JPH10326563A - Manufacture of plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enlarge a process margin, and improve the defoaming property by forming a dielectric layer, which covers an electrode, of the mixture, which includes at least two kinds of glass powders having a different softening point. SOLUTION: In the case where two kinds of low melting point glass powder L and H are mixed with each other so as to raise the temperature, the low melting point glass powder L is firstly melted, and diffusion is generated between the low melting point glass powder themselves, and viscosity of the glass powder H having a high softening point is lowered by the diffusion with the melting of the low melting point glass powder L. In comparison with a case of using single low melting point glass powder, low viscosity profitable to the work can be maintained over a wide temperature range by using the mixture of the plural kinds of low melting point glass powders, thereby a process margin can be enlarged. Since viscosity can be lowered at a low temperature, defoaming property is improved. In the work, the glass powder is desirably formed into the paste and a sheet, which is distributed in a vehicle formed of the resin and the solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a plasma display panel. More specifically, the present invention relates to a method for manufacturing a dielectric layer constituting an indirect discharge type plasma display panel.

[0002]

2. Description of the Related Art Plasma display panels (hereinafter referred to as P
DP) is a self-luminous display device with high surface luminance. This PDP is capable of increasing the size of the display screen and increasing the display speed.
(Referred to as CRT) is attracting attention as a display device. In particular, the surface discharge type PDP, which realizes color display by using a phosphor, is expanding its use in the field of television images including high-definition television.

An indirect discharge type PDP has a structure in which a pair of substrates covered with a dielectric layer and having electrodes are opposed to each other via a predetermined discharge space, and an appropriate discharge gas is sealed in the space. ing. Here, in the above-mentioned PDP, the dielectric layer generally uses a paste obtained by dispersing a low-melting glass powder in a vehicle made of a solvent and a resin, and prints or transfers the paste to form a coating film. It is formed by drying and firing the coating film.

[0004]

The low melting point glass powder used for forming the dielectric layer is a single kind, and the firing temperature is generally such that the viscosity of the low melting point glass at the time of melting is about 10 ⁵ ps.
It is set to be as follows. In the case of a single type of low melting point glass powder, there is a problem that the defoaming property is deteriorated during firing because the process margin is narrow. When the defoaming property is deteriorated, dielectric breakdown occurs in a portion of the dielectric layer where bubbles are present, whereby display cannot be performed.

If the softening point of the low-melting glass powder is lowered in order to ensure the defoaming property, it is necessary to lower the forming temperature of the partition walls formed later and the protective layer of the dielectric layer. If the firing temperature is set to an extremely high temperature in order to secure the defoaming property, other materials constituting the PDP will be adversely affected. As a method for improving the defoaming property, JP-A-2-123
No. 635 describes a method of laminating a plurality of low melting point glass films having different softening points. However, in this method, since a plurality of dielectric layers need to be stacked, there is a problem that the number of steps is increased and the cost is increased. Further, each dielectric layer is made of a single kind of low-melting glass, so that the problem that the process margin is narrowed cannot be solved.

[0006]

According to the present invention, in a plasma display panel of an indirect discharge type in which electrodes are covered with a dielectric layer, the dielectric layer contains at least two kinds of glass powders having different softening points. A method for producing a PDP is provided, wherein the method is formed using a mixture.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of substrates that can be used in the present invention include a glass substrate, a quartz substrate, and a silicon substrate. Among them, a glass substrate is preferable because it is inexpensive. An electrode and a dielectric layer are formed on the substrate. Here, in the case of a surface discharge type PDP, one substrate is called a front substrate and the other substrate is called a rear substrate. The electrodes formed on the front substrate are not particularly limited, and known materials and configurations can be used. For example, there is a configuration in which a plurality of stripe-shaped transparent conductive films having a wide width and a metal film having a narrow width for supplementing the conductivity are formed on a substrate. In addition,
A wide transparent electrode is generally called a sustain electrode, and a narrow electrode is generally called a bus electrode. Here, the sustain electrodes are made of a metal oxide such as ITO (indium oxide + tin oxide) or nesa (tin oxide), for example, and a desired number and thickness are obtained by combining a film forming method such as vapor deposition with an etching method. , Width and spacing. On the other hand, the bus electrodes are made of Ag, Au, Al, Cu, C
r and a laminate thereof (for example, Cr / Cu / Cr) or the like, and are formed in a desired number, thickness, width, and interval by combining a film forming method such as a sputtering method and a vapor deposition method with an etching method. be able to.

[0008] On the other hand, the electrodes formed on the rear substrate are not particularly limited, and known materials and structures can be used. For example, it may be composed of a plurality of stripes. This electrode is generally called an address electrode. Here, the address electrodes are Ag, Au, Al, C
u, Cr and their laminates (eg, Cr / Cu / C
r) and the like, by combining a film forming method such as a sputtering method and a vapor deposition method with an etching method,
It can be formed with thickness, width and spacing.

Next, a dielectric layer is formed so as to cover the electrodes.
Is done. The dielectric layer is used for surface discharge during PDP driving.
Protects the electrodes from the impact of ions
It also fulfills its tasks. In the present invention, this dielectric layer is provided with a different softening point.
A mixture comprising at least two glass powders
Is formed as one of the features. Here the present invention
Examples of glass powder that can be used for PbO-S
iO_Two-B_TwoO_ThreeSystem, PbO-B_TwoO_Three-SiO_Two-Z
nO-based, PbO-SiO_Two-ZnO-based, Bi_TwoO_Three-S
iO_Two-B_TwoO_ThreePowder such as a system. Above powder
And R_TwoO (R = Li, Na, K, etc.), BaO, Ca
O, MgO, TiO_Two, ZrO _Two, Al_TwoO_Three, Na
F, P_TwoO_FiveMay be added. Soft glass powder
The formation point is determined by appropriately changing the composition, composition, etc.
Thus, the desired value can be adjusted.

Here, the principle of the present invention will be described with reference to FIG. The horizontal axis in FIG. 1 is temperature and the vertical axis is logarithmic representation of viscosity. In FIG. 1, the solid line shows the temperature-viscosity curves of two kinds of low melting point glass powders L and H having different softening points. When the two types of low melting point glass powders L and H are mixed and the temperature is increased, first, the low melting point glass powder L having a low softening point is melted. At this time, diffusion occurs between the low melting point glass powders, and the viscosity increases from the temperature at which melting starts. On the other hand, the viscosity of the low-melting glass powder H having a high softening point decreases due to diffusion accompanying the melting of the low-melting glass powder L. The broken line in FIG. 1 indicates this change in viscosity. Therefore, rather than using a single type of low-melting glass powder, it is possible to maintain a low viscosity that is advantageous for work over a wide temperature range by mixing a plurality of types of low-melting glass powder, thereby expanding the process margin. Becomes possible. Furthermore, since the viscosity can be reduced at a lower temperature than using a single kind of low melting point glass powder, the defoaming property can be improved.

In the above, the case where two kinds of low melting point glass powders are used has been described. However, the present invention is not limited to this case, and various modifications are possible. In the present invention, as can be seen from FIG. 1, in order to obtain a desired viscosity at the time of melting, it is preferable to include at least two kinds of low melting point glass powders having a high softening point and a low softening point. Furthermore,
The mixture containing the glass powder is preferably formed of a paste in which the glass powder is dispersed in a vehicle made of a resin and a solvent, or a resin sheet containing the glass powder.

[0012] The resin contained in the paste and sheet is not particularly limited, and known resins can be used in any case. Specific examples include (meth) acrylic resins such as polybutyl acrylate, 2-ethylhexyl polyacrylate, and polyacrylic acid, and cellulose resins such as methyl cellulose and ethyl cellulose. The mixing ratio of the resin and the low-melting glass powder is 0.1 to 20:
99.9 to 80 (% by weight) is preferred, and 0.1 to 10:
99.9-90 is more preferred. Here, if the mixing ratio of the resin is less than 0.1%, it is not preferable because the resin cannot be uniformly mixed. On the other hand, when the compounding ratio of the resin is more than 20%, the formed dielectric layer is unfavorably cracked.

The solvent contained in the paste includes:
Any solvent can be used as long as it can dissolve the resin, and is not particularly limited. Specifically, those having a high boiling point are preferable, and examples thereof include terpineol and butyl carbitol.
Next, as a method of forming the dielectric layer, in the case of using a paste, the paste is applied by a printing method or a transfer method, and then fired. In the case of using a sheet, the sheet is bonded by thermocompression bonding or the like. After that, a method of firing is given. The firing temperature varies depending on the material and the like contained in the mixture, but is, for example, 500 to 600 ° C.

It is preferable that the dielectric layer has a thickness of 10 to 50 μm. Further, a protective film such as MgO may be formed on the dielectric layer of the front substrate. Next, a partition is formed on the dielectric layer of the back substrate by a known method (for example, a sand blast method, a transfer method, or the like). It is preferable that a plurality of the partition walls are formed in a stripe shape between the address electrodes. Further, a phosphor layer is usually provided on the side surface of the partition and on the dielectric layer.

The PDP can be formed by causing the front substrate and the rear substrate thus formed to face each other so that the electrodes formed thereon are orthogonal to each other, and filling an appropriate discharge gas. More specifically, the PD of the present invention
Utilizing the method of manufacturing P, for example, a PDP as shown in FIG.
Can be formed.

FIG. 2 is a schematic perspective view corresponding to one pixel of a surface discharge type PDP of a general indirect discharge type. The PDP 1 having a three-electrode structure belongs to a reflection type according to the arrangement of phosphors. Is shown. In the PDP 1 of FIG. 2, a pair of glass substrates 2 and 5 are arranged to face each other. On the glass substrate 2, a pair of display electrodes X and Y are formed in parallel,
An alternating current (AC) driving dielectric layer 3 for maintaining discharge by wall charges on the glass substrate 2 so as to cover the display electrodes X and Y.
Is formed, and a protective film 4 is formed on the dielectric layer 3. On the other hand, a plurality of stripe-shaped address electrodes A are formed on the glass substrate 5 at positions orthogonal to the display electrodes X and Y when viewed in a plane, and a dielectric material is formed on the glass substrate 5 so as to cover the address electrodes A. Layer 6 is described. Further, a plurality of stripe-shaped barrier ribs 7 are formed between adjacent address electrodes A and in parallel with the address electrodes A. A phosphor layer 8 is formed on the side wall of the adjacent partition wall 7 and on the address electrode A. Next, reference numeral 9 denotes a discharge space, and a unit light-emitting region (hereinafter, referred to as a unit light-emitting region in the extending direction of the display electrodes X and Y)
(Referred to as EU) and the gap size is defined. The discharge space 9 is filled with an appropriate discharge gas.

In the PDP 1, as shown in FIG. 2, in each of three EUs corresponding to one pixel, a selected discharge cell for selecting display or non-display at the intersection of the display electrode Y and the address electrode A is defined. Have been. Also, the display electrode X
And Y, a main discharge cell is defined. Here, the phosphor layer 8 is provided between the partition walls 7 on the glass substrate 5 on the opposite side of the display electrodes X and Y in order to avoid impact by ions generated by surface discharge. The phosphor layer 8 emits light when excited by ultraviolet rays generated by surface discharge of the main discharge cells. Light generated in the surface layer of the phosphor layer 8 (on the side in contact with the discharge space 9) passes through the dielectric layer 3 and the glass substrate 2 and is emitted to the outside. That is, in the PDP 1, the outer surface of the glass substrate 2 becomes the display surface D.

Since the display electrodes X and Y are arranged on the display surface D side with respect to the phosphor layer 8, a wide transparent electrode is used to widen the surface discharge and minimize the shielding of the display light. It is composed of a conductive film 10 and a narrow metal film (bus electrode) 11 for supplementing its conductivity. PDP as above
Is a glass substrate 2 (front substrate) that covers the display electrodes X and Y and has a dielectric layer 3 for maintaining a discharge, and a glass substrate 5 (back substrate) that has a partition 7 for partitioning a discharge space 9.
The two glass substrates are bonded together.

[0019]

【Example】

Example 1 and Comparative Example 1 PbO—B ₂ O ₃ —SiO ₂ —ZnO having an average particle size of 3 μm
Low melting glass powder No. 1 (softening point: 475 ° C.) 2 (softening point: 585 ° C) [each of LS-31
62S, LS-3232 (manufactured by Nippon Electric Glass Co., Ltd.)] is mixed in a vehicle of 95% by weight of terpineol and 5% by weight of ethylcellulose at a ratio of 8: 2 (weight ratio), and dispersed by three rolls to prepare a paste. did. This paste was coated on a substrate by a screen printing method to form a coating film having a thickness of 30 μm, and dried at 130 ° C. for 30 minutes. This coating film was heated at a rate of 10 ° C./min to 400 ° C., and deresined at 400 ° C. for 10 minutes. After firing at 10 ° C./min and maintaining at 560 ° C., 570 ° C., 580 ° C. and 590 ° C. for 10 minutes,
The temperature was lowered to room temperature at about 5 ° C./min to form a dielectric layer. Table 1 shows the light transmittance of this dielectric layer at 500 nm.

The light transmittance of Comparative Example 1 was measured in the same manner as described above except that one kind of low melting point glass powder having a softening point of 480 ° C. was used instead of two kinds of low melting point glass powder. . The results are shown in Table 1.

[0021]

[Table 1]

As is evident from Table 1, in Example 1, the sintering temperature shows a stable light transmittance over a wide range of 560 to 590 ° C. Therefore, the process margin can be increased as compared with the comparative example.

Example 2 The same low melting glass powder as in Example 1 was used, and a green sheet (thickness: 50 μm) comprising 20% by weight of an acrylic resin and 3% by weight of dibutyl phthalate as a plasticizer was prepared. This was thermally bonded on a substrate, baked in the same manner as in Example 1, and the light transmittance was measured. The results obtained were the same as in Example 1.

[0024]

According to the present invention, it is possible to maintain a low viscosity which is advantageous for work over a wider temperature range than using a single kind of low melting point glass powder, so that a process margin can be expanded. In addition, the defoaming property can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of the principle of the present invention.

FIG. 2 is a schematic perspective view of a PDP of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 PDP 2, 5 Glass substrate 3, 6 Dielectric layer 4 Protective film 7 Partition 8 Phosphor layer 9 Discharge space 10 Transparent conductive film 11 Metal film A Address electrode D Display surface X, Y display electrode

Claims (1)

[Claims] 1. An indirect discharge type plasma display panel in which electrodes are covered with a dielectric layer, wherein the dielectric layer is formed using a mixture containing at least two kinds of glass powders having different softening points. Manufacturing method of a plasma display panel.