# US 12,224,130 B2 · Film capacitor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,224,130 B2 - Document ID: US12224130B2 - Status: Granted - Kind: B2 - Application number: 17/389,997 - Filed: 2021-07-30 - Published: 2021-11-18 - Granted: 2025-02-11 - Earliest claimed: 2019-02-07 - Assignees: Murata Manufacturing Co., Ltd. - Applicants: Murata Manufacturing Co., Ltd. - Inventors: Senichi Ozasa; Kimiaki Kikuchi; Satoru Jogan - Web page: https://patentgrep.com/patent/US12224130B2 ## CPC - H01G 4/32: Wound capacitors - H01G 4/005: Electrodes - H01G 4/018: Dielectrics - H01G 4/224: Housing; Encapsulation - H01G 4/33: Thin- or thick-film capacitors {(thin- or thick-film circuits; capacitors without a potential-jump or surface barrier specially adapted for integrated circuits, details thereof, multistep manufacturing processes therefor)} - H01G: CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE (selection of specified materials as dielectric H01B3/00; capacitors having potential barriers H10D1/62, H10K10/10) ## Abstract A film capacitor that includes a capacitor element including one or more wound or laminated metallized films, each metallized film including a dielectric resin film and a metal layer on one surface of the dielectric resin film; a cover covering an outer surface of the capacitor element in a direction in which layers of the dielectric resin film are laminated with the metal layer therebetween; and an exterior body covering an outer periphery of the capacitor element and an outer surface of the cover. In a first aspect, the dielectric resin film contains a curable resin as a main component thereof, and the cover is made of a thermoplastic resin. ## Claims ### Claim 1 A film capacitor comprising: a capacitor element including one or more wound or laminated metallized films, each metallized film including a dielectric resin film and a metal layer on one surface of the dielectric resin film, wherein the dielectric resin film contains a curable resin as a main component thereof; a thermoplastic resin cover covering an outer surface of the capacitor element in a direction in which layers of the dielectric resin film are laminated with the metal layer therebetween; and an exterior body covering an outer periphery of the capacitor element and an outer surface of the cover, wherein the thermoplastic resin cover is a wound film that is wound around the outer surface of the capacitor element, and the wound film has at least one surface that is a roughened surface. ### Claim 2 (depends on 1) The film capacitor according to claim 1, wherein in the direction in which the layers of the dielectric resin film are laminated, the thermoplastic resin cover has a thickness that is 0.5% to 5% of a thickness of the capacitor element. ### Claim 3 (depends on 1) The film capacitor according to claim 1, wherein the wound film has only one roughened surface, and the only one roughened surface is closer to the exterior body than the capacitor element. ### Claim 4 (depends on 1) The film capacitor according to claim 1, wherein the roughened surface has a surface roughness Ra of 0.05 μm to 0.3 μm. ### Claim 5 A film capacitor comprising: a capacitor element including one or more wound or laminated metallized films, each metallized film including a dielectric resin film and a metal layer on one surface of the dielectric resin film, wherein the dielectric resin film contains a curable resin as a main component thereof; a thermoplastic resin cover covering an outer surface of the capacitor element in a direction in which layers of the dielectric resin film are laminated with the metal layer therebetween; and an exterior body covering an outer periphery of the capacitor element and an outer surface of the cover, wherein the thermoplastic resin cover is a wound film that is wound around the outer surface of the capacitor element, the wound film has irregularities on opposed surfaces thereof, and protrusions of the irregularities each have a height of 0.01 mm to 0.1 mm. ### Claim 6 (depends on 5) The film capacitor according to claim 5, wherein the irregularities include protrusions on a first of the opposed surfaces and recesses on a second of the opposed surfaces, the protrusions being positioned at corresponding positions of the recesses. ### Claim 7 A film capacitor comprising: a capacitor element including one or more wound or laminated metallized films, each metallized film including a dielectric resin film and a metal layer on one surface of the dielectric resin film; a cover covering an outer surface of the capacitor element in a direction in which layers of the dielectric resin film are laminated with the metal layer therebetween; and an exterior body covering an outer periphery of the capacitor element and an outer surface of the cover, wherein the cover has an elastic modulus, and the elastic modulus of the cover at 25° C. is 30% to 150% of an elastic modulus of the dielectric resin film at 25° C., and the elastic modulus of the cover at 125° C. is 1% to 30% of the elastic modulus of the dielectric resin film at 125° C. ### Claim 8 (depends on 7) The film capacitor according to claim 7, wherein the cover is a wound film that is wound around the outer surface of the capacitor element. ### Claim 9 (depends on 7) The film capacitor according to claim 7, wherein the cover is a coating on the outer surface of the capacitor element. ### Claim 10 (depends on 8) The film capacitor according to claim 8, wherein the wound film has at least one surface that is a roughened surface. ### Claim 11 (depends on 8) The film capacitor according to claim 8, wherein the wound film has irregularities on opposed surfaces thereof. ### Claim 12 (depends on 9) The film capacitor according to claim 9, wherein the coating includes air bubbles therein. ### Claim 13 (depends on 10) The film capacitor according to claim 10, wherein the wound film has only one roughened surface, and the only one roughened surface is closer to the exterior body than the capacitor element. ### Claim 14 (depends on 10) The film capacitor according to claim 10, wherein the roughened surface has a surface roughness Ra of 0.05 μm to 0.3 μm. ### Claim 15 (depends on 11) The film capacitor according to claim 11, wherein the irregularities include protrusions on a first of the opposed surfaces and recesses on a second of the opposed surfaces, the protrusions being positioned at corresponding positions of the recesses. ### Claim 16 (depends on 11) The film capacitor according to claim 11, wherein protrusions of the irregularities each have a height of 0.01 mm to 0.1 mm. ### Claim 17 (depends on 7) The film capacitor according to claim 7, wherein the dielectric resin film contains a curable resin as a main component thereof, and the cover is made of a thermoplastic resin. ### Claim 18 (depends on 7) The film capacitor according to claim 7, wherein in the direction in which the layers of the dielectric resin film are laminated, the cover has a thickness that is 0.5% to 5% of a thickness of the capacitor element. ### Claim 19 A film capacitor comprising: a capacitor element including one or more wound or laminated metallized films, each metallized film including a dielectric resin film and a metal layer on one surface of the dielectric resin film; a cover comprising a wound film wound around an outer surface of the capacitor element in a direction in which layers of the dielectric resin film are laminated with the metal layer therebetween, and the wound film has at least one surface that is a roughened surface or has irregularities on opposed surfaces thereof; and an exterior body covering an outer periphery of the capacitor element and an outer surface of the cover, wherein the wound film has only on one roughened surface, and the only one roughened surface is closer to the exterior body than the capacitor element. ### Claim 20 (depends on 19) The film capacitor according to claim 19, wherein voids are present in at least a portion between the wound film and the exterior body or between the wound film and the capacitor element. ### Claim 21 (depends on 16) The film capacitor according to claim 16, wherein the roughened surface has a surface roughness Ra of 0.05 μm to 0.3 μm. ### Claim 22 (depends on 19) The film capacitor according to claim 19, wherein the dielectric resin film contains a curable resin as a main component thereof, and the cover is made of a thermoplastic resin. ### Claim 23 (depends on 19) The film capacitor according to claim 19, wherein in the direction in which the layers of the dielectric resin film are laminated, the cover has a thickness that is 0.5% to 5% of a thickness of the capacitor element. ### Claim 24 A film capacitor comprising: a capacitor element including one or more wound or laminated metallized films, each metallized film including a dielectric resin film and a metal layer on one surface of the dielectric resin film; a cover comprising a wound film wound around an outer surface of the capacitor element in a direction in which layers of the dielectric resin film are laminated with the metal layer therebetween, and the wound film has at least one surface that is a roughened surface or has irregularities on opposed surfaces thereof; and an exterior body covering an outer periphery of the capacitor element and an outer surface of the cover, wherein protrusions of the irregularities each have a height of 0.01 mm to 0.1 mm. ### Claim 25 (depends on 24) The film capacitor according to claim 24, wherein the irregularities include protrusions on a first of the opposed surfaces and recesses on a second of the opposed surfaces, the protrusions being positioned at corresponding positions of the recesses.