33results about How to "Improve longitudinal thermal conductivity" patented technology

The invention discloses a graphite composite heat sink and a preparation method thereof. The preparation method of the graphite composite heat sink comprises the following steps: depositing a metal material on the surface of the graphite sheet to form a metal coating; stacking a plurality of graphite sheets with the metal coating to obtain A laminated body; rolling the laminated body with a hot pressing roller. There is no adhesive inside the graphite composite heat sink prepared by the graphite composite heat sink preparation method, and the adjacent two layers of graphite sheets are connected by thermocompression using the low-melting point metal coating on the surface to achieve the purpose of obtaining a thicker graphite composite heat sink. Maintaining the heat conduction advantage of the graphite composite heat sink in the horizontal direction can increase the longitudinal heat conduction performance of the graphite composite heat sink, so that the graphite composite heat sink has an excellent heat conduction effect, and the preparation process of the graphite composite heat sink is simple and low in cost.

The invention relates to a method for preparing oriented assembled graphene, which comprises: mixing an aqueous solution of graphene oxide and a water-soluble metal salt, then slowly cooling down until water molecules crystallize into ice, and then freeze-drying to obtain oriented Graphene oxide is assembled, and after reduction, oriented assembled graphene loaded with metal nanoparticles is obtained. The oriented assembled graphene has a three-dimensional layered structure in which layers are arranged in parallel, and interlayer gaps exist between the layers, and metal nanoparticles are riveted in the three-dimensional layered structure of the oriented assembled graphene. The present application also relates to directionally assembled graphene prepared by the method described above. The present application also relates to a graphene-carbon nanotube composite heat-conducting film prepared by using the above-mentioned directional assembled graphene and a preparation method thereof. The composite thermal conductive film described in this paper has the advantages of low cost, high phase orientation of graphene, ultra-high thermal conductivity, and controllable thickness of ultra-high flexibility products. The vertical thermal conductivity can reach up to about 100W / (m·K).

The invention discloses a preparation method of a graphite airgel-based composite thermal interface material with high thermal conductivity, relating to the thermal interface material. The method comprises the following steps: adding ascorbic acid into deionized water, stirring to obtain a uniform ascorbic acid solution; stirring and adding GO aqueous solution, transferring the obtained mixed solution to the lining of the reaction kettle, sealing it and putting it into a stainless steel shell, and placing it in a blast drying oven Reaction; the reaction product is transferred from the reactor lining to other containers, and washed repeatedly with deionized and ethanol; the cleaned sample is frozen, and then transferred to a freeze dryer for drying; the sample is placed in a mold, and the sample is compressed with a certain pressure , and then pour the prepared polymer solution into the mold; place it in a vacuum drying oven to dry; the dried sample is demolded from the mold to obtain a high thermal conductivity graphite airgel-based composite thermal interface material. With high longitudinal thermal conductivity, good mechanical properties, self-supporting and easy storage, it is expected to solve the bottleneck problem of heat dissipation in electronic products.

The invention provides an anisotropic composite material for a spaceborne radar antenna panel, and a preparation method thereof, and relates to a composite material for a spaceborne radar antenna panel, and a preparation method thereof. In the prior art, the existing composite material for spaceborne radar antenna panels can not concurrently meet a transverse tensile strength and longitudinal tensile strength, and has characteristics of poor comprehensive mechanical property and not high density. A purpose of the present invention is to solve problems in the prior art. The composite material is prepared from 60-80% by mass of an asphalt base graphite fiber reinforcement body, 4-6% by mass of aluminum nitride particles, and the balance of a matrix aluminum alloy. The preparation method comprises: coating an aluminum nitride suspension on the surface of fibers, fixing into a bundle, injecting an aluminum alloy solution to impregnate, and spraying a cooling liquid to rapidly cool to obtain the composite material. The anisotropic composite material has characteristics of high density, high longitudinal tensile strength maintaining, high longitudinal thermal conductivity maintaining, transverse tensile strength increase, transverse thermal conductivity increase, and excellent comprehensive performance, and can be used in the field of spaceborne radar antenna panels and preparations thereof.

The invention provides a flexible circuit board and a mobile terminal. The flexible circuit board comprises at least one flexible circuit layer. Each flexible circuit layer includes an insulated substrate; a first conductive plate covers the first surface of the insulated substrate; and a first line is arranged on the first conductive plate. A first conduction slot is formed at the position, corresponding to the first line, of the first conductive plate and penetrates the first conductive plate in a thickness direction of the first conductive plate. A second conduction slot is formed at the position, corresponding to the first conduction slot, of the insulated substrate; the second conduction slot and the first conduction slot are communicated; and the second conduction slot penetrates the insulated substrate in the thickness direction of the insulated substrate. And the first conduction slot and the second conduction slot are filled with conducting media. According to the flexible circuit board provided by the invention, the conduction slots are formed in the insulated substrate and are filled with the conducting media, so that the heat generated by the line of the flexible circuit board is transmitted rapidly and vertically by the conducting media. Therefore, the vertical heat conductivity coefficient of the flexible circuit board is increased.

The invention discloses a graphene heat dissipation coating, which comprises the following components in parts by weight: polymer resin: 40-80 parts; graphene: 5-15 parts; one-dimensional carbon nanomaterial: 1-8 parts; heat conduction Metal powder: 1-8 parts; Dispersant: 0.5-5 parts; Defoamer: 0.5-5 parts; Inert solvent: 100-200 parts; The heat-conducting metal powder is at least selected from silver powder, copper powder and aluminum powder One, and the particle size is 1‑20 μm, the above-mentioned coating has good heat dissipation and heat conduction function. The invention also discloses the preparation method of the graphene heat-dissipating coating, which mainly includes stirring, grinding and remixing processes, and has simple operation and low cost. The above-mentioned graphene heat dissipation coating is mainly used in the heat dissipation of daily electronic products because of its good heat conduction and heat dissipation functions, and can also be used in aerospace electronic devices with higher requirements.

The invention relates to the technical field of graphene, and relates to a preparation process of a graphene oxide three-dimensional self-assembled plate, comprising the following steps: (1) using hummers to prepare a graphene oxide filter cake; (2) adding deionized water so that its solid content is 1%‑5%, adjust the pH value to 3.0‑4.0; (3) Add urea-formaldehyde resin with a low degree of polymerization to make a graphene oxide composite slurry; (4) Coat the graphene oxide composite slurry on the substrate ;(5) at 50‑70 o Dry at C temperature; (6) Laminate 5‑7 sheets of graphene oxide film (7) at a vacuum degree of ‑60Kpa to ‑100Kpa and a temperature of 100 o C‑200 o Under the condition of C, pressurize at 1‑5MPa, let it stand for 0.5‑1h; (8) under the condition of argon, pressurize at 5‑10MPa, and raise the temperature to 800 o C‑1200 o C, stand still for 1‑2h; (9) in argon state, heat up to 2000‑2500 oC , stand still for 2-3h, complete the graphitization treatment, and make a graphene plate; the invention is simple and easy to implement, and has high practicability.

The invention belongs to the technical field of polymer composite materials, and discloses a preparation method and product of a directional interconnected high thermal conductivity interface material. The method includes the following steps: S1 adding filler particles into a mold, placing the mold in a permanent magnetic field, and applying vibration to the mold, so that the filler particles are automatically aligned and arranged in the magnetic field under vibration , forming an array of filling particles; S2 maintaining the permanent magnetic field, injecting thermosetting polymer colloid into the mold, and vacuuming the mold to remove the air therein, so that the thermosetting polymer colloid is filled into the filling particle array In the gap, the temperature rises and solidifies, so as to obtain the desired directional interconnected high thermal conductivity interface material. The present application also discloses the product obtained by the above preparation method. The present invention has excellent thermal conductivity, good mechanical strength and processability.

The invention provides an organosilicon-graphite composite thermal interface material and its preparation method and application. The organosilicon-graphite composite thermal interface material comprises a graphite skeleton with a honeycomb structure and an organosilicon material filled in the honeycomb structure. The thermal interface material of the present invention includes organosilicon and honeycomb graphite skeleton, which not only retains the soft fit of organosilicon but also has good thermal conductivity of graphite skeleton, and the organosilicon material is filled in the honeycomb structure of graphite skeleton, making the present invention The thermal interface material has higher longitudinal thermal conductivity at a lower packing density, and the honeycomb structure can further improve the tensile strength of the silicone material and prolong the service life in harsh environments.