PURPOSE: To enhance a high-density mounting operation of a package on a board without causing a lowering in the bonding strength and an increase in a cost by a method wherein a lead terminal for through hole use and a lead terminal for surface mounting use are employed and the package is mounted and arranged three-dimensionally with reference to the mounting board.

CONSTITUTION: Lead terminals 13, for through hole use, formed in a mixed manner and lead terminals 15 for surface mounting use are bonded to a mounting board 17; a package 11 is mounted and arranged three-dimensionally with reference to the mounting board 17. Accordingly, through holes in the mounting board 17 can be reduced; the practical bonding strength between the package 11 and the mounting board 17 can be satisfied sufficiently by the lead terminals 13 for through hole use. Thereby, a high-density mounting operation can be enhanced without causing a lowering in the bonding strength and an increase in a cost.