KR19980049928A - Photocurable Resin Composition - Google Patents

Abstract

In order to solve the problems of the prior art in which the sensitivity and the breakdown property are poor when the photosensitive film is to maintain excellent tentability, the present invention introduces a polyfunctional monomer having excellent hardenability even at a small amount into the photocurable resin composition, resulting in excellent tentability. It is related with the photocurable resin composition which can provide the photosensitive film which has sufficient sensitivity and chemical-resistance, maintaining.

Description

[Name of invention]

Photocurable Resin Composition

Detailed description of the invention

The present invention relates to photocurable resin compositions useful as coating materials, photoresists and the like. More specifically, the present invention relates to an alkali developable photocurable resin composition having high UV sensitivity, good resolution, excellent adhesion, and excellent chemical resistance while maintaining excellent tentability.

Generally, photocurable resin compositions are used for microfabrication such as printing, wiring tubes, printed circuit boards, and metal relief phase formation.

When the photocurable resin composition is laminated on a metal surface or the like by coating or lamination, and irradiated with ultraviolet rays, the exposed portion is cured and the unexposed portion is removed by a suitable solvent to form a desired image.

The solvent is largely divided into water-soluble and water-insoluble, and water-insoluble solvents are disadvantageous in terms of working environment, environmental pollution, and manufacturing cost, and thus photocurable resin compositions that develop into water-soluble solvents are increasing.

The photocurable resin composition may be a polyfunctional monomer which is photopolymerized by light, a photoinitiator which induces radicals or radicals by light to cause photopolymerization, a polymer binder which imparts mechanical strength, tentability and adhesion of the photopolymerization composition, and a dye And stabilizers, such as adhesion promoters and thermal polymerization inhibitors. The photocurable resin composition may be used in a liquid state, or a photosensitive layer made of the photocurable resin composition may be laminated between the light transmissive polyester film and the protective film for workability and contamination prevention. In use, the protective film is peeled off and laminated by lamination on a dynamic layer plate, and irradiated with ultraviolet rays to form an image through a development process.

The polyfunctional monomer should be photopolymerized by the initiator to be resistant to the developer and to be removed from the stripper. Usually, the polyfunctional monomer uses a compound having at least one or more α, β-ethylenically unsaturated bonds. In view of photopolymerization, compounds having two or more acryloyl or methacryloyl groups in the molecule are preferable.

The photoinitiator is accompanied by the excitation of electrons by ultraviolet light and itself generates radicals or induces other compounds to generate radicals to allow the multifunctional monomers to polymerize. The photocuring rate of the composition depends greatly on the type and content of photoinitiator.

The polymer binder may be an organic polymer such as an acryl-based polymer, a styrene-based polymer, polyvinyl acetate, vinyl ethylene acetate, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, chlorinated polyethylene, chlorinated polypropylene, vinylidene chloride Polymers, polyesters, polyamides, polyurethanes, polyvinyl acetals, alkyd resins, phenolic resins, epoxy resins, cellulose acetates, nitrate screens, styrene-butylene copolymers, styrene-acrylonitrile copolymers, rubber chlorides, maleicans Vinyl copolymers of hydride, aromatic sulfonamide formaldehyde resins, and the like.

The additives include dyes, stabilizers, adhesion promoters and thermal polymerization inhibitors. For dyes, leuco-based dyes are mainly used and include methyl violet, malachide green, and crystal violet. Others are selected and added according to the purpose.

Alkaline developable dry film photoresist prepared from the photocurable composition is an alkali of arbitrary concentration and temperature after removing the protective film layer from the dry film photoresist and laminating it on a copper plate to perform ultraviolet light exposure using a photomask film or the like. An unexposed portion is removed using an aqueous solution to form a photoresist image. The process of forming the photoresist image by removing unexposed portions using an aqueous alkali solution is called development. At the time of development, the photosensitive layer of the unexposed portion is dissolved in 0.5-1.5 wt% sodium carbonate or potassium carbonate aqueous solution in the temperature range of 30 ± 5 ° C. to form an image.

The photocurable resin composition thus prepared is used for producing a dry film photoresist, which is required to have plating resistance and elasticity of the film itself. In the case of manufacturing a printed circuit board, there are a plating method and a tenting method according to a method. In the plating method, dry film resist is eroded while plating is performed on a substrate with plating solution and various additive chemicals. It should have plating resistance so that it does not peel off. In the tenting method, the dry film photoresist acts as a resist covering the hole in order to protect the hole of any size that imparts conductivity to the upper and lower surfaces of the substrate from the etching solution. The etching conditions such as FeCl ₂ , FeCl ₃ , CuCl ₂ , CuCl ₃ and ammonia persulfate are sprayed in the developing conditions under the spraying method to the aqueous solution of 0.5 to 1.5% by weight of sodium carbonate or potassium carbonate at a temperature range of 50 ± 5 ℃. The dry film blocking the hole on the substrate with respect to the etching conditions is sufficient to cope with the external stress It must be elastic.

However, the alkali developable photosensitive film prepared from the conventional photocurable resin composition has a disadvantage in that sensitivity and chemical resistance are inferior in order to maintain excellent tentability.

Therefore, in order to solve the problems of the prior art in which the sensitivity and chemical resistance of the photosensitive film as described above are solved, the present invention maintains excellent tentability by introducing a photopolymerizable polyfunctional monomer having excellent curability even at a small amount of addition into the photocurable resin composition. It is an object of the present invention to provide a photocurable resin composition capable of providing a photosensitive film having sufficient sensitivity and chemical resistance.

The present invention relates to a photocurable resin composition containing a photopolymerizable polyfunctional monomer, a photopolymerization initiator, a polymer binder, and an additive, wherein the photopolymerizable polyfunctional monomer is used as a monomer of the following structural formula (I) to (III), (III) It relates to a photocurable resin composition which is prepared by using a single monomer or a mixture of all).

Hereinafter, the present invention will be described in more detail.

The present invention relates to a photocurable resin composition containing a photopolymerizable polyfunctional monomer, a photopolymerization initiator, a polymer binder, and an additive, wherein the monomer of Formula (II) is added to the monomer of Formula (I) in an arbitrary ratio with respect to the entire photocurable resin composition. The monomer of (III) or 1 type or all are used for mixing, and it provides the curable resin composition.

The total amount of the monomer to be used is preferably added in 10 to 40% by weight based on the total amount of the photocurable resin composition. If the amount of the added photopolymerizable polyfunctional monomer is less than 10% by weight, it does not cause proper photocuring ability, and thus does not have resistance to various acid alkaline aqueous solutions and materials used during the manufacturing process of the printed circuit board, thereby reducing the ability to form a desired circuit. If it does not perform its own role and exceeds 40% by weight, there is a problem in uniformity and stability when applying by the viscous flow of the photosensitive layer, and the outflow to the outside occurs. When the resist is peeled off, peeling is not easy.

In addition, the ratio of the monomer of Formula (I) and the monomer of Formula (II), (III) used is 5-30 weight% of the monomer of Formula (I), and the monomer of Formula (II), (III) is 70- It is preferable to set it as 95 weight%.

When less than 5% by weight of the monomer of formula (I) is added, the sensitivity and chemical resistance are inferior, and when it is added more than 30% by weight, the resist film is brittle due to past photocuring, thereby weakening the tentability.

In addition to the above acrylic monomers, the present invention includes methyl acrylate, styrene, 2-phenoxymethyl acrylate, 2-phenoxyethyl acrylate, maleic acid, maleic anhydride, vinyl acetate, and the like. You may use the acrylic copolymer manufactured by the combination.

Photoinitiators, photopolymerizable monomers and other additives may be added freely without departing from the object of the present invention.

Hereinafter, the present invention will be described in detail with reference to Examples, but the scope of the present invention is not limited by the following Examples.

Example 1-3

Next, a photocurable resin composition having a composition as shown in Table 1 was prepared, and the combination ratio of the photopolymerizable polyfunctional monomer in the photocurable resin composition was changed as shown in Table 2.

The polymer binder was an acrylic copolymer prepared by combining acrylic acid 10, methacrylic acid 15, methyl methacrylate 60, and 2-ethylhexyl acrylate 15 in weight% relative to the polymer binder. The physical properties of the dry film photoresist prepared from the composition of the photocurable resin composition were measured according to the measuring method described below and the results are shown in Table 3.

Comparative Example 1-3

A photosensitive resin composition was prepared in the same composition as in Example except that the combination ratio of the photopolymerizable polyfunctional monomer was changed from that in Table 2. The physical properties of the dry film photoresist prepared using this resin composition were measured according to the following measuring method, and the results are shown in Table 3.

TABLE 1

TABLE 2 Photocuring monomer composition ratios of Examples and Comparative Examples

How to measure

(Lamination)

A dry film photoresist made of a photocurable resin composition was laminated on one side of a copper-clad laminate of 1.6 mm thickness subjected to Pumice polishing, with a laminator roll temperature of 120 ° C., a roll pressure of 3.0 kg / cm 2 and a roll speed of 3.0 min / m. As a condition, lamination was carried out using Dynachem 360.

(Sensitivity)

The dry film photoresist laminated on the copper clad laminate was subjected to UV irradiation at 30mJ exposure dose using a Model 930SA manufactured by Collight as a 21-step stepper tablet negative photomask and left for 20 minutes. Thereafter, the development is carried out under the conditions of spray injection of 1.0% by weight of a sodium carbonate aqueous solution for 60 seconds at a temperature of 30 ° C., and dried in a hot air oven at 50 ° C. for 20 minutes.

(Developing chemical resistance)

The laminated film of the dry film photoresist was placed on the movable laminate to measure artwork and fine-wire adhesion, and was irradiated with ultraviolet light at an exposure dose of 30 mJ using Collite's Model 930SA and left for 20 minutes. After that, it developed at a break point of 50% at a temperature of 30 ° C., and evaluated the surface erosion of the circuit and the erosion state of the sidewall (circuit side wall when the circuit was formed) by an optical microscope.

(Tentability)

Drill 10 holes with a diameter of Φ8 mm at regular intervals on a copper substrate of 100 mm x 10 mm long. A dry film photoresist was laminated on the substrate using a laminate at a laminator roller temperature of 100 ° C. at a roller speed of 1.2 m / min and a roller pressure of 1.2 kgf / cm 2. Subsequently, the specimens were exposed to the same front and rear surfaces with an exposure dose of 40 mJ / cm 2 using an exposure machine without a photomisk, and then a round tip of 10 cm in length and 5 mm in diameter was applied to an Instron apparatus of Model-4301. The upper grip is fixed and the end of the specimen is fixed to a support which can be fixed, and then the hole is subjected to compression breaking by operating from top to bottom using a round bar. The measurement conditions were 100m / min crosshead speed and 500g load scale, and after compressing and breaking all 10 holes per sample, 10 compression fracture strength and elongation values were averaged.

TABLE 3 Physical property evaluation results of Examples and Comparative Examples

As shown in Table 3, the dry film photoresist made of the photocurable resin composition according to the present invention was found to have improved resistance to the developing agent while maintaining excellent tentability compared to the dry film photoresist made of the conventional resin composition. Can be.

Accordingly, the present invention provides a dry film photoresist that is resistant to developer while maintaining excellent tentability.

Claims (3)

In the photocurable resin composition containing a photopolymerizable polyfunctional monomer, a photoinitiator, a polymer binder, and an additive, the monomer of the following structural formulas (II) and (III) is used as a monomer of the following structural formula (I) as said photopolymerizable polyfunctional monomer. Photocurable resin composition characterized in that the composition is used alone or in combination. The photocurable resin composition according to claim 1, wherein the content of the photopolymerizable polyfunctional monomer to be used is 10 to 40% by weight based on the total amount of the photocurable resin composition. The composition ratio of the photopolymerizable polyfunctional monomer to be used is 5 to 30% by weight of the monomer of formula (I), and the sum of the compounds of formula (II) and (III) is 70 to 95% by weight. Photocurable resin composition characterized by the above-mentioned.