Cordierite is a promising low-k material in mi cr oelectronic and packaging industries. When it is co-fired with the metal for re alising the multilayer circuits, temperature should be low enough to prevent the meltin...Cordierite is a promising low-k material in mi cr oelectronic and packaging industries. When it is co-fired with the metal for re alising the multilayer circuits, temperature should be low enough to prevent the melting and/or oxidising of the metal. However, this temperature is usually too low to sinter cordierite. Low melting point glass, therefore, is added to the s toichiometric cordierite to lower the sintering temperature through a liquid-si ntering process. In this research work, cordierite-based glass ceramics tapes were prepared by t ape casting from suspensions containing different solids loading and different m ean particle sizes. The optimal experimental conditions for obtaining homogenous green tapes were determined by varying the type and concentration of dispersant s and binders, the solids loading as well as the particle sizes of both cordieri te and glass. Scanning electron microscopy (SEM) and Hg porosimetry were used to characterise the green tapes. The results showed that high values of solids vol ume fractions and of the size ratio between the mean particle sizes of glass and cordierite powders favour the obtaining of homogeneous and high dense substrate s. The dielectric constant of the sintered bodies at 1 100 ℃ was around 5 and t he dissipation factor was about 0.01 at 1 MHz.展开更多
Cordierite-based glass-ceramics with non-stoichiometric composition doped with rare earth oxide (REO_2) and heavy metal oxide (M_2O_3) respectively were fabricated from glass powders. After sintering and crystallizati...Cordierite-based glass-ceramics with non-stoichiometric composition doped with rare earth oxide (REO_2) and heavy metal oxide (M_2O_3) respectively were fabricated from glass powders. After sintering and crystallization heat treatment, various physical properties, including compact density and apparent porosity, were examined to evaluate the sintering behavior of cordierite-based glass-ceramics. Results show that the additives both heavy metal oxide and rare earth oxide promote the sintering and lower the phase temperature from μ- to α-cordierite as well as affect the dielectric properties of sintered glass-ceramics. The complete-densification temperature for samples is as low as 900 ℃. The materials have a low dielectric constant (≈5), a low thermal expansion coefficient ((2.80～3.52)×10^(-6) ℃^(-1)) and a low dissipation factor (≤0.2%) and can be co-fired with high conductivity metals such as Au, Cu, Ag/Pd paste at low temperature (below 950 ℃), which makes it to be a promising material for low-temperature co-fired ceramic substrates.展开更多
文摘Cordierite is a promising low-k material in mi cr oelectronic and packaging industries. When it is co-fired with the metal for re alising the multilayer circuits, temperature should be low enough to prevent the melting and/or oxidising of the metal. However, this temperature is usually too low to sinter cordierite. Low melting point glass, therefore, is added to the s toichiometric cordierite to lower the sintering temperature through a liquid-si ntering process. In this research work, cordierite-based glass ceramics tapes were prepared by t ape casting from suspensions containing different solids loading and different m ean particle sizes. The optimal experimental conditions for obtaining homogenous green tapes were determined by varying the type and concentration of dispersant s and binders, the solids loading as well as the particle sizes of both cordieri te and glass. Scanning electron microscopy (SEM) and Hg porosimetry were used to characterise the green tapes. The results showed that high values of solids vol ume fractions and of the size ratio between the mean particle sizes of glass and cordierite powders favour the obtaining of homogeneous and high dense substrate s. The dielectric constant of the sintered bodies at 1 100 ℃ was around 5 and t he dissipation factor was about 0.01 at 1 MHz.
文摘Cordierite-based glass-ceramics with non-stoichiometric composition doped with rare earth oxide (REO_2) and heavy metal oxide (M_2O_3) respectively were fabricated from glass powders. After sintering and crystallization heat treatment, various physical properties, including compact density and apparent porosity, were examined to evaluate the sintering behavior of cordierite-based glass-ceramics. Results show that the additives both heavy metal oxide and rare earth oxide promote the sintering and lower the phase temperature from μ- to α-cordierite as well as affect the dielectric properties of sintered glass-ceramics. The complete-densification temperature for samples is as low as 900 ℃. The materials have a low dielectric constant (≈5), a low thermal expansion coefficient ((2.80～3.52)×10^(-6) ℃^(-1)) and a low dissipation factor (≤0.2%) and can be co-fired with high conductivity metals such as Au, Cu, Ag/Pd paste at low temperature (below 950 ℃), which makes it to be a promising material for low-temperature co-fired ceramic substrates.
