Electrically conductive heat-activated adhesive compound

• US 9,593,264 B2
• Filed: 07/10/2012
• Issued: 03/14/2017
• Est. Priority Date: 08/10/2011
• Status: Active Grant

• Current Assignee: Tesa SE (Maxingvest AG)
• Original Assignee: Tesa SE (Maxingvest AG)
• Inventors: Keite-Telgenbscher, Klaus
• Primary Examiner(s): McNally, Daniel
• Application Number:
  US14/236,269
• Publication Number:
  US 20140216644A1
• Time in Patent Office: 1,708 Days
• US Class Current: 1/1
• CPC Class Codes: C08K 3/04 Carbon
• CPC Class Codes: C08K 3/08 Metals
• CPC Class Codes: C08K 7/04 inorganic
• CPC Class Codes: C09J 11/04 inorganic
• CPC Class Codes: C09J 2203/326 for bonding electronic components such as wafers, chips or semiconductors
• CPC Class Codes: C09J 2301/314 the adhesive layer and/or the carrier being conductive
• CPC Class Codes: C09J 2301/408 additives as essential feature of the adhesive layer
• CPC Class Codes: C09J 2400/16 Metal
• CPC Class Codes: C09J 2400/22 Presence of unspecified polymer
• CPC Class Codes: C09J 5/06 involving heating of the applied adhesive
• CPC Class Codes: C09J 7/10 without carriers
• CPC Class Codes: C09J 7/35 Heat-activated
• CPC Class Codes: C09J 9/02 Electrically-conducting adhesives
• CPC Class Codes: H01B 1/22 the conductive material comprising metals or alloys
• CPC Class Codes: H05K 3/321 by conductive adhesives

Abstract

An adhesive film, which can be bonded when heat-activated, comprising a) a polymer-metal blend comprising at least one adhesive which can be bonded when heat-activated, and at least one metal component melting in the temperature range from 50° C. to 400° C., and b) at least one fibrous, electrically conductive filler, the filler being present at least partly in the form of a bound fiber network with the metal component.

Claims

1. An adhesive film, bondable when heat-activated, comprising

a) a polymer-metal blend comprising

at least one adhesive, bondable when heat-activated, and

at least one metal component meltable in the temperature range from 50°

C. to 400°

C., and

b) at least one fibrous, electrically conductive filler,

wherein the at least one fibrous, electrically conductive filler is present, at least partly, in a form of a bound fiber network with the at least one metal component such that fibers of the at least one fibrous, electrically conductive filler are present in a form bound to one another by the at least one metal component, and

further wherein the at least one fibrous, electrically conductive filler comprises aluminum, copper, silver, gold, nickel, mu-metal, alnico, permalloy, ferrite, carbon nanotubes and graphene.

2. The adhesive film according to claim 1, wherein fibers of the at least one fibrous, electrically conductive filler have an aspect ratio of at least 3, wherein the aspect ratio is a ratio between a greatest longitudinal extent and a small longitudinal extent of the fibers.

3. The adhesive film according to claim 2, wherein the aspect ratio of the fibers is at least 10.

4. The adhesive film according to claim 2, wherein fibers of the at least one fibrous, electrically conductive filler have a fiber length from 1 to 10 mm.

5. The adhesive film according to claim 1, wherein at least one of the at least one fibrous, electrically conductive fillers is a carbon modification or a carbon-containing chemical compound.

6. The adhesive film according to claim 5, wherein the at least one fibrous, electrically conductive filler consists of copper-coated carbon fibers or nickel-coated carbon fibers.

7. The adhesive film according to claim 1, wherein the at least one fibrous, electrically conductive filler comprises at least one selected from copper and nickel.

8. The adhesive film according to claim 7, wherein the at least one fibrous, electrically conductive filler consists of coppered aluminum fibers or nickeled aluminum fibers.

9. The adhesive film according to claim 1, wherein the fibers of the at least one fibrous and regions formed by the at least one metal component are aligned in a first direction or orientation.

10. The adhesive film according to claim 9, wherein the first direction or orientation is substantially perpendicular to the plane of the adhesive film.

11. The adhesive film according to claim 1, wherein the at least one metal component is a metal or a metal alloy.

12. The adhesive film according to claim 1, wherein the at least one adhesive, bondable when heat-activated, is a heat-activatable thermoplastic adhesive.

13. The adhesive film according to claim 1 aims, wherein the at least one adhesive, bondable heat-activated, is a heat-activatable reactive adhesive.

14. The adhesive film according to claim 1, wherein fibers of the at least one fibrous, electrically conductive filler have a fiber length between 0.1 and 0.9 mm.

15. The adhesive film according to claim 1, wherein the fibers of the at least one fibrous have a thickness of at least 60 μ

m and no more than 180 μ

m.

16. A method for adhesive bonding on a first substrate surface, the method comprising:

bonding the first substrate by means of the adhesive film according to claim 1, which is heat-activated for bonding on the first substrate.

17. The method according to claim 16, further comprising:

bonding a surface of the first substrate to a surface of a second substrate by means of the adhesive film that has been heat-activated.

18. The method according to claim 17, wherein

first of all the adhesive film is subjected to a preliminary fastening onto the surface of the first substrate, by the adhesive film being activated at a temperature below the melting temperature of the metal component;

and

thereafter a final fixing is brought about, by the adhesive film being activated on the surface of the first substrate, or in a final disposition between the surfaces of the first and second substrates, at a temperature above the melting temperature of the metal component.

19. The method according to claim 16, wherein the heat the activation of the adhesive film is performed at a temperature below the melting temperature of the metal component.

20. The method according to claim 16, wherein the adhesive bonding is brought about by means of the adhesive film, which can be bonded when heat-activated, and the filler is oriented by means of a magnetic field before or during the activation.