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US5282308A
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Thin film planarization process for fabricating magnetic heads employing a stitched pole structure
Assignee: HGST Netherlands BV
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Filing: 1992-12-29
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Granted: 1994-02-01
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Expires: 2012-12-29
Abstract
Abstract A method for fabricating a thin film magnetic head assembly including the procedure of hardening a portion of the upper pole-tip photoresist mask to create a planarizing stitching pedestal in the region where the upper pole-tip overlaps with the upper pole-yoke. The upper pole assembly is deposited in two steps to create a stitched pole consisting of an upper pole-tip joined to an upper pole-yoke element at the stitching pedestal. The method reduces process complexity by eliminating masking steps and also eliminates the usual close alignment requirements for upper insulation and pole-yoke deposition procedures, thereby improving process yield.
Inventors
- 👤 Mao-Min Chen
- 👤 Kochan Ju
- 👤 Rodney E. Lee
- 👤 Ching Tsang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:25
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3109; G11B5/3116; G11B5/3163; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49048; Y10T29/49052
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
222 words
A method for fabricating a thin film magnetic head, said method comprising the steps of: (a) depositing a first layer of ferromagnetic pole material on a substrate to form a lower pole having a front pole-tip region and a back pole-yoke region, said front and back regions overlapping in a yoke-tip junction area; (b) depositing a second layer of nonmagnetic insulating material over said first layer; (c) depositing a third layer of photoresist material over said second layer; (d) defining an upper pole-tip area by selectively removing portions of said third layer from said front pole-tip region; (e) depositing a fourth layer of ferromagnetic pole material on said second layer in said upper pole-tip area to form an upper pole-tip; (f) hardening said photoresist material in said yoke-tip junction area of said third layer to form an upper pole stitching pedestal; (g) depositing at least one fifth layer of conductive coil material to form one or more coils over said back pole-yoke region of said second layer; (h) depositing at least one sixth layer of nonmagnetic insulating material over said fifth layer; and (i) depositing a seventh layer of ferromagnetic pole material over said back pole-yoke region of said sixth layer to form an upper pole-yoke such that said upper pole-yoke joins with said upper pole-tip at said upper pole stitching pedestal.
Claim 2
Independent Claim
222 words
A method for fabricating a thin film magnetic head, said method comprising the steps of: (a) depositing a first layer of ferromagnetic pole material on a substrate to form a lower pole having a front pole-tip region and a back pole-yoke region, said front and back regions overlapping in a yoke-tip junction area; (b) depositing a second layer of nonmagnetic insulating material over said first layer; (c) depositing a third layer of photoresist material over said second layer; (d) defining an upper pole-tip area by selectively removing portions of said third layer from said front pole-tip region; (e) depositing a fourth layer of ferromagnetic pole material on said second layer in said upper pole-tip area to form an upper pole-tip; (f) hardening said photoresist material in said yoke-tip junction area of said third layer to form an upper pole stitching pedestal; (g) depositing at least one fifth layer of conductive coil material to form one or more coils over said back pole-yoke region of said second layer; (h) depositing at least one sixth layer of nonmagnetic insulating material over said fifth layer; and (i) depositing a seventh layer of ferromagnetic pole material over said back pole-yoke region of said sixth layer to form an upper pole-yoke such that said upper pole-yoke joins with said upper pole-tip at said upper pole stitching pedestal.
Claim 3
Dependent Claim
47 words
The method of claim 1 wherein said second depositing step (b) comprises the steps of: (b.1) depositing a gap-forming layer of nonmagnetic insulating material over said first layer; and (b.2) depositing an insulating layer of nonmagnetic insulating material over said back pole-yoke region of said gap-forming layer.
Claim 4
Dependent Claim
86 words
The method of claim 2 wherein said seventh depositing step (i) comprises the steps of: (i.1) forming an opening in said back pole-yoke region to expose a portion of said lower pole; and (i.2) depositing a seventh layer of ferromagnetic pole material over said back pole-yoke region of said sixth layer to form an upper pole-yoke such that said upper pole-yoke joins with said upper pole-tip at said upper pole stitching pedestal and such that said upper pole-yoke joins with said lower pole at said opening.
Claim 5
Dependent Claim
14 words
The method of claim 3 wherein said first, fourth and seventh layers include permalloy.
Claim 6
Dependent Claim
25 words
The method of claim 4 wherein said second and sixth layers include at least one material selected from a group consisting of silica and alumina.
Claim 7
Dependent Claim
86 words
The method of claim 1 wherein said seventh depositing step (i) comprises the steps of: (i.1) forming an opening in said back pole-yoke region to expose a portion of said lower pole; and (i.2) depositing a seventh layer of ferromagnetic pole material over said back pole-yoke region of said sixth layer to form an upper pole-yoke such that said upper pole-yoke joins with said upper pole-tip at said upper pole stitching pedestal and such that said upper pole-yoke joins with said lower pole at said opening.
Claim 8
Dependent Claim
14 words
The method of claim 1 wherein said first, fourth and seventh layers include permalloy.
Claim 9
Dependent Claim
25 words
The method of claim 1 wherein said second and sixth layers include at least one material selected from a group consisting of silica and alumina.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-01-31 | 1997-08-02 | 1998-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-01-31 | 2001-08-02 | 2002-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-01-31 | 2005-08-02 | 2006-02-01 | $7700.00 | Window Closed / Lapsed |