JP2009198966A - Photosensitive resin composition, and photosensitive film, permanent mask resist and method for producing permanent mask resist using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive resin composition which satisfies plating resistance, stability, flexibility, chemical resistance and resolution required as a permanent mask resist formed on a film substrate, such as a coverlay of an FPC, and which is excellent particularly in plating resistance and stability. <P>SOLUTION: The photosensitive resin composition includes (A) an epoxy acrylate compound obtained by reacting a resin, obtained by reacting an epoxy resin (a1) with a vinyl group-containing monocarboxylic acid (a2), with a polybasic acid anhydride (a3), (B) an acrylic resin having a carboxyl group, (C) a guanamine compound represented by a general formula (1), (D) a photopolymerizable compound having a polymerizable ethylenically unsaturated group within a molecule, (E) a photopolymerization initiator, and (F) a heat curing agent. There are also provided a photosensitive film, a permanent mask resist and a method for producing the permanent mask resist using the photosensitive resin composition. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a photosensitive resin composition, a photosensitive film using the same, a permanent mask resist, and a method for producing a permanent mask resist.

In recent years, as a kind of printed wiring board, a film-like printed wiring board called a flexible printed circuit (hereinafter referred to as “FPC”) is used particularly for small devices such as cameras, magnetic heads, and mobile phones. It has been. This is because the FPC can maintain its function even when it is bent, and is optimal as a printed wiring board to be accommodated in a small device as described above.
In recent years, there has been an increasing demand for further miniaturization and weight reduction of various electronic devices. By adopting FPC, further miniaturization and weight reduction of the small devices, reduction of product cost, simplification of design, etc. Is gradually progressing.
In the solder resist used for FPC, in addition to the characteristics such as chemical resistance, high resolution, electrical insulation and solder heat resistance, the FPC is bent in the same manner as the solder resist used for ordinary printed wiring boards. So-called flexibility is required that it is not destroyed. In addition, in order to partially thicken or harden the FPC, a reinforcing plate may be attached to the FPC, but such a reinforcing plate is attached using a hot press machine under high pressure and high temperature conditions. Solder resist for FPC is also required to have heat press resistance.
At present, a coverlay formed by punching out a polyimide film with an adhesive is widely used as a solder resist for FPC because the polyimide film has the above-mentioned various characteristics to some extent.
However, the above-described coverlay is expensive because the mold used for die cutting is very expensive, and the manual alignment and bonding work of the die-cut coverlay is required. There is a problem that it ends up.
Furthermore, even though the FPC has been adopted to meet the demand for downsizing of electronic devices, it would be difficult to form a fine pattern if an attempt was made to provide a die cut coverlay on the FPC. There is also a problem.
In order to improve these problems, a resist forming method using a photoresist method is being adopted. In this photoresist method, after a photosensitive resin film is formed on a substrate, the photosensitive resin film is cured by partial exposure, and then an unexposed portion is removed by a development process, thereby forming a fine pattern. can do.
With the adoption of such a photoresist method, various photosensitive resin compositions have been developed. For example, a liquid photosensitive resin composition for FPC containing an unsaturated group-containing polycarboxylic acid resin obtained by reacting an addition product of a specific epoxy resin and an unsaturated monocarboxylic acid with succinic anhydride or the like. It has been proposed (see, for example, Patent Documents 1 and 2).
Further, since FPC needs to be subjected to electrolytic gold plating or electroless gold plating after forming a resist on a substrate, the solder resist is required to have good plating resistance. In particular, electroless plating is often performed in a high-temperature chemical solution, so that the plating solution enters between the resist layer and the substrate on which the circuit is formed, and resist peeling and plating are likely to occur. May cause problems. As a countermeasure, a photosensitive resin composition in which an additive such as an adhesion improver is added to the photosensitive resin composition has been proposed (see, for example, Patent Document 3).
Japanese Patent Application Laid-Open No. 07-207211 Japanese Patent Laid-Open No. 08-134390 Japanese Patent Laid-Open No. 13-183819

However, the conventional photosensitive resin composition containing the additive has problems such as deterioration of film stability. For example, when the heat history during vacuum lamination is long or when working under high temperature conditions, the thermosetting proceeds by the reaction of the thermosetting agent contained in the film, and the desired pattern shape in the subsequent exposure and development processes May not be obtained or a development residue may occur. Therefore, in the conventional photosensitive resin composition, it is the actual condition that both excellent adhesion effect and high stability cannot be achieved.
The present invention has been made in view of the above problems, plating resistance, stability, flexibility required as a permanent mask resist formed on a film-like substrate such as an FPC coverlay, An object of the present invention is to provide a photosensitive resin composition that sufficiently satisfies the chemical resistance and resolution characteristics, and is particularly excellent in plating resistance and stability. Moreover, an object of this invention is to provide the manufacturing method of the photosensitive film, permanent mask resist, and permanent mask resist which used such a photosensitive resin composition.

  In order to achieve the above object, the present invention provides (A) a resin obtained by reacting an epoxy resin (a1) with a vinyl group-containing monocarboxylic acid (a2), a polybasic acid anhydride (a3), An epoxy acrylate compound obtained by reacting (B), an acrylic resin having a carboxyl group, (C) a guanamine compound represented by the following general formula (1), and (D) ethylene polymerizable in the molecule Provided is a photosensitive resin composition comprising a photopolymerizable compound having a polymerizable unsaturated group, (E) a photopolymerization initiator, and (F) a thermosetting agent.

［一般式（１）中、Ｒ^１は水素原子、アルキル基又は置換基を有していてもよいアリール基を示す。］
かかる感光性樹脂組成物によれば、上記構成を有することにより、ＦＰＣのカバーレイのようなフィルム状の基材上に形成される永久マスクレジストとして要求される特性を十分に満足し、特に耐めっき性及びフィルム安定性に優れる永久マスクレジストを形成することができる。

[In General Formula (1), R ¹ represents a hydrogen atom, an alkyl group, or an aryl group which may have a substituent. ]
According to such a photosensitive resin composition, by having the above-described configuration, the characteristics required as a permanent mask resist formed on a film-like substrate such as an FPC coverlay are sufficiently satisfied. A permanent mask resist having excellent plating properties and film stability can be formed.

  In the photosensitive resin composition of the present invention, the epoxy resin (a1) is composed of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a novolac type epoxy resin, and a polyfunctional epoxy resin. It is preferably at least one selected from the group. By using such an epoxy resin, it is possible to obtain a photosensitive resin composition that is further excellent in plating resistance, stability, chemical resistance, resolution and the like of a permanent mask resist obtained by curing.

  Moreover, the photosensitive resin composition of this invention WHEREIN: It is preferable that the acrylic resin which has the said (B) carboxyl group contains (meth) acrylic acid and / or (meth) acrylic-acid alkylester as a copolymerization monomer. By using such an acrylic resin, when laminating a photosensitive resin composition layer composed of a photosensitive resin composition on a printed wiring board on which a circuit is formed, air or the like is involved between the circuits (air Since the voids can be suppressed, a photosensitive resin composition having further excellent plating resistance and flexibility of a permanent mask resist obtained by curing can be obtained.

  Moreover, in the photosensitive resin composition of this invention, it is preferable that the acid value of the acrylic resin which has the said (B) carboxyl group is 50-200 mgKOH / g, and Tg (glass transition temperature) is 30-100 degreeC. Preferably there is. By using such an acrylic resin, it is possible to obtain a photosensitive resin composition having further excellent resolution, electric corrosion resistance, tackiness of the surface of the photosensitive resin composition layer during film formation, and flexibility.

  Moreover, the photosensitive resin composition of this invention WHEREIN: The content rate of the said (C) guanamine compound is 0.01-10 mass% of the total amount of (A) component, (B) component, and (D) component. Preferably there is. By including the component (C) in such a content, a photosensitive resin composition having excellent balance of plating resistance and stability can be obtained.

  Moreover, it is preferable that the photosensitive resin composition of this invention is used for formation of the permanent mask resist of a flexible wiring board. It is for forming the cured film used as a permanent mask on a flexible substrate. Since the permanent mask resist obtained by curing the photosensitive resin composition of the present invention is excellent in plating resistance, stability, flexibility, chemical resistance and resolution, such a photosensitive resin composition is flexible. It can be suitably used for forming a permanent mask resist such as a coverlay provided on the wiring board.

  Moreover, this invention provides a photosensitive film provided with a support body and the photosensitive resin composition layer which consists of the said photosensitive resin composition provided on this support body. According to such a photosensitive film, since the photosensitive resin composition layer is a layer formed using the photosensitive resin composition of the present invention, plating resistance, stability, flexibility, chemical resistance and A permanent mask resist having excellent resolution can be formed.

  Moreover, this invention provides the permanent mask resist formed by hardening the said photosensitive resin composition by light irradiation. Since this permanent mask resist is obtained by curing the photosensitive resin composition of the present invention that exhibits the above-described effects, it is excellent in plating resistance, stability, flexibility, chemical resistance and resolution. For this reason, this permanent mask resist can be suitably used as a coverlay formed on a film-like substrate such as a flexible wiring board.

  Further, the present invention is a method of laminating a photosensitive resin composition layer composed of the photosensitive resin composition on a substrate, and irradiating a predetermined portion of the photosensitive resin composition layer with actinic rays, Provided is a method for producing a permanent mask resist, comprising: an exposure step of forming a photocured portion on the photosensitive resin composition layer; and a developing step of removing a portion other than the photocured portion of the photosensitive resin composition layer. To do. According to this manufacturing method, since the photosensitive resin composition of the present invention that exhibits the above effects is used, it is excellent in plating resistance, stability, flexibility, chemical resistance and resolution, and a flexible printed wiring board. The permanent mask resist which can be used suitably for can be manufactured.

  According to the present invention, each of plating resistance, stability, flexibility, chemical resistance and resolution required as a permanent mask resist formed on a film-like substrate such as an FPC coverlay. Photosensitive resin composition that sufficiently satisfies the characteristics and particularly excellent in plating resistance and stability, photosensitive film provided with such photosensitive resin composition, permanent mask resist formed by such photosensitive resin composition, and production thereof A method can be provided.

In the following, preferred embodiments of the present invention will be described with reference to the drawings as the case may be. In the description of the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant description is omitted. In the present specification, (meth) acrylic acid means acrylic acid and methacrylic acid corresponding thereto, and a mixture thereof, and (meth) acrylate means acrylate and corresponding methacrylate and a mixture thereof. By (meth) acryloyl is meant acryloyl and the corresponding methacryloyl and mixtures thereof.
FIG. 1 is a schematic cross-sectional view showing a preferred embodiment of the photosensitive film of the present invention. The photosensitive film 1 includes a support 10, a photosensitive resin composition layer 20 provided on the support 10, and a protective film 30 provided on the photosensitive resin composition layer 20.
The photosensitive resin composition layer 20 is made of a photosensitive resin composition. The photosensitive resin composition is obtained by reacting (A) a resin obtained by reacting an epoxy resin (a1) with a vinyl group-containing monocarboxylic acid (a2) and a polybasic acid anhydride (a3). An epoxy acrylate compound, (B) an acrylic resin having a carboxyl group, (C) an additive containing a guanamine compound represented by the following general formula (1) as an essential component, and (D) polymerizable in the molecule A photopolymerizable compound having an ethylenically unsaturated group, (E) a photopolymerization initiator, and (F) a thermosetting agent.

Hereinafter, each component will be described in detail.
(A) An epoxy acrylate compound obtained by reacting a resin obtained by reacting an epoxy resin (a1) with a vinyl group-containing monocarboxylic acid (a2) and a polybasic acid anhydride (a3), that is, (A ) Component can be obtained by the following two-stage reaction. In the first reaction (hereinafter referred to as “first reaction” for convenience), the epoxy resin (a1) reacts with the vinyl group-containing monocarboxylic acid (a2). In the next reaction (hereinafter referred to as “second reaction” for convenience), the resin produced in the first reaction reacts with the polybasic acid anhydride (a3).
In the first reaction, a hydroxyl group is generated by an addition reaction between the epoxy group of the epoxy resin (a1) and the carboxyl group of the vinyl group-containing monocarboxylic acid (a2).
The epoxy resin (a1) is not particularly limited, and examples thereof include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, novolac type epoxy resin, biphenyl type epoxy resin, and polyfunctional epoxy resin. Can be mentioned.
Examples of the vinyl group-containing monocarboxylic acid (a2) include acrylic acid, dimer of acrylic acid, methacrylic acid, β-furfurylacrylic acid, β-styrylacrylic acid, cinnamic acid, crotonic acid, and α-cyanocinnamic acid. An acid, sorbic acid, etc. can be used. Further, a half-ester compound, a vinyl group-containing monoglycidyl ether or a vinyl group-containing monoglycidyl ester and a saturated or unsaturated group-containing dibasic compound, which is a reaction product of a hydroxyl group-containing acrylate and a saturated or unsaturated group-containing dibasic acid anhydride A half ester compound which is a reaction product with an acid anhydride can be used. Here, the half ester compound refers to, for example, a compound in which only one of two carboxyl groups is esterified. These vinyl group-containing monocarboxylic acids (a2) can be used alone or in combination of two or more.
The half ester compound can be obtained by reacting a hydroxyl group-containing acrylate, a vinyl group-containing monoglycidyl ether or a vinyl group-containing monoglycidyl ester with a saturated or unsaturated group-containing dibasic acid anhydride in an equimolar ratio. .

Examples of the hydroxyl group-containing acrylate include hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, trimethylolpropane diacrylate, and trimethylol. Propane dimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, glycidyl acrylate, glycidyl methacrylate, and the like can be used.
As the vinyl group-containing monoglycidyl ether or vinyl group-containing monoglycidyl ester, glycidyl (meth) acrylate or the like can be used.

  Examples of the saturated or unsaturated group-containing dibasic acid anhydride include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, Methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, itaconic anhydride and the like can be used.

In the first reaction, the ratio of the epoxy resin (a1) to the vinyl group-containing monocarboxylic acid (a2) is such that the vinyl group-containing monocarboxylic acid (a2) is 1 equivalent to the epoxy group of the epoxy resin (a1). The ratio is preferably 0.7 to 1.05 equivalent, and more preferably 0.8 to 1.0 equivalent.
The epoxy resin (a1) and the vinyl group-containing monocarboxylic acid (a2) can be dissolved and reacted in an organic solvent. Examples of the organic solvent include ketones such as ethyl methyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene, xylene, and tetramethylbenzene, methyl cellosolve, butyl cellosolve, methyl carbitol, butyl carbitol, propylene glycol monomethyl ether, Glycol ethers such as dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether and triethylene glycol monoethyl ether, esters such as ethyl acetate, butyl acetate, butyl cellosolve acetate and carbitol acetate, aliphatic carbonization such as octane and decane Petroleum solvents such as hydrogen, petroleum ether, petroleum naphtha, hydrogenated petroleum naphtha, and solvent naphtha can be used.
In the first reaction, it is preferable to use a catalyst in order to accelerate the reaction. Examples of the catalyst that can be used include triethylamine, benzylmethylamine, methyltriethylammonium chloride, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium iodide, and triphenylphosphine. It is preferable that the usage-amount of a catalyst shall be 0.1-10 mass parts with respect to a total of 100 mass parts of an epoxy resin (a1) and a vinyl group containing monocarboxylic acid (a2).
In the first reaction, in order to prevent polymerization between epoxy resins (a1) or between vinyl group-containing monocarboxylic acids (a2) or between epoxy resin (a1) and vinyl group-containing monocarboxylic acid (a2), polymerization prevention It is preferable to use an agent. As the polymerization inhibitor, for example, hydroquinone, methyl hydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol and the like can be used. The amount of the polymerization inhibitor used is preferably 0.01 to 1 part by mass with respect to 100 parts by mass in total of the epoxy resin (a1) and the vinyl group-containing monocarboxylic acid (a2). 60-150 degreeC is preferable and, as for the reaction temperature of a 1st reaction, 80-120 degreeC is more preferable.
In the first reaction, a vinyl group-containing monocarboxylic acid (a2) and polybasic acid anhydrides such as trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, biphenyltetracarboxylic anhydride, etc. Can be used together.

In the second reaction, it is presumed that the hydroxyl group produced in the first reaction and the hydroxyl group originally present in the epoxy resin (a1) undergo a half-ester reaction with the acid anhydride group of the polybasic acid anhydride (a3). The polybasic acid anhydride (a3) is a saturated or unsaturated group-containing polybasic acid anhydride. Examples of the saturated or unsaturated group-containing polybasic acid anhydride include succinic anhydride, maleic anhydride, tetrahydrophthalic anhydride, phthalic anhydride, methyltetrahydrophthalic anhydride, ethyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, Methylhexahydrophthalic anhydride, ethylhexahydrophthalic anhydride, itaconic anhydride and the like can be used.
In the second reaction, 0.1 to 1.0 equivalent of the polybasic acid anhydride (a3) can be reacted with 1 equivalent of the hydroxyl group in the resin obtained by the first reaction. By adjusting the amount of the polybasic acid anhydride (a3) within this range, the acid value of the component (A) can be adjusted.

  The acid value of the component (A) is preferably 30 to 180 mgKOH / g, more preferably 50 to 150 mgKOH / g, and still more preferably 60 to 120 mgKOH / g. If the acid value is less than 30 mgKOH / g, the solubility of the photosensitive resin composition in a dilute alkali solution tends to decrease, and if the acid value exceeds 180 mgKOH / g, the adhesion to a substrate or the like decreases after curing. Tend. The reaction temperature of the second reaction is preferably 60 to 120 ° C.

Examples of the (A) epoxy acrylate compound used in the present invention include CCR-1218H, CCR-1159H, CCR-1222H, TCR-1335H, ZAR-2001H, ZCR-1569H, etc. (above, Nippon Kayaku Co., Ltd., trade name) ) And other commercial products are available.
When the photosensitive resin composition according to the present embodiment is produced, the content ratio of the solid content of the component (A) (the same applies hereinafter when dissolved in the organic solvent) is the solid content of the component (A) and (B ) It is preferably 50 to 95% by mass, more preferably 55 to 90% by mass, and still more preferably 60 to 80% by mass of the total amount of the solid content of the component.
When this content rate is less than 50 mass%, there exists a tendency for the plating resistance and chemical resistance of permanent mask resists, such as a coverlay formed, to fall. On the other hand, when the blending ratio exceeds 95% by mass, the flexibility of the formed permanent mask resist and the laminating property of the photosensitive resin composition tend to deteriorate.

(B) Acrylic resin having a carboxyl group, that is, (B) component, can be produced by radical polymerization of a polymerizable monomer containing (meth) acrylic acid and (meth) acrylic acid alkyl ester. .
Examples of the (meth) acrylic acid alkyl ester include a compound represented by the following general formula (2), and an alkyl group of the following general formula (2) in which a hydroxyl group, an epoxy group, a halogen, or the like is substituted.

［一般式（２）中、Ｒ^１は水素原子又はメチル基を示し、Ｒ^２は炭素数１〜１２のアルキル基を示す。］
上記一般式（２）のＲ^２で表されるアルキル基としては、例えば、メチル基、エチル基、プロピル基、ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基、ノニル基、デシル基、ウンデシル基、ドデシル基、及びこれらの構造異性体が挙げられる。
上記一般式（２）で表される化合物としては、例えば、（メタ）アクリル酸メチルエステル、（メタ）アクリル酸エチルエステル、（メタ）アクリル酸プロピルエステル、（メタ）アクリル酸ブチルエステル、（メタ）アクリル酸ペンチルエステル、（メタ）アクリル酸ヘキシルエステル、（メタ）アクリル酸ヘプチルエステル、（メタ）アクリル酸オクチルエステル、（メタ）アクリル酸−２−エチルヘキシルエステル、（メタ）アクリル酸ノニルエステル、（メタ）アクリル酸デシルエステル、（メタ）アクリル酸ウンデシルエステル、及び（メタ）アクリル酸ドデシルエステルが挙げられる。これらは１種を単独で又は２種以上を組み合わせて用いることができる。
上記一般式（２）で表される化合物は、耐めっき性の観点から、Ｒ^２が炭素数４〜１２のアルキル基であることが好ましい。

[In General Formula (2), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 1 to 12 carbon atoms. ]
Examples of the alkyl group represented by R ² in the general formula (2) include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, An undecyl group, a dodecyl group, and these structural isomers are mentioned.
Examples of the compound represented by the general formula (2) include (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid propyl ester, (meth) acrylic acid butyl ester, (meth) ) Acrylic acid pentyl ester, (meth) acrylic acid hexyl ester, (meth) acrylic acid heptyl ester, (meth) acrylic acid octyl ester, (meth) acrylic acid-2-ethylhexyl ester, (meth) acrylic acid nonyl ester, ( Examples include meth) acrylic acid decyl ester, (meth) acrylic acid undecyl ester, and (meth) acrylic acid dodecyl ester. These can be used individually by 1 type or in combination of 2 or more types.
In the compound represented by the general formula (2), R ² is preferably an alkyl group having 4 to 12 carbon atoms from the viewpoint of plating resistance.

The component (B) contains (meth) acrylic acid and an alkyl ester of the (meth) acrylic acid from the viewpoint of further improving the plating resistance, flexibility and developability of the permanent mask resist formed on the substrate. Is preferable as a constituent monomer.
The component (B) may further contain a polymerizable monomer other than (meth) acrylic acid and (meth) acrylic acid alkyl ester as a constituent monomer. Examples of such other polymerizable monomers include polymerizable styrene derivatives substituted at the α-position or aromatic ring such as styrene, vinyltoluene, α-methylstyrene, acrylamide such as diacetone acrylamide, and acrylonitrile. , Vinyl alcohol esters such as vinyl-n-butyl ether, (meth) acrylic acid tetrahydrofurfuryl ester, (meth) acrylic acid dimethylaminoethyl ester, (meth) acrylic acid diethylaminoethyl ester, (meth) acrylic acid glycidyl ester 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl (meth) acrylate, (meth) acrylic acid, α-bromo (meth) acrylic acid, α-chloro ( (Meth) acrylic acid, β-furyl (meth) Acrylic acid, β-styryl (meth) acrylic acid, maleic acid, maleic anhydride, monoester maleate, monoethyl maleate, monoisopropyl maleate, fumaric acid, cinnamic acid, α-cyanocinnamic Examples include acid, itaconic acid, crotonic acid, and propiolic acid. You may use these individually by 1 type or in combination of 2 or more types.

The weight average molecular weight of the component (B) is 20,000 to 300,000 from the viewpoint of balancing the good mechanical strength of the cured permanent mask resist with the alkali developability of the photosensitive resin composition. Preferably, it is 30,000 to 150,000, more preferably 40,000 to 100,000. When the weight average molecular weight is less than 20,000, the film formability tends to decrease, and when it exceeds 300,000, the developability tends to decrease.
In addition, the weight average molecular weight in this invention is a value measured by the gel permeation chromatography method, and converted with the analytical curve produced using standard polystyrene.

  (B) It is preferable that the ratio of the polymerizable monomer containing the carboxyl group of a component is 15-50 mol% of all the polymerizable monomers which comprise (B) component. When the carboxyl group content is less than 15 mol%, the developability of the photosensitive resin composition tends to be lowered, and when it exceeds 50 mol%, the pattern formation of the permanent mask resist tends to be difficult. In addition, it is preferable that (B) component is soluble or swellable in aqueous alkali solution from a viewpoint of making the alkali developability of the photosensitive resin composition favorable.

(B) It is preferable that the acid value of a component is 50-200 mgKOH / g, and it is more preferable that it is 60-100 mgKOH / g. If the acid value is less than 50 mgKOH / g, the developability deteriorates and the resolution tends to be insufficient. On the other hand, if it exceeds 200 mgKOH / g, the electric corrosion resistance of the permanent mask resist tends to be insufficient.
Moreover, it is preferable that Tg of (B) component is 30-100 degreeC, and it is more preferable that it is 40-70 degreeC. If the Tg is less than 30 ° C., the tack after forming the coating film at the time of forming the photosensitive film tends to be large, and there is a tendency for problems to occur during lamination. On the other hand, when Tg exceeds 100 ° C., there is a tendency that sufficient flexibility of the formed permanent mask resist cannot be obtained.

When producing the photosensitive resin composition concerning this embodiment, the content rate of the solid content of (B) component is 5-50 mass of the total amount of the solid content of (A) component, and the solid content of (B) component. %, More preferably 10 to 45% by mass, and still more preferably 20 to 40% by mass.
When this content rate is less than 5 mass%, there exists a tendency for the flexibility of the permanent mask resist formed and the laminating property of the photosensitive resin composition to fall. On the other hand, when the blending ratio exceeds 50% by mass, the plating resistance and chemical resistance of a permanent mask resist such as a coverlay formed tend to be lowered.

Moreover, when producing the photosensitive resin composition concerning this embodiment, the total compounding ratio of the solid content of (A) component and the solid content of (B) component is the solid content of (A) component and (B ) The solid content of the component and the total amount of the component (D) are preferably 30 to 90% by mass, more preferably 50 to 85% by mass, and still more preferably 60 to 80% by mass.
When the blending ratio is less than 30% by mass, the photosensitive resin composition layer tends to soften and ooze out from the film end face when the alkali developability is lowered or a photosensitive film is formed. On the other hand, when the blending ratio exceeds 90% by mass, the sensitivity of the photosensitive resin composition when cured by light irradiation and the plating resistance and chemical resistance of the formed permanent mask resist tend to decrease. .

Moreover, the (C) guanamine compound in this embodiment contains the guanamine compound represented by the said General formula (1) as an essential component. In the general formula (1), R ¹ represents a hydrogen atom, an alkyl group or an aryl group which may have a substituent. As said alkyl group, a C1-C20 alkyl group is preferable, a C1-C10 alkyl group is more preferable, and a C1-C5 alkyl group is further more preferable. The aryl group which may have a substituent is preferably a phenyl group which may have a substituent. Especially, among the guanamine compounds represented by the general formula (1), acetoguanamine in which R ¹ is a methyl group or benzoguanamine in which R ¹ is a phenyl group is particularly preferable. Such guanamine compounds can be used alone or in combination of two or more.

  When producing the photosensitive resin composition concerning this embodiment, the content rate of (C) component is 0 of the total amount of solid content of (A) component, solid content of (B) component, and (D) component. The content is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, and still more preferably 0.3 to 1.5% by mass. By including the component (C) at such a content, a photosensitive resin composition having excellent balance of plating resistance and stability can be obtained.

  The photopolymerizable compound having an ethylenically unsaturated group polymerizable in the molecule (D) in the present embodiment is characterized by containing at least one ethylenically unsaturated group in the molecule. For example, a compound obtained by reacting a polyhydric alcohol with an α, β-unsaturated carboxylic acid, 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane, 2,2-bis (4 -((Meth) acryloxypolypropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypolybutoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypoly) Bisphenol A-based (meth) acrylate compounds such as ethoxypolypropoxy) phenyl) propane, compounds obtained by reacting glycidyl group-containing compounds with α, β-unsaturated carboxylic acids, (meth) acrylates having a urethane bond in the molecule Urethane monomers such as compounds, nonylphenoxypolyethyleneoxyacrylate, γ-chloro-β-hydroxypropyl Examples include phthalic acid compounds such as β '-(meth) acryloyloxyethyl-o-phthalate and β-hydroxyalkyl-β'-(meth) acryloyloxyalkyl-o-phthalate, and (meth) acrylic acid alkyl esters. However, it is preferable to use a bisphenol A (meth) acrylate compound as an essential component. These may be used alone or in combination of two or more.

  Examples of the compound obtained by reacting the polyhydric alcohol with an α, β-unsaturated carboxylic acid include, for example, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 2 propylene groups. Polypropylene glycol di (meth) acrylate being 14, polyethylene polyethylene glycol di (meth) acrylate having 2 to 14 ethylene groups and 2 to 14 propylene groups, trimethylolpropane di (meth) acrylate, Trimethylolpropane tri (meth) acrylate, EO-modified trimethylolpropane tri (meth) acrylate, PO-modified trimethylolpropane tri (meth) acrylate, EO, PO-modified trimethylolpropane tri (meth) acrylate, tetramethylolmethanetri (meta) ) Acrylate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and the like.

Examples of the 2,2-bis (4-((meth) acryloxypolyethoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxy) phenyl) propane, 2,2 -Bis (4-((meth) acryloxytriethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytetraethoxy) phenyl) propane, 2,2-bis (4-((meta ) Acryloxypentaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyheptaethoxy) phenyl) Propane, 2,2-bis (4-((meth) acryloxyoctaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxynonane) Xyl) phenyl) propane, 2,2-bis (4-((meth) acryloxydecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyundecaethoxy) phenyl) propane, 2 , 2-bis (4-((meth) acryloxydodecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxytridecaethoxy) phenyl) propane, 2,2-bis (4- ((Meth) acryloxytetradecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxypentadecaethoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxy) Hexadecaethoxy) phenyl) propane and the like, and 2,2-bis (4- (methacryloxypentaethoxy) phenyl) propane is BPE- 00 (made by Shin-Nakamura Chemical Co., Ltd., product name) is commercially available, and 2,2-bis (4- (methacryloxypentadecaethoxy) phenyl) propane is BPE-1300 (Shin-Nakamura Chemical Industry) It is commercially available as a product name). These may be used alone or in combination of two or more.
Examples of the 2,2-bis (4-((meth) acryloxypolyethoxypolypropoxy) phenyl) propane include 2,2-bis (4-((meth) acryloxydiethoxyoctapropoxy) phenyl) propane. 2,2-bis (4-((meth) acryloxytetraethoxytetrapropoxy) phenyl) propane, 2,2-bis (4-((meth) acryloxyhexaethoxyhexapropoxy) phenyl) propane and the like. . These may be used alone or in combination of two or more.

Examples of the (meth) acrylate compound having a urethane bond in the molecule include, for example, a (meth) acryl monomer having an OH group at the β-position, isophorone diisocyanate, 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, 1, 6-reaction products with diisocyanate compounds such as hexamethylene diisocyanate, tris ((meth) acryloxytetraethylene glycol isocyanate) hexamethylene isocyanurate, EO-modified urethane di (meth) acrylate, EO, PO-modified urethane di (meth) acrylate, etc. Is mentioned. Examples of the EO-modified urethane di (meth) acrylate include Shin-Nakamura Chemical Co., Ltd., product name UA-11, and the like. Examples of EO and PO-modified urethane di (meth) acrylate include Shin-Nakamura Chemical Co., Ltd., product name UA-13, and the like.
Note that EO represents ethylene oxide, and the EO-modified compound has a block structure of an ethylene oxide group. PO represents propylene oxide, and the PO-modified compound has a block structure of propylene oxide groups.

  Examples of the nonylphenoxypolyethyleneoxyacrylate include nonylphenoxytetraethyleneoxyacrylate, nonylphenoxypentaethyleneoxyacrylate, nonylphenoxyhexaethyleneoxyacrylate, nonylphenoxyheptaethyleneoxyacrylate, nonylphenoxyoctaethyleneoxyacrylate, nonylphenoxynonaethylene Examples include oxyacrylate, nonylphenoxydecaethyleneoxyacrylate, and nonylphenoxyundecaethyleneoxyacrylate.

  When producing the photosensitive resin composition concerning this embodiment, the content rate of (D) component is 5 of the total amount of solid content of (A) component, solid content of (B) component, and (D) component. It is preferable to set it as -60 mass%, It is more preferable to set it as 10-50 mass%, It is more preferable to set it as 15-40 mass%.

  Examples of the (E) photopolymerization initiator in the present embodiment include substituted or unsubstituted polynuclear quinones (2-ethylanthraquinone, 2-t-butylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2, 3-diphenylanthraquinone, etc.), α-ketaldonyl alcohols (benzoin, pivalon, etc.), ethers, α-hydrocarbon substituted aromatic acyloins (α-phenyl-benzoin, α, α-diethoxyacetophenone, etc.), Aromatic ketones (benzophenone, 4,4′-bisdialkylaminobenzophenone, etc.), thioxanthones (2-methylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, 2-ethylthioxanthone, etc.) 2-methyl-1- [4 -(Methylthio) phenyl] -2-monophorino-propanone-1 may be mentioned, and these may be used alone or in combination of two or more.

When manufacturing the photosensitive resin composition which concerns on this embodiment, the content rate of (E) component is 0 of the total amount of solid content of (A) component, solid content of (B) component, and (D) component. It is preferably 0.01 to 20% by mass, more preferably 0.1 to 10% by mass, and still more preferably 0.5 to 5% by mass.
When the content ratio is less than 0.01% by mass, the sensitivity of the photosensitive resin composition when cured by light irradiation tends to decrease, and when it exceeds 20% by mass, a permanent mask resist is formed. There is a tendency for the plating resistance of the steel to decrease.

As the (F) thermosetting agent in the present embodiment, for example, a thermosetting agent that itself crosslinks by heating, that is, a curing agent that forms a polymer network by applying heat, and (A) component and (B) The hardening | curing agent etc. which react with the carboxyl group of a component and form a three-dimensional structure are mentioned.
A bismaleimide compound is mentioned as a thermosetting agent which bridge | crosslinks itself by heating. Bismaleimide compounds include m-di-N-maleimidylbenzene, bis (4-N-maleimidylphenyl) methane, 2,2-bis (4-N-maleimidylphenyl) propane, and 2,2-bis. (4-N-maleimidyl 2,5-dibromophenyl) propane, 2,2-bis [(4-N-maleimidylphenoxy) phenyl] propane, 2,2-bis [(4-N-malemidyl-2- Various bismaleimide compounds such as methyl-5-ethylphenyl) propane are used as they are or as a mixture. These bismaleimide compounds can be used either alone or modified with various resins.

A block isocyanate compound is mentioned as a hardening | curing agent which reacts with the carboxyl group of (A) component and (B) component by heating, and forms a three-dimensional structure. Examples of the blocked isocyanate compound include polyisocyanate compounds blocked with a blocking agent such as an alcohol compound, a phenol compound, ε-caprolactam, an oxime compound, and an active methylene compound.
Blocked polyisocyanate compounds include 4,4-diphenylmethane disisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene 1,5-diisocyanate, o-xylene diisocyanate, m-xylene Aromatic polyisocyanates such as diisocyanates and 2,4-tolylene dimers, aliphatic polyisocyanates such as hexamethylene diisocyanate, 4,4-methylenebis (cyclohexyl isocyanate) and isophorone diisocyanate, and alicyclic polyisocyanates such as bicycloheptane triisocyanate An aromatic polyisocyanate is preferable from the viewpoint of heat resistance, and an aliphatic polyisocyanate or an alicyclic polyisocyanate is preferable from the viewpoint of preventing coloring.

  When manufacturing the photosensitive resin composition which concerns on this embodiment, the compounding ratio of the solid content of (F) component is the sum total of solid content of (A) component, solid content of (B) component, and (D) component. It is preferable to set it as 5-30 mass% of quantity, and it is more preferable that it is 10-25 mass%. When the blending ratio is within the above range, the plating resistance and chemical resistance of the permanent mask resist to be formed can be further improved.

This photosensitive resin composition is required as a permanent mask resist formed on a film-like substrate such as an FPC coverlay by using the above components (A) to (F) as essential components. Characteristics (particularly plating resistance, stability, flexibility, chemical resistance and resolution) can be sufficiently satisfied.
Furthermore, since the photosensitive resin composition according to this embodiment can be developed with an alkaline aqueous solution, it has good developability. Various characteristics can be improved by using a photosensitive film provided with a photosensitive resin composition layer comprising a photosensitive resin composition containing components (A) to (F) as essential components. In particular, it is possible to efficiently produce a permanent mask resist formed on a film-like substrate such as an FPC coverlay.
In addition to the components (A) to (F) described above, dyes, pigments, plasticizers, stabilizers, and the like can be further added to the photosensitive resin composition of the present embodiment as necessary.

Hereinafter, preferred embodiments of the photosensitive film in the present invention will be described in detail.
As the support 10 and the protective film 30 provided in the photosensitive film 1, a polymer film having heat resistance and solvent resistance, for example, a film made of polyethylene terephthalate, polypropylene, polyethylene, polyester or the like can be used. Of these, a polyethylene terephthalate film is preferred. Moreover, the film used for the support body 10 and the protective film 30 may have a multilayer structure. Further, embossing or the like may be performed on one side or both sides.
The polymerizable film as the support 10 or the protective film 30 is removed from the surface of the photosensitive resin composition layer 20 after a predetermined step or the surface of a permanent mask resist obtained by curing the photosensitive resin composition. Therefore, it is impossible to use a material that cannot be removed or a surface-treated one.
The thickness of the support 10 or the protective film 30 is preferably 5 to 100 μm, and more preferably 10 to 30 μm. When the thickness is less than 5 μm, the circuit coverage tends to be reduced, and when the thickness exceeds 100 μm, it tends to be difficult to form a permanent mask resist pattern.
The photosensitive film 1 which concerns on this embodiment can be manufactured by laminating | stacking the layer of the photosensitive resin composition which concerns on this embodiment on the support body 10. FIG. An example of the method for producing the photosensitive film 1 according to this embodiment will be described in detail below.
First, the photosensitive resin composition containing the components (A) to (F) as essential components is uniformly dissolved in a solvent. The solvent used at this time may be any solvent that dissolves the photosensitive resin composition. For example, ketone solvents (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), ether solvents (methyl solosolv, ethyl cellosolve, etc.) Chlorinated hydrocarbon solvents (dichloromethane, chloroform, etc.), alcohol solvents (methyl alcohol, ethyl alcohol, etc.), etc. can be used. These solvents can be used alone or in combination of two or more.
Next, after the solution containing the photosensitive resin composition is uniformly coated on the polymer film as the support 10, the solvent is removed by one or both of heating and hot air blowing to form a dry film. it can. There is no restriction | limiting in particular in the thickness of a dry film | membrane, It is preferable that it is 10-100 micrometers, and it is more preferable that it is 20-60 micrometers.
The photosensitive film composed of the two layers of the photosensitive resin composition layer 20 and the support 10 thus obtained can be stored as it is or in a roll shape.
Moreover, on the main surface (surface opposite to the side in contact with the support 10) of the photosensitive resin composition layer 20 of the photosensitive film composed of two layers of the photosensitive resin composition layer 20 and the support 10. A photosensitive film 1 having a structure in which the photosensitive resin composition layer 20 is sandwiched between the support 10 and the protective film 30 can be produced by further laminating the protective film 30 on the substrate. The photosensitive film 1 can also be stored as it is or rolled up.

An embodiment of a method for producing a permanent mask resist by forming a photoresist image on a substrate using the photosensitive film 1 according to this embodiment will be described.
The manufacturing method of the permanent mask resist in the present embodiment includes a laminating step of laminating a photosensitive resin composition layer 20 made of a photosensitive resin composition on a substrate, and a predetermined portion of the photosensitive resin composition layer 20 with actinic rays. And an exposure step of forming a photocured portion on the photosensitive resin composition layer 20 and a developing step of removing portions other than the photocured portion of the photosensitive resin composition layer 20.
The substrate is not particularly limited, and a flexible printed wiring board on which wiring is formed by a film-like substrate or etching or the like can be suitably used in addition to a circuit forming substrate and a printed wiring board. A film-like base material or a flexible printed wiring board may be a known material, and the flexible printed wiring board can be obtained, for example, by forming a conductor such as copper on a known flexible substrate by a known method. .
In the laminating step, after removing the protective film 30 of the photosensitive film 1 from the photosensitive resin composition layer 20, the main surface of the photosensitive resin composition layer 20 and the substrate are brought into contact with each other and heated and pressure bonded. The photosensitive resin composition layer 20 and the support 10 are laminated on the base material. This lamination is preferably performed under reduced pressure. Although there is no restriction | limiting in particular as a surface of the base material with which the photosensitive resin composition layer 20 is laminated | stacked, It is preferable that it is the surface of the conductor layer of the flexible printed wiring board in which wiring is formed by an etching etc.
There is no restriction | limiting in particular in the heating temperature of the photosensitive resin composition layer 20 at the time of lamination | stacking, It is preferable to set it as 50-100 degreeC. There is no restriction | limiting in particular in the crimping | compression-bonding pressure at the time of crimping | bonding, It is preferable to set it as 0.2-0.5 MPa, and it is preferable that the surrounding pressure at the time of crimping | compression-bonding is 4000 Pa (30 mmHg) or less.
In this embodiment, since the photosensitive resin composition layer 20 is heated as described above, it is not necessary to pre-heat the base material in advance, but the photosensitive resin composition layer 20 and the base material In order to further improve the adhesion, the base material may be preheated.

In the exposure step, the photosensitive resin composition layer 20 laminated on the substrate is irradiated with an actinic ray using a negative film or a positive film to be exposed imagewise to form a photocured portion. At this time, when the support 10 existing on the photosensitive resin composition layer 20 is transparent, it can be exposed as it is, but when the support 10 is opaque, the support 10 is removed before exposure. There is a need to. From the viewpoint of protecting the photosensitive resin composition layer 20, it is preferable to use the transparent support 10 so that the exposure is performed with the support 10 remaining at the time of exposure.
As the active light source, for example, a well-known active light source such as light generated from carbon arc, mercury vapor arc, xenon arc, or the like can be used. Since the sensitivity of the photopolymerization initiator contained in the photosensitive resin composition layer 20 is usually maximum in the ultraviolet region, it is preferable that the active light source emits ultraviolet rays effectively.
In the development step, after the exposure step, development can be performed by removing an unexposed portion using an alkaline aqueous solution by a known method such as spraying, rocking immersion, brushing, or scraping. In addition, when the support body 10 exists on the photosensitive resin composition layer 20, this is removed from the photosensitive resin composition layer 20 before image development.

  Examples of the base of the alkaline aqueous solution include alkali hydroxides such as lithium, sodium and potassium hydroxide, alkali carbonates such as lithium, sodium and potassium carbonate or bicarbonate, potassium phosphate and sodium phosphate and the like. Examples thereof include alkali metal phosphates, alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate. Of these, an aqueous solution of sodium carbonate is preferred. The pH of the alkaline aqueous solution used for development is preferably 9-11. The development temperature can be adjusted according to the developability of the photosensitive resin composition layer 20. In the alkaline aqueous solution, a surfactant, an antifoaming agent, a small amount of an organic solvent for accelerating development, and the like can be mixed.

Further, after the development, the formed permanent mask resist can be irradiated with ultraviolet rays or heated by a high-pressure mercury lamp for the purpose of further improving the plating resistance, chemical resistance and the like as an FPC coverlay. It is preferable to set it as 0.2-10 J / cm < ² > as the irradiation amount of an ultraviolet-ray, and it is preferable to accompany the heat of 60-120 degreeC at the time of this irradiation. The heating temperature is preferably 120 to 170 ° C., and the heating time is preferably 15 to 90 minutes. Note that either ultraviolet irradiation or heating may be performed first.
In this way, the flexible printed wiring board on which the coverlay having the desired performance is formed is mounted on a device such as a camera after components such as LSI are mounted (soldered).
The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.
(Examples 1-8 and Comparative Examples 1-8)
Components (A) and (B) shown in Table 1 and components (C) to (F) shown in Table 2 were blended in the ratios shown in Tables 1 to 4 to prepare mixed solutions.
In addition, the polymerization average molecular weight of (A) and (B) component was measured by gel permeation chromatography (GPC), and it calculated | required by converting with the analytical curve using a standard polystyrene. The measurement conditions by GPC are shown below.
Pump: Hitachi L-6000 type (manufactured by Hitachi, Ltd., trade name)
Column: Gelpack GL-R420 + Gelpack GL-R430 +
Gelpack GL-R440 (3 in total) (above, manufactured by Hitachi Chemical Co., Ltd., trade name)
Eluent: Tetrahydrofuran Measurement temperature: Room temperature (25 ° C)
Flow rate: 2.05 ml / min Detector: Hitachi L-3300 type RI (manufactured by Hitachi, Ltd., trade name)

＊１：ビスフェノールＡ型エポキシアクリレート化合物（日本化薬株式会社製、商品名）
＊２：クレゾールノボラック型エポキシアクリレート化合物（日本化薬株式会社製、商品名）

* 1: Bisphenol A type epoxy acrylate compound (Nippon Kayaku Co., Ltd., trade name)
* 2: Cresol novolac epoxy acrylate compound (Nippon Kayaku Co., Ltd., trade name)

調製した混合溶液を、支持体としてのポリエチレンテレフタレートフィルム（厚さ：２５μｍ）上に均一に塗布し、１００℃の熱風循環式乾燥器で５分間乾燥して溶剤を除去し、感光性樹脂組成物からなる感光性樹脂組成物層を形成した。感光性樹脂組成物層の乾燥後の厚さは、４０μｍであった。

The prepared mixed solution is uniformly coated on a polyethylene terephthalate film (thickness: 25 μm) as a support, dried for 5 minutes in a 100 ° C. hot-air circulating dryer to remove the solvent, and a photosensitive resin composition The photosensitive resin composition layer which consists of was formed. The thickness after drying of the photosensitive resin composition layer was 40 μm.

Next, a polyethylene film is bonded as a protective film on the main surface of the photosensitive resin composition layer (the surface opposite to the side in contact with the support), and the photosensitive resin composition layer is the support and the protective film. A photosensitive film sandwiched between the two was prepared.
Separately, the copper surface of a substrate for FPC (trade name: F30VC125RC11, manufactured by Nikkan Kogyo Co., Ltd.) in which a 35 μm thick copper foil was laminated on a polyimide substrate was polished with an abrasive brush, washed with water and dried.
After peeling off the polyethylene film, which is a protective film, from the produced photosensitive film, the photosensitive resin composition layer is placed on the FPC board side using a vacuum pressure laminator (manufactured by Meiki Seisakusho Co., Ltd., model: MVLP-500). A laminated sample was prepared by laminating a photosensitive film on the FPC substrate.
Preparation of the laminated sample by the vacuum pressure laminator was performed under the conditions of a molding temperature of 90 ° C., a molding pressure of 0.4 MPa (4 kgf / cm ² ), a vacuum time and a pressurization time of 30 seconds.
After laminating, the sample was cooled to 23 ° C. and allowed to stand for 1 hour or longer. Then, a stowed 21-step tablet was used for the obtained sample, and an HMW-201B type exposure machine manufactured by Oak Manufacturing Co., Ltd. was used. After exposure at cm ² , it was left at room temperature (25 ° C.) for 30 minutes.
Next, spray development was carried out at 30 ° C. for 50 seconds using a 1% by mass aqueous sodium carbonate solution, followed by heat treatment at 160 ° C. for 50 minutes, and further, Toshiba ultraviolet ray irradiation device (rated voltage 200V, Using a rated power consumption of 7.2 kW, one H5600L / 2x lamp), ultraviolet irradiation of 1 J / cm ² was performed to form a permanent mask resist (coverlay) on the FPC substrate.

[Evaluation of folding resistance]
After the FPC board on which the permanent mask resist is formed is immersed in a solder bath at 260 ° C. for 10 seconds and then soldered, it is folded 180 ° by goblet fold, and the occurrence of cracks in the permanent mask resist layer when folded Was visually observed. Evaluation was performed according to the following criteria.
“Good”: No crack occurred, “Bad”: A crack occurred.

[Evaluation of chemical resistance]
After the FPC substrate on which the permanent mask resist is formed is immersed in 2N-hydrochloric acid aqueous solution and 2N-sodium hydroxide aqueous solution at room temperature for 30 minutes, the permeation of the permanent resist pattern opening from the substrate and the occurrence of floating are visually observed. did. Evaluation was performed according to the following criteria.
“Good”: No soaking and lifting occurred, “Bad”: Soaking and lifting occurred.

[Evaluation of plating resistance]
The plating resistance was evaluated by electroless nickel / gold plating. Using an FPC substrate on which a permanent mask resist is formed, degreasing (5 minutes immersion), water washing, soft etching (2 minutes immersion), water washing, pickling (3 minutes immersion), water washing, pre-dip (90 seconds immersion) The electroless nickel plating (85 ° C., 20 minutes) treatment, water washing, electroless gold plating (80 ° C., 10 minutes) treatment, water washing and drying were performed. In addition, the material used for each process is as follows.
Degreasing: PC-455 (Meltex) 25 wt% aqueous solution soft etching: Ammonium persulfate 150 g / L aqueous pickling: 5 vol% sulfuric acid aqueous solution electroless nickel plating: Nimden NPR-4 (Uemura Kogyo Co., Ltd.)
Electroless gold plating: Goblite TAM-55 (manufactured by Uemura Kogyo Co., Ltd.)
After drying, in order to evaluate the gold plating resistance, cellotape (registered trademark) was immediately applied, and this was peeled off in the vertical direction (90 ° peel-off test), and the presence or absence of resist peeling was observed. In addition, the presence or absence of gold plating was observed. In the case where grooving of gold plating occurs, gold deposited by plating is observed under the transparent resist.

[Evaluation of resolution]
The resolution is obtained by closely attaching a photo tool having a stove 21-step tablet and a photo tool having a wiring pattern with a line width / space width of 30 to 200 (unit: μm) as a negative for resolution evaluation, to 21 steps of the stofer. The exposure was performed with an energy amount such that the number of steps remaining after development of the step tablet was 8.0. After spray development at 30 ° C. for 50 seconds using a 1% by mass aqueous sodium carbonate solution, an FPC substrate on which a permanent mask resist was formed was obtained in the same manner as in the method for forming a permanent mask resist, and this was observed with an optical microscope. did. The resolution was evaluated based on the smallest value of the space width between the line widths in which the unexposed portion could be removed cleanly by the development process. The evaluation of the resolution indicates that the smaller the numerical value, the better the value.

[Evaluation of laminate stability]
A circuit with a line width / space width = 100/100 μm was formed on a copper clad laminate having a copper foil thickness of 18 μm using a photosensitive film for etching with a resist thickness of 20 μm (H-Y920, manufactured by Hitachi Chemical Co., Ltd.). . Next, a cupric chloride etching solution (2 mol / liter CuCl ₂ , 2N-HCl aqueous solution, 50 ° C., spray pressure 0.2 MPa (2 kgf / cm ² )) is sprayed for 100 seconds, and the portion not protected by the resist is sprayed. Copper is dissolved, and the resist pattern is further stripped with a stripping solution (3 mass% NaOH aqueous solution, 45 ° C., spray pressure 0.2 MPa (2 kgf / cm ² )), and a copper wiring is formed on the substrate. A plate was made.
Next, using a vacuum pressure laminator (model MVLP-500, manufactured by Meiki Seisakusho Co., Ltd.), the protective film of the photosensitive laminate was peeled off, and then the photosensitive resin composition layer was laminated toward the substrate. The laminator molding temperature at this time was 90 ° C., the molding pressure was 0.4 MPa (4 kgf / cm ² ), and the vacuum time and pressurization time were 30 seconds each. Subsequently, spray development was performed at 30 ° C. for 50 seconds using a 1% by mass aqueous sodium carbonate solution, and the presence or absence of a development residue on the substrate copper circuit was evaluated using an optical microscope.

  The results are summarized in Tables 3 and 4. In Tables 3 and 4, the numerical values in parentheses of the components (A) and (B) represent parts by weight of solid content.

In Comparative Examples 1 to 4 corresponding to Examples 1 to 4, dicyandiamide was used instead of the guanamine compound of Example, but a development residue was observed. Further, in Comparative Examples 5 to 8 corresponding to Examples 5 to 8, benzotriazole was used instead of the guanamine compound of Example, but peeling occurred due to plating resistance, peeling was observed, and plating resistance was poor.
As is apparent from Tables 3 and 4, when the photosensitive resin composition of the present invention is used, it is particularly excellent in plating resistance and laminate stability, and is excellent in bendability, chemical resistance and resolution. It is shown that a permanent mask resist can be obtained.

It is a schematic cross section which shows suitable one Embodiment of the photosensitive film of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Photosensitive film, 10 ... Support body, 20 ... Photosensitive resin composition layer, 30 ... Protective film

Claims (9)

(A) An epoxy acrylate compound obtained by reacting a resin obtained by reacting an epoxy resin (a1) with a vinyl group-containing monocarboxylic acid (a2) and a polybasic acid anhydride (a3); B) an acrylic resin having a carboxyl group, (C) a guanamine compound represented by the following general formula (1), (D) a photopolymerizable compound having an ethylenically unsaturated group polymerizable in the molecule, (E) The photosensitive resin composition formed by containing a photoinitiator and (F) a thermosetting agent.

[In General Formula (1), R ¹ represents a hydrogen atom, an alkyl group, or an aryl group which may have a substituent. ] The epoxy resin (a1) is at least one selected from the group consisting of a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a novolac type epoxy resin, and a polyfunctional epoxy resin. 1. The photosensitive resin composition according to 1. The photosensitive resin composition of Claim 1 or Claim 2 in which the acrylic resin which has the said (B) carboxyl group contains (meth) acrylic acid and / or the (meth) acrylic-acid alkylester as a copolymerization monomer. The photosensitive resin according to any one of claims 1 to 3, wherein the acrylic resin having a carboxyl group (B) has an acid value of 50 to 200 mgKOH / g and a Tg (glass transition temperature) of 30 to 100 ° C. Composition. The content ratio of the (C) guanamine compound is 0.01 to 10% by mass of the total amount of the component (A), the component (B), and the component (D), according to any one of claims 1 to 4. Photosensitive resin composition. The photosensitive resin composition in any one of Claims 1-5 used for formation of the permanent mask resist of a flexible wiring board. A photosensitive film provided with a support body and the photosensitive resin composition layer which consists of a photosensitive resin composition in any one of Claims 1-6 provided on this support body. The permanent mask resist formed by hardening the photosensitive resin composition in any one of Claims 1-6 by light irradiation. A laminating step of laminating a photosensitive resin composition layer comprising the photosensitive resin composition according to any one of claims 1 to 6 on a substrate,
An exposure step of irradiating a predetermined portion of the photosensitive resin composition layer with an actinic ray to form a photocured portion in the photosensitive resin composition layer;
A developing step for removing a portion other than the photocured portion of the photosensitive resin composition layer;
The manufacturing method of the permanent mask resist containing this.

Images