US5652055A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Matched low dielectric constant, dimensionally stable adhesive sheet
Assignee: W.L. Gore and Associates Inc
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Filing: 1995-04-07
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Granted: 1997-07-29
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Expires: 2015-04-07
Abstract
Abstract The present invention is an improved adhesive sheet (also known as a "bond ply," "bond film," or "prepreg") material suitable for bonding together electric circuit boards and other electrical components. The adhesive sheet of the present invention comprises a combination of a porous expanded polytetrafluoroethylene (PTFE), a ceramic filler, and a thermoset resin imbibed within the porous PTFE structure. By employing a fill of less than about 60% by weight of resin, the adhesive sheet has exceptionally good performance characteristics while being vastly easier to process.
Inventors
- 👤 David R. King
- 👤 Gary C. Adler
- 👤 Joseph E. Korleski
- 👤 Michelle M. H. Waters
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 11:22
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/36; C08J9/40; C08J9/42; C09; C09J; C09J7/00; C09J7/20; C09J7/22; C09J7/26; H; H05; H05K; H05K1/00; H05K1/02; H05K1/03; H05K1/0313; H05K1/0353; H05K3/00; H05K3/46; H05K3/4611; H05K3/4626; C08J2327/00; C08J2327/02; C08J2327/12; C08J2327/18; C08J2461/00; C08L; C08L27/00; C08L27/02; C08L27/12; C08L27/18; H05K1/0213; H05K1/0237; H05K1/024; H05K2201/00; H05K2201/01; H05K2201/0104; H05K2201/0116; H05K2201/0137; H05K2201/015; H05K2201/0183; H05K2201/0195; H05K2201/02; H05K2201/0203; H05K2201/0206; H05K2201/0209; H05K2201/07; H05K2201/0707; H05K2201/0715; H05K2203/00; H05K2203/11; H05K2203/1147; H05K3/38; H05K3/386; Y; Y10; Y10S; Y10S428/00; Y10S428/901; Y10T; Y10T428/00; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826; Y10T428/2848; Y10T428/31504; Y10T428/3154; Y10T428/31544
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
118 words
An adhesive sheet which is dimensionally stable when used through more than one bonding cycle under conditions of heat and pressure that comprises: an expanded polytetrafluoroethylene (PTFE) film containing 9-60 weight percent (based on the weight of the adhesive sheet) ceramic filler, the film including a network of nodes interconnected by fibrils; said film having a B-stage thermosettable resin adhesive imbibed within the film, said thermosettable resin adhesive consisting of no more than 60% by weight of the adhesive sheet; the adhesive sheet having a dielectric constant of less than 4 and being readily processable at temperatures of less than 230° C. at a pressure of less than or equal to 250 lbs/in 2 (170 N/cm 2 ).
Claim 2
Dependent Claim
118 words
An adhesive sheet which is dimensionally stable when used through more than one bonding cycle under conditions of heat and pressure that comprises: an expanded polytetrafluoroethylene (PTFE) film containing 9-60 weight percent (based on the weight of the adhesive sheet) ceramic filler, the film including a network of nodes interconnected by fibrils; said film having a B-stage thermosettable resin adhesive imbibed within the film, said thermosettable resin adhesive consisting of no more than 60% by weight of the adhesive sheet; the adhesive sheet having a dielectric constant of less than 4 and being readily processable at temperatures of less than 230° C. at a pressure of less than or equal to 250 lbs/in 2 (170 N/cm 2 ).
Claim 3
Dependent Claim
20 words
The adhesive sheet of claim 1 wherein the thermosettable resin comprises between 5 and 60% by weight of the sheet.
Claim 4
Dependent Claim
40 words
The adhesive sheet of claim 1 wherein adhesive joins together at least a first layer and a second layer to form a multi-layered substrate; and the adhesive has a dielectric constant similar to that of the first and second layers.
Claim 5
Dependent Claim
19 words
The adhesive sheet of claim 3 wherein the adhesive sheet has a dielectric constant of between 2.5 and 3.4.
Claim 6
Dependent Claim
21 words
The adhesive sheet of claim 1 wherein the multi-layer substrate includes at least one metal layer to form a metal-clad substrate.
Claim 7
Dependent Claim
15 words
The adhesive sheet of claim 5 wherein one of the layers includes a reinforcement layer.
Claim 8
Dependent Claim
42 words
The adhesive sheet of claim 1 wherein adhesive joins together at least a first layer and a second layer to form a multi-layered substrate; and the adhesive has a coefficient of thermal expansion similar to that of the first and second layers.
Claim 9
Independent Claim
179 words
A method for forming a circuit board that comprises: providing an adhesive sheet which is dimensionally stable when used through more than one bonding cycle under conditions of heat and pressure, said adhesive sheet comprising an expanded polytetrafluoroethylene (PTFE) film containing 9-60 weight percent (based on the weight of the adhesive sheet) ceramic filler, the film including a network of nodes interconnected by fibrils and having a B-stage thermosettable resin adhesive imbibed within the film, the thermosettable resin adhesive consisting of no more than 60% by weight of the adhesive sheet, the adhesive sheet having a dielectric constant of less than 4 and being readily processable at temperatures of less than 230° C. at a pressure of less than or equal to 250 pounds/in 2 170 N/cm 2 ; mounting the adhesive sheet between layers of the circuit board; and applying a temperature to the circuit board of less than 230° C. at a pressure of less than or equal to 250 pounds/in 2 to cause the adhesive sheet to adhere to and bond together the circuit board layers.
Claim 10
Independent Claim
179 words
A method for forming a circuit board that comprises: providing an adhesive sheet which is dimensionally stable when used through more than one bonding cycle under conditions of heat and pressure, said adhesive sheet comprising an expanded polytetrafluoroethylene (PTFE) film containing 9-60 weight percent (based on the weight of the adhesive sheet) ceramic filler, the film including a network of nodes interconnected by fibrils and having a B-stage thermosettable resin adhesive imbibed within the film, the thermosettable resin adhesive consisting of no more than 60% by weight of the adhesive sheet, the adhesive sheet having a dielectric constant of less than 4 and being readily processable at temperatures of less than 230° C. at a pressure of less than or equal to 250 pounds/in 2 170 N/cm 2 ; mounting the adhesive sheet between layers of the circuit board; and applying a temperature to the circuit board of less than 230° C. at a pressure of less than or equal to 250 pounds/in 2 to cause the adhesive sheet to adhere to and bond together the circuit board layers.
Claim 11
Dependent Claim
19 words
The method of claim 8 that further comprises providing a metal conductor as at least one of the components.
Claim 12
Dependent Claim
26 words
The method of claim 8 that further comprises providing as the bond film a material with a dielectric constant essentially equal to that of the components.
Claim 13
Dependent Claim
28 words
The method of claim 8 that further comprises providing as the bond film a material with a coefficient of thermal expansion essentially equal to that of the components.
Claim 14
Dependent Claim
16 words
The method of claim 8 that further comprises providing a reinforcement layer in the circuit board.
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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) | 2000-07-28 | 2001-01-27 | 2001-07-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-07-28 | 2005-01-27 | 2005-07-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-07-28 | 2009-01-27 | 2009-07-29 | $7700.00 | Window Closed / Lapsed |