Excimer laser patterning of thick and thin films for high density packaging

Excimer laser patterning of thick and thin films for high density packaging
Proc. SPIE, Vol. 3184, 176 (1997); DOI:10.1117/12.280571

Abstract

Excimer laser projection methods have ben developed to directly create high resolution electrical circuits in both thin nd thick-film metallic layers in order to form robust, compact multi-chip module interconnection devices, miniature sensor elements, miniature flexible printed circuits, antennas etc at high sped and low cost. Patterning over small or large areas is possible at high speed using simple step and repeat or more complex synchronous mask and workpiece scanning methods. Ablation rates depend strongly upon the thickness of the metal layer varying from complete metal removal with 1 laser shot for thin films to multiple 10s of shots for films to a few J/cm2 for screen printed polymer thick films or thick sputtered films. Multiple layer interconnect circuits and complex advanced sensor devices have been successfully fabricated using these excimer laser metal film patterning methods together with laser via drilling and patterning of dielectric layers using a laser tool with appropriate level to level alignment and mask changing and scanning facilities.