Air-curable Conductive Copper Paste

Printed electronics has received increasing attention in recent years as a promising technology for the next generation of IoT. Compared with photolithography, it not only enables circuit fabrication on flexible substrates, but also cost reduction through the elimination of some processes such as exposure and etching.

Conductive paste is a key material for this technology. Currently silver is the most commonly used filler for conductive pastes due to its high conductivity and stability. However, silver has some concerns such as price volatility and ionic migration. Therefore, copper is expected to an acceptable alternative material because of its significant advantage in cost and higher resistance to migration while providing the same level of conductivity as silver.

NAMICS is developing conductive copper pastes which have high conductivity with 200 deg C curing. Even as development is continuing, we can provide evaluation samples of the three types of copper pastes shown below.

Cross-sectional image of the cured copper paste
Cross-sectional image of the cured copper paste

・Air-curable Cu Paste
 @XCH9207 High-Conductivity
 AXCH9280 Good-Printing Performance
・N2-curable Cu Paste
 BXCH9215 Excellent Conductivity and Printing Performance

Filler Diameter[μm] Printing Performance Conductivity(Air-curing) Conductivity(N2-curing)
XCH9207 10 Fair Excellent Good
XCH9280 5 Good Good Good
XCH9215 1 Excellent Poor Excellent