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MULTILAYER THIN FILM METALLURGIES FOR I/O PIN ATTACHMENT

IP.com Disclosure Number: IPCOM000014774D
Original Publication Date: 2001-May-03
Included in the Prior Art Database: 2003-Jun-20
Document File: 1 page(s) / 53K

Publishing Venue

IBM

Abstract

Multilayer thin film metallurgies have been designed and fabricated for I/O pin attachment, seal cap soldering, heat sink attachment and a number of other joining applications. Alloys, such as Au-20%Sn braze, solders, such as the Pb-(5-60%)Sn, etc., have been commonly used as the joining materials. The thin film metallurgies invented and developed for these joining applications consist of three layers: an adhesion layer, a reaction/wettable layer and a gold (Au) top layer. The adhesion layer uses one of the refractory metals from such element of Cr, Zr, Ta, V, Nb, or Hf at a thickness ranging from 50-3,000 angstrons. For the reaction/wettable layer, the metals that have demonstrated good reaction and wettabl property with braze and solder are Ni, Co, and Pd. The thickness of this layer ranges from 0.2 to 20 microns. The top layer (the surface layer) is made of gold at thickness ranging from 0.05 to 10 microns. The three layer structure is shown below. Adhesion Reaction/Wettable Surface Layer Layer Layer

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MULTILAYER THIN FILM METALLURGIES FOR I/O PIN ATTACHMENT

  Multilayer thin film metallurgies have been designed and fabricated for I/O pin attachment, seal cap soldering, heat sink attachment and a number of other joining applications.

Alloys, such as Au-20%Sn braze, solders, such as the Pb-(5-60%)Sn, etc., have been commonly used as the joining materials. The thin film metallurgies invented and developed for these joining applications consist of three layers: an adhesion layer, a reaction/wettable layer and a gold (Au) top layer. The adhesion layer uses one of the refractory metals from such element of Cr, Zr, Ta, V, Nb, or Hf at a thickness ranging from 50-3,000 angstrons. For the reaction/wettable layer, the metals that have demonstrated good reaction and wettabl property with braze and solder are Ni, Co, and Pd. The thickness of this layer ranges from 0.2 to 20 microns. The top layer (the surface layer) is made of gold at thickness ranging from 0.05 to 10 microns. The three layer structure is shown below.

Adhesion Reaction/Wettable Surface

Layer Layer Layer

Cr Ni Au

Zr Pd

Ta Pt

V Cu

Nb

Hf

The three layer thin film metallurgies can be manufactured with photolithographically defined patterning, a line-of-sight metal evaporation, sputtering or plating technique.

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