Amine ligand, as one of the essential components of the Ag–amine complex, is necessary to reduce the sintering temperature and time of conductive inks. Herein, we report the facile preparation of hybrid amine conductive silver ink, mainly composed of silver oxalate–hybrid amine complex and methanol–acetone solvent. The synergistic effect of long-chain and short-chain amines enhances the uniformity of silver nanoparticles in the silver film. A uniformly conductive silver film is obtained by spin-coating as-prepared ink on the polyimide film, followed by thermal sintering. Then, the influence of butylamine content and sintering parameters on the physical properties and microstructure of silver film is systematically investigated. The resistivity of silver films, sintered at 170 °C for only 20 min, is found to be 6.71 μΩ·cm, which is four times higher than bulk silver. In addition, silver films after bending and adhesion test exhibit low resistivity and excellent adhesion. These results indicate that the hybrid amine conductive silver ink can provide promising opportunities for fabricating highly conductive flexible printed electronics at low temperatures in short times.
To solve the problems of high sintering temperatures (∼200 °C), particle aggregation, nozzle clogging, and poor shelf life of silver nanoparticle inks, we prepared a transparent and stable reactive silver ink for fabricating printed electronics. The ink mainly consisted of ammonia and formic acid ligands, silver acetate, and hydroxyethyl cellulose (HEC) adhesive agent. The highly conductive and flexible silver films were fabricated by printing and low temperature sintering the reactive silver ink, and the effects of sintering temperature and sintering time on the electrical properties of the printed silver films were investigated. Consequently, the printed silver film sintered at 70 °C exhibits good electrical properties with a resistivity of 12.1 μΩ·cm, which is only seven times higher than that of bulk silver (1.65 μΩ·cm). Moreover, the silver film also displays excellent adhesive strength and mechanical flexibility in terms of bending and twisting.
Direct ink writing (DIW) represents a technical branch of additive manufacturing technology, particularly suitable for prototyping or small-batch printing production of printed electronic components. However, the existing print heads required for near or sub-100 μm line width are quite sophisticated, limiting the accessibility and application of the DIW method. This paper reports the use of the vibrating membrane ejector (VME) as a new option for the print head of DIW. The structure of the VME-based print head was specially designed for this purpose. Finite element modeling and analysis of the VME's vibration characteristics were performed to provide insights into the ejection conditions and behaviors. The factors influencing the size of printed structures were identified and analyzed through the printing of a metal–organic complex silver (Ag) ink. After optimizing several operational parameters to limit the spreading effects and suppress the satellite droplets, the DIW printed line width has reached about 100 μm. The effectiveness of the VME-based print head was further demonstrated through the DIW fabrication of interdigitated electrodes and microstrip transmission lines. This highlights the versatility of the VME-based print head as a practical tool for device prototyping and ink development in the field of printed electronics.
危险品化学品经营许可证（带存储）