Multilayer Capacitor Segmented Regions Reduce EMI
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Solution Overview
Problem
In IT devices like smartphones and tablets, high frequency noise and electromagnetic interference (EMI) caused by DC-DC converters lead to communication obstacles and sound quality deterioration due to ringing from inductance and parasitic capacitance during switching of field effect transistors.
Innovation Solution
A multilayer capacitor design with a capacitor body featuring a first capacitance forming region thicker than a second, and a connection region with dummy electrodes adjacent to the first region, reducing high frequency noise and EMI by increasing ESR and parasitic inductance, thereby minimizing ripple voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a conventional multilayer capacitor design is used, then the device structure is simple, but high frequency noise and EMI are generated due to low ESR and parasitic inductance
Solution Approach 1:
The capacitor body is divided into multiple capacitance forming regions with different thicknesses (first capacitance forming region with greater thickness, second capacitance forming region with lesser thickness). This segmentation creates different ESR characteristics in different regions, allowing the capacitor to reduce high frequency noise and EMI while maintaining a relatively simple overall structure.
Solution Approach 2:
Dummy electrodes are disposed in the connection region at locations approaching the first capacitance forming region. This local modification increases the parasitic inductance specifically in the connection region, which helps reduce high frequency noise and EMI without requiring a complete redesign of the entire capacitor structure.
2Object-affected harmful factors
If the capacitor body is made thicker to reduce ripple voltage, then the ripple voltage is reduced, but the device size increases
Solution Approach 1:
The capacitor body is segmented into regions of different thicknesses. The first capacitance forming region has a greater thickness to reduce ripple voltage, while the second capacitance forming region has a lesser thickness to control overall device size. This segmentation allows the capacitor to reduce ripple voltage without proportionally increasing the entire device volume.
Solution Approach 2:
The thicker first capacitance forming region is strategically positioned to address the ripple voltage issue locally, while the rest of the capacitor body maintains a more compact structure. This localized approach to thickness variation reduces ripple voltage without requiring the entire capacitor to be thicker.
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 multilayer capacitor effectively reduces high frequency noise and EMI, preventing communication and sound quality issues in portable devices by minimizing ripple voltage and enhancing ESR characteristics.
Implementation Method 1
increasing ESR and parasitic inductance, thereby minimizing ripple voltage
Implementation Method 2
a first capacitance forming region and a second capacitance forming region disposed to face each other
Data Source
AI summary
A multilayer capacitor includes a capacitor body including a first capacitance forming region and a second capacitance forming region disposed to face each other with a connection region of a predetermined thickness in which an internal electrode is not formed disposed therebetween, a thickness of the first capacitance forming region being greater than a thickness of the second capacitance forming region. The first capacitance forming region includes first and second internal electrodes. The second capacitance forming region includes a third and fourth internal electrodes. The connection region includes at least one dummy electrode disposed to have a shorter average distance to the first capacitance forming region than to the second capacitance forming region.