Polyimide Precursor Resin Composition for Flexible Device Substrates
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Solution Overview
Problem
Existing polyimide films used for flexible device substrates suffer from low adhesion to carrier substrates, peeling issues, and lack of stability at high temperatures, which impairs the reliability of flexible devices.
Innovation Solution
A polyimide precursor resin composition is developed, comprising a polyamic acid with a specific molecular structure obtained from a tetracarboxylic acid component, a diamine component, and a carboxylic acid monoanhydride, which satisfies specific molar ratios to enhance peel strength and viscosity stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional polyimide films are used for flexible device substrates, then weight reduction and flexibility are achieved, but adhesion to carrier substrates is insufficient causing peeling
Solution Approach 1:
The invention changes the chemical composition parameters of the polyimide precursor by incorporating specific carboxylic acid groups and controlling the molar ratios of tetracarboxylic acid dianhydride, diamine, and carboxylic acid monoanhydride components. This chemical parameter modification enables the polyimide film to form strong chemical bonds with the carrier substrate, resolving the adhesion strength versus peeling resistance contradiction.
Solution Approach 2:
The invention creates a composite polyimide system by combining multiple components (tetracarboxylic acid dianhydride, diamine, and carboxylic acid monoanhydride) in specific ratios. This composite approach integrates both the flexibility characteristics of polyimide and the adhesion properties provided by carboxylic acid groups, achieving simultaneous improvement in adhesion strength and peeling resistance.
2Weight of moving object
If polyimide films are made thinner to reduce weight, then flexibility improves, but mechanical strength becomes insufficient
Solution Approach 1:
The invention modifies the molecular structure parameters of the polyimide by incorporating carboxylic acid groups and controlling the composition ratios. This changes the intermolecular forces and chain packing, resulting in enhanced mechanical strength that allows thinner film designs while maintaining structural integrity and flexibility.
3Temperature
If polyimide films are required to withstand high temperature conditions during device manufacturing, then heat resistance is improved, but adhesion stability deteriorates
Solution Approach 1:
The invention optimizes the chemical composition parameters, specifically the molar ratios of components and the content of carboxylic acid groups. This creates a polyimide structure that maintains both thermal stability for high-temperature processing and compositional stability for sustained adhesion performance under thermal conditions.
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 polyimide film produced from this composition exhibits high peel strength with respect to substrates, ensuring mechanical properties required for flexible device applications and improving the reliability of flexible devices.
Implementation Method 1
a polyimide precursor resin composition for forming a flexible device substrate, comprising a polyamic acid having a structure obtained from: a tetracarboxylic acid component comprising at least one of 3,3′,4,4′-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride, a diamine component comprising at least one of paraphenylene diamine and 4,4′-diaminodiphenyl ether, and a carboxylic acid monoanhydride
Data Source
AI summary
A polyimide precursor resin composition for forming a flexible device substrate, including a polyamic acid having a structure obtained from a tetracarboxylic acid component including at least one of 3,3′,4,4′-biphenyltetracarboxylic dianhydride and pyromellitic dianhydride, a diamine component including at least one of paraphenylene diamine and 4,4′-diaminodiphenyl ether, and a carboxylic acid monoanhydride, the polyamic acid satisfying equations (1) and (2) below:0.97≤X/Y<1.00 Equation (1)0.5≤(Z/2)/(Y−X)≤1.05 Equation (2)in which X represents a number of moles of tetracarboxylic acid component, Y represents a number of moles of diamine component, and Z represents a number of moles of the carboxylic acid monoanhydride.