Solid Electrolytic Capacitor Canopy ESL Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional solid electrolytic capacitors face challenges in achieving both pressure resistance and reduced Equivalent Series Inductance (ESL) in a simple structure, particularly during resin injection, which affects production cost and performance.
Innovation Solution
A solid electrolytic capacitor design featuring a laminate of anode and cathode portions covered by a resin mold with protruding terminals, where cathode portions are connected through electroconductive material and a canopy, ensuring pressure resistance and reducing ESL through mutual inductance effects, and a production method involving transfer molding for excellent heat and moisture resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If transfer molding is used to seal the capacitor elements, then heat resistance and moisture resistance are improved, but excessive pressure is exerted on the capacitor elements during resin injection
Solution Approach 1:
A support structure comprising a canopy and joints is introduced as an intermediary element between the resin mold and the capacitor elements. The canopy covers the capacitor elements and the joints extend downward to rest on the anode lead frame, creating a protective framework that distributes and bears the injection pressure, thereby preventing direct excessive pressure on the capacitor elements while still enabling transfer molding for excellent heat and moisture resistance
Solution Approach 2:
The support structure (canopy and joints) is assembled and positioned over the capacitor elements before the resin injection process begins. This preliminary placement ensures that the protective framework is already in position to withstand the upcoming pressure during transfer molding, preventing damage to the capacitor elements before the sealing process completes
2Reliability
If a multi-terminal configuration is created using separate anode and cathode lead frames, then ESL reduction is achieved, but device complexity increases
Solution Approach 1:
The support structure is designed as an integrated component where the canopy and joints form a unified framework that simultaneously serves multiple functions: it provides mechanical support during molding, establishes electrical connections for the cathode terminals, and enables the multi-terminal configuration for ESL reduction, thereby reducing overall device complexity while maintaining performance
Solution Approach 2:
The canopy and joints serve multiple functions within a single structural element: they act as a protective cover during resin injection, provide mechanical support to prevent excessive pressure on capacitor elements, establish electrical connections for cathode terminals, and enable the multi-terminal configuration for ESL reduction, thereby achieving multiple objectives with a single integrated structure
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 achieves both pressure resistance and reduced ESL in a simple structure, enabling efficient production with transfer molding, thereby enhancing the capacitor's performance and reliability.
Implementation Method 1
the cathode portions of the respective capacitor elements are electrically connected to each other through an electroconductive material
Implementation Method 2
a path of an electric current flowing from a lower layer to an upper layer of the laminate in the cathode portions of the respective capacitor elements connected through the electroconductive material is opposite to paths of electric currents flowing from the canopy through the joints to the cathode terminals, thereby achieving reduction in ESL by mutual inductance effect
Data Source
AI summary
In a solid electrolytic capacitor, a path of an electric current flowing from a lower layer to an upper layer of a laminate in cathode portions of respective capacitor elements connected through an electroconductive adhesive layer is opposite to paths of electric currents flowing from a canopy through joints to cathode terminals, thereby achieving reduction in ESL by mutual inductance effect in a simple structure. Since the solid electrolytic capacitor has the structure in which the laminate is surrounded by the canopy and joints, sufficient pressure resistance is ensured for the capacitor elements during resin injection. For this reason, a resin mold to cover the laminate can be formed by transfer molding, which ensures excellent heat resistance and moisture resistance.