Microstructure, sintering and properties of CaO–Al2O3–B2O3–SiO2 glass/Al2O3 composites with different CaO contents

Abstract

CaO-Al 2 O 3 -B 2 O 3 -SiO 2 glass/Al 2 O 3 composites for low temperature co-fired ceramics (LTCC) were prepared by tape casting method, and the effects of CaO content on the microstructure, sintering, and properties were discussed. Results showed that an appropriate CaO addition in CABS glass not only efficiently contributed to a dense glass/ceramic body, but also was endowed with better sintering characteristics, more excellent mechanical and dielectric properties. CABS glass/Al 2 O 3 composites with 9 wt% CaO content sintered at 850°C for 15 min exhibited bulk density of 3.10 g/cm 3 , Z-axis shrinkage of 15.3 %, flexural strength of 185 MPa, dielectric constant of 7.99 (at 7 GHz), dielectric loss of 1.8 9 10 -3 . After being co-fired with Ag electrodes, the glass/ceramic composites could perfectly match with Ag electrodes. It is indicated that this material could be a promising candidate for LTCC application.

Microwave dielectric properties of SnO‐SnF2‐P2O5 glass and its composite with alumina for ULTCC applications

“…The traditional method to lower the sintering temperature of the Al 2 O 3 is by glass addition. Several authors reported the effective role of glass in reducing the sintering temperature of Al 2 O 3 …”

The tape casting process for manufacturing low‐temperature co‐fired ceramic green sheets: A review

“…The powders settled under the action of gravity forming porous solid bridges in the green sheets . Although fine powder is detrimental to the relative density of the green sheet, it possesses a higher surface energy, which provides a greater driving force for densification …”

“…For example, pure ethyl acetate dries quickly, allowing for good production efficiency, but premature drying creates a skin over the green sheet. This skin can induce streaks or even cracks under the doctor blade . Streicher et al and Gutiérrez et al noted that the evaporation rate of the solvent was the main cause of tape cracking.…”

Carbon nanotube/graphene oxide‐added CaO‐B2O3‐SiO2 glass/Al2O3 composite as substrate for chip‐type supercapacitor

“…For example, Murata SWG shows a large bending strength, but its thermal conductivity is poor . CaO‐BaO‐Al 2 O 3 ‐B 2 O 3 ‐SiO 2 /AlN and Li 2 O‐SiO 2 ‐ZrO 2 /Al 2 O 3 glass/ceramic composites exhibit high thermal conductivity, but their mechanical strength is low . Therefore, it is necessary to develop new types of glass/ceramic composites that have both high mechanical strength and good thermal conductivity.…”