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

Abstract

Ultralow‐temperature sinterable alumina‐45SnF2:25SnO:30P2O5 glass (Al2O3‐SSP glass) composite has been developed for microelectronic applications. The 45SnF2:25SnO:30P2O5 glass prepared by melt quenching from 450°C has a low Tg of about 93°C. The SSP glass has εr and tanδ of 20 and 0.007, respectively, at 1 MHz. In the microwave frequency range, it has εr=16 and Qu × f=990 GHz with τf=−290 ppm/°C at 6.2 GHz with coefficient of thermal expansion (CTE) value of 17.8 ppm/°C. A 30 wt.% Al2O3‐70 wt.% SSP composite was prepared by sintering at different temperatures from 150°C to 400°C. The crystalline phases and dielectric properties vary with sintering temperature. The alumina‐SSP composite sintered at 200°C has εr=5.41 with a tanδ of 0.01 (1 MHz) and at microwave frequencies it has εr=5.20 at 11 GHz with Qu × f=5500 GHz with temperature coefficient of resonant frequency (τf)=−18 ppm/°C. The CTE and room‐temperature thermal conductivity of the composite sintered at 200°C are 8.7 ppm/°C and 0.47 W/m/K, respectively. The new composite has a low sintering temperature and is a possible candidate for ultralow‐temperature cofired ceramics applications.

Continuously tunable broadband emission of Mn2+‐doped low‐melting point Sn–F–P–O glasses for warm white light‐emitting diodes

“…The linear CTE was determined to be 21.9 ppm/°C, which is close to those reported in the literature. 16 Meanwhile, the Tg value obtained for the TFP glass from CTE measurement is~122°C and agrees with that derived from differential scanning calorimeter (DSC) analysis in our previous research. 12 Although a small amount of MnO is introduced into the glass, it does not change the Tg of these glasses ( Figure 1B).…”

“…where dL/L 0 is the thermal expansion length and ΔT is the difference between room temperature and measurement temperature, respectively. The linear CTE was determined to be 21.9 ppm/°C, which is close to those reported in the literature . Meanwhile, the Tg value obtained for the TFP glass from CTE measurement is ~122°C and agrees with that derived from differential scanning calorimeter (DSC) analysis in our previous research .…”

Recent Progress in Applications of the Cold Sintering Process for Ceramic–Polymer Composites

“…The liquid phase aids diffusional processes through nonequilibrium dissolution and precipitation reactions at the ceramic solid–liquid interface. There are also active groups from Asia and Europe who have also succeeded in the cold sintering densification of Al 2 SiO 5 ‐NaCl, Al 2 O 3 ‐NaCl, CaCO 3 , and Na 0.5 Bi 0.5 MoO 4 ‐Li 2 MoO 4 ceramics using cold sintering process in the temperature range of room temperature to 300 °C. More recently, the Luo and Guillon groups have reported that ZnO can be densified using electric field assisted cold sintering.…”

Study on structure, microstructure and microwave dielectric characteristics of CaV2O6 and (Ca0.95M0.05)V2O6 (M=Zn, Ba) ceramics

“…Moreover, the most significant current tendency in LTCC technology is to develop new ceramics with sintering temperature lower than 660°C (the melting point of Al electrode), leading to the introduction of a new class of materials known as ultra‐low temperature co‐fired ceramics (ULTCC). Quite recently, great attention has been paid to ULTCC technology due to its excellent features such as energy saving, environmental benefits, cost reduction …”

“…Quite recently, great attention has been paid to ULTCC technology due to its excellent features such as energy saving, environmental benefits, cost reduction. [9][10][11] A considerable amount of literature has been published based on ceramics with good microwave dielectric properties, however, a major problem with this kind of ceramics is their high sintering temperature. 12 A number of researchers have sought to lower the sintering temperature of ceramics using low-melting constituent, including TeO 2 , B 2 O 3 , Bi 2 O 3 , V 2 O 5 , Li 2 O, MoO 3 , etc.…”