Cu Paste for Molded Interconnect Devices

Cu particles with an average particle size of 130 nm were found to be suitable for low-temperature metallization. Cu wirings with line/space (L/S) = 150 μm/150 μm and L/S = 150 μm/100 μm were formed by screen printing and aerosol jet printing, respectively. The shear strength of the Cu wiring that was covered by the SnBi solder including epoxy resin and liquid-crystalline polymer substrate was 7 MPa; the shear strength was maintained even after a high-temperature storage test (125 °C for 200 h). The developed Cu paste could be used as a via connection material, and employed for the fabrication of Cu wiring on two-dimensional and three-dimensional substrates.