Patent US3846841A successfully refreshed from Google Patents.
US3846841A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multiple magnetic head devices
Assignee: CO INT POUR L INF
•
Filing: 1973-06-25
•
Granted: 1974-11-05
•
Expires: 1993-06-25
Abstract
Abstract A plurality of planar magnetic heads have their airgaps aligned along one edge of a common substrate and each coil terminal of the heads substantially reaches the rear edge of said substrate and is equipped with a flat conductor soldered thereto for the electrical connections of the heads to the external circuitry. The invention provides a two-stage protection of the device. The first, or primary, one, consists of a dielectric layer over the planar magnetic head structures, said layer reaching the level of the plane wherein are the exposed surfaces of the flat conductors and coats those parts of the substrate between the head structures. The second, or secondary one, consists of a dielectric plate secured to the top surface of the primary protective layer and the top surfaces of th flat conductors. Both the layer and the plate are of materials which substantially present the same thermal expansion coefficient as the material of the substrate. The secondary protective plate may serve as a substrate for a further group of heads provided with the same two-stage protection, and so forth, or it may be common to two groups of magnetic heads carried by two substrates and each having a primary protective layer, said layers being in facing relation with respect to each other and/or the common secondary protective plate. Magnetic and electrical shield films coat surfaces of the substrate and secondary protective plates.
Inventors
- 👤 J Lazzari
- 👤 J Michard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:57
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; G11B5/31; G11B5/3103; G11B5/3106; G11B5/3109; G11B5/313
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
213 words
A read-write magnetic head device comprising in combination: a. a dielectric, non-magnetic planar substrate; b. a plurality of planar magnetic head structures having their air gaps aligned on one edge of said substrate, each head including a flat coil; c. a plurality of coil terminals substantially aligned on an opposite edge of said substrate; d. a plurality of flat conductors equal in number to said terminals, one soldered to each of said terminals respectively, said conductors having a uniform thickness so that their upper surfaces lie in a common plane parallel to the plane of said substrate; e. a primary protection formed of a dielectric layer coated over said magnetic head structures, having one surface which is flat and substantially level with but spaced from the upper surfaces of said flat conductors and a second surface joining said first and sloping toward but terminating short of said terminals; f. a secondary protection formed of a non-magnetic dielectric plate having substantially the same area as said substrate and applied over the upper surfaces of said primary protection and flat conductors; and g. bonding means between said plaTe and said primary protection and flat conductors; the materials of said primary and secondary protections having coefficient of thermal expansion substantially equal to that of said substrate.
Claim 2
Dependent Claim
213 words
A read-write magnetic head device comprising in combination: a. a dielectric, non-magnetic planar substrate; b. a plurality of planar magnetic head structures having their air gaps aligned on one edge of said substrate, each head including a flat coil; c. a plurality of coil terminals substantially aligned on an opposite edge of said substrate; d. a plurality of flat conductors equal in number to said terminals, one soldered to each of said terminals respectively, said conductors having a uniform thickness so that their upper surfaces lie in a common plane parallel to the plane of said substrate; e. a primary protection formed of a dielectric layer coated over said magnetic head structures, having one surface which is flat and substantially level with but spaced from the upper surfaces of said flat conductors and a second surface joining said first and sloping toward but terminating short of said terminals; f. a secondary protection formed of a non-magnetic dielectric plate having substantially the same area as said substrate and applied over the upper surfaces of said primary protection and flat conductors; and g. bonding means between said plaTe and said primary protection and flat conductors; the materials of said primary and secondary protections having coefficient of thermal expansion substantially equal to that of said substrate.
Claim 3
Dependent Claim
64 words
Combination according to claim 1, wherein said bonding means comprises a mass of resin material bonding the lower surface of the secondary protection plate not applied to the surfaces of said primary protection layer and of said flat conductors to the said sloped surface of the primary protection and the surface of the substrate between the said primary protection layer and said flat conductors.
Claim 4
Dependent Claim
61 words
Combination according to claim 1, wherein the said bonding means comprises the combination of: an insulating film over the upper surfaces of the flat conductors, conductive films coating the upper surface of the primary protection layer and said insulating film, a layer of solder interposed between the said conductive films and the lower surface of the secondary protection plate applied thereover.
Claim 5
Dependent Claim
22 words
Combination according to claim 3, wherein the material of said conductive films constitutes a magnetic and electrical shielding element in the device.
Claim 6
Dependent Claim
37 words
Combination according to claim 1, wherein two groups of heads separately formed on two distinct substrates and each provided with a primary protective layer are assembled with a common secondary plate between the primary protective layers thereof.
Claim 7
Dependent Claim
32 words
Combination according to claim 5, wherein the secondary protective common plate is limited to the flat conductor surface plane and the respective primary protective layers are contacting each other in the assembly.
Claim 8
Dependent Claim
22 words
Combination according to claim 1, wherein the material of said secondary protection plate is the same as the material of the substrate.
Claim 9
Dependent Claim
53 words
Combination according to claim 7, wherein said substrate is a high temperature melting point glass, the material of said primary protection layer consists of an intimate mixture of silicon monoxide and silicon dioxide in a ratio adjusted to impart to the mixture a thermal expansion coefficient substantially equal to that of the glass.
Claim 10
Dependent Claim
20 words
Combination according to claim 7, wherein said substrate is corundum and the material of the primary protection layer is alumina.
Claim 11
Dependent Claim
29 words
Combination according to claim 1 in which there are at least two spaced layers of magnetic heads, said secondary protection plate serving as the substrate for the second layer.
Claim 12
Dependent Claim
18 words
Combination according to claim 10, wherein the substrate and the last secondary protective plate are of identical thickness.
Claim 13
Dependent Claim
21 words
Combination according to claim 10, wherein the substrate and secondary protective plates have surfaces coated with magnetic and electric shield films.
Claim 14
Dependent Claim
32 words
Combination according to claim 10, wherein the magnetic heads in each layer have their airgaps relatively shifted by the widths of said airgap from one to the other one of the layers.
Claim 15
Dependent Claim
25 words
Combination according to claim 10, wherein the geometries of the heads, from group to group of heads, differ according to distinct functions of said heads.
References Cited (Backward Citations)
US3344237A
Cited
US3549825A
Cited
US3564558A
Cited
US3611417A
Cited
US3723665A
Cited
US3700827A
Cited
US3639699A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-04 | 1978-05-06 | 1978-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-04 | 1982-05-06 | 1982-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-04 | 1986-05-06 | 1986-11-05 | $7700.00 | Window Closed / Lapsed |