JP2005332601A - Manufacturing method of plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a plasma display panel with excellent discharge characteristics, phosphor brightness and chromaticity shown at a display area, capable of obtaining display quality with little deterioration with the passage of time, of long life and with high reliability. <P>SOLUTION: The manufacturing method of the plasma display panel having a display area in which each unit luminous area is constituted at a position where a main electrode pair and address electrodes cross and a non-display area located outside the display area is provided. In a process of film forming of a protective layer, the film forming is carried out with oxygen partial pressure on the surface of the non-display area of a substrate kept higher than that of the surface of the display area during the film forming, so that impurity gas contained in discharge gas is made adsorbed to the surface of the protective layer of the non-display area at introduction of the discharge gas, and is prevented from mixing inside a discharge space of the display area. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a plasma display panel (PDP) used for an image display device or the like.

  In the AC surface discharge type PDP, as shown in Patent Document 1, a front substrate on which a plurality of main electrode pairs each including a scan electrode and a sustain electrode are formed, and a plurality of address electrodes are formed so as to be orthogonal to the main electrode pairs. The back substrate is placed opposite to form a discharge space between the substrates, the periphery is sealed, and discharge gas such as neon and xenon is sealed in the discharge space. The main electrode pair is a dielectric A protective layer is formed on the dielectric layer. An image is displayed by applying a predetermined voltage to each electrode to generate a discharge in the discharge space and causing the phosphor layer provided on the back substrate to emit light.

  The protective layer is generally formed using a material having high sputtering resistance such as magnesium oxide (MgO), and protects the dielectric layer from ion bombardment caused by discharge. Furthermore, magnesium oxide is a metal oxide having a large secondary electron emission coefficient. By using this as a protective layer, there is an advantage that the discharge start voltage is lowered and driving becomes easy.

Usually, the display area constituted by the unit light emitting area where the main electrode pair and the address electrode intersect is provided so as to avoid the vicinity of the sealing layer where the discharge becomes unstable due to gas discharge. That is, a non-display area having a width of about 2 to 3 cm, for example, is provided outside the display area.
JP 2002-83547 A

  Conventionally, after the front substrate and the rear substrate are arranged to face each other so as to form a discharge space between the substrates and the periphery is sealed, when a discharge gas such as neon or xenon is sealed in the discharge space, moisture or the like There is a problem that the impurity gas is mixed and the impurity gas adheres to the protective layer on the inner surface of the discharge space and the surface of the phosphor layer. Thus, in the discharge space where the impurity gas has adhered, problems such as deterioration of discharge characteristics, phosphor luminance and chromaticity, and changes with time occur.

  The present invention has been made to solve such a problem, and manufactures a PDP capable of obtaining good discharge characteristics in the display region by preventing impurity gas from entering the discharge space of the display region. The purpose is to do.

  In order to achieve the above object, a method of manufacturing a PDP according to the present invention includes forming a dielectric layer so as to cover a main electrode pair composed of a plurality of pairs of scan electrodes and sustain electrodes, and on the dielectric layer. A first substrate provided with a protective layer, and a second substrate provided with a plurality of address electrodes arranged in opposition to the first substrate and intersecting the main electrode, and a partition wall for partitioning a discharge space, A manufacturing method of a PDP having a display area in which a unit light emitting area is formed at a position where the main electrode pair and the address electrode cross each other, and a non-display area located outside the display area, In the step of forming the protective layer, the film formation is performed in a state where the oxygen partial pressure of the surface of the non-display area of the substrate is higher than the surface of the display area during the film formation. The protective layer in By making the film quality of the film easy to adsorb and adsorbing the impurity gas mixed in the discharge gas on the surface of the protective layer in the non-display area, the impurity gas is prevented from mixing in the discharge space of the display area. Is.

  Further, in the step of forming the protective layer, the present invention increases the oxygen partial pressure of the surface of the non-display area of the substrate higher than that of the display area by blowing oxygen to the non-display area of the substrate during the film formation. The film is formed in such a state.

  In the step of forming the protective layer, the protective layer in the non-display area and the display area of the substrate is formed separately by changing the film formation conditions.

  Further, after forming the protective layer, the surface of the protective layer in the non-display area is modified by irradiating the non-display area of the substrate with an ion beam.

  In the present invention, the film forming step is a step using a method selected from a vapor deposition method, a sputtering method, and an ion plating method.

  According to the present invention, it is possible to suppress discharge characteristics, phosphor luminance and chromaticity deterioration due to impurity gas in the discharge space of the display region, and change with time, and to obtain a long-life and reliable display quality. Can do.

  Hereinafter, a method for manufacturing 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 a cutaway part of an AC surface discharge type PDP according to an embodiment of the present invention. In this PDP, a front panel 1 and a back panel 2 are arranged to face each other, a discharge space 3 is formed between them, and a discharge gas made of neon, xenon, or the like is enclosed in the discharge space 3.

  The front panel 1 has the following configuration. That is, a plurality of pairs of main electrodes 7 each including a stripe-shaped scanning electrode 5 and a stripe-shaped sustaining electrode 6 are formed on the front substrate 4 which is a glass substrate, and light shielding is performed between the adjacent main electrode pairs 7. Layer 8 is formed. Then, the dielectric layer 9 is formed so as to cover the main electrode pair 7 and the light shielding layer 8, and the protective layer 10 made of MgO is formed on the dielectric layer 9. The protective layer 10a has a film quality different from that of the protective layer 10 in the display area.

  The back panel 2 has the following configuration. That is, a plurality of stripe-shaped address electrodes 12 are formed on the rear substrate 11, which is a glass substrate, so as to be orthogonal to the scan electrodes 5 and the sustain electrodes 6, and the electrode protection layer 13 is formed so as to cover the address electrodes 12. doing. A partition 14 parallel to the address electrode 12 is provided on the electrode protection layer 13 and between the address electrodes 12, and a phosphor layer 15 is formed between the partitions 14. The electrode protective layer 13 protects the address electrodes 12 and has an effect of reflecting visible light generated by the phosphor layer 15 toward the front panel 1.

  Each main electrode pair 7 constitutes one line, and a cell as a unit light emitting region is formed at a portion where the main electrode pair 7 and the address electrode 12 intersect. Display is performed by generating a discharge in the discharge space 3 of each cell and transmitting visible light of three colors of red, green, and blue generated from the phosphor layer 15 along with the discharge through the front panel 1. .

  FIG. 2 is a block diagram showing a schematic configuration of an image display apparatus configured by connecting a drive circuit to the PDP shown in FIG. As shown in FIG. 2, the address electrode driver 17 is connected to the address electrode 12 of the PDP 16, the scan electrode driver 18 is connected to the scan electrode 5 of the PDP 16, and the sustain electrode driver 19 is connected to the sustain electrode 6 of the PDP 16. Has been.

  FIG. 3 is a diagram for explaining a method of driving the image display apparatus whose schematic configuration is shown in FIG. In general, in an AC surface discharge type PDP, a method is used in which gradation representation is performed by dividing an image of one field into a plurality of subfields. In this method, in order to control discharge in each cell, one subfield is composed of four periods including a setup period, an address period, a sustain period, and an erase period. FIG. 3 is a time chart showing drive waveforms in one subfield.

  In FIG. 3, in the setup period, wall charges are uniformly accumulated in all the cells in the PDP in order to facilitate discharge. In the address period, the write discharge of the cells to be lit is performed. In the sustain period, the cells written in the address period are turned on and kept on. In the erase period, lighting of the cells is stopped by erasing the wall charges.

  In the setup period, by applying an initialization pulse to the scan electrode 5, a voltage higher than that of the address electrode 12 and the sustain electrode 6 is applied to the scan electrode 5 to generate a discharge in the cell. The electric charge generated by the discharge is accumulated on the wall surface of the cell so as to cancel the potential difference among the address electrode 12, the scan electrode 5, and the sustain electrode 6. As a result, negative charges are accumulated as wall charges on the surface of the protective layer 10 in the vicinity of the scan electrode 5, and the positive surface of the phosphor layer 15 in the vicinity of the address electrode 12 and the surface of the protective layer 10 in the vicinity of the sustain electrode 6 are positive. Are accumulated as wall charges. Due to this wall charge, a predetermined wall potential is generated between scan electrode 5 and address electrode 12 and between scan electrode 5 and sustain electrode 6.

  In the address period, when the cell is turned on, a scan pulse is applied to the scan electrode 5 and a data pulse is applied to the address electrode 12, so that a voltage lower than that of the address electrode 12 and the sustain electrode 6 is applied to the scan electrode 5. Apply. That is, a voltage is applied between the scan electrode 5 and the address electrode 12 in the same direction as the wall potential, and a voltage is applied between the scan electrode 5 and the sustain electrode 6 in the same direction as the wall potential. generate. As a result, negative charges are accumulated on the surface of the phosphor layer 15 and the surface of the protective layer 10 near the sustain electrode 6, and positive charges are accumulated on the surface of the protective layer 10 near the scan electrode 5 as wall charges. As a result, a predetermined wall potential is generated between sustain electrode 6 and scan electrode 5.

  In the sustain period, first, a sustain pulse is applied to the scan electrode 5 to apply a voltage higher than that of the sustain electrode 6 to the scan electrode 5. That is, a sustain discharge is generated by applying a voltage between sustain electrode 6 and scan electrode 5 in the same direction as the wall potential. As a result, cell lighting can be started. Subsequently, by applying a sustain pulse so that the polarity between the sustain electrode 6 and the scan electrode 5 is alternately switched, pulsed light can be emitted intermittently.

  In the erase period, an incomplete discharge is generated by applying a narrow erase pulse to the sustain electrode 6 and the wall charges disappear, so that erase is performed.

  The PDP according to the present invention is characterized by the structure of the protective layer 10, and the contents thereof will be described with reference to specific examples.

  FIG. 4 shows a PDP on which a protective layer of this embodiment is formed, and FIG. 5 shows a cross-sectional view taken along the line aa of FIG. An inlet for introducing exhaust gas and discharge gas outside the display area defined by the main electrode pair 7 composed of the scan electrode 5 and the sustain electrode 6 and the address electrode 12 intersecting perpendicularly to the main electrode pair 7. There is a non-display area A including 20. The protective layer 10a in the non-display area A has a film quality different from that of the protective layer 10 in the display area. In FIG. 5, reference numeral 21 denotes a sealing layer.

  First, the apparatus used for the vacuum vapor deposition method when forming the protective layer 10 as described above is generally composed of a preparation chamber, a heating chamber, a vapor deposition chamber, and a cooling chamber, and the substrate is transported in this order, and the protective layer made of MgO. Is formed by vapor deposition. The MgO vapor deposition source (protective layer material) is heated in an oxygen atmosphere using a piercing electron beam gun as a heating source, and the protective layer 10 is formed by a film forming process for forming a desired film. At this time, in order to make the protective layer 10a in the non-display area easier to adsorb the impurity gas than the protective layer 10 in the display area, the surface area of the protective layer 10a in the non-display area may be increased.

  It has been reported that a film formed in an atmosphere having a high oxygen partial pressure has a larger surface area than a film formed in an atmosphere having a low oxygen partial pressure, and easily adsorbs impurity gases (see, for example, J. Vac. Soc.Jpn.Vol.43, No. 10, 2000).

  When MgO is deposited by heating, MgO as a deposition source is decomposed into Mg clusters and O clusters to be vaporized and then recombined, so that the film generally becomes a film having many oxygen vacancies. Therefore, a film with good crystallinity and large crystal grains is formed by increasing the oxygen partial pressure. A film with large crystal grains has a large surface area due to many crystal boundaries (gap between crystal grains), and is a film that easily absorbs impurity gas.

  As a method of increasing the oxygen partial pressure by spraying oxygen on the surface of the protective layer in the non-display area of the substrate during film formation, an oxygen jet port is provided on the outer periphery of the carrier for transporting the substrate through the film formation apparatus. Then, a method of wiping oxygen from the non-display area of the substrate can be considered.

  Further, a method of forming a protective layer for the non-display area and the display area separately and forming films having different film qualities is also conceivable. In other words, when forming a film in the non-display area, the film is formed using a shielding plate or the like in the atmosphere with a high oxygen partial pressure, and when forming a film in the display area, In a low atmosphere, film formation is performed using a shielding plate or the like in the non-display area.

  Furthermore, after the protective film is uniformly formed on the substrate, a method of increasing the surface area by sputtering the surface of the protective film by irradiating only the non-display area with an ion beam using a shielding plate or the like in the display area is also considered. It is done.

  Note that the protective layer can be formed using not only the above-described vacuum deposition method but also a sputtering method, an ion plating method, or the like.

  According to the present invention, the invention is useful for obtaining a PDP having a long life and a reliable display quality.

The perspective view which shows a part of plasma display panel by one embodiment of this invention Block diagram showing an example of an image display device using the plasma display panel Time chart showing the driving waveform of the plasma display panel Schematic diagram of a plasma display panel on which the protective layer of the present invention is formed Sectional drawing of the plasma display panel which formed the protective layer of this invention into a film

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front panel 2 Back panel 3 Discharge space 4 Front substrate 5 Scan electrode 6 Sustain electrode 7 Main electrode pair 8 Light shielding layer 9 Dielectric layer 10, 10a Protective layer 11 Back substrate 12 Address electrode 13 Electrode protective layer 14 Partition 15 Phosphor layer

Claims (5)

A first substrate in which a dielectric layer is formed so as to cover a main electrode pair consisting of a plurality of pairs of scan electrodes and sustain electrodes, and a protective layer is provided on the dielectric layer, and opposite to the first substrate A plurality of address electrodes arranged in a direction intersecting with the main electrode and a second substrate provided with a partition wall for partitioning a discharge space, and each unit is located at a position where the main electrode pair and the address electrode intersect A method of manufacturing a plasma display panel having a display region in which a light emitting region is configured and a non-display region located outside the display region, wherein the substrate is not coated during the film formation in the step of forming the protective layer. A method of manufacturing a plasma display panel, wherein film formation is performed in a state where the oxygen partial pressure of the surface of the display region is higher than that of the surface of the display region. In the step of forming the protective layer, the oxygen partial pressure of the surface of the non-display area of the substrate is made higher than the surface of the display area by blowing oxygen to the non-display area of the substrate during the film formation. The method of manufacturing a plasma display panel according to claim 1. 2. The method for manufacturing a plasma display panel according to claim 1, wherein, in the step of forming the protective layer, the protective layer in the non-display area and the display area of the substrate is separately formed under different film formation conditions. 2. The method of manufacturing a plasma display panel according to claim 1, wherein after forming the protective layer, the surface of the non-display area is modified by irradiating the non-display area of the substrate with an ion beam. . 2. The method of manufacturing a plasma display panel according to claim 1, wherein the film forming step is a step using a method selected from an evaporation method, a sputtering method, and an ion plating method.

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