JP2002373588A - Plasma display panel and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma display panel of a long life having a high stability without luminance deterioration over aging. SOLUTION: On at least one substrate in a pair of substrates to oppose via a discharging space, a surface coat layer is formed which has a structure wherein an electroconductive electrode and a dielectric layer and a protective layer covering the electrode are successively laminated, and which has an opening part on the protective layer surface.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma display panel, and more particularly to an opposed three-electrode surface discharge type AC plasma display panel and a method of manufacturing the same. It relates to a protective layer and a surface coat layer.

[0002]

2. Description of the Related Art A plasma display panel is a display that excites and emits a phosphor by ultraviolet rays generated by gas discharge to display an image. The discharge can be classified into an alternating current (AC) type and a direct current (DC) type based on the method of forming the discharge. The AC type is characterized by being superior to the DC type in luminance, luminous efficiency, and life. Furthermore, among the AC types, the reflection type surface discharge type is the most common because it is particularly outstanding in terms of luminance and luminous efficiency.

FIG. 4 is a cross-sectional view of a part of a pixel of a reflective AC surface discharge plasma display panel as an example of the related art. The structure and operation will be described below. Transparent insulating substrate (most commonly a glass plate is used)
Transparent electrode (ITO or SnO2 is used) on 401
A plurality 402 are formed. However, since the transparent electrode 402 has a high sheet resistance and cannot supply sufficient power to all pixels in a large panel, a thick silver film, an aluminum thin film,
The bus electrode 403 is formed of a laminated thin film of copper / chromium (Cr / Cu / Cr). The apparent bus resistance of the transparent electrode 402 is reduced by the bus electrode 403.
A transparent dielectric layer (low melting glass is used) 404 and a protective layer 405 made of magnesium oxide (MgO) are formed on these electrodes. Dielectric layer 404
Have a current limiting function peculiar to the AC type plasma display, which is a factor that can make the life longer than that of the DC type. The protective layer 405 becomes a dielectric layer 404 by electric discharge.
For protecting the metal from being sputtered away and having excellent sputter resistance and a high secondary electron emission coefficient (γ)
And has the function of reducing the discharge starting voltage.

[0004] On the front side substrate 401, a data electrode 407 for writing image data, a base dielectric layer 408, a partition 409, and a phosphor layer 410 are formed on a transparent insulating substrate 406 on the other rear side. Have been. Here, the data electrode 407 and the partition wall 409 are connected to the transparent electrode 4.
02, and the discharge cells 411 are formed in a space surrounded by two partition walls 409. In the discharge cells 411, neon (Ne) and xenon (Xe) are used as discharge gases. ) Is about 6
It is filled at a pressure of 6.5 kPa (500 Torr). Further, the partition 409 serves to partition adjacent discharge cells and prevent erroneous discharge and optical crosstalk.

An AC voltage of several tens of kHz to several hundreds of kHz is applied between the transparent electrodes 402 to generate a discharge in the discharge cell 411, and the phosphor layer 410 is excited by ultraviolet rays from the excited Xe atoms. The display operation is performed by generating visible light.

In such a plasma display panel, Si or Al is added to the MgO protective layer 405,
A proposal has been made to lower the impedance of the protective layer 405 and reduce the incidence of unlit cells (Japanese Patent Application Laid-Open No. 10-1998).
334809).

[0007]

[0005] One of the problems of the plasma display panel is the luminance degradation with time. This is caused by a decrease in the luminous efficiency due to the plasma damage of the phosphor, a change in the surface of the MgO protective layer due to the plasma damage (a decrease in the secondary electron emission coefficient), and the surface of the protective layer and the phosphor caused by the impurity gas mixed into the discharge gas. Such as surface contamination.

In the above conventional example, the protective layer is made of Si or A
By adding l, by lowering the impedance of the protective layer, the residual charge charged on the surface can be reduced, and non-lighting can be reduced. However, in the conventional example, it is not possible to prevent the luminance from decreasing over time due to the above-described causes. This is because even if Si is mixed into the protective layer having excellent sputter resistance, Si cannot be diffused into the discharge space as in the present invention.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and its object is to (1) gradually supply a protective layer surface free from damage due to discharge with the lapse of operation time, and (2) To provide a plasma display panel that does not significantly deteriorate in luminance over time, (2) to provide a plasma display panel that does not deteriorate with time by inactivating impurity gas mixed into a discharge space, and (3) to provide the plasma display panel that does not deteriorate with time. An object of the present invention is to provide a manufacturing method for manufacturing a plasma display panel.

[0010]

In order to achieve the above object,
The plasma display panel according to the first aspect of the present invention has a structure in which a conductive electrode, a dielectric layer covering the conductive electrode, and a protective layer are sequentially laminated on at least one of a pair of substrates facing each other via a discharge space. In addition, a surface coat layer is formed on a part of the surface of the protective layer, and the surface coat layer is gradually removed during operation, and a surface of the protective layer without damage due to electric discharge appears, so that the luminance is reduced. A plasma display panel without deterioration can be provided.

A plasma display panel according to a second aspect of the present invention is characterized in that the surface coat layer contains Si or Ge as a main component, and Si or Ge atoms generated when the surface coat layer is removed are reduced. In addition, a plasma display panel can be provided which does not deteriorate with time because it reacts and inactivates with the impurity gas mixed into the discharge space.

The plasma display panel according to a third aspect of the present invention is characterized in that the area occupied by the openings of the surface coat layer has a spatial distribution.

According to a fourth aspect of the present invention, in the plasma display panel, the protective layer is made of at least a metal oxide, a metal nitride, or a metal halide.

According to a fifth aspect of the present invention, there is provided the plasma display panel, wherein a molecule containing at least silicon atoms or germanium atoms is present in the discharge space, and inactivates the impurity gas mixed in the discharge space. This can provide a plasma display panel that does not deteriorate in luminance over time.

According to a sixth aspect of the present invention, in the method for manufacturing a plasma display panel, a conductive electrode and a dielectric layer covering the conductive electrode are formed on a substrate, and a protective layer and a surface coat layer are further formed. It is characterized in that a part is removed.

According to a seventh aspect of the present invention, in the method of manufacturing a plasma display panel, a conductive electrode, a dielectric layer and a protective layer covering the conductive electrode are formed on a substrate, and then a surface coat layer is formed on the protective layer via a mask. It is characterized by forming.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional perspective view of a plasma display panel 100 according to a first embodiment of the present invention. This plasma display panel 1
Reference numeral 00 denotes a display electrode 102 made of a transparent conductive material such as ITO or tin oxide (SnO 2) and a silver (Ag) thick film (thickness: 2 μm to 10 μm) on the display surface side glass substrate 101.
m), aluminum (Al) thin film (thickness: 0.1 μm or more)
1 μm) or a Cr / Cu / Cr laminated thin film (thickness: 0.1 μm).
(1 μm to 1 μm) are sequentially stacked, and furthermore, lead oxide (PbO) or bismuth oxide (Bi)
Dielectric layer 1 made of low melting point glass (thickness: 20 μm to 50 μm) mainly containing 2O3) or phosphorus oxide (PO4)
04 is formed by screen printing (which can also be formed by die coat printing or film lamination).
Here, the display electrode 1 in one pixel (pixel: PU)
Numeral 02 is composed of two electrodes (X, Y) arranged in parallel with each other at a predetermined interval, during which an AC voltage is applied to generate a discharge in the discharge space 111. Next, a protection layer 105 (thickness: 100 nm to 1000 nm) made of MgO for protecting the dielectric layer 104 from damage by plasma is formed and laminated by an electron beam evaporation method. Subsequently, a surface coat layer 106 made of Si1-xOx (where 0≤x <1) or the like is formed to a thickness of 1 nm to 1000 nm by an evaporation method, a plasma CVD method, a sputtering method, or a coating baking method.
(Nanometer = 10-9 m). Thereafter, a resist pattern was formed on the surface coat layer 106 by a general photolithographic method in which a resist was applied, exposed and developed through a photomask. Subsequently, the glass substrate 101 is placed in a commercially available dry etching apparatus, and the surface coat layer 106 below the resist is left using a gas such as SF6, CF4, NF3, or SiF4.
The other surface coat layer 106 is removed to form a rectangular opening 201. Further, the resist is removed by an O2 asher, and a pattern of the surface coat layer 106 is formed on the MgO layer 105. An example of the pattern created at this time is shown in FIG.
(A). FIG. 2A is a diagram showing a pattern of the surface coat layer 106 in one sub-pixel SU (however, a positional relationship between the display electrode 102 and the partition 109 is shown by a dotted line). The substrate 150 on the display surface side was configured as described above. Further, the display electrode 10 is formed by the above patterning.
2, the area of the surface coat layer 106 removed is:
It was approximately 40% to 60%.

On the other hand, a silver (Ag) thick film (thickness: 2 μm to 10 μm), an aluminum (Al) thin film (thickness: 0.1 μm to 1 μm) or C
r / Cu / Cr laminated thin film (thickness: 0.1 μm to 1 μm)
And an underlying dielectric layer 108 made of a low-melting glass (thickness: 5 μm to 20 μm) containing lead oxide (PbO), bismuth oxide (Bi2O3), or phosphorus oxide (PO4) as a main component. Further, partition walls 109 mainly composed of glass, and phosphor layers 110R, 11 of three colors (red: R, green: G, blue: B) for color display.
0G and 110B are sequentially laminated, and the substrate 17 on the rear side is provided.
0 is configured. Here, the underlying dielectric layer 108
This is for improving the adhesion between the phosphor layers 110R, 110G, 110G, and does not mean that the plasma display panel does not operate without it. The display surface side substrate 150 is arranged such that the display electrodes 102 and the address electrodes 107 are orthogonal to each other.
And the back side substrate 170 to form a discharge space 111 partitioned by the partition walls 109 for each sub-pixel SU in the line direction. By adjusting the height of the partition walls 109, the gap size of the discharge space 111 takes a predetermined constant value. Here, one pixel (pixel: P
U) is composed of three sub-pixels SU that emit light of each color of R, G, B in the line direction.

As described above, the display surface side substrate 150 and the rear side substrate 170 are opposed to each other, the periphery thereof is hermetically sealed, and a discharge gas consisting of a mixed gas of Ne and Xe is filled in the discharge space 111 with a predetermined pressure and mixed gas. Filling was performed at the same ratio to produce a plasma display panel (1) 100.

For comparison, a plasma display panel (A) for comparison was prepared in exactly the same manner as the panel (1) 100 except that the surface coat layer 106 was not formed in the plasma display panel (1) 100 described above. Was prepared.

The panels (1) and (A) were operated continuously, and the change over time in the light emission luminance was examined. As a result, 5
After the elapse of 000 hours, the luminance of panel (1) decreased by 10% as compared with the initial value of the operation, whereas the luminance of panel (A) decreased.
Has decreased by 40%. When panel (1) after 5000 hours had passed was disassembled and surface coat layer 106 was observed, the width of the pattern was reduced, and it
Area was gone.

As described above, the provision of the surface coat layer 106 having the openings reduces the decrease in the luminance of the plasma display panel 100 with time.
I think as follows. During operation of the plasma display panel, the plasma display panel is damaged by the plasma and the protective layer 1 is damaged.
The secondary electron emission coefficient (γ) of the surface 05 decreases, and the luminous efficiency decreases. However, in panel (1), the protective layer 10
The surface coat layer 106 covering a part of the five surfaces is sputtered by the plasma in the discharge space 111 and is gradually removed. At the same time, the surface of the MgO protective layer 105 that has not been subjected to plasma damage gradually appears.
It is considered that a decrease in the γ value of the entire gO protective layer 105 can be suppressed. Other causes of the luminance degradation of the plasma display panel include CO2 adsorbed on the surface of the protective layer 105 and the phosphor layers 110R, G, and B with time, the dielectric layer 104, and the base dielectric layer 108.
And the hydrocarbon gas contained in the partition walls 109 is gradually released into the discharge space 111, and the discharge efficiency of the panel is reduced by mixing these impurity gases into the discharge gas. When the surface coat layer 106 is removed by sputtering, Si atoms, which are the main components, react with carbon atoms, which are constituent atoms of the impurity gas, and are converted into non-gasified solid matter (silicon carbide) having a larger binding energy. I will. As a result, it is considered that the impurity gas molecules were prevented from floating in the discharge space 111 and the luminance of the panel was prevented from deteriorating. It is considered that the introduction of the surface coat layer 106 produced the above synergistic effect and prevented the luminance of the panel from deteriorating.

As the discharge gas, a mixed gas of He—Xe may be used in addition to the mixed gas of Ne—Xe. When Ar is added to these gases, the sputtering effect of the surface coat layer 106 is further enhanced. It is more preferable because the removal proceeds smoothly.

In the panel (1), the opening 201 of the surface coat layer 106 has a rectangular shape. However, the opening 201 may have an arbitrary shape. For example, a circular (including elliptical) opening 201 as shown in FIG. 2B (the size of the circle may be the same or different, and may be a polygon instead of a circle), and FIG. ) Or a triangular opening 201 as shown in FIG.
The results similar to the above are obtained in the opening 201 connected in parallel to the conductive display electrode 102 as shown in FIGS. The island-shaped openings 20 as shown in FIGS.
If it is 1, the opening is formed by the photolithography as described above. However, when the opening 201 is continuous as shown in FIGS. 2D to 2F, not only the photolithography but also the surface The opening 201 may be formed using a mask that covers the opening 201 when the coat layer 106 is formed. Further, after forming the entire surface of the surface coat layer 106 and forming the panel, an AC voltage (effective value in the range of 150 V to 300 V) is applied between the adjacent display electrodes 102 (X-Y) to form the discharge space 111 in the discharge space 111. Causing a discharge (so-called aging),
An opening may be formed by removing a part of the surface coat layer 106 by sputtering.

As is common to FIGS. 2A to 2F, it is preferable that the opening 201 is not provided in the vicinity of the partition wall 109 but disposed in the display electrode 102. Because the partition 1
The electric charge near 09 is difficult to erase and easily accumulates, and is a main cause of crosstalk. Therefore, by covering the MgO protective layer 105, which easily generates charges, it becomes difficult to generate charges, and crosstalk can be suppressed.

As shown in FIGS. 3A and 3B, for example, the surface coat layer 106 on one bus electrode 103 is provided.
By increasing the area of removal and locally widening the opening 201, the applied voltage at the time of addressing can be reduced, which is effective. Further, the partition 109 may be provided with a horizontal partition 301 to surround the discharge space 111 with the partitions 109 and 301, which is effective in preventing crosstalk.

(Embodiment 2) In the second embodiment of the present invention, in the plasma display panel (1) manufactured in the first embodiment, the area removal rate of the surface coat layer 106 is 5% to 20%. Plasma display panel (2), panel (3) with 25-45%, 60-80
%, And a panel (5) with 85% to 98% were prepared, and the change with time of the emission luminance was examined in the same manner as described above. Other components are the same as those described in the first embodiment, and a description thereof will be omitted.

As a result, in the panel (2), the luminance at the initial stage of operation was so low that it could not be put to practical use.
After 5000 hours, the brightness decreased by 35 to 40%. In the panel (3), the initial luminance was 85 to 100% of that of the panel (1), but after 5000 hours, the luminance decreased by 5 to 10%. Panel (4)
The initial luminance was 100 to 120% of that of the panel (1), but the luminance after lapse of 5000 hours was reduced by 10 to 20%.

From the above results, it can be said that the area removal rate of the surface coat layer 106 is preferably 25% or more and 80% or less, and most preferably 40% or more and 80% or less.

(Embodiment 3) In the plasma display panel 100 manufactured in Embodiment 1, a panel (6) in which SiH4 is mixed with a filled discharge gas in a volume ratio of 10 ppm to 1% was manufactured. Other components are the same as those described in the first embodiment, and a description thereof will be omitted.

When this panel (6) was examined for changes with time in light emission luminance in the same manner as in the first embodiment, all of them were 500
The luminance after 0 hour was reduced by 5% or less compared to the initial value. It was found to be superior to the panel (1) in which SiH4 was not mixed. The cause is considered as follows.

As described above, as time passes, CO2 adsorbed on the surface of the protective layer 105 and the phosphor layers 110R, 110G, 110B, the dielectric layer 104, the base dielectric layer 108, and the partition 109 are removed. Are gradually released into the discharge space 111, and the impurity gas is mixed into the discharge gas, thereby deteriorating the brightness of the panel.
However, in the plasma of the discharge space 111, the impurity gas molecules float in the discharge space 111 by mixing a gas having a function of reacting with these gases and converting it into a solid substance having a higher binding energy and not being gasified. And the luminance of the panel can be prevented from deteriorating. CO
2. The atoms that bond with the atoms (carbon atoms) constituting the impurity gas such as hydrocarbons with strong binding energy are Si and Ge (form a Si-C bond and a Ge-C bond). Therefore, the reason why the panel (6) in which SiH4 was mixed was less deteriorated in luminance than the panel (1) in which SiH4 was not mixed was because the number of Si atoms supplied by sputtering of the surface coat layer 106 was not yet enough and the panel was mixed with the discharge gas. It is considered that the SiH4 and the impurity gas molecules dissociated in the discharge space 111 to form Si-C bonds and adhere to the phosphor layers 110R, G, B and the surface of the protective layer 105.

The gas to be mixed with the discharge gas is Si
In addition to H4, Si2H6, Si3H8, SiF4, Si
H2F2, SiH3F, SiHF3, SiCl4, Si
HCl3, SiH2Cl2, SiH3Cl, GeH4,
Ge2H6, GeF4, Ge2F6, GeH3F, Ge
H2F2, GeHF3 or the like may be used. When the mixing amount of these gases is 10 ppm or less, there is no effect. When the mixing amount is more than 1%, ultraviolet rays emitted from Xe atoms are absorbed and the amount of ultraviolet rays reaching the phosphor layers 110R, G, and B decreases. This is not preferable because the panel luminance is reduced.

In the first to third embodiments, Si1-xOx is used for the surface coat layer. However, any material that can be easily sputtered by the plasma generated in the discharge space, such as Si1-xNx or Si1-xOx, may be used. xCx, Ge1
-XOx, Ge1-xNx, Ge1-xCx (where 0
≦ x <1), or Si1-xyGexOy, Si
1-xyGexNy, Si1-xyGexCy (where 0 ≦ x <1, 0 ≦ y <1), Si1-xyCxO
y, Si1-xyCxNy (where 0 ≦ x <1, 0 ≦ y
<1), Ge1-xyCxOy, Ge1-xyCx
Even when Ny (where 0 ≦ x <1, 0 ≦ y <1) is used, the same effect as described above can be obtained.

In the first to third embodiments, the MgO film is used as the protective layer. However, CaO, BaO, Y2O
3, metal oxides such as La2O3, CeO2, HfO2 and mixed oxides, and III- such as AlN, GaN, BN, etc.
Group V compound, MgS, ZnS, BeSe, MgSe, M
II-VI group compounds such as gTe, MgF, LaF3, Ce
Any material, such as a metal halide such as F4 and HfF4, which is not easily damaged by plasma and has a high secondary electron emission coefficient, may be used.

As can be seen from the above description, the plasma display panel of the present invention has no change in luminance over time and has high stability in operation.

[0038]

According to the present invention, it is possible to provide a plasma display panel which is stable and has a long life without luminance change with time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional perspective view schematically illustrating a configuration of a plasma display panel according to an embodiment of the present invention.

FIG. 2 is a diagram showing a surface coat layer pattern shape used in an embodiment of the present invention.

FIG. 3 is a view showing a pattern shape of a surface coat layer used in an embodiment of the present invention.

FIG. 4 is a cross-sectional view schematically showing a configuration of a conventional plasma display panel.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 plasma display panel 101 display surface side glass substrate 102 display electrode 103 bus electrode 104 dielectric layer 105 protective layer 106 surface coat layer 107 address electrode 108 base dielectric layer 109 partition 110R phosphor layer (red) 110G phosphor layer (green) 110B phosphor layer (blue) 111 discharge space 112 rear glass substrate 150 display surface substrate 170 rear substrate 201 opening

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tetsuya Imai 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Masaru Brass 1006 Odaka Kadoma Kadoma City, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (72) Inventor Hidetaka Higashino 1006 Kazuma Kadoma, Kazuma, Osaka Prefecture F-term in Matsushita Electric Industrial Co., Ltd.

Claims (7)

[Claims] 1. A structure in which a conductive electrode, a dielectric layer covering the conductive electrode and a protective layer are sequentially laminated on at least one of a pair of substrates facing each other via a discharge space, and the surface of the protective layer is A plasma display panel having a surface coat layer having an opening formed thereon. 2. The plasma display panel according to claim 1, wherein the surface coat layer contains Si or Ge as a main component. 3. The area occupied by the opening of the surface coat layer is as follows:
The plasma display panel according to claim 1, wherein the plasma display panel has a spatial distribution. 4. The plasma display panel according to claim 1, wherein the protective layer comprises at least a metal oxide, a metal nitride, or a metal halide. 5. The plasma display panel according to claim 1, wherein a molecule containing at least a silicon atom or a germanium atom exists in the discharge space. 6. The method for manufacturing a plasma display panel according to claim 1, wherein a conductive electrode and a dielectric layer covering the conductive electrode are formed on a substrate, and further, a protective layer and a surface coat layer are formed. A method for manufacturing a plasma display panel, comprising removing a part of a coat layer. 7. The method for manufacturing a plasma display panel according to claim 1, wherein after forming a conductive electrode, a dielectric layer and a protective layer covering the conductive electrode on a substrate, the surface coat layer is protected via a mask. A method for manufacturing a plasma display panel, wherein the method is formed on a layer.