JP2004087356A - Plasma display panel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma display panel with high image quality and high reliability. <P>SOLUTION: The plasma display panel is so constituted that a plurality of display electrodes 4 covered with a dielectric layer 5 are formed. At the same time, in a substrate, a protection layer 16 is formed on the dielectric layer 5, and in another substrate, a plurality of data electrodes 10 are formed so as to cross with the display electrodes 4. These substrates are arranged opposingly and, by this, discharge cells are formed at intersection parts of the display electrode 4 and the data electrode 10. The protection layer 16 is constituted of a first protection layer 16a and a second protection layer 16b of which the secondary electron emission coefficient is lower than the first protection layer 16a. The second protection layer 16b is formed so as to surround each discharge cell, and at the same time, it is formed in the width (b) narrower than the width (a) of a region 17 in the region 17 between the adjacent display electrodes 4. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a plasma display panel and a method for manufacturing the same.
[0002]
[Prior art]
2. Description of the Related Art A plasma display panel is a display that displays an image by exciting a phosphor with ultraviolet rays generated by gas discharge. 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 in that it is 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 excellent in terms of luminance and luminous efficiency.
[0003]
FIG. 9 shows a conventional AC plasma display panel. As shown in FIG. 9, on a transparent front substrate 1 made of glass, stripe-shaped display electrodes 4 forming pairs of scanning electrodes 2 and sustain electrodes 3 arranged in parallel with a discharge gap therebetween. Are formed. The scanning electrode 2 includes a transparent electrode 2a and a bus electrode 2b made of metal electrically connected to the transparent electrode 2a. The sustain electrode 3 is electrically connected to the transparent electrode 3a and the transparent electrode 3a. And a bus electrode 3b made of metal. A dielectric layer 5 made of low-melting glass is formed on the front substrate 1 so as to cover the plurality of display electrodes 4, and a magnesium oxide (MgO) film 6 is formed on the dielectric layer 5. Thus, the front panel 7 is configured.
[0004]
A plurality of striped data electrodes 10 covered with a base dielectric layer 9 are formed on a rear substrate 8 opposed to the front substrate 1 so as to intersect the display electrodes 4 at right angles. . A plurality of stripe-shaped partitions 11 are arranged on the underlying dielectric layer 9 between the data electrodes 10 in parallel with the data electrodes 10, and the phosphor layers 12 are disposed on the side surfaces of the partitions 11 and the surface of the underlying dielectric layer 9. Are provided, and thereby, the back panel 13 is configured.
[0005]
The front panel 7 and the back panel 13 are opposed to each other with a minute discharge space 14 interposed therebetween so that the display electrode 4 and the data electrode 10 are orthogonal to each other. Is filled with a mixed gas of neon (Ne) and xenon (Xe) at a pressure of about 66.5 kPa (500 Torr) as a discharge gas. Further, the discharge space 14 is divided into a plurality of sections by the partition walls 11, so that discharge cells are provided at intersections of the display electrodes 4 and the data electrodes 10, and each of the discharge cells has red, green, and blue. The phosphor layers 12 are sequentially arranged one by one so that
[0006]
In such a plasma display panel, an AC voltage of several tens of kHz to several hundreds of kHz is applied between the scanning electrode 2 and the sustaining electrode 3 to generate a discharge in the discharge space 14 and emit from the excited Xe atoms. The display operation is performed by generating visible light by exciting the phosphor layer 12 with the ultraviolet light.
[0007]
[Problems to be solved by the invention]
In recent years, the plasma display panel has a problem that erroneous discharge is apt to occur because the interval between the adjacent display electrodes 4 is narrowed due to the progress of high definition.
[0008]
A method for solving this problem is described in, for example, JP-A-9-129140. This is because the surface of the dielectric layer 5 except for the surface of the dielectric layer 5 between the adjacent display electrodes 4 is covered with the magnesium oxide film 6, and the region where the magnesium oxide film 6 is not formed, that is, the region where the magnesium oxide film 6 is not formed, Thus, erroneous discharge is prevented between the display electrodes 4.
[0009]
However, in this configuration, an electric field of a predetermined intensity is also applied to the region between the adjacent display electrodes 4 by the voltage applied to each electrode, so that the dielectric layer 5 in the region not covered with the magnesium oxide film 6 is applied. However, there is a problem in that the ions generated by the discharge collide with each other and are sputtered to cause dielectric breakdown. Further, if there is a gap between the tip of the partition 11 and the magnesium oxide film 6 where electric charges can be mutually transferred, secondary electrons are actively supplied from the magnesium oxide film 6 also from the vicinity of the tip of the partition 11. In addition, there is a problem that erroneous discharge occurs between adjacent discharge cells via the partition wall 11.
[0010]
The publication also discloses that a magnesium oxide film is formed except for a region facing the tip of the partition 11, but in this case, the dielectric material is formed in a region facing the tip of the partition 11. There was a problem that the layer 5 was sputtered and the panel life was shortened.
[0011]
The present invention has been made to solve such a problem, and has as its object to provide a highly reliable plasma display panel with high image quality.
[0012]
[Means for Solving the Problems]
In order to achieve this object, the present invention forms a plurality of display electrodes covered with a dielectric layer and a substrate having a protective layer formed on the dielectric layer, and a plurality of display electrodes intersecting the display electrodes. A plasma display panel in which discharge cells are formed at intersections of the display electrodes and the data electrodes by disposing a substrate on which data electrodes are formed to face each other, wherein the protective layer is a first protective layer and a first protective layer. A second protective layer having a lower secondary electron emission coefficient than that of the first protective layer. The second protective layer is formed so as to surround each discharge cell and is formed in a region between adjacent display electrodes. A plasma display panel formed with a width smaller than the width of the plasma display panel.
[0013]
Further, according to the present invention, after a plurality of display electrodes are formed on a substrate and a dielectric layer is formed so as to cover the display electrodes, a first protective layer and a metal having a predetermined pattern are formed on the dielectric layer. Forming a second protective layer having a lower secondary electron emission coefficient than the first protective layer by oxidizing the metal layer by heat treatment. It is a manufacturing method.
[0014]
Further, according to the present invention, after a plurality of display electrodes are formed on a substrate and a dielectric layer is formed so as to cover the display electrodes, the softening point temperature is lower on the dielectric layer than on the dielectric layer. After forming a low softening point dielectric layer of a predetermined pattern shape, and then forming a protective material layer so as to cover the dielectric layer and the low softening point dielectric layer, the low softening point dielectric layer A method for manufacturing a plasma display panel, comprising forming a protective layer by heat-treating the substrate at a temperature equal to or higher than the softening point and lower than the softening point of the dielectric layer.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a plasma display panel according to an embodiment of the present invention will be described with reference to FIGS. The same parts as those shown in FIG. 9 are denoted by the same reference numerals.
[0016]
FIG. 1 is a sectional view of a plasma display panel according to a first embodiment of the present invention, and FIG. 2 is a schematic plan view showing the relationship between the pattern shape of a protective layer and various electrodes.
[0017]
In the plasma display panel of the present embodiment, as shown in FIG. 1, a front panel 15 and a back panel 13 are arranged opposite to each other so as to form a discharge space 14, and neon (discharge gas) A gas mixture of Ne) and xenon (Xe) is filled at a pressure of about 66.5 kPa (500 Torr).
[0018]
The front panel 15 has the following configuration. That is, on the transparent glass front substrate 1, a plurality of stripe-shaped display electrodes 4 are formed, which are paired with scan electrodes and sustain electrodes arranged in parallel with a discharge gap therebetween. A dielectric layer 5 made of low-melting glass is formed so as to cover the electrode 4, and a protective layer 16 is formed on the dielectric layer 5. The protection layer 16 includes a first protection layer 16a formed on the entire surface of the dielectric layer 5, and a second protection layer 16b formed in a predetermined pattern on the first protection layer 16a. ing. The scan electrode and the sustain electrode constituting the display electrode 4 have the same configuration as the scan electrode 2 and the sustain electrode 3 shown in FIG. 9, and as shown in FIG. 9, the scan electrode 2 is the same as the transparent electrode 2a. The bus electrode 2b is electrically connected to the transparent electrode 2a, and the sustain electrode 3 is comprised of a transparent electrode 3a and a bus electrode 3b electrically connected to the transparent electrode 3a. The transparent electrodes 2a and 3a are made of indium tin oxide (ITO) or tin oxide (SnO). ₂ ), And the bus electrodes 2b and 3b are made of a silver (Ag) thick film, an aluminum (Al) thin film, or a chromium / copper / chromium (Cr / Cu / Cr) laminated thin film.
[0019]
The back panel 13 has the same configuration as the conventional one shown in FIG. That is, a plurality of stripe-shaped data electrodes 10 covered with a base dielectric layer 9 are formed on a rear substrate 8 opposed to the front substrate 1 so as to intersect the display electrodes 4 at right angles. . A plurality of stripe-shaped partitions 11 are arranged on the underlying dielectric layer 9 between the data electrodes 10 in parallel with the data electrodes 10, and the phosphor layers 12 are disposed on the side surfaces of the partitions 11 and the surface of the underlying dielectric layer 9. Is provided.
[0020]
A discharge cell is formed at a portion where the display electrode 4 and the data electrode 10 intersect. In each of the discharge cells, a phosphor layer 12 is sequentially arranged for each color so as to be red, green and blue. An image is displayed by controlling the discharge in each discharge cell.
[0021]
Next, the pattern shape of the protective layer 16 formed on the dielectric layer 5 of the front panel 15 will be described with reference to FIG. FIG. 2 shows the pattern shape of the protective layer 16 when the front panel 15 is viewed from the rear substrate 8 side so that the positional relationship among the scan electrode 2, the sustain electrode 3, and the data electrode 10 can be understood. As shown in FIG. 2, the protective layer 16 includes a first protective layer 16a and a second protective layer 16b, and the secondary electron emission coefficient of the second protective layer 16b is equal to that of the first protective layer 16a. Is lower than the secondary electron emission coefficient. The second protective layer 16b is formed so as to surround each discharge cell, and has a width b smaller than the width a of the region 17 in the region 17 between the adjacent display electrodes 4. As described above, the region where the second protective layer 16b is formed includes the region corresponding to the position where the partition wall 11 is formed and the region between the adjacent display electrodes 4. The first protective layer 16a is made of MgO having a high secondary electron emission coefficient, and the second protective layer 16b is made of aluminum (Al), silicon (Si), zinc (Zn), calcium (Ca), nickel ( Ni), iron (Fe), chromium (Cr) and titanium (Ti).
[0022]
Next, a method for manufacturing the plasma display panel of the present embodiment will be described. First, a method for manufacturing the front panel 15 will be described with reference to FIG.
[0023]
A transparent electrode made of a transparent conductive material such as ITO or tin oxide is formed on a front substrate 1 made of glass by a sputtering method, etching, or the like, and an Ag thick film, an Al thin film, or Cr / Cu / Cr is formed on the transparent electrode. By sequentially laminating bus electrodes such as a laminated thin film, a display electrode 4 composed of the scan electrode 2 and the sustain electrode 3 is formed as shown in FIG.
[0024]
Next, as shown in FIG. 3B, lead oxide (PbO) or bismuth oxide (Bi ₂ O ₃ ) Or phosphorus oxide (PO ₄ After forming a dielectric layer 5 made of a low-melting glass mainly composed of) by screen printing, a first protective layer 16a made of MgO is formed on the entire surface of the dielectric layer 5 as shown in FIG. And formed by an electron beam evaporation method or a sputtering method.
[0025]
Next, a second protective layer 16b is formed. That is, by forming aluminum (Al) on the first protective layer 16a by an electron beam evaporation method or a sputtering method via a mask having an opening corresponding to a position where the second protective layer 16b is formed, FIG. As shown in FIG. 3D, a metal layer 18 having a predetermined pattern shape made of Al is formed on the first protective layer 16a. Subsequently, the metal layer 18 is oxidized by heating at 450 to 550 ° C. for 1 to 30 minutes in air or an oxygen atmosphere to oxidize the metal layer 18, thereby forming the first protective layer as shown in FIG. A second protective layer 16b having a predetermined pattern shape is formed on 16a. The metal used when forming the metal layer 18 is, in addition to Al, silicon (Si), zinc (Zn), calcium (Ca), nickel (Ni), iron (Fe), chromium (Cr), or titanium (Ti). ).
[0026]
On the other hand, the back panel 13 forms a data electrode 10 composed of an Ag thick film, an Al thin film, or a Cr / Cu / Cr laminated thin film on a glass back substrate 8, and then forms lead oxide (PbO) or bismuth oxide (Bi). ₂ O ₃ ) Or phosphorus oxide (PO ₄ The base dielectric layer 9 made of low-melting glass whose main component is a) is formed by screen printing. After that, partition walls 11 mainly composed of glass are formed at a predetermined pitch, and a phosphor layer 12 made of a red phosphor, a green phosphor, and a blue phosphor is formed in each space sandwiched by the partition walls 11.
[0027]
Next, the front panel 15 and the back panel 13 manufactured in this manner are bonded together using sealing glass, and the inside of the discharge space 14 is 1 × 10 ^-4 After evacuating to Pa, for example, a mixed gas of neon gas and xenon gas is set to 95% and 5% by volume, respectively, and the pressure is set to 66.5 kPa (500 Torr).
[0028]
Next, a driving method of the plasma display panel will be described with reference to FIGS.
[0029]
FIG. 4 shows an electrode arrangement diagram of this plasma display panel. As shown in FIG. 4, the electrodes have an m × n matrix configuration, and m columns of data electrodes D are arranged in the column direction. ₁ ~ D _m Are arranged, and n rows of scan electrodes SCN are arranged in the row direction. ₁ ~ SCN _n And sustain electrode SUS ₁ ~ SUS _n Are arranged. Then, the scanning electrode SCN _i And sustain electrode SUS _i (I = 1 to n) and data electrode D _j A discharge cell is formed at each intersection with (j = 1 to m), and m × n discharge cells are formed in the panel.
[0030]
When performing image display, one field period is composed of a plurality of subfields weighted by the number of sustain pulses having a predetermined light emission intensity, and a subfield used for display is selected from the subfields constituting one field period. Thus, gradation display is performed by displaying a predetermined luminance. Each subfield has a writing period in which charges are formed in the discharge cells in accordance with display data, a sustain period in which sustain discharge is performed in the discharge cells in which charges are formed in the writing period, and an erasing period in which the sustain discharge is stopped. . One of the subfields constituting one field period has an initialization period for resetting the charges in the discharge cells before the writing period. Note that the initialization period may be provided for all subfields.
[0031]
An example of a driving operation of the plasma display panel will be described with reference to a driving waveform diagram in FIG. FIG. 5 shows a first subfield having an initializing period, a writing period, a sustaining period, and an erasing period, and a second subfield following the first subfield. The waveform of a scan electrode is a waveform applied to a certain scan electrode. Wherein the waveform of the sustain electrode represents a waveform applied to all the sustain electrodes, and the waveform of the data electrode represents a waveform applied to the data electrodes according to display data.
[0032]
First, in the first subfield, the scan electrode SCN ₁ ~ SCN _n To initialize the wall charges in the discharge cells.
[0033]
Next, in the writing period, the scan electrodes SCN of the first row ₁ Scan pulse Pc is applied to a predetermined data electrode D to which display data is to be written. _j (J = 1 to m) by applying a write pulse Pa to a predetermined data electrode D _j And the scanning electrode SCN in the first row ₁ And a write discharge (address discharge) occurs between the scan electrodes SCN and the address discharge as a trigger. ₁ And sustain electrode SUS ₁ A wall charge is accumulated on the surface of the protective layer 16 and a write operation (address operation) of the first row is performed. Such an address operation is sequentially performed on each row, and when the address operation on the n-th row is completed, display data for one screen is written.
[0034]
Next, in the sustain period, all data electrodes D ₁ ~ D _m Is grounded and all scan electrodes SCN ₁ ~ SCN _n , A sustain pulse Ps is applied to all the sustain electrodes SUS. ₁ ~ SUS _n By applying the sustain pulse Ps to the discharge cells that have been subjected to the address operation during the writing period, the light emission of the sustain discharge is continuously performed. An image is displayed.
[0035]
Thereafter, in the erasing period, a discharge is generated by applying the narrow erasing pulse Pe, and the wall charges disappear, so that the erasing operation is performed.
[0036]
In the next second subfield, a series of operations similar to the operations in the writing period, the sustaining period, and the erasing period in the first subfield are performed, and the same operation is continued until the last subfield of one field. As a result, an image is displayed.
[0037]
In the panel of the present embodiment, as described above, the second protective layer 16b is formed in the region 17 between the adjacent display electrodes 4 with a width b smaller than the width a of the region. That is, the first protective layer 16a is formed to extend widely to the region 17 between the adjacent display electrodes 4 beyond the outer ends of the scan electrodes 2 and the sustain electrodes 3 constituting the display electrodes 4 in each discharge cell. I have. Since the sustain discharge generated between the scan electrode 2 and the sustain electrode 3 spreads to the region where the first protective layer 16a is formed, the region where the sustain discharge occurs is widened to obtain a high-luminance display. Can be.
[0038]
In addition, since the second protective layer 16b has a low secondary electron emission coefficient, secondary electrons are less likely to be generated in the region where the second protective layer 16b is formed. Since the second protective layer 16b is formed so as to surround each discharge cell, even if the sustain discharge spreads to the formation region of the first protective layer 16a in the discharge cell, the sustain discharge does not spread to the adjacent region. The occurrence of erroneous discharge by spreading to the discharge cells is prevented. Further, since the dielectric layer 5 is covered with the protective layer 16 including the first protective layer 16a and the second protective layer 16b, the dielectric layer 5 is not sputtered by the discharge, and the dielectric breakdown is prevented. It is possible to prevent the occurrence of such a panel and obtain a long-life panel.
[0039]
Next, specific examples will be described. As an embodiment of the present invention, a panel of a 42 inch class XGA display (the number of pixels is 1024 × 768) is manufactured, the pitch between the display electrodes 4 is 675 μm, the pitch between the partition walls 11 is 300 μm, and the thickness of the dielectric layer 5 is 35 μm, the thickness of each of the protective layers 16 a and 16 b is 0.8 μm, the gap between the scan electrode 2 and the sustain electrode 3 constituting the display electrode 4 is 80 μm, the distance between adjacent display electrodes 4 is 200 μm, Is 120 μm, and the size of the first protective layer 16a provided in one discharge cell is 580 μm × 210 μm. The first protective layer 16a is formed of magnesium oxide (MgO), and the second protective layer 16b is formed of aluminum oxide (Al ₂ O ₃ ).
[0040]
As a comparative example, a panel (Comparative Example 1) in which an MgO film was formed on the entire surface of the dielectric layer 5 and a region facing the partition 11 on the dielectric layer 5 and a region between the adjacent display electrodes 4 were excluded. Thus, a panel (Comparative Example 2) on which an MgO film was formed was manufactured. The pattern shape of the MgO film in the panel of Comparative Example 2 will be described with reference to FIG. 2. The width b of the region of the second protective layer 16 b in FIG. 2 is the same as the width a of the region 17 between the adjacent display electrodes 4. The MgO film is formed in the region of the first protective layer 16a, and nothing is formed in the region of the second protective layer 16b, so that the surface of the dielectric layer 5 is exposed.
[0041]
First, the panels of Example of the present invention and Comparative Example 1 were driven with the driving waveforms shown in FIG. At this time, the voltage values are set as Va = 400 V, Vb = −90 V, Vc = −10 V, Vd = 140 V, Ve = 150 V, Vdat = 67 V, and erroneous discharge (crosstalk) by changing the voltage Vs of the sustain pulse Ps. Voltage value of Vs at which ₁ Was measured. As a result, in the panel of Comparative Example 1, V ₁ = 200 V, whereas the panel of the embodiment has V ₁ = 205V. That is, the panel of the example has a configuration in which crosstalk is less likely to occur than the panel of comparative example 1, and has the effect of suppressing the occurrence of crosstalk.
[0042]
This is explained as follows. That is, in the case of Comparative Example 1 in which the MgO film is formed on the entire surface of the dielectric layer 5, when the discharge reaches the region between the adjacent display electrodes 4 or the region facing the partition 11, the MgO film in those regions is Secondary electrons are emitted by collision of ions generated by the discharge, so that the scale of the discharge is enlarged and crosstalk occurs. On the other hand, in the case of the embodiment of the present invention, since the second protective layer 16b having a low secondary electron emission coefficient is present, secondary electrons are hardly generated in the boundary region between the adjacent discharge cells, so that the discharge is attenuated. Erroneous discharge can be prevented.
[0043]
Next, for the panels of Example and Comparative Example 2, the number of sustaining pulses was set to 11 times that of the conventional panel, and the life of the panel of Example was compared with that of the panel of Example. The life was extended 1.2 times as compared with the panel of Example 2. This is because, in the panel of Comparative Example 2, the dielectric layer 5 in the region not covered with the MgO film is sputtered, and the impurity gas concentration in the discharge space increases and the discharge becomes unstable. This is because the dielectric layer 5 is covered with the protective layer 16, so that the dielectric layer 5 is not sputtered and the discharge is stabilized. Further, in the panel of the example, the spread of the discharge in each discharge cell was larger than that of the panel of the comparative example 2, and high emission luminance could be obtained.
[0044]
Similar effects were obtained not only on XGA panels but also on SXGA panels having different electrode widths and electrode intervals.
[0045]
In the above embodiment, the first protective layer 16a made of MgO is formed on the entire surface of the dielectric layer 5, but the first protective layer 16a having a predetermined pattern shape is formed on the dielectric layer 5 by using a mask. The layer 16a may be formed, and the second protective layer 16b may be formed in a region where the first protective layer 16a is not formed. Further, the second protective layer 16b may be the same as a normal MgO material but having a different crystallinity and a lower secondary electron emission coefficient.
[0046]
Next, a plasma display panel according to a second embodiment of the present invention will be described with reference to the drawings.
[0047]
The plasma display panel shown in FIG. 6 is configured by arranging a front panel 19 and a back panel 13 facing each other, and the configuration of the back panel 13 is the same as the panel shown in FIG. The front panel 19 has the following configuration. That is, on the front substrate 1, a plurality of stripe-shaped display electrodes 4 forming pairs of scan electrodes and sustain electrodes arranged in parallel with a discharge gap therebetween are formed, and a low melting point glass is formed so as to cover the display electrodes 4. Is formed. A low softening point dielectric layer 20 having a lattice pattern is formed on the dielectric layer 5, and a protective layer 21 is formed so as to cover the dielectric layer 5 and the low softening point dielectric layer 20. . The protective layer 21 includes a first protective layer 21a formed directly on the dielectric layer 5 and a second protective layer 21b covering the low softening point dielectric layer 20. Further, a discharge cell is formed at the intersection of the display electrode 4 and the data electrode 10. The low softening point dielectric layer 20 is formed so as to surround each discharge cell.
[0048]
FIG. 7 shows a pattern shape of the protective layer 21 when the front panel 19 is viewed from the back substrate 8 side, and the protective layer 21 includes a first protective layer 21a and a second protective layer 21b. The secondary electron emission coefficient of the second protective layer 21b is lower than the secondary electron emission coefficient of the first protective layer 21a. The second protective layer 21b is formed so as to surround each discharge cell, and has a width b smaller than the width a of the area in the area 17 between the adjacent display electrodes 4. As described above, the area where the second protective layer 21b is formed includes the area corresponding to the position where the partition wall 11 is formed and the area between the adjacent display electrodes 4.
[0049]
Next, a method for manufacturing the front panel 19 will be described with reference to FIG.
[0050]
First, a transparent electrode made of a transparent conductive material such as ITO or tin oxide is formed on a front substrate 1 made of glass by a sputtering method, etching, or the like, and an Ag thick film, an Al thin film, or a Cr / Cu / By sequentially laminating bus electrodes such as a Cr laminated thin film, a display electrode 4 including a scan electrode 2 and a sustain electrode 3 is formed on the front substrate 1 as shown in FIG.
[0051]
Thereafter, as shown in FIG. 8B, lead oxide (PbO) or bismuth oxide (Bi ₂ O ₃ ) Or phosphorus oxide (PO ₄ The dielectric layer 5 made of low-melting glass whose main component is a) is formed by screen printing.
[0052]
Next, as shown in FIG. 8C, lead oxide (PbO) or bismuth oxide (Bi oxide) is formed on the dielectric layer 5 in a region where the second protective layer 21b is to be formed. ₂ O ₃ ) Or phosphorus oxide (PO ₄ The low softening point dielectric layer 20 made of a low melting point glass whose main component is a) is formed by screen printing. Here, the low softening point dielectric layer 20 is formed using a material whose softening point temperature is lower than the softening point temperature of the dielectric layer 5, and is formed at the intersection of the display electrode 4 and the data electrode 10. Formed in a predetermined pattern so as to surround each discharge cell to be formed.
[0053]
Subsequently, as shown in FIG. 8D, a protective layer 22 made of MgO is formed by an electron beam evaporation method or a sputtering method so as to cover the dielectric layer 5 and the low softening point dielectric layer 20.
[0054]
Thereafter, the front surface on which the dielectric layer 5, the low softening point dielectric layer 20, the protective layer 22, and the like are formed at a temperature equal to or higher than the softening point temperature of the low softening point dielectric layer 20 and lower than the softening point temperature of the dielectric layer 5 By subjecting the substrate 1 to a heat treatment, a first protective layer 21a and a second protective layer 21b are formed on the dielectric layer 5 as shown in FIG. That is, since the low softening point dielectric layer 20 is softened by the heat treatment, the crystallinity of the protective layer 22 covering the low softening point dielectric layer 20 deteriorates. As a result, in the region where the crystallinity is deteriorated, the secondary electron emission coefficient decreases, so that the second protective layer 21b having a low secondary electron emission coefficient is formed. The protective layer 22 covering the dielectric layer 5 becomes a first protective layer 21a having a high secondary electron emission coefficient.
[0055]
The front panel 19 manufactured in this manner and the back panel 13 manufactured in the same manner as described above are bonded together using sealing glass, and a mixed gas of neon gas and xenon gas is set to 95% and 5% by volume, respectively, and the pressure is adjusted. Is sealed in the panel at 66.5 kPa (500 Torr) to obtain a plasma display panel.
[0056]
The protective layer 21 of the plasma display panel according to the second embodiment includes a first protective layer 21a and a second protective layer 21b having a lower secondary electron emission coefficient than the first protective layer 21a. It is formed in the same pattern shape as the protective layer 16 of the plasma display panel according to the first embodiment. Therefore, according to the plasma display panel according to the second embodiment, the same effect as that of the plasma display panel according to the first embodiment can be obtained.
[0057]
【The invention's effect】
As described above, according to the present invention, erroneous discharge between adjacent discharge cells can be prevented from occurring, and the dielectric layer can be prevented from being sputtered, so that a plasma display panel with high image quality and high reliability can be obtained. it can.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a main part of a plasma display panel according to a first embodiment of the present invention.
FIG. 2 is a schematic plan view showing the relationship between the pattern shape of a protective layer and the electrodes of the plasma display panel.
FIGS. 3A to 3E are cross-sectional views for explaining a method of manufacturing the plasma display panel.
FIG. 4 is an electrode arrangement diagram of the plasma display panel.
FIG. 5 is a driving waveform diagram of the plasma display panel.
FIG. 6 is a sectional view showing a main part of a plasma display panel according to a second embodiment of the present invention.
FIG. 7 is a schematic plan view showing the positional relationship between the pattern shape of the protective layer and the electrodes of the plasma display panel.
FIGS. 8A to 8E are cross-sectional views illustrating a method of manufacturing the plasma display panel.
FIG. 9 is a perspective view showing a main part of a conventional plasma display panel.
[Explanation of symbols]
1 Front board
2 Scanning electrode
3 sustain electrode
4 Display electrode
5 Dielectric layer
8 Back substrate
9 Base dielectric layer
10 Data electrode
13 Back panel
14 Discharge space
15, 19 Front panel
16, 21, 22 protective layer
16a, 21a First protective layer
16b, 21b Second protective layer
18 Metal layer
20 Low softening point dielectric layer

Claims (3)

A substrate on which a plurality of display electrodes covered with a dielectric layer are formed and a protective layer is formed on the dielectric layer is opposed to a substrate on which a plurality of data electrodes are formed so as to intersect the display electrodes. A plasma display panel having a discharge cell formed at an intersection of the display electrode and the data electrode, wherein the protective layer has a first protective layer and a secondary electron emission coefficient higher than that of the first protective layer. And the second protective layer is formed so as to surround each discharge cell, and is formed in a region between adjacent display electrodes with a width smaller than the width of the region. A plasma display panel characterized by the following. After forming a plurality of display electrodes on a substrate and forming a dielectric layer so as to cover the display electrodes, a first protective layer and a metal layer having a predetermined pattern are formed on the dielectric layer. Forming a second protective layer having a lower secondary electron emission coefficient than the first protective layer by oxidizing the metal layer by heat treatment. After a plurality of display electrodes are formed on a substrate and a dielectric layer is formed so as to cover the display electrodes, a predetermined pattern shape having a softening point lower than that of the dielectric layer is formed on the dielectric layer. Forming a softening point dielectric layer, and then forming a protective material layer so as to cover the dielectric layer and the low softening point dielectric layer, and at a softening point temperature or higher of the low softening point dielectric layer and A method for manufacturing a plasma display panel, comprising forming a protective layer by heat-treating the substrate at a temperature lower than a softening point temperature of the dielectric layer.

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