JP2013161690A - Plasma display panel and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve a PDP in which high reliability is secured and environmental issues are further taken into account.SOLUTION: In a plasma display panel of the present invention, a front plate including a display electrode and a dielectric layer, and a back plate are arranged to face each other, the display electrode comprises a transparent electrode formed on a substrate and a bus electrode formed on the transparent electrode, the bus electrode has a single layer structure and contains a glass component and a silver component, the amount of the glass component in the bus electrode is 0.2 wt.% or more and 7 wt.% or less, and a part of a metal oxide included in the transparent electrode and a part of a metal oxide included in the dielectric layer are same.

Description

  The present invention relates to a plasma display panel used for a display device and the like and a manufacturing method thereof.

  A plasma display panel (hereinafter referred to as a PDP) can realize a high definition and a large screen, and thus a 100-inch class television or the like has been commercialized. In recent years, PDP has been applied to high-definition televisions that have more than twice the number of scanning lines compared to conventional NTSC systems, and PDPs that do not contain lead components have been commercialized in consideration of environmental issues. .

  A PDP basically includes a front plate and a back plate. The front plate covers a display electrode composed of a glass substrate of sodium borosilicate glass by a float method, a striped transparent electrode and a bus electrode formed on one main surface of the glass substrate, and the display electrode. The dielectric layer functions as a capacitor, and a protective layer made of magnesium oxide (MgO) formed on the dielectric layer. On the other hand, the back plate is a glass substrate, stripe-shaped address electrodes formed on one main surface thereof, a base dielectric layer covering the address electrodes, a partition formed on the base dielectric layer, It is comprised with the fluorescent substance layer which light-emits each of red, green, and blue formed between the partition walls.

  The front plate and the back plate are hermetically sealed with their electrode forming surfaces facing each other, and Ne—Xe discharge gas is sealed at a pressure of 55 kPa to 80 kPa in a discharge space partitioned by a partition wall. PDP discharges by selectively applying a video signal voltage to the display electrodes, and the ultraviolet rays generated by the discharge excite each color phosphor layer to emit red, green, and blue light, thereby realizing color image display doing.

  Silver electrodes for ensuring conductivity are used for the bus electrodes of the display electrodes, and low-melting glass mainly composed of lead oxide is used for the dielectric layer. However, due to recent environmental concerns An example in which a lead component is not included as a dielectric layer is disclosed (for example, see Patent Document 1).

JP 2003-128430 A

  Conventionally, a bus electrode has a black electrode layer containing a black component such as a pigment to ensure blackness and contrast on the image display surface side, and a metal electrode containing a metal component to ensure a low resistance value as a display electrode. A two-layer structure with a layer is generally used. The black electrode layer is formed on the substrate side which is the image display side, and the metal electrode layer is laminated on the black electrode layer so as to be on the discharge space side.

  By the way, in order to meet the market demand for the recent price reduction of flat-screen televisions, rapid cost reduction is essential. In order to reduce the cost, studies have been made to make the conventional two-layer structure of bus electrodes, which is the mainstream, into a single layer structure.

  The present invention has been made in view of such problems, and an object thereof is to provide a PDP having high image display quality while ensuring high reliability at a low cost.

  In order to solve the above problems, the PDP of the present invention has a front electrode having a display electrode and a dielectric layer, and a back plate disposed opposite to each other, and the display electrode has a transparent electrode formed on the substrate, A bus electrode formed on the transparent electrode, the bus electrode having a single layer structure, having a glass component and a silver component, and the amount of the glass component in the bus electrode is 0.00 by weight. It is 2% or more and 7% or less, and a part of the metal oxide included in the transparent electrode and a part of the metal oxide included in the dielectric layer are the same.

  The PDP manufacturing method of the present invention is a method of manufacturing a PDP in which a display electrode, a front plate having a dielectric layer, and a back plate are opposed to each other, wherein the display electrode is formed on a transparent substrate. An electrode and a bus electrode formed on the transparent electrode, the bus electrode having a single-layer structure, having a glass component and a silver component, and the amount of the glass component in the bus electrode being a weight ratio 0.2% or more and 7% or less, a part of the metal oxide included in the transparent electrode and a part of the metal oxide included in the dielectric layer are the same, and the glass component of the dielectric layer The softening point T1 (° C.) and the temperature T (° C.) for firing the dielectric layer satisfy T−T1 ≦ 50 ° C.

  As described above, according to the present invention, it is possible to realize a PDP that ensures high reliability and further considers environmental problems.

The perspective view which shows the structure of PDP in embodiment of this invention Sectional drawing which shows the structure of the front plate of the PDP

  Hereinafter, a PDP according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment)
FIG. 1 is a perspective view showing the structure of a PDP according to an embodiment of the present invention. The basic structure of the PDP is the same as that of a general AC surface discharge type PDP. As shown in FIG. 1, the PDP 1 has a front plate 2 made of a front glass substrate 3 and a back plate 10 made of a back glass substrate 11 facing each other, and its outer peripheral portion is sealed with a glass frit or the like. The material is hermetically sealed. The discharge space 16 inside the sealed PDP 1 is filled with a discharge gas such as Ne and Xe at a pressure of 55 kPa to 80 kPa.

  On the front glass substrate 3 of the front plate 2, a pair of strip-like display electrodes 6 made up of scanning electrodes 4 and sustain electrodes 5 and black stripes (light-shielding layers) 7 are arranged in a plurality of rows in parallel with each other. A dielectric layer 8 serving as a capacitor is formed on the front glass substrate 3 so as to cover the display electrode 6 and the light shielding layer 7, and a protective layer 9 made of magnesium oxide (MgO) is formed on the surface. Has been.

  On the back glass substrate 11 of the back plate 10, a plurality of strip-like address electrodes 12 are arranged in parallel to each other in a direction orthogonal to the scanning electrodes 4 and the sustain electrodes 5 of the front plate 2. Layer 13 is covering. Further, a partition wall 14 having a predetermined height is formed on the base dielectric layer 13 between the address electrodes 12 to divide the discharge space 16. For each address electrode 12, a phosphor layer 15 that emits red, blue, and green light by ultraviolet rays is sequentially applied to the grooves between the barrier ribs 14 and formed. A discharge cell is formed at a position where the scan electrode 4 and the sustain electrode 5 intersect with the address electrode 12, and the discharge cell having red, blue and green phosphor layers 15 arranged in the direction of the display electrode 6 is used for color display. Become a pixel.

FIG. 2 is a cross-sectional view of front plate 2 showing the configuration of dielectric layer 8 of the PDP in the embodiment of the present invention. 2 is shown upside down from FIG. As shown in FIG. 2, on the front glass substrate 3 manufactured by the float process etc., the display electrode 6 and the black stripe 7 which consist of the scanning electrode 4 and the sustain electrode 5 are pattern-formed. Scan electrode 4 and sustain electrode 5 are made of transparent electrodes 4a and 5a made of indium tin oxide (ITO) or tin oxide (SnO ₂ ), respectively, and metal bus electrodes 4b and 5b formed on transparent electrodes 4a and 5a. It is comprised by. The metal bus electrodes 4b and 5b are used for the purpose of imparting conductivity in the longitudinal direction of the transparent electrodes 4a and 5a, and are formed of a conductive material whose main component is a silver (Ag) material.

  The dielectric layer 8 is formed so as to cover these transparent electrodes 4a and 5a, the metal bus electrodes 4b and 5b and the black stripe 7 formed on the front glass substrate 3, and a protective layer 9 is further formed on the dielectric layer 8. Forming.

  Next, a method for manufacturing a PDP will be described. First, the scan electrode 4, the sustain electrode 5, and the light shielding layer 7 are formed on the front glass substrate 3. The transparent electrodes 4a and 5a and the metal bus electrodes 4b and 5b are formed by patterning using a photolithography method or the like. The transparent electrodes 4a and 5a are formed using a thin film process or the like, and the metal bus electrodes 4b and 5b are solidified by baking a paste containing a silver (Ag) material at a desired temperature. Similarly, the light shielding layer 7 is also formed by screen printing a paste containing a black pigment or by forming a black pigment on the entire surface of the glass substrate and then patterning and baking using a photolithography method.

  Next, a dielectric paste is applied on the front glass substrate 3 by a die coating method or the like so as to cover the scan electrode 4, the sustain electrode 5, and the light shielding layer 7, thereby forming a dielectric paste layer (dielectric material layer). After the dielectric paste is applied, the surface of the applied dielectric paste is leveled by leaving it to stand for a predetermined time, so that a flat surface is obtained. Thereafter, the dielectric paste layer is baked and solidified to form the dielectric layer 8 that covers the scan electrode 4, the sustain electrode 5, and the light shielding layer 7. The dielectric paste is a paint containing a dielectric material such as glass powder, a binder and a solvent. Next, a protective layer 9 made of magnesium oxide (MgO) is formed on the dielectric layer 8 by a vacuum deposition method. Through the above steps, predetermined components (scanning electrode 4, sustaining electrode 5, light shielding layer 7, dielectric layer 8, and protective layer 9) are formed on front glass substrate 3, and front plate 2 is completed.

  On the other hand, the back plate 10 is formed as follows. First, the structure for the address electrode 12 is formed by a method of screen printing a paste containing silver (Ag) material on the rear glass substrate 11 or a method of patterning using a photolithography method after forming a metal film on the entire surface. An address electrode 12 is formed by forming a material layer to be an object and firing it at a desired temperature. Next, a dielectric paste is applied on the rear glass substrate 11 on which the address electrodes 12 are formed by a die coating method so as to cover the address electrodes 12 to form a dielectric paste layer. Thereafter, the base dielectric layer 13 is formed by firing the dielectric paste layer. The dielectric paste is a paint containing a dielectric material such as glass powder, a binder and a solvent.

  Next, a partition wall forming paste including a partition wall material is applied on the base dielectric layer 13 and patterned into a predetermined shape to form a partition wall material layer and then fired to form the partition walls 14. Here, as a method of patterning the partition wall paste applied on the base dielectric layer 13, a photolithography method or a sand blast method can be used. Next, the phosphor layer 15 is formed by applying a phosphor paste containing a phosphor material on the base dielectric layer 13 between the adjacent barrier ribs 14 and on the side surfaces of the barrier ribs 14 and baking it. Through the above steps, the back plate 10 having predetermined components on the back glass substrate 11 is completed.

  In this way, the front plate 2 and the back plate 10 having predetermined constituent members are arranged to face each other so that the scanning electrodes 4 and the address electrodes 12 are orthogonal to each other, and the periphery thereof is sealed with a glass frit, so that a discharge space is obtained. 16 is filled with a discharge gas containing Ne, Xe or the like, thereby completing the PDP 1.

  Here, in the present embodiment, the display electrode 6 includes transparent electrodes 4a and 5a formed on the front glass substrate 3, and metal bus electrodes 4b and 5b formed on the transparent electrodes 4a and 5a. The electrodes 4b and 5b have a glass component and a silver component, and the amount of the glass component of the metal bus electrode is 0.2% or more and 7% or less by weight. Here, the softening point of the glass component of the metal bus electrodes 4b and 5b is preferably 500 ° C. or lower, and the softening point of the glass component of the dielectric layer 8 is preferably 550 ° C. or higher.

  The reason for making this embodiment as described above will be described in detail while comparing with the problems of the conventional PDP. Conventionally, a bus electrode has a black electrode layer containing a black component such as a pigment to ensure blackness and contrast on the image display surface side, and a metal electrode containing a metal component to ensure a low resistance value as a display electrode. A two-layer structure with a layer is generally used. The black electrode layer is formed on the substrate side which is the image display side, and the metal electrode layer is laminated on the black electrode layer so as to be on the discharge space side.

  Since the conventional metal electrode layer is a layer specialized for lowering resistance, silver (Ag) having a low resistance value is generally used as a metal component. And in order to maintain the shape as an electrode layer, a glass component is included in addition to a metal component. In this electrode layer firing step, firing is performed at about 500 ° C. to 600 ° C., but since the melting point of the Ag component is about 962 ° C., the melting of the Ag components does not proceed. However, by allowing a glass component having a low softening point in the gap between Ag components (for example, a softening point of about 450 ° C. to 500 ° C.), the glass component is sufficiently dissolved even at the firing temperature, and the Ag component diffuses into the glass, The contact / adhesion between Ag components was promoted to realize a decrease in resistance of the electrode layer.

  The black electrode layer not only ensures blackness and contrast during image display, but also has the role of maintaining adhesion or electrical continuity between the transparent electrode layer and the metal electrode layer.

  However, in the panel that eliminates the black electrode layer and reduces the cost of the PDP as in this embodiment, the Ag component in the metal electrode layer or a compound mainly composed of Ag erodes the transparent electrode layer. It has been found that a problem arises in that the contact resistance significantly increases at the interface between the transparent electrode layer and the metal electrode layer because it chemically changes to a component having no conductivity.

  Furthermore, when a metal bus electrode is formed in one layer, securing a low resistance value as an electrode and adhesion with a transparent electrode layer or a glass substrate on the lower layer side of the bus electrode become problems.

  As in the prior art, the layer that lowers the resistance on the dielectric side includes glass having a low softening point, so that Ag having a melting point of about 962 ° C. can be necked even at a firing temperature of about 600 ° C. The effect of lowering and the role of the adhesive to the substrate was achieved by including the glass with a low glass softening point in the black electrode layer. And the black electrode layer was able to reduce the erosion of the transparent electrode by reducing silver and to achieve both low resistance and suppression of increase in contact resistance with the transparent electrode. As a result, a large amount of silver contained due to low resistance comes into contact with the transparent electrode, which increases the erosion of the transparent electrode and makes it difficult to achieve both.

  Therefore, in the present embodiment, the amount of glass components of the metal bus electrodes 4b and 5b is 0.2% to 7% by weight ratio, thereby preventing erosion or fusion of the Ag component to the transparent electrode, and Low resistance as an electrode is realized.

  When the glass component is larger than 7%, the diffusion of the Ag component increases, and erosion of the transparent electrode occurs. On the other hand, if it is less than 0.2%, the adhesion of the bus electrode layer to the transparent electrode or the glass substrate cannot be secured, and film peeling occurs.

  Thereby, it is possible to achieve both low resistance and suppression of resistance increase of the transparent conductive film with one material, the electrode formation process can be reduced to half of the conventional one, and cost reduction of the PDP can be realized.

  Further, in the prior art, a manufacturing method is known in which a dielectric glass having a softening point of 500 ° C. or lower is used as the glass component of the dielectric layer and sintered at a high temperature around 600 ° C. However, in this case, the dielectric having a low softening point erodes or fuses the transparent conductive film, resulting in a problem of increasing the resistance. It has been confirmed that this phenomenon is reduced by making the softening point of the glass component contained in the bus electrode larger than 500 ° C. However, in this case, the resistance value of the bus electrode is increased.

  Therefore, in the present embodiment, in order to suppress the phenomenon that the dielectric layer erodes the transparent electrode, the glass component softening point T1 (° C.) of the dielectric layer 8 and the firing temperature T (° C.) at which the dielectric layer 8 is fired. Is such that T−T1 ≦ 50 ° C. This suppresses excessive activation of the dielectric paste component and prevents erosion of the transparent electrode by the dielectric. In this embodiment, this effect is confirmed by setting T1 = 550 ° C. or higher and T = 600 ° C.

  Further, in the present embodiment, this phenomenon is suppressed by including the metal oxide component of the transparent electrodes 4 a and 5 a in the dielectric layer 8.

  As a result, the softening point of at least one glass component contained in the metal bus electrodes 4b and 5b can be set to 500 ° C. or lower, the firing effect of the bus electrode is promoted, and the resistance value can be kept low.

  As described above, according to the PDP in the embodiment of the present invention, a PDP having high strength and high reliability can be realized as a dielectric layer.

  As described above, the PDP of the present invention realizes a PDP having consideration for the environment and high reliability, and is useful for a display device having a large screen.

1 PDP
2 Front plate 3 Front glass substrate 4 Scan electrode 4a, 5a Transparent electrode 4b, 5b Metal bus electrode 5 Sustain electrode 6 Display electrode 7 Black stripe (light shielding layer)
8 Dielectric layer 9 Protective layer 10 Back plate 11 Rear glass substrate 12 Address electrode 13 Base dielectric layer 14 Partition 15 Phosphor layer 16 Discharge space

Claims (2)

A front plate having a display electrode and a dielectric layer, and a back plate are arranged to face each other,
The display electrode is composed of a transparent electrode formed on a substrate and a bus electrode formed on the transparent electrode,
The bus electrode has a single layer structure and has a glass component and a silver component, and the amount of the glass component in the bus electrode is 0.2% to 7% by weight,
The plasma display panel, wherein a part of the metal oxide included in the transparent electrode and a part of the metal oxide included in the dielectric layer are the same. A method of manufacturing a plasma display panel in which a front plate having a display electrode and a dielectric layer and a back plate are arranged to face each other,
The display electrode is composed of a transparent electrode formed on a substrate and a bus electrode formed on the transparent electrode,
The bus electrode has a single layer structure and has a glass component and a silver component, and the amount of the glass component in the bus electrode is 0.2% to 7% by weight,
A part of the metal oxide included in the transparent electrode and a part of the metal oxide included in the dielectric layer are the same,
A method for manufacturing a plasma display panel, wherein a softening point T1 (° C.) of a glass component of the dielectric layer and a temperature T (° C.) for firing the dielectric layer 8 satisfy T−T1 ≦ 50 ° C.

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