Additive Manufacturing of Electrically Conductive Multi-Layered Nanocopper in an Air Environment

Area of Science:

• Materials Science
• Additive Manufacturing
• Nanotechnology

Background:

• Copper's high conductivity and lower cost make it ideal for aerospace, automotive, and electronics.
• Existing additive manufacturing methods for copper require high energy and oxygen-free environments.
• Developing cost-effective and accessible copper additive manufacturing is a significant industrial goal.

Purpose of the Study:

• To present a novel additive manufacturing route for copper microparts using nanoparticle (NP) ink.
• To demonstrate a low-power laser sintering process for copper NP consolidation in an air environment.
• To lay the groundwork for upscaling this technique for larger 3D copper part production.

Main Methods:

• Utilized novel nanoparticle (NP) copper ink.
• Employed inkjet printing and bar coating for ink deposition.
• Applied low-power (<10 W) laser sintering for particle consolidation in air.

Main Results:

• Successfully manufactured multi-layered copper microparts (~100 µm height) via 15-300 layer printing.
• Achieved consolidation without evidence of copper oxidation in an air environment.
• Sintered parts exhibited low density and porosity but attained an electrical resistivity of ~28 × 10^-8 Ω m.

Conclusions:

• The developed low-power laser sintering of copper nanoparticle ink offers a viable additive manufacturing pathway.
• This method bypasses the need for high-temperature, oxygen-free processing common in other copper AM techniques.
• The study provides foundational insights for scaling up additive manufacturing of copper parts using nanometal inks.