JP2007207464A - Backboard for plasma display and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a backboard for plasma display with little fear of a barrier-rib chip due to drop impact. <P>SOLUTION: The backboard for plasma display is equipped with a glass substrate, stripe-shaped address electrodes fitted on the glass substrate, a dielectric layer covering the address electrodes, and barrier ribs containing main barrier ribs at least parallel with the address electrodes, with a ten-point average roughness Rz (μm) of the surface of a tiptop part of the barrier ribs and an average length Sm (μm) of a contour curve element satisfying formula (1): 8≤RSm≤3.0 and formula (2): 1.2≤Rz/RSm≤2.5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a back plate for a plasma display and a manufacturing method thereof. More specifically, the present invention relates to a back plate for a plasma display that is unlikely to cause a defect of a partition wall defect due to a drop impact, and a manufacturing method thereof.

  Plasma display panels (hereinafter abbreviated as PDP) are rapidly penetrating the global display market as large-screen thin displays. The major features of PDP are (A) a self-luminous device with excellent "viewing angle", "responsiveness", and "color reproducibility", and (B) the amount of light can be adjusted flexibly according to the image, and ecology From the standpoint, it is an optimal device that achieves both high performance and power saving, (C) it is excellent in production efficiency and cost power as a large-sized display, and (D) it can cope with further enlargement in the future. For example, PDPs are increasingly expected not only as consumer televisions but also as multipurpose displays for commercial / educational / medical purposes.

  The PDP generates plasma discharge between electrodes in a discharge space provided between a front glass substrate (hereinafter referred to as a front plate) and a rear glass substrate (hereinafter referred to as a back plate), and is enclosed in the discharge space. Display is performed by irradiating phosphors provided in the discharge space with ultraviolet rays of 147 nm and 172 nm generated from a discharge gas such as Xe-Ne mixed gas. In a typical PDP, the front plate has a scan electrode, a sustain electrode, a dielectric layer, and a protective film on the substrate, and the back plate has an address electrode, dielectric layer, barrier rib, and phosphor layer on the substrate. ing. The barrier ribs provided on the back plate play a role of suppressing the spread of discharge to a certain region, causing display to be performed in a specified cell, and at the same time ensuring a uniform discharge space. It is formed in a stripe shape or a lattice shape having a thickness of 120 μm and a height of 50 to 150 μm. In addition, the partition wall is formed by applying a paste made of a mixture of an organic material mainly composed of an organic binder and an inorganic material mainly composed of glass on a glass substrate, patterning the material by a sandblasting method, a photolithography method, or the like, and then firing the paste. Often formed.

By the way, the partition provided on the back plate faces the front plate due to the structure of the PDP, and a large force is generated between the front plate and the partition when a large load such as a drop impact is applied to the PDP. In this case, if the impact resistance of the partition walls is low, there is a problem that the partition walls are chipped and the PDP cell is not lit. Therefore, development of a PDP structure that improves impact resistance of partition walls and is resistant to impact has been performed. For example, a method in which the top of the partition wall is in a semi-sintered state, and even if the partition wall collides with the front plate due to impact, only the top portion of the partition wall is finely crushed to prevent cell unlighting due to partition wall chipping (Patent Documents 1 and 2). A method has been developed in which a protrusion made of a transparent dielectric material is provided on the main partition wall and the auxiliary partition wall so that the partition wall and the front plate are in contact with each other to prevent chipping of the partition wall in the vicinity of the discharge portion (Patent Document 3). However, in these methods, due to the introduction of moisture and carbon dioxide into the PDP panel due to the semi-sintered porous partition walls, defective light emission occurs in the PDP panel, or the lighting of the panel is affected by protrusions. There was a problem that it was difficult to manufacture a good PDP. In addition, as a method for preventing local protrusion of the partition wall, which is a starting point of partition wall chipping, an example in which a partition wall having a good surface roughness is formed using a fine filler has been reported (Patent Document 4). However, the fine filler aggregated and a large bulge was generated at the top of the partition wall. Therefore, a large crack ran due to the impact, and the generation of the partition wall chipping was not improved.
JP 2003-123657 A JP 2000-149772 A JP 2003-249173 A JP 2002-358900 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a plasma display back plate and a method for manufacturing the same, which are unlikely to cause partition wall chipping due to a drop impact.

That is, the present invention is for a PDP having a glass substrate, a stripe-shaped address electrode provided on the glass substrate, a dielectric layer covering the address electrode, and a partition including at least a main partition parallel to the address electrode. A back plate, wherein the point average roughness Rz (μm) of the top surface of the main partition wall and the average length Sm (μm) of the contour curve element satisfy the following formulas (1) and (2): The present invention relates to a display back plate.
1.8 ≦ RSm ≦ 3.0 (1)
1.2 ≦ Rz / RSm ≦ 2.5 (2)
In addition, the method for manufacturing the back plate for PDP is provided through a step of applying a glass paste containing at least the inorganic powder containing a low-melting glass powder and a filler and an organic component on the glass substrate, and a baking step. The average particle diameter of the filler contained in the paste used for the uppermost layer of the partition walls is Df ₅₀ (μm), and the average particle diameter of the low-melting glass powder is Dg ₅₀ (μm) satisfying the following formula (3): The maximum particle diameter Dg _TOP (μm) of the melting point glass powder is 5 μm or less, and further comprises a main partition and an auxiliary partition that intersects the main partition, The main partition has a two-layer structure, and the volume content of the filler relative to the total inorganic powder in the glass paste used for the lower layer of the main partition is the glass layer used for the upper layer of the main partition. It is a manufacturing method of the PDP for the back plate of the large Toko and features than contents volume percentage of fillers with respect to the total inorganic powder in the strike.
0.5 <Dg ₅₀ ≦ Df ₅₀ <3.0 (3)

  ADVANTAGE OF THE INVENTION According to this invention, the back plate for plasma displays which cannot produce a partition chip | tip easily by a drop impact can be provided.

The present invention relates to a glass substrate, a stripe-shaped address electrode provided on the glass substrate or a geometric pattern on the stripe, a dielectric layer covering the address electrode, and at least parallel to the address electrode. A back plate for PDP having a partition including a main partition wall, wherein a ten-point average roughness Rz (μm) of the partition top surface and an average length RSm (μm) of the contour curve element are expressed by the following formulas (1) and ( 2) It is related with the backplate for PDP characterized by satisfy | filling.
1.8 ≦ RSm ≦ 3.0 (1)
1.2 ≦ Rz / RSm ≦ 2.5 (2)
The average length RSm (μm) of the contour curve elements of the main partition wall top surface of the PDP back plate of the present invention satisfies the formula (1). When RSm is 3.0 μm or less, it means that a large number of fine protrusions are formed on the top of the partition wall. By forming a large number of contact points with the front plate of the fine protrusions, the force generated by the impact can be reduced. Disperses and can suppress partition wall chipping. When the RSm value is smaller than 1.8 μm, the specific surface area of the partition increases, and when the back plate is made into a PDP panel, it is easy to bring moisture and carbon dioxide into the panel, and when the PDP emits light, the display area emits light It is easy to cause unevenness. When the RSm value is larger than 3.0 μm, the number of contact points with the front plate is reduced, the force due to the impact is locally increased, and when the impact is applied and the partition is cracked, a large fragment of the partition It is easy to produce. Large scattered pieces will fly off the phosphor layer and cause unlit cells. Moreover, it is preferable that the back plate for PDP by this invention is the range of Formula (2). When Rz / RSm is in the range of the formula (2), an appropriate protrusion that buffers the impact can be determined. On the other hand, if Rz / RSm is smaller than 1.2, there is no minute protrusion formed on the top of the partition to buffer the impact, and the partition that collides with the front plate due to the impact is likely to be destroyed. When Rz / RSm is larger than 2.5, the specific surface area of the partition wall becomes too large, and when the back plate is made into a PDP panel, it is easy to bring moisture and carbon dioxide into the panel, and is displayed when the PDP emits light. It is easy to cause uneven light emission in the area. Here, the Rz and RSm values, which are the surface roughness values of the top of the partition wall, can generally be measured with a stylus type surface roughness measuring device, an atomic force microscope, a laser displacement meter, a scanning probe microscope, and a laser microscope. In the present invention, an ultradeep microscope vK-8500 manufactured by Keyence Co. was used to calculate from an average value obtained by measuring 10 times a measurement magnification of 50 times, a measurement pitch of 0.1 μm, and a measurement length of 100 μm at the top of the main partition wall.

  Below, the manufacturing method of the backplate for PDP of this invention is demonstrated along a preparation procedure.

  As the substrate used for the back plate as the display member of the present invention, soda glass, heat resistant glass for PDP, and the like can be used. Specifically, PD200 manufactured by Asahi Glass Co., Ltd. and Nippon Electric Glass Co., Ltd. PP8 etc. are mentioned.

  An almost striped address electrode is formed on the substrate with a metal such as silver, aluminum, chromium or nickel. Here, the almost stripe shape refers to a stripe pattern or a pattern in which the line width of a part of the stripe pattern is changed.

  As a method for forming an electrode, a metal paste mainly composed of these metal powders and an organic binder is printed in an electrode pattern by screen printing, or a photosensitive metal paste using a photosensitive organic component as an organic binder. After applying the film, the electrode pattern is exposed using a photomask corresponding to the pattern, unnecessary portions are dissolved and removed in a development process, and further heated and baked at 400 to 600 ° C. to form an electrode pattern. A photosensitive paste method can be used.

  Next, a dielectric layer is formed so as to cover the address electrodes. The dielectric layer can be formed by applying a glass paste containing glass powder and an organic binder as main components so as to cover the address electrodes and then baking at 400 to 600 ° C. The glass powder used for the glass paste used for forming the dielectric layer contains at least one of lead oxide, bismuth oxide, zinc oxide and phosphorus oxide, and these are 20% by mass or more based on the whole glass powder. By doing so, firing at 600 ° C. or less becomes easy, and by setting it to 80% by mass or less, crystallization can be prevented and a decrease in transmittance can be prevented.

  The partition wall is formed by using a screen paste, a sand blast method, a photosensitive paste method (a photo paste method), a glass paste containing an inorganic powder and an organic component including a low melting glass powder and a filler on the above-described address electrode and a substrate provided with a dielectric layer. Lithography method), mold transfer method, lift-off method, etc. are formed by forming a barrier rib pattern including at least main barrier ribs parallel to the address electrodes, baking, and removing organic components. For reasons of control, uniformity, etc., the so-called photosensitive paste method (photolithographic method) in which a photosensitive paste is applied on a substrate, dried to form a photosensitive paste film, and exposed and developed through a photomask. The present invention is preferably applied to the method for producing a PDP back plate.

  The barrier ribs of the present invention have at least main barrier ribs parallel to the address electrodes, but may have auxiliary barrier ribs that cross the main barrier ribs. The main partition wall is a partition wall that can be coated with a photosensitive paste once or twice on the substrate, and the coating film is exposed and developed to form a partition wall pattern. On the other hand, a back plate having auxiliary barrier ribs is coated with a photosensitive paste, crossed address electrodes and exposed with a photomask, and further coated with a photosensitive paste to form a coating film having an upper and lower two-layer structure. Form a partition pattern by forming and exposing with a photomask in parallel with the address electrode and developing the exposed substrate, or applying a photosensitive paste to the substrate twice to form a coating film having an upper and lower two-layer structure Is exposed with a photomask so as to cross the address electrode, and exposed with a photomask in parallel with the address electrode, and developed to form a barrier rib pattern.

  The step of applying the photosensitive paste to the substrate is preferably once or twice because the manufacturing process becomes complicated and the yield may be lowered if it is repeated three times or more. And when a main partition is two layers, 2-20 micrometers is preferable and the upper layer has more preferable 5-16 micrometers. When the thickness is less than 2 μm, the height variation of the partition walls increases. On the other hand, when the thickness exceeds 20 μm, the effect on the drop impact is saturated.

  The inorganic component of the paste used in the method for producing the PDP back plate of the present invention is mainly composed of a low-melting glass and a filler. Here, the low melting point glass is a fine particle and is a glass that is melted in a firing step generally performed at 350 to 700 ° C., and the glass transition temperature is preferably 350 to 500 ° C., preferably 380 to 450 ° C. It is more preferable that Further, the glass softening point is preferably 400 to 580 ° C, more preferably 450 to 550 ° C. When the glass transition temperature and the glass softening point are within these ranges, a partition layer having a small distortion of the substrate during firing can be obtained. As a specific example of the low-melting glass, glass containing silicon oxide, boron oxide, and aluminum oxide as essential components is particularly preferable.

  The silicon oxide is preferably blended in the range of 3 to 60% by weight in the inorganic fine particles, and more preferably 10 to 40% by weight. If it is less than 3% by weight, the denseness, strength and stability of the glass layer are lowered, and the thermal expansion coefficient tends to be within a desired range, making it difficult to prevent mismatch with the glass substrate. On the other hand, if it exceeds 60% by weight, the thermal softening point tends to be high and baking onto the glass substrate tends to be difficult.

  Boron oxide is preferably blended in the range of 5 to 50% by weight in the inorganic fine particles from the viewpoint of improving electrical, mechanical and thermal properties such as electrical insulation, strength, thermal expansion coefficient, and denseness of the insulating layer. 10 to 40% by weight is more preferable. If the blending amount is less than 50% by weight, the stability of the glass tends not to be maintained.

  Further, a glass paste having a temperature characteristic suitable for patterning on a glass substrate by containing at least one of bismuth oxide, lead oxide, and zinc oxide in a total of 5 to 50% by weight in inorganic fine particles. Is preferable, and 10 to 30% by weight is more preferable. If the blending amount exceeds 50% by weight, it tends to be difficult to control the linear expansion coefficient. In particular, when glass fine particles containing bismuth oxide are used as the oxide, advantages such as a long pot life of the paste can be obtained. As the bismuth-based glass fine particles, glass powder having the following composition is preferably used.

Bismuth oxide: 10 to 40% by weight
Silicon oxide: 3 to 50% by weight
Boron oxide: 10-40% by weight
Barium oxide: 8-20% by weight
Aluminum oxide: 10-30% by weight
Moreover, you may use the glass microparticles | fine-particles which contain 3-20 weight% at least 1 type among lithium oxide, sodium oxide, and potassium oxide, More preferably, 3-15 weight%. When the addition amount of the alkali metal oxide is larger than 20% by weight, it tends to be difficult to improve the stability of the paste. Of the above three types of alkali metal oxides, lithium oxide is particularly preferred from the viewpoint of paste stability. As the lithium glass fine particles, for example, glass powder having the following composition is preferably used.

Lithium oxide: 2 to 15% by weight
Silicon oxide: 15-50% by weight
Boron oxide: 15-40% by weight
Barium oxide: 2 to 15% by weight
Aluminum oxide: 6-25% by weight
In addition, if glass fine particles containing both metal oxides such as lead oxide, bismuth oxide and zinc oxide and alkali metal oxides such as lithium oxide, sodium oxide and potassium oxide are used, with a lower alkali content, The thermal softening temperature and linear expansion coefficient can be easily controlled.

  The filler refers to fine particles that do not melt the coating film of the photosensitive paste even in the baking step, and remain in the finely patterned barrier ribs, and has an effect of maintaining the shape of the barrier rib pattern. Specific examples of the filler include high melting point glass fine particles and ceramic fine particles such as silicon oxide, aluminum oxide, barium oxide, calcium oxide, magnesium oxide, titanium oxide, zinc oxide, zirconium oxide and complex oxides thereof. It is necessary to have a high softening point that does not melt even during firing. Among these, from the viewpoint that the linear expansion coefficient can be easily controlled, glass fine particles, a composite oxide of silicon oxide and titanium oxide, and the like are preferable. As the glass fine particles, high melting point glass fine particles are more preferable. The softening point of the filler is preferably 600 to 2000 ° C, more preferably 650 to 2000 ° C. When the softening point of the filler is less than 600 ° C., the shape of the partition tends to collapse in the firing step. On the other hand, if the softening point of the filler exceeds 2000 ° C., the compatibility with the glass component is poor in the firing step and the filler component tends to separate.

In the present invention, in order to form a partition having a shape satisfying the above formulas (1) and (2), the main partition includes a glass paste containing a low-melting glass powder and an inorganic powder containing a filler and an organic component. An average particle diameter Df ₅₀ (μm) of the filler contained in the paste used for the uppermost layer of the partition wall provided through a step of applying on the substrate and a baking step, and an average particle size Dg ₅₀ (μm) of the low-melting glass powder Satisfying the following formula (3), the maximum particle diameter Dg _TOP (μm) of the low-melting glass powder is preferably 5 μm or less.
0.5 <Dg ₅₀ ≦ Df ₅₀ <3.0 (3)
Tend to average particle diameter Dg ₅₀ of the low-melting-point glass generates a glass projections on fine particles to aggregate partition wall surface is less than 0.5 [mu] m, aggregates bulkhead chipping is likely to occur starting at the impact. On the other hand, if the thickness exceeds 3.0 μm, a local bulge may be generated at the top of the partition wall, and partition wall chipping is likely to occur from the local bulge as a starting point due to impact. In addition, when the filler Df ₅₀ is less than 0.5 μm, the filler is likely to aggregate in the paste, and when the partition is formed, the filler aggregate is generated at the top of the partition, and the partition chip is likely to start from the filler aggregate. Become. On the other hand, if the thickness exceeds 3.0 μm, a local bulge may be generated at the top of the partition wall, and the partition wall chipping tends to occur from the local bulge due to impact.

In order to form a partition that satisfies the above formulas (1) and (2), Dg ₅₀ is preferably equal to or less than the average particle diameter Df ₅₀ (μm) of the filler. When Dg ₅₀ is larger than Df _50, RSm tends to increase, and partition wall breakage tends to occur. The _{Dg TOP} of the low-melting-point glass ([mu] m) is preferably not 5μm or less. When Dg _TOP is larger than 5 μm, a local bulge of about 5 μm may occur at the top of the partition wall, and partition wall chipping is likely to occur due to the local bulge as a starting point. Here, the average particle diameter of the low melting point glass and the filler is the median diameter, and when the volume cumulative frequency curve is measured with a microtrack particle size distribution measuring device with the total volume of the powder such as filler being 100%, It can be calculated by obtaining the particle diameter at the point where the frequency is 50%. Moreover, the maximum particle diameter means the maximum particle diameter in the fine particles observed by the Microtrac particle size distribution analyzer.

  It is preferable that the compounding quantity of the filler in a partition is 5-40 volume% in the inorganic powder of a glass paste, and 10-40 volume% is more preferable. When the blending amount of the filler exceeds 40% by volume, the partition walls are not sufficiently sintered in the firing step, and the surface roughness of the partition walls tends to increase. On the other hand, if the blending amount of the filler is less than 5% by volume, the chipping tends to deteriorate because the fracture toughness is lowered.

  80-200 micrometers is preferable and, as for the thickness of the whole partition, 100-150 micrometers is more preferable. When the thickness exceeds 200 μm, the driving voltage increases and the power consumption tends to increase. On the other hand, when the thickness is less than 80 μm, there is a tendency that the display quality is deteriorated, for example, the electric charge cannot be sufficiently accumulated during discharge and the lamp is not lit.

  In addition, when the partition wall is composed of the main partition wall and the auxiliary partition wall that intersects the main partition wall, both the main partition wall and the auxiliary partition wall shrink during the firing process, so that the height of the intersection between the main partition wall and the auxiliary partition wall becomes low. There is a problem that waviness is generated at the top of the partition wall. When the difference between the maximum height and the minimum height of the main partition wall from the center point of the intersection of the main partition wall and the auxiliary partition wall to the center point between the auxiliary partition walls in the direction of the main partition wall is swelled, the swell may be less than 6 μm. Preferably, it is less than 4 μm, more preferably less than 2 μm. If the crossing dents of the barrier ribs are 6 μm or more, the accumulated charge leaks to the adjacent cells during discharge, so that there is a tendency that the data voltage rises and non-lighting occurs and the display quality is lowered. Therefore, in order to solve the swell, the volume content of the filler with respect to the total inorganic powder in the glass paste used for the lower layer of the main partition wall and the auxiliary forehead wall is the filler content relative to the inorganic powder in the glass paste used for the upper layer of the main partition wall. The volume content is preferably larger than the volume content. More preferably, the filler used in the inorganic powder of the paste used for the lower layer of the main partition wall contains 15 to 40% by volume, and the paste used for the upper layer contains 5 to 30% by volume.

  The cross-sectional shape of the partition can be a trapezoid or a rectangle. The partition top width and auxiliary partition top width are preferably 20 to 100 μm, and more preferably 25 to 80 μm. If the top width of the partition wall is less than 20 μm, the mechanical strength is lowered, and the partition wall is likely to fall when sealed to the front plate, or the partition wall is easily chipped due to impact. On the other hand, when the thickness exceeds 100 μm, the discharge area of the panel tends to decrease, and the brightness of the PDP tends to decrease. In addition, about the bottom part width of a partition and an auxiliary partition, it is preferable that it is 45-150 micrometers for the same reason, and it is more preferable that it is 50-110 micrometers.

  80-200 micrometers is preferable and, as for the height of a partition, 100-150 micrometers is more preferable. When the thickness exceeds 200 μm, the driving voltage increases and the power consumption tends to increase. On the other hand, when the thickness is less than 80 μm, there is a tendency that the display quality is deteriorated, for example, the electric charge cannot be sufficiently accumulated during discharge and the lamp is not lit.

  The main partition wall height is preferably higher than the auxiliary partition wall height. In particular, the main partition wall height is more preferably 2 to 40 μm, and more preferably 4 to 20 μm, with respect to the auxiliary partition wall height. If the difference between the height of the main partition walls is less than 2 μm, the gas passage becomes narrow when the back plate and the front plate are sealed and then the gas in the cell is extracted and filled with the noble gas. Insufficient gas tends to remain or it becomes difficult to enclose a rare gas. On the other hand, if the thickness exceeds 40 μm, the role of the auxiliary partition (partitioning of cells adjacent in the panel vertical direction) becomes insufficient, and there is a concern that the charge accumulated in the cells may escape in the vertical direction of the panel.

  The photosensitive organic component of the photosensitive paste used in the method for producing the PDP back plate of the present invention contains a photosensitive component selected from at least one of a photosensitive monomer, a photosensitive oligomer, and a photosensitive polymer. It is preferable to add a photopolymerization initiator, a light absorber, a sensitizer, an organic solvent, a sensitizer, and a polymerization inhibitor as necessary.

  The photosensitive monomer is a compound containing a carbon-carbon unsaturated bond, and specific examples thereof include monofunctional and polyfunctional (meth) acrylates, vinyl compounds, allyl compounds, and the like. be able to. These can be used alone or in combination of two or more. Specific examples include dipentaerythritol hexaacrylate.

  As the photosensitive oligomer and photosensitive polymer, an oligomer or polymer obtained by polymerizing at least one of compounds having a carbon-carbon double bond can be used. In the polymerization, it can be copolymerized with other photosensitive monomers so that the content of these monomers is 10% by weight or more, more preferably 35% by weight or more. By copolymerizing an unsaturated acid such as an unsaturated carboxylic acid with a polymer or oligomer, the developability after exposure can be improved. 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 acid value (AV) of the polymer or oligomer having an acidic group such as a carboxyl group in the side chain thus obtained is preferably in the range of 50 to 180, more preferably in the range of 70 to 140. By adding a photoreactive group to the side chain or molecular end of the polymer or oligomer shown above, it can be used as a photosensitive polymer or photosensitive oligomer having photosensitivity. Preferred photoreactive groups are those having an ethylenically unsaturated group. Examples of the ethylenically unsaturated group include a vinyl group, an allyl group, an acrylic group, and a methacryl group.

  Specific examples of the photopolymerization initiator include benzophenone, methyl O-benzoylbenzoate, 4,4-bis (dimethylamino) benzophenone, 4,4-bis (diethylamino) benzophenone, 4,4-dichlorobenzophenone, 4- Examples include benzoyl-4-methylphenyl ketone, dibenzyl ketone, fluorenone, 2,3-diethoxyacetophenone, 2,2-dimethoxy-2-phenyl-2-phenylacetophenone, and the like. One or more of these can be used. The photopolymerization initiator is preferably added in the range of 0.05 to 10% by weight, more preferably 0.1 to 5% by weight, based on the photosensitive component. When the amount of the polymerization initiator is less than 0.05% by weight, the photosensitivity tends to decrease, and when the amount of the photopolymerization initiator is more than 10% by weight, the residual ratio of the exposed portion tends to be too small. .

  It is also effective to add a light absorber. By adding a compound having a high absorption effect of ultraviolet light or visible light, a high aspect ratio, high definition, and high resolution can be obtained. As the light absorber, an organic dye is preferably used. Specifically, an azo dye, an aminoketone dye, a xanthene dye, a quinoline dye, an anthraquinone dye, a benzophenone dye, a diphenylcyanoacrylate dye. Dyes, triazine dyes, p-aminobenzoic acid dyes, and the like can be used. Since organic dye does not remain in the insulating film after baking, it is preferable because the deterioration of the insulating film characteristics due to the light absorber can be reduced. Among these, azo dyes and benzophenone dyes are preferable, and specific examples thereof include Basic Blue 26. The addition amount of the organic dye is preferably 0.05 to 5% by weight, and more preferably 0.05 to 1% by weight. When the addition amount is less than 0.05% by weight, the effect of adding the light absorber tends to be reduced, and when the addition amount is more than 5% by weight, the insulating film characteristics after firing tend to be lowered.

  A sensitizer is added in order to improve sensitivity. Specific examples of the sensitizer include 2,4-diethylthioxanthone, isopropylthioxanthone, 2,3-bis (4-diethylaminobenzal) cyclopentanone, 2,6-bis (4-dimethylaminobenzal) cyclohexanone, and the like. Is mentioned. One or more of these can be used. When adding a sensitizer to a photosensitive paste, the addition amount is 0.05 to 10 weight% normally with respect to the photosensitive component, More preferably, it is 0.1 to 10 weight%. If the amount of the sensitizer is less than 0.05% by weight, the effect of improving the photosensitivity tends not to be exhibited. If the amount of the sensitizer is larger than 10% by weight, the residual ratio of the exposed portion tends to be small. is there.

  In addition, an antioxidant, a thixotropy imparting agent, and the like are appropriately added. The antioxidant is added to prevent the acrylic polymer from being oxidized. Specific examples include 1,6-hexanediol-bis [(3,5-di-t-butyl-4-hydroxyphenyl) propionate], and thixotropy-imparting agent includes N, N′-di (12-hydroxystearin). Acid) butylenediamine and the like.

  Examples of the organic solvent include methyl cellosolve, ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether acetate, butyl carbitol acetate, methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol, isopropyl alcohol, tetrahydrofuran, dimethyl sulfoxide. , Γ-butyllactone, N-methylpyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, bromobenzene, chlorobenzene, dibromobenzene, dichlorobenzene, bromobenzoic acid, chlorobenzoic acid, benzyl alcohol, and the like An organic solvent mixture containing one or more of them is used.

  When forming the barrier rib pattern, when forming the auxiliary barrier rib, the position and pitch of the auxiliary barrier rib are formed at the position where the pixel is divided when the plasma display is combined with the front plate. This is preferable from the viewpoint of light emission efficiency of the layer. Note that the partition wall width, the auxiliary partition wall width, and the partition wall height are each reduced by 10 to 40% by firing. Therefore, the dimensions of the partition wall and the auxiliary partition wall before firing may be determined in consideration of this ratio.

  The photosensitive paste is usually prepared by mixing the above-mentioned inorganic fine particles and organic components so as to have a predetermined composition, and then uniformly mixing and dispersing them with a three roller or kneader. Next, a photosensitive paste is applied, dried, exposed, developed, and the like.

  The partition / auxiliary partition pattern obtained by development is fired in a firing furnace. The firing atmosphere and temperature vary depending on the type of paste and substrate, but firing is performed in an atmosphere of air, nitrogen, hydrogen, or the like. The firing temperature is preferably 350 to 800 ° C. Moreover, when forming a partition directly on a glass substrate, it is preferable to perform baking by holding at a temperature of 450 to 620 ° C. for 10 to 60 minutes.

  Next, phosphor layers that emit light of each color of R (red), G (green), and B (blue) are formed between the barrier ribs formed in parallel with predetermined address electrodes. The phosphor layer is formed by applying a phosphor paste containing phosphor powder, an organic binder, and an organic solvent as main components between predetermined partitions, drying, and firing as necessary, so that the PDP back plate of the present invention Can be formed.

  Using this PDP back plate, after sealing with the front plate, a discharge circuit composed of helium, neon, xenon, etc. is sealed in the space formed between the front and back substrates, and a drive circuit is mounted. A plasma display can be produced. The front plate is a member in which a transparent electrode, a bus electrode, a dielectric, and a protective film (MgO) are formed on a substrate in a predetermined pattern.

  Next, examples of the present invention will be described. However, the present invention is not limited to such examples.

  A 42-inch size PDP back plate was produced and evaluated. A manufacturing method is demonstrated in order.

Dg ₅₀ , Df ₅₀ , and Dg _TOP were calculated by measuring a volume cumulative frequency curve of the powder using a microtrack particle size distribution measuring device (HRA (X-100) manufactured by Nikkiso Co., Ltd.).
[Example 1]
1. Production of Address Electrode As a glass substrate, PD-200 (manufactured by Asahi Glass Co., Ltd.) having a size of 590 × 964 × 2.8 mm and 42 inches was used. On this substrate, a stripe-shaped address electrode having a pitch of 240 μm, a line width of 100 μm, and a thickness after firing of 3 μm was formed by photolithography using a photosensitive silver paste having the following composition as a writing electrode.

Silver powder (cumulative median diameter 2.0 μm): 70% by weight
Glass powder (cumulative median diameter 2.2 μm): 2% by weight
(Composition of glass): Bismuth oxide: 69% by weight
Silicon oxide: 24% by weight
Aluminum oxide: 4% by weight
Boron oxide: 3% by weight
Acrylic acid, methyl methacrylate, styrene copolymer: 8% by weight
Trimethylolpropane triacrylate: 7% by weight
Benzophenone: 3% by weight
Butyl carbitol acrylate: 7% by weight
Benzyl alcohol: 3% by weight
2. Production of Dielectric Layer A dielectric paste having the following composition was applied to the substrate on which the address electrode was produced in 1, and then baked at 580 ° C. to form a dielectric layer having a thickness of 10 μm.

Low melting point glass powder (frit glass): 60% by weight
(Composition of glass): Bismuth oxide: 78% by weight
Silicon oxide: 14% by weight
Aluminum oxide: 3% by weight
Zinc oxide: 3% by weight
Boron oxide: 2% by weight
Titanium oxide powder (cumulative median diameter 0.2 μm): 10% by weight
Ethyl cellulose: 15% by weight
Terpineol: 15% by weight
3. Preparation of partition wall Low melting point glass The photosensitive paste for forming the partition wall had the following composition.

Low melting point glass powder (glass having a softening point of 500 ° C.): 30% by weight (Dg ₅₀ : 1.5 μm,
Dg _TOP : 4.5μm)
(Composition of low melting point glass):
Lithium oxide: 8% by weight
Silicon oxide: 27% by weight
Boron oxide: 30% by weight
Zinc oxide: 15% by weight
Aluminum oxide: 5% by weight
Calcium oxide: 15% by weight
Filler (high melting point glass having a softening point of 760 ° C.): 8% by weight (Df ₅₀ : 1.8 μm)
(Filler composition):
Silicon oxide: 38% by weight
Aluminum oxide: 35% by weight
Boron oxide: 10% by weight
Barium oxide: 6% by weight
Magnesium oxide: 5% by weight
Calcium oxide: 4% by weight
Zinc oxide: 2% by weight
Polymer: “Cyclomer” P (ACA250, manufactured by Daicel Chemical Industries, Ltd.): 15% by weight
Organic solvent (1): benzyl alcohol: 14% by weight
Organic solvent (2): Butyl carbitol acetate: 11% by weight
Monomer: Dipentaerythritol hexaacrylate: 18% by weight
Photopolymerization initiator: benzophenone: 2% by weight
Antioxidant: 1,6-hexanediol-bis [(3,5-di-tert-butyl-4-hydroxyphenyl) propionate]: 1% by weight
Organic dye: Basic Blue 26: 0.01% by weight
Thixotropic agent: N, N′-di (12-hydroxystearic acid) butylenediamine: 0.5% by weight
Surfactant: Polyoxyethylene cetyl ether: 0.49% by weight
The paste was applied to a thickness of 300 μm using a die coater and dried in a clean oven at 100 ° C. for 40 minutes to form a coating film. After that, a gap with a photomask (stripe, mask opening pitch: 300 μm, mask opening width: 50 μm) was provided at 150 μm, and the partition wall pattern portion was exposed.

The exposed substrate formed as described above was developed with a 0.5 wt% aqueous ethanolamine solution to form a stripe pattern. The substrate on which pattern formation was completed was baked at 590 ° C. for 15 minutes to form stripe-shaped partition walls.
4). Formation of phosphor layer As phosphor powders of red, blue, and green, red phosphor powders: (Y, Gd, Eu) BO ₃ (substances in which Y, Gd, Eu is activated on BO ₃ salt matrix), Blue phosphor powder: (Eu) BaMgAl ₁₀ O ₁₇ (a substance obtained by activating Eu in a BaMgAl ₁₀ O ₁₇ salt matrix), green phosphor powder: (Mn) Zn ₂ SiO ₄ (Mn in a Zn ₂ SiO ₄ salt matrix) Activated material). A phosphor paste having the following composition was used.

Phosphor powder: 40% by weight
Polymer: Ethylcellulose (made by Hercules), 20% by weight
Organic solvent (1): benzyl alcohol: 20% by weight
Organic solvent (2): butyl carbitol acetate: 20 weights Each color phosphor paste is applied to the substrate on which the partition walls are formed by using a screen printing method, dried, and baked (500 ° C., 30 minutes) to form side walls of the partition walls. And the fluorescent substance layer was formed in the bottom part, the back plate was produced, and the obtained back plate was evaluated. In Examples 2 to 5 and Comparative Examples 1 to 3, the partition wall forming paste has the same low melting point glass and filler components, and the particle size distribution shown in Table 1 is the filler volume content. A back plate was produced in the same manner as in Example 1 except that the blended material was used.
5). Production of front plate A front plate was produced by the following steps.
(I) As a glass substrate, PD-200 (manufactured by Asahi Glass Co., Ltd.) of 590 × 964 × 2.8 mm and 42 inch size was used. On the glass substrate, ITO was formed by sputtering, then resist was applied, and a transparent electrode having a thickness of 0.1 μm and a line width of 200 μm was formed by exposure / development processing and etching processing. Further, a bus electrode having a thickness of 5 μm after firing was formed by photolithography using a photosensitive silver paste made of black silver powder. Electrodes with a pitch of 375 μm and a line width of 100 μm were produced.
(Ii) A glass electrode obtained by kneading 70% by weight of low melting point glass powder containing 75% by weight of lead oxide, 20% by weight of ethyl cellulose, and 10% by weight of terpineol is screen-printed to obtain a bus electrode in the display portion. After coating with a thickness of 50 μm so as to be covered, baking was performed at 570 ° C. for 15 minutes to form a front dielectric.
(Iii) A front plate was prepared by forming a 0.5 μm-thick magnesium oxide layer as a protective film by electron beam evaporation on the substrate on which the dielectric was formed.
6). Preparation of PDP The obtained front glass substrate was sealed using the back glass substrate and the sealing glass, and Ne gas containing Xe 12% was sealed so as to have an internal gas pressure of 66500 Pa. Furthermore, a PDP was fabricated by mounting a drive circuit and evaluated.
[Example 6]
The same procedure as in Example 1 was performed except for the formation of the partition layer.
Preparation of barrier rib layer The lower barrier rib paste blended with the low melting point glass and filler shown in Table 1 was applied to a thickness of 250 μm using a die coater and dried in a clean oven at 100 ° C. for 40 minutes to form the barrier rib lower layer portion. A coating film was formed. Thereafter, the auxiliary partition wall pattern portion was exposed with a gap of 150 μm perpendicular to the address electrode and a photomask (stripe shape, mask opening pitch 700 μm, mask opening width: 45 μm). Furthermore, the upper layer partition paste blended with the low melting point glass and filler shown in Table 1 is applied to the thickness of 50 μm on the partition lower layer using a die coater, and has an upper and lower two-layer structure by the same operation as described above. A film was formed. Further, in parallel with the address electrodes, the partition wall pattern portion was exposed using a photomask (stripe, mask opening pitch 300 μm, mask opening width: 50 μm) in the same manner as described above.

  The exposed substrate formed as described above was developed with a 0.5 wt% aqueous ethanolamine solution to form a partition pattern in which main partition walls and auxiliary partition walls were orthogonal to each other. The substrate on which pattern formation was completed was baked at 590 ° C. for 15 minutes to form a grid-like partition wall having a difference in height between the main partition wall and the auxiliary partition wall of 15 μm.

The produced back plate and PDP were evaluated. In Examples 7 and 8, the partition wall forming paste is the same as the low melting point glass and the filler, and the particle size distribution shown in Table 1 is blended with each filler volume content. A back plate was prepared in the same manner as in Example 6 except for the above.
[Evaluation methods]
<Surface roughness>
Rz and RSm values, which are the surface roughness values of the top of the partition wall, are calculated from the average values obtained by measuring 10 times a measurement magnification of 50 times, a measurement pitch of 0.1 μm, and a partition wall top measurement length of 100 μm using a Keyence ultra-deep microscope vK-8500. did.
Rz was determined according to the definition described in JIS B0601 (2001) appendix 1, and RSm was determined according to the definition described in JIS B0601 (2001).
<Evaluation of partition wall defects>
The prepared back plate is bonded to a glass substrate and placed in a wooden box with a sponge spread with the glass substrate side down. After dropping this wooden box with an impact of 40G and giving an impact to the sample, it is confirmed by an image inspection device (Neptune 900, manufactured by V Technology Co., Ltd.) whether or not there is a partition wall defect on the back plate. The number of partition wall defects per sheet was counted. Evaluation was performed according to the following evaluation criteria. As for PDP, it is preferable that the partition gap at 40G is less than 7, more preferably less than 2. However, even if the product level is less than 15, it can withstand the transportation of the product. Can do.

× ・ ・ ・ Partition chipping = 15 or more △ ・ ・ ・ Partition chipping = 7 to less than 15 ○ ・ ・ ・ Partition chipping = 2 to less than 7 ◎ ・ ・ ・ Partition chipping = less than two
<PDP emission evaluation>
A voltage was applied to the produced PDP, and the light emission was evaluated. ◯ indicates that the display area emits light satisfactorily and has good, and X indicates that there is a large amount of adsorbed moisture on the partition walls of the back plate and there is unevenness in the display area when the PDP emits light, causing a problem as a display for display.
<Evaluation of waviness of partition wall top>
The undulation at the top of the partition wall of the manufactured back plate was evaluated. The measurement was performed with an ultra-deep microscope vK-8500 manufactured by Keyence, at a measurement magnification of 20 times and a measurement pitch of 0.2 μm. The measurement points are 10 points every 35 μm from the intersection of the main partition wall and the auxiliary partition wall to the center point between the auxiliary partition walls in the direction of the main partition wall. The height of the main partition wall is measured at that point, and the maximum between them The average value of the difference between the height and the minimum height was calculated at 15 points in the plane of the back plate, and the result was swelled. Evaluation was performed according to the following evaluation criteria. The PDP preferably has a swell of less than 4 μm, more preferably less than 2 μm. However, if the undulation is 6 μm or less as the product level of the PDP, there is no significant problem in display. If the swell is 6 μm or more, when a voltage is applied to the PDP, the accumulated charge leaks to the adjacent cells, so the data voltage rises and non-lighting occurs, degrading the display quality, causing problems with the display display. is there.

X ... Waviness = 6 .mu.m or more. .DELTA .... Waviness = 4 .mu.m or more and less than 6 .mu.m. O ... Waviness = 2 .mu.m or more and less than 4 .mu.m.

  The back plate obtained in Example 1 had few partition wall defects, and the results of PDP panel evaluation were also satisfactory. Moreover, the physical property evaluation was also a favorable result also about Examples 2-4 produced similarly to Example 1. FIG. About Comparative Examples 1-6, the problem generate | occur | produced in either a partition crack or PDP panel evaluation, and the performance of the target PDP was not obtained.

Claims (3)

A plasma display back plate having a glass substrate, a substantially striped address electrode provided on the glass substrate, a dielectric layer covering the address electrode, and a partition including at least a main partition parallel to the address electrode. And the ten-point average roughness Rz (μm) of the top surface of the main partition wall and the average length RSm (μm) of the contour curve element satisfy the following expressions (1) and (2): Back plate.
1.8 ≦ RSm ≦ 3.0 (1)
1.2 ≦ Rz / RSm ≦ 2.5 (2) Included in the paste used for the uppermost layer of the partition wall, wherein the main partition wall is provided through a step of applying a glass paste including a low melting point glass powder and an inorganic powder containing a filler and an organic component on the glass substrate and a step of baking. The average particle diameter Df ₅₀ (μm) of the filler to be obtained and the average particle diameter Dg ₅₀ (μm) of the low melting glass powder satisfy the following formula (3), and the maximum particle diameter Dg _TOP (μm) of the low melting glass powder is The method for producing a back plate for a plasma display according to claim 1, wherein the thickness is 5 μm or less.
0.5 <Dg ₅₀ ≦ Df ₅₀ <3.0 (3) The partition is composed of the main partition and an auxiliary partition that intersects with the main partition, the main partition has a two-layer structure, and the volume content of the filler relative to the total inorganic powder in the glass paste used for the lower layer of the main partition is The method for producing a back plate for a plasma display according to claim 2, wherein the volume content of the filler relative to the total inorganic powder in the glass paste used for the upper layer of the main partition is larger.