Multilayer Ceramic Capacitor Via Flange Structure Against Delamination
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Solution Overview
Problem
Existing multilayer ceramic capacitors experience delamination and electrostatic capacitance degradation due to stress differences between via conductors and terminal electrodes during manufacturing, leading to broken connections and reduced capacitance.
Innovation Solution
The capacitors are designed with via conductors having one end reaching the surface of a protective portion and the other end inside, featuring a flange that extends outward, preventing delamination and maintaining electrical connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If via conductors are made thin to reduce component size, then the component thickness is reduced, but delamination occurs at the interface between via conductors and internal electrodes due to stress differences
Solution Approach 1:
The flange is formed in advance at the end of the via conductor before final assembly, creating a preventive structure that stops delamination before it occurs. The flange extends outward from the via conductor axis and contacts the internal electrode, providing preliminary mechanical support and stress distribution.
Solution Approach 2:
The solution transitions from a one-dimensional via conductor (vertical connection) to a two-dimensional structure by adding the flange that extends radially outward. This dimensional change allows the via conductor to provide both vertical electrical connection and radial mechanical support, simultaneously achieving thin profile and high reliability.
2Reliability
If via conductors are made with larger diameter to prevent delamination, then connection reliability is improved, but the component thickness increases
Solution Approach 1:
The via conductor structure is segmented into two functional parts: a thin vertical shaft for electrical connection and a horizontal flange for mechanical support. This segmentation allows each part to be optimized independently - the shaft remains thin for low profile while the flange provides delamination prevention.
Solution Approach 2:
Instead of increasing the via conductor diameter in the vertical dimension (which would increase thickness), the mechanical support function is moved to the horizontal dimension through the flange. This dimensional redistribution maintains thin profile while achieving high reliability.
3Reliability
If stress is reduced during firing to prevent delamination, then connection reliability is improved, but manufacturing precision decreases
Solution Approach 1:
The flange acts as a cushioning structure that is already in place before stress occurs during firing. It provides a mechanical buffer that absorbs and distributes stress, preventing delamination even when firing stress varies. This allows normal firing precision to be maintained while still protecting against delamination.
Data Source
AI summary
One aspect of the present invention is a multilayer ceramic capacitor, including: a cuboid element body having a stack formed with alternating ceramic layers and internal electrodes made primarily of metal, a protective portion covering a surface of the stack, and a plurality of via conductors arranged so as to pass through the ceramic layers in the stacking direction of the stack, electrically connected to the internal electrodes, and having one end reaching the surface of the protective portion while the other end is positioned in the protective portion, and a plurality of terminal electrodes arranged on the surface of the element body and electrically connected to the end of each via conductor reaching the surface of the protective portion, wherein the ends of the via conductors positioned in the protective portion form a flange that extends outwardly relative to the axis of the via conductor.