KR20060101811A - Negative type liquid photoresist composition for display electrode - Google Patents

Abstract

The present invention relates to a liquid negative photoresist composition for forming a display electrode, and specifically, contains a modified epoxy acrylate resin in a binder resin molecular structure, and in addition, a monomer, a photosensitizer, a photosensitization aid, and an additive are added to the storage stability. It is excellent in this, and it is about the composition which was excellent in the precision of a pattern by showing sufficient etching resistance even after etching, without damaging a pattern also in each process, such as drying, exposure, image development, etching, and peeling.

In addition, the present invention relates to a method of forming electrode patterns on the front and rear substrates of a plasma display panel (PDP) using the composition.

Liquid Negative Photoresist Composition for Display Electrode Formation

Description

Liquid negative photoresist composition for forming display electrodes {NEGATIVE TYPE LIQUID PHOTORESIST COMPOSITION FOR DISPLAY ELECTRODE}

1 is a perspective view showing a schematic structure of a conventional surface discharge type AC plasma display panel.

<Explanation of symbols for the main parts of the drawings>

1. Glass Substrate

2. Transparent electrode

3. bus electrode

4. Dielectric layer

5. MgO

6. Phosphor

7. Bulkhead

8. Address electrode

2A through 2F are cross-sectional views illustrating a step of manufacturing a transparent electrode pattern during a front substrate structure manufacturing process according to the present invention.

The present invention relates to a liquid negative photoresist composition for forming a display electrode, and specifically, contains a modified epoxy acrylate resin in a binder resin molecular structure and, in addition, a monomer, a photosensitizer, a photosensitizer, an additive, and the like to preserve storage stability. It is excellent in this, and it is about the composition which was excellent in the precision of a pattern by showing sufficient etching resistance even after etching, without damaging a pattern also in each process, such as drying, exposure, image development, etching, and peeling.

In addition, the present invention relates to a method of forming an electrode pattern on a substrate of a plasma display panel (hereinafter, abbreviated as PDP) using the composition.

In general, in forming a film pattern of a PDP electrode circuit, conventionally, a dry film resist (DFR) is used. As the binder resin of the DFR, a photocurable composition of a binder polymer having a copolymer of methyl methacrylate and styrene as a main chain was used, which may cause problems on a large screen device (exposure, laminator) in the production of PDP, The resolution is limited due to process problems due to the process and scattering of light due to the upper and lower layers of the DFR.

The present invention has been proposed to solve the problems of the prior art, and an object of the present invention is to use a liquid photoresist instead of paste to replace DFR and to contain a modified epoxy acrylate resin in a binder resin molecular structure. In addition, monomers, photosensitizers, photosensitization aids, and additives are added to provide excellent storage stability, and the patterns are not damaged even during drying, exposure, development, etching, and peeling, and exhibit sufficient etching resistance even after etching. It is to provide a liquid negative photoresist composition for forming a display electrode having excellent precision.

It is still another object of the present invention to provide a method of forming an electrode pattern of an electrode substrate having an improved PDP electrode formation profile using the liquid negative photoresist for forming the display electrode.

In order to achieve the above object, the present invention provides a liquid negative photoresist composition for forming a display electrode comprising the following components (A) to (E):

(A) 30 to 60% by weight of the modified epoxy acrylate resin obtained by the production method comprising the following steps;

(a) As the reaction catalyst, one selected from the group consisting of triphenylphosphine, triethylamine, benzyldimethylamine, methyltriethylammonium chloride, chromium octanoate and zirconium octanoate is 0.1 to the total weight of the reaction mixture. To 1% by weight, in an organic solvent at a temperature of 90 to 110 ° C, the epoxy compound of formula (I) and acrylic acid of formula (II) are 0.8 to 1.2 moles of acrylic acid, preferably 1 equivalent of epoxy group. Reacting at a reaction ratio of 1 mol to obtain an epoxy acrylate of the following general formula (III); And

(I)

(I)

(Wherein R ₁ is H or 1CH ₃ , n is an integer from 1 to 7)

(II)

(II)

(III)

(III)

(Wherein R ₁ is as defined in formula (I))

(b) 0.8 to 1.2 moles of phthalic anhydride, preferably 1% of the reaction product of step (a) and tetrahydrophthalic anhydride of formula (IV) to one equivalent of hydroxy group of formula (III) at a temperature of 70 to 90 ° C. Reacting at a reaction ratio of 1 mole to obtain a compound of formula (V) having a phthalic acid residue introduced at the terminal or side chain thereof.

(IV)

(IV)

(V)

(V)

(B) 1 to 20% by weight radical photopolymerization initiator comprising at least one photosensitizer and photosensitization aid;

(C) 2 to 30% by weight of a monomer having a radical polymerizable double bond in the molecule;

(D) 0.1 to 2 weight percent antifoam; And

(E) 0.1 to 2% by weight leveling agent.

(Adding an organic solvent to the total 100% by weight, the organic solvent is used in an amount of 1 to 50% by weight relative to the total weight of the component (A))

Hereinafter, the present invention will be described in detail.

The epoxy compound used in the above step (a) is an epoxy phenol novolak resin (when R ₁ is H) or an epoxy cresol novolak resin (when R ₁ is -CH ₃ in formula), and an epoxy equivalent weight 200-230 and a softening point of 75-85 degreeC are used. For example, YDCN-500-90P (National Chemical Epoxy), N-680 (manufactured by LG Chemical), EOCN-103S (manufactured by NIPPON KAYAKU), or ECN-1280 (manufactured by Shiva-Geigi) can be used.

As the reaction solvent, butyl carbitol acetate, methyl ethyl ketone, cyclohexanone, toluene, dipropylene glycol dimethyl ether, ethyl acetate, butyl cellosolve acetate, petroleum ether, etc. can be used. It is used in the amount of 1-50 weight% with respect to the total weight of (A) component.

The polymerization inhibitor is used for the purpose of delaying or preventing polymerization by heat and light, and specific examples thereof include methylethyl hydroquinone, hydroquinone, methylhydroquinone, catechol, pyrogallol, and the like. , Based on the total weight of component (A), in an amount of 100 to 400 ppm, preferably 200 ppm. When the polymerization inhibitor is used at less than 100 ppm, gelation by the addition reaction may proceed rapidly, and when it is used in excess of 400 ppm, it may cause a poor sensitivity in the evaluation of the photoresist.

The photosensitizer is a compound that generates radicals when exposed to active light such as ultraviolet rays or visible light, and specific examples include benzoin-based sensitization such as benzoin, benzoin methyl ether, benzoin benzopropyl ether and a-acrylbenzoin. My; Aryl ketone sensitizers such as benzophenone, p-methylbenzophenone, p-chlorobenzophenone, tetrachlorobenzophenone and acetone benzo; Dialkylaminoaryl ketone sensitizers such as 4,4′-bisdiethylaminobenzophenone and p-dimethylaminoacetonephenone; Polyvalent carbonyl sensitizers such as halogen substituents such as thioxanthone, xanthone and 2-chlorothioxanthone; IRGACURE 907 etc. can be used and can be used individually or in combination of 2 or more types. The blending ratio of such a photosensitizer is suitable 8 to 40 parts by weight, preferably 4 to 25 parts by weight per 100 parts by weight.

The photosensitizer may be used to increase the activity of the photosensitizer. Examples of the photosensitizer include a benzophenone series, a benzoin methyl ether series, or a tetraethyl thiuran disulfide series, with a blending ratio of 4 to 20 parts by weight per 100 parts by weight, preferably. Is 2 to 10 parts by weight.

The monomer having a radically polymerizable double bond in the molecule is for imparting etch resistance and solvent resistance to the cured resist film, and in the photocurable composition of the present invention, photopolymerization is used to improve the photocurability of the composition and improve developability. Used for As this photopolymerizable monomer, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, diethylene glycol diacrylate, trimethylol propane triacrylate, pentaerythritol triacrylate, pentaerythritol Tetraacrylate, trimethylolpropane ethylene oxide modified triacrylate, trimethylolpropanepropylene oxide modified triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate and each meta corresponding to the acrylate Acrylates; Mono-, di-, tri- or more polyesters of polybasic acids such as phthalic acid, adipic acid, maleic acid, itaconic acid, succinic acid, trimellitic acid and terephthalic acid with hydroxyalkyl (meth) acrylates. However, it is not limited to a specific thing and can also use these individually or in combination of 2 or more types. Among these photopolymerizable monomers, polyfunctional monomers having two or more acryloyl groups or methacryloyl groups in one molecule are preferable. The amount of such photopolymerizable monomer is 2 to 30 parts by weight per 100 parts by weight of the organic binder. When the amount of the photopolymerizable monomer is less than the above range, the composition hardly obtains sufficient photocurability, while when the amount exceeds the above range, hardening stains tend to occur because the photocuring of the surface portion is faster than the deep portion of the coating.

The antifoaming agent is added in order to facilitate miscibility in the preparation of the photosensitive resin composition and to reduce defects caused by pinhole generation and film nonuniformity in the process of producing a thick film. Specific examples thereof include anionic copolymers, allylalkyl-modified polymethylalkylsiloxanes, polyester-modified polymethylalkylsiloxanes, polysiloxane-based, non-silicone-based polymer mixtures, modified urea solutions, polyester-modified dimethylpolysiloxanes, polyesters And modified dimethylpolysiloxane copolymers. The amount of the antifoaming agent is preferably 0.1 to 7% by weight, more preferably 1 to 5% by weight based on the total weight of the composition. When the content of the antifoaming agent exceeds 7% by weight, it is easy to cause the residual film to remain during the developing process, and when the content is less than 0.1% by weight, it is difficult to expect the property.

Leveling agent is to improve the flatness and unevenness when applying the resist as a specific example of the silicone type or fluorine-based type, the content is preferably used 1 to 2% by weight based on the total weight of the composition.

As a solvent which melt | dissolves the alkali-soluble novolak resin, crosslinking agent, etc. of this invention, Ethylene glycol monoalkyl ethers, such as ethylene glycol monomail ether and ethylene glycol monoethyl ether; Ethylene glycol monoalkyl ether acetates such as ethylene glycol monomethyl ether acetate and ethylene glycol monoethyl ether acetate; Propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monoethyl ether acetate; Lactic acid esters such as methyl lactate and ethyl actate; Aromatic hydrocarbons such as toluene and xylene; Ketones such as methyl ethyl ketone, 2-heptanone and cyclohexanone; Amides such as N, N-dimethylacetamide and N-methylpyrrolidone; Lactones, such as (gamma) -butyrolactone, etc. are mentioned. These solvents are used individually or in mixture of 2 or more.

Hereinafter, the present invention will be described with reference to the following examples, but the present invention is not limited thereto.

<Examples 1 to 6>

Preparation of Modified Epoxy Acrylate Resin (DWEA)

While injecting nitrogen, 210 g of YDCN-500-90P (epoxy cresol novolak resin, manufactured by Kukdo Epoxy), 200 g of butylcarbitol acetate, and 1 g of hydroquinone were placed in a reaction vessel, heated and stirred at 80 ° C. for 1 hour to uniform contents. Mixed well. 1 g of triethylamine was added thereto, and 72 g of acrylic acid was added thereto while maintaining at 90 ° C. for 2 to 4 hours.

When acrylic acid is added, the epoxy ring opens and a serious exotherm starts. When a sudden exotherm occurs, it is cooled by quenching.

After the reaction was completed, the reaction product was cooled to room temperature, and then, 152 g of tetrahydrophthalic anhydride and 100 g of butylcarbitol acetate were added thereto, followed by reaction for 1 hour while maintaining the reaction temperature at 100 to 110 ° C., at 1780.1850 cm ⁻¹ . After confirming that there is no absorption peak of the anhydride functional group, the temperature of the reactant is quenched to room temperature to obtain a modified epoxy acrylate resin (DWEA).

Preparation of the composition of the present invention

To the resin prepared above, a composition was prepared in which the following components were mixed as shown in Table 1 below, and the usefulness of the composition of the present invention was tested for sensitivity, adhesion, and chemical resistance as follows.

Example DWEA / TMPTA / I-907 / DETX / EA / Silicone (% by weight) Sensitivity (msec) Adhesion Chemical resistance One 50/26/6/2/14/2 130 O O 2 50/22/9/3/14/2 120 O O 3 50/18/12/4/14/2 120 O O 4 45/19/15/5/14/2 95 O O 5 41/19/18/6/14/2 80 △ O 6 37/19/21/7/14/2 70 △ O

* Additives: antifoaming agent, leveling agent.

* DWEA: Dongwoo epoxy acrylate resin

* TMPTA: trimethyl propane triacrylate

* DETX: 2,4-diethyl thioxanthone

* EA: Ethylene Glycol Monomethyl Ether Acetate

* Adhesion and chemical resistance results are represented by O: good, △: normal, X: bad.

<Sensitivity measurement>

After the negative photoresist was applied to the silicon wafer, a g-line stepper was used to measure the exposure amount when the width of the post-exposure mask pattern and the width of the pattern of the actually cured photoresist were the same.

<Measurement of adhesion>

According to JIS D 0202, the photoresist is applied on a glass substrate or glass on which ITO is deposited, then the entire exposure is performed at an appropriate exposure amount. After forming 100 gratings, the number of gratings remaining when 3M Scotch tape is pressed and detached is determined. The measurement was made at "100" when "100", "△" when 80/100 to 99/100, and "X" when less than 80/100.

<Measurement of chemical resistance>

Tape test was performed after 40 minutes of immersion in N-methylpyrrolidone (NMP) at a temperature of 40 ℃.

As shown in the experimental results in Table 1, the composition prepared by the present invention shows excellent sensitivity, adhesion, chemical resistance, it can be seen that the precision and sensitivity of the pattern when forming the electrode.

The present invention also provides a method for forming a transparent electrode pattern of an electrode substrate having an improved PDP electrode formation profile using the liquid negative photoresist composition for forming the display electrode.

Method for forming a transparent electrode pattern of the electrode substrate according to the present invention,

(1) depositing a transparent electrode material on the front and back substrates and applying a photoresist thereon;

(2) laminating the photocurable composition and drying it to prepare a viscous-free film;

(3) exposing the photoresist and prebaking it;

(4) developing the photoresist with an alkaline developer to form a mask pattern and postbaking it; And

(5) Comprising a step of completing the electrode pattern through the selective etching using the mask pattern.

The method will be described in detail with reference to the drawings.

First, as shown in FIGS. 2A to 2F, a transparent electrode material is applied to the entire surface of the front substrate 100 and patterned to form a transparent electrode pattern on a stripe. At this time, the transparent electrode pattern is formed of an ITO film or a SnO film.

A specific method of forming the film is first depositing the ITO film 110 on the front substrate 100 as shown in FIG. 2A and then photoresist on the ITO film 110 as shown in FIG. 2B. Apply 120.

The photocurable composition of the present invention may be laminated on a substrate when the film is prepared in a film form in advance, but in the case of a paste composition or a liquid, it may be applied by a suitable method such as a screen printing method, a bar coater, a bleed coater, or a spin coater. In order to obtain the touch drying property, the film is dried for 5 to 30 minutes at, for example, about 60 to 120 ° C. in a hot air circulation drying furnace, a far-infrared drying furnace, or the like to evaporate an organic solvent. Get a (tacky free) coating.

Next, as shown in Fig. 2C, the photoresist 120 is exposed.

As an exposure process, contact exposure and non-contact exposure using the negative mask which has a predetermined exposure pattern are possible. As the exposure light source, halogen lamps, high pressure mercury lamps, laser lights, metal halogen lamps, black lamps, electrodeless lamps and the like are used. As an exposure amount, about 50-1000 mJ / cm <^2> is preferable.

Thereafter, prebaking is performed at a temperature of about 90 ° C. Next, as shown in FIG. 2D, the photoresist 120 is developed with an alkaline developer to form a mask pattern 130.

As the developing step, a spray method, an immersion method, or the like is used. As a developing solution, aqueous metal alkali solutions, such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, and sodium silicate, and aqueous amine solutions, such as monoethanolamine, diethanolamine, and triethanolamine, especially the dilute alkali aqueous solution of the density | concentration of about 1.5 mass% or less Although this is suitably used, the carboxyl group of the carboxyl group-containing resin in the composition may be saponified to remove the uncured portion (the unexposed portion), and is not limited to the developer as described above. In addition, it is preferable to wash with water or acid neutralize to remove unnecessary developer after development.

Next, post-baking is performed at a temperature of about 120 ° C. Next, as shown in FIG. 2E, the ITO film 110 (see FIG. 2A) is selectively etched using the mask pattern 130 to form the electrode pattern 140, and as shown in FIG. 2F, The ITO electrode pattern 140 is completed by removing the mask pattern 130.

In addition, using the above-described method, a photoresist coated with a thick film (200 μm) may be exposed to a lower portion by one exposure, and may have an excellent line width in the range of 30 to 100 μm.

In addition, the liquid negative photoresist composition for forming a display electrode of the present invention can be suitably used for structural materials of LCD panels such as spacers, electrodes such as organic EL displays, BM and partition materials. Conventionally, particles of silica or plastic have been used as spacers, but it is not desirable to have a spacer in a dot in view of deterioration of image quality, and a pillar should be placed in a part without dots in a panel instead of scattering particles. There is also a method of making a spacer so as to stand (post spacer), and as such a post spacer, the negative photosensitive resin composition of the present invention can be suitably used. In the organic EL display, application of the three-color independent emission type RGB organic EL media and electrode formation are performed, but the liquid negative photoresist composition for forming the display electrode of the present invention having heat resistance can be effectively used as the cathode partition material. Can be.

As described above, by proceeding the pre-process for fabricating the front substrate structure of the plasma display panel with a liquid negative type photoresist, which is a liquid negative photoresist composition for forming a display electrode according to the present invention, instead of DFR, The lamination process, which is a problem caused by large screen implementation, can be replaced, and it can be formed without using a laminator, which becomes a problem such as power and installation area in mass production. In addition, by using the photolithographic process, a good pattern with high sensitivity and high resolution can be formed, and a negative composition having a small process dependence of dimensional accuracy can be obtained, and in particular, PDP is excellent because of excellent etching resist required for fabrication of a plasma display panel. It can use suitably for a transparent electrode material and a partition material.

Claims (7)

Liquid negative photoresist composition for forming a display electrode comprising: (A) 30 to 60% by weight of modified epoxy acrylate resin; (B) 1 to 20% by weight radical photopolymerization initiator comprising at least one photosensitizer and photosensitization aid; (C) 2 to 30% by weight of a monomer having a radical polymerizable double bond in the molecule; (D) 0.1 to 2 weight percent antifoam; And (E) 0.1 to 2% by weight leveling agent. (Adding an organic solvent to 100% by weight, the organic solvent is used in an amount of 1 to 50% by weight relative to the total weight of component (A)). The composition of claim 1, wherein the modified epoxy acrylate resin is obtained by a manufacturing method comprising the following steps: (a) As the reaction catalyst, one selected from the group consisting of triphenylphosphine, triethylamine, benzyldimethylamine, methyltriethylammonium chloride, chromium octanoate and zirconium octanoate is added to the total weight of the reaction mixture. 0.1 to 1% by weight of the epoxy compound of formula (I) and acrylic acid of formula (II) are 0.8 to 1.2 moles of acrylic acid, preferably 1 equivalent of epoxy group, at a temperature of 90 to 110 캜 in an organic solvent. Reacting at a reaction ratio of 1 mol to obtain an epoxy acrylate of the following general formula (III); And [Formula 1]

(I) (Wherein R ₁ is H or 1CH ₃ , n is an integer from 1 to 7) [Formula 2]

(II) [Formula 3]

(III) (Wherein R ₁ is as defined in formula (I)) (b) 0.8 to 1.2 moles of phthalic anhydride, preferably 1% of the reaction product of step (a) and tetrahydrophthalic anhydride of formula (IV) to one equivalent of hydroxy group of formula (III) at a temperature of 70 to 90 ° C. Reacting at a reaction ratio of 1 mole to obtain a compound of formula (V) having a phthalic acid residue introduced at the terminal or side chain thereof. [Formula 4]

(IV) [Formula 5]

(V) A method of forming an electrode pattern of an electrode substrate using the composition according to claim 1, comprising the following steps; (1) depositing electrode material on front and back substrates and applying photoresist thereon; (2) laminating the photocurable composition and drying it to prepare a viscous-free film; (3) exposing the photoresist and prebaking it; (4) developing the photoresist with an alkaline developer to form a mask pattern and postbaking it; And (5) completing the electrode pattern by selective etching using the mask pattern. The method of claim 3, wherein in step (2), the photocurable composition is laminated using a screen, a bar coater, or a bleed coater printing method. 4. The method of forming a photoresist pattern according to claim 3, wherein the photoresist coated with a thick film (200 mu m) is also capable of one exposure to the bottom, and has a line width in the range of 30 to 100 mu m. The composition according to claim 1, which is a photosensitive material for an electrode for PDP and a partition material. The method for forming a transparent electrode pattern according to claim 3, wherein the PDP is for forming an electrode.

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