Composite magnetic material and coil component using same
A composite magnetic material is provided that includes a resin and first magnetic particles provided inside the resin. Each of the first magnetic particles includes a first core comprising a metal magnetic material, and an insulating film that covers the first core. The first core has a substantially flat shape having a short axis and a long axis. A thickness of the insulating film in the long axis direction of the first core is smaller than a thickness of the insulating film in the short axis direction of the first core. In addition, a coil component is provided that includes the composite magnetic material in an element body of the coil component.
1. A composite magnetic material comprising:
a resin; and
first magnetic particles provided inside the resin;
wherein
each of the first magnetic particles includes a first core comprising a metal magnetic material, and an insulating film that entirely covers the first core,
the first core has a substantially flat shape having a short axis extending at a midpoint of the first core and a long axis perpendicular to the short axis, and
a thickness of the insulating film in a long axis direction of the first core is smaller than a thickness of the insulating film in a short axis direction of the first core.
2. The composite magnetic material according to claim 1 , wherein the thickness of the insulating film in the long axis direction of the first core is around 0.05 nm-50 nm.
3. The composite magnetic material according to claim 1 , further comprising:
second magnetic particles;
wherein
each of the second magnetic particles includes a second core,
the second core has a substantially flat shape having a short axis and a long axis,
a length of the second core in a long axis direction of the second core is smaller than a length of the first core in the long axis direction of the first core, and
a length of the second core in a short axis direction of the second core is smaller than a length of the first core in the short axis direction of the first core.
4. The composite magnetic material according to claim 3 , wherein an aspect ratio of the second core is around ¼-½ an aspect ratio of the first core.
5. The composite magnetic material according to claim 1 , further comprising:
third magnetic particles;
wherein
each of the third magnetic particles includes a third core and are spherical, and
an average particle diameter of the third cores is smaller than the length of the first cores in the short axis direction of the first cores.
6. The composite magnetic material according to claim 5 , wherein the average particle diameter of the third cores is around 0.2-0.8 times the length of the first cores in the short axis direction of the first cores.
7. A coil component comprising:
an element body that includes the composite magnetic material according to claim 1 ;
a coil that is provided inside the element body and is wound in a substantially spiral shape; and
an outer electrode that is provided on the element body and is electrically connected to the coil.
8. The coil component according to claim 7 , wherein
the element body includes
a first magnetic part that is arranged on one side of the coil in an axis direction of the coil, and
a second magnetic part that is arranged on another side of the coil in the axis direction of the coil,
at least one of the first magnetic part and the second magnetic part includes the composite magnetic material, and
the first magnetic particles are arrayed such that the long axes of the first cores included in the composite magnetic material intersect the axis direction of the coil.
9. The coil component according to claim 8 , wherein at least part of the outer electrode is located on an end surface, in the axis direction of the coil, of the magnetic part that includes the composite magnetic material.
10. The coil component according to claim 7 , wherein
the magnetic part that includes the composite magnetic material has a plurality of layers stacked in the axis direction of the coil, and
the first magnetic particles are included in a layer that is closest to the coil among the plurality of layers.
11. The coil component according to claim 7 , wherein
the element body includes a third magnetic part that is arranged inside the coil,
the third magnetic part includes the composite magnetic material, and
the first magnetic particles included in the composite magnetic material are arrayed such that the short axes of the first cores of the first magnetic particles intersect the axis direction of the coil.
12. The coil component according to claim 7 , wherein the coil is an α wound coil or an edgewise wound coil.
13. The composite magnetic material according to claim 2 , further comprising:
second magnetic particles;
wherein
each of the second magnetic particles includes a second core,
the second core has a substantially flat shape having a short axis and a long axis,
a length of the second core in a long axis direction of the second core is smaller than a length of the first core in the long axis direction of the first core, and
a length of the second core in a short axis direction of the second core is smaller than a length of the first core in the short axis direction of the first core.
14. The composite magnetic material according to claim 2 , further comprising:
third magnetic particles;
wherein
each of the third magnetic particles includes a third core and are spherical, and
an average particle diameter of the third cores is smaller than the length of the first cores in the short axis direction of the first cores.
15. The composite magnetic material according to claim 3 , further comprising:
third magnetic particles;
wherein
each of the third magnetic particles includes a third core and are spherical, and
an average particle diameter of the third cores is smaller than the length of the first cores in the short axis direction of the first cores.
16. A coil component comprising:
an element body that includes the composite magnetic material according to claim 2 ;
a coil that is provided inside the element body and is wound in a substantially spiral shape; and
an outer electrode that is provided on the element body and is electrically connected to the coil.
17. A coil component comprising:
an element body that includes the composite magnetic material according to claim 3 ;
a coil that is provided inside the element body and is wound in a substantially spiral shape; and
an outer electrode that is provided on the element body and is electrically connected to the coil.
18. The coil component according to claim 8 , wherein
the magnetic part that includes the composite magnetic material has a plurality of layers stacked in the axis direction of the coil, and
the first magnetic particles are included in a layer that is closest to the coil among the plurality of layers.
19. The coil component according to claim 9 , wherein
the magnetic part that includes the composite magnetic material has a plurality of layers stacked in the axis direction of the coil, and
the first magnetic particles are included in a layer that is closest to the coil among the plurality of layers.
20. The coil component according to claim 8 , wherein the coil is an α wound coil or an edgewise wound coil.