Cu salt ink formulation for printed electronics using photonic sintering.

Area of Science:

• Materials Science
• Nanotechnology
• Chemistry

Background:

• Photonic sintering offers a promising route for fabricating conductive materials.
• Controlling ink properties is crucial for optimizing photonic sintering processes.

Purpose of the Study:

• To develop copper salt precursor inks for photonic sintering using high-intensity pulsed light (HIPL).
• To investigate the relationship between ink properties, particularly light absorption and carbon content, and sintering behavior.
• To assess the electrical conductivity of sintered copper wires and their environmental implications.

Main Methods:

• Formulation of copper salt precursor inks (copper formate, acetate, oleate).
• Characterization of ink light absorption properties influenced by ligand coordination and carbon chain length.
• Photonic sintering of inks using high-intensity pulsed light (HIPL).
• Measurement of electrical resistivity of sintered copper wires.

Main Results:

• Ink light absorption is sensitive to ligand structure and carbon chain length, affecting sintering energy requirements.
• Integral absorbance coefficients strongly correlate with photonic sintering behavior.
• Sintered copper wires from copper formate ink achieved low resistivity (5.6 × 10⁻⁵ Ω cm).
• Increased carbon chain length led to higher resistivity due to residual carbon impacting morphology and conductivity.

Conclusions:

• Ink absorbance properties are the most critical factor for effective photonic sintering.
• High light absorptivity and low carbon content in precursor inks are essential for efficient sintering.
• Optimized inks can reduce energy consumption and carbon emissions, leading to a lower environmental load.