Foam Separator for Resist Stripping Process

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Solution Overview

Problem

Foam formation in process solutions used for removing resist layers from substrates in photovoltaic module production leads to process interruptions and environmental pollution, as defoamers are increasingly rejected due to cost and environmental concerns.

Innovation Solution

A method and device that separate process solution into two containers with a liquid-permeable wall, allowing foam to rise and be removed into a separate foam trough, while the foam-free solution is recycled, using angled pipes and spray nozzles to minimize foam formation and facilitate its removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-generated harmful factors

If defoamers are used as additives to reduce foam, then foam formation is reduced, but TOC load and COD value increase causing environmental pollution and exceeding discharge values

Engineering Contradiction:
Improvefoam formationVSAvoidTOC load and COD value in waste water
Core Design Contradiction:
Object-generated harmful factorsVSObject-affected harmful factors

Solution Approach 1:

The invention extracts and separates the foam from the process solution using a foam separator device. The foam separator includes a separation chamber where foam rises to the surface and is removed separately from the liquid process solution, which then can be recycled without contamination from defoaming chemicals

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces an intermediary device (foam separator with liquid-permeable wall) between the process solution and the environment. This intermediary allows the foam to be captured and removed while the clean process solution is returned to the system, avoiding the need for chemical defoamers that would pollute the waste water

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If process solution foams during pumping or spraying, then process interruptions and system malfunctions occur, but adding defoamers increases operational costs and environmental burden

Engineering Contradiction:
Improvecontinuous operation without process interruptionsVSAvoidoperational cost and environmental compliance
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The foam separator is integrated into the process solution circulation system to continuously separate and remove foam as the solution is pumped and sprayed. This continuous foam removal ensures uninterrupted operation without the need to stop the process for manual foam management or to deal with contaminated waste water

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system uses its own process solution to spray and remove foam from the surface of the collection tank, creating a self-cleaning mechanism. The sprayed liquid breaks up the foam and causes it to overflow into a separate foam collection area, eliminating the need for external defoaming chemicals

Inventive Principle:
Principle #25Self-service

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 reduces foam formation, allowing for continuous operation and environmentally friendly recycling of the process solution, minimizing waste and operational disruptions.

Implementation Method 1

a wall in between, which, however, is liquid-permeable due to recesses, holes, recesses or the like

Methodology Applied
Scientific EffectLiquid permeability: Permeation

Implementation Method 2

Foam can also form when the process solution is pumped around or sprayed onto the substrates

Methodology Applied
Scientific EffectFoam formation: Foam

Implementation Method 3

spraying, in particular spraying with the process solution itself

Methodology Applied
Scientific EffectSpray: Spray

Data Source

PatentEP2452356B1Method and device for treating substrates
Publication Date: 2013.06.05 GEBR SCHMID GMBH & CO
  • EP2452356B1 patent drawingFigure 1
  • EP2452356B1 patent drawingFigure 2
  • EP2452356B1 patent drawingFigure 3

AI summary

In a method and a device for treating substrates, resist layers are removed from the substrate by spraying on a process solution. The process solution is first sprayed onto the substrate in a primary stripping module and then in a secondary stripping module, with the solution collecting in containers beneath the modules. Containers are provided for each module. The process solution is collected in the primary stripping module in two containers, and to this end is first directly conducted into a second container, which is largely separated from the first container by a wall, which is pervious to fluid in a region that is considerably below the surface level of the process solution. The process solution is withdrawn without foam from the first container and recirculated into the process cycle for wetting the substrates.