Title :
Creep deformation of 96.5Sn-3.5Ag solder joints in a flip chip package
Author :
Yang, Hong ; Deane, Phillip ; Magill, P. ; Murty, K. Linga
Author_Institution :
MCNC, Research Triangle Park, NC, USA
Abstract :
As part of an investigation of using eutectic 96.5Sn-3.5Ag solder for flip chip interconnection, this paper presents the results on mechanical characterization of 96.5Sn-3.5Ag eutectic solder and solder joints. Constant-load creep tests of 96.5Sn-3.5Ag solder alloy were performed at high homologous temperatures from 25°C to 180°C. Single lap shear tests were performed on joined flip chip packages with an area array of 96.5Sn-3.5Ag solder bumps-33×33 bumps per chip. Tensile creep tests were performed on bulk 96.5Sn-3.5Ag solder specimens. The steady-state strain-rates span 7 orders of magnitude ranging from 10-9 to 10-2 (1/s). The apparent activation energy for creep was found to be 0.57 ev. The stress exponent in the power-law creep equation is ≈10 which is unusually high compared to that of many other metals. The underlying controlling mechanisms is identified as low-temperature dislocation climb
Keywords :
creep; dislocation climb; eutectic alloys; flip-chip devices; packaging; silver alloys; soldering; tin alloys; 25 to 180 C; 96.5Sn-3.5Ag eutectic solder; Sn-Ag; activation energy; constant-load creep test; creep deformation; dislocation climb; flip chip package; interconnection; mechanical characteristics; power-law equation; single lap shear test; solder joint; stress exponent; tensile creep test; Creep; Equations; Flip chip; Packaging; Performance evaluation; Soldering; Steady-state; Temperature; Tensile stress; Testing;
Conference_Titel :
Electronic Components and Technology Conference, 1996. Proceedings., 46th
Conference_Location :
Orlando, FL
Print_ISBN :
0-7803-3286-5
DOI :
10.1109/ECTC.1996.550880
