JP2011108468A - Plasma display panel, and method of manufacturing plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a PDP (plasma display panel) manufacturing method by which deterioration of a phosphor layer on a rear surface plate can be suppressed. <P>SOLUTION: A dielectric layer of a front surface plate is formed by (i) a process of supplying first dielectric material containing glass component, silica particles, and organic solvent on a substrate with an electrode formed thereon, drying and heat-treating it to form a first dielectric layer; and (ii) a process of supplying second dielectric material containing glass frit, organic solvent, and binder resin on the first dielectric layer, and drying and heat-treating it to form a second dielectric layer. The glass component of the first dielectric material used in the process (i) contains polysiloxane formed in an implementation process of a sol-gel method. In the heat treatment of the process (ii), the glass frit in the second dielectric material is molten. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a dielectric layer of a plasma display panel, and more particularly to a method for manufacturing a dielectric layer on the front plate side of a plasma display panel. The present invention also relates to a plasma display panel obtained from such a manufacturing method.

As a display device for displaying a high-definition television image on a large screen, there is an increasing expectation for a display device using a plasma display panel (hereinafter also referred to as PDP).

  In a PDP (for example, a three-electrode surface discharge type PDP), a front plate on the front side and a back plate on the back side are arranged opposite to each other as viewed from the viewer, and their peripheral portions are sealed with sealing members. It has a structure. A discharge gas such as neon and xenon is sealed in a discharge space formed between the front plate and the back plate. The front plate includes a display electrode pair formed of a scan electrode and a sustain electrode formed on one surface of the glass substrate, and a dielectric layer and a protective layer that cover these electrodes. The back plate includes a plurality of address electrodes formed in a stripe shape in a direction orthogonal to the display electrode pair on the glass substrate, a base dielectric layer covering these address electrodes, and a partition that partitions a discharge space for each address electrode And red (R), green (G), and blue (B) phosphor layers coated on the side surfaces of the barrier ribs and the underlying dielectric layer.

  The display electrode pair and the address electrode are orthogonal to each other, and the intersection thereof forms a discharge cell. These discharge cells are arranged in a matrix, and three discharge cells having red, green, and blue phosphor layers arranged in the direction of the display electrode pair serve as pixels for color display. In such a PDP, a predetermined voltage is sequentially applied between the scan electrode and the address electrode and between the scan electrode and the sustain electrode to generate gas discharge. A phosphor layer is excited by ultraviolet rays generated by such gas discharge to emit visible light, thereby realizing color image display.

  In recent years, discharge cells have become finer with higher definition of PDPs (for example, it is necessary to form rear-side barrier ribs at a pitch of about 100 μm with higher definition). When the size of the discharge cell is reduced by miniaturization, there is a problem that the light emission luminance is lowered and the power consumption is increased. This is due to a decrease in aperture ratio, a decrease in light emission time per pixel accompanying an increase in the number of pixels, a decrease in light emission efficiency, and the like. As a method of increasing the light emission luminance, there is a method of increasing the aperture ratio by narrowing the width of the partition wall of the back plate. However, the light emission luminance is still insufficient, and further improvement is necessary.

  As another method for increasing the light emission luminance, there is a method for reducing the reactive power at the time of discharge by lowering the dielectric constant of the dielectric layer in the front plate and increasing the light emission efficiency. When forming the dielectric layer on the front plate side, a glass material containing a glass powder of several μm, a binder resin, and a solvent is applied on the glass plate using a known method such as screen printing or die coating, followed by heat treatment. By doing so, a flat and highly transparent dielectric layer is formed. However, since the dielectric material melts the glass powder at a low temperature, it is necessary to add a material (generally Bi or the like) that lowers the melting point of the glass (see, for example, Patent Document 1). This low melting glass material has a low purity and a high relative dielectric constant of 10 or more. In addition, although it is possible to lower the dielectric constant by adding other substances (generally alkali metals, etc.), the PDP electrode uses a highly conductive metal such as silver as a main component. Therefore, diffusion and colloidalization of silver by ion migration are promoted, and a yellowing phenomenon occurs in the dielectric. This greatly affects the optical characteristics of the PDP.

  Therefore, in order to increase the light emission luminance by lowering the dielectric constant of the dielectric layer, it is necessary to develop a new low dielectric constant material that replaces the current glass paste and a method for forming the dielectric layer using the material. As a method of forming a high-purity oxide dielectric layer, a method of depositing a solid oxide on a substrate by sputtering under vacuum (sputtering vapor deposition method) or a method of decomposing and depositing a raw material by plasma (chemical vapor deposition). Law). Although these methods can form a high-purity and low-dielectric-constant dielectric layer, expensive vacuum equipment is required, and the deposition rate is as low as several 100 nm per minute. In addition, the required film thickness is generally required to be 10 μm or more in terms of withstand voltage, etc., and there is a problem that the number of facilities increases in order to form a dielectric layer while improving productivity. .

On the other hand, there is a sol-gel method as a method for forming a dielectric having a low dielectric constant while ensuring productivity. In this method, after a metal alkoxide in a solvent is hydrolyzed to obtain a silicon compound, a film containing silicon oxide as a main component is formed by subjecting it to heating and subjecting it to condensation polymerization. For example, when the silicon compound is silicon hydroxide (Si (OH) ₄ ), a —Si—O—Si— network is formed by the following condensation polymerization reaction, and solid SiO _{2 serving} as a dielectric layer is formed. Is:

nSi (OH) ₄ → nSiO ₂ + 2nH ₂ O
(N: integer greater than or equal to 1)

When the silicon compound is polysiloxane, the dielectric layer is formed by the following condensation polymerization reaction:

According to this method, the dielectric layer can be formed at a low temperature because the glass is not melted. In addition, since the dielectric layer can be formed using existing equipment for applying the dielectric material paste, it is possible to achieve both a low manufacturing cost and a short tact.

  In the formation of a dielectric layer using the sol-gel method, a crack is generated in the dielectric layer due to volume shrinkage during the condensation polymerization reaction, and a thick film (generally about several μm) is generally formed. Although it was difficult, by mixing silica particles, it is possible to increase the film thickness to several μm to several tens of μm, and a PDP using the same has also been proposed (for example, see Patent Document 2). However, in a PDP composed of a dielectric layer obtained by this method, a phenomenon that the phosphor layer of the back plate deteriorates may occur. This is because "an organic gas that can be generated by desorption of polysiloxane from the main chain, etc. (for example, a gasified alkyl group contained in polysiloxane)" or "a gas adsorbed in silica particles" Is considered to be caused by contact with the phosphor layer. When such “deterioration of the phosphor layer” occurs, there is a concern that the brightness of the PDP decreases and the image quality is impaired.

JP 2002-053342 A International Patent Publication (WO) 07/023658

  The present invention has been made in view of the above circumstances. That is, the subject of this invention is providing the PDP manufacturing method by which deterioration of the fluorescent substance layer of a backplate was suppressed.

In order to solve the above problems, the present invention provides:
A method of manufacturing a plasma display panel comprising a front plate having an electrode, a dielectric layer, and a protective layer formed on a substrate,
The formation of the dielectric layer on the front plate
(I) A first dielectric material comprising a glass component, silica particles and an organic solvent is provided on a substrate on which an electrode is formed, and is subjected to drying and heat treatment, thereby forming a first dielectric layer. And (ii) a second dielectric material comprising a glass frit, an organic solvent and a binder resin (organic binder resin) is provided on the first dielectric layer and subjected to drying and heat treatment, whereby a second Forming a dielectric layer,
The glass component of the first dielectric material used in the step (i) comprises polysiloxane (that is, a substance having a siloxane skeleton or a siloxane bond [—Si—O—]) formed in the course of performing the sol-gel method. Also provided is a manufacturing method characterized in that the glass frit in the second dielectric material is melted during the heat treatment in the step (ii).

  In the manufacturing method of the present invention, a two-layered dielectric layer composed of a first dielectric layer and a second dielectric layer is formed. In particular, the manufacturing method of the present invention is characterized in that the first dielectric layer is formed from the raw material obtained in the course of performing the sol-gel method, while the second dielectric layer is formed using the glass frit welding method.

In this specification, the “front plate” refers to a panel substrate on the surface side as viewed from the person viewing the image, and substantially refers to the panel substrate on the side where the phosphor layer and the partition wall are not present. (In other words, the “front plate” is the panel substrate disposed opposite to the “back plate” where the phosphor layers and the barrier ribs exist.)

  Further, in this specification, “formed in the course of performing the sol-gel method” means “formed using a precursor material such as a metal alkoxide and a substance such as a solvent along with the so-called sol-gel method”. Preferably, it means that, in the implementation of the sol-gel method, a precursor material such as a metal alkoxide is hydrolyzed using a substance containing an organic solvent or the like to form a sol. .

  In a preferred embodiment, when the heat treatment of step (i) is performed at about 550 ° C., the stress that can be generated in the first dielectric material is about 50 MPa or less, and the heat treatment of step (i) is about 550. The first dielectric material is used such that the degree of adhesion (or “adhesion” or “adhesion”) of the first dielectric layer obtained by carrying out at a temperature of about 10 mN or more is about 10 mN or more. Thereby, “crack generation” and “peeling phenomenon” can be effectively suppressed in the obtained dielectric layer.

  In another preferred embodiment, the heat treatment in step (i) is performed at a higher temperature than the heat treatment performed in step (ii). That is, the heat treatment for forming the first dielectric layer is performed at a temperature higher than the heat treatment temperature for forming the second dielectric layer. Thereby, degradation of a fluorescent substance layer can be suppressed more effectively in completed PDP.

  In the step (ii), it is preferable to use a second dielectric material that does not contain Bi (bismuth). This is because “yellowing” of the dielectric layer can be effectively prevented.

The present invention also provides a plasma display panel obtained through the manufacturing method described above. In such a plasma display panel, a front plate in which an electrode, a dielectric layer, and a protective layer are formed on a substrate is opposed to a back plate in which an electrode, a dielectric layer, a partition wall, and a phosphor layer are formed on the substrate. A plasma display panel comprising:
The dielectric layer of the front plate is composed of a first dielectric layer in contact with the substrate and a second dielectric layer formed on the first dielectric layer, and the first dielectric layer is formed The stress generated in the process is 50 MPa or less, and the adhesion to the substrate is 10 mN or more.

  Since the plasma display panel of the present invention is obtained through the manufacturing method described above, the first dielectric layer is obtained through the sol-gel method, whereas the second dielectric layer is glass frit welded. It has been obtained by law.

  In such a plasma display panel, the first dielectric layer is “because the stress generated in the formation process is 50 MPa or less and the adhesion to the substrate is 10 mN or more”. In addition, it may have a feature that “crack” and “peel” of the dielectric layer are effectively suppressed.

  In the manufacturing method of the present invention, the second dielectric layer is a dense layer due to the glass frit welding method / melting method. Therefore, after completion of the PDP, “gas resulting from residual alkyl groups that can be contained in the first dielectric layer” and “gas adsorbed in the silica particles of the first dielectric layer” are released into the panel. This can be prevented by the second dielectric layer. In other words, the phenomenon that “the emitted gas contacts the phosphor layer on the back plate and the phosphor layer deteriorates” can be effectively prevented, so that a plasma display panel in which luminance degradation is suppressed can be realized.

  Further, in the case where “the stress generated in the formation process of the first dielectric layer is 50 MPa or less and the adhesion of the first dielectric layer to the substrate is 10 mN or more”, the dielectric layer is It does not substantially contain physical defects such as cracks, and because the dielectric layer is effectively prevented from peeling off, the resulting PDP is derived from “cracking” and “dielectric layer peeling. The occurrence of sparks is effectively suppressed.

The perspective view which shows the structure of PDP typically Sectional drawing which shows the structure of a PDP front plate typically The perspective sectional view showing the process of the manufacturing method of the present invention typically Explanatory diagram for explaining "Stress calculation" (including arithmetic expressions) Chart for explaining "calculation of adhesion"

  The “plasma display panel manufacturing method” and “plasma display panel” of the present invention will be described in detail below. The PDP according to the present invention can be obtained based on a general PDP manufacturing method in principle. In other words, it can be said that it can be obtained based on a general PDP manufacturing method except for the dielectric layer forming step. Therefore, in the present invention, unless otherwise specified, raw materials / constituent materials of various constituent members may be those conventionally used in general PDP manufacturing methods. It should be noted that the various elements shown in the drawings are merely schematically shown for the purpose of understanding the present invention, and the dimensional ratio, appearance, and the like may be different from the actual ones.

[ Configuration of plasma display panel ]
First, the PDP finally obtained through the manufacturing method of the present invention will be briefly described. FIG. 1 is a cross-sectional perspective view showing a basic configuration of a PDP according to the present invention.

In the front plate (1) of the PDP (100), a display electrode (11) comprising a scanning electrode (12) and a sustaining electrode (13) on a smooth, transparent and insulating substrate (10) (for example, a glass substrate). Are formed, a dielectric layer (15) is formed so as to cover the display electrode (11), and a protective layer (16) (for example, a protective layer made of MgO) is formed on the dielectric layer (15). Layer) is formed. In particular, as shown in FIG. 2, the display electrode (11) has a plurality of electrode pairs (11) in which electrodes composed of transparent electrodes (12a, 13a) and bus electrodes (12b, 13b) are paired. It is composed by making. The transparent electrodes (12a, 13a) are transparent conductive films made of indium oxide (ITO) or tin oxide (SnO ₂ ), and preferably have a thickness of about 50 to 500 nm. On the other hand, the bus electrodes (12b, 13b) are blackish electrodes mainly composed of silver, and preferably have a thickness dimension of about 1 to 10 μm (more preferably a thickness dimension of 1 to 5 μm). And preferably has a width dimension of 10 to 200 μm (more preferably a width dimension of 50 to 100 μm). Incidentally, the material used for the bus electrode is not particularly limited, and a thin film laminated electrode such as Cr / Cu / Cr may be used instead of the silver component electrode.

  In the back plate (2) arranged to face the front plate (1), a plurality of address electrodes (21) are formed on an insulating substrate (20), and a dielectric layer ( 22) is formed. A partition wall (23) is provided at a position corresponding to the space between the address electrodes (21) on the dielectric layer (22), and between the adjacent partition walls (23) on the surface of the dielectric layer (22). , Red, green and blue phosphor layers (25) are respectively provided.

  The front plate (1) and the back plate (2) sandwich the partition wall (23) so that the display electrode (11) and the address electrode (21) are orthogonal to each other and the discharge space (30) is formed. Are arranged facing each other. In the discharge space (30), a rare gas such as helium, neon, argon, or xenon is sealed as a discharge gas (filling pressure is, for example, about 55 kPa to 80 kPa). In the PDP (100) configured as described above, the discharge space (30) partitioned by the partition wall (23) and intersecting the display electrode (11) and the address electrode (21) functions as a discharge cell (32). become.

[ General manufacturing method of PDP ]
Next, a typical manufacturing method of such a PDP (100) will be briefly described. The manufacture of the PDP (100) is divided into a front plate (1) forming step and a back plate (2) forming step. First, in the step of forming the front plate (1), the display electrode (11) is formed on the glass substrate (10) by forming a transparent electrode by, for example, sputtering or the like and forming a bus electrode by firing or the like. To do. Next, a dielectric material is applied on the glass substrate (10) so as to cover the display electrode (11) and heat-treated to form a dielectric layer (15). Next, a protective layer (16) is formed on the dielectric layer (15) by forming a film such as MgO by an electron beam evaporation (EB evaporation) method or the like to obtain a front plate (1).

  In the step of forming the back plate (2), an address electrode (21) is formed on the glass substrate (20) by, for example, a firing method, and a dielectric material is applied thereon to form a dielectric layer (22). Form. Next, barrier ribs (23) made of low-melting glass are formed in a predetermined pattern, and a phosphor material (25) is formed by applying a phosphor material between the barrier ribs (23) and firing. Next, a sealing member (not shown in FIG. 1) is formed by applying, for example, a low melting point frit glass material (that is, “sealing material used for panel sealing”) to the periphery of the substrate and firing. The back plate (2) is obtained.

  The obtained front plate (1) and rear plate (2) are aligned so as to face each other, and heated in a fixed state to soften the sealing member, whereby the front plate (1) and the rear plate. (2) is airtightly bonded, so-called panel sealing is performed. Subsequently, after performing so-called exhaust baking in which the gas in the discharge space (30) is exhausted while being heated, the PDP (100) is completed by enclosing the discharge gas in the discharge space (30).

[ Production method of the present invention ]
The method of the present invention relates to the formation of a dielectric layer provided on the front plate in such PDP manufacturing.

  An embodiment of the present invention will be described with reference to FIG. In carrying out the present invention, first, a “substrate on which an electrode is formed” is prepared, and the step (i) is performed.

  The “substrate on which the electrode is formed” used in the step (i) means “the substrate on which the electrode on the front plate side is formed”, and more specifically, as shown in FIG. Means “glass substrate (10) on which display electrode (11) is formed”. That is, a glass substrate (10) having a display electrode (11) composed of a scan electrode (12) and a sustain electrode (13) is prepared. The substrate (10) is preferably an insulating substrate made of soda lime glass, high strain point glass, or various ceramics, and the thickness is preferably about 1.0 mm to 3 mm. The scan electrode (12) and the sustain electrode (13) are formed with transparent electrodes (12a, 13a) made of ITO or the like having a thickness of about 50 to 500 nm, respectively, and transparent to lower the resistance value of the display electrode. On the electrode, a bus electrode (12b, 13b) containing silver and having a thickness of about 1 to 10 μm is formed (see FIG. 2). Specifically, after forming the transparent electrode by a thin film process or the like, the bus electrode is formed through a firing process or the like. In particular, when forming the bus electrode, first, a conductive paste mainly composed of silver is formed in a stripe shape by a screen printing method. In addition, the bus electrode is formed in a stripe shape by applying a photosensitive paste mainly composed of silver by a die coating method or a printing method, drying at 100 ° C. to 200 ° C., and then patterning by a photolithography method that exposes and develops. You may form in. Alternatively, a dispensing method or an ink jet method may be used. Finally, after subjecting to drying, a bus electrode can be obtained by subjecting to baking at 400 ° C. to 600 ° C.

  In the manufacturing method of the present invention, the first dielectric material is provided to the “substrate on which the electrode is formed” thus obtained, followed by drying and heat treatment to form the first dielectric layer.

  The first dielectric material is a paste material containing a glass component, silica particles, and an organic solvent (hereinafter, the first dielectric material is also referred to as “first dielectric material paste”).

  The glass component contained in the first dielectric material comprises a polysiloxane (that is, a siloxane skeleton [—Si—O—]), and is preferably a paste obtained from an organic solvent and a precursor material during the sol-gel process. Or sol-like fluid material. Particularly preferred polysiloxane is a polysiloxane having a siloxane skeleton and an alkyl group. This is because if the polysiloxane contains alkyl, “cracks” that may occur during the formation of the dielectric layer can be effectively suppressed. The siloxane skeleton may be linear, cyclic, or three-dimensional network. The alkyl group preferably has about 1 to 6 carbon atoms, and examples thereof include an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, or a hexyl group. Or two or more types may be included). Further, the alkyl group is not necessarily limited, and a functional group similar thereto, for example, an alkylene group (such as a methylene group, an ethylene group, a propylene group, or a butylene group) may be included.

  Such a glass component can be prepared, for example, by mixing a precursor material such as silicon alkoxide and an organic solvent and adding water, a catalyst, or the like. More specifically, silicon alkoxide (particularly preferably silicon alkoxide containing an alkyl group) is mixed with an organic solvent, and water and a catalyst are added in small portions evenly at room temperature or under heating conditions while stirring. The glass component can be prepared by hydrolysis or condensation polymerization.

The precursor material used for the preparation of the glass component is not particularly limited, and may be a completely inorganic precursor material that does not contain an alkyl group such as methyl silicate and ethyl silicate, but particularly preferably methyltrimethoxysilane, Methyltriethoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, octyltrimethoxysilane, octyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxy Silane, phenyltriethoxysilane, trimethoxysilane, triethoxysilane, triisopropoxysilane, fluorotrimethoxysilane, fluorotriethoxysilane, dimethyldimethoxysilane, dimethyl Ethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, dimethoxysilane, diethoxysilane, difluorodimethoxysilane, difluorodiethoxysilane, trifluoromethyltrimethoxysilane, trifluoromethyltriethoxysilane, other alkoxide-based organosilicon compounds ( Si (OR) ₄ ), for example, tetratertiary butoxysilane (t-Si (OC ₄ H ₉ ) ₄ ), tetrasecondary butoxysilane sec-Si (OC ₄ H ₉ ) ₄ or tetratertiary amyloxysilane Si [ It is a precursor material containing an alkyl group such as OC (CH ₃ ) ₂ C ₂ H ₅ ] ₄ and a similar functional group. These precursor materials are not limited to one type, and two or more types of precursor materials may be used in combination.

  The organic solvent contained in the first dielectric material includes, but is not limited to, alcohols including methanol, ethanol, 1-propanol, 2-propanol, hexanol, cyclohexanol, ethylene glycol, and propylene glycol. Glycols, methyl ethyl ketone, diethyl ketone, ketones including methyl isobutyl ketone, α-terpineol, β-terpineol, terpenes including γ-terpineol, ethylene glycol monoalkyl ethers, ethylene glycol dialkyl ethers, diethylene glycol monoalkyl ethers , Diethylene glycol dialkyl ethers, ethylene glycol monoalkyl ether acetates, ethylene glycol dialkyl ether acetates, polyethylene Lenglycol monoalkyl ether acetates, diethylene glycol dialkyl ether acetates, propylene glycol monoalkyl ethers, propylene glycol dialkyl ethers, propylene glycol monoalkyl ether acetates, propylene glycol dialkyl ether acetates, monoalkyl cellosolves are used alone In addition, a mixture of at least one kind or two or more kinds of solvents selected from these solvents can also be used. In addition, since it is desired that the organic solvent eventually vaporize, it preferably has a boiling point in the range of about 300 ° C. or lower (more preferably 200 ° C. or lower).

  In order to effectively prevent cracks in the first dielectric layer, the first dielectric material paste contains silica particles. The average particle size (average particle diameter) of the silica particles used is preferably 50 to 200 nm. When the particle size is 50 nm or more, stress relaxation can be achieved due to an increase in voids between particles in the first dielectric layer formed later, and the specific surface area decreases. Thus, since a uniform and sufficient amount of polysiloxane can be interposed on the particle surface, the generation of cracks can be more effectively suppressed. On the other hand, when the particle size is 200 nm or less, the transmittance of visible light having a wavelength of 400 to 800 nm can be increased, and desired optical characteristics can be obtained. The silica particles do not necessarily have a single size, and may include two or more sizes. When two or more kinds of particle sizes are included, the silica particle filling rate in the obtained dielectric layer can be increased, and cracks can be more effectively prevented. As used herein, “particle size” means substantially the maximum length of the particles in all directions, and “average particle size” means an electron micrograph of the particles. For example, 10 particle sizes are measured based on the above, and the number average is calculated.

  The silica particles used may be crystalline or amorphous (amorphous). Further, the silica particles to be used may be in the form of a dry powder, or may be in the form of a sol that is previously dispersed in water or an organic solvent. There is no restriction | limiting in particular about the surface state of a silica particle, porosity, etc., The commercially available silica particle can also be used as it is. The silica particles may be added before the preparation of the sol-like dielectric material or after the preparation thereof. In terms of “transmittance of the dielectric layer”, it is preferable that the silica particles are sufficiently dispersed in the first dielectric material paste.

  Since the amount of silica particles contained in the first dielectric material paste is preferably determined by the ratio to the siloxane skeleton remaining in the dielectric layer, the weight of the first dielectric layer to be finally formed is used as a basis. In this case, it is about 10 to 99% by weight, preferably about 50 to 90% by weight. The greater the amount of silica particles remaining in the final dielectric layer, the higher the stress relaxation capability, while the lower the adhesion to the glass substrate.

  In order to improve the applicability of the first dielectric material paste, a binder resin may be added to the dielectric material. There is no restriction | limiting in particular as binder resin to add. For example, polyethylene glycol, polyvinyl alcohol, polyvinyl butyral, methacrylic acid ester polymer, acrylic acid ester polymer, acrylic acid ester-methacrylic acid ester copolymer, α-methylstyrene polymer, butyl methacrylate resin or cellulose resin Further, two or more of these may be used in combination. Dielectric raw material paste exhibits a weight reduction in a high temperature range (about 200 to 400 ° C.) due to the vaporization of the organic solvent, but the addition of a binder resin alleviates the rate of weight reduction of the entire paste material. And the effect of reducing the stress concentration can be achieved (particularly, cracks in the dried film can be suppressed due to the stress relaxation effect during drying). Furthermore, the binder resin also has an effect of assisting the adhesive force between the silica particles in a higher temperature region.

  The 1st dielectric material paste prepared from the component mentioned above has a paste form as the name suggests. For example, the first dielectric material paste has a viscosity of about 1 mPa · s to 50 Pa · s (particularly about 10 mPa · s to 50 Pa · s) at room temperature (25 ° C.) and a shear rate of 1000 [1 / s]. It is preferable. When the viscosity is in such a range, wetting and spreading of the dielectric material in the coating region can be more effectively prevented.

  The ratio of the various components of the first dielectric material paste is not particularly limited as long as it is a general ratio used in obtaining a typical PDP dielectric layer (more specifically, the so-called “sol-gel method”). There is no particular problem as long as it is a ratio generally employed when forming a dielectric layer using the above. However, in addition, in order to bring out the effects of the present invention, the solid content concentration of the first dielectric material paste is preferably 5% by weight to 60% by weight, more preferably 15% by weight to 40%. % By weight. The “solid content concentration” here means the weight ratio of “glass component + silica particles” with respect to the total weight of the first dielectric material paste, or “glass component + silica particles + binder” with respect to the total weight of the dielectric material paste. It refers to the weight ratio of “resin”. In order to increase the thickness of the dielectric layer, the film thickness in the wet state must be increased. However, if the solid content concentration is less than 5% by weight, a large amount of paste is used, which increases the material cost. (Also, when the solid content concentration is less than 15% by weight, the coating generally tends to be impaired due to a decrease in paste viscosity). On the other hand, when the solid content concentration exceeds 60% by weight, the distance between the glass components (for example, polyalkylsiloxane oligomers) is reduced, and aggregation is likely to occur, which is not desirable (and the solid content concentration is 40% by weight). If it exceeds the range, the polymerization reaction rate of the polysiloxane increases, and it is generally difficult to ensure a practical pot life).

  In the step (i), the prepared first dielectric material paste is applied on the “substrate on which the electrode is formed”, and then subjected to drying and heat treatment to form the first dielectric layer (15a). It is formed (see FIG. 3B).

  For the application of the first dielectric material paste, for example, a slit coater method may be used. The “slit coater method” is a method in which a pasty raw material is applied to a predetermined surface by pumping and discharging a pasty raw material from a wide nozzle. Alternatively, for example, a dispensing method may be used. The dispensing method is a method in which a dielectric material paste is charged into a cylindrical container having a small-diameter nozzle, and the dielectric material paste is discharged by applying air pressure from an opening on the side opposite to the nozzle. Further, as another method, a spray method, a printing method, a photolithography method, or the like may be used.

  The applied first dielectric material paste is dried to reduce the organic solvent contained therein, and as a result, a first dielectric precursor layer is formed. That is, the organic solvent evaporates by drying and escapes from the first dielectric material paste. The first dielectric material paste is not necessarily limited to drying by heat application, and other means may be used as long as the organic solvent evaporates. For example, the applied first dielectric material paste It may be placed under reduced pressure or under vacuum.

  In the case of drying by applying heat, for example, the applied first dielectric material paste is about 50 to 200 ° C. (preferably 60 ° C. to 150 ° C.) under atmospheric pressure for 0.1 to 2 hours. It is preferable to attach a degree. In addition, when placed under reduced pressure or under vacuum, the organic solvent is evaporated by maintaining the reduced pressure or degree of vacuum below the saturated vapor pressure of the organic solvent. For example, it is preferable to apply under a reduced pressure of 7 to 0.1 Pa or under vacuum. If necessary, drying may be performed by combining "heat application" and "under reduced pressure or under vacuum".

  The first dielectric precursor layer formed by “drying” preferably has a thickness of about 10 to 30 μm. Accordingly, the thickness of the first dielectric layer obtained after the heat treatment in the step (iii) can be substantially about 10 μm to about 30 μm. When the thickness is 10 μm or more, the withstand voltage is easily secured, and when it is less than 10 μm, the effect of reducing the reactive power, which is the effect of the low dielectric constant, becomes small. On the other hand, when the thickness is 30 μm or less, it is possible to reduce reactive power during discharge due to a decrease in the dielectric constant of the dielectric layer, and when it exceeds 30 μm, it is necessary to increase the discharge power. In addition, the cost of the circuit related to the discharge is greatly required.

  In step (i), “drying” is followed by “heat treatment”. That is, the first dielectric precursor layer is subjected to a heat treatment to form a first dielectric layer from the first dielectric precursor layer. In this heat treatment, due to the heating of the first dielectric precursor layer, the condensation polymerization reaction proceeds in the first dielectric precursor layer, and the first dielectric layer is finally formed. In the case where the first dielectric precursor layer contains a binder resin, the binder resin burns and is removed from the first dielectric precursor layer. The heating temperature during the heat treatment in step (i) can be determined by the boiling point and the content of the organic solvent that can remain in the precursor layer, in addition to the amount of heat required for the condensation polymerization reaction. It is about -600 degreeC range (for example, 550 degreeC). In addition, the time required for the heating temperature is determined by comprehensively considering the amount of heat required for the condensation polymerization reaction, the boiling point and the content of the organic solvent that can remain in the precursor layer, and varies depending on the type of dielectric material. In general, it is about 0.5 to 2 hours. As a heat treatment means, a heating chamber such as a firing furnace may be used. In this case, the first dielectric precursor layer can be entirely heat-treated by providing a “substrate having a display electrode and a first dielectric precursor layer” in the heating chamber.

  Subsequent to step (i), step (ii) is performed. That is, the second dielectric material is provided on the first dielectric layer and subjected to drying and heat treatment to form the second dielectric layer (15b) (see FIG. 3C).

  The second dielectric material is a pasty material containing glass frit, an organic solvent, and a binder resin (hereinafter, the second dielectric material is also referred to as “second dielectric material paste”).

The glass frit contained in the second dielectric material paste is preferably a low melting glass frit. The “low melting point glass frit” is preferably a glass frit having a glass transition point of about 300 ° C. to 400 ° C. Therefore, the “low melting point” as used in the present specification substantially refers to a glass transition point of about 300 ° C. to 400 ° C. (Because it has such a glass transition point, The glass frit is melted and welded at a heating temperature of, for example, 500 ° C. to 580 ° C. during the heat treatment of (ii)). The glass frit contained in the second dielectric material paste is preferably one having an average particle size prepared by a wet jet mill or a ball mill. For example, the average particle size of the glass frit is about 0.2 to 10 μm. Preferably, it is about 0.5-3.0 micrometers. Specific examples of the low melting point glass frit include PbO—SiO ₂ —B ₂ O ₃ glass frit, PbO—P ₂ O ₅ —SnF ₂ glass frit, and PbF ₂ —SnF ₂ —SnO—P ₂ O ₅ glass. In addition to using frit, lead-free glass frit including B ₂ O ₃ —ZnO—SiO ₂ glass frit can also be used.

  Examples of the organic solvent contained in the second dielectric material paste include alcohols such as methanol, ethanol, propanol, isopropyl alcohol, butanol, and isobutyl alcohol; ketones such as methyl ethyl ketone and methyl isobutyl ketone (MIBK); α-terpineol, Terpenes containing β-terpineol and γ-terpineol; ethylene glycol monoalkyl ethers; ethylene glycol dialkyl ethers; diethylene glycol monoalkyl ethers; diethylene glycol dialkyl ethers; ethylene glycol monoalkyl ether acetates; Diethylene glycol monoalkyl ether acetates; diethylene glycol dialkyl ether Propylene glycol monoalkyl ethers; Propylene glycol dialkyl ethers; Propylene glycol monoalkyl ether acetates can be used alone or at least one or two or more solvents selected from these solvents Mixtures of these can also be used.

  As the binder resin contained in the second dielectric material paste, polyvinyl alcohol, polyvinyl butyral, methacrylic acid ester polymer, acrylic acid ester polymer, acrylic acid ester-methacrylic acid ester copolymer, α-methylstyrene polymer or Butyl methacrylate resin and the like can be used, and furthermore, two or more of these can be used in combination.

  If necessary, dioctyl phthalate, dibutyl phthalate, triphenyl phosphate or tributyl phosphate is added to the second dielectric material paste as a plasticizer, and glycerol monooleate or sorbitan sesquioleate as a dispersant. The coating property may be improved by adding homogenol (a product name of Kao Corporation) or phosphoric acid ester of an alkylallyl group.

  The various components described above may be subjected to kneading with, for example, a three roll, and thereby the second dielectric material paste can be suitably prepared. The ratio of various components of the second dielectric raw material paste is not particularly limited as long as it is a ratio at which a “second dielectric layer” can be finally obtained through drying and heat treatment described later. For example, when the second dielectric material paste is made of glass frit and vehicle (= organic solvent + binder resin), the glass frit is about 50 wt% to 65 wt%, and the vehicle component is 35 wt% to 50 wt%. It is preferable that it is about weight%. The content ratio of the organic solvent and the binder resin in the vehicle component is about 50 to 98% by weight of the organic solvent and about 2 to 50% by weight of the binder resin (based on the vehicle weight).

  The 2nd dielectric raw material paste prepared from the component mentioned above has a paste form as the name suggests. For example, the second dielectric material paste preferably has a viscosity of about 3 mPa · s to 50 Pa · s at room temperature (25 ° C.) and a shear rate of 1000 [1 / s]. When the viscosity is in such a range, wetting and spreading of the dielectric material in the coating region can be more effectively prevented.

  In the step (ii), the prepared second dielectric material paste is applied on the first dielectric layer. For the application of the second dielectric raw material paste, the slit coater method may be used or the dispensing method may be used similarly to the application of the first dielectric raw material paste. Further, the second dielectric material paste may be applied by screen printing by another method, or may be applied by using a spray method, a photolithography method, or the like. The thickness of the second dielectric material paste layer obtained by coating is preferably about 5 to 60 μm, more preferably about 10 to 20 μm.

  In step (ii), the second dielectric material paste layer is subjected to drying and heat treatment to form the second dielectric layer. In other words, after the second dielectric raw material paste layer is dried to obtain the second dielectric precursor layer, the second dielectric precursor layer is subjected to a heat treatment so that the second dielectric precursor layer A second dielectric layer is formed. In the step (ii), it is preferable that the heat treatment includes a baking treatment, and therefore the baking treatment is preferably performed after the drying treatment. In such heat treatment, at least a part of the glass frit contained in the second dielectric material paste layer is melted. Thereby, the second dielectric layer finally obtained includes a glass material obtained by welding and solidifying the glass frit, and can constitute a “dense layer”.

  In the drying treatment, the second dielectric material paste layer is preferably subjected to a drying temperature condition of 60 ° C. to 150 ° C. for 0.1 to 2 hours. On the other hand, in the firing treatment, it is preferable that the second dielectric precursor layer is subjected to a firing temperature condition of 300 ° C. to 600 ° C. (for example, about 500 ° C. to 550 ° C.) for 0.1 to 2 hours. As a means for such drying and heat treatment, a heating chamber such as a baking furnace may be used. In this case, the second dielectric material paste layer is entirely subjected to drying and heat treatment by providing “a substrate having a display electrode, a first dielectric layer and a second dielectric material paste layer” in the heating chamber. be able to.

  As described above, the second dielectric layer thus obtained has dense material characteristics because it is formed by welding and solidifying the glass frit contained in the raw material. In other words, the second dielectric layer has low gas permeability, and for example, the gas permeability at room temperature to 500 ° C. is preferably about 0% to 1%. The term “permeability” as used herein means the percentage of the gas that can pass through the second dielectric layer with respect to the gas provided from the outside of the second dielectric layer under the temperature condition of room temperature to 500 ° C. (Note that the permeability value can be obtained using, for example, mass fragmentography). Thus, since the second dielectric layer has a low gas permeability, in the finally obtained PDP, a gas that can exist or can be generated in the dielectric layer (for example, “can be included in the first dielectric layer”). "Gas caused by residual alkyl group", "Gas adsorbed in silica particles of first dielectric layer" and / or "Gas confined in pores of dielectric layer") into the panel As a result, it is possible to suppress “a phenomenon in which the emitted gas contacts the phosphor layer of the back plate and the phosphor deteriorates”.

  In addition to the thickness of the second dielectric layer, it is desirable that the average particle size of the glass frit be larger in order to eliminate the organic gas path. Further, since the second dielectric layer is formed of a low melting point glass frit, the dielectric constant is generally higher than that of the first dielectric layer. Therefore, if the thickness of the second dielectric layer is larger than that of the first dielectric layer, the merit of high efficiency, which is a low dielectric constant effect, may be impaired. Therefore, the thickness of the second dielectric layer is the first dielectric layer thickness. It can be said that it is desirable that the thickness be equal to or less than the layer thickness. In summary, the second dielectric layer preferably has a thickness not less than the average particle size of the glass frit and not more than the first dielectric layer thickness.

  After the second dielectric layer is formed, a protective layer (16) is formed as shown in FIG. That is, the protective layer (16) is formed so as to cover the second dielectric layer (15b) by performing a vacuum deposition method or an electron beam method (EB method). The material of the protective layer is not limited to magnesium oxide (MgO), and may be beryllium oxide (BeO), calcium oxide (CaO), strontium oxide (SrO), barium oxide (BaO), or the like. Alternatively, the protective layer can be formed using a thermal CVD method, a plasma CVD method, a sputtering method, or the like. The PDP front plate is completed through the above steps.

  Next, process conditions and raw material conditions that are particularly preferable for the production method of the present invention will be described below.

(Characteristics of the first dielectric material)
In order to effectively suppress the occurrence of sparks “derived from cracks” and “derived from dielectric layer peeling” in the obtained PDP, a first dielectric material having the following characteristics (A) and (B) is used: It is preferable to use it.

  First, as a characteristic (A), it is preferable to use a first dielectric material having a stress generated in the process of forming the first dielectric layer of 50 MPa or less. More specifically, the first dielectric material is used such that “the stress that can be generated in the first dielectric material when the heat treatment in step (i) is performed at 550 ° C. is 50 MPa or less”. preferable. Thereby, physical defects such as cracks that can occur in the first dielectric layer can be mainly suppressed.

  Here, “the stress generated in the first dielectric material when the heat treatment in the step (i) is performed at 550 ° C.” means “the“ substrate + first dielectric ”that may be generated when the first dielectric layer is formed. It is stress indirectly obtained from the “warping state of the body layer”, and in particular, it substantially refers to “stress excluding the contribution of the electrode on the substrate”. More specifically, the value of such stress is determined by applying a first dielectric material on a 0.5 mm soda glass substrate and drying (drying temperature: 60 ° C. to 150 ° C.), and increasing the temperature by about 30 ° C./min. “First dielectric material obtained in a temperature profile obtained by heating for about 30 minutes at about 550 ° C., maintaining at about 550 ° C. for about 20 minutes, and about about 5 hours at about 2 ° C./min. It is a value calculated from the following formula 1 from the shape of “layer + glass substrate”, the shape of the glass plate measured in advance, the thickness of the first dielectric layer, and the like (see also FIG. 4).

Formula 1

  In addition, when the stress generated in the formation process of the first dielectric layer is 50 MPa or more, cracks are likely to occur in the first dielectric in the cooling process after firing in the formation of the second dielectric layer. There is concern about the problem of sparks due to insufficient withstand voltage when used in panels. In this regard, a dielectric composed of a polysiloxane having a conventional siloxane bond (—Si—O—) and silica particles usually relieves stress because the silica particles have some degree of freedom in the film. The stress can be relieved even when heated to a high temperature during the formation of the second dielectric layer. However, in the present invention, since the second dielectric material contains glass frit, the stress relaxation effect of the silica particles may be weakened. That is, the silica particles contained in the first dielectric layer and the glass frit contained in the second dielectric layer are converted into the first dielectric layer and the second dielectric in the cooling process after firing in the formation of the second dielectric layer. There is a possibility that the phenomenon of fixing at the interface with the layer occurs and the degree of freedom of the silica particles is lowered. Therefore, it is desirable that the stress be a smaller value when formed only by the first dielectric layer, and it is preferably 50 MPa or less.

  Next, as the characteristic (B), it is preferable to use a first dielectric material having an “adhesion degree of the first dielectric layer to the substrate of 10 mN or more”. More specifically, it is preferable to use a first dielectric material that provides “adhesion of the first dielectric layer obtained by carrying out the heat treatment in step (i) at 550 ° C. to the substrate of 10 mN or more”. . Thereby, peeling of the first dielectric layer (that is, peeling of the dielectric layer) can be mainly suppressed.

Here, “the adhesion degree is 10 mN or more” substantially means that the adhesion value obtained by the scratch test is 10 mN or more. This scratch test is a test for examining the adhesion of the first dielectric layer by pressing a hard protrusion against the surface of a test piece (first dielectric layer formed on a glass substrate) and moving it sideways (scratching). is there. More specifically, in the scratch test according to the present invention, the indenter needle is pressed against a test piece (first dielectric layer formed on a glass substrate) at a constant load speed and scratch speed, and the first dielectric layer is pressed against the test piece. This is a test for determining the adhesion of the first dielectric layer from the load causing damage. As a testing machine used for the scratch test, for example, a thin film scratch testing machine (model CSR-02A) manufactured by RHESCA may be used. In this case, a numerical value (peeling load value) obtained under the following measurement conditions (Table 1) ) May be used as the degree of adhesion (see also FIG. 5).

(Heat treatment conditions for step (i))
In the obtained PDP, it is preferable that the heat treatment in step (i) is performed at a higher temperature than the heat treatment performed in step (ii) in order to more effectively suppress deterioration of the phosphor layer due to the released gas. That is, it is preferable that the heat treatment temperature of the first dielectric precursor layer is higher than the heat treatment temperature of the subsequent second dielectric precursor layer. As a result, in the PDP manufacturing process after the dielectric forming step, the heat treatment temperature in step (i) is the highest temperature condition, and gas that may adversely affect the phosphor layer is removed as much as possible when performing step (i). Can be kept. In other words, the gas discharge from the first dielectric material / first dielectric layer has temperature dependency (that is, the gas discharge can be promoted as the temperature becomes higher), and the process temperature of step (i) is one. Since it is the highest, the gas can be released as much as possible in this step, thereby suppressing the gas emission in the subsequent process and the completed PDP. For example, the heat treatment temperature of the first dielectric precursor layer is preferably about 5 to 20 ° C. higher than the heat treatment temperature of the second dielectric precursor layer.

(Component of second dielectric material)
In the obtained PDP, in order to effectively prevent the yellowing phenomenon of the dielectric layer, the second dielectric material used in step (ii) preferably does not contain Bi (bismuth). This will be described in detail. Conventional PDPs often use bismuth-based glass. However, when bismuth-based glass is used, "organic gas desorbed from the first dielectric layer" or "gas desorbed from the adsorption gas of silica particles" For example, the Bi component may be reduced during firing of the second dielectric precursor layer. When the Bi component is reduced, the second dielectric layer is colored yellow. From such a viewpoint, the second dielectric material is preferably a material that does not contain a Bi component.

[ PDP of the present invention ]
Next, the PDP obtained by the production method of the present invention (that is, the PDP of the present invention) will be described. In the PDP of the present invention, a front plate in which an electrode, a dielectric layer, and a protective layer are formed on a substrate, and a back plate in which an electrode, a dielectric layer, a partition wall, and a phosphor layer are formed on the substrate are opposed to each other. It is a plasma display panel arranged.

  In the PDP according to the present invention, due to the formation process of the dielectric layer on the front plate side, as shown in FIGS. 2 and 3, the dielectric layers are the first dielectric layer (15 a) and the second dielectric layer ( 15b). More specifically, the dielectric layer includes a first dielectric layer (15a) in contact with the substrate (10) and a second dielectric layer (15b) formed on the surface portion of the first dielectric layer. It is configured. In particular, the PDP of the present invention is characterized in that the second dielectric layer includes a material obtained by welding and solidifying glass frit.

  Although the alkyl group used from the viewpoint of preventing cracks may remain in the dielectric layer, the material of the second dielectric layer (15b) on the upper layer side is dense and has low gas permeability. Gases that can be present or generated in the body layer are prevented from being released into the panel. Therefore, in the PDP of the present invention, it can be said that “a phenomenon in which the released gas is adsorbed on the phosphor layer and the phosphor deteriorates” can be suppressed.

  The first dielectric layer in the PDP of the present invention preferably has a stress generated in the formation process of 50 MPa or less and an adhesion to the substrate of 10 mN or more. Therefore, the dielectric layer does not substantially contain physical defects such as cracks, and peeling of the dielectric layer is effectively prevented. That is, in the PDP of the present invention, it can be said that the occurrence of sparks “derived from cracks” and “derived from peeling of the dielectric layer” is effectively suppressed.

  The second dielectric layer in the PDP of the present invention preferably does not contain Bi (bismuth). Thereby, in the PDP of the present invention, the yellowing phenomenon of the dielectric layer due to the Bi component is effectively prevented.

  Other configurations and characteristics of the PDP of the present invention and the manufacturing method thereof are described in the above-mentioned “Plasma display panel configuration”, “General manufacturing method of PDP”, and “Manufacturing method of the present invention”. Omitted to avoid duplication. Further, since various conditions, specifications, effects, etc. of the dielectric layer on the front plate side have already been described in relation to the manufacturing method of the present invention, further description is omitted to avoid duplication.

  As mentioned above, although embodiment of this invention has been described, it has only illustrated the typical example of the application scope of this invention. Therefore, those skilled in the art will readily understand that the present invention is not limited thereto and various modifications can be made.

  For example, in the manufacturing method of the present invention described above, the dielectric layer of the front plate has a two-layer structure, but the dielectric layer of the back plate may have a similar two-layer structure. Even in this case, the effect of the second dielectric layer on the back plate is not substantially different from that on the front plate side.

  In general PDP manufacturing, an adhesive frit material is used when sealing a front plate and a back plate facing each other. At this time, the adhesive frit material and a part of the dielectric layer are covered. Yes. In this regard, the silica particles contained in the first dielectric layer and the adhesive frit material are not good in adhesiveness with each other, so that part of the front plate and the back plate may be peeled off, which may cause a slow leak. Therefore, the adhesive frit material and the covered portion may be completely covered with the second dielectric layer.

  In order to confirm the effect of the present invention, a PDP having a dielectric layer having a two-layer structure composed of a first dielectric layer and a second dielectric layer was fabricated and its performance was evaluated. Various specifications of the PDP and the conditions of the dielectric layer are as follows.

● [PDP specifications]
-Partition wall height: 0.15 mm
-Separation of partition walls: 0.15 mm
・ Distance between display electrodes: 0.66mm
-Discharge gas: Ne-Xe mixed gas (Xe content: 15% by volume)
・ Injection pressure of discharge gas: 60 kPa

● [Specification of two-layer structure dielectric layer]
(First dielectric layer)
First dielectric material component glass component: polyalkylsiloxane obtained by sol-gel method, more specifically, sol-like polyalkylsiloxane obtained by hydrolyzing ethyl silicate using ethanol silica particles: average particle 50 nm spherical amorphous silica particles Organic solvent: Mixed solvent of alcohols and cellosolves Binder resin

* Weight% ratio of various components (based on the total weight of the first dielectric material)
Glass component + silica particles: organic solvent: binder resin = 20: 78: 2

* Viscosity of the first dielectric material: 20 to 200 mPa · s (25 ° C.)

-Formation of the first dielectric layer The first dielectric material is applied onto a soda glass substrate by a die coating method, dried at 80 ° C for 20 minutes, and then raised at a rate of about 30 ° C / minute over about 30 minutes. The heat treatment was carried out by a profile maintained at a temperature of 550 ° C. for about 20 minutes and at a rate of about 2 ° C./min for about 5 hours.

  In forming the first dielectric layer, the ratio of polyalkylsiloxane and amorphous silica particles, the thickness of the first dielectric layer, and the like were changed to prepare the stress and adhesion as in Examples 1 to 4. (See Table 2).

  The stress was evaluated as follows so that the contribution of electrodes and the like could be ignored. First, a paste was applied on a 0.5 mm glass plate (Poisson's ratio 0.24, Young's modulus 75 GPa) and dried, and then at a rate of about 30 ° C./min in a far infrared heating batch furnace manufactured by NGK. The stress was calculated based on the above-mentioned formula 1 for the sample obtained by the profile of raising the temperature over 30 minutes, maintaining at 550 ° C. for about 20 minutes, and lowering the temperature over about 5 hours at a rate of about 2 ° C./minute ( For shape measurement, a three-dimensional shape measuring machine NH-3MA manufactured by Mitaka Kogyo was used).

  The degree of adhesion was evaluated by a scratch test. Specifically, a thin film scratch tester (model: CSR-02A, manufactured by RHESCA) is applied to a sample obtained by applying a dielectric material on a soda glass substrate, drying at 60 ° C. to 150 ° C., and heat-treating at 550 ° C. Measurement conditions: A peel load value (mN) was determined using a stage speed of 20 μm / s, a stage angle of 5 deg, an excitation level of 80 μm, a gain of 20, an indenter curvature radius of 5 μm, and a spring constant of 81.35 gf / mm.

Second dielectric material component glass frit: SiO ₂ —B ₂ O ₃ —ZnO—R ₂ O (R: Li ₂ O, Na ₂ O, K ₂ O) glass frit (average particle size: 2 μm)
Organic solvent ... Turpineol, butyl carbitol acetate Binder resin ... Ethylcellulose

* Weight% ratio of various components (based on the total weight of the second dielectric material)
Glass frit: organic solvent: binder resin = 60: 35: 5

* Second dielectric material viscosity: 20 Pa · s (25 ° C.)

-Formation of second dielectric layer A second dielectric material is applied on a soda glass substrate by screen printing, dried at 110 ° C for 20 minutes, and then about 30 minutes at a rate of about 30 ° C / minute. Firing was carried out with a profile in which the temperature was raised and maintained at 550 ° C. for about 20 minutes, and the temperature was lowered at a rate of about 2 ° C./minute for about 5 hours.

As a comparative example, the following dielectric layers were also formed.
Comparative examples 1, 2 and 4: formed only with the first dielectric (ie, without forming the second dielectric)
Comparative Example 3: Conditions in which stress generated in the process of forming the first dielectric layer is greater than 50 MPa Comparative Example 5: SiO ₂ —B ₂ O ₃ —ZnO—Bi ₂ O ₃ as the glass frit of the second dielectric -R ₂ O (R: Li ₂ O, Na ₂ O, K ₂ O) glass frit is used.

● [PDP characterization]
In order to evaluate the characteristics of the PDP, the following evaluation items were evaluated.

(Evaluation index)
・ Luminance evaluation: Lighted for 500 hours, and those with 10% or more luminance deterioration confirmed not (x) ・ Spark evaluation: When lighted, sparks originating from cracks or film peeling were not allowed (X). Sparks caused by foreign matter and electrode defects were ignored.
Color evaluation: The b * value when not lit was evaluated using a colorimeter (Minolta Co., Ltd .; CR-300).

The evaluation results are shown in Table 2.

(result)
Comparative Example 1 Comparative Example 1 is a condition in which the stress is relatively large and the second dielectric layer is not provided. Since the stress was considerably larger than 218.0 MPa and 50 MPa, cracks were generated and sparks were generated even under conditions where the second dielectric layer was not provided. Further, since the second dielectric layer was not provided, the luminance was deteriorated.
Comparative Example 2 Comparative Example 2 is a condition where the stress is 64.0 MPa, which is slightly larger than 50 MPa, and the second dielectric layer is not provided. Since the second dielectric layer was not provided, cracks were not generated and spark evaluation was possible. However, since the second dielectric layer was not provided, luminance degradation occurred.
Comparative Example 3 Comparative Example 3 is a condition having a stress as slightly as 64.0 MPa as in Comparative Example 2, but is different from Comparative Example 2 in having a second dielectric layer. Although the phosphor did not deteriorate due to the second dielectric layer, cracks occurred and sparks occurred due to the second dielectric layer.
Comparative Example 4 Comparative Example 4 is a condition in which the stress is relatively small at 14.8 MPa and the second dielectric layer is not provided. Partly from the decrease in the degree of adhesion, small cracks occurred and sparks occurred. Although the same minute crack was confirmed also in Example 4, since it had the 2nd dielectric material layer, it was able to prevent a spark. Further, in Comparative Example 4, since the second dielectric layer was not provided, luminance degradation occurred.
Comparative Example 5 : Comparative Example 5 is a condition where the stress is relatively small at 31.5 MPa and the second dielectric layer is included. For this reason, luminance deterioration and spark did not occur, but on the other hand, since the second dielectric layer contained Bi, intense coloring was observed, and the image quality was greatly impaired.
Comparative Example 6 : Comparative Example 6 is a condition in which the stress is very small, the degree of adhesion is relatively small as 7.8 mN, and the second dielectric layer is included. Since the degree of adhesion was as small as less than 10 mN, cracks occurred due to film peeling and insufficient degree of adhesion, and sparks were generated. On the other hand, since the second dielectric layer was included, no luminance degradation was confirmed.
Examples 1-4 : Examples 1-4 have a stress of 50 MPa or less / adhesion of 10.0 mN or more, have a second dielectric layer, and further do not contain Bi in the second dielectric layer. Sparks due to cracks and film peeling did not occur, luminance deterioration was not observed, and coloring was not observed.

  Referring to the above results, it will be understood that the present invention can provide a high-quality and high-efficiency PDP in which “brightness deterioration” and “crack generation” of the front plate-side dielectric layer are suppressed.

  Since the PDP obtained by the production method of the present invention is highly reliable in which luminance deterioration and prevention of dielectric layer cracks are achieved, it can be suitably used as a television for general homes and a commercial display. In addition, it can be suitably used for other display devices.

DESCRIPTION OF SYMBOLS 1 Front plate 2 Back plate 10 Front board side board 11 Front board side electrode (display electrode)
12 Scan electrode 12a Transparent electrode 12b Bus electrode 13 Sustain electrode 13a Transparent electrode 13b Bus electrode 14 Black stripe (light shielding layer)
DESCRIPTION OF SYMBOLS 15 Dielectric layer on the front plate side 15a First dielectric layer 15b Second dielectric layer 16 Protective layer 20 Substrate on the back plate side 21 Electrode on the back plate side (address electrode)
22 Dielectric layer on the back plate side 23 Partition 25 Phosphor layer 30 Discharge space 32 Discharge cell 100 PDP

Claims (4)

A method of manufacturing a plasma display panel comprising a front plate having an electrode, a dielectric layer, and a protective layer formed on a substrate,
The formation of the dielectric layer on the front plate
(I) A first dielectric material comprising a glass component, silica particles and an organic solvent is provided on a substrate on which an electrode is formed, and is subjected to drying and heat treatment, thereby forming a first dielectric layer. And (ii) a second dielectric material comprising glass frit, an organic solvent and a binder resin is provided on the first dielectric layer and subjected to drying and heat treatment, thereby forming a second dielectric layer Comprising the steps of:
The glass component of the first dielectric material used in the step (i) includes polysiloxane formed in the course of performing the sol-gel method, and the second dielectric material in the second dielectric material is subjected to the heat treatment in the step (ii). A manufacturing method characterized by melting glass frit.   The stress generated in the first dielectric material when the heat treatment in the step (i) is performed at 550 ° C. is 50 MPa or less, and the heat treatment obtained in the step (i) is performed at 550 ° C. 2. The manufacturing method according to claim 1, wherein the first dielectric material is used such that the degree of adhesion of the one dielectric layer to the substrate is 10 mN or more.   The manufacturing method according to claim 1 or 2, wherein the heat treatment in the step (i) is performed at a higher temperature than the heat treatment performed in the step (ii). A plasma display comprising a front plate having an electrode, a dielectric layer, and a protective layer formed on a substrate, and a back plate having an electrode, a dielectric layer, a partition, and a phosphor layer formed on the substrate. A panel,
The dielectric layer of the front plate is composed of a first dielectric layer in contact with the substrate and a second dielectric layer formed on the first dielectric layer, and the first dielectric layer is formed A plasma display panel characterized in that a stress that can be generated in the process is 50 MPa or less, and an adhesion to a substrate is 10 mN or more.