Abstract: An electronic component unit manufacturing method includes: preparing a circuit board including a heat generating element mounted thereon and a bonding metal foil layer formed thereon, a heat transfer board including an insulative layer formed on one face thereof and a heat transfer metal foil layer formed on the insulative layer, and a heat sink; applying a cream solder to form a solder layer on the board bonding metal foil layer or the heat transfer metal foil layer; superimposing the bonding metal foil layer and the heat transfer metal foil layer with each other via the solder layer; re-melting the solder layer to solder the bonding metal foil layer and the heat transfer metal foil layer; and superimposing the other face of the heat transfer board with the heat sink to thereby assemble the circuit board with the heat sink via the heat transfer board.

Abstract: An electronic component unit manufacturing method includes: preparing a circuit board including a heat generating element mounted thereon and a bonding metal foil layer formed thereon, a heat transfer board including an insulative layer formed on one face thereof and a heat transfer metal foil layer formed on the insulative layer, and a heat sink; applying a cream solder to form a solder layer on the board bonding metal foil layer or the heat transfer metal foil layer; superimposing the bonding metal foil layer and the heat transfer metal foil layer with each other via the solder layer; re-melting the solder layer to solder the bonding metal foil layer and the heat transfer metal foil layer; and superimposing the other face of the heat transfer board with the heat sink to thereby assemble the circuit board with the heat sink via the heat transfer board.

Abstract: According to embodiments, there is provided an electronic component unit, including: a circuit board including: a heat generating element that generates a heat; and a bonding metal foil layer formed on a face thereof; a heat transfer board including: a board body having a thermal conductivity higher than that of the circuit board; an insulative layer formed on a first face of the board body; and a heat transfer metal foil layer formed to cover the insulative layer; and a heat sink, wherein the circuit board is assembled with the heat sink via the heat transfer board such that (1) the heat transfer metal foil layer is soldered to the bonding metal foil layer and (2) the second face of the board body is superimposed on the heat sink.