JPH09199065A - Image forming apparatus and manufacturing method thereof - Google Patents

Abstract

There is provided a method of manufacturing an image forming apparatus with small thermal strain and deformation by lowering the temperature at the time of sealing an electron source substrate and a face plate in the image forming apparatus. The electron source substrate and the support frame are sealed by anodic bonding between a conductive thin film formed on the electron source substrate and the support frame.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and its manufacturing method.

[0002]

2. Description of the Related Art Conventional image forming apparatuses include TFT type and M type.
Although there is an IM type liquid crystal type image forming apparatus, when it is applied to a large screen panel having a diagonal size of 40 inches or 60 inches, it is necessary to form an active element for each pixel in the TFT type, so that a high-definition patterning is performed over a large screen. Is required. Also MIM
Since the mold has a slow response speed, it is not suitable for an image forming apparatus that handles moving images. As described above, there is a technical difficulty in increasing the screen size of the liquid crystal image forming apparatus. Therefore, as a large-screen flat-type image forming apparatus, a phosphor-emitting image forming apparatus that emits a phosphor by electron beam irradiation to form an image is expected. In the phosphor-emission-type image forming apparatus, drawing is performed with a combination of a surface conduction electron-emitting device, an electron-emitting device such as a thermoelectron source, and a phosphor.

As an example of the surface conduction electron-emitting device, one described in the report of Erinson (MIElinson, Radio En
g. Electron Phys., 10 (1965)). The surface conduction electron-emitting device utilizes the fact that electron emission occurs when a current is passed through a thin film of a small area formed on a substrate in parallel with the film surface. As the surface conduction electron-emitting device, one using a SnO ₂ thin film by Erinson et al., One using an Au thin film (G. Dittmer, "Thin Solid Fil
ms ", 9, 317 (1972)) etc. have been reported.

Since the surface conduction electron-emitting device described above has a simple structure and is easy to manufacture, it has an advantage that a large number of devices can be arranged over a large area.

However, even in the image forming apparatus using such surface conduction electron-emitting devices, various problems occur as the area of the image forming apparatus increases. Above all, the step of sealing the electron source substrate and the face plate on which the phosphor is arranged on the inner wall surface through the support frame is important.

In FIG. 4, 101 is an electron source substrate in which an electron-emitting device is formed on the substrate, and 109 is a metal back 107.
And a face plate having the phosphor 108 formed on the inner wall,
Reference numeral 105 is a support frame, and 102 is a take-out wiring. Electron source substrate 101, support frame 105, and face plate 10
9 is usually coated with frit glass 106 and 40 in the atmosphere.
It is sealed by firing at 0 ° C to 500 ° C.

Particularly in the case of a color face plate, it is necessary to associate each color phosphor with an electron-emitting device, and it is necessary to perform sufficient alignment.

[0008]

However, since the sealing process using the frit glass is a high temperature process of 400 ° C. to 500 ° C., thermal strain, deformation, deterioration of wiring, etc. occur, and particularly with the thermal strain and deformation. Limitation of dimensional accuracy at the time of sealing has become a big problem toward high definition.

The present invention has been made in view of the above problems, and an object of the present invention is to reduce thermal distortion and deformation by lowering the temperature at the time of sealing the electron source substrate and the face plate in the image forming apparatus. To provide a method for manufacturing an image forming apparatus having a small size.

[0010]

The present invention provides an electron source substrate having a plurality of surface conduction electron-emitting devices arranged on an insulating substrate.
In an image forming apparatus including a face plate having a phosphor provided on the inner wall surface; and an electron source substrate and a support frame supporting the face plate, the electron source substrate and the support frame are sealed on the electron source substrate. There is provided an image forming apparatus characterized in that the formed conductor thin film and a supporting frame are joined by anodic bonding.

In the above, the conductor thin film is Al,
One or more elements selected from Ti, Ni and Si,
It is preferable to contain one or more elements selected from Au, Pt and Cu.

Furthermore, the present invention provides Au, P on the electron source substrate.
forming a first conductor thin film containing one or more elements selected from t and Cu; Al, Ti, and
Second containing at least one element selected from Ni and Si
Forming a conductor thin film of the above; heating the electron source substrate to form an alloy thin film of the first thin film and the second thin film; and anodic bonding the alloy thin film and the support frame. Provided is a method for manufacturing an image forming apparatus having the above.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

The anodic bonding method uses glass and a conductive material or a conductive thin film, so that glass and a glass, a semiconductor,
This is a method in which various materials such as metals can be joined by applying a voltage of several tens to several kV at a relatively low temperature of 200 ° C to 400 ° C.

By using the anodic bonding method, not only sealing at low temperature is possible, but also it is not easily affected by the atmosphere (conventional sealing by frit glass cannot be performed unless oxygen is sufficiently supplied). Not only does it have the advantage of improving accuracy, but it also simplifies the manufacturing method.

The conductive thin film is not formed on the supporting frame but is formed on the electron source substrate because the wiring for applying a voltage to the conductive thin film can be easily formed at the time of anodic bonding.

In the anodic bonding, Al is used as a conductive thin film,
A material that forms an oxide such as Ti relatively easily is used. However, in a metal thin film such as Al that is easily oxidized, an oxide is formed in the Al thin film as the bonding time elapses, and a portion that causes poor bonding is likely to occur.

For this reason, it causes a decrease in the bonding strength. This becomes a particular problem when the joint area becomes large.

The present invention relates to Al, which can be easily joined to glass,
By alloying Ti, etc. with Au, Pt, and Cu, oxidation at the time of joining the conductor thin films is suppressed, and stable joining is realized, so that the joining strength does not decrease even when the joining area is large. It enables sealing by anodic bonding.

The temperature for alloying the two conductor thin films depends on the combination of metals, but is about 100 ° C. for Au and Al, 200 ° C. or higher for Au and Ti, and about 350 ° C. for Pt and Al. For the temperature for alloying the two-layer thin film, see the description by Poat et al.
et al, "THIN FILM-INTERDIFFUSION AND REACTION", Joh
n Wiley & Sons, Inc., 1978).

The method for forming the conductor thin film includes vacuum vapor deposition, sputtering, CVD and the like. When the adhesion between the conductor thin film and the substrate is weak, it is necessary to provide an adhesion layer such as Cr.

FIG. 3 is a plan view of the electron source substrate 101.
301 is a lower wiring, 302 is an upper wiring, 303 is an insulating layer, 3
Reference numeral 04 is a device electrode, and 305 is a conductive thin film including an electron emitting portion.

Element electrode 304, upper wiring 303, lower wiring 3
For 01, a general wiring material is used. The conductive thin film 305 including the electron emitting portion is preferably a fine particle film composed of fine particles, and the material thereof is Pd, Pt, Ru, Ag, Au, T.
i, In, Cu, Cr, FeZn, Sn, Ta, W, P
Metals such as b, PdO, SnO ₂ , In ₂ O ₃ , PbO, S
oxides such as b ₂ O ₃ ; HfB ₂ , ZrB ₂ , LaB ₆ , Ce
Borides such as B ₆ , YB ₄ , GdB ₄ ; TiC, ZrC,
Carbides such as HfC, TaC, SiC; TiN, ZrN,
Examples include nitrides such as HfN; semiconductors such as Si and Ge; carbon and the like.

Further, as a method of forming the electron emission substrate, it can be formed by using a normal semiconductor process.

FIG. 1 is a diagram showing the structure of an image forming apparatus according to the present invention, FIG. 1 (a) is a sectional view of the periphery of a supporting frame of the apparatus, and FIG. 1 (b) is FIG. 1 (a). ) Is a side view seen from the direction of the arrow.

Reference numeral 101 is an electron source substrate, 102 is extraction wiring, 103 is an insulating layer, 104 is a conductive thin film, 105 is a support frame, 106 is frit glass, 107 is a metal back, 108 is a phosphor, and 109 is a face plate. Show.

FIG. 2 is a process chart showing the procedure of one embodiment of the manufacturing method of the present invention. It will be explained step by step.

After the electron source substrate is manufactured (FIG. 2A), the insulating layer 103 is formed on the sealing portion. Specifically, a SiO ₂ film is formed by sputtering or the like, and patterning and etching are performed to form the insulating layer 103 in the sealing portion (FIG. 2B). Next, the insulating layer of the sealing portion is further etched to flatten the unevenness due to the wiring (FIG. 2C). A conductor thin film 104 is formed thereon (FIG. 2D).

Thereafter, the conductive thin film is alloyed by heating once, and then anodic bonding can be performed by applying a voltage to the support frame and the conductive thin film.

As described above, in the image forming apparatus of the present invention, the electron source substrate and the support frame are sealed at a low temperature by anodic bonding, so that the error of the positional accuracy due to the thermal strain or the deformation during the sealing can be suppressed.

Further, since the bonding can be stably realized even if the bonding area becomes large, it is advantageous for increasing the area. Furthermore, unlike the conventional frit glass, it is not affected by the atmosphere,
There is also an advantage that manufacturing is simple.

[0032]

EXAMPLE After the electron source substrate having the structure shown in FIG. 3 was formed, the electron source substrate and the face plate were joined by the following procedure. The electron source substrate is manufactured using soda lime glass as a substrate. The supporting frame was made of soda-lime glass, the adhesion layer was made of Cr, the first conductor thin film was made of Au, and the second conductor thin film was made of Al.

After the insulating layer 103 is flattened as shown in FIG. 2, resist patterning is performed so that a conductor thin film is formed only on the sealing portion, and conductor thin films Cr, Au, and Al are sequentially electron beam evaporated. The film was formed by. The adhesive layer is for enhancing the adhesive force between Au and SiO _{2 of the} insulating layer. The film thickness of Au was 85 nm, and the film thickness of Al was 15 nm. The bonding conditions are a bonding temperature of 350 ° C. and an applied voltage of 300 at the time of bonding.
V, bonding time is 30 minutes.

The heat treatment for alloying was performed by heating during anodic bonding.

The image forming apparatus formed as described above could be evacuated to a high vacuum after joining.

Anodic bonding was performed under the same bonding conditions for the combinations shown in Table 1 below as conductor thin films.
Both could be joined stably.

[0037]

[Table 1]

[0038]

As described above, by sealing the electron source substrate and the support frame by anodic bonding, it becomes possible to carry out the sealing at a lower temperature than the conventional sealing with frit glass. Thereby, the electron source substrate and the face plate can be accurately aligned. Further, even if the joining area is large, the joining can be performed stably, and since it is not affected by the atmosphere and the like, the manufacturing apparatus becomes simple, which is industrially advantageous.

[Brief description of drawings]

1A and 1B are views showing the structure of an embodiment of an image forming apparatus of the present invention, FIG. 1A is a sectional view thereof, and FIG. 1B is a side view of FIG.

FIG. 2 is a process drawing showing a procedure of one embodiment of a method for manufacturing an image forming apparatus of the present invention.

FIG. 3 is a schematic plan view of an electron source substrate of an example of the image forming apparatus of the present invention.

FIG. 4 is a sectional view of a conventional image forming apparatus.

[Explanation of symbols]

 101 electron source substrate 102 extraction wiring 103 insulating layer 104 conductor thin film 105 support 106 frit glass 107 metal back 108 fluorescent substance 109 face plate 301 lower wiring 302 upper wiring 303 insulating layer 304 device electrode 305 conductive thin film

Claims (3)

[Claims] 1. An electron source substrate having a plurality of surface conduction electron-emitting devices arranged on an insulating substrate; a face plate provided with a phosphor on an inner wall surface; and a support frame for supporting the electron source substrate and the face plate. In the image forming apparatus consisting of
An image forming apparatus, wherein the electron source substrate and the support frame are sealed by anodic bonding between a conductive thin film formed on the electron source substrate and the support frame. 2. The image forming method according to claim 1, wherein the conductive thin film contains one or more elements selected from Al, Ti, Ni and Si and one or more elements selected from Au, Pt and Cu. apparatus. 3. A step of forming a first conductor thin film containing one or more elements selected from Au, Pt and Cu on an electron source substrate; Al, Ti, Ni and Si on the thin film.
Forming a second conductor thin film containing one or more elements selected from the following: heating an electron source substrate to form an alloy thin film of the first thin film and the second thin film; A method of manufacturing an image forming apparatus, comprising a step of anodic bonding the alloy thin film and a support frame.