A Printing Strategy for Embedding Conductor Paths into FFF Printed Parts

Area of Science:

• Additive Manufacturing
• Materials Science
• Electrical Engineering

Background:

• Fused filament fabrication (FFF) enables integrated conductor paths via embedding isotropic conductive adhesive (ICA).
• Direct deposition of molten plastic onto uncured ICA leads to inhomogeneous displacement and unreliable conductor paths.

Purpose of the Study:

• To develop and validate a 3D printing strategy for achieving homogeneous cross-sections of ICA conductor paths in FFF.
• To optimize printing parameters for consistent ICA path formation.

Main Methods:

• A novel strategy involving printing a groove, embedding ICA, and sealing with a wide extruded plastic strand was developed.
• Parameter studies were conducted to determine optimal groove dimensions (layer height, depth) and sealing strand diameter.
• Specimens using polylactic acid (PLA) with embedded ICA paths were fabricated and evaluated.

Main Results:

• The optimized parameters yielded a homogeneous ICA conductor path cross-section.
• The conductor path width was 660 µm ± 22 µm (3.3% RSD) and cross-sectional area was 0.108 mm² ± 0.008 mm² (7.2% RSD).
• This represents the first successful demonstration of a printing strategy for homogeneous conductive traces in FFF.

Conclusions:

• The developed 3D printing strategy effectively creates homogeneous ICA conductor paths in FFF.
• This approach overcomes previous limitations of inhomogeneous ICA displacement.
• The findings pave the way for reliable 3D printed electronics with integrated conductive pathways.