Original scientific paper

Growth of the IMC at the interface of SnAgCuBi (Bi = 0,5; 1,0) solder joints with Cu substrate

Beáta Šimeková ; Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Institute of Production Technologies, Paulínska 16, 91701 Trnava, Slovakia
Erika Hodúlová ; Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Institute of Production Technologies, Paulínska 16, 91701 Trnava, Slovakia
Ingrid Kovaříková ; Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Institute of Production Technologies, Paulínska 16, 91701 Trnava, Slovakia
Marián Palcut ; Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Institute of Production Technologies, Paulínska 16, 91701 Trnava, Slovakia
Koloman Ulrich ; Slovak University of Technology in Bratislava, Faculty of Materials Science and Technology in Trnava, Institute of Production Technologies, Paulínska 16, 91701 Trnava, Slovakia

Abstract

The effects of Bi addition on the intermetallic phase formation in the lead-free solder joints of Sn-Ag-0.5Cu0.5Bi (SAC0,5B) and Sn-Ag-0.5Cu-1.0Bi (SAC1,0B), composition given in weight (measured in %), with copper substrate are studied. The soldering of the copper plate was conducted at 255 °C for 5 s. The joints were subsequently aged at temperatures of 100 °C, 130 °C and 160 °C for 1, 3, 7, 15 days in a convection oven. The aged interfaces were analysed by the optical microscopy and energy dispersive x-ray spectrometry (EDX, JEOL-JXA-840A) microanalysis. Two intermetallic layers are observed at the interface – Cu3Sn and Cu6Sn5. Cu6Sn5 is formed during soldering. Cu3Sn is formed during solid state ageing. Bi decreases the growth rate of Cu3Sn since it can possibly inhibit Sn diffusion along the grain boundaries. The mechanism of the Cu6Sn5 layer growth is discussed and the conclusions for the optimal solder chemical composition are presented.

Keywords

lead-free solder; intermetallic compound; annealing

Hrčak ID:

79165

URI

https://hrcak.srce.hr/79165

Publication date:

29.3.2012.

Article data in other languages: croatian

Visits: 2.005 *