Polyimide Thin-Film Capacitor Structure for Higher Dielectric Constant
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Solution Overview
Problem
Existing thin film capacitors with three-layered structures, typically using plastic thin films and metal foils, have limitations in terms of temperature range, dielectric constant, and thickness, which can be improved for enhanced performance and cost-effectiveness.
Innovation Solution
A thin film capacitor with a two-layered structure comprising a dielectric layer made of polyimide with ether linkages and conductive particles, which increases the dielectric constant and reduces thickness while maintaining mechanical integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a three-layered structure with plastic thin film and metal foils is used, then the capacitor structure is stable and reliable, but the thickness is larger and the dielectric constant is limited (2-4)
Solution Approach 1:
The patent combines the dielectric layer and one electrode layer into a single integrated thin film structure. The conductive polymer layer serves dual functions as both electrode and structural component, eliminating the need for separate metal foil electrodes and reducing overall capacitor thickness while maintaining reliability.
Solution Approach 2:
The patent uses composite materials by incorporating conductive particles (metal oxides, metal flakes, or carbon particles) into the polyimide dielectric matrix. This creates a composite thin film with enhanced dielectric constant (greater than 3.5) and improved electrical properties, allowing thinner design without sacrificing performance.
2Ease of manufacture
If conventional plastic thin films (PP, PPS, PET) are used, then the manufacturing cost is low, but the working temperature range is limited (−55°C to 125°C) and dielectric constant is low (2-4)
Solution Approach 1:
The patent changes the chemical composition parameters of the dielectric material by using polyimide with specific ether linkage content (50-100 weight parts per 100 weight parts of polyimide) and controlled conductive particle content (10-70 weight parts per 100 weight parts of dielectric layer). This enables the capacitor to operate at higher temperatures (up to 200°C) while maintaining cost-effectiveness through solution processing.
Solution Approach 2:
The patent creates a composite dielectric layer combining polyimide matrix with conductive particles (metal oxides, metal flakes, or carbon particles). This composite structure achieves high dielectric constant (greater than 3.5) and extended temperature range (−55°C to 200°C) while remaining manufacturable through coating and drying processes.
3Quantity of substance
If conventional plastic thin films are used, then the dielectric constant is maintained at 2-4, but the capacitor cannot achieve higher charge storage capacity
Solution Approach 1:
The patent employs composite materials by dispersing conductive particles (metal oxides, metal flakes, or carbon particles) within the polyimide dielectric matrix. This composite structure increases the dielectric constant to greater than 3.5, enabling higher charge storage capacity while the polyimide matrix maintains dielectric stability and reliability.
Solution Approach 2:
The patent applies local quality enhancement by concentrating conductive particles within the dielectric layer to create regions of high dielectric constant. This localized enhancement of electrical properties allows the capacitor to achieve higher charge storage capacity without compromising overall dielectric stability.
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 improved thin film capacitor achieves a higher working temperature range, increased dielectric constant, and reduced thickness, along with lower dielectric loss, making it more efficient and cost-effective.
Implementation Method 1
The polyimide comprises ether linkages. Based on 100 weight parts of the polyimide, a total amount of monomer units comprising the ether linkages is 50 weight parts to 100 weight parts.
Implementation Method 2
The dielectric layer comprises polyimide and conductive particles. Based on 100 weight parts of the dielectric layer, a total amount of the conductive particles is 10 weight parts to 70 weight parts.
Data Source
AI summary
A thin film capacitor is provided. The thin film capacitor includes a dielectric layer and a conductive layer. The dielectric layer includes polyimide and conductive particles. The polyimide includes ether linkages. Based on 100 weight parts of the polyimide, a total amount of monomer units including the ether linkages is 50 weight parts to 100 weight parts. Based on 100 weight parts of the dielectric layer, a total amount of the conductive particles is 10 weight parts to 70 weight parts. The conductive layer is disposed on a surface of the dielectric layer.