KR100392959B1 - Method of Fabricating Back Plate of Plasma Display Panel - Google Patents

Abstract

The present invention relates to a lower plate of a plasma display panel and a method of manufacturing the same to reduce the material cost and reduce the defective rate.

The lower plate of the plasma display panel and the method of manufacturing the same according to the present invention pressurize the first green sheet with a mold to form partition walls and form a printed circuit on the second green sheet formed on the substrate for the driving circuit. In addition, a lower plate of the plasma display panel and a method of manufacturing the same according to the present invention mount a driver integrated circuit package for driving electrodes on a metal substrate on the driving circuit board, and the metal substrate on which the partition wall is formed and the driving circuit board. Connect electrically.

Description

Bottom plate of plasma display panel and manufacturing method thereof {Method of Fabricating Back Plate of Plasma Display Panel}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel and a method for manufacturing the same, and more particularly, to a lower panel of a plasma display panel and a method for manufacturing the same, which reduce material costs and reduce defective rates.

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, an AC drive type PDP including a lower substrate 14 on which an address electrode 2 is mounted and an upper substrate 16 on which a pair of sustain electrodes 4 are mounted is illustrated. On the lower 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 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.

The screen printing method has the advantages of a simple process and low manufacturing cost, but there is a problem of repeating the screen and glass substrate 14 alignment, printing and drying of the glass paste several times in every printing. 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, and thus the glass substrate 14 is cracked or damaged.

The addition method has an advantage in that the partitions 8 are formed on the large-area substrate, but it is difficult to separate the photoresist and the glass paste so that a residue remains or the partitions are collapsed when forming the partition.

The photosensitive paste method is not only difficult to expose the photosensitive paste to the lower portion of the photosensitive paste, but also has a disadvantage that the photosensitive paste is expensive.

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

2A to 2G show a stepwise manufacturing method of the partition wall 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 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 32, that is, backscattered, toward the display surface.

Subsequently, the green sheet 30 is laminated and bonded to the substrate 32 as shown in FIG. 2B, and the address electrode 2 is formed on the green sheet 30 as shown in FIG. 2C.

On the substrate 30 on which the address electrode 2 is formed, as shown in FIG. 2D, the dielectric slurry is completely printed and then dried to form the electrode protective layer 36. After the electrode protective layer 36 is formed, secondary laminating is performed to increase adhesion between the green sheet 30 having the address electrode 2 and the electrode protective layer 36. Subsequently, in order to increase the fluidity of the green sheet 30 bonded to the substrate 32, the substrate 32 is heated to a temperature lower than or equal to the softening point of the organic material used as the binder.

In the state where the fluidity of the green sheet 30 is increased, as shown in FIG. 2E, 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 then pressed onto the substrate 32 at a pressure of about 150 kgf / cm 2 or more, as shown in FIG. 2F. When the mold 38 is pressed, the green sheet 30 and the electrode protective layer 36 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 36 as shown in FIG. 2G, the partition 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. After the barrier firing, the reflective layer material such as titanium oxide (TiO 2) is printed on the electrode protective layer 36 and then fired before printing the phosphor 6.

The address electrode 2 and the sustain electrode pair 4 of the PDP are driven by signals supplied from driver integrated circuits (hereinafter referred to as " IC ") 26 (not shown). These driver ICs are mounted on an epoxy substrate and connected to the address electrode 2 and the sustain electrode pair 4 on the substrate via a flexible printed circuit (FPC) 24. It is common to be.

Recently, driver ICs are mounted on the metal substrate 32 as shown in FIG. 3 using the LTCCM method, or methods in which the metal substrate 32 and the driving circuit are integrated as shown in FIG. 4 have been proposed.

Referring to FIG. 3, a bottom plate of a PDP is shown in which driver IC packages 44 are bonded onto a metal substrate 32 in a ball grid array manner. In the display area, a low-temperature baking green sheet for forming a partition wall is bonded on the metal substrate 32. Input terminals of the driver IC packages 44 mounted on the metal substrate 32 are connected to an external main printed circuit board (hereinafter referred to as "PCB") via the FPC 42 or the input wirings. Connected.

According to the lower plate of the PDP as shown in FIG. 3, not only the mounting process of the driver IC packages 44 is required, but also a plurality of FPCs 42 and jacks / connectors for connecting an external main PCB (not shown) are required. There are disadvantages that require parts. In addition, when the number of electrode wirings on the bottom plate increases due to the high resolution, since a large number of driver IC packages must be installed on the limited bottom plate, component installation space is limited, and the input wires and the number of input wires may be large, and thus the input wires may be disconnected or shorted.

Referring to FIG. 4, at the bottom of the PDP proposed in Korean Patent Application No. 10-1998-0050911 filed by the applicant of the present application (Nov. 26, 1998), a driving circuit is integrated with the metal substrate 32 and the driver IC package 44 ) Is joined. An upper ceramic layer 46A is formed on the front surface of the metal substrate 32 to insulate the address electrode 2, and a driving circuit for driving the address electrode 2 is mounted on the rear surface of the metal substrate 32. First and second lower ceramic layers 46B and 46C are stacked. The upper and lower ceramic layers 46A, 46B, 46C are formed by laminating the green sheet on the metal substrate 32 and simultaneously firing. The address electrode 2 and the driving circuit are connected via the via holes 48 penetrating the ceramic layers 46A, 46B, 46C and the metal substrate 32. An inner wall of the via hole 48 is coated with an insulating film for insulation between the metal substrate and the signal wiring. A driving circuit is patterned in the lower ceramic layers 46B and 46C, which are electrically connected to the driver IC package 44.

The lower plate of the PDP as shown in FIG. 4 has a disadvantage in that it is difficult to form fine via holes on the metal substrate 32 and a process for additionally coating an insulating film therein is required.

In addition, the lower plate of the PDP as shown in Figs. 3 and 4 is very difficult to repair, replace, or reproduce the defective driver IC package or the defective wiring if a defect or wiring breakage (or short circuit) occurs in the driver IC package. That is, since the driver IC package 44 or the driving circuit is patterned on the ceramic layer of the metal substrate 32 formed based on the green sheet, repair, replacement, or regeneration are difficult.

Accordingly, it is an object of the present invention to provide a lower plate of a PDP and a method of manufacturing the same to reduce the material cost and reduce the defective rate.

1 is a perspective view showing a surface discharge type PDP of an AC drive system.

Figure 2a to 2b is a cross-sectional view showing a step of manufacturing a lower plate of the PDP using the conventional LTCCM method.

3 is a perspective view schematically illustrating a lower plate of a conventional plasma display panel in which a driver IC package is directly mounted on a lower substrate.

4 is a cross-sectional view schematically illustrating a lower plate of a conventional plasma display panel in which a driving circuit is integrated on a lower substrate.

5 is a perspective view schematically illustrating a lower plate of the plasma display panel according to an exemplary embodiment of the present invention.

6A through 6F are cross-sectional views 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: address electrode 4: sustain electrode pair

6: phosphor film 8: partition wall

10: protective film 12,18: dielectric thick film

14,32,52: lower substrate 16: upper substrate

30,46A, 46B, 46C, 50,60: Green sheet 36,54,66: Electrode protective layer

38,56: Mold 42: FPC

44,70: Driver IC package 68: Circuit pattern

72: soldering ball 80: connector

In order to achieve the above object, the lower plate of the PDP according to the present invention has a lower substrate on which electrodes are formed and a partition wall is formed by pressing the first green sheet, and a driving circuit having a second green sheet and a printed circuit formed thereon. And a driver integrated circuit package mounted on the substrate for the driving circuit to drive electrodes on the lower substrate. The lower substrate and the driving circuit substrate are electrically connected to each other.

A method of manufacturing a lower plate of a PDP according to the present invention includes the steps of forming a first green sheet on a metal substrate, pressing the first green sheet with a mold to form a partition wall, and a second green on a driving circuit board. Forming a sheet, forming a printed circuit on the second green sheet, firing the second green sheet, and a driver integrated circuit package for driving electrodes on the metal substrate on the substrate for the driving circuit. Mounting the circuit board and electrically connecting the metal substrate on which the barrier rib is formed and the substrate for the driving circuit.

Other objects and features of the present invention in addition to the above object 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. 5 to 7.

Referring to FIG. 5, the lower plate of the PDP according to the present invention includes a first metal substrate 52 on which a partition wall is formed, a first metal substrate 62 on which a driver IC package (not shown) is mounted, and first and second electrodes. And a connector 80 connected between the metal substrates 52 and 62. On the first metal substrate 52, the barrier rib is formed by pressing the low-temperature firing green sheet with a mold to form the barrier rib and simultaneously firing the barrier rib. On the second metal substrate 62, a passive element including a resistor R, an inductor L, and a capacitor C is formed along with an electrode pattern connected to the address electrode 2 on the first metal substrate 52. The IC package is mounted in a lead grid array.

6a to 6f show step by step manufacturing method of the PDP according to the present invention. First, green sheets 50 and 60 are manufactured. The green sheets 50 and 60 are formed by placing a slurry of glass powder, an organic solution, a plasticizer, a binder, and an additive in a predetermined ratio on a polyester film, forming a sheet in a doctor blading, and drying the sheet. Is produced.

The green sheets 50 and 60 are laminated and bonded to the first and second metal substrates 52 and 62 as shown in FIG. 6A. On the first and second metal substrates 52 and 62 to which the green sheets 50 and 60 are bonded, the electrodes 2 and 64 are printed and dried as shown in FIG. 6B, and the electrode protective layer 54 as shown in FIG. 6C. 66) is applied over the entire surface. After the electrode protective layers 54 and 66 are formed, secondary lamination is performed to increase the adhesive force between the green sheets 50 and 60 and the electrode protective layers 54 and 66. Subsequently, in order to increase the fluidity of the green sheet 50 and the electrode protective layer 54 bonded on the first metal substrate 52, the first metal substrate 52 is heated below the softening point of the organic material used as the binder. .

In the state where the fluidity of the green sheet 50 is increased, as shown in FIG. 6D, the mold 56 having the grooves opposite to the partition wall is aligned on the first metal substrate 52 and then pressurized to form the partition wall. Then, passive element circuit patterns 68 such as resistors R, inductors L, and capacitors C included in the driving circuits are printed and dried on the second metal substrate 62.

After the mold 38 is separated from the green sheet 50 and the electrode protective layer 54 as shown in FIG. 6E, the partition wall formed is baked while being heated, maintained, and cooled. In this firing process, after the burnout (Binder burn out) of the organic material in the green sheet 50 is burned out, crystal nuclei are formed and grown on the inorganic materials at a temperature higher than the burnout. After partition wall firing, a reflective layer material such as titanium oxide (TiO2) is printed on the electrode protective layer 54 before printing the phosphor 6 and then fired. The green sheet 60, the electrode protective layer 66, and the passive element circuit pattern 68 formed on the second metal substrate are simultaneously fired. The driver IC package 72 with the soldering element 72 is aligned on the circuit pattern, and the driver IC package 72 is mounted by melting the soldering element 72 by a reflow process.

Finally, after facing the first and second metal substrates 52 and 62 as shown in FIG. 6F, the connector 80 is attached to the electrode pads on the first and second metal substrates 52 and 62 to form electrodes. 2,64) are electrically connected.

As described above, the lower plate of the PDP and the method of manufacturing the same according to the present invention use the LTCCM method to form barrier ribs and driving electrodes on any one of two metal substrates, and drive circuit driver IC packages and passive elements on other metal substrates. The circuit pattern is formed. Therefore, according to the lower plate of the PDP and the manufacturing method thereof according to the present invention, since the number of electrode wirings at the input terminal is reduced and the FPC is not necessary, the material cost can be reduced and the defective rate can be reduced. In addition, a via hole does not need to be formed on the metal substrate, and replacement or regeneration is possible only by replacing the second metal substrate when the driver IC package is defective or when the wiring is shorted or broken.

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 (8)

A lower substrate having an electrode formed thereon and a partition formed by pressing the first green sheet; A driving circuit board having a second green sheet formed thereon and a printed circuit formed thereon; A driver integrated circuit package mounted on the substrate for the driving circuit to drive electrodes on the lower substrate; And the lower substrate and the driving circuit substrate are electrically connected to each other. The method of claim 1, And a connector for electrically connecting the lower substrate and the substrate for the driving circuit. delete The method of claim 1, The driving circuit board is a lower panel of the plasma display panel, characterized in that the metal substrate. Forming an electrode and a first green sheet on the metal substrate; Pressing the first green sheet with a mold to form a partition wall; Forming a second green sheet on the substrate for the driving circuit; Forming a printed circuit on the second green sheet and firing the second green sheet; Mounting a driver integrated circuit package for driving electrodes on the metal substrate on the drive circuit board; And electrically connecting the metal substrate on which the barrier ribs are formed and the substrate for the driving circuit. The method of claim 5, Forming an electrode protective layer on the first green sheet to cover the electrode; Simultaneously firing the first green sheet and the electrode protective layer after the partition wall forming; And simultaneously baking the second green sheet and the printed circuit layer after the printed circuit is formed. delete The method of claim 5, The driving circuit board is a lower plate manufacturing method of the plasma display panel, characterized in that the metal substrate.