Solid Electrolytic Capacitor Anode Lead Crack Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solid electrolytic capacitors experience cracks at the anode lead interface, leading to increased leakage current due to the transition from cylindrical to quadrangular prism anode leads, which complicates downsizing and weight reduction in electronic devices.
Innovation Solution
Controlling the bulk density of valve action metal powder to maintain an average particle diameter of 0.43 μm or smaller during vacuum sintering of the anode body, and optimizing the anode lead and body dimensions to ensure a ratio of Wa/Wb ≤ 0.50, along with a track-like or quadrangular cross-section form, prevents cracks and reduces leakage current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the anode lead is changed from cylindrical to quadrangular prism form to lower the profile, then the profile of the solid electrolytic capacitor is reduced, but cracks occur on the planting surface of the anode body, increasing leakage current
Solution Approach 1:
The invention changes the physical parameters of the valve action metal powder, specifically controlling the average particle diameter to 0.43 μm or smaller and bulk density to 4.5 g/cm³ or larger. This parameter optimization ensures that during vacuum sintering, the anode body forms with adequate strength and proper bonding to the quadrangular anode lead, preventing cracks while maintaining the lowered profile design.
2Length of stationary object
If the anode lead is changed from cylindrical to quadrangular prism form to lower the profile, then the profile of the solid electrolytic capacitor is reduced, but the manufacturing complexity increases due to crack prevention requirements
Solution Approach 1:
The invention establishes specific parameter ranges for the valve action metal powder (average particle diameter ≤0.43 μm, bulk density ≥4.5 g/cm³) that simplify the manufacturing process. By controlling these parameters, the vacuum sintering process naturally produces crack-free anode bodies with quadrangular anode leads, eliminating the need for complex additional processing steps or quality control measures.
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 approach effectively prevents cracks on the anode body and minimizes leakage current, enhancing the reliability and performance of solid electrolytic capacitors while supporting device miniaturization.
Implementation Method 1
the anode body 2 which became a sintered body of the valve action metal by vacuum sintering of a compact of valve action metal powder
Implementation Method 2
a dielectric oxide film 3, a cathode layer 4, and a cathode lead-out layer 5, on a peripheral surface of the anode body 2
Data Source
AI summary
The solid electrolytic capacitor according to the present invention comprises a capacitor element including an anode section, a cathode section, and a dielectric oxide film provided between the anode section and the cathode section. The solid electrolytic capacitor further comprises an anode lead frame connected to the anode section, a cathode lead frame connected to the cathode section, and an exterior resin covering the capacitor element and a part of the anode lead frame and cathode lead frame respectively. The anode section comprises an anode body including a sintered body of a valve action metal, and an average particle diameter of particles of the valve action metal of the anode body is 0.43 μm or smaller.