Planar magnetic element

• US 5,801,521 A
• Filed: 09/03/1996
• Issued: 09/01/1998
• Est. Priority Date: 05/31/1990
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tomita, Hiroshi, Sahashi, Masashi, Sato, Toshiro, Sawabe, Atsuhito, Mizoguchi, Tetsuhiko, Hasegawa, Michio
• Primary Examiner(s): Kozma, Thomas J.
• Application Number:
  US08/707,291
• Time in Patent Office: 728 Days
• Field of Search: 336/83, 336/212, 336/218, 336/232, 336/233, 336/234, 336/200, 232/282, 29/602.1, 29/606, 29/607
• US Class Current: 323/282
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 2017/0066 with a magnetic layer
• CPC Class Codes: H01F 2017/0086 on semiconductor substrate
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

Disclosed herein is a planar magnetic element comprising a substrate, a first magnetic layer arranged over the substrate, a first insulation layer arranged over the first magnetic layer, a planer coil formed of a conductor, having a plurality of turns, arranged over the first insulation layer and having a gap aspect ratio of at least 1, the gap aspect ratio being the ratio of the thickness of the conductor to the gap between any adjacent two of the turns, a second insulation layer arranged over the planar coil, and a second magnetic layer arranged over the second insulation layer. When used as an inductor, the planar magnetic element has a great quality coefficient Q. When used as a transformer, it has a large gain and a high voltage ratio. Since the element is small and thin, it is suitable for use in an integrated circuit, and can greatly contribute to miniaturization of electronic devices.

Claims

1. A planar magnetic element comprising:

a substrate;

a first magnetic layer arranged over said substrate;

a first insulation layer arranged over said first magnetic layer;

a planar coil formed of a conductor, having a plurality of turns, arranged over said first insulation layer;

wherein said first magnetic layer is a quadrilateral having four triangular sections with each section having an axis of easy magnetization which extends parallel to at least one of the four sides of the quadrilateral, wherein the axis of easy magnetization of each triangular section intersects at right angles with magnetic fluxes generated by said coil, and wherein said triangular sections each have a base corresponding to each side of said quadrilateral and wherein ones of said triangular sections having immediately adjacent bases have their respective axes of easy magnetization perpendicular to each other, whereby said magnetic layer has no readily saturated magnetic regions.

2. A DC-DC converter, comprising:

a switching element;

a planar magnetic element including a substrate and a first magnetic layer arranged over the substrate with a first insulation layer arranged over the first magnetic layer with the planar coil being formed of a conductor, having a plurality of turns, arranged over said first insulation layer; and

wherein said first magnetic layer is a quadrilateral having four triangular sections with each section having an axis of easy magnetization which extends parallel to at least one of the four sides of the quadrilateral, wherein the axis of easy magnetization of each triangular section intersects at right angles with magnetic fluxes generated by said coil, and wherein said triangular sections each have a base corresponding to each side of said quadrilateral and wherein ones of said triangular sections having immediately adjacent bases have their respective axes of easy magnetization perpendicular to each other, whereby said magnetic layer has no readily saturated magnetic regions.

3. A method of fabricating a planar magnetic element comprising the steps of:

providing a first magnetic layer arranged on a substrate;

providing a first insulation layer arranged over said first magnetic layer;

providing a planar coil formed of a conductor, having a plurality of turns, arranged over said first insulation layer and wherein said first magnetic layer is a quadrilateral having four triangular sections with each section having an axis of easy magnetization which extends parallel to at least one of the four sides of the quadrilateral, wherein the axis of easy magnetization of each triangular section intersects at right angles with magnetic fluxes generated by said coil, and wherein said triangular sections each have a base corresponding to each side of said quadrilateral and wherein ones of said triangular sections having immediately adjacent bases have their respective axes of easy magnetization perpendicular to each other, whereby said magnetic layer has no readily saturated magnetic regions.