# US 2018/0021853 A1 · Dust core, method for manufacturing dust core, inductor including dust core, and electronic/electric device including inductor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0021853 A1 - Document ID: US20180021853A1 - Status: Published application - Kind: A1 - Application number: 15/712,655 - Filed: 2017-09-22 - Published: 2018-01-25 - Earliest claimed: 2015-05-19 - Assignees: Alps Electric Co., Ltd. - Applicants: Alps Electric Co., Ltd. - Inventors: Kinshiro TAKADATE; Hisato KOSHIBA; Shokan YAMASHITA - Web page: https://patentgrep.com/patent/US20180021853A1 ## CPC - B22F 3/00: Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor {; Presses and furnaces} - B22F 1/00: Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties - B22F 1/052: characterised by a mixture of particles of different sizes or by the particle size distribution - B22F 1/06: Metallic powder characterised by the shape of the particles (nanosized particles B22F1/054) - B22F 1/08: Metallic powder characterised by particles having an amorphous microstructure - B22F 1/09: {Mixtures of metallic powders} - B22F 1/102: Metallic powder coated with organic material - B22F 3/02: Compacting only - C22C 38/00: Ferrous alloys, e.g. steel alloys (cast-iron alloys C22C37/00) - C22C 45/02: with iron as the major constituent - H01F 1/153: Amorphous metallic alloys, e.g. glassy metals {(making ferrous amorphous alloys C22C33/003)} - H01F 1/15375: {using polymers} - H01F 1/22: pressed, sintered, or bound together - H01F 1/26: by macromolecular organic substances - H01F 3/08: made from powder (powder coatings on sheets H01F3/02; on strips or ribbons H01F3/04; on wires H01F3/06) - H01F 17/06: with core substantially closed in itself, e.g. toroid - H01F 41/0246: {Manufacturing of magnetic circuits by moulding or by pressing powder (magnetic cores made by moulding or by pressing powder H01F27/255; soft magnetic particles H01F1/20, H01F1/36)} - B22F 2999/00: Aspects linked to processes or compositions used in powder metallurgy - H01F 17/062: {Toroidal core with turns of coil around it} - B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER - C22C: ALLOYS (treatment of alloys C21D, C22F) - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES ## Abstract A dust core contains a powder of a crystalline magnetic material powder and a powder of an amorphous magnetic material. The sum of the content of the crystalline magnetic material powder and the content of the amorphous magnetic material powder is 83 mass percent or more. The mass ratio of the content of the crystalline magnetic material powder to the sum of the content of the crystalline magnetic material powder and the content of the amorphous magnetic material powder is 20 mass percent or less. The median diameter D50 of the amorphous magnetic material powder is greater than or equal to the median diameter D50 of the crystalline magnetic material powder. ## Claims ### Claim 1 A dust core containing: a powder of an amorphous magnetic material having a first median diameter D50a and a first content; and a powder of a crystalline magnetic material having a second median diameter D50c and a second content, wherein a sum of the first content and the second content is 83 mass percent or more, and a mass ratio of the second content to the sum of the first content and the second content is 20 mass percent or less, wherein the first median diameter D50a is equal to or greater than the second median diameter D50c, and wherein a ratio of a 10% cumulative diameter D10a in a volume-based cumulative particle size distribution of the amorphous magnetic material powder to a 90% cumulative diameter D90c in a volume-based cumulative particle size distribution of the crystalline magnetic material powder ranges from 0.3 to 2.6. ### Claim 2 (depends on 1) The dust core according to claim 1, wherein the crystalline magnetic material contains one or more elements selected from the group consisting of Fe—Si—Cr alloys, Fe—Ni alloys, Fe—Co alloys, Fe—V alloys, Fe—Al alloys, Fe—Si alloys, Fe—Si—Al alloys, carbonyl iron, and pure iron. ### Claim 3 (depends on 2) The dust core according to claim 2, wherein the crystalline magnetic material is made of carbonyl iron. ### Claim 4 (depends on 1) The dust core according to claim 1, wherein the amorphous magnetic material contains one or more elements selected from the group consisting of Fe—Si—B alloys, Fe—P—C alloys, and Co—Fe—Si—B alloys. ### Claim 5 (depends on 4) The dust core according to claim 4, wherein the amorphous magnetic material is made of an Fe—P—C alloy. ### Claim 6 (depends on 1) The dust core according to claim 1, wherein the crystalline magnetic material powder is made of an insulated material. ### Claim 7 (depends on 1) The dust core according to claim 1, wherein the second median diameter D50c is 10 μm or less. ### Claim 8 (depends on 1) The dust core according to claim 1, further containing a binding component binding the crystalline magnetic material powder and the amorphous magnetic material powder to another material contained in the dust core. ### Claim 9 (depends on 8) The dust core according to claim 8, wherein the binding component contains a sub-component based on a resin material. ### Claim 10 (depends on 9) A method for manufacturing the dust core according to claim 9, the method comprising a molding step of obtaining a molded product, the molding step including press-molding a mixture containing the crystalline magnetic material powder, the amorphous magnetic material powder, and a binder component made of the resin material. ### Claim 11 (depends on 10) The method according to claim 10, wherein the molded product is the dust core. ### Claim 12 (depends on 10) The method according to claim 10, further comprising a heat treatment step of obtaining the dust core by heat-treating the molded product. ### Claim 13 (depends on 1) An inductor comprising: the dust core according to claim 1; a coil that generates a magnetic field induced by a current applied thereto; and connection terminals each connected to an end portion of the coil, the current being applied to the coil through the connection terminals, wherein at least one portion of the dust core is placed so as to be located in the magnetic field induced by the current. ### Claim 14 (depends on 13) An electronic/electric device comprising: the inductor according to claim 13; and a substrate, wherein the inductor is connected to the substrate through the connection terminals.