PCB Planar Magnetic Component for Compact Resonant Converters

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Solution Overview

Problem

Resonant converters are bulky due to traditional magnetic components, limiting their size reduction and power density, and thus efficiency.

Innovation Solution

A planar magnetic component is integrated into a resonant converter, featuring inductor and primary/secondary-side traces on a circuit board with an iron core assembly, allowing for a compact design that increases space utilization and operating frequency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If traditional magnetic components (coils, bobbins, iron cores) are used in resonant converters, then the magnetic circuit is closed and inductance is achieved, but the size becomes bulky and power density is poor

Engineering Contradiction:
Improvesize of resonant converterVSAvoidpower density
Core Design Contradiction:
Volume of moving objectVSProductivity

Solution Approach 1:

The patent transitions from traditional three-dimensional wound coils to planar traces formed on circuit board layers. The inductor and transformer windings are created using PCB fabrication techniques, where copper traces are deposited on and between board layers, fundamentally changing the geometric dimensionality from volumetric winding to planar routing.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent changes the physical parameters of the magnetic component by using planar traces with specific width, length, and layer configuration to achieve the required inductance values. The trace dimensions, number of layers, and spacing are optimized to provide the necessary magnetic properties while maintaining a compact footprint.

Inventive Principle:
Principle #35Parameter changes

2Power

If traditional wound coils are used, then proper inductance can be achieved, but the converter size cannot be effectively reduced

Engineering Contradiction:
Improvepower conversion capabilityVSAvoidconverter size
Core Design Contradiction:
PowerVSVolume of moving object

Solution Approach 1:

The patent merges the inductor and transformer into a single planar magnetic component structure. Both functions are implemented using traces on the same circuit board, sharing common magnetic path through the iron core assembly, thereby reducing overall component count and volume while maintaining power conversion capability.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The planar magnetic component structure serves multiple functions simultaneously - the same iron core assembly provides magnetic path for both the inductor and transformer, and the circuit board structure supports both energy storage and energy transfer functions within a unified design.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Productivity

If resonant converter size is reduced using planar design, then power density increases, but operating frequency must be increased to maintain performance

Engineering Contradiction:
Improvepower densityVSAvoidoperating frequency
Core Design Contradiction:
ProductivityVSSpeed

Solution Approach 1:

The patent optimizes the trace dimensions, iron core material properties, and magnetic path length to achieve the required inductance at higher operating frequencies. By adjusting these parameters, the planar component maintains adequate magnetic coupling and energy storage capability despite the reduced physical size and higher frequency operation.

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 design significantly reduces the size of resonant converters, enhances power density, efficiency, and heat dissipation, while minimizing power switch size and weight.

Implementation Method 1

The inductor trace is arranged on the circuit board to serve as an inductor coil coupled to the primary-side circuit. The primary-side trace is formed on one primary-side layer board of the circuit board to serve as a primary-side coil coupled to the primary-side circuit. The secondary-side trace is formed on one secondary-side layer board of the circuit board to serve as a secondary-side coil coupled to the secondary-side circuit.

Methodology Applied
Scientific EffectMagnetic flux: Magnetic Field

Implementation Method 2

the iron core is used to set the winding to form a closed magnetic circuit

Methodology Applied
Scientific EffectClosed magnetic circuit: Magnetic Field

Data Source

PatentEP4369364A1Planar magnetic component
Publication Date: 2024.05.15 DELTA ELECTRONICS INC(CN)
  • EP4369364A1 patent drawingFigure 1
  • EP4369364A1 patent drawingFigure 2A
  • EP4369364A1 patent drawingFigure 2B

AI summary

A planar magnetic component (PE) is arranged on a circuit board (CB1) of a resonant converter (100), and the resonant converter (100) includes a primary-side circuit (1A) and a secondary-side circuit (3A). The planar magnetic component (PE) includes an inductor trace (Tl), a primary-side trace (Tp1), a secondary-side trace (Ts1), and an iron core assembly. The iron core assembly includes an inductor iron core (C_L) and an iron core (C1). The primary-side trace (Tp1) surrounds the first through hole (H1) in a first direction (D1) and surrounds the second through hole (H2) in a second direction (D2) to form an oo-shaped trace. The inductor trace (TI) is formed on the primary-side layer board and coupled to the primary-side trace (Tp1), and two ends of the inductor trace (TI) form an input terminal and an output terminal of the planar magnetic component (PE).