Polyimide Laminate Heat Resistance via High-Temperature Imidization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the production of thin-film solar cells and other applications, there is a need for a polyimide laminate with a high heat-resistant polyimide layer that suppresses thermal decomposition in the temperature range of 500°C to 650°C, while maintaining excellent properties such as heat resistance, chemical resistance, radiation resistance, electrical insulation, and mechanical stability.
Innovation Solution
A polyimide layer is formed on a substrate using a polyamic acid solution composition comprising 3,3',4,4'-biphenyltetracarboxylic dianhydride and p-phenylenediamine as the main components, with a phosphorus compound added to achieve a thickness of less than 50 µm and high heat resistance by casting and subsequent heat treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a polyimide layer is formed by conventional heat treatment methods, then the polyimide layer achieves basic heat resistance, but thermal decomposition occurs in the temperature range of 500°C to 650°C
Solution Approach 1:
The patent applies parameter changes by modifying the heat treatment temperature to 700°C or higher, which is significantly higher than conventional methods. This extreme temperature parameter change transforms the polyimide structure to achieve decomposition resistance at 500-650°C range, directly resolving the contradiction between achieving heat resistance and preventing thermal decomposition.
Solution Approach 2:
The patent uses a composite material system consisting of specific tetracarboxylic acid components (including pyromellitic dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride) and specific diamine components (including p-phenylenediamine and 4,4'-diaminodiphenyl ether). This composite material composition, when subjected to high-temperature heat treatment, creates a polyimide layer with enhanced thermal stability that suppresses decomposition in the 500-650°C range.
2Strength
If the polyimide layer thickness is increased to improve mechanical properties, then mechanical strength is enhanced, but the heat treatment time and energy consumption increase
Solution Approach 1:
The patent changes the heat treatment temperature parameter to 700°C or higher, which dramatically reduces the required heat treatment time to 1 hour or less regardless of polyimide layer thickness. This parameter change decouples the relationship between thickness and energy consumption, allowing thick layers to be processed efficiently.
3Reliability
If a polyimide layer with high heat resistance is formed to suppress thermal decomposition, then thermal stability is improved, but the manufacturing process complexity increases
Solution Approach 1:
The patent simplifies the manufacturing process by changing the heat treatment temperature to 700°C or higher, which reduces the required treatment time to 1 hour or less. This single parameter change eliminates the need for complex multi-stage heat treatment processes, achieving high thermal stability while maintaining process simplicity.
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 resulting polyimide laminate exhibits excellent heat resistance, chemical resistance, radiation resistance, and mechanical properties, with suppressed thermal decomposition in the temperature range of 500°C to 650°C, enabling its use in applications like liquid crystal displays and thin-film solar cells.
Implementation Method 1
heating and drying the resultant coating film to form a self-supporting film; peeling the self-supporting film from the substrate; and then subjecting the self-supporting film to heat treatment for imidization
Implementation Method 2
applying a polyamic acid solution... on a substrate; heating the polyamic acid solution to form a polyimide layer
Data Source
AI summary
The present invention relates to a polyimide laminate obtained by casting a polyamic acid solution composition comprising a phosphorus compound and a polyamic acid, which is obtained from a tetracarboxylic acid component comprising 3,3',4,4'-biphenyltetracarboxylic dianhydride as the main component and a diamine component comprising p-phenylenediamine as the main component, on a substrate; and then heating the polyamic acid solution composition, to form a polyimide layer having a thickness of less than 50 µm on the substrate.