Improved temperature-stable soft magnetic powder

Abstract

A soft magnetic powder coated with a silicon coating, wherein the silicon coating is of formula (I) and Si x B y O 2x+1.5y (I) (wherein x = 0.5 to 1.5, y = 1.0 to 1.5) A soft magnetic powder coated with a silicon coating is obtained after heat treatment at a temperature in the range of 350 to 700°C, with an average particle size D of 0.5 to 250 μm. 50 A soft magnetic powder coated with a silicon coating, having the following properties.

Claims

1. A soft magnetic powder coated with a silicon coating, wherein the silicon coating is of formula (I) Si ｘ B ｙ O ２ｘ＋１．５ｙ (I) (In the formula, x=0.5~1.5, y=1.0~1.5) A soft magnetic powder having a silicon coating is obtained after heat treatment at a temperature in the range of 350 to 700°C, with an average particle size D of 0.5 to 250 μm. ５０ Having, Soft magnetic powder coated with a silicon coating.

2. A soft magnetic powder coated with a silicon coating according to claim 1, wherein the silicon coating has an average thickness of 2 to 100 nm as measured by transmission electron microscopy.

3. A soft magnetic powder coated with a silicon coating according to claim 1 or 2, wherein the silicon coating has a halogen content of less than 10.0 ppm, preferably less than 0.1 ppm.

4. The boron component of the coating is SiO ２ Embedded within the matrix, and / or SiO ２ A soft magnetic powder coated with a silicon coating according to any one of claims 1 to 3, which is bonded to the surface of the coating.

5. Particle size D is 1 to 50 μm, preferably 2 to 20 μm. ５０ A soft magnetic powder coated with a silicon coating according to any one of claims 1 to 4, having the following characteristics.

6. A method for obtaining a soft magnetic powder coated with a silicon coating according to any one of claims 1 to 5, a) Soft magnetic powder, silicon precursor and formula II BX ３ (II) (wherein, X is H, OH, linear or branched C １ ~C ６ alkyl, or linear or branched OC １ ~C ６ selected from alkyl) A step of mixing with at least one boron compound, b) A step of subjecting the mixture from step a) to heat treatment at a temperature in the range of 350 to 700°C to obtain a soft magnetic powder coated with a silicon coating. Methods that include...

7. The method according to claim 6, wherein the heating in step b) is carried out for a period of 0.5 to 12 hours.

8. The method according to claim 6 or 7, wherein the silicon precursor is a silicon alkoxide, preferably selected from tetramethyl orthosilicate (TMOS), tetraethyl orthosilicate (TEOS), tetrapropyl orthosilicate, tetraisopropyl orthosilicate, or a mixture thereof.

9. The method according to any one of claims 6 to 8, wherein the boron compound is selected from trihydridoborane, boric acid, boronic acid, trimethyl borate, triethyl borate, triisopropyl borate, tributyl borate, tri-tert-butyl borate, or a mixture thereof.

10. The method according to any one of claims 6 to 9, wherein a soft magnetic powder is mixed with a silicon precursor, and a boron compound is added after the soft magnetic powder has been at least partially treated with the silicon precursor.

11. The method according to any one of claims 6 to 10, wherein the boron compound has a solubility in ethanol at 0°C of at least 15 wt%, preferably at least 20 wt%.

12. The method according to any one of claims 6 to 11, wherein the mixture in step a) has 0.01 to 1.5 moles of an organic borate compound per 1 kg of soft magnetic powder.

13. The method according to any one of claims 6 to 12, wherein the mixture in step a) has a molar ratio of the boron compound to the silicon precursor in the range of 1:5 to 5:

1.

14. A method for using a soft magnetic powder according to any one of claims 1 to 5 or a soft magnetic powder obtained from the method according to any one of claims 6 to 13 for the manufacture of electronic components.

15. An electronic component comprising a soft magnetic powder according to any one of claims 1 to 5 or a soft magnetic powder obtained by the method according to any one of claims 6 to 13.

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