Differential Signal Cable Shielding to Prevent Void-Induced Noise
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The generation of voids within the shield tape of differential signal transmission cables, particularly when the conductive wire diameter is reduced, leads to uneven void distribution and increased mode conversion noise, resulting in decreased signal transmission performance.
Innovation Solution
Incorporating a high softening point material layer in the press-winding tape, which maintains pressing pressure and prevents void formation by not softening during heat treatment, ensuring the shield tape remains in close contact with the insulating electric wire.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the conductive wire diameter is reduced, then the cable can achieve lower voltage operation and improved signal transmission characteristics, but voids are more likely to generate during manufacturing leading to uneven void distribution
Solution Approach 1:
The patent changes the softening point parameter of the resin material in the press-winding tape from a conventional value to a specifically higher value (softening point of 80°C or higher). This parameter change allows the resin to maintain its pressing force at higher temperatures during heat treatment, effectively suppressing void formation in the shield tape even when manufacturing precision is compromised by reduced wire diameter
Solution Approach 2:
The patent uses a composite structure consisting of the press-winding tape with high softening point resin combined with the shield tape and insulating electric wire. The resin layer and adhesive layer form a composite material system where the resin's high softening point特性 complements the adhesive's bonding function, creating a synergistic effect that prevents void formation while maintaining assembly integrity
2Object-affected harmful factors
If a shield tape is longitudinally lapped and wound around the insulating electric wire, then shielding effect is achieved, but voids are present inside the shield tape causing mode conversion noise
Solution Approach 1:
The patent introduces the press-winding tape with high softening point resin as an intermediary element between the shield tape and the outer insulation. This intermediary applies continuous pressing force to eliminate voids within the shield tape, preventing mode conversion noise while preserving the shield's external noise resistance. The resin acts as a mediator that transmits pressing force uniformly throughout the shield tape structure
Solution Approach 2:
By changing the softening point parameter of the press-winding tape resin to 80°C or higher, the patent ensures that the pressing force is maintained during heat treatment processes. This parameter change directly addresses the void formation problem in the shield tape, eliminating the source of mode conversion noise while maintaining the shielding effectiveness
3Strength
If heat treatment is applied to adhere adhesive layers, then bonding strength is improved, but resin softening causes loss of pressing pressure and void formation
Solution Approach 1:
The patent fundamentally changes the softening point parameter of the resin material from conventional values (below 80°C) to a high softening point (80°C or higher). This allows the resin to withstand the heat treatment temperature required for adhesive bonding without softening, thereby maintaining pressing pressure throughout the heat treatment process and preventing void formation
Solution Approach 2:
The high softening point resin is designed in advance to withstand the subsequent heat treatment process. By selecting a resin with sufficiently high softening point before the heat treatment step, the patent ensures that the pressing pressure is maintained during the adhesive bonding process, eliminating the need for additional process adjustments
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 effectively suppresses void generation and maintains signal transmission performance by maintaining the structural integrity and contact between the shield tape and the insulating electric wire, even at reduced cable diameters.
Implementation Method 1
The second covering layer is made of a high softening point material having a softening point that is higher than a softening point of the first resin covering layer
Data Source
AI summary
A differential signal transmission cable includes: an insulating electric wire having a pair of conductive wires and an insulating layer covering the pair of conductive wires; a shield tape wound around an outer periphery of the insulating electric wire; a first tape wound around an outer periphery of the shield tape and having a first resin covering layer; and a second tape wound around an outer periphery of the first tape and having a second covering layer. The second covering layer is made of a high softening point material having a softening point that is higher than a softening point of the first resin covering layer.