Title :
Observation of Ultrasonic Al-Si Wire Wedge Bond Interface Using High Resolution Transmission Electron Microscope
Author :
Ji, Hongjun ; Li, Mingyu ; Kweon, Younggak ; Chang, Woongseong ; Wang, Chunqing
Author_Institution :
Harbin Inst. of Technol., Shenzhen
Abstract :
Due to small bond size, short bonding time, especially slight interface reaction, bonding details cannot be recognized using scanning electron microscope and energy density X-ray spectrum. In order to understand the physical mechanism of ultrasonic wedge bonding, in this paper, bond interface of ultrasonic AlSi wire wedge bonding on Au/Ni/Cu pad was investigated under high resolution transmission electron microscope. Au8Al3 intermetallic compounds were identified by convergent beam electron diffraction, thickness of which was about 200 nm and its lattice images were captured. Solid-state diffusion theory cannot be used to explain why such thick compound formed within milliseconds at room temperature. Ultrasonic effects attributed to formation of the metallurgical bonds.
Keywords :
aluminium alloys; copper; gold; integrated circuit interconnections; lead bonding; nickel; silicon alloys; transmission electron microscopy; ultrasonic bonding; AlSi-Au-Ni-Cu; bond size parameter; bonding time parameters; convergent beam electron diffraction; energy density X-ray spectrum; focus ion beam transmission electron microscope; integrated circuit interconnections; interface reaction; intermetallic compounds; lattice image capturing; metallurgical bond formation; solid-state diffusion theory; temperature 293 K to 298 K; ultrasonic effects; ultrasonic wire wedge bond interface; Bonding; Electron beams; Energy resolution; Gold; Image converters; Intermetallic; Scanning electron microscopy; Transmission electron microscopy; Wire; X-ray diffraction;
Conference_Titel :
Electronic Packaging Technology, 2007. ICEPT 2007. 8th International Conference on
Conference_Location :
Shanghai
Print_ISBN :
978-1-4244-1392-8
Electronic_ISBN :
978-1-4244-1392-8
DOI :
10.1109/ICEPT.2007.4441433
