7 138 188

7,138,188 Title:

Magnetic implement using magnetic metal ribbon coated with insulator

A magnetic ribbon or sheet is coated with an electrical insulator prior to formation of a magnetic implement. Manufacture of the magnetic implement is accomplished in a single process without a need for co-winding magnetic and insulator ribbons. Thermal property differences between the magnetic material and the insulator operate during heat treatment to enhance magnetic property modification of the implement.

What is claimed is:

1. A magnetic implement, comprising: a magnetic ribbon coated with an electrical insulator comprising SiO.sub.2 and having a thickness ranging from about 1 .mu.m to about 4.mu.m, magnetomechanical properties of the magnetic ribbon and thermal properties of the insulator being operable during heat treatment to reduce core loss of said implement.

2. The magnetic implement as recited by claim 1, wherein the ribbon comprises an amorphous metal magnetic alloy.

3. The magnetic implement as recited by claim 2, wherein the ribbon of the amorphous metal magnetic alloy is based on a zero or near-zero magnetostrictive amorphous alloy.

4. The magnetic implement as recited by claim 2, wherein the ribbon of amorphous metal magnetic alloy comprises an amorphous metal magnetic alloy with a positive magnetostriction.

5. The magnetic implement as recited by claim 1, wherein the electrical insulator has a dielectric constant below 10, wherein the electrical insulator is stable up to a temperature of above approximately 100.degree. C.

6. The magnetic implement as recited by claim 1, wherein the heat treatment of the magnetic implement reduces core loss of said implement to a level below a core loss of said implement with no heat treatment.

7. The magnetic implement as recited by claim 6, wherein the implement has a magnetic excitation direction and the heat-treatment is carried out with an applied field along a direction perpendicular to the magnetic excitation direction.

8. The magnetic implement as recited by claim 6, wherein the heat-treatment is carried out with an applied field of a plurality of kilo Gauss applied along a direction perpendicular to a magnetic excitation direction.

9. The magnetic implement as recited by claim 1, wherein the implement is a high frequency inductor.

10. The magnetic implement as recited by claim 9, wherein the magnetic inductor is an electrical choke.

11. The magnetic implement as recited by claim 9, wherein the magnetic inductor is an electrical energy storage media.

12. The magnetic implement as recited by claim 1, wherein the implement is a high frequency transformer.

13. The magnetic implement as recited by claim 12, wherein the transformer is a pulse transformer.

14. The magnetic implement as recited by claim 12, wherein the transformer is a signal transformer.

15. The magnetic implement as recited by claim 12, wherein the transformer is a current metering transformer.

16. A magnetic implement, comprising: a magnetic sheet coated with a SiO.sub.2 electrical insulator having a thickness ranging from about 1 .mu.m to about 4 .mu.m and heat-treated, wherein magnetomechanical properties of the magnetic sheet andthermal properties of the insulator are operable during heat treatment to reduce core loss of the implement.

17. A magnetic implement heat-treated to reduce core loss of the magnetic implement to a level below a core loss of an unheat-treated magnetic implement, comprising: a heat-treated magnetic implement fabricated from a SiO.sub.2 electricinsulator-coated magnetic ribbon, wherein the electrical insulator has a thickness ranging from about 1 .mu.m to about 4 .mu.m.

18. The magnetic implement as recited by claim 17, wherein the ribbon comprises an amorphous metal magnetic alloy with a positive magnetostriction.

19. The magnetic implement as recited by claim 17, wherein the electrical insulator has a dielectric constant below 10, and wherein the electrical insulator is stable up to a temperature of above approximately 100.degree. C.