-3-hydroxy-2,6-dimethylbenzyl]-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris[4-triethylmethyl-3-hydroxy-2,6-dimethylbenzyl]-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(3-hydroxy-2,6-dimethyl-4-phenylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2,5,6-trimethylbenzyl)-1,3 ,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-5-ethyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-6-ethyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5 -tris(4-t-butyl-6-ethyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-5,6-diethyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2-methylbenzyl)- Examples include 1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, and 1,3,5-tris(4-t-butyl-5-ethyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione.

[0063] The content of the hindered phenol compound may be 0.1% by mass or more and 20% by mass or less, or 0.5% by mass or more and 10% by mass or less, based on the total amount of the block maleimide compound and the reactive component.

[0064] The curable resin composition may contain an organic titanium compound, such as a titanium chelate compound having two or more alkoxy groups, a tetraalkoxytitanium compound, a titanocene compound, a monoalkoxytitanium compound, a titanium oxide compound, a titanium tetraacetylacetonate compound, a titanate coupling agent, or a combination thereof.

[0065] Examples of titanium chelate compounds having two or more alkoxy groups include titanium bis(triethanolamine) diisopropoxide, titanium di(n-butoxide) bis(2,4-pentanedionate), titanium diisopropoxide bis(2,4-pentanedionate), titanium diisopropoxide bis(tetramethylheptanedionate), and titanium diisopropoxide bis(ethylacetoacetate).

[0066] Examples of tetraalkoxytitanium compounds include titanium tetra(n-butoxide), titanium tetraethoxide, titanium tetra(2-ethylhexoxide), titanium tetraisobutoxide, titanium tetraisopropoxide, titanium tetramethoxide, titanium tetramethoxypropoxide, titanium tetramethylphenoxide, titanium tetra(n-nonyloxide), titanium tetra(n-propoxide), titanium tetrastearyloxide, and titanium tetrakis[bis{2,2-(allyloxymethyl)butoxide}].

[0067] Examples of titanocene compounds include pentamethylcyclopentadienyltitanium trimethoxide, bis(η5-2,4-cyclopentadien-1-yl)bis(2,6-difluorophenyl)titanium, and bis(η5-2,4-cyclopentadien-1-yl)bis(2,6-difluoro-3-(1H-pyrrol-1-yl)phenyl)titanium.

[0068] Examples of monoalkoxytitanium compounds include titanium tris(dioctylphosphate) isopropoxide and titanium tris(dodecylbenzenesulfonate) isopropoxide.

[0069] Examples of titanium oxide compounds include titanium oxide bis(pentanedionate), titanium oxide bis(tetramethylheptanedionate), and phthalocyanine titanium oxide.

[0070] An example of a titanium tetraacetylacetonate compound is titanium tetraacetylacetonate.

[0071] An example of a titanate coupling agent is isopropyl tridodecylbenzenesulfonyl titanate.

[0072] The content of the organotitanium compound may be 0.05% by mass or more and 10% by mass or less, or 0.1% by mass or more and 2% by mass or less, based on the total amount of the block maleimide compound and the reactive component.

[0073] The curable resin composition may further comprise a tertiary amine. Examples of tertiary amines include N,N-bis(3-dimethylamino-propyl)N-isopropanolamine, N,N-dimethylaminoethyl-N'-methylethanolamine (DABCO™ T, Air Products and Chemicals, Inc. of Allentown, PA), N,N,N'-trimethylaminopropylethanolamine (POLYCAT™ 17 from Air Products and Chemicals, Inc.), N,N-dimethylethanolamine (DABCO™ DMEA), N,N-dimethyl-N',N'-2-hydroxy(propyl)-1,3-propylenediamine, dimethylaminopropylamine (DMAPA), (N,N-dimethylaminoethoxy)ethanol, methyl-hydroxy-ethyl-piperazine, bis(N,N-dimethyl-3-aminopropyl)amine (POLYCAT™ 15), N,N-dimethylaminopropylurea (DABCO™ NE 1060, DABCO™ NE 1070), N,N'-bis(3-dimethylaminopropyl)urea (DABCO™ NE 1060, DABCO™ NE 1070), bis(dimethylamino)-2-propanol, 6-dimethylamino-1-hexanol, N-(3-aminopropyl)imidazole, N-(2-hydroxypropyl)-2-methylpropanol, N-(2-hydroxypropyl)imidazole, and N-(2-hydroxyethyl)imidazole.

[0074] The content of the tertiary amine may be 0.1% by mass or more and 15% by mass or less based on the total amount of the block maleimide compound and the reactive component.

[0075] The curable resin composition can be produced by a method including reacting a maleimide compound with a blocking agent in a solution containing the maleimide compound, a blocking agent, a reactive component, and a solvent to produce a block maleimide compound. The reaction between the maleimide compound and the blocking agent often proceeds rapidly at a temperature of, for example, 20° C. or higher and 40° C. or lower.

[0076] Methods for producing cured resin products and circuit-connected bodies The curable resin compositions exemplified above can be used to form various cured resin products such as resin films. Methods for forming cured resin products include, for example, forming an intermediate molded body from the curable resin composition and promoting the curing of the intermediate molded body by heat treatment to form the cured resin product.

[0077] The intermediate molded body is a molded body containing the curable resin composition before curing, and may be, for example, a resin film. When the curable resin composition contains a solvent, the intermediate molded body is formed by removing the solvent from the curable resin composition in a predetermined shape. The intermediate molded body is formed so that a maleimide compound having a maleimide group is produced in the intermediate molded body by dissociating the blocking agent from the block maleimide compound. Curing of the curable resin composition forming the intermediate molded body progresses by heat treatment of the thermosetting intermediate molded body containing the maleimide compound. The solvent-containing curable resin composition may be heated to remove the solvent and dissociate the blocking agent from the block maleimide compound. The curable resin composition may be heated to dissociate the blocking agent from the block maleimide compound and remove the blocking agent. The heating temperature for dissociating and removing the blocking agent and, if necessary, removing the solvent, may be, for example, 60°C or higher and 150°C or lower, or 90°C or higher and 120°C or lower.

[0078] The curable resin composition may be stored before being used to form a cured resin body. Since the curable resin composition has high viscosity stability at room temperature, it does not necessarily need to be stored in a refrigerator. For example, the curable resin composition may be stored in an environment of 20°C or higher and 35°C or lower. The storage period may be, for example, one hour or longer and one year or shorter.

[0079] By heat-treating the intermediate molded body, a cured resin body containing the cured or semi-cured curable resin composition can be formed. The cured resin body containing the semi-cured curable resin composition may be polished, bonded to another member, or otherwise processed, and then heated again to further promote curing. The heating temperature for forming the cured resin body containing the cured or semi-cured curable resin composition may be, for example, 100°C or higher and 300°C or lower.

[0080] The curable resin composition can be used to form a cured resin film or insulating film of a circuit-connecting structure. For example, the curable resin composition can be used to produce a circuit-connecting structure by hybrid bonding.

[0081] 1, 2, and 3 are process diagrams illustrating an example of a method for manufacturing a circuit connection body. The method illustrated in FIGS. 1 to 3 includes preparing a first circuit member 10 having a first substrate 11, a first electrode 12, and a first insulating film 13; preparing a second circuit member 20 having a second substrate 21, a second electrode 22, and a second insulating film 23; and joining the first circuit member 10 and the second circuit member 20 by hybrid bonding so that the first electrode 12 and the second electrode 22 are electrically connected. This method forms a circuit connection body 1, which is a bonded assembly of the first circuit member 10 and the second circuit member 20. In hybrid bonding, for example, the first circuit member 10 and the second circuit member 20 are heated and pressurized, thereby bonding the first circuit member 10 and the second circuit member 20 so that the first insulating film 13 and the second insulating film 23 are bonded and the first electrode 12 and the second electrode 22 are bonded.

[0082] At least one of the first substrate 11 or the second substrate 21 may be a semiconductor substrate having a circuit surface. In this case, a semiconductor device is obtained as the circuit-connected body 1. Typically, an integrated circuit is provided on the circuit surface side of the semiconductor substrate. For example, the first substrate 11 may be a semiconductor wafer, and the second substrate 21 may be a semiconductor chip. A plurality of second circuit members 20 having semiconductor chips may be bonded to a single first circuit member 10 having a semiconductor wafer. In this case, the semiconductor wafer (first substrate 11) of the obtained circuit-connected body may be singulated into a plurality of semiconductor chips. The semiconductor substrate may be, for example, a silicon substrate. When the first circuit member 10 or the second circuit member 20 is not a semiconductor substrate, they may be various types of wiring substrates (e.g., interposers).

[0083] The first circuit member 10 has a plurality of first electrodes 12, and a first insulating film 13 is provided around the first electrodes 12 and includes a portion filling the gaps between the plurality of first electrodes 12. The first electrodes 12 and the first insulating film 13 are provided on a first substrate 11. When the first substrate 11 is a semiconductor substrate having a circuit surface, the first electrodes 12 and the first insulating film 13 are provided on the circuit surface. The first insulating film 13 forms a plurality of openings 13a which are through holes exposing the first substrate 11, and the first electrodes 12 are provided in the openings 13a.

[0084] The second circuit member 20 has a plurality of second electrodes 22, and the second insulating film 23 is provided around the second electrodes 22 and includes a portion that fills the gaps between the plurality of second electrodes 22. The second electrodes 22 and the second insulating film 23 are provided on a second substrate 21. When the second substrate 21 is a semiconductor substrate, the second electrodes 22 and the second insulating film 23 are provided on the circuit surface. The second insulating film 23 forms a plurality of openings 23a that are through holes that expose the second substrate 21, and the second electrodes 22 are provided in the openings 23a.

[0085] The first circuit member 10 is prepared by a method including providing a first electrode 12 on a main surface 11S of a first substrate as shown in FIG. 1(a), forming a first resin film 13A on the main surface 11S of the first substrate 11 facing the first electrode 12 as shown in FIG. 1(b), and forming a first insulating film 13 by heat-treating the first resin film 13A as shown in FIG. 1(c).

[0086] The first electrode 12 is made of a conductive material containing a metal such as copper. The first electrode 12 containing a metal can be formed by a common method such as plating.

[0087] The first resin film 13A is formed, for example, by applying a curable resin composition having flowability. The curable resin composition having flowability may contain a solvent. When a curable resin composition containing a solvent is used, the first resin film 13A can be formed by heating the applied curable resin composition to remove the solvent. Heating to remove the solvent may dissociate the blocking agent from the maleimide compound and may further volatilize the blocking agent. The blocking agent may remain in the first resin film 13A. The heating temperature for removing the solvent and dissociating the blocking agent may be, for example, 60°C or higher and 150°C or lower, or 90°C or higher and 120°C or lower. The first resin film 13A may be formed to cover the entire first electrodes 12 while filling the gaps between the multiple first electrodes 12. By heating the formed first resin film 13A, the first resin film 13A is cured or semi-cured to form the first insulating film 13. The first insulating film 13 contains a cured or semi-cured curable resin composition. The fact that the first insulating film 13 contains a semi-cured curable resin composition can be confirmed, for example, by observing heat generation due to curing in a DSC thermogram obtained by differential scanning calorimetry of a sample of the first insulating film 13. In the case of a cured curable resin composition, heat generation due to curing is not substantially observed.

[0088] The above-described curable resin composition can be cured or semi-cured at a relatively low temperature to form an insulating film through the progress of a curing reaction involving a maleimide compound and a reactive component. The ability to cure at a low temperature is advantageous in terms of reducing thermal damage to the first circuit board, etc. Furthermore, since the curing reaction is primarily an addition reaction such as radical polymerization and Diels-Alder reaction, it is unlikely to generate volatile components due to elimination components.

[0089] The surface of the first insulating film 13 formed from the curable resin composition containing the maleimide compound may contain many functional groups derived from maleimide groups, etc. Therefore, the first insulating film 13 may exhibit good bonding properties without necessarily requiring an activation treatment such as a plasma treatment. In addition, it may be possible to adjust the polishing rate of the first insulating film 13 based on the crosslink density, etc., of the first insulating film 13.

[0090] The temperature of the heat treatment of the first resin film 13A to form the first insulating film 13 may be, for example, 100°C or higher and 150°C or lower, or 150°C or higher and 300°C or lower. The heat treatment time may be, for example, 5 minutes or higher and 120 minutes or lower. The heat treatment conditions may be adjusted so that the first resin film 13A is semi-cured. The thickness of the first insulating film 13 may be 1 μm or higher or 10 μm or higher, or 100 μm or lower or 10 μm or lower.

[0091] When the formed first insulating film 13 covers the first electrode 12 as shown in FIG. 1C , a portion of the first insulating film 13 is removed from the side opposite the first substrate 11, thereby forming an opening 13a in the first insulating film 13 that exposes the first electrode 12 as shown in FIG. 2D . The portion of the first insulating film 13 may be removed by polishing. A conventional polishing method, such as chemical mechanical polishing (CMP), may be used. The polishing may also remove a portion of the first electrode 12, thereby planarizing the tip surface of the first electrode 12 (the surface opposite the first substrate 11). Depending on the polishing rate, the height of the first electrode 12 may be greater than the thickness of the first insulating film 13 in the polished first circuit member 10. The difference between the height of the first electrode 12 and the thickness of the first insulating film 13 may be adjusted taking into account the difference in the linear thermal expansion coefficients of the first electrode 12 and the first insulating film 13, for example. The difference between the height of the first electrode 12 and the thickness of the first insulating film 13 may be, for example, 0.1 μm or more and 0.5 μm or less.

[0092] The second insulating film 23 of the second circuit member 20 can be an organic insulating film or an inorganic insulating film. When the second insulating film 23 is an organic insulating film, the second circuit member can be prepared in the same manner as the first circuit member 10, including heat treatment of the second resin film containing a curable resin composition. When both the first insulating film 13 and the second insulating film 23 are organic insulating films formed from a curable resin composition containing a maleimide compound, particularly good bonding properties are likely to be exhibited. The first insulating film 13 and the second insulating film 23 can be formed using the same or different curable resin compositions.

[0093] The shapes of the first electrode 12 and the second electrode 22 are not particularly limited, but some or all of these electrodes are arranged so that the first electrode 12 and the second electrode 22 face each other and are bonded to each other. The widths of the first electrode 12 and the second electrode 22 may be, for example, 1 μm or more or 100 μm or more, and 300 μm or less or 30 μm or less. Here, width refers to the maximum width of each electrode in a direction parallel to the main surface (circuit surface) of the first substrate 11 or the second substrate 21. The spacing between adjacent first electrodes 12 and adjacent second electrodes 22 may be, for example, 1 μm or more or 100 μm or more, and 300 μm or less or 30 μm or less. The heights of the first electrodes 12 and the second electrodes 22 may be, for example, 1 μm or more or 10 μm or more, and 100 μm or less or 10 μm or less. The height of the first electrode 12 may be the same as or different from the thickness of the first insulating film 13. The height of the second electrode 22 may be the same as or different from the thickness of the second insulating film 23.

[0094] From the viewpoint of bonding between electrodes, the surface of the tip of the first electrode 12 may have a surface roughness Ra of 1 nm or less. The surface of the tip of the second electrode 22 may also have a similar surface roughness Ra. The surface roughness Ra here is the arithmetic mean roughness (Ra) defined in JIS B 0601-2001.

[0095] 2(e), the prepared first circuit member 10 and second circuit member 20 are aligned so that the first electrode 12 and second electrode 22 to be bonded face each other. Then, as shown in FIG. 3, the first circuit member 10 and second circuit member 20 are heated and pressurized to bond the first electrode 12 and second electrode 22 and to bond the first insulating film 13 and second insulating film 23 together by hybrid bonding.

[0096] The bonding of the first electrode 12 and the second electrode 22 and the bonding of the first insulating film 13 and the second insulating film 23 may proceed simultaneously or sequentially. For example, after heating and pressurizing mainly for bonding the first insulating film 13 and the second insulating film 23, the first circuit member 10 and the second circuit member 20 may be further heated and pressurized to bond the first electrode 12 and the second electrode 22. The first insulating film 13 and / or the second insulating film 23 may be in a semi-cured state before bonding. In this case, the first insulating film 13 and / or the second insulating film 23 may be further cured during the heating and pressurizing for bonding the first circuit member 10 and the second circuit member 20. The first insulating film 13 and / or the second insulating film 23 may be further cured by heating after bonding.

[0097] The conditions for heating and pressing for bonding are adjusted so that the insulating film and the electrode are properly bonded. For example, the heating temperature for bonding may be 150° C. or higher and 250° C. or lower, and the pressure for bonding may be 1.0 MPa or higher and 5.0 MPa or lower. The heating and pressing time may be, for example, 10 seconds or higher and 1 hour or lower.

[0098] [Examples] The present invention is not limited to the following examples. 1. The following raw materials were prepared: (A) Maleimide Compound A1: Phenylmethanemaleimide (BMI-2300, Daiwa Chemical Industry Co., Ltd.) (B) Styrene-Based Compound B1 2,2'-Diallylbisphenol A (Tokyo Chemical Industry Co., Ltd., 6.00 mmol, 1.85 g), 4,4'-difluorobenzophenone (Tokyo Chemical Industry Co., Ltd., 5.00 mmol, 1.09 g), and potassium carbonate (Fujifilm Wako Pure Chemical Industries, Ltd., 30.0 mmol, 4.15 g) were placed in a three-necked flask. N-methylpyrrolidone (30 mL) and toluene (15 mL) were then added. The three-necked flask was equipped with a reflux condenser and a Dean-Stark receiver, and the system was conditioned with a nitrogen atmosphere. The reaction solution in the three-necked flask was heated while stirring. After the internal temperature reached 155°C, stirring was continued for an additional 30 minutes to allow the reaction to proceed. The reaction solution in the three-necked flask was then cooled to room temperature, and N-methylpyrrolidone (30 mL) was added thereto. The reaction solution was washed several times with water and ethanol, and then filtered to obtain a styrene-based compound B1 (white solid) (yield: 50%, weight average molecular weight: 1500). １ The H-NMR spectrum confirmed that a 1-propenyl group was formed. (C) Blocking agent: Furfuryl alcohol (compound represented by formula (20A)) (D) Solvent: Propylene glycol monomethyl ether acetate (MPA)

[0099] 2. Curable Resin Composition (Varnish) A solution containing maleimide compound A1 and MPA was prepared. Furfuryl alcohol was added to the solution, and the solution was stirred for 1 hour while being heated to 65 to 75°C. After the temperature of the solution was lowered to room temperature, the MPA solution of styrene-based compound B1 was added to the solution, and the mixture was stirred at room temperature for 30 minutes to obtain a varnish of a curable resin composition. Varnishes of Examples 1 to 4 were prepared containing each component in the blending ratio (parts by mass) shown in Table 1. Varnishes of Comparative Examples 1 and 2 were also prepared in the same manner, except that furfuryl alcohol was not added, containing each component in the blending ratio shown in Table 1.

[0100] 3. Stability The viscosity of the varnish immediately after preparation (initial viscosity η ０ The viscosity η of the varnish after standing at room temperature for 1 hour was measured. １ Table 1 shows the viscosity measurement results and the viscosity ratio η １ / η ０The varnishes of the examples in which furfuryl alcohol was introduced exhibited stable viscosity, which is thought to be because the maleimide compound was blocked by furfuryl alcohol.

[0101]

[0102] 1...circuit connector, 10...first circuit member, 11...first substrate, 12...first electrode, 13...first insulating film, 13a, 23a...opening, 13A...first resin film, 20...second circuit member, 21...second substrate, 22...second electrode, 23...second insulating film.

Claims

1. A curable resin composition comprising: a blocked maleimide compound having a maleimide group blocked with a blocking agent that dissociates upon heating; and a reactive component that is a compound having a reactive group that reacts with the maleimide group, or a compound that generates the reactive group upon heating.

2. The curable resin composition according to claim 1, wherein the blocking agent is a compound that dissociates from the maleimide group when heated at 230°C or less and has a boiling point of 250°C or less.

3. The curable resin composition according to claim 1, wherein the blocking agent comprises a diene compound having a diene group.

4. The curable resin composition according to claim 3, wherein the diene compound is a compound having a furyl group.

5. The reactive component is represented by the following formula (IV): and R ２２ and R ２３ are each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.

6. The curable resin composition according to claim 1, wherein the reactive component comprises an allyl compound having an allyl group.

7. The curable resin composition according to claim 1, wherein the reactive component comprises an amine compound having an amino group.

8. The curable resin composition according to claim 1, wherein the reactive component comprises a thiol compound having a mercapto group.

9. The curable resin composition according to claim 1, wherein the reactive component comprises a phenolic compound having a phenolic hydroxyl group.

10. The curable resin composition of claim 1, wherein the reactive component comprises a benzoxazine compound having a benzoxazine group.

11. The curable resin composition of claim 1, further comprising a solvent.

12. A method for producing a cured resin product, comprising: forming a thermosetting intermediate molded product from the curable resin composition according to any one of claims 1 to 11; and forming a cured resin product by proceeding with the curing of the intermediate molded product by heat treatment, wherein the intermediate molded product is formed in such a way that a maleimide compound having a maleimide group is produced in the intermediate molded product by dissociating the blocking agent from the block maleimide compound.

13. The method according to claim 11, further comprising storing the curable resin composition in an environment of 20°C or higher and 35°C or lower.

14. A method for producing a circuit connection body comprising a first circuit member having a first electrode and a second circuit member having a second electrode, the method comprising: forming a thermosetting first resin film including a portion provided around the first electrode; proceeding with curing of the first resin film by heat treatment, thereby forming a first insulating film from the first resin film; and joining the first circuit member having the first electrode and the first insulating film to the second circuit member having the second electrode and a second insulating film including a portion provided around the second electrode by hybrid bonding so that the first electrode and the second electrode are electrically connected; the first resin film is formed from the curable resin composition according to any one of claims 1 to 11; and the first resin film is formed so that the blocking agent dissociates from the block maleimide compound, thereby producing a maleimide compound having a maleimide group in the first resin film.

15. A method for producing a circuit connection body comprising a first circuit member having a first electrode and a second circuit member having a second electrode, the method comprising: forming a thermosetting first resin film including a portion provided around the first electrode; curing the first resin film by heat treatment, thereby forming a first insulating film from the first resin film; forming a thermosetting second resin film including a portion provided around the second electrode; curing the second resin film by heat treatment, thereby forming a second insulating film from the second resin film; and joining the first circuit member having the first electrode and the first insulating film and the second circuit member having the second electrode and the second insulating film by hybrid bonding so that the first electrode and the second electrode are electrically connected; the first resin film and the second resin film are formed from the curable resin composition according to any one of claims 1 to 11; the first resin film and the second resin film are formed such that the blocking agent dissociates from the block maleimide compound to produce a maleimide compound having a maleimide group in the first resin film and the second resin film.

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