JPH07244374A - Water soluble photosensitive resin composition and pattern forming method using the same - Google Patents

Abstract

PURPOSE:To provide a water soluble photosensitive resin composition particularly excellent in the resistance against an acidic etchant, having high sensitivity, high resolution, excellent preservable stability and excellent adhesibility to a substrate and easily strippable by a concentrated alkaline aq. solution and to provide a forming method using the same, safe with respect to the view point of the countermeasure of environmental protection and capable of forming a photosetting pattern free from the swelling or flowing out of the pattern at the time of developing the pattern and true to a mask pattern. CONSTITUTION:The water soluble photosensitive resin composition is obtained by incorporating casein and a high molecular compound having a structural unit expressed by a formula (in the formula, X represents Na, K or NH4). The photosetting pattern is formed by applying the water soluble photosensitive resin composition on the substrate and after that, allowing the pattern to come into contact with a diluted acid aq. solution after or before exposing and next, developing it with diluted alkali, or the photosetting pattern is formed by applying the water soluble photosensitive resin compound on the substrate and after exposing, developing the pattern with a boric acid aq. solution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-soluble photosensitive resin composition and a pattern forming method using the same, and particularly, it has excellent resistance to an acidic etching solution, high sensitivity, high resolution and good storage stability. The present invention also relates to a water-soluble photosensitive resin composition which has excellent adhesion to a substrate and can be easily peeled off with a concentrated alkaline aqueous solution, and a pattern forming method using the same.

[0002]

2. Description of the Related Art In the manufacture of shadow masks for color cathode ray tubes, a thin plate of low carbon aluminum killed steel or amber alloy containing 36% nickel is used as a substrate, which is first degreased and rinsed with water, and then surface-sensitized. The resin composition is applied, dried and formed into a film. Then, a mask pattern having a target image is brought into close contact with the substrate at a position corresponding to the electron beam passage hole, exposed to light, and developed and hardened to form a corrosion-resistant film (resist film) having a predetermined pattern.
To form. Then, using, for example, an aqueous solution of ferric chloride, the portion where the resist film is not formed on the substrate is etched (acid etching) to form a large number of electron beam transmission holes, and then the resist film is peeled off to form a shadow mask. Creating.

Conventionally, in the manufacture of electronic parts such as shadow masks for color cathode ray tubes, IC lead frames, meshes for fluorescent display tubes, etc., an aqueous solution containing casein as a main component is used to form a resist film as an etching mask. A water-soluble photosensitive resin composition to which a dichromate aqueous solution such as ammonium dichromate has been added has been used as a photosensitizer. An aqueous solution of chromic anhydride has been used in the hardening process. All of these contain hexavalent chromium in the treatment waste liquid.

However, in terms of environmental protection measures, the hexavalent chromium drainage standard is 0.5 ppm or less, and the total chromium amount is 2 p.
Since it is regulated to pm or less, if a photoresin composition containing a chromate or a dichromate or a curing agent is used to manufacture an electronic manufacturing part, the cost of wastewater treatment alone will be enormous. Therefore, there is a problem in that the manufacturing cost must be increased significantly.

Therefore, as a water-soluble photosensitive resin composition containing no chromium, for example, a photosensitive solution containing a casein and an azide compound is disclosed in JP-B-41-7100, and a polyvinyl alcohol is disclosed in JP-B-44-28725. And a tetrazonium salt, a diazide compound, a plate-making photosensitive solution comprising a photosensitive component such as a diazo resin, respectively, are disclosed,
Also, Japanese Examined Japanese Patent Publication Nos. 56-20541 and 56-42859.
No. 57-6098 and the like propose a water-soluble resist containing polyvinyl alcohol and a diazo resin, and a film-hardening agent and a treatment method thereof.
No. 57-249905 and the like propose hardeners, but there are many deficiencies in their properties.
The current situation is that it has not been put to practical use.

Further, in the casein-dichromate type water-soluble photosensitive resin composition, a pattern excellent in resolution and acid resistance can be obtained if it is handled with great care, but the substrate metal and chromium A dark reaction occurs due to a reaction with an acid salt, resulting in a change in sensitivity.The dark reaction depends on temperature and humidity conditions. As a result, variations in sensitivity occur. However, there are problems such as lack of storage stability, deterioration of the resolution of the resist, deterioration of developability, and the like due to the above items.

Under these circumstances, it has been desired to develop a non-chromium type casein-containing water-soluble photosensitive resin composition in place of the casein-dichromate type water-soluble photosensitive resin composition. In addition, there has been a demand for development of a resist hardener and a hardener which do not use chromium.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to:
Particularly as a resist as an etching mask pattern, it has excellent resistance to acidic etching solutions, high sensitivity, high resolution, good storage stability, and excellent adhesion to substrates, and can be easily peeled off with a concentrated alkaline aqueous solution. Another object of the present invention is to provide a water-soluble photosensitive resin composition and a pattern forming method using the same.

[0009]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have satisfied the above problems by containing casein and a polymer compound having a specific structural unit. The present inventors have found that a water-soluble photosensitive resin composition can be obtained, and based on this, the present invention has been completed.

The inventors of the present invention also harden the water-soluble photosensitive resin composition by applying a dilute acid treatment after applying the water-soluble photosensitive resin composition on a substrate, either before or after an exposure step through a mask pattern. It was found that a photo-curing pattern faithful to a mask pattern can be formed by forming a film and then developing with a dilute aqueous alkali solution, and based on this, the method of the present invention was completed.

Further, the inventors of the present invention can form a photo-curing pattern faithful to the mask pattern by coating the above water-soluble photosensitive resin composition on a substrate, exposing it to light, and developing it with an aqueous solution of boric acid. Based on this finding, it was possible to complete the method of the present invention.

That is, the present invention relates to casein and the following chemical formula 2

[0013]

[Chemical 2] The present invention provides a water-soluble photosensitive resin composition containing a polymer compound having a structural unit represented by the formula (wherein X represents Na, K or NH ₄ ).

In the present invention, the above water-soluble photosensitive resin composition is coated on a substrate, brought into contact with a dilute acid aqueous solution, and then selectively exposed through a mask pattern, and then with a dilute alkaline aqueous solution. A pattern forming method for forming a photo-cured pattern on a substrate by developing and removing an unexposed portion.

In the present invention, the above-mentioned water-soluble photosensitive resin composition is applied on a substrate, selectively exposed through a mask pattern, brought into contact with a dilute aqueous acid solution, and then developed with a dilute aqueous alkali solution. Then, a pattern forming method for forming a photo-cured pattern on the substrate by removing the unexposed portion is provided.

Further, in the present invention, the above water-soluble photosensitive resin composition is applied onto a substrate, selectively exposed through a mask pattern, and then developed with an aqueous boric acid solution to remove the unexposed portion. Thus, a pattern forming method for forming a photo-curing pattern on a substrate is provided.

The constituents of the water-soluble photosensitive resin composition of the present invention and the pattern forming method using the constituents will be described in detail below.

First, as the casein which is an essential constituent component of the water-soluble photosensitive resin composition of the present invention, any one which can be used in the photosensitive resin composition can be used.
Particularly, from the viewpoint of stability, an aqueous solution of casein obtained by dissolving acid casein in water containing an organic or inorganic alkaline agent such as borax, amines, caustic alkali such as sodium hydroxide and potassium hydroxide is preferably used. These are, for example, "FR
-15 "," FR-16 "," FR-17 "(all manufactured by Fuji Pharmaceutical Co., Ltd.)," G-90L "," G-90 "
"M""G-90S""G-90W""G-90SDN"
(All of the above are manufactured by Tokyo Ohka Kogyo Co., Ltd.) and the like, and are commercially available.

The polymer compound (photopolymer) having the constitutional unit represented by the above chemical formula 2 which is another essential constituent is, for example, diacetone acrylamide and another monomer, preferably a water-soluble monomer, by a known method. Water-soluble polymer (base polymer) obtained by copolymerization,
It can be obtained by introducing at least one selected from 4-azidobenzaldehyde-2-sulfonic acid and salts thereof by aldol condensation reaction, but the synthetic method is not limited thereto.

Examples of the above water-soluble monomer include acrylic acid, methacrylic acid, dimethylacrylamide, diethylacrylamide, acryloylmorpholine, dimethylaminoethylacrylamide, N-vinyl-2-pyrrolidone, etc. Dimethylacrylamide and acryloylmorpholine are preferred. In addition, vinyl acetate that produces an alcoholic hydroxyl group by a hydrolysis reaction after copolymerization is also included in the water-soluble monomer. These water-soluble monomers may be used alone or in combination of two or more.

The copolymerization reaction ratio of the diacetone acrylamide and the water-soluble monomer is preferably 0.5 to 10 mol, more preferably 1.5 to 3.0 mol, based on 1 mol of diacetone acrylamide. Is. This is because if the proportion of the water-soluble monomer exceeds 10 moles, the photosensitivity may decrease, while if it is less than 0.5 moles, the solubility may deteriorate, which is not preferable.

The water-soluble polymer thus obtained preferably has a weight average molecular weight of 15 × 10 ^{4 to} 100 × 10 ⁴ , and more preferably 20 × 10 ⁴ to 30.
It is × 10 ⁴ . The dispersity is 1 to 10, preferably 1 to 3, and more preferably 1 to 2.

Next, at least one selected from 4-azidobenzaldehyde-2-sulfonic acid and salts thereof is introduced into this water-soluble polymer by an aldol condensation reaction. 5 to 95 mol%, more preferably 30 to 90 mol%, particularly preferably 80 to 90 mol% relative to 100 mol% of acetone acrylamide.

In this way, a polymer compound (photopolymer) having the constitutional unit represented by the above chemical formula 2 can be obtained.

When vinyl acetate is used as the water-soluble monomer, a hydroxyl group-containing water-soluble polymer can be synthesized by copolymerizing diacetone acrylamide and vinyl acetate and hydrolyzing the acetic acid group with alkali. . This hydroxyl group-containing water-soluble polymer is preferably used because it becomes a water-soluble polymer capable of forming a pattern having extremely excellent water resistance by introducing an aldehyde by an acetalization reaction in an acidic aqueous solution.

Examples of such aldehydes include aliphatic aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde and crotonaldehyde; aromatic aldehydes such as benzaldehyde, dialkylbenzaldehyde, alkylbenzaldehyde and cinnamicaldehyde. Aldehydes; heterocyclic aldehydes such as pyridine aldehyde; and the like. These aldehydes also include 4-azidobenzaldehyde-2-sulfonic acid and salts thereof, formylstyrylpyridine and quaternized salts thereof, and the like. These aldehydes may be used alone or in combination of two or more. Practically preferably used are propionaldehyde, n-butyraldehyde,
It is crotonaldehyde and the like, among which n-butyraldehyde is most preferably used.

In the acetalization reaction with the aldehydes, it is preferable to acetalize 15 mol% or less of all hydroxyl groups of the water-soluble polymer. If it exceeds 15 mol%, it is difficult to obtain a water-soluble polymer having excellent stability. In this case, the degree of polymerization of the water-soluble polymer to be synthesized is preferably 100 to 3,000, more preferably 500 to 2,500.

The polymer compound (photopolymer) having the structural unit represented by the above chemical formula ^{2 has} a sensitivity in the gray scale method (Kod) when exposed to a light amount of 10 mJ / cm ^2.
akPhotographic Step Table
t No. It is preferable that 13 to 18 steps, more preferably 14 to 15 steps remain in (using 2).
If it is less than 13 steps, the sensitivity is too low to be practical,
On the other hand, when it exceeds 18, storage stability is poor and handling is difficult.

In the present invention, in addition to the above-mentioned essential constituents, a compatible polymer and various additives, if necessary,
For example, a colorant, a plasticizer, a surfactant, a coupling agent for increasing the adhesion to the substrate, and the like can be appropriately added and mixed. Particularly, by blending polyvinyl alcohol or modified polyvinyl alcohol as a compatible polymer, the dissolution and peeling property of the resist pattern can be improved. These polyvinyl alcohols and modified polyvinyl alcohols may be water-soluble ones and may be partially saponified or completely saponified. As the modified polyvinyl alcohol, use of various modified polyvinyl alcohols such as those modified with diacetone acrylamide, acryloylmorpholine, N-vinyl-2-pyrrolidone, etc., or those having a silicone-containing group added to the side chain. You can These may be used alone or in combination of two or more.

The water-soluble photosensitive resin composition of the present invention is prepared by blending the casein, the polymer compound (photopolymer) having the constitutional unit represented by the chemical formula 2, and, if necessary, the additive component in a predetermined amount. can get. The compounding ratio of casein and photopolymer is preferably 100 to 40% by weight of casein solids in the casein solution, and 4 to 40% by weight of photopolymer solids in the photopolymer solution is preferably mixed, and more preferably 20 to 30%. It is about% by weight. If the blending ratio of the photopolymer solid content is less than 4% by weight, the sensitivity is lowered and the water resistance is deteriorated, while if it exceeds 40% by weight, the releasability is lowered.

Next, the pattern forming method according to the present invention using the water-soluble photosensitive resin composition of the present invention will be described below.

According to the pattern forming method of the present invention, after the above water-soluble photosensitive resin composition is applied onto a substrate, it is contacted with a dilute aqueous acid solution before or after selective exposure, and then with a dilute aqueous alkali solution. The photo-cured pattern can be formed by developing and removing the unexposed portion. Here, the method of contacting with the dilute aqueous acid solution is not particularly limited, and any method such as immersing in the dilute aqueous acid solution, spraying the dilute aqueous acid solution, or flowing down can be used.

The above water-soluble resin composition has, for example, a solid content of 5
A solution diluted with pure water, an alkaline aqueous solution, or the like so as to be about 12% is used as a coating solution, and this is coated on a substrate. Examples of the substrate to be used include decarburized aluminum-killed steel and nickel-iron alloy (amber material) containing 36% nickel, which are usually used for shadow mask production, but also copper, zinc, iron, nickel,
Examples include metal substrates such as aluminum, stainless steel, and copper alloys, and glass and silicon substrates.

The substrate coated with the water-soluble photosensitive resin composition is contacted with a dilute aqueous acid solution before or after exposure. For the exposure, UV lamps and UV lamps that output light in the vicinity of 350 to 400 nm are preferably used, and the amount of light is slightly different depending on the composition of the water-soluble photosensitive resin composition, but is about 100 to 1000 mJ / cm ^2. preferable.

The contact with a dilute aqueous acid solution is for hardening the applied water-soluble photosensitive resin composition (photoresist), and thereby prevents pattern swelling and pattern collapse due to outflow during development. can do. Therefore, it is possible to form a photo-curing pattern that is faithful to the mask pattern. Further, since the film-hardening treatment can be carried out without using chromate as in the prior art, there is no fear of harming the human body in terms of environmental protection and it is safe. The dilute aqueous acid solution used is acetic acid, oxalic acid,
As an example, an approximately 0.2% aqueous solution of an organic acid such as citric acid, tartaric acid or malic acid, or a mineral acid such as phosphoric acid, sulfamic acid, hydrochloric acid, sulfuric acid or nitric acid may be used. Organic carboxylic acids such as acetic acid, oxalic acid, tartaric acid, citric acid, and malic acid are particularly preferably used because of their ease and low corrosiveness to the substrate. The contact with the dilute aqueous acid solution is carried out for about 10 to 30 seconds, and it is preferable to wash with water and dry.

Next, development is carried out. In the present invention, a dilute alkaline aqueous solution is used as a developing solution. As this developer,
For example, ammonia, sodium hydrogen carbonate, sodium carbonate, caustic alkali, inorganic alkali such as amine, dilute alkali aqueous solution of organic alkali and the like are mentioned as preferable ones, and among them, 0.05% ammonia aqueous solution, 0.1 to 1.0% Aqueous sodium hydrogen carbonate solution, 0.2 to 0.5% sodium carbonate and the like are particularly preferably used.

According to the above pattern forming method, the resist is hardened by contacting it with a dilute aqueous acid solution before or after exposure (photocuring), so that the pattern is not swollen or washed away during development. It is possible to obtain a photo-curing pattern that is faithful to the mask pattern. Furthermore, since it is not necessary to use an organic solvent or the like as a developing solution, it is advantageous from the viewpoint of environmental protection measures. The development can be performed by an arbitrary method such as a spray gun or a dipping method.

According to another pattern forming method of the present invention, the water-soluble photosensitive resin composition is applied onto a substrate,
After this is selectively exposed through a mask pattern, it is developed with an aqueous solution of boric acid to remove the unexposed portion, whereby a photo-cured pattern can be formed on the substrate.

As an aqueous solution of boric acid, 0.2 to 3.0%
A boric acid aqueous solution is preferably used. Note that coating, exposure, etc. on the substrate can be performed in the same manner as in the case of the above forming method.

In this pattern forming method, the pattern is not swollen or washed away at the time of development, and no pattern collapse is observed. Therefore, it is possible to form a photo-curing pattern that is faithful to the mask pattern without contacting with the dilute aqueous acid solution as described above or separately performing film hardening treatment by another method.

It is preferable to add a step of rinsing with a dilute aqueous acid solution after the development with the aqueous boric acid solution, because the pattern formation can be more effectively performed.

From the above, when the pattern forming method of the present invention is used, for example, in the production of a shadow mask for a color cathode ray tube, an IC lead frame, a mesh for a fluorescent display tube, etc., a substrate is prepared by using this photocurable pattern as an etching mask. In the case of etching, it is possible to perform etching with high processing accuracy that is faithful to the mask pattern. Ferric chloride solution and cupric chloride solution are usually used as the etching solution, but other metals such as chlorides of Mg, Ca, Sr, Ba, Zn, Co, Mn and ammonium, and nitrate solutions are used. It can also be used (acidic etching). When etching copper foil such as in printed circuits, cupric chloride solution is often used, and when etching lead frames, shadow masks, fluorescent display tube meshes, etc., ferric chloride solution may be used. Many. The water-soluble photosensitive resin composition of the present invention has excellent resistance to such an acidic etching solution.

When the etching is completed, the step of removing the resist film is started. The photocurable pattern obtained by the present invention is
Since it is easily soluble in a concentrated alkaline aqueous solution, it has good dissolution and releasability, and the peeled resist does not re-adhere. Furthermore, for example, it can be dissolved and peeled more easily by immersing it in a 5 to 20% sodium hydroxide aqueous solution heated to 40 ° C. or higher, and it is more preferable to add sodium gluconate of several% to the above aqueous solution.

Since the water-soluble photosensitive resin layer of the present invention contains casein, it has good adhesion to the substrate. Further, by selecting another monomer to be copolymerized, it is possible to further improve the adhesion to the substrate by modifying the polymer such as acetalization.

[0045]

EXAMPLES Examples of the present invention will be described below.
The present invention is not limited to this.

I. Water-Soluble Photosensitive Resin Composition Synthesis Example 1 Synthesis of Water-Soluble Polymer (Base Polymer) 230 g of dimethyl acrylamide, 260 g of diacetone acrylamide, and 6510 g of pure water were charged into a flask,
This was heated while bubbling with nitrogen.

When the temperature reached 65 ° C., the feeding of nitrogen was stopped, 100 g of isopropyl alcohol (IPA) was injected, and 2,2'-azobis [2- (2'-imidazoline-2- Il) propane] dibasic acid (“VA-044”; manufactured by Wako Pure Chemical Industries, Ltd.) 40 g
What was melt | dissolved in 200 g of water was inject | poured, and it stirred under recirculation | reflux for 1 hour. Then, the mixture was cooled with water, the supernatant was discarded at a temperature of 70 ° C., about 2000 g of pure water was added, and the mixture was cooled to 20 ° C. Then, the reaction product was taken out from the flask and further diluted with pure water to give a weight average molecular weight of 23 × 10 ⁴ (D
MF method, polystyrene standard), dispersity 1.6, viscosity 13
About 3300 g of a water-soluble polymer (base polymer) liquid having a mPa · s / 25 ° C. and a concentration of 12.12% was obtained.

Synthesis Example 2 Synthesis of Photopolymer 500 g of the base polymer solution obtained in Synthesis Example 1 was diluted by adding pure water to make a total of 865 g. To this, 45 g of sodium 4-azidobenzaldehyde-2-sulfonate was added, stirred and dissolved (liquid temperature 17 ° C.). 6 ml of a 5% aqueous sodium hydroxide solution was added thereto, reacted for 3 days, neutralized with diluted hydrochloric acid, further diluted with pure water, and filtered to obtain a photopolymer solution having a concentration of 9.5%.

[Measurement of Sensitivity] The photopolymer solution (reaction stock solution) obtained in Synthesis Example 2 was diluted twice with pure water, coated on an aluminum plate and dried to form a dry film of 1 μm. The sensitivity of this was measured by the gray scale method. That is, a gray scale (Kodak Photogr
apic Step Tablet No. 2) was brought into close contact, exposed to 10 mJ / cm ² with an ultrahigh pressure mercury lamp, and then developed by pouring pure water. After dyeing with a methyl violet aqueous solution, washed with water and dried,
A sensitivity of 15 steps was obtained.

Synthesis Example 3 Water-soluble polymer (base poly
A) Acryloylmorpholine (437 g), diacetone acrylamide (263 g), and pure water (6300 g) were charged into a flask,
This was heated while bubbling with nitrogen.

When the temperature reached 65 ° C., the feeding of nitrogen was stopped, 100 g of IPA was injected, and 40 g of “VA-044” as a polymerization initiator dissolved in 300 g of water was injected. Ten minutes after the polymerization initiator was injected, the mixture was heated to 80 ° C. and stirred at that temperature for 1 hour. Then, the mixture was cooled with water, the supernatant was discarded at a temperature of 70 ° C., about 3500 g of pure water was added, and the mixture was cooled to 20 ° C. Then, the reaction product was taken out from the flask and further diluted with pure water to have a weight average molecular weight of 21 × 10 ⁴ (DM
Method F, polystyrene standard), dispersity 1.75, viscosity 10
6700 g of a water-soluble polymer (base polymer) liquid having a mPa · s / 25 ° C. and a concentration of 7.0% was obtained.

Synthesis Example 4 Synthesis of Photopolymer 4-1000 g of the base polymer liquid obtained in Synthesis Example 3
33 g of sodium azidobenzaldehyde-2-sulfonate was added, stirred and dissolved (liquid temperature 10 ° C.). 7 ml of a 5% aqueous sodium hydroxide solution was added thereto, and the mixture was reacted for 2 days, neutralized with dilute hydrochloric acid, further diluted with pure water, and filtered to obtain a photopolymer solution having a concentration of 10.0%.

[Sensitivity Measurement] The sensitivity of the photopolymer solution obtained in Synthesis Example 4 was measured in the same manner as the sensitivity measurement of the photopolymer solution prepared in Synthesis Example 2, and 16 steps of sensitivity were obtained.

Synthesis Example 5 Synthetic casein solution of Sample 1 ("G-90W"; Tokyo Ohka Kogyo Co., Ltd.)
(Produced, containing 12.07% by weight of casein), 240 g of the photopolymer solution obtained in Synthesis Example 2 was added and mixed. To this, 400 g of pure water was added and stirred to obtain a water-soluble photosensitive resin composition (Sample 1) having a solid content of about 10%.

Synthesis Example 6 Synthetic casein solution of Sample 2 ("G-90W"; Tokyo Ohka Kogyo Co., Ltd.)
(Produced, containing 12.07% by weight of casein), 320 g of the photopolymer solution obtained in Synthesis Example 2 was added and mixed. To this, 400 g of pure water was added and stirred to obtain a water-soluble photosensitive resin composition (Sample 2) having a solid content of about 10%.

Synthesis Example 7 Synthetic casein solution of Sample 3 ("G-90W"; Tokyo Ohka Kogyo Co., Ltd.)
(Produced, containing 12.07% by weight of casein), 380 g of the photopolymer solution obtained in Synthesis Example 2 was added and mixed. To this, 390 g of pure water was added and stirred to obtain a water-soluble photosensitive resin composition (Sample 3) having a solid content of about 10%.

Synthesis Example 8 Synthetic casein solution of Sample 4 ("G-90W"; Tokyo Ohka Kogyo Co., Ltd.)
50 g of the photopolymer solution obtained in the above Synthesis Example 2 was added to and mixed with 1000 g of casein (containing 12.07% by weight of casein). To this, add 410 g of pure water and stir to obtain a solid content of about 1
A 0% water-soluble photosensitive resin composition (Sample 4) was obtained.

Synthesis Example 9 Synthetic casein solution of Sample 5 ("G-90W"; Tokyo Ohka Kogyo Co., Ltd.)
(Produced, containing 12.07% by weight of casein), 510 g of the photopolymer solution obtained in Synthesis Example 2 was added and mixed. To this, 385 g of pure water was added and stirred to obtain a water-soluble photosensitive resin composition (Sample 5) having a solid content of about 10%.

Synthesis Example 10 Synthetic casein solution of Sample 6 ("G-90W"; Tokyo Ohka Kogyo Co., Ltd.)
(Produced, containing 12.07% by weight of casein), 13 g of the photopolymer solution obtained in Synthesis Example 2 was added and mixed. To this, add 410 g of pure water and stir to obtain a solid content of about 1
A 0% water-soluble photosensitive resin composition (Sample 6) was obtained.

Synthesis Example 11 Synthetic casein solution of Sample 7 ("G-90W"; Tokyo Ohka Kogyo Co., Ltd.)
(Manufactured by, and containing 12.07% by weight of casein), 630 g of the photopolymer solution obtained in Synthesis Example 2 was added and mixed. To this, 380 g of pure water was added and stirred to obtain a water-soluble photosensitive resin composition (Sample 7) having a solid content of about 10%.

Synthesis Example 12 Synthetic casein solution of Sample 8 ("G-90W"; Tokyo Ohka Kogyo Co., Ltd.)
(Produced, containing 12.07% by weight of casein), 240 g of the photopolymer solution obtained in Synthesis Example 4 was added and mixed. To this, 410 g of pure water was added and stirred to obtain a water-soluble photosensitive resin composition (Sample 8) having a solid content of about 10%.

Synthesis Example 13 Synthetic casein solution of Sample 9 ("G-90W"; Tokyo Ohka Kogyo Co., Ltd.)
(Produced, containing 12.07% by weight of casein), 300 g of the photopolymer solution obtained in Synthesis Example 4 was added and mixed. To this, 410 g of pure water was added and stirred to obtain a water-soluble photosensitive resin composition (Sample 9) having a solid content of about 10%.

Synthesis Example 14 Synthetic casein solution of Sample 10 ("G-90W"; Tokyo Ohka Kogyo Co., Ltd.)
(Produced, containing 12.07% by weight of casein), 360 g of the photopolymer solution obtained in Synthesis Example 4 was added and mixed. To this, 410 g of pure water was added and stirred to obtain a water-soluble photosensitive resin composition (Sample 10) having a solid content of about 10%.

Synthesis Example 15 Synthetic casein solution of Sample 11 ("G-90W"; Tokyo Ohka Kogyo Co., Ltd.)
(Produced, containing 12.07% by weight of casein), 50 g of the photopolymer solution obtained in Synthesis Example 4 was added and mixed. To this, add 410 g of pure water and stir to obtain a solid content of about 1
A 0% water-soluble photosensitive resin composition (Sample 11) was obtained.

Synthesis Example 16 Synthetic casein solution of Sample 12 ("G-90W"; Tokyo Ohka Kogyo Co., Ltd.)
(Produced, containing 12.07% by weight of casein), 480 g of the photopolymer solution obtained in Synthesis Example 4 was added and mixed. To this, 410 g of pure water was added and stirred to obtain a water-soluble photosensitive resin composition (Sample 12) having a solid content of about 10%.

Comparative Synthetic Example A synthetic casein solution of a comparative sample (“G-90W”; Tokyo Ohka Kogyo Co., Ltd.)
1000 g of casein (containing 12.07% by weight), bisazide (4,4′-diazidostilbene-2,2′-)
15 g of sodium disulfonate) was added and dissolved to obtain a water-soluble photosensitive resin composition (comparative sample).

II. Pattern Forming Example 1, Comparative Example 1 (Post-exposure Dilute Acid Immersion) A steel plate (125 × 125 mm) for a shadow mask was used as a substrate, degreased, washed with water and dried, and then the above Samples 1 to 12 and Comparative Sample, respectively. It was spin-coated at 150 rpm and dried at 50 ° C. for 10 minutes to form a photoresist layer (film thickness 2 μm).

A negative mask having a predetermined pattern is brought into close contact with the photoresist layer and exposed to 200 m with an ultrahigh pressure mercury lamp.
Exposure was performed with a light amount of J / cm ² .

After the exposure, it is immersed in any one of the following dilute acid aqueous solutions shown below for 10 to 30 seconds and then washed with water to obtain 50.
It was dried with hot air at 10 ° C for 10 minutes.

Then, (i) 0.05% aqueous ammonia solution or (ii) 0.2% aqueous sodium hydrogen carbonate solution was used for spray development to dissolve and remove the unexposed portion.

Dilute acid aqueous solution: 0.2% acetic acid aqueous solution 0.2% oxalic acid aqueous solution 0.2% citric acid aqueous solution 0.2% tartaric acid aqueous solution 0.2% malic acid aqueous solution 0.2% phosphoric acid aqueous solution 0.2 % Sulfamic acid aqueous solution As a result, in the case of using Samples 1 to 5 and Samples 7 to 12, among the samples subjected to the dipping treatment in the above dilute aqueous acid solutions, a slightly undeveloped pattern was left in the combined treatment of-(ii). However, in all other cases, no swelling or washout of the pattern was observed during the development of any of (i) and (ii) above, and a photo-cured pattern faithful to the mask pattern was formed. I was able to.

When the sample 6 is used, the above (i), (i
In any of the developments of i), although a part of the photo-cured portion was washed away, a photo-cured pattern that was almost faithful to the mask pattern could be formed.

On the other hand, in the case of using the comparative sample, the dipping treatment was carried out in the same manner in the dilute aqueous acid solution, but the pattern swelled and flowed down during development.

Next, the photo-cured pattern obtained by using Samples 1 to 12 formed on the shadow mask steel plate was heated at 200 ° C. for 10 minutes (post-baking).
Then, spray etching was performed for 15 minutes using an etching solution composed of a ferric chloride solution of 45Be '(Baume degree) and 50 ° C, and subsequently immersed in an aqueous sodium hydroxide solution of 40% at a concentration of 10%. The photo-curing patterns of Samples 1 to 6 and Samples 8 to 12 were completely dissolved and removed from the substrate. Further, the photo-curing pattern made of Sample 7 was completely peeled off from the substrate. After that, each substrate was washed with water and dried, and as a result, no residue was found on the substrate, and no defect in the wiring pattern due to etching failure was found.

Example 2, Comparative Example 2 (Pre-exposure Dilute Acid Immersion) In the same manner as in Example 1, Samples 1 to 12 and Comparative Sample were used to form a photoresist layer (film thickness 2 μm) on a shadow mask steel plate. Formed.

This was dipped in any one of the above dilute aqueous acid solutions of 1 to 10 shown in Example 1, washed with water, and dried with hot air at 50 ° C. for 10 minutes.

Then, a negative mask having a predetermined pattern was adhered to the photoresist layer, and the negative mask was exposed to light with an ultrahigh pressure mercury lamp.
After exposure with a light amount of 00 mJ / cm ² , spray development is performed using a 0.2% sodium hydrogen carbonate aqueous solution,
The unexposed part was removed.

As a result, samples 1-5 and samples 7-1
When 2 is used, any of the above dipping treatments with dilute acid aqueous solution does not show swelling or washout of the pattern at the time of development by dilute alkali development, and a photo-curing pattern faithful to the mask pattern is obtained. Could be formed.

In Sample 6, although it was confirmed that the photo-cured part was partially washed away during the development of any of (i) and (ii), a photo-cured pattern that was almost faithful to the mask pattern could be formed. did it.

On the other hand, when the comparative sample was used, the pattern swelled and flowed down from the substrate, and the pattern could not be formed.

Next, the photo-cured pattern obtained by using the above Samples 1 to 12 formed on the steel plate for the shadow mask was heated at 200 ° C. for 10 minutes (post-baking).
Then, spray etching was performed for 15 minutes using an etching solution composed of a ferric chloride solution of 45Be '(Baume degree) and 50 ° C, and subsequently immersed in an aqueous sodium hydroxide solution of 40% at a concentration of 10%. The photo-curing patterns of Samples 1 to 6 and Samples 8 to 12 were completely dissolved and removed from the substrate. Further, the photo-curing pattern made of Sample 7 was completely peeled off from the substrate. After that, each substrate was washed with water and dried, and as a result, no residue was found on the substrate, and no defect in the wiring pattern due to etching failure was found.

Example 3, Comparative Example 3 (Boric Acid Aqueous Solution Development) In the same manner as in Example 1, after forming a photoresist layer (film thickness 2 μm) on a steel plate for a shadow mask, a predetermined pattern was formed on this photoresist layer. The negative mask was held in close contact with the mask and exposed with an ultrahigh pressure mercury lamp at a light amount of 200 mJ / cm ² .

The exposed substrate was immersed in a 1% aqueous boric acid solution as a developing solution for 30 seconds, washed with water and dried.

As a result, Samples 1 to 5 and Samples 7 to 12
In the case of using, the pattern swelling, the washout, etc. were not observed at all, and a photo-curing pattern faithful to the mask pattern was obtained.

When Sample 6 was used, although a part of the photo-cured portion was washed away, a photo-cured pattern that was almost true to the mask pattern could be formed.

On the other hand, when the comparative sample was used, the pattern swelled during development and flowed off.

After development with the 1% aqueous solution of boric acid and washing with water, the product was washed with dilute aqueous acid solution (0.2% aqueous acetic acid solution) to obtain 1
After rinsing for 0 second, followed by washing with water and drying, it was possible to form a photo-cured pattern with high processing accuracy that was faithful to the mask pattern.

Next, the photo-cured pattern obtained by using the above samples 1 to 12 formed on the steel plate for shadow mask was heated at 200 ° C. for 10 minutes (post-baking).
Then, spray etching was performed for 15 minutes using an etching solution composed of a ferric chloride solution of 45Be '(Baume degree) and 50 ° C, and subsequently immersed in an aqueous sodium hydroxide solution of 40% at a concentration of 10%. The photo-curing patterns of Samples 1 to 6 and Samples 8 to 12 were completely dissolved and removed from the substrate. Further, the photo-curing pattern made of Sample 7 was completely peeled off from the substrate. After that, each substrate was washed with water and dried, and as a result, no residue was found on the substrate, and no defect in the wiring pattern due to etching failure was found.

[0089]

As described in detail above, according to the present invention, the etching resistance is excellent, the sensitivity is high, the resolution is good, the storage stability is good, and the adhesion to the substrate is excellent. A water-soluble photosensitive resin composition that can be peeled off is provided, and using this, a photo-curing pattern that is safe in terms of environmental protection and that is faithful to a mask pattern without pattern swelling or washout during development is formed. An effect is provided that a pattern forming method that can be performed is provided.

Claims (4)

[Claims] 1. Casein and the following chemical formula 1 A water-soluble photosensitive resin composition comprising a polymer compound having a structural unit represented by the formula (wherein X represents Na, K or NH ₄ ). 2. The water-soluble photosensitive resin composition according to claim 1 is applied onto a substrate, which is then brought into contact with a dilute aqueous acid solution,
A pattern forming method comprising forming a photo-cured pattern on a substrate by selectively exposing through a mask pattern and then developing with a dilute alkaline aqueous solution to remove the unexposed portion. 3. The water-soluble photosensitive resin composition according to claim 1 is applied onto a substrate, which is selectively exposed through a mask pattern, and then contacted with a dilute acid aqueous solution, and then with a dilute alkaline aqueous solution. A pattern forming method, wherein a photo-cured pattern is formed on a substrate by developing and removing an unexposed portion. 4. The water-soluble photosensitive resin composition according to claim 1 is applied onto a substrate, selectively exposed through a mask pattern, and then developed with an aqueous boric acid solution to remove an unexposed portion. A pattern forming method for forming a photo-cured pattern on a substrate by performing the method.