Adhisive-filler polymer film composite

• US 5,753,358 A
• Filed: 01/25/1996
• Issued: 05/19/1998
• Est. Priority Date: 08/25/1994
• Status: Expired due to Term

• Current Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Original Assignee: W. L. Gore & Associates (W.L. Gore & Associates)
• Inventors: Korleski, Joseph E.
• Primary Examiner(s): Chen, Vivian
• Application Number:
  US08/591,043
• Time in Patent Office: 845 Days
• Field of Search: 428/317.1, 428/317.7, 428/317.9, 428/323, 428/327, 428/328, 428/331, 428/421, 428/422, 428/457, 428/306.6, 428/304.4, 428/308.4, 428/318.4, 428/315.5, 428/315.9, 428/319.3, 428/319.7, 428/319.9, 428/413, 428/463, 428/521
• US Class Current: 428/308.4
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene
• CPC Class Codes: C09J 2203/326 for bonding electronic components such as wafers, chips or semiconductors
• CPC Class Codes: C09J 2400/163 in the substrate
• CPC Class Codes: C09J 2400/263 in the substrate
• CPC Class Codes: C09J 2427/006 in the substrate
• CPC Class Codes: C09J 2463/00 Presence of epoxy resin
• CPC Class Codes: C09J 7/26 Porous or cellular plastics
• CPC Class Codes: C09J 7/29 Laminated material metallised plastics C09J7/22
• CPC Class Codes: H05K 1/0353 consisting of two or more materials, e.g. two or more polymers, polymer + filler, + reinforcement
• CPC Class Codes: H05K 2201/0116 Porous, e.g. foam
• CPC Class Codes: H05K 2201/015 Fluoropolymer, e.g. polytetrafluoroethylene [PTFE]
• CPC Class Codes: H05K 2201/0158 Polyalkene or polyolefin, e.g. polyethylene [PE], polypropylene [PP]
• CPC Class Codes: H05K 2201/0209 Inorganic, non-metallic particles
• CPC Class Codes: H05K 2201/0278 Polymeric fibers
• CPC Class Codes: H05K 2201/0293 Non-woven fibrous reinforcement
• CPC Class Codes: Y10T 428/249953 Composite having voids in a component [e.g., porous, cellular, etc.]
• CPC Class Codes: Y10T 428/249958 Void-containing component is synthetic resin or natural rubbers
• CPC Class Codes: Y10T 428/249978 Voids specified as micro
• CPC Class Codes: Y10T 428/24998 Composite has more than two layers
• CPC Class Codes: Y10T 428/249982 With component specified as adhesive or bonding agent
• CPC Class Codes: Y10T 428/249985 : Composition of adhesive or bonding component specified
• CPC Class Codes: Y10T 428/249986 : Void-containing component contains also a solid fiber or solid particle
• CPC Class Codes: Y10T 428/249987 : With nonvoid component of specified composition
• CPC Class Codes: Y10T 428/249991 : Synthetic resin or natural rubbers
• CPC Class Codes: Y10T 428/249992 : Linear or thermoplastic
• CPC Class Codes: Y10T 428/249993 : Hydrocarbon polymer
• CPC Class Codes: Y10T 428/25 : Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/256 : Heavy metal or aluminum or compound thereof
• CPC Class Codes: Y10T 428/259 : Silicic material
• CPC Class Codes: Y10T 428/31511 : Of epoxy ether
• CPC Class Codes: Y10T 428/31544 : Addition polymer is perhalogenated
• CPC Class Codes: Y10T 428/31699 : Ester, halide or nitrile of addition polymer
• CPC Class Codes: Y10T 428/31931 : Polyene monomer-containing

Abstract

An adhesive composite material comprises an expanded fluoropolymer with nodes and interconnected fibrils, the fluoropolymer having a void volume which is at least partially filled with a mixture containing a thermoset or thermoplastic adhesive and a particulate inorganic filler. The composite material contains sufficient adhesive and filler such that the composite contains between about 5 to about 40 volume percent expanded fluoropolymer; 5-85 volume percent inorganic filler; and 10-95 volume percent of adhesive and filler, the adhesive and filler being contained within the voids of the expanded fluoropolymer. In the composite, the ratio of the mean flow pore size of the expanded fluoropolymer to the largest particle size of the filler is at least about 2 and/or the ratio of the minimum pore size of the expanded fluoropolymer to the largest particle size of the filler is at least about 1.4.

Claims

1. A composite adhesive material comprising:

an expanded polytetrafluoroethylene film having a microstructure defined by nodes and fibrils, the film having an initial void volume and a mean flow pore size;

a mixture containing particulate filler and an adhesive, the mixture being evenly distributed throughout said void volume of said composite adhesive material, the particulate filler being a collection of individual particles, said collection containing a particle having a largest particle size which is the largest detectable particle in the collection;

wherein the ratio of mean flow pore size to the largest particle size is at least about 2.

2. The composite adhesive material according to claim 1, wherein said adhesive is a thermosetting or thermoplastic compound.

3. The composite adhesive material according to claim 2, wherein said adhesive is at least one of epoxy resin, cyanate ester resin or polybutadiene resin.

4. The composite adhesive material according to claim 1, wherein said particulate filler is at least one of SiO₂, TiO₂, or ZnO.

5. The composite adhesive material according to claim 4, wherein there are a plurality of expanded polytetrafluoroethylene films.

6. The composite adhesive material according to claim 5, wherein a metal layer is adhered to the composite adhesive material.

7. The composite adhesive material according to claim 1, wherein the composite contains 10-95 volume percent of said mixture of adhesive and filler within the voids of said expanded polytetrafluoroethvlene film.

8. The composite adhesive material according to claim 1, wherein the composite contains 5 to 85 volume percent filler material.

9. The composite adhesive material of claim 1, wherein the expanded polytetrafluoroethylene film has an initial void volume of at least 30 volume percent.

10. The composite adhesive material of claim 1, wherein the filler and adhesive are present in amounts such that the volume of said expanded polytetrafluoroethylene film is about 5 to about 40 volume percent of said composite adhesive material.

11. The composite adhesive material of claim 1, wherein the ratio of mean flow pore size to largest particle size is at least about 2.4.

12. The composite adhesive material of claim 11, wherein the ratio of mean flow pore size to largest particle size is at least about 5.

13. The composite adhesive material of claim 1, wherein the expanded polytetrafluoroethylene film has a minimum pore size, and wherein the ratio of minimum pore size to largest particle size is about 1.4.

14. A composite adhesive material comprising:

at least one porous polymer substrate layer comprising an expanded polytetrafluoroethylene film of nodes, fibrils, and pores, the film having a minimum pore size and having an initial void volume of at least 30 volume percent percent;

said void volume containing a mixture of adhesive and particulate filler, wherein the mixture is evenly distributed throughout said void volume of said substrate layer, said mixture being present in said substrate so that the volume of the polymer substrate is about 5 to about 40 volume percent of said composite, and said filler being a collection of individual particles, said collection containing a particle having a largest particle size which is the largest detectable particle in the collection;

wherein the ratio of minimum pore size to largest particle size comprises at least about 1.4.

15. The composite adhesive material of claim 14, wherein the expanded polytetrafluoroethylene film has a mean flow pore size and wherein the ratio of mean flow pore size to largest particle size is at least about 2.

16. The composite adhesive material of claim 15, wherein the ratio of mean flow pore size to largest particle size is at least about 2.4.

17. The composite adhesive material of claim 16, wherein the ratio of mean flow pore size to largest particle size is at least about 5.

18. A composite adhesive material comprising:

a microporous film having a microstructure defined by nodes and fibrils, the film having an initial void volume and a mean flow pore size;

a mixture containing particulate filler and an adhesive, the mixture being evenly distributed throughout said void volume of said composite adhesive material, the particulate filler being a collection of individual particles, said collection containing a particle having a largest particle size which is the largest detectable particle in the collection; and

wherein the ratio of mean flow pore size to the largest particle size is at least about 2.

19. A composite adhesive material comprising:

at least one porous polymer substrate layer having a microstructure defined by nodes and fibrils, the substrate layer having a minimum pore size and an initial void volume;

a mixture containing particulate filler and an adhesive, the mixture being evenly distributed throughout said void volume of said composite adhesive material, the particulate filler being a collection of individual particles, said collection containing a particle having a largest particle size which is the largest detectable particle in the collection; and

wherein the ratio of minimum pore size to largest particle size comprises at least about 1.4.