Magnetic element and method of manufacturing magnetic element
There are provided a magnetic element capable of enhancing magnetic permeability of a magnetic member, improving a direct current superposition characteristic, and improving production efficiency and a method of manufacturing the magnetic element. The magnetic element includes a coil ( 30 ) formed of a conductor having an insulating film, a first core member ( 20 ) constituted of insulative soft magnetic ferrite and covering the coil ( 30 ), and a second core member ( 50 ) having soft magnetic metal powder as material and surrounded by the first core member ( 20 ). Furthermore, the magnetic element includes a third core member ( 40 ) which has soft magnetic metal powder as material and a higher filling ratio of the soft magnetic metal powder than the second core member 50 and is surrounded by the first core member ( 20 ).
1. A magnetic element, comprising:
a coil having two end portions
a ferrite core providing a bottom portion and side walls to receive said coil; said ferrite core having two cut-out portions in said side walls; said cut-out portions not extending the height of said side walls and the height of each cut-out portion from said bottom portion is equal;
a cured paste portion consisting of magnetic metal powder and resin mainly, and filled into said ferrite core to bury said coil, wherein said cured paste portion does not extend outside of said ferrite core through said cut-out portions and
terminal electrodes covering each corresponding end portions formed near each corresponding cut-out portions and on the outside of said ferrite core so as not to contact said cured paste portion directly;
wherein each of said end portions of said coil are placed at the bottom portion of said cut-out portions and extend out of said core through the cut-out portions to connect with said terminal electrodes;
and said upper surface of said ferrite core and an upper surface of said cured paste portion form a flat surface.
2. The magnetic element according to claim 1 , wherein said coil is formed by patterning metal on a heat resistant resin film.
3. The magnetic element according to claim 1 , wherein said cured paste portion does not exist between windings of said coil.
4. An magnetic element according to claim 1 , wherein said terminal electrodes are plated for preventing solder corrosion and securing solder wetting.
5. An magnetic element according to claim 1 wherein said terminal electrodes have thermosetting resin as material, and said terminal electrodes are formed by heating and curing the thermosetting resin containing Ag.