Low-residual-voltage high-voltage discharge tube and manufacturing process thereof

Abstract

The invention is applicable to the technical field of gas discharge tubes, and provides a low-residual-voltage high-voltage discharge tube and a manufacturing process thereof.The low-residual-voltage high-voltage discharge tube comprises a metalized ceramic tube and two annular electrodes, and at least one conductive carbon wire is fixedly arranged on the inner side wall of the metalized ceramic tube; the two annular electrodes are fixedly arranged at pipe openings in the two ends of the metalized ceramic pipe respectively, the annular electrodes and the metalized ceramic pipe form a closed discharge chamber through packaging equipment, the discharge chamber is filled with process gas, the process gas comprises argon, nitrogen, hydrogen, helium and the like, electronic powder coating materials are arranged on protruding parts of the annular electrodes in a high-temperature curing mode, and the electronic powder coating materials are arranged on the metalized ceramic pipe. The electronic powder coating is prepared by mixing various metal salt powder and metal powder, and the effect of reducing residual voltage is achieved by improving the formula of the electronic powder coating at the discharge end of the annular electrode and improving the formula of process gas in the discharge chamber, so that the residual voltage is close to direct current voltage.

Description

Technical Field

[0001] The invention is applicable to the technical field of gas discharge tubes and provides a low residual voltage high voltage discharge tube and a production process thereof. Background Art

[0002] The discharge tube is a high-voltage protection component used at the input end of the equipment. If the voltage at both ends is higher than its protection specification value, a short circuit will occur inside it and absorb the input overvoltage. In the power supply EMC surge test, the residual voltage of ordinary discharge tubes on the market is generally 1000V-1500V higher than the DC breakdown voltage. The product reacts slowly, resulting in weak protection capabilities, which can easily cause problems such as power supply motherboard freeze and reset. It is necessary to design a new type of low residual voltage high-voltage discharge tube to effectively reduce the residual voltage during the EMC surge test, improve the reaction speed, and effectively protect the core chip of the subsequent circuit. Summary of the invention

[0003] To this end, the present invention provides a low residual voltage high-voltage discharge tube and its production process, which achieves the effect of reducing the residual voltage by improving the formula of the electronic powder coating on the discharge end of the annular electrode and the formula of the process gas in the discharge chamber, so that the residual voltage is close to the DC voltage.

[0004] In order to achieve the above object, the present invention provides the following technical solution: a low residual voltage high voltage discharge tube, comprising:

[0005] A metallized ceramic tube, wherein at least one conductive carbon wire is fixedly disposed on the inner side wall of the metallized ceramic tube;

[0006] Two annular electrodes are fixedly arranged at the two end openings of the metallized ceramic tube respectively. The two annular electrodes and the metallized ceramic tube form a closed discharge chamber, and the discharge chamber is filled with process gas. The annular electrode includes a protrusion, which is arranged in the discharge chamber and fixedly provided with an electronic powder coating.

[0007] Furthermore, the process gas is a mixture of at least the following gases in proportion by volume: 1 to 3 parts of argon, 5 to 6 parts of nitrogen, 0.5 to 1.5 parts of hydrogen, and 0.5 part of helium.

[0008] Furthermore, the electronic powder coating is prepared by mixing at least the following metal salt powders or metal powders in the following weight proportions: 20-30 parts of sodium bromide, 5-10 parts of sodium silicate, 2-8 parts of titanium dioxide, 6-8 parts of potassium silicate, 1-6 parts of zirconium oxide, 1-3 parts of cesium carbonate, 1-3 parts of cesium tungstate, 1-3 parts of cesium silicate, 1-3 parts of potassium chloride, 2 parts of nickel powder, and 2 parts of aluminum powder.

[0009] Furthermore, the number of the conductive carbon wires is four, and the four conductive carbon wires are arranged in a circular array at intervals of 90° on the inner wall of the metallized ceramic tube.

[0010] Furthermore, a grid groove is provided in the middle of the end surface of the raised portion, and the electronic powder coating is provided in the grid groove.

[0011] At the same time, a production process for a low residual voltage high voltage discharge tube is provided, comprising the following steps:

[0012] S1. Apply the electronic coating to the grid grooves of the two annular electrode protrusions by coating tooling, and then place the two annular electrodes into an oven for baking to cure the electronic coating;

[0013] S2. several conductive carbon wires are arranged on the inner wall of the metallized ceramic tube, and then the two annular electrodes prepared in step S1 are respectively installed at both ends of the metallized ceramic tube;

[0014] S3. Place the metallized ceramic tube and the two annular electrodes assembled together in step S2 into a vacuum packaging device for packaging. During the packaging process, the air in the discharge chamber is first evacuated, and then the process gas is injected into the discharge chamber. Finally, the connection position of the metallized ceramic tube and the two annular electrodes is sealed and connected.

[0015] Furthermore, in the step S3, the packaging temperature is 820°C to 850°C.

[0016] Furthermore, in the step S3, the connection positions of the metallized ceramic tube and the two annular electrodes are sealed and connected by welding.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention adopts an annular electrode to increase the current capacity and change the pulse discharge gap to reduce the residual pressure. At the same time, the residual pressure is effectively reduced by optimizing the formula of the electronic powder coating at the discharge end of the annular electrode and the formula of the process gas in the discharge chamber;

[0019] 2. The pulse breakdown voltage is effectively reduced by adding conductive carbon wires to the inner wall of the metallized ceramic tube. The reason for setting four conductive carbon wires at the same time is to prevent the remaining conductive carbon wires from continuing to work when a single conductive carbon wire fails, thereby ensuring the effect of reducing the pulse breakdown voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the decomposed structure of a low residual voltage high voltage discharge tube mentioned in the present invention;

[0021] Figure 2The figure is a schematic cross-sectional view of the internal structure of a low residual voltage high-voltage discharge tube mentioned in the present invention.

[0022] In the figure: 1. metallized ceramic tube, 2. annular electrode, 21. raised portion, 3. electronic powder coating, 4. conductive carbon wire. DETAILED DESCRIPTION

[0023] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0024] Example 1, refer to the attached Figure 1 ~Attached Figure 2 The present invention provides a low residual voltage high-voltage discharge tube, comprising a metallized ceramic tube 1 and two annular electrodes 2. Four conductive carbon wires 4 are fixedly arranged on the inner wall of the metallized ceramic tube 1. The two annular electrodes 2 are respectively fixedly arranged at the two end tube openings of the metallized ceramic tube 1. Four conductive carbon wires 4 are fixedly arranged on the inner wall of the metallized ceramic tube 1. The four conductive carbon wires 4 are arranged in an annular array at an interval of 90° in the middle of the inner wall of the metallized ceramic tube 1. The conductive carbon wires 4 can effectively reduce the pulse breakdown voltage. The four conductive carbon wires 4 all work independently. When one or more of the conductive carbon wires 4 fail, the remaining conductive carbon wires 4 can still achieve the effect of reducing the pulse breakdown voltage. The two annular electrodes 2 are respectively fixedly arranged at the two end tube openings of the metallized ceramic tube 1. The two annular electrodes 2 and the metal The inner space of the ceramic tube 1 forms a closed discharge chamber, which is filled with process gas. The process gas is made by mixing multiple gases, including argon, nitrogen, hydrogen and helium. While achieving the DC voltage of the product, the residual pressure can be effectively reduced. The annular electrode 2 includes a protrusion 21, which is arranged in the discharge chamber. A grid groove is arranged in the middle position of the end face of the protrusion 21, and an electronic powder coating 3 is added to the grid groove. The grid groove structure is used to increase the adhesion of the electronic powder coating 3 and improve its service life. The electronic powder coating 3 is made by mixing multiple metal salt powders and metal powders, including sodium bromide, sodium silicate, titanium dioxide, potassium silicate, zirconium oxide, cesium carbonate, cesium tungstate, cesium silicate, potassium chloride, nickel powder and aluminum powder, which can improve the flow capacity and reduce the pulse voltage.

[0025] At the same time, this embodiment also provides a production process for a low residual voltage high voltage discharge tube, including the following steps:

[0026] S1. The electronic coating is applied to the grid grooves of the two annular electrodes 2 by coating tooling, and then the two annular electrodes 2 are placed in an oven for baking to cure the electronic coating;

[0027] S2. A plurality of conductive carbon wires 4 are arranged on the inner wall of the metallized ceramic tube 1, and then the two annular electrodes 2 prepared in step S1 are respectively installed at both ends of the metallized ceramic tube 1;

[0028] S3. Place the metallized ceramic tube 1 and the two annular electrodes 2 assembled together in step S2 into a vacuum packaging device for packaging at a packaging temperature of 820°C to 850°C. During the packaging process, firstly, the air in the discharge chamber is evacuated, and then the process gas is injected into the discharge chamber. Finally, the connection position between the metallized ceramic tube 1 and the two annular electrodes 2 is sealed and connected by welding.

[0029] The following are three process gas formulations used in different embodiments (the following gases are all in volume fractions):

[0030] Process gas formula A: 3 parts argon, 5 parts nitrogen, 0.5 parts hydrogen, 0.5 parts helium;

[0031] Process gas formula B: 2 parts argon, 6 parts nitrogen, 0.5 parts hydrogen, 0.5 parts helium;

[0032] Process gas formula C: 1 part argon, 6 parts nitrogen, 1.5 parts hydrogen, and 0.5 parts helium.

[0033] At the same time, five electronic powder coating material 3 formulas used in different embodiments are listed (the following components are all in parts by mass):

[0034] Electronic powder coating 3 formula A: 20 parts of sodium bromide, 5 parts of sodium silicate, 2 parts of titanium dioxide, 8 parts of potassium silicate, 1 part of zirconium oxide, 1 part of cesium carbonate, 1 part of cesium tungstate, 1 part of cesium silicate, 3 parts of potassium chloride, 2 parts of nickel powder, 2 parts of aluminum powder;

[0035] Electronic powder coating 3 formula B: 25 parts of sodium bromide, 5 parts of sodium silicate, 3 parts of titanium dioxide, 6 parts of potassium silicate, 2 parts of zirconium oxide, 2 parts of cesium carbonate, 2 parts of cesium tungstate, 2 parts of cesium silicate, 1 part of potassium chloride, 2 parts of nickel powder, 2 parts of aluminum powder;

[0036] Electronic powder coating 3 formula C: 25 parts of sodium bromide, 8 parts of sodium silicate, 3 parts of titanium dioxide, 8 parts of potassium silicate, 6 parts of zirconium oxide, 3 parts of cesium carbonate, 3 parts of cesium tungstate, 3 parts of cesium silicate, 1 part of potassium chloride, 2 parts of nickel powder, 2 parts of aluminum powder;

[0037] Electronic powder coating 3 formula D: 30 parts of sodium bromide, 5 parts of sodium silicate, 2 parts of titanium dioxide, 8 parts of potassium silicate, 1 part of zirconium oxide, 1 part of cesium carbonate, 1 part of cesium tungstate, 1 part of cesium silicate, 3 parts of potassium chloride, 2 parts of nickel powder, 2 parts of aluminum powder;

[0038] Electronic powder coating 3 formula E: 30 parts of sodium bromide, 10 parts of sodium silicate, 8 parts of titanium dioxide, 8 parts of potassium silicate, 1 part of zirconium oxide, 1 part of cesium carbonate, 1 part of cesium tungstate, 1 part of cesium silicate, 3 parts of potassium chloride, 2 parts of nickel powder, and 2 parts of aluminum powder.

[0039] By combining different process gas formulas with the formulas of the electronic powder coating 3, 15 kinds of low residual voltage high-voltage discharge tubes in the following Examples 1 to 15 are obtained. By conducting simulated working condition tests on the 15 kinds of low residual voltage high-voltage discharge tubes mentioned in Examples 1 to 15, the test data obtained are shown in the following table:

[0040]

[0041] From the above table, it can be seen that the combination of the process gas formula and the electronic powder coating 3 formula in these 15 embodiments can meet the requirement of residual voltage less than 4000V, which meets the requirements for terminal line use. Among them, the increase of hydrogen content in the process gas can reduce the residual voltage, and the increase of potassium silicate, cesium carbonate, cesium silicate, and cesium tungstate in the electronic powder coating 3 formula can also effectively reduce the residual voltage. Based on the above results, the electronic powder coating 3 formula C and the process gas formula C scheme used in Example 9 (i.e., electronic powder coating 33 formula C: 25 parts of sodium bromide, 8 parts of sodium silicate, 3 parts of titanium dioxide, 8 parts of potassium silicate, 6 parts of zirconium oxide, and 6 parts of carbon dioxide) are as follows: 3 parts of cesium tungstate, 3 parts of cesium tungstate, 3 parts of cesium silicate, 1 part of potassium chloride, 2 parts of nickel powder, 2 parts of aluminum powder; and process gas formula C: 1 part of argon, 6 parts of nitrogen, 1.5 parts of hydrogen, and 0.5 parts of helium. ), whether it is the test results of 4KV mixed wave residual voltage value or 6KV mixed wave residual voltage value, it is the optimal value, and the minimum between the DC breakdown voltage, so embodiment 9 is the best embodiment of the present invention. The low residual voltage high-voltage discharge tube in this embodiment achieves extremely low residual voltage, and the residual voltage is close to the DC voltage. By changing the surge pulse discharge tube gap, changing the formula of the electronic powder coating 3, and the process gas formula, the goal of effectively reducing the residual voltage is achieved.

[0042] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0043] The above are only preferred embodiments of the present invention. Any person skilled in the art may modify the present invention by using the above technical solutions or modify it into an equivalent technical solution. Therefore, any simple modification or equivalent replacement made according to the technical solution of the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A low residual voltage high voltage discharge tube, characterized in that: include: A metallized ceramic tube (1), wherein at least one conductive carbon wire (4) is fixedly arranged on the inner side wall of the metallized ceramic tube (1); Two annular electrodes (2) are respectively fixedly arranged at the two end openings of the metallized ceramic tube (1); the two annular electrodes (2) and the metallized ceramic tube (1) form a closed discharge chamber, the discharge chamber is filled with process gas, the annular electrode (2) comprises a protrusion (21), the protrusion (21) is arranged in the discharge chamber, and the protrusion (21) is fixedly provided with an electronic powder coating (3).

2. The low residual voltage high voltage discharge tube according to claim 1, characterized in that: The process gas is a mixture of at least the following gases in proportion by volume: 1 to 3 parts of argon, 5 to 6 parts of nitrogen, 0.5 to 1.5 parts of hydrogen, and 0.5 parts of helium.

3. The low residual voltage high voltage discharge tube according to claim 2, characterized in that: The electronic powder coating (3) is prepared from at least the following metal salt powders or a mixture of metal powders in parts by weight: 20-30 parts of sodium bromide, 5-10 parts of sodium silicate, 2-8 parts of titanium dioxide, 6-8 parts of potassium silicate, 1-6 parts of zirconium oxide, 1-3 parts of cesium carbonate, 1-3 parts of cesium tungstate, 1-3 parts of cesium silicate, 1-3 parts of potassium chloride, 2 parts of nickel powder, and 2 parts of aluminum powder.

4. The low residual voltage high voltage discharge tube according to claim 1, characterized in that: The number of the conductive carbon wires (4) is four, and the four conductive carbon wires (4) are arranged in a circular array at intervals of 90 degrees on the inner wall of the metallized ceramic tube (1).

5. The low residual voltage high voltage discharge tube according to claim 1, characterized in that: A grid groove is provided in the middle of the end surface of the raised portion (21), and the electronic powder coating (3) is arranged in the grid groove.

6. A manufacturing process for a low residual voltage high voltage discharge tube according to any one of claims 1 to 5, characterized in that: The steps include: S1. Applying the electronic coating to the grid grooves of the raised portions (21) of the two annular electrodes (2) by means of a coating tool, and then placing the two annular electrodes (2) in an oven for baking to cure the electronic coating; S2. A plurality of conductive carbon wires (4) are arranged on the inner wall of the metallized ceramic tube (1), and then the two annular electrodes (2) prepared in step S1 are respectively installed at both ends of the metallized ceramic tube (1); S3. The metallized ceramic tube (1) and the two annular electrodes (2) assembled together in step S2 are placed in a vacuum packaging device for packaging. During the packaging process, the air in the discharge chamber is firstly evacuated, and then the process gas is injected into the discharge chamber. Finally, the connection position of the metallized ceramic tube (1) and the two annular electrodes (2) is sealed and connected.

7. The manufacturing process of a low residual voltage high voltage discharge tube according to claim 6, characterized in that: In the step S3, the packaging temperature is 820°C to 850°C.

8. The manufacturing process of a low residual voltage high voltage discharge tube according to claim 6, characterized in that: In the step S3, the connection positions of the metallized ceramic tube (1) and the two annular electrodes (2) are sealed and connected by welding.

Images