Laser Textured Anti-Multipactor Coating for RF Components

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Solution Overview

Problem

Existing anti-multipactor coatings for RF and MW components are inadequate in reducing secondary electron yield (SEY) and cannot effectively utilize gold due to chemical inertness, and existing production methods are inefficient and unsuitable for complex surfaces, leading to non-uniform textures and increased RF losses.

Innovation Solution

A method involving the deposition of gold, silver, or their alloys on metal substrates followed by femtosecond laser texturing to create regular patterns of cavities, which act as electron traps, reducing SEY and enhancing surface conductivity while allowing precise control over texture and localized application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If chemical etching is used to create anti-multipactor coating, then secondary electron yield is reduced, but the process cannot achieve uniform texture and requires immersion in chemical baths which limits localized application

Engineering Contradiction:
Improvesecondary electron yieldVSAvoidtexture uniformity
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The patent replaces chemical etching processes with laser-based texturing to create anti-multipactor surfaces. The laser method uses optical energy instead of chemical reactions, allowing precise control over surface texture without immersion in chemical baths, thereby achieving uniform texture while enabling localized application.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent modifies the surface texture parameters by controlling laser processing conditions (power, speed, pulse duration) to create optimal cavity structures that reduce secondary electron yield. By adjusting these parameters, uniform texture is achieved across the surface while maintaining the ability to apply treatment locally.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If photolithography is used to create micro-pores, then simple hole shapes are produced, but the process cannot handle three-dimensional surfaces or surfaces with large radius of curvature

Engineering Contradiction:
Improvehole shape simplicityVSAvoidsurface geometry compatibility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent replaces photolithography with laser texturing technology. The laser method uses optical focusing to create micro-cavities directly on the surface without requiring photoresist layers or development processes, enabling treatment of complex three-dimensional surfaces, curved surfaces, and surfaces with varying geometries.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extends the surface treatment capability from two-dimensional flat surfaces to three-dimensional complex surfaces by using laser focusing in the third dimension. The laser can be positioned and focused on surfaces with varying curvature and geometry, creating uniform micro-cavity patterns regardless of surface complexity.

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

3Productivity

If conventional laser texturing is used, then surface treatment is achieved, but the cavity interval pitch is too large to optimally reduce secondary electron yield

Engineering Contradiction:
Improvesurface treatment efficiencyVSAvoidsecondary electron yield
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent optimizes the laser processing parameters including pulse duration, power density, and scanning speed to create micro-cavities with interval pitch between 0-100 μm. This parameter optimization ensures the cavities are closely spaced to effectively trap secondary electrons and reduce yield, while maintaining efficient processing speed.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses periodic laser pulsing to create regularly spaced micro-cavities on the surface. The periodic action of the laser ensures uniform cavity distribution with optimal spacing, creating a consistent texture pattern that maximizes electron trapping efficiency while maintaining processing productivity.

Inventive Principle:
Principle #19Periodic action

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 solution significantly reduces SEY and enhances transmission power by creating uniform, efficient electron traps on complex surfaces, improving RF signal transmission without increasing RF losses and allowing the use of gold, a previously challenging material.

Implementation Method 1

laser treatment of the coating deposited according to step (a), so as to obtain a texturing of the coating deposited, with one or more patterns repeated at regular intervals of cavities

Methodology Applied
Scientific EffectLaser ablation: Laser Ablation

Implementation Method 2

deposition of a coating of a constituent material chosen from the metals of column 10 or column 11 of the Mendeleev table or an alloy of these metals, on at least a surface portion of the metal substrate

Methodology Applied
Scientific EffectDeposition: Deposition (physical)

Data Source

PatentEP3693497B1Anti-multipactor coating deposited on RF or mw metal component, method for producing such a coating by laser texturing
Publication Date: 2022.03.30 RADIALL SA
  • EP3693497B1 patent drawingFigure 1~2B
  • EP3693497B1 patent drawingFigure 3~5
  • EP3693497B1 patent drawingFigure 6~8

AI summary

The invention relates to a method of producing by laser ablation on a metallic substrate an anti-multipactor coating whose constituent material is chosen from the metals of column 10 or column 11 of the Mendeleev table or an alloy of these metals and whose texture comprises one or more repeated patterns, at regular intervals of cavities, the pitch of the interval between two adjacent cavities being between 0 and 100 µm.