Helical Resistive Structure for High-Voltage Field Uniformity

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Solution Overview

Problem

Existing resistive structures, such as serpentine patterns, fail to provide a uniform electric field distribution at high voltages, leading to high peak electric field intensities, instability, and increased size and cost, making them unsuitable for high-voltage applications.

Innovation Solution

A helical resistive structure is directly printed on a cylindrical insulating substrate using screen printing technology, ensuring a uniform and periodic electric field distribution, eliminating the need for trimming processes and reducing production complexity and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If serpentine resistive structures are used, then the resistive structure can be manufactured using screen printing technology, but the electric field distribution becomes non-uniform with high peak intensities

Engineering Contradiction:
ImprovemanufacturabilityVSAvoidelectric field uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent applies curvature by transitioning from a planar serpentine pattern to a three-dimensional helical winding around a cylindrical substrate. This curvature transformation creates a uniform electric field distribution by distributing the voltage stress evenly along the helical path, eliminating the peak intensities characteristic of flat serpentine designs while maintaining screen-printed manufacturability

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The invention moves the resistive structure from a two-dimensional planar serpentine pattern to a three-dimensional helical configuration wrapped around a cylindrical substrate. This dimensional transition adds the radial dimension to the structure, enabling uniform electric field distribution along the helical path while preserving the ease of manufacture through screen printing technology

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

2Reliability

If high resistance values are used to limit power dissipation at elevated voltages, then the resistor can withstand high voltages, but the device size increases

Engineering Contradiction:
Improvevoltage withstand capabilityVSAvoiddevice size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent embeds the resistive trace within a cylindrical substrate structure, wrapping it helically around the cylinder. This nesting approach allows the resistive element to utilize the three-dimensional space efficiently, achieving high resistance values through multiple windings while maintaining a compact overall device size that would be impossible with planar configurations

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

By transitioning from a two-dimensional planar layout to a three-dimensional helical configuration on a cylindrical substrate, the invention achieves higher resistance values in a more compact volume. The helical path length can be extended through multiple windings around the cylinder without proportionally increasing the device's external dimensions

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

3Manufacturing precision

If trimming operations are performed to achieve desired resistance values, then the resistance accuracy is improved, but production complexity and cost increase

Engineering Contradiction:
Improveresistance accuracyVSAvoidproduction complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent designs the helical resistive structure with parameters (turns, pitch, trace width, substrate dimensions) that are predetermined to achieve the target resistance value directly during the screen printing process. This preliminary design approach eliminates the need for subsequent trimming operations, reducing production complexity while maintaining resistance accuracy through precise control of the printing parameters

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention achieves resistance value control by varying geometric parameters of the helical structure (number of turns, pitch between turns, trace width, trace length) during the screen printing process. These parameter changes allow direct fabrication of resistors with precise resistance values without requiring post-fabrication trimming operations

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

The helical structure achieves up to 50% reduction in voltage stress compared to serpentine designs, enabling high-voltage withstand with smaller size, improved accuracy, and lower production effort, while maintaining stability and accuracy.

Implementation Method 1

Resistors to be employed at elevated or high voltages typically feature high resistance value in order to limit the power dissipation

Methodology Applied
Scientific EffectElectrical resistance: Electrical Resistance

Implementation Method 2

The conductive and resistive material layers are sequentially deposited on an electrically insulating substrate of planar or cylindrical shape

Methodology Applied
Scientific EffectScreen printing deposition: Deposition (physical)

Data Source

PatentEP2678869B1Resistive structure and resistive voltage divider arrangement
Publication Date: 2018.10.17 ABB AG(DE)
  • EP2678869B1 patent drawingFigure 1~2
  • EP2678869B1 patent drawingFigure 3~4
  • EP2678869B1 patent drawingFigure 5~6

AI summary

The invention relates to a resistive structure with an improved electric field profile deposited on the surface of a cylindrical insulating substrate (20), whereas at least one resistive path or trace (23,33,43,54,64) is provided with a shape looking like a helix and is directly printed on the surface of the insulating substrate (20,30,40,50,60). Furthermore, a resistive voltage divider is claimed comprising at least a first and a second resistor electrically connected in series, where each resistor is made of one or more traces (23,33,43,54,55,64,65) of electrically resistive film material applied onto a cylindrical insulating substrate (20,30,40,50,60) and wherein at least one of the traces is shaped like a helix and is applied onto the substrate (20,30,40,50,60) by direct printing.