Abstract: An electronic component mounting package is provided with a metal substrate including a first surface, a recessed portion opening on the first surface, and a mounting portion for an electronic component in the recessed portion, and a wiring conductor located on the first surface via an insulation layer other than at the opening of the recessed portion, and a metal oxide film is included on at least a part of the inner side surface of the recessed portion.

Abstract: An electronic component mounting substrate includes: a metal substrate including a first surface, an insulation substrate including a second surface on which a first metal layer having a frame shape is provided, and a bonding material that bonds the first surface and the first metal layer. The bonding material is located in a region that includes the first metal layer and that is surrounded by the first metal layer in a plane perspective.

Abstract: An electronic component mounting package includes a metal substrate having a recessed portion and an insulation substrate having a mounting surface for an electronic component, in which the insulation substrate is located on a bottom surface of the recessed portion via a bonding material, and the bonding material is located within the insulation substrate when seen through an opening of the recessed portion in front perspective view.

Abstract: An electronic component mounting substrate includes: a metal base including a first surface and a recessed portion having a frame-like shape, the recessed portion opening to the first surface and including a bottom surface, an inner side surface, and an outer side surface; and an insulation base plate bonded via a bonding material to a position surrounded by the recessed portion on the first surface. A protective layer is provided on the inner side surface of the recessed portion, and on the bottom surface, the protective layer extending from the inner side surface to the outer side surface is not provided.

Abstract: A light emitting element mounting package includes a substrate, an insulating layer, and a metal layer. The insulating layer includes a through hole penetrating in a thickness direction and is provided on the substrate. The metal layer is disposed on the substrate in at least the through hole, and includes a protruding portion extending from the substrate along an inner wall of the through hole. The protruding portion has the shape of a connected body in which metal particles are connected together. The inner wall of the insulating layer includes, closer to the substrate, an inclined surface where the through hole becomes wider, and the protruding portion contacts the inclined surface.

Abstract: A joint body of the present disclosure includes a substrate including a base member having insulating properties and a metal layer positioned on a first main surface of the base member, a metal joint layer, and a metal member. The metal joint layer is positioned between the metal layer and the metal member of the substrate. The metal joint layer includes a nickel layer, a solder layer, and a composite layer containing a mix of nickel and solder. The nickel layer, the composite layer, and the solder layer are positioned in this order from the metal layer side to the metal member side. The nickel in the composite layer extends from the nickel layer in the thickness direction and forms protrusions and recesses.