Formation of Kirkendall Voids at Low and High Aging Temperature in the Sn-0.7Cu-1.0wt.%Si3N4/Cu Solder Joints
The intermetallic compounds (IMCs) layer formed between Sn-0.7Cu-1.0wt.%Si3N4 (SC-1.0SN) solder and Cu-substrate were investigated through isothermal solid-state aging. The SC-1.0SN/Cu solder joints were aged at 50°C and 150°C for 24h, 240h, 480h and 720h duration after reflow. The as-soldered joint IMC formed at interface was Cu6Sn5. In addition, only Cu6Sn5 layer was observed at the interface of the samples aged at low temperature of 50°C although the aging duration was prolonged up to 720h and has begun to increase in thickness. On the other hand, the Cu3Sn layer was clearly observed in the sample of aged at 150°C up to 240h. However, at least no voids were vividly observed in the 50°C aged samples, while kirkendall voids were clearly found in Cu3Sn layer of samples aged at 150°C up to 480h of aging time will be discussed further.
Jedol Dayou, Azhan Hashim, Walter Charles Primus, Fuei Pien Chee, Mohamad Deraman and Roslan Abd-Shukor
N. Saud et al., "Formation of Kirkendall Voids at Low and High Aging Temperature in the Sn-0.7Cu-1.0wt.%Si3N4/Cu Solder Joints", Advanced Materials Research, Vol. 1107, pp. 577-581, 2015