Monolithic Ceramic Capacitor Solder-Repellent Electrode Vibration Isolation
Solution Overview
Problem
Monolithic ceramic capacitors generate acoustic noise due to electrostrictive vibrations when an AC voltage is applied, causing audible vibrations in circuit boards, which is a problem for various electronic devices.
Innovation Solution
A monolithic ceramic electronic component with a ceramic laminate body and outer electrodes featuring solder-repellent and solder-receivable portions, where the solder-repellent portion is coated with a solder-resistant film to prevent molten solder adhesion, reducing vibrations and noise by isolating the central portion of the capacitor from the circuit board.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the outer electrode is fully covered with solder to ensure secure mounting, then the mounting reliability is improved, but the acoustic noise increases due to vibration transmission
Solution Approach 1:
The patent applies different surface properties to different regions of the outer electrode: the central portion has a solder-resistant film for low friction and vibration isolation, while the peripheral portions have solder-wettable surfaces for secure mounting. This local differentiation resolves the contradiction between mounting reliability and noise reduction.
Solution Approach 2:
The outer electrode surface is segmented into distinct functional zones: a central solder-repellent area and peripheral solder-receivable areas. This segmentation allows the electrode to simultaneously achieve secure mounting at the periphery while isolating vibrations at the center, resolving the noise-reliability tradeoff.
2Object-generated harmful factors
If the central portion of the capacitor is isolated from the circuit board to reduce vibration transmission, then the acoustic noise is reduced, but the mounting security may be compromised
Solution Approach 1:
The mounting function is segmented from the vibration transmission path. The central portion is isolated to reduce vibrations, while peripheral soldering areas provide secure mounting. This segmentation resolves the contradiction between vibration isolation and mounting security.
Solution Approach 2:
Different regions of the outer electrode are given different properties: the central area has low-friction solder-resistant film for vibration isolation, while peripheral areas have high-adhesion solder-receivable surfaces for secure mounting. This local quality differentiation resolves the contradiction.
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 preventing molten solder from adhering to the central portion of the capacitor, minimizing vibrations transmitted to the circuit board, and allows secure mounting regardless of the capacitor's orientation.
Implementation Method 1
The outer electrode includes a solder-repellent portion to which molten solder does not adhere and a solder-receivable portion to which the molten solder does adhere
Implementation Method 2
acoustic noise occurs when an AC voltage is applied to a monolithic capacitor mounted on a circuit board due to electrostrictive vibrations of the monolithic capacitor
Data Source
AI summary
When a monolithic ceramic electronic component is viewed from either one of end surfaces thereof, an outer electrode includes a solder-repellent portion and a solder-receivable portion. The solder-repellent portion covers the central portion of an end surface of a ceramic laminate body. The solder-receivable portion includes portions disposed on two opposing sides of the solder-repellent portion. When the monolithic ceramic electronic component is mounted on the circuit board, solder does not adhere to a portion around the central portion of the end surface. Thus, expansion and contraction that occur as a result of application of an AC voltage are not significantly transmitted to the circuit board. Consequently, vibrations of the circuit board are reduced.