JP2010262880A - Method of manufacturing plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a plasma display panel in which the amount of facility investment is suppressed and high yield is achieved. <P>SOLUTION: The method of manufacturing the plasma display panel which is formed of a plurality of electrodes with the main discharge gap therebetween, is provided. As for an electrode, a paste layer coated on a substrate is formed by a photolithography method. The method has a first exposure process of exposing a pattern to become point-symmetric having an electrode shape, a second exposure process of exposing the pattern to become point-symmetric having the electrode shape by rotating the substrate exposed by the first exposure process or a photo mask by an angle corresponding to point-symmetry, and a third exposure process of exposing the pattern to become non point-symmetric having the electrode shape. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a plasma display panel used for a color television receiver or display for displaying characters or images, and more particularly to a method for forming an electrode.

  As a display device that can display high-definition television images on a large screen because it can display at high speed compared to a liquid crystal panel and is easy to increase in size, it emits light by exciting phosphors with ultraviolet light from rare gas discharge. Accordingly, there is an increasing expectation for a display device such as a color television receiver using a plasma display panel (hereinafter referred to as “PDP”) that displays an image. PDPs are attracting attention as large-screen display devices for high-definition television, and for this purpose, developments are being actively made to improve display quality, such as higher definition and higher brightness, higher reliability, and lower costs.

  Generally, the AC drive surface discharge PDP adopts a three-electrode structure, and has a structure in which two glass substrates of a front plate and a back plate are arranged to face each other at a predetermined interval. The front plate includes a glass substrate, a pair of display electrodes formed on one main surface thereof, a dielectric film that functions as a capacitor that covers the display electrodes and accumulates charges, and the dielectric film. It is comprised with the MgO protective film formed on the top.

  The back plate is formed by a glass substrate, a striped data electrode formed on one main surface of the glass substrate, a dielectric film covering the data electrode, a partition formed thereon, and each partition. And a phosphor layer that emits red, green, and blue light applied in the discharge cell.

  The front plate and the back plate are hermetically sealed with their electrode forming surfaces facing each other, and a discharge gas such as Ne—Xe is sealed at a pressure of 53000 Pa to 80000 Pa in the discharge cell space formed by the barrier ribs. A color is generated by discharging a discharge gas by selectively applying a video signal voltage between a pair of display electrodes, and ultraviolet rays generated thereby excite each color phosphor layer to emit red, green, and blue colors. An image is displayed.

  In the PDP having such a configuration, shape accuracy and position accuracy are required in forming the display electrode and the data electrode. For this purpose, a material containing a photosensitive material in a conductive material such as a metal material is applied to the glass substrate surface, exposed using an exposure mask having an electrode pattern, and then developed by a photolithography method. A manufacturing method for patterning has been proposed.

  For the purpose of reducing the cost of the PDP, an example is disclosed in which the display electrode is configured by only a mesh-like metal electrode without using a transparent electrode.

  For example, Patent Document 1 is known as prior art document information relating to the invention of this application.

JP 2002-150951 A

  A PDP in which a display electrode is configured by only a mesh-like metal electrode without using a transparent electrode can achieve a lower cost than a PDP having a transparent electrode, but has the following problems.

  A display electrode constituted only by a metal electrode has a fine thin line structure because of the need to increase the aperture ratio. Therefore, the disconnection of the electrode is likely to occur, and the disconnection causes a non-lighting phenomenon or a decrease in luminance. The occurrence of these unlighting phenomena deteriorates the image display quality particularly when displaying with white as a background.

  As a cause of the disconnection of the display electrode, there is foreign matter adhesion to the exposure mask in the exposure process when the display electrode is formed by a photolithography method. When a pattern is formed by UV exposure, if a negative exposure method is used in which the exposed portion remains in the next development step, an opening is formed in the exposure mask so that the electrode line forming the display electrode is the exposed portion. Is formed.

  This is because, when foreign matter having a size larger than the width of the electrode line to be exposed adheres to the opening of the exposure mask, the foreign matter is not exposed and the electrode line is removed in the subsequent development process. In addition, the disconnection of the display electrode caused by the foreign matters attached to these exposure masks has a problem that it continuously occurs in a plurality of PDPs in order to mass-produce using the same exposure mask.

  Further, in the case where the display electrodes are formed only with the metal electrodes having a thin line structure, the width of each electrode line becomes as small as about 40 μm, so that the number of foreign substances adhering to the exposure mask increases as the size of the foreign substance decreases, so that the disconnection The probability of occurrence increases.

  In particular, in such an electrode structure, if the electrode line forming the main discharge gap between the scan electrode and the sustain electrode is disconnected or the interval between the main discharge gaps is changed, the discharge cell including the disconnected portion is not turned off. There is a problem that not only blinking but also a serious display defect such as an increase in discharge start voltage occurs.

  An object of the present invention is to provide a method for manufacturing a PDP that solves such problems, reduces the influence of foreign matter adhering to an exposure mask, prevents defects such as disconnection of display electrodes, and realizes a high yield. It is said.

  In order to solve the above-described problems, a method for manufacturing a PDP according to the present invention is a method for manufacturing a plasma display panel formed by a plurality of electrodes across a main discharge gap, and the electrodes are coated on a substrate. A paste layer is formed by a photolithography method, and a pattern that is point-symmetric with respect to the electrode shape is exposed, and the substrate or photomask exposed in the first exposure step is rotated by an angle corresponding to point symmetry. It has the 2nd exposure process which exposes the pattern used as the point symmetry of an electrode shape, and the 3rd exposure process which exposes the pattern used as an astigmatism of an electrode shape.

  According to such a manufacturing method, when exposing a plurality of electrode lines, the foreign matter adhered to the exposure mask by exposing the unexposed area due to the foreign matter in the previous exposure step in the next exposure step. Thus, the probability of occurrence of disconnection can be reduced and the high yield can be realized.

The perspective view which shows the structure of PDP in embodiment of this invention The figure which shows the general | schematic flow of the process at the time of forming a scanning electrode and a sustain electrode

  Hereinafter, a PDP according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a perspective view showing the structure of a PDP according to an embodiment of the present invention. The basic structure of the PDP according to the embodiment of the present invention is the same as that of a general PDP. As shown in FIG. 1, the PDP 1 has a front plate 2 made of a front glass substrate 3 and a back plate 10 made of a back glass substrate 11 facing each other, and its outer peripheral portion is sealed with a glass frit or the like. The material is hermetically sealed. A discharge gas such as Ne and Xe is sealed at a pressure of 53000 Pa to 80000 Pa in the discharge space 16 inside the sealed PDP 1.

  On the front glass substrate 3 of the front plate 2, a pair of strip-like display electrodes 6 composed of scanning electrodes 4 and sustain electrodes 5 and black stripes (also referred to as light shielding layers) 7 are arranged in a plurality of rows in parallel with each other. A dielectric layer 8 serving as a capacitor is formed on the front glass substrate 3 so as to cover the display electrodes 6 and the light shielding layer 7, and a protective layer 9 made of magnesium oxide or the like is further formed on the surface. .

  On the back glass substrate 11 of the back plate 10, a plurality of strip-like address electrodes 12 are arranged in parallel to each other in a direction orthogonal to the scanning electrodes 4 and the sustain electrodes 5 of the front plate 2. Layer 13 is covering. Further, a partition wall 14 having a predetermined height is formed on the base dielectric layer 13 between the address electrodes 12 to divide the discharge space 16. For each address electrode 12, a phosphor layer 15 that emits red, blue, and green light by ultraviolet rays is sequentially applied to the grooves between the barrier ribs 14 and formed. A discharge cell is formed at a position where the scan electrode 4 and the sustain electrode 5 intersect with the address electrode 12, and the discharge cell having red, blue and green phosphor layers 15 arranged in the direction of the display electrode 6 is used for color display. Become a pixel.

Next, a method for manufacturing PDP 1 in the embodiment of the present invention will be described. The front plate 2 is formed by patterning display electrodes 6 and black stripes 7 composed of scan electrodes 4 and sustain electrodes 5 on a front glass substrate 3 manufactured by a float method or the like. Scan electrode 4 and sustain electrode 5 are each composed of a transparent electrode made of indium oxide (ITO), tin oxide (SnO ₂ ), or the like, and a metal bus electrode formed thereon. The metal bus electrode is used for the purpose of imparting conductivity in the longitudinal direction of the transparent electrode, and is formed of a conductive material mainly composed of a silver (Ag) material. Furthermore, the metal bus electrode is composed of a black black electrode and a white white electrode.

  First, the scan electrode 4, the sustain electrode 5, and the light shielding layer 7 are formed on the front glass substrate 3. The transparent electrode is formed by a thin film process or the like, and is patterned and formed by a photolithography forming method or the like. On the other hand, for the black electrode and the white electrode, a photosensitive paste containing conductive black particles or a silver (Ag) material is applied by a screen printing method or the like to form a photosensitive composition layer, and is patterned by a photolithographic forming method. Bake at temperature to solidify.

  Similarly to the black electrode, the light shielding layer 7 is formed by applying a paste containing a black material by screen printing, patterning and baking using a photolithographic forming method.

  Next, a dielectric paste is applied on the front glass substrate 3 by a die coating method or the like so as to cover the scan electrode 4, the sustain electrode 5, and the light shielding layer 7, thereby forming a dielectric paste layer (dielectric glass layer). After the dielectric paste is applied, the surface of the applied dielectric paste is leveled by leaving it to stand for a predetermined time, so that a flat surface is obtained.

  Thereafter, the dielectric paste layer is baked and solidified to form the dielectric layer 8 that covers the scan electrode 4, the sustain electrode 5, and the light shielding layer 7. The dielectric paste is a paint containing powdery dielectric glass, a binder, and a solvent. Next, a protective layer 9 made of magnesium oxide (MgO) is formed on the dielectric layer 8 by a vacuum deposition method. Through the above steps, predetermined constituent members are formed on the front glass substrate 3, and the front plate 2 is completed.

  On the other hand, the back plate 10 is formed as follows. First, the structure for the address electrode 12 is formed by a method of screen printing a paste containing silver (Ag) material on the rear glass substrate 11 or a method of patterning using a photolithography method after forming a metal film on the entire surface. An address electrode 12 is formed by forming a material layer to be an object and firing it at a desired temperature.

  Next, a dielectric paste is applied on the rear glass substrate 11 on which the address electrodes 12 are formed by a die coating method so as to cover the address electrodes 12 to form a dielectric paste layer. Thereafter, the base dielectric layer 13 is formed by firing the dielectric paste layer. The dielectric paste is a paint containing powdery dielectric glass, a binder, and a solvent.

  Next, a partition wall forming paste including a partition wall material is applied onto the base dielectric layer 13, the partition wall material layer is patterned into a predetermined shape by a photolithography method or the like, and then fired to form the partition walls 14. Here, as a method of patterning the partition wall paste applied on the base dielectric layer 13, a photolithography method or a sand blast method can be used. Next, the phosphor layer 15 is formed by applying and baking a phosphor paste containing a phosphor material on the base dielectric layer 13 between the adjacent barrier ribs 14 and on the side surfaces of the barrier ribs 14. Through the above steps, predetermined constituent members are formed on the rear glass substrate 11 to complete the rear plate 10.

  In this way, the front plate 2 and the back plate 10 having predetermined constituent members are arranged to face each other so that the scanning electrodes 4 and the address electrodes 12 are orthogonal to each other, and the periphery thereof is sealed with a glass frit, so that a discharge space is obtained. 16 is filled with a discharge gas containing Ne, Xe or the like, thereby completing the PDP 1.

  Here, since the PDP 1 has a large screen, the structure of the PDP 1 such as the display electrode 6, the light shielding layer 7, the address electrode 12, and the partition wall 14 requires accuracy with respect to the shape and position. In the manufacturing method of the PDP 1, a photolithography method is often used as a method for forming these structures. Therefore, a photolithography method in the method for manufacturing a PDP according to the present invention will be described with reference to the drawings.

  FIG. 2 is a diagram showing a schematic flow of steps in forming the scan electrode and the sustain electrode. First, a photosensitive paste containing a silver (Ag) material is uniformly applied on the front glass substrate 3 on which a transparent electrode is formed by a screen printing method or the like, and a photosensitive Ag paste layer (hereinafter referred to as a paste layer) is formed. Form.

  Next, in order to form scan electrodes and sustain electrodes by photolithography, first exposure is performed using a point-symmetric pattern photomask 17 having a point-symmetric exposure pattern. On the front glass substrate 3 on which the paste layer has been formed, this point-symmetric pattern photomask 17 is placed at a predetermined position. And it irradiates with ultraviolet rays from an ultra high pressure mercury lamp. In FIG. 2A, it is assumed that dust 18 is attached to the point-symmetric pattern photomask 17. Since dust 18 adheres to the opening of the point-symmetric pattern photomask 17, the area corresponding to the dust 18 on the paste layer is not exposed.

  Next, as shown in FIG. 2B, the second exposure is performed by rotating the point symmetrical pattern photomask 17 or the front glass substrate 3 by an angle corresponding to the point symmetry of the pattern. In the embodiment of the present invention, the point-symmetric pattern photomask 17 is placed on the front glass substrate 3 after being rotated 180 degrees and aligned at a predetermined position.

  By performing the second exposure, the dust 18 adheres to the exposed portion of the point-symmetric pattern photomask 17, so that the second exposure can be performed even if the region corresponding to the dust 18 of the paste layer is not exposed in the first exposure. At the time of exposure, the position corresponding to the dust 18 in the paste layer changes, so that the area not exposed at the time of the first exposure is exposed. Further, in the second exposure, an area where the exposure is newly blocked by dust and is not sensitized is generated at a position rotated by 180 degrees of the exposure pattern, but the area has already been exposed by the first exposure.

  When the point symmetric pattern photomask 17 is rotated 180 degrees, the probability that dust is located at the same position before and after the movement with respect to the paste layer is very small. Therefore, if the exposure is performed twice in total, the point symmetric pattern photo It is possible to eliminate an unexposed area due to exposure being blocked by the dust 18 adhering to the mask 17. Further, by performing exposure using the same photomask, the amount of capital investment for an exposure apparatus, a photomask, and the like can be reduced.

  Next, as shown in FIG. 2 (c), a third exposure is performed by aligning an astigmatism pattern photomask 19 having an exposure pattern that is at least asymmetric with respect to the sustain electrode common portion or the like at a predetermined position. To form a desired pattern.

  As described above, the manufacturing method of the PDP of the present invention is a manufacturing method of a plasma display panel formed by a plurality of electrodes with a main discharge gap interposed therebetween. A first exposure step of exposing a pattern that is formed in point symmetry with respect to the electrode shape and a point symmetry with respect to the electrode shape by rotating an angle corresponding to the point symmetry of the substrate or photomask exposed in the first exposure step. A second exposure step of exposing the pattern to be exposed, and a third exposure step of exposing the pattern that is asymmetric with respect to the electrode shape. This makes it possible to provide a highly reliable PDP with a high yield.

  As described above, the present invention is industrially useful in that it can provide a method of manufacturing a PDP that suppresses the capital investment and realizes a high yield.

1 PDP
DESCRIPTION OF SYMBOLS 2 Front plate 3 Front glass substrate 4 Scan electrode 5 Sustain electrode 6 Display electrode 7 Light shielding layer 8 Dielectric layer 9 Protective layer 10 Back plate 11 Rear glass substrate 12 Address electrode 13 Base dielectric layer 14 Partition 15 Phosphor layer 16 Discharge space 17 point symmetrical pattern photomask 18 dust 19 astigmatic pattern photomask

Claims (1)

A method of manufacturing a plasma display panel formed by a plurality of electrodes across a main discharge gap, wherein the electrodes are formed by photolithography using a paste layer coated on a substrate, A first exposure step for exposing the pattern to be formed, and a second exposure for exposing the pattern that is point symmetric with respect to the electrode shape by rotating an angle corresponding to point symmetry with respect to the substrate or photomask exposed in the first exposure step. A method of manufacturing a plasma display panel, comprising: a step, and a third exposure step of exposing a pattern having asymmetry of the electrode shape.

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