Assembly of 3D probe array for wireless implantable neuroprobe microsystem

Abstract

Assembly methods with specially designed Si interposer and Si platform are described for low profile 3D neural probe array assembly in this paper. In this method, in order to assemble the probe array with low profile and connect the probe with ASIC chips, an interposer is designed to connect the electrical pads on the sidewall of the probe and the electrical pads on the surface of the Application-specific integrated circuit (ASIC) chip. To hold the probe array and ASIC chip, a Si platform is designed with through Si slot for insertion of probe and cavity for holding the interposer. The electrical interconnections between the probe and the ASIC chip are formed by conventional flip chip bonding method. Therefore the throughput for the 3D probe array can be improved. Another advantage of the developed assembly method is that the backbone of the probe can be embedded inside the cavity of the Si platform, as a results, the profile of the probe array on top of the Si platform is controlled lower than 1mm easily, which make sure it does not touch skull after implant into the brain.