Wang Zhenhe, Wang Dong, Zhang Chunbo, Chen Wei, Meng Qingjie, Yuan Hang, Yang Shiyong
Aerospace Institute of Advanced Materials & Processing Technology, Beijing 100074, China.
The Second Military Representative Office of the Air Force Equipment Department in Beijing, Beijing 100081, China.
Polymers (Basel). 2023 Feb 24;15(5):1150. doi: 10.3390/polym15051150.
Because of high conductivity, acceptable cost and good screen-printing process performance, silver pastes have been extensively used for making flexible electronics. However, there are few reported articles focusing on high heat resistance solidified silver pastes and their rheological properties. In this paper, a fluorinated polyamic acids (FPAA) is synthesized by polymerization of the 4,4'-(hexafluoroisopropylidene) diphthalic anhydride and 3,4'-diaminodiphenylether as monomers in the diethylene glycol monobutyl. The nano silver pastes are prepared by mixing the obtained FPAA resin with nano silver powder. The agglomerated particles caused by nano silver powder are divided and the dispersion of nano silver pastes are improved by three-roll grinding process with low roll gaps. The obtained nano silver pastes possess excellent thermal resistance with 5% weight loss temperature higher than 500 °C. The volume resistivity of cured nano silver paste achieves 4.52 × 10 Ω·m, when the silver content is 83% and the curing temperature is 300 °C. Additionally, the nano silver pastes have high thixotropic performance, which contributes to fabricate the fine pattern with high resolution. Finally, the conductive pattern with high resolution is prepared by printing silver nano pastes onto PI (Kapton-H) film. The excellent comprehensive properties, including good electrical conductivity, outstanding heat resistance and high thixotropy, make it a potential application in flexible electronics manufacturing, especially in high-temperature fields.
由于具有高导电性、可接受的成本和良好的丝网印刷工艺性能，银浆已被广泛用于制造柔性电子产品。然而，很少有报道关注高耐热性固化银浆及其流变性能。本文以4,4'-(六氟异丙基)二邻苯二甲酸酐和3,4'-二氨基二苯醚为单体，在二乙二醇单丁醚中聚合合成了含氟聚酰胺酸（FPAA）。将所得的FPAA树脂与纳米银粉混合制备纳米银浆。通过低辊隙三辊研磨工艺分散由纳米银粉引起的团聚颗粒，改善了纳米银浆的分散性。所得纳米银浆具有优异的耐热性，5%失重温度高于500℃。当银含量为83%且固化温度为300℃时，固化纳米银浆的体积电阻率达到4.52×10Ω·m。此外，纳米银浆具有高触变性，这有助于制备高分辨率的精细图案。最后，通过将银纳米浆印刷到PI（Kapton-H）薄膜上制备了高分辨率的导电图案。其优异的综合性能，包括良好的导电性、出色的耐热性和高触变性，使其在柔性电子制造中具有潜在应用，特别是在高温领域。
