JP2003242913A - Flat display device and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flat display device which can be easily sealed in vacuum environment at low cost, and to provide a manufacturing method of the same. <P>SOLUTION: A vacuum envelope 18 of the display device is composed of a front base plate 12 and a back base plate 1 facing each other, and a sealing part 13 sealing the peripheral part of the front base plate and the back base plate. The sealing part includes a frame-shaped jointing member 20 formed by pressing a seamless frame-shaped thin plate, and sealing members 22a, 22b sealing the gap between the front base plate and the back base plate, and the jointing member. The jointing member has conductivity and a melting point or a softening joint higher than that of the sealing member. <P>COPYRIGHT: (C)2003,JPO

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 front substrate and a rear substrate which are arranged to face each other, and a manufacturing method thereof.

[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) that emits a phosphor by an electron beam of a field emission type electron emission device, and a surface conduction electron emission display that emits a phosphor by an electron beam of a surface conduction type electron emission device (hereinafter referred to as FED). Less than,
SED)) and so on.

For example, an FED generally has a front substrate and a rear substrate which are arranged to face each other with a predetermined gap, and these substrates are formed by joining peripheral portions to each other via a rectangular frame-shaped side wall. It constitutes a vacuum envelope.
A phosphor screen is formed on the inner surface of the front substrate, and a large number of electron-emitting devices are provided on the inner surface of the rear substrate as electron sources for exciting the 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 phosphor layers that form the phosphor screen are irradiated with the electron beams emitted from the electron-emitting devices to cause the phosphors to emit light, thereby displaying 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. Also in the PDP, it is necessary to evacuate the inside of the envelope once and then fill the discharge gas. As means for evacuating the envelope, for example, Japanese Unexamined Patent Application Publication No. 2001-229825 discloses a method of performing final assembly of a front substrate and a rear substrate forming the envelope 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. Then, the front substrate and the back substrate are bonded together via the sealing material, and the front substrate and the back substrate are heated again to a temperature at which the sealing material melts. Then, the front substrate and the rear substrate are combined in a predetermined position and cooled until the sealing material is solidified.

The vacuum envelope manufactured by such a method has both a sealing step and a vacuum sealing step, and does not require the time required for exhausting the inside of the envelope using an exhaust pipe. In addition, a very good degree of vacuum can be obtained.

However, in the above method, the sealing process performed in vacuum includes heating, positioning, 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 as deterioration of the getter film due to heating during sealing. In addition, for FED, etc., the gap between the front substrate and the rear substrate is 1 m.
In many cases, a side wall made of glass or the like is used, and the cost of processing the side wall is a problem.

The present invention has been made in view of the above points, and an object thereof is to provide a flat-panel display device which can be easily sealed in a vacuum atmosphere at low cost, and a manufacturing method thereof. To do.

[0011]

In order to solve the above problems, a flat panel display device according to an aspect of the present invention has 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. A sealing portion that is sealed to each other, and an envelope having the sealing portion, the sealing portion, a frame-shaped joining member press-molded from a seamless frame-shaped thin plate, the front substrate and the back substrate The bonding member includes a sealing material that seals between the bonding member and the bonding member, and the bonding member has electrical conductivity and has a higher melting point or softening point than the sealing material.

According to another aspect of the present invention, there is provided a method of manufacturing a flat panel display device, wherein a front substrate and a rear substrate which are opposed to each other and a sealing portion in which the peripheral portions of the front substrate and the rear substrate are mutually sealed. In the method for manufacturing a flat-panel display device including an envelope having, a seamless frame-shaped thin plate having conductivity and having a melting point or a softening point higher than that of the sealing material is provided. A frame-shaped joining member was formed from the frame-shaped thin plate by press molding, and a sealing material was filled between the front substrate and the back substrate and the joining member, and the sealing material was filled. The front substrate, the back substrate, and the bonding member are aligned in predetermined positions and arranged in a vacuum atmosphere, and the bonding member and the sealing material are heated by energizing the bonding member in the vacuum atmosphere to perform the sealing. Stop energizing after the material melts Te cooled the sealing material, is characterized in that to seal the said front and rear substrates and the joining member.

According to the flat-panel display device and the manufacturing method having the above-described structure, a thin plate press member made of an inexpensive metal or the like is used as the joining member instead of the side wall made of glass or the like, and the front substrate and the rear substrate are used in a vacuum atmosphere. It is possible to easily seal the peripheral edge portion of and to reduce the manufacturing cost.

[0014]

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

As shown in FIGS. 1 and 2, this FED
Includes a transparent rectangular insulating substrate, for example, a back substrate 11 and a front substrate 12 each made of a glass plate having a thickness of 2.8 mm, and these substrates are arranged to face each other with a predetermined gap. The rear substrate 11 and the front substrate 12 are joined together at their peripheral edge portions by a sealing portion 13 to be described later to form a flat rectangular vacuum envelope 18.

Between the rear substrate 11 and the front substrate 12, a large number of spacers 14 each formed in a plate shape or a column shape are arranged in order to maintain the distance between these substrates. Both ends of the spacer 14 are brought into contact with the rear substrate 11 and the front substrate 12, respectively, to support the atmospheric pressure load acting on these substrates, and maintain the distance between the substrates at 1 mm or more, for example, 2.0 mm. There is.

A phosphor screen 16 is formed on the inner surface of the front substrate 12. This phosphor screen 16 is
The red, blue, and green phosphor layers and the black coloring layer are arranged side by side. These phosphor layers are formed in stripes or dots. Also, the phosphor screen 1
A metal back 17 made of aluminum or the like and functioning as an anode electrode is formed on the metal plate 6. On the inner surface of the rear substrate 11, a plurality of electron-emitting devices 2 that emit electrons by field emission are used as electron sources.
4 and a plurality of wirings 15 for driving these electron-emitting devices.

The sealing portion 13 has a conductive rectangular frame-shaped bonding member 20, and sealing materials 22a and 22b that seal the space between the bonding member and the rear substrate 11 and the front substrate 12. . The joining member 20 has a melting point or a softening point higher than that of the sealing materials 22a and 22b, and is formed by bending a seamless frame-shaped thin plate by press molding.

As shown in FIGS. 2 and 5, the joining member 2
0 indicates a first facing portion 20a facing substantially parallel to the inner surface of the rear substrate 11, a second facing portion 20b facing substantially parallel to the inner surface of the front substrate 12, and a rear substrate and a direction crossing the front substrate. The rising portion 20c extending between the first and second facing portions is integrally formed, and its cross-sectional shape is a crank shape. The thickness of the joining member 20, that is, the height in the direction orthogonal to the inner surfaces of the back substrate 11 and the front substrate 12 is formed to be 1 mm or more.

Then, the first facing portion 20a and the rear substrate 11
And the second facing portion 20b.
The front substrate 12 and the front substrate 12 are sealed by a sealing material 22b. Thereby, the peripheral portions of the rear substrate 11 and the front substrate 12 are airtightly joined to each other via the sealing portion 13. As the sealing materials 22a and 22b, a low melting point metal material, for example, indium is used. As shown in FIG. 1, each corner of the first facing portion 20a is integrally provided with a protrusion 21 to be described later that protrudes outward in the radial direction, and the spacer 14 is formed in a columnar shape. However, these spacers 14 are rectangular thin plate members 2
It is fixed at 6. The thin plate member 26 is arranged substantially in parallel between the back substrate 11 and the front substrate 12, and its peripheral edge portion is fixed on the inner surface of the back substrate 11 via a fixing base 28. Further, in the thin plate member 26, electron beam passage holes 30 are formed at positions corresponding to the electron emitting elements so as not to block the electron beams emitted from the electron emitting elements 24. The outer dimension of the thin plate member 26 is set smaller than the inner dimension of the joining member 20.

In the FED constructed as described above, the electron-emitting device 24 is driven while a predetermined anode voltage is applied to the phosphor screen 16, and the corresponding phosphor layer is generated by the electron beam emitted from the electron-emitting device. Excite. As a result, the phosphor layer emits light to display a desired image.

Next, a method of manufacturing the FED configured as above will be described. First, as shown in FIG. 3, by continuously etching a roll-shaped base material thin plate 32 having a thermal expansion coefficient substantially equal to that of the front substrate 12 and the rear substrate 11, the thin plate member 26 is cut out and the electron beam is removed. The passage hole 30 is formed. At this time, the base material for forming the joining member 20 is cut out from the base material thin plate 32 at the same time.

More specifically, first, a rectangular cutout area 50 corresponding to the thin plate member 26 is defined in the base material thin plate 32, and the mother board is so exposed that only the contour of the cutout area and the electron beam passage hole portion are exposed. A resist layer is formed on the thin plate. In this state, the base material thin plate 32 is etched to form the thin plate member 26. At this time, the frame-shaped cut-out region 5 for forming the joining member 20 is provided outside the cut-out region 50.
2 is defined, and a resist layer is formed on the base material thin plate 32 so that only the contour of the cutout region 52 is exposed. Then, by etching the base material thin plate 32, the frame-shaped base material 54 used for forming the joining member is cut out at the same time as the thin plate member 26.

In addition, at each corner of the frame-shaped cutout region 52, a protruding portion 21 protruding outward is formed. These projecting portions 21 are used as a grip portion when the joining member 20 is conveyed and as a terminal for energization heating during sealing.

The thin plate member 26 cut out from the base material thin plate 32 as described above is fixed on the rear substrate 11 prepared in advance via the fixing table 28. Further, the base material 54 cut out at the same time is mounted between the press dies 60a and 60b as shown in FIG. 4, and press-molded. As a result, the joining member 20 having the desired shape shown in FIG. 5 is molded.

Then, the sealing surfaces of the first and second facing portions 20a, 20b of the joining member 20 are filled with the sealing materials 22a, 22b. Then, the joining member 20, the back substrate 11 and the front substrate 12 prepared in advance are put into a vacuum chamber,
It is aligned at a predetermined relative position in a vacuum atmosphere. In this state, of the protrusions 21 provided on the joining member 20, current is passed from two opposing protrusions 21 to heat the joining member, and the sealing materials 22a and 22b are melted or softened. After that, when the energization of the joining member 20 is stopped, the sealing materials 22a and 22b are rapidly cooled and solidified. As a result, the space between the bonding member 20 and the rear substrate 11 and the space between the bonding member and the front substrate 12 are sealed, and the vacuum envelope 1
8 is formed.

(Example) Similar to the above-described embodiment,
A rear substrate 11 and a front substrate 12 made of a glass plate having a thickness of 2.8 mm are prepared, and the electron-emitting device 2 is formed on the rear substrate.
4, wiring 15 and the like are formed. Further, the phosphor screen 16 and the metal back 17 are formed on the inner surface of the front substrate 12.

An iron-nickel alloy having a thickness of 0.25 mm is used for the joining member 20 and the thin plate member 26, and the thermal expansion coefficients thereof are almost the same as those of the back substrate and the front substrate. Indium that melts at about 150 ° C. is used for the sealing materials 22a and 22b.

The base material 54 for the joining member 20 is the thin plate member 2
The same roll-shaped base material thin plate 32 as 6 is cut into a frame-shaped integral body having a width of 10 mm by etching. The base material 54 is pressed and bent into a predetermined shape to obtain the joining member 20. Therefore, the joint member 20 having no seam and excellent in airtightness can be obtained. Further, the joining member can be formed into an arbitrary thickness by press working, and the side wall member can be substituted.

Here, the base material 54 is cut out as a frame-shaped integrated body, but the inner region of the frame is not scrapped and is utilized as the thin plate member 26, so the base material thin plate 32 is efficiently used. can do.

The sealing material 22 is attached to the sealing surfaces of the first and second facing portions 20a and 20b of the joint member 20 thus molded.
Indium as a and 22b each has a thickness of 0.3 mm
To fill. Next, the bonding member 20, the front substrate 12, and the rear substrate 11 are heated to 100 ° C. in a vacuum atmosphere in a vacuum chamber.
Align in place at the temperature of. Then, a current of 150 A is applied from the protruding portion 21 to the joining member 20 for 40 seconds to heat indium to 180 ° C. to melt it,
Stop energizing. 150 seconds after stopping the power supply, the indium was cooled to 120 ° C. and solidified, and the vacuum envelope 18
Is completed.

According to the FED and the manufacturing method thereof having the above-described structure, when the vacuum envelope 18 is formed, only the sealing portion 13 is locally heated and quickly cooled by heat transfer to the surroundings. Therefore, there is almost no thermal expansion of the front substrate and the rear substrate, and the sealing process can be performed in a short time while maintaining high positional accuracy. Further, since the joining member is formed by pressing a frame-shaped thin plate of a seamless single body, by sealing using this joining member,
A vacuum envelope having high airtightness can be obtained, and at the same time, manufacturing cost can be reduced. In particular, in the case of the structure in which the thin plate member 26 is used inside the vacuum envelope, the frame-shaped base material for the joining member and the thin plate member are simultaneously cut out from the common base material, so that the material is used without waste and the material cost It is possible to reduce it.

The present invention is not limited to the above-described embodiments, but can be variously modified within the scope of the present invention. For example, the joining member is not limited to the crank-shaped cross-sectional shape described above, but may be formed in the cross-sectional shape as shown in FIG. The joining member 20 illustrated in FIG. 6A includes one first facing portion 20a, and a pair of second facing portions 20b that are continuous on both sides of the first facing portion via the rising portions 20c.
It is equipped with. In addition, the joining member 20 shown in FIG. 6B includes the first and second opposing portions 20a and 20b which are continuous via the rising portion 20c, and the first and second opposing portions 20a and 20b.
Another rising portion 20c extending from the facing portion is integrally provided. Even when such a joining member 20 is used, it is possible to obtain the same effects as those of the above-described embodiment.

In the manufacturing process, the sealing material 22a,
22b may be filled in the front substrate 12 and the rear substrate 11 side instead of the joining member 20, or may be filled in both the joining member and the substrate. Furthermore, the sealing material may be filled through a suitable base. The method of cutting the thin plate member and the frame-shaped thin plate from the base material is not limited to etching, and another method may be used.

It is sufficient that the joining member has conductivity and its melting point or softening point is higher than that of the sealing material. The combination of the joining member and the sealing material is not limited to the iron-nickel alloy and indium, and may be necessary. Various selections can be made according to this. Further, the present invention is not limited to a flat panel display device that requires a vacuum envelope such as an FED or SED, but other flat panel display devices such as a PDP in which a discharge gas is injected after a vacuum is made. It is also effective for devices.

[0036]

As described above, according to the present invention, it is possible to provide a flat-panel display device which can be easily sealed in a vacuum atmosphere at low cost, and a manufacturing method thereof. You can

[Brief description of drawings]

FIG. 1 is a perspective view showing a flat-panel display device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the flat display device taken along line AA of FIG.

FIG. 3 is a plan view showing the base material processing of the joining member and the thin plate member in the flat display device.

FIG. 4 is a cross-sectional view showing press working of the joining member.

FIG. 5 is a perspective view showing a press-bonded joining member.

FIG. 6 is a perspective view showing a modification of each of the joining members.

[Explanation of symbols]

11 ... Rear substrate 12 ... Front substrate 13 ... Sealing part 14 ... Spacer 15a, 15b ... Sealing layer 16 ... Phosphor screen 17 ... Metal back layer 18 ... Vacuum envelope 20 ... Joining member 20a ... 1st facing part 20b ... Second opposing portion 20c ... Startup section 22a, 22b ... sealing material, 24 ... Electron emitting device 26 ... Thin plate member

Continued front page    (72) Inventor Takashi Enomoto             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 AA05 BC03                 5C032 AA01 BB16 BB18                 5C036 EE14 EF01 EF06 EG02 EG05                       EG06 EG15 EH05 EH11

Claims (10)

[Claims] 1. An envelope having a front substrate and a rear substrate that are arranged to face each other, and a sealing portion that seals the peripheral portions of the front substrate and the rear substrate to each other, the sealing portion comprising: A frame-shaped joining member that is press-formed from a seamless frame-shaped thin plate, and a sealing material that seals between the front substrate and the back substrate and the joining member, and the joining member is conductive. And a melting point or softening point higher than that of the sealing material. 2. The joining member faces the front substrate and the back substrate substantially in parallel, and has first and second facing portions sealed by the sealing material, the front substrate and 2. The flat-panel display device according to claim 1, further comprising a rising portion that integrally extends between the first and second facing portions along a direction intersecting with the facing substrate. 3. The flat panel display device according to claim 1, wherein a gap between the front substrate and the rear substrate is 1 mm or more. 4. The joining member is press-formed from a thin plate having a thickness of less than 1 mm, and has a height of 1 mm or more in a direction perpendicular to the front substrate and the rear substrate. 4. The flat panel display device according to any one of items 1 to 3. 5. A thin plate member is provided in the envelope so as to face the front substrate and the rear substrate, and the thin plate member comprises:
The flat panel display device according to claim 1, wherein the flat panel display device has an outer dimension smaller than an inner dimension of the joining member. 6. The joint member according to claim 1, wherein the joint member integrally has a plurality of projecting portions projecting outward from the sealing portion and forming current-carrying terminals. The flat-panel display device described. 7. The flat-panel display device according to claim 6, wherein the protrusions protrude from four corners of the joining member, respectively. 8. A phosphor screen formed on the inner surface of the front substrate, a plurality of electron sources provided on the back substrate for emitting electron beams toward the phosphor screen, and the front substrate. 8. The flat mold according to claim 1, further comprising a plurality of spacers provided between the back substrate and the front substrate and maintaining a distance between the front substrate and the back substrate. Display device. 9. A method of manufacturing a flat-panel display device, comprising 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. In, a seamless frame-shaped thin plate having conductivity and a melting point or softening point higher than that of the sealing material is prepared, and the frame-shaped joining member is press-formed from the frame-shaped thin plate. And filling a sealing material between the front substrate and the rear substrate and the bonding member, and aligning the front substrate, the rear substrate and the bonding member filled with the sealing material at predetermined positions. The bonding member and the sealing material are heated in the vacuum atmosphere by heating the bonding member and the sealing material, and after the sealing material is melted, the energization is stopped to cool the sealing material. And above the front substrate and back substrate Method of manufacturing a flat-panel display is characterized in that to seal the joint member. 10. The frame-shaped thin plate for molding the joining member and the rectangular thin-plate member located inside the first thin plate are simultaneously cut out from the base metal thin plate, and the cut-out is performed. The joining member is formed by pressing from a frame-shaped thin plate, and then the joining member is sealed in a state where the cut-out thin plate member is arranged between the front substrate and the back substrate. The method for manufacturing the flat panel display device according to claim 9.