Rheological Investigations of Silver Paste Performance for Screen-Printing Application

• Main Authors: LEE, HSUN-CHENG, 李訓政
• Other Authors: Hua, Chi-Chung
• Format: Others
• Language: en_US
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/5u67sr

碩士 === 國立中正大學 === 化學工程研究所 === 105 === Rheological properties of conductive silver pastes play an important role in fabricating high-performance conducting fine lines (or patterns) for front-side metallization of multi-crystalline silicon solar cells via the screen-printing process. Still, correlating the paste composition and printing performance with its rheological properties remains a challenging task in general. In this study, detailed rheological characterizations, which include oscillatory stress/strain sweep, control-stress/strain frequency sweep, and 3-step (printing) simulation test, were employed to systematically reveal the rheological properties of four representative series of silver paste samples with varying composition of polymer binder (B), thixotropic agent (T), and their blending (B/T) ratio. The impacts on the screen-printing performances, as systematically characterized by Zeta finger profile, electroluminescence (EL) imaging, I-V characterization, and scanning electron microscopy (SEM) imaging, were also explored. Particular emphasis was put on exploring the individual effects of polymer binder, thixotropic agent, and their blending ratio. In this way, we showed that the correlation between paste rheology and screen-printing performance can be readily discerned, paving the way to optimal designs of paste samples for future screen-printing applications. Keywords: Rheology, Silver pastes, Polymer binder, Thixotropic agent, Screen-printing, Solar cells