A new approach on MEMS sensor batch testing using an analogue parallel test methodology for massive reduction of test time

With a tremendous shipment increase of MEMS microphones during the last few years, enhanced testing methods have become a key issue for industrial batch manufacturing, focusing on the mechanical sensitivity of the sound transducing diaphragm. Instead of semi-parallel techniques, in which test channels and measurement equipment are duplicated (with a multiplication of invest) for the purpose of further reduction of test time, this paper shows a novel approach for a massive parallel test of MEMS sensors. With several DUTs connected in parallel, the resulting measurements hence reveal several overlain device characteristics, each accounting for the sensitivity of one single DUT. For the specific correlation of those characteristics to each DUT, a reconstruction method known from tomography imaging techniques is adapted. The measurement results on wafer level shown in this paper exhibit the basic suitability of a single test of several DUTs in parallel and prove the concept of this novel method.