High-Frequency Testing of Vertical Interconnection Array Using Indirect Contact Probing Method With an Improved Calibration

As a solution to the need for efficient characterization of the vertical interconnection array, this paper presents an indirect contact probing method, adopting a dielectric contactor. The dielectric contactor protects vertical interconnections, resolves the issue of probe misalignments, and increases the coupling between probe tips and devices under test (DUTs). The characterization procedure is composed of the extraction of the dielectric contactor characteristic, the indirect contact measurement of DUTs, and de-embedding to obtain the DUT characteristics. To realize the multiport measurement, we propose an approximate method to formulate the scattering matrix of the dielectric contactor. For the design of calibration vias, the coaxial transmission line model with lumped elements is used, enhancing the available bandwidth of measurement. To verify the proposed method, a two-port network of two vias is characterized by numerical simulations up to 20 GHz. With the presented measurement setup, three cases of two vias are characterized up to 12 GHz. For the testing approach, DUTs containing open and short defects are fully tested by observing impedance curves up to 20 GHz.