IWORID2022

Abstracts

Title

• Speaker: Peter Svihra
• Status: Accepted
• Abstract: Hybrid pixel detectors require a reliable and cost-effective interconnect technology adapted to the pitch and die sizes of the respective applications. Moreover, during the ASIC and sensor R&D phase and for small-scale applications, such interconnect technologies need to be suitable for the hybridisation of single dies available from Multi-Project-Wafer submissions. Within the CERN EP R&D programme and the AIDAinnova collaboration, innovative hybridisation concepts targeting vertex-detector applications at future colliders are under development. Recent results of two novel interconnect methods for pixel pitches of 25-55 microns are presented by this contribution – an industrial fine-pitch SnAg solder bump-bonding process adapted to single-die processing, as well as a newly developed in-house single-die interconnection process based on Anisotropic Conductive Film (ACF). The fine-pitch bump-bonding approach is qualified with hybrid assemblies from a recent bonding campaign at IZM, where individual CLICpix2 ASICs with 25 microns pitch were bump-bonded to active-edge silicon sensors with thicknesses ranging from 50 microns to 130 microns. The device characterisation was conducted in the laboratory as well as during a beam test campaign at SPS, demonstrating an interconnect yield of above 99.9%. On the other hand, the ACF interconnect technology replaces solder bumps by conductive micro-particles embedded in an epoxy film. The connection of sensor and ASIC is achieved by placing the film in between and applying pressure and heat using a flip-chip component placer. The required topology of the pixel pads is achieved with an in-house Electroless Nickel Gold (ENIG) plating process. This newly developed ACF hybridisation process is first qualified with Timepix3 ASICs and sensors with 55 μm pitch. The technology can be also used for module integration, replacing wire bonding or large-pitch solder bumping techniques. This contribution introduces the ACF and ENIG processes and presents first test results on Timepix3 hybrid assemblies. This project has received funding from the European Union’s Horizon 2020 Research and Innovation programme under GA no 101004761

• Slides