WO2020246565A1

WO2020246565A1 - Photosensitive polyimide resin composition

Info

Publication number: WO2020246565A1
Application number: PCT/JP2020/022220
Authority: WO
Inventors: 鈴木　鉄秋; 稲太郎黒沢
Original assignee: 株式会社ピーアイ技術研究所
Priority date: 2019-06-06
Filing date: 2020-06-05
Publication date: 2020-12-10
Also published as: TW202104371A; JPWO2020246565A1; KR20220018957A; CN113994257A

Abstract

The purpose of the present invention is to provide a photosensitive polyimide resin composition which has developer liquid solubility during development and developer liquid insolubility after photo-crosslinking, and which enables the achievement of good film properties and high sensitivity.　The present invention provides a photosensitive polyimide resin composition which contains, as essential components, (A) a solvent-soluble polyimide and (B) a diazide compound, wherein: the solvent-soluble polyimide (A) is a block copolymer that comprises, in the main chain, (a) an aromatic tetracarboxylic acid dianhydride residue having a benzophenone structure and (b) a residue of at least one diamine that is selected from the group consisting of an aromatic diamine having an alkyl group at the ortho position of an amino group, an aromatic diamine having an indane structure, and a diamine having a polysiloxane structure; and the content of the diazide compound (B) is from 2.0 to 150 parts by weight relative to 100 parts by weight of the solvent-soluble polyimide (A).

Description

Photosensitive polyimide resin composition

The present invention relates to a photosensitive polyimide resin composition.

In recent years, in semiconductor package substrates, Fan-out Wafer Level Package (FO-WLP) that can reduce the height, improve the electrical characteristics (R, L, C), and reduce the warp from FC-CSP and FC-BGA. ) Is being actively considered, and a part of FO-WLP has been mass-produced. The key materials in the organic material used for this FO-WLP are a sealing material and various protective film materials, and photosensitive polyimide is used as the protective film material.

It is known that photosensitive polyimide has several photosensitizing methods (Patent Document 1), and is roughly classified into a positive type and a negative type according to the image forming process. The positive type has higher sensitivity than the negative type, but it is difficult to expect improvement in physical properties due to the photoreaction because it uses a photodecomposition reaction. On the other hand, the negative type has a feature that the chemical resistance and the heat resistance are easily improved because the exposed portion undergoes a photocrosslinking reaction and remains after the development treatment. Therefore, the negative type has some problems in sensitivity when used as a permanent insulating film, but can provide a highly reliable one.

Negative photosensitive polyimide is roughly classified into a method in which a photosensitive group is introduced into a precursor such as polyamic acid and heat imidization is performed after a photoreaction, and a method in which the ring-closed polyimide itself is made photosensitive. Typical methods that have been put into practical use in this field are those in which a polyamic acid is ester-bonded with a hydroxy acrylate (Patent Document 2), or a polyamic acid mixed with an amino acrylate or the like and a photosensitive group is introduced by a salt bond. (Patent Document 3).

Further, as a method for making the ring-closed polyimide itself photosensitive, a method using a polyimide copolymer obtained by a polycondensation reaction between a tetracarboxylic acid dianhydride having a benzophenone structure and a diamine (Patent Document 4) and , A method of adding an acryloyl group to the side chain of a solvent-soluble polyimide block copolymer synthesized by two-step polycondensation has been reported (Patent Document 5).

Kenichi Fukuda, Mitsuru Ueda, Polymer Papers, vol63, No. 9, pp. 561-576 Special Publication No. 55-41422 JP-A-54-145794 Japanese Unexamined Patent Publication No. 5-39281 Japanese Unexamined Patent Publication No. 2000-147768

The demands for semiconductor package substrates, etc. are becoming stricter year by year, and FO-WLP is no exception, and there are demands for thinner patterns, smaller diameters of connecting vias, and multiple layers. In order to meet these demands, photosensitive polyimide also has improved sensitivity, reliability of thin films, and reduction of warpage in large panel sizes, which is deeply involved in cost reduction, which is the biggest issue of FO-WLP. And improvement of dimensional stability is required.

However, the currently practical method of performing heat imidization after a photoreaction using a polyamic acid requires a high temperature (for example, 350 to 450 ° C.) for imidization, and at that time, dehydration shrinkage or a photosensitive group. Desorption or volatilization occurs, and large film burrs occur. This has had a great influence on warpage and dimensional stability in the manufacturing process of semiconductor packages and electronic devices, and has been a factor of lowering storage stability.

Further, even when a ring-closed polyimide is used, there is a problem that it is necessary to have a structure in which the developing solution is soluble at the time of development and the photosensitive part becomes insoluble in the developing solution after exposure, and the conventionally reported method has a problem. There was a problem that the exposure and developability were insufficient.

As described above, as a protective film material for a semiconductor package substrate or the like, a photosensitive polyimide which is soluble in a developing solution during development and insoluble in a developing solution after photocrosslinking, and which can achieve good film physical properties and improved sensitivity is required. Was being done.

An object of the present invention is to provide a photosensitive polyimide resin composition which is soluble in a developing solution during development and insoluble in a developing solution after photocrosslinking, and can achieve good film physical properties and high sensitivity.

As a result of diligent studies to solve the above problems, the present inventors have made a block copolymer having a ring-closed polyimide having an aromatic acid dianhydride having a benzophenone structure and a specific diamine in the main chain. By further combining this polyimide with a specific amount of diazid compound, a photosensitive polyimide resin composition having solvent solubility during development and solvent insolubility after photocrosslinking, which can achieve good film physical properties and high sensitivity, can be obtained. The present invention has been completed by finding that it can be provided.

That is, the present invention provides the following.
(1) A photosensitive polyimide resin composition containing (A) a solvent-soluble polyimide and (B) a diamine compound as essential components, wherein the (A) solvent-soluble polyimide has (a) an aromatic tetra having a benzophenone structure. At least one selected from the group consisting of a carboxylic acid dianhydride residue, (b) an aromatic diamine having an alkyl group at the ortho position of the amino group, an aromatic diamine having an indan structure, and a diamine having a polysiloxane structure. It is a block copolymer having a diamine residue in the main chain, and the content of the (B) diazide compound is 2.0 to 150 parts by weight with respect to 100 parts by weight of the (A) solvent-soluble polyimide. Photosensitive polyimide resin composition.
(2) The resin composition according to (1), wherein the residue of at least one of the diamines is a residue of an aromatic diamine having a phenylindane structure.
(3) The resin composition according to (1) or (2), wherein the (B) diazide compound is 2,6-di (4'-azidobenzal) -4-ethylcyclohexanone.
(4) The resin composition according to any one of (1) to (3), wherein the photosensitive polyimide resin composition further contains (C) an epoxy resin and (D) a photobase generator. Stuff.
(5) The resin composition according to any one of (1) to (4), wherein the photosensitive polyimide resin composition is a negative solvent developing composition.
(6) A pattern forming method comprising exposing a substrate coated with the resin composition according to any one of (1) to (5) by ultraviolet irradiation to develop and remove an unexposed portion.
(7) A semiconductor package, electronic element, display element or organic multilayer wiring board having an interlayer insulating film, a passivation film or a surface protective film formed by using the resin composition according to any one of (1) to (5). ..

According to the present invention, by using a ring-closed photosensitive polyimide and a specific amount of diazide compound without using a polyamic acid that requires imidization at a high temperature, both solvent-soluble during development and solvent-insolubility after photocrosslinking are used. It is possible to provide a photosensitive polyimide resin composition which can achieve good film physical properties and high sensitivity equal to or higher than that of photosensitive polyimide using polyamic acid.

When a polyimide having a benzophenone skeleton, which has been used conventionally, is used, the quantum yield of hydrogen abstraction cross-linking between the benzophenone portion and the adjacent alkyl group is low and a sufficient cross-linked structure cannot be obtained. A sufficient crosslinked structure of polyimide can be realized by adding a diazide compound to the composition.

Further, when the thickness of the film formed by using the polyimide resin composition is large, for example, when it is 10 μm or more, the polyimide resin composition contains a photobase generator and an epoxy resin, and the photobase generator is used. A sufficient crosslinked structure can be realized by photocrosslinking the epoxy resin.

The photosensitive polyimide resin composition of the present invention is a resin composition containing (A) a solvent-soluble polyimide and (B) a diazide compound as essential components.

(A) Solvent-soluble polyimide The (A) solvent-soluble polyimide in the present invention comprises (a) an aromatic acid dianhydride having a benzophenone structure and (b-1) an aromatic diamine having an alkyl group at the ortho position of the amino group. , (B-2) A block copolymer having at least one diamine (b) in the main chain selected from the group consisting of an aromatic diamine having an indan structure and (b-3) a diamine having a polysiloxane structure. Is.

Specifically, the solvent-soluble polyimide (A) of the present invention is a block copolymer having at least one, preferably two or more of the repeating units represented by the following general formulas [I] to [III]. Is.

(In the formula, Z ¹ is an aromatic tetracarboxylic dianhydride residue, and Ar ¹ is an aromatic diamine residue having an alkyl group at the ortho position of the amino group.)

(In the formula, Z ² is an aromatic tetracarboxylic dianhydride residue and Ar ² is an aromatic diamine residue having an indane structure.)

(In the formula, Z ³ is an aromatic tetracarboxylic dianhydride residue and Ar ³ is a diamine residue having a polysiloxane structure).

In the present invention, at least one of Z ¹ in the general formula [I], Z ^{2 in} the general formula [II], and Z ^{3 in} the general formula [III] has (a) a benzophenone structure. Although it is an aromatic tetracarboxylic dianhydride residue having, it is preferable that Z ¹ , Z ² and Z ³ are all (a) aromatic tetracarboxylic dianhydride residues having a benzophenone structure.

Examples of the aromatic acid dianhydride (a) which is an aromatic acid dianhydride residue having a benzophenone structure in the present invention include 2,2', 3,3'-benzophenonetetracarboxylic dianhydride (BTDA). Examples thereof include 4,5,3', 4'-benzophenonetetracarboxylic dianhydride (BTDA) and 3,3', 4,4'-benzophenonetetracarboxylic dianhydride (BTDA). The morphology of BTDA-based polyimide also changes due to photocrosslinking. That is, it is said that the agglutinated state is densified. This also contributes to the improvement of chemical resistance and heat resistance.

The aromatic dianhydride having a benzophenone structure is preferably contained in an amount of 10 mol% or more, 45 mol% or more, and further 50 mol% or more of all the aromatic acid dianhydrides constituting the solvent-soluble polyimide. When the content of the aromatic dianhydride having a benzophenone structure is less than 10 mol%, the solvent resistance of the polyimide resin composition after photocrosslinking tends to decrease, and the sensitivity tends to decrease.

Examples other than the aromatic tetracarboxylic dianhydride residue having the benzophenone structure of Z ¹ , Z ² and Z ^{3 in} the above general formulas [I] to [III] are not particularly limited, but are pyromellitic dianhydride. Anhydride, 3,4,3', 4'-benzophenonetetracarboxylic dianhydride, 3,4,3', 4'-diphenyltetracarboxylic dianhydride, bis- (3,4-dicarboxyphenyl) Examples include ether dianhydride, 2,2-bis- (3,4-dicarboxyphenyl) hexafluoropropane, anhydride, 4,4'-oxydiphthalic dianhydride and the like.

Further, the solvent-soluble polyimide (A) may have a repeating unit composed of an aromatic tetracarboxylic dianhydride residue and a diamine residue other than the above general formulas [I] to [III].

(B) Diamine (b-1) Aromatic diamine having an alkyl group at the ortho position of the amino group The aromatic diamine residue (Ar ¹ ) having an alkyl group at the ortho position of the amino group in the present invention is an amino group. Specific examples thereof include aromatic amine residues having a linear or branched alkyl group having 1 to 12 carbon atoms, preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms at the ortho position. Is a structure represented by the following formulas (1) to (3).

In the above formula (1), the free bond (two bond positions where the amino group is bonded) exists in the meta position or the para position relative to each other.
In the above formula (2), the free bond (two bond positions where the amino group is bonded) is preferably present at the meta position or the para position with respect to R ₁₁ , and R ₅ and R ₆ are at the two ortho positions of the free bond. Is bound to. R ₁₁ is -O-, -S-, -SS-, -SO-, -SO _2- , -CO-, -COO-, -NH-, -CONH-, -CON-alkyl group- (alkyl group The number of carbon atoms n represents 1 to 6), -CON-benzyl group-.
In the above formula (3), the free bond (two coupling positions where the amino group is bound) is 2-, 3-, 6- or 7-position to present, _{R 5} and _{R 6} are two ortho positions of the free bond Is bound to.
In the above formulas (1) to (3), R ₅ and R ₆ are linear or branched alkyl groups having 1 to 12 carbon atoms, preferably alkyl groups having 1 to 5 carbon atoms, and more preferably 1 to 3 carbon atoms. Alkyl group of.

In the present invention, the aromatic diamine residue (Ar ¹ ) having an alkyl group at the ortho position of the amino group is 30 mol% or more, more particularly 50 mol% or more, particularly 50 mol% or more in all the diamines constituting the (A) solvent-soluble polyimide. Is preferably contained in an amount of 70 mol% or more. If it is less than 50 mol%, the crosslink density tends to decrease.

(B-2) Aromatic diamine having an indane structure In the present invention, the aromatic diamine residue (Ar ² ) having an indane structure is represented by the following formula (IV) or (V) in the following indane skeleton. Those having such a structure can be mentioned.

In the above formula (IV), R ₁ and R ₂ represent an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms or an alkoxy alkyl group having 2 to 12 carbon atoms, and R ₁ and R ₂ are free. It is preferably bonded to two ortho positions of the bond (two bonding positions to which the amino group is bonded).

In the above formula (V), R ₁ , R ₂ and R ₃ independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and each of R ₄ and R ₅ independently represents a hydrogen atom or carbon. Represents an alkyl group of numbers 1-5. Specific examples include 5-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane and 6-amino-1- (4'-aminophenyl) -1,3,3-trimethylindane. Can be mentioned.
In the present invention, a solvent-soluble polyimide having an aromatic diamine residue having a phenylindane structure represented by the above formula (V) in the main chain is preferable.

The aromatic diamine residue (Ar ² ) having an indane structure in the present invention should be contained in all the diamines constituting the solvent-soluble polyimide (A) in an amount of 50 mol% or more, further 60 mol% or more, particularly 70 mol% or more. Is preferable. If it is less than 50 mol%, the crosslink density tends to decrease.

(B-3) Diamine residue having a polysiloxane structure (Ar ³ )
Examples of the diamine residue (Ar ³ ) having a polysiloxane structure in the present invention include α, ω-bis (2-aminoethyl) polydimethylsiloxane, α, ω-bis (3-aminopropyl) polydimethylsiloxane, α, ω-bis (4-aminophenyl) polydimethylsiloxane, α, ω-bis (4-amino-3-methylphenyl) polydimethylsiloxane, α, ω-bis (3-aminopropyl) polydiphenylsiloxane, α, ω -Bis (4-aminobutyl) polydimethylsiloxane and the like can be mentioned.

The diamine residue (Ar ³ ) having a polysiloxane structure in the present invention is preferably contained in an amount of 2.0 to 30 mol%, preferably 5.0 to 20 mol%, in all the diamines constituting the solvent-soluble polyimide (A). It is more preferable to let it. If the content of the diamine having a polysiloxane structure exceeds 30 mol%, the solvent solubility may become too high, and Tg also tends to decrease.

(A) Method for synthesizing solvent-soluble polyimide A known method may be used for synthesizing the solvent-soluble polyimide, and the method is not particularly limited. However, the above-mentioned tetracarboxylic acid dianhydride and aromatic diamine are used in substantially equal amounts to form an organic polarity. A solvent-soluble polyimide can be synthesized by reacting in a solvent at 160 to 200 ° C. for several hours in the presence of a catalyst and a dehydrating agent. Examples of the organic polar solvent include N-methylpyrrolidone (NMP), γ-butyrolactone, N, N'-dimethylacetamide, N, N'-dimethylformamide, dimethyl sulfoxide, tetramethylurea, tetrahydrothiophene-1,1-oxide and the like. Is used.

The solvent-soluble polyimide (A) in the present invention is a block copolymer and can be synthesized by performing a block copolymer reaction as needed. For example, it can be produced by a two-step sequential addition reaction, in which the polyimide oligomer is synthesized from the tetracarboxylic acid dianhydride and the aromatic diamine in the first step, and then further in the second step, the tetracarboxylic acid dianhydride and / Or an aromatic diamine can be added and polycondensed to obtain a block copolymer polyimide.

As the catalyst for the block copolymerization reaction, the dehydration imidization reaction can be promoted by using a two-component acid-base catalyst utilizing the equilibrium reaction of lactone. Specifically, a two-component catalyst of γ-valerolactone and pyridine or N-methylmorpholine is used. As shown in the following formula, water is generated as the imidization progresses, and the produced water participates in the equilibrium of the lactone to become an acid-base catalyst and exhibits catalytic action.

The water produced by the imidization reaction is removed from the system by azeotropic boiling with a dehydrating agent such as toluene or xylene coexisting in the polar solvent. When the reaction is completed, the water in the solution is removed, and the acid-base catalyst becomes γ-valerolactone and pyridine or N-methylmorpholine, which is removed from the system. In this way, a high-purity polyimide solution can be obtained.

As the other two-component catalyst, oxalic acid or malonic acid and pyridine or N-methylmorpholine can be used. In the reaction solution at 160-200 ° C., oxalate or malonate promotes the imidization reaction as an acid catalyst. A catalytic amount of oxalic acid or malonic acid remains in the produced polyimide solvent. After applying this polyimide solution to the substrate, it is heated to 200 ° C. or higher, and when the solvent is removed to form a film, the oxalic acid or malonic acid remaining in the polyimide is thermally decomposed as shown in the following formula. Excluded from the system as gas.

By the above method, high-purity (A) solvent-soluble polyimide can be obtained. The oxalic acid-pyridine catalyst has stronger activity than the Valerolactone-pyridine catalyst, and can produce a high molecular weight polyimide in a short time.

The term "solvent-soluble" in the present invention is a term used for an organic polar solvent used in the synthesis of polyimide and a solvent used for a film described later, and is a polyimide that dissolves 5 g or more in 100 g of a solvent. Means that. Here, examples of the solvent include polar solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, sulfolane, and tetramethylurea.

The solvent-soluble polyimide (A) synthesized as described above is used in the state of a solution dissolved in the organic polar solvent or the solvent used for the membrane described later so that the solid content is, for example, 10 to 30% by weight. be able to. The molecular weight of the solvent-soluble polyimide (A) is preferably 10,000 to 400,000 as a polystyrene-equivalent weight average molecular weight. Within this range, good solvent solubility, film physical properties and insulating properties can be achieved. The appropriate viscosity of the solvent-soluble polyimide (A) is when the solid content is 20 to 40% by weight, preferably 2 to 10 Pa · s / 25 ° C. The glass transition temperature (Tg) (according to the TMA measurement method) of the solvent-soluble polyimide is preferably 200 ° C. or higher, more preferably 250 ° C. or higher.

The concentration of the solvent-soluble polyimide (A) in the solution is preferably 5 to 50% by weight, more preferably 10 to 40% by weight. The polyimide obtained by the direct imidization reaction using the above-mentioned catalytic system composed of lactone and base can be obtained in the form of a solution dissolved in a polar solvent, and the concentration of the polyimide is also within the above-mentioned preferable range. Therefore, the produced polyimide solution can be preferably used as it is.

The produced polyimide solution can be further diluted with a diluent if desired. Diluents include solvents that do not significantly impair solubility, such as dioxane, dioxolane, N-methyl-2-pyrrolidone, γ-butyrolactone, cyclohexanone, cyclopentanone, propylene glycol monomethyl ether acetate, methyl lactate, anisole, etc. Examples thereof include, but are not limited to, methyl benzoate and ethyl acetate.

(B) Diazide Compound In the present invention, by adding the (B) diazide compound as another essential component to the photosensitive polyimide resin composition, there is an effect that the exposure and developability are remarkably improved.

(B) Examples of the diazide compound include 4,4'-diazidobenzalacetophenone, 2,6-di (4'-azidobenzal) cyclohexanone, and 2,6-di (4'-azidobenzal) -4-methylcyclohexanone, 2. , 6-di (4'-azidobenzal) -4-ethylcyclohexanone, 2,6-di (4'-azidobenzal) -4-t-amylcyclohexanone, 4,4'-diazidodiphenylsulfone, 4,4'- Examples thereof include diazidodiphenyl ether, 4,4'-diazidephenyl sulfide, and 4,4'-diazidodiphenylmethane. Among these, those having an azidobenzalcyclohexanone structure are preferable, and 2,6-di (4'-azidobenzal) -4-ethylcyclohexanone is particularly excellent from the viewpoint of crosslinkability and storage stability.

The diazide compound is contained in the photosensitive polyimide resin composition in an amount of 2.0 to 150 parts by weight, more preferably 5.0 to 100 parts by weight, particularly 10.0, based on 100 parts by weight of the solvent-soluble polyimide (A). It is preferably contained in an amount of about 80 parts by weight. If it is less than 2.0 parts by weight, the crosslink density tends to decrease, and if it exceeds 150 parts by weight, the physical properties of the film tend to decrease. A diazirine compound, maleimide or bismaleimide compound may be used in combination to complement the crosslinkability.

Since the photosensitive polyimide resin composition of the present invention is inferior in light transmission on the low wavelength side, the pattern shape tends to have a reverse taper seen in negative solvent development, especially in the case of a thick film specification. In order to improve this, it has been found that it is also effective to use a photosensitive monomer or polymer of a different photosensitive cross-linking length method in combination. Among them, the most effective component of the photosensitive polyimide resin composition of the present invention is a combination of (C) epoxy resin and (D) photobase generator, which are excellent in compatibility with the photosensitive polyimide resin composition. I found that there is.

(C) Epoxy resin The (C) epoxy resin is not particularly limited and can be selected depending on the reactivity with the photobase generator and the compatibility with the photosensitive polyimide resin composition, and can be selected as the epoxy resin. For example, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolut type epoxy resin, triazine skeleton-containing epoxy resin, fluorene skeleton-containing epoxy resin, naphthalene-type epoxy resin, biphenyl-type epoxy resin, crystalline epoxy resin, Bisphenol A type epoxy resins and the like can be used, and their high molecular weight epoxy resins can also be used. The content of the (C) epoxy resin in the photosensitive polyimide resin composition is preferably 2 to 50 parts by weight, most preferably 2 to 20 parts by weight, based on 100 parts by weight of the solvent-soluble polyimide (A).

(D) Photobase generator (D) Photobase generator is a component that generates an anion (base) by irradiation with ultraviolet rays, and is roughly classified into a nonionic type and an ionic type. The non-ionic type includes those that absorb light to generate primary amines, secondary amines, imidazoles, and the like, and the ionic types include those that generate organic strong bases such as amidine, guanidine, and phosphazene.
As for (D) photobase generators, those that generate primary amines and secondary amines in the reaction with (C) epoxy resin are unlikely to undergo a chain reaction, so imidazole in the nonionic type and imidazole in the ionic type. Those that generate amidine, guanidine, etc. are preferable.

A commercially available product can be used as the (D) photobase generator in the present invention. For example, WPBG-018, WPBG-140, WPBG-266, WPBG-300, WPBG-345, WPBG-027, WPBG-165 (all manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) and the like can be mentioned.
The content of the (D) photobase generator in the photosensitive polyimide resin composition is preferably 0.5 to 8% by weight, more preferably 1 to 6% by weight, based on the (C) epoxy resin.

(Photosensitizer)
The photosensitive polyimide resin composition of the present invention may contain a photosensitizer in order to be suitable for each final use, and the sensitivity of pattern resolution can be increased. As the photosensitizer, those that act on the long wavelength (> 350 nm) side are particularly preferable. Examples of the photosensitizer include anthracene-based sensitizers and thioxanthone-based sensitizers. The content of the photosensitizer is preferably about 0.3 to 2% by weight with respect to the photosensitive polyimide resin composition.

Specific examples of anthracene-based sensitizers include, for example, 9,10-dimethoxyanthracene, 9,10-diethoxyanthracene, 9,10-dipropoxyanthracene, 9,10-diisopropoxyanthracene, 9,10-di. Butoxyanthracene, 9,10-dipentyloxyanthracene, 9,10-dihexyloxyanthracene, 9,10-bis (2-methoxyethoxy) anthracene, 9,10-bis (2-ethoxyethoxy) anthracene, 9,10-bis (2-Butoxyethoxy) anthracene, 9,10-bis (3-butoxypropoxy) anthracene, 2-methyl- or 2-ethyl-9,10 dimethoxyanthracene, 2-methyl- or 2-ethyl-9,10-di Ethoxyanthracene, 2-methyl- or 2-ethyl-9,10-dipropoxyanthracene, 2-methyl- or 2-ethyl-9,10-diisopropoxyanthracene, 2-methyl- or 2-ethyl-9,10 -Dibutoxyanthracene, 2-methyl- or 2-ethyl-9,10-dipentyloxyanthracene, 2-methyl- or 2-ethyl-9,10-dihexyloxyanthracene, and the like.
Commercially available products can be used as the anthracene-based sensitizer. Examples of commercially available products include "Antracure UVS-1331", "Antracure UVS-1101" and "Antracure UVS-1221" (all manufactured by Kawasaki Kasei Chemicals, Inc.).

Examples of the thioxanthone-based sensitizer include 2-isopropylthioxanthone, 4-isopropylthioxanthone, 2,4-diethylthioxanthone, chloropropoxythioxanthone and the like. A commercially available product can be used as the thioxanthone-based sensitizer. Examples of commercially available products include "KAYACURE DETX-S" (manufactured by Nippon Kayaku Co., Ltd.), "Speedcure ITX", "Speedcure DETX", and "Speedcure CPTX" (manufactured by LAMBSON).

(Other additives)
The photosensitive polyimide resin composition of the present invention includes a modifier added to a normal photosensitive polyimide resin composition, for example, a coupling agent, a plasticizer, a film-forming resin, a surfactant, a stabilizer, and a spectrum. A sensitivity adjuster or the like may be added. In particular, when the adhesion of polyimide to the substrate is not good, coupling agents such as vinyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropyltrimethoxy Silane, 3-aminopropyltrimethoxysilane, tris- (trimethoxysilylpropyl) isocyanurate, 3-ureidopropyltrialkoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-isocyanatepropyltriethoxysilane, 3-trimethoxysilyl Silane cups of propyl succinic anhydride, hexamethyldisiloxane, hexamethyldisilazane, 1,3-bis (3-aminopropyl) tetramethyldisiloxane, N- [3- (triethoxysilyl) propyl] phthalamic acid, etc. Adhesion to the substrate can be improved by adding a ring agent. In this case, the amount of the silane coupling agent added is preferably 0.1 to 5% by weight of the photosensitive polyimide resin composition.

Further, when a substrate made of copper or a copper alloy is used, an azole compound can be added to the photosensitive polyimide resin composition in order to suppress discoloration of the substrate. Examples of the azole compound include 1H-benzotriazole, tolyltriazole, 5-methyl-1H-benzotriazole, 4-methyl-1H-benzotriazole, 5-carboxy-1H-benzotriazole and 4-carboxy-1H. -Benzotriazole and the like can be mentioned. In this case, the amount of the azole compound added is preferably 0.1 to 1% by weight of the photosensitive polyimide resin composition.

Further, a hindered phenol compound can be added to the photosensitive polyimide resin composition in order to suppress discoloration on copper.
Examples of the hindered phenol compound include 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) -1,3,5-triazine-2,4,6-( 1H, 3H, 5H) -trione, 1,3,5-tris (4-t-butyl-5-ethyl-3-hydroxy-2,6-dimethylbenzyl) -1,3,5-triazine-2,4 , 6- (1H, 3H, 5H) -trione and 1,3,5-tris (4-triethylmethyl-3-hydroxy-2,6-dimethylbenzyl) -1,3,5-triazine-2,4 , 6- (1H, 3H, 5H) -trion and the like.
In this case, the amount of the hindered phenol compound added is preferably 0.1 to 2% by weight of the photosensitive polyimide resin composition. In addition, examples of other resins that can be used in combination include polyarylate resin and polyether sulfone resin.

The photosensitive polyimide resin composition of the present invention can be in the form of a solution suitable for application on a substrate. In this case, as the solvent, a polar solvent such as N-methyl-2-pyrrolidone, γ-butyrolactone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, sulfolane, or tetramethylurea, which is used as a solvent for the imidization reaction, may be used. it can.

Method for Producing Photosensitive Polyimide Pattern A photosensitive polyimide pattern can be produced on a substrate by using a photosensitive polyimide resin composition containing the above-mentioned components. Specifically, (1) a step of forming a resin layer on the substrate by applying the above-mentioned photosensitive polyimide resin composition of the present invention on the substrate, and (2) a step of exposing the resin layer. , (3) A step of developing the exposed resin layer to form an insulating material for electronic parts and a photosensitive polyimide pattern such as a passivation film, a buffer coat film, and an interlayer insulating film in a semiconductor package, and (4). A photosensitive polyimide pattern can be produced by a method including a step of heat-treating the photosensitive polyimide pattern to complete it as a permanent insulating film.

Hereinafter, typical embodiments of each step will be described.
(1) A step of forming a resin layer on a substrate by applying a photosensitive resin composition on the substrate:
In this step, the photosensitive resin composition of the present invention is applied onto a substrate such as a silicon wafer, a metal substrate, a ceramic substrate, or an organic substrate, and if necessary, dried thereafter to form a resin layer. As a coating method, a method conventionally used for coating a photosensitive resin composition, for example, a method of coating with a spin coater, a bar coater, a blade coater, a curtain coater, a screen printing machine, or the like, or spray coating with a spray coater. A method or the like can be used.

If necessary, the coating film made of the photosensitive resin composition can be dried. As the drying method, methods such as air drying, heat drying using an oven or a hot plate, and vacuum drying are used. Specifically, when air-drying or heat-drying is performed, drying can be performed at 20 to 140 ° C. for 1 to 30 minutes. It is not limited to this range as long as it does not inhibit various properties of the photosensitive resin composition of the present invention.

(2) Step of exposing the resin layer:
In this step, the resin layer formed in the above step (1) is exposed with an exposure device such as a contact aligner, a mirror projection, a stepper, etc., through a photomask or reticle having a pattern, or directly with an ultraviolet light source or the like. To do. After that, for the purpose of improving the light sensitivity and the like, post-exposure baking and / or pre-development baking may be performed at an arbitrary combination of temperature and time, if necessary. The range of the baking conditions is preferably 40 to 120 ° C. and 10 to 240 seconds, but is not limited to this range as long as it does not inhibit various properties of the photosensitive resin composition of the present invention.

(3) Step of developing the resin layer after exposure to form a photosensitive polyimide pattern:
In this step, the unexposed portion of the photosensitive resin layer after exposure is developed and removed. As the developing method, any method can be selected and used from conventionally known photoresist developing methods such as a rotary spray method, a paddle method, and a dipping method accompanied by ultrasonic treatment. Further, after development, post-development baking may be performed at an arbitrary combination of temperature and time, if necessary, for the purpose of adjusting the shape of the photosensitive polyimide pattern.

As the developing solution used for development, a good solvent for the photosensitive resin composition or a combination of the good solvent and a poor solvent is preferable. For example, as a good solvent, N-methylpyrrolidone, N-cyclohexyl-2-pyrrolidone, N, N-dimethylacetamide, cyclopentanone, cyclohexanone, γ-butyrolactone, α-acetyl-γ-butyrolactone and the like are preferable. As the poor solvent, toluene, xylene, methanol, ethanol, isopropyl alcohol, ethyl lactate, propylene glycol methyl ether acetate and the like are preferable. When a good solvent and a poor solvent are mixed and used, it is preferable to adjust the ratio of the poor solvent to the good solvent by the solubility of the polymer in the photosensitive resin composition. Further, for each of the good solvent and the poor solvent, two or more kinds of solvents, for example, several kinds can be used in combination.

(4) A step of heat-treating the photosensitive polyimide pattern to complete it as a permanent insulating film:
In this step, the photosensitive polyimide pattern obtained by the above development is heated to complete it as a permanent insulating film. That is, unlike the polyamic acid type, since imidization has already been completed, it can be completed as a permanent insulating film by removing residues such as a solvent. As a method of heat curing, various methods such as a hot plate method, an oven method, and a temperature rise type oven in which a temperature program can be set can be selected. The heating is a sufficient condition for evaporating the contained solvent and the like, and can be performed, for example, at 150 to 250 ° C. for about 30 minutes to 2 hours. Air may be used as the atmospheric gas during heating, or an inert gas such as nitrogen or argon may be used.

The photosensitive polyimide pattern formed as described above can be used as an interlayer insulating film, a passivation film or a surface protective film of a semiconductor package, an electronic element, a display element or an organic multilayer wiring board.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited thereto.

(Synthesis of block copolymer polyimide)
Synthesis Example 1
A glass separable three-necked flask was fitted with a stirrer, a nitrogen introduction tube, and a cooling tube equipped with a water receptor. 3,4,3', 4'-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA) 64.45 g (0.2 mol), 1,3-bis (3-aminophenoxy) benzene 29.23 g (0) .1 mol), 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene were charged, and after stirring at room temperature in a nitrogen atmosphere at 200 rpm for 30 minutes. The temperature was raised to 180 ° C., and the mixture was heated and stirred for 1 hour. During the reaction, the toluene-water azeotropic component was removed.
After cooling to room temperature, BTDA 48.33 g (0.15 mol), 2,4-diethyl-6-methyl-1,3-benzenediamine 44.57 g (0.25 mol) (N-alkyl group at the ortho position) (Aromatic diamine having), NMP 360 g, and toluene 90 g were added, and the mixture was stirred at room temperature for 30 minutes, then heated to 180 ° C. and heated and stirred for 1 hour. The reaction was completed by heating and stirring at 180 ° C. for 2 hours and 30 minutes while removing the reflux product of water-toluene azeotrope from the system. NMP was added to the obtained product and diluted to obtain a block copolymer polyimide solution having a solid content of 20% by weight.

Synthesis Example 2
A glass separable three-necked flask was fitted with a stirrer, a nitrogen introduction tube, and a cooling tube equipped with a water receptor. 3,4,3', 4'-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA) 64.45 g (0.2 mol), 1,3-bis (3-aminophenoxy) benzene 29.23 g (0. 1 mol), 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene were charged, stirred at room temperature in a nitrogen atmosphere at 200 rpm for 30 minutes, and then 180. The temperature was raised to ° C., and the mixture was heated and stirred for 1 hour. During the reaction, the toluene-water azeotropic component was removed.
After cooling to room temperature, BTDA 48.33 g (0.15 mol), 5,7-diamino-1,1,4,6-tetramethylindan 51.08 g (0.25 mol) (alkyl at the ortho position with respect to N-) Aromatic diamine having a group), 360 g of NMP, and 90 g of toluene were added, and the mixture was stirred at room temperature for 30 minutes, then heated to 180 ° C. and heated and stirred for 1 hour. The reaction was completed by heating and stirring at 180 ° C. for 2 hours and 30 minutes while removing the reflux product of water-toluene azeotrope from the system. NMP was added to the obtained product and diluted to obtain a block copolymer polyimide solution having a solid content of 20% by weight.

Synthesis Example 3
A glass separable three-necked flask was fitted with a stirrer, a nitrogen introduction tube, and a cooling tube equipped with a water receptor. 3,4,3', 4'-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA) 64.45 g (0.2 mol), 1,3-bis (3-aminophenoxy) benzene 29.23 g (0. 1 mol), 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene were charged, stirred at room temperature in a nitrogen atmosphere at 200 rpm for 30 minutes, and then 180. The temperature was raised to ° C., and the mixture was heated and stirred for 1 hour. During the reaction, the toluene-water azeotropic component was removed.
After cooling to room temperature, 44.13 g (0.15 mol) of 3,4,3', 4'-biphenyltetracarboxylic dianhydride, 2,4-diethyl-6-methyl-1,3-benzenediamine 44. 57 g (0.25 mol) (aromatic diamine having an alkyl group at the ortho position with respect to N-), 360 g of NMP, and 90 g of toluene were added, stirred at room temperature for 30 minutes, then heated to 180 ° C. and heated for 1 hour. Stirred. The reaction was completed by heating and stirring at 180 ° C. for 2 hours and 30 minutes while removing the reflux product of water-toluene azeotrope from the system. NMP was added to the obtained product and diluted to obtain a block copolymer polyimide solution having a solid content of 20% by weight.

Synthesis Example 4
A glass separable three-necked flask was fitted with a stirrer, a nitrogen introduction tube, and a cooling tube equipped with a water receptor. 3,4,3', 4'-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA) 64.45 g (0.2 mol), 5-amino-1- (4'-aminophenyl) -1,3 2-trimethylindane 26.64 g (0.1 mol) (phenylindane structure-containing aromatic diamine), valerolactone 1.5 g (0.015 mol), pyridine 2.4 g (0.03 mol), NMP 200 g, toluene 30 g Was charged, and the mixture was stirred at 200 rpm for 30 minutes at room temperature under a nitrogen atmosphere, then heated to 180 ° C. and heated and stirred for 1 hour. During the reaction, the toluene-water azeotropic component was removed.
After cooling to room temperature, BTDA 48.33 g (0.15 mol), 5-amino-1- (4'-aminophenyl) -1,3,3-trimethylindan 66,60 g (0.25 mol), NMP360 g, toluene After adding 90 g and stirring at room temperature for 30 minutes, the temperature was raised to 180 ° C., and the mixture was heated and stirred for 1 hour. The reaction was completed by heating and stirring at 180 ° C. for 2 hours and 30 minutes while removing the reflux product of water-toluene azeotrope from the system. NMP was added to the obtained product and diluted to obtain a block copolymer polyimide solution having a solid content of 20% by weight.

Synthesis Example 5
A glass separable three-necked flask was fitted with a stirrer, a nitrogen introduction tube, and a cooling tube equipped with a water receptor. 3,4,3', 4'-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA) 64.45 g (0.2 mol), 2,4-diaminotoluene 12.22 g (0.1 mol) (N- Aromatic diamine having an alkyl group at the ortho position), 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene were charged at room temperature under a nitrogen atmosphere. After stirring at 200 rpm for 30 minutes, the temperature was raised to 180 ° C. and the mixture was heated and stirred for 1 hour. During the reaction, the toluene-water azeotropic component was removed.
After cooling to room temperature, BTDA 48.33 g (0.15 mol), 5-amino-1- (4'-aminophenyl) -1,3,3-trimethylindan 66.60 g (0.25 mol), NMP360 g, toluene After adding 90 g and stirring at room temperature for 30 minutes, the temperature was raised to 180 ° C., and the mixture was heated and stirred for 1 hour. The reaction was completed by heating and stirring at 180 ° C. for 2 hours and 30 minutes while removing the reflux product of water-toluene azeotrope from the system. NMP was added to the obtained product and diluted to obtain a block copolymer polyimide solution having a solid content of 20% by weight.

Synthesis Example 6
A glass separable three-necked flask was fitted with a stirrer, a nitrogen introduction tube, and a cooling tube equipped with a water receptor. 3,4,3', 4'-benzophenone tetracarboxylic acid dianhydride (hereinafter referred to as BTDA) 64.45 g (0.2 mol), 5-amino-1- (4'-aminophenyl) -1,3 3-trimethylindan 15.98 g (0.06 mol), 1,3-bis (3-aminopropyl) tetramethyldisiloxane 9.94 g (0.04 mol), Valerolactone 1.5 g (0.015 mol) , 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene were charged, and the mixture was stirred at room temperature for 30 minutes, then heated to 180 ° C. and stirred for 1 hour. During the reaction, the toluene-water azeotropic component was removed.
After cooling to room temperature, BTDA 48.33 g (0.15 mol), 5-amino-1- (4'-aminophenyl) -1,3,3-trimethylindan 66.60 g (0.25 mol), NMP360 g, toluene After adding 90 g and stirring at room temperature for 30 minutes, the temperature was raised to 180 ° C., and the mixture was heated and stirred for 1 hour. The reaction was completed by heating and stirring at 180 ° C. for 2 hours and 30 minutes while removing the reflux product of water-toluene azeotrope from the system. NMP was added to the obtained product and diluted to obtain a block copolymer polyimide solution having a solid content of 20% by weight.

Synthesis comparison example 1
A glass separable three-necked flask was fitted with a stirrer, a nitrogen introduction tube, and a cooling tube equipped with a water receptor. 58.84 g (0.2 mol) of 3,4,3', 4'-biphenyltetracarboxylic dianhydride,
29.23 g (0.1 mol) of 1,3-bis (3-aminophenoxy) benzene, 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene. After charging, the mixture was stirred at 200 rpm for 30 minutes at room temperature in a nitrogen atmosphere, then heated to 180 ° C. and heated and stirred for 1 hour. During the reaction, the toluene-water azeotropic component was removed.
After cooling to room temperature, 48.33 g (0.15 mol) of 3,4,3', 4'-benzophenonetetracarboxylic dianhydride, 2,4-diethyl-6-methyl-1,3-benzenediamine 44. 57 g (0.25 mol) (aromatic diamine having an alkyl group at the ortho position with respect to N-), 360 g of NMP, and 90 g of toluene were added, stirred at room temperature for 30 minutes, then heated to 180 ° C. and heated for 1 hour. Stirred. The reaction was completed by heating and stirring at 180 ° C. for 2 hours and 30 minutes while removing the reflux product of water-toluene azeotrope from the system. NMP was added to the obtained product and diluted to obtain a block copolymer polyimide solution having a solid content of 20% by weight.

Synthesis comparison example 2
A glass separable three-necked flask was fitted with a stirrer, a nitrogen introduction tube, and a cooling tube equipped with a water receptor. 3,4,3', 4'-benzophenonetetracarboxylic dianhydride (hereinafter referred to as BTDA) 64.45 g (0.2 mol), 2,4-diaminotoluene 12.22 g (0.1 mol) (N- Aromatic diamine having an alkyl group at the ortho position), 1.5 g (0.015 mol) of valerolactone, 2.4 g (0.03 mol) of pyridine, 200 g of NMP, and 30 g of toluene were charged at room temperature under a nitrogen atmosphere. After stirring at 200 rpm for 30 minutes, the temperature was raised to 180 ° C. and the mixture was heated and stirred for 1 hour. During the reaction, the toluene-water azeotropic component was removed.
After air cooling, 48.33 g (0.15 mol) of BTDA, 73.08 g (0.25 mol) of 1,3-bis (3-aminophenoxy) benzene (aromatic diamine containing aromatic ether bond), 360 g of NMP, and 90 g of toluene were added. In addition, after stirring at room temperature for 30 minutes, the temperature was raised to 180 ° C., and the mixture was heated and stirred for 1 hour. The reaction was completed by heating and stirring at 180 ° C. for 2 hours and 30 minutes while removing the reflux product of water-toluene azeotrope from the system. NMP was added to the obtained product and diluted to obtain a block copolymer polyimide solution having a solid content of 20% by weight.

(Preparation of photosensitive polyimide resin composition)
In the following examples and comparative examples, "part" means "part by weight".
Examples 1 to 6
Synthesis In 500 parts of the block copolymer polyimide solution (solid content 20% by weight) of Examples 1 to 6, 20 parts of 2,6-di (4'-azidobenzal) -4-ethylcyclohexanone, 9,10-dibutoxyanthracene 1 Part, 3-glycidoxypropylmethyldimethoxysilane 1 part, 5-methyl-1H-benzotrial 0.1 part, 1,3,5-tris (4-triethylmethyl-3-hydroxy-2,6-dimethyl) Benzyl) -1,3,5-triazine-2,4,6- (1H, 3H, 5H) -trione was added and dissolved in methyl benzoate to prepare a photosensitive resin composition having a solid content of 20%. ..

Example 7
In Example 1 (using the polyimide solution of Synthesis Example 1), 2,6-di (4'-azidobenzal) -4-methyl instead of 2,6-di (4'-azidobenzal) -4-ethylcyclohexanone. A photosensitive resin composition was prepared using the same method except that cyclohexanone was used.

Example 8
Except that 4,4'-diazidobenzalacetophenone was used instead of 2,6-di (4'-azidobenzal) -4-ethylcyclohexanone in Example 1 (using the polyimide solution of Synthesis Example 1). Prepared a photosensitive resin composition using the same method.

Example 9
In Example 1 (using the polyimide solution of Synthesis Example 1), 16.7 parts of YX-6954BH30 (polymer epoxy; manufactured by Mitsubishi Chemical Industries, Ltd.), WPBG-300 (photobase generator: Fuji Film Wako Pure Chemical Industries, Ltd.) A photosensitive resin composition was prepared using the same method except that 0.25 parts were added.

Example 10
In Example 1 (using the polyimide solution of Synthesis Example 1), 5 parts of TEPIC-VL (trifunctional epoxy: manufactured by Nissan Chemical Industries, Ltd.) and WPBG-300 (photobase generator: manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.) ) A photosensitive resin composition was prepared using the same method except that 0.25 parts were added.

Comparative Example 1
In Example 7 (using the polyimide solution of Synthesis Example 1), the photosensitive resin composition was prepared by using the same method except that 2,6-di (4'-azidobenzal) -4-methylcyclohexanone was not used. Was prepared.

Comparative Example 2
The same method except that in Example 7 (using the polyimide solution of Synthesis Example 1), 1.5 parts of 2,6-di (4'-azidobenzal) -4-methylcyclohexanone was used instead of 20 parts. A photosensitive resin composition was prepared using.

(Performance evaluation of polyimide resin composition)
1. 1. Mechanical strength, coefficient of thermal expansion and 5% thermal weight reduction temperature The resin compositions obtained in Examples 1 to 10 and Comparative Examples 1 and 2 were put on a 6-inch silicon wafer and the film thickness after final drying was 15 to 17 μm. After spin-coating and pre-baking at 90 ° C. for 360 seconds, a high-pressure mercury lamp was used to perform 2,500 mJ / cm ² full-wavelength exposure in terms of i-ray, and then immersed in a cyclopentanone solution for 120 seconds. , 200 ° C. (or 180 ° C.) for 90 minutes to prepare a dried resin film.
This dry resin film was peeled off from the wafer with hydrofluoric acid to prepare a test sample for measuring mechanical strength, coefficient of thermal expansion and 5% thermogravimetric reduction temperature.

2. 2. Adhesion strength A dry resin film formed on the silicon wafer produced above is used.
(1) Using a utility knife on the test surface, make 11 cuts that reach the substrate and make 100 grids. Use a cutter guide and set the cut spacing to 1 mm.
(2) Scotch tape (registered trademark) is strongly crimped to the grid portion, the end of the tape is peeled off at a stretch at an angle of 45 °, and the state of the grid is evaluated by comparing with the standard drawing. The adhesion strength after 240 hours in the normal state and HAST (80 ° C. × 85% RH) is determined.

3. 3. Residual film ratio The resin compositions obtained in Examples 1 to 10 and Comparative Examples 1 and 2 were spin-coated on a 6-inch silicon wafer so that the film thickness after final drying was 5 to 7 μm and 10 to 12 μm. After prebaking at 90 ° C. for 240 seconds and 90 ° C. for 300 seconds, the thickness (t ₁ ) is measured with a film thickness meter. Next, using a high-pressure mercury lamp, 1,000 (or 2,500) mJ / cm ² full-wavelength exposure was performed in terms of i-line, and after immersing in a cyclopentanone solution for 120 seconds, the thickness (t ₂ ) was measured with a film thickness meter. ) Is measured. Further, heat drying is performed at 200 ° C. (or 180 ° C.) for 90 minutes, and then the thickness (t ₃ ) is measured with a film thickness meter. From these measured values, t ₂ / t _1, t ₃ / t ₁ and t ₃ / t ₂ were calculated and used as the residual film ratio.

4. Exposure / developability The pattern evaluation was performed by the following method.
(1) Resolution The resin compositions obtained in Examples 1 to 10 and Comparative Examples 1 and 2 were dropped onto a 6-inch silicon wafer, spun-coated for 30 seconds, and then prebaked on a hot plate at 90 ° C. for 240 seconds. did. At this time, the coating rotation was adjusted so that the film thickness after baking was about 6 to 8 μm. Then, it was exposed using a high-pressure mercury lamp. The exposure amount measured by i-line was 1,000 mJ / cm ² . Then, it was developed with cyclopentanone, then rinsed and then heated and dried at 200 ° C. (or 180 ° C.) for 90 minutes. L / S = 5/5, 10/10, 15/15, 20/20, 30/30, 50/50 μm, square via hole pattern 10, 15, 20, 30, 40, 50 μm, the smallest resolution Was taken as the resolution.

(2) Pattern edge residue and cracks Pattern processing was performed in the same manner as in (1) above, and first, it was visually observed whether or not there was any abnormality on the film surface after development. Next, a 15 μm square via hole pattern was observed with an optical microscope, and the case where the corner of the pattern was cracked was regarded as cracked. Further, the pattern edge of L / S = 15/15 was observed, and the case where the development residue was generated was regarded as having a residue.

The evaluation results of the resin compositions obtained in Examples 1 to 10 and Comparative Examples 1 and 2 are shown in Tables 1 and 2 below. In the evaluation of the residual film ratio and the exposure developability of the resin compositions obtained in Comparative Examples 1 and 2, the film was dissolved when immersed in a cyclopentanone solution after exposure. This result indicates that the resin compositions obtained in Comparative Examples 1 and 2 did not have good solvent insolubility after photocrosslinking. Therefore, the Tg, coefficient of thermal expansion, 5% thermogravimetric reduction temperature, mechanical strength, and adhesion strength of the resin composition obtained in Comparative Examples 1 and 2 are such that the sample is prepared without immersing the resin composition in the cyclopentanone solution. It was prepared and evaluated. On the other hand, it can be seen that the resin compositions obtained in Examples 1 to 10 have both solvent solubility during development and solvent insolubility after photocrosslinking, and have achieved good film physical properties and high sensitivity.

The negative photosensitive polyimide resin composition of the present invention includes, for example, semiconductor packages such as FO-WLP and WLP, electronic elements such as thin film magnetic heads, thin film inductors, thin film magnetic elements such as common mode choke coils, and TFT liquid crystal elements. It is useful for manufacturing display elements such as color filter elements and organic EL elements, and organic multilayer wiring substrates, and can be suitably used in the field of photosensitive materials.

Claims

A photosensitive polyimide resin composition containing (A) a solvent-soluble polyimide and (B) a diazide compound as essential components.
The solvent-soluble polyimide (A) has (a) an aromatic tetracarboxylic acid dianhydride residue having a benzophenone structure, (b) an aromatic diamine having an alkyl group at the ortho position of the amino group, and an aromatic having an indan structure. A block copolymer having at least one diamine residue selected from the group consisting of group diamines and diamines having a polysiloxane structure in the main chain.
A photosensitive polyimide resin composition in which the content of the (B) diazide compound is 2.0 to 150 parts by weight with respect to 100 parts by weight of the solvent-soluble polyimide (A).
The resin composition according to claim 1, wherein the residue of at least one of the diamines is a residue of an aromatic diamine having a phenylindane structure.
The resin composition according to claim 1 or 2, wherein the diazide compound (B) is 2,6-di (4'-azidobenzal) -4-ethylcyclohexanone.
The resin composition according to any one of claims 1 to 3, wherein the photosensitive polyimide resin composition further contains (C) an epoxy resin and (D) a photobase generator.
The resin composition according to any one of claims 1 to 4, wherein the photosensitive polyimide resin composition is a negative solvent developing composition.
A pattern forming method characterized in that a substrate coated with the resin composition according to any one of claims 1 to 5 is exposed to ultraviolet irradiation, and an unexposed portion is developed and removed.
A semiconductor package, an electronic element, a display element or an organic multilayer wiring board having an interlayer insulating film, a passivation film or a surface protective film formed by using the resin composition according to any one of claims 1 to 5.