High-Density Capacitors Using Porous AAO Dielectrics
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional capacitors, such as trench, multilayer ceramic, and tantalum capacitors, fail to meet the demands of emerging applications for high-density capacitors with high volumetric efficiency and silicon compatibility, due to limitations in capacitance density, volumetric efficiency, and compatibility with silicon-based implementations.
Innovation Solution
A high-density capacitor system comprising a substrate with a porous conductive layer formed in a predetermined pattern, a dielectric material, and a second conductive layer, along with conductive pads, enabling independent terminal connections and integration with silicon stack packages, utilizing nanoelectrode particulate and a conformal dielectric for enhanced surface area and energy storage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional trench capacitors are used to increase capacitance density, then capacitance density can reach 2-40 μF/cm2, but volumetric efficiency remains insufficient and device thickness increases
Solution Approach 1:
The patent employs a porous anodic aluminum oxide (AAO) layer as the dielectric material, which provides a highly porous structure with controlled pore sizes and distributions. This porous structure dramatically increases the effective surface area for capacitance storage while maintaining a thin overall device profile, thereby achieving high capacitance density without proportionally increasing device volume. The porous structure enables capacitance densities exceeding 100 μF/cm2 while keeping the device thickness manageable.
Solution Approach 2:
The patent transitions from planar capacitor structures to three-dimensional porous structures by utilizing vertically oriented pores in the AAO layer. This dimensional transformation allows the capacitor to store charge throughout the volume of the porous structure rather than only at the surface, effectively adding a vertical dimension to the capacitance storage mechanism and dramatically improving volumetric efficiency.
2Quantity of substance
If multilayer ceramic capacitors are used to achieve high capacitance density, then capacitance density can reach around 60 μF/cm2, but the fabrication process is highly complex and not silicon compatible
Solution Approach 1:
The patent changes the material parameters by using aluminum oxide as the dielectric material instead of ceramic materials, and employs anodization to form the dielectric layer instead of high-temperature sintering processes. This parameter change enables compatibility with silicon-based substrates and simplifies the fabrication process while achieving capacitance densities exceeding 100 μF/cm2 through the porous structure.
Solution Approach 2:
The patent replaces the mechanical sintering process used in multilayer ceramic capacitor fabrication with a chemical anodization process. This substitution eliminates the need for high-temperature processing and complex layer stacking operations, thereby simplifying the fabrication process and enabling silicon compatibility while maintaining high capacitance density through the porous AAO structure.
3Quantity of substance
If tantalum capacitors are used to achieve high capacitance density, then capacitance density can reach up to 40 μF/cm2, but they are not silicon compatible and require high-temperature sintering
Solution Approach 1:
The patent changes the material composition from tantalum to aluminum, and changes the processing temperature regime from high-temperature sintering to low-temperature anodization. This parameter change enables silicon compatibility by avoiding high-temperature processes that would damage silicon substrates, while achieving superior capacitance densities exceeding 100 μF/cm2 through the porous AAO structure.
4Quantity of substance
If dielectric layer thickness is reduced to increase capacitance density, then capacitance density increases, but manufacturing precision requirements increase
Solution Approach 1:
The patent uses a porous AAO dielectric layer where the capacitance is distributed throughout the porous volume rather than concentrated in a thin non-porous layer. This allows achieving high capacitance density with a thicker overall dielectric structure, thereby reducing the manufacturing precision requirements for thickness control while maintaining high capacitance values.
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 solution provides significantly increased capacitance density and volumetric efficiency, enabling miniaturized capacitors suitable for biomedical applications and other high-current demands, with improved reliability and compatibility with silicon-based systems.
Implementation Method 1
a porous conductive layer formed on the substrate, wherein the porous conductive layer is formed in accordance with a predetermined pattern
Implementation Method 2
a dielectric material formed on the porous conductive layer
Data Source
AI summary
The present invention describes systems and methods for providing high-density capacitors. An exemplary embodiment of the present invention provides a high-density capacitor system comprising a substrate and a porous conductive layer formed on the substrate, wherein the porous conductive layer is formed in accordance with a predetermined pattern. Furthermore, the high-density capacitor system includes a dielectric material formed on the porous conductive layer and a second conductive layer formed on the dielectric material. Additionally, the high-density capacitor system includes a plurality of conductive pads configured in communication with the second conductive layer.