Electrolytic Sulfuric Acid Handling for Stable Substrate Oxidation

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Solution Overview

Problem

The oxidizing power of electrolytic sulfuric acid decreases over time when used for substrate treatment due to autolysis, leading to inefficiencies in substrate treatment processes.

Innovation Solution

A substrate treatment device and method that includes a substrate treatment unit, a supply tank, a temperature increasing unit, a generation unit, and a collection unit, which utilize electrolytic sulfuric acid and imparted water to maintain and regenerate the oxidizing power of the treatment liquid through temperature adjustment and electrolysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If electrolytic sulfuric acid is used as treatment liquid for substrate treatment, then waste liquid amount is reduced, but oxidizing power decreases over time due to autolysis

Engineering Contradiction:
Improvewaste liquid amountVSAvoidoxidizing power
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

The patent applies parameter changes by controlling the temperature of electrolytic sulfuric acid. Specifically, the acid is heated to 60-90°C during substrate treatment to enhance oxidizing power, then rapidly cooled to 0-10°C during storage to suppress autolysis and maintain reliability over time. This dynamic parameter adjustment resolves the contradiction between maintaining oxidizing power and reducing waste.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements periodic action through alternating heating and cooling cycles of the electrolytic sulfuric acid. The system periodically heats the acid before treatment operations to activate oxidizing power, then periodically cools it for storage to prevent degradation. This rhythmic parameter change allows the system to achieve both high oxidizing power during use and low waste through suppressed autolysis during storage.

Inventive Principle:
Principle #19Periodic action

2Reliability

If temperature of electrolytic sulfuric acid is increased for substrate treatment, then oxidizing power is enhanced, but autolysis accelerates leading to faster degradation

Engineering Contradiction:
Improveoxidizing powerVSAvoidservice life of treatment liquid
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent applies preliminary action by rapidly cooling the electrolytic sulfuric acid to 0-10°C immediately after treatment and before storage. This preliminary cooling action suppresses autolysis and extends the service life of the treatment liquid, allowing it to maintain oxidizing power for longer periods during subsequent storage and reuse cycles.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements beforehand cushioning by maintaining the electrolytic sulfuric acid at low temperature (0-10°C) during storage periods between treatments. This temperature cushioning protects the treatment liquid from rapid degradation, ensuring it remains effective for multiple treatment cycles and thereby extending its operational duration.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Duration of action of moving object

If electrolytic sulfuric acid is stored at low temperature to suppress autolysis, then service life is extended, but oxidizing power is insufficient for effective treatment

Engineering Contradiction:
Improveservice life of treatment liquidVSAvoidoxidizing power
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The patent applies dynamics by making the temperature of electrolytic sulfuric acid variable rather than fixed. The system dynamically adjusts temperature based on operational requirements: cooling to 0-10°C for storage to extend service life, then heating to 60-90°C during treatment to ensure sufficient oxidizing power. This dynamic temperature control resolves the contradiction between service life and oxidizing power.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by transitioning the temperature parameter of electrolytic sulfuric acid between two distinct states: a low-temperature state (0-10°C) for storage that extends service life, and a high-temperature state (60-90°C) for treatment that provides sufficient oxidizing power. This parameter switching allows the system to achieve both extended durability and effective treatment performance.

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

The device and method effectively maintain the oxidizing power of electrolytic sulfuric acid, ensuring consistent and efficient substrate treatment by continuously regenerating the treatment liquid.

Implementation Method 1

a generation unit that generates the treatment liquid by electrolysis and supplies the generated treatment liquid to the supply tank

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Implementation Method 2

a temperature increasing unit that increases a temperature of the treatment liquid by mixing imparted water with the treatment liquid supplied from the supply tank in the substrate treatment unit

Methodology Applied
Scientific EffectExothermic reaction: Exothermic Reaction

Data Source

PatentEP4645371A1Substrate processing apparatus and substrate processing method
Publication Date: 2025.11.05 SCREEN HOLDINGS CO LTD
  • EP4645371A1 patent drawingFigure 1
  • EP4645371A1 patent drawingFigure 2~3
  • EP4645371A1 patent drawingFigure 4

AI summary

Substrate treatment is performed while suppressing decrease in oxidizing power of electrolytic sulfuric acid. A substrate treatment device includes a substrate treatment unit that treats a substrate using a treatment liquid containing electrolytic sulfuric acid, a supply tank that stores the treatment liquid to be supplied to the substrate treatment unit, a temperature increasing unit that increases a temperature of the treatment liquid by mixing imparted water with the treatment liquid supplied from the supply tank in the substrate treatment unit, a generation unit that generates the treatment liquid by electrolysis and supplies the generated treatment liquid to the supply tank, and a collection unit that collects a treated liquid which is the treatment liquid used in the substrate treatment unit and supplies the treated liquid to the generation unit.