Multilayer Chip Capacitor Equivalent Circuit Model for Impedance Accuracy
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Solution Overview
Problem
Existing equivalent circuit models for multilayer chip capacitors fail to accurately reflect the characteristics of actual capacitors, leading to significant errors in circuit design and performance prediction, especially due to frequency-dependent components and complexity in polynomial expressions.
Innovation Solution
An equivalent circuit model for multilayer chip capacitors is developed, incorporating specific parallel and series circuits to represent electromagnetic and parasitic effects, metal skin effects, and dielectric losses, along with a method to determine circuit constants that minimize relative errors between simulated and actual impedance values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a simple RLC series circuit is used as an equivalent circuit model, then the device complexity is reduced, but the measurement precision of capacitor characteristics deteriorates due to frequency-dependent errors
Solution Approach 1:
The equivalent circuit is segmented into multiple parallel circuits, each representing different physical effects (electrostatic capacitance, electromagnetic effects, skin effects, dielectric losses). This segmentation allows each circuit element to independently model specific characteristics, improving overall accuracy without requiring a single complex element.
Solution Approach 2:
Different parts of the equivalent circuit are assigned different qualities to represent local physical phenomena. For example, parallel circuits with specific R-L-C combinations model localized effects like skin effects on electrode surfaces and dielectric losses in specific regions, allowing precise representation of frequency-dependent behavior.
2Adaptability or versatility
If general polynomial formulas are used for circuit modeling, then the adaptability is improved, but the device complexity increases due to high-order polynomial expressions
Solution Approach 1:
Instead of using a single high-order polynomial formula, the model segments the frequency response into multiple parallel circuits with simpler R-L-C combinations. Each parallel circuit handles a specific frequency range or physical effect, making the overall model more adaptable while keeping individual expressions simple.
Solution Approach 2:
The model uses parameter changes through frequency-dependent resistance and inductance values in parallel circuits rather than complex polynomial expressions. By adjusting R and L parameters across different parallel circuits, the model adapts to various frequency conditions without requiring high-order mathematics.
3Measurement precision
If frequency-dependent circuit elements are used to improve accuracy, then the measurement precision is improved, but the device complexity increases due to multiple frequency-dependent components
Solution Approach 1:
The frequency-dependent behavior is segmented across multiple parallel circuits, each with its own R-L-C combination. This distributes the complexity across independent modules rather than concentrating it in a single complex element, making the model more manageable while maintaining precision.
Solution Approach 2:
The model uses multiple copies of similar parallel circuit structures (R-L-C combinations) to represent different physical effects. These copied structures follow the same pattern but with different parameter values, simplifying the design process while capturing multiple frequency-dependent phenomena.
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 proposed model effectively suppresses errors associated with frequency variations, providing accurate circuit design and performance prediction by incorporating detailed electromagnetic and parasitic effects, improving the accuracy of circuit simulations.
Implementation Method 1
a first parallel circuit connecting the capacitance C1 and the resistance Rc1 in parallel, which represent electromagnetic effects present in a dielectric contacting a respective upper surface of a plurality of internal electrodes
Implementation Method 2
a third series circuit connecting a inductance L1 and a resistance RL1 in series that respectively represent metal skin effects on the upper and lower surfaces, respectively, of the plurality of internal electrodes
Implementation Method 3
a second parallel circuit connecting a parasitic capacitance Cp in the dielectric in parallel with an insulation resistance Rp2 that represents a loss in the dielectric
Implementation Method 4
a fourth parallel circuit connecting a mutual inductance Lm for electromagnetic proximity effects in parallel with the third series circuit
Data Source
AI summary
Improved equivalent circuits and circuit analysis using the same for a multilayer capacitor are provided. In one aspect, the equivalent series capacitance C and part of the equivalent series resistance R of a basic equivalent circuit for a multilayer chip capacitor are replaced with a capacitance CO, and capacitances Cm and C1 and the resistance Rc1 to take into consideration abnormal characteristics in electromagnetic distribution that occur at the corners and edges of the internal electrodes in the multilayer chip capacitor. In one aspect, additional circuit elements, such as resistances Rp1 and Rp2, the capacitance Cp, the inductances Lm and L1, and the resistance RL1, are provided to take into consideration the skin effects of the internal electrodes within the multilayer chip capacitor, electromagnetic proximity effects, losses and parasitic capacitance of the dielectric material, as well as parasitic inductance of the external electrodes.