Conductive Elastomer Grounding for Portable Device EMI
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Solution Overview
Problem
Portable computing devices face challenges in reducing unwanted electrical noise (EMI) due to poor electrical couplings between enclosure components, allowing EMI to escape, especially in targeted regions.
Innovation Solution
Enhancing electrical coupling between the base and display portions of a portable computing device using conductive elastomers and USB ground plates to create improved electrical pathways, particularly in regions like the clutch assembly and vent areas, to minimize EMI interference and emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional enclosure components are used without enhanced electrical coupling, then device complexity is reduced, but EMI emissions increase due to poor electrical pathways
Solution Approach 1:
A conductive elastomer is introduced as an intermediary component between the clutch assembly and the enclosure to establish improved electrical coupling. The elastomer includes conductive pathways that bridge the electrical gap, allowing EMI suppression without requiring direct metal-to-metal contact or complex grounding structures.
Solution Approach 2:
The conductive elastomer is selectively positioned at specific locations where electrical coupling is needed, such as near the clutch assembly and USB connector regions. This localized approach enhances EMI shielding only where necessary, rather than requiring comprehensive grounding throughout the entire enclosure.
2Object-affected harmful factors
If conductive elastomers and USB ground plates are added to enhance electrical coupling, then EMI shielding performance improves, but device complexity increases
Solution Approach 1:
The conductive elastomer serves multiple functions simultaneously: it provides electrical coupling for EMI shielding, maintains mechanical flexibility for assembly, and creates reliable electrical pathways without requiring additional separate components. The USB ground plate similarly integrates grounding functionality into an existing structural element.
Solution Approach 2:
The elastomer combines conductive materials with flexible polymer matrices to create a composite material that exhibits both electrical conductivity and mechanical compliance. This allows the component to function as both an electrical pathway and a flexible mounting element, reducing the need for separate rigid grounding components.
3Object-affected harmful factors
If poor electrical couplings exist between enclosure parts, then manufacturing is simpler, but EMI noise escapes more readily
Solution Approach 1:
The conductive elastomer is implemented as a flexible component that can be easily conformed to various enclosure geometries and installed in tight spaces. Its flexibility allows for simple assembly processes where the elastomer can be compressed or molded into place without requiring precision alignment or complex fastening procedures.
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 enhanced electrical coupling effectively reduces EMI interference and emissions, improving the overall shielding performance of portable computing devices by ensuring better conductivity and grounding within the device's enclosure.
Implementation Method 1
a conductive elastomer configured to enhance an electrical contact between the clutch assembly and at least one portion of the base portion
Implementation Method 2
a USB ground plate mechanically and electrically attached to the base portion configured to contact an electrical sheath of the USB connector
Implementation Method 3
the boss including a conductive elastomer configured to form an electrical pathway between the top case and the bottom case
Data Source
AI summary
A portable computing device can include one or more clutch assemblies that can include a conductive elastomer configured to contact at least a portion of the clutch assembly of the portable computing device. The conductive elastomer can be configured to also contact at least one region of the base portion of the portable computing device and can include highly conductive regions. A USB grounding plate can be attached to a portion of a case for the portable computing device and can be configured to provide a ground pathway between the case and a ground sheath of a USB connector inserted into an opening in a side wall of the case.