Abstract: An optical semiconductor device package includes a circuit board in which a first metal, a second metal, and a third metal are sequentially stacked in an optical semiconductor element mounting region. The first metal has a first standard electrode potential. The second metal is disposed on a portion of an upper surface of the first metal and has a second standard electrode potential that is greater than the first standard electrode potential. The third metal is disposed on the upper surface of the first metal and an upper surface of the second metal and has a third standard electrode potential that is greater than the first standard electrode potential and less than the second standard electrode potential.

Abstract: A battery module includes a plurality of cylindrical batteries that each include a safety valve surrounded by an annular breaking portion configured to break when internal pressure of each of the batteries exceeds a predetermined level. The battery module further includes an exhaust duct to guide gas emitted from the cylindrical battery to outside the module when safety valve is opened, and a gas direction regulator component disposed between the cylindrical batteries and the exhaust duct. The gas direction regulator component has a plurality of openings to expose the respective safety valves. Portions of the gas direction regulator component overhang areas overlapping the respective safety valves so as to cover an end of each safety valve opposite another end of each safety valve adjacent to an exit of the exhaust duct.

Abstract: An electrolytic capacitor includes an anode body, a dielectric layer disposed on a surface of the anode body, and a solid electrolyte layer disposed on a surface of the dielectric layer. The solid electrolyte layer includes a conductive polymer and a first compound. The first compound has a naphthalene skeleton, and includes at least one COOM1 group and at least one sulfonate group. The at least one sulfonate group is bonded to the naphthalene skeleton. The at least one COOM1 group is bonded to the naphthalene skeleton, where M1 is a hydrogen atom, a metal atom, or an onium group.