Uniform Matte Electrodeposited Copper Foil via Cationic Polymer Additive
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Solution Overview
Problem
Existing electrodeposited copper foils with high current density electrodeposition suffer from poor uniformity of the matte surface, leading to issues such as poor etching during PCB manufacturing and potential short circuits in automotive applications.
Innovation Solution
The development of an electrodeposited copper foil with a uniform matte surface, achieved by maintaining an average thickness of 30 μm to 400 μm and using a specific electrolytic solution composition, including copper sulfate, sulfuric acid, chloride ions, and a nitrogen-containing cationic polymer, which allows for electrodeposition at a current density of 30 A/dm² to 100 A/dm² without compromising surface uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high current density (higher than 30 A/dm2) is used for electrodeposition to increase production rate, then productivity is improved, but the uniformity of the matte surface deteriorates due to abnormal protrusions forming on the deposited surface
Solution Approach 1:
The invention changes the chemical parameters of the electrolytic solution by introducing a nitrogen-containing cationic polymer with specific molecular weight (100-10,000 g/mol) and controlled ionic strength (0.1-1.0 M). This parameter modification allows the system to maintain high current density electrodeposition (30-100 A/dm2) while suppressing abnormal protrusion formation, thus achieving both high productivity and high surface uniformity simultaneously
Solution Approach 2:
The invention creates a composite electrolytic system combining traditional copper sulfate and sulfuric acid with a nitrogen-containing cationic polymer. This composite formulation synergistically enhances copper deposition uniformity at high current densities, preventing the formation of abnormal protrusions while maintaining industrial production rates
2Length of moving object
If the electrodeposition duration is lengthened to manufacture thick copper foil (greater than 30 μm), then the thickness requirement is met, but abnormal protrusions form on the matte surface due to insufficient time control
Solution Approach 1:
The invention implements process feedback through real-time monitoring of deposition characteristics and uses the nitrogen-containing cationic polymer to dynamically adjust the deposition behavior. This feedback mechanism allows extended electrodeposition durations to produce thick foils (30-400 μm) while maintaining surface uniformity by continuously suppressing protrusion growth through the polymer's leveling effect
3Manufacturing precision
If conventional additives are added in large amounts to suppress abnormal protrusions, then surface uniformity is improved, but the service life of the electrolytic solution decreases and waste removal requirements increase
Solution Approach 1:
The invention optimizes the concentration parameter of the nitrogen-containing cationic polymer within a specific range (0.1-100 ppm) to achieve effective protrusion suppression. This optimized parameter setting provides sufficient surface uniformity while minimizing additive consumption, thereby extending electrolyte service life and reducing waste management requirements compared to conventional high-concentration additive systems
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 resulting copper foil exhibits a uniform matte surface with a low number of protrusions, enhancing the reliability and safety of automotive PCBs by reducing the risk of poor etching and short circuits, while maintaining an industrial production rate.
Implementation Method 1
electrodeposited copper foil with a uniform matte surface... applying an electric current at a current density to an anode plate and a rotating cathode electrode drum that are spaced apart from each other in the electrolytic solution; electrodepositing a copper foil on the rotating cathode drum
Implementation Method 2
The electrolytic solution comprises: about 120 g/L to about 450 g/L of copper sulfate... electrodepositing a copper foil on the rotating cathode drum
Data Source
AI summary
The present invention discloses an electrodeposited copper foil with a uniform matte surface. The electrodeposited copper foil of the present invention has an average thickness (TAve) of about 30 μm to about 400 μm; and the matte surface of the present electrodeposited copper foil has a uniformity factor (UF) of 5.5 μm or less.Also disclosed are methods for manufacturing the present electrodeposited copper foils and articles made therefrom.