Copper Surface Treatment for Corrosion Resistance
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Solution Overview
Problem
The electronics industry faces challenges with corrosion and wear resistance issues in copper substrates due to the porosity of thin precious metal coatings, which leads to reduced durability and effectiveness in harsh environments, particularly in connectors and printed circuit boards.
Innovation Solution
A surface treatment method using a composition comprising a phosphorus oxide compound, an organic compound with a nitrogen-containing functional group, and a solvent with low surface tension to form protective organic films on copper substrates, effectively blocking pores and enhancing corrosion and wear resistance without the need for thick precious metal layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If thin precious metal layers are used to reduce cost, then material cost decreases, but coating porosity increases leading to reduced corrosion and wear resistance
Solution Approach 1:
The copper substrate undergoes preliminary surface treatment with phosphoric acid or phosphorous acid before precious metal deposition. This creates a phosphorus-containing layer that acts as a diffusion barrier and nucleation site, preventing porosity formation in the subsequent thin precious metal coating and enabling effective corrosion and wear resistance at reduced thickness
Solution Approach 2:
The invention creates a composite surface structure consisting of a copper substrate with a phosphorus-containing intermediate layer and a thin precious metal overlayer. This composite structure combines the advantages of each layer: the phosphorus layer provides diffusion barrier properties and structural integrity, while the thin precious metal layer provides corrosion and wear resistance at reduced thickness
2Quantity of substance
If thin precious metal layers are used to reduce cost, then material cost decreases, but contact resistance increases over time
Solution Approach 1:
Surface treatment with phosphoric acid or phosphorous acid is performed before deposition to create a phosphorus-containing intermediate layer. This preliminary action ensures uniform nucleation and adhesion of the thin precious metal layer, preventing porosity and maintaining low contact resistance over time despite the reduced thickness
3Reliability
If thick precious metal layers are used to ensure durability, then corrosion and wear resistance improves, but material cost increases
Solution Approach 1:
The copper substrate is treated with phosphoric acid or phosphorous acid to create a phosphorus-containing layer that serves as a diffusion barrier and structural foundation. This preliminary treatment enables thin precious metal layers (0.01-0.5 μm) to achieve the same or better corrosion and wear resistance that would otherwise require much thicker coatings
Solution Approach 2:
The invention changes the chemical and physical parameters of the substrate surface through phosphoric acid or phosphorous acid treatment. This creates a phosphorus-containing intermediate layer with enhanced adhesion and diffusion barrier properties, allowing thin precious metal coatings to achieve optimal thickness and performance characteristics
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 method significantly improves the corrosion and wear resistance of copper substrates, allowing for the use of ultra-thin precious metal layers while maintaining effective contact resistance and extending the service life of electronic devices.
Implementation Method 1
A surface treatment method using a composition comprising a phosphorus oxide compound, an organic compound with a nitrogen-containing functional group, and a solvent with low surface tension to form protective organic films on copper substrates, effectively blocking pores
Implementation Method 2
A surface treatment method using a composition comprising a phosphorus oxide compound, an organic compound with a nitrogen-containing functional group, and a solvent with low surface tension to form protective organic films on copper substrates, effectively blocking pores
Implementation Method 3
a solvent with low surface tension to form protective organic films on copper substrates
Implementation Method 4
a solvent with low surface tension to form protective organic films on copper substrates
Data Source
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AI summary
A method and composition for enhancing corrosion resistance, wear resistance, and contact resistance of a device comprising a copper or copper alloy substrate and at least one metal-based layer on a surface of the substrate. The composition comprises a phosphorus oxide compound selected from the group consisting of a phosphonic acid, a phosphonate salt, a phosphonate ester, a phosphoric acid, a phosphate salt, a phosphate ester, and mixtures thereof; an organic compound comprising a nitrogen-containing functional group; and a solvent having a surface tension less than about 50 dynes/cm as measured at 25°C.