Shield Cover Contact Piece for Stable PCB Grounding
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Solution Overview
Problem
Existing display devices face variability in contact resistance between metallic shield covers and ground patterns on printed circuit boards due to machining inaccuracies, leading to unstable electrical conduction and potential malfunctions.
Innovation Solution
A display device design featuring a metallic shield cover with integral side plates and contact pieces that include protrusions and claws, securely fastened via male screws through bosses, ensuring consistent contact with ground patterns on the printed circuit board, thereby stabilizing contact resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a metallic shield cover is fixed to a printed circuit board through a rear frame, then the shield cover provides electromagnetic shielding, but contact resistance between the shield cover and ground pattern varies due to machining inaccuracies
Solution Approach 1:
The contact piece is designed with elastic deformation capability, allowing it to dynamically adapt to machining variations. The elastic material enables the contact piece to deform and maintain stable contact with the ground pattern despite variations in rear frame dimensions, resolving the contradiction between reliability and manufacturing precision.
Solution Approach 2:
The invention changes the physical state of the contact piece from rigid to elastic, utilizing the elastic properties to compensate for machining inaccuracies. This parameter change allows the system to maintain stable contact resistance even when the rear frame dimensions vary within tolerances.
2Reliability
If the shield cover is rigidly fixed to ensure stable contact, then contact resistance is stable, but frictional noise increases in vibrating environments
Solution Approach 1:
The elastic contact piece provides dynamic contact that can accommodate vibrations without generating excessive frictional noise. The elasticity allows the contact to remain stable electrically while reducing mechanical friction during vibration, resolving the contradiction between conduction stability and noise generation.
Solution Approach 2:
The contact piece is made of elastic material that acts as a flexible element between the rigid shield cover and the ground pattern. This flexibility maintains electrical contact stability while reducing frictional noise during vibrations, addressing the contradiction between reliable conduction and noise reduction.
3Object-generated harmful factors
If the contact piece is made elastic to reduce frictional noise, then frictional noise decreases, but contact stability may be compromised
Solution Approach 1:
The elastic contact piece serves as a flexible intermediary that maintains stable electrical contact while reducing frictional noise. The elastic properties ensure continuous contact despite vibrations, simultaneously achieving noise reduction and contact stability.
Solution Approach 2:
By changing the material property from rigid to elastic, the system achieves both reduced frictional noise and maintained contact stability. The elastic deformation capability allows the contact piece to adapt to vibrations without losing electrical contact, resolving the apparent contradiction between noise reduction and stability.
Data Source
AI summary
According to an aspect, a display device includes: a display panel; a housing; a printed circuit board; a boss that penetrates a first through hole in the printed circuit board and protrudes from a surface of the housing, the surface being attached to the printed circuit board; a shield cover; and a male screw. The shield cover includes: a top plate; side plates; and a contact piece formed by folding a part of one of the side plates inward and including a protrusion in contact with a ground pattern of the printed circuit board and a claw facing the top plate. The protrusion causes the claw to protrude toward the printed circuit board. The male screw is fastened to the boss from the outside of the top plate.