Photosensitive resin composition

Abstract

To provide a photosensitive resin composition that can form an insulating layer having small marginal resolution and excellent adhesion to a GaAs substrate.SOLUTION: A photosensitive resin composition for forming an insulating layer on a GaAs substrate is provided, containing (A) an alkali-soluble resin having a hydroxy group, (B) a melamine resin containing one or more alkoxymethyl groups, (C) a photoacid generator, and (D) a silane coupling agent containing a trimethoxy silyl group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a photosensitive resin composition, and a photosensitive film, circuit board, and semiconductor device using the same. [Background technology]

[0002] Circuit boards such as wafer-level packages typically have an insulating layer on a substrate such as a wafer. This insulating layer may be formed using a photosensitive resin composition (Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2018-155938 [Patent Document 2] Japanese Patent Publication No. 2018-173573 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] The insulating layer may have openings such as holes and trenches formed by exposure and development of the photosensitive resin composition. Due to the recent progress in miniaturization of wiring, these openings need to be small. Therefore, the photosensitive resin composition is required to have a low limiting resolution. "Limiting resolution" refers to the limit of how small the openings that can be formed in the photosensitive resin composition by exposure and development can be, and the smaller the resolution, the better.

[0005] On the other hand, circuit boards using GaAs substrates (gallium arsenide substrates) are sometimes used as substrates that can operate at higher speeds than silicon substrates. In the insulating layer formed on the GaAs substrate using a photosensitive resin composition, adhesion to the GaAs substrate is also required. However, currently there is no photosensitive resin composition that can form an insulating layer with low limiting resolution and excellent adhesion to the GaAs substrate, and there is a need to develop a photosensitive resin composition that excels in both characteristics.

[0006] The present invention was devised in view of the above-mentioned problems, and aims to provide: a photosensitive resin composition capable of forming an insulating layer with low limiting resolution and excellent adhesion to a GaAs substrate; a photosensitive film comprising a photosensitive resin composition layer containing the above-mentioned photosensitive resin composition; a circuit board comprising an insulating layer containing a cured product of the above-mentioned photosensitive resin composition and a method for manufacturing the same; and a semiconductor device comprising the circuit board. [Means for solving the problem]

[0007] The inventors diligently studied to solve the aforementioned problems. As a result, the inventors found that a photosensitive resin composition comprising a combination of (A) an alkali-soluble resin having a hydroxyl group, (B) a melamine resin containing one or more alkoxymethyl groups, (C) a photoacid generator, and (D) a silane coupling agent containing a trimethoxysilyl group can solve the aforementioned problems, and thus completed the present invention. In other words, the present invention includes the following:

[0008] [1] A photosensitive resin composition for forming an insulating layer on a GaAs substrate, (A) Alkali-soluble resin having a hydroxyl group, (B) Melamine resin containing one or more alkoxymethyl groups, (C) Photoacid generator, and (D) Silane coupling agent containing a trimethoxysilyl group, A photosensitive resin composition containing [the specified element]. 〔2〕The photosensitive resin composition according to 〔1〕, wherein the component (D) contains 11.5 mass% or more of Si atoms in the molecule. 〔3〕The photosensitive resin composition according to 〔1〕 or 〔2〕, which contains an (E) organic filler. 〔4〕The photosensitive resin composition according to 〔3〕, wherein the amount of the (E) organic filler is 7 mass% or more and 30 mass% or less when the non-volatile components of the photosensitive resin composition are 100 mass%. 〔5〕The photosensitive resin composition according to any one of 〔1〕 to 〔4〕, wherein the component (A) contains a compound having a structure represented by the following formula (A-1).

Chemical formula

Chemical formula

[10] A semiconductor device comprising the circuit board described in [8] or [9].

[11] (I) A step of forming a photosensitive resin composition layer on a GaAs substrate, comprising the photosensitive resin composition described in any one of claims 1 to 6. (II) A step of exposing the photosensitive resin composition layer, (III) A step of developing the photosensitive resin composition layer, A method for manufacturing a circuit board, comprising the elements in this order. [Effects of the Invention]

[0009] The present invention provides a photosensitive resin composition capable of forming an insulating layer with low limiting resolution and excellent adhesion to a GaAs substrate; a photosensitive film comprising a photosensitive resin composition layer containing the photosensitive resin composition; a circuit board comprising an insulating layer containing a cured product of the photosensitive resin composition and a method for manufacturing the same; and a semiconductor device comprising the circuit board. [Modes for carrying out the invention]

[0010] The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples listed below, and may be implemented with modifications as appropriate without departing from the scope of the claims and their equivalents.

[0011] [1. Overview of Photosensitive Resin Compositions] A photosensitive resin composition according to one embodiment of the present invention is a composition for forming an insulating layer on a GaAs substrate. This photosensitive resin composition comprises a combination of (A) an alkali-soluble resin having hydroxyl groups, (B) a melamine resin containing one or more alkoxymethyl groups, (C) a photoacid generator, and (D) a silane coupling agent containing a trimethoxysilyl group. In the following description, "(A) an alkali-soluble resin having hydroxyl groups" may be referred to as "(A) alkali-soluble resin." Also, "(B) a melamine resin containing one or more alkoxymethyl groups" may be referred to as "(B) melamine resin." Furthermore, the silane coupling agent containing a trimethoxysilyl group (D) may be referred to as "(D) silane coupling agent."

[0012] This photosensitive resin composition can have a low limiting resolution. Furthermore, this photosensitive resin composition can form an insulating layer with excellent adhesion to a GaAs substrate.

[0013] The photosensitive resin composition may contain any additional components in combination with components (A) to (D). A preferred optional component is, for example, (E) an organic filler.

[0014] [2. (A) Alkali-soluble resins containing hydroxyl groups] The photosensitive resin composition includes (A) an alkali-soluble resin having hydroxyl groups as component (A). Since the hydroxyl groups of (A) the alkali-soluble resin can undergo a crosslinking reaction with (B) the melamine resin, a latent image can be formed on the photosensitive resin composition layer by exposure. Furthermore, since (A) the alkali-soluble resin can dissolve in an alkaline developer, the aforementioned latent image can be developed. (A) The alkali-soluble resin may be used alone or in combination of two or more types.

[0015] (A) Preferred examples of alkali-soluble resins include compounds having the structure represented by the following formula (A-1). Therefore, (A) alkali-soluble resins preferably contain compounds having the structure represented by the following formula (A-1). Compounds having the structure represented by formula (A-1) may hereinafter be referred to as "component (A-1)".

[0016] [ka] (In formula (A-1), R 3 X represents a divalent group represented by formula (a) below, a divalent group represented by formula (b) below, a divalent group represented by formula (c) below, or a divalent group consisting of a combination thereof. 3 and X 4Each of these independently represents an optionally substituted alkyl group, an optionally substituted aryl group, a halogen atom, or an optionally substituted monovalent heterocyclic group, and each of n3 and n4 independently represents an integer from 0 to 4.

[0017] [ka]

[0018] (In formula (a), R 11 and R 12 Each of these independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted monovalent heterocyclic group, an amino group, a carbonyl group, a carboxyl group, or a group consisting of a combination thereof, R 11 and R 12 They may be joined together to form a ring. * represents a bond. In formula (b), X 11 Each of these independently represents an alkyl group which may have substituents. p1 represents an integer from 0 to 4. * represents a bond. In formula (c), X 12 and X 13 Each of the following independently represents an optionally substituted alkyl group. p2 and p3 independently represent integers from 0 to 4. * represents a bond.

[0019] In formula (A-1), X 3 and X 4 Each of these independently represents an optionally substituted alkyl group, an optionally substituted aryl group, a halogen atom, or an optionally substituted monovalent heterocyclic group. Among these, X 3 and X 4 Preferably, the alkyl group may have substituents, the aryl group may have substituents, and the halogen atom; more preferably, the alkyl group may have substituents and the aryl group may have substituents; and even more preferably, the alkyl group may have substituents.

[0020] The alkyl group may be linear, branched, or cyclic. The cyclic alkyl group may be monocyclic or polycyclic. Preferably, the alkyl group has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 3 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, isopropyl, s-butyl, t-butyl, 2-methylpropyl, and 3-heptyl groups. Among these, the methyl group is particularly preferred.

[0021] The aryl group is preferably one having 6 to 30 carbon atoms, more preferably one having 6 to 20 carbon atoms, and even more preferably one having 6 to 10 carbon atoms. Examples of aryl groups include phenyl groups and naphthyl groups.

[0022] Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, with fluorine atoms being preferred.

[0023] As monovalent heterocyclic groups, monovalent heterocyclic groups having 3 to 21 carbon atoms are preferred, monovalent heterocyclic groups having 3 to 15 carbon atoms are more preferred, and monovalent heterocyclic groups having 3 to 9 carbon atoms are even more preferred. Monovalent heterocyclic groups also include monovalent aromatic heterocyclic groups (heteroaryl groups). Examples of monovalent heterocyclic groups include thienyl, pyrrolyl, furanyl, furyl, pyridyl, pyridadinyl, pyrimidyl, pyrazinyl, triazinyl, pyrrolidyl, piperidyl, quinolyl, and isoquinolyl groups. Among these, pyrrolidyl groups are preferred. A monovalent heterocyclic group is a group obtained by removing one hydrogen atom from the heterocyclic ring of a heterocyclic compound.

[0024] X 3 and X 4 The alkyl group, aryl group, and monovalent heterocyclic group represented by may have substituents. Examples of substituents include halogen atoms, -OH, and -OC. 1-6 Alkyl, -N(C1-6 (alkyl group)2, C 1-6 alkyl group, C 6-10 aryl group, -NH2, -NH(C 1-6 alkyl group), -CN, -C(O)O-C 1-6 alkyl group, -C(O)H, -NO2, etc. are exemplified.

[0025] In this specification, the expression "may have a substituent" means, unless otherwise specified, unsubstituted or usually having 1 to 5 (preferably 1, 2 or 3) substituents. When having a plurality of substituents, these substituents may be the same or different from each other. Further, in this specification, "C p-q "(p and q are positive integers and satisfy p < q.) This term represents that the number of carbon atoms of the organic group described immediately after this term is p to q. For example, the expression "C 1-6 alkyl group" represents an alkyl group having 1 to 6 carbon atoms.

[0026] In formula (A-1), n3 and n4 each independently represent an integer of 0 to 4, preferably represent an integer of 0 to 3, more preferably represent 0 or 1, and particularly preferably represent 1.

[0027] In formula (A-1), R 3 represents a divalent group represented by formula (a), a divalent group represented by formula (b), a divalent group represented by formula (c), or a divalent group composed of a combination thereof.

[0028] In formula (a), R 11 and R 12 each independently represent a hydrogen atom, an alkyl group which may have a substituent, an aryl group which may have a substituent, a monovalent heterocyclic group which may have a substituent, an amino group, a carbonyl group, a carboxyl group, or a group composed of a combination thereof, and R 11 and R 12 may be bonded to each other to form a ring. Among them, R 11 and R 12 each independently represent a hydrogen atom or an alkyl group, preferably.

[0029] R 11 and R 12 The optionally substituted alkyl group, optionally substituted aryl group, and optionally substituted monovalent heterocyclic group represented by are X in formula (A-1). 3 and X 4 This may be equivalent to an alkyl group having a substituent, an aryl group having a substituent, and a monovalent heterocyclic group having a substituent.

[0030] Examples of groups consisting of these combinations include groups consisting of an alkyl group and a carbonyl group, groups consisting of an aryl group and a carbonyl group, groups consisting of an alkyl group, an amino group and a carbonyl group, and groups consisting of an aryl group, an amino group and a carbonyl group.

[0031] R 11 and R 12 They may be bonded to each other to form a ring. 11 and R 12 The ring structures that may be formed include spiro rings and fused rings. In this case, R 11 and R 12 Preferably, the group is a group that forms a cyclopentane ring, a cyclohexane ring, a 2,2-dimethyl-4-methylcyclohexane ring, a fluorene ring, a pyrrolidine ring, or a γ-lactam ring.

[0032] The following are specific examples of divalent groups represented by formula (a). In the formula, "*" represents a bond.

[0033] [ka]

[0034] [ka]

[0035] X in equations (b) to (c) 11 , X 12 , and X 13 Each of these independently represents an alkyl group which may have substituents. 11 ~X 13 This is X in equation (A-1). 3 and X 4 This is similar to an alkyl group which may have substituents represented by .

[0036] In equations (b) to (c), p1, p2, and p3 each independently represent an integer between 0 and 4, preferably an integer between 0 and 3, and more preferably 0 or 1.

[0037] The following are specific examples of divalent groups represented by formula (b). In the formula, "*" represents a bond.

[0038] [ka]

[0039] The following are specific examples of divalent groups represented by formula (c). In the formula, "*" represents a bond.

[0040] [ka]

[0041] R 3 Examples of divalent groups formed by the combinations shown include divalent groups formed by the combination of a divalent group represented by formula (b) and a divalent group represented by formula (c), divalent groups formed by the combination of a divalent group represented by formula (a) and a divalent group represented by formula (b), and divalent groups formed by the combination of a divalent group represented by formula (a) and a divalent group represented by formula (c). Specific examples of these groups include the following groups. In the formulas, "*" represents a bond.

[0042] [ka]

[0043] The bonds in formulas (a) to (c) are preferably bonded to the OH group of the phenol moiety in formula (A-1) at the ortho, meta, or para position, more preferably at the meta or para position, and even more preferably at the para position.

[0044] Examples of component (A-1) include the following compounds.

[0045] [ka]

[0046] [ka]

[0047] [ka]

[0048] [ka]

[0049] [ka]

[0050] [ka]

[0051] [ka]

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] (A-1) Component may be a commercially available product. Specific examples of commercially available (A-1) components include: "BisE" and "BisP-HTG" from Honshu Chemical Co., Ltd.; "BisA," "BisF," and "BisP-M" from Mitsui Chemicals Fine Co., Ltd.; "BisP-AP," "BisP-MIBK," "BisP-B," "Bis-Z," "BisP-CP," "o,o'-BPF," "BisP-IOTD," "BisP-IBTD," "BisP-DED," and "BisP-BA" from Honshu Chemical Co., Ltd.; and "Bis-C" from Honshu Chemical Co., Ltd. , "Bis26X-A", "BisOPP-A", "BisOTBP-A", "BisOCHP-A", "BisOFP-A", "BisOC-Z", "BisOC-FL", "BisOC-CP", "BisOCHP-Z" ", "MethylenebisP-CR", "TM-BPF", "BisOC-F", "Bis3M6B-IBTD", "BisOC-IST", "BisP-IST", "BisP-PRM", "BisP-LV", etc.

[0056] (A-1) Component may be used alone or in combination of two or more types.

[0057] The molecular weight of component (A-1) is preferably 150 or more, more preferably 160 or more, even more preferably 170 or more, preferably 1000 or less, more preferably 800 or less, and even more preferably 500 or less.

[0058] The amount of component (A-1) is preferably 6% by mass or more, more preferably 8% by mass or more, even more preferably 10% by mass or more, preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less, when the nonvolatile components of the photosensitive resin composition are taken as 100% by mass. When the amount of component (A-1) is within the above range, both critical resolution and adhesion to the GaAs substrate can be effectively improved.

[0059] The amount of component (A-1) is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less, when the total resin component of the photosensitive resin composition is taken as 100% by mass. The resin component of the photosensitive resin composition refers to the non-volatile components of the photosensitive resin composition, excluding fillers such as (E) organic fillers and inorganic fillers. When the amount of component (A-1) is within the above range, both critical resolution and adhesion to the GaAs substrate can be effectively improved.

[0060] The amount of component (A-1) is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, preferably 70% by mass or less, more preferably 60% by mass or less, and even more preferably 50% by mass or less, when the total amount of alkali-soluble resin (A) is considered to be 100% by mass. When the amount of component (A-1) is within the above range, both critical resolution and adhesion to the GaAs substrate can be effectively improved.

[0061] (A) Another preferred example of an alkali-soluble resin is a compound containing the structure represented by the following formula (A-2). Therefore, (A) the alkali-soluble resin preferably contains a compound containing the structure represented by the following formula (A-2). The compound containing the structure represented by formula (A-2) may hereafter be referred to as "component (A-2)".

[0062] [ka]

[0063] (In formula (A-2), R 1 Each of these independently represents a divalent group represented by formula (a); X 1 Each of these independently represents an optionally substituted alkyl group, an optionally substituted aryl group, a halogen atom, or an optionally substituted monovalent heterocyclic group; n1 represents an integer from 0 to 4; m1 represents an integer from 1 to 200. * represents a bond.

[0064] In formula (A-2), X 1 Each of these independently represents an optionally substituted alkyl group, an optionally substituted aryl group, a halogen atom, or an optionally substituted monovalent heterocyclic group. 1 Each of these independently relates to X in equation (A-1). 3 and X 4 It could be similar to that.

[0065] In formula (A-2), R 1 Each of these independently represents a divalent group represented by formula (a). The divalent group represented by formula (a) is as described above.

[0066] The bonds in formula (a) are preferably bonded to the OH group of the phenol moiety in formula (A-2) at either the ortho, meta, or para position, more preferably bonded to either the meta or para position, and even more preferably a mixture of bonds bonded to both the meta and para positions. When the bonds in formula (a) are bonded to the OH group of the phenol moiety in formula (A-2) at either the meta or para position, let m be the mass of the bonds in formula (a) bonded at the meta position, and p be the mass of the bonds in formula (a) bonded at the para position. In this case, the mixing ratio (m:p) is preferably 1:0.1 to 1:10, more preferably 1:0.1 to 1:5, even more preferably 1:0.1 to 1:2, and particularly preferably 1:0.5 to 1:1.

[0067] In formula (A-2), n1 represents an integer between 0 and 4, preferably an integer between 0 and 3, more preferably 0 or 1, and particularly preferably 1.

[0068] In formula (A-2), m1 represents an integer between 1 and 200, preferably between 1 and 150, more preferably between 1 and 100, and even more preferably between 1 and 50.

[0069] (A-2) A specific example of component (A-2) is the resin represented by the following formula (1). In this specific example, the phenol moiety has a mixture of 60% meta and 40% para OH groups. In formula (1), n ​​represents an integer from 1 to 200.

[0070] [ka]

[0071] (A-2) Component may be a commercially available product. Specific examples of commercially available (A-2) components include Asahi Organic Chemicals Co., Ltd.'s "TR4020G" (resin represented by formula (1)); Asahi Organic Chemicals Co., Ltd.'s "TR4050G", "TR4080G", "TR5020G", "TR5050G", "TR6020G", "TR6050G", "TR6080G", "OC4500", "TRM30B20G", "TRM30B35G", "EP16F30G", "EP16F50G", "TR4000B", "EP0090G", "EP3010A", "PAPS-PN2", "PAPS-PN4", "AYPN-3.5", and other AV light series; Examples include the photoresist resin series from Tomo Bakelite Co., Ltd.; the Resitopp series from Gun-ei Chemical Industry Co., Ltd.; the phenolite series from DIC Corporation, such as "PR-30-40P", "PR-100L", "PR-100H", "PR-50", "PR-55", "PR-56-1", "PR-56-2", "WR-101", "WR-102", "WR-103", and "WR-104"; "LF-100", "LF-110", "LF-120", "LF-200", "LF-400", and "LF-500" from Lignite Co., Ltd.; and the photoresist base resin series from Meiwa Kasei Co., Ltd.

[0072] (A-2) Component (A-2) may be used alone or in combination of two or more types.

[0073] Component (A-2) can be obtained, for example, by polycondensation of phenol or its derivative with an aldehyde and / or ketone. Polycondensation can be carried out in the presence of a catalyst such as an acid or a base. For this reason, the terminal end of component (A-2) may be a hydroxyphenyl group or aldehyde group which may have substituents, and it is preferable that both terminal ends are hydroxyphenyl groups which may have substituents.

[0074] The weight-average molecular weight of component (A-2) is preferably 500 or more, more preferably 700 or more, even more preferably 1000 or more, preferably 150,000 or less, more preferably 100,000 or less, and even more preferably 50,000 or less. The weight-average molecular weight can be measured as a polystyrene equivalent value by gel permeation chromatography (GPC).

[0075] The amount of component (A-2) is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, preferably 80% by mass or less, more preferably 70% by mass or less, and even more preferably 65% ​​by mass or less, when the nonvolatile components of the photosensitive resin composition are considered to be 100% by mass. When the amount of component (A-2) is within the above range, both critical resolution and adhesion to the GaAs substrate can be effectively improved.

[0076] The amount of component (A-2) is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, when the resin component of the photosensitive resin composition is taken as 100% by mass. When the amount of component (A-2) is within the above range, both critical resolution and adhesion to the GaAs substrate can be effectively improved.

[0077] The amount of component (A-2) is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more, when the total amount of alkali-soluble resin (A) is considered to be 100% by mass. The upper limit is usually 100% by mass or less, and may be 90% by mass or less, 80% by mass or less, 70% by mass or less, etc. When the amount of component (A-2) is within the above range, both critical resolution and adhesion to the GaAs substrate can be effectively improved.

[0078] When Wa1 is the mass of component (A-1) relative to 100% by mass of the total alkali-soluble resin (A), and Wa2 is the mass of component (A-2) relative to 100% by mass of the total alkali-soluble resin (A), the mass ratio Wa1 / Wa2 is preferably 0.1 or more, more preferably 0.2 or more, more preferably 0.3 or more, preferably 0.9 or less, more preferably 0.8 or less, and even more preferably 0.7 or less.

[0079] (A) The amount of alkali-soluble resin is preferably 30% by mass or more, more preferably 35% by mass or more, even more preferably 40% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, when the non-volatile components of the photosensitive resin composition are taken as 100% by mass. (A) When the amount of alkali-soluble resin is within the above range, both limiting resolution and adhesion to the GaAs substrate can be effectively improved.

[0080] (A) The amount of alkali-soluble resin is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less, when the resin component of the photosensitive resin composition is taken as 100% by mass. (A) When the amount of alkali-soluble resin is within the above range, both limiting resolution and adhesion to the GaAs substrate can be effectively improved.

[0081] [3. (B) Melamine resin containing one or more alkoxymethyl groups] The photosensitive resin composition includes (B) a melamine resin containing one or more alkoxymethyl groups as component (B). Since the alkoxymethyl groups contained in (B) the melamine resin can react with and bond to the hydroxyl groups of (A) the alkali-soluble resin, the photosensitive resin composition layer can become insoluble in the developer solution or harden to form an insulating layer upon exposure.

[0082] (B) The alkoxymethyl groups contained in melamine resin are represented by the following formula (B-1). In formula (B-1), "*" represents a bond.

[0083] [ka]

[0084] In formula (B-1), R 21 represents an alkyl group which may have substituents. The alkyl group may be linear, branched, or cyclic. Furthermore, the cyclic alkyl group may be monocyclic or polycyclic. Preferably, the alkyl group has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, and even more preferably 1 to 4 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, isopropyl, s-butyl, and t-butyl groups. Among these, methyl and butyl groups are preferred, and methyl groups are more preferred.

[0085] R 21 The alkyl group represented by may have substituents.

[0086] The alkoxymethyl group is preferably contained in an alkoxymethylamino group represented by the following formula (B-1'). Therefore, (B) melamine resin is preferably contained in an alkoxymethylamino group represented by the formula (B-1'). In the formula, "*" represents a bond.

[0087] [ka]

[0088] In formula (B-1'), R 22 R in equation (B-1) 21 It is the same as [the other expression]. R represents a hydrogen atom or an alkoxymethyl group.

[0089] The (B) melamine resin contained in the photosensitive resin composition according to this embodiment usually contains 1 or more of the above alkoxymethyl groups per molecule. The number of alkoxymethyl groups per molecule of the (B) melamine resin is preferably 2 or more from the viewpoint of obtaining a photosensitive resin composition excellent in photosensitivity.

[0090] As the (B) melamine resin, a melamine resin having a structure represented by the following formula (B-2) is preferable.

[0091] [Chemical formula]

[0092] (In formula (B-2), X 21 , X 22 , X 23 and X 24 each independently represents a hydrogen atom or an alkoxymethyl group. R 50 represents a hydrogen atom, an amino group, an alkyl group which may have a substituent, an aryl group which may have a substituent, or an alkoxymethylamino group represented by formula (B-1'). However, when R 50 represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent, at least one of X 21 , X 22 , X 23 , and X 24 is an alkoxymethyl group.)

[0093] In formula (B-2), X 21 , X 22 , X 23 and X 24 each independently represents a hydrogen atom or an alkoxymethyl group. The alkoxymethyl group represented by X 21 ~X 24 can be the same as the group represented by formula (B-1). When R 50 represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent, X 21 ~X 24At least one, preferably two or more of them, are alkoxymethyl groups. Preferably, R 50 When represents a hydrogen atom, an amino group, an alkyl group which may have a substituent, or an aryl group which may have a substituent, X 21 ~X 24 At least one, preferably two or more of them, are alkoxymethyl groups. X 21 ~X 24 More preferably, three or more of them are alkoxymethyl groups, and particularly preferably, four or more of X 21 ~X 24 are alkoxymethyl groups.

[0094] In formula (B-2), R 50 represents a hydrogen atom, an amino group, an alkyl group which may have a substituent, an aryl group which may have a substituent, or an alkoxymethylamino group represented by formula (B-1’). R 50 is preferably an aryl group which may have a substituent, or an alkoxymethylamino group represented by formula (B-1’), and more preferably an alkoxymethylamino group represented by formula (B-1’). The alkyl group which may have a substituent and the aryl group which may have a substituent represented by R 50 may be the same as the alkyl group which may have a substituent and the aryl group which may have a substituent represented by X 3 and X 4 in formula (A-1).

[0095] The melamine resin having the structure represented by formula (B-2) is preferably a melamine resin having the structure represented by formula (B-2’).

[0096]

Chemical formula

[0097] (In formula (B-2’), X 25 、X 26 、X 27 、X 28 、X 29 and X 30Each of these independently represents either a hydrogen atom or an alkoxymethyl group. However, X 25 , X 26 , X 27 , X 28 , X 29 and X 30 At least one of them is an alkoxymethyl group.

[0098] In formula (B-2'), X 25 , X 26 , X 27 , X 28 , X 29 and X 30 Each of these independently represents either a hydrogen atom or an alkoxymethyl group. 25 ~X 30 The alkoxymethyl group represented by can be the same as the group represented by formula (B-1). 25 ~X 30 At least one, preferably two or more, of these is an alkoxymethyl group. 25 ~X 30 It is more preferable that three or more of these are alkoxymethyl groups, X 25 ~X 30 It is even more preferable that four or more of them are alkoxymethyl groups, X 25 ~X 30 It is particularly preferable that all of them are alkoxymethyl groups.

[0099] (B) Specific examples of melamine resin include the following:

[0100] [ka]

[0101] (B) Commercial melamine resin may be used. Examples of commercially available products include "MW-390", "MW-100LM", and "MX-750LM" from Sanwa Chemical Co., Ltd.; and "Cymel-300", "Cymel-370", and "Cymel-327" from Daicel Ornex Co., Ltd.

[0102] (B) Melamine resin may be used alone or in combination of two or more types.

[0103] (B) The amount of melamine resin is preferably 1% by mass or more, more preferably 5% by mass or more, even more preferably 10% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less, when the nonvolatile components of the photosensitive resin composition are considered to be 100% by mass. (B) When the amount of melamine resin is within the above range, both limiting resolution and adhesion to the GaAs substrate can be effectively improved.

[0104] (B) The amount of melamine resin is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 25% by mass or less, when the resin component of the photosensitive resin composition is taken as 100% by mass. (B) When the amount of melamine resin is within the above range, both limiting resolution and adhesion to the GaAs substrate can be effectively improved.

[0105] The ratio of the mass of (A) alkali-soluble resin to the mass of (B) melamine resin contained in the photosensitive resin composition ((B) melamine resin / (A) alkali-soluble resin) is preferably 0.01 or more, more preferably 0.1 or more, particularly preferably 0.2 or more, preferably 0.5 or less, more preferably 0.4 or less, and particularly preferably 0.3 or less.

[0106] [4. (C) Photoacid Generator] The photosensitive resin composition contains (C) a photoacid generator as component (C). The (C) photoacid generator generates acid when irradiated with active light such as ultraviolet light, and the generated acid can promote the reaction between (A) alkali-soluble resin and (B) melamine resin. Therefore, exposure can effectively reduce the solubility of the photosensitive resin composition in the developer, thereby allowing the formation of a latent image by exposure to proceed smoothly. The (C) photoacid generator may be used alone or in combination of two or more types.

[0107] (C) As the photoacid generator, a compound that generates acid upon irradiation with active light can be used. (C) Examples of photoacid generators include halogen-containing compounds, onium salt compounds, diazoketone compounds, sulfone compounds, sulfonic acid compounds, sulfonimide compounds, diazomethane compounds, oxime ester compounds, etc. Among these, halogen-containing compounds are preferred.

[0108] (C) Examples of halogen-containing compounds that can be suitably used as photoacid generators include haloalkyl group-containing hydrocarbon compounds and haloalkyl group-containing heterocyclic compounds. Suitable specific examples of halogen-containing compounds include 2-[2-(furan-2-yl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(5-methylfuran-2-yl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 2-(methoxyphenyl)-4,6-bis(trichloromethyl)-s-triazine, 2-[2-(4-methoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, and 2-[2-(3,4-dimethylphenyl] Examples of s-triazine derivatives include s-triazine derivatives such as [[Ciphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine, 1,10-dibromo-n-decane, 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane, phenyl-bis(trichloromethyl)-s-triazine, 4-methoxyphenyl-bis(trichloromethyl)-s-triazine, styryl-bis(trichloromethyl)-s-triazine, and naphthyl-bis(trichloromethyl)-s-triazine. Commercial halogen-containing compounds can be used, and examples of commercially available products include Sanwa Chemical's "TFE-triazine," "TME-triazine," "MP-triazine," "MOP-triazine," and "dimethoxytriazine" (halogen-containing compound-based photoacid generators having a triazine skeleton).

[0109] (C) Examples of onium salt compounds that can be suitably used as photoacid generators include iodonium salts, sulfonium salts, phosphonium salts, diazonium salts, pyridinium salts, and the like. Suitable examples of onium salt compounds include tris(4-methylphenyl)sulfonium trifluoromethanesulfonate, tris(4-methylphenyl)sulfonium hexafluorophosphonate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium p-toluenesulfonate, diphenyliodonium hexafluoroantimonate, diphenyliodonium hexafluorophosphate, diphenyliodonium tetrafluoroborate, triphenylsulfonium trifluilomethanesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium hexafluoroantimonate, 4-tert-butylphenyl·diphenylsulfonium trifluoromethanesulfonate, 4-tert-butylphenyl·diphenylsulfonium p-toluenesulfonate, and 4,7-di-n-butoxynaphthyltetrahydrothiophenium trifluilomethanesulfonate. Commercially available onium salt compounds can be used. Examples of commercially available products include "TS-01" and "TS-91" from Sanwa Chemical Co., Ltd.; "CPI-110A," "CPI-210S," "HS-1," "LW-S1," "IK-1," and "CPI-310B" from Sunapro Co., Ltd.; and "SI-110L," "SI-180L," and "SI-100L" from Sanshin Chemical Industry Co., Ltd.

[0110] (C) Examples of diazoketone compounds that can be suitably used as photoacid generators include 1,3-diketo-2-diazo compounds, diazobenzoquinone compounds, and diazonaphthoquinone compounds. Suitable specific examples of diazoketone compounds include 1,2-naphthoquinone diazide-4-sulfonic acid ester compounds of phenols.

[0111] (C) Suitable sulfone compounds that can be used as photoacid generators include, for example, β-ketosulfone compounds, β-sulfonylsulfone compounds, and α-diazo compounds of these compounds. Suitable specific examples of sulfone compounds include 4-trisphenacylsulfone, mesitylphenacylsulfone, and bis(phenacylsulfonyl)methane.

[0112] (C) Suitable sulfonic acid compounds that can be used as photoacid generators include, for example, alkyl sulfonic acid esters, haloalkyl sulfonic acid esters, aryl sulfonic acid esters, and iminosulfonates. Suitable specific examples of sulfonic acid compounds include benzointosylate, pyrogallol trifluoromethanesulfonate, o-nitrobenzyl trifluoromethanesulfonate, and o-nitrobenzyl p-toluenesulfonate.

[0113] (C) Specific examples of sulfonimide compounds that can be suitably used as photoacid generators include N-(trifluoromethylsulfonyloxy)succinimide, N-(trifluoromethylsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)diphenylmaleimide, N-(trifluoromethylsulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide, and N-(trifluoromethylsulfonyloxy)naphthylimide.

[0114] (C) Specific examples of diazomethane compounds that can be suitably used as photoacid generators include bis(trifluoromethylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, bis(phenylsulfonyl)diazomethane, etc. Commercially available diazomethane compounds can be used.

[0115] (C) Specific examples of oxime ester compounds that can be suitably used as photoacid generators include benzeneacetonitrile, 2-methyl-α-[2-[[(propylsulfonyl)oxy]imino]-3(2H)-thienylidene] and benzeneacetonitrile, 2-methyl-α-[2-[[[(4-methylphenyl)sulfonyl]oxy]imino]-3(2H)-thienylidene]. Commercially available products include, for example, BASF's "PAG103", "PAG121", "PAG169", and "PAG203".

[0116] (C) The amount of photoacid generator is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, preferably 3% by mass or less, more preferably 2% by mass or less, and particularly preferably 1% by mass or less, when the nonvolatile components in the photosensitive resin composition are taken as 100% by mass.

[0117] [5.(D) Silane coupling agent containing a trimethoxysilyl group] The photosensitive resin composition includes a silane coupling agent containing a trimethoxysilyl group as component (D). When the silane coupling agent containing a trimethoxysilyl group (D) is used in combination with the components (A) to (C) described above, it is possible to improve both the limiting resolution and the adhesion to the GaAs substrate.

[0118] (D) The trimethoxysilyl group contained in the silane coupling agent is represented by the formula "(CH3O)3Si-". (D) The number of trimethoxysilyl groups contained in one molecule of the silane coupling agent is usually 1, but it may be 2 or more. (D) The number of trimethoxysilyl groups per molecule of the silane coupling agent is preferably 1 to 3.

[0119] (D) Silane coupling agents typically contain an organic group in combination with the trimethoxysilyl group. This organic group does not need to be reactive. Examples of non-reactive organic groups include monovalent or divalent or more saturated hydrocarbon groups (e.g., alkyl groups such as methyl, ethyl, propyl, pentylene, and octyl groups; alkylene groups such as methylene, ethylene, propylene, pentylene, and octylene groups), and monovalent or divalent or more aromatic hydrocarbon groups (e.g., aryl groups such as phenyl and naphthyl groups; arylene groups such as phenylene and naphthylene groups).

[0120] Furthermore, the organic group may be reactive. For example, the organic group may include a functional group that can react with a suitable organic compound to form a chemical bond. Examples of such functional groups include vinyl groups, epoxy groups, styryl groups, acryloyl groups, methacryloyl groups, amino groups, ureido groups, isocyanate groups, isocyanurate groups, mercapto groups, and acid anhydride groups. Among these, vinyl groups, epoxy groups, and isocyanurate groups are preferred. These functional groups may be used individually or in combination of two or more.

[0121] The functional group may be directly bonded to the silicon atom of the trimethoxysilyl group, or it may be bonded via an appropriate linking group. For example, the organic group may contain a linking group, and the functional group may be bonded to the silicon atom via that linking group. Examples of linking groups include, but are not limited to, alkylene groups such as methylene, propylene, and hexylene groups; alkylene oxy groups such as methylene oxy and ethylene oxy groups; and alkylene oxyalkylene groups such as methylene oxymethylene, propylene oxymethylene, and octylene oxymethylene groups.

[0122] From the viewpoint of effectively improving adhesion to the GaAs substrate, it is preferable that the mass percentage of Si atoms contained in the molecule of (D) the silane coupling agent is within a specific range. Specifically, the mass percentage is preferably 11.5% by mass or more, and more preferably 11.8% by mass or more.

[0123] (D) Examples of silane coupling agents include alkoxysilane coupling agents such as 1,2-bis(trimethoxysilyl)ethane; vinyl group-containing silane coupling agents such as vinyltrimethoxysilane and 7-octenyltrimethoxysilane; epoxy group-containing silane coupling agents such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 8-glycidoxyoctyltrimethoxysilane; and p-styryltrimethoxysilane. Styryl group-containing silane coupling agents; methacryloyl group-containing silane coupling agents such as 3-methacryloxypropyltrimethoxysilane and 8-methacryloxyoctyltrimethoxysilane; acryloyl group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane; N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-(vinylbenzyl)-2- aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, N-2-(aminoethyl)-8-aminooctyltrimethoxysilane, and other amino group-containing silane coupling agents; ureido group-containing silane coupling agents such as 3-ureidopropyltrimethoxysilane; isocyanate group-containing silane coupling agents such as 3-isocyanatetopropyltrimethoxysilane; tris-(trimethoxysilylpropyl)isocyanurate, 1,3-diallyl-5-(3-(trimethoxysilyl)propyl) Examples include isocyanurate group-containing silane coupling agents such as -1,3,5-triazinan-2,4,6-trione; mercapto group-containing silane coupling agents such as 3-mercaptopropyltrimethoxysilane, mercaptomethyltrimethoxysilane, 2-mercaptoethyltrimethoxysilane, and 4-mercaptobutyltrimethoxysilane; acid anhydride group-containing silane coupling agents such as 3-trimethoxysilylpropyl succinic anhydride; and N-(3-trimethoxysilylpropyl)urea.

[0124] (D) Commercially available silane coupling agents may be used. (D) Examples of commercially available silane coupling agents include "KBM-1003" (vinyltrimethoxysilane), "KBM-1083" (7-octenyltrimethoxysilane), "KBM-303" (2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane), "KBM-403" (3-glycidoxypropyltrimethoxysilane), "KBM-4803" (8-glycidoxyoctyltrimethoxysilane), and "KBM-1403" manufactured by Shin-Etsu Chemical Co., Ltd. p-styryltrimethoxysilane), "KBM-503" (3-methacryloxypropyltrimethoxysilane), "KBM-5803" (8-methacryloxyoctyltrimethoxysilane), "KBM-5103" (3-acryloxypropyltrimethoxysilane), "KBM-603" (N-2-(aminoethyl)-3-aminopropyltrimethoxysilane), "KBM-903" (3-aminopropyltrimethoxysilane), "KBM-573" (N-phenyl- 3-aminopropyltrimethoxysilane), "KBM-575" (N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride), "KBM-6803" (N-2-(aminoethyl)-8-aminooctyltrimethoxysilane), "KBM-9659" (tris-(trimethoxysilylpropyl)isocyanurate), "X-12-1290" (1,3-diallyl-5-(3-(trimethoxysilyl)propyl)-1,3,5-tri Examples include dinan-2,4,6-trione), "KBM-803" (3-mercaptopropyltrimethoxysilane), "X-12-967C" (3-trimethoxysilylpropyl succinic anhydride); "Sira Ace S810" (3-mercaptopropyltrimethoxysilane) manufactured by Chisso Corporation; "SIM6473.5C" (mercaptomethyltrimethoxysilane) manufactured by Azmax Corporation; and "SIU9058.0" (N-(3-trimethoxysilylpropyl)urea).

[0125] (D) The silane coupling agent may be used alone or in combination of two or more types.

[0126] (D) The amount of the silane coupling agent is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 1.5% by mass or more, preferably 20% by mass or less, more preferably 18% by mass or less, and even more preferably 15% by mass or less, when the nonvolatile components of the photosensitive resin composition are considered to be 100% by mass. (D) When the amount of the silane coupling agent is within the above range, both critical resolution and adhesion to the GaAs substrate can be effectively improved.

[0127] (D) The amount of silane coupling agent is preferably 0.1% by mass or more, more preferably 1% by mass or more, even more preferably 1.5% by mass or more, preferably 20% by mass or less, more preferably 18% by mass or less, and even more preferably 15% by mass or less, when the resin component of the photosensitive resin composition is considered to be 100% by mass. (D) When the amount of silane coupling agent is within the above range, both critical resolution and adhesion to the GaAs substrate can be effectively improved.

[0128] (D) Mass W of the silane coupling agent D (A) Mass W of alkali-soluble resin A and (B) the mass W of the melamine resin B Total W A +W B Ratio to (W D / (W A +W B )) is preferably 0.01 or more, more preferably 0.015 or more, even more preferably 0.02 or more, preferably 0.5 or less, more preferably 0.3 or less, and particularly preferably 0.2 or less.

[0129] [6.(E) Organic filler] The photosensitive resin composition may further contain fillers as optional components in combination with the components (A) to (D) described above. Fillers are usually immiscible with the resin components and may exist as particles in the photosensitive resin composition and its cured product. The photosensitive resin composition preferably contains (E) an organic filler as this filler.

[0130] (E) Organic fillers are formed from organic materials and therefore generally possess flexibility. Consequently, when using (E) organic fillers, it becomes possible to distribute stress in the insulating layer, thereby improving the crack resistance and insulating properties of the insulating layer. Examples of (E) organic fillers include urethane particles, rubber particles, polyamide particles, and silicone particles.

[0131] Commercially available urethane particles may be used, such as "MM-101SW," "MM-101SWA," "MM-101SM," "MM-101SMA," and "MM-110SMA" from Negami Kogyo Co., Ltd.; and the RKB series from Reginas Kasei Co., Ltd.

[0132] As rubber particles, resin particles can be made by chemically crosslinking a resin that exhibits rubber elasticity, thereby making them insoluble and infusible in organic solvents. Examples of rubber particles include acrylonitrile butadiene rubber particles, butadiene rubber particles, acrylic rubber particles, and methyl methacrylate-butadiene-styrene copolymer particles. Commercially available rubber particles may be used, for example, "EXL-2655" from Dow Chemical Japan; "AC3816N", "AC3355", "AC3816", "AC3832", "AC4030", "AC3364", and "IM101" from Gantz Chemical Co., Ltd.; "Paraloid EXL2655" and "EXL2602" from Kureha Chemical Co., Ltd.; "B-11A", "B513", "B22", "B-521", "B-561", "B-564", "FM-21", "FM-40", "FM-50", "M-701", "M-711", "M-732", "M-300", "FM-40", "M-570", and "M-210" from Kaneka Corporation; and the RKB series from Reginas Chemical Co., Ltd.

[0133] As polyamide particles, resin particles having amide bonds can be used. Examples of polyamide particles include aliphatic polyamide particles such as nylon, aromatic polyamide particles such as Kevlar, and polyamide-imide particles. Commercially available polyamide particles may also be used, such as "VESTOSINT 2070" from Daicel-Hürss and "SP500" from Toray Industries.

[0134] (E) Organic fillers may be used individually or in combination of two or more types.

[0135] (E) The average particle size of the organic filler is preferably 0.005 μm or more, more preferably 0.01 μm or more, even more preferably 0.05 μm or more, preferably 5 μm or less, more preferably 2 μm or less, even more preferably 1 μm or less, and particularly preferably 0.5 μm or less. The average particle size of the organic filler can be measured using dynamic light scattering. Specifically, the average particle size of the organic filler can be measured by uniformly dispersing the organic filler in a suitable organic solvent using ultrasound, creating a particle size distribution of the organic filler on a mass basis using a concentrated particle size analyzer (for example, "FPAR-1000" manufactured by Otsuka Electronics Co., Ltd.), and taking the median diameter as the average particle size.

[0136] (E) The amount of organic filler may be 0% by mass or more than 0% by mass when the nonvolatile components of the photosensitive resin composition are taken as 100% by mass, but is preferably 3% by mass or more, more preferably 5% by mass or more, even more preferably 7% by mass or more, preferably 40% by mass or less, more preferably 35% by mass or less, and even more preferably 30% by mass or less. (E) When the amount of organic filler is within the above range, both limiting resolution and adhesion to the GaAs substrate can be effectively improved.

[0137] [7. (F) Any additives] The photosensitive resin composition may further contain (F) any additive as an optional nonvolatile component in combination with the nonvolatile components such as components (A) to (E) described above. Examples of additives as component (F) include thermoplastic resins; inorganic fillers such as silica particles and alumina particles; colorants such as phthalocyanine blue, phthalocyanine green, iodine green, diazo yellow, crystal violet, titanium dioxide, carbon black, and naphthalene black; polymerization inhibitors such as hydroquinone, phenothiazine, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol; thickeners such as bentonite and montmorillonite; silicone-based, fluorine-based, and vinyl resin-based defoamers; flame retardants such as epoxy resins, antimony compounds, phosphorus compounds, aromatic condensed phosphate esters, and halogen-containing condensed phosphate esters; and thermosetting resins such as phenol-based curing agents and cyanate ester-based curing agents. Additive (F) may be used alone or in combination of two or more types.

[0138] [8. (G) Solvent] The photosensitive resin composition may contain a volatile component, solvent (G), in combination with the non-volatile components such as components (A) to (F) described above. The viscosity of the photosensitive resin composition can be adjusted depending on the solvent (G) used as component (G). Examples of solvent (G) include organic solvents.

[0139] (G) Examples of solvents include ketone solvents such as ethyl methyl ketone and cyclohexanone; aromatic hydrocarbon solvents such as toluene, xylene, and tetramethylbenzene; glycol ether solvents such as methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, and triethylene glycol monoethyl ether; ester solvents such as ethyl acetate, butyl acetate, butyl cellosolve acetate, carbitol acetate, and ethyl diglycol acetate; aliphatic hydrocarbon solvents such as octane and decane; and petroleum-based solvents such as petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha. One type of solvent may be used alone, or two or more types may be used in combination.

[0140] The amount of (G) solvent may be 0% by mass or more than 0% by mass when the entire photosensitive resin composition including (G) solvent is considered to be 100% by mass, preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 15% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, and even more preferably 40% by mass or less. The content of (G) solvent in the photosensitive resin composition layer of the photosensitive film is preferably 0.5% by mass or more, more preferably 1% by mass or more, even more preferably 2% by mass or more, preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less when the entire photosensitive resin composition including (G) solvent is considered to be 100% by mass.

[0141] [9. Method for producing a photosensitive resin composition] The method for producing the photosensitive resin composition is not particularly limited. The photosensitive resin composition can be produced, for example, by mixing components (A) to (D) and, if necessary, components (E) to (G). During mixing, kneading may be performed using a kneading device such as a three-roll mill, ball mill, bead mill, or sand mill, or stirring may be performed using a stirring device such as a super mixer or planetary mixer, as needed. There are no restrictions on the order in which the components are mixed. Furthermore, cooling or heating may be performed during the mixing process of each component.

[0142] [10. Properties and Uses of Photosensitive Resin Compositions] The photosensitive resin composition according to this embodiment can have a low limiting resolution. Therefore, by using this photosensitive resin composition, an insulating layer having small openings can be formed. In one example, a photosensitive resin composition layer with a dry thickness of 20 μm is formed using the photosensitive resin composition, and an insulating layer having via holes is formed from the photosensitive resin composition layer using the method described in the examples. In this case, the minimum via hole opening diameter that can be properly formed in the insulating layer can be reduced. Specifically, the opening diameter can be preferably 25 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less.

[0143] The photosensitive resin composition according to this embodiment can produce a cured product that adheres to a GaAs substrate with high adhesion. Therefore, by using this photosensitive resin composition, an insulating layer that adheres to a GaAs substrate with high adhesion can be formed. In one example, a photosensitive resin composition layer is formed on a GaAs substrate by the method described in the example, and cured to form an insulating layer. When a cross-cut tape peel test is performed on this insulating layer in accordance with JIS K5600-5-6:1999 (ISO2409:1992), preferably a result of classification "0" to "2" in Table 1 of JIS K5600-5-6:1999 8.3 can be obtained, more preferably a result of classification "0" to "1", and particularly preferably a result of classification "0". The classification indicates that the smaller the numerical value, the better the adhesion. Specifically, classification "0" indicates that the cut edge is completely smooth and there is no peeling at any of the grid lines. Furthermore, classification "1" indicates that there is small paint peeling at the intersections of the cuts, but the affected area in the cross-cuts does not clearly exceed 5%. In addition, classification "2" indicates that the paint peels along the edges of the cuts and / or at the intersections, but the affected area in the cross-cuts is clearly more than 5% but does not exceed 15%.

[0144] Typically, the photosensitive resin composition according to this embodiment can produce a cured product that adheres with high adhesion to a conductive layer such as copper foil. Therefore, by using this photosensitive resin composition, an insulating layer that adheres with high adhesion to a conductive layer can be formed. In one example, a photosensitive resin composition layer is formed on copper foil by the method described in the example, and then cured to form an insulating layer. In this case, the load required to peel the copper foil from the insulating layer (peel strength) can be made 0.4 kgf or more per 10 mm width.

[0145] The applications of the photosensitive resin composition described above are not particularly limited, and it can be used in a wide range of applications, such as photosensitive films, insulating resin sheets such as prepregs; layering materials for circuit boards (laminated board applications, multilayer printed wiring board applications, etc.); solder resists, buffer coat films, underfill materials, die bonding materials, semiconductor encapsulants, hole-filling resins, and component embedding resins. In particular, from the viewpoint of taking advantage of the benefit of being able to form an insulating layer that adheres with high adhesion to a GaAs substrate, the photosensitive resin composition is preferably used as a material for forming an insulating layer on a GaAs substrate, and more preferably as a material for the insulating layer of a circuit board equipped with a GaAs substrate.

[0146] Examples of circuit boards comprising a GaAs substrate include semiconductor chip packages comprising a GaAs substrate, such as multi-chip packages, package-on-packages, wafer-level packages, panel-level packages, and system-in-packages; package substrates comprising the aforementioned semiconductor chip packages; and printed wiring boards comprising a GaAs substrate, such as rigid substrates, flexible substrates, single-area layer substrates, thin substrates, and component-embedded substrates. Among these, the photosensitive resin composition is particularly suitable for wafer-level packages comprising a GaAs wafer. Examples of wafer-level packages include fan-in type wafer-level packages and fan-out type wafer-level packages, and either type may be applied.

[0147] In a circuit board, the insulating layer formed from the photosensitive resin composition may be an insulating layer for forming a wiring layer on top of it. Alternatively, the insulating layer formed from the photosensitive resin composition may be an interlayer insulating layer. Furthermore, the insulating layer formed from the photosensitive resin composition may be a solder resist. Also, the insulating layer formed from the photosensitive resin composition may be a buffer coat film. Since the insulating layer formed from the above-described photosensitive resin composition can usually adhere to both the GaAs substrate and the conductor layer with high adhesion, it is preferable to use it for forming an insulating layer at a location that contacts the GaAs substrate and the conductor layer.

[0148] [11. Photosensitive film] A photosensitive film according to one embodiment of the present invention comprises a support and a photosensitive resin composition layer formed on the support. Since the photosensitive resin composition layer is formed of a photosensitive resin composition, it contains a photosensitive resin composition, and usually contains only a photosensitive resin composition.

[0149] Examples of support materials include polyethylene terephthalate film, polyethylene naphthalate film, polypropylene film, polyethylene film, polyvinyl alcohol film, and triacetyl acetate film, with polyethylene terephthalate film being particularly preferred.

[0150] Examples of commercially available supports include polypropylene films such as "Alfan MA-410" and "E-200C" from Oji Paper Co., Ltd., and polyethylene terephthalate films such as the PS series "PS-25" from Teijin Corporation. To facilitate the removal of the support, a release agent such as a silicone coating agent may be applied to the surface of the support. An example of a support whose surface has been treated with a release agent is "AL-5" from Lintec Corporation. The thickness of the support is preferably in the range of 5 μm to 100 μm, and more preferably in the range of 10 μm to 50 μm.

[0151] The thickness of the photosensitive resin composition layer is not particularly limited and can be, for example, 1 μm or more and 100 μm or less. Preferably, it is 2 μm or more, more preferably 4 μm or more, preferably 50 μm or less, and more preferably 30 μm or less.

[0152] The photosensitive film may include a protective film to protect the photosensitive resin composition layer. Typically, the protective film is provided on the side opposite the support to the photosensitive resin composition layer. As the protective film, for example, a film made of the same material as the support may be used. It is preferable that the adhesion force between the protective film and the photosensitive resin composition layer is less than the adhesion force between the support and the photosensitive resin composition layer. Typically, the photosensitive film is used after the protective film has been removed.

[0153] A photosensitive film can be manufactured, for example, by coating a photosensitive resin composition onto a support. From the viewpoint of smooth coating, a varnish-like photosensitive resin composition containing a solvent may be prepared and this varnish-like photosensitive resin composition may be applied. When a photosensitive resin composition containing a solvent is applied, drying may be performed after coating as needed.

[0154] The photosensitive resin composition layer of the photosensitive film may or may not contain a solvent, but it is preferable that the amount of solvent be small. The preferred range for the amount of solvent in the photosensitive resin composition layer is as described above.

[0155] [12. Circuit board] A circuit board according to one embodiment of the present invention comprises an insulating layer containing a cured product of the photosensitive resin composition described above. Preferably, this insulating layer contains only the cured product of the photosensitive resin composition. The insulating layer can adhere to the GaAs substrate with high adhesion, so it is preferable to provide it on the GaAs substrate. Therefore, the circuit board preferably comprises a GaAs substrate and an insulating layer formed on the GaAs substrate. In this circuit board, the GaAs substrate and the insulating layer are normally in contact. Furthermore, from the viewpoint of taking advantage of the low critical resolution, it is preferable that openings are formed in the insulating layer by exposure and development.

[0156] The above-mentioned photosensitive resin composition can be used as a negative-type photosensitive resin composition. Therefore, the circuit board can be, for example, (I) A step of forming a photosensitive resin composition layer on a GaAs substrate. (II) A step of exposing the photosensitive resin composition layer, (III) A step of developing the photosensitive resin composition layer, It can be manufactured by a manufacturing method that includes these elements in this order.

[0157] Furthermore, the above manufacturing method may include any additional steps. For example, the manufacturing method may include a step (IV) of heating the photosensitive resin composition layer between step (II) and step (III). Also, the manufacturing method may include a step (V) of further exposure of the photosensitive resin composition layer after step (III). Furthermore, the manufacturing method may include a step (VI) of heat treatment of the photosensitive resin composition layer after step (III). Also, the manufacturing method may include a step (VII) of forming a conductive layer on the insulating layer. The manufacturing method will now be described in detail.

[0158] [12.1. Process (I)] The method for manufacturing a circuit board according to this embodiment includes a step (I) of forming a photosensitive resin composition layer on a GaAs substrate. Since the photosensitive resin composition layer is formed by a photosensitive resin composition, it contains a photosensitive resin composition, and usually contains only a photosensitive resin composition.

[0159] A substrate containing gallium arsenide is used as the GaAs substrate. A gallium arsenide wafer can be used as this GaAs substrate. Typically, the wafer is prepared as a disc, but the shape of the wafer is not limited to a disc. The wafer may also have a conductive layer, and this conductive layer may be patterned.

[0160] There are no particular restrictions on the method for forming the photosensitive resin composition layer. For example, the photosensitive resin composition layer may be formed by coating the photosensitive resin composition onto a GaAs substrate. From the viewpoint of smooth coating, a varnish-like photosensitive resin composition containing a solvent may be prepared and this varnish-like photosensitive resin composition may be applied.

[0161] Examples of coating methods include gravure coating, microgravure coating, reverse coating, kiss reverse coating, die coating, slot die coating, lip coating, comma coating, blade coating, roll coating, knife coating, curtain coating, chamber gravure coating, slot orifice coating, spin coating, slit coating, spray coating, dip coating, hot melt coating, bar coating, applicator coating, air knife coating, curtain flow coating, offset printing, brush coating, and screen printing.

[0162] The photosensitive resin composition may be applied in a single application or in multiple applications. Alternatively, different application methods may be combined. To avoid contamination, application is preferably carried out in an environment with minimal foreign matter generation, such as a cleanroom.

[0163] After coating the photosensitive resin composition, the photosensitive resin composition layer may be dried as needed. Drying can be performed using a drying device such as a hot air furnace or a far-infrared furnace. The drying conditions are preferably set appropriately according to the composition of the photosensitive resin composition. Specifically, the drying temperature is preferably 50°C or higher, more preferably 70°C or higher, particularly preferably 80°C or higher, preferably 150°C or lower, more preferably 130°C or lower, and particularly preferably 120°C or lower. The drying time is preferably 30 seconds or more, more preferably 60 seconds or more, particularly preferably 120 seconds or more, preferably 60 minutes or less, more preferably 20 minutes or less, and particularly preferably 5 minutes or less.

[0164] The photosensitive resin composition layer may be formed, for example, using a photosensitive film. Specifically, a photosensitive resin composition layer can be formed on a GaAs substrate by laminating the photosensitive resin composition layer of a photosensitive film onto a GaAs substrate. Lamination is usually performed by pressing the photosensitive resin composition layer of the photosensitive film onto the GaAs substrate while heating it. This lamination is preferably performed under reduced pressure using a vacuum lamination method. Alternatively, a preheating treatment may be performed on the photosensitive film and the GaAs substrate before lamination, if necessary.

[0165] Lamination conditions include, for example, a bonding temperature of 70°C to 140°C and a bonding pressure of 1 kgf / cm². 2 ~11 kgf / cm² 2 (9.8 × 10 4 N / m 2 ~107.9×10 4 N / m 2 The lamination can be carried out under conditions of a crimping time of 5 to 300 seconds. Furthermore, it is preferable to perform the lamination under reduced pressure with an air pressure of 20 mmHg (26.7 hPa) or less. Lamination may be carried out in a batch manner or in a continuous manner using a roll.

[0166] Vacuum lamination can be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include the vacuum applicator manufactured by Nikko Materials, the vacuum pressure laminator manufactured by Meiki Seisakusho, the roll-type dry coater manufactured by Hitachi Industries, and the vacuum laminator manufactured by Hitachi AIC.

[0167] When a photosensitive resin composition layer is formed using a photosensitive film, the support is usually peeled off at an appropriate time prior to step (III).

[0168] [12.2. Process (II)] The method for manufacturing a circuit board according to this embodiment includes a step (II) of exposing a photosensitive resin composition layer after step (I). In step (II), the photosensitive resin composition layer is usually irradiated with active light to form a latent image in the photosensitive resin composition layer. Specifically, in step (II), active light is selectively irradiated onto a specific portion of the photosensitive resin composition layer. As a result, the photosensitive resin composition layer is divided into exposed areas irradiated with active light and unexposed areas that have not been irradiated with active light. The unexposed areas then form a latent image corresponding to the aperture.

[0169] As the active light, it is preferable to use a light appropriate to the composition of the photosensitive resin composition. The wavelength of the active light is usually 190 nm to 1000 nm, preferably 240 nm to 550 nm, but other wavelengths of light may also be used. Specific examples of active light sources include ultraviolet light, visible light, electron beams, X-rays, etc., with ultraviolet light being particularly preferred.

[0170] The irradiation dose of the active light is preferably set so that the desired aperture can be formed after development. In one example, the specific irradiation dose range is preferably 10 mJ / cm². 2 More specifically, 50 mJ / cm² 2 The above is particularly preferably 200 mJ / cm². 2 The above is preferable, preferably 10,000 mJ / cm². 2 More preferably, 8,000 mJ / cm² 2 The following is particularly preferred: 1,000 mJ / cm² 2 The following applies:

[0171] Irradiation with active light is usually performed using a mask. Specifically, active light is irradiated onto the photosensitive resin composition layer through a mask that has light-transmitting and light-blocking portions. The active light passes through the light-transmitting portions and enters the exposed portions, but it cannot pass through the light-blocking portions and therefore cannot enter the unexposed portions. Thus, exposed and unexposed portions corresponding to the light-transmitting and light-blocking portions can be provided in the photosensitive resin composition layer. The mask may be in close contact with the photosensitive resin composition layer (contact exposure method), or exposure may be performed using parallel light without contact (non-contact exposure method).

[0172] Generally, the light-shielding portion of a mask is formed to have a planar shape corresponding to the opening to be formed in the insulating layer. Unless otherwise specified, "planar shape" refers to the shape viewed from the thickness direction. The light-shielding portion having a planar shape corresponding to the opening in the insulating layer may be referred to as the "mask pattern" below. In one example, a via pattern such as a circular hole pattern may be used as the mask pattern. The via diameter (opening diameter) is preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less. The lower limit is not particularly limited, but can be 0.1 μm or more, 0.5 μm or more, etc.

[0173] If a support is present on the photosensitive resin composition layer, exposure may be performed through the support, or exposure may be performed after the support has been removed.

[0174] [12.3. Process (IV)] The method for manufacturing a circuit board according to this embodiment may include a step (IV) of heating the photosensitive resin composition layer after step (II) and before step (III). Heating in step (IV) can promote the crosslinking reaction between (A) the alkali-soluble resin and (B) the melamine resin, thereby rapidly reducing the solubility of the exposed area in the developer.

[0175] The heating temperature in step (IV) may be achieved using a hot plate or an oven. The heating temperature may be, for example, between 40°C and 115°C. The heating time may be, for example, between 30 seconds and 60 minutes. In particular, when heating is performed using a hot plate, the heating temperature is preferably 50°C or higher, more preferably 60°C or higher, especially preferably 70°C or higher, preferably 115°C or lower, more preferably 110°C or lower, and especially preferably 105°C or lower. The heating time is preferably 30 seconds or more, more preferably 60 seconds or more, especially preferably 120 seconds or more, preferably 30 minutes or less, more preferably 20 minutes or less, and especially preferably 10 minutes or less. Furthermore, when heating is performed in an oven, the heating temperature is preferably 40°C or higher, more preferably 50°C or higher, preferably 100°C or lower, and more preferably 90°C or lower. The heating time is preferably 3 minutes or more, more preferably 10 minutes or more, particularly preferably 15 minutes or more, preferably 60 minutes or less, more preferably 50 minutes or less, and particularly preferably 40 minutes or less.

[0176] [12.4. Process (III)] The method for manufacturing a circuit board according to this embodiment includes a step (III) of developing the photosensitive resin composition layer after step (II). Development allows for the removal of unexposed areas that were not exposed in step (II), thereby forming openings. Development is usually performed by a wet development method, in which the photosensitive resin composition layer is brought into contact with a developer. Examples of developers include alkaline aqueous solutions, aqueous developers, and organic solvents.

[0177] Examples of alkaline aqueous solutions used as developing solutions include aqueous solutions of alkali metal compounds. Examples of alkali metal compounds include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; alkali metal carbonates or bicarbonates such as sodium carbonate and sodium bicarbonate; alkali metal phosphates such as sodium phosphate and potassium phosphate; and alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate. Examples of alkaline aqueous solutions include aqueous solutions of organic bases that do not contain metal ions, such as tetraalkylammonium hydroxide. One type of alkaline aqueous solution may be used alone, or two or more types may be used in combination. Among these, an aqueous solution of tetramethylammonium hydroxide (TMAH) is preferred because it does not contain metal ions and has little effect on semiconductor chips. The pH of the alkaline aqueous solution is preferably in the range of 8 to 14. The base concentration of the above alkaline aqueous solution is preferably 0.1% to 10% by mass.

[0178] Examples of the organic solvent as the developer include acetone, ethyl acetate, alkoxyethanol having an alkoxy group with 1 to 4 carbon atoms, ethyl alcohol, isopropyl alcohol, butyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and the like. The organic solvent may be used alone or in combination of two or more. The concentration of the organic solvent is usually 2% by mass or more, preferably 50% by mass or more, more preferably 70% by mass or more, and particularly preferably 90% by mass or more based on the total amount of the developer. The developer may be 100% by mass of the organic solvent. Examples of the organic solvent-based developer that can be used alone include 1,1,1-trichloroethane, N-methylpyrrolidone, N,N-dimethylformamide, cyclohexanone, methyl isobutyl ketone, and γ-butyrolactone.

[0179] The developer may contain additives such as a surfactant and an antifoaming agent as necessary to improve the developing action.

[0180] The developing time is preferably 10 seconds to 5 minutes. The temperature of the developer during development is not particularly defined, but is preferably 20°C or higher, preferably 50°C or lower, and more preferably 40°C or lower.

[0181] Examples of the developing method include a paddle method, a spray method, a dipping method, a brushing method, a slapping method, an ultrasonic method, and the like.

[0182] After development using the developer, rinsing of the photosensitive resin composition layer may be further performed. The rinsing is preferably performed with a solvent different from the developer. For example, rinsing may be performed using the same type of solvent as contained in the photosensitive resin composition. The rinsing time is preferably 5 seconds to 1 minute.

[0183] [12.5. Step (V)] Although an insulating layer may be obtained by curing the photosensitive resin composition layer through the above-described steps, from the perspective of further promoting the curing of the photosensitive resin composition layer to obtain an insulating layer with excellent mechanical strength, the method for manufacturing a circuit board according to this embodiment may include, after step (III), a step (V) of further exposing the photosensitive resin composition layer. In this step (V), the photosensitive resin composition layer is irradiated with actinic rays. As the actinic rays used for the exposure in step (V), the same actinic rays as those used for the exposure in step (II) can be used.

[0184] The irradiation amount of the actinic rays in step (V) is preferably set so that a desired opening can be formed after development. In one example, the specific range of the irradiation amount is preferably 500 mJ / cm 2 or more, more preferably 800 mJ / cm 2 or more, particularly preferably 1000 mJ / cm 2 or more, and preferably 10,000 mJ / cm 2 or less, more preferably 8,000 mJ / cm 2 or less, particularly preferably 6,000 mJ / cm 2 or less.

[0185] [12.6. Step (VI)] Although an insulating layer may be obtained by curing the photosensitive resin composition layer through the above-described steps, from the perspective of further promoting the curing of the photosensitive resin composition layer to obtain an insulating layer with excellent mechanical strength, the method for manufacturing a circuit board according to this embodiment preferably includes, after step (III), a step (VI) of subjecting the photosensitive resin composition layer to a heat treatment. When the method for manufacturing a circuit board includes step (V), step (VI) is preferably performed after step (V).

[0186] The heat treatment can be carried out using a heating device such as a clean oven. The atmosphere during the heat treatment may be in air or in an inert gas atmosphere such as nitrogen. The heat treatment conditions may also be selected according to the type and amount of resin components in the photosensitive resin composition, preferably in the range of 150°C to 250°C for 20 minutes to 180 minutes, and more preferably in the range of 160°C to 230°C for 30 minutes to 120 minutes.

[0187] [12.7. Process (VII)] The method for manufacturing a circuit board according to this embodiment may include a step (VII) of forming a conductive layer on an insulating layer. The conductive material used for the conductive layer is not particularly limited. For example, the conductive layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductive layer may be a single-metal layer or an alloy layer. Examples of alloy layers include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloy, copper-nickel alloy, and copper-titanium alloy). In particular, from the viewpoint of versatility in conductor layer formation, cost, and ease of patterning, single metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or alloy layers of nickel-chromium alloy, copper-nickel alloy, or copper-titanium alloy are preferred, single metal layers of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or alloy layers of nickel-chromium alloy are more preferred, and single metal layers of copper are even more preferred.

[0188] The conductor layer may have a single-layer structure, or it may have a multi-layer structure comprising two or more single-metal layers or alloy layers made of different types of metals or alloys. When the conductor layer has a multi-layer structure, the layer in contact with the insulating layer is preferably a single-metal layer of chromium, zinc, or titanium, or an alloy layer of nickel-chromium alloy.

[0189] The thickness of the conductor layer depends on the circuit board design, but is typically 3 μm to 35 μm, preferably 5 μm to 30 μm.

[0190] There are no restrictions on the method of forming the conductive layer. The conductive layer may be formed, for example, by sputtering. Alternatively, the conductive layer may be formed by a combination of electroless plating and electrolytic plating. Furthermore, the conductive layer may be formed by forming a plating resist with a pattern in the reverse of that of the conductive layer and using only electroless plating.

[0191] In particular, the conductive layer is preferably formed by sputtering. When forming the conductive layer by sputtering, typically a conductive seed layer is formed on the insulating layer by sputtering, and then a conductive sputtered layer is formed on the conductive seed layer by further sputtering. Alternatively, the surface of the insulating layer may be cleaned by reverse sputtering before forming the conductive seed layer by sputtering. Preferred gases for reverse sputtering are Ar gas, O2 gas, and N2 gas. Sputtering can be performed using various sputtering devices such as magnetron sputtering and mirrortron sputtering. Examples of metals used to form the conductive seed layer include Cr, Ni, Ti, and nichrome. Cr and Ti are particularly preferred. The thickness of the conductive seed layer is preferably 5 nm or more, more preferably 10 nm or more, preferably 1000 nm or less, and more preferably 500 nm or less. Examples of metals used to form the conductive sputtered layer include Cu, Pt, Au, and Pd. Cu is particularly preferred. The thickness of the conductor sputtered layer is preferably 50 nm or more, more preferably 100 nm or more, preferably 3000 nm or less, and more preferably 1000 nm or less.

[0192] A copper plating layer may be further formed on the layer formed by sputtering by electrolytic copper plating. The thickness of the copper plating layer is preferably 5 μm or more, more preferably 8 μm or more, preferably 75 μm or less, and more preferably 35 μm or less.

[0193] Pattern formation may be performed on the conductive layer. For example, methods such as the subtractive method and the semi-additive method can be used for pattern formation.

[0194] [12.8. Optional Steps] The method for manufacturing a circuit board according to this embodiment may include any additional steps in combination with the steps described above. For example, a method for manufacturing a circuit board may include a step of drilling holes in the insulating layer. The holes formed may be trenches that do not penetrate the insulating layer, via holes that penetrate only the insulating layer, or through-holes that penetrate the entire circuit board. Drilling can be performed by methods such as drilling, laser, or plasma.

[0195] Furthermore, the method for manufacturing the circuit board may include a step of performing a desmear treatment on the insulating layer. When holes are drilled in the insulating layer, resin residue (smear) may adhere to the formed holes. Desmear treatment removes this smear. Desmear treatment may be performed by dry desmear treatment, wet desmear treatment, or a combination thereof.

[0196] Furthermore, the method for manufacturing the circuit board may include a step of dicing the manufactured circuit board.

[0197] The method for manufacturing a circuit board may involve repeatedly performing the steps described above. For example, steps (I) to (VII) may be repeated to manufacture a multilayer circuit board having alternating insulating and conductive layers on a GaAs substrate.

[0198] [13. Semiconductor Equipment] The aforementioned circuit board can be used in the manufacture of semiconductor devices. Examples of semiconductor devices include various types of semiconductor devices that are equipped with a circuit board and are used in electrical products (e.g., computers, mobile phones, digital cameras, and televisions) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft). [Examples]

[0199] Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "mass %", respectively, unless otherwise specified. Also, the operations described below were carried out in the air at normal temperature and pressure (23 °C, 1 atm) unless otherwise specified.

[0200] [Examples 1 to 17 and Comparative Examples 1 to 6] Reagents ((Component (A-1), Component (A-2), Component (B), Component (B'), Component (C), Component (D), Component (D'), and Component (E))) and 2-butanone (MEK) in the amounts (parts by mass) shown in Tables 1 and 2 below were mixed to produce a photosensitive resin composition. In the following table, the meanings of the abbreviations of the reagents are as follows.

[0201] Component (A): Component (A-1): · BisE: "BisE" manufactured by Honshu Chemical Co., Ltd. · BisA: "BisA" manufactured by Mitsui Chemicals Fine Co., Ltd. · BisP-HTG: "BisP-HTG" manufactured by Honshu Chemical Co., Ltd. · BisP-M: "BisP-M" manufactured by Mitsui Chemicals Fine Co., Ltd.

[0202]

Chemical formula

[0203] Component (A-2): · TR4020G: Cresol novolak resin "TR4020G" manufactured by Asahi Organic Materials Co., Ltd.

[0204] [[ID=4.]

Chemical formula

[0205] Component (B): · Cymel-300: "Cymel-300" manufactured by Daicel Ornex Co., Ltd. A compound in which R represents a methyl group in the following formula (B-X). • Cymel-370N: Cymel-370N manufactured by Daicel Ornex Co., Ltd. A compound in which R represents a methyl group or a hydrogen atom in the following formula (BX). • Cymel-327: Cymel-327 manufactured by Daicel Ornex. In the following formula (BX), R represents a methyl group, and some of the -CH2OR groups are replaced by hydrogen atoms. Therefore, some of the -N(CH2OR)2 bonded to the triazine ring are replaced by the group represented by the following formula (b-1). In formula (b-1), * represents a bond.

[0206] [ka]

[0207] (B') Component: • MX-270: "Nikarack MX-270" manufactured by Sanwa Chemical Co., Ltd. • TML-BPA: "TML-BPA" manufactured by Honshu Chemical Co., Ltd.

[0208] [ka]

[0209] (C) Ingredients: • MP-Triazine: "MP-Triazine" manufactured by Sanwa Chemical Co., Ltd.

[0210] [ka]

[0211] (D) Ingredients: • KBM-403: "KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd. • KBM-9659: Manufactured by Shin-Etsu Chemical Co., Ltd. • KBM-1003: "KBM-1003" manufactured by Shin-Etsu Chemical Co., Ltd. • X-12-1290: "X-12-1290" manufactured by Shin-Etsu Chemical Co., Ltd. • KBM-4803: "KBM-4803" manufactured by Shin-Etsu Chemical Co., Ltd. • KBM-1083: "KBM-1083" manufactured by Shin-Etsu Chemical Co., Ltd.

[0212] [ka]

[0213] (D') component: • KBE-1003: "KBE-1003" manufactured by Shin-Etsu Chemical Co., Ltd. • KBM-402: "KBM-402" manufactured by Shin-Etsu Chemical Co., Ltd.

[0214] [ka]

[0215] (E) Ingredients: • MM-101SM: Urethane microparticles "MM-101SM" manufactured by Negami Kogyo Co., Ltd. Average particle size: 0.07~0.1μm.

[0216] [Manufacturing of photosensitive film] As a support, a polyethylene terephthalate film (Toray Industries, Ltd.'s "Lumirror T60", 38 μm thick) with a release treatment applied to its surface was prepared. The photosensitive resin compositions prepared in each example and comparative example were uniformly applied to this support using a die coater so that the thickness of the photosensitive resin composition layer after drying was 20 μm, and the film was dried at 80°C to 110°C for 6 minutes to obtain a photosensitive film. This photosensitive film comprised a support and a photosensitive resin composition layer formed on this support.

[0217] [Evaluation of limiting resolution] A copper-clad laminate was prepared by copper plating a silicon wafer to form a copper layer with a thickness of 5 μm, and then roughening it with a 1% hydrochloric acid aqueous solution for 60 seconds. A photosensitive film was placed on this copper-clad laminate so that the photosensitive resin composition layer was in contact with the surface of the copper layer, and the laminate was laminated using a vacuum laminator (Nikko Materials Co., Ltd., VP160). The lamination conditions were a vacuum time of 30 seconds, a compression temperature of 80°C, a compression pressure of 0.7 MPa, and a pressing time of 30 seconds. After standing at room temperature for 10 minutes, the support was peeled off to obtain an intermediate laminate comprising a copper-clad laminate and a photosensitive resin composition layer.

[0218] This intermediate laminate was subjected to a heat treatment at 100°C for 3 minutes. Subsequently, the photosensitive resin composition layer of the intermediate laminate was exposed to ultraviolet light (wavelength 365 nm, intensity 40 mW / cm²) through a quartz glass mask. 2 Exposure was performed using ). The exposure dose was 50 mJ / cm². 2 From 1000 mJ / cm 2 An optimal value was set within the specified range. Here, the optimal value represents the value that minimizes the critical resolution. Furthermore, as the quartz glass mask, one with multiple mask patterns of different dimensions was used so that multiple circular holes (via holes) with different design aperture diameters could be drawn. After standing at room temperature for 5 minutes, a heat treatment was performed at 100°C for 3 minutes. A 2.38% by mass aqueous solution of tetramethylammonium hydroxide at 23°C was sprayed onto the entire surface of the photosensitive resin composition layer of the intermediate laminate at a spray pressure of 0.1 MPa for 1 minute as the developer, and spray development was performed. After spray development, 1 J / cm 2 The photosensitive resin composition layer was cured by ultraviolet irradiation and then heat treatment at 190°C for 60 minutes. Through these operations, an insulating layer was formed on the copper-clad laminate by the cured photosensitive resin composition.

[0219] The diameter of the bottom of the via holes formed in the insulating layer was observed and measured using a scanning electron microscope (SEM) at a magnification of 1000x. If the diameter of the bottom of the via hole was within the range of 60% to 120% of the design value of the via hole, it was determined that the via hole had been properly formed. Among the properly formed via holes, the one with the smallest design value was selected, and the design value of that selected via hole was obtained as the critical resolution.

[0220] [Evaluation of GaAs adhesion] A photosensitive film was placed on a 6-inch gallium arsenide wafer as a GaAs substrate, with the photosensitive resin composition layer in contact with the gallium arsenide wafer. Lamination was performed using a vacuum laminator (Nikko Materials, VP160) to obtain a laminate comprising the gallium arsenide wafer, the photosensitive resin composition layer, and a support in that order. The lamination conditions were: vacuuming time 30 seconds, compression temperature 80°C, compression pressure 0.7 MPa, and pressurization time 30 seconds. The laminate was left to stand at room temperature for 30 minutes or more, and the entire surface of the photosensitive resin composition layer was exposed to ultraviolet light through the support. The exposure amount at this time was set to the optimal value described above. After leaving the laminate to stand at room temperature for 5 minutes, the support was peeled off. Next, a heat treatment was performed at 100°C for 10 minutes. A 2.38 mass% aqueous solution of tetramethylammonium hydroxide at 23°C was sprayed onto the entire surface of the photosensitive resin composition layer at a spray pressure of 0.1 MPa for 1 minute as a developer, and spray development was performed. After spray development, 1 J / cm 2 The photosensitive resin composition layer was cured by ultraviolet irradiation and then heat treatment at 190°C for 60 minutes. Through these operations, a sample substrate was obtained comprising a gallium arsenide wafer and an insulating layer formed from the cured photosensitive resin composition.

[0221] A cross-cut tape peel test was performed on the insulating layer of the obtained sample substrate in accordance with JIS K5600-5-6:1999 (ISO2409:1992). The adhesion to the gallium arsenide wafer was evaluated according to the following evaluation criteria. "A": Corresponds to classification 0 in Table 1 of JIS K5600-5-6:1999 8.3. "B": Corresponds to classification 1 in Table 1 of JIS K5600-5-6:1999 8.3. "C": Corresponds to classification 2 in Table 1 of JIS K5600-5-6:1999 8.3. "D": Corresponds to classification 3 in Table 1 of JIS K5600-5-6:1999 8.3. "E": Corresponds to classification 4 or classification 5 in Table 1 of JIS K5600-5-6:1999 8.3.

[0222] [Measurement of Cu adhesion] Rolled copper foil (JX Nippon Oil & Metals Corporation, "BHY-22B-T", 18 μm thick) was prepared by washing and drying with 10% sulfuric acid. A photosensitive film was placed on the glossy surface of the rolled copper foil so that the photosensitive resin composition layer was in contact with the surface of the copper layer. Lamination was performed using a vacuum laminator (Nikko Materials Co., Ltd., VP160) to obtain a laminate comprising the rolled copper foil, the photosensitive resin composition layer, and the support in that order. The lamination conditions were a vacuum time of 30 seconds, a compression temperature of 80°C, a compression pressure of 0.7 MPa, and a pressing time of 30 seconds. The laminate was left to stand at room temperature for 30 minutes or more, and the entire surface of the photosensitive resin composition layer was exposed to ultraviolet light through the support. The exposure amount at this time was set to the optimal value mentioned above. After leaving the laminate to stand at room temperature for 5 minutes, the support was peeled off. Next, a heat treatment was performed at 100°C for 10 minutes. A 2.38% by mass aqueous solution of tetramethylammonium hydroxide at 23°C was sprayed onto the entire surface of the photosensitive resin composition layer at a spray pressure of 0.1 MPa for 1 minute as the developer, and spray development was performed. After spray development, the concentration was 1 J / cm². 2 The photosensitive resin composition layer was cured by irradiating it with ultraviolet light and then heating it at 190°C for 60 minutes. Through these operations, a sample substrate was obtained comprising rolled copper foil and an insulating layer formed from the cured product of the photosensitive resin composition.

[0223] The insulating layer side of the obtained sample substrate was bonded to the glass epoxy substrate, and the peel strength of the copper foil was measured using a tensile testing machine (TSE Corporation, "AC-50C-SL") conforming to the Japanese Industrial Standard (JIS C6481). Specifically, a cut was made in the rolled copper foil of the sample substrate, surrounding a section 10 mm wide and 100 mm long. One end of this section was peeled off and grasped with the grip of the tensile testing machine, and the load when 35 mm was peeled off vertically at a speed of 50 mm / min was measured as the peel strength. Based on the measured peel strength, the adhesion to the copper foil was evaluated according to the following criteria. "○": Peel strength of 0.4 kgf or more. "×": Peel strength is less than 0.4 kgf.

[0224] [result] The composition and evaluation results of the photosensitive resin compositions of the above-described examples and comparative examples are shown in the table below. In the table below, the values ​​in the "Reagent" column represent parts by mass. The meanings of the abbreviations in the table below are as follows. (E) Component concentration: The ratio of component (E) to 100% by mass of the non-volatile components of the photosensitive resin composition. Si ratio: The mass percentage of Si atoms contained in the silane coupling agent. Type of alkoxy group: The type of alkoxy group contained in the alkoxysilyl group of the silane coupling agent. In the "Type of alkoxy group" column, "M" indicates a methoxy group. In the "Type of alkoxy group" column, it says "E::Ethoxy group." GaAs adhesion: Adhesion to GaAs substrates. Cu adhesion: Adhesion to copper foil.

[0225] [Table 1]

[0226] [Table 2]

[0227] Table 3

Claims

1. A photosensitive resin composition for forming an insulating layer on a GaAs substrate, (A) Alkali-soluble resin having hydroxyl groups, (B) Melamine resin containing one or more alkoxymethyl groups, (C) Photoacid generator, and (D) Silane coupling agent containing a trimethoxysilyl group, Includes, (A) Component comprises a compound having the structure represented by the following formula (A-1), The amount of the compound having the structure represented by the following formula (A-1) is 10% by mass or more and 50% by mass or less, when the nonvolatile components of the photosensitive resin composition are considered to be 100% by mass. A photosensitive resin composition comprising component (D) 1,2-bis(trimethoxysilyl)ethane. 【Chemistry 1】 (In formula (A-1), R ３ This represents a divalent group represented by the following formula (a), a divalent group represented by the following formula (b), a divalent group represented by the following formula (c), or a divalent group consisting of a combination thereof. X ３ and X ４ Each of these independently represents an optionally substituted alkyl group, an optionally substituted aryl group, a halogen atom, or an optionally substituted monovalent heterocyclic group. n3 and n4 each independently represent integers between 0 and 4. 【Chemistry 2】 In formula (a), R １１ and R １２ Each of these independently represents a hydrogen atom, an optionally substituted alkyl group, an aryl group, an optionally substituted monovalent heterocyclic group, an amino group, a carboxyl group, a group consisting of a combination thereof, or a group consisting of a combination thereof with a carbonyl group, and * represents a bond. In formula (b), X １１ Each of these independently represents an alkyl group which may have substituents. p1 represents an integer from 0 to 4. * represents a bond. In formula (c), X １２ and X １３ Each of the following independently represents an optionally substituted alkyl group. p2 and p3 independently represent integers from 0 to 4. * represents a bond.

2. The photosensitive resin composition according to claim 1, wherein component (D) contains 11.5% by mass or more of Si atoms in its molecule.

3. (E) The photosensitive resin composition according to claim 1 or 2, comprising an organic filler.

4. (E) The photosensitive resin composition according to claim 3, wherein the amount of organic filler is 7% by mass or more and 30% by mass or less, when the nonvolatile components of the photosensitive resin composition are taken as 100% by mass.

5. The photosensitive resin composition according to any one of claims 1 to 4, wherein component (A) contains a compound having a structure represented by the following formula (A-2). 【Transformation 3】 (In formula (A-2), R １ each independently represents a divalent group represented by the following formula (a), X １ Each of these independently represents an optionally substituted alkyl group, an optionally substituted aryl group, a halogen atom, or an optionally substituted monovalent heterocyclic group. n1 represents an integer from 0 to 4. m1 represents an integer between 1 and 200. * represents a combination. 【Chemistry 4】 In formula (a), R １１ and R １２ Each of these independently represents a hydrogen atom, an optionally substituted alkyl group, an optionally substituted aryl group, an optionally substituted monovalent heterocyclic group, an amino group, a carboxyl group, a group consisting of a combination thereof, or a group consisting of a combination thereof and a carbonyl group, R １１ and R １２ They may be joined together to form a ring. (* represents a bonding hand.)

6. The photosensitive resin composition according to any one of claims 1 to 5, wherein component (D) has an organic group selected from the group consisting of a monovalent or divalent or more saturated hydrocarbon group and a monovalent or divalent or more aromatic hydrocarbon group.

7. A photosensitive film comprising a support and a photosensitive resin composition layer provided on the support, the photosensitive resin composition comprising the photosensitive resin composition according to any one of claims 1 to 6.

8. A circuit board comprising an insulating layer containing a cured product of the photosensitive resin composition according to any one of claims 1 to 6.

9. The circuit board according to claim 8, comprising a GaAs substrate and the insulating layer formed on the GaAs substrate.

10. A semiconductor device comprising the circuit board described in claim 8 or 9.

11. (I) A step of forming a photosensitive resin composition layer on a GaAs substrate, which contains the photosensitive resin composition according to any one of claims 1 to 6. (II) A step of exposing the photosensitive resin composition layer, (III) A step of developing the photosensitive resin composition layer, A method for manufacturing a circuit board, comprising the elements in this order.

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