Multilayered Ceramic Capacitor ESR Control for Ringing Suppression
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Solution Overview
Problem
Multilayer ceramic capacitors in electronic devices face challenges with increased switching speed leading to electromagnetic interference (EMI) and efficiency loss due to ringing phenomena, which existing C-R snubber technologies partially address but at the cost of conversion efficiency.
Innovation Solution
A multilayered ceramic capacitor design with specific internal and external electrode configurations and connection conductors that control equivalent series resistance (ESR) differently across frequency bands, enhancing high-frequency ESR to suppress ringing without affecting low-frequency capacitance and conversion efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If switching speed is increased to improve power supply efficiency, then conversion efficiency is improved, but electromagnetic interference and ringing phenomena occur
Solution Approach 1:
The patent applies local quality by creating capacitor parts with different capacitance values (first capacitor part with larger capacitance, second capacitor part with smaller capacitance) to address different frequency components of EMI locally. The internal connection conductor is strategically positioned to provide localized ESR control at specific points in the circuit path, suppressing ringing phenomena without affecting overall switching speed.
Solution Approach 2:
The patent changes the ESR parameter selectively - increasing ESR in high-frequency bands through the internal connection conductor configuration while maintaining low ESR in low-frequency bands. This parameter change allows the capacitor to suppress high-frequency noise and ringing while preserving conversion efficiency at lower frequencies.
2Object-generated harmful factors
If C-R snubber is added to FET to suppress ringing, then electromagnetic interference is reduced, but conversion efficiency deteriorates due to power consumption
Solution Approach 1:
The patent introduces an intermediary element - the internal connection conductor with specific ESR characteristics - that mediates between the capacitor electrodes and external circuits. This intermediary provides the necessary damping to suppress ringing phenomena without requiring active C-R snubber circuits that consume power, thereby maintaining conversion efficiency while reducing EMI.
3Volume of moving object
If component size is reduced to improve integration in portable devices, then ease of mounting is improved, but electromagnetic interference control becomes more difficult
Solution Approach 1:
The patent applies the nested doll principle by placing the internal connection conductor within the ceramic body structure, nesting multiple functional elements (first capacitor part, second capacitor part, internal connection conductor) within each other. This allows EMI control functionality to be integrated within the compact capacitor structure itself, maintaining small overall size while providing effective ESR control for suppressing ringing and EMI.
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 design effectively reduces noise and maintains high conversion efficiency by increasing ESR in high-frequency bands, thereby minimizing EMI and efficiency loss, while allowing for smaller component sizes and reduced mounting costs.
Implementation Method 1
Equivalent series resistance (ESR) of the multilayered ceramic capacitor may be increased in a high frequency band rather than in a low frequency band
Implementation Method 2
the first capacitor part has capacitance larger than that of the second capacitor part
Data Source
AI summary
There is provided a multilayered ceramic capacitor including a ceramic body including a plurality of dielectric layers and having first and second main surfaces, first and second side surfaces, and first and second end surfaces; a first capacitor part including a first internal electrode exposed to the first end surface and a second internal electrode exposed to the second end surface, and a second capacitor part including a third internal electrode exposed to the first end surface and a fourth internal electrode exposed to the second side surface; an internal connection conductor exposed to the first and second side surfaces; and first to fourth external electrodes formed on the outer surfaces of the ceramic body and electrically connected to the first to fourth internal electrodes and the internal connection conductor, wherein the first capacitor part has capacitance larger than that of the second capacitor part.