Interconnection for Power Electronics Using Laser Ablation

Due to the increase in working temperature of power electronic components, the conventional component design is slowly facing out and is being replaced with new design which introduces new challenges to the manufacturing process. Flat silver films with customised geometry are required to realise the new component design but such films are hard to produce with conventional manufacturing methods. This paper details the feasibility study of using laser ablation technique in producing customised patterns on thin silver film for lamination during power electronic manufacturing process. The laser used in the study is a 30 W nanosecond laser from IPG with a wavelength of 1064 nm. The ablation profiles with different laser parameters are presented and the influence of the beam energy distribution and pulse duration on the ablation quality is discussed. It was found that shorter pulse duration produces better surface finish with minimal re-melting and smaller cut width. The optimum laser parameter was determined to be 30 W with a pulse duration of 4 ns, frequency of 750 kHz and a scanning speed of 1000 mm/s to ablate a silver film of ~70 μm thick on a PET substrate. The optimised laser ablation parameters were employed to demonstrate the production of a customised silver film.