Multilayer Capacitor Gas-Filled Space Absorbs Piezoelectric Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Multilayer capacitors generate significant acoustic noise due to piezoelectric vibrations, which can be uncomfortable for users, especially as noise reduction in electronic devices has led to this noise becoming more prominent.
Innovation Solution
A multilayer capacitor design featuring a capacitor body with a space portion containing a gas, where the length of the space portion is between 0.5 and 0.85 times the length of the capacitor body, and a thickness of 15 μm to 30 μm, to absorb piezoelectric vibrations, and external electrodes connected to internal electrodes, reducing acoustic noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a multilayer capacitor is designed with conventional solid cover regions, then structural strength and reliability are maintained, but piezoelectric vibrations are transmitted to the circuit board causing acoustic noise
Solution Approach 1:
The patent introduces a gas-filled space portion as an intermediary between the dielectric layer and the lower cover region. This gas-filled space acts as a vibration isolation layer that absorbs piezoelectric vibrations generated in the dielectric layer, preventing them from being transmitted to the lower cover region and subsequently to the circuit board. The gas-filled space serves as a mediator that decouples the vibration transmission path while maintaining the structural integrity and reliability of the capacitor.
Solution Approach 2:
The patent utilizes the compressible nature of gas in the space portion to absorb mechanical vibrations. The gas-filled space portion functions as a pneumatic cushion that can elastically deform under vibration stress, thereby absorbing the piezoelectric vibrations generated in the dielectric layer. This pneumatic cushioning effect reduces the transmission of vibrations to the lower cover region and circuit board, effectively decreasing acoustic noise while maintaining capacitor reliability.
2Object-affected harmful factors
If the space portion thickness is increased to improve vibration absorption, then acoustic noise decreases, but the capacitor body becomes more vulnerable to external stress
Solution Approach 1:
The patent optimizes the thickness of the space portion within a specific range (15 μm to 30 μm) to achieve the best balance between vibration absorption and structural strength. By carefully controlling this parameter, the gas-filled space provides sufficient vibration isolation to reduce acoustic noise while maintaining the mechanical strength and stress resistance of the capacitor body. This parameter optimization ensures that the space portion is thick enough to absorb vibrations effectively but not so thick as to compromise structural integrity.
3Object-affected harmful factors
If the space portion length ratio is increased to enhance vibration absorption, then acoustic noise decreases, but the active region area available for capacitance is reduced
Solution Approach 1:
The patent optimizes the length ratio of the space portion to the capacitor body length within the range of 0.05 to 0.85 to achieve the optimal balance between vibration absorption and capacitance. By controlling this ratio, the gas-filled space provides sufficient vibration isolation to reduce acoustic noise while preserving enough active region area to maintain the required capacitance value. This parameter optimization ensures that the space portion is long enough to absorb vibrations effectively but not so long as to excessively reduce the capacitance-forming area.
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 decreases acoustic noise to acceptable levels while maintaining the reliability of the capacitor by absorbing vibrations and preventing cracks, with a preferable ratio of space portion length to capacitor body length between 0.5 and 0.85, and a thickness that optimally absorbs noise without increasing product vulnerability.
Implementation Method 1
a space portion (140) formed in the lower cover region (113)... the vibrations generated in the multilayer capacitor may be decreased to further decrease the acoustic noise generated in the circuit board due to the vibrations
Data Source
AI summary
A multilayer capacitor includes: a capacitor body including an active region including a plurality of first and second internal electrodes alternately exposed, respectively, through opposite end surfaces of the capacitor body in a length direction, and upper and lower cover regions disposed on upper and lower surfaces of the active region, respectively; and first and second external electrodes formed on the opposite end surfaces of the capacitor body in the length direction, respectively. The lower cover region of the capacitor body may have a space portion.