JPH08110643A - Method for developing photoresist - Google Patents

Abstract

PURPOSE: To efficiently develop a photosensitive layer with a cover coat layer and to form a high reliability resist pattern even on a substrate with through holes. CONSTITUTION: When a photoresist film laminated substrate consisting of a substrate, a photosensitive layer formed on the substrate and a cover coat layer formed on the photosensitive layer is subject to imagewise exposure and development to form a resist pattern, the cover coat layer is removed after the exposure with a washing agent which readily dissolves the cover coat layer but does not practically dissolve the photosensitive layer and then development is carried out with a developer which discriminatingly dissolves the exposed and unexposed parts of the photosensitive layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for developing a photoresist film.

[0002]

2. Description of the Related Art Conventionally, photoresists have been widely used for plating resists such as lithography resists and solder resists for manufacturing printed circuit boards and the like. As these photoresists, dry film resists have been widely used in which a photosensitive layer is provided on a support film having a thickness of about 25 to 75 μm, and a protective film is laminated on the side opposite to the support film, if necessary.

The dry film resist is formed by pressure-bonding a photosensitive layer on a substrate, exposing the photosensitive layer through a supporting film using a photomask or the like so as to obtain a required pattern, and then exposing the supporting film. Is peeled off and then developed to form a desired resist pattern on the substrate.

Since the dry film resist is exposed through the support film, the optical path length from the surface of the photomask to the photosensitive layer becomes long, and the resolution may be insufficient for forming a high-density circuit pattern. is there. In order to solve this drawback, printing a liquid photoresist by a method such as printing, roll coater, curtain flow coater, spray, electrodeposition coating to form a photosensitive layer on the substrate,
In order to obtain a desired pattern on the surface of the photosensitive layer, the photosensitive layer is subjected to differential exposure without interposing a supporting film to improve the resolution.

In the case of a liquid photoresist, an unexposed photoresist film (photosensitive layer) is used to enhance photosensitivity.
It is desirable that the glass transition temperature of is as low as possible, but when the glass transition temperature is lowered, the resist film surface becomes tacky, which makes alignment of the photomask difficult, contaminates the photomask, and dust on the resist film surface. However, there are problems that dust and the like are likely to adhere, defects are likely to occur in the resist pattern to be formed, and short-circuits and disconnections are likely to occur in the pattern obtained by etching.

Further, when a radical reaction is used as in a negative photoresist, the reaction is inhibited by oxygen in the atmosphere and the photosensitivity is lowered. In particular, the direct writing method in which the resist film is directly exposed to the laser light without using a photomask has a great influence.

In order to solve such a problem, the film thickness of 0.
A method of applying a non-sticky cover coat of about 5 to 5 μm at room temperature on the photosensitive layer, forming a cover coat layer on the support film, and then forming a photosensitive layer on the support film, and then placing the photosensitive layer on the substrate. A method has been proposed in which the support film is peeled off after pressure bonding to form a photosensitive layer with a cover coat on a substrate. In particular, when the reaction caused by exposure is likely to be inhibited by oxygen in the air like a radical reaction, a cover coat mainly composed of polyvinyl alcohol having extremely low oxygen permeability is used.

However, since the cover coat is generally a composition mainly composed of a resin having a high glass transition temperature,
The dissolution rate in a developing solution is usually much slower than the portion of the photosensitive layer to be removed by the development, and there is a problem that the developing time becomes long.

Further, in the case of a through-hole substrate, the corner portions of the through-holes tend to be thin in both the photosensitive layer and the cover coat layer, but at the time of development, they should be removed by developing the photosensitive layer on the flat portion of the substrate. It is necessary to contact the developer until both the part and the cover coat layer are removed. In this case, in the thin portion of the cover coat layer such as the corner portion of the through hole, since the photosensitive layer portion which should not be removed by the development is excessively contacted with the developing solution, the resist film in that portion is easily damaged, and There is a problem that the reliability of the formed pattern is lowered due to disconnection of the resist pattern to be formed or a defect in the pattern during etching.

When a nonionic water-soluble resin such as polyvinyl alcohol is mainly used as the cover coat, these resins cause salting out in a developing solution containing ions such as alkali or acid. It is easy and tends to precipitate in the developing solution, and this precipitate may adhere to the resist film surface to cause a defect in the resist pattern or etching pattern, resulting in a decrease in reliability of the formed pattern. .

Therefore, as a result of intensive studies to solve these problems, the inventors of the present invention found that the photosensitive layer was substantially sublimated in advance before the exposed photosensitive layer was brought into contact with a developing solution for development. The inventors have found that the problem can be solved by using a method of removing the cover coat by bringing the cover coat into contact with a cleaning solution that does not dissolve in the solution, but has completed the present invention.

[0012]

That is, the present invention is to imagewise expose a photoresist film laminated substrate comprising a substrate, a photosensitive layer formed on the substrate, and a cover coat layer formed on the photosensitive layer. A method of developing to obtain a resist pattern, which comprises removing a cover coat layer with a cleaning agent which easily dissolves the cover coat layer but does not substantially dissolve the photosensitive layer after exposure, and then exposes the exposed portion of the photosensitive layer. And a non-exposed portion are developed with a developing solution that differentially dissolves the photoresist film.

[0013]

In the present invention, the photosensitive layer constituting the photoresist film should be a photosensitive composition whose solubility in an alkaline or acidic developing solution or an organic solvent upon exposure largely changes with respect to the unexposed area. However, it is not particularly limited, and the following can be used as typical examples. 1. A film-forming component having a photopolymerizable functional group, an ion-forming group that reacts with a base or an acid to form an ion and becomes water-soluble, or a group having an ion pair on its own such as an onium salt, and a photopolymerizable component. A negative photosensitive composition containing a coalescence initiator component as an essential component. In this composition, the photopolymerizable functional group and the ion-forming group may be contained in the same film-forming component molecule, or may be contained in different molecules. Further, the photopolymer initiator component may be attached to the film forming component molecule or may be independent. These negative photosensitive compositions can be developed with an aqueous developer. 2. The same photosensitive composition as in the above negative photosensitive composition, except that it does not contain an ion-forming group. These photosensitive compositions can be developed with an organic solvent-based developer. 3. In the unexposed state, it is sparingly soluble in alkaline aqueous solution, but it contains a photosensitive group such as naphthoquinonediazide, which changes easily to alkaline aqueous solution upon exposure, as an essential component, and reacts with a base if necessary to generate ions. Positive-type photosensitive composition containing an ion-forming group that forms a. In these compositions, in the case of containing an ion-forming group, the photosensitive group and the ion-forming group may be contained in the same film-forming component molecule, or contained in different molecules. May be. When it has an ion-forming group, it can be developed with an aqueous developer, and when it has an ion pair itself such as an onium salt, it can be developed with water as a developer.
When it does not have an ion-forming group, it can be developed with an organic solvent-based developer.

These photosensitive compositions may be used as an organic solvent solution or may be used as an aqueous solution or an aqueous dispersion by neutralizing a part or all of the ion-forming groups. As the coating method of these photosensitive compositions, a roll coater, a spray, a curtain flow coater, a knife coater,
Known coating methods such as dipping coating method, printing method and electrodeposition coating method can be mentioned. When the photosensitive composition is neutralized and used as an aqueous solution or an aqueous dispersion to be applied on a conductive substrate, an electrodeposition coating method is particularly suitable. In addition, these photosensitive compositions are coated on a supporting film such as a plastic film to form a photosensitive layer in advance, and when necessary, pressure-bonded so that the surface of the photosensitive layer is in contact with the substrate, and then a supporting layer is formed. A photosensitive layer can be formed on the substrate by peeling off the film. In the present invention, the thickness of the photosensitive layer is usually 1 to 30 μm.

The cover coat layer used in the present invention is mainly composed of a resin having an ion-forming group which can be easily dissolved in an aqueous solution of a base or an acid, a nonionic water-soluble resin, and an onium salt group. Examples thereof include those mainly containing the water-soluble resin contained therein. The cover coat layer is appropriately selected according to the type of the photosensitive layer. For example,
When the photosensitive layer is developed with an alkaline developing solution, the cover coat is mainly composed of a nonionic water-soluble resin, an acid aqueous solution-soluble resin, or a water-soluble resin containing an onium salt group. An aqueous acid solution or water is preferably used as the cleaning agent. When the photosensitive layer is developed with an acidic developer, the cover coat is mainly composed of a nonionic water-soluble resin, an aqueous base solution-soluble resin, or a water-soluble resin containing an onium salt group. Is preferred, and an aqueous base solution or water is used as the detergent. When the film-forming component of the photosensitive layer has a cationic ion-forming group such as an onium salt, and when the photosensitive layer is developed with water, the cover coat is mainly composed of an aqueous base-soluble resin. Is preferred, and an aqueous base solution is used as the detergent.

It is necessary that the cover coat layer is not tacky at room temperature, and the glass transition temperature of the resin forming the cover coat layer is preferably 20 ° C. or higher. Typical examples of the resin forming the cover coat layer include an acrylic resin, an ethylene-acrylic copolymer, and a polybutadiene containing a carboxyl group or an amino group having a glass transition temperature of 20 ° C. or more in 1,000 g of the resin in an amount of 0.5 mol or more. Such as polydiene resin, amine adduct of epoxy resin, polyester resin, etc .; quaternary ammonium salt, quaternary phosphonium salt or tertiary sulfonium salt group as resin 1,00
Resins containing 0.3 mol or more in 0 g, polyvinyl alcohol, partial saponification of polyvinyl acetate, polyvinyl alcohol-vinyl acetate copolymer, partially saponified product of polyvinyl acetate-vinyl acetate copolymer, polyvinylpyrrolidone, pullulan, etc. Examples thereof include water-soluble resins such as water-soluble polysaccharide polymers. These resins can be used alone or in admixture of two or more kinds of base aqueous solution-soluble resins, acid aqueous solution-soluble resins, or nonionic water-soluble resins.

When the photosensitive layer undergoes a reaction involving free radicals when exposed to light, the cover coat layer may contain a resin having extremely low oxygen permeability such as polyvinyl alcohol or partially saponified polyvinyl acetate as a main component. preferable.

The thickness of the cover coat layer is usually 0.5 to 5
The thickness is μm, and it is preferable that the thickness is thin within the range where the original purpose of the cover coat layer such as prevention of surface tackiness and prevention of oxygen permeation can be fulfilled, from the viewpoint of resolution and shortening of cover coat removal time after exposure.

The cover coat layer is formed on the photosensitive layer, but its coating method is not particularly limited, and known coating methods such as roll coater, spray, curtain flow coater, knife coater, dipping coating method, printing method and the like. Can be mentioned. In addition, a cover coat is previously formed on a supporting film such as a plastic film,
When necessary, the surface of the photosensitive composition layer on the substrate and the cover coat are pressure-bonded so as to contact each other, and then the supporting film is peeled off to form the cover coat layer on the photosensitive composition layer on the substrate. be able to.

In the present invention, as the method for forming the photosensitive layer and the cover coat layer on the substrate, the following methods can be mentioned in addition to the above methods. A cover coat layer is formed on a supporting film such as a plastic film, then a photosensitive layer is formed on the cover coat layer, and a film type resist is further prepared in advance, if necessary, by laminating a protective film on the photosensitive layer. When necessary, the protective film is peeled off from the film-type resist as needed, and pressure-bonded so that the surface of the photosensitive composition layer is in contact with the substrate, and then the support film is peeled off to expose the substrate to light. A photoresist film, which is a multilayer of a layer and a cover coat layer, can be formed.

The substrate is, for example, an insulating substrate such as a glass fiber reinforced epoxy resin plate, a polyimide film or a ceramic plate; a conductive metal coating such as copper or indium oxide, tin oxide or antimony oxide is formed on these insulating substrates. Conductive oxide film such as formed by plating method, laminating method, vapor phase method, sol-gel method, or a combination of these methods; A treated substrate (through-hole substrate); a conductive metal plate or foil such as a metal such as copper, iron, aluminum, nickel, or an alloy of two or more of these metals.

In the present invention, exposure and development are performed on a photoresist film laminated substrate having a photosensitive layer and a cover coat layer formed on the substrate.

The exposure can be performed by a known method such as irradiating an actinic ray through a negative or positive type photomask having a desired image, or by irradiating a desired image with a direct drawing method. The actinic ray is not particularly limited, and an ultrahigh pressure mercury lamp, a high pressure mercury lamp,
Examples thereof include an actinic ray generated by a xenon lamp and a metal halide lamp, an argon ion laser beam, and sunlight.

In the present invention, the cover coat layer is removed with a cleaning agent after the exposure and before the development with the developing solution. This cleaning agent dissolves the cover coat layer easily but does not substantially dissolve the photosensitive layer, and may be appropriately selected depending on the type of the cover coat layer. When the cover coat is mainly composed of a nonionic water-soluble resin or a water-soluble resin containing an onium salt group, water is preferable as the detergent. When the cover coat is mainly composed of an acid aqueous solution-soluble resin, the cleaning agent is preferably an acid aqueous solution, and when it is mainly composed of a neutralized product of those resins, water or an acid aqueous solution is preferable. When the cover coat is mainly composed of a resin capable of dissolving an aqueous base solution, the detergent is preferably an aqueous base solution, and when it is mainly composed of a neutralized product of these resins, water or an aqueous base solution is preferable.

The aqueous acid solution used as the above-mentioned detergent is a 0.1 to 5% aqueous solution of an inorganic acid such as hydrochloric acid or sulfuric acid, or 0.1 to 5% of an organic acid such as formic acid, acetic acid, lactic acid or hydroxyacetic acid.
A 10% aqueous solution may be used. Examples of the aqueous base solution used as the above-mentioned detergent include 0.1-10% aqueous solutions of inorganic bases such as sodium carbonate, sodium silicate, sodium metasilicate, caustic soda, and caustic potash, 0.1-10% aqueous ammonia solution, dimethylaminoethanol, Examples thereof include 0.1 to 10% aqueous solutions of organic bases such as diethanolamine and N-methylethanolamine.

In the present invention, after the cover coat layer is removed with the above cleaning agent, development with a developing solution is carried out. The development may be carried out by a known developing method such as a method of spraying an alkaline aqueous solution such as sodium carbonate or sodium metasilicate or an acid aqueous solution such as hydrochloric acid or sulfuric acid on the photosensitive layer, or a method of immersing the photosensitive layer in the alkaline aqueous solution or the aqueous acid solution. it can. An image-like resist pattern is formed by the development process.

When the image-like resist pattern obtained as described above is formed on a conductive substrate for forming a circuit or the like, an acid such as cupric chloride or ferrous chloride is used. Using a known etching solution such as an etching solution or an alkaline etching solution such as an ammonia / ammonium chloride system, contact is made by a spray method, a dipping method, etc., and is not covered with the resist on the conductive substrate, that is, exposed. An etching pattern can be formed by removing the above-mentioned conductive film and, if necessary, washing with water and drying with water.

The conductive substrate having an etching pattern obtained as described above is, if necessary, contacted with an alkaline aqueous solution such as caustic soda or caustic potash, or an inorganic or organic acid aqueous solution to leave a resist remaining on the pattern. The conductive pattern can be formed by removing the coating film and washing with water and draining and drying if necessary.

[0029]

Since the photoresist film laminated substrate used in the method of the present invention has the cover coat layer formed on the photosensitive layer, the thickness of the cover coat layer can be reduced.
Since the optical path length from the surface of the cover coat layer to the surface of the photosensitive layer at the time of exposure can be shortened, the resolution can be improved in response to higher density. Since the cover coat layer is non-adhesive at room temperature, dust, dust, etc. are unlikely to adhere to the photoresist film, and the photo mask can be easily aligned, and the photo mask is not contaminated. Further, since the surface can be made non-tacky by providing the cover coat layer, the glass transition temperature of the photosensitive layer can be lowered, which is advantageous in the case of a negative type photosensitive layer from the viewpoint of improving the photosensitivity.

Further, even when the exposed part of the photosensitive layer of the resist film is differentiated from the unexposed part by the radical reaction, particularly when exposed by the direct drawing method, the reaction is not inhibited by oxygen in the atmosphere, which is preferable. Photosensitivity can be obtained.

In the method of the present invention, since the cover coat layer is removed by the cleaning solution before the development by the developing solution, the photoresist film is thinner than the other parts such as the through hole corners of the through hole substrate. A reliable pattern is formed even at a portion because it does not contact the developer for an excessively long time. Further, in the method of the present invention, since the cover coat layer is removed by the washing solution before the development by the developing solution, the dissolved matter of the cover coat layer is not mixed in the developing solution. There is also no possibility of causing a resist pattern defect by adhering to.

[0032]

EXAMPLES The present invention will be described in more detail by way of examples. Hereinafter, “part” and “%” are unless otherwise specified.
Each shall be based on weight.

Synthesis of Resin Solution Containing Unsaturated Group Synthesis Example 1 40 parts of methyl methacrylate, 40 parts of butyl acrylate
Part, acrylic acid 20 parts, and azobisisobutyronitrile 2 parts under a nitrogen gas atmosphere,
It was added dropwise to 90 parts of propylene glycol monomethyl ether kept at 0 ° C. over 3 hours. After the dropping, the mixture was aged for 1 hour, a mixed solution of 1 part of azobisdimethylvaleronitrile and 10 parts of propylene glycol monomethyl ether was added dropwise over 1 hour, and the mixture was aged for 5 hours to obtain a high acid value acrylic resin (acid value). 155) A solution was obtained. Next, 24 parts of glycidyl methacrylate, 0.12 part of hydroquinone and 0.6 part of tetraethylammonium bromide were added to this solution, and air was blown into the solution at 110 ° C. for 5 hours.
Unsaturated group-containing resin (acid value about 50, degree of unsaturation 1.35 mol / kg, Tg point 20 ° C, number average molecular weight about 2)
50,000) solution was obtained.

Synthetic Example 2 Ethylene glycol monoethyl ether 90 held at 120 ° C. under a nitrogen gas atmosphere in a mixed solution of 60 parts of styrene, 10 parts of methyl acrylate, 30 parts of acrylic acid and 3 parts of azobisisobutyronitrile. 3 in the division
It took time to drop. After the dropping, the mixture was aged for 1 hour, a mixed solution containing 1 part of azobisdimethylvaleronitrile and 10 parts of ethylene glycol monoethyl ether was added dropwise over 1 hour, and the mixture was aged for 5 hours to obtain a high acid value acrylic resin (acid. Valence 233) solution was obtained. Next, 35 parts of glycidyl methacrylate, 0.13 part of hydroquinone and 0.6 part of tetraethylammonium bromide were added to this solution and reacted at 110 ° C. for 5 hours while blowing air to obtain an unsaturated group-containing resin (acid value about 70, Saturation 1.83 mol / k
g, Tg point 45 ° C., number average molecular weight about 15,000) to obtain a solution.

Synthesis Example 3 A mixed solution of 20 parts of methyl methacrylate, 60 parts of acrylic acid, 20 parts of methacrylic acid and 6 parts of t-butyl peroxyoctoate was added under a nitrogen gas atmosphere at 11
It dripped in 90 parts of n-butyl alcohol kept at 0 degreeC over 3 hours. After the dropping, the mixture was aged for 1 hour, a mixed solution of 1 part of azobisdimethylvaleronitrile and 10 parts of propylene glycol monomethyl ether was added dropwise over 1 hour, and the mixture was aged for 5 hours to obtain a high acid value acrylic resin solution. It was Next, 114 parts of glycidyl methacrylate, 0.24 part of hydroquinone and 1.0 part of tetraethylammonium bromide were added to this solution, and the mixture was reacted at 110 ° C. for 5 hours while blowing air to obtain an unsaturated group-containing resin (acid value of about 70, Saturation degree 3.75 mol / kg, Tg point 8
A solution having a number average molecular weight of about 18,000) was obtained.

Synthesis Example 4 30 parts of methyl methacrylate, 35 parts of butyl acrylate
Part, 35 parts of glycidyl methacrylate, and 2 parts of azobisisobutyronitrile were added dropwise to 90 parts of propylene glycol monomethyl ether kept at 110 ° C. over 3 hours under a nitrogen gas atmosphere.
After dropping, aged for 1 hour, 1 part of azobisdimethylvaleronitrile and propylene glycol monomethyl ether 1
A mixed solution consisting of 0 parts was added dropwise over 1 hour, and then 5
It was aged for a time to obtain a glycidyl group-containing acrylic resin solution. Next, 10 parts of acrylic acid, 0.12 part of hydroquinone and 0.6 part of tetraethylammonium bromide were added to this solution and reacted at 110 ° C. for 5 hours while blowing air, then cooled to 50 ° C. and methylaminoethanol 8.0. Part, and reacted at 70 ° C for 2 hours to give a tertiary amino group-containing unsaturated resin (amino group concentration of about 0.91 mol / k
g, unsaturation degree 1.18 mol / kg, Tg point about 6 ° C., number average molecular weight about 20,000).

Production of Photosensitive Resin Solution Production Example 1 A solution prepared by dissolving 3 parts of a photopolymerization initiator α-hydroxyisobutylphenone in 477 parts of propylene glycol monomethyl ether was added to 100 parts of the unsaturated group-containing resin solution obtained in Synthesis Example 1. Then, isopropanol was added so that the solid content was 10% to obtain a photosensitive resin solution.

Production Example 2 To 100 parts of the unsaturated group-containing resin solution obtained in Synthesis Example 2, 478 parts of isobutyl alcohol and 2 parts of benzoin ethyl ether as a photopolymerization initiator were added, and the solid content was 10%.
Isopropanol was added to the mixture so that the amount became 100% to obtain a photosensitive resin solution.

Production Example 3 To 180.6 parts (100 parts by solid content) of the unsaturated resin solution obtained in Synthesis Example 3 was added 6 parts of triethylamine for neutralization, and then 5 parts of benzyl alcohol was added to the sensitizer (Note 1). ) A solution in which 1 part is dissolved is added and mixed, and further, a solution in which 1 part of a polymerization initiator (Note 2) is dissolved in 5 parts of diethylene glycol dimethyl ether is added and mixed, and then 20 parts of ethylene glycol monobutyl ether is mixed. , And then add deionized water to adjust the solids concentration to 15%,
An electrodeposition coating bath which is a photosensitive resin solution was obtained.

(Note 1) Sensitizer: A compound represented by the following chemical formula.

[0041]

Embedded image

(Note 2) Polymerization initiator: A compound represented by the following chemical formula.

[0043]

Embedded image

Production Example 4 Tertiary amino group-containing unsaturated resin solution 218 obtained in Synthesis Example 4
6 parts of a photopolymerization initiator α-hydroxyisobutylphenone was added to 1 part (a solid content of 118 parts), and isopropanol was further added so that the solid content was 10% to obtain a photosensitive resin solution.

Production of Cover Coat Solution Production Example 5 Polyvinyl acetate having a saponification degree of 80% was gradually added to water heated to 70 ° C. and dissolved to obtain a cover coat solution (1) having a solid content of 12%.

Production Example 6 A flask was charged with 1,000 parts of isopropyl alcohol and kept at 100 ° C., in which 118 parts of N, N-diethylaminoethyl methacrylate, 784 parts of isopropyl methacrylate and 98 parts of methyl acrylate were added. After 1,050 parts of a solution prepared by adding 50 parts of azobisisobutyronitrile to 1,000 parts of the monomer mixed solution was gradually added dropwise over 2 hours, the temperature was further maintained at 100 ° C. for 5 hours. After cooling to room temperature, 8,000 parts of isopropyl alcohol was added to obtain a cover coat solution (2) having a solid content of about 10%.

Production Example 7 A flask was charged with 1,000 parts of isopropyl alcohol and kept at 100 ° C., in which acrylic acid 12 was added.
Solution 1,0 obtained by adding 50 parts of azobisisobutyronitrile to 1,000 parts of a monomer mixture liquid consisting of 3 parts, 175 parts of methyl methacrylate and 702 parts of methyl acrylate.
50 parts was gradually added dropwise over 2 hours, and then 100 parts was added.
Hold at 5 ° C for 5 hours. After cooling to room temperature, 101 parts of triethylamine and 7,899 parts of deionized water were added to obtain a cover coat solution (3) having a solid content of about 10%.

Production Example 8 (Production of Cover Coat Film) The cover coat solution (1) obtained in Production Example 5 was applied to a release-treated polyethylene terephthalate film having a thickness of 75 μm by a wire bar to give a dry film thickness of 2.5 μm. And then dried at 80 ° C. for 5 minutes to obtain a cover coat film.

Production Example 9 (Production of Film Type Resist) The photosensitive resin solution obtained in Production Example 1 was coated on the cover coat film obtained in Production Example 8 with a wire bar coating machine so that the dry film thickness was 12 μm. It was coated and dried at 80 ° C. for 10 minutes to obtain a film type resist.

Preparation Example 1 of Photoresist Film Laminated Substrate Preparation Example 1 The photosensitive resin solution obtained in Production Example 1 was plated with 0.35 to 0.8 mmφ through holes on its inner wall (500 holes in total).
With a copper layer having a thickness of 45 μm on the surface.
A 6 mm glass-reinforced epoxy plate with through holes filled with hole-filling ink (Somar TH-700) was coated on a substrate with a wire bar coating machine to a dry film thickness of 12 μm and dried at 80 ° C. for 30 minutes. The cover coat solution obtained in Production Example 5 was applied by dipping to a dry film thickness of 2.5 μm, and then dried at 80 ° C. for 5 minutes to obtain a laminated substrate 1.

Preparation Example 2 The surface of the photosensitive resin solution obtained in Production Example 2 was 35 μm thick.
Was coated on a 1.6 mm thick glass fiber reinforced epoxy plate laminated with copper foil by a roll coater coater so as to have a dry film thickness of 15 μm and dried at 80 ° C. for 30 minutes, and then the cover coat solution of Production Example 6 Was applied by spray coating so as to have a dry film thickness of 3.5 μm, and then dried at 80 ° C. for 5 minutes to obtain a laminated substrate 2.

Preparation Example 3 A copper foil having a thickness of 35 μm was laminated on the surface to a thickness of 1.6.
mm of glass fiber reinforced epoxy plate was dipped in the photosensitive resin solution obtained in Production Example 3, and the glass fiber reinforced epoxy plate was used as an anode, and a direct current with a current density of 60 mA / cm ² was applied between the counter electrode and the counter electrode.
After energizing for 20 seconds, it was washed with water and dried at 80 ° C. for 10 minutes to form a photosensitive layer having a dry film thickness of 7 μm, and then the cover coat solution obtained in Production Example 5 was spray coated to give a dry film thickness of 1.0 μm. After coating in this manner, the laminated substrate 3 was obtained by drying at 60 ° C. for 5 minutes.

Preparation Example 4 The photosensitive resin solution obtained in Production Example 4 was applied on the surface to a thickness of 35 μm.
Was coated on a 1.6 mm thick glass fiber reinforced epoxy plate laminated with copper foil by a roll coater coater so as to have a dry film thickness of 15 μm and dried at 80 ° C. for 20 minutes, and then, a cover coat solution of Production Example 7 Was spray coated to a dry film thickness of 2.5 μm, and then dried at 80 ° C. for 5 minutes to obtain a laminated substrate 4.

Preparation Example 5 The surface of the photosensitive resin solution obtained in Production Example 1 was 35 μm thick.
After coating with a screen printing machine to a dry film thickness of 20 μm on a 1.6 mm thick glass fiber reinforced epoxy plate laminated with the copper foil of, the photosensitive layer was formed by drying at 80 ° C. for 10 minutes. The cover coat film obtained in 8 was pressure-bonded onto the photosensitive layer so that the cover coat layer faced, and then the support film was peeled off to form a cover coat layer having a thickness of 2.5 μm to obtain a laminated substrate 5. .

Preparation Example 6 A surface of which a copper foil having a thickness of 35 μm is laminated has a thickness of 1.6.
The film-type resist obtained in Production Example 9 was pressure-bonded to a glass fiber reinforced epoxy plate of mm so that the surface of the photosensitive resin layer faced the copper foil surface, and then the supporting film was peeled off to obtain a laminated substrate 6.

Example 1 On the photoresist film surface of the laminated substrate 1 obtained in Preparation Example 1,
Through negative film, exposure amount is 100mJ with high pressure mercury lamp.
/ cm ² and after the exposure so that the liquid temperature of 30 ° C. water as covercoat washing solution, washed cover coat layer under the conditions of a spray pressure of 1.2 kg / cm ^2, cleaning time 5 seconds, then the concentration 0. Liquid temperature 3 using 75% sodium carbonate aqueous solution as developer
Development was carried out under conditions of 0 ° C., a spray pressure of 1.2 kg / cm ² , and a cleaning time of 20 seconds to obtain a resist pattern.

Examples 2 and 4 to 6 and Comparative Examples 1, 2 and 4 to 6 In Example 1, the types of laminated substrates, the types of cover coat cleaning solutions and the cleaning times, and the types of developing solutions and the developing times are shown in the table below. A resist pattern was obtained in the same manner as in Example 1 except that the procedure described in 1 was performed.

Example 3 and Comparative Example 3 On the photoresist film surface of the laminated substrate 3 obtained in Preparation Example 3,
Exposure amount 1 with light of wavelength 488 nm of argon ion laser
After exposure under the condition of mJ / cm ^2, the exposed plate was washed with the cover coat layer and developed to obtain a resist pattern. The cleaning and developing of the cover coat layer were performed in the same manner as in Example 1 except that the type and the cleaning time of the cover coat cleaning liquid, and the type and the developing time of the developing liquid were as shown in Table 1 below.

(Note) in Table 1 has the following meanings. (* 1) A: 0.5% formic acid aqueous solution (* 2) B: 0.2% sodium carbonate aqueous solution (* 3) a: 0.75% sodium carbonate aqueous solution (* 4) b: 0.3% lactic acid aqueous solution

The states of the resist coatings around the through holes obtained in Examples 1 to 6 and Comparative Examples 1 to 6 after development were observed. Table 1 shows the results. Evaluation is based on the following criteria. ◯: No abnormality was observed and the resist film was completely covered. Δ: 1 to 10 of all through holes in the substrate were not completely covered with the resist film. X: 11 or more of all through holes in the substrate were not completely covered with the resist film.

[0061]

[Table 1]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naozumi Iwasawa 4-17-1, Higashi-Hachiman, Hiratsuka City, Kanagawa Kansai Paint Co., Ltd.

Claims (5)

[Claims] 1. A method for obtaining a resist pattern by imagewise exposing and developing a photoresist film laminated substrate comprising a substrate, a photosensitive layer formed on the substrate, and a cover coat layer formed on the photosensitive layer. That is, after the exposure, the cover coat layer is easily dissolved but the photosensitive layer is not substantially dissolved. A method for developing a photoresist film, which comprises developing with a developing solution that dissolves. 2. The developing method according to claim 1, wherein the cleaning agent is water or an aqueous solution of an acid, and the developing solution is an alkaline developing solution. 3. The developing method according to claim 1, wherein the cleaning agent is water or an alkaline aqueous solution, and the developing solution is an acidic developing solution. 4. The developing method according to claim 1, wherein the exposed portion of the photosensitive layer is insoluble in a developing solution. 5. The developing method according to claim 1, wherein the exposed portion of the photosensitive layer is soluble in a developing solution.