Paddle Card Cable Assembly With Grounded Resin Shielding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high-speed signal transmission technologies between ASICs and optical transceivers face challenges in preventing crosstalk, especially at distances greater than 25 cm, limiting the transmission rate to 112 Gbps or more.
Innovation Solution
A high-speed transmission device comprising a substrate with a control device, connectors, and a cable assembly featuring a paddle card substrate with signal and ground electrodes, and a conductive resin cover that is electrically connected to the ground electrodes but not the signal electrodes, preventing crosstalk by avoiding contact with signal electrodes and ensuring effective grounding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If a cable is connected between ASIC and optical transceiver disposed at separated positions on substrate, then the transmission distance can be extended beyond 25 cm, but crosstalk cannot be sufficiently prevented at high speeds of 112 Gbps or more
Solution Approach 1:
A conductive resin cover is introduced as an intermediary shielding component between the signal cable and surrounding structures. This conductive resin layer acts as a mediator that redirects electromagnetic interference to ground, preventing crosstalk from affecting the high-speed signal transmission over extended distances.
Solution Approach 2:
The electrical characteristics of the resin material are modified by adding conductive fillers (such as carbon black, metal powder, or conductive polymer) to change its electrical conductivity parameter. This transformation turns an insulating material into a conductive shielding layer that can effectively manage electromagnetic interference without requiring a complete redesign of the cable assembly.
2Object-affected harmful factors
If conductive resin cover is electrically connected to signal electrodes, then shielding effectiveness may be improved, but short circuit risk increases and signal integrity deteriorates
Solution Approach 1:
The conductive resin cover is designed with spatially differentiated electrical connections: it is electrically connected to ground electrodes at specific locations to provide shielding, while deliberately maintaining electrical isolation from signal electrodes. This local quality differentiation ensures effective crosstalk prevention without compromising signal integrity or causing short circuits.
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 effectively prevents crosstalk, enabling reliable high-speed signal transmission of 112 Gbps or more over longer distances by reducing Near End Cross Talk (NEXT) and Far End Cross Talk (FEXT) by 5-10 dB across a wide frequency band, ensuring good electrical characteristics.
Implementation Method 1
a first conductive resin cover covering the paddle card substrate, the internal conductors of the cables, and connection portions of the external conductors of the cables. The first conductive resin cover is not electrically connected to the first electrodes for signal, but is electrically connected to the first electrodes for ground.
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
According to an embodiment of the present disclosure, a high-speed transmission device (1) is provided. The device (1) includes a substrate (20): a control device (ASIC10) on the substrate (20); a first connector (30); a second connector (80); and a cable assembly (40) between the first connector (30) and the second connector (80). The first connector (30) is disposed at a position near the control device (ASIC10) on the substrate (20) and electrically connected to the control device (ASIC10) via the substrate (20). The second connector (80) is disposed at a position away from the control device (ASIC10) on the substrate (20) and equipped with an apparatus (90) for transmitting / receiving a signal to and from the control device(ASIC10). The cable assembly (40) includes a cable row (42), a paddle card substrate (41) and a first conductive resin cover (43). Cables (2) each transmitting a differential signal are arranged side by side in the cable row (42). The cables (2) each includes an internal conductor (21) and an external conductor (23). The paddle card substrate (41) is provided with first electrodes for signal (4) and first electrodes for ground (5). Front end portions of the internal conductors (23) of the cables (2) are electrically connected to the first electrodes for signal (4), and front end portions of the external conductors (23) of the cables (2) are electrically connected to the first electrodes for ground (5). The first conductive resin cover (43) covers the paddle card substrate (41), internal conductors (21) of the cables (2), and connection portions of the external conductors (23) of the cables (2). The first conductive resin cover (43) is not electrically connected to the first electrodes for signal (4), but is electrically connected to the first electrodes for ground (5).