# US 10,483,034 B2 · Manufacturing method of coil-embedded inductor using soft magnetic molding solution and coil-embedded inductor manufactured by using the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,483,034 B2 - Document ID: US10483034B2 - Status: Granted - Kind: B2 - Application number: 15/525,854 - Filed: 2017-03-07 - Published: 2018-07-12 - Granted: 2019-11-19 - Earliest claimed: 2016-04-07 - Assignees: Chang Sung Co. - Applicants: Chang Sung Co., Ltd. - Inventors: Tae Kyung Lee; Seung Nam Yang; Sung Jin Choi - Web page: https://patentgrep.com/patent/US10483034B2 ## CPC - 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 1/05: Metallic powder characterised by the size or surface area of the particles - B22F 1/052: characterised by a mixture of particles of different sizes or by the particle size distribution - B22F 1/102: Metallic powder coated with organic material - B22F 1/103: containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent - B22F 1/107: containing organic material comprising solvents, e.g. for slip casting - B22F 3/225: {by injection molding} - C22C 33/0257: {characterised by the range of the alloying elements} - 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 27/255: made from particles (H01F27/26 takes precedence) - H01F 27/28: Coils; Windings; Conductive connections - H01F 27/327: {Encapsulating or impregnating (encapsulating coil and core H01F27/022)} - H01F 41/04: for manufacturing coils {(coils for transformer or inductances H01F27/28)} - B22F 2301/35: Iron - B22F 2304/10: Micron size particles, i.e. above 1 micrometer up to 500 micrometer - H01F 1/14758: {by macromolecular organic substances} - H01F 1/14766: {Fe-Si based alloys} - H01F 1/14791: {Fe-Si-Al based alloys, e.g. Sendust} - H01F 2017/048: {with encapsulating core, e.g. made of resin and magnetic powder} - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - 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) ## Abstract An optimal condition is disclosed in which a composition of a soft magnetic molding solution includes 94 to 98 wt % of a soft magnetic powder and 2 to 6 wt % of an organic vehicle, in order to manufacture a coil-embedded inductor having various advantages such as high inductance, a low core loss, and high reliability. An exemplary manufacturing method is provided of a coil-embedded inductor having a structure in which a part of a coil is embedded in a magnetic core, which includes preparing an organic vehicle, preparing a soft magnetic molding solution having the density of 5.5 to 6.5 g/cc by mix-milling a soft magnetic powder with the organic vehicle, positioning and fixing a part of the coil in the case, and forming the magnetic core by injecting and curing the soft magnetic molding solution into the case. ## Claims ### Claim 1 A manufacturing method of a coil-embedded inductor having a structure in which a part of a coil is embedded in a magnetic core, the manufacturing method comprising: (I) preparing an organic vehicle; (II) preparing a soft magnetic molding solution having a density of 5.5 to 6.5 g/cc by mix-milling a soft magnetic powder with the organic vehicle; (III) positioning and fixing a part of the coil in a case; and (IV) forming the magnetic core by injecting and curing the soft magnetic molding solution into the case, wherein the soft magnetic molding solution in step (II) is formed with a composition ratio of 94 to 98 wt % of the soft magnetic powder and 2 to 6 wt % of the organic vehicle, wherein the soft magnetic powder is formed by mixing three or more soft magnetic powders having different average particle diameters, and wherein the soft magnetic powder is formed by mixing a first soft magnetic powder having an average particle diameter of 2 to 5 μm, a second soft magnetic powder having an average particle diameter of 10 to 20 μm, and a third soft magnetic powder having an average particle diameter of 50 to 150 μm. ### Claim 2 (depends on 1) The manufacturing method of claim 1, comprising: adding a curing agent or a curing accelerator to the soft magnetic molding solution, between step (II) and step (III). ### Claim 3 (depends on 1) The manufacturing method of claim 1, wherein in step (IV), the soft magnetic molding solution is cured in a vacuum atmosphere. ### Claim 4 (depends on 1) The manufacturing method of claim 1, wherein an average particle diameter of the soft magnetic powder is 10 to 150 μm. ### Claim 5 (depends on 1) The manufacturing method of claim 1, wherein the soft magnetic powder includes at least one selection from a group consisting of pure iron, carbonyliron, Fe—Si alloy, Fe—Si—Cr alloy, sendust (Fe—Si—Al alloy), permalloy, and Mo-permalloy. ### Claim 6 (depends on 1) The manufacturing method of claim 1, wherein the organic vehicle in step (I) is prepared by stirring 50 to 60 wt % of a polymer resin and 40 to 50 wt % of a solvent. ### Claim 7 (depends on 6) The manufacturing method of claim 6, wherein the polymer resin includes at least one selection from a group consisting of an epoxy resin, an epoxy acrylate resin, an acrylic resin, a silicone resin, a phenoxy resin and a urethane resin. ### Claim 8 (depends on 6) The manufacturing method of claim 6, wherein the solvent includes at least one selection from a group consisting of methyl cellosolve, ethyl cellosolve, butyl cellosolve, butyl cellosolve acetate, aliphatic alcohol, terpineol, dihydro-terpineol, ethylene glycol, ethyl carbitol, butyl carbitol, butyl carbitol acetate, texanol, methyl ethyl ketone, ethyl acetate, and cyclohexanone. ### Claim 9 (depends on 1) The manufacturing method of claim 1, wherein the organic vehicle in step (I) includes at least additive selected from a group consisting of a dispersant, a stabilizer, a catalyst, and a catalyst activator. ### Claim 10 (depends on 1) A coil-embedded inductor manufactured by the method of claim 1.