JPH0511381B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a gas discharge display panel having a large number of cathodes provided with an emitter layer and a method for manufacturing the same, and in particular, to improve a method for forming an emitter layer. The present invention relates to a gas discharge display panel that provides a fine and bright display, has a low driving voltage, and has a long life, and a method for manufacturing the same.

[Prior Art] Conventionally, in the case of gas discharge display panels of this type, a plurality of cathodes are formed on a back substrate made of an insulating material such as flat glass, and barrier ribs for separation are provided between the cathodes. Further, an anode is arranged to face the cathode with a discharge gap in between, and a front substrate is arranged to face the back substrate, and the peripheral edges of both substrates are sealed to form an airtight envelope. Both of the electrodes are sealed together with a discharge gas in the airtight envelope to form a discharge cell at the opposing portion of the electrodes.

When manufacturing the above gas discharge display panel,
A metal foil made of Fe, Ni, Cr, or an alloy thereof is etched to form a cathode in a predetermined pattern, and an emitter layer is formed by plasma spraying an emitter material on the surface of the cathode. Alternatively, a metal paste such as Ni, Ag, Pd, etc. is printed in a predetermined pattern on the back substrate, and an emitter material is printed on the surface, and the metal is attached in a predetermined pattern. Low-melting glass is printed between the pastes, and this is used to form the cathode, emitter layer, and barrier ribs.

[Problems to be Solved by the Invention] However, in the above method of forming the cathode and emitter layers by etching and plasma spraying, the emitter material is sufficiently melted by the high temperature plasma to form a strong emitter layer. Although high spatter resistance can be obtained due to the formation of a layer, the metal foil is deformed by pretreatment such as blasting and plasma spraying, making it extremely difficult to form a cathode with a fine pattern. For example, in the case of a pattern in which a large number of ribbon-shaped cathodes are arranged in parallel for a character display, the lower limit of the cathode pitch is 0.8 mm, and there is a problem that a fine display cannot be obtained.

On the other hand, with the printing method, there is a risk that the gas discharge display panel, which has a flat structure, may undergo structural deformation due to high temperatures and cannot be processed at high firing temperatures. This results in insufficient bonding and poor spatter resistance against ion bombardment. Furthermore, in this method, there is a risk that the printed pattern may be misaligned, and if the cathode is not completely covered with the emitter layer, there is a problem that the spatter resistance is further reduced and the service life is shortened.

Furthermore, when the cathode is operated as a hollow cathode, the discharge sustaining voltage is lowered and the amount of negative glow light emitted is increased, and a gas discharge display panel with high brightness display can be obtained with a low driving voltage. Since the emitter layer formed by the above-described method has a flat structure, it cannot operate as a hollow cathode, and the driving voltage is higher and the display brightness is lower than in the case of a hollow cathode.

The present invention was devised in view of the above points, and
It is an object of the present invention to solve the above-mentioned problems at once, and to realize a gas discharge display panel and a method for manufacturing the same, which can provide a fine, high-luminance display, have a low driving voltage, and have a long life.

[Means for Solving the Problem] In order to achieve the above-mentioned object, the gas discharge display panel of the present invention includes a plurality of printed cathodes formed on an insulating substrate, and a printed cathode having a thickness thicker than the cathodes between the cathodes. It is characterized by providing an insulating barrier rib, and further forming an emitter layer on the side surfaces of the cathode display and barrier rib, and its manufacturing method includes printing a conductive material on an insulating substrate, providing a plurality of cathodes, and , after forming barrier ribs made of an insulating material between the cathodes to be thicker than the cathodes,
A high-melting-point emitter material is applied in a molten state to the surfaces of the cathode and barrier ribs by plasma spraying, and then the emitter material attached to the top of the barrier ribs is removed to insulate the emitter material in a manner corresponding to the cathode. The method is characterized in that an emitter layer is formed separately on the cathode surface and the barrier rib side surface.

[Function] Since the present invention has the above-described configuration, a fine cathode pattern can be obtained by printing, and the emitter material is completely melted by the high temperature of several thousand to tens of thousands of degrees within the plasma jet. , a strongly sintered emitter layer is formed without exposing the panel itself to high temperatures. Moreover, since the formed emitter layer has a substantially U-shaped cross section, the two negative glows formed on the opposing surfaces are combined and operate as a hollow cathode.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is a sectional view showing the manufacturing process of the present invention. In the figure, reference numeral 1 is an insulating substrate made of flat glass with a thickness of several mm, and as shown in FIG. After printing, a low melting point glass paste of lead borosilicate glass is printed between the parallel metal pastes, and this
Sintering is performed at a temperature of approximately .degree. C. to form a cathode 2 with a thickness of 20 to 30 .mu.m and a barrier rib 3 with a thickness of 350 to 400 .mu.m.

Next, as shown in FIG. 1B, an emitter material 4 mainly composed of LaB ₆ is sprayed onto the surfaces of the cathode 2 and barrier ribs 3 by plasma spraying, and is deposited in a melted state to a thickness of 100 to 150 μm. . The melting point of LaB ₆ is approximately 2,600°C, but it is completely melted and strongly sintered by the high temperature of several thousand to tens of thousands of degrees within the plasma jet.

Thereafter, as shown in FIG. 1C, the emitter material 4 adhering to the top of the barrier rib 3 is removed, the emitter material 4 is insulated and separated into a plurality of parts, and an emitter layer 5 corresponding to the cathode 2 is formed. The above emitter layer 5
are formed over the surface of the cathode 2 and the side surfaces of the two barrier ribs 3 adjacent to the cathode 2, and have a substantially U-shaped groove in cross section. In this case, if the depth of the groove is 150 μm or more, it can function as a hollow cathode. Methods for removing the emitter material 4 on the tops of the barrier ribs 3 described above include, for example, cutting off the tops of the barrier ribs 3 by cutting or scraping them off by polishing, as well as other appropriate methods. In short, any method is sufficient as long as the emitter material 4 can be completely insulated and isolated as the emitter layer 5 corresponding to the cathode 2.

The emitter material 4 has characteristics such as a small work function, little wear due to ion collisions, and _{a high} melting point. ₆ , _CeB6 ,
GdB ₆ , etc.), rare earth element tetraborides (YB ₄ ,
GdB ₄ , etc.), rare earth element oxides (Y ₂ O ₃ , La ₂ O ₃ ,
CeO ₂ , Gd ₂ O ₃ , etc.), oxides of alkaline earth metal elements (MgO, SrO, etc.), complex compounds of oxides of alkaline earth metal elements and molybdates of the elements,
Complex compounds of oxides of alkaline earth metal elements and tungstates of the elements, complex compounds of oxides of alkaline earth metal elements and aluminates of the elements (aMgO・bAl ₂ O ₃ , aBaO, bSrO・cAl ₂ O ₃ etc.)
etc. can be suitably used.

Among the above Emitsuta materials, oxides of alkaline earth metal elements, composite compounds of oxides of alkaline earth metal elements and molybdates of the elements, oxides of alkaline earth metal elements and tungstates of the elements and a complex compound of an oxide of an alkaline earth metal element and an aluminate of the element,
They are obtained by thermally decomposing carbonates of alkaline earth metal elements, molybdates of alkaline earth metal elements, tungstates of alkaline earth metal elements, and aluminates of alkaline earth metal elements, respectively. It is insulating. Oxides of rare earth elements are also insulating. Borides of rare earth elements are electrically conductive.

In the present invention, since the emitter material is formed as a conductive emitter layer, the conductive material is used as is, and the insulating material is mixed with the conductive material. For example, rare earth element hexaborides or rare earth element tetraborides may be used alone or as a mixture, or rare earth element oxides may be used alone or as mixtures, alkaline earth metal oxides, or alkaline earth metals. A composite compound of an oxide of an element and a molybdate of the element, a composite compound of an oxide of an alkaline earth metal element and a tungstate of the element, or an oxide of an alkaline earth metal element and an aluminate of the element Single or mixture of complex compounds with salts, single or mixtures of oxides of rare earth elements, oxides of alkaline earth metal elements, and complex compounds of oxides of alkaline earth metal elements and molybdates of the elements. , mixed with a single substance or a mixture of a composite compound of an oxide of an alkaline earth metal element and a tungstate of the element, or a composite compound of an oxide of an alkaline earth metal element and an aluminate of the element. use.

As shown in FIG. 2, the insulating substrate 1 is used as a back substrate, and the anode 7 is disposed orthogonally on the cathode 2 via a back spacer 6 having a through hole 6a, so that the electrodes 2 and 6 are opposed to each other. A discharge cell 8 is formed in the portion, and a front spacer 9 having a through hole 9a is further provided thereon.
A front surface 10 made of flat glass is placed through the
By sealing the peripheral edges of the rear substrate 1 and the front substrate 10 to form an airtight container 11, and filling the container with a discharge gas mainly composed of a rare gas, a gas discharge display panel 12 for displaying characters can be formed. It is formed.

The present invention can be applied to various gas discharge display panels, including the above-mentioned gas discharge display panel for character display, as well as bar graph type panels in which strip-shaped electrodes are arranged in parallel.

[Effects of the Invention] As detailed above, according to the present invention, a fine cathode pattern is formed by printing, so a fine-grained, high-quality display can be obtained, and a high-melting point material is obtained by plasma spraying. Since the emitter material is completely melted and sintered as a strong emitter layer, the drive voltage is lower and the life is longer. Moreover, since the cross-sectional shape of the formed emitter layer is approximately U-shaped, it operates as a hollow cathode, and a bright display can be obtained due to the hollow cathode effect.
Coupled with the voltage reduction due to the emitter effect, the drive voltage can be further reduced.

[Brief explanation of the drawing]

The figures show one embodiment of the present invention, and FIGS. 1A to C
is a cross-sectional view of main parts for explaining the manufacturing process, the second
The figure is a cutaway exploded perspective view. DESCRIPTION OF SYMBOLS 1... Insulating substrate, 2... Cathode, 3... Barrier rib, 4... Emitter material, 5... Emitter layer.

Claims (1)

[Scope of Claims] 1. A plurality of cathodes are provided by printing a conductive material on an insulating substrate, and barrier ribs made of an insulating material are formed between the cathodes to be thicker than the cathodes, and then the cathodes and barrier ribs are formed between the cathodes. By applying a high melting point emitter material to the surface in a molten state by plasma spraying and then removing the emitter material attached to the top of the barrier rib, the emitter material is insulated and separated in correspondence with the cathode. A method for manufacturing a gas discharge display panel, comprising forming an emitter layer on a cathode surface and a barrier rib side surface. 2. The method of manufacturing a gas discharge display panel according to claim 1, wherein the emitter material attached to the top of the barrier rib is removed by cutting the top of the barrier rib. 3. The method of manufacturing a gas discharge display panel according to claim 1, wherein the emitter material attached to the top of the barrier rib is removed by polishing. 4. A plurality of printed cathodes are formed on an insulating substrate, and insulating barrier ribs thicker than the thickness of the cathodes are provided between the cathodes, and an emitter layer is further formed on the surface of the cathode and the side surface of the barrier rib. gas discharge display panel. 5. The gas discharge display panel according to claim 2, wherein the emitter layer is made of a rare earth element hexaboride or a rare earth element tetraboride alone or in a mixture. 6 Claim 2, characterized in that the emitter layer is made of a mixture of a rare earth element hexaboride or a rare earth element tetraboride alone or a mixture, and a rare earth element oxide or a mixture thereof. Gas discharge display panel described in. 7. The emitter layer contains a rare earth element hexaboride or a rare earth element tetraboride alone or in a mixture, an oxide of an alkaline earth metal element, an oxide of an alkaline earth metal element, and a molybdate of the element. From a complex compound, a complex compound of an oxide of an alkaline earth metal element and a tungstate of the element, or a complex compound of an oxide of an alkaline earth metal element and an aluminate of the element, either alone or as a mixture. A gas discharge display panel according to claim 2, characterized in that the gas discharge display panel comprises: 8. The emitter layer contains a single substance or a mixture of rare earth element hexaboride or rare earth element tetraboride, a single substance or mixture of rare earth element oxides, an alkaline earth metal element oxide, or an alkaline earth metal element oxide. A composite compound of an oxide and a molybdate of the element, a composite compound of an oxide of an alkaline earth metal element and a tungstate of the element, or an oxide of an alkaline earth metal element and an aluminate of the element. 3. The gas discharge display panel according to claim 2, wherein the gas discharge display panel is made of a single compound compound or a mixture thereof.