Multi-phasemagnetic element and production method therefor
A magnetic element for multi-phase is composed by burying a plurality of coils in a composite magnetic material such that a negative coupling of magnetic fluxes or a positive coupling of magnetic fluxes exists between at least two coils. This structure more miniaturizes inductors, or choke coils as the multi-phase magnetic element suitably used for application of a large current to many kinds of electronic equipment. Such multi-phase magnetic element has an excellent ripple current property.
1. A magnetic element for multi-phase, comprising
a coil with a winding axis in a straight line, the coil having a first end and a second end,
a composite magnetic material buried within the coil,
a first terminal provided intermediate the first end and the second end, the first terminal being exposed from the composite magnetic material,
a second terminal provided at the first end, the second terminal being exposed from the composite magnetic material, and
a third terminal provided at the second end, the third terminal being exposed from the composite magnetic material,
wherein (1) a first part of the coil is disposed between the first terminal and the second terminal, (2) a second part of the coil is disposed between the first terminal and the third terminal, and (3) a coupling exists between a magnetic flux of the first part and a magnetic flux of the second part.
2. The magnetic element for multi-phase according to claim 1 ,
wherein coupling of the magnetic fluxes is a negative coupling.
3. The magnetic element for multi-phase according to claim 1 , wherein DC resistant-values of the first part and the second part are respectively at most 0.05 Ω.
4. The magnetic element for multi-phase according to claim 1 , wherein the composite magnetic material contains soft magnetic alloy particles and an insulation binding agent.
5. The magnetic element for multi-phase according to claim 4 , wherein the insulation binding agent is a thermosetting resin.
6. The magnetic element for multi-phase according to claim 4 , wherein the soft magnetic alloying particles contain iron, nickel and cobalt of at least 90 weight % in total.
7. The magnetic element for multi-phase according to claim 4 , wherein the filling factor of the soft magnetic alloy particles is 65 to 90 volume %.
8. The magnetic element for multi-phase according to claim 4 , wherein the average diameter of the soft magnetic alloy particles is at least 1 μm and at most 100 μm.
9. The magnetic element for multi-phase according to claim 1 , wherein the coil is a punched coil integrally comprised of the second terminal and the third terminal.