Highly conductive copper nano/microparticles ink via flash light sintering for printed electronics
Highly conductive copper nano/microparticles ink via flash light sintering for printed electronics
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DOI：
10.1088/0957-4484/25/26/265601
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发表时间：
2014-07-04
期刊：
影响因子：
3.5
通讯作者：
Kim, Hak-Sung
中科院分区：
文献类型：
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作者：
Joo, Sung-Jun;Hwang, Hyun-Jun;Kim, Hak-Sung
以纳米铜颗粒(直径20~50 nm)和微米颗粒(直径2µm)为研究对象，研究了铜颗粒的尺寸对铜墨水闪光烧结的影响。制备了铜纳米/微米混合油墨，考察了纳米铜墨与微米油墨在闪光烧结中的协同效应。优化了铜墨水中纳米粒子与微粒的比例和几种闪光照射条件(照射能量密度、脉冲数、开启时间和关闭时间)，以获得高导电性的铜膜。为了对闪光烧结过程进行精确监测，利用实时惠斯通电桥电路、热电偶电路和高速数据采集系统，对闪光照射过程中铜薄膜的电阻和温度变化进行了现场监测。采用扫描电子显微镜、X射线衍射仪、X射线光电子能谱、傅立叶变换红外光谱等微观和光谱技术对闪光烧结铜纳米/微米薄膜进行了表征。此外，还用四探针法测量了铜膜的方阻。研究表明，纳米颗粒与微米颗粒的最佳比例为50：50wt%，制备的闪光烧结铜纳米/微米墨水薄膜的电阻率在纳米墨水、微墨墨水和纳米微米混合薄膜中最低(80mU欧米茄厘米)。
In this study, the size effect of copper particles on the flash light sintering of copper (Cu) ink was investigated using Cu nanoparticles (20-50 nm diameter) and microparticles (2 mu m diameter). Also, the mixed Cu nano-/micro-inks were fabricated, and the synergetic effects between the Cu nano-ink and micro-ink on flash light sintering were assessed. The ratio of nanoparticles to microparticles in Cu ink and the several flash light irradiation conditions (irradiation energy density, pulse number, on-time, and off-time) were optimized to obtain high conductivity of Cu films. In order to precisely monitor the milliseconds-long flash light sintering process, in situ monitoring of electrical resistance and temperature changes of Cu films was conducted during the flash light irradiation using a real-time Wheatstone bridge electrical circuit, thermocouple-based circuit, and a high-rate data acquisition system. Also, several microscopic and spectroscopic characterization techniques such as scanning electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy were used to characterize the flash light sintered Cu nano-/micro-films. In addition, the sheet resistance of Cu film was measured using a four-point probe method. This work revealed that the optimal ratio of nanoparticles to microparticles is 50:50 wt%, and the optimally fabricated and flash light sintered Cu nano-/micro-ink films have the lowest resistivity (80 mu Omega cm) among nanoink, micro-ink, or nano-micro mixed films.