Capacitor Interposer Dampens Piezoelectric Acoustic Noise
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Solution Overview
Problem
Multilayer ceramic capacitors generate acoustic noise due to piezoelectric vibrations, which can cause listener discomfort and interfere with audio output in electronic devices, especially in silent environments, where this noise is perceived as equipment malfunction.
Innovation Solution
A capacitor component design that incorporates a piezoelectric material with an interposer made of a buffer substrate having lower piezoelectricity, connected via electrodes, and optionally encapsulated with a molding part and an electrode sheet, to reduce acoustic noise by mitigating the vibrational effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a multilayer ceramic capacitor uses a piezoelectric material in the dielectric layers, then high capacitance and compact size are achieved, but acoustic noise is generated due to piezoelectric vibrations
Solution Approach 1:
A damping layer is introduced as an intermediary between the capacitor body and the printed circuit board. This damping layer absorbs the piezoelectric vibrations generated by the capacitor, preventing them from being transmitted to the PCB and causing acoustic noise. The damping layer acts as a mediator that decouples the vibration source from the structure that amplifies it.
Solution Approach 2:
The piezoelectric material's vibration-generating property is converted into a beneficial effect by using the damping layer to absorb and dissipate the vibrational energy. The harmful vibrations are transformed into heat energy within the damping material, converting a detrimental effect into a harmless energy dissipation process.
2Ease of manufacture
If the capacitor is directly mounted on the printed circuit board, then ease of mounting is improved, but the entire PCB becomes an acoustic reflective surface amplifying the noise
Solution Approach 1:
The damping layer serves as an intermediary mounting element between the capacitor and the PCB. It provides a mounting interface while simultaneously absorbing vibrations, preventing the PCB from acting as an acoustic reflective surface. This intermediary layer decouples the mechanical connection from the acoustic coupling.
3Object-generated harmful factors
If acoustic noise reduction measures are added to the capacitor structure, then acoustic noise is reduced, but device complexity increases
Solution Approach 1:
The capacitor component is segmented into distinct functional layers: the capacitor body with piezoelectric dielectric layers and a separate damping layer. This segmentation allows the noise reduction function to be added as a distinct element rather than complicating the capacitor body structure itself.
Solution Approach 2:
The solution uses composite material structure by combining the piezoelectric ceramic material with a polymer damping material. Each material performs its specialized function - the piezoelectric material provides capacitance while the polymer damping material absorbs vibrations - creating a composite component that addresses both electrical and acoustic 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
The solution effectively reduces acoustic noise by dampening the piezoelectric vibrations, improving the operational quality of electronic devices by minimizing noise interference and preventing misinterpretation of noise as equipment failure.
Implementation Method 1
the capacitor body containing a piezoelectric material disposed at least in regions between the plurality of internal electrodes
Implementation Method 2
an interposer disposed to be coupled to the capacitor and including a buffer substrate containing a buffer material having a degree of piezoelectricity lower than that of the piezoelectric material
Data Source
AI summary
A capacitor component includes a capacitor including a plurality of internal electrodes, a capacitor body containing a piezoelectric material disposed in at least regions between the plurality of internal electrodes, and external electrodes connected to the plurality of internal electrodes; and an interposer disposed to be coupled to the capacitor and including a buffer substrate containing a buffer material having a degree of piezoelectricity lower than that of the piezoelectric material, and connection electrodes electrically connected to the external electrodes.