Characterization of Thin Pixel Sensor Modules Interconnected with SLID   Technology Irradiated to a Fluence of 2$\cdot   10^{15}$\,n$_{\mathrm{eq}}$/cm$^2$
  A new module concept for future ATLAS pixel detector upgrades is presented, where thin n-in-p silicon sensors are connected to the front-end chip exploiting the novel Solid Liquid Interdiffusion technique (SLID) and the signals are read out via Inter Chip Vias (ICV) etched through the front-end. This should serve as a proof of principle for future four-side buttable pixel assemblies for the ATLAS upgrades, without the cantilever presently needed in the chip for the wire bonding.   The SLID interconnection, developed by the Fraunhofer EMFT, is a possible alternative to the standard bump-bonding. It is characterized by a very thin eutectic Cu-Sn alloy and allows for stacking of different layers of chips on top of the first one, without destroying the pre-existing bonds. This paves the way for vertical integration technologies.   Results of the characterization of the first pixel modules interconnected through SLID as well as of one sample irradiated to $2\cdot10^{15}$\,\neqcm{} are discussed.   Additionally, the etching of ICV into the front-end wafers was started. ICVs will be used to route the signals vertically through the front-end chip, to newly created pads on the backside. In the EMFT approach the chip wafer is thinned to (50--60)\,$\mu$m. 
P. Weigell (1), L. Andricek (1,2), M. Beimforde (1), A. Macchiolo (1),   H.-G. Moser (1,2), R. Nisius (1) and R.-H. Richter ...
physics.ins-det