JPH03201345A - Lamination type cathode device - Google Patents

Abstract

PURPOSE:To improve an electron radiation characteristic by forming an electron radiation substance layer on substrate metal via a metal powder sintered layer. CONSTITUTION:Metal powder sintered layer is wrappedly formed on substrate metal 10 wrappedly formed on one surface of a heat-resistant insulation substrate 1, an electron radiation substance layer 4 is formed on the metal powder sintered layer 11, and also a heater is formed on the other surface of the substrate 1. The application of voltage to a heating body 51 causes the heating body 51 to be heat-generated by Joule heat, the substrate metal 10 and the metal powder sintered layer 11 to be heated, and barium oxide, which is a component of the electron radiation substance layer 4, and silicon, a trace amount of which is contained in the metal powder sintered layer 11, to react. Ba produced by the reaction is made as a donor to conduct electron radiation. This improves an electron radiation characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an Mjl-shaped cathode device with improved electron emission characteristics used in an in-line color cathode ray tube.

(Prior Art) Figures 8 to 5 are enlarged views of conventional cathode devices of this type. Substrate 2 is heat resistant M
K A base metal in which tungsten is deposited on one surface of the substrate l by a method such as sputtering and arranged in a straight line, and 3 is integrally deposited on the heat-resistant insulating substrate 1 in the same manner as the base metal 2. A lead wire 4 with a cathode terminal 31 formed at the tip thereof is made of an alkaline earth metal oxide such as (Ba, 8r, Oa), etc., which is deposited on the eight base metals 2 by a method such as spraying. 51 is a heating element formed by sputtering a thin tungsten film on the other side of the heat-resistant insulating substrate 1 at a portion opposite to the base color M2, and then forming a meandering shape by photolithography. A conductive wire that is molded integrally with the heating element 51 and connects the heating element 51 in series, a wire is a heater terminal that constitutes the heater 5 together with the heating element 51 and the conductor 4152, 6 is a cathode container made of steatite, and 7 is a cathode. The cathode bin erected in the container 'a6, 8 a heater bin erected in the cathode container 6, and 9 a conductive wire connecting the cathode terminal 31 and the cathode bin 7 and the heater terminal portion and the heater bin 8.

In this conventional device, when a voltage is applied across the heater bin 8, a current flows through the heating element 51, and Joule heat is generated by the square of the current, the electrical resistance of the heating element 51, and time, as shown in the equation below. Occurs in a fixed amount.

Q ” I'xRXt Here, Q is the amount of heat, l is the current, R is the resistance, and t is the time.

This generated heat heats the three base metals 2 through the heat-resistant insulating substrate 1 by thermal conduction and thermal radiation. Base gold Ps
When 2 is heated to an operating temperature of about 8,000 °C, BaO, which is a component of the electron emitting material 4, undergoes a reduction reaction with W, which is the base metal 2, to generate free Ba. This free Da becomes a donor and an electron beam is emitted from the electron emitting material 4,
Lights up the 8-color fluorescent surface of a color cathode ray tube.

In this laminated cathode device, a life test was conducted with the base metal 2σ] operating temperature at 800°C and the current density emitted from the layer of electron emitting material 4 at 0.5^/crd.
The life time was only 4,000 hours. Note that the life time is defined as the time required for deterioration to reach 0)50% of the initial value. One reason for this short life is that barium tungstate, which is a reduction reaction product of BaO, is generated on the base metal 2, making it difficult for the reduction reaction between the electron emitting material 4 and the base metal 2 to occur. However, since the base metal 2 is made of a thin film, it is very thin and is quickly consumed by the reduction reaction. In order to improve this, there is a method of thickly depositing W, which is the base metal 2, by long-term sputtering, but there are practical problems due to heritage or manufacturing cost constraints.

[Problem to be solved by the invention]

Since the conventional laminated cathode device is constructed as described above, the electron emission characteristics begin to deteriorate early, which poses a practical problem.

The present invention was made to solve these problems, and it is an object of the present invention to provide an improved laminated cathode device with the purpose of improving electron emission characteristics.

[Means to solve the problem]

[σ] The laminated cathode device according to the present invention includes a sintered wire mesh powder deposited on a base metal deposited on one surface of a heat-resistant insulating substrate, and an electron emissive material layer on the sintered metal powder layer. In addition, a heater is formed on the other surface of the heat-resistant insulating substrate.

[Effect]

In this invention, since a sintered layer of metal powder is provided under the electron emitting material, a thick sintered metal layer can be formed relatively easily, and as a result, the electron emission characteristics can be maintained for a long period of time. It becomes possible to obtain a laminated cathode device.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

That is, in the yg1 diagram, O is deposited on the heat-resistant insulating substrate 1 to a thickness of 8 microns by sputtering, and then etched into a predetermined shape by photolithography to a diameter of 2fi.
The metal substrate 11 is made of nickel powder with an average particle size of 10 microns, and a metal powder containing fine silicon and magnesium is formed by screen printing or spraying to a thickness of about 100 microns. The nickel powder is deposited on the substrate gold@10 and heat-treated for 10 minutes at 10000C in hydrogen or vacuum air to sinter the nickel powder and the nickel thin film that is the base metal io. It is a metal powder sintered layer with high adhesion and mechanical fineness.

Note that the other configurations are the same as those of the conventional device shown in FIGS. 8 to 5, and therefore the description thereof will be omitted.

Here, the electron emitting material 4 is coated on the metal powder sintered layer 11 to a thickness of 60 to 100 microns by spraying or brush painting. Further, the heating element 51 is formed to have a film thickness of 8 microns and a width of 0.2 fl.

With this configuration, when a voltage is applied to the heating element 51, the heating element 51 generates heat due to Joule heat, as in the conventional case. Metal powder sintered layer 1
1 is heated.

When the metal powder sintered layer 11 is heated to a high temperature of approximately 8,000 °C, the metal powder sintered layer 11 is heated to a high temperature of approximately 8,000 °C, and the sintered metal powder layer 11 is heated to a high temperature of about 8,000 ℃. cause a similar reaction.

4 BaO+ 81 = 2Ba 10B & 1810m2
BaO-1-81=zBa+8 Soil OI Ba generated in these reactions serves as a donor, and electron emission is performed. Since the metal powder sintered layer 11 with a thick @ structure is provided on the base metal 10, the metal powder sintered layer 1 is formed by a reduction reaction.
There was no wear and tear, and the life characteristics could be significantly improved.

Figure 2 shows the life test characteristics, and the life test conditions were: cathode temperature 8000, extraction current 0, 5 A/crd.
And so. As a result, in the conventional model, it took 4,000 hours for the electron emission characteristics to deteriorate to 50% of the initial value, but in this example, it had a long life of 12,000 hours. In addition, this example can be easily sintered into a thick film of metal powder by screen printing method) id 1
Since it is possible to obtain 1, it has a high welfare value.

Although the gold base metal 10 is made of a thin film of Ninkel, it may be made of other metals such as titanium.

〔Effect of the invention〕

As mentioned above, the laminated cathode fabrication according to the present invention can be performed using
Since the electron emitting material is disposed on the K metal through the metal powder sintered layer, the electron emitting properties are the same as above and the productivity is excellent.

[Brief explanation of drawings]

1 and 2 are diagrams showing an embodiment of the present invention, in which FIG. 1 is an enlarged sectional view of the main part, FIG. 2 is a life characteristic diagram, and FIG.
Figures 5 to 5 are diagrams showing a conventional layered cathode device of this kind.
Figure 8 is a plan view, Figure 4 is a plan view of main parts, and Figure 5 is a cross-sectional view. , 11 is a metal powder sintered layer. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] A base metal deposited on one surface of a heat-resistant insulating substrate, a metal powder sintered layer deposited on the base metal, an electron-emitting material deposited on the metal powder sintered layer, and the heat-resistant A laminated cathode device equipped with a heater formed on the other side of an insulating substrate.