JP2006245019A - Plasma display panel and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form a magnesium oxide film (a protecting film) further improving discharge characteristics of a PDP. <P>SOLUTION: The PDP is equipped with: a front glass substrate 1 and a back glass substrate 6 opposing each other through a discharge space S; a pair of row electrodes (X, Y) formed on the front glass substrate 1; a dielectric layer 3 for covering the pair of row electrodes (X, Y); and a protective layer for covering the dielectric layer 3. The protective layer has a structure where a thin-film magnesium oxide layer 4 formed by deposition or sputtering and a crystal magnesium oxide layer 5 including a particulate magnesium oxide crystal that generates cathode luminescence emission having a peak in a wavelength range of 200 to 300 nm excited by an electron beam are laminated. The thin-film magnesium oxide layer 4 is formed on the dielectric layer 3, and the crystal magnesium oxide layer 5 is formed on the thin-film magnesium oxide layer 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a structure of a plasma display panel and a method for manufacturing the plasma display panel.

  A surface discharge AC plasma display panel (hereinafter referred to as PDP) is a row extending in the row direction to one of the two glass substrates facing each other across a discharge space in which a discharge gas is sealed. The electrode pairs are arranged side by side in the column direction, the column electrodes extending in the column direction are arranged in the row direction on the other glass substrate, and the row electrode pairs and the column electrodes in the discharge space intersect each other in a matrix. A unit light emitting region (discharge cell) is formed.

  In this PDP, the protective function of the dielectric layer and the secondary to the unit light emitting region are provided at a position facing the unit light emitting region on the dielectric layer formed to cover the row electrode and the column electrode. A magnesium oxide (MgO) film having an electron emission function is formed.

  As a method for forming a magnesium oxide film in such a PDP manufacturing process, a screen printing method in which a paste mixed with magnesium oxide powder is applied onto a dielectric layer is a simple method. Adoption has been studied (for example, see Patent Document 1).

  However, as in Patent Document 1, when a magnesium oxide film of PDP is formed by screen printing using a paste mixed with polycrystalline single-leaf magnesium oxide purified by heat treatment of magnesium hydroxide, The discharge characteristics of the PDP are almost the same or slightly improved as when a magnesium oxide film is formed by vapor deposition.

  For this reason, it is desired that a magnesium oxide film (protective film) that can further improve the discharge characteristics can be formed on the PDP.

JP-A-6-325696

  An object of the present invention is to solve the problems in the conventional PDP on which the magnesium oxide film as described above is formed.

  In order to solve the above-mentioned problem, a plasma display panel according to a first invention (the invention according to claim 1) includes a front substrate and a rear substrate facing each other through a discharge space, In a plasma display panel having a discharge electrode formed on at least one substrate, a dielectric layer covering the discharge electrode, and a protective layer covering the dielectric layer, the protective layer is formed by vapor deposition or sputtering. The thin-film magnesium oxide layer formed and the crystalline magnesium oxide layer containing particulate magnesium oxide crystals that emit cathode luminescence having a peak in the wavelength range of 200 to 300 nm when excited by an electron beam were laminated. And having the structure, and the thin-film magnesium oxide layer is formed on the dielectric layer To is characterized in that the crystalline MgO layer is formed on the thin-film MgO layer.

  A plasma display panel manufacturing method according to a second invention (invention of claim 12) includes a front substrate and a rear substrate which are opposed to each other through a discharge space, and the front substrate and the rear surface. A plasma display panel having a discharge electrode formed on at least one of the substrates, a dielectric layer covering the discharge electrode, and a protective layer formed on the dielectric layer and covering the dielectric layer The step of forming the protective layer includes a step of forming a thin-film magnesium oxide layer by vapor deposition or sputtering, and a cathode having a peak in a wavelength range of 200 to 300 nm when excited by an electron beam. Forming a crystalline magnesium oxide layer containing particulate magnesium oxide crystals that emit luminescence; and Wherein, after the step of forming the thin-film MgO layer is performed, is characterized by forming a crystalline MgO layer is carried out.

  In the PDP according to the present invention, a row electrode pair extending in the row direction and a column electrode that extends in the column direction and forms discharge cells in a discharge space at the intersection of the row electrode pair are disposed between the front glass substrate and the rear glass substrate. The row electrode pair or the column electrode is provided and covered with a dielectric layer, and a protective layer covering the dielectric layer is excited by an electron beam and a thin film magnesium oxide layer formed by vapor deposition or sputtering. Having a laminated structure with a crystalline magnesium oxide layer containing a particulate magnesium oxide crystal that emits cathode luminescence with a peak in the region of 200 to 300 nm, and a thin film magnesium oxide layer is formed on the dielectric layer, A PDP in which a crystalline magnesium oxide layer is formed on a thin film magnesium oxide layer is the best embodiment.

  The PDP in this embodiment is a particle that emits cathode luminescence having a peak in a wavelength range of 200 to 300 nm when a crystalline magnesium oxide layer constituting a laminated structure of a protective layer of a dielectric layer is excited by an electron beam. By including the shaped magnesium oxide crystal, the discharge characteristics such as discharge probability and discharge delay in the PDP are improved, and good discharge characteristics can be obtained.

  1 to 3 show an example of an embodiment of a PDP according to the present invention, FIG. 1 is a front view schematically showing the PDP in this example, and FIG. 2 is a cross-sectional view taken along line V-V in FIG. FIG. 3 and FIG. 3 are sectional views taken along line WW in FIG.

  The PDP shown in FIGS. 1 to 3 has a plurality of row electrode pairs (X, Y) in the row direction of the front glass substrate 1 (left and right direction in FIG. 1) on the back surface of the front glass substrate 1 as a display surface. They are arranged in parallel so as to extend.

  The row electrode X includes a transparent electrode Xa made of a transparent conductive film such as ITO formed in a T shape, and a metal film that extends in the row direction of the front glass substrate 1 and is connected to a narrow base end portion of the transparent electrode Xa. And the bus electrode Xb.

  Similarly, the row electrode Y is connected to the transparent electrode Ya made of a transparent conductive film such as ITO formed in a T-shape and the narrow base end portion of the transparent electrode Ya extending in the row direction of the front glass substrate 1. The bus electrode Yb is made of a metal film.

  The row electrodes X and Y are alternately arranged in the column direction (vertical direction in FIG. 1) of the front glass substrate 1, and the transparent electrodes Xa and Ya arranged in parallel along the bus electrodes Xb and Yb are respectively Extending to the paired row electrode side, the tops of the wide portions of the transparent electrodes Xa and Ya are opposed to each other via a discharge gap g having a required width.

  The back surface of the front glass substrate 1 extends in the row direction along the bus electrodes Xb and Yb between the bus electrodes Xb and Yb of the row electrode pairs (X, Y) adjacent to each other in the column direction. A black or dark light absorption layer (light shielding layer) 2 is formed.

  Further, a dielectric layer 3 is formed on the back surface of the front glass substrate 1 so as to cover the row electrode pair (X, Y), and adjacent row electrode pairs are formed on the back surface of the dielectric layer 3. Raised to protrude toward the back side of the dielectric layer 3 at a position facing the bus electrodes Xb and Yb adjacent to each other (X, Y) back to back and a position facing the region between the adjacent bus electrodes Xb and Yb. Dielectric layer 3A is formed to extend in parallel with bus electrodes Xb and Yb.

  A thin magnesium oxide layer (hereinafter referred to as a thin film magnesium oxide layer) 4 formed by vapor deposition or sputtering is formed on the back side of the dielectric layer 3 and the raised dielectric layer 3A. The entire back surface of the layer 3 and the raised dielectric layer 3A is covered.

  On the back side of the thin-film magnesium oxide layer 4, a cathode having a peak in a wavelength range of 200 to 300 nm (particularly in the vicinity of 235 nm and 230 to 250 nm) when excited by an electron beam, as will be described in detail later. A magnesium oxide layer (hereinafter referred to as a crystalline magnesium oxide layer) 5 containing a magnesium oxide crystal that emits luminescence (CL emission) is formed.

  The crystalline magnesium oxide layer 5 is formed on the entire back surface of the thin film magnesium oxide layer 4 or a part thereof, for example, a portion facing a discharge cell described later (in the illustrated example, the crystalline magnesium oxide layer 5 is thin film oxidized. An example in which it is formed on the entire back surface of the magnesium layer 4 is shown).

  On the other hand, on the display side surface of the rear glass substrate 6 arranged in parallel with the front glass substrate 1, the column electrode D is connected to the transparent electrodes Xa and Ya that are paired with each other in each row electrode pair (X, Y). They are arranged in parallel at predetermined intervals so as to extend in a direction (column direction) orthogonal to the row electrode pair (X, Y) at the opposing positions.

  A white column electrode protective layer (dielectric layer) 7 covering the column electrode D is further formed on the display side surface of the rear glass substrate 6, and a partition wall 8 is formed on the column electrode protective layer 7. Has been.

  The partition wall 8 includes a pair of horizontal walls 8A extending in the row direction at positions facing the bus electrodes Xb and Yb of each row electrode pair (X, Y), and a pair of horizontal walls 8A at an intermediate position between adjacent column electrodes D. The vertical walls 8B extending in the column direction are formed in a substantially ladder shape, and each partition wall 8 sandwiches a gap SL extending in the row direction between the lateral walls 8A of the other adjacent partition walls 8 facing each other back to back. And they are arranged side by side in the column direction.

  The ladder-shaped partition wall 8 causes the discharge space S between the front glass substrate 1 and the rear glass substrate 6 to face the transparent electrodes Xa and Ya that are paired with each other in each row electrode pair (X, Y). Each discharge cell C formed in the portion is divided into squares.

  A phosphor layer 9 is formed on the side surfaces of the horizontal and vertical walls 8A and 8B of the partition wall 8 facing the discharge space S and the surface of the column electrode protective layer 7 so as to cover all of these five surfaces. The color of the body layer 9 is arranged so that the three primary colors of red, green, and blue are arranged in order in the row direction for each discharge cell C.

  The raised dielectric layer 3A is formed only on the portion of the crystalline magnesium oxide layer 5 (or the portion where the crystalline magnesium oxide layer 5 faces the discharge cell C on the back surface of the thin-film magnesium oxide layer 4) covering the raised dielectric layer 3A. In this case, the thin-film magnesium oxide layer 4) is brought into contact with the display side surface of the lateral wall 8A of the partition wall 8 (see FIG. 2), thereby closing the space between the discharge cell C and the gap SL. However, it is not in contact with the display side surface of the vertical wall 8B (see FIG. 3), and a gap r is formed between them, and the discharge cells C adjacent in the row direction are mutually connected via this gap r. It is communicated.

  In the discharge space S, a discharge gas containing xenon gas is enclosed.

  The crystalline magnesium oxide layer 5 is composed of the thin-film magnesium oxide layer 4 in which the magnesium oxide crystal as described above covers the dielectric layer 3 and the raised dielectric layer 3A by a method such as spraying or electrostatic coating. It is formed by being attached to the surface on the back side.

  In this embodiment, the thin film magnesium oxide layer 4 is formed on the back surface of the dielectric layer 3 and the raised dielectric layer 3A, and the crystalline magnesium oxide layer 5 is formed on the back surface of the thin film magnesium oxide layer 4. As will be described, after the crystalline magnesium oxide layer 5 is formed on the back surface of the dielectric layer 3 and the raised dielectric layer 3A, the thin film magnesium oxide layer 4 is formed on the back surface of the crystalline magnesium oxide layer 5. May be.

  In FIG. 4, a thin film magnesium oxide layer 4 is formed on the back surface of the dielectric layer 3, and a magnesium oxide crystal is attached to the back surface of the thin film magnesium oxide layer 4 by a method such as spraying or electrostatic coating. The state in which the magnesium oxide layer 5 is formed is shown.

  Further, FIG. 5 shows that after the magnesium oxide crystal is attached to the back surface of the dielectric layer 3 by a method such as spraying or electrostatic coating to form the crystalline magnesium oxide layer 5, the thin-film magnesium oxide layer 4 is formed. It shows the state being done.

  The crystalline magnesium oxide layer 5 of the PDP is formed by the following materials and methods.

  That is, a magnesium oxide crystal that emits CL having a peak in a wavelength range of 200 to 300 nm (especially in the vicinity of 235 nm and within a range of 230 to 250 nm) by being excited by an electron beam that is a material for forming the crystalline magnesium oxide layer 5; Includes, for example, a magnesium single crystal obtained by vapor phase oxidation of magnesium vapor generated by heating magnesium (hereinafter, this magnesium single crystal is referred to as a vapor phase magnesium oxide single crystal). The vapor-phase-processed magnesium oxide single crystal includes, for example, a magnesium oxide single crystal having a cubic single crystal structure as shown in the SEM photograph image of FIG. 6 and a SEM photograph image of FIG. Magnesium oxide single crystal having a structure in which cubic crystals are fitted to each other (ie, cubic multiple crystal structure) Body is included.

  As will be described later, this vapor phase magnesium oxide single crystal contributes to improvement of discharge characteristics such as reduction of discharge delay.

  The vapor-phase-processed magnesium oxide single crystal has characteristics such as high purity, fine particles, and less aggregation of particles as compared with magnesium oxide obtained by other methods.

  In this embodiment, a vapor-phase magnesium oxide single crystal having an average particle size measured by the BET method of 500 angstroms or more (preferably 2000 angstroms or more) is used.

  In addition, about the synthesis | combination of a vapor-phase-method magnesium oxide single crystal body, "Materials" November, 1987, Volume 36, No. 410, pp. 1157 to 1161, "Synthesis and properties of magnesia powder by vapor phase method". And the like.

As described above, the crystalline magnesium oxide layer 5 is formed by depositing a vapor-phase magnesium oxide single crystal by a spray method, an electrostatic coating method, or the like.
In the PDP, reset discharge, address discharge, and sustain discharge for image formation are performed in the discharge cell C.

  Then, when the reset discharge that is performed before the address discharge is generated in the discharge cell C, the priming effect by the reset discharge is sustained for a long time because the crystalline magnesium oxide layer 5 is formed in the discharge cell C. This speeds up the address discharge.

  As shown in FIGS. 8 and 9, the PDP has a crystalline magnesium oxide layer 5 formed of a vapor-phase magnesium oxide single crystal as described above. In addition to CL emission having a peak at 300 to 400 nm, from a vapor phase magnesium oxide single crystal having a large particle size contained in the crystalline magnesium oxide layer 5, within a wavelength range of 200 to 300 nm (particularly around 235 nm, 230 to CL emission having a peak within 250 nm) is excited.

  The CL emission having a peak at 235 nm is not excited from the magnesium oxide layer (thin film magnesium oxide layer 4 in this embodiment) formed by a normal vapor deposition method as shown in FIG. Only CL emission with a peak is excited.

  Further, as can be seen from FIGS. 8 and 9, CL emission having a peak in the wavelength range of 200 to 300 nm (particularly, around 235 nm and within 230 to 250 nm) increases as the particle diameter of the vapor-phase-processed magnesium oxide single crystal increases. The peak intensity increases.

  The presence of CL emission having a peak in this wavelength range of 200 to 300 nm is presumed to further improve the discharge characteristics (decrease in discharge delay and increase in discharge probability).

  That is, the improvement of the discharge characteristics by this crystalline magnesium oxide layer 5 is that a vapor phase magnesium oxide single crystal that performs CL emission having a peak in a wavelength range of 200 to 300 nm (especially in the vicinity of 235 nm, within 230 to 250 nm) It has an energy level corresponding to the peak wavelength, and can trap electrons for a long time (several milliseconds or more) by the energy level, and the electrons are taken out by an electric field, so that the initial electrons necessary for starting discharge It is assumed that this is done by obtaining

  And the improvement effect of the discharge characteristic by this vapor phase method magnesium oxide single crystal increases as the intensity of CL emission having a peak in the wavelength range of 200 to 300 nm (especially in the vicinity of 235 nm and within 230 to 250 nm) increases. This is because there is a correlation between the CL emission intensity and the particle diameter of the vapor-phase-process magnesium oxide single crystal.

  That is, when a vapor phase magnesium oxide single crystal having a large particle size is to be formed, it is necessary to increase the heating temperature when generating magnesium vapor, so the length of the flame in which magnesium and oxygen react As the temperature difference between the flame and the surroundings increases, the vapor phase magnesium oxide single crystal having a larger particle size has a peak wavelength of CL emission as described above (for example, around 235 nm, within 230 to 250 nm). It is thought that many energy levels corresponding to () are formed.

  In addition, the cubic multicrystal structure vapor phase magnesium oxide single crystal has many crystal plane defects, and it is speculated that the existence of the plane defect energy level contributes to the improvement of the discharge probability. .

The particle diameter (D _BET ) of the vapor-phase method magnesium oxide single crystal forming the crystalline magnesium oxide layer 5 is calculated by the following equation from the BET specific surface area (s) measured by the nitrogen adsorption method. .

D _BET = A / s × ρ
A: Shape counting (A = 6)
ρ: True density of magnesium FIG. 11 is a graph showing a correlation between CL emission intensity and discharge delay.

  From FIG. 11, it can be seen that the CL emission of 235 nm excited from the crystalline magnesium oxide layer 5 shortens the discharge delay in the PDP. Furthermore, the stronger the emission intensity of CL at 235 nm, the shorter the discharge delay. I understand that

  FIG. 12 shows a case where the PDP has a two-layer structure of the thin film magnesium oxide layer 4 and the crystalline magnesium oxide layer 5 as described above (graph a), and magnesium oxide formed by vapor deposition as in the conventional PDP. This is a comparison of the discharge delay characteristics when only the layer is formed (graph b).

  As can be seen from FIG. 12, since the PDP has a two-layer structure of the thin film magnesium oxide layer 4 and the crystalline magnesium oxide layer 5, the discharge delay characteristic is limited to the thin film magnesium oxide layer formed by the conventional vapor deposition method. It can be seen that it is remarkably improved as compared with the PDP provided with.

  As described above, in addition to the conventional thin film magnesium oxide layer 4 formed by a vapor deposition method or the like, the PDP is oxidized by performing CL emission having a peak in a wavelength range of 200 to 300 nm when excited by an electron beam. By forming the crystalline magnesium oxide layer 5 containing the magnesium crystal layer, the discharge characteristics such as the discharge delay can be improved, and good discharge characteristics can be provided.

  As the magnesium oxide crystal forming the crystalline magnesium oxide layer 5, those having an average particle diameter measured by the BET method of 500 angstroms or more are used, preferably those having a diameter of 2000 to 4000 angstroms.

  As described above, the crystalline magnesium oxide layer 5 is not necessarily formed so as to cover the entire surface of the thin-film magnesium oxide layer 4. For example, the portions of the row electrodes X and Y facing the transparent electrodes Xa and Ya, or conversely transparent It may be formed by partially patterning, such as a portion other than the portion facing the electrodes Xa and Ya.

  When this crystalline magnesium oxide layer 5 is partially formed, the area ratio of the crystalline magnesium oxide layer 5 to the thin-film magnesium oxide layer 4 is set to 0.1 to 85 percent, for example.

  In the above description, the present invention is applied to a reflective AC PDP in which a row electrode pair is formed on a front glass substrate and covered with a dielectric layer, and a phosphor layer and a column electrode are formed on the back glass substrate side. As described above, the present invention is a reflective AC PDP in which a row electrode pair and a column electrode are formed on the front glass substrate side and covered with a dielectric layer, and a phosphor layer is formed on the rear glass substrate side. A transmissive AC PDP in which a phosphor layer is formed on the glass substrate side, a row electrode pair and a column electrode are formed on the back glass substrate side, and is covered with a dielectric layer, discharge occurs at the intersection of the row electrode pair and the column electrode in the discharge space The present invention can be applied to various types of PDPs such as a three-electrode AC PDP in which cells are formed and a two-electrode AC PDP in which discharge cells are formed at intersections between row electrodes and column electrodes in the discharge space.

  Further, in the above description, an example in which the crystalline magnesium oxide layer 5 is formed by adhering by a method such as spraying or electrostatic coating has been described. However, the crystalline magnesium oxide layer 5 is a powder of magnesium oxide crystal. May be formed by coating by a screen printing method or an offset printing method, a dispenser method, an ink jet method, a roll coating method or the like, or a paste containing a magnesium oxide crystal It may be formed into a film by drying after coating on the support film, and this may be laminated on the thin magnesium oxide layer.

It is a front view which shows the Example of embodiment of this invention. It is sectional drawing in the VV line of FIG. It is sectional drawing in the WW line of FIG. It is sectional drawing which shows the state in which the crystalline magnesium layer is formed on the thin film magnesium layer in the Example. It is sectional drawing which shows the state in which the thin film magnesium layer is formed on the crystalline magnesium layer in the Example. It is a figure which shows the SEM photograph image of the magnesium oxide single crystal which has a cubic single crystal structure. It is a figure which shows the SEM photograph image of the magnesium oxide single crystal which has a cubic multiple crystal structure. It is a graph which shows the relationship between the particle size of a magnesium oxide single crystal body, and the wavelength of CL light emission in the Example. It is a graph which shows the relationship between the particle size of a magnesium oxide single crystal body and the intensity | strength of CL light emission of 235 nm in the Example. It is a graph which shows the state of the wavelength of CL light emission from the magnesium oxide layer by a vapor deposition method. It is a graph which shows the relationship between the peak intensity of CL light emission of 235 nm from a magnesium oxide single crystal body, and discharge delay. It is a figure which shows the comparison of the discharge delay characteristic with the case where the protective layer is comprised only by the magnesium oxide layer by a vapor deposition method, and the case where it has the double layer structure of the crystalline magnesium layer and the thin film magnesium layer by a vapor deposition method.

Explanation of symbols

1 ... Front glass substrate (front substrate)
3 ... Dielectric layer 4 ... Thin film magnesium oxide layer 5 ... Single crystal magnesium oxide layer 6 ... Back glass substrate (back substrate)
7 ... Column electrode protective layer (dielectric layer)
C ... discharge cell X, Y ... row electrode (discharge electrode)
D: Column electrode (discharge electrode)

Claims (12)

A front substrate and a rear substrate facing each other through a discharge space, a discharge electrode formed on at least one of the front substrate and the rear substrate, a dielectric layer covering the discharge electrode, and the dielectric layer In a plasma display panel having a protective layer covering
The protective layer includes a thin-film magnesium oxide layer formed by vapor deposition or sputtering, and a particulate magnesium oxide crystal that emits cathode luminescence having a peak in a wavelength range of 200 to 300 nm when excited by an electron beam. A crystal magnesium oxide layer containing a layered structure,
The thin film magnesium oxide layer is formed on the dielectric layer, and the crystalline magnesium oxide layer is formed on the thin film magnesium oxide layer.
A plasma display panel characterized by that. The plasma display panel according to claim 1, wherein the magnesium oxide crystal includes crystal plane defects.   The plasma display panel according to claim 1, wherein the magnesium oxide crystal emits cathode luminescence having a peak within 230 to 250 nm.   The plasma display panel according to claim 1, wherein the magnesium oxide crystal is a magnesium oxide single crystal produced by a gas phase oxidation method.   The plasma display panel according to claim 1, wherein the magnesium oxide crystal has a particle size of 500 angstroms or more.   The plasma display panel according to claim 1, wherein the magnesium oxide crystal has a particle size of 2000 angstroms or more.   The plasma display panel according to claim 1, wherein the magnesium oxide crystal is exposed to a discharge space.   The plasma display panel according to claim 1, wherein the crystalline magnesium oxide layer and the thin-film magnesium oxide layer are respectively formed on the entire surface of the dielectric layer.   The plasma display panel according to claim 1, wherein the thin-film magnesium oxide layer is formed on the entire surface of the dielectric layer, and the crystalline magnesium oxide layer is formed at a position facing a part of the surface of the dielectric layer.   The plasma display panel according to claim 9, wherein the crystalline magnesium oxide layer is formed in a portion facing the discharge electrode.   The plasma display panel according to claim 9, wherein the crystalline magnesium oxide layer is formed in a portion other than a portion facing the discharge electrode. A front substrate and a rear substrate opposed via a discharge space, a discharge electrode formed on at least one of the front substrate and the rear substrate, a dielectric layer covering the discharge electrode, and the dielectric A method for manufacturing a plasma display panel having a protective layer formed on a layer and covering a dielectric layer,
The step of forming the protective layer includes a step of forming a thin-film magnesium oxide layer by vapor deposition or sputtering, and a particulate luminescent emission having a peak in a wavelength range of 200 to 300 nm when excited by an electron beam. Forming a crystalline magnesium oxide layer containing magnesium oxide crystals,
After the step of forming the thin film magnesium oxide layer is performed, the step of forming the crystalline magnesium oxide layer is performed.
A method of manufacturing a plasma display panel.