EMI Shielding Device for Optical Transceiver with Serrated Contact
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Solution Overview
Problem
Conventional optical modules lack effective EMI shielding, particularly at high-speed interfaces where electromagnetic leakage occurs due to gaps between the upper and lower shells, leading to significant electromagnetic interference.
Innovation Solution
An EMI shielding device with a shell featuring serrated surfaces and a conductive gasket, providing multipoint contact and a shielding cavity to reduce electromagnetic leakage, and utilizing a labyrinth engagement structure for enhanced EMI attenuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional shell structures are used for optical modules, then the device complexity is low and ease of manufacture is high, but electromagnetic leakage occurs at the joint between upper and lower shells leading to poor EMI performance
Solution Approach 1:
The shell is divided into upper and lower covers with intermediate joining structures. The joining structure includes an upper cover lateral plate with serrations and a base side baffle, creating multiple segmented contact points rather than a single continuous joint, thereby reducing electromagnetic leakage through the segmented barrier effect
Solution Approach 2:
The conductive gasket is nested within the joining structure, positioned between the upper cover lateral plate and the base side baffle. This nested arrangement ensures the gasket is securely held in place while maintaining electrical continuity and providing EMI shielding without adding external complexity
2Object-affected harmful factors
If a simple joint structure is used between upper and lower shells, then ease of manufacture is high, but the contact area is insufficient leading to poor electrical continuity and EMI shielding
Solution Approach 1:
The joining structure extends laterally with upper cover lateral plates that protrude outward and downward, creating a three-dimensional joining configuration rather than a simple planar joint. This dimensional extension increases the contact area and provides multiple pathways for electrical continuity while maintaining manufacturability through standard molding processes
3Reliability
If uniform pressure is applied to the conductive gasket, then the contact is reliable, but the gasket may be damaged due to concentrated pressure
Solution Approach 1:
The serrations on the upper cover lateral plate create multiple discrete contact points with the conductive gasket rather than a single continuous contact surface. This segmentation distributes the compressive force across numerous small contact areas, maintaining reliable electrical continuity while preventing localized stress concentration that could damage the gasket
Solution Approach 2:
The serration structure changes the pressure distribution parameter from concentrated to distributed. Each serration tip contacts the gasket at a specific point, creating a pattern of distributed pressure points that achieve reliable electrical contact without exceeding the gasket's stress tolerance
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 reduces electromagnetic leakage and enhances EMI performance by ensuring reliable electrical continuity and distributed pressure on the conductive gasket, preventing damage and circuit shorting while effectively attenuating electromagnetic interference.
Implementation Method 1
A conductive gasket (e.g., a conductive polymer or rubber strip) is under the serrations, and is in contact with the base
Implementation Method 2
each flank having an upper cover lateral plate that extends downward and that includes a lower end or surface. The base comprises a base plate having at least two flanks, each flank having a base side baffle. The upper cover plate or roof is between the base side baffles. The lowermost end or surface of each upper cover lateral plates and/or the lowermost surface of the upper cover plate or roof adjacent to the optical interface have serrations thereon
Data Source
AI summary
An EMI shielding device for an optical transceiver is disclosed. The EMI shielding device includes a shell with an optical and electrical interfaces al opposed ends. The shell includes a base and an upper cover. The upper cover includes a plate having at least two flanks, each having a lateral plate that extends downward. The base includes a base plate having at least two flanks, each having a base side baffle. The upper covet plate is located between the base side baffles. The lower ends or surfaces of the upper cover lateral plates have serrations thereon. A conductive gasket under the serrations contacts the base. The conductive gasket and the serrations result in reliable multipoint contact between the upper cover lateral plates and the base, thereby providing reliable electrical continuity between the upper cover and the base, and reducing electromagnetic leakage.