Shielded Microphone Assembly for Mobile Device EMI Isolation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing mobile communications devices face challenges in shielding microphones from electromagnetic noise emitted by nearby antennas while maintaining cost-effective electrical connections that accommodate manufacturing tolerances during assembly.
Innovation Solution
A shielded microphone assembly is designed with a conductive electromagnetic shield and a resilient separator, such as an o-ring or disk, which is sandwiched between the device housing and circuit board to absorb pressure and ensure electrical grounding, thereby isolating the microphone from electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conductive gasket is used to connect the electromagnetic shield to the circuit board, then electrical connection and tolerance accommodation are achieved, but manufacturing cost increases and assembly complexity increases
Solution Approach 1:
The patent combines the electromagnetic shield and separator into a single integrated component. The shield body directly contacts the circuit board to establish electrical connection, while the integrated separator absorbs assembly tolerances and stack pressure, eliminating the need for a separate conductive gasket and reducing assembly complexity
Solution Approach 2:
The electromagnetic shield serves multiple functions simultaneously: it provides electromagnetic shielding, establishes electrical connection to ground through direct contact with the circuit board, and the integrated separator accommodates assembly tolerances and absorbs stack pressure, replacing what were previously separate components
2Reliability
If a conductive gasket is used to connect the electromagnetic shield to the circuit board, then electrical connection and tolerance accommodation are achieved, but manufacturing cost increases
Solution Approach 1:
The patent combines the electromagnetic shield and separator into a single integrated component, reducing the total part count and eliminating the need for separate conductive gaskets, thereby lowering manufacturing costs while maintaining reliable electrical connection through direct shield-to-board contact
Solution Approach 2:
The integrated shield performs multiple functions including electromagnetic shielding, electrical grounding, and tolerance accommodation through its integrated separator, replacing what were previously multiple separate components and reducing overall manufacturing complexity and cost
3Reliability
If the housing is stacked over the assembly to load the separator, then electrical connection and tolerance accommodation are achieved, but assembly pressure may cause strain and damage to parts
Solution Approach 1:
The separator is positioned between the housing and the electromagnetic shield assembly before final stacking. This resilient component acts as a cushion that absorbs and distributes the stack pressure, preventing excessive force from being transmitted to the microphone, circuit board, or other sensitive components while still ensuring reliable electrical connection
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 solution effectively shields the microphone from electromagnetic noise, reduces manufacturing costs by eliminating the need for expensive conductive gaskets, and ensures reliable electrical connections despite assembly tolerances.
Implementation Method 1
a resilient separator, preferably an electrical insulator, is positioned between the housing and the electromagnetic shield and the shielded microphone assembly is configured to cooperate with the housing and the circuit board to electrically connect each of the microphone and the electromagnetic shield to the circuit board when the housing is stacked over the shield to load the separator
Implementation Method 2
a conductive, electromagnetic shield (e.g. a shielding can) is provided over the microphone and a separator (e.g. an o-ring-type) is placed over the shield, forming an assembly configured to co-operate with the housing and the circuit board to electrically connect each of the microphone and the electromagnetic shield to the circuit board
Data Source
AI summary
A shielded microphone, and method for shielding a microphone, are provided for use in a communications device having a circuit board and a microphone. The microphone is provided in an electromagnetic shield and a resilient separator is provided over the shield. The device housing is stacked over the separator and shield, while the latter are stacked over the circuit board so that the separator and shield, with microphone there under, are sandwiched between the housing and the circuit board. By this sandwiching the separator is loaded onto the shield to drive the shield directly against the circuit board to make an electrical ground connection therewith, the microphone also being electrically connected to the printed circuit board. The resilience of the separator accommodates the variation in the stacking of the components.