WO2023153390A1

WO2023153390A1 - Photosensitive resin sheet, cured film, and multilayer wiring substrate

Info

Publication number: WO2023153390A1
Application number: PCT/JP2023/003951
Authority: WO
Inventors: 濱野翼; 小森悠佑
Original assignee: 東レ株式会社
Priority date: 2022-02-14
Filing date: 2023-02-07
Publication date: 2023-08-17
Also published as: TW202340860A; JPWO2023153390A1

Abstract

The purpose of the present invention is to provide a photosensitive resin sheet in which the cross-sectional shape of a pattern is rectangular, a fine pattern can be formed and a pattern defect part can be identified easily, and through which a metal wiring in an underlayer part cannot be seen. Provided is a photosensitive resin sheet comprising a support film and a photosensitive resin layer, the photosensitive resin sheet being characterized in that the photosensitive resin layer is formed from a photosensitive resin composition, the photosensitive resin composition comprises an alkali-soluble polyimide (A), a photopolymerizable compound (B), a photopolymerization initiator (C) and a coloring material (D), the photosensitive resin layer satisfies the below-mentioned relationship A wherein Tb600 represents a transmittance at 600 nm and TbVL represents a minimum value among transmittances in a wavelength range from 500 to 800 nm. Relationship A: at least one of formulae 1 and 2 is satisfied. Formula 1: 0.10% ≤ Tb600 ≤ 40% Formula 2: 0.10% ≤ TbVL ≤ 40%

Description

Photosensitive resin sheet, cured film, and multilayer wiring board

The present invention relates to a photosensitive resin sheet, a cured film, and a multilayer wiring board.

Due to its excellent electrical properties, mechanical properties, and heat resistance, polyimide is useful as a surface protective film for semiconductor elements, an interlayer insulating film, and a wiring protective insulating film for circuit boards. In particular, a photosensitive polyimide material to which photosensitivity has been imparted can be microfabricated by photolithography technology, and wiring density can be increased. Photosensitive polyimide materials are generally liquid or sheet-like materials, and in particular, sheet-like materials are easier to form thick films than liquid materials, and the number of processes can be reduced, so production efficiency is high. It has advantages such as

So far, as a photosensitive polyimide resin composition, a photosensitive resin composition containing a polyimide or a polyimide precursor having a carbon-carbon unsaturated double bond and a compound that generates radicals by actinic ray radiation has been proposed. (Patent Document 1). However, in order to ring-close the polyimide precursor, heat treatment at a high temperature exceeding 300 ° C. is required, so the metal material that is the wiring material is easily oxidized, and therefore the electrical properties and reliability of the electronic component are improved. had a problem.

Therefore, as a photosensitive resin composition using a ring-closed polyimide, a polyimide having at least one group selected from the group consisting of a carboxyl group, a phenolic hydroxyl group, a sulfonic acid group and a thiol group at the main chain terminal, an unsaturated bond A photosensitive resin composition containing a polymerizable compound, imidazole silane, and a photopolymerization initiator has been proposed (Patent Document 2). Such techniques enable photopatterning of polyimide resin compositions without the need for heat treatment at high temperatures, and there is an increasing demand for higher wiring densities.

　In the case of a multilayer wiring structure, a thick film processing is required for the protective insulating film. In general, closed-ring polyimides have a large absorption of actinic rays, so that it is difficult to sufficiently photo-cure deep portions of the thick film of the photosensitive resin composition in the exposure step of photopatterning. In this case, the pattern formed on the photosensitive resin composition tends to have a reverse tapered cross-sectional shape (a shape in which the actinic ray incident side is the front surface and tapers toward the back surface), making it difficult to obtain a rectangular pattern. There is a problem. Therefore, when an inversely tapered pattern is used for a wiring insulating film of a semiconductor element, etc., it is necessary to form a rectangular pattern because the embedding of the metal used as the wiring becomes insufficient, and conduction failure tends to occur. Therefore, various photosensitive resin compositions have been invented in order to increase the light transmittance (for example, Patent Document 3).

JP-A-2016-8992 JP 2011-17897 A WO2016/158389

In general, the cross-sectional shape of the pattern is rectangular, and a thick photosensitive resin sheet that enables the formation of fine patterns is a material with enhanced light transmission. As a result, the visibility of the pattern portion after pattern formation is poor, making it difficult to determine the missing portion of the pattern. In addition, in the inspection of multi-layered wiring boards, since the metal wiring pattern in the lower layer is transparent, false detection occurs in the inspection of the pattern of the protective insulating film. be a factor.

In view of such circumstances, the present invention provides a photosensitive resin sheet which has a rectangular cross-sectional shape of the pattern, which enables the formation of a fine pattern, makes it easy to determine where the pattern is defective, and prevents the metal wiring in the lower layer from being seen through. intended to provide

The present invention for solving the above problems consists of the following configurations.
[1] A photosensitive resin sheet having a support film and a photosensitive resin layer,
The photosensitive resin layer is a layer formed from a photosensitive resin composition,
The photosensitive resin composition is a resin composition containing an alkali-soluble polyimide (A), a photopolymerizable compound (B), a photopolymerization initiator (C), and a coloring agent (D),
A photosensitive resin sheet characterized in that the photosensitive resin layer satisfies the following relationship A when the transmittance at 600 nm is Tb600 and the minimum transmittance at 500 to 800 nm is TbVL.
Relationship A: Formula 1 that satisfies at least one of formulas 1 and 2: 0.10% ≤ Tb600 ≤ 40%
Formula 2: 0.10% ≤ TbVL ≤ 40%
[2] The photosensitive resin layer according to [1], wherein the following relationship B is satisfied when the transmittance at 365 nm is Tb365, the transmittance at 405 nm is Tb405, and the transmittance at 436 nm is Tb436. Photosensitive resin sheet.
Relationship B: Formula 3 that satisfies at least one of formulas 3 to 5: 3.0% ≤ Tb365 ≤ 70%
Formula 4: 3.0% ≤ Tb405 ≤ 70%
Formula 5: 3.0% ≤ Tb436 ≤ 70%
[3] The photosensitive resin sheet according to any one of [1] and [2], wherein the alkali-soluble polyimide (A) is a ring-closed polyimide.
[4] The photosensitive resin sheet according to any one of [1] to [3], further comprising a protective film, wherein the support film, the photosensitive resin layer, and the protective film are directly laminated in this order.
[5] The photosensitive resin sheet according to any one of [1] to [4], wherein the photosensitive resin layer has a transmittance Tb450 at 450 nm that satisfies the following relationship.

40%≤Tb450≤95%
[6] The content of the coloring material (D) is 0.1 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the alkali-soluble polyimide (A) [1] to [ 5]. The photosensitive resin sheet according to any one of the above items.
[7] The photosensitive resin sheet according to any one of [1] to [6], wherein the coloring agent (D) contains an anthraquinone compound.
[8] The photosensitive resin sheet according to any one of [1] to [7], wherein the photosensitive resin composition contains inorganic particles.
[9] The photosensitive resin sheet of [8], wherein the inorganic particles have an average particle diameter D50 of 30 to 150 nm.
[10] The photosensitive resin sheet according to any one of [1] to [9], wherein the photosensitive resin layer has a thickness of 15 to 40 μm.
[11] The photosensitive resin sheet according to any one of [1] to [10], wherein the photosensitive resin composition has a melt viscosity of 1500 to 50000 Pa·s at 80°C.
[12] A cured film formed by heating and curing the photosensitive resin layer of the photosensitive resin sheet according to any one of [1] to [11].
[13] In [12], the following formula 6 and relationship C are satisfied when the transmittance Tc450 at 450 nm, the transmittance Tc600 at 600 nm, and the minimum transmittance TcVL at 500 to 800 nm are satisfied. Cured film as described.

Formula 6: 20% ≤ Tc450 ≤ 90%
Relationship C: satisfying at least one of formulas 7 and 8 Formula 7: 0.10% ≤ Tc600 ≤ 50%
Formula 8: 0.10% ≤ TcVL ≤ 50%
[14] The cured film of [12] or [13], which has a linear expansion coefficient (α) of 30×10 ⁻⁶ /K or more and 55×10 ⁻⁶ /K or less.
[15] The cured film according to any one of [12] to [14], which has a glass transition temperature of 250°C to 350°C.
[16] A multilayer wiring board having the cured film according to [12].

According to the present invention, it is possible to obtain a photosensitive resin sheet whose pattern has a rectangular cross-sectional shape, which enables formation of a fine pattern, and which facilitates determination of pattern defect locations. The cured film obtained from the photosensitive resin sheet of the present invention is excellent in electrical properties, mechanical properties, and heat resistance, and is therefore useful as a surface protective film for semiconductor elements, an interlayer insulating film, and a wiring protective insulating film for circuit boards. is.

It is a cross-sectional schematic diagram which showed one aspect|mode by which the recessed part was formed using the photosensitive resin sheet of this invention. FIG. 2 is a schematic cross-sectional view showing one mode in which a defective portion is included in a pattern in which recesses are formed using the photosensitive resin sheet of the present invention. It is the cross-sectional schematic diagram which showed the one aspect|mode in which the peeling location of the pattern which formed the recessed part using the photosensitive resin sheet of this invention was generated on the metal wiring. It is a cross-sectional schematic diagram showing the measurement positions of the top width and the bottom width of the cross section of the pattern formed using the photosensitive resin sheet of the present invention.

The present invention is a photosensitive resin sheet having a support film and a photosensitive resin layer, wherein the photosensitive resin layer is a layer formed from a photosensitive resin composition, and the photosensitive resin composition is an alkali-soluble polyimide (A), a photopolymerizable compound (B), a photopolymerization initiator (C), and a resin composition containing a coloring agent (D), wherein the photosensitive resin layer is at 600 nm A photosensitive resin sheet characterized by satisfying the following relation A when the transmittance Tb is 600 and the minimum value TbVL of the transmittance at 500 to 800 nm.
Relationship A: satisfying at least one of formulas 1 and 2 Formula 1: 0.10 ≤ Tb600 ≤ 40%
Formula 2: 0.10% ≤ TbVL ≤ 40%
Details of this are given below.

[Alkali-soluble polyimide (A)]
The photosensitive resin composition forming the photosensitive resin layer in the photosensitive resin sheet of the present invention contains an alkali-soluble polyimide (A). Containing the alkali-soluble polyimide (A) facilitates formation of a thick photosensitive resin sheet, and facilitates adjustment of the film thickness according to the application.

The main skeleton of the alkali-soluble polyimide (A) is not particularly limited, but (meth)acrylic polymer, epoxy polymer, polyurethane, polybenzoxazine, polybenzoxazole precursor, polybenzoxazole, polyimide precursor, polyimide, etc. can be used. can. Among them, from the viewpoint of heat resistance, the alkali-soluble polyimide (A) is at least one resin selected from the group consisting of polyimide, polybenzoxazole, precursors thereof, and copolymers thereof, that is, , polybenzoxazole precursors, polybenzoxazoles, polyimide precursors, ring-closed polyimides, and copolymers thereof. The alkali-soluble polyimide (A) is more preferably a polyimide precursor or a closed-ring polyimide, which suppresses corrosion of metal wiring, improves the electrical reliability of the wiring board, and can lower the heat treatment temperature after patterning. From the point of view, it is particularly preferable to use a closed-ring polyimide.

The alkali-soluble polyimide (A) preferably dissolves in a developer and has at least alkali solubility. The term "alkali-soluble" as used herein means that the solubility in a 2.38% by weight tetramethylammonium hydroxide (TMAH) aqueous solution is 0.1 g/100 mL or more. By imparting alkali-solubility to the alkali-soluble polyimide (A) in the photosensitive resin sheet, the dissolution of the photosensitive resin sheet in an alkali developer is promoted, and a favorable pattern shape can be obtained. The functional group that imparts alkali solubility to the alkali-soluble polyimide (A), that is, the alkali-soluble group includes a phenolic hydroxyl group, a thiol group, a carboxyl group, a sulfonic acid group, etc. As the alkali-soluble group, a phenolic hydroxyl group , carboxyl groups or both.

Suitable examples of polyimides for alkali-soluble polyimides (A) are shown below.

As the alkali-soluble polyimide (A), it is preferable to contain one or more polyimides having a structural unit represented by the following general formula (1), and one or more polyimides represented by the following general formula (2) or (3) It is more preferable to contain polyimide.

In general formulas (1) to (3), X represents a monovalent organic group having at least one of a carboxyl group, a phenolic hydroxyl group, a sulfonic acid group and a thiol group. Y represents a divalent organic group having at least one of a carboxyl group, a phenolic hydroxyl group, a sulfonic acid group and a thiol group. X and Y preferably have a phenolic hydroxyl group or a thiol group, and particularly preferably have a phenolic hydroxyl group.

R ¹ represents a 4- to 22-valent organic group, and R ² represents a 2- to 20-valent organic group. ^R3 and ^R4 each independently represent a carboxyl group, a phenolic hydroxyl group, a sulfonic acid group or a thiol group. R ³ and R ⁴ are preferably phenolic hydroxyl groups or carboxyl groups, particularly preferably phenolic hydroxyl groups.

Also, α and β each independently represent an integer ranging from 0 to 10. Among such α and β, it is preferable that α+β is 1 or more. n represents the number of repeating structural units of the polymer. The range of n is 3-200. If n is 3 or more, it is possible to further improve the thick film workability of the photosensitive resin sheet. From the viewpoint of improving the thick film workability, n is preferably 5 or more. On the other hand, when n is 200 or less, the solubility of the alkali-soluble polyimide (A) in an alkali developer can be improved. From the viewpoint of improving the solubility, n is preferably 100 or less.

In the above general formulas (1) to (3), R ¹ is a 4- to 22-valent organic group having a structure derived from tetracarboxylic dianhydride. Among them, R ¹ is preferably an organic group having 5 to 45 carbon atoms containing an aromatic group or a cycloaliphatic group.

Examples of tetracarboxylic dianhydrides include aromatic tetracarboxylic dianhydrides and aliphatic tetracarboxylic dianhydrides. Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 2,3,3′,4′-biphenyltetracarboxylic dianhydride, Carboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3 '-benzophenonetetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 1, 1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride , bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, 1,2, 5,6-naphthalenetetracarboxylic dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluoric dianhydride, 9,9-bis{4-(3,4-dicarboxyphenoxy)phenyl } Fluoric dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 2,3,5,6-pyridinetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic Acid dianhydride, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, 2,2',3,3'-diphenylsulfonic acid tetracarboxylic dianhydride, ethylenetetracarboxylic acid dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, 4-(2,5-dioxotetrahydrofuran)-3-yl)-1,2,3,4-tetrahydronaphthalene-1 ,2-dicarboxylic anhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)-4methyl-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dianhydride, 4- (2,5-dioxotetrahydrofuran-3-yl)-7methyl-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dianhydride, norbornane-2-spiro-2′-cyclopentanone -5′-spiro-2″-norbornane-5,5″,6,6″-tetracarboxylic dianhydride, norbornane-2-spiro-2′-cyclohexanone-6′-spiro-2″ -Norbornane-5,5'',6,6''-tetracarboxylic dianhydride and the like.

Examples of aliphatic tetracarboxylic dianhydrides include butanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, and 2,3,5,6-cyclohexanetetracarboxylic acid. acid dianhydride, Epiclon (registered trademark) B-4400 (Dainippon Ink & Chemicals, Inc.), Rikacid TDA-100 and BT-100 (Shin Nippon Rika Co., Ltd.), and the like.

In addition, examples of tetracarboxylic dianhydrides include acid dianhydrides having the structures shown below. In the present embodiment, as the tetracarboxylic dianhydride, two types of the aromatic tetracarboxylic dianhydride described above, the aliphatic tetracarboxylic dianhydride, and the acid dianhydride having the structure shown below The above may be used.

wherein ^R5 is an oxygen atom, ^a group selected from C( _CF3 ) ₂ ^, C( _CH3 ) ₂ and _SO2 ; and represents a group selected from a thiol group.

In the above general formulas (1) to (3), R ² is a divalent to dodecavalent organic group having a diamine-derived structure. Among them, an organic group having 5 to 40 carbon atoms containing an aromatic group or a cycloaliphatic group is preferred.

Diamines include, for example, hydroxyl group-containing diamines, carboxyl group-containing diamines, thiol group-containing diamines, aromatic diamines, compounds in which at least some of the hydrogen atoms of these aromatic rings are substituted with alkyl groups or halogen atoms, fatty group diamines and the like.

Examples of hydroxyl group-containing diamines include bis-(3-amino-4-hydroxyphenyl)hexafluoropropane, bis(3-amino-4-hydroxyphenyl)sulfone, bis(3-amino-4-hydroxyphenyl)propane. , bis(3-amino-4-hydroxyphenyl)methylene, bis(3-amino-4-hydroxyphenyl)ether, bis(3-amino-4-hydroxy)biphenyl, bis(3-amino-4-hydroxyphenyl) Fluorene, 2,2'-ditrifluoromethyl-5,5'-4,4'-diaminobiphenyl, bis(3-amino-4-hydroxyphenyl)fluorene, 2,2'-bis(trifluoromethyl)-5 -5'-dihydroxybenzidine and the like. Carboxyl group-containing diamines include, for example, 2,2-bis[3-amino-4-carboxyphenyl]propane, 2,2-bis[4-amino-3-carboxyphenyl]propane, 2,2-bis[3 -amino-4-carboxyphenyl]hexafluoropropane, 4,4'-diamino-2,2',5,5'-tetracarboxydiphenylmethane, 3,3'-diamino-4,4'-dicarboxydiphenyl ether, 4 ,4'-diamino-3,3'-dicarboxydiphenyl ether, 4,4'-diamino-2,2'-dicarboxydiphenyl ether, 4,4'-diamino-2,2',5,5'-tetracarboxy Diphenyl ether, 3,3'-diamino-4,4'-dicarboxydiphenylsulfone, 4,4'-diamino-3,3'-dicarboxydiphenylsulfone, 4,4'-diamino-2,2'-dicarboxy Diphenylsulfone, 4,4'-diamino-2,2',5,5'-tetracarboxydiphenylsulfone, 2,2-bis[4-(4-amino-3-carboxyphenoxy)phenyl]propane, 2,2 -bis[4-(4-amino-3-carboxyphenoxy)phenyl]sulfone and the like. Thiol group-containing diamines include, for example, dimercaptophenylenediamine.

Examples of aromatic diamines include 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4, 4'-diaminodiphenylmethane, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide , 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, benzidine, m-phenylenediamine, p-phenylene Diamine, 1,5-naphthalenediamine, 2,6-naphthalenediamine, bis(4-aminophenoxyphenyl)sulfone, bis(3-aminophenoxyphenyl)sulfone, bis(4-aminophenoxy)biphenyl, bis{4-( 4-aminophenoxy)phenyl}ether, 1,4-bis(4-aminophenoxy)benzene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-diethyl-4,4'-diamino biphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-diethyl-4,4'-diaminobiphenyl, 2,2',3,3'-tetramethyl-4,4'- Diaminobiphenyl, 3,3′,4,4′-tetramethyl-4,4′-diaminobiphenyl, 2,2′-di(trifluoromethyl)-4,4′-diaminobiphenyl, 9,9-bis( 4-aminophenyl)fluorene and the like. Examples of aliphatic diamines include cyclohexyldiamine and methylenebiscyclohexylamine.

In addition, diamines include, for example, diamines having the structures shown below. In this embodiment, as the diamine, at least part of the hydroxyl group-containing diamine, the carboxyl group-containing diamine, the thiol group-containing diamine, the aromatic diamine, and the hydrogen atoms of these aromatic rings are substituted with an alkyl group or a halogen atom. , aliphatic diamines, and diamines having the structures shown below may be used.

Here, R ⁵ is an oxygen atom, a group selected from C(CF ₃ ) ₂ , C(CH ₃ ) ₂ and SO ₂ , R ⁶ to R ⁹ are each independently a carboxyl group, hydroxyl group, sulfonic acid group and represents a group selected from thiol groups.

Among the diamines mentioned above, bis-(3-amino-4-hydroxyphenyl)hexafluoropropane, bis(3-amino-4-hydroxyphenyl)sulfone, bis(3-amino-4-hydroxyphenyl)propane, bis( 3-amino-4-hydroxyphenyl)methylene, bis(3-amino-4-hydroxyphenyl)ether, bis(3-amino-4-hydroxy)biphenyl, bis(3-amino-4-hydroxyphenyl)fluorene, 2 , 2-bis[3-amino-4-carboxyphenyl]propane, 2,2-bis[4-amino-3-carboxyphenyl]propane, 2,2-bis[3-amino-4-carboxyphenyl]hexafluoro Propane, 4,4'-diamino-2,2',5,5'-tetracarboxydiphenylmethane, 3,3'-diamino-4,4'-dicarboxydiphenyl ether, 4,4'-diamino-3,3' -dicarboxydiphenyl ether, 4,4'-diamino-2,2'-dicarboxydiphenyl ether, 4,4'-diamino-2,2',5,5'-tetracarboxydiphenyl ether, 3,3'-diamino-4 ,4'-dicarboxydiphenylsulfone, 4,4'-diamino-3,3'-dicarboxydiphenylsulfone, 4,4'-diamino-2,2'-dicarboxydiphenylsulfone, 4,4'-diamino- 2,2',5,5'-tetracarboxydiphenylsulfone, 2,2-bis[4-(4-amino-3-carboxyphenoxy)phenyl]propane, 2,2-bis[4-(4-amino- 3-carboxyphenoxy)phenyl]sulfone, 3,3′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3,3′-diaminodiphenylmethane, 3,4′-diaminodiphenylmethane, 4 , 4'-diaminodiphenylmethane, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl Sulfides, m-phenylenediamine, p-phenylenediamine, 1,4-bis(4-aminophenoxy)benzene, 9,9-bis(4-aminophenyl)fluorene and diamines having the structures shown below are preferred.

In general formulas (1) to (3) above, R ³ and R ⁴ each independently represent a carboxyl group, a phenolic hydroxyl group, a sulfonic acid group or a thiol group, as described above. By adjusting the amount of these alkali-soluble groups of ^R3 and ^R4 , the dissolution rate of the alkali-soluble polyimide (A) in an alkaline aqueous solution changes, so that a photosensitive resin sheet having a desired dissolution rate can be obtained. can.

Furthermore, in order to improve the adhesiveness to the substrate, a diamine having a siloxane structure at ^R2 may be copolymerized within a range that does not lower the heat resistance. Specifically, as the diamine component, bis(3-aminopropyl)tetramethyldisiloxane, bis(p-amino-phenyl)octamethylpentasiloxane, etc. may be copolymerized in an amount of 1 to 10 mol %.

In general formula (2), X is derived from a primary monoamine that is a terminal blocking agent. Primary monoamines used as terminal blockers include 5-amino-8-hydroxyquinoline, 1-hydroxy-7-aminonaphthalene, 1-hydroxy-6-aminonaphthalene, 1-hydroxy-5-aminonaphthalene, 1 -hydroxy-4-aminonaphthalene, 2-hydroxy-7-aminonaphthalene, 2-hydroxy-6-aminonaphthalene, 2-hydroxy-5-aminonaphthalene, 1-carboxy-7-aminonaphthalene, 1-carboxy-6- aminonaphthalene, 1-carboxy-5-aminonaphthalene, 2-carboxy-7-aminonaphthalene, 2-carboxy-6-aminonaphthalene, 2-carboxy-5-aminonaphthalene, 2-aminobenzoic acid, 3-aminobenzoic acid , 4-aminobenzoic acid, 4-aminosalicylic acid, 5-aminosalicylic acid, 6-aminosalicylic acid, 2-aminobenzenesulfonic acid, 3-aminobenzenesulfonic acid, 4-aminobenzenesulfonic acid, 3-amino-4,6 -dihydroxypyrimidine, 2-aminophenol, 3-aminophenol, 4-aminophenol, 2-aminothiophenol, 3-aminothiophenol, 4-aminothiophenol and the like are preferred. These are used alone or in combination of two or more.

Also, in general formula (3), Y is derived from a dicarboxylic anhydride that is a terminal blocking agent. As the acid anhydride used as the terminal blocking agent, 4-carboxyphthalic anhydride, 3-hydroxyphthalic anhydride, cis-aconitic anhydride and the like are preferable. These are used alone or in combination of two or more.

The alkali-soluble polyimide (A) used in the present invention may consist of only the structures represented by the general formulas (1) to (3), or may be a mixture with other structures having alkali solubility. It can be. At that time, it is preferable that the alkali-soluble polyimide (A) having the structure represented by the general formulas (1) to (3) is contained in an amount of 50% by weight or more based on the total weight of the alkali-soluble polyimide. Furthermore, it is preferably 60% by weight or more. When the content is 50% by weight or more, shrinkage during thermosetting can be suppressed, which is suitable for producing a thick film. The type and amount of the alkali-soluble resin to be mixed is preferably selected within a range that does not impair the heat resistance of the polyimide finally obtained by heat treatment.

The alkali-soluble polyimide (A) replaces part of the diamine with a terminal blocking agent monoamine, or replaces the tetracarboxylic dianhydride with a terminal blocking agent dicarboxylic anhydride, known method can be used to synthesize. For example, a method of reacting a tetracarboxylic dianhydride, a diamine compound and a monoamine at a low temperature, a method of reacting a tetracarboxylic dianhydride, a dicarboxylic anhydride and a diamine compound at a low temperature, and a method of reacting a tetracarboxylic dianhydride with a diamine compound. A polyimide precursor is obtained by using a method such as a method of obtaining a diester with an alcohol, and then reacting a diamine, a monoamine and a condensing agent. Thereafter, the obtained polyimide precursor can be completely imidized using a known imidization reaction method to synthesize a closed-ring polyimide.

It is preferable that the closed-ring polyimide used in the present invention is polymerized by the above method, then put into a large amount of water or a mixture of methanol and water, etc., precipitated, filtered, dried, and isolated. The drying temperature is preferably 40-100°C, more preferably 50-80°C. By this method, unreacted monomer and oligomer components are removed, and the film properties of the thermoset film can be improved.

Also, the imidization rate of the alkali-soluble polyimide (A) can be easily determined by, for example, the following method. Here, the imidization rate means what mol % of the polyimide precursor is converted to polyimide when synthesizing a closed-ring polyimide via the polyimide precursor as described above. First, the infrared absorption spectrum of the polymer is measured to confirm the presence of absorption peaks (near 1780 cm ⁻¹ and 1377 cm ⁻¹ ) of the imide structure due to polyimide. Next, after heat-treating the polymer at 350° C. for 1 hour, the infrared absorption spectrum is measured again, and the peak intensity near 1377 cm ⁻¹ before and after the heat treatment is compared. Assuming that the imidization rate of the polymer after the heat treatment is 100%, the imidization rate of the polymer before the heat treatment is obtained. In the present invention, a polyimide having an imidization rate of 50% or more is defined as a closed-ring polyimide. The alkali-soluble polyimide (A) is preferably a closed-ring polyimide, and in particular the imidization rate of the polymer is preferably 70% or more, more preferably 80% or more, and preferably 90% or more. More preferred. In the heating step (curing), a cured film can be obtained by heat treatment under low temperature conditions, so that the effect of reducing stress can be obtained, and cracks and breakage of the substrate can be suppressed. Moreover, since there are few carboxylic acid groups derived from the polyimide precursor, corrosion of metal wiring can be suppressed.

The terminal blocking agent introduced into the alkali-soluble polyimide (A) can be detected by the following method. For example, a polyimide into which a terminal blocking agent has been introduced is dissolved in an acidic solution to decompose into an amine component and a carboxylic acid anhydride component, which are constituent units of the polyimide, and this is analyzed by gas chromatography (GC) or NMR. Measure. Apart from this, it can also be detected by directly measuring polyimide into which a terminal blocker has been introduced using a pyrolysis gas chromatograph (PGC), an infrared spectrum, and a ¹³ CNMR spectrum.

The content of the alkali-soluble polyimide (A) is preferably 20% by mass or more, more preferably 30% by mass or more, in 100% by mass of the solid content of the photosensitive resin layer, excluding the inorganic particles described later. It is preferably 40% by mass or more, and more preferably 40% by mass or more. As the content of the alkali-soluble polyimide (A) increases, the elastic modulus, pressure resistance, and heat resistance of the cured film can be improved. On the other hand, the content of the alkali-soluble polyimide (A) is preferably 80% by mass or less in 100% by mass of the solid content of the photosensitive resin layer, excluding the inorganic particles described later, and is 70% by mass or less. is more preferably 60% by mass or less. The lower the content of the alkali-soluble polyimide (A), the better the lamination properties of the photosensitive resin sheet.

[Photopolymerizable compound (B)]
The photosensitive resin composition forming the photosensitive resin layer in the photosensitive resin sheet of the present invention contains a photopolymerizable compound (B). The photopolymerizable compound (B) means a compound having a functional group exhibiting radical polymerizability or cationic polymerizability in its molecule. Examples of functional groups exhibiting radical polymerizability include vinyl groups, allyl groups, acryloyl groups, methacryloyl groups, propargyl groups, and the like. Among these, compounds having an acryloyl group or a methacryloyl group are preferable from the standpoint of polymerizability. A compound having an acryloyl group or a methacryloyl group is hereinafter referred to as a (meth)acrylic compound. Examples of compounds having functional groups exhibiting cationic polymerizability include cyclic ether compounds (epoxy compounds, oxetane compounds, etc.), ethylenically unsaturated compounds (vinyl ethers, styrenes, etc.), bicycloorthoesters, spiroorthocarbonates and spiroortho Ester etc. are mentioned.

The equivalent weight of functional groups exhibiting radical polymerizability or cationic polymerizability (hereinafter referred to as photopolymerizable functional group equivalent weight) in the photopolymerizable compound (B) is 70 to 200 g/eq on average. The photopolymerizable functional group equivalent of the photopolymerizable compound (B) is preferably 70 g/eq or more on average, more preferably 80 g/eq or more, further preferably 90 g/eq or more, 100 g/eq or more is particularly preferred. The greater the photopolymerizable functional group equivalent, the more the elongation of the cured film can be improved, and the more the occurrence of cracks can be suppressed. On the other hand, the average photopolymerizable functional group equivalent of the photopolymerizable compound (B) is preferably 200 g/eq or less, more preferably 180 g/eq or less, and 160 g/eq or less. More preferably, it is particularly preferably 140 g/eq or less. As the photopolymerizable functional group equivalent is smaller, the heat resistance and elastic modulus of the cured film can be improved, and the reliability of the cured film is increased. Moreover, high-resolution pattern formation becomes possible. It is presumed that this is because the polymerization reaction in the exposed areas progressed more favorably during photocuring, resulting in a greater difference in dissolution contrast in the developer between the exposed areas and the unexposed areas.

The photopolymerizable functional group equivalent is obtained from the following formula.
Photopolymerizable functional group equivalent = (molecular weight/number of radically polymerizable or cationic polymerizable functional groups in the same molecule)
The number of functional groups exhibiting radical polymerizability or cationic polymerizability of the photopolymerizable compound (B) is preferably 2 or more, more preferably 3 or more. As the number of functional groups increases, the heat resistance of the cured film can be improved. In addition, after photocuring, the solubility of the exposed portion in the developer is reduced, so that the pattern can be formed with high resolution. On the other hand, the number of functional groups exhibiting radical polymerizability or cationic polymerizability of the photopolymerizable compound (B) is preferably 16 or less, more preferably 6 or less. The smaller the number of functional groups, the more it is possible to suppress the occurrence of cracks in the cured film.

The photopolymerizable compound (B) is not particularly limited as long as it has a photopolymerizable functional group equivalent weight of 70 to 200 g/eq. Ethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, trimethylolpropane dimethacrylate, trimethylolpropane trimethacrylate, butyl acrylate, butyl methacrylate , isobutyl acrylate, hexyl acrylate, isooctyl acrylate, isobornyl acrylate, isobornyl methacrylate, cyclohexyl methacrylate, glycidyl methacrylate, 4-hydroxybutyl acrylate glycidyl ether, 1,3-butanediol diacrylate, 1,3-butanediol Dimethacrylate, neopentyl glycol diacrylate, 1,4-butanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, 1,9-nonane diol dimethacrylate, 1,10-decanediol dimethacrylate, dimethyloltricyclodecane diacrylate, dimethyloltricyclodecane dimethacrylate, 1,3-adamantane diacrylate, 1,3-adamantane dimethacrylate, 1,3,5 - adamantane triacrylate, 1,3,5-adamantane trimethacrylate, 5-hydroxy-1,3-adamantane diacrylate, 5-hydroxy-1,3-adamantane dimethacrylate, pentacyclopentadecane dimethanol diacrylate, pentacyclopentadecane dimethanol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 1 ,3-diacryloyloxy-2-hydroxypropane, 1,3-dimethacryloyloxy-2-hydroxypropane, 2,2,6,6-tetramethylpiperidinyl methacrylate, 2,2,6,6-tetramethyl piperidinyl acrylate, N-methyl-2,2,6,6-tetramethylpiperidinyl methacrylate, N-methyl-2,2,6,6-tetramethylpiperidinyl acrylate, dioxane glycol diacrylate, ethylene oxide modified Bisphenol A diacrylate, ethylene oxide-modified bisphenol A dimethacrylate, propylene oxide-modified bisphenol A diacrylate, propylene oxide-modified bisphenol A methacrylate, propoxylated ethoxylated bisphenol A dimethacrylate, propoxylated ethoxylated bisphenol A dimethacrylate, ethylene oxide-modified pentaerythritol tetra Methacrylate, propylene oxide-modified pentaerythritol tetraacrylate, ethylene oxide isocyanurate-modified diacrylate, ethylene oxide isocyanurate-modified dimethacrylate, ethylene oxide isocyanurate-modified triacrylate, and ethylene oxide isocyanurate-modified trimethacrylate.

As the epoxy compound suitable as the photopolymerizable compound (B), known compounds can be used, including aromatic epoxy compounds, alicyclic epoxy compounds and aliphatic epoxy compounds.

Examples of aromatic epoxy compounds include glycidyl ethers of monohydric or polyhydric phenols (phenol, bisphenol A, phenol novolak, and alkylene oxide adducts thereof) having at least one aromatic ring.

Examples of alicyclic epoxy compounds include compounds obtained by epoxidizing a compound having at least one cyclohexene or cyclopentene ring with an oxidizing agent (3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, etc. ).

Aliphatic epoxy compounds include aliphatic polyhydric alcohols or polyglycidyl ethers of alkylene oxide adducts thereof (1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, etc.), aliphatic polybasic acids polyglycidyl esters (diglycidyl tetrahydrophthalate, etc.), and epoxidized long-chain unsaturated compounds (epoxidized soybean oil, epoxidized polybutadiene, etc.).

As the oxetane compound, known compounds can be used. -oxetanylmethyl)ether, 2-hydroxypropyl(3-ethyl-3-oxetanylmethyl)ether, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, oxetanylsilsesquioxetane and phenol novolac oxetane etc.

As the ethylenically unsaturated compound, known cationic polymerizable monomers can be used, including aliphatic monovinyl ethers, aromatic monovinyl ethers, polyfunctional vinyl ethers, styrene and cationic polymerizable nitrogen-containing monomers.

Aliphatic monovinyl ethers such as methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether and cyclohexyl vinyl ether; aromatic monovinyl ethers such as 2-phenoxyethyl vinyl ether, phenyl vinyl ether and p-methoxyphenyl vinyl ether; and polyfunctional vinyl ethers such as butane. diol-1,4-divinyl ether and triethylene glycol divinyl ether; styrenes such as styrene, α-methylstyrene, p-methoxystyrene and tert-butoxystyrene; cationic polymerizable nitrogen-containing monomers such as N- Bicycloorthoesters such as vinylcarbazole and N-vinylpyrrolidone include 1-phenyl-4-ethyl-2,6,7-trioxabicyclo[2.2.2]octane and 1-ethyl-4-hydroxymethyl- 2,6,7-trioxabicyclo-[2.2.2]octane and the like, spiroorthocarbonates such as 1,5,7,11-tetraoxaspiro[5.5]undecane and 3,9-dibenzyl- 1,5,7,11-tetraoxaspiro[5.5]undecane, spiro orthoesters such as 1,4,6-trioxaspiro[4.4]nonane, 2-methyl-1,4,6 -trioxaspiro[4.4]nonane and 1,4,6-trioxaspiro[4.5]decane.

Among these cationic polymerizable compounds, epoxy compounds, oxetane compounds and vinyl ethers are preferred, and epoxy compounds and oxetane compounds are particularly preferred. "Denacol" which is a polyfunctional epoxy compound EX-810, EX-850, EX-821, EX-830, EX-841, EX-201, EX-211, EX-212, EX-252, EX-920EX-991L (trade names, both manufactured by Nakase ChemteX Co., Ltd.), "Epiclon" EXA-4850, HP-7250 (trade names, manufactured by DIC Corporation), YL-980, YL-983, YX-6677 ( (trade names, all manufactured by Mitsubishi Chemical Corporation), "Celoxide" 2021P, 2081 (trade names, manufactured by Daicel Corporation), "ADEKA GLYCIROL" ED-503, ED-506, ED-523T, ED505 (trade names, all manufactured by ADEKA Corporation), "Showfree" CDMDG, PETG, BATG (trade names, manufactured by Showa Denko K.K.), polyfunctional oxetane compounds "ETERNACOLL" OXBP, OXIPA (trade names) name, both manufactured by Ube Industries, Ltd.), “Epocalic” DE-102, DE-103 (trade names, manufactured by ENEOS Corporation), “Aron oxetane” OXT-121, OXT-191, OXT-221 (trade name, both manufactured by Toagosei Co., Ltd.) and the like. From the viewpoint that the epoxy compound containing a nitrogen atom has improved compatibility with the alkali-soluble polyimide (A), fine pattern workability can be obtained, and a good glass transition temperature and good mechanical properties are not reduced. preferable. Further examples of epoxy compounds containing an isocyanurate skeleton include triglycidyl isocyanurate TEPIC-S, TEPIC-L, TEPIC-VL, TEPIC-PASB22, and TEPIC-FL (trade names, all manufactured by Nissan Chemical Industries, Ltd.). ), etc.
These photopolymerizable compounds are used alone or in combination of two or more.

The content of the photopolymerizable compound (B) in the photosensitive resin composition is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, relative to 100 parts by mass of the alkali-soluble polyimide (A), and 30 parts by mass. The above is more preferable. When the content is 10 parts by mass or more, it is possible to reduce film loss in the exposed portion during development. On the other hand, the content of the photopolymerizable compound (B) in the photosensitive resin composition is preferably 200 parts by mass or less, more preferably 150 parts by mass or less, relative to 100 parts by mass of the alkali-soluble polyimide (A). 120 parts by mass or less is more preferable. By making it 200 parts by mass or less, the heat resistance of the cured film can be improved.

Any one of the compounds represented by the general formulas (4), (5) and (6) is preferably contained as the photopolymerizable compound (B).

In general formula (4), R ¹⁰ represents a hydrocarbon group having 1 to 5 carbon atoms, and R ¹¹ represents hydrogen or a methyl group. Z represents an organic group. a represents an integer of 0-1, and b represents an integer of 2-10. Preferably, a is 0. When Z does not have a cyclic skeleton, b is preferably 4 to 8. When Z has a cyclic skeleton, b is preferably 2 to 4. When Z has a cyclic skeleton, the cyclic skeleton is an alicyclic ring. A skeleton is preferred.

In general formulas (5) and (6), R ¹² represents a hydrocarbon group having 1 to 5 carbon atoms, and R ¹³ represents hydrogen, methyl group or ethyl group. Z represents an organic group. c represents an integer of 0-2, and d represents an integer of 2-10.

When the total mass of the photopolymerizable compound (B) is 100% by mass, the content of the compounds represented by general formulas (4) to (6) is preferably 70% by mass or more and 100% by mass or less. , more preferably 80% by mass or more and 100% by mass or less, more preferably 90% by mass or more and 100% by mass or less. The heat resistance and elastic modulus of the cured film can be improved.

Furthermore, the photopolymerizable compound (B) represented by the general formulas (4) to (6) in the photosensitive resin sheet of the present invention does not have a cyclic structure and has a photopolymerizable functional group equivalent weight of 80 to 120 g/eq. It is preferable to contain a photopolymerizable compound (hereinafter referred to as (BH) component). By containing the (BH) component, it is possible to increase the sensitivity of the composition during photolithographic processing. Moreover, the heat resistance and elastic modulus of the cured film can be improved.

The number of functional groups of the (BH) component is preferably 2 or more, more preferably 3 or more. By setting the number of functional groups to 3 or more, it is possible to improve the heat resistance of the cured film. On the other hand, the number of functional groups of the component (BH) is preferably 16 or less, more preferably 12 or less, and more preferably 8 or less. By setting the number of functional groups to 16 or less, it becomes possible to suppress the occurrence of cracks in the cured film.

Specific examples of the component (BH) include trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, ditrimethylolpropane tetraacrylate, Ditrimethylolpropane tetramethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, polypentaerythritol acrylate, polypentaerythritol methacrylate, and the like, but are limited to these. not.

The photopolymerizable compound (B) represented by the general formulas (4) to (6) is a photopolymerizable compound having an alicyclic structure and a photopolymerizable functional group equivalent weight of 130 to 200 g/eq (hereinafter referred to as (BL) component) is preferably contained. By containing the component (BL), the elongation of the cured film can be improved and the water absorption can be reduced.

The number of functional groups of the component (BL) is preferably 2 or more. By setting the number of functional groups to 2 or more, the heat resistance of the cured film can be improved. On the other hand, the number of functional groups of the component (BL) is preferably 6 or less, more preferably 4 or less. By setting the number of functional groups to 6 or less, the occurrence of cracks in the cured film can be suppressed.

Specific examples of the component (BL) include dimethyloltricyclodecane diacrylate, dimethyloltricyclodecane dimethacrylate, 1,3-adamantane diacrylate, 1,3-adamantane dimethacrylate, 1,3,5- adamantane triacrylate, 1,3,5-adamantane trimethacrylate, 5-hydroxy-1,3-adamantane diacrylate, 5-hydroxy-1,3-adamantane dimethacrylate, bis-(2-acryloxyethyl)isocyanurate, Tris-(2-acryloxyethyl) isocyanurate, ethylene oxide-modified bisphenol A diacrylate and the like can be mentioned, but not limited to these.

[Photopolymerization initiator (C)]
The photosensitive resin composition forming the photosensitive resin layer in the photosensitive resin sheet of the present invention contains a photopolymerization initiator (C). By containing the photopolymerization initiator (C), the polymerization of the photopolymerizable compound (B) described above proceeds due to the active species generated by actinic rays, and the exposed portion of the photosensitive resin layer is exposed to the alkaline developer. A negative pattern can be formed by insolubilization.

Examples of the photopolymerization initiator (C) are preferably photoradical generators or photoacid generators. Specific examples include benzophenones, glycines, mercaptos, oximes, acylphosphines, α-aminoalkylphenones, etc. Among them, acylphosphines, oximes, aromatic iodonium complex salts, aromatic Sulfonium complex salts and the like are preferably used. The photopolymerization initiator (C) may be used alone or in combination of two or more.

Specific examples of the photoinitiator (C) include benzophenones such as benzophenone, Michler's ketone, 4,4,-bis(diethylamino)benzophenone, and 3,3,4,4,-tetra(t-butylperoxycarbonyl)benzophenone. benzylidenes such as 3,5-bis(diethylaminobenzylidene)-N-methyl-4-piperidone, 3,5-bis(diethylaminobenzylidene)-N-ethyl-4-piperidone, 7-diethylamino-3-nonylcoumarin , 4,6-dimethyl-3-ethylaminocoumarin, 3,3-carbonylbis(7-diethylaminocoumarin), 7-diethylamino-3-(1-methylmethylbenzimidazolyl)coumarin, 3-(2-benzothiazolyl)-7 - coumarins such as diethylaminocoumarin, anthraquinones such as 2-t-butylanthraquinone, 2-ethylanthraquinone, 1,2-benzanthraquinone, benzoins such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, 2,4 - Thioxanthones such as dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, 2-isopropylthioxanthone, ethylene glycol di(3-mercaptopropionate), 2-mercaptobenzthiazole, 2-mercaptobenzoxanthone mercaptos such as sol, 2-mercaptobenzimidazole, N-phenylglycine, N-methyl-N-phenylglycine, N-ethyl-N-(p-chlorophenyl)glycine, N-(4-cyanophenyl)glycine glycines, 1-phenyl-1,2-butanedione-2-(o-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-methoxycarbonyl)oxime, 1-phenyl-1, 2-propanedione-2-(o-ethoxycarbonyl) oxime, 1-phenyl-1,2-propanedione-2-(o-benzoyl) oxime, bis(α-isonitrosopropiophenone oxime) isophthal, 1, 2-octanedione-1-[4-(phenylthio)phenyl]-2-(o-benzoyloxime), ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl ]-1-(o-acetyloxime) and other oximes, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and other acylphos Fins, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropane-1 -one and other α-aminoalkylphenones, 2,2′-bis(o-chlorophenyl)-4,4′,5,5′-tetraphenylbiimidazole, diphenyliodonium tetrakis(pentafluorophenyl)borate, diphenyliodonium aromatic iodonium complex salts such as hexafluorophosphate, diphenyliodonium hexafluoroantimonate and di(4-nonylphenyl)iodonium hexafluorophosphate;

Examples of particularly preferred acylphosphines and oximes include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 1- Phenyl-1,2-propanedione-2-(o-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(o-benzoyl)oxime, bis(α-isonitrosopropiophenone oxime) isophthal, 1,2-octanedione-1-[4-(phenylthio)phenyl]-2-(o-benzoyloxime)], ethanone-1-[9-ethyl-6-(2-methylbenzoyl)-9H- Carbazol-3-yl]-1-(o-acetyloxime), ADEKA Co., Ltd. ADEKA Arkles (registered trademark) N-1919, NCI-831, NCI-930, NCI-730, BASF Corporation "Irgacure "OXE-01, OXE-02, OXE-03, OXE-04, 250, 270, San-Apro Co., Ltd. CPI-110B, CPI-110S, CPI-210S, CPI-310B, CPI-310S, CPI-310FG, CPI -410B.

The content of the photopolymerization initiator (C) in the photosensitive resin composition is preferably 0.5 parts by mass or more, and is 1 part by mass or more, relative to 100 parts by mass of the alkali-soluble polyimide (A). is more preferable, and 2 parts by mass or more is even more preferable. By setting the content of the photopolymerization initiator (C) to 0.5 parts by mass or more, the sensitivity of the photosensitive resin composition to exposure can be improved. On the other hand, the content of the photopolymerization initiator (C) in the photosensitive resin composition is preferably 30 parts by mass or less in 100 parts by mass of the alkali-soluble polyimide (A), and is 25 parts by mass or less. is more preferable, and 20 parts by mass or less is even more preferable. By setting the content of the photopolymerization initiator (C) to 30 parts by mass or less, it becomes possible to allow light to penetrate deep into the photosensitive resin sheet, and a favorable pattern shape can be obtained after development.

[Colorant (D)]
The photosensitive resin composition forming the photosensitive resin layer in the photosensitive resin sheet of the present invention contains a coloring agent (D). The colorant (D) of the present invention refers to an organic material that has an absorption maximum in the visible light region and is soluble in an organic solvent. By containing the coloring agent (D) in the photosensitive resin composition, light having a wavelength absorbed by the coloring agent (D) is blocked from the light transmitted through the photosensitive resin sheet or the light reflected from the photosensitive resin sheet. It is possible to impart light shielding properties. By imparting a light-shielding property, it becomes possible to determine with high accuracy defects and defect points contained in the photosensitive resin sheet and the cured film of the present invention, so that the yield improvement and the reliability improvement of the product are improved. can be done. In addition, it is preferable that the cured film obtained after exposing and heat-curing the photosensitive resin sheet described later is in a colored state without fading, and the coloring material has weather resistance and heat resistance that do not discolor in the post-process. It is preferable that the coloring material has Furthermore, it is preferable that the transparency is high in the wavelength region of actinic rays in the exposure process.

As described above, the coloring material (D) contains at least an organic dye, and examples thereof include a method using one type of dye, a method using a combination of two or more types of dyes, and the like.

The colorant (D) preferably has an absorption maximum at 500 to 800 nm, more preferably 530 to 750 nm, more preferably 530 to 700 nm. If the maximum absorption wavelength of the coloring material is less than 500 nm, absorption of actinic rays occurs in the exposure process, and the exposure sensitivity of the coating film may decrease. When the maximum absorption wavelength of the coloring material is 500 nm or more, the deterioration of the exposure sensitivity of the coating film can be suppressed, and a pattern with a favorable shape can be obtained. On the other hand, when the maximum absorption wavelength of the coloring material is longer than 800 nm, the absorption in the visible light region becomes weak, and the visibility is lowered, so it may be difficult to distinguish defects, defect locations, and pattern defect locations of the coating film. .

The coloring material (D) is preferably an organic dye. Among the organic dyes used as the coloring agent (D), by selecting a coloring agent that is soluble in an organic solvent or the like, the coloring agent can be easily dispersed when the coating material is prepared, and uneven distribution of the composition in the coating material can be suppressed. Therefore, the uniformity of the shielding ability in the photosensitive resin sheet can be improved. Examples of the coloring agent (D), which is an organic dye soluble in an organic solvent, include oil-soluble dyes, disperse dyes, reactive dyes, and acid dyes.

The skeleton structure of the organic dye includes, but is not limited to, anthraquinone, azo, phthalocyanine, methine, oxazine, quinoline, triarylmethane, and xanthene. Among these, anthraquinone, triarylmethane, and xanthene are preferred because of their solubility in organic solvents, weather resistance from the viewpoint of exposure process and curing film fading, and electrical reliability after heat curing. It preferably has a skeleton structure. Furthermore, from the viewpoint of discoloration during the heat curing step, the coloring agent (D) preferably contains an anthraquinone compound having heat resistance. Each of these dyes may be used alone or as a metal-containing complex salt. Specifically, Sumilan, Lanyl dyes (manufactured by Sumitomo Chemical Co., Ltd.), Orasol, Oracet, Filamid, Irgasperse dyes (manufactured by Ciba Specialty Chemicals Co., Ltd.), Zapon, Neozapon, Neptune, Acidol dyes (BASF ( Co., Ltd.), Kayaset, Kayakalan dyes (manufactured by Nippon Kayaku Co., Ltd.), Valifast Colors dyes (manufactured by Orient Chemical Industry Co., Ltd.), Savinyl, Sandoplast, Polysynthren, Lanasyn dyes (manufactured by Clariant Japan Co., Ltd.), Aizen Spilon dyes (manufactured by Hodogaya Chemical Industry Co., Ltd.), functional dyes (manufactured by Yamada Chemical Industry Co., Ltd.), Plast Color dyes, Oil Color dyes (manufactured by Arimoto Chemical Industry Co., Ltd.), etc. It is not limited to them. These dyes are used singly or in combination.

Specific examples of organic dyes used for these are indicated by color index (CI) numbers. Examples of yellow dyes include Solvent Yellow 16, 18, 21, 33, 34, 35, 43, 54, 93, 112, 128, 157, 159, 160, 201, Acid Yellow 17, 19, 23, 25, 39. , 40, 42, 44, 49, 50, 61, 64, 76, 79, 110, 127, 135, 143, 151, 159, 169, 174, 190, 195, 196, 197, 199, 218, 219, 222 227, basic yellow 1, 2, 4, 11, 13, 14, 15, 19, 21, 23, 24, 25, 28, 29, 32, 36, 39, or 40.

Examples of red dyes include Direct Red 2, 4, 26, 28, 31, 39, 62, 63, 72, 75, 76, 79, 80, 81, 83, 84, 89, 111, 173, 184, 207 , 211, 212, 225, 226, 240, 241, 242, 243 or 247, acid red 35, 42, 51, 52, 57, 62, 80, 82, 111, 114, 118, 119, 127, 128, 131 , 143, 145, 151, 154, 157, 158, 211, 249, 254, 257, 261, 263, 266, 289, 299, 301, 305, 319, 336, 337, 361, 396 or 397, basic red 1 , 12, 13, 14, 15, 18, 22, 23, 24, 25, 27, 29, 35, 36, 38, 39, 45 or 46, solvent red 18, 52, 111, 135, 168, 179, 207 , Sudan, Oil Red O and the like.

Examples of violet dyes include direct violet 7, 9, 47, 48, 51, 66, 90, 93, 94, 95, 98, 100 or 101, acid violet 5, 9, 11, 34, 43, 47, 48 , 51, 75, 90, 103 or 126, reactive violet 1, 3, 4, 5, 6, 7, 8, 9, 16, 17, 22, 23, 24, 26, 27, 33 or 34, basic violet 1, 2, 3, 7, 10, 15, 16, 20, 21, 25, 27, 28, 35, 37, 39, 40 or 48 and the like.

Examples of blue dyes include Direct Blue 55, 68, 83, 95, 158, 172, 190, 194, 196, 198, 211, 218, 226, 244, 271, 273, 274 or 277, Acid Blue 5, 13, 40, 52, 55, 56, 69, 86, 98, 142, 143, 145, 200, 202, 208, 209, 210, 243 or 252, reactive blue 11, 20, 24, 31, 34, 36, 60 , 76, 90, 108, 128, 131, 140, 146 or 151, basic blue 8, 12, 46, 48, 67, 75, 89, 91, 105, 106, 107, 108, 110, 115, 129, 131 , 135 or 137, solvent blue 7, 12, 34, 36, 44, 45, 49, 50, 52, 53, 78, 82, 87, 91, 92, 93, 94, 95, 97, 98, 99, 103 , 105, 109, 110, 111, 112, 116 or 134, Disperse Blue 9, 31, 59, 70, 149, 189, 190, 192, 200, 201, 205, 222, 224, 225, 227, 240 247, 250, 251, 252, 253, 254, 257, 266, 267, 270, 297, 301, 310 or 312 and the like.

Examples of green dyes include Acid Green 1, 5, 16, 65, 82, 83, 92, 94 or 104, Basic Green 10, Direct Green 6, 27, 30, 34 or 68 and the like. Dyes other than these can also be used. In particular, by using violet dyes and blue dyes that absorb little actinic rays in the exposure step, it is possible to suppress an increase in the amount of exposure and to prevent the pattern shape from becoming a reverse tapered shape.

The coloring material (D) used in the present invention preferably has heat resistance such that it does not decompose and/or sublime when a cured film obtained by heating and curing the photosensitive resin sheet described later is formed.

The content of the coloring material (D) when used in the present invention is preferably 0.1 parts by mass or more and 50 parts by mass or less, and 1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the alkali-soluble polyimide (A). is more preferable, and 3 parts by mass or more and 8 parts by mass or less is particularly preferable. By setting the content of the coloring material (D) to 0.1 part by mass or more, it is possible to absorb light of a visible wavelength corresponding to an inspection machine to be described later in the inspection step. Further, by setting the amount to 50 parts by mass or less, it is possible to obtain a pattern with a favorable shape while maintaining the adhesive strength between the photosensitive resin sheet and the substrate, the heat resistance of the cured film after heat treatment, and the mechanical properties.

In the present invention, the organic dye used as the coloring material (D) may be subjected to surface treatment such as rosin treatment, acidic group treatment, or basic group treatment, if necessary. In some cases, the colorant (D) can also be used together with a dispersant. Examples of dispersants include cationic, anionic, nonionic, amphoteric, silicone and fluorine surfactants.

<Thermochromic compound>
The photosensitive resin sheet of the present invention may further contain a thermochromic compound. The thermochromic compound is a thermochromic compound that develops color in a heat treatment step described below and has an absorption maximum at 350 nm or more and 700 nm or less. The thermochromic compound is preferably a thermochromic compound that exhibits little absorption in the exposure wavelength region of the photosensitive resin sheet, ie, 350 to 450 nm. By using a thermochromic compound in combination with the component (D), the absorption of the photosensitive resin sheet in the exposure wavelength range of 350 to 450 nm is reduced, and the decrease in sensitivity can be suppressed.

　The thermochromic compound does not shield visible light or ultraviolet light before heat curing, so it is difficult to accurately determine defects and defects in the resin sheet. In addition, since the shielding property after heat curing is weaker than that of a coloring agent added in the same amount, it is necessary to add a large amount of thermochromic compound in order to distinguish defects and defects. Strength decreases. Therefore, it is preferable to use the thermochromic compound together with the colorant (D) in accordance with various properties.

In the present invention, the thermochromic compound is preferably a compound that develops color at a temperature higher than 120°C, more preferably a thermochromic compound that develops color at a temperature higher than 180°C. The higher the color-developing temperature of the thermochromic compound, the better the heat resistance under high-temperature conditions, and the less the color fades due to long-term irradiation with ultraviolet light and visible light, and the better the light resistance.

In the present invention, the thermochromic compound may be a general heat-sensitive dye or pressure-sensitive dye, or may be another compound. Examples of thermochromic compounds include those that develop color by changing their chemical structure and charge state due to the action of acidic groups coexisting in the system during the heat treatment process, or those that undergo a thermal oxidation reaction due to the presence of oxygen in the air. and the like are exemplified.

Examples of the skeleton structure of the thermochromic compound include a triarylmethane skeleton, a diarylmethane skeleton, a fluorane skeleton, a bislactone skeleton, a phthalide skeleton, a xanthene skeleton, a rhodamine lactam skeleton, a fluorene skeleton, a phenothiazine skeleton, a phenoxazine skeleton, and a spiropyran skeleton. be done. Among them, a triarylmethane skeleton is preferable because of its high thermal coloring temperature and excellent heat resistance.

Specific examples of the triarylmethane skeleton include 2,4′,4″-methylidenetrisphenol, 4,4′,4″-methylidenetrisphenol, 4,4′-[(4-hydroxyphenyl) methylene]bis(benzenamine), 4,4'-[(4-aminophenyl)methylene]bisphenol, 4,4'-[(4-aminophenyl)methylene]bis[3,5-dimethylphenol], 4, 4′-[(2-hydroxyphenyl)methylene]bis[2,3,6-trimethylphenol], 4-[bis(4-hydroxyphenyl)methyl]-2-methoxyphenol, 4,4′-[(2 -hydroxyphenyl)methylene]bis[2-methylphenol], 4,4′-[(4-hydroxyphenyl)methylene]bis[2-methylphenol], 4-[bis(4-hydroxyphenyl)methyl]-2 -ethoxyphenol, 4,4'-[(4-hydroxyphenyl)methylene]bis[2,6-dimethylphenol], 2,2'-[(4-hydroxyphenyl)methylene]bis[3,5-dimethylphenol ], 4,4′-[(4-hydroxy-3-methoxyphenyl)methylene]bis[2,6-dimethylphenol], 2,2′-[(2-hydroxyphenyl)methylene]bis[2,3, 5-trimethylphenol], 4,4′-[(4-hydroxyphenyl)methylene]bis[2,3,6-trimethylphenol], 4,4′-[(2-hydroxyphenyl)methylene]bis[2- cyclohexyl-5-methylphenol], 4,4′-[(4-hydroxyphenyl)methylene]bis[2-cyclohexyl-5-methylphenol], 4,4′-[(3-methoxy-4-hydroxyphenyl) methylene]bis[2-cyclohexyl-5-methylphenol], 4,4′-[(3,4-dihydroxyphenyl)methylene]bis[2-methylphenol], 4,4′-[(3,4-dihydroxy phenyl)methylene]bis[2,6-dimethylphenol], 4,4′-[(3,4-dihydroxyphenyl)methylene]bis[2,3,6-trimethylphenol], and the like. These are used singly or in combination. The hydroxyl group-containing compound having a triarylmethane skeleton may be used as a quinonediazide compound by ester-bonding the sulfonic acid of naphthoquinonediazide to the compound.

In the present invention, the content when containing a thermochromic compound is preferably 0.5 to 50 parts by mass, more preferably 1 to 10 parts by mass, with respect to 100 parts by mass of the alkali-soluble polyimide (A). ~10 parts by mass is more preferable. When the content of the thermochromic compound is 0.5 parts by mass or more, the transmittance of the cured film in the ultraviolet and visible light regions can be reduced. Moreover, if it is 50 parts by mass or less, the heat resistance and strength of the cured film can be maintained.

<Sensitizer>
The photosensitive resin sheet of the present invention may contain a known sensitizer in order to absorb actinic rays such as ultraviolet rays and provide the absorbed light energy to the photopolymerization initiator. Preferred examples of sensitizers include anthracene compounds having alkoxy groups at the 9- and 10-positions (9,10-dialkoxy-anthracene derivatives). Examples of alkoxy groups include C1-C4 alkoxy groups such as methoxy, ethoxy and propoxy groups. The 9,10-dialkoxy-anthracene derivative may further have a substituent. Examples of substituents include halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, C1 to C4 alkyl groups such as a methyl group, an ethyl group and a propyl group, a sulfonic acid alkyl ester group, and a carboxylic acid alkyl ester group. etc. Examples of the alkyl in the sulfonic acid alkyl ester group and carboxylic acid alkyl ester include C1-C4 alkyl such as methyl, ethyl and propyl. The substitution position of these substituents is preferably 2-position.

[Inorganic particles]
The photosensitive resin composition forming the photosensitive resin layer in the photosensitive resin sheet of the present invention preferably contains inorganic particles. By containing the inorganic particles, it is possible to improve mechanical properties such as elastic modulus and chemical resistance of the cured film formed by heat-curing the photosensitive resin layer. In addition, it is possible to change the light transmittance of the cured film and improve the visibility of defects and missing portions of the pattern.

Examples of inorganic particles include silicon oxides such as talc, amorphous silica, crystalline silica, fused silica and spherical silica, glass particles composed of various metal oxides, titanium oxide, aluminum oxide, calcium oxide, magnesium oxide, oxide Zinc, calcium carbonate, magnesium carbonate, calcium hydroxide, aluminum hydroxide, magnesium hydroxide, mica, hydrotalcite, aluminum silicate, magnesium silicate, calcium silicate, potassium titanate, magnesium sulfate, calcium sulfate, magnesium phosphate, nitriding Boron, aluminum borate, aluminum hydrate, hydrated gypsum, barium sulfate and the like. These are used singly or in combination. In particular, from the viewpoint of insulation reliability, silicon oxide, titanium oxide, aluminum oxide, magnesium oxide, aluminum hydroxide, and glass particles can be preferably used. Further, silicon oxide is preferable from the viewpoint of reducing the linear expansion of a cured film composed of a photosensitive resin layer.

The average particle diameter D50 of the inorganic particles is preferably 30 to 150 nm, more preferably 40 to 120 nm, even more preferably 60 to 120 nm. When the average particle diameter D50 of the inorganic particles is 30 nm or more, the inorganic particles are well dispersed in the paint, so that a pattern with a uniform line width can be obtained. By setting the average particle diameter D50 of the inorganic particles to 150 nm or less, the smoothness of the surface of the photosensitive resin sheet and the surface of the cured film after patterning can be improved. Moreover, scattering of ultraviolet rays during exposure can be suppressed, and a high-resolution pattern can be obtained. The average particle diameter D50 of the inorganic particles is the value of the 50% volume particle diameter measured using a particle size distribution meter using a dynamic light scattering particle size distribution meter.

The shape of the inorganic particles includes, but is not particularly limited to, spherical, needle-like, fibrous, amorphous granular, plate-like, and crushed shapes.

The content of the inorganic particles is preferably 1% by mass or more, more preferably 3% by mass or more, when the total mass of the solid content in the photosensitive resin layer of the present invention is 100% by mass. , more preferably 5% by mass or more. On the other hand, the content of the inorganic particles is preferably 40% by mass or less with respect to 100% by mass of the total solid content in the photosensitive resin layer, from the viewpoint of improving pattern processability and elongation. % mass % or less, and even more preferably 20 mass % or less. By setting the content of the inorganic particles to 1% by mass or more, the cured film has improved mechanical properties, chemical resistance, and visibility of pattern defects. On the other hand, by setting the content of the inorganic particles to 40% by mass or less, the photosensitive resin sheet has good lamination properties and fine pattern formation becomes possible.

In addition, in order to disperse the inorganic particles in the photosensitive resin layer of the photosensitive resin sheet, surface treatment with a silane coupling agent may be performed as necessary. Specific examples of silane coupling agents include Shin-Etsu Chemical's vinyltrimethoxysilane (KBM-1003), 3-glycidoxypropyltrimethoxysilane (KBM-403), 2-(3,4-epoxycyclohexyl)ethyl Trimethoxysilane (KBM-303), trimethoxysilane succinic anhydride (KBM-967TR-1), 3-methacryloxypropyltrimethoxysilane (KBM-503), N-2-(aminoethyl)-3-aminopropyl Trimethoxysilane (KBM-603), N-phenyl-3-aminopropyltrimethoxysilane (KBM-573) and the like can be used. Surface treatment of inorganic particles includes a dry surface treatment method in which a silane coupling agent and a small amount of water are added to the inorganic particles and stirred, and a wet surface treatment method in which inorganic particles and a silane coupling agent are added in an organic solvent and stirred. methods of processing, and the like. In addition, a method of performing a wet surface treatment in which inorganic particles and a silane coupling agent are added to the photosensitive resin composition and stirred is also included.

<Thermal cross-linking agent>
The photosensitive resin layer of the photosensitive resin sheet of the present invention preferably contains a thermal crosslinking agent. The thermal cross-linking agent is a component that is cured by heat treatment after patterning, and can improve the heat resistance, mechanical properties and chemical resistance of the cured product. The thermal cross-linking agent is preferably a compound containing at least one of alkoxymethyl, methylol, epoxy and oxetane groups, and contains at least two of alkoxymethyl, methylol, epoxy and oxetane groups. Compounds are more preferred.

Among thermal cross-linking agents, compounds having an alkoxymethyl group or a methylol group include, for example, 46DMOC, 46DMOEP (trade names, manufactured by Asahi Organic Chemicals Industry Co., Ltd.), DML-PC, DML-PEP, DML-OC, and DML. -OEP, DML-34X, DML-PTBP, DML-PCHP, DML-OCHP, DML-PFP, DML-PSBP, DML-POP, DML-MBOC, DML-MBPC, DML-MTrisPC, DML-BisOC-Z, DML -BisOCHP-Z, DML-BPC, DMLBisOC-P, DMOM-PC, DMOM-PTBP, DMOM-MBPC, TriML-P, TriML-35XL, TML-HQ, TML-BP, TML-pp-BPF, TML-BPE , TML-BPA, TML-BPAF, TML-BPAP, TMOM-BP, TMOM-BPE, TMOM-BPA, TMOM-BPAF, TMOM-BPAP, HML-TPPHBA, HML-TPHAP, HMOM-TPPHBA, HMOM-TPHAP, HMOM -HAP (above, product name, manufactured by Honshu Chemical Industry Co., Ltd.), "NIKALAC" (registered trademark) MX-290, MX-280, MX-270, MX-279, MW-100LM, MX-750LM (above, product name , manufactured by Sanwa Chemical Co., Ltd.).

Among thermal cross-linking agents, compounds having an epoxy group include, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polymethyl(glycidyloxypropyl), epoxy group containing silicone and the like. Specifically, "Epiclon" (registered trademark) 850-S, HP-4032, HP-7200, HP-820, HP-4700, EXA-4710, HP-4770, EXA-859CRP, EXA-1514, EXA- 4880, EXA-4850-150, EXA-4850-1000, EXA-4816, EXA-4822 (trade names, manufactured by Dainippon Ink and Chemicals), "Rikaresin" (registered trademark) BEO-60E, BPO-20E , HBE-100, DME-100, L-200, BPO-20E, BEO-60E (trade names, manufactured by Shin Nippon Rika Co., Ltd.), ADEKA RESIN EP-4003S, EP-4000S, EP-4005, EP-4100G, (above, product names, manufactured by ADEKA), PG-100, CG-500, EG-200 (above, product names, manufactured by Osaka Gas Chemicals Co., Ltd.), NC-3000, NC-6000 (above, product names, manufactured by Nippon Kayaku Yakusha), "EPOX" (registered trademark)-MK R508, R540, R710, R1710, VG3101L, VG3101M80 (trade names, manufactured by Printec), "Celoxide" (registered trademark) 2021P, 2081, 2083, 2085 (trade name, manufactured by Daicel Chemical Industries, Ltd.) and the like.

Two or more thermal cross-linking agents can be used in combination.
The content of the thermal cross-linking agent in the photosensitive resin sheet of the present invention is preferably 5% by mass or more, more preferably 10% by mass or more, and 15% by mass or more relative to 100% by mass of the alkali-soluble polyimide (A). is more preferred. By setting the content of the thermal cross-linking agent to 5% by mass or more, the heat resistance, mechanical properties and chemical resistance of the cured product can be improved. On the other hand, the content of the thermal crosslinking agent is preferably 100% by mass or less, more preferably 50% by mass or less, and 40% by mass or less with respect to 100% by mass of the alkali-soluble polyimide (A). is more preferred. By setting the content of the thermal cross-linking agent to 100% by mass or less, the storage stability of the photosensitive resin composition can be improved. In addition, curing shrinkage can be suppressed in the heating process for obtaining a cured film.

<Other ingredients>
Moreover, the photosensitive resin sheet of the present invention may further contain a polymerization inhibitor. Since the exciton concentration is adjusted by containing the polymerization inhibitor, a pattern having a rectangular cross section can be formed. In addition, the polymerization inhibitor can suppress excessive photoresponsivity, and the exposure margin can be widened. Furthermore, since the increase in the viscosity of the photosensitive resin composition paint and sheet can be suppressed, the quality can be improved.

Examples of polymerization inhibitors include, for example, hydroquinone, hydroquinone monomethyl ether, phenolic polymerization inhibitors such as t-butylcatechol, phenothiazine, 2-methoxyphenothiazine, 1-naphthol, 1,4-dihydroxynaphthalene, 4-methoxy- 1-naphthol, 1-methoxynaphthalene, 1,4-dimethoxynaphthalene, 2,6-dimethoxynaphthalene, 2,7-dimethoxynaphthalene, 1,4-diethoxynaphthalene, 2,6-diethoxynaphthalene, 2,7- Diethoxynaphthalene, 2,6-dibutoxynaphthalene, 2-ethyl-1,4-diethoxynaphthalene, 1,4-dibutoxynaphthalene, 1,4-diphenethyloxynaphthalene, 1,4-naphthoquinone, 2-hydroxy -1,4-naphthoquinone, 2-methyl-1,4-naphthoquinone, 9-butoxyanthracene, 9,10-butoxyanthracene, 9-anthrone, 9,10-anthraquinone, 2-ethyl-9,10-anthraquinone, etc. mentioned. These polymerization inhibitors are used alone or in combination of two or more.

In addition, the photosensitive resin sheet of the present invention can further contain an adhesion improver. The adhesion improving material improves adhesion between the substrate and the circuit forming material formed on the substrate with the photosensitive resin layer in the photosensitive resin sheet and/or their cured film. Examples of substrates include silicon wafers, organic circuit substrates, LTCC and HTCC ceramic substrates, and inorganic circuit substrates. Examples of organic circuit boards include glass-based copper-clad laminates such as glass cloth and epoxy copper-clad laminates, composite copper-clad laminates such as glass nonwoven fabrics and epoxy copper-clad laminates, polyetherimide resin substrates, and polyetherimide resin substrates. Examples include heat-resistant/thermoplastic substrates such as etherketone resin substrates and polysulfone resin substrates, and flexible substrates such as polyester copper-clad film substrates and polyimide copper-clad film substrates. Examples of inorganic circuit substrates include ceramic substrates such as alumina substrates, aluminum nitride substrates and silicon carbide substrates, and metal substrates such as aluminum base substrates, copper base substrates and iron base substrates. Examples of circuit constituent materials include conductors containing gold, silver, copper, aluminum, nickel, chromium, titanium, etc., and resistors such as inorganic oxides.

Examples of adhesion improvers include vinyltrimethoxysilane (KBM-1003), 3-glycidoxypropyltrimethoxysilane (KBM-403), and 2-(3,4-epoxycyclohexyl) manufactured by Shin-Etsu Chemical Co., Ltd. ) Ethyltrimethoxysilane (KBM-303), succinic anhydride trimethoxysilane (KBM-967TR-1), 3-methacryloxypropyltrimethoxysilane (KBM-503), 3-acryloxypropyltrimethoxysilane (KBM- 5103), N-2-(aminoethyl)-3-aminopropyltrimethoxysilane (KBM-603), N-phenyl-3-aminopropyltrimethoxysilane (KBM-573), tris-(trimethoxysilylpropyl) Isocyanurate (KBE-9007N), 3-mercaptopropyltrimethoxysilane (KBM-803), Momentive's Silquest (registered trademark) A-151, A-174, A-187, A-1871, CoatOSil ( (registered trademark) 2287, silane coupling agents such as MP200, titanium acetylacetonate (TC-100) manufactured by Matsumoto Fine Chemical Co., Ltd., titanium chelating agents such as titanium tetraacetylacetonate (TC-401), Johoku Chemical Industry Co., Ltd. 1,2,3-benzotriazole (BT-120), carboxybenzotriazole (CBT-1, CBT-SG), 5-carboxybenzotriazole (CBT-5), 1-(1',2'-)dicarboxy Ethyl)benzotriazole (BT-M), 1-[N,N-bis(2-ethylhexyl)aminomethyl]benzotriazole (BT-LX) 2,2′-[[methyl-1H-benzotriazol-1-yl ]methyl]imino]bisethanol, triazole compounds such as 5-methylbenzotriazole (5M-BTA), thiol compounds such as Karenz MT (registered trademark) PE1, BD1, NR1, TPMB manufactured by Showa Denko K.K. mentioned.

The photosensitive resin sheet of the present invention may contain organic solvents, dispersants, plasticizers, etc., if necessary.

[Method for producing photosensitive resin composition]
Next, an example of a method for producing a photosensitive resin composition for producing the photosensitive resin sheet of the present invention is shown. A first form of the photosensitive resin composition is a varnish material prepared by dissolving and diluting various raw materials in an organic solvent. Dissolving methods include ultrasonic waves, blade agitation, ball milling, and the like, and filter filtration may be performed as necessary. The filtration method is not particularly limited, but a method of filtration by pressure filtration using a filter having a retained particle size of 1 μm to 50 μm is preferred. The organic solvent to be diluted is not particularly limited, but ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ale, propylene glycol monoethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and ethylene glycol dibutyl ether. , ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, propyl acetate, butyl acetate, isobutyl acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl lactate, ethyl lactate, butyl lactate and other acetates acetone, methyl ethyl ketone, acetylacetone, methyl propyl ketone, methyl butyl ketone, methyl isobutyl ketone, cyclopentanone, ketones such as 2-heptanone, butyl alcohol, isobutyl alcohol, pentanol, 4-methyl-2-pentanol , 3-methyl-2-butanol, 3-methyl-3-methoxybutanol, diacetone alcohol and other alcohols, toluene, xylene and other aromatic hydrocarbons, others, N-methyl-2-pyrrolidone, N-cyclohexyl -2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, γ-butyrolactone and the like.

[Method for producing photosensitive resin sheet]
In the form of the photosensitive resin sheet of the present invention, a layer (hereinafter referred to as a photosensitive resin layer) made of a photosensitive resin composition is coated and dried on a film (also referred to as a support film) that supports the photosensitive resin composition. is formed on a support film. That is, the photosensitive resin sheet of the present invention is a sheet having a support film and a layer (photosensitive resin layer) formed from a photosensitive resin composition on the support film.

The support film used in the photosensitive resin sheet of the present invention is not particularly limited, but various commercially available films such as polyester films such as polyethylene terephthalate (PET) films, polyphenylene sulfide films, and polyimide films can be used. . The bonding surface between the support film and the photosensitive resin layer may be surface-treated with a silicone agent, a silane coupling agent, an aluminum chelating agent, polyurea, or the like, in order to adjust adhesion and releasability. The thickness of the support film is not particularly limited, but from the viewpoint of workability, it is preferably in the range of 10 to 100 μm, more preferably in the range of 30 to 80 μm. When the thickness of the support film is 10 μm or more, curling of the photosensitive resin sheet after the photosensitive resin composition is applied and dried can be suppressed, and the sheet can be wound up as a roll. On the other hand, if the thickness of the support film is 100 μm or less, when the photosensitive resin sheet is exposed through the support film, the exposure light spreads within the support film, resulting in deterioration of the pattern workability. Moreover, the haze of the support film is preferably 2.0% or less. If the haze is more than 2.0%, scattering of exposure light occurs, resulting in poor pattern workability.

In addition, in order to protect the photosensitive resin sheet, a protective film may be provided on the side of the photosensitive resin layer in the photosensitive resin sheet composed of the photosensitive resin layer and the support film. That is, it is preferable to form a photosensitive resin sheet in which the support film, the photosensitive resin layer, and the protective film are directly laminated in this order. As a result, the surface of the photosensitive resin layer of the photosensitive resin sheet can be protected from contaminants such as dirt and dust in the air. Protective films include polyethylene (PE) films, polypropylene (PP) films, polyester films, polyvinyl alcohol films, and the like. Moreover, the protective film is preferably such that the photosensitive resin layer and the protective film are not easily peeled off, and the adhesion strength between the photosensitive resin layer and the support film is preferably weaker.

Methods for applying the photosensitive resin composition to the support film include spin coating using a spinner, spray coating, roll coating, screen printing, blade coater, die coater, calendar coater, meniscus coater, bar coater, roll coater, A comma roll coater, a gravure coater, a screen coater, a slit die coater and the like can be used. In addition, although the coating film thickness varies depending on the coating method, the solid content concentration of the composition, the viscosity, etc., it is generally preferable that the film thickness of the photosensitive resin layer after drying is 3 μm or more and 100 μm or less.

In the photosensitive resin sheet of the present invention, the film thickness of the photosensitive resin layer is preferably 15-40 μm, more preferably 15-35 μm, even more preferably 18-35 μm. When multilayer wiring is formed using the photosensitive resin sheet of the present invention, if the film thickness of the photosensitive resin layer is 15 μm or more, the metal wiring can be satisfactorily covered with the laminate, and the insulation between the metal wiring can be ensured. can do. On the other hand, the thicker the photosensitive resin layer, the more difficult it is to perform high-definition processing, the more the shrinkage stress in the curing process increases, the more the substrate warps, and the higher the material cost. is preferably

The photosensitive resin sheet of the present invention is produced by applying the photosensitive resin composition to a support film and then heat-drying the photosensitive resin composition in a drying facility such as a hot air oven, a hot plate, or an infrared drying oven. It is obtained by layering. The drying temperature and drying time may be within a range in which the organic solvent can be volatilized, and it is preferable to appropriately set a range such that the photosensitive resin layer is in an uncured or semi-cured state. Specifically, it is preferably carried out at a temperature in the range of 40° C. to 120° C. within 1 minute to 120 minutes. Moreover, these temperatures and times may be combined and the temperature may be raised stepwise, and appropriate adjustments may be made so that the quality of the coating film after drying does not deteriorate due to roughness and foreign matter.

The photosensitive resin layer in the photosensitive resin sheet of the present invention preferably adjusts the light transmittance to actinic rays in the exposure step described later. The photosensitive resin layer preferably satisfies the following relationship B when the transmittance at 365 nm is Tb365, the transmittance at 405 nm is Tb405, and the transmittance at 436 nm is Tb436.

Relation B: At least one of formulas 3 to 5 is satisfied.

Formula 3: 3.0% ≤ Tb365 ≤ 70%
Formula 4: 3.0% ≤ Tb405 ≤ 70%
Formula 5: 3.0% ≤ Tb436 ≤ 70%
This will be explained in detail. When the photosensitive resin sheet of the present invention is exposed to ultraviolet rays having a wavelength of 405 nm in the exposure step, the transmittance Tb405 of the photosensitive resin layer at a wavelength of 405 nm when the film thickness of the photosensitive resin layer is 26 μm is 3. It is preferably 0% or more and 70% or less, more preferably 5.0% or more and 50% or less, and even more preferably 5.0% or more and 40% or less. When the transmittance Tb405 is 3.0% or more, the cross-sectional shape of the pattern becomes rectangular or forward tapered, which facilitates the formation of the metal wiring layer. On the other hand, when the transmittance is 70% or less, the photopolymerization reaction by the exposure light can proceed well.

Similarly, when the photosensitive resin sheet of the present invention is exposed to ultraviolet rays having a wavelength of 365 nm in the exposure step, the transmittance Tb365 is preferably 3.0% or more and 70% or less, and 5.0% or more and 50% or less. is more preferably 5.0% or more and 40% or less. Further, when exposing with ultraviolet light having a wavelength of 436 nm in the exposure step, the transmittance Tb436 is preferably 3.0% or more and 70% or less, more preferably 5.0% or more and 50% or less, and 5.0%. % or more and 40% or less.

Tb365, Tb405 and Tb436 can be appropriately adjusted by light absorption at each wavelength depending on the types of materials contained in the photosensitive resin sheet and their compounding ratios. In particular, the alkali-soluble polyimide (A), the photopolymerization initiator (C), the colorant (D) and the inorganic particles greatly contribute to the light transmittance at the exposure wavelength. In order to form a negative pattern, it is necessary that the photopolymerization initiator (C) efficiently absorbs the actinic rays of the exposure wavelength to promote the polymerization of the photopolymerizable compound (B). On the other hand, other materials must be capable of high electrical properties, reliability and pattern inspectability while suppressing light absorption of actinic rays. Therefore, as described above, by selecting each material and setting the content within a predetermined range, a photosensitive resin sheet and a cured film pattern having excellent pattern processability while being a thick film can be obtained.

The photosensitive resin layer in the photosensitive resin sheet of the present invention has a transmittance Tb450 at a wavelength of 450 nm of 40% or more and 95% or less, preferably 50% or more and 90% or less, and 55% or more and 80% or less. is more preferable. Here, it is important that the transmittance Tb450 of the photosensitive resin layer at a wavelength of 450 nm is 40% or more and 95% or less regardless of the film thickness. When the transmittance Tb450 is 40% or more as described above, the alignment mark can be visually recognized when aligning the photomask and the substrate. In addition, a high-definition pattern can be obtained without cracks in the patterned cured film. On the other hand, when the transmittance Tb450 is 95% or less, it is possible to visually recognize and detect foreign matter and defects attached after pattern processing.

The photosensitive resin layer in the photosensitive resin sheet of the present invention satisfies the following relationship A when the transmittance at 600 nm is Tb600 and the minimum transmittance at 500 to 800 nm is TbVL. is a sheet.

Relation A: At least one of Formula 1 and Formula 2 is satisfied.

Formula 1: 0.10% ≤ Tb600 ≤ 40%
Formula 2: 0.10% ≤ TbVL ≤ 40%
3. The photosensitive resin layer in the photosensitive resin sheet of the present invention has a transmittance Tb600 at a wavelength of 600 nm of 0.10% or more and 40% or less, preferably 1.0% or more and 20% or less. It is more preferably 0% or more and 10% or less. Here, it is important that the transmittance Tb600 of the photosensitive resin layer at a wavelength of 600 nm is 0.10% or more and 40% or less regardless of the film thickness. If the transmittance Tb600 is less than 0.1%, the content of the necessary coloring material increases, and the heat resistance and mechanical strength of the cured film deteriorate. On the other hand, if the transmittance Tb600 is greater than 40%, the internal wiring pattern is transparent in the inspection after pattern processing, which may cause erroneous detection of foreign matter and defects.

The photosensitive resin layer in the photosensitive resin sheet of the present invention has a minimum value TbVL of transmittance at 500 to 800 nm of 0.10% or more and 40% or less, and 1.0% or more and 20% or less. It is preferably 3.0% or more and 10% or less. Here, it is important that the minimum transmittance TbVL be 0.10% or more and 40% or less regardless of the film thickness. If the minimum transmittance value TbVL is less than 0.1%, the content of the required coloring material increases, and the heat resistance and mechanical strength of the cured film deteriorate. On the other hand, if the minimum transmittance value TbVL is greater than 40%, the internal wiring pattern is transparent in the inspection after pattern processing, which may cause erroneous detection of foreign matter and defects. In the inspection process after pattern processing, the wavelength of the inspection light used for inspection is selected to have the minimum transmittance in the range of 500 to 800 nm, thereby improving the visibility of defects and defects in the pattern. .

The transmittances Tb365, Tb405, Tb436, Tb450, Tb600, and TbVL of the photosensitive resin layer were obtained by laminating the photosensitive sheet resin on the transparent base material by heating roll lamination, and then peeling off the support film. The transmittance in the wavelength range of 350-800 nm is measured with a visible spectrophotometer. Transmittances Tb365, Tb405, Tb436, Tb450, Tb600, and TbVL can be obtained by measuring the transmittance of a sample laminated with a photosensitive resin layer after calibrating the transmittance of the transparent substrate as 100%.

In the photosensitive resin sheet of the present invention, the melt viscosity of the photosensitive resin layer at 80°C is preferably 1,500 to 50,000 Pa·s. As a result, the photosensitive resin layer can be adhered so as to cover a substrate that is flat or has irregularities due to wiring or the like, and the surface of the photosensitive resin layer after adhesion can be made flat. When the melt viscosity of the photosensitive resin layer is lower than 1,500 Pa s, the strength of the photosensitive resin layer is insufficient. The yield may deteriorate due to tearing of the film. In addition, as with varnishes and paints containing organic solvents, the amount of volatile components remaining in the photosensitive resin layer is large, so the surface of the photosensitive resin layer does not become sufficiently flat on substrates with unevenness, resulting in multi-layer coating. Defects occur in the wiring board, or the pattern line width and thickness of the metal wiring, the photosensitive resin layer, and the cured film are not as designed, resulting in a decrease in the yield of the multilayer wiring board. On the other hand, if the melt viscosity of the photosensitive resin layer is higher than 50,000 Pa·s, the adhesiveness of the photosensitive resin layer may deteriorate, resulting in poor bonding to the substrate and failure in filling the uneven portions with the resin layer. Therefore, the yield deteriorates.

[Cured film of photosensitive resin sheet]
The cured film of the present invention is a cured film formed by heating and curing the photosensitive resin layer contained in the photosensitive resin sheet of the present invention. The cured film of the present invention can be obtained by heat-curing the photosensitive resin layer of the present invention.

It is preferable that the thickness of the cured film formed by heating and curing does not change much with respect to the thickness of the photosensitive resin layer. Specifically, the curing shrinkage ratio obtained by dividing the film thickness of the photosensitive resin layer with respect to the film thickness of the cured film is preferably 80 to 105%. If the curing shrinkage is less than 80%, decomposition and/or sublimation of the photosensitive resin composition occur, resulting in deterioration of heat resistance. In addition, cracks are likely to occur in the cured film. On the other hand, if the curing shrinkage is more than 105%, the cured film contains decomposition products of the photosensitive resin layer, which may deteriorate electrical properties and reliability.

The thickness of the cured film is preferably from 12 to 40 μm, more preferably from 12 to 35 μm, even more preferably from 14 to 30 μm. When the film thickness of the cured film is 12 μm or more, insulation between metal wirings can be ensured. On the other hand, as the thickness of the cured film increases, the shrinkage stress in the curing process increases and the decomposition products contained in the cured film increase.

The glass transition temperature (Tg) of the cured film of the present invention is preferably 250°C to 350°C. More specifically, the glass transition temperature (Tg) of the cured film is preferably 250°C or higher, more preferably 280°C or higher, and even more preferably 300°C or higher. When the glass transition temperature (Tg) of the cured film is 250° C. or higher, the cured film has excellent heat resistance, and when used as a surface protective film of a semiconductor device, an interlayer insulating film, or a wiring protective insulating film of a circuit board, peeling from the wiring. and cracks can be suppressed. On the other hand, when the glass transition temperature of the cured film is higher than 350° C., fine cracks may occur in the cured film itself due to curing shrinkage in the heat curing step of obtaining the cured film from the photosensitive resin layer. The glass transition temperature (Tg) in the present invention is measured by differential scanning calorimetry (DSC method), and the temperature when the curve obtained by differentiating the heat amount change curve when measuring the cured film shows the maximum value is the glass transition temperature (Tg).

The linear expansion coefficient (α) of the cured film of the present invention is preferably 30×10 ⁻⁶ /K or more and 55×10 ⁻⁶ /K or less, more preferably 35×10 ⁻⁶ /K or more and 50×10 ^-6 /K or less. By setting the linear expansion coefficient (α) of the cured film to 55 × 10 ^-6 /K or less, when used as a surface protective film for a semiconductor device, an interlayer insulating film, or a wiring protective insulating film for a circuit board, peeling from the wiring or Cracks can be suppressed. On the other hand, if the coefficient of linear expansion (α) of the cured film is smaller than 30×10 ⁻⁶ /K, it becomes difficult to obtain a high-definition pattern. The coefficient of linear expansion (α) in the present invention was determined by thermomechanical analysis (TMA) at a heating rate of 5°C/min, and the slope from 30°C to 150°C was defined as the coefficient of linear expansion (α).

The cured film of the present invention preferably satisfies the following formula 6 and relationship C when the transmittance at 450 nm is Tc450, the transmittance at 600 nm is Tc600, and the minimum transmittance at 500 to 800 nm is TcVL.

Relationship C: Satisfies at least one of Formula 7 and Formula 8 Formula 6: 20% ≤ Tc450 ≤ 90%
Formula 7: 0.10% ≤ Tc600 ≤ 50%
Formula 8: 0.10% ≤ TcVL ≤ 50%
This will be explained in detail. In the cured film of the present invention, the cured film obtained by heat-curing the photosensitive resin layer in the photosensitive resin sheet of the present invention has a transmittance Tc450 at a wavelength of 450 nm of 20% or more and 90% or less. It is preferably 20% or more and 80% or less, and even more preferably 25% or more and 70% or less. Here, the transmittance Tc450 of the cured film at a wavelength of 450 nm is preferably 20% or more and 90% or less regardless of the film thickness. Thus, when the transmittance Tc450 of the cured film is 20% or more, a high-definition pattern can be obtained without cracks in the patterned cured film. On the other hand, when the transmittance Tc450 of the cured film is more than 90%, the coloring material is decomposed and/or sublimated, which may affect electrical properties and reliability.

In the cured film of the present invention, the cured film obtained by heat-curing the photosensitive resin layer in the photosensitive resin sheet of the present invention preferably has a transmittance Tc600 at a wavelength of 600 nm of 0.10% or more and 50% or less. , more preferably 0.10% or more and 20% or less, and more preferably 1.0% or more and 10% or less. Here, the transmittance Tc600 of the cured film at a wavelength of 600 nm is preferably 0.10% or more and 50% or less regardless of the film thickness. When the transmittance Tc600 of the cured film is less than 0.10% as described above, the content of the necessary coloring material is increased, so that the heat resistance and mechanical strength of the cured film are lowered. On the other hand, if the transmittance Tc600 is greater than 50%, the internal wiring pattern is transparent in the pattern inspection after heat curing, causing an erroneous detection. Sometimes.

The photosensitive resin layer in the photosensitive resin sheet of the present invention has a minimum value TcVL of transmittance at 500 to 800 nm of 0.10% or more and 50% or less, and 0.10% or more and 20% or less. It is preferably 1.0% or more and 10% or less. Here, it is important that the minimum transmittance TcVL be 0.10% or more and 50% or less regardless of the film thickness. If the minimum transmittance value TcVL is less than 0.1%, the content of the required coloring material increases, and the heat resistance and mechanical strength of the cured film deteriorate. On the other hand, if the minimum transmittance value TcVL is greater than 50%, the internal wiring pattern is transparent in the pattern inspection after heat curing, which may cause erroneous detection. In the pattern inspection process after heat curing, the wavelength of the inspection light used for inspection is selected to have the minimum transmittance in the range of 500 to 800 nm, thereby improving the visibility of defects and defects in the pattern. can.

The relationship between the transmittance Tb of the photosensitive resin layer and the transmittance Tc of the cured film can be expressed as Tc/Tb, and the change in film color before and after curing can be expressed. Tc450/Tb450, which is the change in film color before and after curing, is preferably 0.3 to 1.0, more preferably 0.4 to 0.8, and 0.5 to 0.8. It is even more preferable to have It is presumed that changes in film color mainly occur due to changes in transmittance due to curing reaction of the photosensitive composition and changes in transmittance due to decomposition and/or sublimation of the coloring material. When the film color change Tc450/Tb450 is 0.3 or more, the film has a high transmittance during exposure, so that a high-resolution pattern can be obtained, and inspection light in the ultraviolet region can be efficiently absorbed after the curing process. , making it easier to detect defects. On the other hand, when Tc450/Tb450 is greater than 1.0, the coloring material in the photosensitive resin composition has lost its coloring property due to decomposition and sublimation, and inspection light cannot be efficiently absorbed, and defects cannot be detected. happens. Also, the decomposition products remaining in the cured film may affect the electrical properties and reliability.

In addition, Tc600/Tb600, which is the change in film color before and after curing, is preferably 0.5 to 2.0, and more preferably Tc600/Tb600 is 0.7 to 1.5. More preferably, Tb600 is between 0.8 and 1.2. When the Tc600/Tb600 is 0.5 or more, the color variation of the cured film is small, and detection during inspection can be suppressed. On the other hand, if Tc600/Tb600 is less than 2.0, the coloring material loses its coloring property due to decomposition and sublimation, and inspection light cannot be efficiently absorbed, resulting in failure to detect defects. Alternatively, decomposition products remaining in the cured film may affect electrical properties and reliability.
TcVL/TbVL, which is the change in film color before and after curing, is preferably 0.5 to 2.0, Tc600/Tb600 is more preferably 0.7 to 1.5, and Tc600/Tb600 is More preferably 0.8 to 1.2. When the Tc600/Tb600 is 0.5 or more, the color variation of the cured film is small, and detection during inspection can be suppressed. On the other hand, if Tc600/Tb600 is less than 2.0, the coloring material loses its coloring property due to decomposition and sublimation, and inspection light cannot be efficiently absorbed, resulting in failure to detect defects. Alternatively, decomposition products remaining in the cured film may affect electrical properties and reliability.

[Processing example of photosensitive resin sheet]
Next, the method of patterning the photosensitive resin sheet of the present invention to form a permanent resist will be described with an example, but the method is not limited to this.

First, if the photosensitive resin sheet has a protective film, it is peeled off, and the photosensitive resin sheet and the substrate are arranged so as to face each other and bonded together by thermocompression bonding. Examples of the thermocompression bonding method include heat press treatment, heat lamination treatment, and thermal vacuum lamination treatment. The thermocompression bonding temperature is preferably 40° C. or higher from the viewpoint of improving the adhesion and embedding properties of the photosensitive resin layer to the substrate. On the other hand, from the viewpoint of suppressing excessive curing of the photosensitive resin layer during thermocompression bonding, the thermocompression bonding temperature is preferably 150° C. or less.

Next, after peeling off the support film on the photosensitive resin sheet formed on the substrate by the above method, the photosensitive resin layer is irradiated with actinic rays through a mask having a desired pattern, and the photosensitive resin layer is patterned. Then, an exposure step is performed. Actinic rays in the exposure step include ultraviolet rays, visible rays, electron beams, X-rays and the like. In the present invention, an ultra-high pressure mercury lamp, an ultraviolet LED lamp, a laser, etc., capable of outputting actinic rays of i-line (365 nm), h-line (405 nm), and g-line (436 nm) according to the absorption wavelength of the photopolymerization initiator. is preferably used.

In general, since the photosensitive resin layer has high sensitivity to actinic rays on the short wavelength side, i-line (365 nm), h-line (405 nm), and g-line (436 nm) output from an ultra-high pressure mercury lamp It means that it is substantially exposed to the i-line. The pattern shape can be controlled by selecting the exposure wavelength for these actinic rays with a wavelength cut filter or a bandpass filter. Specifically, h-line exposure can be performed by using an i-line cut filter for i-line (365 nm) output from an extra-high pressure mercury lamp or the like. Also, by using an h-line bandpass filter, h-line exposure that does not include i-line and g-line becomes possible. Also, by using an i-line bandpass filter, i-line exposure that does not include h-line and g-line becomes possible. Furthermore, by using a g-line bandpass filter, g-line exposure that does not include i-line and h-line becomes possible. In the photosensitive resin sheet, when the support film is made of a material transparent to these actinic rays, exposure may be performed without peeling off the support film from the photosensitive resin sheet.

It is preferable to bake the photosensitive resin layer after exposure. By performing post-exposure baking, the curing reaction proceeds satisfactorily, and effects such as an improvement in resolution after development and an increase in the allowable range of development conditions can be expected. For post-exposure baking, an oven, a hot plate, an infrared ray, a flash annealing device, a laser annealing device, or the like can be used. The post-exposure baking temperature is preferably 40 to 150°C, more preferably 60 to 120°C. The post-exposure bake time is preferably within 10 seconds to 60 minutes. When exposure is performed without removing the support film of the photosensitive resin sheet, the support film is preferably removed before baking after exposure.

After the exposure or baking of the photosensitive resin layer, a developer is used to develop the exposed portion and the unexposed portion by utilizing the difference in solubility in the developer to dissolve and remove mainly the unexposed portion to form a pattern. Form. Examples of the developing solution include alkalis such as tetramethylammonium hydroxide (TMAH) aqueous solution, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, dimethylamine, and 2-aminoethanol. Aqueous solutions of the indicated compounds are preferred. As a developing method, methods such as spray, puddle, immersion, and ultrasonic waves are possible. The developer temperature and development time are appropriately set depending on the pattern shape and the like, and are preferably 15 to 35° C. and 30 seconds to 10 minutes, respectively.

Subsequently, the pattern formed by development may be rinsed with pure water. The rinsing liquid is appropriately selected depending on the pattern residue after development. Alcohols such as ethanol and isopropyl alcohol, and esters such as ethyl lactate and propylene glycol monomethyl ether acetate are added to pure water for rinsing. may

The pattern after development is heat-treated at a temperature of 150 to 400°C to form a cured film. In this heating step (curing), a cured film with improved heat resistance and chemical resistance is obtained by polymerizing low-molecular-weight compounds such as photopolymerizable compounds and thermal cross-linking agents contained in the photosensitive resin layer. In this heat curing step, the heating temperature is preferably 150 to 400.degree. C., more preferably 200 to 300.degree. C., even more preferably 250 to 290.degree. When the heating temperature is 150° C. or higher, the polymerization reaction can proceed satisfactorily. On the other hand, by setting the heating temperature to 400° C. or lower, it is possible to suppress cracks in the cured film and breakage of the substrate due to the difference in linear expansion between the substrate and the cured film. Curing of a photosensitive resin layer using a closed-ring polyimide does not require a cyclization reaction of the polyimide precursor, so curing can be performed at a low temperature of 300° C. or less, suppressing the occurrence of cracks and reducing substrate warpage. becomes possible. The heat treatment time is preferably within 15 minutes to 6 hours. Various heating atmospheres such as air, oxygen, hydrogen, and nitrogen atmospheres can be selected, but curing in a nitrogen atmosphere is preferable from the viewpoint of heat resistance.

After exposing and developing the photosensitive resin layer, a patterned permanent resist is obtained by heat curing. It is preferable that the change rate of the film thickness of the cured film after exposure, development and heat curing is small with respect to the initial film thickness of the photosensitive resin layer. Specifically, a calculated value obtained by dividing the thickness of the cured film by the initial thickness of the photosensitive resin layer is defined as the residual film ratio of the cured film, and the residual film ratio is 70% or more. It is preferably 75% or more, more preferably 80% or more. By setting the residual film rate to 70% or more, a cured film pattern with high flatness can be obtained on a substrate having unevenness.

Although the use of the cured product is not particularly limited, for example, resists such as surface protective films built into substrates and packages that use semiconductors such as mounting substrates and wafer level packages, interlayer insulating films, wiring protective insulating films of circuit boards , various electronic components and devices. In addition, due to the excellent heat resistance of the cured film, the cured film is used as a permanent resist, that is, a patterned interlayer insulating film, a patterned substrate, glass, semiconductor element, etc., and an adherend for thermocompression bonding. It can be particularly suitably used for drug applications.

The present invention will be described below with reference to examples, etc., but the present invention is not limited to these examples.

<Alkali-soluble polyimide (A)>
An alkali-soluble polyimide synthesized by the following method was used.

Alkali-soluble polyimide A1 was synthesized by the following method.
Under a stream of dry nitrogen, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (32.78 g (0.0895 mol)) and 1,3-bis(3-aminopropyl)tetramethyldichloromethane Siloxane (1.24 g (0.005 mol)) was dissolved in N-methyl-2-pyrrolidone (100 g). Hereinafter, "N-methyl-2-pyrrolidone" is referred to as "NMP". To this solution was added bis(3,4-dicarboxyphenyl)ether dianhydride (31.02 g (0.10 mol)) along with NMP (30 g) and stirred at 20°C for 1 hour, then at 50°C. Stirred for 4 hours. 3-Aminophenol (1.09 g (0.01 mol)) was added to the stirred solution, and the mixture was stirred at 50°C for 2 hours and then stirred at 180°C for 5 hours to obtain a resin solution. The resin solution was then poured into water (3 L) to produce a white precipitate. This white precipitate was collected by filtration, washed with water three times, and then dried in a vacuum dryer at 80° C. for 5 hours. The obtained polyimide (A1) had an imidization rate of 94% and was a ring-closed polyimide. Moreover, the solubility of polyimide in a tetramethylammonium aqueous solution (2.38% by mass) at 23° C. was 0.5 g/100 g or more.

Alkali-soluble polyimide A2 was synthesized by the following method.
Under a stream of dry nitrogen, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (32.96 g, 0.09 mol) was added to 80 g of GBL and dissolved with stirring at 120°C. Then 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic dianhydride (30.03 g, 0.1 mol) It was added together with 20 g of GBL, stirred at 120° C. for 1 hour, and then stirred at 200° C. for 4 hours to obtain a resin solution. The resin solution was then poured into water (3 L) to produce a white precipitate. The precipitate was collected by filtration, washed with water three times, and dried in a vacuum dryer at 80° C. for 5 hours. The obtained polyimide (A2) had an imidization rate of 91% and was a ring-closed polyimide. Moreover, the solubility of polyimide in a tetramethylammonium aqueous solution (2.38% by mass) at 23° C. was 0.5 g/100 g or more.

<Photopolymerizable compound (B)>
B1: DPE-6A (Kyoeisha Chemical Co., Ltd.). Compound name: dipentaerythritol hexaacrylate, photopolymerizable functional group equivalent: 96, number of functional groups: 6. (BH) corresponds to the component. Corresponds to general formula (4).

B3: DCP-A (Kyoeisha Chemical Co., Ltd.). Compound name: dimethyloltricyclodecane diacrylate, photopolymerizable functional group equivalent: 152, number of functional groups: 2. It corresponds to the (BH) component. Corresponds to general formula (4).

B2: BP-6EM (Kyoeisha Chemical Co., Ltd.). Chemical name: ethylene oxide-modified bisphenol A dimethacrylate, photopolymerizable functional group equivalent: 314, number of functional groups: 2. It corresponds to the (BL) component. Not applicable to general formula (4).

B4: TEPIC-VL (Nissan Chemical Co., Ltd.). Photopolymerizable functional group equivalent: 138, number of functional groups: 3. (BL) corresponds to the component.

B5: PETG (Showa Denko KK). Photopolymerization functional group equivalent: 90, number of functional groups: 4. It corresponds to the (BH) component.

B6: BATG (Showa Denko KK). Photopolymerization functional group equivalent: 113, number of functional groups: 4. It corresponds to the (BH) component.

<Photoinitiator (C)>
“Irgacure” OXE-04 (BASF Corporation)
“ADEKA Arkles” NCI-930 (ADEKA Corporation)
CPI-310FG (San-Apro Co., Ltd.)
<Colorant (D)>
Colorant A: C.I. I. Mixed dye of solvent blue 5 and rosin-modified styrene maleate isopropyl copolymer (OilBlue613, Orient Chemical Industry Co., Ltd., triarylmethane dye)
Colorant B: C.I. I. Solvent Blue 44 (phthalocyanine dye)
Colorant C: C.I. I. Solvent Blue 45 (anthraquinone dye)
Colorant D: C.I. I. Basic Violet 3 (triarylmethane dye)
Colorant E: Oil Red O (Fuji Film Co., Ltd., azo dye)
<Inorganic particles>
Inorganic particles A: SE2050-YNB (Admatechs Co., Ltd.) silica, average particle size: 500 nm (solid content 70% by weight / ethyl lactate dispersion)
Inorganic particles B: Y50SZ-AY1 (Admatechs Co., Ltd.) average particle size: 50 nm, silica (solid content 40% by weight / ethyl lactate dispersion)
Inorganic particles C: Y100SZ-AY1 (Admatechs Co., Ltd.) average particle size: 100 nm, silica (solid content 40% by weight / ethyl lactate dispersion)
Inorganic Particles D: “Optolake” (registered trademark) TR-527 (Catalysts & Chemicals Co., Ltd.) silica/titania composite particles, average particle size: 15 nm, (solid content 20% by weight/PGMEA dispersion)
<Thermal cross-linking material>
HMOM-TPHAP (Honshu Chemical Industry Co., Ltd.)
<Polymerization inhibitor>
Phenothiazine (Tokyo Chemical Industry Co., Ltd.)
Kino Power QS-30 (Kawasaki Kasei Co., Ltd.)
<Adhesion improver>
KBM-403 (Shin-Etsu Chemical Co., Ltd.)
CBT-1 (Johoku Chemical Industry Co., Ltd.)
<Sensitizer>
UVS-1331 (Kawasaki Kasei Co., Ltd.)
<Evaluation of glass transition temperature and linear expansion coefficient of cured film>
The protective film of the photosensitive resin sheet obtained in each example and each comparative example was peeled off, arranged so that the layer made of the photosensitive resin composition faced the silicon wafer, and heated at 80 ° C. and 0.3 MPa for 4 times. It was roll laminated onto an inch silicon wafer.

After peeling off the support film of the obtained photosensitive resin sheet, the photosensitive resin sheet was exposed at an exposure amount of 1000 mJ/cm ² (using an i-line cut filter, converted to h-line) using an exposure machine using an ultra-high pressure mercury lamp as a light source. Heat treatment was performed at 290° C. for 60 minutes in an inert oven in a nitrogen atmosphere to form a cured film on the silicon wafer. The obtained cured film was separated from the silicon wafer to prepare a single film.

A sample for measuring the glass transition temperature was obtained by cutting this single film into 5 mm × 50 mm pieces with a single edge, and using a viscoelasticity measuring device (DMS6100 manufactured by Seiko Instruments Inc.) to raise the temperature from 25 ° C. to 450 ° C. at a rate of 5 ° C./min. was measured at the temperature at which the curve obtained by differentiating was the maximum value. The amplitude width was 5 μm, the minimum tension was 10 mN, and the initial force amplitude was 50 mN.
A sample for measuring the coefficient of linear expansion was cut from this single film into 5 mm × 20 mm pieces with a single blade, and the temperature was raised/lowered from 25°C to 150°C at 5 minutes/min with a thermomechanical analyzer (manufactured by Shimadzu Corporation, TMA-60). The coefficient of linear expansion at the time of repeating the temperature rise for the second time was used as the evaluation result.

<Evaluation of Melt Viscosity of Photosensitive Resin Layer>
The protective film is peeled off from the photosensitive resin sheet, and the photosensitive resin layers are laminated together by a roll laminator heated to 80°C. The support film on one side of the laminate is peeled off, and the photosensitive resin layers are bonded together again. This is repeated to obtain a photosensitive resin layer laminate having a thickness of 400 to 800 μm. The support films on both sides of this laminate were peeled off, and the composite viscosity at 80° C. was measured by sandwiching it between probes of a viscoelasticity measuring device with a diameter of 15 mm and measuring the temperature in the range of 40° C. to 100° C. at a heating rate of 2° C./min. melt viscosity.

<Pattern workability evaluation (resolution/pattern cross-sectional shape)>
The protective film of the photosensitive resin sheet obtained in Example 1 was peeled off, the photosensitive resin sheet was placed facing the silicon wafer, and a 4-inch silicon wafer and copper wiring were placed under conditions of 80° C. and 0.3 MPa. (100 μm width, 5 μm height) was roll-laminated on a silicon wafer.

After peeling off the support film of the photosensitive resin sheet composed of the obtained support film and the photosensitive resin layer, vias in which 20 via patterns with via diameters of 5, 10, 15, and up to 100 μm in increments of 5 μm were arranged. A photomask having a formation area and a stripe pattern formation area in which 20 rows of stripe patterns in which lines and spaces are arranged at equal intervals with a pitch of 100 μm is placed, and an exposure amount is obtained with an exposure machine using an ultra-high pressure mercury lamp as a light source. Exposure was performed at 1000 mJ/cm ² (using an i-line cut filter, converted to h-line). After exposure, it was heated on a hot plate at 100° C. for 5 minutes. Next, using a 2.38% by weight aqueous solution of tetramethylammonium hydroxide, the unexposed portion was removed by shower development for 180 seconds, rinsed with water for 60 seconds, and then spin-dried. Further, heat treatment was performed at 290° C. for 60 minutes in an inert oven to form a cured film pattern in which a via pattern and a stripe pattern were processed on the silicon wafer.

The via pattern was observed with a microscope, and the minimum dimension at which the via was opened was defined as the resolution. The opening of the via as referred to herein is defined as opening at 50% or more of the design value of the photomask. Pattern resolution A is for vias with a via opening of 30 μm or less, pattern resolution B is for vias with a via opening of 35 μm to 50 μm, and pattern resolution C is for vias with a via opening of 55 μm to 100 μm. Judged.

In addition, after cutting perpendicular to the stripe pattern, the cross section of the pattern is observed with an optical microscope. The width of the grounded pattern on the silicon wafer was measured as the bottom width, and the width of the pattern surface side facing the silicon wafer was measured as the top width. As the absolute value ΔW of the difference between the top width and the bottom width, pattern cross-sectional shape A has a ΔW of less than 5 μm, pattern cross-sectional shape B has a ΔW of 5 to 10 μm, and pattern cross-sectional shape C has a ΔW greater than 10 μm. I judged.

<Evaluation of transmittance of photosensitive resin layer and cured film>
The photosensitive resin sheet from which the protective film was removed from the photosensitive resin sheet obtained in each example and each comparative example was roll-laminated on a soda glass substrate (thickness of 1.1 mm) at 80° C. and 0.3 MPa. A transmittance measurement sample of the photosensitive resin layer was prepared by peeling off the support film. The transmittance of this sample at a wavelength of 350 to 800 nm was measured three times using an ultraviolet-visible spectrophotometer (manufactured by Hitachi High-Tech Science Co., Ltd., U-3900). The average transmittance at 450 nm and 600 nm was used as the evaluation result. The minimum value of the transmittance at wavelengths of 500 to 800 nm was measured three times, and the average value of the transmittances at the minimum wavelengths in those wavelength regions was used as the evaluation result. The transmittance measurement of the photosensitive resin layer was performed under the conditions of reference: soda glass substrate, scan speed: 300 nm/min, and sampling interval: 0.5 nm.

The cured film transmittance measurement sample was exposed to an exposure amount of 1000 mJ/cm ² (using an i-line cut filter, converted to h-line) with an exposure machine using an ultra-high pressure mercury lamp as a light source for the sample for measuring the photosensitive resin layer. Then, heat treatment was performed in an inert oven at 290° C. for 60 minutes in a nitrogen atmosphere to form a cured film on a glass substrate.

<Determination of Coating Inspectability>
A silicon wafer having a film of a photosensitive resin layer formed thereon was washed with ultrapure water, and then foreign matters were adhered thereto. Observe the surface of the coating film with an optical microscope with a 10x lens and focus on the surface of the coating film on which the foreign matter has adhered. B, and if no foreign matter could be detected, the surface inspectability was rated as C.

In addition, a film of a photosensitive resin layer was formed on a substrate having copper wiring (width 100 μm/thickness 5 μm). Focusing on this film surface, defect detectability A if the contour of the embedded copper wiring cannot be detected, defect detectability B if the contour is unclear, and defect detectability if the contour of the copper wiring is clear. C. If the contour of the copper wiring is clear, the coating film surface may be erroneously detected in the automatic defect inspection, or interference of the inspection light may cause erroneous detection.

Both surface inspectability and defect detectability are preferably A or B.

<Example 1>
A method for preparing the photosensitive resin composition of Example 1 is shown below as an example.

Alkali-soluble polyimide (A1, 35 g), DPE-6A (B1, 2 g) as a photopolymerizable compound, BP-6EM (B2, 18 g), NCI-930 (3 g) as a photopolymerization initiator (C), coloring agent (D) as coloring material D1 (0.64 g), HMOM-TPHAP γ-butyrolactone solution (30 g (6 g as solid content)) as thermal cross-linking agent, QS-30 (0.01 g) as polymerization inhibitor, adhesion improvement KBM-403 (2 g) as an agent and ethyl lactate (52 g) as a diluting solvent were added and stirred at room temperature for 120 minutes. A paint 1 of a flexible resin composition was obtained.

The obtained paint 1 of the photosensitive resin composition was applied onto a support film (PET film Lumirror S10 with a thickness of 38 μm) using a comma roll coater, dried at 85° C. for 5 minutes, and then applied to the protective film. A PP film (Toretec 7332K) having a thickness of 30 μm was laminated as a photosensitive resin sheet having a photosensitive resin layer having a thickness of 26 μm. The obtained photosensitive resin sheet was evaluated by the method described above, and the evaluation results of Example 1 are shown in Table 1.

As described above, the pattern processability was evaluated, and both the support film and the protective film of the photosensitive resin sheet could be peeled off from the photosensitive resin layer satisfactorily. Using a predetermined photomask, exposure was performed at the exposure wavelength and exposure amount shown in Table 1 to form a cured film pattern, and the pattern resolution and pattern cross-sectional shape were evaluated and judged. The pattern resolution was A and the pattern cross-sectional shape was A, which were good results.

In addition, the transmittance of the photosensitive resin layer and the cured film was evaluated. For the photosensitive resin layer, transmittance Tb405 at 405 nm, which is the exposure wavelength, transmittance Tb450 at 450 nm, and Tb600 or TbVL, which is the minimum value of transmittance at a wavelength of 500 to 800 nm, are calculated. Tc600 or TcVL, which is the minimum value of transmittance at 500 to 800 nm, was calculated.

As described above, the inspectability of the coating film was evaluated, and foreign matter on the surface of the coating film could be clearly observed, and the outline of the copper wiring was clear.

<Examples 2 to 23, Comparative Examples 1 to 3>
In Examples 2 to 23 of the present invention and Comparative Examples 1 to 3 for the present invention, the composition and film thickness of the photosensitive resin composition in Example 1 described above, and the pattern processing conditions for evaluating pattern processability are shown in Tables 1 to 3. A photosensitive resin sheet was produced in the same manner as in Example 1 except that the composition and film thickness were changed as shown in . Using the obtained photosensitive resin sheet, evaluation was performed in the same manner as in Example 1 except that the patterning conditions shown in Tables 1 to 3 were changed in the above-described method, Examples 2 to 23, and Comparative Examples. The evaluation results of 1 to 3 are shown in Tables 1 to 3.

<Examples 24 to 27>
In Examples 24 to 27 of the present invention, the support film in Example 1 described above was changed to a PET film (Cosmoshine A4160) having a thickness of 50 μm, and the composition and film thickness of the photosensitive resin composition and pattern processability were evaluated. A photosensitive resin sheet was produced in the same manner as in Example 1, except that the patterning conditions were changed to the composition and film thickness shown in Table 3. Using the obtained photosensitive resin sheet, evaluation was performed in the same manner as in Example 1, except that the patterning conditions were changed to those shown in Table 3 in the above-described method. An i-line bandpass filter was used with an exposure machine using an ultra-high pressure mercury lamp as a light source, and a predetermined amount of exposure was converted to i-line and exposed. Both the support film and the protective film can be peeled off from the photosensitive resin layer satisfactorily.

In the table, the numerical value in the "composition" column means mass (g).

As shown in Tables 1 to 3, the photosensitive resin sheet having a photosensitive resin layer with high transmittance in the ultraviolet region has a rectangular cross-sectional shape of the pattern, can form a fine pattern, and can be used in the visible light region. By lowering the transmittance, excellent results were obtained for surface inspection and defect detection.

The photosensitive resin sheet having the photosensitive resin of the present invention has high electrical properties derived from polyimide, excellent mechanical properties and heat resistance, and has high reliability. Due to its excellent detectability, it is useful for multilayer wiring substrate applications such as surface protective films and interlayer insulating films for semiconductor devices and electronic parts, and wiring protective insulating films for circuit boards.

1: Substrate 2: Photosensitive resin layer 3: Foreign matter adhering to the surface 4: Foreign matter contained between the photosensitive resin layer and substrate 5: Metal wiring layer 6: Peeling portion of photosensitive resin layer 7: Top width of pattern 8: Pattern bottom width of

Claims

A photosensitive resin sheet having a support film and a photosensitive resin layer,
The photosensitive resin layer is a layer formed from a photosensitive resin composition,
The photosensitive resin composition is a resin composition containing an alkali-soluble polyimide (A), a photopolymerizable compound (B), a photopolymerization initiator (C), and a coloring agent (D),
A photosensitive resin sheet characterized in that the photosensitive resin layer satisfies the following relationship A when the transmittance at 600 nm is Tb600 and the minimum transmittance at 500 to 800 nm is TbVL.
Relationship A: Formula 1 that satisfies at least one of formulas 1 and 2: 0.10% ≤ Tb600 ≤ 40%
Formula 2: 0.10% ≤ TbVL ≤ 40%
2. The photosensitive resin according to claim 1, wherein the photosensitive resin layer satisfies the following relationship B when the transmittance at 365 nm is Tb365, the transmittance at 405 nm is Tb405, and the transmittance at 436 nm is Tb436. sheet.
Relationship B: Formula 3 that satisfies at least one of formulas 3 to 5: 3.0% ≤ Tb365 ≤ 70%
Formula 4: 3.0% ≤ Tb405 ≤ 70%
Formula 5: 3.0% ≤ Tb436 ≤ 70%
The photosensitive resin sheet according to claim 1 or 2, wherein the alkali-soluble polyimide (A) is a ring-closed polyimide.
The photosensitive resin sheet according to claim 1 or 2, further comprising a protective film, wherein the support film, the photosensitive resin layer, and the protective film are directly laminated in this order.
3. The photosensitive resin sheet according to claim 1, wherein the photosensitive resin layer has a transmittance Tb450 at 450 nm that satisfies the following relationship.
40%≤Tb450≤95%
The content of the coloring material (D) is 0.1 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the alkali-soluble polyimide (A), either of claim 1 or 2 The photosensitive resin sheet according to .
The photosensitive resin sheet according to claim 1 or 2, wherein the coloring material (D) contains an anthraquinone compound.
The photosensitive resin sheet according to claim 1 or 2, wherein the photosensitive resin composition contains inorganic particles.
The photosensitive resin sheet according to claim 8, wherein the inorganic particles have an average particle diameter D50 of 30 to 150 nm.
The photosensitive resin sheet according to claim 1 or 2, wherein the thickness of the photosensitive resin layer is 15 to 40 µm.
The photosensitive resin sheet according to claim 1 or 2, wherein the photosensitive resin composition has a melt viscosity of 1500 to 50000 Pa·s at 80°C.
A cured film formed by heating and curing the photosensitive resin layer of the photosensitive resin sheet according to claim 1 or 2.
The curing according to claim 12, wherein the following formula 6 and relationship C are satisfied when the transmittance Tc450 at 450 nm, the transmittance Tc600 at 600 nm, and the minimum transmittance TcVL at 500 to 800 nm are satisfied. film.
Formula 6: 20% ≤ Tc450 ≤ 90%
Relationship C: satisfying at least one of formulas 7 and 8 Formula 7: 0.10% ≤ Tc600 ≤ 50%
Formula 8: 0.10% ≤ TcVL ≤ 50%
13. The cured film according to claim 12, wherein the coefficient of linear expansion (α) is 30×10 −6 /K or more and 55×10 −6 /K or less.
The cured film according to claim 12, which has a glass transition temperature of 250°C to 350°C.
A multilayer wiring board having the cured film according to claim 12.