Anisotropically conductive polymeric matrix

• US 5,049,085 A
• Filed: 02/05/1991
• Issued: 09/17/1991
• Est. Priority Date: 12/22/1989
• Status: Expired due to Fees

• Current Assignee: 3M Company
• Original Assignee: 3M Company
• Inventors: Berg, James G., Reylek, Robert S.
• Primary Examiner(s): Abrams, Neil
• Application Number:
  US07/652,213
• Time in Patent Office: 224 Days
• Field of Search: 339/17 M, 339/17 LM, 339/17 F, 339/59 M, 339/61 M, 339/DIG. 3, 29/830, 29/840, 29/849, 29/852, 29/883, 29/884, 174/117 A, 174/84 R, 174/88 R, 174/94 R, 439/65, 439/66, 439/74, 439/91, 439/591
• US Class Current: 439/91
• CPC Class Codes: H01R 13/2414 conductive elastomers
• CPC Class Codes: H01R 43/00 Apparatus or processes specially adapted for manufacturing, assembling, maintaining, or repairing of line connectors or current collectors or for joining electric conductors of trolley lines B60M1/28

Abstract

An anisotropically conductive polymeric matrix comprising a polymeric layer having conductive members extending substantially through the thickness thereof, said conductive members comprising a coating of a conductive material, and a process for making same.

Claims

1. An anisotropically conductive polymeric matrix comprising a polymer layer having a plurality of electrically conductive members therethrough, spaced such that at least some of said members are electrically isolated from one another, said members being at least partically tubular and comprising a deformable coating of an electricallty conductive material formed in shapes which extend from one face of said layer substantially through the thickness thereof, such shapes resulting from the use of removable forming means, whereby electric current can be conducted through the thickness of said polymeric layer by said members.

2. The conductive polymeric matrix of claim 1 wherein said conductive material consists of a metal selected from the group consisting of aluminum, copper, nickel, silver, gold, tin, and palladium.

3. The conductive polymeric matrix of claim 2 wherein said metal has a thickness from about 100 angstroms to about 250,000 angstroms.

4. The conductive polymeric matrix of claim 1 wherein said polymeric layer comprises an elastomer.

5. The conductive polymeric matrix of claim 1 wherein said polymeric layer comprises an adhesive.

6. The conductive polymeric matrix of claim 5 wherein said adhesive is selected from a polyester and a polyamide adhesive having a glass transition temperature of from about -20°

C. to about 200°

C.

7. The conductive polymeric matrix of claim 5 wherein said adhesive comprises a curable epoxy resin.

8. The conductive polymeric matrix of claim 5 wherein said adhesive comprises a hot tackifying adhesive which exhibits a probe tack value of at least 75 grams of force at 40°

C. or more.

9. The conductive polymeric matrix of claim 5 wherein said adhesive comprises one or more acrylic polymers andan acrylic ester monomer provides at least 50 mol percent of the one or more acrylic polymers of said at least one adhesive layer;

2) said one or more acrylic polymers have a T_g or a weight-averaged T_g of -10°

to 80°

C., and

3) said at least one layer has

a) a Probe Tack Value of less than 75 gf at 20°

C.,

b) Probe Tack Values of at least 75 gf over a range of at least 50°

C., which values remain substantially constant after 30 days at 40°

C., and

c) a Shear Value of at least 25 minutes at 65°

C., and

said at least one layer adheres well to a clean substrate upon contact at any temperature within said 50°

C. range.

10. The conductive polymeric matrix of claim 9 wherein said acrylic polymers are comprised of one or more acrylic copolymers of monomers, up to 50 mol % of which is at least one copolymerizable monomer selected from acrylic acid, methacrylic acid, itaconic, acid, maleic acid, maleic anhydride, amides of said acids, acrylonitrile, methacrylonitrile, and N-vinyl-2-pyrrolidone.

11. The conductive polymeric matrix of claim 9 wherein said acrylic ester monomer is selected from alkyl acrylates having 1-8 carbon atoms in their alkyl groups, alkyl methacrylates having 1-8 carbon atoms in their alkyl groups, bornyl acrylates, bornyl methacrylates, 2-phenoxyethyl acrylate, 2-phenoxymethyl acrylate, the mono- and di-methyl and ethyl esters of itaconic acid, and the mono- and di-methyl and ethyl esters of maleic acid.

12. The conductive polymer matrix of claim 9 in which at least one of styrene, vinyl acetate and vinyl chloride comprises up to 5 mol percent of the total monomers.

13. The conductive polymeric matrix of claim 1 wherein said conductive members have an aspect ratio of from about 1 to 10 to 10 to 1.

14. The conductive polymeric matrix of claim 1 wherein said conductive members having a conductive aspect ratio of from about 2 to 1 to 2000 to 1.

15. A transfer tape wound upon itself in roll form comprising the conductive polymeric matrix of claim 1 on a flexible release backing.

16. An electrical connector tape wound upon itself on roll form and comprising a flexible backing having, on a major face thereof;

a) a plurality of conductive stripes in laterally spaced relation and

b) the polymeric matrix of claim 1 covering said major face.

17. An electronic assembly comprising a first electronic component having a surface with a plurality of conductive areas and a second electronic component having a surface with a plurality of conductive areas wherein the two surfaces are adhered to one another by the polymeric matrix of claim 1 to thereby allow the conductance of an electric current from said first component to said second component, but not between said conductive areas of each individual component.

18. The conductive polymeric matrix of claim 1 wherein the electrically conductive members are uniformly spaced.

19. The conductive polymeric matrix of claim 1 wherein the electrically conductive members are fully tubular.

20. The conductive polymeric matrix of claim 1 wherein the electrically conductive members are of substantially uniform height in the thickness direction of the matrix.

21. The conductive polymeric matrix of claim 1 wherein said polymeric layer comprises pressure-sensitive adhesive.

22. The conductive polymeric matrix of claim 1 wherein said shapes are cones, pyramids, or hemispheres.

23. The conductive polymeric matrix of claim 19 wherein the edge surface of each of said tubular members defines at least one corner.

24. A conductive polymeric matrix comprising an electrically insulative polymeric layer having a plurality of electrically conductive members therethrough, said conductive members being spaced from each other, said members comprising a deformable coating of an electrically conductive material extending from one face of said layer substantially through the thickness thereof, said members being formed in shapes which result from the use of removable forming means.

25. The conductive polymeric matrix of claim 24 wherein substantially all of said electrically conductive members are electrically isolated from one another.

26. The conductive polymeric matrix of claim 24 wherein said shapes are cones, pyramids, or hemispheres.