Laser and Electrochemical Studies of Metallizations in Electronic Devices

摘要

Irradiation of a Pb/Sn coating with excimer laser at 193nm with power density of0.5 to 0.7 J/p/sq cm resulted in producing surface melting. Pb-rich particles were found before and after laser treatment. Increasing the laser energy level as well as increasing the repetition rate resulted in decreasing the size of these particles. Corrosion studies by potentiodynamic technique show that the corrosion potential changed in the noble direction when the repetition rate and laser energy were increased. The laser-treated area did not corrode although the as-deposited adjacent area did. Corrosion occurred by general mode corrosion while lead was preferentially dissolved.(ttl)