KR20020059491A - Method of Mounting Driver on Plasma Display Panel - Google Patents

Abstract

PURPOSE: A driver mounting method for PDP is provided to reduce size of the PDP device and manufacturing procedures by mounting a driver IC onto the lower plate through the use of LTCC-M(low temperature co-fired ceramic on metal) method. CONSTITUTION: A driver mounting method comprises a first step of forming a green sheet(60) onto a metal substrate(62); a second step of forming an electrode pattern onto the green sheet; a third step of forming an electrode protection layer(66) onto the green sheet so as to prevent dispersion of lead and protect the electrode pattern; and a fourth step of mounting a driver IC package(70) onto the metal substrate by aligning the driver IC package with solder balls attached to the driver IC package and melting the solder balls.

Description

Driver mounting method of plasma display panel {Method of Mounting Driver on Plasma Display Panel}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a plasma display panel, and more particularly, to a method of mounting a driver for a plasma display panel in which a drive integrated circuit is mounted on a lower plate by using a Low Temperature Cofired Ceramic on Metal (LTCC-M) method.

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 PDPs are not only thin and large in size, but also greatly improved in image 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 address electrode 2 and the sustain electrode pair 4 of the PDP are integrated circuits via a flexible printed circuit (FPC) 24 as shown in FIG. 2. A " IC " 26 is connected to a mounted circuit board 22. " PCB " The ICs 26 are data driver ICs for supplying red, green, and blue data to the address electrode 2 and scan / sustain driver ICs for supplying scan pulses and sustain pulses to the sustain electrode pairs 4, and the like. Divided. The ICs 26 are manufactured in the form of a ball chip array flip chip package, and solder pins are attached to the pins. These ICs are mounted on the PCB 22 by melting the solder balls onto the PCB 22. On the other hand, as shown in FIG. 3, the soldering prevention layer 36 is formed on the PCB 22 to cover the copper thin film 34 formed on the epoxy substrate 32. This lead spreading layer 36 is made of a solder resist containing a photosensitive material. The solder resist is 50 to 60 wt% of a photosensitive polymer, 0.1 to 10 wt% of a photoinitiator, 2 to 20 wt% of an inorganic pigment, and 10 to 20 wt% of an epoxy resin. Resin). The lead spreading layer 36 is patterned by an application process of applying the entire surface of the solder resist paste on the substrate 32, a process of drying the solder resist paste applied on the substrate 32, and an exposure / development / drying process. do.

However, the conventional PDP device has a disadvantage in that the preparation process is complicated because the size and thickness of the PCB 22 and the FPC 24 are inevitably increased, and an IC mounting process and an FPC connection process are required.

On the other hand, 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 a barrier rib manufacturing method, a screen printing method, a sand blasting method, an additive, a photosensitive paste method, and an LTCC-M (Low Temperature Cofired Ceramic on Metal) method are used.

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.

LTCC-M method has the advantages of low temperature process and simple process compared to other bulkhead manufacturing method.

4A to 4G show a stepwise manufacturing method of the partition wall using the LTCC-M method. First, the green sheet 30 as shown in Figure 4a 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 increased by reflecting visible light that is transmitted toward the substrate 32, that is, back scattered, toward the display surface.

Subsequently, the green sheet 30 is laminated and bonded to the substrate 32 as shown in FIG. 4B, and the address electrode 2 is formed on the green sheet 30 as shown in FIG. 4C.

On the substrate 30 on which the address electrode 2 is formed, as shown in FIG. 4D, 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 flowability of the green sheet 30 is increased, as shown in FIG. 4E, 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. 4F. 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. 4G, 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 temperatures higher than the burnout. After the partitioning, 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.

Accordingly, an object of the present invention is to provide a PDP driver mounting method for mounting a drive IC on a lower plate by using a Low Temperature Cofired Ceramic on Metal (LTCC-M) method.

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

2 is a perspective view schematically showing a driver integrated circuit mounting state in a conventional PDP apparatus.

FIG. 3 is a perspective view illustrating a soldering preventing layer formed on the printed circuit board of FIG. 2. FIG.

Figures 4a to 4g is a step-by-step showing a method of manufacturing a partition using a conventional LTCC-M method.

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 diagrams showing in stages a driver mounting method of a plasma display panel according to an exemplary embodiment of the present invention.

7 is a cross-sectional view showing a driver integrated circuit mounted on a substrate by the driver mounting method of the plasma display panel according to the 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

14,32,62: lower substrate 16: upper substrate

30,60: green sheet 36,66: electrode protective layer

38,68: Mold 70: Driver Integrated Circuit Package

72: payment

In order to achieve the above object, the driver mounting method of the PDP according to the present invention comprises the steps of forming a green sheet on a substrate, forming an electrode pattern on the green sheet, preventing the spread of lead on the green sheet and In addition, forming an electrode protective layer for protecting the electrode pattern, and mounting the driver integrated circuit on the substrate by aligning the driver integrated circuit with the soldering on the electrode protective layer and melting the soldering.

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, in the PDP according to the present invention, a driver IC package 70 is mounted on a metal substrate 62. When forming the partition wall, the green sheet 60 and the electrode protective layer 66 for forming the partition wall are stacked on the metal substrate 62. The electrode protection layer 66 serves to protect the address electrode 2 from plasma discharge and to prevent the spread of molten lead during mounting of the driver IC package 70.

6A to 6F show the partition wall manufacturing method using the LTCC-M method step by step. First, a green sheet 60 as shown in Figure 6a is produced. The green sheet 60 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 then molding the sheet into a sheet by doctor blading and drying it. .

The green sheet 60 is bonded onto the metal substrate 62 by lamination as shown in FIG. 6B.

Subsequently, the address electrode 6 is printed and dried on the green sheet 60 as shown in FIG. 6C.

On the substrate 60 on which the address electrode 2 is formed, the electrode protective layer 66 is printed on the entire surface as shown in FIG. 6D and then dried. The electrode protective layer 66 includes 40 to 80 wt% glass powder, 2 to 20 wt% inorganic additive, 5 to 50 wt% vehicle, 0.1 to 10 wt% dispersant, and the like.

After the electrode protective layer 66 is formed, secondary laminating is performed to increase the adhesion between the green sheet 60 and the electrode protective layer 66 having the address electrode 2 formed thereon. Subsequently, an organic material used as a binder, for example, poly-vinyl-butiral (hereinafter referred to as "PVB") to increase the fluidity of the green sheet 60 bonded on the substrate 62. The substrate 62 is heated below the softening point of.

In the state where the flowability of the green sheet 60 is increased, as shown in FIG. 6E, the mold 68 having the grooves 68a having the shape opposite to the partition wall is aligned on the display area of the substrate 62 and the substrate is operated at a pressure of about 150 kgf / cm 2 or more. Pressed on 62. When the mold 68 is pressed, the green sheet 60 and the electrode protective 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. 6F, 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 60 is burned out, crystal nuclei are formed and grown on the inorganic materials at a temperature higher than the burnout. After the partition wall firing, the driver IC package 70 with the lead 72 is aligned. Subsequently, the solder 72 is melted by a reflow process for melting the solder 72, and the molten lead is introduced into the address electrode 2 through a contact hole patterned on the electrode protective layer 66. As a result, the output terminals of the driver IC package 70 are electrically connected to the address electrode 2 as shown in FIG.

As described above, the driver mounting method of the PDP according to the present invention mounts the driver IC on the metal substrate using the LTCC-M method including the green sheet and the electrode protective layer forming process, and the electrode protective layer. The inorganic material and the vehicle may be mixed in it to prevent the spread of the molten lead. Therefore, according to the driver mounting method of the PDP according to the present invention, the size of the PDP device can be reduced and reduced in size, and there is no need to form a separate lead spreading prevention layer, thereby reducing the number of processes and minimizing material waste. .

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 (3)

In a method of forming a partition by forming a green sheet on a metal substrate and pressure-molding the green sheet with a mold, Forming the green sheet on a substrate; Forming an electrode pattern on the green sheet; Forming an electrode protective layer for preventing lead from spreading on the green sheet and protecting the electrode pattern; And mounting the driver integrated circuit on the substrate by aligning the driver integrated circuit with solder on the electrode protection layer and melting the solder. The method of claim 1, Pressing a mold having a groove having a shape opposite to a partition on the substrate on which the green sheet and the electrode protective layer are stacked to form a partition on the display area of the substrate; Separating the mold from the substrate; And firing the molded partition wall. The method of claim 1, The electrode protective layer comprises 40 to 80 wt% glass powder, 2 to 20 wt% inorganic additive, 5 to 50 wt% vehicle, and 0.1 to 10 wt% dispersant. Driver mounting method of panel.