Magnetic Shielding Film with Aligned Fillers and Rapid Phase Locking

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing methods for forming magnetic shielding films face challenges in achieving high magnetic saturation and permeability while maintaining mechanical integrity, due to difficulties in processing high-solid mixtures and orienting flake particulates, and the slow locking of ordered structures during film formation.

Innovation Solution

A novel method involving a thermally-induced phase separation process with a short magnetic field application to orient anisotropically-shaped particles, followed by rapid locking using a first-order phase transition, and subsequent densification to create a magnetic shielding film with high particle alignment and minimal voids.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If high-solid mixtures are used to achieve high particle concentration, then magnetic saturation and permeability are improved, but processing difficulty and mechanical integrity deteriorate

Engineering Contradiction:

Improveparticle concentrationVSAvoidprocessing difficulty

Core Design Contradiction:

Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent changes the physical state of the mixture from solid to liquid by adding a binder, enabling high particle concentration (greater than 50 vol%) to be processed in a liquid slurry form. This allows conventional casting and forming techniques to be used while maintaining high magnetic filler content, thereby improving magnetic saturation and permeability without sacrificing processability

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system consisting of magnetic particles dispersed in a binder matrix. This composite structure allows the magnetic particles to be distributed uniformly at high concentrations while the binder provides mechanical integrity and processability, resolving the contradiction between high particle content and ease of manufacture

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If flake particulates are used to achieve high magnetic saturation, then magnetic properties are improved, but particle orientation control deteriorates

Engineering Contradiction:

Improvemagnetic saturationVSAvoidparticle orientation

Core Design Contradiction:

Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent applies a magnetic field during the slurry casting process to preliminarily orient the flake particulates in the desired direction before the binder sets. This preliminary orientation action ensures that the particles are aligned correctly while the mixture is still in a mobile state, allowing precise control of particle orientation while maintaining high magnetic saturation

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses the liquid binder as an intermediary medium that allows flake particulates to be suspended and oriented by magnetic fields. The binder provides a fluid matrix that enables particle movement and alignment, which would not be possible in a dry or solid state, thereby achieving both high magnetic saturation and precise orientation control

Inventive Principle:

Principle #24Intermediary (Mediator)

3Stability of the object's composition

If conventional film formation is used to maintain mechanical integrity, then structural stability is improved, but particle alignment speed deteriorates

Engineering Contradiction:

Improvemechanical integrityVSAvoidalignment speed

Core Design Contradiction:

Stability of the object's compositionVSSpeed

Solution Approach 1:

The patent utilizes a rapid phase transition from liquid slurry to solid film through quick binder setting or solvent evaporation. This rapid phase change locks in the particle alignment quickly, achieving both fast alignment speed and mechanical integrity in a single step, eliminating the need for slow conventional drying or curing processes

Inventive Principle:

Principle #36Phase transitions

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 method achieves a magnetic shielding film with enhanced magnetic saturation and permeability, improving wireless charging efficiency by maintaining high power transfer rates with reduced attenuation, and providing superior mechanical integrity.

Implementation Method 1

applying a magnetic field to the layer to orient the particles along substantially a same orientation direction

Methodology Applied

Scientific EffectMagnetic field orientation: Magnetic Field

Implementation Method 2

inducing a phase separation of the polymer from the diluent while the magnetic field is applied to the layer

Methodology Applied

Scientific EffectPhase separation: Phase Change

Data Source

PatentUS20240373606A1Orientation of magnetic fillers to optimize film properties

Publication Date: 2024.11.07 3M INNOVATIVE PROPERTIES CO

AI summary

A magnetic shielding film includes opposing first and second major surfaces and a plurality of particles dispersed therebetween, each particle having a magnetic permeability, a thickness H along a thickness direction of the particle, and a longest dimension L along a length direction of the particle orthogonal to the thickness direction, L/H greater than or equal to 2, the particles defining a plurality of voids therebetween, the length directions of at least 60% of the particles oriented within 5.5 degrees of a same orientation direction.