JP4715037B2 - Plasma display panel and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plasma display panel, particularly a counter three-electrode surface discharge AC plasma display panel and a manufacturing method thereof, and more particularly to a dielectric layer and a protective layer in order to stabilize operating characteristics and improve aging. .
[0002]
[Prior art]
The plasma display panel is a display that displays an image by exciting and emitting phosphors with ultraviolet rays generated by gas discharge. The discharge can be classified into an alternating current (AC) type and a direct current (DC) type. The feature of the AC type is that it is superior to the DC type in terms of luminance, luminous efficiency, and lifetime. Further, among the AC types, the reflection type surface discharge type is particularly common in terms of luminance and luminous efficiency, and this type is the most common.
[0003]
FIG. 4 shows a cross-sectional view of a part of a pixel of a reflective AC surface discharge plasma display panel as an example of the prior art. The structure and operation will be described below. A plurality of transparent electrodes (ITO or SnO 2 are used) 402 are formed on a transparent insulating substrate (most commonly a glass plate is used) 401. However, the transparent electrode 402 has a high sheet resistance, and a large panel cannot supply sufficient power to all pixels. Therefore, a thick silver film, an aluminum thin film, chrome / copper / chrome ( A bus electrode 403 made of a laminated thin film of (Cr / Cu / Cr) is formed. The bus electrode 403 apparently reduces the sheet resistance of the transparent electrode 402. 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. The dielectric layer 404 has a current limiting function peculiar to the AC type plasma display, and is a factor that can make the life longer than that of the DC type.
[0004]
A data electrode 407 for writing image data, a base dielectric layer 408, a partition 409, and a phosphor layer 410 are formed on the transparent insulating substrate 406 which is the other rear side substrate with respect to the front side substrate 401. . Here, the data electrode 407 and the barrier rib 409 are arranged so as to be orthogonal to the transparent electrode 402, and the discharge cell 411 is formed in a space surrounded by the two barrier ribs 409. Is filled with a mixed gas of neon (Ne) and xenon (Xe) as a discharge gas at a pressure of about 66.7 kPa (500 Torr). Further, the partition 409 functions to partition adjacent discharge cells and prevent erroneous discharge and optical crosstalk.
[0005]
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. The phosphor layer 410 is excited by ultraviolet rays from the excited Xe atoms to generate visible light. Generate and perform display operation.
[0006]
In such a plasma display panel, there has been proposed one in which Ar is added to a discharge gas composed of Xe and Ne to improve luminous efficiency (Japanese Patent Laid-Open No. 2000-156164).
[0007]
[Problems to be solved by the invention]
There is luminance deterioration with time, which is one of the problems of plasma display panels. This is due to deterioration of the phosphor due to plasma damage, a decrease in secondary electron emission coefficient due to sputtering of the MgO protective layer, and contamination of the protective layer and the phosphor surface with an impure gas mixed in the discharge gas.
[0008]
In the above conventional example, by adding Ar to the discharge gas, the discharge start voltage can be reduced due to the Penning effect, or higher brightness can be achieved with the same discharge voltage. However, although the brightness in the initial stage of operation can be increased in the conventional example, it is not possible to prevent the decrease in brightness over time due to the above-described causes.
[0009]
The present invention has been made in order to solve the above-mentioned problems. The object of the present invention is to (1) supply a gas having a penning effect gradually to the discharge space, and to prevent a luminance deterioration with time. (2) providing a plasma display in which impure gas mixed in the discharge space is deactivated to prevent luminance deterioration over time, and (3) providing a manufacturing method for manufacturing the plasma display. It is to be.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the plasma display panel according to claim 1 contains a conductive electrode and bismuth oxide or phosphorus oxide covering the conductive electrode on at least one of the pair of substrates opposed to each other through the discharge space. A dielectric layer made of glass and a protective layer made of a metal oxide are sequentially laminated, and a region having a high Ar atom density exists on the protective layer side of the dielectric layer In addition, since impurity atoms having a Penning effect are gradually supplied into the discharge space over time, a plasma display panel free from luminance deterioration can be provided.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings.
[0031]
(Embodiment 1)
FIG. 1 is a cross-sectional perspective view of a plasma display panel 100 according to the first embodiment of the present invention. The plasma display panel 100 includes a display electrode 102 made of a transparent conductive material such as ITO or tin oxide (SnO 2), a silver (Ag) thick film (thickness: 2 μm to 10 μm), aluminum (Al ) A bus electrode 103 composed of a thin film (thickness: 0.1 μm to 1 μm) or a Cr / Cu / Cr laminated thin film (thickness: 0.1 μm to 1 μm) is sequentially stacked, and lead oxide (PbO) or bismuth oxide (Bi 2 O 3). ) Or low-melting glass (thickness 20 μm to 50 μm) mainly composed of phosphorus oxide (PO 4) is formed by screen printing. Subsequently, the glass substrate 101 is placed in a commercially available ion implantation apparatus. Argon (Ar) ions are implanted into the surface of the dielectric layer 104 by simultaneously operating a dose amount and an acceleration voltage in a range of −0.1 kV to −400 kV. Ar ions are implanted in the vicinity of the surface of the dielectric layer 104, and the implanted depth ranges from 1 nm to 2000 nm (nanometers). Here, when the amount of Ar injected into the dielectric layer 104 is quantified by secondary ion mass spectrometry (SIMS), the distribution of Ar atoms in the depth direction from the dielectric surface is shown in FIG. It turned out to be like this. The maximum value of the Ar atom density was in the range of 2 × 1020 / cm3 to 2 × 1021 / cm3. Next, a protective layer 105 (thickness: 100 nm to 1000 nm) made of MgO that protects the dielectric layer 104 from plasma damage is formed by electron beam evaporation. The substrate on the display surface side was configured as described above.
[0032]
On the other hand, on the glass substrate 106 on the back side, a silver (Ag) thick film (thickness: 2 μm to 10 μm), an aluminum (Al) thin film (thickness: 0.1 μm to 1 μm), or a Cr / Cu / Cr laminated thin film (thickness: An address electrode 107 having a thickness of 0.1 μm to 1 μm, a partition wall 108, and phosphor layers 109R, 109G, and 109B of three colors (red: R, green: G, blue: B) for color display are sequentially stacked. It has been. The discharge space 110 is partitioned for each subpixel SU in the line direction by the barrier ribs 108, and the gap dimension of the discharge space 110 takes a predetermined constant value. Here, one pixel (pixel) is composed of three sub-pixels SU that emit light in R, G, and B colors side by side in the line direction. Further, as shown in FIG. 3, a base dielectric made of low melting point glass (thickness: 5 μm to 20 μm) mainly composed of lead oxide (PbO), bismuth oxide (Bi 2 O 3) or phosphorus oxide (PO 4) on the address electrode 107. The layer 301 may be formed. The underlying dielectric layer 301 improves the adhesion of the phosphor layers 109R, G, B, and does not mean that the plasma display panel will not operate without it.
[0033]
The display surface side glass substrate 101 and the back side glass substrate 106 obtained as described above are opposed to each other through the partition wall 108 so that the display electrode 102 and the address electrode 107 are orthogonal to each other, and the periphery is hermetically sealed. The discharge space 110 was filled with a discharge gas composed of a mixed gas of Ne and Xe at a predetermined pressure and mixing ratio, and a plasma display panel (1) 100 was manufactured.
[0034]
For comparison, in the plasma display panel (1) 100 described above, Ar ions are not implanted into the dielectric layer 100, and the other components are the same as those in the panel (1) 100, and the comparative plasma display panel (A). Was made.
[0035]
Panels (1) and (A) were continuously operated to examine the change in light emission luminance over time. As a result, the brightness of the panel (1) after the lapse of 5000 hours decreased to 90% compared to the initial value of the operation, whereas the panel (A) decreased to 60%.
[0036]
In FIG. 2A, the plasma display panel 100 in which the doping amount is controlled at the time of plasma doping and the maximum value of the Ar atom density is changed in a range of 1 × 10 18 atoms / cm 3 to 8 × 10 21 atoms / cm 3. Although produced, the same effect as described above was obtained. When the value of the maximum value of Ar atom density was made smaller than 1 × 10 18 atoms / cm 3, the luminance after 5000 hours had decreased to 70% or less of the initial value. Further, in the range where the maximum value of the Ar atom density is 1 × 10 18 atoms / cm 3 or more and 2 × 10 20 atoms / cm 3 or less, the luminance decrease rate decreases as the Ar atom density is increased, but 2 × 10 21 atoms / cm 3. As a result, voids such as bubbles were generated in the region of the dielectric layer 104 into which Ar ions were implanted, and the luminance after 5000 hours had decreased to 70% or less of the initial value.
[0037]
The plasma display panel 100 showing the Ar atom density distribution as shown in FIGS. 2B to 2F was manufactured by controlling the dose amount and the acceleration voltage at the time of ion implantation. The result was obtained. At this time, the peak value of the Ar atom density distribution was in the range of 1 × 10 18 atoms / cm 3 or more and 2 × 10 21 atoms / cm 3 or less.
[0038]
As described above, the reason why the luminance reduction rate with time of the plasma display panel 100 is reduced by implanting impurity ions such as Ar ions into the dielectric layer 104 is considered as follows. . Ar atoms implanted into the dielectric layer 104 are gradually released into the discharge space 110 by diffusion. Therefore, when Ar is mixed in the discharge gas composed of the Ne—Xe mixed gas, the discharge start voltage is reduced by the Penning effect, that is, the efficiency is increased. In other words, the increase in Ar contamination over time compensates for the efficiency reduction due to the deterioration of the phosphor layer 109 and the protective layer 105, and as a result, the reduction in luminance, which was a major problem of the plasma display panel, was suppressed. It is considered a thing.
[0039]
The impurity atoms implanted into the dielectric layer 104 may be any atoms that give a Penning effect to the discharge gas. If a mixed gas of Ne—Xe is used as the discharge gas, He is used in addition to Ar. Alternatively, Ar and He may be implanted simultaneously. When He—Xe is used as the discharge gas, Ne is preferable as the impurity atom implanted into the dielectric layer 104.
[0040]
Further, for the implantation of impurity atoms into the dielectric layer 104, a commercially available ion shower doping apparatus may be used in addition to the ion implanter.
[0041]
(Embodiment 2)
In the second embodiment of the present invention, in the plasma display panel 100 manufactured in the first embodiment, ion implantation is not performed after the dielectric layer 104 is formed, and after the formation of the protective layer (MgO) 105, the first embodiment is performed. A plasma display panel (2) in which Ar ions were ion-implanted as impurity atoms into the protective layer 105 was formed in the same manner as in the embodiment. When the Ar atom density in the film thickness direction in the MgO layer 105 was evaluated by SIMS, the distribution shape shown in FIG. However, the depth at the peak value of the Ag atom density was approximately 1 nm to 200 nm, and the peak value was 2 × 1020 / cm3 to 2 × 1021 / cm3. The other components are the same as those described in the first embodiment, and a description thereof is omitted here.
[0042]
When the panel (2) was examined in the same manner as in Embodiment 1 for the change in emission luminance over time, the luminance decreased to 80% of the initial value after 5000 hours. Compared with the comparative panel (A) produced in the first embodiment, it was confirmed that the rate of decrease in luminance was small and the change with time was small.
[0043]
Further, a plasma display panel having various peak values changed by controlling the dose amount at the time of Ar ion implantation was manufactured, and the change with time was examined in the same manner. When the peak value was 1 × 10 18 pieces / cm 3 or less, it was 5000. It was found that the luminance after the lapse of time decreased to 62% of the initial value. However, when the peak value exceeded 1 × 10 18 pieces / cm 3, the luminance started to increase after 5000 hours, and the luminance was almost maximum in the range of 2 × 10 20 pieces / cm 3 to 2 × 10 21 pieces / cm 3. When the peak value exceeded 2 × 10 20 pieces / cm 3, it was found that the luminance decreased rapidly and the luminance after 5000 hours became 70% or less of the initial value. When the panel at this time was disassembled and the surface of the MgO film 105 was observed with an SEM, it was confirmed that the MgO film 105 was deeply shaved. That is, by including Ar atoms in the MgO film 105, Ar is released into the discharge space 110 with the passage of time, and the decrease in luminance over time is reduced by the Penning effect. However, if too much is injected, the structure of the MgO film 105 is broken and brittle, and the operation of the panel causes the MgO film 105 to be sputtered and scraped, reducing the secondary electron emission coefficient of the MgO film 105 and reducing the luminance. Seems to have become prominent.
[0044]
From the above results, the peak density of impurity atoms contained in the protective layer 105 is preferably greater than 1 × 10 18 atoms / cm 3 and 2 × 10 21 atoms / cm 3 or less, more preferably 2 × 10 20 atoms / cm 3 to 2 × 1021 pieces / cm 3 or less.
[0045]
The impurity atoms implanted into the protective layer 105 may be any atoms that give a penning effect to the discharge gas. If a mixed gas of Ne—Xe is used as the discharge gas, He is used in addition to Ar. Alternatively, Ar and He may be implanted simultaneously. In the case where He—Xe is used as the discharge gas, Ne is preferable as the impurity atom implanted into the protective layer 105.
[0046]
(Embodiment 3)
In the plasma display panel 100 manufactured in the first embodiment, after Ar ions are implanted into the dielectric layer 104 under the same conditions as in the first embodiment, an MgO protective layer 105 (film thickness: 0.5 μm) is formed. A plasma display panel (3) was prepared by implanting Ar ions into the MgO protective layer 105 (film thickness: 0.5 μm) under the same conditions as in the second embodiment. The other components are the same as those described in the first embodiment, and a description thereof is omitted here.
[0047]
When the panel (3) was examined for change in light emission luminance over time in the same manner as in Embodiment 1, the luminance after 5000 hours was 93% of the initial value, which is superior to the panels (1) and (2). It was. This is probably because the number of Ar atoms released into the discharge space 110 over time was larger than in the panels (1) and (2).
[0048]
(Embodiment 4)
In the plasma display panel 100 manufactured in the first embodiment, a substrate on the display surface side is formed without implanting Ar ions into the dielectric layer 104, and the address electrodes are formed on the glass substrate 106 on the back surface side as shown in FIG. After forming 107 and the base dielectric layer 301, a plasma display panel (4) was produced in which Ar ions were implanted into the base dielectric layer 301 in the same manner as in the first embodiment. When the Ar atom density in the film thickness direction in the base dielectric layer 301 was evaluated by SIMS, the distribution shape shown in FIG. However, the depth at the peak value of the Ag atom density was approximately 1 nm to 2000 nm, and the peak value was in the range of 2 × 1020 / cm3 to 2 × 1021 / cm3. The other components are the same as those described in the first embodiment, and a description thereof is omitted here.
[0049]
When this panel (4) was examined for change in light emission luminance over time in the same manner as in the first embodiment, the luminance after 5000 hours was 85% of the initial value, and the comparison panel (A) into which nothing was injected was used. It turned out to be superior.
[0050]
Further, when the plasma display panel was configured using the back side substrate at this time and the display side substrate obtained by injecting Ar into the dielectric layer 104 produced in the first embodiment, and the time-dependent change in emission luminance was examined, The luminance after 5000 hours was 93% of the initial value.
[0051]
Further, when the plasma display panel was configured using the back side substrate at this time and the display side substrate obtained by injecting Ar into the protective layer 105 produced in the second embodiment, the time-dependent change in emission luminance was examined. The luminance after time was 88% of the initial value.
[0052]
Further, when the plasma display panel was configured using the back side substrate at this time and the display side substrate obtained by injecting Ar into the protective layer 105 produced in the third embodiment, the time-dependent change in emission luminance was examined. The luminance after time was 95% of the initial value.
[0053]
The impurity atoms implanted into the underlying dielectric layer 301 may be those that give a Penning effect to the discharge gas. When a mixed gas of Ne—Xe is used as the discharge gas, He is used in addition to Ar. It may be used, and Ar and He may be injected simultaneously. When He—Xe is used as the discharge gas, Ne is preferable as the impurity atom implanted into the base dielectric layer 301.
[0054]
(Embodiment 5)
In the plasma display panel 100 manufactured in the first embodiment, a substrate on the display surface side is formed without implanting Ar ions into the dielectric layer 104, and the partition wall 108 is formed on the glass substrate 106 on the back surface side as shown in FIG. After forming the plasma display panel (5), Ar ions were implanted into the barrier ribs 108 in the same manner as in the first embodiment. When the Ar atom density in the film thickness direction in the partition wall 108 was evaluated by SIMS, the distribution shape shown in FIG. However, the depth at the peak value of the Ag atom density was approximately 1 nm to 2000 nm, and the peak value was in the range of 2 × 1020 / cm3 to 2 × 1021 / cm3. The other components are the same as those described in the first embodiment, and a description thereof is omitted here.
[0055]
When this panel (5) was examined for change in emission luminance over time in the same manner as in the first embodiment, the luminance after 5000 hours was 90% of the initial value, and the comparison panel (A) into which nothing was injected was used. It turned out to be superior.
[0056]
Further, when the plasma display panel was configured using the back side substrate at this time and the display side substrate obtained by injecting Ar into the dielectric layer 104 manufactured in the first embodiment, the time-dependent change in the emission luminance was examined. The luminance after time was 95% of the initial value.
[0057]
Further, when the plasma display panel was configured using the back side substrate at this time and the display side substrate obtained by injecting Ar into the protective layer 105 produced in the second embodiment, the time-dependent change in emission luminance was examined. The luminance after the time was 92% of the initial value.
[0058]
Further, when the plasma display panel was configured using the back side substrate at this time and the display side substrate obtained by injecting Ar into the protective layer 105 produced in the third embodiment, the time-dependent change in emission luminance was examined. The luminance after time was 97% of the initial value.
[0059]
The impurity atoms implanted into the barrier ribs 108 may be any atoms that give a Penning effect to the discharge gas. When a mixed gas of Ne—Xe is used as the discharge gas, He is used in addition to Ar. Alternatively, Ar and He may be implanted simultaneously. In the case where He—Xe is used as the discharge gas, Ne is preferable as the impurity atom implanted into the partition wall 108.
[0060]
(Embodiment 6)
In the plasma display panel 100 manufactured in the first embodiment, a substrate on the display surface side is formed without implanting Ar ions into the dielectric layer 104, and the underlying dielectric is formed on the glass substrate 106 on the back side as shown in the figure. A plasma display panel (6) was produced in which Ar ions were implanted into the layer 111 and the barrier ribs 108 in the same manner as in the first embodiment. The other components are the same as those described in the first embodiment, and a description thereof is omitted here.
[0061]
When the panel (6) was examined for change in emission luminance over time in the same manner as in Embodiment 1, the luminance after 5000 hours was 93% of the initial value, which was superior to the panels (4) and (5). Turned out to be. This is probably because the number of Ar atoms released into the discharge space 110 over time was larger than those in the panels (4) and (5).
[0062]
Further, when the plasma display panel was configured using the back side substrate at this time and the display side substrate obtained by injecting Ar into the dielectric layer 104 manufactured in the first embodiment, the time-dependent change in the emission luminance was examined. The luminance after time was 97% of the initial value.
[0063]
Further, when the plasma display panel was configured using the back side substrate at this time and the display side substrate obtained by injecting Ar into the protective layer 105 produced in the second embodiment, the time-dependent change in emission luminance was examined. The luminance after time was 95% of the initial value.
[0064]
Further, when the plasma display panel was configured using the back side substrate at this time and the display side substrate obtained by injecting Ar into the protective layer 105 produced in the third embodiment, the time-dependent change in emission luminance was examined. The luminance after time was 98 to 99% of the initial value.
[0065]
(Embodiment 7)
In the plasma display panel 100 manufactured in the first embodiment, a panel (7) in which SiH 4 was mixed with the filled discharge gas in a volume ratio of 10 ppm to 1% was manufactured. The other components are the same as those described in the first embodiment, and a description thereof is omitted here.
[0066]
When this panel (7) was examined for change in light emission luminance over time in the same manner as in the first embodiment, the luminance after 5000 hours was 95% of the initial value, and the panel (1) not mixed with SiH4. It turned out to be superior to. This cause is considered as follows.
[0067]
Over time, H2O and CO2 adsorbed on the surface of the protective layer 105 and the phosphor layers 109R, G, and B, and the hydrocarbon gas contained in the dielectric layer 104, the base dielectric layer 301, and the barrier ribs 108 are gradually discharged into the discharge space. When these impure gases are discharged into the discharge gas and mixed into the discharge gas, the brightness of the panel is deteriorated. However, in the plasma of the discharge space 110, impure gas molecules float in the discharge space 110 by mixing with a gas that reacts with these gases and has a function of changing to a solid material with higher binding energy and not gasified. Can be suppressed and deterioration of the luminance of the panel can be prevented. Atoms that bind to atoms (oxygen atoms, carbon atoms) that constitute impure gases such as H2O, CO2, and hydrocarbons with strong bond energy are Si and Ge (Si-C bond, Si-O bond, Ge-C). Bond, Ge—O bond is formed). Accordingly, the reason why the panel (7) mixed with SiH4 is less deteriorated in luminance than the panel (1) not mixed is that SiH4 and impure gas molecules are dissociated in the discharge space 110, and Si—O bonds and Si— This is probably because C bonds were formed and adhered to the phosphor layers 109R, G, B and the protective layer 105 surface.
[0068]
As gas to be mixed into the discharge gas, in addition to SiH4, Si2H6, Si3H8, SiF4, SiH2F2, SiH3F, SiHF3, SiCl4, SiHCl3, SiH2Cl2, SiH3Cl, GeH4, Ge2H6, GeF4, Ge2F6, GeH3F, GeH3F2, GeH3F2, GeH3F, etc. are used. May be.
[0069]
In the first to seventh embodiments, not only one kind of Ar atoms but also different kinds of atoms may be mixed as impurity atoms implanted into each part. In addition, the types of impurity atoms contained in the dielectric layer 104, the protective layer 105, the base dielectric layer 301, and the partition wall 108 may be different, or different types of atoms may be included by changing the mixing ratio. .
[0070]
As can be seen from the above, the plasma display panel of the present invention does not change in luminance with time and is highly stable in operation.
[0071]
【The invention's effect】
According to the present invention, it is possible to provide a plasma display panel that does not change in luminance with time and has excellent stability and long life.
[Brief description of the drawings]
FIG. 1 is a cross-sectional perspective view schematically showing a configuration of a plasma display panel in an embodiment of the present invention. FIG. 2 is a diagram illustrating a dielectric layer, a protective layer, a base dielectric layer, or a partition used in an embodiment of the present invention. FIG. 3 is a cross-sectional perspective view schematically showing the structure of a plasma display panel in another embodiment of the present invention. FIG. 4 is a schematic view showing the structure of a conventional plasma display panel. Cross-sectional view [Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 Plasma display panel 101 Display surface side glass substrate 102 Display electrode 103 Bus electrode 104 Dielectric layer 105 Protective layer 106 Back side glass substrate 107 Address electrode 108 Partition 109R Phosphor layer (red)
109G phosphor layer (green)
109B phosphor layer (blue)
110 Discharge space 301 Base dielectric layer

Claims (1)

  A dielectric layer made of glass containing bismuth oxide or phosphorus oxide covering a conductive electrode and at least one of a pair of substrates facing each other through a discharge space, and a protective layer made of a metal oxide A plasma display panel having a structure in which layers are sequentially laminated, and a region having a high Ar atom density exists on the protective layer side of the dielectric layer.

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