Thin-film magnetic circuit board and magnetic head using the same

• US 5,390,062 A
• Filed: 03/14/1994
• Issued: 02/14/1995
• Est. Priority Date: 05/21/1991
• Status: Expired due to Fees

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Akai, Yayo, Matsuzawa, Soichiro, Terada, Nobuhiro
• Primary Examiner(s): Wolff, John H.
• Assistant Examiner(s): CAO, ALLEN T
• Application Number:
  US08/212,398
• Time in Patent Office: 337 Days
• Field of Search: 360/126, 360/123, 360/125, 360/113, 360/110, 360/121
• US Class Current: 360/125.33
• CPC Class Codes: G11B 5/127 Structure or manufacture of heads, e.g. inductive
• CPC Class Codes: G11B 5/17 Construction or disposition of windings

Abstract

A thin-film magnetic circuit board is disclosed which includes: a first and a second substrate formed of a magnetic material; a non-magnetic layer for bonding these substrates to each other; at least one coil formed from an electrically conductive film to provide a circuit pattern, each coil having a spiral shape and surrounding a predetermined blank portion of at least one of the first and second substrates; a pair of leads which are electrically connected to opposite ends of the circuit pattern formed by the coil(s); and a connector formed from a magnetic film, for magnetically connecting the first and second substrates. The connector is fixed to the predetermined blank portion of the first and/or second substrates. Also is disclosed a magnetic head including this thin-film magnetic circuit board.

Claims

1. A thin-film magnetic circuit board comprising:

first and second planar substrates each comprising a magnetic material;

a non-magnetic layer interposed between the entirety of side surfaces of said first and second planar substrates, for bonding said first and second planar substrates to each other in juxtaposition such that said substrates are arranged in the same plane;

a pair of coils formed on each of said first and second planar substrates, respectively, said coils being formed from an electrically conductive film to provide a circuit pattern on said first and second planar substrates, each coil having a spiral shape and surrounding a predetermined blank portion formed on a surface of each of said first and second planar substrates;

a pair of leads which are electrically connected to opposite ends of said circuit pattern formed by said coils, said pair of leads being formed on said first and second planar substrates, respectively; and

a connector formed of a magnetic film, for magnetically connecting said first and second planar substrates, said connector extending between said first and second planar substrates such that the connector is fixed to said predetermined blank portion of said first and second planar substrates.

2. A thin-film magnetic circuit board according to claim 1, wherein said pair of coils have respective ends as said opposite ends of said circuit pattern, each of which is located in said predetermined blank portion of the corresponding one of said first and second planar substrates.

3. A thin-film magnetic circuit board according to claim 2, further comprising a pair of electrically conductive layers formed on said first and second planar substrates, respectively, for electrically connecting said ends of said coils to corresponding end portions of said pair of leads.

4. A thin-film magnetic circuit board according to claim 1, wherein said first and second planar substrates comprise Ni--Zn ferrite.

5. A thin-film magnetic circuit board according to claim 1, wherein said non-magnetic layer comprises a glass material.

6. A thin-film magnetic circuit board according to claim 1, wherein said connector comprises a metallic magnetic material composed of Ni and Fe.

7. A magnetic head including a thin-film magnetic circuit board as defined in claim 1, wherein a magnetic gap is formed between said side surfaces of said first and second planar substrates, said first and second planar substrates cooperating with said connector to provide a single closed magnetic circuit including said magnetic gap.

8. A magnetic head including a thin-film magnetic circuit board as defined in claim 1, and a head core element comprising:

a third and a fourth substrate formed of a magnetic material;

a non-magnetic layer interposed between the entirety of side surfaces of said third and fourth substrates, for bonding said third and fourth substrates to each other, said non-magnetic layer partially defining a magnetic gap which is formed between said mutually abutting surfaces of said third and fourth substrates;

said magnetic circuit board having a first major surface on which said connector is formed and an opposed second major surface, said head core element being superposed on said second major surface of said thin-film magnetic circuit board, so that said third and fourth substrates are magnetically connected to said first and second substrates, respectively, said first, second, third and fourth substrates cooperating with said connector to provide a single closed magnetic circuit including said magnetic gap.

9. A magnetic head according to claim 8, wherein said magnetic gap extends in a direction perpendicular to a plane of said planar substrates.

10. A thin-film magnetic circuit board according to claim 1, wherein said pair of coils comprise one of copper and a copper alloy including Cu--Al.