Abstract: A power conversion system includes: a self-excited power converter to perform power conversion between a first AC system and a DC system; a first transformer having a primary side connected to the first AC system and a secondary side connected to the self-excited power converter; and a first impedance circuit connected between a ground and a neutral point on the secondary side of the first transformer, or between the ground and an AC line connecting the secondary side of the first transformer and the self-excited power converter. The first impedance circuit includes one of a reactor and another transformer.

Abstract: A semiconductor device includes: a mounting board; and a semiconductor element disposed on the mounting board via metal bumps, wherein the semiconductor element includes a semiconductor stacked structure and first electrodes, the mounting board includes second electrodes, the metal bumps include a first layer in contact with the first electrodes of the semiconductor element and a second layer located on a side opposite to the first electrodes, an average crystal grain size of crystals included in the first layer is larger than an average crystal grain size of crystals included in the second layer, and the second layer is spaced apart from the first electrodes of the semiconductor element.

Abstract: A semiconductor light-emitting element includes: a semiconductor stack including an n-type layer and a p-type layer and having at least one n exposure portion being a recess where the n-type layer is exposed; a p wiring electrode layer on the p-type layer; an insulating layer (i) continuously covering inner lateral surfaces of at least one n exposure portion and part of a top surface of the p wiring electrode layer and (ii) having an opening portion that exposes the n-type layer; an n wiring electrode layer disposed above the p-type layer and the p wiring electrode layer and in contact with the n-type layer in the opening portion; and at least one first n connecting member connected to the n wiring electrode layer in at least one first n terminal region. The n wiring electrode layer and the p-type layer are disposed below at least one first n terminal region.

Abstract: A power conversion device includes a conversion circuit constituted of a plurality of arm circuits and a bypass circuit. The bypass circuit includes a full-wave rectification circuit, a positive-side connection arm, and a negative-side connection arm. The full-wave rectification circuit is connected between a plurality of AC connections, a positive-side intermediate node, and a negative-side intermediate node, and configured to convert AC voltages generated at the plurality of AC connections into a DC voltage across the positive-side intermediate node and the negative-side intermediate node and output the DC voltage. The positive-side connection arm blocks a current in a direction from a positive-side DC terminal toward the positive-side intermediate node. The negative-side connection arm is connected between the negative-side intermediate node and a negative-side DC terminal and blocks a current in a direction from the negative-side intermediate node toward a negative-side DC terminal.

Abstract: A semiconductor light-emitting element includes: a semiconductor layer; an electrode disposed on the semiconductor layer, the electrode including a power feeding portion and an extension portion extending from the power feeding portion. The power feeding portion has a width greater than a width of the extension portion. The electrode includes an electrode layer and a wiring layer. The electrode layer includes a first metal layer disposed in the power feeding portion, and a second metal layer disposed closer to an extension portion side than the first metal layer is and directly connected to the first metal layer. The first metal layer and the second metal layer are in ohmic contact with the semiconductor layer. The first metal layer has an electrical conductivity higher than an electrical conductivity of the second metal layer. The wiring layer is continuously disposed on the first metal layer and the second metal layer.

Abstract: A light-emitting device including: a mounting substrate including a mounting surface; a light-emitting element disposed on the mounting surface; a light transmissive component disposed on the light-emitting element; and a resin component directly contacting and covering a side surface of the light-emitting element and a side surface of the light transmissive component. The resin component includes a peripheral portion that directly contacts and covers the side surface of the light transmissive component, a protrusion that protrudes from the peripheral portion, and a cover portion that directly contacts and covers an outer edge portion of a topmost surface of the light transmissive component. The height from the mounting surface to a top of the cover portion is greater than a height from the mounting surface to the topmost surface of the light transmissive component, and the topmost surface of the light transmissive component includes a region exposed from the resin component.

Abstract: A semiconductor light-emitting element includes: a semiconductor stack including an n-type, layer and a p-type layer and having at least one n exposure portion being a recess where the n-type layer is exposed; a p wiring electrode layer on the p-type layer; an insulating layer (i) continuously covering inner lateral surfaces of at least one n exposure portion and part of a top surface of the p wiring electrode layer and (ii) having an opening portion that exposes the n-type layer; an n wiring electrode layer disposed above the p-type layer and the p wiring electrode layer and in contact with the n-type layer in the opening portion; and at least one first n connecting member connected to the n wiring electrode layer in at least one first n terminal region. The n wiring electrode layer and the p-type layer are disposed below at least one first n terminal region.

Abstract: A semiconductor device includes: a mounting board; and a semiconductor element disposed on the mounting board via metal bumps, wherein the semiconductor element includes a semiconductor stacked structure and first electrodes, the mounting board includes second electrodes, the metal bumps include a first layer in contact with the first electrodes of the semiconductor element and a second layer located on a side opposite to the first electrodes, an average crystal grain size of crystals included in the first layer is larger than an average crystal grain size of crystals included in the second layer, and the second layer is spaced apart from the first electrodes of the semiconductor element.

Abstract: A power converter that performs power conversion between a DC line and an AC system includes a power conversion circuit including a plurality of submodules connected in series with each other, and a controller to control each of the plurality of submodules. Each submodule includes a switching circuit and a capacitor connected in parallel with the switching circuit. When a circuit breaker provided between the AC system and the power conversion circuit is opened, the controller drives the switching circuit of at least one submodule of the plurality of submodules such that the capacitor of the at least one submodule is discharged via a discharge circuit connected to the DC line.

Abstract: A light-emitting device includes: a mounting substrate including a mounting surface; a light-emitting element disposed on the mounting surface; a light transmissive component disposed on the light-emitting element; and a resin component that covers a side surface of the light-emitting element and a side surface of the light transmissive component. The resin component includes a cover portion that covers an outer edge portion of a topmost surface of the light transmissive component. A height from the mounting surface to a top of the cover portion is greater than a height from the mounting surface to the topmost surface of the light transmissive component. The topmost surface of the light transmissive component includes an exposed region that is exposed from the resin component. The cover portion is disposed continuously along one side of the light transmissive component.

Abstract: A semiconductor device includes: a mounting board; and a semiconductor element disposed on the mounting board via metal bumps, wherein the semiconductor element includes a semiconductor stacked structure and first electrodes, the mounting board includes second electrodes, the metal bumps include a first layer in contact with the first electrodes of the semiconductor element and a second layer located on a side opposite to the first electrodes, an average crystal grain size of crystals included in the first layer is larger than an average crystal grain size of crystals included in the second layer, and the second layer is spaced apart from the first electrodes of the semiconductor element.

Abstract: A light source device includes: a substrate; a light-emitting unit matrix including a plurality of light-emitting units disposed in a matrix on the substrate; and a reflective resin disposed in a region, on the substrate, including a region where the light-emitting unit matrix is disposed. The plurality of light-emitting units include a first light-emitting unit and a second light-emitting unit adjacent to each other in a column direction of the light-emitting unit matrix. The reflective resin includes a first reflective portion disposed between the first light-emitting unit and the second light-emitting unit and extending in a direction intersecting the column direction. At least a portion of an upper surface of the first reflective portion protrudes beyond an upper surface of the first light-emitting unit and an upper surface of the second light-emitting unit.

Abstract: A power conversion device according to one embodiment includes a plurality of submodules connected in series to each other. In each submodule, a first terminal, a second terminal and a third terminal are provided on or provided to protrude from a surface of a package. A first semiconductor switching element is built into the package and connected between the first terminal and the second terminal. A second semiconductor switching element is built into the package and connected between the second terminal and the third terminal. A DC capacitor is built into the package and connected between the first terminal and the third terminal.

Abstract: A semiconductor light emitting element includes: a substrate; an n-type layer; a light emitting layer; a p-type layer; a p electrode located above the p-type layer; an n electrode located in a region that is above the n-type layer and in which the light emitting layer and the p-type layer are not located; a p-electrode bump connected to the p electrode; an n-electrode bump connected to the n electrode; and an insulation bump located in at least one of a region between the n-electrode bump and the p-type layer and a region whose distance from an end of the p-type layer closer to the n-electrode bump is shorter than a distance from the end to the p-electrode bump, in a plan view of the substrate. A surface of the insulation bump opposite to a surface facing the substrate is insulated from the p electrode and the n electrode.

Abstract: A light-emitting device includes: a mounting substrate including a mounting surface; a light-emitting element disposed on the mounting surface; a light transmissive component disposed on the light-emitting element; and a resin component that covers a side surface of the light-emitting element and a side surface of the light transmissive component. The resin component includes a cover portion that covers an outer edge portion of a topmost surface of the light transmissive component. A height from the mounting surface to a top of the cover portion is greater than a height from the mounting surface to the topmost surface of the light transmissive component. The topmost surface of the light transmissive component includes an exposed region that is exposed from the resin component. The cover portion is disposed continuously along one side of the light transmissive component.

Abstract: A semiconductor light-emitting element includes: a semiconductor stack including an n-type, layer and a p-type layer and haying at least one n exposure portion being a recess where the n-type layer is exposed; a p wiring electrode layer on the p-type layer; an insulating layer (i) continuously covering inner lateral surfaces of at least one n exposure portion and part of a top surface of the p wiring electrode layer and (ii) having an opening portion that exposes the n-type layer; an n wiring electrode layer disposed above the p-type layer and the p wiring electrode layer and in contact with the n-type layer in the opening portion; and at least one first n connecting member connected to the n wiring electrode layer in at least one first n terminal region. The n wiring electrode layer and the p-type layer are disposed below at least one first n terminal region.

Abstract: A power conversion device includes a plurality of cascaded converter cells. In each of the converter cells, each of a plurality of arms forming a bridge circuit is provided with a plurality of semiconductor switching elements in parallel. A drive controller of each of the converter cells is configured to, when none of a plurality of predetermined abnormality modes is detected, control the bridge circuit in accordance with an externally provided command. The drive controller is configured to, when at least one of the plurality of abnormality modes is detected, turn on all semiconductor switching elements provided in at least one of the plurality of arms forming the bridge circuit, to thereby establish a short circuit between first and second input/output nodes.

Abstract: A white light emitting device includes: first light-emitting units to which a first current is applied; and second light-emitting units to which a second current which is different from the first current is applied. When the first current is applied to the first light-emitting units and the second current is applied to the second light-emitting units, an average emission chromaticity of the first light-emitting units and an average emission chromaticity of the second light-emitting units are identical colors. When the same current is applied to both the first light-emitting units and the second light-emitting units, the average emission chromaticity of the first light-emitting units and the average emission chromaticity of the second light-emitting units are non-identical colors.

Abstract: A semiconductor device includes: a first electrode provided on a semiconductor multilayer structure; a second electrode provided on a substrate; and a bonding metal layer which bonds the first electrode and the second electrode together. The bonding metal layer includes a gap inside.

Abstract: A power conversion device includes a conversion circuit constituted of a plurality of arm circuits and a bypass circuit. The bypass circuit includes a full-wave rectification circuit, a positive-side connection arm, and a negative-side connection arm. The full-wave rectification circuit is connected between a plurality of AC connections, a positive-side intermediate node, and a negative-side intermediate node, and configured to convert AC voltages generated at the plurality of AC connections into a DC voltage across the positive-side intermediate node and the negative-side intermediate node and output the DC voltage. The positive-side connection arm blocks a current in a direction from a positive-side DC terminal toward the positive-side intermediate node. The negative-side connection arm is connected between the negative-side intermediate node and a negative-side DC terminal and blocks a current in a direction from the negative-side intermediate node toward a negative-side DC terminal.