Patent US4963425A successfully refreshed from Google Patents.
US4963425A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Printed wiring board substrate for surface mounted components
Assignee: Unisys Corp
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Filing: 1985-03-05
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Granted: 1990-10-16
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Expires: 2005-03-05
Abstract
Abstract A laminated printed wiring board having surfaces thereof fabricated from conventional fiber reinforced laminates which are secured together by means of an adhesive fabricated of a reinforced thermosetting resin having a coefficient of thermal expansion (CTE) which is substantially smaller than the CTE of the surface laminate whereby the apparent CTE of the overall printed wiring board assembly is substantially controlled.
Inventors
- 👤 Alan M. Buchanan
- 👤 Jay S. Abramowitz
- 👤 Roberta A. Y. Flygare
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:18
CPC Classifications
B; B32; B32B; B32B7/00; B32B7/04; B32B7/12; B32B19/00; B32B19/04; B32B19/041; B32B27/00; B32B27/34; H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/0353; H05K1/036; H05K1/0366; H05K3/00; H05K3/46; H05K3/4611; H05K3/4641; B32B2250/00; B32B2250/40; B32B2262/00; B32B2262/02; B32B2262/0261; B32B2262/10; B32B2262/101; B32B2313/00; B32B2313/02; B32B2313/04; B32B2377/00; B32B2398/00; B32B2398/10; B32B2457/00; B32B2457/08; H05K1/05; H05K1/056; H05K1/09; H05K1/092; H05K1/095; H05K2201/00; H05K2201/02; H05K2201/0275; H05K2201/0278; H05K2201/03; H05K2201/032; H05K2201/0323; H05K2201/06; H05K2201/068; H05K2201/09; H05K2201/09209; H05K2201/0929; H05K2201/09309; H05K3/4626; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24917; Y10T428/24926; Y10T428/24942; Y10T428/25; Y10T428/256
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
123 words
A composite circuit board structure comprising, first and second printed wiring boards fabricated of a generally electrically non-conductive material adapted to receive and support thereon at least one component having a coefficient of thermal expansion which is less than the coefficient of thermal expansion of said printed wiring boards, and a thermoset adhesive layer disposed between and adhered to each of said first and second printed wiring boards, said adhesive layer having a coefficient of thermal expansion which is less than the coefficient of thermal expansion of said component and capable of restraining the expansion rate of said first and second printed wiring boards whereby the apparent coefficient of thermal expansion of the composite circuit board structure approaches that of each said component.
Claim 2
Dependent Claim
123 words
A composite circuit board structure comprising, first and second printed wiring boards fabricated of a generally electrically non-conductive material adapted to receive and support thereon at least one component having a coefficient of thermal expansion which is less than the coefficient of thermal expansion of said printed wiring boards, and a thermoset adhesive layer disposed between and adhered to each of said first and second printed wiring boards, said adhesive layer having a coefficient of thermal expansion which is less than the coefficient of thermal expansion of said component and capable of restraining the expansion rate of said first and second printed wiring boards whereby the apparent coefficient of thermal expansion of the composite circuit board structure approaches that of each said component.
Claim 3
Dependent Claim
23 words
The structure recited in claim 1 wherein, said adhesive layer is impregnated with conductive material wherein said adhesive exhibits thermal and electrical conductivity.
Claim 4
Dependent Claim
37 words
The structure recited in claim 1 wherein, said adhesive layer is impregnated with conductive material wherein said adhesive layer exhibits thermal and electrical conductivity continuous with at least portions of said first and second printed wiring boards.
Claim 5
Dependent Claim
17 words
The structure recited in claim 1 including, a layer of conductive material disposed intermediate said adhesive layer.
Claim 6
Dependent Claim
18 words
The structure recited in claim 1 including, a layer of non-conductive material disposed intermediate to said adhesive layer.
Claim 7
Dependent Claim
14 words
The structure recited in claim 1 wherein, said adhesive layer comprises a non-conductive material.
Claim 8
Dependent Claim
29 words
The structure recited in claim 3 wherein, at least one of said first and second printed wiring boards includes a conductive layer which is contiguous with said adhesive layer.
Claim 9
Dependent Claim
22 words
The structure recited in claim 6 wherein, said non-conductive material comprises an aramid, fused silica, quartz, or similar fiber reinforced thermosetting resin.
Claim 10
Dependent Claim
16 words
The structure recited in claim 3 wherein, said conductive material comprises graphite, boron or the like.
Claim 11
Dependent Claim
18 words
The structure recited in claim 1 wherein, said wiring boards are fabricated of a glass-fiber reinforced, thermosetting resin.
Claim 12
Dependent Claim
15 words
The structure recited in claim 1 wherein, said wiring boards comprise multilayer printed circuit boards.
Claim 13
Dependent Claim
19 words
The structure recited in claim 1 wherein, said boards are fully cured when said adhesive layer is disposed therebetween.
Claim 14
Dependent Claim
37 words
The structure recited in claim 1 wherein, said wiring boards have a coefficient of thermal expansion of greater than 2.0 microinch/inch°F., and said adhesive layer has a cured coefficient of thermal expansion of less than 2.0 microinch/inch°F.
Claim 15
Dependent Claim
25 words
The structure recited in claim 5 wherein, said layer of non conductive material has a cured coefficient of thermal expansion of greater than 2.0 microinch/inch°F.
Claim 16
Dependent Claim
34 words
The structure recited in claim 1 including, printed wiring conductors disposed on the outer surface of at least one of said first and second printed wiring boards and adapted for connection to said component.
Claim 17
Dependent Claim
14 words
The structure recited in claim 1 wherein, said component is a ceramic chip carrier.
Claim 18
Dependent Claim
23 words
The structure recited in claim 16 wherein, said ceramic chip carrier and said composite structure have substantially the same coefficient of thermal expansion.
Claim 19
Dependent Claim
21 words
The structure recited in claim 2 wherein, said adhesive layer forms a thermally conductive layer which operates as a heat sink.
Claim 20
Dependent Claim
19 words
The structure recited in claim 2 wherein, said adhesive layer produces a ground plane for said printed wiring boards.
Claim 21
Dependent Claim
18 words
The structure recited in claim 6 wherein, said adhesive layer produces a power plane for the composite structure.
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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) | 1993-10-15 | 1994-04-16 | 1994-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-15 | 1998-04-16 | 1998-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-15 | 2002-04-16 | 2002-10-16 | $7700.00 | Window Closed / Lapsed |