The effect of firing temperature and firing time on the phase composition, microstructure, biaxial flexural strength, and temperature coefficient of expansion (TCE) of the popular lowtemperature Cofired ceramic (LTCC) material was presented. In the studied materiali which is a composite of lead borosilicate glass and alumina particles at temperatures around 700°C the Al2O3 starts to dissolve in a low viscosity glass phase and this takes place up to 800°C, when 10 wt% of Al2O3 ceramic filler is dissolved in the glass phase forming the aluminaenriched area. This area is suitable for the crystallization of anorthite, which nucleates on the Al2O3 particles. The crystallization starts at 875°C and the mass fraction of anorthite increases with increasing temperature until it reaches a plateau value of around 22 wt% at higher temperatures or longer firing times. The major effect on the biaxial flexural strength of LTCC is that of porosity. The effect of the amount of anorthite on the LTCC biaxial flexural strength is minor. The TCE is correlated with the anorthite mass fraction, which crystallizes at the expense of a decreasing amount of glass phase in the LTCC.
COBISS.SI-ID: 26548263
In this work the effect of firing temperature and firing time on the phase composition, microstructure, biaxial flexural strength and temperature coefficient of expansion (TCE) of LTCC material is presented. At temperatures around 700 °C the Al2O3 starts to dissolve in low viscous glass phase and it takes place up to 800 °C when 10 w.% of Al2O3 ceramic filler is dissolved in the glass phase forming the alumina enrich area. This area is suitable for crystallization of anorthite which nucleates on the Al2O3 particles. The crystallization starts at 875 °C and the mass fraction of anorthite is increasing with increasing temperature until it reaches the plateau value of around 22 w.% at higher temperatures or longer firing times. The biaxial flexural strength of LTCC increases with increasing firing temperature from 135 MPa (at 800 °C) to around 300 MPa (at 900 °C). The major effect on the biaxial flexural strength of LTCC has porosity. The effect of the amount of the anorthite on the LTCC biaxial flexural strength is miner. The TCE of the LTCC decreases from 5.6 × 10-6 to 5.0 × 10-6 K-1 with increasing firing temperatures or times and it is correlated with the anorthite mass fraction which crystalize at the expense of a decreasing amount of glass phase in the LTCC.
COBISS.SI-ID: 25443367
In this article the investigation thick-film resistors fired on different LTCC substrates were presented. Special attention was paid on the compatibility of thick-film materials and LTCC materials, and piezoresistance property of the resistors.
COBISS.SI-ID: 25943847
In this article we present the results of an investigation of the long-term stability of piezoresistive LTCC-based pressure sensors with the main emphasis on the effects of accelerated ageing. Noise spectroscopy was considered as a possible method for predicting the stability of the sensors’ characteristics.
COBISS.SI-ID: 26799911