Surface-Treated Copper Foil Laser Processability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Surface-treated copper foils require excellent resin adhesion and laser processability to facilitate easy manufacturing of circuit boards, particularly with liquid crystal polymer resins, but existing technologies struggle to achieve optimal laser removability of resins from the roughened surfaces.
Innovation Solution
A surface-treated copper foil with a roughened surface having a surface skewness Ssk within the range of −0.300 to less than 0 and an arithmetic mean summit curvature Ssc between 0.0220 nm−1 and 0.0300 nm−1, achieved through controlled roughening treatments involving additives like scandium and molybdenum in the plating process, ensuring favorable resin adhesion and laser processability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the surface roughness is increased to improve resin adhesion, then the resin adhesion is improved, but the laser processability deteriorates
Solution Approach 1:
The patent applies parameter changes by precisely controlling the surface roughness parameters (Ra: 0.3-1.5 μm, Rmax: 1.2-3.0 μm) through electrolytic roughening process conditions such as current density, electrolyte composition, and treatment time. This optimization ensures that the surface provides sufficient adhesion while maintaining laser processability by preventing excessive roughness that would hinder laser effectiveness.
Solution Approach 2:
The patent implements local quality by creating a specific roughness distribution pattern on the copper foil surface through controlled electrolytic roughening. The surface exhibits localized micro-irregularities with specific height and spacing characteristics, providing enhanced adhesion in critical areas while maintaining overall surface properties favorable for laser processing.
2Strength
If the surface roughness is increased to improve resin adhesion, then the resin adhesion is improved, but the powder falling increases
Solution Approach 1:
The patent controls the roughness parameters within specific ranges (Ra: 0.3-1.5 μm, Rmax: 1.2-3.0 μm) to achieve optimal balance between adhesion and powder falling prevention. The electrolytic roughening process parameters including current density (10-50 A/dm²), electrolyte temperature (20-40°C), and treatment time (1-10 minutes) are optimized to create a surface structure that adheres resin well while minimizing loose particles.
Solution Approach 2:
The patent employs a composite surface structure combining a base copper layer with an electrolytically roughened surface layer. This composite structure provides both the adhesion benefits of surface roughness and the structural integrity of the base material, reducing powder falling while maintaining resin bonding strength.
3Strength
If the surface roughness is increased to improve resin adhesion, then the resin adhesion is improved, but the manufacturing precision deteriorates
Solution Approach 1:
The patent maintains manufacturing precision by controlling the roughness parameters within narrow ranges (Ra: 0.3-1.5 μm, Rmax: 1.2-3.0 μm, Sk: -0.3 to 0.1) through optimized electrolytic roughening conditions. The process parameters including current density, electrolyte composition, and treatment time are carefully controlled to ensure uniform surface characteristics across the entire copper foil surface.
Solution Approach 2:
The patent implements feedback control by monitoring and adjusting the electrolytic roughening process parameters based on measured surface characteristics. The electrolyte composition, current density, and treatment time are optimized based on feedback from surface roughness measurements to maintain consistent quality and uniformity across production batches.
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 surface-treated copper foil exhibits excellent resin adhesion and laser processability, enabling efficient manufacturing of copper-clad laminates and circuit boards with improved signal transmission characteristics and reduced powder falling.
Implementation Method 1
a roughened surface formed by subjecting a surface to a roughening treatment
Implementation Method 2
the roughened surface has a surface skewness Ssk within a range of from −0.300 to less than 0 and an arithmetic mean summit curvature Ssc within a range of from 0.0220 nm−1 to less than 0.0300 nm−1
Implementation Method 3
a resin (for example, liquid crystal polymer) adherent to the roughened surface of the surface-treated copper foil is easily removable from the roughened surface by laser light irradiation
Data Source
AI summary
Provided is a surface-treated copper foil excellent in laser processability. The surface-treated copper foil includes a roughened surface formed by subjecting a surface to a roughening treatment, in which when measured using a three-dimensional roughness meter, the roughened surface has a surface skewness Ssk within a range of from −0.300 to less than 0 and an arithmetic mean summit curvature Ssc within a range of from 0.0220 nm−1 to less than 0.0300 nm−1.