JP2005228530A - Plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plasma display panel capable of stably reducing a discharge start voltage. <P>SOLUTION: This plasma display panel is so structured that a front glass substrate 210 and a back glass substrate 310 are arranged side by side with a space; dielectric layers 220 and 240 covering paired transparent electrodes 231 are formed on a surface of the front glass substrate 210 facing to the back substrate 310; and a plurality of discharge cells are scattered along the paired transparent electrodes 231. Recessed parts 220a and 240a each having a flat bottom surface part are respectively formed in surfaces of the dielectric layers 220 and 240 in the respective discharge cells; side surface parts 240c having at least a nearly facing relationship within a plurality of side surface parts existing between the openings of the recessed parts 240a and the bottom surface parts are tilted so as to increase the mutual facing distance as they approach the openings; and each transparent electrode 231 has a side surface part 220c having a plate-like form, present in the vicinity of the side surface part 240c and nearly parallel with the side surface part 240c. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a plasma display panel (hereinafter referred to as “PDP”), and more particularly to a technique for improving discharge efficiency.

In recent years, in display devices used in computers, televisions, and the like, PDPs have attracted attention as display devices that are large, thin, and lightweight.
This PDP is a display device that realizes color display by irradiating phosphors (red, green, and blue) with ultraviolet rays generated by plasma discharge in gas.

FIG. 11 is a schematic perspective view of a general AC type (AC type) PDP 1000.
The PDP 1000 is composed of a front plate 1200 and a back plate 1300 that are arranged with their main surfaces facing each other, and these are stacked and their outer peripheral edge portions are fused with sealing glass (not shown). It is sealed and a discharge space is formed inside.
The front plate 1200 includes a front glass substrate 1210, a display electrode 1230 including a transparent electrode 1231 and a bus electrode 1232, a dielectric layer 1240, and a protective layer 1250.

The front glass substrate 1210 is a material serving as a base for the front plate 1200, and display electrodes 1230 are formed on the front glass substrate 1210.
The display electrode 1230 and the front glass substrate 1210 are further covered with a dielectric layer 1240 and a protective layer 1250 made of magnesium oxide (MgO).
The back plate 1300 is formed on a wall surface of a back glass substrate 1310, an address electrode 1320, a dielectric layer 1330, a partition wall 1340, and a gap between adjacent partition walls 1340 (hereinafter referred to as “partition groove”). And phosphor layers 1350 corresponding to the respective colors of red, green and blue.

In the discharge space, for example, a discharge gas in which 5 to 30% xenon gas is mixed with neon gas is enclosed.
The vicinity of a region where a pair of adjacent display electrodes 1230 and one address electrode 1320 intersect with each other across the discharge space is a cell contributing to image display.
In the discharge space, vacuum ultraviolet rays are generated along with the discharge, and the phosphor layers 1350 corresponding to the respective colors of red, green, and blue are excited to emit light, thereby performing color display.

Such a PDP is a thin display with excellent display quality, but has a problem of low energy efficiency and high power consumption compared with a liquid crystal display which is a thin display of the same size. In order to improve energy efficiency, Instead of using the structure of a general front glass substrate 1200 as shown in FIG. 12, there is a PDP using a front plate 2200 having recesses on the surface of the dielectric layer 2241 and the surface of the protective layer 2250 as shown in FIG. . (For example, Patent Document 1)
More specifically, the dielectric layer 2240 of the PDP of Patent Document 1 gradually increases in thickness in a direction away from the cell center, and the thickness is constant at a position separated from the center by a predetermined distance or more. The strip-shaped display electrodes 2231 are disposed in symmetrical positions around the center of the cell in the portions where the thickness is changed.

Furthermore, a dielectric layer 2241 and a protective layer 2250 are laminated so as to cover the upper surface, and these laminates are formed along the shape of the lower layer, so that a concave portion is formed on the surface thereof.
The inner surface of the concave portion is constituted by two side surface portions 2250a, and these two side surface portions 2250a become main discharge surfaces at the start of discharge.

In other words, in the conventional maintenance period, the configuration is such that the surface discharge is performed between a pair of electrodes placed on the same plane, and the discharge can be performed in a state in which the pair of opposed electrodes are close to the counter discharge. ing.
Thereby, the homogenization of the electric field strength in the discharge space is promoted, the sustain discharge is performed more efficiently, and the discharge start voltage is reduced.
JP 2001-357784 A

However, as in Patent Document 1, a concave portion is provided on the surface of the dielectric layer, and when a PDP having a pair of electrodes formed along the inner surface of the concave portion is created and driven, the electric field strength in the discharge space is determined for each cell. Since there may be variations, the display device as a whole has a problem that the discharge efficiency cannot be increased and the effect of reducing the discharge start voltage is small.
The present invention has been made to solve such problems, and an object of the present invention is to provide a PDP that can stably reduce a discharge start voltage.

In order to achieve the above object, the present invention is characterized by the following.
(1) The first substrate and the second substrate are arranged side by side at a distance, and a pair of the first electrode and the second electrode are formed on the surface of the first substrate facing the second substrate, and A plasma display panel in which a dielectric layer covering a first electrode and a second electrode is formed, and a plurality of discharge cells are scattered along a pair of the first electrode and the second electrode. A concave portion having a flat bottom surface is formed on the surface of the dielectric layer, and a plurality of side surfaces existing between the opening of the concave portion and the bottom surface are in a substantially opposite relationship. The one side surface portion and the second side surface portion are inclined so that the interval between the first side surface portion and the second side surface portion increases as they approach the opening, and the first electrode is plate-shaped and exists in the vicinity of the first side surface portion. And the second electrode has a first inclined portion that is substantially parallel to the first side surface portion. A plate-like, present in the vicinity of the second side surface portion, characterized in that it has a second inclined portion having a relationship substantially parallel to the second side surface portion.

  (2) In the plasma display panel of (1), the bottom surface portion is in a substantially parallel relationship with the first substrate, and the first end portion of both end portions positioned in the tilt direction of the first tilt portion. Is located closer to the center of the recess than the other second end, and among the ends located in the tilt direction of the second inclined portion, the third end is more than the other fourth end. Located near the center of the recess, the first end and the third end are substantially equal in distance to the inner surface of the first substrate, and the second end and the fourth end are the first substrate. The distance from the inner surface is substantially equal, and the first electrode has a first extending portion extending substantially parallel to the bottom surface of the recess from the first end toward the side where the central portion is located. The second electrode has a second extending portion substantially parallel to the bottom surface portion of the concave portion from the third end portion toward the side having the central portion. It has been issued.

(3) In the plasma display panel of (2), the recess has a quadrangular frustum contour shape.
(4) In the plasma display panel of (2), each of the first electrode and the second electrode exists independently for each cell.
(5) In the plasma display panel according to (4), the first electrode has a third extension portion substantially parallel to the surface of the dielectric layer in a direction opposite to the side where the central portion is located from the second end portion. The second electrode extends from the fourth end portion in a direction opposite to the side where the central portion is located, and a fourth extension portion substantially parallel to the surface of the dielectric layer is extended. .

  (6) In the plasma display panel according to (1), the first electrode and the second electrode are bent, and the first electrode and the second electrode are separated from each other by the bending. On the other hand, the inclined portion is included, and a first virtual extended surface obtained by extending the main surface of the first inclined portion and a second virtual obtained by extending the main surface of the second inclined portion. Of the four corners obtained by intersecting the extended surfaces, the angle of the corner that is open toward the second substrate side is not less than 45 degrees and not more than 150 degrees.

In order to achieve the above object, the present invention is characterized by the following.
(7) The first substrate and the second substrate are arranged side by side at a distance, and a pair of the first electrode and the second electrode on the surface of the first substrate facing the second substrate, A plasma display panel in which a dielectric layer covering a first electrode and a second electrode is formed, and a plurality of discharge cells are scattered along a pair of the first electrode and the second electrode. A concave portion having a flat bottom surface is formed on the surface of the dielectric layer, and the plate-like third electrode is in the vicinity of the first electrode and is inward of the first substrate than the first electrode. The plate-like fourth electrode is disposed at a position away from the surface, and is disposed near the second electrode and at a position farther from the inner surface of the first substrate than the second electrode. Among the plurality of side surfaces existing between the opening of the concave portion and the bottom surface portion, at least substantially in a facing relationship. The first side surface portion and the second side surface portion are inclined so that the interval between the first side surface portion and the second side surface portion increases as they approach the opening, and the third electrode is plate-shaped and is in the vicinity of the first side surface portion. And the first inclined portion is in a substantially parallel relationship with the first side surface portion, the fourth electrode is plate-shaped and is present in the vicinity of the second side surface portion, It has the 2nd inclination part which has a substantially parallel relationship with two side parts, It is characterized by the above-mentioned.

  (8) In the plasma display panel according to (7), the bottom surface portion is in a substantially parallel relationship with the first substrate, and the first end portion of both end portions positioned in the tilt direction of the first tilt portion. Is located closer to the center of the recess than the other second end, and among the ends located in the tilt direction of the second inclined portion, the third end is more than the other fourth end. Located near the center of the recess, the first end and the third end are substantially equal in distance to the inner surface of the first substrate, and the second end and the fourth end are the first substrate. The distance from the inner surface is substantially equal, and the third electrode has a first extension portion extending substantially parallel to the bottom surface portion of the concave portion from the first end portion toward the side where the central portion is located. The fourth electrode has a second extending portion substantially parallel to the bottom surface portion of the concave portion from the third end portion toward the side where the central portion is located. It has been issued.

With the configuration of (1) above, when the discharge is started, the first side surface portion and the second side surface portion, which are the main discharge surfaces, are in a substantially opposing relationship, so that the discharge surfaces approach the state of facing each other, and the discharge space The electron trajectory inside approaches a straight line.
Therefore, electrons are efficiently accelerated and the discharge start voltage is lowered.
Here, the substantially opposing relationship means a state where the surfaces are not located on the same plane and are not in a parallel relationship.

Furthermore, since the first electrode and the second electrode exist in the vicinity of the first and second side surfaces, respectively, and the side surface and the electrodes existing in the vicinity have a substantially parallel relationship, the first electrode and the second electrode It is easy to increase the electric field strength in the recess that becomes a discharge space when a voltage is applied to the electrode.
In addition, with the configuration of (2) above, that is, the presence of the first extension portion, the first electrode is not interrupted at the side surface portion of the concave portion, thereby reducing variations in the electric field strength of the discharge space between cells. can do.

That is, when it is necessary to reliably form the first electrode in the range from the first end to the second end, and to reliably form the second electrode in the range from the third end to the fourth end, By extending the electrode to a larger range including these ranges, formation of the electrode in the target range is easily ensured, and the performance is stably exhibited, that is, the discharge start voltage is stably reduced. It can be carried out.
In addition, since the shape of the concave portion is not complicated by the configuration of (3) above, options of a manufacturing method capable of forming the dielectric layer having the concave portion as described above are widened, and the cost is easily reduced.

Moreover, the following effect is show | played by the structure of said (4).
That is, in general, the range of the electrodes that contribute to the discharge is the central portion of the cell, that is, the vicinity of the shortest portion between the pair of electrodes, and even if the electrode is formed in the peripheral portion of the cell, The electrode does not contribute much to the discharge. Even if an electrode is formed in such a range that does not contribute much to the discharge, only the electrode capacity increases and reactive power increases, so no electrode is provided between cells that do not contribute to the discharge. Thus, more efficient discharge can be performed.

Moreover, the following effect is show | played by the structure of said (5).
That is, after the discharge is started, the main discharge surface spreads from the vicinity of the place where the distance between the first and second electrodes is the smallest to the periphery thereof. The electric field strength of the part can be increased.
That is, even after the start of discharge, efficient discharge is performed.

Further, with the configuration (6), the first and second transparent electrodes straddling the bent portion are less likely to be disconnected at the bent, and an effect of reducing the discharge start voltage is obtained.
In addition, with the configuration of (7) above, when the discharge is started, the first side surface portion and the second side surface portion, which are the main discharge surfaces, are in a substantially opposed relationship, so that the discharge surfaces approach a state of facing each other, The trajectory of electrons in the discharge space approaches a straight line.

Therefore, electrons are efficiently accelerated and the discharge start voltage is lowered.
Furthermore, since the third electrode and the fourth electrode are present in the vicinity of the first and second side surfaces, respectively, and the side surface and the electrodes existing in the vicinity are in a substantially parallel relationship, the third electrode and the fourth electrode It is easy to increase the electric field strength in the recess that becomes a discharge space when a voltage is applied to the electrode.
Further, with the configuration of (8) above, that is, the presence of the first extending portion, the third electrode is not interrupted at the side surface portion of the concave portion, thereby reducing the variation in the electric field strength of the discharge space for each cell. can do.

  That is, when it is necessary to reliably form the third electrode in the range from the first end to the second end, and to reliably form the fourth electrode in the range from the third end to the fourth end, By extending the electrode to a larger range including these ranges, formation of the electrode in the target range is easily ensured, and the performance is stably exhibited, that is, the discharge start voltage is stably reduced. It can be carried out.

<Embodiment 1>
<Configuration>
Hereinafter, PDP 100 in the first embodiment will be described.
FIG. 1 shows an AC plasma display panel in which a PDP 100 can stably reduce a discharge start voltage.

FIG. 2 is a diagram showing a cross-sectional shape of the PDP 100 divided by a YZ plane passing through the center of the discharge cell, that is, the line AA ′ in FIG.
The PDP 100 is composed of a front plate 200 and a back plate 300 that are disposed with their main surfaces facing each other. The outer peripheral edge of the PDP 100 is fused with a sealing glass (not shown) in a stacked state. It is sealed and a discharge space is formed inside.

The front plate 200 includes a front glass substrate 210, display electrodes 230, dielectric layers 220 and 240, and a protective layer 250.
The front glass substrate 210 is a material that becomes a base of the front plate 200, and a dielectric layer 220 is formed on the front glass substrate 210.
This dielectric layer 220 is a layer made of a dielectric material and having a thickness D1 of about 50 μm. Generally, lead-based low-melting glass is used, but bismuth-based low-melting glass or lead-based low-melting glass is used. You may form with the laminated body of melting | fusing point glass and a bismuth type | system | group low melting glass.

In addition, in this dielectric layer 220, each discharge cell is provided with a concave portion 220a having a truncated pyramid shape in the vicinity of the center thereof independently.
In the first embodiment, the bottom surface portion of the recess 220a is composed of the front glass substrate 210. However, a thin dielectric layer 220 may exist on the bottom surface portion, and in that case, a functional difference is present. There is no.

The reason why the recess 220a is provided independently for each discharge cell is that the gap between the surface of the protective layer 250 and a partition wall 340, which will be described later, is prevented so that crosstalk or the like does not occur when the front plate 200 and the back plate 300 are joined. This is because the concave portion 220a is provided to avoid the surface of the protective layer 250 facing the top of the partition wall 340.
The display electrode 230 includes a bus electrode 232 extending in the X-axis direction in the figure, and a transparent electrode 231 extending from the bus electrode to the recess 220a along the Z-axis direction for each discharge cell.

Thus, by disposing the display electrode 230 independently for each discharge cell, charging that does not contribute to discharge, that is, generation of reactive power can be suppressed.
The transparent electrode 231 has a width W1 of 30 to 300 μm (preferably 100 to 300 μm) made of a conductive metal oxide such as ITO, SnO ₂ or ZnO, and a thickness t1 of about 0.1 μm. These two rectangular thin films are stacked on the dielectric layer 220 in one discharge cell.

More specifically, the transparent electrode 231 is laid from the surface portion 220b of the dielectric layer 220 to the vicinity of the outer periphery of the bottom surface portion of the concave portion 220a. In the concave portion 220a, the transparent electrode 231 mainly includes an opening portion and its opening portion. It exists in the inclined side part 220c between the smaller bottom part.
Here, in the transparent electrode 231, a portion existing on the side surface portion 220c is referred to as a transparent electrode inclined portion 231a, and a portion existing on the surface portion 220b is referred to as a transparent electrode surface portion 231b.

That is, as shown in FIG. 2, the end of the transparent electrode 231 close to the recess is bent toward the front glass substrate 210.
In addition, as shown in the detailed view of FIG. 2, an extended portion 231 c extending to the bottom surface of the concave portion 220 a of the transparent electrode 231 is further provided at the end of the transparent electrode 231 near the concave portion 220 a.
The lengths M1 and M2 of the extending portion 231c are about 5 μm, and M1 <M2 and M1> M2 may be satisfied depending on manufacturing errors.

In addition, the distance L1 between the ends of the extended portion 231c in the pair of transparent electrodes 231 takes a substantially constant value of about 100 μm.
Due to the presence of the extending portion 231c, the end portion of the transparent electrode 231 is positioned on the bottom surface portion of the recess 220a, that is, the transparent electrode 231 is not interrupted on the side surface portion 220c.
That is, in the side surface portion 220c of the recess 220a where the transparent electrode 231 is laid, it is ensured that the transparent electrode 231 having the width W1 is formed in the entire region in the Z-axis direction, and contributes greatly to the discharge at the start of discharge. The interval L1 between the end portions of 231 and the shape of the transparent electrode inclined portion 231a are stabilized.

The reason why the transparent electrode inclined portion 231a greatly contributes to the discharge at the start of discharge is that the inclined side surface portion 240c of the dielectric layer 240 formed on the transparent electrode inclined portion 231a is the main discharge surface at the start of discharge. This is because the transparent electrode inclined portion 231a becomes the electrode closest to the main discharge surface.
Of the four angles obtained by intersecting the virtual extension surfaces of the transparent electrode inclined portions 231a facing each other, the angle θ1 of the angle opened toward the back plate 300 is 45 degrees or more and 150 degrees or less (preferably 70 degrees). The range is 110 degrees or less.

Hereinafter, the reason for defining the value of the angle θ1 in this way will be described.
1) When the angle θ1 is smaller than 45 degrees, since the transparent electrode 231 is a thin film of about 0.1 μm, the angle of the bent portion of the transparent electrode 231 approaches an acute angle, and the bent portion easily breaks. Therefore, the yield is significantly reduced.
2) When the angle θ1 is larger than 150 degrees, the effect of reducing the discharge start voltage is reduced.

That is, if the angle is too close to 180 degrees which is the value of the angle θ1 in the conventional surface discharge type PDP, the counter discharge approaches the surface discharge, and the effect of improving the discharge efficiency by the counter discharge is reduced.
For the above two reasons, the value of the angle θ1 is determined within the range of 45 degrees to 150 degrees.

The bus electrode 232 is made of a conductive material containing Ag, and has a thickness of about tens of μm. The bus electrode 232 is an end of the discharge cell, and is laid in the X-axis direction on the dielectric layer 220 and the transparent electrode 231. ing.
Strictly speaking, there is a step at the boundary between the dielectric layer 220 and the transparent electrode 231. However, as described above, since the thickness of the transparent electrode 231 is as thin as about 0.1 μm, the step is ignored. It is the size that can be done.

The dielectric layer 240 covers the display electrodes 230, the bus electrodes 232, and the front glass substrate 210.
The dielectric layer 240 is a layer made of the same material as the dielectric layer 220 and having a thickness of about 50 μm.
The dielectric layer 220 and the dielectric layer 240 do not have to be the same material. However, the same material as the dielectric layer 220 is used for the dielectric layer 240 in order to reduce the shrinkage rate between the two layers in the firing step described later in the manufacturing method. This is desirable because there is no difference.

The protective layer 250 is a thin film layer made of magnesium oxide (MgO) and covers the entire surface of the dielectric layer 240.
Since the dielectric layer 240 and the protective layer 250 have a substantially constant thickness, the surface shape thereof follows the shape of the base material on which they are laminated.
That is, in the dielectric layer 240, in the vicinity of the recess 220a provided in the dielectric layer 220, a recess 240a having a shape along the contour shape of the recess 220a and having a depth D2 of about 50 μm is formed. .

There are four inclined side surfaces between the opening and the bottom surface of the recess 240a, and among these surfaces, the side surfaces 240c that are in a facing relationship close to the transparent electrode 231 are at the start of discharge. A region where a strong electric field concentrates in the vicinity of the discharge gap becomes the main discharge surface.
The occurrence of discharge is due to the avalanche phenomenon caused by electrons accelerated by the electric field, and as a result, the trajectory of the electrons in the discharge space approaches a straight line as the discharge surfaces approach each other as much as possible. Is efficiently accelerated, and the discharge start voltage is lowered.

Of the four corners obtained by crossing the virtual extension surfaces of the side portions 240c facing each other, the angle θ2 of the corner opened toward the back plate 300 is 45 ° or more and 150 ° or less (preferably according to the shape of the base). Is in the range of 70 degrees to 110 degrees.
By the way, after the discharge is started, the discharge range is widened, and the surface of the dielectric layer 240 in the vicinity where the transparent electrode 231 is disposed becomes the discharge surface.

The back plate 300 is formed on the wall surface of the back glass substrate 310, the address electrode 320, the dielectric layer 330, the partition 340, and the gap between the adjacent partitions 340 (hereinafter referred to as “partition groove”). And phosphor layers 350 corresponding to the respective colors of red, green and blue.
In the discharge space, for example, a discharge gas in which 5 to 30% xenon gas is mixed with neon gas is enclosed.

A region where a pair of adjacent display electrodes 230 and one address electrode 320 intersect with each other across the discharge space is a cell contributing to image display.
In the discharge space, vacuum ultraviolet rays are generated along with the discharge, and the phosphor layer 350 corresponding to each color of red, green, and blue is excited to emit light to display a color.
<Effect of providing an extended portion on a transparent electrode>
Usually, when a front substrate of a PDP is created, the display electrode is created by using a manufacturing method such as photolithography, and the display electrode is formed with the masking member being left biased to the left or right. In this case, in one of the two display electrodes, the lower end portion on the side surface portion may be formed at a position away from the front glass substrate.

The inventors have found that the relative positional relationship between the concave portion of the dielectric layer and the display electrode is likely to be unstable, which causes variations in electric field strength from cell to cell.
Therefore, the inventors considered to eliminate the cause of the above-mentioned variation by strictly implementing the management at the time of manufacturing the PDP and increasing the dimensional accuracy of the parts, but this causes an increase in the management cost. They sought ways to solve the problem at a lower cost.

As a result of intensive studies, the inventors reviewed the structure of the transparent electrode and decided to provide the extending portion 231c on the transparent electrode 231.
Thereby, even if the position of the masking member is shifted to the left or right, the end of the transparent electrode 231 is positioned on the bottom surface of the recess 220a.
Therefore, the transparent electrode 231 is not interrupted on the side surface portion 220c, and it is possible to prevent variation in the length of the portion that greatly contributes to the discharge of the transparent electrode.

As a result, it is possible to manufacture a PDP that does not impair the effect of the discharge start voltage even if the manufacturing management is carried out in the same manner as before.
<Discharge start voltage reduction effect>
In the PDP 100 of the first embodiment, the discharge start voltage is reduced by about 10 to 15 V compared to the conventional PDP.
<Manufacturing method of PDP 100>
Hereinafter, a method for manufacturing PDP 100 in the first embodiment will be described.

The manufacturing method of the PDP 100 is different from the manufacturing method of the conventional PDP only in the manufacturing method of the front plate, particularly the transparent electrode.
Hereinafter, the manufacturing method of the front plate 200 which is a characteristic part of the present invention will be described, and description of the manufacturing method of other parts will be omitted.
1. First Film Formation Step As shown in FIG. 3A, for example, a dielectric layer precursor 220j in which a lead-based low-melting glass powder and a negative photosensitive paste are mixed is changed to about 50 + α A shrinkage allowance) is applied to the front glass substrate 210 with a thickness of μm using a known technique such as a printing method and dried.
2. 1st exposure process Then, as shown in FIG.3 (b), using the photomask 610, light is irradiated only to the part to exclude in a shape of the dielectric material layer precursor 220j, and it is made to chemically react, and the light exposure was applied. The elution action of the portion 220k with respect to a first etching solution to be described later is enhanced so that the portion 220k is easily peeled in the first developing step to be described later.

The photomask 610 has a rectangular opening at each position serving as the center of the cell, and only this portion is exposed. Therefore, the exposure portion 220k is independently formed in a rectangular shape at the center of the cell.
3. First Etching Step As shown in FIG. 3C, by immersing the front glass substrate 210 coated with the dielectric layer precursor 220j in a first etching solution to elute the negative photosensitive paste of the exposed portion 220k. The exposed portion 220k is peeled off to form a dielectric layer precursor 220l having a desired shape.
4). First firing step As shown in FIG. 3 (d), the front glass substrate 210 on which the dielectric layer precursor 220l is formed is put into a firing furnace, and fired at a predetermined temperature profile. To do.
5). Second Film Formation Step As shown in FIG. 3E, for example, a conductive metal oxide such as ITO is formed on the front glass substrate 210 and the dielectric layer 220 with a thickness of, for example, 0.1 μm by a known method such as sputtering. The transparent electrode film 231j is formed using the above technique.
6). Photoresist Forming Step Thereafter, as shown in FIG. 3F, a photoresist 615 is formed on a portion to be left as the transparent electrode 231.
7). Second Etching Step As shown in FIG. 3G, the front glass substrate 210 on which the transparent electrode film 231j and the dielectric layer 220 are formed is immersed in a second etching solution to etch the transparent electrode film 231j, The resist is peeled off to form a transparent electrode 231 having a desired shape.
8). Third film forming step As shown in FIG. 4A, for example, a negative photosensitive Ag paste 232j is formed to a thickness of 10 + γ (γ is a shrinkage allowance during firing) μm, for example, with a front glass substrate 210, The dielectric layer 220 and the transparent electrode 231 are applied using a known technique such as a printing method and dried.
9. 2nd exposure process Then, as shown in FIG.4 (b), the photomask 620 is formed, light is applied only to the part to exclude from the shape of the negative photosensitive Ag paste 232j, and it is made to react chemically, and light is irradiated. The elution action of the exposed exposed portion 232k with respect to a third etching solution, which will be described later, is enhanced so that it can be easily peeled off in a third developing step, which will be described later.
10. Third Etching Step As shown in FIG. 4C, the front glass substrate 210 coated with the photosensitive Ag paste 232j is immersed in a third etching solution to elute the photosensitive paste of the exposed portion 232k, thereby exposing the exposed portion. 232k is peeled off to form a bus electrode precursor 232l having a desired shape.
11. 4th film-forming process As shown in FIG.4 (d), on the formation of the laminated body of the front glass substrate 210 which passed through the 3rd image development process, for example, lead system low melting glass powder and organic paste are mixed. The dielectric layer precursor 240j is applied to the front glass substrate 210 with a thickness of about 50 + ε (ε is a shrinkage allowance during firing) μm using a known technique such as a printing method, and dried.

There is a concave portion on the surface on which the dielectric layer precursor 240j is applied. Here, the effectiveness of the concave portion having a flat bottom surface portion will be described.
If the concave portion has a V-shaped cross-sectional shape, the dielectric layer precursor 240j tends to accumulate in the concave portion when the dielectric layer precursor 240j is applied, but the PDP 100 according to the first embodiment. Then, since the said recessed part has a flat bottom face part, the dielectric layer precursor 240j is hard to accumulate in a recessed part, and it is suppressed that the film thickness is locally formed thickly.
12 Second Firing Step As shown in FIG. 4 (e), the front glass substrate 210 in which the laminate is formed on the surface obtained through the fourth film forming step is put into a firing furnace, and a predetermined temperature profile is obtained. The bus electrode precursor 232l and the dielectric layer precursor 240j that have been baked and formed on the front glass substrate 210 are converted into the bus electrode 232 and the dielectric layer 240, respectively.
13. 5th film-forming process As shown in FIG.4 (f), the protective layer 250 which consists of magnesium oxide, for example on the side in which the laminated body of the front glass substrate 210 which passed through the 2nd baking process is formed is about 0.00. It is formed on the laminate of the front glass substrate 210 with a thickness of 5 μm using a known technique such as an electron beam evaporation method.

As a result, a series of steps performed to create the front plate 200 is completed.
<Precautions for manufacturing>
In the manufacturing method according to the first embodiment, a manufacturing method is used in which the dimensions and the positional relationship of the discharge gap are easily stabilized so that the discharge start voltage can be stably reduced.
Hereinafter, the said manufacturing method is demonstrated.

FIGS. 5A and 5B are diagrams for explaining the details of the photoresist forming process.
A photoresist 615 is formed on the transparent electrode film 231j as shown in FIG. 5A using a photomask having a line-shaped discontinuous region in the center.
There is a possibility that the formation position of the photoresist 615 is deviated to either the left or right of the figure due to variations in the mounting position of the photomask.

That is, the center line of the photoresist formation position may not coincide with the center line of the recess 220a formed by laminating the dielectric layer 220 on the front glass substrate 210.
FIG. 5A is an example of such a case, and shows a case where the photoresist 615 is largely offset to the left side of the drawing.
Even if the photoresist 615 is formed so as to be offset to the left or rightmost, the photoresist 615 is an extension extending in parallel with the front glass substrate 210 surface so as to cover the bottom surface of the recess 220a so as not to be exposed. There is an exit 615a.

For this reason, a part of the transparent electrode 231 inevitably remains on the bottom surface portion of the recess 220a, which originally does not need to form the transparent electrode 231.
By doing so, as shown in FIG. 5B, the height D4 of the transparent electrode 231 formed on the side surface portion 220c of the recess 220a can be set to the same value on both the left and right sides. The electric field distribution between the transparent electrodes 231 will be made more uniform.

On the other hand, as shown in FIG. 6A, in the case where the photoresist 616 without the above-described extension portion is formed, if the formation position is offset to the left, the left side surface portion of the recess 220a. The vicinity of the bottom at 220c will be exposed.
Therefore, as shown in FIG. 6B, the height D6 of the transparent electrode 231 formed on the left side surface 220c of the recess 220a and the height of the transparent electrode 231 formed on the right side surface 220c of the recess 220a. D5 will take a different value.

This is the same as the case where one of the pair of electrodes is smaller than the other electrode, and the discharge efficiency is reduced as the electrode area is reduced.
As described above, according to the PDP of the first embodiment, the side surface located between the opening and the bottom surface smaller than the opening is inclined near the center of the discharge cell on the surface of the dielectric layer 240. The pair of side surface portions 240c having the transparent electrode 231 on the back surface side of the side surfaces become the main discharge surfaces, and therefore, the discharge mode approaches from the surface discharge to the counter discharge, Since electrons in the discharge space can be efficiently accelerated, the discharge start voltage can be reduced.

Further, since the bending angle of the transparent electrode 231 is set in a range in which disconnection is unlikely to occur and the discharge start voltage can be reduced, both productivity and efficiency improvement can be achieved.
In addition, since the concave portion 220a of the dielectric layer 220 and the concave portion 240a of the dielectric layer 240 have flat bottom portions, the side surfaces 220c and 240c of the concave portions are formed so as to extend and intersect with each other. Rather than this, it is more effective when forming a recess in a dielectric layer having a limited thickness.

In addition, a transparent electrode inclined portion 231a of the transparent electrode 231 is formed at a distance from the side surface portion 240c by the thickness of the dielectric layer 240 in the lower layer of the side surface portion 240c, so that the electric field can be moved quickly. It is possible to promote the reduction of the discharge start voltage.
Further, at the end of the transparent electrode 231 close to the concave portion, there is an extended portion 231c extending to the bottom surface portion of the concave portion 220a of the dielectric layer 220, and the transparent electrode is inclined over the entire lower layer of the side surface portion 240c. It is ensured that the portion 231a is formed, and the effect of promoting the reduction of the discharge start voltage can be stably exhibited.

In the PDP manufacturing method according to the first embodiment, the printing method is used as the method for forming the dielectric layer. However, the present invention is not limited to this, and other methods, for example, Japanese Patent Application Laid-Open No. 2003-142006. The method using a dielectric sheet described in the above may be applied.
The above-described method using a dielectric sheet is a method in which a sheet dielectric having a dielectric material previously formed on a support film is placed on a main body side member such as the front glass substrate 210 and is baked after exposure and development.

In the first embodiment, the dielectric layer is formed by removing a part of the dielectric layer. However, the present invention is not limited to this method. For example, the front glass substrate 210 may be etched to provide a recess. Good.
In that case, the first film formation step is not necessary, and the number of steps can be reduced, so that the manufacturing cost is reduced as compared with the printing method.

In the first embodiment, the transparent electrode 231 has the extended portion 231c extending to the bottom surface of the recess 220a. However, the transparent electrode 231 is transparent over the entire lower layer of the side surface portion 240c, that is, the entire side surface portion 220c. When it is guaranteed that the electrode inclined portion 231a is formed, the extension portion 231c may be omitted.
In the first embodiment, the shape of the concave portion 220a and the concave portion 240c is a quadrangular pyramid. However, the shape is not limited to this, and for example, a triangular pyramid may be used. A polygonal frustum such as a hexagonal frustum may be used.

Further, in the case of a polygonal frustum, at least two surfaces that are substantially opposite to each other may be inclined and the other two surfaces may be perpendicular to the bottom surface.
In that case, a transparent electrode is formed on an inclined surface with a gentle bending angle that is less likely to cause disconnection.
In the first embodiment, the transparent electrode 231 is individually formed for each discharge cell. However, the transparent electrode 231 is expanded to the extent that the width W1 is substantially the same as the width of the PDP 100, and one transparent electrode 231 is provided. It may be integrated with the transparent electrode.

In that case, there is an advantage that the structure of the photomask for forming the transparent electrode can be simplified.
On the other hand, as shown in FIG. 1, a transparent electrode is also formed on the B part where the surface change is remarkable, and there is a possibility that a problem such as peeling of the transparent electrode in the B part may occur. Care must be taken.

On the contrary, in the first embodiment, since the transparent electrode is formed avoiding the portion B where the surface change is remarkable, problems such as peeling of the transparent electrode hardly occur, and the yield is improved.
<Modification 1>
Hereinafter, it is a figure explaining the front plate 400 of PDP110 which is an example which changed the shape of the front plate 200 of PDP100 in Embodiment 1. FIG.

FIG. 7 is a cross-sectional view of PDP 110 and corresponds to FIG. 2 of the first embodiment.
A front plate 400 that replaces the front plate 200 is different from those of the front plate 200 in both shapes of the display electrode and the two dielectric layers.
More specifically, the dielectric layer 420 disposed in place of the dielectric layer 220 has a recess similar to that of the dielectric layer 220, but the side surface area of the dielectric layer 220 is the same as that of the dielectric layer 220. The front plate 400 is larger in the value of the angle θ <b> 1 than the front plate 200.

As shown in FIG. 7, the transparent electrode 431 is composed of only the transparent electrode inclined portion 431b formed on the side surface portion of the dielectric layer 420 and the extending portion 431a extending only a part of the bottom surface portion of the concave portion. It differs from the transparent electrode 231 in that it is not formed on the surface of the dielectric layer 420.
That is, the bent portion of the transparent electrode 431 is reduced by one than the bent portion of the transparent electrode 231.

The bus electrode 232 is disposed at the same position as the front plate 200, but the angle is not parallel to the front glass substrate 210 as in the front plate 200, and the transparent electrode 431 is disposed. Is inclined at the same angle.
In addition, the dielectric layer 440 instead of the dielectric layer 240 is also different in shape from the dielectric layer 240 due to the difference in the shape of the underlying layer, and the value of the angle θ2 of the recess formed on the surface is also The value is substantially the same as the value of the angle θ1.

The PDP 110 can be created using the same method as the method for manufacturing the PDP 100.
With the above configuration, the number of bent portions at which the transparent electrode is likely to be disconnected is reduced, and further, the bending angle becomes gentle, so that the disconnection is further difficult and the yield is improved.
<Modification 2>
Hereinafter, it is a figure explaining the front plate 401 of PDP115 which is an example which changed the shape of the transparent electrode 431 of PDP110 in the modification 1. FIG.

FIG. 8 is a sectional view of PDP 115 and corresponds to FIG. 2 of the first embodiment.
The transparent electrode 531 is different from the transparent electrode 431 in that it is formed only on the side surface of the concave portion of the dielectric layer 420.
That is, the transparent electrode 531 has no bent portion.
The PDP 115 can be created using the same method as the manufacturing method of the PDP 100 and the PDP 110.

With the above configuration, since there are no bent portions where the transparent electrode is easily disconnected, it is difficult to disconnect, and the yield is improved.
When forming the transparent electrode 531 on the side surface of the concave portion of the dielectric layer 420, it is desirable to strictly manage the dimensional accuracy so that the length and area of the transparent electrode do not vary.
<Embodiment 2>
<Configuration>
Hereinafter, PDP 120 in the second embodiment will be described.

FIG. 9 is a cross-sectional view of PDP 120 and corresponds to FIG. 2 of the first embodiment.
PDP 120 is an AC type plasma display panel that can stably reduce the discharge start voltage, similar to PDP 100 of the first embodiment.
A major difference between the PDP 120 and the PDP 100 is that two sets of two electrodes having different distances from the surface of the front glass substrate 210 exist in the discharge cell in the dielectric layer on the front plate side.

More specifically, a display electrode 730 that is disposed on the surface of the front glass substrate 210 and serves as a discharge electrode, and a metal electrode 735 disposed in a dielectric layer at a position away from the surface of the front glass substrate 210. And exist.
The display electrode 730 includes a flat transparent electrode 731 made of a conductive metal oxide such as ITO, SnO ₂ , or ZnO, and a bus electrode 732 made of a conductive material containing Ag.

The metal electrode 735 is made of a metal material, extends to the front and back sides of the cross section shown in FIG. 9, and is electrically connected to the display electrode 730 at the end of the substrate.
More specifically, the metal electrode 735 extends from the side surface portion of the quadrangular pyramid-shaped recess provided in the dielectric layer 720 across the outer periphery of the bottom surface portion and is formed in the bottom surface portion. 735a, an inclined portion 735b formed on the inclined side surface portion of the recess, and a surface portion 735c formed on the surface of the dielectric layer 720.

  The dielectric layer 720 is a layer made of a dielectric material having a thickness of about 25 μm. Generally, lead-based low-melting glass is used, but bismuth-based low-melting glass or lead-based low-melting glass is used. And a laminate of bismuth-based low-melting glass. The dielectric layer 740 is a layer made of a dielectric material and having a thickness of about 50 μm. Note that the dielectric layer 720 and the dielectric layer 740 do not have to be made of the same material, but materials having the same shrinkage rate are desirable.

Further, the angle θ3 corresponding to the angle θ1 in the PDP 100 is in the range of 45 degrees to 150 degrees (preferably 70 degrees to 110 degrees), similarly to the angle θ1.
Further, the angle θ4 corresponding to the angle θ2 in the PDP 100 is also in the range of 45 degrees to 150 degrees (preferably 70 degrees to 110 degrees) similarly to the angle θ2.
In PDP 120 according to the second embodiment, since the discharge is started by applying a voltage to metal electrode 735 formed near the side surface portion 720a that is the main discharge surface at the start of discharge, the discharge start voltage Is reduced.

In addition, since the dielectric layer 720 and the dielectric layer 740 are stacked on the display electrode 730, the thickness of the dielectric layer existing between the discharge space and the display electrode 730 increases. The capacity of the space becomes smaller than before, and the capacity of the discharge electrode as a whole is reduced.
Thereby, since the excessive electric current at the time of discharge is suppressed, discharge efficiency improves.
<Discharge start voltage reduction effect>
The effect of reducing the discharge start voltage in the second embodiment was obtained by reducing the discharge start voltage by 10 to 20 V compared to the conventional PDP1000.

The PDP 120 according to the second embodiment can be created using the same method as the method for manufacturing the PDP 100 according to the first embodiment.
Note that in Embodiment Mode 2, a metal material with low resistance is used because the metal electrode 735 is electrically connected to the display electrode 730, but the metal electrode 735 and the display electrode 730 are not electrically connected. In this case, that is, even when the metal electrode 735 and the display electrode 730 are electrically insulated, the effect of the present invention can be obtained by the dielectric effect.

In this case, a low electrical resistance is not required as the metal electrode 735, and it is desirable that the metal electrode 735 be a transparent electrode made of an ITO film or the like in order to prevent light from being shielded as much as possible.
<Modification>
Hereinafter, it is a figure explaining PDP125 which is an example which changed the shape of the metal electrode of PDP120 in Embodiment 2. FIG.

FIG. 10 is a cross-sectional view of the PDP 125 and corresponds to FIG. 9 of the second embodiment.
Since the PDP 125 has the same structure as the PDP 120 except for the metal electrode 835 corresponding to the metal electrode 735 in the PDP 120, the metal electrode 835 will be described below.
The metal electrode 835 has a shape obtained by removing the extending portion 735a from the metal electrode 735, and the portions corresponding to the inclined portion 735b and the surface portion 735c of the metal electrode 735 are the inclined portion 835b and the surface portion 835c of the metal electrode 835, respectively. Become.
<Discharge start voltage reduction effect>
The effect of reducing the discharge start voltage in the second embodiment is 10 to 20 V lower than that of the conventional PDP 1000 as in the case of the PDP 120.
<Manufacturing method>
If the metal electrode 835 has the above structure, the position of the bottom end portion side of the inclined portion 835b is difficult to stabilize, and the area of the inclined portion 835b also varies. Other than that, it can be created using the same method as the manufacturing method of the PDP 120.

  The present invention is applicable to display devices used for televisions, computer monitors, and the like.

It is a schematic perspective view of PDP in this Embodiment 1. FIG. It is local sectional drawing of PDP in this Embodiment 1. FIG. It is a figure explaining the manufacturing process of PDP in this Embodiment 1. FIG. It is a figure explaining the manufacturing process of PDP in this Embodiment 1. FIG. It is a figure explaining the formation method of the transparent electrode of PDP in this Embodiment 1. FIG. It is a figure explaining the formation method of the transparent electrode in the conventional PDP. It is a figure explaining the modification 1 of PDP in this Embodiment 1. FIG. It is a figure explaining the modification 2 of PDP in this Embodiment 1. FIG. It is local sectional drawing of PDP in this Embodiment 2. FIG. It is a figure explaining the modification of PDP in this Embodiment 2. FIG. It is a schematic perspective view of a general AC type (AC type) PDP. It is local sectional drawing of a general alternating current type (AC type) PDP. 2 is a local cross-sectional view of an AC type (AC type) PDP described in Patent Document 1.

Explanation of symbols

100, 110, 115, 120, 125 PDP
200 Front plate 210 Front glass substrate 220 Dielectric layer 220a Recessed portion 220b Surface portion 220c Side surface portion 220j Dielectric layer precursor 220k Exposed portion 220l Dielectric layer precursor 230 Display electrode 231 Transparent electrode 231a Transparent electrode inclined portion 231b Transparent electrode surface portion 231c Extension part 231j Transparent electrode film 232 Bus electrode 232j Ag paste 232k Exposure part 232l Bus electrode precursor 240 Dielectric layer 240a Recess 240c Recess 240c Side part 240j Dielectric layer precursor 250 Protective layer 300 Back plate 310 Back glass substrate 320 Address electrode 330 Dielectric layer 340 Bulkhead 350 Phosphor layer 400 Front plate 401 Front plate 420 Dielectric layer 431 Transparent electrode 431a Extension portion 431b Transparent electrode inclined portion 440 Dielectric layer 531 Transparent electrode 610 Photomask 615 Photoresist 615a Extension part 616 Photoresist 620 Photomask 720 Dielectric layer 720a Side face part 730 Display electrode 731 Transparent electrode 732 Bus electrode 735 Metal electrode 735a Extension part 735b Inclination part 735c Surface part 740 Dielectric layer 835 Electrode 835b Inclined part 835c Surface part

Claims (8)

A first substrate and a second substrate are arranged side by side at a distance, and a pair of a first electrode and a second electrode on the surface of the first substrate facing the second substrate, and the first electrode And a dielectric layer covering the second electrode, and a plurality of discharge cells are scattered along the paired first electrode and second electrode,
A recess having a flat bottom surface is formed on the surface of the dielectric layer in each discharge cell,
The spacing between the first side surface portion and the second side surface portion that are at least substantially opposed to each other among the plurality of side surface portions existing between the opening portion of the recess and the bottom surface portion increases as the opening portion approaches. Is inclined so that
The first electrode is plate-shaped, has a first inclined portion that exists in the vicinity of the first side surface portion, and is in a substantially parallel relationship with the first side surface portion,
The plasma is characterized in that the second electrode is plate-shaped and has a second inclined portion that exists in the vicinity of the second side surface portion and is substantially parallel to the second side surface portion. Display panel. The bottom portion is in a substantially parallel relationship with the first substrate;
Of the both ends located in the inclination direction of the first inclined portion, the first end is located closer to the center of the recess than the other second end,
Of the both ends located in the inclination direction of the second inclined portion, the third end is located closer to the center of the recess than the other fourth end,
The first end and the third end are substantially equal in distance to the inner surface of the first substrate,
The second end and the fourth end are substantially equal in distance to the inner surface of the first substrate,
The first electrode has a first extension extending substantially parallel to the bottom surface of the recess from the first end toward the side where the center is located,
The second extension part of the second electrode extends from the third end part toward the side where the center part is located, and a second extension part substantially parallel to the bottom face part of the recess part. The plasma display panel as described.   The plasma display panel according to claim 2, wherein the concave portion has a quadrangular frustum contour shape.   The plasma display panel according to claim 2, wherein each of the first electrode and the second electrode exists independently for each of the cells. The first electrode has a third extension extending substantially parallel to the surface of the dielectric layer in a direction opposite to the side where the center is located from the second end,
The fourth electrode is characterized in that a fourth extension part extending substantially parallel to the surface of the dielectric layer extends from the fourth end part in a direction opposite to the side where the central part is located. 5. The plasma display panel according to 4. The first electrode and the second electrode are bent,
In the first electrode and the second electrode, the inclined portion is included in one of the two surfaces partitioned by the bending,
Four obtained by intersecting a first virtual extended surface obtained by extending the main surface of the first inclined portion and a second virtual extended surface obtained by extending the main surface of the second inclined portion. 2. The plasma display panel according to claim 1, wherein an angle of an angle that is open toward the second substrate is 45 ° or more and 150 ° or less. A first substrate and a second substrate are arranged side by side at a distance, and a pair of a first electrode and a second electrode on the surface of the first substrate facing the second substrate, and the first electrode And a dielectric layer covering the second electrode, and a plurality of discharge cells are scattered along the paired first electrode and second electrode,
A recess having a flat bottom surface is formed on the surface of the dielectric layer in each discharge cell,
A plate-like third electrode is disposed in the vicinity of the first electrode and at a position farther from the inner surface of the first substrate than the first electrode;
A plate-like fourth electrode is disposed in the vicinity of the second electrode and at a position farther from the inner surface of the first substrate than the second electrode;
The spacing between the first side surface portion and the second side surface portion that are at least substantially opposed to each other among the plurality of side surface portions existing between the opening portion of the recess and the bottom surface portion increases as the opening portion approaches. Is inclined so that
The third electrode has a plate-like shape, a first inclined portion that exists in the vicinity of the first side surface portion and is in a substantially parallel relationship with the first side surface portion,
The plasma is characterized in that the fourth electrode is plate-shaped and has a second inclined portion that exists in the vicinity of the second side surface portion and is substantially parallel to the second side surface portion. Display panel. The bottom portion is in a substantially parallel relationship with the first substrate;
Of the both ends located in the inclination direction of the first inclined portion, the first end is located closer to the center of the recess than the other second end,
Of the both ends located in the inclination direction of the second inclined portion, the third end is located closer to the center of the recess than the other fourth end,
The first end and the third end are substantially equal in distance to the inner surface of the first substrate,
The second end and the fourth end are substantially equal in distance to the inner surface of the first substrate,
The third electrode has a first extending portion extending substantially parallel to the bottom surface of the concave portion from the first end toward the side where the central portion is located,
8. The fourth electrode according to claim 7, wherein a second extension portion extending substantially parallel to the bottom surface portion of the concave portion extends from the third end portion toward the side having the central portion. The plasma display panel as described.

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