Patent US609422A successfully refreshed from Google Patents.
US5378306A
Expired / Lapsed
US
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Composite for providing a rigid-flexible circuit board construction and method for fabrication thereof
Assignee: International Business Machines Corp
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Filing: 1994-02-07
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Granted: 1995-01-03
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Expires: 2014-02-07
Abstract
Abstract A rigid-flexible circuit board is fabricated by providing a core having a dielectric substrate and conductive layer thereon. A sub-composite comprising a polyimide and rigid dielectric substrate adjacent the conductive layer and in both the rigid and flexible segments of the board is provided. A release layer corresponding to the flexible segment of the board is provided. A rigid bonding layer is provided at rigid segments of the board but not at the flexible segments. A composite is formed by providing a second conductive layer adjacent the rigid bonding layer. The composite is laminated. Portions of the second conductive layer corresponding to the flexible segment and release layer are removed.
Inventors
- 👤 Michael J. Cibulsky
- 👤 Konstantinos I. Papathomas
- 👤 William J. Summa
- 👤 David W. Wang
- 👤 Patrick R. Zippetelli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:40
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/46; H05K3/4688; H05K3/4691; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/0353; H05K1/0366; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0355; H05K2203/00; H05K2203/30; H05K2203/308; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24851; Y10T428/2486; Y10T428/24917; Y10T428/31504; Y10T428/31511; Y10T428/31515; Y10T428/31522; Y10T428/31678; Y10T428/31721
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
177 words
A process for fabricating a rigid-flexible circuit board comprising: (a) providing at least one core which comprises a dielectric substrate and at least one conductive layer located on said dielectric substrate; (b) providing at least one sub-composite which comprises a polyimide and a rigid dielectric substrate adjacent said at least one conductive layer and in both the rigid and flexible segments of said circuit board; (c) providing a release layer adjacent said at least one sub-composite in a location to correspond to the desired flexible segment of said circuit board; (d) providing at least one rigid bonding layer located adjacent said at least one sub-composite and at the rigid segments of said board but not at the flexible segments of said board; (e) providing a second conductive layer adjacent said at least one rigid bonding layer to thereby form a composite; (f) laminating said composite; (g) removing portions of said second conductive layer that correspond to the flexible segment of said circuit board; and, (h) then removing said release layer to thereby provide said rigid-flexible circuit board.
Claim 2
Dependent Claim
177 words
A process for fabricating a rigid-flexible circuit board comprising: (a) providing at least one core which comprises a dielectric substrate and at least one conductive layer located on said dielectric substrate; (b) providing at least one sub-composite which comprises a polyimide and a rigid dielectric substrate adjacent said at least one conductive layer and in both the rigid and flexible segments of said circuit board; (c) providing a release layer adjacent said at least one sub-composite in a location to correspond to the desired flexible segment of said circuit board; (d) providing at least one rigid bonding layer located adjacent said at least one sub-composite and at the rigid segments of said board but not at the flexible segments of said board; (e) providing a second conductive layer adjacent said at least one rigid bonding layer to thereby form a composite; (f) laminating said composite; (g) removing portions of said second conductive layer that correspond to the flexible segment of said circuit board; and, (h) then removing said release layer to thereby provide said rigid-flexible circuit board.
Claim 3
Dependent Claim
17 words
The process of claim 1 wherein said dielectric substrate is a reinforced epoxy composition or polyimide film.
Claim 4
Dependent Claim
13 words
The process of claim 1 wherein said dielectric substrate is a flexible substrate.
Claim 5
Dependent Claim
42 words
The process of claim 3 wherein said flexible substrate comprises a combination of at least one layer of a polyimide film and at least one layer of an epoxy composition and wherein said epoxy composition contacts said at lest one conductive layer.
Claim 6
Dependent Claim
15 words
The process of claim 4 wherein said polyimide is obtained from biphenyltetracarboxylic dianhydride and diamine.
Claim 7
Dependent Claim
16 words
The process of claim 2 wherein said polyimide is obtained from biphenyltetracarboxylic dianhydride and a diamine.
Claim 8
Dependent Claim
40 words
The process of claim 1 wherein the polyimide of said subprocess is obtained from biphenyltetracarboxylic dianhydride and diamine; the rigid dielectric substrate of said subprocess is an epoxy composition wherein said epoxy composition contacts said conductive layer of said core.
Claim 9
Dependent Claim
18 words
The process of claim 1 wherein said release layer comprises a metal substrate coated with a fluorinated polymer.
Claim 10
Dependent Claim
11 words
The process of claim 8 wherein said metal substrate is copper.
Claim 11
Dependent Claim
14 words
The process of claim 1 wherein said rigid bonding layers are reinforced epoxy compositions.
Claim 12
Dependent Claim
23 words
The process of claim 10 wherein the thickness of said rigid bonding layers is substantially equal to the thickness of said release layer.
Claim 13
Dependent Claim
12 words
The process of claim 1 wherein said second conductive layer is copper.
Claim 14
Dependent Claim
24 words
The process of claim 1 wherein said composite comprises a plurality of at least 3 cores with interim release layers and rigid bonding layers.
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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) | 1998-01-02 | 1998-07-04 | 1999-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-02 | 2002-07-04 | 2003-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-02 | 2006-07-04 | 2007-01-03 | $7700.00 | Window Closed / Lapsed |