US4075420A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cover layer for flexible circuits
Assignee: Unisys Corp
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Filing: 1975-08-28
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Granted: 1978-02-21
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Expires: 1995-08-28
Abstract
Abstract A cover layer for flexible circuits which provides increased flexibility. The cover layer encapsulates a flexible circuit having a plurality of spaced conductors on a flexible insulating substrate. The cover layer is a tri-layered laminate having a first layer of insulating film, a second intermediate layer of a thermosetting adhesive, and a third layer of a phenolic resin adhesive. The cover layer is bonded to the flexible circuit with the third layer of phenolic resin adhesive being contiguous the conductors.
Inventors
- 👤 Tommy L. Walton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:39
CPC Classifications
H; H01; H01B; H01B7/00; H01B7/08; H01B7/0838; H05; H05K; H05K3/00; H05K3/22; H05K3/28; H05K3/281; H05K3/38; H05K3/386; H01B11/00; H01B11/02; H01B11/06; H01B11/10; H01B11/1008; H05K1/00; H05K1/02; H05K1/03; H05K1/0393; H05K2201/00; H05K2201/01; H05K2201/0137; H05K2201/0154; H05K2201/0183; H05K2201/0195; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511; Y10T428/31515; Y10T428/31678; Y10T428/31688; Y10T428/31721; Y10T428/31786; Y10T428/31942
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
86 words
A cover layer for a flexible circuit having a plurality of spaced conductors on a flexible substrate, said cover layer comprising: an outer layer of an insulating polyimide film; an intermediate layer of a thermosetting adhesive bonded to said outer layer; and an inner layer of a phenolic resin adhesive bonded to said intermediate layer, wherein said cover layer can be subsequently bonded to the flexible substrate with said inner layer being contiguous with said conductors to provide increased flexibility and protection for the flexible circuit.
Claim 2
Dependent Claim
86 words
A cover layer for a flexible circuit having a plurality of spaced conductors on a flexible substrate, said cover layer comprising: an outer layer of an insulating polyimide film; an intermediate layer of a thermosetting adhesive bonded to said outer layer; and an inner layer of a phenolic resin adhesive bonded to said intermediate layer, wherein said cover layer can be subsequently bonded to the flexible substrate with said inner layer being contiguous with said conductors to provide increased flexibility and protection for the flexible circuit.
Claim 3
Dependent Claim
16 words
The cover layer of claim 1 wherein the phenolic resin adhesive is a phenolic butyrate adhesive.
Claim 4
Dependent Claim
63 words
An encapsulated flexible circuit comprising: a flexible substrate; a plurality of spaced conductors bonded to said substrate; and a tri-layered cover layer bonded to said flexible substrate and covering said conductors, said cover layer having a first outer layer of an insulating film, a second intermediate layer of a thermosetting adhesive, and a third layer of a phenolic resin adhesive contiguous said conductors.
Claim 5
Dependent Claim
63 words
An encapsulated flexible circuit comprising: a flexible substrate; a plurality of spaced conductors bonded to said substrate; and a tri-layered cover layer bonded to said flexible substrate and covering said conductors, said cover layer having a first outer layer of an insulating film, a second intermediate layer of a thermosetting adhesive, and a third layer of a phenolic resin adhesive contiguous said conductors.
Claim 6
Dependent Claim
16 words
The flexible circuit of claim 3 wherein the flexible substrate and insulating film are polyimide films.
Claim 7
Dependent Claim
15 words
The flexible circuit of claim 3 wherein the thermosetting adhesive is a modified epoxy adhesive.
Claim 8
Dependent Claim
16 words
The flexible circuit of claim 3 wherein the phenolic resin adhesive is a phenolic butyrate adhesive.
Claim 9
Dependent Claim
87 words
A cover layer for a flexible circuit having a plurality of spaced conductors on a flexible substrate, said cover layer comprising: an outer layer of an polyimide film; an intermediate layer of a thermosetting modified epoxy adhesive bonded to said outer layer; and an inner layer of a phenolic resin adhesive bonded to said intermediate layer, wherein said cover layer can be subsequently bonded to the flexible substrate with said inner layer being contiguous with said conductors to provide increased flexibility and protection for the flexible circuit.
Claim 10
Dependent Claim
87 words
A cover layer for a flexible circuit having a plurality of spaced conductors on a flexible substrate, said cover layer comprising: an outer layer of an polyimide film; an intermediate layer of a thermosetting modified epoxy adhesive bonded to said outer layer; and an inner layer of a phenolic resin adhesive bonded to said intermediate layer, wherein said cover layer can be subsequently bonded to the flexible substrate with said inner layer being contiguous with said conductors to provide increased flexibility and protection for the flexible circuit.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-20 | 1981-08-22 | 1982-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-20 | 1985-08-22 | 1986-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-20 | 1989-08-22 | 1990-02-21 | $7700.00 | Window Closed / Lapsed |