王春青 中国
电子封装 微连接
教授||博士生导师
目前就职材料科学与工程学院
所在学科 材料科学与工程 电子科学与技术
永久地址 http://homepage.hit.edu.cn/wangchunqing

Acta Materialia文章“3D柔性打印可低温钎焊金属间化合物纳米材料”

Acta Materialia 162 (2019) 163-175 doi:10.1016/j.actamat.2018.09.069 Full length article

This research was supported by NSFC under Grant 51374084

Low-temperature-solderable intermetallic nanoparticles for 3D printable flexible electronics

Ying Zhong, Rong An, Huiwen Ma, Chunqing Wang*

Functional materials for flexible and wearable smart devices have attracted much attention in recent years. This paper describes structure and properties of uniquely prepared, functional interconnectable nanoparticles (NPs) of Cu6Sn5 intermetallic compound that can allow 3D flexible packaging and nanocircuits. In situ TEM analysis confirms that size-controllable Cu6Sn5 NPs as small as ~6.40 nm can be made sinterable at the start temperature as low as ~130 °C, which is much lower than its bulk melting point (MP) of 415 °C. After sintering, its high MP provides mechanical and thermal stability. Based on the in situ TEM observation and calculation, particle size and distribution affects the sintering process. More interestingly, the relative orientations of adjacent particles also play an important role. A new orientation related sintering mechanism noted as orientation unification (OU) is revealed as two adjacent particles exhibit orientation change to slowly match their orientation with each other during the heating process. The interesting interaction between nano-Cu6Sn5 and micro-Cu substrate during in situ TEM heating gives first hand atomic level proof of the formation of Cu3Sn. The nano-Cu6Sn5 joints possess high enough bonding strength and great high temperature working capability. This intermetallic nanosoldering approach can pioneer a novel strategy of circuit connection, by providing high working temperature interconnection materials for 3D flexible packaging and ultra-high-density micro/nano interconnections.

Keywords: Solder, Cu6Sn5 nanoparticle, Intermetallic, Interconnection, In situ TEM

ACS AMI文章“一步法制备3D纳米锥阵列与纳米银烧接”

ACS Applied Materials & Interfaces 2017, 9, 4798−4807  doi:10.1021/acsami.6b13031

This research was supported by NSFC under Grant 51374084

One-Step Fabrication of 3D Nanohierarchical Nickel Nanomace Array To Sinter with Silver NPs and the Interfacial Analysis

Wei Zhou, Zhen Zheng, Chunqing Wang*, Zhongtao Wang, and Rong An

Three-dimensional (3D) nanohierarchical Ni nanomace (Ni NM) array was fabricated on copper substrate by only one step with electroplating method, the unique structure was covered with Au film (Ni/Au NM) without changing its morphology, and in the following step, it was sintered with silver nanoparticle (Ag NP) paste. The structure of the Ni NM array and its surface morphology were characterized by X-ray diffraction, scanning electron microscope (SEM), and atomic force microscope. The sintered interface was investigated by SEM, transmission electron microscopy, and energy-dispersive X-ray spectroscopy to analyze the sintering mechanism. The results showed that a metallurgical bond was successfully achieved at 250 °C without any gas or vacuum shield and extra pressure. The Cu substrate with Ni/Au NM array was able to join with the Ag NP paste without obvious voids. Due to the compatible chemical potential between Ag NPs and Ni/Au NM array, the Au element was able to diffuse into the Ag layer with about 800 nm distance. Based on the excellent 3D nanohierarchical structure, the shear strength of Ni/Au NM array was 6 times stronger than the flat Ni/Au coated substrate. It turned out that the substrate surface played a crucial role in improving the shear strength and sintering efficiency. The 3D Ni NM array had achieved an excellent bonding interface and had great potential application in the microelectronics packaging field.

KEYWORDS: nanomace array, silver nanoparticles, sintering, nanojoining, interface connection, interface analysis, shear strength



SMALL文章“低温烧结Cu6Sn5纳米焊膏:超塑性的高温电路互连材料”

SMALL 2015, 11, No. 33, 4097–4103  DOI: 10.1002/smll.201500896

This research was supported by NSFC under Grant 51374084

Low Temperature Sintering Cu6Sn5 Nanoparticles for Superplastic and Super-uniform High Temperature Circuit Interconnections

Ying Zhong, Rong An, Chunqing Wang,* Zhen Zheng, Zhi-Quan Liu, Chin-Hung Liu, Cai-Fu Li, Tae Kyoung Kim, Sungho Jin*

High temperature circuit interconnection materials are highly desirable as the power density and high temperature capabilities of present-day electronic devices are experiencing unprecedented growth due to their rapid multifunctionalization and miniaturization, especially the commercialization of wide band gap semiconductors such as silicon carbide (SiC) and gallium nitride (GaN). Although high melting point (MP) (e.g., >320 °C) solders such as Pb-, Au-, Zn-, Bi-based alloys can be utilized to provide high temperature resistance for the interconnection, they all have their own critical limitations such as toxicity, extremely high cost, poor corrosion resistance, and inferior electrical conductivity. Meanwhile, high MP alloys need higher processing temperatures to realize the melting and bonding, which may damage the circuits and substrates, especially when used in the packaging of currently burgeoning flexible and wearable devices. To address this problem, this paper proposes a novel category of circuit interconnection materials: nanoscaled intermetallics. Via nano route, Cu6Sn5 intermetallic nanoparticles (NPs) can act as the Holy Grail solution for the urgent hunger of high temperature bonding materials.


Applied Surface Science:晶态BLFMO/BSTCO双层薄膜增强铁电特性

Applied Surface Science 404 (2017) 162–167 do:10.1016/j.apsusc.2017.01.186

This research was supported by NSFC under Grant 51374084

Crystallized Bi0.9La0.1Fe0.95Mn0.05O3/Ba0.7Sr0.3Ti0.95Co0.05O3 bilayer thin films with enhanced multiferroic properties 

Bin Li, Chunqing Wang∗, Guangbin Dou∗, Zhenbin Wang, Weidong Fei

We report the synthesis of Bi0.9La0.1Fe0.95Mn0.05O3 (BLFMO) films with enhanced multiferroic properties and without second phase using Ba0.7Sr0.3Ti0.95Co0.05O3 (BSTCO) film as a buffer layer. Sol–gel processes were used to prepare the crystallized BLFMO/BSTCO films, in which magnetic domains were observed and no impurity phase was detected. We found that the buffer layer could effectively enhance the saturation magnetization and retentivity values of the BLFMO films, and especially the magnetic coercive field of these bilayer films was significantly stronger than that of the BLFMO films without buffer layers

Keywords: Multiferroics, Ferroelectricity, Magnetic properties, Perovskite


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