JP2006086033A - Image display device and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display device capable of improving the strength of a substrate and forming a phosphor screen with high accuracy, and having improved reliability and display quality, and a manufacturing method thereof.
An envelope includes a first substrate and a second substrate disposed so as to face the first substrate with a gap. A support substrate 24 is provided in surface contact with the inner surface of the first substrate. The support substrate has a plurality of apertures 26 arranged side by side, and the surface is covered with a blackening film. A phosphor layer is embedded in each opening of the support substrate and faces the first substrate. A plurality of electron emission sources 18 for emitting electrons toward the phosphor layer are provided on the second substrate.
[Selection] Figure 3

Description

  An image display apparatus comprising: a first substrate on which a phosphor screen is formed; and a second substrate on which the plurality of electron sources that are disposed to face the first substrate and excite the phosphor screen are provided. And a manufacturing method thereof.

  2. Description of the Related Art In recent years, various flat-type image display devices have attracted attention as next-generation lightweight and thin display devices that replace cathode ray tubes (hereinafter referred to as CRTs). For example, a surface conduction electron-emitting device (hereinafter referred to as SED) is being developed as a kind of field emission device (hereinafter referred to as FED) which is a flat display device.

  The SED includes a first substrate and a second substrate that are arranged to face each other at a predetermined interval, and these substrates form a vacuum envelope by bonding peripheral portions to each other through rectangular side walls. ing. A phosphor surface having a three-color phosphor layer and a light shielding layer and a metal back are formed on the inner surface of the first substrate, and the inner surface of the second substrate corresponds to each pixel as an electron source for exciting the phosphor. A large number of electron-emitting devices are arranged.

In order to support an atmospheric pressure load acting between the first substrate and the second substrate and maintain a gap between the substrates, a plurality of spacers are disposed between the two substrates. A support substrate is provided between the first substrate and the second substrate, and a plurality of spacers are erected on the support substrate. Further, a plurality of electron beam passage holes through which electron beams emitted from the electron-emitting devices pass are formed in the support substrate (Patent Document 1).

In the SED, when displaying an image, an anode voltage is applied to the phosphor layer, and the phosphor emits light by accelerating the electron beam emitted from the electron-emitting device by the anode voltage and colliding with the phosphor layer. To display the image. In order to obtain practical display characteristics, it is necessary to use a phosphor similar to a normal cathode ray tube and set the anode voltage to several kV or more, preferably 5 kV or more.
JP 2002-082850 A

  In recent years, in the SED, attempts have been made to reduce the thickness of the glass plate constituting the first substrate to about 1 to 2 mm in order to reduce the thickness of the entire apparatus. However, in this case, there is a problem in that the strength of the substrate and the strength of the entire apparatus are reduced as the thickness is reduced.

  Usually, the phosphor screen is formed by forming a matrix-shaped light-shielding layer and a plurality of color phosphor layers on the inner surface of the first substrate by a photolithographic method, and further washing and developing. In this case, it is necessary to form the light shielding layer and the phosphor layer with high accuracy so as not to cause misalignment and overlap. When misalignment, duplication, etc. occur, the color purity of the image deteriorates and the display quality deteriorates. Further, when the phosphor screen is washed and developed, color mixing may occur due to the flow of the phosphor.

  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 capable of improving the strength of a substrate and forming a fluorescent screen with high accuracy, and improving reliability and display quality. And providing a manufacturing method thereof.

  In order to achieve the above object, an image display device according to an aspect of the present invention is arranged side by side with an envelope having a first substrate and a second substrate disposed opposite to the first substrate with a gap. A support substrate provided with a plurality of apertures and having a surface coated with a blackening film and in surface contact with the inner surface of the first substrate; and embedded in each aperture of the support substrate A phosphor layer opposed to the first substrate; and a plurality of electron emission sources provided on the second substrate and emitting electrons toward the phosphor layer.

An image display device manufacturing method according to an aspect of the present invention includes a first substrate, an envelope having a second substrate disposed opposite to the first substrate with a gap, and a plurality of envelopes disposed side by side. And a support substrate provided in surface contact with the inner surface of the first substrate and embedded in each of the openings of the support substrate. In a method for manufacturing an image display device, comprising: a phosphor layer facing a substrate; and a plurality of electron emission sources provided on the second substrate and emitting electrons toward the phosphor layer.
A support substrate having a plurality of openings formed side by side is prepared, the surface of the support substrate is blackened to form a blackened film, the support substrate is bonded to the inner surface of the first substrate, and the first substrate The phosphor layer is formed by embedding the phosphor in the opening of the support substrate bonded to the substrate.

  According to the present invention, the strength of the first substrate can be improved by bonding the support substrate, and the phosphor screen can be formed with high accuracy by using the support substrate as the light-shielding layer. An image display device with improved quality and a method for manufacturing the same can be provided.

Hereinafter, a first embodiment in which the present invention is applied to an SED as a flat-type image display device will be described in detail with reference to the drawings.
As shown in FIGS. 1 to 3, the SED includes a first substrate 10 and a second substrate 12 each made of a rectangular glass plate, and these substrates are arranged to face each other with a gap of about 1 to 2 mm. Yes. The first substrate 10 and the second substrate 12 constitute a flat rectangular vacuum envelope 15 whose peripheral portions are joined to each other via a rectangular side wall 14 made of glass and the inside is maintained in a vacuum. Yes. The side wall 14 is sealed to the peripheral edge portion of the first substrate 10 and the peripheral edge portion of the second substrate 12 by, for example, a sealing material 20 such as low melting point glass or low melting point metal, and joins these substrates together. .

  As shown in FIGS. 2 to 4, the support substrate 24 is bonded to the inner surface of the first substrate 10 in a surface contact state. The support substrate 24 is formed in a rectangular shape slightly smaller than the first substrate 10, and has a first surface 24 a facing the inner surface of the first substrate 10 and a second surface 24 b facing the inner surface of the second substrate 12. Yes. The first surface 24 a of the support substrate 24 is attached to the inner surface of the first substrate 10 with the adhesive layer 28. The adhesive layer 28 is formed of low melting point glass having a thermal expansion coefficient substantially equal to that of the glass constituting the first substrate 10. Thus, the support substrate 24 is positioned so as to overlap almost the entire surface of the first substrate 10.

  The support substrate 24 is formed with a thickness of 0.1 to 0.25 mm, for example, 0.12 mm, using, for example, an iron-nickel metal plate. A plurality of apertures 26 are formed in the support substrate 24 by etching or the like. Each opening 26 is formed in a rectangular shape of, for example, 0.15 to 0.25 mm × 0.15 to 0.25 mm, and the diameter is reduced from the second substrate 12 side toward the first substrate 10 side. It is formed in a tapered shape. When the longitudinal direction of the first substrate 10 is the first direction X and the width direction orthogonal thereto is the second direction Y, the apertures 26 are arranged at a predetermined pitch along the first direction X, and the second direction Y is arranged at a pitch larger than the pitch in the first direction X.

  The surface of the support substrate 24 including the inner wall surface of the opening 26 is blackened and covered with an oxide film 32 having a thickness of 100 μm. A matrix-like light shielding layer is formed on the inner surface of the first substrate 10 by the support substrate 24 thus blackened.

  As shown in FIGS. 3 and 4, phosphors are embedded in the openings 26 of the support substrate 24 to form three-color phosphor layers R, G, and B that are in close contact with the inner surface of the first substrate 10. is doing. The phosphor layers R, G, and B are alternately arranged with a predetermined gap in the first direction X, and the phosphor layers of the same color are arranged with a predetermined gap in the second direction. These phosphor layers R, G, B and the support substrate 24 constitute a phosphor screen.

  On the second surface 24b of the support substrate 24 and the phosphor layers R, G, and B, for example, a metal back layer 17 mainly composed of aluminum is formed, and a getter film 19 is formed on the metal back layer. Is formed. The metal back layer 17 on the second surface 24 b and the metal back layer on each phosphor layer R, G, B are separated by the periphery of each opening 26. Similarly, the getter film 19 on the second surface 24 b and the getter film on each phosphor layer R, G, B are separated by the periphery of each aperture 26.

  As shown in FIGS. 2 and 3, the inner surface of the second substrate 12 has a number of surface conduction types that emit electron beams as electron emission sources for exciting the phosphor layers R, G, and B of the phosphor screen. The electron-emitting device 18 is provided. These electron-emitting devices 18 are arranged in a plurality of columns and a plurality of rows and constitute pixels. The electron-emitting devices 18 are arranged at the same pitch as the openings 26 in the support substrate 24 in the first direction X and the second direction Y, and face the phosphor layers R, G, and B, respectively. 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 driving the electron-emitting devices 18 are provided in a matrix on the inner surface of the second substrate 12, and the end portions thereof are drawn out of the vacuum envelope 15.

  As shown in FIGS. 2 to 4, a large number of spacers 30 are erected integrally on the second surface 24 b of the support substrate 24. The extended end of the spacer 30 is in contact with the inner surface of the second substrate 12, here, the wiring 21 provided on the inner surface of the second substrate 12. The spacers 30 are positioned between the apertures 26 aligned in the second direction Y, respectively. The plurality of spacers 30 are provided side by side with a predetermined pitch in the second direction Y, and are provided side by side with a pitch larger than the predetermined pitch in the first direction X.

  Each of the spacers 30 is formed in a tapered shape having a diameter that decreases from the base end on the support substrate 24 side, that is, the first substrate 10 side, toward the extending end on the second substrate 12 side. . The cross section of each spacer 30 in the direction parallel to the first substrate 10 is substantially elliptical. The spacer 30 is formed of an insulating material mainly composed of glass, and the surface thereof is covered with, for example, a metal oxide such as chromium oxide, copper oxide, or iron oxide, and a metal nitride such as aluminum nitride or titanium nitride. Has been. The spacer 30 configured as described above supports an atmospheric pressure load acting on the first substrate 10 and the second substrate 12, and maintains a predetermined interval between the substrates.

  The SED includes a voltage supply unit (not shown) that applies a voltage to the metal back layer 17. When displaying an image, an anode voltage is applied to the phosphor screen 16 and the metal back layer 17, and an electron beam emitted from the electron-emitting device 18 is accelerated by the anode voltage to collide with the phosphor layers R, G, and B. . As a result, the phosphor is excited to emit light and display an image.

Next, the manufacturing method of SED comprised as mentioned above is demonstrated.
As shown in FIG. 5, first, a support substrate 24 having a predetermined size is prepared. In this case, a metal plate made of Fe-50% Ni with a plate thickness of 0.15 mm is degreased, washed and dried, and then an opening 26 is formed by etching to form the support substrate 24. The entire support substrate 24 is blackened, and the support substrate surface including the inner surface of the opening 26 is covered with an oxide film 32. If blackening of the support substrate 24 is insufficient with the oxide film 32 alone, a black light shielding material may be coated over the oxide film.

  Subsequently, a plurality of spacers 30 are formed on the second surface 24 b of the support substrate 24. In this case, a rectangular mold having substantially the same dimensions as the support substrate 24 is prepared. The mold is formed in a flat plate shape using a transparent material that transmits ultraviolet light, for example, transparent silicon mainly composed of transparent polyethylene terephthalate. The molding die has a flat abutting surface that abuts on the support substrate 24 and a large number of bottomed spacer forming holes for molding the spacer. Each of the spacer forming holes opens on the contact surface of the mold and is arranged at a predetermined interval. Each spacer forming hole is formed in a dimension corresponding to the spacer. Thereafter, the spacer forming hole of the mold is filled with a spacer forming material. As the spacer forming material, a glass paste containing at least an ultraviolet curable binder (organic component) and a glass filler is used. The specific gravity and viscosity of the glass paste are appropriately selected.

  Next, the mold is positioned so that the spacer forming holes filled with the spacer forming material are positioned between the openings 26, and the contact surface is brought into close contact with the second surface 24 b of the support substrate 24. The filled spacer forming material is irradiated with ultraviolet light (UV) from the outer surface side of the support substrate 24 and the mold using, for example, an ultraviolet lamp, and the spacer forming material is UV cured. At that time, the mold is formed of transparent silicon as an ultraviolet transmitting material. Therefore, ultraviolet rays are irradiated directly on the spacer forming material and through the mold. Therefore, the filled spacer forming material can be reliably cured to the inside.

  Thereafter, the mold is peeled from the support substrate 24 so that the cured spacer forming material remains on the support substrate 24. Next, the support substrate 24 provided with the spacer forming material is heat-treated in a heating furnace, the binder is removed from the spacer forming material, and then the spacer forming material is baked at about 500 to 550 ° C. for 30 minutes to 1 hour. Then vitrify. As a result, as shown in FIG. 6, the spacer 30 that is integrally provided on the second surface 24 b of the support substrate 24 is obtained.

  Subsequently, a low-melting glass having the same thermal expansion coefficient as that of the first substrate 10 is spray-applied to the first surface 24 a of the support substrate 24 to form the adhesive layer 28. Next, as shown in FIG. 7, after bonding the support substrate 24 to the glass substrate having a thickness of 1.1 mm constituting the first substrate 10 via the adhesive layer 28, the adhesive layer is heated and baked, The support substrate 24 is fixed to the inner surface of the first substrate.

  Next, as shown in FIG. 8, phosphors are filled in the openings 26 of the support substrate 24 by inkjet, and phosphor layers R, G, and B embedded in the openings are formed. Thereafter, an adhesive is applied to the second surface 24a of the support substrate 24 and the surfaces of the phosphor layers R, G, B for the purpose of improving the adhesion of the metal back layer. As shown in FIG. 9, aluminum is deposited on the second surface 24 a of the support substrate 24 and the phosphor layers R, G, and B in a vacuum atmosphere to form the metal back layer 17. At this time, since each opening 26 of the support substrate 24 is formed in a tapered shape with a reduced diameter on the first substrate 10 side, aluminum does not adhere to the peripheral portion of each phosphor layer. Therefore, the metal back layer 17 on the second surface 24 b and the metal back layer on each of the phosphor layers R, G, and B are formed in a state of being separated by the periphery of each opening 26.

  Subsequently, a getter material is deposited on the second surface 24 a of the support substrate 24 and the phosphor layers R, G, and B in a vacuum atmosphere to form the getter film 19. At this time, since each opening 26 of the support substrate 24 is formed in a tapered shape with a reduced diameter on the first substrate 10 side, the getter material does not adhere to the peripheral portion of each phosphor layer. Therefore, the getter film 19 on the second surface 24 b and the getter film on each phosphor layer R, G, B are formed in a state of being separated by the periphery of each opening 26. Further, a metal oxide, for example, chromium oxide is deposited on the spacer 30 by vapor deposition to form a film.

  On the other hand, in manufacturing the SED, the second substrate 12 having the electron-emitting devices 18 and the wirings 21 and the side walls 14 bonded thereto is prepared in advance. Subsequently, the first substrate 10 to which the support substrate 24 is fixed and the second substrate 12 are arranged in a vacuum chamber, the inside of the vacuum chamber is evacuated, and then the first substrate is attached to the second substrate through the side wall 14. To join. Thus, an SED in which the spacer 30 and the support substrate 24 are sandwiched between the first substrate and the second substrate is obtained.

  According to the SED configured as described above, even when the first substrate is formed of a thin glass plate, the strength of the first substrate can be improved by bonding the support substrate 24 together. Thereby, the mechanical strength of the whole vacuum envelope can be improved. Further, by forming the phosphor layer in the opening 26 formed in the support substrate 24, the phosphor layer can be easily formed, and the positions of the support substrate and the phosphor layer constituting the light shielding layer The deviation can be reduced and a highly accurate phosphor screen can be obtained. Further, when the phosphor layer is washed and developed, the phosphor can be prevented from flowing out and the occurrence of color mixing can be suppressed. From the above, the display quality can be improved.

  By forming the phosphor layer in the opening 26 of the support substrate 24, when forming the metal back layer and the getter film, the metal back layer and the getter layer can be easily divided by the peripheral edge of the opening. Can do. As a result, the generation of discharge can be suppressed, the scale of discharge can be reduced, and a highly reliable SED with improved pressure resistance can be obtained.

Next explained is a method for manufacturing an SED according to the second embodiment of the invention. The configuration of the SED itself is the same as that in the first embodiment described above.
As shown in FIG. 10, a support substrate 24 having openings 26 is prepared, and the entire surface is blackened. Subsequently, a plurality of spacers 30 are formed on the second surface 24b of the support substrate 24 by the same method as in the above embodiment. Thereafter, a frit glass having the same thermal expansion coefficient as that of the first substrate is applied to the first surface 24 a of the support substrate 24 to form a glass film 28 in which the apertures 26 are closed.

  In this state, as shown in FIG. 11, each aperture 60 of the support substrate 24 is filled with a phosphor by, for example, ink jet, and phosphor layers R, G, and B are formed in the aperture. At this time, a glass film is used as a base, and a phosphor is filled thereon. As shown in FIG. 12, after the support substrate 24 on which the phosphor layers R, G, and B and the glass film 28 are formed is bonded to the inner surface of the first substrate 10 through the glass film 28, the glass film 28 is attached. The support substrate 24 is fixed to the inner surface of the first substrate by heating and baking.

  Next, an adhesive is applied to the second surface 24 a of the support substrate 24 and the surfaces of the phosphor layers R, G, and B. As shown in FIG. 13, aluminum is deposited on the second surface 24 a of the support substrate 24 and the phosphor layers R, G, and B in a vacuum atmosphere to form the metal back layer 17. Further, a getter material is deposited on the second surface 24 a of the support substrate 24 and the phosphor layers R, G, and B in a vacuum atmosphere to form the getter film 19. At this time, since the phosphor layers R, G, and B are formed in the openings 26 of the support substrate 24, the metal back layer 17 and the getter film 19 can be divided by the peripheral edges of the openings 26.

Thereafter, a metal oxide, for example, chromium oxide is deposited on the spacer 30 by vapor deposition to form a coating. Subsequently, the SED in which the first substrate is bonded to the second substrate via the side wall 14 and the spacer 30 and the support substrate 24 are sandwiched between the first substrate and the second substrate by the same process as the above-described embodiment. Get.
Also by the above manufacturing method, the same SED as in the first embodiment described above can be manufactured.

  In the first and second embodiments described above, the columnar spacer 30 is used as the spacer. However, the present invention is not limited to this, and a plate-like spacer may be used. Further, the spacer may be erected not only on the support substrate but also on the second substrate. Furthermore, a configuration in which the spacer is omitted is also possible. When the spacer is not used, the phosphor may be dropped into the opening 26 of the support substrate 24 and printed by screen printing to form the phosphor layer in the opening.

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

  The diameter and height of the spacer, the dimensions and materials of the other components are not limited to the above-described embodiment, and can be appropriately selected as necessary. The present invention is not limited to one using a surface conduction electron-emitting device as an electron source, but can also be applied to an image display apparatus using another electron source such as a field emission type or a carbon nanotube.

The perspective view which shows SED which concerns on 1st Embodiment of this invention. The perspective view of said SED fractured | ruptured along line AA of FIG. Sectional drawing which expands and shows the said SED. The top view which shows the 1st board | substrate in the said SED, a support substrate, and a spacer. Sectional drawing which shows the support substrate in the manufacturing process of the said SED. Sectional drawing which shows the state which formed the spacer on the said support substrate. Sectional drawing which shows the state which bonded the said support substrate to the 1st board | substrate. Sectional drawing which shows the process of filling a fluorescent substance in the opening of the said support substrate. Sectional drawing which shows the process of forming a metal back layer on the said support substrate. Sectional drawing which shows the process of forming a glass film and a spacer on a support substrate in the manufacturing method of SED which concerns on the 2nd Embodiment of this invention. Sectional drawing which shows the process of forming a fluorescent substance layer in the opening of the said support substrate. Sectional drawing which shows the state which bonded the said support substrate to the 1st board | substrate. Sectional drawing which shows the process of forming a metal back layer on the said support substrate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... 1st board | substrate, 12 ... 2nd board | substrate, 14 ... Side wall, 15 ... Vacuum envelope,
16 ... phosphor screen, 18 ... electron-emitting device, 24 ... support substrate,
26 ... Open hole, 30 ... Spacer

Claims (10)

An envelope having a first substrate and a second substrate disposed opposite to the first substrate with a gap;
A support substrate having a plurality of apertures arranged side by side and having a surface coated with a blackening film and in surface contact with the inner surface of the first substrate;
A phosphor layer embedded in each opening of the support substrate and facing the first substrate;
An image display apparatus comprising: a plurality of electron emission sources provided on the second substrate and emitting electrons toward the phosphor layer.   Each opening of the support substrate is formed in a tapered shape having a diameter reduced from the second substrate side toward the first substrate side, and is overlapped with the second substrate side surface of the support substrate and the phosphor layer. The image display device according to claim 1, wherein a back layer is formed, and the metal back layer is electrically divided at a peripheral edge of each opening.   3. The image display device according to claim 1, further comprising a plurality of spacers that stand on the support substrate and abut against the second substrate. 4.   4. The image display device according to claim 1, wherein the support substrate is attached to an inner surface of the first substrate with an adhesive having a thermal expansion coefficient approximate to that of the first substrate. 5. An envelope having a first substrate and a second substrate disposed opposite to the first substrate with a gap, a plurality of apertures arranged side by side, and a blackened surface A support substrate that is covered with the inner surface of the first substrate and provided in surface contact with the inner surface of the first substrate; a phosphor layer that is embedded in each opening of the support substrate and faces the first substrate; and the second substrate A plurality of electron emission sources that emit electrons toward the phosphor layer, and a manufacturing method of an image display device,
Prepare a support substrate formed with a plurality of apertures aligned,
Blackening the surface of the support substrate to form a blackened film;
The support substrate is bonded to the inner surface of the first substrate,
A method of manufacturing an image display device, wherein a phosphor layer is formed by embedding a phosphor in an opening of a support substrate bonded to the first substrate.   After applying a low melting point glass having a thermal expansion coefficient approximate to that of the first substrate to one surface of the support substrate, the support substrate is bonded to the inner surface of the first substrate through the low melting point glass, The method for manufacturing an image display device according to claim 5, wherein the melting point glass is heated and baked to fix the support substrate to the first substrate.   7. The image display device according to claim 5, wherein a phosphor is printed in an opening of a support substrate attached to the first substrate, and a phosphor layer is formed in the opening. 8. Method.   The metal back layer is formed on the surface of the support substrate from the support substrate side by vapor deposition in a vacuum atmosphere after forming the phosphor layer. Manufacturing method of image display apparatus.   After a plurality of spacers are erected on the support substrate, the support substrate is bonded to the inner surface of the first substrate, and each hole in the support substrate is filled with a phosphor to form the phosphor layer. The method for manufacturing an image display device according to claim 5, wherein the image display device is manufactured. A plurality of spacers are erected on one surface of the support substrate,
On the other surface of the support substrate is formed a glass film closing the openings.
After forming the glass film, a phosphor layer is formed in each opening,
The support substrate on which the phosphor layer is formed is bonded to the inner surface of the first substrate through the glass film, and the glass film is heated and baked to fix the support substrate to the first substrate. A method for manufacturing an image display device according to claim 5.

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