JP7440224B2 - Positive photosensitive resin composition - Google Patents

Description

The present invention relates to a positive photosensitive resin composition, a dry film, a cured product, and electronic components such as printed wiring boards and semiconductor devices.

It is known to use a positive photosensitive resin composition that can be developed with an alkaline aqueous solution to form surface protective films, interlayer insulating films, etc. in electronic components. Such a composition is a composition in which a polybenzoxazole (hereinafter also referred to as "PBO") precursor that provides a cured product with excellent heat resistance and electrical insulation is combined with a photoacid generator such as a naphthoquinone diazide compound. is attracting attention.

A positive photosensitive resin composition is required to have patternability as well as adhesion to silicon wafers, substrates, etc. In order to meet such demands, research and development of photosensitive resin compositions has been carried out.

Patent Document 1 proposes a positive photosensitive resin composition that has excellent adhesion and a residual film rate in unexposed areas by combining a melamine crosslinking agent and a specific silane coupling agent.
Patent Document 2 proposes a positive photosensitive resin composition that is excellent in both adhesion and developability by blending a specific azole compound.
Patent Document 3 proposes a positive photosensitive resin composition containing a compound that is liquid under 1013 hPa and 25°C and has a boiling point of 210°C or higher in order to improve adhesion to copper. .

International Publication 2018/056013 JP 2019-20522 Publication International Publication 2017/217293

However, in the positive photosensitive resin compositions described in these patent documents, the flexibility (elongation) of the cured product made of the positive photosensitive resin composition is not sufficient. When an insulating film is formed on a silicon wafer using this method, there is a problem in that the insulating film cracks or peels due to distortion (warpage) that occurs between the silicon wafer and the insulating film. Therefore, such insulating films are required to have good flexibility (elongation) that can withstand strain (warpage).

Therefore, an object of the present invention is to provide a positive photosensitive resin composition that can provide a cured product with excellent adhesion and patterning properties and good flexibility (elongation).

The present inventors have applied adhesive properties of a positive photosensitive resin composition containing a polybenzoxazole precursor and a photoacid generator to a silane coupling agent containing a nitrogen atom with an amine value of 20 mgKOH/g or more and 100 mgKOH/g or less. The inventors have discovered that the above-mentioned problems can be solved by combining it with an improving agent, and have completed the present invention.

The gist of the present invention is as follows.
[1] (A) polybenzoxazole precursor,
(B) photoacid generator,
A positive photosensitive resin composition comprising (C) a silane coupling agent containing a nitrogen atom and (D) an adhesion improver having an amine value of 20 mgKOH/g or more and 100 mgKOH/g or less.
[2] The positive photosensitive resin composition of [1] further comprising (E) a crosslinking agent.
[3] For 100 parts by mass of (A),
(B) is 0.5 parts by mass or more and 40 parts by mass or less,
The positive photosensitive resin composition according to [1] or [2], wherein (C) is 0.1 parts by mass or more and 10 parts by mass or less, and (D) is 0.1 parts by mass or more and 10 parts by mass or less.
[4] Any one of [1] to [3], wherein the mass ratio of (C) and (D) (mass of (C): mass of (D)) is 1:0.2 to 1:10. positive photosensitive resin composition.
[5] The positive photosensitive resin composition according to any one of [1] to [4], wherein (C) is an amino group-containing alkoxysilane.
[6] A dry film having a resin layer obtained by applying and drying the positive photosensitive resin composition according to any one of [1] to [5].
[7] A cured product obtained by curing the positive photosensitive resin composition according to any one of [1] to [5] or the resin layer of the dry film according to [6].
[8] An electronic component comprising the cured product of [7].
[9] A method for producing a positive photosensitive resin composition according to any one of [1] to [5], which comprises adding (C) while stirring (A) and (B) in a solvent; Then (D) is added, or (D) is added and then (C) is added.

According to the present invention, a positive photosensitive resin composition is provided which can provide a cured product having excellent adhesion and patterning properties and good flexibility (elongation). In addition, a dry film having a resin layer obtained from the composition, a cured product obtained by curing the resin layer of the composition or the dry film, and electronic components such as printed wiring boards and semiconductor elements containing the cured product are also available. provided.

<Positive photosensitive resin composition>
The positive photosensitive resin composition of the present invention comprises (A) a polybenzoxazole precursor, (B) a photoacid generator, (C) a silane coupling agent containing a nitrogen atom, and (D) an amine value of 20 mgKOH/g or more. Contains an adhesion improver of 100 mg KOH/g or less.

（式中、
Ｘは、４価の有機基であり、
Ｙは、２価の有機基であり、
ｎは、１以上の整数であり、好ましくは１０以上５０以下の整数であり、より好ましくは２０以上４０以下の整数である。）
で示される繰り返し構造を有するポリヒドロキシアミド酸が好ましい。４価の有機基であるＸは、隣接するアミド結合（－ＮＨＣＯ－）と閉環反応によってベンゾオキサゾール骨格を形成可能な基であることができる。 (A) Polybenzoxazole Precursor The polybenzoxazole precursor is not particularly limited as long as it is a resin that forms a benzoxazole skeleton through a ring-closing reaction. Formula (1):

(In the formula,
X is a tetravalent organic group,
Y is a divalent organic group,
n is an integer of 1 or more, preferably an integer of 10 or more and 50 or less, more preferably an integer of 20 or more and 40 or less. )
A polyhydroxyamic acid having a repeating structure shown in is preferred. X, which is a tetravalent organic group, can be a group capable of forming a benzoxazole skeleton through a ring-closing reaction with an adjacent amide bond (-NHCO-).

Such a polyhydroxyamic acid can be obtained by reacting dihydroxydiamines as the amine component and dicarboxylic acid dihalides such as dicarboxylic acid dichloride as the acid component. In place of dicarboxylic acid dihalides, active ester dicarboxylic acids, tetracarboxylic dianhydrides, trimellitic anhydrides, etc. can also be used.

Examples of dihydroxydiamines include 3,3'-diamino-4,4'-dihydroxybiphenyl, 4,4'-diamino-3,3'-dihydroxybiphenyl, bis(3-amino-4-hydroxyphenyl)propane, and bis(3-amino-4-hydroxyphenyl)propane. (4-amino-3-hydroxyphenyl)propane, bis(3-amino-4-hydroxyphenyl)sulfone, bis(4-amino-3-hydroxyphenyl)sulfone, 2,2-bis(3-amino-4- hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-bis(4-amino-3-hydroxyphenyl)-1,1,1,3,3,3-hexafluoro Examples include propane. Among them, 2,2-bis(3-amino-4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane is preferred.

Examples of dicarboxylic acids in dicarboxylic acid dihalides include isophthalic acid, terephthalic acid, 5-tert-butyl isophthalic acid, 5-bromoisophthalic acid, 5-fluoroisophthalic acid, 5-chloroisophthalic acid, 2,6-naphthalene dicarboxylic acid, 4,4'-dicarboxybiphenyl, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxytetraphenylsilane, bis(4-carboxyphenyl)sulfone, 2,2-bis(p-carboxyphenyl)propane , dicarboxylic acids with aromatic rings such as 2,2-bis(4-carboxyphenyl)-1,1,1,3,3,3-hexafluoropropane, oxalic acid, malonic acid, succinic acid, 1,2- Examples include aliphatic dicarboxylic acids such as cyclobutanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and 1,3-cyclopentanedicarboxylic acid. Among them, 4,4'-dicarboxydiphenyl ether is preferred.

In formula (1), the tetravalent organic group represented by Corresponds to the structure excluding . -OH adjacent to X and the nitrogen atom of the amide bond (-NHCO-) can be bonded to be located at the ortho position of the benzene ring contained in X. The number of carbon atoms in the tetravalent aromatic group is preferably 6 or more and 30 or less, more preferably 6 or more and 24 or less. The aromatic group may contain an oxygen atom, a sulfur atom, or a halogen atom (fluorine atom, chlorine atom, etc.).

Examples of X include, but are not limited to, the following groups, and may be any known aromatic group contained in a polybenzoxazole precursor.

Among them, the following groups are preferred.

In formula (1), the divalent organic group represented by Y can be a divalent aliphatic group or an aromatic group corresponding to the dicarboxylic acid, and has a structure obtained by removing two carboxyl groups from the dicarboxylic acid. Equivalent to. Y is preferably an aromatic group, and more preferably the carbon atom of the amide bond (-NHCO-) adjacent to Y is bonded to the benzene ring in Y. The number of carbon atoms in the divalent aromatic group is preferably 6 or more and 30 or less, more preferably 6 or more and 24 or less. The aromatic group may contain an oxygen atom, a sulfur atom, or a halogen atom (fluorine atom, chlorine atom, etc.).

（式中、
Ａは、単結合、－ＣＨ_２－、－Ｏ－、－ＣＯ－、－Ｓ－、－ＳＯ_２－、－ＮＨＣＯ－、－Ｃ（ＣＦ_３）_２－又は－Ｃ（ＣＨ_３）_２－を示す。） Examples of Y include the following groups, but are not limited to these, and may be any known aromatic group contained in a polybenzoxazole precursor.

(In the formula,
A represents a single bond, -CH ₂ -, -O-, -CO-, -S-, -SO ₂ -, -NHCO-, -C(CF ₃ ) ₂ - or -C(CH ₃ ) ₂ - show. )

Among them, the following groups are preferable for Y.

The polybenzoxazole precursor may contain only one type of repeating structure represented by formula (1), or may contain two or more types. Further, it may contain a structure other than the repeating structure represented by formula (1), and such a structure includes, for example, a repeating structure of polyamic acid.

The number average molecular weight (Mn) of the polybenzoxazole precursor is preferably 5,000 or more, more preferably 8,000 or more, and preferably 100,000 or less, more preferably 50,000 or less . In this specification, the number average molecular weight is a value measured by (GPC) and converted to standard polystyrene.
The weight average molecular weight (Mw) of the polybenzoxazole precursor is preferably 10,000 or more, more preferably 16,000 or more, and preferably 200,000 or less , more preferably 100,000 or less . In this specification, the weight average molecular weight is a value measured by (GPC) and converted to standard polystyrene.
Mw/Mn is preferably 1 or more, preferably 5 or less, and more preferably 3 or less.

The polybenzoxazole precursors may be used alone or in combination of two or more.

(B) Photoacid generator The photoacid generator is not particularly limited as long as it is a compound that generates acid by absorbing light energy. For example, naphthoquinonediazide compounds, diarylsulfonium salts, triarylsulfonium salts, dialkylphenacylsulfonium salts, diaryliodonium salts, aryldiazonium salts, aromatic tetracarboxylic acid esters, aromatic sulfonic acid esters, nitrobenzyl esters, aromatic N- Examples include oximide sulfonate, aromatic sulfamide, benzoquinone diazosulfonic acid ester, and the like.

Preferably, the photoacid generator is a dissolution inhibitor. Among these, naphthoquinone diazide compounds are preferred. Examples of naphthoquinone diazide compounds include naphthoquinone diazide adducts of tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene (for example, TS533, TS567, TS583, and TS593 manufactured by Sanpo Chemical Research Institute), and tetra Examples include naphthoquinonediazide adducts of hydroxybenzophenone (for example, BS550, BS570, BS599 manufactured by Sanpo Chemical Research Institute).

The photoacid generators may be used alone or in combination of two or more.

(C) Silane coupling agent containing a nitrogen atom Examples of the silane coupling agent containing a nitrogen atom include amino group-containing alkoxysilane, urea group-containing alkoxysilane, ureido group-containing alkoxysilane, isocyanate group-containing alkoxysilane, and isocyanurate group-containing alkoxysilane. Examples include alkoxysilane.

The amino group in the amino group-containing alkoxysilane is unsubstituted or substituted, and examples of substitution include mono- or di-substituted amino groups with alkyl groups, aryl groups, heteroaryl groups, etc. The alkyl group, aryl group, heteroaryl group, etc. may be substituted with a hydroxy group or the like, or may be substituted with an amino group.

Examples of the alkyl group include alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, propyl, etc., with propyl being preferred.
Examples of the aryl group include aryl groups having 6 to 15 carbon atoms, such as phenyl, tolyl, xylyl, naphthyl, anthracenyl, and phenanthrenyl, with phenyl being preferred.
Examples of the heteroatom in the heteroaryl group include a nitrogen atom, a sulfur atom, an oxygen atom, and the like. Examples of the heteroaryl group include thienyl, indolyl, furanyl, oxiranyl, and the like, with thienyl being preferred.

（式中、
Ｒ^３１～Ｒ^３５は、独立して、水素原子又は有機基（例えば、炭素原子数１以上６以下のアルキル基、炭素原子数６以上１５以下のアリール基等）であり、好ましくは水素原子である。）で示される基が挙げられる。 As the amino group substituted with an aryl group, for example, formula (2):

(In the formula,
R ³¹ to R ³⁵ are independently a hydrogen atom or an organic group (for example, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 15 carbon atoms, etc.), and preferably a hydrogen atom. be. ) are mentioned.

The amino group-containing alkoxysilane may have two or more amino groups, and in that case, the two or more amino groups may be the same or different.

The silyl group in the amino group-containing alkoxysilane includes a dialkoxyalkylsilyl group, a trialkoxysilyl group, and the like, with a trialkoxysilyl group being preferred. Examples of the alkoxy group include methoxy, ethoxy, propoxy, butoxy and the like, with methoxy and ethoxy being preferred. When the silyl group has multiple alkoxy groups, they may be the same or different, preferably the same.

The amino group-containing alkoxysilane may have two or more silyl groups, and in that case, the two silyl groups may be the same or different. The number of silyl groups in the amino group-containing alkoxysilane is preferably one.

The amino group-containing alkoxysilane is preferably an amino group-containing alkoxysilane in which the nitrogen atom of the amino group and the silicon atom of the silyl group are bonded via a hydrocarbon group having 1 or more and 10 or less carbon atoms. The number of carbon atoms in the hydrocarbon group is preferably 1 or more and 6 or less. Examples of the hydrocarbon group include alkylene groups, and linear alkylene groups are preferred.

Examples of the amino group-containing alkoxysilane include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl)- 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, N-(2-aminoethyl) -3-aminopropylmethyldiethoxysilane, bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl- Examples include 3-amino-propyltrimethoxysilane.

Examples of the urea group-containing alkoxysilane include N,N-bis(3-trimethoxysilylpropyl)urea and N,N-bis(3-triethoxysilylpropyl)urea.

Examples of the ureido group-containing alkoxysilane include 3-ureidopropyltriethoxysilane.

Examples of the isocyanate group-containing alkoxysilane include 3-isocyanatepropyltriethoxysilane.

Examples of the isocyanurate group-containing alkoxysilane include tris-(trimethoxysilylpropyl)isocyanurate.

From the viewpoint of both adhesion and patterning properties, amino group-containing alkoxysilanes are preferred, and among them, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-amino-propyltrimethoxysilane, etc. is preferred.

The silane coupling agents containing a nitrogen atom may be used alone or in combination of two or more.

(D) Adhesion improver having an amine value of 20 mgKOH/g or more and 100 mgKOH/g or less The adhesion improver has an amine value of 20 mgKOH/g or more and 100 mgKOH/g or less. From the viewpoint of adhesion to metals and improvement of cured film properties, the amine value is preferably 30 mgKOH/g or more, and preferably 70 mgKOH/g or less.

The adhesion improver is preferably a polymeric adhesion improver, and from the viewpoint of improving the physical properties of the cured film, the number average molecular weight (Mn) is preferably 200 or more, more preferably 1,000 or more, and , 50,000 or less is preferable, and 20,000 or less is more preferable.

The adhesion improver can contain a hydroxyl group.

Examples of the adhesion improver include BYK-4512 (CAS No. 1788896-49-0) and BYK-4513 (CAS No. 2255 3 43-54-3) manufactured by BYK Chemie Japan.

The adhesion improvers having an amine value of 20 mgKOH/g or more and 100 mgKOH/g or less may be used alone or in combination of two or more.

The positive photosensitive resin composition of the present invention can contain (B) a photoacid generator in an amount of 1 part by mass or more and 40 parts by mass or less with respect to 100 parts by mass of (A) polybenzoxazole precursor. From the viewpoint of improving patterning properties, it is preferably 7 parts by mass or more, and from the viewpoint of suppressing a decrease in sensitivity, it is preferably 20 parts by mass or less.

The positive photosensitive resin composition of the present invention contains (C) a nitrogen atom-containing silane coupling agent in an amount of 0.1 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of (A) a polybenzoxazole precursor. be able to. From the viewpoint of imparting adhesion to the substrate, it is preferably 0.5 parts by mass or more, and from the viewpoint of preventing development residues, it is preferably 10 parts by mass or less.

In the positive photosensitive resin composition of the present invention, 0.1 mass parts of (D) an adhesion improver having an amine value of 20 mgKOH/g or more and 100 mgKOH/g or less is added to 100 parts by mass of (A) the polybenzoxazole precursor. It can be included in an amount of 1 part or more and 10 parts by mass or less. From the viewpoint of providing adhesion and improving the physical properties of the film, it is preferably 3 parts by mass or more, and from the viewpoint of suppressing deterioration of thermal properties, it is preferably 7 parts by mass or less.

The mass proportion of (C) the silane coupling agent containing a nitrogen atom and (D) the adhesion improver having an amine value of 20 mgKOH/g or more and 100 mgKOH/g or less is determined from the viewpoint of achieving both adhesion to the silicon substrate and metal. The mass of (C): the mass of (D) is preferably 1:0.2 to 1:10, more preferably 1:0.5 to 1:6.

(E) Crosslinking agent The positive photosensitive resin composition of the present invention may contain a crosslinking agent. A crosslinking agent is an agent that can be crosslinked or polymerized by heating. The crosslinking agent reacts with the polybenzoxazole precursor or polybenzoxazole in the heat treatment process after coating, exposure, and development to crosslink, or the crosslinking agent itself polymerizes, reducing the residual film rate in the unexposed area. At the same time, it is possible to prevent undeveloped areas in exposed areas and improve patterning properties.

The crosslinking agent is preferably a compound having a methylol group, an alkoxymethyl group, an epoxy group, an oxetanyl group, or a vinyl ether group, a compound in which these groups are bonded to a benzene ring, and a compound in which the N-position is selected from a methylol group and an alkoxymethyl group. More preferred are melamine resins or urea resins substituted with groups.

Examples of the crosslinking agent include the following.

From the viewpoint of improving patterning properties and chemical resistance, a crosslinking agent having a melamine structure is preferred.

The crosslinking agents may be used alone or in combination of two or more.

When using a crosslinking agent, the crosslinking agent is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and preferably 50 parts by mass or less, based on 100 parts by mass of the polybenzoxazole precursor (A). More preferably, it is 20 parts by mass or less.

(F) Solvent The positive photosensitive resin composition of the present invention may contain a solvent. The solvent includes (A) a polybenzoxazole precursor, (B) a photoacid generator, (C) a silane coupling agent containing a nitrogen atom, and (D) an adhesion improving agent with an amine value of 20 mgKOH/g or more and 100 mgKOH/g or less. There is no particular limitation as long as it dissolves the agent and any optional ingredients that may be added.

For example, N,N'-dimethylformamide, N-methylpyrrolidone, N-ethyl-2-pyrrolidone, N,N'-dimethylacetamide, diethylene glycol dimethyl ether, cyclopentanone, γ-butyrolactone, α-acetyl-γ-butyrolactone, Examples include tetramethylurea, 1,3-dimethyl-2-imidazolinone, N-cyclohexyl-2-pyrrolidone, dimethyl sulfoxide, hexamethylphosphoramide, pyridine, diethylene glycol monomethyl ether, and the like. From the viewpoint of solubility and workability, γ-butyrolactone is preferred.

One type of solvent may be used alone or two or more types may be used in combination.

When using a solvent, the amount of the solvent can be selected depending on the coating thickness, viscosity, etc., but it is preferably 50 parts by mass or more, and 150 parts by mass or more based on 100 parts by mass of (A) polybenzoxazole precursor. The amount is more preferably 9,000 parts by mass or less, and more preferably 700 parts by mass or less.

The positive photosensitive resin composition of the present invention may contain components other than those mentioned above, as long as the effects of the present invention are not impaired. For example, it can contain t-butylcatechol, thereby reducing development residue (scum). In addition, silane coupling agents other than (C), adhesion improvers other than (D), surfactants, leveling agents, plasticizers, fine particles (organic fine particles such as polystyrene and polytetrafluoroethylene, colloidal silica, carbon, (inorganic fine particles such as layered silicate), colorants, fibers, etc.

<Method for producing positive photosensitive resin composition>
The positive photosensitive resin composition of the present invention comprises (A) a polybenzoxazole precursor, (B) a photoacid generator, (C) a silane coupling agent containing a nitrogen atom, and (D) an amine value of 20 mgKOH/g or more. It can be produced by mixing an adhesion improver with a concentration of 100 mgKOH/g or less, and optionally (E) a crosslinking agent, (F) a solvent, and other optional components, but if (C) and (D) are directly If they come into contact with each other, gelation may occur, so it is preferable that (C) and (D) do not come into contact with each other in the manufacturing process. For example, it is preferable that (C) and (D) are not supplied simultaneously to the mixed system; for example, (C) is added first and then (D) is added under stirring, or (D) can be added first, and then (C) can be added. By supplying in this manner, gelation can be suppressed and appropriate coating properties can be imparted to the positive photosensitive resin composition. (C) and (D) are not particularly limited except for how to supply them, and they can be blended in any order. When using the (F) solvent, each component may be dissolved in the (F) solvent in advance and then mixed.

The viscosity of the positive photosensitive resin composition is preferably 20 mPa·s or more, more preferably 200 mPa·s or more, and preferably 50 Pa·s or less, more preferably 10 Pa·s or less. In this specification, viscosity is a value measured at 25°C using a cone-plate viscometer.

<Dry film>
The dry film of the present invention has a resin layer obtained by applying the positive photosensitive resin composition of the present invention onto a film and then drying the film. The dry film of the present invention is used by laminating the resin layer so as to be in contact with the base material.
The coating method is not particularly limited, and can be performed using a blade coater, lip coater, comma coater, film coater, or the like. The coating thickness can be selected depending on the coating method, viscosity, etc., but the coating thickness is preferably 100 μm or less in terms of the thickness of the resin layer after drying, and more preferably 5 μm or more and 50 μm or less.
The film (carrier film) on which the positive photosensitive resin composition is applied is not particularly limited, and thermoplastic films can be used, such as polyester films such as polyethylene terephthalate, polyimide films, and the like. The thickness of the film can be 2 μm or more and 150 μm or less.
The drying method is not particularly limited, and the drying temperature can be 70°C or higher and 140°C or lower. The thickness of the resin layer is preferably 100 μm or less, more preferably 5 μm or more and 50 μm or less.
It is preferable to laminate a cover film on the resin layer obtained by drying. The cover film may be made of the same material as the film (carrier film) or a different material, but it is preferable that the adhesive force with the resin layer is smaller than that of the film (carrier film).
As the cover film, polyethylene film, polypropylene film, etc. can also be suitably used.

<Cured product>
A cured product can be obtained by curing the resin layer of the positive photosensitive resin composition or dry film of the present invention. A patterned film made of a cured product can be manufactured as follows.
Step 1:
A coating film is obtained by applying the positive photosensitive resin composition of the present invention onto a substrate and drying it, or by transferring a resin layer from a dry film onto the substrate. The method of applying the positive photosensitive resin composition onto the substrate is not particularly limited, and examples include methods of applying with a spin coater, bar coater, blade coater, curtain coater, screen printer, etc., and spraying with a spray coater. method, inkjet method, etc. The method of drying the coating film is not particularly limited, and examples thereof include air drying, heating drying using an oven or hot plate, vacuum drying, and the like. It is preferable to dry the coating film under conditions that do not cause ring closure of the polybenzoxazole precursor (A). Specifically, drying is carried out under conditions that do not cause ring closure of the polybenzoxazole precursor (A). Drying may be carried out for at least 1 minute and at most 30 minutes, and preferably for at least 1 minute and at most 20 minutes on a hot plate. Vacuum drying is also possible, and in this case, drying may be carried out at room temperature (25° C.) for 20 minutes or more and 1 hour or less.
The base material is not particularly limited, and examples include semiconductor base materials such as silicon wafers, wiring boards, base materials made of resin or metal, and the like.

Step 2:
The coating film is exposed to light either through a patterned photomask or directly. The light beam used for exposure is a light beam with a wavelength capable of activating the photoacid generator (B) and generating acid, and specifically includes a light beam with a maximum wavelength in the range of 350 nm or more and 410 nm or less. . Photosensitivity may be adjusted using a sensitizer.
The exposure device is not particularly limited, and examples include contact aligners, mirror projections, steppers, laser direct exposure devices, and the like.

Step 3:
After exposure, the coating film may be heated to close a portion of the polybenzoxazole precursor (A) in the unexposed area. In this case, the ring closure rate is preferably about 30%, for example 10% or more and 40% or less. The heating time and heating temperature can be appropriately selected depending on the type of (A) polybenzoxazole precursor and (B) photoacid generator, coating thickness, etc.

Step 4:
The coating can then be treated with a developer to remove exposed portions of the coating to form a patterned film (uncured).
The developing method is not particularly limited, and any known photoresist developing method may be used, such as a rotary spray method, a paddle method, a dipping method accompanied by ultrasonic treatment, and the like.
The developing solution is not particularly limited, and includes inorganic alkalis such as sodium hydroxide, sodium carbonate, sodium silicate, and aqueous ammonia; organic amines such as ethylamine, diethylamine, triethylamine, and triethanolamine; tetramethylammonium hydroxide, and tetramethylammonium hydroxide. Examples include aqueous solutions of quaternary ammonium salts such as butylammonium hydroxide. Water-soluble organic solvents such as methanol, ethanol, isopropyl alcohol, and surfactants may be added.
Thereafter, the patterned film (uncured) may be washed with a rinsing liquid. The rinsing liquid is not particularly limited, and examples thereof include distilled water, methanol, ethanol, isopropyl alcohol, and the like. These may be used alone or in combination of two or more.

Step 5:
Next, the patterned film (uncured) is heated and cured to obtain a patterned film made of a cured product. By heating, the polybenzoxazole precursor (A) may be ring-closed and converted into polybenzoxazole. The heating conditions can be such that the polybenzoxazole precursor can undergo ring closure, and examples include heating at 150° C. or higher and 350° C. or lower for 5 minutes or more and 120 minutes or less in an inert gas. The heating temperature is preferably 200°C or more and 300°C or less. The heating device is not particularly limited, and examples thereof include a hot plate, an oven, and a heating oven in which a temperature program can be set. The atmosphere (gas) during heating may be air or an inert gas such as nitrogen or argon.

Applications of the positive photosensitive resin composition of the present invention are not particularly limited, and include printing inks, adhesives, fillers, electronic materials, optical circuit components, molding materials, resist materials, building materials, three-dimensional modeling, and optical components. etc. In particular, polybenzoxazole can be suitably used in fields where its properties such as heat resistance, dimensional stability, and insulation properties are effective, such as paints or printing inks, color filters, flexible display films, and semiconductor devices. Examples include coating films for electronic components, interlayer insulating films, coating films for printed wiring boards such as solder resists, optical circuits, optical circuit components, antireflection films, holograms, optical members, and materials for building materials.

Among these, the positive photosensitive resin composition of the present invention can be used as a pattern forming material (resist). The formed patterned film (cured product) is a permanent film containing polybenzoxazole that contributes to heat resistance and insulation, and is used for example in color filters, flexible display films, electronic components, coating films for semiconductor devices, and interlayer insulation. It can be suitably used for films, coating films for printed wiring boards such as solder resists and coverlay films, solder dams, optical circuits, optical circuit components, antireflection films, other optical members, electronic members, and the like.

EXAMPLES Hereinafter, the present invention will be explained in more detail using Examples, but the present invention is not limited thereto. In the following, "parts" and "%" are based on mass unless otherwise specified.

<Synthesis of polybenzoxazole precursor>
The polybenzoxazole precursor used in the examples was synthesized as follows.
212 g of N-methylpyrrolidone was placed in a 0.5 L flask equipped with a stirrer and a thermometer, and 28.00 g (76.5 mmol) of bis(3-amino-4-hydroxyamidophenyl)hexafluoropropane was dissolved with stirring. . Thereafter, the flask was immersed in an ice bath, and while keeping the inside of the flask at 0 to 5°C, 25.00 g (83.2 mmol) of 4,4-diphenyl ether dicarboxylic acid chloride was added as a solid in 5 g portions over 30 minutes. The mixture was stirred for 30 minutes. Thereafter, stirring was continued for 5 hours at room temperature. The stirred solution was poured into 1 L of ion-exchanged water (specific resistance value: 18.2 MΩ·cm), and the precipitate was collected. The collected precipitate was dissolved in 420 mL of acetone and poured into 1 L of ion exchange water. Thereafter, the precipitated solid was collected and dried under reduced pressure to obtain a polybenzoxazole precursor having the following repeating structure and having carboxyl group terminals. The polybenzoxazole precursor had a number average molecular weight (Mn) of 12,900, a weight average molecular weight (Mw) of 29,300, and an Mw/Mn of 2.28.

<Examples 1, 2, 4-8, Comparative Examples 1-3>
Pour 100g of the polybenzoxazole precursor, photoacid generator, optional crosslinking agent, and solvent into a light-shielding container in the amounts shown in Table 1 (the amounts of each component are expressed in parts by mass. The same applies below). The mixture was stirred at room temperature for 10 minutes. Next, an adhesion improver was added in the amount shown in Table 1. Stirring was then continued for 5 minutes. After adding the adhesion improver, a coupling agent was added in the amount shown in Table 1 while stirring, and the mixture was stirred for 10 minutes to obtain a varnish.

<Example 3>
100 g of the polybenzoxazole precursor, photoacid generator, crosslinking agent, and solvent were added to a light-shielding container in the amounts shown in Table 1, and stirred at room temperature for 10 minutes. A coupling agent was then added in the amount shown in Table 1. Stirring was then continued for 5 minutes. After adding the coupling agent, an adhesion improver was added in the amount shown in Table 1 while stirring, and the mixture was stirred for 10 minutes to obtain a varnish.

<Reference example>
A polybenzoxazole precursor, a photoacid generator, a crosslinking agent, a solvent, a coupling agent, and an adhesion improver were simultaneously added in the amounts shown in Table 1 and stirred to obtain a varnish.

Components other than the polybenzoxazole precursor used in the examples are as follows.

（三宝化学研究所社製、ＴＫＦ-４２８） Photoacid generator:

(Manufactured by Sanpo Chemical Research Institute, TKF-428)

（信越化学工業社製、ＫＢＥ－９０３）
シランカップリング剤２：

（信越化学工業社製、ＫＢＭ－５７３）
シランカップリング剤３（比較剤）：

（信越化学工業社製、ＫＢＥ－４０３） Silane coupling agent 1:

(Manufactured by Shin-Etsu Chemical Co., Ltd., KBE-903)
Silane coupling agent 2:

(Manufactured by Shin-Etsu Chemical Co., Ltd., KBM-573)
Silane coupling agent 3 (comparative agent):

(Manufactured by Shin-Etsu Chemical Co., Ltd., KBE-403)

Adhesion improver:
BYK-4512 manufactured by BYK Chemie Japan Co., Ltd.
Amine value 56mgKOH/g
(Non-volatile content: 60%. Solvent: methoxypropyl acetate. The amounts in Table 1 include the solvent.)

（旭有機材社製、ＴＭ－ＢＩＰ－Ａ）
架橋剤２：

（三和ケミカル社製、ＭＷ－３９０）
架橋剤３：

（ＤＩＣ社製、ＨＰ－４０３２Ｄ） Crosslinking agent 1:

(Manufactured by Asahi Yukizai Co., Ltd., TM-BIP-A)
Crosslinking agent 2:

(Manufactured by Sanwa Chemical Co., Ltd., MW-390)
Crosslinking agent 3:

(Manufactured by DIC, HP-4032D)

Solvent: γ-butyrolactone

The varnishes of each example were evaluated as follows. The evaluation results are shown in Table 1.
<Gelification and storage stability>
The resulting varnish was kept at 4°C for 14 days. The viscosity before storage and after 14 days was measured using a cone plate viscometer (TPE-100, manufactured by Toki Sangyo Co., Ltd., rotation speed 50 rpm, 25° C.), and the viscosity increase rate was calculated. The results are shown in Table 1.
◎: Viscosity increase rate is less than 5%. ○: Viscosity increase rate is 5% or more and less than 10%. △: Viscosity increase rate is 10% or more and less than 15%. ×: Viscosity increase rate is 15% or more or cannot be measured due to gelation.

<Adhesion>
The obtained varnish was applied to a film thickness of 8 μm onto a silicon substrate or a copper plate using a spin coater. It was dried on a hot plate at 120°C for 3 minutes to obtain a dry coating film.
A total of 100 squares with a size of 1×1 (mm) were formed in a grid of 10 rows and columns on the obtained dried coating film using a cutter knife. This sample was subjected to a pressure cooker (PCT) test (conditions: continuous treatment for 50 hours at a temperature of 121° C. and a humidity of 100%), and then the grid pattern was peeled off with tape. Adhesion was evaluated by counting the number of peeled off grids.

<Sensitivity>
The obtained varnish was applied to a film thickness of 8 μm on a silicon substrate using a spin coater. It was dried on a hot plate at 110°C for 3 minutes to obtain a dry coating film. The obtained dried coating film was irradiated with broad light using a high-pressure mercury lamp through a mask having a pattern (L/S=10 μm/10 μm) carved therein. After exposure, the film was developed with a 2.38% tetramethylammonium hydroxide (TMAH) aqueous solution for 60 seconds and rinsed with water to obtain a positive pattern film. The positive pattern film was observed using an electron microscope (SEM "JSM-6010"). Experiments were conducted by varying the exposure amount, and the minimum exposure amount that could pattern the exposed area without scum (development residue) was evaluated as the sensitivity (mJ/cm ² ).

<Residual film rate>
Measure the film thickness of the unexposed area of the positive pattern film obtained by the same method as the sensitivity evaluation above, calculate the ratio of the film thickness to the film thickness before development to determine the remaining film rate of the unexposed area, and use the following criteria. evaluated.
Remaining film rate (%) = (Thickness of unexposed area after development (μm)/Thickness of unexposed area before development (μm)) x 100
◎: Unexposed area residual film rate is 95% or more ○: Unexposed area residual film rate is less than 95% and 90% or more △: Unexposed area residual film rate is less than 90% and 80% or more ×: Unexposed area residual film rate less than 80% or could not be confirmed due to peeling

<Elongation rate>
The obtained varnish was applied to a film thickness of 40 μm onto a silicon substrate sputtered with aluminum using a spin coater. Dry on a hot plate for 3 minutes at 110°C, then heat at 110°C for 10 minutes in a nitrogen atmosphere in an inert gas oven (manufactured by Koyo Thermo Systems, CLH-21CD-S), hold at 150°C for 30 minutes, and hold at 220°C for 30 minutes. C. for 60 minutes to obtain a cured film with a thickness of about 30 μm. After immersing the obtained cured film in 10% hydrochloric acid and peeling it off from the substrate, the elongation at break was determined by a tensile test using a small tabletop tester (manufactured by Shimadzu Corporation, EZ-SX), and evaluated according to the following criteria. .
◎: Elongation at break is 40% or more ○: Elongation at break is less than 40% 35% or more ×: Elongation at break is less than 35%

Examples 1 to 8 all had excellent adhesion to both silicon substrates and copper plates, excellent patterning properties as shown by good film retention and sensitivity, and excellent elongation. From Examples 6 to 8, it can be seen that the residual film ratio is further improved by adding a crosslinking agent. On the other hand, in Comparative Example 1 lacking (C), adhesion to the silicon substrate could not be obtained and the remaining film rate was also poor. Comparative Example 2, which lacked (D), could not achieve adhesion to a copper plate, its adhesion to a silicon substrate was not as good as that of the example, and its elongation rate was also poor. In Comparative Example 3 using a silane coupling agent other than (C), adhesion to the silicon substrate and copper plate could not be obtained, the sensitivity was poor, and unexposed areas peeled off, making it impossible to confirm the residual film rate. Comparative Example 3 also fell short of the Examples in terms of elongation rate.

The positive photosensitive resin composition of the present invention has excellent adhesion and patterning properties, and can provide a cured product with good elongation, so it is highly useful industrially.

Claims (7)

(A) one or more polybenzoxazole precursors,
(B) one or more photoacid generators,
(C) a silane coupling agent containing one or more nitrogen atoms; and (D) one or more adhesion improvers having an amine value of 20 mgKOH/g or more and 100 mgKOH/g or less. ,
A positive photosensitive resin composition in which the mass ratio of (C) and (D) (mass of (C): mass of (D)) is 1:0.2 to 1:10,
Here, (C) consists only of an amino group-containing alkoxysilane in which the nitrogen atom of the amino group and the silicon atom of the silyl group are bonded via a hydrocarbon group having 1 to 10 carbon atoms,
(D) consists only of a polymer adhesion improver having a number average molecular weight (Mn) of 200 or more and 20,000 or less, and the polymer adhesion improver is CAS No. 1788896-49-0 and CAS No. Selected from 2255343-54-3,
Positive photosensitive resin composition . The positive photosensitive resin composition according to claim 1, further comprising (E) a crosslinking agent. (A) For 100 parts by mass,
(B) is 0.5 parts by mass or more and 40 parts by mass or less,
The positive photosensitive resin composition according to claim 1 or 2, wherein (C) is 0.1 parts by mass or more and 10 parts by mass or less, and (D) is 0.1 parts by mass or more and 10 parts by mass or less. A dry film having a resin layer obtained by applying the positive photosensitive resin composition according to any one of claims 1 to 3 onto a film and drying it. A cured product obtained by curing the positive photosensitive resin composition according to any one of claims 1 to 3 or the resin layer of the dry film according to claim 4. An electronic component comprising the cured product according to claim 5. A method for producing a positive photosensitive resin composition according to any one of claims 1 to 3, wherein (C) is added while (A) and (B) are stirred in a solvent, and then ( A method of adding D), or a method of adding (D) and then adding (C).