Analysis and measurement of misalignment effect in inductive-coupling wireless inter-chip connection

Abstract

Inductive-coupling wireless connection is a promising interconnect technology for 3D stacked chips packaging. Misalignment between inductors of transmitter chip and receiver chip reduces the mutual inductance, leading to a signal transmit failure. A method to evaluate the signal attenuation caused by inductors misalignment is proposed based on the mutual inductance calculation. Misalignment tolerance under constant circuit parameters is given. Test chips are designed and fabricated in 180 nm CMOS process to verify the method. Measurements of the test chip show that the proposed method match well with testing results.