Conductive Shielding Layer for Keyboard Backlight and EMI
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Solution Overview
Problem
Electronic devices face electromagnetic interference issues due to radio-frequency signals escaping through openings in metal housings, which can cause interference with sensitive receiver circuitry, especially in devices like cellular telephones and computers.
Innovation Solution
A conductive shielding layer made from a polymer coated with reflective metal is applied to the undersides of openings in the housing and connected to the housing using conductive adhesive, serving as a reflector for backlight distribution in keyboards while blocking electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If openings are formed in the conductive housing to accommodate keyboard keys or other components, then the device functionality is improved, but electromagnetic interference is exacerbated due to signal resonance
Solution Approach 1:
The patent applies electromagnetic shielding material specifically at the openings in the conductive housing, rather than covering the entire housing. This localized approach maintains the overall functionality of the device while providing targeted protection against electromagnetic interference at the specific locations where signals can escape and cause resonance.
Solution Approach 2:
The electromagnetic shielding material acts as an intermediary layer between the internal circuitry and the external environment. It blocks and absorbs electromagnetic signals that would otherwise escape through the openings, preventing signal resonance and interference with other components while allowing the openings to remain functional for keyboard keys and other components.
2Object-affected harmful factors
If a conductive shielding layer is added to block electromagnetic interference, then signal interference is reduced, but device complexity increases
Solution Approach 1:
The electromagnetic shielding material is integrated with the keyboard assembly structure, combining the shielding function with the existing support structure. This merging approach reduces the need for separate shielding components and simplifies the overall device architecture while still providing effective electromagnetic interference protection.
Solution Approach 2:
The conductive shielding layer serves multiple functions: it blocks electromagnetic interference, provides structural support for the keyboard assembly, and can be integrated with the housing or support structure. This multi-functionality reduces the need for additional dedicated shielding components, thereby minimizing the increase in device complexity.
3Reliability
If the conductive shielding layer is connected to the conductive housing with conductive adhesive, then electromagnetic shielding effectiveness is improved, but manufacturing complexity increases
Solution Approach 1:
The conductive adhesive serves a dual purpose: it provides mechanical attachment of the shielding layer to the housing while simultaneously creating the electrical connection necessary for electromagnetic shielding effectiveness. This self-service approach eliminates the need for separate electrical connection components, simplifying the manufacturing process while maintaining shielding reliability.
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 interference by blocking radio-frequency signals and maintaining efficient backlight distribution, enhancing the performance of electronic devices by minimizing signal resonance and interference.
Implementation Method 1
a conductive shielding layer may be used to cover the undersides of the openings and the components associated with the openings
Implementation Method 2
The conductive shielding layer may be formed from a polymer layer coated with a layer of reflective metal. The conductive shielding layer may serve as a reflector
Implementation Method 3
The conductive shielding layer may be connected to the conductive housing conductive adhesive around the rectangular periphery
Implementation Method 4
The openings of the support structure may include bridging paths that help to block electromagnetic interference
Data Source
AI summary
An electronic device may have a housing. Components such as keys may be mounted in openings in the housing. The housing may include a display housing portion and a base portion that are coupled using hinge structures. The keys may be used to form a keyboard in the base portion of the housing. Sensitive circuitry such as sensitive wireless circuitry may be shielded from electromagnetic interference by shielding the openings with a layer of conductive material. The layer of conductive material may be a metal layer that forms part of a reflector for a backlight structure. The backlight structure may be used to provide backlight for keys in the keyboard. The keyboard may include a support structure having openings through which the backlight passes to reach the keys. The openings may be bridged using conductive paths so that the support structure serves as a radio-frequency shielding structure.