Multilayer Capacitor Terminal Electrode ESL Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing multilayer capacitors face limitations in reducing equivalent series inductance (ESL) while achieving miniaturization, as the reduction in ESL is dependent on lead width and is difficult to further minimize due to structural constraints.
Innovation Solution
The design incorporates terminal electrodes with specific wide and narrow parts, where the electric current flows opposite to the internal electrode current, reducing ESL while preventing solder bridges during mounting, and allowing for miniaturization without increasing the risk of suction failure or thermal shock damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the terminal electrodes spread throughout the entire length in the transverse direction to provide current flow opposite to internal electrode current, then ESL reduction is achieved, but solder bridges occur during mounting process
Solution Approach 1:
The terminal electrode is designed with non-uniform width, featuring a wide part and a narrow part. The wide part (with width W2) is positioned at the end connected to the internal electrode to ensure sufficient current flow opposite to the internal electrode current, achieving ESL reduction. The narrow part (with width W1) is positioned at the mounting end to prevent solder bridges during mounting. This local variation in width allows the single terminal electrode to simultaneously satisfy both requirements.
2Volume of moving object
If the multilayer capacitor is miniaturized to reduce size, then miniaturization is achieved, but solder bridges occur between terminal electrodes
Solution Approach 1:
The terminal electrode employs local quality variation through its wide part and narrow part design. The narrow part at the mounting end provides sufficient spacing between adjacent terminal electrodes to prevent solder bridges, even when the overall capacitor size is miniaturized. This allows the capacitor to achieve compact dimensions while maintaining reliable mounting characteristics.
3Reliability
If the lead width of internal electrodes is increased to reduce ESL, then ESL reduction is achieved, but device dimensions increase
Solution Approach 1:
The terminal electrode's wide part is strategically positioned to overlap with the internal electrode leads, providing the necessary current flow path for ESL reduction. The narrow part extends to the mounting end, maintaining compact overall dimensions. This localized width variation allows ESL reduction without proportionally increasing the entire device size.
Solution Approach 2:
The terminal electrode utilizes the transverse dimension (width direction) to achieve ESL reduction through the wide part, while controlling the longitudinal dimension (length direction) through the narrow part design. This dimensional strategy allows ESL optimization without excessive increase in overall device footprint.
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 reduces ESL to values less than 250 pH, allowing for a reduction in the number of capacitors used and facilitating easier mounting by ensuring sufficient space for suction, while also reducing equivalent series resistance (ESR).
Implementation Method 1
electric currents flow in opposite directions in the two types of internal electrodes, whereby magnetic fields made thereby cancel each other to reduce the equivalent series inductance
Data Source
AI summary
Each of second terminal portions of a first terminal electrode has a wide part a width of which is larger than a first lead width of lead portions in each first internal electrode, and a narrow part a width of which decreases from the wide part toward the second terminal electrode and toward the first or second side face side. In a multilayer capacitor, the wide part causes an electric current to flow in the lead portions of the first internal electrodes in a direction opposite to that of an electric current flowing in the first terminal electrode, so as to cancel magnetic field thereof each other and thereby reduce ESL, and the narrow part prevents a solder bridge from occurring between the first terminal electrode and the second terminal electrode in a work of mounting the terminal electrodes of the multilayer capacitor on a circuit board or the like.