Variable-Width Inductor Windings for Higher Saturation Current

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Solution Overview

Problem

Inductors with soft magnetic materials face limitations in maximum current due to magnetic flux saturation, and hybrid structures with air gaps or open spaces compromise magnetic flux density.

Innovation Solution

The design includes an inductor with windings of different widths around a magnetic core, where each winding has segments in different wiring layers, allowing for varying flux densities across the core.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If soft magnetic materials are used in inductors, then magnetic flux density is improved, but maximum current is limited due to magnetic flux saturation

Engineering Contradiction:
Improvemagnetic flux densityVSAvoidmaximum current capability
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent applies local quality by creating different winding widths at different locations along the magnetic core. The first portion of the magnetic core has windings with a first width, while the second portion has windings with a second width that is different from the first width. This allows different regions to have different flux densities, enabling the inductor to handle higher currents without saturating the entire core uniformly.

Inventive Principle:
Principle #3Local quality

2Reliability

If hybrid device structures combining soft magnetic materials with empty space are used, then saturation current is improved, but magnetic flux density is limited

Engineering Contradiction:
Improvesaturation currentVSAvoidmagnetic flux density
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent changes the geometric parameter of the windings by varying the width along the length of the magnetic core. By transitioning from a uniform width to a non-uniform width profile, the flux density distribution is modified. This parameter change allows the inductor to achieve higher saturation currents while maintaining adequate magnetic flux density through the strategic variation of winding dimensions.

Inventive Principle:
Principle #35Parameter changes

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 configuration distributes flux density more uniformly across the magnetic core, enabling higher saturation currents without exceeding undesirable magnetic field strengths.

Implementation Method 1

transmitting a current through the inductor to induce a magnetic flux within the magnetic core

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4560655A1Structure and method for inductor with windings having different widths
Publication Date: 2025.05.28 GLOBALFOUNDRIES US INC
  • EP4560655A1 patent drawingFigure 1
  • EP4560655A1 patent drawingFigure 2
  • EP4560655A1 patent drawingFigure 3

AI summary

The disclosure provides a structure and method for an inductor with windings having different widths. A structure may include an inductor including a plurality of windings about a magnetic core. Each winding has a first segment within a first wiring layer coupled to a second segment within a second wiring layer. The plurality of windings includes a first winding having a first width along a same direction as a length of the magnetic core and a second winding having a second width along the same direction as the length of the magnetic core. The second width is larger than the first width.