Enhancing Breakdown Strength and Lifetime of Multilayer Dielectric Films by using High Temperature Polycarbonate Skin Layers

There is a long-standing puzzle concerning whether polyethylene blends are a suitable substitution for cable-insulation-used crosslinking polyethylene (XLPE) especially at elevated temperatures. In this paper, we investigate temperature dependence of mechanical, electrical properties of blends with 70 wt % linear low density polyethylene (LLDPE) and 30 wt % high density polyethylene (HDPE) (abbreviated as 70 L-30 H). Our results show that the dielectric loss of 70 L-30 H is about an order of magnitude lower than XLPE, and the AC breakdown strength is 22% higher than XLPE at 90 °C. Moreover, the dynamic mechanical thermal analysis (DMA) measurement and hot set tests suggest that the blends shows optimal mechanical properties especially at high temperature with considerable temperature stability. Further scanning electron microscope (SEM) observation and X-ray diffraction (XRD) analysis uncover the reason for the excellent high temperature performance and temperature stability, which can be ascribed to the uniform fine-spherulite structure in 70 L-30 H blends with high crystallinity sustaining at high temperature. Therefore, our findings may enable the potential application of the blends as cable insulation material with higher thermal-endurance ability.

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Исследование нелегированных нанокристаллических алмазных пленок, выращенных из газовой фазы в плазме СВЧ разряда

Физика и техника полупроводников ◽

10.21883/ftp.2021.01.50387.9520 ◽

2021 ◽

Vol 55 (1) ◽

pp. 49

Author(s):

А.Л. Вихарев ◽

С.А. Богданов ◽

Н.М. Овечкин ◽

О.А. Иванов ◽

Д.Б. Радищев ◽

...

Keyword(s):

High Temperature ◽

Vapor Deposition ◽

Microwave Plasma ◽

Chemical Vapor ◽

Growth Conditions ◽

Inert Gas ◽

Dielectric Films ◽

High Temperature Annealing ◽

Structural And Electrical Properties ◽

Methane Mixture

Undoped nanocrystalline diamond (NCD) films less than 1 μm thick grown on Si (100) silicon by microwave plasma-assisted chemical vapor deposition at a frequency of 2.45 GHz are studied. To obtain diamond dielectric films with maximum resistivity the deposition of films in three gas mixtures is investigated: hydrogen-methane mixture, hydrogen-methane mixture with the addition of oxygen and hydrogen-methane mixture with the addition of an inert gas. A relationship has been established between the growth conditions, structural and electrical properties of NCD films. It is shown that for the use of NCD films as effective dielectrics preliminary high-temperature annealing of the films is required, for example, in vacuum at a temperature of 600°C for one hour.

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High Temperature Performance of Coiled Glass Capacitors

Additional Conferences (Device Packaging HiTEC HiTEN & CICMT) ◽

10.4071/hitec-wa25 ◽

2012 ◽

Vol 2012 (HITEC) ◽

pp. 000192-000198 ◽

Cited By ~ 1

Author(s):

Eugene Furman ◽

Amanda Baker ◽

Steve Perini ◽

Mohan Monoharan ◽

Douglas Kushner ◽

...

Keyword(s):

High Temperature ◽

Dielectric Breakdown ◽

Breakdown Strength ◽

Temperature Stability ◽

Sodium Content ◽

Flat Panel Display ◽

High Temperature Stability ◽

Thin Glass ◽

High Dielectric ◽

Power Capability

Alkali-free flat panel display glass is produced in large quantity and has excellent electrical insulating properties at high temperature. Aluminum borosilicate glass with alkaline-earth modifier has low sodium content and low dielectric loss (tan δ <0.1 at 250°C), high dielectric breakdown strength (109 V/m) and excellent high temperature stability. In addition, roll-to-roll processing of thin glass sheet has been demonstrated and glass capacitors that are configured in a coil. Excellent high power capability of these glasses was confirmed by analytical, finite element, and finite difference modeling. The modeling work indicates that a combination of hybrid electrode design and effective heat loss at the interface can further extend power capability of glass capacitors. Alkali-free glass is an ideal candidate material for high temperature capacitors.

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Dielectric Breakdown Mechanism of Perovskite-Structured Ceramics

Additional Conferences (Device Packaging HiTEC HiTEN & CICMT) ◽

10.4071/cicmt-tp43 ◽

2015 ◽

Vol 2015 (CICMT) ◽

pp. 000116-000120 ◽

Cited By ~ 3

Author(s):

Takuya Hoshina ◽

Mikio Yamazaki ◽

Hiroaki Takeda ◽

Takaaki Tsurumi

Keyword(s):

High Temperature ◽

Room Temperature ◽

Oxygen Vacancies ◽

Dielectric Breakdown ◽

Breakdown Strength ◽

Dielectric Breakdown Strength ◽

Breakdown Mechanism ◽

High Dielectric ◽

Measurement Efficiency ◽

Breakdown Model

We precisely measured the dielectric breakdown strength of SrTiO3, CaTiO3, and CaZrO3 ceramics as a function of temperature, and revealed the dielectric breakdown mechanism of the ceramics. For the dielectric breakdown test, ceramics specimens with a lot of round-bottom holes were prepared. Using the specimens, the breakdown positions were stabilized and a reliability of breakdown strength was improved as well as the measurement efficiency. As a result of the dielectric breakdown tests, it was found that the dielectric breakdown strength decreased with increasing permittivity at room temperature and the permittivity dependence of breakdown strength obeyed Griffith type energy release rate model. At high temperature above 100ºC, the dielectric breakdown mechanism of SrTiO3 and CaTiO3 ceramics was explained by an intrinsic breakdown model. In contrast, an intrinsic dielectric breakdown of CaZrO3 ceramics didn't occur in the measurement temperature range up to 210ºC. To obtain a high dielectric breakdown strength at high temperature, the dielectric permittivity is required to be low to some extent and the defect concentration of oxygen vacancies should be minimized in the perovskite-structured oxide.

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The Effects of Aluminum-Nitride Nano-Fillers on the Mechanical, Electrical, and Thermal Properties of High Temperature Vulcanized Silicon Rubber for High-Voltage Outdoor Insulator Applications

Materials ◽

10.3390/ma12213562 ◽

2019 ◽

Vol 12 (21) ◽

pp. 3562 ◽

Cited By ~ 1

Author(s):

Chang Liu ◽

Yiwen Xu ◽

Daoguang Bi ◽

Bing Luo ◽

Fuzeng Zhang ◽

...

Keyword(s):

Contact Angle ◽

Thermal Properties ◽

High Temperature ◽

High Voltage ◽

Breakdown Strength ◽

Electrical Breakdown ◽

Theoretical Models ◽

Dielectric Constants ◽

Silicon Rubber ◽

Electrical Breakdown Strength

AlN nanoparticles were added into commercial high-temperature-vulcanized silicon rubber composites, which were designed for high-voltage outdoor insulator applications. The composites were systematically studied with respect to their mechanical, electrical, and thermal properties. The thermal conductivity was found to increase greatly (>100%) even at low fractions of the AlN fillers. The electrical breakdown strength of the composites was not considerably affected by the AlN filler, while the dielectric constants and dielectric loss were found to be increased with AlN filler ratios. At higher doping levels above 5 wt% (~2.5 vol%), electrical tracking performance was improved. The AlN filler increased the tensile strength as well as the hardness of the composites, and decreased their flexibility. The hydrophobic properties of the composites were also studied through the measurements of temperature-dependent contact angle. It was shown that at a doping level of 1 wt%, a maximum contact angle was observed around 108°. Theoretical models were used to explain and understand the measurement results. Our results show that the AlN nanofillers are helpful in improving the overall performances of silicon rubber composite insulators.

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