JP2008041608A - Plasma display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a plasma display panel excellent in display characteristics without damages of a gap regulation member, with a uniform thickness of a sealing layer, and without non-lighting or barrier rib damages of discharge cells. <P>SOLUTION: The plasma display panel is provided with a front substrate and a back substrate 9 arranged in opposition and its peripheral part with the front substrate and the back substrate is airtightly sealed by a sealing layer. The sealing layer is structured of a sealing member 16 and a gap regulation member 60 mixed in the sealing member 16, and the specific gravity of the gap regulation member 60 is larger than that of the sealing member 16. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plasma display panel known as a large screen, thin and light image display device.

  In recent years, plasma display panels (hereinafter referred to as “PDP” or “panel”) have attracted attention as display panels (thin display devices) with excellent visibility.

  This PDP is broadly divided into AC and DC types, and there are two types of discharge types, surface discharge type and counter discharge type. However, because of high definition, large screen, and easy manufacturing, At present, AC type and surface discharge type PDPs have come to dominate.

  In this PDP structure, a front substrate having a plurality of display electrodes composed of scan electrodes and sustain electrodes and a rear substrate having a plurality of data electrodes are opposed to each other with a partition wall interposed therebetween so that the display electrodes and the data electrodes are orthogonal to each other. It has been made. The outer peripheral portion of the PDP is sealed with a sealing (sealing) layer. A phosphor layer is formed in the discharge space partitioned by the barrier ribs, and a discharge gas is sealed in the discharge space.

  The intersection between the display electrode and the data electrode functions as a discharge cell (unit light emitting region). A voltage is applied between the display electrode and the data electrode to generate a discharge. The body layer is irradiated with visible light to display an image.

  In the PDP having the configuration described above, for the purpose of sealing the front substrate and the back substrate in the manufacturing process, for example, a seal member mainly composed of a low melting glass material is applied and formed on the outer periphery of the back substrate. Yes. In order to apply the sealing member to the back substrate, a low melting point glass material, a solvent, and a binder resin are mixed at a predetermined ratio to form a seal paste, which is applied or drawn on the outer peripheral portion of the back substrate by a dispenser method or a printing method. . Further, the seal paste drawn on the back substrate is dried to volatilize the solvent component, and the seal member is solidified on the back substrate by the binder resin. Next, the binder resin is burned out in a baking step of about 300 ° C. to 500 ° C., and at the same time, the low-melting glass material is softened and fixed on the back substrate.

  Thus, the front substrate and the rear substrate are arranged opposite to each other at a predetermined position through the seal member formed on the rear substrate, and the outer peripheral portions of both substrates are fixed by a fastening jig such as a clip.

  In the next sealing step, the sealing member is heated to the softening temperature, and the softened low melting point glass material is expanded by the pressing force of the clip. The distance (gap) between the two substrates is regulated by the height of the partition wall formed on the back substrate, and is sealed by a low-melting glass material re-hardened by cooling.

The panel hermetically sealed by sealing is heated and evacuated to discharge impurity gases such as H ₂ O and CO ₂ adsorbed on the panel components to the outside of the panel. In this vacuum evacuation process, the adsorbed impurity gas is heated at a high temperature in order to desorb it from the panel components. At that time, when the seal member is re-softened, the air between the partition wall and the seal member is exhausted to be evacuated, so that it is pressed by the atmospheric pressure from the outside of the panel and the thickness of the seal layer is reduced. In the PDP manufactured in this way, a gap is generated between the curved front substrate and the partition wall on the rear substrate, and this gap causes audible noise caused by discharge crosstalk or vibration of the front substrate and the rear substrate. This causes the panel quality to deteriorate.

In order to deal with such a problem, an example is disclosed in which granular beads serving as a gap regulating member for making the gap of the sealing layer constant in the sealing member are mixed to regulate the thickness of the sealing layer ( For example, see Patent Document 1).
JP 2001-236896 A

  However, in these conventional methods, when a sealing member mixed with granular beads serving as a gap regulating member is applied or drawn on the back substrate, the granular beads sometimes blow off from the coating film surface of the sealing member. When the granular beads are lifted off the surface of the coating film of the sealing member, the state is maintained even when the coating film is dried and the sealing member is baked and softened, and when the front substrate and the rear substrate are sealed by pressing with a clip or the like. In other words, an excessive pressing force is applied to the bead and the bead is destroyed. As a result, there are problems such as debris due to bead breakage scattering into the display area, causing discharge cell unlighting phenomenon and partition wall breakage.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to obtain a PDP excellent in display characteristics without a gap-regulating member being destroyed, a seal layer having a uniform thickness, no discharge cell non-lighting and partition wall destruction.

  In order to achieve the above object, a PDP according to the present invention is a PDP in which a front substrate and a back substrate are arranged to face each other and an outer peripheral portion of the front substrate and the back substrate is hermetically sealed with a seal layer. Is constituted by a seal member and a gap regulating member mixed in the seal member, and the specific gravity of the gap regulating member is larger than the specific gravity of the seal member.

  According to such a configuration, the gap regulating member settles and falls in the seal layer and is securely disposed in the seal layer, so that the gap regulation of the seal layer is surely performed and the destruction of the gap regulating member is prevented. A PDP having good display characteristics can be obtained.

  Furthermore, it is desirable that the softening point of the gap regulating member is higher than the softening point of the sealing member, and when the sealing member is softened, the shape of the gap regulating member can be held and the gap of the sealing layer can be held with high accuracy.

  Furthermore, it is desirable that the gap regulating member is spherical, and the gap accuracy by the gap regulating member can be maintained with high accuracy.

  Furthermore, the specific gravity of the gap regulating member is preferably a specific gravity that drops and settles in the softened seal member, and the gap regulating member can be prevented from protruding from the seal layer when the seal member is softened.

  According to the PDP of the present invention, the gap regulation of the seal layer can be reliably performed, the breakage of the gap regulating member can be prevented, and a PDP with good display characteristics can be obtained.

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

(Embodiment)
The configuration and characteristics of the PDP according to the embodiment of the present invention will be described with reference to FIGS. First, the main configuration of the PDP of the present invention will be described with reference to FIGS.

  1 is a sectional perspective view showing a schematic configuration of a PDP according to an embodiment of the present invention, FIG. 2 is a sectional view of the PDP, FIG. 3 is a plan view showing a schematic configuration of an image display region of the PDP, and FIG. It is a block diagram which shows the structure of the plasma image display apparatus using PDP by invention.

  In FIG. 1, the PDP 1 is composed of a front substrate 2 and a rear substrate 9, and the front substrate 2 and the rear substrate 9 are arranged to face each other so as to form a discharge space 17. The front substrate 2 is formed with a plurality of stripe-shaped display electrodes 6 that are paired with a scanning electrode 4 and a sustaining electrode 5 on a front glass substrate 3 such as sodium borosilicate glass by a float method. A black stripe 21 serving as a light shielding portion is formed between the adjacent display electrodes 6. A front dielectric layer 7 is formed so as to cover the display electrode 6 and the black stripe 21, and a protective layer 8 made of magnesium oxide (MgO) is further formed so as to cover the front dielectric layer 7.

  On the other hand, in the rear substrate 9, a data electrode 11 is formed on the rear glass substrate 10 in a direction orthogonal to the display electrode 6 of the front substrate 2, and a base rear dielectric layer 12 is provided so as to cover the data electrode 11. For example, a stripe-shaped partition wall 13 is provided on the base back dielectric layer 12, and a phosphor layer 14 is provided on the side surface of the partition wall 13 and the surface of the base back dielectric layer 12. The phosphor layer 14 has a red phosphor layer 14R that emits red light, a green phosphor layer 14G that emits green light, and a blue phosphor layer 14B that emits blue light in order in a discharge space 17 partitioned by adjacent barrier ribs 13. Is formed.

  FIG. 2 is a partial cross-sectional view showing the main configuration of the front substrate 2 and the rear substrate 9 disposed opposite thereto. Scan electrode 4 and sustain electrode 5 are configured by transparent electrodes 4a and 5a and bus electrodes 4b and 5b, respectively. The bus electrodes 4b and 5b are made of a material such as Cr / Cu / Cr or Ag, and are electrically connected to the transparent electrodes 4a and 5a, respectively.

  The front substrate 2 and the back substrate 9 described above are arranged opposite to each other with the partition wall 13 interposed therebetween so that the display electrode 6 and the data electrode 11 are orthogonal to each other and form a minute discharge space 17 inside, and the periphery is sealed with a sealing member 16. (Not shown). The discharge space 17 is partitioned by the barrier ribs 13, and a rectangular region centering on a portion where the display electrode 6 and the data electrode 11 are orthogonal to each other constitutes a discharge cell 18 as a unit light emitting region. In FIG. 1, the arrow direction is the display direction. Thereafter, the discharge space 17 is filled with a discharge gas mixed with Ne and Xe at a pressure of about 66500 Pa (500 Torr) to complete the PDP 1.

  Further, as shown in FIG. 3, the front substrate 2 of the PDP 1 has a display electrode composed of N scan electrodes 4 and N sustain electrodes 5 formed on one main surface of a front glass substrate 3 (not shown). 6 (the number is attached when the Nth is shown), and the back substrate 9 has M data electrodes 11 formed on one main surface of the rear glass substrate 10 (the number when the Mth is shown). Are attached). The front substrate 2 and the back substrate 9 are sealed around the outside of the image display region 15 by a seal member 16.

  Further, as shown in FIG. 4, the PDP driving device 31 includes a controller 32, a sustain driver circuit 33, a scan driver circuit 34, and a data driver circuit 35. When the plasma image display device 30 is driven, the PDP 1 has a sustain driver circuit 33. The scan driver circuit 34 and the data driver circuit 35 are connected, and address discharge is performed by applying a voltage between the scan electrode 4 and the data electrode 11 in the discharge cell 18 to be lit according to the control of the controller 32. Thereafter, a sustain discharge is performed by applying a voltage between scan electrode 4 and sustain electrode 5. By this sustain discharge, ultraviolet rays are generated in the discharge cell 18, and the red phosphor layer 14R, the green phosphor layer 14G, and the blue phosphor layer 14B excited by the ultraviolet rays are lit to emit light, and the discharge cells of the respective colors. A color image is displayed by a combination of 18 lighting and non-lighting.

Next, a method for manufacturing the PDP in the embodiment of the present invention will be described. In the front substrate 2, transparent electrodes 4 a and 5 a are first formed on the front glass substrate 3, and bus electrodes 4 b and 5 b are stacked thereon to form the scan electrodes 4 and the sustain electrodes 5. Further, the front dielectric layer 7 is coated thereon, and a protective layer 8 made of MgO material is formed on the surface of the front dielectric layer 7. The transparent electrodes 4a and 5a are formed of a transparent conductive material such as ITO or tin oxide (SnO ₂ ). The bus electrodes 4b and 5b are made of a metal material, and are a silver (Ag) thick film (thickness: 2 μm to 10 μm), an aluminum (Al) thin film (thickness: 0.1 μm to 1 μm), or Cr / Cu / Cr. A laminated thin film (thickness: 0.1 μm to 1 μm) is patterned by screen printing, photolithography or the like.

The front dielectric layer 7 is formed to have a predetermined layer thickness (about 40 μm) by applying a paste containing a glass material by screen printing and firing at a predetermined temperature and time (for example, 560 ° C. for 20 minutes). To do. Examples of the paste containing a glass material include PbO (70 wt%), B ₂ O ₃ (15 wt%), SiO ₂ (10 wt%), Al ₂ O ₃ (5 wt%), and an organic binder (10 to α-terpineol). % Ethylcellulose) is used. The organic binder is obtained by dissolving a resin in an organic solvent. In addition to ethyl cellulose, an acrylic resin can be used as the resin, and butyl carbitol can be used as the organic solvent. Furthermore, you may mix a dispersing agent (for example, glyceryl trioleate) in such an organic binder.

  The protective layer 8 is for protecting the front dielectric layer 7 from plasma damage, and is made of, for example, magnesium oxide (MgO), and has a predetermined thickness (about 0) by sputtering or CVD (chemical vapor deposition). .5 μm).

  On the other hand, the back substrate 9 is formed in a state in which M data electrodes 11 are arranged on the back glass substrate 10, and further, a base back dielectric layer 12 is formed so as to cover the data electrodes 11. Thereafter, the barrier ribs 13 are formed at positions corresponding to the data electrodes 11 on the base back dielectric layer 12, and the red phosphor layer 14R, the green phosphor layer 14G, and the blue phosphor layer 14B are formed between the barrier ribs 13. .

  The data electrode 11 is made of a metal material, and is a silver (Ag) thick film (thickness: 2 μm to 10 μm), an aluminum (Al) thin film (thickness: 0.1 μm to 1 μm), or a Cr / Cu / Cr laminated thin film (thickness). : 0.1 [mu] m to 1 [mu] m) is formed by screen printing or photolithography.

The base back dielectric layer 12 is formed by applying a low melting point glass paste mainly composed of lead oxide (PbO), bismuth oxide (Bi ₂ O ₃ ) or phosphorus oxide (PO ₄ ) by a screen printing method. It forms in 5 micrometers-20 micrometers. The partition wall 13 is formed to have a height of about 80 μm to 140 μm by repeatedly applying a paste containing a lead-based glass material at a predetermined pitch by, for example, a screen printing method, like the base back dielectric layer 12.

The red phosphor layer 14R, the green phosphor layer 14G, and the blue phosphor layer 14B are obtained by mixing vehicles with powders of a red phosphor material (R), a green phosphor material (G), and a blue phosphor material (B), respectively. The paste-like material is applied between the barrier ribs 13 by, for example, an ink discharge method, and then fired at a temperature of 400 ° C. to 590 ° C. to burn off the organic vanida, whereby the phosphor material particles are bound. Form. As a phosphor material of a general PDP, (Y _X Gd _1-X ) BO ₃ : Eu ³⁺ or YBO ₃ : Eu ^{3+ as} a red phosphor, Zn ₂ SiO ₄ : Mn as a green phosphor, and blue phosphor BaMgAl ₁₀ O ₁₇ : Eu ²⁺ is used.

  Next, the sealing member 16 made of a low melting point glass material is mixed with an organic binder or the like and pasted on the outer peripheral portion of the back substrate 9 to form a sealing layer by dispensing. Thereafter, firing is performed at a temperature of about 300 ° C. to 400 ° C. for the purpose of burning off the organic binder contained in the seal layer.

  The front substrate 2 and the rear substrate 9 produced as described above are arranged so as to face each other so that the display electrodes 6 of the front substrate 2 and the data electrodes 11 of the rear substrate 9 are orthogonal to each other (alignment), Sealing is performed by a sealing member 16 formed around the outside of the image display area 15.

  FIG. 5 is a plan view showing a state of a general PDP sealing process. As shown in FIG. 5, in the sealing process, images of the front substrate 2 and the rear substrate 9 arranged to face each other at predetermined positions are shown. In a state where the outer peripheral portion of the display area 15 is fixed with the clip 53 or the like, the sealing member 16 is softened by baking at a temperature of about 450 ° C. for 10 minutes to 20 minutes, and then cooled to complete the sealing. FIG. 6 is a cross-sectional view showing the sealing process, showing a state in which the front glass substrate 3 of the front substrate 2 and the rear glass substrate 10 of the rear substrate 9 are pressed while being fixed by the clip 53. Yes. As shown in FIG. 6, the height of the front substrate 2 and the rear substrate 9 is defined by the partition wall 13 after sealing, and the gap gap is required to be uniform over the entire region.

  Further, the inside of the PDP is evacuated from the exhaust holes 52 formed in at least one of the four corners shown in FIG. 5 through an exhaust pipe by an external exhaust device, cooled to room temperature, and then filled with a discharge gas to a predetermined pressure. The PDP is completed by sealing the tube.

  Next, a method for sealing the front substrate 2 and the rear substrate 9 with the seal member 16 will be described in detail. FIG. 7 is a cross-sectional view showing a state in which the sealing member 16 is formed on the back substrate 9 in the PDP according to the embodiment of the present invention. 7A shows a state after applying the seal paste, and FIG. 7B shows a state in which the seal member 16 is melted and softened. However, in FIG. 7B, the front substrate and the like are omitted for easy understanding of the state.

  A seal paste is applied and drawn on at least one of the front substrate 2 and the back substrate 9 created as described above, for example, the outer peripheral portion of the back substrate 9. As a forming method, patterning by screen printing or direct coating formation on a substrate by a dispenser or the like is generally used. The seal paste to be applied is composed of a low-melting glass material that is the seal member 16, a gap regulating member 60 that regulates the gap distance between the front substrate 2 and the back substrate 9, a solvent, and a resin binder. As shown in FIG. 7A, the seal paste applied on the back substrate 9 is dried for the purpose of volatilization and removal of the solvent, and solidified on the back substrate 9 by the effect of the resin binder. Thereafter, a baking step of 300 ° C. to 500 ° C. is performed in order to burn off the resin binder. In this firing step, in order to soften the low melting point glass material as the sealing member 16 and fix it to the back substrate 9, it is necessary to heat at a temperature higher than the softening temperature of the low melting point glass material. The firing temperature is determined by the softening temperature of the material.

  In the present invention, the gap regulating member 60 uses an inorganic material or a metal material such as an oxide material having a specific gravity larger than that of the low melting point glass material that is the sealing member 16. In this firing step, when the seal member 16 is softened, the gap regulating member 60 has a specific gravity greater than that of the seal member 16, so that it does not float on the surface of the seal member 16 as shown in FIG. Then, it sinks into the seal member 16 and settles down on the surface of the back substrate 9.

  FIG. 8 is a view showing an example in which a conventional gap regulating member 70 is mixed in the seal member 71. Even when the seal member 71 is melted and softened, the gap regulating member 70 has a small specific gravity, so that the gap regulating member 70 is small. Is raised to the surface of the seal member 71. Therefore, when the seal member 71 is solidified while being pressed with a clip or the like, there is a problem that the gap regulating member 70 is broken and scattered in the display area to deteriorate the image display quality.

  As shown in FIG. 7B, the front substrate 2 and the rear substrate 9 are clipped 53 as shown in FIG. 5 in a state where the gap regulating member 60 is settled and dropped on the surface of the rear substrate 9 as the seal member 16. Press to fix. At that time, since the gap regulating member 60 is not exposed on the surface of the seal member 16, the gap regulating member 60 is broken by the pressing force of the clip 53 when the seal member 16 is solidified and sealed. There is no problem of peeling off.

  The sealed panel is heated while evacuating the internal space in the next evacuation step. The vacuum exhaust is performed by an external exhaust device through an exhaust pipe from an exhaust hole 52 formed in at least one of the substrates. Even if the internal space is heated in a vacuum state and the sealing member 16 is softened again, the gap regulating member 60 is present, so that the thickness of the sealing layer is reduced and the gap at the end portion is reduced. Therefore, the gap between the front substrate 2 and the rear substrate 9 can be kept constant over the entire area of the PDP.

  In the present invention, the gap regulating member 60 is spherical. Therefore, the gap accuracy by the gap regulating member 60 can be maintained with high accuracy.

  In the above embodiment, the PDP is exemplified, but the front substrate and the rear substrate can be hermetically sealed, and can be applied to all display panels having a sealing process.

  According to the PDP of the present invention, the gap regulation of the seal layer is surely performed, the destruction of the gap regulating member is prevented, and a display panel with good display characteristics can be obtained, which is useful for a display panel with a large area. is there.

Sectional perspective view which shows schematic structure of PDP in embodiment of this invention Sectional drawing which shows schematic structure of the PDP The top view which shows schematic structure of the image display area of the PDP The block diagram which shows schematic structure of the plasma image display apparatus using the same PDP The top view which shows the state of the general sealing process of PDP Sectional drawing which shows the state of the general sealing process of PDP Sectional drawing which shows the state which formed the sealing member in the back substrate in PDP in embodiment of this invention. Sectional drawing which shows the state which formed the sealing member of the state which mixed the conventional gap control member in the sealing member

Explanation of symbols

1 PDP
DESCRIPTION OF SYMBOLS 2 Front substrate 3 Front glass substrate 4 Scan electrode 4a, 5a Transparent electrode 4b, 5b Bus electrode 5 Sustain electrode 6 Display electrode 7 Front dielectric layer 8 Protective layer 9 Back substrate 10 Back glass substrate 11 Data electrode 12 Base back dielectric layer DESCRIPTION OF SYMBOLS 13 Partition 14 Phosphor layer 14R Red phosphor layer 14G Green phosphor layer 14B Blue phosphor layer 15 Image display area 16, 71 Seal member 17 Discharge space 18 Discharge cell 21 Black stripe 30 Plasma image display device 31 PDP drive device 32 Controller 33 maintenance driver circuit 34 scan driver circuit 35 data driver circuit 52 exhaust hole 53 clip 60, 70 gap regulating member

Claims (4)

A plasma display panel in which a front substrate and a back substrate are arranged to face each other and an outer periphery of the front substrate and the back substrate is hermetically sealed with a seal layer, and the seal layer is mixed in the seal member and the seal member A plasma display panel comprising: a gap regulating member, wherein the specific gravity of the gap regulating member is greater than the specific gravity of the seal member. The plasma display panel according to claim 1, wherein a softening point of the gap regulating member is higher than a softening point of the seal member. The plasma display panel according to claim 2, wherein the gap regulating member is spherical. 4. The plasma display panel according to claim 1, wherein the specific gravity of the gap regulating member is a specific gravity that drops and sinks in the softened seal member. 5.

Images