JP2003123673A - Flat display device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat display device and its manufacturing method which can easily and securely seal in vacuum atmosphere. SOLUTION: A vacuum envelope 10 of the plane display device is provided a front board 11 and a back board 12 arranged in opposition, and sealing part sealing periphery parts of each other of the front board and the back board. The sealing part includes a high melting-point conductive member 18 of a rectangular frame shape and a sealing material 30. The high melting-point conductive member is endowed with higher melting point than that of the sealing material, and at the same time, is provided with four or more protruded parts 18a, 18b, 18c, 18d protruding outside.

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 having a flat shape, and more particularly to a flat display device using a large number of electron-emitting devices.

[0002]

2. Description of the Related Art In recent years, various flat display devices have been developed as next-generation lightweight and thin display devices which will replace cathode ray tubes (hereinafter referred to as CRTs). Such flat display devices include a liquid crystal display (hereinafter, referred to as LCD) that controls the intensity of light by utilizing the alignment of liquid crystals, a plasma display panel (hereinafter, referred to as PDP) that emits a phosphor by ultraviolet rays of plasma discharge. Field emission display (hereinafter referred to as FED) in which a phosphor is caused to emit light by an electron beam of a field emission electron-emitting device.

For example, an FED generally has a front substrate and a rear substrate which are opposed to each other with a predetermined gap,
These substrates form a vacuum envelope by bonding their peripheral portions to each other via a rectangular frame-shaped side wall. A phosphor screen is formed on the inner surface of the front substrate,
A large number of electron-emitting devices are provided on the inner surface of the back substrate as electron-emitting sources for exciting phosphors to emit light.

Further, in order to support the atmospheric pressure load applied to the back substrate and the front substrate, a plurality of supporting members are arranged between these substrates. The potential on the rear substrate side is almost the ground potential, and the anode voltage is applied to the phosphor screen.
Then, the red, green, and blue phosphors forming the phosphor screen are irradiated with electron beams emitted from a large number of electron-emitting devices, and the phosphors emit light to display an image.

In such a display device, the thickness of the display device can be reduced to about several millimeters, and C, which is currently used as a display for televisions and computers, is used.
Compared with RT, it is possible to achieve weight reduction and thickness reduction.

[0006]

In the above FED, it is necessary to make the inside of the envelope vacuum. Further, also in the PDP, it is necessary to evacuate the PDP once and then fill the discharge gas.

As means for evacuating the envelope, first, the front substrate, the back substrate, and the side walls, which are the constituent members of the envelope, are heated and joined in the atmosphere with a suitable sealing material, and then the front face is joined. After exhausting the inside from an exhaust pipe provided on the substrate or the back substrate, there is a method of vacuum-sealing the exhaust pipe. However, in the flat type envelope, the exhaust rate through the exhaust pipe is extremely slow and the attainable vacuum degree is poor, so that there are problems in mass productivity and characteristics.

As a method for solving this problem, for example, Japanese Unexamined Patent Publication No. 2001-229825 shows a method in which a front substrate and a rear substrate forming an envelope are finally assembled in a vacuum chamber.

Here, first, the front substrate and the rear substrate arranged in the vacuum chamber are sufficiently heated. this is,
This is to reduce gas emission from the inner wall of the envelope, which is the main cause of deterioration of the vacuum degree of the envelope. Then, when the front substrate and the rear substrate are cooled and the degree of vacuum in the vacuum chamber is sufficiently improved, a getter film for improving and maintaining the degree of vacuum of the envelope is formed on the phosphor screen. After that, the front substrate and the back substrate are heated again to a temperature at which the sealing material melts, and cooled in a state where the front substrate and the back substrate are combined at predetermined positions until the sealing material solidifies.

The vacuum envelope manufactured by such a method has both a sealing step and a vacuum sealing step, does not require a great amount of time for exhausting the exhaust pipe, and has an extremely good vacuum. You can get a degree.

However, in the above-mentioned method, the sealing process performed in vacuum includes heating, alignment and cooling, and the front substrate and the back surface are covered for a long time while the sealing material is melted and solidified. The substrate and must be kept in place. In addition, the front substrate and the rear substrate thermally expand due to heating and cooling during sealing, and the alignment accuracy is likely to deteriorate. Further, there is a problem in productivity and characteristics associated with the sealing such that the getter film is deteriorated by heating during the sealing.

The present invention has been made in view of the above points, and an object thereof is to provide a flat display device capable of easily and surely sealing in a vacuum atmosphere, and a manufacturing method thereof. is there.

[0013]

In order to solve the above problems, in a flat panel display device according to an aspect of the present invention, a front substrate and a rear substrate which are arranged to face each other, and a peripheral portion of the front substrate and the rear substrate are provided with each other. A sealed sealing portion, and an envelope having the sealing portion, the sealing portion includes a rectangular frame-shaped high melting point conductive member and a sealing material, the high melting point conductive member is the sealing member. It is characterized by having a melting point higher than that of the adhesive material and having four or more protruding portions protruding outward.

A flat panel display device according to another aspect of the present invention includes a front substrate and a rear substrate which are arranged to face each other, and a sealing portion which seals the peripheral portions of the front substrate and the rear substrate to each other. An envelope having, a phosphor screen formed on the inner surface of the front substrate, an electron emission source provided on the back substrate, for emitting an electron beam to the phosphor screen and causing the phosphor screen to emit light, The sealing portion includes a rectangular frame-shaped high-melting point conductive member and a sealing material, the high-melting point conductive member has a melting point higher than the sealing material, the outside It is characterized by having four or more protrusions protruding inward.

Further, a method of manufacturing a flat panel display device according to an aspect of the present invention includes a front substrate and a rear substrate which are arranged to face each other, a sealing material and a high melting point conductive member having a melting point higher than that of the sealing material. In a method for manufacturing a flat panel display device including an envelope having a front substrate and a rear substrate, in which peripheral portions are sealed to each other, a rectangle having four or more protruding portions protruding outward. A frame-shaped high-melting-point conductive member is prepared, and the high-melting-point conductive member is arranged between the peripheral portions of the front substrate and the back substrate, and between the front substrate and the high-melting-point conductive member, and A sealing material is arranged between the back substrate and the high-melting point conductive member, and the high-melting point conductive member is energized through the protrusion to melt the sealing material and the front substrate and The peripheral parts of the back substrate are It is characterized by wearing.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments in which a flat panel display device according to the present invention is applied to an FED will be described in detail with reference to the drawings.

As shown in FIGS. 1-3, this FED
Includes a front substrate 11 and a rear substrate 12 each made of rectangular glass as an insulating substrate, and these substrates are opposed to each other with a gap of 1.6 mm. The size of the rear substrate is slightly larger than that of the front substrate, and a lead line (not shown) for inputting a video signal, which will be described later, is formed on the outer peripheral portion thereof. The front substrate 11 and the rear substrate 12 are joined together at their peripheral portions via side walls 18 having a substantially rectangular plate frame shape to form a flat rectangular vacuum envelope 10 whose interior is maintained in a vacuum state. ing.

As the side wall 18, a high melting point conductive member having a higher melting point and conductivity than the sealing material described later and having conductivity, for example, an iron-nickel alloy is used. In addition, as the high melting point conductive member having conductivity, Fe, Cr,
A material containing at least Ni or Al is used. As shown in FIGS. 1, 2 and 4, the sidewall 1
8 has projecting portions 18a, 18b, 18c, 18d that project outward from the respective corner portions along the diagonal axis direction. The side wall 18 is, for example, as the sealing material 30,
Back substrate 1 made of indium or indium alloy
2 and the front substrate 11 are sealed.

In the sealed state, the protruding portions 18a, 18b, 18c and 18d of the side wall 18 respectively project outside the front substrate 11 and extend to the vicinity of the corner of the rear substrate 12. The protruding portion 18
a, 18b, 18c, 18d are FE, as will be described later.
In the manufacturing process of D, it can function as a terminal for applying a voltage to the side wall 18 and also as a grip portion when positioning the side wall.

As shown in FIGS. 2 and 3, a plurality of plate-shaped spacers 1 are provided inside the vacuum envelope 10 to support an atmospheric pressure load applied to the front substrate 11 and the rear substrate 12.
4 are provided. These spacers 14 are arranged in a direction parallel to the short side of the vacuum envelope 10, and are arranged at predetermined intervals along the direction parallel to the long side. The shape of the spacer 14 is not particularly limited to this, and for example, a columnar spacer or the like can be used.

A phosphor screen 16 shown in FIG. 5 is formed on the inner surface of the front substrate 11. This phosphor screen 16 includes red, green and blue stripe phosphor layers,
Further, stripe-shaped black light absorption layers 20 as non-light emitting portions located between these phosphor layers are arranged side by side. The phosphor layer extends in a direction parallel to the short side of the vacuum envelope and is arranged at a predetermined interval along the direction parallel to the long side. In addition, the phosphor screen 1
A metal back layer 17 made of, for example, an aluminum layer is vapor-deposited on the surface 6.

On the inner surface of the rear substrate 12, a large number of electron-emitting devices 22 each emitting an electron beam are provided as electron-emitting sources for exciting the phosphor layer of the phosphor screen 16. These electron-emitting devices 22 are arranged in a plurality of columns and a plurality of rows corresponding to each pixel. More specifically, a conductive cathode layer 24 is formed on the inner surface of the back substrate 12, and a silicon dioxide film 26 having a large number of cavities 25 is formed on the conductive cathode layer. A gate electrode 28 made of molybdenum, niobium, or the like is formed on the silicon dioxide film 26.
Then, each cavity 2 is formed on the inner surface of the rear substrate 12.
A cone-shaped electron-emitting device 22 made of molybdenum or the like is provided inside 5.

In the FED constructed as described above,
The video signal is input to the electron-emitting device 22 and the gate electrode 28 formed in a simple matrix method. When the electron-emitting device 22 is used as a reference, when the brightness is highest, +
A gate voltage of 100V is applied. Further, +10 kV is applied to the phosphor screen 16. This allows
An electron beam is emitted from the electron emitting element 22. The magnitude of the electron beam emitted from the electron-emitting device 22 is modulated by the voltage of the gate electrode 28, and the electron beam excites the phosphor layer of the phosphor screen 16 to emit light, thereby displaying an image. .

Next, a method of manufacturing the FED configured as above will be described in detail. First, the electron-emitting device is formed on the plate glass for the back substrate. In this case, the matrix-shaped conductive cathode layer 24 is formed on the plate glass,
On this conductive cathode layer, for example, thermal oxidation method, CVD
The insulating film 26 of a silicon dioxide film is formed by a sputtering method or a sputtering method.

Thereafter, a metal film such as molybdenum or niobium for forming a gate electrode is formed on the insulating film 26 by, for example, a sputtering method or an electron beam evaporation method. Next, a resist pattern having a shape corresponding to the gate electrode to be formed is formed on the metal film by lithography. Using the resist pattern as a mask, the metal film is etched by a wet etching method or a dry etching method to form a gate electrode 28.

Next, the resist pattern and the gate electrode 2
The insulating film 26 is etched using 8 as a mask by wet etching or dry etching to form a cavity 25. Then, after removing the resist pattern, electron beam evaporation is performed from a direction inclined by a predetermined angle with respect to the surface of the rear substrate 12, thereby forming the gate electrode 28.
A release layer made of, for example, aluminum or nickel is formed thereon. Then, for example, molybdenum is deposited as a material for forming a cathode by an electron beam evaporation method from a direction perpendicular to the surface of the back substrate 12. by this,
The electron-emitting device 22 is formed inside each cavity 25. Then, the peeling layer is removed together with the metal film formed thereon by the lift-off method. Then, the back substrate 12
A plate-shaped support member 14 is sealed on the upper part with a low melting point glass.

On the other hand, the phosphor screen 16 is formed on the plate glass which becomes the front substrate 11. For this, a plate glass having the same size as the front substrate 11 is prepared, and a stripe pattern of a phosphor layer is formed on the plate glass by a plotter machine. The plate glass on which the phosphor stripe pattern is formed and the plate glass for the front substrate are placed on a positioning jig and set on an exposure table, so that the phosphor screen 16 is formed by exposure and development. Next, the phosphor screen 16
And a metal back layer 17 made of an aluminum film.
To form.

Indium is applied as the sealing material 30 to the rear substrate 12 having the supporting member 14 sealed as described above, the front substrate 11 having the phosphor screen 16 formed thereon, and the sealing surface of the side wall 18. Here, for example, the rear substrate 12
And indium is applied to the inner surface of the peripheral portion of the front substrate 11. After that, these are placed in the vacuum processing apparatus 100 in a state of being opposed to each other with a predetermined gap. For the series of steps described above, for example, the vacuum processing apparatus 1 as shown in FIG.
00 is used.

The vacuum processing apparatus 100 includes a load chamber 101, a baking chamber, and an electron beam cleaning chamber 1 which are arranged in order.
02, a cooling chamber 103, a getter film deposition chamber 104, an assembly chamber 105, a cooling chamber 106, and an unload chamber 107. Each of these chambers is configured as a processing chamber capable of vacuum processing, and all the chambers are evacuated when manufacturing the FED. The adjacent processing chambers are connected by a gate valve or the like.

The above-mentioned rear substrate 12, side wall 18, and front substrate 11 are put into the load chamber 101,
After making the inside a vacuum atmosphere, baking and electron beam cleaning room 1
Sent to 02. In the baking / electron beam cleaning chamber 102, the assembly and the front substrate are heated to a temperature of 350 ° C. to release the surface adsorption gas of each member.

Simultaneously with heating, an electron beam is applied to the phosphor screen surface of the front substrate 11 and the electron-emitting device surface of the rear substrate 12 from an electron beam generator (not shown) attached to the baking / electron beam cleaning chamber 102. Irradiate. Since this electron beam is deflected and scanned by the deflecting device mounted outside the electron beam generator, the entire surface of the phosphor screen surface and the electron-emitting device surface can be cleaned with the electron beam.

After heating and electron beam cleaning, the assembly and the front substrate are sent to the cooling chamber 103 and cooled to a temperature of about 100 ° C., for example. Subsequently, the assembly and the front substrate are sent to a vapor deposition chamber 104 for forming a getter film, where a Ba film is vapor deposited as a getter film on the outside of the phosphor screen. The Ba film can prevent the surface from being contaminated with oxygen, carbon, etc., so that the active state can be maintained.

Subsequently, the rear substrate 12, the side wall 18, and the front substrate 11 are sent to the assembly chamber 105. This assembly room 1
In 05, these members are heated to a temperature of, for example, about 130 ° C., and both substrates are superposed at a predetermined position. On this occasion,
Protrusions 18a, 18b, 18c provided on the side wall 18,
By holding 18d, the side wall is held and the rear substrate 1
2, the side wall 18 and the front substrate 11 are positioned relative to each other. Further, for example, the protruding portion 1 of the side wall 18 on the rear substrate 12
Markings corresponding to 8a, 18b, 18c, and 18d are provided in advance, and the side wall 18 can be accurately aligned with the rear substrate while monitoring the protrusions and the markings. The protrusions 18a, 18b, 18c, 1
Since 8d projects outward from the side wall 18, the assembly chamber 1
Also in 05, the side wall 18 is formed by utilizing these protrusions.
Can be easily chucked, transported and aligned.

Subsequently, of the protrusions 18a, 18b, 18c and 18d of the side wall 18 which is a high melting point conductive member, two electrodes which are opposed to each other, for example, the protrusions 18a and 18c, are brought into contact with the electrodes to contact the side wall 18. A direct current of 300 A is applied for 40 seconds. Then, this current also flows to indium at the same time,
The side wall 18 and indium generate heat. Thereby, indium is heated to about 160 to 200 ° C. and melted. At this time, a pressure of about 50 kgf is applied from both sides to the front substrate 11 and the rear substrate 12 which are overlapped.

After that, the energization of the side wall 18 is stopped, and the heat of the sealing area, that is, the side wall 18 and the sealing material 30 is quickly transferred to the surrounding front substrate 11 and rear substrate 12 to solidify the indium. Let This allows the sidewall 18
The front substrate 11 and the rear substrate 12 are sealed with the sealing material 30 to form the vacuum envelope 10. The assembly of the vacuum envelope 10 sealed in about 10 seconds after the energization was stopped
Carry out from 5. The vacuum envelope 10 thus formed is cooled to room temperature in the cooling chamber 106,
It is taken out from the unload chamber 107.

According to the FED and the method of manufacturing the same configured as described above, the back substrate 12, the side wall 18 and the front substrate 11 are sealed in a vacuum atmosphere, so that baking and electron beam cleaning are used in combination. The surface adsorption gas can be sufficiently released, and the getter film is not oxidized, so that a sufficient gas adsorption effect can be maintained. Further, a high melting point conductive member such as an iron-nickel alloy is used for the side wall 18, and the projecting portions 18a, 18b, 18 that can be gripped by the side wall are used.
By providing c and 18d, the side wall 18 can be easily chucked and transported even in the vacuum apparatus, the side wall 18 can be aligned with high accuracy based on the corner portion, and the short time can be achieved. It can be sealed with.

Furthermore, in order to energize the high melting point conductive member,
When the indium melts, the cross-sectional area non-uniformity of the molten indium becomes large and the indium is broken,
It is possible to prevent the glass from breaking due to local heat generation. Therefore, the vacuum envelope can be easily and reliably sealed. Further, by sealing the rear substrate 12, the front substrate 11, and the side wall 18 with indium, a lead-free flat display device can be obtained.

The protrusion of the high melting point conductive member forming the side wall is not limited to the above-described embodiment.
That is, four or more protruding portions may be provided apart from each other, and the protruding portions are not limited to the corner portions of the side wall, and can be provided at arbitrary positions. As shown in FIG. 7, according to the FED according to the second embodiment of the present invention, the side wall 18 as the high melting point conductive member is formed in a rectangular frame shape and protrudes outward from the central portion of each side. The protruding portions 18a, 18b,
18c and 18d are provided. Also in this case, the electrodes can be brought into contact with the opposing protruding portions 18a and 18c to apply a direct current, and the envelope can be sealed as in the first embodiment described above. Other configurations are the same as those in the first embodiment.

In the above-described first embodiment, each projecting portion of the side wall 18 is configured to extend to the vicinity of the corner portion of the back substrate 12, but the third embodiment of the present invention shown in FIG. According to the FED of FIG.
The a, 18b, 18c and 18d extend beyond the peripheral edge of the back substrate 12 to the outside of the back substrate. The other structure is the same as that of the first embodiment described above, and the same portions are denoted by the same reference numerals and detailed description thereof is omitted. Further, the FED having the above configuration is also manufactured by the same method as in the above-described first embodiment.

According to the third embodiment, it is possible to obtain the same operation and effect as those of the first embodiment described above, and at the same time, each protrusion of the side wall protrudes to the outside of the back substrate. Therefore, it becomes possible to more easily grip and position the side wall in the manufacturing process.

Besides, the present invention is not limited to the above-mentioned embodiments, but can be variously modified within the scope of the present invention. For example, the current supplied to the high-melting point conductive member is not limited to direct current, and commercial frequency or high frequency alternating current may be used. Further, the present invention is not limited to a flat panel display device that requires a vacuum envelope such as an FED, but is also effective for other display devices such as a PDP in which a discharge gas is injected after a vacuum is made. As an electron-emitting device, pn
Type cold cathode device or a surface conduction electron emitting device may be used.

[0042]

As described above in detail, according to the present invention, it is possible to provide a flat display device capable of easily and reliably sealing in a vacuum atmosphere, and a manufacturing method thereof.

[Brief description of drawings]

FIG. 1 is a perspective view showing an FED according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a state in which a front substrate of the FED is removed.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a plan view showing a side wall of the FED.

FIG. 5 is a plan view showing a phosphor screen of the FED.

FIG. 6 is a diagram schematically showing a vacuum processing apparatus used for manufacturing the FED.

FIG. 7 is a plan view showing a sidewall of an FED according to a second embodiment of the present invention.

FIG. 8 is a perspective view showing an FED according to a third embodiment of the present invention.

[Explanation of symbols]

10 ... Vacuum envelope 11 ... Front substrate 12 ... Rear substrate 14 ... Support member 16 ... Phosphor screen 17 ... Metal back layer 18 ... Side wall 18a, 18b, 18c, 18d ... Projection 22 ... Electron emitting device 30 ... Sealing material 100 ... Vacuum processing device

Continued front page    (72) Inventor Akiyoshi Yamada             2 shares, 1-9-1 Harara-cho, Fukaya City, Saitama Prefecture             Company Toshiba Fukaya Factory (72) Inventor Koji Nishimura             2 shares, 1-9-1 Harara-cho, Fukaya City, Saitama Prefecture             Company Toshiba Fukaya Factory F-term (reference) 5C012 AA01 AA05 BC03                 5C036 EE14 EF01 EF06 EF08 EG02                       EG06 EH04 EH11

Claims (12)

[Claims] 1. An envelope having a front substrate and a rear substrate which are arranged opposite to each other, and a sealing portion which seals the peripheral portions of the front substrate and the rear substrate to each other, wherein the sealing portion is A rectangular frame-shaped high-melting-point conductive member and a sealing material, wherein the high-melting-point conductive member has a melting point higher than that of the sealing material, and four or more protrusions protruding outward. A flat panel display device having a portion. 2. An envelope having a front substrate and a rear substrate that are arranged opposite to each other, and a sealing portion that seals the peripheral portions of the front substrate and the rear substrate to each other, and an inner surface of the front substrate. The formed phosphor screen and an electron emission source which is provided on the back substrate and emits an electron beam to the phosphor screen to cause the phosphor screen to emit light, and the sealing portion has a rectangular frame shape. The high melting point conductive member includes a high melting point conductive member and a sealing material, and the high melting point conductive member has a melting point higher than that of the sealing material and has four or more protruding portions protruding outward. A flat-panel display device characterized by being. 3. The flat panel display device according to claim 1, wherein the projecting portion projects from each corner of the high melting point conductive member. 4. The flat panel display device according to claim 1, wherein the projecting portion projects from substantially the center of each side of the high melting point conductive member. 5. The projecting portion of the high melting point conductive member includes a projecting portion projecting outward from at least one of the front substrate and the back substrate. 2. A flat panel display device according to item 1. 6. The flat panel display device according to claim 1, wherein the sealing material is a conductive material. 7. The flat panel display device according to claim 6, wherein the sealing material is indium or an alloy containing indium. 8. The high melting point conductive member is made of Fe, Cr, N.
8. The flat panel display device according to claim 1, which contains at least one of i and Al. 9. A front substrate and a rear substrate which are arranged to face each other, a sealing material and a high melting point conductive member having a melting point higher than that of the sealing material, and the peripheral portions of the front substrate and the rear substrate are sealed to each other. In the method for manufacturing a flat panel display including an envelope having the sealed portion, the high melting point conductive member having a rectangular frame shape having four or more protruding portions protruding outward is prepared, The high melting point conductive member is disposed between the peripheral portions of the substrate and the rear substrate, and the front substrate and the high melting point conductive member are sealed and the back substrate and the high melting point conductive member are sealed. By disposing an adhesive and energizing the high-melting point conductive member through the protrusion, the sealing material is melted and the peripheral portions of the front substrate and the rear substrate are sealed to each other. Method for manufacturing flat display device. 10. The front substrate, the rear substrate, and the side wall are arranged in a vacuum atmosphere, and the protrusion is gripped to position the high-melting-point conductive member with respect to the front substrate and the rear substrate. A method for manufacturing a flat panel display device, comprising energizing a conductive member. 11. The sealing material is indium or an alloy containing indium, wherein the sealing material is indium or an alloy containing indium.
A method of manufacturing the flat panel display device according to. 12. The high melting point conductive member is made of Fe, Cr,
12. The method for manufacturing a flat panel display device according to claim 9, wherein the flat display device contains at least either Ni or Al.