# US 2014/0190672 A1 · Thermal Interface Materials > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190672 A1 - Document ID: US20140190672A1 - Status: Published application - Kind: A1 - Application number: 14/210,141 - Filed: 2014-03-13 - Published: 2014-07-10 - Earliest claimed: 2007-08-31 - Assignees: Cabot Corporation - Applicants: Cabot Corporation - Inventors: Srinivas H. Swaroop; Timothy D. Davis; Andrea O. Barney - Web page: https://patentgrep.com/patent/US20140190672A1 ## CPC - F28F 13/18: by applying coatings, e.g. radiation-absorbing, radiation-reflecting; by surface treatment, e.g. polishing - C08K 3/01: characterized by their specific function - C08K 3/013: Fillers, pigments or reinforcing additives - C08K 3/22: of metals - Y10T 428/257: Iron oxide or aluminum oxide - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The present invention relates to thermal interface materials comprising a filler dispersed in a polymer, wherein the filler has an average aggregate particle size of less than or equal to 1 micron. Preferably the filler is a synthetic alumina, such as fumed alumina. ## Claims ### Claim at position 1 1-25. (canceled) ### Claim 26 A thermal interface material comprising: at least 27.65% by weight of either an epoxy polymer, a polysiloxane polymer, or both; and a modified fumed alumina dispersed in the polymer, the modified fumed alumina having attached at least one organic group, the modified fumed alumina having an average aggregate particle size of less than or equal to 1 micron and a surface area of greater than or equal to about 30 m2/g. ### Claim 27 (depends on 26) The thermal interface material of claim 26 comprising greater than or equal to 10% by weight of the modified fumed alumina and wherein the viscosity of the thermal interface material consistently decreases with an increasing shear rate from 0.01/s to 100/s. ### Claim 28 (depends on 26) The thermal interface material of claim 26 wherein the at least one organic group is a silane group. ### Claim 29 (depends on 26) The thermal interface material of claim 26 wherein the at least one organic group comprises an alkyl group. ### Claim 30 (depends on 26) The thermal interface material of claim 26, wherein the modified fumed alumina has a surface area of greater than or equal to about 40 m2/g. ### Claim 31 (depends on 26) The thermal interface material of claim 26, wherein the modified fumed alumina has a surface area of greater than or equal to about 50 m2/g. ### Claim 32 (depends on 26) The thermal interface material of claim 26, wherein the modified fumed alumina has a surface area of less than or equal to about 100 m2/g. ### Claim 33 (depends on 26) The thermal interface material of claim 26 wherein the polymer is a polysiloxane resin. ### Claim 34 (depends on 26) The thermal interface material of claim 26 wherein the polymer is an epoxy resin. ### Claim 35 (depends on 26) The thermal interface material of claim 26, wherein the filler is dispersed in the polymer in an amount of between about 5% and about 80% by weight based on the total weight of the material. ### Claim 36 (depends on 26) The thermal interface material of claim 26, wherein the filler is dispersed in the polymer in an amount of between about 30% and about 60% by weight based on the total weight of the material. ### Claim 37 (depends on 26) The thermal interface material of claim 26 further comprising at least one additional particulate material having an average aggregate particle size of greater than 1 micron. ### Claim 38 (depends on 37) The thermal interface material of claim 37, wherein the additional particulate material is fused silica, finely divided quartz powder, amorphous silica, graphite, diamond, silicon carbide, aluminum hydrates, aluminum oxides, zinc oxides, aluminum nitrides, boron nitrides, coarse alumina, or combinations thereof. ### Claim 39 (depends on 37) The thermal interface material of claim 37, wherein the additional particulate material and the modified fumed alumina are dispersed in the polymer in a total amount of between about 25% and about 90% by weight based on the total weight of the dispersed material. ### Claim 40 (depends on 37) The thermal interface material of claim 37, wherein the second particulate material and the modified fumed alumina are dispersed in the polymer in a total amount of between about 30% and about 85% by weight based on the total weight of the material. ### Claim 41 An electronic component system comprising: a heat generating component; a heat dissipating component; and a thermal interface material disposed between the heat generating component and the heat dissipating component, the thermal interface material comprising: a modified fumed alumina having an average aggregate particle size of less than or equal to 1 micron and a surface area of greater than or equal to about 30 m2/g; and a polymer selected from epoxy resins, polysiloxane resins or a combination thereof. ### Claim 42 (depends on 41) The electronic component system of claim 41 wherein the modified fumed alumina comprises a fumed alumina having an organic group attached thereto wherein the organic group is attached to the fumed alumina by a chemical reaction. ### Claim 43 A method comprising: dispersing greater than 10% by weight of a modified fumed alumina in a resin system to produce a dispersion, the modified fumed alumina having an aggregate particle size of less than one micron, and the resin system comprising at least one of an epoxy resin and a polysiloxane resin; disposing the dispersion between a heat generating component and a heat dissipating component; and crosslinking the resin system. ### Claim 44 (depends on 43) The method of claim 43 further comprising dispersing a second alumina in the resin system, the second alumina having an average aggregate particle size of greater than 1 micron. ### Claim 45 (depends on 43) The method of claim 43 comprising dispersing greater than 20% by weight of the modified fumed alumina in the resin system.