Packaging design and test of cryogenic readout electronics for the Euclid Near Infrared Spectrophotometer

We describe the design of the cryogenic packaging and testing of the Sensor Chip Electronics delivered for the Near-Infrared Spectro-Photometer NISP instrument for the ESA Euclid mission. The Euclid instrument and telescope payload is in integration and test with the spacecraft bus summer 2022. It will observe ∼ 1/3 of the total sky using a telescope with 1.2m SiC primary mirror, passively cooled to ∼ 125K, and containing Visible Imager (VIS) and NISP focal plane instruments, from an orbit at the Earth-Sun L2 Lagrange point. At the heart of the NISP instrument is a 4 × 4 mosaic focal plane of Teledyne H2RG infrared detector arrays held at 100K linked using a cryogenic flex cable CFC to the SCE at as low as 130K. The SCE uses Teledynes SIDECAR Application Specific Integrated Circuit (ASIC) to provide timing, biases, communications, and data conversion for operation of the H2RG SCA and interfaces NISP warm electronics. The SIDECAR ASIC is mounted onto a Silicon Fanout (SiFO) and invar table support structure and then wirebonded to a printed wiring board assembly (PWB) with passive components and 91 pin nano-connectors. The PWA is housed within an enclosure which serves as the mechanical and thermal interface to the NISP Support Structure. The qualification and flight SCE were assembled and subjected to environmental testing at the Jet Propulsion Laboratory and then calibrated and tested with the flight lot SCA and CFC at Goddard Space Flight Centers Detector Characterization Lab. The results of the qualification and reliability tests as well as the measured characteristics of the flight SCE will be summarized.