Thin glass based packaging technologies for optoelectronic modules

The novel packaging approach glassPack is introduced as System-in-Package (SiP) technology. Wiring length can be reduced and integration density can be increased by stacking different assembled substrate layers and interconnecting them with one another resulting in 3D-SiP. Glass is an excellent material because of matched coefficient of thermal expansion (CTE) to silicon, high thermal load, dielectricity and high optical transparency over a wide wavelength range. Commercially available thin glass foils can be used as substrate material for electronic and optoelectronic modules. The goal of our ongoing development is making glass based packaging competitive with polymer based (e.g. chip-in-polymer) or silicon based packaging (e.g. silicon-through-via, stacked dies by wire bonding). Our work is focused on conductor trace and through-via realization as well as optical lightwave circuits integration using glass as substrate material. For through-vias in glass, holes were drilled in glass wafers by different laser technologies or etched using photosensitive glass and evaluated. Conductor traces and through-via interconnects were deposited on glass. Also, optical waveguide and fluidic channel integration in glass substrates were investigated. This paper presents the first demonstrator of our glass based packaging technology targeting sensor applications. Two silicon dies, a laser diode, two photodiodes and a fluidic-optical chip were mounted on a glass substrate and interconnected by 3D electrical wiring.