# US 2014/0190676 A1 · Unitary graphene material-based integrated finned heat sink > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190676 A1 - Document ID: US20140190676A1 - Status: Published application - Kind: A1 - Application number: 13/694,791 - Filed: 2013-01-07 - Published: 2014-07-10 - Earliest claimed: 2013-01-07 - Assignees: Nanotek Instruments, Inc. - Inventors: Aruna Zhamu; Mingchao Wang; Wei Xiong; Bor Z. Jang; Lin Yi-jun - Web page: https://patentgrep.com/patent/US20140190676A1 ## CPC - F28F 21/02: of carbon, e.g. graphite - C09K 5/14: Solid materials, e.g. powdery or granular - F28D 2021/0029: {Heat sinks} - F28F 21/00: Constructions of heat-exchange apparatus characterised by the selection of particular materials {(coatings for modifying heat-transfer F28F13/18; coatings for preventing the formation of deposits or corrosion F28F19/02)} - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) - C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE - F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general) ## Abstract A unitary graphene-based integrated heat sink comprising a heat collection member (base) and at least one heat dissipation member (e.g. fins) integral to the baser, wherein the base is configured to be in thermal contact with a heat source, collects heat therefrom, and dissipates heat through the fins. The unitary graphene material is obtained from heat-treating a graphene oxide gel at a temperature higher than 100° C., 500° C., 1,250° C., or 2,000° C., and contains chemically bonded graphene molecules having inter-graphene distance of 0.3354-0.4 nm (preferably <0.337 nm). The unitary graphene material is a graphene single crystal, a poly-crystal with incomplete grain boundaries, or a poly-crystal having large grain sizes (e.g. >mm or cm), exhibiting a degree of graphitization preferably from 1% to 100% and a Mosaic spread value less than 0.7 (preferably no greater than 0.4). The finned heat sink may also be made from a filler-reinforced graphene matrix composite. ## Claims ### Claim 1 An integrated heat sink comprising a unitary graphene material article composed of a heat collection member and at least one heat dissipation member integral to said heat collection member, wherein the heat collection member is configured to be in thermal contact with a heat source, collects heat from said heat source, and dissipates heat through the at least one heat dissipation member, and further wherein the unitary graphene material is obtained from heat-treating a graphene oxide gel at a heat treatment temperature higher than 100° C. and contains chemically bonded graphene molecules or chemically merged graphene planes having an inter-graphene spacing no greater than 0.40 nm. ### Claim 2 (depends on 1) The integrated heat sink of claim 1, wherein the unitary graphene material further contains a discrete filler or reinforcement phase dispersed in said unitary graphene material to form a unitary graphene matrix composite structure and said filler or reinforcement phase contains a particle, filament, nano-tube, nano-wire, or nano-rod of a metal, ceramic, glass, polymer, carbon, graphite, or a combination thereof. ### Claim 3 (depends on 1) The integrated heat sink of claim 1, wherein the unitary graphene material further contains a discrete solid carbon, graphite, or graphene filler phase dispersed in said unitary graphene material to form a unitary graphene matrix composite structure and said filler phase is selected from a carbon or graphite fiber, carbon or graphite nano-fiber, carbon nano-tube, carbon nano-rod, meso-phase carbon particle, meso-carbon micro-bead, expanded graphite flake with a thickness greater than 100 nm, single-layer graphene sheet, multi-layer graphene platelet with a thickness less than 100 nm, exfoliated graphite or graphite worm, coke particle, needle coke, carbon black or acetylene black particle, activated carbon particle, or a combination thereof; wherein said carbon, graphite, or graphene filler phase occupies a weight fraction of 0.01% to 99% based on the total composite structure weight. ### Claim 4 (depends on 1) The integrated heat sink of claim 1, wherein said heat treatment temperature contains a temperature in a thermal reduction regime of 100° C.-500° C. and the unitary graphene material has an oxygen content less than 5%, an inter-graphene spacing less than 0.4 nm, and/or a thermal conductivity of at least 100 W/mK. ### Claim 5 (depends on 1) The integrated heat sink of claim 1, wherein said heat treatment temperature contains a temperature in the range of 500° C.-1,250° C. and the unitary graphene material has an oxygen content less than 1%, an inter-graphene spacing less than 0.345 nm, a thermal conductivity of at least 1,300 W/mK, and/or an electrical conductivity no less than 3,000 S/cm. ### Claim 6 (depends on 1) The integrated heat sink of claim 1, wherein said heat treatment temperature contains a temperature in the range of 1,250° C.-2,000° C. and the unitary graphene material has an oxygen content less than 0.01%, an inter-graphene spacing less than 0.337 nm, a thermal conductivity of at least 1,500 W/mK, and/or an electrical conductivity no less than 5,000 S/cm. ### Claim 7 (depends on 1) The integrated heat sink of claim 1, wherein said heat treatment temperature contains a temperature greater than 2,000° C. and the unitary graphene material has an oxygen content less than 0.001%, an inter-graphene spacing less than 0.336 nm, a mosaic spread value no greater than 0.7, a thermal conductivity of at least 1,700 W/mK, and/or an electrical conductivity no less than 10,000 S/cm. ### Claim 8 (depends on 1) The integrated heat sink of claim 1, wherein said heat treatment temperature contains a temperature no less than 2,500° C. and the unitary graphene material has an inter-graphene spacing less than 0.336 nm, a mosaic spread value no greater than 0.4, a thermal conductivity greater than 1,700 W/mK, and/or an electrical conductivity greater than 10,000 S/cm. ### Claim 9 (depends on 1) The integrated heat sink of claim 1, wherein the unitary graphene material exhibits an inter-graphene spacing less than 0.337 nm and a mosaic spread value less than 1.0. ### Claim 10 (depends on 1) The integrated heat sink of claim 1, wherein the unitary graphene material exhibits a degree of graphitization no less than 40% and/or a mosaic spread value less than 0.7. ### Claim 11 (depends on 1) The integrated heat sink of claim 1, wherein the unitary graphene material exhibits a degree of graphitization no less than 80% and/or a mosaic spread value no greater than 0.4. ### Claim 12 (depends on 1) The integrated heat sink of claim 1, wherein said chemically bonded graphene molecules or chemically merged graphene planes are parallel to one another. ### Claim 13 (depends on 1) The integrated heat sink of claim 1, wherein said unitary graphene material contains no complete grain boundary therein, is a graphene single crystal, or a poly-crystal graphene structure with oriented graphene molecules. ### Claim 14 (depends on 1) The integrated heat sink of claim 1, wherein said graphene oxide gel is obtained from a graphitic material having an original graphite grain size and said unitary graphene material is a single crystal or a poly-crystal graphene structure having a grain size larger than said original grain size. ### Claim 15 (depends on 1) The integrated heat sink of claim 1, wherein said graphene oxide gel is obtained from a graphitic material having multiple graphite crystallites exhibiting no preferred crystalline orientation as determined by an X-ray diffraction or electron diffraction method and wherein said unitary graphene material is a single crystal or a poly-crystal graphene structure having a preferred crystalline orientation as determined by said X-ray diffraction or electron diffraction method. ### Claim 16 (depends on 3) The integrated heat sink of claim 3, wherein said carbon, graphite, or graphene filler phase is chemically bonded by said unitary graphene matrix. ### Claim 17 (depends on 1) The integrated heat sink of claim 1, wherein the chemically bonded graphene molecules contain a combination of sp2 and sp3 electronic configurations. ### Claim 18 (depends on 1) The integrated heat sink of claim 1, wherein said unitary graphene matrix composite has a physical density of at least 1.8 g/cm3 or a porosity level lower than 5%. ### Claim 19 (depends on 3) The integrated heat sink of claim 3, wherein said carbon, graphite, or graphene filler phase occupies a weight fraction from 0.1% to 70% based on the total composite structure weight and said unitary graphene material forms a continuous phase. ### Claim 20 (depends on 1) The integrated heat sink of claim 1, wherein said graphene oxide gel is a homogeneous solution composed of graphene oxide molecules dispersed in a liquid acidic medium having a pH value of no higher than 5 and said graphene oxide molecules have an oxygen content no less than 20% by weight while in a gel state. ### Claim 21 (depends on 1) The integrated heat sink of claim 1, wherein said graphene oxide gel is obtained by immersing a graphitic material in a powder or fibrous form in an oxidizing liquid medium in a reaction vessel at a reaction temperature for a length of time sufficient to obtain a homogeneous solution composed of graphene oxide molecules dispersed and dissolved in the liquid medium to form an optically transparent, translucent, or brown colored and said graphene oxide molecules have an oxygen content no less than 20% by weight and a molecular weight less than 43,000 g/mole while in a gel state. ### Claim 22 (depends on 17) The integrated heat sink of claim 17, wherein said graphene oxide molecules have a molecular weight less than 4,000 g/mole while in a gel state. ### Claim 23 (depends on 17) The integrated heat sink of claim 17, wherein said graphene oxide molecules have a molecular weight between 200 g/mole and 4,000 g/mole while in a gel state. ### Claim 24 (depends on 17) The integrated heat sink of claim 17, wherein said graphene oxide gel is produced from oxidation of a graphitic material selected from natural graphite, artificial graphite, meso-phase carbon, meso-phase pitch, meso-carbon micro-bead, soft carbon, hard carbon, coke, carbon fiber, carbon nano-fiber, carbon nano-tube, or a combination thereof. ### Claim 25 (depends on 1) The integrated heat sink of claim 1, wherein said unitary graphene material has an electrical conductivity greater than 3,000 S/cm, a thermal conductivity greater than 600 W/mK, a physical density greater than 1.8 g/cm3, and/or a tensile strength greater than 40 MPa. ### Claim 26 (depends on 1) The integrated heat sink of claim 1, wherein said unitary graphene material has an electrical conductivity greater than 5,000 S/cm, a thermal conductivity greater than 1,000 W/mK, a physical density greater than 1.9 g/cm3, and/or a tensile strength greater than 60 MPa. ### Claim 27 (depends on 1) The integrated heat sink of claim 1, wherein said unitary graphene material has an electrical conductivity greater than 15,000 S/cm, a thermal conductivity greater than 1,500 W/mK, a physical density greater than 2.0 g/cm3, and/or a tensile strength greater than 100 MPa. ### Claim 28 (depends on 1) The integrated heat sink of claim 1, wherein the at least one heat dissipation member comprises fins formed at a surface of the heat collection member. ### Claim 29 An integrated heat sink comprising a unitary graphene material article shaped so as to provide a heat collection surface and at least one heat dissipation surface connected or integral to said heat collection surface, wherein the heat collection surface is configured to be in thermal contact with a heat source, collects heat from said heat source, and dissipates heat through the at least one heat dissipation surface, and further wherein the unitary graphene material is obtained from heat-treating a graphene oxide gel at a heat treatment temperature higher than 500° C. and contains chemically bonded graphene molecules or chemically merged graphene planes having an inter-graphene spacing no greater than 0.40 nm. ### Claim 30 (depends on 1) The integrated heat sink of claim 1, comprising a radial finned heat sink assembly that comprises: (a) a base comprising said heat collection member; and (b) a plurality of spaced parallel planar fin members supported by or integral with the base, wherein said planar fin members comprise said at least one heat dissipation member. ### Claim 31 (depends on 30) The integrated heat sink of claim 30, wherein said plurality of parallel planar fin members are equally spaced. ### Claim 32 (depends on 1) The integrated heat sink of claim 1, comprising a radial finned heat sink assembly that comprises: (a) a base comprising said heat collection member; and (b) a plurality of spaced fin members supported by or integral with the base, wherein said fin members comprise said at least one heat dissipation member. ### Claim 33 (depends on 1) The integrated heat sink of claim 1, wherein said at least one heat dissipation member comprises a surface coated with a high-emissivity material having an emissivity greater than an emissivity of said unitary graphene material. ### Claim 34 (depends on 33) The integrated heat sink of claim 33, wherein said high-emissivity material is selected from aluminum oxide, zinc oxide, aluminum nitride, titanium oxide, boron nitride, silicon carbide, silicon nitride, gallium nitride, or a combination thereof. ### Claim 35 (depends on 33) The integrated heat sink of claim 33, wherein said high-emissivity material is selected from metal or ceramic nano particles. ### Claim 36 (depends on 1) The integrated heat sink of claim 1, wherein said heat source comprises an electronic component. ### Claim 37 (depends on 1) An electronic device containing an integrated heat sink of claim 1. ### Claim 38 (depends on 1) An electronic device comprising a unitary graphene material-based integrated heat sink of claim 1, wherein the unitary graphene material is obtained from heat-treating a graphene oxide gel at a temperature higher than 1,250° C. and contains chemically bonded graphene molecules or chemically merged graphene planes having an inter-graphene spacing no greater than 0.345 nm. ### Claim 39 (depends on 38) The electronic device of claim 38, wherein said unitary graphene material comprises: (a) A unitary graphene matrix containing graphene planes having an inter-graphene plane spacing of 0.3354 to 0.3450 nm and an oxygen content less than 1% by weight; (b) A carbon or graphite filler phase selected from a carbon or graphite fiber, carbon or graphite nano-fiber, carbon nano-tube, carbon nano-rod, meso-phase carbon particle, meso-carbon micro-bead, exfoliated graphite flake with a thickness greater than 100 nm, exfoliated graphite or graphite worm, coke particle, needle coke, carbon black or acetylene black particle, activated carbon particle, a combination thereof, or a combination with a nano graphene platelet; wherein said carbon or graphite filler phase occupies a weight fraction from 1% to 90% based on the total composite weight and said carbon or graphite filler phase is in a particulate, filamentary, or rod-like form dispersed in said unitary graphene matrix which forms a continuous phase. ### Claim 40 (depends on 39) The electronic device of claim 39, wherein said heat treatment temperature is higher than 2,000° C. and the graphene planes have an inter-graphene plane spacing less than 0.337 nm.