JP6764680B2 - A novel photosensitive resin composition and its manufacturing method, and a flexible printed wiring board using it and its manufacturing method - Google Patents

Description

The present invention relates to a photosensitive resin composition and a method for producing the same, and a flexible printed wiring board using a cured film of the photosensitive resin composition and a method for producing the same.

Generally, a film-shaped printed wiring board (hereinafter abbreviated as a flexible printed wiring board) mounted on a small device such as a mobile phone or a digital camera is described in (1) a circuit forming process of a copper-clad laminate, (1). 2) Circuit board protection process with coverlay and cover coat, (3) Surface treatment process for copper foil exposed part and component mounting part, (4) Reinforcing plate bonding process, (5) Punching, etc. Manufactured by going through the outer shape processing process of. After that, various surface treatment steps are selected for (6) copper foil exposed parts and component mounting parts according to the application, and gold-plated flexible printed wiring boards having switch contacts and anisotropic conductive film (ACF) connection terminals. The flexible printed wiring board that is treated and mounted at high density is subjected to gold plating treatment and rust prevention (OSP) treatment.

In particular, in the step (2) above, a photosensitive resin composition having excellent insulation, heat resistance, solvent resistance, flame retardancy, etc. is attached on a circuit board in the form of a film or applied in a liquid form to obtain a photosensitive resin. After forming the film of the composition, it is exposed, developed, and heated by photographic technology to easily form a fine pattern (insulating film) and protect the circuit board.

As the coverlay, a coverlay film obtained by applying an adhesive to a polyimide film or the like has been used. When this coverlay film is adhered to a flexible circuit board, an opening is provided in advance at the terminal portion of the circuit or the joint portion with the component by a method such as punching, and after alignment, thermocompression bonding is performed by a hot press or the like. Although it is common, it is difficult to provide a highly accurate opening in a thin coverlay film. In addition, since the alignment at the time of bonding is often performed manually, workability and position accuracy are poor, and since the coverlay film is attached to unnecessary parts, there are many discarded parts and there is a problem in cost. On the other hand, a solder resist or the like is used as a cover coat that is advantageous in terms of cost, and has a thermosetting solder resist that directly forms a pattern by screen printing or the like, or has a photosensitive function especially when fine processing is required. Solder resist is preferably used.

In recent years, as electronic devices have become smaller and thinner, printed wiring boards have become more sophisticated and complex, and in order to save space, they can withstand severe bending and have low resilience so that they do not repel when assembled. Gender is also required as an important characteristic. Therefore, for the purpose of improving the bendability after reflow, a curable resin composition using a carboxyl group-containing resin having a phenol novolac skeleton and a carboxyl group-containing resin having a urethane bond as a binder polymer (for example, Patent Document 1). , PCT resistance, HAST resistance, electrolytic gold plating resistance, thermal shock resistance, and a photosensitive resin composition for semiconductors containing a filler, an ion adsorbent, and a core-shell particle type elastomer or a silicon elastomer for the purpose of ensuring flexibility at the same time. (For example, Patent Document 2), a reaction product of a polyhydric alcohol, a diisocyanate compound, a lactone compound, and a (meth) acrylate compound having a hydroxyl group for the purpose of ensuring warpage, resilience, tackiness, and workability during component mounting. A photosensitive resin composition containing (for example, Patent Document 3), a photosensitive resin composition using a polyimide having a siloxane skeleton, and a photosensitive dry film (for example, Patent Document 4) have been studied.

JP 2015-199907 (Solar Ink Mfg. Co., Ltd.) JP-A-2015-49517 (Casey Corporation) JP-A-2014-59339 (Hitachi Chemical Co., Ltd.) JP-A-2009-25699 (Kaneka)

However, especially in photosensitive solder resists, an insulating film is formed through two types of curing reactions: a photocuring reaction by exposure and a thermosetting reaction for crushing a developable group that affects insulation reliability. Since two types of curing reactions are used, the curing shrinkage tends to be large, and the photosensitive resin compositions of Patent Documents 1 to 3 can improve warpage when an insulating film is formed on a recent thinner flexible printed wiring board. On the other hand, it is insufficient. Further, even if the warp is small after the thermosetting reaction, the warp may become a problem in the subsequent mounting process. For example, in a hot press crimping process with an anisotropic conductive film (hereinafter abbreviated as ACF) or a solder reflow process, when the flexible printed wiring board is treated at a temperature higher than that of the solder resist thermosetting process, it is insulated. In most cases, the warpage became large and manifested due to the difference in the cured state between the surface layer and the inner layer of the coating film damaged by the reaction of a small amount of unreacted residues in the film and repeated chemical treatment. .. Further, when a raw material having a series cone or a siloxane skeleton is contained in the composition as in Patent Document 4, the warp is small even after the mounting process, but the adhesion to the reinforcing plate or the shielding material is insufficient. Furthermore, there are many problems for practical use due to problems such as process contamination due to bleeding of low molecular weight components.

In view of the above problems, a photosensitive resin that not only retains properties such as insulation and adhesion as a circuit protection film, but also has excellent breakage resistance, low warpage, and low resilience in the thermosetting reaction and the subsequent mounting process. An object of the present invention is to provide a composition, a cured film, a flexible printed wiring board with a cured film, and a method for producing the same.

The inventors of the present application are photosensitive resin compositions containing (A) a base binder polymer, (B) a composition for modifying an insulating film, (C) a photopolymerization initiator, and (D) a solvent.
The (A) base binder polymer is selected from (a1) one or more active energy ray reactive groups in the molecule and an ether bond, an ester bond, a carbonate bond, a urethane bond, an imide bond, a urea bond and an amic acid bond. A compound having more than one kind of structure and (a2) one or more carboxyl groups in the molecule and one or more kinds of structures selected from ether bond, ester bond, carbonate bond, urethane bond, imide bond, urea bond and amic acid bond. Includes two types of compounds with
Further, by adopting the constitution of the photosensitive resin composition characterized in that the composition for modifying the insulating film (B) contains two or more kinds of particles having different volume average particle diameters, the insulating property as a circuit protective film is obtained. It has been found that it not only retains properties such as adhesion, but also has excellent breakage resistance, low warpage, and low resilience in the thermosetting reaction and the subsequent mounting process.

That is, the present invention is a photosensitive resin composition containing (A) a base binder polymer, (B) a composition for modifying an insulating film, (C) a photopolymerization initiator, and (D) a solvent.
The (A) base binder polymer is selected from (a1) one or more active energy ray reactive groups in the molecule and an ether bond, an ester bond, a carbonate bond, a urethane bond, an imide bond, a urea bond and an amic acid bond. A compound having more than one kind of structure and (a2) one or more carboxyl groups in the molecule and one or more kinds of structures selected from ether bond, ester bond, carbonate bond, urethane bond, imide bond, urea bond and amic acid bond. Includes two types of compounds with
Further, the composition for modifying the insulating film (B) is a photosensitive resin composition characterized by containing two or more kinds of particles having different volume average particle diameters.

Further, the composition for modifying the insulating film (B) is characterized by containing organic polymer particles (b1) having a volume average particle diameter of less than 1 μm and organic polymer particles (b2) having a volume average particle diameter of 1 μm or more. It is preferably a photosensitive resin composition.

Further, the organic polymer particles in the composition for modifying the insulating film (B) are at least one selected from core-shell polymer particles, organic-inorganic composite particles, organic particles and crosslinked polymer particles. It is preferably an insulating resin composition.

Further, the composition for modifying the insulating film (B) contains at least organic polymer particles and a compound that can be a dispersion solvent and / or a dispersion medium, and 70% or more of the organic polymer particle components are dispersed in the state of primary particles. It is preferable that the photosensitive resin composition is characterized by the above.

Further, it is preferable that the photosensitive resin composition is a photosensitive resin composition further containing (E) a colorant.

Further, it is preferable that the photosensitive resin composition is a photosensitive resin composition characterized by further containing a filler containing the phosphorus element (F).

The present invention also relates to a cured film which is a cured product of a photosensitive resin composition.

The present invention also relates to a method for producing a cured film, which comprises curing a photosensitive resin composition with at least one of light and heat active energy rays.

The present invention also relates to a flexible printed wiring board having the cured film.

The present invention also relates to a method for manufacturing a flexible printed wiring board, which comprises forming a photosensitive resin composition as an insulating film.

According to the present invention, not only can the characteristics such as insulation and adhesion as a circuit protective film be maintained, but also the cured film and insulation having excellent breakage resistance, low warpage, and low resilience in the thermosetting reaction and the subsequent mounting process. It is possible to provide a polyimide with a film and a flexible printed wiring board with an insulating film.

It is a schematic diagram which measures the amount of warpage of a film.

The present invention is a photosensitive resin composition containing (A) a base binder polymer, (B) a composition for modifying an insulating film, (C) a photopolymerization initiator, and (D) a solvent.
The (A) base binder polymer is selected from (a1) one or more active energy ray reactive groups in the molecule and an ether bond, an ester bond, a carbonate bond, a urethane bond, an imide bond, a urea bond and an amic acid bond. A compound having more than one kind of structure and (a2) one or more carboxyl groups in the molecule and one or more kinds of structures selected from ether bond, ester bond, carbonate bond, urethane bond, imide bond, urea bond and amic acid bond. Includes two types of compounds with
Further, the composition for modifying the insulating film (B) is a photosensitive resin composition characterized by containing two or more kinds of particles having different volume average particle diameters.
The present inventors have found that the photosensitive resin composition of the present invention is excellent in various properties, but it is speculated that this may be due to the following reasons.

The photosensitive resin composition is a complicated composition containing a photocuring component and a thermosetting component at the same time, and the process of protecting the circuit board by the cover coat goes through a multi-step process of printing-exposure-development-thermosetting. Therefore, unreacted cured components tend to remain in the composition. This is because the photocrosslinking reaction due to exposure first proceeds, which may hinder the subsequent thermosetting reaction. If it is a simple substance reaction, the curing reaction is not completed even under thermosetting conditions in which the reaction is sufficiently completed. there is a possibility. Further, the use of a thermosetting resin or a curing catalyst having high potential to secure a sufficiently wide developing window in the drying-exposure-developing process is also one of the factors that make it easy for unreacted components to remain. As described above, it is very difficult to completely eliminate unreacted components in the photosensitive cover coat. Therefore, when a higher temperature is applied in the mounting process (heat press or reflow process) after heat curing, the curing reaction of unreacted components proceeds, resulting in curing shrinkage, and as a result, the flexible printed wiring board is covered. It warps in the direction. On the other hand, in the present invention, by including two or more kinds of (B) insulating film modifying compositions having different volume particle diameters, a dense coating film having little volume change is formed, and further, the insulating film modifying composition. Even if curing shrinkage occurs due to the stress relaxation effect, it is presumed that the change in the cured film in the mounting process can be suppressed because it has the effect of sufficiently canceling it. Further, the following curing shrinkage occurs in various processes even when the flexible printed wiring board is manufactured. (1) Ink printing-drying shrinkage in the drying process, (2) curing shrinkage associated with the photocuring reaction in the exposure process, (3) curing shrinkage associated mainly with the thermosetting reaction in the development-thermosetting process, (4) electroless Gold plating process-Drying shrinkage of the drying process, etc. The photosensitive resin composition of the present invention also exerts a sufficient effect in these steps as described above.

Furthermore, the dense packing structure of the two types (B) insulating film modification compositions suppresses the molecular motion of the polymer chains of the cured composition film, so that they are thermally decomposed even when a high temperature is applied in the mounting process. It is difficult, and it is presumed that the original flexibility of the cured film is not impaired because both the components of (A) the base binder polymer and the two types (B) the composition for modifying the insulating film are composed of organic components. Therefore, as an approach to improve heat resistance and low warpage, it is excellent in warpage improvement without high filling of general inorganic fillers, cross-linking of unnecessary main chain components and increase in aromatic ring amount, and sufficient heat resistance and chemical resistance. Is considered to be able to be achieved.

Further, further excellent effects can be obtained by selecting a colorant, a flame retardant, a thermosetting resin, or the like.
Hereinafter, the invention of the present application will be described in detail.

[(A) Base binder polymer]
The (A) base binder polymer of the present invention is a compound that is soluble in an organic solvent formed by a polymerization reaction of two or more monomers, and has a molecular weight of 1,000 or more and 1,000,000 or less. (A1) It has at least one active energy ray-reactive group in the molecule and one or more structures selected from ether bond, ester bond, carbonate bond, urethane bond, imide bond, urea bond and amic acid bond. Two of a compound and (a2) a compound having at least one carboxyl group in the molecule and one or more structures selected from an ether bond, an ester bond, a carbonate bond, a urethane bond, an imide bond, a urea bond and an amic acid bond. It is not particularly limited as long as it contains a kind of compound. (Hereinafter, a compound having at least one active energy ray reactive group in the molecule and one or more structures selected from an ether bond, an ester bond, a carbonate bond, a urethane bond, an imide bond, a urea bond and an amic acid bond Base binder polymer (a1), a compound having at least one carboxyl group in the molecule and one or more structures selected from ether bond, ester bond, carbonate bond, urethane bond, imide bond, urea bond and amic acid bond. May be referred to as a base binder (b1).)

The organic solvent is not particularly limited, and is, for example, a sulfoxide solvent such as dimethyl sulfoxide or diethyl sulfoxide, a formamide solvent such as N, N-dimethylformamide, N, N-diethylformamide, N, N-dimethylacetamide, etc. Examples thereof include acetamide-based solvents such as N and N-diethylacetamide, pyrrolidone-based solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone, hexamethylphospholamide, and γ-butyrolactone. Further, if necessary, these organic polar solvents can be used in combination with aromatic hydrocarbons such as xylene and toluene.

Further, for example, methyl monoglime (1,2-dimethoxyethane), methyl diglime (bis (2-methoxyether) ether), methyl triglime (1,2-bis (2-methoxyethoxy) ethane), methyl tetraglime. (Bis [2- (2-methoxyethoxyethyl)] ether), ethyl monoglime (1,2-diethoxyethane), ethyl diglime (bis (2-ethoxyethyl) ether), butyl diglime (bis (2) -Symmetric glycol diethers such as (butoxyethyl) ether), methyl acetate, ethyl acetate, isopropyl acetate, n-propyl acetate, butyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate (also known as diethylene glycol monoethyl ether acetate). , Carbitol acetate, 2- (2-butoxyethoxy) ethyl acetate)), diethylene glycol monobutyl ether acetate, 3-methoxybutyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, propylene Acetates such as glycol diacetate and 1,3-butylene glycol diacetate, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, propylene glycol n-butyl ether. , Dipropylene glycol n-butyl ether, tripylene glycol n-propyl ether, propylene glycol phenyl ether, dipropylene glycol dimethyl ether, 1,3-dioxolane, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethyl of ethylene glycol Examples thereof include ether solvents such as ether.

The organic solvent solubility, which is an index of solubility in an organic solvent, can be measured as a part by weight of a resin that dissolves in 100 parts by weight of the organic solvent, and dissolves in 100 parts by weight of the organic solvent. If the weight of the resin is 5 parts by weight or more, it can be made soluble in an organic solvent. The method for measuring the solubility of an organic solvent is not particularly limited. For example, 5 parts by weight of a resin is added to 100 parts by weight of an organic solvent, the mixture is stirred at 40 ° C. for 1 hour, cooled to room temperature and left for 24 hours or more. It can be measured by a method of confirming that the solution is uniform without the generation of insoluble matter or precipitate.
The weight average molecular weight of the (A) base binder of the present invention can be measured by, for example, the following method.

(Measurement of weight average molecular weight)
Equipment used: Tosoh HLC-8220 GPC equivalent Column: Tosoh TSK gel Super AWM-H (6.0 mm ID x 15 cm) x 2 Guard columns: Tosoh TSK guard volume Super AW-H
Eluent: 30 mM LiBr + 20 mM H3PO4 in DMF
Flow velocity: 0.6 mL / min
Column temperature: 40 ° C
Detection conditions: RI: Polarity (+), Response (0.5 sec)
Sample concentration: Approximately 5 mg / mL
Standard product: PEG (polyethylene glycol).

By controlling the weight average molecular weight within the above range, the flexibility and chemical resistance of the obtained insulating film are excellent, which is preferable. When the weight average molecular weight is 1,000 or less, the flexibility and chemical resistance may decrease, and when the weight average molecular weight is 1,000,000 or more, the viscosity of the resin composition may increase.

Examples of the polymerization reaction include chain polymerization, sequential polymerization, living polymerization, addition polymerization, polycondensation, addition condensation, radical polymerization, ion polymerization, cationic polymerization, anion polymerization, coordination polymerization, ring-opening polymerization, and copolymerization. Be done.

The base binder polymer (A) in the present invention is blended so as to be 10 to 70 parts by weight with respect to 100 parts by weight of the total solid content of the components (A) to (F) and other components. , The photosensitive resin composition is preferable in that the photosensitivity and the adhesion to the low warp polyimide are improved.

When the amount of the base binder polymer (A) is less than the above range, the alkali resistance of the insulating film may be lowered, and the contrast at the time of exposure / development may be difficult to obtain. Further, when the amount of the base binder polymer (A) is larger than the above range, the stickiness of the coating film obtained by applying the resin composition on the substrate and drying the solvent becomes large, so that the productivity is lowered. In addition, the insulating film may become brittle and easily cracked due to the excessively high crosslink density. Within the above range, the resolution at the time of exposure / development can be set to the optimum range.

(Base binder polymer (a1))
The base binder polymer (a1) of the present invention is one kind selected from one or more active energy ray reactive groups in the molecule and an ether bond, an ester bond, a carbonate bond, a urethane bond, an imide bond, a urea bond and an amic acid bond. The compound having the above structure is not particularly limited, but is preferably a compound soluble in an organic solvent formed by a polymerization reaction of two or more monomers, and has a molecular weight of 1,000 or more. More preferably, it is a polymer of 1,000,000 or less. Further, it may have one or more partial structures selected from a bisphenol A structure, a bisphenol F structure, a biphenol structure, a biphenol novolak structure, a bisxylenol structure, and a biphenyl novolak structure.

The active energy ray reactive group means a group in which a chemical bond is formed by an active species such as a radical generated by light or heat, preferably an unsaturated double bond, and an acrylic group (CH ₂ =). CH-group), methacryloyl group (CH = C (CH ₃ ) -group) or vinyl group (-CH = CH-group) is more preferable.

The (A) base binder polymer of the present invention is not particularly limited as long as it has the above characteristics, but for example, various epoxy resins such as bisphenol A type, bisphenol F type, phenol volac type, and cresol novolac type are unsaturated. Acid-modified acrylic (methacryl) resin, hydroxyl group-containing acrylic (methacryl) resin and isocyanato compound modified with a group-containing monocarboxylic acid and then acid-modified with a saturated or unsaturated group-containing polybasic acid anhydride. Examples thereof include urethane-modified acrylic (methacryl) resin obtained by the reaction of the above, polyester-modified acrylic (methacryl) resin obtained by the reaction of a hydroxyl group-containing acrylic (methacryl) resin and a carboxyl group-containing compound, and the like.

Further, the base binder polymer containing at least one kind of active energy ray reactive group in the molecule belongs to the base binder polymer (a1) of the present invention even when the structure further contains at least one carboxyl group. The carboxyl group contained in the structure may be present in the side chain and the terminal, and the terminal carboxylic acid may be a dicarboxylic acid derived from the tetracarboxylic acid or a carboxylic acid esterified with alcohol or the like. It is preferable that the base binder polymer (a1) of the present invention contains a carboxyl group because the solubility of the base binder polymer (A) in a solvent is improved. The acid value of the base binder polymer (a1) is preferably less than 150 mgKOH / g, and more preferably 100 mgKOH / g or less. If it exceeds 150 mgKOH / g, the obtained insulating film may have a poor appearance, or the adhesion and chemical resistance may be insufficient.

(Base binder polymer (a2))
The base binder polymer (a2) of the present invention has one or more carboxyl groups in the molecule and one or more structures selected from ether bonds, ester bonds, carbonate bonds, urethane bonds, imide bonds, urea bonds and amic acid bonds. The compound is not particularly limited as long as it has, but it is preferably a compound that is soluble in an organic solvent formed by a polymerization reaction of two or more monomers, and has a molecular weight of 1,000 or more and 1,000. More preferably, it is a polymer of 000 or less. Further, it may have one or more partial structures selected from a bisphenol A structure, a bisphenol F structure, a biphenol structure, a biphenol novolak structure, a bisxylenol structure, a biphenyl novolak structure and a urethane structure. Further, the acid value of the base binder polymer (a2) is preferably 30 to 150 mgKOH / g, more preferably 40 to 130 mgKOH / g, and even more preferably 50 to 100 mgKOH / g. If the acid value is less than 30 mgKOH / g, the developability becomes insufficient and development residue tends to be generated. If the acid value exceeds 150 mgKOH / g, the obtained insulating film shows poor appearance, adhesion and resistance. The chemical properties may be insufficient.

Examples of the base binder polymer (a2) in the present invention include acid-modified epoxy resin, acrylic resin and urethane resin having a carboxylic acid in the side chain, polyamic acid resin, urethane resin and imide resin having a terminal carboxylic acid, and the like. Be done.

The ratio of the component (a1) and the component (a2) in the present invention may be arbitrarily set in the range of (a1) :( a2) = 10: 90 to 90:10 in terms of solid content, but more preferably ( The range of a1): (a2) = 30: 70 to 70:30 is preferable in that the photosensitivity and the adhesion to the polyimide are improved.

When the amount of the component (a1) is more than the above range, that is, the amount of the component (a2) is less than the above range, the alkali resistance of the insulating film may be lowered and the contrast at the time of exposure / development may be difficult to be obtained. Further, when the component (a1) is less than the above range, that is, the component (a2) is more than the above range, the crosslink density may become too high and the insulating film may be brittle and easily cracked. Within the above range, the resolution at the time of exposure / development can be set to the optimum range.

[(B) Composition for modifying insulating film]
The composition for modifying the insulating film (B) in the present invention contains two or more types of particles having different volume average particle diameters. (B) is preferably at least one organic polymer particle selected from core-shell polymer particles, organic-inorganic composite particles, organic particles and crosslinked polymer particles, and the composition for modifying the insulating film (B) is More preferably, it contains organic polymer particles and a dispersion solvent and / or a compound that can be a dispersion medium, and 70% or more of the organic polymer particle components are dispersed in the state of primary particles.

Further, it is preferable that the two or more kinds of composition compounds having different volume average particle diameters include organic polymer particles (b1) having a volume average particle diameter of less than 1 μm and organic polymer particles (b2) having a volume average particle diameter of 1 μm or more. By controlling the volume average particle size within the above range, the flexibility and chemical resistance of the insulating film are excellent, which is preferable. When the volume average particle diameter is smaller than 0.001 μm (= 1 nm), unevenness is not effectively formed on the insulating film surface, and the tack-free property may be inferior, and the volume average particle diameter is 0.001 μm or more. Is preferable. If the average particle size exceeds 20 μm, the breakage resistance may be lowered, or the particles may be exposed at the openings at the time of forming a fine pattern, resulting in poor resolution (patterning property). From the viewpoint of photosensitivity, it is preferable to exclude the volume average particle diameter corresponding to the exposure wavelength of the excimer used, for example, 436 nm (g line), 405 nm (h line), 365 nm (i line), 248 nm. (KrF excimer laser), 193 nm (ArF excimer laser), 157 nm _{(F 2} excimer laser) and the like.

Further, the volume average particle diameter of (b1) is preferably 500 nm or less in terms of filling property, and more preferably 350 nm or less. This makes it possible to promote the photocuring reaction during exposure. The volume average particle diameter of (b2) is preferably 1 μm to 20 μm in terms of improving the patterning property of the photosensitive resin composition, and more preferably 1 μm to 10 μm to carry the organic polymer particles in the process. It is possible to improve the detachability of the polymer, the embedding property of fine particles, the covering property of the circuit end, and the insulation reliability.

Further, 70% or more of the organic polymer particle components of at least one of (b1) and (b2) are dispersed in the state of primary particles, so that the organic polymer particles are uniformly dispersed in the cured film. It is preferable from the viewpoint of being able to improve various properties such as low warpage, heat resistance and chemical resistance.

The core-shell polymer is a core-shell polymer having at least one rubber-like elastic layer, and is composed of a rubber particle core made of a polymer containing a polymer having rubber elasticity as a main component and a polymer component graft-polymerized thereto. It is preferably a polymer composed of a shell layer.

The polymer constituting the rubber particle core is crosslinked and can swell in a good solvent of the polymer, but is substantially insoluble and insoluble in a dispersion medium (for example, a curable resin such as an epoxy resin). Is preferable. The gel content of the core portion is preferably 60% by mass or more, more preferably 80% by mass or more, particularly preferably 90% by mass or more, and most preferably 95% by mass or more. Since the polymer constituting the core portion preferably has rubber properties, the glass transition temperature (Tg) is preferably 0 ° C. or lower, and more preferably −10 ° C. or lower.

The polymer constituting the rubber particle core is preferably a diene-based rubber, an acrylic-based rubber, or a polysiloxane rubber, or a combination thereof. The diene-based rubber and / or acrylic-based rubber is at least one or more monomers 50 selected from the group consisting of diene-based monomers (conjugated diene-based monomers) and (meth) acrylic acid ester-based monomers. It is preferably a rubber elastic body composed of 0% by mass or more and 100% by mass or less, and 0% by mass or more and 50% by mass or less of other copolymerizable vinyl monomers. When the amount of the monomer is less than 50% by mass, the toughness tends to decrease. The monomer is more preferably 60% by mass or more, further preferably 65% by mass or more, further preferably 70% by mass or more, and more preferably 95% by mass or less or 90% by mass or less. The monomer (Y) is more preferably 5% by mass or more, further preferably 10% by mass or more, still more preferably 15% by mass or more, still more preferably 45% by mass or less, still more preferably 40% by mass or less. Is. In the present invention, (meth) acrylic means acrylic and / or methacrylic.

Examples of the conjugated diene-based monomer constituting the rubber elastic body include butadiene, isoprene, and chloroprene, but butadiene is particularly preferable. Examples of the (meth) acrylic acid ester-based monomer include butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and lauryl (meth) acrylate, but butyl acrylate and 2-ethylhexyl acrylate are particularly preferable. These can be used alone or in combination.

Further, the rubber elastic body may be a copolymer of a conjugated diene-based monomer or a (meth) acrylic acid ester-based monomer, or a vinyl monomer copolymerizable with these. The vinyl monomer copolymerizable with the conjugated diene-based monomer or the (meth) acrylic acid ester-based monomer is selected from the group consisting of aromatic vinyl-based monomers and vinyl cyanide-based monomers. A vinyl monomer can be exemplified. As the aromatic vinyl-based monomer, for example, styrene, α-methylstyrene, vinylnaphthalene and the like can be used, and as the vinyl cyanide-based monomer, for example, (meth) acrylonitrile or substituted (meth) acrylonitrile and the like can be used. It can be used. These can be used alone or in combination.

Further, as a component constituting the rubber elastic body, a polyfunctional monomer may be contained in order to adjust the degree of cross-linking. Examples of the polyfunctional monomer include divinylbenzene, butanediol di (meth) acrylate, triallyl (iso) cyanurate, allyl (meth) acrylate, diallyl itaconic acid, and diallyl phthalate. The amount of these used is, for example, 10% by mass or less, preferably 5% by mass or less, and more preferably 3% by mass or less with respect to the total mass of the core portion. When the amount of the polyfunctional monomer used exceeds 10% by mass, the toughness of the rubber particle core tends to decrease.

In addition, a chain transfer agent may be used to adjust the molecular weight and the degree of cross-linking of the polymer constituting the rubber elastic body. Specifically, an alkyl mercaptan having 5 to 20 carbon atoms can be exemplified. The amount of these used is preferably 5% by mass or less, more preferably 3% by mass or less, based on the total mass of the core portion. If the amount of the chain transfer agent used exceeds 5% by mass, the amount of the uncrosslinked component of the rubber particle core increases, and when the dispersion medium is a curable resin, heat resistance, viscosity and the like may be adversely affected.

Further, as the rubber particle core, it is also possible to use polysiloxane rubber in place of or in combination with the rubber elastic body. When a polysiloxane rubber is used as the rubber particle core, a polysiloxane rubber composed of an alkyl or aryl2-substituted silyloxy unit such as dimethylsilyloxy, methylphenylsilyloxy, or diphenylsilyloxy can be used. In addition, when using such a polysiloxane rubber, if necessary,
(I) A method in which a part of a polyfunctional alkoxysilane compound is used in combination during polymerization, or (ii) a reactive group such as a vinyl-reactive group or a mercapto group is introduced, and then a vinyl-polymerizable monomer or an organic substance is introduced. Crosslinking is performed by a method of adding a peroxide or the like to cause a radical reaction, or a method of adding a crosslinkable monomer such as a polyfunctional vinyl compound or a mercapto group-containing compound after the polymerization of (iii) polysiloxane rubber and polymerizing. It is preferable to introduce a structure.

The polymer constituting the shell layer is graft-polymerized to the polymer constituting the rubber particle core from the viewpoint of the affinity between the curable resin such as epoxy resin and the core shell polymer, and is substantially the polymer constituting the rubber particle core. It is preferable that it is combined with. It is desirable that 70% by mass or more, more preferably 80% by mass or more, and further preferably 90% by mass or more of the polymers constituting the shell layer are bonded to the rubber particle core.

Since the core-shell polymer is stably dispersed in the insulating film modifying composition in the state of primary particles, the shell layer may give an affinity for a dispersion medium, and the shell layer may be used as an organic solvent and a dispersion medium described later. On the other hand, those having swelling property, compatibility or affinity are preferable.

Further, the shell layer preferably has a reactivity with a dispersion medium such as an epoxy resin or a curing agent blended at the time of use, if necessary, whereby the dispersion medium such as an epoxy resin reacts with the curing agent. By having a function of chemically reacting with these to form a bond under curing conditions, it is possible to effectively suppress the reaggregation of core-shell polymers with each other and deterioration of the dispersed state under curing conditions.

The polymer constituting the shell layer is composed of (meth) acrylic acid ester-based monomer, aromatic vinyl-based monomer, vinyl cyanide-based monomer, unsaturated acid derivative, (meth) acrylamide derivative, and maleimide derivative. A (co) polymer obtained by copolymerizing one or more selected components is preferable. Further, when the chemical reactivity of the shell layer at the time of curing with a dispersion medium such as an epoxy resin is required, a (meth) acrylic acid ester-based monomer, an aromatic vinyl-based monomer, or a vinyl cyanide-based monomer is required. , An unsaturated acid derivative, a (meth) acrylamide derivative, or a maleimide derivative, as well as one or more monomers containing a functional group selected from an epoxy group, a carboxyl group, a hydroxyl group, and a carbon-carbon double bond. It is more preferable to use a copolymer obtained by polymerization. These functional groups may have reactivity with a dispersion medium such as an epoxy resin described later, a curing agent thereof, a curing catalyst, or the like.

Examples of the (meth) acrylic acid ester-based monomer include (meth) methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Acrylic acid alkyl ester can be mentioned. Examples of the aromatic vinyl-based monomer include styrene, α-methylstyrene, alkyl-substituted styrene, and halogen-substituted styrenes such as bromostyrene and chlorostyrene. Further, examples of the vinyl cyanide-based monomer include (meth) acrylonitrile and substituted (meth) acrylonitrile. Examples of the monomer containing a reactive functional group include 2-hydroxyethyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate as (meth) acrylic acid esters having a reactive side chain. Aminoethyl, glycidyl (meth) acrylate and the like; examples of the vinyl ether containing a reactive group include glycidyl vinyl ether and allyl vinyl ether. Examples of unsaturated carboxylic acid derivatives include (meth) acrylic acid, itaconic acid, crotonic acid, and maleic anhydride. Examples of the (meth) acrylamide derivative include (meth) acrylamide (including N-substituted products). Examples of maleimide derivatives include imide maleate (including N-substituted products).

In the present invention, for example, aromatic vinyl-based monomer (particularly styrene) 0 to 50% by mass (preferably 5 to 40% by mass) and vinyl cyanide-based monomer (particularly acrylonitrile) 0 to 50% by mass (preferably). 1 to 30% by mass, more preferably 10 to 25% by mass), (meth) acrylic acid ester-based monomer (particularly methyl methacrylate) 0 to 50% by mass (preferably 5 to 45% by mass), reactivity. A monomer for forming a shell layer (a total of 100) in which 0 to 50% by mass (preferably 5 to 30% by mass, more preferably 10 to 25% by mass) of a monomer containing a functional group having a functional group (particularly glycidyl methacrylate) is combined. It is preferable to use a shell layer which is a polymer (% by mass).

The rubber particle core / shell ratio (mass ratio) of the core-shell polymer is, for example, in the range of 40/60 to 95/5, preferably 60/40 to 90/10. When the core / shell ratio deviates from 40/60 and the core ratio decreases, the stress reduction effect tends to decrease. If the ratio deviates from 95/5 and the ratio of the shell decreases, agglomeration is likely to occur during handling in the present invention, which may cause a problem in operability and may not provide desired physical properties.

The production of the core-shell polymer is not particularly limited, and can be produced by a well-known method such as emulsion polymerization, suspension polymerization, or microsuspension polymerization. Of these, a production method by multi-stage emulsion polymerization is particularly preferable. Specific examples of the emulsifying (dispersing) agent in an aqueous medium include alkyl or aryl sulfonic acid such as dioctyl sulfosuccinic acid and dodecylbenzene sulfonic acid, alkyl or aryl ether sulfonic acid, and dodecyl sulfate. Alkyl or aryl sulphate, alkyl or aryl ether sulphate, alkyl or aryl substituted phosphoric acid, alkyl or aryl ether substituted phosphoric acid, N-alkyl or aryl sarcosic acid, oleic acid as represented by dodecyl zarcosic acid, etc. Alkali metal salts or ammonium salts of various acids such as alkyl or aryl carboxylic acids such as stearic acid, alkyl or aryl ether carboxylic acids, and nonionic emulsifiers or dispersants such as alkyl or aryl-substituted polyethylene glycols. , Polyvinyl alcohols, alkyl-substituted celluloses, polyvinylpyrrolidones, polyacrylic acid derivatives and other dispersants are exemplified. These can be used alone or in combination as appropriate.

Examples of the core-shell polymer include MX-136, MX-153, MX-154, MX-170, MX-217, MX-257, MX-416, MX-551, MX-960, and MX manufactured by Kaneka Corporation. -965 and the like.

The organic-inorganic composite particles of the present invention are not particularly limited as long as they are particles having an inorganic layer formed on the surface of organic particles or spherical particles having an organic layer or organic fine particles formed on the surface of inorganic fine particles, but are spherical or powder. It also includes shapes, fibrous, needle-shaped, and scaly-shaped.

The organic-inorganic composite particles of the present invention are not particularly limited, but for example, the organic component is an organic polymer and / or an elastomer, and for example, a polyester polymer, a polyurethane polymer, a polyester urethane polymer, or a polyamide polymer. , Polygonic polymer, polyesteramide polymer, polyesterimide polymer, acrylic polymer, cellulose polymer, polylactic polymer, phenoxy polymer, etc., and side chain functional groups such as hydroxyl group, carboxyl group and epoxy group. It may be contained. Among the above organic components, polyurethane polymers and elastomers are preferable from the viewpoint of affinity with the component (A). Examples of the inorganic component include molten silica, crystalline silica, silicon carbide, simple metal, metal oxides such as titanium oxide and alumina, and metal nitrogen compounds such as silicon nitride and boron nitride.

Examples of the organic-inorganic composite particles of the present invention include product names of Daimic Beads UCN-8070CM Clear, UCN-8150CM Clear, UCN-5070D Clear, UCN-5150D Clear, and Negami Kogyo Co., Ltd. manufactured by Dainichiseika Kogyo Co., Ltd. Product name made by the company Art Pearl C-100 transparent, C-200 transparent, C-300 transparent, C-300WA, C-400 transparent, C-400WA, C-600 transparent, C-800 transparent, C-800WA, P -400T, P-800T, U-600T, CF-600T, JB-400T, JB-800T, CE-400T, CE-800T, TK-900TR, TK-1000TR and the like can be mentioned.

Further, the surface of the organic-inorganic composite particles may be coated with a silane coupling agent, other organic compounds, or the like to perform surface modification such as making the particles hydrophilic or hydrophobic.
The organic particles of the present invention are not particularly limited as long as they are spherical polymers containing carbon, but elliptical particles are also included.

The organic particles of the present invention are not particularly limited. For example, as polymethylmethacrylate-based spherical organic beads, product names of Ganzpearl GM-0600, GM-0600W, and crosslinked polymethylmethacrylate-based ones manufactured by Ganz Kasei Co., Ltd. are used. As spherical organic beads, product names of Ganz Pearl GM-0801S, GM-0807S, GM-1001-S, GM-1007S, GM-1505S-S, GMX-0610, GMX-0810, GMP- 0800, GMDM-050M, GMDM-080M, GMDM-100M, GMDM-150M, Product names manufactured by Sekisui Kasei Kogyo Co., Ltd. Techpolymers MBX-5, MBX-8, MBX-12, crosslinked polybutyl methacrylate-based spherical organic As beads, product names of Ganz Pearl GB-05S, GB-08S, GB-10S, GB-15S manufactured by Ganz Kasei Co., Ltd., product names of Techpolymer BM30X-5, BM30X-8 manufactured by Sekisui Kasei Kogyo Co., Ltd., As the crosslinked acrylic spherical organic beads, the product name Gantz Pearl GMP-0820 manufactured by Gantz Kasei Co., Ltd., and as the acrylic polymer-based spherical organic beads, the product name Gantz Pearl GBM-55COS manufactured by Gantz Kasei Co., Ltd. As organic beads, product names of Ganz Pearl GS-0605 and GS-1105 manufactured by Ganz Kasei Co., Ltd., product names of Techpolymer SBX-6 and SBX-8 manufactured by Sekisui Kasei Kogyo Co., Ltd., and cross-linked polyacrylic acid ester-based organic beads. As beads, product name Techpolymer ABX-8, AF10X-8, AFX-15, ARX-15 manufactured by Sekisui Kasei Kogyo Co., Ltd., and as nylon-based spherical organic beads, product name Ganz Pearl manufactured by Ganz Kasei Co., Ltd. GPA-550, as silicone-based spherical organic beads, product names manufactured by Ganz Kasei Co., Ltd. Ganzpearl SI-020, SI-030, SI-045, and as crosslinked silicone-based spherical organic beads, products manufactured by Ganz Kasei Co., Ltd. Name Gantz Pearl SIG-070, cross-linked urethane-based spherical organic beads, product names manufactured by Dainichi Seika Kogyo Co., Ltd. Daimic beads UCN-8070CM clear, UCN-8150CM clear, UCN-5070D clear, UCN-5150D clear, Negami Product name Art Pearl C-100 transparent, C-200 transparent, C-300 transparent, C-300WA, C-400 transparent, C-400WA, C-600 transparent, C-800 transparent, C manufactured by Kogyo Co., Ltd. -800WA, P-400T, P-800T, U-600T, CF-600T, JB-400T, JB-600T, JB-800T, CE-400T, CE-800T, AK-200TR, AK-300TR, AK-400TR , AK-800TR, HI-400T, HI-400BK, HI-400W, MM-120T, MM-120TW, MM-101SW, HB-800BK, HB-400BK, CH-800R, CH-800BL, TK-600T, TK -800T, TK-900TR, TK-1000TR, C-600TH, RZ-600T, RY-600T, RT-600T, RX-600T, RW-600T, RV-600T, RU-600T, BP-835T, BP-870T , BP-892T and the like.

Among the above-mentioned spherical organic beads, the organic particles of the present invention include crosslinked spherical organic beads containing a urethane bond in the molecule to reduce the warp of the insulating film, improve the flexibility to withstand repeated bending, and to use polyimide. It is preferable for improving the adhesiveness of the material.

The crosslinked polymer particles of the present invention are those in which at least two or more kinds of monomers are polymerized and have at least one kind of chemical bond and crosslinked structure, and basically a spherical shape in which the polymerization reaction is completed. Alternatively, the particles are not particularly limited as long as they are elliptical particles, but for example, trade names such as Daimic Beads UCN-8070CM Clear, UCN-8150CM Clear, UCN-5070D Clear, UCN-5150D Clear, and Negami Kogyo manufactured by Dainichi Seika Kogyo Co., Ltd. Product name made by Art Pearl Co., Ltd. C-100 transparent, C-200 transparent, C-300 transparent, C-300WA, C-400 transparent, C-400WA, C-600 transparent, C-800 transparent, C-800WA, P-400T, P-800T, U-600T, CF-600T, JB-400T, JB-600T, JB-800T, CE-400T, CE-800T, AK-200TR, AK-300TR, AK-400TR, AK- 800TR, HI-400T, HI-400BK, HI-400W, MM-120T, MM-120TW, MM-101SW, HB-800BK, HB-400BK, CH-800R, CH-800BL, TK-600T, TK-800T, TK-900TR, TK-1000TR, C-600TH, RZ-600T, RY-600T, RT-600T, RX-600T, RW-600T, RV-600T, RU-600T, BP-835T, BP-870T, BP- 892T and the like can be mentioned.

The volume average particle diameter of the component (B) of the present invention is, for example, using Microtrack UPA (manufactured by Nikkiso Co., Ltd.) or LA-950V2 (manufactured by Horiba Seisakusho Co., Ltd.) with respect to the volume-based median diameter (integrated distribution value 50%). It can be measured as particle size).

As a method for mixing the component (B) insulating film modifying composition of the present invention,
(1) (B) The composition for modifying the insulating film is relatively sheared by a stirrer or the like by mixing a part or all of the raw materials for the photosensitive resin composition other than the composition for modifying the insulating film in advance. (B) A method of adding a composition for modifying an insulating film by mixing using a mixing method with low stress.
(2) When polymerizing the raw material polymer and / or oligomer of the photosensitive resin composition, the composition for modifying the insulating film (B) is added before or during the polymerization, and the raw material polymer and / or the oligomer are added to the photosensitive resin composition. / Or a method of adding (B) a composition for modifying an insulating film by obtaining a dissolved oligomer.
(3) (B) The composition for modifying the insulating film and some or all of the raw materials for the other photosensitive resin composition are mixed and mixed using mechanical stress such as shear stress of a three-roll or bead mill. Method of smelting or dispersing and (B) adding a composition for modifying an insulating film,
(4) Of the raw materials for the photosensitive resin composition, a solid at room temperature and / or a raw material having a relatively high viscosity is mixed with the composition for modifying the insulating film (B) to obtain a liquid material in which the raw material is uniformly dissolved. As a result, (B) a method of adding the insulating film modifying composition and the like can be mentioned.

The blending amount of the component (B) of the present invention is preferably 30 to 100 parts by weight, more preferably 40 to 80 parts by weight, based on 100 parts by weight of the total solid content of the components (A) to (F) and other components. By forming the portion, it becomes possible to effectively form irregularities on the surface of the obtained insulating film, excellent tack-free property, and filling and curing by the component (B) can be obtained, so that the warp of the insulating film is reduced and stress is obtained. The flexibility to withstand repeated bending is improved by improving the relaxation effect and fracture toughness. If the component (B) is less than 30 parts by weight, it may be inferior in tack-free property and flexibility that can withstand repeated bending, and if it is more than 100 parts by weight, it is flame-retardant or when applying a resin composition solution. The coatability deteriorates, and the appearance may be poor due to foaming of the coating film during coating and insufficient leveling.

[(C) Photopolymerization Initiator]
The (C) photopolymerization initiator in the present invention is a compound that is activated by energy or a combination of energies at a specific wavelength such as UV light, laser light and LED light to initiate and promote the reaction of a radically polymerizable group.

The component (C) of the present invention is not particularly limited as long as it is a compound having the above characteristics, but for example, Mihira's ketone, 4,4'-bis (diethylamino) benzophenone, 4,4', 4 "-tris. (Dimethylamino) Triphenylmethane, 2,2'-bis (2-chlorophenyl) -4,4', 5,5'-tetraphenyl-1,2'-diimidazole, acetophenone, benzoin, 2-methylbenzoin, Benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 2-t-butyl anthraquinone, 1,2-benzo-9,10-anthraquinone, methylanthraquinone, thioxanthone, 2, 4-diethylthioxanthone, 2-isopropylthioxanthone, 1-hydroxycyclohexylphenylketone, diacetylbenzyl, benzyldimethylketal, benzyldiethylketal, 2 (2'-frylethylidene) -4,6-bis (trichloromethyl) -S-triazine, 2 [2'(5''-methylfuryl) ethylidene] -4,6-bis (trichloromethyl) -S-triazine, 2 (p-methoxyphenyl) -4,6-bis (trichloromethyl) ) -S-triazine, 2,6-di (p-azidobenzal) -4-methylcyclohexanone, 4,4'-diazidocalcone, di (tetraalkylammonium) -4,4'-diazidostilben-2,2 '-Disulfoneate, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one , 1- [4- (2-Hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpho Renopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2) , 6-Dimethoxybenzoyl) -2,4,4-trimethyl-pentylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2-hydroxy-2-methyl-1-phenyl-propane-1 -Ketone, bis (n5-2,4-cyclopentadiene-1-yl) -bis (2, 6-Difluoro-3- (1H-pyrrole-1-yl) -phenyl) titanium, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], iodonium , (4-Methylphenyl) [4- (2-methylpropyl) phenyl] -hexafluorophosphate (1-), ethyl-4-dimethylaminobenzoate, 2-ethylhexyl-4-dimethylaminobenzoate, etanone, 1- [9-Ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxyom), 9H-thioxanthene-2-carboxyaldehyde 9-oxo-2-( O-acetyloxime) and the like. It is desirable to appropriately select the above component (B), and it is desirable to use a mixture of one or more.

The component (C) is preferably blended in an amount of 0.1 to 20% by weight, more preferably 0.2 to 10% by weight, in the photosensitive resin composition.

It is preferable to use the above blending ratio because the photosensitivity of the black resin composition is improved. When the amount of the component (C) is less than the above range, the reaction of the radically polymerizable group at the time of light irradiation is unlikely to occur, and the curing may be insufficient in many cases. Further, when the component (C) is more than the above range, it becomes difficult to adjust the light irradiation amount, and an overexposure state may occur. Therefore, in order to efficiently proceed with the photocuring reaction, it is preferable to adjust within the above range.

As the (C) photopolymerization initiator in the present invention, preferably 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1, 2-benzyl-2-dimethylamino-1-( 4-Morphorinophenyl) -butane-1-one, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, N, Α-Aminoacetophenone-based photopolymerization initiators such as N-dimethylaminoacetophenone, 1,2-octanedione, 1- [4- (phenylthio)-, 2- (O-benzoyloxime)], iodonium, (4) -Methylphenyl) [4- (2-methylpropyl) phenyl] -hexafluorophosphate (1-), ethyl-4-dimethylaminobenzoate, 2-ethylhexyl-4-dimethylaminobenzoate, etanone, 1- [9- Ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxyom), 9H-thioxanthene-2-carboxyaldehyde 9-oxo-2- (O-acetyl) Oxime ester-based photopolymerization initiator such as oxime), 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2-hydroxy-2-methyl-1-phenyl-propan-1-ketone, bis (n5-2) , 4-Cyclopentadiene-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole-1-yl) -phenyl) Titanosen-based photopolymerization initiators such as titanium can be mentioned.

More preferably, it contains an α-aminoacetophenone-based photopolymerization initiator. Examples of such α-aminoacetophenone-based photopolymerization initiators include 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1, 2-benzyl-2-dimethylamino-1-(. 4-Morphorinophenyl) -butane-1-one, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, N, Examples thereof include N-dimethylaminoacetophenone. Examples of commercially available products include Irgacure 907, Irgacure 369, and Irgacure 379 manufactured by BASF.

[(D) Solvent]
The solvent in the present invention may be any solvent that can dissolve the components of the photosensitive resin composition of the present invention. For example, sulfoxide-based solvents such as dimethyl sulfoxide and diethyl sulfoxide, methyl monoglime (1,2-dimethoxyethane), methyl diglime (bis (2-methoxyether) ether), and methyl triglime (1,2-bis (2)). -Methoxyethoxy) ethane), methyl tetraglime (bis [2- (2-methoxyethoxyethyl)] ether), ethyl monoglime (1,2-diethoxyethane), ethyl diglime (bis (2-ethoxyethyl)) (Ether), symmetric glycol diethers such as butyl diglime (bis (2-butoxyethyl) ether), γ-butylolactone, methyl acetate, ethyl acetate, isopropyl acetate, n-propyl acetate, butyl acetate, propylene glycol monomethyl ether acetate. , Ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate (also known as carbitol acetate, acetate 2- (2-butoxyethoxy) ethyl)), diethylene glycol monobutyl ether acetate, 3-methoxybutyl acetate, ethylene glycol monomethyl ether acetate, ethylene Acetates such as glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, propylene glycol diacetate, 1,3-butylene glycol diacetate, dipropylene glycol methyl ether, tripropylene glycol methyl ether, propylene glycol n-propyl ether. , Dipropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripylene glycol n-propyl ether, propylene glycol phenyl ether, dipropylene glycol dimethyl ether, 1,3-dioxolane, ethylene glycol monobutyl ether , Diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethylene glycol monoethyl ether and other ethers can be mentioned, and these can be used alone or in combination of two or more.

The amount of the solvent in the present invention is preferably 10 to 400 parts by weight with respect to 100 parts by weight of the total solid content of the components (A) to (F) and other components in the photosensitive resin composition. More preferably, it is 20 to 200 parts by weight, and particularly preferably 40 to 100 parts by weight. By adjusting the amount of the solvent within the above range, the viscosity and viscosity of the resin composition can be adjusted within an appropriate range for coating such as screen printing, which is preferable. When the amount of the solvent is less than the above range, the viscosity of the resin composition becomes very high, the coating becomes difficult, and the foam entrainment and leveling property at the time of coating may be inferior. Further, when the amount of the solvent is more than the above range, the viscosity of the resin composition becomes very low, the coating becomes difficult, and the coating property of the circuit may be inferior.

[(E) Colorant]
The photosensitive resin composition of the present invention can contain (E) a colorant.
The colorant (E) is not particularly limited as long as it is either a dye or a pigment and can color the photosensitive resin composition of the present invention. Moreover, you may combine a plurality of colorants. Specifically, a red colorant, an orange colorant, a yellow colorant, a green colorant, a blue colorant, a purple colorant, a black colorant, and a white colorant can be arbitrarily combined. A specific example is shown below by the color index number.

(Red colorant)
The red colorant of the present invention is not particularly limited, and for example, monoazo type, dizuazo type, azolake type, benzimidazolone type, perylene type, diketopyrrolopyrrole type, condensed azo type, anthraquinone type, quinacridone type and the like. C.I. I. Pigment Red 122, 149, 166, 177, 179, 242, 224, 254, 264, 272.

(Orange colorant)
The orange colorant of the present invention is not particularly limited, but for example, C.I. I. Pigment Orange 5, 13, 14, 16, 17, 24, 34, 36, 38, 40, 43, 46, 49, 51, 55, 59, 61, 63, 64, 71, 73.

(Yellow colorant)
The yellow colorant of the present invention is not particularly limited, and is, for example, a pigment such as monoazo, disazo, condensed azo, benzimidazolone, isoindolinone, and anthraquinone. I. Pigment Yellow 83, 110, 128, 138, 139, 150, 151, 154, 155, 180, 181.

(Green colorant)
The green colorant of the present invention is not particularly limited, and is, for example, a phthalocyanine-based, anthraquinone-based, perylene-based pigment, or the like. I. Pigment Green 7, 37, and Solvent Green 3, 5, 20, 28, which are dye-based, can be mentioned. In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds can also be used. In particular, a copper phthalocyanine type is preferable from the viewpoint of coloring power.

(Blue colorant)
The blue colorant of the present invention is not particularly limited, but is, for example, a phthalocyanine-based, anthraquinone-based, dioxazine-based pigment, or the like. I. Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 60, Dye-based Solvent Blue 35, 63, 68, 70, 83, 87, 94, 97, 122, 136, 67, 70 can be mentioned. In addition to the above, metal-substituted or unsubstituted phthalocyanine compounds can also be used. In particular, a copper phthalocyanine type is preferable from the viewpoint of coloring power.

(Purple colorant)
The purple colorant of the present invention is not particularly limited, but for example, C.I. I. Pigment Violet 19, 23, 29, 30, 32, 36, 37, 38, 39, 40, 50, Solvent Violet 13, 36.

(Black colorant)
The black colorant of the present invention is not particularly limited, but is, for example, a pigment such as carbon black, graphite, metal oxide, titanium black, anthraquinone, etc. C. i. Pigment Black 6, 7, 8 , 9, 10, 11, 12, 13, 15, 25, 28, 29, 30, 31, 32.

(White colorant)
The white colorant of the present invention is not particularly limited, and examples thereof include Zi. Pigment Whites 4, 6 and 7, which are zinc oxide-based, titanium oxide-based, and zinc sulfide-based pigments.

[(F) Filler containing phosphorus element]
The photosensitive resin composition of the present invention can contain a filler containing the element (F) phosphorus. (F) The filler containing a phosphorus element is a compound containing a phosphorus element in a molecule and having a glass transition temperature of room temperature or higher, and is not particularly limited as long as the particles have a deposition average particle size of 1 to 10 μm. Examples of the shape include spherical, powdery, fibrous, needle-like, and scaly-like. In particular, phosphinate is preferable, and it is a compound represented by the following general formula (1).

(In the formula, R1 and R2 represent independently linear or branched alkyl or aryl groups having 1 to 6 carbon atoms, respectively, and M is Mg, Ca, Al, Sb, Sn, Ge, Ti, Fe. , Zr, Zn, Ce, Bi, Sr, Mn, Li, Na and K, indicating metals selected from at least one of the group, where t is an integer of 1 to 4).

The phosphinate of the present invention is not particularly limited as long as it has the above structure, but for example, aluminum trisdiethylphosphinate, aluminum trismethylethylphosphinate, aluminum trisdiphenylphosphinate, zinc bisdiethylphosphinate, and bismethylethylphosphine. Examples thereof include zinc acid, zinc bisdiphenylphosphinate, titanyl bisdiethylphosphinate, titanyl bismethylethylphosphinate, titanyl bisdiphenylphosphinate, and the like, and these can be used alone or in combination of two or more. It is preferable that the phosphinate compound of the present invention further contains an aluminum element from the viewpoint of obtaining high flame retardancy, and in particular, aluminum trisdiethylphosphinate and aluminum trismethylethylphosphinate containing an aluminum element are used. If so, it is preferable because higher flame retardancy can be obtained.

The content of the component (F) of the present invention is preferably 15 to 80 parts by weight, more preferably 20 to 75 parts by weight, based on 100 parts by weight of the total solid content of the components (A) to (F) and other components. By using the weight part, the obtained insulating film has excellent flame retardancy and electrical insulation reliability. In particular, from the viewpoint of flame retardancy, the content ratio of the phosphorus element to the solid content of the photosensitive resin composition is preferably 3% by weight or more. If the component (F) is less than 15 parts by weight, the flame retardancy may be inferior, and if it is more than 80 parts by weight, the coatability at the time of coating the resin composition solution deteriorates, and the coating at the time of coating is deteriorated. Poor appearance may occur due to foaming of the film or insufficient leveling.

[Other ingredients]
The photosensitive resin composition of the present invention may contain additives such as a radical polymerizable compound, a thermosetting resin, an inorganic filler, a flame retardant, a adhesion imparting agent and a polymerization inhibitor, if necessary.

[Radical polymerizable compound]
The radically polymerizable compound used in the present invention is a compound in which a chemical bond is formed by radicals generated by light or heat. Among them, it is a compound in which a chemical bond is formed by a photopolymerization initiator, and a compound having at least one unsaturated double bond in the molecule is preferable. Furthermore, the unsaturated double bond, acrylic group (CH2 = CH- group), methacryloyl group _{(CH = C (CH 3)} - group) that is or vinyl group (-CH = CH- group) preferable.

Examples of such radically polymerizable compounds include bisphenol F EO modified (n = 2 to 50) diacrylate, bisphenol A EO modified (n = 2 to 50) diacrylate, and bisphenol S EO modified (n = 2 to 50) diacrylate. , Bisphenol F EO modified (n = 2-50) dimethacrylate, bisphenol A EO modified (n = 2-50) dimethacrylate, bisphenol S EO modified (n = 2-50) dimethacrylate, 1,6-hexanediol di Acrylate, Neopentyl glycol diacrylate, Ethylene glycol diacrylate, Pentaerythritol diacrylate, Trimethylol propantriacrylate, Pentaerythritol triacrylate, Dipentaerythritol hexaacrylate, Tetramethylol propantetraacrylate, Tetraethylene glycol diacrylate, 1,6 -Hexanediol dimethacrylate, neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate, pentaerythritol dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexamethacrylate, tetramethylolpropanetetramethacrylate, tetraethyleneglycoldimethacrylate. , Methoxydiethylene glycol methacrylate, methoxypolyethylene glycol methacrylate, β-methacryloyloxyethyl hydrogen phthalate, β-methacryloyloxyethyl hydrogen succinate, 3-chloro-2-hydroxypropyl methacrylate, stearyl methacrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, Phenoxypolyethylene glycol acrylate, β-acryloyloxyethyl hydrogen succinate, lauryl acrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,6 -Hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2-hydroxy-1,3-dimethacryloxypropane, 2,2-bis [4-( Methacryloxyethoxy) phenyl] propane, 2,2-bis [4- (methacryloxy-diethoxy) phenyl] propane, 2,2-bis [4- (methacryloxy-polyethoxy) phenyl] propane, polyethylene glycol diacrylate, tripropylene glycol Diacrylate, polypropylene glycol diacrylate, 2,2-bis [4- (acryloxy-diethoxy) phenyl] propane, 2,2-bis [4- (acryloxy-polyethoxy) phenyl] propane, 2-hydroxy-1-acryloxy- 3-Methacryloxypropane, trimethylolpropane trimethacrylate, tetramethylolmethanetriacrylate, tetramethylolmethanetetraacrylate, methoxydipropylene glycol methacrylate, methoxytriethylene glycol acrylate, nonylphenoxypolyethylene glycol acrylate, nonylphenoxypolypropylene glycol acrylate, 1- Acryloyloxypropyl-2-phthalate, isostearyl acrylate, polyoxyethylene alkyl ether acrylate, nonylphenoxyethylene glycol acrylate, polypropylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 3-methyl-1,5-pentanedioldi Methacrylate, 1,6-mexanediol dimethacrylate, 1,9-nonanediol methacrylate, 2,4-diethyl-1,5-pentanediol dimethacrylate, 1,4-cyclohexanedimethanol dimethacrylate, dipropylene glycol diacrylate , Tricyclodecanedimethanol diacrylate, 2,2-hydrogenated bis [4- (acryloxy polyethoxy) phenyl] propane, 2,2-bis [4- (acryloxy polypropoxy) phenyl] propane, 2,4- Diethyl-1,5-pentanediol diacrylate, ethoxylated totimethylol propantriacrylate, propoxylated totimethylol propantriacrylate, tri-isocyanurate (ethane acrylate), pentathritol tetraacrylate, ethoxylated pentathritol tetraacrylate, propoxy Pentathritol Tetraacrylate, Ditrimethylol Propane Tetraacrylate, Dipentaerythritol Polyacrylate, Triallyl Isocyanurate, Glycidyl Meta Cryrate, glycidyl allyl ether, 1,3,5-triacrylloylhexahydro-s-triazine, triallyl 1,3,5-benzenecarboxylate, triallylamine, triallylcitrate, triallyl phosphate, alloverbital, diallylamine, diallyl Dimethylsilane, diallyl disulfide, diallyl ether, zarylsiallate, diallyl isophthalate, diallyl terephthalate, 1,3-dialyloxy-2-propanol, diallyl sulfide diallyl maleate, 4,4'-isopropyridene diphenol dimethacrylate, 4, 4'-isopropyridene diphenol diacrylate, etc. are preferred, but not limited to these. In particular, the repeating unit of EO (ethylene oxide) contained in one molecule of diacrylate or methacrylate is preferably in the range of 2 to 50, and more preferably 2 to 40. By using a resin composition having a repeating unit in the range of 2 to 50, the solubility of the resin composition in an aqueous developing solution typified by an alkaline aqueous solution is improved, and the developing time is shortened. Further, stress does not easily remain in the cured insulating film of the photosensitive thermosetting resin composition. For example, among printed wiring boards, when laminated on a flexible printed wiring board using a polyimide resin as a base material, the printed wiring board It has features such as being able to suppress curling.

In particular, it is particularly preferable to use the above-mentioned EO-modified diacrylate or dimethacrylate in combination with an acrylic resin having 3 or more acrylic groups or methacrylic groups in order to improve developability. For example, ethoxylated isocyanuric acid EO-modified triacrylate. Ethoxylated isocyanuric acid EO-modified trimethacrylate, ethoxylated trimethylol propanetriacrylate, ethoxylated trimethylolpropan triacrylate, ethoxylated trimethylol propanetriacrylate, trimethylol propanetriacrylate, propoxylated trimethylol propanetriacrylate, pentaerythritol triacrylate Acrylate, pentaerythritol tetraacrylate ethoxylated, pentaerythritol tetraacrylate ethoxylated, ditrimethylolpropanetetraacrylate, ditrimethylolpropanetetraacrylate, propoxylated pentaeristol tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, 2,2 , 2-Trisacryloyloxymethylethyl succinic acid, 2,2,2-Trisacryloyloxymethylethylphthalic acid, propoxylated ditrimethylol propanetetraacrylate, propoxylated dipentaerythritol hexaacrylate, ethoxylated isocyanuric acid triacrylate, ε-caprolactone-modified tris- (2-acryloxyethyl) isocyanurate, caprolactone-modified ditrimethylol propanetetraacrylate, the following general formula (2)

(In the formula, a + b = 6, n = 12), the compound represented by the following general formula (3).

(In the formula, a + b = 4, n = 4), the compound represented by the following formula (4).

Compound represented by, the following general formula (5)

(In the formula, m = 1, a = 2, b = 4 or m = 1, a = 3, b = 3 or m = 1, a = 6, b = 0 or m = 2, a = 6 , B = 0), the following general formula (6)

(In the formula, a + b + c = 3.6), the compound represented by the following formula (7).

Compound represented by, the following general formula (8)

Acrylic resins such as compounds represented by (in the formula, m · a = 3, a + b = 3, where “m · a” is the product of m and a) are preferably used.

Further, a hydroxyl group and a carbonyl in the molecular structure of 2-hydroxy-3-phenoxypropyl acrylate, monohydroxyethyl phthalate acrylate, ω-carboxy-polycaprolactone monoacrylate, acrylic acid dimer, pentaeslitortri and tetraacrylate. Those having a group are also preferably used.

In addition, any radical polymerizable compound such as an epoxy-modified acrylic (methacrylic) resin, a urethane-modified acrylic (methacrylic) resin, or a polyester-modified acrylic (methacrylic) resin may be used.

Although it is possible to use one type of radically polymerizable compound, it is preferable to use two or more types in combination in order to improve the heat resistance of the insulating film after photocuring.

It is photosensitive that the radically polymerizable compound in the present invention is blended so as to be 10 to 200 parts by weight with respect to 100 parts by weight of the total solid content of the components (A) to (F) and other components. It is preferable in that the photosensitivity of the sex resin composition is improved.

If the amount of the radically polymerizable compound is less than the above range, the alkali resistance of the insulating film may be lowered, and it may be difficult to obtain contrast when exposed and developed. Further, when the amount of the radically polymerizable resin is more than the above range, the stickiness of the coating film obtained by applying the photosensitive resin composition on the substrate and drying the solvent becomes large, so that the productivity is lowered. In addition, the insulating film may be brittle and easily cracked due to the excessively high crosslink density. Within the above range, the resolution at the time of exposure / development can be set to the optimum range.

[Thermosetting resin]
The thermosetting resin used in the present invention is a compound that forms a crosslinked structure by heating and functions as a thermosetting agent. For example, thermosetting resins such as epoxy resin, bismaleimide resin, bisallyl nadiimide resin, acrylic resin, methacrylic resin, hydrosilyl curing resin, allyl curing resin, unsaturated polyester resin; allyl on the side chain or terminal of the polymer chain. A side chain reactive group type thermosetting polymer having a reactive group such as a group, a vinyl group, an alkoxysilyl group, or a hydrosilyl group can be used. These can be used alone or in combination of two or more.

Among these, as the thermosetting resin in the present invention, it is preferable to use an epoxy resin. The epoxy resin in the present invention contains all of monomers, oligomers, polymers, etc. regardless of the molecular weight as long as it has at least one epoxy group in the molecule, forms a crosslinked structure by heating, and is thermosetting. It is a compound that functions as an agent. By containing the epoxy resin, heat resistance can be imparted to the insulating film obtained by curing the resin composition, and adhesiveness to a conductor such as a metal foil or a circuit board can be imparted. The epoxy resin is a compound containing at least two epoxy groups in the molecule. For example, as a bisphenol A type epoxy resin, product names jER828, jER1001, jER1002 manufactured by Japan Epoxy Resin Co., Ltd., and ADEKA Co., Ltd. Product Names Adecaredin EP-4100E, Adecaledin EP-4300E, Product Names RE-310S, RE-410S manufactured by Nippon Kayaku Co., Ltd., Product Names Epicron 840S, Epicron 850S, Epicron 1050, Epicron 7050 manufactured by Dainippon Ink Co., Ltd. , Product names made by Toto Kasei Co., Ltd. Epototo YD-115, Epototo YD-127, Epototo YD-128, As bisphenol F type epoxy resins, product names jER806, jER807 made by Japan Epoxy Resin Co., Ltd., made by ADEKA Co., Ltd. Product name Adecaredin EP-4901E, Adecaredin EP-4930, Adecaledin EP-4950, Product name made by Nippon Kayaku Co., Ltd. Product names RE-303S, RE-304S, RE-403S, RE-404S, Product name made by DIC Co., Ltd. Epoxy 830, Epicron 835, Product name Epototo YDF-170 manufactured by Toto Kasei Co., Ltd., Epototo YDF-175S, Epototo YDF-2001, Bisphenol S type epoxy resin, product name Epicron EXA-1514 manufactured by DIC Co., Ltd. As the bisphenol A type epoxy resin, the product name jERYX8000, jERYX8034, jERYL7170 manufactured by Japan Epoxy Resin Co., Ltd., the product name Adecalegin EP-4080E manufactured by ADEKA Co., Ltd., the product name Epicron EXA-7015 manufactured by DIC Co., Ltd., Toto Kasei Co., Ltd. Company-made product names Epototo YD-3000, Epototo YD-4000D, as biphenyl type epoxy resins, product names jERYX4000, jERYL6121H, jERYL6640, jERYL6677 manufactured by Japan Epoxy Resin Co., Ltd., product name NC- made by Nippon Kayaku Co., Ltd. 3000, NC-3000H, as phenoxy type epoxy resin, product names jER1256, jER4250, jER4275 made by Japan Epoxy Resin Co., Ltd., and as naphthalene type epoxy resin, product names Epicron HP-4032, Epicron HP- made by DIC Co., Ltd. 4700, Epoxy HP-4200, Product name NC-7000L manufactured by Nippon Kayaku Co., Ltd., Phenolno As the volac type epoxy resin, the product names jER152 and jER154 manufactured by Japan Epoxy Resin Co., Ltd., the product names EPPN-201-L manufactured by Nippon Kayaku Co., Ltd., and the product names Epicron N-740 and Epicron N- of DIC Co., Ltd. 770, Toto Kasei Co., Ltd. product name Epototo YDPN-638, as cresol novolac type epoxy resin, Nippon Kayaku Co., Ltd. product names EOCN-1020, EOCN-102S, EOCN-103S, EOCN-104S, DIC stock The company's product names Epicron N-660, Epicron N-670, Epicron N-680, Epicron N-695, and Trisphenol methane type epoxy resins are the product names EPPN-501H and EPPN-501HY manufactured by Nippon Kayaku Co., Ltd. , EPPN-502H, as a dicyclopentadiene type epoxy resin, product name XD-1000 manufactured by Nippon Kayaku Co., Ltd., product name Epicron HP-7200 manufactured by DIC Co., Ltd., and as an amine type epoxy resin, Toto Kasei Co., Ltd. Epototo YH-434, Epototo YH-434L, as flexible epoxy resin, product names jER871, jER872, jERYL7175, jERYL7217 manufactured by Japan Epoxy Resin Co., Ltd., product names Epicron EXA-4850 manufactured by DIC Co., Ltd. As the urethane-modified epoxy resin, the product name of ADEKA Co., Ltd. is Adecaredin EPU-6, Adecaredin EPU-73, Adecaredin EPU-78-11, and as the rubber-modified epoxy resin, the product name of ADEKA Co., Ltd. Examples of Adecaredin EPR-4026, Adecaledin EPR-1309, and chelate-modified epoxy resins include Adecaledin EP-49-10 and Adecaledin EP-49-20 manufactured by ADEKA Co., Ltd. The above can be used alone or in combination of two or more.

The curing agent for the epoxy resin in the present invention is not particularly limited, and examples thereof include phenolic resins such as phenol novolac resin, cresol novolac resin, and naphthalene-type phenol resin, amino resins, urea resins, melamine, and dicyandiamide. It can be used alone or in combination of two or more.

The curing accelerator is not particularly limited, but for example, a phosphine compound such as triphenylphosphine; an amine compound such as a tertiary amine, a trimethanolamine, a triethanolamine, or a tetraethanolamine; 1,8- Borate compounds such as diaza-bicyclo [5,4,0] -7-undecenium tetraphenylborate, imidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-un Imidazoles such as decylimidazole, 1-benzyl-2-methylimidazole, 2-heptadecylimidazole, 2-isopropylimidazole, 2,4-dimethylimidazole, 2-phenyl-4-methylimidazole; 2-methylimidazoline, 2- Imidazolines such as ethyl imidazoline, 2-isopropyl imidazoline, 2-phenyl imidazoline, 2-undecyl imidazoline, 2,4-dimethyl imidazoline, 2-phenyl-4-methyl imidazoline; 2,4-diamino-6- [2' -Methylimidazolyl- (1')]-ethyl-s-triazine, 2,4-diamino-6- [2'-undecylimidazolyl- (1')]-ethyl-s-triazine, 2,4-diamino- Examples thereof include azine-based imidazoles such as 6- [2'-ethyl-4'-methylimidazolyl- (1')] -ethyl-s-triazine, which can be used alone or in combination of two or more.

The thermosetting resin component in the present invention is preferably 0.5 to 100 parts by weight, more preferably 1 to 100 parts by weight, based on 100 parts by weight of the total solid content of the components (A) to (F) and other components. It is 50 parts by weight, particularly preferably 5 to 20 parts by weight. By adjusting the amount of the thermosetting resin component within the above range, the heat resistance, chemical resistance, and electrical insulation reliability of the insulating film obtained by curing the photosensitive resin composition can be improved. preferable.

When the amount of the thermosetting resin component is less than the above range, the heat resistance and electrical insulation reliability of the insulating film obtained by curing the photosensitive resin composition may be inferior. Further, when the amount of the thermosetting resin component is more than the above range, the insulating film obtained by curing the photosensitive resin composition becomes brittle and inferior in flexibility, and the warp of the insulating film may be large.

[Flame retardants]
The flame retardant used in the present invention is a compound used to make a photosensitive resin composition flame-retardant. For example, a phosphoric acid ester compound, a halogen-containing compound, a metal hydroxide, an organic phosphorus compound, a silicone compound, or the like can be used, and as a method of use, it can be used as an additive flame retardant or a reactive flame retardant. .. Further, the flame retardant may be used alone or in combination of two or more as appropriate. Among these, as the flame retardant, it is more preferable to use a non-halogen compound from the viewpoint of environmental pollution, and a phosphorus flame retardant is particularly preferable. In the photosensitive resin composition of the present invention, it is preferable that the components (A) to (F) and other components are blended in an amount of 1 to 100 parts by weight with respect to 100 parts by weight in total. .. In particular, when a phosphorus-based flame retardant is added, the content ratio of the phosphorus element to the solid content of the photosensitive resin composition is preferably 3% by weight or more. It is preferable to use the above blending ratio because the flame retardancy is improved without impairing the developability, photosensitivity, and breakage resistance of the obtained cured film of the photosensitive resin composition. If the amount of the flame retardant component is less than the above range, the flame retardancy of the cured film of the photosensitive resin composition may be insufficient. Further, when the flame retardant component is more than the above range, the developability and the photosensitive property of the photosensitive resin composition may be lowered.

[Inorganic filler]
The inorganic filler used in the present invention is not particularly limited, and examples thereof include spherical, powdery, fibrous, needle-like, and scaly shapes. Examples of the inorganic filler include silica, metal oxides such as titanium oxide and alumina, metal nitrogen compounds such as silicon nitride and boron nitride, and metal salts such as calcium carbonate, calcium hydrogen phosphate, calcium phosphate and aluminum phosphate. These can be used alone or in combination of two or more. In particular, when it is a metal oxide, a metal nitrogen compound, or a metal salt, it has a high affinity with oxygen atoms, hydroxyl groups, adsorbed water, etc., which are defects on the copper surface, and can improve the adhesion with the insulating film / copper. Therefore, it is preferable.

Further, the surface of the filler may be coated with a silane coupling agent, another organic compound or the like to perform surface modification such as making it hydrophilic or hydrophobic. These can be used alone or in combination of two or more.

How to add the filler
1. 1. Method of adding to the polymerization reaction solution before or during the polymerization 2. Method of kneading using 3 rolls or the like after the polymerization is completed. Any method may be used, such as preparing a dispersion containing a filler and mixing it with the resin composition solution. It is desirable to appropriately select the above filler, and one or more of them can be mixed and used. Further, in order to disperse the filler well and stabilize the dispersed state, a dispersant, a thickener or the like can be used within a range that does not affect the physical properties of the film.

[Adhesion imparting agent and polymerization inhibitor]
Examples of the adhesion-imparting agent include a silane coupling agent, a triazole-based compound, a tetrazole-based compound, and a triazine-based compound, and examples of the polymerization inhibitor include hydroquinone and hydroquinone monomethyl ether, which are used alone or in combination of two or more. Can be used.

[Manufacturing method of photosensitive resin composition]
The photosensitive resin composition of the present invention can be obtained by pulverizing and dispersing the components (A) to (F) and other components and mixing them. The crushing / dispersing method is not particularly limited, but is carried out using, for example, a general kneading device such as a bead mill, a ball mill, or a three-roll. The particle size of the particles contained in the photosensitive resin composition can be measured by a method using a gauge specified in JIS K 5600-2-5. Further, if a particle size distribution measuring device is used, the average particle size, the particle size, and the particle size distribution can be measured.

[Polyimide with insulating film]
The polyimide with an insulating film of the present invention has an insulating film obtained by curing a photosensitive resin composition having a thickness of 5 to 50 μm on the polyimide, and is obtained by curing the photosensitive resin composition. It is not particularly limited as long as it is provided. Here, curing means that a thermosetting step is always performed, and it is not always necessary to perform a drying, exposure, and developing step.

The polyimide of the present invention is not particularly limited as long as it has an imide skeleton obtained by reacting an acid anhydride with diamine, but for example, aromatic diamine and aromatic tetra. Condensation polymer with carboxylic acid, bismaleimide resin which is an addition polymer of aromatic diamine and bismaleimide, polyaminobismaleimide resin which is an addition polymer of aminobenzoic acid hydrazide and bismaleimide, disianate compound and bismaleimide resin Examples thereof include heat-curable polyimides such as bismaleiimide triazine resin composed of the above, and more specifically, polyimide films manufactured by Kaneka Co., Ltd., Apical 12.5AH, Apical 25NPI, Apical 25NPI, Apical 50NPI, PIXEO BP, PIXEO BP-S, Toray Dupont Polyimide Film, Capton 40EN, Capton 50EN, 80EN, 100EN, 150EN, 200EN, Capton H, Capton V, Capton EN-S, Ube Kosan Co., Ltd. Polyimide Film, Upirex 12.5S, Upylex 7.5S, Upylex 12.5CA, Upylex 8CA, Upylex VT, Polyimide manufactured by Timerid Technology, TH-012, TH-025, TH-050, TH-075, TL-012 and the like.

[Flexible printed wiring board with insulating film]
The flexible printed wiring board with an insulating film of the present invention is an insulating film obtained by curing a photosensitive resin composition with a thickness of 5 to 50 μm on a flexible printed wiring board (circuit) similar to the above-mentioned polyimide with an insulating film. It is not particularly limited as long as it has, and is obtained by curing the photosensitive resin composition. Here, curing means that a thermosetting step is always performed, and it is not always necessary to perform a drying, exposure, and developing step.

Further, the flexible printed wiring board in the present invention can be manufactured, for example, by using a copper-clad laminate in which the above-mentioned polyimide film and copper foil are laminated. Adhesives and non-adhesives can be selected for bonding the polyimide film and copper foil, and the casting method, laminating method, or metallizing method can be selected for those that do not use adhesives. Can be done. Then, if necessary, the circuit can be formed by a subtraction method (for example, a method of forming a circuit in the order of a via hole processing step, a desmear processing step, a via plating step, an etching resist forming step, an etching step, and a resist removing step). .. Further, the semi-additive method (a seed layer such as nickel chrome is provided on a base film such as a polyimide film, a copper sputter layer is provided, and then electrolytic copper plating is performed. After that, an etching resist forming step, an exposure step, a developing step, and copper A method of forming a circuit in the order of the plating step and the plating resist removing step) can also be selected. After that, the circuit board on the flexible printed wiring board can be roughened before use. Examples of the method for roughening the circuit board include buffing, scrubbing, physical polishing such as grinder polishing, and chemical polishing using a microetching agent. In particular, micro-etching is preferable for processing a substrate having a fine pattern. As the micro-etching agent, an etching agent containing sulfuric acid / hydrogen peroxide as a main component, an etching agent containing iron (III) chloride or iron (III) sulfate as a main component, an organic acid-based etching agent, or the like should be used. Can be done. Examples of such micro-etching agents include MEC Etch Bond STZ-3100, STL-3300, CZ-8100, CZ-8101, MEC V Bond BO-7780V, BO-7790V, MEC Bright CB-5004, CB manufactured by MEC Co., Ltd. -5530, SF-5420, CA-91Y, CB-801Y, CB-5602AY and the like can be mentioned. Further, the copper foil of the circuit board may have a rust preventive layer and / or an organic or inorganic primer layer. In addition, those having the effects of a rust preventive layer and a primer layer at the same time are also included. Examples of such rust preventives and primer treatment agents include MEC Etch Bond CL-8300, CL-8301, and MEC Bright CAU-5232C manufactured by MEC Co., Ltd. Examples of the rust preventive treatment and the primer treatment method include a method of immersing the circuit board in a chemical solution and a method of spraying with a spray. Further, a surface treatment may be performed by using a silane coupling agent or the like to improve the adhesion imparting property of the cured film.

[Method of forming insulating film, method of forming pattern]
The photosensitive resin composition according to the present invention can form an insulating film as follows. First, the photosensitive resin composition is applied onto the circuit board and dried to remove the solvent. The coating on the substrate can be performed by screen printing, roller coating, curtain coating, spray coating, rotary coating using a spinner, or the like. The coating film (preferably thickness: 5 μm to 100 μm) is dried at 120 ° C. or lower, preferably 40 to 100 ° C. After drying, it is irradiated with active light such as a dry coating film, ultraviolet rays, visible rays, electron beams, and laser light. At this time, a method of placing a negative photomask, a method of using a negative glass mask in a non-contact manner, or a direct drawing exposure using a laser beam or an LED direct exposure machine may be used. Since the appropriate exposure amount depends on the exposure device, exposure light source, and exposure method used, for example, it can be set using a 21-step step tablet manufactured by Stoffer or a 14-step step tablet manufactured by Kodack, and an exposure sensitivity of one step or more can be obtained. I hope I can. Next, a pattern can be obtained by washing the unexposed portion with a developing solution using various methods such as shower, paddle, immersion or ultrasonic waves. Since the time until the pattern is exposed varies depending on the spray pressure and flow velocity of the developing device and the temperature of the developing solution, it is preferable to find the optimum device conditions as appropriate.

As the developer, it is preferable to use an alkaline aqueous solution, and the developer is water-soluble such as metall, etanol, n-propanol, isopropanol, and N-methyl-2-pyrrolidone. An organic solvent may be contained. Examples of the alkaline compound that gives the above alkaline aqueous solution include hydroxides or carbonates, hydrogen carbonates, and amine compounds of alkali metals, alkaline earth metals, and ammonium ions, and specific examples thereof include sodium hydroxide. , Potassium hydroxide, ammonium hydroxide, sodium carbonate, potassium carbonate, ammonium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate, ammonium hydrogencarbonate, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetraisopropylammonium Hydroxide, N-methyldietanolamine, N-ethyldietanolamine, N, N-dimethylethanolamine, trietanolamine, triisopropanolamine, triisopropylamine, etc. are mentioned, and the aqueous solution exhibits basicity. If there is, other compounds can be used.

Further, the concentration of the alkaline compound that can be suitably used in the developing step of the black resin composition in the present invention is preferably 0.01 to 10% by weight, particularly preferably 0.05 to 5% by weight. Is preferable. The temperature of the developing solution depends on the composition of the black resin composition and the composition of the developing solution, and is generally used at 0 ° C. or higher and 80 ° C. or lower, and more generally at 20 ° C. or higher and 50 ° C. or lower. It is preferable to do so.

The pattern formed by the above developing step is rinsed to remove unnecessary developer residue. Examples of the rinsing solution include water and an acidic aqueous solution.

Next, a cured film having high heat resistance and flexibility can be obtained by performing a heat curing treatment. The cured film is determined in consideration of the wiring thickness and the like, but the thickness is preferably about 2 to 50 μm. The final curing temperature at this time is desired to be cured by heating at a low temperature for the purpose of preventing oxidation of the wiring and the like and not lowering the adhesion between the wiring and the base material. The heat curing temperature at this time is preferably 100 ° C. or higher and 250 ° C. or lower, more preferably 120 ° C. or higher and 200 ° C. or lower, and particularly preferably 130 ° C. or higher and 190 ° C. or lower. When the final heating temperature becomes high, oxidative deterioration of the wiring may progress.

The flexible printed wiring board on which the insulating film is laminated in this manner is gold-plated for switch contacts, anisotropic conductive film (ACF) connection terminals, component mounting, and the like.

[Gold plating]
The gold plating treatment in the present invention comprises at least (I) degreasing treatment, (II) etching treatment, (III) catalytic treatment, (IV) electroless nickel plating treatment, and (V) gold plating treatment, and is a general wet plating. It is not particularly limited as long as it is a processing process called electrolytic gold plating or electroless gold plating.

Further, the gold plating chemical solution used in the (V) gold plating treatment in the present invention includes at least gold salts such as gold potassium cyanide, potassium ditanide cyanide, or sodium gold sulfite, organic acid salts, sulfates, boric acid, and the like. Buffers such as phosphate or sulfamic acid, ethylenediaminetetraacetic acid (EDTA), N'-(2-hydroxyethyl) ethylenediamine-N, N, N'-triacetic acid (HEDTA), nitrilotriacetic acid (NTA), Metal concealing agents such as diethylenetriaminetetraacetic acid (DTPA), triethylenetetraminehexacetic acid (TTHA), or hydroxylidylenefosphon (HEDP), such as cobalt, nickel, silver, iron, palladium, copper, tallium, lead, or arsenic. It is composed of a crystal modifier. Examples of such gold-plated chemicals include product names Flash Gold 2000, Flash Gold VT, Flash Gold 330, Flash Gold NC, Electric Noble AU, Self Gold OTK-IT, and Uyemura & Co., Ltd. manufactured by Okuno Pharmaceutical Co., Ltd. Product Names, Cobright TMX-22, Cobright TMX-23, Cobright TMX-40, Cobright TSB-71, Cobright TSB-72, Cobright TCU-37, Cobright TUC-38, Cobright TAM-LC, Cobright TCL-61, Cobright Examples thereof include TIG-10, Cobright TAW-66, and aurical TKK-51.

In addition, heat treatment may be performed for the purpose of removing water in the cured film after the gold plating treatment. The preferred heating temperature range is 50 to 200 ° C., more preferably 80 to 170 ° C., the preferred heat treatment time is 10 seconds or longer, more preferably 15 minutes or longer, and the heating temperature and treatment time are within a range in which the characteristics of the insulating film can be maintained. Can be selected as appropriate.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

(Synthesis Example 1: Synthesis of base binder polymer (a1) 1)
In a reaction vessel equipped with a stirrer, a thermometer and a nitrogen introduction tube, 30.00 g of methyltriglime (= 1,2-bis (2-methoxyethoxy) ethane) was charged as a polymerization solvent, and norbornene diisocyanate 10. 31 g (0.050 mol) was charged and heated to 80 ° C. with stirring under a nitrogen stream to dissolve it. Methyltriglime containing 50.00 g (0.025 mol) of polycarbonate diol (manufactured by Asahi Kasei Corporation, product name PCDL T5652, weight average molecular weight 2000) and 6.51 g (0.050 mol) of 2-hydroxyethyl methacrylate in this solution. The solution dissolved in 30.00 g was added over 1 hour. This solution was heated and stirred at 80 ° C. for 5 hours to react. The above reaction was carried out to obtain a base binder solution (a1-1). The solid content concentration of the obtained resin solution was 53%, and the weight average molecular weight was 5,200. The solid content concentration, weight average molecular weight and acid value were measured by the following methods.

<Solid content concentration>
The measurement was performed according to JIS K 5601-1-2. As the drying condition, a condition of 170 ° C. × 1 hour was selected.

<Weight average molecular weight>
The measurement was performed under the following conditions.
Equipment used: Tosoh HLC-8220 GPC equivalent Column: Tosoh TSK gel Super AWM-H (6.0 mm ID x 15 cm) x 2 Guard columns: Tosoh TSK guard volume Super AW-H
Eluent: 30 mM LiBr + 20 mM H3PO4 in DMF
Flow velocity: 0.6 mL / min
Column temperature: 40 ° C
Detection conditions: RI: Polarity (+), Response (0.5 sec)
Sample concentration: Approximately 5 mg / mL
Standard product: PEG (polyethylene glycol).

<Acid value>
The measurement was performed according to JIS K 5601-2-1.

(Synthesis Example 2: Synthesis of base binder polymer (a1) 2)
In a reaction vessel equipped with a stirrer, a thermometer and a nitrogen introduction tube, 40.00 g of methyltriglime (= 1,2-bis (2-methoxyethoxy) ethane) was charged as a polymerization solvent, and norbornene diisocyanate 20. 62 g (0.100 mol) was charged and heated to 80 ° C. with stirring under a nitrogen stream to dissolve it. To this solution, 50.00 g (0.025 mol) of polycarbonate diol (manufactured by Asahi Kasei Co., Ltd., product name PCDL T5652, weight average molecular weight 2000), 3.70 g (0.025) of 2,2-bis (hydroxymethyl) butanoic acid. A solution prepared by dissolving 13.02 g (0.100 mol) of 2-hydroxyethyl methacrylate in 40.00 g of methyl triglime was added over 1 hour. This solution was heated and stirred at 80 ° C. for 5 hours to react. The above reaction was carried out to obtain a base binder polymer solution (a1-2). The solid content concentration of the obtained resin solution was 52%, the weight average molecular weight was 8,600, and the acid value of the solid content was 18 mgKOH / g. The solid content concentration, weight average molecular weight and acid value were measured by the same method as in Synthesis Example 1.

(Synthesis Example 3: Synthesis of Base Binder Polymer (a2) 1)
In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel and a nitrogen introduction tube, 100.0 g of methyltriglime (= 1,2-bis (2-methoxyethoxy) ethane) was charged as a solvent for polymerization under a nitrogen stream. The temperature was raised to 80 ° C. with stirring. To this, 12.0 g (0.14 mol) of methacrylic acid, 28.0 g (0.16 mol) of benzyl methacrylate and 60.0 g (0.42 mol) of butyl methacrylate, which were premixed at room temperature, were added. 0.5 g of azobisisobutyronitrile as a radical polymerization initiator was added dropwise from a dropping funnel over 3 hours while keeping the temperature at 80 ° C. After completion of the dropping, the temperature of the reaction solution was raised to 90 ° C. while stirring, and the reaction was reacted by further stirring for 2 hours while maintaining the temperature of the reaction solution at 90 ° C. The above reaction was carried out to obtain a base binder polymer solution (a2-1). The solid content concentration of the obtained resin solution was 50%, the weight average molecular weight was 48,000, and the acid value of the solid content was 78 mgKOH / g. The solid content concentration and the weight average molecular weight were measured by the same method as in Synthesis Example 1.

(Synthesis Example 4: Synthesis of Base Binder Polymer (a2) 2)
17.5 g of methyltriglime (= 1,2-bis (2-methoxyethoxy) ethane) as a polymerization solvent was charged in a separable flask equipped with a stirrer, a thermometer, a dropping funnel, a reflux tube and a nitrogen introduction tube. Next, 20.6 g (0.100 mol) of norbornene diisocyanate was charged and heated to 80 ° C. with stirring under a nitrogen stream to dissolve it. In this solution, 50.0 g (0.025 mol) of polycarbonate diol (manufactured by Asahi Kasei Corporation, product name PCDL T5652, polymerization average molecular weight 2000) and 8.1 g (0.055 mol) of dimethylolbutanoic acid were added to methyl triglime 50. The solution dissolved in 0 g was added over 1 hour. The solution was stirred for 5 hours at 80 ° C. while heating under reflux to obtain an intermediate. Then, 1 g of methanol was added and stirred for 5 hours to obtain a base binder polymer solution (a2-2). The solid content concentration of the obtained resin solution was 50%, the weight average molecular weight was 10,200, and the acid value of the solid content was 42 mgKOH / g. The solid content concentration and the weight average molecular weight were measured by the same method as in Synthesis Example 1.

(Synthesis Example 5: Synthesis of Base Binder Polymer (a2) 3)
In a reaction vessel equipped with a stirrer, a thermometer and a nitrogen introduction tube, 35.00 g of methyltriglime (= 1,2-bis (2-methoxyethoxy) ethane) was charged as a polymerization solvent, and norbornene diisocyanate 10. 31 g (0.050 mol) was charged and heated to 80 ° C. with stirring under a nitrogen stream to dissolve it. To this solution, a solution prepared by dissolving 50.00 g (0.025 mol) of polycarbonate diol (manufactured by Asahi Kasei Corporation, product name PCDL T5652, weight average molecular weight 2000) in 35.00 g of methyl triglime was added over 1 hour. The solution was heated and stirred at 80 ° C. for 2 hours. After completion of the reaction, 15.51 g (0.050 mol) of 3,3', 4,4'-oxydiphthalic dianhydride (hereinafter, ODPA) was added to the above-mentioned reaction solution. After the addition, the mixture was heated to 190 ° C. and reacted for 1 hour. The solution was cooled to 80 ° C. and 3.60 g (0.200 mol) of pure water was added. After the addition, the temperature was raised to 110 ° C. and the mixture was heated under reflux for 5 hours. The above reaction was carried out to obtain a base binder polymer solution (a2-3). The solid content concentration of the obtained resin solution was 53%, the weight average molecular weight was 9,200, and the acid value of the solid content was 86 mgKOH / g. The solid content concentration, weight average molecular weight and acid value were measured by the same method as in Synthesis Example 1.

(Examples 1 to 12 and Comparative Examples 1 to 1)
(A) base binder polymer, (B) insulating film modifying composition, (C) photopolymerization initiator, (D) solvent, (E) pigment, (F) filler containing phosphorus element and other components Addition was made to prepare a photosensitive resin composition. The blending amount of each constituent raw material in the resin solid content and the type of the raw material are shown in Table 1 for Examples and Table 2 for Comparative Examples. The numerical value of each component excluding the solvent (D) indicates the solid content by weight, and the solvent (D) describes the added weight portion including the amount of the solvent contained in the resin solution. After mixing the mixed solution with three rolls, the bubbles in the solution were completely defoamed with a defoaming device, and the following evaluation was carried out.

<1> Binder polymer manufactured by Nippon Kayaku Co., Ltd. (urethane-modified epoxy (meth) acrylate, solid acid value 60.0 mgKOH / g).
<2> Binder polymer manufactured by Nippon Kayaku Co., Ltd. (photosensitive resin using phenol novolac type epoxy resin as a starting material).
<3> Product name of binder polymer (bifunctional urethane acrylate) manufactured by Daicel Ornex Co., Ltd.
<4> Butadiene-based core-shell polymer manufactured by Kaneka Corporation (using epoxy resin jER828 manufactured by Mitsubishi Chemical Corporation as a dispersion medium, core-shell component concentration 40%, volume average particle diameter 230 nm).
<5> Butadiene-based core-shell polymer manufactured by Kaneka Corporation (using epoxy resin jER828 manufactured by Mitsubishi Chemical Corporation as a dispersion medium, core-shell component concentration 37%, volume average particle diameter 180 nm).
<6> Cross-linked urethane beads manufactured by Negami Kogyo Co., Ltd. (organic solvent dispersion, urethane bead component concentration 30%, volume average particle diameter 100 nm).
<7> Product name of organic fine particles manufactured by Negami Kogyo Co., Ltd. (urethane-based organic beads with carbonate skeleton, volume average particle diameter 2.5 μm).
<8> Product name of organic-inorganic composite fine particles (melamine resin / silica composite particles, volume average particle diameter 6.5 μm, hardness 100 MPa) manufactured by Nissan Chemical Industries, Ltd.
<9> Product name of organic fine particles (urethane-based organic beads, average particle diameter 15 μm) manufactured by Negami Kogyo Co., Ltd.
<10> Product name of BASF's oxime ester-based photopolymerization initiator.
<11> Product name of thioxanthone-based photopolymerization initiator manufactured by Nippon Kayaku Co., Ltd.
<12> Product name of α-aminoalkylphenone-based photopolymerization initiator manufactured by BASF Japan Ltd.
<13> Product name of phthalocyanine blue colorant manufactured by BASF Limited.
<14> Product name of yellow colorant manufactured by Clariant Japan Co., Ltd.
<15> Product name of a phosphinate compound (aluminum diethylphosphinate, average particle size 2.5 μm) manufactured by Clariant Japan Co., Ltd.
<16> Product name of radically polymerizable compounds (dipentaerythritol penta and hexaacrylate) manufactured by Nippon Kayaku Co., Ltd.
<17> Bisphenol A type epoxy resin manufactured by Mitsubishi Chemical Corporation (epoxy equivalent 190 g / eq).
<18> Biphenyl type epoxy resin manufactured by Mitsubishi Chemical Corporation (epoxy equivalent 188 g / eq).
<19> Product name of barium sulfate (inorganic filler) manufactured by Sakai Chemical Co., Ltd.
<20> Additive (dicyandiamide) manufactured by Japan Epoxy Resin Co., Ltd.
<21> Product name of butadiene defoamer manufactured by Kyoeisha Chemical Co., Ltd.
<22> Solvent manufactured by Daicel Corporation (ethyl diglucol acetate).
<23> Product name of organic fine particles (urethane-based organic beads, average particle diameter 22 μm) manufactured by Negami Kogyo Co., Ltd.

<Preparation of photosensitive resin composition insulating film (polyimide with rim film) on polyimide film>
The above photosensitive resin composition was applied to a flexible copper-clad laminate (copper foil thickness 12 μm, polyimide film FRS manufactured by Kaneka Co., Ltd.) using a screen printing machine manufactured by Minomat Co., Ltd. 5575 (small screen printer with tilting type). -142 # SW and FRS-522 # SW) were fully etched with a ferric chloride solution and printed on 12.5 μm and 25 μm polyimide films so that the final dry thickness was 20 μm, and printed at 80 ° C. After drying for 20 minutes, a predetermined negative type photomask was placed and exposed to ultraviolet rays (DeepUV lamp manufactured by USHIO Electric Co., Ltd.) having an integrated exposure amount of 200 mJ / cm ² . Then, spray development was carried out for 60 seconds using a solution obtained by heating a 1.0% by weight aqueous sodium carbonate solution to 30 ° C. After the development, the polyimide was sufficiently washed with pure water without using a spray, and then heat-cured in an oven at 150 ° C. for 30 minutes to prepare a polyimide with an insulating film.
In addition, the warpage, solder heat resistance, adhesion evaluation after the gold-plated chemical solution and flux solder test of the polyimide with insulating film prepared under each condition using Formulation Examples 1 to 12 and Comparative Examples 1 to 5 prepared above are as follows. I went by the method of. The evaluation results are shown in Table 3.

(I) Photosensitivity Printing on a 12.5 μm polyimide film obtained by full etching by the same method as in the above item <Preparation of insulating film on polyimide film> so that the final dry thickness is 20 μm. A polyimide film with an insulating film that was exposed, developed, and heat-cured was produced. The surface of the obtained insulating film was observed and judged. However, the exposure was performed by placing a negative photomask having a line width / space width = 100 μm / 100 μm.
〇: A photosensitive pattern of line width / space width = 100/100 μm can be drawn on the surface of the polyimide film without noticeable line thickness or development residue.
X: A photosensitive pattern of line width / space width = 100/100 μm cannot be drawn on the surface of the polyimide film.

(Ii) Warpage after thermosetting The final dry thickness of the 12.5 μm and 25 μm polyimide films obtained by full etching by the same method as in the above item <Preparation of insulating film on polyimide film> is 20 μm. A polyimide film with an insulating film, which was exposed, developed, and heat-cured without patterning, was produced. The produced polyimide film with an insulating film is processed into a 5 cm square, and the warp heights at the four corners are measured. A schematic diagram measuring the amount of warpage of the film is shown in FIG.
◯: The average warp height is less than 20 mm.
Δ: The average warp height is 20 mm or more and does not form a cylinder.
X: The film for the warp test has a tubular shape.

(Iii) Warpage after additional heat history 1
By the same method as the above item <Preparation of insulating film on polyimide film>, the polyimide films of 12.5 μm and 25 μm obtained by full etching are printed so that the final dry thickness is 20 μm without patterning. A polyimide film with an insulating film that was exposed, developed, and heat-cured was prepared. Further, it was additionally heated in an oven at 180 ° C. for 5 minutes. The produced polyimide film with an edge film is processed into 5 cm squares, and the warp heights at the four corners are measured.
◯: The average warp height is less than 20 mm.
Δ: The average warp height is 20 mm or more and does not form a cylinder.
X: The film for the warp test has a tubular shape.

(Iv) Warpage after additional heat history 2
By the same method as the above item <Preparation of insulating film on polyimide film>, the polyimide films of 12.5 μm and 25 μm obtained by full etching are printed so that the final dry thickness is 20 μm without patterning. A polyimide film with an insulating film that was exposed, developed, and heat-cured was prepared. Further, it was passed through a reflow step under peak conditions of 260 ° C. for 10 seconds. The produced polyimide film with an edge film is processed into 5 cm squares, and the warp heights at the four corners are measured.
◯: The average warp height is 20 mm or more and does not form a cylinder.
X: The film for the warp test has a tubular shape.

(V) Folding resistance Exposure, development, and heating without patterning on the surface of a 25 μm-thick polyimide film (Apical 25 NPI manufactured by Kaneka Co., Ltd.) in the same manner as in the above item <Preparation of insulating film on polyimide film>. A cured polyimide film with an insulating film was produced. A polyimide film with an insulating film was cut into strips of 30 mm × 10 mm, bent 5 times at 180 ° with a radius of curvature R = 1.0 mm at 15 mm, and the coating film was visually confirmed to confirm cracks. The test was carried out with a coating film thickness of 20 μm.
◯: The cured film has no cracks.
Δ: The cured film has some cracks.
X: The cured film has cracks.

(Vi) Breaking resistance after additional heat history 1
Polyimide with insulating film exposed, developed, and heat-cured without patterning on the surface of a 25 μm-thick polyimide film (Apical 25NPI manufactured by Kaneka Co., Ltd.) in the same manner as in the above item <Preparation of insulating film on polyimide film>. A film was made. Further, it was additionally heated in an oven at 180 ° C. for 5 minutes. The produced polyimide film with an insulating film was cut into strips of 30 mm × 10 mm, bent 5 times at 180 ° with a radius of curvature R = 1.0 mm at 15 mm, and the coating film was visually confirmed to confirm cracks. ..
◯: The cured film has no cracks.
Δ: The cured film has some cracks.
X: The cured film has cracks.

(Vii) Breaking resistance after additional heat history 2
Polyimide with insulating film exposed, developed, and heat-cured without patterning on the surface of a 25 μm-thick polyimide film (Apical 25NPI manufactured by Kaneka Co., Ltd.) in the same manner as in the above item <Preparation of insulating film on polyimide film>. A film was made. Further, it was passed through a reflow step under peak conditions of 260 ° C. for 10 seconds. The produced polyimide film with an insulating film was cut into strips of 30 mm × 10 mm, bent 5 times at 180 ° with a radius of curvature R = 1.0 mm at 15 mm, and the coating film was visually confirmed to confirm cracks. ..
◯: The cured film has no cracks.
Δ: The cured film has some cracks.
X: The cured film has cracks.

(Viii) Solvent resistance An insulating film of the photosensitive resin composition was prepared on the surface of a copper foil having a thickness of 35 μm by the same method as in the above item <Preparation of insulating film on polyimide film>. However, for exposure, a 100 μm square square opening mask was used, the film was immersed in methyl ethyl ketone at 25 ° C. for 15 minutes and then air-dried, and the state of the film surface was observed.
◯: There is no abnormality in the coating film.
X: Abnormalities such as swelling and peeling occur in the coating film.

(Ix) Solder Heat Resistance An insulating film was prepared on the surface of a 75 μm-thick polyimide film (Apical 75NPI manufactured by Kaneka Co., Ltd.) in the same manner as in the above item <Preparation of insulating film on polyimide film>. However, the exposure was performed by irradiating the entire surface with ultraviolet rays having an integrated exposure amount of 200 mJ / cm ² without using a negative mask. The polyimide with an insulating film was floated in a solder bath completely melted at 280 ° C. so that the insulating film surface was in contact with the solder bath, and was pulled up after 10 seconds. The operation was performed three times, and the adhesive strength of the cured film was evaluated by the grid tape method according to JIS K5400. The test was carried out with a coating film thickness of 20 μm.
◯: Those that do not come off by the grid tape method.
Δ: 95% or more of the squares remain.
X: The remaining amount of squares is less than 80%.

(X) Flux solder heat resistance Insulating film of photosensitive resin composition on the surface of a polyimide film (Apical 75NPI manufactured by Kaneka Co., Ltd.) having a thickness of 75 μm by the same method as in the above item <Preparation of insulating film on polyimide film>. A laminated film was produced. However, the exposure was performed by irradiating the entire surface with ultraviolet rays having an integrated exposure amount of 400 mJ / cm2 without using a negative mask. After applying JS-EU-31 manufactured by Kouki Co., Ltd. on the surface of the insulating film, the mixture was floated in a solder bath completely melted at 280 ° C. so that the insulating film surface was in contact with the insulating film, and then pulled up after 10 seconds. The operation was performed three times, and the adhesive strength of the cured film was evaluated by the grid tape method according to JIS K5400. The test was carried out with a coating film thickness of 70 μm.
◯: Those that do not come off by the grid tape method.
Δ: 95% or more of the squares remain.
X: The remaining amount of squares is less than 80%.

(Xi) Insulation reliability Flexible copper-clad laminate (copper foil thickness 12 μm, polyimide film is Apical 25 NPI manufactured by Kaneka Co., Ltd., copper foil is bonded with polyimide adhesive) Line width / space width = 100 μm A comb-shaped pattern of / 100 μm was prepared, immersed in a 10% by volume sulfuric acid aqueous solution for 1 minute, washed with pure water, and surface-treated with copper foil. Then, an insulating film of the photosensitive resin composition was prepared on the comb-shaped pattern by the same method as the above-mentioned <Preparation of cured film on polyimide film>, and the test piece was adjusted. A DC current of 100 V was applied to both terminals of the test piece in an environmental tester at 85 ° C. and 85% RH, and changes in the insulation resistance value and the occurrence of migration were observed. The test was carried out with a coating film thickness of 20 μm.
◯: A resistance value of 10 to the 8th power or more is shown 1000 hours after the start of the test, and migration, dendrite, etc. do not occur.
X: Migration, dendrite, etc. occur 1000 hours after the start of the test.

(Xii) Evaluation of Adhesion After Gold Plating Test Adhesion is applied so that the polyimide with an insulating film is perpendicular to the wiring direction, and is rubbed firmly so that air does not enter the space portion. Then, a peeling test was conducted at a peeling direction of about 60 °.
◯: No tape peeling Δ: Partial tape peeling occurred, and the remaining fine line pattern was 80%.
X: Tape peeling occurs and the remaining fine line pattern is less than 80%.
The electroless gold plating process was performed as follows.

A support was adhered to the polyimide side of the polyimide with an insulating film produced above, and electroless gold plating was performed according to the following. The electroless gold plating treatment step was carried out as follows according to the standard step of the electroless gold plating Flash Gold 330 of Okuno Pharmaceutical Co., Ltd.

(I) Degreasing treatment, ICP clean S-135K, 40 ° C., 4 minutes (II) etching treatment, sulfuric acid 10 mL / L, sodium pervertate 100 g / L, copper sulfate pentahydrate, 8 g / L, ion exchange Prepared to 1 L with water, 30 ° C., 1 minute (III) catalytic treatment, ICP accelerator (Pd: 0.04%), 30 ° C., 1 minute (IV) electroless nickel plating treatment, ICP-Nicolon-FPF, 84 ° C., 30 minutes (V) gold plating, flash gold 330, 80 ° C., 8 minutes.
After the electroless gold plating treatment, it was washed with water at room temperature and dried at 100 ° C. for 10 seconds.

(Xiii) Evaluation of Adhesion After Heat Resistance of Flux Solder A support is adhered to the polyimide side of the polyimide with an insulating film, and JS-EU-31 manufactured by Kouki Co., Ltd. is applied to the surface of the insulating film, and then completely at 280 ° C. It was floated so that the insulating film surface was in contact with the melted solder bath, and was pulled up after 10 seconds. Perform the operation three times, and (i) stick them together so that they are perpendicular to the wiring direction of the polyimide with insulating film by the same method as the adhesion evaluation after the gold plating test, and rub it firmly to prevent air from entering the space. Paste in. Then, a peeling test was conducted at a peeling direction of about 60 °.
◯: No tape peeling Δ: Partial tape peeling occurred, and the remaining fine line pattern was 80%.
X: Tape peeling occurs and the remaining fine line pattern is less than 80%.

1 Single-sided substrate with a polyimide film with a photosensitive resin composition insulating film 2 Warpage amount 3 Smooth table

Claims (8)

A photosensitive resin composition containing (A) a base binder polymer, (B) a composition for modifying an insulating film, (C) a photopolymerization initiator, and (D) a solvent, wherein the (A) base binder polymer is , (A1) With one or more active energy ray reactive groups in the molecule and a compound having one or more structures selected from ether bond, ester bond, carbonate bond, urethane bond, imide bond, urea bond and amic acid bond. (A2) Two types of compounds having one or more carboxyl groups in the molecule and one or more structures selected from ether bonds, ester bonds, carbonate bonds, urethane bonds, imide bonds, urea bonds and amic acid bonds. Including
The composition for modifying the insulating film (B) contains organic polymer particles (b1) having a volume average particle diameter of less than 1 μm and organic polymer particles (b2) having a volume average particle diameter of 1 μm or more. ) The organic polymer particles in the insulating film modification composition are core-shell polymer particles, polymethylmethacrylate-based spherical organic beads, crosslinked polymethylmethacrylate-based spherical organic beads, crosslinked polybutylmethacrylate-based spherical organic beads, and crosslinked acrylic. Spherical organic beads, acrylic copolymer spherical organic beads, crosslinked styrene spherical organic beads, crosslinked polyacrylic acid ester organic beads, nylon spherical organic beads, silicone spherical organic beads, crosslinked silicone spherical organic beads, and crosslinked urethane. A photosensitive resin composition, which is at least one selected from system spherical organic beads . The composition for modifying the insulating film (B) contains at least organic polymer particles and a compound that can be a dispersion solvent and / or a dispersion medium, and 70% or more of the organic polymer particle components are dispersed in the state of primary particles. The photosensitive resin composition according to claim 1, wherein the photosensitive resin composition is characterized by the above. The photosensitive resin composition according to claim 1 or 2 , wherein the photosensitive resin composition further contains (E) a colorant. The photosensitive resin composition further (F) the photosensitive resin composition according to any one of claims 1 to 3, characterized in that it contains a filler containing a phosphorus element. A cured film which is a cured product of the photosensitive resin composition according to any one of claims 1 to 4 . A method for producing a cured film, which comprises curing the photosensitive resin composition according to any one of claims 1 to 4 by an active energy ray of at least one of light and heat. A flexible printed wiring board having the cured film according to claim 5 . A method for manufacturing a flexible printed wiring board, which comprises forming the photosensitive resin composition according to any one of claims 1 to 4 as an insulating film.

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