Indirect Contact Probing Method for Characterizing Vertical Interconnections in Electronic Packaging

Abstract

This letter proposes a new indirect contact probing method to characterize vertical interconnections without contact damage. At the first step of the proposed technique, multiple oneport calibration measurements should be performed to characterize the contactor layer between the probe pads and the deviceunder-tests (DUTs). The characteristics of the actual vias as the DUTs are then extracted from indirect-contact measurements by de-embedding the contactor layer. In simulations and experiments at frequencies range from 2.5 to 18 GHz, we have verified via defects can be successfully identified from the indirect-contact measurements.

Numerical Verification of Dielectric Contactor as Auxiliary Loads for Measuring the Multi-Port Network Parameter of Vertical Interconnection Array

“…For the data of the dielectric film, we referred to the FARADFLEX R MC8M film [10], which has a thickness of 8 µm and a dielectric constant of 4.4. When compared to the dielectric contactor used in [6], [7], possibly weaker capacitive coupling due to the lower dielectric constant of the new material has been partially compensated by its smaller thickness. In real measurements, the smaller thickness can also enhance the forward coupling and reduce the cross coupling by confirming mechanically reliable contact with the DUT.…”

“…DC,pq (i ∈ P k ) is the two-port scattering (S-) parameter matrix of the dielectric contactor part for the i th interconnect, which can be obtained in a similar way to the single interconnect case by one-port indirect-and direct-contact probing measurements on three calibration vias presented in [6], under the assumption that mutual coupling is negligible [7].…”

“…For the issues regarding the multi-port vertical interconnection measurements, a dielectric contactor can be a solution. In the original indirect-contact probing method [6], [7], the dielectric contactor has been devised to protect a device under test (DUT) as well as to improve accuracy. In this paper, we propose to use the dielectric contatctor as auxiliary loads for un-probed ports as shown in Fig.…”