Wireless Power Coil Shielding for Thin Low-Leakage Modules
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless power transmitting modules face a challenge in minimizing magnetic field leakage while maintaining a required thickness, which reduces charging efficiency when embedded in devices like notebook trackpads or portable batteries due to eddy currents generated by metallic components.
Innovation Solution
A wireless power transmitting module design featuring a flat coil with a main shielding sheet and an auxiliary shielding sheet, where the auxiliary sheet is thinner and covers the accommodating portion for terminal wires, preventing magnetic field leakage and eddy currents, and includes a coil unit with multiple wires for reduced resistance and thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If an accommodating portion is formed in the shielding sheet to reduce thickness, then the overall thickness of the wireless power transmitting module is reduced, but magnetic field leakage occurs through the accommodating portion
Solution Approach 1:
The shielding sheet is segmented into a main shielding sheet and an auxiliary shielding sheet. The main shielding sheet has an accommodating portion for the leading wire, while the auxiliary shielding sheet is attached to cover the accommodating portion. This segmentation allows the module to maintain thin overall thickness while preventing magnetic field leakage through the accommodating portion.
Solution Approach 2:
The auxiliary shielding sheet is nested on the main shielding sheet, specifically covering the accommodating portion. This nested structure allows the thinner auxiliary sheet to supplement the shielding function at the critical accommodating portion without significantly increasing the overall thickness of the module.
2Length of stationary object
If the auxiliary shielding sheet is made thinner to minimize thickness increase, then the overall thickness is minimized, but shielding effectiveness may be reduced
Solution Approach 1:
The auxiliary shielding sheet is designed with local quality - it is thinner than the main shielding sheet but is strategically positioned to cover the accommodating portion where magnetic field leakage occurs. This local shielding approach provides sufficient shielding effectiveness at the critical area while maintaining thin overall thickness.
Solution Approach 2:
The shielding system uses a composite structure combining the main shielding sheet and auxiliary shielding sheet. The main sheet provides bulk shielding, while the auxiliary sheet provides targeted shielding at the accommodating portion. This composite approach achieves effective shielding with minimized thickness.
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 design enhances charging efficiency by minimizing magnetic field leakage and maintaining a thin profile, effectively preventing eddy currents and ensuring efficient wireless charging even with metallic components nearby.
Implementation Method 1
a main shielding sheet disposed on one surface of the coil unit to shield a magnetic field generated from the coil unit
Implementation Method 2
an auxiliary shielding sheet attached to one surface of the main shielding sheet so as to cover the accommodating portion in order to shield a magnetic field leaking through the accommodating portion
Implementation Method 3
when a metallic component such as a battery or a metallic housing is disposed below the wireless power transmitting module, the magnetic field leaked through the accommodating portion generates an eddy current due to the metallic material
Data Source
AI summary
Disclosed is a wireless power transmitting module comprising: a coil unit provided with a coil body in which a conductive member having a predetermined length is wound in one direction, and with a planar coil including a pair of terminal portions extending from the coil body by a predetermined length for electrical connection; a main shielding sheet arranged on one surface of the coil unit to shield a magnetic field generated from the coil unit; an accommodating portion formed through the main shielding sheet so as to accommodate the thickness of at least one of the pair of terminal portions; and an auxiliary shielding sheet attached to one surface of the main shielding sheet so as to cover the accommodating portion in order to shield a magnetic field leaking through the accommodating portion, wherein the auxiliary shielding sheet has a relatively thinner thickness than the main shielding sheet.