Self-Reducing Copper Precursor Inks and Photonic Additive Yield Conductive Patterns under Intense Pulsed Light

Area of Science:

• Materials Science
• Nanotechnology
• Electronics Engineering

Background:

• Printed electronics demand efficient methods for creating conductive interconnections on flexible substrates.
• Photonic curing using intense pulsed light (IPL) offers a rapid, roll-to-roll compatible approach for printed electronics.
• Copper formate inks are explored as precursors for conductive copper patterns due to their self-reduction properties.

Purpose of the Study:

• To investigate the use of intense pulsed light (IPL) for photonic curing of copper formate inks.
• To determine the critical IPL parameters for achieving conductive copper patterns.
• To evaluate the effect of carbon nanotubes (CNTs) on ink properties and IPL processing.

Main Methods:

• Copper formate inks with varying single-wall carbon nanotube (CNT) concentrations were formulated.
• Intense pulsed light (IPL) was applied with controlled pulse duration, intensity, and repetition rate.
• Electrical conductivity of printed patterns was measured.
• Optical absorptance of the inks was characterized.

Main Results:

• A specific set of IPL parameters is required to successfully form conductive copper patterns.
• Incorporating 0.5 wt% single-wall CNTs increased ink absorptance by approximately 50%.
• The addition of CNTs reduced the threshold IPL energy for conductivity by about 25%.

Conclusions:

• Photonic curing with IPL is a viable method for producing conductive copper patterns from copper formate inks.
• Single-wall CNTs significantly enhance ink light absorption, improving IPL processing efficiency.
• Optimizing IPL parameters and ink composition, particularly with CNTs, is crucial for advancing printed electronics fabrication.