Copper Etchant Composition for Display Substrate Manufacturing
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Solution Overview
Problem
Conventional etchants for copper or copper alloy metal layers in display substrate manufacturing face issues such as explosive reactions, low storage stability, and the need for composition adjustments based on film thickness, leading to inefficient pattern formation and increased manufacturing costs.
Innovation Solution
An etchant composition of 50% to 70% phosphoric acid, 1% to 5% nitric acid, 10% to 20% acetic acid, 0.1% to 2% azole-based corrosion inhibition agent, and the remainder water, which includes a fluorine-containing compound, is used to etch copper or copper alloy metal layers, allowing for fine pattern formation and stable operation across varying thicknesses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If peroxide etchant is used to etch copper film, then etching speed is improved, but safety deteriorates due to explosion risk from chemical reaction
Solution Approach 1:
The patent replaces the harmful peroxide etchant with a non-peroxide etchant composition containing phosphoric acid, nitric acid, and acetic acid. This conversion eliminates the explosion risk while maintaining effective etching capability through the synergistic action of the alternative chemical components.
Solution Approach 2:
The patent changes the chemical composition parameters of the etchant by substituting peroxide with a specific formulation of phosphoric acid (5-20%), nitric acid (5-30%), and acetic acid (70-85%). This parameter change achieves the same etching function without the harmful explosive properties of peroxide.
2Object-affected harmful factors
If conventional non-peroxide etchant is used, then safety is improved, but manufacturing precision deteriorates due to small cumulative etched amount and low storage stability
Solution Approach 1:
The patent creates a composite etchant formulation combining phosphoric acid, nitric acid, and acetic acid in specific proportions. This composite composition achieves both safety (non-peroxide) and manufacturing precision (cumulative etching capability and storage stability) through the synergistic interaction of multiple chemical components.
Solution Approach 2:
The patent optimizes the concentration parameters of each acid component to achieve the desired balance between safety and precision. The specific ranges (phosphoric acid 5-20%, nitric acid 5-30%, acetic acid 70-85%) are determined to provide sufficient etching power while maintaining storage stability and pattern quality.
3Reliability
If conventional etchant composition is used, then etching capability is maintained, but adaptability deteriorates as composition must be changed based on film thickness
Solution Approach 1:
The patent develops a universal etchant composition that can handle different copper film thicknesses without requiring formulation changes. The multi-functional formulation combines phosphoric acid (for controlled etching), nitric acid (for oxidation), and acetic acid (for buffering), enabling consistent performance across varying film thicknesses.
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 etchant effectively reduces skew length, maintains pattern quality, and increases the cumulative treatable amount, resulting in lower manufacturing costs and improved etching performance.
Implementation Method 1
an etchant includes about 50% by weight to about 70% by weight of phosphoric acid, about 1% by weight to about 5% by weight of nitric acid, about 10% by weight to about 20% by weight of acetic acid
Implementation Method 2
about 1% by weight to about 5% by weight of nitric acid
Implementation Method 3
about 0.1% by weight to about 2% by weight of a corrosion inhibition agent including an azole-based compound
Implementation Method 4
a protective layer including benzotriazole combined with copper or a copper alloy is formed on an etched surface of the metal pattern
Data Source
AI summary
An etchant includes about 50% by weight to about 70% by weight of phosphoric acid, about 1% by weight to about 5% by weight of nitric acid, about 10% by weight to about 20% by weight of acetic acid, about 0.1% by weight to about 2% by weight of a corrosion inhibition agent including an azole-based compound and a remainder of water.