Plasma Polymerized Conformal Coating for Electrical Assemblies

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Solution Overview

Problem

Conformal coatings like parylene offer excellent chemical, electrical, and physical protection but are costly, energy-intensive, and have low growth rates, necessitating the development of more affordable and efficient alternatives.

Innovation Solution

Plasma polymerization of relatively inexpensive precursor compounds and fluorohydrocarbons to create multilayer conformal coatings, which provide improved protection and are easier to manufacture, with the option to build up multiple discrete layers for enhanced performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If parylene deposition process is used, then chemical, electrical and physical protection is improved, but manufacturing cost and energy consumption increase

Engineering Contradiction:
Improveprotection qualityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The invention changes the chemical parameters of the precursor molecule by introducing fluorine atoms at specific positions (R2-R6) relative to the hydroxyl group. This molecular modification enables the coating to achieve enhanced protection properties while being compatible with lower-cost plasma deposition processes, resolving the contradiction between protection quality and manufacturing cost

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite protective coating system by combining a hydroxyl group with specific fluorinated alkyl or alkenyl groups (C1-C3). This composite molecular structure leverages the benefits of both hydroxyl functionality and fluorinated hydrocarbon chains to achieve superior protection while enabling more economical manufacturing compared to traditional parylene

Inventive Principle:
Principle #40Composite materials

2Reliability

If parylene deposition process is used, then chemical, electrical and physical protection is improved, but energy consumption increases

Engineering Contradiction:
Improveprotection qualityVSAvoidthermal energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The invention modifies the precursor molecule parameters by incorporating fluorinated hydrocarbon groups with specific chain lengths (C1-C3). These parameter changes result in a coating that achieves comparable or superior protection properties while being depositable at lower temperatures through plasma processes, thereby reducing thermal energy consumption

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces the traditional thermal vapor deposition mechanism with a plasma-based deposition mechanism. This substitution allows the coating to be formed at lower temperatures by utilizing plasma activation and reactive species, thereby achieving protection quality improvement without the high thermal energy consumption of conventional parylene processes

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

3Reliability

If parylene deposition process is used, then protection quality is improved, but deposition speed decreases

Engineering Contradiction:
Improveprotection qualityVSAvoiddeposition rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention changes the molecular parameters of the precursor by using fluorinated alkyl or alkenyl groups with 1-3 carbon atoms. These parameter modifications result in a coating material that maintains high protection quality while exhibiting improved deposition kinetics in plasma processes, thereby increasing the deposition rate compared to traditional parylene

Inventive Principle:
Principle #35Parameter changes

4Reliability

If plasma polymerization of fluorohydrocarbon is used, then protection performance is improved, but coating complexity increases

Engineering Contradiction:
Improveprotection performanceVSAvoidcoating structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The invention segments the protective coating into distinct functional components within a single molecular structure: a hydroxyl group providing one function and fluorinated alkyl/alkenyl groups (C1-C3) providing another. This segmentation of functions within a simple molecular framework achieves improved protection performance without increasing overall coating complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The fluorinated hydrocarbon precursor molecule is designed to be multi-functional, with the hydroxyl group contributing to adhesion and protection while the fluorinated hydrocarbon chains provide chemical resistance and durability. This multi-functionality within a single compound simplifies the coating process and structure while enhancing overall protection performance

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

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 resulting coatings offer superior protection to electrical assemblies, are cost-effective, and can be easily identified due to optical interference effects, demonstrating improved performance over single-layer coatings.

Implementation Method 1

plasma polymerization of a compound of formula (I) and deposition of the resulting polymer

Methodology Applied
Scientific EffectPlasma polymerization: Plasma

Implementation Method 2

The chemical vapour is then passed through a high temperature furnace at around 680°C, so that the precursor splits into a reactive monomer. This reactive monomer then feeds into a deposition chamber and polymerizes on the surface of the substrate.

Methodology Applied
Scientific EffectChemical vapour deposition: Chemical Vapour Deposition

Data Source

PatentEP2822705B1Coated electrical assembly
Publication Date: 2016.09.07 SEMBLANT
  • EP2822705B1 patent drawingFigure 1
  • EP2822705B1 patent drawingFigure 2~3
  • EP2822705B1 patent drawingFigure 4~5

AI summary

The present invention relates to an electrical assembly which has a conformal coating, wherein said conformal coating is obtainable by a method which comprises plasma polymerization of a compound of formula (I) and deposition of the resulting polymer and plasma polymerization of a fluorohydrocarbon and deposition of the resulting polymer: (I) wherein: R1 represents C1-C3 alkyl or C2-C3 alkenyl; R2 represents hydrogen, C1-C3 alkyl or C2-C3 alkenyl; R3 represents hydrogen, C1-C3 alkyl or C2-C3 alkenyl; R4 represents hydrogen, C1-C3 alkyl or C2-C3 alkenyl; R5 represents hydrogen, C1-C3 alkyl or C2-C3 alkenyl;; and R6 represents hydrogen, C1-C3 alkyl or C2-C3 alkenyl.