Embedded PCB Winding Assembly for Lower Transformer Parasitic Capacitance

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Solution Overview

Problem

Traditional planar transformers suffer from large parasitic capacitors between the primary and secondary coils, which significantly impact the efficiency of power converters.

Innovation Solution

A winding assembly is designed with a first coil embedded inside a circuit board, where the conductive wire's height is greater than its width, and additional flat copper coils are either on or embedded within the circuit board, reducing parasitic capacitance by minimizing the facing area between coils.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional planar transformer coils are used with conventional geometry, then the structure is simple and easy to manufacture, but the parasitic capacitance between primary and secondary coils is large

Engineering Contradiction:
Improvecoil structure simplicityVSAvoidparasitic capacitance
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent applies asymmetry by changing the conventional coil geometry where height equals width, to a configuration where the height of the conductive wire is greater than its width. This asymmetric geometry reduces the facing area between primary and secondary coils, thereby decreasing parasitic capacitance while maintaining manufacturability through standard embedding processes

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent utilizes the vertical dimension by increasing the height of the conductive wire perpendicular to the circuit board. This dimensional change allows the coils to be stacked more efficiently with reduced facing area between layers, reducing parasitic capacitance without complicating the manufacturing process

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

2Object-generated harmful factors

If the height of conductive wire is increased to be greater than its width, then parasitic capacitance is reduced, but the manufacturing precision requirements increase

Engineering Contradiction:
Improveparasitic capacitanceVSAvoidconductive wire geometry precision
Core Design Contradiction:
Object-generated harmful factorsVSManufacturing precision

Solution Approach 1:

The patent merges the conductive wire formation with the existing circuit board manufacturing process. The conductive wire is embedded during the standard PCB lamination process, combining the coil formation with the circuit board fabrication. This integration maintains manufacturing simplicity while achieving the required height greater than width geometry

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3907750B1Winding assembly and magnetic assembly
Publication Date: 2023.10.04 DELTA ELECTRONICS (SHANGHAI) CO LTD
  • EP3907750B1 patent drawingFigure 1~4
  • EP3907750B1 patent drawingFigure 5~6
  • EP3907750B1 patent drawingFigure 7~8

AI summary

The present invention provides a winding assembly (10) and a magnetic assembly. The winding assembly (10) comprises a first coil (101) and a circuit board (102), and the first coil (101) is embedded inside the circuit board (102); wherein the first coil (101) comprises a conductive wire with at least one turn, and the height of the conductive wire in a direction perpendicular to the circuit board (102) is not less than the width of the conductive wire in a direction parallel to the circuit board. The magnetic assembly comprises a first winding assembly and a magnetic core; wherein the first winding assembly comprises a first coil and a first circuit board, and the first coil comprises a conductive wire with at least one turn, the first coil being embedded inside the first circuit board, the first winding assembly (801) being assembled with the magnetic core.