Planar magnetic element

• US 6,593,841 B1
• Filed: 08/23/1996
• Issued: 07/15/2003
• 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: Sato, Toshiro, Hasegawa, Michio, Tomita, Hiroshi, Sahashi, Masashi, Sawabe, Atsuhito, Mizoguchi, Tetsuhiko
• Primary Examiner(s): MAI, ANH T
• Application Number:
  US08/701,918
• Time in Patent Office: 2,517 Days
• Field of Search: 336/83, 336/212, 336/218, 336/232, 336/234, 336/200
• US Class Current: 336/200
• 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 inductors for integrated circuits H01L28/10
• 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 semiconductor substrate;

at least one patterned conductive layer formed on said semiconductor substrate; and

a insulation layer formed on said at least one patterned conductive layer,

wherein said at least one patterned layer is patterned in the shape of a planar coil having a plurality of turns and having a gap aspect ratio greater than one, said gap aspect ratio being the ratio of the thickness of said at least one patterned conductive layer to a width of a gap between any adjacent two of said plurality of turns.

2. The planar magnetic element according to claim 1 wherein said gap has a first part filled with an insulating material and wherein a remaining part of said gap is a cavity which extends between turns of adjacent coils which form said gap.

3. The planar magnetic element according to claim 1, wherein said gap has a void.

4. The planar magnetic element according to claim 1, wherein said element is formed by at least one of a PVD (Physical Vapor Deposition) process, a CVD (Chemical Vapor Deposition) process, an epitaxial growth process and an electro-plating process.

5. A DC/DC converter, comprising:

a switching element; and

a planar magnetic element, wherein said planar magnetic element includes a semiconductor substrate, at least one patterned conductive layer formed on said semiconductor substrate; and

a insulation layer formed on said at least one patterned conductive layer, wherein said at least one patterned layer is patterned in the shape of a planar coil having a plurality of turns and having a gap aspect ratio greater than one, said gap aspect ratio being the ratio of the thickness of said at least one patterned conductive layer to a width of a gap between any adjacent two of said plurality of turns.

6. The DC/DC converter according to claim 5 wherein said gap has a first part filled with an insulation material and wherein a remaining part of said gap is a cavity which extends between turns of adjacent coils which form said gap.

7. The DC-DC converter according to claim 5, wherein said gap has a void.

8. The DC-DC converter according to claim 5, wherein said converter is formed by at least one of a PVD (Physical Vapor Deposition) process, a CVD (Chemical Vapor Deposition) process, an epitaxial growth process and an electro-plating process.

9. A planar magnetic element comprising:

a semiconductor substrate;

at least one patterned conductive layer formed on said semiconductor substrate; and

a insulation layer formed on said at least one patterned conductive layer,

wherein said at least one patterned layer is patterned in the shape of a planar coil having a plurality of turns and having a gap aspect ratio of from one to five, said gap aspect ratio being the ratio of the thickness of said at least one patterned conductive layer to a width of a gap between any adjacent two of said plurality of turns.

10. The planar magnetic element according to claim 9, wherein said gap has a void.

11. A DC-DC converter, comprising:

a switching element; and

a planar magnetic element, wherein said planar magnetic element includes a semiconductor substrate, at least one patterned conductive layer formed on said semiconductor substrate; and

a insulation layer formed on said at least one patterned conductive layer, wherein said at least one patterned layer is patterned in the shape of a planar coil having a plurality of turns and having a gap aspect ratio of from one to five, said gap aspect ratio being the ratio of the thickness of said at least one patterned conducive layer to a width of a gap between any adjacent two of said plurality of turns.

12. The DC-DC converter according to claim 11, wherein said gap has a void.