JPH0772624A - Photosensitive resin composition as well as film, resist ink, resist, solder resist and printed circuit board formed by using the same - Google Patents

Abstract

PURPOSE:To provide the dilute alkaline development type photosensitive resin compsn. which has no tacky adhesiveness even in h contact exposing method by a short precuring time and is wide in a permissible range of the precuring time and the film, resist ink, resist and printed circuit board formed by using the same. CONSTITUTION:This photosensitive resin compsn. contains A. a UV curing resin of weight average mol.wt. 6000 to 30000 obtd. by bringing a (meth)acrylic acid or unsatd. polybasic acid anhydride of chemical equiv. 0.7 to 1.2 per 1 epoxy quiv. of a polymer consisting of (a) 60 to 100mol% glycidyl (meth)acrylate and (b) 0 to 40mol% other ethylenic unsatd. polymer copolymerizable therewith into reaction with this polymer, B. a photopolymn. initiator, C. a diluent and D. a thermosetting component and is developable by a dilute aq. alkaline soln.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a UV-curable photosensitive resin composition which can be developed with a dilute alkali, and a film, a resist ink, a resist, a solder resist and a printed circuit board using the same.

[0002]

2. Description of the Related Art In recent years, as a resist pattern forming method for various consumer and industrial printed circuit boards, in order to cope with high wiring density of printed wiring boards, resolution and A method using a dry film or a liquid developable resist ink, which is excellent in dimensional accuracy, has been occupying a large position.

Among them, as the resist ink, Japanese Patent Publication No. 56-40329 and Japanese Patent Publication No. 57-45785.
Japanese Unexamined Patent Publication (Kokai) Publication No. 2003-242242 discloses a composition containing an ultraviolet curable resin as an essential component, which is obtained by reacting an epoxy resin with an unsaturated monocarboxylic acid and adding a polybasic acid anhydride. Also,
Japanese Unexamined Patent Publication No. 61-243869 discloses a thermosetting resin containing a novolac type epoxy acrylate and an acid anhydride, which is soluble in a dilute alkaline aqueous solution, a UV curable resin, a photopolymerization initiator, a diluent and an epoxy compound. There is disclosed a dilute alkali developing type photosensitive resin composition for a resist ink, which contains a polymerizable component.

In the case of the resist ink containing these novolac type epoxy acrylate polybasic acid anhydride addition type ultraviolet curable resins, a considerably good resist is finally obtained. Since this resist is particularly excellent in physical properties as a solder resist, the above ultraviolet curable resin is widely used for solder resist ink. However, the above-mentioned novolac-type epoxy acrylate-based UV-curable resin exhibits strong adhesiveness because the novolak-type epoxy resin as a synthetic raw material contains an oligomer component having a relatively low molecular weight. At present, this problem has been solved by using a high molecular weight epoxy resin, but the molecular weight of the novolac type epoxy resin supplied as a general-purpose raw material is limited and has a molecular weight of 10,000 or more. It is virtually impossible to solve the sticking problem because it is difficult to desire. In addition, even if a so-called monodisperse type novolac type epoxy resin excluding the oligomer component in the low molecular weight region is used as a raw material or the final composition component is prepared, this tackiness is removed. I don't get it. This drawback is inevitable and essential as long as a novolac epoxy resin is used as a raw material for the UV-curable resin, and the maximum reduction in productivity is caused in the substrate manufacturing process by using the finally prepared resist ink. It is one of the controlling factors.

As a method for forming a resist pattern on a substrate using a resist ink, either one of a contact exposure method (contact method) and a non-contact exposure method (off-contact method) is usually used. More accurate,
A contact exposure method is used to form a resist pattern having a sharp edge shape. In the contact exposure method, first, a resist ink is applied onto a substrate by a dipping method, a spray, a spin coater, a roll coater, screen printing, or the like, and then, for example, 6 to evaporate an organic solvent as a diluent.
Precure is performed at 0 to 120 ° C., and then a negative mask with a pattern is applied so as to be in direct contact with the surface of the dried coating film, chemical lamp, low pressure mercury lamp,
A pattern is formed by irradiating with ultraviolet rays using a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp or the like, and then developing. Therefore, when the negative mask on which the pattern is drawn is directly applied and the coating film after pre-cure has adhesiveness,
This causes problems such as sticking marks on the coating film after exposure and difficulty of peeling the mask, or deterioration of the life and resolution of the mask due to contamination of the mask on which a pattern is drawn.

The novolac type epoxy acrylate resist ink has a strong adhesiveness as described above, but this adhesiveness is lowered to a practical range unless the volatilization and removal of the diluting organic solvent during precure is more complete. I can't. It is considered that the reason is that the novolac-type epoxy acrylate-based component having a relatively low molecular weight is plasticized even by a slight amount of the organic solvent remaining during the precure. For this reason, the pre-cure time usually needs to take about 40 minutes at 70 ° C., but this is a serious problem from the viewpoint of productivity, and if it is not improved, a significant improvement in production efficiency cannot be achieved. .

Therefore, for example, low tackiness (meta)
A polymer of an ethylenically unsaturated monomer such as acrylic or styrene, which contains a carboxyl group and is redispersible in a dilute aqueous alkali solution. It is also conceivable to apply only by the diluent. As an example of this, JP-A-58-58
There is a radiation-polymerizable mixture described in Japanese Patent No. 42040. However, in this case, since the polymer binder itself does not have photocurability, sharp photocurability cannot be obtained even in a resist ink using this, and swelling or peeling during development with a dilute alkaline aqueous solution is not possible. Prone to problems.
In addition, since the photo-curing property is poor, it is necessary to use a large amount of a thermosetting component for maintaining the physical properties of the resist, which tends to bring about a downside such that the allowable range of the precure time becomes short.

By the way, according to the method for synthesizing a polybasic acid anhydride-added UV-curable resin of novolac type epoxy acrylate, an ethylenically unsaturated monomer having an epoxy group, for example, glycidyl (meth) acrylate is used as a monomer unit. A UV-curable resin can be obtained by adding (meth) acrylic acid to the vinyl copolymer described above, and further adding a polybasic acid anhydride. By this method, for example, an ultraviolet curable resin derived from an alkyl acrylate copolymer (hereinafter referred to as "acrylic polybasic acid anhydride-added ultraviolet curable resin") is a novolac type epoxy acrylate ultraviolet curable resin. In comparison with the above, there is a high degree of freedom in selection regarding the molecular weight, softening point, epoxy group content in the copolymer, etc., and these can be adjusted to appropriate values according to the purpose.

Conventionally, in order to apply the acrylic polybasic acid anhydride-added UV-curable resin to a dilute alkali developing type solder resist ink, in all the monomer components in the acrylate polymer as a raw material, It was said that the amount of the unsaturated monomer having an epoxy group needs to be 60 mol% or less. This is because the acrylic polymer, which is industrially widely used for coating, has a general molecular weight of 40,000.
Since it is about 200,000, it is presumed that this is because the optimum blending amount of the unsaturated monomer having an epoxy group in the acrylic polymer in this range was studied. Therefore, the ultraviolet curable resin obtained from the raw material acrylic polymer has to have a relatively high molecular weight accordingly.

Thus, it can be said that the ultraviolet curable resin having a relatively high molecular weight has a high sensitivity in the sense that the redissolvability in a dilute alkali is deteriorated even by a slight exposure, but in the boundary portion of the negative mask attached. It is sensitive to slight light leakage, and the redissolving of the boundary between the exposed and unexposed areas with respect to dilute alkali and the change in dispersibility become slower as a whole, making it difficult to form a resist pattern with sharp edges. Become. In other words, the apparent sensitivity is increased but the exposure width is narrowed, and the exposure amount capable of maintaining the resolution shifts to the low exposure amount side as a whole. The term "exposure width" as used herein refers to the range of exposure amount that can maintain good resolution.

Therefore, if the resolution is to be maintained, the photo-curing of the exposed portion will be incomplete, which directly leads to the deterioration of the physical properties of the solder resist. Therefore, by increasing the molecular weight of the ultraviolet curable resin, the apparent sensitivity only increases, and it cannot be said that the substantial increase in sensitivity is achieved. After all, the solder resist formed by the resist ink using the acrylic polybasic acid anhydride-added UV-curable resin in the above numerical range is a solder heat resistance and gold plating resistance ink using that of the novolac epoxy type. It is considerably inferior to the case of the above, and the whitening or peeling of the formed solder resist is liable to occur, and it is used as a solder resist ink for industrial printed circuit boards or a solder for consumer printed circuit boards. It was difficult to use resist inks that require high quality.

For the above reasons, at present, depending on the required physical properties of the substrate, the acrylic solder resist ink is used with priority on productivity, or the novolac solder resist ink with priority on final resist properties. Must be decided alternatively.

[0013]

An object of the present invention is to provide a dilute alkali-developable photosensitive resin composition which has no stickiness even in a contact exposure method with a short precure time and has a wide precure time permissible range. The object is to provide a cured film formed on a substrate. Another object of the present invention is to provide a resist ink comprising the above photosensitive resin composition,
An object of the present invention is to provide a resist formed on a substrate by using it, which has excellent chemical resistance, solvent resistance, gold plating resistance, heat resistance, and the like, even in a short exposure time, particularly a solder resist. Furthermore, the subject of this invention is providing the printed circuit board manufactured using the said resist ink.

[0014]

The photosensitive resin composition developable with a dilute aqueous alkali solution according to the present invention comprises: (A) Glycidyl (meth) acrylate 60 to 10
A polymer consisting of 0 mol% and (b) 0 to 40 mol% of another ethylenically unsaturated monomer copolymerizable therewith with 0.7 to 1.2 chemicals per 1 epoxy equivalent of the polymer. Weight average molecular weight 6000 to be obtained by reacting an equivalent amount of (meth) acrylic acid and a saturated or unsaturated polybasic acid anhydride
30,000 UV curable resins, B. A photopolymerization initiator, C.I. Diluent and D.I. It contains a thermosetting component.

<A. About UV-Curable Resin> The UV-curable resin used in the present invention is (a) 60 to 100 mol% of glycidyl (meth) acrylate and (b) another ethylenically unsaturated monomer copolymerizable therewith. ~ 40 mol%
It can be obtained by reacting a polymer consisting of (1) with 0.7 to 1.2 chemical equivalents of (meth) acrylic acid and saturated or unsaturated polybasic acid anhydride per epoxy equivalent of the polymer. .

The glycidyl (meth) acrylate as the component (a) is obtained by introducing a glycidyl group into the above-mentioned polymer to obtain (meth)
It is blended for the purpose of introducing an ethylenically unsaturated double bond by adding acrylic acid and imparting ultraviolet curability to the polymer, but the amount is 60 to 60 relative to the total amount of unsaturated monomers in the polymer. It must be compounded in the range of 100 mol%. At the same time, the weight average molecular weight of the ultraviolet curable resin must be 6000 to 30,000, and a particularly suitable range is 10,000 to 25,000.

The reasons why the above ranges of the compounding ratio and the average molecular weight must be satisfied at the same time are as follows. That is, in order to achieve the object of the present invention, the resist ink must have high resolution and high sensitivity by maintaining a wide exposure width. For the first time,
The resist ink in the exposed area is sufficiently cured, while the resist ink is characterized in that the removability at the time of development is not deteriorated by a degree of curing due to slight light leakage at the boundary portion of the attached negative mask. Due to the sufficient curability of the resist in the exposed area, the excellent solder heat resistance, chemical resistance, solvent resistance, gold plating resistance and heat resistance, which are the objects of the present invention, can be achieved.

However, when the above ultraviolet curable resin having an average molecular weight of more than 30,000 is used,
The solubility of the resist ink in a dilute alkaline solution rapidly decreases even at an extremely low exposure amount. This is because, in the range of the above-mentioned molecular weight, in addition to the fact that the solubility in the dilute alkaline aqueous solution is already lost even when unexposed, the ethylenically unsaturated group in the UV-curable resin molecule is slightly photopolymerized. This is because even if it is involved, a rapid increase in molecular weight occurs. This means that, when expressed in terms of the ethylenically unsaturated group content per 1 kg of the ultraviolet curable resin, if the content of the ethylenically unsaturated group is the same, the molecular weight increasing rate by exposure is the UV curable resin before exposure. This is due to the empirical fact that the larger the molecular weight, the more rapidly it rises, so to speak, as a quadratic curve.

Therefore, the weight average molecular weight is 30,000.
In a resist ink using a larger UV curable resin, the removability at the time of development is deteriorated even by curing due to slight light leakage at the boundary portion of the attached negative mask. The exposure width must be secured by lowering the content of the unsaturated group.
As a result, the exposed portion itself is insufficiently cured, and the physical properties of the final resist cannot withstand high requirements.

In the ultraviolet curable resin used in the present invention,
In view of the above problems, the weight average molecular weight is limited to a low range of 30,000 or less, and the content of ethylenically unsaturated groups is increased as much as possible. Specifically, in order to pendant the ethylenically unsaturated group, the amount of the glycidyl (meth) acrylate monomer in the raw polymer is 60 mol% or more based on the total amount of the monomers in the raw polymer, Preferably 63
It should be at least mol%. Thereby, the ultraviolet curable resin, despite having a high content of ethylenically unsaturated groups, does not deteriorate the removability during development with a molecular weight increase due to a slight exposure, and has a wide exposure width, In the appropriately exposed area, the presence of a sufficient amount of the ethylenically unsaturated group makes it possible to prepare a resist ink having excellent sensitivity and excellent resolution.

For the above reasons, the resist obtained by the resist ink of the present invention shows excellent physical properties because the photo-curing is sufficiently advanced, and particularly in the case of the solder resist, the solder heat resistance is remarkably improved. Can be achieved. The UV-curable resin used in the present invention has a low molecular weight as described above and is excellent in pigment dispersibility because it is close to an acrylic dispersant, and thus excellent in storage stability of the final composition. ing.

The above polymer can be obtained by a known polymerization method such as solution polymerization or emulsion polymerization. Explaining the case of using solution polymerization, for example, the above (a)
The unsaturated monomer mixture composed of the component (b) and the component (b) is polymerized by a method of adding a polymerization initiator in a suitable organic solvent and heating and stirring under a nitrogen stream, or by a boiling point polymerization method.

Examples of the organic solvent include ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, and ethyl acetate.
Examples thereof include butyl acetate, cellosolve acetate, butyl cellosolve acetate, butyl carbitol acetate, propylene glycol monomethyl ether acetate, and other acetic acid esters, and dialkyl glycol ethers. These organic solvents can be used alone or in combination.

Examples of the polymerization initiator include hydroperoxides such as diisopropylbenzene hydroperoxide, cumene hydroperoxide and t-butyl hydroperoxide, and dicumyl peroxide, 2,5-dimethyl-2,5. -Di- (t-butylperoxy) -hexane, 1,3-bis- (t-butylperoxyisopropyl) -benzene, t-butylcumyl peroxide, di-t-butylperoxide,
Dialkyl peroxides such as 2,5-dimethyl-2,5-di- (t-butylperoxy) -hexyne-3,
And isobutyryl peroxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide,
Diacyl peroxides such as benzoyl peroxide and acetyl peroxide, and ketone peroxides such as methyl ethyl ketone peroxide, methyl isobutyl ketone peroxide, cyclohexanone peroxide, and acetylacetone peroxide, and t
-Butyl peroxy vivarate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxy-
Alkyl peresters such as 3,5,5-trimethylhexaate, t-butylperoxyacetate and t-butylperoxybenzoate, and diisopropyl peroxydicarbonate, di-2-ethylhexyl peroxydicarbonate, diisopropyl peroxy Peroxydicarbonates such as dicarbonate and di-sec-butylperoxydicarbonate, and azo compounds such as azobisisobutyronitrile, methyl 2,2′-azobisisobutyrate, azobiscyanovaleronitrile,
1,1′-azobis (cyclohexene-1-carbonitrile), 2,2′-azobis {2-methyl-N- (2-
Azo compounds such as (hydroxyethyl) -propionamide}.

The molecular weight of the above-mentioned polymer is required to be in the range corresponding to the required molecular weight of the ultraviolet-curable resin obtained using the polymer. Therefore, in order to obtain this relatively low molecular weight polymer, alkyl halides, polyhalides, halide-based chain transfer agents such as bromophenacyldimethylsulfonium ylide, and alkyl mercaptans, thioglycols, glycol dimercaptoacetates. , Thiocarboxylic acids such as thiomalic acid, thiocarboxylic acids such as thiomalic acid, sulfur compound chain transfer agents such as dithiocarbamate, thioamide and thiourea, and terpenoid chain transfer agents such as limonene, and dimers such as α-methylstyrene dimer Type chain transfer agents, addition cleavage type chain transfer agents such as α-benzyloxy-substituted vinyl monomers, and ylide chain transfer agents such as sulfonium ylide, or high polymerization temperature and pressure polymerization may be employed. However, ring opening of epoxy group does not occur during polymerization Must be a condition.

The component (b) may be any ethylenically unsaturated monomer copolymerizable with the component (a), such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, Butyl (meth) acrylate, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, Lauryl (meth) acrylate, myristyl (meth) acrylate, cetyl (meth)
Linear, branched or alicyclic alkyl (meth) acrylates such as acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, and hydroxyethyl (meth)
Acrylate, methoxyethyl (meth) acrylate,
Ethylene glycol ester (meth) acrylates such as ethoxyethyl (meth) acrylate, diethylene glycol mono (meth) acrylate, triethylene glycol mono (meth) acrylate, methoxydiethylene glycol (meth) acrylate, and similar propylene glycol (meth) acrylates , Butylene glycol mono (meth) acrylate, glycerol mono (meth) acrylate, etc., and aromatic (meth) acrylates such as benzyl (meth) acrylate, and (meth) acrylamide, N-methyl (meth) acrylamide, N -Propyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, N-tert-octyl (meth) acrylamide, diacetone (meth) acrylamide, etc. Acrylamide compounds, and other vinyl pyrrolidone, acrylonitrile, vinyl acetate,
There are styrene, α-methylstyrene, vinyl ether and the like, and these can be used alone or in combination. These are used to adjust the content of ethylenically unsaturated groups that are finally introduced into the UV curable resin, the hardness of the coating film after pre-cure, and the hardness of the final resist, or the dispersibility and solubility. It is used for adjusting workability in the process of using the resist ink, such as printability.

The amount of (meth) acrylic acid added to the above polymer is 0.7 per 1 epoxy equivalent of the polymer.
.About.1.2 chemical equivalents, that is, 0.7 to 1.2 chemical equivalents with respect to the glycidyl (meth) acrylate in the polymer. If the blending amount is less than 0.7 chemical equivalents, there are too many glycidyl groups remaining in the ultraviolet curable resin, and the developability after exposure is likely to decrease due to curing during pre-cure. If the chemical equivalent is exceeded, the remaining unreacted (meth) acrylic acid becomes a problem.

Examples of saturated or unsaturated polybasic acid anhydrides include succinic anhydride, methylsuccinic anhydride, maleic anhydride, citraconic anhydride, glutaric anhydride, itaconic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, Dibasic acid anhydrides such as methyltetrahydrophthalic anhydride, methylnadic acid anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride, and trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, and methylcyclohexenetetra An acid anhydride having three or more basic acids such as a carboxylic acid anhydride can be mentioned. The acid anhydride is used mainly for the purpose of imparting an acid value to the UV-curable resin so that the UV-curable resin can be redispersed and redissolved in a dilute aqueous alkali solution. The acid value of the UV-curable resin is preferably 25 to 150. It is blended so as to be in the range, and particularly when it is 40 to 100, the optimum effect is obtained. If the acid value is less than 25, the developability will be poor,
On the other hand, if it exceeds 150, residual carboxyl groups in the resist after curing may cause problems such as deterioration in electrical characteristics, electrolytic corrosion resistance and water resistance, but these problems are serious drawbacks for a solder resist.

The addition reaction of the (meth) acrylic acid and the saturated or unsaturated polybasic acid anhydride can be carried out by a known method. For example, the addition reaction of (meth) acrylic acid is performed by adding hydroquinone to a solvent solution of the above polymer,
Thermal polymerization inhibitors such as hydroquinone monomethyl ether,
And a tertiary amine such as benzyldimethylamine and triethylamine, and a quaternary ammonium salt such as trimethylbenzylammonium chloride and methyltriethylammonium chloride, or a catalyst such as triphenylstibine by a conventional method, Preferably 5
The reaction may be performed at a reaction temperature of 0 to 150 ° C, particularly preferably 60 to 120 ° C. The addition reaction of the saturated or unsaturated polybasic acid anhydride can also be carried out by the same method as described above.

The compounding amount of the above-mentioned ultraviolet curable resin is preferably in the range of 2 to 60% by weight based on the total amount of the photosensitive resin composition.

<B. Regarding Photopolymerization Initiator> Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and other benzoins and their alkyl ethers; and acetophenone and 2,2-dimethoxy-2-phenylacetophenone. Acetophenones such as 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone and 1-hydroxycyclohexylphenyl ketone, and 2-methylanthraquinone, 2
Anthraquinones such as amylanthraquinone, and thioxanthones such as 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-diisopropylthioxanthone, 1-chloro-4-propoxythioxanthone, and acetophenone Ketals such as dimethyl ketal and benzyl dimethyl ketal, and benzophenone, 3,3-dimethyl-4-methoxybenzophenone, 3,3 ′, 4,4 ′
-Tetra- (t-butylperoxylcarbonyl) benzophenone, benzophenones or xanthones such as 4-benzoyl-4'-methyldiphenyl sulfide, and 2-methyl-1- [4- (methylthio) phenyl]-
2-morpholino-propan-1-one, 2-benzoyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,4,4′-bis-diethylaminobenzophenone or the like containing a nitrogen atom, And “Lucillin TPO” (2,4,6-trimethylbenzoyldiphenylphosphine oxide manufactured by BASF) and the like, and these are benzoic acid-based or p-dimethylaminobenzoic acid ethyl ester, p-dimethylaminobenzoic acid isoamyl. You may use together with well-known photopolymerization accelerators, such as ester and a tertiary amine type | system | group, such as 2-dimethylamino ethyl benzoate. These photopolymerization initiators are used alone or in combination with each other, preferably 0.1 to 3 in total with respect to the total amount of the ultraviolet-curable compounding components in the composition.
0% by weight, particularly preferably 0.5 to 25% by weight is blended.

<C. About diluent> As a diluent,
The photopolymerizable monomer or organic solvent can be used alone or in combination. Examples of the photopolymerizable monomer include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, N-vinylpyrrolidone, acryloylmorpholine, methoxytetraethylene glycol acrylate, methoxy polyethylene glycol acrylate, polyethylene glycol diacrylate,
N, N-dimethylacrylamide, N-methylolacrylamide, N, N-dimethylaminopropylacrylamide, N, N-dimethylaminoethyl acrylate,
Water-soluble monomers such as N, N-dimethylaminopropyl acrylate, melamine acrylate, or each methacrylate corresponding to the above acrylates, and diethylene glycol diacrylate, triethylene glycol diacrylate, propylene glycol diacrylate, tripropylene glycol diacrylate, phenoxyethyl Acrylate, tetrahydrofurfuryl acrylate, cyclohexyl acrylate, trimethylolpropane diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, isobonyl acrylate, cyclopenta Nil (mono Is di) acrylate, cyclopentenyl (mono or di) acrylate, or each methacrylate corresponding to the above acrylate and mono-, di-, tri- or higher polyesters of polybasic acid and hydroxyalkyl (meth) acrylate, etc. Of water-insoluble monomers, and epoxy acrylates such as bisphenol A type epoxy acrylate, phenol novolac type epoxy acrylate, and cresol novolac type epoxy acrylate (these epoxy acrylates are compounds having at least two isocyanate groups in the molecule or polybasic acid anhydride). (It may be partially crosslinked with materials etc.)
And high molecular weight acrylate monomers such as polyester acrylate and urethane acrylate. The above water-soluble monomers, water-insoluble monomers, high molecular weight acrylate monomers and the like can be used alone or in appropriate combination with each other.

Examples of the organic solvent include ethanol, propanol, isopropanol, butanol, isobutanol, 2-butanol, hexanol,
Linear, branched, secondary or polyhydric alcohols such as ethylene glycol, ketones such as methyl ethyl ketone and cyclohexanone, aromatic hydrocarbons such as toluene and xylene, and cellosolves such as cellosolve and butyl cellosolve, and carbi. Carbitols such as toll and butyl carbitol, and propylene glycol alkyl ethers such as propylene glycol methyl ether,
And polypropylene glycol alkyl ethers such as dipropylene glycol methyl ether, and ethyl acetate, butyl acetate, cellosolve acetate, butyl cellosolve acetate, butyl carbitol acetate, acetic acid esters such as propylene glycol monomethyl ether acetate, and dialkyl glycol ethers. Can be mentioned.

The photopolymerizable monomer such as the water-soluble monomer, the water-insoluble monomer and the high molecular weight acrylate monomer is prepared by diluting the polymer component and the like to make it easy to apply and adjusting the acid value to improve the photopolymerizability. give. Further, the above organic solvent dissolves and dilutes the polymer component and the like to make it applicable as a liquid, and also forms a film by drying. The diluent is
Although it depends on the coating method, it is preferable to mix it alone or as a mixture of two or more kinds in the range of 10 to 95% by weight based on the total amount of the photosensitive resin composition.

<D. Thermosetting Component> The thermosetting component is added for the purpose of improving the crosslink density of the resist and blocking the carboxyl groups derived from the ultraviolet curable resin. Examples of the thermosetting component include a thermosetting epoxy compound, and tolylene diisocyanate blocked with caprolactam, oxime, malonic acid ester, etc., morpholine diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate-based blocked isocyanate, and n-. Butylated melamine resin,
Examples thereof include amino resins such as isobutylated melamine resin, butylated urea resin, butylated melamine urea co-condensed resin, and benzoguanamine-based co-condensed resin.

Of these, thermosetting epoxy compounds are particularly preferable. Examples of the thermosetting epoxy compound include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, N-glycidyl type epoxy resin or alicyclic epoxy resin (for example, Daicel Chemical Industries, Ltd.). Manufactured by "EHPE-3150"), "YX-
4000 "(Epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd.),
Examples of the hydrogenated bisphenol A type epoxy resin and triglycidyl isocyanurate include triglycidyl isocyanurate, “YX-4000”, and cresol novolac type epoxy resin.

In addition to the above components, the photosensitive resin composition according to the present invention contains, for example, an ultraviolet-curable epoxy acrylate (for example, bisphenol A type, phenol novolac type, cresol novolac, alicyclic epoxy resin and (meth) acryl). An acid added thereto}, or those to which a saturated or unsaturated polybasic acid anhydride such as maleic anhydride, succinic anhydride, itaconic anhydride, phthalic anhydride or tetrahydrophthalic anhydride is further added, and styrene −
Copolymers of ethylenically unsaturated compounds such as (meth) acrylic acid- (meth) acrylic acid ester copolymers, or ultraviolet curing obtained by reacting these with ethylenically unsaturated monomers having an epoxy group -Curable polymer, UV-curable polymer obtained by adding (meth) acrylic acid to a vinyl copolymer having an epoxy group-containing ethylenically unsaturated monomer as one of the monomer units, other styrene-maleic acid resin, diallyl A polymer compound such as a phthalate resin, a phenoxy resin, a melamine resin, a urethane resin, or a fluororesin can be added.

If necessary, the photosensitive resin composition may further contain an epoxy such as an imidazole derivative, a polyamine, a guanamine, a tertiary amine, a quaternary ammonium salt, a polyphenol or a polybasic acid anhydride. Resin curing agents and curing accelerators, barium sulfate, silicon oxide,
Talc, clay, fillers and colorants such as calcium carbonate, and silicone and acrylate copolymers, leveling agents such as fluorochemical surfactants, and adhesion promoters such as silane coupling agents, thixotropic agents such as Aerosil, And various additives such as polymerization inhibitors such as hydroquinone, hydroquinone monomethyl ether, pyrogallol, tert-butyl catechol, and phenothiazine, antihalation agents, flame retardants, defoaming agents, antioxidants, and interfaces for improving dispersion stability. An activator or a polymer dispersant may be added.

The photosensitive resin composition according to the present invention is prepared by a known kneading method using a three-roll mill, a ball mill, a sand mill, etc., for the respective components and additives. Also,
A part of the above-mentioned components A to D, for example, the components A and C, are mixed and dispersed in advance, and the remaining components are mixed so as to finally become the photosensitive resin composition of the present invention at the time of use. You may take the method of preparing.

The photosensitive resin composition according to the present invention can be used not only as a solder resist ink but also as an etching resist by not applying a post-curing treatment by heat. Further, among the compounding components of the above-mentioned photosensitive resin composition, those excluding thermosetting components such as thermosetting epoxy compounds can also be suitably used to some extent as a solder resist ink, if necessary, and further etched. It can also be used as a resist ink. In addition, the photosensitive resin composition according to the present invention or the compounding ingredients thereof excluding the thermosetting component are used for forming a color filter protective film, for example, organic compounds such as azo lake type, insoluble azo type and phthalocyanine type. Pigments,
And inorganic pigments such as milori blue, iron oxide and cobalt,
Also, by selecting an appropriate pigment or dye such as an oil-soluble dye, a basic dye or a dispersible dye as a colorant, it can be used as a composition for preparing a color filter element.

[0041]

EXAMPLES The present invention will be described below based on examples, but the present invention is not limited thereto. In addition,
All "parts" and "%" used below are on a weight basis.

[Synthesis Examples 1 to 5] In a four-necked flask equipped with a reflux condenser, a thermometer, a glass tube for nitrogen substitution and a stirrer, 70 parts of glycidyl methacrylate, 30 parts of methyl methacrylate, 100 parts of carbitol acetate, 0.2 parts of lauryl mercaptan and 3 parts of azobisisobutyronitrile were added, and the mixture was heated under a nitrogen stream and polymerized at 75 ° C. for 5 hours to obtain a 50% copolymer solution.

Hydroquinone (0.05 parts), acrylic acid (37 parts) and dimethylbenzylamine (0.2 parts) were added to the above 50% copolymer solution, and the addition reaction was carried out at 100 ° C. for 24 hours, followed by tetrahydrophthalic anhydride (45). And 79 parts of carbitol acetate were added and reacted at 100 ° C. for 3 hours to give a weight average molecular weight of 26,000 as shown in Table 1.
As a synthesis example 1, a 50% UV curable resin solution (A-1) having an ethylenically unsaturated group content of 2.82 and an acid value of 91 was obtained. Then, by the same method as above,
As shown in Table 1, UV curable resin solutions (A-2) to (A-5) were obtained as Synthesis Examples 2 to 5, respectively. The weight average molecular weight shall be defined as follows.

[Method for defining molecular weight] All molecular weights are GP
It is defined by the weight average molecular weight measured by C.
The measurement conditions are as follows. (Measurement conditions) GPC measurement device: Showa Denko's SHODEX SYS
TEM 11 column: SHODEX KF-800P, KF
-005, KF-003, KF-001 four serially-transferred layer: THF flow rate: 1 ml / min Column temperature: 45 ° C Detector: RI conversion: Polystyrene

Reference Examples 1 to 4 In a four-necked flask equipped with a reflux condenser, a thermometer, a glass tube for nitrogen substitution, and a stirrer, 50 parts of glycidyl methacrylate, 50 parts of methyl methacrylate, 100 parts of carbitol acetate, 2 parts of azobisisobutyronitrile was added, and the mixture was heated under a nitrogen stream and polymerized at 75 ° C. for 5 hours to obtain a 50% copolymer solution.

Hydroquinone (0.05 parts), acrylic acid (26 parts) and dimethylbenzylamine (0.2 parts) were added to the above 50% copolymer solution, and addition reaction was carried out at 100 ° C. for 24 hours, followed by tetrahydrophthalic anhydride (10). 0.7 parts and carbitol acetate 51 parts were added and reacted at 100 ° C. for 3 hours to give a weight average molecular weight of 3500 as shown in Table 1.
0, content of ethylenically unsaturated group 2.36 and acid value 65
50% UV curable resin solution (B-
1) was obtained as Reference Example 1. By the same method as above,
As shown in Table 1, UV curable resin solutions (B-2) to (B-4) were obtained as Reference Examples 2 to 4, respectively.

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[Table 1]

(Note 1) In Table 1, the content of the ethylenically unsaturated group is represented by the number of moles of the ethylenically unsaturated group contained in 1 kg of the ultraviolet curable resin.

[Reference Example 5] 214 parts of Epiclon N-680 (cresol novolac type epoxy resin, epoxy equivalent 214 manufactured by Dainippon Ink and Chemicals, Inc.) was dissolved by heating in 60 parts of carbitol acetate, followed by acryl with stirring. 74 parts of acid, 0.1 part of hydroquinone and 1.4 parts of benzyldimethylamine were added and reacted at 90 to 100 ° C. for 24 hours by a conventional method. Further, 76 parts of tetrahydrophthalic anhydride was added to the reaction product, and the mixture was reacted at 100 ° C. for about 3 hours with stirring, and then 137 parts of carbitol acetate was added and stirred to obtain 50% UV curable resin as Reference Example 5. A solution (B-5) was obtained.

[Reference Example 6] 214 parts of Epicron N-680 (cresol novolac type epoxy resin manufactured by Dainippon Ink and Chemicals, Inc., epoxy equivalent 214) was dissolved in 60 parts of carbitol acetate by heating, and acrylic was added with stirring. 74 parts of acid, 0.1 part of hydroquinone and 0.7 part of benzyldimethylamine were added, and 90-100 by a conventional method.
The reaction was carried out at ℃ for 24 hours. 60 parts of carbitol acetate and 35 parts of butyl cellosolve were added to this reaction solution, and the mixture was stirred and then cooled to obtain 50% epoxy acrylate solution (C-1) as Reference Example 6.

Reference Example 7 In a four-necked flask equipped with a reflux condenser, a thermometer, a glass tube for nitrogen substitution, and a stirrer, 65 parts of glycidyl methacrylate, 35 parts of methyl methacrylate, 0.2 part of lauryl mercaptan, and carvi 100 parts of tall acetate and 3 parts of azobisisobutyronitrile were added, and the mixture was heated under a nitrogen stream and heated at 75 ° C for 5 hours.
Polymerization was carried out for a time to obtain a 50% copolymer solution.

Hydroquinone (0.05 parts), acrylic acid (34 parts) and dimethylbenzylamine (0.2 parts) were added to the above 50% copolymer solution, and the addition reaction was carried out at 100 ° C. for 24 hours, followed by reaction at 100 ° C. for 3 hours. Then, 34 parts of carbitol acetate was added and stirred to obtain a 50% resin solution (C-2) having a weight average molecular weight of 22,000 as Reference Example 7.

[Examples 1 to 7 and Comparative Examples 1 to 7] Comparison of the compositions shown in Table 2 with Examples 1 to 7 and Table 3 using the resin solutions of the above-mentioned synthesis examples and reference examples. The respective components of Examples 1 to 7 were kneaded with a three-stage roll to obtain a diluted alkaline developing type photosensitive resin composition.

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[Table 2]

(Note 2) In Table 2, TEPIC-S is an epoxy resin (epoxy equivalent 100) manufactured by Nissan Chemical Industries. (Note 3) In Table 2, Irgacure 907 is a photopolymerization initiator manufactured by Ciba Geigy. (Note 4) In Table 2, Kayacure ITX is a photopolymerization initiator manufactured by Nippon Kayaku Co., Ltd. (Note 5) In Table 2, Modaflow is a leveling agent manufactured by Monsanto. (Note 6) In Table 2, Swazol 1500 is an aromatic solvent manufactured by Maruzen Petrochemical Co., Ltd.

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[Table 3]

[Evaluation of Performance of Resin Composition] Performance evaluation of the photosensitive resin compositions of Examples 1 to 7 is shown in Table 4, and Comparative Examples 1 to
Table 5 shows the performance evaluation of the photosensitive resin composition of No. 7. The test items and evaluation method for the above performance evaluation are as follows.

-Surface Adhesiveness- Each photosensitive resin composition is applied by screen printing on the entire surface of a copper clad laminate made of a glass epoxy substrate of 35 μm copper foil, and dried at 70 ° C. to evaporate the solvent. 10,
Precure was performed under each of the drying conditions of 20, 30, 45, and 60 minutes to prepare five types of test pieces having a dry coating film with a film thickness of 20 μm for each composition. After that, ORC
Apply a mask with a pattern drawn with HMW201GX (Oak Seisakusho's vacuum pressure contact type double-sided exposure machine) directly to the coating surface to bring it into vacuum contact, irradiate it with 150 mj / cm ² of ultraviolet rays, and then under each drying condition The degree of sticking when removing was observed according to the following criteria. X: It was difficult to remove the mask, and the mask pattern was damaged when it was forcibly peeled off. (Triangle | delta): After the mask was removed, the sticking mark of the mask was recognized on the dry coating film. ◯: The mask could be easily removed, and there was no sticking mark.

-Precure time permissible range-Each photosensitive resin composition is applied by screen printing on the entire surface of a copper clad laminate made of a glass epoxy base material of 35 μm copper foil, and dried at 70 ° C. to volatilize the solvent. Time 10,
Six kinds of test pieces having a dry coating film with a film thickness of 20 μ, which were pre-cured under respective drying conditions of 20, 30, 45, 60 and 80 minutes, were prepared for each composition. After that, a patterned mask is directly applied to the surface of the coating film to bring it into intimate contact, and the ultraviolet rays of the optimum exposure amount for each photosensitive resin composition are irradiated, and then developed with a 1% sodium carbonate aqueous solution as a developing solution. The developability and the pattern formation state were observed according to the following criteria. X: The unexposed area was also difficult to remove by development and pattern formation was impossible. Δ: Development took a long time even in the unexposed area, and it was impossible to form a pattern in a fine pattern area. ◯: The coating film in the unexposed area was easily removed, and a sharp pattern could be obtained.

-Residual Step Stage- Each photosensitive resin composition is applied by screen printing on the entire surface of a copper clad laminate made of a glass epoxy substrate of copper foil 35μ, and dried at 70 ° C for volatilizing the solvent. Precure was performed for 30 minutes, and a test piece having a dry coating film with a film thickness of 20 μ was prepared for each composition. Then O
Step tablet PHOTEC21 with RC HMW201GX (Oak Seisakusho, vacuum contact type double-sided exposure machine)
Apply a step (Hitachi Chemical Co., Ltd. mask for exposure test) directly to the coating film, make it adhere under reduced pressure, irradiate with ultraviolet rays of 50 and 150 mj / cm ² respectively, and then develop with 1% sodium carbonate aqueous solution as a developing solution. Thus, the number of remaining steps after development was determined and used as a guide for exposure sensitivity.

[Evaluation of Performance of Printed Circuit Board on which Solder Resist is Finally Formed by Resin Composition] In order to confirm the performance of each photosensitive resin composition as a solder resist ink, a glass epoxy group of copper foil 35 μm is used. The copper clad laminate made of material and the printed wiring board which has been previously etched to form a pattern are applied by screen printing and precured at 70 ° C. for 20 minutes to evaporate the solvent. A 20μ dry coating was obtained. Then, a mask with a pattern is directly applied to the coating film surface, the ultraviolet rays of the optimum exposure amount in each photosensitive resin composition are irradiated, and then the pattern is developed by developing a 1% sodium carbonate aqueous solution as a developing solution. After being formed, it was further heated and cured at 150 ° C. for 30 minutes to prepare a test piece of a printed circuit board for each of the photosensitive resin compositions of Examples and Comparative Examples.

Table 4 shows the performance evaluation of the test pieces of Examples 1 to 7, and Table 5 shows the performance evaluation of the test pieces of Comparative Examples 1 to 7. The test items and evaluation method for the above performance evaluation are as follows.

-Resolution- The state of formation of the pattern formed by the mask pattern composed of concentric circles having both the line width and the line spacing of 40 μm was observed according to the following criteria. X: No pattern was formed. Δ: Although the pattern was formed for the time being, part of the pattern was missing. ◯: A sharp pattern could be obtained.

-Pencil Hardness- It was evaluated by a conventional method using Mitsubishi High Uni (manufactured by Mitsubishi Pencil Co., Ltd.).

-Solder heat resistance (surface whitening and adhesion) -LONCO 3355-11 (water-soluble flux manufactured by London Chemical Co., Ltd.) was used as a flux, the test piece was first coated with the flux, and then molten solder at 260 ° C. After soaking in a bath for 10 seconds and washing with water, the degree of surface whitening was observed according to the following criteria. The test piece after washing with water was subjected to a cellophane tape peeling test (JIS D0202) by cross-cut, and the change in adhesion state was observed according to the following criteria. (Evaluation of surface whitening) x: Remarkably whitened. B: Slight whitening was observed. ◯: No abnormality occurred. (Evaluation of Adhesion) X: Blistering or peeling of the resist occurred without a peeling test. Δ: Partial peeling occurred in the cross-cut portion during tape peeling. ◯: Peeling of the cross cut portion did not occur.

-Other Tests-Evaluation methods for tests such as "surface gloss", "solvent resistance", "acid resistance", gold plating resistance "and" electrostatic resistance "were based on ordinary methods.

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[Table 4]

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[Table 5]

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As described above, the superiority of the photosensitive resin composition according to the present invention is that, in terms of workability, the allowable range of precure time is wider and the exposure width is wider than that of the conventional one. It has a large sensitivity and is excellent in sensitivity, so that it is not necessary to set strict working conditions, and the coating film has no tackiness even with a short precure time, so that the working time can be significantly shortened. Further, the photosensitive resin composition according to the present invention is excellent in dispersion stability of itself and can endure long-term storage. Furthermore, the photosensitive resin composition according to the present invention gives an excellent coating film, and when this is used as a resist ink, superiority in physical properties of the formed resist is excellent chemical resistance even in a short exposure time, In addition to exhibiting solvent resistance, gold plating resistance, etc., it has extremely excellent solder heat resistance especially when formed as a solder resist. Due to the above characteristics, the photosensitive resin composition according to the present invention makes it possible to manufacture a high-quality printed circuit board with high productivity.

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Claims (7)

[Claims] 1. A. To a polymer composed of (a) 60 to 100 mol% of glycidyl (meth) acrylate and (b) 0 to 40 mol% of another ethylenically unsaturated monomer copolymerizable therewith, 1 epoxy of the polymer is added. 0.7 to 1.
UV curable resin having a weight average molecular weight of 6000 to 30000, obtained by reacting 2 chemical equivalents of (meth) acrylic acid and a saturated or unsaturated polybasic acid anhydride, B. A photopolymerization initiator, C.I. Diluent and D.I. A photosensitive resin composition containing a thermosetting component, which can be developed with a dilute aqueous alkali solution. 2. D. The photosensitive resin composition according to claim 1, wherein the thermosetting component comprises a thermosetting epoxy compound. 3. A coating film formed on a substrate using the photosensitive resin composition according to claim 1. 4. A resist ink for producing a printed circuit board, which comprises the photosensitive resin composition according to claim 1. 5. A resist formed on a substrate using the resist ink according to claim 4. 6. A solder resist formed on a substrate using the resist ink according to claim 4. 7. A printed circuit board manufactured using the resist ink according to claim 4.