Patent ID: 11972910
Assignee: PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO., LTD.
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. An electrolytic capacitor comprising:
a cathode foil having a first principal surface and a second principal surface opposite to the first principal surface; and
a lead member connected to the cathode foil, wherein:
the cathode foil includes a metal foil and a coating layer that covers both principal surfaces of the metal foil,
the metal foil includes a first metal,
the coating layer includes at least one selected from the group consisting of an oxide layer of a second metal, a nitride layer of the second metal, a carbide layer of the second metal, and a conductive layer, the second metal being different from the first metal,
a thickness of the cathode foil ranges from 20 μm to 60 μm, inclusive,
a thickness of the coating layer ranges from 0.1 μm to 5 μm, inclusive,
the cathode foil and the lead member are connected by a caulking part in an overlapping part in which the first principal surface of the cathode foil and the lead member overlap each other,
the caulking part has a through-hole penetrating the cathode foil and the lead member,
the cathode foil in the caulking part includes a first folded part that is folded back at a peripheral edge portion of the through-hole to be disposed on the second principal surface,
the lead member in the caulking part includes (i) a penetrating part that penetrates the cathode foil and (ii) a second folded part that is folded back at an end portion of the penetrating part to be disposed on the second principal surface, the penetrating part including an inner wall of the through-hole,
the second folded part covers the first folded part,
in a cross section of the caulking part that is cut at a plane parallel to a thickness direction of the cathode foil, a length L1 from a center of the through-hole to an edge of the first folded part in a plane direction of the cathode foil is smaller than a length L2 from the center of the through-hole to an edge of the second folded part in the plane direction of the cathode foil, and
a ratio L1/L2 of the length L1 to the length L2 is less than or equal to 0.9.