Multiple Anode Leads and Carrier Wire for Low ESR Capacitors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solid electrolytic capacitors face challenges in achieving ultralow equivalent series resistance (ESR) due to the small particle size of tantalum particles, which decreases the volumetric contact between the anode body and the anode lead, leading to increased resistance and energy requirements for electrical connection.
Innovation Solution
The use of two or more anode leads embedded within the anode body, combined with a carrier wire arrangement where the carrier wire has a smaller diameter than the anode leads, reduces ESR and internal resistance, while also minimizing the energy needed for electrical connection by utilizing a carrier wire with a smaller diameter than the anode leads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the diameter of the anode lead is increased to decrease ESR, then the points of contact between the anode body and anode lead increase, but the internal resistance in the anode lead increases
Solution Approach 1:
The anode lead system is segmented into multiple leads (first anode lead and second anode lead) embedded within the anode body, each providing separate contact paths. This segmentation increases the total contact area with the anode body while keeping individual lead diameters small, thus reducing ESR without significantly increasing internal resistance of each lead.
Solution Approach 2:
A carrier wire is introduced as an intermediary component to electrically connect the external portions of the first and second anode leads to the anode termination. The carrier wire has a smaller diameter than the anode leads, which reduces the internal resistance of the connection path while still effectively collecting current from multiple anode leads.
2Reliability
If the diameter of the anode lead is increased to decrease ESR, then the points of contact increase, but the energy required to weld the anode lead to anode termination increases
Solution Approach 1:
The carrier wire serves as a mediator between the anode leads and the anode termination. By using a carrier wire with smaller diameter than the anode leads, the welding process requires less energy because the smaller wire presents lower thermal mass and resistance to the welding current, while still maintaining effective electrical connection.
3Volume of stationary object
If small particle size tantalum particles are used, then the anode body can be compact, but the volumetric contact between anode body and anode lead decreases
Solution Approach 1:
Multiple anode leads (first and second anode leads) are embedded within the compact anode body, creating multiple contact interfaces. This segmentation approach increases the total contact area between the anode leads and the anode body particles, compensating for the small particle size and maintaining good electrical contact despite the compact volume.
Data Source
AI summary
A solid electrolytic capacitor including a capacitor element, a first anode lead, a second anode lead, and a carrier wire. The capacitor element includes a sintered, porous anode body; a dielectric layer overlying the sintered, porous anode body; and a cathode overlying the dielectric layer that includes a solid electrolyte. The first and second anode leads each have an embedded portion positioned within the anode body and an external portion extending longitudinally from a surface of the anode body in an x-direction, while the carrier wire is positioned external to the anode body. Further, a first portion of the carrier wire is connected to the external portions of the first and second anode leads, while a second portion of the carrier wire extends longitudinally away from the surface of the anode body in the x-direction. Such an arrangement reduces the ESR and leakage current of the capacitor.