Silver Ink Postprocessing Resistivity Optimization
Abstract
The use of 3-D printing has gained a great deal of attention in multiple industries. The ability to create novel devices and structures in 3-D opens a range of applications that were previously not possible or prohibitively expensive. These 3-D printed materials very often do not have the same properties of their bulk counterparts. In this work, we examine the optimization of the postprocessing treatment of silver (Ag) printed ink. With the goal of minimizing the resistivity, in particular for high-frequency applications such as RF. Several approaches were investigated using temperature and/or local environment to control the sintering behavior of Ag ink. Both the atmosphere and energetics (plasma) of the atmosphere were examined in conjunction with temperature. The Ag inks were examined using X-ray diffraction, scanning electron microscopy, and a four-point probe to measure electrical resistivity. It was found that both temperature and gas environment had significantinfluences on the final ink resistivity. The use of multiple gasses lead to the best resistivity of 2.09E-8 ohm-m. Samples were annealed in air at 325 deg C followed by a cool-down in a nitrogen (N2) environment. It is postulated that the presence of air is necessary initially to decompose the organic ligands surrounding the Ag nanoparticles in the ink. The use of N2 during the cool-down was to prevent the formation of silver oxide. The oxide is not present at 325 deg C, as it decomposes at temperatures greater than 200 deg. So by cooling in N2, oxidation can be prevented and minimize the resistivity.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 30, 2021
- Accession Number
- AD1146318
Entities
People
- Jian Yu
- Thomas Parker
Organizations
- United States Army Research Laboratory