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 $(L/S) = 150~\mu m/ 150~\mu m$ and $L/S= 150~\mu m/100~\mu m$ 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.