Copper Etching Solution Using Maleic Acid and Copper Ions

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Solution Overview

Problem

Conventional etching solutions for copper-based wiring in display devices face issues such as high etching rates, corrosion, and safety hazards due to halide ions and hydrogen peroxide, and struggle with adhesion and diffusion problems, which affect the quality and reliability of copper-based wiring in display devices.

Innovation Solution

An etching solution containing a maleic acid ion source and a copper ion source, along with optional organic acid and pH adjustors, is used to control etching rates and prevent corrosion, ensuring stable and safe etching of copper-based materials without halide ions or hydrogen peroxide, suitable for multilayer structures like copper-molybdenum films.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If an etching solution containing halide ions is used for copper, then the etching rate is high, but the apparatus suffers corrosion

Engineering Contradiction:
Improveetching rateVSAvoidapparatus corrosion
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent removes halide ions (the harmful component) from the etching solution while maintaining copper etching capability through alternative chemistry involving maleic acid and copper ions, thereby eliminating apparatus corrosion while preserving productivity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent converts the harmful effect of halide ions by replacing them with a benign system using maleic acid and copper ions that achieves the same etching function without causing corrosion to the apparatus

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Productivity

If an etching solution containing hydrogen peroxide is used for copper, then the etching process is effective, but gas or heat is generated causing breakage of the apparatus

Engineering Contradiction:
Improveetching effectivenessVSAvoidgas generation and heat causing apparatus breakage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent extracts hydrogen peroxide from the etching solution to eliminate the dangerous decomposition reaction that generates gas and heat, while maintaining etching effectiveness through the maleic acid-copper ion system

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the hazardous hydrogen peroxide system with a safe maleic acid and copper ion system that provides the same etching function without generating dangerous gas or heat that could break the apparatus

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

3Productivity

If ammonia is used in the etching solution for copper, then the etching process works, but the reduction of ammonia concentration causes changes in etching rate and emitted ammonia worsens the working environment

Engineering Contradiction:
Improveetching process functionalityVSAvoidammonia emission and working environment deterioration
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent removes ammonia from the etching solution, replacing it with maleic acid and copper ions that provide etching functionality without producing harmful emissions that deteriorate the working environment

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the chemical parameters of the etching solution from an ammonia-based system to a maleic acid-copper ion system, fundamentally altering the chemistry to eliminate harmful emissions while maintaining etching effectiveness

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 solution provides a stable and controlled etching process for copper-based materials, preventing corrosion and residue formation, enabling high productivity and reliable etching of multilayer structures in display devices without safety hazards, and maintaining etching performance across varying concentrations and pH levels.

Implementation Method 1

an etching solution containing (A) a maleic acid ion source and (B) a copper ion source

Methodology Applied
Scientific EffectChemical etching: Chemical Bonding

Implementation Method 2

an organic acid ion source having two or more carboxyl groups and one or more hydroxyl groups per molecule

Methodology Applied
Scientific EffectChelation: Chemical Bonding

Data Source

PatentUS9644274B2Etching solution for copper or a compound comprised mainly of copper
Publication Date: 2017.05.09 MITSUBISHI GAS CHEM CO INC

AI summary

The present invention relates to an etching solution for copper or a compound comprised mainly of copper, wherein the etching solution contains (A) a maleic acid ion source and (B) a copper ion source, and an etching method using the etching solution.