Effect of MgO powder addition to alkali and alkaline-earth borosilicate glass paste on the acid durability and peel adhesion characteristics of Ag conductors formed with the glass paste

Abstract

In this study, we investigated the influence of the addition of MgO powder to the alkali and alkaline-earth borosilicate (AEB) glass paste on acid durability and peel adhesion characteristics of Ag conductors formed on the alumina substrate with the AEB glass paste. It was determined that the addition of the MgO powder to the AEB glass paste promoted crystal precipitation during the firing process of the printed AEB glass thick-film on the substrate at 850 °C. By characterizing the acid corrosion behavior in a H₂SO₄ aq., the weight loss after immersion for the micro-crystallized AEB glass thick-film with the added MgO powder was reduced by approximately half compared with that of the AEB glass thick-film without the MgO powder. In addition, no cracks were observed on the film surface of the micro-crystallized AEB glass, whereas cracks appeared on the film surface of the non-crystallized AEB glass after the acid corrosion treatment. It is thought that micro-crystallization induced by the addition of MgO powder to the glass paste during the firing process is partly involved in improving the acid resistance of the AEB glass thick-film. During the peel adhesion test of the Ag conductor on the alumina substrate in a H₂SO₄ aq., the Ag conductor formed with the MgO powder-added AEB glass paste exhibited small deterioration of peel adhesion in comparison to the Ag conductor formed using the AEB glass paste without the MgO powder. These results suggest that the correlation between the improved acid durability and peel adhesion characteristics of the Ag conductor formed with the MgO powder-added AEB glass paste was related to the micro-crystallization of the AEB glass induced by the addition of MgO powder to the thick-film pastes during the annealing process at 850 °C.