Patent ID: 6544865
Filing Date: 2003-04-08
Classification: B23K

Abstract:
A method of electrically isolating regions of a metal film located over a delicate underlying structure by parting the metal film along a predetermined path, the method including the steps of:a) prior to forming the metal film, forming an inert or substantially inert layer over the underlying structure, at least in the region of a required isolation gap in the metal film; b) forming the metal film over the underlying structure and the inert layer; c) forming a series of holes through the metal film by ablating material from the metal film along the isolation path, to separate adjacent contacts, using a pulsed long wavelength laser having a wavelength which is only weakly absorbed by the underlying structure to minimize heating thereof, the laser pulse repetition rate, scan speed and power being selected to cause incomplete ablation of the material along the isolation path, while forming overlapping adjacent melt zones, the ablated material being sufficient to enable adjacent holes to join due to surface tension while the metal in the region of the holes is molten, while leaving the inert layer unbroken in the region of the isolation path.