Analysis of Fatigue Life Improvement for Damaged Copper Film by Multiple-times Laser Irradiation

Abstract

The mechanism of fatigue life improvement for copper film specimens with thickness of 25 um was investigated by multiple-times pulsed excimer laser surface irradiation processing under optimal parameters of laser irradiation at different loading levels . The results showed that fatigue life has an obvious improvement for the copper film specimens by multiple-times pulsed laser irradiation treatment. The degree of improvement in fatigue life for the damaged specimens by multiple-times pulsed laser irradiation treatment is more evident when the applied nominal stress was larger. The obtained total fatigue life for the copper film specimen reach up to 14 times that of no laser treatment under the stress level of 140MPa. The hardening induced by laser irradiation results in fatigue life improvement.