KR20210097131A - Photosensitive thermosetting resin composition, dry film and printed wiring board - Google Patents

Abstract

(X₁은 탄소수가 24 내지 48인 이량체산 유래의 지방족 디아민 (a)의 잔기, X₂는 카르복실기를 갖는 방향족 디아민 (b)의 잔기, Y는 각각 독립적으로 시클로헥산환 또는 방향환이다.)Provided are a photosensitive thermosetting resin composition, a dry film, and a printed wiring board that can be developed with a slightly alkaline aqueous solution of sodium carbonate, have excellent photosensitivity, and have excellent mechanical properties such as heat resistance and flexibility. (A) an alkali-soluble polyamideimide resin, (B) a resin having an unsaturated double bond and a carboxyl group, (C) a thermosetting cyclic ether group-containing compound, and (D) a photopolymerization initiator; The photosensitive thermosetting resin composition characterized in that 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.)

Description

Photosensitive thermosetting resin composition, dry film and printed wiring board

The present invention relates to a photosensitive thermosetting resin composition (hereinafter, simply referred to as a "resin composition"), a dry film, and a printed wiring board which can develop aqueous alkali solution and is excellent also in the physical properties of a cured film.

In recent years, with the reduction in size and weight of an electronic device, the printed wiring board technology also achieves surprising evolution, and the request|requirement with respect to the soldering resist used is also increasing day by day.

On the other hand, in the solder resist, an alkali developing type photosensitive resin composition that can be developed with an aqueous alkali solution under the flow of miniaturization is mainstream, and properties such as heat resistance, flexibility, and low dielectric properties are added according to each use.

As a method of forming a solder resist using such an alkali developing type photosensitive resin composition, the photosensitive resin composition is applied to a base material, dried to form a resin layer, and then light-irradiated in a pattern shape with respect to the resin layer, and then developed with an alkali developer. The method of forming by doing is common.

In such a method of forming a solder resist, examples of the alkali developer include sodium carbonate (Na ₂ CO ₃ ) aqueous solution, potassium carbonate aqueous solution (K ₂ CO ₃ ), sodium hydroxide (NaOH) aqueous solution, tetramethylammonium hydride (TMAH) solution, and the like. Alkali aqueous solution is mentioned. Among these aqueous alkali solutions, in manufacture of a printed wiring board, the surface of the reliability of a board|substrate, or the surface of a work environment, the aqueous solution of weakly alkaline sodium carbonate or potassium carbonate is used normally. Therefore, in the photosensitive resin composition for printed wiring boards, it becomes very important that it can develop with weakly alkaline aqueous sodium carbonate solution etc.

Conventionally, in order to express the coating-film characteristic which satisfy|filled various requests|requirements, selecting appropriately the kind of resin used for the photosensitive resin composition is performed. In particular, it is difficult to achieve both developability and hardening properties in aqueous alkali solution, and development with a slightly alkaline aqueous solution of sodium carbonate or the like may not be possible depending on the type of resin, even if it is aimed at imparting properties. For example, when applying a polyimide resin or polyamide-imide resin containing an imide ring for the purpose of improving heat resistance, mechanical properties and heat resistance are excellent due to the structure, but the composition is applied to development with an aqueous sodium carbonate solution It is often difficult to do. In the Example of patent document 1 which disclosed the invention regarding the photosensitive resin composition containing polyimide resin, this point WHEREIN: It can also be understood from the point which is developing with strongly alkaline aqueous sodium hydroxide solution.

Conventionally, imparting developability to these polyimide resins and polyamideimide resins has been studied. However, in order to impart developability, it is necessary to respond by significantly sacrificing mechanical properties peculiar to imides.

Moreover, the circuit design of a printed wiring board is also becoming more complicated with high functionalization of a device. For example, a board|substrate with a high circuit thickness is currently used in vehicle-mounted board|substrates, board|substrates for power supply of various devices, etc., and there exists a background that wiring pitch is becoming small in addition to this. Therefore, let alone embedding between circuits, since the thickness of a soldering resist changes greatly between a circuit top and a circuit, control of the patterning by alkali development is becoming difficult. That is, since the solder resist is thin on the circuit and the solder resist becomes thick between circuits, if the photocuring condition is set in the thin film part, deep curing failure occurs in the thick film part. There is a problem in that it cannot be opened due to halation.

Furthermore, in the case of a circuit design with a high circuit thickness as described above, since the conventional solder resist expresses the hiding property of the coating film by the colored pigment, and the hiding property is different depending on the concentration of the coloring pigment in the coating film, There is a problem that light and shade are generated within the same substrate. That is, since the thick part exhibits high hiding property, whereas the thin film part on a circuit etc. has low concealability, the phenomenon that a circuit edge part shows-through is often seen especially. In order to solve the shading within such a surface, it is common to adjust the pigment concentration in a composition normally, but photosensitivity may be impaired, and it is a situation that there is a limit in order to adapt to the photosensitive resin composition of an alkali developing type.

Japanese Patent Laid-Open No. 2004-317725

Therefore, an object of the present invention is to solve the various problems described above, to obtain a cured product excellent in photosensitivity and alkali developability, and excellent in mechanical properties such as heat resistance, and at the same time, the hiding property of the coating film can be achieved by circuit design. It is to provide the photosensitive thermosetting resin composition which does not depend on the film thickness difference, a dry film, and the printed wiring board using them.

MEANS TO SOLVE THE PROBLEM The present inventors earnestly examined for the said objective realization. As a result, it came to solve the said cancellation|release by using the refractive index change at the time of hardening, without relying only on the coloring pigment for providing the hiding property with respect to a cured coating film.

That is, with respect to the coating film of the photosensitive resin composition, by maintaining the pigment concentration and transparency that can be photocured to the deep part during exposure to which the photocurability is affected, and by changing the refractive index of the coating film during thermal curing after development, in the cured coating film It was found that a uniform hiding property without in-plane variation was expressed.

More specifically, a photosensitive thermosetting resin composition using a polyamideimide resin having a specific structure solves the problems of mechanical properties and developability described above, and furthermore, such a polyamideimide resin and a thermosetting cyclic ether group-containing compound, unsaturated According to the composition comprising a resin having a double bond and a carboxyl group, and a photopolymerization initiator, the photocurability and hiding properties of the thermosetting cured coating film are improved, and uniform hiding properties without in-plane variation in the cured coating film are obtained. , came to complete the present invention.

That is, the photosensitive thermosetting resin composition of the present invention,

(A) alkali-soluble polyamideimide resin;

(B) a resin having an unsaturated double bond and a carboxyl group,

(C) a thermosetting cyclic ether group-containing compound, and

(D) a photopolymerization initiator;

The polyamideimide resin (A) wherein the alkali-soluble polyamideimide resin has 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.)

It is characterized in that it contains.

In the photocurable thermosetting resin composition of this invention, it is preferable that the mass average molecular weight Mw of the said polyamideimide resin (A) is 20,000 or less. Furthermore, it is preferable that the said photoinitiator (D) contains the photoinitiator which functions also as a photobase generator.

Moreover, the dry film of this invention has a resin layer containing the said photosensitive thermosetting resin composition of this invention, It is characterized by the above-mentioned.

Moreover, the printed wiring board of this invention is equipped with the hardened|cured material formed using the said photosensitive thermosetting resin composition of this invention, or the said dry film of this invention, It is characterized by the above-mentioned.

ADVANTAGE OF THE INVENTION According to this invention, it is excellent in photosensitivity and alkali developability (developability by weak alkali aqueous solution), and obtains the hardened|cured material excellent in mechanical properties, such as heat resistance, and at the same time, the hiding property of a coating film is film thickness difference by circuit design. It is possible to provide a photosensitive thermosetting resin composition, a dry film, and a printed wiring board that do not depend on

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

The photosensitive thermosetting resin composition of the present invention contains (A) an alkali-soluble polyamideimide resin, (B) a resin having an unsaturated double bond and a carboxyl group, (C) a thermosetting cyclic ether group-containing compound, and (D) a photopolymerization initiator, ,

The polyamideimide resin in which the alkali-soluble polyamideimide resin (A) has 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.) characterized by being.

As described above, the conventional solder resist expresses the hiding property of the coating film by the colored pigment, and the hiding property is different in the concentration of the colored pigment in the coating film. In the circuit board having a high circuit thickness, Since the thick film portion (inter-circuit) exhibits high hiding properties, while the thin film portions such as on circuits have low hiding properties, a phenomenon in which the circuit edge portion is particularly transparent occurred.

The photosensitive thermosetting resin composition of the present invention comprises a specific (A) alkali-soluble polyamideimide resin containing an aliphatic unit and a carboxyl group derived from a dimer acid, (B) a resin having an unsaturated double bond and a carboxyl group, (C) thermosetting The structure using a cyclic ether group containing compound has the greatest characteristic. With such a configuration, the pigment concentration and transparency that can be cured to the deep part are maintained during exposure that affects the photocurability, and the refractive index of the coating film is changed during thermal curing after development, so that in-plane variation in the cured coating film It is possible to obtain the effect of expressing a uniform hiding property without That is, to obtain a photosensitive thermosetting resin composition which has good resolution, and the hiding property of the coating film does not depend on the film thickness difference due to circuit design, is excellent in photosensitivity and alkali developability, and is excellent in mechanical properties such as heat resistance. It became possible.

Hereinafter, each component which comprises the photosensitive thermosetting resin composition of this invention is demonstrated in detail.

[(A) Alkali-soluble polyamideimide resin]

Curable resin composition of this invention WHEREIN: As alkali-soluble polyamide-imide resin, the polyamide-imide resin which has a structure represented by the following general formula (1) and a structure represented by the following general formula (2) is used. Thereby, developability can further be improved.

Here, X ₁ is a residue of an aliphatic diamine (a) derived from a dimer acid having 24-48 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 has excellent alkali solubility that can be dissolved even when a mild alkali solution such as an aqueous solution of 1.0 mass % sodium carbonate 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.

The 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, the dimer diamine (a) which is an aliphatic diamine derived from a dimer acid is obtained by, for example, polymerizing unsaturated fatty acids, such as oleic acid and linoleic acid, to set it as a dimer acid, reducing this and then aminating. As such an aliphatic diamine, commercial items, such as PRIAMINE 1073, 1074, 1075 (the Croda Japan company make, brand name) which are diamine which have a C36 frame|skeleton, can be used, for example. It may be preferable that the dimer diamine (a) is derived from a dimer acid having 28 to 44 carbon atoms, and it may be more preferable that the dimer diamine (a) is 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. Content (unit: mass %) of dimer diamine (a) from the viewpoint of improving the balance between alkali solubility of polyamideimide resin and other properties such as mechanical properties of a cured product of a resin composition containing polyamideimide resin 20-60 mass % of silver is preferable, and 30-50 mass % is more preferable. In the present specification, "content of dimer diamine (a)" refers to the amount of the dimer diamine (a) that can be positioned as one of the raw materials at the time of manufacturing polyamideimide resin, produced polyamideimide resin means the ratio to the mass of Here, "the mass of the polyamide-imide resin produced" is, from the input amount of all raw materials for producing the polyamide-imide resin, water (H ₂ O) generated by imidization and carbon dioxide gas (CO _{2) generated by amidation.} ) minus the theoretical quantity.

From a viewpoint of improving the alkali solubility of polyamideimide resin, 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 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 aromatic ring and the cyclohexane ring in the portion represented by Y As for the quantitative relationship, it is preferable that the molar ratio with respect to content of the aromatic ring of content of a cyclohexane ring is 85/15-100/0, It is more preferable that it is 90/10-99/1, It is 90/10-98/2 more preferably.

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) (also referred to as “another diamine (f)” in this specification), and Y is the above general formula Like (1) and the said General formula (2), it is an aromatic ring or a cyclohexane ring each independently. The other 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, A well-known and usual method can be used and it can manufacture through an imidation process and an amidimidization process.

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) are used. 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 an amount in which the content of the dimer diamine (a) is 20 to 60 mass%, and the amount in which the content of the dimer diamine (a) is 30 to 50 mass% is more desirable. 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 cyclohexane-1,2,4-tricarboxylic acid-1,2-anhydride (c) in the imidation process from a viewpoint of improving the alkali solubility of 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.

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

In the amidimidization step, a polyamideimide resin containing a substance having a structure represented by the following general formula (3) is obtained by reacting the diisocyanate compound (e) with the imidized product obtained in the above imidization step.

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, dicyclohexyl methane diisocyanate, isophorone diisocyanate, norbornene diisocyanate, etc. are mentioned. From the viewpoint of improving both the alkali solubility of the polyamideimide resin and the transparency of the polyamideimide resin, the diisocyanate compound (e) preferably contains an aliphatic isocyanate, and the diisocyanate compound (e) is more preferably an aliphatic isocyanate. desirable.

The usage-amount of the diisocyanate compound (e) in the amidimidization 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 preferably 0.3 or more and 1.0 or less as a molar ratio to the amount of the diamine compound used to obtain the imide compound, It is more preferable to set it as 0.4 or more and 0.95 or less, and 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 said general formula (3), each independently X is a diamine residue (residue of a diamine compound), Y is each independently an aromatic ring or a cyclohexane ring, and Z is a residue of a diisocyanate compound. n is a natural number.

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. From a viewpoint, it is preferable that the acid value is 50 mgKOH/g or more, It is more preferable that it is 50-200 mgKOH/g, It is still more preferable that it is 70-130 mgKOH/g. When the acid value is 50 mgKOH/g or more, solubility in alkali increases, developability becomes good, and furthermore, since the degree of crosslinking with the thermosetting component after light irradiation increases, sufficient development contrast can be obtained. On the other hand, if the acid value is 200 mgKOH/g or less, accurate pattern drawing becomes easy.

Further, in consideration of developability and cured coating film properties, 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. When molecular weight is 20,000 or less, alkali solubility of an unexposed part increases and developability improves. On the other hand, when the molecular weight is 1,000 or more, sufficient develop resistance and curing properties can be obtained in the exposed portion.

[(B) Resin having an unsaturated double bond and a carboxyl group]

As resin which has an unsaturated double bond and a carboxyl group, the compound (any of an oligomer and a polymer may be sufficient) listed below is mentioned.

(1) Dial alcohol compounds containing diisocyanates such as aliphatic diisocyanate, branched aliphatic diisocyanate, alicyclic diisocyanate, and aromatic diisocyanate and carboxyl groups such as dimethylolpropionic acid and dimethylolbutanoic acid, polycarbonate-based polyols, polyols Carboxyl groups by polyaddition reaction of diol compounds such as ether polyols, polyester polyols, polyolefin polyols, acrylic polyols, bisphenol A alkylene oxide adduct diols, compounds having phenolic hydroxyl groups and alcoholic hydroxyl groups Contains photosensitive urethane resin.

(2) Diisocyanate and bifunctional epoxy resins such as bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bixylenol type epoxy resin, and biphenol type epoxy resin of (meth)acrylate or its partial acid anhydride-modified product, and a carboxyl group-containing photosensitive urethane resin by polyaddition reaction of a carboxyl group-containing dialcohol compound.

(3) A carboxyl group-containing photosensitive resin in which (meth)acrylic acid is reacted with a bifunctional or higher polyfunctional (solid) epoxy resin, and dibasic acid anhydride is added to a hydroxyl group present in a side chain.

(4) A carboxyl group-containing photosensitive resin in which (meth)acrylic acid is reacted with a polyfunctional epoxy resin obtained by further epoxidizing the hydroxyl group of a bifunctional (solid) epoxy resin with epichlorohydrin, and dibasic acid anhydride is added to the generated hydroxyl group .

(5) An unsaturated group-containing monocarboxylic acid is reacted with a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in one molecule with an alkylene oxide such as ethylene oxide or propylene oxide or a cyclic carbonate compound, A carboxyl group-containing photosensitive resin obtained by further reacting the reaction product with a polybasic acid anhydride.

(6) In one or more copolymers of an unsaturated carboxylic acid such as (meth)acrylic acid and a compound having an unsaturated double bond other than that, a compound having an epoxy group and an unsaturated double bond, (meth)acrylic acid chloride, etc. A carboxyl group-containing photosensitive resin obtained by adding an unsaturated group as a pendant.

(7) Carboxyl group-containing photosensitive resin formed by adding a compound having one epoxy group and one or more (meth)acryloyl group to the resin of (1) to (6) above in one molecule.

These (B) components may be used individually by 1 type, and may be used in combination of 2 or more type.

Preferably the compounding quantity of (B) component in the photosensitive thermosetting resin composition of this invention is 5-150 mass parts with respect to 100 mass parts of (A) polyamideimide resin, More preferably, it is 10-80 mass parts. (B) By making the compounding quantity of a component into the said range, the improvement of the developability in an exposed part and securing of the developability in an unexposed part become compatible favorably.

[(C) Thermosetting Cyclic Ether Group-Containing Compound]

A thermosetting cyclic (thio) ether group-containing compound is a compound which has a 3, 4 or 5-membered cyclic ether group, or any one or two types of cyclic thioether group in a molecule|numerator, For example, an epoxy resin, oxetane A compound, episulfide resin, etc. are mentioned.

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 an epoxy 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.

Examples of the oxetane compound include bis[(3-methyl-3-oxetanylmethoxy)methyl]ether, bis[(3-ethyl-3-oxetanylmethoxy)methyl]ether, and 1,4-bis[(3- methyl-3-oxetanylmethoxy)methyl]benzene, 1,4-bis[(3-ethyl-3-oxetanylmethoxy)methyl]benzene, (3-methyl-3-oxetanyl)methylacrylate, (3-ethyl-3-oxetanyl)methyl acrylate, (3-methyl-3-oxetanyl)methyl methacrylate, (3-ethyl-3-oxetanyl)methyl methacrylate or an oligomer thereof; or In addition to polyfunctional oxetanes such as copolymers, oxetane alcohol, novolak resin, poly(p-hydroxystyrene), cardo-type bisphenol, calixarene, calixresorcinarene, or silsesquioxane, etc. an etherified product with a resin having a hydroxyl group of In addition, the copolymer etc. of the unsaturated monomer which have an oxetane ring, and alkyl (meth)acrylate are mentioned.

Examples of the episulfide resin include YL7000 (bisphenol A episulfide resin) manufactured by Mitsubishi Chemical Corporation. Moreover, the episulfide resin etc. which substituted the oxygen atom of the epoxy group of the novolak-type epoxy resin with the sulfur atom using the same synthetic|combination method can also be used.

These (C) thermosetting cyclic ether group containing compounds may be used individually by 1 type, and may be used in combination of 2 or more type.

In the photosensitive thermosetting resin composition of the present invention, the compounding amount of the thermosetting cyclic ether group-containing compound (C) is preferably a ratio of the thermosetting cyclic ether group equivalent to the carboxylic acid equivalent of the total of the (A) component and the (B) component. The amount is in the range of 0.2 to 3.0, more preferably 0.5 to 2.0.

[(D) Photoinitiator]

As the photopolymerization initiator (D) used in the present invention, a well-known and usual thing can be used, and especially when using it for the heating (PEB) process after light irradiation mentioned later, the photoinitiator which also has a function as a photobase generator is suitable. In addition, when performing a heating process after exposure, you may use a photoinitiator and a photobase generator together.

The photopolymerization initiator, which also functions as a photobase generator, is a catalyst for polymerization of (C) a thermosetting cyclic ether group-containing compound as a heat-reactive compound by changing the molecular structure or cleaving the molecule by irradiation with light such as ultraviolet light or visible light. A compound that produces one or more basic substances that can function as 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 α-aminoacetophenone compounds, oxime ester compounds, acyloxyimino groups, N-formylated aromatic amino groups, N-acylated aromatic amino groups, and nitrobenzylcarps. The compound etc. which have substituents, such as a barmate 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-based compound may have a benzoin ether bond in the molecule, cleavage occurs within the molecule when irradiated with light, and a basic substance (amine) that exhibits a curing catalytic action is produced. Irgacure 907, Irgacure 369, Irgacure 379 by BASF Japan, etc. are mentioned as (alpha)-aminoacetophenone type compound as a commercial item.

As the oxime ester-based compound, any compound that generates a basic substance upon irradiation with light can be used. As such an oxime ester compound, CGI-325 by BASF Japan, Irgacure OXE01, Irgacure OXE02, N-1919 by ADEKA Corporation, NCI-831 etc. are mentioned as a commercial item. Moreover, the photoinitiator which has two oxime ester groups in a molecule|numerator can also be used suitably.

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 (A) polyamideimide resin, More preferably, it is 0.3-20 mass parts. When it is 0.1 mass part or more, the contrast of developability of a light irradiated part and an 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 mix|blended with the photosensitive thermosetting resin composition of this invention as needed.

(monomers with unsaturated double bonds)

The monomer which has a well-known unsaturated double bond for the purpose of the improvement of photoreactivity can be mix|blended with the resin composition of this invention. As a monomer having such an unsaturated double bond, commonly known polyester (meth) acrylate, polyether (meth) acrylate, urethane (meth) acrylate, carbonate (meth) acrylate, epoxy (meth) acrylate, etc. can be heard Specifically, hydroxyalkyl acrylates, such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; diacrylates of glycols such as ethylene glycol, polyethylene glycol and propylene glycol; Polyhydric alcohols such as hexanediol, trimethylolpropane, pentaerythritol, dipentaerythritol, and tris-hydroxyethyl isocyanurate, ethylene oxide adducts, propylene oxide adducts, ε-caprolactone adducts, etc. of polyvalent acrylates; polyvalent acrylates such as phenoxyacrylate, bisphenol A diacrylate, and ethylene oxide adducts or propylene oxide adducts of these phenols; polyvalent acrylates of glycidyl ethers such as glycerin diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, and triglycidyl isocyanurate; and at least any one kind of each methacrylate corresponding to the acrylate.

(polymer resin)

A well-known and usual polymer resin can be mix|blended with the resin composition of this invention 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, polyvinyl acetal-based, polyvinyl butyral-based, block copolymers, and elastomers. This polymeric resin may be used individually by 1 type, and may use 2 or more types together.

(inorganic filler)

An inorganic filler can be mix|blended with the resin composition of this invention in order to suppress cure shrinkage of hardened|cured material, and to improve characteristics, such as adhesiveness and hardness. 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 Silicious Earth. and the like.

(coloring agent)

A well-known and usual coloring agent can be mix|blended with the resin composition of this invention. As the colorant, commonly known colorants such as red, blue, green, yellow, white, and black can be used, and any of pigments, dyes and dyes may be used.

(organic solvent)

An organic solvent can be used for the resin composition of this invention for the purpose of 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 optional ingredients)

Components, such as a mercapto compound, an adhesion promoter, antioxidant, and a ultraviolet absorber, can be mix|blended with the resin composition of this invention further as needed. These can use a well-known and customary thing in the field|area of an electronic material. In addition, well-known and usual thickeners such as finely divided silica, hydrotalcite, organic bentonite, and montmorillonite, defoaming agents such as silicone, fluorine, and polymer, and/or leveling agents, silane coupling agents, rust inhibitors, etc. can

The photosensitive thermosetting resin composition of the present invention is excellent in photosensitivity and alkali developability, and excellent in mechanical properties such as heat resistance. It can use widely in the field|area of a printed wiring board, For example, it can use as uses, such as the soldering resist of the object for packages, the object for vehicle mounting, the object for motherboards, and printed wiring boards for flexible objects.

(dry film)

The dry film of this invention can be manufactured as follows.

That is, first, on a carrier film (support), the resin composition of the present invention is diluted with an organic solvent, adjusted to an appropriate viscosity, and sequentially applied by a known method such as a comma coater according to a conventional method. Then, the dry film which has the resin layer formed on the carrier film can be obtained by drying at the temperature of 50-130 degreeC for 1 to 30 minutes normally. Moreover, according to the objective, it is good also as a multilayer structure by laminating|stacking other photosensitive resin compositions. On the dry film thus formed, a further peelable cover film can be laminated for the purpose of preventing dust from adhering to the surface of the film. A conventionally well-known plastic film can be used suitably as a carrier film and a cover film, About a cover film, when peeling a cover film, it is preferable that it is a thing 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.

(Printed wiring board and its manufacturing method)

The printed wiring board of this invention is characterized by the point provided with the hardened|cured material formed using the photosensitive thermosetting resin composition of the said this invention, or the dry film of the said this invention. The photosensitive thermosetting resin composition of the present invention has excellent photosensitivity, alkali developability, heat resistance, and mechanical properties, and has the advantage of excellent hiding properties of a coating film that does not depend on a difference in height of a circuit.

The production of the printed wiring board of the present invention is a step of forming a resin layer containing the photosensitive thermosetting resin composition of the present invention on a printed wiring board on which a conductor circuit is formed (resin layer formation step), and applying an active energy ray to the resin layer. It is a manufacturing method including the process (exposure process) of irradiating in pattern shape, the process of alkali-developing this resin layer, and forming the patterned resin layer collectively (development process). If necessary, after alkali development, further photocuring or thermosetting (post-curing process) is performed, the resin layer can be completely cured, and a highly reliable printed wiring board can be obtained.

In addition, manufacture of the printed wiring board of this invention can also be performed according to the following procedure. That is, a step of forming a resin layer containing the photosensitive thermosetting resin composition of the present invention on a printed wiring board on which a conductor circuit is formed (resin layer formation step), a step of irradiating the resin layer with an active energy ray in a pattern ( exposure step), a step of heating the resin layer as necessary (heating (PEB) step), and alkali development of the resin layer to form a patterned resin insulating layer (development step). . After alkali development, further photocuring and thermosetting (post-curing process) are performed, the resin layer can be completely hardened, and a highly reliable printed wiring board can be obtained. In particular, in the present invention, it is preferable to use this procedure.

Hereinafter, each process is demonstrated in detail.

[resin layer forming process]

At this process, at least one resin layer containing the photosensitive thermosetting resin composition of this invention is formed on a printed wiring board.

As a formation method of a resin layer, the application|coating method and the lamination method are mentioned. In the case of the coating method, the resin composition of this invention is apply|coated on a printed wiring board by methods, such as screen printing, and a resin layer is formed by drying. In the case of the lamination method, first, the resin composition of this invention is diluted with the organic solvent, and it adjusts to an appropriate viscosity, It apply|coats and dries on a carrier film, and produces the dry film which has a resin layer. Next, it joins so that a resin layer may contact with a printed wiring board with a laminator etc., and a resin layer is formed. The carrier film is peeled off before the developing process.

Moreover, another layer can be interposed between the photosensitive thermosetting resin layer of this invention and a printed wiring board. It is preferable that the other layer contains an alkali developing type photosensitive resin composition. As an alkali developing type photosensitive resin composition, a well-known composition can be used, For example, the well-known composition for soldering resists can be used. Thus, by setting it as the laminated structure including other layers, the hardened|cured material excellent in impact resistance and flexibility can be obtained.

[Exposure process]

In this step, light is irradiated in a negative pattern to activate the photopolymerization initiator contained in the resin layer to cure the light-irradiated portion. In this process, the photosensitive resin component contained in the resin composition is superposed|polymerized by the radical which generate|occur|produced in the light irradiation part, and it becomes insoluble in a developing solution. Moreover, in the case of a photobase generator and the composition containing the photoinitiator functioning also as a photobase generator, a base generate|occur|produces in a light irradiation part in this process.

As the light irradiator, a direct drawing device, a light irradiator equipped with a metal halide lamp, or the like can be used. The mask for light irradiation on the pattern is a negative type mask.

As an active energy ray used for light irradiation, 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. Any of a gas laser and a solid-state laser may be sufficient as long as the laser beam of this range is used. In addition, although the amount of light irradiation varies with the film thickness etc., it can be generally 100-1500 mJ/cm<2>.

[Heating (PEB) process]

If necessary, a heating (PEB) process may be added. In this step, in a composition containing a photobase generator and a photopolymerization initiator functioning also as a photobase generator, the thermally reactive compound reacts with the base generated in the light irradiation part in the light irradiation step, and the alkali development resistance of the irradiation part is improved do. The heating temperature is, for example, 80 to 140°C. The heating time is, for example, from 1 to 100 minutes.

Since the reaction of the resin composition in this step is, for example, a ring-opening reaction of a thermosetting cyclic ether group-containing compound by a thermal reaction, deformation and curing shrinkage can be suppressed compared to the case where curing proceeds by a photoradical reaction. there is. Moreover, the alkali development tolerance of a light irradiation part improves significantly by the carboxyl group of a resin composition reacting and reducing.

[Development process]

The developing step removes the unirradiated portion by alkali development to form an insulating film on a negative pattern, particularly a solder resist pattern.

As a developing method, it can depend on well-known methods, such as dipping. Moreover, as a developing solution, aqueous alkali solutions, such as sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, amines, tetramethylammonium hydroxide aqueous solution (TMAH), or these mixtures can be used. Here, by using the specific polyamideimide resin as described above in the present invention, there is an advantage in that it can be developed with, for example, 0.3 to 3% by mass of a weakly alkaline developer.

[Post-curing process]

This process thermosets the resin layer completely after the image development process, and obtains a highly reliable coating film. The heating temperature is, for example, 140°C to 180°C. Moreover, you may light-irradiate before or after post-curing.

Example

Hereinafter, the present invention will be described in more detail by way of Examples and Comparative Examples, but the present invention is not limited by these Examples and Comparative Examples.

(Synthesis Example 1)

28.61 g (0.052 mol) of an aliphatic diamine derived from a dimer acid having 36 carbon atoms as the dimer diamine (a) (product name PRIAMINE 1075, manufactured by Croda Japan) in a 4-neck 300 mL flask equipped with a nitrogen gas introduction tube, a thermometer, and a stirrer. ), 4.26 g (0.028 mol) of 3,5-diaminobenzoic acid as the carboxyl group-containing diamine (b), and 85.8 g of γ-butyrolactone were introduced and dissolved at room temperature.

Subsequently, 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 it maintained at room temperature for 30 minutes. Furthermore, 30 g of toluene was thrown in, it heated up to 160 degreeC, and after 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 a diisocyanate compound (e) is added to the solution containing the obtained imidide, hold|maintained at the temperature of 160 degreeC for 32 hours, and diluting 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 the dimer diamine (a) (product name PRIAMINE 1075, manufactured by Croda Japan) in a 4-necked 300 mL flask equipped with a nitrogen gas inlet tube, a thermometer, and a stirrer. ), 4.02 g (0.026 mol) of 3,5-diaminobenzoic acid as the carboxyl group-containing diamine (b), and 73.5 g of γ-butyrolactone were charged and dissolved at room temperature.

Then, 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 thrown in, and it hold|maintained at room temperature for 30 minutes. Furthermore, 30 g of toluene was thrown in, it heated up to 160 degreeC, and after 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.

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

(Synthesis Example 3)

29.49 g (0.054 mol) of an aliphatic diamine derived from a dimer acid having 36 carbon atoms as the dimer diamine (a) (product name PRIAMINE 1075, manufactured by Croda Japan) in a 4-necked 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 carboxyl group-containing diamine (b), and 75.0 g of γ-butyrolactone were charged and dissolved at room temperature.

Next, 33.29 g (0.168 mol) of cyclohexane-1,2,4-tricarboxylic acid anhydride (c) was charged, and the mixture was maintained at room temperature for 30 minutes. Furthermore, 30 g of toluene was thrown in, it heated up to 160 degreeC, and after 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.

To the solution containing the obtained imidide, 16.79 g (0.064 mol) of dicyclohexylmethane diisocyanate as the diisocyanate compound (e) was added, maintained at a temperature of 160° C. for 32 hours, and diluted with 37.5 g of cyclohexanone. Thus, a solution (A-3) containing polyamideimide resin was obtained. The weight average molecular weight Mw of the obtained polyamideimide resin was 6430, solid content was 41.2 mass %, acid value was 63 mgKOH/g, and content of dimer diamine (a) was 39.3 weight%.

(Comparative Example Synthesis Example 1)

In a flask equipped with a stirrer, thermometer and condenser, 848.8 g of GBL (gamma-butyrolactone), 57.5 g (0.23 mol) of MDI (diphenylmethane diisocyanate), DMBPDI (4,4'-diisocyanate-3,3) '-Dimethyl-1,1'-biphenyl) 59.4 g (0.225 mol) and TMA (trimellitic anhydride) 67.2 g (0.35 mol) and TMA-H (cyclohexane-1,3,4-tricarboxylic acid) -3,4-anhydride) 29.7 g (0.15 mol) was added, the temperature was raised to 80° C. with attention to exotherm while stirring, and dissolved and reacted at this temperature over 1 hour, and further 160 over 2 hours After raising the temperature to °C, the reaction was carried out at this temperature for 5 hours. The reaction proceeded with the foaming of carbon dioxide gas, and the inside of the system became a brown transparent liquid. A solution of polyamideimide resin (A1) (resin composition in which the resin is dissolved in γ-butyrolactone) having a viscosity at 25°C of 7 Pa·s, 17% resin solids, and a solution acid value of 5.3 (KOH mg/g) was prepared. got it In addition, the solid content acid value of resin was 31.2 (KOHmg/g). In addition, as a result of the measurement of gel permeation chromatography (GPC), the weight average molecular weight was 34000.

(Examples 1 to 5, Comparative Examples 1 to 3)

According to the formulations described in the table below, the materials described in Examples and Comparative Examples were respectively blended, premixed with a stirrer, and kneaded with a three roll mill to prepare a photosensitive thermosetting resin composition. In addition, unless otherwise indicated, the value of the compounding quantity in a table|surface shows the mass part of solid content.

<Optimal exposure dose>

A circuit pattern board having a copper thickness of 70 µm and polyimide 50 µm is micro-etched with sulfuric acid and water, washed with water and dried, then each photosensitive thermosetting resin composition is applied to the entire surface by screen printing, followed by hot air at 80 ° C. It was dried in a circulation drying furnace for 30 minutes. Exposure was performed through a step tablet (Kodak No. 2) using an exposure apparatus (EXP-2960) equipped with a mercury short arc lamp, and development (30 ° C, 0.2 MPa, 1 wt% Na ₂ CO ₃ aqueous solution) was performed in 60 seconds. The optimal exposure amount was set when the pattern of the step tablet remaining at the time was 7 steps.

<Circuit Concealment>

A circuit pattern substrate having a copper circuit/space of 300 µm/300 µm, a copper circuit thickness of 70 µm, and a polyimide substrate thickness of 50 µm was prepared, and after micro-etching with sulfuric acid and water, washing and drying were performed. The photosensitive resin compositions of Examples and Comparative Examples were applied by screen printing and dried in a hot air circulation drying furnace at 80° C. for 30 minutes. After drying, using the exposure apparatus (EXP-2960) equipped with a mercury short arc lamp, whole surface exposure was performed with the optimal exposure amount of each photosensitive thermosetting resin composition. After exposure, it developed with 30 degreeC 1 mass % sodium carbonate aqueous solution, and obtained the cured coating film by thermosetting for 150 degreeC x 60 minutes.

The appearance of the circuit board covered with the obtained cured coating film was confirmed, and the following index|indexes evaluated concealability.

A: The appearance of a copper circuit and an edge is uniform, and the color of copper is not seen through.

B: Appearance unevenness due to the difference in film thickness on the circuit is confirmed.

C: The circuit edge part is transparent, and it looks like a defect.

<Resolution>

A circuit pattern substrate having a copper circuit/space of 300 µm/300 µm, a copper circuit thickness of 70 µm, and a polyimide substrate thickness of 50 µm was prepared, and after micro-etching with sulfuric acid and water, washing and drying were performed. The photosensitive resin compositions of Examples and Comparative Examples were applied by screen printing and dried in a hot air circulation drying furnace at 80° C. for 30 minutes. After drying, it exposed using the exposure apparatus (EXP-2960) equipped with a mercury short arc lamp. For the exposure pattern, a negative mask capable of forming a line of 100/120/150/μm in the space portion of the substrate was used. The exposure dose investigated the optimal exposure dose of each photosensitive thermosetting resin composition. After exposure, it developed with 30 degreeC 1 mass % sodium carbonate aqueous solution, a pattern was drawn, and the cured coating film was obtained by thermosetting for 150 degreeC x 60 minutes.

It calculated|required using the optical microscope which adjusted the minimum residual line of the cured coating film of the obtained photosensitive resin composition for soldering resists to 200 times.

A: A solder dam of 100 µm is formed between copper circuits.

B: A solder dam of 120 µm is formed between copper circuits.

C: A 150 µm solder dam is formed between copper circuits.

<Insulation Reliability>

A comb-type circuit pattern substrate for insulation reliability evaluation having a copper circuit/space of 100 µm/100 µm, a copper circuit thickness of 70 µm, and a polyimide substrate thickness of 50 µm was prepared, micro-etched with sulfuric acid and water, washed with water, and dried was done. The photosensitive resin compositions of Examples and Comparative Examples were applied by screen printing and dried in a hot air circulation drying furnace at 80° C. for 30 minutes. After drying, using the exposure apparatus (EXP-2960) equipped with a mercury short arc lamp, whole surface exposure was performed with the optimal exposure amount of each photosensitive thermosetting resin composition. After exposure, it developed with 30 degreeC 1 mass % sodium carbonate aqueous solution, and obtained the cured coating film by thermosetting for 150 degreeC x 60 minutes.

The voltage of 100V was applied to the obtained board|substrate for insulation reliability evaluation under 85 degreeC and 85RH% environment, and the insulation reliability after 1000 hours was confirmed with the following index|index.

A: No migration and no short circuit after 1000 hours.

B: There is no short circuit after 1000 hours, but there is occurrence of migration.

C: Short circuit occurred after 1000 hours.

<Solder heat resistance>

A circuit pattern substrate having a copper thickness of 70 µm and a polyimide thickness of 50 µm is buff roll polished, washed with water and dried, and then each photosensitive thermosetting resin composition is applied to the entire surface by screen printing, and hot air circulation at 80 ° C. It was dried in a type drying furnace for 30 minutes. After drying, pattern exposure was performed with the optimal exposure amount of each photosensitive thermosetting resin composition using the exposure apparatus (EXP-2960) equipped with a mercury short arc lamp. After exposure, it developed with 30 degreeC 1 mass % sodium carbonate aqueous solution, and obtained the cured coating film by thermosetting for 150 degreeC x 60 minutes.

A rosin-based flux was applied to the obtained evaluation substrate, immersed in a solder bath previously set at 260° C. for 10 seconds, the flux was washed with denatured alcohol, and then the expansion and peeling of the resist layer was evaluated by a tape peeling test. The judgment criteria are as follows.

A: Even if it repeats immersion twice for 10 second and performs a peeling test with a cellophane tape, peeling is not recognized.

B: Even if immersion is performed once for 10 seconds and a peeling test is performed with a cellophane tape, peeling is not recognized.

C: When immersion is performed for 10 seconds, the resist layer has swelling and peeling.

<Flexibility test (existence of cracks)>

The circuit pattern board|substrate which consists of polyimide thickness 25 micrometers and copper thickness 18 micrometers was prepared, and it pre-processed using CZ-8100 by Mack Corporation. On this circuit pattern board, each photosensitive thermosetting resin composition was apply|coated to the whole surface by the screen printing method, and it was made to dry in 80 degreeC hot air circulation type drying furnace for 30 minutes. Then, it dried at 90 degreeC/30 minutes in a hot-air circulation type drying furnace, and the film containing the photosensitive thermosetting resin composition was formed.

With respect to the board|substrate provided with the film obtained above, the whole surface was exposed at 500 mJ/cm<2> using the exposure apparatus equipped with a high-pressure mercury-vapor lamp (short arc lamp). Then, for Examples 1 to 5 and Comparative Examples 1, 2, and 3, after performing the PEB process at 90 ° C. for 30 minutes _{, using a 1 mass % Na 2} CO ₃ aqueous solution at 30 ° C., a spray pressure of 2 kg/cm 2 Development was performed for 5 minutes under the conditions. After that, hardening was performed at 150 degreeC for 60 minutes in the hot-air circulation type drying furnace, and the board|substrate provided with the cured film of the photosensitive thermosetting resin composition was produced.

The obtained board|substrate was cut|disconnected to about 50 mm x about 200 mm, and flexibility evaluation was performed using the cylindrical mandrel testing machine (BYK Gardner company, No.5710). The surface to which the resin composition was apply|coated was arrange|positioned to the outer side, it was bent centering on the mandrel of diameter 2mm, and the presence or absence of crack generation was evaluated.

The evaluation results are put together in Table 1 below and shown.

Comments *1 to 13 in the components shown in Table 1 above indicate the following.

*1) PAI-1: Polyamideimide resin of Synthesis Example 1

*2) PAI-2: Polyamideimide resin of Synthesis Example 2

*3) PAI-3: Polyamideimide resin of Synthesis Example 3

*4) PAI-4: Polyamideimide resin of Comparative Synthesis Example 1

*5) PCR-1170H: carboxyl group-containing modified phenol novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.), acid value 64 mgKOH/g, COOH equivalent 890

*6) M-350: Trimethylolpropane EO modified triacrylate (manufactured by Toagosei Co., Ltd.)

*7) 6MX75: Epoxy acrylate (Double bond, Doublemer 6MX75)

*8) 828: bisphenol A type epoxy resin, epoxy equivalent 190 (manufactured by Mitsubishi Chemical Co., Ltd.)

*9) IRGACURE 907: Alkylphenone-based photopolymerization initiator (manufactured by BASF)

*10) DETX-S: diethylthioxanthone (manufactured by Nippon Kayaku)

*11) IRGACURE OXE02: oxime-based photopolymerization initiator (manufactured by BASF)

*12) C.I. Pigment Blue 15:3

*13) C.I. Pigment Yellow 147

As is clear from the evaluation results shown in Table 1 above, good resolution is achieved by combining the components (A) polyamideimide resins PAI-1 to PAI-3 and (B) to (D) used in the resin composition of each Example. , and excellent circuit hiding properties are obtained with a change in refractive index after curing.

On the other hand, from Comparative Example 1, the polyamideimide resin PAI-4, which does not satisfy the requirements of the present invention, does not have an aliphatic unit derived from a dimer acid, and is excellent in heat resistance and insulation reliability, but is inferior in circuit hiding property and flexibility it can be seen that According to Comparative Examples 2 and 3, in the composition using a carboxyl group-containing epoxy acrylate resin without using a specific polyamideimide resin, the resolution and trade-off were improved by expressing poor heat resistance and insulation reliability and circuit hiding properties with a colorant. it can be seen that

Claims (5)

(A) alkali-soluble polyamideimide resin;
(B) a resin having an unsaturated double bond and a carboxyl group,
(C) a thermosetting cyclic ether group-containing compound, and
(D) photoinitiator
wherein said (A) alkali-soluble polyamide-imide resin is a polyamide-imide resin having a structure represented by the following general formula (1) and a structure represented by the following general formula (2), A photosensitive thermosetting resin composition.

(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 photosensitive thermosetting resin composition according to claim 1, wherein the polyamideimide resin (A) has a mass average molecular weight Mw of 20,000 or less. The photosensitive thermosetting resin composition of Claim 1 in which the said (D) photoinitiator contains the photoinitiator which also functions as a photobase generator. It has a resin layer containing the photosensitive thermosetting resin composition of Claim 1, The dry film characterized by the above-mentioned. Hardened|cured material formed using the photosensitive thermosetting resin composition in any one of Claims 1-3, or the dry film of Claim 4 is provided, The printed wiring board characterized by the above-mentioned.