Improvement on Conductivity for Thick Film Aluminum Paste

Area of Science:

• Materials Science
• Electrical Engineering
• Nanotechnology

Background:

• Silver and copper pastes are common conductive fillings but face challenges with high cost and specific sintering requirements.
• Aluminum presents a viable alternative due to its lower cost, good conductivity, and air-sintering capability.

Purpose of the Study:

• To develop and optimize aluminum (Al) paste for high electrical conductivity in thick-film applications.
• To investigate the effects of particle size, glass frit content, and solid content on Al paste performance.

Main Methods:

• Utilized aluminum powder with mixed large and small particle sizes to leverage fracture mechanisms and gap-filling properties.
• Incorporated glass frit to promote particle bonding and inhibit oxidation during sintering.
• Investigated the influence of glass frit and solid content on the paste's conductivity.

Main Results:

• Achieved a low sheet resistance of 4.5 mΩ/□ for Al paste sintered at 850 °C for 10 minutes.
• Optimal formulation involved a 4:1 ratio of large to small Al particles, 10 wt% glass frit, and 80 wt% solid content.
• Demonstrated effective particle bonding and oxidation inhibition through optimized formulation.

Conclusions:

• Optimized aluminum paste provides a cost-effective and high-performance conductive filling solution.
• The developed paste overcomes limitations of silver and copper, enabling air-sintering.
• This research paves the way for wider adoption of aluminum in thick-film electronic applications.