Ceramics-Silikáty 66, (3) 310 - 324 (2022)

In this paper, the influence of the CaO content in glass on the sintering behaviour, structure, and properties of CaO-B₂O₃-Al₂O₃-SiO₂ glass/Al₂O₃ composites for low-temperature co-fired ceramic materials was studied. The results show that an increase in the CaO content in the glass reduces the polymerisation degree of the glass network, thereby reducing the glass viscosity and promoting the densification of the liquid phase sintering, increasing the crystallisation tendency of the material, reducing the crystallisation peak temperature and promoting the precipitation of anorthite in the material. The sintering activation energy of the glass/Al₂O₃ first decreases and then increases, and reached a minimum in C4. The anorthite can reduce the bulk density and coefficient of the thermal expansion of the materials, and an appropriate amount of anorthite can improve the flexural strength of the material by more than 190 MPa. When the CaO content in the glass increases, the required sintering temperature for the material to achieve the maximum flexural strength is lower. The sample (C4-850) with a CaO content of 27.60 %, achieving densification when sintered at 850 °C for 1 h, showed a flexural strength of 190.1 MPa and a coefficient of thermal expansion of 6.083× 10^-6 K^-1, which is suitable for substrate packaging.