Multilayer Capacitor Electrode Segmentation for ESR Control
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Solution Overview
Problem
Multilayer capacitors face a challenge in achieving high ESR (Equivalent Series Resistance) while maintaining low ESL (Equivalent Series Inductance) and ensuring good contact between internal and terminal electrodes, as existing designs often compromise on ESR to minimize ESL.
Innovation Solution
The design incorporates a laminate body with specific internal electrode configurations, including first and second internal electrodes with narrower lead portions and third and fourth internal electrodes with overlapping capacitance forming regions, positioned to ensure good contact and exposure during barrel polishing, thereby increasing ESR without increasing ESL.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the lead portion width is increased to ensure good contact between internal electrodes and terminal electrodes, then contact reliability is improved, but ESR decreases
Solution Approach 1:
The patent applies different width specifications to different lead portions based on their functional requirements. The first lead portion (connected to terminal electrode) has a smaller width (0.3-0.7 times the second lead portion width) to increase ESR, while the second lead portion (inside laminate) maintains sufficient width for reliable contact. This local differentiation resolves the contradiction by optimizing each segment's width for its specific function.
2Loss of energy
If the lead portion width is decreased to increase ESR, then energy loss is reduced, but contact reliability deteriorates
Solution Approach 1:
The lead portion is segmented into two distinct sections with different width characteristics. The first lead portion (exposed on side face) has reduced width to increase ESR, while the second lead portion (embedded in laminate) has sufficient width for contact reliability. This segmentation allows simultaneous optimization of both ESR and contact reliability by assigning different dimensional characteristics to different functional segments.
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 increases ESR while maintaining low ESL and ensuring reliable contact between internal and terminal electrodes, enhancing the capacitor's performance and preventing heat generation due to ripple current.
Implementation Method 1
opposite electric currents flow in the main electrodes of the former two types of internal electrodes and, therefore, magnetic fields caused by the electric currents cancel each other out
Data Source
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AI summary
A first internal electrode includes a first lead portion and a second lead portion. A second internal electrode includes a third lead portion and a fourth lead portion. A third internal electrode includes a main electrode portion and a fifth lead portion. A fourth internal electrode includes a main electrode portion and a sixth lead portion. A joint portion between the main electrode portion and the fifth lead portion of the third internal electrode is located between an edge on the first side face side and an edge on the second side face side in a capacitance forming region when viewed from an opposing direction of the third and fourth side faces. A joint portion between the main electrode portion and the sixth lead portion of the fourth internal electrode is located between an edge on the first side face side and an edge on the second side face side in a capacitance forming region when viewed from the opposing direction of the third and fourth side faces.