Improvement on Conducting of Thick-Film Aluminum Paste

Abstract

With the development of thick-film paste silver and copper are circulating in the market as the electric conductive fillings currently Unfortunately the cost of silver is exceedingly high while the copper has to be sintered in the reducing atmosphere In this study we proposed to exert aluminum as the filling due to its low cost good electrical conductivity and capability of being sintered in air By means of the fracture mechanism of the oxidation layer of the Al surface and the liquid phase sintering the Al paste with high solid content is used to implement high electrical conductivity In the first place based on the mechanism that Al powder with large particle size tends to fracture easily while it is easy for Al powder with small size to fill the gap we mixed Al powder with large and small particle sizes at different proportion so that the internal micro-structure and the oxidization condition could be observed Next with different ratios of Al powder and glass grit we observed glass frit to wet the Al particles the microstructure and the ability to inhibit oxidation After obtaining the ratio of Al particles and the ratio of Al powder and glass grit the solid content was raised proportionally Finally the optimal electrical resistance was obtained through various sintering parameters In this study we applied Thermogravimetric Analyzer (TGA) SEM and FIB to contrast and explain the experimental results By experiments and analysis the optimal ratio of Al particles (4:1) and the ratio of Al powder and glass frit (10:1) were obtained to raise solid content With those two results we raised the content of Al powder to 80% proportionally; then in collaboration with the temperature raising rate at 50℃/min(or 100℃/min) the sintering temperature at 850℃ and temperature hold time for 10 minutes the optimal sheet resistance 1mΩ/□ was got

Date of Award	2015 Aug 24
Original language	English
Supervisor	Wen-Shi Lee (Supervisor)