Dielectric Properties of LTCC System of Al₂O₃ and Borosilicate Glass

Abstract

In this paper, three types of Al2O3 powders with different sizes (1.6μm, 0.7μm, and 0.3μm) were used in a LTCC system of Al2O3 and borosilicate glass (BSG). Al2O3 and BSG are selected on account of their coefficient of thermal expansion (CTE) similar to silicon, which can reduce thermal stress. It was found that the dielectric constant, ε, of substrates drops with the decrease of Al2O3 powder size. ε increases with the increase of Al2O3 content for the sample with 1.6 μm Al2O3 powder, but decreases with the increase of Al2O3 content for the samples with 0.7 μm and 0.3 μm Al2O3 powders. SEM observations revealed that more pores with low permittivity appeared for the samples with smaller Al2O3 powders, resulting in the drop of dielectric constant of the sample finally.

Crystal structure of the OH-dominant gadolinite-(Y) analogue (Y,Ca)2(Fe,□)Be2Si2O8(OH,O)2 from Heftetjern pegmatite, Norway

“…Gadolinite-datolite-type compounds attract interest because of their physical and chemical properties. They are considered as potential optical materials (Verstegen et al, 1972;Wang et al, 2009;Juwhari & White, 2012;Peng et al, 2016), materials for electrical engineering (Konerskaya et al, 1988;Tummala, 1991;Podlesov et al, 1992;Jean et al, 2002;Liu et al, 2007;Chiang et al, 2008), membrane technology (Farsiyants et al, 1989;Schubert, 2003), protection from neutron radiation (Tarasevich et al, 1990;Mann & Sidhu, 2012) and as a matrix for the immobilization of nuclear wastes (Ojovan & Lee, 2005;Malczewski & Dziurowicz, 2015). In geological sciences, gadolinite group minerals are used as a geochemical marker of magmatic as well as low-temperature processes (Bellatrecia et al, 2006;Zaccarini et al, 2008;Lyalina et al, 2014;Karas' & Ratkin, 2014).…”