Method of forming an electrical contact and method of forming a chip package with a metal contact structure and protective layer

Patent metadata

Field	Value
Publication number	US-10978418-B2
Application number	US-201916572626-A
Country	US
Kind code	B2
Filing date	Sep 17, 2019
Priority date	May 20, 2016
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

A method of forming an electrical contact and a method of forming a chip package are provided. The methods may include arranging a metal contact structure including a non-noble metal and electrically contacting the chip, arranging a packaging material, and a protective layer including or essentially consisting of a portion formed at an interface between a portion of the metal contact structure and the packaging material, wherein the protective layer may include a noble metal, wherein the portion of the protective layer may include a plurality of regions free from the noble metal, and wherein the regions free from the noble metal may provide an interface between the packaging material and the non-noble metal of the metal contact structure.

First claim

What is claimed is:

1. A method of forming an electrical contact, comprising:
arranging an intermediate layer directly on a metal surface;
arranging a metal contact structure over or on the metal surface; and
plating a metal layer on the metal surface and on the metal contact structure, thereby fixing the metal contact structure to the metal surface and forming an electrical contact between the metal contact structure and the metal surface or strengthening or thickening an existing electrical contact between the metal contact structure and the metal surface.

2. The method of claim 1 , further comprising:
before plating the metal layer on the metal surface and on the metal contact structure, treating the metal surface and the metal contact structure by a process involving wet chemistry, dry chemistry, and/or a plasma in order to prepare a surface of the metal surface and of the metal contact structure for the plating.

3. The method of claim 1 , wherein the metal contact structure, the metal surface and/or a metallization material comprises or consists of copper.

4. The method of claim 1 , wherein the metal contact structure may contain or consist of a same metal as the metal surface.

5. The method of claim 3 , wherein the metallization comprises a galvanic deposit or an electroless deposit.

6. The method of claim 5 , further comprising:
an annealing process after metallization.

7. The method of claim 6 , wherein the annealing process comprises of a temperature range between 250° C. and 420° C.

8. The method of claim 3 , wherein the metallization comprises simultaneously growing the metal layer on the metal contact structure and the metal surface.

9. The method of claim 1 , further comprising:
prior to arranging the metal contact structure, arranging the intermediate layer directly on the metal surface.

10. The method of claim 9 , wherein the arranging the intermediate layer comprises arranging the intermediate layer as a structured intermediate layer.

11. The method of claim 9 , wherein the intermediate layer comprises an adhesion promoter and the arranging the metal contact structure comprises arranging the metal contact structure on or in or partially in the adhesion promoter.

12. The method of claim 9 , wherein the arranging the intermediate layer comprises deposition, stencil printing, or screen printing.

13. The method of claim 9 , wherein the intermediate layer is configured to prevent a plating of metal on the intermediate layer.

14. The method of claim 9 , wherein the intermediate layer comprises a metal paste or emulsion.

15. The method of claim 1 , further comprising: after arranging the metal contact structure, arranging a final protection layer on the metal surface and on the metal contact structure.

16. The method of claim 1 , further comprising: after establishing the metal contact structure, establishing a final protective layer on the metal surface and on the metal contact structure.

17. The method of claim 16 , further comprising: prior to establishing the final protective layer, cleaning and/or conditioning the metal layer to adjust its surface properties.

18. The method of claim 1 , wherein the metal contact structure is set up such that the metal contact structure is not in contact with the metal surface.

19. The method of claim 18 , wherein the metal contact structure has a distance from the metal surface of less than or equal to 3 μm.

20. The method of claim 1 , wherein arranging the metal contact structure comprises soft bonding between the metal contact structure and the metal surface.

Assignees

• Infineon Technologies Ag

Inventors

• Mahler Joachim
• Bauer Michael
• Dangelmaier Jochen
• Engl Reimund
• Gatterbauer Johann
• Hille Frank
• Huettinger Michael
• Kanert Werner
• Koerner Heinrich
• Ruehle Brigitte
• Santos Rodriguez Francisco Javier
• Vellei Antonio

Classifications

• H10W72/522

  Multilayered bond wires, e.g. having a coating concentric around a core · CPC title

• H10W72/5522

  comprising gold [Au] · CPC title

• H10W72/01515

  Forming coatings · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title