Stress evolution during ultrasonic Al ribbon bonding

International Symposium on Interfacial Joining and Surface Technology 2013

Ando, Masaya^1 ; Takashima, Kazumasa^1 ; Maeda, Masakatsu^2 ; Takahashi, Yasuo^2

Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka

565-0871, Japan^1

Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka

567-0047, Japan^2

关键词: Bonding time;    Equivalent stress;    Friction force;    High speed video cameras;    Interfacial slip;    Si substrates;    Stress evolution;    Ultrasonic bonding;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/61/1/012005/pdf
DOI  :  10.1088/1757-899X/61/1/012005

来源: IOP

【 摘 要 】

The present study reveals the stress distribution in the substrate during ultrasonic bonding. The deformations of the Si substrate, Al ribbon, and Al pad were numerically analyzed using a finite element method. Experimental observation of the interface using a highspeed video camera was also conducted to determine the actual interfacial slip amplitude. This amplitude becomes smaller than that of tool-tip with bonding time. It was suggested from the numerical simulations that frictional adhesion enhanced the friction force, resulting in an increase in the equivalent stress in the ribbon and pad. As a result, very large stresses occur in the substrate during ultrasonic bonding. These stresses evolve with the progress of ultrasonic bonding, i.e., frictional adhesion.