Fine-pitch copper wiring formed in a platingless process using ultra-fine inkjet and oxygen pump

Two technologies have been developed and successfully applied for forming fine-pitch copper wiring on demand. They are an ultra-fine inkjet called super-inkjet and cool powder sintering (CPS) utilizing the oxygen pump technology. Super-inkjet has realized 3 micrometer line widths and spaces drawn in copper nanoparticle inks. CPS has turned such lines into bulk metal without a void with low resistivity of 2.6 microhm cm at only 180 degrees Celsius. This is a new route to manufacturing copper interconnect on plastic substrates without the need of making masks.