TY - JOUR
T1 - Interfacial Reactions between Ga and Cu-10Ni Substrate at Low Temperature
AU - Liu, Shiqian
AU - Zeng, Guang
AU - Yang, Wenhui
AU - McDonald, Stuart
AU - Gu, Qinfen
AU - Matsumura, Syo
AU - Nogita, Kazuhiro
N1 - Funding Information:
The authors are grateful for funding from the University of Queensland-Nihon Superior collaborative Research Program [Grant 2016001895], the Australian Research Council Linkage Project [Grant LP180100595] and the Australian synchrotron beamtime [Grant AS161PD10430]. The TEM experiments were supported by the Nanotechnology Platform Project for advanced nanostructure characterization [Grant JPMXP09-A-18-KU-0278A] sponsored by MEXT Japan, the Progress 100 program at Kyushu University (KU), and a “UQ-KU project” at the University of Queensland (UQ), which assists research collaborations between UQ and KU. The authors acknowledge the technical assistance of Centre for Microscopy and Microanalysis, The University of Queensland.
Funding Information:
The authors are grateful for funding from the University of Queensland-Nihon Superior collaborative Research Program [Grant 2016001895], the Australian Research Council Linkage Project [Grant LP180100595] and the Australian synchrotron beamtime [Grant AS161PD10430]. The TEM experiments were supported by the Nanotechnology Platform Project for advanced nanostructure characterization [Grant JPMXP09-A-18-KU-0278A] sponsored by MEXT Japan the Progress 100 program at Kyushu University (KU), and a "UQ-KU project" at the University of Queensland (UQ), which assists research collaborations between UQ and KU. The authors acknowledge the technical assistance of Centre for Microscopy and Microanalysis The University of Queensland.
Publisher Copyright:
© 2020 American Chemical Society.
PY - 2020/5/6
Y1 - 2020/5/6
N2 - Ga alloys have been attracting significant renewed attention for low-temperature bonding applications in electronic packaging. This study systematically investigates the interfacial reaction between liquid Ga and Cu-10Ni substrates at 30 °C. In addition to CuGa2 formed from binary Ga/Cu couples, a layer of nanocrystalline Ga5Ni and CuGa2 formed between the Cu-10Ni substrate and the blocklike micrometer scale CuGa2 layer. The growth of interfacial intermetallics (IMCs) on the Cu-10Ni substrate was substantially accelerated compared to the IMC growth in binary Ga/Cu couples. Reaction kinetics study shows the IMC growth from the Cu-10Ni substrate was controlled by reaction and volume diffusion, while the IMC growth from the Cu substrate was controlled by volume diffusion. It is also found that the presence of Ni within the CuGa2 phase resulted in improved thermal stability and a smaller coefficient of thermal expansion during heating from 25 to 300 °C, using synchrotron XRD analysis. There was least thermal expansion anisotropy among most of the IMCs that form in conventional Sn-based solder alloys, including Cu6Sn5 and so forth. It is concluded that using a Cu-10Ni substrate as opposed to a Cu substrate could achieve sufficient metallurgical bonding within shorter processing time. The results have implications for broadening the application temperatures when using Ga as a low-temperature joining material.
AB - Ga alloys have been attracting significant renewed attention for low-temperature bonding applications in electronic packaging. This study systematically investigates the interfacial reaction between liquid Ga and Cu-10Ni substrates at 30 °C. In addition to CuGa2 formed from binary Ga/Cu couples, a layer of nanocrystalline Ga5Ni and CuGa2 formed between the Cu-10Ni substrate and the blocklike micrometer scale CuGa2 layer. The growth of interfacial intermetallics (IMCs) on the Cu-10Ni substrate was substantially accelerated compared to the IMC growth in binary Ga/Cu couples. Reaction kinetics study shows the IMC growth from the Cu-10Ni substrate was controlled by reaction and volume diffusion, while the IMC growth from the Cu substrate was controlled by volume diffusion. It is also found that the presence of Ni within the CuGa2 phase resulted in improved thermal stability and a smaller coefficient of thermal expansion during heating from 25 to 300 °C, using synchrotron XRD analysis. There was least thermal expansion anisotropy among most of the IMCs that form in conventional Sn-based solder alloys, including Cu6Sn5 and so forth. It is concluded that using a Cu-10Ni substrate as opposed to a Cu substrate could achieve sufficient metallurgical bonding within shorter processing time. The results have implications for broadening the application temperatures when using Ga as a low-temperature joining material.
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U2 - 10.1021/acsami.0c02032
DO - 10.1021/acsami.0c02032
M3 - Article
C2 - 32272014
AN - SCOPUS:85084380130
SN - 1944-8244
VL - 12
SP - 21045
EP - 21056
JO - ACS Applied Materials and Interfaces
JF - ACS Applied Materials and Interfaces
IS - 18
ER -