KR20010089028A - Vacuum fluorescent display having getter and manufacturing method of the getter - Google Patents

Abstract

PURPOSE: A vacuum fluorescent display tube with getter and method for manufacturing getter is provided to minimize the height of the getter, while preventing breakage of vacuum container during a getter flashing process. CONSTITUTION: A vacuum fluorescent display tube comprises upper and lower substrates(2,4) which are frit-bonded into a single unit constituting a vacuum container; a cathode(10) formed, as a cold electron emission element, at the inner surface of the lower substrate; an anode(20) arranged at the inner surface of the upper substrate opposed to the cathode, and which has a fluorescent layer; and a getter unit(30) arranged at the surface of the lower substrate at the outer periphery of the cathode. The getter unit includes a getter container having a bottom portion formed at the surface of the lower substrate and a getter film diffusion prevention portion formed into a predetermined height from the circumference of the bottom portion; and a getter material(32) deposited in the getter container.

Description

Fluorescent display tube with getter and manufacturing method of this getter {Vacuum fluorescent display having getter and manufacturing method of the getter}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluorescent display tube, and more particularly, to minimize the height of the formation to be suitable for a surface-cathode fluorescent display tube, and to prevent the display pattern of the getter layer from being clogged without causing the vacuum container to break during the getter flashing process. And a method for producing the getter.

In general, a fluorescent fluorescent display (VFD) is a self-luminous display device that selectively emits electrons emitted from the cathode by colliding with a fluorescent layer formed on the anode, and is excellent in visibility, wide viewing angle, and can be driven at low voltage. Because of its high reliability, it is used for various purposes in various fields.

FIG. 8 is an exploded perspective view of a fluorescent display tube according to the prior art, and FIG. 9 is an enlarged view of FIG. 8, in which the fluorescent display tube, along with the side glass 1, is formed of the upper substrate 3 and the lower substrate constituting the vacuum container. (5), a filament (7) for emitting hot electrons when voltage is applied, an anode electrode (13) electrically connected to the wiring layer (9) and forming a fluorescent layer (11) on the surface, and the filament (7) A metal mesh-type grid 15 located between the anode electrodes 13 and a getter 17 for adsorption of residual gas in the tube is provided.

According to the above configuration, when voltage is applied to the filament 7 and the anode electrode 13 and the grid 15 through the lead wire 19, the hot electrons are emitted from the filament 7, the emitted electrons are grid ( 15 is accelerated and diffused to impinge on the fluorescent layer 11 formed on the anode electrode 13 to emit the fluorescent layer 11, the emitted light is transmitted to the user through the front substrate (3).

Since the fluorescent display tube driven on the same principle must maintain a high vacuum inside for smooth electron movement, the getter 17 is provided to increase the degree of vacuum by adsorbing the gas remaining in the tube after the exhaust process.

The getter 17 is welded to the getter support 23 formed integrally with the filament support 21 to the getter acceptor 27 having the getter filler 25, such as barium, to be integrally attached to the tube and the getter after the exhaust process. In the course of flashing, the getter material is scattered and reacts with the residual gas in the tube to form a getter film to adsorb the residual gas.

However, in the getter flashing process by the high frequency induction heating, the induction heat causes thermal expansion of each component and the vacuum vessel, and cracks may occur in the upper substrate 3 or the lower substrate 5 due to the difference in thermal expansion coefficient between the metal components and the vacuum vessel. In addition to the problem that the side glass 1 is broken, and the getter acceptor 27 is not provided high enough, a getter film formed by bonding with the residual gas may cause a defect such as covering the display pattern.

On the other hand, instead of the filament 7 which emits hot electrons as a cathode, a surface cathode (face cathode) type fluorescent display tube which emits cold electrons by using the field emission effect has been devised. The surface-cathode fluorescent display tube is provided with a stripe pattern cathode and R, G, and B fluorescent films so as to vertically cross each other on the upper and lower substrates to form a dot matrix, and is configured to control electron emission by partitions and grids. .

Such a surface-cathode fluorescent display tube has the advantage of solving the problem of reducing the display area by the filament support when using the filament as the cathode, reducing the influence of heat of each part by emitting electrons at low temperature, and simplifying the assembly process. .

However, the surface-cathode fluorescent display tube has a very small gap between the front substrate and the rear substrate, so that the getter used for the general fluorescent display tube cannot be assembled. As a result, a method of mounting a getter material-embedded tube on one of the substrates has been devised, but in this case, the manufacturing process of the substrate is complicated, and the smooth appearance of the fluorescent display tube is hindered, resulting in damage to the tube during assembly or attachment of the product. Since it is easy, there was a problem of causing a defect of the fluorescent display tube.

Accordingly, the present invention has been devised to solve the above problems, and an object of the present invention is to minimize the height of the formation to be suitable for a surface-cathode fluorescent display tube and to display the getter film while preventing cracking of the vacuum container which may occur during the getter flashing process. The present invention provides a getter capable of preventing pattern obstruction and a method of manufacturing the getter.

1 is an exploded perspective view of a fluorescent display tube according to the present invention;

2 is a perspective view of a cathode;

3 is a perspective view of a cathode according to another embodiment;

4 is a sectional view of a fluorescent display tube according to the present invention;

5 to 7 are schematic views showing the manufacturing process of the getter according to the present invention.

8 is an exploded perspective view of a fluorescent display tube according to the prior art;

9 is an enlarged view of a portion A of FIG. 8;

In order to achieve the above object, the present invention,

Upper and lower substrates integrally bonded by frit to form a vacuum container,

A cathode formed on an inner surface of the lower substrate and emitting cold electrons;

An anode formed in a predetermined pattern on an inner surface of the upper substrate facing the cathode and having a fluorescent layer;

Provided is a fluorescent display tube including gettering means provided on a lower substrate surface outside the cathode.

The gettering means comprises a getter acceptor for accommodating the getter filler and a getter filler applied to the inside of the getter acceptor, wherein the getter acceptor is formed by screen printing on a lower substrate and forms a getter film diffusion preventing end of a predetermined height. .

As a result, the present invention can effectively improve the vacuum degree of the surface cathode fluorescent display tube by providing gettering means for stably acquiring the getter packing material and minimizing the formation height.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view of a fluorescent display tube according to the present embodiment, wherein the fluorescent display tube is formed on the inner surface of the pair of upper and lower substrates 2 and 4 and the lower substrate 4 constituting a vacuum container. A cathode 10 having an electron emission, an anode 20 formed in a predetermined pattern on the inner surface of the upper substrate 2 facing the cathode 10, and a lower substrate surface outside the display pattern. Turreting means (hereinafter referred to as 'getters') 30.

As shown in FIG. 2, the cathode 10 is disposed between the cathode electrode 12, which is formed in a stripe pattern on the surface of the lower substrate 4, and the cathode electrode 12. The lower partition 14 which insulates, and the cathode wiring layer 16 connected to each cathode electrode 12 are comprised.

As shown in FIG. 3, the anode 20 is formed between the anode electrode 22 and the anode electrode 22 formed in a stripe pattern so as to vertically intersect the cathode electrode 12 on the surface of the upper substrate 2. A top partition wall 24 arranged to insulate each anode electrode 22, R, G, and B fluorescent films 26 applied to the surface of the anode electrode 12, and connected to each anode electrode 22, respectively. The anode wiring layer 28 is formed.

Thus, when a predetermined voltage is applied to each of the cathode electrode 12 and the anode electrode 22 through the cathode wiring layer 16 and the anode wiring layer 28, the voltage applied to the cathode electrode 12 and the anode electrode 22 is applied. As the electric field is concentrated on the cathode electrode 12 by the difference, cold electrons are emitted by the tunneling effect, and the emitted electrons collide with the fluorescent film 26 formed on the anode electrode 22 and emit light by the fluorescent film 26. Will implement the screen.

In addition, in the case of the triode structure, a grid electrode 18 surrounding the cathode electrode 12 is attached between the cathode 10 and the anode 20 to emit electrons from the cathode electrode 12 together with the anode electrode 22. To control.

As such, the cathode electrode 12 that emits cold electrons by forming an electric field is formed of a material having a high melting point, a low work function, and a low vapor pressure in a vacuum state to withstand a high electron emission amount. The cathode electrode 12 is mainly composed of refractory metals such as silicon (Si), tungsten (S), molybdenum (Mo), niobium (Nb), tantalum (Ta), aluminum (Al), or diamond, diamond carbon (Diamond-Liked Carbon) or graphite.

The surface-cathode fluorescent display tube driven according to this principle includes a getter 30 to reduce the gas remaining in the tube after the exhaust process. The getter 30 according to the present embodiment has a lower portion outside the cathode 10. It is formed at the minimum height at the surface of the substrate 2.

4 is a cross-sectional view of the fluorescent display tube according to the present embodiment, wherein the getter 30 includes a getter container 34 for accommodating the getter filler 32 and a getter filler 32 coated inside the getter container 34. )

The getter filler 32, for example, has a nickel-aluminum-barium alloy powder as a main component, and is heated in a getter flashing process to remove residual gas in the tube while reacting with the residual gas in the tube while forming a getter film.

The getter container 34 includes a bottom portion 34a to which the getter filler 32 is applied, and a getter film diffusion preventing end 34b formed at a predetermined height around the bottom portion 34a. The getter film diffusion preventing end 34b is formed so as to be close to the upper substrate 2 only at a minimum interval at which barium evaporated from the getter filler 32 can react with the residual gas in the tube.

The getter acceptor 34 is made of a kind of glass containing silicon as a main component so as to have a coefficient of thermal expansion similar to that of the upper and lower substrates 2 and 4, and the specific shape thereof is as shown in FIG. It may be formed in a rectangle on the surface of the lower substrate (4).

According to the above configuration, when the upper and lower substrates 2 and 4 are integrally bonded and the inside thereof is evacuated, and the getter 30 is heated in a high frequency induction manner, nickel and aluminum in the getter filler 32 are released. As the alloy is formed, heat is released to reach the flash temperature quickly, and the barium evaporated by this heat adsorbs with the residual gas in the tube to form a getter film, thereby maintaining the inside of the tube at a high vacuum.

At this time, the getter film diffusion preventing end 34b of the getter acceptor 34 prevents the barium from excessively flowing into the pattern region, thereby preventing the getter film from intruding into the display pattern region.

In addition, since the getter acceptor 34 has a coefficient of thermal expansion similar to that of the upper substrate 2 and the lower substrate 4, the difference in thermal expansion coefficient between components constituting the fluorescent display tube during the getter flashing process and the cooling to room temperature. Cracking or cracking of the upper and lower substrates may be prevented.

As a result, the getter 30 according to the present embodiment is particularly suitable for a surface-cathode fluorescent display tube having a very small gap between the upper and lower substrates 2 and 4, and the occurrence of defects in the fluorescent display tube and the getter film during the manufacturing process. It has an advantage of minimizing display pattern intrusion.

Next, a getter manufacturing method of the fluorescent display tube according to the present embodiment will be described with reference to FIGS.

In order to manufacture the getter, first, a lower substrate 4 on which the cathode 10 is formed is prepared, and the first screen mesh 40 is mounted on the lower substrate 4 outside the cathode 10, and then the first screen mesh 40 is mounted. The getter receptor paste 36 is applied onto the screen mesh 40.

The getter acceptor paste 36 contains SiO ₂ , PbO and B ₂ O ₃ , which are powder glass as a main component, and includes an organic binder for improving adhesion to a substrate and a solvent that provides easy viscosity to a printing operation. A vehicle or the like is mixed.

The getter acceptor paste 36 is compressed using the squeeze 42 to print the getter acceptor paste 36 on the lower substrate 4. (See Figure 5)

In this case, the first screen mesh 40 has a structure in which all portions except the bottom portion are formed to be blocked by the photosensitive resin film 44, and the patterning process of the photosensitive resin film 44 is well-known photolithography. It can be done in a process.

Next, mount the patterned second screen mesh 46 so that only the periphery of the bottom is opened, apply the getter acceptor paste 36, and then reach the set height using the squeeze 42. Repeat until printed. (See Figure 6)

After the getter acceptor paste 36 is printed in this manner, the printed getter acceptor paste 36 is heated to remove the solvent in the paste, and then put into a calcination furnace to remove organic substances in the paste, thereby obtaining a final getter acceptor ( Complete with 34).

Finally, the third screen mesh 48 is mounted on the lower substrate 4, and the getter filler paste 38 is printed on the bottom portion 34a of the getter container 34 in a predetermined thickness. Here, the getter filler paste 38 is formed by mixing nickel powder, barium-aluminum alloy powder, a binder, and the like. (See Figure 7)

After the getter 30 is manufactured by the above process, the upper and lower substrates 2 and 4 are integrally bonded together with the frit 50, and the inside of the tube is evacuated by evacuation and remaining in the tube through a getter flashing process. Removing the gas completes the manufacture of the fluorescent display tube.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

As described above, the fluorescent display tube according to the present invention forms the getter acceptor and the getter filler directly on the lower substrate by screen printing to stably receive the getter filler while minimizing the formation height. Particularly suitable for display tubes.

In the getter flashing process, the getter film diffusion prevention step of the getter receptor prevents the getter film from infiltrating into the display pattern and minimizes the difference in thermal expansion coefficient between the getter receptor and the upper and lower substrates to prevent cracking or cracking of the vacuum container. Can be effectively prevented.

Claims (10)

Upper and lower substrates integrally bonded by frit to form a vacuum container; A cathode formed on an inner surface of the lower substrate and emitting electrons; An anode formed on an inner surface of the upper substrate facing the cathode and having a fluorescent layer; And a gettering means provided on a surface of a lower substrate outside the cathode. The method of claim 1, The gettering means, A getter container comprising a bottom portion formed on the lower substrate surface, and a getter film diffusion preventing end formed at a predetermined height at the periphery of the bottom portion; Fluorescent display tube consisting of a getter filler applied to the inside of the getter receptor. The method of claim 2, A fluorescent display tube made of a substance in which the getter acceptor contains silicon. The method of claim 2, A fluorescent display tube made of a material containing the nickel-aluminum-barium alloy component. The method of claim 1, And a cathode in which the cathode is formed in a stripe pattern and connected to each of the wirings, and a partition wall disposed between the cathode electrodes to insulate each cathode electrode. The method of claim 1, And an anode electrode formed in a stripe pattern in which the anode crosses the cathode electrode vertically, and having a fluorescent film attached to a surface thereof, and a partition wall disposed between the anode electrodes to insulate each anode electrode. The method of claim 1, And a grid electrode disposed between the cathode and the anode. Screen-printing the getter acceptor paste outside the pattern region of the prepared lower substrate to form a bottom portion of the getter acceptor; Repeatedly printing a getter container paste at a periphery of the bottom part to form a getter film diffusion preventing end having a predetermined height; Firing the printed getter acceptor paste to remove organic material within the paste; A method of manufacturing a getter of a fluorescent display tube, the method comprising the step of screen printing a getter filler paste on the bottom of the getter receptor. The method of claim 8, The getter manufacturing method of the fluorescent display tube which the said getter acceptor paste consists of a mixture of powder glass, a solvent, and an organic binder. The method of claim 8, And the getter filler paste is a mixture of nickel powder, barium-aluminum alloy powder and a binder.