Please use this identifier to cite or link to this item:
標題: Synergetic effect of Bi2Te3 alloys and electrodeposition of Ni for interfacial reactions at solder/Ni/Bi2Te3 joints
作者: Chih-Fan Lin
Nga Yu Hau
Yu-Ting Huang
Ya-Huei Chang
Shien-Ping Feng
Chih-Ming Chen
關鍵字: Thermoelectric;Electroplating;Surface modification;Microstructure;Diffusion barrier
Project: Journal of Alloys and Compounds, Volume 708, 25 June 2017, Pages 220-230
Ni is the most commonly used barrier in thermoelectric solder joints, and its role is to avoid excessive reaction between the bismuth telluride (Bi2Te3) element and the Sn-based solder. This study, for the first time, demonstrates a strong effect of the Bi2Te3 substrate on the electrodeposition of Ni layer, consequently affecting the interfacial reaction with the Sn-4 wt.% Ag-0.5 wt% Cu (SAC405) solder. Two types of Bi2Te3 substrates, prepared using zone-melting and ball-milling/hot-pressing methods, exhibit different crystal structures, and this structural difference significantly affects the microstructures of the Ni diffusion barrier electroplated on the Bi2Te3 substrates and the growth of their intermetallic compound (IMC) at the SAC405/Ni/Bi2Te3 solder joints. The Ni layer electroplated on a zone-melted Bi2Te3 substrate (anisotropic crystal structure) has a small grain size and a high grain-boundary density, and one IMC, (Cu,Ni)6Sn5, is formed at the interface between SAC405 and Ni after joining. The other (Ni,Cu)3Sn4 phase is formed at the (Cu,Ni)6Sn5/Ni interface after thermal aging and grows at a progressively faster rate with increasing aging time. In contrast, the Ni layer electroplated on a ball-milled/hot-pressed Bi2Te3 substrate (isotropic crystal structure) has a large grain size and a low grain-boundary density, and only the (Cu,Ni)6Sn5 phase is formed at the SAC405/Ni interface, with a very sluggish growth rate after joining and thermal aging. Since the IMCs are electrically resistive and mechanically brittle, the latter solder joint with a large-grained Ni layer on a ball-milled/hot-pressed Bi2Te3 substrate appears to have better reliability.
DOI: 10.1016/j.jallcom.2017.02.300
Appears in Collections:化學工程學系所

Files in This Item:
File Description SizeFormat Existing users please Login
1-s2.0-S092583881730748X-main.pdf期刊論文5 MBAdobe PDFThis file is only available in the university internal network    Request a copy
Show full item record

Google ScholarTM




Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.