RU1817155C - Getter - Google Patents

Abstract

Usage: in electronic technology in the design and manufacture of vacuum devices. SUMMARY OF THE INVENTION: To increase sorption capacity and getter activity by forming a binary liquid eutectic titanium-copper alloy. The composition of the gas-absorbing material introduced copper in the following ratio of components, wt.%: Titanium 10-70, copper 90-30.

Description

The invention relates to electronic equipment and may find application in the design and manufacture of electronic vacuum devices.

The purpose of the invention is to increase the sorption capacity and activity of the getter, due to the formation of a binary liquid eutectic alloy.

The goal is achieved in that the composition of the getter material introduced copper in the following ratio of components, wt.%:

titanium 10-70 copper 90-30 The essence of the invention lies in the fact that a blank of a getter is placed on the inner horizontal metal surface of the shell of metal-ceramic and titanium-ceramic devices.

The getter blank consists of compactly bonded by spot welding, pressing parts or powders of titanium and copper. The getter blank is also placed in a container that is attached to the electrodes of the device using holders. The container is made of metal, which does not form a eutectic alloy with titanium and copper.

The getter is heated by heating the casing, as well as by passing current through the getter holder or by high-frequency heating when used in glass, metal-glass devices.

In the process of pumping electronic devices, the getter is heated by one of the above methods to 875-1050 ° C. Upon heating, the formation of a binary liquid eutectic titanium-copper alloy with the formation of intermetallic compounds T12Ciz, TiCu, TlaCu, TiCus. The presence of various intermetallic compounds plays the role of germinal centers or the development of getter reactions; as a result, the absorption capacity increases sharply,

During the mixing of the layers of the electric liquid alloy, the titanium compounds with the gases and the gas with the intermetallic phases sink in the volume of the alloy, i.e. move deep into the alloy to a considerable depth. This allows

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Destroy the crust of reaction products of the getter material with gases.

Mixing the alloy additionally contributes to an increase in the rate of absorption of gases and an increase in the sorption capacity of the getter, while the whole mass of getter is involved in the absorption of the basics. The initial depth of placement of titanium compounds and intermetallic phases with gases in the gas-hardener, which has hardened after cooling, substantially reduces the rate of its gas separation. in operation ..

These factors contribute to a decrease in residual gas pressure in the internal volume of the device. The decrease in the pressure of the intra-lamp atmosphere was estimated by measuring the level of ionic (reverse) current in the instrument grid with and without a copper-titanium getter, since there are no methods for directly measuring the pressure in the volume of the instrument. Measurements showed that the ion current level of the grid when setting the getter on average decreased from 0.0582 μA to 0.0284 μA, i.e. 2.05 times. It is known that the level of the intra-tube pressure (P) depending on the ion current of the grid I (lei ion) at a constant value of the anode current is determined by the expression P K ICi ion; where K is the coefficient of proportionality determined by the geometric parameters of the electrodes of the devices. A decrease in the concentration of gases in the intra-lamp volume reduces the rate of poisoning of the oxide cathode by residual gas. This makes it possible to reduce the degree of rejection of devices by low emission of the cathode or allows to increase the durability of the devices by decreasing the cathode temperature while maintaining the third level of emission parameters.

There are two eutectics in the titanium-copper system: one at 50 wt.% Titanium and a temperature of 950 ° C and the second at May 28. % titanium and a temperature of 875 ° C (table).

If the ratio of copper and titanium is not equilibrium, then a number of intermetallic compounds are formed with different melting points, ТССи - 1014 ° С, TiCu - 982 ° С, ТиСиз - 905 ° С, TICU2 - 892 ° С, - 935 ° C.

A copper-titanium getter was tested at a ratio of copper of 30-90 wt.%, Titanium of 70-10 wt.% With an assessment of the emissivity of the cathode and the level of ionic (reverse) grid current.

Highest anode current level (up to 78.9 mA and lowest ion current level)

a grid (up to 0.0284 µA) is available with a ratio of titanium of 19-50 wt.% and copper 81 - 50%. With a decrease in the titanium content to 10 wt.% (Copper to 90 wt.%), The current level

the anode decreases, the ion current level of the grid increases.

These results are explained by the fact that with a decrease in the titanium fraction, the amount of intermetallic compounds of titanium with copper decreases, which leads to a decrease in the absorption capacity of the getter.

An increase in copper content increases the amount of copper deposition on the cathode,

6 which reduces its emissivity. ......

An increase in titanium content to 70 wt.% Also leads to a decrease in emissivity, because with the specified

In the ratio of titanium to copper, not all titanium is combined into intermetallic compounds and part of the titanium remains in its pure form, i.e. in the form of metal not melted. In this case, the negative5 properties of titanium getters are manifested, i.e. a solid oxide film is formed on the surface of the getter, which reduces the absorption capacity of the getter.

0 The use of copper-titanium eutectic getter material allows you to irreversibly bind all oxygen-containing gases within the volume of the electronic device, reduce the total

5, the residual gas pressure is 2.12 times based on comparative measurements of the ion current of the grid of 1 devices in comparison with the prototype.

This allows you to significantly increase

0 emissivity of cathodes. The anode current of the ceramic-metal tetrodes during the installation of the copper-titanium getter material increased from 59.8 mA to 78.9 mA, i.e. at .1.32 times. This allowed to reduce

5, the voltage of the filament of the tetrodes from 6.3 to 5.7 V, while the required anode current level was saved. In accordance with the physical-statistical model of failure, the durability of the tetrode increased by 3 times.

Claims (1)

0 Formula from gaining A getter for electron tubes, including titanium, characterized in that, in order to increase the sorption capacity and activity of the getter for 5 due to the formation of a binary liquid eutectic alloy, the getter contains copper in the following ratio of components, wt.%: titanium 10-70 copper 90-30, Parameters of eutectic alloys.