US4871595A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lyotropic liquid crystalline oriented polymer substrate for printed wire board
Assignee: Vencore Services and Solutions Inc
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Filing: 1986-12-16
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Granted: 1989-10-03
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Expires: 2006-12-16
Abstract
Abstract The present invention is directed to the use of ordered polymers as a substrate material for the preparation of printed wire boards (PWB). In preferred embodiments, the PWB of the present invention comprises a generic, high density, organic multilayer PWB capable of being employed as a high density leadless perimeter and in grid array ceramic chip packages. Specific chip package density requirements are 0.020-in. centers with up to 300 input/outputs (I/Os) for perimeter type packages and 0.050-in. center grid array type packages with up to 240 I/Os per device. In its most preferred embodiments, the present invention is directed to a method of forming a PBT PWB substrate layer of 0.0025 in. or less in thickness. Another preferred aspect of the present invention concerns the discovery that a copper layer can be bonded to a PBT film substrate with a strength comparable to existing PWB materials.
Inventors
- 👤 Richard W. Lusignea
- 👤 William A. Stevenson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:31
CPC Classifications
H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/032; H05K1/0333; H05K3/00; H05K3/38; H05K3/388; H05K2201/00; H05K2201/01; H05K2201/0137; H05K2201/0141; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10S428/91; Y10S525/00; Y10S525/903; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678; Y10T428/31681
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
37 words
A method of forming a multilayer PWB substrate, comprising bonding together several poly-benzobisthiazole film layers, none of which exceeds about 0.0025 inches in thickness, thereby forming a multilayer board having a plurality of laminated poly-benzobisthiazole film layers
Claim 2
Independent Claim
37 words
A method of forming a multilayer PWB substrate, comprising bonding together several poly-benzobisthiazole film layers, none of which exceeds about 0.0025 inches in thickness, thereby forming a multilayer board having a plurality of laminated poly-benzobisthiazole film layers
Claim 3
Dependent Claim
20 words
As an article of manufacture, a printed wire board substrate prepared from a molecularly oriented lyotropic liquid crystalline polymer film.
Claim 4
Dependent Claim
20 words
As an article of manufacture, a printed wire board substrate prepared from a molecularly oriented lyotropic liquid crystalline polymer film.
Claim 5
Dependent Claim
23 words
The printed wire board substrate of claim 1, which further has the following characteristics: (a) is non-electrically conducting; and (b) has low-moisture absorption.
Claim 6
Dependent Claim
15 words
The printed wire board substrate of claim 3, wherein the molecularly oriented polymer is poly-benzobisthiazole.
Claim 7
Dependent Claim
16 words
The printed wire board substrate of claim 4, which further comprises a copper layer bonded thereto.
Claim 8
Dependent Claim
34 words
The printed wire board substrate of claim 4, wherein the poly-benzobisthiazole has the following additional property: tailorable coefficient of thermal expansion (CTE) (X-Y direction) in range of from about 3 to 7×10 -6 in./in./°C.
Claim 9
Dependent Claim
25 words
The printed wire board substrate of claim 5, wherein the poly-benzobisthiazole has the following additional property: CTE of thickness (Z direction) approaching that of copper.
Claim 10
Dependent Claim
26 words
The printed wire board substrate of claim 4, wherein the poly-benzobisthiazole has the following additional property: low-moisture absorption, i.e., not exceeding about 0.5 percent at saturation.
Claim 11
Dependent Claim
23 words
The printed wire board substrate of claim 4, which further comprises a plurality of ordered polymer layers, making up a multilayer laminated board.
Claim 12
Dependent Claim
16 words
The printed wire board substrate of claim 9, which further comprises a copper layer bonded thereto.
Claim 13
Dependent Claim
27 words
The printed wire board substrate of claim 9, wherein the poly-benzobisthiazole has the following additional property: maximum thickness of a single layer not exceeding about 0.0025 in.
Claim 14
Dependent Claim
27 words
The printed wire board substrate of claim 9, wherein the poly-benzobisthiazole has the following additional property: interlaminar shear strength greater than glass/Kerimid 601 or equal to glass/epoxy.
Claim 15
Dependent Claim
21 words
The printed wire board substrate of claim 9, wherein the poly-benzobisthiazole has the following additional property: flexural strength equivalent to glass/polymide.
Claim 16
Dependent Claim
33 words
The printed wire board substrate of claim 9, wherein the poly-benzobisthiazole has the following additional property: dielectric constant not exceeding about 3.5 over the functional frequency range of 1 kHz to 500 MHz.
Claim 17
Dependent Claim
27 words
The printed wire board substrate of claim 9, which is capable of being employed as a high density leadless perimeter and in grid array ceramic chip packages.
Claim 18
Dependent Claim
41 words
The printed wire board substrate of claim 15, wherein the chip package density requirements include 0.020-in. centers with up to 300 input/outputs (I/Os) for perimeter type packages and 0.050-in. center grid array type packages with up to 240 I/Os per device.
Claim 19
Dependent Claim
19 words
The copper coated PWB substrate of claim 5, wherein the copper has been deposited by means of plasma coating.
Claim 20
Dependent Claim
19 words
The copper coated PWB substrate of claim 5, wherein the copper has been deposited by means of ion plating.
Claim 21
Dependent Claim
19 words
The copper coated PWB substrate of claim 10, wherein the copper has been deposited by means of plasma coating.
Claim 22
Dependent Claim
19 words
The copper coated PWB substrate of claim 10, wherein the copper has been deposited by means of ion plating.
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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) | 1992-10-02 | 1993-04-03 | 1993-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-02 | 1997-04-03 | 1997-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-02 | 2001-04-03 | 2001-10-03 | $7700.00 | Window Closed / Lapsed |