Optimized wire-bond transitions for microwave applications up to 67 GHz using the low loss LTCC material DuPont 9k7

This paper presents two different wire-bond transitions, a wideband from DC up to 67 GHz and a narrowband, working at the free-licensed ISM band around 60 GHz, which are suitable for multilayer System-in-Package (SiP) and Multi-Chip-Module (MCM) applications. An aluminium oxide ceramic (Al₂O₃) RF test chip is assembled in a small cavity on the low temperature cofired ceramics (LTCC) material DuPont 9k7. An automatic ball-wedge bonder is used for thermosonic gold wire bonding. A return loss better than -10 dB from DC up to 54 GHz for the wideband and better than -10 dB for the narrowband transition, having a 6 GHz bandwidth in the 60 GHz ISM band, as well as an insertion loss of <;1 dB at 60 GHz were achieved for both transitions during measurements.