Composite-type magnetic core and method of manufacturing the same

摘要

Present inventions relate to a composite-type magnetic core and a method of manufacturing same. The composite-type magnetic core is made of a soft magnetic metal powder and an insulating binder having a lower electrical conductivity than the soft magnetic metal powder. The composite-type magnetic core has 10 parts per million (ppm) or more but 500 ppm or less of sodium oxide and 50 ppm or more but 3000 ppm or less of boron oxide. The sodium oxide and the boron oxide are concentrated in an inner layer near the surface of the magnetic core.