Soft magnetic powder containing oxide insulation film, manufacturing method thereof, and powder core produced therefrom

1 . Soft magnetic powder, comprising:

metal powder;

an oxide insulation film coating a surface of metal powder particles; and

a polymer coating layer positioned on an outer surface of the oxide insulation film,

wherein the metal powder particles include one or more selected from pure iron or an iron-based alloy, and

the oxide insulation film includes an oxide of a component constituting the metal powder particles,

wherein a thickness of the polymer coating layer is in a range of 10 nm to 300 nm.

2 . The soft magnetic powder of claim 1 , wherein:

a thickness of the oxide insulation film is in a range of 5 nm to 300 nm.

3 . A method of manufacturing soft magnetic powder, comprising:

preparing a powder mixture sample by mixing a metal powder containing at least one selected from pure iron or an iron-based alloy with an anti-sintering agent; and

forming an oxide insulation film on the metal powder particles,

wherein the forming of the oxide insulation film includes heating the powder mixture and oxidizing the soft magnetic metal powder with a certain amount of oxygen in a sealed container at a predetermined temperature,

wherein the forming of the oxide insulation film is performed while stirring the powder mixture sample.

4 . The method of claim 3 , wherein:

the anti-sintering agent is at least one selected from MgO, CaO, Al 2 O 3 , SiO 2 , TiO 2 and ZrO 2 or at least one selected from LiOH, Mg(OH) 2 , Ca(OH) 2 , Sr(OH) 2 , Ba(OH) 2 , Mn(OH) 4 , and Ti(OH) 4 .

5 . The method of claim 3 , wherein:

the amount of anti-sintering agent in the powder mixture is in a range of 0.05 wt % to 1.00 wt % based on a weight of the metal powder.

6 . The method of claim 3 , wherein:

the oxidizing of the soft magnetic metal powder with the certain amount of oxygen in the sealed container is performed at a temperature in a range of 300° C. to 1100° C.

7 . The method of claim 3 , wherein:

the heating of the powder mixture is performed in an inert gas atmosphere.

8 . The method of claim 3 , wherein:

the oxidizing of the metal powder with the certain amount of oxygen in the sealed container includes controlling a thickness of the oxide insulation film formed on the surface of the metal powder by controlling the consumption of oxygen supplied to the sealed reactor.

9 . The method of claim 8 , wherein:

the amount of oxygen consumed is adjusted in a range of 4.5*10 −6 to 9.0*10 −4 moles per gram of the metal powder based on O 2 .

10 . The method of claim 3 , further comprising:

after forming the oxide insulation film on the metal powder particles, forming a polymer coating layer on the surface of the formed oxide insulation film.

11 . A powder core composed of the soft magnetic powder of claim 1 .

12 . The powder core of claim 11 , wherein the powder core is produced by:

pressing the soft magnetic powder to form a molded body; and

annealing heat-treating the molded body in an atmosphere of nitrogen, hydrogen, or nitrogen-hydrogen mixed gas.

13 . The powder core of claim 12 , wherein:

the annealing heat-treating is performed at a temperature in a range of 600° C. to 1100° C.

when the oft magnetic powder contains at least one of Al and Si.