JPH03201346A - Lamination type cathode device - Google Patents

Abstract

PURPOSE:To improve reliability of the welding part between a lead wire and a pin and reduce the dispersion of cut-off voltage by supportedly connecting a heat-resistant insulating substrate to a cathode pin and a lead wire L-shapedly folded to a heater pin. CONSTITUTION:A heat-resistant insulating substrate 1 is supportedly connected by means of cathode pins 7, plantedly erected on a cathode vessel 6, and lead wires 9 L-shapedly folded to heater pins 8. Here the lead wires 9 are welded to the heater terminals 53 and the cathode terminals 31 on 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 1 to be heated, and the heating of substrate metal 2 to high temperature causes barium oxide, which is a component of an electron radiation substance 4 layer, and the substrate metal 2 to make reaction to conduct electron radiation with Ba, produced by the reaction, as a donor. This high temperature action causes a lead wire 6 to rise to high temperature to make thermal expansion, but because the lead wire 6 is displaced to a dotted line shown condition, the stress to the welding point of the heater pin 8 or the cathode pin 7 is relaxed. This permits reliability improvement of the welding part and reduction of the dispersion of cut-off voltage.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a laminated cathode device used in an in-line color cathode ray tube, particularly a structure that reduces variations in cant-off voltage and improves the reliability of bath contacts of conducting wires. It is related to.

(Prior art) Figures 6 to 8 are diagrams showing a conventional cathode device of this type.
In the figure, l is a heat-resistant insulating substrate made of sapphire with a thickness of about 0.1 to 0.4 fl, and 2 is a heat-resistant insulating substrate 1 in which tungsten is deposited in a straight line on one surface of the heat-resistant insulating substrate 1 by a method such as sputtering. The base metal 3 was then etched into a predetermined shape using photolithography technology, and was integrally deposited on a heat-resistant insulating substrate in the same manner as the base metal 2. A cathode terminal 31 was formed at the tip. The lead wires 4 were formed on the eight base metals 2 by a method such as spraying (
Electron-emitting material 51 is made of an alkaline earth metal oxide such as Ba, 81,0a)0, etc., and a thin film of tungsten is deposited by sputtering on the other side of the heat-resistant insulating substrate l, at a portion opposite to the base metal 2. After that, the heating element formed into a serpentine shape by etching is integrally formed with the eight heating elements 51, and the conducting wire and wings connecting the heating elements in series are attached together with the heating element 51 and the conductor 11A32. Heater terminals constituting the heater 5, 6 is a steatite cathode container, 7 is a cathode pin planted in the cathode container 6, 8 is a heater pin planted in the cathode container 6, 9 is a cathode terminal 31 and a cathode pin 7 and a conductor connecting the heater terminal portion and the heater pin 8; 10, eight electron beam passing holes 101 arranged at intervals of about 0.111 with respect to the metal base 2 and the electron emitting material 4;
The first grid of the electron gun has a

In this conventional device, when a voltage is applied across the heater pin 8, a current flows through the heating element 51, and Joule heat is determined by the product of the square of the current, the electrical resistance of the heating element 51, and time, as shown in the formula below. Occurs in quantity.

Q=I'XRXf Here, Q is the amount of heat, ■ is the current, B is the resistance, and t is the time.

This generated heat heats the eight base metals 2 through the heat-resistant insulating substrate 1 by thermal conduction and thermal radiation. solid metal 2
When heated to an operating fit degree of about 8000, pao, 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 play jliHa
acts as a donor, and an electron beam is emitted from the electron emitting material 4, causing the eight-color fluorescent surface of the color cathode ray tube to glow. The amount of this electron beam changes depending on the potential between the first grind 10 and the cathode. 2 or the conductive heat from the heating element increases the temperature of the conductor 9 to a high temperature of approximately 700 C. Due to this temperature rise and the temperature rise of the heat-resistant insulating substrate 1, the heat-resistant insulating substrate 1 and the conductor 9 undergo thermal expansion. This may cause stress due to thermal expansion to be applied to the welding points of the heater pin 8 and the cathode pin 7 with the conductive wires 9, and the welds may come off.

Further, if the welding does not come off, the conductive wire 9 is bent into a convex or concave shape due to stress, and the heat-resistant insulating substrate 1 is displaced upward or downward from the initial reference plane. The displacement of the heat-resistant insulating plate 1 causes a change in the distance between the first grid lO and the electron emitting material 4, which promotes variations in the cutoff voltage, which is one of the electrical characteristics of the electron gun.

[Problem to be solved by the invention]

Since the conventional laminated cathode device is constructed as described above, there has been a problem in that the reliability of the welded portion of the conductor wire and the variation in the electric power output are increased.

This invention was made to solve these problems, and provides an improved laminated cathode device for the purpose of improving the reliability of the weld between the conductor and the pin and reducing the variation in cut-off voltage. This is what we are trying to provide.

[Means to solve the problem]

The laminated cathode device according to the present invention includes an electron-emitting substance deposited on a base metal formed on one surface of a heat-resistant insulating substrate, a heater deposited on the other surface of the heat-resistant insulated substrate, and a heater formed on the other surface of the heat-resistant insulated substrate. , L to the cathode pin and heater pin installed in the cathode container.
A heat-resistant insulating substrate is supported and connected by conductive wires bent into a letter shape.

[Effect]

In this invention, since the conducting wire is made into a bent shape,
The stress due to thermal expansion applied to the bath contact between the conducting wire and the cathode pin or heater pin is alleviated, the reliability of the welding point is improved, and displacement of the heat-resistant insulating substrate can be reduced.

〔Example〕

An embodiment of the present invention will be explained below in detail based on FIGS. 1 to 8. In other words, in FIGS.
As shown in the figure, the diameter 0.0mm is bent into an L shape so that the dimension M is 2m and the dimension B is 8n. It is made of In platinum wire and connects the cathode terminal 31 and the cathode pin 7 and the heater terminal portion and the heater pin 8.

Here, the conductor 9 is welded to the heater terminal part and the cathode terminal 31 of the heat-resistant insulating board l using a parallel gap welding machine.
bathed in Then, the cathode pin 7 and the heater pin 8
The cathode device is completed by welding and fixing it using the parallel gap welding method suitable for

Note that the other configurations are the same as those of the conventional device shown in FIGS. 6 to 8, so the explanation will be omitted.

With this configuration, when a voltage is applied to the heating element 51, the heating element 51 generates heat by Joule heat, as in the conventional case. The heat-resistant insulating substrate 1 is heated by the radiant heat and conductive heat caused by this Joule heat ^ Substrate gold 1
When 42 is heated to a high temperature of about soo c, barium oxide, which is a component of the four layers of electron emitting material, reacts with the base metal 2, and Ba generated in this reaction becomes a donor to emit electrons.

Due to this high-temperature operation, the conductive wire 6 is humidified to a high temperature of about 700° C. and undergoes thermal expansion, but is displaced to the state shown by the dotted line in FIG. 2.

Therefore, the stress on the welding points of the heater pin 8 and cathode pin 7 is alleviated. Since stress due to thermal expansion can be relaxed in this way, curved deformation of the conducting wire 9 can also be reduced.

FIG. 8 shows the variation in cutoff voltage in this example, and is compared with a conventional laminated cathode device. As can be seen from this figure, the variation in the power output 7wL pressure, which was conventionally 270v to 450v, could be reduced to 810v to 410V in this embodiment.

FIG. 4 shows another embodiment, in which the same effect can be obtained even if the conductor 1Ij19 is made in a shape other than L-shape.
Furthermore, FIG. 5 shows another embodiment in which the conductor 1s9 is bent at 90 degrees with respect to the flat surface of the heat-resistant insulating substrate 1, so that the same effect is obtained.

〔Effect of the invention〕

As described above, in the laminated cathode device according to the present invention, since the heat-resistant insulating substrate is supported and connected to the cathode pin and the heater pin by the conductor wire bent in an L shape, it is possible to suppress displacement of the heat-resistant insulating substrate, and Reliability is improved because the stress caused by thermal expansion at the welding point between the pin and the conductor can be reduced.

[Brief explanation of drawings]

Figures 1 to 8 are diagrams showing one embodiment of the present invention.
The figure is a plan view of the main part, FIG. 2 is an enlarged plan view of the main part, FIG. 8 is a characteristic diagram, FIGS. 4 and 5 are views showing other embodiments of the present invention, and FIG. FIG. 5 is a schematic plan view, FIG. 5 is a side view of the main part, FIGS. 6 to 8 are diagrams showing this kind of conventional wood layered cathode device, FIG. 6 is a plan view, FIG. 7 is a plan view of the main part, FIG. 8 is a sectional view. In the figure, l is a heat-resistant insulating substrate, 2 is a base metal, 4 is an electron emitting material, 51 is a heating element, 6 is a cathode container, 7 is a cathode pin,
8 is a heater pin, and 9 is a conductor. Note that the same reference numerals in the figures indicate the same -1 or equivalent parts.

Claims (1)

[Claims] A base metal formed on one side of the heat-resistant insulating substrate, an electron-emitting material formed on the base metal, a heater formed on the other side of the heat-resistant insulated substrate, and planted in the cathode container. A laminated cathode device comprising a heater pin and a cathode pin, a conductive wire bent into an L-shape and supporting and connecting the heat-resistant insulating substrate to the heater pin and cathode pin.