Effect of elements Ni and Co on morphology and type of IMC at Sn-3Ag-0.5Cu solder joint interface

MENG Gong-ge¹, TAKEMOTO Tadashi², NISHIKAWA Hiroshi²

1.School of Material Science & Engineering,Harbin University of Science and Technology,Harbin 150040,China;2.Joining and Welding Research Institute,Osaka University,Osaka 567-0047,Japan



Abstract:

The intermetallic compound (IMC) is hard and brittle,and its forming and growth at soldering joint interface is an important issue in joint reliability.The data obtained by digital optical electronic microscope indicate that the addition of element Co changes the IMC morphology from ball-like and bar-like to distinct and sharp in crest lines and edges.The addition of elements Ni and Co in Sn-3Ag-0.5Cu solder promotes the nucleation and makes the IMC size finer.The electron probe microanalysis (EPMA) determines the chemical compositions and confirms that the IMC is changed into the (Cu,Co,Ni)6Sn5+(Cu,Co,Ni)3Sn4 mixed type from the type of Cu6Sn5 with the elements Ni and Co in the solder.

Key words:  Sn-3Ag-0.5Cu solder  IMC  Ni/Co  morphology  type

DOI：10.11916/j.issn.1005-9113.2009.05.010

Clc Number:TG407

Fund: