Design of Broadband Interconnects for Millimeter-Wave Wirebond Package Applications

by Yi-Chieh Lin

Institution: NSYSU
Department: Electrical Engineering
Degree: PhD
Year: 2015
Keywords: millimeter-wave package; defected ground structure (DGS); QFN package; discontinuity compensation; Ribbon wire-bonding
Record ID: 1388082
Full text PDF: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0411115-162632


Nowadays many wireless communication applications have pushed device operation frequency into millimeter-wave range. For this reason, the selection of a package is critical. The dissertation aims to investigate a low-cost wideband QFN package for realizing chip-package-board co-simulation up to millimeter-wave frequencies. The dissertation addresses two approaches for this purpose. Firstly, the QFN package uses two ground paths in parallel with the help of backside via of GaAs chip and wire-bonding connection. The performance comparison is made between round bond-wires and ribbon bond-wires for the package with a plastic molding. To obtain the accuracy performance of wire-bonding transition, a de-embedding process is established. Secondly, a defected ground structure (DGS) is studied for application to the QFN package. The technique of using high-impedance DGS with an inductive characteristic was presented for the first time to compensate for the packaging transition that has a capacitive nature. Moreover, the chip-package co-design considers the effects of the necessary plastic molding for chip protection. It is worth to mention that the DGS was implemented externally to the QFN package, so there is no need to alter the design of the QFN package. The proposed technique can thus be widely applied to many other QFN packages or wirebond packages with similar lead configurations. Finally, the DGS opening helps to improve impedance matching and reduces the insertion loss, thus further extending the range of operating frequencies to E band. Through the careful design, the simulation results agree with measurement results quite well in this dissertation.