Tailoring and Assessing Copper Nanoparticle Seeded Electroless Copper Plating on Polymer Microspheres.

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• Electroless copper plating is essential for conductive coatings on polymer microspheres.
• Challenges include polymer inertness and lack of quality metrics.
• Copper-coated microspheres are key for anisotropic conductive adhesives.

Purpose of the Study:

• To develop a reliable electroless copper plating method for polymer microspheres.
• To introduce quantitative metrics for assessing coating quality.
• To establish correlations between coating properties and electrical performance.

Main Methods:

• Utilized copper nanoparticles as catalytic seeds for electroless plating.
• Employed a prereduction step with ammonia borane on styrene-divinylbenzene (PSDVB) microspheres.
• Optimized bath composition and processing conditions.

Main Results:

• Achieved dense copper coatings (0.047 μm) on PSDVB microspheres.
• Obtained high copper content (50.60 wt %) and low resistivity (6.04 × 10^-6 Ω·m).
• Introduced 'oxidation degree' and 'densification degree' for quality assessment.

Conclusions:

• Developed a tunable electroless copper plating process for microspheres.
• Established quantitative indicators for coating quality and electrical performance.
• Provided a framework for standardized fabrication of high-performance copper-coated microspheres.