Abstract: A power transmission device may include a casing; and a plurality of gears located in the casing and being lubricated by a lubricant in the casing, wherein the plurality of gears may include a first gear that upwardly displaces the lubricant accumulating at a lower portion in the casing by rotation of the first gear; the casing may include a facing wall facing a side surface of the first gear; the facing wall may include a first rib that protrudes toward the side surface of the first gear and extends along a circumferential direction of the first gear; and the side surface of the first gear, the first rib, and the facing wall may define a first lubricant passage that guides the lubricant displaced upward by the first gear along the circumferential direction.

Abstract: A drive unit may include a case comprising an electric motor chamber and a gear chamber; an electric motor comprising a rotor housed in the electric motor chamber; a specific gear housed in the gear chamber; lubricant stored in the electric motor chamber and the gear chamber; and a through hole connecting the electric motor chamber and the gear chamber. An opening of the through hole on a gear chamber side may be positioned so as to face a side surface of the specific gear. A region below a center of the specific gear is defined as a lower region, a part of the lower region that is located rearward of a vertical plane passing through a center axis of the specific gear in a rotation direction of the specific gear is defined as a lower rear region, and the opening may be in the lower rear region.

Abstract: An aluminum wire with which, at the time of bonding a bonding wire for a power semiconductor, the wire is not detached from a wedge tool, and a long life is achieved in a power cycle test. The aluminum wire is made of an aluminum alloy having an aluminum purity of 99 mass % or more and contains, relative to a total amount of all elements of the aluminum alloy, a total of 0.01 mass % or more and 1 mass % or less of iron and silicon. In a lateral cross-section in a direction perpendicular to a wire axis of the aluminum wire, an orientation index of is 1 or more, an orientation index of is 1 or less, and an area ratio of precipitated particles is in a range of 0.02% or more to 2% or less.

Abstract: The bonding wire being a Pd-coated copper bonding wire includes: a copper core material; and a Pd layer and containing a sulfur group element, in which with respect to the total of copper, Pd, and the sulfur group element, a concentration of Pd is 1.0 mass % to 4.0 mass % and a total concentration of the sulfur group element is 50 mass ppm or less, and a concentration of S is 5 mass ppm to 2 mass ppm, a concentration of Se is 5 mass ppm to 20 mass ppm, or a concentration of Te is 15 mass ppm to 50 mass ppm or less. A wire bonding structure includes a Pd-concentrated region with the concentration of Pd being 2.0 mass % or more relative to the total of Al, copper, and Pd near a bonding surface of an Al-containing electrode of a semiconductor chip and a ball bonding portion.

Abstract: A Pd-coated Cu bonding wire of an embodiment contains Pd of 1.0 to 4.0 mass %, and a S group element of 50 mass ppm or less in total (S of 5.0 to 12.0 mass ppm, Se of 5.0 to 20.0 mass ppm, or Te of 15.0 to 50 mass ppm). At a crystal plane of a cross section of the wire, a <100> orientation ratio is 15% or more, and a <111> orientation ratio is 50% or less. When a free air ball is formed on the wire and a tip portion is analyzed, a Pd-concentrated region is observed on the surface thereof.

Abstract: The bonding wire being a Pd-coated copper bonding wire includes: a copper core material; and a Pd layer and containing a sulfur group element, in which with respect to the total of copper, Pd, and the sulfur group element, a concentration of Pd is 1.0 mass % to 4.0 mass % and a total concentration of the sulfur group element is 50 mass ppm or less, and a concentration of S is 5 mass ppm to 2 mass ppm, a concentration of Se is 5 mass ppm to 20 mass ppm, or a concentration of Te is 15 mass ppm to 50 mass ppm or less. A wire bonding structure includes a Pd-concentrated region with the concentration of Pd being 2.0 mass % or more relative to the total of Al, copper, and Pd near a bonding surface of an Al-containing electrode of a semiconductor chip and a ball bonding portion.