JP2008091253A - Image display device and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device which can maintain high display performance for a long period, and to provide a manufacturing method therefor for reducing the manufacturing cost. <P>SOLUTION: The image display device includes an enclosing unit 10 having a front board 11 and a rear board 12 placed opposite to the front board 11, and a nonvaporizing getter placed inside the enclosing unit 10; and according to the manufacturing method for the image display device, a nonvaporizing getter member 23 is made out of powder of nonvaporizing getter and a metal alkoxide in the enclosing unit 10, and the metal alkoxide is heated to fix the powder of nonvaporizing getter to the inside of the enclosing unit 10. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing an image display apparatus including an envelope having substrates disposed opposite to each other and a getter provided inside the envelope, and an image forming apparatus.

  In recent years, as a lightweight and thin image display device, a liquid crystal display (hereinafter referred to as LCD) that controls the intensity of light using the orientation of liquid crystal, a plasma display panel (hereinafter referred to as LCD) that emits phosphors by ultraviolet rays of plasma discharge. (Referred to as PDP), field emission display (hereinafter referred to as FED) that emits a phosphor with an electron beam of a field emission electron emitter, and surface conduction electron that emits a phosphor with an electron beam of a surface conduction electron emitter. Emission displays (hereinafter referred to as SEDs) have been developed.

  For example, an FED generally has a front substrate and a rear substrate that are opposed to each other with a predetermined gap, and these substrates are surrounded by a vacuum by surrounding each other through a rectangular frame-shaped side wall. Make up the vessel. A phosphor screen is formed on the inner surface of the front substrate, and a number of electron-emitting devices are provided on the inner surface of the rear substrate as electron emission sources that excite the phosphor to emit light.

  In order to support an atmospheric pressure load applied to the back substrate and the front substrate, a plurality of support members are disposed between these substrates. The potential on the back substrate side is almost the ground potential, and 10 kV, for example, is applied as an anode voltage to the phosphor screen. An image is displayed by irradiating the phosphors of red, green, and blue constituting the phosphor screen with the electron beams emitted from the electron-emitting devices and causing the phosphors to emit light.

  In such an FED, it is important to maintain a high degree of vacuum inside the envelope. If the degree of vacuum is low, stable electron emission cannot be performed, and the life of the image display device is reduced. Further, in PDP, it is an important technique to keep the inert gas filling the inside of the envelope with high purity.

In order to maintain a high vacuum in the envelope for a long period of time, a getter material that adsorbs the released gas is provided in the envelope and plays an important role. Conventionally, in order to improve the gas adsorption characteristics of the getter material, the getter material is deposited on the inner surface of the front substrate or the rear substrate or other structure in a vacuum processing apparatus, and both the substrates are sealed in a vacuum. A manufacturing method and a manufacturing apparatus for an image display device forming an envelope have been proposed (see, for example, Patent Document 1). For example, a method of forming a non-evaporable getter layer in a region adjacent to the panel side of the PDP has been proposed (see, for example, Patent Document 2).
JP 2001-229824 A JP-A-11-191378

  In the method of forming a getter film and sealing an envelope in a vacuum processing apparatus, undesired gas molecules are efficiently adsorbed on the getter film. For this reason, the inside of the vacuum envelope of the FED is maintained at a high degree of vacuum over a long period of time.

  However, since this method uses a large vacuum processing apparatus, the manufacturing cost increases, and as a result, the cost of the image display apparatus also increases. When an evaporative getter film is deposited over the entire surface of the phosphor screen, there is a problem in performance that the luminance is lowered. In addition, when a getter film is provided over the electron-emitting device and the wiring provided on the back substrate side, the breakdown voltage is deteriorated, or the wiring is short-circuited.

  In addition, in the method of forming a non-evaporable getter film in the area adjacent to the side of the panel, undesired gas molecules existing in the area away from the getter, that is, in the central part of the phosphor screen are efficiently adsorbed to the getter. Can not do it. Therefore, the gas pressure at the center of the vacuum envelope increases, and the brightness at the center of the display device decreases. Furthermore, if the substrate is heated with the exhaust pipe or exhaust hole having a small conductance being exhausted, the pressure inside the envelope rises due to the released gas, and the getter is removed until sufficient getter characteristics are obtained. It becomes difficult to activate.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an image display device manufacturing method and an image display device capable of maintaining good display performance over a long period of time and reducing the manufacturing cost. Is to provide.

  An image display device manufacturing method according to an aspect of the present invention includes a front substrate, an envelope disposed opposite to the front substrate and having a rear substrate, and a non-evaporable getter provided in the envelope. A non-evaporable getter powder is formed in the envelope by a non-evaporable getter powder and a metal alkoxide, and the non-evaporable getter powder is heated by heating the metal alkoxide. Is fixed in the envelope.

  An image display device according to another embodiment of the present invention is formed in the envelope by a front substrate, an envelope disposed opposite to the front substrate and having a rear substrate, non-evaporable getter powder and metal alkoxide. A non-evaporable getter member.

  According to the aspect of the present invention, it is possible to effectively function a non-evaporable getter without using an expensive vacuum apparatus, and it is possible to maintain high display performance over a long period of time and to reduce manufacturing costs. It is possible to provide an image display apparatus manufacturing method and an image forming apparatus that can be realized.

Hereinafter, an image display device manufacturing method and an image display device according to embodiments of the present invention will be described in detail with reference to the drawings. Here, as an example of the image display device, an SED including a surface-conduction electron-emitting device will be described.
As shown in FIGS. 1 and 2, the SED includes a front substrate 11 and a rear substrate 12 each made of a rectangular glass plate, and these substrates are arranged to face each other at a predetermined interval. The back substrate 12 is formed with a size larger than that of the front substrate 11. The front substrate 11 and the back substrate 12 constitute a flat envelope 10 whose peripheral portions are joined to each other through a rectangular frame-shaped side wall 13 and the inside is maintained in a vacuum state. The side wall 13 functioning as a bonding member is sealed to the peripheral edge of the front substrate 11 and the peripheral edge of the back substrate 12 by, for example, a sealing material 25 such as low melting glass or low melting metal, and these substrates are bonded to each other. is doing.

  A plurality of plate-like support members 14 are provided inside the envelope 10 in order to support an atmospheric pressure load applied to the front substrate 11 and the rear substrate 12. These support members 14 extend in a direction parallel to one side of the envelope 10 and are arranged at a predetermined interval along a direction orthogonal to the one side. Both ends in the longitudinal direction of each support member 14 are opposed to the side wall 13 with a gap.

  As shown in FIGS. 2 to 4, a phosphor screen 16 that functions as an image display surface is formed on the inner surface of the front substrate 11. The phosphor screen 16 is configured by arranging red, green, and blue phosphor layers R, G, and B, and a black light-shielding layer 20 positioned between the phosphor layers. The phosphor layers R, G, and B of three colors of red, green, and blue are formed alternately with a gap in the first direction parallel to the long side of the front substrate 11, and the phosphor layers of the same color are formed. They are arranged with a gap in a second direction orthogonal to the first direction. Each of the phosphor layers R, G, and B constitutes a subpixel with single colors of red, green, and blue, and constitutes one pixel by combining the subpixels of three colors.

  A matrix-shaped dividing layer 31 is formed so as to overlap the light shielding layer 20 of the phosphor screen 16. A metal back layer 17 made of an aluminum film or the like is formed on the phosphor screen 16. According to this embodiment, the metal back layer 17 is divided in the vertical direction and the horizontal direction by the dividing layer 31 and has a plurality of divided regions that are electrically separated from each other. The metal back layers 17 that are electrically separated from each other by the dividing layer 31 are positioned so as to overlap the phosphor layers R, G, and B, respectively.

  A non-evaporable getter film 23 is formed in a pattern on the light shielding layer 20 of the phosphor screen 16, and here on the dividing layer 31. As will be described later, the getter film 23 is made of a non-evaporable getter and a metal alkoxide, is formed of a non-evaporable getter member, and is disposed on the phosphor screen 16 with a predetermined area. That is, the getter film 23 is formed so as to overlap the dividing layer 31 so as to avoid the phosphor layers R, G, and B, and has a plurality of regions that are electrically separated from each other. The getter film 23 may be provided only in a region that overlaps the light shielding layer 20, but even in a region that overlaps the phosphor layers R, G, and B, a region that does not receive the electron beam from the corresponding electron-emitting device 18 If so, they may be stacked.

  As shown in FIG. 2, on the inner surface of the back substrate 12, a number of surface conduction type electron emitters each emitting an electron beam as an electron source for exciting the phosphor layers R, G, B of the phosphor screen 16 are provided. An element 18 is provided. These electron-emitting devices 18 are arranged in a plurality of columns and a plurality of rows corresponding to each pixel. Each electron-emitting device 18 includes an electron emitting portion (not shown) and a pair of device electrodes for applying a voltage to the electron emitting portion. A large number of wirings 21 for supplying a potential to the electron-emitting devices 18 are provided in a matrix on the inner surface of the rear substrate 12, and end portions thereof are drawn out of the envelope 10.

  Exhaust holes 29 for exhausting the inside of the envelope 10 in the exhaust process are formed through the periphery of the back substrate 12, for example, corners. The exhaust hole 29 is provided at a position away from the phosphor screen 16, that is, at a position away from the effective display area. The exhaust hole 29 is hermetically sealed by the lid member 30. The number of exhaust holes 29 is not limited to one, and can be increased as necessary.

  In such an SED, when displaying an image, an anode voltage is applied to the phosphor screen 16 and the metal back layer 17, and the electron beam emitted from the electron-emitting device 18 is accelerated by the anode voltage to the phosphor screen. Collide. Thereby, the phosphor layers R, G, and B of the phosphor screen 16 are excited to emit light, and a color image is displayed.

Next, the physical properties of the non-evaporable getter member forming the getter film 23 and the SED manufacturing method will be described.
The non-evaporable getter member is formed by mixing the non-evaporable getter and the metal alkoxide as described above. In this embodiment, a mixture containing Zr, V, and Fe is melted by arc melting to produce an ingot, and this ingot is ground to an average particle size of about 10 μm by a pulverizer to obtain non-evaporable getter powder. To manufacture. Prepare Si alkoxide with ethanol as solvent and mix non-evaporable getter powder prepared as above with Si alkoxide (in solution) at a weight ratio of 5: 3 to produce non-evaporable getter member solution did.

  The particle size of the non-evaporable getter powder is desirably 200 μm or less. When the particle size is large, it is difficult to obtain an adhesive force, and further, the adsorption efficiency per unit weight is deteriorated and the efficiency is poor. The metal alkoxide may be any metal material as long as the surface layer is terminated with an alkyl group. For example, Al, Si, Ba, B, Bi, Ca, Fe, Ga, Ge, Hf, Mo, Sn, V, W, and Y can be used as the metal material. The mixing ratio of the metal alkoxide to the non-evaporable getter powder is desirably the minimum amount capable of obtaining sufficient adhesive strength, and it is desirable to select an appropriate mixing ratio depending on the coating method.

  In the manufacturing process, first, the phosphor screen 16 is formed on the plate glass to be the front substrate 11. Subsequently, a matrix-shaped dividing layer 31 is formed on the light shielding layer 20 of the phosphor screen 16, and then a metal back layer 17 made of an aluminum film or the like is deposited on the phosphor screen 16 by vapor deposition. The metal back layer 17 is divided in the vertical direction and the horizontal direction by the dividing line, and forms a plurality of divided regions that are electrically separated from each other.

  Subsequently, the non-evaporable getter member manufactured as described above is sprayed onto the dividing layer 31 through a metal mask to form a patterned getter film 23. The patterned getter film 23 is heated at a temperature of about 100 ° C. and fixed to the front substrate 11. FIG. 5 shows an enlarged view of the getter film 23 formed of the non-evaporable getter particles 23a and the metal alkoxide 23b. The film thickness of the non-evaporable getter film 23 was set to about 30 μm.

  When the metal alkoxide 23b is heated after the getter film 23 is formed, the metal alkoxide 23b becomes a porous network structure, and firmly adheres the non-evaporable getter particles 23a to each other and attaches the surface of the non-evaporable getter particles 23a. It can be exposed in a relatively large area. Therefore, after the non-evaporable getter particles 23a are activated in the subsequent activation step, the gas adsorption function of the non-evaporable getter can be sufficiently exhibited.

  The formation of the getter film 23 is not limited to the spray method, and other methods such as an inkjet method, a dispenser coating method, and a printing method may be used. When applying by the printing method, the flexographic printing method which can form a film easily even with a low-viscosity solution is preferable.

  The film thickness of the getter film 23 is not limited to 30 μm, but is set to about 1 to 500 μm, preferably about 10 to 100 μm. If the film thickness of the getter film 23 is thinner than 1 μm, the gas adsorbing ability after activating the non-evaporable getter will be insufficient as will be described later, and if the film thickness exceeds 500 μm, the getter film 23 tends to peel off. End up. If the thickness of the getter film 23 is 100 μm or less, it hardly peels off, and if it is 10 μm or more, the gas adsorption capability is sufficient. The preferable numerical range of the film thickness is due to the porous structure when the getter film 23 of the present embodiment is heated and fixed to the front substrate.

  Subsequently, as the sealing material 25, a low-melting glass having a softening temperature of about 350 to 500 ° C. is applied in a rectangular frame shape along the outer periphery of the inner surface of the front substrate 11 to form a sealing layer. The low melting point glass is temporarily fired in the atmosphere to remove the organic solvent and the resin.

  On the other hand, the electron-emitting device 18 and the wiring 21 are formed on the plate glass for the back substrate 12. Next, low melting point glass as the sealing material 25 is applied in a rectangular frame shape along the inner periphery of the back substrate 12 to form a sealing layer. The back substrate 12 is temporarily fired in the atmosphere. Thereafter, after aligning the side wall 13 on the sealing layer, the side wall 13 is sealed to the back substrate 12 by raising the temperature to the crystal precipitation temperature of the low melting point glass in the air and maintaining the temperature. Thereafter, the electron-emitting device 18 is activated. Next, the plurality of support members 14 are aligned with respect to the back substrate 12, and the end portions thereof are fixed to the back substrate.

  Subsequently, the peripheral portions of the front substrate 11 and the back substrate 12 formed as described above are sealed. At this time, the best characteristics can be obtained by arranging the front substrate 11 and the rear substrate 12 in the vacuum chamber and sealing the peripheral portions, but it is necessary to prepare a large vacuum chamber and the production cost is reduced. It will be high. Therefore, in the present embodiment, the front substrate 11 and the rear substrate 12 are aligned with each other, and placed in a heating furnace (not shown) in a state of being opposed to each other with a certain gap. And the front substrate 11 and the back substrate 12 are heated to about 500 degreeC. By heating, melting of the low melting point glass previously applied starts. For example, the temperature is maintained at about 500 ° C. in an argon atmosphere over 30 minutes, and the low melting point glass melts and crystal precipitation begins. Thereafter, crystal precipitation of the low melting point glass is almost completed, and the back substrate 12 and the front substrate 11 are sealed to each other through the side wall 13 by the low melting point glass.

  Subsequently, the temperature in the heating furnace is maintained at a high temperature higher than the activation temperature of the getter film, for example, 400 to 450 ° C., and the front substrate 11 and the back substrate 12 are baked for about 1 hour. As a result, undesired gas components adsorbed on the front substrate, the rear substrate, the phosphor screen, and the electron-emitting device are released to perform degassing. In order to prevent oxidation of the electron-emitting device, it is desirable to seal and bake the inside of the heating furnace in an inert atmosphere and a reducing atmosphere. The atmosphere can be selected according to time and temperature.

  During the degassing by baking, the inside of the envelope 10 is exhausted from the exhaust hole 29 by the exhaust pump. As a result, gas components desorbed from the substrate, the phosphor screen, and the like are discharged from the envelope 10 to the outside, and the inside of the envelope 10 is in a clean vacuum state.

When the degree of vacuum inside the envelope 10 is 1 × 10 ⁻³ Pa or less, the front substrate 11 and the back substrate 12 are heated at about 350 to 500 ° C. for a predetermined time, for example, 2 hours, and the non-evaporable getter is Activate. As a result, the activated getter film 23 is in an operating state without substantially deteriorating the adsorption capability.

  After the activation of the non-evaporable getter film 23 is completed, the envelope 10 is cooled to a desired temperature, and the exhaust hole 29 of the envelope 10 is hermetically sealed by the lid member 30. The lid member 30 can be sealed using a known technique such as sealing with a low melting point metal such as indium or welding by local heating. Next, the envelope 10 is removed from the heating furnace. The SED envelope 10 is completed through the above steps.

  According to the SED and the manufacturing method configured as described above, the getter film 23 formed of the non-evaporable getter and the metal alkoxide is formed over the entire surface of the phosphor screen 16 and the phosphor layers R and G. , B is formed on the light shielding layer 20 so as to avoid it. For this reason, the entire interior of the envelope 10 can be maintained at a high degree of vacuum without lowering the luminance by the getter film 23.

  By forming the getter film with a non-evaporable getter member in which a non-evaporable getter and a metal alkoxide are mixed, even when the non-evaporable getter member is heated in the activation process, an organic gas is used as in the case of using an organic binder. Therefore, it is possible to prevent the performance deterioration of the non-deposition type getter. Further, since the metal alkoxide has a porous structure, the exposed area of the non-deposition type getter is large, and a getter film having a high gas adsorption capability can be obtained. At the same time, the generation of organic gas can be prevented even during the operation of the SED. Thereby, an SED capable of maintaining high display performance over a long period of time can be obtained.

  From the above, the non-evaporable getter can be effectively functioned, high display performance can be maintained for a long time, and the manufacturing cost can be reduced without using an expensive vacuum device. It is possible to provide a method for manufacturing an image display device and an image forming apparatus.

  The present invention is not limited to the above-described embodiment, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. Some constituent elements may be deleted from all the constituent elements shown in the embodiments, or constituent elements over different embodiments may be appropriately combined.

  In the above-described embodiment, the SED provided with the front substrate having the phosphor screen on the inner surface has been described as an example of the member to be the getter film. However, the present invention is not limited to this, and the FED and PDP are not limited thereto. The present invention can also be applied to other display devices.

  The dimensions, materials, and the like of each component are not limited to the numerical values and materials exemplified in the above-described embodiment, and can be variously selected as necessary. The getter is not limited to Zr, V, and Fe, and may be a metal such as Ti, Al, Cr, Nb, Ta, W, Mo, Th, Ni, or Mn, or an alloy thereof.

  In the embodiment described above, the non-evaporable getter member is provided on the phosphor screen. However, the present invention is not limited to this, and the getter member may be formed on another constituent member located in the envelope. For example, when the non-evaporable getter member is provided on the structure on the back substrate 12 side, the wiring 21 may be formed at a position where the wiring 21 is not short-circuited at a position away from the electron-emitting device 18.

FIG. 1 is a perspective view showing a partially broken SED according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the SED along line AA in FIG. FIG. 3 is an enlarged plan view showing a part of the front substrate and phosphor screen of the SED. 4 is a cross-sectional view of the front substrate along the line BB in FIG. 3. FIG. 5 is an enlarged sectional view showing a non-evaporable getter film of the SED.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Envelope, 11 ... Front substrate, 12 ... Back substrate, 13 ... Side wall,
14 ... support member, 16 ... phosphor screen, 17 ... metal back layer,
18 ... electron-emitting device, R, G, B ... phosphor layer, 20 ... light shielding layer,
23 ... Non-evaporable getter film, 23a ... Getter powder, 23b ... Metal alkoxide

Claims (17)

In a manufacturing method of an image display device comprising: a front substrate, an envelope disposed opposite to the front substrate and having a rear substrate; and a non-evaporable getter provided in the envelope.
A non-evaporable getter member is formed in the envelope by the non-evaporable getter powder and the metal alkoxide,
A method of manufacturing an image display device, wherein the metal alkoxide is heated to fix the non-evaporable getter powder in the envelope.   The method of manufacturing an image display device according to claim 1, wherein the non-evaporable getter member including the non-evaporable getter powder and the metal alkoxide is applied and formed in the envelope to form a getter film. .   The method for manufacturing an image display device according to claim 2, wherein the getter film is formed by a printing method, an inkjet method, a dispenser coating method, or a spray method.   2. The image display according to claim 1, wherein the metal alkoxide uses Al, Si, Ba, B, Bi, Ca, Fe, Ga, Ge, Hf, Mo, Sn, V, W, Y, or an alloy thereof. Device manufacturing method.   2. The method of manufacturing an image display device according to claim 1, wherein the evaporable getter member is formed to a thickness of 1 to 500 [mu] m.   6. The method of manufacturing an image display device according to claim 5, wherein the evaporable getter member is formed to a thickness of 10 to 100 [mu] m.   The non-evaporable getter uses one or more metals or two or more alloys of Ti, Zr, V, Fe, Al, Cr, Nb, Ta, W, Mo, Ni, and Mn. 7. A method for manufacturing an image display device according to claim 1.   The method for manufacturing an image display device according to claim 1, wherein the non-evaporable getter powder has a particle size of 200 μm or less. After forming the non-evaporable getter member, sealing the peripheral portions of the front substrate and the back substrate,
Heating the envelope at a temperature higher than the activation temperature of the non-evaporable getter to degas the envelope;
While degassing, the inside of the envelope is evacuated,
The method for manufacturing an image display device according to claim 1, wherein the non-evaporable getter is activated after the degassing. An envelope having a front substrate and a rear substrate disposed opposite to the front substrate;
A non-evaporable getter member formed in the envelope by a non-evaporable getter powder and a metal alkoxide;
An image display device comprising:   The image according to claim 10, wherein the metal alkoxide is Al, Si, Ba, B, Bi, Ca, Fe, Ga, Ge, Hf, Mo, Sn, V, W, Y, or an alloy thereof. Display device.   11. The image display device according to claim 10, wherein the evaporable getter member is formed as a getter film having a thickness of 1 to 500 μm.   13. The image display device according to claim 12, wherein the evaporable getter member is formed to a thickness of 10 to 100 μm.   11. The non-evaporable getter is made of one or more metals or two or more alloys of Ti, Zr, V, Fe, Al, Cr, Nb, Ta, W, Mo, Ni, and Mn. 14. The image display device according to any one of items 13.   The image display device according to claim 10, wherein the non-evaporable getter powder has a particle size of 200 μm or less.   The phosphor layer formed on the inner surface of the front substrate, and a plurality of electron sources that are provided on the rear substrate in the envelope and emit electrons that excite the phosphor layer. 10. The image display device according to 10.   The image display device according to claim 16, wherein the non-evaporable getter member is provided in a region where electrons emitted from the electron source do not hit.

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