Adhesive-Free Flexible Flat Cable for Lower Insertion Loss
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Solution Overview
Problem
Flexible flat cables (FFCs) face signal attenuation due to adhesive layers with poor electrical properties, which affect insertion loss and characteristic impedance, especially during high-frequency signal transmission.
Innovation Solution
The use of surface-modified polypropylene (PP) layers as insulation, which eliminates the need for secondary processing adhesives by enhancing adhesibility, allowing for direct thermal pressing of layers without additional adhesives, thereby improving electrical characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive layers are used to laminate insulation layers and shielding layers, then the layers can be effectively bonded together, but the electrical characteristics deteriorate due to higher dielectric constant and dielectric loss values causing signal attenuation
Solution Approach 1:
The patent removes the adhesive layer from the cable structure entirely. Instead of using separate adhesive layers to bond the insulation layers and shielding layers, the invention uses the insulation layer material itself (modified with surface treatment) to provide both insulation and adhesion functions, thereby eliminating the harmful dielectric properties of adhesive materials.
Solution Approach 2:
The insulation layer is designed to perform multiple functions simultaneously: electrical insulation, mechanical bonding (adhesion), and structural support. By modifying the surface of the insulation layer to enhance adhesibility, the patent makes a single component serve multiple purposes that were previously required separate layers.
2Stability of the object's composition
If multiple layers including adhesive layers are used to construct the cable, then the structural integrity is maintained, but the insertion loss increases due to excessive signal attenuation
Solution Approach 1:
The patent extracts and removes the adhesive layer from the multi-layer construction, reducing the total number of layers from 4 or 5 to just 3 layers (conductors, insulation, shielding). This elimination of unnecessary layers directly reduces signal attenuation and insertion loss while maintaining structural integrity through the modified insulation material.
3Reliability
If high-quality insulation materials like UHMW-PE are used, then the electrical characteristics improve, but the manufacturing cost increases significantly
Solution Approach 1:
The patent changes the surface parameters of a more cost-effective insulation material (such as polypropylene or PET) through surface modification treatments. This allows the use of cheaper base materials while achieving the required electrical and adhesive properties that would otherwise require expensive materials like UHMW-PE.
Solution Approach 2:
The invention creates a composite structure by combining the insulation material with surface modifications (such as plasma treatment, corona discharge, or chemical coatings). This composite approach provides the electrical properties of high-quality materials with the cost benefits of more economical base materials.
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
This approach results in better electrical characteristics, including reduced insertion loss and stable characteristic impedance, comparable to or exceeding those of high-quality insulation materials like Ultra High Molecular Weight Polyethylene (UHMW-PE), while simplifying the manufacturing process and reducing costs.
Implementation Method 1
at least one of the inner surfaces of the two insulation layers is modified to comprise a modified surface layer possessing adhesibility
Implementation Method 2
direct thermal pressing of layers without additional adhesives
Data Source
AI summary
Provided is a flexible flat cable with no secondary processing adhesives. The flexible flat cable with no secondary processing adhesives includes a plurality of parallel arranged conductors, two insulation layers and two shielding layers. The two insulation layers have respective inner surfaces oppositely positioned to be adhered to sandwich the parallel arranged conductors. The two shielding layers are respectively adhered on respective outer surfaces of the two insulation layers. At least one of the inner surfaces or at least one of the outer surfaces of the two insulation layers is modified to have a modified surface layer possessing adhesibility.