COMPOSITE MAGNETIC MATERIAL AND METHOD OF MANUFACTURING THE SAME
First Claim
1. A composite magnetic material for an inductor, in which a soft magnetic metal powder is bonded with a non-magnetic material, whereinthe non-magnetic material comprises a first binder comprising an organic resin which is added to and mixed with the soft magnetic metal powder, as a compacting additive, and a second binder that is impregnated into a compact, which is obtained by compacting the soft magnetic metal powder added with the first binder as a binder, after heat treatment of the compact, and is heat-cured;
- the organic resin comprises one or two or more selected from the group consisting of polyvinyl butyral (PVB), polyvinyl alcohol (PVA), methyl cellulose (MC), water-soluble acrylic binder (AC), paraffin, glycerin and polyethylene glycol, and has granulatability, compactibility, shape retainability and thermal decomposability, andthe soft magnetic metal powder contains 40% by the so mass or more (including 100%) of spherical particles which the ratio L2/L1 between a perimeter L1 of a particle cross-section in the two dimensional plane view and a perimeter L2 of a circle having equivalent cross-sectional area is 0.5 or more.
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Accused Products
Abstract
Certain embodiments provide a composite magnetic material for an inductor, wherein a non-magnetic material contains a first binder as a compacting additive, and is added to and mixed with the soft magnetic metal powder, and a second binder that is impregnated to a compact as a binder after the heat treatment of the compact obtained by adding the first binder to the soft magnetic metal powder and compacting it, and the soft magnetic metal powder contains 40% by mass or more (including 100%) of spherical particles of which the ratio L2/L1 between a perimeter L1 of a particle cross-section in the two dimensional plane view and a perimeter L2 of a circle having equivalent cross-sectional area is 0.5 or more.
49 Citations
20 Claims
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1. A composite magnetic material for an inductor, in which a soft magnetic metal powder is bonded with a non-magnetic material, wherein
the non-magnetic material comprises a first binder comprising an organic resin which is added to and mixed with the soft magnetic metal powder, as a compacting additive, and a second binder that is impregnated into a compact, which is obtained by compacting the soft magnetic metal powder added with the first binder as a binder, after heat treatment of the compact, and is heat-cured; - the organic resin comprises one or two or more selected from the group consisting of polyvinyl butyral (PVB), polyvinyl alcohol (PVA), methyl cellulose (MC), water-soluble acrylic binder (AC), paraffin, glycerin and polyethylene glycol, and has granulatability, compactibility, shape retainability and thermal decomposability, and
the soft magnetic metal powder contains 40% by the so mass or more (including 100%) of spherical particles which the ratio L2/L1 between a perimeter L1 of a particle cross-section in the two dimensional plane view and a perimeter L2 of a circle having equivalent cross-sectional area is 0.5 or more. - View Dependent Claims (2, 3, 4, 5, 6, 7, 19)
- the organic resin comprises one or two or more selected from the group consisting of polyvinyl butyral (PVB), polyvinyl alcohol (PVA), methyl cellulose (MC), water-soluble acrylic binder (AC), paraffin, glycerin and polyethylene glycol, and has granulatability, compactibility, shape retainability and thermal decomposability, and
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8. A method of producing a composite magnetic material for an inductor, in which a soft magnetic metal powder is bonded with a non-magnetic material, comprising:
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(a) preparing a soft magnetic metal powder that contains 40% by mass or more (including 100%) of spherical particles of which the ratio L2/L1 between perimeter L1 of a particle cross-section in the two dimensional plane view and a perimeter L2 of a circle having equivalent cross-sectional area is 0.5 or more, and mixing the soft magnetic metal powder with first binder as a compacting additive in a predetermined ratio, comprising one or two or more organic resins selected from the group consisting of polyvinyl butyral (PVB), polyvinyl alcohol (PVA), methyl cellulose (MC), water-soluble acrylic binder (AC), paraffin, glycerin and polyethylene glycol, wherein the organic resin has granulatability, compactibility, shape retainability and thermal degradability; (b) compacting the mixture obtained in step (a) into a desired shape; (c) heat-treating the compact obtained in step (b) under predetermined conditions, and heat-degrading the organic resin to form voids between the particles of the soft magnetic metal powder; and (d) impregnating the compact after the heat treatment with a second binder comprising one or two or more selected from the group consisting of a silicone resin, an organic resin and a water glass under predetermined conditions, whereby filling the voids formed in step (c) with the second binder, and then heating the compact to cure the second binder. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20)
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Specification