JP2001181582A - Method for joining conductive members, image display device, and method for manufacturing the same - Google Patents

Abstract

(57) Abstract: A spacer for maintaining a vacuum in an image display device is electrically connected to a front plate and an opposite plate. An image display apparatus comprising: a front substrate provided with an electron-emitting device; and a rear substrate provided with an image forming member for receiving electrons emitted from the electron-emitting device. The conductive spacer and the front substrate or the rear substrate, via an adhesive portion in which the adhesive is impregnated with a conductive powder obtained by removing a solvent or a dispersion medium from a solution or a dispersion containing a conductive powder. Joined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for joining a conductive member to a substrate through an adhesive portion containing a conductive powder, and a method for joining a conductive member to a substrate through an adhesive portion containing a conductive powder. The present invention relates to a method for manufacturing an image display device in which a spacer is bonded to a front substrate or a rear substrate, and an image display device in which the front substrate and the rear substrate are bonded via a conductive spacer.

[0002]

2. Description of the Related Art Heretofore, the applicant of the present invention has disclosed, for example,
Japanese Patent Application Laid-Open No. 241049 discloses a method of applying a conductive adhesive to a joint portion by discharging an adhesive from a nozzle by air pressure from an adhesive tank using a dispenser device when joining members requiring electrical connection. Has been disclosed.
Also, Japanese Patent Application Laid-Open No. 10-279887 discloses a method in which an end surface of a member requiring electrical connection is brought into contact with a thin film of a conductive adhesive to transfer the conductive adhesive to the member.

FIGS. 4 (a) to 4 (d) show the above-mentioned Japanese Patent Application Laid-Open No.
It is explanatory drawing of the transfer method of the electroconductive adhesive material described in 0-279887. First, as shown in FIG. 4A, a conductive adhesive 52 is applied to a coating table 51, and a thin film 54 of the conductive adhesive 52 is formed by an applicator 53.

[0006] Next, as shown in FIG. 4 (b), a member 57 requiring electrical connection is held at a predetermined interval by a jig 55 having a chucking member 56. And FIG.
As shown in (c), a thin film 54 of a conductive adhesive is brought into contact with the end surface of the member 57 requiring electrical connection.

[0005] Next, as shown in FIG.
By pulling up, the thin film 54 of the conductive adhesive is
This is transferred to the end face of the member 57 requiring electrical connection, and the pool 58 of the conductive adhesive thin film 54 is formed. Thus,
A thin film 54 of a conductive adhesive is applied to the member 57, and thereafter, the members are electrically joined through a predetermined process.

Next, an image display device provided with an anti-atmospheric pressure support member called a spacer will be described.

Conventionally, display technologies for flat and thin image display devices include a simple matrix liquid crystal display (LCD), a thin film transistor liquid crystal display (TFT / LCD), a plasma display (PDP), and a low-speed electron beam fluorescent display (VD).
FD) and a multi-electron source flat CRT. As examples of these image display devices, a light emitting element that emits a phosphor using a multi-electron source and a flat and thin image display device using the same will be described.

Here, electron sources are roughly classified into two types, a thermionic source and a cold cathode electron source. Therefore,
There are two types of electron-emitting devices as electron sources: a thermionic electron-emitting device and a cold cathode electron-emitting device. Field emission type (hereinafter, referred to as “FE type”) cold cathode electron sources,
Metal / insulating layer / metal type (hereinafter, referred to as “MIM type”) or surface conduction electron-emitting device (hereinafter, “DCE type”)
Called. ).

An example of the FE type is WPDyke & W.W.Dola
n, “Field emission”, Advance in Electron Physics, 8,
89 (1956) and CASpindt, “Physical properties of thin
-filmfield emission cathodes withmolybdenum cone
s ", J. Appl. Phys., 47, 5248 (1976).

As an example of the MIM type, CAMead “The tu
nnel-emission amplifier ", J. Appl. Phys., 32, 646 (1961)
Etc. are known. An example of a DCE type is MIElinso
n, Radio Eng. Electron Phys., 10 (1965).

The surface conduction electron-emitting device utilizes a phenomenon in which an electron is emitted by passing a current through a small-area thin film formed on a substrate in parallel with the thin film. As this surface conduction type emission element, Sn by Elinson et al.
Using O ₂ thin film, Au thin filmｕG. Dittme
r: “Thin Sold Films”, 9,317 (1972)｝, In ₂ O ₃ / S
By nO ₂ thin film ｛M. Hal twell and CGFonstad:
“IEEE Trans.ED conf.”, 519, (1975)｝, using carbon thin film, ｛Hisashi Araki et al .: “Vacuum”, Vol. 26, No. 1
No. 22, p. 22 (1983)}.

FIG. 5 shows a typical device configuration of the surface conduction electron-emitting device described in the aforementioned M.A. FIG. 3 is a diagram showing a device configuration of a Hartwell. As shown in FIG. 5, a conductive material formed of a metal oxide thin film or the like formed by sputtering in an H-shaped pattern on a substrate 31 and having an electron emission portion 35 formed by an energization process called energization forming described later. A thin film 34 is formed. Since the position and the shape of the electron-emitting portion 35 are unknown, they are schematically shown.

In these surface-conduction electron-emitting devices, the electron-emitting portion 35 is generally formed by applying a current to the conductive thin film 34 before the electron emission by an energization process called energization forming. That is, the energization forming means applying a direct current or a very gradual voltage increase, for example, about 1 V / min, to both ends of the conductive thin film 34 and energizing the conductive thin film 34 to locally destroy, deform or alter the conductive thin film. This is for forming the electron emission portion 35 in an electrically high resistance state.

In the electron emitting section 35, a crack is generated in a part of the conductive thin film 34, and electrons are emitted from the vicinity of the crack. The surface conduction electron-emitting device that has been subjected to the energization forming process applies electrons to the above-described conductive thin film 34 and causes current to flow through the device to cause the above-described electron-emitting portion 35 to emit electrons.

Since the surface conduction electron-emitting device has a simple structure and is easy to manufacture, there is an advantage that a large number of devices can be arranged and formed over a large area. Various applied researches that make use of such characteristics have been conducted.

As an example in which a large number of surface conduction electron-emitting devices are formed in an array, as described later,
JP-A-313332, JP-A-1-283747,
As described in Japanese Patent Application Laid-Open No. 1-257552 and the like, a large number of rows in which surface conduction electron-emitting devices are arranged in parallel, and both ends of each device are connected to wiring (common wiring), respectively. Electron source.

In recent years, in the field of image display devices such as display devices, flat display devices using liquid crystal have become widespread in place of CRTs. However, there is a problem that a backlight must be provided, and the development of a self-luminous display device using an electron-emitting device as described above has been desired.

As a self-luminous display device, for example, as described in US Pat. No. 5,066,883, an electron source in which a large number of surface conduction electron-emitting devices are arranged;
An image display device, which is a display device in which a phosphor that emits visible light with electrons emitted from an electron source is combined.

Since the above-described electron-emitting device is operated in a vacuum, when an electron-emitting device is used to form a display device, it is necessary to adopt an anti-atmospheric pressure structure. In particular, in the case of a display device having a large-area image display surface, the thickness of the members constituting the envelope (vacuum vessel) of the device becomes extremely thick, and this is feasible in terms of the weight and cost of the entire device. Is scarce. As a method of avoiding this problem, a spacer that supports atmospheric pressure is arranged inside the envelope than inside the envelope.

FIG. 6 is an internal configuration diagram of an image display apparatus in which a surface conduction electron-emitting device is used as the above-described electron-emitting device and a spacer is disposed inside the envelope. The image display device shown in FIG. 6 includes a plurality of surface conduction electron-emitting devices 74,
An X-directional wiring 72 connecting both ends of the surface conduction electron-emitting device 74 and a back plate 71 on which a film-like installation such as a Y-directional wiring 73 is formed are provided.

Also, before mounting a plurality of film-like objects such as a phosphor 84 and a metal back 85 on which an image is formed by irradiating an electron beam from the electron-emitting device 74 disposed on the back plate 71 in the facing direction. Face plate 83, front plate 83 and back plate 71
And a support frame 82 that supports the peripheral edges of the front plate 83 and the back plate 71.

The inside of the image forming apparatus is 1.33 ×
There is a case where the electron-emitting device is operated in a vacuum state of about 10 ⁻⁴ Pa (≒ 10 ⁻⁶ Torr) or more. At this time, the front plate 83 and the back plate 71 are located inside the support frame 82.
And the above-mentioned spacer 89 between the arbitrary X-direction wiring 7
2 above to provide an atmospheric pressure resistant structure.

For example, as described in the above-mentioned Japanese Patent Application Laid-Open No. Hei 8-241049, the spacer 89, which is a member requiring electrical connection, has a conductivity such as a semiconductive film formed on soda lime glass. In some cases, a conductive spacer provided may be used, and metal fine powder or metal having conductive performance on frit glass is applied to a film-like installation such as the metal back 85 of the front plate 83 and the X-direction wiring 72 of the rear plate 71. Using a dispenser, the adhesive 80, which is a conductive frit paste to which fine powder or carbon powder or the like coated on the surface is added, is applied from a nozzle of the adhesive tank by air pressure and applied. The spacers are electrically connected and joined.

Further, for example, Japanese Patent Application Laid-Open No. 10-279887 described above
As described in Japanese Patent Application Laid-Open Publication No. H10-209, an adhesive 80 such as a conductive inorganic adhesive obtained by adding a metal powder to an inorganic adhesive is applied by using a transfer coating method, and through a predetermined process, the electric power of the spacer is reduced. In some cases, the connections and connections are made.

[0025]

However, the prior art is based on the problem that the dispersion of the particles having the conductive property in the adhesive in the adhesive tank is not uniform, or the amount of the adhesive itself is reduced. As a result, when the number of particles having conductive properties decreases, good electrical connection cannot be obtained. Therefore, in particular, Japanese Patent Application Laid-Open
According to the technology described in Japanese Patent Application Publication No. 165230, when an image is displayed on an image display device for a long time, the electric field changes due to the charging of the spacer, causing a shift in electron activation, and the light emission position and light emission shape of the phosphor. In some cases.

Further, in order to make the dispersion of the particles having the conductive property uniform, detailed control and a skillful technique are required, so that there is a problem that the workability of the image display device is reduced.

Furthermore, the particles having conductive properties in the conductive adhesive and the components in the adhesive may react with each other in a very small amount. Clogging may occur. this is,
This is a cause of lowering the production yield of the image display device. In particular, according to the technique described in Japanese Patent Application Laid-Open No. 10-279887, it is difficult to form a stable conductive adhesive film on a transfer table. Further, the transferability was changed, and the transfer amount was sometimes unstable.

Accordingly, an object of the present invention is to provide a good electrical connection between a spacer for maintaining a vacuum in an image display device and a front plate and an opposite plate.

[0029]

In order to solve the above-mentioned problems, the present invention provides a method for joining a conductive member to a substrate through a bonding portion containing a conductive powder. In, applying a solution or dispersion containing the conductive powder to the conductive member or the substrate,
Removing a solvent or a dispersion medium from the applied solution or the dispersion; and impregnating the adhesive with the conductive powder from which the solvent or the dispersion medium has been removed; and impregnating the conductive powder. Bonding the conductive member to the base via an adhesive having the adhesive.

The present invention also relates to a method for manufacturing an image display device, comprising the step of joining a conductive spacer to a front substrate or a back substrate via an adhesive portion containing the conductive powder. Applying a solution or dispersion containing the above to the conductive spacer or the front substrate or the rear substrate, removing a solvent or a dispersion medium from the applied solution or the dispersion, and applying the solvent or the dispersion medium. Impregnating the adhesive with the conductive powder from which the conductive powder has been removed, and joining the conductive spacer to the front substrate or the rear substrate via an adhesive portion having the adhesive impregnated in the conductive powder. Performing the steps.

Further, according to the present invention, a front substrate having an electron-emitting device and a rear substrate having an image forming member for receiving electrons emitted from the electron-emitting device are joined via a conductive spacer. In the image display device, the conductive spacer and the front substrate or the rear substrate are impregnated with the adhesive in a conductive powder obtained by removing a solvent or a dispersion medium from a solution or a dispersion containing the conductive powder. It is joined via an adhesive part.

[0032]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIGS. 1 (a) to 1 (d)
FIG. 3 is an explanatory diagram of a method for joining conductive members according to Embodiment 1 of the present invention. First, as shown in FIG. 1A, for example, an ITO (Indium Tin Oxid
e) A thin conductive film 42 such as a film is formed on the entire surface. Then, the conductive powder 43 mixed with methyl alcohol or the like is disposed thereon.

The conductive powder 43 has, for example, an average particle size of 1
Using a stainless steel particle of 00 μm, it is arranged using a dispenser coating device (manufactured by Musashi Engineering Co., Ltd.). The reason why the conductive powder 43 is mixed with methyl alcohol is to take into account the workability in applying the adhesive.

Subsequently, the glass substrate 41 on which the conductive powder 43 has been placed is, for example,
The treatment is carried out at 0 ° C. for 30 minutes, and the methyl alcohol is removed by drying (FIG. 1B). Next, the adhesive 44
(Alon ceramic W manufactured by Toagosei Co., Ltd.) is applied to the conductive powder 43 using the same dispenser coating apparatus to impregnate (FIG. 1C).

Next, a member 45 to be joined, which is a conductive member made of stainless steel or the like, is pressed against the conductive powder 43 impregnated with the adhesive 44 at a pressure of, for example, 1.4 gf / mm ^2. Hold for a few minutes and temporarily fix (Fig. 1
(D)). Thereafter, curing is performed in an electric furnace at, for example, 80 ° C. for 20 minutes, and then, for example, at 150 ° C. for 12 minutes.
Electrical connection and bonding are performed by performing a cure for 0 minutes.

As described above, in the present embodiment, the case where the adhesive 44 is applied on the glass substrate 41 and the member 45 is joined to the glass substrate 41 has been described as an example. It may be applied and the glass substrate 41 may be bonded thereto. Also, the case where a dispersion such as methyl alcohol is included in the conductive powder 43 has been described as an example. This is because the conductive powder 43 is applied by a dispenser device. Body 43
Is applied, a solution such as cellosolve acetate may be included.

(Embodiment 2) FIG. 2 is a perspective view showing the internal configuration of an image display device according to Embodiment 2 of the present invention. FIG.
3A to 3D are manufacturing process diagrams of the image display device shown in FIG. 2, and are cross-sectional perspective views along AA ′ in FIG. 2. In FIGS. 2 and 3 (a) to 3 (d), 91
Is an adhesive. In FIGS. 2 and 3A, the same parts as those shown in FIG. 6 are denoted by the same reference numerals.

First, as shown in FIG. 3A, a fluorescent film 84 on which an image is formed and a metal back 85 are formed on a front plate 83 made of soda lime glass or the like. And
At an arbitrary position on the metal back 85, a spherical silver powder having an average particle size of about 3 μm as the conductive member 91 is referred to as butyl cellosolve acetate (hereinafter referred to as “BCA”) (not shown) in consideration of workability of application. ), Etc., and arranged using a printing method or the like.

Next, as shown in FIG.
The front plate 83 shown in (a) is heat-treated in an electric furnace at, for example, 300 ° C. for 30 minutes, and C. Dry A. Next, as shown in FIG. 3 (c), for example, an adhesive 92 obtained by making Alon Ceramic W manufactured by Toagosei Co., Ltd. fine to an average particle size of about 3 to 5 μm is applied to a dispenser coating device (not shown) (manufactured by Musashi Engineering Co., Ltd.). ) To impregnate the conductive member 91.

Next, as shown in FIG. 3 (d), a conductive spacer 89 having a conductive member formed on the surface thereof by polishing a blue sheet glass is pressed at a pressure of, for example, 2.8 gf / mm ^2. For example, holding for 30 seconds, the adhesive 9
2 is temporarily fixed. Then, in an electric furnace (not shown), curing is performed at, for example, 80 ° C. for 20 minutes, and then, for example, is performed at 150 ° C. for 120 minutes. 89 is electrically connected.

Thereafter, the back plate 71 is provided with an electron source 74 such as a surface conduction electron-emitting device, and an X-direction wiring 72 and a Y-direction wiring 73 for connecting the respective surface conduction electron-emitting devices 74. Next, as shown in FIG. 2, a support frame 82 formed by cutting a blue plate glass substrate into a hollow square shape, for example, is formed between a back plate 71 and a front plate 83 in order to support the periphery thereof. Adhesive 75 (for example,
An airtight envelope structure is obtained by bonding and fixing using LS3081 manufactured by NEC Corporation.

Next, in order to make the inside a vacuum state, an exhaust pipe (not shown) is provided on the front plate 83, the rear plate 71, and the support frame 82, a vacuum is drawn from there, and the exhaust pipe is then sealed.
An image display device is prepared by providing a drive circuit and the like by a method similar to the method disclosed in JP-A-6-342636.

As described above, in the present embodiment, the case where the adhesive 92 is applied on the front plate 83 and the conductive spacer 89 is bonded thereto has been described as an example, but the conductive spacer 89 is bonded to the back plate 71. Alternatively, an adhesive 92 may be applied on the conductive spacer 89, and the front plate 83 or the back plate 71 may be bonded thereto.

In this embodiment, the case where a solution such as cellosolve acetate is included in the conductive powder 91 has been described as an example. This is because the conductive powder 91 is applied by a printing method. Therefore, for example, when the conductive powder 91 is applied by a dispenser device, a dispersion liquid such as methyl alcohol is included.

[0046]

As described above, according to the present invention, a conductive spacer, which is a conductive member, and a front substrate or a rear substrate are formed by removing a solvent or a dispersion medium from a solution or a dispersion containing a conductive powder. Since the bonding is performed via the bonding portion in which the conductive powder is impregnated with the bonding material, the spacer for maintaining the vacuum of the image display device can be electrically connected well to the front plate and the opposite plate.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a bonding method according to a first embodiment of the present invention.

FIG. 2 is a perspective view illustrating an internal configuration of an image display device according to a second embodiment of the present invention.

FIG. 3 is a sectional perspective view taken along line AA ′ of FIG. 2;

FIG. 4 is an explanatory view of a conventional method of transferring a conductive adhesive.

FIG. 5 is a schematic plan view showing a configuration of a conventional surface conduction electron-emitting device.

FIG. 6 is an internal configuration diagram of a conventional image display device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 31 substrate 34 conductive thin film 35 electron-emitting device section 41 glass substrate 42 ITO film 43, 91 conductive powder 44 adhesive 45 bonded member 51 coating base 52 conductive adhesive 53 applicator 54 conductive adhesive thin film 55 cure Component 56 Chucking member 57 Member 58 Reservoir of conductive adhesive 71 Back plate 72 X-direction wiring 73 Y-direction wiring 74 Electron emitting element part 75, 80, 92 Adhesive 82 Support frame 83 Front plate 84 Phosphor 85 Metal back 89 Conductive spacer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J040 HB09 HB31 JA02 JA03 JB10 KA03 KA32 LA09 NA17 NA19 PB01 5C012 AA05 BB01 BB02 5C094 AA43 BA32 BA34 CA19 DA12 DB05 EA02 EB02 EC03 FA01 FA02 FB01 FB04 DA02 GB10 DA03

Claims (7)

[Claims] 1. A method for bonding a conductive member to a substrate via a bonding portion containing the conductive powder, the method comprising: bonding a solution or a dispersion containing the conductive powder to the conductive material. Applying the adhesive to the conductive member or the base; removing the solvent or the dispersion medium from the applied solution or the dispersion; and impregnating the adhesive with the conductive powder from which the solvent or the dispersion medium has been removed. And a step of joining the conductive member to the base via an adhesive portion having the adhesive material impregnated in the conductive powder. 2. The bonding method according to claim 1, wherein the solution or the dispersion contains cellosolve acetate or alcohol. 3. The bonding method according to claim 2, wherein the dispersion containing the alcohol is applied by a dispenser device. 4. The bonding method according to claim 2, wherein the solution containing cellosolve acetate is applied by a printing method. 5. A method for manufacturing an image display device, comprising the step of joining a conductive spacer to a front substrate or a back substrate via an adhesive portion containing a conductive powder, Applying a dispersion liquid to the conductive spacer or the front substrate or the rear substrate, removing a solvent or a dispersion medium from the applied solution or the dispersion liquid, and removing the solvent or the dispersion medium from the conductive liquid. Impregnating the conductive powder with the adhesive, and joining the conductive spacer to the front substrate or the rear substrate via an adhesive having the adhesive impregnated in the conductive powder. A method for manufacturing an image display device, comprising: 6. The method according to claim 5, further comprising the step of providing an electron-emitting device on the front substrate. 7. An image display device comprising a front substrate having an electron-emitting device and a rear substrate having an image-forming member for receiving electrons emitted from the electron-emitting device, which is joined via a conductive spacer. The conductive spacer and the front substrate or the rear substrate are connected via an adhesive portion obtained by impregnating the adhesive with a conductive powder obtained by removing a solvent or a dispersion medium from a solution or a dispersion containing a conductive powder. An image display device characterized by being joined by bonding.