Study On Preparation And Property Of CABS Glass + Fused Silica Multiphase Materials

In this paper, the primary aim was to prepare glass + ceramic materials used for LTCC (low temperature cofired ceramics) application and to study the materials'properties. In order to achieve low thermal expansion constant, we properly designed different compositions of the CaO-Al2O3-SiO2 (CAS) glass and prepared the glass by high temperature molten method. Fused silica was chose as the ceramic filler and was ball-milled for various hours. In this study, several methods such as DSC, XRD and SEM were used to study the materials'sintering property, phase composition, microstructure and so on.First, the phase transition of CAS glass and fused silica before and after sintering was studied. According to the result, amorphous CAS glass crystallized into anorthite and cristobalite after sintering, while fused silica still remained amorphous state. The thermal expansion constants of as-prepared glasses were near the designed value.Second, the sintering properties of CAS glass + fused silica were studied and the sintering mechanism was discussed. By changing the particle size of fused silica, its influence on the materials'sintering property was studied. The undesired cristobalite phase was reduced by changing the sintering schedule. The material achieved densification at 900℃by increasing the amount of CAS glass. CAS glass did not wet fused silica, viscous flow was the dominant mechanism in this material system.Last, the materials'thermal, dielectric and mechanical properties were studied. The thermal expansion constants were effectively reduced due to the absence of cristobalite. Low dielectric constant and dielectric loss were achieved at the same time. Bending strength was relatively low. This was mainly due to the great amount of closed pores in the material system.