Dielectric Material Capacitor Temperature Stability
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Solution Overview
Problem
Conventional capacitors exhibit significant capacitance variation with temperature and applied voltage, making them unsuitable for high-temperature environments and AC applications, and they often have high dissipation factors, particularly in higher capacitance ranges like X7R and X8R.
Innovation Solution
A dielectric material comprising bismuth ferrite, strontium titanate, and barium titanate, with manganese as an additive, is used to create a capacitor with improved temperature stability, reduced sensitivity to applied voltage, and lower dissipation factors, achieving high energy density and compliance with X7R or X8R specifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional dielectric materials are used in capacitors, then high capacitance values can be achieved, but the capacitance varies considerably with temperature and applied voltage
Solution Approach 1:
The patent employs a composite dielectric material comprising barium titanate (BaTiO3) as the primary component, strontium titanate (SrTiO3) as a secondary component, and calcium zirconate (CaZrO3) as a tertiary component. This multi-component composite approach allows the capacitor to achieve high capacitance values while maintaining stability across temperature and voltage variations, resolving the contradiction between high capacitance and capacitance stability.
Solution Approach 2:
The patent optimizes specific compositional parameters including the weight ratios of BaTiO3 (60-90%), SrTiO3 (5-30%), and CaZrO3 (1-10%), along with controlled doping levels of manganese (0.1-5%) and other metal oxides. By precisely controlling these compositional parameters, the invention achieves both high capacitance and improved stability under varying temperature and voltage conditions.
2Quantity of substance
If conventional dielectric materials are used, then high capacitance is achieved, but dissipation factor remains high particularly in X7R and X8R ranges
Solution Approach 1:
The patent reduces dissipation factor by optimizing compositional parameters including precise control of BaTiO3 content (60-90%), SrTiO3 content (5-30%), and CaZrO3 content (1-10%). The controlled doping with manganese oxide (0.1-5%) and other metal oxides further refines the electrical properties, achieving low dissipation factors while maintaining high capacitance values in the X7R and X8R temperature ranges.
Solution Approach 2:
The patent introduces localized doping with specific metal oxides (manganese, nickel, cobalt, zinc) at controlled concentrations (0.1-5% each) to modify local regions of the dielectric material. This localized compositional modification optimizes electrical properties including reducing dissipation factor while preserving high capacitance characteristics in specific regions of the material.
3Quantity of substance
If conventional dielectric materials are used, then capacitors can operate at high capacitance values, but they exhibit high sensitivity to applied voltage
Solution Approach 1:
The patent develops a composite dielectric system combining BaTiO3, SrTiO3, and CaZrO3 where each component contributes specific electrical properties. The BaTiO3 provides high capacitance, while SrTiO3 and CaZrO3 contribute to voltage stability. This composite structure enables the capacitor to maintain high capacitance values while reducing sensitivity to applied voltage variations.
Solution Approach 2:
The patent optimizes the compositional parameters including the ratio of BaTiO3 to SrTiO3 to CaZrO3, the doping concentration of manganese (0.1-5%), and the presence of other metal oxides (nickel, cobalt, zinc at 0.1-5% each). These parameter optimizations create a dielectric material that maintains stable capacitance characteristics across varying applied voltage conditions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The capacitors demonstrate reduced capacitance variation with temperature and voltage, lower dissipation factors, and enhanced reliability, making them suitable for high-temperature applications and AC use, while maintaining efficiency and performance across a wide range of conditions.
Implementation Method 1
The dielectric material comprises bismuth ferrite, strontium titanate and an additive comprising barium titanate
Implementation Method 2
bismuth ferrite exhibits good temperature stability and reduced charge leakage
Data Source
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AI summary
A dielectric material suitable for use in an electronic component includes bismuth ferrite, strontium titanate and an additive. The additive comprises barium titanate. The barium titanate reduces the temperature capacitance change of the dielectric material and allows for increased working voltages. The material is useful for the construction of capacitors, and particularly capacitors intended for use at high temperatures. Also provided are a capacitor including the dielectric material, methods of manufacturing the dielectric material and the capacitor, and the use of an additive to improve the lifetime and/or reduce the dissipation factor of a capacitor.