文献类型：期刊文献

英文题名：Crystallinity of Co-P coating on microstructure and mechanical properties of Co-Sn intermetallic compounds at Sn-Ag/Co-P/Cu Interface

作者：Liu, Shuang[1,2];Ma, Limin[1,2];Zhen, Cheng[1,2];Wang, Yishu[1,2];Li, Dan[1,2];Guo, Fu[1,2,3]

第一作者：Liu, Shuang

通讯作者：Ma, LM[1];Guo, F[1]

机构：[1]Beijing Univ Technol, Fac Mat & Mfg, Beijing 100124, Peoples R China;[2]Beijing Univ Technol, Key Lab Adv Funct Mat, Educ Minist China, Beijing 100124, Peoples R China;[3]Beijing Union Univ, Coll Robot, Beijing 100101, Peoples R China

第一机构：Beijing Univ Technol, Fac Mat & Mfg, Beijing 100124, Peoples R China

通讯机构：[1]corresponding author), Beijing Univ Technol, Fac Mat & Mfg, Beijing 100124, Peoples R China.

年份：2022

卷号：191

外文期刊名：MATERIALS CHARACTERIZATION

收录：;EI(收录号：20222912372933);Scopus(收录号：2-s2.0-85134179286);WOS:【SCI-EXPANDED(收录号:WOS:000880069400003)】；

基金：This work was financially supported by the Innovative Research Group Project of the National Natural Science Foundation of China (Grant 51621003), Beijing Municipal Science and Technology Project (Grant Z191100002019005). The authors were grateful for the financial supports.

语种：英文

外文关键词：Crystallinity; Cobalt-phosphorus coating; Solid-state diffusion; Co-Sn intermetallic compounds; Microstructure; Mechanical properties

摘要：In advanced microelectronic packaging technology, the interfacial brittleness of Cu/Sn solder joints puts forward higher requirements for high-performance diffusion barriers. Cobalt-Phosphorus (Co-P) alloy coating becomes ideal candidates for its good wettability and diffusion resistance. In this work, for Co-P with different crystallinity, the barrier properties of electrodeposited Co-P coatings as well as the mechanical properties of Co-Sn intermetallic compounds (IMCs) at the Co-P/Sn-Ag interface were investigated. According to the XRD results, the crystallinity of the Co-P coating was directly related to the phosphorus (P) content, and Co-P were classified into three types: crystalline state, mixed state and amorphous state. The morphology, composition, phase characterization, and mechanical properties of the Co-Sn IMCs at the interface were investigated by SEM, EPMA, TEM, and nanoindentation methods, respectively. After 180 degrees C aging test for 120 h, the thickness of CoSn3 generated at the interface of crystalline Co-4.2 at.% P/Sn-Ag was the smallest among a total of 18 Co-P coatings, where P content ranged from 0.9 at.% to 20.8 at.%, showing the best barrier properties. The hardness of (Co,Cu) Sn-3 at the amorphous Co-P/Sn-Ag interface was the lowest (3.2 GPa), which was only 47% of that of Ni3Sn4, exhibiting the lowest brittleness tendency. The mixed crystalline-amorphous Co-P could greatly improve the diffusion barrier properties while sacrificing a small degree of brittleness comparing to the amorphous coatings, and had the potential to become a general-purpose alloy coating. This work could provide a scientific basis for the selection of Co-P barrier layers with excellent barrier properties and mechanical properties leading to different application scenario in electronic packaging.