JPH11120906A - Plasma display electrode, its manufacture, and plasma display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the fineness and reliability of an electrode by setting the line width, pitch, thickness, specific resistance and adhesive strength to a substrate of the electrode to be formed on the substrate to specified values, respectively. SOLUTION: A photosensitive conductive paste containing a conductive powder, glass frit and a photosensitive organic component is applied onto a substrate to form a pattern by photolithography, and the resulting substrate is baked to form an electrode having a line width of 15-60 μm, a pitch of 80-200 μm, a thickness of 1-10 μm, a specific resistance of 2.5-5.0 μmΩ.cm, an adhesive to substrate of 5 N or more. As the glass flit, a glass frit having a thermal softening point (Ts) of 450-550 deg.C, an average grain size of 0.5-1.4 μm and a thermal expansion coefficient at 50-400 deg.C (α)50-400 of 75-90×10<-7> /K is preferably used. The electrode preferably contains at least one metal component selected from the group consisting of Ag, Ni and Pt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display electrode having high definition, low resistance and high adhesive strength, a method for manufacturing the same, and a plasma display using the electrode.

[0002]

2. Description of the Related Art Plasma display panels (PDPs)
Since they can display at a higher speed than a liquid crystal panel and can be easily made larger, they have permeated OA equipment and information display devices. Further, progress in the field of high-definition television is highly expected.

[0003] With the expansion of applications of such PDPs,
Attention has been focused on color PDPs having a large number of fine display cells. A PDP generates a plasma discharge between an anode and a cathode facing each other in a discharge space provided between a front glass substrate and a rear glass substrate, and emits light from a gas sealed in the discharge space. The display is performed. In this case, the anode and cathode electrodes on the glass substrate are arranged in parallel with a plurality of linear electrodes, and the electrodes face each other with a small gap therebetween, and the direction in which the linear electrodes cross each other. It is configured so as to face each other.

Further, among the PDPs, a surface discharge type PDP having a three-electrode structure suitable for color display using a phosphor has a plurality of pairs of display electrodes which are adjacent to each other in parallel and a plurality of pairs which are orthogonal to each pair of electrodes. Address electrodes.

The above-mentioned address electrode is usually formed by printing a silver paste or the like on a glass substrate by using a printing mask having a mask pattern corresponding to the address electrode by a screen printing method, followed by firing. However, in the screen printing method, the width of the electrode pattern cannot be reduced to 100 μm or less even if the mask pattern accuracy, squeeze hardness, printing speed, and dispersibility are optimized. Was. In the screen printing method, the accuracy of the print mask depends on the accuracy of the mask plate making. Therefore, when the print mask is large, the dimensional error of the mask pattern becomes large. Therefore, in the case of a PDP having a large area of 30 inches or more, it is increasingly technically difficult to produce a high-definition PDP.

Further, PDPs are classified into a transmission type and a reflection type. In the case of the reflection type, an address electrode and a partition (rib) of an insulating layer are provided on the light emitting layer side of the back glass, and then a phosphor is formed. I have. After the address electrodes are printed with a silver paste and dried, the insulating glass paste is changed by a print mask for the partition, depending on the height and width. For example, in order to obtain a partition with a height of 200 μm before firing, 1
0 It is necessary to print over and over several times. After that, silver paper
The address electrodes and the partition walls are formed by baking the paste and the insulating paste at once. However, as the size of the PDP becomes larger, the pattern pitch of the silver paste is already at the other end of the glass substrate (depending on the dimensional accuracy of the print mask) when the alignment for the partition is performed with reference to one end of the glass substrate. And the pattern pitch of the print mask for the partition are accumulated, so that a large displacement occurs between the address electrode and the partition. For this reason, a high-definition electrode pattern cannot be obtained, and enlargement of the electrode is also very limited, and it is necessary to solve the problem.

As a method for improving the disadvantages of the screen printing, Japanese Patent Application Laid-Open Nos.
As described in JP-A-296534 and JP-A-63-205255, an insulating paste is baked, a conductive paste is printed and baked to improve the electrode shape, and photolithography is used for forming an anode electrode. Technologies that use technology and those that use a conductive paste by photolithography using a photoresist have been proposed.However, in order to obtain an electrode that simultaneously satisfies low resistance and large size in addition to forming a fine pattern, Was not enough.

Further, Japanese Patent Application Laid-Open No. Sho 63-292504,
JP-A-2-268870, JP-A-3-17169
No. 0 and Japanese Patent Application Laid-Open No. HEI 3-180092 discuss the composition of a conductive paste or use a so-called photosensitive conductive paste in which a photosensitive resin is added as an organic component in the conductive paste to form a fine pattern by photolithography. Although there has been proposed an electrode having an improved size or an optimized particle diameter of the metal powder, it has not been sufficient as an electrode that simultaneously satisfies formation of a fine pattern and low resistance and large size.

In JP-A-3-163727 and JP-A-5-271576, electrodes formed by a photosensitive conductive paste method are proposed as electrodes for a plasma display panel. It was not sufficient as an electrode to increase the adhesive strength with the electrode.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to increase the definition and reliability of the electrodes of a plasma display, and to increase the discharge space in a high definition display by reducing the line width at a narrow pitch. An object of the present invention is to provide a plasma display electrode having an improved aperture ratio and a method of manufacturing the same.

Another object of the present invention is to provide a high-definition, high-definition, high-brightness plasma display using the above-mentioned electrodes, which is compatible with high definition.

[0012]

An object of the present invention is to provide an electrode formed on a substrate and having a line width (L) of one.
5 to 60 μm, pitch (P) 80 to 200 μm, thickness (T) 1 to 10 μm, specific resistance 2.5 to 5.0 μΩ
Cm, the bonding strength to the substrate is 5 N or more, which is achieved by an electrode for a plasma display. The electrode for a plasma display of the present invention has the following preferred embodiments.

The upper surface width (Lt) and the half-value width (L
h) and the lower surface width (Lb) simultaneously satisfy the following expressions (1) and (2).

0.8 ≦ Lt / Lh ≦ 1.0 (1) 1.0 ≦ Lb / Lh ≦ 1.3 (2) At least one selected from the group consisting of Ag, Ni and Pt
Contain certain metal components.

The electrode contains a glass frit;

The glass frit contains 30 to 95% by weight of Bi ₂ O ₃ in terms of oxide.

The glass frit is expressed in terms of oxide, 30 to 85% by weight of Bi ₂ O ₃ 5 to 30% by weight of SiO ₂ 5 to 20% by weight of B ₂ O _{3 3 to} 10% by weight of ZrO ₃ Al ₂ O ₃ 1 component composed of 5% by weight of the composition range containing 80 wt% or more, and Na ₂ O, K ₂ O and Li ₂ O substantially contains no.

The glass transition point (T) of the glass frit
g) is 400 to 500 ° C. and the thermal softening point (Ts) is 450 to
550 ° C, average particle size of 0.5 to 1.4 µm, top size of 4.5 µm or less, and thermal expansion coefficient (α) of ₅₀ to ₄₀₀ ° C of ₅₀ to _{400 of} 75 to 90 × 10 ^-7 / In addition, the method for producing an electrode for a plasma display of the present invention comprises applying a photosensitive conductive paste containing a conductive powder, a glass frit and a photosensitive organic component onto a substrate, and forming a pattern by photolithography. After firing, the line width (L) is 15 to 60 μm and the pitch (P) is 80 to 200.
μm, thickness (T) is 1 to 10 μm, and specific resistance is 2.5 to
An electrode having a bond strength of 5.0 μΩ · cm and a substrate of 5 N or more is formed. In the present invention, the glass frit has a heat softening point (T
s) is from 450 to 550 ° C., and the average particle size is from 0.5 to
1.4 μm and a coefficient of thermal expansion (α) of ₅₀ to 400 ° C. ₅₀ to
It is preferable to use a glass frit of ₄₀₀ to 75 to 90 × 10 ⁻⁷ / K.

Further, the plasma display of the present invention is provided with the above-mentioned electrodes.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The line width (L) of the electrode for a plasma display of the present invention must be in the range of 15 to 60 μm, and preferably 20 to 50 μm. If it is less than 15 μm, the specific resistance increases and the adhesive strength also decreases. On the other hand, when the thickness exceeds 60 μm, when a dielectric layer is formed on the electrode, thermal stress occurs due to unevenness of the electrode and a difference in thermal expansion coefficient, and a dielectric layer crack occurs.

The pitch (P) of the electrodes for the plasma display must be in the range of 80 to 200 μm.
Preferably it is 80 to 150 μm. If it is less than 80 μm, the line width needs to be reduced, and the specific resistance increases and the bonding strength decreases. On the other hand, when the thickness exceeds 200 μm, the purpose of the present invention to provide a high-definition plasma display is not satisfied.

Further, the thickness (T) needs to be 1 to 10 μm, and preferably 1 to 6 μm. If the thickness is less than 1 μm, the conductor film becomes too thin, so that a hole or a pinhole occurs. In addition, the specific resistance increases and the adhesive strength also decreases. If the thickness exceeds 10 μm, when a dielectric layer is formed on the electrode, thermal stress occurs due to unevenness of the electrode and a difference in thermal expansion coefficient, and a crack occurs in the dielectric.

The specific resistance value must be in the range of 2.5 to 5.0 μΩ · cm, preferably 2.5 to 4.0 μΩ.
・ Cm. If the specific resistance is less than 2.5 μΩcm,
It becomes difficult to control the discharge characteristics. On the other hand, if it exceeds 5.0 μΩ · cm, the driving voltage becomes high, which is not preferable. When the specific resistance is within this range, the electrode thickness can be reduced to 10 μm or less. Further, the line width can be reduced, and
A discharge space at a narrow pitch of 0 μm or less can be secured, and a high-definition plasma display panel can be obtained. Further, the adhesive strength needs to be 5N or more,
It is preferably 10 N or more. If it is less than 5N, the electrode will peel off or break. Further, the yield and reliability when the size of the panel is increased are reduced. The higher the bonding strength, the better, but 30 N in consideration of the breaking strength of the electrode itself.
The following is preferred.

Further, in the electrode for a plasma display of the present invention, when Lt is an upper surface width, Lh is a half width, and Lb is a lower surface width, 0.8 ≦ Lt / Lh ≦ 1.0 1.0 ≦ Lb / Lh ≦ It is preferably in the range of 1.3.

This is illustrated in FIG. 1 as an example. (In the figure, Lt: upper surface width, Lh: half width, Lb:
The lower surface width. When Lt / Lh exceeds 1.0, constriction occurs in the center of the electrode or an inverted trapezoidal shape, and the electrode ends protrude (corners occur at the ends) and the specific resistance tends to increase. There is. In addition, a dielectric glass is formed on the electrode, but thermal stress is generated in the dielectric layer due to a difference in thermal expansion coefficient between the electrode and the dielectric layer, so that cracks are easily generated or the panel size becomes 21 inches or more. Then, disconnection of the stripe-shaped electrode may occur. Further, the bonding area of the electrode to the glass substrate is reduced, the bonding strength is reduced, and the electrode is liable to peel off, which is not preferable. 0.8
If it is less than 1, the upper surface becomes too thin and the ratio of the discharge space, that is, the aperture ratio becomes small, which is not preferable in that the luminance is reduced.

On the other hand, if Lb / Lh is less than 1.0, the bonding area of the electrode to the substrate decreases, and the bonding strength decreases.
The electrode may come off or cause disconnection. On the other hand, if it exceeds 1.3, a narrow pitch is not preferable because the discharge space decreases, that is, the aperture ratio decreases, and the brightness of the plasma display decreases. These values are more preferably Lt / Lh = 0.9 to 1.0, Lb / L
h = 1.0 to 1.2.

The cross-sectional shape of the electrode for a plasma display is preferably a rectangular shape because cracks are less likely to occur when a dielectric layer is formed, and the circuit resistance of the electrode can be calculated and designed.

In the shape of each part of the electrode of the present invention, the pitch is P,
When the line width is L and the thickness is T, it is preferable that the following relationship be established, particularly in view of the panel brightness and discharge life.

When P = 80-150 μm, L = 15-40 μm, T = 1-5 μm. When P = 150-200 μm, L = 30-60 μm, T = 1-7 μm. Electrode for plasma display of the present invention. Preferably contains at least one metal component selected from the group consisting of Ag, Ni and Pt.
It is preferable to use a low-resistance conductive powder that can be baked at a temperature of 0 ° C. or lower. For example, Ag (97-99.5) -Pd
(3-1.5), Ag (97-99.5) -Pd (2-
0.5) -Pt (0.5-2), Ag (97-99.
5) A ternary or binary mixed noble metal powder such as -Pt (3-0.5) (where parentheses indicate weight%) is used.

The average particle size of these conductive powders is preferably 0.6 to 4.5 μm, more preferably 0.8 to 4.5 μm.
3.5 μm. When the particle diameter is 0.6 μm or more, light smoothly passes through the printed film during exposure to ultraviolet light,
This is preferable in that a fine pattern can be formed. When the particle diameter is 4.5 μm or less, the surface of the electrode pattern after printing becomes smooth, and the pattern accuracy, thickness and dimensional accuracy of the thin film conductor of 10 μm or less are improved.

The specific surface area of the conductive powder is 0.3 to 2.5.
A range of m ² / g is preferred. More preferably, the specific surface area is 0.35 to 2.0 m ² / g. When it is at least 0.3 m ² / g, it is preferred in that the accuracy of the electrode pattern is excellent. When the surface area is less than 2.5 m ² / g, the surface area of the powder is small,
Since exposure curing is sufficiently performed to the lower portion without scattering of ultraviolet rays, defects such as peeling during development do not occur.

The tap density of the conductive powder is 3 to 6 g.
/ Cm ² . More preferably, 3.5
５5 g / cm ² . When the tap density is in this range, the ultraviolet ray transmittance is good, and the electrode pattern accuracy is improved. Further, a dense film having good leveling property can be obtained in the coating film after printing the paste.

The conductive powder may be in the form of particles (particles), polyhedron, or sphere, but is preferably a monodisperse particle, without agglomeration, and spherical. In this case, the sphericity is preferably 90% by number or more. The sphericity means the ratio of spherical particles when powder is photographed with an optical microscope at a magnification of 300 times and countable particles are counted. If it is spherical, scattering of ultraviolet light during exposure will be very small,
A highly accurate pattern can be obtained, and irradiation energy can be reduced.

In the present invention, it is preferable to include a glass frit in the electrode for the plasma display. This is because the conductive powder is baked on the glass substrate or the sintering aid for sintering the conductive powder has an effect of reducing the conductor resistance.

At this time, the glass transition temperature (Tg) and the thermal softening point (Ts) of the glass frit are 4
The temperature is preferably from 00 to 500 ° C and from 450 to 550 ° C. More preferably, Tg and Ts are each 440
５００500 ° C., 460-530 ° C. When Tg and Ts are respectively 400 ° C. and 450 ° C. or more, the sintering of the glass starts after the photosensitive organic compound such as a polymer or a monomer evaporates, the debinding property of the organic compound is excellent, and the electrode does not peel off. This is preferable because a dense and low-resistance conductive film can be obtained. Tg and Ts are 500 ° C and 55 ° C, respectively.
The temperature of 0 ° C. or less is preferable in that sufficient adhesion strength and a dense film can be obtained between the conductive film and the glass substrate when the film is baked at a temperature of 600 ° C. or less.

Further, the composition of the glass frit is B
It is preferable that the i ₂ O ₃ is contained in a range of 30 to 95 wt%. When the content is 30% by weight or more, when the photosensitive conductive paste is baked on a glass substrate, the glass transition point and the thermal softening point are easily controlled, and the adhesive strength of the conductive film (the fired electrode) to the glass substrate is increased. High effect. Also 95
When the content is more than 10% by weight, the thermal softening point of the glass frit is in a preferable range, and the glass frit does not melt before the binder in the photosensitive conductive paste evaporates. For this reason, the photosensitive conductive paste is excellent in binder removal properties, the sinterability of the conductive film is good, and the adhesive strength to the substrate is high.

Further, the glass frit is expressed in terms of oxide as 30 to 85% by weight of Bi ₂ O ₃ 5 to 30% by weight of SiO ₂ 5 to 20% by weight of B ₂ O ₃ 3 to 10% by weight of ZrO ₂ Al ₂ O ₃ 1 containing 5 wt% of 80% by weight or more components having the composition range and Na ₂ O, K ₂ O, is preferably an alkali-free glass frit that does not substantially contain Li ₂ O. By satisfying the above conditions, a glass frit capable of firmly baking a conductive film on a glass substrate at 550 to 600 ° C. is obtained.

[0038] SiO ₂ is preferably added in amounts of 5 to 30 wt%, if it is 5 wt% or more, the adhesion strength when baked on a glass substrate is high, excellent stability of the glass frit. When the content is 30% by weight or less, the heat-resistant temperature is appropriately maintained, and baking on a glass substrate at 600 ° C. or less can be easily performed.

B ₂ O ₃ is preferably blended in a range of 5 to 20% by weight. B ₂ O ₃ is an electrically insulating conductive paste, adhesive strength, electric and thermal expansion coefficient, the baking temperature so as not to impair the mechanical and thermal properties 550
It is blended in order to suppress the temperature within the range of 600 ° C. 5% by weight
When the content is more than the above, the adhesive strength is excellent, and when the content is 20% by weight or less, it is preferable in terms of stability of the glass frit.

It is preferable that ZrO ₂ is blended in a range of 3 to 10% by weight. ZrO ₂ is preferable because it can improve the acid resistance of the glass frit. That is, depending on the composition of the glass frit, the glass frit reacts with the photosensitive organic component, and the paste tends to cause a gelling reaction. However, when ZrO ₂ is added, the gelation is suppressed. It is preferably at least 3% by weight in view of the effect of suppressing gelation.
The amount of 0% by weight or less is preferable in terms of baking on a glass substrate since the heat resistance temperature of the glass becomes appropriate.

It is preferable that Al ₂ O ₃ is blended in a range of 1 to 5% by weight. When the amount of Al ₂ O ₃ is in this range, the thermal stability, coefficient of thermal expansion, glass transition point, and thermal softening point of the glass frit can be suppressed, which is preferable.

The glass frit may contain Na ₂ O, Li ₂ , which may degrade the discharge characteristics of the plasma, react with an alkali component and silver powder, and cause a problem that the glass substrate turns yellow.
It is preferable that alkali metal oxides such as O and K ₂ O are not substantially contained. 0.5% by weight when contained
It is preferably at most 0.1% by weight, more preferably at most 0.1% by weight.

In the glass frit, B _a O, Ti
By including O ₂ , ZnO, CaO, and ZrO ₂ , the thermal expansion coefficient, glass transition point, and glass softening point can be suppressed, but the amount is preferably less than 10% by weight.

The glass frit content in the electrode is as follows:
(% By weight based on electrode weight after firing)
Preferably it is 5% by weight. More preferably 1.5
~ 3.5% by weight. In order to reduce the resistance and the thickness of the electrodes on the front and back plates of the PDP, it is preferable that the amount of glass frit is small. Glass frit has electrical insulation properties, and as the glass frit increases, the resistance of the electrode tends to increase. With a thin film conductor of 8 μm or less, film peeling occurs due to the difference in the thermal expansion coefficient between the conductive powder and the glass frit. Therefore, the content is preferably 5% by weight or less. Further, the content is preferably 1% by weight or more from the viewpoint that a strong adhesive strength between the electrode film and the glass substrate can be obtained.

The method of manufacturing an electrode for a plasma display of the present invention is preferably manufactured by a photosensitive conductive paste method which has few steps and can form a fine pattern. In the photosensitive conductive paste method, a photomask pattern is baked by exposure using a conductive powder mainly composed of conductive powder, metal / inorganic components composed of glass frit, and photosensitive organic components, and an electrode pattern is formed by development. Then, firing is performed to obtain an electrode.

Specifically, a photosensitive conductive paste containing a conductive powder, a glass frit, and a photosensitive organic component is applied onto a substrate, patterned by photolithography, baked, and then baked to obtain a line width (L). ) Is 15 to 60 μm, pitch (P) is 80 to 200 μm, and thickness (T) is 1 to 10 μm.
m, a method of forming an electrode having a specific resistance of 2.5 to 5.0 μΩ · cm and an adhesive strength to a substrate of 5 N or more is a high-definition display by reducing a line width at a narrow pitch, which is an object of the present invention. It is preferable because the discharge space can be enlarged and the aperture ratio can be improved, and a high-definition, high-definition, high-luminance display compatible with HDTV can be easily manufactured.

In the present invention, the photosensitive organic component constituting the photosensitive conductive paste is an organic component containing a photosensitive compound, and the content of the photosensitive compound is 10% by weight or more of the photosensitive organic component. It is preferable in terms of sensitivity to light. More preferably, it is at least 30% by weight.

The photosensitive compound includes a photo-insoluble type and a photo-solubilized type. Examples of the photo-insolubilized type include (1) those containing a functional monomer, oligomer, or polymer having at least one unsaturated group in the molecule,
(2) those containing photosensitive compounds such as aromatic diazo compounds, aromatic azide compounds, and organic halogen compounds;
(3) There is a so-called diazo resin such as a condensate of a diazo-based amine and formaldehyde.

The photo-soluble type includes (4) a complex of a diazo compound with an inorganic salt or an organic acid, a compound containing quinone diazos, and (5) a quinone diazo compound bonded to an appropriate polymer binder. For example, phenol, naphthoquinone 1,2-diazide of novolak resin
5-sulfonic acid ester and the like.

In the present invention, all of the above can be used, but the above (1) is preferred in terms of ease of handling and quality design.

Specific examples of the photosensitive monomer having a functional group in the molecule include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate, iso-butyl acrylate, tert-
Butyl acrylate, n-pentyl acrylate, allyl acrylate, benzyl acrylate, butoxyethyl acrylate, butoxytriethylene glycol acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, 2-ethylhexyl acrylate, glycerol acrylate, glycidyl acrylate, hepta Decafluorodecyl acrylate, 2-hydroxyethyl acrylate, isobonyl acrylate, 2-hydroxypropyl acrylate, isodexyl acrylate, isooctyl acrylate, lauryl acrylate, 2-methoxyethyl acrylate, methoxyethylene glycol acrylate, methoxydiethylene glycol acrylate, octafluorope Chill acrylate, phenoxyethyl acrylate, stearyl acrylate, trifluoroethyl acrylate, allylated cyclohexyl diacrylate, 1,4-butanediol diacrylate,
1,3-butylene glycol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate,
Polyethylene glycol diacrylate, dipentaerythritol hexaacrylate, dipentaerythritol monohydroxypentaacrylate, ditrimethylolpropane tetraacrylate, glycerol diacrylate, methoxylated cyclohexyl diacrylate, neopentyl glycol diacrylate, propylene glycol diacrylate, polypropylene glycol diacrylate , Triglycerol diacrylate, trimethylolpropane triacrylate, acrylamide,
Aminoethyl acrylate and those obtained by partially or entirely changing acrylate in the molecule of the above compound to methacrylate, γ-methacryloxypropyltrimethoxysilane, 1-vinyl-2-pyrrolidone and the like can be mentioned.

Further, phenyl (meth) acrylate, phenoxyethyl (meth) acrylate, benzyl (meth) acrylate, 1-naphthyl (meth) acrylate, 2-naphthyl (meth) acrylate, bisphenol A di (meth) acrylate, bisphenol A -Di (meth) acrylate of ethylene oxide adduct, di (meth) acrylate of bisphenol A-propylene oxide adduct, 1-naphthyl (meth) acrylate, 2-naphthyl (meth) acrylate, thiophenol (meth) acrylate, benzyl Acrylates such as mercaptan (meth) acrylate, styrene, p
-Methylstyrene, o-methylstyrene, m-methylstyrene, α-methylstyrene, chloromethylstyrene,
Styrenes such as hydroxymethylstyrene, and some or all of the hydrogen atoms in these aromatic rings are chlorine,
Those substituted with bromine atoms, iodine or fluorine,
Further, methacrylate in which part or all of the acrylate in the molecule of the above compound is used can be used. Other examples include γ-methacryloxypropyltrimethoxysilane and 1-vinyl-2-pyrrolidone.

In the present invention, one or more of these can be used. In addition to these, the developability after exposure can be further improved by adding an unsaturated acid such as an unsaturated carboxylic acid.

Specific examples of unsaturated carboxylic acids include:
Examples include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetic acid, and acid anhydrides thereof.

On the other hand, examples of the oligomer or polymer having a functional group in the molecule include a functional group added to a side chain or a molecular terminal of an oligomer or polymer obtained by polymerizing at least one of the above-mentioned monomers. What was made can be used. By containing at least an alkyl acrylate or an alkyl methacrylate, and more preferably containing at least methyl methacrylate, a polymer having good thermal decomposability can be obtained.

Preferred functional groups are those having an ethylenically unsaturated group. Examples of the ethylenically unsaturated group include a vinyl group, an allyl group, an acryl group, and a methacryl group.

A method for adding such a functional group to an oligomer or a polymer is based on a method in which an ethylenically unsaturated compound having a glycidyl group or an isocyanate group or an acrylic acid is added to a mercapto group, an amino group, a hydroxyl group or a carboxyl group in the polymer. There is a method in which chloride, methacrylic chloride or allyl chloride is added to make an addition reaction.

Examples of the ethylenically unsaturated compound having a glycidyl group include glycidyl acrylate, glycidyl methacrylate, allyl glycidyl ether, glycidyl ethyl acrylate, crotonyl glycidyl ether, glycidyl ether crotonic acid and glycidyl ether isocrotonic acid. .

Examples of the ethylenically unsaturated compound having an isocyanate group include (meth) acryloyl isocyanate and (meth) acryloylethyl isocyanate.

The ethylenically unsaturated compound having a glycidyl group or an isocyanate group, acrylic acid chloride, methacrylic acid chloride or allyl chloride is used in an amount of 0.05 to 0.05 with respect to the mercapto group, amino group, hydroxyl group and carboxyl group in the polymer. It is preferable to add one molar equivalent. Further, by copolymerizing an unsaturated acid such as an unsaturated carboxylic acid, the developability after exposure can be improved. Specific examples of the unsaturated carboxylic acid, as described above, acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid,
Vinyl acetic acid and acid anhydrides thereof.

The acid value (AV) of the thus obtained polymer or oligomer having an acidic group such as a carboxyl group in the side chain is 50 to 180, more preferably 70 to 140.
Is preferable. When the acid value is less than 50, the allowable development width becomes narrow. Further, when the acid value exceeds 180, the solubility of the unexposed portion in the developing solution is reduced, so that when the developing solution concentration is high, peeling occurs to the exposed portion, and a high-definition pattern may not be obtained. is there.

Further, as a binder, polyvinyl alcohol, polyvinyl butyral, methacrylate polymer, acrylate polymer, acrylate-methacrylate copolymer, α-methylstyrene polymer, butyl methacrylate resin, etc. Photosensitive polymers may be added.

It is preferable to use the photosensitive monomer in an amount of 0.05 to 10 times the amount of the oligomer or the polymer. More preferably, the amount is 0.1 to 3 times. If the amount exceeds 10 times, the viscosity of the paste becomes small, which is not preferable in terms of dispersibility in the paste. If the amount is less than 0.05 times, the unexposed portion is not preferable in terms of solubility in a developing solution.

In addition, if necessary, a photopolymerization initiator, a sensitizer, a sensitizing aid, a polymerization inhibitor, a plasticizer, a thickener, an organic solvent, an antioxidant, a dispersant Further, an additive component such as an organic or inorganic suspending agent may be contained.

As specific examples of the photopolymerization initiator,
Benzophenone, methyl o-benzoylbenzoate, 4,
4-bis (dimethylamine) benzophenone, 4,4-
Bis (diethylamino) benzophenone, α-amino
Acetophenone, 4,4-dichlorobenzophenone, 4
-Benzoyl-4-methyldiphenyl ketone, dibenzyl ketone, fluorenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenyl-2-phenylacetophenone, 2-hydroxy-2-methylpropiophenone, p -T-butyldichloroacetophenone, thioxanthone, 2-methylthioxanthone, 2-
Chlorothioxanthone, 2-isopropylthioxanthone, diethylthioxanthone, benzyl, benzyldimethylketanol, benzyl-methoxyethylacetate
Benzoin, benzoin methyl ether, benzoin butyl ether, anthraquinone, 2-t-butylanthraquinone, 2-amylanthraquinone, β-chloroanthraquinone, anthrone, benzanthrone, dibenzosuberone, methyleneanthrone, 4-azido Benzalacetophenone, 2,6-bis (p-azidobenzylidene) cyclohexanone, 2,6-bis (p-azidobenzylidene) -4-methylcyclohexanone, 2-phenyl-1,2-butadione-2- (o-methoxy) Carbonyl) oxime, 1-phenyl-propanedione-2-
(O-ethoxycarbonyl) oxime, 1,3-diphenyl-propanetrione-2- (o-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxy-propanetrione-2- (o-benzoyl) oxime, Michler-
Ketone, 2-methyl- [4- (methylthio) phenyl]
-2-morpholino-1-propanone, naphthalenesulfonyl chloride, quinoline sulfonyl chloride, N
-Phenylthioacridone, 4,4-azobisisobutyronitrile, diphenyldisulfide, benzthiazo-
Rudisulfide, triphenylphorphine, camphor
Quinone, carbon tetrabromide, tribromophenylsulfone,
Examples include a combination of a photoreducing dye such as benzoin peroxide, eosin, and methylene blue with a reducing agent such as ascorbic acid and triethanolamine. In the present invention, one or more of these can be used.

Further, the photopolymerization initiator is preferably contained in an amount of 0.1 to 30% by weight, more preferably 2 to 20% by weight, based on the amount of the photosensitive organic component. If the amount of the photopolymerization initiator is too small, the photosensitivity becomes poor, and if the amount of the photopolymerization initiator is too large, the residual ratio of the exposed portion may be too small.

A sensitizer is added to improve the sensitivity. Specific examples of the sensitizer include 2,3-bis (4-diethylaminobenzal) cyclopentanone, 2,6-bis (4-dimethylaminibenzal) cyclohexanone,
26-bis (4-dimethylaminobenzal) -4-methylcyclohexanone, diethylthioxanthone, Michler's ketone, 4,4-bis (diethylamino) -benzophenone, 4,4-bis (dimethylamino) chalcone,
4,4-bis (diethylamino) chalcone, p-dimethylaminocinnamylidene indanone, p-dimethylaminobenzylidene indanone, 2- (p-dimethylaminophenylvinylene) -isonaphthothiazole, 1,3-
Bis (4-dimethylaminobenzal) acetone, 1,3
-Carbonyl-bis (4-diethylaminobenzal) acetone, 3,3-carbonyl-bis (7-diethylaminocoumarin), N-phenyl-N-ethylethanolamine, N-phenylethanolamine, N-tolyldiethanolamine, N-phenylethanolamine, isoamyl dimethylaminobenzoate, isoamyl diethylaminobenzoate, 3-phenyl-5-benzoylthio-tetrazo-lazole, 1-phenyl-5-ethoxycarbonylthio-tetrazole and the like can be mentioned. . In the present invention, one or more of these can be used. Some sensitizers can also be used as photopolymerization initiators.

When the sensitizer is added to the photosensitive conductive paste, the amount added is 0.1 to 10% by weight, more preferably 0.2 to 5% by weight, based on the reactive component (photosensitive component). weight%
It is. If the amount of the sensitizer is too small, the effect of improving the photosensitivity is not exhibited, and if the amount of the sensitizer is too large, the residual ratio of the exposed portion may be too small.

In order to improve the thermal stability during storage in the photosensitive conductive paste, a thermal polymerization inhibitor is preferably added. Specific examples of the thermal polymerization inhibitor include hydroquinone, N-nitrosodiphenylamine, phenothiazine,
pt-butylcatechol, N-phenylnaphthylamine, 2,6-di-tert-butyl-p-methylphenol,
Chloranyl, pyrogallol and the like can be mentioned. When a thermal polymerization inhibitor is added, its amount is usually 0.1 to 5% by weight in the photosensitive conductive paste, more preferably,
0.2 to 3% by weight. If the amount of the thermal polymerization inhibitor is too small, the effect of improving the thermal stability during storage is not exhibited, and if the amount of the thermal polymerization inhibitor is too large, the residual ratio of the exposed portion may be too small. is there.

As the plasticizer, for example, diphthyl phthalate
(DBP), dioctyl phthalate (DOP), polyethylene glycol, glycerin and the like are used.

An antioxidant can be added to the photosensitive conductive paste in order to prevent oxidation of the acrylic copolymer during storage. Specific examples of antioxidants include 2,6-
Di-tert-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-tert-4-ethylphenol,
2,2-methylene-bis- (4-methyl-6-t-butylphenol), 2,2-methylene-bis- (4-ethyl-6-t-butylphenol), 4,4-thibis-
(3-methyl-6-t-butylphenol), 1,1,
3-tris- (2-methyl-6-t-butylpheno-
), 1,1,3-tris- (2-methyl-4-hydroxy-t-butylphenyl) butane, bis [3,3-bis- (4-hydroxy-3-t-butylphenyl) butyric acid Sid] glycol ester, dilauryl thiodipropionate and triphenyl phosphite. When an antioxidant is added, its amount is usually 0.01 to 5% by weight, more preferably 0.1 to 1% by weight, in the photosensitive conductive paste. If the amount of the antioxidant is small, the effect of preventing oxidation of the acrylic copolymer during storage cannot be obtained, and if the amount of the antioxidant is too large, the residual ratio of the exposed portion may be too small.

Further, when it is desired to adjust the viscosity of the solution, an organic solvent may be added to the photosensitive conductive paste. Examples of the organic solvent used at this time include methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol, isopropyl alcohol, tetrahydrofuran, dimethyl sulfoxide, and γ-solvent. Butyrolactone and the like. These organic solvents are used alone or in combination of two or more.

It is preferable that the photosensitive conductive paste contains a glass frit. The glass frit is used for baking conductive powder on a glass substrate and for sintering for sintering the conductive powder. This is because there is an effect of lowering the conductor resistance of the agent.

Glass transition temperature (Tg) of glass frit
And the thermal softening point (Ts) is 400 to 500, respectively.
And 450 to 550 ° C. More preferably, Tg and Ts are 440 to 500 ° C., respectively.
60-530 ° C. Tg and Ts are each 400
If the temperature is higher than 450 ° C, the sintering of the glass starts after the photosensitive organic compounds such as polymers and monomers evaporate,
It is preferable in that it is excellent in the debinding property of the organic compound, does not peel off the electrode, and provides a dense and low-resistance conductor film.
Further, when Tg and Ts are respectively 500 ° C. and 550 ° C. or less, it is preferable that when the film is baked at a temperature of 600 ° C. or less, a sufficient adhesive strength and a dense film can be obtained between the conductor film and the glass substrate.

The glass frit preferably has an average particle diameter of 0.5 to 1.4 μm, a 90% particle diameter of 1 to 2 μm, and a top size of 4.5 μm or less. The average particle diameter and the 90% particle diameter are each 0.5 μm,
If it is less than 1 μm, the particle size of the glass frit becomes small, ultraviolet rays are easily scattered to unexposed portions, and a residual film may remain during development. The average particle diameter, 90% particle diameter, and top size are 1.4 μm, 2 μm, and 4.5 μm, respectively.
If each of them exceeds m, the thermal expansion coefficients of the coarse glass frit and the conductive powder are different from each other. In particular, in the case of a thin film having a thickness of 10 μm or less, the adhesive strength of the conductive film may be reduced and the film may peel off. Also, there is a tendency that the coarse glass frit remains in the conductive film and the adhesive strength is reduced.

When the coefficient of thermal expansion (α) at ₅₀ to ₄₀₀ ° C. of the glass frit is 75 to 90 × 10 ⁻⁷ / K, the conductive film baked on the glass substrate causes the thermal expansion of the substrate and the glass frit. It is preferable in terms of suppressing film peeling due to a difference in expansion coefficient.

The composition of the glass frit is Bi ₂ O ₃
Is preferably blended in the range of 30 to 95% by weight.
When the content is 30% by weight or more, when the photosensitive conductive paste is baked on a glass substrate, it is preferable in controlling the glass transition point and the thermal softening point, and is effective in increasing the adhesive strength of the conductive film to the substrate. . When the content is 95% by weight or less, the softening point of the glass frit becomes appropriate, and the glass frit does not melt before the binder in the photosensitive conductive paste evaporates. For this reason, the paste has good binder removal properties, and has excellent sinterability of the conductor film and excellent adhesive strength to the substrate.

Further, the glass frit is expressed in terms of oxide as 30 to 85% by weight of Bi ₂ O ₃ 5 to 30% by weight of SiO ₂ 5 to 20% by weight of B ₂ O ₃ 3 to 10% by weight of ZrO ₂ Al ₂ O ₃ 1 a made of 5% by weight of the composition range containing 80 wt% or more, and Na ₂ O, it is preferable to K ₂ O and Li ₂ O is a glass frit containing substantially no alkali-free.
When the above conditions are satisfied, a glass frit capable of firmly baking a conductive film on a glass substrate at 550 to 600 ° C. is obtained. In particular, with the glass frit composition described above, it is possible to obtain a preferable glass frit without using PbO or the like that easily causes a gelling reaction of the photosensitive organic component, and it is not possible to increase the paste viscosity or form a pattern due to the gelling reaction. Can be avoided, and a stable photosensitive conductive paste can be obtained.

It is preferable to mix SiO ₂ in the range of 5 to 30% by weight, and when it is 5% by weight or more, it is preferable in view of adhesive strength when baked on a substrate and stability of glass frit. When the content is 30% by weight or less, the heat-resistant temperature is maintained in a preferable range, and the temperature is preferably 600 ° C. or less, since baking on a glass substrate is easy.

It is preferable that B ₂ O ₃ is blended in the range of 5 to 20% by weight. B ₂ O ₃ can reduce the baking temperature to 550 to 60 without impairing the electrical, mechanical and thermal properties of the photosensitive conductive paste, such as electrical insulation, adhesive strength, and thermal expansion coefficient.
It can be controlled in the range of 0 ° C. When the content is 5% by weight or more, the adhesive strength is excellent, and when the content is 20% by weight or less, the stability of the glass frit is excellent.

It is preferable that ZrO ₂ is blended in the range of 3 to 10% by weight. ZrO ₂ is preferable because it can improve the acid resistance of the glass frit. That is, when the glass frit composition of the present invention is used, the glass frit reacts with the photosensitive organic component, and the gelation reaction easily occurs. However, the gelation is suppressed by adding ZrO ₂ . When the content is 3% by weight or more, it is preferable from the viewpoint of the gelation suppressing effect,
When the content is not more than% by weight, the heat-resistant temperature of the glass is maintained in an appropriate range, and baking on a glass substrate becomes easy.

It is preferable to mix Al ₂ O ₃ in the range of 1 to 5% by weight. When the addition of Al ₂ O ₃ is within this range, the thermal stability, coefficient of thermal expansion, glass transition point, and thermal softening point of the glass frit can be controlled, which is preferable. .

The glass frit powder includes Na ₂ O, Li ₂ O, and K ₂ , which may deteriorate the discharge characteristics of the plasma, cause the alkali component to react with the silver powder, and cause the glass substrate to yellow.
Preferably, it does not substantially contain an alkali metal oxide such as O. Even when it is contained, it is at most 0.5% by weight. More preferably, the content is 0.1% by weight or less.

Further, BaO, TiO 2 is contained in the glass frit.
_2. By containing ZnO, CaO, etc., the coefficient of thermal expansion, glass transition point, and glass softening point can be controlled, but the amount is preferably less than 10% by weight.

The content of glass frit in the photosensitive conductive paste is preferably 1.0 to 4.0% by weight. More preferably, it is 1.0 to 2.5% by weight. It is preferable that the amount of the glass frit is small in order to reduce the resistance and the thickness of the electrodes on the front and rear plates of the PDP. Since the glass frit is electrically insulating, if the content exceeds 4% by weight, the resistance of the electrode increases, which is not preferable. Also,
When the glass frit increases, in a conductor having a thin film of 8 μm or less, film peeling easily occurs due to a difference in thermal expansion coefficient between the conductive powder and the glass frit. If it is less than 1% by weight, it is difficult to obtain a strong adhesive strength between the electrode film and the glass substrate.

Also, CaO, BaO,
When a small amount of metals and oxides such as Fe ₂ O ₃ and MgO are contained, the paste reacts with the carboxyl groups of the photosensitive polymer contained in the photosensitive conductive paste to gel in a short period of time, and the paste forms a lump or viscosity. May rise. As a result, printing as a paste cannot be performed, development cannot be performed, and the pattern resolution may be reduced or the pattern may not be formed. This is presumed to be gelation due to the ionic crosslinking reaction of the polymer. In order to prevent such a reaction, it is preferable to add a stabilizer to the extent not adversely affecting the gelation. That is, it is preferable to stabilize the photosensitive conductive paste by subjecting the glass frit to a surface treatment with a compound having an effect such as complexation with a metal or oxide powder that causes a gelling reaction or salt formation with an acid functional group. As such a stabilizer, a triazole compound is preferably used. Among the triazole compounds, benzotriazole and phosphorus compounds act particularly effectively.

The surface treatment of the glass frit with benzotriazole is preferably performed as follows. That is, a predetermined amount of benzotriazole is dissolved in an organic solvent such as methyl acetate, ethyl acetate, ethyl alcohol, and methyl alcohol with respect to the glass frit, and then the glass frit is sufficiently immersed in the solution. 3
Soak for ~ 24 hours. After immersion, preferably 20-30 ° C
And then the solvent is evaporated to perform a triazole treatment, followed by vacuum drying at 50 to 80 ° C. for 5 to 12 hours to produce a powder.

The ratio of the stabilizer used (stabilizer / glass frit) is preferably from 0.2 to 4% by weight, more preferably from 0.4 to 3% by weight. 0.2
When the content is not less than% by weight, the effect of preventing a crosslinking reaction of the polymer is preferable, and gelation can be prevented for a long time. Further, when the content is 4% by weight or less, even when the conductive paste is fired in a non-oxidizing atmosphere, the binder, such as a polymer, a monomer, and a stabilizer, is excellent in debinding, and the characteristics of the conductive film are improved.

When a small amount of water is present in the photosensitive conductive paste, gelation of the photosensitive conductive paste is promoted.
To prevent this, a photosensitive organic component (photosensitive polymer,
It is preferable to completely remove a small amount of water contained in a photosensitive monomer, a photopolymerization initiator, a sensitizer, a photopolymerization accelerator, a plasticizer, a thickener, an organic solvent, an organic dispersant). The removal of water depends on the type of solid or liquid, but is removed by vacuum drying, molecular sieve, rotary evaporator, or the like. Further, with respect to the glass frit, it is preferable to use the glass frit after drying at 150 to 400 ° C. for 5 to 15 hours to sufficiently remove moisture, since gelation can be prevented.

Preferred compositions of the photosensitive conductive paste include the following.

(A) conductive powder: (a) conductive powder,
(B) 84 to 92% by weight, more preferably 86 to 91% by weight, based on the sum of the photosensitive polymer and the photosensitive monomer and (c) the glass frit, (b) the photosensitive polymer and the photosensitive monomer: (a) Conductive powder, 14 to 8% by weight, more preferably 12 to 9% by weight, based on the sum of (b) photosensitive polymer and photosensitive monomer and (c) glass frit, (c) glass frit: (a) conductive 1 to 4% by weight, more preferably 1 to 3% by weight, based on the sum of (b) the photosensitive polymer and the photosensitive monomer and (c) the glass frit, (d) a photopolymerization initiator: (b) When the composition of the photosensitive conductive paste is within the above range, the ultraviolet light is well transmitted at the time of exposure, the photocuring function is sufficiently exhibited, and the development is performed. In time The film strength in the exposed area increases,
An electrode pattern having a fine resolution can be formed. Further, the conductor film after firing is preferable since it has low resistance and high adhesive strength. If necessary, a sensitizer, a photopolymerization accelerator, a plasticizer, a dispersant, a stabilizer, a thixotropic agent, and an organic or inorganic suspending agent are added to the composition, and a slurry of the mixture is formed. It is preferred to make a paste.

At this time, the slurry prepared so as to have a predetermined composition is homogeneously mixed by a stirrer such as a homogenizer, and then uniformly dispersed by a three-roller or kneader to form a photosensitive conductive paste. Can be.

The viscosity of the photosensitive conductive paste is determined by the composition and type of conductive powder, organic solvent, glass frit, plasticizer,
It is appropriately adjusted depending on the addition ratio of a thixotropic agent, a suspending agent, an organic leveling agent, and the like, and its range is 10,000 to 150,000 cps (centipoise). For example, 50,000 to 100,000 cps is preferable in order to obtain a film thickness of 6 to 20 μm by coating the glass substrate with a screen printing method or a bar coater, a roll coater, or an applicator once or twice by a screen printing method.

Next, a preferred method of manufacturing the electrode for a plasma display of the present invention will be described in more detail.

On a glass substrate or a substrate such as a resin film of polyester or the like, a photosensitive conductive paste is applied entirely or partially. As a coating method, a method such as screen printing or a roll coater can be used. The coating thickness can be arbitrarily controlled by adjusting the screen material (polyester or stainless steel), screen mesh number, printing conditions (squeegee angle and speed, clearance, frame size), and paste viscosity. Although it is possible, 6 to 20 μm is preferable. A more preferable range of the thickness is 6 to 15 μm. When the thickness is 6 μm or more, it is easy to obtain a uniform thickness by a printing method,
When it is 20 μm or less, the electrode pattern accuracy is excellent, the cross-sectional shape is rectangular, and the minimum line width / pitch is 15 μm / 80 μm.
This is preferable in that a high-definition pattern of m can be easily obtained and the edge cut is also good.

When the photosensitive conductive paste is applied on a glass substrate, a surface treatment of the substrate can be performed in order to enhance the adhesion between the substrate and the coating film. Examples of the surface treatment liquid include silane coupling agents such as vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, tris- (2-methoxyethoxy) vinylsilane, γ-glycidoxypropyltrimethoxysilane,
γ- (methacryloxypropyl) trimethoxysilane,
[gamma] (2-aminoethyl) aminopropyltrimethoxysilane, [gamma] -chloropropyltrimethoxysilane, [gamma] -mercaptopropyltrimethoxysilane, [gamma] -aminopropyltriethoxysilane and the like, or an organic metal such as organic titanium, organic aluminum and organic zirconium And the like. A silane coupling agent or an organic metal diluted with an organic solvent such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl alcohol, ethyl alcohol, propyl alcohol, or butyl alcohol to a concentration of 0.1 to 5% is used. Can be

Next, this surface treatment liquid is uniformly applied to a substrate by a spinner or the like,
Surface treatment can be performed by drying for minutes.

Next, such a photosensitive conductive paste is applied on a substrate to form a coating film, exposed through a photomask, developed and dried to form a pattern, which is a so-called photolithography method. . That is, the coated film is heated at 70 to 90 ° C. for 20 to 60 minutes, dried and evaporated, and then exposed to ultraviolet light using a film having an electrode pattern or a photomask such as a chrome mask. Then, the photosensitive conductive paste is light-cured. As the photomask to be used, either a negative type or a positive type is selected depending on the type of the photosensitive organic component. Further, in the present invention, a method of directly drawing with red or blue laser light or the like without using a photomask may be used.

As the exposure device, a stepper exposure device, a proximity exposure device, or the like can be used. Also,
When performing large-area exposure, apply a photosensitive conductive paste on a substrate such as a glass substrate, and then perform exposure while transporting, using an exposure machine with a small exposure area,
Exposure of a large area can be performed.

The active light source used at this time is, for example,
Visible light, near-ultraviolet light, ultraviolet light, electron beam, X-ray, etc. are preferable, and among them, ultraviolet light is preferable. As the light source, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, a halogen lamp, a germicidal lamp and the like can be used. Of these, an ultra-high pressure mercury lamp is preferable. The exposure conditions at this time vary depending on the thickness of the conductive film, but are ^{2 to 5} at an output of 5 to 100 mW / cm ² .
Exposure is preferably performed for 0 seconds to 30 minutes.

Next, a so-called negative electrode pattern is formed by removing the uncured portion by the exposure using a developing solution. Development can be performed by an immersion method, a shower method, or a spray method. As the developer used, an organic solvent in which the mixture of the photosensitive organic components can be dissolved can be used. In addition, water may be added to the organic solvent as long as the dissolving power is not lost. When a reactive component having a carboxyl group is present, development can be performed with an aqueous alkali solution. Sodium hydroxide as an aqueous alkaline solution,
Although an aqueous solution of an alkali metal such as an aqueous solution of sodium carbonate or sodium hydrogen carbonate or barium hydroxide can be used, it is preferable to use an aqueous solution of an organic alkali because the alkaline component can be easily removed during firing.

Specific examples of the organic alkali include tetramethylammonium hydroxide, trimethylbenzylammonium hydroxide, monoethanolamine,
And diethanolamine. The concentration of the aqueous alkali solution is usually 0.05 to 2% by weight, more preferably 0.1 to 2% by weight.
1 to 0.5% by weight. If the alkali concentration is too low, unexposed portions are not removed, and if the alkali concentration is too high, the exposed portions may be corroded, which is not good.

Next, the coating film after exposure and development is fired in air. Reactive components such as photosensitive polymers and photosensitive monomers, which are photosensitive organic components, and organic substances such as binders, photopolymerization initiators, sensitizers, sensitizing aids, plasticizers, thickeners, organic solvents and dispersants. Is completely oxidized and evaporated. It is preferable to bake at 560 to 610 ° C. for 15 minutes to 1 hour as a temperature condition and bake on a glass substrate. 560
When the temperature is higher than or equal to ° C., the firing is sufficiently performed, the denseness of the conductive film is excellent, the specific resistance is low, and the adhesive strength with the substrate is improved. The temperature of 610 ° C. or less is preferable in that the glass substrate is not likely to be thermally deformed and the flatness of the pattern is maintained.

The preparation, printing, exposure and development steps of the photosensitive conductive paste need to be performed in a place where ultraviolet rays can be blocked. If not blocked, the paste or coating film will be photo-cured by ultraviolet rays, and a good conductor film (electrode) capable of exhibiting the effects of the present invention cannot be obtained.

Hereinafter, the present invention will be described specifically with reference to examples. In the examples, all concentrations mean% by weight unless otherwise specified.

[0106]

【Example】

(Examples 1 to 13) Conductive powder, B. Photosensitive polymer, C.I. Photosensitive monomer, D.I. Glass frit was prepared, and a photosensitive conductive paste was prepared at the ratio shown in Table 1.

A. Conductive powder (1) Ag powder; monodisperse granular, average particle size 3.2 μm, specific surface area 0.48 m ² / g (2) Ag powder; spherical, sphericity 95% by number, average particle size 2.2 μm, ratio Surface area 1.26 m ² / g (3) 95% Ag-5% Pd powder; monodisperse granular, average particle diameter 3.3 μm, specific surface area 0.82 m ² / g The particle size distribution is measured by a laser type particle size distribution analyzer (MICROT).
RAC).

B. Photosensitive polymer (hereinafter abbreviated as polymer) An acrylic copolymer having a carboxyl group and an ethylenically unsaturated group in a side chain, methacrylic acid (MAA) 40%,
Methyl methacrylate (MMA) 30% styrene (S
t) 30% copolymer carboxyl group (MAA)
To which 0.4 equivalent (equivalent to 40%) of glycidyl methacrylate (GMA) was added and reacted with C.I. D. Photosensitive monomer (hereinafter abbreviated as monomer) Trimethylolpropane triacrylate Glass frit Glass frit I: component (% by weight) bismuth oxide (4
8.1) Silicon dioxide (27.5), boron oxide (1
4.2), zinc oxide (2.6), aluminum oxide (2.8), zirconium oxide (4.8) Average particle diameter: 0.9 μm, 90% particle diameter: 1.8 μm
Top size: 3.8 μm, coefficient of thermal expansion: α ₅₀ to ₄₀₀ =
83 × 10 ⁻⁷ / ° K, glass transition point (Tg); 46
5 ° C., softening point (Ts); 510 ° C. Glass frit II: component (% by weight) bismuth oxide (6
8.5), silicon dioxide (8.8), boron oxide (1
0.8), zinc oxide (2.6), aluminum oxide (2.8), zirconium oxide (6.5) Average particle size: 0.8 μm, 90% particle size: 1.6 μm
Top size: 3.8 μm, coefficient of thermal expansion: α ₅₀ to ₄₀₀ =
75 × 10 ⁻⁷ / ° K, glass transition point; 450 ° C., softening point (Ts); 490 ° C. Glass frit III: (description) Ingredient (% by weight) bismuth oxide (66.9), silicon dioxide (11) 3.0), boron oxide (11.0), zinc oxide (3.5), aluminum oxide (2.8), zirconium oxide (4.8) Average particle diameter: 2.5 μm, 90% particle diameter; 7 μm,
Top size: 11 μm, coefficient of thermal expansion: α ₅₀ to ₄₀₀ = 7
8 × 10 ⁻⁷ / ° K., glass transition point: 491 ° C., softening point (Ts): 528 ° C. The other components used are as follows.

F. Solvent γ-butyrolactone was added in the same amount as the polymer.

G. Photopolymerization initiator 2-methyl-1 [4- (methylthio) phenyl] -2-
Morpholino-1-propanone was added in an amount of 20% by weight based on the total amount of the polymer and the monomer.

H. Sensitizer Diethylthioxanthone was added in an amount of 10% by weight based on the total amount of the polymer and the monomer.

H. Plasticizer Dibutyl phthalate (DBP) is 10% by weight of the polymer
Was added.

I. Thickener 15% by weight based on 2- (2-butoxyethoxy) ethyl acetate
Aerosil (SiO ₂ ) dispersed at a concentration of 4% by weight was added to the total of the conductive powder and the glass frit.

The manufacture of the photosensitive conductive paste and the formation of the electrodes were performed as follows.

A. Preparation of Organic Vehicle A solvent and a binder polymer (photosensitive polymer) were mixed, heated to 80 ° C. with stirring, and homogeneously dissolved. The solution was then cooled to room temperature.

B. Preparation of Paste A conductive powder, a glass frit, a monomer, a photopolymerization initiator, a sensitizer, a plasticizer, and a thickener were mixed with the organic vehicle in the composition described in Table 1 and described above. Next, after preliminarily kneading with a mixer, kneading was performed with three rollers to produce a paste. Thereafter, the paste was filtered through a 400 mesh filter.

C. Printing The above paste is solid-printed to a size of 400 mm square on a glass substrate (430 mm square, 3 mm thick) using a 325 mesh screen of stainless steel wire, and
Dry at 40 ° C. for 40 minutes. The thickness of the dried coating film varies depending on the types and amounts of the conductive powder, polymer and monomer, but is 9 to 13 μm.

F. Exposure and development The above-prepared coating film was applied from the upper surface to 15 mW / cm ² using a chromium mask on which a plasma display panel electrode having a fine pattern of 40 to 70 μm was formed.
Exposure for 30 seconds with an ultra-high pressure mercury lamp with an output of. Then 25
The film was developed by immersion in a 0.5% by weight aqueous solution of monoethanolamine kept at 0 ° C., followed by spraying pure water to wash the non-exposed area.

G. Firing The pattern formed on the glass substrate is heated at 580 ° C in air.
For 15 minutes to produce an electrode film.

Next, the following evaluation was performed on the electrode films obtained in the respective examples.

That is, the film thickness, the resolution, the degree of edge curl at the end of the electrode line, the specific resistance, and the adhesive strength of the fired electrode film were measured and evaluated. Table 1 shows the results.

The film thickness was determined by observing the cross section with a scanning electron microscope (SEM). Regarding the resolution, the conductor film was observed with a microscope, and the line interval at which a line of 40 μm did not overlap with a straight line and reproducibility was obtained was evaluated. For the edge curl, the difference between the thickest part and the thinnest part of the electrode film surface was evaluated by microscopic observation of the roughness and the cross section of the end of the electrode pattern using a surface roughness meter. The adhesive strength was evaluated by soldering a copper wire having a length of 5 cm to an electrode film formed into a 2 × 2 mm square and performing a 90 ° peel test. The specific resistance was obtained by measuring the sheet resistance and calculating from the film thickness.

As is clear from Table 1, all of the above characteristics were satisfactory.

(Comparative Examples 1 and 2) The conductive powder was the Ag powder of (1), and the glass transition point was 491 ° C. and the thermal softening point was 528.
° C, average particle size 2.5 μm, 90% particle size 4.
7μm, 11μm top size glass frit III
, A photosensitive conductive paste was prepared and an electrode film was formed in the same manner as in the example, except that the thickness of the electrode film was changed as shown in Table 1 and the electrode film was evaluated.

The obtained results are shown in Table 1. As a result, the pattern resolution was poor and edge curling occurred remarkably. Also,
The bonding strength was low.

[0126]

[Table 1] Conductive powder (1): Monodispersed granular Ag powder (average particle size 3.2
μm) Conductive powder (2): spherical Ag powder (average particle size: 2.2 μm) Conductive powder (3): monodispersed granular 95% Ag-5% Pd powder (average particle size: 3.3 μm) Glass frit I: average Particle size 0.9 μm, Ts510 ° C glass frit II: average particle size 0.8 μm, Ts490 ° C glass frit III: average particle size 2.5 μm, Ts528 ° C

[0127]

The electrode for a plasma display of the present invention is an electrode formed on a substrate, and has a line width (L) of one.
5 to 60 μm, pitch (P) 80 to 200 μm, thickness (T) 1 to 10 μm, specific resistance 2.5 to 5.0 μΩ
Cm, because the adhesive strength to the substrate is 5N or more,
It has lower resistance and higher adhesive strength than conventional electrodes. Therefore, thinning and reduction of the line width can be performed, and high definition and high reliability of the plasma display electrode can be achieved. Also, by reducing the line width at a narrow pitch, it becomes possible to enlarge the discharge space and improve the aperture ratio in a high-definition plasma display, and to obtain a high-definition, high-definition, high-brightness plasma display compatible with HDTV. Further, since the thickness of the electrode can be reduced, the cost of the plasma display can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram for explaining a cross-sectional shape of an electrode of the present invention.

[Explanation of symbols]

 Lt: Upper surface width Lh: Half width Lb: Lower surface width

Claims (10)

[Claims] An electrode formed on a substrate, having a line width (L) of 15 to 60 μm and a pitch (P) of 80 to 200.
μm, thickness (T) is 1 to 10 μm, and specific resistance is 2.5 to
An electrode for a plasma display, which has an adhesive strength to a substrate of 5.0 μΩ · cm and 5N or more. 2. An upper surface width (Lt) and a half width (L) of the electrode.
2. The electrode for a plasma display according to claim 1, wherein the relationship between h) and the lower surface width (Lb) satisfies the following expressions (1) and (2) simultaneously. 0.8 ≦ Lt / Lh ≦ 1.0 (1) 1.0 ≦ Lb / Lh ≦ 1.3 (2) 3. The electrode for a plasma display according to claim 1, wherein the electrode contains at least one metal component selected from the group consisting of Ag, Ni and Pt. 4. The electrode for a plasma display according to claim 1, further comprising a glass frit. 5. The electrode according to claim 4, wherein the glass frit contains 30 to 95% by weight of Bi ₂ O ₃ in terms of oxide. 6. The glass frit is expressed in terms of oxide as Bi ₂ O ₃ 30 to 85% by weight SiO ₂ 5 to 30% by weight B ₂ O ₃ 5 to 20% by weight ZrO ₃ 3 to 10% by weight Al ₂ O ₃ 1 containing 5 wt% of 80% by weight or more components having the composition range and Na ₂ O, according to claim 4 or 5, wherein it does not substantially contain K ₂ O and Li ₂ O Electrode for plasma display. 7. The glass transition point (T) of the glass frit.
g) is 400 to 500 ° C. and the thermal softening point (Ts) is 450 to
550 ° C., average particle size of 0.5 to 1.4 μm, top size of 4.5 μm or less, and thermal expansion coefficient (α) ₅₀ to _{400 of 50} to ₄₀₀ ° C. of 75 to 90 × 10 ⁻⁷ / K. The electrode for a plasma display according to any one of claims 4 to 6, wherein 8. A photosensitive conductive paste containing a conductive powder, a glass frit and a photosensitive organic component is applied on a substrate, patterned by photolithography, and fired. Item 2. A method for producing an electrode for a plasma display according to Item 1. 9. The glass frit has a heat softening point (T
s) is from 450 to 550 ° C., and the average particle size is from 0.5 to
1.4 μm and a coefficient of thermal expansion (α) of ₅₀ to 400 ° C. ₅₀ to
9. The method for manufacturing an electrode for a plasma display according to claim 8, wherein a glass frit of ₄₀₀ to 75 * 90 < ^-7 > / K is used. 10. A plasma display comprising the electrode according to claim 1.