Abstract: A wiring substrate includes an electronic component and a core substrate. A through hole extends through the core substrate and accommodates the electronic component, which includes a main body and connection terminals. The main body includes opposing first side surfaces, opposing second side surfaces, and opposing third side surfaces. The connection terminals cover the first side surfaces. First projections project from walls of the through hole toward the first side surfaces. Each first projection includes a distal end that contacts one of the connection terminals. Second projections project from walls of the through hole toward the second side surfaces. The opposing second projections include distal ends spaced apart by a distance longer than the distance between the second side surfaces and shorter than the distance between two farthest points on a periphery of each first side surface.

Abstract: A wiring substrate includes an electronic component and a core substrate. A through hole extends through the core substrate and accommodates the electronic component, which includes a main body and connection terminals. The main body includes opposing first side surfaces, opposing second side surfaces, and opposing third side surfaces. The connection terminals cover the first side surfaces. First projections project from walls of the through hole toward the first side surfaces. Each first projection includes a distal end that contacts one of the connection terminals. Second projections project from walls of the through hole toward the second side surfaces. The opposing second projections include distal ends spaced apart by a distance longer than the distance between the second side surfaces and shorter than the distance between two farthest points on a periphery of each first side surface.

Abstract: A semiconductor package uses no thermosetting adhesive for mounting a heat slug thereon, which adhesive requires a strict control during the storage and the production thereof. A semiconductor package comprises a circuit board having respective surfaces and an opening; a conductive layer formed on one of the surfaces of the circuit board so that the conductive layers are retracted from a peripheral edge of the opening by a certain distance; a heat slug attached to the one surface of the circuit board by means of solder so that the opening is closed at the one surface and opened at the other surface to form a cavity within which a semiconductor element mounting area is defined.

Abstract: A semiconductor package uses no thermosetting adhesive for mounting a heat slug thereon, which adhesive requires a strict control during the storage and the production thereof. A semiconductor package comprises a circuit board having respective surfaces and an opening; a conductive layer formed on one of the surfaces of the circuit board so that the conductive layers are retracted from a peripheral edge of the opening by a certain distance; a heat slug attached to the one surface of the circuit board by means of solder so that the opening is closed at the one surface and opened at the other surface to form a cavity within which a semiconductor element mounting area is defined; and the heat slug is provided with a groove along a periphery of the semiconductor element mounting area and adjacent the peripheral edge of the opening.