JPH11213923A - Flat surface display device and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict the generation of crack in a junction part of a sealing member and boards by arranging a second board having a coefficient of thermal expansion different from a first board opposite to the first board with a space, and sealing the first and the second boards with a sealing member having a coefficient of thermal expansion close to that of the first and the second boards. SOLUTION: A sealing member 3 formed by integrally laminating a first sealing member 31 formed of a glass having a coefficient of thermal expansion close to that of a first board 1 and to be joined with the first board 1 and a second sealing member 32 formed of a glass having a coefficient of thermal expansion close to that of a second board 2 and to be joined with the second board 2 for fixation is used. As the second sealing member 32, a glass having a coefficient of thermal expansion at an intermediate value between the first sealing member 31 and the second board 2 is selected. With this structure, a difference of the coefficient of thermal expansion between the first board 1 and the sealing member 3 and between the second board 2 and the sealing member 3 is restricted small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat display device using an electron-emitting device such as a field emission cathode and a method of manufacturing the same.

[0002]

2. Description of the Related Art Recently, field emission displays (hereinafter referred to as FEDs) using a field emission type microcathode.
Called. ) -Type flat panel display devices are being developed. The FED type flat display device is an extremely thin display device that performs display by emitting electrons from a conical field emission type microcathode to excite a phosphor.

This FED type flat display device includes a first substrate having a field emission type microcathode (hereinafter, referred to as a field emission type cathode) as an electron emission element and a second substrate having a phosphor. They are arranged to face each other, and the two substrates are sealed with a sealing member. That is, a plurality of cathode electrodes are formed on the surface of the first substrate made of glass in a striped manner, and an insulating layer is formed over the entire surface of the first substrate on the surfaces of the plurality of cathode electrodes. A plurality of gate electrodes are formed on the surface of the insulating layer in a stripe shape in a direction perpendicular to the cathode electrodes. At each intersection where the plurality of cathode electrodes and the plurality of gate electrodes intersect, a plurality of holes penetrating the respective electrodes and the insulating layer are formed in a dispersed manner, and each of the holes formed at each of the intersections is formed. A field emission cathode having a conical shape in the cathode is formed therein.

A plurality of transparent electrodes are formed on the surface of a second substrate made of glass in a stripe pattern, and R (red) and G are formed on the surfaces of the plurality of transparent electrodes, respectively.
(Green) and B (blue) phosphors are formed. The first substrate and the second substrate are opposed to each other at a predetermined interval with their respective electrode forming surfaces facing each other. Here, the stripe-shaped transparent electrode and the phosphor face, for example, a gate electrode. The first substrate and the second substrate are hermetically sealed by a sealing member made of glass interposed between the respective peripheral portions, and
A display device whose inside is vacuum is constituted by the substrate, the second substrate, and the sealing member.

[0005] The flat-panel display device configured as described above has the following features.
When a voltage is applied between the gate electrode on the first substrate and the field emission cathode, a current is emitted from the tip of the field emission cathode due to a field emission effect. At this time, a voltage is applied to the transparent electrode facing the field emission cathode. When is applied, the phosphor is irradiated with the electrons to excite the phosphor and emit light, thereby performing display.

[0006] The flat-panel display device configured as above is
It is manufactured by the method described below. On the surface of the first substrate,
A cathode electrode is formed by patterning by a method such as sputtering or vacuum evaporation, an insulating layer is formed on the cathode electrode, and then a gate electrode is formed on the insulating layer by patterning. Then, a plurality of holes penetrating each electrode and the insulating layer are formed at the intersection of the cathode electrode and the gate electrode by a method such as wet edging, and further formed on the gate electrode inside the holes by a method such as evaporation or sputtering. A conical field emission cathode is formed. Also, a transparent electrode is patterned and formed on the surface of the second substrate by a method such as sputtering or vacuum evaporation.
Next, RGB phosphors are patterned on the transparent electrode.

[0007] A sealing member such as a dispenser or screen printing is provided on one or both of the periphery of the electrode formation surface of the first substrate and the periphery of the electrode formation surface of the second substrate. Apply sealing glass paste. Next, after the substrate on which the sealing member is applied is pre-baked to decompose and burn the binder contained in the sealing member, the first substrate and the second substrate are placed with their respective electrode forming surfaces facing each other. It is placed and fired by sticking it through a sealing member. As a result, the sealing member seals the first substrate and the second substrate to produce a closed container. After that, the first substrate and the second substrate are sealed under a high vacuum of 10 ^-8 Torr or more.

In this flat panel display device, the sealing member for adhering the first substrate and the second substrate has a coefficient of thermal expansion that is equal to the coefficient of thermal expansion of the material forming the first and second substrates. It must be formed of similar materials. The approximation of the coefficient of thermal expansion of the sealing member to the coefficient of thermal expansion of the first substrate and the second substrate can be performed at a level of 10 ⁻⁷ to 10 ⁻⁷ as in the case of the flat display device.
It is important to prevent cracks from occurring at the joint (bonding film) between the sealing member and the substrate in an airtight container that needs to maintain a high vacuum of ^-10 .

By the way, in the manufacture of the conventional flat display device, the sealing member is formed of glass in consideration of approximating the thermal expansion coefficients of the first substrate and the second substrate.
However, as described above, the coefficient of thermal expansion of the first
Is different from the thermal expansion coefficients of the substrates, there is a limit to the sealing member having a thermal expansion coefficient that matches the thermal expansion coefficients of both substrates. Cracks may occur at the joint (bonding film) between the substrate and the joint (bonding film) between the sealing member and the second substrate.

In order to maintain normal electron emission characteristics, the field emission cathodes located inside the first substrate and the second substrate, the electrodes, and the materials forming the phosphors prevent heat change. There is a need. In particular, field emission cathodes
The tip has an extremely fine shape with a radius of curvature of several millimeters, is very active against heat, and when formed of a metal such as molybdenum that oxidizes at a temperature of 400 ° C., an oxide is generated on the surface. You.

However, in the production of the conventional flat display device, a step of temporarily baking the sealing member applied to the substrate, a step of sealing the first substrate and the second substrate with the sealing member, and a closed container Are heated at a high temperature of about 400.degree. C. or 400.degree. C. or more, respectively, in a step of evacuating the inside. For this reason, the field emission cathode is oxidized in these steps, and the surface is contaminated with the oxide, so that normal electron emission characteristics may not be obtained.

[0012]

Therefore, in order to avoid a heating step at a temperature of 400 to 450 ° C. in which thermal oxidation of the field emission cathode occurs, a low melting point glass which can be fired at a temperature lower than 400 ° C. is sealed. It can be used for members. However, in this case, the coefficient of thermal expansion of the sealing member (adhering glass) is 1.5 to 2 times larger than the coefficient of thermal expansion of the glass forming the first and second substrates,
Since the thermal expansion coefficients of the deposition glass and the first and second substrates do not match, cracks occur at the joint (bonding film) between the sealing member and the substrate, and the high vacuum of the display device cannot be maintained.

A method of sealing the first and second substrates by placing the entire display device in a reducing atmosphere has been disclosed (Japanese Patent Application Laid-Open Nos. Hei 4-322038 and Hei 7).
-122209). According to this method, oxidation of the surface of the field emission cathode can be avoided even if the sealing member is heated at a temperature of 400 ° C. or more because of the reducing atmosphere. Insufficient oxygen is required to decompose and burn the binder contained in the glass for use sufficiently, and the binder does not burn sufficiently. For this reason, impurities and gas remain in the sealing member (adhering glass), and this state causes a crack at a bonding portion (bonding film) between the sealing member and the substrate.

As described above, the conventional flat display device has a problem that the sealing between the first substrate and the second substrate lowers the reliability of the device. An object of the present invention is to provide a flat-panel display device capable of sealing a first substrate and a second substrate satisfactorily while maintaining high reliability of the device.

An object of the present invention is to provide a manufacturing method capable of obtaining a flat display device capable of sealing the first substrate and the second substrate satisfactorily while maintaining high reliability of the device. I do.

[0016]

According to a first aspect of the present invention, there is provided a flat panel display device comprising: a first substrate having an electron-emitting device; and a phosphor having a phosphor, which is disposed so as to face and separate from the first substrate. A second substrate having a thermal expansion coefficient different from that of the first substrate, and a sealing member disposed between the first substrate and the second substrate and sealing both of the substrates. In the sealing member, a portion close to the first substrate has a coefficient of thermal expansion close to a coefficient of thermal expansion of the first substrate, and a portion close to the second substrate is It has a thermal expansion coefficient close to the thermal expansion coefficient of the second substrate.

According to the structure of the present invention, the first substrate and the second substrate are partially different in the coefficient of thermal expansion so as to correspond to the respective coefficients of thermal expansion of the first substrate and the second substrate. The difference in thermal expansion coefficient between the sealing member and the second substrate and the sealing member is small, and cracks are generated at the joint between the sealing member and the substrate due to the difference in thermal expansion coefficient. It is possible to suppress occurrence of cracks in the sealing member when sealing the first and second substrates.

According to a second aspect of the present invention, the thermal expansion coefficient of the first substrate is smaller than the thermal expansion coefficient of the second substrate. According to the present invention, when the thermal expansion coefficient of the first substrate having the electron-emitting device that is susceptible to oxidation in air is set to be small, the sealing member and the first substrate and the sealing member and the second substrate Between them can be prevented.

According to a third aspect of the present invention, in the flat display device according to the first aspect, the sealing member has a softening point that decreases from the second substrate toward the first substrate. And

According to the present invention, cracks in the sealing member can be prevented from occurring when the first and second substrates are sealed, and the first substrate having the electron-emitting device and the sealing member can be prevented. Can be performed at a low temperature, and the degree of oxidation of the electron-emitting device can be minimized.

According to a fourth aspect of the present invention, in the flat display device according to the first aspect, the sealing member is entirely formed on a surface of the second substrate. According to the configuration of the present invention, it is possible to prevent the occurrence of cracks in the sealing member when sealing the first and second substrates, and to provide the first device having the electron emission element when forming the sealing member. Since the substrate is not heated in the air, the electron-emitting device is not oxidized.

According to a fifth aspect of the present invention, in the flat display device according to the first aspect, the sealing member is formed by laminating a plurality of members having different thermal expansion coefficients. According to a sixth aspect of the present invention, in the flat display device according to the first aspect, the sealing member is formed of a single member.

According to the fifth and sixth aspects of the invention, a specific configuration of the sealing member can be provided. Claim 7
In the method for manufacturing a flat display device according to the invention, the sealing member having a plurality of portions having different thermal expansion coefficients is pre-baked, and then the first substrate having the electron-emitting device and the second substrate having the phosphor are provided.
And the substrate is opposed to the substrate with the sealing member interposed therebetween. Then, the inside of the space surrounded by the first and second substrates and the sealing member is set to a reducing atmosphere or a vacuum atmosphere, and the sealing member is fired. It is characterized by doing.

According to an eighth aspect of the present invention, in the method of manufacturing a flat display device according to the sixth aspect, the sealing member is formed on the second substrate. According to the structure of the seventh and eighth aspects of the present invention, it is possible to prevent the sealing member from cracking when the first and second substrates are sealed, and to provide components inside the first and second substrates. It is possible to manufacture a flat-panel display device that can prevent oxidation of the display.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to the drawings. The structure of the flat panel display according to this embodiment will be described with reference to FIGS. 1 is a cross-sectional view of a flat display device, FIG. 2 is an exploded perspective view of the same, FIG. 3 is an exploded perspective view showing the same portion in an enlarged manner, and FIG. FIG. 5 is a cross-sectional view showing the relationship, and FIG. 5 is a perspective view showing the relationship between the flat display device field emission cathode and the phosphor.

The flat display device of this embodiment is similar to that of FIG.
As shown in (1), a first substrate 1 having a field emission type microcathode (hereinafter referred to as a field emission type cathode) as an electron emission element and a second substrate 2 having a phosphor are arranged to face each other. The substrates 1 and 2 are sealed with a sealing member 3.

As shown in FIG. 2, the first substrate 1 has a quadrangular shape.
It is formed of soda glass having a thermal expansion coefficient of 8.5 ppm / ° C. As shown in FIGS. 1 to 5, on one surface (inner surface) of the first substrate 1, a plurality of cathode electrodes 11 are provided.
Are formed in the form of stripes, and the cathode electrode 11 is formed of, for example, Mo. As shown in FIG. 1, FIG. 2 or FIG.
An insulating layer 12 made of, for example, SiO ₂ is formed on the entire surface of the first substrate 1 on the surface of the first substrate 1. A plurality of gate electrodes 13 are formed on the surface of the insulating layer 12 in a stripe shape in a direction perpendicular to the cathode electrode 11, and the gate electrode 13 is formed of, for example, Mo.

As shown in FIG. 1, FIG. 2 to FIG. 5, at each intersection where the plurality of cathode electrodes 11 and the plurality of gate electrodes 12 intersect, an insulating layer 12 and a gate electrode 1 are provided.
3, a plurality of holes 14 are respectively formed. Inside each of the holes 14 formed at each of these intersections, a field emission microcathode (hereinafter referred to as a field emission cathode) 15 having a conical shape on the cathode electrode 11 is formed. That is, the field emission cathode 15 faces the opening of the hole 14. Field emission type cathode 15
Is formed of, for example, molybdenum M.

The second substrate 2 has a quadrangular shape and is made of, for example, glass having a softening temperature of 390 ° C. and a thermal expansion coefficient of 7.2 ppm / ° C. (ASF1200M, trade name of Asahi Glass Co., Ltd.). As will be described later, the second substrate 2 has a transparent electrode 21 and a phosphor 22 which are more stable at a higher temperature in the air than the field emission type cathode 15. And a glass material having a high softening point. A plurality of transparent electrodes 21 are formed on the surface of the second substrate 2 in a stripe pattern, and the transparent electrodes 21 are formed of, for example, ITO. The surfaces of these transparent electrodes 21 are R (red), G (green),
The B (blue) phosphor 22 is formed.

Then, as shown in FIG. 1 and FIG.
The substrate 1 and the second substrate 2 are arranged to face each other at a predetermined interval with their respective electrode forming surfaces facing each other. The first substrate 1 and the second substrate 2 are hermetically sealed by a sealing member 3 interposed between the respective peripheral portions.

The structure of the sealing member 3 will be described. As described above, the glass material forming the first substrate 1 and the glass material forming the second substrate 2 have different thermal expansion coefficients, respectively, and the thermal expansion coefficient of the glass material forming the first substrate 1 is different. Is smaller than the coefficient of thermal expansion of the glass material forming the second substrate 2. The portion of the sealing member 3 close to the first substrate 1 has a coefficient of thermal expansion close to the coefficient of thermal expansion of the first substrate 1, and the portion close to the second substrate 2 is It is configured to have a coefficient of thermal expansion close to the coefficient of thermal expansion.
Therefore, in this embodiment, as shown in FIGS. 1 and 2, for example, the first substrate 1 is made of glass having a thermal expansion coefficient close to that of the first substrate 1 and is bonded to the first substrate 1. A sealing member 31 and a first sealing member 32 made of glass having a thermal expansion coefficient close to that of the second substrate 2 and bonded to the second substrate 2 are laminated and fixed to be integrated. The sealing member 3 is used.

The first sealing member 31 has a softening temperature of 4
It is made of glass (ASF2100: trade name of Asahi Glass Co., Ltd.) having a thermal expansion coefficient of 7.7 ppm / ° C. at 50 ° C. As the second sealing member 32, glass whose thermal expansion coefficient is between the first sealing member 31 and the second substrate 2 is selected. In this embodiment, for example, the distance between the first substrate 31 and the second substrate 32 is 3 mm, and the length of the second sealing member 32 is 2.
7 mm, and the length of the first sealing member 31 is 0.3 mm.

In the sealing member 3, first, a second sealing member 32 is formed on a second substrate 32, and then the first sealing member 31 is laminated and fixed to the second sealing member 32. Formed. Further, the first sealing member 31 is joined to the first substrate 1. That is, the sealing members 3 are all formed on the second substrate 32 side. In addition, the sealing member 3 is configured such that a portion relatively close to the first substrate 1 has a lower softening point.

Further, a plurality of spacers 33 are arranged between the first substrate 1 and the second substrate 2 surrounded by the sealing member 3, and the spacers 33 are provided for each of the substrates 1 and 2. It is joined to the electrode forming surface to keep the space between the substrates 1 and 2.

The inside of the flat display device constituted by the first substrate 1, the second substrate 2, and the sealing member 3 is 1
The airtight container is evacuated to about 0 ^-8 Torr.

A method of manufacturing the flat display device will be described with reference to FIGS. First, the manufacture of the second substrate 2 will be described. As shown in FIG. 6A, a second substrate 2 is prepared, and a transparent electrode 21 is formed on the surface of the second substrate 2 by a method such as sputtering or vacuum deposition by patterning.
(Red), G (green) and B (blue) phosphors 22 are formed by patterning, respectively. Further, a spacer 33 is formed on the second substrate 2.

Next, as shown in FIG. 6B, a glass for the second sealing member 32 is applied to the periphery of the second substrate 2 with a thickness of 2.7 mm. The glass of the second sealing member 32 applied to the second substrate 2 is dried at 150 ° C. in the atmosphere for 30 minutes and then dried in the air or in an oxygen stream.
Preliminary baking is performed at 0 to 380 ° C. for 30 minutes to securely remove the binder, and finally, main baking is performed at 490 ° C. for 10 minutes to produce the second sealing member 32.

Next, as shown in FIG. 6 (c), a glass for the first sealing member 31 is coated at the tip of the second sealing member 32 with a thickness of 0.3 mm after firing using a dispenser. 3mm
Is applied at a thickness (about 0.5 mm). Subsequently, the glass of the first sealing member 31 is heated at 150 ° C. in air for 3 hours.
It is dried by holding for 0 minutes, and then calcined at 380 ° C. for 30 minutes in the air to completely remove the binder. Thus, the second sealing member 32 is manufactured.

Next, the manufacture of the first substrate 1 will be described. A first substrate 1 is prepared as shown in FIG.
Next, as shown in FIG. 7B, a cathode electrode 11 is patterned and formed on the surface of the first substrate 1 by a method such as sputtering or vacuum deposition, and then formed on the cathode electrode 11 by a method such as sputtering or vacuum deposition. The insulating layer 12 is formed by lamination, and then the gate electrode 13 is patterned on the insulating layer 11 by a method such as sputtering or vacuum deposition. Then, a plurality of holes 1 penetrating through the electrode 13 and the insulating layer 12 are formed at the intersection of the cathode electrode 11 and the gate electrode 13 by a method such as wet edging.
Then, a field emission cathode 15 having a conical shape on the cathode electrode 11 is formed inside the hole 14 by a method such as vapor deposition or sputtering.

An air supply port 16a is formed on one side of the first substrate 1, and an air supply pipe 41 is connected thereto.
The exhaust port 16b is formed at a position farthest from the exhaust pipe 1 and the exhaust pipe 42 is connected thereto.

Next, as shown in FIG. 8, the second substrate 2 is placed on the first substrate 1 by using a positioning jig. Then, the first substrate 1 and the second substrate 2 are placed inside the firing furnace 51 and placed on the support table 52, and the load 54 is placed on the upper side. And fired. Air was passed through the firing furnace 51.

In this case, for example, H ₂ gas is flowed from an air supply pipe 41 provided in advance to the first substrate 1 into a container including the first substrate 1, the second substrate 2, and the sealing member 3 before heating. The H ₂ gas is discharged through an exhaust pipe 42. Thus, firing is performed after the inside of the container is replaced with H ₂ gas, and oxidation of the field emission cathode 15 during firing is prevented.

As described above, in order to join the first substrate 1 and the second substrate 2 via the sealing member 3, the sealing member 3 is
In the step of heating and melting at 0 ° C. or higher, the sealing member 3 is baked by setting the inside of the space surrounded by the first and second substrates 1 and 2 and the sealing member 3 to a reducing atmosphere or a vacuum atmosphere.

After firing, the air supply pipe 41 is sealed, and the exhaust pipe 42
After the inside of the container is evacuated through an exhaust pipe 42 using a rotary pump or a turbo pump, a baking of a phosphor and degassing of an emitter are performed, and the exhaust pipe 42 is sealed. Stop. Further, a getter (not shown) was vapor-deposited and operated, and the inside of the container was evacuated to a high vacuum.

In this manner, when the first substrate 1 and the second substrate 2 are sealed, the occurrence of cracks at the joint between the substrates 1 and 2 and the sealing member 3 is prevented, and
A flat display device capable of preventing the components inside the substrate 1 and the second substrate 2 from being oxidized is manufactured.

The flat display device has a structure in which the gate electrode 13 and the field emission cathode 15 on the first substrate 1 are provided.
When the electrolysis is applied between the electrodes, a current is emitted from the tip of the field emission cathode 15 by the field emission effect. At this time, when a voltage is applied to the transparent electrode 21 of the second substrate 2 facing the field emission cathode 15, the phosphor 22 is irradiated with electrons, and the phosphor 22 is excited to emit light, thereby performing display.

In this flat-panel display device, the sealing member 3 is moved to the first sealing member 31 having a thermal expansion coefficient close to that of the first substrate 1 and the thermal expansion coefficient of the second substrate 2. A second sealing member 32 having an approximate thermal expansion coefficient is laminated and integrated, and the thermal expansion coefficient of the sealing member 3 is made to correspond to each thermal expansion coefficient of the first substrate 1 and the second substrate 2. So that they are partially different. Then, the first sealing member 31 is joined to the first substrate 1, and the second sealing member 32 is joined to the second substrate 2. Therefore, when the thermal expansion coefficient of the first substrate 1 and the thermal expansion coefficient of the second substrate 2 are different, the first substrate 1 and the sealing member 31 and the second substrate and the sealing member 31 are different from each other. Is small, the occurrence of cracks at the joint between the sealing member and the substrate due to the difference in the coefficient of thermal expansion is suppressed, and the first substrate 1 and the second substrate 2 are separated. The occurrence of cracks in the sealing member 3 during sealing can be prevented.

In particular, when the thermal expansion coefficient of the first substrate 1 having the field emission type cathode 15 which is an electron-emitting device which is susceptible to oxidation in air is set to be small, the sealing member 3 and the first substrate 1 This is effective because cracks between the attachment member 3 and the second substrate can be reliably prevented from occurring.

The sealing member 3 is relatively fixed to the first substrate 1.
Is configured to have a lower softening point.
In addition to preventing the occurrence of cracks in the sealing member 3 when the first and second substrates 1 and 2 are sealed, the first substrate 1 having the field emission cathode 15 and the sealing member 3 The sealing can be performed at a low temperature, and the degree of oxidation of the field emission cathode 15 can be minimized.

Further, in the manufacturing method according to the above-described embodiment, since the sealing member 3 is entirely formed on the second substrate 2, the sealing member 3 (the second sealing member 32) is not formed. Oxidation of the field emission cathode 15 provided on the first substrate 1 can be avoided. That is, when the sealing member 3 is preliminarily baked while maintaining a high temperature in the air, the sealing member 3 is applied only to the first substrate 1 in order to avoid oxidation of the field emission cathode 15. Firing. As a result, the preliminary firing of the sealing member 3 is performed only on the first substrate 1, and the field emission cathode 15 formed on the second substrate 2 is not oxidized by firing.

The transparent electrode 2 formed on the second substrate 2
1 and the phosphor 22 are typically 40 in air.
Sintering at 0 to 600 ° C. is scientifically stable and does not cause any problem in their operation.

On the other hand, as shown in FIG. 10, the first substrate 1 and the second substrate 2 combined via the sealing member 3 are put into a firing furnace 51 and sealed while flowing N ₂ gas. When the attachment member 3 is fired at a high temperature, the field emission cathode 15 of the first substrate 1 is oxidized.

Further, in order to join the first substrate 1 and the second substrate 2 through the sealing member 3, the sealing member 3 is
In the step of heating and melting at a temperature of not less than 0 ° C., the sealing member is baked by setting the inside of the space surrounded by the first and second substrates 1 and 2 and the sealing member 3 to a reducing atmosphere or a vacuum atmosphere. The field emission cathode 15 formed on the substrate 2 is not oxidized. There is no problem in melting the sealing member 3 because the binder has already been removed.

The present invention is not limited to the above-described embodiment, but can be implemented with various modifications. The sealing member is not limited to being formed by laminating two members having different thermal expansion coefficients as shown in the above-described embodiment,
If necessary, three or more members having different thermal expansion coefficients may be laminated. Further, the sealing member may be formed by subjecting a single member to a process of partially varying the coefficient of thermal expansion. For example, in the sealing member 3A shown in FIG. 9, the portion 3a joined to the first substrate 1 has a thermal expansion coefficient similar to that of the first substrate 1, and the portion 3b joined to the second substrate 2 is The substrate 1 has a thermal expansion coefficient similar to that of the substrate 1.

[0055]

According to the flat display device of the first aspect of the present invention, the thermal expansion coefficient of the sealing member is partially varied so as to correspond to the respective thermal expansion coefficients of the first substrate and the second substrate. Thereby, the difference in the coefficient of thermal expansion between the first substrate and the sealing member and between the second substrate and the sealing member is small, and the bonding between the sealing member and the substrate due to the difference in the coefficient of thermal expansion. The generation of cracks in the portion can be suppressed, and the generation of cracks in the sealing member when sealing the first and second substrates can be prevented.

According to the second aspect of the present invention, when the thermal expansion coefficient of the first substrate having the electron-emitting device that is susceptible to oxidation in air is set to be small, the sealing member, the first substrate, and the sealing member Generation of cracks between the substrate and the second substrate can be prevented.

According to the third aspect of the present invention, the first and the second
In addition to preventing the occurrence of cracks in the sealing member at the time of sealing the substrate, the first
Can be performed at a low temperature, and the degree of oxidation of the electron-emitting device can be minimized.

According to the fourth aspect of the present invention, the first and the second
In addition to preventing the occurrence of cracks in the sealing member when sealing the substrate, the first substrate having the electron emitting element is not heated in air when forming the sealing member. Is not oxidized.

According to the invention of claim 5 and the invention of claim 5, a specific configuration of the sealing member can be provided. Claim 7
According to the method of manufacturing a flat display device of the invention, it is possible to prevent the occurrence of cracks in the sealing member when sealing the first and second substrates, and to reduce the number of components inside the first and second substrates. A flat display device that can prevent oxidation can be manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a flat-panel display according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view showing the flat panel display according to the embodiment.

FIG. 3 is an exploded perspective view showing a part of the flat display device according to the embodiment in an enlarged manner.

FIG. 4 is a sectional view showing a relationship between a field emission cathode and a phosphor in the flat panel display according to the embodiment.

FIG. 5 is a perspective view showing a relationship between a field emission cathode and a phosphor in the flat panel display according to the embodiment.

FIG. 6 is a view showing a step of manufacturing the first substrate in the flat panel display according to the embodiment.

FIG. 7 is a view showing a step of manufacturing a second substrate in the flat-panel display according to the embodiment.

FIG. 8 is a view showing a step of manufacturing the flat panel display according to the embodiment.

FIG. 9 is a sectional view showing a sealing member according to the second embodiment.

FIG. 10 is a diagram showing a step of manufacturing a flat panel display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... 1st board | substrate, 2 ... 2nd board | substrate, 3 ... Sealing member 11 ... Cathode electrode, 12 ... Insulating layer, 13 ... Gate electrode, 15 ... Field emission cathode, 21 ... Transparent electrode, 22 ... Phosphor , 31: a first sealing member, 32: a second sealing member.

Claims (8)

[Claims] 1. A first substrate having an electron-emitting device and a phosphor having a thermal expansion coefficient different from a thermal expansion coefficient of the first substrate, the phosphor having a phosphor and being arranged to be opposed to and separated from the first substrate. A second substrate; and a sealing member disposed between the first substrate and the second substrate to seal both of the substrates, wherein the sealing member includes the first substrate. Has a thermal expansion coefficient close to the thermal expansion coefficient of the first substrate, and a portion close to the second substrate has a thermal expansion coefficient close to the thermal expansion coefficient of the second substrate. A flat-panel display device comprising: 2. The thermal expansion coefficient of the first substrate is the second substrate.
The flat display device according to claim 1, wherein the thermal expansion coefficient of the substrate is smaller than that of the substrate. 3. The flat display device according to claim 1, wherein the sealing member has a softening point that decreases from the second substrate toward the first substrate. 4. The flat display device according to claim 1, wherein the sealing member is formed on the second substrate. 5. The flat display device according to claim 1, wherein the sealing member is formed by laminating a plurality of members having different thermal expansion coefficients. 6. The flat display device according to claim 1, wherein the sealing member is formed of a single member. 7. A sealing member having a plurality of portions having different thermal expansion coefficients is pre-baked, and then a first substrate having an electron-emitting device and a second substrate having a phosphor are sandwiched by the sealing member. Wherein the inside of the space surrounded by the first and second substrates and the sealing member is reduced or evacuated, and the sealing member is fired. Manufacturing method. 8. The method according to claim 7, wherein the sealing member is formed on the second substrate.