Degradation Aging of BaTiO3 Microwave Ceramic Capacitors for EMI Applications at High-Voltage

2007 ◽  
Vol 336-338 ◽  
pp. 371-373
Author(s):  
Zhao Xian Xiong ◽  
Z.G. Su ◽  
Hong Qiu
Keyword(s):  
High Temperature ◽  
High Voltage ◽  
Sintering Temperature ◽  
High Reliability ◽  
Curing Agent ◽  
Ceramic Composition ◽  
Ceramic Capacitor ◽  
Microwave Ceramic ◽  
Ceramic Capacitors ◽  
Resin Curing

Degradation aging of BaTiO3 microwave ceramic capacitors for EMI applications at highvoltage, AC 10kV, was focused in this paper. Electric performances of the ceramic capacitors were systematically evaluated with thermal shock (5 cycles of –30 °C for 1 h and then 125°C for 1 h), damp heat (100% RH at 40°C for 500 h), and, endurance at high temperature (DC 10 kV at 100°C for 500 h). High reliability for the ceramic capacitor was obtained with optimal ceramic composition, sintering temperature, epoxy resin, curing agent and additives, which was satisfied with practical microwave technologies.

A 300°C High Reliability HALT/HAST Screening/Sorting Procedure for Ceramic Capacitors

2018 ◽  
Vol 2018 (HiTEC) ◽  
pp. 000129-000137 ◽  
Author(s):  
Harold L. Snyder
Keyword(s):  
High Reliability ◽  
Stress Test ◽  
Electrical Current ◽  
Accelerated Life Test ◽  
Test Results ◽  
Electrical Model ◽  
Current Leakage ◽  
Ceramic Capacitor ◽  
Ceramic Capacitors ◽  
Before And After

Abstract A highly accelerated life test (HALT) and highly accelerated stress test (HAST) procedure for ceramic capacitors developed by the author in the mid 1980's to early 1990's, and published in 1994, consists of a 400 Volt biased six (6) hour stress sort at 150°C (423K), a methanol current leakage test that located mechanical and structural cracks, a visual inspection at ten times (10×) magnification, and a capacitance and dissipation measurement before and after the test. In over thirty (30) years of use, there has never been a user reported in-circuit failure in industrial, military, and aerospace application at temperatures as high as 500°C (773K). However, reviewing user feedback, two concerns with the original sorting procedure are the stress is performed at 150°C (423K), and the lack of a more detailed ceramic capacitor electrical model. To address the first, the low aging temperature, the stress temperature was increased from 150°C to 300°C, in order to age ceramic solid state crystal mineral phases that may change with temperature. The test results for X7R and NP0/COG multilayer ceramic capacitors (MLCC) at 300°C, are compared to the test results using the original HALT/HAST procedure at 150°C. Differences between X7R/NP0/COG and porcelain capacitors are discussed when applicable. Further, a more detailed ceramic capacitor electrical model that represents the physical and electrical characteristics of the ceramic capacitors is presented, including the electrical current leakage effects with temperature, and the carbonized residue effects from the manufacturing process.

Demonstrated Performance Characteristics For Improved High Temperature Ceramic Capacitors Intended For Use In Extreme, Harsh Environments

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000188-000193
Author(s):  
Mustafa A. Syammach ◽  
Michael J. Roach ◽  
Fauzi A. Syammach ◽  
Mustapha Habibi
Keyword(s):  
High Temperature ◽  
Dielectric Material ◽  
Leading Edge ◽  
Performance Characteristics ◽  
Test Reliability ◽  
Operating Voltage ◽  
Insulation Resistance ◽  
Design Engineers ◽  
Ceramic Capacitor ◽  
Ceramic Capacitors

Availability of a reliable and consistent source for high temperature ceramic capacitors has been an ongoing issue for design engineers looking at developing product for applications up to and including +300°C. The general practice has been to derate standard X7R ceramic capacitors for high temperature applications and settle for a device characterized by a significant reduction in those critical performance features related to capacitance value, operating voltage, insulation resistance and breakdown voltage, not to mention a substantial roll off in temperature coefficient above +150°C. In addition, the need to provide coated and / or leaded options also presents additional concerns related to operational integrity. This paper presents packaging options, life test reliability data and compares performance characteristics for a unique high K, high temperature ceramic capacitor, to the more traditional options. This approach utilizes leading edge, Class II dielectric and packaging materials that have been specifically developed for use at +300°C and then benefit from enhanced reliability when operated at lower temperatures. As shown in this paper, capacitors manufactured with this dielectric material exhibit much higher capacitance per unit volume and significant improvements in insulation resistance, without having to sacrifice mechanical strength, voltage rating or long term reliability.

A 300°C High Reliability HALT/HAST Screening/Sorting Procedure for Ceramic Capacitors – Part 2

2021 ◽  
Vol 2021 (HiTEC) ◽  
pp. 000094-000099
Author(s):  
Harold L. Snyder
Keyword(s):  
High Reliability ◽  
Stress Test ◽  
Electrical Current ◽  
Accelerated Life Test ◽  
Test Results ◽  
Electrical Model ◽  
Current Leakage ◽  
Ceramic Capacitor ◽  
Ceramic Capacitors ◽  
Before And After

Abstract This is Part 2 of a study initially presented at HiTEC 2018, for context, some introductory material is duplicated. A highly accelerated life test (HALT) and highly accelerated stress test (HAST) procedure for ceramic capacitors developed by the author in the mid 1980’s to early 1990’s, and published in 1994, consists of a 400 Volt biased six (6) hour stress sort at 150°C (423K), a methanol current leakage test that located mechanical and structural cracks, a visual inspection at ten times (10X) magnification, and a capacitance and dissipation measurement before and after the test. In over thirty (30) years of use, there has never been a user reported in-circuit failure in industrial, military, and aerospace application at temperatures as high as 500°C (773K). However, reviewing user feedback, two concerns with the original sorting procedure are the stress is performed at 150°C (423K), and the lack of a more detailed ceramic capacitor electrical model. To address the first, the low aging temperature, the stress temperature was increased from 150°C to 300°C, in order to age ceramic solid state crystal mineral phases that may change with temperature. The test results for X7R and NP0/COG multilayer ceramic capacitors (MLCC) at 300°C, are compared to the test results using the original HALT/HAST procedure at 150°C. Differences between X7R/NP0/COG and porcelain capacitors are discussed when applicable. Further, a more detailed ceramic capacitor electrical model that represents the physical and electrical characteristics of the ceramic capacitors is presented, including the electrical current leakage effects with temperature, and the carbonized residue effects from the manufacturing process.

Advanced Ceramic Capacitor Solutions for High Temperature Applications

2013 ◽  
Vol 2013 (HITEN) ◽  
pp. 000025-000032
Author(s):  
Abhijit Gurav ◽  
Xilin Xu ◽  
Jim Magee ◽  
Paul Staubli ◽  
John Bultitude ◽  
...  
Keyword(s):  
High Temperature ◽  
Dielectric Material ◽  
Class I ◽  
Hole Drilling ◽  
Severe Reduction ◽  
Ceramic Capacitor ◽  
Ceramic Capacitors ◽  
Temperature Application ◽  
Reliability Performance ◽  
Temperature Applications

For high temperature applications at 150°C or above, such as those in electronics for down-hole drilling, geothermal energy generation and power electronics, a robust dielectric material is necessary for capacitors. Ceramic capacitors using X7R and X8R type dielectrics are designed for applications up to 125°C and 150°C, respectively. At temperatures above 150°C, these X7R/X8R types of ceramic capacitors typically suffer from degradation of reliability performance and severe reduction in capacitance, especially when bias is applied. Recently, a Class-I dielectric material has been developed using Nickel electrodes for high temperature application up to 200–250°C. Due to its linear dielectric nature, this material exhibits highly stable capacitance as a function of temperature and voltage. This paper will report electrical properties and reliability test data on these Class-I type ceramic capacitors in SMD chip and leaded configurations at 150–200°C and above, and discuss possible mechanisms behind the robust reliability of this high temperature dielectric.

Highly Integrated and Isolated Universal Half-Bridge Power Gate Driver and Associated Flyback Power Supply for High Temperature and High Reliability Applications

2014 ◽  
Vol 2014 (HITEC) ◽  
pp. 000206-000213
Author(s):  
David Gras ◽  
Christophe Pautrel ◽  
Amir Fanaei ◽  
Gregory Thepaut ◽  
Maxime Chabert ◽  
...  
Keyword(s):  
High Temperature ◽  
High Voltage ◽  
Power Supply ◽  
High Efficiency ◽  
High Reliability ◽  
System Level ◽  
Switching Frequency ◽  
Solder Paste ◽  
High Side ◽  
Gate Driver

In this paper we present a highly integrated, high-temperature isolated, half-bridge power gate driver demo board, based on turnkey X-REL chipset: XTR26010 (High-Temperature Intelligent Gate Driver), XTR40010 (High-Temperature Isolated Two Channel Transceiver), XTR30010 (High-Temperature PWM Controller), and XTR2N0825 (High-Temperature 80V N-Channel Power MOSFET). The XTR26010 is the key circuit in this chipset for power gate drive application. The XTR26010 circuit has been designed with a high focus in offering a robust, reliable and efficient solution for driving a large variety of high-temperature, high-voltage, and high-efficiency power transistors (SiC, GaN, Si) existing in the market. Furthermore, the XTR26010 circuit implements an unprecedented functionality for high-temperature drivers allowing safe operation at system level by preventing any cross-conduction between high-side and low-side switches, through isolated communication between high-side and low-side drivers. The XTR40010 is used for isolated data communication between a microcontroller or a PWM controller with the power driver (XTR26010). For supplying the half-bridge gate driver, a compact isolated flyback power supply has been developed thanks to the versatile voltage mode PWM controller XTR30010 and the XT2N0825 N-Channel MOSFET. The full system has been successfully tested while driving different brands of SiC MOSFETs up to Ta=200°C, 600kHz of switching frequency and 600V high-voltage bus (limited by isolation transformers used). The demo board presented can be easily modified to drive other SiC and GaN transistors available in the market. The 200°C limitation of the demo board is due to passives, PCB material, and the solder paste used. However, all X-REL active circuits have been qualified within specifications well above 230°C.

Preparation and Characteristic of Composites with Wheat Straw Woodceramic / Attapulgite

2013 ◽  
Vol 330 ◽  
pp. 126-130 ◽  
Author(s):  
Wen Tao Wu ◽  
Fang Liang Tan ◽  
Feng Xu
Keyword(s):  
High Temperature ◽  
Wheat Straw ◽  
Phenolic Resin ◽  
Raw Materials ◽  
Curing Agent ◽  
Research Directions ◽  
Physical Strength ◽  
New Research ◽  
Resin Curing ◽  
Composite Carbon

This paper mainly introduces that the wheat straw, attapulgite and phenolic resin, curing agent respectively usded as raw materials and the auxiliary materials , and those were finally prepared as a new composite carbon material through the processes of mixing, drying ,hot pressing, as well as high temperature sintering. The different sintering temperatures and different ratios of different materials were fabricated, then the material physical strength, density, porosity, strength, resistivity and other properties were tested. After which, the performance, formation mechanism and formation law were analyzed ,the effect of the choice and ratio materials and the temperature to the preparation as well as the properties of composite materials were preliminarily discussed, Identified as wheat straw: attapulgite = 2: 1; 3: 1, a temperature of 700 to 800 DEG C when all the material physical properties of ideal.. This experiment showed that wheat straw as raw materials for preparing attapulgite feasibility. At the same time, the presented work also opens up new research directions to the reuse utilization of wheat straw ,the application of attapulgite as well as research of woodceramics composites.

C0G and X7R Ceramic Capacitors for High Temperature Applications

2016 ◽  
Vol 2016 (HiTEC) ◽  
pp. 000290-000298
Author(s):  
Abhijit Gurav ◽  
Jim Magee ◽  
Reggie Phillips ◽  
Scott Carson
Keyword(s):  
High Temperature ◽  
High Reliability ◽  
Extreme Temperature ◽  
Class Ii ◽  
Class I ◽  
Hole Drilling ◽  
Ceramic Capacitors ◽  
Temperature Application ◽  
Reliability Performance ◽  
Robust Reliability

Abstract For applications such as electronics for down-hole drilling and exploration, geothermal energy generation and power electronics, there is a growing need for capacitors that have robust reliability at temperatures of 150°C or above. Conventional X7R and X8R type ceramic capacitors are designed for applications up to 125°C and 150°C, respectively. At temperatures above 150°C, these types of capacitors typically suffer from degradation of reliability performance and severe reduction in capacitance, especially under DC bias conditions. A Class-I C0G dielectric has been developed using Nickel electrodes for high temperature application up to 200°C and beyond. Due to its linear dielectric nature, this material exhibits highly stable capacitance as a function of temperature and voltage. Multi-layer ceramic capacitors (MLCC) made from this material can be qualified as X9G with robust reliability. These C0G capacitors are showing robust reliability at extreme temperature of 260°C (500 degrees Fahrenheit). We have also developed a modified-X7R dielectric composition with nickel internal electrodes showing high reliability in this Class-II dielectric at 175°C. This paper will report electrical properties and reliability test data on these Class-I C0G and Class-II ceramic capacitors at high temperatures of 150–200°C and above.

An Environmental Wet Cell For High Voltage Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 18-19
Author(s):  
N.J. Tighe ◽  
H.M. Flower ◽  
P.R. Swann
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Image Quality ◽  
Inelastic Scattering ◽  
High Voltage ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Environmental Cell ◽  
Water Saturated ◽  
High Temperature Gas

A differentially pumped environmental cell has been developed for use in the AEI EM7 million volt microscope. In the initial version the column of gas traversed by the beam was 5.5mm. This permited inclusion of a tilting hot stage in the cell for investigating high temperature gas-specimen reactions. In order to examine specimens in the wet state it was found that a pressure of approximately 400 torr of water saturated helium was needed around the specimen to prevent dehydration. Inelastic scattering by the water resulted in a sharp loss of image quality. Therefore a modified cell with an ‘airgap’ of only 1.5mm has been constructed. The shorter electron path through the gas permits examination of specimens at the necessary pressure of moist helium; the specimen can still be tilted about the side entry rod axis by ±7°C to obtain stereopairs.

Electron Microscopy of Silicon Nitride-Based Ceramics

1991 ◽  
Vol 49 ◽  
pp. 926-927
Author(s):  
Gareth Thomas
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Silicon Nitride ◽  
World Wide ◽  
Sintering Temperature ◽  
Liquid Phase Sintering ◽  
High Temperature Strength ◽  
Sintering Additives ◽  
Glass Forming ◽  
Dense Product

Silicon nitride and silicon nitride based-ceramics are now well known for their potential as hightemperature structural materials, e.g. in engines. However, as is the case for many ceramics, in order to produce a dense product, sintering additives are utilized which allow liquid-phase sintering to occur; but upon cooling from the sintering temperature residual intergranular phases are formed which can be deleterious to high-temperature strength and oxidation resistance, especially if these phases are nonviscous glasses. Many oxide sintering additives have been utilized in processing attempts world-wide to produce dense creep resistant components using Si3N4 but the problem of controlling intergranular phases requires an understanding of the glass forming and subsequent glass-crystalline transformations that can occur at the grain boundaries.

Sign in / Sign up

Export Citation Format

Share Document