PURPOSE: To lower the manufacturing cost of the title board and to improve the thermal conductivity of the title board by a method wherein the title board is provided with a hollowed-out part by means of which a package for an electronic component is brought into contact with, and bonded to, a heat sink directly and the surface of the heat sink in the hollowed-out part is covered with a solderable metal.

CONSTITUTION: A through hole is made in a copper foil on the surface of a double- sided glass epoxy copper-clad board; a panel copper plating operation is executed ; a circuit pattern is formed. Then, a window by means of which a package for an electronic component to be mounted is brought into direct contact with a heat sink is formed; a connection hole, for electrical connection use, by means of which the heat sink is used as a shielding layer is formed; a double-sided printed-circuit board is manufactured. A metal mask in which a part corresponding to the window in an aluminum sheet and to the connection hole has been opened is overlapped; copper is vapor-deposited. Then, a bonding sheet in which a part corresponding to the window and the connection hole has been hollowed out is pasted temporarily; it is thermally pressed. Then, a solder resist is printed on a face opposite to the heat sink of the double-sided printed-circuit board; an insulating coating layer is formed.