Conductive Film Primer Layer Isotropic Crack Network
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Solution Overview
Problem
Conductive foils produced using a washable coating on polyethylene terephthalate (PET) substrates exhibit anisotropy in crack formation and heat distribution, and the manufacturing process is challenging to adapt to other substrates like polycarbonate (PC), polymethyl methacrylate (PMMA), and glass, requiring individual recipe development for each material.
Innovation Solution
A conductive sheet with a primer layer and a dense, connected conductive structure formed by a crack-forming coating that is isotropic, allowing the same material composition to be used across different substrates, featuring a binder-based primer layer and a conductive metallization with additional layers for color and gloss reduction, and an adhesive layer for uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a washable coating is applied to PET substrate to form conductive film, then a dense continuous network is achieved, but pronounced anisotropy in crack formation and heat distribution occurs
Solution Approach 1:
The patent applies a primer layer with specific composition (binder, organic solvent, and/or water) before applying the crack-forming coating. The primer layer modifies the surface properties and drying parameters of the coating, which suppresses anisotropic crack formation. This parameter change in the coating system resolves the contradiction between achieving a dense continuous network and maintaining uniform heat distribution.
2Reliability
If washable coating formulation is individually developed for each substrate, then optimal performance is achieved, but manufacturing complexity and development time increase
Solution Approach 1:
The patent introduces a universal primer layer formulation that can be used with different substrates (PET, PC, PMMA, TPU, glass) without requiring individual recipe development for each substrate. The primer layer acts as an intermediate that adapts to various substrate surfaces, enabling the same crack-forming coating composition to achieve reliable performance across multiple substrate types. This universality reduces manufacturing complexity while maintaining coating performance.
3Adaptability or versatility
If transfer of manufacturing process from PET to other substrates is attempted, then substrate versatility is improved, but process reliability decreases due to anisotropy
Solution Approach 1:
The primer layer serves as an intermediary between the substrate and the crack-forming coating. It mediates the interaction between different substrate surfaces and the coating, ensuring consistent crack formation patterns regardless of the substrate material. This intermediary layer enables reliable transfer of the manufacturing process from PET to other substrates while suppressing anisotropy and maintaining conductive film performance.
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 achieves direction-independent electrical and thermal conductivity, enabling the production of conductive films suitable for various substrates without material-specific adaptations, with improved heat distribution and optical properties.
Implementation Method 1
applying a crack-forming coating to a main surface of the substrate and drying the crack-forming coating, wherein the coating forms numerous cracks in the form of a dense, continuous network upon drying
Implementation Method 2
the conductive structure is based on a conductive metallization selected from the group consisting of copper, gold, aluminum, silver
Implementation Method 3
an additional layer on one or both sides for adjusting a defined color or reducing gloss
Implementation Method 4
an additional layer on one or both sides for adjusting a defined color or reducing gloss
Data Source
Figure 1~4
Figure 5
AI summary
The invention relates to a conductive film comprising a substrate on the main surface of which a primer layer and subsequently a substantially conductive structure in the form of a densely meshed, continuous network with a plurality of openings of different geometric shapes are formed.