Composite magnetic head structure and process for manufacturing the same

Claim 2

A composite magnetic head structure comprising: a front core (16) consisting of non-magnetic spacing means (10) for separating a read/write magnetic flux path from an erase magnetic flux path and first and second core chips (12, 14) adhered together with the spacing means (10) interposed therebetween, at the central portion of said first core chip (12) being formed a read/write gap (28) which is parallel to the longitudinal direction of said spacing means (10) and whose width is defined by first and second notches (30, 32) extending from respective side edges of said first core chip (12), and erase gaps (34, 36) being formed in said second core chip (14) which extend between the side edges of said second core chip (14) parallel to the longitudinal direction of said spacing means and whose widths are defined by a third notch (38) formed at a position substantially corresponding to said read/write gap (28) as viewed along the direction of arrangement of said first and second core chips (12, 14); a back core (18) adhered to said front core (16) forming said read/write magnetic flux path and said erase magnetic flux path, said back core (18) having a read/write magnetic leg (20) forming said read/write magnetic flux path, an erase leg (22) forming said erase magnetic flux path, and a common leg (56) forming both said magnetic flux paths and having a fourth notch (58) for separating said magnetic flux paths formed at a position corresponding to said spacing means; a read/write winding (24) which is wound on said read/write leg (20); and an erase winding (26) which is wound on said erase leg (22).

Claim 3

A head structure according to claim 1, wherein the width of said read/write gap (28) is substantially the same as the width of said third notch (38) defining the widths of said erase gaps (34, 36).

Claim 4

A head structure according to claim 1, wherein the width of said third notch (38) is shorter than the width of said read/write gap (28), and said erase gaps (34, 36) extending from said respective side edges partially overlap said read/write gap (28) as viewed along said direction of arrangement.

Claim 5

A head structure according to claim 1, wherein said first core chip (12) comprises first and second chip elements (40, 42) arranged in opposition to each other, and said first and second notches (30, 32) and said read/write gap (28) are formed between the opposing surfaces of said first and second chip elements (40, 42).

Claim 6

A head structure according to claim 1, wherein said second core chip (14) comprises first and second chip elements (48, 50) arranged in opposition to each other, and said third notch (38) and said erase gaps (34, 36) are formed between the opposing surfaces of said first and second chip elements (48, 50). -

Claim 7

A head structure according to claim 4, wherein adhering means (46) for adhering said first and second chip elements (40, 42) is filled inside said first and second notches (30, 32) to the surfaces of said first and second chip elements (40, 42).

Claim 8

A head structure according to claim 5, wherein adhering means (53) for adhering said first and second chip elements (48, 50) is filled inside said third notch (38) to the surfaces of said first and second chip elements (48, 50).

Claim 9

A head structure according to claim 6 or 7, wherein said adhering means (46, 53) is a hard glass having a low softening point.

Claim 10

A process for manufacturing a composite magnetic head structure comprising the steps of: forming in a first magnetic plate (66) and a second magnetic plate (64) a plurality of parallel notches (76a, 76b, 76c, 76d, 76e) at a predetermined pitch and of a predetermined width defining a track width; forming a groove (72, 74) defining a gap depth in said first magnetic plate (66) in a direction perpendicular to said plurality of parallel notches (76a - 76e); adhering said first and second magnetic plates (66, 64) in such a manner that a non-magnetic material layer (78) is interposed therebetween and said plurality of parallel notches (76a - 76e) in said respective magnetic plates (66, 64) oppose each other to form a plurality of parallel holes (77a - 77e); opposing and adhering two assemblies (90 1 , 90 2 ) formed by said adhering step in such a manner that non-magnetic spacing means (92, 94, 96) is interposed therebetween and said plurality of parallel holes (77a - 77e) of said assemblies (90 1 , 90 2 ) are mutually shifted by half the pitch; cutting the obtained adhered assemblies into a plurality of assembly blocks (104) along planes extending perpendicular to said spacing means (92, 94, 96) and perpendicular to the longitudinal direction of said plurality of holes (77a - 77e); cutting the obtained assembly block into a plurality of first assembly chips (104a, 104b, 104c, 104d) along lines (124 1 , 124 2 , 124 3 ) passing the middle points between said holes (77a - 77e) of one assembly (90 1 ) and perpendicular to the longitudinal direction of said spacing means (92, 94, 96); and adhering said first assembly chips (104a, 104b, 104c, 104d) with second assembly chips (110a, 110b, 110c, 110d) processed to have grooves to form a first side leg (116), a second side leg (118) and a common leg (120) having a notch (122) to correspond with said spacing means (92, 94, 96) in such a manner that said notch (122) of said common leg (120) corresponds with said spacing means (92, 94, 96), thereby defining first and second magnetic flux paths, and forming respective windings on said first and second side legs (116, 118).

Claim 11

A process for manufacturing a composite magnetic head structure comprising the steps of: forming in a first magnetic plate (66) and a second magnetic plate (64) a plurality of parallel notches (76a, 76b, 76c, 76d, 76e) at a predetermined pitch and of a predetermined width defining a track width; forming a groove (72, 74) defining a gap depth in said first magnetic plate (66) in a direction perpendicular to said plurality of parallel notches (76a - 76e); adhering said first and second magnetic plates (66, 64) in such a manner that a non-magnetic material layer (78) is interposed therebetween and said plurality of parallel notches (76a - 76e) in said respective magnetic plates (66, 64) oppose each other to form a plurality of parallel holes (77a - 77e); opposing and adhering two assemblies (90 1 , 90 2 ) formed by said adhering step in such a manner that non-magnetic spacing means (92, 94, 96) is interposed therebetween and said plurality of parallel holes (77a - 77e) of said assemblies (90 1 , 90 2 ) are mutually shifted by half the pitch; cutting the obtained adhered assemblies into a plurality of assembly blocks (104) along planes extending perpendicular to said spacing means (92, 94, 96) and perpendicular to the longitudinal direction of said plurality of holes (77a - 77e); cutting the obtained assembly block into a plurality of first assembly chips (104a, 104b, 104c, 104d) along lines (124 1 , 124 2 , 124 3 ) passing the middle points between said holes (77a - 77e) of one assembly (90 1 ) and perpendicular to the longitudinal direction of said spacing means (92, 94, 96); and adhering said first assembly chips (104a, 104b, 104c, 104d) with second assembly chips (110a, 110b, 110c, 110d) processed to have grooves to form a first side leg (116), a second side leg (118) and a common leg (120) having a notch (122) to correspond with said spacing means (92, 94, 96) in such a manner that said notch (122) of said common leg (120) corresponds with said spacing means (92, 94, 96), thereby defining first and second magnetic flux paths, and forming respective windings on said first and second side legs (116, 118).

Claim 12

A process according to claim 9, wherein the last step comprises winding windings on said first and second side legs (116, 118) respectively and adhering said first assembly chips to said second assembly chips.

Claim 13

A process according to claim 9, wherein the last step comprises arranging annular winding coils prepared in advance on said first and second side legs (116, 118) respectively and adhering said first assembly chips to said second assembly chips.

Claim 14

A process according to claim 9, wherein said non-magnetic material layer (78) is formed by vapor deposition of the non-magnetic material.

Claim 15

A process according to claim 9, wherein said non-magnetic material layer (78) is formed by sputtering the non-magnetic material.