Abstract: An insulating substrate in which one principal surface of a heat-dissipation-side metal plate is bonded to one principal surface of a ceramic substrate via a brazing material layer provided therebetween, and a solder resist portion is formed on at least one selected from a periphery of the other principal surface of the heat-dissipation-side metal plate, a side surface of the heat-dissipation-side metal plate, and a surface of the brazing material layer. A solder resist prevents solder from wrapping around the brazing material layer, and thereby, what is called “the brazing material layer leaching into solder” no longer occurs and the occurrence of cracks inside the brazing material layer is avoided. This prevents stress concentration from occurring in the ceramic substrate at an inner portion relative to an end portion of the heat-dissipation-side metal plate.

Abstract: An insulating substrate in which one principal surface of a heat-dissipation-side metal plate is brazed to one principal surface of a ceramic substrate via a brazing material layer provided therebetween, in which a Ni plating layer that covers the brazing material layer exposed between the ceramic substrate and the heat-dissipation-side metal plate is provided, and at least a portion of the other principal surface of the heat-dissipation-side metal plate is not covered with a Ni plating layer, leaving the surface of the heat-dissipation-side metal plate exposed. According to the present invention, it becomes possible to obtain the insulating substrate having excellent furnace passing resistance of the insulating substrate (alone) and further having excellent heat cycle characteristics in a state of a heat sink plate being soldered to the insulating substrate.

Abstract: A coil component includes a core that has a columnar winding core portion and a flange formed at an end of the winding core portion in an axial direction. The coil component also includes a terminal electrode formed at an end surface of the flange and a wire being wound around the winding core portion with one end portion coupled to the terminal electrode. The flange protrudes toward the first end of the coil component in the first direction. A curved surface and an inclined surface are formed at a boundary between a surface of the flange and a peripheral surface of the winding core portion. The inclined surface has a curvature smaller than that of the curved surface. In addition, the inclined surface is disposed where the wire intersects the boundary as viewed in the first direction.

Abstract: A coil component includes a core having a winding core portion and one pair of guard portions, a terminal electrode provided on each guard portion, and a wire wound around the winding core portion and having both ends electrically connected to the terminal electrodes. Each guard portion has an inner end face, an outer end face, a bottom surface, a top surface, and two side surfaces. Each terminal electrode has a bottom surface electrode portion continuous over at least the bottom surface and an outer end face electrode portion on the outer end face. The bottom surface electrode portion has a side surface extension portion located lower than a lowest portion of the winding core portion. The outer end face electrode portion is connected to the bottom surface electrode portion, and both end edges of the outer end face electrode portion are located away from both the side surfaces.