Fabrication, Integration, Packaging

Fabrication, packaging and integration are main research topics at IMST, which encompass packaging of biosystems, optical systems and 3D Heterogeneous Micro Nano Systems.One major research area is combining microsystems with conventional IC circuits, where the main challenges are to develop a bonding methodology, both for vacuum encapsulation of microdevices, as well as interconnects between the various parts so that subsequent thermal cycles do not compromise either device. The group has investigated SLID (Solid Liquid Inter-Diffusion) bonding using Cu/Sn and Au/Sn (high melting point metal/low melting point metal). This approach allows for chip stacking without compromising the earlier fabricated bond frame or stacked interconnects.

The group is also working on the integration of microsystems with fabrics, bonding of compliant interconnects, wafer-level integration of lens arrays for bolometers, direct Au-Au die attach either by thermocompression or ultrasonic bonding, as well as further enhancements for the SLID bonding technology.

(Nils Høivik)