JP3217579B2 - Display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat panel display, and more particularly to a flat panel display device using a micro cathode array.

[0002]

2. Description of the Related Art A flat panel display using a field emission type cathode array of a micron order size as shown in FIG. 3 is conventionally known. As shown in FIG. 3, in this conventional flat panel display, a silicon dioxide (SiO ₂ ) film 22 having a cavity 22 a is formed on a silicon substrate 21. This Si in the portion around the cavity 22a
On the O ₂ film 22, molybdenum (Mo) or niobium (N
A gate electrode 23 made of b) or the like is formed, and a molybdenum cone-shaped cathode electrode 24 is formed on the Si substrate 21 inside the cavity 22a.

[0003] A fluorescent screen having a phosphor 26 formed on a flat glass plate 25 faces in parallel with the Si substrate 21 on which the cathode array composed of the large number of cathode electrodes 24 is formed. The space between the substrate and the Si substrate 21 is sealed with the vacuum kept. The flat panel display is evacuated during the manufacturing process and sealed in a state where the vacuum is maintained. However, when the flat panel display is actually used, the electron beam enters the phosphor screen and gas is released. This gas causes the degree of vacuum in the tube to deteriorate. Deterioration of the degree of vacuum caused ion bombardment in the tube, destroying the gate electrode and the cathode electrode, thereby making the operation of the display defective.

[0004]

The conventional flat panel display has a problem in that the gate electrode and the cathode electrode are destroyed by the gas generated when the electron beam enters the phosphor screen, resulting in a malfunction of the display. .

The present invention has been made in view of the above problems, and an object of the present invention is to provide a display device in which the reliability of display operation is improved without fear of destruction of a gate electrode or a cathode electrode due to gas generation. Aim.

[0006]

According to the present invention, there is provided a pixel display comprising a plurality of cathode electrodes formed on a substrate and a phosphor disposed opposite to the substrate and receiving an electron beam emitted from the cathode electrodes. A transparent substrate having a region formed on the surface thereof, a sealing member for bonding the substrate and the transparent substrate, and a substrate and the transparent substrate outside the pixel display portion and
And a getter member fixed to the sealing member in the middle of the plate and receiving an electron beam emitted from the cathode electrode. Further, a higher potential than the cathode electrode may be applied to the getter member.

In particular, it is desirable that the getter member is arranged at a position where the electron beam is irradiated by the video signal, since the getter member can be activated with high efficiency during use. Further, it is desirable that the getter member is made of tantalum, titanium, zirconium, niobium alone or an alloy thereof, from the viewpoint of extending the life.

Further, the surface of the getter member on which the electron beam is incident is made of a non-getter material such as nickel or stainless steel, and the opposite surface is made of a material having a getter function such as tantalum, titanium or zirconium. This is desirable in order to prevent re-emission of the gettered gas and increase getter efficiency without reducing getter capability.

The low-pressure region formed between the substrate and the transparent substrate is preferably a vacuum from the viewpoint of efficient electron emission from the cathode electrode, but is filled with a trace amount of gas, for example, an inert gas such as argon. May be available.

[0010]

According to the above-mentioned structure, the getter member is always irradiated with the electron beam during use of the display, and the active state is maintained by the heat, so that unnecessary gas generation can be prevented. Can be maintained in a favorable low-pressure state, and the life of the display device can be maintained for a long time.

[0011]

The present invention will be described below with reference to examples. (Embodiment 1) FIG. 1A is a sectional view showing a flat panel display type display device according to the present invention, and FIG. 1B is an enlarged view of the inside of the circle.

As shown in FIG. 1, in a flat panel display according to this embodiment, for example,
An insulating film 12 having a cavity 12a, such as a SiO ₂ film, is formed on a conductive flat silicon substrate 11 having a width of 150 mm, a width of 150 mm and a thickness of 1 mm. The insulating film 1 in a portion around the cavity 12a
2, a gate electrode 13 made of, for example, molybdenum is formed.

The Si inside the cavity 12a is
On the substrate 11, a cathode electrode 14 made of a microchip is formed. A cathode array is formed by the large number of cathode electrodes 14. In this embodiment, the cathode array is formed with Si
A fluorescent screen in which a phosphor 16 is formed on a glass plate 15 is provided so as to face the substrate 11. Here, a phosphor screen is used as a pixel display area made of a phosphor that receives an electron beam emitted from the cathode array. In the case of this embodiment, the fluorescent screen is 93 m long.
m, 121 mm in width. Further, a vacuum region is formed between the Si substrate 11 and the glass transparent substrate 15 as a low pressure region.

[0014] Further, outside the fluorescent screen, 1
A getter member 7 is attached, and receives a beam emitted from the cathode electrode 14 of the cathode electrode 14 which does not irradiate the phosphor screen with the electron beam. Here, the outside of the pixel display area refers to an area that is the outer periphery of the pixel display area when the display device is viewed from above the plane of FIG. 1A.

The getter member will be described in more detail. This getter member is made of a 7 μm thick zirconium plate, has a width of 5 mm and a length of 95 mm, and is attached to both sides of the fluorescent screen as described above. The width of the getter member 17 is set to be substantially the same as the width of the video signal not displayed on the screen.

The cathode array, the fluorescent screen unit, and the getter member 17 configured as described above constitute a low-pressure region between the substrate 11 and the transparent substrate 15 by using a vacuum sealing member shown in FIG. Complete the device.

Next, a method of manufacturing the flat panel display according to this embodiment configured as described above will be described. As shown in FIG. 1, first, an insulating film 12 such as a SiO ₂ film is formed on a Si substrate 11 by, for example, a thermal oxidation method, a CVD method, or a sputtering method. A metal film for forming a gate electrode such as molybdenum or niobium is formed by a beam evaporation method.

Next, a resist pattern (not shown) having a shape corresponding to the gate electrode 13 to be formed is formed on the metal film by lithography. Next, the gate electrode 13 is formed by etching the metal film by wet etching or dry etching using the resist pattern as a mask.

Thereafter, the insulating film 12 is etched by wet etching or dry etching using the resist pattern and the gate electrode 13 as a mask to form a cavity 12a.

Next, after removing the resist pattern, a release layer made of, for example, aluminum or nickel is formed on the gate electrode by performing electron beam evaporation from a direction inclined at a predetermined angle with respect to the substrate surface. Thereafter, for example, molybdenum is deposited as a material for forming a cathode from a direction perpendicular to the substrate surface by an electron beam evaporation method.
Thereby, the Si substrate 11 inside the cavity 12a is
A cathode 14 is formed thereon.

Next, the release layer together with the metal film formed thereon is removed by a lift-off method. Next, a method for manufacturing the getter member 17 will be described. A zirconium plate having a thickness of 7 μm is formed into a width of 5 mm and a length of 95 mm.
^The member is activated by performing a heat treatment at 1300 ° C. in a vacuum device having a degree of vacuum of ⁻⁵ Pa or less.

Next, the getter member 17 is attached to the vacuum sealing member 18 as shown in FIG. The getter member 17 is connected to a lead terminal (not shown) so that a voltage can be electrically applied from outside the display.

Thereafter, as shown in FIG. 1, the screen section 16 coated with the phosphor and the vacuum sealing member 18 are attached to the Si substrate 11, and the desired flat panel is formed by electrostatically bonding in a vacuum apparatus. Complete the display.

Next, an example of the operation of the flat panel display will be described. The video signal is supplied to the cathode electrode 14 and the gate electrode 13 formed in a simple matrix system.
Is input to With reference to the cathode electrode 14, a gate voltage of +100 V is applied when the luminance is the highest. For example, +400 V is applied to a transparent electrode (not shown) of ITO or the like to the fluorescent screen unit. The amount of electrons emitted from the cathode is modulated by the voltage of the gate electrode. The electrons are guided by the electric field of the phosphor screen and enter the phosphor screen to cause the phosphor to emit light.

Next, the operation of the getter will be described. +400 V is applied to the getter member 17. Therefore, the electrons emitted from the cathode electrode 14 always impact the getter member 17 with the energy of 400 eV in accordance with the amount of the video signal. Due to this electron impact, the getter member 17 becomes 200
~ 300 ° C. By setting the temperature, the getter material 17 is always kept in an activated state, and the degree of vacuum in the tube is always kept in a good state.

As described above, according to this embodiment, the getter is not always provided with the getter material 17 because the getter is always irradiated with the electron beam during use of the display and keeps being activated by the heat. Compared to display devices,
A good vacuum state can be maintained even during a long use time, and a stable operation of the display can be maintained for a long time.

Since the getter member is not of the flash type, there is no harm such as electric leakage between the electrodes. In order to solve this problem, a flash type getter is used in a cathode ray tube or the like. That is, a getter in which powder made of a barium alloy is packed in a ring of stainless steel or the like is heated by high-frequency heating, and barium metal is deposited on a tube wall to form an active getter surface. With such a method, the vacuum in the tube can be maintained for a long time, but in the case of a flat panel display, there is no place for attaching the flash type getter and no place for vapor deposition. Even if there are some places, such a getter agent is not preferable since it is made of a conductive substance and leaks between electrodes. In the present embodiment, by selecting a place where the getter member is attached to the outside of the pixel display area, a display of a completely new structure which can surely perform the getter function in the flat panel type display device has not been provided. An apparatus can be provided. (Embodiment 2) In the following embodiments, the same portions as those in Embodiment 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the first embodiment described above, the case where the getter member is made of a zirconium material has been described. However, in this embodiment, the getter member is made of tantalum, titanium, niobium alone or an alloy thereof (including a zirconium alloy). This is a difference from the first embodiment. The structure is similar to that shown in FIG. Also in this embodiment, the same effect as in the first embodiment can be expected, and further, there is an effect of extending the life. (Embodiment 3) In the above embodiments 1 and 2, the case where the getter member is made of a single material has been described.
As shown in FIG. 2, material nickel surface getter member is incident electron beam, are made of non-getter material 27 ₁ such as stainless steel, the surface on the opposite side with tantalum, titanium, a getter effect of zirconium When the structure as made of 27 _2, it can be expected even better effect.

The reason is that, when the getter member is made of a single material, even if the amount of gas adsorbed near the surface of the getter member is small even when the electron beam is incident, it is re-emitted. If you leave the side to be incident electron beam into a non-getter material as a countermeasure above problem is eliminated. The getter having such a configuration can be generally manufactured as a clad material, but can also be manufactured by a plating method or a sputtering method. Also in this embodiment, the first embodiment
Of course, the same effect as described above can be obtained.

[0029]

According to the present invention, there is no fear that the gate electrode or the cathode electrode is broken due to gas generation, and the reliability of the display operation can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention.

FIG. 2 is a sectional view of a third embodiment of the present invention.

FIG. 3 is a cross-sectional view of a conventional display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Si substrate 12 ... Insulating film 13 ... Gate electrode 14 ... Cathode 15 ... Glass substrate 16 ... Fluorescent substance 17 ... Getter member 18 ... Vacuum sealing member

Continuing from the front page (72) Inventor Shuichi Uchikoga 33 Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa Prefecture Inside the Toshiba Institute of Industrial Science (72) Inventor Haruhiko Okumura 33, Shinisogo-cho, Isogo-ku, Yokohama-shi, Kanagawa (56) References JP-A-7-29520 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) H01J 31/12

Claims (3)

(57) [Claims] 1. A plurality of cathode electrodes formed on a substrate, a transparent substrate having a is arranged to face the substrate pixel display region comprising a phosphor that receives the emitted electron beam from the cathode electrode is formed on the surface A sealing member for bonding between the substrate and the transparent substrate; and a sealing member outside the pixel display portion and the substrate and the transparent substrate.
A getter member fixedly attached to the sealing member in the middle and receiving an electron beam emitted from the cathode electrode. 2. The display device according to claim 1, wherein the getter member comprises a non-getter material disposed on the cathode electrode side and a getter material disposed on the transparent substrate side. 3. The device according to claim 1, wherein a higher potential than the cathode electrode is applied to the getter member.
The display device according to the above.