Embedded Multilayer Ceramic Capacitor Electrode Geometry for Laser Processing
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Solution Overview
Problem
Multilayer ceramic capacitors embedded in boards face damage during laser processing due to absorption and non-uniform plating, leading to delamination and reduced high-temperature reliability, as existing methods struggle to maintain a uniform and flat external electrode thickness without compromising ceramic integrity.
Innovation Solution
A multilayer ceramic capacitor design with specific dimensions for external electrodes and plating layers, where the distance ratio B/A ≥ 0.6 and the angle θ between lines PQ and PR is ≤ 35 degrees, along with controlled air blowing to adjust surface flatness and angles, ensures minimal damage and delamination during embedding and plating processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the plating layer is made thick to prevent laser beam absorption damage, then the ceramic body is protected from damage, but the via hole plating becomes non-uniform causing cracking in via electrode
Solution Approach 1:
The patent changes the geometric parameters of the external electrode (making it gradually thinner toward the distal end) to control the laser beam interaction. This parameter modification allows the laser to penetrate uniformly through the plating layer without causing non-uniform plating or cracking, while still protecting the ceramic body from damage.
Solution Approach 2:
The external electrode is designed with non-uniform thickness - thicker at the base and gradually thinner toward the distal end. This local quality variation ensures that the laser beam interacts differently at different locations, preventing both ceramic damage and via hole cracking while maintaining reliable electrical connection.
2Reliability
If the external electrode thickness is decreased to reduce delamination, then the step between ceramic body and external electrode is reduced, but the laser beam may directly damage the ceramic body
Solution Approach 1:
The patent modifies the thickness parameter of the external electrode to create a gradual transition from thick to thin toward the distal end. This parameter change allows the electrode to be thin enough to prevent delamination while still providing sufficient material to protect the ceramic body from direct laser damage.
Solution Approach 2:
The external electrode thickness is made dynamic rather than uniform - it varies continuously from the base to the distal end. This dynamic structure adapts to the dual requirements of preventing delamination (by being thin at the edge) and protecting the ceramic (by being thick at the base).
3Ease of manufacture
If the external electrode has non-uniform thickness and non-flat surface, then the manufacturing process is simpler, but scattered laser beam reflections damage the resin portion and cause via electrode cracking
Solution Approach 1:
The patent carefully controls the thickness parameter of the external electrode to create a specific gradual thinning profile. This controlled parameter change produces predictable laser reflection patterns that do not damage the resin or cause via electrode cracking, while still being manufacturable.
Solution Approach 2:
The patent replaces the need for complex mechanical surface finishing processes with a controlled deposition process that inherently creates the desired gradual thickness profile. This substitution achieves both ease of manufacture and reliability without requiring additional mechanical processing steps.
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 design effectively prevents ceramic body damage and delamination, maintaining high reliability and flatness of the external electrodes, reducing cracking and delamination risks, while ensuring efficient high-frequency current supply to application processors.
Implementation Method 1
the laser beam may be absorbed due to a glass component in the external electrode while penetrating through a plating layer of the multilayer ceramic capacitor, thereby directly damaging a ceramic body
Implementation Method 2
the via hole is filled with copper by the plating process so that an external wiring and the external electrode of the multilayer ceramic capacitor are electrically connected to each other
Data Source
AI summary
There is provided a multilayer ceramic capacitor to be embedded in a board, including: a ceramic body; first and second internal electrodes alternately exposed through end surfaces of the ceramic body; first and second external electrodes formed on end surfaces of the ceramic body; and first and second plating layers enclosing the first and second external electrodes, wherein when distance from one end of bands of the first or second external electrode to the other end thereof is ‘A’ and distance between points at which a virtual line drawn from a point vertically spaced apart from a surface of the first or second plating layer at a point ½×A from one end of the bands inwardly of the ceramic body by 3 μm in length direction of the ceramic body intersects points on the surface of the first or second plating layer is ‘B,’ B/A≧0.6.