A surface-mount microconverter is formed by mounting a microinductor chip and
a
semiconductor integrated circuit chip on a circuit board. Stud terminals are arranged
on the circuit board and the microinductor chip is supported on the stud terminals,
and the microinductor chip and the semiconductor integrated circuit chip are superposed
on the circuit board. The microconverter has an improved ability and is small and
thin. The microconverter includes an effective laminated magnetic-core inductor.
The inductor comprises a helical coil formed by uniting alternately superposed
insulating magnetic layers and conductive pattern layers, and an annular closed
magnetic path formed by the insulating magnetic layers and defining a magnetic
field created by the coil. The inductor can be miniaturized in a thin chip, and
a wide range in which magnetic flux density varies linearly can be secured by balancing
a closed magnetic path for a magnetic field created by the coil.
