Electrolytic Capacitor Two-Step Aging for Longer Maintenance Intervals
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Aluminum electrolytic capacitors in implantable medical devices require frequent maintenance cycles due to dielectric relaxation and chemical degradation, leading to reduced battery life and increased size, which is not suitable for compact applications.
Innovation Solution
A two-step aging process involving multiple electrolyte impregnations and controlled voltage/current applications to grow a stable oxide layer on anode edges, extending maintenance intervals up to 5 years in storage and 2 years post-implantation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If conventional single electrolyte impregnation and aging process is used, then manufacturing process is simple, but capacitor maintenance is required frequently (3-6 months) due to dielectric relaxation and chemical degradation
Solution Approach 1:
The aging process is divided into multiple sequential steps with different electrolyte compositions. The first aging step uses an initial electrolyte to grow the oxide layer, followed by electrolyte replacement and a second aging step to stabilize the dielectric. This segmentation allows each step to optimize for specific functions, extending maintenance intervals without excessive overall complexity.
Solution Approach 2:
The patent changes chemical parameters of the electrolyte between aging steps. The first electrolyte contains specific concentrations of borate buffer and phosphate, while the second electrolyte has modified compositions. These parameter changes enable progressive stabilization of the oxide layer and reduction of dielectric relaxation, extending capacitor life.
2Volume of stationary object
If capacitor size is minimized for compact implantable devices, then energy density increases, but heat dissipation and electrical performance become more difficult to maintain
Solution Approach 1:
The multi-step aging process with varying electrolyte compositions optimizes the oxide layer properties to achieve high dielectric strength in minimal volume. The controlled chemical parameters during aging create a dense, stable oxide structure that maintains electrical performance reliability even in compact capacitor designs with reduced spacing between electrodes.
Solution Approach 2:
The patent uses composite electrolyte systems combining borate buffers, phosphates, and organic solvents in specific ratios. This composite approach creates a stable chemical environment that promotes formation of a robust oxide dielectric layer, enabling reliable electrical performance in miniaturized capacitors where traditional single-electrolyte systems would fail.
3Reliability
If frequent capacitor maintenance cycles are implemented, then capacitor reliability is maintained, but battery life is reduced and device size increases
Solution Approach 1:
The extended aging process performs preliminary stabilization of the oxide layer and dielectric properties before the capacitor is implanted. By pre-conditioning the capacitor with multiple electrolyte impregnations and aging steps, the device achieves long-term reliability without requiring frequent maintenance cycles during operation, thereby preserving battery life.
Solution Approach 2:
The stabilized oxide layer and dielectric structure, created through the multi-step aging process, enable the capacitor to self-maintain its electrical properties over extended periods. The capacitor becomes self-sufficient in maintaining reliability without external intervention or frequent maintenance, extending both battery life and device operational duration.
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 method reduces maintenance needs, prolongs capacitor life, and enhances battery longevity by up to a year, maintaining performance and reducing the size of implantable devices.
Implementation Method 1
impregnating an aluminum electrolytic capacitor with a first electrolyte to form a first impregnated capacitor
Implementation Method 2
aging the first impregnated capacitor using a first aging process to form a first aged capacitor
Data Source
AI summary
A method of manufacturing an electrolytic capacitor includes impregnating an electrolytic capacitor with a first electrolyte to form a first impregnated capacitor, aging the first impregnated capacitor using a first aging process to form a first aged capacitor, impregnating the first aged capacitor with a second electrolyte to form a second impregnated capacitor, and aging the second impregnated capacitor using a final aging process to form a final aged capacitor.