JPH11167872A - Substrate for plasma display and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a barrier rib with high aspect ratio, high fineness, no defect such as coloring or peeling off by limiting the carbon of the barrier rib to the specified weight percent or less in a substrate on which the barrier rib is formed. SOLUTION: The carbon content of a barrier rib formed in a substrate for a plasma display is limited to 0.1 wt.% or less, preferably to 0.03 wt.% or less. If the carbon content of the barrier rib exceeds 0.1 wt.%, the barrier rib is colored in brown, and in the panel discharge, when ultraviolet rays strike against a phosphor, are excited, and emit light, the light is absorbed in the barrier rib, and luminance and contrast are reduced. When the carbon content in the barrier plate exceeds 0.1 wt.% by unsuitable selection of photosensitive paste for forming the barrier rib, vaporization of an organic component in the baking of the barrier rib does not occur smoothly, and that may cause the stripping off of the barrier rib from the substrate or a dielectric layer, and the generation of bending or meandering of the barrier rib. Preferably, the height of the barrier rib is made 60-160 μm and the width is made 20-200 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate for a plasma display panel or a plasma addressed liquid crystal display.

[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 public information display devices. Further, progress in the field of high-definition television is highly expected. With the expansion of such applications, attention has been paid to color PDPs having fine and numerous 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 is generated from a gas sealed in the discharge space. UV light
The display is performed by hitting the phosphor in the discharge space. In this case, partition walls (also referred to as barriers or ribs) are provided to suppress the spread of the discharge to a certain area, to perform display in a specified cell, and to secure a uniform discharge space.

[0004] These partition walls are usually formed by printing an insulating paste made of glass on a rear glass substrate by screen printing.
After drying, this printing / drying step is repeated 10 to 15 times to a predetermined height, and then fired to form. However, in the ordinary screen printing method, especially when the panel size is increased, it is difficult to align the discharge electrode formed in advance on the front substrate with the printing place of the insulating glass paste, and it is difficult to obtain positional accuracy. There's a problem. In addition, since the glass paste is superimposed and printed 10 to 15 times, the ribs and the side edges of the partition wall and the skirt are disturbed, and the height accuracy cannot be obtained, so that the display quality is deteriorated. There are also problems such as poor workability and low yield. In particular, when a high-definition partition pattern having a small line width and a small pitch is formed, there is a problem that the bottom of the partition is easily spread due to the thixotropy of the paste, and it is difficult to form a sharp and residue-free partition.

[0005] With the increase in the area and resolution of PDPs, the screen printing method makes it difficult to manufacture partition walls having a high aspect ratio and a high definition, and it is disadvantageous in terms of cost. Is coming.

As methods for improving these problems, Japanese Patent Application Laid-Open Nos. 1-2296534, 2-165538, 5-342929, and 6-29 have been proposed.
No. 5676 proposes a method of forming a partition by a photolithography technique using a photosensitive paste. However, in these methods, there are problems that a dense partition wall cannot be obtained after firing and that the sensitivity and resolution of the photosensitive paste are low because the glass content of the photosensitive insulating paste is small. Therefore, in order to obtain a partition wall having a high aspect ratio, it is necessary to repeatedly perform the steps of screen printing, exposure, and development. However, printing
Repetition of exposure and development still has a problem of alignment and a problem of cost, which is a limitation.

[0007] Therefore, in Japanese Patent Application Laid-Open No. 8-50811,
A method has been proposed in which a partition is formed by a single exposure using a photosensitive glass paste method in which glass fine particles and a photosensitive organic component are essential. However, in this method, when producing a high-definition partition having a pitch of 200 μm or less and a line width of the partition of 50 μm or less, the line width may be increased depending on the ratio of the glass fine particles and the photosensitive organic component in the photosensitive paste. However, there is a problem that the line width of the above-mentioned is not obtained, or development residue occurs, so-called residual film occurs, and pattern formability is poor. Further, it is difficult for the organic components to disappear during baking, so-called binder removal property is poor, peeling and coloring may be caused, shrinkage during baking may be increased, and the height during pattern formation may be increased in order to obtain partition walls having a desired height. Therefore, there is a problem that a margin for pattern formation is small and a yield is deteriorated.

[0008]

Further, even if the photosensitive paste is a component combination exhibiting excellent characteristics in the pattern forming step, a problem may occur in the next baking step. That is, the organic component that is cured by photoreaction with the glass fine particles forming the pattern undergoes the action of melting or thermal decomposition in the firing step, but depends on the ratio of the glass fine particles and the photosensitive organic component in the photosensitive paste. The problem is that the baked pattern is colored brown or black or the pattern is peeled off from the substrate due to the phenomenon that the organic component is trapped in the glass melt and carbonized, etc. No pattern was obtained.

Accordingly, an object of the present invention is to improve the above-mentioned problems of the prior art, and to provide a plasma display substrate having a partition having a high aspect ratio and a high definition and having no defects such as coloring and peeling. It is assumed that.

[0010]

The object of the present invention is to provide a substrate having a partition formed thereon, wherein the partition has a carbon content of 0.1% by weight or less. Achieved by the substrate.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, when the carbon content of the partition exceeds 0.1% by weight, the partition exhibits a brown color. When the browning occurs, when the panel discharges, when ultraviolet rays are excited by the phosphor to emit light, the light is absorbed by the partition walls and the brightness and contrast are reduced. Further, the selection of a photosensitive paste described below for forming the partition walls is inappropriate, and the carbon content of the partition walls is less than 0.1.
When the result exceeds 1% by weight, evaporation of organic components does not occur smoothly during baking of the partition walls, so-called poor binder removal property, and the partition walls are peeled off from the substrate or the dielectric layer.
This may cause the partition wall to bend and meander. Further, the change with time of the discharge voltage becomes large, which causes a decrease in luminance and a decrease in discharge characteristics. In the present invention, the carbon content is preferably 0.03% by weight or less.

The carbon content is determined according to JIS Z 2615-
This is based on 1979 (general rules for the method of determining carbon in metallic materials), and is measured using a tubular electric resistance furnace heating-infrared absorption method. In the infrared absorption method, a sample is heated in an oxygen stream, carbon is sufficiently converted to carbon dioxide, moisture in the combustion gas is removed, and then guided to an infrared absorption cell, and the amount of infrared absorption by the carbon dioxide is integrated or circulated. And applied in principle to a sample containing 0.001% by weight or more of carbon. The measuring device is HORIBA EMIA-
810 type. For the calibration, JSS155-12
(Steel), the standard value is 0.041%,
It has been confirmed that 411% is detected. The measurement sample is
Using 100 mg of partition wall powder, the measurement was carried out at a repetition number of 2.
The unit of the measured value is% by weight.

Further, in the present invention, the height of the partition wall is 60 to 1
It is preferable that the partition width is 60 μm, the line width of the partition wall is 20 to 100 μm, and the partition pitch is 80 to 460 μm, since the partition wall becomes a high aspect ratio and high definition plasma display.

As a method for forming a partition on a substrate, the following method is exemplified. That is, a photosensitive paste containing a glass material and a photosensitive organic component as essential components is applied onto a substrate, exposed by photolithography to form a partition pattern, and then fired.

At this time, a glass substrate is preferably used as the substrate.

Further, regarding the photosensitive paste, the present inventors have proposed that the refractive index between the glass material and the photosensitive organic component should be approximated in order to form a high-definition pattern with a high aspect ratio. It has been clarified that it is effective to regulate the average particle diameter of the fine particles, and to add an ultraviolet absorber to suppress the scattering of light and unnecessary light reactions by the glass fine particles.

Therefore, in the present invention, the difference between the average refractive index of the glass material and the average refractive index of the photosensitive organic component is 0.1%.
The following is preferred. Light scattering can be suppressed by setting the difference in the average refractive index between the glass material and the photosensitive organic component to 0.1 or less. If the difference between the average refractive index of the glass material and the average refractive index of the photosensitive organic component exceeds 0.1, light scattering occurs inside the paste, which is not preferable in that high-precision pattern processing is performed. In the present invention, the photosensitive organic component is
It is a material remaining after coating and drying the paste except for the glass material, and means a material containing a photopolymerization initiator, a sensitizer, and other additives.

A glass material generally used as an insulator has a refractive index of about 1.5 to 1.9, whereas a general organic component has a refractive index of 1.45 to 1. 7
In order to match the refractive index, the average refractive index of the glass material is preferably set to 1.5 to 1.8 in the present invention. More preferably, it is 1.5 to 1.65.
The small variation in the refractive index of each glass particle is also important for reducing light scattering, and it is necessary to make the component composition uniform.

The average refractive index of the glass material is 1.5 to 1.8.
This makes it easier to match the refractive index with the photosensitive organic component, which leads to an improvement in the light transmittance of the photosensitive paste (suppression of scattering and reflection), and the irradiated light travels straight to the bottom of the coating film. Since the rate of transmission of the pattern increases, it is possible to form a pattern with high precision.

The measurement of the refractive index of the glass material in the present invention is performed by the Becke method. In particular, 350-
It is preferable to measure with light having a wavelength in the range of 550 nm. Furthermore, i-line (365 nm) or g-line (43
6 nm) is preferred.

In the firing step, it is considered that the thermal decomposition of the three-dimensionally cured organic component formed as a result of the photocuring reaction and the melting of the glass fine particles proceed in parallel. This causes defects such as deformation and coloring of the pattern and peeling from the substrate. For this reason, the glass transition point and softening point, which are the thermal characteristics of the glass fine particle component, are important.

Since the baking on the glass substrate is preferably performed at a low temperature, it is desirable that the glass material has a low melting point in this respect. However, if the balance with the thermal decomposability of the photosensitive organic component to be combined is poor, The above defects occur.

The above problem was evaluated by the debinding property of the paste, and the thermal properties of the glass material combined with the photosensitive organic component were examined. As a result, the glass transition point was 450 to 550 ° C. and the softening point was 500 to 600 ° C. in the present invention. The thermal expansion coefficient is preferably 75 to 90 × 10 ⁻⁷ / K, the glass transition point is 480 to 510 ° C., and the softening point is 510 to 54.
0 ° C. is more preferred. By appropriately selecting and combining a glass material having such thermal characteristics and a photosensitive organic component, and / or appropriately selecting a photosensitive monomer, a photosensitive oligomer, and a photosensitive polymer described below, which constitute the photosensitive organic component. By combining them, it is easy to make the carbon content of the partition walls 0.1% by weight or less, and coloring (browning) and peeling from the substrate do not occur during firing.

By limiting the thermal characteristics of the glass fine particles to the above-mentioned range, a photosensitive monomer component which is liable to cause troubles such as carbonization in the baking step can be used as the photosensitive component. Among such photosensitive monomers,
Since there is a component effective to keep the sensitivity and resolution of the photosensitive paste high, it is very effective to expand the use range of the photosensitive paste in manufacturing the partition.

In particular, when the coefficient of thermal expansion is in the above range,
Maintains compatibility with the coefficient of thermal expansion (80 to 90 × 10 ⁻⁷ / K) of the high strain point glass mainly used for the glass substrate. Various problems caused by warpage due to inconsistency of the thermal expansion coefficient between the glass substrate and the partition due to history can be effectively avoided, and a display with excellent characteristics can be provided.

In addition to such thermal characteristics, the glass material has a particle size of 10% by weight of 1 μm or less, a particle size of 90% by weight of 9 μm or less, an average particle size of 2 to 3.5 μm, and a top size of 30 μm or less. Glass fine particles having a particle size distribution are preferable from the viewpoint of preventing generation of defects in the firing step.

It is presumed that the use of the above glass fine particles improves the dispersibility, makes it difficult to coagulate, eliminates bubbles, and improves the filling ratio of the glass material to the organic components in the paste. As a result, it leads to the improvement of the total light transmittance and the straight transmittance of the paste (suppression of scattering and reflection), and the ratio of the light irradiated at the time of exposure to be transmitted straight to the lowermost part of the coating film increases, and the photo-curing is improved. Since it is sufficiently performed, it is possible to form a partition pattern with high accuracy.

The particle size is measured by laser diffraction.
It is preferable to use a scattering method because it can be easily measured. For example, the measurement conditions when using a particle size distribution analyzer HRA9320-X100 (manufactured by Microtrack) are as follows.

Sample amount: 1 g Dispersion conditions: Ultrasonic dispersion in purified water for 1 to 1.5 minutes. If dispersion is difficult, perform in a 0.2% sodium hexametaphosphate aqueous solution.

Particle refractive index: changed depending on glass type (lithium-based 1.6, bismuth-based 1.88) Solvent refractive index: 1.33 Number of measurements: 2 The composition of the glass material preferably used in the present invention is as follows. What is shown is mentioned.

Lithium oxide: 3 to 10% by weight Silicon oxide: 10 to 30% by weight Boron oxide: 20 to 40% by weight Barium oxide: 2 to 15% by weight Aluminum oxide: 10 to 25% by weight In the above composition, lithium oxide May be used instead of sodium oxide or potassium oxide, but lithium oxide is preferred from the viewpoint of paste stability. The content of these alkali metal oxides not only facilitates the control of the thermal softening temperature and the coefficient of thermal expansion, but also lowers the average refractive index of the glass material. Can be easily reduced. When potassium oxide is used, there is an advantage that the refractive index can be controlled even with a relatively small amount of addition, so that addition of lithium oxide and potassium oxide is effective. In this case, the glass material preferably contains a total of 3 to 10% by weight of an alkali metal oxide.

Silicon oxide (SiO ₂ ) is 10 to 30% by weight
If the amount is less than 10% by weight, the denseness, strength and stability of the partition walls decrease, and the coefficient of thermal expansion deviates from desired values, so that a mismatch with the glass substrate is likely to occur. On the other hand, if it exceeds 30% by weight, the softening point becomes high, which is not preferable in terms of baking on a glass substrate.

Boron oxide (B ₂ O ₃ ) is 20 to 40% by weight
It is preferable to mix in the range of. Boron oxide melts glass materials at temperatures around 800-1200 ° C,
Even when the baking temperature of the glass paste is large, the baking temperature is set to 540 to 610 ° C. so as not to impair the electrical, mechanical and thermal properties such as electrical insulation, strength, coefficient of thermal expansion, and denseness of the partition walls even when silicon oxide is large. It is blended to control in the range of. If the amount is less than 20% by weight, the strength of the partition walls is reduced, and the stability of the glass material is unfavorably reduced. If the amount exceeds 40% by weight, the stability of the glass material is undesirably reduced.

Barium oxide (BaO) is 2 to 15% by weight
It is preferable to mix in the range of. If it is less than 2% by weight,
It is difficult to control the glass baking temperature and electrical insulation, and if it exceeds 15% by weight, the stability of the glass material and the denseness of the partition walls are undesirably reduced.

Aluminum oxide (Al ₂ O ₃ ) is 10 to 2
It is preferable to mix in a range of 5% by weight. Aluminum oxide is added to increase the strain point of the glass material.
If the amount is less than 10% by weight, the strength of the partition walls is reduced. Also, 6
If the temperature is lower than 00 ° C., it becomes difficult to obtain a dense partition wall.

In addition to the above components, zinc oxide, calcium oxide, magnesium oxide and the like can be contained.

At this time, zinc oxide (ZnO) is 1.5 to 1
It is preferably contained in the range of 0% by weight. If it is less than 1.5% by weight, there is no effect on improving the denseness of the partition walls. If it exceeds 10% by weight, the temperature for baking on the glass substrate becomes too low to control, and the insulation resistance of the partition walls is undesirably low.

Calcium oxide (CaO) has the following effects in that the glass material is easily melted and the coefficient of thermal expansion is controlled.
It is preferable to mix in the range of 2 to 10% by weight. If it is less than 2% by weight, the strain point will be too low.

Magnesium oxide (MgO) is preferably contained in the range of 1 to 10% by weight for facilitating melting of the glass material and controlling the thermal expansion coefficient. 1
Exceeding 0% by weight is not preferred because the glass material is liable to devitrify.

The glass material may also contain titanium oxide, zirconium oxide, etc., but the amount is preferably less than 10% by weight. Zirconium oxide is effective in extending the pot life of the paste because of its excellent acid resistance. It is also effective in controlling the glass transition point, softening point and electrical insulation.

In the present invention, the glass material of the photosensitive paste is prepared by using the glass transition point of 450 to 550 ° C., the softening point of 500 to 600 ° C., and the thermal expansion coefficient of 75 to 90 × 10.
It is also possible to add inorganic fine particles to a glass material of ^-7 / K. That is, the aforementioned glass transition point 45
Assuming that the glass component contains 40 to 95% by weight of a glass material having a softening point of 500 to 600 ° C. and a thermal expansion coefficient of 75 to 90 × 10 ⁻⁷ / K and 5 to 60% by weight of inorganic fine particles, it is photosensitive. In the conductive glass paste method, the shrinkage ratio during firing after pattern formation is reduced, and the shape retention and accuracy of the partition wall pattern are improved. Further, the thermal expansion coefficient can be easily controlled, and the adhesion strength to the glass substrate is improved.
Further, since the control of the refractive index becomes easy, the pattern formability is improved.

Examples of the inorganic fine particles include at least one filler selected from the group consisting of alumina, zirconia, mullite, cordierite, spinel, titania, mullite and glass.

When the content of the inorganic fine particles is less than 5% by weight, the effect of reducing the firing shrinkage and controlling the coefficient of thermal expansion is small when forming the partition walls by the photosensitive paste method.

On the other hand, when the content of the inorganic fine particles exceeds 60% by weight, the partition walls after firing become inferior in terms of denseness, the partition walls have low strength, and defects such as peeling or falling off of the partition walls occur. May be. In addition, the adsorption of a small amount of water and the remaining of organic components in the partition walls may cause a decrease in discharge characteristics.

Particularly, when the inorganic fine particles have a glass transition point of 600
It is preferably a high melting point glass having a softening point of 600 to 850 ° C.

The average refractive index of the high melting point glass is 1.5 to 1.
8 is more preferable, and 1.5 to 1.68 is more preferable. This makes it easier to match the refractive index with the photosensitive organic component such as the photosensitive compound in the photosensitive paste, and improves the transmittance of the photosensitive paste (prevents scattering and reflection).
This is because high precision pattern formation is facilitated.

Further, the above-mentioned glass transition point of 450 to 55
The average refractive index n1 of the glass material having a softening point of 0 ° C. and a softening point of 500 to 600 ° C. and the average refractive index n2 of the high melting point glass preferably satisfy the following formula.

-0.05 ≦ n1−n2 ≦ 0.05 It is preferable that the refractive index and the photosensitive organic component in the photosensitive paste be easily adjusted and the partition wall pattern property be improved.

As the high-melting glass satisfying the above conditions, glass fine particles containing 10% by weight or more of silicon oxide and aluminum oxide are preferably mentioned, and it is necessary that the total amount of these is 50% by weight or more. It is effective for giving thermal characteristics.

As an example, there is a high melting point glass having the following composition.

SiO ₂ : 15 to 50% by weight B ₂ O ₃ : 5 to 40% by weight Al ₂ O ₃ : 10 to 50% by weight BaO: 2 to 15% by weight 0.4-2μ
Preferably, m and D50 have a particle size distribution of 1 to 3 μm, D90 of 3 to 8 μm and a top size of 10 μm or less. By setting the content in this range, the firing shrinkage rate can be reduced, and this is preferable for producing a partition wall having a low porosity. In addition, the unevenness in the longitudinal direction of the
m or less. When a powder having a large particle diameter is used for the high melting point glass, not only does the porosity increase,
It is not preferable because unevenness on the upper part of the partition wall is enlarged and erroneous discharge is caused.

Here, D10, D50 and D90 are the particle diameters of glass of 10% by volume, 50% by volume and 90% by volume, respectively, from a glass powder having a small particle diameter.

The high-melting glass is, for example, mixed at 900-1400 ° C.
After melting in, quenched, made into glass frit and then crushed,
It can be used as having the above particle size.

On the other hand, as a method for producing a glass material, for example, raw materials such as lithium oxide, silicon oxide, aluminum oxide, boron oxide, barium oxide and zinc oxide are mixed so as to have a predetermined composition, and the mixture is heated at 800 to 1200 ° C. After melting, quenched, made into glass frit and then crushed
Fine particles of 5 μm can be obtained. As a raw material, a high-purity carbonate, oxide, hydroxide, or the like can be used. Also, depending on the type and composition of the glass fine particles, 99.99%
The use of the above ultrahigh-purity alkoxide or organometallic raw materials and the use of fine particles homogeneously prepared by a sol-gel method are preferable in that a high electric resistance, a small number of pores, and a high strength partition wall can be obtained.

The particle diameter of the glass material used in the above is selected in consideration of the line width and height of the partition wall to be produced, but the 50% by weight particle diameter (average particle diameter, D50) is 2 to 4%. 0.0 μm and a top size of 30 μm or less. Further, the 10% by weight particle diameter (D10) is 0.6 to 1.5 μm, and the 90% by weight particle diameter (D90) is 4 μm.
-10 μm, top size 25 μm or less, specific surface area 1.
It is preferable to have 5 to 3.0 m < ² > / g. More preferably, the average particle size is 2.0 to 3.5 μm and the specific surface area is 1.5 to 3.0 m ² / g.

By using the glass particles having the above particle size distribution, the filling property of the glass material is improved,
Even if the glass material ratio in the photosensitive paste is increased, air bubbles are less likely to be entrained and unnecessary light scattering is small, so that a preferable partition pattern shape can be formed.

If the particle size of the glass fine particles is smaller than the above range, the specific surface area increases, so that the glass fine particles are easily aggregated, and the dispersibility in the organic component is reduced, so that bubbles are easily entrained. For this reason, light scattering increases, and the central part of the partition wall tends to be thick and the bottom part is insufficiently hardened. Further, if the particle size of the glass fine particles is larger than the above range, the bulk density of the powder is reduced, so that the filling property is reduced, the amount of the photosensitive organic component is insufficient, and bubbles are easily entrapped, which also tends to cause light scattering. In particular, when the average particle diameter is less than 2.0 μm and the specific surface area exceeds 3.0 m ² / g, the fine particles become too fine, and light is scattered at the time of exposure to cure the unexposed portion.

On the other hand, when the particle size distribution of the glass fine particles is within the above range, the shrinkage ratio of firing decreases because the filling ratio of the glass material is high, and the pattern shape does not collapse during firing, and the partition wall shape can be obtained stably. In addition, light is sufficiently transmitted at the time of exposure to ultraviolet light, and a uniform partition pattern having no line width difference between the upper and lower portions can be obtained.

In the photosensitive paste according to the present invention, the glass material described above, or the mixing ratio of the glass material and the inorganic fine particles / photosensitive organic component is 60/40 to 90/1.
It is preferably 0 (weight ratio). More preferably 6
5/35 to 85/15 (weight ratio). Here, the photosensitive organic component indicates a monomer, an oligomer or a polymer having a photosensitive functional group, and means a photopolymerization initiator, a sensitizer, and other components added as necessary.

If the ratio of the glass material or the ratio of the glass material and the inorganic fine particles is less than 60, the organic component hardly disappears at the time of firing, which causes coloring and peeling of the formed partition walls, which is not preferable. In addition, when forming a high-definition partition pattern, if the amount of the photosensitive organic component is large, the partition line width is increased, and it is difficult to obtain a desired line width. Furthermore, shrinkage during firing is large, and it is necessary to increase the pattern before firing in order to obtain a desired height, and the margin during formation is reduced.

If the ratio of the glass material or the ratio of the glass material and the inorganic fine particles is more than 90, bubbles easily enter the paste, causing light scattering, and the line width is unfavorably increased. In addition, due to the small amount of the three-dimensionally cured resin component composed of the photosensitive organic component, the curing of the entire pattern becomes insufficient, and the adhesion to the substrate during pattern formation is poor, and the pattern is easily peeled off.

Next, the photosensitive organic component will be described.

In the present invention, the photosensitive organic component is
It is a portion where the glass material and the inorganic fine particles are removed from the photosensitive paste.
40% by weight, more preferably 15 to 35% by weight, in addition to a photosensitive component selected from at least one of a photosensitive monomer, a photosensitive oligomer and a photosensitive polymer, a binder and a photopolymerization initiator. It is composed of an agent, a sensitizer, a sensitization aid, an ultraviolet light absorber, a polymerization inhibitor, a plasticizer, a thickener, an antioxidant, a dispersant, and other additives as necessary. As the photosensitive component, it is preferable to use a mixture of a photosensitive monomer and a photosensitive oligomer or a photosensitive polymer.

The sensitivity and resolution of the photosensitive paste mainly depend on the photosensitive organic components. These organic components play an important role in the exposure / development step in pattern formation, and also in the subsequent baking step. In
It must be rapidly pyrolyzed and disappear. Therefore, the photosensitive organic component must have excellent thermal decomposition properties in addition to the properties required for the photosensitive paste.

In the present invention, examples of the photosensitive monomer include a compound having an active carbon-carbon double bond, and a monomer having a vinyl group, an allyl group, an acrylate group, a methacrylate group, or an acrylamide group as a functional group. Functional and polyfunctional compounds are preferred. The photosensitive organic component preferably contains a polyfunctional acrylate compound and / or a polyfunctional methacrylate compound in an amount of 10 to 80% by weight. Since various kinds of compounds have been developed as the polyfunctional acrylate compound and / or the polyfunctional methacrylate compound, it is possible to select them from consideration of reactivity, refractive index and the like. Selection criteria include whether the paste has good properties such as stability and applicability, and whether a pattern with excellent sensitivity and resolution can be formed.On the other hand, the pattern formed by the glass component after firing is used. Conditions are added that do not color the object brown or black or affect its properties.

As a method of controlling the refractive index of the photosensitive organic component, a method of controlling the refractive index of the photosensitive monomer is simple, and therefore, the refractive index of the photosensitive monomer is 1.55 to 1.8.
It is preferred that From this point, as the photosensitive monomer, an acrylate or methacrylate monomer containing an aromatic ring such as a benzene ring or a naphthalene ring or a sulfur atom is preferably exemplified.

Further, the photosensitive component serves to improve the physical properties of the cured product formed by the photoreaction, adjust the viscosity of the paste, and controls the developability of the unexposed area. It is preferable to include an oligomer or a polymer, and these must also have the same properties as the photosensitive monomer. In addition, the photosensitive oligomer or polymer is a component that also contributes to the applicability of the photosensitive paste, and is also required to serve as a binder for dispersing the glass particles. Further, it is necessary that the photosensitive oligomer or polymer is also thermally decomposed and removed promptly in the firing step, and it is preferable to select a structure that is easily decomposed as the main chain molecular structure.

Examples of such a photosensitive oligomer or polymer include those having a carbon chain skeleton obtained by polymerization or copolymerization of a component selected from compounds having a carbon-carbon double bond. As the monomer to be copolymerized, an unsaturated carboxylic acid or the like is preferably exemplified in that an unexposed portion can be easily developed with an aqueous alkali solution after pattern exposure.

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

The oligomer or polymer having an acid group such as a carboxyl group in the side chain has an acid value of 30 to 15
It is preferable to control so as to be 0, preferably in the range of 50 to 120. When the acid value exceeds 150,
The allowable development width is reduced. If the acid value is less than 30, the solubility of the unexposed portion in the developer tends to decrease.

In the present invention, as the photosensitive oligomer or polymer, a weight average molecular weight of 500 to 10 containing a carboxyl group and a carbon-carbon double bond in the molecule is particularly preferable.
It is most preferable to use 10,000 oligomers or polymers, but in order to introduce a carbon-carbon double bond, an oligomer or a polymer having a carboxyl group in the side chain as described above may be added to an ethylenic polymer having a glycidyl group or an isocyanate group. A method of performing an addition reaction of an unsaturated compound, acrylic acid chloride, methacrylic acid chloride or allyl chloride is applied. The number of carboxyl groups for developing with an aqueous alkali solution and the number of ethylenically unsaturated groups that render the oligomer or polymer photosensitive can be freely selected depending on the reaction conditions.

The photosensitive organic component may further contain a binder component. As the binder, polyvinyl alcohol, polyvinyl butyral, a methacrylate polymer, an acrylate polymer, a copolymer thereof, or the like is used. be able to.

Further, since none of the above-mentioned photosensitive monomers, photosensitive oligomers or polymers, and binders have the ability to absorb energy of actinic rays, it is necessary to add a photopolymerization initiator or a sensitizer in order to initiate a photoreaction. is there.

The pattern formation by the photosensitive paste is to polymerize and crosslink the photosensitive components (monomers, oligomers, and polymers) in the exposed portions to make them insoluble in a developing solution. Since it is radically polymerizable, the photopolymerization initiator is selected from those that generate radical species. There are mechanically different types of photopolymerization initiators such as a one-molecule direct cleavage type, an electron transfer between ion pairs, a hydrogen abstraction type, and a two-molecule composite system. It is preferable to use a compound selected from For example, benzoin alkyl ether, α, α-dimethoxy-α-morpholinoacetophenone, α, α-dimethoxy-α-phenylacetophenone and the like can be mentioned. In addition, peroxides, phosphine oxides, sulfur compounds, halogen compounds and the like are also used.
One or more of these can be used. The photopolymerization initiator is usually used in an amount of 0.05 to 1 based on the photosensitive component.
0% by weight, more preferably 0.1 to 10% by weight. In the present invention, considering the amount of the glass material in the photosensitive paste, 2 to 1% based on the photosensitive component.
It is preferable to use 0% by weight.

Further, by using a sensitizer together with a photopolymerization initiator, the sensitivity can be improved (chemical sensitization) or the wavelength range effective for the reaction can be expanded (spectral sensitization). Although there are various mechanisms of action of the sensitizer, those called triplet sensitizers are most often used. Specifically, hydrocarbon compounds, amino-nitro compounds, quinones, xanthones, anthrones, ketones, organic dyes,
Among them, those having an action as a photopolymerization initiator are also included. In the present invention, a compound selected from xanthones is preferably used, and examples thereof include 2,4-diethylthioxanthone and isopropylthioxanthone. These can be used alone or in combination of two or more.

When a sensitizer is added to the photosensitive paste,
Usually, the addition amount is 0.05 to 10% by weight, more preferably 0.1 to 10% by weight, based on the photosensitive component, but in the present invention, the photosensitive component is taken into consideration in consideration of the amount of the glass material. Is preferably used in an amount of 2 to 10% by weight.

If the photopolymerization initiator and the sensitizer are too small, sufficient sensitivity cannot be obtained. However, it is possible to increase the sensitivity by increasing the number. However, if the degree of polymerization of the cured portion is sufficiently high, In other words, there is a possibility that the residual ratio of the exposed portion may be reduced, and inconveniences such as the occurrence of unnecessary curing between patterns and the formation of a residual film may occur. It is necessary to use appropriate amounts of the photopolymerization initiator and the sensitizer in order to form a pattern having an excellent shape with an appropriate sensitivity.

Further, the addition of an ultraviolet absorber to the photosensitive paste is effective for narrow pitch, narrow line width and high partition walls, that is, pattern processing of an excellent shape.
By adding a compound having a high ultraviolet light absorption effect, a high aspect ratio, high definition, and high resolution can be obtained. UV absorbers composed of organic dyes, especially 350
Those having a high extinction coefficient in the wavelength range of -450 nm are preferably used.

Specific examples include azo dyes, aminoketone dyes, xanthene dyes, quinoline dyes, anthraquinone dyes, benzophenone dyes, diphenylcyanoacrylate dyes, triazine dyes, p-aminobenzoic acid dyes and the like. Can be used. Among these, azo dyes and benzophenone dyes are preferred. Even when an organic dye is added as an ultraviolet light absorber, it does not remain in the insulating film after firing, so that a decrease in insulating properties can be reduced, which is preferable.

The amount of the organic dye added as an ultraviolet light absorber is preferably 0.05 to 0.5% by weight based on the total amount of the glass material and the inorganic fine particles dispersed in the photosensitive paste. The ultraviolet light absorber may be prepared by dissolving a solution in an organic solvent in advance and kneading the solution when preparing a paste, or by mixing glass particles in the dye solution and drying. In the latter method, a so-called capsule-shaped glass powder in which the surface of each glass fine particle is coated with an organic dye film can be produced. Thereby, reflection at the interface of the glass fine particles is suppressed, and unnecessary photoreaction is prevented, so that it is estimated that thickening of the pattern and generation of a residual film are prevented.

Further, if necessary, a polymerization inhibitor for improving thermal stability during storage may be added to the photosensitive paste.
An antioxidant for preventing oxidation of the acrylic copolymer and other plasticizers can be added.

The photosensitive paste contains various components such as, for example, glass fine particles, an ultraviolet absorber, a photosensitive monomer, a photosensitive oligomer or polymer, a photopolymerization initiator, a sensitizer, other additives and a solvent. Then, the mixture is homogeneously mixed and dispersed by a three-roller or a kneading machine to produce a mixture. The viscosity of the paste is adjusted by the addition ratio of glass fine particles, a photosensitive component, a thickener, an organic solvent, a plasticizer, and the like, and its range is from 2000 to 200,000 cps (centipoise). For example, in order to obtain a film thickness of 10 to 20 μm by applying once to a glass substrate by a screen printing method, 5
10,000 to 200,000 cps is preferable. 20 for spin coating
In the case of using a blade coater method, a die coater method, or the like, the viscosity is preferably 10,000 to 20,000 cps. Therefore, it is preferable to use an organic solvent according to the application method and adjust the viscosity to apply.

The organic solvents used at this time include methyl cellosolve, ethyl cellosolve, butyl cellosolve,
Methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol,
For example, isopropyl alcohol, tetrahydrofuran, dimethyl sulfoxide, γ-butyrolactone, or an organic solvent mixture containing at least one of these is used.

Next, a method for manufacturing the substrate for a plasma display of the present invention using the photosensitive paste will be described with reference to specific examples.

First, a photosensitive paste is applied to a glass substrate. As a coating method, a general method such as a screen printing method, a bar coater method, a roll coater method, a die coater method, and a doctor blade method can be used. The coating thickness can be adjusted by selecting the number of coatings, the screen mesh for screen printing, and the viscosity of the paste.

After applying the photosensitive paste onto a glass substrate or a dielectric layer formed on a surface-treated surface as required, exposure is performed using an exposure apparatus. The exposure is performed through a photomask, as in the case of ordinary photolithography technology. At this time, either a method in which a photomask is adhered to the surface of the coating film of the photosensitive paste or a proximity exposure method in which a photomask is provided at a predetermined interval may be used.

The actinic rays used for the exposure are most preferably ultraviolet rays. As the light source, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a halogen lamp and the like are used. It is common to use a proximity exposure machine using parallel light beams with an ultra-high pressure mercury lamp as a light source. Exposure conditions vary depending on the applied thickness of the photosensitive paste.
20 seconds using an ultra-high pressure mercury lamp with an output of 00 mW / cm ²
Exposure is performed for 30 minutes.

After exposure, development is carried out by utilizing the difference in solubility between the exposed portion and the unexposed portion in the developing solution.
An immersion method, a spray method, a brush method, or the like is used. As a developer, a solution in which an organic component in a photosensitive paste, particularly a photosensitive oligomer or polymer can be dissolved is used. The photosensitive oligomer or polymer of the photosensitive paste used in the present invention preferably has a carboxyl group in the side chain as described above, and in this case, it can be developed with an aqueous alkali solution.

As the aqueous alkali solution, an aqueous solution of sodium hydroxide, sodium carbonate, calcium hydroxide or the like can be used, but it is preferable to use an organic alkali aqueous solution since the alkaline component can be easily removed at the time of firing.

As the organic alkali, a general amine compound can be used. Specific examples include tetramethylammonium hydroxide, trimethylbenzylammonium hydroxide, monoethanolamine, diethanolamine and the like. The concentration of the alkaline aqueous solution is preferably from 0.05 to 1% by weight, more preferably from 0.1 to 0.5% by weight. If the alkali concentration is too low, the soluble portion will not be completely removed, and if the alkali concentration is too high, the pattern in the exposed portion may be peeled off or eroded. The development is preferably performed at a temperature of 20 to 50 ° C. in terms of process control.

The partition wall pattern formed from the coating film of the photosensitive paste through the exposure and development steps is then fired in a firing furnace to thermally decompose the organic components to completely remove them and simultaneously melt the glass components. To form a partition made of an inorganic glass material. The firing atmosphere and temperature vary depending on the properties of the paste and the substrate, but firing is performed in an oxygen-containing atmosphere such as in air. As the firing furnace, a batch-type firing furnace or a belt-type continuous firing furnace can be used.

By forming the partition walls using the photosensitive paste composed of the glass component having the above-mentioned thermal characteristics, the carbon content of the partition walls is reduced to 0.1% by weight or less, so that the partition walls have a high aspect ratio and a high definition. In addition, a plasma display substrate having barrier ribs free from defects such as coloring and peeling can be easily manufactured.

Hereinafter, the present invention will be described specifically with reference to examples. However, the present invention is not limited to this. The concentrations in the examples are% by weight unless otherwise noted.

The abbreviations in the examples mean the following.

X-4007: 40% methacrylic acid, 30
% Methyl methacrylate, 30% styrene, and a weight average molecular weight of 430 obtained by addition-polymerizing 0.4 equivalent of glycidyl methacrylate to the carboxyl group.
00, photosensitive polymer with an acid value of 95.

MGP400: a compound represented by the following chemical formula:

[0097]

Embedded image GX: a compound represented by the following chemical formula.

[0098]

Embedded image IC-369: Irgacure-369 (product of Ciba-Geigy) 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1 DETX-S: 2,4-diethylthioxanthone

[0099]

Example 1 A photosensitive paste was prepared with the following composition ratio (value based on a dry coating film).

The glass fine particles had a composition (analytical value) of 6.7% of lithium oxide, 22% of silicon oxide, and 32% of boron oxide.
%, Barium oxide 3.9%, aluminum oxide 19%,
A material having 2.2% of zinc oxide, 5.5% of magnesium oxide, and 4.1% of calcium oxide was prepared.

The glass transition point of the fine glass particles is 4
97 ° C, softening point 530 ° C, coefficient of thermal expansion 75 × 10 ^-7 /
K, D10, D50, D90 and the top size were 0.9 μm, 2.6 μm, 7.5 μm, and 22 μm, respectively. The specific surface area is 1.92 m ² / g, and the refractive index is 1.5.
Nine.

The glass fine particles of this composition were coated with an ultraviolet absorbent. Sudan IV (azo organic dye Tokyo Chemical Industry Co., Ltd.)
Was used in an amount of 0.08% based on the glass fine particles.

As a photosensitive organic component, a photosensitive polymer (X-40) was added to 70 parts by weight of the glass fine particles thus treated.
07) 15 parts by weight, photosensitive monomer (MGP400) 15
3 parts by weight of a photopolymerization initiator (IC-369) and 1.8 parts by weight of a sensitizer (DETX-S) were blended to prepare a photosensitive paste.

The photosensitive paste was prepared by mixing the organic components and the glass particles coated with an ultraviolet absorber and kneading them with three rollers. The viscosity was adjusted by the amount of γ-butyrolactone, but the amount of the solvent in the paste was adjusted to 10 to 40%.

Next, the obtained photosensitive paste was uniformly applied on a high strain point glass substrate PD-200 (manufactured by Asahi Glass) by screen printing to prepare a sample for pattern formation. The coating and drying are repeated several times to eliminate pinholes and the like on the coating film.
It was applied so that Drying was performed at 80 ° C. for 10 minutes. After applying to a predetermined thickness, it was dried at 80 ° C. for 40 minutes.

Next, the sample for pattern formation was exposed with an exposure gap of 30 μm via a photomask (striped pattern, pattern pitch 150 μm, line width 20 μm) for the purpose of forming a partition pattern for a plasma display. Exposure was performed with an ultra-high pressure mercury lamp having an output of 50 mW / cm ² for 1 J / cm ² ultraviolet light exposure. afterwards,
3% 0.2% aqueous solution of monoethanolamine in shower
The film was developed by applying for 00 seconds, and further washed with water using a shower spray to remove a space portion that was not photocured, thereby forming a stripe-shaped partition wall pattern on a glass substrate.

The glass substrate on which the processing of the partition pattern was completed was dried at 80 ° C. for 15 minutes, heated to 570 ° C. at a heating rate of 200 ° C./hour, and kept at that temperature for 15 minutes to form a partition. The firing caused a shrinkage of about 30%.

On the way, when the pattern of the pattern formed by subjecting the photosensitive paste coating film to mask exposure and development was observed with an electron microscope, the cross-sectional shape was a trapezoidal shape slightly expanding toward the bottom, and The width was 40 μm.
There was no residual film in the space portion, and a partition pattern having a high aspect ratio was obtained.

When the carbon content in the partition walls obtained after firing was analyzed, the total carbon content was 0.042% by weight.
And a white partition wall was obtained, and no defects such as peeling were observed.

Example 2 A photosensitive paste was prepared in the following composition ratio (value based on a dry coating film).

First, as glass fine particles, the composition (analytical value) was 4.5% lithium oxide, 15% silicon oxide, 30% boron oxide, 11% barium oxide, 11% aluminum oxide, 6.7% zinc oxide, Magnesium oxide 9.1
% And calcium oxide of 8.6%. These glass fine particles are similar in composition to those used in Example 1, but differ in the amount of lithium oxide and the like. Therefore, the glass transition point is 486 ° C., the softening point is 523 ° C., and the thermal expansion coefficient is 85 × 10 5 ^-7 / K, refractive index was 1.59. Particle size is D10, D50, D90, top size is 0.9μ in order
m, 2.3 μm, 7.6 μm and 22 μm. Further, the specific surface area was 2 m ² / g.

Glass fine particles of this composition were coated with an ultraviolet absorbing agent and used. Sudan IV (azo organic dye, manufactured by Tokyo Kasei Kogyo Co., Ltd.) was used as an ultraviolet light absorber in an amount of 0.1% based on the glass fine particles.

A photosensitive polymer (X-4007) was added as an organic component to 70 parts by weight of the glass fine particles thus treated.
15 parts by weight, 15 parts by weight of photosensitive monomer (GX), 3 parts by weight of photopolymerization initiator (IC-369) and sensitizer (DET)
X-S) 1.8 parts by weight. The photosensitive monomer GX used here gives a photosensitive paste with high sensitivity, but a photosensitive paste combined with glass fine particles having a low glass transition point is a component that easily causes the partition walls to be colored in the firing step.

Using this photosensitive paste combined with the glass fine particles having the above-mentioned composition, processing and patterning and baking were performed in the same manner as in Example 1, and it was confirmed that there was no coloring and no peeling occurred. . The analytical value of the carbon content of the obtained partition wall was 0.088% by weight, and it was almost white.

Example 3 The same operation as in Example 1 was carried out except that 20% by weight of the inorganic filler was added to 80% by weight of the glass powder.

The composition of the inorganic filler is 38% of SiO ₂ ,
₂ O ₃ 9%, BaO 5%, Al ₂ O ₃ 35%, ZnO
3%, MgO 5%, CaO 5%, average particle size 2.7
μm, refractive index 1.58, spherical, glass transition point 652 ° C
Was used.

Example 1 except that the firing temperature was raised by 10 ° C.
When patterning and baking were performed in the same manner as in the above, it was confirmed that there was no coloring and no peeling occurred. The analytical value of the carbon content of the obtained partition wall was 0.03% by weight,
It was almost white.

Example 4 The procedure of Example 1 was repeated, except that 20% by weight of the inorganic filler was added to 80% by weight of the glass powder.

For the inorganic filler, titania having an average particle size of 0.24 μm was used.

Example 1 except that the firing temperature was raised by 10 ° C.
When patterning and baking were performed in the same manner as in the above, it was confirmed that there was no coloring and no peeling occurred. The analytical value of the carbon content of the obtained partition wall was 0.02% by weight,
It was almost white.

Comparative Example As an organic component, a photosensitive polymer (X-4007) 7.5 was used.
The same procedure as in Example 2 was carried out except that the amount of the photosensitive monomer (GX) was 22.5 parts by weight.

As a result of patterning and firing, blackening and peeling occurred.

When the carbon content of the obtained partition wall was measured, it was 0.2% by weight.

[0124]

The substrate for a plasma display of the present invention is a substrate on which partition walls are formed, and the carbon content of the partition walls is 0.1% by weight or less, so that pattern processing with high aspect ratio and high precision is performed. This is an excellent plasma display substrate without any defects such as coloring and peeling of the partition walls.

For this reason, when a plasma display panel is manufactured using the plasma display substrate of the present invention, it exhibits high luminance and high efficiency discharge characteristics.
An excellent product with a long life is obtained.

Claims (13)

[Claims] 1. A substrate for a plasma display, wherein a partition wall is formed, wherein the carbon content of the partition wall is 0.1% by weight or less. 2. The partition according to claim 1, wherein the height of the partition is 60 to 160 μm, and the line width of the partition is 20 to 100 μm.
The substrate for a plasma display according to the above. 3. The plasma display substrate according to claim 2, wherein the pitch of the partition walls is 80 to 460 μm. 4. The partition wall has a glass transition point of 450 to 550 ° C.
Softening point 500-600 ° C and coefficient of thermal expansion 75-90 × 1
The plasma display substrate according to any one of claims 1 to 3, wherein the substrate is made of a glass material of ^0-7 / K. 5. The partition according to claim 1, wherein said partition is made of a glass material having an average refractive index of 1.5 to 1.8.
4. The substrate for a plasma display according to any one of 4. 6. The plasma display substrate according to claim 1, wherein the glass material constituting the partition wall has the following composition. Lithium oxide: 3 to 10% by weight Silicon oxide: 10 to 30% by weight Boron oxide: 20 to 40% by weight Barium oxide: 2 to 15% by weight Aluminum oxide: 10 to 25% by weight 7. The partition wall has a glass transition point of 450 to 550 ° C.
Softening point 500-600 ° C and coefficient of thermal expansion 75-90 × 1
0 ^-7 / K 40 to 95 wt% of glass material is a plasma display substrate according to claim 6 any one of claims, characterized in that is composed of glass component comprising inorganic fine particles 5 to 60 wt% . 8. The plasma according to claim 7, wherein the inorganic fine particles are at least one filler selected from the group consisting of alumina, zirconia, mullite, cordierite, spinel, titania, mullite and glass. Display substrate. 9. An inorganic fine particle having a glass transition point of 600 to 7
9. The substrate for a plasma display according to claim 8, wherein the substrate is a high melting point glass having a softening point of 600 to 850 [deg.] C. 10. The plasma display substrate according to claim 9, wherein the average refractive index n1 of the glass material and the average refractive index n2 of the high melting point glass satisfy the following expression. −0.05 ≦ n1−n2 ≦ 0.05 11. The high melting point glass has an average refractive index of 1.5 to 1.
The substrate for a plasma display according to claim 9, wherein: 12. The substrate for a plasma display according to claim 9, wherein the high melting point glass has the following composition. Silicon oxide: 15 to 50% by weight Boron oxide: 5 to 40% by weight Aluminum oxide: 10 to 50% by weight Barium oxide: 2 to 15% by weight 13. A glass transition point of 450 to 550 ° C., a softening point of 500 to 600 ° C. and a coefficient of thermal expansion of 75 to 90 × 10 ^-7 /
A photosensitive paste comprising a glass material of K and a photosensitive organic component as essential components is coated on a substrate, and a partition pattern is formed by a photolithography method, followed by baking. Production method.