Monolithic Ceramic Capacitor ESL Reduction via Segmented Arrays
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Solution Overview
Problem
Monolithic ceramic capacitors face issues with reduced capacitance due to solder joint defects and time-consuming capacitance measurement, and they struggle to maintain performance in communication and information processing devices with high signal transmission speeds and increased noise levels.
Innovation Solution
A monolithic ceramic capacitor design featuring a capacitor body with laminated ceramic layers, multiple internal and external terminal electrodes, and same-polarity-connection conductors that allow for current flow through opposing internal electrodes to cancel magnetic fields, reducing equivalent series inductance (ESL) and enabling easy measurement of overall capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple capacitor arrays are connected to a single external terminal electrode, then the overall capacitance increases, but the reliability decreases due to solder joint defects causing disconnection
Solution Approach 1:
The capacitor is divided into multiple independent capacitor arrays (first, second, third, and fourth arrays), each with its own dedicated external terminal electrodes. This segmentation ensures that a solder joint defect in one array does not affect the others, maintaining reliability while achieving high overall capacitance through parallel connection of independent units.
Solution Approach 2:
Different regions of the capacitor have specialized functions: some external terminal electrodes are dedicated to specific capacitor arrays for reliable local connections, while same-polarity-connection conductors provide additional redundancy. This local specialization ensures that each capacitor array can operate independently even if other connections fail.
2Quantity of substance
If multiple capacitor arrays are used to increase capacitance, then the overall capacitance increases, but the measurement time increases due to need to measure each array separately
Solution Approach 1:
Multiple capacitor arrays are electrically connected in parallel through shared external terminal electrodes and same-polarity-connection conductors. This merging allows the overall capacitance to be measured as a single equivalent capacitance value between two external terminal electrodes, eliminating the need to measure each array separately and significantly reducing measurement time.
3Reliability
If currents flow through capacitors in opposite directions to cancel magnetic fields, then the equivalent series inductance decreases, but the device complexity increases due to multiple internal electrodes and connections
Solution Approach 1:
Adjacent internal electrodes are arranged with opposite polarities and connected to different external terminal electrodes, creating asymmetric current paths that flow in opposite directions. This asymmetric arrangement enables magnetic field cancellation and reduces equivalent series inductance, improving noise absorption performance despite the increased number of internal electrodes.
Solution Approach 2:
Same-polarity-connection conductors connect internal electrodes of the same polarity across different capacitor arrays, creating equipotential regions. This arrangement simplifies the external terminal structure while enabling opposite-direction current flow through adjacent arrays, achieving magnetic field cancellation without proportionally increasing external connection complexity.
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 design maintains desired capacitance even with solder joint defects, simplifies capacitance measurement, and effectively reduces ESL, enhancing noise absorption and reliability in high-frequency applications.
Implementation Method 1
a current to flow in a certain direction while another potential is applied to the other capacitors to cause a current to flow in the opposite direction so that magnetic fields generated by currents flowing through two capacitors are canceled to reduce the ESL
Data Source
AI summary
A multi-terminal monolithic ceramic capacitor arranged to reduce an equivalent series inductance and having an array structure is provided. A first same-polarity-connection conductor and a second same-polarity-connection conductor are provided inside a capacitor body so as to extend over at least two capacitors. The first same-polarity-connection conductor is electrically connected to a plurality of first external terminal electrodes, and the second same-polarity-connection conductor is connected to a plurality of second external terminal electrodes. In the monolithic ceramic capacitor which is mounted on a wiring substrate, the overall capacitance can be maintained even if an accident, such as cracking of a solder joint, occurs in one of the external terminal electrodes.