Title :
Preliminary study of a new process to improve the strength of thermo-sonic ball solder joint
Author :
Yu, Zhai ; Wang, Zhao ; Cheng, Jun ; Tian, Hw
Author_Institution :
ShenZhen Inst. of Adv. Integration Technol., Chinese Univ. of Hong Kong, Shenzhen, China
Abstract :
The separation of golden ball and die pad due to the poor bonding strength of 1st ball solder joint is the main failure mode in thermo-sonic ball wire bonding. In this paper, nonlinear elastic and elasto-plastic quasi-static analysis of FAB (free air ball) in ultrasonic vibration process is carried out by finite element method with ANSYS. We study the evolution way of compressive stress distributions of FAB and sliding area in the contact interface under elastic and elasto-plastic deformation. According to the results of the analysis and the mechanism of micro-slip based on elastic theoretical assumption, we propose a new bonding process control that can improve the bonding strength of 1st ball solder joint effectively.
Keywords :
compressive strength; elastic deformation; elastoplasticity; electronics packaging; failure analysis; finite element analysis; lead bonding; mechanical strength; reliability; slip; soldering; ANSYS; bonding process control; bonding strength; chip package reliability; compressive stress distribution; die pad; elasto-plastic deformation; elasto-plastic quasistatic analysis; finite element method; free air ball analysis; golden ball; microslip mechanism; nonlinear elastic analysis; thermo-sonic ball solder joint; ultrasonic vibration process; wire bonding; Analytical models; Bonding forces; Bonding processes; Chemical analysis; Compressive stress; Finite element methods; Plastics; Soldering; Vibrations; Wire;
Conference_Titel :
Electronic Packaging Technology & High Density Packaging, 2009. ICEPT-HDP '09. International Conference on
Conference_Location :
Beijing
Print_ISBN :
978-1-4244-4658-2
Electronic_ISBN :
978-1-4244-4659-9
DOI :
10.1109/ICEPT.2009.5270649
