Corona Ionizer Gas Separation for Clean Static Neutralization

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional corona discharge ionizers generate contaminants along with ions, leading to unwanted byproducts such as ozone, nitrogen oxides, and solid deposits, which can contaminate surfaces during static charge neutralization in clean environments like semiconductor manufacturing, and existing methods to mitigate this often introduce foreign materials or exacerbate emitter erosion.

Innovation Solution

The method involves superimposing ionizing and non-ionizing electrical fields to separate corona-generated ions from contaminant byproducts, utilizing a pressure differential to keep contaminants within the plasma region while allowing ions to enter a non-ionized gas stream, and employing a low-pressure emitter shell to shield the ionizing electrode and prevent byproducts from entering the main gas stream.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If corona discharge is used to generate gas ions for charge neutralization, then ionization efficiency is improved, but contaminant byproducts (ozone, nitrogen oxides, solid deposits) are generated

Engineering Contradiction:
Improveionization efficiencyVSAvoidcontaminant byproducts
Core Design Contradiction:
Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

The invention divides the gas flow into two separate streams: a first gas stream passes through the corona discharge region to generate ions, while a second clean gas stream is used to transport these ions to the treatment chamber. This segmentation prevents contaminants generated in the corona region from reaching the treatment area, resolving the contradiction between ionization efficiency and contaminant generation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention extracts the ion generation function from the ion transport function by using two separate gas streams. The first gas stream carries ions away from the corona discharge region, while the second clean gas stream transports them to the treatment chamber. This extraction eliminates contaminant byproducts from the treatment path while maintaining effective ion delivery.

Inventive Principle:
Principle #2Taking out (Extraction)

2Duration of action of stationary object

If strongly corrosive-resistant materials (such as tungsten) are used for emitters to reduce erosion, then emitter durability is improved, but foreign materials are introduced into the process

Engineering Contradiction:
Improveemitter durabilityVSAvoidforeign materials
Core Design Contradiction:
Duration of action of stationary objectVSObject-generated harmful factors

Solution Approach 1:

The invention extracts the emitter from the direct path of the clean gas stream by using a dual-stream configuration. The first gas stream passes through the corona discharge region containing the emitter, while the second clean gas stream transports ions without contacting the emitter. This allows the use of silicon emitters (compatible with semiconductor processes) without introducing foreign materials, while maintaining emitter durability through reduced erosion.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The first gas stream acts as an intermediary that carries ions from the corona discharge region to the mixing point, while the second clean gas stream serves as the transport medium to the treatment chamber. This intermediary arrangement allows the emitter to be made from process-compatible materials without contaminating the treatment area.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If a single gas stream is used for both ion generation and transport, then device complexity is reduced, but contaminant byproducts reach the treatment surface

Engineering Contradiction:
Improvegas stream configurationVSAvoidcontaminant byproducts
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The invention segments the gas flow path into two distinct streams with different functions: one for ion generation and transport out of the corona region, and another for clean ion delivery to the treatment chamber. This segmentation effectively prevents contaminant byproducts from reaching the treatment surface while maintaining manageable device complexity through a straightforward dual-stream architecture.

Inventive Principle:
Principle #1Segmentation

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

This approach effectively separates ions from contaminants, producing a clean ionized gas stream that reduces contamination and maintains the integrity of the neutralization process without introducing foreign materials, enhancing the efficiency and cleanliness of static charge neutralization.

Implementation Method 1

at least one ionizing electrode for producing a plasma region comprising ions and contaminant byproducts

Methodology Applied
Scientific EffectCorona discharge: Corona Discharge

Implementation Method 2

maintaining a lower pressure in the plasma region to force at least a substantial portion of the corona byproducts into the plasma region

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 3

superimposing ionizing and non-ionizing electrical fields to separate corona-generated ions from contaminant byproducts

Methodology Applied
Scientific EffectElectrical field induction: Electric Field

Data Source

PatentEP3399343B1Clean corona gas ionization for static charge neutralization
Publication Date: 2023.04.05 ILLINOIS TOOL WORKS INC
  • EP3399343B1 patent drawingFigure 1a
  • EP3399343B1 patent drawingFigure 1b
  • EP3399343B1 patent drawingFigure 1c

AI summary

Clean corona gas ionization by separating contaminant byproducts from corona generated ions includes establishing a non-ionized gas stream having a pressure and flowing in a downstream direction, establishing a plasma region of ions and contaminant byproducts in which the pressure is sufficiently lower than the pressure of the non-ionized gas stream to prevent at least a substantial portion of the byproducts from migrating into the non-ionized gas stream, and applying an electric field to the plasma region sufficient to induce at least a substantial portion of the ions to migrate into the non-ionized gas stream.