JP5179407B2 - Photosensitive resin composition and circuit wiring board using the same - Google Patents

Description

  The present invention relates to a photosensitive resin composition containing a polyamic acid resin and a photopolymerization initiator and a circuit wiring board using the same, and more specifically, a resist composition for a printed wiring board and a printed wiring board. The present invention relates to a photosensitive resin composition containing a novel polyamic acid resin suitable for the purpose of forming a protective film and a circuit wiring board.

  In recent years, ultraviolet curable photosensitive resin compositions have been widely used in a wide range of fields such as paints, adhesives, and resists for various reasons such as high productivity, low pollution, and energy saving. Also in the field of processing printed wiring boards, various ink-type cover materials such as solder resist inks are being replaced by ultraviolet curable compositions from conventional screen printing methods.

  In addition, as the density and weight of the printed circuit board increase due to significant advances in electronic technology, the replacement of the printed wiring board from the conventional rigid (hard) board to the flexible board is progressing. So far, when using a photosensitive resin as a cover material for a rigid substrate, flexibility has not been so much required as a characteristic of the cover material after curing. However, when a cover material is used for a flexible substrate, in order to take advantage of the characteristics of the flexible substrate, the cover material is also required to have higher flexibility and bending resistance. If the cover material is low in flexibility and heat resistance, there are problems such as warping when laminated on the substrate and low flexibility, and the conventional photosensitive cover material can be applied to flexible substrates. There was a problem that there was a limit.

  Therefore, a resin composition for a cover material that has siloxane polyimide as a main component as a component exhibiting low elasticity has been proposed. Although the composition disclosed in Patent Document 1 has the advantage of suppressing warping of the substrate even after the heating step performed in the step of soldering the surface mount component (reflow step), it is expensive, There was a problem that the room temperature storage stability of the composition was poor.

  Patent Document 2 reports a photosensitive composition containing a polyamic acid resin having a specific siloxane moiety and an aromatic moiety having an unsaturated group. However, although this composition reduces the warpage of the substrate after curing, for example, a slide phone (a mobile phone that slides between two housings), which has been actively developed in recent years, a flexible substrate for HDD, etc. In addition, there is a problem in that the bending life is not sufficient when used in applications requiring higher bending resistance.

  In addition, if the resin composition for the cover material is cured and heated at a high temperature, it induces oxidation of metal wiring such as copper, thereby lowering the conduction performance, or the adhesion force generated by the formation of a fragile oxide layer. Development of a resin composition having a property that can be cured at a temperature range as low as possible has been desired due to adverse effects such as a decrease, a decrease in chemical resistance, and infiltration of a plating solution.

JP 2004-294882 A Republication 06-109514

  A first object of the present invention is a photosensitive resin composition in which a cured product has flexibility, has excellent bending resistance and heat resistance, and can suppress warping of a substrate on which the cured product is laminated as much as possible. The second object is to provide a circuit wiring board on which an insulating film excellent in flexibility and heat resistance is formed by using the photosensitive resin composition.

  As a result of intensive studies, the present inventors have found that a photosensitive resin composition containing a polyamic acid resin obtained by polymerizing a specific diamine and an acid anhydride can solve the above-mentioned problems. Completed the invention.

That is, the present invention
(A) a polyamic acid resin having a radical polymerizable unsaturated bond, and (B) a photosensitive resin composition containing a photopolymerization initiator,
(A) A component makes the raw material react the acid anhydride component containing an aromatic tetracarboxylic anhydride, and the diamine component which contains a dihydrazide compound in the ratio of 30-100 mol with respect to 100 mol of all the diamine components. A hydrazide bond-containing polyamic acid resin having a structural unit represented by the following general formula (1),
The photosensitive resin composition contains 0.5 to 20 parts by weight of the component (B) with respect to 100 parts by weight of the component (A).

（式中、Ａｒは芳香族テトラカルボン酸からカルボキシル基を除いた４価のテトラカルボン酸残基を示し、Ｒ_１は単結合又は脂肪族若しくは芳香族ジヒドラジドからヒドラジド基−ＣＯＮＨＮＨ_２を除いた２価の残基を示し、Ｘ_１及びＸ_２は独立に、ヒドロキシル基又はラジカル重合性の不飽和結合を有する１価の有機基を示す。）

(In the formula, Ar represents a tetravalent tetracarboxylic acid residue obtained by removing a carboxyl group from an aromatic tetracarboxylic acid, and R ₁ represents a single bond or _{2 obtained} by removing a hydrazide group —CONHNH ₂ from an aliphatic or aromatic dihydrazide. X ₁ and X ₂ independently represent a hydroxyl group or a monovalent organic group having a radical polymerizable unsaturated bond.

  In the photosensitive resin composition of the present invention, the raw material diamine component contains a dihydrazide compound and an aromatic diamine having a radical polymerizable unsaturated bond, and the molar ratio of the dihydrazide compound to the aromatic diamine ( The dihydrazide compound / aromatic diamine) is preferably 30/70 to 95/5.

  Moreover, in the photosensitive resin composition of this invention, it is preferable to contain 5-60 weight part of (C) monofunctional or polyfunctional (meth) acrylate with respect to 100 weight part of (A) component.

  Moreover, this invention is a varnish-like photosensitive resin composition formed by melt | dissolving said photosensitive resin composition in a solvent. Furthermore, the present invention is a film-like photosensitive resin composition obtained by applying the above varnish-like photosensitive resin composition onto a substrate film and drying it. Furthermore, the present invention provides the above photosensitive resin composition as a film on a circuit wiring board having a patterned conductor layer, and then exposes, develops and cures to form a negative insulating film. This is a circuit wiring board.

  Since the cured product of the photosensitive resin composition of the present invention has high flexibility and flexibility, it is excellent in bending resistance and flexibility and can prevent warping of the substrate on which the cured product is laminated. Therefore, it can be preferably used as a solder resist, a plating resist or the like for manufacturing a flexible printed wiring board that requires flexible characteristics.

  Moreover, since the photosensitive composition of the present invention has high storage stability at room temperature and can be cured at a low temperature range of 200 ° C. or lower, the influence on the metal wiring can be reduced. Furthermore, the photosensitive composition of the present invention can be developed with a dilute alkaline aqueous solution after circuit processing using ultraviolet rays, and as a resist for manufacturing a flexible printed wiring board such as a solder resist material or a plating resist material. It is suitable for use.

  Hereinafter, the photosensitive resin composition of the present invention will be described, and then the film-shaped photosensitive resin composition and the circuit wiring board of the present invention using the same will be described. First, each component of the photosensitive resin composition of this invention is demonstrated.

  The photosensitive resin composition of this invention contains the said (A) component and (B) component. The component (A) is a polyamic acid resin having a radical polymerizable unsaturated bond, and the component (B) is a photopolymerization initiator.

The component (A) in the present invention includes, as raw materials, an acid anhydride component containing an aromatic tetracarboxylic acid anhydride, a diamine component containing a dihydrazide compound in a ratio of 30 to 100 mol with respect to 100 mol of all diamine components, and Is a polyamic acid resin obtained by reacting The component (A) is a hydrazide bond-containing polyamic acid resin having at least the structural unit represented by the above formula (1). In the present invention, the “hydrazide bond” means a divalent group “—CO—NH—NH—” derived from a hydrazide group (—CO—NH—NH ₂ ).

  The diamine component which is the raw material of the component (A) contains a dihydrazide compound in a proportion of 30 to 100 mol, preferably 50 to 95 mol, more preferably 60 to 90 mol, with respect to 100 mol of all diamine components. Good. When the dihydrazide compound is less than 30 moles with respect to 100 moles of all diamine components as raw materials, sufficient flexibility and heat resistance may not be obtained.

  Moreover, in order to express favorable bending resistance in the cured product of the photosensitive resin composition, the weight average molecular weight of the component (A) is preferably 20,000 to 300,000, and more preferably 40,000 to 200,000. When the weight average molecular weight of the component (A) is less than 20,000, sufficient flexibility may not be obtained, and when it exceeds 300,000, the solubility in a developer may be lowered.

The (A) component polyamic acid resin has a polymerizable polymerizable radical bond in its molecule, so that it can be cross-linked by the action of light or a photopolymerization initiator. In addition, the radically polymerizable unsaturated bond in the component (A) may be included in the structural unit represented by the formula (1) or may be included in a structural unit other than the formula (1). . The form in which the radically polymerizable unsaturated bond is contained in the structural unit represented by the formula (1) is a form in which a radically polymerizable unsaturated bond is present in R ₁ in the formula (1), or X ₁ And / or X ₂ is a monovalent organic group having a radical polymerizable unsaturated bond.

  (A) A diamine component having a radical polymerizable unsaturated bond used as a raw material when producing the polyamic acid resin of the component [radical polymerization other than dihydrazide compound and / or dihydrazide compound having radical polymerizable unsaturated bond] The diamine having an unsaturated bond] is preferably used in the range of 1 to 70 mol, more preferably in the range of 5 to 30 mol, per 100 mol of the total diamine component. By setting it as such a range, desired curing performance can be exhibited, without reducing radical polymerizability.

  In the above formula (1), Ar represents a tetravalent tetracarboxylic acid residue obtained by removing a carboxyl group from an aromatic tetracarboxylic acid. Since aromatic tetracarboxylic dianhydride is often used as the aromatic tetracarboxylic acid, some examples of Ar will be described by showing the aromatic tetracarboxylic dianhydride as a raw material. Examples of the aromatic tetracarboxylic dianhydride include pyromellitic dianhydride, 2,2 ′, 3,3′-, 2,3,3 ′, 4′- or 3,3 ′, 4,4 '-Benzophenonetetracarboxylic dianhydride, 2,3,6,7-, 1,2,4,5-, 1,4,5,8-, 1,2,6,7- or 1,2, 5,6-naphthalene-tetracarboxylic dianhydride, 4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride, 2,6- or 2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride, 2,3,6,7- (or 1,4,5,8-) tetrachloronaphthalene- 1,4,5,8- (or 2,3,6,7-) tetracarboxylic dianhydride, 3,3 ', 4,4'-, 2,2', 3,3'- or 2, 3,3 ', 4'-biphenyltetracarboxylic dianhydride, 3,3``, 4,4' '-, 2,3,3``, 4' '-or 2,2' ', 3, 3 ''-p-terphenyltetracarboxylic dianhydride, 2,2-bis (2,3- or 3,4-dicarboxyphenyl) -propane dianhydride, bis (2,3-dicarboxyphenyl) Ether dianhydride, bi (2,3- or 3.4-dicarboxyphenyl) methane dianhydride, bis (2,3- or 3,4-dicarboxyphenyl) sulfone dianhydride, 1,1-bis (2,3- or 3, 4-Dicarboxyphenyl) ethane dianhydride, 2,3,8,9-, 3,4,9,10-, 4,5,10,11- or 5,6,11,12-perylene-tetracarboxylic Acid dianhydride, 1,2,7,8-, 1,2,6,7- or 1,2,9,10-phenanthrene-tetracarboxylic dianhydride, pyrazine-2,3,5,6- Tetracarboxylic dianhydride, pyrrolidine-2,3,4,5-tetracarboxylic dianhydride, thiophene-2,3,4,5-tetracarboxylic dianhydride, 4,4'-oxydiphthalic dianhydride Things can be mentioned. Moreover, these can be used 1 type or in mixture of 2 or more types. Advantageously, pyromellitic anhydride, 4,4′-oxydiphthalic dianhydride, benzophenone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, biphenyl ether tetracarboxylic dianhydride and the like are exemplified. Among these, benzophenone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, and pyromellitic dianhydride are preferable. These aromatic tetracarboxylic dianhydrides may be used alone or in combination of two or more.

In the formula (1), R ₁ represents a single bond or a divalent residue obtained by removing a hydrazide group (—CONHNH ₂ ) from an aliphatic or aromatic dihydrazide, and R ₁ may be either linear or branched Further, it may have an unsaturated bond or a ring skeleton. In order to impart moderate flexibility and developability to the cured product, R ₁ is preferably an alkylene group having 2 to 12 carbon atoms or a phenylene group, and more preferably an alkylene group having 4 to 10 carbon atoms. By using a dihydrazide compound in which R ₁ has an alkylene group having 4 or more carbon atoms, the flexibility of the cured product of the photosensitive resin composition tends to increase. This tendency is considered to result from an increase in the number of bending sites in the molecular structure of the dihydrazide compound. Further, by the R ₁ uses a dihydrazide compound having an alkylene group having 10 or less carbon atoms, tend to heat resistance is high in the cured product. This tendency is due to the fact that in dihydrazide compounds with a small number of carbon atoms, the ratio of NH groups and CO groups is high with respect to the molecular weight of the compound. This is thought to be due to the increase in temperature. From such a viewpoint, in order to achieve both high flexibility and high heat resistance (that is, suppression of warpage), R ₁ is a linear alkylene group, and the average number of carbon atoms is preferably 4 to 10, It is desirable to use a dihydrazide compound that is more preferably 6-8. The dihydrazide compound to be used may be used singly or two or more dihydrazide compounds having different carbon numbers may be mixed and used.

In Formula (1), X ₁ and X ₂ independently represent a monovalent organic group having a hydroxyl group or a radical polymerizable unsaturated bond.

When at least one of X ₁ and X _{2 in} the structural unit represented by the formula (1) is a monovalent organic group having a radical polymerizable unsaturated bond, such a polyamic acid resin is present in the molecule. It can be obtained by reacting a compound having a structure having both a group capable of reacting with a carboxyl group and a radical polymerizable unsaturated bond with an aromatic tetracarboxylic acid (anhydride). The compound having a structure capable of reacting with a carboxyl group and a radical polymerizable unsaturated bond in the molecule includes at least one group selected from a hydroxyl group, a mercapto group, an amino group, an epoxy group, an isocyanate group, and the like. Examples thereof include (meth) acrylic acid ester compounds, vinyl compounds, and allyl compounds.

R ₁ in the formula (1) means a single bond or a divalent residue obtained by removing a hydrazide group (—CONHNH ₂ ) from an aliphatic or aromatic dihydrazide. That is, the dihydrazide compound which forms a part of the raw material diamine component can be represented by the following general formula (2).
_{H 2 NHNOC-R 1 -CONHNH 2} ... (2)

As described above, R ₁ is any _one of a single bond, an aliphatic group, and an aromatic group. Preferred examples of R ₁ are illustrated by the following examples of dihydrazide compounds. For example, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, suberic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide dihydrazide, maleic acid dihydrazide Diglycolic acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, phthalic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 4,4-bisbenzenedihydrazide, 1,4-naphthoic acid dihydrazide, 2 , 6-pyridinedihydrazide, itaconic acid dihydrazide and the like. These dihydrazide compounds may be used alone or in combination of two or more.

As the polyamic acid resin of component (A), a part of the amic acid bond may be imidized. However, in order to ensure good alkali developability, the imidation ratio is less than 50%, preferably less than 30%. The imidation ratio of the polyamic acid is determined, for example, by measuring the infrared absorption spectrum of the polyimide thin film by a transmission method using a Fourier transform infrared spectrophotometer “FT / IR620 (trade name)” manufactured by JASCO Corporation. , relative to the benzene ring carbon hydrogen bonds of 1,000 cm ^-1, is calculated from the absorbance from the imide groups of 1,720 cm ^-1.

(A) The preferable form of a component can illustrate the polyamic acid resin obtained by making the acid anhydride component containing following A1 react, and the diamine component containing following A2 and A3.
A1: aromatic tetracarboxylic dianhydride A2: dihydrazide compound A3: aromatic diamine having a radical polymerizable unsaturated bond other than dihydrazide compound

  In the above case, the molar ratio (A2 / A3) of the dihydrazide compound of A2 to the aromatic diamine having a radical polymerizable unsaturated bond of A3 in the raw material diamine component is 30/70 to 95/5. preferable. That is, in the raw material, the amount of the A2 dihydrazide compound is preferably in the range of 30 to 95 mol, more preferably in the range of 50 to 95 mol, and in the range of 60 to 90 mol with respect to 100 mol of the total diamine component. The inside is more preferable. In the raw material, the amount of the aromatic diamine having an A3 radical polymerizable unsaturated bond is preferably within the range of 5 to 70 mol, within the range of 5 to 50 mol, relative to 100 mol of the total diamine component. Is more preferable, and within the range of 10 to 30 mol is more preferable. By setting the amount of the diamine component in the raw material within the above range, shrinkage of the cured product can be suppressed and sufficient heat resistance can be imparted to the cured product.

  The aromatic diamine having an A3 radical polymerizable unsaturated bond is an aromatic diamine that does not contain a dihydrazide compound, and preferably an aromatic diamine represented by the following general formula (3).

（式中、Ｒ_２は単結合又は２価の有機基を示し、Ｒ_３、Ｒ_４はラジカル重合性の不飽和結合を有する１価の有機基を示す。）

(In the formula, R ₂ represents a single bond or a divalent organic group, and R ₃ and R ₄ represent a monovalent organic group having a radical polymerizable unsaturated bond.)

In Formula (3), R ₂ represents a single bond or a divalent group, and is preferably any one selected from a single bond, CH ₂ , C (CH ₃ ) ₂ and SO ₂ . R ₃ and R _{4 each} represent a monovalent organic group having a radically polymerizable unsaturated bond, but a monovalent organic group having a (meth) acryl group, a vinyl group or an allyl group at the terminal or side chain. A group represented by CH═CH—R ₅ — is more preferable. Here, R ₅ represents a direct bond, an alkylene group having 1 to 6 carbon atoms or a phenylene group, and R ₅ is a direct bond (that is, R ₃ and R _{4 in} formula (3) are vinyl groups). Is preferable in terms of reactivity. Specific examples of such a compound of formula (3) include 2,2′-divinyl-4,4′-diamino-biphenyl.

  In addition, as a diamine component used for constituting the polyamic acid resin of component (A), an aromatic diamine other than A2 (dihydrazide compound) and A3 (aromatic diamine having a radical polymerizable unsaturated bond) (A4) can be further used in combination. Specific examples of the aromatic diamine of A4 include p-phenylenediamine, m-phenylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminophenylethane, 4,4′-diaminophenyl ether, 4,4 '-Didiaminophenyl sulfide, 4,4'-didiaminophenyl sulfone, 1,5-diaminonaphthalene, 3,3-dimethyl-4,4'-diaminobiphenyl, 5-amino-1- (4'-aminophenyl) ) -1,3,3-trimethylindane, 4,4'-diaminobenzanilide, 3,5-diamino-4'-trifluoromethylbenzanilide, 3,4'-diaminodiphenyl ether, 2,7-diaminofluorene, 2,2-bis (4-aminophenyl) hexafluoropropane, 4,4'-methylene-bis (2-chloroaniline), 2,2 ', 5,5'-tetrachloro-4,4'-diaminobiphenyl 2,2'-dichloro-4,4'-diamino-dimethoxy Phenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 4,4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 2,2-bis [4- (4-aminophenoxy) ) Phenyl] propane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) Biphenyl, 1,3'-bis (4-aminophenoxy) benzene, 9,9-bis (4-aminophenyl) fluorene, 4,4 '-(p-phenyleneisopropylidene) bisaniline, 4,4'-(m -Phenylene isopropylidene) bisaniline, 2,2'-bis [4- (4-amino-2-trifluoromethyl) phenoxy] -octafluorobiphenyl, hydroxyaminobiphenyl, and the like. The amount of the aromatic diamine used is preferably in the range of 0 to 50 mol, more preferably in the range of 5 to 20 mol, with respect to 100 mol of the total diamine component. When this ratio exceeds 50 moles, the content of the A2 (dihydrazide compound) and the A3 (aromatic diamine having a radical polymerizable unsaturated bond) is decreased, and photocurability, heat resistance, and low temperature curing. May be impaired.

  An example of a method for producing the (A) polyamic acid resin used in the present invention will be described. First, a diamine other than a dihydrazide compound and a dihydrazide compound is dispersed in a solvent. While this is being stirred, the acid anhydride is gradually added under a nitrogen atmosphere. Then, the polyamic acid resin as component (A) is obtained by reacting with stirring for 2 to 8 hours. The (A) component polyamic acid resin obtained by such a method is a mixture having different degrees of polymerization. In addition, it is good also as a random polymerization type or block polymerization type polyamic acid resin by changing the addition order and addition method of diamine and an acid anhydride.

  Examples of the solvent for performing the above reaction include organic solvents such as triethylene glycol dimethyl ether (triglyme), diethylene glycol dimethyl ether (diglyme), dimethylacetamide, N-methylpyrrolidone, methyl ethyl ketone, methyl isobutyl ketone, xylene, and toluene, or a mixed solvent thereof. Can be used.

  The acid anhydride component and the diamine component (a dihydrazide compound or a diamine other than a dihydrazide compound) are desirably added in approximately equimolar amounts. The reaction can be carried out without proceeding imidization by carrying out the reaction at room temperature or lower, preferably around 0 ° C. By changing the mixing ratio of the diamine component containing the dihydrazide compound and the acid anhydride, the degree of polymerization and the acid value can be changed.

  The (A) component polyamic acid resin thus obtained is mixed with a photopolymerization initiator (B) described later to obtain a photosensitive resin composition. This polyamic acid resin of component (A) can be used for applications requiring flexibility because it has flexibility even after curing, and can be suitably used as a resin component of a photosensitive resin composition. Moreover, since the polyamic acid resin of component (A) has a carboxy group at the terminal or side chain, it is also suitable for development with an alkaline aqueous solution.

  Examples of the photopolymerization initiator of the component (B) include acetophenone, 2,2-dimethoxyacetophenone, p-dimethylaminoacetophenone, Michler's ketone, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n- Propyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzyl dimethyl ketal, thioxazone, 2-chlorothioxazone, 2-methylthioxazone, 2-hydroxy-2-methyl-1-phenyl-1-one, 1- ( Various photopolymerization initiators such as 4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, methylbenzoyl formate, 1-hydroxycyclohexyl phenyl ketone can be used. That. The amount of the photopolymerization initiator used is preferably 0.5 to 20 parts by weight and more preferably 1 to 10 parts by weight with respect to 100 parts by weight of the (A) component polyamic acid resin.

  The photosensitive resin composition of the present invention contains (A) component polyamic acid resin and (B) component photopolymerization initiator as essential components, and is composed of other resins and monomers such as acrylate as described later. A resin component (here, “resin component” includes a monomer), a sensitizer, a solvent, and the like can be added as necessary. By setting it as such a composition, not only will it have the characteristic which was more excellent as a photosensitive resin composition, but the use will also be expanded. In addition, in the photosensitive resin composition of the present invention, when a varnish is formed by adding a solvent, it may be referred to as a `` varnish-like photosensitive resin composition '', but when it is not necessary to distinguish in particular, This is represented by the expression “photosensitive resin composition”. Moreover, in the photosensitive resin composition of this invention, the description about the compounding quantity or compounding ratio of each component (except a solvent) shall mean the state which does not contain a solvent unless it notes.

  As mentioned above, (C) monofunctional or polyfunctional (meth) acrylate can be mix | blended with the photosensitive resin composition of this invention as an arbitrary component. Component (C) is blended for the purpose of promoting cross-linking in the photopolymerization reaction. Examples of acrylates that can be used for the purpose include 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxy Propyl acrylate, 2-hydroxyethyl acryloyl phosphate, 2-methoxyethoxyethyl acrylate, 2-ethoxyethoxyethyl acrylate, tetrahydrofurfryl acrylate, phenoxyethyl acrylate, isodecyl acrylate, stearyl acrylate, lauryl acrylate, glycidyl acrylate, allyl acrylate, Ethoxy acrylate, methoxy acrylate, N, N′-dimethylaminoethyl acrylate, benzyl acrylate, 2-hydroxyethyl Monoacrylate such as acryloyl phosphate, dicyclopentadienyl acrylate, dicyclopentadiene ethoxy acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, 1,3-butanediol diacrylate, 1,4-butanediol diacrylate 1,6-butanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, polyethylene glycol 200 diacrylate, polyethylene glycol 400 diacrylate, polyethylene glycol 600 diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, hydroxypivalin Acid ester neopentyl glycol diacrylate, trie Lenglycol diacrylate, bis (acryloxyethoxy) bisphenol A, bis (acryloxyethoxy) tetrabromobisphenol A, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanate Polyfunctional acrylates such as pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, and dipentaerythritol monohydroxypentaacrylate can be used. In order to have good photosensitivity and avoid solubility in a developer and phase separation with a resin, among the above exemplified monomer compounds, it is bifunctional or more, and polar groups such as hydroxyl groups and carbonyl groups are included in the skeleton. Preferred are monomer compounds. Examples of such monomer compounds include tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, dipentaerythritol. Mention may be made of monohydroxypentaacrylate.

  In the photosensitive resin composition of the present invention, the blending amount of the (meth) acrylate of the component (C) is preferably in the range of 5 to 60 parts by weight with respect to 100 parts by weight of the polyamic acid resin of the component (A). A range of 10 to 40 parts by weight is more preferable.

  Further, as described above, it is also advantageous to add a sensitizer to the photosensitive resin composition of the present invention. In this case, compounds having various sensitizing actions such as benzophenone are used as the sensitizer. it can. The sensitizer is preferably added in an amount of 0.01 to 2 parts by weight, more preferably 0.05 to 0.5 parts by weight, relative to 100 parts by weight of the polyamic acid resin (A).

  The viscosity of the photosensitive resin composition of the present invention can be adjusted with various organic solvents and the like. Examples of preferable organic solvents for use include triethylene glycol dimethyl ether (triglyme), diethylene glycol dimethyl ether (diglyme), dimethylacetamide, N-methylpyrrolidone, propylene glycol monomethyl ether acetate (pegmia), ethyl lactate, methyl ethyl ketone, methyl isobutyl ketone, xylene. , Toluene or a mixed solvent thereof. The amount of the solvent used is preferably in the range of 10 to 200 parts by weight with respect to 100 parts by weight of the solid content of the photosensitive resin composition. A photosensitive resin composition that contains 10% by weight or more of a solvent and is liquid at room temperature is referred to as a “varnish-like photosensitive resin composition”. Moreover, when the organic solvent used as a reaction solvent at the time of polyamic acid resin manufacture remains, the amount of solvents including this solvent is calculated.

  Furthermore, the component which reacts with carboxy groups, such as an epoxy, can also be added to the photosensitive resin composition of this invention. The added amount of such components should be less than 30 parts by weight, preferably less than 10 parts by weight with respect to 100 parts by weight of the solid content of the photosensitive resin composition so as not to impair the solubility in the developer. .

  In addition, when the photosensitive resin composition is used for solder resist applications, known pigments such as phthalocyanine green and phthalocyanine blue can be added as necessary so long as the characteristics as the solder resist are not impaired. . The preferable addition amount of the pigment in that case exists in the range of 1 to 20 weight% with respect to the photosensitive resin composition (solid content). Furthermore, a known filler can be added to the photosensitive resin composition of the present invention as necessary, and it can be applied to use as a photosensitive paint.

  The preferable composition of the solid content (including the monomer and excluding the solvent) of the photosensitive resin composition of the present invention is, for example, (A) component polyamic acid resin: 50 to 100% by weight, preferably 60 to 90% by weight, Component (B) photopolymerization initiator: 1 to 20% by weight, preferably 1 to 10% by weight, sensitizer: 0 to 2% by weight, preferably 0.05 to 0.5% by weight, other resins, Resin component comprising monomer such as acrylate: 0 to 45% by weight, preferably 10 to 30% by weight.

  In the photosensitive resin composition of the present invention, flexibility and various characteristics can be expressed by blending the above-mentioned various additives and solvents into the resin component, preferably in the above ratio, and mixing them uniformly. The photosensitive resin composition of the present invention is, for example, a viscous liquid, varnish-like, or ink-like form, or a film-like or sheet-like form obtained by applying and drying these on a base film. be able to.

[Application to circuit wiring board]
The photosensitive resin composition of the present invention can be used according to a known method, but when applied to a circuit wiring board, the thickness of the circuit wiring board is 5 to 100 μm using a screen printer or a coater, Preferably, direct coating can be performed with a thickness of 10 to 40 μm. The coated composition is preliminarily dried at a temperature of 50 to 120 ° C., then selectively exposed using a photomask having a predetermined mask pattern, and developed with an alkaline aqueous solution. It is possible to remove the exposed portion and cure the remaining exposed portion by, for example, a heat treatment at a temperature of 120 to 200 ° C. for 20 to 120 minutes to form a patterned negative insulating film. The wavelength of light when photopolymerizing the photosensitive resin composition of the present invention is, for example, in the range of 250 to 450 nm, and it is particularly preferable to use light having a wavelength in the range of 290 to 405 nm.

  Here, as the alkaline aqueous solution capable of developing the photosensitive resin composition of the present invention, for example, an aqueous sodium carbonate solution can be used. The concentration of the alkaline aqueous solution can be set to 1 to 5% by weight, for example. Thus, since the photosensitive resin composition of the present invention can be developed with a dilute alkaline aqueous solution, it is advantageous in terms of versatility and reduction of environmental burden.

  Moreover, the photosensitive resin composition of this invention can also form the film form previously, and can also employ | adopt the method of laminating it on a circuit wiring board. The circuit wiring board obtained by laminating can be patterned by performing exposure, development and thermosetting similar to those described above to form a negative insulating coating.

  Thus, the laminate having the circuit wiring board and the photosensitive resin layer obtained by applying or laminating the photosensitive resin composition of the present invention to the circuit wiring board is a cured product of the photosensitive resin composition of the present invention. Since (insulating coating) is excellent in flexibility, it can be preferably used, for example, as a solder resist or a plating resist, particularly for processing of a flexible wiring board. In addition, since the circuit wiring board using the photosensitive resin composition of the present invention has a good balance of properties such as flex resistance, heat resistance and plating resistance of the cured product of the photosensitive resin composition, these characteristics Suitable for various applications that require

[Film-like photosensitive resin composition]
The photosensitive resin composition of the present invention is applied to a substrate such as a PET film or the like that has been subjected to a release treatment in advance with a solution of the photosensitive resin composition having a thickness of, for example, 5 to 100 μm, preferably 10 to 50 μm. The film-like photosensitive resin composition can be obtained by carrying out temporary drying at 50 to 210 ° C, preferably 80 to 140 ° C. In addition, when applying a film-form photosensitive resin composition to a circuit wiring board, the method of thermocompression bonding to a wiring board using a laminator is common, and the lamination temperature in that case is a temperature range of 20-100 degreeC. Is preferred.

  Since the photosensitive resin composition of the present invention has a radically polymerizable unsaturated bond such as a double bond, a carboxylic acid and a derivative group thereof, it is polymerized by light or heat to form a cured product having a three-dimensional structure. It has the property to do. Since this cured product contains abundant alkyl chains and amide bond sites mainly derived from dihydrazide compounds, flexibility is maintained. From these facts, the cured product obtained by curing the photosensitive resin composition of the present invention has superior heat resistance and resistance compared to a cured product obtained by curing an ordinary photosensitive resin alone or in combination. Flexibility and flexibility are imparted.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited at all by these Examples. Unless otherwise specified in the examples of the present invention, various measurements and evaluations are as follows.

[Method for evaluating photocurability]
Photo-curability is evaluated by casting the photosensitive resin composition onto a substrate so that the film thickness after drying is 25 μm, and using an exposure mask (manufactured by Hitec Corporation, high-pressure mercury lamp) using an evaluation mask. And exposed to light having a wavelength of 365 nm. Development was performed at 30 ° C. for 40 to 200 seconds using a 1 wt% sodium carbonate aqueous solution and washed with high-pressure rinsing. When the exposure amount was 500 mJ or less and a via hole having a diameter of 500 μm could be resolved without reducing the film, “OK” (good) was obtained, and “NG” (defective) was obtained when the via hole could not be resolved.

[Method for evaluating solubility of alkali developer]
The alkali developer solubility was evaluated by the following method. The photosensitive resin composition was cast on a substrate so that the film thickness after drying was 25 μm, treated at 30 ° C. with a 1% aqueous sodium carbonate solution, washed with a high-pressure rinse, and photosensitive resin The case where the layer was completely dissolved within 300 seconds was designated as “OK” (good), and the case where the layer was not obtained was designated as “NG” (defective).

[Evaluation method of warpage]
A sample for warpage evaluation is obtained by applying a photosensitive resin composition to a polyimide film having a thickness of 5 × 5 cm and a thickness of 25 μm so that the film thickness after exposure and curing is 25 μm, drying, exposing and curing. 250 ° C./60 s and 260 ° C./10 s reflow treatment was performed. For the evaluation of the warpage, the evaluation sample was placed on a flat base so that the warping direction was concave, the distance between each vertex and the base was measured, and the average value of four points was taken as the amount of warpage. The warpage amount of less than 5 mm was defined as “OK” (good), and the warpage amount was defined as “NG” (defective).

[Evaluation method of heat resistance]
Evaluation of heat resistance was performed using a film sample after exposure and curing of a width of 3 mm, a length of 20 mm, and a thickness of 25 μm, using a thermomechanical analyzer (manufactured by BRUKER, 4000SA) at a distance between chucks of 15 mm. The amount of thermal expansion of the sample length fragrance was measured under the conditions of a load of 2 g and a heating rate of 10 ° C./min, the inflection point was defined as the glass transition temperature (Tg), and the glass transition temperature value was defined as the heat resistant temperature. .

[Bend resistance evaluation method]
Bending resistance is evaluated by laminating, exposing, and curing a film-like sample on a copper-clad laminate that has been processed into a conductor width of 0.13 mm to 0.91 mm and a space between conductors of 0.18 mm to 0.20 mm. A sample for evaluation was prepared, and a cured product of the photosensitive resin composition was mounted inward under the conditions of a curvature radius: 1.25 mm, a slide speed: 1500 cycles / minute, and a slide length: 20 mm, An IPC bending test was performed, and evaluation was performed based on the number of bendings until the circuit was disconnected.

Synthesis example 1
In a reactor equipped with a nitrogen injection tube, 87.5 g (0.34 mol) of an aliphatic dihydrazide in which R ₁ in the formula (2) is — (CH ₂ ) ₁₀ — and R ₂ in the formula (3) Is a single bond, 20.0 g (0.08 mol) of a diamine (2,2′-divinyl-4,4′-diamino-biphenyl) in which an amino group is located in the para position and a vinyl group is located in the meta position In addition, it was dispersed in 731 g of N, N-dimethylacetamide (DMAc). To this was added 136.4 g (0.42 mol) of benzophenonetetracarboxylic dianhydride (BTDA) and stirred for 5 hours at room temperature in a nitrogen atmosphere to obtain a varnish of polyamic acid resin 1 as component (A). It was. From the measurement result of GPC (polystyrene standard product conversion), the polyamic acid resin 1 obtained had a weight average molecular weight of 5.4 × 10 ⁴ and a molecular weight distribution of 1.64. Further, the viscosity at 25 ° C. of the DMAc solution (resin concentration: 25% by weight) of the polyamic acid resin 1 was measured using an E-type viscometer and found to be 1574 cPa · s.

Synthesis example 2
In a reactor equipped with a nitrogen injection tube, 58.97 g (0.34 mol) of an aliphatic dihydrazide in which R ₁ in formula (2) is — (CH ₂ ) ₄ — was obtained and 2,2′-divinyl-4 2,4'-diamino-biphenyl was added in an amount of 20.0 g (0.08 mol) and dispersed in 646 g of DMAc. 136.4 g (0.42 mol) of BTDA was added to this, and the varnish of the polyamic acid resin 2 used as (A) component was obtained by stirring under room temperature and nitrogen atmosphere for 5 hours. The obtained polyamic acid resin 2 had a weight average molecular weight of 6.8 × 10 ⁴ . Further, the viscosity at 25 ° C. of the DMAc solution of the polyamic acid resin 2 (resin concentration: 25% by weight) was measured by using an E-type viscometer, and was 7782 Pa · s.

Synthesis example 3
In a reactor equipped with a nitrogen injection tube, 58.97 g (0.34 mol) of an aliphatic dihydrazide in which R ₁ in formula (2) is — (CH ₂ ) ₄ — was obtained and 2,2′-divinyl-4 20.0 g (0.08 mol) of 4,4′-diamino-biphenyl was added and dispersed in 514 g of DMAc. To this was added 92.3 g (0.42 mol) of pyromellitic dianhydride (PMDA), and the mixture was stirred at room temperature in a nitrogen atmosphere for 5 hours to obtain a varnish of polyamic acid resin 3 as component (A). . The obtained polyamic acid resin 3 had a weight average molecular weight of 5.8 × 10 ⁴ . Further, the viscosity at 25 ° C. of the DMAc solution (resin concentration: 25% by weight) of the polyamic acid resin 3 was measured using an E-type viscometer and found to be 2580 Pa · s.

Synthesis example 4
In a reactor equipped with a nitrogen injection tube, 44.23 g (0.25 mol) of an aliphatic dihydrazide in which R ₁ in the formula (2) is — (CH ₂ ) ₄ — 40.0 g (0.17 mol) of 2′-divinyl-4,4′-diamino-biphenyl was added and dispersed in 662 g of DMAc. 136.4 g (0.42 mol) of BTDA was added to this, and the varnish of the polyamic acid resin 4 used as (A) component was obtained by stirring under room temperature and nitrogen atmosphere for 5 hours. From the measurement result of GPC (polystyrene standard product conversion), the weight average molecular weight of the obtained polyamic acid resin 4 was 5.6 × 10 ⁴ . Further, the viscosity at 25 ° C. of the DMAc solution of the polyamic acid resin 4 (resin concentration: 25% by weight) was measured using an E-type viscometer and found to be 2278 Pa · s.

Synthesis example 5
In a reactor equipped with a nitrogen injection tube, 48.9 g (0.19 mol) of an aliphatic dihydrazide in which R _{1 of} formula (2) is — (CH ₂ ) ₁₀ — and R _{1 of} formula (2) is — ( 32.96 g (0.19 mol) of aliphatic dihydrazide of CH ₂ ) ₄ -and 10.0 g (0.04 mol) of 2,2'-divinyl-4,4'-diamino-biphenyl were added and dispersed in 646 g of DMAc. I let you. 136.4 g (0.42 mol) of BTDA was added to this, and the varnish of the polyamic acid resin 5 used as (A) component was obtained by stirring at room temperature under nitrogen atmosphere for 5 hours. The resulting polyamic acid resin 5 had a weight average molecular weight of 6.1 × 10 ⁴ . Further, the viscosity at 25 ° C. of the DMAc solution of the polyamic acid resin 5 (resin concentration: 25% by weight) was measured using an E-type viscometer to be 3453 Pa · s.

Synthesis Example 6
In a reactor equipped with a nitrogen inlet tube, 8.01 g (0.04 mol) of 4,4′-diaminodiphenyl ether and 10.0 g (0.04 mol) of 2,2′-divinyl-4,4′-diamino-biphenyl. 04 mol) and 95.21 g (0.13 mol) of polydimethylsiloxanediamine (Toray Dow Corning Silicone: BY16-853X) having a number average molecular weight of about 750 were added and dispersed in 553 g of DMAc. To this, 68.18 g (0.21 mol) of BTDA was added and stirred for 5 hours at room temperature in a nitrogen atmosphere to obtain a varnish of polyamic acid resin 6.

Synthesis example 7
In a reactor equipped with a nitrogen injection tube, 126.95 g (0.17 mol) of polydimethylsiloxanediamine having a number average molecular weight of about 750 (manufactured by Toray Dow Corning Silicone: BY16-853X), 2,2 ′ -10.0 g (0.04 mol) of divinyl-4,4′-diamino-biphenyl was added and dispersed in 615 g of DMAc. To this was added 68.18 g (0.21 mol) of BTDA, and the mixture was stirred at room temperature in a nitrogen atmosphere for 5 hours to obtain a varnish of polyamic acid resin 7.

Example 1
30 parts by weight of pentaerythritol triacrylate (manufactured by Nippon Kayaku Co., Ltd .: PET-30) with respect to the varnish of the polyamic acid resin 1 obtained in Synthesis Example 1 (100 parts by weight as the polyamic acid resin, hereinafter the same). 3 parts by weight of a photopolymerization initiator (Ciba Specialty Chemicals Inc .: OXE-02) was blended to obtain a varnish-like photosensitive resin composition. This was coated on a PET film that had been previously subjected to a release treatment so that the film thickness after drying was 25 μm, and dried at 110 ° C. for 10 minutes to obtain a film-like photosensitive resin composition. Table 1 shows the blending ratio and characteristics of the photosensitive resin composition.

  After preparing said varnish-like photosensitive resin composition, it stored in a 23 degreeC thermostat. Three days after storage, a film-like photosensitive resin composition was prepared in the same manner as described above, but no problem occurred. Further, no problem occurred with respect to the characteristics of the photosensitive resin composition.

Example 2
In Example 1, 30 parts by weight of trimethylolpropane triacrylate (manufactured by Nippon Kayaku Co., Ltd .: TMPTA) was blended instead of 30 parts by weight of pentaerythritol triacrylate (Nippon Kayaku Co., Ltd .: PET-30). A film-like photosensitive resin composition was obtained in the same manner as in Example 1 except that. Table 1 shows the blending ratio and characteristics of the photosensitive resin composition.

Example 3
In Example 1, in place of the varnish of the polyamic acid resin 1, the varnish of the polyamic acid resin 2 obtained in Synthesis Example 2 was used in the same manner as in Example 1, did. Table 1 shows the blending ratio and characteristics of the photosensitive resin composition.

Example 4
In Example 1, in place of the varnish of the polyamic acid resin 1, the varnish of the polyamic acid resin 3 obtained in Synthesis Example 3 was used in the same manner as in Example 1, did. Table 1 shows the blending ratio and characteristics of the photosensitive resin composition.

Example 5
In Example 1, in place of the varnish of the polyamic acid resin 1, the varnish of the polyamic acid resin 4 obtained in Synthesis Example 4 was used in the same manner as in Example 1, and the film-like photosensitive resin composition and did. Table 1 shows the blending ratio and characteristics of the photosensitive resin composition.

Example 6
In Example 1, in place of the varnish of the polyamic acid resin 1, the varnish of the polyamic acid resin 5 obtained in Synthesis Example 5 was used in the same manner as in Example 1, and the film-like photosensitive resin composition and did. Table 1 shows the blending ratio and characteristics of the photosensitive resin composition.

Comparative Example 1
In Example 1, instead of the varnish of the polyamic acid resin 1, the varnish of the polyamic acid resin 6 obtained in Synthesis Example 6 was used in the same manner as in Example 1, and the film-like photosensitive resin composition and did. Table 1 shows the blending ratio and characteristics of the photosensitive resin composition.

Comparative Example 2
In Example 1, in place of the varnish of the polyamic acid resin 1, the varnish of the polyamic acid resin 7 obtained in Synthesis Example 7 was used in the same manner as in Example 1, and the film-like photosensitive resin composition and did. Table 1 shows the blending ratio and characteristics of the photosensitive resin composition.

  The above results are summarized in Table 1. In the table, “parts” means parts by weight.

  As shown in Table 1, in Examples 1 to 6, obtained by reacting a diamine component containing a dihydrazide compound in a ratio of 30 to 100 mol with a tetracarboxylic acid anhydride with respect to 100 mol of all diamine components as raw materials. Since the photosensitive resin composition containing the polyhydric acid resin containing a hydrazide bond having the structural unit represented by the formula (1) is used, the cured product has less warpage and is excellent in heat resistance and bending resistance. It was. On the other hand, a photosensitive resin composition containing a siloxane-based diamine as a raw material diamine component of the photosensitive resin composition but containing no hydrazide bond-containing polyamic acid resin having a structural unit represented by the formula (1) is used. In Comparative Examples 1 and 2, the warpage was large, and the heat resistance and bending resistance were remarkably inferior.

Claims (6)

(A) a polyamic acid resin having a radical polymerizable unsaturated bond, and (B) a photosensitive resin composition containing a photopolymerization initiator,
(A) A component makes the raw material react the acid anhydride component containing an aromatic tetracarboxylic anhydride, and the diamine component which contains a dihydrazide compound in the ratio of 30-100 mol with respect to 100 mol of all the diamine components. A hydrazide bond-containing polyamic acid resin having a structural unit represented by the following general formula (1),
(A) The photosensitive resin composition characterized by containing 0.5-20 weight part of (B) component with respect to 100 weight part of components.

(In the formula, Ar represents a tetravalent tetracarboxylic acid residue obtained by removing a carboxyl group from an aromatic tetracarboxylic acid, and R ₁ represents a single bond or _{2 obtained} by removing a hydrazide group —CONHNH ₂ from an aliphatic or aromatic dihydrazide. X ₁ and X ₂ independently represent a hydroxyl group or a monovalent organic group having a radical polymerizable unsaturated bond.   The diamine component of the raw material contains a dihydrazide compound and an aromatic diamine having a radical polymerizable unsaturated bond, and the molar ratio of the dihydrazide compound to the aromatic diamine (dihydrazide compound / aromatic diamine) is 30 / It is 70-95 / 5, The photosensitive resin composition of Claim 1 characterized by the above-mentioned.   The photosensitive resin according to claim 1 or 2, further comprising 5 to 60 parts by weight of (C) a monofunctional or polyfunctional (meth) acrylate with respect to 100 parts by weight of the component (A). Composition.   A varnish-like photosensitive resin composition obtained by dissolving the photosensitive resin composition according to claim 1 in a solvent.   The film-like photosensitive resin composition formed by apply | coating and drying the varnish-like photosensitive resin composition of Claim 4 on a board | substrate film.   The photosensitive resin composition according to claim 1 is formed as a film on a circuit wiring board having a patterned conductor layer, and then exposed, developed, and cured to form a negative insulating film. A circuit wiring board.