Class-I and Class-II Ceramic Capacitors for High Temperature Applications

2014 ◽  
Vol 2014 (HITEC) ◽  
pp. 000121-000128
Author(s):  
Abhijit Gurav ◽  
Xilin Xu ◽  
Jim Magee ◽  
Reggie Phillips ◽  
Travis Ashburn
Keyword(s):  
High Temperature ◽  
Class Ii ◽  
Class I ◽  
Hole Drilling ◽  
Severe Reduction ◽  
Ceramic Capacitors ◽  
Temperature Application ◽  
Dc Bias ◽  
Reliability Performance ◽  
Robust Reliability

There is a growing need for ceramic capacitors for applications at temperatures of 150°C or above, such as electronics for down-hole drilling and exploration, geothermal energy generation and power electronics. 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. Recently, 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. We have also developed a modified-X7R dielectric composition with nickel internal electrodes to design robust 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.

Advances in Ceramic Capacitors for High Temperature Applications

2015 ◽  
Vol 2015 (HiTEN) ◽  
pp. 000134-000141 ◽  
Author(s):  
Abhijit Gurav ◽  
Xilin Xu ◽  
Jim Magee ◽  
Reggie Phillips ◽  
Travis Ashburn
Keyword(s):  
High Temperature ◽  
Class Ii ◽  
Class I ◽  
Hole Drilling ◽  
Severe Reduction ◽  
Ceramic Capacitors ◽  
Temperature Application ◽  
Dc Bias ◽  
Reliability Performance ◽  
Robust Reliability

There is a growing need for capacitors for applications at temperatures of 150°C or above, such as electronics for down-hole drilling and exploration, geothermal energy generation and power electronics. 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. Recently, 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. A Class-II modified-X7R dielectric composition with nickel internal electrodes showing robust reliability at 175°C has also recently been developed. 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.

Ceramic Capacitors and Stacks for High Temperature Applications

2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000030-000037 ◽  
Author(s):  
Abhijit Gurav ◽  
Xilin Xu ◽  
Jim Magee ◽  
John Bultitude ◽  
Travis Ashburn
Keyword(s):  
High Temperature ◽  
Dielectric Material ◽  
Class I ◽  
Hole Drilling ◽  
Severe Reduction ◽  
Ceramic Capacitors ◽  
Temperature Application ◽  
Dc Bias ◽  
Reliability Performance ◽  
Robust Reliability

There is a growing need for ceramic capacitors for applications at temperatures of 150°C or above, such as electronics for down-hole drilling, geothermal energy generation and power electronics. In traditional X8R ceramic capacitors (EIA specification, TCC or ΔC/C within ±15% between −55°C and +150°C compared that at 25°C), the dielectric material is designed for applications up to 150°C. However, at temperatures above 150°C, the X8R capacitors typically suffer from degradation of reliability performance and severe reduction in capacitance, especially under DC bias conditions. Recently, 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. This paper will report electrical properties and reliability test data on these Class-I C0G ceramic capacitors at high temperatures at 150–200°C and above along with a discussion of possible mechanisms behind the robust reliability of this high temperature dielectric.

Robust Class-I BME Ceramic Capacitors for High Temperature Applications

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000251-000258
Author(s):  
Abhijit Gurav ◽  
Xilin Xu ◽  
Jim Magee ◽  
Jeff Franklin ◽  
Travis Ashburn
Keyword(s):  
High Temperature ◽  
Test Data ◽  
Dielectric Material ◽  
Class I ◽  
Severe Reduction ◽  
Ceramic Capacitors ◽  
Temperature Application ◽  
Dc Bias ◽  
Reliability Performance ◽  
Robust Reliability

In capacitors for applications at temperatures of 150°C or above, such as automotive under-the-hood electronics and power electronics, a robust dielectric material is necessary. In traditional X8R ceramic capacitors (EIA specification, ΔC/C within ±15% between −55°C and +150°C compared that at 25°C), the dielectric material is designed for applications up to 150°C. However, at temperatures above 150°C, the X8R capacitors typically suffer from degradation of reliability performance and severe reduction in capacitance, especially under DC bias conditions. Recently, a Class-I C0G dielectric has been developed using Nickel electrodes for high temperature application up to 200°C. 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. This paper will report electrical properties and reliability test data on these Class-I C0G ceramic capacitors at temperatures ≥150°C. In addition, test data from D-E curves and energy density measurements will be reported along with a discussion of possible mechanisms behind the robust reliability of this material.

SMD and Leaded Ceramic Capacitors for High Temperature Applications

2012 ◽  
Vol 2012 (HITEC) ◽  
pp. 000284-000291
Author(s):  
Abhijit Gurav ◽  
Xilin Xu ◽  
Jim Magee ◽  
John Bultitude ◽  
Travis Ashburn
Keyword(s):  
High Temperature ◽  
Dielectric Material ◽  
Class I ◽  
Hole Drilling ◽  
Severe Reduction ◽  
Ceramic Capacitors ◽  
Temperature Application ◽  
Dc Bias ◽  
Reliability Performance ◽  
Temperature Applications

For high temperature applications at 150°C or above, such as in electronics for down-hole drilling, geothermal energy generation, power electronics and automotive under the hood electronics, a robust dielectric material is necessary for capacitors. Common 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. 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. Multi-layer ceramic capacitors (MLCCs) made from this material can be qualified as X9G. 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 along with a discussion of possible mechanisms behind the robust reliability of this high temperature dielectric.

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.

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.

Robust Reliability of Ceramic Capacitors for Power Electronics

2018 ◽  
Vol 2018 (HiTEC) ◽  
pp. 000138-000142
Author(s):  
Abhijit Gurav ◽  
John Bultitude ◽  
John McConnell ◽  
Reggie Phillips
Keyword(s):  
High Temperature ◽  
Power Electronics ◽  
Transient Liquid Phase ◽  
Form Factors ◽  
Liquid Phase Sintering ◽  
Class I ◽  
Hole Drilling ◽  
Capacitance Density ◽  
Ceramic Capacitors ◽  
Robust Reliability

Abstract For applications using Wide Band Gap (WBG) semiconductors, and for electronics for down-hole drilling, oil exploration, geothermal energy generation and power electronics, there is a growing need for capacitors that have robust reliability at temperatures of 125°C, 150°C or above. The development of more energy efficient power converters and inverters based on WBG semiconductors is driving the adoption of higher temperatures in a growing number of power electronics and automotive circuits since these operate at higher junction temperatures than traditional silicon. This has led to a growing need for high temperature capacitors with robust reliability. A Class-I C0G dielectric has been developed using Nickel electrodes for high temperature application up to 200°C and beyond. Since it is a paraelectric linear dielectric, these capacitors exhibit highly stable capacitance as a function of temperature and voltage, possess low loss (DF) and can conduct high RMS currents with a low temperature rise compared to other capacitor solutions. To maximize the capacitance density and achieve a high degree of mechanical robustness, stacks and leaded form factors are commonly needed. Materials for assembly of stacks are of interest due to the challenge of higher cost of attachment materials based on gold-solders or nano-silver pastes, as well as due to the presence of lead (Pb) in common high melting point (HMP) solders. This paper will report electrical properties and reliability test data on these Class-I C0G ceramic capacitors and stacks at high temperatures. It will also review thermal robustness and electrical characteristics of stacks assembled using Pb-free transient liquid phase sintering (TLPS) materials based on Sn-Cu and In-Ag.

Stacked Ceramic Capacitors for High Temperatures (≥200°C)

2014 ◽  
Vol 2014 (HITEC) ◽  
pp. 000112-000120 ◽  
Author(s):  
John Bultitude ◽  
Lonnie Jones ◽  
John McConnell ◽  
Abhijit Gurav
Keyword(s):  
High Temperature ◽  
Shear Test ◽  
Dielectric Material ◽  
Hole Drilling ◽  
Well Control ◽  
Solder Interconnects ◽  
Deep Well ◽  
Ceramic Capacitors ◽  
Reliable Performance ◽  
Temperature Shear

High temperature applications at 200°C or above in electronics for down-hole drilling are driving the development of capacitors with ever more reliable performance. Deeper wells with increased temperatures and pressures have resulted in exposure to harsher conditions for longer times for the electronics used in the extraction tools and deep-well control instrumentation. The capacitor solutions currently available for 200°C operation are reviewed by value and rated voltage. Some key reliability factors attributed of the various technologies are identified. The recent development of stacks made using multi-layer ceramic capacitors (MLCC) of Class-I C0G type dielectric material with nickel inner electrodes are outlined with respect to their performance benefits at ≥ 200°C. Due to its linear dielectric nature this material exhibits highly stable capacitance as a function of temperature and voltage. The development of higher voltages and larger case size capacitors using this technology is discussed together with their incorporation into stacked ceramic capacitors by soldering on lead frames. Stacks of multi-layer ceramic capacitors (MLCC) allow capacitance to be maximized within the volume available. However, the solder interconnects must be evaluated to assess the long term reliability of the stacks at higher temperatures particularly with respect to maintaining mechanical and electrical integrity. The development of a custom high temperature shear test to evaluate the performance of different solder interconnects at temperatures from 200 to 260°C is described. Evaluations of two different HMP Pb-based solders are presented. The high and low temperature shear test data acquired for these solders is analyzed in terms of the strain and strain energy when force is applied. Changes in performance after exposure to temperatures ≥ 200°C are assessed. The results are interpreted with respect to the values required to survive high g-forces and the performance of the different solder compositions. Performance considerations for high shear strength interconnects at 200°C and beyond are discussed.

Electron microscopy analysis of degenerating pancreatic ß cells in transgenic mice expressing the MHC Class I antigen Dd

1990 ◽  
Vol 48 (3) ◽  
pp. 548-549
Author(s):  
T. A. Stewart ◽  
D. Liggitt ◽  
S. Pitts ◽  
L. Martin ◽  
M. Siegel ◽  
...  
Keyword(s):  
Type I Diabetes ◽  
Disease Process ◽  
Class Ii ◽  
Class I ◽  
Type I ◽  
Aberrant Expression ◽  
Mhc Molecules ◽  
Endogenous Insulin ◽  
Class Ii Mhc ◽  
Ifn Γ

Insulin-dependant (Type I) diabetes mellitus (IDDM) is a metabolic disorder resulting from the lack of endogenous insulin secretion. The disease is thought to result from the autoimmune mediated destruction of the insulin producing ß cells within the islets of Langerhans. The disease process is probably triggered by environmental agents, e.g. virus or chemical toxins on a background of genetic susceptibility associated with particular alleles within the major histocompatiblity complex (MHC). The relation between IDDM and the MHC locus has been reinforced by the demonstration of both class I and class II MHC proteins on the surface of ß cells from newly diagnosed patients as well as mounting evidence that IDDM has an autoimmune pathogenesis. In 1984, a series of observations were used to advance a hypothesis, in which it was suggested that aberrant expression of class II MHC molecules, perhaps induced by gamma-interferon (IFN γ) could present self antigens and initiate an autoimmune disease. We have tested some aspects of this model and demonstrated that expression of IFN γ by pancreatic ß cells can initiate an inflammatory destruction of both the islets and pancreas and does lead to IDDM.

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