Title :
Effect and experiment of screw locations on BGA viscoplastic fatigue life
Author :
Tian Wenchao ; Guan Rongcheng
Author_Institution :
Sch. of Electro-Mech. Eng., Xidian Univ., Xi´an, China
Abstract :
This paper establishes a packaging module of multichip with lead-free solder ball SAC305. BGA solder ball adopt nonlinear Anand viscoplasticity constitute formula. With the change factor of five screw locations, the dangerous solder ball position and stress-strain hysteresis curve are obtained through simulation with applying thermal cycling condition and screw prestress under the IPC9701 standard. Based on Coffin-Manson equation, the fatigue life of dangerous solder ball and the trend curve of solder ball life with the screw locations are deduced. And through experiments, the conclusion of the simulation is verified.
Keywords :
ball grid arrays; multichip modules; solders; stress-strain relations; viscoplasticity; BGA solder ball; BGA viscoplastic fatigue life; Coffin-Manson equation; IPC9701 standard; change factor; lead-free solder SAC305; multichip; nonlinear Anand viscoplasticity constitute formula; packaging module; screw locations; screw prestress; solder ball position; stress-strain hysteresis curve; thermal cycling condition; Equations; Fasteners; Fatigue; Mathematical model; Packaging; Strain; Stress; BGA; fatigue life; screw locations; solder ball life; thermal cycling;
Conference_Titel :
Electronic Packaging Technology (ICEPT), 2014 15th International Conference on
Conference_Location :
Chengdu
DOI :
10.1109/ICEPT.2014.6922711
