PURPOSE: To realize compactness of a core and a chip coil and to prevent disconnection of a lead wire by forming a core constituting a chip coil integrally by a press molding of powder raw material such as ceramics and ferrite and by forming a winding part thereof to a columnar body having a smooth surface.
CONSTITUTION: An upper surface 12a of a first lower punch 12 is made flush with an upper surface of a die 11 and a second lower punch 13 is fixed below. In the state, an upper space of the second lower punch 13 is filled with raw powder 15 consisting of ferrite, alumina or ceramics by a feeder. Then, an upper punch 14 is lowered and pressed downward with a lower surface 14a in contact with the upper surface 12a of the first lower punch 12. It is pressed down to a position wherein an upper surface 13a of the second lower punch 13 smoothly continues to a recessed part 12b of the first lower punch 12. In the process, the raw powder 15 is pressed and molded in a space enclosed with the recessed part 12b of the first lower punch 12, the upper surface 13a of the second lower punch 13 and a recessed part 14b of the upper punch 14.
Takayama Sanya
Naoki Kawai
