• Title/Summary/Keyword: Electronic and thermal properties

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A Study on the Thermal and Chemical Properties of Carbon Nanotube Reinforced Nanocomposite in Power Cables

  • Yang, Sang-Hyun;Jang, Hyeok-Jin;Park, Noh-Joon;Park, Dae-Hee;Yang, Hoon;Bang, Jeong-Hwan
    • Transactions on Electrical and Electronic Materials
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    • v.10 no.6
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    • pp.217-221
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    • 2009
  • The use of the carbon nanotube (CNT) is superior to the general powder state materials in their thermal and chemical properties. Because its ratio of diameter to length (aspect ratio) is very large, it is known to be a type of ideal nano-reinforcement material. Based on this advantage, the existing carbon black of the semiconductive shield materials used in power cables can acquire excellent properties by the use of a small amount of CNTs. Therefore, we fabricated specimens using a solution mixing method. We investigated the thermal properties of the CNT, such as its storage modulus, loss modulus, and its tan delta using a dynamic mechanical analysis 2980. We found that a high thermal resistance level is demonstrated by using a small amount of CNTs. We also investigated the chemical properties of the CNT, such as the oxidation reaction by using Fourier transform infrared spectroscopy (FT-IR) made by Travel IR. In the case of the FT-IR tests, we searched for some degree of oxidation by detecting the carboxyl group (C=O). The results confirm a tendency for a high cross-linking density in a new network in which the CNTs situated between the carbon black constituent molecules show a bond using similar constructive properties.

Thermal and Structural Properties of Elastic Epoxy According to Content Changes of Elastomer (엘라스토머 함량 변화에 아른 탄성에폭시의 열적, 구조적 특성)

  • Min, J.Y.;Lee, K.Y.;Lee, K.W.;Choi, Y.S.;Park, D.H.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.461-464
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    • 2004
  • In this paper, the elastic epoxy added elastomer having viscoelasticity to existing epoxy was measured thermal, structural properties through TGA(Thermogravimetric Analysis) and FESEM(Field Emission Scanning Electron Microscope). Specimens were made of dumbbell forms by the ratio of 5[phr], 10[phr], 15[phr], and 20[phr] by regulation with elastomer contents. The measurement temperature dimensions of TGA were $0[^{\circ}C]\;to\;800[^{\circ}C]$, and rising temperature was $5[^{\circ}C/min]$. And we observed structure through FESEM at the magnification of 1000times with the voltage of 15[kV] after breaking by quenching specimens. As thermal analysis results, we could know that thermal and structural properties was improved quantity according to decrease of elastomer contents. In general, thermal, structural properties of 15[phr] was excellent among the specimens.

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The Effect of Crystallographic and Optical Properties Under Rapid Thermal Annealing Conditions on Amorphous Ga2O3 Deposited Using RF Sputtering System (RF 스퍼터링 시스템을 이용하여 증착한 비정질 Ga2O3 박막의 급속 열처리 조건에 따른 결정성과 광학적 특성 변화)

  • Hyungmin Kim;Sangbin Park;Jeongsoo Hong;Kyunghwan Kim
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.36 no.6
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    • pp.576-581
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    • 2023
  • The Ga2O3 thin films were deposited using an RF sputtering system and the effect of crystallographic and optical properties under rapid thermal annealing conditions on Ga2O3 thin film was evaluated. A rapid thermal annealing method can fabricate a crystalline Ga2O3 thin film which is applied to various fields with a low cost and a high efficiency compared with the conventional post-annealing method. In this study, the Ga2O3 treated at 900℃ for 1 min showed the beta and gamma phases in XRD measurement. In optical properties, the crystalline Ga2O3 represented a high transmittance of more than 80% in the visible region and was calculated with a high optical bandgap energy of 4.58 eV. The beta and gamma phases Ga2O3 can be obtained by adjusting the rapid thermal annealing temperatures, and the various properties such as the optical bandgap energy can be controlled. Moreover, it is expected that crystalline Ga2O3 can be applied to various devices by controlling not only temperature but process time.

Effect of Dry Process on Dielectric Properties of PZT Thin Films Prepared by Sol-Gel Process

  • Bae, Min-Ho;Lim, Kee-Joe;Kim, Hyun-Hoo;No, Kwang-soo
    • Transactions on Electrical and Electronic Materials
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    • v.3 no.1
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    • pp.42-45
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    • 2002
  • Properties of lead zirconate titanate ferroelectric thin films prepared by rapid thermal annealing/direct insertion thermal annealing were investigated. The remnant polarization (Pr), saturation polarization (Ps), and coercive force (Ec) of typical samples annealed by rapid thermal annealing (RTA) are about 13.7 $\mu$ C/cm$^2$, 27.1 $\mu$C/cm$^2$, and 55.6 kV/cm, respectively. The dielectric constant of the sample is about 786, the dielectric loss tangent is about 2.4% at 1 kHz. Furthermore, ferroelectric, conduction, and piezoelectric properties of the thin films annealed by RTA process and the direct insertion thermal annealing (DITA) process were compared. The influence of temperature in the dry process on the above properties was also investigated.

Dielectric Relaxation Properties for following the Ageing of Polyetheretherketone (열화에 따른 Polyetheretherketone의 유전완화특성)

  • Kim, Ki-Yup;Lee, Chung;Ryu, Boo-Hyung;Lim, Kee-Joe
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.4
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    • pp.396-403
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    • 2004
  • The dielectric properties of Y-ray irradiated and thermally aged polyetheretherketone (PEEK) have been investigated. Results of the temperature dependency of dielectric properties indicated that the glass transition temperature of aged PEEK increased as radiative and thermal ageing. The frequency dependency of dielectric properties implied that the magnitude of radiation and thermal induced dipoles, ions increased as radiative and thermal ageing. The values of relaxation intensity calculated using Cole-Cole's circular arc can be useful for evaluation of degradation level of PEEK.

Thermal stabilities and dynamic mechanical properties of dielectric materials for thermal imprint lithography (임프린트 공법적용을 위한 절연재료의 열적, 기계적 성질)

  • Cho, Jae-Choon;Ra, Seung-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.06a
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    • pp.220-221
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    • 2007
  • Recently, imprint lithography have received significant attention due to an alternative technology for photolithography on high performance microelectronic devices. In this work, we investigated thermal stabilities and dynamic mechanical properties of dielectric materials for thermal imprint lithography. Curing behaviours, thermal stabilities, and dynamic mechanical properties of the dielectric materials cured with various curing agent and spherical filler were studied using dynamic differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), rheometer and universal test machine(UTM).

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Epoxy-Based Siloxane/Silica Composites for Electronic Packaging by Composition and Molecular Structure of Siloxane, and Analysis of Changes in Properties (조성 및 실록산 분자 구조에 따른 전자 패키징용 에폭시 기반 실록산/실리카 복합체의 물성 변화 분석)

  • Junho Jang;Dong Jun Kang;Hyeon-Gyun Im
    • Journal of Powder Materials
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    • v.30 no.4
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    • pp.346-355
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    • 2023
  • Epoxy-based composites find extensive application in electronic packaging due to their excellent processability and insulation properties. However, conventional epoxy-based polymers exhibit limitations in terms of thermal properties and insulation performance. In this study, we develop epoxy-based siloxane/silica composites that enhance the thermal, mechanical, and insulating properties of epoxy resins. This is achieved by employing a sol-gel-synthesized siloxane hybrid and spherical fused silica particles. Herein, we fabricate two types of epoxy-based siloxane/silica composites with different siloxane molecular structures (branched and linear siloxane networks) and investigate the changes in their properties for different compositions (with or without silica particles) and siloxane structures. The presence of a branched siloxane structure results in hardness and low insulating properties, while a linear siloxane structure yields softness and highly insulating properties. Both types of epoxy-based siloxane/silica composites exhibit high thermal stability and low thermal expansion. These properties are considerably improved by incorporating silica particles. We expect that our developed epoxy-based composites to hold significant potential as advanced electronic packaging materials, offering high-performance and robustness.

Thermal Characteristics of Epoxy-Nanocomposites filled Several Types Nano Layered Silicate Particles (나노층상실리케이트가 충진된 에폭시-나노콤포지트의 열적특성 연구)

  • Park, Jae-Jun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.8
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    • pp.749-754
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    • 2008
  • A large number of studies on the various characteristics of epoxy-layered silicate nanocomposites, such as electric and mechanical, morphology have been conducted and contributed to improve their characteristics. However, studies on the effects of its thermal conductivities in the thermal properties are not enough, even though there are some excellent evaluations for its insulation performances. Thermal properties will cause thermal degradation and significantly affect the reliability of these epoxy-layered silicate nanocomposites. In the results of the analysis of epoxy-layered silicate nanocomposites $T_g$ for various types of organoclays (10A, 15A, 20A, 30B, and 93A), it showed an excellent thermal property of 10A. Also, it represented low values in storage modulus and mechanical Tan (Delta) at a high temperature section 140$^{\circ}C$ and excellent thermal properties due to its movement to the high temperature section in the case of the property of 10A in the measurement of DMA elastics and mechanical losses. In the results of the measurement of thermal conductivities, power ultrasonic applications represented a significant increase in thermal conductivities in the case of the applications of power ultrasonic and planetary centrifugal mixers. Based on these results, it is necessary to perform related studies because it can be applied as useful materials for future power facilities applications in mold and impregnate insulation.

The Properties of DSC and DMA for Epoxy Nano-and-Micro Mixture Composites

  • Lee, Chang-Hoon;Park, Jae-Jun
    • Transactions on Electrical and Electronic Materials
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    • v.11 no.2
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    • pp.69-72
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    • 2010
  • This study investigates the thermal and mechanical properties of insulation elements through the mixing of epoxy based micro and nano particles. Regarding their thermal properties, differential scanning calorimeter and dynamic mechanical analyser were used to calculate the cross-linking densities for various types of insulation elements. The mechanical properties of the bending strength, the shape and scale parameters, were obtained using the Weibull plot. This study obtained the best results in the scale parameters, at 0.5 phr, for the bending strength of the epoxy nano-and-micro mixture composites.

Defect Engineering for High-Performance Thermoelectric Semiconductors (결함제어를 통한 열전 반도체 연구 동향)

  • Min, Yuho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.35 no.5
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    • pp.419-430
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    • 2022
  • Defects in solids play a vital role on thermoelectric properties through the direct impacts of electronic band structure and electron/phonon transports, which can improve the electronic and thermal properties of a given thermoelectric semiconductor. Defects in semiconductors can be divided into four different types depending on their geometric dimensions, and thus understanding the effects on thermoelectric properties of each type is of a vital importance. This paper reviews the recent advances in the various thermoelectric semiconductors through defect engineering focusing on the charge carrier and phonon behaviors. First, we clarify and summarize each type of defects in thermoelectric semiconductors. Then, we review the recent achievements in thermoelectric properties by applying defect engineering when introducing defects into semiconductor lattices. This paper ends with a brief discussion on the challenges and future directions of defect engineering in the thermoelectric field.