JPH07114879A - Manufacture of porous ceramic thin plate for plasma display panel - Google Patents

Abstract

PURPOSE:To manufacture a porous ceramic thin plate formed in thin plate thickness and thin wall thickness between fine holes further with high accuracy thereof for using in manufacturing a plasma display panel. CONSTITUTION:High purity alumina material powder of 0.5mum or less mean grain size is used to manufacture an alumirma ceramic thin plate 10 of 0.25mm or less thickness having 45kg/mm<2> or more strength. This ceramic thin plate is coated with a porous mask 14 formed of an elastic material, and by blowing grinding particles by a sandblasting method, fine holes 18 are high accurately drilled in the ceramic thin plate.

Description

Detailed Description of the Invention

[0001]

[Object of the Invention]

FIELD OF THE INVENTION The present invention relates to a method of manufacturing a porous ceramic sheet for a plasma display panel.

[0002]

2. Description of the Related Art Various systems have been studied for display of a wall-mounted television expected as a next-generation television, and a plasma display panel (PDP) is one of them. A PDP is one in which a large number of fine holes are regularly formed in a thin dielectric plate, a gas is filled in each fine hole, and an electrode matrix is arranged to form a discharge cell, which is sandwiched between glass plates. . In a PDP of a general size, the diameter of the discharge cell is about 0.55 mm, the distance between the cells (core-to-core distance) is about 0.7 mm, and therefore the minimum wall thickness between the cells is about 0.15 mm. .

The porous dielectric thin plate used for forming the discharge cell of the PDP has a small plate thickness (about 0.2 mm), a high accuracy of the distance between cells, and an excellent insulating property.
It is required to have excellent heat resistance.

From the viewpoint of insulation and heat resistance, ceramic is suitable as a material for the porous dielectric thin plate for PDP, but a large number of fine holes for discharge cells are formed on the thin ceramic plate having low toughness with high precision. It is technically difficult to form them at minute intervals, and it has not been realized to date that the porous dielectric thin plate for PDP is formed of ceramics.

That is, a laser processing method, a punching method, and a sandblasting method are known as general-purpose processing techniques for producing a porous ceramic plate.

In the laser processing method, a hole is made in a ceramic plate by a carbon dioxide laser or the like.
The porous thin plate for PDP has a problem that the ceramic thin plate is cracked by the heat shock during processing because the wall thickness between the micropores is very thin (that is, about 0.15 mm) as described above. Can not be applied to the manufacture of.

In the punching method, holes are mechanically formed in a green sheet before firing using a die, and then firing is performed. However, since shrinkage during firing is large, a highly accurate hole-tolerance is required. It is impossible to manufacture a thin ceramic plate for PDP.

The sandblast method is disclosed in, for example, Japanese Patent Laid-Open No. 62-251.
As disclosed in 073 and JP-A 1-295764, a ceramic plate is perforated by spraying grindable particles, but in the case of a porous thin plate for PDP, the plate thickness is thin (0. (About 2 mm), and because the wall thickness between the fine holes is thin, the ceramic thin plate is also cracked and the PD
It could not be applied as it is to the production of porous thin plates for P.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a plasma display panel (PDP) having a small plate thickness, a small wall thickness between fine holes, and a highly accurate hole tolerance.
It is an object of the present invention to provide a method capable of manufacturing a porous ceramic thin plate for use.

[0010]

[Constitution of the invention]

The method for producing a porous ceramic thin plate for a plasma display panel according to the present invention uses a high-purity alumina raw material powder having an average particle size of 0.5 μm or less and 45 kg / mm ² Alumina-ceramic thin plate having the above strength and a thickness of 0.25 mm or less is manufactured, a porous mask made of an elastic material is covered on the ceramic thin plate, and the ceramic thin plate is perforated by spraying abrasive particles by a sandblast method. It is characterized by that.

By using fine alumina powder having an average particle size of 0.5 μm or less, the sintering density of the ceramic thin plate can be increased. That is, by reducing fine pores, a high-strength alumina-ceramic thin plate having a strength of 45 kg / mm ² or more can be obtained. The ceramic thin plate of this level of strength can withstand the impact of sandblasting even when the plate thickness is reduced to 0.25 mm or less, and can process fine holes without causing cracks.

The mask can be formed of an elastic material such as polyurethane foam, and fine holes are formed with high precision according to the matrix pattern of the discharge cell of the PDP by photolithography. The mask is attached to a ceramic thin plate and abrasive particles are sprayed. An alumina-based abrasive can be used as the abrasive particles. The abrasive particles can be sprayed with high-pressure air or in the form of a slurry containing water.

Along with the spraying of the abrasive, the material of the portion of the ceramic thin plate which is not covered by the mask is scraped off and fine holes are punched in the thin plate. Since the fine holes are formed in the mask with high precision, the precision of the fine holes in the ceramic thin plate can be increased by performing sandblasting using the mask.

In a preferred embodiment of the present invention, in order to produce a porous ceramic thin plate for a PDP for a large screen, a plurality of ceramic thin plates are juxtaposed adjacent to each other, and thus a plurality of juxtaposed ceramic thin plates are formed. A common mask is covered and sandblasting is performed.

[0015]

Example A dispersant, a binder, and a plasticizer were added to a high-purity alumina raw material powder having an average particle size of 0.5 μm or less, mixed, dispersed, and adjusted in viscosity, and then a green sheet was manufactured using a doctor blade. Burn this green sheet and
Thickness having a 3-point bending strength of 5 kg / mm ² or more 0.2
A 5 mm alumina ceramic thin plate 10 was obtained.

Next, as shown in FIG. 1, fine holes 12 having a diameter of about 0.55 mm are formed at a pitch of about 0.7 mm on a polyurethane foam by a photolithography method, and a mask 1 is formed.
I made 4. This mask 14 was attached to the ceramic thin plate 10 as shown in FIG. 1, and alumina-based abrasive particles were blown together with high pressure air from a nozzle 16 of a sandblasting device. Similarly, a mask 14 was attached to the back surface of the ceramic thin plate 10 and sandblasting was performed from the back surface.

Along with the spraying of the grinding particles, the portion of the ceramic thin plate 10 which is not covered with the mask 14 is ground, and the fine holes 18 corresponding to the pattern of the fine holes 12 of the mask 14 are punched to form a porous ceramic for PDP. A thin plate 20 was obtained. This thin plate 20 was cut into an appropriate size and shape with a dicing saw to obtain a final product.

As a comparative example, an alumina-ceramic thin plate having a thickness of 0.25 mm was manufactured under the same conditions using alumina powder having a particle size of about 2 μm, and sandblasting was performed using the same mask. The thin plate was cracked on the way and the fine holes could not be penetrated. Apparently, this is because the strength of the ceramic thin plate was insufficient.

FIG. 2 shows another embodiment of the present invention suitable for producing a porous ceramic thin plate for a PDP for a large screen. As shown, for example, six ceramic thin plates 10
Are juxtaposed adjacent to each other and fixed with wax or the like.
A large-sized mask is put on this, and the nozzle 16
The abrasive particles are sprayed while scanning. By doing so, it is possible to obtain a highly accurate porous ceramic thin plate for PDP even with a large size.

[0020]

According to the method of the present invention, fine holes can be formed with high precision without destroying a thin ceramic plate, so that a plasma display panel (PD) can be formed.
It is possible to realize a porous ceramic thin plate suitable for manufacturing P).

According to a preferred embodiment of the present invention,
It is possible to obtain a highly accurate porous ceramic thin plate that can be used for a large size plasma display panel.

[Brief description of drawings]

FIG. 1 is a partial cutaway perspective view showing the method of the present invention.

FIG. 2 shows a plurality of ceramics juxtaposed in accordance with a preferred embodiment of the present invention.

[Explanation of symbols]

10: Ceramic thin plate 12: Micropores of mask 14: Porous mask 18: Micropores of ceramic thin plate 20: Porous ceramic thin plate for plasma display panel

Claims (2)

[Claims] 1. Alumina powder having an average particle size of 0.5 μm or less and a thickness of 0.2 having a strength of 45 kg / mm ² or more.
For a plasma display panel, characterized in that a dense alumina ceramic thin plate of 5 mm or less is manufactured, a porous mask made of an elastic material is covered on the ceramic thin plate, and abrasive particles are sprayed to perforate the ceramic thin plate. A method for manufacturing a porous ceramic thin plate. 2. A plasma display for a large screen.
In order to manufacture a porous ceramic thin plate for a panel, a plurality of the ceramic thin plates are juxtaposed adjacent to each other, a plurality of the ceramic thin plates thus juxtaposed are covered with one common mask, and abrasive particles are sprayed. A method of manufacturing a porous ceramic thin plate for a plasma display panel according to claim 1.