Multi-Compartment Shielding Container for EMI and Stiffness
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Solution Overview
Problem
Handheld electronic devices face interference issues due to the close proximity of electronic components on printed circuit boards, leading to electromagnetic interference (EMI) that degrades receiver sensitivity and causes audio breakthroughs, and existing shielding solutions either hinder repairability or fail to provide sufficient stiffness and inter-compartment shielding.
Innovation Solution
A multi-compartment shielding container with a shielding frame and lid, featuring a planar base with openings, opposing side and end walls, and intermediate partition walls that create compartments with radiused corners for stiffness and adequate shielding, eliminating the need for soldered joints and allowing for easy assembly and inspection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a first type of shielding container (one entire box shaped piece soldered onto the printed circuit board) is used, then EMI shielding is provided, but access to components covered by the shielding container is not permitted, making repair or inspection very difficult
Solution Approach 1:
The shielding container is divided into two separate pieces: a frame that is soldered to the printed circuit board and a lid that snaps onto the frame. This segmentation allows the lid to be removed for component access while the frame remains permanently attached for EMI shielding, resolving the contradiction between shielding effectiveness and repairability.
2Ease of repair
If a second type of shielding container (two pieces with lid snapped onto frame) is used, then component access is enabled, but there is a need for holes or apertures in the lid to let in heat during soldering, otherwise components will not be properly soldered
Solution Approach 1:
The lid is designed with built-in heat conduction features that transfer heat from the soldering area through the lid to the components during the soldering process. This preliminary heat distribution ensures proper soldering occurs even with the lid in place, eliminating the need for apertures and maintaining manufacturing precision while preserving component access.
3Productivity
If the lid is snapped onto the frame and then soldered assembly is attempted, then work operations are saved, but there are problems getting a good solder joint when using a pre-joined shielding container
Solution Approach 1:
The shielding container is segmented into a frame and lid that are assembled separately before final attachment. The frame is soldered to the board first, then the lid is snapped onto the frame. This segmentation allows each component to be properly soldered independently without the constraints of a pre-assembled unit, ensuring good solder joints while maintaining manufacturing efficiency.
4Object-affected harmful factors
If partition walls extend fully between opposing side walls, then complete compartmentalization is achieved, but stiffness of the shielding frame is reduced
Solution Approach 1:
The partition walls are designed to extend only partway between the opposing side walls rather than fully connecting them. This local modification maintains adequate EMI shielding between compartments while preserving the structural stiffness of the frame by leaving gaps that prevent stress concentration and maintain overall frame rigidity.
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 shields electronic components from EMI, maintains device stiffness, and facilitates easy assembly and repair by eliminating the need for soldered joints, while providing adequate compartmentalization for printed circuit boards within handheld electronic devices.
Implementation Method 1
A shielding container can protect components on a printed circuit board (PCB), preferably for a cellular phone, against interference from other components due to EMI
Implementation Method 2
featuring a planar base with openings, opposing side and end walls, and intermediate partition walls that create compartments with radiused corners for stiffness
Data Source
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AI summary
A handheld electronic device may include a portable housing and a shielding container within the portable housing. The shielding container may include a shielding frame and a shielding lid carried thereby. A printed circuit board may be within the shielding container. The shielding frame may include a planar base with at least one opening therein, a pair of opposing side walls integrally formed with the base and extending upwardly therefrom, and a pair of opposing end walls integrally formed with the base and extending upwardly therefrom. Also, the shielding frame may include at least one intermediate partition wall integrally formed with the base and extending upwardly therefrom to define a plurality of container compartments. The partition wall may also extend only partway between the opposing side walls to define at least one partition end gap therewith.