Multilayer Ceramic Capacitor Squeal Suppression via Electrode Geometry
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multilayer ceramic capacitors experience 'squeal' noise due to electric-field-induced distortion, which is difficult to suppress without affecting the dielectric material composition or using complex processes, and the design freedom is limited in current solutions.
Innovation Solution
The configuration of internal electrodes is modified to include low-activity regions near the end edges of the capacitor body, with a facing area less than one fifth of normal regions, reducing electric-field-induced distortion and substrate vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the facing area of internal electrodes in low-activity regions is reduced to less than one fifth of normal regions, then electric-field-induced distortion and substrate vibration are suppressed, but capacitance performance may be reduced
Solution Approach 1:
The patent applies local quality by creating low-activity regions with reduced facing area (less than one fifth of normal regions) at specific locations near end edges of the capacitor body, while maintaining normal facing area in other regions. This localized modification suppresses electric-field-induced distortion and substrate vibration at critical areas without significantly reducing overall capacitance performance, as the reduced regions are positioned where their contribution to total capacitance is minimal.
2Ease of manufacture
If conventional dielectric compositions are used, then manufacturing is simple, but squeal noise occurs due to electric-field-induced distortion
Solution Approach 1:
Instead of modifying the dielectric composition throughout the entire capacitor, the patent applies local quality by reducing the facing area of internal electrodes only in low-activity regions near the end edges. This localized structural modification effectively suppresses squeal noise and substrate vibration while maintaining the simplicity of conventional manufacturing processes and dielectric compositions.
3Force
If low-activity regions are positioned in cylindrical regions with radius 0.025L about end edges, then substrate bending forces are reduced, but device complexity increases
Solution Approach 1:
The patent defines low-activity regions using a clear geometric criterion: cylindrical regions with radius 0.025L (where L is the distance between end surfaces) centered at end edges of the capacitor body. Within these defined regions, the facing area of internal electrodes is reduced to less than one fifth of normal regions. This systematic local modification effectively reduces substrate bending forces while maintaining reasonable manufacturing complexity through a well-defined geometric pattern.
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 configuration effectively suppresses 'squeal' noise while maintaining capacitance performance and simplifying the mounting process by reducing substrate bending forces, without requiring additional components or complex processes.
Implementation Method 1
When a voltage is applied across the first and second external electrodes 11 and 12 of the multilayer ceramic capacitor 1, dielectric polarization occurs at positions where adjacent internal electrodes 3a and 3b face each other. This makes it possible to obtain capacitances as described above.
Implementation Method 2
dielectrics provided by the dielectric ceramic layers 2 and located in the active part 15 cause electric-field-induced distortions depending on the applied voltage, as indicated by arrows 16 of FIG. 15. This causes the multilayer ceramic capacitor 1 to be deformed as indicated by dashed lines in FIG. 15.
Implementation Method 3
When an alternating voltage is applied to the multilayer ceramic capacitor 1, deformation of the multilayer ceramic capacitor 1 resulting from electric-field-induced distortion causes the substrate 13 to vibrate and produces a sound called a 'squeal'.
Data Source
AI summary
The “squeal” that occurs when an electric field is applied to a multilayer ceramic capacitor mounted on a substrate is suppressed by providing in an active part contributing to formation of capacitances between internal electrodes facing each other in a capacitor body, low-activity regions positioned near respective end edges of respective external electrodes. A facing area of the internal electrodes in the low-activity regions is less than or equal to one fifth that of the internal electrodes in a normal region having the same volume as that of the low-activity regions. This makes it possible to suppress occurrence of electric-field-induced distortion near the external electrodes bonded to a substrate and reduce the force that causes the substrate to bend.