Laser-induced gold deposition for thin-film circuit repair (Invited Paper)

Laser chemical vapor deposition (LCVD) of gold has been used to repair 'open' defect on high-end multi-chip packaging modules. The ability to repair metallurgical features of less than 25 μm width was readily accomplished and electrical resistances are comparable to resistances of unrepaired nets of identical geometry. The reliability of LCVD repairs was monitored after thermal processing, T&H and electrical stressing. The ability to repair 'open' defects in the thin-film redistribution (TFR) layer of the module has facilitated testing of designs early in the development process.