Conception of a consumable copper reaction zone for a NiTi/SnAgCu composite material

Olivier Fouassier (1) , Jean Chazelas (2) , Jean-François Silvain (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 THALES Airborne Systems [Elancourt]

Copper coated NiTi particles have been incorporated into a lead free solder paste in order to improve mechanical performances of solder joints. In order to optimise the thickness of the copper coating, interfacial reactions between Sn-3.8Ag-0.7Cu (wt%) and copper substrate have been studied. Auger Electron Spectroscopy linescan profile across the copper substrate and the Sn-3.8Ag-0.7Cu matrix interface has shown that the reaction layer is composed of Cu3Sn and Cu6Sn5 intermetallics. The formation and growth of this layer has been discussed. Finally the diffusion constant and activation energy for the diffusion of copper in the liquid and solid Sn-3.8Ag-0.7Cu matrix have been determined.

Mots clés: Lead-free solder; Nickel titanium (NiTi); Shape memory alloy; Metal matrix composite; Electroless copper coating; Interfacial study

Domaines: Matériaux

Olivier Fouassier, Jean Chazelas, Jean-François Silvain. Conception of a consumable copper reaction zone for a NiTi/SnAgCu composite material. Composites Part A: Applied Science and Manufacturing, 2002, 33 (10), pp.1391-1395. ⟨10.1016/S1359-835X(02)00154-9⟩. ⟨hal-00817141⟩