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US 7,460,342 B2Granted
Method to form tapered magnetic shield for perpendicular recording head
AssigneeHeadway Technologies, Inc.
InventorsLijie Guan, Yaw-Shing Tang, Ellis Cha
Life of this patent
Estimating the term…
Abstract
The inadvertent introduction of stray fields at the media surface by the shields that form part of a magnetic read-write head has been eliminated by using a combination of masking and ion milling to remove small amounts of material close to the shields' outer edges. As a consequence, instead of presenting a sharp edge to the ABS, a shield's lower surface slopes gently away from it.
Claims29
A process to modify a magnetic shield in order to reduce sensitivity to external magnetic fields of a magnetic read-write head, comprising:
- providing an assembly that includes a magnetic read head, centrally disposed between first and second magnetic shields, and a perpendicular magnetic write head disposed between a third magnetic shield and said second magnetic shield;
- polishing said assembly so that said read and write heads and all three said shields have coplanar lower surfaces that constitute an ABS;
- forming, on said ABS, a mask, having vertical edges, that covers said read and write heads as well as said magnetic shields except for opposing unprotected areas that extend inwards a first distance from said shields' vertical edges;
- by means of ion beam milling, removing material from said unprotected areas whereby said third shield acquires a first, centrally located, lower surface, that is coplanar with the ABS, two opposing second lower surfaces that are parallel to, and located a second distance above, the ABS, and opposing sloping surfaces that connect said first and second lower surfaces;
- and
- then removing said mask.
3 more elements
A process to modify a magnetic shield in order to reduce sensitivity to external magnetic fields of a magnetic read-write head, comprising:
- providing an assembly that includes a magnetic read head, centrally disposed between first and second magnetic shields, and a perpendicular magnetic write head disposed between a third magnetic shield and said second magnetic shield;
- polishing said assembly so that said read and write heads and all three said shields have coplanar lower surfaces that constitute an ABS;
- forming, on said ABS, a mask, having vertical and horizontal edges, that covers said read and write heads as well as said magnetic shields except for opposing unprotected areas that extend inwards a first distance from said shields' vertical edges and a single unprotected area that extends inwards a second distance from said third shield's outer horizontal edge;
- by means of ion beam milling, removing material from said unprotected areas whereby said third shield acquires a first, centrally located, lower surface that is coplanar with the ABS, a second lower surface located a third distance above the ABS and surrounding said first lower surface on three sides, opposing sloping surfaces that connect said first and second lower surfaces along a horizontal direction, and a single sloping surface that connects said first and second lower surfaces along a vertical direction;
- and
- then removing said mask.
3 more elements
A magnetic shield having reduced sensitivity to external magnetic fields, comprising:
- an assembly that includes a magnetic read head, centrally disposed between First and second magnetic shields, and a perpendicular magnetic write head disposed between a third magnetic shield and said second magnetic shield;
- said assembly being constructed so that said read and write heads and all three said shields have coplanar lower surfaces that constitute an ABS;
- and
- said third shield having a first, centrally located, lower surface that is coplanar with the ABS, two opposing second lower surfaces that are parallel to, and located a second distance above, the ABS, and opposing sloping surfaces that connect said first and second lower surfaces.
1 more element
A modified magnetic shield having reduced sensitivity to external magnetic fields, comprising:
- an assembly that includes a magnetic read head, centrally disposed between first and second magnetic shields, and a perpendicular magnetic write head disposed between a third magnetic shield and said second magnetic shield;
- polishing said assembly so that said read and write heads and all three said shields have coplanar lower surfaces that constitute an ABS;
- forming, on said ABS, a mask, having vertical and horizontal edges, that covers said read and write heads as well as said magnetic shields except for opposing unprotected areas that extend inwards a first distance from said shields' vertical edges and a single unprotected area that extends inwards a second distance from said third shield's outer horizontal edge;
- by means of ion beam milling, removing material from said unprotected areas whereby said third shield acquires a first, centrally located, lower surface that is coplanar with the ABS, a second lower surface, located a third distance above the ABS and surrounding said first lower surface on three sides, opposing sloping surfaces that connect said first and second lower surfaces along a horizontal direction, and a single sloping surface that connects said first and second lower surfaces along a vertical direction;
- and
- then removing said mask.
3 more elements
Dependencies are inferred from the claim text.