Influence of CdZnTe/Au Contact on the Wire Bonding Property between the Down-Lead and Au Electrode

Abstract

According to the need to make high quality X-ray or γ-ray detectors made by high resistance CdZnTe, the wire bonding technology between the Au contact layer of CdZnTe wafer and the down-lead has been studied in this paper. The influence of welding parameters and surface treatment of CdZnTe wafer on the welding quality between Au contact layer and down-lead have been discussed in detail, such as chemical and mechanical polishing technology of CdZnTe wafer before welding, thickness of the contact layer of CdZnTe wafer, welding energy, welding pressure, welding time, and etc. The results showed that the successful jointing between Au contact layer of CdZnTe and down-lead can be achieved when applying the suitable welding parameters and pretreatment technology of CdZnTe wafer. The optimized welding parameters for CdZnTe wafer were as follows: welding power 2w, welding pressure 60×10-3 kg, welding time 20ms and the power for fire ball formation 1.5w.