608 results about "Copper substrate" patented technology

The invention relates to a formation method of a lithium-free negative electrode battery, and belongs to the technical field of lithium batteries. The testing method comprises the following steps: standing at low temperature before first-circle charging to enable the interior of the battery to reach a steady state, carrying out short-time and low-electric-quantity charging by adopting large current, and charging and discharging for several circles by adopting small current after the interior of the battery reaches the steady state at room temperature. According to the formation process provided by the invention, a compact seed crystal layer formed by lithium cores can be formed on the surface of Cu in situ at low temperature and high current density, so that the physical binding force between a deposited lithium layer and a copper substrate is remarkably enhanced, and the contact resistance is reduced, thereby inhibiting the growth of moss or dendritic metal lithium and realizing low-porosity and high-compactness lithium deposition; and a more uniform and stable SEI film is formed through low-current deposition, so that the coulombic efficiency and the cycling stability of the battery are improved.

The invention belongs to the field of module parasitic parameter reduction, and discloses a multi-loop decoupling-based low electromagnetic parasitic parameter SiC power semiconductor module, which is characterized in that an independent copper substrate is adopted as an alternating current copper layer to be laminated on a DBC (Direct Bond Copper) ceramic substrate, and a lower tube chip is flipped and then welded on the lower DBC substrate which is disconnected from a radiator; an upper tube chip and a lower tube chip are connected with a copper substrate above through a copper-molybdenum-copper cushion block, and an alternating current output end of the module is suspended above the DBC substrate through the chips and the cushion block. According to the invention, parasitic capacitance of the module AC output end to the grounding radiator can be almost completely eliminated, power-heat transfer loop capacitive decoupling is realized, common-mode current of a SiC device under high-speed switching is significantly reduced, and electromagnetic interference of a high-frequency switching circuit to a driving circuit and a control system is effectively reduced. And meanwhile, the parasitic inductance of the module is remarkably reduced, and orthogonal decoupling of a signal-power loop magnetic flux space is realized.

The invention discloses low-temperature curing silver-coated copper composite slurry and a preparation method thereof. The conductive adhesive comprises the following raw material components in percentage by weight: 60-80% of conductive phase, 2-2.8% of adhesive, 5-10% of resin and 3-8% of additive, and 20%-30% of a solvent. Wherein the conductive phase is formed by compounding spherical silver-coated copper powder and flaky silver powder, and the silver content is reduced and the sheet resistance of the silver-coated copper composite conductive paste is below 25m omega / square through a copper matrix surface silver plating process. A step-by-step mixing technology is adopted in the preparation process, resin and a solvent are dispersed at a high speed at 60 DEG C, then conductive powder is introduced to avoid agglomeration, and a uniform and compact conductive network is finally formed after grinding. After being cured at the low temperature of 130-180 DEG C, the paste has excellent adhesive force and durability, can be applied to the fields of heterojunction solar cells, flexible circuits and the like, and remarkably improves the photoelectric conversion efficiency and the processing adaptability.

The invention provides a preparation method of a copper-clad substrate and the copper-clad substrate. The preparation method comprises the following steps: providing a copper-clad substrate for forming an inner-layer core plate; the copper-clad substrate comprises a copper-clad plate base material and a copper foil arranged on the surface of the copper-clad plate base material; executing an interface modification process on the surface of the copper foil; forming a dry film photoetching film on the surface of the copper foil after interface modification; performing exposure and development processing on the dry film photoetching film to form a dry film photoetching film with a circuit pattern; and the dry film photoetching film is used as a mask to execute an etching process so as to form a circuit pattern on the copper-clad substrate, so that the technical effect of improving the wiring precision is realized.

The invention relates to the technical field of superconducting material processing, in particular to a preparation method of an Nb3Sn superconducting wire. The method mainly comprises the steps that Nb-Zr alloy is loaded into the exterior and / or the center of a Sn-Cu single-core rod, oxide powder is filled between the Nb-Zr alloy and the Sn-Cu single-core rod, then the Sn-Cu single-core rod and the Nb-Zr alloy are loaded into a copper substrate, and Nb3Sn subcomponents are obtained after multi-pass stretching, forming and fixed-length cutting; and uniformly arranging the Nb3Sn sub-components in the copper pipe along the circumferential direction to form a bundle, and after multi-pass stretching, carrying out heat treatment and cutting to obtain the Nb3Sn superconducting wire. By introducing the artificial point pinning array in density gradient distribution, the critical current density of the Nb3Sn superconducting wire in a high magnetic field of 8T-16T is enhanced, the problems that an existing uniform artificial point pinning center scheme generates a matching effect and limits the actual application of the superconducting wire are solved, and the decline degree of the critical current density of the Nb3Sn superconducting wire in the high field is relieved.

The invention relates to a method for constructing a composite super-hydrophobic coating through double bonding. The preparation method comprises the following steps: taking a clean copper sheet which is not pretreated as a substrate, dipping the copper sheet in a suspension consisting of nanoparticles and sulfydryl-containing siloxane ethanol, taking out, washing, drying, dipping in a perfluoromercaptan ethanol solution, taking out, washing, and drying to obtain the copper-based super-hydrophobic surface coating. The coating prepared by the method has excellent super-hydrophobicity, icing resistance and stability. Different from an existing conventional preparation method, the method has the advantages that pretreatment operation such as abrasive paper polishing, strong acid etching or anodic oxidation does not need to be carried out on a copper sheet, and micro-nano roughening and low-surface-energy self-assembly can be completed on the copper surface only through two-step normal-temperature dipping. The method is simple in preparation process, mild in condition, free of expensive equipment, thin in coating thickness and small in influence on electric conduction and heat conduction of the copper substrate, intrinsic performance of copper can be reserved, the electric conduction / heat conduction characteristic of the copper substrate is considered, and the method has wide application value and prospects.

The invention discloses a composite two-phase flow micro-channel radiator for high-density heat flow, and belongs to the technical field of heat dissipation, the composite two-phase flow micro-channel radiator for high-density heat flow comprises a vapor chamber for heat transfer, a manifold copper substrate is arranged on the vapor chamber, a diversion trench is formed in the bottom surface of the manifold copper substrate, a liquid inlet is formed in one side surface of the manifold copper substrate, and the liquid inlet is communicated with the diversion trench; a flow guide groove is formed in one side face of the manifold copper substrate, a liquid outlet is formed in the other side face of the manifold copper substrate and communicated with the flow guide groove, protruding strips are arranged on the temperature equalizing plate and arranged in the flow guide groove, a liquid conveying groove is formed between every two adjacent protruding strips, a first cavity is formed in the temperature equalizing plate, a second cavity is formed in each protruding strip, and the first cavity is communicated with the second cavity. The heat dissipation device has the advantages that heat rapidly increased in unit area of equipment can be timely and effectively dissipated, and the overall heat dissipation efficiency and the heat dissipation effect are improved.

The invention discloses a method for chemically plating silver on the surface of a nickel-plated ceramic copper-clad substrate, and relates to the technical field of metal surface treatment. The preparation method comprises the following steps: S1, sequentially adding nitric acid, imidazole and a surfactant into deionized water, and uniformly mixing to obtain an activating agent; s2, after the ceramic copper-clad substrate is pretreated, chemical nickel plating treatment is carried out, cleaning and drying are carried out, and a nickel-plated ceramic substrate is obtained; and S3, the nickel-plated ceramic substrate is immersed in an activating agent for activating treatment, chemical silver plating treatment and post-treatment are conducted, and a product is obtained. According to the method provided by the invention, the problem of copper ion migration in the later silver welding process of chemical silver plating on the surface of the ceramic copper-clad substrate can be solved, and the performance of the packaging module is improved.

The invention discloses a low-temperature and low-pressure connection method for copper surface in-situ nanocrystallization, and relates to a copper connection method. The method aims at solving the technical problems that operation of current copper sintering connection is complex, an intermediate layer needs to be added for assistance, the connection strength is low, the interface welding rate is low, the connection temperature and pressure are too high, and the heat preservation time is long. The nanolayer is prepared on the surface of the copper substrate by adopting an in-situ nanocrystallization method, the nanostructure has relatively large surface energy, sintering connection can be realized at low temperature and low pressure, a high-strength joint is formed, and the method can be applied to the fields of copper connection, electronic packaging and the like. And under the condition of 125 DEG C / 10min / 5MPa, the shear strength of the obtained joint can reach 118.9 MPa without additionally adding a nano-particle sintering middle layer, and a connection structure with low connection temperature, short time, low required pressure and high mechanical stability is realized. The method is simple and effective to operate, can realize low-temperature connection of large-size samples, and has a wide application prospect.

According to the printed circuit board and the manufacturing method for the same-layer local multiple-copper-thickness circuit pattern of the printed circuit board, the same-layer high-frequency signal circuit on the printed circuit board is patterned step by step, and the multiple-copper-thickness circuit is accurately constructed in the same circuit layer in combination with the two-time pattern electroplating process and the voltage conversion process. Specifically, a layer of surface copper foil is additionally covered on the surface of the copper foil of the copper-clad substrate to form a voltage-transferring substrate, the surface copper foil is used as a connecting layer between a first circuit layer and a second circuit layer, and two surfaces of the surface copper foil are independently electroplated twice, so that the copper thickness distribution of different circuit areas is accurately controlled, and the voltage-transferring effect is improved. And finally, a plurality of signal circuit patterns with coexisting copper thicknesses are constructed in the surface copper layer on the inner-layer voltage conversion substrate, so that the fineness and reliability of the signal circuit are ensured to meet the high-frequency signal transmission requirement, the layout flexibility of the signal circuit on the printed circuit board is improved, the impedance matching of the signal circuit is ensured, and the signal loss is reduced at the same time.

The invention belongs to the technical field of laser cladding processing, and provides a method for preparing an ablation-resistant copper alloy through a blue laser cladding process and the ablation-resistant copper alloy. The method comprises the following steps that alloy powder is subjected to ball milling, and mixed powder is obtained; the alloy powder is CuCr powder, CuW powder, ODS-Cu powder, SiO2 / Cu powder or C / Cu powder; and the mixed powder is used for preparing a cladding layer on a copper base material by adopting a blue laser cladding process. According to the method, the characteristic that a copper material is high in blue laser absorptivity is utilized, the problems of heat input accumulation, air holes, inclusions and the like under the conditions of low absorptivity and high energy density are avoided, and laser process parameters are controlled to form a molten pool on the surface of a copper base material; and the coaxial powder feeding device gathers the powder material into the molten pool for melting and rapid cooling and solidification by utilizing protective gas to form a cladding layer with excellent performance, so that the surface of the copper base material is modified, and the performance of the copper base material is improved.

The invention provides a packaging structure and a packaging method for improving the heat dissipation performance of an IGBT power module. The packaging structure comprises a copper substrate, a first epoxy glue layer, an epoxy resin-based composite material layer, a second epoxy glue layer, an upper bridge copper layer, a lower bridge copper layer, a chip solder layer and a power chip which are sequentially arranged from bottom to top, wherein the upper bridge copper layer and the lower bridge copper layer are integrally arranged; the power chip comprises an upper bridge chip and a lower bridge chip; the chip solder layer comprises an upper bridge chip solder layer and a lower bridge chip solder layer; the upper bridge chip solder layer is arranged on the upper bridge copper layer, and the upper bridge chip is arranged on the upper bridge chip solder layer; the lower bridge chip solder layer is arranged on the lower bridge copper layer, and the lower bridge chip is arranged on the lower bridge chip solder layer. According to the packaging structure, the epoxy resin-based composite material layer is adopted as the insulating layer, copper and a welding layer are reduced in heat flow transmission, the heat resistance from the chip to the shell is reduced, and the heat dissipation performance is improved; the copper layers of the upper and lower bridge arms are integrated, leads between the upper and lower bridges are reduced, the power loss of the IGBT is reduced, and the heat is reduced.

The invention relates to a copper substrate embedding method for separated special-shaped copper blocks and a circuit board, and the method comprises the following steps: processing a plurality of special-shaped copper blocks with preset shapes on a copper plate, and reserving a plurality of connecting ribs which are not completely cut off between the adjacent special-shaped copper blocks; a gap between every two adjacent special-shaped copper blocks is filled with resin; a heat-conducting insulating layer and a copper foil are sequentially overlaid on the two opposite faces of the copper plate to form a stacked structure, and a substrate is formed through high-temperature pressing; an isolation groove is formed in the position, corresponding to the connecting rib, of the substrate, and the isolation groove cuts off the connecting rib; the isolation groove is filled with resin, and the resin overflowing out of the plate surface is rubbed down; and conducting treatment: forming a continuous conductive copper layer on the surface of the resin filling area. According to the invention, no copper groove needs to be buried, the copper block can be processed into a specific shape, and the distance between two adjacent special-shaped copper blocks is controlled to be 1.0 mm, so that the number and the area of the copper blocks buried in the substrate are greatly increased, and the heat dissipation performance and the electrical performance of the circuit board are improved.

The invention discloses a method for reducing grafting printing deformation of a plate-shaped copper alloy part, and belongs to the technical field of grafting printing. The printing method comprises the following steps: processing countersunk head screw holes in a pure copper substrate (avoiding a printing area), and locking the countersunk head screw holes to a printing bottom plate by using screws; printing parameters are as follows: the slice layer thickness is 0.03 mm, the laser power is 180-220 W, the scanning speed is 950-1050 mm / s, checkerboard scanning is performed, and interlayer cooling is performed for 10-20 s; during powder laying and printing, first-layer remelting is carried out to enhance combination; annealing treatment: keeping the temperature at 600 DEG C for 2 hours, and then cooling; and finally, the screws are taken down to obtain the low-deformation plate-shaped part. The thermal expansion coefficient difference between the copper alloy and the pure copper substrate is improved through the specific copper alloy material, the deformation risk is avoided, and the good heat-conducting property and mechanical property of the product can be guaranteed; and secondly, in combination with a printing process, residual stress is reduced.

The invention discloses a green laser assembly, an optical module and application of the green laser assembly in photovoltaic assembly processing, a shell is provided with a first fixed reflector coated with a reflecting film for reflecting 1064nm, a first acousto-optic Q switch and a second acousto-optic Q switch are orthogonally arranged, an Nd: YAG laser uses an Nd: YAG crystal rod with the diameter of 6mm and the length of 166mm, and a second fixed reflector coated with a reflecting film for reflecting 1064nm is arranged on the Nd: YAG crystal rod. The first dichroscope transmits 1064nm and reflects 532nm to improve the conversion efficiency of frequency multiplication, the LBO crystal 16 is placed close to the second dichroscope to improve the power density and the conversion efficiency, and the second dichroscope reflects 1064nm and transmits 532nm. And the light with the wavelength of 532nm transmitted by the second dichroscope is coupled into an input end optical fiber of the optical fiber beam splitter after passing through the optical isolator and the first lens. The short-wavelength green laser is adopted, the photovoltaic welding strip is mainly composed of the copper base material and the tin alloy, the green laser absorptivity is far larger than the near-infrared wavelength (about 1 micron) absorptivity, and the laser absorptivity of the welding strip is remarkably improved.

The invention discloses a grafting 3D printing method for improving the binding force of a copper substrate and a copper grafting piece and application of the grafting 3D printing method, and belongs to the technical field of grafting printing. The grafting 3D printing method for improving the binding force of the copper substrate and the copper grafting piece is characterized in that the copper substrate is subjected to roughening treatment before printing, and abrasive materials are sprayed at the angle of 30-60 degrees through automatic sand blasting equipment, so that uniform tiny pits (concave-convex structures) with certain depth are formed in the surface of the copper substrate; during control printing, D0 layer entity scanning is conducted twice, and contour scanning is conducted three times; the D1 layer entity is scanned once, and the contour is scanned twice; the contour and entity of the D2 layer and the subsequent printing layer are scanned once respectively, so that the binding force of a grafting printing interface is greatly improved, in a vertical drawing test, it is guaranteed that the fracture position is not located on the grafting interface, and the stability of a printed product and the durability of the printed product in coping with various application scenes are guaranteed.

The invention discloses a high-hardness high-thermal-conductivity gradient structure copper material which is composed of a base body and a surface layer combined on the surface of the base body, the base body is oxygen-free copper, and the surface layer is a copper boron nitride alloy composed of two phases of copper grains and a boron nitride film. The surface layer and the base body are metallurgically bonded; the boron nitride thin film in the copper boron nitride alloy is clamped between copper crystal grains to form a gradient distribution structure which is in a net shape to separate and wrap the copper crystal grains, and the boron nitride content of the gradient distribution structure is continuously reduced from the outside to the inside. The invention further discloses a preparation method of the copper material, oxygen-free copper serves as a substrate to form a base body in the copper material, copper-boron alloy with boron components distributed in a gradient mode is prepared on the surface of the oxygen-free copper substrate through laser additive manufacturing, then the copper-boron alloy on the surface of the oxygen-free copper is nitrided into copper-boron nitride alloy through nitriding treatment, and then the surface layer of the copper material is formed. And the composite copper material with high hardness and high thermal conductivity is obtained. The prepared copper material can meet the service requirements of the heat management industry on the wear resistance and the heat dissipation performance of components at the same time.

The invention belongs to the technical field of electro-catalysis carbon dioxide reduction, and particularly relates to a three-dimensional porous copper oxide-zinc bimetallic film electrode for electro-reduction of carbon dioxide and preparation and application of the three-dimensional porous copper oxide-zinc bimetallic film electrode. The preparation method comprises the following steps: firstly, carrying out surface pretreatment on a copper substrate, then carrying out pulse current electrodeposition and dynamic etching on the surface of an electrode in a mixed electrolyte containing zinc salt, copper salt and sodium salt, and finally, carrying out constant current structure reconstruction on the electrode by adopting a long-time reduction method to prepare the three-dimensional porous copper oxide-zinc bimetallic film electrode. The electrode has a unique nano pore channel structure, rapid transfer of interface charges is promoted, and the electrode has rich active sites due to the synergistic effect of a heterostructure. The preparation method has the dynamic regulation and control advantage of pulse deposition and the structural stability of constant-current deposition, a template agent does not need to be added in the preparation process, and the process controllability is high. The obtained electrode shows excellent CO product selectivity, activity and stability in an electro-catalysis carbon dioxide reduction reaction.

The invention is suitable for the technical field of heat pipe experiment systems, and provides a heat pipe experiment system and method based on visual visualization and dual-seal temperature control, and the system comprises a visual heat pipe, a temperature adjustment module, a data collection module, a liquid injection module and a glass temperature monitoring feedback module. The visual heat pipe adopts an aluminum alloy cover plate, visual glass and a copper substrate to form a double-sealing structure. The system integrates a glass temperature monitoring and feedback mechanism, prevents the observation window from fogging, prevents the temperature of the observation window from being too high, and guarantees high-definition visual observation. And the data acquisition module synchronously records the thermal parameters and the dynamic image of the condensed liquid drop, and quantitatively analyzes the behavior of the liquid drop through an image processing technology. The system can realize high-definition observation, high-precision temperature control and quantitative analysis of the internal condensation process of the flat heat pipe at different inclination angles and under different working conditions, and is suitable for in-depth research of a phase-change heat exchange mechanism and heat pipe performance.

The invention relates to the technical field of composite metal materials, in particular to a silver-coated graphene copper composite material and a preparation method thereof, and aims at solving the problems that traditional silver-coated copper powder is high in silver consumption, copper is oxidized due to the fact that a silver layer is prone to being damaged, and conductivity is insufficient. The method comprises the steps that a graphene coating layer is formed on a copper powder substrate in situ through chemical vapor deposition, and graphene copper powder is obtained; performing etching treatment on the graphene copper powder to controllably expose part of the copper substrate so as to form anchoring points for silver ion deposition; carrying out reduction treatment on the etched graphene copper powder so as to ensure that an anchoring site has chemical activity; in a reductive liquid phase environment, enabling a chemical silver plating solution to react with the graphene copper powder subjected to reduction treatment, and guiding silver ion deposition by utilizing an anchoring point, so as to form a silver coating layer on the surface of the graphene coating layer; and separating and drying the reacted system to obtain the silver-coated graphene copper composite material. The material is better in oxidation resistance and conductivity, and the process is free of waste liquid.

The invention discloses a subtractive etching micro-nano multistage rough structure copper surface for strengthening boiling heat transfer and a preparation method thereof, and relates to the technical field of micro-nano composite structure strengthening phase change heat transfer. The etched micro-nano multistage coarse structure completely covers the surface of the copper substrate, the micro-nano multistage coarse structure comprises micron-scale concave cavities, nano-scale concave cavities / holes and nano-scale granular bulges, and the micron-scale concave cavities, the nano-scale concave cavities / holes and the nano-scale granular bulges jointly form a multistage structure; performing ultrasonic cleaning on the target metal substrate by using a cleaning solution; and a mixed aqueous solution of ammonium persulfate and chlorate is used as an etching solution, and the cleaned target metal substrate is left to stand in the etching solution for etching. And after the etching is finished, cleaning to obtain the etched micro-nano composite rough structure surface. Ammonium persulfate and chlorate are used as solutes, and the mass ratio of the solutes to the solvent is 1: 3. The mass ratio of the ammonium persulfate to the chlorate in the solute is (1: 9)-(3: 7). The method has high production efficiency, shows good thermal stability in a boiling test, and is beneficial to industrial large-scale application and production.

The invention relates to the technical field of copper substrate feeding equipment, in particular to a multilayer thermoelectric separation copper substrate production processing feeding device which comprises a feeding table, a supporting frame fixed to the top end of the feeding table and a storage table fixed to the top end of the supporting frame. A suction cup mechanical arm is fixedly installed on one side of the top end of the conveyor, a containing base is arranged in the bottom end of the storage table, and two disassembling assemblies are arranged on the side edge of the storage table, so that when the multi-layer thermoelectric separation copper substrate producing, machining and feeding device is used, the multiple layers of thermoelectric separation copper substrates are separated; the multiple copper substrates stacked at the top end of the containing base can be sequentially limited, lifted and separated, so that oil film adhesion is effectively broken, each multi-layer thermoelectric separation copper substrate is independently placed in a suspended mode, subsequent precise adsorption of a suction cup mechanical arm is facilitated, feeding faults are solved, the situation that two or more copper substrates are fed at a time is avoided, and the production efficiency is improved. And therefore, the overall feeding stability and the production efficiency are improved.

The invention provides a multi-channel high-precision resistance temperature coefficient test system and method, and the system comprises a vacuum system module which is used for a vacuum test environment, a temperature control heating module which is a heating device with programmable temperature control, and a multi-channel test module which comprises a resistance tester, a multi-channel acquisition card and a connection interface, the multi-channel acquisition card is connected with the resistance tester through an interface, the multi-channel acquisition card is connected with the aviation plug through a test line, the aviation plug is detachably connected with a sample to be tested through the test line, and the temperature monitoring module adopts a thermocouple to test temperature. The data acquisition terminal records and processes multichannel resistance values and corresponding temperature data in real time, the sample table module is used for placing multichannel test samples and is placed in the temperature control heating module, and a sample table adopts an aluminum-based PCB (printed circuit board) or a copper-based PCB subjected to aluminum nitride ceramic or insulation treatment and can bear at least two test samples at the same time.

A power device electronics system includes a thermal management configuration in which a power electronics chip is attached to a copper substrate and a single crystal diamond substrate attached to the copper substrate. The copper substrate is sandwiched between a first side of the diamond substrate and the power electronics chip.

The utility model belongs to the technical field of automobile motor controllers, and particularly relates to a silicon carbide module packaging structure, a motor controller and an automobile. According to the silicon carbide module packaging structure, the first active metal welding ceramic substrate is arranged on the upper side of the silicon carbide module, and the second active metal welding ceramic substrate is arranged on the lower side of the silicon carbide module; wherein the first active metal welding ceramic substrate and the second active metal welding ceramic substrate can be directly sintered through an active brazing process and then are directly arranged in the silicon carbide module through a simple filling process and the like, namely, the similar thermal process modes such as heat-conducting glue or solder welding when a copper substrate is arranged are not needed; therefore, the process installation requirement is reduced; meanwhile, the water cooling unit is further arranged, heat dissipation can be conducted on the heat conduction part on the lower side, and therefore the heat dissipation amount of the silicon carbide module is increased.

The invention discloses a double-frequency constant-temperature crystal oscillator and a manufacturing method thereof, and relates to the technical field of crystal oscillators, and the double-frequency constant-temperature crystal oscillator comprises a ceramic base and a ceramic bottom plate which are integrally formed by adopting an LTCC (Low Temperature Co-Fired Ceramic) process; the high-frequency quartz crystal and the low-frequency quartz crystal are respectively arranged in independent closed cavities, and unified heating and accurate temperature control are realized through the high-heat-conduction diamond copper substrate, the metalized heat conduction holes and the partitioned temperature sensing chips; the two paths of signals are output through independent interconnection paths, and the crosstalk is lower than-50dBm. According to the invention, the dual-frequency high-stability low-noise output is realized under the similar volume, and the requirements of a flight control system on a high-integration-level and high-reliability frequency source are met.

The invention discloses three-layer porous graphene and a preparation method thereof, and belongs to the field of nano materials. The preparation method of the three-layer porous graphene comprises the following steps: growing graphene on a copper substrate by adopting a chemical vapor deposition method to obtain the three-layer porous graphene, wherein hydrogen, shielding gas, methane and oxygen-containing gas or pure oxygen are introduced in the chemical vapor deposition process; the growth temperature of the chemical vapor deposition enables the copper substrate to be molten into a liquid state. Compared with the traditional method, the method provided by the invention does not need complex manpower and material resources, does not need special treatment on the substrate, and provides a method capable of realizing more efficient growth of the three-layer porous single crystal graphene.

The invention relates to the technical field of microwave plasma chemical vapor deposition, in particular to MPCVD equipment and a preparation method for preparing a large-size polycrystalline diamond film, a quartz ring is arranged in a reaction chamber, a water-cooled copper substrate table is arranged at the top of the quartz ring, a molybdenum ring is arranged at the top of the water-cooled copper substrate table, and a water-cooled copper-based sample table is arranged in the center of the molybdenum ring; the bottom of the water-cooled copper-based sample table is connected with a lifting pipe, the top of the water-cooled copper-based sample table is provided with a molybdenum support, and the top of the molybdenum support is provided with a sample ring; two infrared temperature measurement sensors are arranged outside a temperature measurement observation window of the reaction chamber and are respectively aligned with the edge and the central area of the sample ring; a copper-based sample table cooling water path and a thermal resistance wire are arranged in the water-cooled copper-based sample table in a staggered manner, the thermal resistance wire is electrically connected with the electric heating control device, and the electric heating control device is electrically connected with the double-infrared temperature measuring device. According to the method, the temperature uniformity of the inner and outer areas in the large-size polycrystalline diamond film deposition process can be improved.

The invention discloses an accelerator neutron source solid-state lithium target cooling device, and relates to the technical field of accelerator neutron source medical application. An annular heat pipe is arranged on the outer ring of the side portion of an oxygen-free copper substrate, a plurality of liquid absorption cores are arranged on the inner wall of the heat pipe, and meanwhile an inner cavity of the heat pipe is filled with a working medium; when heat is generated, the heat is firstly transferred to the oxygen-free copper substrate, the evaporation section of the heat pipe is heated, the working medium in the wick is quickly evaporated and gasified, the generated steam flows to the condensation section under the driving of differential pressure and is condensed into liquid in the condensation section and releases heat, and the liquid generated by condensation returns to the evaporation section again under the capillary action of the wick. The space of the arranged heat pipe is large, and in the aspect of heat dissipation, the working medium is subjected to gas-liquid phase change in the heat pipe under the action of the liquid absorption core, so that the accelerator is rapidly dissipated, heat on the solid target material film can be rapidly taken away, and the cooling effect on the accelerator is greatly improved.

The invention discloses a porous copper-graphene composite current collector for a lithium battery, and also discloses a preparation method of the composite current collector, and the preparation method comprises the following steps: preparing an electroplating copper electrolyte, adding graphene into the electroplating copper electrolyte, and uniformly dispersing the graphene to obtain an electroplating copper-graphene electrolyte; placing a copper foil in the electrocoppering-graphene electrolyte for electroplating treatment to obtain a Cu-Gr foil of which the surface is uniformly coated with a copper-graphene composite layer; the Cu-Gr foil is placed in an electrogalvanizing electrolyte for electrogalvanizing treatment, on the basis of the copper-graphene composite layer, a zinc layer is coated, and the Cu-Gr / Zn foil of a double-layer structure is obtained; carrying out solution treatment on the Cu-Gr / Zn foil to obtain a porous copper precursor; and carrying out dealloying treatment on the porous copper precursor, and dissolving zinc in the porous copper precursor to obtain the porous copper-graphene composite current collector. The composite current collector has a cross-scale synergistic distribution pore structure, and the binding force between the graphene and the copper substrate is strong.