Laser Impulse Metal Bonding with Temporal Power Modulation

Inhalt:
In this paper we introduce a novel interconnection technology for the joining of thick metallic interconnectors to metallic coatings on sensitive substrates as employed in power electronics. The approach Laser Impulse Metal Bonding (LIMBO) enables users to join a 200 µm CuFe2P interconnector over a gap to a 35 µm thick copper coating by temporally modulating the power of the laser beam. By separating the process stage melting of the interconnector from the joining stage, we have been able to minimize the energy deposition in the metallic coating and achieve a weld penetration depth in the order of 20 µm.