Fabrication of photoimageable silver paste for low-temperature cofiring using acrylic binder polymers and photosensitive materials

Abstract

Thick-film photolithography is a new technology that combines lithography processes, such as exposure and development, with the conventional thick-film process applied to screen-printing. In this study, we developed a low-temperature cofireable silver paste applicable for thick-film processing to form fine lines using photolithographic technologies. The optimum paste composition for forming fine lines was investigated. The effect of processing parameters, such as the exposing dose, had on the fine-line resolution was also investigated. As the result, we found that the type of polymer and monomer, the silver powder loading, and the amount of photoinitiator were the main factors affecting the resolution of the fine lines. The developed photoimageable silver paste was printed on a low-temperature cofireable green sheet, dried, exposed, developed in an aqueous process, laminated, and then fired.Our results demonstrate that thick-film fine lines having widths < 20 μm can be obtained after cofiring.

Fabrication of embedded fine line inductors by constrained sintering and formulation of photoimageable conductive paste

“…Ultraviolet (UV) beam scattering is dependent on silver powder shape, powder size distribution and powder size, and optimised property regarding silver powder was determined to be powder with spherical type shape, narrow distribution of powder size and small particle size. 8 Smooth surface of paste enables higher resolution than rough surface condition due to reduced UV beam scattering and spray uniformity during development by aqueous solution. Figure 5 shows comparison of surface morphology of KETI paste with commercial paste by optical microscope.…”