Patterning Copper using Ink Jet Printing of Self Assembled Monolayers

The ability to produce conductive copper tracks using ink-jet printing to allow the routine digital manufacture of patterned electrical interconnects is a long standing industry aim. In this study an approach to achieve this goal is investigated that uses an ink-jet printed self-assembled monolayer (SAM) coating as a molecular etch resist. To date, ink-jet printed SAMs on copper have not had sufficient quality to allow them to act in this way. However, recently an improved etching solution that enables similar quality microcontact printed SAM layers to act as resists on copper has been reported. Here this new etch solution is used to attempt to "develop" ink-jet printed SAM patterns on thin copper laminates into conductive tracks. The success of this approach and quality of resulting tracks is tested using optical microscopy, scanning electron microscopy and atomic force microscopy. This allows an assessment of the performance of this novel approach to interconnection manufacture to be made.