• Transactions on Electrical and Electronic Materials
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• v.10 no.4
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• pp.121-124
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• 2009

In this study, in order to develop compositions of ceramics suitable for piezoelectric actuator and ultrasonic vibrator applications using low temperature sintering, multilayer, PMN-PNN-PZT ceramics were fabricated using $Li_2CO_3$ and $Na_2CO_3$ as sintering aids. Their structural, piezoelectric and dielectric characteristics were investigated according to the Zr/Ti ratio. As the Zr/Ti ratio increased, the electromechanical coupling factor $k_p$, and piezoelectric constant $d_{33}$ and the mechanical quality factor $Q_m$ all increased with Zr/Ti ratio and then decreased after the ratio exceeded 50/50. At the ratio of Zr/Ti =49/51 and sintering temperature of $900^{\circ}C$; the density, electromechanical coupling factor $k_p$, dielectric constant ${\varepsilon}_r$ piezoelectric $d_{33}$ constant and mechanical quality factor $Q_m$ all showed the optimum values of 7.900 $g/cm^3$, 0.576, 856, 312 pC/N, 1,326, respectively. These property values are very suitable for multilayer ceramics actuator applications.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.367-370
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• 2007

An EEFL with the sodium free alumino-silicate glass of high K and low $tan{\delta}$, has been investigated. As compared with borosilicate and the soda-lime EEFLs, the luminous efficiency as well as the pinhole stability of new EEFLs improves remarkably without blackening of $NaHg_2$.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2000.04a
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• pp.87-96
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• 2000

The properties of polyimide for interlayer dielectric applications are investigated during plasma etching of aluminum on it. Chlorine-based plasma generally used for aluminum etching results in an increase in the (dielectric constant of polyimide, while $SF_6$ plasma exhibits a high polyimide etch rate and a reducing effect of the dielectric constant. The leakage current of polyimide is significantly suppressed after plasma exposure. An optimal combination of Al etch with $Cl_6$ plasma and polyimide etch with $SF_6$ plasma is expected to be a good tool for realizing multilevel metallization structures.

• Journal of the Korean Ceramic Society
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• v.30 no.8
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• pp.671-677
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• 1993

Effects of PbTiO3 addition on dielectric properties and extent of PbO loss in Nd-doped Pb(Mg1/3Nb2/3)O3 system were investigated. As the proportion of dopping increased, the phase transition temperature shifted to low region, and the dielectric constant at room temperature decreased rapidly. But as the proportion of PbTiO3 increased, the phase transition temperature shifted to high retion, and the dielectric constant at room temperature increased. The substitution of Nd3+ for Pb2+ decreased the amount of PbO evaporation, therefore the sample sintered well in case of only 1 mole% adding excess PbO.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.12a
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• pp.130-135
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• 2003

Low dielectric constant SiOC(-H) films have been prepared by inductively coupled plasma chemical vapor deposition using bis-trymethylsilyl-methane (BTMSM) and $O_2$ precursors. The annealing effects on the structural and electrical properties were studied. The results indicate post-annealing could efficiently remove the hydroxyl (-OH) related groups from the as-deposited films and cause the chemical structure re-arrangement, resulting in the more nano-pores being formed in the annealed SiOC(-H) films. The dielectric constant decreased from 2.7 to 2.1, and the refractive index decreased from 1.427 to 1.32.

• The Korean Journal of Ceramics
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• v.2 no.2
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• pp.111-113
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• 1996

Dielectric properties at microwave frequency region of the five-layered compound $Ba_5Nb_4O_{15}$ prepared by the conventional solid state reaction method were investigated. $Ba_5Nb_4O_{15}$ has excellent microwave dielectric characteristics; ${\varepsilon}_r$=38, Q=7500 at 10 GHz, and ${\tau}_l$=+50 ppm/K. Since this compound has a high dielectric constant, high Q and sufficiently stable characteristics, it is useful for the applications at microwave frequencies.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.11
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• pp.1484-1491
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• 2020

Since the slot line transmits electric and magnetic signals through the slot, the size of the slot greatly affects the signal power loss. In order to have low loss, the slot line is mainly used at a high frequency of above 3GHz on a substrate having a high dielectric constant(er). This paper proposes the 4:1 impedance transformer using a slot line on TLC-30 laminate (h=20mil, er=3.0; Taconic) being a relatively low dielectric constant at a frequency of 1.85GHz. In the proposed impedance transformer, the dielectric resonator is arranged on the slot line to reduce signal loss occurring at the slot line. The proposed 4:1 microstrip-slot line impedance transformer fabricated using a (Zr,Sn)TiO4 dielectric resonator(er=38) has the transmission loss(S21) of -0.375dB and the reflection value(S11) of -27.6dB at 1.855GHz. This confirms that the slot line can be stably used even in a low dielectric constant substrate and a low frequency region by using a dielectric resonator.

• Proceedings of the Korean Vacuum Society Conference
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• 2007.08a
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• pp.57-57
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• 2007

• Journal of electromagnetic engineering and science
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• v.6 no.1
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• pp.1-9
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• 2006

A sandwich structure of dielectric material and air gap inside a rectangular waveguide is proposed as a fast electrically tunable low-loss phase shifter. As the dielectric material is shifted up and down by piezoelectric actuator and, thereby, the thickness of air gap is changed, the effective dielectric constant of the sandwich structure is varied. Phase shifters based on the sandwich structure with different dielectric materials showed phase shift of $20{\sim}200^{\circ}/cm$ at X-band as the thickness of air gap varied up to $30{\mu}m$. The idea can be extended toward low-loss millimeter wave phase shifters since modem microwave ceramics have been developed to show very low dielectric loss$(tan\;{\delta}{\sim}10^{-4})$.

• Journal of the Microelectronics and Packaging Society
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• v.6 no.1
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• pp.75-79
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• 1999

We have studied electrical properties of polyimide for the next generation interlayer low dielectric during plasma etching. Dielectric constant of polyimide exposed to Cl-based plasma, which is used in aluminum etching, increased, while that of polyimide exposed to $SF_{6}$ plasma decreased. The results are related to fluorine or chlorine bonds as examined by FTIR ana XPS analyses. So, we expect that Cl-based 1)miasma etching of aluminum followed by $SF_{6}$ plasma exposure results in the prevention of post-etch corrosion and decrease of dielectric constant.