Polyimide Film Resin Composition for Flexible Circuit Boards
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Solution Overview
Problem
Conventional colorless and transparent polyimide films are expensive, lack resistance to methyl ethyl ketone, and break under tensile force, making them unsuitable for applications like flexible printed circuit boards.
Innovation Solution
A polyimide film composed of specific resins derived from biphenyltetracarboxylic acid, 2,2-bis[3,4-(dicarboxyphenoxy)phenyl]propane, 4,4'-oxydiphthalic acid, 2,2'-bis(trifluoromethyl)benzidine, 3,3'-diaminodiphenylsulfone, and 4,4'-diaminodiphenylsulfone, formulated with a polar organic solvent, offering improved heat resistance, transparency, and strength while being more resistant to methyl ethyl ketone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional colorless and transparent polyimide films are used, then transparency and heat resistance are achieved, but cost is high and resistance to methyl ethyl ketone is low
Solution Approach 1:
The patent changes the chemical composition parameters of the polyimide resin by incorporating specific diamine components (3,3'-diaminodiphenylsulfone and 4,4'-diaminodiphenylsulfone) in controlled ratios. This compositional parameter change achieves both high methyl ethyl ketone resistance and cost-effectiveness, resolving the contradiction between reliability and manufacturing cost.
Solution Approach 2:
The patent creates a composite polyimide resin system combining multiple dianhydride components (BPDA, BPADA, ODPA) and diamine components (TFMB, 3,3'-DDS, 4,4'-DDS) in specific ratios. This composite material approach achieves superior methyl ethyl ketone resistance while maintaining cost efficiency, addressing the contradiction between reliability and ease of manufacture.
2Strength
If conventional colorless and transparent polyimide films are used, then transparency is achieved, but strength under tensile force is low and the film breaks
Solution Approach 1:
The patent optimizes the molecular structure parameters of the polyimide resin by controlling the ratio of rigid diamine components (3,3'-DDS and 4,4'-DDS) to achieve high tensile strength while maintaining transparency. The specific compositional parameters enable the film to withstand tensile forces without breaking while preserving optical clarity.
3Reliability
If polyimide films are subjected to severe heat history, then film formation is achieved, but the film becomes opaque or colored yellow/brown
Solution Approach 1:
The patent develops a composite polyimide resin system incorporating BPDA, BPADA, and ODPA dianhydrides with TFMB, 3,3'-DDS, and 4,4'-DDS diamines. This composite structure provides both excellent heat resistance and maintains colorlessness and transparency after severe heat treatment, resolving the contradiction between thermal stability and optical properties.
Data Source
AI summary
[Problem to be solved] An object of the present invention is to provide a colorless and transparent polyimide film which exhibits excellent heat resistance, transparency and strength equivalent to those of the conventional colorless and transparent polyimide film, can be produced at a lower cost than the conventional colorless and transparent polyimide film, and is more resistant to methyl ethyl ketone than the conventional colorless and transparent polyimide film. [Means to solve problem] The colorless and transparent polyimide film according to the present invention is made from a specific polyimide resin. The specific polyimide resins consist of a site derived from BPDA, at least one site selected from the group consisting of a site derived from BPADA and a site derived from ODPA, a site derived from TFMB, and at least one site selected from the group consisting of a site derived from 3,3'-DDS and a site derived from 4,4'-DDS. The haze value of the polyimide film is in the range of 0.1 or more and 2.0 or less.