US4344153A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic bubble memory device and method of fabricating the same
Assignee: Hitachi Ltd
•
Filing: 1979-04-13
•
Granted: 1982-08-10
•
Expires: 1999-04-13
Abstract
Abstract A magnetic bubble memory device and a method of fabricating the device are disclosed in which a conductor pattern lies at least between a film for maintaining magnetic bubbles therein, and a soft magnetic material pattern. Further, the magnetic bubble memory device can be formed precisely without suffering from errors due to mask alignment, by employing a mask provided with a plurality of patterns which are different in transmittance.
Inventors
- 👤 Hideki Nishida
- 👤 Hirozi Yamada
- 👤 Hiroshi Umezaki
- 👤 Yutaka Sugita
- 👤 Norikazu Tsumita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:13
CPC Classifications
H; H01; H01F; H01F10/00; H01F10/06; G; G11; G11C; G11C19/00; G11C19/02; G11C19/08; G11C19/0808; H01F41/00; H01F41/32; H01F41/34
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
77 words
A magnetic bubble memory device comprising a non-magnetic monocrystalline substrate, a magnetic film capable of maintaining magnetic bubbles therein, a conductor pattern for bubble control, a dummy conductor pattern, and soft magnetic material patterns, wherein said conductor patterns lie at least between said magnetic film and said soft magnetic material and wherein the entirety of said soft magnetic material patterns overlie at least portions of said conductor patterns so as to be maintained in one plane thereby.
Claim 2
Dependent Claim
77 words
A magnetic bubble memory device comprising a non-magnetic monocrystalline substrate, a magnetic film capable of maintaining magnetic bubbles therein, a conductor pattern for bubble control, a dummy conductor pattern, and soft magnetic material patterns, wherein said conductor patterns lie at least between said magnetic film and said soft magnetic material and wherein the entirety of said soft magnetic material patterns overlie at least portions of said conductor patterns so as to be maintained in one plane thereby.
Claim 3
Dependent Claim
23 words
A magnetic bubble memory device according to claim 1, wherein an insulating film is interposed between said magnetic film and said conductor pattern.
Claim 4
Dependent Claim
27 words
A magnetic bubble memory device according to claim 1 or 2, wherein an insulating film is interposed between said conductor pattern and said soft magnetic material pattern.
Claim 5
Dependent Claim
34 words
A magnetic bubble memory device according to claim 1 or 2, wherein said conductor pattern is made of a material selected from a group consisting of aluminium, aluminium alloys, gold, silver, copper, and molybdenum.
Claim 6
Dependent Claim
21 words
A magnetic bubble memory device according to claim 1 or 2, wherein said soft magnetic material pattern is made of permalloy.
Claim 7
Dependent Claim
28 words
A magnetic bubble memory device according to claim 1 or 2, wherein a surface of said non-magnetic substrate is coated with a magnetic film for suppressing hard bubbles.
Claim 8
Dependent Claim
21 words
A magnetic bubble memory device according to claim 6, wherein said magnetic film for suppressing hard bubbles is made of permalloy.
Claim 9
Dependent Claim
32 words
A magnetic bubble memory device according to claim 3, wherein said conductor pattern is made of a material selected from a group consisting of aluminum, aluminum alloys, gold, silver, copper, and molybdenum.
Claim 10
Dependent Claim
19 words
A magnetic bubble memory device according to claim 3, wherein said soft magnetic material pattern is made of permalloy.
Claim 11
Dependent Claim
26 words
A magnetic bubble memory device according to claim 3, wherein a surface of said non-magnetic substrate is coated with a magnetic film for suppressing hard bubbles.
References Cited (Backward Citations)
US4001793A
Cited
US4172758A
Cited
US4178635A
Cited
US4187553A
Cited
JPS54136141A
Cited
JPS54149529A
Cited
US4305137A
Cited
JPS5545159A
Cited
US4299680A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-08-09 | 1986-02-08 | 1986-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-09 | 1990-02-08 | 1990-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-09 | 1994-02-08 | 1994-08-10 | $7700.00 | Window Closed / Lapsed |