KR100444521B1 - Back Plate of Plasma Display Panel and Method of Fabricating the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lower plate of a plasma display panel capable of improving the formability of partition walls and a method of manufacturing the same.

The lower plate of the plasma display panel according to the present invention is a partition wall formed by molding a green sheet bonded on a substrate, an address electrode printed on the green sheet, and a paste layer formed on the green sheet to cover the address electrode. It is provided. The paste layer is mixed with a second compound including _{ZnO, B 2 O 3, MgO} , SiO 2, and a first compound containing _{CuO, ZnO, B 2 O 3} , MgO, SiO 2, CuO, TiO 2, wherein The first compound and the second compound are mixed in a mixing ratio of 1: 1 to 2: 1.

According to this invention, the moldability of a partition can be improved.

Description

Back plate of plasma display panel and method of fabricating the same

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel, and more particularly, to a lower plate of a plasma display panel capable of improving the formability of partition walls and a method of manufacturing the same.

Plasma Display Panels (hereinafter referred to as "PDPs") display an image including characters or graphics by emitting phosphors by ultraviolet rays of 147 nm generated upon discharge of He + Xe or Ne + Xe gas. Such a PDP is not only thin and easy to enlarge, but also greatly improved in quality due to recent technology development.

Referring to FIG. 1, there is shown an AC drive type PDP having a lower glass substrate 14 on which an address electrode 2 is mounted and an upper glass substrate 16 on which a pair of sustain electrodes 4 are mounted. On the lower glass substrate 14 on which the address electrode 2 is mounted, a partition wall 8 for dividing the dielectric thick film 18 and the discharge cells is formed. The phosphor 6 is coated on the surfaces of the dielectric thick film 18 and the partition wall 8. The phosphor 6 emits light by ultraviolet rays generated at the time of plasma discharge so that visible light is generated. The dielectric layer 12 and the passivation layer 10 are sequentially formed on the upper glass substrate 16 on which the sustain electrode pairs 4 are mounted. The dielectric layer 12 accumulates wall charges during plasma discharge, and the protective layer 10 protects the pair of sustain electrodes 4 and the dielectric layer 12 from sputtering of gas ions during plasma discharge and improves the emission efficiency of secondary electrons. Height plays a role. The discharge cells of the PDP are filled with a mixed gas of He + Xe or Ne + Xe.

The partition 8 serves to prevent electrical and optical crosstalk between discharge cells. Therefore, the partition wall 8 is the most important factor for display quality and luminous efficiency, and as the panel is enlarged and fixed, various studies on the partition wall have been made. As the barrier rib manufacturing method, a screen printing method, a sand blasting method, an additive, a photosensitive paste method, and a low temperature cofired ceramic on metal (LTCCM) method are applied.

Among them, the screen printing method has a simple process and low manufacturing cost, but there is a problem of repeating the screen and the glass substrate 14 in each printing, printing and drying the glass paste several times. In addition, when the position of the screen and the glass substrate is shifted, the partition wall is deformed, so that the shape accuracy of the partition wall is lowered.

The sand blasting method has a merit of forming a partition on a large-area substrate, but a large amount of glass paste removed by the abrasive (sand particles) has a disadvantage of wasting material and manufacturing cost. In addition, the glass substrate 14 is impacted by the abrasive, so that the glass substrate 14 is cracked or damaged.

The addition method has an advantage of forming barrier ribs 8 on a large-area substrate, but it is difficult to separate photoresist and glass paste, leaving a residue or collapsing barrier ribs when forming barrier ribs.

The LTCCM method has a low temperature process and a simple process compared with other barrier rib manufacturing methods.

Figure 2a to 2h shows step by step manufacturing method using the LTCCM method. First, the green sheet 30 as shown in Figure 2a is produced. The green sheet 30 is manufactured by drying a slurry in which a glass powder, an organic solution, a plasticizer, a binder, an additive, and the like are mixed in a predetermined ratio on a polyester film, and forming a sheet in a doctor blading, followed by drying. . As a material of the substrate 32 to which the green sheet 30 is bonded, a metal, for example, titanium (Titanum) is usually used. Titanium may be manufactured to have a thickness thinner than that of other glass and ceramic materials because of its greater strength and heat resistance than glass or ceramic substrates, and may reduce thermal and mechanical deformation of the substrate 32.

In order to bond the substrate 32 and the green sheet 30, as shown in FIG. 2B, an inorganic material for glaze is sprayed onto the substrate 32 and then fired at a temperature of 500 to 550 ° C. to glaze. Form layer 34. Subsequently, an organic substance for glue is sprayed on the glaze layer 34 and dried to form a glue layer 36. The glue layer 36 serves as a bonding agent, and the substrate 32 and the green sheet 30 are bonded by a lamination process as shown in FIG. 2C. The lamination process is a process of adhering the substrate 32 and the green sheet 30 while applying a uniform pressure and temperature.

Subsequently, the address electrode 2 is printed on the green sheet 30 as shown in FIG. 2D and then dried.

On the substrate 32 on which the address electrode 2 is formed, as shown in FIG. 2E, the dielectric slurry is completely printed and then dried to form the electrode protective layer 37. Subsequently, an organic binder used as a binder for increasing the fluidity of the green sheet 30 bonded on the substrate 32, for example, poly-vinyl-butiral (hereinafter referred to as "PVB") The temperature is heated to the softening point of).

In the state where the flowability of the green sheet 30 is increased, as shown in FIG. 2F, the mold 38 having the groove 38a having the opposite shape to the partition wall is aligned on the substrate 32.

The mold 38 is pressed onto the substrate 32 at a pressure of about 150 kgf / cm ² or more as shown in FIG. 2G. When the mold 38 is pressed, the green sheet 30 and the electrode protective layer 37 are moved into the groove 38a of the mold 38 to rise.

After the mold 38 is separated from the green sheet 30 and the electrode protective layer 37 as shown in FIG. 2H, the partition wall 8 is fired while passing through a temperature raising, holding, and cooling zone. In this firing process, after the burnout (Binder burn out) of the organic material in the green sheet 30 is burned out, crystal nuclei are formed and grown on the inorganic materials at a temperature higher than the burnout.

However, the barrier rib manufacturing method using the LTCCM method requires a pressure of 150 kgf / cm ² or more because of low fluidity when forming the green sheet 30 having the composition ratio as shown in Table 1. In the case of molding at a high pressure as described above, the pressure difference is different between the portion where the pressure is applied on the substrate 32 and the portion that is not. That is, the polarization pressure is generated on the substrate 32, so that the height of the partition wall 8 is not uniform as shown in FIG. In order to make the height of the non-uniform partition 8 uniform, a polishing step is required. In particular, since the fluidity of the green sheet 30 is low during molding, it is difficult to form a partition having a high aspect ratio.

Accordingly, it is an object of the present invention to provide a lower plate of PDP and a method of manufacturing the same that can improve the formability of the partition wall.

1 is a perspective view showing a surface discharge type plasma display panel of an AC driving method.

2A to 2H are diagrams showing step by step manufacturing methods of a lower panel of a plasma display panel using a conventional LTCCM method.

3 is a view showing the shape before and after firing of the partition wall shown in FIG.

4A to 4G are diagrams illustrating a method of manufacturing a lower plate of a plasma display panel according to an exemplary embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

2, 64 address electrode 4 sustain electrode pair

6: phosphor 8: partition wall

10: protective film 12, 18: dielectric layer

14, 32, 60: lower substrate 16: upper glass substrate

30, 60: green sheet 34: glaze layer

37: electrode protective layer 38, 68: mold

66: paste layer

In order to achieve the above object, the lower plate of the plasma display panel according to the present invention is a green sheet bonded on a substrate, an address electrode printed on the green sheet, a paste layer formed on the green sheet to cover the address electrode the provided with a partition wall formed by molding the paste layer, _{ZnO, B 2 O 3, MgO} , SiO 2, and a first compound containing _{CuO, ZnO, B 2 O 3} , MgO, SiO 2, CuO, TiO mixing a second compound containing a _second and, the first compound and the second compound is 1: 1 to 2: is mixed at a mixing ratio of 1 wherein the first compound is 27 wt% ZnO, 32 wt% B ₂ O ₃ , 18 wt% MgO, 23 wt% SiO _2. The second compound comprises 27 wt% ZnO, 23 wt% B ₂ O ₃ , 18 wt% MgO, 23 wt% SiO ₂ , 9 wt% K ₂ O , and a TiO _2. lower panel manufacturing method of the PDP according to the present invention is bonded to the green sheet onto a substrate Printing an address electrode on the green sheet; forming a paste layer of the composition on the green sheet on which the address electrode is printed; And pressing the mold in which the partition-shaped grooves are formed to form the partition and firing the paste layer formed into the partition.

Other objects and features of the present invention in addition to the above objects will become apparent from the description of the embodiments with reference to the accompanying drawings.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 4A to 4G.

4A to 4G illustrate a method of manufacturing a lower plate of a PDP according to an embodiment of the present invention.

4A to 4G, the PDP according to the present invention includes partition walls formed by forming a paste layer 66 having an inorganic composition having a low shrinkage ratio on the green sheet 60.

Referring to FIG. 4A, a green sheet 60 is manufactured. The green sheet 60 is a glass powder, an organic solution, a plasticizer, a binder, an additive, etc. are mixed in a predetermined ratio. For example, inorganic materials of ZnO-B ₂ O ₃ -MgO-SiO ₂ and ZnO-B ₂ O ₃ -MgO-SiO ₂ -Al ₂ O ₃ are added to the green sheet 60. This composition is placed on a polyester film and molded into a sheet using Doctor Blading, followed by drying to complete the green sheet 60. Titanum is mainly used as a material of the substrate 62 to which the green sheet 60 is bonded. Titanium may be manufactured to have a thickness thinner than that of other glass and ceramic materials because of its greater strength and heat resistance than glass or ceramic substrates, and may reduce thermal and mechanical deformation of the substrate 62. In addition, since titanium has a high reflectance, light emission efficiency and luminance may be improved by reflecting visible light that is transmitted toward the substrate 62, that is, back scattered, toward the display surface.

In order to bond the substrate 62 and the green sheet 60, as shown in FIG. 4B, a glaze is sprayed onto the substrate 62 and then fired at a temperature of 500 to 600 ° C. The glaze layer is formed. The glaze layer serves as a bonding agent and the green sheet 60 is placed on the glaze layer and the lamination process is performed to bond the substrate 62 and the green sheet 60 to each other. The lamination process is a process of adhering the substrate 62 and the green sheet 60 while applying a uniform pressure and temperature.

As shown in FIG. 4C, an address electrode 64 is printed on the green sheet 60.

Subsequently, a paste layer 66 having a predetermined thickness is formed on the green sheet 60 on which the address electrode 64 is formed as shown in FIG. 4D. Paste layer 66 is formed of a material having a low shrinkage ratio, mixing the _{ZnO-B 2 O 3 -MgO-} SiO 2 -CuO and _{ZnO-B 2 O 3 -MgO-} SiO 2 -CuO-TiO 2 at a predetermined ratio Has a composition. At this time, the paste layer 66 simultaneously performs the function of the dielectric layer protecting the address electrode 64. The paste layer 66 having such a composition has a smaller shrinkage rate than the conventional green sheet, so that the partition wall shape before and after firing is not deformed. The thickness and particle size (Particle Size Distribution: PSD) of the paste layer 66 are adjusted to secure matching with the green sheet 60. On the other hand, CuO in the material of the paste layer 66 serves to prevent the electrode from yellowing when a discharge voltage is applied. For example, a first compound comprising 27 wt% ZnO, 32 wt% B ₂ O ₃ , 18 wt% MgO, 23 wt% SiO ₂ , and 27 wt% ZnO, 23 wt% B ₂ O ₃ , 18 wt% MgO, 23 wt% SiO ₂ , wt%, 9 wt% K ₂ O, TiO ₂ (10%) are mixed in the range of 1: 1 to 2: 1.

ZnO can lower the glass softening point and control the CTE. The content of ZnO is selected in the range of 5 to 35% by weight and the CTE is excessively reduced when the composition ratio is added at 40% by weight or more.

B ₂ O ₃ is a glass forming element for extending the vitrification range of the elemental element and is included in 10 to 32% by weight, preferably 22% by weight. When the glass is 40% by weight or more, phase separation of the generated glass easily occurs.

In addition, SiO _{2 is} also a glass forming element and should be selected to 10 to 35% by weight, preferably 15 to 22% by weight. If SiO ₂ is 30% by weight or more, the softening point of the glass is excessively increased to slow down the viscosity change through the softening point, thereby making it difficult to defoaming.

K ₂ O lowers the melting point of the glass and adjusts the CTE.

The substrate 62 is heated near the softening point of the organic binder in order to increase the fluidity of the green sheet 60 bonded on the substrate 62. The composition of Forsterite, Codierite, ZrO ₂ , Al ₂ O _3, etc. is added to the green sheet 60, thereby increasing the flow temperature when using glass powder having a softening point lower than the crystallization temperature. .

In this state in which the flowability of the green sheet 60 is increased, as shown in FIG. 4E, the mold 68 having the grooves 68a having the opposite shape to the partition wall is aligned on the substrate 62.

As shown in FIG. 4F, the mold 68 is pressed onto the substrate 62 at approximately a predetermined pressure. When the mold 68 is pressed, the green sheet 60 and the paste layer 66 are moved into the grooves 68a of the mold 68 to rise.

After the mold 68 is separated from the green sheet 60 and the electrode protective layer 66 as shown in FIG. 4G, the partition wall is fired while passing through a temperature raising, holding, and cooling zone. This firing process is carried out at a temperature of 700 ~ 850 ℃ to burn off the organic material in the green sheet (60). Thereafter, at the firing temperature, the glass is produced and grown into glass-ceramic.

As described above, in the PDP barrier material and the barrier rib manufacturing method according to the present invention, a paste layer having a composition having a low shrinkage ratio is formed on the green sheet. Since the paste layer having a low shrinkage rate is formed on the green sheet, the partition wall shape before firing can be maintained as it is even after baking after forming into a partition wall shape. In other words, the formability of a partition can be improved. In addition, the partition material and the partition wall manufacturing method of the PDP according to the present invention can omit the upper surface grinding process as compared to the prior art can simplify the process can reduce the process cost. Furthermore, the molded partition can have a high aspect ratio and can improve uniformity.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (6)

A green sheet bonded to the substrate, An address electrode printed on the green sheet; A partition wall formed by molding a paste layer formed on the green sheet to cover the address electrode, The paste layer is mixed with a second compound including _{ZnO, B 2 O 3, MgO} , SiO 2, and a first compound containing _{CuO, ZnO, B 2 O 3} , MgO, SiO 2, CuO, TiO 2, wherein The lower panel of the plasma display panel, wherein the first compound and the second compound are mixed in a mixing ratio of 1: 1 to 2: 1. delete The method of claim 1, The first compound comprises 27 wt% ZnO, 32 wt% B ₂ O ₃ , 18 wt% MgO, 23 wt% SiO ₂ , Wherein said second compound is 27 wt% ZnO, 23 wt% B ₂ O _3, 18 wt% MgO, 23 a lower plate of a plasma display panel characterized in that it comprises a weight% SiO _2, 9 wt% K ₂ O, TiO ₂ . Bonding the green sheet onto the substrate; Printing an address electrode on the green sheet; Forming a paste layer on the green sheet on which the address electrode is printed to cover the address electrode; Pressing a mold having a partition-shaped groove formed on the paste layer to form a partition wall and firing the paste layer formed in the partition wall shape, The paste layer is mixed with a second compound including _{ZnO, B 2 O 3, MgO} , SiO 2, and a first compound containing _{CuO, ZnO, B 2 O 3} , MgO, SiO 2, CuO, TiO 2, wherein The first compound and the second compound is a barrier rib manufacturing method of the plasma display panel, characterized in that the mixing ratio of 1: 1 to 2: 1. delete The method of claim 4, wherein The first compound comprises 27 wt% ZnO, 32 wt% B ₂ O ₃ , 18 wt% MgO, 23 wt% SiO ₂ , Wherein said second compound is 27 wt% ZnO, 23 wt% B ₂ O _3, 18 wt% MgO, 23 a lower plate of a plasma display panel characterized in that it comprises a weight% SiO _2, 9 wt% K ₂ O, TiO ₂ Manufacturing method.