Paper Info
Title
Growth competition between layer-type and porous-type Cu3Sn in microbumps.
Abstract
Experimental study of growth competition between the co-existing layer-type and porous-type Cu3Sn in solder microbumps of Cu/SnAg/Cu is reported. The thickness of the SnAg solder is about 14μm and the Cu column on both sides is 20μm. Upon wetting-reflow, the solder is reacted completely to form CuSn intermetallic compounds in a multi-layered structure of Cu/Cu3Sn/Cu6Sn5/Cu3Sn/Cu. Upon further annealing at 220°C and 260°C, we obtain Cu/Cu3Sn/porous Cu3Sn/Cu3Sn/Cu, in which both types of Cu3Sn co-exist and form an interface. In the layer-type growth, we assume Cu to be the dominant diffusing species, coming from the Cu column. The Cu reacts with Cu6Sn5 to grow the Cu3Sn layer. In the porous-type growth, we assume Sn to be the dominant diffusing species, coming from the depletion of Sn in Cu6Sn5. The depleted Cu6Sn5 transforms to the porous-type Cu3Sn. At the same time, the Sn diffuses to the side-wall of Cu column to form a coating of Cu3Sn. Experimental observations of 3-dimensional distribution of voids in the porous-type Cu3Sn are performed by synchrotron radiation tomography; the voids are interconnected for the out-diffusion of Sn. The competing growth between the layer-type and the porous-type Cu3Sn is analyzed.
Year
DOI
Venue
2017
10.1016/j.microrel.2017.10.001
Microelectronics Reliability
Keywords
Field
DocType
Porous structure,Microbumps,Intermetallic compounds,Growth competition
Porosity,Intermetallic,Coating,Soldering,Annealing (metallurgy),Metallurgy,Engineering,Void (astronomy),Synchrotron radiation
Journal
Volume
ISSN
Citations 
79
0026-2714
0
PageRank 
References 
Authors
0.34
0
9
Name
Order
Citations
PageRank
David Chu1432.79
Yi-Cheng Chu200.34
Jie-An Lin300.34
Yi-Ting Chen423.42
Chun-Chieh Wang500.34
Yen-Fang Song600.34
Cheng-Cheng Chiang700.34
Chi Chen Chen831.49
King-Ning Tu9547.11