High Breakdown Strength, High Dielectric Constant Composites for High Frequency Applications

Author(s):  
T. Bearpark ◽  
J. Davies ◽  
M. Dunleavy ◽  
H. Dyke ◽  
S. Haq ◽  
...  
2010 ◽  
Vol 2010 (1) ◽  
pp. 000521-000527
Author(s):  
Beihai Ma ◽  
Manoj Narayanan ◽  
U. (Balu) Balachandran

Ceramic film capacitors with high dielectric constant and high breakdown strength would result in advanced power electronic devices with higher performance, improved reliability, and enhanced volumetric and gravimetric efficiencies. We have grown ferroelectric films of lead lanthanum zirconate titanate (PLZT) on base metal foils by chemical solution deposition. Their dielectric properties were characterized over the temperature range between −50 and 150°C. We measured a dielectric constant of ≈700 and dielectric loss of ≈0.07 at −50°C and a dielectric constant of ≈2200 and dielectric loss of ≈0.06 at 150°C. At room temperature, we measured a leakage current density of ≈6.6 × 10−9 A/cm2, mean breakdown strength of 2.6 MV/cm, and energy density >85 J/cm3. A series of highly accelerated lifetime tests (HALT) was performed to determine the reliability of these PLZT film-on-foil capacitors under high temperature and high field stress conditions. Samples were exposed to temperatures ranging from 100 to 150°C and electric fields ranging from 8.7 × 105 V/cm to 1.3 × 106 V/cm during the HALT testing. Breakdown behavior of the samples was evaluated by Weibull analysis. The mean time to failure was projected to be >3000 h at 100°C with a dc electric field of ≈2.6 × 105 V/cm.


1999 ◽  
Vol 5 (S2) ◽  
pp. 612-613
Author(s):  
H-J. Gao ◽  
B. Rafferty ◽  
C.L. Chen ◽  
R.K. Singh ◽  
S.J. Pennycook

The trend of replacing trench and stack capacitors in a dynamic random access memory (DRAM) with a planar configuration has stimulated the development of high dielectric constant materials with reliably low leakage current and high dielectric breakdown strength. In this regard, high dielectric constant materials, such as PbZrxTiyO3(PZT), BaTiO3, SrTiO3, PbTiO3, and BaxSr1-xTiO3, have been extensively investigated as dielectrics in the last few decades. Of these, the sol id-solution quaternary BaxSr1-xTiO3, (BST) combines the high dielectric constant of BaTiO3, with the structural stability of SrTiO3, is one of the most promising materials for DRAM cells in very large-scale integrated circuits. BST shows a paraelectric phase for x<0.7 at room temperature, which provides additional features such as no aging or fatigue effects from ferroelectric domain switching. However, so far, there have been few studies of the interfaces between BST and the substrates, particularly at the atomic-resolution level.


2012 ◽  
Vol 557-559 ◽  
pp. 1869-1874 ◽  
Author(s):  
Takeshi Fukuda ◽  
Zhi Wei Luo ◽  
Aya Ito

Dielectric elastomer actuators with high dielectric constant and flexibility were prepared. These actuators were fabricated by the composite of barium titanate (BaTiO3) and polyester-type thermosetting polyurethane (TSU), which was molecularly-designed to become less hard segment content. In this study, the effects of particle size, volume fraction and manufacturing method of BaTiO3 were investigated. In addition, the mechanically-stretched effect in composites was also evaluated. It turned out that the electrical breakdown strength increased with the increase of particle size of BaTiO3 and in volume fraction as well as the use of BaTiO3 synthesized by the oxalate method. In addition, prestrain of composites also raised the electrical breakdown strength. However, the addition of BaTiO3 to polyurethane didn’t contribute to the actuation under a lower electric field.


2015 ◽  
Vol 814 ◽  
pp. 137-143
Author(s):  
Hao Zhou ◽  
Qing Meng Zhang ◽  
Qun Tang ◽  
Hang Cui ◽  
Yao Hua Xu ◽  
...  

The composites have a great use in practical application. In common, the phases in composite have different relative dielectric constant and in order to reveal how the phases with different permittivity affect the composite’s dielectric properties, the experiments were carried out using inorganic and organic composite with different dielectric constant phases to make that clear. The barium niobate-based SiO2system glass–ceramic and fillers-epoxy resin composites were chosen, and the dielectric properties were tested to compare the difference of those composites. The results show that the existence of high dielectric constant phases in composites can improve the permittivity of composites and make the composites present ferroelectric properties, while the dielectric loss can also increased, and the difference in dielectric constant of the phases can decrease the dielectric breakdown strength.


Sign in / Sign up

Export Citation Format

Share Document