A kind of carbon-oxygen-free copper multi-level depressurization collector and manufacturing approach
Technical field
The present invention relates to the vacuum electronic technical field, is a kind of carbon-oxygen-free copper multi-level depressurization collector and manufacturing approach, can be used for satellite travelling wave tube.
Background technology
Satellite travelling wave tube is widely used for payload technology such as communication, navigator fix, military mapping, microwave remote sensing, electronic reconnaissance, transfer of data as final stage power amplifier, is spaceborne core components and parts.
Use travelling wave tube as satellite, high efficiency is one of its core technology index.The efficient of travelling wave tube depends mainly on the organic efficiency of electronic efficiency and collector.After electronic efficiency reaches certain limit, be difficult to further improve, the raising of efficient at this moment depends primarily on the organic efficiency of collector again.External high efficiency travelling wave tube all adopts multi-level depressurization collector basically; Adopt the multi-level depressurization collector technology can the efficient of some frequency range travelling wave tube be brought up to more than 70%; The organic efficiency of collector can reach [list of references: Menninger W L, Benton R T, Choi M S more than 85%; Et al.70%EfficientKu-Band and C-Band TWTs for Satellite Downlinks; IEEE Transactionson Electron Devices, 2005,52 (5): 673-678].
The high efficiency multi-level depressurization collector can be realized from two aspects: one is from the electron optics design angle, to electron energy and distribution, flight path is calculated and simulate, for the collecting pole structure that designs high organic efficiency provides foundation; On the one hand,, select for use the little material of secondary electron yield in addition, perhaps electrode surface is carried out technical finesse, improve organic efficiency as the collector electrode from material and method angle.
Under the situation that structural design is confirmed, obtain higher organic efficiency, the collector electrode surface should have low secondary electron yield.Oxygen-free high conductivity type copper is most widely used multi-level depressurization collector electrode material; But the higher [list of references: Curren A N andJensen K A of its secondary electron yield; Secondary Electron Emission Characteristics ofIon-Textured Copper and High-Purity Isotropic Graphite Surfaces, NASA Technical Paper 2342 (1984); Ebihara B T and Ramins P, Design, Fabrication; And Performance of Small, Graphite DepressedCollectors With 200-W, CW; 8-18GHz Traveling-Wave Tubes, NASATechnical Paper 2693 (1987)].Adopt the ion beam process for modifying surface to make its surface that the alligatoring of micron or submicron-scale take place, can significantly reduce the secondary electron yield [list of references: Ebihara B T and Ramins P, Design on oxygen-free copper surface; Fabrication; AndPerformance of Small, Graphite Depressed Col lectors With 200-W, CW; 8-18GHz Traveling-Wave Tubes, NASA Technical Paper 2693 (1987); Curren A N, Jensen K A and Roman R F, Secondary Electron EmissionCharacteristics of Molybdenum-Masked, Ion-Textured OFHC Copper, NASA Technical Paper 2967 (1990)].But the ion beam surface modification needs special method equipment, and method mechanism is complicated, and influencing factor is more, causes processing procedure control difficulty bigger.And, the processing of practical work piece is also needed the frock jig of special, effect also receives certain limitation.The instructions for use that can its reliability satisfy space travelling wave tube under the condition that works long hours remains in all queries.
Adopt the little graphite type material (isotropic graphite and pyrolytic graphite etc.) of secondary electron yield also can obtain high organic efficiency; Carry out the ion beam modification processing on this basis again and can obtain better experiment effect [list of references: Ramins P and Curren A N; Performance ofTextured Carbon on Copper Electrode Multistage Depressed Collectorswith Medium-Power Traveling Wave tubes, NASA Technical Paper2665 (1986)].But the short texture of common graphite class material, air content are high, intensity is low, solderability is poor, in the application of multi-level depressurization collector, can bring more problem.
If thermal conductivity that oxygenless copper material is high and good brazing property and the low secondary electron yield of graphite type material combine; Can under the condition that guarantees heat-mechanical performance, improve the organic efficiency of multi-level depressurization collector, and then improve the efficient of homogeneous tube.
Summary of the invention
The objective of the invention is to disclose a kind of carbon-oxygen-free copper multi-level depressurization collector and manufacturing approach; Oxygen-free high conductivity type copper material with high heat conduction, easy soldering is substrate; At its surface deposition one deck carbon-coating, obtain multi-level depressurization collector through the vacuum ionic coating technology through assembling, welding.This multi-level depressurization collector electrode has utilized the characteristic of the low secondary of graphite type material, has avoided shortcomings such as graphite type material short texture, intensity are low, solderability difference simultaneously again, for the development of high efficiency satellite travelling wave tube provides new technical support.
For achieving the above object, technical solution of the present invention is:
A kind of carbon-oxygen-free copper multi-level depressurization collector comprises depressed collector electrode, insulating porcelain piece, outer sleeve, contact conductor; Its depressed collector electrode comprises oxygen-free copper substrate and carbon-coating two parts, except oxygen-free copper substrate column periphery circular surfaces part, all is covered with carbon-coating at oxygen-free copper substrate surfaces externally and internally; Oxygen-free copper substrate lower end is electrically connected with contact conductor; Oxygen-free copper substrate, insulating porcelain piece, outer sleeve are nested with one heart; The no coating area of oxygen-free copper substrate column periphery circular surfaces; Affixed with the insulating porcelain piece bore area; Insulating porcelain piece periphery circle is round affixed with interior week of outer sleeve, becomes the single-stage buck collector, stretches out in the fairlead of contact conductor by insulating porcelain piece; Again a plurality of single-stage buck collectors are assembled into multi-level depressurization collector on demand.
Described carbon-oxygen-free copper multi-level depressurization collector, its said depressed collector electrode, surface carbon layer thickness are 5-15 μ m; Between oxygen-free copper substrate and carbon-coating, be provided with titanium (Ti) transition zone.
Described carbon-oxygen-free copper multi-level depressurization collector, its said insulating porcelain piece is 95%, 99% aluminium oxide (Al
2O
3) or beryllium oxide (BeO) pottery, through metalized, plating nickel on surface (Ni); Contact conductor is a nickel wire; Outer sleeve is with no magnetic Monel material, wall thickness>=0.8mm.
A kind of manufacturing approach of described multi-level depressurization collector, it comprises step:
A) according to needing preparation depressed collector electrode, insulating porcelain piece, outer sleeve subsequent use;
B) contact conductor and depressed collector electrode is affixed;
The depressed collector electrode that C) will have a contact conductor with insulating porcelain piece, outer sleeve is concentric is nested with, be welded as a whole, a single-stage buck collector;
D) on demand, with the stacked affixed one-tenth multi-level depressurization collector of a plurality of single-stage buck collectors.
Described manufacturing approach, its said A) step preparation depressed collector electrode with oxygen-free copper substrate punch forming, covers ti interlayer at the non-welding region of oxygen-free copper substrate surface, uses physical gas-phase deposite method at transition zone surface deposition carbon-coating again; Cover in the process of ti interlayer, carbon-coating, oxygen-free copper substrate and insulating porcelain piece welding region are covered up with stainless steel retaining tool.
Described manufacturing approach, its said A) step preparation insulating porcelain piece, adopt conventional high temperature Mo-Mn method to carry out metalized to solder side after, electronickelling (Ni) layer, annealing in hydrogen atmosphere are handled; Car system outer sleeve.
Described manufacturing approach, its said B) step is in hydrogen stove or vacuum furnace, with solder wire with the nickel wire soldering of φ 0.3-0.6mm on the fairlead of the oxygen-free copper substrate of depressed collector electrode, as the lead-in wire of electrode; 10-40 ℃/minute of heating-cooling speed, welding temperature are higher than 10-20 ℃ of indication solder fusing temperature, are incubated 1-5 minute.
Described manufacturing approach, its said C) step, comprise step:
1) according to single-stage buck collector assembling requirement, depressed collector electrode, insulating porcelain piece, outer sleeve are assemblied on the stainless steel mould of handling through melanism successively, lay φ 0.4-0.6mm solder wire in welded joints;
2) put into hydrogen stove or vacuum furnace again, welding temperature is higher than 20-40 ℃ of indication solder fusing temperature, and 10-20 ℃/minute of heating-cooling speed is incubated 1-5 minute, gets one pole collector finished product.
Described manufacturing approach, its said D) step, comprise step:
A) according to the requirement of multi-level depressurization collector integral assembling structure, in mould, with a plurality of through C) one pole collector that step welding is good is assembled into multi-level depressurization collector; B) put into hydrogen stove or vacuum furnace again and weld, welding temperature is higher than 10-20 ℃ of indication solder fusing temperature, and 10-20 ℃/minute of heating-cooling speed is incubated 1-5 minute, gets the multi-level depressurization collector finished product; C) detect, confirm qualified product.
Described manufacturing approach, its said brazing solder silk is pure Ag, Au-Cu or Ag-Cu eutectic solder; The welding vacuum atmosphere, vacuum pressure during for solder fusing<3 * 10
-3Pa.
A kind of carbon of the present invention-oxygen-free copper multi-level depressurization collector and manufacturing approach can be under the condition that does not reduce other performance index improves several percentage points with the gross efficiency of satellite travelling wave tube.
Description of drawings
Fig. 1 is a kind of carbon of the present invention-oxygen-free copper multi-level depressurization collector structural representation; Wherein:
1. insulating porcelain piece; 2. carbon-coating; 3. outer sleeve; 4. contact conductor; 5. oxygen-free copper substrate.
Embodiment
A kind of carbon of the present invention-oxygen-free copper multi-level depressurization collector and manufacturing approach; Be to be electrode basement with the oxygen-free high conductivity type copper material; Adopt ion-plating technique at its surface deposition one deck carbon-coating; Assemble, weld then with through metallized insulating porcelain piece, obtain carbon-oxygen-free copper multi-level depressurization collector assembly.
A kind of carbon of the present invention-oxygen-free copper multi-level depressurization collector electrode:
1. be made up of oxygen-free high conductivity type copper electrode basement and its surperficial carbon-coating, carbon-coating adopts the preparation of vacuum ionic coating technology, thickness 5-15 μ m;
2. adopt the transition of Ti layer between carbon-coating and the oxygen-free copper, to improve adhesion;
3. block with stainless steel retaining tool with the zone (need not to deposit carbon-coating) of insulating porcelain piece welding.
The manufacturing approach of a kind of carbon of the present invention-oxygen-free copper multi-level depressurization collector:
1. wire bonds: in hydrogen stove or vacuum furnace with on Au80Cu20 or the nickel wire soldering oxygen-free copper electrode basement of Ag-Cu eutectic solder with φ 0.3-0.6mm; Lead-in wire as electrode; Hydrogen shield or vacuum atmosphere; 10-40 ℃/minute of heating-cooling speed, welding temperature are higher than 10-20 ℃ of indication solder fusing temperature, are incubated 1-5 minute.
2. assembling and welding
(1) one pole assembling and welding (with reference to figure 1)
A) require carbon-oxygen-free copper electrode, insulating porcelain piece, outer sleeve are assemblied on the stainless steel mould of handling through melanism successively according to package assembly, lay φ 0.4-0.6mm solder wire (Au80Cu20 or Ag-Cu eutectic solder) in welded joints;
B) hydrogen shield or vacuum atmosphere,, 10-20 ℃/minute of heating-cooling speed, welding temperature are higher than 20-40 ℃ of indication solder fusing temperature, are incubated 1-5 minute.
(2) overall package, welding:, will be welded into the collector assembly through the good one pole assembling of step 5 welding according to the requirement of multi-level depressurization collector integral assembling structure.Vacuum welding, 10-20 ℃/minute of heating-cooling speed, welding temperature are higher than 10-20 ℃ of indication solder fusing temperature, are incubated 1-5 minute.
(3) detect, get finished product.
A kind of carbon of the present invention-oxygen-free copper multi-level depressurization collector electrode has utilized the characteristic of the low secondary of graphite type material, has avoided problems such as graphite type material short texture, intensity are low, solderability difference simultaneously again.
Embodiment:
1. process oxygen-free high conductivity type copper collector electrode (level Four) by the design drawing requirement.
2. adopt 1Cr18Ni9Ti stainless steel processing retaining tool, to block the zone (with the welding region of metallization porcelain spare) that need not deposit carbon-coating.
3. will keep off tool and be contained on each electrode, and carry out Ti Plating and handle, and plate carbon then and handle, the carbon-coating THICKNESS CONTROL is at 8-12 μ m.
4. the Au80Cu20 solder wire with two circle φ 0.3 is welded in the nickel wire of φ 0.6mm on the fairlead of oxygen-free copper electrode basement.
5. insulating porcelain piece is selected 95%Al for use
2O
3Pottery, the metallization of welding region high temperature Mo-Mn method, nickel plating, annealing in hydrogen atmosphere reach subsequent use.
6. outer sleeve is formed by the materials processing of no magnetic Monel, wall thickness 0.8mm.
7. erection welding
(1) wire bonds: weld in hydrogen stove or the vacuum furnace, the heating-cooling rate controlled is not more than 35 ℃/minute, welding temperature 900-930 ℃, is incubated 1.5 minutes.
(2) electrode-insulating porcelain piece-outer sleeve welding: the stainless steel mould with melanism positions electrode and outer sleeve, on each weld seam, settles a circle φ 0.6mm Au80Cu20 solder wire.Weld in hydrogen stove or the vacuum furnace, 15-20 ℃/minute of heating-cooling speed, is incubated 1.5 minutes by welding temperature 900-920 ℃.
(3) overall package welding: each utmost point that requires to weld according to package assembly assembles; Lead-in wire passes from the fairlead of insulation porcelain ring; On the cylindrical circumference of two electrode urceolus, load onto a circle φ 0.6mm Ag-Cu eutectic solder silk, weld 15-20 ℃/minute of heating-cooling speed in hydrogen stove or the vacuum furnace; Welding temperature 790-810 ℃, be incubated 1.5 minutes.
Carbon-coating combines well with the oxygen-free copper substrate in the collector of making according to the method described above, and no obvious obscission after high-temperature soldering through Raman spectrum analysis, is the graphite phase in the carbon-coating basically.The structural reliability and the insulation property of multi-level depressurization collector all meet design requirement.