US5288542A
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: 1992-07-14
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Granted: 1994-02-22
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Expires: 2012-07-14
Abstract
Abstract A composite for providing a rigid-flexible circuit board includes at least one core that contains a dielectric substrate and at least one conductive layer thereon; at least one sub-composite that includes a polyimide and a rigid dielectric substrate; a release layer; at least one rigid bonding layer and a second conductive layer. The composite is used in the fabrication of a rigid-flexible circuit board.
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
2026-11-02 11:37
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: 27
Claim 1
Independent Claim
154 words
A composite for providing a rigid-flexible circuit board construction comprising at least one core wherein said at least one core comprises both a dielectric substrate and at least one conductive layer located on said dielectric substrate; at least one sub-composite located on top of said at least one conductive layer and which comprises a polyimide layer and a rigid dielectric substrate, and wherein said rigid dielectric substrate contacts said at least one conductive layer; a release layer located on top of said at least one sub-composite in a predetermined location to correspond to the desired flexible segment of said circuit board; at least one rigid bonding layer located next to each of the two sides of said release layer to correspond to the desired rigid portion of said circuit board; and at least one second conductive layer located on top of said at least one bonding layer and said at least one release layer.
Claim 2
Dependent Claim
154 words
A composite for providing a rigid-flexible circuit board construction comprising at least one core wherein said at least one core comprises both a dielectric substrate and at least one conductive layer located on said dielectric substrate; at least one sub-composite located on top of said at least one conductive layer and which comprises a polyimide layer and a rigid dielectric substrate, and wherein said rigid dielectric substrate contacts said at least one conductive layer; a release layer located on top of said at least one sub-composite in a predetermined location to correspond to the desired flexible segment of said circuit board; at least one rigid bonding layer located next to each of the two sides of said release layer to correspond to the desired rigid portion of said circuit board; and at least one second conductive layer located on top of said at least one bonding layer and said at least one release layer.
Claim 3
Dependent Claim
20 words
The composite of claim 1 wherein said dielectric substrate of the core is a reinforced epoxy composition or polyimide film.
Claim 4
Dependent Claim
16 words
The composite of claim 1 wherein said dielectric substrate of the core is a flexible substrate.
Claim 5
Dependent Claim
42 words
The composite 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 least one conductive layer.
Claim 6
Dependent Claim
16 words
The composite of claim 4 wherein said polyimide is obtained from biphenyltetracarboxylic dianhydride and a diamine.
Claim 7
Dependent Claim
16 words
The composite of claim 2 wherein said polyimide is obtained from biphenyltetracarboxylic dianhydride and a diamine.
Claim 8
Dependent Claim
41 words
The composite of claim 1 wherein the polyimide of said sub-composite is obtained from biphenyltetracarboxylic dianhydride and a diamine; the rigid dielectric substrate of said sub-composite is an epoxy composition wherein said epoxy composition contacts said conductive layer of said core.
Claim 9
Dependent Claim
18 words
The composite of claim 1 wherein said release layer comprises a metal substrate coated with a fluorinated polymer.
Claim 10
Dependent Claim
11 words
The composite of claim 8 wherein said metal substrate is copper.
Claim 11
Dependent Claim
18 words
The composite of claim 1 wherein said at least one rigid bonding layer is a reinforced epoxy composition.
Claim 12
Dependent Claim
26 words
The composite of claim 10 wherein the thickness of said at least one rigid bonding layer is substantially equal to the thickness of said release layer.
Claim 13
Dependent Claim
12 words
The composite of claim 1 wherein said second conductive layer is copper.
Claim 14
Dependent Claim
16 words
The composite of claim 1 wherein all bonding material has a thermal expansion below 300 ppm/°C.
Claim 15
Dependent Claim
133 words
A rigid-flexible circuit board construction comprising: (a) at least one core, wherein said at least one core comprises both a dielectric substrate and at least one conductive layer located on said dielectric substrate; (b) at least one sub-composite located on top of said at least one conductive layer and in both the rigid and flexible segments of said circuit board and which comprises a polyimide layer and a rigid dielectric substrate, and wherein said rigid dielectric substrate contacts said at least one conductive layer; (c) at least one rigid bonding layer located on top of said at least one sub-composite and at the rigid segments of said board but not at the flexible segments of said board; and (d) a second conductive layer on top of said at least one rigid bonding layer.
Claim 16
Dependent Claim
133 words
A rigid-flexible circuit board construction comprising: (a) at least one core, wherein said at least one core comprises both a dielectric substrate and at least one conductive layer located on said dielectric substrate; (b) at least one sub-composite located on top of said at least one conductive layer and in both the rigid and flexible segments of said circuit board and which comprises a polyimide layer and a rigid dielectric substrate, and wherein said rigid dielectric substrate contacts said at least one conductive layer; (c) at least one rigid bonding layer located on top of said at least one sub-composite and at the rigid segments of said board but not at the flexible segments of said board; and (d) a second conductive layer on top of said at least one rigid bonding layer.
Claim 17
Dependent Claim
20 words
The construction of claim 14 wherein said dielectric substrate of the core is a reinforced epoxy composition or polyimide film.
Claim 18
Dependent Claim
16 words
The construction of claim 14 wherein said dielectric substrate of the core is a flexible substrate.
Claim 19
Dependent Claim
42 words
The construction of claim 16 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 least one conductive layer.
Claim 20
Dependent Claim
16 words
The construction of claim 17 wherein said polyimide is obtained from biphenyltetracarboxylic dianhydride and a diamine.
Claim 21
Dependent Claim
41 words
The construction of claim 14 wherein the polyimide of said sub-composite is obtained from biphenyltetracarboxylic dianhydride and a diamine; the rigid dielectric substrate of said sub-composite is an epoxy composition wherein said epoxy composition contacts said conductive layer of said core.
Claim 22
Dependent Claim
18 words
The construction of claim 14 wherein said at least one rigid bonding layer is a reinforced epoxy composition.
Claim 23
Dependent Claim
12 words
The construction of claim 14 wherein said second conductive layer is copper.
Claim 24
Dependent Claim
16 words
The construction of claim 14 wherein all bonding material has a thermal expansion below 300 ppm/°C.
Claim 25
Dependent Claim
16 words
The construction of claim 15 wherein said polyimide is obtained from biphenyltetracarboxylic dianhydride and a diamine.
Claim 26
Dependent Claim
40 words
The composite of claim 1 comprising 3 cores wherein located both above and below the middle one of said 3 cores is a sub-composite, and located above and below the two outer cores is at least one rigid bonding layer.
Claim 27
Dependent Claim
40 words
The construction of claim 14 comprising 3 cores wherein located both above and below the middle one of said 3 cores is a sub-composite, and located above and below the two outer cores is at least one rigid bonding layer.
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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) | 1997-02-21 | 1997-08-23 | 1998-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-21 | 2001-08-23 | 2002-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-21 | 2005-08-23 | 2006-02-22 | $7700.00 | Window Closed / Lapsed |