# US 11,993,679 B2 · Thermally conductive sheet > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,993,679 B2 - Document ID: US11993679B2 - Status: Granted - Kind: B2 - Application number: 17/252,508 - Filed: 2019-06-18 - Published: 2021-08-26 - Granted: 2024-05-28 - Earliest claimed: 2018-06-22 - Assignees: Sekisui Polymatech Co., Ltd. - Applicants: Sekisui Polymatech Co., Ltd. - Inventors: Hiroki Kudoh; Taku Sasaki; Kana Hattori; Kazuyuki Yahara; Yasunari Kusaka - Web page: https://patentgrep.com/patent/US11993679B2 ## CPC - C08G 77/18: to alkoxy or aryloxy groups - H10W 40/251: {Organics} - C08G 77/06: Preparatory processes - C08J 5/18: Manufacture of films or sheets - C08K 3/22: of metals - C08K 7/06: Elements - H05K 7/2039: {characterised by the heat transfer by conduction from the heat generating element to a dissipating body (arrangements for increasing/decreasing heat-transfer, e.g. fins details, F28F13/00)} - C08K 3/04: Carbon - C08K 2003/2227: {of aluminium} - F28F 21/06: of plastics material - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16) ## Abstract A thermally conductive sheet 10 of the present invention comprises a polymer matrix 12 and an anisotropic filler 13, and the anisotropic filler 13 is oriented in a thickness direction. The anisotropic filler 13 is disposed in such a way as to fall down in a proportion of 1 to 45% in the vicinity of surfaces 10A, 10B of the thermally conductive sheet 10. According to the present invention, a thermally conductive sheet capable of sufficiently improving the thermal conductive properties in the thickness direction can be provided. ## Claims ### Claim 1 A thermally conductive sheet comprising: a polymer matrix; and an anisotropic filler, wherein a first portion of the anisotropic filler is oriented in a thickness direction, wherein a second portion of the anisotropic filler is disposed in such a way as to lie down near a surface of the thermally conductive sheet, the surface being observed with an optical microscope, wherein the second portion of the anisotropic filler is 1 to 45% of a total number of the anisotropic fillers observed in an observation image observed with the optical microscope, and wherein a proportion of the anisotropic filler which is disposed in such a way as to lie down near the surface is larger than a proportion of the anisotropic filler which is disposed in such a way as to lie down inside the thermally conductive sheet. ### Claim 2 (depends on 1) The thermally conductive sheet according to claim 1, wherein the anisotropic filler is not exposed on the surface of the thermally conductive sheet. ### Claim 3 (depends on 1) The thermally conductive sheet according to claim 1, wherein the anisotropic filler is a fiber material. ### Claim 4 (depends on 3) The thermally conductive sheet according to claim 3, wherein the fiber material is a carbon fiber. ### Claim 5 (depends on 4) The thermally conductive sheet according to claim 4, wherein the carbon fiber is covered with an insulating layer. ### Claim 6 (depends on 5) The thermally conductive sheet according to claim 5, wherein the insulating layer comprises silicon dioxide. ### Claim 7 (depends on 3) The thermally conductive sheet according to claim 3, wherein the fiber material has an average fiber length of 50 to 500 μm. ### Claim 8 (depends on 1) The thermally conductive sheet according to claim 1, further comprising a non-anisotropic filler. ### Claim 9 (depends on 8) The thermally conductive sheet according to claim 8, wherein the non-anisotropic filler is at least one selected from the group consisting of alumina, aluminum, zinc oxide, boron nitride, and aluminum nitride. ### Claim 10 (depends on 8) The thermally conductive sheet according to claim 8, wherein a ratio of a volume filling ratio of the non-anisotropic filler to a volume filling ratio of the anisotropic filler is 2 to 5. ### Claim 11 (depends on 1) The thermally conductive sheet according to claim 1, wherein at least part of the anisotropic filler which is disposed in such a way as to fall down on the surface is disposed in such a way as to incline with respect to the surface. ### Claim 12 (depends on 1) The thermally conductive sheet according to claim 1, wherein the polymer matrix is addition reaction-curable type-silicone. ### Claim 13 (depends on 1) The thermally conductive sheet according to claim 1, wherein the thermally conductive sheet has a thickness of 0.1 to 5 mm. ### Claim 14 (depends on 1) The thermally conductive sheet according to claim 1, wherein the thermally conductive sheet has a thermal conductivity in a thickness direction of 6 w/m·K or more.