Azeotrope-like Mixtures for Semiconductor Cleaning

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Solution Overview

Problem

The semiconductor industry faces challenges in finding environmentally safe solvents for cleaning applications, as chlorofluorocarbons harm the ozone layer, and hydrofluorocarbons contribute to global warming, necessitating the development of new solvents for removing residual flux, lubricants, and contaminants without environmental impact.

Innovation Solution

Azeotropic and azeotrope-like compositions comprising 1,1,1,2,2,3,4,5,5-decafluoropentane, 1,1,2,2,3,3,4-heptafluorocyclopentane, and trans-1,2-dichloroethylene, with optional alcohol additives, which form constant boiling mixtures effective in dissolving oils and contaminants, replacing traditional CFC compounds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If chlorofluorocarbon (CFC) compounds are used for cleaning semiconductor surfaces, then cleaning effectiveness is improved, but environmental harm to the ozone layer increases

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidozone layer harm
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by replacing CFC compounds with HFC compounds and trans-1,2-dichloroethylene in specific proportions (5-50% HFC-43-10mee, 50-95% trans-1,2-dichloroethylene). This parameter change maintains cleaning effectiveness while eliminating ozone-depleting chlorine-containing compounds, thus resolving the contradiction between cleaning effectiveness and environmental harm.

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If hydrofluorocarbon (HFC) compounds are used to replace CFC compounds, then environmental safety regarding ozone layer is improved, but contribution to global warming increases

Engineering Contradiction:
Improveozone layer safetyVSAvoidglobal warming contribution
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent creates a composite solvent system combining HFC-43-10mee and trans-1,2-dichloroethylene in specific ratios. This composite approach allows the mixture to achieve the desired cleaning performance while potentially reducing the overall environmental impact compared to using pure HFC compounds, as the trans-1,2-dichloroethylene component can be optimized to balance global warming potential with cleaning effectiveness.

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If azeotropic compositions with high HFC content are used, then environmental safety is improved, but solubility of oils and contaminants decreases

Engineering Contradiction:
Improveenvironmental safetyVSAvoidsolubility of oils and contaminants
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The patent optimizes the compositional parameters by establishing specific concentration ranges: 5-50% HFC-43-10mee and 50-95% trans-1,2-dichloroethylene. This parameter optimization ensures that the solvent mixture maintains adequate solubility for oils and contaminants while reducing HFC content to improve environmental safety, thus resolving the contradiction between environmental safety and cleaning capability.

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

These compositions offer enhanced solubility and environmental safety, effectively cleaning semiconductor surfaces without significant composition change during distillation, making them suitable for applications like defluxing and degreasing advanced packaging components.

Implementation Method 1

Azeotropic compositions comprising about 58-68 weight percent 1,1,1,2,3,4,4,5,5,5-decafluoropentane (HFC-43-10mee) and about 32-42 weight percent trans-1,2-dichloroethylene

Methodology Applied
Scientific EffectAzeotropic mixture:

Implementation Method 2

an amount effective in dissolving oils and contaminants of trans-1,2-dichloroethylene

Methodology Applied
Scientific EffectSolvation:

Data Source

PatentEP2099891B1Azeotrope-like mixtures comprising heptafluorocyclopentane
Publication Date: 2011.11.02 EI DU PONT DE NEMOURS & CO
  • EP2099891B1 patent drawingFigure 1

AI summary

Disclosed is an azeotrope-like composition comprising: from about 2% by weight to about 50% by weight of a hydrofluorocarbon selected from the group consisting of 1, 1,1, 2, 2, 3, 4, 5, 5, 5-decafluoropentane and 1, 1, 1, 3, 3-pentafluorobutane, from about 2% by weight to about 50% by weight 1, 1, 2, 2, 3, 3, 4-heptafluorocyclopentane, and an amount effective in dissolving oils and contaminants of trans-1,2-dichloroethylene. In another embodiment, are fluorocarbon solvent composition comprising from about 15 to about 99 weight percent 1, 1, 1, 2, 2, 3, 4, 5, 5, 5-decafluoropentane and from about 85 to about 1 percent by weight 1, 1, 2, 2, 3, 3, 4-heptafluorocyclopentane wherein the freezing point of the composition is less than 0 °C.