Electrodeposited Copper Foil Blackening and Bonding Strength
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Solution Overview
Problem
The existing copper foils used in printed circuit boards often have incomplete blackening due to varying shapes and characteristics, leading to reduced reliability and bonding strength between conductive lines and boards.
Innovation Solution
An electrodeposited copper foil with a bulk copper content of at least 99% and a specific surface treatment layer, where the primary temperature (T105.0 wt %) is controlled between 550° C. to 750° C., and the surface treatment layer contains nickel, ensuring uniform blackening and improved bonding strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If blackening treatment is applied to copper conductive lines, then bonding strength between boards is improved, but incomplete blackening occurs due to varying shapes and characteristics of copper lines
Solution Approach 1:
The patent changes the chemical composition parameters of the copper foil by adding specific elements (Sn: 0.01-0.5 wt%, Zn: 0.01-0.5 wt%, Ni: 0.01-0.1 wt%) to modify the blackening characteristics. This enables uniform and complete blackening across copper lines with varying shapes and characteristics, resolving the reliability issue while maintaining improved bonding strength
Solution Approach 2:
The patent creates a surface treatment layer with distinct local composition characteristics through controlled oxidation. The surface layer contains higher concentrations of oxides and specific elements compared to the bulk material, providing localized properties that enhance both blackening completeness and bonding strength at the critical interface region
2Strength
If blackening treatment is applied to improve bonding strength, then polymer adhesive material can be embedded into pores, but thermal stability may be compromised
Solution Approach 1:
The patent creates a composite structure with a bulk copper foil containing specific alloying elements (Sn, Zn, Ni) and an oxidized surface treatment layer. This composite material configuration allows the bulk material to provide thermal stability while the surface layer provides bonding enhancement through pore formation and adhesive embedding
Solution Approach 2:
The patent carefully controls the oxidation parameters and alloy composition to achieve a surface treatment layer that provides adequate porosity for adhesive embedding while maintaining overall thermal stability. The specific element concentrations and oxidation conditions are optimized to balance bonding strength improvement with thermal stability preservation
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 controlled primary temperature and nickel surface treatment layer enhance the blackening of copper conductive lines, reducing the likelihood of incomplete blackening and improving the thermal stability and anti-oxidation properties of the copper foil.
Implementation Method 1
the primary temperature (T105.0 wt %) is controlled between 550° C. to 750° C.
Implementation Method 2
the surface treatment layer contains nickel
Data Source
AI summary
An electrodeposited copper foil includes a bulk copper foil. When a weight of the electrodeposited copper foil is increased to 105.0 wt % during a thermogravimetric analysis (TGA) performed on the electrodeposited copper foil at a heating rate of 5° C./min and an air flow rate of 95 mL/min, a heating temperature of the TGA is defined as T105.0 wt % and in a range of 550° C. to 750° C.