Multilayer Ceramic Capacitor Electrode Ratio for Noise Reduction
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Solution Overview
Problem
Multilayer ceramic capacitors generate significant acoustic noise due to piezoelectric vibrations transferred to circuit boards through external electrodes and solder, causing user discomfort, and existing technologies have not effectively addressed this issue.
Innovation Solution
A multilayer ceramic capacitor design with external electrodes having a width-to-margin part length ratio of 3.3 or less, where the external electrodes are narrower than the ceramic body, and additional cover layers are formed on the ceramic body to reduce vibration transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the width of external electrode is increased, then the electrical connection area is improved, but the acoustic noise increases due to enhanced vibration transfer to circuit board
Solution Approach 1:
The patent applies parameter changes by optimizing the width-to-length ratio of the external electrode to a specific range (3.3 or less). This parameter optimization reduces the electrode's ability to transfer vibrations to the circuit board while maintaining adequate electrical connection area, thereby resolving the contradiction between connection area and acoustic noise generation.
2Strength
If the solder volume and height are increased, then the mechanical connection strength is improved, but the vibration transfer to circuit board is enhanced causing severe acoustic noise
Solution Approach 1:
The patent changes the geometric parameters of the external electrode (width-to-length ratio ≤3.3) to optimize the vibration transfer characteristics. This parameter modification allows the system to maintain adequate connection strength while significantly reducing the acoustic noise generated during operation.
3Object-generated harmful factors
If the external electrode width is reduced, then the acoustic noise is reduced, but the electrical connection area is decreased
Solution Approach 1:
The patent identifies and optimizes the width-to-length ratio parameter of the external electrode to a specific threshold (3.3 or less). This optimized parameter configuration achieves the dual benefit of reducing acoustic noise while maintaining sufficient electrical connection area, effectively resolving the contradiction between these two requirements.
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
This design effectively reduces acoustic noise by limiting the vibration transfer to the circuit board, resulting in a noiseless or significantly reduced noise level.
Implementation Method 1
since the dielectric layer has piezoelectricity, when direct current (DC) or alternate current (AC) voltage is applied to the multilayer ceramic capacitor, a piezoelectric phenomenon is generated between the internal electrodes, thereby generating periodic vibrations while expanding and contracting a volume of a ceramic body according to the frequency
Implementation Method 2
Such vibrations are transferred to a circuit board through an external electrode of the multilayer ceramic capacitor and a solder connecting the external electrode to the circuit board, such that the entire circuit board may become an acoustically reflective surface to generate vibration sound, noise
Data Source
AI summary
There is provided a multilayer ceramic capacitor including a ceramic body having first and second main surfaces, third and fourth end surfaces, and fifth and sixth side surfaces; a plurality of first and second internal electrodes having a dielectric layer to be alternately exposed to the third and fourth end surfaces; and first and second external electrodes formed on the end surfaces and the main surfaces and electrically connected to the first and second internal electrodes, wherein when a width of the first or second external electrode is A and a length of a margin part of the ceramic body in the length direction is B, a ratio (A/B) of the width of the first or second external electrode to the length of the margin part of the ceramic body in the length direction is 3.3 or less (A/B≦3.3).