Patent EP0194381A2 successfully refreshed from Google Patents.
EP0194381A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Dielectric materials having low dielectric constants and methods for their manufacture
Assignee: W.L. Gore and Associates Inc
•
Filing: 1985-12-12
•
Granted: —
•
Expires: 2005-12-12
Abstract
Abstract Dielectric materials having low dielectric constant are provided, the materials comprising fabrics impregnated with theremosetting resins, at least a portion of the fibers in the fabrics being fluorocarbon fibers. Also provided is a method of manufacture of these dielectric materials. The dielectric materials are useful in the fabrication of multilayer printed circuit boards.
Inventors
- 👤 Daniel D. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 16:41
CPC Classifications
B; B32; B32B; B32B5/00; B32B5/02; H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; B32B5/22; B32B5/24; B32B5/28; B32B15/00; B32B15/14; B32B15/20; B32B27/00; B32B27/12; B32B27/28; B32B27/281; B32B27/34; B32B27/38; B32B38/00; B32B38/08; B32B5/022; B32B5/024; B32B5/26; B32B7/00; B32B7/04; B32B7/12; C; C08; C08J; C08J5/00; C08J5/04; H05K1/0313; H05K1/0353; H05K1/036; H05K1/0366; B32B2260/00; B32B2260/02; B32B2260/021; B32B2260/023; B32B2260/04; B32B2260/046; B32B2262/00; B32B2262/02; B32B2262/0261; B32B2262/10; B32B2262/101; B32B2307/00; B32B2307/20; B32B2307/204; B32B2315/00; B32B2315/08; B32B2315/085; B32B2363/00; B32B2377/00; B32B2379/00; B32B2379/08; H05K2201/00; H05K2201/01; H05K2201/0137; H05K2201/015; H05K2201/02; H05K2201/0275; H05K2201/0278; H05K2201/03; H05K2201/032; H05K2201/0323; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31511; Y10T428/31529; Y10T428/3154; Y10T428/31544; Y10T428/31678; Y10T428/31721; Y10T442/00; Y10T442/30; Y10T442/3382; Y10T442/3415; Y10T442/3423
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
61 words
A dielectric material comprising a fabric having fibers and interstices between said fibers, in which at least a portion of the fibers in said fabric are fluorocarbon fibers, the fabric being impregnated within said interstices between said fibers with a thermosetting resin cured to at least the semi-cured, B-stage state, the dielectric constant of said dielectric material being less than 3.5.
Claim 2
Dependent Claim
61 words
A dielectric material comprising a fabric having fibers and interstices between said fibers, in which at least a portion of the fibers in said fabric are fluorocarbon fibers, the fabric being impregnated within said interstices between said fibers with a thermosetting resin cured to at least the semi-cured, B-stage state, the dielectric constant of said dielectric material being less than 3.5.
Claim 3
Dependent Claim
18 words
A dielectric material according to claim 1 characterised in that it has a dielectric constant less than 3.0.
Claim 4
Dependent Claim
23 words
A dielectric material according to claim 1 or claim 2 characterised in that the thermosetting resin is cured to the fully-cured, C-stage state.
Claim 5
Dependent Claim
23 words
A dielectric material according to claim 3 characterised by an electrically conductive foil bonded to at least one surface of the impregnated fabric.
Claim 6
Dependent Claim
30 words
A dielectric material according to claim 3 or claim 4 characterised in that the impregnated fabric is in sheet form having an electrically conductive foil bonded to one side thereof.
Claim 7
Dependent Claim
22 words
A dielectric material according to claim 5 characterised in that the impregnated fabric has electrically conductive foil bonded to both sides thereof.
Claim 8
Dependent Claim
20 words
A dielectric material according to any one of claims 4 to 6 characterised in that said foil is copper foil.
Claim 9
Dependent Claim
46 words
A dielectric material according to claim 3 in the form of a laminated composite structure characterised by it comprising two or more sheets of the impregnated fabric and having an electrically conductive foil bonded to at least one side of at least one of said sheets.
Claim 10
Dependent Claim
81 words
A dielectric material according to claim 1 in the form of a laminated composite structure characterised by one or more sheets of the impregnated fabric in which the thermosetting resin is cured to the fully-cured, C-stage state, and one or more sheets of the impregnated fabric in which the thermosetting resin is cured to the semi-cured, B-stage state, wherein, wherever a layer of material in said C-stage state contacts another layer, said other layer is of material in said B-stage state.
Claim 11
Dependent Claim
110 words
10: A dielectric material according to claim 1 in the form of a laminated composite structure characterised by one or more sheets of the impregnated fabric in which the thermosetting resin is cured to the fully-cured, C-stage state, and having an electrically conductive foil bonded to at least one side of at least one of said sheets, and one or more sheets of the impregnated fabric in which the thermosetting resin is cured to the semi-cured, B-stage state, wherein, wherever a layer of material in said C-stage state contacts another layer, and wherever an electrically conductive foil contacts another layer, said other layer is of material in said B-stage state.
Claim 12
Dependent Claim
35 words
A composite structure according to any one of claims 8 to 10 characterised by at least one additional layer which is a layer of epoxy/fiberglass, fluorocarbon/fiberglass, polyimide/fiberglass, epoxy/polyaramide fiber, epoxy/quartz fiber or polyimide/quartz fiber composites.
Claim 13
Dependent Claim
25 words
A dielectric material according to any preceding claim characterised in that said thermosetting resin is an epoxy, polyimide, polyamide, polyester, phenolic or acrylic thermosetting resin.
Claim 14
Dependent Claim
30 words
A dielectric material according to any preceding claim characterised in that all said fibers in said fabric other than fluorocarbon fibers are fiberglass fibers or polyaramide fibers or quartz fibers.
Claim 15
Dependent Claim
23 words
A dielectric material according to any preceding claim characterised in that said fabric is a woven fabric or a non-woven felt or mat.
Claim 16
Dependent Claim
40 words
A dielectric material according to any preceding claim characterised in that said fluorocarbon fibers are drawn, non-porous, sintered PTFE fibers, or expanded, porous PTFE fibers, and said fluorocarbon fibers contain a dielectric insulator material or other material as a filler.
Claim 17
Dependent Claim
28 words
A dielectric material according to claim 15 characterised in that said filler is electrically conductive or semi-conductive, and is a metal, a metal oxide, carbon, ceramic or glass.
Claim 18
Dependent Claim
85 words
A process for making the dielectric material of claim 1 characterised by: (a) treating fluorocarbon fibers to render them wettable by an uncured thermosetting resin, the fibers being held under longitudinal tension during such treatment, thereby preventing longitudinal shrinkage of said fibers during treatment, (b) weaving said fabric containing at least a portion of said treated fluorocarbon fibers, (c) impregnating said fabric with an uncured thermosetting resin, and (d) heating and drying said resin-impregnated-fabric to cure said resin to at least the semi-cured, B-stage state.
Claim 19
Dependent Claim
62 words
A process for making the dielectric material of claim 1, characterised by: (a) treating a fabric containing at least a portion of fluorocarbon fibers to render said fluorocarbon fibers wettable by an uncured thermosetting resin, (b) impregnating said fabric with an uncured thermosetting resin, and (c) heating and drying said resin-impregnated-fabric to cure said resin to at least the semi-cured, B-stage state.
Claim 20
Dependent Claim
21 words
A process according to claim 17 or claim 18 characterised by the step of calendering said fabric to reduce its thickness.
Claim 21
Dependent Claim
26 words
A process according to claim 17 or claim 18 characterised in that said treating includes applying an alkali naphthanate solution to said fluorocarbon fibers or fabric.
Claim 22
Dependent Claim
22 words
A process according to claim 20 characterised by napping the fluorocarbon fibers to improve wettability and adhesion between said fibers and resin.
Claim 23
Dependent Claim
26 words
A process according to claim 17 or claim 18 characterised in that said fibers or fabric are bleached subsequent to treating them to make them wettable.
Claim 24
Dependent Claim
20 words
A process according to claim 22 characterised by the use of an oxidizing agent to bleach the fibers or fabric.
Claim 25
Dependent Claim
36 words
A process according to claim 23 characterised in that the fibers or fabric are bleached by heating to a temperature in the range of about 500°F. to about 6 75 0 F (260°c to 357 °C).
Claim 26
Dependent Claim
35 words
A process according to claim 18 characterised in that said fabric is held in longitudinal and transverse tension during said treatment, thereby preventing shrinkage of said fabric in the longitudinal and transverse directions during treatment.
Claim 27
Dependent Claim
36 words
A process according to claim 18 cgaracterised in that said fabric is unrestrained during said treatment and is allowed to shrink, following which the fabric is stretched to approximately its original dimensions prior to said treatment.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.