Formation of Precise Electrically-Conductive Circuit with Metal Colloid Ink

Abstract

Precise electrically-conductive circuit were formed using silver colloid pattern on a plastic film by a PIJ (Plating on Ink Jet pattern) method or a PFS (Plating on Filled and Squeezed pattern) method. In the PIJ, method a copper plating layer was formed on a silver colloid pattern that was formed in advance with an ink jet printer. In the PFS method, a copper plating layer was formed on the silver colloid pattern which was obtained by filling the laser engraved groove with silver colloid particles. The layer thickness of the copper plating layer in this case was in a range of 5 to 10μm. The finest line width obtained was about 30 μm in the PIJ pattern and 5 μm in the PFS pattern. An electrical resistivity of smaller than 10−5Ωcm was attained.The adhesive strength of the copper layer onto the substrate surface was improved by adjusting the porosity of the film surface for ink jet printing or the depth of the groove on the laser engraved film surface.Applications of these techniques to electronic components such as electric circuit boards, capacitors, inductors, electrodes, RFID antennas and electromagnetic wave shield films were discussed.