Joining of Thin Films on Flexible Substrates with Nanosecond Laser Pulses

The joining of thin film components has been increasingly required for a variety of applications. In this presentation a novel laser joining process for bonding thin films was demonstrated. A 500 nm thick silver film on polyimide foil is bonded to a 12.5 m thick silver foil by laser exposure with 248 nm, 20 ns excimer pulses. The joining of the foil to the film is achieved at a laser fluence of ~ 3.5 J/cm with approx. 150 pulses. The surface morphology after rupture of the bonded silver areas was studied by SEM. A maximum failure shear force of 0.4 N was measured.