  Application Specific Integrated Circuits (ASICs) are commonly used to
efficiently process the signals from sensors and detectors in space. Wire
bonding is a space qualified technique of making interconnections between ASICs
and their substrate packaging board for power, control and readout of the
ASICs. Wire bonding is nearly ubiquitous in modern space programs, but their
exposed wires can be prone to damage during assembly and subject to electric
interference during operations. Additional space around the ASICs needed for
wire bonding also impedes efficient packaging of large arrays of detectors.
Here we introduce the Through Silicon Vias (TSV) technology that replaces wire
bonds and eliminates their shortcomings. We have successfully demonstrated the
feasibility of implementing TSVs to existing ASIC wafers (a.k.a. a via-last
process) developed for processing the X-ray signals from the X-ray imaging
CdZnTe detectors on the Nuclear Spectroscopic Telescope Array (NuSTAR) Small
Explorer mission that was launched in 2012. While TSVs are common in the
semiconductor industry, this is the first (to our knowledge) successful
application for Astrophysics imaging instrumentation. We expect that the TSV
technology will simplify the detector assembly, and thus will enable
significant cost and schedule savings in assembly of large area CdZnTe
detectors.
