JP2000056456A - Photopolymerizable resin composition and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a photopolymerizable composition developable by an aqueous solution of alkali and suitable for metal foil precise processing for manufacturing a printed wiring board and a metal mask by incorporating a thermoplastic polymer having carboxyl groups and a specified compound and a photopolymerization initiator each in a specified weight percentage. SOLUTION: This photopolymerizable resin composition comprises (a) 20-90 wt.% of the thermoplastic polymer having a weight average molecular weight of 20,000-500,000 having the carboxyl groups in an acid equivalent of 100-600, (b) 3-50 wt.% of the compound represented by the formula, and (c) 0.01-20 wt.% of the photopolymerization initiator. The thermoplastic polymer (a) is contained, preferably, in an amount of 40-60 weight %, and when <20 weight %, it is feared that film formability and tenting film strength and the like may be deteriorated, and when >70 weight %, it is feared that a photohardened film may be made brittle and close contact between the film and a substrate may be impaired and sufficient etching resistance and image forming performance may be not attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alkaline aqueous solution suitable for the production of printed wiring boards, the production of lead frames for mounting IC chips (hereinafter simply referred to as "lead frames"), the production of metal foils, and the like. The present invention relates to a possible photopolymerizable resin composition and a photopolymerizable resin laminate using the same.

[0002]

2. Description of the Related Art In recent years, a so-called dry film resist (hereinafter, simply referred to as DFR) having a structure in which a photopolymerizable resin layer is sandwiched between support films has been widely used for manufacturing a printed wiring board. One of the most important characteristics of photoresist in the manufacturing process of printed wiring boards is that the photoresist is not eroded by a liquid such as a plating solution or an etching solution, and the metal substrate surface covered with the photoresist is sufficiently etched. It can be protected. For example, peeling of the hardened resist that occurs during high-throw solder plating causes the plating solution to infiltrate between the hardened resist and the copper surface, so that the solder is plated not only in the circuit section, but also between the wires, a short circuit between wires, an increase in the width of the wires, and the periphery of the wires. This has led to problems such as irregularities in the shape of the part.

[0003] These problems are due to insufficient adhesion between the cured resist and the copper surface.
Research and development on adhesion promoters have been actively conducted. As a result of such research and development, for example, addition of a heterocyclic nitrogen-containing compound such as benzotriazole or benzimidazole to a photopolymerizable resin composition has been proposed.

However, when these compounds are used, although the penetration of the plating solution during high-throw solder plating is improved, the adhesion to the copper surface is not perfect, and it is extremely easy for gold plating having low current efficiency. Then, the cured resist peels off, causing serious defects such as short-circuiting between wirings and widening of wiring width. Particularly, an alkali-developable photopolymerizable resin or D
In FR, although it can withstand the gold plating solution, practical use has been difficult.

On the other hand, as a method for precision processing of a metal foil such as a lead frame and a metal mask, there are a stamping method of punching using a mold and an etching method of forming an image by a photographic method using a photopolymerizable resin and then etching. The law is roughly divided into two. However, with the recent trend of lighter, thinner and smaller semiconductor devices, and the diversification of small-quantity products, the stamping method has not been able to cope with the soaring cost of dies due to the diversification of small-quantity products and high-density wiring. Therefore, the etching method is more advantageous for miniaturization, small size, and large variety of products.

As a photopolymerizable resin used in such an etching method, a liquid resist obtained by adding a dichromate as a photosensitive group to a water-soluble polymer (PVA, casein, etc.) such as a synthetic colloid or a natural colloid has been used. Has been used. This liquid resist has a large investment in coating equipment,
There were problems such as difficulty in uniform coating, low sensitivity, and necessity of treating chromium waste liquid generated during the process. In order to solve these problems, it has recently been proposed to use DFR as a photoresist for precision processing of a metal foil substrate.

However, the conventional alkali developing type DF
R is an iron-based metal foil base material represented by 42 alloy (iron-nickel alloy), although good image formation is possible with a copper-based base metal represented by a printed wiring board. In the case of patterning using such a resist, the meandering and peeling of the hardened resist occurs during development, and the lower portion of the resist is etched during etching, which causes a problem that the yield of products is reduced. In addition, during high-temperature etching (60 ° C. or higher), peeling / floating of the cured resist occurred extremely easily due to insufficient chemical resistance as well as the adhesion of the photoresist to the substrate. As a result, serious defects such as a short circuit between image patterns and a decrease in image pattern width were caused. Particularly, in the case of an alkali-developable photopolymerizable resin or DFR that can be developed with a chemical solution such as sodium carbonate, in the case of precision processing using an iron-based metal foil base material represented by 42 alloy, infiltration of an etching solution generated during high-temperature etching. Those that can withstand have not been put to practical use.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to overcome the above-mentioned problems and to provide an alkaline alkaline solution suitable for the production of printed wiring boards, the production of lead frames for mounting IC chips, the production of metal masks, and the like. An object of the present invention is to provide a photopolymerizable resin composition that can be developed with an aqueous solution and a photopolymerizable resin laminate using the same.

[0009]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, surprisingly, the use of a photopolymerizable resin composition containing the following compounds as essential components has led to the They have found that the problem can be solved, and have completed the present invention. That is, the present application provides the following inventions. (1) (a) Carboxyl group content is 100 to 100 in acid equivalent.
600, a thermoplastic polymer having a weight average molecular weight of 20,000 to 500,000, 20 to 90% by weight, (b) 3 to 50% by weight of a compound represented by the following general formula (I), and (c) photopolymerization initiation Agent
And 0.01 to 20% by weight of the photopolymerizable resin composition.

[0010]

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The following (2) and (3) are preferred embodiments of the present invention. (2) The thermoplastic polymer of the component (a) comprises: i) at least one compound of an α, β-unsaturated carboxyl group-containing monomer having 3 to 15 carbon atoms; 15 to 35% by weight;
i) x) an alkyl (meth) acrylate in which the alkyl group has 1 to 6 carbon atoms, y) hydroxyl (meth) in which the hydroxylalkyl group has 2 to 6 carbon atoms
Acrylate, and z) a copolymer of 5 to 65% by weight of one or more compounds selected from the group consisting of a styrene-type compound represented by the following general formula (II) or a ring-substituted derivative thereof. The photopolymerizable resin composition according to the above (1).

[0012]

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(3) A photopolymerizable resin laminate comprising a support and a layer comprising the photopolymerizable resin composition as described in (1) or (2) above. Here, the weight% of each component indicates the ratio of each component contained in the composition. Hereinafter, each component constituting the photopolymerizable resin composition of the present invention will be described in detail.

The photopolymerizable resin composition for a dry film of the present invention can be obtained by mixing the components according to a conventional method. First, the thermoplastic polymer for a binder (a), which is an essential component constituting the photopolymerizable resin composition of the present invention, accounts for 20 to 90% by weight, preferably 40 to 60% by weight in the photopolymerizable resin material. Contained. If the content is less than 20% by weight, the film formability is deteriorated, the strength of the tenting film is reduced, and the cold flow phenomenon (the phenomenon that the photopolymerizable resin layer protrudes from the end face when the DFR is stored in a roll state). ). On the other hand, if it exceeds 70% by weight, the photocured film becomes brittle, the adhesion to the substrate is impaired, and sufficient etching resistance and image forming properties cannot be obtained.

Further, a thermoplastic polymer (a) for a binder
Has a weight average molecular weight of 10,000 to 500,000, preferably 2 to 500,000.
It is desirable to use the one of 10,000 to 250,000. Those having a weight average molecular weight of less than 10,000 may cause a cold flow phenomenon.
On the other hand, when the weight average molecular weight exceeds 500,000, the alkali developability of the unexposed portion is lowered to make development impossible, or the development time becomes extremely long, causing deterioration in image formability.

In particular, (a) as a component of the carboxyl group-containing thermoplastic polymer, i) at least one compound of an α, β-unsaturated carboxyl group-containing monomer having 3 to 15 carbon atoms, 15 to 35% by weight Ii) an alkyl (meth) acrylate in which the x) alkyl group has 1 to 6 carbon atoms, y) a hydroxyl (meth) acrylate in which the hydroxylalkyl group has 2 to 6 carbon atoms, and z) A thermoplastic polymer for a binder, obtained by copolymerizing 5 to 65% by weight of one or more compounds selected from the group consisting of a styrene-type compound represented by the general formula (II) or a ring-substituted derivative thereof, 20 to 90% by weight By using%, more favorable characteristics such as plating resistance, etching resistance, adhesion, and resolution can be obtained.

In order to obtain such a thermoplastic polymer for a binder, an appropriate amount of the following two polymerizable substance groups is copolymerized. The first polymerizable substance is 3
Consisting of one or more compounds of α, β-unsaturated carboxyl group-containing monomers having up to 15 carbon atoms. As the unsaturated carboxyl group-containing monomer, preferably acrylic acid and methacrylic acid, other cinnamic acid, crotonic acid, sorbic acid, itaconic acid, propiolic acid,
Maleic acid and fumaric acid are mentioned. Also, these half esters or anhydrides can be used. It is desirable that the first polymerizable substance is used in an amount of 15 to 35% by weight, preferably 18 to 30% by weight in the copolymer. If it is less than 15% by weight, development with an aqueous alkali solution is not
Alternatively, the development time is too long, resulting in a decrease in image forming properties such as resolution and adhesion. When the content exceeds 35% by weight, the development time becomes extremely short, and development control is complicated to obtain a high-resolution pattern. , And the water resistance and chemical resistance of the cured portion also decrease.

The second polymerizable substance is: x) an alkyl (meth) acrylate having an alkyl group having 1 to 6 carbon atoms;
y) a hydroxyl (meth) acrylate having a hydroxylalkyl group having 2 to 6 carbon atoms, and z) at least one member selected from the group consisting of a styrene-type compound represented by the general formula (II) or a ring-substituted derivative thereof. Consists of

Examples of the alkyl group having 1 to 6 carbon atoms include alkyl (meth) acrylate, and examples of the hydroxyl (meth) acrylate having a hydroxylalkyl group having 2 to 6 carbon atoms include methyl (meth) acrylate. ) Acrylate, ethyl (meth) acrylate,
n-propyl (meth) acrylate, iso-propyl (meth) acrylate, n-butyl (meth) acrylate, sec-butyl (meth) acrylate, tert-
Butyl (meth) acrylate, 2-hydroxylethyl (meth) acrylate, 2-hydroxylpropyl (meth) acrylate and the like can be mentioned. These polymerizable substances are used in an amount of 5 to 65% by weight, preferably 20 to 55% by weight in the copolymer. If the amount is less than 5% by weight, a sufficiently flexible dry film resist cannot be obtained, and the adhesion to the substrate and the ability to embed the resist resin into the irregularities on the surface of the substrate become insufficient, and the etching resistance decreases. 65
If the amount exceeds 10% by weight, on the contrary, the resist resin is too soft and causes a cold flow phenomenon when a dry fill resist is used.

In the styrene type compound represented by the general formula (II), even if the benzene ring is substituted with a functional group such as nitro, nitrile, alkoxyl, acyl, sulfone, hydroxyl, or halogen. Good and preferably a single alkyl group such as hydrogen, a methyl group or a t-butyl group. One to five of these substituents may be present on the benzene ring.

Examples of the styrene type compound represented by the general formula (II) include styrene, α-methylstyrene, P-methylstyrene, P-chlorostyrene and the like, and styrene and P-methylstyrene are particularly preferred. is there. These styrene type compounds are used in an amount of 5 to 65% by weight, preferably 10 to 50% by weight in the copolymer. If it is less than 5% by weight, sufficient chemical resistance cannot be obtained, and if it exceeds 65% by weight, the dry film resist becomes too hard, and the flexibility of the resist film may be impaired.

The photopolymerizable resin composition of the present invention is prepared by blending a compound (b) represented by the above-mentioned general formula (I) in a prescribed amount to obtain an iron-based metal foil represented by gold plating resistance and 42 alloy. The etching resistance in precision processing using a base material is dramatically improved. Examples of the compound represented by the general formula (I) include tetrahydrofurfuryl acrylate, tetrahydrofurfuryl methacrylate, acryloyl morphonide, methacryloyl morphonide, cyclohexene oxide acrylate, cyclohexene oxide methacrylate, and cyclohexene oxide succinate. Acid-modified acrylic acid esters, cyclohexene oxide succinic acid-modified acrylic acid esters and the like can be mentioned. Particularly preferred examples include cyclohexene oxide acrylate and cyclohexene oxide succinic acid-modified acrylate. These compounds may be used alone or in combination of two or more.

The amount of the compound represented by formula (I) contained in the photopolymerizable resin composition of the present invention is 3 to 50% by weight.
It is. When the amount of the compound is 50% by weight or more, the sensitivity of the photopolymerizable composition is lowered, a sufficient photocuring reaction is not obtained, and a resist line easily flows in an alkali developing solution, which hinders the formation of a circuit pattern. There is fear. If the content is less than 3% by weight, the effect of adding the compound may not be obtained, and sufficient etching resistance and plating resistance may not be exhibited.

In the present invention, it is a preferred embodiment to use a photopolymerizable vinyl monomer in combination. Examples of such a photopolymerizable vinyl monomer include 1,6-hexanediol di (meth) acrylate, 1,4-cyclohexanediol di (meth) acrylate, polypropylene glycol di (meth) acrylate, and polyethylene glycol di ( Polyoxyalkylene glycol di (meth) acrylates such as meth) acrylate, polyoxyethylene polyoxypropylene glycol di (meth) acrylate, 2-di (p-hydroxyphenyl)
Propane di (meth) acrylate, glycerol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, polyoxypropyltrimethylolpropane tri (meth) acrylate, polyoxyethyltrimethylolpropane triacrylate, dipentaerythritol penta (meth) Acrylate, trimethylolpropane triglycidyl ether tri (meth)
Acrylates, bisphenol A diglycidyl ether di (meth) acrylate, 2,2-bis (4-methacryloxypentaethoxyphenyl) propane, polyfunctional (meth) acrylates containing urethane groups and the like are available. Particularly preferred examples of these photopolymerizable monomers include the following general formula (III) or general formula (IV)
The compound shown by these is mentioned.

[0025]

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[0026]

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These monomers may be used alone or in combination of two or more. The preferred amount is 5 to 60.
%, More preferably 30 to 55% by weight. If this amount is less than 5% by weight, the sensitivity and film strength are not sufficient, and if this amount exceeds 60% by weight, cold flow is remarkably generated, which is not preferable. The photopolymerizable resin composition of the present invention contains the photopolymerization initiator of the component (c) as an essential component. As such a photopolymerization initiator, any known compound that is activated by various kinds of actinic rays, for example, ultraviolet rays and starts polymerization is used.
Such compounds include, for example, 2-ethylanthraquinone, octaethylanthraquinone, 1,2-benzanthraquinone, 2,3-benzanthraquinone,
-Phenylanthraquinone, 2,3-diphenylanthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 2-methylanthraquinone, 1,4-naphthoquinone, 9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone Quinones such as 2,9,10-phenanthraquinone, 2-methyl-1,4-naphthoquinone, 2,3-dimethylanthraquinone and 3-chloro-2-methylanthraquinone; benzophenone Michler's ketone [4,4'- Bis (dimethylamino) benzophenone], aromatic ketones such as 4,4'-bis (diethylamino) benzophenone, benzoin ethers such as benzoin, benzoin ethyl ether, benzoin phenyl ether, methyl benzoin and ethyl benzoin, benzyl dimethyl ketone Dialkyl ketals such as tar and benzyl diethyl ketal; biimidazole compounds such as 2- (o-chlorophenyl) -4,5-diphenylimidazolyl dimer; acridines such as 9-phenylacridine; diethylthioxanthone and chlorothioxanthone; Thioxanthones, dialkylaminobenzoic acid esters such as ethyl dimethylaminobenzoate, 1-
Phenyl-1,2-propanedione-2-o-benzoyloxime, 1-phenyl-1,2-propanedione-
Oxime esters such as 2- (o-ethoxycarbonyl) oxime and the like. These photopolymerization initiators may be used alone or in combination.

Particularly preferred examples of the photopolymerization initiator include:
2- (o-chlorophenyl) -4,5-diphenylimidazolyl dimer, 2- (o-chlorophenyl) -4,5
Di (m-methoxyphenyl) imidazole dimer, 2
-(O-fluorophenyl) -4,5-diphenylimidazole dimer, and the like. Also, 2- (o-chlorophenyl) -4,5-diphenylimidazolyl dimer and thioxanthones such as diethylthioxanthone and chlorothioxanthone; dialkylaminobenzoic acid esters such as ethyl dimethylaminobenzoate; benzophenone; A combination of -bis (dimethylamino) benzophenone and 4,4'-bis (diethylamino) benzophenone can also be selected.

The amount of the photopolymerization initiator contained in the photopolymerizable resin composition of the present invention is from 0.01 to 20% by weight. When the amount of the photopolymerization initiator is 20% by weight or more, the active absorptivity of the photopolymerizable composition becomes high, and when used as a photopolymerizable resin laminate, the bottom of the photopolymerizable resin layer is insufficiently cured by polymerization. become. If the amount is less than 0.01% by weight, sufficient sensitivity cannot be obtained.

The photopolymerizable resin composition of the present invention comprises a dye,
A coloring substance such as a pigment may be contained. Examples of such coloring substances include fuchsin, phthalocyanine green, auramine base, chalcoxide green S, paramagenta, crystal violet, methyl orange, nile blue 2B, Victoria blue, malachite green, basic blue 20, diamond green and the like. Can be

Further, the photopolymerizable resin composition of the present invention includes:
A coloring dye which develops color by light irradiation may be contained. Examples of such a coloring dye include tris (4-dimethylamino-2-methylphenyl) methane [leuco crystal violet], tris (4-dimethylamino-2-methylphenyl) methane [leucomalachite green] and the like. No. Further, a combination of a biimidazole compound and a leuco dye or a combination of a triazine compound and a leuco dye is useful. Such triazine compounds include 2,4,6-tris (trichloromethyl) -s-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl)
-S-triazine.

The photopolymerizable resin composition of the present invention is applied as a liquid resist on a metal substrate surface, for example, an iron-based alloy such as copper, copper-based alloy, nickel, chromium, iron, and stainless steel, and dried. It is preferable to use the photopolymerizable resin film coated with a protective film, or to use it as a photopolymerizable resin film composed of the photopolymerizable resin layer and a support layer supporting the photopolymerizable resin layer. As the protective film and the support layer, a transparent film that transmits active light is desirable.

Examples of the support layer that transmits active light include polyethylene terephthalate film, polyvinyl alcohol film, polyvinyl chloride film, vinyl chloride copolymer film, polyvinylidene chloride film, vinylidene chloride copolymer film, and polymethyl methacrylate copolymer. Examples include a coalesced film, a polystyrene film, a polyacrylonitrile film, a styrene copolymer film, a polyamide film, and a cellulose derivative film.
These films may be stretched if necessary. A thinner thickness is advantageous in terms of image formability and economy, but it is 10 to 30 μm in order to maintain strength.
Is common.

A protective layer is laminated on the surface opposite to the photopolymerizable resin layer laminated with the support layer, if necessary. The important property of this protective layer is in the adhesion to the photopolymerizable resin layer,
It is required that the protective layer is sufficiently smaller than the support layer, so that it can be easily peeled off. Examples of the material for such a protective layer include a polyethylene film and a polypropylene film. Also, Japanese Patent Application Laid-Open No. 59-2024
A film having excellent releasability shown in JP-A-57-57 can also be used.

Although the thickness of the photopolymerizable resin layer varies depending on the application, it is 5 mm for producing a printed wiring board and a metal processing board.
１００100 μm, preferably 10-80 μm, and the thinner the thickness, the higher the resolution. Also, the film thickness increases as the thickness increases. Next, a printed wiring board and a metal foil precision processing step using the photopolymerizable resin laminate of the present invention will be briefly described. First, use a laminator and if there is a protective layer,
After peeling off the protective layer, the photopolymerizable resin layer is laminated on the metal surface by thermocompression bonding. The heating temperature at this time is generally 40 to 1
60 ° C. Further, by performing the pressure bonding twice or more, the adhesion and the etching resistance are improved. At this time, a two-stage laminator provided with two rolls may be used for the crimping, or a plurality of times may be repeated to pass through the rolls and crimped. No.). Next, if necessary, the support layer is peeled off, and image exposure is performed with actinic light through a mask film. Next, if there is a support layer on the photopolymerizable resin layer after exposure, the support layer is removed if necessary, and then the unexposed portion is developed and removed using a developing solution of an alkaline aqueous solution. As the aqueous alkaline solution, an aqueous solution of sodium carbonate, potassium carbonate, or the like is used. These are selected in accordance with the properties of the photopolymerizable resin layer, but 0.5%
Aqueous ~ 3% aqueous sodium carbonate is common.

The substrate thus obtained can be subjected to a heating step at 100 to 300 ° C. in some cases. Through such a heating step, the etching resistance can be further improved. Next, a metal image pattern is formed on the metal surface exposed by development using a known method such as an etching method. Thereafter, the cured resist image is stripped with an alkaline aqueous solution that is generally stronger than the alkaline aqueous solution used for development. There is no particular limitation on the alkaline aqueous solution for stripping, but aqueous solutions of sodium hydroxide and potassium hydroxide are generally used. Further, it is possible to add a small amount of a water-soluble solvent to a developer or a stripper.

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments. <Synthesis Example 1> 300 g of methyl ethyl ketone and 270 methyl methacrylate were placed in a 1000 cc four-necked flask equipped with a nitrogen inlet, a stirring blade, and a thermometer under a nitrogen atmosphere.
Parts by weight, 90 parts by weight of methacrylic acid and 40 parts by weight of n-butyl acrylate were added, and the temperature of the hot water bath was raised to 70 ° C. while stirring. Next, 2 g of azobisisobutyronitrile was added to 3 g
Dissolved and added in 0 g of methyl ethyl ketone, and polymerized for 6 hours. Add 3 g of azobisisobutyronitrile to 30
g of methyl ethyl ketone, and the mixture was added in two portions every one hour. Then, the temperature in the flask was raised to the boiling point of the solvent, and polymerization was performed at that temperature for 2 hours. After the completion of the polymerization, 240 g of methyl ethyl ketone was added, and the polymerization reaction product was taken out of the flask to obtain a binder resin solution A (weight average molecular weight 92,000, solid content 42%).

<Synthesis Example 2> 270 parts by weight of methyl methacrylate, 90 parts by weight of methacrylic acid, 40 parts by weight of n-butyl acrylate were added, and then 3.2 g of azobisisobutyronitrile was dissolved in 30 g of methyl ethyl ketone. Binder resin solution B in the same manner as in Synthesis Example 1 except that it is added
(Weight average molecular weight: 59,000, solid content: 41%).

<Synthesis Example 3> A binder resin solution C (weight average molecular weight of 4 parts by weight) was prepared in the same manner as in Synthesis Example 1 except that methyl methacrylate was 160 parts by weight, methacrylic acid was 100 parts by weight, styrene was 100 parts by weight, and acrylonitrile was 40 parts by weight. 7
10,000, solid content 41%). <Synthesis Example 4> Binder resin solution D (weight average molecular weight 66,000) was prepared in the same manner as in Synthesis Example 1 except that 100 parts by weight of methacrylic acid, 200 parts by weight of methyl methacrylate, 60 parts by weight of styrene, and 40 parts by weight of methyl acrylate were used. , Solids 41
%).

[0040]

Examples 1 to 6 and Comparative Examples 1 to 4 The binder resins shown in Table 1 below were used as the component (a), and the components (a) to (c) and d1 to d3 were expressed in terms of the weight ratio of solids. 1, 4 parts by weight of 4,4'-diethylaminobenzophenone, 0.05 parts by weight of malachite green, 1 part by weight of leuco crystal violet and 10 parts by weight of methyl ethyl ketone A solution was obtained.

[0041]

[Table 1]

B1: cyclohexene oxide acrylate b2: cyclohexene oxide succinic acid-modified acrylate c1: benzophenone c2: 2- (o-chlorophenyl) -4,5-diphenylimidazolyl dimer c3: tribromomethylphenylsulfone d1 : Hexamethylene diisocyanate and oligopropylene glycol monomethacrylate (Nippon Oil & Fats Co., Ltd.)
D2: Nonaethylene glycol dimethacrylate d3: Trimethylolpropane triacrylate Then, this photopolymerizable resin composition solution is uniformly applied to a 20 μm-thick polyethylene terephthalate film using a bar coater. did. This was dried in a dryer at 90 ° C. for 3 minutes to obtain a photopolymerizable resin laminate having a photopolymerizable resin layer thickness of 30 μm. Then, on the surface of the photopolymerizable resin layer on which the polyethylene terephthalate film is not laminated, 3
A laminated film-1 was prepared by laminating a 0 μm polyethylene film.

The obtained laminated film-1 was coated with a thickness of 35 μm.
The photopolymerizable resin laminate was laminated at 105 ° C. while peeling off the polyethylene film so that the photopolymerizable resin laminate faced the copper surface of the copper-clad laminate of m. Next, a resolution mask film (striped) was placed on the polyethylene terephthalate film side, and the solution was exposed to an ultra-high pressure mercury lamp (manufactured by Oak Works: HMW-201KB).
The photopolymerizable resin layer was exposed to light at 0 mJ / cm2. continue,
After removing the polyethylene terephthalate film, 1
A non-exposed portion was dissolved and removed by spraying an aqueous solution of 30% sodium carbonate (30 ° C.) for about 45 seconds, and the photocurable resin was patterned. Then, after performing nickel plating with a thickness of 5 μm using the patterned photocurable resin film as a plating resist, gold plating (electrolytic neutral gold plating, electroless neutral gold plating) is performed.
The operation was performed to a thickness of μm. Next, the photocurable resin film was peeled off using a 3% aqueous solution of caustic soda (temperature: 50 ° C.),
An evaluation sample was obtained.

Using the samples thus prepared, (1) sensitivity and (2) the state of penetration of the gold plating solution in Examples and Comparative Examples were evaluated as follows. (1) Sensitivity A 27-step tablet with brightness changed from transparent to black in 27 steps [manufactured by Asahi Kasei Corporation: optical density D = 0.
50 to 1.80, ΔD = 0.05], the number of steps corresponding to the time when the metal foil substrate was exposed after development was determined. This numerical value is usually desirably 10 to 14 stages. This number is 15
If the number of steps is more than the number of steps, fogging occurs and the resolution is reduced. on the other hand,
When the value is 9 steps or less, the photocuring reaction becomes insufficient and a clear pattern cannot be obtained, or the adhesion of the resist line decreases. (2) State of penetration of gold plating solution The penetration width of gold plating was measured by an optical microscope.
When the penetration width of the etching solution was less than 5 μm, it was judged as ○.

Table 2 shows the results thus determined.

[0046]

[Table 2]

[0047]

Examples 7 to 12 and Comparative Examples 5 to 8 Photopolymerizable resin composition solutions prepared according to Table 1 were mixed with a photopolymerizable layer having a thickness of 2%.
Examples 1 to 6 except that a photopolymerizable resin laminate of 0 μm was used.
In the same manner as in the above, laminated film-2 was prepared, and Examples 7 to 12 were produced. Next, the obtained laminated film-2
Was laminated on a 42-alloy base material having a thickness of 150 μm at 105 ° C. while peeling off the polyethylene film so that the photopolymerizable resin laminate faced, to produce a photopolymerizable resin laminate-2. Next, a resolution mask film (striped) was placed on the polyethylene terephthalate film side, and an ultra-high pressure mercury lamp (manufactured by Oak Works: HMW-2)
01KB) to expose the photopolymerizable resin layer at 70 mJ / cm2. Subsequently, after removing the polyethylene terephthalate film, a 1% aqueous sodium carbonate solution (30 ° C.)
Was sprayed for about 35 seconds to dissolve and remove unexposed portions, thereby patterning the photocurable resin. Then, using the patterned photocurable resin film as an etching resist, the 42 alloy base material is etched from the surface where the photocurable resin is laminated with a ferric chloride solution (50 Baume, liquid temperature 70 ° C., 5 minutes), and then 3 The photocurable resin film was peeled off using an aqueous solution of 50% caustic soda (temperature: 50 ° C.) to obtain a sample for evaluation.

Using the samples thus prepared, (1) the sensitivity and (2) the state of penetration of the etching solution in Examples and Comparative Examples were evaluated as follows. Table 3 shows the results
Shown in (1) Sensitivity A 27-step tablet with brightness changed from transparent to black in 27 steps [manufactured by Asahi Kasei Corporation: optical density D = 0.
50 to 1.80, ΔD = 0.05], the number of steps corresponding to the time when the metal foil substrate was exposed after development was determined. (2) State of Penetration of Etching Solution The penetration width of the etching solution was measured by an optical microscope. When the penetration width of the etching solution was less than 5 μm, it was judged as ○.

[0049]

[Table 3]

[0050]

Example 13 <Preparation of Lead Frame Using 42 Alloy Substrate> A photopolymerizable resin layer was prepared by using a laminated film-2 prepared in Examples 7 to 12 on a 42 alloy alloy substrate having a thickness of 150 μm. 10 so that it faces the 42 alloy base material.
Both sides were laminated at 5 ° C. Next, a negative film mask having a lead frame pattern (208 pins) is overlaid on the polyethylene terephthalate film of the photopolymerizable resin laminate so as to be vertically aligned from both sides, and both are brought into close contact with each other under vacuum, and the exposure amount is 70 mJ / cm 2. Exposure. Thereafter, the polyethylene terephthalate film was peeled and removed, and a 1% aqueous sodium carbonate solution (liquid temperature 30) was used as a developer.
C.) to form a lead frame pattern.

Next, a ferric chloride solution (47 Baume, liquid temperature 70 ° C.) was used as an etching solution, and etching was performed from both sides until the etching penetrated the substrate. Then, the photopolymerizable resin layer was removed using 3% caustic soda (liquid temperature: 50 ° C.) as a stripping solution to obtain a target lead frame. When the obtained lead frame was visually observed with an electron microscope, the adhesion between the photopolymerizable resin layer shown in Examples 7 to 12 and the 42 alloy base material was good, and the edge of the obtained lead frame pattern was obtained. The part was very sharp without erosion of the etching solution.

[0052]

Comparative Example 9 A lead frame was prepared by repeating Example 13 except that the dry film resists prepared in Comparative Examples 5 to 8 were used. Visual observation of the obtained lead frame with an electron microscope revealed that, along with the occurrence of missing / lifting of the resist line in the inner lead portion, excessive etching solution erosion from the interface between the photopolymerizable resin layer and the 42 alloy base material. Was observed.

According to the present invention, it is possible to develop with an alkaline aqueous solution which is suitable for the production of a printed wiring board, the production of a lead frame for mounting an IC chip, the production of a metal mask, and the like. A photopolymerizable resin composition having excellent adhesion and a photopolymerizable resin laminate using the same are provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 3/06 H01L 21/30 502R F-term (Reference) 2H025 AA09 AA14 AB06 AB11 AB15 AB16 AC01 AD01 BC32 BC42 BC83 BC85 BC86 CA01 CA28 CB13 CB14 CB16 CB43 CB45 CB51 CB55 FA03 FA17 FA43 FA48 4F100 AB17 AB33 AK01A AK25A AK42 AL01A AL05A AT00B BA02 CA02A EJ54 EJ91 GB41 GB43 JA07A JA20A JB14A JB16 CF10 J0101 CC02

Claims (3)

[Claims] 1. A thermoplastic polymer having (a) a carboxyl group content of an acid equivalent and a 100 weight average molecular weight of 20,000 to 500,000, 20 to 90% by weight, and (b) represented by the following general formula (I). (C) a photopolymerization initiator,
A photopolymerizable resin composition containing 0.01 to 20% by weight. Embedded image 2. The thermoplastic polymer of the component (a) comprises i) 3
At least one compound of an α, β-unsaturated carboxyl group-containing monomer having from 15 to 15 carbon atoms, from 15 to 35% by weight, and ii) an alkyl (meta) wherein the alkyl group has from 1 to 6 carbon atoms. A) an acrylate, y) a hydroxyl (meth) acrylate having a hydroxylalkyl group having 2 to 6 carbon atoms, and z) a styrene-type compound represented by the following general formula (II) or a ring-substituted derivative thereof. The photopolymerizable resin composition according to claim 1, wherein the composition is obtained by copolymerizing 5 to 65% by weight of one or more compounds. Embedded image 3. A photopolymerizable resin laminate comprising a support and a layer comprising the photopolymerizable resin composition according to claim 1 provided on a support.