Interaction between Alumina and Binary Glasses and Development of a Surface Treatment Method for AIN Substrates to lmprove Adhesion with Thick-Film Conductors

摘要

Interaction between 96 alumina and three binary glasses used as frits in thick-film technology is studied. A possible interfacial reaction mechanism where a melt glass penetrates into the alumina through the grain boundanes dissolving SiOz, one of the grain boundary components, is suggested. The formulation expressing the glass penetration rate into the alumina based on Poiseuille's law, assuming the driving force for ihe glass penetration is the capillary force, is consistent with the experimental growth rate of the reaction layer in the alumina. The formulation also clearly explains a relationship of the glass penetration degree to the viscosity and the surface tension of the melt glass. The extraordinary difference in K, designated as the coefficient of penetration, between the calculated result and the experimental result suggests that the process of dissolving SiO2 into a melt glass at the alumina grain boundaries retards the glass penetration. A surface treatment method for AIN substrates to improve adhesion with thick-film conductors is developed based on the above interfacial reaction mechanism between 96 alumina and glasses. The surface-treated AIN substrates aic prepared through oxidation and sol-gel processes. The oxidaiion atmosphere with high PO2 and low PH2O, which preduced the densest Al2O, layer on AIN is selected as the oxidation condiiion for the surface treatment. A SiO2 film layer was prepared on the Al2O, layer using the dipping technique with the sol-gel solution. The surface-treated AIN substrates with adequaie ihicknesses of AI2Oa and SiO2 as the s