Title :
Evaluation of ultrasonic vibration energy for copper-to-copper bonding by flip-chip bonding technology
Author :
Arai, Yutaro ; Miyamoto, Yutaka ; Nimura, Masatsugu ; Tomokage, Hajime
Author_Institution :
R&D Div., Toray Eng. Co., Ltd., Otsu, Japan
Abstract :
The ultrasonic vibration energy for Cu-Cu bonding by flip-chip bonding technology was evaluated in ambient air. Transmissibility of ultrasonic vibration is assumed to be different in bump structure with height or low stiffness. Therefore, we investigated the bonding strength of Cu bump with the different aspect ratio (bump height: 5 μm, 20 μm, and 40 μm). As a result, the Cu bumps with 20 μm height were properly bonded with sufficient bonding strength, compared with the others. In addition, there were no significant voids at Cu-Cu interface of well-bonded Cu bump.
Keywords :
copper; flip-chip devices; ultrasonic bonding; vibrations; Cu-Cu; Cu-Cu interface; aspect ratio; bonding strength; bump structure; copper-to-copper bonding; flip-chip bonding technology; size 20 mum; size 40 mum; size 5 mum; ultrasonic vibration energy; Acoustics; Bonding; Flip-chip devices; Plasma temperature; Scanning electron microscopy; Substrates; Vibrations; Cu bump; Cu-Cu bonding; Flip-chip bonding; Low temperature bonding; Ultrasonic vibration;
Conference_Titel :
Electronics Packaging (ICEP), 2014 International Conference on
Conference_Location :
Toyama
Print_ISBN :
978-4-904090-10-7
DOI :
10.1109/ICEP.2014.6826762
