KR20180063171A - Curable resin composition, dry film and printed circuit board using the same - Google Patents

Abstract

The present invention relates to a curable resin composition capable of obtaining a cured product highly compatible with insulation reliability such as ion migration resistance and flame retardancy, a dry film having a resin layer obtained from the composition, a cured product of the composition or the dry film, A printed wiring board having a cured product is provided. A curable resin composition containing a carboxyl group-containing resin, a thermosetting component, a flame retardant and an ion scavenger, wherein the ion scavenger is a mixture of hydrotalcite ion scavenger and hydrotalcite scavenger Curable resin composition.

Description

Curable resin composition, dry film and printed circuit board using the same

The present invention relates to a curable resin composition, a dry film and a printed wiring board using the same.

The curable resin composition is widely used as a solder resist for a printed wiring board such as a flexible printed wiring board (hereinafter abbreviated as FPC). This solder resist is used for the purpose of protecting the surface layer circuit of the printed wiring board, and insulation reliability is required. Particularly in recent years, the density of the printed wiring board is remarkably high, and its circuit is minimum, and it is 10 μm / 10 μm in L (line) / S (space). Among them, in the FPC application, in order to attach an electromagnetic wave shield on an insulating film such as a coverlay, in addition to the ion migration resistance between circuits (in the XY-axis direction) Ion migration tolerance is also required, and higher insulation reliability, particularly ion migration resistance, is required.

Conventionally, as a means for improving insulation reliability, particularly ion migration resistance, of a printed wiring board, a technique of compounding a layered multiple oxide such as hydrotalcite in a photosensitive resin composition has been proposed (Patent Document 1).

On the other hand, the solder resist is required to have flame retardancy because the printed wiring board is mounted on electronic equipment. Among them, the FPC solder resist is different from a rigid-type solder resist for a printed wiring board formed on a glass epoxy substrate and is usually formed on a polyimide substrate, so that higher flame retardancy is required.

Japanese Patent Application Laid-Open No. 2010-237270

As described above, in particular, the curable resin composition used for the solder resist in the FPC application is required to have excellent flame retardancy in addition to insulation reliability such as ion migration resistance.

Therefore, an object of the present invention is to provide a curable resin composition capable of obtaining a cured product highly compatible with insulation reliability such as ion migration resistance and flame retardancy, a dry film having a resin layer obtained from the composition, And a printed wiring board having the cured product.

DISCLOSURE OF THE INVENTION The present inventors have intensively studied in order to solve the above problems and found that mixing an ion trapping agent of hydrotalcite system to improve insulation reliability, particularly ion migration resistance, It has been found that the blend improves insulation reliability such as ion migration resistance, but rather lowers the flame retardancy. Therefore, as a result of further studies, it has been found that by using a mixture of hydrotalcite-based ion scavenger and an ion scavenger other than hydrotalcite-based, the insulation reliability such as ion migration resistance can be improved without lowering the flame retardancy And the present invention has been accomplished.

That is, the curable resin composition of the present invention is a curable resin composition containing a carboxyl group-containing resin, a thermosetting component, a flame retardant and an ion scavenger, wherein the ion scavenger is a hydrotalcite- And an ion trapping agent.

In the curable resin composition of the present invention, the mixing ratio of the hydrotalcite-based ion scavenger to the ion scavenger other than the hydrotalcite-based scavenger is preferably in the range of 100: 10 to 100: 500 on the mass basis to be. The curable resin composition of the present invention preferably contains at least one of a photopolymerization initiator and a compound having an ethylenic unsaturated group. Further, the curable resin composition of the present invention is preferably a photosensitive resin composition containing a photopolymerization initiator. The thermosetting component is preferably a cyclic (thio) ether compound. The curable resin composition of the present invention can be suitably used for forming at least one of a coverlay and a solder resist.

Further, the dry film of the present invention is characterized by having a resin layer formed by applying and drying the curable resin composition on a film.

The cured product of the present invention is characterized by curing the curable resin composition or the resin layer of the dry film.

Further, the printed wiring board of the present invention is characterized by comprising the cured product.

According to the present invention, there is provided a curable resin composition capable of obtaining a cured product highly compatible with insulation reliability such as ion migration resistance and flame retardancy, a dry film having a resin layer obtained from the composition, and a resin layer of the composition or the dry film And a printed wiring board having the cured product.

The curable resin composition of the present invention can be suitably used for forming at least one of the coverlay of the FPC and the solder resist. The curable resin composition of the present invention is also suitable as a resin composition for an adhesive layer of a coverlay of a multilayer structure. Here, the adhesive layer refers to a resin layer in contact with the FPC of a coverlay having a laminate structure of two or more layers.

Fig. 1 is a process diagram schematically showing an example of a method for producing a printed wiring board suitable for the present invention.
2 is a process diagram schematically showing another example of a method for producing a printed wiring board suitable for the present invention.

The curable resin composition of the present invention (hereinafter, simply referred to as " resin composition ") includes a carboxyl group-containing resin, a thermosetting component, a flame retardant and an ion capturing agent. Particularly in the present invention, it is essential that the ion trapping agent is a mixture of a hydrotalcite-based ion trapping agent and an ion trapping agent other than hydrotalcite-based. By using these ion trapping agents, insulation such as ion migration resistance The reliability and the flame retardancy can be highly compatible with each other.

Hereinafter, each component will be described in detail.

[Resin containing a carboxyl group]

As the carboxyl group-containing resin contained in the resin composition of the present invention, a known resin compound containing a carboxyl group in the molecule can be used. By the presence of a carboxyl group, the resin composition can be rendered alkali-developable. From the viewpoint of the photocuring property of the resin composition of the present invention or the resistance to development, it is preferable to have an ethylenically unsaturated bond in the molecule other than a carboxyl group. However, a carboxyl group-containing water having no ethylenically unsaturated double bond may also be used. When the carboxyl group-containing resin has no ethylenically unsaturated bond, it is necessary to use a compound having at least one ethylenic unsaturated group (photopolymerizable compound) in the molecule in order to make the composition photo-curable. The ethylenically unsaturated double bond is preferably derived from acrylic acid or methacrylic acid or a derivative thereof.

Specific examples of the carboxyl group-containing resin that can be used in the resin composition of the present invention include the following compounds (any of oligomers and polymers) listed below.

(1) A carboxyl group-containing resin obtained by copolymerizing an unsaturated carboxylic acid such as (meth) acrylic acid with an unsaturated group-containing compound such as styrene,? -Methylstyrene, lower alkyl (meth) acrylate or isobutylene.

(2) a diisocyanate compound such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate, or an aromatic diisocyanate, a carboxyl group-containing dialcohol compound such as dimethylolpropionic acid or dimethylolbutanoic acid, and a polycarbonate- A carboxyl group-containing urethane (polyol), a polyol, a polyester polyol, a polyolefin polyol, an acrylic polyol, a diol compound such as a bisphenol A alkylene oxide adduct diol, a compound having a phenolic hydroxyl group and an alcoholic hydroxyl group Suzy.

(3) a process for producing a polyisocyanate compound by reacting a diisocyanate compound such as an aliphatic diisocyanate, a branched aliphatic diisocyanate, an alicyclic diisocyanate or an aromatic diisocyanate with a polycarbonate-based polyol, a polyether-based polyol, A terminal carboxyl group-containing urethane resin obtained by reacting an acid anhydride with a terminal of a urethane resin by a heavier reaction of a diol compound such as an A-alkylene oxide adduct diol, a phenolic hydroxyl group and a compound having an alcoholic hydroxyl group.

(4) a bifunctional epoxy resin such as a bisphenol A type epoxy resin, a hydrogenated bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a beccylenol type epoxy resin and a biphenol type epoxy resin (Meth) acrylate or a partial acid anhydride thereof, a carboxyl group-containing dialcohol compound and a diol compound.

(5) In the synthesis of the resin of the above (2) or (4), a compound having one hydroxyl group and at least one (meth) acryloyl group in the molecule such as hydroxyalkyl (meth) (Meth) acrylated carboxyl group-containing urethane resin.

(6) In the synthesis of the resin of the above (2) or (4), one isocyanate group and one or more (meth) acryloyl groups in the molecule, such as molar reactants such as isophorone diisocyanate and pentaerythritol triacrylate, Is subjected to terminal (meth) acrylation to form a carboxyl group-containing urethane resin.

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

(8) A photosensitive carboxyl group-containing resin obtained by reacting a polyfunctional epoxy resin obtained by epoxidizing a hydroxyl group of a bifunctional (solid) epoxy resin with epichlorohydrin, with (meth) acrylic acid and adding a dibasic acid anhydride to the generated hydroxyl group.

(9) A carboxyl group-containing polyester resin in which a dicarboxylic acid is reacted with a polyfunctional oxetane resin, and a dibasic acid anhydride is added to the resulting primary hydroxyl group.

(10) A process for producing a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in a molecule with an alkylene oxide such as ethylene oxide, propylene oxide and / or a cyclic carbonate compound such as ethylene carbonate or propylene carbonate, A carboxyl group-containing photosensitive resin obtained by partial esterification with a carboxylic acid and reacting the obtained reaction product with a polybasic acid anhydride.

(11) A process for producing a polyalkylene oxide by reacting a polybasic acid anhydride with a reaction product obtained by reacting a compound having a plurality of phenolic hydroxyl groups in a molecule with an alkylene oxide such as ethylene oxide, propylene oxide and / or a cyclic carbonate compound such as ethylene carbonate or propylene carbonate Containing resin.

(12) The resin composition as described in any one of (1) to (11) above, wherein one epoxy group in the molecule such as glycidyl (meth) acrylate and? -Methyl glycidyl (meth) And a compound having a diazo group is further added to the photosensitive resin composition.

In the present specification, (meth) acrylate is generically referred to as acrylate, methacrylate and a mixture thereof, and the same applies to other similar expressions.

Since the carboxyl group-containing resin has a large number of carboxyl groups in the side chain of the backbone polymer, development with an aqueous alkaline solution becomes possible.

The acid value of the carboxyl group-containing resin is preferably in the range of 20 to 200 mg KOH / g, and more preferably in the range of 40 to 150 mg KOH / g. When the acid value of the carboxyl group-containing resin is within the above range, the alkali solubility is good and the patterning by the alkali development is facilitated.

The weight average molecular weight of the carboxyl group-containing resin varies depending on the resin skeleton, but is preferably 1,000 to 100,000, more preferably 3,000 to 50,000. When the molecular weight is within the above range, alkali solubility is good and patterning by alkali development is facilitated.

[Thermal curing component]

The thermosetting component has a functional group capable of addition reaction with a carboxyl group by heat. As the thermosetting component, for example, a compound having a cyclic (thio) ether group is preferable, and an epoxy resin, a polyfunctional oxetane compound and the like can be given.

The epoxy resin is a resin having an epoxy group, and any known epoxy resin can be used. A bifunctional epoxy resin having two epoxy groups in the molecule, and a polyfunctional epoxy resin having a large number of epoxy groups in the molecule. It may also be a hydrogenated epoxy resin.

Specific examples include bisphenol A epoxy resin, brominated epoxy resin, novolak epoxy resin, bisphenol F epoxy resin, hydrogenated bisphenol A epoxy resin, glycidylamine epoxy resin, hydantoin epoxy resin, alicyclic epoxy resin, Epoxy resin, trihydroxyphenylmethane type epoxy resin, biquileneol type or biphenol type epoxy resin or a mixture thereof; A bisphenol S type epoxy resin, a bisphenol A novolak type epoxy resin, a tetraphenylol ethane type epoxy resin, a heterocyclic epoxy resin, a diglycidyl phthalate resin, a tetraglycidylsilaneoyl ethane resin, a naphthalene group containing epoxy resin, An epoxy resin having a chloropentadiene skeleton, a glycidyl methacrylate copolymer-based epoxy resin, a copolymerized epoxy resin of cyclohexylmaleimide and glycidyl methacrylate, and a CTBN-modified epoxy resin.

In addition, as a thermosetting component, a known compound such as a maleimide compound, a block isocyanate compound, an amino resin, a benzoxazine resin, a carbodiimide resin, a cyclocarbonate compound, or an episulfide resin may be added.

One kind of such thermosetting component may be used alone, or two or more kinds may be used in combination. The blending amount of the thermosetting component is preferably 1: 0.1 to 1:10 in terms of equivalence ratio (carboxyl group: thermal reactive group such as epoxy group) to the carboxyl group-containing resin. By setting the mixing ratio within such a range, the development becomes favorable and a fine pattern can be easily formed. It is more preferable that the equivalent ratio is 1: 0.2 to 1: 5.

[Flame Retardant]

As the flame retardant constituting the resin composition of the present invention, a known flame retardant may be used. Examples of the flame retardant include phosphorus-containing compounds such as phosphoric acid esters and condensed phosphoric acid esters, phosphorus-containing (meth) acrylates, phosphorus-containing compounds having phenolic hydroxyl groups, cyclic phosphazene compounds, phosphazene oligomers and phosphinic acid metal salts, An antimony compound such as antimony, a halide such as pentabromodiphenyl ether or octabromodiphenyl ether, or a metal hydroxide such as aluminum hydroxide or magnesium hydroxide. These flame retardants may be used alone or in combination of two or more.

[Ion capturing agent]

The ion scavenger contained in the resin composition of the present invention is a mixture of hydrotalcite ion scavenger and hydrotalcite ion scavenger.

As the hydrotalcite-based ion scavenger included in the resin composition of the present invention, hydrotalcite and hydrotalcite-like compounds can be suitably used. Hydrotalcite and hydrotalcite-like compounds, for example, the base layer positively charged _{[Mg 1-X Al X (} OH) 2] a charged intermediate layer as ^{X +} and a negative _{[(CO 3) X / 2} · mH 2 O] ^X- . Many divalent and trivalent metals take the same layered structure as these metals, and the general structural formula is represented by the following formula (I).

^Wherein M < ²⁺ &gt; represents a divalent metal cation, M &lt; 3 ⁺ &gt; represents a trivalent metal cation, A &lt; ^n- &gt; represents an anion of n, and subscripts of each element and atomic group represent a ratio of each element and an atomic group, 0 &lt; X &lt; = 0.33. m is 0, but it is largely changed by dehydration.

Hydrotalcite and hydrotalcite-like compounds Specific examples of the site, if indicator light _{(Indigirite) Mg 2 Al 2 [} (CO 3) 4 (OH) 2] · 15H 2 O, Fe 2+ 4 Al 2 [(OH) 12 CO _3] · 3H ₂ O, kwinti nitro _{(Quintinite) Mg 4 Al 2 (} OH) 12 CO 3 · H 2 O, Manas glyphosate _{(Manasseite) Mg 6 Al 2 [} (OH) 16 CO 3] · 4H 2 O, eseujeyi Oe Granite ^{_{(SjOegrenite) Mg 6 Fe 3+ 2}} [(OH) 16 CO 3] · 4H 2 O, the nitro Slope _{(Zaccagnaite) Zn 4 Al 2 (} CO 3) (OH) 12 · 3H 2 O, having Desautelsite Mg ₆ Mn ³⁺ ₂ [(OH) ₁₆ CO ₃ ] .4H ₂ O, Hydrotalcite Mg ₆ Al ₂ [(OH) ₁₆ CO ₃ ] 4H ₂ O, Pyroaurite Mg ₆ Fe ³⁺ ₂ [(OH) ₁₆ CO ₃ ] 4H ₂ O, Reevesite Ni ₆ Fe ³⁺ ₂ [(OH) ₁₆ CO ₃ ] 4H ₂ O, stitchite Stichtite Mg ₆ Cr ₂ [(OH) ₁₆ CO ₃ ] 4H ₂ O, Takovite Ni ₆ Al ₂ [(OH) ₁₆ CO ₃ ] 4H ₂ O and the like.

Commercially available products include those manufactured by Kyowa Chemical Industry Co., Ltd.; Synthetic hydrotalcite-like compounds such as HT-1, HT-7 and HT-P of STABIACE series manufactured by Sakai Kagaku Co., Ltd. can be mentioned.

These hydrotalcite-based ion trapping agents may be used singly or in combination of two or more species.

As the ion trapping agent other than the hydrotalcite system contained in the resin composition of the present invention, a known ion trapping agent can be used. As the ion trapping agent other than the hydrotalcite system, a cation exchange type, an anion exchange type, or both ion exchange type can be used.

Specifically, inorganic particles containing Zr-based compounds, inorganic particles containing Sb-based compounds, inorganic particles containing Bi-based particles, and the like can be given. In addition, inorganic particles containing a binary system of an Sb-based compound and a Bi-based compound, inorganic particles containing a binary system of an Mg-based compound and an Al-based compound, inorganic particles containing a binary system of a Zr- And inorganic particles containing a ternary system of a Zr-based compound, a Mg-based compound and an Al-based compound. Among them, inorganic particles containing a Zr-based compound, inorganic particles containing a binary system of a Zr-based compound and a Bi-based compound, inorganic particles containing a Zr-based compound, a Mg-based compound and an Al- Are preferable.

IXE-100, IXE-300, IXE-500, IXE-550, IXE-800, IXE-600, IXE-6107, and IXE-IXE-100 manufactured by Toagosei Co., -6136, IXEPLAS-A1 and IXEPLAS-B1.

These ionic scavengers other than the hydrotalcite system may be used singly or in combination of two or more species.

In the present invention, it is essential that the ion trapping agent is a mixture of a hydrotalcite-based ion trapping agent and an ion trapping agent other than hydrotalcite-based ion trapping agent. By using these ion trapping agents, insulation reliability such as ion migration resistance and flame retardancy can be highly compatible. This is considered to be due to the following reasons. When an ion trapping agent of hydrotalcite system is blended to improve insulation reliability, particularly ion migration resistance, flame retardancy is lowered, but when a hydrotalcite ion trapping agent is added in such an amount that the flame retardancy is not lowered , The ion migration tolerance becomes insufficient. Therefore, it is considered that, when ion trapping agents other than the hydrotalcite system having flame retardancy are used in combination, insufficient ion migration resistance can be compensated while maintaining flame retardancy. Therefore, according to the present invention, insulation reliability, particularly ion migration resistance and flame retardancy, can be highly compatible.

The mixing ratio of the hydrotalcite-based ion scavenger to the ion scavenger other than the hydrotalcite-based hydrocarbons is in the range of 100: 10 to 100: 500, preferably 100: 50 to 100: 400 , More preferably from 100: 100 to 100: 400. The total amount of the ion trapping agent is 1 to 50% by mass, preferably 2 to 40% by mass, and more preferably 2 to 20% by mass based on the total solid content of the resin composition.

The resin composition of the present invention may further contain at least one of a photopolymerization initiator and a compound having an ethylenic unsaturated group.

(Photopolymerization initiator)

As the photopolymerization initiator, known ones can be used, and examples thereof include benzoin compounds, acylphosphine oxide compounds, acetophenone compounds,? -Aminoacetophenone compounds, oxime ester compounds, thioxanthone compounds and the like have.

Particularly, when used in a PEB process after light irradiation described below, a photopolymerization initiator having a function as a photobase generator is also suitable. Further, in this PEB step, a photopolymerization initiator and a photobase generator may be used in combination.

A photopolymerization initiator having a function as a photobase generator is a photopolymerization initiator which has a molecular structure that is changed by irradiation of light such as ultraviolet rays or visible light or which is capable of functioning as a catalyst for the addition reaction of a thermosetting component Or more basic substance. As the basic substance, for example, secondary amine and tertiary amine can be mentioned.

Examples of the photopolymerization initiator having a function as a photobase generator include, for example, an? -Aminoacetophenone compound, an oxime ester compound, an acyloxyimino group, an N-formylated aromatic amino group, a N-acylated aromatic amino group, A compound having a substituent such as a benzoate, an alkoxybenzylcarbamate group and the like. Of these, oxime ester compounds and? -Amino acetophenone compounds are preferable, and oxime ester compounds are more preferable. As the? -amino acetophenone compound, those having at least two nitrogen atoms are particularly preferred.

The? -amino acetophenone compound may be any one that has a benzoin ether bond in its molecule and undergoes cleavage in the molecule upon irradiation with light to generate a basic substance (amine) that exerts a curing catalytic action. Specific examples of the? -amino acetophenone compound include (4-morpholinobenzoyl) -1-benzyl-1-dimethylaminopropane (trade name: Irgacure 369, BASF Japan) Methyl-1-morpholinoethane (trade name: Irgacure 907, BASF Japan), 2- (dimethylamino) -2 - [(4- methylphenyl) methyl] -Morpholinyl) phenyl] -1-butanone (trade name: Irgacure 379, manufactured by BASF Japan), or a solution thereof can be used.

As the oxime ester compound, any compound capable of generating a basic substance by light irradiation can be used. Examples of oxime ester compounds include CGI-325, Irgacure OXE01, Irgacure OXE02, N-1919 and NCI-831 manufactured by BASF Japan. Also, compounds having two oxime ester groups in the molecule described in Japanese Patent No. 4,344,400 can be suitably used.

One such photopolymerization initiator may be used alone, or two or more photopolymerization initiators may be used in combination. The blending amount of the photopolymerization initiator in the resin composition is 0.1 to 30 parts by mass, preferably 0.5 to 20 parts by mass, based on 100 parts by mass of the carboxyl group-containing resin in terms of solid content. When the amount is in the range of 0.1 to 30 parts by mass, the curing balance between the surface of the coating film and the deep portion becomes good, and sensitivity and resolution can be improved. In addition, the photocurability is improved and the coating film characteristics such as insulation reliability and chemical resistance can be improved. However, when it is used as a resin composition for an adhesive layer of a coverlay of a two-layer structure, a composition not containing a photopolymerization initiator is preferable.

(Compound having an ethylenic unsaturated group)

A compound having an ethylenically unsaturated group (hereinafter also referred to as a photopolymerizable compound) is a compound having at least one ethylenic unsaturated group in the molecule. The photopolymerizable compound assists the polymerization reaction of the ethylenic unsaturated group by irradiation with active energy rays. The ethylenic unsaturated group is preferably derived from (meth) acrylate.

(Meth) acrylate, urethane (meth) acrylate, carbonate (meth) acrylate, epoxy (meth) acrylate, and the like can be used as the photopolymerizable compound . Specific examples thereof include hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; Diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol and propylene glycol; Acrylamides such as N, N-dimethyl acrylamide, N-methylol acrylamide and N, N-dimethylaminopropylacrylamide; Aminoalkyl acrylates such as N, N-dimethylaminoethyl acrylate and N, N-dimethylaminopropyl acrylate; Polyhydric alcohols such as hexanediol, trimethylol propane, pentaerythritol, dipentaerythritol and tris-hydroxyethylisocyanurate, or ethylene oxide adducts thereof, propylene oxide adducts, or? -Caprolactone adducts Polyfunctional acrylates; Polyfunctional acrylates such as phenoxy acrylate, bisphenol A diacrylate and their phenols ethylene oxide adduct or propylene oxide adduct; Polyfunctional acrylates of glycidyl ethers such as glycerin diglycidyl ether, glycerin triglycidyl ether, trimethylol propane triglycidyl ether and triglycidyl isocyanurate; The present invention is not limited to the above, and acrylates and melamine acrylates obtained by directly acrylating a polyol such as a polyether polyol, a polycarbonate diol, a hydroxyl-terminated polybutadiene or a polyester polyol, or a urethane acrylate through a diisocyanate, and And at least one of the respective methacrylates corresponding to the acrylate.

Further, an epoxy acrylate resin obtained by reacting acrylic acid with a polyfunctional epoxy resin such as cresol novolak type epoxy resin may be used as a photopolymerizable compound. Such an epoxy acrylate resin can improve photo-curability without deteriorating the touch-dry composition.

The blending amount of the photopolymerizable compound is 1 to 50 parts by mass, more preferably 3 to 30 parts by mass, based on 100 parts by mass of the carboxyl group-containing resin in terms of solid content. When the blending amount is in the range of 1 to 50 parts by mass, photo-curability and adhesiveness can be improved.

(Polymer resin)

A publicly known polymer resin may be blended in the resin composition of the present invention for the purpose of improving the flexibility and tackiness of the resulting cured product. Examples of the polymer resin include cellulose type, polyester type, phenoxy resin type, polyvinyl acetal type, polyvinyl butyral type, polyamide type, polyamideimide type binder polymer, block copolymer and elastomer. These polymer resins may be used alone or in combination of two or more.

(Inorganic filler)

The resin composition of the present invention may contain an inorganic filler. The inorganic filler is used for inhibiting curing shrinkage of the cured product of the resin composition and improving the properties such as adhesion and hardness. Examples of the inorganic filler include inorganic fillers such as 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 . The inorganic filler may be used singly or in combination of two or more kinds.

(coloring agent)

In the resin composition of the present invention, a colorant may be added. As the coloring agent, publicly known coloring agents such as red, blue, green, yellow, white and black can be used, and any of pigments, dyes and pigments may be used.

(Organic solvent)

In the resin composition of the present invention, an organic solvent may be used for the production of a resin composition or for viscosity adjustment for application to a substrate 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 singly or as a mixture of two or more kinds.

(Other optional components)

In the resin composition of the present invention, components such as a mercapto compound, an adhesion promoter, an antioxidant, and an ultraviolet absorber may be further blended, if necessary. These may be those known in the field of electronic materials. It is also possible to add known additives such as thickening agents for known additives such as finely divided silica, organic bentonite and montmorillonite, antifoaming agents such as silicone type, fluorine type and high molecular type and / or leveling agents, silane coupling agents and rustproofing agents to the above- Can be compounded.

[Dry film]

The dry film of the present invention has a resin layer comprising the resin composition of the present invention. Or a multilayer structure dry film having a layer made of a resin composition other than the resin composition of the present invention.

In the case of dry film formation, for example, the resin composition of the present invention is diluted with an organic solvent, adjusted to an appropriate viscosity, and applied on the carrier film to a uniform thickness on a carrier film by a known method such as a comma coater. Then, it is usually dried at a temperature of 50 to 130 DEG C for 1 to 30 minutes to form a resin layer on the carrier film.

As the carrier film, a plastic film is used. The thickness of the carrier film is not particularly limited, but is generally appropriately selected in the range of 10 to 150 mu m. After the resin layer is formed on the carrier film, a peelable cover film may be further laminated on the surface of the resin layer.

The resin composition or the dry film of the present invention as described above can be used for a resin insulating layer of a printed wiring board, for example, a cover layer or a solder resist. The resin composition of the present invention can also be used as a resin composition for an adhesive layer which is a resin layer in contact with a printed wiring board of a coverlay having a laminated structure of two or more layers.

The coverlay (laminated structure) having the laminated structure of two or more layers is preferably composed of an adhesive layer which is a resin layer in contact with the printed wiring board and a protective layer which is a resin layer that can be patterned by light irradiation of an upper layer thereof. By using the resin composition of the present invention as the adhesive layer of this laminated structure, the laminated structure such as a coverlay including the adhesive layer and the protective layer can be patterned collectively by development, and furthermore, the insulation reliability such as ion migration resistance and the like The flame retardancy can be highly compatible.

Here, the resin composition constituting the protective layer contains a carboxyl group-containing resin (alkali-soluble resin), a photopolymerization initiator, and a thermosetting component, and the composition described in JP-A-2015-155199 have. As the carboxyl group-containing resin (alkali-soluble resin), a carboxyl group-containing resin (alkali-soluble resin) having an imide ring or imide precursor skeleton is preferable.

[Manufacturing method of printed wiring board]

Next, an example of a method for producing a printed wiring board from the resin composition of the present invention will be described based on the process charts of Figs. 1 and 2. Fig. In Figs. 1 and 2, the case where the resin layer has a laminated structure is shown, but it may be a case where only one layer is included.

The manufacturing method of the printed wiring board shown in the process chart of Fig. 1 includes a step (lamination step) of forming a layer of a laminated structure on a printed wiring board on which a conductor circuit is formed, a step of irradiating the layer of the laminated structure with a pattern of active energy And a step of developing the layer of the laminated structure by alkali to form a layer of the patterned laminated structure collectively (developing step). In addition, after the alkali development as required, photo curing or thermosetting (post-curing step) is further performed, and the layer of the laminated structure is completely cured, whereby a highly reliable printed wiring board can be obtained.

The manufacturing method of the printed wiring board shown in the process chart of Fig. 2 includes a step (lamination step) of forming a layer of the laminated structure on the printed wiring board on which the conductor circuit is formed, a step of irradiating the layer of the laminated structure with a pattern of active energy , A step of heating the layer of the laminated structure (a post exposure bake (PEB) step), and a step of alkali development of the layer of the laminated structure to form a layer of the patterned laminated structure ( Developing step). In addition, after the alkali development as required, photo curing or thermosetting (post-curing step) is further performed, and the layer of the laminated structure is completely cured, whereby a highly reliable printed wiring board can be obtained. Particularly, in the case where an imide ring-containing alkali-soluble resin is used for the resin layer 4 (protective layer), it is preferable to use the procedure shown in the process chart of Fig.

Hereinafter, each step shown in Fig. 1 or Fig. 2 will be described in detail.

[Lamination step]

In this step, a resin layer 3 (adhesive layer) made of a resin composition and a resin layer 4 made of a resin composition (protective layer) on the resin layer 3 are formed on the printed wiring board 1 on which the conductor circuit 2 is formed Layer) is formed. Here, each of the resin layers constituting the laminated structure can be obtained by forming the resin layers 3, 4 by, for example, applying the resin composition constituting the resin layers 3, 4 sequentially to the printed wiring board 1 and drying Or the resin composition constituting the resin layers 3 and 4 may be formed into a dry film of a two-layer structure by a method of laminating the resin composition on the printed wiring board 1.

The resin layer is preferably composed of an alkali developing photosensitive resin composition. As the alkali developing type photosensitive resin composition, a known resin composition can be used, and for example, a known resin composition for a cover coat or a solder resist can be used. By thus forming the resin layer not as a single layer but as a laminated structure, a cured product having further excellent impact resistance and flexibility can be obtained.

The method of applying the resin composition to the wiring board may be a known method such as a blade coater, a lip coater, a comma coater, and a film coater. The drying method includes a method in which a hot air circulation type drying furnace, IR, a hot plate, a convection oven, or the like, which is provided with a heat source of a heating method using steam, is used to countercurrently contact hot air in the dryer, Or a known method.

In the case of the lamination method, first, the resin composition is diluted with an organic solvent, adjusted to an appropriate viscosity, applied onto a carrier film, and dried to produce a dry film having a resin layer. Next, a known method of peeling the carrier film after the resin layer is brought into contact with the wiring substrate by a laminator or the like can be mentioned.

[Exposure step]

In this step, the photopolymerization initiator contained in the resin layer 4 is activated in a negative pattern by irradiation of an active energy ray to cure the exposed portion. As the exposure machine, a direct imaging apparatus, an exposure machine equipped with a metal halide lamp, or the like can be used. The mask for exposure on the pattern is a negative type mask.

As the active energy ray used for exposure, laser light or scattered light having a maximum wavelength in the range of 350 to 450 nm is preferably used. By setting the maximum wavelength within this range, the photopolymerization initiator can be activated efficiently. The amount of exposure differs depending on the film thickness and the like, but may be usually from 100 to 1500 mJ / cm ² .

[PEB process]

In this step, after exposure, the resin layer is heated to cure the exposed portion. By this process, a photopolymerization initiator having a function as a photopolymerization initiator is used, or the base layer generated by the exposure process of the resin layer 4 composed of a composition comprising a photopolymerization initiator and a photo- . The heating temperature is, for example, 80 to 140 占 폚. The heating time is, for example, 10 to 100 minutes. Since the resin composition in the present invention is a ring-opening reaction of an epoxy resin by, for example, a thermal reaction, deformation and curing shrinkage can be suppressed as compared with the case where curing proceeds in a photo radical reaction.

[Development process]

In this step, the unexposed portion is removed by alkali development to form a negative patterned insulating film, in particular a coverlay and a solder resist. The developing method can be performed by a known method such as dipping. As the developing solution, an aqueous alkali solution such as sodium carbonate, potassium carbonate, potassium hydroxide, amines, imidazoles such as 2-methylimidazole, aqueous solution of tetramethylammonium hydroxide (TMAH), or a mixture thereof can be used.

[Post-curing process]

This step is to completely heat-cure the resin layer after the developing step to obtain a highly reliable coating film. The heating temperature is, for example, 140 占 폚 to 180 占 폚. The heating time is, for example, 20 to 120 minutes. It may also be irradiated before or after post-curing.

Example

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to the following examples and comparative examples. In the following, " part " and "% " are on a mass basis unless otherwise specified.

(Examples 1 to 14 and Comparative Examples 1 to 6)

&Lt; Production of Resin Composition >

According to the formulations described in Tables 1 to 3, the materials described in Examples and Comparative Examples were each compounded, premixed by a stirrer, and kneaded by a three-roll mill to prepare a curable resin composition. The values in the table are parts by mass unless otherwise specified.

Insulation reliability and flame retardancy were evaluated for the curable resin composition. The evaluation contents are as follows.

<Insulation reliability>

A polyimide substrate (Epinex made by Shin-Nittetsu Kagaku Co., Ltd.) having a copper thickness of 18 占 퐉 with a pattern of L / S = 50/50 占 퐉 was surface-treated using Macblight CB-801Y. The curable resin compositions of Examples 1 to 14 and Comparative Examples 1 to 6 were applied on the entire surface of the polyimide substrate by screen printing, dried at 80 占 폚 for 30 minutes, and cooled to room temperature. The obtained substrate was subjected to total exposure at an exposure amount of 300 mJ / cm ² using an exposure apparatus (HMW-680-GW20) equipped with a metal halide lamp, and a 1 wt% Na ₂ CO ₃ aqueous solution was used at 30 캜, Under the condition of 60 seconds. The substrate was heated and cured at 150 ° C for 60 minutes, and then an electromagnetic wave shielding material was press-bonded to produce an evaluation substrate for insulation reliability.

A bias voltage of DC 50V was applied to the prepared evaluation substrate in the Z-axis direction, and the resistance value was continuously measured in a constant-temperature and humidity bath at 85 ° C and 85% RH to confirm whether or not there was a short circuit, and ion migration resistance was evaluated . The criteria are as follows.

?: No short-circuit occurred after 1000 hours elapsed.

X: Shot occurred within 1000 hours.

<Flammability>

The curable resin compositions of Examples 1 to 14 and Comparative Examples 1 to 6 were entirely coated on a polyimide film substrate (200H, 100H, manufactured by Toray DuPont Co., Ltd.) having a thickness of 50 占 퐉 and a thickness of 25 占 퐉 by screen printing, Dried in 15 minutes, and allowed to cool to room temperature. Similarly, the entire surface was coated and dried at 80 ° C for 20 minutes. With respect to the double-sided coated substrate thus obtained, on both sides using a metal halide lamp with an exposure apparatus (HMW-680-GW20) exposure amount over an exposure, and 1 wt% Na ₂ CO ₃ aqueous solution of 300mJ / cm ² using a 30 ℃ And a spray pressure of 2 kg / cm &lt; ² &gt; for 60 seconds. The two-side coated substrate was heated and cured at 150 ° C for 60 minutes to prepare an evaluation board of flame retardancy.

The manufactured evaluation substrate was subjected to a thin film vertical burning test according to the UL94 standard to evaluate the flame retardancy. The criteria for evaluation were as follows: ○, in which flame retardancy was confirmed based on UL94 standard;

* 1: carboxyl group-containing modified epoxy acrylate resin, nonvolatile matter content 65.0 mass%, solid acid value 100 mgKOH / g (manufactured by Nippon Kayaku Co., Ltd.)

* 2: Biphenyl novolak type epoxy resin (manufactured by Nippon Kayaku Co., Ltd.)

* 3: Phenoxyphosphazene (manufactured by Otsuka Chemical Co., Ltd.)

* 4: Phosphinic acid metal salt (manufactured by Clariant)

* 5: Oxime ester-based photopolymerization initiator (manufactured by BASF Japan)

* 6: Hydrotalcite compound (manufactured by Kyowa Chemical Industry Co., Ltd.)

* 7: Inorganic ion capturing agent (both ion exchange type) (manufactured by Doagosei Co., Ltd.)

* 8: Inorganic ion capturing agent (both ion exchange type) (manufactured by Doagosei Co., Ltd.)

* 9: Inorganic ion capturing agent (cation exchange type) (manufactured by Doagosei Co., Ltd.)

* 10: Inorganic ion capturing agent (both ion exchange type) (manufactured by Doagosei Co., Ltd.)

* 11: Bisphenol A-EO-modified diacrylate (manufactured by Shin Nakamura Chemical Industry Co., Ltd.)

As is clear from the results shown in Tables 1 to 3, in Examples 1 to 14, ion trapping agents other than hydrotalcite based ion hydrotalcite ion trapping agents were used in combination with the hydrotalcite based ion trapping agent, Respectively. On the other hand, in Comparative Examples 1 and 2, since the ion trapping agent was not included, the insulation reliability was lowered. In Comparative Example 3, only a hydrotalcite-based ion trapping agent was used, and insulation reliability was obtained, but the flame retardancy was lowered. In Comparative Examples 4 to 6, only ion trapping agents other than the hydrotalcite system were used, and insulation reliability was lowered. As a result, in these Comparative Examples, insulation reliability and flame retardancy could not be highly compatible.

(Examples 15 and 16, Comparative Examples 7 and 8)

&Lt; Formation of laminated structure &

(Synthesis Example 1: Synthesis of an alkali-soluble resin having an imide ring)

In a separable three-necked flask equipped with a stirrer, a nitrogen introducing tube, a reflux condenser and a cooling ring, 12.2 g of 3,5-diaminobenzoic acid and 12.2 g of 2,2'-bis [4- (4-aminophenoxy) , 30 g of NMP, 30 g of? -Butyrolactone, 27.9 g of 4,4'-oxydiphthalic anhydride and 3.8 g of trimellitic anhydride, and the mixture was stirred at 100 rpm for 4 hours at room temperature under a nitrogen atmosphere. Subsequently, 20 g of toluene was added, and the mixture was stirred for 4 hours while distilling toluene and water at a silicon bath temperature of 180 캜 at 150 rpm to obtain an imide ring-containing alkali-soluble resin solution. Thereafter,? -Butyrolactone was added so that the solid content was 30% by mass. The obtained resin solution had a solid acid value of 86 mgKOH / g and a Mw of 10,000.

&Lt; Adjustment of Resin Composition Constituting Each Layer >

According to the formulations shown in Table 4 below, the materials described in Examples and Comparative Examples were each compounded and premixed with a stirrer, followed by kneading with a three-roll mill to prepare a resin composition for forming an adhesive layer and a protective layer. The values in the table are parts by mass unless otherwise specified.

The resin compositions for the adhesive layers of the respective laminated structures of Examples 15, 16, and Comparative Examples 7 and 8 were the same as the resin compositions of Examples 2, 3, and Comparative Examples 3 and 6 except that the resin composition for the adhesive layer did not include a photopolymerization initiator Respectively.

&Lt; Formation of adhesive layer &

A flexible printed wiring board having a circuit of a copper thickness of 18 mu m was prepared, and CZ-8100 manufactured by MEC Corporation was used to perform preprocessing. Thereafter, the resin composition for each adhesive layer was applied to the pretreated flexible printed wiring board so that the film thickness after drying was 25 mu m. Thereafter, it was dried in a hot air circulation type drying oven at 90 DEG C for 30 minutes to form an adhesive layer made of a resin composition.

<Formation of Protective Layer>

The resin composition for each protective layer was coated on the adhesive layer so that the film thickness after drying was 10 mu m. Thereafter, it was dried in a hot air circulation type drying oven at 90 DEG C for 30 minutes to form a protective layer made of a resin composition.

Thus, a non-cured laminated structure including the adhesive layer and the protective layer described in Examples 15, 16, and Comparative Examples 7 and 8 was formed on the flexible printed wiring substrate.

<Fabrication of Flexible Printed Circuit Board>

The uncured laminated structure on each flexible printed wiring board substrate on which the uncured laminated structure was formed as described above was subjected to front exposure at 500 mJ / cm ² using an exposure apparatus (HMW-680-GW20) equipped with a metal halide lamp Respectively. Then, after carrying out for 30 minutes at 90 ℃ PEB process, by developing (30 ℃, 0.2MPa, 1 wt% Na ₂ CO ₃ solution) is performed for 60 seconds, heat-curing to 150 ℃ × 60 minutes, the cured laminate structure To obtain a flexible printed wiring board.

<Insulation reliability>

Each of the flexible printed wiring boards obtained above was press-bonded with an electromagnetic wave shielding material to produce an evaluation board for insulation reliability.

A bias voltage of DC 50V was applied to the prepared evaluation substrate in the Z-axis direction, and the resistance value was continuously measured in a constant-temperature and humidity bath at 85 ° C and 85% RH to confirm whether or not there was a short circuit, and ion migration resistance was evaluated . The criteria are as follows.

?: No short-circuit occurred after 1000 hours elapsed.

X: Shot occurred within 1000 hours.

<Flammability>

Each of the flexible printed wiring boards obtained above was subjected to a laminated vertical burning test according to the UL94 standard to evaluate flame retardancy. The criteria for evaluation were as follows: ○, in which flame retardancy was confirmed based on UL94 standard;

Flexibility (MIT test)

Each flexible printed wiring board obtained above was subjected to an MIT test (R = 0.38 mm / using a substrate of 12.5 占 퐉 of UFIREX made by UBE KOGAN CO., LTD.) To evaluate the flexibility. A case in which the bending is performed for 120 cycles or more is defined as &amp; cir &amp;. In this case, flexibility as a flexible wiring board can be satisfied. And when it was less than 120 cycles, it was evaluated as x.

The obtained results are shown in Table 4 below.

* 12: Polyimide resin of Synthesis Example 1

* 13: Bisphenol A type epoxy resin (molecular weight: 900) (manufactured by Mitsubishi Chemical Corporation)

* 14: bisphenol A type epoxy resin, epoxy equivalent 190, mass average molecular weight 380 (manufactured by Mitsubishi Chemical Corporation)

As is clear from the results shown in Table 4, in Examples 15 and 16, a hydrotalcite ion trapping agent and a hydrotalcite ion trapping agent were used together in the resin composition for an adhesive layer, The flexible printed wiring board having the laminated structure thus formed had both good insulation reliability and flame retardancy, and had good bendability. On the other hand, in Comparative Example 7, only the hydrotalcite ion trapping agent was used in the resin composition for the adhesive layer, and the flexible printed wiring board having the laminated structure formed by using the same had the insulation reliability, but the flame retardancy was lowered. In Comparative Example 8, only the ion trapping agent other than the hydrotalcite-based resin was used in the resin composition for the adhesive layer, and the flexible printed wiring board having the laminated structure formed by using the ion trapping agent deteriorated the insulation reliability. As a result, in these Comparative Examples, the insulation reliability and flame retardancy of the flexible printed wiring board could not be highly compatible.

1: Printed wiring board
2: conductor circuit
3: Resin layer (adhesive layer)
4: resin layer (protective layer)
5: Mask

Claims (9)

A curable resin composition containing a carboxyl group-containing resin, a thermosetting component, a flame retardant and an ion scavenger, wherein the ion scavenger is a mixture of a hydrotalcite-based ion scavenger and an ion scavenger other than hydrotalcite- . The curable resin composition according to claim 1, wherein the mixing ratio of the hydrotalcite-based ion scavenger to the ion scavenger other than the hydrotalcite-based scavenger is in the range of 100: 10 to 100: 500 on a mass basis. The curable resin composition according to claim 1, further comprising at least one of a photopolymerization initiator and a compound having an ethylenic unsaturated group. The curable resin composition according to claim 1, which is a photosensitive resin composition comprising a photopolymerization initiator. The curable resin composition according to claim 1, wherein the thermosetting component is a cyclic (thio) ether compound. The curable resin composition according to claim 1, which is used for forming at least one of a coverlay and a solder resist. A dry film having a resin layer formed by applying and drying the curable resin composition of claim 1 on a film. A cured product obtained by curing the resin layer of the curable resin composition according to claim 1 or the dry film according to claim 7. A printed wiring board comprising the cured product according to claim 8.

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