KR102457058B1 - Curable resin composition, laminate structure, cured product thereof, and electronic component - Google Patents

Abstract

[Problem] To provide a curable resin composition that satisfies the required performance of both a solder resist and a coverlay, is excellent in heat resistance and low repulsion properties without impairing developability, and exhibits small warpage after heating. Moreover, the curable resin composition which satisfy|fills the required performance of both a soldering resist and a coverlay, and is excellent in developability (alkali solubility) and heat resistance (solder heat resistance) is provided.
[Solution means] It is an alkali-soluble polyimide resin, alkali-soluble resin other than this polyimide resin, and curable resin composition containing a sclerosing|hardenable compound.

Description

Curable resin composition, laminated structure, cured product thereof, and electronic component {CURABLE RESIN COMPOSITION, LAMINATE STRUCTURE, CURED PRODUCT THEREOF, AND ELECTRONIC COMPONENT}

The present invention relates to a curable resin composition useful as an insulating film for electronic components such as flexible printed wiring boards (hereinafter simply referred to as “composition”), a laminated structure, a cured product thereof, and an electronic component.

In recent years, small space reduction of electronic components, such as a circuit board, is required with the miniaturization and thinning of the electronic device by the spread of smart phones and tablet terminals. Therefore, the use of the flexible printed wiring board which can bend and accommodate is expanded, and it is calculated|required also about a flexible printed wiring board to have reliability higher than ever before.

In contrast, at present, as an insulating film for securing the insulation reliability of a flexible printed wiring board, a polyimide-based coverlay excellent in mechanical properties such as heat resistance and flexibility is used for the bent portion (bent portion) (for example, A mixed process using the photosensitive resin composition which is excellent in electrical insulation, solder heat resistance, etc. and which microfabrication is possible is widely employ|adopted for a mounting part (refer patent documents 1 and 2) and a mounting part (non-bending part).

That is, since a polyimide-based coverlay requires processing by die punching, it is unsuitable for fine wiring. Therefore, it was necessary to use together the photosensitive resin composition (solder resist) of the alkali development type in which the process by photolithography is possible partially for the chip mounting part which requires fine wiring.

Japanese Patent Laid-Open No. 62-263692 Japanese Patent Laid-Open No. 63-110224

Thus, in the manufacturing process of the conventional flexible printed wiring board, the mixed process of the process of facing a cover-lay, and the process of forming a soldering resist had to be employ|adopted, and there existed a problem that cost and workability were inferior.

On the other hand, applying the insulating film as an insulating film as a soldering resist or an insulating film as a coverlay as a soldering resist and a coverlay of a flexible printed wiring board has been studied, but with respect to the request|requirement of small space-ization of a circuit board, both a soldering resist and a coverlay. Materials that can sufficiently satisfy the required performance of

In addition, various properties are required for solder resists and coverlays, such as excellent developability (alkali solubility), heat resistance (solder heat resistance), low repulsion (spring resistance), and small warpage after heating (warpage after curing). do. However, when an alkali-soluble resin having a large molecular weight is used in order to improve low repulsion properties and warpability after heating while ensuring heat resistance, there arises a problem that development cannot be performed. Moreover, although an imide-type resin has heat resistance, there exists a difficulty that the curvature after hardening is large, and a urethane-type resin has a problem that heat resistance is bad although it is low repulsion and low warpage. Therefore, in the composition using various resins proposed conventionally, it was not able to satisfy|fill all the request|requirements that developability was not impaired, it was excellent in heat resistance and low repulsion property, and the curvature after heating was small.

Then, the main object of this invention is to provide the curable resin composition which satisfy|fills the required performance of both a soldering resist and a coverlay, and is excellent in heat resistance and low repulsion property without impairing developability, and curvature after heating small. .

In addition, another object of the present invention is a curable resin composition suitable for a batch formation process of an insulating film such as a flexible printed wiring board, particularly a bent portion (bent portion) and a mounting portion (non-bent portion), a laminated structure, a cured product thereof, and a cured product thereof For example, it is providing electronic components, such as a flexible printed wiring board which has as protective layers, such as a coverlay or a soldering resist.

MEANS TO SOLVE THE PROBLEM The present inventors came to complete this invention which makes the following content as a summary structure, as a result of earnestly examining in order to solve the said subject.

That is, curable resin composition of this invention contains alkali-soluble polyimide resin, alkali-soluble resin other than this polyimide resin, and a sclerosing|hardenable compound is contained, It is characterized by the above-mentioned.

In the curable resin composition of the present invention, it is preferable that the alkali-soluble resin other than the polyimide resin is a polyamideimide resin, and the polyamideimide resin has a structure represented by the following general formula (1) and the following general formula ( It is preferable that it is a polyamideimide resin which has the structure represented by 2).

(X ₁ is a residue of an aliphatic diamine (a) derived from a dimer acid having 24 to 48 carbon atoms, X ₂ is a residue of an aromatic diamine (b) having a carboxyl group, and Y is each independently a cyclohexane ring or an aromatic ring)

Moreover, it is preferable that curable resin composition of this invention contains a core-shell rubber particle further. Moreover, in curable resin composition of this invention, it is preferable that the said polyimide resin has a carboxyl group, and it is more preferable that it has a carboxyl group and phenolic hydroxyl group.

Moreover, in curable resin composition of this invention, it is preferable that the said sclerosing|hardenable compound is an epoxy resin.

Moreover, the laminated structure of this invention is a laminated structure which has a resin layer (A) and a resin layer (B) laminated|stacked on a base material through this resin layer (A),

The resin layer (B) contains the curable resin composition, and the resin layer (A) contains an alkali-developable resin composition containing an alkali-soluble resin and a heat-reactive compound.

Moreover, the hardened|cured material of this invention contains the said curable resin composition or the said laminated structure, It is characterized by the above-mentioned.

Moreover, the electronic component of this invention has the insulating film containing the said hardened|cured material, It is characterized by the above-mentioned.

Here, as an electronic component of this invention, for example, the layer of the said laminated structure is formed on a flexible printed wiring board, patterning by light irradiation, and what has an insulating film formed by collectively forming a pattern with a developing solution is mentioned. In addition, without using the laminated structure, the resin layer (A) and the resin layer (B) are sequentially formed on a flexible printed wiring board, and then patterned by light irradiation, and the pattern is collectively formed with a developer. It may have an insulating film. In the present invention, the term “pattern” refers to a pattern-shaped cured product, that is, an insulating film.

ADVANTAGE OF THE INVENTION According to this invention, it can satisfy|fill the required performance of both a soldering resist and a coverlay, and is excellent in heat resistance and low repulsion property without impairing developability, and can provide the curable resin composition with small curvature after heating. In addition, a curable resin composition suitable for a batch formation process of an insulating film of an electronic component such as a flexible printed wiring board, particularly a bent portion (bent portion) and a mounting portion (non-bend portion), a laminated structure, a cured product thereof, and a cured product thereof, for example It became possible to implement|achieve electronic components, such as a flexible printed wiring board which has as a protective film, such as a coverlay or a soldering resist.

1 : is process drawing which shows typically the manufacturing method of the flexible printed wiring board which shows an example of the electronic component of this invention.
2 : is process drawing which shows typically another example of the manufacturing method of the flexible printed wiring board which shows an example of the electronic component of this invention.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail.

(Curable resin composition)

The curable resin composition of this invention contains alkali-soluble polyimide resin, alkali-soluble resin other than that, and a sclerosing|hardenable compound.

By containing alkali-soluble polyimide resin, other alkali-soluble resin, and a sclerosing|hardenable compound, the required performance of both a soldering resist and a coverlay is satisfied, and the curable resin composition excellent in developability and heat resistance can be implement|achieved.

(Alkali-soluble polyimide resin)

As alkali-soluble polyimide resin, what is necessary is just what contains 1 or more types of functional groups among a phenolic hydroxyl group and a carboxyl group, and can develop with an alkali solution, and a well-known and usual thing is used.

According to this polyimide resin, characteristics, such as bending resistance and heat resistance, become more excellent.

Resin obtained by making such alkali-soluble polyimide resin make a carboxylic anhydride component, an amine component, and/or an isocyanate component react is mentioned, for example. Here, an alkali-soluble group is introduce|transduced by using the amine component which has a carboxyl group or a phenolic hydroxyl group. In addition, imidation may be performed by thermal imidation, and may be performed by chemical imidation, and can also be performed by using these together.

Examples of the carboxylic acid anhydride component include tetracarboxylic anhydride and tricarboxylic acid anhydride. It can be used including derivatives. In addition, you may use these carboxylic acid anhydride components individually or in combination.

As an amine component, diamines, such as an aliphatic diamine and aromatic diamine, polyhydric amines, such as an aliphatic polyetheramine, the diamine which has a carboxyl group, the diamine which has a phenolic hydroxyl group, etc. can be used. Although it is not limited to these amines as an amine component, It is necessary to use the amine which can introduce|transduce at least 1 type of functional group among a phenolic hydroxyl group and a carboxyl group. In addition, you may use these amine components individually or in combination.

As the isocyanate component, diisocyanates such as aromatic diisocyanate, isomers and multimers thereof, aliphatic diisocyanates, alicyclic diisocyanates and isomers thereof, and other general-purpose diisocyanates can be used. not. In addition, you may use these isocyanate components individually or in combination.

In the synthesis|combination of such alkali-soluble polyimide resin, a well-known and usual organic solvent can be used. As such an organic solvent, if it is a solvent which does not react with the carboxylic acid anhydrides, amines, and isocyanates which are raw materials, and these raw materials melt|dissolve, there will be no problem, and the structure in particular is not limited. In particular, since the solubility of the raw material is high, aprotic properties such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, dimethylsulfoxide, and γ-butyrolactone Solvents are preferred.

The alkali-soluble polyimide resin as described above has a good balance between the alkali solubility (developability) of the polyimide resin and other properties such as mechanical properties of a cured product of a resin composition containing the polyimide resin, from the viewpoint of its It is preferable that an acid value (solid content acid value) is 20-200 mgKOH/g, It is preferable that it is 60-150 mgKOH/g more suitably. Specifically, by making this acid value into 20 mgKOH/g or more, alkali solubility, ie, developability, becomes favorable, and also the crosslinking density with the thermosetting component after light irradiation becomes high, and sufficient image development contrast can be obtained. Further, by setting the acid value to 200 mgKOH/g or less, it is possible to suppress so-called thermal fogging in the PEB (POST EXPOSURE BAKE) process after light irradiation, which will be described later, particularly, and the process margin is increased.

Further, the molecular weight of the alkali-soluble polyimide resin, in consideration of developability and cured coating film properties, preferably has a mass average molecular weight Mw of 100,000 or less, more preferably 1,000 to 100,000, and still more preferably 2,000 to 50,000. Alkali solubility of an unexposed part increases that this molecular weight is 100,000 or less, and developability improves. On the other hand, when the molecular weight is 1,000 or more, sufficient develop resistance and cured properties can be obtained in the exposed portion after the exposure/PEB process.

(Alkali-soluble resins other than polyimide resins)

As such alkali-soluble resin, what is necessary is just to contain one or more types of functional groups among a phenolic hydroxyl group and a carboxyl group, and to develop with an alkali solution, and a well-known and usual thing is used. For example, carboxyl group-containing resin or carboxyl group-containing photosensitive resin conventionally used for a soldering resist can be used.

In particular, alkali-soluble polyamideimide resin can be suitably used from a viewpoint of obtaining a resin composition which is more excellent in characteristics, such as bending resistance and heat resistance, without impairing developability.

By using this alkali-soluble polyamide-imide resin together with the alkali-soluble polyimide resin described above, it is possible to provide a curable resin composition that does not impair developability, has excellent heat resistance and low repulsion, and has a low dielectric and small warpage after heating. can

Here, as a compounding ratio of this alkali-soluble polyamide-imide resin and the alkali-soluble polyimide resin mentioned above, it can be 98:2-50:50 by mass ratio, and it is preferable to set it as 90:10-50:50. .

(Alkali-soluble polyamideimide resin)

Curable resin composition of this invention WHEREIN: As an alkali-soluble polyamideimide resin, any thing which contains at least 1 type of functional group among a phenolic hydroxyl group and a carboxyl group, and can develop with an alkali solution, a well-known and usual thing is used.

Examples of such alkali-soluble polyamideimide resin include a resin obtained by reacting a carboxylic acid anhydride component with an amine component to obtain an imidized product, and then reacting the obtained imidized product with an isocyanate component. Here, an alkali-soluble group is introduce|transduced by using the amine component which has a carboxyl group or a phenolic hydroxyl group. In addition, imidation may be performed by thermal imidation, and may be performed by chemical imidation, and can also be performed by using these together.

Examples of the carboxylic acid anhydride component include tetracarboxylic anhydride and tricarboxylic acid anhydride. It can be used including derivatives. In addition, you may use these carboxylic acid anhydride components individually or in combination.

As an amine component, diamines, such as an aliphatic diamine and aromatic diamine, polyhydric amines, such as an aliphatic polyetheramine, the diamine which has a carboxyl group, the diamine which has a phenolic hydroxyl group, etc. can be used. Although it is not limited to these amines as an amine component, It is necessary to use the amine which can introduce|transduce at least 1 type of functional group among a phenolic hydroxyl group and a carboxyl group. In addition, you may use these amine components individually or in combination.

As the isocyanate component, diisocyanates such as aromatic diisocyanate, isomers and multimers thereof, aliphatic diisocyanates, alicyclic diisocyanates and isomers thereof, and other general-purpose diisocyanates can be used. not. In addition, you may use these isocyanate components individually or in combination.

The alkali-soluble polyamide-imide resin as described above has a good balance between the alkali solubility (developability) of the polyamide-imide resin and other properties such as mechanical properties of a cured product of a resin composition containing the polyamide-imide resin. The acid value (solid content acid value) is preferably 30 mgKOH/g or more, more preferably 30 mgKOH/g to 150 mgKOH/g, and particularly preferably 50 mgKOH/g to 120 mgKOH/g. Specifically, by making this acid value into 30 mgKOH/g or more, alkali solubility, ie, developability, becomes favorable, and also the crosslinking density with the thermosetting component after light irradiation becomes high, and sufficient image development contrast can be obtained. In addition, by setting the acid value to 150 mgKOH/g or less, so-called thermal fogging in the PEB (POST EXPOSURE BAKE) process after light irradiation, which will be described later, can be suppressed, and the process margin is increased.

Further, the molecular weight of the alkali-soluble polyamideimide resin is preferably 20,000 or less, more preferably 1,000 to 15,000, and still more preferably 2,000 to 10,000, in consideration of developability and cured coating film properties. Alkali solubility of an unexposed part increases that molecular weight is 20,000 or less, and developability improves. On the other hand, when the molecular weight is 1,000 or more, sufficient develop resistance and cured properties can be obtained in the exposed portion after the exposure/PEB process.

In particular, in the present invention, it is more preferable to use a polyamideimide resin having a structure represented by the following general formula (1) and a structure represented by the following general formula (2) from the viewpoint of further improving developability.

Here, X ₁ is a residue of an aliphatic diamine (a) derived from a dimer acid having 24 to 48 carbon atoms (also referred to as “dimer diamine (a)” in this specification). X ₂ is a residue of an aromatic diamine (b) having a carboxyl group (also referred to as “a carboxyl group-containing diamine (b)” in this specification). Y is each independently a cyclohexane ring or an aromatic ring.

By including the structure represented by the general formula (1) and the structure represented by the general formula (2), it is excellent in alkali solubility that can be dissolved even when a mild alkali solution such as a 1.0 mass % aqueous sodium carbonate solution is used. It can be set as polyamideimide resin. In addition, a cured product of the resin composition including the polyamideimide resin may have excellent dielectric properties.

Dimer diamine (a) can be obtained by reductive amination of the carboxyl group in the dimer of a C12-C24 aliphatic unsaturated carboxylic acid. That is, dimer diamine (a), which is an aliphatic diamine derived from dimer acid, is obtained by, for example, polymerizing unsaturated fatty acids such as oleic acid and linoleic acid to obtain dimer acid, reducing this and then aminating. As such an aliphatic diamine, commercial items, such as PRIAMINE1073, 1074, 1075 (the Croda Japan company make, brand name) which are diamine which have a C36 frame|skeleton, can be used, for example. The dimer diamine (a) may preferably be derived from a dimer acid having 28 to 44 carbon atoms, and more preferably be derived from a dimer acid having 32 to 40 carbon atoms.

Specific examples of the carboxyl group-containing diamine (b) include 3,5-diaminobenzoic acid, 3,4-diaminobenzoic acid, 5,5'-methylenebis(anthranilic acid), benzidine-3,3'-dicarboxylic acid, etc. can be heard The carboxyl group-containing diamine (b) may be comprised from one type of compound, and may be comprised from multiple types of compounds. From the viewpoint of raw material availability, the carboxyl group-containing diamine (b) preferably contains 3,5-diaminobenzoic acid and 5,5'-methylenebis(anthranilic acid).

The relationship between the content of the structure represented by the general formula (1) and the content of the structure represented by the general formula (2) in the polyamideimide resin is not limited. From the viewpoint of improving the balance between the alkali solubility of the polyamideimide resin and other properties such as mechanical properties of a cured product of a resin composition containing the polyamideimide resin, the content (unit: mass%) of the dimer diamine (a) is 20-60 mass % is preferable, and 30-50 mass % is more preferable. As used herein, the term "content of dimer diamine (a)" refers to the amount of the dimer diamine (a) placed as one of the raw materials at the time of manufacturing the polyamideimide resin, relative to the mass of the produced polyamideimide resin. means the ratio. Here, "mass of the produced polyamide-imide resin" is water (H ₂ O) generated in imidation and carbon dioxide gas (CO ₂ ) minus the theoretical quantity.

It is preferable that the part represented by Y in the said General formula (1) and said General formula (2) has a cyclohexane ring from a viewpoint of improving the alkali solubility of polyamideimide resin. From the viewpoint of improving the balance between the alkali solubility of the polyamideimide resin and other properties such as mechanical properties of a cured product of a resin composition containing the polyamideimide resin, the quantity of aromatic rings and cyclohexane rings in the portion represented by Y above As for the relationship, it is preferable that the molar ratio of content of a cyclohexane ring with respect to content of aromatic ring is 85/15-100/0, It is more preferable that it is 90/10-99/1, It is further more preferable that it is 90/10-98/2 desirable.

The polyamideimide resin may further have a partial structure represented by the following general formula (i).

Here, X ₃ is a residue of a diamine (f) other than the dimer diamine (a) and the carboxyl group-containing diamine (b) (herein, also referred to as “another diamine (f)”), Y is the general formula ( As in 1) and the said General formula (2), it is an aromatic ring or a cyclohexane ring each independently. Another diamine (f) may be comprised from one type of compound, and may be comprised from multiple types of compounds.

Specific examples of the other diamine (f) include 2,2-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(3-aminophenoxy)phenyl]sulfone, and bis[4-(4- Aminophenoxy)phenyl]sulfone, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, bis[4-(4-aminophenoxy)phenyl]methane, 4,4'- Bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ketone, 1,3-bis(4-amino Phenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 2,2'-dimethylbiphenyl-4,4'-diamine, 2,2'-bis(trifluoromethyl)biphenyl- 4,4'-diamine, 2,6,2',6'-tetramethyl-4,4'-diamine, 5,5'-dimethyl-2,2'-sulfonyl-biphenyl-4,4'- Diamine, 3,3'-dihydroxybiphenyl-4,4'-diamine, (4,4'-diamino)diphenyl ether, (4,4'-diamino)diphenylsulfone, (4,4 '-diamino)benzophenone, (3,3'-diamino)benzophenone, (4,4'-diamino)diphenylmethane, (4,4'-diamino)diphenylether, (3,3 and aromatic diamines such as '-diamino)diphenyl ether, and hexamethylenediamine, octamethylenediamine, decamethylenediamine, dodecamethylenediamine, octadecamethylenediamine, and 4,4'-methylenebis(cyclohexylamine). ), isophorone diamine, 1,4-cyclohexanediamine, and aliphatic diamines such as norbornene diamine.

The polyamideimide resin may have a structure represented by the following general formula (ii).

Here, Z may be an aliphatic group, and may also be contribution containing an aromatic. In the case of an aliphatic group, an alicyclic group such as a cyclohexane ring may be included. According to the manufacturing method mentioned later, Z becomes a residue of a diisocyanate compound (e).

The manufacturing method of the said polyamide-imide resin is not limited, It can manufacture through an imidation process and amidimidization process using a well-known and usual method.

In the imidation step, dimer diamine (a), carboxyl group-containing diamine (b), and cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (c) and trimellitic anhydride (d) 1 type or 2 types selected from the group which consists of are made to react, and an imidide is obtained.

The amount of the dimer diamine (a) to be charged is preferably 20 to 60% by mass, and more preferably 30 to 50% by mass of the dimer diamine (a). The definition of content of dimer diamine (a) is as above-mentioned.

As needed, you may use another diamine (f) with dimer diamine (a) and carboxyl group-containing diamine (b).

It is preferable to use the cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (c) in the imidation step from the viewpoint of improving the alkali solubility of the polyamideimide resin. It is preferable that the molar ratio of the usage-amount of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (c) to the usage-amount of trimellitic anhydride (d) is 85/15 to 100/0, , more preferably 90/10 to 99/1, and still more preferably 90/10 to 98/2.

Diamine compound (B) used to obtain imidide (A) (specifically, it means dimer diamine (a) and carboxyl group-containing diamine (b), and other diamines (f) used as necessary) and acid anhydride (C) (specifically, one selected from the group consisting of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (c) and trimellitic anhydride (d)) or two types) is not limited. It is preferable that the molar ratio with respect to the usage-amount of a diamine compound (B) is 2.0 or more and 2.4 or less, and, as for the usage-amount of an acid anhydride (C), it is more preferable that it is a quantity used as 2.0 or more and 2.2 or less in the said molar ratio.

In the amidimidization step, the imidide (A) obtained in the imidization step is reacted with a diisocyanate compound (e), and a polyamideimide resin containing a substance having a structure represented by the following general formula (3) get

The specific kind of diisocyanate compound (e) is not limited. The diisocyanate compound (e) may be comprised from one type of compound, and may be comprised from multiple types of compounds.

Specific examples of the diisocyanate compound (e) include 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylyl aromatic diisocyanates such as rendiisocyanate, m-xylylenediisocyanate, and 2,4-tolylene dimer; Aliphatic diisocyanate, such as hexamethylene diisocyanate, trimethyl hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, norbornene diisocyanate, etc. are mentioned. From the viewpoint of improving both the alkali solubility of the polyamideimide resin and the light transmittance of the polyamideimide resin, the diisocyanate compound (e) preferably contains an aliphatic isocyanate, and the diisocyanate compound (e) is an aliphatic isocyanate. more preferably.

The usage-amount of the diisocyanate compound (e) in the amidimidation process is not limited. From the viewpoint of imparting appropriate alkali solubility to the polyamideimide resin, the amount of the diisocyanate compound (e) to be used is 0.3 or more and 1.0 as a molar ratio with respect to the amount of the diamine compound (B) used to obtain the imide compound (A). It is preferable to set it as below, It is more preferable to set it as 0.4 or more and 0.95 or less, It is especially preferable to set it as 0.50 or more and 0.90 or less.

The polyamideimide resin produced in this way contains a substance having a structure represented by the following general formula (3).

In the said general formula (3), X is each independently a diamine residue (residue of a diamine compound (B)), Y is each independently an aromatic ring or a cyclohexane ring, and Z is a residue of a diisocyanate compound (e). n is a natural number.

(curable compound)

The curable resin composition of this invention contains a sclerosing|hardenable compound further. As the curable compound, a known and usual compound having a functional group capable of curing reaction by heat or light is used. For example, a thermosetting compound having a functional group capable of curing reaction by heat, such as a cyclic (thio) ether group, and a photocurable compound having a functional group capable of curing reaction by light, such as an ethylenically unsaturated double bond group, are mentioned. Among these, it is preferable to use a thermosetting compound, particularly an epoxy resin.

Examples of the epoxy resin include bisphenol A type epoxy resin, brominated epoxy resin, novolak type epoxy resin, bisphenol F type epoxy resin, hydrogenated bisphenol A type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin, alicyclic epoxy resin a resin, a trihydroxyphenylmethane type epoxy resin, a bixylenol type or a biphenol type epoxy resin, or a mixture thereof; A bisphenol S-type epoxy resin, a bisphenol A novolak-type epoxy resin, a heterocyclic epoxy resin, a biphenyl novolak-type epoxy resin, a naphthalene group containing epoxy resin, the epoxy resin etc. which have a dicyclopentadiene skeleton are mentioned.

In particular, when using a thermosetting compound, the thermosetting compound has an equivalent ratio (alkali-soluble group such as carboxyl group: thermosetting group such as epoxy group) with alkali-soluble resin (polyimide resin, polyamideimide resin, etc.) of 1:0.1 to 1 : It is preferable to mix|blend in the ratio used as 10. By setting it as such a compounding ratio, developability becomes favorable and it becomes what can form a fine pattern easily. The equivalent ratio is more preferably 1:0.2 to 1:5.

(Core Shell Rubber Particles)

It is preferable that curable resin composition of this invention contains a core-shell rubber particle further. Thereby, it is possible to provide a curable resin composition which is excellent in both developability and heat resistance and is suitable for use as an insulating film of electronic components such as flexible printed wiring boards, and which can satisfy the required performance of both solder resist and coverlay. will do

The core-shell rubber particles constituting the curable resin composition of the present invention have a function of improving the flexibility of the core-shell rubber particles without lowering the adhesiveness.

The core-shell rubber particles refer to a rubber material having a multilayer structure composed of a core layer having a different composition and one or more shell layers covering the core layer. As will be described later, the core-shell rubber particles are formed of a material having excellent flexibility in the core layer, and the shell layer being made of a material having excellent affinity for other components, thereby achieving low modulus of elasticity by blending the rubber component, Dispersibility becomes good.

According to the characteristic combination configuration of the present invention in which such core-shell rubber particles are blended, it is possible to provide a cured product having excellent flexibility without occurrence of cracks or the like in excessive bending tests even after heat treatment such as reflow. It is possible to exhibit a unique effect that is not present in the prior art.

As a constituent material of the core layer, a material excellent in flexibility is used. Specific examples thereof include silicone-based elastomers, butadiene-based elastomers, styrene-based elastomers, acrylic-based elastomers, polyolefin-based elastomers, and silicone/acrylic composite-based elastomers.

On the other hand, as a constituent material of the shell layer, a material excellent in affinity to other components is used. For example, when curable resin composition contains an epoxy resin, it is preferable to use the core-shell rubber particle which has a shell layer comprised from the material excellent in affinity with respect to an epoxy resin. More preferably, they are an acrylic resin and an epoxy resin.

It is preferable that such a core-shell rubber particle has a hardening reactive group on the surface from a viewpoint of storage stability, and a thermosetting reactive group may be sufficient as such a curable reactive group, or a photocurable reactive group may be sufficient as it. Moreover, the core-shell rubber particle may have 2 or more types of curable reactive groups.

Examples of the thermosetting reactive group include a hydroxyl group, a carboxyl group, an isocyanate group, an imino group, an epoxy group, an oxetanyl group, a mercapto group, a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an ethoxyethyl group, and an oxazoline group. More preferably, it is an epoxy group.

A vinyl group, a styryl group, a methacryl group, an acryl group etc. are mentioned as a photocurable reactive group. Since reactivity becomes appropriate even when there is a large amount of filler content, it is preferable that they are a methacryl group and an acryl group.

Here, it does not specifically limit as a method of introduce|transducing a sclerosing|hardenable reactive group to the surface of a core-shell rubber particle, A well-known and usual method can be used. For example, when forming the shell layer around the core layer, as a constituent material of the shell layer, a material having a curable reactive group different from a functional group for polymerization reaction with the core layer can be introduced by polymerization into the core layer.

As a commercial item of core-shell rubber particle|grains, the Rohm & Haas company make Paraloid ELX2655, the Nippon Kosei Rubber Co., Ltd. XER-91, etc. are mentioned.

Curable resin composition of this invention WHEREIN: It is preferable that it is excellent in crack resistance that the core-shell rubber particle has an average particle diameter of 2 micrometers or less. More preferably, it is 0.01-1 micrometer. In addition, in this specification, an average particle diameter is the value of D50 measured using the Microtrac particle size analyzer manufactured by Nikkiso.

Curable resin composition of this invention WHEREIN: It is preferable that content of a core-shell rubber particle is 1-30 mass % per organic component in solid content in a composition. If it is 1 mass % or more, it is preferable at the point which is excellent in crack resistance. On the other hand, if it is 30 mass % or less, it is preferable at the point which is excellent in printability and developability. More preferably, it is 3-20 mass %. Moreover, the curable resin composition of this invention may contain the core-shell rubber particle which has a curable reactive group, and the core-shell rubber particle which does not have a curable reactive group. In addition, an organic component means all solid components other than inorganic components, such as a filler, here.

(Photoinitiator)

It is preferable that curable resin composition of this invention further contains a photoinitiator, when setting it as a photosensitive resin composition. As this photoinitiator, a well-known and usual thing can be used, Especially when applying the curable resin composition of this invention to the PEB process after light irradiation mentioned later, it is suitable to use the photoinitiator which also has a function as a photobase generator. . In addition, in this PEB process, you may use together a photoinitiator and a photobase generator.

A photopolymerization initiator also having a function as a photobase generator is one that can function as a catalyst for polymerization of a thermosetting compound, which is a curable compound, by changing the molecular structure or cleaving the molecule by irradiation with light such as ultraviolet or visible light. A compound that produces more basic substances. As a basic substance, a secondary amine and a tertiary amine are mentioned, for example.

Examples of the photopolymerization initiator also having a function as such a photobase generator include an α-aminoacetophenone compound, an oxime ester compound, an acyloxyimino group, an N-formylated aromatic amino group, an N-acylated aromatic amino group, and nitrobenzylcarba. The compound etc. which have substituents, such as a mate group and an alkoxybenzyl carbamate group, are mentioned. Especially, an oxime ester compound and (alpha)-aminoacetophenone compound are preferable, and an oxime ester compound is more preferable. As the α-aminoacetophenone compound, it is particularly preferable to have two or more nitrogen atoms.

The α-aminoacetophenone compound may have a benzoin ether bond in the molecule, and when irradiated with light, cleavage occurs within the molecule to generate a basic substance (amine) that exhibits a curing catalytic action.

As an oxime ester compound, if it is a compound which produces|generates a basic substance by light irradiation, any can be used.

These photoinitiators may be used individually by 1 type, and may be used in combination of 2 or more type. The compounding quantity of the photoinitiator in a resin composition becomes like this. Preferably it is 0.1-40 mass parts with respect to 100 mass parts of total amounts of alkali-soluble resin, More preferably, it is 0.3-15 mass parts. When it is 0.1 mass part or more, the contrast of developability of a light irradiated part/unirradiated part can be obtained favorably. Moreover, when it is 40 mass parts or less, hardened|cured material property improves.

The following components can be further mix|blended with curable resin composition of this invention as needed.

(polymer resin)

Curable resin composition of this invention can mix|blend a well-known and usual polymer resin for the purpose of the improvement of the flexibility of the hardened|cured material obtained, and dry to touch property. Examples of such polymer resins include cellulose-based, polyester-based, phenoxy resin-based polymers, polyvinylacetal-based, polyvinylbutyral-based, polyamide-based, polyamideimide-based binder polymers, and elastomers. These polymer resins may be used individually by 1 type, and may use 2 or more types together.

(inorganic filler)

Curable resin composition of this invention suppresses cure shrinkage of hardened|cured material, and in order to improve characteristics, such as adhesiveness and hardness, an inorganic filler can be mix|blended. Examples of such inorganic fillers include barium sulfate, amorphous silica, fused silica, spherical silica, talc, clay, magnesium carbonate, calcium carbonate, aluminum oxide, aluminum hydroxide, silicon nitride, aluminum nitride, boron nitride, Neuburg diatomaceous earth, and the like. can

(coloring agent)

Curable resin composition of this invention can mix|blend well-known and usual coloring agents, such as red, orange, blue, green, yellow, white, and black. Any of a pigment, dye, and a pigment|dye may be sufficient as such a coloring agent.

(organic solvent)

Curable resin composition of this invention can mix|blend the organic solvent for manufacture of a resin composition, or for viscosity adjustment for apply|coating to a base material or a carrier film. Examples of such organic solvents include ketones, aromatic hydrocarbons, glycol ethers, glycol ether acetates, esters, alcohols, aliphatic hydrocarbons, petroleum solvents, and the like. These organic solvents may be used individually by 1 type, and may be used as 2 or more types of mixture.

(Other ingredients)

Curable resin composition of this invention can mix|blend components, such as a mercapto compound, an adhesion promoter, a thermosetting catalyst, antioxidant, and a ultraviolet absorber, further as needed. For these, a well-known and customary thing can be used.

In addition, well-known and usual thickeners such as finely divided silica, hydrotalcite, organic bentonite, and montmorillonite, antifoaming agents such as silicone, fluorine, and polymer, and/or leveling agents, silane coupling agents, rust inhibitors, etc. can

The curable resin composition of the present invention including the configuration as described above is a laminate structure having a resin layer (A) and a resin layer (B) laminated on a flexible printed wiring board via a resin layer (A) to be described later. In order to form the resin layer (B) in this, it can use suitably.

(Laminated Structure)

The laminated structure of this invention has a resin layer (A) and a resin layer (B) laminated|stacked on base materials, such as a flexible printed wiring board, through a resin layer (A).

Here, in the laminated structure of this invention, a resin layer (A) and a resin layer (B) function substantially as a contact bonding layer and a protective layer, respectively. The laminated structure of the present invention is characterized in that the resin layer (B) contains the curable resin composition, and the resin layer (A) contains an alkali-developable resin composition containing an alkali-soluble resin and a heat-reactive compound. has

In the present invention, by making the resin layer (B) on the upper side of the laminate structure in which two resin layers are laminated contains the curable resin composition of the present invention, excellent heat resistance can be realized without impairing developability. . Moreover, by using a polyamide-imide resin as alkali-soluble resin other than a polyimide resin, while providing the outstanding heat resistance and low repulsion property without impairing developability, it becomes possible to make small the curvature after heating. Further, by containing the core-shell rubber particles in the curable resin composition of the present invention, a laminated structure having excellent developability and heat resistance and particularly excellent in flexibility after solder reflow can be obtained. When core-shell rubber particles are contained in the resin layer (A) on the lower layer side of the laminated structure, there is a possibility that the adhesion may decrease, but the resin layer (B) on the upper layer side is the curable resin composition containing the core-shell rubber particles. By including it, the softness improvement effect by the core-shell rubber particle can be acquired without the fall of adhesiveness. Therefore, in this invention, it is preferable not to contain a core-shell rubber particle in a resin layer (A).

[Resin Layer (A)]

(Alkali developable resin composition)

As an alkali developing type resin composition which comprises a resin layer (A), what is necessary is just a resin composition which can be developed with the alkali solution containing alkali-soluble resin and a heat-reactive compound. Preferably, as alkali-soluble resin, the resin composition containing the compound which has a phenolic hydroxyl group, the compound which has a carboxyl group, and the compound which has a phenolic hydroxyl group and a carboxyl group is mentioned, A well-known and usual thing is used.

For example, the resin composition containing carboxyl group-containing resin or carboxyl group-containing photosensitive resin, the compound which has an ethylenically unsaturated bond, and the heat-reactive compound which are conventionally used as a soldering resist composition is mentioned.

Here, as the carboxyl group-containing resin or the carboxyl group-containing photosensitive resin, and the compound having an ethylenically unsaturated bond, a known and conventional compound is used, and as the thermally reactive compound, a functional group capable of curing reaction by heat such as a cyclic (thio)ether group A known and conventional compound having

Although this resin layer (A) may or may not contain a photoinitiator, as a photoinitiator used when it contains a photoinitiator, the thing similar to the photoinitiator used by the said curable resin composition is mentioned. .

In addition, the resin layer (A) can contain other components similar to the said curable resin composition, such as a polymer resin, an inorganic filler, a coloring agent, and an organic solvent.

[Resin Layer (B)]

The resin layer (B) is formed of the alkali-soluble polyimide resin described above, an alkali-soluble resin other than that, and a curable resin composition containing a curable compound, and the other points are not particularly limited. .

Here, as the said alkali-soluble polyimide resin, alkali-soluble resin other than that, a sclerosing|hardenable compound, etc. can use resin, a compound, etc. similar to what comprises the curable resin composition of this invention.

Further, the curable resin composition constituting the resin layer (B) is preferably an alkali-soluble resin other than the polyimide resin, more preferably a polyamideimide resin, still more preferably represented by the general formula (1) A polyamideimide resin having a structure and a structure represented by the general formula (2) is included. By setting it as such a structure, the resin composition more excellent in characteristics, such as bending resistance and heat resistance, can be obtained, without impairing developability.

Since the laminated structure of this invention is excellent in flexibility, it can be used for at least any one of the bending part and non-bending part of electronic components, such as a flexible printed wiring board, For example, a coverlay of a flexible printed wiring board, soldering resist, and interlayer insulation. It can be used for the use of at least any one of the materials.

It is preferable to use the laminated structure of this invention which concerns on the structure as demonstrated above as a dry film by which the at least single side|surface is supported or protected by the film.

(dry film)

A dry film can be manufactured as follows, for example.

That is, first, on a carrier film (support film), the curable resin composition constituting the resin layer (B) and the alkali developable resin composition constituting the resin layer (A) are each diluted with an organic solvent to an appropriate viscosity. It is adjusted and applied sequentially by a known method such as a comma coater according to a conventional method. Then, the dry film which formed the coating film of a resin layer (B) and a resin layer (A) on a carrier film is producible by drying at the temperature of 50-130 degreeC normally for 1 to 30 minutes after that. On this dry film, in order to prevent dust from adhering to the coating-film surface, a cover film (protective film) which can further peel can be laminated|stacked. As a carrier film and a cover film, a conventionally well-known plastic film can be used suitably, and about a cover film, when peeling a cover film, it is preferable if it is smaller than the adhesive force of a resin layer and a carrier film. Although there is no restriction|limiting in particular about the thickness of a carrier film and a cover film, Generally, it selects suitably in the range of 10-150 micrometers.

(cured product)

The hardened|cured material of this invention is obtained by hardening|curing the curable resin composition of this invention mentioned above, or the laminated structure of this invention.

(Electronic parts)

The curable resin composition and laminated structure of this invention which were demonstrated above can be used effectively for electronic components, such as a flexible printed wiring board, for example. Specifically, a flexible printed wiring board having a cured product of an insulating film formed by forming a layer of the curable resin composition or laminated structure of the present invention on a flexible printed wiring substrate, patterning by light irradiation, and forming a pattern with a developer solution, etc. can be heard

Hereinafter, as an example of an electronic component, the manufacturing method of a flexible printed wiring board is demonstrated concretely.

(Manufacturing method of flexible printed wiring board)

Manufacture of the flexible printed wiring board using the laminated structure of this invention can be performed according to the procedure shown in the process chart of FIG. 1, for example. That is, a step of forming a layer of the laminated structure of the present invention on a flexible printed wiring substrate on which a conductor circuit is formed (lamination step), a step of irradiating the layer of the laminated structure with active energy rays in a pattern (exposure step), and a process (developing process) of alkali-developing the layer of this laminated structure to form a layer of a patterned laminated structure. Moreover, after alkali image development as needed, photocuring and thermosetting (post-curing process) are further performed, the layer of a laminated structure can be fully hardened, and a highly reliable flexible printed wiring board can be obtained.

In addition, manufacture of the flexible printed wiring board using the laminated structure of this invention can also be performed according to the procedure shown in the process chart of FIG. 2, for example. That is, a step of forming a layer of the laminated structure of the present invention on a flexible printed wiring substrate on which a conductor circuit is formed (lamination step), a step of irradiating the layer of the laminated structure with active energy rays in a pattern (exposure step), It is a manufacturing method including the process of heating the layer of this laminated structure (heating (PEB) process), and alkali-developing the layer of the laminated structure to form the layer of the patterned laminated structure (development process). Moreover, after alkali image development as needed, photocuring and thermosetting (post-curing process) are further performed, the layer of a laminated structure can be fully hardened, and a highly reliable flexible printed wiring board can be obtained.

Hereinafter, each process in FIG. 1 or FIG. 2 is demonstrated further in detail.

[Lamination process]

In this process, the resin layer 3 (resin layer (A)) of the alkali developable resin composition containing alkali-soluble resin etc., on the flexible printed wiring base material 1 in which the conductor circuit 2 was formed, and the resin layer 3 ), the laminated structure containing the resin layer 4 (resin layer (B)) of curable resin composition of this invention is formed. Here, each resin layer constituting the laminated structure forms the resin layers 3 and 4 by sequentially applying and drying the resin composition constituting the resin layers 3 and 4 to the wiring substrate 1, for example. Alternatively, the resin composition constituting the resin layers 3 and 4 may be formed in the form of a dry film having a two-layer structure by a method of laminating on the wiring substrate 1 .

Known methods, such as a blade coater, a lip coater, a comma coater, and a film coater, may be sufficient as the coating method with respect to the wiring base material of the resin composition. In addition, the drying method uses a hot air circulation drying furnace, an IR furnace, a hot plate, a convection oven, etc. equipped with a heat source of a heating method by steam, a method in which the hot air in the dryer is brought into countercurrent contact, and from the nozzle to the support. A well-known method, such as the method of spraying, may be sufficient.

[Exposure process]

In this process, the photoinitiator contained in the resin layer 4 is activated in the form of a negative pattern by irradiation of an active energy ray, and an exposure part is hardened. In the case of the composition using the PEB process mentioned later, the photoinitiator or photobase generator which has a function as a photobase generator is activated in the form of a negative pattern, and a base is generated.

As an exposure machine used in this process, a direct drawing apparatus, an exposure machine equipped with a metal halide lamp, etc. can be used. The mask for exposure on the pattern is a negative mask.

As an active energy ray used for exposure, it is preferable to use the laser beam or scattered light whose maximum wavelength is in the range of 350-450 nm. By making a maximum wavelength into this range, a photoinitiator can be activated efficiently. In addition, although the exposure amount changes with film thickness etc., it can be set as 50-1500 mJ/cm<2>, for example.

[PEB process]

In this process, an exposed part is hardened by heating a resin layer after exposure. By this step, a photoinitiator having a function as a photobase generator is used, or a base generated in the exposure step of the resin layer (B) containing a composition in which a photoinitiator and a photobase generator are used in combination, the resin layer ( B) can be hardened to the deep part. Heating temperature is 70-150 degreeC, for example. Heating time is 1 to 120 minutes, for example. Since curing of the resin composition in the present invention is, for example, a ring-opening reaction of an epoxy resin by a thermal reaction, deformation and curing shrinkage can be suppressed as compared with the case where curing proceeds in a photo-radical reaction.

[Development process]

In this process, an unexposed part is removed by alkali development, and the insulating film of the negative type pattern shape, for example, a coverlay and a soldering resist is formed. As a developing method, it can follow well-known methods, such as dipping. Moreover, as a developing solution, imidazoles, such as sodium carbonate, potassium carbonate, potassium hydroxide, amines, 2-methylimidazole, aqueous alkali solutions, such as tetramethylammonium hydroxide aqueous solution (TMAH), or these mixtures can be used.

[Post-curing process]

In addition, after the image development process, you may light-irradiate an insulating film further, and you may heat at 150 degreeC or more, for example.

<Example>

Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, this invention is not limited by these Examples and a comparative example.

(Synthesis Example 1)

28.61 g (0.052 mol) of an aliphatic diamine derived from a dimer acid having 36 carbon atoms as dimer diamine (a) (product name PRIAMINE1075 manufactured by Croda Japan), a carboxyl group in a 4-neck 300 mL flask equipped with a nitrogen gas introduction tube, a thermometer, and a stirrer 3.26 g (0.028 mol) of 3,5-diaminobenzoic acid as the containing diamine (b) and 85.8 g of γ-butyrolactone were added at room temperature to dissolve.

Then, 30.12 g (0.152 mol) of cyclohexane-1,2,4-tricarboxylic acid anhydride (c) and 3.07 g (0.016 mol) of trimellitic anhydride (d) were added, and the mixture was maintained at room temperature for 30 minutes. Furthermore, after adding 30 g of toluene, heating up to 160 degreeC, and removing the water produced|generated with toluene, it hold|maintained for 3 hours, and obtained the solution containing an imidide by cooling to room temperature.

14.30 g (0.068 mol) of trimethylhexamethylene diisocyanate as the diisocyanate compound (e) was added to the solution containing the obtained imidide, maintained at a temperature of 160° C. for 32 hours, and diluted with 21.4 g of cyclohexanone A solution (A-1) containing polyamideimide resin was obtained. The mass average molecular weight Mw of the obtained polyamideimide resin was 5250, solid content was 41.5 mass %, acid value was 63 mgKOH/g, and content of dimer diamine (a) was 40.0 mass %.

(Synthesis Example 2)

29.49 g (0.054 mol) of an aliphatic diamine derived from a dimer acid having 36 carbon atoms as dimer diamine (a) (product name PRIAMINE1075 manufactured by Croda Japan), a carboxyl group in a 4-neck 300 mL flask equipped with a nitrogen gas introduction tube, a thermometer, and a stirrer 4.02 g (0.026 mol) of 3,5-diaminobenzoic acid as the containing diamine (b) and 73.5 g of γ-butyrolactone were added at room temperature to dissolve.

Subsequently, 31.71 g (0.160 mol) of cyclohexane-1,2,4-tricarboxylic acid anhydride (c) and 1.54 g (0.008 mol) of trimellitic anhydride (d) were added, and the mixture was maintained at room temperature for 30 minutes. Further, 30 g of toluene was added, the temperature was raised to 160°C, and after removing water generated along with toluene, the mixture was maintained for 3 hours and cooled to room temperature to obtain a solution containing an imidized product.

6.90 g (0.033 mol) of trimethylhexamethylene diisocyanate and 8.61 g (0.033 mol) of dicyclohexylmethane diisocyanate as a diisocyanate compound (e) are thrown into the solution containing the obtained imidate, and the temperature of 160 degreeC was maintained for 32 hours and diluted with 36.8 g of cyclohexanone to obtain a solution (A-2) containing polyamideimide resin. The mass average molecular weight Mw of the obtained polyamideimide resin was 5840, solid content was 40.4 mass %, acid value 62 mgKOH/g, and content of dimer diamine (a) was 40.1 mass %.

(Synthesis Example 3)

2,2'-bis[4-(4-aminophenoxy)phenyl]propane 6.98g, 3,5-diaminobenzoic acid 3.80g, polyether 8.21 g of diamine (manufactured by Huntsman, product name Elastamine RT1000, molecular weight 1025.64) and 86.49 g of γ-butyrolactone were added and dissolved at room temperature.

Then, 17.84 g of cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride and 2.88 g of trimellitic anhydride were added, and the mixture was maintained at room temperature for 30 minutes. Furthermore, after adding 30 g of toluene, heating up to 160 degreeC, and removing the water which generate|occur|produces with toluene, it hold|maintained for 3 hours, and obtained the imidated material solution by cooling to room temperature.

To the obtained imidated solution, 9.61 g of trimellitic anhydride and 17.45 g of trimethylhexamethylene diisocyanate were added, and the mixture was maintained at a temperature of 160°C for 32 hours. In this way, a polyamideimide resin solution (A-3) containing a carboxyl group was obtained. The solid content was 40.1 mass %, and the acid value was 83 mgKOH/g.

(Synthesis Example 4)

22.4 g of 3,3'-diamino-4,4'-dihydroxydiphenylsulfone, 2,2'-bis[ 8.2 g of 4-(4-aminophenoxy)phenyl]propane, 30 g of NMP, 30 g of γ-butyrolactone, 27.9 g of 4,4'-oxydiphthalic anhydride, and 3.8 g of trimellitic anhydride were added, and under a nitrogen atmosphere , and stirred at room temperature and 100 rpm for 4 hours. Next, 20 g of toluene was added, and the mixture was stirred for 4 hours while distilling off toluene and water at a silicone bath temperature of 180°C and 150 rpm to obtain a polyimide resin solution (PI-1) having a phenolic hydroxyl group and a carboxyl group.

The acid value of the obtained resin (solid content) was 18 mgKOH, Mw was 10,000, and the hydroxyl equivalent was 390.

(Examples 1-1 to 1-9 and Comparative Examples 1-1 and 1-2)

According to the component composition shown in Table 1, each of the materials described in Examples 1-1 to 1-9 and Comparative Examples 1-1 and 1-2 was blended, pre-mixed with a stirrer, and then kneaded with a three-roll mill, Each resin composition for forming a resin layer was manufactured. Unless otherwise specified, the value in a table|surface is a mass part of solid content.

*1-1) Polyamideimide resin-containing solutions (A-1) to (A-3): Synthesis Examples 1 to 3

*1-2) Alkali-soluble resin (PI-1): Synthesis Example 4

*1-3) Photoinitiator: oxime-based photoinitiator IRGACURE OXE02 (manufactured by BASF)

*1-4) Epoxy resin: Bisphenol A type epoxy resin E828, epoxy equivalent 190, mass average molecular weight 380 (manufactured by Mitsubishi Chemical Co., Ltd.)

<Formation of resin layer>

The flexible printed wiring base material in which the circuit of 18 micrometers of copper thickness is formed was prepared, and it pre-processed using Meek Corporation CZ-8100. Then, each resin composition obtained in Examples 1-1 to 1-9 and Comparative Examples 1-1 and 1-2 was apply|coated to the flexible printed wiring base material which performed the pretreatment so that the film thickness after drying might be set to 30 micrometers, respectively. Then, it dried at 90 degreeC for 30 minute(s) in a hot-air circulation type drying furnace, and formed the uncured resin layer.

<developability (alkali solubility)>

About the non-hardened resin layer on each flexible printed wiring base material on which the resin layer was formed as mentioned above, 300 mJ / through a negative mask first using the exposure apparatus (HMW-680-GW20) equipped with a metal halide lamp. It pattern-exposed so that the opening with a diameter of 200 micrometers might be formed in cm<2>. The board|substrate which has the resin layer after exposure was heat-processed at 90 degreeC for 30 minute(s). Then, the board|substrate was immersed in 30 degreeC 1 mass % sodium carbonate aqueous solution, it developed for 1 minute, the state of pattern formation was observed, and developability (alkali solubility) was evaluated. The evaluation criteria are as follows.

(circle): An exposed part shows developability, an unexposed part shows developability, and pattern formation is good.

x: Although the unexposed part shows developability, the resolution pattern formation is poor (resolution is insufficient)

<Heat resistance (solder heat resistance)>

(Production of evaluation board)

About the non-hardened resin layer on each flexible printed wiring base material on which the resin layer was formed as mentioned above, 300 mJ / through a negative mask first using the exposure apparatus (HMW-680-GW20) equipped with a metal halide lamp. It pattern-exposed so that the opening with a diameter of 200 micrometers might be formed in cm<2>. Then, after performing a PEB process at 90 degreeC for 30 minutes, image development (30 degreeC, 0.2 MPa, ₁ mass % _Na2CO3 aqueous solution) is performed for 60 seconds, and hardened|cured resin layer by thermosetting at 150 degreeC x 60 minutes. A flexible printed wiring board (evaluation board) on which was formed was produced.

(Assessment Methods)

To the evaluation substrate produced as described above, a rosin-based flux was applied and immersed in a solder bath previously set at 260° C. for 20 seconds (10 seconds × 2 times) to prevent expansion and peeling of the cured coating film (resin layer). It observed and evaluated the heat resistance (solder heat resistance). The evaluation criteria are as follows.

○: There was no swelling or peeling even after immersion for 10 seconds × 2 times

×: When immersed for 10 seconds × 1 time, swelling and peeling occurred

<Chemical resistance (Gold plating resistance)>

The following method evaluated using the evaluation board|substrate similar to evaluation of the said heat resistance.

With respect to the evaluation substrate, using a commercially available electroless nickel plating bath and an electroless gold plating bath, at 80 to 90° C., plating of 5 µm of nickel and 0.05 µm of gold was performed, and the substrate and the resin layer were observed to obtain chemical resistance. (Gold plating resistance) was evaluated. The evaluation criteria are as follows.

○: There is no permeation between the substrate and the coating film (resin layer)

(triangle|delta): that permeation is confirmed between a board|substrate and a coating film (resin layer)

x: What peeling generate|occur|produced in a part of coating film (resin layer)

<Repulsion (Spring People)>

(Production of test piece)

On the polyimide film, each resin composition obtained in Examples 1-1 to 1-9 and Comparative Examples 1-1 and 1-2 was applied so that the film thickness after drying was set to 30 µm, followed by 90 in a hot air circulation drying furnace. It dried at ℃ for 30 minutes to form an uncured resin layer. Then, using the exposure apparatus (HMW-680-GW20) equipped with a metal halide lamp, it exposed at 300 mJ/cm<2> without interposing a mask. Then, after performing the PEB process for 30 minutes at 90 degreeC, image development (30 degreeC, 0.2 MPa, ₁ mass % _Na2CO3 aqueous solution) is performed for 60 seconds, and hardened|cured by thermosetting at 150 degreeC x 60 minutes. A polyimide film test piece in which a layer was formed was produced.

(Assessment Methods)

The polyimide film test piece produced as described above was cut out to 2 cm x 7 cm, the both ends of the long side were put together so that it became a belt-shaped ring, and the fitting part of both ends was fixed to the electronic balance with tape. In the state in which the ring was bent, the load when the ring was pressed with a glass plate so that the distance between the upper and lower sides of the ring was 3 mm was measured as the repulsive force (g), and the repulsion property (spring stiffness) was evaluated. The evaluation criteria are as follows.

○: less than 30g

△: 30 g or more and less than 45 g

×: 45 g or more

<Amount of warpage after curing>

The following method evaluated using the test piece similar to evaluation of the said repellency.

After cutting the test piece to 5 cm × 5 cm, the substrate is placed on a horizontal test bench with the curved side facing up, and the distance of each of the four vertices from the test bench is measured up to 1 mm in a straight-normal manner, and the maximum value of the four points is the amount of bending. Thus, the amount of warpage after curing was evaluated. The evaluation criteria are as follows.

○: less than 3mm warp

△: Deflection amount 3 mm or more and less than 6 mm

×: Deflection amount of 6 mm or more

These evaluation results are shown in Table 2.

(Examples 1-10 to 1-12)

According to the component composition shown in Table 3, each of the materials described in Examples 1-10 to 1-12 was blended, pre-mixed with a stirrer, and then kneaded with a three-roll mill to form a resin layer (A) Each resin composition for forming a resin composition and a resin layer (B) was manufactured. Unless otherwise specified, the value in a table|surface is a mass part of solid content.

*1-1) Polyamideimide resin-containing solutions (A-1) to (A-3): Synthesis Examples 1 to 3

*1-2) Alkali-soluble resin (PI-1): Synthesis Example 4

*1-3) Photoinitiator: oxime-based photoinitiator IRGACURE OXE02 (manufactured by BASF)

*1-4) Epoxy resin: Bisphenol A type epoxy resin E828, epoxy equivalent 190, mass average molecular weight 380 (manufactured by Mitsubishi Chemical Co., Ltd.)

*1-5) Alkali-soluble resin: P7-532: Polyurethane acrylate, acid value 47 mgKOH/g (manufactured by Kyoesha Chemical Co., Ltd.)

*1-6) Photocurable monomer: BPE-500: ethoxylated bisphenol A dimethacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd.)

<Formation of the resin layer (A)>

The flexible printed wiring base material in which the circuit of 18 micrometers of copper thickness is formed was prepared, and it pre-processed using Meek Corporation CZ-8100. Then, each resin composition for forming the resin layer (A) obtained in Examples 1-10 - 1-12 was apply|coated to the flexible printed wiring base material which performed the pretreatment so that the film thickness after drying might be set to 20 micrometers, respectively. Then, it dried at 90 degreeC for 30 minute(s) in a hot-air circulation type drying furnace, and the resin layer was formed.

<Formation of the resin layer (B)>

On the resin layer (A) formed above, each resin composition for forming the resin layer (B) obtained in Examples 1-10 to 1-12 was apply|coated so that the film thickness after drying might be set to 10 micrometers, respectively. Then, it dried at 90 degreeC for 30 minute(s) in a hot-air circulation type drying furnace, and the resin layer (B) was formed.

In this way, the non-hardened laminated structure containing the resin layer (A) and the resin layer (B) of Examples 1-10 to 1-12 was formed on a flexible printed wiring base material.

About the non-hardened laminated structure formed as mentioned above, the evaluation performed with respect to the non-hardened resin layer in Examples 1-1 to 1-9 and Comparative Examples 1-1 and 1-2 was similar. method was carried out.

These evaluation results are shown in Table 4.

As is clear from the evaluation results shown in Tables 2 and 4, it was confirmed that, in the resin composition of each Example, excellent developability, heat resistance, low repulsion properties, and low warpage after heating were obtained.

(Examples 2-1 to 2-5 and Comparative Examples 2-1 and 2-2)

According to the component composition shown in Table 5, each of the materials described in Examples 2-1 to 2-5 and Comparative Examples 2-1 and 2-2 was blended, pre-mixed with a stirrer, and then kneaded with a three-roll mill, A resin composition for forming each resin layer was prepared. Unless otherwise specified, the value in a table|surface is a mass part of solid content.

*2-1) Alkali-soluble resin 1 (PI-1): Synthesis Example 4

*2-2) Alkali-soluble resin 2: carboxyl group-containing epoxy acrylate ZAR-1035 (acid value 98 mgKOH/g, manufactured by Nippon Kayaku Co., Ltd.)

*2-3) Polyamideimide-containing solution (A-1): Synthesis Example 1

*2-4) Oxime-based photopolymerization initiator: IRGACURE OXE02 (manufactured by BASF)

*2-5) Epoxy resin: bisphenol A epoxy resin E828, epoxy equivalent 190, mass average molecular weight 380 (manufactured by Mitsubishi Chemical Co., Ltd.)

*2-6) Core shell polymer 1: Paraloid EXL-2655 (manufactured by Rohm and Haas)

*2-7) Core shell polymer 2: Staphyloid AC-3355 (manufactured by Gantz Chemicals)

*2-8) Masterbatch containing core-shell polymer 1: ("Araldite (registered trademark)" MY721: 75 mass %/core-shell polymer particle A (volume average particle diameter: 100 nm, core part: butadiene/styrene) Copolymer [Tg: -25 DEG C], shell portion: methyl methacrylate / glycidyl methacrylate / styrene copolymer): 25 mass % masterbatch), and the core shell polymer particles A are disclosed in Japanese Patent Laid-Open No. 2005 It was synthesized by the method described in -248109 publication. However, the ratio of butadiene/styrene was made into 50 mass %/50 mass %. Moreover, after producing butadiene-styrene rubber latex, 5 mass %/5 mass %/5 mass % of methyl methacrylate / glycidyl methacrylate / styrene with respect to 100 mass % of this butadiene styrene rubber latex It was added in a ratio, and graft polymerization was carried out.

*2-9) Acrylate resin: ethoxylated bisphenol A dimethacrylate BPE-900 (manufactured by Shin-Nakamura Chemical Co., Ltd.)

<Formation of the resin layer (A)>

The flexible printed wiring base material in which the circuit of 18 micrometers of copper thickness is formed was prepared, and it pre-processed using Meek Corporation CZ-8100. Then, the film thickness after drying the resin composition which comprises each resin layer (A) obtained in Examples 2-1 to 2-4 and Comparative Examples 2-1 and 2-2 to the flexible printed wiring base material which performed the preprocessing, respectively. It was applied so that it became 25㎛. Then, it dried at 90 degreeC/30min in a hot-air circulation type drying furnace, and the resin layer (A) was formed.

<Formation of the resin layer (B)>

On the resin layer (A) formed above, the film thickness after drying the resin composition constituting each resin layer (B) obtained in Examples 2-1 to 2-4 and Comparative Examples 2-1 and 2-2 was respectively It applied so that it might become 10 micrometers. Then, it dried at 90 degreeC/30min in a hot-air circulation type drying furnace, and the resin layer (B) was formed.

In this way, the non-hardened laminated structure containing the resin layer (A) and the resin layer (B) of Examples 2-1 to 2-4 and Comparative Examples 2-1 and 2-2 is formed on a flexible printed wiring base material. did.

<developability (alkali solubility)>

About the non-hardened laminated structure on each flexible printed wiring base material on which the laminated structure was formed as mentioned above, first, using the exposure apparatus (HMW-680-GW20) equipped with a metal halide lamp, 500 mJ / through a negative mask It pattern-exposed so that the opening with a diameter of 200 micrometers might be formed in cm<2>. The board|substrate which has the non-hardened laminated structure after exposure was heat-processed for 30 minutes at 90 degreeC. Then, the board|substrate was immersed in 30 degreeC 1 mass % sodium carbonate aqueous solution, and it developed for 1 minute, and evaluated the availability of 200 micrometers opening pattern formation. The evaluation criteria are as follows.

(circle): An exposed part shows developability, an unexposed part shows developability, and pattern formation is good.

(triangle|delta): Although the unexposed part shows developability, the developability of an exposed part is insufficient, and pattern formation is impossible.

x: Since the unexposed part does not melt|dissolve in a developing solution, pattern formation is impossible

<Heat resistance>

About the non-hardened laminated structure on each flexible printed wiring base material on which the laminated structure was formed as mentioned above, first, using the exposure apparatus (HMW-680-GW20) equipped with a metal halide lamp, 500 mJ / through a negative mask It pattern-exposed so that the opening with a diameter of 200 micrometers might be formed in cm<2>. Then, after performing a PEB process at 90 degreeC for 30 minutes, image development (30 degreeC, 0.2 MPa, ₁ mass % _Na2CO3 aqueous solution) is performed for 60 seconds, and the laminated structure hardened|cured by thermosetting at 150 degreeC x 60 minutes. A flexible printed wiring board (evaluation board) on which was formed was produced. A rosin-based flux was applied to the evaluation substrate and immersed in a solder bath previously set at 260° C. for 20 seconds (10 seconds×2 times) to evaluate expansion and peeling of the cured coating film. The evaluation criteria are as follows.

○: There was no swelling or peeling even after immersion for 10 seconds × 2 times

×: When immersed for 10 seconds × 1 time, swelling and peeling occurred, and the adhesion was insufficient.

<Flexibility (bending test after solder reflow at 260°C)>

About the test piece which passed the said evaluation board|substrate three times through the reflow furnace previously set to 260 degreeC at maximum, the following test method evaluated bendability.

The test piece is folded at 180° so that the cured coating film is on the outside, sandwiched between two flat plates, loaded with a load G (standard weight of 1 kg) for 10 seconds, and then folded using an optical microscope. The operation to check whether cracks did not occur in the part was set as 1 cycle, and the number of times before cracks occurred was recorded. The evaluation criteria are as follows.

◎: Bending 20 times or more

○: Bending 10 times or more and less than 20 times

△: Bending 5 times or more but less than 10 times

×: less than 5 bends

These evaluation results are shown in Table 6.

As is clear from the evaluation results shown in the table, it was confirmed that, in the laminated structures of each Example, good flexibility was obtained even after solder reflow in addition to excellent developability and heat resistance.

Next, about the resin composition which comprises the resin layer (B) of the said Example 2-5, it carried out similarly to formation of the said resin layer (B) on the flexible printed wiring base material in which the circuit of 18 micrometers of copper thickness is formed, and a coating film was formed. About the obtained coating film, the above-mentioned resolution, heat resistance, and softness|flexibility were evaluated. Table 7 shows the evaluation results.

1: Flexible printed wiring substrate
2: Conductor circuit
3: resin layer
4: resin layer
5: Mask

Claims (10)

An alkali-soluble polyimide resin, an alkali-soluble polyamide-imide resin other than the said polyimide resin, and a sclerosing|hardenable compound are contained;
The mixing ratio of the polyamide-imide resin and the polyimide resin is 98:2 to 80:20 by mass,
The curable resin composition, wherein the polyamideimide resin is a polyamideimide resin having a structure represented by the following general formula (1) and a structure represented by the following general formula (2).

(X ₁ is a residue of an aliphatic diamine (a) derived from a dimer acid having 24 to 48 carbon atoms, X ₂ is a residue of an aromatic diamine (b) having a carboxyl group, and Y is each independently a cyclohexane ring or an aromatic ring) The curable resin composition according to claim 1, further comprising core-shell rubber particles. The curable resin composition according to claim 1, wherein the polyimide resin has a carboxyl group. The curable resin composition according to claim 3, wherein the polyimide resin has a carboxyl group and a phenolic hydroxyl group. The curable resin composition according to claim 1, wherein the curable compound is an epoxy resin. It is a laminated structure which has a resin layer (A) and a resin layer (B) laminated|stacked on a base material through this resin layer (A),
Alkali developing type in which the said resin layer (B) contains the curable resin composition in any one of Claims 1-5, and the said resin layer (A) contains an alkali-soluble resin and a heat-reactive compound. A laminated structure comprising a resin composition. A cured product comprising the curable resin composition according to any one of claims 1 to 5. A cured product comprising the laminated structure according to claim 6 . It has an insulating film containing the hardened|cured material of Claim 7, The electronic component characterized by the above-mentioned. It has an insulating film containing the hardened|cured material of Claim 8, The electronic component characterized by the above-mentioned.

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