Properties of borosilicate glass/Al2O3 composites with different Al2O3 concentrations for LTCC
applications
This article aims to investigate the effect of Al2O3 in borosilicate glass on the sintering densification
and properties of the borosilicate glass/Al2O3 LTCC composites. A series of CaO–Al2O3–B2O3–SiO2
(CABS) glass with different concentrations of Al2O3 was synthesized, as well as the CABS
glass/Al2O3 LTCC composites. The influence of Al2O3 on the sintering densification, phase
composition, microstructures and properties of the CABS glass/Al2O3 LTCC composites was then
systematically investigated. Result indicates that a proper amount of Al2O3 in CABS glass not only
can strengthen the structural stability of the borosilicate glass, but also can promote the sintering
densification and improve the properties of the glass/ceramic composites. CABS glass/Al2O3
composites prepared with CABS glass of 4 wt.% Al2O3 sintered at 875 °C exhibits excellent
properties of a sintering density of 3.13 g/cm3, a Z axial shrinkage of 15.5%, a dielectric constant
(εr) of 8.08, a dielectric loss (tanδ) of 0.9 × 10–3 (at 7 GHz), a coefficient of thermal expansion (CTE)
of 5.35 ppm/°C, a flexural strength of 206 MPa, demonstrating its great potential for LTCC
applications.
Al2O3-Based Ceramic Materials for LTCC Technology: An Overview
Published: 26 April 2023
Volume 79, pages 497–501, (2023)
Cite this article
The difficulties of obtaining high-temperature (HTCC) and low-temperature (LTCC) ceramics and the
transition from the high-temperature process of obtaining ceramic materials to the lowtemperature process are discussed. Atypical process for obtaining LTCC as well as the characteristics
and properties of a classic glass-ceramic composite are described. The basic applications of glassceramic obtained by LTCC technology are shown.
Synthesis and characteristics of borosilicate-based glass–ceramics with different SiO2 and Na2O
contents
Author links open overlay panel Luchao Ren, Hongqing Zhou, Xia Li, Wentao Xie, Xianfu Luo
Abstract
Our present work was initiated with the aim of optimizing the borosilicate-based glass–ceramics
composites by adjusting SiO2 and Na2O composition in CaO–Al2O3–B2O3–SiO2 (CABS) glass
slightly. To illustrate the functional mechanism of glass network former (SiO2) and the glass network
amender (Na2O), we focused on the multiple performances of the composites by employing
different qualitative and quantitative instruments. Results showed that decreasing SiO2 content or
increasing Na2O content appropriately both could promote sintering densification, accelerate the
formation of anorthite phases and lower the dielectric loss. CABS glass/Al2O3 composite with 54
wt% SiO2 content and 1 wt% Na2O content being sintered at 850 °C for 15 min exhibited the best
properties. In addition, after co-firing with Ag electrodes, glass/Al2O3 composite could meet the
shrinkage requirement of Ag electrodes and could not possibly react with Ag electrodes at 850 °C.
Based on the above findings, the borosilicate-based glass/Al2O3 composites we have studied can be
suitable for LTCC application.