# US 12,603,216 B2 · Coil component > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,603,216 B2 - Document ID: US12603216B2 - Status: Granted - Kind: B2 - Application number: 18/189,667 - Filed: 2023-03-24 - Published: 2023-10-05 - Granted: 2026-04-14 - Earliest claimed: 2022-03-29 - Assignees: Murata Manufacturing Co., Ltd. - Applicants: Murata Manufacturing Co., Ltd. - Inventors: Keiichi Ishida - Web page: https://patentgrep.com/patent/US12603216B2 ## CPC - H01F 1/26: by macromolecular organic substances - H01F 27/022: {Encapsulation} - H01F 1/20: in the form of particles, e.g. powder (H01F1/147 takes precedence) - H01F 1/33: mixtures of metallic and non-metallic particles; metallic particles having oxide skin - H01F 1/342: {Oxides (H01F1/36 and H01F1/38 take precedence)} - H01F 17/04: with magnetic core - H01F 27/255: made from particles (H01F27/26 takes precedence) - H01F 27/292: {Surface mounted devices} - H01F 27/32: Insulating of coils, windings, or parts thereof - H01F 41/12: Insulating of windings ({impregnating or encapsulating of transformers H01F41/005} ; of conductors in general H01B13/06) - 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 ## Abstract A coil component includes an element assembly including a coil conductor formed by winding a conductor coated with an electrically insulating film and a magnetic portion containing metal magnetic particles and resin, and an outer electrode electrically connected to an exposed surface, exposed on a surface of the element assembly, of an extended part of the coil conductor and disposed on a surface of the element assembly. The metal magnetic particles include first and second metal magnetic particles. A particle size distribution of the magnetic particles, calculated in accordance with a circle equivalent diameter obtained from a cross-sectional image in a cross section of the magnetic portion, has at least two peaks and at least one bottom. The first magnetic particles are larger than or equal to the bottom having a minimum frequency, and the second metal magnetic particles are smaller than the bottom having the minimum frequency. ## Claims ### Claim 1 A coil component comprising: an element assembly including a coil conductor including a wound conductor, and a magnetic portion containing metal magnetic particles and resin; and an outer electrode electrically connected to an exposed surface, exposed on a surface of the element assembly, of an extended part of the coil conductor and disposed on the surface of the element assembly, wherein the metal magnetic particles include first metal magnetic particles and second metal magnetic particles, a particle size distribution of the metal magnetic particles, calculated in accordance with a circle equivalent diameter obtained from a cross-sectional image in a cross section of the magnetic portion, has at least two peaks and at least one bottom, and those of the metal magnetic particles larger than or equal to the bottom having a minimum frequency are defined as the first metal magnetic particles, and those of the metal magnetic particles smaller than the bottom having the minimum frequency are defined as the second metal magnetic particles, the first metal magnetic particles include particles each having a recessed portion that satisfies a predetermined condition in the cross section, the predetermined condition is L02>L01 where a minimum distance between distal ends at an opening of the recessed portion is L01 and a longest distance of line segments parallel to a line segment that has the minimum distance between the distal ends at the opening in line segments corresponding to chords in the recessed portion of a cross section of each of the first metal magnetic particles is L02, and at least part of at least one of the second metal magnetic particles is inside the recessed portion of at least one of the first metal magnetic particles. ### Claim 2 (depends on 1) The coil component according to claim 1, wherein a whole of at least one of the second metal magnetic particles is inside the recessed portion of at least one of the first metal magnetic particles. ### Claim 3 (depends on 2) The coil component according to claim 2, wherein of the first metal magnetic particles each having the recessed portion, a percentage of the number of the first metal magnetic particles having the recessed portion inside which at least part of at least one of the second metal magnetic particles is disposed is higher than or equal to 50% in the cross section of the magnetic portion. ### Claim 4 (depends on 1) The coil component according to claim 1, wherein of the first metal magnetic particles each having the recessed portion, a percentage of the number of the first metal magnetic particles having the recessed portion inside which at least part of at least one of the second metal magnetic particles is disposed is higher than or equal to 50% in the cross section of the magnetic portion. ### Claim 5 (depends on 1) The coil component according to claim 1, wherein when a whole of at least one of the second metal magnetic particles is inside the recessed portion of at least one of the first metal magnetic particles, a content of the second metal magnetic particles inside the recessed portion is higher than or equal to 40% on average in the cross section of the magnetic portion. ### Claim 6 (depends on 1) The coil component according to claim 1, wherein in the cross section of the magnetic portion, at least part of at least one of other first metal magnetic particles and at least part of the second metal magnetic particles are inside the recessed portion of at least one of the first metal magnetic particles, and a content of the other first metal magnetic particles and the second metal magnetic particles in the recessed portion of the first metal magnetic particles is higher than or equal to 50% on average. ### Claim 7 (depends on 1) The coil component according to claim 1, wherein a peak having a maximum frequency in the particle size distribution of the first metal magnetic particles is from 10 μm to 50 μm. ### Claim 8 (depends on 1) The coil component according to claim 1, wherein a peak having a maximum frequency in the particle size distribution of the second metal magnetic particles is from 0.2 μm to 10 μm. ### Claim 9 (depends on 1) The coil component according to claim 1, wherein each of the first metal magnetic particles and each of the second metal magnetic particles have the same composition. ### Claim 10 (depends on 1) The coil component according to claim 1, wherein an electrically insulating coating is on an outer surface of each of the first metal magnetic particles, and an electrically insulating coating is absent from at least part of a surface inside the recessed portion of each of the first metal magnetic particles. ### Claim 11 (depends on 1) The coil component according to claim 1, wherein a content of the resin is from 5% to 25% in area in the cross section of the magnetic portion. ### Claim 12 (depends on 1) The coil component according to claim 1, wherein where a total content of the first metal magnetic particles and the second metal magnetic particles is 100% in area, a content of the first metal magnetic particles is from 40% to 85% and a content of the second metal magnetic particles is from 15% to 60%. ### Claim 13 (depends on 1) The coil component according to claim 1, wherein where an outer perimeter of the first metal magnetic particle having the recessed portion is L1 and a perimeter of a circle having an area of an equivalent circle is L2 in the cross section of the magnetic portion, an average value of L1/L2 is less than or equal to 5.0. ### Claim 14 (depends on 1) The coil component according to claim 1, wherein where the minimum distance between the distal ends at the opening of the recessed portion of each of the first metal magnetic particles is L01 and a perimeter other than an inside of the opening of the recessed portion of each of the first metal magnetic particles is Lc in the cross section of the magnetic portion, an average value of L01/(Lc+L01) is from 0.03 to 0.4. ### Claim 15 (depends on 1) The coil component according to claim 1, wherein where a particle size at which a peak having a maximum frequency is located in a particle size distribution of the second metal magnetic particles is d2, an average value of the minimum distance L01 between the distal ends at the opening of the recessed portion of each of the first metal magnetic particles in the cross section of the magnetic portion satisfies L01>d2. ### Claim 16 (depends on 1) The coil component according to claim 1, wherein where an area of a region inside a line segment that has the minimum distance between the distal ends at the opening of the recessed portion of each of the first metal magnetic particles is S0 and a cross-sectional area of each of the first metal magnetic particles having the recessed portion is Sc in the cross section of the magnetic portion, an average value of S0/(Sc+S0) is from 0.05 to 0.8. ### Claim 17 (depends on 1) The coil component according to claim 1, wherein the magnetic portion further contains inorganic oxide particles. ### Claim 18 (depends on 17) The coil component according to claim 17, wherein in the cross section of the magnetic portion, at least part of at least one of the second metal magnetic particles and at least part of at least one of the inorganic oxide particles are in the recessed portion of at least one of the first metal magnetic particles. ### Claim 19 (depends on 17) The coil component according to claim 17, wherein the inorganic oxide particles are glass. ### Claim 20 (depends on 17) The coil component according to claim 17, wherein the inorganic oxide particles are ferrite.