CN110820031A

CN110820031A - Preparation method of miniature getter

Info

Publication number: CN110820031A
Application number: CN201911131779.XA
Authority: CN
Inventors: 龙晓川; 赵彦弘; 徐晓强; 张庆猛
Original assignee: GRIMN Engineering Technology Research Institute Co Ltd
Current assignee: Beijing General Research Institute for Non Ferrous Metals; GRIMN Engineering Technology Research Institute Co Ltd
Priority date: 2019-11-19
Filing date: 2019-11-19
Publication date: 2020-02-21

Abstract

The invention discloses a preparation method of a micro getter, belonging to the technical field of manufacturing of getter materials, comprising the following steps: weighing the getter powder, the charging agent and the dispersing agent which are well proportioned, and preparing to obtain an electrophoresis solution; the counter electrode is an anode, the deposition electrode is a cathode, and the counter electrode and the deposition electrode are respectively and correspondingly connected to the anode and the cathode of the direct-current power supply; starting a circulating pump or a magnetic stirrer for stirring; putting the two electrodes into the electrophoretic solution, starting a power supply to deposit getter particles under the action of an electric field, and adjusting the deposition time according to the required deposition thickness; and sintering the deposit by using a vacuum sintering furnace after the deposition is finished to obtain the getter. The invention has the characteristics of simple manufacturing device and process, low cost, miniaturization of the prepared getter device, unconstrained shape and small influence of human factors. The getter is complementary to methods such as compression molding, injection molding, loose sintering and the like, and the product types of the getter are enriched.

Description

Preparation method of miniature getter

Technical Field

The invention belongs to the technical field of manufacturing of getter materials, and particularly relates to a preparation method of a miniature getter.

Background

In recent years, miniaturization and precision development of vacuum electronic devices have made higher demands on the performance of internal heating type hot-type getters, and internal heating type getter elements with simple and convenient manufacturing process, low cost, good consistency and high reliability are urgently required in the industry. The development requirements are difficult to meet by methods such as loose sintering and the like, wherein the diameter is

The heater type getter has high requirements on the precision of a mold by adopting the existing mold production process, the production cost is greatly improved, an insulating layer is needed between the getter of a large-diameter getter product prepared by loose sintering and a heating wire, otherwise, the getter cannot be heated to an activation temperature due to too small resistance, the demolding is difficult, and the shape of a device is severely limited. The getter is prepared by electrophoretic deposition without a mould.

Disclosure of Invention

Aiming at the problems, the invention provides a preparation method of a micro getter, which comprises the following steps:

1) weighing the getter powder and the charging agent in proportion, uniformly mixing, and fully grinding to obtain a mixture A;

2) selecting a proper dispersing agent, and dissolving the mixture A into the dispersing agent to obtain an electrophoretic solution;

3) taking the counter electrode as an anode and the deposition electrode as a cathode, and respectively and correspondingly connecting the counter electrode and the deposition electrode to a positive electrode and a negative electrode of a direct current power supply;

4) pouring the electrophoretic solution into an electrophoretic solution container, starting a circulating pump or a magnetic stirrer to stir;

5) slowly putting the deposition electrode and the counter electrode into the electrophoretic solution, starting a direct-current power supply to deposit the getter particles under the action of an electric field, and adjusting the deposition time according to the required deposition thickness;

6) after the deposition is finished, closing the circulating pump, the magnetic stirrer and the direct current power supply, and taking out the deposition electrode and the counter electrode;

7) and sintering the deposition electrode by using a vacuum sintering furnace to obtain the getter.

The getter prepared by said method has a minimum thickness of < 1 mm.

The getter powder in the step 1) is as follows: zr: ZrVFe is 8:2, the charging agent is magnesium nitrate, and the ball milling is carried out by using a planetary ball mill for 3 h.

The dispersing agent in the step 2) is ethanol.

The deposition electrode in the step 3) is made of a material for activating a getter, and the counter electrode is made of a metal material or a non-metal material.

In the step 3), the deposition electrode is a tungsten-rhenium wire, the diameter of the tungsten-rhenium wire is 0.2mm, and the counter electrode is a molybdenum wire or a graphite rod.

The blade material of the circulating pump in the step 4) is copper alloy, so that corrosion is prevented, and the sealing performance of the circulating pump is good.

In the step 5), the power supply voltage is 30V, the electrophoresis time is 2min, and the deposition thickness of the getter is 0.4 mm.

The sintering temperature of the deposition electrode was 950 ℃.

The invention has the beneficial effects that:

1. the technical task of the invention is to provide a method and a device for preparing a miniature getter to solve the problems, and the production of the getter is promoted to be miniaturized by very low cost. The getter prepared by the electrophoretic deposition method can directly carry out electrophoretic deposition on getter powder on an electrode, wherein the electrode is a heating wire used for activating the getter, and the problems that the getter is difficult to demould and is easy to damage the shape of a device in the prior art are solved.

2. The electrophoretic deposition device is simple and low in cost, and the getter device prepared by the method has the characteristics of miniaturization, unconstrained shape and small influence of human factors; the method makes up the limitations of methods such as compression molding, injection molding, loose sintering and the like, forms complementation and enriches the product types of the getter.

Drawings

FIG. 1 is a diagram of an apparatus for preparing a micro getter in example 1 of the present invention;

FIG. 2 is a diagram showing an apparatus for preparing a micro getter in example 2 of the present invention;

wherein:

1-circulating pump, 2-deposition electrode, 3-counter electrode, 4-electrophoresis liquid container, 5-power supply electrode, 6-magneton, 7-direct current power supply, 8-magnetic stirrer.

Detailed Description

The invention is described in further detail below with reference to the following figures and specific examples:

as shown in fig. 1 and 2, a stirring device, a reaction device and a direct current power supply 7 are connected in sequence, the stirring device is a circulating pump 1 or a magnetic stirrer 8, the reaction device comprises a deposition electrode 2, a counter electrode 3 and an electrophoresis solution container 4, the counter electrode 3 and the deposition electrode 2 are respectively connected with the positive electrode and the negative electrode of the direct current power supply 7 through leads, and in the using process, the deposition electrode 2 and the counter electrode 3 are soaked in the electrophoresis solution of the electrophoresis solution container 4; the circulating pump 1 or the magnetic stirrer stirs the electrophoretic fluid in the electrophoretic fluid container 4 to keep the electrophoretic fluid in a suspended state. The powder in the electrophoretic liquid is getter powder, and the getter powder can be an existing getter system and can also be a new getter system.

The getter does not need to be stripped from the electrode, which is the heating wire of the product, and can be successfully activated by current due to the small diameter of the getter. The electrophoretic deposition technology does not need a mould, the demoulding process does not exist, the shape of the electrophoretic deposition electrode is basically not limited, the getter is deposited on the electrode, the shape is the same as that of the electrode, and therefore the shape of the product is slightly limited.

Example 1:

the getter powder comprises the following components in percentage by weight: zr: ZrVFe is 8:2, ethanol is used as a dispersing agent for an electrophoretic solution, magnesium nitrate is used as a charging agent, the mass ratio of the charging agent to a solvent is 0.46 ten thousandth, and a planetary ball mill is used for ball milling for 3 hours. Taking the deposition electrode 2 as a cathode, wherein the cathode is a tungsten-rhenium wire with the diameter of 0.2mm and is connected with the cathode of the power supply electrode 5; the counter electrode 3 is an anode made of molybdenum sheet and is connected with the anode of the power supply electrode 5.

The manufacturing method comprises the following steps:

1) after the electrophoresis liquid is poured, the circulating pump 1 is immediately started, and the circulating pump 1 needs to be kept in a starting state all the time in the whole experiment process.

2) Slowly placing the deposition electrode 2 into the electrophoresis solution, turning on the DC power supply 7, adjusting voltage to appropriate value, allowing the charged getter particles to move toward the deposition electrode 2 under the action of electric field and deposit and gather at the position, selecting 30V power supply voltage, and performing electrophoresis for 2min,

3) the power supply was turned off and the deposition electrode 2 was removed, and the thickness of the getter coating was about 0.4 mm. After the circuit is connected, the direct current power supply 7 is started, the voltage is adjusted to a proper value, the charged getter particles move towards the deposition electrode 2 under the action of an electric field and are deposited and gathered at the deposition electrode, and the thickness of the getter layer can be controlled by selecting the time, so that different air suction capacities are guaranteed.

4) Sintering in a vacuum sintering furnace at 950 ℃.

Example 2:

the circulation device in fig. 1 is changed to a magnetic stirring device, as shown in fig. 2. The electrophoretic liquid ratio, the polishing conditions, the electrodes, and other test conditions were the same as in example 1.

The manufacturing method comprises the following steps:

1) after the electrophoretic solution is poured, the magnetic stirrer 8 is immediately started, and the rotating speed is adjusted to a proper value, so that the electrophoretic solution is not splashed, and the powder is preferably suspended uniformly.

2) This step is the same as step 2 in example 1).

3) Sintering in a vacuum sintering furnace at 950 ℃.

The getter device prepared by the electrophoresis method has the advantages of unchanged performance, various shapes, controllable thickness and low cost, is very beneficial to miniaturization, and reduces the capital pressure of downstream enterprises.

Claims

1. The preparation method of the miniature getter is characterized by comprising the following steps:

3) the counter electrode (3) is taken as an anode, the deposition electrode (2) is taken as a cathode, and the counter electrode and the deposition electrode are respectively and correspondingly connected to the positive electrode and the negative electrode of the direct current power supply (7);

4) pouring the electrophoretic solution into an electrophoretic solution container (4), and starting a circulating pump (1) or a magnetic stirrer (8) to stir;

5) slowly putting the deposition electrode (2) and the counter electrode (3) into the electrophoretic solution, starting a direct current power supply (7) to deposit getter particles under the action of an electric field, and adjusting the deposition time according to the required deposition thickness;

6) after deposition, closing the circulating pump (1), the magnetic stirrer (8) and the direct current power supply (7), and taking out the deposition electrode (2) and the counter electrode (3);

2. The method of claim 1, wherein the getter produced by the method has a minimum thickness of < 1 mm.

3. The method as claimed in claim 1, wherein the getter powder in step 1) is: zr: ZrVFe is 8:2, the charging agent is magnesium nitrate, and the ball milling is carried out by using a planetary ball mill for 3 h.

4. The method as claimed in claim 1, wherein the dispersant in step 2) is ethanol.

5. The method according to claim 1, wherein the deposition electrode (2) in step 3) is a material for activating a getter, and the material of the counter electrode (3) is a metallic material or a non-metallic material.

6. The method according to claim 1, characterized in that the deposition electrode (2) in step 3) is a tungsten-rhenium wire with a diameter of 0.2mm, and the counter electrode (3) comprises a molybdenum wire or a graphite rod.

7. The method as claimed in claim 1, wherein the circulating pump blade material in the step 4) is copper alloy, corrosion is prevented, and the circulating pump (1) has good sealing performance.

8. The method as claimed in claim 1, wherein the power voltage in step 5) is 30V, the electrophoresis time is 2min, and the deposition thickness of the getter is 0.4 mm.

9. The method of claim 1, wherein the sintering temperature of the deposition electrode is 950 ℃.