JPH08234430A - Photosensitive resin composition and production of photosensitive film and soldering resist using the same - Google Patents

Abstract

PURPOSE: To enhance work efficiency and to ensure superior flexibility and resistance to the heat of soldering by incorporating a specified polyhydroxy-ether resin, a specified urethane.unsatd. organooligomer, a specified polymerizable compd. having ethylenically unsatd. groups and a specified photo-initiator. CONSTITUTION: Polyhydroxy-ether resin having repeating units represented by formula I, a urethane.unsatd. organooligomer having unsatd. organooxycarbonylimido groups bonded in a chain state to the terminals of a urethane oligomer having a number average mol.wt. of 1,000-100,000, a polymerizable compd. having ethylenically unsatd. groups represented by formula IV and a photo-initiator which forms free radicals under active light are incorporated. The urethane oligomer is obtd. by coupling copolycarbonate contg. repeating units represented by formula II and repeating units represented by formula III in a ratio of 9:1 to 1:9, having hydroxy groups at the terminals and having a number average mol.wt. of 600-1,000 to an org. isocyanate in a chain state. In the formulae I, IV, R<1> is divalent satd. aliphatic hydrocarbon, each of R<2> and R<3> is an alkyl, etc., each of R<4> and R<5> is H, etc., and each of (p) and (q) is a positive integer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive resin composition used for producing printed wiring boards, a photosensitive film using the same, and a method for producing a solder resist.

[0002]

2. Description of the Related Art Liquid or film-like photosensitive resin compositions have been conventionally used for the production of printed wiring boards. For example, a resist used when etching a copper foil of a copper clad laminate having a copper foil laminated on an insulating base material, a solder used for the purpose of limiting the soldering position of a printed wiring board on which wiring is formed and protecting the wiring. It is used as a resist.

The printed wiring board is a plate-like one using an epoxy resin-impregnated glass cloth having a thickness of about 1.0 mm as an insulating base material, and a film using a polyester film or a polyimide film having a thickness of 0.4 mm or less. There are things like a shape. Since a film-shaped product using a polyester film or a polyimide film having a thickness of 0.4 mm or less can be bent as a printed wiring board, it can be bent and attached to a small device such as a camera. Such a film-shaped printed wiring board (also called a flexible printed wiring board)
Is called an FPC, and mounting of components such as an IC on this FPC is also performed by soldering by flow or reflow. Therefore, the solder resist (overlay) is necessary, and it has been conventionally used as an overlay by laminating punched polyimide films or the like, or by printing a printing ink (non-photosensitive).

Further, these overlays also serve the purpose of protecting the wiring after soldering, and their characteristics are high heat resistance during soldering and high flexibility such as no cracking during bending. Especially important. As the overlay, which is the mainstream, a laminate obtained by punching out a polyimide film or the like is sufficient to satisfy this property. However, the film punched with a mold is F
In order to align and bond to a necessary place of the PC, it is necessary to make an expensive mold, and automation is also difficult. Further, in the case of a fine pattern, there is a problem in that it cannot be bonded accurately and the yield is low.

To solve these problems, there is a method of using a photosensitive resin composition, particularly a photosensitive film, as an overlay. The step of using a photosensitive film is to heat-press (laminate) the photosensitive resin layer of a photosensitive film consisting of a support film and a photosensitive resin layer onto the FPC surface on which wiring is formed, and then use a negative film. Imagewise with UV light and then remove (develop) the unexposed areas,
If necessary, it is cured by ultraviolet rays or heat to form an overlay.

Therefore, these steps can be easily automated, and the overlay can be formed accurately because of the photographic method.
However, when a solder mask material for a normal printed wiring board with a thickness of about 1.0 mm is used as an overlay, the solder heat resistance is sufficient, but it is not flexible and problems such as cracking during bending. There is.

[0007]

DISCLOSURE OF THE INVENTION The present invention provides a photosensitive resin composition having good workability and excellent flexibility, solder heat resistance, etc., a method for producing a photosensitive film and a solder resist using the same. To do.

[0008]

The present invention provides (A) general formula (I)

[Chemical 4] (In the formula, R ¹ represents a divalent saturated aliphatic hydrocarbon group, R ²
And R ³ are each independently an alkyl group having 1 to 4 carbon atoms,
Represents an alkoxy group having 1 to 4 carbon atoms or a halogen atom,
x and y are each independently an integer of 0 to 4), a polyhydroxy ether resin having a repeating unit represented by the following formula (B), as a repeating unit, the following formula (a) and the following formula (b)

Embedded image , (A) / (b) is 9/1 to 1/9, and a copolycarbonate having a hydroxy group at the terminal (having a number average molecular weight of 600 to 1,000) and an organic isocyanate are linked in a chain form. A urethane / unsaturated organooligomer having an unsaturated organooxycarbonylimide group bonded to the end of a urethane oligomer (number average molecular weight of 1,000 to 100,000), (C) the following general formula (II)

[Chemical 6] (Wherein, R ⁴ and R ⁵ each independently represent a hydrogen atom or a methyl group, and p and q are positive integers selected so that p + q is 8 to 12). The present invention relates to a photosensitive resin composition containing an unsaturated group-containing polymerizable compound and (D) a photoinitiator that generates free radicals by active light. In the present invention, a solution of the above-mentioned photosensitive resin composition is applied on a substrate, dried, imagewise exposed, and then developed with an aqueous solution containing 1 to 90% by volume of 3-methyl 3-methoxybutyl acetate. The present invention relates to a method for producing a solder resist, which is characterized in that development is performed using a liquid. The present invention also uses the above-mentioned photosensitive film, laminates a layer of the photosensitive resin composition on a substrate, exposes imagewise, and then contains 3-methyl 3-methoxybutyl acetate in an amount of 1 to 90% by volume. The present invention relates to a method for producing a solder resist, which is characterized by performing development using an aqueous solution as a developer.

The photosensitive resin composition of the present invention will be described in detail below. In the photosensitive resin composition of the present invention, the polyhydroxy ether resin having the unit represented by the above general formula (I) which constitutes the component (A) is, for example, 0.985 to 1.015 mol of epihalohydrin and divalent polynuclear. 1 mol of phenol and 0.6 to 1.5 mol of an alkali metal hydroxide (for example, sodium hydroxide, potassium hydroxide) usually in an aqueous medium at a temperature of 10 to 50 ° C. and at least about 60 mol of epihalohydrin. It can be produced, for example, by mixing until it is consumed.

Examples of the divalent polynuclear phenol used here include 2,2-bis (4-hydroxyphenyl) propane, 2,4'-dihydroxydiphenylmethane, bis (2-hydroxyphenyl) methane and bis (4).
-Hydroxyphenyl) methane, bis (4-hydroxy-2,6-dimethyl-3-methoxyphenyl) methane,
1,1-bis (4-hydroxyphenyl) ethane, 1,
2-bis (4-hydroxyphenyl) ethane, 1,1-
Bis (4-hydroxy-2-chlorophenyl) ethane,
1,1-bis (3-methyl-4-hydroxyphenyl)
Ethane, 1,3-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3-phenyl-4-)
Hydroxyphenyl) propane, 2,2-bis (3-isopropyl-4-hydroxyphenyl) propane, 2,
2-bis (2-isopropyl-4-hydroxyphenyl) propane, 2,2-bis (4-hydroxynaphthyl) propane, 2,2-bis (4-hydroxyphenyl) pentane, 3,3-bis (4-hydroxy) Phenyl) pentane, 2,2-bis (4-hydroxyphenyl) heptane, bis (4-hydroxyphenyl) phenylmethane, bis (4-hydroxyphenyl) cyclohexylmethane, 1,2-bis (4-hydroxyphenyl)
-1,2-bis (phenyl) propane, 2,2-bis (4-hydroxyphenyl) -1-phenylpropane,
Bis (hydroxyphenyl) alkanes such as 2,2-bis (3,5-dibromo-4-hydroxyphenyl) propane are preferred.

A particularly preferred polyhydroxy ether resin is the following general formula (III)

[Chemical 7] A condensed polymer derived from 2,2-bis (4-hydroxyphenyl) propane and epichlorohydrin having a structure represented by (in the formula, p is an integer of 50 or more) is included. This polyhydroxy ether resin is a phenoxy resin (trade name UCA) from Union Carbide.
R Phenoxy PKHH, PKHJ or PKF
E) is commercially available. Also, 2,2-bis (3
A phenoxy resin using 5-dibromo-4-hydroxyphenyl) propane as a raw material is also preferable, and is commercially available from Dainippon Ink and Chemicals (trade name: Pratherm EP-500).

The urethane / unsaturated organooligomer which is the component (B) is represented by the following formulas (a) and (b) as repeating units.

Embedded image , (A) / (b) is 9/1 to 1/9, and a copolycarbonate having a hydroxy group at the terminal (having a number average molecular weight of 600 to 1,000) and an organic isocyanate are linked in a chain form. At the end of the urethane oligomer (number average molecular weight of 1,000 to 100,000) represented by the general formula (IV)

[Chemical 9] (Wherein, R ⁶ = R ⁷ - represents an unsaturated organo group containing 1 or more double bonds) in which the unsaturated organo oxycarbonyl imido group represented by bound. The number average molecular weight of the urethane oligomer is 1,000 to 100,000.
It is 0, but if this number average molecular weight is less than 1,000,
The flexibility decreases, and if it exceeds 100,000, the developability decreases. N in the general formula (V) is the number of repeating units in the oligomer, and is preferably 1 to 100, and more preferably 1 to 10.

Such urethane / unsaturated organo-oligomers are represented by the following general formula (V):

[Chemical 10] (In the formula, R ⁸ represents a divalent residue of a copolycarbonate represented by a form in which a hydroxyl group is eliminated from both ends,
R ⁹ represents a divalent aliphatic group or aromatic group displayed in a form in which the isocyanate group is eliminated from the organic isocyanate, and n represents the number of repeating units in the oligomer). Here, the number average molecular weight of the copolycarbonate having a hydroxyl group at the end, which gives a divalent residue of the copolycarbonate represented by the form in which the hydroxyl group is removed from both ends of R ⁸ , is 600 to 1,000. It is said that When this number average molecular weight is less than 600, flexibility is lowered, and when it exceeds 1,000, developability, sensitivity and the like are lowered.

R ⁶ ═R ⁷ — is an unsaturated organo group containing one or more double bonds, and a oxycarbonylimide group (—OOC) is added to the terminal of the urethane oligomer composed of R ⁸ , R ^{9 and the} like.
NH-). The two R ⁶ and R ⁷ sandwiching the double bond may have the same basic skeleton or different basic skeletons. Examples of such an unsaturated organo group include a dimethylene acrylate group (—C ₂ H ₄ OOCCH═CH ₂ ) obtained by reacting hydroxyethyl acrylate,
Trimethylene acrylate group reacted with hydroxypropyl acrylate, tetramethylene acrylate group reacted with hydroxybutyl acrylate, pentamethylene carbonyloxy dimethylene-acrylate (-(CH ₂ ) ₅ COOC ₂ H reacted with hydroxyethyl acrylate / caprolactone adduct ₄ OOCCH = CH ₂ ), pentamethylene carbonyloxy trimethylene-acrylate reacted with hydroxypropyl acrylate / caprolactone adduct, and caprolactone adduct such as pentamethylene carbonyloxy tetramethylene-acrylate group reacted with hydroxybutyl acrylate / caprolactone adduct Or a group reacted with an alkylene oxide adduct, a dimethy compound reacted with a hydroxyethyl acrylate / ethylene oxide adduct Emissions oxy dimethylene - acrylate group _{(-C 2 H 4 OC 2 H} 4 OOCCH = CH 2), methyl hydroxyethyl acrylate propylene oxide adduct reacted dimethylene oxy dimethylene - acrylate group (-C ₂ H ₃ ( CH ₃ ) OC ₂ H ₄ OOCCH = CH ₂ ), an ethyl dimethyleneoxy dimethylene-acrylate group (-C ₂ H ₃ (C ₂ H ₅ ) OC ₂ H ₄ OOCCH) reacted with a hydroxyethyl acrylate / butylene oxide adduct. = CH ₂ ) and the like.

R ⁸ is a divalent residue of a copolycarbonate represented by a form in which a hydroxyl group is eliminated from both ends, and is represented by the hexamethylene carbonate represented by the above formula (a) and the above formula (b). It is a copolymerization group containing the represented pentamethylene carbonate as a main repeating unit. Further, adjacent repeating units may be the same or different from each other, and the repeating may be regular or irregular. R ⁸ is, for example, general formula (VI)

[Chemical 11] (In the formula, r and s are integers) and the like. The content ratio (molar ratio) of hexamethylene carbonate (a) / pentamethylene carbonate (b) of R ₈ is 9/1 to 1/9, and 7.5 / 2.5 to 1.5 / 8.5. Is preferred. Further, when R ₈ is a copolymer of only hexamethylene carbonate (a) and pentamethylene carbonate (b) as represented by the above general formula (VI), in particular,
When (a) / (b) is within the range of 7.5 / 2.5 to 1.5 / 8.5, the oligomer effectively exhibits an amorphous state.

R ₈ may be composed of only hexamethylene carbonate (a) and pentamethylene carbonate (b), but as a repeating unit in the copolymer, the polyol eliminates the hydroxy groups at both ends thereof. It is preferred that the residues represented by the form are included. The residue polyol is displayed in the form desorbed hydroxy group at both ends, for example, 1,4-butanediol residues (- (CH _{2) 4} -), trimethylolpropane residues (-
_{CH 2 C (CH 2 OH)} (C 2 H 5) CH 2 -), trimethylol ethane residue _{(-CH 2 C (CH 2 OH} ) (CH 3) CH
_2- ), a hexanetriol residue (for example, (-(CH ₂ ))
_{4 CH (OH) CH 2 -} ) , etc.), heptane triol residues _{(e.g., (- (CH 2) 5} CH (OH) CH 2 -) , etc.), pentaerythritol residue (-CH ₂ C (CH ₂ OH ) ₂ CH ₂
-) And other polyfunctional polyol residues. In the case of 1,4-butanediol residues, the proportion of the contained polyol residues is preferably 20 mol% or less based on the total amount of hexamethylene carbonate (a) and pentamethylene carbonate (b), It is more preferably 15 mol% or less. Further, in the case of the residue of the above-mentioned polyol other than 1,4-butanediol, it is preferably 10 mol% or less. When a polyol residue is contained, the above hexamethylene carbonate (a) / pentamethylene carbonate (b) is 7.5 / 2.5 to 1.5.
Even if it exceeds the range of /8.5, within the range of 9/1 to 1/9, the oligomer is effectively prevented from gelling.

R ₉ is a divalent aliphatic group or aromatic group represented by a form in which an organic isocyanate is eliminated from the isocyanate group. A specific example will be given while appropriately showing an example of a synthetic reaction process. For example, toluene-2,4-diyl group, toluene-2,6-diyl group, 1-methylene-1,3,3-trimethylcyclohexane-5-yl group reacted with isophorone diisocyanate, hexamethylene group, diphenylmethylene group , (o, m or p) - xylene diyl group _{(- (CH 3) 2 C} 6 H 4 -), methylenebis (cyclohexenyl) group _{(-C 6 H 10 CH 2 C} 6 H 10 -), trimethyl hexamethylene group _{(- (CH 3) 3 C} 6 H 9 -), cyclohexane-1,3-dimethylene group (-CH ₂ C ₆ H ₁₀
CH ₂ -), cyclohexane-1,4-dimethylene group,
Naphthalene-1,5-diyl group, tris (isocyanate phenyl) triphenylene thioether phosphate group dithiophosphate reacted _{((-C 6 H 4) 3} P = S) , and the like.

The above R ₈ and R ₉ are urethane-bonded to form a urethane oligomer. In the main chain, to the extent that the effects of the present invention are not impaired, water, low-molecular-weight polyol, and residues of polyamine and the like are further contained in an ether bond or an imino bond, and the length of the main chain is appropriately adjusted. Longer is preferable. Examples of such chain-extending groups include residues of polyester polyols, polyether polyols, polycarbonate polyols, polyolefin polyols, and the like, each of which is represented by eliminating hydrogen in the hydroxy group.

The number average molecular weight of the urethane / unsaturated organooligomer which is the component (B) is 1,000 to 100,
It is preferably 000. This number average molecular weight is
If it is less than 1,000, the flexibility tends to decrease,
If it exceeds 100,000, the developability tends to decrease.

The polymerizable compound represented by the general formula (II) which is the component (C) is, for example, 2,2'-bis (4-
Methacryloxypentaethoxyphenyl) propane,
There are 2,2'-bis (4-acryloxypentaethoxyphenyl) propane, 2,2'-bis (4-methacryloxytetraethoxyphenyl) propane and the like. Commercially available products are NK ester BPE-500 (Shin Nakamura Manufactured by Chemical Industry Co., Ltd., etc.

The polymerizable compound represented by the general formula (II) is
Used alone or in combination of two or more. In the general formula (II), p and q are positive integers selected so that p + q is 8 to 12. When p + q is less than 8, the flexibility is lowered, and when it is more than 12, the hydrophilicity of the system is increased and the adhesiveness of the developability is lowered.

The component (C) may contain a polymerizable compound other than the component (B) and the polymerizable compound represented by the general formula (II), which has a boiling point of 100 ° C. or higher at normal pressure. Good.

The compounding amount of the polyhydroxy ether resin (A) represented by the general formula (I) is preferably 20 to 90% by weight based on the total amount of (A), (B) and (C). If it is less than 20% by weight, when it is used as a photosensitive film, the photosensitive resin composition layer tends to be soft, and bleeding tends to occur from the end face of the film. 90
If it exceeds 5% by weight, the photosensitivity tends to decrease and the solder heat resistance tends to deteriorate. The blending amount of the urethane unsaturated organo-oligomer (B) is (A), (B) and (C).
It is preferable that the amount is 5 to 75% by weight of the total amount. If it is less than 5% by weight, sufficient flexibility as an overlay tends not to be obtained, and if it exceeds 75% by weight, solder heat resistance tends to be poor. The amount of the ethylenically unsaturated group-containing polymerizable compound (C) represented by the general formula (II) is
The amount is preferably 5 to 75% by weight of the total amount of (A), (B) and (C). If it is less than 5% by weight, sufficient flexibility and solder heat resistance as an overlay may not be obtained at the same time, and if it exceeds 75% by weight, flexibility tends to decrease.

The photosensitive resin composition used in the present invention is a photoinitiator (component (D)) which produces free radicals by actinic light, based on 100 parts by weight of the total amount of components (A) and (B). Is preferably 0.01 to 20 parts by weight. If the photoinitiator is less than 0.01 part by weight, the photosensitivity tends to be low, and if it exceeds 20 parts by weight, the shape of the negative pattern to be formed tends to be poor.

Examples of such a photoinitiator include benzoin methyl ether, benzoin ethyl ether,
Benzoin ethers such as benzoin propyl ether, benzoin isobutyl ether, benzoin phenyl ether, benzophenone, N, N'-tetramethyl-
Benzophenones such as 4,4'-diaminobenzophenone (Michler's ketone) and N, N'-tetraethyl-4,4'-diaminobenzophenone, benzyl dimethyl ketal (manufactured by Ciba Geigy, Irgacure 65)
1), benzyl ketals such as benzyl diethyl ketal, 2,2-dimethoxy-2-phenylacetophenone, p-tert-butyldichloroacetophenone, acetophenones such as p-dimethylaminoacetophenone,
Xanthones such as 2,4-dimethylthioxanthone and 2,4-diisopropylthioxanthone, hydroxycyclohexyl phenyl ketone (Ciba Geigy, Irgacure 184), 1- (4-isopropylphenyl)
-2-Vitroxy-2-methylpropan-1-one (Merck, Darocur 1116), 2-hydroxy-2
-Methyl-1-phenylpropan-1-one (manufactured by Merck, Darocur 1173) and the like can be mentioned, and these can be used alone or in combination of two or more kinds.

As the photoinitiator used as the component (D), for example, 2,4,5-triallylimidazole dimer and 2-mercaptobenzoxazole, leuco crystal violet, tris (4-diethylamino-2). A combination with -methylphenyl) methane and the like is also included. Further, although it has no photoinitiating property by itself, an additive such as a sensitizer system having a better photoinitiating property as a whole when used in combination with the substance, for example,
Tertiary amines such as triethanolamine for benzophenone can be used.

Dyes, pigments, plasticizers, stabilizers and the like may be added to the photosensitive resin composition of the present invention as needed.
In addition, the photosensitive thermosetting resin composition of the present invention has heat resistance,
A publicly known and commonly used (E) thermosetting resin and a cross-linking agent can be used for the purpose of improving properties such as humidity resistance and electric contact resistance. Examples of the thermosetting resin include a combination of a known and commonly used epoxy resin such as bisphenol A, bisphenol F, bisphenol S, phenol novolac, and cresol novolac type, and a known commonly used epoxy curing agent such as amine-based or acid anhydride-based, melamine. Resins, urea resins, amino resins such as guanamine resins and their derivatives, and phenol resins can be used. As the cross-linking agent, amines, isocyanates, blocked isocyanates, oxazoline derivatives and the like can be used.

The photosensitive resin composition of the present invention can also be used as a photosensitive film by coating it on a support film and drying it. As the support, for example, a film made of a polymerizable film (polyethylene terephthalate, polypropylene, polyethylene, etc.) is used, and a polyethylene terephthalate film is preferable.
Since these polymer films must be removable from the photosensitive layer later, they must not be surface-treated or made of a material that makes them impossible to remove. The thickness of these polymer films is 5-100 μm.
Is preferable, and 10-30 μm is more preferable. One of these polymer films may be laminated on both sides of the photosensitive layer as a support film for the photosensitive layer and the other as a protective film for the photosensitive layer.

In producing the photosensitive film, first, the photosensitive resin composition containing the components (A) to (D) is uniformly dissolved in a solvent. The solvent may be any solvent capable of dissolving the photosensitive resin composition, for example, acetone, methyl ethyl ketone, a ketone solvent such as methyl isobutyl ketone, an ether solvent such as methyl cellosolve, ethyl cellosolve, chlorine such as dichloromethane, chloroform. Chemical hydrocarbon solvents, alcohol solvents such as methyl alcohol and ethyl alcohol, etc. are used. These solvents may be used alone or in combination of two or more.

Next, the solution of the photosensitive resin composition is uniformly applied onto the polymer film as the supporting film layer, and then the solvent is removed by heating and / or blowing with hot air to form a dry film. The thickness of the dry film is not particularly limited and is preferably 10 to 100 μm.
More preferably, it is from 0 to 60 μm.

The photosensitive film of the present invention comprising two layers, the photosensitive layer and the polymer film thus obtained, is wound as it is or on the other surface of the photosensitive layer and the protective film is further wound into a roll. Stored.

In producing a photoresist image using the photosensitive film of the present invention, if the protective film is present, after removing the protective film, the photosensitive layer is heated and pressed onto the substrate. However, it is preferable to laminate under reduced pressure. The surface to be laminated is usually an FPC on which wiring is formed by etching or the like.
However, there is no particular limitation. The pressure bonding condition of the photosensitive layer is not particularly limited, but the pressure bonding temperature is preferably 90 to 130 ° C., and the pressure bonding pressure is 2.94 × 10 ⁵ Pa (3 kgf / c
m ² ), and the pressure bonding atmosphere is 4000 Pa
It is preferably (30 mmHg) or less.

When the photosensitive film of the present invention is used, if the photosensitive layer is heated as described above, it is not necessary to preheat the substrate in advance, but in order to further improve the stacking property, the substrate may be preheated. Preheat treatment can also be performed.

The photosensitive layer thus laminated is
It is then imagewise exposed to actinic light using a negative or positive film. At this time, when the polymer film existing on the photosensitive layer is transparent, it may be exposed as it is, and when it is opaque, it is of course necessary to remove it. From the viewpoint of protecting the photosensitive layer, it is preferable that the polymer film is transparent, and the polymer film is allowed to remain and exposed through it. As the active light, light generated from a known active light source such as carbon arc, mercury vapor arc, xenon arc or the like is used. The sensitivity of the photoinitiator contained in the photosensitive layer is usually maximum in the UV region, in which case the actinic light source should be one which emits UV radiation effectively.

After the exposure, if a polymer film is present on the photosensitive layer after exposure, it is removed, and then an aqueous solution containing 1 to 90% by volume of an organic solvent is used.
The unexposed portion is removed and development is performed by a known method such as spraying, rocking dipping, brushing, or scraping. The organic solvent used in the developer may be one that mixes well with water to form a uniform developer, or one that mixes little with water to form a non-uniform developer. As such a developing solution, for example, butyl carbitol, N, N-dimethylformamide, methyl cellosolve, ethyl cellosolve, 3-methyl 3-methoxybutyl acetate, cyclohexanone, toluene, propylene glycol monomethyl ether acetate, methyl ethyl ketone, etc. are used. In particular, 3-methyl and 3-methoxybutyl acetate are preferable. The temperature of the developer used for development is adjusted by the developability of the photosensitive layer. In addition, 1 to this organic solvent
A surfactant, a defoaming agent or the like may be mixed in the 90% by volume aqueous solution.

Further, after the development, as an FPC overlay (also serving as a solder resist), ultraviolet irradiation or heating is performed by a high pressure mercury lamp for the purpose of improving solder heat resistance, chemical resistance and the like. The irradiation amount of ultraviolet rays at the time of ultraviolet irradiation is preferably 0.2 to 10 J / cm ² ,
The temperature at the time of irradiation is preferably 60 to 150 ° C. The heating temperature is preferably 100 to 170 ° C., and the heating time is preferably 15 to 90 minutes.
The order of irradiation with ultraviolet rays and heating may be either. In this way, after the overlay characteristics are given, the LS
Components such as I are mounted (soldered), and devices such as cameras are mounted.

[0037]

EXAMPLES Next, the present invention will be described in more detail by way of examples. "Parts" in the following examples means "parts by weight" unless otherwise specified.

Synthesis Example 1 1,6-hexanediol (a) and 1,5-pentanediol (b) were mixed at a ratio of (a) / (b) = 7.0 / 3.0 (molar ratio). The copolycarbonate was prepared by charging the reactor and introducing phosgene (number average molecular weight 800). Then, in a 5-liter reactor equipped with a stirrer, a thermometer, and a condenser, 888 g of isophorone diisocyanate
And 2400 g of the above copolycarbonate and 0.8 g of dibutyltin dilaurylate were added and kept at 75 to 80 ° C. under a nitrogen atmosphere, and isophorone diisocyanate and the copolycarbonate were reacted for 3 hours to synthesize a urethane oligomer (several). Average molecular weight 5,000). Then
The nitrogen supply was stopped, and 0.7 g each of p-methoxyphenol and di-t-butyl-hydroxy-toluene were added to the reactor.
Each of them, and further, hydroxyethyl acrylate 23
8 g was added, and the urethane oligomer in the reactor was reacted with hydroxyethyl acrylate at 75 ° C. to 80 ° C. for 4 hours to give a urethane / unsaturated organooligomer (B-
1) was obtained (number average molecular weight 6,000).

Synthesis Example 2 In Synthesis Example 1, the organic isocyanate was changed from isophorone diisocyanate to hexamethylene diisocyanate 6
A urethane unsaturated organooligomer (B-2) was obtained by the same operation as in Synthesis Example 1 except that the reaction was carried out with 72 g changed (number average molecular weight 5,000).

Example 1 A solution having the composition shown in Tables 1 and 2 (solution A) was uniformly coated on a polyethylene terephthalate film having a thickness of 25 μm by using the apparatus shown in FIG.
The solvent was removed by drying in a hot air convection dryer 7 at 00 ° C. for about 5 minutes. In FIG. 1, 1 is a polyethylene terephthalate film feeding roll, 2, 3, 4, 9, and 10
Is a roll, 5 is a knife, 6 is a solution of a photosensitive resin composition,
Reference numeral 8 is a polyethylene film feeding roll, and 11 is a photosensitive film winding roll. The thickness of the photosensitive layer after drying was about 50 μm.

Composition of solution A

[Table 1]

[Table 2]

Then, a polyethylene film was bonded as a protective film on the photosensitive layer using the apparatus shown in FIG. 1 to obtain a photosensitive laminate of the present invention.

Separately, the copper surface of an FPC substrate (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 grain brush, washed with water, and dried. A vacuum laminator (made by Hitachi Chemical Co., Ltd., trade name VLM) is attached to this substrate (23 ° C.).
-1 type), heat shoe temperature 110 ° C, atmospheric pressure 4
000Pa (30mmHg) or less, lamination pressure 2.94 × 10 ⁵ P
The photosensitive film was laminated at a (3 kgf / cm ² ).

Then, the obtained sample was mixed with a stoffer
HMW-201B manufactured by Oak Manufacturing Co., Ltd. using a 1-step step tablet and a negative film having a linear line with 150 μm / 150 μm lines / spaces.
The film was exposed at 200 mJ / cm ² with a mold exposing machine, left at room temperature for 30 minutes, and then spray-developed for 100 seconds at 25 ° C. using a 30 wt% aqueous solution of 3-methyl, 3-methoxybutyl acetate. Here, the number of steps of the remaining step tablet is 7
Showed steps. Next, Toshiba Ultraviolet Irradiation Device (rated voltage 200V, rated power consumption 7.2kW, H
Using 5600 L / 2 lamps), ultraviolet irradiation of ³ J / cm ² was performed. Furthermore, heat treatment was performed at 150 ° C. for 60 minutes to obtain an overlay corresponding to a negative film.

This sample was bent at 180 ° in order to evaluate its flexibility, but there were no abnormalities such as cracks in the overlay. Then, rosin-based crack MH-82
260 using 0V (Tamura Kaken Co., Ltd., trade name)
Soldering at 10 ° C. for 10 seconds and solder heat resistance were observed, but there was no abnormality such as blister. Further, here, bending was performed at 180 ° for flexibility evaluation, but there was no abnormality such as cracks in the overlay.

Example 2 An overlay was obtained in the same manner as in Example 1 except that the material of Table 1 used in Example 1 was changed to the material of Table 3.

[Table 3] This sample was bent at 180 degrees to evaluate its flexibility, but there were no cracks or other abnormalities in the overlay. Next, a rosin-based crack MH-820V (manufactured by Tamura Kaken Co., Ltd., product name) was used for soldering treatment at 260 ° C. for 10 seconds, and solder heat resistance was observed, but no abnormalities such as blister were observed. Further, here, bending was performed at 180 degrees for flexibility evaluation, but there were no abnormalities such as cracks in the overlay.

Example 3 An overlay was obtained in the same manner as in Example 1 except that the material shown in Table 1 used in Example 1 was changed to the material shown in Table 4.

[Table 4] This sample was bent at 180 degrees to evaluate its flexibility, but there were no cracks or other abnormalities in the overlay. Next, a rosin-based crack MH-820V (manufactured by Tamura Kaken Co., Ltd., product name) was used for soldering treatment at 260 ° C. for 10 seconds, and solder heat resistance was observed, but no abnormalities such as blister were observed. Further, here, bending was performed at 180 degrees for flexibility evaluation, but there were no abnormalities such as cracks in the overlay.

Example 4 An overlay was obtained in the same manner as in Example 1 except that the material shown in Table 1 used in Example 1 was changed to the material shown in Table 5.

[Table 5] This sample was bent at 180 degrees to evaluate its flexibility, but there were no cracks or other abnormalities in the overlay. Next, a rosin-based crack MH-820V (manufactured by Tamura Kaken Co., Ltd., product name) was used for soldering treatment at 260 ° C. for 10 seconds, and solder heat resistance was observed, but no abnormalities such as blister were observed. Further, here, bending was performed at 180 degrees for flexibility evaluation, but there were no abnormalities such as cracks in the overlay.

Comparative Example 1 An overlay was obtained in the same manner as in Example 1 except that the material shown in Table 1 used in Example 1 was changed to the material shown in Table 6.

[Table 6] When this sample was bent 180 degrees to evaluate flexibility, cracks were generated in the overlay. Further, when rosin-based crack MH-820V (manufactured by Tamura Kaken Co., Ltd., trade name) was used for soldering treatment at 260 ° C. for 10 seconds and solder heat resistance was observed, blistering occurred.

Comparative Example 2 An overlay was obtained in the same manner as in Example 1 except that the material in Table 1 used in Example 1 was changed to the material in Table 7.

[Table 7] When this sample was bent 180 degrees to evaluate flexibility, cracks were generated in the overlay. Further, when rosin-based crack MH-820V (manufactured by Tamura Kaken Co., Ltd., trade name) was used for soldering treatment at 260 ° C. for 10 seconds and solder heat resistance was observed, blistering occurred.

Comparative Example 3 An overlay was obtained in the same manner as in Example 1 except that the material shown in Table 1 used in Example 1 was changed to the material shown in Table 8.

[Table 8] When this sample was bent 180 degrees to evaluate flexibility, cracks were generated in the overlay. Further, when rosin-based crack MH-820V (manufactured by Tamura Kaken Co., Ltd., trade name) was used for soldering treatment at 260 ° C. for 10 seconds and solder heat resistance was observed, blistering occurred.

As is clear from the above, when the photosensitive resin composition of the present invention is used, it is possible to obtain an overlay having good solder heat resistance and bendability (flexibility).

[0053]

EFFECT OF THE INVENTION The photosensitive resin composition according to claim 1 has high sensitivity and good photocuring, and the cured product has heat resistance,
Good bendability (flexibility). Further, the photosensitive resin composition is an etching resist, a plating resist,
It is also suitable for solder resists, FPC overlays, and the like. The photosensitive resin composition according to the second aspect exhibits the effect of the photosensitive resin composition according to the first aspect, and further exhibits the effect of suppressing the edge fusion. In the photosensitive film according to claim 3, the coating film (photosensitive resin layer) has good uniformity,
It has high sensitivity and good photocurability, and the cured product has good heat resistance and bendability (flexibility). This allows
Until now, it has been difficult to process overlays by hand,
It can be easily done by photography. In addition, the photosensitive film,
It is also suitable for etching resists, plating resists, solder resists, FPC overlays, and the like. Claim 4
According to the method for producing a solder resist described above, the photosensitive resin composition can be easily applied to a substrate for FPC, and an overlay having particularly excellent heat resistance can be easily provided. In the method for manufacturing a solder resist according to claim 5, the photosensitive film can be easily applied to a substrate for FPC, and a high quality overlay can be easily performed by a photographic method.

[Brief description of drawings]

FIG. 1 is a schematic view of an apparatus for producing a photosensitive film used in Examples.

[Explanation of symbols]

1 Polyethylene terephthalate film feeding roll 2, 3, 4, 9, 10 roll 5 Knife 6 Solution of photosensitive resin composition 7 Dryer 8 Polyethylene film feeding roll 11 Photosensitive film winding roll

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsuyoshi Nojiri 4-13-1, Higashimachi, Hitachi-shi, Ibaraki Hitachi Chemical Co., Ltd. Ibaraki Research Institute

Claims (5)

[Claims] 1. (A) General formula (I): (In the formula, R ¹ represents a divalent saturated aliphatic hydrocarbon group, R ²
And R ³ are each independently an alkyl group having 1 to 4 carbon atoms,
Represents an alkoxy group having 1 to 4 carbon atoms or a halogen atom,
x and y are each independently an integer of 0 to 4), a polyhydroxy ether resin having a repeating unit represented by the formula (B), and the repeating unit (B) is represented by the following formula (a) and the following formula (b) And (a) / (b) is 9/1 to 1/9, and a copolycarbonate having a hydroxyl group at the terminal (number average molecular weight of 600 to 1,000) and an organic isocyanate are linked in a chain form. A urethane / unsaturated organooligomer in which an unsaturated organooxycarbonylimide group is bonded to the end of a urethane oligomer (number average molecular weight of 1,000 to 100,000), which is represented by the following general formula (II): ] (Wherein, R ⁴ and R ⁵ each independently represent a hydrogen atom or a methyl group, and p and q are positive integers selected so that p + q is 8 to 12). A photosensitive resin composition containing an unsaturated group-containing polymerizable compound and (D) a photoinitiator that generates free radicals by active light. 2. The polyhydroxy ether resin (A) represented by the general formula (I) is contained in an amount of 20 to 90% by weight based on the total amount of (A), (B) and (C), and (B) urethane-free resin. The saturated organo-oligomer is contained in an amount of 5 to 75% by weight of the total amount of (A), (B) and (C), and the (C) ethylenically unsaturated group-containing polymerizable compound represented by the general formula (II) is
5 to 75% by weight of the total amount of (A), (B) and (C) is contained, and (D) the photoinitiator is added to the total amount of (A) and (B) of 0.
The photosensitive resin composition according to claim 1, wherein the photosensitive resin composition is contained in an amount of 01 to 20% by weight. 3. A photosensitive film obtained by applying the photosensitive resin composition according to claim 1, 2 or 3 onto a support film and drying it. 4. A solution of the photosensitive resin composition according to claim 1 or 2 is applied onto a substrate, dried, and imagewise exposed, and then 3-methyl 3-methoxybutyl acetate is added in an amount of 1 to 90.
A method for producing a solder resist, which comprises performing development using an aqueous solution containing a volume% of the developer. 5. The photosensitive film according to claim 3 is used,
A layer of the photosensitive resin composition is laminated on a substrate, exposed imagewise, and then developed using an aqueous solution containing 1-90% by volume of 3-methyl-3-methoxybutylacetate as a developer. Characteristic solder resist manufacturing method.