EMI filters

• US 6,778,034 B2
• Filed: 05/07/2002
• Issued: 08/17/2004
• Est. Priority Date: 05/07/2002
• Status: Expired due to Fees

• Current Assignee: G.M.W.T. Global Micro Wire Technologies Ltd.
• Original Assignee: G.M.W.T. Global Micro Wire Technologies Ltd.
• Inventors: Nir, Shlomo, Axelrod, Alexander, Povolotski, Konstantin
• Primary Examiner(s): Tokar, Michael
• Assistant Examiner(s): Nguyen, Linh V
• Application Number:
  US10/139,749
• Publication Number:
  US 20030210104A1
• Time in Patent Office: 833 Days
• Field of Search: 333/182, 333/185, 333/12, 333/184, 333/186, 333/202, 333/204, 333/206, 174/122.V, 174/120.V, 174/121, 174/124, 174/122, 174/128.1, 174/121.V, 174/122.G
• US Class Current: 333/12
• CPC Class Codes: H01F 17/06 with core substantially closed in itself, e.g. toroid
• CPC Class Codes: H01F 3/06 made from wires

Abstract

An electromagnetic interference filter, including a core, having: at least one electrically conductive signal or power-insulated lead, at least one first layer surrounding the lead, made of glass-coated microwire, serving as a magnetic absorbent material, a tubular conductive material surrounding the first layer, and a substrate on which the core is mounted, the substrate is configured as a planar body having a top, a bottom and side surfaces, portions of the top and bottom surfaces are covered with electrically conductive material serving as signal and ground terminals and making electrical contact with the tubular conductive material of the core.

Claims

1. An electromagnetic interference filter, comprising:

a core having;

at least one electrically conductive signal or power-insulated lead;

at least one first layer made of glass-coated metal microwire surrounding said lead and serving as a magnetic absorbent material; and

a tubular conductive material surrounding said first layer; and

a substrate on which said core is mounted, said substrate being configured as a planar body having a top, a bottom and side surfaces, portions of said top and bottom surfaces being covered with an electrically conductive material serving as signal and ground terminals and making electrical contact with the tubular conductive material.

2. The filter as claimed in claim 1, wherein said glass-coated metal microwire is wound around said lead in a direction substantially perpendicular to an axis of said lead.

3. The filter as claimed in claim 1, wherein a diameter of said glass-coated metal microwire is between 1×

10<sup>−

6</sup> m and 30×

10<sup>−

6</sup> m.

4. The filter as claimed in claim 1, wherein said metal comprises a (CoMe) Bsi alloy, wherein Me is a metal selected from the group consisting of Fe, Mn, Ni and Cr.

5. The filter as claimed in claim 1, further comprising an insulating second layer, disposed between said first layer and said conductive material, providing physical and electrical barriers and an increase in the dielectric strength of said core.

6. The filter as claimed in claim 5, wherein a thickness of said insulating second layer is in the range of between 10 to 200 μ

m.

7. The filter as claimed in claim 1, wherein said first layer has a Length of between 1 to 90 mm.

8. The filter as claimed in claim 1, wherein side surfaces of said substrate are at least partially coated with conductive material.

9. The filter as claimed in claim 1, wherein the electrically conductive material on the top surface of said substrate is interconnected to the electrically conductive material on the bottom surface thereof by holes passing through said substrate, said holes being lined with conductive material.

10. The filter as claimed in claim 1, wherein said substrate further comprises electrical terminals for interconnection with said lead.

11. The filter as claimed in claim 1, wherein said core has a cylindrical, a Z-shaped, or a spiral configuration.

12. The filter as claimed in claim 1, further comprising a housing made of a non-metallic material.

13. An electromagnetic interference filter, comprising:

first conducting means for conducting a first signal;

absorbing means for absorbing a magnetic field, said absorbing means including at least one first layer-made of glass-coated metal microwire surrounding said conducting means;

second conducting means for conducting a second signal and surrounding said first layer; and

mounting means for mounting said first conducting means, said absorbing means, and said second conducting means, said mounting means configured as a planar body having a top, a bottom and side surfaces, portions of said top and bottom surfaces being covered with an electrically conductive material serving as signal and ground terminals and making electrical contact with the second conducting means.

14. The filter as claimed in claim 13, wherein said first layer comprises glass-coated amorphous metal microwire, said glass-coated metal microwire includes a core including a soft magnetic alloy.

15. The filter as claimed in claim 14, wherein said glass-coated metal microwire is wound around said first conducting means in a direction substantially perpendicular to an axis of said lead.

16. The filter as claimed in claim 14, wherein a diameter of said glass-coated metal microwire is between 1×

10<sup>−

6</sup> m and 30×

10<sup>−

6</sup> m.

17. The filter as claimed in claim 14, wherein said core comprises a (CoMe) Bsi alloy, wherein Me is a metal selected from the group consisting of Fe, Mn, Ni and Cr.

18. The filter as claimed in claim 13, further comprising an insulating second layer, disposed between said first layer and said second conducting means configured to provide physical and electrical barriers and an increase in the dielectric strength of said first conducting means, said absorbing means, and said second conducting means.

19. The filter as claimed in claim 18, wherein a thickness of said conducting means is in the range of between 10 and 200 μ

m.

20. The filter as claimed in claim 13, wherein a length of said first layer is between 1 and 90 mm.

21. The filter as claimed in claim 13, wherein side surfaces of said substrate are at least partially coated with a conductive material.

22. The filter as claimed in claim 13, wherein the electrically conductive material on the top surface of said substrate is interconnected to the electrically conductive material on the bottom surface thereof by holes passing through said mounting means, said holes being lined with conductive material.

23. The filter as claimed in claim 13, wherein said mounting means further comprises electrical terminals for interconnection with said first conducting means.

24. The filter as claimed in claim 13, wherein said first conducting means, said absorbing means, and said second conducting means each have a cylindrical, a Z-shaped, or a spiral configuration.

25. The filter as claimed in claim 13, further comprising a housing made of non-metallic material.

26. An electromagnetic interference filter, comprising:

a core, having;

at least one electrically conductive signal or power-insulated lead;

at least one first layer surrounding said lead, made of glass-coated microwires, serving as a magnetic absorbent material;

a tubular conductive material surrounding said first layer, and

a substrate on which said core is mounted, said substrate being configured as a planar body having a top, a bottom and side surfaces, portions of said top and bottom surfaces being covered with electrically conductive material serving as signal and ground terminals and making electrical contact with the tubular conductive material of said core,

wherein said first layer comprises glass-coated amorphous metal microwires, said microwires having a core made of soft magnetic alloy.

27. The filter as claimed in claim 26, wherein said microwires are wound around said lead in a direction substantially perpendicular to the axis of said lead.

28. The filter as claimed in claim 26, wherein the diameter of said microwires is between 1×

10<sup>−

6</sup> and 30×

10<sup>−

6</sup> m.

29. The filter as claimed in claim 26, wherein said core comprises a (CoMe) Bsi alloy, wherein Me is a metal selected from the group consisting of Fe, Mn, Ni and Cr.