• Journal of Powder Materials
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• v.18 no.5
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• pp.423-429
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• 2011

Thermoelectric-thick films were fabricated by using a screen printing process of n and p-type bismuth-telluride-based pastes. The screen-printed thick films have approximately 30 ${\mu}m$ in thickness and show rough surfaces yielding an empty gap between an electrode and the thick film. The gap might result in an increase of an electrical resistivity of the fabricated thick-film-type thermoelectric module. In this study, we suggest a conductive metal coating onto the surfaces of the screen-printed paste in order to reduce the contact resistance in the module. As a result, the electrical resistivity of the thermoelectric module having a gold coating layer was significantly reduced up to 30% compared to that of a module without any metal coating. This result indicates that an introduction of conductive metal layers is effective to decrease the contact resistivity of a thick-film-typed thermoelectric module processed by screen printing.

• Journal of the Korean Ceramic Society
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• v.51 no.4
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• pp.344-349
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• 2014

$RuO_2$-based high frequency thick-film resistor paste was printed at the speed of 10, 100, 300 mm/sec on the AlN substrate, and then sintered at between 750 and $900^{\circ}C$. The sintered thick films were characterized in terms of printing and sintering conditions. With increasing printing speed, the thickness and roughness of sintered film increased. The resistance of the thick film resistor was reduced by increasing the printing speed from 10 to 100 mm/sec, but did not significantly change at 300 mm/sec speed. With increasing sintering temperature, the surface roughness and thickness of sintered resistor film decreased. The reduction rate was large in case of fast printed resistor. The resistance of the resistor increased up to $800^{\circ}C$ with sintering temperature, but again decreased at the higher sintering temperature.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.11
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• pp.921-925
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• 2000

Characteristics of Pb(Mg, Nb)O$_3$-Pb(Zr, Ti)O$_3$system thick films fabricated by a screen printing method were investigated. The buffer layer were coated with various thickness of Ag-Pd by screen printing to investigate the effect as a diffusion barrier and deposited Pt as a electrode by sputtering on Ag-Pb layer. The printed thick films were burned out at 650$\^{C}$ and sintered at 950$\^{C}$ in O$_2$condition for each 20, 60min after printing with 350mesh screen. The thickness of piezoelectric thick film was 15∼20㎛ and Ag-Pb layer acted as a diffusion barrier above 3㎛ thickness. The PMN-PZT thick films were screen printed on Pt/Ag-Pb(6m) and sintered by 2nd step (650$\^{C}$/20min and 950$\^{C}$/1h) using paste mixed PMN-PZT and binder in the ratio of 70:30, and the remnant polarization of thick film was 9.1$\mu$C/㎠ in this conditions.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.4
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• pp.83-89
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• 2015

In this paper, we propose a fabrication technique for enhanced electrical properties of piezoelectric thick films with excellent patterning property using sol-infiltration and a direct-patterning process. To achieve the needs of high-density and direct-patterning at a low sintering temperature (< $850^{\circ}C$), a photosensitive lead zirconate titanate (PZT) solution was infiltrated into a screen-printed thick film. The direct-patterned PZT films were clearly formed on a locally screen-printed thick film, using a photomask and UV light. Because UV light is scattered in the screen-printed thick film of a porous powder-based structure, there are needs to optimize the photosensitive PZT sol infiltration process for obtaining the enhanced properties of PZT thick film. By optimizing the concentration of the photosensitive PZT sol, UV irradiation time, and solvent developing time, the hybrid films prepared with 0.35 M of PZT sol, 4 min of UV irradiation and 15 sec solvent developing time, showed a very dense with a large grain size at a low sintering temperature of $800^{\circ}C$. It also illustrated enhanced electrical properties (remnant polarization, $P_r$, and coercive field, $E_c$). The $P_r$ value was over four times higher than those of the screen-printed films. These films integrated on silicon wafer substrate could give a potential of applications in micro-sensors and -actuators.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.12
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• pp.987-993
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• 2001

In this paper, we presents the construction details and output characteristics of a thick film piezoresistive strain gage. The thick film was printed on the ceramic diaphragm back side by screen printing and cured at 850$^{\circ}C$. The strain distribution and deflection on ceramic diaphragm were performed with finite-element method(FEM tool ANSYS-5.3). Various thick film strain gage characteristics were analysed, including nonlinearity, hysteresis, stability and sensitivity of thick film strain gages.

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.21.2-21.2
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• 2007

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.474-477
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• 2002

We performed a continuous heat treatment experiment for long Si$_2$Sr$_2$CaCuO$_{x}$ (Bi2212) superconductor tapes on copper substrates. A precursor that contains a mixture of Bi$_2$O$_3$, SrCO$_3$, and CaCO$_3$ powders was prepared and screen-printed on Cu tapes. The screen- printed tapes were thermally treated by consecutive processes with various temperature settings using an air-filled tube furnace. The diffraction patterns and the microstructures of the high temperature superconductor thick films were analyzed by X-ray diffractometry (XRD) and optical Microscopy respectively, and the critical temperatures of the superconducting thick films were measured. The critical temperatures of the superconducting films were measured to be about 77K, and the films'crystallographic c-axes were confirmed to be normal to the film surfaces by XRD and morphology observation. We also observed that the thick superconducting layer is formed and aligned on the copper substrate via partial melted state that consists of a liquid phase and a secondary phase.e.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2209-2210
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• 2006

In this paper, PZT(20/80) thick films were fabricated by the screen-printing method. And the PZT(80/20) coating solution was synthesized by the sol-gel method. PZT(20/80) thick films were screen-printed on the alumina substrates. PZT(80/20) thin film was spin-coaled on the PZT(20/80) thick films to obtain densification. And the structural and electrical properties of PZT thick films were investigated with variation of sintering temperature. The PZT specimen sintered at $650^{\circ}C$ showed good relative dielectric constant of 219 and dielectric loss of 2.45%. Also the remanent polarization and the coercive field wore 16.48 ${\mu}C/cm^2$ and 35.48kV/cm, respectively.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.577-578
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• 2006

In this paper, PZT(20/80) thick films were fabricated by the screen-printing method. And the PZT(80/20) coating solution was synthesized by the sol-gel method. PZT(20/80) thick films were screen-printed on the alumina substrates. PZT(80/20) thin film was spin-coated on the PZT(20/80) thick films to obtain densification. And the structural and electrical properties of PZT thick films were investigated with variation of sintering temperature. The PZT specimen sintered at 650f showed good relative dielectric constant of 219 and dielectric loss of 2.45%. Also the remanent polarization and the coercive field were 16.48${\mu}C/cm^2$ and 35.48kV/cm, respectively.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1243-1244
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• 2006

In this paper, PZT(20/80) thick films were fabricated by the screen-printing method. And the PZT(80/20) coating solution was synthesized by the sol-gel method. PZT(20/80) thick films were screen-printed on the alumina substrates. PZT(80/20) thin film was spin-coated on the PZT(20/80) thick films to obtain densification. And the structural and electrical properties of PZT thick films were investigated with variation of sintering temperature. The PZT specimen sintered at $650^{\circ}C$ showed good relative dielectric constant of 219 and dielectric loss of 2.45%. Also the remanent polarization and the coercive field were $16.48{\mu}C/cm^2$ and 35.48kV/cm, respectively.